1,334 research outputs found

    Deceptive Practices: The Issue of “Bullying-to-Suicide” in the U.S. Army

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    poster abstractThe United States Department of Defense reported that 182 active–duty Army soldiers took their own lives in 2012. Several key factors contributing to this high rate of suicide, such as Post-traumatic Stress Syndrome (PTSD) and depression and Traumatic Brain Injury (TBI) have been intensely researched. This poster represents exploratory research on the issue of suicide in the military; paying particular attention to the practice of informal negative sanctions. Data on this issue was obtained from numerous articles, reports and qualitative interviews conducted with active-duty Army personnel and recently separated Army veterans. This study not only describes war’s impact on human’s mental health and the hidden realities of Army life. It additionally assesses how interpersonal procedures operate on different ranges

    Designing pseudocubic perovskites with enhanced nanoscale polarization

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    A crystal-chemical framework has been proposed for the design of pseudocubic perovskites with nanoscale ferroelectric order, and its applicability has been demonstrated using a series of represen- tative solid solutions that combined ferroelectric (K 0.5 Bi 0.5 TiO 3 , BaTiO 3 , and PbTiO 3 ) and antifer- roelectric (Nd-substituted BiFeO 3 ) end members. The pseudocubic structures obtained in these systems exhibited distortions that were coherent on a scale ranging from sub-nanometer to tens of nanometers, but, in all cases, the macroscopic distortion remained unresolvable even if using high- resolution X-ray powder diffraction. Different coherence lengths for the local atomic displacements account for the distinctly different dielectric, ferroelectric, and electromechanical properties exhib- ited by the samples. The guidelines identified provide a rationale for chemically tuning the coher- ence length to obtain the desired functional response

    Kaneohe Bay Sewage Diversion Experiment: Perspectives on Ecosystem Responses to Nutritional Perturbation

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    Kaneohe Bay, Hawaii, received increasing amounts of sewage from the 1950s through 1977. Most sewage was diverted from the bay in 1977 and early 1978. This investigation, begun in January 1976 and continued through August 1979, described the bay over that period, with particular reference to the responses of the ecosystem to sewage diversion. The sewage was a nutritional subsidy. All of the inorganic nitrogen and most of the inorganic phosphorus introduced into the ecosystem were taken up biologically before being advected from the bay. The major uptake was by phytoplankton, and the internal water-column cycle between dissolved nutrients, phytoplankton, zooplankton, microheterotrophs, and detritus supported a rate of productivity far exceeding the rate of nutrient loading. These water-column particles were partly washed out of the ecosystem and partly sedimented and became available to the benthos. The primary benthic response to nutrient loading was a large buildup of detritivorous heterotrophic biomass. Cycling of nutrients among heterotrophs, autotrophs, detritus, and inorganic nutrients was important. With sewage diversion, the biomass of both plankton and benthos decreased rapidly. Benthic biological composition has not yet returned to presewage conditions, partly because some key organisms are long-lived and partly because the bay substratum has been perturbed by both the sewage and other human influences

    C, S, Zn and Cu abundances in planet-harbouring stars

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    We present a detailed and uniform study of C, S, Zn and Cu abundances in a large set of planet host stars, as well as in a homogeneous comparison sample of solar-type dwarfs with no known planetary-mass companions. Carbon abundances were derived by {EW} measurement of two C I optical lines, while spectral syntheses were performed for S, Zn and Cu. We investigated possible differences in the behaviours of the volatiles C, S and Zn and in the refractory Cu in targets with and without known planets in order to check possible anomalies due to the presence of planets. We found that the abundance distributions in stars with exoplanets are the high [Fe/H] extensions of the trends traced by the comparison sample. All volatile elements we studied show [X/Fe] trends decreasing with [Fe/H] in the metallicity range -0.8<[Fe/H]<0.5, with significantly negative slopes of -0.39+-0.04 and -0.35+-0.04 for C and S, respectively. A comparison of our abundances with those available in the literature shows good agreement in most cases.Comment: 28 pages, 13 figures, accepted for publication in A&

    Nanoscale polar heterogeneities and branching Bi-displacement directions in K0.5Bi0.5TiO3

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    K0.5Bi0.5TiO3 (KBT)—one of the few perovskite-like ferroelectric compounds with room-temperature tetragonal symmetry—differs from other members of its family (BaTiO3 and PbTiO3) by the presence of a disordered mixture of K and Bi on cuboctahedral sites. This disorder is expected to affect local atomic displacements and their response to an applied electric field. We have derived nanoscale atomistic models of KBT by refining atomic coordinates to simultaneously fit neutron/X-ray total scattering and extended X-ray absorption fine-structure data. Both Bi and Ti ions were found to be offset relative to their respective oxygen cages in the high-temperature cubic phase; in contrast, the coordination environment of K remained relatively undistorted. In the cubic structure, Bi displacements prefer the ⟹100⟩ directions and the probability density distribution of Bi features six well-separated sites; a similar preference exists for the much smaller Ti displacements, although the split sites for Ti could not be resolved. The cation displacements are correlated, yielding polar nanoregions, whereas on average, the structure appears as cubic. The cubic ↔ tetragonal phase transition involves both order/disorder and displacive mechanisms. A qualitative change in the form of the Bi probability density distribution occurs in the tetragonal phase on cooling to room temperature because Bi displacements “branch off” to ⟹111⟩ directions. This change, which preserves the average symmetry, is accompanied by the development of nanoscale polar heterogeneities that exhibit significant deviations of their polarization vectors from the average polar axis

    Differential Impact of Serial Measurement of Nonplatelet Thromboxane Generation on Long-Term Outcome After Cardiac Surgery.

