299 research outputs found

    Changements climatiques, migrations et dĂ©fis de la gestion de l’environnement : Le cas d’un village au coeur de la tourmente au Burkina Faso

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    Les changements globaux ont des consĂ©quences dĂ©lĂ©tĂšres sur les conditions de vie, dans les pays sahĂ©liens d’Afrique. L’expĂ©rience du village de Koumbili (Burkina Faso), recueillie Ă  partir d’une Ă©valuation rurale participative (ERP) conduite en 2005, apporte une comprĂ©hension de la façon dont les changements climatiques et politiques actuels peuvent enclencher des comportements susceptibles de menacer l’intĂ©gritĂ© des Ă©cosystĂšmes dĂ©jĂ  fragilisĂ©s. Elle permet aussi une mise en perspective des mĂ©canismes qui opĂšrent en vue de renforcer les capacitĂ©s de gestion durable et d’organisation locales dans la rĂ©gion considĂ©rĂ©e.L’ERP a rĂ©vĂ©lĂ© que l’exploitation du terroir de Koumbili a connu une intensification marquĂ©e suite Ă  l’augmentation de l’effectif villageois rĂ©sultant en grande partie des migrations liĂ©es Ă  l’assĂšchement de rĂ©gions voisines et de la crise ivoirienne. La conservation du potentiel productif du terroir et l’accĂšs Ă  l’eau, sont donc devenus source de tensions et de conflits.Cet enjeu peut ĂȘtre relevĂ© en misant sur un rĂŽle moteur des associations villageoises et sur un maillage organisationnel qui permette d’intĂ©grer les diffĂ©rents types de compĂ©tences. La collaboration des universitĂ©s de Moncton et Ouagadougou a jouĂ© un rĂŽle central dans ce processus, et plus prĂ©cisĂ©ment dans le dĂ©veloppement local durable et l’innovation sociale communautaire. Cette Ă©tude de cas vise Ă  dĂ©montrer la pertinence de l’impact communautaire de la formation universitaire. S’appuyant sur l’interdisciplinaritĂ©, elle veut « rapprocher » l’universitĂ© des communautĂ©s rurales pour dĂ©velopper des apprentissages mutuels et des interactions renforçant les capacitĂ©s d’organisation et d’action des organisations villageoises.Global changes have detrimental consequences on the conditions of life in Sahelian countries. The experience of the village of Koumbili (Burkina Faso), documented through a participatory rural appraisal (PAR) conducted in 2005, brings a concrete understanding of how actual climatic and political changes can bring about human behaviours that jeopardize the integrity of fragile ecosystem. The case of Koumbili also allows an outlook on various mechanisms which aim at strengthening local sustainable management and local organization capacities in the region considered.PAR revealed that the exploitation of the village’s natural resources has intensified markedly, due to the rising of the population. A large part of the latter resulted from migrations related to the drying out of neighbouring regions and from displacements related to the Ivory Coast’s crisis. Conservation of land production potential and access to water, have thus become the cause of tensions and conflicts in the village populations. This issue can be addressed by enhancing village associations with educational institutions.Universities have an important role to play in this process, and more precisely in sustainable development and in community-based social innovation. This is the rational behind the institutional reinforcement partnership between UniversitĂ© de Moncton and UniversitĂ© de Ouagadougou. The present case study derives from this partnership. Its aim is to reinforce the pertinence and the impact of university teaching and research on local communities. It is based on interdisciplinarity and wishes to bring the university “closer” to rural communities in order to develop mutual learning and long-lasting interactions, in order to build the capacities of organisation and action at the local level

    Enhancement of Calcium/Vitamin D Supplement Efficacy by Administering Concomitantly Three Key Nutrients Essential to Bone Collagen Matrix for the Treatment of Osteopenia in Middle-Aged Women: A One-Year Follow-Up

