The effects of electron and proton radiation on GaSb infrared solar cells

Gallium antimonide (GaSb) infrared solar cells were exposed to 1 MeV electrons and protons up to fluences of 1 times 10(exp 15) cm (-2) and 1 times 10(exp 12) cm (-2) respectively. In between exposures, current voltage and spectral response curves were taken. The GaSb cells were found to degrade slightly less than typical GaAs cells under electron irradiation, and calculations from spectral response curves showed that the damage coefficient for the minority carrier diffusion length was 3.5 times 10(exp 8). The cells degraded faster than GaAs cells under proton irradiation. However, researchers expect the top cell and coverglass to protect the GaSb cell from most damaging protons. Some annealing of proton damage was observed at low temperatures (80 to 160 C)

Multi-level study of C3H2: The first interstellar hydrocarbon ring

Cyclic species in the interstellar medium have been searched for almost since the first detection of interstellar polyatomic molecules. Eleven different C3H2 rotational transitions were detected; 9 of which were studied in TMC-1, a nearby dark dust cloud, are shown. The 1 sub 10 yields 1 sub 01 and 2 sub 20 yields 2 sub 11 transitions were observed with the 43 m NRAO telescope, while the remaining transitions were detected with the 14 m antenna of the Five College Radio Observatory (FCRAO). The lines detected in TMC-1 have energies above the ground state ranging from 0.9 to 17.1 K and consist of both ortho and para species. Limited maps were made along the ridge for several of the transitions. The HC3N J = 2 yields 1 transition were mapped simultaneously with the C3H2 1 sub 10 yields 1 sub 01 line and therefore can compare the distribution of this ring with a carbon chain in TMC-1. C3H2 is distributed along a narrow ridge with a SE - NW extension which is slightly more extended than the HC2N J = 2 yields 1. Gaussian fits gives a FWHP extension of 8'5 for C3H2 while HC3N has a FWHP of 7'. The data show variations of the two velocity components along the ridge as a function of transition. Most of the transitions show a peak at the position of strongest HC3N emission while the 2 sub 21 yields 2 sub 10 transition shows a peak at the NH3 position

Prioritizing Management and Research Actions against Invasive Reptiles in Florida: A Collaboration by an Expert Panel

Florida has more introduced animals than any other region of the U.S. and also ranks high in this respect globally. Given Florida\u27s climate, it is no coincidence that a large proportion of Florida’s invasive vertebrate species are reptiles and amphibians. Exotic snakes, lizards, frogs, turtles, and crocodilians are all breeding in Florida. The largest snakes in Florida are constrictors from other continents, and the five largest lizard species breeding in Florida are from Africa, South America, and Central America. Establishment of non-native reptiles and amphibians has been documented in Florida for over 135 years, and the rate of invasive reptile species establishment has been accelerating in the last half century. Florida currently has 16 native lizard species compared to 43 invasive species of lizard established and breeding in the state. Florida\u27s subtropical climate in the south, its major ports of entry for many wildlife species to the U.S. (both legal and illegal), its thriving captive wildlife industry, and its location in an area of destructive hurricanes that can release captive animals make the state particularly susceptible to the introduction and establishment of a wide range of species. Moreover, Florida is isolated from land with similar climates, resulting in the state\u27s vertebrates typically originating in the southeast U.S. at the southern extremes of their range. Invaders to Florida therefore find relatively fewer native species to contend with than in most tropical/subtropical locations

A luciferase based viability assay for ATP detection in 384-well format for high throughput whole cell screening of Trypanosoma brucei brucei bloodstream form strain 427

<p>Abstract</p> <p>Background</p> <p>Human African Trypanosomiasis (HAT) is caused by two trypanosome species, <it>Trypanosoma brucei rhodesiense </it>and <it>Trypanosoma brucei gambiense</it>. Current drugs available for the treatment of HAT have significant issues related to toxicity, administration regimes with limited effectiveness across species and disease stages, thus there is a considerable need to find alternative drugs. A well recognised approach to identify new drug candidates is high throughput screening (HTS) of large compound library collections.</p> <p>Results</p> <p>We describe here the development of a luciferase based viability assay in 384-well plate format suitable for HTS of <it>T.b.brucei</it>. The parameters that were explored to determine the final HTS assay conditions are described in detail and include DMSO tolerability, Z', diluents and cell inoculum density. Reference compound activities were determined for diminazene, staurosporine and pentamidine and compared to previously published IC₅₀data obtained. The assay has a comparable sensitivity to reference drugs and is more cost effective than the 96-well format currently reported for <it>T.b.brucei</it>.</p> <p>Conclusion</p> <p>Due to the reproducibility and sensitivity of this assay it is recommended for potential HTS application. As it is commercially available this assay can also be utilised in many laboratories for both large and small scale screening.</p

Prioritizing Management and Research Actions against Invasive Reptiles in Florida: A Collaboration by an Expert Panel

