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  • 2005-2009
  • 2000-2004  (29)
  • 1985-1989  (2,996)
  • Engineering General  (2,473)
  • Genetics  (552)
  • 1
    Electronic Resource
    Electronic Resource
    A study of Italian families with cluster headache (2000)
    Springer
    The journal of headache and pain 1 (2000), S. S165 
    Details
    ISSN: 1129-2377
    Keywords: Key words Cluster headache ; Familial occurrence ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A Danish genetic study showed increased risk of cluster headache (CH) among relatives of CH patients. We studied the families of 191 CH patients (118 males, 73 females; mean age 45.9 years) attending the Milan Headache Center. Information on 3589 relatives was collected by direct interview of the probands (n = 118) or by mailed questionnaire (n = 73). The diagnostic criteria of the IHS were used. A positive family history was found in 19% (37 of 191) of the families. A total of 32 first-degree (32 of 1036, 3.1%) and 15 second-degree (15 of 2553, 0.6%) relatives were affected. The relative risk of CH was 26.89 (95% CI, 17.57–36.21) in the first-degree relatives and 4.35 (95% CI, 2.13–5.21) in second-degree relatives. This study shows increased familial risk of cluster headache in an Italian population and confirms that cluster headache is, in some families, and inherited disorder.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101940070012
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  • 2
    Electronic Resource
    Electronic Resource
    Molecular genetics and migraine (2000)
    Springer
    The journal of headache and pain 1 (2000), S. S135 
    Details
    ISSN: 1129-2377
    Keywords: Key words Migraine ; Headache ; Genetics ; Serotonin ; Dopamine ; Mitochondria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Migraine carries a significant hereditary determination. Familial hemiplegic migraine (FHM) has been recently linked to mutations in the CACNA1A gene on chromosome 19. CACNA1A codes for a subunit of a neural calcium channel. Other linkage loci on chromosome 1q21-23 and 1q31 have been reported. Several linkage and association studies have been performed to determine the role of the CACNA1A gene, and of other candidate genes implicated in the metabolism of serotonin and dopamine, in the more common types of migraine. Co-morbidity of migraine with vascular events has been analysed versus genetic prothrombotic factors and mitochondrial DNA, and genes involved in the inflammatory cascade have been explored. Though no definite conclusions have emerged from these studies as yet, molecular genetics of migraine can be expected to unravel the complex aetiologies of these fascinating diseases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101940070007
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  • 3
    Electronic Resource
    Electronic Resource
    Molecular variation within the dopamine receptor DRD2 gene in migraine (2000)
    Springer
    The journal of headache and pain 1 (2000), S. S147 
    Details
    ISSN: 1129-2377
    Keywords: Key words Dopamine ; Migraine ; Genetics ; DRD2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Molecular genetics offers a novel approach to the understanding and management of migraine since the disorder is known to have a strong genetic component. In recent studies, polymorphisms in the genes for dopamine receptors have been evaluated. Both positive and negative association studies have been reported. In particular, these data suggest that activation of the DRD2 receptor plays a modifying role in the pathophysiology of migraine. As a result, existing data provide a molecular rationale for the documented efficacy of dopamine D2 receptor antagonists in the treatment of migraine. Therefore, at the present time, molecular genetic data provide support for the hypothesis that susceptibility to migraine may be modified, in part, by variations in dopamine DRD2 receptor function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101940070009
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  • 4
    Electronic Resource
    Electronic Resource
    Genetic factors in migraine and chronic tension-type headache (2000)
    Springer
    The journal of headache and pain 1 (2000), S. S157 
    Details
    ISSN: 1129-2377
    Keywords: Key words Migraine ; Chronic tension type headache ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Pathophysiological studies have dominated migraine research for several years. However, these studies are difficult to interpret because it is difficult to decide whether the observed phenomena are primary or secondary to the migraine attack. For that reason it is important that future migraine research focus on studies that concern migrain etiology. Migraine is a paroxysmal disorder. It is most likely and ion-channel disorder like familial hemiplegic migraine. The present paper focuses on genetic factors in migraine and chronic tension-type headache.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101940070011
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  • 5
    Electronic Resource
    Electronic Resource
    Central nervous system hemangioblastomas, endolymphatic sac tumors, and von Hippel-Lindau disease (2000)
    Springer
    Neurosurgical review 23 (2000), S. 1-22 
    Details
    ISSN: 1437-2320
    Keywords: Key words Von Hippel-Lindau disease ; Hemangioblastoma ; Endolymphatic sac tumor ; Angiogenesis ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Von Hippel-Lindau disease (VHL) is a hereditary cancer syndrome caused by germline mutations of the VHL tumor suppressor gene. Major progress has been made in the last decade in both clinical and fundamental aspects of VHL. The VHL gene product, pVHL, has major and multiple functions: pVHL regulates not only first angiogenesis but also extracellular matrix formation and the cell cycle. A molecular diagnosis of VHL is now available, leading to a transformation in clinical management of patients and their families. Diagnosis of VHL has to be suspected in patients with a VHL-related tumor without familial history and especially in case of hemangioblastoma or endolymphatic sac tumors. Such patients should be systematically investigated for clinical and molecular evidence of VHL disease. Treatment of symptomatic hemangioblastomas remains mainly neurosurgical, often in emergency, but stereotactic radiosurgery is emerging as an alternative therapeutic procedure. In the future, antiangiogenic drugs could represent a potential medical treatment of CNS hemangioblastomas in view of their highly vascular structure. Lastly, visceral manifestations of VHL disease are also of critical importance and require early detection for effective treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101430050024
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  • 6
    Electronic Resource
    Electronic Resource
    Dopamine genes and migraine (2000)
    Springer
    The journal of headache and pain 1 (2000), S. S153 
    Details
    ISSN: 1129-2377
    Keywords: Key words Migraine ; Genetics ; Dopamine ; Hypersensitivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Migraine is a common chronic disorder with an etiology still mostly unknown. Several neurotransmitters such as dopamine and serotonin are considered to be involved in the pathogenesis of the disease and the study of their systems is crucial in the understanding of migraine. Dopaminergic receptors are variously represented in human CNS and periphery. The hypothesis that a hypersensitivity of the dopaminergic system may have a role in migraine is based on clinical and genetic data. Genetic data are represented by association studies using dopaminergic genes as candidate genes which show that the D2 receptor gene appears to be involved in the pathogenesis of migraine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101940070010
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  • 7
    Electronic Resource
    Electronic Resource
    HLA and migraine genes (2000)
    Springer
    The journal of headache and pain 1 (2000), S. S141 
    Details
    ISSN: 1129-2377
    Keywords: Key words Migraine ; Genetics ; Human leukocyte antigens ; Heredity ; Susceptibility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Human leukocyte Antigens (HLA) are encoded by genes located on chromosome 6p21. Genes important in migraine are being recognized in two basic ways: association studies and linkage analysis. One of the strongest associations is with the HLA region. Actually, genome scan studies suggest that multiple genes are involved in both migraine without aura (MWoA) and migraine with aura (MWA). However, both MWoA and MWA are disorders in which multiple factors, including environmental and genetic factors, confer disease susceptibility. Linkage analysis is identifying new candidate genes that will help to explain the etiology of migraine. In this review previous studies regarding genetic susceptibility to migraine are analyzed, particularly those related to the HLA region. I discuss evidence that HLA shared-hyplotypes in MWoA-affected pairs in different than that expected, that HLA-DR2 antigen provides additional basis for the proposed genetic heterogeneity between MWoA and MWA, and lastly that TNFB gene studies seem to play an important role in the susceptibility to MWoA. In the past years, major advances hae been made in understanding the genetic foundation of MWoA and MWA. Our reported genome-scan studies support the concept that MWoA/MWA are coinherited with a particular HLA region. However, the examination of candidate genes (Ca2+ channel, vascular, CNS, etc.) in a large migraine population seems to be the correct direction in which we have to move. More MWoA/MWa gene studies are needed to test this developing hypothesis and to further establish the complete genetic scenario of migraine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101940070008
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  • 8
    Electronic Resource
    Electronic Resource
    Progress in the clinical and molecular genetics of familial parkinsonism (2000)
    Springer
    Neurogenetics 2 (2000), S. 207-218 
    Details
    ISSN: 1364-6753
    Keywords: Key words Parkinson's disease ; Familial Parkinson's disease ; Synuclein ; Parkin ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: ABSTRACT¶Parkinson's disease (PD) is a neurodegenerative disease with clinical features resulting from deficiency of dopamine in the nigrostriatal system. Most PD cases are sporadic and the primary cause of the disease is still unknown. Recently, familial PD and parkinsonism have received much attention because these forms of the disease might provide clues to the genetic risk factors involved in the pathogenesis of idiopathic PD. To date, two causative genes, α-synuclein and the parkin gene, have been identified. α-Synuclein is involved in the pathogenesis of an autosomal dominant form of PD and constitutes a major component of the Lewy body, which is a pathological hallmark of idiopathic PD. In addition, mutations in the parkin gene have been identified as the cause of autosomal recessive juvenile parkinsonism (AR-JP). AR-JP manifests itself as a highly selective degeneration of the substantia nigra and the locus coeruleus, but without Lewy body formation. In addition to these two genes, four chromosomal loci have been linked to other forms of familial PD. Furthermore, there are a number of other pedigrees of familial PD in which linkage to known genetic loci has been excluded. Molecular cloning of these disease genes and elucidation of the function of their gene products will greatly contribute to our understanding of the pathogenesis of idiopathic PD.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100489900083
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  • 9
    Electronic Resource
    Electronic Resource
    Association of TNFA gene polymorphism at position –308 with susceptibility to irritant contact dermatitis (2000)
    Springer
    Immunogenetics 51 (2000), S. 201-205 
    Details
    ISSN: 1432-1211
    Keywords: Key words Skin ; Genetics ; TNFA ; ¶Inflammation ; PCR-RFLP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Mechanisms underlying susceptibility to skin irritants are not clearly understood. Cytokines play a key role in inflammation, and functional polymorphisms in cytokine genes may affect responses to irritants. We investigated the relationship between polymorphism in the tumor necrosis factor (TNF) α-chain gene and responses to irritants. Volunteers (n=221) tested with sodium dodecyl sulfate (SDS) and benzalkonium chloride (BKC) were divided into responders and nonresponders and high and low irritant-threshold groups. DNA was assayed for the TNF-308 polymorphism by a polymerase chain reaction-restriction fragment length polymorphism method. There was a significant increase in the A allele (P=0.030) and AA genotype (P=0.023) in both the SDS low irritant-threshold group and in SDS responders (A allele P=0.022, AA genotype P=0.048). In the BKC low irritant-threshold group, we found a significant increase in the A allele (P=0.002) and AA genotype (P=0.016). Individuals with a low threshold to both irritants demonstrated a significant increase (P=0.002) in the A allele. This is the first description of a nonatopic genetic marker for irritant susceptibility in normal individuals. Genotyping for theTNF-308 polymorphism may thus contribute to screening of individuals deemed at risk of developing irritant contact dermatitis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050032
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  • 10
    Electronic Resource
    Electronic Resource
    Susceptibility to critical illness: reserve, response and therapy (2000)
    Springer
    Intensive care medicine 26 (2000), S. S057 
    Details
    ISSN: 1432-1238
    Keywords: Key words Critical illness ; Intensive care ; Severity of illness ; Scoring systems ; Genetics ; Susceptibility ; Education
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Risk of critical illness is determined both by genetic and environmental influences, particularly those relating to infectious and cardiovascular diseases. Physiologically-based scoring systems cannot measure prior risk because they do not quantify physiological reserve independently of the acute illness. Genetic profiling could be useful for risk assessment. Early detection of critical illness involves identifying physiological ’triggers' for referral; this requires the education of nursing and medical staff in their significance. Analysis of the relationship between risk factors and interventions may need complex modelling techniques. Therapeutic strategies depend on the nature of the underlying problem: the most useful are likely to be those which enhance tissue oxygen delivery and resistance to infection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001340051120
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  • 11
    Electronic Resource
    Electronic Resource
    Oligohydramnion, renal failure and no pulmonary hypoplasia in glomerulocystic kidney disease (2000)
    Springer
    Pediatric nephrology 14 (2000), S. 319-321 
    Details
    ISSN: 1432-198X
    Keywords: Key words Glomerulocystic kidney disease ; Oligohydramnion ; Renal failure-neonate ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Two newborns with glomerulocystic kidney disease manifesting as late onset oligohydramnion and neonatal anuria, yet without severe respiratory distress, are presented. They had a similar perinatal course and associated clinical manifestations. No associated congenital or inherited malformation syndrome could be defined. Both infants’ parents were first degree cousins and belonged to the same small Bedouin tribe, and neither they nor the infants’ siblings had polycystic kidneys or renal insufficiency, pointing to either a possible genetic etiology or a common external toxic exposure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004670050767
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  • 12
    Electronic Resource
    Electronic Resource
    Bridging the gap between molecular genetics and metabolic medicine: access to genetic information (2000)
    Springer
    European journal of pediatrics 159 (2000), S. S183 
    Details
    ISSN: 1432-1076
    Keywords: Key words Database ; Genetics ; Information services ; Internet ; Mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Thanks to the World Wide Web, most results of research in genetics are made available in public databases. At the present time there are resources on genetic diseases, genes and their location, mutations of already cloned genes and on laboratories performing the mutation analysis. The main resources on phenotypes are On-line Mendelian Inheritance in Man (OMIM), Pedbase, GeneClinics, London Dysmorphology Database (LDDB) and Orphanet. The main resources on human genes are, in addition to OMIM, the Genome Database, Genatlas and Genecard. There are also two major sequence databases. All of them can be queried using the OMIM number of the disease. Central databases of mutations, as well as locus specific databases have been created. Their list is maintained at the Human Genome Organisation mutation database initiative website. Several initiative have been taken to integrate all these data and help the clinician to find out quickly what he/she needs. The website of the National Center for Biotechnology Information is the best example of such an effort with sections on diseases, a genome guide, and locus links. Several databases of genetic testing resources have been established. GeneTests is an on-line genetics resource that contains a directory of North American laboratories providing testing for heritable disorders. Orphanet is a similar database on French services which is in the process of becoming a European database. Conclusion Even if clinicians do not have as many services at their disposal as the molecular geneticists, various useful databases already exist and should no longer be ignored in practice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00014399
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  • 13
    Electronic Resource
    Electronic Resource
    Genetic determinants of hyperhomocysteinaemia: the roles of cystathionine β-synthase and 5,10-methylenetetrahydrofolate reductase (2000)
    Springer
    European journal of pediatrics 159 (2000), S. S208 
    Details
    ISSN: 1432-1076
    Keywords: Key words Cardiovascular disease ; Cystathionine β-synthase ; Genetics ; Methylenetetrahydrofolate reductase ; Mild hyperhomocysteinaemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Over the last decade mild hyperhomocysteinaemia has widely been recognised as a new risk factor for arteriosclerosis and thrombosis. Main regulating enzymes of homocysteine (Hcy) metabolism are cystathionine β-synthase (CBS), methionine synthase and methylenetetrahydrofolate reductase (MTHFR). Early studies on patients with vascular disease described elevated Hcy concentrations after methionine loading and decreased CBS activity, resembling heterozygotes for CBS deficiency. Therefore, heterozygosity for CBS deficiency was proposed as the main cause of mild hyperhomocysteinaemia. However, more recent enzymatic and molecular genetic studies have demonstrated that heterozygosity for CBS deficiency is not or only a very minor cause of mild hyperhomocysteinaemia in vascular disease. We discovered two common genetic causes of mild hyperhomocysteinaemia, the 677C 〉 T and the 1298A 〉 C mutations in the coding region of MTHFR. The 677C 〉 T mutation causes reduced enzyme activity with thermolabile protein properties, elevated Hcy and low-normal or decreased plasma folate levels. The 1298A 〉 C mutation relates also to decreased enzyme activity, but not to thermolabile protein, and Hcy and folate levels are not influenced. However, compound heterozygosity for these two mutations, i.e. individuals with the 677CT/1298AC genotype, have elevated Hcy and decreased plasma folate levels. Gene-enviroment interactions between 677C 〉 T and folate is demonstrated in individuals with the 677TT genotype. Those with low-normal folate have elevated Hcy, whereas those with high-normal folate have normal Hcy concentrations. The elevated Hcy levels due to these mutations can be normalised by administration of folate, but whether folate reduces the risk of cardiovascular disease remains to be established. Conclusion Heterozygosity for cystathionine β-synthase deficiency is a minor cause of hyperhomocysteinaemia. The current data on mutations in the methylenetetrahydrofolate reductase gene do not tell us whether elevated plasma homocysteine plays a causal role in vascular disease. Low cellular vitamin status may be a possible cause and homocysteine may just be a marker for this situation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00014405
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  • 14
    Electronic Resource
    Electronic Resource
    Aetiology of overweight and obesity in children and adolescents (2000)
    Springer
    European journal of pediatrics 159 (2000), S. S35 
    Details
    ISSN: 1432-1076
    Keywords: Key words Obesity ; Genetics ; Child ; Nutrient balance ; Energy balance ; Environment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The epidemic diffusion of obesity in industrialised countries has promoted research on the aetiopathogenesis of this disorder. The purpose of this review is to focus mainly on the contribution that European research has made to this field. Available evidence suggests that obesity results from multiple interactions between genes and environment. Parents obesity is the most important risk factor for childhood obesity. Twin, adoption, and family studies indicated that inheritance is able to account for 25% to 40% of inter-individual difference in adiposity. Single gene defects leading to obesity have been discovered in animals and, in some cases, confirmed in humans as congenital leptin deficiency or congenital leptin receptor deficiency. However, in most cases, genes involved in weight gain do not directly cause obesity but they increase the susceptibility to fat gain in subjects exposed to a specific environment. Both genetic and environmental factors promote a positive energy balance which cause obesity. The relative inefficiency of self-adapting energy intake to energy requirements is responsible for fat gain in predisposed individuals. The role of the environment in the development of obesity is suggested by the rapid increase of the prevalence of obesity accompanying the rapid changes in the lifestyle of the population in the second half of this century. Early experiences with food, feeding practices and family food choices affect children's nutritional habits. In particular, the parents are responsible for food availability and accessibility in the home and they affect food preferences of their children. Diet composition, in particular fat intake, influences the development of obesity. The high energy density and palatability of fatty foods as well as their less satiating properties promotes food consumption. TV viewing, an inactivity and food intake promoter, was identified as a relevant risk factor for obesity in children. Sedentarity, i.e. a low physical activity level, is accompanied by a low fat oxidation rate in muscle and a low fat oxidation rate is a risk factor of fat gain or fat re-gain after weight loss. Conclusion Further research is needed to identify new risk factors of childhood obesity, both in the genetic and environmental areas, which may help to develop more effective strategies for the prevention and treatment of obesity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00014361
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  • 15
    Electronic Resource
    Electronic Resource
    Genotyping of presenilin-1 polymorphism in amyotrophic lateral sclerosis (2000)
    Springer
    Journal of neurology 247 (2000), S. 940-942 
    Details
    ISSN: 1432-1459
    Keywords: Key words Amyotrophic lateral sclerosis ; Genetics ; Presenilin-1 intron 8 polymorphism ; Apoptosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The mechanisms underlying motor neuron degeneration in amyotrophic lateral sclerosis are not fully understood. Recent studies suggest that apoptosis is involved in the abnormal neural death that occurs in this devastating disease. Presenilin-1, a transmembrane protein, seems to be implicated in apoptosis. To determine whether presenilin-1 intron 8 polymorphism has an influence in the course of amyotrophic lateral sclerosis, we examined this polymorphism genotypes in a large group of patients (n=72) with amyotrophic lateral sclerosis and in a random sample of 213 healthy individuals. The results showed a significant difference in genotype (P 〈 0.04) and allele (P 〈 0.03) distribution between patients and controls. These results suggest a possible intervention of presenilin-1 in the pathogenesis of amyotrophic lateral sclerosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004150070050
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  • 16
    Electronic Resource
    Electronic Resource
    Vascular risk factors in dementia (2000)
    Springer
    Journal of neurology 247 (2000), S. 81-87 
    Details
    ISSN: 1432-1459
    Keywords: Key words Dementia ; Vascular ¶dementia ; Alzheimer’s disease ; Risk factors, stroke ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This review describes differing profiles of vascular risk factors in different types of dementia. Although vascular risk factors are related to various types of strokes, their independent effect on the occurrence of poststroke dementia appears to be small. Various risk factors have been identified for microangiopathy-related cerebral abnormalities, such as white matter changes and lacunae, which are the core lesions for the development of a vascular dementia syndrome without stroke symptoms. Most consistently, arterial hypertension and diabetes mellitus have been found to be associated with such brain abnormalities. Diastolic blood pressure seems to be of particular importance as recent investigations demonstrate that this factor is related to the course of multiple lacunar strokes and the progression of white matter disease. Epidemiological studies report that various vascular risk factors including arterial hypertension, diabetes mellitus, and atrial fibrillation may also be associated with Alzheimer’s disease. There is also evidence of a direct relationship between Alzheimer’s disease and general atherosclerosis. Further investigations are needed to determine whether these associations are due to the weakness of diagnostic criteria, or whether vascular risk factors indeed modulate the clinical expression of primary degenerative dementia. Common susceptibility genes leading to shared risk factors may be one of the reasons for a higher coincidence of Alzheimer’s disease and vascular dementia than can be expected by chance. A modulatory effect of vascular risk factors in the development of primary degenerative dementia may extend treatment options.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004150050021
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  • 17
    Electronic Resource
    Electronic Resource
    The monoamine oxidase B gene GT repeat polymorphism and Parkinson’s disease in a Chinese population (2000)
    Springer
    Journal of neurology 247 (2000), S. 52-55 
    Details
    ISSN: 1432-1459
    Keywords: Key words Parkinson’s disease ; Monoamine oxidase B ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Monoamine oxidase B (MAOB) metabolises dopamine and activates neurotoxins known to induce parkinsonism in humans and primates. Therefore the MAOB gene (MAOB; Xp15.21–4) is a candidate gene for Parkinson’s disease (PD). Longer length dinucleotide repeat sequences in a highly polymorphic GT repeat region of intron 2 of this gene showed an association with PD in an Australian cohort. We repeated this allele-association study in a population of 176 Chinese PD patients ¶(90 men, 86 women) and 203 age-matched controls (99 men, 104 women). Genomic DNA was extracted from venous blood and the polymerase chain reaction was used to amplify the appropriate regions of the MAOB gene. The length of each (GT) repeat sequence was determined by 5% polyacrylamide denaturing gel electrophoresis. There was no significant difference in allele frequencies of the (GT) repeat allelic variation between patients and controls (χ2 = 2.48; df = 5, P 〈 0.75). Therefore the longer length GT repeat alleles are not associated with PD in this Chinese population. Possible reasons for the discrepancy between Chinese and Australian populations include a different interaction between this genetic factor and environmental factors in the two populations and the possibility that the long length GT repeat alleles may represent a marker mutation, genetically linked to another susceptibility allele in whites but not in Chinese. Methodological differences in the ascertainment of cases and controls in this cohort could also explain the observed differences. Further study is required to determine whether the longer length GT repeat alleles are true susceptibility alleles in PD.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004150050010
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  • 18
    Electronic Resource
    Electronic Resource
    Progressive supranuclear palsy: earlier age of onset in patients with the τ protein A0/A0 genotype (2000)
    Springer
    Journal of neurology 247 (2000), S. 206-208 
    Details
    ISSN: 1432-1459
    Keywords: Key words Progressive ¶supranuclear palsy ; Genetics ; Clinical characteristics ; Parkinsonism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Genetic studies have detected an association between the presence of the τ gene A0 allele and patients with progressive supranuclear palsy (PSP). This study examined whether patients with this polymorphism exhibit distinct demographic or clinical characteristics. We studied 26 patients who fulfilled clinical criteria for the diagnosis of PSP, 20 who had the A0/A0 genotype and 6 who had other genotypes. A questionnaire on demographic data, past medical history, familial history, and initial symptoms was completed as part of the consultation. A complete neurological examination was performed and PSP symptoms were quantified following Golbe’s PSP disability scale. We found a significant difference in the age at onset of PSP symptoms, which was 65.9 ± 5.3 years in the A0/A0 group and 71.2 ± 5.6 in the non-A0/A0 group (P = 0.016). There were no significant differences in the years from disease onset between the two groups. Symptom severity did not differ significantly in patients with the different A0/A0 genotypes. The detection of significantly lower age at onset with the A0/A0 alleles is consistent with the known association of this genotype as a risk factor for PSP. No significant differences were detected in symptom severity between the two groups of patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004150050564
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  • 19
    Electronic Resource
    Electronic Resource
    Incidence of CSF abnormalities in siblings of multiple sclerosis patients and unrelated controls (2000)
    Springer
    Journal of neurology 247 (2000), S. 616-622 
    Details
    ISSN: 1432-1459
    Keywords: Key words Multiple sclerosis ; Siblings ; Genetics ; Oligoclonal bands ; Measles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We found that 19% (9/47) of healthy siblings of patients with clinically definite multiple sclerosis had an intrathecal immunological reaction with two or more 2 CSF-enriched oligoclonal bands (OCBs), in contrast to (4%) (2/50) unrelated healthy controls. Furthermore, in this group of nine healthy sibs the measles CSF IgG antibody titers were higher than that of the other sibs and that of controls. There were also differences in the serum titers for measles IgG antibody, which were higher in the group of all healthy sibs than in healthy volunteers, and (as with CSF titers) higher in the subgroup of healthy sibs with two or more 2 CSF-enriched OCBs than the other sibs. Thus a significant proportion of healthy siblings to MS patients have a partially hyperimmune condition similar to that occurring in MS, which in 19% manifested itself as an OCB reaction, in 9% as increased CSF measles IgG antibody titers, and in 21% as increased serum measles IgG antibody titers, these phenomena tending to occur in the same individuals. This condition is characterized by CSF-enriched OCBs with undefined specificity, although some increased antiviral reactivity is found both in the serum and CSF. While it needs further characterization, a genetic trait interacting with common infections is suggested. The recurrence risk of this condition is approximately five times higher than the 3–4% recurrence risk for manifest MS reported for sibs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004150070130
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  • 20
    Electronic Resource
    Electronic Resource
    Perspectives in pediatric neurosurgery (2000)
    Springer
    Child's nervous system 16 (2000), S. 809-820 
    Details
    ISSN: 1433-0350
    Keywords: Keywords Pediatric neurosurgery ; Molecular biology ; Genetics ; Novel therapeutics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The new millennium beckons for novel advances in the diagnosis and treatment of pediatric neurosurgical conditions. Almost every aspect of pediatric neurosurgery has changed over the last decade. Undoubtedly with the application of knowledge in molecular biology to human disease many aspects of neurosurgery, especially neuro-oncology and the field of neuro-developmental anomalies, will change appreciably over the next decade. Overall, the trend in surgery in general and neurosurgery in particular is toward less invasive procedures and possibly non-surgical interventions. This review will briefly cover many of the important areas of pediatric neurosurgery. We will describe the state-of-the-art of our subspecialty and discuss possible future directions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003810000345
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  • 21
    Electronic Resource
    Electronic Resource
    Re-examination of (in)compatibility genotypes of two John Innes self-compatible sweet cherry selections (2000)
    Springer
    Theoretical and applied genetics 101 (2000), S. 234-240 
    Details
    ISSN: 1432-2242
    Keywords: Key words Cherry ; Genetics ; Compatibility ; Incompatibility ; Isoelectric focusing ; Prunus avium ; Ribonuclease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The (in)compatibility genotypes of two self-compatible sweet cherry selections, JI 2420 and JI 2434, originating from the John Innes Institute were re-examined. The selections and seedlings derived from them were analysed for stylar ribonucleases, which are known to correlate with S alleles, and the outcome of test crosses was recorded. JI 2420, which had been reported previously as S 3 S 4 ", where " indicates loss of pollen activity, was deduced to have the genotype S 4 S 4 ’. For JI 2434, which had been reported previously as S 3 S 4 0 , S 3 S 3 0 or S 3 S 3 ", where 0 indicates loss of pollen and stylar activity, two different clones were identified. One, at East Malling, was deduced to be S 3 "S 4 ; the other, at Ahrensburg, appeared to be S 3 S 3 " or S 3 S 3 0 .
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051474
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  • 22
    Electronic Resource
    Electronic Resource
    Characterisation and analysis of microsatellite loci in a mangrove species, Avicennia marina (Forsk.) Vierh. (Avicenniaceae) (2000)
    Springer
    Theoretical and applied genetics 101 (2000), S. 279-285 
    Details
    ISSN: 1432-2242
    Keywords: Key words Avicennia marina ; Microsatellite ; Mangrove ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  An enriched microsatellite library of the mangrove species Avicennia marina was constructed, in which 85.8% of the clones contained microsatellite sequences. Of the microsatellite repeat sequences isolated, 55.0% were di-nucleotides, 34.2% were tri-nucleotides, 50.0% were perfect, 24.2% were imperfect, and 15.0% were compound. Four different di-nucleotide repeats were isolated with repeat lengths ranging from 5 to 33; ten different tri-nucleotide repeats were isolated with repeat lengths ranging from 3 to 25. The most common di-nucleotide was the AC/TG repeat; the most common tri-nucleotide was the CCG/GGC repeat. Sixteen microsatellite sequences were selected for primer design, and 6 primers were selected to investigate the polymorphism detected among 15 individuals of A. marina from three natural populations in Australia. A total of 40 alleles were detected at 6 microsatellite loci. The number of alleles per microsatellite locus ranged from 5 to 13. On average, 7 alleles were detected per locus. All microsatellite loci showed high levels of gene diversity (heterozygosity), with values ranging from 0.53 to 0.88; the mean value of gene diversity was 0.70. Microsatellite loci were also tested for conservation across Avicennia species. There was a decline in amplification success with increasing divergence between Avicennia species. The results indicate that microsatellites are abundant in the Avicennia genome and can be valuable genetic markers for assessing the effects of deforestation and forest fragmentation in mangrove communities, which is an important issue for mangrove conservation and afforestation schemes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051480
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  • 23
    Electronic Resource
    Electronic Resource
    Dopamine D3 receptor variant and tardive dyskinesia (2000)
    Springer
    European archives of psychiatry and clinical neuroscience 250 (2000), S. 31-35 
    Details
    ISSN: 1433-8491
    Keywords: Key words Pharmacogenetics ; Genetics ; Risk factor ; Choreoathetotic movements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In the search for genetic factors contributing to tardive dyskinesia, dopamine receptor genes are considered major candidates. The dopamine D3 receptor is of primary interest as dopamine D3 receptor knock-out mice show locomotor hyperactivation resembling extrapyramidal side-effects of neuroleptic treatment. Furthermore, Steen and colleagues (1997) recently reported an association between tardive dyskinesia and a dopamine D3 receptor gene variant. In the present study we tried to replicate this finding. We investigated 157 patients with schizophrenia or schizoaffective disorder receiving long-term neuroleptic medication who never or persistently displayed tardive dyskinesia. As advanced age is a main risk factor for tardive dyskinesia, we also compared older patients with a long duration of schizophrenia not displaying tardive dyskinesia to younger patients with a shorter duration of the illness displaying tardive dyskinesia. However, we found no evidence that the dopamine D3 receptor gene is likely to confer susceptibility to the development of tardive dyskinesia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00007536
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  • 24
    Electronic Resource
    Electronic Resource
    Dopamine D4 receptor gene polymorphism and personality traits in healthy volunteers (2000)
    Springer
    European archives of psychiatry and clinical neuroscience 250 (2000), S. 203-206 
    Details
    ISSN: 1433-8491
    Keywords: Key words Dopamine receptor D4 ; Genetics ; Personality inventory ; Polymorphism ; Excitement-Seeking
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An association between long alleles of a variable number tandem repeat (VNTR) polymorphism in the dopamine receptor D4 gene and the extraversion related personality traits Excitement and Novelty Seeking has been reported in healthy subjects. In an attempt to replicate the previous findings, 256 healthy Caucasian volunteers were analysed for a potential relationship between the dopamine receptor D4 exon III VNTR polymorphism and Extraversion as assessed by the Revised Neo Personality Inventory (NEO PI-R). The present study did not yield evidence for an association between Extraversion and the dopamine receptor D4 polymorphism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004060070025
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  • 25
    Electronic Resource
    Electronic Resource
    ICAM-1 gene is not associated with multiple sclerosis in sardinian patients (2000)
    Springer
    Journal of neurology 247 (2000), S. 677-680 
    Details
    ISSN: 1432-1459
    Keywords: Key words Multiple sclerosis ; Genetics ; ICAM-1 gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An increased amount of the intercellular adhesion molecule (ICAM) 1 molecule has been found in the blood of actively relapsing multiple sclerosis (MS) patients, but is unclear whether this enhanced expression is partially causative of the MS process, or whether it is merely an epiphenomenon of the inflammatory-immunological reaction. Using the transmission disequilibrium test (TDT), we studied exon 4 and exon 6 polymorphism of the ICAM-1 gene from 157 families with both parents, one affected and one healthy sib coming from Sardinia, an Italian island having a high incidence and prevalence of MS. TDT did not show variation in the expected 50:50 frequency in transmission in either healthy or affected sibs, using phenotypic or genotypic analysis. Moreover, independence from the predisposing HLA-DRB1-DQA1-DQB1 haplotype was confirmed by TDT analysis performed on the patients stratified according to the presence or absence of the HLA-DRB1, DQA1, DQB1 Sardinian predisposing haplotypes. Our data suggest that the increased expression of the ICAM-1 molecule observed in both blood and periplaque microvessels may be considered a consequence of the inflammatory process rather than the result of a genetic variation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004150070109
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  • 26
    Electronic Resource
    Electronic Resource
    A novel hypersensitive resistance response against potato virus A in cultivar ’Shepody’ (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 401-408 
    Details
    ISSN: 1432-2242
    Keywords: Key words Complementary genes ; Extreme virus resistance ; Genetics ; Necrotic tubers ; Restricted virus distribution ; Solanum tuberosum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The potato cultivar ’Shepody’ is susceptible to a number of potato viruses including potato virus Y (PVY, potyvirus) but was found to possess extreme resistance to another potyvirus, potato virus A (PVA). ’Shepody’ plants were resistant to PVA infection in manual and graft inoculations. PVA replication was not detected in any of the inoculated plants by ELISA, an infectivity assay and RT-PCR. However, ’Shepody’ plants grafted with shoots containing PVA developed a novel symptomology which resembled a virus infection in appearance and in rate of translocation to the entire plant. Efforts to transmit the symptom-inducing agent manually failed. Graft-inoculation to potato virus indicator plants and PVA-susceptible potato plants showed that the symptom inducer was PVA at an extremely low concentration, detected using RT-PCR followed by Southern blot assay. Tubers from grafted but resistant ’Shepody’ plants had necrotic surfaces and internal spots. PVA was detected from necrotic areas but not from the non-necrotic ones. However, plants resulting from necrotic tubers were free from aerial leaf symptoms observed in grafted plants and produced non-necrotic normal tubers. A trace-back of the parental lineage of ’Shepody’ indicated that the resistance had been introgressed from the cultivar ’Bake King’. Analysis of progeny of a cross of resistant ’Shepody’ to the susceptible ’Goldrus’ indicated that this resistance is controlled by two independent dominant complementary genes in contrast to monogenic resistance reported for other potato viruses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220050053
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  • 27
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    Electronic Resource
    A pathophysiological study of neuronal ceroid lipofuscinoses in 17 patients: critical review and methodological proposal (2000)
    Springer
    Neurological sciences 21 (2000), S. S89 
    Details
    ISSN: 1590-3478
    Keywords: Key words Evoked potentials ; Ceroid lipofuscinoses ; Mutation ; Classification ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The importance of visual evoked potential (VEPs) and electroencephalography for diagnosing and distinghishing the infantile (INCL), late-infantile (LINCL) and juvenile (JNCL) forms of neuronal ceroid lipofuscinoses (NCL) is well established. Variant forms with protracted clinical courses and atypical symptoms have been described recently, whose neurophysiological characteristics sometimes overlap those of LINCL and JNCL. It is unclear whether these variant forms are due to phenotypic variability of known genetic defects, or represent new mutations. Twenty-eight NCL patients have been diagnosed at our institute; a proportion of them were investigated genetically. In 17 we performed neurophysiological investigations including VEPs, brainstem auditory (BAEP) and upper limb somatosensory (SEP) evoked potentials. We found typical and diagnostic electrophysiological involvement of the visual system in 8 patients with classic forms of NCL. Furthermore, the distinctive features of the multimodal evoked potentials in most of the six patients with variant NCL suggest that these are distinct genetic entities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100720070046
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  • 28
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    Electronic Resource
    Cavernous angiomas of the nervous system in Italy: clinical and genetic study (2000)
    Springer
    Neurological sciences 21 (2000), S. 129-134 
    Details
    ISSN: 1590-3478
    Keywords: Key words Nervous system ; Cavernous angiomas ; Genetics ; Onset symptoms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We performed a clinical and genetic study of patients affected by cavernous angiomas (CA) of the nervous system. We examined initial signs and symptoms in sporadic and familial cases. We obtained clinical, neuroimaging and genetic data on 15 Italian patients with CA of the nervous system with positive, doubtful or apparently negative family history. Genetic markers surrounding three different gene regions (7q, 3q and 7p) were analysed. In one small family, genetic linkage was consistent with all chromosome loci. In another family with the unusual association of cerebral and spinal CA, linkage with chromosome 7q and, likely, 7p was excluded, while linkage with locus 3q was possible. Our results indicate that Italian families with CA may show genetic heterogeneity. Non-specific and subtle onset symptoms hide the presence of CA within families. Patients with multiple CA may have silent cerebral lesions confirming the low penetrance of clinical signs in spite of radiological ones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100720070087
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  • 29
    Electronic Resource
    Electronic Resource
    Alcohol-sensitive hereditary essential myoclonus with dystonia: a study of 6 Brazilian patients (2000)
    Springer
    Neurological sciences 21 (2000), S. 373-377 
    Details
    ISSN: 1590-3478
    Keywords: Key words Myoclonus-dystonia ; Essential myoclonus ; Dystonia ; Alcohol ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We present the clinical profile of a group of patients with myoclonus and dystonia sensitive to alcohol and address these cases in the context of essential myoclonus. Six patients from 4 families were selected: 4 men and 2 women with myoclonus affecting predominantly the arms. Active movements of these segments elicited the dystonic and myoclonic movements. A marked improvement with alcohol intake was seen. Laboratory findings including EEG, SSEP, and cranial CT and MRI were normal. Surface EMG recording showed bursts with duration of 30–112 ms in 3 patients. One patient showed a triphasic recording pattern (agonist-antagonist-agonist) of ballistic type. Our findings suggest that the myoclonus-dystonia disorder is present in Brazilian patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100720070053
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  • 30
    Electronic Resource
    Electronic Resource
    The apolipoprotein multigene family: Structure, expression, evolution, and molecular genetics (1989)
    Springer
    Journal of molecular medicine 67 (1989), S. 225-237 
    Details
    ISSN: 1432-1440
    Keywords: Atherosclerosis ; Apolipoprotein ; Gene expression ; Genetics ; Evolution ; Gene duplication ; Lipid binding ; DNA polymorphism ; Hypercholesterolemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The plasma apolipoproteins can be classified into two subgroups: the soluble apolipoproteins including apolipoprotein (apo) A-I, A-II, A-IV, C-I, C-II, C-III, and E, and the apoBs including apoB-100 and apoB-48. The soluble apolipoproteins have very similar genomic structures, each having a total of three introns at the same locations; apoA-IV is an exception in that it has lost its first intron. Using the exon/intron junctions as reference points, we can obtain an alignment of the coding regions of all the soluble apolipoprotein genes. The mature peptide regions of the genes are almost completely made up of tandem repeats of 11 codons. The part of mature peptide region encoded by exon 3 contains a common block of 33 codons, whereas the part encoded by exon 4 contains a much more variable number of internal repeats of 11 codons. On the basis of the degree of homology of the various sequences, and the pattern of the internal repeats in these genes, an evolutionary tree has been proposed for the soluble apolipoprotein genes. ApoB-100 differs considerably from the soluble apolipoproteins. It is the largest apolipoprotein containing 4536 amino acid residues. Two types of internal repeats are identified in apoB-100: amphipathic α-helical repeats and proline-containing repeats with high β-sheet content. The apoB gene contains 29 exons and 28 introns. Its evolutionary relationship to the soluble apolipoprotein genes is unclear. The 3′ end of the apoB gene contains a region of variable number of tandem 12–16-base pair repeats. We have applied the polymerase chain reaction technique to characterize this highly polymorphic locus. The same technique can be used to accurately type other variable number of tandem repeats loci. Finally, apoB-48 was shown to be the product of an RNA editing mechanism involving an intestinal mRNA that has an in-frame UAA stop codon resulting from a C→U change in the codon CAA encoding Gln-2153 in apoB-100 mRNA. Using a molecular approach to apolipoprotein synthesis, structure and genetic analysis, we have generated information important to our understanding of lipoprotein metabolism; we also uncovered unexpected experimental results that are relevant to general cell and molecular biology and molecular evolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01717324
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  • 31
    Electronic Resource
    Electronic Resource
    The genetic predisposition to fibrocalculous pancreatic diabetes (1989)
    Springer
    Diabetologia 32 (1989), S. 45-51 
    Details
    ISSN: 1432-0428
    Keywords: Genetics ; insulin gene ; DQβ gene ; fibrocalculous pancreatic diabetes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fibrocalculous pancreatic diabetes (previously known as tropical pancreatic diabetes) is a rare cause of diabetes confined to countries within the tropical belt. The aetiology of fibrocalculous pancreatic diabetes is thought to be environmental although the agent(s) is unknown. We have investigated a possible genetic basis of this disease by looking for restriction fragment length polymorphisms of genes implicated in the aetiology of diabetes mellitus. Seventy-six Dravidian patients with fibrocalculous pancreatic diabetes were studied, and the restriction fragment length polymorphisms obtained compared to racially matched control subjects (n=94), patients with Type 2 (non-insulin-dependent) diabetes (n=87) and Type 1 (insulin-dependent) diabetes (n=58). No association of fibrocalculous pancreatic diabetes was found with restriction fragment length polymorphisms of the insulin receptor gene. Although no association of fibrocalculous pancreatic diabetes was found with polymorphism of the HLA DRα/DQα/DXα genes, an association was found with the Taq 1 restriction fragment length polymorphisms of the DQβ gene (DQβ T2/T6 present in 39% of patients with fibrocalculous pancreatic diabetes compared to 19% in control subjects; p=0.01; corrected p value=0.04) which is similar to that found in Type 1 but not Type 2 diabetes. An association of fibrocalculous pancreatic diabetes was also found with the hypervariable region in the 5-prime flanking region of the insulin gene; 40% of patients possessed the class 3 allele compared to 9.5% of control subjects p=0.0001; corrected p value=0.0008). In Type 2 diabetes, similar results were obtained with 33% subjects possessing the class 3 allele (p value compared to control subjects=0.0005; corrected p value=0.004). This study suggests that fibrocalculous pancreatic diabetes has a genetic component in its aetiology. Furthermore, its origin might be related to an individual with part of the genetic predisposition to diabetes (Type 1 or Type 2) who additionally has evidence of chronic calcific pancreatitis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00265403
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  • 32
    Electronic Resource
    Electronic Resource
    Population biology of two land snails (Mesomphix spp.): variation among six southern appalachian sites with differing disturbance histories (1989)
    Springer
    Oecologia 79 (1989), S. 372-382 
    Details
    ISSN: 1432-1939
    Keywords: Logging disturbance ; Land gastropods ; Ecology ; Genetics ; Population
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ecological and genetic properties of two North American terrestrial gastropods (Mesomphix spp.) were characterized in paired control and previously logged watersheds in two North Carolina forests (Coweeta and the Great Smoky Mountains National Park) of the Southern Appalachian Biosphere Reserve Cluster. Shell growth was greater in the control sites, but density and mortality were largely independent of prior logging history and forest reserve. Based on starch gel electrophoresis data, both species showed their highest levels of genetic diversity in the Coweeta forest, the component of the reserve cluster which had the most extensive and variable history of logging disturbance. M. subplanus also exhibited higher levels of heterozygosity in logged than in control watersheds, and M. andrewsae showed over twice as many rare alleles in disturbed sites as in control sites. F-statistic analysis depicted both excess levels of homozygosity and moderate genetic differentiation among the populations, reflecting the effects of small population size and perhaps drift and inbreeding. Estimated gene flow was relatively low. These results correspond to the recent finding by Bryant et al. (1987) and others on the effects of bottlenecks, and to the contrasting history of habitat instability of the two major study forests.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00384317
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  • 33
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    Electronic Resource
    Convulsant properties of GABA antagonists and anticonvulsant properties of ethanol in selectively bred Long- and Short-Sleep mice (1989)
    Springer
    Psychopharmacology 98 (1989), S. 544-548 
    Details
    ISSN: 1432-2072
    Keywords: Ethanol ; Bicuculline ; Picrotoxin ; Seizures ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The convulsant potency of bicuculline, a GABA antagonist, was shown to be greater in Short-Sleep (SS) mice than in Long-Sleep (LS) mice. LS mice, selectively bred for lengthy ethanol-induced narcosis, had longer latencies to myoclonus and clonus following administration of bicuculline and picrotoxin than did ethanol-resistant SS mice. SS mice were also more susceptible to pentylenetetrazol-induced myoclonus, but not clonus. F1 hybrids showed bicuculline seizure sensitivity intermediate to the two parent lines. Ethanol weakly inhibited bicuculline-induced myoclonus in both LS and SS mice. Clonus was clearly antagonized by ethanol in both lines, but to a similar degree. These data provide evidence for a GABAergic role in geno-type-dependent sensitivity to ethanol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00441957
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  • 34
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    Electronic Resource
    Cocaine produces low dose locomotor depressant effects in mice (1989)
    Springer
    Psychopharmacology 99 (1989), S. 147-150 
    Details
    ISSN: 1432-2072
    Keywords: Locomotor activity ; CNS depression ; Cocaine ; Mice ; Behavior ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Cocaine produces several behavioral effects, most notably locomotor stimulation. Biochemically, cocaine is known to inhibit reuptake at the three monoamine transporter sites, and may have highest affinity at the serotonin transporter. Serotonin augmentation has been associated with decreases in behavioral activity, but cocaine has not been reported to produce behavioral depressant effects except at high doses which cause stereotypy and disruption of behavior. This study examined the effects of relatively low doses of cocaine, in the range of 0.1–10 mg/kg, on locomotor activity in C57BL/6J and DBA/2J mice. A biphasic dose-response curve was seen for both strains. At the lowest doses, activity was depressed. As the dose of cocaine increased, activity returned to baseline, and at the highest doses, increases in locomotor activity were found. DBA/2J mice were depressed at a lower dose of cocaine than were C57BL/6J mice; however, C57BL/6J mice showed locomotor depression over a broader range of doses. Activity was maximally depressed at 0.1 mg/kg for DBA/2J mice, and maximally depressed at 0.3 mg/kg for C57BL/6J mice. Thus, low doses of cocaine are shown to produce significant decreases in locomotor activity in two strains of mice. It is postulated that these low doses of cocaine which depress locomotor activity do so via inhibition of serotonin uptake, resulting in potentiation of serotonergic activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00442799
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  • 35
    Electronic Resource
    Electronic Resource
    Genotype-dependent effects of GABAergic agents on sedative properties of ethanol (1989)
    Springer
    Psychopharmacology 98 (1989), S. 518-523 
    Details
    ISSN: 1432-2072
    Keywords: Ethanol ; GABA ; Bicuculline ; Sedation ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two lines of mice, selectively bred for differential sensitivity to the soporific effects of ethanol (ETOH), were administered GABAergic drugs in an effort to evaluate a role for GABA in ETOH sensitivity. ETOH sensitive Long-Sleep mice (LS) showed potentiated ETOH sedation when administered bicuculline, muscimol and aminooxyacetic acid (AOAA). ETOH-insensitive SS mice exhibited reduced ETOH sedation in the presence of the antagonists, bicuculline and picrotoxin, and potentiated sedation in the presence of muscimol and AOAA. These changes in narcosis duration were interpreted as central effects, since blood ethanol levels at waking from ETOH sedation varied with GABAergic drug treatment. Picrotoxin antagonized pentobarbital-induced nacrosis in both lines, but to a greater extent in SS mice. These and other experiments with a genetically heterogeneous stock suggest GABA involvement in genotype-dependent ETOH sensitivity, but do not support a simple role of GABA receptor involvement.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00441952
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  • 36
    Electronic Resource
    Electronic Resource
    Modification of ethanol effects by bicuculline: genotype-dependent responses and inheritance (1989)
    Springer
    Psychopharmacology 98 (1989), S. 549-555 
    Details
    ISSN: 1432-2072
    Keywords: Ethanol (ETOH) ; GABA ; Bicuculline ; Sedation ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Genetic influences on the interaction between ethanol (ETOH) and gamma-aminobutyric acid (GABA) neurotransmitter systems were eveluated with a survey of responses to coadministration of ETOH and a GABA antagonist, bicuculline, in a battery of inbred mouse strains. The selectively bred ETOH-sensitive Long-Sleep (LS) mice, the relatively ETOH-resistant Short-Sleep (SS) mice, and a genetically heterogeneous stock (GHS) were also evaluated. The effect of bicuculline on ETOH-induced sedation, hypothermia, and blood ethanol content upon recovery from sedation was assessed. Inheritance of these responses was also examined using F1 hybrids. The effect of bicuculline on ETOH-produced narcosis varied widely among stocks and included antagonism, potentiation, and no effect. Changes in ETOH-induced narcosis produced by bicuculline were accompanied by changes in blood ethanol concentrations consistent with an hypothesis of altered central nervous system sensitivity to ETOH. Knowledge of a strain's seizure susceptibility to the GABA antagonist or of its sensitivity to the hypnotic effects of ETOH were of no predictive value in estimating the outcome of coadministration studies, suggesting at least partially separate genetic influences on each phenotype. In cross-breeding studies there was commonly dominance toward a profile of bicuculline antagonism of ETOH narcosis but different patterns of dominance were observed for seizure susceptibility, again inicating separate genetic control. The results suggest considerable complexity of GABAergic involvement in genotype-dependent ETOH sensitivity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00441958
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  • 37
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    Electronic Resource
    Homology and distribution of CO dehydrogenase structural genes in carboxydotrophic bacteria (1989)
    Springer
    Archives of microbiology 152 (1989), S. 335-341 
    Details
    ISSN: 1432-072X
    Keywords: Carboxydotrophic bacteria ; Plasmids ; CO dehydrogenase subunits ; N-terminal sequences ; Oligonucleotides ; Hybridization ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The 17 (S), 30 (M) and 87 kDa (L) subunits of CO dehydrogenases from the CO-oxidizing bacteria Pseudomonas carboxydoflava, Pseudomonas carboxydohydrogena and Pseudomonas carboxydovorans OM5 were isolated and purified. The N-terminal sequences of same subunits from different bacteria showed distinct homologies. Dot blot hybridization employing oligonucleotide probes derived from the sequences of the S-subunit of P. carboxydovorans OM5 and the M-subunit of P. carboxydohydrogena and DNA of the plasmid-containing CO-oxidizing bacteria Alcaligenes carboxydus, Azomonas B1, P. carboxydoflava, P. carboxydovorans OM2, OM4 and OM5 indicated that all genes encoding these subunits reside on plasmids. That in P. carboxydovorans OM5 CO dehydrogenase structural genes are located entirely on plasmid pHCG3 was evident from the absence of hybridization employing DNA from the cured mutant strain OM5-12. CO dehydrogenase structural genes could be identified on the chromosome of the plasmid-free bacteria Arthrobacter 11/x, Bacillus schlegelii, P. carboxydohydrogena and P. carboxydovorans OM3. There was no example of a plasmid-harboring carboxydotrophic bacterium that did not carry CO dehydrogenase structural genes on the plasmid. The N-terminal sequences of CO dehydrogenase structural genes were found to be conserved among carboxydotrophic bacteria of distinct taxonomic position, independent of the presence of plasmids. It is discussed whether this might be the consequence of horizontal gene transfer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425170
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    The use of eye movement dysfunctions in exploring the genetic transmission of schizophrenia (1989)
    Springer
    European archives of psychiatry and clinical neuroscience 239 (1989), S. 43-48 
    Details
    ISSN: 1433-8491
    Keywords: Schizophrenia ; Eye movements ; Genetics ; Twins ; Latent trait
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Eye movement dysfunctions have been found in a large number of schizophrenic patients and in about half of their first-degree relatives. The distribution of these traits within the families of schizophrenic patients suggests a model of genetic transmission that fits an autosomal dominant model, which we have called the “genetic latent trait model.” The model, with seven parameters, was fitted to a U.S. population and the model was cross-validated on an independent Norwegian sample. Although the model does not invalidate other, more conventional solutions to the puzzle of schizophrenic transmission, such as multifactorial transmission, the latent trait model does more easily permit linkage studies and therefore will allow refutation or support from the use of molecular genetics techniques.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01739743
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  • 39
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    Genetical control and linkage relationships of isozyme markers in sugar beet (B. vulgaris L.) (1989)
    Springer
    Theoretical and applied genetics 78 (1989), S. 97-104 
    Details
    ISSN: 1432-2242
    Keywords: Beta vulgaris ; Sugar beet ; Isozymes ; Genetics ; Linkage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Five isozyme systems were genetically investigated. The different separation techniques, the developmental expression and the use as marker system in sugar beet genetics and breeding is discussed. Isocitrate dehydrogenase was controlled by two genes. The gene products form inter- as well as intralocus dimers, even with the gene products of the Icd gene in B. procumbens and B. patellaris. Adenylate kinase was controlled by one gene. Three different allelic forms were detected, which were active as monomeric proteins. Glucose phosphate isomerase showed two zones of activity. One zone was polymorphic. Three allelic variants, active as dimers, were found. Phosphoglucomutase also showed two major zones of activity. One zone was polymorphic and coded for monomeric enzymes. Two allelic forms were found in the accessions studied. The cathodal peroxidase system was controlled by two independent genes, of which only one was polymorphic. The gene products are active as monomers. Linkage was found between red hypocotyl color (R) and Icd 2. Pgm 1, Gpi 2, Ak 1 and the Icd 2-R linkage group segregated independently.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00299761
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    Optimising visual selection in early clonal generations of potato based on genetic and economic considerations (1989)
    Springer
    Theoretical and applied genetics 78 (1989), S. 665-671 
    Details
    ISSN: 1432-2242
    Keywords: Solanum tuberosum ; Genetics ; Breeding ; Plant appearance ; Economy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In 1985, 1986 and 1987, 600 clones were visually assessed at harvest on plant appearance. The clones were harvested 80 days after planting in the first year, in the following years after approximately 80 days as well as after 145 days. The correlation coefficients between years and between harvest times were low to medium. Simulating different selection intensities using the performance of these 600 clones in two successive years, the relation between selection pressure in the first year and the retained proportion of well performing clones in the second year was described. Including the costs of testing, the most economic selection procedure was calculated. This procedure consisted in testing 1,579 first-year clones and 499 second-year clones for every 100 third-year clones required. The optimal period of the main evaluation in the second clonal year is at ware potato harvest time. This selection procedure also provides good selection possibilities for underwater weight and foliage maturity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00262562
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  • 41
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    A comparison of muscle precursor replication in crush-injured skeletal muscle of Swiss and BALBc mice (1989)
    Springer
    Cell & tissue research 255 (1989), S. 385-391 
    Details
    ISSN: 1432-0878
    Keywords: Myogenesis ; Muscle regeneration ; Genetics ; Autoradiography ; Tritiated thymidine ; Mouse (Swiss;BALBc)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Muscle precursor replication in Swiss mice, in which muscle regeneration is exceptionally vigorous, was compared with previous data for regeneration in BALBc mice. The tibialis anterior muscles of 23 male and 15 female inbred Swiss SJL/J mice were crush injured, and tritiated thymidine injected into mice at various times after injury to label replicating muscle precursors. Lesion samples were taken 10 days after injury, processed for autoradiography, and grain counts of myotube nuclei analysed. Muscle regeneration was more vigorous in male compared with female Swiss mice, and in both was strikingly greater than that in BALBc mice in which there was extensive fibrous connective tissue throughout the lesions. Autoradiographic analysis showed that muscle precursor replication started at 24 hours in Swiss mice, 6 hours earlier than the onset at 30 hours in BALBc mice. Muscle precursor replication appeared to be more active 96 hours after injury in female Swiss compared with male BALBc and male Swiss mice respectively, although numbers of precursor cells replicating at other times were similar. It is not known whether the slight difference in onset of muscle precursor replication can alone account for the more complete muscle regeneration seen in Swiss mice. Similar studies were carried out in 11 male and 10 female F1 hybrid (SJL/J x BALBc) mice. Analysis of labelled myotube nuclei showed that muscle precursors did not synthesise DNA prior to 30 hours after injury, and regeneration resembled that of the parental BALBc strain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224122
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  • 42
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    Tryptophan auxotrophic mutants in Aspergillus niger: Inactivation of the trpC gene by cotransformation mutagenesis (1989)
    Springer
    Molecular genetics and genomics 219 (1989), S. 282-288 
    Details
    ISSN: 1617-4623
    Keywords: Aspergillus ; Genetics ; Transformation ; trpC lacZ gene fusion ; Gene replacement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Aspergillus niger tryptophan auxotrophic mutants have been isolated after UV irradiation of conidiospores. The mutants belong to two different complementation groups, trpA and trpB, which complement each other in heterokaryons. Neither of the mutations could be complemented with the cloned A. niger trpC gene. To obtain A. niger trpC mutants in a direct way, gene inactivation by cotransformation was performed. For this purpose an in-frame gene fusion between the A. niger trpC and Escherichia coli lacZ genes was constructed and shown to be functionally expressed after introduction into A. niger by cotransformation with the pyrA gene as selective marker. Among the β-galactosidase expressing cotransformants, obtained with either circular or linearized vectors, no trpC mutants were detected, even after enrichment. Such mutants, however, could be obtained by cotransformation of A. niger with specific fragments of the fusion gene. Biochemical analysis of the cotransformants indicated that in nearly all cases the fusion gene had replaced the wild-type trpC gene. Genetic analysis showed that the trpC mutation is not linked to any of the A. niger loci described so far. The trpC mutants can be complemented by the cloned A. niger trpC gene as well as by the A. nidulans trpC gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00261189
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    Non-linear stochastic response of marine vehicles (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 169-183 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The dynamic behaviour of marine vehicles in extreme sea states is a matter of great concern following some recent and dramatic mishaps. The complex problem of its prediction can be approached from the study, yet of broader scope, of non-linear dynamic systems subjected to stochastic excitations. However, a general non-linear stochastic dynamic theory is not yet available.A new technique, the so-called linearize-and-match method, for predicting the response statistics of non-linear systems, is presented. Essentially, the technique involves the construction of an infinite series of linear systems aimed at the prediction of the response statistical moments of a given order.The linear systems are successively defined by linearizing the original, non-linear system and matching the Volterra functional model response statistics to the desired order. The linear system for predicting second order statistics is shown to coincide with the one obtained using the method of equivalent linearization.Response probability distributions can be constructed from the knowledge of such statistics. Particular attention is devoted to the distribution of maximum entropy and its justification in such underdetermined moment problems.Finally, applications to the roll motion of ships serve to exemplify as well as to assess the accuracy and the versatility of the overall method. Response distributions of maxima so predicted compare very well with digital simulation estimates.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270114
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    F.E. solution of a vertically averaged model for regional land subsidence (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 215-230 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In this paper a mathematical model is presented, based on the application of an averaging technique, in which the equations governing the behaviour of saturated porous media are integrated (averaged) over the smallest dimension of the domain of the problem (thickness). This results in a two dimensional model, in which the three dimensional nature of the problem is accounted for. In fact, the solution is sought in terms of the mean values over the thickness of the field variables and of the transverse displacement components. For the solution of the resulting governing equations a partitioned procedure is employed, which improves the efficiency of the method. The proposed model is very useful in solving problems in which the spatial nature prevents the applications of two dimensional models.Examples are presented, which illustrate the validity of this approach.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270117
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  • 45
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    Some recent developments in numerical modelling of fracture toughness in brittle matrix composites (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 233-255 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Finite element analysis was used to study the fracture toughening of a ceramic by a stress induced dilatant transformation of second phase particles. The finite element method was based on a continuum theory which modelled the composite as subcritical material. Transient crack growth was simulated in the finite element mesh by a nodal release technique. The crack's remote tensile opening load was adjusted to maintain the near-tip energy release rate at the level necessary for crack advance. The transformation zone surrounding the crack developed as the crack propagated through the composite. Resistance curves were computed from the analysis; and the results show that during crack advance maximum toughness is achieved before a steady state is reached.The toughening effect of a crack-bridging ductile phase in a brittle material may be predicted if ligament deformation is characterized. A plastically deforming ligament constrained by surrounding elastic matrix material is modelled using finite elements and the relevant toughness enhancement information extracted. Comparison is made to model experiments as well as to toughness measured for technologically important materials. The results suggest that debonding along the interface between the ligament and the matrix may enhance the toughening effect of a ductile phase.
    Additional Material: 21 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270203
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  • 46
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    Fatigue life estimation of graphite/epoxy laminates under consideration of delamination growth (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 323-341 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A closed form approach to the assessment of the fatigue life of graphite/epoxy laminates under cyclic tension-compression loading has been developed. The model is mechanistic and uses cyclic energy release rates for prediction of delamination growth and of critical delamination sizes which induce buckling and the final failure of the laminates. Tests performed with graphite/epoxy specimens of stacking order [0n, φm]s with severed central plies [φ], and of stacking order [02, +45, 02, -45, 0, 90]s with a central unloaded hole, indicate good correlation between estimated values and observed delamination growth, critical buckling strength of separated plies and load cycles to failure.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270208
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  • 47
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    Analysis of viscoelastic structural elements in the frequency domain (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 429-436 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The paper presents a formulation in the frequency domain for the viscoelastic material behaviour of structural elements. This approach is equally valid for deterministic forces, but also in the case of probabilistic descriptions of those forces. The method takes advantage of readily available experimental data and shows how to introduce them in e.g. finite element formulations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270213
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    Conference diary (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 449-452 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270215
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  • 49
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    A dual adaptive procedure for the automatic determination of iteration parameters for Chebyshev acceleration (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 483-499 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Chebyshev acceleration for a symmetrizable basic iterative method u(n+1) = Gu(n) + k; requires estimates of the extreme eigenvalues m(G) and M(G) of the iteration matrix G. Adaptive procedures are often used in order to obtain good estimates for m(G) and M(G). Some existing adaptive procedures are able to give an estimate of either m(G) or M(G) but not both on any given iteration. In this paper we present an adaptive procedure which can estimate both m(G) and M(G) at the same time and which has other useful properties. Numerical results are given which show the new procedure usually requires fewer iterations than previous procedures.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270305
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  • 50
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    Experience with the conjugate gradient method for stress analysis on a data parallel supercomputer (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 523-546 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The storage requirements and performance consequences of a few different data parallel implementations of the finite element method for domains discretized by three-dimensional brick elements are reviewed. Letting a processor represent a nodal point per unassembled finite element yields a concurrency that may be one to two orders of magnitude higher for common elements than if a processor represents an unassembled finite element. The former representation also allows for higher order elements with a limited amount of storage per processor. A totally parallel stiffness matrix generation algorithm is presented. The equilibrium equations are solved by a conjugate gradient method with diagonal scaling. The results from several simulations designed to show the dependence of the number of iterations to convergence upon the Poisson ratio, the finite element discretization and the element order are reported. The domain was discretized by three-dimensional Lagrange elements in all cases. The number of iterations to convergence increases with the Poisson ratio. Increasing the number of elements in one special dimension increases the number of iterations to convergence, linearly. Increasing the element order p in one spatial dimension increases the number of iterations to convergence as pα, where α is 1·4-1·5 for the model problems.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270307
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    On an SSOR matrix relationship and its consequences (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 559-570 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A matrix relationship connecting the Jacobi and the Symmetric Successive Overrelaxation (SSOR) matrices associated with a k-cyclic consistently ordered matrix A is presented. Next the equivalence of the SSOR method and a certain monoparametric k-step one for the solution of the linear algebraic system Ax = b is established. The aforementioned equivalence can be exploited to derive regions of convergence, optimum parameters involved, etc. of the two iterative methods above. This is done by studying the simplest of the two methods that is the monoparametric k-step one. To show how the idea works the case k = 2 is very briefly discussed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270309
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    On a class of preconditioned iterative methods on parallel computers (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 637-654 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The standard implementations of iterative solvers for finite element and finite difference methods frequently use a diagonal (Jacobi) preconditioner, particularly for element-by-element schemes. However, for such methods the actual order of the condition number with respect to mesh size is not reduced by the preconditioner. In the present paper we describe an iterative method where, in addition, the condition number is reduced by an order of magnitude. Moreover, the scheme may also be implemented as an element-by-element method. The method uses a generalized SSOR preconditioner and a wave front or multi-frontal ordering of the mesh nodes. For a general irregular finite element mesh a striped irregular wave front ordering may be used. The performance of the method as well as various iterative acceleration techniques for a parallel computer are examined in the numerical studies.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270314
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    Correction (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. ii 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280102
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  • 54
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    Geometrically non-linear formulation for three dimensional curved beam elements with large rotations (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 43-73 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper presents a geometrically non-linear formulation (GNL) for the three dimensional curved beam elements using the total Lagrangian approach. The element geometry is constructed using co-ordinates of the nodes on the centroidal or reference axis and the orthogonal nodal vectors representing the principal bending directions. The element displacement field is described using three translations at the element nodes and three rotations about the local axesThe element displacement field has also been described in the literature using Euler parameters, Milenkovic parameters, or Rodriges parameters representing the effects of large rotations.. The GNL three dimensional beam element formulations based on these element approximations are restricted to small nodal rotations between two successive load increments. The element formulation presented here removes such restrictions. This is accomplished by retaining non-linear nodal terms in the definition of the element displacement field, and the consistent derivation of the element properties. The formulation presented here is very general and yet can be made specific by selecting proper non-linear functions representing the effects of nodal rotations. The details of the element properties are presented and discussed. Numerical examples are also presented to demonstrate the behaviour and the accuracy of the elements. A comparison of the results obtained from the present formulation with those available in the literature using a linearized element approximation clearly demonstrate the superiority of the formulation in terms of large load steps, large rotations between two load steps and extremely good convergence characteristics during equilibrium iterations. The displacement approximation of these elements is fully compatible with the isoparametric curved shell elements (with large rotations), and since the elements possess offset capability, these elements can also serve as stiffeners for the curved shells.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280106
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    Evaluation of boundary integrals for plate bending (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 75-93 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The alternative to quadrature, as a procedure for dealing with the integrations required in the direct boundary element method (DBEM), is to carry out the integration analytically and code the results directly. The potential benefits are efficient computer programs; the avoidance of numerical instability; and generally, better accuracy. The technique is developed in this paper.Serious problems arise when Gauss quadrature is employed for the integration of functions which contain, or are close to singularities. A numerical integration approach may fail at the first stage of the analysis, that is, during the assembly of the discrete equations; or it may fail at the subsequent stage of computing domain points near the boundary. The severity of the problem is dependent both on the strength of the singularity, and on geometry. These points are illustrated with examples.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280107
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    Frictionless geometrically non-linear contact using quadratic programming (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 127-144 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The successive quadratic programming (SQP) method is used with the finite element method (FEM) to solve frictionless geometrically non-linear contact problems involving large deformations of the elastica in the presence of flat rigid walls. To formulate the SQP problems, the potential energy (PE) is expanded in a Taylor series of second order in displacement increments about a configuration near a contact solution. The SQP problems consist of minimizing the Taylor expansion of the PE subject to the inequality constraints which represent contact. The quadratic programming (QP) method is made part of a Newton-Raphson (NR) search in which the QP corrections are made when a NR step does not satisfy the constraints. A revised simplex method developed by Rusin is used to solve the QP problems. The elastica is modelled with a total Lagrangian FEM developed by Fried. Solutions are obtained for the end loaded buckled elastica in point contact with a rigid wall and for a uniformly loaded elastica in regional contact with a rigid wall. The problems are also solved using a penalty method. The results obtained for the point contact problem are compared to an analytical solution. Calculations were made to obtain numerical information on maximum load step size and the number of inverse operations required for each load step. Cases in which the elastica stiffened substantially as a result of the initiation of contact are also discussed.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280110
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    The FDM in arbitrary curvilinear co-ordinates - formulation, numerical approach and applications (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 261-277 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The basic concept, formulation and numerical application of a fully automatic version of the finite difference method (FDM) on a two-dimensional manifold embedded in three-dimensional Euclidean space are presented. This version of the FDM was developed in order to enable automatic solution of problems formulated in arbitrary curvilinear co-ordinate systems in terms of covariant derivatives (e.g. shell equations).In the classical version of the FDM all operations in the curvilinear co-ordinates (the derivation of base vectors, curvature tensors and so on) have to be performed manually. The goal of the present work was to transfer this job to a computer, in order to minimize the user's effort during the numerical formulation of the physical problem. The relevant version of the fully automatized program FIDAMF, based on the FDM on arbitrary irregular grids,1,2 has been worked out. This code performs automatically all stages of the numerical analysis, starting from the mesh generation and approximation of the shape of the manifold, through computation of necessary objects on this manifold, to the solution of linear or non-linear problems formulated in terms of covariant derivatives.The method has been extended to the analysis of problems in which the co-ordinate system changes during the computation (e.g. the analysis of large deformations in the convectional description). This version of the curvilinear FDM was applied to the analysis of large deformations of hyperelastic membrane shells.The approach and the numerical routines, although used here with the FDM, can be combined with any other approximation method, in particular the finite element method.
    Additional Material: 16 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620280203
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    Approximate direct-search minimax circuit optimization (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 359-368 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A direct-search optimization strategy, involving pattern-searches, pattern-moves and a simplex algorithm, has been applied to a number of frequency-domain circuit problems. We show that an approximate minimax result can be obtained with our simple approach, which includes using a modified minimax error function. In the examples attempted, the method comes quite close to the accuracy, if not the efficiency, of true minimax optimizers, and yields an accuracy as good as or better than a least-pth (p = 10) gradient optimizer. The method is broadly appropriate wherever it is difficult or inconvenient to calculate the gradients required for conventional minimax optimization.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620280208
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    Implementation of curvilinear geometry into p-version HT plate elements (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 431-443 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The formulation of the recently presented hybrid-Trefftz (HT) p-version elements1 has thus far been restricted to straight-sided polygonal elements. The present paper removes this limitation. Two alternative formulations are studied. In the first one any curvilinear geometry is represented accurately but the rigid body modes are recovered only in the limit as the p-refinement level is increased. In contrast, the second formulation represents the rigid modes exactly while the actual curvilinear geometry is approached with increasing accuracy as the p-refinement level is increased. The practical efficiency of the two alternative approaches is studied and assessed on pertinent examples of thin plates in bending.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620280212
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    Books received (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 477-478 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280217
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    Conference diary (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 483-487 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280220
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    A discrete shear triangular nine D.O.F. element for the analysis of thick to very thin plates (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 533-560 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper deals with the formulation and the evaluation of a new three node, nine d.o.f. triangular plate bending element valid for the analysis of thick to thin plates. The formulation is based on a generalization of the discrete Kirchhoff technique to include the transverse shear effects. The element, called DST (Discrete Shear Triangle), has a proper rank and is free of shear locking. It coincides with the DKT (Discrete Kirchhoff Triangle) element if the transverse shear effects are not significant. However, an incompatibility of the rotation of the normal appears due to shear effects. A detailed numerical evaluation of the characteristics and of the behaviour of the element has been performed including patch tests for thin and thick plates, convergence tests for clamped and simply supported plates under uniform loading and evaluation of stress resultants. The overall performance of the DST element is found to be very satisfactory.
    Additional Material: 19 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620280305
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    Efficient optimization of integrated aerodynamic-structural design (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 593-607 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The introduction of composite materials is having a profound effect on the design process. Because these materials permit the designer to tailor material properties to improve structural, aerodynamic and acoustic performance, they require a more integrated multidisciplinary design process. Because of the complexity of the design process numerical optimization methods are required.The present paper is focused on a major difficulty associated with the multidisciplinary design optimization process - its enormous computational cost. We consider two approaches for reducing this computational burden: (i)development of efficient methods for cross-sensitivity calculation using perturbation methods; and (ii) the use of approximate numerical optimization procedures. Our efforts are concentrated upon combined aerodynamic-structural optimization. Results are presented for the integrated design of a sailplane wing. The impact of our computational procedures on the computational costs of integrated designs is discussed.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620280308
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    Structural modifications simulated by virtual distortions (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 645-666 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A numerical strategy for the simulation of structural modifications by virtual distortions is proposed. Two cases of structural modification are considered: the first concerns modifications of material distribution, and the second modifications of local constitutive relations (e.g. unilateral constraints for stresses or deformations). A formaulation of the fundamental equations of the simulation method is presented. These equations are applicable to the general structural modification problem of a truss-like structure. Then numerical algorithms which refer to particular applications, such as progressive collapse analysis or the analysis of structures with gaps, are discussed.The versatility of the method is illustrated with a number of examples, and the computational advantages of structural modification by the virtual distortion method are discussed.
    Additional Material: 16 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620280312
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    Computational plasticity, Edited by D. R. J. Owen, E. Hinton and E. Oñate, Pineridge Press, Swansea, U.K., 1987. No. of pages: 1865. ISBN 0-906674-61-1 (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 725-726 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280317
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    First-order design sensitivities for transient conduction problems by an adjoint method (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 733-752 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An adjoint approach is presented for the design sensitivity analysis of transient conduction problems. Variations of a general design functional are expressed in explicit form with respect to all design quantities, i.e. material properties, shape, applied thermal loads including convection, and initial conditions. The methodology incorporates the mutual energy between the real and adjoint thermal problems and a geometric mapping to describe shape variations. Finite element implementation of the method is discussed and an example is provided. Some potential difficulties that might be encountered when using the adjoint method with the finite element method are addressed. These involve the application of impulse loadings and Dirac temperature fields in the adjoint loadings.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620280402
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    A comparison of direct and preconditioned iterative techniques for sparse, unsymmetric systems of linear equations (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 801-815 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In this paper we compare direct and preconditioned iterative methods for the solution of nonsymmetric, sparse systems of linear algebraic equations. These problems occur in finite difference and finite element simulations of semiconductor devices, and fluid flow problems.We consider five iterative methods that appear to be the most promising for this class of problems: the biconjugate gradient method, the conjugate gradient squared method, the generalized minimal residual method, the generalized conjugate residual method and the method of orthogonal minimization. Each of these methods was tested using similar preconditioning (incomplete LU factorization) on a set of large, sparse matrices arising from finite element simulation of semiconductor devices. Results are shown where we compare the computation time and memory requirements for each of these methods against one another, as well as against a direct method that uses LU factorization to solve these problems.The results of our numerical experiments show that preconditioned iterative methods are a practical alternative to direct methods in the solution of large, sparse systems of equations, and can offer significant savings in storage and CPU time.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620280406
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    On the modelling of scalar and mass transport in combustor flows (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 861-877 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The results of a numerical study of swirling and non-swirling combustor flows with and without density variations are presented. Constant-density arguments are used to justify closure assumptions invoked for the transport equations for turbulent momentum and scalar fluxes, which are written in terms of density-weighted variables. Comparisons are carried out with measurements obtained from three different axisymmetric model combustors. The three experiments cover recirculating flow, swirling flow and variable-density, swirling flow inside model combustors. Together, they offer wide ranging flow conditions to test the validity of the models. Results show that the Reynolds stress/flux models do a credible job of predicting constant-density, swirling and non-swirling combustor flows with passive scalar transport. However, their improvements over algebraic stress/flux models are marginal. The extension of the constant-density models to variable-density flow calculations shows that the models are equally valid for such flows. Therefore, the present results argue well for the adoption of constant-density models for variable-density flows until a successfully validated variable-density model is available.
    Additional Material: 14 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620280410
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    Numerical modelling of wave propagation using parabolic approximation with a boundary-fitted co-ordinate system (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 37-55 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: With a boundary-fitted curvilinear co-ordinate system, the parabolic approximation is applied to the mildslope equation to describe the wave propagation. Both refraction and diffraction are included in the numerical model. Because the shoreline coincides with one of the curvilinear co-ordinates, the numerical model can be used to compute wave propagations near an irregular shoreline.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620270105
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    Study of the behaviour of oscillatory waves in a lagoon (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 103-112 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270109
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    A three dimensional global weather prediction model using a finite element scheme for vertical discretization (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 129-144 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A global three dimensional model for numerical weather prediction is described. It uses spheric harmonic basis functions with triangular truncation in the horizontal and a finite element discretization for the vertical. Model experiments are used to compare this model with another version, which uses a finite difference scheme for vertical discretization.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620270111
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    The influence of the form of the log-conductivity covariance on non-Fickian dispersion in random permeability fields (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 185-193 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The paper deals with non-Fickian dispersion of inert solutes in random permeability fields. Attention is focused critically on the statistical characterization of the porous medium which affects pollutant dispersion in groundwater. After a brief account of recent results of stochastic theories of transport in porous media and of the fundamental indications of large-scale field experiments, it is inferred from numerical studies that the particular choice of an analytical form of covariance of log-conductivity has a poor influence on the overall dispersion process. In fact, different covariance structures with the same macroscale (a measure of the distance between two points beyond which the permeability ceases to be correlated) yield very similar dispersion processes. The result has a noteworthy bearing on field studies of pollutant dispersion in groundwater because it underlines the reliability of exponential correlation structures yielding analytical expression for time-varying macrodispersion coefficients.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620270115
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    Preface (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 231-231 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270202
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    A consistent tangent stiffness matrix for three-dimensional non-linear contact analysis (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 1803-1812 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A consistent tangent stiffness matrix for the analysis of non-linear contact problems is presented. The associated element has three or four nodes and establishes contact between three-dimensional structures like solids and shells. It accounts for the non-linear kinematics of large deformation analysis and guarantees a quadratic convergence rate. Two formulations, the penalty method and the Lagrange multiplier method, are investigated.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620280807
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    On the accuracy of some domain-by-domain algorithms for parallel processing of transient structural dynamics (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 1855-1874 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Two domain-by-domain algorithms, suitable for coarse-grained parallel processing analysis of the transient structural dynamics equation, are investigated for accuracy. The application under specific consideration is the analysis of three-dimensional framed structures subjected to time-varying loading. The domain-by-domain approaches attempt to include the advantageous aspects of both conditionally stable explicit algorithms, which require no simultaneous solution of equations and employ simple communication, and unconditionally stable implicit algorithms, which permit large time steps. The alternating group explicit algorithm is developed for finite element analysis, and its accuracy is investigated for a linear formulation. The group implicit algorithm is extended to non-linear finite element analysis, and its accuracy is investigated for the frame dynamics application. Both algorithms are shown to provide inadequate accuracy for practical time step sizes.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620280811
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    Accuracy in finite element computation for eigenfrequencies (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 1929-1949 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In this paper we propose an original numerical method to get upper and lower bounds for the eigenfrequencies of an elastic structure.This method is based on a ‘static’ formulation for eigenvalue problems built up from a new quotient Rs which is defined on a load space. From Rs properties, upper and lower bounds for the exact eigenfrequencies are proved. The application of the method requires the solution of an eigenvalue problem of finite dimension and the computation of a constant which is characteristic of the discretization subspace. Results of numerical tests are given for the vibration problem of an elastic clamped membrane.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620280815
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    A new BEM formulation for acoustic eigenfrequency analysis (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 1965-1967 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280817
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    Conference diary (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 1971-1975 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280819
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    Efficient approximation concepts using second order information (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 2041-2058 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The primary goal of this paper is to show how second derivative information can be used in an effective way in structural optimization problems. The basic idea is to generate such an information at the expense of only one more ‘virtual load case’ in the sensitivity analysis part of the finite element code. To achieve this goal a primal-dual approach is employed, that can also be interpreted as a sequential quadratic programming method.Another objective is to relate the proposed method to the well known family of approximation concepts techniques, where the primary optimization problem is transformed into a sequence of non-linear explicit subproblems. When restricted to diagonal second derivatives, the new approach can be viewed as a recursive convex programming method, similar to the ‘Convex Linearization’ method (CONLIN), and to its recent generalization, the ‘Method of Moving Asymptotes’ (MMA).This new method has been successfully tested on simple problems that can be solved in closed form, as well as on sizing optimization of trusses. In all cases the method converges faster than CONLIN, MMA or other approximation techniques based on reciprocal variables.
    Additional Material: 3 Ill.
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    Numerical study of incompressible fluids in unbounded domains (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 2203-2218 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The aim is to build up and test a numerical method to calculate the velocity of stationary two-dimensional flows. Both inviscid and viscous fluids are considered. They act in the unbounded domain surrounding a given profile and a stream function is introduced. A variational procedure, adapted to unbounded domains, reduces the problem to solving a finite sequence of hormonic equations, posed in bounded domains. Some profiles are tested using a finite element method.
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    URL: http://dx.doi.org/10.1002/nme.1620280915
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    A study of stabilization and projection in the 4-node Mindlin plate element (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 2223-2238 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In this paper, a Mindlin plate element is formulated based on the Hellinger-Reissner principle and the γ-technique. The stiffness consists of a constant stress (one-point quadrature) matrix and a stabilization matrix. The stabilization matrix is compared with those previously proposed. In addition, the element uses a projection to modify the nodal displacements so that the patch test is satisfied. The projection matrix is based on a mode decomposition. Several numerical cases are presented, and it is shown that the mode decomposition projection is necessary both for satisfaction of the patch test and convergence.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620281003
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    Modal parameter identification using Z-transforms (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 2307-2321 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A method for the time domain identification of modal parameters of a vibrating structure using Z-transformation sequences is presented in this paper.This identification proceeds using the Z-transfer function of a vibrating structure from which an auto-regressive and moving-average (ARMA) model of the vibrating structure is derived. From this ARMA model and time domain data, the modal parameters can be identified. The time domain data can be obtained from single point or multiple shaker excitation modal testing. To demonstrate the application and efficiency of the method, a test on a simulated cantilever beam is presented.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/nme.1620281008
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    The dynamic analysis of a suspended cable due to a moving load (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 2361-2381 
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    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The dynamic behaviour of a saggy suspension cable under a moving load was investigated. First of all, the updated Lagrangian formulation and the finite element method were used to derive the property matrices of a saggy suspension cable in order to define the discretized equations of motion. Then, the Jacobi method was applied to the determination of the natural frequencies and the mode shapes of the suspended cable. The moving-load-induced dynamic responses of the saggy suspended cable were obtained by using the Newmark direct integration method incorporated with the Newton-Raphson iteration technique. The influence of some pertinent factors, such as speed of moving load, ratio of axial rigidity to total cable weight (AE/0m̄g0L) and ratio of moving load mass to total cable mass, is the key point of the dynamic analysis.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620281011
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    A simple stress error estimator for Hybrid-Trefftz p-version elementsA preliminary version1 of this paper has been presented at NUMETA 87 Conference, The University of Swansea, 6-10 July 1987 (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 211-236 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An a posteriori error estimator is presented which allows a good pointwise evaluation of the error in predicted stresses and can easily be implemented in existing FE codes. Although this estimator has especially been developed for and tested on p-version Hybrid-Trefftz (HT) elements, it is anticipated that it can also be applied to conventional conforming p-version elements. The practical efficiency of the estimator is illustrated through the solution of various plate bending problems by using the HT p-version Kirchhoff plate elements.2
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280115
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  • 85
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    A moving boundary circulation model for regions with large tidal flats (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 245-260 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A numerical model is developed for computing two-dimensional circulation in coastal regions dominated by large tidal flat motion. This model is based on the shallow water momentum and continuity equations being operated upon by the Galerkin finite element method. The particular advantage of the model lies in its ability to accommodate a changing domain boundary. This is accomplished by adopting finite elements that change shape so as to consistently move with the water's edge. Application of the model to the Kuwait Bay is described, and the associated results on circulation are given.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280202
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  • 86
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    A boundary element method analysis of electrostatics in a tank during filling operations (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 315-329 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Electrostatic charging inside a tank is analysed numerically using the boundary integral method. The electrostatic charge is transmitted to the tank through a charged liquid. Profiles for the charge density and potential are obtained in the tank during the filling operation. The analysis is based on the equation governing the transport of charge and Poisson's equation. The results are characterized by two dimensionless parameters, the dimensionless Debye length given by the Debye length divided by the height of the tank, and the number Pe defined as a Peclet number. The results show where the maximum charge density and potential occur and give a prediction of when during the filling operation a hazardous situation may occur.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280206
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  • 87
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    Assumed strain stabilization procedure for the 9-node Lagrange shell element (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 385-414 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An assumed strain (strain interpolation) method is used to construct a stabilization matrix for the 9-node shell element. The stabilization procedure can be justified based on the Hellinger-Reissner variational method. It involves a projection vector which is orthogonal to both linear and quadratic fields in the local co-ordinate system of each quadrature point. All terms in the development involve 2 × 2 quadrature in the 9-node element. Example problems show good accuracy and an almost optimal rate of convergence.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280210
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  • 88
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    Delaunay triangulation of non-convex planar domains (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 2695-2707 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper investigates the possibility of integrating the two currently most popular mesh generation techniques, namely the method of advancing front and the Delaunay triangulation algorithm. The merits of the resulting scheme are its simplicity, efficiency and versatility. With the introduction of ‘non-Delaunay’ line segments, the concept of using Delaunay triangulation as a means of mesh generation is clarified.An efficient algorithm is proposed for the construction of Delaunay triangulations over non-convex planar domains. Interior nodes are first generated within the planar domain. These interior nodes and the boundary nodes are then linked up together to produce a valid triangulation. In the mesh generation process, the Delaunay property of each triangle is ensured by selecting a node having the smallest associated circumcircle. In contrast to convex domains, intersection between the proposed triangle and the domain boundary has to be checked; this can be simply done by considering only the ‘non-Delaunay’ segments on the generation front.Through the study of numerous examples of various characteristics, it is found that high-quality triangular element meshes are obtained by the proposed algorithm, and the mesh generation time bears a linear relationship with the number of elements/nodes of the triangulation.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620281113
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  • 89
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    Conference diary (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 2713-2714 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620281119
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  • 90
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    A mixed-variable continuously deforming finite element method for parabolic evolution problems. Part III: Numerical implementation and computational results (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 2715-2760 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In Part I of this paper,1 the conceptual framework of a rate variational least squares formulation of a continuously deforming mixed-variable finite element method was presented for solving a single evolution equation. In Part II2 a system of ordinary differential equations with respect to time was derived for solving a system of three coupled evolution equations by the deforming grid mixed-variable least squares rate variational finite element method. The system of evolution equations describes the coupled heat flow, fluid flow and trace species transport in porous media under conditions when the flow velocities and constituent phase transitions induce sharp fronts in the solution domain. In this paper, we present the method we have adopted to integrate with respect to time the resulting spatially discretized system of non-linear ordinary differential equations. Next, we present computational results obtained using the code in which this deforming mixed finite element method was implemented. Because several features of the formulation are novel and have not been previously attempted, the problems were selected to exercise these features with the objective of demonstrating that the formulation is correct and that the numerical procedures adopted converge to the correct solutions.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620281203
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  • 91
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    Error estimates and adaptive refinement for plate bending problems (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 2839-2853 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The Zienkiewicz-Zhu error estimator is shown to be effective in problems of plate flexure. When used in conjunction with triangular elements and an adaptive mesh generator allowing a prescribed size of elements to be developed, very fast adaptive convergence for results of specified accuracy is achieved.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620281209
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  • 92
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    Selective refinement/derefinement algorithms for sequences of nested triangulations (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 2889-2906 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The construction of changing sequences of irregular and nested triangulations, based on the use of conforming refinement/derefinement algorithms for triangulations, is presented and discussed. This strategy is particularly appropriate to combine adaptivity and full multigrid algorithms for dealing with moving fronts or fluid dynamics problems. It is shown that the quality of all the triangulations iteratively generated depends only on the geometric characteristics of the initial grid. A data structure suitable to create, manage and modify series of nested triangulations as well as the main features of the DEREF prototype package are described, and numerical examples are given.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620281212
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  • 93
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    Tracing the equilibrium path beyond simple critical points (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 2923-2941 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A unified presentation of some popular continuation procedures used in the non-linear finite element analysis of structural mechanics is introduced. An extension of the elliptical constraint equation proposed by Crisfield is given. It is shown that in the proposed procedure real roots can always be obtained in solving the iterative change of the load parameter. Updated weighting factors are introduced in the constraint equation in order to get better convergence characteristics in the case when localized deformations occur. For bifurcation points a modification of Rheinboldt's branching procedure is presented. Post critical response after limit and bifurcation points is determined in some numerical examples.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620281214
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  • 94
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    Error estimates and convergence rates for various incompressible elements (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 2191-2202 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This note reports numerical experiments on the efficiency of simple error estimates derived earlier1 applied to incompressible mixed or related penalty type formulations. The rate of convergence and performance of various mixed elements is compared. Numerical results from a driven cavity and an incompressible elastic problem demonstrate that the T6B1/3D and T6/3C elements give a faster rate of convergence than the T6/1D element. However, in the case of a plane extrusion analysis (stronger singularity), the rate of convergence for the T6B1/3D element drops and is inferior to that of the T6/1D, while the T6/3C element still proves superior to the other two elements.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280914
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  • 95
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    A C0 finite element formulation for thin-walled beams (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 2239-2255 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Timoshenko's and Vlasov's beam theories are combined to produce a C0 finite element formulation for arbitrary cross section thin-walled beams. Section properties are generated using a curvilinear co-ordinate system to describe the cross section dimensions. The element includes both shear and warping deformations caused by the bending moments and the bimoment. A Gauss quadrature order is employed which exactly integrates the bending and warping stiffness matrices and provides a reduced integration order for the shear stiffness matrices. Numerical results are presented for a channel section cantilever beam. The influence of shear deformation is investigated and the calculated results are shown to be in excellent agreement with the classical solutions.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620281004
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  • 96
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    Virtual crack extension methods for non-linear materials (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 929-942 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The virtual crack extension technique is a very efficient and accurate approach to fracture mechanics calculations in the numerical analysis of bodies containing cracks using the finite element method. A few variations of the technique have been described in the literature, and have been extensively used in linear elastic fracture mechanics, where good validation has frequently been available with accepted alternative solutions for standard tests. However, for non-linear materials extra complications arise in the technique, particularly in describing material response in a compatible manner. It is shown that, using few assumptions, a very competitive virtual crack extension technique based, on a direct minimization of potential energy is available for elastic non-linear elastic materials. Such materials can be closely approximated to elastic-plastic behaviour for monotonically increasing loads including mechanical, thermal and body force forms. The technique is described and demonstrated via examples to be in good agreement with alternative fracture parameter evaluations when evaluated in the same computer system, BERSAFE.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280414
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    Numerical methods in transient and coupled problems, R. W. Lewis, E. Hinton, P. Bettess and B. A. Schrefler, Wiley (Chichester) 1987. No. of pages: 350. ISBN: 0 471 91200X (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 28 (1989), S. 979-979 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620280419
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  • 98
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    Wave plan computation method in study of the Calvi Bay erosion in Corsica, France (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 71-85 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A study of linear monochromatic wave propagation is presented, based on a theory of potentials. The usual Berkhoff equation has been extended by the addition of partially pervious solid boundary effects and the bed friction.The problem has been solved by a hybrid finite element method including the effect of singular local elements such as the end of breakwaters or wharfs. This numerical method confirms the interest in quadratic Lagrangian finite elements.The comparisons with analytical solutions and existing numerical results show the validity of the method. Some original examples also prove the good performance of the proposed computation method.As an example, the study of the erosion of the beach of Calvi Bay in Corsica, France is presented. The phenomenon had started already in 1960, but the problem began to be very severe four years ago, after the implementation of a new harbour in 1982 and buildings, hotels, restaurants, and a main sewer on the beach. To consider the impact of these constructions and other factors like waves, currents and geomorphological aspects, the studies were divided into four parts: sedimentological, currents, wave propagation and geomorphological.This paper will describe the results of a complete two years study on the site, from February 1986 to December 1987.Findings show that the erosion process is due to the rise of the relative sea level with, as a catalyst, tourist behaviour and the implementation of the new constructions.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270107
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    Calculation of the force coefficients of a tubular jacket structural member with an appurtenance by the discrete vortex method (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989), S. 153-167 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Jacket structures have many sub-sea appurtenances attached to them. For example, a typical jacket structure has hundreds of sacrificial anodes attached to its members. The fluid loading of these structures is calculated using Morison's formula. The force coefficients used in the equation are based on experiments carried out, for the most part, on single cylinders in laboratories in ideal flow. There are very few experimental data available for the fluid loading of cylinders with appurtenances. Moreover, it is not possible to calculate theoretically the loading on such configurations in flows of practical interest using approaches such as the finite element method. However, appurtenances can contribute significantly to the overall loading on a structure. This paper presents the preliminary theoretical work that has been carried out as part of a programme to establish a rational method for estimating the fluid loading on tubular members with appurtenances.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270113
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  • 100
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    Masthead (1989)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 27 (1989) 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620270201
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