396 research outputs found
Continental Scale Modelling of Water Quality in Rivers
Global and continental scale modelling has been confined to water quantity (e.g. WaterGAP - Water Global Assessment and Prognosis (Alcamo et al. 2003), GWAVA - Global Water AVailability Assessment (Meigh et al, 1999)). Here we describe an approach to include water quality at these scales within the WaterGAP model. The application is to the pan-European area and is being carried out within the EU-funded SCENES Project which has the principal goal of developing new scenarios of the future of freshwater resources in Europe.
The model operates on 5x5 arc-minute grid squares. Water flows in and between grid cells are provided by WaterGAP. The water quality loadings into the river system comprise point sources (domestic effluent, manufacturing discharges and urban runoff) and diffuse sources (runoff from land and scattered settlements not connected to the public sewerage system). Point source loadings are calculated for each country using easily available datasets. For example, the domestic load is a per capita emission factor times by country population multiplied by the percentage of the population connected to the sewage system, which is then reduced by the amount removed in each of three types of sewage treatment (primary, secondary and tertiary). Data on the amount treated in different types of sewage works is set for each country, while the amount removed by treatment types will vary with the water quality variable being modelled. Country level data is converted to grid square data required by the model, according to the population in each grid square. Diffuse sources from land are calculated by regression models based on runoff and land use (e.g. numbers of livestock) for each model grid square.
The modelling system has currently been set up to simulate biochemical oxygen demand (BOD) and total dissolved solids. The model was tested against measured longitudinal profiles and time series data for BOD on contrasting rivers e.g. the River Thames (UK) driven by domestic loading and the River Ebro (Spain) with a high share of discharges from livestock farming. Further developments will see the inclusion of total nitrogen (TN), total phosphorus (TP) and dissolved oxygen.
Within the SCENES project a set of future scenarios reflecting different outlooks on Europe has been developed, called “Economy First”, “Fortress Europe”, “Sustainability Eventually” and “Policy Rules”. An Expert Panel was used to suggest what these futures would mean for drivers of water quantity and water quality across pan-Europe. We have projected how changes in percentage population connected to sewers, the level of sewage treatment and population would change loadings from domestic effluent for TN, TP and BOD. In time, these will be used to predict future water quality in European rivers
Mutant glycyl-tRNA synthetase (Gars) ameliorates SOD1G93A motor neuron degeneration phenotype but has little affect on Loa dynein heavy chain mutant mice
Background:
In humans, mutations in the enzyme glycyl-tRNA synthetase (GARS) cause motor and sensory axon loss in the peripheral nervous system, and clinical phenotypes ranging from Charcot-Marie-Tooth neuropathy to a severe infantile form of spinal muscular atrophy. GARS is ubiquitously expressed and may have functions in addition to its canonical role in protein synthesis through catalyzing the addition of glycine to cognate tRNAs.
Methodology/Principal findings:
We have recently described a new mouse model with a point mutation in the Gars gene resulting in a cysteine to arginine change at residue 201. Heterozygous Gars^{C201R/+} mice have locomotor and sensory deficits. In an investigation of genetic mutations that lead to death of motor and sensory neurons, we have crossed the Gars^{C201R/+} mice to two other mutants: the TgSOD1^{G93A} model of human amyotrophic lateral sclerosis and the Legs at odd angles mouse (Dync1h1^{Loa}) which has a defect in the heavy chain of the dynein complex. We found the Dync1h1^{Loa/+}; Gars^{C201R/+} double heterozygous mice are more impaired than either parent, and this is may be an additive effect of both mutations. Surprisingly, the Gars^{C201R} mutation significantly delayed disease onset in the SOD1^{G93A}; Gars^{C201R/+} double heterozygous mutant mice and increased lifespan by 29% on the genetic background investigated.
Conclusions/Significance:
These findings raise intriguing possibilities for the study of pathogenetic mechanisms in all three mouse mutant strains
Physiothérapie et douleur lombo-pelvienne chez la femme enceinte : Un appel à l’action
Travail d'intégration présenté à Isabelle Gagnon dans le cadre du cours PHT-6113.Problématique : La douleur lombo-pelvienne est une plainte fréquemment rencontrée chez la femme enceinte. Selon les études, l’incidence varie de 24% à 90%. Le mythe que la douleur lombo-pelvienne fait partie du processus normal de la grossesse et la croyance répandue qu’il n’y a rien à faire pour limiter les symptômes font en sorte que cette clientèle est sous-traitée par les physiothérapeutes.
Objectifs : Les objectifs du projet étaient 1) d’explorer la pratique clinique actuelle en physiothérapie ainsi que l’attitude des physiothérapeutes face à la prise en charge de femmes enceintes souffrant de douleurs lombo-pelviennes, 2) d’identifier la prise en charge optimale à préconiser et 3) d’élaborer des stratégies de transfert des connaissances acquises.
Méthodes : Un sondage a été effectué auprès de physiothérapeutes afin de déterminer la pratique clinique actuelle et leur sentiment de compétence face à cette clientèle. De plus, une recension des écrits concernant l’épidémiologie, les changements physiologiques, l’évaluation et le traitement en physiothérapie a été réalisée. Finalement, un site web visant les professionnels de la physiothérapie fut préparé.
Résultats : Des incertitudes quant aux précautions et contre-indications à prendre face à l’évaluation (19,7%), au traitement (40,3%) et à la prescription d’entrainement musculaire (25,2%) et cardio-vasculaire (35,1%) persistent chez un nombre important de physiothérapeutes. Lors de l’évaluation, il est particulièrement important de différencier les douleurs d’origine lombaire et pelvienne. Il semble y avoir des évidences sur l’efficacité des exercices en piscine ainsi que sur l’acuponcture pour traiter cette clientèle.
Conclusion : L’insuffisance d’évidences scientifiques ainsi que le manque de confiance des physiothérapeutes en ce qui concerne la pratique limitent la prise en charge optimale de cette clientèle
Complex taxonomy and global phylogeography of the well-known tropical earthworm Pontoscolex corethrurus
Few earthworm species are peregrine and among them, Pontoscolex corethrurus is the most well-known. Probably native from the Guyana shield, this earthworm is nowadays distributed worldwide, in the tropical and sub-tropical zones. It is found in a wide range of habitats, from apparently pristine to any kind of human-disturbed environments. P. corethrurus presents several characteristics of a successful invader: r-strategy, parthenogenesis reproduction and ecological and reproductive plasticity. Although its ecological interactions with the environment were well documented, the taxonomic status of this earthworm was unclear. We investigated the phylogenetic relationships within the genus Pontoscolex at a global scale (25 countries), focusing on morphologically indistinguishable lineages using the mitochondrial COI and 16S markers, the nuclear ITS 2 and 28S markers and a large-scale multilocus sequence data matrix obtained using the Anchored Hybrid Enrichment (AHE) phylogenomic method. Four cryptic species were discovered within the P. corethrurus species complex and one of them, P. corethrurus L1 was particularly widespread. Although sympatry between L1, L3 and L4 was observed, no case of hybridization was detected between L1 and the two other cryptic species, confirming the status of species of P. corethrurus L1. A population genetics study of this species using COI sequences and AFLP data revealed a low mitochondrial genetic diversity and a high proportion of clones in some populations, in accordance with the principal mode of reproduction of the species (i.e., parthenogenesis). However, variable levels of genetic diversity among populations and results of gametic disequilibrium analysis suggesting recombination in several populations, confirmed a mixed-mating strategy (sexual reproduction and parthenogenesis)
A comparison of statistically optimized near field acoustic holography using single layer pressure velocity measurements and using double layer pressure measurements
Statistically optimized near field acoustic holography using an array of pressure-velocity probes
Meta-analysis of gene–environment-wide association scans accounting for education level identifies additional loci for refractive error
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users will need to obtain permission from the license holder to reproduce the material.
To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/Myopia is the most common human eye disorder and it results from complex genetic and environmental causes. The rapidly increasing prevalence of myopia poses a major public health challenge. Here, the CREAM consortium performs a joint meta-analysis to test single-nucleotide polymorphism (SNP) main effects and SNP × education interaction effects on refractive error in 40,036 adults from 25 studies of European ancestry and 10,315 adults from 9 studies of Asian ancestry. In European ancestry individuals, we identify six novel loci (FAM150B-ACP1, LINC00340, FBN1, DIS3L-MAP2K1, ARID2-SNAT1 and SLC14A2) associated with refractive error. In Asian populations, three genome-wide significant loci AREG, GABRR1 and PDE10A also exhibit strong interactions with education (P<8.5 × 10(-5)), whereas the interactions are less evident in Europeans. The discovery of these loci represents an important advance in understanding how gene and environment interactions contribute to the heterogeneity of myopia
Overturning in the Subpolar North Atlantic Program: A New International Ocean Observing System
For decades oceanographers have understood the Atlantic meridional overturning circulation (AMOC) to be primarily driven by changes in the production of deep-water formation in the subpolar and subarctic North Atlantic. Indeed, current Intergovernmental Panel on Climate Change (IPCC) projections of an AMOC slowdown in the twenty-first century based on climate models are attributed to the inhibition of deep convection in the North Atlantic. However, observational evidence for this linkage has been elusive: there has been no clear demonstration of AMOC variability in response to changes in deep-water formation. The motivation for understanding this linkage is compelling, since the overturning circulation has been shown to sequester heat and anthropogenic carbon in the deep ocean. Furthermore, AMOC variability is expected to impact this sequestration as well as have consequences for regional and global climates through its effect on the poleward transport of warm water. Motivated by the need for a mechanistic understanding of the AMOC, an international community has assembled an observing system, Overturning in the Subpolar North Atlantic Program (OSNAP), to provide a continuous record of the transbasin fluxes of heat, mass, and freshwater, and to link that record to convective activity and water mass transformation at high latitudes. OSNAP, in conjunction with the Rapid Climate Change–Meridional Overturning Circulation and Heatflux Array (RAPID–MOCHA) at 26°N and other observational elements, will provide a comprehensive measure of the three-dimensional AMOC and an understanding of what drives its variability. The OSNAP observing system was fully deployed in the summer of 2014, and the first OSNAP data products are expected in the fall of 2017
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