827 research outputs found

    Lowland tundra plant stoichiometry is somewhat resilient decades following fire despite substantial and sustained shifts in community structure

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    The Arctic is experiencing the greatest increase in average surface temperature globally, which is projected to amplify wildfire frequency and severity. Wildfire alters the biogeochemical characteristics of arctic ecosystems. However, the extent of these changes over time-particularly with regard to plant stoichiometries relative to community structure-is not well documented. Four years after the Yukon-Kuskokwim Delta, Alaska, experienced its largest fire season, aboveground plant and lichen biomass was harvested across a gradient of burn history: unburned ("reference"), 2015 burn ("recent burn"), and 1972 burn ("historic burn") to assess the resilience of tundra plant communities to fire disturbance. Fire reduced aboveground biomass in the recent burn; early recovery was characterized by evergreen shrub and graminoid dominance. In the historic burn, aboveground biomass approached reference conditions despite a sustained reduction of lichen biomass. Although total plant and lichen carbon (C) and nitrogen (N) were reduced immediately following fire, N stocks recovered to a greater degree-reducing community-level C:N. Notably, at the species level, N enrichment was observed only in the recent burn. Yet, community restructuring persisted for decades following fire, reflecting a sustained reduction in N-poor lichens relative to more N-rich vascular plant species

    γZ\gamma Z Pair Production at the Photon Linear Collider

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    γγγZ\gamma\gamma\to\gamma Z scattering at the Photon Linear Collider is considered. Explicit formulas for helicity amplitudes due to WW boson loops are presented. It is shown that the ZγZ\gamma pair production will be easily observable at PLC and separation of the WW loop contribution will be possible at e+ee^+e^- c.m. energy of 300~GeV or higher.Comment: 9 pages of standard LaTeX + 3 PostScript figures (uuencoded and compressed

    Quartic Anomalous Couplings in γγ\gamma\gamma Colliders

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    We study the constraints on the vertices W+WZγW^+W^- Z\gamma, W+WγγW^+W^-\gamma\gamma, and ZZγγZZ\gamma\gamma that can be obtained from triple-gauge-boson production at the next generation of linear e+ee^+e^- colliders operating in the γγ\gamma\gamma mode. We analyze the processes γγW+WV\gamma\gamma \to W^+W^-V (V=ZV=Z, or γ\gamma) and show that these reactions increase the potential of e+ee^+e^- machines to search for anomalous four-gauge-boson interactions.Comment: 15 pages, Latex file using ReVteX, 4 uufiled figures include

    The visible effect of a very heavy magnetic monopole at colliders

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    If a heavy Dirac monopole exists, the light-to-light scattering below the monopole production threshold is enhanced due to strong coupling of monopoles to photons. At the next Linear Collider with electron beam energy 250 GeV this photon pair production could be observable at monopole masses less than 2.5-6.4 TeV in the e+ee^+e^- mode or 3.7-10 TeV in the γγ\gamma\gamma mode, depending on the monopole spin. At the upgraded Tevatron such an effect is expected to be visible at monopole masses below 1-2.5 TeV. The strong dependence on the initial photon polarizations allows to find the monopole spin in experiments at e+ee^+e^- and γγ\gamma\gamma colliders. We consider the ZγZ\gamma production and the 3γ3\gamma production at e+ee^+e^- and pppp or ppˉp\bar{p} colliders via the same monopole loop. The possibility to discover these processes is significantly lower than that of the γγ\gamma\gamma case.Comment: 18 pages, 2 figures, RevTe

    Did female prisoners with mental disorders receive psychiatric treatment before imprisonment?

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    © 2015 Mundt et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.BackgroundThroughout the world, high prevalence rates of mental disorders have been found in prison populations, especially in females. It has been suggested that these populations do not access psychiatric treatment. The aim of this study was to establish rates of psychiatric in- and outpatient treatments prior to imprisonment in female prisoners and to explore reasons for discontinuation of such treatments.Methods150 consecutively admitted female prisoners were interviewed in Berlin, Germany. Socio-demographic characteristics, mental disorders, and previous psychiatric in- and outpatient treatments were assessed by trained researchers. Open questions were used to explore reasons for ending previous psychiatric treatment.ResultsA vast majority of 99 prisoners (66%; 95% CI: 58¿73) of the total sample reported that they had previously been in psychiatric treatment, 80 (53%; 95 CI: 45¿61) in inpatient treatment, 62 (41%; 95 CI: 34¿49) in outpatient treatment and 42 (29%; 21¿39) in both in- and outpatient treatments. All prisoners with psychosis and 72% of the ones with any lifetime mental health disorder had been in previous treatment. The number of inpatient treatments and imprisonments were positively correlated (rho¿=¿0.27; p¿<¿0.01). Inpatient treatment was described as successfully completed by 56% (N¿=¿41) of those having given reasons for ending such treatment, whilst various reasons were reported for prematurely ending outpatient treatments.ConclusionThe data do not support the notion of a general `mental health treatment gap¿ in female prisoners. Although inpatient care is often successfully completed, repeated inpatient treatments are not linked with fewer imprisonments. Improved transition from inpatient to outpatient treatment and services that engage female prisoners to sustained outpatient treatments are needed

    Coming Home: Health Status and Homelessness Risk of Older Pre-release Prisoners

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    Older adults comprise an increasing proportion of the prison and homeless populations. While older age is associated with adverse post-release health events and incarceration is a risk factor for homelessness, the health status and homelessness risk of older pre-release prisoners are unknown. Moreover, most post-release services are geared towards veterans; it is unknown whether the needs of non-veterans differ from those of veterans. To assess health status and risk of homelessness of older pre-release prisoners, and to compare veterans with non-veterans. Cross-sectional study of 360 prisoners (≥55&nbsp;years of age) within 2&nbsp;years of release from prison using data from the 2004 Survey of Inmates in State and Federal Correctional Facilities. Veteran status, health status (based on self-report), and risk of homelessness (homelessness before arrest). Mean age was 61&nbsp;years; 93.8% were men and 56.5% were white. Nearly 40% were veterans, of whom 77.2% reported likely VA service eligibility. Veterans were more likely to be white and to have obtained a high school diploma or GED. Overall, 79.1% reported a medical condition and 13.6% reported a serious mental illness. There was little difference in health status between veterans and non-veterans. Although 1 in 12 prisoners reported a risk factor for homelessness, the risk factors did not differ according to veteran status. Older pre-release prisoners had a high burden of medical and mental illness and were at risk for post-release homelessness regardless of veteran status. Reentry programs linking pre-release older prisoners to medical and psychiatric services and to homelessness prevention programs are needed for both veterans and non-veterans

    Incidence of ANCA-associated vasculitis in a UK mixed ethnicity population

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    Objectives: We aimed to estimate the incidence of ANCA-associated vasculitis in the UK and how this varied by ethnic group. Methods: We identified incident cases of ANCA-associated vasculitis between March 2007 and June 2013 in the Nottingham–Derby urban area from medical records using multiple sources. We derived the denominator population from the 2011 census, and we calculated incidence rate ratios using Poisson regression. Results: Overall, we identified 107 cases of ANCA-associated vasculitis, giving an incidence of 23.1 per million person-years (95% CI: 18.9, 27.9). The incidence among the white population was 25.8 per million person-years (95% CI: 21.0, 31.3) and among the black and minority ethnic (BME) population 8.4 per million person-years (95% CI: 3.1, 18.3). After adjustment for age and sex, the difference between ethnic groups was not statistically significant (incidence rate ratio 0.7, 95% CI: 0.3, 1.5, P = 0.3). Conclusion: Overall, the incidence of ANCA-associated vasculitis was similar to other epidemiological studies. Crude incidence rates were lower in the BME than in the white population, but this was partly explained by the older age profile among the white compared with BME population

    The Higgs - photon - Z boson coupling revisited

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    We analyze the coupling of CP-even and CP-odd Higgs bosons to a photon and a Z boson in extensions of the Standard Model. In particular, we study in detail the effect of charged Higgs bosons in two-Higgs doublet models, and the contribution of SUSY particle loops in the minimal supersymmetric extension of the Standard Model. The Higgs-γZ\gamma Z coupling can be measured in the decay ZγZ \to \gamma+Higgs at e+ee^+e^- colliders running on the Z resonance, or in the reverse process Higgs Zγ\to Z \gamma with the Higgs boson produced at LHC. We show that a measurement of this coupling with a precision at the percent level, which could be the case at future e+ee^+e^- colliders, would allow to distinguish between the lightest SUSY and standard Higgs bosons in large areas of the parameter space.Comment: 18 pages LaTex + 7 figures (ps). Typo corrected in eq.(5
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