Florida has more introduced animals than any other region of the U.S. and also ranks high in this respect globally. Given Florida\u27s climate, it is no coincidence that a large proportion of Florida’s invasive vertebrate species are reptiles and amphibians. Exotic snakes, lizards, frogs, turtles, and crocodilians are all breeding in Florida. The largest snakes in Florida are constrictors from other continents, and the five largest lizard species breeding in Florida are from Africa, South America, and Central America. Establishment of non-native reptiles and amphibians has been documented in Florida for over 135 years, and the rate of invasive reptile species establishment has been accelerating in the last half century. Florida currently has 16 native lizard species compared to 43 invasive species of lizard established and breeding in the state. Florida\u27s subtropical climate in the south, its major ports of entry for many wildlife species to the U.S. (both legal and illegal), its thriving captive wildlife industry, and its location in an area of destructive hurricanes that can release captive animals make the state particularly susceptible to the introduction and establishment of a wide range of species. Moreover, Florida is isolated from land with similar climates, resulting in the state\u27s vertebrates typically originating in the southeast U.S. at the southern extremes of their range. Invaders to Florida therefore find relatively fewer native species to contend with than in most tropical/subtropical locations

Social Capital Impact On Service Supply Chains

Purpose This study explores the impact of social capital on service firm supply chains.Design/methodology/approach The theoretical underpinnings of social capital is reviewed from various disciplines, including sociology, management, and operations management. This is used to develop a conceptual model of the use of social capital in a service supply chain setting.Findings - Social capital is proposed to improve the operational performance of service firms as a source of both physical and information resources. The impact of social capital is projected to vary by firm size and service type. Small firms have limited resources and thus a need for resources obtained through social capital. Service firms that have high customization and customer contact are subject to process variations which can be mitigated by social capital. A conceptual model is presented to test several propositions related to social capital.Originality/value The impact of social capital has not been widely studied in an operational setting. This is the first known study to specifically analyze the impact of social capital in service supply chains

Allowable Take of Black Vultures in the Eastern United States

Black vultures (Coragyps atratus) have been increasing in density and expanding their range in the eastern United States since at least the 1960s. In many areas, their densities have increased to the level where they are causing damage to property and livestock and the number of requests for allowable take permits has increased throughout these areas. The United States Fish and Wildlife Service (USFWS) requires updated information to help inform the number of take permits that could reduce conflicts while meeting obligations under the Migratory Bird Treaty Act.We expanded analyses used to estimate allowable take in Virginia to cover the range of black vultures in the eastern United States. We used the prescribed take level approach, which integrates demographic rates, population size estimates, and management objectives into an estimate of allowable take. We provide estimates of allowable take at 4 different scales: individual states, Bird Conservation Regions, USFWS administrative regions, and flyways. Our updated population time series provides evidence of rapidly increasing black vulture populations in many regions of the eastern United States, with an overall population estimate of approximately 4.26 million in 2015 in the Atlantic and Mississippi Flyways. Estimated allowable take ranged from a few hundred individuals per year in states at the northern end of the species range to approximately 287,000/year over the entire eastern United States. The USFWS has no legal mandate regarding the spatial scale at which take should be managed and we found little biological evidence of subpopulation structure for black vultures in the eastern United States.We suggest that allowable take for the species be implemented at a scale that meets stakeholder objectives (e.g., reducing conflict, and ensuring that black vultures are not extirpated from local areas) and is efficient for administrative and monitoring purposes. Published 2018. This article is a U.S. Government work and is in the public domain in the USA

Assessing the Hazard to Granivorous Birds Feeding on Chemically Treated Seeds

Current methods for evaluating hazards to seed-eating birds are based on estimated exposure per unit area and assume that birds ingest all of the chemical on a treated seed. In an earlier study, however, it was determined that red-winged blackbirds removed only about 15% of an insecticidal treatment applied to individual rice seeds. Here, we extend those findings by examining the seed-handling behavior of four granivorous bird species exposed to millet, rice, sunflower and sorghum treated with imidacloprid. Mourning doves (Zenaida macroura L.) swallowed the seed whole. House finches (Carpodacus mexicanus Muller), red-winged blackbirds (Agelaius phoeniceus L.) and boat-tailed grackles (Quiscalus major Vieillot) discarded the seed hulls, however, and removed only 15È40% of the initial chemical treatment. Residues on seed hulls decreased as handling time increased. Sunflowers had the lowest residues because birds repeatedly handled the hull to remove bits of the oily kernel. These results suggest that avian hazard assessment methods should incorporate species-typical seed-handling behavior to assess more accurately birds’ exposure to chemicals on different types of seed

Ds+→ϕρ+D_s^+ \to \phi \rho^+ Decay

Motivated by the experimental measurement of the decay rate, $\Gamma$, and the longitudinal polarization, $P_L$, in the Cabibbo favored decay $D_s^+\to \phi {\rho}^{+}$, we have studied theoretical prediction within the context of factorization approximation invoking several form factors models. We were able to obtain agreement with experiment for both $\Gamma$ and $P_L$ by using experimentally measured values of the form factors $A_1^{D_s\phi}(0)$, $A_2^{D_s\phi}(0)$ and $V^{D_s\phi}(0)$ in the semi-leptonic decay $D_s^+\to \phi l^{+}\nu_{l}$. We have also included in our calculation the effect of the final state interaction ($fsi$) by working with the partial waves amplitudes $S$, $P$ and $D$. Numerical calculation shows that the decay amplitude is dominated by $S$ wave, and that the polarization is sensitive to the interference between $S$ and $D$ waves. The range of the phase difference $\delta_{SD} = \delta_S - \delta_D$ accommodated by experimental error in $P_L$ is large.Comment: 7 pages, LaTe