570 research outputs found

    USGS/NOAA Workshop on Mycobacteriosis in Striped Bass, May 7-10, 2006, Annapolis, Maryland

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    As a Federal trust species, the well-being of the striped bass (Morone saxatilis) population along the Eastern Seaboard is of major concern to resource users. Striped bass are an extremely valuable commercial and recreational resource. As a principal piscivore in Chesapeake Bay, striped bass directly or indirectly interact with multiple trophic levels within the ecosystem and are therefore very sensitive to biotic and abiotic ecosystem changes. For reasons that have yet to be defined, the species has a high intrinsic susceptibility to mycobacteriosis. This disease has been impacting Chesapeake Bay striped bass since at least the 1980s as indicated by archived tissue samples. However, it was not until heightened incidences of fish with skin lesions in the Pocomoke River and other tributaries of the Chesapeake Bay were reported in the summer and fall of 1996 and 1997 that a great deal of public and scientific interest was stimulated about concerns for fish disease in the Bay. (PDF contains 50 pages

    Perinatal androgens and adult behavior vary with nestling social system in siblicidal boobies

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    BACKGROUND: Exposure to androgens early in development, while activating adaptive aggressive behavior, may also exert long-lasting effects on non-target components of phenotype. Here we compare these organizational effects of perinatal androgens in closely related Nazca (Sula granti) and blue-footed (S. nebouxii) boobies that differ in neonatal social system. The older of two Nazca booby hatchlings unconditionally attacks and ejects the younger from the nest within days of hatching, while blue-footed booby neonates lack lethal aggression. Both Nazca booby chicks facultatively upregulate testosterone (T) during fights, motivating the prediction that baseline androgen levels differ between obligately siblicidal and other species. METHODOLOGY/PRINCIPAL FINDINGS: We show that obligately siblicidal Nazca boobies hatch with higher circulating androgen levels than do facultatively siblicidal blue-footed boobies, providing comparative evidence of the role of androgens in sociality. Although androgens confer a short-term benefit of increased aggression to Nazca booby neonates, exposure to elevated androgen levels during this sensitive period in development can also induce long-term organizational effects on behavior or morphology. Adult Nazca boobies show evidence of organizational effects of early androgen exposure in aberrant adult behavior: they visit unattended non-familial chicks in the colony and direct mixtures of aggression, affiliative, and sexual behavior toward them. In a longitudinal analysis, we found that the most active Non-parental Adult Visitors (NAVs) were those with a history of siblicidal behavior as a neonate, suggesting that the tendency to show social interest in chicks is programmed, in part, by the high perinatal androgens associated with obligate siblicide. Data from closely related blue-footed boobies provide comparative support for this interpretation. Lacking obligate siblicide, they hatch with a corresponding low androgen level, and blue-footed booby adults show a much lower frequency of NAV behavior and a lower probability of behaving aggressively during NAV interactions. This species difference in adult social behavior appears to have roots in both pleiotropic and experiential effects of nestling social system. CONCLUSIONS/SIGNIFICANCE: Our results indicate that Nazca boobies experience life-long consequences of androgenic preparation for an early battle to the death

    Experimental study of CO2 sequestration by ECBM recovery: the case of Sulcis coal.

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    An ECBM (Enhanced Coal Bed Methane) feasibility study started for the Sulcis Coal Province (SW Sardinia, Italy) in December 2004: geochemical, structural-geology, stratigraphic and reservoir engineering considerations are discussed. The first newly gathered experimental data are discussed, including: fluid geochemistry (major and minor elements, dissolved gases, C and He isotopic ratios) of the reservoir, coal composition and experimental data on CO2/CH4 adsorption on coal. A MapInfo GIS structure was built up including stratigraphical, geo-structural, hydrogeochemical, coal-compositional and environmental impact information as well as the CO2 sources location and typology. Even if these data could be preliminary with respect to the coal characteritics effectively located at the future injection depth, they highlighted both the challenging positive and negative aspects of the Sulcis Coal Province versus the exploitation of the ECBM technique. The most important objective of this phase I of the project is the selection of the best Sulcis ECBM test-pilot site, which will be followed (Phase II) by the choice of a scaled up site and possibly by a future network (Phase III). These phases are foreseen to be accompanied by the selection of progressively added CO2 industrial sources, to be used within the project economic spreadsheet model, actually in evolution. CO2 geological storage and CH4 production potentials in Sulcis have been grossly evaluated as a whole, in the frame of the Sardinia region CO2 sources, including the coal-fired power plants, both existent and foreseen (hundreds of millions of tonns of CO2 are possible to be stored underground in the next decades). The reservoir estimates, both for the CO2 injection and for the CH4 production are clearly involving to start the test-site phase exploitation, in the frame of an auspicabile international operative project

    Encounters With Ethical Problems During the First 5 Years of Practice in Occupational Therapy: A Survey

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    Background: Health care professionals face ethical problems in practice, but there is little research on types of ethical problems encountered or ethical problem resolution. This study explored ethical problems encountered by occupational therapists and occupational therapy assistants (OTAs) within the first 5 years of practice. Method: Investigators sent a survey in cooperation with NBCOT to a sample of 7,800 occupational therapists and OTAs in multiple practice settings who were NBCOT certified within the past five years. The survey covered questions regarding ethical problems encountered in practice, including productivity and related issues, clinical decision-making and professional reasoning, therapeutic relationships, and employer/employee and colleague relationships. Results: Occupational therapists and OTAs (n = 125) completed the survey. The most consistently encountered types of ethical problems included productivity and related issues and conflicts over clinical decision-making. Occupational therapists and OTAs working in adult and older adult settings reported more consistent encounters with ethical problems than practitioners in other settings. Occupational therapists and OTAs who have been NBCOT certified for longer experienced ethical problems more consistently. Conclusion: Implications included providing more support in specific ethics topics for practitioners within the first 5 years. Further research in which types of ethics education best prepare practitioners to manage ethical issues is warranted

