290 research outputs found

    Vegetation and environmental patterns on soils derived from Hawkesbury Sandstone and Narrabeen substrata in Ku-ring-gai Chase National Park, New South Wales

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    [Abstract]: The vegetation patterns in the Central Coast region of New South Wales have been extensively studied with respect to single environmental variables, particularly soil nutrients. However, few data are available on the effects of multiple environmental variables. This study examines the relationships between vegetation and multiple environmental variables in natural vegetation on two underlying rock types, Hawkesbury sandstone and Narrabeen group shales and sandstones, in Ku-ring-gai Chase National Park, Sydney. Floristic composition and 17 environmental factors were characterized using duplicate 500 m2 quadrats from fifty sites representing a wide range of vegetation types. The patterns in vegetation and environmental factors were examined through multivariate analyses: indicator species analysis was used to provide an objective classification of plant community types, and the relationships between vegetation and environmental factors within the two soil types were examined through indirect and direct gradient analyses. Eleven plant communities were identified, which showed strong agreement with previous studies. The measured environmental factors showed strong correlations with vegetation patterns: within both soil types, the measured environmental variables explained approximately 32 - 35% of the variation in vegetation. No single measured environmental variable adequately described the observed gradients in vegetation; rather, vegetation gradients showed strong correlations with complex environmental gradients. These complex environmental gradients included nutrient, moisture and soil physical and site variables. These results suggest a simple 'nutrient' hypothesis regarding vegetation patterns in the Central Coast region is inadequate to explain variation in vegetation within soil types

    The I3a Framework – Enhancing Off-grid Photovoltaic Energy Service Delivery in Indonesia

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    This paper describes an interdisciplinary research project to investigate the sustainability of off-grid Photovoltaic Energy Service (PVES) delivery in Indonesia. The paper describes results from the preliminary fieldwork undertaken in late 2002 and early 2003, more substantive fieldwork was carried out in 2005. The general objective of this research project is to understand how PVES can contribute to improving the life of rural Indonesian communities having no access to the electricity grid. It adopts an interdisciplinary approach that combines social and engineering perspectives to address sustainability issues. The I3A (Implementation, Accessibility, Availability, Acceptability) Sustainable PVES Delivery framework was developed to assess sustainability and was used to assess three off-grid PVES case studies in Lampung, West Java and Nusa Tenggara Timur (NTT) provinces. The overall objectives of the I3A framework are to acknowledge the interests of stakeholders, maximize equity, assure PVES continuity and institutionalize PVES by utilizing and enhancing pre-existing community resources to leave host communities with the capacity to meet evolving needs. A key conclusion is that, to be sustainable and equitable, off-grid PVES projects should be implemented in an institutional framework that provides sound project management and addresses PVES accessibility (financial, institutional and technological), availability (technical quality and continuity) and acceptability (social and ecological)

    Diagnosing tuberculosis in the 21st century – Dawn of a genomics revolution?

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    Tuberculosis (TB) ranks alongside HIV as the leading cause of death worldwide, killing 1.5 million people in 2014. Traditional laboratory techniques do not provide sufficiently rapid results to inform clinicians on appropriate treatment, especially in the face of increasingly prevalent drug-resistant TB. Rapid molecular methods such as PCR and LAMP are vital tools in the fight against TB, however, rapid advances in next generation sequencing (NGS) technology are allowing increasingly rapid and accurate sequencing of entire bacterial genomes at ever decreasing cost, providing unprecedented depth of information. These advances mean NGS stands to revolutionise the diagnosis and epidemiological study of Mycobacterium tuberculosis infection. This review focuses on current applications of NGS for TB diagnosis including sequencing cultured isolates to predict drug resistance and, more desirably, direct diagnostic metagenomic sequencing of clinical samples. Also discussed is the potential impact of NGS on the epidemiological study of TB and some of the key challenges that need to be overcome to enable this promising technology to be translated into routine use

    Non-linear analysis of the heart rate variability in characterization of manic and euthymic phases of bipolar disorder

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    Background: - Bipolar Disorder (BD) has been associated with autonomic nervous system (ANS) dysregulation, with a consequent increase in mortality. Recent work highlights the non-linear analysis of ANS function. Our objective was to compare ANS modulation using recurrence plots (RP) and symbolic analysis (SA) in manic and euthymic phases of BD to controls. Methods: - Eighteen male patients (33.1 \ub1 12.0 years) were assessed during mania and at discharge in the euthymic phase compared and to a healthy group matched by age (33.9 \ub1 10.8 years). Electrocardiographic series (1000 RR intervals, at rest, in supine position) were captured using Polar Advantage RS800CX equipment and Heart Rate Variability (HRV) was analysed using RP and SA. Statistical analysis was performed using ANOVA with Tukey's post-test. The threshold for statistical significance was set at P < 0.05 and Cohen's d effect size was also quantified considering d > 0.8 as an important effect. The study was registered into the Clinical Trials Registration (ClinicalTrials.gov: NCT01272518). Results: Manic group presented significantly higher linearity before treatment (P<0.05) compared to controls considering RP variables. Cohen's d values had a large effect size ranging from 0.888 to 1.227. In the manic phase, SA showed predominance of the sympathetic component (OV%) with reduction of the parasympathetic component (2LV% and 2UV%) with reversion post treatment including higher Shannon Entropy (SE) indicating higher complexity. Limitations: - short follow-up (1 month) and small number of patients. Conclusions: - Non-linear analyzes may be used as supplementary tools for understanding autonomic function in BD during mania and after drug treatment

    Policy making and energy infrastructure change: A Nigerian case study of energy governance in the electricity sector

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    This paper focusses on investigating the underlying mechanisms and influences of the policy decision making process and how it affects and impacts the governance of the Nigerian energy industry, and energy infrastructure provisions. In-depth semi-structured interviews were used; all interviewees had been involved, directly or indirectly, in energy infrastructure policy decisions in Nigeria. Five key themes subsequently emerged as salient intra-country induced influences that were affecting the governance and performance of the Nigerian energy sector: (1) competencies – i.e. practical knowledge of energy policy making; (2) expectations – i.e. past, present, and forecasted future expectations from the energy industry; (3) legislation – i.e. institutionalized (and unwritten) rules/procedures; (4) future visions – i.e. future vision of the energy industry/energy market; (5) recruiting experts – i.e. recruiting new energy and public policy makers. In addition, three major inter-country induced influences were also identified: (1) the changing dynamics of international and foreign aid; (2) the United Nations Sustainable Development Goals; and (3) the Paris Agreements on Climate Change. The paper concludes by highlighting the policy implications of these influences, and the consequences for policy makers in the governance of the energy industry in ensuring a secured energy future

    Clinical use of Whole Genome Sequencing for Mycobacterium tuberculosis

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    Drug resistant tuberculosis (TB) remains a major challenge to global health and to healthcare in the UK. In 2014, England recorded 6520 cases of TB of which 1.4% were multi-drug resistant (MDR-TB). Extensively drug resistant TB (XDR-TB) occurs at a much lower rate, but the impact on the patient and hospital is severe. Current diagnostic methods such as drug susceptibility testing and targeted molecular tests are slow to return or examine only a limited number of target regions respectively. Faster, more comprehensive diagnostics will enable earlier use of the most appropriate drug regimen thus improving patient outcome and reducing overall healthcare costs. Whole genome sequencing has been shown to provide a rapid and comprehensive view of the genotype of the organism and thus enable reliable prediction of the drug susceptibility phenotype within a clinically relevant time frame. In addition it provides the highest resolution when investigating transmission events in possible outbreak scenarios. However, robust software and database tools need to be developed for the full potential to be realized in this specialized area of medicine
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