Search Results - (Author, Cooperation:D. R. Young)
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1Latest Papers from Table of Contents or Articles in PressM. Nicholl ; S. J. Smartt ; A. Jerkstrand ; C. Inserra ; M. McCrum ; R. Kotak ; M. Fraser ; D. Wright ; T. W. Chen ; K. Smith ; D. R. Young ; S. A. Sim ; S. Valenti ; D. A. Howell ; F. Bresolin ; R. P. Kudritzki ; J. L. Tonry ; M. E. Huber ; A. Rest ; A. Pastorello ; L. Tomasella ; E. Cappellaro ; S. Benetti ; S. Mattila ; E. Kankare ; T. Kangas ; G. Leloudas ; J. Sollerman ; F. Taddia ; E. Berger ; R. Chornock ; G. Narayan ; C. W. Stubbs ; R. J. Foley ; R. Lunnan ; A. Soderberg ; N. Sanders ; D. Milisavljevic ; R. Margutti ; R. P. Kirshner ; N. Elias-Rosa ; A. Morales-Garoffolo ; S. Taubenberger ; M. T. Botticella ; S. Gezari ; Y. Urata ; S. Rodney ; A. G. Riess ; D. Scolnic ; W. M. Wood-Vasey ; W. S. Burgett ; K. Chambers ; H. A. Flewelling ; E. A. Magnier ; N. Kaiser ; N. Metcalfe ; J. Morgan ; P. A. Price ; W. Sweeney ; C. Waters
Nature Publishing Group (NPG)
Published 2013Staff ViewPublication Date: 2013-10-18Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsPublished by: -
2Articles: DFG German National LicensesHofmann, K. ; Rubloff, G. W. ; Young, D. R.
[S.l.] : American Institute of Physics (AIP)
Published 1987Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: The influence of annealing in vacuum and in controlled low-pressure oxygen ambient on breakdown characteristics of thin (∼500 A(ring)) SiO2 films on Si (100) has been studied under ultrahigh vacuum conditions for temperatures 750–900 °C and controlled O2 partial pressures in the range 10−6–5×10−2 Torr. Dark current-voltage measurements on Al-gate capacitors show that vacuum annealing causes low-field self-healing breakdown by the formation of local defects in the oxide. This degradation of breakdown characteristics is suppressed by the presence of sufficient O2 in the annealing ambient, such that the O2 partial pressure must exceed the SiO equilibrium partial pressure by a factor of ∼100×. This behavior suggests that low-field breakdown is a consequence of oxide decomposition (Si+SiO2→2SiO↑) at defects in the oxide, which is suppressed by reoxidation of the volatile SiO reaction product.Type of Medium: Electronic ResourceURL: -
3Articles: DFG German National LicensesStaff View
ISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: We report depth profiles of the hydrogen concentrations in metal-oxide-semiconductor structures measured using the nuclear reaction profiling technique with a 6.4-MeV 15N beam. In both conventionally grown and ultra-dry thermal oxide samples with aluminum or gold gate metal, a peak of hydrogen concentration is observed at the metal/SiO2 interface. The amount of hydrogen at this interface varied from sample to sample in the range 2–6×1015 H/cm2, which was at least 20 times as much as in the SiO2 layers. By continued irradiation with the measuring beam, most of this hydrogen was detrapped from the metal/SiO2 interface and diffused into the SiO2. The detrapping occurred much more rapidly in samples made with Al metallization than in Au gate or unmetallized samples. The data can be fitted by a model in which hydrogen is detrapped from the metal/SiO2 interface by the beam, then diffuses into the SiO2. Redistribution of hydrogen was found to continue until it was uniformly distributed throughout the SiO2, with a residual peak of strongly trapped hydrogen remaining at the metal/SiO2 boundary. At the same time the concentration of hydrogen in the SiO2 increased from an initial low level to about 4×1020 cm−3, depending on the amount of hydrogen initially at the Al/SiO2 interface.Type of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesHofmann, K. ; Young, D. R. ; Rubloff, G. W.
