8,250 research outputs found
Effects of stress on the immune system of fish
The effects of stress on the immune system of various fish species including dab Limanda limanda, flounder Platichthys flesus, sea bass Dicentrarchus labrax and gobies Zosterisessor ophiocephalus, were investigated from laboratory and field experiments, using various assays to measure immunocompetence, correlated with histological and ultrastructural observations. Modulation of the immune system was demonstrated at tissue, cellular and biochemical levels following exposure to various stressors. The spleen somatic index was depressed in dab stressed in the laboratory and gobies collected from polluted sites in the Venice Lagoon. Differential blood cell counts consistently showed an increase in phagocytes and decrease in thrombocytes in fish exposed to various stressors. Phagocytic activity from spleen and kidney adherent cells was stimulated in dab stressed by transportation but depressed in fish exposed to chemical pollutants. Respiratory burst activity in phagocytic cells was also stimulated in stressed dab but depressed in sea bass exposed to cadmium. The results are discussed in relation to current concepts on stress in fish and the regulation of the immune system
Ready4Work In Brief: Update on Outcomes; Reentry May Be Critical for States, Cities
This issue of P/PV In Brief provides updated data from the Ready4Work prisoner reentry initiative, with a focus on the prison crisis occurring in many cities and states. While much more research is needed to understand the true, long-term impact of prisoner reentry initiatives, outcomes from Ready4Work were extremely promising in terms of education, employment and program retention, with recidivism rates among Ready4Work participants 34 to 50 percent below the national average.Funded by the US Department of Labor and the Annie E. Casey and Ford foundations, Ready4Work was a three-year national demonstration project designed to address the needs of the growing ex-prisoner population and to test the capacity of community- and faith-based organizations to meet those needs. Ready4Work programs provided employment services, case management and mentoring in 11 adult sites around the country (data from seven juvenile sites are being analyzed separately)
Improving the spatial resolution by effective subtraction technique at Irkutsk incoherent scatter radar: the theory and experiment
We describe a sounding technique that allows us to improve spatial resolution
of Irkutsk Incoherent Scatter Radar without loosing spectral resolution. The
technique is based on transmitting of rectangle pulses of different duration in
various sounding runs and subtracting correlation matrixes. Theoretically and
experimentally we have shown, that subtraction of the mean-square parameters of
the scattered signal for different kinds of the sounding signal one from
another allows us to solve the problem within the framework of quasi-static
ionospheric parameters approximation.Comment: 4 pages, 3 figures, to appear at URSI-2011 conferenc
Illuminating Solutions: The Youth Violence Reduction Partnership
Over the last decade, P/PV has undertaken several studies of the Philadelphia-based Youth Violence Reduction Partnership (YVRP), an intensive collaboration that targets young people deemed at highest risk of being involved in a homicide. YVRP provides young probationers with enhanced supervision and support, with the goal of keeping them out of trouble and putting them on a path toward productive adulthood
Appropriate Selection Processes Are Available For Choosing Hospitality texts
First Student: I know what you mean; I fall asleep every time I try to read this stuff.
(Meanwhile, in the faculty lounge) First Professor: I do not understand what\u27s wrong with my students; they expect me to teach textbook information from the podium.
Second Professor: I\u27ve noticed the same thing. They do not want to be responsible for their readings
Geochemistry of Kauai shield-stage lavas: Implications for the chemical evolution of the Hawaiian plume
We measured He, Sr, Nd, Pb, and Os isotope ratios and major and trace element concentrations in stratigraphically and paleomagnetically controlled shield-stage lavas from Kauai, Hawaii. The range of 3He/4He ratios (17–28 RA) from Kauai is similar to that reported from Loihi and thus challenges the prevailing notion that high 3He/4He ratios are restricted to the preshield stage of Hawaiian magmatism. 3He/4He ratios vary erratically with stratigraphic position, and chronostratigraphic control from paleomagnetic data indicates very rapid changes in the 3He/4He ratios (up to 8 RA in ~102 years). These variations in helium isotopic ratios are correlated with variations in radiogenic isotope ratios, suggesting rapid changes in melt composition supplying the magma reservoir. A three-component mixing model, previously proposed for Hawaiian shield lavas, does not adequately explain the isotopic data in Kauai shield lavas. The addition of a depleted-mantle (DM) component with the isotopic characteristics similar to posterosional basalts explains the isotopic variability in Kauai shield lavas. The DM component is most apparent in lavas from the Kauai shield and is present in varying proportion in other Hawaiian shield volcanoes. Shield lavas from Kauai sample a high 3He/4He end-member (Loihi component), but while lavas from western Kauai have a larger contribution from the Kea component (high 206Pb/204Pb, anomalously low 207Pb/204Pb relative to 206Pb/204Pb), lavas from eastern Kauai have a larger proportion of an enriched (Koolau) component. The systematic isotopic differences between eastern and western Kauai reflect a gradual migration of the locus of volcanism from west to east, or alternatively east and west Kauai are two distinct shield volcanoes. In the latter case, the two shield volcanoes have maintained distinct magma supply sources and plumbing systems. Our new geochemical data from Kauai are consistent with the existence of a single high 3He/4He reservoir in the Hawaiian plume and suggest that the proportion of the different mantle components in the plume have changed significantly in the past 5 Myr. The long-term evolution of the Hawaiian plume and the temporal variability recorded in Kauai lavas require more complex geochemical heterogeneities than suggested by radially zoned plume models. These complexities may arise from heterogeneities in the thermal boundary layer and through variable entrainment of ambient mantle by the upwelling plume
- …
