Search Results - (Author, Cooperation:M. H. Crawford)
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1Latest Papers from Table of Contents or Articles in PressM. Raghavan ; M. DeGiorgio ; A. Albrechtsen ; I. Moltke ; P. Skoglund ; T. S. Korneliussen ; B. Gronnow ; M. Appelt ; H. C. Gullov ; T. M. Friesen ; W. Fitzhugh ; H. Malmstrom ; S. Rasmussen ; J. Olsen ; L. Melchior ; B. T. Fuller ; S. M. Fahrni ; T. Stafford, Jr. ; V. Grimes ; M. A. Renouf ; J. Cybulski ; N. Lynnerup ; M. M. Lahr ; K. Britton ; R. Knecht ; J. Arneborg ; M. Metspalu ; O. E. Cornejo ; A. S. Malaspinas ; Y. Wang ; M. Rasmussen ; V. Raghavan ; T. V. Hansen ; E. Khusnutdinova ; T. Pierre ; K. Dneprovsky ; C. Andreasen ; H. Lange ; M. G. Hayes ; J. Coltrain ; V. A. Spitsyn ; A. Gotherstrom ; L. Orlando ; T. Kivisild ; R. Villems ; M. H. Crawford ; F. C. Nielsen ; J. Dissing ; J. Heinemeier ; M. Meldgaard ; C. Bustamante ; D. H. O'Rourke ; M. Jakobsson ; M. T. Gilbert ; R. Nielsen ; E. Willerslev
American Association for the Advancement of Science (AAAS)
Published 2014Staff ViewPublication Date: 2014-08-30Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsKeywords: Alaska/ethnology ; Arctic Regions/ethnology ; Base Sequence ; Bone and Bones ; Canada/ethnology ; DNA, Mitochondrial/genetics ; Genome, Human/*genetics ; Greenland/ethnology ; Hair ; History, Ancient ; *Human Migration ; Humans ; Inuits/ethnology/*genetics/history ; Molecular Sequence Data ; Siberia/ethnology ; Survivors/history ; ToothPublished by: -
2Articles: DFG German National LicensesDiffusion, release, and uptake of hydrogen in magnesium-doped gallium nitride: Theory and experimentMyers, S. M. ; Wright, A. F. ; Petersen, G. A. ; Wampler, W. R. ; Seager, C. H. ; Crawford, M. H. ; Han, J.
[S.l.] : American Institute of Physics (AIP)
Published 2001Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: The diffusion and release of H and its uptake from the gas phase are modeled for Mg-doped, wurtzite GaN using formation energies and vibration frequencies from the density-function theory. Comparison is made with rates of deuterium release and uptake measured by nuclear-reaction analysis of deuterium concentration. Good agreement is found when account is taken of a surface permeation barrier. © 2001 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
3Articles: DFG German National LicensesMyers, S. M. ; Wright, A. F. ; Petersen, G. A. ; Seager, C. H. ; Wampler, W. R. ; Crawford, M. H. ; Han, J.
[S.l.] : American Institute of Physics (AIP)
Published 2000Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Formation energies and vibration frequencies for H in wurtzite GaN were calculated from density-functional theory and used to predict equilibrium state occupancies and solid solubilities at elevated temperatures for p-type, intrinsic, and n-type material. The solubility of deuterium (D) was measured in p-type, Mg-doped GaN at 600, 700, and 800 °C as a function of D2 pressure and compared with theory. Agreement was obtained by reducing the H formation energies 0.22 eV from ab initio theoretical values. The predicted stretch-mode frequency for H bound to the Mg acceptor lies 5% above an observed infrared absorption attributed to this complex. More limited solubility measurements were carried out for nominally undoped material rendered n-type by donors provisionally identified as O impurities, and results agree well with theory after the aforementioned adjustment of formation energies. It is concluded that currently recognized H states and physical processes can account for the equilibrium, elevated-temperature behavior of H examined in this work. © 2000 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesHan, J. ; Ng, T.-B. ; Biefeld, R. M. ; Crawford, M. H. ; Follstaedt, D. M.
