473 research outputs found

    Advancing estuarine ecological forecasts: seasonal hypoxia in Chesapeake Bay

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    Ecological forecasts are quantitative tools that can guide ecosystem management. The coemergence of extensive environmental monitoring and quantitative frameworks allows for widespread development and continued improvement of ecological forecasting systems. We use a relatively simple estuarine hypoxia model to demonstrate advances in addressing some of the most critical challenges and opportunities of contemporary ecological forecasting, including predictive accuracy, uncertainty characterization, and management relevance. We explore the impacts of different combinations of forecast metrics, drivers, and driver time windows on predictive performance. We also incorporate multiple sets of state-variable observations from different sources and separately quantify model prediction error and measurement uncertainty through a flexible Bayesian hierarchical framework. Results illustrate the benefits of (1) adopting forecast metrics and drivers that strike an optimal balance between predictability and relevance to management, (2) incorporating multiple data sources in the calibration data set to separate and propagate different sources of uncertainty, and (3) using the model in scenario mode to probabilistically evaluate the effects of alternative management decisions on future ecosystem state. In the Chesapeake Bay, the subject of this case study, we find that average summer or total annual hypoxia metrics are more predictable than monthly metrics and that measurement error represents an important source of uncertainty. Application of the model in scenario mode suggests that absent watershed management actions over the past decades, long-term average hypoxia would have increased by 7% compared to 1985. Conversely, the model projects that if management goals currently in place to restore the Bay are met, long-term average hypoxia would eventually decrease by 32% with respect to the mid- 1980

    Density-functional calculation of ionization energies of current-carrying atomic states

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    Current-density-functional theory is used to calculate ionization energies of current-carrying atomic states. A perturbative approximation to full current-density-functional theory is implemented for the first time, and found to be numerically feasible. Different parametrizations for the current-dependence of the density functional are critically compared. Orbital currents in open-shell atoms turn out to produce a small shift in the ionization energies. We find that modern density functionals have reached an accuracy at which small current-related terms appearing in open-shell configurations are not negligible anymore compared to the remaining difference to experiment.Comment: 7 pages, 2 tables, accepted by Phys. Rev.

    Magnetic fields in cosmic particle acceleration sources

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    We review here some magnetic phenomena in astrophysical particle accelerators associated with collisionless shocks in supernova remnants, radio galaxies and clusters of galaxies. A specific feature is that the accelerated particles can play an important role in magnetic field evolution in the objects. We discuss a number of CR-driven, magnetic field amplification processes that are likely to operate when diffusive shock acceleration (DSA) becomes efficient and nonlinear. The turbulent magnetic fields produced by these processes determine the maximum energies of accelerated particles and result in specific features in the observed photon radiation of the sources. Equally important, magnetic field amplification by the CR currents and pressure anisotropies may affect the shocked gas temperatures and compression, both in the shock precursor and in the downstream flow, if the shock is an efficient CR accelerator. Strong fluctuations of the magnetic field on scales above the radiation formation length in the shock vicinity result in intermittent structures observable in synchrotron emission images. Resonant and non-resonant CR streaming instabilities in the shock precursor can generate mesoscale magnetic fields with scale-sizes comparable to supernova remnants and even superbubbles. This opens the possibility that magnetic fields in the earliest galaxies were produced by the first generation Population III supernova remnants and by clustered supernovae in star forming regions.Comment: 30 pages, Space Science Review

    Quantum geometry and gravitational entropy

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    Most quantum states have wavefunctions that are widely spread over the accessible Hilbert space and hence do not have a good description in terms of a single classical geometry. In order to understand when geometric descriptions are possible, we exploit the AdS/CFT correspondence in the half-BPS sector of asymptotically AdS_5 x S^5 universes. In this sector we devise a "coarse-grained metric operator" whose eigenstates are well described by a single spacetime topology and geometry. We show that such half-BPS universes have a non-vanishing entropy if and only if the metric is singular, and that the entropy arises from coarse-graining the geometry. Finally, we use our entropy formula to find the most entropic spacetimes with fixed asymptotic moments beyond the global charges.Comment: 29 pages, 2 figures; references adde

    Hubungan Antara Lama Paparan dengan Kapasitas Paru Tenaga Kerja Industri Mebel di CV. Sinar Mandiri Kota Bitung

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    The human lungs as an instrument of pulmonary ventilation in respiratory system in the human body’s. lungs function may decrease due to strikes in the process of physiological mechanisms, one of which is caused by exposure to dust. The continuosly dust exposure can cause problems in the lungs, it also cause chronic lung disease. The aim of research was know the relationship between the long duration of the exposure and lung capacity of workers in the furniture industry at CV. Sinar Mandiri Bitung City. This research was an analytic survey, with a cross-sectional approach. Sample of study was the workers of production, which amounts of 30 respondents and it was a population total study. The data were collected by interviews to know the characteristics of respondents and the measurement of workers lung capacity by using spirometer (peak flow meter). Data was analyzed with Fisher’s Exact Test and using program SPSS version 17.0.The result showed that of 30 respondents who have been checked there are 30 percets who have abnormal FEV1 values or the category of disability. According to the results of statistical test, the probability value was 1,000 (p>0,05).That there was no significant relationship between the long duration of exposure and lung capacity of workers. Recommendation to the chief of company, there was needed monitoring of workers physical condition and working environment. There also needed a prevention way by using mask, as well as needed a supervision and guidance to the companies about occupational health and safety by related department. ABSTRAKParu-paru sebagai alat ventilasi dalam sistem pernafasan bagi tubuh, fungsi kerja paru dapat menurun akibat adanya gangguan pada proses mekanisme faal yang salah satunya disebabkan oleh pemaparan debu. Pemaparan debu yang secara terus-menerus selain dapat menimbulkan gangguan fungsi paru juga dapat menyebabkan terjadinya penyakit paru kronik. Penelitian ini bertujuan untuk mengetahui hubungan antara lama paparan dengan kapasitas paru pekerja industri mebel di CV. Sinar Mandiri Kota Bitung.Penelitian ini merupakan penelitian yang bersifat survei analitik, dengan pendekatan cross sectional. Sampel penelitian adalah pekerja di bagian produksi yang berjumlah 30 orang dan merupakan studi total populasi. Pengumpulan data dilakukan dengan wawancara untuk mengetahui karakteristik responden dan pengukuran kapasitas paru pekerja dengan alat spirometer. Analisis data dilakukan dengan Fisher’s Exact Test dan menggunakan bantuan SPSS versi 17.0. Hasil penelitian menunjukkan bahwa dari 30 responden yang diperiksa terdapat 30% yang mempunyai nilai FEV1 tidak normal atau dikategorikan mengalami gangguan. Berdasarkan hasil uji statistik, nilai probabilitas sebesar 1,000 (p > 0,05)Tidak terdapat hubungan yang bermakna antara lama paparan dengan kapasitas paru pekerja. Saran untuk pimpinan perusahaan perlu dilakukan pemantauan kondisi fisik pekerja dan lingkungan kerja, perlu dilakukan upaya pencegahan dengan penggunaan masker, serta perlu dilakukan pengawasan dan pembinaan terhadap perusahaan mengenai kesehatan dan keselamatan kerja oleh dinas terkait

    Increased soluble IL-7 receptor concentrations associate with improved IL-7 therapy outcomes in SIV-infected ART-treated Rhesus macaques

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    The use of interleukin-7 (IL-7) as an immunorestorative therapeutic has proven effective in HIV infection, cancer and bone marrow transplantation. Mediating its activity through membrane-bound IL-7 receptor α (mCD127), IL-7 therapy increases T-cell numbers and survival. A soluble form, sCD127, is found in plasma, and we have previously identified increased plasma sCD127 concentrations in HIV infection. Furthermore, patients with high sCD127 exhibited the best viral control, implicating a role for IL-7 or sCD127 directly in improved viro-logic/immunologic outcomes. The role of the cytokine IL-7 in elevating sCD127 levels was addressed here through assessment of retrospective samples obtained from SIV-infected antiretroviral (ART)-treated Rhesus macaques. IL-7 was administered in clustered weekly doses, allowing for an assessment prior, during and following IL-7 administration. The levels of sCD127 remained relatively unchanged during both early SIV infection and following initiation of ART. However, treatment with IL-7 increased sCD127 concentrations in most animals, transiently or persistently, paralleling increased T-cell numbers, correlating significantly with CD8+ T-cell levels. In addition, proliferating CD4+ or CD8+ T-cells (measured by Ki67) increased in association with elevated sCD127 concentrations. Finally, a high concentration of sCD127 in IL7-treated animals was associated with increased retention of T-cells (measured by BrDU). In addition, a lack, or loss of viral control was associated with more pronounced and frequent elevations in plasma sCD127 concentrations with IL-7 therapy. In summary, plasma sCD127 levels in SIV-infected ART-treated macaques was associated with therapeutic IL-7 administration, with higher sCD127 levels in macaques demonstrating the best T-cell responses. Thi

    The loss of a fellow service member: Complicated grief in postâ 9/11 service members and veterans with combatâ related posttraumatic stress disorder

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    Bereavement is a potent and highly prevalent stressor among service members and veterans. However, the psychological consequences of bereavement, including complicated grief (CG), have been minimally examined. Loss was assessed in 204 postâ 9/11, when service members and veterans with combatâ related posttraumatic stress disorder (PTSD) took part in a multicenter treatment study. Those who reported the loss of an important person completed the inventory of complicated grief (ICG; nâ =â 160). Over three quarters (79.41%) of the sample reported an important lifetime loss, with close to half (47.06%) reporting the loss of a fellow service member (FSM). The prevalence of CG was 24.75% overall, and nearly one third (31.25%) among the bereaved. CG was more prevalent among veterans who lost a fellow service member (FSM) (41.05%, nâ =â 39) compared to those bereaved who did not (16.92%, nâ =â 11; ORâ =â 3.41, 95% CI: 1.59, 7.36). CG was associated with significantly greater PTSD severity, functional impairment, traumaâ related guilt, and lifetime suicide attempts. Complicated grief was prevalent and associated with adverse psychosocial outcomes in veterans and service members with combatâ related PTSD. Clinicians working with this population should inquire about bereavement, including loss of a FSM, and screen for CG. Additional research examining CG in this population is needed.The loss of a fellow service member occurs commonly and is associated with complicated grief (CG) amongst service members and veterans with combatâ related posttraumatic stress disorder (PTSD). The presence of CG in this study was associated with more severe PTSD, guilt, and lifetime suicide attempts, as well as poorer functioning.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139942/1/jnr24094_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139942/2/jnr24094.pd

    Mutually catalytic branching in the plane: Infinite measure states

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    A two-type infinite-measure-valued population in R2 is constructed which undergoes diffusion and branching. The system is interactive in that the branching rate of each type is proportional to the local density of the other type. For a collision rate sufficiently small compared with the diffusion rate, the model is constructed as a pair of infinite-measure-valued processes which satisfy a martingale problem involving the collision local time of the solutions. The processes are shown to have densities at fixed times which live on disjoint sets and explode as they approach the interface of the two populations. In the long-term limit (in law), local extinction of one type is shown. Moreover the surviving population is uniform with random intensity. The process constructed is a rescaled limit of the corresponding Z 2-lattice model studied by Dawson and Perkins (1998) and resolves the large scale mass-time-space behavior of that model under critical scaling. This part of a trilogy extends results from the finite-measure-valued case, whereas uniqueness questions are again deferred to the third part

    Amblyomma imitator Ticks as Vectors of Rickettsia rickettsii, Mexico

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    Real-time PCR of Amblyomma imitator tick egg masses obtained in Nuevo Leon State, Mexico, identified a Rickettsia species. Sequence analyses of 17-kD common antigen and outer membrane protein A and B gene fragments showed to it to be R. rickettsii, which suggested a potential new vector for this bacterium
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