2,403 research outputs found

    A fluid flow perspective on the diagenesis of Te Aute limestones

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    Pliocene cool-water, bioclastic Te Aute limestones in East Coast Basin, New Zealand, accumulated either in shelfal shoal areas or about structurally shallow growth fold structures in the tectonically active accretionary forearc prism. Up to five stages of carbonate cementation are recognised, based on cement sequence-stratigraphic concepts, that formed on the seafloor during exposure of the limestones before burial, during burial, uplift, and deformation. Two principal fluid types are identified--topography-driven meteoric fluids and compaction-driven fluids. We have developed conceptual and quantitative models that attempt to relate the physical characteristics of fluid flow to the cement paragenesis. In particular, we have simulated the effects of uplift of the axial ranges bordering East Coast Basin in terms of the degree of penetration of a meteoric wedge into the basin. The dynamics of meteoric flow changed dramatically during uplift over the last 2 m.y. such that the modelled extent of the meteoric wedge is at least 40 km across the basin, and the penetration depth 1500 m or more corresponding with measured freshwater intersections in some oil wells. Cement-fluid relationships include: (1) true marine cements that precipitated in areas remote from shallow freshwater lenses; (2) pre-compaction cements that formed in shallow freshwater lenses beneath limestone "islands"; (3) post-compaction cements derived from compaction-driven flow during burial; (4) early uplift-related fracture-fill cements formed during deformation of the accretionary prism and uplift of the axial ranges; and (5) late uplift-related cements associated with uplift into a shallow meteoric regime

    Management regime and habitat response influence abundance of regal fritillary (Speyeria idalia) in tallgrass prairie

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    The \u3e2,570,000-ha Flint Hills ecoregion of Kansas, USA, harbors the largest remaining contiguous tract of tallgrass prairie in North America, a unique system, as the remainder of North America’s tallgrass prairie has succumbed to development and conversion. Consequently, the loss and degradation of tallgrass prairie has reduced populations of many North American prairie-obligate species including the regal fritillary (Speyeria idalia) butterfly. Population abundance and occupied range of regal fritillary have declined \u3e99%, restricting many populations to isolated, remnant patches of tallgrass prairie. Such extensive decline has resulted in consideration of the regal fritillary for protection under the Endangered Species Act. Although it is widely accepted that management practices such as fire, grazing, and haying are necessary to maintain prairie ecosystems, reported responses by regal fritillary to these management regimes have been ambiguous.We tested effects of prescribed fire across short, moderate, and long fire-return intervals as well as grazing and haying management treatments on regal fritillary density. We also tested the relative influence of habitat characteristics created by these management regimes by measuring density of an obligate host plant (Viola spp.) and canopy cover of woody vegetation, grasses, forbs/ferns, bare ground, and litter. We found density was at least 1.6 times greater in sites burned with a moderate fire-return interval vs. sites burned with short and long fire-return intervals. Overall management regardless of fire-return interval did not have an effect on density. Percent cover of grass had the strongest positive association, while percent cover of woody vegetation had the greatest negative effect on density. Our results indicate that patch-burning is a viable and perhaps even ideal management strategy for regal fritillary in tallgrass prairie landscapes. Additionally, these results elucidate the importance of fire, particularly when applied at moderate-return intervals to regal fritillary, and corroborate a growing suite of studies that suggest fire is perhaps not as detrimental to populations of regal fritillary as previously believed

    What are the barriers and facilitators to implementing Collaborative Care for depression? A systematic review.

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    Background: Collaborative Care is an evidence-based approach to the management of depression within primary care services recommended within NICE Guidance. However, uptake within the UK has been limited. This review aims to investigate the barriers and facilitators to implementing Collaborative Care. Methods: A systematic review of the literature was undertaken to uncover what barriers and facilitators have been reported by previous research into Collaborative Care for depression in primary care. Results: The review identified barriers and facilitators to successful implementation of Collaborative Care for depression in 18 studies across a range of settings. A framework analysis was applied using the Collaborative Care definition. The most commonly reported barriers related to the multi-professional approach, such as staff and organisational attitudes to integration, and poor inter-professional communication. Facilitators to successful implementation particularly focussed on improving inter-professional communication through standardised care pathways and case managers with clear role boundaries and key underpinning personal qualities. Limitations: Not all papers were independent title and abstract screened by multiple reviewers thus limiting the reliability of the selected studies. There are many different frameworks for assessing the quality of qualitative research and little consensus as to which is most appropriate in what circumstances. The use of a quality threshold led to the exclusion of six papers that could have included further information on barriers and facilitators. 3 Conclusions: Although the evidence base for Collaborative Care is strong, and the population within primary care with depression is large, the preferred way to implement the approach has not been identified

    Near-infrared synchrotron emission from the compact jet of GX339-4

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    We have compiled contemporaneous broadband observations of the black hole candidate X-ray binary GX 339-4 when in the low/hard X-ray state in 1981 and 1997. The data clearly reveal the presence of two spectral components, with thermal and non-thermal spectra, overlapping in the optical -- near-infrared bands. The non-thermal component lies on an extrapolation of the radio spectrum of the source, and we interpret it as optically thin synchrotron emission from the powerful, compact jet in the system. Detection of this break from self-absorbed to optically thin synchrotron emission from the jet allows us to place a firm lower limit on the ratio of jet (synchrotron) to X-ray luminosities of 5\geq 5%. We further note that extrapolation of the optically thin synchrotron component from the near-infrared to higher frequencies coincides with the observed X-ray spectrum, supporting models in which the X-rays could originate via optically thin synchrotron emission from the jet (possibly instead of Comptonisation).Comment: Accepted for publication in ApJ Lette

    Worker injuries involving the interaction of cattle, cattle handlers, and farm structures or equipment

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    Citation: Fox, S., Ricketts, M., & Minton, J. E. (2015). Worker injuries involving the interaction of cattle, cattle handlers, and farm structures or equipment. Journal of Agricultural Safety and Health, 21(1), 3-12. doi:10.13031/jash.21.10221Cattle have been identified as leading sources of injuries to agricultural workers. The present study focused on worker injuries that involved the interaction of cattle, cattle handlers, and farm structures or equipment. The goal of the study was to identify opportunities for injury prevention. We examined 221 reports of injury to cattle handlers from the Consumer Product Safety Commission's National Electronic Injury Surveillance System (NEISS). Expected interactions led to many of the cattle-handling injuries reported in the NEISS database. In almost 30% of cases, cattle pushed workers into structures such as fences, gates, posts, and walls. In another 16% to 19% of injuries, cattle struck gates and other objects, propelling them at the victims. The present research makes several important contributions to the study of cattle-handling injuries. First, the research supports an increased emphasis on the development of safer gate designs (e.g., gates that are remotely operated or that absorb energy to limit the speed at which they may be propelled by animals). Second, the research suggests a need for additional study of energy-absorbing fence and wall structures. We view these two points to be of significance because gates and associated structures (e.g., posts, fences, and walls) accounted for 45% of the injuries in the dataset, based on the associated injury narrative. Finally, the research identifies a previously unexplored source of agricultural injury data, namely the NEISS database. © 2015 ASABE

    The role of orthographic and semantic learning in word reading and reading comprehension

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    We tested the theoretically driven hypotheses that children’s orthographic and semantic learning are associated with their word reading and reading comprehension skills, even when orthographic and semantic knowledge are taken into account. A sample of 139 English-speaking Grade 3 children completed a learning task in which they read stories about new inventions. Then they were tested on their learning of the spelling and meaning of the inventions (i.e., orthographic and semantic learning, respectively). Word reading and reading comprehension were assessed with standardised tasks, and orthographic and semantic knowledge were assessed with choice tasks targeting the spelling and meaning of existing words. The results of our structural equation modeling indicated that orthographic learning predicted word reading directly and reading comprehension indirectly via word reading. We also found that semantic learning predicted reading comprehension directly. These findings support integration of the self-teaching hypothesis and the lexical quality hypothesis

    Candidates registered for reasonable adjustments underperform compared to other candidates in the national undergraduate Prescribing Safety Assessment: Retrospective cohort analysis (2014-2018).

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    AIMS: Candidates with disabilities are eligible for reasonable adjustments (RA) while undertaking the national Prescribing Safety Assessment (PSA). The PSA is a novel open-book, time-constrained, multiformat assessment that may pose challenges to candidates with dyslexia and other disabilities. METHODS: Retrospective cohort analysis of 36 140 UK candidates undertaking first-sitting of the PSA (2014-2018). RESULTS: Of the 36 140 candidates, 9.1% (3284) were registered for RA. The RA group had lower pass rates (absolute difference 1.94%, 95% confidence interval 1.01-2.87%; P < .001) and assessment scores (1.16 percentage marks, 95% confidence interval 0.83-1.48; P < .001) compared with the non-RA group. This absolute difference is small relative to overall variability. This difference persists after adjusting for confounding factors (medical school and paper), and was present for all 8 different question types. The attainment gap within each medical school is negatively correlated with the school's overall performance, both in terms of pass rate (P < .001) and scores (P = .01). The RA group were also less likely to perceive the PSA as an appropriate test, having easy to follow layout/presentation or clear/unambiguous questions, even after adjusting for candidate performance. CONCLUSION: This analysis identifies slight differences in academic performance of candidates requiring RA in a national undergraduate assessment. The study is limited by the unavailability of data on ethnicity, sex, age, diagnosis and time of diagnosis. While further research is required to determine the cause of the attainment gap, this study emphasises the need to maintain a careful review on the fairness and validity of all aspects of the assessment
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