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Sample records for altiplano sur bolivariano

  1. Andes Altiplano, Northwest, Argentina

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This view of the Andean Altiplano in northwest Argentina (25.5S, 68.0W) is dominated by heavily eroded older and inactive volcano peaks. Snow is more apparent on the south faces of the slopes where the sunlight is less direct and therefore, cooler. The Altiplano is a high altitude cold desert like the Tibetan Plateau but smaller in area. It is the inland extension of the hyperarid Atacama Desert of the west coast of South America.

  2. Andes Altiplano, South America

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Looking westward over the Andes Altiplano, (14.S, 72.5W) this panoramic view shows details of the deep river gorges cut into the mountains as they rose to their present heights of over 10,000 to 13,000 ft. over the past 20 million years. The eastern slopes of the Andes are heavily forested and form the headwaters of the Amazon River drainage basin. Smoke from logging or land clearing operations can be seen in the lower river valleys.

  3. Andes Altiplano, Northwest Argentina, South America

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This view of the Andes Altiplano in northwest Argentina (25.5S, 68.0W) is dominated by heavily eroded older and inactive volcano peaks. The altiplano is a high altitude cold desert like the Tibetan Plateau but smaller in area. It is an inland extension of the hyperarid Atacama Desert of the west coast of South America and includes hundreds of volcanic edifices (peaks, cinder cones, lava flows, debris fields, lakes and dry lake beds (salars).

  4. Changing climate in the Bolivian Altiplano

    NASA Astrophysics Data System (ADS)

    Thibeault, Jeanne Marie

    Rural agriculture in the Bolivian Altiplano is vulnerable to climate related shocks. Projections of eight precipitation and temperature extreme indices for the Altiplano are examined. Increases in observed warm nights and warm spells are consistent with increasing temperatures in the tropical Andes. Projections of warm nights, frost days, and heat waves are consistent with projected annual cycle temperature increases. Projected increases in precipitation extremes are consistent with trends at Patacamaya and annual cycle projections indicating a later rainy season characterized by less frequent, more intense precipitation. PDFs of Patacamaya precipitation suggest that precipitation changes may occur earlier than projected. The observed increase in frost days can be understood within the context of precipitation changes and increased radiative cooling. Consistencies between simulated and observed extremes suggest the projected directions of change are reliable. The ability of the CMIP3 models to simulate relationships between Altiplano precipitation anomalies and large-scale atmospheric variables for spring and summer is examined. A majority of models simulate an easterly/wet-westerly/dry relationship between upper-level winds and Altiplano precipitation in spring and summer, consistent with observations. Examination of future precipitation variability under conditions of greenhouse warming suggests the requirement of moisture transport from the east will not change. Atmospheric circulation changes associated with expansion of the Hadley circulation reduces the frequency of upper-level easterly winds, explaining springtime drying. Increased tropical tropospheric warming reduces the frequency of summertime upper-level easterly winds, explaining less frequent summertime rainfall. Springtime soil moisture is expected to decrease throughout the 21 st century, consistent with projections for increased temperature and decreased precipitation. Reductions in springtime soil

  5. Dust Storm, Andean Altiplano, South America

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Most of the land surface and the clouds in the foreground of this westerly looking view are over the South American Andean Altiplano at the frontier between Chile and Argentina (26.5S, 66.5W). Chile is to the west near the top of the photo just beyond the dry salt lake (Salar de Arizaro) at the upper right. Very strong winds are picking up dust and blowing it to the SE across mountain mountain ranges into the Chaco Austral region of Argentina.

  6. Endemic human fasciolosis in the Bolivian Altiplano.

    PubMed

    Parkinson, M; O'Neill, S M; Dalton, J P

    2007-05-01

    Fasciolosis, caused by trematodes of the genus Fasciola, is an emerging disease of humans. One of the highest levels of human fasciolosis hepatica is found amongst the indigenous Aymaran people of the Northern Bolivian Altiplano. A meta-analysis of epidemiological surveys from 38 communities in the region demonstrates that fasciolosis has been endemic in the region since at least 1984 and is a zoonosis of rural communities. Human and bovine fasciolosis is associated with the communities lying in the plain from Lake Titicaca to La Paz, predominantly in the Los Andes province. In Los Andes incidences of up to 67% of population cohorts were found, and prevalence is age-related with the highest infection rate in children aged 8-11 years.

  7. Paleozoic diamictites in the Peruvian Altiplano: evidence and tectonic implications

    NASA Astrophysics Data System (ADS)

    Díaz-Martínez, Enrique; Acosta, Harmuth; Cardenas, José; Carlotto, Víctor; Rodríguez, Rildo

    2001-11-01

    Striated and faceted clasts found within the diamictites of the San Gabán Formation immediately north of Ayaviri (southeast Peru) are interpreted as evidence for the late Ashgill-Llandovery glaciations in the Peruvian Altiplano, an area where this unit was previously considered not to be deposited. The Lower Paleozoic stratigraphic sequence cropping out in the area includes the Sandia, San Gabán, and Ananea Formations, and thus belongs to the Eastern Cordillera tectonostratigraphic domain, but within the Altiplano morphotectonic region. The marked difference between the Lower Paleozoic sequences of the Altiplano and Eastern Cordillera tectonostratigraphic domains suggests important tectonic shortening along the boundary fault zone during Andean Cenozoic deformation.

  8. Technology selection for MSW treatment in Altiplano areas using FMDM.

    PubMed

    Jiang, Jianguo; Lou, Zhiying; Hg, Siio; Duo, Ji; Li, Zhong

    2009-10-01

    There are special requirements for municipal solid waste (MSW) treatment caused by lower oxygen content and atmospheric pressure on the Altiplano. The intention of this paper was to analyse the applicability of various technologies to MSW treatment in the Altiplano and select the best one based on the current MSW collection modes and technical levels, using the Fuzzy Mathematical Decision Method (FMDM). Technologies including landfill, incineration, composting, and anaerobic digestion (AD) were compared. The results of the studies showed that AD technology is a new technology which is attractive in economic terms and helpful for environmental harmony. AD can solve the difficulties caused by a high content of organic matter in the MSW, lower atmospheric pressure and oxygen content on the Altiplano. Moreover, it can achieve reduction and recycling of the waste, thereby saving space for treatment and disposal. Using this technology, renewable energy can be recovered to save conventional fuel consumption and the emission of greenhouse gases can be reduced to improve the conservation of the local ecosystem. Putting AD into practice in the Altiplano may be the preferred method of MSW treatment.

  9. Technology selection for MSW treatment in Altiplano areas using FMDM.

    PubMed

    Jiang, Jianguo; Lou, Zhiying; Hg, Siio; Duo, Ji; Li, Zhong

    2009-10-01

    There are special requirements for municipal solid waste (MSW) treatment caused by lower oxygen content and atmospheric pressure on the Altiplano. The intention of this paper was to analyse the applicability of various technologies to MSW treatment in the Altiplano and select the best one based on the current MSW collection modes and technical levels, using the Fuzzy Mathematical Decision Method (FMDM). Technologies including landfill, incineration, composting, and anaerobic digestion (AD) were compared. The results of the studies showed that AD technology is a new technology which is attractive in economic terms and helpful for environmental harmony. AD can solve the difficulties caused by a high content of organic matter in the MSW, lower atmospheric pressure and oxygen content on the Altiplano. Moreover, it can achieve reduction and recycling of the waste, thereby saving space for treatment and disposal. Using this technology, renewable energy can be recovered to save conventional fuel consumption and the emission of greenhouse gases can be reduced to improve the conservation of the local ecosystem. Putting AD into practice in the Altiplano may be the preferred method of MSW treatment. PMID:19470531

  10. High Altiplano of the Andes, Chile and Argentina

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The dry desert climate of the high Altiplano of the South american Andes (27.0S, 68.5W) presents a stark landscape of lava flows from many extinct volcanoes and salars (dry lakebeds). Wind streaks across the surface are the result of strong prevailing WNW winds picking up fine particles of salt and volcanic ash, transporting it eastward. The small lakes in some of the basins have different colors because of varying salinity and algae activity.

  11. Interbasin underflow between closed Altiplano basins in Chile.

    PubMed

    Montgomery, Errol L; Rosko, Michael J; Castro, Santiago O; Keller, Barry R; Bevacqua, Paolo S

    2003-01-01

    Interbasin ground water movement of 200 to 240 L/sec occurs as underflow beneath a mountainous surface water divide separating the topographically higher Salar de Michincha from the topographically lower Salar de Coposa internally drained basins in the Altiplano of northern Chile. Salt-encrusted flats (salars) and saline lakes occur on the lowest parts of the basin floors and comprise the principal evaporative discharge areas for the basins. Because a surface water divide separates the basins, surface water drainage boundaries do not coincide with ground water drainage boundaries. In the region, interbasin ground water movement is usually not recognized, but occurs for selected basins, and at places is an important component of ground water budgets. With increasing development of water for mining industry and potential exportation of ground water from the Altiplano for use at coastal cities, demonstration and quantification of interbasin movement is important for assessment of sustainable ground water development in a region of extreme aridity. Recognition and quantification of interbasin ground water underflow will assist in management of ground water resources in the arid Chilean Altiplano environment.

  12. Hydrocarbon potential of Altiplano and northern Subandean, Bolivia

    SciTech Connect

    Edman, J.D.; Kirkpatrick, J.R.; Lindsey, D.D.; Lowell, J.D.; Cirbian, M.; Lopez, M.

    1989-03-01

    Seismic, stratigraphic, structural, and geochemical data from the Altiplano, northern Subandean, and northern plains of Bolivia were interpreted in order to evaluate the exploration potential of each province. Identification of three possible source rock intervals, primarily the Devonian and secondarily the Permian and Cretaceous, was used as the basis for recognizing active hydrocarbon systems. For those areas containing source intervals, their analysis revealed that possible reservoir and seal units range in age from Paleozoic to Tertiary; the majority of structures, however, are Eocene or younger. With these general concepts in mind, traps were identified in all three sedimentary provinces. In the northern Altiplano, the most prospective area is along the eastern margin near a southwest and west-vergent thrust belt where hanging-wall anticlines and a warped Eocene-Oligocene(.) unconformity surface form the most likely potential traps. In the central and southern Altiplano, both thrust-related and wrench-related structures present possible exploration targets. In the northern Subandean and Beni plains north of the Isiboro-Chapare area, traps can be classified into two broad groups. First, there are a wide variety of structural traps within the northern Subandean thrust belt, the most attractive of which are footwall structures that have been shielded from surface flushing by hanging-wall strata. Second, in the plains just northeast of the thrust belt, hydrocarbons sourced from the remnant Paleozoic basin may have migrated onto the Isarsama and Madidi highs.

  13. Composition and thickness of the southern Altiplano crust, Bolivia

    SciTech Connect

    Zandt, G.; Velasco, A.A. ); Beck, S.L. )

    1994-11-01

    Slant stacking of broadband seismograms recorded in the western United States for two 1993 intermediate-depth earthquakes that occurred near the Bolvia-Argentina-Chile borders reveals small but clear precursors to both the compressional (P) wave and shear (S) wave depth phases. We interpret and model these precursors as underside reflections from the thickened Andean Altiplano crust. We model the crustal structure of the Altiplano with a grid-search technique to match the timing and amplitudes of the depth phases and precursors in the waveforms of both the P wave and S wave. Our best-fit model has an average crust velocity of 5.9-6.0 km/s, a crustal V[sub p]/V[sub s] of 1.6, a crustal thickness of 75-80 km, and a high-velocity (V[sub p] = 8.4 km/s), high-V[sub p]/V[sub s] (1.9) mantle wedge. Assuming isotropy, the low V[sub p]/V[sub s] ratio of 1.6 for the crust corresponds to an anomalously low Poisson's ratio of 0.18. Such a low value, in conjunction with the low average V[sub p] estimate, is consistent only with a felsic composition and high upper-crustal temperatures. The finding of a thick felsic crust overlying a high-velocity mantle supports models of Altiplano uplift due predominantly to crustal shortening as opposed to mafic magmatic addition and is inconsistent with recent mantle delamination. 19 refs., 3 figs., 1 tab.

  14. Altiplano-Puna volcanic complex of the central Andes

    NASA Technical Reports Server (NTRS)

    De Silva, S. L.

    1989-01-01

    A model is presented accounting for many features of the Altiplano-Puna volcanic complex situated in the Central Volcanic Zone of the Andes which contains 50 recently active volcanoes. The dominant elements of the complex are several large nested caldera complexes which are the source structures for the major regionally distributed ignimbrite sheets that characterize the complex. The study of the complex reveals the importance of the intersection of subsidiary axis-oblique tectonic trends related to regional stress fields peculiar to individual oceanic ridge sections with the axis-parallel trends predominant at all spreading centers in localizing hydrothermal discharge zones.

  15. A magnetotelluric survey in the northern Bolivian Altiplano

    SciTech Connect

    Ritz, M. ); Bondoux, F. ); Herail, G.; Sempere, T. )

    1991-03-01

    Magnetotelluric (MT) measurements were performed at 9 sites on the northern Bolivian Altiplano in an attempt to determine thicknesses of the Cainozoic sedimentary infill and to characterize the underlying crust. At some of the sites the MT soundings show complications due to static shift effects caused by local, surficial heterogeneities. Preliminary one-dimensional (1D) modeling of the data based on the impedance tensor determinant parameters was undertaken for sites considered to be free of static effects, and was followed by 2D modeling. The model obtained indicates, from the surface downward, three important geoelectrical units, namely (1) a very low-resistivity layer (1-6 ohm-m) consisting of late Cainozoic volcanic rocks and/or Tertiary-Cretaceous sedimentary rocks 1-4 km in thickness, (2) a crustal resistive zone (about 200 ohm-m), and (3) a lower crustal or uppermost mantle conductor (less than 10 ohm-m) at depths of 40-45 km which might be related to partial melting. This model is consistent with the geological model according to which the Altiplano formed as a synorogenic basin showing abrupt changes in depositional thicknesses across thrust faults.

