222 research outputs found

    Humans Strengthen Bottom-Up Effects and Weaken Trophic Cascades in a Terrestrial Food Web

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    Ongoing debate about whether food webs are primarily regulated by predators or by primary plant productivity, cast as top-down and bottom-up effects, respectively, may becoming superfluous. Given that most of the world\u27s ecosystems are human dominated we broadened this dichotomy by considering human effects in a terrestrial food-web. We studied a multiple human-use landscape in southwest Alberta, Canada, as opposed to protected areas where previous terrestrial food-web studies have been conducted. We used structural equation models (SEMs) to assess the strength and direction of relationships between the density and distribution of: (1) humans, measured using a density index; (2) wolves (Canis lupus), elk (Cervus elpahus) and domestic cattle (Bos taurus), measured using resource selection functions, and; (3) forage quality, quantity and utilization (measured at vegetation sampling plots). Relationships were evaluated by taking advantage of temporal and spatial variation in human density, including day versus night, and two landscapes with the highest and lowest human density in the study area. Here we show that forage-mediated effects of humans had primacy over predator-mediated effects in the food web. In our parsimonious SEM, occurrence of humans was most correlated with occurrence of forage (beta = 0.637, p \u3c 0.0001). Elk and cattle distribution were correlated with forage (elk day: beta = 0.400, p \u3c 0.0001; elk night: beta = 0.369, p \u3c 0.0001; cattle day: beta = 0.403, p \u3c 0.0001; cattle, night: beta = 0.436, p \u3c 0.0001), and the distribution of elk or cattle and wolves were positively correlated during daytime (elk: beta = 0.293, p \u3c 0.0001, cattle: beta = 0.303, p \u3c 0.0001) and night-time (elk: beta = 0.460, p \u3c 0.0001, cattle: beta = 0.482, p \u3c 0.0001). Our results contrast with research conducted in protected areas that suggested human effects in the food web are primarily predator-mediated. Instead, human influence on vegetation may strengthen bottom-up predominance and weaken top-down trophic cascades in ecosystems. We suggest that human influences on ecosystems may usurp top-down and bottom-up effects

    Building community resilience in the re-settlement of displaced communities

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    In natural disaster and man-made conflict scenarios, livelihoods, assets, community networks and relationships get destroyed and in many areas, lives and communities are devastated. Re-settling these communities and providing them the essential support to adapt to the new or changed environments has been a major challenge for governments. Taking into consideration case studies from two South Asian countries, Bangladesh and Sri Lanka, this paper explores the displacement and re-location cycle experienced and the impact disaster, conflict and reconciliation has on families, community and stakeholder relationships and networks as they re-build their lives in the re-settlement process. The case studies were selected from available literature to focus on different kinds of natural disasters and civil conflicts. The paper focuses on characteristics of resilient communities and how these characteristics have aided the recovery and re-settlement. It also identifies attributes that are inherent in communities that have undergone disaster and displacement and explores how these attributes have helped communities in re-building their lives. From the literature and the case study results and information, it is seen that topics of safety, security, and livelihoods summarises the core needs that are important for transitional settlement and shelter. Having ownership of assets, a shelter or dwelling unit or land is also important in the re-settlement process. These requirements vary according to the ethnicity, religion and culture and the challenges for the relief agencies are to provide alternative solutions that match these requirements in the short and long term

    Lamotrigine for people with borderline personality disorder: a RCT

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    Background: No drug treatments are currently licensed for the treatment of borderline personality disorder (BPD). Despite this, people with this condition are frequently prescribed psychotropic medications and often with considerable polypharmacy. Preliminary studies have indicated that mood stabilisers may be of benefit to people with BPD. Objective: To examine the clinical effectiveness and cost-effectiveness of lamotrigine for people with BPD. Design: A two-arm, double-blind, placebo-controlled individually randomised trial of lamotrigine versus placebo. Participants were randomised via an independent and remote web-based service using permuted blocks and stratified by study centre, the severity of personality disorder and the extent of hypomanic symptoms. Setting: Secondary care NHS mental health services in six centres in England. Participants: Potential participants had to be aged ≥ 18 years, meet diagnostic criteria for BPD and provide written informed consent. We excluded people with coexisting psychosis or bipolar affective disorder, those already taking a mood stabiliser, those who spoke insufficient English to complete the baseline assessment and women who were pregnant or contemplating becoming pregnant. Interventions: Up to 200 mg of lamotrigine per day or an inert placebo. Women taking combined oral contraceptives were prescribed up to 400 mg of trial medication per day. Main outcome measures: Outcomes were assessed at 12, 24 and 52 weeks after randomisation. The primary outcome was the total score on the Zanarini Rating Scale for Borderline Personality Disorder (ZAN-BPD) at 52 weeks. The secondary outcomes were depressive symptoms, deliberate self-harm, social functioning, health-related quality of life, resource use and costs, side effects of treatment and adverse events. Higher scores on all measures indicate poorer outcomes. Results: Between July 2013 and October 2015 we randomised 276 participants, of whom 195 (70.6%) were followed up 52 weeks later. At 52 weeks, 49 (36%) of those participants prescribed lamotrigine and 58 (42%) of those prescribed placebo were taking it. At 52 weeks, the mean total ZAN-BPD score was 11.3 [standard deviation (SD) 6.6] among those participants randomised to lamotrigine and 11.5 (SD 7.7) among those participants randomised to placebo (adjusted mean difference 0.1, 95% CI –1.8 to 2.0; p = 0.91). No statistically significant differences in secondary outcomes were seen at any time. Adjusted costs of direct care for those prescribed lamotrigine were similar to those prescribed placebo. Limitations: Levels of adherence in this pragmatic trial were low, but greater adherence was not associated with better mental health. Conclusions: The addition of lamotrigine to the usual care of people with BPD was not found to be clinically effective or provide a cost-effective use of resources. Future work: Future research into the treatment of BPD should focus on improving the evidence base for the clinical effectiveness and cost-effectiveness of non-pharmacological treatments to help policy-makers make better decisions about investing in specialist treatment services

    Melting and differentiation of early-formed asteroids: The perspective from high precision oxygen isotope studies

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    A number of distinct methodologies are available for determining the oxygen isotope composition of minerals and rocks, these include laser-assisted fluorination, secondary ion mass spectrometry (SIMS)and UV laser ablation. In this review we focus on laser-assisted fluorination, which currently achieves the highest levels of precision available for oxygen isotope analysis. In particular, we examine how results using this method have furthered our understanding of early-formed differentiated meteorites. Due to its rapid reaction times and low blank levels, laser-assisted fluorination has now largely superseded the conventional externally-heated Ni “bomb” technique for bulk analysis. Unlike UV laser ablation and SIMS analysis, laser-assisted fluorination is not capable of focused spot analysis. While laser fluorination is now a mature technology, further analytical improvements are possible via refinements to the construction of sample chambers, clean-up lines and the use of ultra-high resolution mass spectrometers. High-precision oxygen isotope analysis has proved to be a particularly powerful technique for investigating the formation and evolution of early-formed differentiated asteroids and has provided unique insights into the interrelationships between various groups of achondrites. A clear example of this is seenin samples that lie close to the terrestrial fractionation line (TFL). Based on the data from conventional oxygen isotope analysis, it was suggested that the main-group pallasites, the howardite eucrite diogenite suite (HEDs) and mesosiderites could all be derived from a single common parent body. However,high precision analysis demonstrates that main-group pallasites have a Δ17O composition that is fully resolvable from that of the HEDs and mesosiderites, indicating the involvement of at least two parent bodies. The range of Δ17O values exhibited by an achondrite group provides a useful means of assessing the extent to which their parent body underwent melting and isotopic homogenization. Oxygen isotope analysis can also highlight relationships between ungrouped achondrites and the more well-populated groups. A clear example of this is the proposed link between the evolved GRA 06128/9 meteorites and the brachinites. The evidence from oxygen isotopes, in conjunction with that from other techniques, indicates that we have samples from approximately 110 asteroidal parent bodies (∼60 irons, ∼35 achondrites and stony-iron, and ∼15 chondrites) in our global meteorite collection. However, compared to the likely size of the original protoplanetary asteroid population, this is an extremely low value. In addition, almost all of the differentiated samples (achondrites, stony-iron and irons) are derived from parent bodies that were highly disrupted early in their evolution. High-precision oxygen isotope analysis of achondrites provides some important insights into the origin of mass-independent variation in the early Solar System. In particular, the evidence from various primitive achondrite groups indicates that both the slope 1 (Y&R) and CCAM lines are of primordial significance. Δ17O differences between water ice and silicate-rich solids were probably the initial source of the slope 1 anomaly. These phases most likely acquired their isotopic composition as a result of UV photo-dissociation of CO that took place either in the early solar nebula or precursor giant molecular cloud. Such small-scale isotopic heterogeneities were propagated into larger-sized bodies, such as asteroids and planets, as a result of early Solar System processes, including dehydration, aqueous alteration,melting and collisional interactions