[S.l.] : American Institute of Physics (AIP)
Published 1987Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: The generation of hole traps in thermal SiO2 films on Si(100) has been characterized as a function of O2 partial pressure in the annealing ambient in order to address the chemistry associated with the hole traps. The annealing treatments were carried out in ultrahigh vacuum (base pressure∼5×10−9 Torr) without and with the presence of an intentional (controlled) partial pressure of O2 in the range 10−6–5×10−2 Torr. Hole trapping was characterized using the avalanche injection technique. Annealing in vacuum results in an increased hole trapping rate similar to that observed for high-temperature (T〉900 °C) furnace annealing in N2. The hole trapping is reduced upon annealing in O2 containing ambients if the O2 partial pressure exceeds the SiO vapor pressure by at least one order of magnitude. Thus, the presence of sufficient O2 in the postoxidation annealing process suppresses hole trapping. These results appear analogous to the reduction in low-field breakdown when O2 is present, as recently reported. In both cases, it is likely that the O2 serves to reoxidize a defect related SiO product which is generated by Si-SiO2 reaction at the interface.Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesStaff View
ISSN: 1468-2338Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: EconomicsNotes: An analysis of the assumptions underlying the traditional approaches to training demonstrates their inadequacy when it comes to the development of training in an industrial relations context. By taking a broader approach, however, suitable training strategies and methods can be developed.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesStaff View
ISSN: 1747-6593Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: Energy, Environment Protection, Nuclear Power EngineeringNotes: The River Sheaf Comprehensive Flood-Alleviation Scheme is a flood-defence scheme promoted by the Yorkshire Region of the National Rivers Authority. The scheme will improve 5.2 km of main river from a 1-in-5 year standard to a 1-in-50 standard at an overall cost of £3.1 million over the next four years. The hydrological, hydraulic and benefit/cost analyses have been carried out by the National Rivers Authority. Balfour Maunsell were commissioned to carry out the detailed structural design, prepare and administer contracts and supervise construction. The paper covers the preliminary design work and the detailed design of Phase I of the scheme.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] The short-lived (253 days) 110mAg was determined in 1964 (ref. 2); on the other hand, a recently installed two-dimensional y-ray spectrometer of a type developed by the Hanford group3 was used for measuring 108mAg. Table 1 lists the activities of 108mAg found in samples of squid, mussel, lobster, ...Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] First, we did not mean to imply that the 108mAg and 110mAg observed in the Pacific marine organisms was actually produced primarily by thermal neutron activation of stable silver; only that the assumption of an initial 110mAg/108mAg activity ratio value of 162 yielded apparently reasonable dates of ...Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesStaff View
ISSN: 1432-1890Keywords: Key words Barrier island ; Actinorhizal ; Vesicular-arbuscular mycorrhizae (VAM) ; Myrica cerifera ; Shrub thicketSource: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Abstract A combined laboratory and field study examined the potential for a symbiotic association between the actinorhizal shrub Myrica cerifera and vesicular arbuscular mycorrhizal (VAM) fungi on a Virginia barrier island. M. cerifera seedlings and two test species, Zea mays and Strophostyles umbellata, were grown in an environmental chamber on soils collected from four sites differing in soil age (〈5 to over 130 years), salinity (1–35 μg/g total soil chloride), and edaphic characteristics. Seedling root infection was significantly lower for all three species in the youngest soils from the beach where salinity was highest. Stained M. cerifera roots revealed all the components for a functional VAM association; however, there were significantly fewer arbuscules and vesicles relative to the test species. Among field-collected M. cerifera, infection was not detected in mature shrubs from the bay side of the island, where M. cerifera thickets were in a state of degeneration. Infection was highest in soils from the young, developing thickets, and in the most stable thickets of the island interior. Despite the dynamic nature of the barrier island environment, VAM associations with M. cerifera appear to be present, especially in seedlings and developing shrub thickets.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] MARINE organisms collected along the California Coast in 1963 and examined1 for 54Mn and 65Zn by ordinary ?-spectrometry often appeared to contain in addition small traces of 60Co. As cobalt is believed to be essential to normal growth for many -organisms and 60Co is a radio-label which decays ...Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesFOLSOM, T. R. ; YOUNG, D. R. ; JOHNSON, J. N. ; PILLAI, K. C.
