5,874 research outputs found

    Flow alteration-ecology relationships in Ozark Highland streams: Consequences for fish, crayfish and macroinvertebrate assemblages

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    We examined flowalteration-ecology relationships in benthic macroinvertebrate, fish, and crayfish assemblages in Ozark Highland streams, USA, over two years with contrasting environmental conditions, a drought year (2012) and a flood year (2013). We hypothesized that: 1) there would be temporal variation in flow alteration-ecology relationships between the two years, 2) flow alteration-ecology relationshipswould be stronger during the drought year vs the flood year, and 3) fish assemblages would show the strongest relationships with flow alteration. We used a quantitative richest-targeted habitat (RTH) method and a qualitative multihabitat (QMH) method to collect macroinvertebrates at 16 USGS gaged sites during both years. We used backpack electrofishing to sample fish and crayfish at 17 sites in 2012 and 11 sites in 2013.Weused redundancy analysis to relate biological response metrics, including richness, diversity, density, and community-based metrics, to flow alteration.We found temporal variation in flow alteration-ecology relationships for all taxa, and that relationships differed greatly between assemblages. We found relationships were stronger for macroinvertebrates during the drought year but not for other assemblages, and that fish assemblage relationships were not stronger than the invertebrate taxa. Magnitude of average flow, frequency of high flow, magnitude of high flow, and duration of high flow were the most important categories of flow alteration metrics across taxa. Alteration of high and average flows was more important than alteration of low flows. Of 32 important flow alteration metrics across years and assemblages, 19 were significantly altered relative to expected values. Ecological responses differed substantially between drought and flood years, and this is likely to be exacerbated with predicted climate change scenarios. Differences in flow alteration-ecology relationships among taxonomic groups and temporal variation in relationships illustrate that a complex suite of variables should be considered for effective conservation of stream communities related to flow alteration

    The collective quantization of three-flavored Skyrmions revisited

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    A self-consistent large NcN_c approach is developed for the collective quantization of SU(3) flavor hedgehog solitons, such as the Skyrmion. The key to this analysis is the determination of all of the zero modes associated with small fluctuations around the hedgehog. These are used in the conventional way to construct collective coordinates. This approach differs from previous work in that it does not implicitly assume that each static zero mode is associated with a dynamical zero mode. It is demonstrated explicitly in the context of the Skyrmion that there are fewer dynamical zero modes than static ones due to the Witten-Wess-Zumino term in the action. Group-theoretic methods are employed to identify the physical states resulting from canonical quantization of the collectively rotating soliton. The collective states fall into representations of SU(3) flavor labeled by (p,q)(p,q) and are given by (2J,Nc2J)(2J, \frac{Nc}{2} -J) where J=1/2,3/2,...J={1/2},{3/2},... is the spin of the collective state. States with strangeness S>0S > 0 do not arise as collective states from this procedure; thus the θ+\theta^{+} (pentaquark) resonance does not arise as a collective excitation in models of this type.Comment: 12 pages; uses package "youngtab

    Casual Mediation Analyses with Structural Mean Models

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    We represent a linear structural mean model (SMM)approach for analyzing mediation of a randomized baseline intervention\u27s effect on a univariate follow-up outcome. Unlike standard mediation analyses, our approach does not assume that the mediating factor is randomly assigned to individuals (i.e., sequential ignorability). Hence, a comparison of the results of the proposed and standard approaches in with respect to mediation offers a sensitivity analyses of the sequential ignorability assumption. The G-estimation procedure for the proposed SMM represents an extension of the work on direct effects of randomized treatment effects for survival outcomes by Robins and Greenland (1994) (Section 5.0 and Appendix B) and on treatment non-adherence for continuous outcomes by TenHave et al. (2004). Simulations show good estimation and confidence interval performance under unmeasured confounding relative mediation approach. Sensitivity analyses of the sequential ignorability assumption comparing the results of the two approaches are presented in the context of two suicide/depression treatment studies

    Mindfulness meditation targets transdiagnostic symptoms implicated in stress-related disorders: Understanding relationships between changes in mindfulness, sleep quality, and physical symptoms

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    Mindfulness-Based Stress Reduction (MBSR) is an 8-week meditation program known to improve anxiety, depression, and psychological well-being. Other health-related effects, such as sleep quality, are less well established, as are the psychological processes associated with therapeutic change. This prospective, observational study (n=213) aimed to determine whether perseverative cognition, indicated by rumination and intrusive thoughts, and emotion regulation, measured by avoidance, thought suppression, emotion suppression, and cognitive reappraisal, partly accounted for the hypothesized relationship between changes in mindfulness and two health-related outcomes: sleep quality and stress-related physical symptoms. As expected, increased mindfulness following the MBSR program was directly correlated with decreased sleep disturbance (r=-0.21, p=0.004) and decreased stress-related physical symptoms (r=-0.38, p<0.001). Partial correlations revealed that pre-post changes in rumination, unwanted intrusive thoughts, thought suppression, experiential avoidance, emotion suppression, and cognitive reappraisal each uniquely accounted for up to 32% of the correlation between the change in mindfulness and change in sleep disturbance and up to 30% of the correlation between the change in mindfulness and change in stress-related physical symptoms. Results suggest that the stress-reducing effects of MBSR are due, in part, to improvements in perseverative cognition and emotion regulation, two “transdiagnostic” mental processes that cut across stress-related disorders