    Insights into the Second Law of Thermodynamics from Anisotropic Gas-Surface Interactions

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    Thermodynamic implications of anisotropic gas-surface interactions in a closed molecular flow cavity are examined. Anisotropy at the microscopic scale, such as might be caused by reduced-dimensionality surfaces, is shown to lead to reversibility at the macroscopic scale. The possibility of a self-sustaining nonequilibrium stationary state induced by surface anisotropy is demonstrated that simultaneously satisfies flux balance, conservation of momentum, and conservation of energy. Conversely, it is also shown that the second law of thermodynamics prohibits anisotropic gas-surface interactions in "equilibrium", even for reduced dimensionality surfaces. This is particularly startling because reduced dimensionality surfaces are known to exhibit a plethora of anisotropic properties. That gas-surface interactions would be excluded from these anisotropic properties is completely counterintuitive from a causality perspective. These results provide intriguing insights into the second law of thermodynamics and its relation to gas-surface interaction physics.Comment: 28 pages, 11 figure

    Polychromatic immunophenotypic characterization of T cell profiles among HIV-infected patients experiencing immune reconstitution inflammatory syndrome (IRIS)

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    Abstract Objective To immunophenotype CD4+ and CD8+ T cell sub-populations in HIV-associated immune reconstitution inflammatory syndrome (IRIS). Design Nested case-control immunological study. Methods ART-naïve HIV-infected patients were prospectively observed for IRIS during the first 6 months of ART. Twenty-two IRIS cases and 22 ART-duration matched controls were sampled for T cell immunophenotyping. Results IRIS cases demonstrated significantly lower CD4 cell counts compared to controls (baseline: 79 versus 142, p = 0.02; enrollment: 183 versus 263, p = 0.05, respectively) with no differences in HIV RNA levels. Within CD4+T cells, cases exhibited more of an effector memory phenotype compared to controls (40.8 versus 27.0%, p = 0.20), while controls trended towards a central memory phenotype (43.8 versus 30.8%, p = 0.07). Within CD8+ T cells, controls exhibited more central memory (13.9 versus 7.81%, p = 0.01, respectively) and effector (13.2 versus 8.8%, p = 0.04, respectively) phenotypes compared to cases, whereas cases demonstrated more terminal effectors than controls (28.8 versus 15.1%, p = 0.05). Cases demonstrated increased activation of CD8+ T cell effector memory, terminal effector, and effector subsets than controls (p = 0.04, 0.02, and 0.02, respectively). Conclusion CD4+ and CD8+ T cell subset maturational phenotypes were heterogeneous among IRIS cases and controls. However, IRIS cases demonstrated significant increases in activation of CD8+ T cell effector subpopulations

    Phytic Acid Exposure Alters AflatoxinB1-induced Reproductive and Oxidative Toxicity in Albino Rats (Rattus norvegicus)

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    The increased use of feed in Egypt's aquaculture and animal industries raises concerns about the possible presence of mycotoxins in feedstuffs. The use of alternative medicine, such as botanicals and nutritional supplements, has become popular with inflammatory cases. The present study aimed to testify the role played by phytic acid (IP6) in enhancing the reproductive and oxidative toxicity induced in aflatoxinB1 (AFB1) treated white male albino rats (Rattus norvegicus) throughout treatment and withdrawal periods. One hundred and twenty white male albino rats were grouped into four groups. Group 1, was injected with 300 μg kg−1 body wt of AFB1 once every 3 days for 15 days and left uninjected for another 15 days to study the withdrawal effect. Group 2, was injected with 300 μg kg−1 body wt of AFB1 once every 3 days for 15 days and treated simultaneously with IP6 daily for another 15 days. Group 3, was treated daily with IP6 (40 mg kg−1 body wt) for 15 days and with no treatment for other 15 days. Group 4, injected with equivalent volume of sterile phosphate buffer saline solution as a control group. Sera were taken at the experimental intervals and assayed for testosterone hormone, follicular-stimulating hormone (FSH) and luteinizing hormone (LH) to determine the toxicological impact of AFB1 and the possibility of amelioration by phytic acid on the reproductive performance of the studied animal. The effects of AFB1 treatment on the absolute and relative weight of testis as well as its histopathologic effect on the testis and the possibility of amelioration by IP6 treatment were evaluated. The activities of enzymatic and non-enzymatic anti-oxidants, in addition to lipid peroxidation were measured in the testis’ homogenate of AFB1-treated rats. A decrease in sex hormone levels, an increase in testicular lipid peroxidation product levels and a significant decrease in testicular glutathione content, catalase and total peroxidase and superoxide dismutase activities were recorded. The histopathologic alterations revealed a degeneration and highly mitotic division within the spermatogenic nuclei, in addition to some karyomegaly and nuclear pyknosis. It is concluded that the reduction in the toxicity of free radicals by phytic acid might be responsible for the protective influence observed
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