    Tuberculosis associated with Mycobacterium tuberculosis Beijing and non-Beijing genotypes: a clinical and immunological comparison

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    BACKGROUND: The Mycobacterium tuberculosis Beijing genotype is biologically different from other genotypes. We aimed to clinically and immunologically compare human tuberculosis caused by Beijing and non-Beijing strains. METHODS: Pulmonary tuberculosis patients were prospectively enrolled and grouped by their M. tuberculosis genotypes. The clinical features, plasma cytokine levels, and cytokine gene expression levels in peripheral blood mononuclear cells (PBMC) were compared between the patients in Beijing and non-Beijing groups. RESULTS: Patients in the Beijing group were characterized by significantly lower frequency of fever (odds ratio, 0.12, p = 0.008) and pulmonary cavitation (odds ratio, 0.2, p = 0.049). Night sweats were also significantly less frequent by univariate analysis, and the duration of cough prior to diagnosis was longer in Beijing compared to non-Beijing groups (medians, 60 versus 30 days, p = 0.048). The plasma and gene expression levels of interferon (IFN) γ and interleukin (IL)-18 were similar in the two groups. However, patients in the non-Beijing group had significantly increased IL-4 gene expression (p = 0.018) and lower IFN-γ : IL-4 cDNA copy number ratios (p = 0.01). CONCLUSION: Patients with tuberculosis caused by Beijing strains appear to be less symptomatic than those who have disease caused by other strains. Th1 immune responses are similar in patients infected with Beijing and non-Beijing strains, but non-Beijing strains activate more Th2 immune responses compared with Beijing strains, as evidenced by increased IL-4 expression

    The innovation of Multiview3 for development professionals

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    The Multiview Methodology for Information Systems Development has never been a widely used or mass-market approach. It has always had a small user base, a localised approach to a global issue: coherent IS development. This paper concerns the underreported innovation of the Multiview3 methodology for Information systems analysis, design and development – specifically designed for non-specialists working in developing countries. The innovation emerged from the identification of a methodological ‘gap’ in support for non-specialists struggling with Information Systems problem structuring challenges. The Multiview3 story tells us how IS methodology can be innovated to address the needs of users. This version of Multiview is argued to be theoretically distinct from previous versions in terms of its focus (developing countries) and application (problem solving and co-learning in practice)

    The clinical effectiveness and cost effectiveness of lamotrigine for people with borderline personality disorder: a randomized, placebo-controlled trial