  16. Balantidiasis in Aymara children from the northern Bolivian Altiplano.

    PubMed

    Esteban, J G; Aguirre, C; Angles, R; Ash, L R; Mas-Coma, S

    1998-12-01

    Balantidium coli infection was coprologically studied in 2,124 Aymara children 5-19 years of age from the schools of 22 communities of the northern Bolivian Altiplano over a five-year period. Infection with B. coli was found in 11 of the communities surveyed, with prevalences of 1.0-5.3% (overall prevalence=1.2%). The prevalences observed are some of the highest reported and did not differ significantly among the various age groups or between boys and girls. These prevalences, the apparent absence of symptoms or signs of illness due to this parasite in the schoolchildren surveyed at the time of stool sampling, and the consistency of stool samples of the infected students suggest that they are apparently asymptomatic carriers. Infection with B. coli must be considered as an endemic anthropozoonosis in the area studied. A relationship between B. coli infection and Altiplanic pigs is suggested.

  17. Balantidiasis in Aymara children from the northern Bolivian Altiplano.

    PubMed

    Esteban, J G; Aguirre, C; Angles, R; Ash, L R; Mas-Coma, S

    1998-12-01

    Balantidium coli infection was coprologically studied in 2,124 Aymara children 5-19 years of age from the schools of 22 communities of the northern Bolivian Altiplano over a five-year period. Infection with B. coli was found in 11 of the communities surveyed, with prevalences of 1.0-5.3% (overall prevalence=1.2%). The prevalences observed are some of the highest reported and did not differ significantly among the various age groups or between boys and girls. These prevalences, the apparent absence of symptoms or signs of illness due to this parasite in the schoolchildren surveyed at the time of stool sampling, and the consistency of stool samples of the infected students suggest that they are apparently asymptomatic carriers. Infection with B. coli must be considered as an endemic anthropozoonosis in the area studied. A relationship between B. coli infection and Altiplanic pigs is suggested. PMID:9886201

  18. Rapid regional surface uplift of the northern Altiplano plateau revealed by multiproxy paleoclimate reconstruction

    NASA Astrophysics Data System (ADS)

    Kar, Nandini; Garzione, Carmala N.; Jaramillo, Carlos; Shanahan, Timothy; Carlotto, Victor; Pullen, Alex; Moreno, Federico; Anderson, Veronica; Moreno, Enrique; Eiler, John

    2016-08-01

    The central Altiplano is inferred to have experienced ∼ 2.5 ± 1km surface uplift between ∼10 and 6 Ma, while the southern Altiplano experienced a similar magnitude of surface uplift that began earlier, between ∼16 and 9 Ma. To properly constrain the along strike timing of the Altiplano plateau surface uplift, it is necessary to know how and when the northernmost part of the Altiplano plateau evolved. We reconstruct the paleoclimate and infer the corresponding paleoelevation from the Miocene-Pliocene deposits of the Descanso-Yauri basin (14-15°S) in the northernmost part of the Altiplano plateau using 4 different proxies, including carbonate clumped isotope composition (i.e., Δ47 values), carbonate δ18Oc, leaf wax δDwax and pollen assemblages from paleosol, lacustrine and palustrine carbonates and organic-rich sediments. The isotopic signatures reflect past climate conditions of mean annual air temperature (Δ47) and meteoric water isotope values (δ18Oc, δDwax). Our results show that the northernmost plateau remained at low elevation (0.9 ± 0.8 to 2.1 ± 0.9km) until late Miocene time (∼9 Ma) characterized by ∼15 °C warmer than modern temperature (mean annual air temperature of 23 ± 4 °C, 2σ), low elevation vegetation and precipitation signature with reconstructed □ δ18Omw (VSMOW) of - 8.3 ± 2.0 ‰ (2 σ) from carbonate (δ18Oc) and - 8.6 ± 1.8 ‰ (2 σ) from leaf wax (δDwax). Modern elevations of 4 km were not reached until 5.4 ± 1.0Ma, as indicated by a negative shift in δDwax (VSMOW) from - 143.4 ± 12.8 ‰ (2 σ) to - 209.2 ± 21.1 ‰ (2 σ) between 9.1 ± 0.7 and 5.4 ± 1.0Ma. The timing of surface uplift of the northernmost Altiplano is consistent with the evidence for late Miocene surface uplift of the central Altiplano (16-19°S) between 10 and 6 Ma, and indicates that regional scale uplift in the northern-central plateau significantly postdates the onset of surface uplift in the southern Altiplano (19-22°S) between ∼16

  19. Gravimetric imaging of partially molten bodies beneath the Bolivian Altiplano

    NASA Astrophysics Data System (ADS)

    del Potro, R.; Diez, M.; Gottsmann, J.; Camacho, A. J.; Sunagua, M.

    2011-12-01

    The presence of partial melt in the Earth's crust causes a decrease in density, and hence a density contrast, that generates a potential field anomaly. Gravimetric techniques can quantify such an anomaly and invert its signature to produce a subsurface density distribution model, from which images of anomalous density bodies can be isolated. Here, we present a 3D gravimetric image of four deep-rooted negative density bodies in the Central Volcanic Zone of the Andes in southern Bolivia, which we interpret to contain partial melt. The underlying gravimetric data were obtained by the combination of 143 new with 60 existing observation from previous regional surveys. The survey covers an area of ~5000 km2 that comprises the Central Andean Bouguer anomaly minima of about -450 μGal. After standard data reduction, the local residual gravity signal was inverted using a priori determined plausible density contrasts (±50 to ±300 kg m-3). The inversion routine builds a subsurface model (defined by the 3D aggregation of parallel-piped cells) based on a controlled 'growth' process of anomalous density bodies by means of an exploratory approach. Non-uniqueness is addressed by favouring solutions that balance minimum residuals and minimum number of anomalous bodies with minimum anomalous mass. Within the range of assumed density contrasts, all inversion models show the presence of the deep-rooted low-density bodies, providing a significant confidence level to the inversion results. Our favoured 3D model of the anomalous bodies is obtained from a negative density contrast of 150 kg m-3 that corresponds to <30 vol% partial melt of dacitic composition. These partially molten bodies appear to connect the Altiplano-Puna Magma Body (AMPB) at ~20 km depth, to shallower (~5 km) pre-eruption levels beneath the Altiplano-Puna Volcanic Complex (APVC). One of the bodies is located beneath a large on-going ground uplift centred at Uturuncu volcano and the modelled ground deformation source

  20. Radar-visible wind streaks in the Altiplano of Bolivia

    NASA Technical Reports Server (NTRS)

    Greeley, R.; Christensen, P.

    1984-01-01

    Isolated knobs that are erosional remnants of central volcanoes or of folded rocks occur in several areas of the Altiplano are visible on both optical and images. The optically visible streaks occur in the immediate lee of the knobs, whereas the radar visible streaks occur in the zone downwind between the knobs. Aerial reconnaissance and field studies showed that the optically visible streaks consist of a series of small ( 100 m wide) barchan and barchanoid dunes, intradune sand sheets, and sand hummocks (large shrub coppice dunes) up to 15 m across and 5 m high. On LANDSAT images these features are poorly resolved but combine to form a bright streak. On the radar image, this area also appears brighter than the zone of the radar dark streak; evidently, the dunes and hummocks serve as radar reflectors. The radar dark streak consists of a relatively flat, smooth sand sheet which lacks organized aerolian bedforms, other than occasional ripples. Wind velocity profiles show a greater U value in the optically bright streak zone than in the radar dark streak.

  1. Use of remote sensing and GIS to identify Flamingo habitat in the Argentine Altiplano

    USGS Publications Warehouse

    Boyle, Susan C.; Hoffer, Roger M.; Boyle, Terence P.; Bucher, Enrique H.

    1992-01-01

    The Argentine altiplano is a remote area which has never been adequately mapped. It is an arid region with harsh climate, little vegetation, sparse population, and an average elevation of over 3,500 feet. Little is known about the large populations of three species of flamingos which nest and feed in the altiplano lakes. In a study funded by the National Geographic Society satellite data (Landsat MSS and TM data) were used to map the location of major water bodies and to analyze the spectral characteristics of the aquatic ecosystems in the altiplano. A comparison of the two images revealed dramatic changes in the size, depth, and spectral reflectance of the lakes utilized by the flamingos.

  2. Mineral status of llamas and sheep in the Bolivian Altiplano.

    PubMed

    Espinoza, J E; McDowell, L R; Rodriguez, J; Loosli, J K; Conrad, J H; Martin, F G

    1982-12-01

    An experiment was conducted in the highlands (Altiplano) of Bolivia to establish the specific mineral status for growing llamas compared to sheep grazing unfertilized, native pastures. Animal tissues (plasma, liver and bone), forage and soil samples were collected during the wet and dry seasons and analyzed for mineral contents. During the wet season, forages were higher (P less than 0.05) in Ca, K, Fe and protein. Percent borderline to deficient forage concentrations during the wet and dry seasons, respectively, were found as follows: protein (less than 7.0%) 20 and 53; CCa (less than 0.30%) 10 and 40; Cu (less than 5 ppm) 20 and 47; K (less than 0.5%) 10 and 20; Mg (less than 0.08%) 10 and 20; Na (less than 0.1%) 30 and 69; P (less than 0.25%) 100 and 100; Zn (less than 30 ppm) 60 and 80; and Se (less than 0.1 ppm) 90 and 93% of the total forages, respectively. Concentrations of liver Mg, Co, Mn, Mo, Se and Zn, plasma Mg and Cu and rib (percent ash) Ca, Mg and P were all higher (P less than 0.05) during the wet than in the dry season. Compared to llamas, sheep had higher (P les than 0.05) concentrations of plasma Ca, Cu, Fe and Zn, rib (milligram/milliliter) P, Mg and Zn and liver Fe, but lower (P less than 0.05) concentrations of liver Co, Cu, Mn and MO. On the basis of forage and animal tissue analyses, the nutrients protein, P, Ca, Zn, Na and Se would be insufficient for optimum production of grazing livestock in the high plains of Bolivia.

  3. Climate change and potato cropping in the Peruvian Altiplano

    NASA Astrophysics Data System (ADS)

    Sanabria, J.; Lhomme, J. P.

    2013-05-01

    The potential impacts of climate change on potatoes cropping in the Peruvian highlands (Altiplano) is assessed using climate projections for 2071-2100, obtained from the HadRM3P regional atmospheric model of the Hadley Centre. The atmospheric model is run under two different special report on emission scenarios: high CO2 concentration (A2) and moderate CO2 concentration (B2) for four locations situated in the surroundings of Lake Titicaca. The two main varieties of potato cultivated in the area are studied: the Andean potato ( Solanum tuberosum) and the bitter potato ( Solanum juzepczukii). A simple process-oriented model is used to quantify the climatic impacts on crops cycles and yields by combining the effects of temperature on phenology, of radiation and CO2 on maximum yield and of water balance on yield deficit. In future climates, air temperature systematically increases, precipitation tends to increase at the beginning of the rainy season and slightly decreases during the rest of the season. The direct effects of these climatic changes are earlier planting dates, less planting failures and shorter crop cycles in all the four locations and for both scenarios. Consequently, the harvesting dates occur systematically earlier: roughly in January for the Andean potato instead of March in the current situation and in February for the bitter potato instead of April. Overall, yield deficits will be higher under climate change than in the current climate. There will be a strong negative impact on yields for S. tuberosum (stronger under A2 scenario than under B2); the impact on S. juzepczukii yields, however, appears to be relatively mixed and not so negative.

  4. Sombrero uplift above the Altiplano-Puna Magma Body: evidence of a ballooning mid-crustal diapir.

    PubMed

    Fialko, Yuri; Pearse, Jill

    2012-10-12

    The Altiplano-Puna ultralow-velocity zone in the central Andes, South America, is the largest active magma body in Earth's continental crust. Space geodetic observations reported an uplift in the Altiplano-Puna proper at a rate of ~10 mm/year; however, the nature of the inferred inflation source has been uncertain. We present data showing that the uplift has persisted at a nearly constant rate over the past two decades, and is surrounded by a broad zone of subsidence. We show that the ongoing uplift and peripheral subsidence may result from a large mid-crustal diapir fed by partial melt from the Altiplano-Puna Magma Body.

  5. Thermal and geodynamic contributions to the elevation of the Altiplano-Puna plateau

    NASA Astrophysics Data System (ADS)

    Prezzi, Claudia; Iglesia Llanos, María Paula; Götze, Hans-Jürgen; Schmidt, Sabine

    2014-12-01

    The most remarkable feature of the Central Andes is the Altiplano-Puna plateau. This plateau is characterized by 3.5 km average elevation, approximately 70 km crustal thickness and very high heat flow. The upper mantle structure changes along strike below the plateau. The upper mantle below the Puna becomes hotter, and the lithosphere becomes thinner and weaker. These features suggest that thermal isostasy could play a role in the compensation of the Altiplano-Puna. Thermal isostasy is the geodynamic process whereby regional variations in the lithospheric thermal regime cause changes in elevation. Elevation changes result from variations in rock density in response to thermal expansion. The aim of this study is to estimate the thermal and geodynamic contributions to the elevation. While the thermal component of the Altiplano elevation would be of 1 km, the thermal contribution to the southern Puna elevation would be of 1.5 km. However, in the case of the southern Puna a portion of the actual topography (∼20%) cannot be explained considering only compositional and thermal effects, suggesting additional geodynamical support. The obtained results suggest that the thermal state of the lithosphere would play a significant role in the elevation of the Central Andes, and may be responsible of some of the geological differences displayed by the Altiplano and the Puna.

  6. Evaluating processes and rates of surface denudation at the Eastern Altiplano margin, Bolivia

    NASA Astrophysics Data System (ADS)

    Hippe, Kristina; Kober, Florian; Zeilinger, Gerold; Ivy-Ochs, Susan; Kubik, Peter; Maden, Colin; Wieler, Rainer

    2010-05-01

    For the Andes Mountains, it has been hypothesized that variations in climate govern variations in erosional intensity that acts as a first-order control on topographic evolution [1]. However, to test these geodynamic models the erosional history of the mountains has to be quantified independently. While absolute erosion rates are known for the Eastern and Western Cordillera, few data exists on erosional processes and rates on the large, internally drained, high-elevation Altiplano plateau. We investigate the Late Quaternary erosional history of the eastern Altiplano based on paired terrestrial cosmogenic nuclide analyses (10Be and 26Al). The Eastern margin of the Bolivian Altiplano is a flat, low-relief landscape with erosion dominated by diffusive hillslope processes and eolian processes. Low precipitation with a strong interannual variability causes episodic fluvial transport of sediment in often small, ephemeral channels. For 13 river sediment samples collected from catchments along the Altiplano margin, catchment wide denudation (CWD) rates have been obtained by 10Be and 26Al. CWD rates based on 10Be are very low and vary between 0.003 to 0.026 mm/yr, with an integration time of 24-230 ky. 26Al data indicate also low, though slightly higher single CWD rates between 0.004 to 0.032 mm/yr. In combination with 10Be, this suggests a complex exposure history with a significant component of sediment storage. These results agree with geomorphological observations of (a) very low slopes, (b) low relief and (c) transient river channels that might account for locally and/or temporarily ineffective erosional and transport processes on the eastern Altiplano. Inter-catchment comparison shows a positive correlation between CWD rates and geomorphometric catchment parameters, but also further influence by lithology and anthropogenic interferences. The slow and complex erosion transport processes on the Altiplano differ significantly from those of the neighbouring Rio La Paz

  7. Climate trends and projections for the Andean Altiplano and strategies for adaptation

    NASA Astrophysics Data System (ADS)

    Valdivia, C.; Thibeault, J.; Gilles, J. L.; García, M.; Seth, A.

    2013-04-01

    Climate variability and change impact production in rainfed agricultural systems of the Bolivian highlands. Maximum temperature trends are increasing for the Altiplano. Minimum temperature increases are significant in the northern region, and decreases are significant in the southern region. Producers' perceptions of climate hazards are high in the central region, while concerns with changing climate and unemployment are high in the north. Similar high-risk perceptions involve pests and diseases in both regions. Altiplano climate projections for end-of-century highlights include increases in temperature, extreme event frequency, change in the timing of rainfall, and reduction of soil humidity. Successful adaptation to these changes will require the development of links between the knowledge systems of producers and scientists. Two-way participatory approaches to develop capacity and information that involve decision makers and scientists are appropriate approaches in this context of increased risk, uncertainty and vulnerability.

  8. [Intestinal parasitoses in children of an Indian community of Bolivian altiplano].

    PubMed

    Basset, D; Gaumerais, H; Basset-Pougnet, A

    1986-01-01

    A survey about motion parasitosis has been carried out on one hundred Indians (Quechua ethnic group) living in a hamlet called Amarete located in the Bolivian Altiplano. This community is living in a place difficult to reach (11,100 feet) where many pre-Colombian traditions are still alive. All children were parasitized, 75% of them were carrier of 3 to 5 parasites. Infestation with ascaris (91%) is the most frequent and the risks of getting amebic dysentery (Entamoeba histolytica 41%) and balantidial (Balantidium coli 8%) are high. Many other parasites (8 kinds of protozoa , 5 kinds of helminths) can be observed; more especially, we noticed that 20% of the pupils used to be carrier operculated eggs. Tenia embryophores (more probably Taenia solium found in 2 children) made us aware of possibilities of cysticercosis. An other problem lays on general hygiene and hygiene of the water since feces danger is responsible of important parasitologic loads. Results are compared with a fecal study carried out on a population from the Altiplano region but living now in the plain. Amazonian Indian population in previous or recent contact with occidental civilization show the same variations of parasitologic repartition between Amarete hamlet and the transplanted population of Altiplano region. The role played by the acculturation could be discussed.

  9. Fascioliasis of livestock and snail host for Fasciola in the Altiplano Region of Bolivia.

    PubMed

    Ueno, H; Arandia, R; Morales, G; Medina, G

    1975-01-01

    Fascioliasis caused by Fasciola hepatica was a serious problem for sheep and alpacas in the Altiplano Region of Bolivia. In some provinces close to Lake Titicaca, the raising of sheep was forced to discontinue, because infection with the fluke made it unprofitable and almost impossible. It was proved that in the Altiplano Region, two species of freshwater snails, Lymnaea viatrix and L. cubensis var., served as intermediate hosts for F. hepatica. In some subtropical areas of Bolivia, these snails could not be found, although other Lymnaea sp. was widely distributed there. As it is possible for Lymnaea sp. to be intermediate host for the fluke, further studies are required on the identification. Acute fascioliasis of sheep occurred in the Altiplano Region principally during a period from May to July, or the dry season. In some areas, the mortality rate of infected sheep was roughly estimated as 15 to 25% annually. Contamination with Fasciola metacercariae of herbage and semi-aquatic plants grown in a swamp in one of these areas was biologically assessed, using guinea pigs. Plants of Compositae and Eleocharis sp. were contaminated most intensely and those of Senicio sp. and Vallisneria sp. carried a fairly large number of cysts, while plants of Scirpus sp. and Ranunclaceae carried only a few cysts. No signs of Fasciola infection were observed in any animal given the plants of Liliaceae.

  10. The Bolivian "Altiplano" and "Valle" sheep are two different peripatric breeds.

    PubMed

    Parés-Casanova, Pere M; Pérezgrovas Garza, Raúl

    2014-06-01

    Forty-nine sheep belonged to the Andean Altiplano region ("Altiplano") and 30 in the lowland regions of Bolivia ("Valle"), aged 1 to 4 years, were wool sampled to determine the extent of difference between these local breeds. Fibre length and the percentage of each type of fibre (long-thick, short-thin and kemp), yield and fibre diameter were measured. There was a highly significant difference between the two sheep populations that were not clearly separated in the first two principal component of a principal components analysis (PC); the first PC explained 67.1 % and the second PC explained 26.6 % of the total variation. The variables that contributed most to the separation of the sheep populations were the percentage of long-thick and short-thin fibres in the first PC and yield in the second PC. A discriminant analysis, which was used to classify individuals with respect to their breeding, achieved an accurate classification rate of 84.2 %. Thus, the Altiplano and Valle sheep must be viewed as two closely peripatric breeds rather than different "ecotypes", as more than 80 % could be correctly assigned to one of the breeds; however, the differences are based on composition of long-thick and short-thin fibres and yield after alcohol scouring.

  11. The Bolivian "Altiplano" and "Valle" sheep are two different peripatric breeds.

    PubMed

    Parés-Casanova, Pere M; Pérezgrovas Garza, Raúl

    2014-06-01

    Forty-nine sheep belonged to the Andean Altiplano region ("Altiplano") and 30 in the lowland regions of Bolivia ("Valle"), aged 1 to 4 years, were wool sampled to determine the extent of difference between these local breeds. Fibre length and the percentage of each type of fibre (long-thick, short-thin and kemp), yield and fibre diameter were measured. There was a highly significant difference between the two sheep populations that were not clearly separated in the first two principal component of a principal components analysis (PC); the first PC explained 67.1 % and the second PC explained 26.6 % of the total variation. The variables that contributed most to the separation of the sheep populations were the percentage of long-thick and short-thin fibres in the first PC and yield in the second PC. A discriminant analysis, which was used to classify individuals with respect to their breeding, achieved an accurate classification rate of 84.2 %. Thus, the Altiplano and Valle sheep must be viewed as two closely peripatric breeds rather than different "ecotypes", as more than 80 % could be correctly assigned to one of the breeds; however, the differences are based on composition of long-thick and short-thin fibres and yield after alcohol scouring. PMID:24604105

  12. [Intestinal parasitoses in children of an Indian community of Bolivian altiplano].

    PubMed

    Basset, D; Gaumerais, H; Basset-Pougnet, A

    1986-01-01

    A survey about motion parasitosis has been carried out on one hundred Indians (Quechua ethnic group) living in a hamlet called Amarete located in the Bolivian Altiplano. This community is living in a place difficult to reach (11,100 feet) where many pre-Colombian traditions are still alive. All children were parasitized, 75% of them were carrier of 3 to 5 parasites. Infestation with ascaris (91%) is the most frequent and the risks of getting amebic dysentery (Entamoeba histolytica 41%) and balantidial (Balantidium coli 8%) are high. Many other parasites (8 kinds of protozoa , 5 kinds of helminths) can be observed; more especially, we noticed that 20% of the pupils used to be carrier operculated eggs. Tenia embryophores (more probably Taenia solium found in 2 children) made us aware of possibilities of cysticercosis. An other problem lays on general hygiene and hygiene of the water since feces danger is responsible of important parasitologic loads. Results are compared with a fecal study carried out on a population from the Altiplano region but living now in the plain. Amazonian Indian population in previous or recent contact with occidental civilization show the same variations of parasitologic repartition between Amarete hamlet and the transplanted population of Altiplano region. The role played by the acculturation could be discussed. PMID:3731367

  13. Crustal structure of the Altiplano from broadband regional waveform modeling: Implications for the composition of thick continental crust

    NASA Astrophysics Data System (ADS)

    Swenson, Jennifer L.; Beck, Susan L.; Zandt, George

    2000-01-01

    We have modeled the full waveforms from six intermediate-depth and two shallow earthquakes recorded at regional distances by the BANJO Broadband Andean Joint Experiment (BANJO) and Seismic Exploration of the Deep Altiplano (SEDA) portable seismic networks in the central Andes. In this study we utilize data from those BANJO and SEDA stations located within the Altiplano and Eastern Cordillera. We used reflectivity synthetic seismograms and a grid search to constrain four parameters of the Altiplano-Eastern Cordillera lithosphere: crustal thickness, average crustal velocity (Vp), and crustal and upper mantle Poisson's ratios (σcrust and σmantle). Using our grid search, we investigated the crustal and upper mantle structure along 36 individual event station paths and applied forward modeling to 56 event station paths. Robust models for the Altiplano that provide the best overall fit between the data and synthetic seismograms are characterized by an average Vp of 5.75-6.25 km/s, crustal thicknesses of 60-65 km, σcrust = 0.25, and σmantle = 0.27-0.29. We find a north-south variation in the structure of the Altiplano, with the crust south of the BANJO transect characterized by either lower than average crustal P wave velocities or a slightly higher σcrust relative to crust north of the BANJO transect. These results are consistent with a model of crustal thickening caused predominantly by tectonic shortening of felsic crust, rather than by underplating or magmatic intrusion from the mantle.

  14. Geochemistry of Bolivian salars, Lipez, southern Altiplano: Origin of solutes and brine evolution

    SciTech Connect

    Risacher, F. ); Fritz, B. )

    1991-03-01

    This paper focuses on poorly understood processes related to saline lakes, or salars, of the southern Bolivian Altiplano. A morphologic classification system is described, and the origin of solutes in the inflow waters is discussed. Next, the actual chemical evolution of these inflow waters is compared with their theoretical evolution based on thermodynamic equilibria. The water chemistry of a specific sequence of evaporating waters is then scrutinized to determine which processes are responsible for a significant discrepancy which is apparent between the measured and the calculated evolution.

  15. Regional distance shear-coupled PL propagation within the northern Altiplano, central Andes

    NASA Astrophysics Data System (ADS)

    Swenson, Jennifer L.; Beck, Susan L.; Zandt, George

    1999-12-01

    Properties of the shear-coupled P wavetrain (SPL) from regional earthquakes provide important information about the structure of the crust and upper mantle. We investigate broad-band seismic data from intermediate-depth earthquakes and develop a grid search technique using synthetic seismograms to study the sensitivity of SPL and to model the crustal structure of the northern Altiplano, central Andes. Waveforms from an earthquake that occurred on 1994 December 12 within the Nazca slab beneath the Altiplano display a clear SPL wavetrain at the temporary stations deployed during the BANJO and SEDA experiments. We relocate this event and determine the moment tensor by inverting the complete long-period waveforms. With these source parameters fixed, we perform sensitivity analyses using a reflectivity technique to compute synthetic seismograms at a distance of 313 km (BANJO station 2, SALI). We find that, at this distance, the long-period SPL wavetrain is sensitive to the following model parameters, in order of decreasing sensitivity: crustal VP/VS, mantle VP/VS, average crustal velocity, crustal thickness, focal depth, distance (location), crustal Qα and Qβ, and mantle velocity. We develop a grid search method to investigate the four parameters of the crust/upper mantle model to which the synthetic seismograms are most sensitive at SALI (crustal VP/VS, mantle VP/VS, average crustal velocity, crustal thickness). Trade-offs exist among all four of the model parameters, resulting in a range of acceptable crustal models that provide excellent fits between the data and synthetic seismograms in the passband of 15-100 s at a single station. However, by using data at a range of distances (150-450 km) we find that the model that provides the best overall fit between the data and synthetic seismograms, and thus best approximates the average characteristics of the crust and upper mantle structure of the northern Altiplano, is characterized by an average crustal velocity of 6

  16. Tropical climate changes at millennial and orbital timescales on the Bolivian Altiplano.

    PubMed

    Baker, P A; Rigsby, C A; Seltzer, G O; Fritz, S C; Lowenstein, T K; Bacher, N P; Veliz, C

    2001-02-01

    Tropical South America is one of the three main centres of the global, zonal overturning circulation of the equatorial atmosphere (generally termed the 'Walker' circulation). Although this area plays a key role in global climate cycles, little is known about South American climate history. Here we describe sediment cores and down-hole logging results of deep drilling in the Salar de Uyuni, on the Bolivian Altiplano, located in the tropical Andes. We demonstrate that during the past 50,000 years the Altiplano underwent important changes in effective moisture at both orbital (20,000-year) and millennial timescales. Long-duration wet periods, such as the Last Glacial Maximum--marked in the drill core by continuous deposition of lacustrine sediments--appear to have occurred in phase with summer insolation maxima produced by the Earth's precessional cycle. Short-duration, millennial events correlate well with North Atlantic cold events, including Heinrich events 1 and 2, as well as the Younger Dryas episode. At both millennial and orbital timescales, cold sea surface temperatures in the high-latitude North Atlantic were coeval with wet conditions in tropical South America, suggesting a common forcing.

  17. Evolving in thin air--lessons from the llama fetus in the altiplano.

    PubMed

    Llanos, Aníbal J; Riquelme, Raquel A; Herrera, Emilio A; Ebensperger, Germán; Krause, Bernardo; Reyes, Roberto V; Sanhueza, Emilia M; Pulgar, Víctor M; Behn, Claus; Cabello, Gertrudis; Parer, Julian T; Giussani, Dino A; Blanco, Carlos E; Hanson, Mark A

    2007-09-30

    Compared with lowland species, fetal life for mammalian species whose mothers live in high altitude is demanding. For instance, fetal llamas have to cope with the low fetal arterial PO2 of all species, but also the likely superimposition of hypoxia as a result of the decreased oxygen environment in which the mother lives in the Andean altiplano. When subjected to acute hypoxia the llama fetus responds with an intense peripheral vasoconstriction mediated by alpha-adrenergic mechanisms plus high plasma concentrations of catecholamines and neuropeptide Y (NPY). Endothelial factors such as NO and endothelin-1 also play a role in the regulation of local blood flows. Unlike fetuses of lowland species such as the sheep, the llama fetus shows a profound cerebral hypometabolic response to hypoxia, decreasing cerebral oxygen consumption, Na-K-ATPase activity and temperature, and resulting in an absence of seizures and apoptosis in neural cells. These strategies may have evolved to prevent hypoxic injury to the brain or other organs in the face of the persistent hypobaric hypoxia of life in the Andean altiplano.

  18. Lateglacial climate reconstruction on the Bolivian Altiplano inferred from paleoglaciers and paleolakes

    NASA Astrophysics Data System (ADS)

    Martin, Léo; Blard, Pierre-Henri; Lavé, Jérôme; Prémaillon, Mélody; Jomelli, Vincent; Brunstein, Daniel; Lupker, Maarten; Charreau, Julien; Mariotti, Véronique; Condom, Thomas; Bourles, Didier

    2016-04-01

    Recent insights shed light on the global mechanisms involved in the abrupt oscillations of the Earth climate for the Late Glacial Maximum (LGM) to Holocene period (Zhang et al., 2014; Banderas et al., 2015). Yet the concomitant patterns of regional climate reorganization on continental areas are for now poorly documented. Particularly, few attempts have been made to propose temporal reconstructions of the regional climate variables in the High Tropical Andes, a region under the influence of multiple global climate forcings (Jomelli et al., 2014). We present new glacial chronologies from four sites of the Bolivian Altiplano: the Wara-Wara valley (17.3°S - 66.1°W), the Zongo valley (16.3°S - 68.1°W), the Cerro Tunupa (19.8°S - 67.6°W) and the Nevado Sajama (18.1°S 68.9°W). These chronologies are based on Cosmic Ray Exposure dating (CRE) from an exceptional suite of recessive moraines. These new data permitted to refine existing chronologies of Smith et al., 2005; Zech et al., 2010 and Blard et al., 2009. In both sites, glaciers recorded stillstand episodes synchronous with cold events such as the Henrich 1 event, the Younger Dryas and the Antarctic Cold Reversal. Since the nearby Altiplano basin registered lake level variations over the same period, we were able to apply a joint modelling of glaciers Equilibrium Line Altitude (ELA) and lake budget. This method permits to derive a temporal evolution of temperature and precipitation for the four sites. These new reconstructions show for all sites that glaciers of the Tropical Andes were influenced by the major climatic events of the Northern and Southern Hemispheres. Furthermore, the temperature variability observed at high latitudes results in these tropical latitudes in major precipitation variability whereas the lateglacial temperature patterns remain globally monotonic. This conversion of global temperature variability into regional precipitation variability support the idea that North Hemisphere cold

  19. Physical growth of Aymara children in a herding community of the Bolivian Altiplano.

    PubMed

    Kim, S W; Kashiwazaki, H; Imai, H; Moji, K; Takemoto, T; Orias-Rivera, J

    1991-12-01

    In a small agropastoral Aymara community called Wariscata in the Andean Altiplano of Bolivia, anthropometric measurements were made in 1988. In comparison with those of published data for the other rural and urban Andean populations (Aymara, Quechua and Mestizo at high and low altitudes), the Aymara children of Wariscata were taller and heavier than other rural high altitude native children, but similar in height to urban high altitude children. This is possibly due to secular change of growth accompanied with nutritional improvement that has taken place in recent years. Chest width and depth had similar values to those in other Aymara children. But, Aymara children in Wariscata of both sexes had smaller chest dimensions (depth and width) than those of Quechua children. However, these ethnic differences in chest dimensions were not reflected in the adult Aymara and Quechua, suggesting different process of chest growth in Aymara and Quechua populations.

  20. High Cryptosporidium prevalences in healthy Aymara children from the northern Bolivian Altiplano.

    PubMed

    Esteban, J G; Aguirre, C; Flores, A; Strauss, W; Angles, R; Mas-Coma, S

    1998-01-01

    The prevalence of Cryptosporidium infection was determined in four Aymara communities in the Bolivian Altiplano, between the city of La Paz and Lake Titicaca, at an altitude of 3,800-4,200 meters. Single stool specimens were randomly collected from 377 5-19-year-old students, all apparently asymptomatic. The total prevalence (31.6%) is possibly the highest reported among healthy humans (a maximum of 9.8% and 2.0% in coprologic surveys in underdeveloped and developed countries, respectively) and one of the highest even in symptomatic subjects. No significant age and sex differences were observed. Such an infection prevalence is probably related to the poor sanitation conditions, contaminated water supplies, overcrowding, and close contact with domestic animals. Continuous exposure to the parasite could be associated with protection against parasite-related symptoms in the children examined.

  1. Rapid uplift of the Altiplano revealed through 13C-18O bonds in paleosol carbonates.

    PubMed

    Ghosh, Prosenjit; Garzione, Carmala N; Eiler, John M

    2006-01-27

    The elevation of Earth's surface is among the most difficult environmental variables to reconstruct from the geological record. Here we describe an approach to paleoaltimetry based on independent and simultaneous determinations of soil temperatures and the oxygen isotope compositions of soil waters, constrained by measurements of abundances of 13C-18O bonds in soil carbonates. We use this approach to show that the Altiplano plateau in the Bolivian Andes rose at an average rate of 1.03 +/- 0.12 millimeters per year between approximately 10.3 and approximately 6.7 million years ago. This rate is consistent with the removal of dense lower crust and/or lithospheric mantle as the cause of elevation gain.

  2. A new species of Heleobia (Caenogastropoda: Cochliopidae) from the Chilean Altiplano.

    PubMed

    Collado, Gonzalo A; Valladares, Moisés A; Méndez, Marco A

    2016-01-01

    Cochliopidae Tryon, 1866 is a diverse family of caenogastropods that lives in a wide variety of aquatic habitats primarily in the New World (Hershler &Thompson 1992). In Chile, the species of the group have been traditionally assigned to the genus Littoridina Souleyet, 1852 using conchological characters (Biese 1944, 1947; Stuardo, 1961; Valdovinos 2006) but according to anatomical studies and phylogenetic analysis the majority of them have been reassigned to the genus Heleobia Stimpson, 1865 (Hershler & Thompson 1992; Collado et al. 2011a; Kroll et al. 2012; Collado et al. 2013; Collado et al. 2016). Here we formally describe a new species of the genus Heleobia from Spring 1 in the Carcote saltpan, Chilean Altiplano, based on molecular and morphological characters. Snails from this locality were previously shown to be distinct based on DNA sequences (Collado et al. 2013; Collado et al. 2016). PMID:27470721

  3. A new species of Heleobia (Caenogastropoda: Cochliopidae) from the Chilean Altiplano.

    PubMed

    Collado, Gonzalo A; Valladares, Moisés A; Méndez, Marco A

    2016-07-11

    Cochliopidae Tryon, 1866 is a diverse family of caenogastropods that lives in a wide variety of aquatic habitats primarily in the New World (Hershler &Thompson 1992). In Chile, the species of the group have been traditionally assigned to the genus Littoridina Souleyet, 1852 using conchological characters (Biese 1944, 1947; Stuardo, 1961; Valdovinos 2006) but according to anatomical studies and phylogenetic analysis the majority of them have been reassigned to the genus Heleobia Stimpson, 1865 (Hershler & Thompson 1992; Collado et al. 2011a; Kroll et al. 2012; Collado et al. 2013; Collado et al. 2016). Here we formally describe a new species of the genus Heleobia from Spring 1 in the Carcote saltpan, Chilean Altiplano, based on molecular and morphological characters. Snails from this locality were previously shown to be distinct based on DNA sequences (Collado et al. 2013; Collado et al. 2016).

  4. Constraints on plateau architecture and assembly from deep crustal xenoliths, northern Altiplano (SE Peru)

    NASA Astrophysics Data System (ADS)

    Chapman, Alan; Ducea, Mihai; McQuarrie, Nadine; Coble, Matthew; Petrescu, Lucian; Hoffman, Derek

    2016-04-01

    Newly discovered xenoliths within Pliocene and Quaternary intermediate volcanic rocks from southern Peru permit examination of lithospheric processes by which thick crust (60-70 km) and high average elevations (3-4 km) resulted within the Altiplano, the second most extensive orogenic plateau on Earth. The most common petrographic groups of xenoliths studied here are igneous or meta-igneous rocks with radiogenic isotopic ratios consistent with recent derivation from asthenospheric mantle (87Sr/ 86Sr = 0.704-0.709, 143Nd/144Nd = 0.5126-0.5129). A second group, consisting of felsic granulite xenoliths exhibiting more radiogenic compositions (87Sr/86Sr = 0.711-0.782, 143Nd/144Nd = 0.5121-0.5126), is interpreted as supracrustal rocks that underwent metamorphism at ~9 kbar (~30-35 km paleodepth, assuming a mean crustal density of 2.8 g/cm3) and ~750 °C. These rocks are correlated with nonmetamorphosed rocks of the Mitu Group and assigned a Mesozoic (Upper Triassic or younger) age based on detrital zircon U-Pb ages. A felsic granulite Sm-Nd garnet whole-rock isochron of 42 ± 2 Ma demonstrates that garnet growth took place in Eocene time. Monazite grains associated with quenched anatectic melt networks in the same rocks yield ion microprobe U-Pb ages ranging from 3.2 ± 0.2 to 4.4 ± 0.3 Ma (2σ). These disparate geochronologic data sets are reconciled by a model wherein Mesozoic cover rocks were transferred to >30 km depth beneath the plateau in the Eocene and progressively heated until at least Pliocene time. Isothermal decompression and partial melting ensued as these rocks were entrained as xenoliths in volcanic host magmas and transported toward the surface. Mafic granulites and peridotites from the same xenolith suite comprise the basement of the metasedimentary sequence, exhibiting isotopic characteristics of Central Andean crust. Calculated equilibrium pressures for these basement rocks are >11 kbar, suggesting that the basement-cover interface lies beneath the

  5. STS-55 Earth observation of Altiplano ash/dust plume in Argentina

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-55 Earth observation taken from Columbia, Orbiter Vehicle (OV) 102, shows several plumes of blowing material over northern Argentina. All plumes originate downwind of the recent volcanic eruption of Lascar Volcano (just over the border in northern Chile). It seems most likely, therefore, that the blown material is dust-sized particles of ash that was deposited on the high Andean plateau by Lascar during the eruption of 04-20-93. The large, dense, V-shaped plume in this frame is about 40 kilometers long. It is blowing eastwards from a point about 100 km southeast of Lascar. On 05-10-93, images from the AVHRR sensor on the environmental satellite NOAA-11 showed the dust from these parts of Altiplano reaching the lowlands hundreds of kilometers to the east. This photo was recorded on 05-04-93 at 19 hours 10 minutes 38 seconds GMT.

  6. PRESENCE OF MYCOBACTERIUM AVIUM SUBSP. PARATUBERCULOSIS IN ALPACAS (LAMA PACOS) INHABITING THE CHILEAN ALTIPLANO.

    PubMed

    Salgado, Miguel; Sevilla, Iker; Rios, Carolina; Crossley, Jorge; Tejeda, Carlos; Manning, Elizabeth

    2016-03-01

    Mycobacterium avium subsp. paratuberculosis (MAP) is the etiologic agent of paratuberculosis. The organism causes disease in both domestically managed and wild ruminant species. South American camelids have a long, shared history with indigenous people in the Andes. Over the last few decades, increasing numbers of alpacas were exported to numerous countries outside South America. No paratuberculosis surveillance has been reported for these source herds. In this study, individual fecal samples from 85 adult alpacas were collected from six separate herds in the Chilean Altiplano. A ParaTB mycobacterial growth indicator tube (MGIT) liquid culture of each individual fecal sample, followed by real-time polymerase chain reaction (PCR) protocol was used for confirmation. DNA extracts from a subset of confirmed MAP isolates were subjected to mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) typing. Fifteen alpaca were fecal culture test-positive. Five false-positive culture samples were negative on PCR analysis for Mycobacterium avium subsp. avium (MAA), Mycobacterium bovis (M. bovis), and the 16 S rDNA gene. Three MAP isolates subset-tested belonged to the same MIRU-VNTR type, showing four repeats for TR292 (locus 1) in contrast to the three repeats typical of the MAP reference strain K10. The number of repeats found in the remaining loci was identical to that of the K10 strain. It is not known how nor when MAP was introduced into the alpaca population in the Chilean Altiplano. The most plausible hypothesis to explain the presence of MAP in these indigenous populations is transmission by contact with infected domestic small ruminant species that may on occasion share pastures or range with alpacas. Isolation of this mycobacterial pathogen from such a remote region suggests that MAP has found its way beyond the confines of intensively managed domestic agriculture premises.

