Nouvelle carte des isohyètes annuelles et des maxima pluviométriques sur le massif du Piton de la Fournaise (Ile de la Réunion)

L'implantation de douze pluviographes, de 220 à 2490 mètres d'altitude, dans des sites difficilement accessibles des versants sud et est du massif du Piton de la Fournaise à la Réunion, apporte de nouveaux éléments pour le tracé des isohyètes annuelles. Un pluviographe situé à 1600 mètres d'altitude, à l'amont d'un alignement orienté sud-nord dans la zone du Baril sur la planèze sud-est du Volcan, a enregistré une précipitation annuelle supérieure à 18 000 mm en 1993. Dans cette zone, les cartes d'isohyètes moyennes inter-annuelles admises jusqu'alors présentaient des lames d'eau de lordre de 5000 à 6000 mm.an-¹. Les enregistrements obtenus en 1994 puis en 1995 sur le même pluviographe et sur des stations situées à l'est du massif à 1400 et à 1940 mètres d'altitude confirment qu'une très forte pluviométrie affecte cette zone.Une couche d'inversion thermique est fréquemment observée par ballon-sondage entre 2000 et 2500 mètres d'altitude, principalement en hiver austral. Cette inversion est l'une des causes principales de la présence d'une zone de maximum pluviométrique située entre 1400 et 1940 mètres d'altitude sur les planèzes du Volcan. Selon la position de l'inversion, la Réunion est soit dans la situation des îles très hautes, avec des sommets émergeant des nuages, soit dans la situation des îles hautes, pour lesquelles les précipitations sont fortes près des sommets. Les fortes pentes des versants du massif et la présence de grands encaissements contribuent également à expliquer l'emplacement de la zone de maximum pluviométrique et les lames d'eau importantes qui y sont enregistrées.Une nouvelle carte des isohyètes annuelles est proposée pour prendre en compte les nouvelles données. Une zone de maximum pluviométrique définie par l'isohyète 12 000 mm de moyenne annuelle est localisée entre 1300 et 1800 mètres d'altitude, localement jusqu'à 2000 m, sur le versant oriental du massif exposé aux vents dominants. De part et d'autre de cette zone la pluviométrie diminue: les lames d'eau moyennes annuelles décroissent jusqu'à 4000 mm au niveau de la mer, elles représentent 7000 mm au sommet à 2632 mètres d'altitude. L'atténuation rapide des précipitations sur les versants nord-ouest et sud-ouest est liée au changement de l'orientation des versants par rapport aux flux générateurs de précipitations mais sans doute également à l'influence de grandes discontinuités topographiques orientées perpendiculairement aux vents dominants.Reunion Island, located in the south-west Indian Ocean (21° S / 55° E), is composed of 2 volcanoes linked with a hot spot activity: the Piton des Neiges massif (3069 m) in the north-west and the Piton de la Fournaise massif (2632 m) in the south-east (Fig. 1). Climate is intertropical and characterized by two distinct periods: the hot rainfall season, from December to April, and the rather temperate dry season from May to November. South-east to east trade winds prevail during austral winter. However, polar atmospheric disturbances occasionally affect the island. Ascending wet air masses over a rugged topography with high summits and strong slopes release intense orographic rainfalls on the windward eastern slopes of the island. This phenomenon has been reported for other islands where rainfall was shown to be correlated with altitude (Rossignol, 1990; Oki et al., 1991). For trade winds and polar disturbances rainfalls, the maximum zone lies below the thermal inversion layer (Table 1). This layer, present 80% of the time, is found between an altitude of 2000 to 2500 metres in one third of the cases (Fig. 6 and Fig. 7). Cyclonic rainfalls, frequent during the austral summer, increase with altitude. Cyclones generate heavy rains on the eastern slopes of the Piton de la Fournaise massif while they approach the island from the north-east to east sectors (Malick and Mercusot, 1976; Fig. 12).Available isohyet maps (Fig. 3) show a maximum rainfall zone at 860 metres, centred on les Hauts de Sainte-Rose rain gauge, on the north-eastern slope of the Piton de la Fournaise massif. There, the average rainfall