[s.l.] : Nature Publishing Group
Published 1963Staff ViewISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] IT has been estimated1 that 855 curies of zinc-65 enter the Pacific each day at the mouth of the Columbia River along with other nuclides arising from activation of cooling water constituents at Hanford. Osterberg2'3 and others1 have reported extensively on concentrations of zinc-65 in marine ...Type of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesStaff View
ISSN: 1432-0827Keywords: Bone ; Bending rigidity ; Disuse atrophySource: Springer Online Journal Archives 1860-2000Topics: BiologyMedicinePhysicsNotes: Summary The in vivo bending rigidity and bone mineral content of monkey ulnae and tibiae were measured. Bending rigidity in the anteroposterior plane was measured by an impedance probe technique. Forced vibrations of the bones were induced with an electromechanical shaker, and force and velocity at the driving point were determined. The responses over the range of 100–250 Hz were utilized to compute the bending rigidity. Bone mineral content in the cross section was determined by a photon absorption technique. Seventeen male monkeys (Macaca nemestrina) weighing 6–14 kg were evaluated. Repeatability of the rigidity measures was 4%. Bone mineral content was measured with a precision of 3.5%. Bending rigidity was correlated with the mineral content of the cross section,r=0.899. Two monkeys were evaluated during prolonged hypodynamic restraint. Restraint produced regional losses of bone most obviously in the proximal tibia. Local bone mineral content declines 17 to 24% and the average bending rigidity declines 12 to 22%. Changes in bones leading to a reduction in mineral content and stiffness are discussed.Type of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesStaff View
ISSN: 1432-0827Keywords: Immobilization ; Bone strength ; Resorption ; RecoverySource: Springer Online Journal Archives 1860-2000Topics: BiologyMedicinePhysicsNotes: Summary We studied the mechanical properties and structural changes in the monkey tibia with disuse osteoporosis and during subsequent recovery. Bone bending stiffness was evaluated in relationship to microscopic changes in cortical bone and Norland bone mineral analysis. Restraint in the semireclined position produced regional losses of bone most obviously in the anterior-proximal tibiae. Following 6 months of restraint, the greatest losses of bone mineral in the proximal tibiae ranged from 23% to 31%; the largest changes in bone stiffness ranged from 36% to 40%. Approximately 8 ½ months of recovery were required for restoration of normal bending properties. However, even after 15 months of recovery, bone mineral content did not necessarily return to normal levels. Histologically, resorption cavities in cortical bone were seen within 1 month of restraint; by 2 ½ months of restraint there were large resorption cavities subperiosteally, endosteally, and intracortically. After 15 months of recovery, the cortex consisted mainly of first-generation haversian systems. After 40 months, the cortex appeared normal with numerous secondary and tertiary generations of haversian systems.Type of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesStaff View
ISSN: 1432-0827Keywords: Immobilization ; Metabolic alkalosis ; Renal acid excretionSource: Springer Online Journal Archives 1860-2000Topics: BiologyMedicinePhysicsNotes: Summary We studied the systemic and renal acid—base response of monkeys during ten weeks of immobilization. By three weeks of immobilization, arterial pH and bicarbonate concentrations were elevated (chronic metabolic alkalosis). Net urinary acid excretion increased in immobilized animals. Urinary bicarbonate excretion decreased during the first three weeks of immobilization, and then returned to control levels. Sustained increases in urinary ammonium excretion were seen throughout the time duration of immobilization. Neither potassium depletion nor hypokalemia was observed. Most parameters returned promptly to the normal range during the first week of recovery. Factors tentatively associated with changes in acid—base status of monkeys include contraction of extracellular fluid volume, retention of bicarbonate, increased acid excretion, and possible participation of extrarenal buffers.Type of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesStaff View
ISSN: 1432-0827Keywords: Bone ; Osteopenia ; Noninvasive monitoringSource: Springer Online Journal Archives 1860-2000Topics: BiologyMedicinePhysicsNotes: Summary Radiological techniques were utilized for monitoring progressive changes in compact bone in the tibia of monkeys during experimentally induced osteopenia. Bone mass loss in the tibia during restraint was evaluated from radiographs, from bone mineral analysis, and from images reconstructed from gamma ray computerized tomography. The losses during 6 months of restraint tended to occur predominantly in the proximal tibia and were characterized by subperiosteal bone loss, intracortical striations, and scalloped endosteal surfaces. Bone mineral content in the cross section of the tibia declined 17–21%. Tomography demonstrated endosteal widening and reduced mineral content per unit of thickness of cortical bone. In 6 months of recovery, the mineral content of the proximal tibia remained depressed. Effects of the dynamic environment on local-regional changes in various skeletal areas are discussed.Type of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesStaff View