  7. An outbreak of acute fascioliasis among Aymara Indians in the Bolivian Altiplano.

    PubMed

    Bjorland, J; Bryan, R T; Strauss, W; Hillyer, G V; McAuley, J B

    1995-11-01

    Fasciola hepatica is a common and important parasite of sheep, cattle, and other ruminants. In May 1991, 30 persons with possible acute fascioliasis were identified by health care providers at a district hospital in the Bolivian Altiplano, and two deaths were associated with this illness. A cross-sectional survey of a random sample of 30 (20%) of the 148 households in the community and a case-control study were performed to determine the extent of the outbreak and the vehicle of transmission. Ninety-one members from 23 of the 30 selected families participated in the cross-sectional survey. Twenty-one of the 91 members met the case definition for acute fascioliasis (illness since 16 February 1991 that was characterized by fever and abdominal pain plus serum IgG antibodies to F. hepatica), and 38 (49%) of 78 members had serum IgG antibodies to F. hepatica. If this rate is extrapolated to the entire community, an estimated 116 individuals (23% of 504) would have acute fascioliasis and 247 individuals (49% of 504) would have evidence of current or previous infection. Case-control analysis indicated that the only factor associated with illness was eating kjosco (an aquatic plant) while tending animals in the fields; 27 (52%) of the 52 case-patients vs. 9 (14%) of the 66 controls ate kjosco (OR = 6.84; 95% CI = 2.60, 18.44). The cause of the two deaths attributed to fascioliasis could not be firmly established. Fascioliasis is a significant human health problem and is highly endemic in the Aymara Indian community in the Bolivian Altiplano. Efforts to prevent fascioliasis should include educating people to avoid eating uncooked aquatic plants such as kjosco.

  8. Dynamics of the Active Altiplano Puna Magmatic Body: Large-Scale Melt Transport and Buoyant Upwelling

    NASA Astrophysics Data System (ADS)

    Diez, M.; Del Potro, R.

    2014-12-01

    A wide range of geophysical observations suggest that an active partially molten region (Altiplano Puna Magmatic Body or APMB) lies in the mid-upper crust of the Altiplano Puna Plateau, in the Central Andes, with its upper contact at around 20 km depth. In particular, gravity, magnetotellurics and seismics have helped delineating the overall geometry of this intrusive body, which is approximately 200 km in diameter and could be many kilometers thick. The average melt fraction is poorly constrained, although it has been suggested that it could be rather high, around ~15% or higher. In addition to constraining the general shape of the APMB, its dynamics can in principle be partially accessed through geodetic measurements at the surface. In fact, recent InSAR-related studies have shown a ground deformation rate in the order of centimeter per year, with a central uplifting region, centered roughly around a lava-dome complex type of system, Uturuncu volcano, surrounded by an extensive peripheral zone of subsidence. This wealth of observations has leaded us to propose two different hypotheses to partially explain the inner workings of the APMB: (i) the dynamic deformation of the uplift-subsidence of the surface is explained by the impingement of a buoyant melt-rich blob on the more brittle upper levels of the crust, and; (ii) such surface deformation could be associated to the poroviscous compaction induced by lateral melt transport toward a central region of ascent. Both scenarios are modeled numerically. In principle the two hypotheses could explain the rate and geometry of subsidence under some simplifications. We discuss the consequences of both hypotheses, and entertain the possibility of both processes operating together.

  9. Giant magmatic water reservoir beneath Uturuncu volcano and Altiplano-Puna region (Central Andes)

    NASA Astrophysics Data System (ADS)

    Laumonier, Mickael; Gaillard, Fabrice; Muir, Duncan; Blundy, Jon; Unsworth, Martyn

    2016-04-01

    Volcanism at continental arcs is the surface manifestation of long-lived crustal magmatic processes whereby mantle-derived hydrous basalt magma differentiates to more silica-rich magmas by a combination of crystallization and crustal melting. What erupts is just a fraction of the total volume of magma produced by these processes; the unerupted, plutonic residues solidify and are inaccessible to direct study until millions of years of uplift and erosion bring them to the surface. In contrast, geophysical surveys, using electromagnetic and seismic waves, can provide real-time images of subduction zone magmatic systems. Several such studies have revealed that arc volcanoes are underlain by large partially molten regions at depths of >10 km, the largest known example being the Altiplano-Puna magma body (APMB) in central Andes. Interpreting such geophysical images in terms of amount, composition and distribution of partial melts is limited by our lack of knowledge of the physical properties of silicate melts at elevated pressures and temperatures. Here we present high-pressure, in situ experimental data showing that the electrical conductivity of andesitic melts is primarily controlled by their dissolved water contents. Linking our new measurements to petrological constraints from andesites erupted on the Altiplano, we show that the APMB is composed of 10-20% of an andesitic melt containing 8-10 wt% dissolved water. This implies that the APMB is a giant water anomaly in the global subduction system, with a total mass of dissolved magmatic water about half of the water contained within the Adriatic Sea. In addition to the controls on the physical properties of the melts, the abundance of dissolved water governs the structural levels of magma ponding, equivalent to the depth of water saturation, where degassing and crystallisation promote partial melting and weakening of the upper crust. Unexpectedly, very high concentrations of water in andesite magmas shall impede their

  10. A population-based coprological study of human fascioliasis in a hyperendemic area of the Bolivian Altiplano.

    PubMed

    Esteban, J G; Flores, A; Angles, R; Strauss, W; Aguirre, C; Mas-Coma, S

    1997-07-01

    The community of Chijipata Alta, at an altitude of 3850 m, near the southern coast of Lake Titicaca in the northern Altiplano of Bolivia, was surveyed for human fascioliasis. The global prevalence (66.7%) and intensity (eggs per gram of faeces--epg: range: 24-4440; arithmetic mean: 1001; geometric mean: 390) proved to be the highest known in the world by means of coprological techniques. These results suggest the existence of highly hyperendemic subzones among the large human fascioliasis-endemic zone of the Bolivian northern Altiplano. Despite the decrease in prevalence and intensity from children (75.0%, 24-4440 epg) to adults (41.7%, 144-864 epg), our findings show that in an hyperendemic zone adult subjects either maintain the parasites acquired when young or are newly infected as the consequence of inhabiting a zone of high infection risk.

  11. Comment on "Rapid uplift of the Altiplano revealed through 13C-18O bonds in paleosol carbonates".

    PubMed

    Sempere, T; Hartley, A; Roperch, P

    2006-11-01

    Based on stable isotope measurements, Ghosh et al. (Reports, 27 January 2006, p. 511) concluded that the Bolivian Altiplano uplifted 3 to 4 kilometers between approximately 10.3 and approximately 6.7 million years ago as a result of gravitational loss of dense lithosphere. This result stands at odds with current geological knowledge of the Central Andes, and we propose a test for the reliability of the paleoaltimetry method.

  12. Long-Term Uplift in the Altiplano-Puna Neovolcanic Zone: Evidence of an Active Magmatic Diapir?

    NASA Astrophysics Data System (ADS)

    Fialko, Y.; Pearse, J.

    2012-12-01

    We present InSAR observations of a long-term uplift in the Altiplano-Puna neovolcanic zone (central Andes, South America). Previous observations revealed a a massive Ultra Low Velocity Zone (ULVZ) at depth of 17-19 km (Zandt et al., 2003), and surface deformation that was attributed to Uturuncu, a dormant volcano in the middle of the Altiplano-Puna neovolcanic zone (Pritchard and Simons, 2002). Our time series analysis of combined data from different sensors (ERS-1/2 and ENVISAT), satellite tracks, and observation modes (fine beam and ScanSAR) reveals that the central uplift has persisted at a nearly constant rate of ~1 cm/yr over the last two decades, and is surrounded by a broad zone of subsidence. We use the satellite line-of-sight velocities from different look directions to constrain the depth and geometry of the inferred sources of magmatic unrest. Inversions based on elastic half-space models indicate that the inflation source is located well below the brittle-ductile transition, and likely resides at the depth of the seismically imaged ULVZ. We investigated the effects of inelastic deformation in the ambient crust using finite element models. The models incorporated laboratory-derived rheologies of the ambient crust, and geotherms appropriate for an active neo-volcanic zone such as the one in the Altiplano-Puna province. Based on a large number of numerical simulations constrained by the observed surface velocities, we conclude that the ongoing uplift and peripheral subsidence result from a large mid-crustal diapir fed by a partially molten source region in the middle crust. The observed pattern of surface deformation due to the Altiplano-Puna ULVZ is remarkably similar to that due to the Socorro Magma Body (SMB) in central New Mexico, USA (Pearse and Fialko, 2010), suggesting a common process. mosaic of the mean LOS velocity showing uplift and peripheral subsidence due to the inferred mid-crustal diapir.

  13. The Genetic History of Indigenous Populations of the Peruvian and Bolivian Altiplano: The Legacy of the Uros

    PubMed Central

    Sandoval, José Raul; Lacerda, Daniela R.; Jota, Marilza S. A.; Salazar-Granara, Alberto; Vieira, Pedro Paulo R.; Acosta, Oscar; Cuellar, Cinthia; Revollo, Susana; Fujita, Ricardo; Santos, Fabrício R.

    2013-01-01

    The Altiplano region of the South American Andes is marked by an inhospitable climate to which the autochthonous human populations adapted and then developed great ancient civilizations, such as the Tiwanaku culture and the Inca Empire. Since pre-Columbian times, different rulers established themselves around the Titicaca and Poopo Lakes. By the time of the arrival of Spaniards, Aymara and Quechua languages were predominant on the Altiplano under the rule of the Incas, although the occurrence of other spoken languages, such as Puquina and Uruquilla, suggests the existence of different ethnic groups in this region. In this study, we focused on the pre-Columbian history of the autochthonous Altiplano populations, particularly the Uros ethnic group, which claims to directly descend from the first settlers of the Andes, and some linguists suggest they might otherwise be related to Arawak speaking groups from the Amazon. Using phylogeographic, population structure and spatial genetic analyses of Y-chromosome and mtDNA data, we inferred the genetic relationships among Uros populations (Los Uros from Peru, Uru-Chipaya and Uru-Poopo from Bolivia), and compared their haplotype profiles with eight Aymara, nine Quechua and two Arawak (Machiguenga and Yanesha) speaking populations from Peru and Bolivia. Our results indicated that Uros populations stand out among the Altiplano populations, while appearing more closely related to the Aymara and Quechua from Lake Titicaca and surrounding regions than to the Amazon Arawaks. Moreover, the Uros populations from Peru and Bolivia are genetically differentiated from each other, indicating a high heterogeneity in this ethnic group. Finally, our results support the distinctive ancestry for the Uros populations of Peru and Bolivia, which are likely derived from ancient Andean lineages that were partially replaced during more recent farming expansion events and the establishment of complex civilizations in the Andes. PMID:24039843

  14. The genetic history of indigenous populations of the Peruvian and Bolivian Altiplano: the legacy of the Uros.

    PubMed

    Sandoval, José Raul; Lacerda, Daniela R; Jota, Marilza S A; Salazar-Granara, Alberto; Vieira, Pedro Paulo R; Acosta, Oscar; Cuellar, Cinthia; Revollo, Susana; Fujita, Ricardo; Santos, Fabrício R

    2013-01-01

    The Altiplano region of the South American Andes is marked by an inhospitable climate to which the autochthonous human populations adapted and then developed great ancient civilizations, such as the Tiwanaku culture and the Inca Empire. Since pre-Columbian times, different rulers established themselves around the Titicaca and Poopo Lakes. By the time of the arrival of Spaniards, Aymara and Quechua languages were predominant on the Altiplano under the rule of the Incas, although the occurrence of other spoken languages, such as Puquina and Uruquilla, suggests the existence of different ethnic groups in this region. In this study, we focused on the pre-Columbian history of the autochthonous Altiplano populations, particularly the Uros ethnic group, which claims to directly descend from the first settlers of the Andes, and some linguists suggest they might otherwise be related to Arawak speaking groups from the Amazon. Using phylogeographic, population structure and spatial genetic analyses of Y-chromosome and mtDNA data, we inferred the genetic relationships among Uros populations (Los Uros from Peru, Uru-Chipaya and Uru-Poopo from Bolivia), and compared their haplotype profiles with eight Aymara, nine Quechua and two Arawak (Machiguenga and Yanesha) speaking populations from Peru and Bolivia. Our results indicated that Uros populations stand out among the Altiplano populations, while appearing more closely related to the Aymara and Quechua from Lake Titicaca and surrounding regions than to the Amazon Arawaks. Moreover, the Uros populations from Peru and Bolivia are genetically differentiated from each other, indicating a high heterogeneity in this ethnic group. Finally, our results support the distinctive ancestry for the Uros populations of Peru and Bolivia, which are likely derived from ancient Andean lineages that were partially replaced during more recent farming expansion events and the establishment of complex civilizations in the Andes.

