Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of geodesy 71 (1997), S. 533-540 
    ISSN: 1432-1394
    Keywords: Key words. Geodetic surface integrals ; Numerical integration ; Parallel computer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying
    Notes: Abstract. Geodetic surface integrals play an important role in the numerical solution of geodetic boundary-value problems. In many cases they can be evaluated using fast methods in the frequency domain (FFT). However, this is not possible in general, because the domain of integration may be non-trivial (as is the surface of the Earth), the kernel function may not be of convolution type, or the data distribution may be heterogeneous. Therefore, fast evaluation strategies are also required in the space domain. They are more difficult to design because only one property is left where a more or less fast evaluation strategy can be built upon: the potential type of the kernel function. Consequently, the idea is not to replace well-established frequency domain techniques, but to supplement them. Our approach to this problem goes in two directions: (1) we use advanced cubature methods where the integration nodes automatically densify in the vicinity of the evaluation points; (2) we use powerful computer hardware, namely MIMD computers with distributed memory. This enables us to evaluate geodetic surface integrals of any practical complexity in reasonable time and accuracy. This is shown in a numerical example.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of geodesy 72 (1998), S. 530-546 
    ISSN: 1432-1394
    Keywords: Key words. Hadamard finite part ; Cauchy principal values ; numerical integration ; Galerkin boundary element method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying
    Notes: Abstract. Efficient numerical computation of integrals defined on closed surfaces in ℝ3 with non-integrable point singularities that arise in physical geodesy is discussed. The method is based on the use of polar coordinates and the definition of integrals with non-integrable point singularities as Hadamard finite part integrals. First the behavior of singular integrals under smooth parameter transformations is studied, and then it is shown how they can be reduced to absolutely integrable functions over domains in ℝ2. The correction terms that usually arise if the substitution rule is formally applied, in contrast to absolutely integrable functions, are calculated. It is shown how to compute the regularized integrals efficiently, and, numerical efforts for various orders of singularity are compared. Finally, efficient numerical integration methods are discussed for integrals of functions that are defined as singular integrals, a task that typically arises in Galerkin boundary element methods.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of geodesy 73 (1999), S. 543-554 
    ISSN: 1432-1394
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying
    Notes: Abstract. One of the most serious practical limitations of boundary element methods for gravity field determination is that they cannot make efficient use of existing satellite geopotential models. Three basic approaches to solving the problem are developed: (1) alternative representation formulas; (2) modified kernel functions of classical representation formulas; and (3) modified trial and test spaces. The three methods are tested and compared for the altimetry–gravimetry II boundary value problem. It is shown that there is in fact a significant improvement when compared to the pure boundary element solution. Most promising is the method of multiscale trial and test spaces which, in addition, yields sparse system matrices.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of geodesy 73 (1999), S. 491-500 
    ISSN: 1432-1394
    Keywords: Key words. Geodetic boundary value problems ; Altimetry ; gravimetry problems ; Vertical geodetic datum ; Gravitational boundary value problems ; Pseudo-boundary value problems
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying
    Notes: Abstract. A review of recent progress and current activities towards an improved formulation and solution of geodetic boundary value problems is given. Improvements stimulated and required by the dramatic changes of the real world of geodetic measurements are focused upon. Altimetry–gravimetry problems taking into account various scenarios of non-homogeneous data coverage are discussed in detail. Other problems are related to free geodetic datum parameters, most of all the vertical datum, overdetermination or additional constraints imposed by satellite geodetic observations or models. Some brief remarks are made on pseudo-boundary value problems for geoid determination and on purely gravitational boundary-value problems.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-1920
    Keywords: Key words Neurofibromatosis type 1 (NF1) ; Optic glioma ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report two children with neurofibromatosis type 1 showing enhancing masses on MRI suggesting neoplasms in the chiasm and hypothalamic region. In both patients no visual or endocrinal dysfunction was present. On serial MRI spontaneous partial remission was found, implying that a cautious approach to therapeutic management of similar cases should be taken.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-0827
    Keywords: Bone mineral density ; Dual-energy X-ray absorptiometry ; Reference range ; Exclusion criteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract A cross-sectional, population-based study of 238 randomly selected females and 224 males with German ethnic background (aged 20–80 years) was carried out to establish lumbar spine bone mineral density (BMD) values, using dual X-ray absorptiometry (DXA), for a German population. Comparison was made to the reference range provided by the manufacturer of the DXA equipment. No sex difference in peak spine BMD was found in our study (1.091±0.114 g/cm2 for males versus 1.070±0.113 g/cm2 for females, n.s.). Different patterns of bone loss could be detected in both sexes. In premenopausal women there was no significant correlation between age and BMD (y = 1.044 + 0.00047x, r=0.03, P=0.73) whereas reduction of female BMD at the spine was demonstrated in postmenopausal women (y = 1.189−0.0041x, r=-0.28, P=0.01), underscoring the important role of the menopause for later manifestation of spinal osteoporosis in women. In contrast, in males we found no significant change of BMD with aging (y = 1.071−0.0007x, r=-0.08, P=0.25). Employing commonly used exclusion criteria, BMD values of the study subjects were found mostly within the normal range of BMD. The major finding of our study was good concordance between female data of our study population and the reference data provided by the manufacturer. Clinically significant discrepancies between our data and the Hologic reference range for males could be detected. Our data on males (30–39 years of age) were up to 7% lower than those provided by the manufacturer, probably due to differences in sampling procedures.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-0428
    Keywords: Key words Exercise ; non-insulin-dependent diabetes mellitus ; abdominal fat ; blood pressure ; heart rate ; cholesterol ; high-density lipoprotein ; high-density lipoprotein-2 ; high-density lipoprotein-3 ; triglycerides.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Non-insulin-dependent diabetes mellitus (NIDDM) is associated with an increased cardiovascular risk. Glycaemic control alone is often insufficient to control diabetic dyslipidaemia and other cardiovascular risk factors associated with NIDDM. The present trial was designed to evaluate the effects of physical activity as an adjunct to standard diabetes therapy on the lipid profile, blood pressure, glycaemic control, weight and body fat. Sixteen well-controlled (HbA1 c 7.5 %) patients with NIDDM participated in a regular aerobic exercise training programme at 50–70 % maximal effort over 3 months. Thirteen age- and sex-matched patients with NIDDM served as a control group. The 3-month intervention with an increase in physical activity from 92 (mean ± SD) ± 79 to 246 ± 112 min per week (p 〈 0.001) by means of a structured activity programme resulted in significant improvement of plasma lipids with a 20 % decrease in triglycerides (p 〈 0.05), unchanged total cholesterol and increases in high-density lipoprotein and high-density lipoprotein-3 subfraction of 23 % (p 〈 0.001) and 26 % (p 〈 0.001), respectively. Systolic and diastolic blood pressure decreased significantly from 138 ± 16 to 130 ± 17 mm Hg (p 〈 0.05) and 88 ± 10 to 80 ± 10 mmHg (p 〈 0.001), respectively. Resting heart rate decreased from 81 ± 13 to 74 ± 14 beats per minute (p 〈 0.001), waist-hip circumference ratio decreased from 0.96 ± 0.11 to 0.92 ± 0.10 (p 〈 0.001) and body fat decreased from 35.3 ± 7.2 to 33.0 ± 8.0 % (p 〈 0.001). These effects occurred independently of changes in body weight and glycaemic control, which did not change during the study. This study shows that improvement in physical fitness by introducing regular physical exercise as part of the treatment programme in patients with NIDDM results in a significant amelioration of their cardiovascular risk profile. [Diabetologia (1995) 38: 1313–1319]
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-0428
    Keywords: Exercise ; non-insulin-dependent diabetes mellitus ; abdominal fat ; blood pressure ; heart rate ; cholesterol ; high-density lipoprotein ; high-density lipoprotein-2 ; high-density lipoprotein-3 ; triglycerides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Non-insulin-dependent diabetes mellitus (NIDDM) is associated with an increased cardiovascular risk. Glycaemic control alone is often insufficient to control diabetic dyslipidaemia and other cardiovascular risk factors associated with NIDDM. The present trial was designed to evaluate the effects of physical activity as an adjunct to standard diabetes therapy on the lipid profile, blood pressure, glycaemic control, weight and body fat. Sixteen well-controlled (HbA1c 7.5%) patients with NIDDM participated in a regular aerobic exercise training programme at 50–70% maximal effort over 3 months. Thirteen age- and sex-matched patients with NIDDM served as a control group. The 3-month intervention with an increase in physical activity from 92 (mean ± SD) ±79 to 246±112 min per week (p〈0.001) by means of a structured activity programme resulted in significant improvement of plasma lipids with a 20% decrease in triglycerides (p〈0.05), unchanged total cholesterol and increases in high-density lipoprotein and high-density lipoprotein-3 subfraction of 23% (p〈0.001) and 26% (p〈0.001), respectively. Systolic and diastolic blood pressure decreased significantly from 138±16 to 130±17 mm Hg (p〈0.05) and 88±10 to 80±10 mmHg (p〈0.001), respectively. Resting heart rate decreased from 81±13 to 74±14 beats per minute (p〈0.001), waist-hip circumference ratio decreased from 0.96±0.11 to 0.92±0.10 (p〈0.001) and body fat decreased from 35.3±7.2 to 33.0±8.0% (p〈0.001). These effects occurred independently of changes in body weight and glycaemic control, which did not change during the study. This study shows that improvement in physical fitness by introducing regular physical exercise as part of the treatment programme in patients with NIDDM results in a significant amelioration of their cardiovascular risk profile.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1432-0584
    Keywords: Key words High-grade non-Hodgkin's lymphoma ; Methotrexate ; Leukoencephalopathy ; Neurotoxicity ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Aggressive polychemotherapy, intrathecal cytostatic prophylaxis and cranial irradiation have contributed to the remarkable improvement in the prognosis of acute lymphoblastic leukemia (ALL) and subtypes of high-grade non-Hodgkin's lymphoma (NHL) and the reduction of central nervous system (CNS) relapses. Early and late neurologic changes have been observed after different CNS-directed therapies. We report on the rare event of an acute tetraparesis after methotrexate (MTX) without other CNS-directed therapy. A young female with a diffuse large B-cell lymphoma developed signs of meningeal irritation a few hours after intrathecal prophylaxis with MTX, cytosine-arabinoside and dexamethasone. She recovered quickly. Ten days after her last course of systemic chemotherapy including high dose MTX she was admitted with a tetraparesis and motoric aphasia. A computer assisted tomography (CT) scan was normal. On magnetic resonance imaging (MRI) hyperintense white matter lesions were visible in the periventricular white matter. Initially, the radiologic signs were progressive while the patient's clinical condition improved. MRI controls after complete neurologic normalization revealed delayed partial regression of the white matter abnormalities. The patient has now been free of neurologic symptoms for 16 months. This case report demonstrates acute and subacute neurotoxic effects of MTX in the same patient and illustrates that radiologic CNS changes can persist irrespective of the disappearance of clinical symptoms.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Der Internist 39 (1998), S. 1253-1263 
    ISSN: 1432-1289
    Keywords: Schlüsselwörter Osteoporose ; Therapie ; Osteoporose ; postmenopausale ; Kalzium ; Osteoporose ; Vitamin D ; Osteoporose ; Östrogene ; Osteoporose ; Biphosphonate ; Osteoporose ; Fluoride ; Osteoporose ; Kalzitonin ; Osteoporose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Zum Thema Bei Osteoporosen werden primäre und sekundäre Formen sowie 2 Typen unterschieden. Typ I ist durch spongiosabetonten Knochenmasseverlust gekennzeichnet. Die in dieser Arbeit abgehandelte postmenopausale Osteoporose wird Typ I zugerechnet. Die senile Osteoporose wird Typ II zugeordnet, der durch einen generalisierten Verlust von Spongiosa und Kompakta charakterisiert ist. Die postmenopausale und die senile Osteoporose gehören zu den primären Osteoporoseformen. Für Erst- und Verlaufsdiagnostik zur Beurteilung therapeutischer Ergebnisse gilt die Osteodensitometrie im Wirbensäulenbereich und Oberschenkelhals als Goldstandard. Das entscheidende klinische Kriterium zur Bewertung des therapeutischen Nutzens eines Medikaments ist die Senkung der Frakturrate in prospektiven Studien. Über die therapeutische Optionen bei postmenopausaler Osteoporose (Kalzium, Vitamin D, Östrogene, Gestagene, Biophosphonate, selektive Östrogenrezeptormodulatoren, Kalzitonin und Fluoride) wird nachfolgend referiert.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...