4,736 research outputs found

    Restored saltmarshes have low beta diversity due to limited topographic variation, but this can be countered by management

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    1. Spatial heterogeneity of species (beta diversity) is an important attribute of ecological communities, but is less frequently considered when assessing restoration success than other aspects of diversity (gamma and alpha). Differences in beta diversity between restored and natural sites may arise due to differences in environmental heterogeneity. 2. We used a nested sampling design to survey plant communities and environmental conditions (elevation, redox potential and metrics of topography) on four pairs of restored and natural saltmarshes. We assessed whether there were differences in both alpha and beta diversity between natural and restored sites and analysed their environmental drivers. 3. Topography was an important driver of plant alpha diversity and beta diversity on saltmarshes. The effects of topography were partly indirect, mediated though changes in redox potential, but topography also influenced plant communities independently of both elevation and redox. 4. Restored saltmarshes were less heterogeneous in topography than natural marshes. This reduced topography was reflected in lower beta diversity; plant communities 1 m apart in natural marshes were as dissimilar as those found 20 m apart in restored marshes. 5. Large-scale topographic manipulation carried out at one site a decade after initial restoration successfully increased topographic heterogeneity and increased beta diversity when surveyed 3 years after manipulation. These changes were still evident when resurveyed after a further 2 years. 6. Synthesis and applications. Increasing environmental heterogeneity can improve restoration outcomes by increasing beta diversity on restored sites. The effect of environmental heterogeneity is likely to be particularly strong within intertidal habitats such as saltmarshes, where small changes in topography can determine whether a species can occur at a given location. Topographic manipulation is a feasible post-restoration technique that can be applied to ensure restored saltmarshes better meet policy targets of biological, physical and functional equivalence with natural marshes

    Effectiveness of enhanced diabetes care to patients of South Asian ethnicity : the United Kingdom Asian Diabetes Study (UKADS) : a cluster randomised controlled trial

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    Background: Delivering high quality and evidence based healthcare to deprived sectors of the community is a major goal for society. We investigated the effectiveness of a culturally sensitive enhanced care package in UK general practice in improving cardiovascular risk factors in South Asian patients with type 2 diabetes. Methods: 21 inner city practices were randomised to intervention (enhanced practice nurse time, link worker and diabetes specialist nurse support) (n=868) or control (standard care) (n=618) groups. Prescribing algorithms with clearly defined targets were provided for all practices. Main outcome measures comprised changes in blood pressure, total cholesterol and glycaemic control (HbA1c) after 2 years. Findings: At baseline, groups were similar with respect to age, sex and cardiovascular risk factors. Comparing treatment groups, after adjustment for confounders, and clustering, differences in diastolic blood pressure (1.91mmHg, P=0.0001) and mean arterial pressure (1.36mmHg, P=0.0180) were significant. There were no significant differences between groups for total cholesterol or HbA1c. Economic analysis indicates the nurse-led intervention was not cost-effective. Across the whole study population systolic blood pressure, diastolic blood pressure and cholesterol decreased significantly by 4.9mmHg, 3.8mmHg and 0.45mmol/L respectively, but there was no change in HbA1c. Interpretation: Additional, although limited, benefits were observed from our culturally enhanced care package over and above the secular changes achieved in the UK in recent years. Stricter targets in general practice and further measures to motivate patients are needed to maximise healthcare outcomes in South Asian patients with diabetes

    Species interactions modulate the response of saltmarsh plants to flooding

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    Background and aims The vegetation that grows on coastal wetlands is important for ecosystem functioning, a role mediated by plant traits. These traits can be affected by environmental stressors and by the competitive environment the plant experiences. The relative importance of these influences on different traits is poorly understood and, despite theoretical expectations for how factors may interact, empirical data are conflicting. Our aims are to determine the effect of flooding, species composition and their interaction on plant functional traits, and assess the role of biodiversity and species composition in driving community-level responses to flooding. Methods We conducted a factorial glasshouse experiment assessing the effects of species composition (all combinations of three saltmarsh species, Aster tripolium, Plantagomaritima and Triglochin maritima) and flooding (immersion of roots) on a suite of functional traits. We also related biomass in mixed species pots to that expected from monocultures to assess how species interactions affect community-level biomass. Key results Species composition frequently interacted with flooding to influence functional traits and community level properties. However, there was also considerable intraspecific variability in traits within each treatment. Generally, effects of flooding were more pronounced for belowground than aboveground biomass, while composition affected aboveground biomass more than belowground biomass. We found both negative and positive interactions between species (indicated by differences in above and belowground biomass from expectations under monoculture), meaning that composition was an important determinate of community function. Conclusions While the effect of flooding alone on traits was relatively weak, it interacted with species composition to modify the response of both individual plants and communities. Our results suggest that responses to increased flooding will be complex and depend on neighbourhood species interactions. Furthermore, intraspecific trait variability is a potential resource that may dampen the effects of changes in flooding regime