  15. The quinoa boom of the southern Bolivian Altiplano - linking geomorphology, erosion and spatial production patterns

    NASA Astrophysics Data System (ADS)

    Sander, Lasse; Jacobsen, Sven-Erik

    2014-05-01

    Quinoa (Chenopodium quinoa Willd.) is a native Andean crop that gained worldwide popularity over the last few decades due to its outstanding nutritional properties. The plant is characterized by an exceptional adaptation and is able to produce decent yields despite harsh environmental conditions like drought, frost, or soil salinity. Quinoa is thus an exceptional income opportunity in the arid southern Bolivian Altiplano, an area endemically struck by rural poverty and malnutrition. In the early 1970s, the Bolivian government introduced the first tractors to southern Bolivia's Salar region with the intention to push agricultural development - with obvious success. The cultivation of quinoa is today the most important land use, with a continued increase in production volume and areal extent. We here trace back land-use changes from 1972 to 2013 in one of the most important areas of quinoa production. Using Landsat images, SRTM elevations and field survey data, we investigate the relationship of field areas to erosion patterns and large-scale geomorphology. The soils of the southern Bolivian Altiplano are highly susceptible to particle entrainment due to a loose and sandy substrate, strong winds, and rapid drainage during precipitation and snow melt events. It appears that many of the first quinoa fields were established on flood plain deposits, where good yields could be anticipated despite the apparent risk of erosion. The subsequent expansion of production areas was paralleled by an increase in field density. Locally, this implied a reduction of fallowing length and the incorporation of marginal lands. The almost complete removal of natural (i.e. protecting) vegetation over large and continuous areas, results in increased wind erosion and partial crop failure. While production extended by approx. 1,6 % per year between 1985 and 2003, an average annual increase of 8,4 % could be observed for the last decade, when many new fields were established at lower elevations

  16. Multi-century lake area changes in the Southern Altiplano: a tree-ring-based reconstruction

    NASA Astrophysics Data System (ADS)

    Morales, M. S.; Carilla, J.; Grau, H. R.; Villalba, R.

    2015-09-01

    Size fluctuations in endorheic lakes in northwestern Argentina (NWA) and southwestern Bolivia (SWB) are very sensitive to basin hydrological balances, and consequently, very vulnerable to deleterious effects from climatic changes. The management of these water resources and their biodiversity requires a comprehensive knowledge of their natural variability over multiple timescales. In this study, we present a multi-century reconstruction of past lake-area fluctuations in NWA and SWB. The evidence used to develop and validate this reconstruction includes satellite images and a century-long tree-ring record from P. tarapacana. Inter-annual fluctuations in lake area of nine lakes were quantified based on Landsat satellite images over the period 1975 to 2009. A regional P. tarapacana tree-ring chronology, composite from two sampling sites, was used as predictors in a regression model to reconstruct the mean annual (January-December) lake area from the nine lakes. The reconstruction model captures 62 % of the total variance in lake-area fluctuations and shows adequate levels of cross-validation. This high-resolution reconstruction covers the past 601 years and characterizes the occurrence of annual to multi-decadal lake area fluctuations and its main oscillation modes of variability. Our reconstruction points out that the late 20th century decrease in lake area was exceptional over the period 1407-2007; a persistent negative trend in lake area is clear in the reconstruction and consistent with glacier retreat and other climate proxies from the Altiplano and the tropical Andes. Since the mid 1970s, the Vilama-Coruto lake system recorded an accelerated decrease in area consistent with an increasing recurrence of extremely small lake-area events. Throughout the 601 years, the reconstruction provides valuable information about spatial and temporal stabilities of the relationships between changes in lake area, ENSO, and PDO, highlighting the Pacific influence over most modes

  17. Stratigraphic signatures of crustal shortening and central Andean geodynamics in the Altiplano plateau, southern Peru

    NASA Astrophysics Data System (ADS)

    Perez, Nicholas D.; Horton, Brian K.

    2014-05-01

    The initiation and evolution of hinterland basins along convergent margins has been variably attributed to partitioning of pre-existing flexural foreland basins, drainage closure by uplift of flanking topographic barriers, and/or isolated strike-slip or extensional processes. In the central Andean plateau, the upper Oligocene to middle Miocene basin fill of the northernmost Altiplano in southern Peru preserves a record of orogenesis between the Western Cordillera magmatic arc and the Eastern Cordillera fold-thrust belt. New stratigraphic, provenance, geochronologic and structural datasets from the ~3.7-km-high Ayaviri hinterland basin suggest that upper-crustal shortening was the dominant factor controlling basin evolution. The basin preserves a ~2300 m thick succession (Puno Group and Lower Tinajani Formation) of fluvial sandstone and overbank siltstone capped abruptly by ~400 m of alluvial fan pebble-boulder conglomerate (Upper Tinajani Formation). New U-Pb zircon geochronologic constraints from 8 tuff horizons and the youngest age populations from 10 sandstone horizons constrain the depositional age between 29.6 ± 1.2 Ma and 15.71 ± 0.97 Ma. The resulting ~15 Myr basin record yields sediment accumulation rates between 110 and 660 m/Myr, comparable to those of major lowland foreland basins. A prominent shift in basin provenance is recorded by detrital zircon U-Pb spectra, conglomerate clast compositions, modal sandstone compositions and paleocurrent data. Newly dated growth strata along the two basin-bounding thrust faults highlight the role of Andean shortening on basin evolution. Footwall growth strata along the southwest-directed Ayaviri fault defining the Eastern Cordillera margin suggests deformation at ~28 Ma. Younger footwall growth strata along the northeast-directed Pasani fault defining the Western Cordillera margin demonstrate an episode of out-of-sequence thrusting at ~16.4 Ma. This event is associated with the provenance and depositional shift of

  18. Les torsions sur testicules cryptorchides

    PubMed Central

    Gharbi, Mohamed; Amri, Najmeddine; Chambeh, Wahib; Braiek, Salem; Kamel, Rafik El

    2010-01-01

    Résumé But : La cryptorchidie est une pathologie assez fréquente en urologie. Elle est associée à un risque élevé d’infertilité et de dégénérescence. Elle semble aussi être associée à un risque important de torsion. Cette entité est très peu abordée dans la littérature. Nous rapportons tous les cas de torsion sur testicule cryptorchide observés à notre service dans le but de mieux caractériser cette pathologie et de réduire ainsi le taux d’orchidectomies. Méthodologie : Il s’agit d’une étude rétrospective portant sur tous les cas de torsion sur testicule cryptorchide opérés dans notre service d’urologie entre 1999 et 2007. Les patients ont fait l’objet d’une description basée sur le résumé de leurs observations. Résultats : Les patients étaient âgés de 7 mois à 39 ans. La torsion touchait le testicule droit dans 53 % des cas. Le tableau clinique comportait une douleur au niveau de la région inguinale d’apparition soudaine avec une masse sous-cutanée inflammatoire et douloureuse à ce niveau et surtout un hémiscrotum homolatéral vide. Dans 60 % des cas, le diagnostic était tardif et une orchidectomie a été réalisée. Dans les autre cas, un abaissement du testicule a été réalisé avec orchidopexie controlatéral dans le même temps opératoire. Conclusion : Bien qu’il s’agisse d’une pathologie peu courante, la torsion sur testicule cryptorchide doit être étudiée davantage. Le diagnostic précoce permettra de sauver et d’abaisser le testicule et faciliter ainsi le dépistage d’une éventuelle dégénérescence. PMID:21191497

  19. Anaerobic co-digestion of aquatic flora and quinoa with manures from Bolivian Altiplano.

    PubMed

    Alvarez, René; Lidén, Gunnar

    2008-01-01

    Quinoa stalk (Chenopodium quinoa Willd.) from agricultural crop residue, totora (Schoenoplectus tatora) and o-macrophytes (aquatic flora) from Lake Titicaca (on the Bolivian Altiplano) were studied in a wet anaerobic co-digestion process together with manure from llama, cow and sheep. Anaerobic semi-continuous experiments were performed in (10) 2-l reactors at a temperature of 25 degrees C with 30 days of hydraulic retention time (HRT) and an organic loading rate (OLR) of 1.8 kg VS m(-3) d(-1). Totora was found to be the best co-substrate. In mixture ratios of 1:1 (VS basis), it increased the biogas productivity by 130% for llama manure, 60% for cow manure, and 40% for sheep manure. It was possible to use up to 58% (VS basis) of totora in the substrate. Higher concentrations (including pure totora) could not be digested, as that caused acidification problems similar to those caused by other lignocellulosic materials. When quinoa and o-macrophytes were used as co-substrates, the increase in biogas productivity was slightly less. However, these co-substrates did not cause any operational problems. An additional advantage of quinoa and o-macrophytes was that they could be used in any proportion (even in pure form) without causing any destabilization problems in the anaerobic digestion process.

  20. Hair trace elements concentration to describe polymetallic mining waste exposure in Bolivian Altiplano.

    PubMed

    Barbieri, Flavia Laura; Cournil, Amandine; Souza Sarkis, Jorge Eduardo; Bénéfice, Eric; Gardon, Jacques

    2011-01-01

    Severe polymetallic contamination is frequently observed in the mining communities of Bolivian Altiplano. We evaluated hair trace elements concentrations at the population level to characterise exposure profile in different contexts of contact with mining and metallurgical pollution. We sampled 242 children aged 7 to 12 years in schools from five Oruro districts located in different contexts of potential contamination. Hair trace elements concentrations were measured using ICP-MS (Pb, As, Hg, Cd, Sb, Sn, Bi, Ag, Ni, Se, Cu, Cr, Mn, Co and Zn). We compared concentration according to school areas and gender. Concentrations were markedly different depending on school areas. Children from schools near industrial areas were far more exposed to non essential elements than children from downtown and suburban schools, as well as the rural school. The most concentrated non-essential element was Pb (geometric means (SD): 1.6 (1.3) µg/g in rural school; 2.0 (2.3) µg/g in suburban school; 2.3 (3.0) µg/g in downtown school; 14.1 (2.7) µg/g in the mine school and 21.2 (3.3) µg/g in the smelter school). Boys showed higher levels for all non-essential elements while girls had higher levels of Zn. Hair trace elements concentrations highlighted the heterogeneity of exposure profiles, identifying the most contaminated districts.

  1. Unique clusters of Archaea in Salar de Huasco, an athalassohaline evaporitic basin of the Chilean Altiplano.

    PubMed

    Dorador, Cristina; Vila, Irma; Remonsellez, Francisco; Imhoff, Johannes F; Witzel, Karl-Paul

    2010-08-01

    Analyses of clone libraries from water and sediments of different sites from Salar de Huasco, a high-altitude athalassohaline wetland in the Chilean Altiplano, revealed the presence of five unique clusters of uncultured Archaea that have not been previously reported or specifically assigned. These sequences were distantly related (83-96% sequence identity) to a limited number of other clone sequences and revealed no identity to cultured Archaea. The abundance of Archaea and Bacteria was estimated using qPCR and community composition was examined through the construction of clone libraries of archaeal 16S rRNA gene. Archaea were found to be dominant over Bacteria in sediments from two saline sites (sites H4: 6.31 x 10(4) and site H6: 1.37 x 10(4) microS cm(-1)) and in one of the water samples (freshwater from site H0: 607 muS cm(-1)). Euryarchaeotal sequences were more abundant than crenarchaeotal sequences. Many of the clone sequences (52%) were similar to uncultured archaeal groups found in marine ecosystems having identity values between 99% and 97%. A major fraction of the sequences (40%) were members of Methanobacteria, while others were included in the Marine Benthic Groups B and D, the Miscellaneous Crenarchaeotic Group, the Terrestrial Miscellaneous Euryarchaeotal Group, Marine Group I and Halobacteria. The presence of uncultured archaeal groups in Salar de Huasco extends their known distribution in inland waters, providing new clues about their possible function in the environment.

  2. The Northern Bolivian Altiplano: a region highly endemic for human fascioliasis.

    PubMed

    Mas-Coma, S; Anglés, R; Esteban, J G; Bargues, M D; Buchon, P; Franken, M; Strauss, W

    1999-06-01

    The worldwide importance of human infection by Fasciola hepatica has been recognized in recent years. The endemic region between Lake Titicaca and the valley of La Paz, Bolivia, at 3800-4100 m altitude, presents the highest prevalences and intensities recorded. Large geographical studies involving Lymnaea truncatula snails (malacological, physico-chemical, and botanic studies of 59, 28 and 30 water bodies, respectively, inhabited by lymnaeids; environmental mean temperature studies covering a 40-year period), livestock (5491 cattle) and human coprological surveys (2723 subjects, 2521 of whom were school children) were conducted during 1991-97 to establish the boundaries and distributional characteristics of this endemic Northern Altiplano region. The endemic area covers part of the Los Andes, Ingavi, Omasuyos and Murillo provinces of the La Paz Department. The human endemic zone is stable, isolated and apparently fixed in its present outline, the boundaries being marked by geographical, climatic and soil-water chemical characteristics. The parasite distribution is irregular in the endemic area, the transmission foci being patchily distributed and linked to the presence of appropriate water bodies. Prevalences in school children are related to snail population distribution and extent. Altiplanic lymnaeids mainly inhabit permanent water bodies, which enables parasite transmission during the whole year. A confluence of several factors mitigates the negative effects of the high altitude.

  3. Anaerobic co-digestion of aquatic flora and quinoa with manures from Bolivian Altiplano

    SciTech Connect

    Alvarez, Rene Liden, Gunnar

    2008-07-01

    Quinoa stalk (Chenopodium quinoa Willd.) from agricultural crop residue, totora (Schoenoplectus tatora) and o-macrophytes (aquatic flora) from Lake Titicaca (on the Bolivian Altiplano) were studied in a wet anaerobic co-digestion process together with manure from llama, cow and sheep. Anaerobic semi-continuous experiments were performed in (10) 2-l reactors at a temperature of 25 deg. C with 30 days of hydraulic retention time (HRT) and an organic loading rate (OLR) of 1.8 kg VS m{sup -3} d{sup -1}. Totora was found to be the best co-substrate. In mixture ratios of 1:1 (VS basis), it increased the biogas productivity by 130% for llama manure, 60% for cow manure, and 40% for sheep manure. It was possible to use up to 58% (VS basis) of totora in the substrate. Higher concentrations (including pure totora) could not be digested, as that caused acidification problems similar to those caused by other lignocellulosic materials. When quinoa and o-macrophytes were used as co-substrates, the increase in biogas productivity was slightly less. However, these co-substrates did not cause any operational problems. An additional advantage of quinoa and o-macrophytes was that they could be used in any proportion (even in pure form) without causing any destabilization problems in the anaerobic digestion process.

  4. Climatic and tectonic implications of the late Miocene Jakokkota flora, Bolivian Altiplano

    NASA Astrophysics Data System (ADS)

    Gregory-Wodzicki, Kathryn M.; McIntosh, W. C.; Velasquez, Kattia

    1998-12-01

    When compared to a database of modern foliar physiognomy and climate, the physiognomy of a new collection of dicotyledonous leaves from the 10.66±0.06 Ma Jakokkota flora, Bolivian Altiplano, implies a mean annual temperature (MAT) of 18.6-21.0±2.5°C. Similarly, a literature-derived sample of the early-middle Miocene Potosı´flora, Cordillera Oriental, implies a MAT of 21.5-21.7±2.1°C. We estimate that both floras experienced a growing season precipitation of 50±40 cm. The paleoclimate thus appears considerably warmer than the current highland climate, with MATs of 8-9°C; the paleoprecipitation is indistinguishable from modern levels. A comparison of the Miocene MATs with the modern MATs, with the effects of latitudinal continental drift and global climate change subtracted, suggests that the Jakokkota flora grew at an elevation of 590-1610±1000 m, and the Potosı´flora grew at an elevation of 0-1320±1000 m. Both paleoelevation estimates are significantly lower than the present elevations of 3940 and 4300 m, respectively, requiring a substantial component of Andean uplift since 10.7 Ma. This uplift history is consistent with two-stage tectonic models of Andean orogeny.

  5. Anaerobic co-digestion of aquatic flora and quinoa with manures from Bolivian Altiplano.

    PubMed

    Alvarez, René; Lidén, Gunnar

    2008-01-01

    Quinoa stalk (Chenopodium quinoa Willd.) from agricultural crop residue, totora (Schoenoplectus tatora) and o-macrophytes (aquatic flora) from Lake Titicaca (on the Bolivian Altiplano) were studied in a wet anaerobic co-digestion process together with manure from llama, cow and sheep. Anaerobic semi-continuous experiments were performed in (10) 2-l reactors at a temperature of 25 degrees C with 30 days of hydraulic retention time (HRT) and an organic loading rate (OLR) of 1.8 kg VS m(-3) d(-1). Totora was found to be the best co-substrate. In mixture ratios of 1:1 (VS basis), it increased the biogas productivity by 130% for llama manure, 60% for cow manure, and 40% for sheep manure. It was possible to use up to 58% (VS basis) of totora in the substrate. Higher concentrations (including pure totora) could not be digested, as that caused acidification problems similar to those caused by other lignocellulosic materials. When quinoa and o-macrophytes were used as co-substrates, the increase in biogas productivity was slightly less. However, these co-substrates did not cause any operational problems. An additional advantage of quinoa and o-macrophytes was that they could be used in any proportion (even in pure form) without causing any destabilization problems in the anaerobic digestion process. PMID:18155895

  6. Presence of very high prevalence and intensity of infection with Fasciola hepatica among Aymara children from the Northern Bolivian Altiplano.

    PubMed

    Esteban, J G; Flores, A; Aguirre, C; Strauss, W; Angles, R; Mas-Coma, S

    1997-06-24

    Coprological studies of school children from four communities in the Northern Bolivian Altiplano were carried out in order to estimate the prevalences and intensities of Fasciola hepatica infection. Single stool specimens were collected at random from 558 school children (308 boys and 250 girls) aged 5-19 years old. Nineteen different parasite species (13 protozoan and six helminths) were detected. Of the children examined, 98.7% (96.5-100%) presented infection with at least one parasite species. The mean prevalence of 27.6% by Fasciola hepatica (range, 5.9-38.2%) was the highest not only with respect to the helminth species found in the Northern Bolivian Altiplano but also among the fasciolosis prevalences reported in children in other parts of the world to date. Prevalences were significantly different among the communities surveyed and was significantly higher in the 9-12 years age group. There were, however, no significant differences between sexes. Among the 154 children presenting F. hepatica eggs in stools, intensities ranged from 24-5064 eggs per gram of faeces (epg), with arithmetic and geometric means of 474 and 201 epg, respectively. Significant differences in mean egg output were detected between communities, sexes and age groups. Individual fasciolosis infections coexisting with other pathogenic parasite species (Entamoeba histolytica and/or E. dispar, Giardia intestinalis, Balantidium coli, Dientamoeba fragilis, Cryptosporidium sp., Hymenolepis nana, Taenia spp., Trichuris trichiura, Ascaris lumbricoides and Enterobius vermicularis) were detected. A significant positive association with F. hepatica was only found in the case of G. intestinalis. This coprological study not only verifies the existence of high prevalences of F. hepatica among humans in the Northern Bolivian Altiplano, but also demonstrates the need to expand the Southern boundaries of this high endemic zone to include the Southeastern region of Lake Titicaca.

  7. Presence of very high prevalence and intensity of infection with Fasciola hepatica among Aymara children from the Northern Bolivian Altiplano.

    PubMed

    Esteban, J G; Flores, A; Aguirre, C; Strauss, W; Angles, R; Mas-Coma, S

    1997-06-24

    Coprological studies of school children from four communities in the Northern Bolivian Altiplano were carried out in order to estimate the prevalences and intensities of Fasciola hepatica infection. Single stool specimens were collected at random from 558 school children (308 boys and 250 girls) aged 5-19 years old. Nineteen different parasite species (13 protozoan and six helminths) were detected. Of the children examined, 98.7% (96.5-100%) presented infection with at least one parasite species. The mean prevalence of 27.6% by Fasciola hepatica (range, 5.9-38.2%) was the highest not only with respect to the helminth species found in the Northern Bolivian Altiplano but also among the fasciolosis prevalences reported in children in other parts of the world to date. Prevalences were significantly different among the communities surveyed and was significantly higher in the 9-12 years age group. There were, however, no significant differences between sexes. Among the 154 children presenting F. hepatica eggs in stools, intensities ranged from 24-5064 eggs per gram of faeces (epg), with arithmetic and geometric means of 474 and 201 epg, respectively. Significant differences in mean egg output were detected between communities, sexes and age groups. Individual fasciolosis infections coexisting with other pathogenic parasite species (Entamoeba histolytica and/or E. dispar, Giardia intestinalis, Balantidium coli, Dientamoeba fragilis, Cryptosporidium sp., Hymenolepis nana, Taenia spp., Trichuris trichiura, Ascaris lumbricoides and Enterobius vermicularis) were detected. A significant positive association with F. hepatica was only found in the case of G. intestinalis. This coprological study not only verifies the existence of high prevalences of F. hepatica among humans in the Northern Bolivian Altiplano, but also demonstrates the need to expand the Southern boundaries of this high endemic zone to include the Southeastern region of Lake Titicaca. PMID:9177091

  8. Two new species of Litomosoides (Nemata:Onchocercidae) from Ctenomys opimus (Rodentia:Ctenomyidae) on the altiplano of Bolivia.

    PubMed

    Brant, S V; Gardner, S L

    1997-08-01

    Two filarioid nematodes, Litomosoides andersoni n. sp. and Litomosoides ctenomyos n. sp. (Nemata: Onchocercidae), are described from the mesenteries of the subterranean rodent Ctenomys opimus (Rodentia: Hystrichognathi) collected on the altiplano of Bolivia. Specimens collected near Rancho Huancaroma (Oruro Dept.) in 1984 and 1986 can be recognized as undescribed by the structures of the spicules and stoma and the shape of the ovijector. This record represents the first time members of the genus Litomosoides have been recovered from rodents of the family Ctenomyidae; this also represents the first published report of these nematodes from mammals in Bolivia.

  9. Deciphering the Spatial and Temporal Nature of the Surface Uplift in the Altiplano Plateau

    NASA Astrophysics Data System (ADS)

    Kar, N.; Garzione, C. N.; Carlotto, V. S.; Smith, S.; Pullen, A. T.; Shanahan, T. M.; Anderson, V. J.; Eiler, J. M.

    2014-12-01

    The surface uplift history of the Altiplano plateau is widely debated. Two end-member models favor: a slow and gradual surface uplift from ~45Ma by distributed shortening; and pulsed rapid surface uplift between 16-9 Ma and 10-6 Ma in the southern and central plateau respectively by lower lithospheric removal. To better elucidate the along strike nature of the surface uplift, we extended the elevation and deformation history to the early to late Cenozoic basins in the northernmost part of the Central Andean plateau, inferred to have formed in the foreland, wedgetop, and hinterland settings of the Andean fold-thrust belt in southern Peru. Increasing deformation related to propagation of the foreland basin system is shown by early Paleocene backbulge Quilque to the late Eocene wedgetop Soncco formations. The lowest elevation (sea level) is recorded by marginal marine deposits of Quilque. The ð18O of meteoric water (ð18Omw) reconstructed from sedimentary carbonates show similar average values with -6.7 ±1.9‰ in late Paleocene Chilca to -8.1 ±2.6‰ in middle Miocene Paruro formations, suggesting a middle Miocene paleoelevation of 1.1 ±1.0 km (2σ) in first order approximation. In members A, B and C of Miocene-Pliocene Descanso Yauri basin, A and B are deformed and C is relatively undeformed and flat lying. A, B and the lower C deposits are fluvial and middle-upper C deposits are lacustrine. The ð18Omw from B and C carbonates show averages of -8.4 ±1.1‰ and -9.7 ±3.1‰; the large range in C (-5.5‰ to -14.7‰) is tentatively interpreted as a result of high altitude precipitation, modified by evaporative enrichment within the lake system. Reconstructed MAAT from Δ47 of carbonates and ðD of plant waxes show similar results in B (29.1±5.0°C, -146.6±10.9‰) and ~9Ma lower C (23.1 ±1.9°C, -149.6±9.7‰), and a large shift in ðD to -206.7±13.0‰ in upper diatomaceous non-calcareous C (minimum U-Pb zircon age constraint of 4.3 ±0.3 Ma, 2

  10. Prokaryotic diversity pattern in high-altitude ecosystems of the Chilean Altiplano

    NASA Astrophysics Data System (ADS)

    Demergasso, Cecilia; Dorador, Cristina; Meneses, Daniela; Blamey, Jenny; Cabrol, Nathalie; Escudero, Lorena; Chong, Guillermo

    2010-06-01

    The Chilean Altiplano is the westernmost part of a large volcanic-sedimentary plateau in the central Andes. High solar irradiance and rapid increase of temperature have contributed to make it a hot spot of global climatic change. In this study, we describe microbial diversity in the summit lake of the Simba volcano (5,870 m) and the evaporitic basins of Salar de Aguas Calientes (4,200 m) and Laguna Lejía (4,325 m) using both culture and culture-independent methods. The results obtained were analyzed together with available information from related environments to describe the traits of the microbial community driven by main environmental factors. Isolated cultures exhibit high resistance to all three types of UV radiation, further supporting the adaptation of microorganisms to the high altitude environment. The microbial community structures at Salar de Aguas Calientes and Laguna Lejía are similar to those from other saline systems and cold environments where Bacteroidetes is the major bacterial group. The abundance of sequences related to alphaproteobacteria and methanogenic populations likely reflects the importance of aerobic anoxigenic phothosynthesis and the cycling of one-carbon compounds in the high altitude lake ecosystems. Geochemistry and microbial communities at Simba as well as those reported in the Licancabur summit lake provide evidence for sulfur-rich environments but under different conditions. Those differences between neighboring mountain lake ecosystems highlight the effect of volcanic activity on microbial communities. The hypothetical ecosystem model described in this work provides a clue to follow the microbial community responses to geophysical environment coupled with rapid climate change.

  11. Magma intrusion and accumulation in the southern Altiplano: Structural observations from the PLUTONS project

    NASA Astrophysics Data System (ADS)

    West, M. E.; Christensen, D. H.; Pritchard, M. E.; Del Potro, R.; Gottsmann, J.; Unsworth, M.; Minaya, E.; Sunagua, M.; McNutt, S. R.; Yu, Q.; Farrell, A. K.

    2012-12-01

    The PLUTONS project is attempting to capture the process of magma intrusion and pluton formation, in situ, through multi-disciplinary study of known magmatic inflation centers. With support from the NSF Continental Dynamics program, and a sister project in the UK funded by NERC, two such centers are receiving focused study. Uturuncu volcano in the Altiplano of southern Bolivia is being investigated with combined seismics, magnetotellurics, geodesy, microgravity, geomorphology, petrology, geochemistry, historical studies and modeling. 350 km to the south, comparable investigations are targeting the Lastarria-Cordon del Azufre complex. Field studies are ongoing into 2013. In this presentation we highlight results from Uturuncu that bear on the crustal magmatic process. Seismic tomography, gravity and magnetotellurics indicate a complex structure in the upper 20 km with some evidence for partial melt. Seismic receiver functions indicate a layer of very low velocities across the region at 15-25 km depth that is almost certainly melt-rich. High conductivities corroborate the interpretation of a partial melt component to this layer. In addition to the throughgoing melt layer, seismic velocities and attenuation indicate shallow features above the melt body extending upward toward the surface. It is not clear whether these features are associated with recent uplift or are remnants from a previous period of activity. Uturuncu is seismically active with hundreds of locatable earthquakes each year. Seismic lineations and swarm behavior suggest that the seismicity reflects regional stress patterns. While there is little evidence that these earthquakes are the direct result of magmatic intrusion, the resulting high heat flow may be hastening existing strains.

