2,475 research outputs found

    Validation and analysis of MOPITT CO observations of the Amazon Basin

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    We analyze satellite retrievals of carbon monoxide from the MOPITT (Measurements of Pollution in the Troposphere) instrument over the Amazon Basin, focusing on the MOPITT Version 6 "multispectral" retrieval product (exploiting both thermal-infrared and near-infrared channels). Validation results based on in situ vertical profiles measured between 2010 and 2013 are presented for four sites in the Amazon Basin. Results indicate a significant negative bias in retrieved lower-tropospheric CO concentrations. The possible influence of smoke aerosol as a source of retrieval bias is investigated using collocated Aerosol Robotic Network (AERONET) aerosol optical depth (AOD) measurements at two sites but does not appear to be significant. Finally, we exploit the MOPITT record to analyze both the mean annual cycle and the interannual variability of CO over the Amazon Basin since 2002

    Developing a new version of the SF-6D health state classification system from the SF-36v2: SF-6Dv2

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    Objective: The objective of this study was to develop the classification system for version of the SF-6D (SF-6Dv2) from the SF-36v2. SF-6Dv2 is an improved version of SF-6D, one of the most widely used generic measures of health for the calculation of quality-adjusted life years. Study Design and Setting: A 3-step process was undertaken to generate a new classification system: (1) factor analysis to establish dimensionality; (2) Rasch analysis to understand item performance; and (3) tests of differential item function. To evaluate robustness, Rasch analyses were performed in multiple subsets of 2 large cross-sectional datasets from recently discharged hospital patients and online patient samples. Results: On the basis of factor analysis, other psychometric evidence, cross-cultural considerations, and amenability to valuation, the 6-dimension classification used in SF-6D was maintained. SF-6Dv2 resulted in the following modifications to SF-6D: a simpler classification of physical function with clearer separation between levels; a more detailed 5-level description of role limitations; using negative wording to describe vitality; and using pain severity rather than pain interference. Conclusions: The SF-6Dv2 classification system describes more distinct levels of health than SF-6D, changes the descriptions used for a number of dimensions and provides clearer wording for health state valuation. The second stage of the study has developed a utility value set using discrete choice methods so that the measure can be used in health technology assessment. Further work should investigate the psychometric characteristics of the new instrument

    Maximising the benefits of renewable energy infrastructure in displacement settings: optimising the operation of a solar-hybrid mini-grid for institutional and business users in Mahama Refugee Camp, Rwanda

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    Humanitarian organisations typically rely on expensive, polluting diesel generators to provide power for services in refugee camps, whilst camp residents often have no access to electricity. Integrating solar and battery storage capacity into existing diesel-based systems can provide significant cost and emissions savings and offer an opportunity to provide power to displaced communities. By analysing monitored demand data and using computational energy system modelling, we assess the savings made possible by the integration of solar (18.4 kWp) and battery (78 kWh) capacity into the existing diesel-powered mini-grid in Mahama Refugee Camp, Rwanda. We find that the renewables infrastructure reduces fuel expenditure by 41,500andemissionsby44tCO2eq(both7441,500 and emissions by 44 tCO2eq (both 74%) over five years under the generator’s current operational strategy. An alternative strategy, with deeper battery cycling, unlocks further savings of 4100 and 12.4 tCO2eq, using 33% of battery lifetime versus 15% under the original strategy. This reduces the cost of electricity by 33% versus diesel generation alone, whilst more aggressive cycling strategies could prove economical if moderate battery price decreases are realised. Extending the system to businesses in the camp marketplace can completely offset the system fuel costs if the mini-grid company charges customers the same tariff as the one it uses in the host community, but not the national grid tariff. Humanitarian organisations and the private sector should explore opportunities to integrate renewables into existing diesel-based infrastructure, and optimise its performance once installed, to reduce costs and emissions and provide meaningful livelihood opportunities to displaced communities

    Metrics to evaluate research performance in academic institutions: A critique of ERA 2010 as applied in forestry and the indirect H2 index as a possible alternative

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    Excellence for Research in Australia (ERA) is an attempt by the Australian Research Council to rate Australian universities on a 5-point scale within 180 Fields of Research using metrics and peer evaluation by an evaluation committee. Some of the bibliometric data contributing to this ranking suffer statistical issues associated with skewed distributions. Other data are standardised year-by-year, placing undue emphasis on the most recent publications which may not yet have reliable citation patterns. The bibliometric data offered to the evaluation committees is extensive, but lacks effective syntheses such as the h-index and its variants. The indirect H2 index is objective, can be computed automatically and efficiently, is resistant to manipulation, and a good indicator of impact to assist the ERA evaluation committees and to similar evaluations internationally.Comment: 19 pages, 6 figures, 7 tables, appendice

    Core components for effective infection prevention and control programmes: new WHO evidence-based recommendations

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    Abstract Health care-associated infections (HAI) are a major public health problem with a significant impact on morbidity, mortality and quality of life. They represent also an important economic burden to health systems worldwide. However, a large proportion of HAI are preventable through effective infection prevention and control (IPC) measures. Improvements in IPC at the national and facility level are critical for the successful containment of antimicrobial resistance and the prevention of HAI, including outbreaks of highly transmissible diseases through high quality care within the context of universal health coverage. Given the limited availability of IPC evidence-based guidance and standards, the World Health Organization (WHO) decided to prioritize the development of global recommendations on the core components of effective IPC programmes both at the national and acute health care facility level, based on systematic literature reviews and expert consensus. The aim of the guideline development process was to identify the evidence and evaluate its quality, consider patient values and preferences, resource implications, and the feasibility and acceptability of the recommendations. As a result, 11 recommendations and three good practice statements are presented here, including a summary of the supporting evidence, and form the substance of a new WHO IPC guideline

    Collective Animal Behavior from Bayesian Estimation and Probability Matching

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    Animals living in groups make movement decisions that depend, among other factors, on social interactions with other group members. Our present understanding of social rules in animal collectives is based on empirical fits to observations and we lack first-principles approaches that allow their derivation. Here we show that patterns of collective decisions can be derived from the basic ability of animals to make probabilistic estimations in the presence of uncertainty. We build a decision-making model with two stages: Bayesian estimation and probabilistic matching.
In the first stage, each animal makes a Bayesian estimation of which behavior is best to perform taking into account personal information about the environment and social information collected by observing the behaviors of other animals. In the probability matching stage, each animal chooses a behavior with a probability given by the Bayesian estimation that this behavior is the most appropriate one. This model derives very simple rules of interaction in animal collectives that depend only on two types of reliability parameters, one that each animal assigns to the other animals and another given by the quality of the non-social information. We test our model by obtaining theoretically a rich set of observed collective patterns of decisions in three-spined sticklebacks, Gasterosteus aculeatus, a shoaling fish species. The quantitative link shown between probabilistic estimation and collective rules of behavior allows a better contact with other fields such as foraging, mate selection, neurobiology and psychology, and gives predictions for experiments directly testing the relationship between estimation and collective behavior

    Predicting mental imagery based BCI performance from personality, cognitive profile and neurophysiological patterns

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    Mental-Imagery based Brain-Computer Interfaces (MI-BCIs) allow their users to send commands to a computer using their brain-activity alone (typically measured by ElectroEncephaloGraphy— EEG), which is processed while they perform specific mental tasks. While very promising, MI-BCIs remain barely used outside laboratories because of the difficulty encountered by users to control them. Indeed, although some users obtain good control performances after training, a substantial proportion remains unable to reliably control an MI-BCI. This huge variability in user-performance led the community to look for predictors of MI-BCI control ability. However, these predictors were only explored for motor-imagery based BCIs, and mostly for a single training session per subject. In this study, 18 participants were instructed to learn to control an EEG-based MI-BCI by performing 3 MI-tasks, 2 of which were non-motor tasks, across 6 training sessions, on 6 different days. Relationships between the participants’ BCI control performances and their personality, cognitive profile and neurophysiological markers were explored. While no relevant relationships with neurophysiological markers were found, strong correlations between MI-BCI performances and mental-rotation scores (reflecting spatial abilities) were revealed. Also, a predictive model of MI-BCI performance based on psychometric questionnaire scores was proposed. A leave-one-subject-out cross validation process revealed the stability and reliability of this model: it enabled to predict participants’ performance with a mean error of less than 3 points. This study determined how users’ profiles impact their MI-BCI control ability and thus clears the way for designing novel MI-BCI training protocols, adapted to the profile of each user

    Níveis de calcidiol e manutenção da função muscular, capacidade funcional e densidade mineral óssea em uma população espanhola não selecionada.