Woodbury, NY : American Institute of Physics (AIP)
Published 1997Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: In situ optical reflectance transients reveal that the morphology evolution of the initial low-temperature buffer layer strongly influences the structural and electrical quality of the high-temperature GaN films. Moreover, the morphology evolution of that buffer layer, specifically evolution of the spatial and orientational distributions of the nuclei, is strongly affected by H2. The growth conditions for which surface smoothness is maintained throughout the two-step growth do not necessarily produce the best quality final GaN films; instead, there may be an optimal roughness and incubation period en route to the best quality final films.Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesKurtz, S. R. ; Biefeld, R. M. ; Allerman, A. A. ; Howard, A. J. ; Crawford, M. H. ; Pelczynski, M. W.
Woodbury, NY : American Institute of Physics (AIP)
Published 1996Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: A pseudomorphic, compressively strained InAs0.94Sb0.06 multiple quantum well injection laser, emitting in the 3.5–3.6 μm range is reported. The device was grown by metalorganic chemical vapor deposition, and x-ray and optical characterization indicate that the active region has a very low dislocation density. In pulsed mode, the laser operated at 135 K and displayed a characteristic temperature of 33 K, equaling the highest value reported for molecular-beam epitaxy grown, InAsSb/InAlAsSb active region lasers of comparable wavelength. Factors limiting the performance of these lasers are discussed. © 1996 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesLee, S. R. ; Wright, A. F. ; Crawford, M. H. ; Petersen, G. A. ; Han, J. ; Biefeld, R. M.
Woodbury, NY : American Institute of Physics (AIP)
Published 1999Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: The band gap of AlxGa1−xN is measured for the composition range 0≤x〈0.45; the resulting bowing parameter, b=+0.69 eV, is compared to 20 previous works. A correlation is found between the measured band gaps and the methods used for epitaxial growth of the AlxGa1−xN: directly nucleated or buffered growths of AlxGa1−xN initiated on sapphire at temperatures T〉800 °C usually lead to stronger apparent bowing (b〉+1.3 eV); while growths initiated using low-temperature buffers on sapphire, followed by high-temperature growth, lead to weaker bowing (b〈+1.3 eV). Extant data suggest that the intrinsic band-gap bowing parameter for AlGaN alloys is b=+0.62(±0.45) eV. © 1999 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesHan, J. ; Crawford, M. H. ; Shul, R. J. ; Figiel, J. J. ; Banas, M. ; Zhang, L.
Woodbury, NY : American Institute of Physics (AIP)
Published 1998Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: We report on the growth and characterization of ultraviolet GaN quantum well light emitting diodes. The room-temperature electroluminescence emission was peaked at 353.6 nm with a narrow linewidth of 5.8 nm. In the simple planar devices, without any efforts to improve light extraction efficiency, an output power of 13 μW at 20 mA was measured, limited in the present design by absorption in the GaN cap layer and buffer layer. Pulsed electroluminescence data demonstrate that the output power does not saturate up to current densities approaching 9 kA/cm2. © 1998 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesHoward, A. J. ; Blum, O. ; Chui, H. ; Baca, A. G. ; Crawford, M. H.
Woodbury, NY : American Institute of Physics (AIP)
Published 1996Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: An epitaxial layer thickness measurement technique has been developed using cross-sectional atomic force microscopy (XSAFM). Cleaved and etched epitaxial heterostructures of Al0.5Ga0.5As/GaAs have been analyzed using this technique. XSAFM analysis of a 20.5 period structure of 300-A(ring)-thick Al0.5Ga0.5As/GaAs layers agreed to within 2% of x-ray diffraction data. XSAFM analysis of a structure consisting of GaAs wells ranging from ∼15 to 600 A(ring) with 300 A(ring) Al0.5Ga0.5As barriers was also performed. The XSAFM measured well thicknesses agreed quite well with photoluminescence (PL) measurements taken at 4 K. XSAFM can thus serve as a rapid alternative to conventional thickness measurement techniques such as SEM and TEM. © 1996 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesSchanfield, M. S. ; Crawford, M. H. ; Dossetor, J. B. ; Gershowitz, H.
Baltimore : Periodicals Archive Online (PAO)
Published 1990Staff ViewISSN: 0018-7143Topics: BiologyURL: -
10Articles: DFG German National LicensesStaff View
ISSN: 0018-7143Topics: BiologyNotes: EditorialURL: -
11Articles: DFG German National LicensesMcComb, J. ; Blagitko, N. ; Comuzzie, A. G. ; Schanfield, M. S. ; Sukernik, R. I. ; Leonard, W. R. ; Crawford, M. H.
Baltimore : Periodicals Archive Online (PAO)
Published 1995Staff ViewISSN: 0018-7143Topics: BiologyURL: -
12Articles: DFG German National LicensesSirajuddin, S. M. ; Duggirala, R. ; Crawford, M. H.
Baltimore : Periodicals Archive Online (PAO)
Published 1994Staff ViewISSN: 0018-7143Topics: BiologyURL: -
13Articles: DFG German National LicensesStaff View
ISSN: 0018-7143Topics: BiologyNotes: Special Issue on Foundations of Anthropological GeneticsURL: -
14Articles: DFG German National LicensesStevenson, J. C. ; Everson, P. M. ; Crawford, M. H.
Baltimore : Periodicals Archive Online (PAO)
Published 1989Staff ViewISSN: 0018-7143Topics: BiologyURL: -
15Articles: DFG German National LicensesKoertvelyessy, T. ; Crawford, M. H. ; Pap, M. ; Szilagyi, K.
Baltimore : Periodicals Archive Online (PAO)
Published 1990Staff ViewISSN: 0018-7143Topics: BiologyURL: -
16Articles: DFG German National LicensesCrawford, M. H. ; Dykes, D. D. ; Polesky, H. F.
Baltimore : Periodicals Archive Online (PAO)
Published 1989Staff ViewISSN: 0018-7143Topics: BiologyURL: -
17Articles: DFG German National LicensesStaff View
ISSN: 0018-7143Topics: BiologyURL: -
18Articles: DFG German National LicensesKoertvelyessy, T. A. ; Crawford, M. H. ; Hutchinson, J.
Baltimore : Periodicals Archive Online (PAO)
Published 1982Staff ViewISSN: 0018-7143Topics: BiologyURL: -
19Articles: DFG German National LicensesNovoradovsky, A. G. ; Spitsyn, V. A. ; Duggirala, R. ; Crawford, M. H.
Baltimore : Periodicals Archive Online (PAO)
Published 1993Staff ViewISSN: 0018-7143Topics: BiologyURL: -
20Articles: DFG German National LicensesMungall, D. R. ; Ludden, T. M. ; Marshall, J. ; Hawkins, D. W. ; Talbert, R. L. ; Crawford, M. H.
Springer
Published 1985Staff ViewISSN: 1573-8744Keywords: warfarin kinetics ; population analysis ; anticoagulants ; age and kineticsSource: Springer Online Journal Archives 1860-2000Topics: Chemistry and PharmacologyNotes: Abstract The population pharmacokinetics of racemic warfarin was evaluated using 613 measured warfarin plasma concentrations from 32 adult hospitalized patients and 131 adult outpatients. Warfarin concentrations were measured in duplicate using a high-performance liquid chromatographic procedure. The pharmacokinetic model used was a one-compartment open model with first-order absorption (absorption rate constant set equal to 47 day−1) and first-order elimination. The extent of availability was assumed to be one. A linear regression model was used to evaluate the influence of various demographic factors on warfarin oral clearance. Age appeared to be an important determinant of warfarin clearance in this adult population. There was about a 1%/year decrease in oral clearance over the age range of 20–70 years. Smoking appeared to result in a 10% increase in warfarin clearance, while coadministration of the inducers phenytoin or phenobarbital yielded about a 30% increase in clearance. This study has yielded a predictive model that, when combined with appropriate pharmacological response data, may be useful in the design and adjustment of warfarin regimens.Type of Medium: Electronic ResourceURL: