Search Results - (Author, Cooperation:E. Stephan)
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1Articles: DFG German National LicensesStaff View
ISSN: 0007-1269Topics: PsychologyURL: -
2Latest Papers from Table of Contents or Articles in PressStaff View
Publication Date: 2018-03-06Publisher: Oxford University PressPrint ISSN: 0955-792XElectronic ISSN: 1465-363XTopics: Computer ScienceMathematicsPublished by: -
3Latest Papers from Table of Contents or Articles in PressE. D. Lorenzen ; D. Nogues-Bravo ; L. Orlando ; J. Weinstock ; J. Binladen ; K. A. Marske ; A. Ugan ; M. K. Borregaard ; M. T. Gilbert ; R. Nielsen ; S. Y. Ho ; T. Goebel ; K. E. Graf ; D. Byers ; J. T. Stenderup ; M. Rasmussen ; P. F. Campos ; J. A. Leonard ; K. P. Koepfli ; D. Froese ; G. Zazula ; T. W. Stafford, Jr. ; K. Aaris-Sorensen ; P. Batra ; A. M. Haywood ; J. S. Singarayer ; P. J. Valdes ; G. Boeskorov ; J. A. Burns ; S. P. Davydov ; J. Haile ; D. L. Jenkins ; P. Kosintsev ; T. Kuznetsova ; X. Lai ; L. D. Martin ; H. G. McDonald ; D. Mol ; M. Meldgaard ; K. Munch ; E. Stephan ; M. Sablin ; R. S. Sommer ; T. Sipko ; E. Scott ; M. A. Suchard ; A. Tikhonov ; R. Willerslev ; R. K. Wayne ; A. Cooper ; M. Hofreiter ; A. Sher ; B. Shapiro ; C. Rahbek ; E. Willerslev
Nature Publishing Group (NPG)
Published 2011Staff ViewPublication Date: 2011-11-04Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: Animals ; Bayes Theorem ; *Biota ; Bison ; Climate Change/*history ; DNA, Mitochondrial/analysis/genetics ; Europe ; *Extinction, Biological ; Fossils ; Genetic Variation ; Geography ; History, Ancient ; Horses ; Human Activities/*history ; Humans ; Mammals/genetics/*physiology ; Mammoths ; Molecular Sequence Data ; Population Dynamics ; Reindeer ; Siberia ; Species Specificity ; Time FactorsPublished by: -
4Articles: DFG German National LicensesOlson, Kurt A. ; Kotecki, David E. ; Ricci, Anthony J. ; Lassig, Stephan E. ; Husain, Anwar
[S.l.] : American Institute of Physics (AIP)
Published 1995Staff ViewISSN: 1089-7623Source: AIP Digital ArchiveTopics: PhysicsElectrical Engineering, Measurement and Control TechnologyNotes: The resulting temperature distribution of a silicon wafer held by an electrostatic chuck (ESC) in an electron-cyclotron-resonance chemical vapor deposition (ECR-CVD) reactor is characterized and modeled. The effects of the clamping voltage VESC, pressure between the ESC and wafer PHe, and the surface finish and pattern on the ESC are investigated. Heat transfer coefficients between the wafer and various ESCs are determined experimentally. A model is developed to predict the temperature distribution at the surface of the wafer, and used to explain the experimentally observed temperature variations both within wafer and between different chucks. The model is then used to aid in the design of an ESC which provides improved temperature uniformity at the wafer surface. The results of this study indicate: (a) the thermal resistances across the interface between the wafer and ESC control both the absolute wafer temperature and the wafer temperature uniformity; (b) the surface roughness of the ESC and the size of the "contact'' regions are major design factors controlling the absolute temperature of the wafer—the temperature can be adjusted by varying the value of VESC and fine tuned by adjusting the value of PHe; (c) the nonuniform temperature distribution across the wafer surface is dictated by the surface pattern on the ESC, the variation in surface roughness, and the size of the ESC relative to the wafer; (d) wafer temperature variations from chuck to chuck are reduced by controlling the surface finish of the ESC and by ensuring that PHe is a dominant heat transfer mechanism; and (e) maximum uniformity in the temperature of the wafer is obtained when the radius of the ESC is matched as closely as possible to that of the wafer. We have shown that numerical heat transfer models can be used to optimize the geometry of the ESC to provide a uniform distribution of temperature across the surface of the wafer. © 1995 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesHARTNELL, GEORGE G. ; SAXTON, JANET M. ; FRIEDL, STEPHAN E. ; ABELA, GEORGE S. ; ROSENSCHEIN, URI
Oxford, UK : Blackwell Publishing Ltd
Published 1993Staff ViewISSN: 1540-8183Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: MedicineNotes: An ultrasonic thrombolysis device designed for intracoronary use was developed and evaluated in vitro to assess efficacy in achieving clot ablation without deleterious effects, such as heat generation and production of large particles during clot ablation. Studies on 31 samples with a bench-top version demonstrated that clot ablation was rapid (typically 2 mL in under 2 minutes) and no macroscopic particles were released. The fluid produced did not reclot. Studies with a clinical version of the device that can be passed through a IOFr PTCA guiding catheter confirmed that clot ablation was rapidly achieved. Little particulate material was produced and the maximum temperature achieved did not exceed 52°C. The device functions well in vitro, releasing little particulate material and causing limited local heating. It seems suitable for intracoronary use and will undergo further in vivo testing.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesMergenhagen, Stephan E. ; Bladen, Howard A. ; Hsu, Konrad C.
Oxford, UK : Blackwell Publishing Ltd
Published 1966Staff ViewISSN: 1749-6632Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: Natural Sciences in GeneralType of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesMikheev, Vladimir B. ; Laulainen, Nels S. ; Barlow, Stephan E.
College Park, Md. : American Institute of Physics (AIP)
Published 2000Staff ViewISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: A laminar flow tube reactor was designed and constructed to provide an accurate, quantitative measurement of a nucleation rate as a function of supersaturation and temperature. Measurements of nucleation of a supersaturated vapor of dibutylphthalate have been made for the temperature range from −30.3 to +19.1 °C. A thorough analysis of the possible sources of experimental uncertainties (such as defining the correct value of the initial vapor concentration, temperature boundary conditions on the reactor walls, accuracy of the calculations of the thermodynamic parameters of the nucleation zone, and particle concentration measurement) is given. Both isothermal and the isobaric nucleation rates were measured. The experimental data obtained were compared with the measurements of other experimental groups and with theoretical predictions made on the basis of the self-consistency correction nucleation theory. Theoretical analysis, based on the first and the second nucleation theorems, is also presented. The critical cluster size and the excess of internal energy of the critical cluster are obtained. © 2000 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesCharon, Jacques A. ; Metzger, Zvi ; Terrell Hoffeld, J. ; Oliver, Contance ; Gallin, John I. ; Mergenhagen, Stephan E.
Oxford, UK : Blackwell Publishing Ltd
Published 1982Staff ViewISSN: 1600-0765Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: MedicineNotes: Neutrophils (PMN) are considered to be key components in the protection of the periodontium against pathogenic bacteria. We therefore compared five of the major characteristics of peripheral blood PMN (PB-PMN) (adherence, chemotaxis, phagocytosis, oxidaiive metabolism, and lysosomal granules) to those of normal crevicular neutrophils (CR-PMN) isolated from the same individuals. The data indicate that the presence of Fc and C3b receptors, and the production of superoxide are similar in CR-PMN and PB-PMN. In addition, healthy gingival sulci harbor a high percentage of stimulated PMN as determined by the nitroblue tetrazolium (NBT) reduction assay. The percentage of CR-PMN which phagocytized opsonized red blood cells (RBC) was lower than that of PB-PMN. The in vitro migration of CR-PMN was reduced as compared to that of PB-PMN. Crevicular neutrophils also have a diminished ability to adhere to glass surfaces which may be related to a direct non-cytotoxic effect of gingival fluid component(s) on CR-PMN. In addition, morphologic evidence indicates that specific granules are more depleted than azurophil granules in CR-PMN. Interpretation of studies of neutrophil functions in periodontal diseases must consider the observed differences between normal peripheral blood and crevicular neutrophils.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesMergenhagen, Stephan E. ; Wahl, Sharon M. ; Wahl, Larry M. ; Horton, John E. ; Raisz, Lawrence G.
Oxford, UK : Blackwell Publishing Ltd
Published 1975Staff ViewISSN: 1749-6632Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: Natural Sciences in GeneralType of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesStaff View
ISSN: 0026-7937Topics: Linguistics and Literary StudiesNotes: REVIEWSURL: -
11Articles: DFG German National LicensesStaff View
ISSN: 0009-8981Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: MedicineType of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesStaff View
ISSN: 0040-4020Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Chemistry and PharmacologyType of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesStaff View
ISSN: 0040-4020Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Chemistry and PharmacologyType of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesStaff View
ISSN: 0022-328XSource: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Chemistry and PharmacologyType of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesStaff View
ISSN: 0957-4166Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Chemistry and PharmacologyType of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesPICKERING, BRIAN T. ; BIRKETT, SONIA D. ; GULDENAAR, STEPHAN E. F. ; NICHOLSON, HELEN D. ; WORLEY, RICHARD T. S. ; YAVACHEV, LIBERT
Oxford, UK : Blackwell Publishing Ltd
Published 1989Staff ViewISSN: 1749-6632Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: Natural Sciences in GeneralType of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesWahl, Larry M. ; Olsen, Charles E. ; Wahl, Sharon M. ; McCarthy, James B. ; Sandberg, Ann L. ; Mergenhagen, Stephan E.
Oxford, UK : Blackwell Publishing Ltd
Published 1979Staff ViewISSN: 1749-6632Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: Natural Sciences in GeneralType of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesMönig, Stefan P. ; Baldus, Stephan E. ; Zirbes, Thomas K. ; Schröder, Wolfgang ; Lindemann, David G. ; Dienes, Hans P. ; Hölscher, Arnulf H.
