2,745 research outputs found

    A Hydrodynamic-Sediment Transport Numerical Model for the Waipaoa Shelf, New Zealand: Model Archive

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    These files are compressed versions of input files, model code, and output used for two publications: Moriarty, J. M., Harris, C. K., and Hadfield, M. G. (2014). A hydrodynamic and sediment transport model for the Waipaoa Shelf, New Zealand: Sensitivity of fluxes to spatially-varying erodibility and model nesting. Journal of Marine Science and Engineering, 2 (2): 336-369. Doi:10.3390/jmse2020336 Moriarty, J. M., Harris, C. K., and Hadfield, M. G. (2015). Event-to-seasonal sediment dispersal on the Waipaoa River Shelf, New Zealand: A numerical modeling study. Continental Shelf Research, 110: 108-123. Doi: 10.1016/j.csr2015.10.005 Compressed files with the .gz file extension can be opened with Gzip GNU software (open source). Compressed files with the .tar file extension can be opened with Gzip Tar software (open source). Many of the input / output files use the NetCDF (Network Common Data Form) file format. These have "nc" as a file extension and can be read using a variety of open source tools: see http://www.unidata.ucar.edu/software/netcdf/docs/ . For information about the Regional Ocean Modeling System (ROMS), its model code and input / output, see www.myroms.org

    A Hydrodynamic and Sediment Transport Model for the Waipaoa Shelf, New Zealand: Sensitivity of Fluxes to Spatially-Varying Erodibility and Model Nesting

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    Numerical models can complement observations in investigations of marine sediment transport and depositional processes. A coupled hydrodynamic and sediment transport model was implemented for the Waipaoa River continental shelf offshore of the North Island of New Zealand, to complement a 13-month field campaign that collected seabed and hydrodynamic measurements. This paper described the formulations used within the model, and analyzed the sensitivity of sediment flux estimates to model nesting and seabed erodibility. Calculations were based on the Regional Ocean Modeling System—Community Sediment Transport Modeling System (ROMS-CSTMS), a primitive equation model using a finite difference solution to the equations for momentum and water mass conservation, and transport of salinity, temperature, and multiple classes of suspended sediment. The three-dimensional model resolved the complex bathymetry, bottom boundary layer, and river plume that impact sediment dispersal on this shelf, and accounted for processes including fluvial input, winds, waves, tides, and sediment resuspension. Nesting within a larger-scale, lower resolution hydrodynamic model stabilized model behavior during river floods and allowed large-scale shelf currents to impact sediment dispersal. To better represent observations showing that sediment erodibility decreased away from the river mouth, the seabed erosion rate parameter was reduced with water depth. This allowed the model to account for the observed spatial pattern of erodibility, though the model held the critical shear stress for erosion constant. Although the model neglected consolidation and swelling processes, use of a spatially-varying erodibility parameter significantly increased export of fluvial sediment from Poverty Bay to deeper areas of the shelf

    Achieving Behavioral Health Care Integration in Rural America

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    Integrating primary care services and treatment for mental health and substance use conditions not only enhances patients' access to needed care but also improves health outcomes in a cost-effective way. Yet the barriers to integrated care are substantial, and it is even more difficult to achieve in rural and frontier communities, which are home to 1 in 7 Americans.Our current work focuses on breaking down the barriers to integration in rural America, where the health care infrastructure and provider composition vary in distinct ways from urban and suburban areas. Americans in rural areas face significant shortages of psychiatrists, psychologists, clinical social workers, and other behavioral health specialists. More than 60% of nonmetropolitan counties lack a psychiatrist, and almost half of nonmetropolitan counties do not have a psychologist, compared with 27% and 19% of urban counties, respectively. These gaps in specialty care force rural residents to rely heavily on primary providers for much of their care

    Risk of infection in type 1 and type 2 diabetes compared with the general population: a matched cohort study

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    OBJECTIVE We describe in detail the burden of infections in adults with diabetes within a large national population cohort. We also compare infection rates between patients with type 1 and type 2 diabetes mellitus (T1DM and T2DM). RESEARCH DESIGN AND METHODS A retrospective cohort study compared 102,493 English primary care patients aged 40–89 years with a diabetes diagnosis by 2008 (n = 5,863 T1DM and n = 96,630 T2DM) with 203,518 age-sex-practice–matched control subjects without diabetes. Infection rates during 2008–2015, compiled from primary care and linked hospital and mortality records, were compared across 19 individual infection categories. These were further summarized as any requiring a prescription or hospitalization or as cause of death. Poisson regression was used to estimate incidence rate ratios (IRRs) between 1) people with diabetes and control subjects and 2) T1DM and T2DM adjusted for age, sex, smoking, BMI, and deprivation. RESULTS Compared with control subjects without diabetes, patients with diabetes had higher rates for all infections, with the highest IRRs seen for bone and joint infections, sepsis, and cellulitis. IRRs for infection-related hospitalizations were 3.71 (95% CI 3.27–4.21) for T1DM and 1.88 (95% CI 1.83–1.92) for T2DM. A direct comparison of types confirmed higher adjusted risks for T1DM versus T2DM (death from infection IRR 2.19 [95% CI 1.75–2.74]). We estimate that 6% of infection-related hospitalizations and 12% of infection-related deaths were attributable to diabetes. CONCLUSIONS People with diabetes, particularly T1DM, are at increased risk of serious infection, representing an important population burden. Strategies that reduce the risk of developing severe infections and poor treatment outcomes are under-researched and should be explored

    "It's not just about walking.....it's the practice nurse that makes it work": a qualitative exploration of the views of practice nurses delivering complex physical activity interventions in primary care

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    Background: Physical activity (PA) is important for physical and mental health in adults and older adults. Interventions incorporating theory-based behaviour change techniques (BCTs) can be useful in helping people to increase their PA levels and can be delivered by practice nurses in primary care. We undertook two primary care based complex walking interventions among adults and older adults. Both interventions were underpinned by BCTs and delivered by practice nurses and we sought their views and experiences of delivering over 1400 complex PA consultations.  Methods: Semi structured interviews with two practice nurse groups (n = 4 and n = 5) and two individual interviews (total n = 11) were conducted by independent facilitators; audio-recorded, transcribed verbatim and analysed using thematic analysis.  Results: Five key themes emerged as enablers and/or barriers to delivering the intervention: preparation and training; initial and ongoing support; adherence to the protocol; the use of materials and equipment; and engagement of participants. The themes were organised into a framework of 'pre-trial' and 'delivery of the intervention'. Two additional 'post-trial' themes were identified; changed practice and the future feasibility of the intervention. Nurses believed that taking part in the trial, especially the BCT training, enhanced the quality and delivery of advice and support they provided within routine consultations, although the lack of time available routinely makes this challenging.  Conclusion: Delivering an effective behaviour change intervention in primary care requires adequate training and support for practice nurses both initially and throughout the trial as well as adequate consultation time. Enhanced skills from participating in such trials can lead to long-term changes, including more patient-centred consulting.  Trial registration: PACE-Lift ISRCTN 42122561, PACE-UP ISRCTN 98538934

    Cx43/miR21/HMGB1/RANKL pathway in osteocytes

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    Skeletal aging results in apoptosis of osteocytes, cells embedded in bone that control the generation/function of bone forming and resorbing cells. Aging also decreases connexin43 (Cx43) expression in bone; and osteocytic Cx43 deletion partially mimics the skeletal phenotype of old mice. Particularly, aging and Cx43 deletion increase osteocyte apoptosis, and osteoclast number and bone resorption on endocortical bone surfaces. We examined herein the molecular signaling events responsible for osteocyte apoptosis and osteoclast recruitment triggered by aging and Cx43 deficiency. Cx43-silenced MLO-Y4 osteocytic (Cx43def) cells undergo spontaneous cell death in culture through caspase-3 activation and exhibit increased levels of apoptosis-related genes, and only transfection of Cx43 constructs able to form gap junction channels reverses Cx43def cell death. Cx43def cells and bones from old mice exhibit reduced levels of the pro-survival microRNA miR21 and, consistently, increased levels of the miR21 target phosphatase and tensin homolog (PTEN) and reduced phosphorylated Akt, whereas PTEN inhibition reduces Cx43def cell apoptosis. miR21 reduction is sufficient to induce apoptosis of Cx43-expressing cells and miR21 deletion in miR21fl/fl bones increases apoptosis-related gene expression, whereas a miR21 mimic prevents Cx43def cell apoptosis, demonstrating that miR21 lies downstream of Cx43. Cx43def cells release more osteoclastogenic cytokines [receptor activator of NFκB ligand (RANKL)/high-mobility group box-1 (HMGB1)], and caspase-3 inhibition prevents RANKL/HMGB1 release and the increased osteoclastogenesis induced by conditioned media from Cx43def cells, which is blocked by antagonizing HMGB1-RAGE interaction. These findings identify a novel Cx43/miR21/HMGB1/RANKL pathway involved in preventing osteocyte apoptosis that also controls osteoclast formation/recruitment and is impaired with aging

    What is the 'problem' that outreach work seeks to address and how might it be tackled? Seeking theory in a primary health prevention programme

