Obtaining wildlife values information for management: the wildlife attitudes and values scale (WAVS).

22 page

A guide to managing human activity on national wildlife refuges.

78 page

Tensile strained InxGa1−xPIn_{x}Ga_{1-x}P membranes for cavity optomechanics

We investigate the optomechanical properties of tensile-strained ternary InGaP nanomembranes grown on GaAs. This material system combines the benefits of highly strained membranes based on stoichiometric silicon nitride, with the unique properties of thin-film semiconductor single crystals, as previously demonstrated with suspended GaAs. Here we employ lattice mismatch in epitaxial growth to impart an intrinsic tensile strain to a monocrystalline thin film (approximately 30 nm thick). These structures exhibit mechanical quality factors of 2*10^6 or beyond at room temperature and 17 K for eigenfrequencies up to 1 MHz, yielding Q*f products of 2*10^12 Hz for a tensile stress of ~170 MPa. Incorporating such membranes in a high finesse Fabry-Perot cavity, we extract an upper limit to the total optical loss (including both absorption and scatter) of 40 ppm at 1064 nm and room temperature. Further reductions of the In content of this alloy will enable tensile stress levels of 1 GPa, with the potential for a significant increase in the Q*f product, assuming no deterioration in the mechanical loss at this composition and strain level. This materials system is a promising candidate for the integration of strained semiconductor membrane structures with low-loss semiconductor mirrors and for realizing stacks of membranes for enhanced optomechanical coupling.Comment: 10 pages, 3 figure

Coronavirus and Pasteurella infections in bovine shipping fever pneumonia and Evans\u27 criteria for causation

Respiratory tract infections with viruses and Pasteurella spp. were determined sequentially among 26 cattle that died during two severe epizootics of shipping fever pneumonia. Nasal swab and serum samples were collected prior to onset of the epizootics, during disease progression, and after death, when necropsies were performed and lung samples were collected. Eighteen normal control cattle also were sampled at the beginning of the epizootics as well as at weekly intervals for 4 weeks. Respiratory bovine coronaviruses (RBCV) were isolated from nasal secretions of 21 and 25 cattle before and after transport. Two and 17 cattle nasally shed Pasteurella spp. before and after transport, respectively. RBCV were isolated at titers of 1 x 103 to 1.2 x 107 PFU per g of lung tissue from 18 cattle that died within 7 days of the epizootics, but not from the lungs of the remaining cattle that died on days 9 to 36. Twenty-five of the 26 lung samples were positive for Pasteurella spp., and their CFU ranged between 4.0 x 105 and 2.3 x 109 per g. Acute and subacute exudative, necrotizing lobar pneumonia characterized the lung lesions of these cattle with a majority of pneumonic lung lobes exhibiting fibronecrotic and exudative changes typical of pneumonic pasteurellosis, but other lung lobules had histological changes consisting of bronchiolitis and alveolitis typical of virus-induced changes. These cattle were immunologically naive to both infectious agents at the onset of the epizootics, but those that died after day 7 had rising antibody titers against RBCV and Pasteurella haemolytica. In contrast, the 18 clinically normal and RBCV isolation-negative cattle had high hemagglutinin inhibition antibody titers to RBCV from the beginning, while their antibody responses to P. haemolytica antigens were delayed. Evans\u27 criteria for causation were applied to our findings because of the multifactorial nature of shipping fever pneumonia. This analysis identified RBCV as the primary inciting cause in these two epizootics. These viruses were previously not recognized as a causative agent in this complex respiratory tract disease of cattle

The Temporal and Spatial Connectivity of the Gambles Mill Corridor, Richmond, VA

The City of Richmond and the Virginia Department of Transportation proposed to rehabilitate the Gambles Mill Trail connecting the University of Richmond (UR) to the intersection of Huguenot and River Road. Planners envision this trail as a sustainable model for the reduction of nutrient and sediment flow and as a vital path in a city-wide network of bike and pedestrian trails. Meanwhile, UR also proposes to rehabilitate the corridor in their new Master Plan. Nevertheless, until now, no substantive studies exist on the trail or the corridor linking the trail to the south side of the James River through the hazardous River-Huguenot Road intersection and the Huguenot Bridge currently under construction. The University of Richmond’s Geography 221 Course, Mapping Sustainability: Cartography and Geographic Information in an Environmental Context, is working with a variety of stakeholders (public, private, and community-based) to map the past, present, and future of the Gambles Mill Corridor and influence local and regional sustainability of transportation, hydrology, and recreation in a floodplain ecosystem. Students produce maps grouped around four scales: local corridor, UR to the River, a city scale sustainable transport network, and a temporal scale tracing previous transportation routes in the area such as the 1930s street car system and the colonial canal system.https://scholarship.richmond.edu/geography-posters/1001/thumbnail.jp

Ultrafiltration evaluation with depleted uranium oxide

Scientists at the Los Alamos National Laboratory Plutonium Facility are using electrodissolution in neutral to alkaline solutions to decontaminate oralloy parts that have surface plutonium contamination. Ultrafiltration of the electrolyte stream removes precipitate so that the electrolyte stream to the decontamination fixture is precipitate free. This report describes small-scale laboratory ultrafiltration experiments that the authors performed to determine conditions necessary for full-scale operation of an ultrafiltration module. Performance was similar to what they observed in the ferric hydroxide system. At 12 psi transmembrane pressure, a shear rate of 12,000 sec{sup {minus}1} was sufficient to sustain membrane permeability. Ultrafiltration of uranium(VI) oxide appears to occur as easily as ultrafiltration of ferric hydroxide. Considering the success reported in this study, the authors plan to add ultrafiltration to the next decontamination system for oralloy parts

Mangroves enhance the biomass of coral reef fish communities in the Caribbean

Mangrove forests are one of the world's most threatened tropical ecosystems with global loss exceeding 35% (ref. 1). Juvenile coral reef fish often inhabit mangroves, but the importance of these nurseries to reef fish population dynamics has not been quantified. Indeed, mangroves might be expected to have negligible influence on reef fish communities: juvenile fish can inhabit alternative habitats and fish populations may be regulated by other limiting factors such as larval supply or fishing. Here we show that mangroves are unexpectedly important, serving as an intermediate nursery habitat that may increase the survivorship of young fish. Mangroves in the Caribbean strongly influence the community structure of fish on neighbouring coral reefs. In addition, the biomass of several commercially important species is more than doubled when adult habitat is connected to mangroves. The largest herbivorous fish in the Atlantic, Scarus guacamaia, has a functional dependency on mangroves and has suffered local extinction after mangrove removal. Current rates of mangrove deforestation are likely to have severe deleterious consequences for the ecosystem function, fisheries productivity and resilience of reefs. Conservation efforts should protect connected corridors of mangroves, seagrass beds and coral reefs

Haptic search with finger movements: using more fingers does not necessarily reduce search times

Two haptic serial search tasks were used to investigate how the separations between items, and the number of fingers used to scan them, influence the search time and search strategy. In both tasks participants had to search for a target (cross) between a fixed number of non-targets (circles). The items were placed in a straight line. The target’s position was varied within blocks, and inter-item separation was varied between blocks. In the first experiment participants used their index finger to scan the display. As expected, search time depended on target position as well as on item separation. For larger separations participants’ movements were jerky, resembling ‘saccades’ and ‘fixations’, while for the shortest separation the movements were smooth. When only considering time in contact with an item, search times were the same for all separation conditions. Furthermore, participants never continued their movement after they encountered the target. These results suggest that participants did not use the time during which they were moving between the items to process information about the items. The search times were a little shorter than those in a static search experiment (Overvliet et al. in Percept Psychophys, 2007a), where multiple items were presented to the fingertips simultaneously. To investigate whether this is because the finger was moving or because only one finger was stimulated, we conducted a second experiment in which we asked participants to put three fingers in line and use them together to scan the items. Doing so increased the time in contact with the items for all separations, so search times were presumably longer in the static search experiment because multiple fingers were involved. This may be caused by the time that it takes to switch from one finger to the other