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    Two vitamins and proline (CB6Pro), three nutrients essential for bone collagen, were used in combination to a 1000 mg calcium/250 IU vitamin D (Ca/D) daily supplement to treat osteopenia as a preventive measure against osteoporosis later in life. Middle-aged women not using estrogen were screened for osteopenia using the WHO criteria and divided into three groups (n = 20 each): 1) placebo healthy controls with normal bone mineral density (BMD); 2) control Ca/D-treated osteopenic patients; and 3) Ca/D + CB6Pro-treated osteopenic patients. The three groups were comparable at baseline except for BMD. After one-year treatment, cortical diaphyseal BMD remained constant in each group, but trabecular bone loss persisted (at 5 lumbar sites) in osteopenic group 2. No further bone loss was detected in osteopenic group 3. A loss of 2% was evidenced in the placebo group at one lumbar site. Markers of bone formation (which increase in coupling to resorption) decreased significantly in both osteopenic groups. Although biomarkers of resorption did not change, hormone (PTH and 1,25(OH)2D3)-induced osteoclastic activity was significantly reduced. No decline in BMD occurred at any bone site in osteopenic group 3, highlighting the importance of improving the quality of bone matrix concomitantly to mineral replacement

    Ataxia with oculomotor apraxia type 2: clinical, biological and genotype/phenotype correlation study of a cohort of 90 patients

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    Ataxia with oculomotor apraxia type 2 (AOA2) is an autosomal recessive disease due to mutations in the senataxin gene, causing progressive cerebellar ataxia with peripheral neuropathy, cerebellar atrophy, occasional oculomotor apraxia and elevated alpha-feto-protein (AFP) serum level. We compiled a series of 67 previously reported and 58 novel ataxic patients who underwent senataxin gene sequencing because of suspected AOA2. An AOA2 diagnosis was established for 90 patients, originating from 15 countries worldwide, and 25 new senataxin gene mutations were found. In patients with AOA2, median AFP serum level was 31.0 mu g/l at diagnosis, which was higher than the median AFP level of AOA2 negative patients: 13.8 mu g/l, P = 0.0004; itself higher than the normal level (3.4 mu g/l, range from 0.5 to 17.2 mu g/l) because elevated AFP was one of the possible selection criteria. Polyneuropathy was found in 97.5% of AOA2 patients, cerebellar atrophy in 96%, occasional oculomotor apraxia in 51%, pyramidal signs in 20.5%, head tremor in 14%, dystonia in 13.5%, strabismus in 12.3% and chorea in 9.5%. No patient was lacking both peripheral neuropathy and cerebellar atrophy. The age at onset and presence of occasional oculomotor apraxia were negatively correlated to the progression rate of the disease (P = 0.03 and P = 0.009, respectively), whereas strabismus was positively correlated to the progression rate (P = 0.03). An increased AFP level as well as cerebellar atrophy seem to be stable in the course of the disease and to occur mostly at or before the onset of the disease. One of the two patients with a normal AFP level at diagnosis had high AFP levels 4 years later, while the other had borderline levels. The probability of missing AOA2 diagnosis, in case of sequencing senataxin gene only in non-Friedreich ataxia non-ataxia-telangiectasia ataxic patients with AFP level >= 7 mu g/l, is 0.23% and the probability for a non-Friedreich ataxia non-ataxia-telangiectasia ataxic patient to be affected with AOA2 with AFP levels >= 7 mu g/l is 46%. Therefore, selection of patients with an AFP level above 7 mu g/l for senataxin gene sequencing is a good strategy for AOA2 diagnosis. Pyramidal signs and dystonia were more frequent and disease was less severe with missense mutations in the helicase domain of senataxin gene than with missense mutations out of helicase domain and deletion and nonsense mutations (P = 0.001, P = 0.008 and P = 0.01, respectively). The lack of pyramidal signs in most patients may be explained by masking due to severe motor neuropathy

    Electronic and physico-chemical properties of nanmetric boron delta-doped diamond structures

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    Heavily boron doped diamond epilayers with thicknesses ranging from 40 to less than 2 nm and buried between nominally undoped thicker layers have been grown in two different reactors. Two types of [100]-oriented single crystal diamond substrates were used after being characterized by X-ray white beam topography. The chemical composition and thickness of these so-called deltadoped structures have been studied by secondary ion mass spectrometry, transmission electron microscopy, and spectroscopic ellipsometry. Temperature-dependent Hall effect and four probe resistivity measurements have been performed on mesa-patterned Hall bars. The temperature dependence of the hole sheet carrier density and mobility has been investigated over a broad temperature range (6K<T<450 K). Depending on the sample, metallic or non-metallic behavior was observed. A hopping conduction mechanism with an anomalous hopping exponent was detected in the non-metallic samples. All metallic delta-doped layers exhibited the same mobility value, around 3.660.8 cm2/Vs, independently of the layer thickness and the substrate type. Comparison with previously published data and theoretical calculations showed that scattering by ionized impurities explained only partially this low common value. None of the delta-layers showed any sign of confinement-induced mobility enhancement, even for thicknesses lower than 2 nm.14 page

    Feasibility and Performance of the Staged Z-Pinch: A One-dimensional Study with FLASH and MACH2

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    Z-pinch platforms constitute a promising pathway to fusion energy research. Here, we present a one-dimensional numerical study of the staged Z-pinch (SZP) concept using the FLASH and MACH2 codes. We discuss the verification of the codes using two analytical benchmarks that include Z-pinch-relevant physics, building confidence on the codes' ability to model such experiments. Then, FLASH is used to simulate two different SZP configurations: a xenon gas-puff liner (SZP1*) and a silver solid liner (SZP2). The SZP2 results are compared against previously published MACH2 results, and a new code-to-code comparison on SZP1* is presented. Using an ideal equation of state and analytical transport coefficients, FLASH yields a fuel convergence ratio (CR) of approximately 39 and a mass-averaged fuel ion temperature slightly below 1 keV for the SZP2 scheme, significantly lower than the full-physics MACH2 prediction. For the new SZP1* configuration, full-physics FLASH simulations furnish large and inherently unstable CRs (> 300), but achieve fuel ion temperatures of many keV. While MACH2 also predicts high temperatures, the fuel stagnates at a smaller CR. The integrated code-to-code comparison reveals how magnetic insulation, heat conduction, and radiation transport affect platform performance and the feasibility of the SZP concept

    Nouméa: a new multi-mission calibration and validation site for past and future altimetry missions?

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    Today, monitoring the evolution of sea level in coastal areas is of importance, since almost 11 % of the world's population lives in low-lying areas. Reducing uncertainties in sea level estimates requires a better understanding of both altimetry measurements and local sea level dynamics. In New Caledonia, the NoumĂ©a lagoon is an example of this challenge, as altimetry, coastal tide gauge, and vertical land motions from global navigation satellite systems (GNSSs) do not provide consistent information. The GEOCEAN-NC 2019 field campaign addresses this issue with deployments of in situ instruments in the lagoon (GNSS buoy, pressure gauge, etc.), with a particular focus on the crossover of one Jason-series track and two Sentinel-3A missions tracks. In this study, we propose a method to virtually transfer the NoumĂ©a tide gauge at the altimetry crossover point, using in situ data from the field campaign. Following the philosophy of calibration and validation (Cal/Val) studies, we derive absolute altimeter bias time series over the entire Jason and Sentinel-3A periods. Overall, our estimated altimeter mean biases are slightly larger by 1–2 cm compared to Corsica and Bass Strait results, with inter-mission biases in line with those of Bass Strait site. Uncertainties still remain regarding the determination of our vertical datum, only constrained by the three days of the GNSS buoy deployment. With our method, we are able to re-analyse about 20 years of altimetry observations and derive a linear trend of −0.2 ± 0.1 mm yr−1 over the bias time series. Compared to previous studies, we do not find any significant uplift in the area, which is more consistent with the observations of inland permanent GNSS stations. These results support the idea of developing Cal/Val activities in the lagoon, which is already the subject of several experiments for the scientific calibration phase of the SWOT wide-swath altimetry mission.</p

    Effectiveness of anti-psychotics and related drugs in the Huntington French-speaking group cohort.