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    Introduction: Vitamin D has beneficial effects that supposedly contribute to the maintenance of musculoskeletal function. Objective: To analyze in an unselected population the effect of calcidiol levels on the muscular function of both hands, on the activities of daily living and on changes in bone mineral density (BMD). Material and methods: The cohort of the EVOS study was used, which performed, among others, measurements of muscle strength of grasping both hands, questions related to the difficulty in performing daily activities, densitometric study of the lumbar and hip spine and biochemistry for determination calcidiol levels. Results: Calcidiol values ​​≥20 ng / mL were associated with increased grip muscle strength in both hands. After adjusting for age, sex, BMI and seasonality, calcidiol levels <20 ng / mL were independently associated with decreased muscle grip strength only in the left hand (OR = 2.35, 95% CI 1.03 -5, 38) Likewise, the inability or difficulty in "picking up a book or object on a high shelf" and "getting out of bed" was significantly associated with calcidiol levels <20 ng / mL. Calcidiol levels <20 ng / mL were associated with greater losses of BMD in the femoral neck and in the total hip. These associations were maintained in the multivariate analysis. Conclusions: The maintenance of calcidiol levels ≥20 ng / mL was associated with greater muscle grip strength in the hands, maintenance of daily activities and less loss of BMD in the hip. This study corroborates the usefulness of maintaining adequate levels of vitamin D to maintain musculoskeletal function.Introdução: A vitamina D tem efeitos benéficos que supostamente contribuem para a manutenção da função músculo-esquelética. Objetivo: Analisar em uma população não selecionada o efeito dos níveis de calcidiol na função muscular de ambas as mãos, nas atividades da vida diária e nas alterações na densidade mineral óssea (DMO). Material e métodos: Utilizou-se a coorte do estudo EVOS, que realizou, entre outras, medidas de força muscular de preensão nas duas mãos, questões relacionadas à dificuldade na realização das atividades diárias, estudo densitométrico da coluna lombar e quadril e bioquímica para determinação dos níveis de calcidiol. Resultados: Valores de calcidiol ≥20 ng / mL foram associados ao aumento da força muscular de preensão em ambas as mãos. Após o ajuste para idade, sexo, IMC e sazonalidade, os níveis de calcidiol <20 ng / mL foram associados de forma independente à diminuição da força de preensão muscular apenas na mão esquerda (OR = 2,35, IC 95% 1,03-5, 38) Da mesma forma, a incapacidade ou dificuldade em "pegar um livro ou objeto em uma prateleira alta" e "sair da cama" foi significativamente associada a níveis de calcidiol <20 ng / mL. Níveis de calcidiol <20 ng / mL foram associados a maiores perdas de DMO no colo do fêmur e no quadril total. Essas associações foram mantidas na análise multivariada. Conclusões: A manutenção de níveis de calcidiol ≥20 ng / mL foi associada a maior força de preensão muscular nas mãos, manutenção das atividades diárias e menor perda de DMO no quadril. Este estudo corrobora a utilidade de manter níveis adequados de vitamina D para manter a função músculo-esquelética

    Sleep-wake sensitive mechanisms of adenosine release in the basal forebrain of rodents : an in vitro study

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    Adenosine acting in the basal forebrain is a key mediator of sleep homeostasis. Extracellular adenosine concentrations increase during wakefulness, especially during prolonged wakefulness and lead to increased sleep pressure and subsequent rebound sleep. The release of endogenous adenosine during the sleep-wake cycle has mainly been studied in vivo with microdialysis techniques. The biochemical changes that accompany sleep-wake status may be preserved in vitro. We have therefore used adenosine-sensitive biosensors in slices of the basal forebrain (BFB) to study both depolarization-evoked adenosine release and the steady state adenosine tone in rats, mice and hamsters. Adenosine release was evoked by high K+, AMPA, NMDA and mGlu receptor agonists, but not by other transmitters associated with wakefulness such as orexin, histamine or neurotensin. Evoked and basal adenosine release in the BFB in vitro exhibited three key features: the magnitude of each varied systematically with the diurnal time at which the animal was sacrificed; sleep deprivation prior to sacrifice greatly increased both evoked adenosine release and the basal tone; and the enhancement of evoked adenosine release and basal tone resulting from sleep deprivation was reversed by the inducible nitric oxide synthase (iNOS) inhibitor, 1400 W. These data indicate that characteristics of adenosine release recorded in the BFB in vitro reflect those that have been linked in vivo to the homeostatic control of sleep. Our results provide methodologically independent support for a key role for induction of iNOS as a trigger for enhanced adenosine release following sleep deprivation and suggest that this induction may constitute a biochemical memory of this state
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