is higher than 10 000 mm.year-1, and decreases in the west and south directions: at the same altitude in Baril, on the south side of the massif, annual rainfall totals were estimated between 5000 and 6000 mm (Anonyme, 1975; Bargeas et al., 1984; Robert, 1986).In 1993, twelve tipping bucket rain gauges connected to data loggers or remote transmitters were installed between 220 and 2490 metres to precisely determine isohyets and define the presence of an altitude-dependent maximum rainfall zone (Fig. 2). On the south side of the massif, four rain gauges (altitude 650, 900, 1200 and 1600 m) form the north to south Baril transect along the main slope of the mountain.During the first sampling year at Baril 1600, where water totals are maximum, the annual rainfall was higher than 18 000 millimetres (Table 2; Fig. 4). This constitutes the highest amount ever recorded on Reunion Island. A previous record was set at les Hauts de Sainte-Rose rain gauge (15 381 mm, from 1 August 1979 to 31 July 1980). Return periods over the 27 February 1993 - 26 February 1994 time interval calculated from Météo France reference rain gauge data show that the studied year was not exceptionally wet (Table 3 and Fig. 5). Since 1993, other measurements from the Baril transect, as well as from Bois Blanc and Enclos transects on the east side of the massif, suggest an under-evaluation of isohyet estimations, principally on the east and the south sides of la Fournaise volcano (Fig. 8, Fig. 9 , Fig. 10 and Fig. 11; Table 4).A comparison between the climatologic and topographic environment of Reunion Island and other similar islands such as Hawaii, Maui, Kauai or Oahu in the Hawaiian archipelago (Bean et al., 1994; Ekern et al., 1971; Giambelluca et al., 1986; Giambelluca and Nullet, 1992; Giambelluca and Sanderson, 1993; Juvik and Nullet, 1994; Nullet and Juvik, 1994; Nullet et al., 1995; Peterson, 1972; Schroeder, 1993), Tenerife in the Canary islands (Custodio et al., 1991), Fogo in the Cape Verde islands (Juvik et al., 1995), or Guadeloupe in the Caribbean Sea (Robin and Rossignol, 1988) is presented (Table 5).In Hawaii a distinction has been made between high and very high islands. High islands (such as Oahu, Kauai, east Maui, Guadeloupe or Gran Canaria) have an elevation lower or equal to the thermal inversion layer mean altitude. Water totals are very high and located near the summits. In very high islands (such as Hawaii, west Maui, Tenerife or Fogo), with summits often higher than the thermal inversion layer, rainfalls are more moderate and located lower on windward slopes.La Fournaise volcano experiences these two situations alternately, depending on the presence, altitude and strength of the thermal inversion layer. When it is strong and low, during austral winter, rainfalls are restricted to low elevation zones. The frequent lack of thermal inversion during the hot season, or its high position when present, and the occurrence of tropical depressions cause heavy rains near the summits. These elements and the presence of great embankments and steep slopes, which are increasing relief effects, contribute to give to Reunion Island an original climatic and hydrologic environment. The maximum rainfall zone has a large extension in altitude, along the upper part of steep windward slopes. Recorded water totals and rainfall gradients count among the highest recorded values.Subsequently, atmospheric and topographic elements defining spatial rainfall variations are discussed, and a new isohyet map is proposed (Fig. 13). A maximum rainfall zone over 12 000 mm.year-¹ is defined on the whole eastern side of the massif between 1300 and 1800 metres, and locally up to 2000 metres. Above and below this zone, rainfall decreases to 7000 mm.year-¹ at the summit of the Volcano, and to 4000 mm.year-¹ at sea level respectively. Isohyets are nearly parallel to contour lines on all sides of the Volcano except along the north-western and south-western slopes. On the north-western part of the massif, rainfall decreases to 4000 - 5000 mm.year-¹ since slope exposure to prevailing trade winds diminishes. South-western slopes rapidly become leeward, and rainfall amounts to less than 2000 mm.year-¹

Supported internet-delivered cognitive behavioral therapy programs for depression, anxiety, and stress in university students: open, non-randomised trial of acceptability, effectiveness, and satisfaction

BACKGROUND: Many university campuses have limited mental health services that cannot cope with the high demand. One alternative is to use internet-delivered cognitive behavioral therapy (iCBT) as a way of tackling barriers such as lack of availability and scheduling issues. OBJECTIVE: This study aimed to assess feasibility, acceptability, effectiveness, and satisfaction of a supported iCBT intervention offering 3 programs on depression, anxiety, and stress to university students. The design was an open or nonrandomized feasibility trial. METHODS: Participants were recruited from 3 counseling centers at a large midwestern University in the United States. Those agreeing to take part chose 1 of 3 iCBT programs-Space from Depression, Space from Anxiety, or Space from Stress -all comprised 8 modules of media-rich interactive content. Participants were supported throughout the trial by a trained professional. The Patient Health Questionnaire 9 (PHQ-9), Generalized Anxiety Disorder 7 (GAD-7) questionnaire, and stress subscale of the Depression Anxiety and Stress Scale (DASS-21) were completed at baseline, 8 weeks, and 3-month follow-up. A Satisfaction With Treatment (SAT) questionnaire was completed at 8 weeks, and qualitative interviews were completed by a subsample of participants at 3 months. RESULTS: A total of 102 participants were recruited, with 52 choosing Space from Anxiety, 31 choosing Space from Depression, and 19 choosing Space from Stress. Mixed-effects models showed a significant decrease in symptoms of depression (F₄=6.36, P<.001), anxiety (F₄=7.97, P<.001), and stress (F₄=8.50, P<.001) over time across all 3 programs. The largest decreases in PHQ-9 scores at 8 weeks were among participants who chose the Space from Depression program (d=0.84); at 3 months, the largest decreases in PHQ-9 scores were among those who chose the Space from Stress program (d=0.74). The largest decreases in GAD-7 scores were among those who chose the Space from Anxiety program (d=0.74 at 8 weeks and d=0.94 at 3 months). The largest decrease in DASS-21 stress subscale scores was among those who chose the Space from Stress program (d=0.49 at 8 weeks and d=1.16 at 3 months). The mean time spent using the platform per session was 27.4 min (SD 33.8), and participants completed 53% (SD 37.6) of the total program content on average. Most (37/53, 69%) participants found the programs helpful or very helpful and liked the convenience and flexibility of the intervention. Qualitative interviews (n=14) indicated the intervention met students' expectations, and they saw it as a valuable complement to face-to-face treatment. CONCLUSIONS: The iCBT programs tested in our study appear to be feasible, acceptable, and effective in a university environment. Participants described the benefits of having a flexible, supported Web-based intervention available on campus. Larger trials should be conducted to further test the effectiveness of supported Web-based interventions that give students a choice of program depending on their symptom profile.Published versio

Improvement of the guiding performances of near infrared organic/inorganic channel waveguides

New sol-gel derived organic/inorganic hybrid single mode waveguides devices have been developed for telecommunication applications in the two near infrared windows at 1310 and 1550 nm. The overall procedure of fabrication of these devices is described and the refractive indices of the guiding, the buffer and the protective layers are adjusted by a precise control of the materials' composition. Due to the improvement of the composition of the guiding layer, the attenuation losses are significantly decreased to 0.8 dB/cm and 2dB/cm at respectively 1310 and 1550 nm

Dairy product consumption in french children in 2010

Dairy food consumption is important for children as it contributes to the intake of key nutrients, especially calcium. The aim of the present paper is to provide an overview of dairy products consumption for French children, according to age, sex and type of dairy products. Adequacy of dairy and calcium intakes in line with French national guidelines "3 portions of dairy products per day" were also evaluated. Data were extracted and analyzed from the CCAF-Comportementet Consommations Alimentairesen France-study. Seven-day questionnaires were administered to free-living individuals from autumn 2009 to summer 2010. Subjects were children (n=1171) aged 3-17 years. Dairy products contributed substantially to the intake of calcium, phosphorus, potassium, zinc, vitamin B2 and vitamin B12. A general decrease in DP consumption has been observed since 2003. This is most notably due to a lower milk intake which is not compensated by increased cheese or fresh dairy products. Most of children (67%), and up to 73% of adolescents (15 - 17 y), did not reach the recommended "3 servings of dairy products per day". Twenty percent of children from the age of 6 and nearly 2/3 of female adolescents did not reach their estimated average requirement for calcium. The overview of French dairy food consumption during childhood, of particular Public Health concern, emphasizes the need to encourage dairy consumption and particularly milk consumption at breakfast in order to maintain a nutrient adequacy in children and adolescents

Serum selenium concentrations and diabetes in U.S. adults : National Health and Nutrition Examination Survey (NHANES) 2003–2004

Background: Increasing evidence suggests that high selenium levels are associated with diabetes and other cardiometabolic risk factors. Objectives: We evaluated the association of serum selenium concentrations with fasting plasma glucose, glycosylated hemoglobin levels, and diabetes in the most recently available representative sample of the U.S. population. Methods: We used a cross-sectional analysis of 917 adults ≥ 40 years of age who had a fasting morning blood sample in the National Health and Nutrition Examination Survey 2003–2004. We evaluated the association of serum selenium, measured by inductively coupled plasma-dynamic reaction cell-mass spectrometry, and diabetes, defined as a self-report of current use of hypoglycemic agents or insulin or as fasting plasma glucose ≥ 126 mg/dL. Results: Mean serum selenium was 137.1 μg/L. The multivariable adjusted odds ratio [95% confidence interval (CI)] for diabetes comparing the highest quartile of serum selenium (≥ 147 μg/L) with the lowest (< 124 μg/L) was 7.64 (3.34–17.46). The corresponding average differences (95% CI) in fasting plasma glucose and glycosylated hemoglobin were 9.5 mg/dL (3.4–15.6 mg/dL) and 0.30% (0.14–0.46%), respectively. In spline regression models, the prevalence of diabetes as well as glucose and glycosylated hemoglobin levels increased with increasing selenium concentrations up to 160 μg/L. Conclusions: In U.S. adults, high serum selenium concentrations were associated with higher prevalence of diabetes and higher fasting plasma glucose and glycosylated hemoglobin levels. Given high selenium intake in the U.S. population, further research is needed to determine the role of excess selenium levels in the development or the progression of diabetes

Cartographie AMT du biseau salé sur le flanc sud du Piton de la Fournaise (Ile de la Réunion)

Dans le secteur du Baril, situé sur la planèze sud du volcan de la Fournaise, l'interprétation unidimensionnelle (1-D) de 34 sondages AMT montre une séquence à trois terrains, avec disparition du deuxième dans la zone côtière. Cette séquence comprend un horizon supérieur résistant (> 1000 Ohm.m), un horizon intermédiaire plus conducteur (100 à 600 Ohm.m), et un substratum très conducteur (< 10 Ohm.m). Les résistivités obtenues permettent d'assimiler ce substratum au biseau salé. Les variations importantes dans la topographie du toit du biseau salé apportent des données nouvelles concernant les phénomènes de pénétration saline dans les aquifères volcaniques et, indirectement, une meilleure connaissance de la géométrie et du fonctionnement de l'aquifère sus-jacent. (Résumé d'auteur

A simple method to assess the oxidative susceptibility of low density lipoproteins

BACKGROUND: Oxidative modification of low density lipoproteins (LDL) is recognized as one of the major processes involved in atherogenesis. The in vitro standardized measurement of LDL oxidative susceptibility could thus be of clinical significance. The aim of the present study was to establish a method which would allow the evaluation of oxidative susceptibility of LDL in the general clinical laboratory. RESULTS: LDL was isolated from human plasma by selective precipitation with amphipathic polymers. The ability of LDL to form peroxides was assessed by measuring thiobarbituric acid reactive substances (TBARS) after incubation with Cu(2+) and H(2)O(2). Reaction kinetics showed a three-phase pattern (latency, propagation and decomposition phases) which allowed us to select 150 min as the time point to stop the incubation by cooling and EDTA addition. The mixture Cu(2+)/H(2)O(2) yielded more lipoperoxides than each one on its own at the same time end-point. Induced peroxidation was measured in normal subjects and in type 2 diabetic patients. In the control group, results were 21.7 ± 1.5 nmol MDA/mg LDL protein, while in the diabetic group results were significantly increased (39.0 ± 3.0 nmol MDA/mg LDL protein; p < 0.001). CONCLUSION: a simple and useful method is presented for the routine determination of LDL susceptibility to peroxidation in a clinical laboratory

Effects of zinc supplementation on cognitive function in healthy middle-aged and older adults: the ZENITH study

A randomised double-blind placebo-controlled design was employed to investigate the effects of Zn supplementation on cognitive function in 387 healthy adults aged 55–87 years. Several measures of visual memory, working memory, attention and reaction time were obtained using the Cambridge Automated Neuropsychological Test Battery at baseline and then after 3 and 6 months of 0 (placebo), 15 or 30 mg Zn/d. Younger adults (70 years), and performance improved with practice on some measures. For two out of eight dependent variables, there were significant interactions indicating a beneficial effect (at 3 months only) of both 15 and 30 mg/d on one measure of spatial working memory and a detrimental effect of 15 mg/d on one measure of attention. Further work is required to establish whether these findings generalise to older adults in poorer mental and physical health and with less adequate Zn intake and status than the present sample

Dedicated and industrial robotic arms used as force feedback telerobots at the AREVA-La Hague recycling plant

ISBN: 978-1-4244-6635-1/10International audienceCEA LIST and AREVA have been developing remote operations devices, also called telerobotics for 15 years. These tools were designed for interventions in the AREVA nuclear spent fuel facilities hot cells. From these 15 years of joint research and development, several technological bricks have been industrialized and used at the AREVA La Hague facilities. This article presents some of these bricks and their industrial developments. The “TAO2000” CEA LIST telerobotics generic software controller will be first discussed. This controller has been used to teleoperate dedicated slave arms like the MT200 TAO (an evolution of the conventional wall-transmission mechanical telemanipulator (MSM)) as well as industrial robotic arms like the Stäubli RX robots. Both the MT200 TAO and Stäubli RX TAO telerobotics systems provide force-feedback and are now ready to be used as telemaintenance tools at the AREVA La Hague facilities. Two recent maintenance operations using these tools will be detailed at the end of this pape