1,166 research outputs found

    Walking the Walk or Just Talk?: A Global Examination of Men’s Intentions to Take Violence Preventative Action

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    Given the increasing prominence of both bystander-based approaches to gender-based violence (GBV) prevention and of proactively engaging men and boys to join efforts to end GBV, understanding the factors that support men’s antiviolence bystander behavior is important. This study examined correlates of willingness to engage in violence preventative bystander behavior in a global sample of 299 adult men engaged in GBV prevention events or work. Participants came from over 50 countries and provided data via an online, anonymous survey available in English, Spanish, and French. Path analysis was used to model participants’ willingness to engage in a variety of violence-preventative behaviors in the future, with variable selection guided by the Theory of Planned Behavior (TPB) and by research implicating gender-related attitudes in bystander willingness and behavior. Findings suggest that bystander willingness was supported by past bystander behavior, self-efficacy to engage in bystander behavior, positive beliefs about the contributions of antiviolence involvement, and by an awareness of male privilege. Social network support for GBV prevention work, and support for gender equity were not significant correlates of bystander willingness in the full path model. These findings held across participants from the Global North and Global South, suggesting that self-efficacy, an awareness of male privilege, and positive attitudes toward antiviolence work are factors which may support men’s violence preventative actions across broad regional contexts. © 2018 Taylor & Franci

    Examining Men’s Perceptions of GBV Prevention Programming Content

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    As global efforts to engage men in preventing gender-based violence (GBV) continue to grow, understanding male participants’ perceptions of prevention events is needed. Data from a global sample of 319 men who had attended GBV prevention events were used to (a) assess men’s perceptions of what topics were covered, (b) determine whether profiles of these perceptions could be identified, and (c) describe the degree to which content prerception profiles are associated with levels of men’s motivation and confidence related to antiviolence action. Latent class analysis identified four perception profiles of prevention topics. Implications for GBV prevention programming are discussed. © The Author(s) 2018

    Red imported fire ant impacts on the endangered Florida grasshopper sparrow

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    Red imported fire ants (Solenopsis invicta) invaded peninsular Florida more than 30 years ago. Highlands and Polk counties, Florida, were probably first invaded in the late 1960s. Since then, fire ants have continued both to spread and to increase in abundance. Experimental evidence has shown that red imported fire ants may have a detrimental impact on native species, both invertebrate and vertebrate, and that these impacts may be both direct and indirect. This segment of research was designed to determine if fire ants have a negative impact on Florida grasshopper sparrow (Ammodramus savannarumfloridanus) populations at Avon Park Air Force Bombing Range, Florida. The sampling reported herein was conducted during June and October, 1997, and all analyses are restricted to data collected during those periods. As assessed by baits, fire ants were dominant on about half the sites, and absent from others. In particular, OQ Range sites tended to have fewer fire ants present, while Delta Trail sites were more heavily infested, although there were exceptions. June fire ant abundance was strongly negatively correlated with both native ant abundance (r = -0.743, P = 0.006) and native ant species richness (r = -0.730, P = 0.007). October fire ant abundance was strongly negatively correlated with both native ant abundance (r = -0.690, P = 0.013) and native ant species richness (r = -0.736, P = 0.006). The patterns of fire ant abundance as assessed by pitfalls were very similar to those determined from bait sampling. June fire ant abundance was negatively correlated (p < 0.05) with native ant richness, but other June comparisons were not statistically significant (P > 0.05). October fire ant abundance was negatively correlated (P < 0.05) with native ant richness and abundance, but other comparisons were not statistically significant (P > 0.05). There was no significant correlation between overall insect biomass as assessed by light traps and fire ant abundance as assessed by baits or pitfalls. Total biomass varied considerably among the two sample periods because of changes in overall insect abundance during different seasons. There was a negative spatial correspondence between fire ants and native invertebrates. Over most of the intensive study areas, there was a negative spatial relationship between fire ants and the abundance of native invertebrates. Over about 50% of the intensive study areas, there was a negative spatial relationship between fire ants and the abundance of Florida grasshopper sparrows, although the relationship was not as strong as that between fire ants and native invertebrates. Fire ant and native invertebrates were negatively correlated at grasshopper sparrow count locations (r =0.347, P = 0.03). A multiple regression model was fit to the data, using fire ants and native invertebrates as independent variables, and grasshopper sparrow 100-m population estimates (n = 39) as the dependent variable. The influence of fire ants on grasshopper sparrows was negative while the influence of native invertebrates was positive. However, the overall model, while suggestive, was not significant (r = 0.304, P = 0.17). Fire ant abundance was a better (negative) predictor of sparrow populations (P = 0.13) than was invertebrate abundance (P = 0.59). The overall model and influence of fire ants on sparrow populations was suggestive of a negative influence warranting analyses of data for 1998 and 1999. (Document has 93 pages

    Extreme Electron-Phonon Coupling in Boron-based Layered Superconductors

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    The phonon-mode decomposition of the electron-phonon coupling in the MgB2-like system Li_{1-x}BC is explored using first principles calculations. It is found that the high temperature superconductivity of such systems results from extremely strong coupling to only ~2% of the phonon modes. Novel characteristics of E_2g branches include (1) ``mode lambda'' values of 25 and greater compared to a mean of ∌0.4\sim 0.4 for other modes, (2) a precipitous Kohn anomaly, and (3) E_2g phonon linewidths within a factor of ~2 of the frequency itself, indicating impending breakdown of linear electron-phonon theory. This behavior in borne out by recent inelastic x-ray scattering studies of MgB2 by Shukla et al.Comment: 4 two-column pages, 4 figures. Equations simplified. Figure 4 changed. Comparison with new data include

    Heavy Metal, Organochlorine Pesticide and Polychlorinated Biphenyl Contamination in Arctic Ground Squirrels (Spermophilus Parryi) in Northern Alaska

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    Heavy metal and organochlorine (OC) concentrations including organochlorine pesticides and polychlorinated biphenyl congeners (PCBs), were determined in arctic ground squirrels (Spermophilus parryi) from three sites in the Brooks Range of northern Alaska in 1991-93. Heavy metals were present in most squirrel livers collected, with concentrations of trace elements (As, Cd, Hg, Ni, and Pb) averaging below 1 micro g/g wet weight. Hexachlorobenzene (HCB), p,p'-DDE, gamma hexachlorocyclohexane (gamma-HCH), trans-nonachlor, and PCBs 138, 153, and 170 were the most frequently detected OCs in fat and liver. Average concentrations of individual OC analytes were below 20 ng/g wet weight in liver and below 15 ng/g wet weight in fat. Rank correlations indicate that concentrations of heavy metals and of OCs accumulate in concert with one another (As, Cd, Cu, and Zn; PCBs 138, 170, and 180). Although heavy metal and OC concentrations are low relative to other areas and other arctic species, the occurrence of these compounds illustrates the global pervasiveness of persistent organic compounds and the potential for bioaccumulation in the terrestrial arctic food web.De 1991 à 1993, on a mesuré les concentrations en métaux lourds et en organochlorés, y compris des pesticides organochlorés et des congénÚres du diphényle polychloré (PCB), chez le spermophile arctique (Spermophilus parryi) à trois endroits situés dans la chaßne de Brooks de l'Alaska septentrional. On a trouvé des métaux lourds dans la plupart des foies de spermophiles prélevés, avec des concentrations en éléments traces (As, Cd, Hg, Ni et Pb) inférieures en moyenne à 1 ”g/g de poids frais. L'hexachlorobenzÚne (HCB), le p,p'-DDE, l'hexachlorocyclohexane gamma (HCH-gamma), le trans-nonachlore et les PCB 138, 153 et 170 étaient les organochlorés les plus fréquemment détectés dans le tissu adipeux et le foie. Les concentrations moyennes des organochlorés analysés individuellement étaient inférieures à 20 ng/g de poids frais pour le foie et à 15 ng/g de poids frais pour le tissu adipeux. Les corrélations de rang révÚlent que les concentrations en métaux lourds augmentent de concert avec celles en organochlorés (As, Cd, Cu et Zn; PCB 138, 170 et 180). Bien que les concentrations en métaux lourds et en organochlorés soient faibles par rapport à celles d'autres régions et à celles d'autres espÚces arctiques, la présence de ces composés illustre l'omniprésence planétaire de composés organiques persistants et le potentiel pour une accumulation biologique dans le réseau trophique terrestre de l'Arctique

