90 research outputs found

    Using remotely sensed solar radiation data for reference evapotranspiration estimation at a daily time step

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    International audienceSolar radiation is an important climatic variable for assessing reference evapotranspiration (E0), but it is seldom available in weather station records. Meteosat satellite images processed with the Heliosat-2 method provide the HelioClim-1 database, which displays spatialized solar radiation data at a daily time step for Europe and Africa. The aim of the present work was to investigate the interest of satellite-sensed solar radiation for E0 calculation, where air temperature is the sole local weather data available. There were two study areas in Southern France. One (Southwest, SW) is characterized by Oceanic climate and the other (Southeast, SE) by Mediterranean climate. A data set of daily values for 19 weather stations spanning five years (2000–2004) was used. First, a sensitivity analysis of the Penman–Monteith formula to climate input variables was performed, using the Sobol' method. It shows that E0 is mainly governed by solar radiation during summer, and by wind speed during winter. Uncertainties of HelioClim-1 solar radiation data and their repercussions on E0 formulae were evaluated, using the FAO-56 Penman–Monteith formulae (PM) and radiation-based methods (Turc, TU; Priestley–Taylor, PT and Hargreaves-Radiation, HR). It was shown that HelioClim-1 data slightly underestimate solar radiation and provide relative RMSE (root mean square error) of 20% of the mean annual value for SW and 14% for SE. The propagation of HelioClim-1 data uncertainties is small in PM but considerable in radiation methods. Four estimation methods were then compared to PM data: the 1985 Hargreaves formula (HT) based on air temperature only; TU, PT and HR, based on air temperature and satellite-sensed solar radiation. Radiation methods were more precise and more accurate than HT, with RMSE ranging from 0.52 mm to 0.86 mm against 0.67–0.96 mm. These results suggest that using satellite-sensed solar radiation may improve E0 estimates for areas where air temperature is the only available record at ground level

    Estimating spatial and temporal variations in solar radiation within Bordeaux winegrowing region using remotely sensed data

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    International audienceAims: This paper presents a study solar radiation spatial and temporal variations in Bordeaux winegrowing area, for a 20 year period (1986-2005). Methods and results: Solar radiation data was retrieved from the HelioClim-1 database, elaborated from Meteosat satellite images, using the Heliosat-2 algorithm. Daily data was interpolated using ordinary kriging to produce horizontal solar radiation maps at a 500 m resolution. Using a digital elevation model, high resolution daily solar radiation maps with terrain integration were then produced for the period 2001-2005, at a 50 m resolution. The long term (20 years) analysis of solar radiation at low spatial resolution (500 m) showed a west to east decreasing gradient within Bordeaux vineyards. Mean August-to-September daily irradiation values, on horizontal surface, were used to classify Bordeaux winegrowing areas in three zones: low, medium, and high solar radiation areas. This initial zoning was upscaled at 50 m resolution, applying a local correction ratio, based on 2001-2005 solar radiation on inclined surface analysis. Grapevine development and maturation potential of the different zones of appellation of origin of Bordeaux winegrowing area are discussed in relation with this zoning. 2 Conclusions: Solar radiation variability within Bordeaux winegrowing area is mainly governed by terrain slopes and orientations, which induce considerable variations within the eastern part of Bordeaux vineyards. Significance and impact of the study: Solar radiation has a major impact on vineyard water balance, grapevine development and berry ripening. However, irradiation data is seldom available in weather stations records. This paper underline the interest of high resolution cartography of solar radiation, using satellite sensing and terrain effect integration, for agroclimatic studies in viticulture

    Reduced Self-Perception of Fatigue after Intake of Panax ginseng Root Extract (G115®) Formulated with Vitamins and Minerals An Open-Label Study

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    Background: Unexplained fatigue is a common complaint. When underlying disease causes have been eliminated, lifestyle measures and supplementation can be indicated. Elaborating on clinical findings that G115®, a dry extract from the root of Panax ginseng, combined with vitamins and minerals could alleviate fatigue, this open label study aimed at assessing its effect on perceived fatigue and energy. Methods: Healthy adults self-reporting fatigue (n = 103) completed the Multidimensional Fatigue Inventory questionnaire. They rated their perceptions of mental and physical fatigue, energy, performance, and stress at baseline and 15, 30, 60 and 90 days after a daily intake of 40 mg G115® formulated with vitamins and minerals. Results: Compared with baseline values, mean self-perception of general fatigue was reduced by −7.55 units [95% CI: −8.44; −6.66] (−41.8%, p < 0.0001) at 90 days. All assessed perception ratings (mental and physical fatigue, reduced activity and motivation, performance, and stress) were significantly and steadily improved from two weeks after supplementation up to study's end. Overall satisfaction with the ability of the product to reduce fatigue reached 85% at Day 90. Conclusion: Daily intake with G115® extract formulated with vitamins and minerals suggests an improvement of self-perception of fatigue and energy in a fatigued adult population

    Uniparental (mtDNA, Y-chromosome) Polymorphisms in French Guiana and Two Related Populations - Implications for the Region's Colonization

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    International audienceBlood samples collected in four Amerindian French Guiana populations (Palikur, Emerillon, Wayampi and Kali'na) in the early 1980s were screened for selected mtDNA and Y-chromosome length polymorphisms, and sequenced for the mtDNA hypervariable segment I (HVS-I). In addition, two other Amerindian populations (Apalaí and Matsiguenga) were examined for the same markers to establish the genetic relationships in the area. Strong dissimilarities were observed in the distribution of the founding Amerindian haplogroups, and significant p-values were obtained from F(ST) genetic distances. Interpopulation similarities occurred mainly due to geography. The Palikur did not show obvious genetic similarity to the Matsiguenga, who speak the same language and live in a region from where they could have migrated to French Guiana. The African-origin admixture observed in the Kali'na probably derives from historical contacts they had with the Bushinengue (Noir Marron), a group of escaped slaves who now lead independent lives in a nearby region. This analysis has identified significant clues about the Amerindian peopling of the North-East Amazonian region

    MRD codes with maximum idealizers

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    Left and right idealizers are important invariants of linear rank-distance codes. In the case of maximum rank-distance (MRD for short) codes in Fqn×n\mathbb{F}_q^{n\times n} the idealizers have been proved to be isomorphic to finite fields of size at most qnq^n. Up to now, the only known MRD codes with maximum left and right idealizers are generalized Gabidulin codes, which were first constructed in 1978 by Delsarte and later generalized by Kshevetskiy and Gabidulin in 2005. In this paper we classify MRD codes in Fqn×n\mathbb{F}_q^{n\times n} for n≤9n\leq 9 with maximum left and right idealizers and connect them to Moore-type matrices. Apart from generalized Gabidulin codes, it turns out that there is a further family of rank-distance codes providing MRD ones with maximum idealizers for n=7n=7, qq odd and for n=8n=8, q≡1(mod3)q\equiv 1 \pmod 3. These codes are not equivalent to any previously known MRD code. Moreover, we show that this family of rank-distance codes does not provide any further examples for n≥9n\geq 9.Comment: Reviewers' comments implemented, we changed the titl

    Simple scoring system to predict in-hospital mortality after surgery for infective endocarditis

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    BACKGROUND: Aspecific scoring systems are used to predict the risk of death postsurgery in patients with infective endocarditis (IE). The purpose of the present study was both to analyze the risk factors for in-hospital death, which complicates surgery for IE, and to create a mortality risk score based on the results of this analysis. METHODS AND RESULTS: Outcomes of 361 consecutive patients (mean age, 59.1\ub115.4 years) who had undergone surgery for IE in 8 European centers of cardiac surgery were recorded prospectively, and a risk factor analysis (multivariable logistic regression) for in-hospital death was performed. The discriminatory power of a new predictive scoring system was assessed with the receiver operating characteristic curve analysis. Score validation procedures were carried out. Fifty-six (15.5%) patients died postsurgery. BMI >27 kg/m2 (odds ratio [OR], 1.79; P=0.049), estimated glomerular filtration rate 55 mm Hg (OR, 1.78; P=0.032), and critical state (OR, 2.37; P=0.017) were independent predictors of in-hospital death. A scoring system was devised to predict in-hospital death postsurgery for IE (area under the receiver operating characteristic curve, 0.780; 95% CI, 0.734-0.822). The score performed better than 5 of 6 scoring systems for in-hospital death after cardiac surgery that were considered. CONCLUSIONS: A simple scoring system based on risk factors for in-hospital death was specifically created to predict mortality risk postsurgery in patients with IE

    Cartographie agroclimatique à meso-échelle (méthodologie et application à la variabilité spatiale du climat en Gironde viticole)