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    PURPOSE: Huntington's disease is a rare condition. Patients are commonly treated with antipsychotics and tetrabenazine. The evidence of their effect on disease progression is limited and no comparative study between these drugs has been conducted. We therefore compared the effectiveness of antipsychotics on disease progression. METHODS: 956 patients from the Huntington French Speaking Group were followed for up to 8 years between 2002 and 2010. The effectiveness of treatments was assessed using Unified Huntington's Disease Rating Scale (UHDRS) scores and then compared using a mixed model adjusted on a multiple propensity score. RESULTS: 63% of patients were treated with antipsychotics during the survey period. The most commonly prescribed medications were dibenzodiazepines (38%), risperidone (13%), tetrabenazine (12%) and benzamides (12%). There was no difference between treatments on the motor and behavioural declines observed, after taking the patient profiles at the start of the drug prescription into account. In contrast, the functional decline was lower in the dibenzodiazepine group than the other antipsychotic groups (Total Functional Capacity: 0.41 ± 0.17 units per year vs. risperidone and 0.54 ± 0.19 vs. tetrabenazine, both p&lt;0.05). Benzamides were less effective than other antipsychotics on cognitive evolution (Stroop interference, Stroop color and Literal fluency: p&lt;0.05). CONCLUSIONS: Antipsychotics are widely used to treat patients with Huntington's disease. Although differences in motor or behavioural profiles between patients according to the antipsychotics used were small, there were differences in drug effectiveness on the evolution of functional and cognitive scores

    Gerstmann-Straussler-Scheinker disease in an Alsatian family: clinical and genetic studies

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    The clinical progression of Gerstmann-Straussler-Scheinker disease in a family of Alsatian origin is reported. The age of onset and the duration of evolution were variable. The clinical picture became more complex over the generations: in the first generations, isolated dementia and in later generations a triad of pyramidal, pseudobulbar syndromes and dementia associated with spinal cord and cerebellar features. Prion gene analysis showed that four surviving patients carry double missense changes at codons 117 and 129, identical to those found in one case at necropsy and 10 other healthy members of the family. The missense changes were not found in 100 controls. No member of the family had modification of condons 102, 178, or 200. The lod score suggests linkage between the missense change at codon 117 and Gerstmann- Straussler-Scheinker disease in this family

    Low penetrance in facioscapulohumeral muscular dystrophy type 1 with large pathological D4Z4 alleles: a cross-sectional multicenter study.

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    BackgroundFacioscapulohumeral muscular dystrophy type 1(FSHD1) is an autosomal dominant disorder associated with the contraction of D4Z4 less than 11 repeat units (RUs) on chromosome 4q35. Penetrance in the range of the largest alleles is poorly known. Our objective was to study the penetrance of FSHD1 in patients carrying alleles ranging between 6 to10 RUs and to evaluate the influence of sex, age, and several environmental factors on clinical expression of the disease. Methods A cross-sectional multicenter study was conducted in six French and one Swiss neuromuscular centers. 65 FSHD1 affected patients carrying a 4qA allele of 6Âż10 RUs were identified as index cases (IC) and their 119 at-risk relatives were included. The age of onset was recorded for IC only. Medical history, neurological examination and manual muscle testing were performed for each subject. Genetic testing determined the allele size (number of RUs) and the 4qA/4qB allelic variant. The clinical status of relatives was established blindly to their genetic testing results. The main outcome was the penetrance defined as the ratio between the number of clinically affected carriers and the total number of carriers. Results Among the relatives, 59 carried the D4Z4 contraction. At the clinical level, 34 relatives carriers were clinically affected and 25 unaffected. Therefore, the calculated penetrance was 57% in the range of 6Âż10 RUs. Penetrance was estimated at 62% in the range of 6Âż8 RUs, and at 47% in the range of 9Âż10 RUs. Moreover, penetrance was lower in women than men. There was no effect of drugs, anesthesia, surgery or traumatisms on the penetrance. Conclusions Penetrance of FSHD1 is low for largest alleles in the range of 9Âż10 RUs, and lower in women than men. This is of crucial importance for genetic counseling and clinical management of patients and families
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