Springer
Published 1999Staff ViewISSN: 1534-4681Keywords: Colon cancer ; Lymph node metastasis ; Lymph node sizeSource: Springer Online Journal Archives 1860-2000Topics: MedicineNotes: Abstract Background: Detection of metastatic lymph nodes in colon cancer is essential for determining stage and adjuvant treatment modalities. Lymph node size has been used as one possible criterion for nodal metastasis. Although enlarged regional lymph nodes are generally interpreted as metastases, few data are available that correlate lymph node size with metastatic infiltration in colon cancer. Methods: In a prospective morphometric study, the regional lymph nodes from 30 colon specimens from consecutive patients with primary colon cancer were analyzed. The lymph nodes were counted and the largest diameter of each lymph node was measured and analyzed for metastatic involvement by histological examination. Results: A total of 698 lymph nodes were present in the 30 specimens examined for this study. A mean number of 23 (range, 19–39) lymph nodes was found in each specimen. Of these nodes, 566 (81%) were tumor-free and 132 (19%) contained metastases. The mean diameter of the lymph nodes free of metastases was 3.9 mm, whereas those infiltrated by metastases averaged 5.9 mm in diameter (P〈 0.0001). Of the tumor-free lymph nodes, 528 (93%) measured 〈 5 mm in diameter, whereas 70 (53%) lymph nodes containing metastases measured 〈 5 mm in diameter. Conclusions: Lymph node size is not a reliable indicator for lymph node metastasis in colon cancer. A careful histological search for small lymph node metastasis in the specimen should be undertaken to avoid false-negative node staging.Type of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesStaff View
ISSN: 1436-5057Source: Springer Online Journal Archives 1860-2000Topics: Computer ScienceDescription / Table of Contents: Abstract A theory of hybrid finite element approximation is developed for a class of shell problems. Though it is applied only to the special case of clamped shallow shells with regular triangularization the results may be of larger interest comparing the predicted convergence rate with the numerical outcome of some applications of the hybrid finite element method. The convergence speed can only be increased by higher degrees of the approximation and the stresses at the edges correspondingly. The use of a so-called rank condition plays a fundamental role in the study. Weak coerciveness of the under lyigg bilinear form for the derivation of hybrid elements is proved by showing the existence of a stationary point.Notes: Zusammenfassung Dieser Beitrag liefert eine Theorie der Finite-Element-Approximation für eine Klasse von Schalenproblemen. Obgleich diese nur für den Fall der eingespannten flachen Schale mit regulärer Triangulierung ausführlich dargestellt wird, sind die Ergebnisse darüberhinaus von Interesse, da die abgeleiteten Konvergenzordnungen das Verhalten numerischer Näherungslösungen aus anderen Anwendungen der hybriden Finite-Element-Methode erklären helfen. Die Konvergenzgeschwindigkeit kann nur verbessert werden durch gleichzeitige Erhöhung der Ansatzgrade für die Verschiebungen im Elementinnern und für die Spannungen auf den Rändern. Die Einhaltung einer sogenannten Rangbedingung hat zentrale Bedeutung. Die schwache Koerzitivität der für die Ableitung hybrider Elemente verwendeten Bilinearform ist durch den Nachweis der Existenz eines stationären Werts gesichert.Type of Medium: Electronic ResourceURL: -
20Articles: DFG German National LicensesStaff View
ISSN: 1436-5057Keywords: 65N55 ; 65N38 ; Boundary integral equations ; domain decomposition ; Schwarz methodsSource: Springer Online Journal Archives 1860-2000Topics: Computer ScienceDescription / Table of Contents: Zusammenfassung Es werden zwei Gebietszerlegungsalgorithmen für die numerische Behandlung von Randintegralgleichungen der ersten Art untersucht. Die Verfahren beruhen auf derh-Version der Galerkinmethode für Randelemente, auf die die multiplikative und die additive Schwarz-Methode angewandt werden. Für zweidimensionale Probleme wird gezeigt, daß die Konvergenzraten beider Methoden unabhängig von der Anzahl der Unbekannten sind. Numerische Resultate für einfache zweidimensionale und dreidimensionale Modellprobleme, die von der Laplace-Gleichung mit Dirichlet oder Neumann-Randbedingungen stammen, werden diskutiert. Eine Gebietszerlegungsstrategie für den Fall vieler Teilgebiete wird anhand eines dreidimensionalen Schirmproblems demonstriert.Notes: Abstract This paper investigates two domain decomposition algorithms for the numerical solution of boundary integral equations of the first kind. The schemes are based on theh-type boundary element Galerkin method to which the multiplicative and the additive Schwarz methods are applied. As for twodimensional problems, the rates of convergence of both methods are shown to be independent of the number of unknowns. Numerical results for standard model problems arising from Laplaces' equation with Dirichlet or Neumann boundary conditions in both two and three dimensions are discussed. A multidomain decomposition strategy is indicated by means of a screen problem in three dimensions, so as to obtain satisfactory experimental convergence rates.Type of Medium: Electronic ResourceURL: