69 research outputs found
A Standardized Workflow Based on the STAVIRO Unbaited Underwater Video System for Monitoring Fish and Habitat Essential Biodiversity Variables in Coastal Areas
Essential Biodiversity Variables (EBV) related to benthic habitats and high trophic levels such as fish communities must be measured at fine scale but monitored and assessed at spatial scales that are relevant for policy and management actions. Local scales are important for assessing anthropogenic impacts, and conservation-related and fisheries management actions, while reporting on the conservation status of biodiversity to formulate national and international policies requires much broader scales. Measurements must account for the fact that coastal habitats and fish communities are heterogeneously distributed locally and at larger scales. Assessments based on in situ monitoring generally suffer from poor spatial replication and limited geographical coverage, which is challenging for area-wide assessments. Requirements for appropriate monitoring comprise cost-efficient and standardized observation protocols and data formats, spatially scalable and versatile data workflows, data that comply with the FAIR (Findable, Accessible, Interoperable, and Reusable) principles, while minimizing the environmental impact of measurements. This paper describes a standardized workflow based on remote underwater video that aims to assess fishes (at species and community levels) and habitat-related EBVs in coastal areas. This panoramic unbaited video technique was developed in 2007 to survey both fishes and benthic habitats in a cost-efficient manner, and with minimal effect on biodiversity. It can be deployed in areas where low underwater visibility is not a permanent or major limitation. The technique was consolidated and standardized and has been successfully used in varied settings over the last 12 years. We operationalized the EBV workflow by documenting the field protocol, survey design, image post-processing, EBV production and data curation. Applications of the workflow are illustrated here based on some 4,500 observations (fishes and benthic habitats) in the Pacific, Indian and Atlantic Oceans, and Mediterranean Sea. The STAVIROβs proven track-record of utility and cost-effectiveness indicates that it should be considered by other researchers for future applications.publishedVersio
Commercial Nucleic-Acid Amplification Tests for Diagnosis of Pulmonary Tuberculosis in Respiratory Specimens: Meta-Analysis and Meta-Regression
BACKGROUND: Hundreds of studies have evaluated the diagnostic accuracy of nucleic-acid amplification tests (NAATs) for tuberculosis (TB). Commercial tests have been shown to give more consistent results than in-house assays. Previous meta-analyses have found high specificity but low and highly variable estimates of sensitivity. However, reasons for variability in study results have not been adequately explored. We performed a meta-analysis on the accuracy of commercial NAATs to diagnose pulmonary TB and meta-regression to identify factors that are associated with higher accuracy. METHODOLOGY/PRINCIPAL FINDINGS: We identified 2948 citations from searching the literature. We found 402 articles that met our eligibility criteria. In the final analysis, 125 separate studies from 105 articles that reported NAAT results from respiratory specimens were included. The pooled sensitivity was 0.85 (range 0.36-1.00) and the pooled specificity was 0.97 (range 0.54-1.00). However, both measures were significantly heterogeneous (p<.001). We performed subgroup and meta-regression analyses to identify sources of heterogeneity. Even after stratifying by type of commercial test, we could not account for the variability. In the meta-regression, the threshold effect was significant (p = .01) and the use of other respiratory specimens besides sputum was associated with higher accuracy. CONCLUSIONS/SIGNIFICANCE: The sensitivity and specificity estimates for commercial NAATs in respiratory specimens were highly variable, with sensitivity lower and more inconsistent than specificity. Thus, summary measures of diagnostic accuracy are not clinically meaningful. The use of different cut-off values and the use of specimens other than sputum could explain some of the observed heterogeneity. Based on these observations, commercial NAATs alone cannot be recommended to replace conventional tests for diagnosing pulmonary TB. Improvements in diagnostic accuracy, particularly sensitivity, need to be made in order for this expensive technology to be worthwhile and beneficial in low-resource countries
Combining local resources and mobile telephony to increase resort to care and reduce child mortality in Mali
In Mali, 1 child out of 6 does not reach the age of five. Most of these deaths could be avoided: children die mostly from untreated benign pathologies that could be easily cured locally. Though medical treatments are available in the local primary health centers, people resort too little and too late to healthcare, for cultural, financial and geographical reasons. Pesinet deploys an innovative health service that aims to drive prevention, detection and early-treatment of benign diseases. Agents make regular home visits to subscribed families in order to monitor the health of their children. They enter simple health data into a mobile phone and send it to the nearest medical center where the doctor reviews it and summons children at risk. This ongoing health monitoring system is combined with medical insurance at the local healthcare center. For a very affordable monthly fee, subscribing families benefit from the home visits, reductions on check-ups and medications, and education to prevention. This service is currently in operation in the city center of Bamako, and will be adapted for application in rural zones. Pesinet focuses on recourse to care by populations rather than on supply of new medical resources. By helping under-used primary health centers connect with populations, its objective is to generate a cultural change in the behaviors of populations and give health centers the capacity to improve the quality of the health services they offer. This paper intends to explain how this demand-driven approach could contribute to driving a sustainable change in the healthcare situation of Mali, and presents the promising results in terms of increase in resort to healthcare and local acceptability already encountered by the program
Estuaries as filters: the role of tidal marshes in trace metal removal.