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    <b>Background</b> Preventive approaches to health are disproportionately accessed by the more affluent and recent health improvement policy advocates the use of targeted preventive primary care to reduce risk factors in poorer individuals and communities. Outreach has become part of the health service response. Outreach has a long history of engaging those who do not otherwise access services. It has, however, been described as eclectic in its purpose, clientele and mode of practice; its effectiveness is unproven. Using a primary prevention programme in the UK as a case, this paper addresses two research questions: what are the perceived problems of non-engagement that outreach aims to address; and, what specific mechanisms of outreach are hypothesised to tackle these.<p></p> <b>Methods</b> Drawing on a wider programme evaluation, the study undertook qualitative interviews with strategically selected health-care professionals. The analysis was thematically guided by the concept of 'candidacy' which theorises the dynamic process through which services and individuals negotiate appropriate service use.<p></p> <b>Results</b> The study identified seven types of engagement 'problem' and corresponding solutions. These 'problems' lie on a continuum of complexity in terms of the challenges they present to primary care. Reasons for non-engagement are congruent with the concept of 'candidacy' but point to ways in which it can be expanded.<p></p> <b>Conclusions</b> The paper draws conclusions about the role of outreach in contributing to the implementation of inequalities focused primary prevention and identifies further research needed in the theoretical development of both outreach as an approach and candidacy as a conceptual framework

    Disclinations, dislocations and continuous defects: a reappraisal

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    Disclinations, first observed in mesomorphic phases, are relevant to a number of ill-ordered condensed matter media, with continuous symmetries or frustrated order. They also appear in polycrystals at the edges of grain boundaries. They are of limited interest in solid single crystals, where, owing to their large elastic stresses, they mostly appear in close pairs of opposite signs. The relaxation mechanisms associated with a disclination in its creation, motion, change of shape, involve an interplay with continuous or quantized dislocations and/or continuous disclinations. These are attached to the disclinations or are akin to Nye's dislocation densities, well suited here. The notion of 'extended Volterra process' takes these relaxation processes into account and covers different situations where this interplay takes place. These concepts are illustrated by applications in amorphous solids, mesomorphic phases and frustrated media in their curved habit space. The powerful topological theory of line defects only considers defects stable against relaxation processes compatible with the structure considered. It can be seen as a simplified case of the approach considered here, well suited for media of high plasticity or/and complex structures. Topological stability cannot guarantee energetic stability and sometimes cannot distinguish finer details of structure of defects.Comment: 72 pages, 36 figure

    Suv4-20h Histone Methyltransferases Promote Neuroectodermal Differentiation by Silencing the Pluripotency-Associated Oct-25 Gene

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    Post-translational modifications (PTMs) of histones exert fundamental roles in regulating gene expression. During development, groups of PTMs are constrained by unknown mechanisms into combinatorial patterns, which facilitate transitions from uncommitted embryonic cells into differentiated somatic cell lineages. Repressive histone modifications such as H3K9me3 or H3K27me3 have been investigated in detail, but the role of H4K20me3 in development is currently unknown. Here we show that Xenopus laevis Suv4-20h1 and h2 histone methyltransferases (HMTases) are essential for induction and differentiation of the neuroectoderm. Morpholino-mediated knockdown of the two HMTases leads to a selective and specific downregulation of genes controlling neural induction, thereby effectively blocking differentiation of the neuroectoderm. Global transcriptome analysis supports the notion that these effects arise from the transcriptional deregulation of specific genes rather than widespread, pleiotropic effects. Interestingly, morphant embryos fail to repress the Oct4-related Xenopus gene Oct-25. We validate Oct-25 as a direct target of xSu4-20h enzyme mediated gene repression, showing by chromatin immunoprecipitaton that it is decorated with the H4K20me3 mark downstream of the promoter in normal, but not in double-morphant, embryos. Since knockdown of Oct-25 protein significantly rescues the neural differentiation defect in xSuv4-20h double-morphant embryos, we conclude that the epistatic relationship between Suv4-20h enzymes and Oct-25 controls the transit from pluripotent to differentiation-competent neural cells. Consistent with these results in Xenopus, murine Suv4-20h1/h2 double-knockout embryonic stem (DKO ES) cells exhibit increased Oct4 protein levels before and during EB formation, and reveal a compromised and biased capacity for in vitro differentiation, when compared to normal ES cells. Together, these results suggest a regulatory mechanism, conserved between amphibians and mammals, in which H4K20me3-dependent restriction of specific POU-V genes directs cell fate decisions, when embryonic cells exit the pluripotent state

    Sex-Differential Herbivory in Androdioecious Mercurialis annua

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    Males of plants with separate sexes are often more prone to attack by herbivores than females. A common explanation for this pattern is that individuals with a greater male function suffer more from herbivory because they grow more quickly, drawing more heavily on resources for growth that might otherwise be allocated to defence. Here, we test this ‘faster-sex’ hypothesis in a species in which males in fact grow more slowly than hermaphrodites, the wind-pollinated annual herb Mercurialis annua. We expected greater herbivory in the faster-growing hermaphrodites. In contrast, we found that males, the slower sex, were significantly more heavily eaten by snails than hermaphrodites. Our results thus reject the faster-sex hypothesis and point to the importance of a trade-off between defence and reproduction rather than growth
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