    Simple Fluids with Complex Phase Behavior

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    We find that a system of particles interacting through a simple isotropic potential with a softened core is able to exhibit a rich phase behavior including: a liquid-liquid phase transition in the supercooled phase, as has been suggested for water; a gas-liquid-liquid triple point; a freezing line with anomalous reentrant behavior. The essential ingredient leading to these features resides in that the potential investigated gives origin to two effective core radii.Comment: 7 pages including 3 eps figures + 1 jpeg figur

    "Live” (stained) benthic foraminiferal living depths, stable isotopes, and taxonomy offshore South Georgia, Southern Ocean: implications for calcification depths

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    It is widely held that benthic foraminifera exhibit species-specific calcification depth preferences, with their tests recording sediment pore water chemistry at that depth (i.e. stable isotope and trace metal compositions). This assumed depth habitat-specific pore water chemistry relationship has been used to reconstruct various palaeoenvironmental parameters, such as bottom water oxygenation. However, many deep-water foraminiferal studies show wide intra-species variation in sediment living depth but relatively narrow intra-species variation in stable isotope composition. To investigate this depth habitat- stable isotope relationship on the shelf we analysed depth distribution and stable isotopes of “living” (Rose Bengal stained) benthic foraminifera from two box cores collected on the South Georgia shelf (ranging from 250–300 m water depth). We provide a comprehensive taxonomic analysis of the benthic fauna, comprising 79 taxonomic groupings. The fauna shows close affinities with shelf assemblages from around Antarctica. We find “live” specimens of a number calcareous species from a range of depths in the sediment column. Stable isotope ratios (ή13C and ή18O) were measured on stained specimens of three species, Astrononion echolsi, Cassidulinoides porrectus and Buccella sp. 1, at 1 cm depth intervals within the down-core sediment sequences. In agreement with studies in deep water settings, we find no significant intraspecies variability in either ή13C foram or ή18O foram with sediment living depth on the South Georgia shelf. Our findings add to the growing evidence that infaunal benthic foraminiferal species calcify at a fixed depth. Given the wide range of depths that we find “living” ‘infaunal’ species, we speculate that they may actually calcify predominantly at the sediment-seawater interface, where carbonate ion concentration and organic carbon availability is at a maximum

    Transverse instability and its long-term development for solitary waves of the (2+1)-Boussinesq equation

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    The stability properties of line solitary wave solutions of the (2+1)-dimensional Boussinesq equation with respect to transverse perturbations and their consequences are considered. A geometric condition arising from a multi-symplectic formulation of this equation gives an explicit relation between the parameters for transverse instability when the transverse wavenumber is small. The Evans function is then computed explicitly, giving the eigenvalues for transverse instability for all transverse wavenumbers. To determine the nonlinear and long time implications of transverse instability, numerical simulations are performed using pseudospectral discretization. The numerics confirm the analytic results, and in all cases studied, transverse instability leads to collapse.Comment: 16 pages, 8 figures; submitted to Phys. Rev.

    Angular momenta creation in relativistic electron-positron plasma

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    Creation of angular momentum in a relativistic electron-positron plasma is explored. It is shown that a chain of angular momentum carrying vortices is a robust asymptotic state sustained by the generalized nonlinear Schrodinger equation characteristic to the system. The results may suggest a possible electromagnetic origin of angular momenta when it is applied to the MeV epoch of the early Universe.Comment: 20 pages, 6 figure

    Massless Minimally Coupled Fields in De Sitter Space: O(4)-Symmetric States Versus De Sitter Invariant Vacuum

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    The issue of de Sitter invariance for a massless minimally coupled scalar field is revisited. Formally, it is possible to construct a de Sitter invariant state for this case provided that the zero mode of the field is quantized properly. Here we take the point of view that this state is physically acceptable, in the sense that physical observables can be computed and have a reasonable interpretation. In particular, we use this vacuum to derive a new result: that the squared difference between the field at two points along a geodesic observer's space-time path grows linearly with the observer's proper time for a quantum state that does not break de Sitter invariance. Also, we use the Hadamard formalism to compute the renormalized expectation value of the energy momentum tensor, both in the O(4) invariant states introduced by Allen and Follaci, and in the de Sitter invariant vacuum. We find that the vacuum energy density in the O(4) invariant case is larger than in the de Sitter invariant case.Comment: TUTP-92-1, to appear in Phys. Rev.
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