4,467 research outputs found
Estimating stratospheric temperature trends using satellite microwave radiances
The objective was to evaluate and intercompare stratospheric temperatures using Microwave Sounding Unit (MSU) data as a basis data set. The MSU, aboard the NOAA polar orbiter satellite series, provides twice daily global coverage over a layer (50-150 mb) at approximately a (170km)(exp 2) resolution. Conventional data sets will be compared to the satellite data in the lower stratosphere in order to assess their quality for trend computations
Interview Feature: Interview with Frank N. Kelley, Dean, College of Polymer Science and Polymer Engineering, and Professor of Polymer Science, June 1996
Author Institution: Department of Educational Foundations and Leadership, The University of Akro
Evidence for a Hard Ionizing Spectrum from a z=6.11 Stellar Population
We present the Magellan/FIRE detection of highly-ionized CIV 1550 and OIII]
1666 in a deep infrared spectrum of the z=6.11 gravitationally lensed low-mass
galaxy RXC J2248.7-4431-ID3, which has previously-known Lyman-alpha. No
corresponding emission is detected at the expected location of HeII 1640. The
upper limit on HeII paired with detection of OIII] and CIV constrains possible
ionization scenarios. Production of CIV and OIII] requires ionizing photons of
2.5-3.5 Ryd, but once in that state their multiplet emission is powered by
collisional excitation at lower energies (~0.5 Ryd). As a pure recombination
line, HeII emission is powered by 4 Ryd ionizing photons. The data therefore
require a spectrum with significant power at 3.5 Ryd but a rapid drop toward
4.0 Ryd. This hard spectrum with a steep drop is characteristic of
low-metallicity stellar populations, and less consistent with soft AGN
excitation, which features more 4 Ryd photons and hence higher HeII flux. The
conclusions based on ratios of metal line detections to Helium non-detection
are strengthened if the gas metallicity is low. RXJ2248-ID3 adds to the growing
handful of reionization-era galaxies with UV emission line ratios distinct from
the general z=2-3 population, in a way that suggests hard ionizing spectra that
do not necessarily originate in AGN.Comment: 7 pages, 4 figures, 1 table. Accepted for publication to ApJ
Efficacy of non-lead ammunition for culling elk at Theodore Roosevelt National Park
During 2010 to 2013, park staff and public volunteers culled 983 elk (Cervus elaphus) from Theodore Roosevelt National Park (United States) utilizing non-lead rifle ammunition as part of a sanctioned herd management operation. Because there is little empirical evidence available on the performance of non-lead ammunition, staff recorded information on tools and techniques relevant to the scenarios under which elk were culled and the outcome of each engagement. We also conducted a fi ring range experiment to evaluate the precision of nonlead ammunition used in park fi rearms. Specific objectives were to identify program factors predicting efficient destruction of elk with non-lead ammunition and to evaluate the precision of non-lead ammunition in National Park Service (NPS) fi rearms to facilitate accurate shot placement. To address these objectives, we conducted multivariate ordinal regression analyses of 13 variables, including bullet type, marksman type, shot distance, initial shot impact location, number of shots fi red, and need for a killing shot, as predictors of distance traveled by elk after being shot. Among 921 elk removals evaluated, mean shot distance was 182 meters, and the median and mode of distance traveled were 46 m and 0 m, respectively. Multivariate analyses revealed that shots to the head and neck were most effective, followed by those striking the shoulder and chest. Heavier bullets should be used whenever practical. Mean group size for non-lead ammunition fi red through NPS fi rearms was 50 mm at 91 m, with minimum and maximum group sizes of 18.8 and 98.6 mm, respectively. We found that non-lead ammunition provided the necessary precision for accurate shot placement in spot and stalk hunting conditions and that these bullets typically accomplished instantaneous or near-instantaneous incapacitation of elk whenever vital areas of the body were impacted. We conclude that non-lead bullets are effective for wildlife management and hunting scenarios
Uniformity of Airflow in Automotive Air Filter Test Housings and Its Effects on the Efficiency of Fibrous Filters
School of Mechanical and Aerospace Engineerin
Color and pigment polymorphisms of northern leopard frogs on a prairie landscape
Variation allows populations to adapt to changing conditions. As human activities continue to alter environments and evolutionary processes, it becomes increasingly important to conserve standing genetic variation. Despite technical advances in population genetics, it is still useful to have inexpensive methods of detecting and monitoring genetic variation, particularly in traits that potentially influence fitness. In the Northern Leopard Frog, Lithobates pipiens (= Rana pipiens), genetically determined color (green [dominant: G] or brown [recessive: g]) and two pigment pattern polymorphisms (Burnsi/spotless [B] or spotted [b]; Kandiyohi/mottled [K] or non-mottled[k]) are hypothesized to have adaptive benefits. We assessed spatiotemporal patterns of these polymorphisms during two time periods in one of the largest remaining grasslands in North America. The frequency of the dominant green phenotype remained consistent from the early-to-late 2000s; however, we