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    Une connaissance approfondie de la variabilité spatiale du climat est essentielle en agronomie et agroforesterie. En viticulture, le climat conditionne largement la cinétique de développement de la vigne ainsi que la maturation du raisin. L objectif de ce travail était de caractériser la variabilité spatiale du climat à méso-échelle en utilisant différentes techniques de spatialisation au pas de temps quotidien de variables climatiques et d indices agroclimatiques, afin d évaluer ses conséquences sur le développement de la vigne et sur la maturation du raisin. La région considérée est la Gironde viticole (aire de production des vins de Bordeaux). Six variables ont été étudiées: les températures minimales et maximales, le rayonnement global, l évapotranspiration potentielle, les précipitations et le bilan hydrique. Pour chaque variable, la méthode de spatialisation fournissant les résultats les plus pertinents à des coûts informatique et temporel raisonnables a été sélectionnée. La propagation des erreurs produites par la spatialisation des variables climatiques au pas de temps quotidien dans les modèles agroclimatiques a ensuite été évaluée. Cette propagation est non négligeable dans le calcul des sommes de températures et des bilans hydriques. La cartographie des variables climatiques a permis de caractériser la variabilité spatiale du climat en Gironde viticole et de bien quantifier des différences entre aires d appellation qui n étaient connues que de manière très empirique. Les résultats de cette étude permettront de mieux adapter les techniques viticoles et le choix du matériel végétal aux possibilités offertes par le milieu.Climate spatial variability knowledge is essential in agronomy and forestry, in order to characterize production potential or to assess pest development risks. In viticulture, climate mainly governs grapevine development rate and berry ripening. The aim of the present work is to characterise climate spatial variability at mesoscale level, using several spatialization techniques at daily time step, applied to climate variables and agroclimatic indices, in order to evaluate its consequences on grapevine development and grape ripening. This study was led in the Bordeaux winegrowing region. Six variables were studied: minimum and maximum temperatures, solar radiation, reference evapotranspiration, rainfall and soil water balance. For each variable, the method providing the best results (i.e. the lowest errors) with reasonable computational and time costs was selected. The propagation of spatialization errors within agroclimatic models was assessed. The error propagation is considerable within degree-days and soil water balance models. Maps of climate variables and agroclimatic indices were used to analyse the spatial characteristics of climate within the Bordeaux winegrowing area and to quantify differences that were known only from indirect and empirical observations. This study provides useful information to enhance the choice of viticultural techniques and plant material in relation to the local environment.BORDEAUX1-BU Sciences-Talence (335222101) / SudocSudocFranceF

    Progressive and nonprogressive hereditary chronic nephritis

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    Progressive and nonprogressive hereditary chronic nephritis. Two groups of patients had hereditary chronic nephritis (HCN). The first group included six patients: microscopic hematuria was found in all six; the nephrotic syndrome developed in 3 patients and renal failure in 2. Neural hearing defect was detected in 2 patients. Precise genetic data showed that the deleterious gene appeared to have been inherited from women. Electron microscopic examination of renal specimens revealed a characteristic involvement of the glomerular basement membrane (GBM), whose lamina densa was distorted. In contrast, in six of the seven patients of the second group, the nephrotic syndrome and renal failure were not noted during the follow-up period. Renal failure was observed in only one patient, a 62-year-old man. The GBM was normal on examination by electron microscopy. The prognostic value of these data is significant. In addition to nerve deafness, abundant proteinuria and GBM ultrastructural lesion indicate progressive nephritis. Moreover, in affected men the prognosis is worse when the condition is inherited through the mother rather than through the father.Néphropathies chroniques héréditaires évolutives et non évolutives. Deux groupes de malades atteints de néphropathie chronique héréditaire ont été étudiés. Le premier groupe comprend 6 malades: l'hématurie microscopique était constante; un syndrome néphrotique est apparu chez 3 malades, une insuffisance rénale chez 2. Une hypoacousie de perception a été détectée chez 2 malades. Chez les malades où des données génétiques précises ont pu être utilisées, le gène délétère a été transmis par les sujets de sexe féminin. L'examen en microscopie électronique du fragment biopsique rénal a montré une lésion caractéristique de la membrane basale glomérulaire (MBG) dont la lamina densa est désorganisée. Au contraire, chez 6 malades du deuxième groupe, un syndrome néphrotique et une insuffisance rénale n'ont jamais été notés, tout au moins dans les limites du recul actuel. Seul un malade âgé de 62 ans a une insuffisance rénale. La MBG était normale en microscopie électronique. La signification pronostique de ces données a été analysée. En plus de la surdité de perception, la présence d'une protéinurie abondante et de la lésion ultrastructurale caractéristique de la MBG fait craindre une néphropathie évolutive. En outre chez les sujets atteints de sexe masculin, la transmission par la mère a une valeur pronostique péjorative par rapport à la transmission par le père
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