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  • Numerical Methods and Modeling  (4)
  • Allozymes  (2)
  • Age  (1)
  • Cell death  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 183 (1977), S. 41-59 
    ISSN: 1432-041X
    Keywords: Imaginal discs ; Pattern formation ; Cell death ; Duplication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We describe the range of phenotypes caused by cell death when larvae of the heat-sensitive cell-lethal mutant,l(1)ts726 ofDrosophila, are subjected to heat treatment at different stages of development. When the treatment extends into the pupal period, certain bristles fail to develop but the disc derivatives are otherwise normal. Earlier treatments cause the replacement of sets of leg and eye-antennal markers by mirror image duplications of neighbouring sets. The results are compared in detail with those expected under a gradient model proposed earlier to account for the phenotype. It is found that although the results for the second leg are in excellent agreement with the predictions of the model, a more elaborate hypothesis is necessary to account for the eye-antennal disc data. Abnormal head patterns fall into several distinct categories, any one of which could be explained by postulating the existence of a gradient, if other categories did not also occur. The markers affected in each case belong to overlapping sets, and each category of pattern can be induced by heat treatments administered throughout the temperature-sensitive period. The statistical distribution of the data is such that only one category of pattern would be detected in a small scale experiment. The possible implications relative to pattern formation in normal development are discussed.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-2242
    Keywords: Segregation distortion ; Allozymes ; Pinus banksiana Lamb. ; Lethal allelism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Segregation ratios of allozymes in haploid female gametophytes obtained from viable seed were studied in a natural population of jack pine, Pinus banksiana. Stability of these ratios was assessed for three levels of the sexually reproductive crown as well as for four years of natural fertilization. Analyses of observed segregation ratios of four of five polymorphic isozyme loci showed good correspondence to the overall 1∶1 ratios expected for simple Mendelian inheritance. Allozymes of glucose-6-phosphate dehydrogenase did not segregate in the expected 1∶1 ratio. In addition, there were significant deviations from the expected segregation ratio for all the loci at some sampling positions on individual trees. Heterogeneity of segregation among trees, strata and years could be the result of pollen pool heterogeneity, segregation distortion and/or recessive lethal and semi-lethal gene combinations resulting in early embryo abortion. These types of segregation deviations in viable seed can affect the estimation of allele frequencies from bulked samples of a small number of individuals, the inference of heterozygosity/homozygosity of parental trees, and estimates of selfing rates.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-2242
    Keywords: Allozymes ; Peroxidase ; Leucine-aminopeptidase ; Linkage ; Lucerne ; Medicago
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The genetics of peroxidase and leucine-aminopeptidase isozymes was studied utilizing starch gel electrophoresis in the diploidsMedicago sativa L. (M. coerulea Less.) andM. falcata L. Three anodal and one cathodal sets of peroxidase isozymes identify four linked loci. In addition, two anodal sets of leucine-aminopeptidase isozymes identify two loci that may be linked. The allozymes at each of the loci segregated as expected for monomeric enzymes. However in several crosses there were deficiencies in the number of progeny in particular genotypic classes. This could result from the segregation of recessive deleterious genes linked to some of the allozyme alleles. This is the first report of multiple loci and multiple alleles determining isozymes inMedicago.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1439-6327
    Keywords: Age ; Ageing ; Flexibility ; Health ; Customary activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a representative survey of 1000 elderly men and women aged over 65 years living in their own homes, assessments have been made of flexibility measured as range of shoulder abduction in addition to health status, psychological well-being and reported customary activity. The results for shoulder abduction were approximately normally distributed and the mean values (±1 standard deviation) were as follows: — in men aged 65–74 years, 129 (±14)° and aged over 74 years, 121 (±19)°; in women aged 65–74 years, 124 (±19)° and aged over 74 years, 114 (±22)°. These mean values are about 30° less than those accepted for younger subjects. Nearly half the distribution falls below the accepted threshold level of 120° for adequate function. There were significant effects of sex and age (P〈0.001); women had poorer flexibility and the reduction with age amounted to 10° per decade. Multiple regression analysis showed that the effect of age was accounted for in part by health, strength and customary use. The effects of use were most marked in those with some disability. This suggests that maintained or increased use could offset some of the age-related loss of the range of shoulder movement.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 27 (1998), S. 41-55 
    ISSN: 0271-2091
    Keywords: unstructured mesh ; compressible flow ; transient flow ; mesh adaptation ; moving boundaries ; Delaunay triangulation ; Engineering ; Numerical Methods and Modeling
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The solution of high-speed transient inviscid compressible flow problems in three dimensions is considered. Discretization of the spatial domain is accomplished by the use of tetrahedral elements generated by Delaunay triangulation with automatic point creation. Methods of adapting the mesh to allow for boundary movement are considered and a strategy for ensuring boundary recovery is proposed. An explicit multistage time-stepping algorithm is employed to advance the flow solution. A number of examples are included to illustrate the numerical performance of the proposed procedures. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 28 (1998), S. 1325-1353 
    ISSN: 0271-2091
    Keywords: finite elements ; compressible flow ; artificial viscosity ; Engineering ; Numerical Methods and Modeling
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The performance of different shock capturing viscosities has been examined using our general fluid mechanics algorithm. Four different schemes have been tested, both for viscous and inviscid compressible flow problems. Results show that the methods based on the second gradient of pressure give better performance in all situations. For instance, the method constructed from the nodal pressure values and consistent and lumped mass matrices is an excellent choice for inviscid problems. The method based on L2 projection is better than any other method in viscous flow computations. The residual based anisotropic method gives excellent performance in the supersonic range and gives better results in the hypersonic regime if a small amount of residual smoothing is used. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 27 (1998), S. 57-80 
    ISSN: 0271-2091
    Keywords: high speed flow ; shock modelling ; numerical method ; computational fluid dynamics ; Engineering ; Numerical Methods and Modeling
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: In this paper we compare the performance of a new general algorithm developed recently in application to problems of high Mach number flows with the performance of specialised algorithms applicable only to such flows. It appears that the results for most examples compare well, the biggest difference occurring in that of high Mach number compression corner. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 27 (1998), S. 1-11 
    ISSN: 0271-2091
    Keywords: Engineering ; Numerical Methods and Modeling
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: No Abstract
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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