observed Kandiyohi phenotypes more frequently during 2001–2002 compared to 2009–2010. By contrast, we observed dominant Burnsi phenotypes more frequently in the latter time period. Although not statistically significant, we observed green phenotypes more frequently in areas with less water on the landscape and in locations closer to tree cover. Burnsi phenotypes were more common in wetlands that did not dry out and Kandiyohi phenotypes were more common in wetlands with aquatic vegetation, although not significantly. No pigment polymorphism was associated with body size. We found no indication of spatial structure, suggesting ample gene flow. The correlations were generally weak, but some were consistent with hypotheses of adaptive benefits. This genetically determined phenotypic variation could be important under changing climactic conditions or if land uses change
Social-structural contexts of needle and syringe sharing behaviours of HIV-positive injecting drug users in Manipur, India: a mixed methods investigation
<p>Abstract</p> <p>Background</p> <p>Few investigations have assessed risk behaviours and social-structural contexts of risk among injecting drug users (IDUs) in Northeast India, where injecting drug use is the major route of HIV transmission. Investigations of risk environments are needed to inform development of effective risk reduction interventions.</p> <p>Methods</p> <p>This mixed methods study of HIV-positive IDUs in Manipur included a structured survey (n = 75), two focus groups (n = 17), seven in-depth interviews, and two key informant interviews.</p> <p>Results</p> <p>One-third of survey participants reported having shared a needle/syringe in the past 30 days; among these, all the men and about one-third of the women did so with persons of unknown HIV serostatus. A variety of social-structural contextual factors influenced individual risk behaviours: barriers to carrying sterile needles/syringes due to fear of harassment by police and "anti-drug" organizations; lack of sterile needles/syringes in drug dealers' locales; limited access to pharmacy-sold needles/syringes; inadequate coverage by needle and syringe programmes (NSPs); non-availability of sterile needles/syringes in prisons; and withdrawal symptoms superseding concern for health. Some HIV-positive IDUs who shared needles/syringes reported adopting risk reduction strategies: being the 'last receiver' of needles/syringes and not a 'giver;' sharing only with other IDUs they knew to be HIV-positive; and, when a 'giver,' asking other IDUs to wash used needles/syringes with bleach before using.</p> <p>Conclusions</p> <p>Effective HIV prevention and care programmes for IDUs in Northeast India may hinge on several enabling contexts: supportive government policy on harm reduction programmes, including in prisons; an end to harassment by the police, army, and anti-drug groups, with education of these entities regarding harm reduction, creation of partnerships with the public health sector, and accountability to government policies that protect IDUs' human rights; adequate and sustained funding for NSPs to cover all IDU populations, including prisoners; and non-discriminatory access by IDUs to affordable needles/syringes in pharmacies.</p
An experimental and theoretical study of transient negative ions in Mg, Zn, Cd and Hg
A range of experimental and theoretical techniques have been applied to the study of transient negative ions (resonances) formed in electron scattering from the Group II metals Mg, Zn, Cd, and Hg at incident electron energies below the first ionization potential. A wealth of resonance structures have been observed and from the experimental observations and theoretical information, classifications are proposed for some of these negative ion states
Replica-Based Crack Inspection
Surface replication has been proposed as a method for crack detection in space shuttle main engine flowliner slots. The results of a feasibility study show that examination of surface replicas with a scanning electron microscope can result in the detection of cracks as small as 0.005 inch, and surface flaws as small as 0.001 inch, for the flowliner material
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1,2-diaminocyclohexane-platinum complexes with antitumor activity
The present invention comprises a water-soluble square-planar cis-platinum(II) four-coordinate complex having the formula: EQU trans-R,R-DACH Pt(II) X.sub.2 or EQU trans-R,R-DACH Pt(II) Y wherein X is a monovalvent cation, two of which are present, selected from the group consisting of cyclopropanecarboxylato, shikimato, saccharatolactone, galacturonato and N,N-dimethyglycinato; wherein Y is a divalent cation selected from the group consisting of citraconato, 1,1-cyclobutanedicarboxylato, 1,1-cyclopropanedicarboxylato, isocitratolactone and Z-iminodiacetato where Z is bound to the nitrogen and is ethyl, propyl, Isopropyl, n-butyl, sec-butyl, ter-butyl, n-amyl, isoamyl or OH. In one preferred aspect the water-soluble square-planar cis-platinum(II) four-coordinate complex has the formula: EQU trans-R,R-DACH Pt(II) X.sub.2 wherein X is a monovalent cation. Two X substituents are present in the platinum complex. These X substituents are preferably selected from the group consisting of cyclopropanecarboxylato, shikimato, saccharatolactone, galacturonato and N,N-dimethylglycinato. Both X substituents are usually identical butmay be different.Board of Regents, University of Texas Syste
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