    The Role and Responsibility of Prosecutors

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    In this panel, the discussion moves form the abstract to the very specific. Moderator Thomas Metzloff, professor of law at Duke University School of Law, asks the panelists to analyze the actions leading to the disbarment of former Durham District Attorney Mike Nifong. The speakers, all current or former prosecutors, detail personal experiences dealing with reporters, and discuss the guidelines, written and unwritten, which govern such interaction. Questions/themes/discussion topics The press as a tool to communicate with the public The press as a watchdog Training of young prosecutors in press interaction The effect of the U.S. Supreme Court\u27s 2002 decision in Minnesota v. White on regulating attorney speech Strategic advantages (or lack thereof) to press interaction To what degree can prosecutors control leaks from their office or, more problematically, from the local police department? Public statements as jury pool pollutant

    A new reference genome assembly for the microcrustacean Daphnia pulex

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    Comparing genomes of closely related genotypes from populations with distinct demographic histories can help reveal the impact of effective population size on genome evolution. For this purpose, we present a high quality genome assembly of Daphnia pulex (PA42), and compare this with the first sequenced genome of this species (TCO), which was derived from an isolate from a population with >90% reduction in nucleotide diversity. PA42 has numerous similarities to TCO at the gene level, with an average amino acid sequence identity of 98.8 and >60% of orthologous proteins identical. Nonetheless, there is a highly elevated number of genes in the TCO genome annotation, with similar to 7000 excess genes appearing to be false positives. This view is supported by the high GC content, lack of introns, and short length of these suspicious gene annotations. Consistent with the view that reduced effective population size can facilitate the accumulation of slightly deleterious genomic features, we observe more proliferation of transposable elements (TEs) and a higher frequency of gained introns in the TCO genome

    Is there a shared social work signature pedagogy cross-nationally? : Using a case study methodology to explore signature pedagogy in England, Israel, Finland, Spain and Sweden

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    While there is an international definition of social work as a profession, little is known about whether there is also a shared pedagogy in social work cross-nationally. To our knowledge, this paper is the first empirical study which aims to fill this gap by applying the concept of signature pedagogy in social work education to explore the commonality of social work pedagogy across countries. The study uses a multi-site case study (six universities in five European countries) through applying a 'critical teacher-researcher' approach in generating the data, followed by a two-phased thematic analysis. The study evidenced a shared principle of social work pedagogy which nurtures social work student to think and perform like a social worker and develop the professional self through developing relationships and dialogue, professional practice, group work, self-reflection and critical thinking. It is argued from, this exploratory study, that even between countries which have different welfare ideology as well as social work history and education systems, there is some common ground in social work pedagogy where one can learn from another through the use of 'teacher as researcher' methodologically.Peer reviewe

    Decreased symptoms of depression after mindfulness-based stress reduction: potential moderating effects of religiosity, spirituality, trait mindfulness, sex, and age

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    Objective: mindfulness-based stress reduction (MBSR) is a secular meditation training program that reduces depressive symptoms. Little is known, however, about the degree to which a participant's spiritual and religious background, or other demographic characteristics associated with risk for depression, may affect the effectiveness of MBSR. Therefore, this study tested whether individual differences in religiosity, spirituality, motivation for spiritual growth, trait mindfulness, sex, and age affect MBSR effectiveness.Methods: as part of an open trial, multiple regression was used to analyze variation in depressive symptom outcomes among 322 adults who enrolled in an 8-week, community-based MBSR program.Results: as hypothesized, depressive symptom severity decreased significantly in the full study sample (d=0.57; p&lt;0.01). After adjustment for baseline symptom severity, moderation analyses revealed no significant differences in the change in depressive symptoms following MBSR as a function of spirituality, religiosity, trait mindfulness, or demographic variables. Paired t tests found consistent, statistically significant (p&lt;0.01) reductions in depressive symptoms across all subgroups by religious affiliation, intention for spiritual growth, sex, and baseline symptom severity. After adjustment for baseline symptom scores, age, sex, and religious affiliation, a significant proportion of variance in post-MBSR depressive symptoms was uniquely explained by changes in both spirituality (?=?0.15; p=0.006) and mindfulness (?=?0.17; p&lt;0.001).Conclusions: these findings suggest that MBSR, a secular meditation training program, is associated with improved depressive symptoms regardless of affiliation with a religion, sense of spirituality, trait level of mindfulness before MBSR training, sex, or age. Increases in both mindfulness and daily spiritual experiences uniquely explained improvement in depressive symptom

    Energy Index For Aircraft Maneuvers

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    Method and system for analyzing, separately or in combination, kinetic energy and potential energy and/or their time derivatives, measured or estimated or computed, for an aircraft in approach phase or in takeoff phase, to determine if the aircraft is or will be put in an anomalous configuration in order to join a stable approach path or takeoff path. A 3 reference value of kinetic energy andor potential energy (or time derivatives thereof) is provided, and a comparison index .for the estimated energy and reference energy is computed and compared with a normal range of index values for a corresponding aircraft maneuver. If the computed energy index lies outside the normal index range, this phase of the aircraft is identified as anomalous, non-normal or potentially unstable
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