Flux calculations demonstrate that many estuaries are natural filters for trace metals. Yet, the underlying processes are poorly investigated. In the present study, it was hypothesized that intertidal marshes contribute significantly to the contaminant filter function of estuaries. Trace metal concentrations and sediment characteristics were measured along a transect from the subtidal, over an intertidal flat and marsh to a restored marsh with controlled reduced tide. Metal concentrations in the intertidal and restored marsh were found to be a factor two to five higher than values in the subtidal and intertidal flat sediments. High metal concentrations and high accretion rates indicate a high metal accumulation capacity of the intertidal marshes. Overbank sedimentation in the tidal marshes of the entire estuary was calculated to remove 25% to 50% of the riverine metal influx, even though marshes comprise less than 8% of the total surface of the estuary. In addition, the large-scale implementation of planned tidal marsh restoration projects was estimated to almost double the trace metal storage capacity of the present natural tidal marshes in the estuary
Identification of potential serum biomarkers of inflammation and lipid modulation that are altered by fish oil supplementation in healthy volunteers
Long chain n-3 polyunsaturated fatty acids (n-3 LCPUFA) lower risk of coronary heart disease (CHD), but mechanisms are not well understood. We used proteomics to identify human serum proteins that are altered by n-3 LCPUFA. Such proteins could identify pathways whereby they affect CHD. Eighty-one healthy volunteers entered a double blind randomised trial to receive 3.5β
g of fish oil or 3.5β
g of high oleic sunflower oil daily. Serum was collected before and after 6β
wk of intervention. Serum was analysed by proteomics using 2-DE. Proteins that were differentially regulated were identified by MS. We also analysed serum apolipoprotein A1 (apo A1), high-density lipoprotein (HDL) particle size and haptoglobin. Serum levels of apo A1, apo L1, zinc-Ξ±-2-glycoprotein, haptoglobin precursor, Ξ±-1-antitrypsin precursor, antithrombin III-like protein, serum amyloid P component and haemopexin were significantly downregulated (all p<0.05) by fish oil compared with high oleic sunflower oil supplementation. Fish oil supplementation caused a significant shift towards the larger, more cholesterol-rich HDL2 particle. The alterations in serum proteins and HDL size imply that fish oil activates anti-inflammatory and lipid modulating mechanisms believed to impede the early onset of CHD. These proteins are potential diagnostic biomarkers to assess the mechanisms whereby fish oil protects against CHD in humans
Modeling physical quantities of food and nutrients consumed from aggregate data-with an application to Finland
Anticipating the impact of changes in economic incentives on dietary quality and nutritional health requires knowledge of how physical quantities of food consumed respond to price and income variations. A problem arises, however, because physical quantities are: (1) not consistent aggregates in demand models; and (2) not measured at final/retail level in national statistics. The article develops a solution by establishing explicitly the theoretical link between composite demand and physical quantities, from which a novel empirical approach to the estimation of nutrient elasticities is derived. It is applied to Finnish aggregate data from the National Accounts and Food Balance Sheets over the 1975-2006 period, and the results are used to assess the potential effectiveness of several incentive-based nutritional policy instruments. Copyright (c) 2010 International Association of Agricultural Economists.
Rho GTPases dictate the mobility of the Na/H exchanger NHE3 in epithelia: Role in apical retention and targeting
Proximal tubular reabsorption of filtered sodium by the sodium/hydrogen exchanger isoform 3 (NHE3), located on the apical membrane, is fundamental to the maintenance of systemic volume and pH homeostasis. NHE3 is finely regulated by a variety of hormones and by changes in ionic composition and volume, likely requiring redistribution of the exchangers. We analyzed the subcellular distribution and dynamics of the exchangers by generating an epithelial line expressing NHE3 tagged with an exofacial epitope, which enabled us to monitor exchanger mobility and traffic in intact cells. Using determinations of fluorescence recovery after photobleaching in combination with dynamic measurements of subcellular distribution, we found that, in renal epithelial cells, NHE3 exists in four distinct subcompartments: a virtually immobile subpopulation that is retained on the apical membrane by interaction with the actin cytoskeleton in a manner that depends on the sustained activity of Rho GTPases; a mobile subpopulation on the apical membrane, which can be readily internalized; and two intracellular compartments that can be differentiated by their rate of exchange with the apical pool of NHE3. We provide evidence that detachment of the immobile fraction from its cytoskeletal anchorage leads to rapid internalization. These observations suggest that modulation of the mobile fraction of NHE3 on the apical membrane can alter the number of functional exchangers on the cell surface and, consequently, the rate of transepithelial ion transport. Regulation of the interaction of NHE3 with the actin cytoskeleton can therefore provide a new mode of regulation of sodium and hydrogen transport
Sediment and metal deposition.
<p>Box plots (median, 25<sup>th</sup>, 75<sup>th</sup> percentile and standard deviation) of seasonal difference in deposited sediments (A) and deposited Cd (B) in a tidal marsh and restored marsh (CRT).</p
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