    What guidance are researchers given on how to present network meta-analyses to end-users such as policymakers and clinicians? A systematic review

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    © 2014 Sullivan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Introduction: Network meta-analyses (NMAs) are complex methodological approaches that may be challenging for non-technical end-users, such as policymakers and clinicians, to understand. Consideration should be given to identifying optimal approaches to presenting NMAs that help clarify analyses. It is unclear what guidance researchers currently have on how to present and tailor NMAs to different end-users. Methods: A systematic review of NMA guidelines was conducted to identify guidance on how to present NMAs. Electronic databases and supplementary sources were searched for NMA guidelines. Presentation format details related to sample formats, target audiences, data sources, analysis methods and results were extracted and frequencies tabulated. Guideline quality was assessed following criteria developed for clinical practice guidelines. Results: Seven guidelines were included. Current guidelines focus on how to conduct NMAs but provide limited guidance to researchers on how to best present analyses to different end-users. None of the guidelines provided reporting templates. Few guidelines provided advice on tailoring presentations to different end-users, such as policymakers. Available guidance on presentation formats focused on evidence networks, characteristics of individual trials, comparisons between direct and indirect estimates and assumptions of heterogeneity and/or inconsistency. Some guidelines also provided examples of figures and tables that could be used to present information. Conclusions: Limited guidance exists for researchers on how best to present NMAs in an accessible format, especially for non-technical end-users such as policymakers and clinicians. NMA guidelines may require further integration with end-users' needs, when NMAs are used to support healthcare policy and practice decisions. Developing presentation formats that enhance understanding and accessibility of NMAs could also enhance the transparency and legitimacy of decisions informed by NMAs.The Canadian Institute of Health Research (CIHR) Drug Safety and Effectiveness Network (Funding reference number – 116573)

    Characterizing Interdisciplinarity of Researchers and Research Topics Using Web Search Engines

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    Researchers' networks have been subject to active modeling and analysis. Earlier literature mostly focused on citation or co-authorship networks reconstructed from annotated scientific publication databases, which have several limitations. Recently, general-purpose web search engines have also been utilized to collect information about social networks. Here we reconstructed, using web search engines, a network representing the relatedness of researchers to their peers as well as to various research topics. Relatedness between researchers and research topics was characterized by visibility boost-increase of a researcher's visibility by focusing on a particular topic. It was observed that researchers who had high visibility boosts by the same research topic tended to be close to each other in their network. We calculated correlations between visibility boosts by research topics and researchers' interdisciplinarity at individual level (diversity of topics related to the researcher) and at social level (his/her centrality in the researchers' network). We found that visibility boosts by certain research topics were positively correlated with researchers' individual-level interdisciplinarity despite their negative correlations with the general popularity of researchers. It was also found that visibility boosts by network-related topics had positive correlations with researchers' social-level interdisciplinarity. Research topics' correlations with researchers' individual- and social-level interdisciplinarities were found to be nearly independent from each other. These findings suggest that the notion of "interdisciplinarity" of a researcher should be understood as a multi-dimensional concept that should be evaluated using multiple assessment means.Comment: 20 pages, 7 figures. Accepted for publication in PLoS On

    Similarity solutions for unsteady shear-stress-driven flow of Newtonian and power-law fluids : slender rivulets and dry patches

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    Unsteady flow of a thin film of a Newtonian fluid or a non-Newtonian power-law fluid with power-law index N driven by a constant shear stress applied at the free surface, on a plane inclined at an angle α to the horizontal, is considered. Unsteady similarity solutions representing flow of slender rivulets and flow around slender dry patches are obtained. Specifically, solutions are obtained for converging sessile rivulets (0 < α < π/2) and converging dry patches in a pendent film (π/2 < α < π), as well as for diverging pendent rivulets and diverging dry patches in a sessile film. These solutions predict that at any time t, the rivulet and dry patch widen or narrow according to |x|3/2, and the film thickens or thins according to |x|, where x denotes distance down the plane, and that at any station x, the rivulet and dry patch widen or narrow like |t|−1, and the film thickens or thins like |t|−1, independent of N

    PKMζ is essential for spinal plasticity underlying the maintenance of persistent pain