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    BACKGROUND: Systemic thromboxane generation, not suppressible by standard aspirin therapy and likely arising from nonplatelet sources, increases the risk of atherothrombosis and death in patients with cardiovascular disease. In the RIGOR (Reduction in Graft Occlusion Rates) study, greater nonplatelet thromboxane generation occurred early compared with late after coronary artery bypass graft surgery, although only the latter correlated with graft failure. We hypothesize that a similar differential association exists between nonplatelet thromboxane generation and long-term clinical outcome. METHODS AND RESULTS: Five-year outcome data were analyzed for 290 RIGOR subjects taking aspirin with suppressed platelet thromboxane generation. Multivariable modeling was performed to define the relative predictive value of the urine thromboxane metabolite, 11-dehydrothromboxane B CONCLUSIONS: Long-term nonplatelet thromboxane generation after coronary artery bypass graft surgery is a novel risk factor for 5-year adverse outcome, including death. In contrast, nonplatelet thromboxane generation in the early postoperative period appears to be driven predominantly by inflammation and did not independently predict long-term clinical outcome

    A Qualitative Analysis of Women's Short Accounts of Labour and Birth in a Western Australian Public Tertiary Hospital

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    This paper reports the findings of the postnatal qualitative arm of a larger study,which investigated women's prenatal and postnatal levels of childbirth fear. Women's expectations and experiences of labour and birth in a Western Australian public tertiary hospital were identified following thematic analysis of short written accounts from 141 participants who had given birth in the previous 6 to 14 weeks. Four major categories emerged to describe features and mediating factors in the trajectory of childbirth and the early puerperium "Anticipating Labour and Birth", "Labour and birth Depicted", "Mediating Factors and their consequences" and "Evaluating, Resolving, and Looking Ahead" portray women's comparative reflections on expectations and realities of birth, on mediating influences, and on moving on from their experience. These findings will provide maternity care professionals with insight into the personal and environmental features of the childbirth setting which colours women's recollections. Being aware of what women value during labour and birth will reinforce the need for professionals to provide care using a mindful approach that considers the potential psychological, emotional and behavioural implications of events

    Searching for the signatures of terrestial planets in solar analogs

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    We present a fully differential chemical abundance analysis using very high-resolution (R >~ 85,000) and very high signal-to-noise (S/N~800 on average) HARPS and UVES spectra of 7 solar twins and 95 solar analogs, 24 are planet hosts and 71 are stars without detected planets. The whole sample of solar analogs provide very accurate Galactic chemical evolution trends in the metalliciy range -0.3<[Fe/H]<0.5. Solar twins with and without planets show similar mean abundance ratios. We have also analysed a sub-sample of 28 solar analogs, 14 planet hosts and 14 stars without known planets, with spectra at S/N~850 on average, in the metallicity range 0.14<[Fe/H]<0.36 and find the same abundance pattern for both samples of stars with and without planets. This result does not depend on either the planet mass, from 7 Earth masses to 17.4 Jupiter masses, or the orbital period of the planets, from 3 to 4300 days. In addition, we have derived the slope of the abundance ratios as a function of the condensation temperature for each star and again find similar distributions of the slopes for both stars with and without planets. In particular, the peaks of these two distributions are placed at a similar value but with opposite sign as that expected from a possible signature of terrestial planets. In particular, two of the planetary systems in this sample, containing each of them a Super-Earth like planet, show slope values very close to these peaks which may suggest that these abundance patterns are not related to the presence of terrestial planets.Comment: Accepted for publication in The Astrophysical Journa

    Cymantrene–Triazole "Click" Products: Structural Characterization and Electrochemical Properties

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    We report the first known examples of triazole-derivatized cymantrene complexes (η5-[4-substituted triazol-1-yl]cyclopentadienyl)tricarbonylmanganese(I), obtained via a “click” chemical synthesis, bearing a phenyl, 3-aminophenyl, or 4-aminophenyl moiety at the 4-position of the triazole ring. Structural characterization data using multinuclear NMR, UV–vis, ATR-IR, and mass spectrometric methods are provided, as well as crystallographic data for (η5-[4-phenyltriazol-1-yl]cyclopentadienyl)tricarbonylmanganese(I) and (η5-[4-(3-aminophenyl)triazol-1-yl]cyclopentadienyl)tricarbonylmanganese(I). Cyclic voltammetric characterization of the redox behavior of each of the three cymantrene–triazole complexes is presented together with digital simulations, in situ infrared spectroelectrochemistry, and DFT calculations to extract the associated kinetic and thermodynamic parameters. The trypanocidal activity of each cymantrene–triazole complex is also examined, and these complexes are found to be more active than cymantrene alone
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