ISSN: 1432-1939Source: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Summary The temperature and water relations of the herbaceous, understory, congeners Arnica cordifolia and Arnica latifolia were evaluated in relation to the sunfleck dynamics of their respective microhabitats. Arnica cordifolia microhabitats had more frequent, longer, and more intense sunflecks than those of A. latifolia which led to higher leaf temperatures (31°C versus 15°C) and transpirational fluxes (65 μg cm-2 s-1 versus 16 μg cm-2 s-1). Stomatal closure did not occur in response to high leaf temperatures and low stem water potentials during natural sunfleck exposures, even though plants were observed to wilt during midday, especially A. cordifolia. Experimentally, an artificial midday sunfleck of about 165 min caused plants of A. cordifolia not to regain turgor after 8 h in shade compared to a sunfleck duration of about 90 min for plants of A. latifolia. However, these sunfleck intervals occurred naturally only during the early morning and late afternoon when solar intensities were minimal. Also, A. cordifolia populations had over twice as many plants that were sunlit (〉40% of total) compared with A. latifolia (〈20% of total) at any particular time during a day. The small-scale distribution of both species appears tightly coupled to the sunfleck dynamics of their respective microhabitats due to the lack of stomatal action which would reduce transpiration and improve plant water status under sunlit conditions.Type of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesSmith, W. K. ; Young, D. R. ; Carter, G. A. ; Hadley, J. L. ; McNaughton, G. M.
Springer
Published 1984Staff ViewISSN: 1432-1939Source: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Summary Environmental and water relations parameters during fall were monitored for six conifer tree species common to the central Rocky Mountains growing naturally at the same location (Pinus contorta, Pinus ponderosa, Pinus flexilus, Pseudotsuga menziesii, Abies lasiocarpa, Picea engelmannii). Subsequent to what appeared to be the beginning of seasonal stomatal closure, leaf conductance to water vapor declined sharply following the onset of freezing air temperatures at night. A coincident rapid decline in morning xylem pressure potentials (ψp) also occurred which resulted in values that were considerably below afternoon ψp. Continuing decreases in maximum leaf conductance during the day were highly correlated with corresponding decreases in minimum nocturnal air temperatures of the preceding night. By mid-December, morning ψp returned to values very near afternoon ψp and were only slightly lower than before the onset of subfreezing nights. A preliminary model is proposed which interprets the qualitative interaction between air and soil temperatures, soil and plant water potentials, and leaf conductance during seasonal stomatal closure in fall.Type of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesStaff View
ISSN: 1432-1939Source: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Summary The relationships between volumetric soil water content (ϕ), in situ soil water potential (Ίsoil) and predawn xylem pressure potential (Ίpredawn) were quantified in four contrasting lodgepole pine ecosystems in Wyoming, USA. On three of the sites, changes in Ίsoil correlated closely with Ίpredawn, but on a porous soil derived from coarse granitic parent material, Ίpredawn declines occurred much sooner than corresponding declines in Ίsoil, possibly because of local depletion of rhizosphere moisture and low molecular diffusivity of water in that soil. Exptrapolation of laboratory-derived characteristic curves for soil moisture to field conditions yielded different relationships between ϕ and Ίsoil than curves derived from in situ measurements, probably because of disruption of soil structure and porosity during sample collection and handling in laboratory studies. Although a close correlation between ϕ and Ίpredawn was observed, future efforts at modelling the soil-plant-atmosphere continuum should be directed towards a more detailed understanding of the complex relationships between Ίsoil at varying depths and plant water stress.Type of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesStaff View
ISSN: 0095-9898Keywords: Life and Medical Sciences ; Cell & Developmental BiologySource: Wiley InterScience Backfile Collection 1832-2000Topics: BiologyMedicineAdditional Material: 3 Tab.Type of Medium: Electronic ResourceURL: