623 research outputs found
History and status of the VIMS fish collection (1951-1992)
The fish collection housed at the Virginia Institute of Marine Science of the College of William and Mary provides an important resource for taxonomic, systematic and ecological investigations of freshwater, estuarine and marine fishes. The uniqueness of the collection is in part due to its historical significance as well as a close coupling with a strong graduate program in ichthyology. The collection has internationally recognized holdings of Chesapeake Bay, middle Atlantic Bight and deep-water marine fishes, as well as freshwater fishes of the southern Appalachians. These collections have provided the basis for numerous graduate research projects and investigations by systematists from many institutions. In addition, rapidly expanding collections of early life history stages of fishes from Chesapeake Bay, middle Atlantic Bight and Caribbean localities offer an important and unique source of material for ontogenetic studies
Fish assemblages at a deep-water sewage disposal site (DWD-106) : a final contract report
Deep-water dumpsite 106 is located over the continental slope and rise about 106 miles east of New Jersey (Fig. 1). From March 1986 to July 1992 approximately eight million wet metric tons of sewage sludge were disposed there per year (Robertson and Redford, 1992). Because of the potential impact of this dumping on deep-sea ecosystems, NOAA/NMFS contracted the Virginia Institute of Marine Science, College of William and Mary (VIMS) to make otter-trawl collections in and around DWD 106 in 1990 and 1991. Specific objectives of these collections were:
1. To sample the demersal megafauna, especially fishes;
2. To provide frozen series of dominant species of fishes and invertebrates to NMFS for subsequent heavy metal and organic analyses;
3. To provide a description of the demersal fish community structure in the area; 4. To compare these data with similar data collected from 1973 to 1978 from DWD 106 and an adjacent area to the south near Norfolk submarine canyon.
This final contract report summarizes the results of these studies
Stock Identification of summer Flounder (Paralichthis dentatus) in the Southern Mid-Atlantic Bight
A total of 12, 339 summer flounder were tagged from Virginia waters during 1987-89. A total of 874 were recaptured for an overall return rate of 7 . 1%. Most of the returns ( 48.5%) were from Virginia waters, or areas to the south. A smaller number ( 21.6%) were from areas north and offshore of Virginia. Another 29. 9% were recaptured and returned with inadequate location data. Examining only the returns with adequate location data, yielded a separation of 69.2% and 30.8% between the groups. No differences were noted in the sizes at tagging between these groups. Tagged flounder held at VIMS exhibited no behavioral differences from untagged fish. No differences in growth and mortality were noted in these fish. The sex ratio of males to females was 1:1.16. Male summer flounder reached 50% maturity at approximately 280 mm, while females reached 50% maturity at about 330 mm. A total of 1040 flounder were successfully aged. The population was dominated by young fish ( 0- 2 years old). The compression of age structure i s indicative of a population being heavily overfished
Alternative antiretroviral monitoring strategies for HIV-infected patients in east Africa: opportunities to save more lives?
<p>Abstract</p> <p>Background</p> <p>Updated World Health Organization guidelines have amplified debate about how resource constraints should impact monitoring strategies for HIV-infected persons on combination antiretroviral therapy (cART). We estimated the incremental benefit and cost effectiveness of alternative monitoring strategies for east Africans with known HIV infection.</p> <p>Methods</p> <p>Using a validated HIV computer simulation based on resource-limited data (USAID and AMPATH) and circumstances (east Africa), we compared alternative monitoring strategies for HIV-infected persons newly started on cART. We evaluated clinical, immunologic and virologic monitoring strategies, including combinations and conditional logic (e.g., only perform virologic testing if immunologic testing is positive). We calculated incremental cost-effectiveness ratios (ICER) in units of cost per quality-adjusted life year (QALY), using a societal perspective and a lifetime horizon. Costs were measured in 2008 US dollars, and costs and benefits were discounted at 3%. We compared the ICER of monitoring strategies with those of other resource-constrained decisions, in particular earlier cART initiation (at CD4 counts of 350 cells/mm<sup>3 </sup>rather than 200 cells/mm<sup>3</sup>).</p> <p>Results</p> <p>Monitoring strategies employing routine CD4 testing without virologic testing never maximized health benefits, regardless of budget or societal willingness to pay for additional health benefits. Monitoring strategies employing virologic testing conditional upon particular CD4 results delivered the most benefit at willingness-to-pay levels similar to the cost of earlier cART initiation (approximately 4400/QALY) that greatly exceeded the ICER of earlier cART initiation.</p> <p>Conclusions</p> <p>CD4 testing alone never maximized health benefits regardless of resource limitations. Programmes routinely performing virologic testing but deferring cART initiation may increase health benefits by reallocating monitoring resources towards earlier cART initiation.</p
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Spent fuel treatment and mineral waste form development at Argonne National Laboratory-West
At Argonne National Laboratory-West (ANL-West) there are several thousand kilograms of metallic spent nuclear fuel containing bond sodium. This fuel will be treated in the Fuel Conditioning Facility (FCF) at ANL-West to produce stable waste forms for storage and disposal. Both mineral and metal high-level waste forms will be produced. The mineral waste form will contain the active metal fission products and the transuranics. Cold small-scale waste form testing has been on-going at Argonne in Illinois. Large-scale testing is commencing at ANL-West
Sharks, rays and marine protected areas: a critical evaluation of current perspectives
Marine protected areas (MPAs) are increasingly advocated for the conservation and management of sharks and rays. However, substantial uncertainty remains regarding which species can benefit from MPAs. Meanwhile, area-focused protection targets have spurred recent and rapid gains in the creation of large MPAs, many of which carry vague objectives set by a diverse group of stakeholders with potentially different notions of "success." Here, we capture and critically evaluate current views on the use of MPAs for shark and ray conservation. Through interviews with scientists, MPA managers, fisheries experts, conservation practitioners, advocates and policy experts (n = 53), we demonstrate a variety of perspectives regarding: (a) the effectiveness of MPAs as a tool for shark and ray conservation; (b) which factors influence the success of MPAs for sharks and rays; and (c) the desired outcomes of these MPAs. While MPAs created specifically for sharks and rays were viewed to be slightly more effective than regular MPAs as a tool for shark and ray conservation, both were generally considered insufficient in isolation. Despite greater emphasis on social success factors (e.g., local support) over biophysical success factors (e.g., size), biological outcomes (e.g., increased abundance) were prioritized over social outcomes (e.g., livelihood benefits). We argue that a stronger focus on achieving social outcomes can enhance the potential for MPAs to benefit sharks and rays. In revealing current thinking regarding the drivers and indicators of MPA success for sharks and rays, the results of this study can inform efforts to conserve and manage these species
Intraspecific Variation in Vertical Habitat Use by Tiger Sharks (Galeocerdo cuvier) in the Western North Atlantic
Tiger sharks (Galeocerdo cuvier) are a wide ranging, potentially keystone predator species that display a variety of horizontal movement patterns, making use of coastal and pelagic waters. Far less, however, is known about their vertical movements and use of the water column. We used pop-up satellite archival tags with two data sampling rates (high rate and standard rate tags) to investigate the vertical habitat use and diving behavior of tiger sharks tagged on the Puerto Rico–Virgin Islands platform and off Bermuda between 2008 and 2009. Useable data were received from nine of 14 sharks tagged, tracked over a total of 529 days. Sharks spent the majority of their time making yo-yo dives within the upper 50 m of the water column and considerable time within the upper 5 m of the water column. As a result, sharks typically occupied a narrow daily temperature range (~2°C). Dives to greater than 200 m were common, and all sharks made dives to at least 250 m, with one shark reaching a depth of 828 m. Despite some similarities among individuals, a great deal of intraspecific variability in vertical habit use was observed. Four distinct depth distributions that were not related to tagging location, horizontal movements, sex, or size were detected. In addition, similar depth distributions did not necessitate similar dive patterns among sharks. Recognition of intraspecific variability in habitat use of top predators can be crucial for effective management of these species and for understanding their influence on ecosystem dynamics
Civil Liberties and Volunteering in Six Former Soviet Union Countries
To contribute to the debate as to whether volunteering is an outcome of
democratization rather than a driver of it, we analyze how divergent democratization
pathways in six countries of the former Soviet Union have led to varied levels of
volunteering. Using data from the European Values Study, we find that Latvia, Lithuania,
and Estonia—which followed a Europeanization path—have high and increasing levels
of civil liberties and volunteering. In Russia and Belarus, following a pre-emption path,
civil liberties have remained low and volunteering has declined. Surprisingly, despite
the Orange Revolution and increased civil liberties, volunteering rates in Ukraine
have also declined. The case of Ukraine indicates that the freedom to participate
is not always taken up by citizens. Our findings suggest it is not volunteering that
brings civil liberties, but rather that increased civil liberties lead to higher levels of
volunteerin
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