92 research outputs found

    Can groundwater secure drinking-water supply and supplementary irrigation in new settlements of North-West Cambodia ?

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    Since the end of the Cambodian Civil War in 1998, the population of the Oddar Meanchey province has drastically increased despite the lack of adequate infrastructure, including basic amenities such as drinking-water supply. To improve the access to drinking water, governmental and aid agencies have focussed on drilling shallow boreholes. The use of groundwater for irrigation is also a growing concern to cope with the occasional late arrival of the rainy season or to produce food during the dry season. Since the groundwater resource in the province has not been documented, a 4-year study was undertaken (2011-2014), aiming to estimate the capability of groundwater to supply domestic needs and supplementary irrigation for rice production. Aquifer properties were estimated by combined use of hydrogeological techniques with the geophysical magnetic resonance sounding method. Groundwater storage and recharge were estimated based on new developments in the application of the geophysical method for quantifying specific yield. The median groundwater storage of the targeted sandstone aquifer is 173 mm, the recharge is diffuse and annually ranges from 10 to 70 mm, and the transmissivity is low to medium. Simulations of pumping indicate that the aquifer can easily supply 100 L of drinking water per capita daily, even considering the estimated population in 2030. However, the shallow aquifer can generally not deliver enough water to irrigate paddy fields of several hectares during a 2-month delay in the onset of the monsoon

    Methylation-associated PHOX2B gene silencing is a rare event in human neuroblastoma.

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    International audienceNeuroblastoma (NB), an embryonic tumour originating from neural crest cells, is one of the most common solid tumours in childhood. Although NB is characterised by numerous recurrent, large-scale chromosome rearrangements, the genes targeted by these imbalances have remained elusive. We recently identified the paired-like homeobox 2B (PHOX2B, MIM 603851) gene as disease-causing in dysautonomic disorders including Congenital Central Hypoventilation Syndrome (CCHS), Hirschsprung disease (HSCR) and NB in various combinations. Most patients with NB due to a germline heterozygous PHOX2B gene mutation are familial and/or syndromic. PHOX2B, at chromosome 4p12, does not lie in a commonly rearranged locus in NB. To evaluate the role of PHOX2B in sporadic, isolated NB, we analysed 13 NB cell lines and 45 tumours for expression, mutations of coding and promoter sequences, loss of heterozygosity (LOH), or aberrant hypermethylation of PHOX2B (13 cell lines and 18 tumours). We didn't identify any mutation but LOH in about 10% of the cases and aberrant CpG dinucleotide methylation of the 500 bp PHOX2B promoter region in 4/31 tumours and cell lines (12.9%). Altogether, both germinal and somatic anomalies at the PHOX2B locus are found in NB

    APPORTS D'UNE CONCEPTION ORIENTEE OBJET A LA RESOLUTION NUMERIQUE DES EQUATIONS DE MAXWELL DANS LE CADRE D'UNE METHODOLOGIE DE FACTORISATION

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    PARIS-BIUSJ-Mathématiques rech (751052111) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocSudocFranceF

    Étude de la posture et de la transmission biomécanique des vibrations chez le guitariste électrique.

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    International audienceÉtude de la posture et de la transmission biomécanique des vibrations chez le guitariste électrique

    Towards a better estimate of storage properties of aquifer with magnetic resonance sounding

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    Providing people with fresh water is one of the greatest challenges of the century. Since most of the world's liquid fresh water is groundwater, the knowledge of aquifer storage properties is essential. Moreover, there is a need to focus research on poor aquifers (i.e. capable of providing about 100 m(3)/day) which will play an increasing role for supplying many human communities. This paper concerns a study carried out in a clayey sandstones aquifer in Northern Cambodia. Conventional hydraulic methods used to characterize aquifers are costly, time-consuming and thus they are usually not used in most of the water projects in developing countries. Therefore, geophysical methods can be useful if they improve aquifer characterization. As compared to other non-invasive geophysical methods, magnetic resonance sounding (MRS) is selective to groundwater. MRS results are the distribution of both water content and pore-size related-parameters as a function of depth. However, relationships between the field scale MRS results and hydrogeological storage-related properties have not been well established yet. We present in this paper a comparison of MRS results with both specific yield calculated from pumping tests and effective porosity calculated from tracer tests. We found that the MRS water content is equal or higher than the specific yield and the effective porosity, thus indicating that MRS also measures capillary water in unsaturated zone and part of the bound groundwater attached to the aquifer solid matrix. We also found that the MRS pore-size parameter is linearly correlated with both the effective porosity and the specific yield, thus suggesting that the hydrogeological storage properties are mainly controlled by the size of the pores of the aquifer. Consequently, we adapted an approach used in the oil industry for differencing gravitational water from capillary water and from bound water, based on the MRS pore-size parameter. In the clayey sandstones of Cambodia, our approach named MRS apparent cutoff time approach, allowed calculating specific yield with an average error of 23% (which is far less than the previous published results), and for the first time it allowed calculating effective porosity (with an average error of 11%). We conclude that the MRS apparent cutoff time approach is useful for estimating aquifer storage properties down to 50-80 m deep, in a single day and at an affordable cost

    Cross-Sectional Evaluation of Surface Contamination with Antineoplastic Drugs in Canadian Health Care Centres

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    ABSTRACTBackground: Surfaces in health care centres are often contaminated with traces of antineoplastic drugs. Such contamination should be limited as much as possible, to reduce workers’ exposure.Objectives: The primary objective was to monitor environmental contamination with 9 antineoplastic drugs in oncology pharmacy and patient care areas of Canadian health care centres. The secondary objective was to explore the use of sodium hypochlorite as a cleaning agent for cyclophosphamide contamination. Methods: This cross-sectional evaluation was conducted from January to April 2018. Twelve standardized sites were sampled at each participating centre: 6 in the oncology pharmacy and 6 in patient care areas. Six of the antineoplastic drugs (cyclophosphamide, ifosfamide, methotrexate, gemcitabine, 5-fluorouracil, and irinotecan) were quantified by ultra-performance liquid chromatography – tandem mass spectrometry. For the other 3 antineoplastic drugs (docetaxel, paclitaxel, and vinorelbine), samples were screened for contamination but not quantified. The effect of using sodium hypochlorite as a cleaning agent was evaluated with a Kolmogorov-Smirnov test for independent samples.Results: Of 202 Canadian centres invited, 79 participated. A total of 887 surface samples were analyzed, 467 from pharmacy areas and 420 from patient care areas. Cyclophosphamide was the drug most often found as a contaminant (32.2% [286/887] of samples positive, 75th percentile of measured contamination 0.0017 ng/cm², 90th percentile 0.021 ng/cm²). The front grille inside the hood (80.8% [63/78] of samples positive for at least one antineoplastic drug), treatment chair armrest (78.9% [60/76]), storage shelf in pharmacy (61.5% [48/78]), and floor in front of the hood (60.3% [47/78]) were the most frequently contaminated surfaces. Cleaning with a sodium hypochlorite solution was highly variable. Among centres that reported using sodium hypochlorite to clean armrests on patient chairs, the concentration of cyclophosphamide was lower (0.00866 versus 0.0300 ng/cm², p = 0.014). Conclusions: Despite growing awareness and implementation of new safe-handling guidelines, surfaces in health care centres were contaminated with traces of many antineoplastic drugs. Providing centres with attainable goals (e.g., 75th to 90th percentile relative to other similar centres) would help in identifying the sampling sites where improvements are needed and in achieving lower surface contamination.RÉSUMÉContexte : Les surfaces dans les centres de santé sont souvent contaminées par des traces de médicaments antinéoplasiques. Une telle contamination devrait être limitée autant que faire se peut afin de réduire l’exposition des employés à ces produits.Objectifs : L’objectif principal consistait à mesurer la contamination environnementale provenant de neuf médicaments antinéoplasiques dans la section de la pharmacie oncologique et celle des soins offerts aux patients dans des centres de soins de santé canadiens. L’objectif secondaire consistait à explorer l’action nettoyante de l’hypochlorite de sodium pour éliminer la contamination par la cyclophosphamide. Méthodes : Cette évaluation transversale a été menée de janvier à avril 2018. Des échantillons ont été prélevés dans douze endroits standardisés de chaque centre participant : six dans la section de la pharmacie oncologique et six dans celle des soins donnés aux patients. La présence de six des médicaments antinéoplasiques examinés (cyclophosphamide, ifosfamide, méthotrexate, gemcitabine, 5-fluorouracil et irinotécan) a été quantifiée par chromatographie liquide à haute performance (HPLC) avec spectrométrie de masse en tandem. Quant aux trois autres échantillons de médicaments antinéoplasiques (docetaxel, paclitaxel et vinorelbine), ils ont été analysés pour rechercher la présence d’une contamination qui n’a pas été quantifiée. L’action nettoyante de l’hypochlorite de sodium a été évaluée à l’aide d’un test de Kolmogorov-Smirnov pour les échantillons indépendants.Résultats : Sur 202 centres canadiens invités à participer à l’étude, 79 ont répondu à l’invitation. L’analyse a porté sur 887 échantillons de surfaces des lieux sélectionnés : 467 dans la section de la pharmacie et 420 dans la section des soins donnés aux patients. La cyclophosphamide était le médicament contaminant le plus souvent décelé (32,2 % d’échantillons positifs [286/887], 75e percentile de contamination mesurée 0,0017 ng/cm², 90e percentile 0,021 ng/cm²). La grille frontale à l’intérieur de la hotte de laboratoire (80,8 % des échantillons [63/78] étaient positifs pour au moins un médicament antinéoplasique), l’accoudoir de la chaise du patient (78,9 % [60/76]), l’étagère de stockage dans la pharmacie (61,5 % [48/78]) et le sol en face de la hotte (60,3%[47/78]) étaient les surfaces le plus souvent contaminées. L’usage d’une solution d’hypochlorite de sodium pour le nettoyage variait grandement d’un centre à l’autre. Dans les centres qui indiquaient utiliser cet agent pour nettoyer les accoudoirs des chaises du patient, la concentration de cyclophosphamide sur les accoudoirs était moins élevée (0,00866 contre 0,0300 ng/cm², p = 0,014). Conclusions : Malgré la prise de conscience et la mise en place croissantes de nouvelles lignes directrices en matière de manipulation sécuritaire, les surfaces de certains endroits des centres de santé sont contaminées par des traces de nombreux médicaments antinéoplasiques. La fixation d’objectifs atteignables pour les centres (p. ex., entre le 75e et le 90e percentile par rapport aux autres centres similaires) aide à déterminer les sites d’échantillonnage où des améliorations sont nécessaires et à diminuer la contamination des surfaces.

    IL-2 requirement for human plasma cell generation: coupling differentiation and proliferation by enhancing MAPK-ERK signaling.

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    International audienceMature B cell differentiation involves a well-established transcription factor cascade. However, the temporal dynamics of cell signaling pathways regulating transcription factor network and coordinating cell proliferation and differentiation remain poorly defined. To gain insight into the molecular processes and extrinsic cues required for B cell differentiation, we set up a controlled primary culture system to differentiate human naive B cells into plasma cells (PCs). We identified T cell-produced IL-2 to be critically involved in ERK1/2-triggered PC differentiation. IL-2 drove activated B cell differentiation toward PC independently of its proliferation and survival functions. Indeed, IL-2 potentiated ERK activation and subsequent BACH2 and IRF8 downregulation, sustaining BLIMP1 expression, the master regulator for PC differentiation. Inhibition of the MAPK-ERK pathway, unlike STAT5 signaling, impaired IL-2-induced PC differentiation and rescued the expression profile of BACH2 and IRF8. These results identify IL-2 as a crucial early input in mature B cell fate commitment
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