564 research outputs found
Down and out? the role of household income in students’ friendship formation in school-classes
Sexual identity disparities in mental health among U.K. adults, U.S. adults, and U.S. adolescents:Examining heterogeneity by race/ethnicity
Lesbian, gay, and bisexual (LGB) people report poorer mental health than heterosexual people. However, there is heterogeneity in this disparity, and a racial/ethnic minority identity can contribute to this heterogeneity. When studying the intersecting effect of sexual identity and race/ethnicity on mental health, research often limits race/ethnicity categories, often uses adult samples from the U.S., and often uses samples that are not nationally representative. To overcome these limitations, the present study examined racial/ethnic heterogeneity in mental health disparities between heterosexual and LGB people in three nationally representative samples. The samples used were the 2011–2012 Understanding Society (U.K. adults; N = 43,904), the 2015 National Survey on Drug Use and Health (U.S. adults; N = 43,313), and the 2015 Youth Risk Behavior Survey (U.S. adolescents; N = 15,122). Using these samples enabled us to contrast the intersection of sexual identity and race/ethnicity across countries (for adults), and between life phases (in the U.S.). Across all three samples, LGB people—and particularly bisexual people—had a higher risk of impaired mental health than heterosexual people. For U.K. adults and U.S. adults, no intersecting effect of sexual identity and race/ethnicity were found. LGB adolescents of color reported better mental health compared with White LGB adolescents. More specifically, Black LGB adolescents reported better mental health compared to White LGB adolescents. Together, the present study contributes to a better understanding of the heterogeneity in mental health disparities for LGB people
Analysis of the relationships between Patagonian squid (Doryteuthis gahi)
Doryteuthis (Loligo) gahi is the second most important cephalopod species in the SW
Atlantic from a fisheries point of view. This species and hence, the fisheries profitability
and sustainability, are subject to large inter-annual variability in recruitment strength,
mainly due to interannual and seasonal variations of the Falkland/Malvinas Current. In
this working document we analyse the environmental, geographical, temporal and
physical factors affecting the distribution (abundance) of D. gahi in two areas where its
abundance is highest, using geographic information systems tools. We found a slight
positive correlation between CPUE and longitude, as well as between CPUE and depth
in the northern area, but no correlations could be found between SST and the other
explanatory variables. Regarding the southern area in summer-autumn, we found that
CPUE increases with longitude as we go to the east, and with latitude. We also found
positive correlations between SST and CPUE, as well as with depth. In winter spring
our study revealed a slight relationship between CPUE and location, and with depth
Analysis of the relationship between Argentine short-finned squid (Illex argentinus) abundance and environmental parameters in the SW Atlantic Ocean using GIS tools
The Argentine short-finned squid Illex argentinus is the main cephalopod species which occurs in the Southwest Atlantic Ocean. It is the most highly fished species in terms of catches and is the major target of large-scale directed fishing carried out by “jiggers”, and to a lesser extent, by trawlers. The variability of main current systems in the region (Brazil and Falkland/Malvinas Currents) has been suggested to influence the abundance and distribution of I. argentinus, thus largely affecting profitability and sustainability of the fisheries. In this working document we analyse the environmental, geographical, temporal and physical factors affecting the distribution (abundance) of I. argentinus in two areas of highest distribution, using geographic information systems tools. Strong correlation was found between Illex abundance and the season of the year, as well as with latitude, confirming our knowledge of the fishery and the literature on this specie
On the estimation of time dependent lift of a European Starling during flapping
We study the role of unsteady lift in the context of flapping wings in birds'
flight. Both aerodynamicists and biologists attempt to address this subject,
yet it seems that the contribution of the unsteady lift still holds many open
questions. The current study deals with the estimation of unsteady aerodynamic
forces on a freely flying bird through analysis of wingbeat kinematics and near
wake flow measurements using time resolved particle image velocimetry. The
aerodynamic forces are obtained through unsteady thin airfoil theory and lift
calculation using the momentum equation for viscous flows. The unsteady lift is
comprised of circulatory and non-circulatory components. Both are presented
over wingbeat cycles. Using long sampling data, several wingbeat cycles have
been analyzed in order to cover the downstroke and upstroke phases. It appears
that the lift varies over the wingbeat cycle emphasizing its contribution to
the total lift and its role in power estimations. It is suggested that the
circulatory lift component cannot assumed to be negligible and should be
considered when estimating lift or power of birds in flapping motion
Roughening kinetics of chemical vapor deposited copper films on Si(100)
3 pages, 3 figures.The roughening kinetics of copper films synthesized by low pressure chemical vapor deposition (LPCVD) on Si(100) substrates was investigated by scanning tunneling microscopy (STM). By applying the dynamic scaling theory to the STM images, a steady growth roughness exponent (alfa)=0.81 ± 0.05 and a dynamic growth roughness exponent (beta)=0.62 ± 0.09 were determined. The value of (alfa) is consistent with growth model predictions incorporating surface diffusion. The value of
(beta), while higher than expected from these models, can be related to LPCVD processing conditions favoring growth instabilities.This work was partially supported by the CSICCONICET
cooperation program and by a grant from the
NASA New Jersey Space Grant Consortium.Peer reviewe
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