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    <p>Abstract</p> <p>Background</p> <p>Chronic pain occurs when normally protective acute pain becomes pathologically persistent. We examined here whether an isoform of protein kinase C (PKC), PKMζ, that underlies long-term memory storage in various brain regions, also sustains nociceptive plasticity in spinal cord dorsal horn (SCDH) mediating persistent pain.</p> <p>Results</p> <p>Cutaneous injury or spinal stimulation produced persistent increases of PKMζ, but not other atypical PKCs in SCDH. Inhibiting spinal PKMζ, but not full-length PKCs, reversed plasticity-dependent persistent painful responses to hind paw formalin and secondary mechanical hypersensitivity and SCDH neuron sensitization after hind paw capsaicin, without affecting peripheral sensitization-dependent primary heat hypersensitivity after hind paw capsaicin. Inhibiting spinal PKMζ, but not full-length PKCs, also reversed mechanical hypersensitivity in the rat hind paw induced by spinal stimulation with intrathecal dihydroxyphenylglycine. Spinal PKMζ inhibition also alleviated allodynia 3 weeks after ischemic injury in rats with chronic post-ischemia pain (CPIP), at a point when allodynia depends on spinal changes. In contrast, spinal PKMζ inhibition did not affect allodynia in rats with chronic contriction injury (CCI) of the sciatic nerve, or CPIP rats early after ischemic injury, when allodynia depends on ongoing peripheral inputs.</p> <p>Conclusions</p> <p>These results suggest spinal PKMζ is essential for the maintenance of persistent pain by sustaining spinal nociceptive plasticity.</p

    Sequential induction of three recombination directionality factors directs assembly of tripartite integrative and conjugative elements

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    Tripartite integrative and conjugative elements (ICE3) are a novel form of ICE that exist as three separate DNA regions integrated within the genomes of Mesorhizobium spp. Prior to conjugative transfer the three ICE3 regions of M. ciceri WSM1271 ICEMcSym1271 combine and excise to form a single circular element. This assembly requires three coordinated recombination events involving three site-specific recombinases IntS, IntG and IntM. Here, we demonstrate that three excisionases–or recombination directionality factors—RdfS, RdfG and RdfM are required for ICE3 excision. Transcriptome sequencing revealed that expression of ICE3 transfer and conjugation genes was induced by quorum sensing. Quorum sensing activated expression of rdfS, and in turn RdfS stimulated transcription of both rdfG and rdfM. Therefore, RdfS acts as a “master controller” of ICE3 assembly and excision. The dependence of all three excisive reactions on RdfS ensures that ICE3 excision occurs via a stepwise sequence of recombination events that avoids splitting the chromosome into a non-viable configuration. These discoveries expose a surprisingly simple control system guiding molecular assembly of these novel and complex mobile genetic elements and highlight the diverse and critical functions of excisionase proteins in control of horizontal gene transfer

    Can programme theory be used as a 'translational tool’ to optimise health service delivery in a national early years’ initiative in Scotland: a case study

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    Background Theory-based evaluation (TBE) approaches are heralded as supporting formative evaluation by facilitating increased use of evaluative findings to guide programme improvement. It is essential that learning from programme implementation is better used to improve delivery and to inform other initiatives, if interventions are to be as effective as they have the potential to be. Nonetheless, few studies describe formative feedback methods, or report direct instrumental use of findings resulting from TBE. This paper uses the case of Scotland’s, National Health Service, early years’, oral health improvement initiative (Childsmile) to describe the use of TBE as a framework for providing feedback on delivery to programme staff and to assess its impact on programmatic action.&lt;p&gt;&lt;/p&gt; Methods In-depth, semi-structured interviews and focus groups with key stakeholders explored perceived deviations between the Childsmile programme 'as delivered’ and its Programme Theory (PT). The data was thematically analysed using constant comparative methods. Findings were shared with key programme stakeholders and discussions around likely impact and necessary actions were facilitated by the authors. Documentary review and ongoing observations of programme meetings were undertaken to assess the extent to which learning was acted upon.&lt;p&gt;&lt;/p&gt; Results On the whole, the activities documented in Childsmile’s PT were implemented as intended. This paper purposefully focuses on those activities where variation in delivery was evident. Differences resulted from the stage of roll-out reached and the flexibility given to individual NHS boards to tailor local implementation. Some adaptations were thought to have diverged from the central features of Childsmile’s PT, to the extent that there was a risk to achieving outcomes. The methods employed prompted national service improvement action, and proposals for local action by individual NHS boards to address this.&lt;p&gt;&lt;/p&gt; Conclusions The TBE approach provided a platform, to direct attention to areas of risk within a national health initiative, and to agree which intervention components were 'core’ to its hypothesised success. The study demonstrates that PT can be used as a 'translational tool’ to facilitate instrumental use of evaluative findings to optimise implementation within a complex health improvement programme.&lt;p&gt;&lt;/p&gt
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