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    Objectives: To examine whether lamotrigine is a clinically effective and cost-effective treatment for people with borderline personality disorder. Method: Multicentre, double-blind, placebo-controlled randomized trial. Between July 2013 to November 2016, we recruited 276 people aged 18 or over, who met diagnostic criteria for borderline personality disorder. We excluded those with co-existing bipolar affective disorder or psychosis, those already taking a mood stabiliser, and women at risk of pregnancy. We randomly allocated participants on a 1:1 ratio to up to 400mg of lamotrigine per day or an inert placebo using a remote web-based randomization service. The primary outcome was total score on the Zanarini Rating scale for Borderline Personality Disorder (ZAN-BPD) at 52 weeks. Secondary outcomes included depressive symptoms, deliberate self-harm, social functioning, health-related quality of life, resource use and costs, side effects of treatment and adverse events. Results: 195 (70.6%) participants were followed up at 52 weeks, at which point 49 (36%) of those prescribed lamotrigine and 58 (42%) of those prescribed placebo were taking it. Mean total ZAN-BPD score was 11.3 (SD = 6.6) among those randomized to lamotrigine and 11.5 (SD = 7.7) among those randomized to placebo (adjusted difference in means = 0.1, 95% C.I = -1.8 to 2.0, p=0.91). There was no evidence of any differences in secondary outcomes. Costs of direct care for those prescribed lamotrigine were similar to those prescribed placebo. Conclusions: Treating people with borderline personality disorder with lamotrigine is not a clinically effective or cost-effective use of resources

    De-identifying a public use microdata file from the Canadian national discharge abstract database

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    <p>Abstract</p> <p>Background</p> <p>The Canadian Institute for Health Information (CIHI) collects hospital discharge abstract data (DAD) from Canadian provinces and territories. There are many demands for the disclosure of this data for research and analysis to inform policy making. To expedite the disclosure of data for some of these purposes, the construction of a DAD public use microdata file (PUMF) was considered. Such purposes include: confirming some published results, providing broader feedback to CIHI to improve data quality, training students and fellows, providing an easily accessible data set for researchers to prepare for analyses on the full DAD data set, and serve as a large health data set for computer scientists and statisticians to evaluate analysis and data mining techniques. The objective of this study was to measure the probability of re-identification for records in a PUMF, and to de-identify a national DAD PUMF consisting of 10% of records.</p> <p>Methods</p> <p>Plausible attacks on a PUMF were evaluated. Based on these attacks, the 2008-2009 national DAD was de-identified. A new algorithm was developed to minimize the amount of suppression while maximizing the precision of the data. The acceptable threshold for the probability of correct re-identification of a record was set at between 0.04 and 0.05. Information loss was measured in terms of the extent of suppression and entropy.</p> <p>Results</p> <p>Two different PUMF files were produced, one with geographic information, and one with no geographic information but more clinical information. At a threshold of 0.05, the maximum proportion of records with the diagnosis code suppressed was 20%, but these suppressions represented only 8-9% of all values in the DAD. Our suppression algorithm has less information loss than a more traditional approach to suppression. Smaller regions, patients with longer stays, and age groups that are infrequently admitted to hospitals tend to be the ones with the highest rates of suppression.</p> <p>Conclusions</p> <p>The strategies we used to maximize data utility and minimize information loss can result in a PUMF that would be useful for the specific purposes noted earlier. However, to create a more detailed file with less information loss suitable for more complex health services research, the risk would need to be mitigated by requiring the data recipient to commit to a data sharing agreement.</p

    Connectivity of Elk Migration in Southwestern Alberta

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    ABSTRACT The purpose of this study was to investigate the migration of a partially migratory population of 650 Rocky Mountain elk (Cervus elaphus) in the human dominated landscape of southwestern Alberta. I contribute previously unknown values for metrics known to be important for elk ecology and management, including: migration timing, distance, and duration . The Brownian bridge movement model was used to delineate a probabilistic estimate of elk migration corridors between seasonal ranges, to determine if elk use stopovers during migration and prioritize migration corridors. Elk used a number of stopovers during migration likely to maximize areas of rich forage due to spring green-up. Stopovers were found to be >500m from roads in areas of rugged terrain These stopover locations are critical components in altitudinal migration. Finally a predictive modeling process using graph theory methods (least cost and circuit theory) was undertaken to predict connectivity of the landscape for elk
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