  12. Molecular characterization and antibiotic resistance of Enterococcus species from gut microbiota of Chilean Altiplano camelids

    PubMed Central

    Guerrero-Olmos, Katheryne; Báez, John; Valenzuela, Nicomédes; Gahona, Joselyne; del Campo, Rosa; Silva, Juan

    2014-01-01

    Background Enterococcus is one of the major human pathogens able to acquire multiple antibiotic-resistant markers as well as virulence factors which also colonize remote ecosystems, including wild animals. In this work, we characterized the Enterococcus population colonizing the gut of Chilean Altiplano camelids without foreign human contact. Material and methods Rectal swabs from 40 llamas and 10 alpacas were seeded in M-Enterococcus agar, and we selected a total of 57 isolates. Species identification was performed by biochemical classical tests, semi-automated WIDER system, mass spectrometry analysis by MALDI-TOF (matrix-assisted laser desorption/ionization with a time-of-flight mass spectrometer), and, finally, nucleotide sequence of internal fragments of the 16S rRNA, rpoB, pheS, and aac(6)-I genes. Genetic diversity was measured by pulsed field gel electrophoresis (PFGE)-SmaI, whereas the antibiotic susceptibility was determined by the WIDER system. Carriage of virulence factors was explored by polymerase chain reaction (PCR). Results Our results demonstrated that the most prevalent specie was Enterococcus hirae (82%), followed by other non–Enterococcus faecalis and non–Enterococcus faecium species. Some discrepancies were detected among the identification methods used, and the most reliable were the rpoB, pheS, and aac(6)-I nucleotide sequencing. Selected isolates exhibited susceptibility to almost all studied antibiotics, and virulence factors were not detected by PCR. Finally, some predominant clones were characterized by PFGE into a diverse genetic background. Conclusion Enterococcus species from the Chilean camelids’ gut microbiota were different from those adapted to humans, and they remained free of antibiotic resistance mechanisms as well as virulence factors. PMID:25405007

  13. A glassy lava flow from Toconce volcano and its relation with the Altiplano-Puna Magma Body in Central Andes

    NASA Astrophysics Data System (ADS)

    Godoy, B.; Rodriguez, I.; Aguilera, F.

    2012-12-01

    Toconce is a composite stratovolcano located at the San Pedro - Linzor volcanic chain (SPLVC). This volcanic chain distributes within the Altiplano-Puna region (Central Andes) which is characterized by extensive rhyodacitic-to-rhyolitic ignimbritic fields, and voluminous domes of dacitic-to-rhyolitic composition (de Silva, 1989). The felsic melts that gave origin to ignimbrites and domes at this area were generated by mixing of mantle-derived magmas and anatectic melts assimilated during their ascent through the thick crust. Thus, partially molten layers exist in the upper crust below the APVC (de Silva et al., 2006). Evidence of large volumes of such melts has been also proposed by geophysical methods (i.e. the Altiplano-Puna Magma Body; Chmielowsky et al., 1999) In this work, petrography and whole rock, mineralogical and melt inclusions geochemistry of a glassy lava flow of Toconce volcano are presented. Petrographically, this lava flow shows a porphyric texture, with euhdral to subhedral plagioclase, ortho- and clino-pyroxene phenocrysts immersed in a glassy groundmass. Geochemically, the lava flow has 64.7% wt. SiO2. The glassy groundmass (~70% wt. SiO2) is more felsic than all the lavas in the volcanic chain (47-68% wt., Godoy et al., 2011). Analyzed orthopyroxene-hosted melt inclusions show an even higher SiO2 content (72-75% wt.), and a decreasing on Al2O3, Na2O, and CaO content with differentiation. Crystallization pressures of this lava flow, obtained using Putirka's two-pyroxene and clinopyroxene-liquid models (Putirka, 2008), range between 6 and 9 kbar. According to crystallization pressures, and major element composition, a felsic source located at shallow crustal pressures - where plagioclase is a stable mineralogical phase - originated the inclusions. This could be related to the presence of the Altiplano-Puna Magma Body (APMB) located below SPLVC. On the other hand, glassy groundmass, and disequilibrium textures in minerals of this lava flow could

  14. A new tectonic model for the development of the Eastern Cordillera, Altiplano, and Subandean zones, Bolivian Central Andes, 20[degrees]S latitude

    SciTech Connect

    Gubbels, T.L.; Isacks, B.L. ); Koch, R.W. )

    1993-02-01

    Construction of a regional transect across the central Andes at 20[degrees]S sheds new light on the relationship between the Altiplano, Eastern Cordillera (EC), and Subandean zones and allows us to refine the two-stage model of Isacks (1988) for the growth of the Central Andes. This new model is based on examination of the regional geology and geophysics, coupled with field investigations, satellite image analysis, and new Ar-Ar geochronology. In this model, widespread Oligocene to mid-Miocene compressional deformation in the Altiplano and EC was followed in the late-Miocene and Pliocene by thrusting localized east of the EC within the Subandean fold-thrust belt. During the first stage of deformation, the Altiplano basin underwent important subsidence and internal deformation. The EC was both deformed internally and thrust westwards over the Altiplano basin, while the present Subandean zone was the site of an early, broad foreland basin which received material eroded from the EC. During the second stage, beginning at [approximately]10 ma, deformation terminated within the EC and became concentrated within the fold-thrust belt in response to large scale overthrusting of the EC above the Brazilian shield; this resulted in major thrusting along the Cabalgamiento Frontal Principal (CFP), which soles into the master Subandean decollement, and [approximately]100 km of telescoping within the early, broad foreland basin. In the EC, this second stage is marked by the elaboration of a regionally extensive erosion surface, ponding of gravels in shallow basins, and the emplacement of giant ignimbrite sheets. The Eastern Cordillera can thus be thought of as a crustal-scale wedge which has been extruded upward and outward on alternate sides during successive stages of late Cenozoic deformation. This motion has served to drive subsidence in both the Altiplano and Subandean foreland basins, as well as shortening in the fold-thrust belt.

  15. Melt production constrained by the topographic signature of the Altiplano-Puna Magma Body

    NASA Astrophysics Data System (ADS)

    Perkins, J. P.; Ward, K. M.; de Silva, S. L.; Zandt, G.; Beck, S. L.; Finnegan, N. J.

    2015-12-01

    The Altiplano-Puna Magma Body (APMB) is a ~200 km diameter, ~10 km thick elliptical zone of low seismic shear velocity interpreted as partial melt within the mid crust of the Central Andes (Ward et al., 2014). It is thought to be the crustal magmatic source for a flare-up of large-volume ignimbrites since 10 Ma (e.g. de Silva et al., 1989), and recent rapid uplift events such as those at Uturuncu volcano appear to be associated with magmatism from the APMB at depth (e.g., Fialko and Pearse, 2011). Hence, the APMB is a first-order geologic feature on par with the Sierra Nevada batholith in CA. Here we use the topographic signature of the low-density APMB in order to quantitatively constrain the melt production necessary to generate a magmatic zone of this size. A long-wavelength, ~1 km high topographic dome spatially coincides with the seismically measured extent of the APMB. The peak of the long wavelength dome acts as a regional drainage divide, and exposed basement rock elevations show that doming is a structural feature and does not reflect solely the accumulation of volcanic deposits on the plateau. Additionally, the minimal free-air gravity anomaly above the APMB and the dome's length scale suggest that the uplift is isostatically compensated. Based on a buried load isostatic model (e.g., Forsyth, 1985), the dome above the APMB implies that 5.6-5.8 km of crustal thickening occurred during the emplacement of the magma body. Our estimate compares well with calculations of crustal addition using magma chamber volume and a standard melt mixing model (Ward et al., 2014), and suggests that the magma production rate for the APMB may be within the range of 70-117 km3/km/yr, similar to rates of the Late Cretaceous magmatic episode in the Sierra Nevada Batholith (e.g., Ducea, 2001). Surface topography may therefore be able to provide quantitative constraints on the magnitude of pluton-scale melt fluxes.

  16. Investigating crustal contamination: a case study from the Bolivian Altiplano, Central Andes

    NASA Astrophysics Data System (ADS)

    McLeod, C. L.; Davidson, J. P.; Nowell, G.

    2010-12-01

    Claire McLeod*, Jon Davidson, Geoff Nowell 1 1 NCIET, Department of Earth Sciences, Durham University, Science Labs, Durham, DH1 3LE, UK. * Corresponding Author: c.l.mcleod@dur.ac.uk During ascent towards the earth’s surface primary basaltic magma sourced from the mantle has the potential to interact with overlying crustal rocks. This leads to overprinting of source characteristics. Quantifying the mechanisms and timescales of crustal assimilation by differentiating magmas is key to improving our understanding of mantle source geochemistry. It is widely accepted that eruptives at continental arcs e.g. the Andes are the products of fractional crystallisation combined with intra crustal assimilation (e.g. Davidson et al., 2005). However, direct evidence of this interaction between mantle magmas and crustal rocks and the nature of potential crustal contaminants is rarely preserved. This is largely due to homogenisation and recrystallisation of mantle melts in shallow upper crustal magma chambers. On the Bolivian Altiplano to the east of the active Andean volcanic arc, monogenetic volcanic centres have erupted plagioclase-hornblende phyric lavas which are hosts to a range of crustal xenoliths. Entrained xenoliths contain evidence for partial melting in the form of quenched anatectic melts (now glass). The compositions of these quenched crustal melts hold key information regarding how ascending magmas interact with surrounding crustal wall rocks and how in turn, the crust melts. Analyses of glasses for their major element (EMP), trace element (LA-ICPMS) and Sr isotopic composition (microdrill-TIMS) aim to improve our knowledge of mass transfer during crust-magma interaction and highlight the limitations of current models of crustal contamination which employ bulk rock compositions in calculations e.g. (EC)AFC modelling, DePoalo, 1981; Spera & Bohrson, 2001. References Davidson, J.P., Hora, J.M., Garrison, J.M. and Dungan, M.A., (2005). Crustal Forensics in Arc Magmas

  17. Different selection pressures give rise to distinct ethnic phenomena : a functionalist framework with illustrations from the Peruvian Altiplano.

    PubMed

    Moya, Cristina; Boyd, Robert

    2015-03-01

    Many accounts of ethnic phenomena imply that processes such as stereotyping, essentialism, ethnocentrism, and intergroup hostility stem from a unitary adaptation for reasoning about groups. This is partly justified by the phenomena's co-occurrence in correlational studies. Here we argue that these behaviors are better modeled as functionally independent adaptations that arose in response to different selection pressures throughout human evolution. As such, different mechanisms may be triggered by different group boundaries within a single society. We illustrate this functionalist framework using ethnographic work from the Quechua-Aymara language boundary in the Peruvian Altiplano. We show that different group boundaries motivate different ethnic phenomena. For example, people have strong stereotypes about socioeconomic categories, which are not cooperative units, whereas they hold fewer stereotypes about communities, which are the primary focus of cooperative activity. We also show that, despite the cross-cultural importance of ethnolinguistic boundaries, the Quechua-Aymara linguistic distinction does not strongly motivate any of these intergroup processes.

  18. [The voluntary health auxiliary. Application to the Peruvian Altiplano of new concepts of primary health care in disadvantaged communities].

    PubMed

    Gachoud, P

    1979-05-01

    A group a Swiss physicians, who have been working for about eight years in rural health posts of the Peruvian highlands (Altiplano), engaged in training voluntary health auxiliaries, chosen by the indigenous communities. Experience has shown that, as in other countries, it is thus possible to markedly improve the health of populations which badly lack resources. The efficacy of using such auxiliaries was recognized by the Peruvian Ministry of Health, which has now set up a programme for their training and supervision. Within the concept of primary health care, based on the participation of people to the management of their health, the voluntary health auxiliary is placed in a strategic and decisive position for the success of an enterprise which is now spreading to many countries of the Third World.

  19. Discrimination and supervised classification of volcanic flows of the Puna-Altiplano, Central Andes Mountains using Landsat TM data

    NASA Technical Reports Server (NTRS)

    Mcbride, J. H.; Fielding, E. J.; Isacks, B. L.

    1987-01-01

    Landsat Thematic Mapper (TM) images of portions of the Central Andean Puna-Altiplano volcanic belt have been tested for the feasibility of discriminating individual volcanic flows using supervised classifications. This technique distinguishes volcanic rock classes as well as individual phases (i.e., relative age groups) within each class. The spectral signature of a volcanic rock class appears to depend on original texture and composition and on the degree of erosion, weathering, and chemical alteration. Basalts and basaltic andesite stand out as a clearly distinguishable class. The age dependent degree of weathering of these generally dark volcanic rocks can be correlated with reflectance: older rocks have a higher reflectance. On the basis of this relationship, basaltaic lava flows can be separated into several subclasses. These individual subclasses would correspond to mappable geologic units on the ground at a reconnaissance scale. The supervised classification maps are therefore useful for establishing a general stratigraphic framework for later detailed surface mapping of volcanic sequences.

  20. Comparison of microbial and sorbed soil gas surgace geochemical techniques with seismic surveys from the Southern Altiplano, Bolivia

    SciTech Connect

    Aranibar, O.R.; Tucker, J.D.; Hiltzman, D.C.

    1995-12-31

    Yacimientos Petroliferos Fiscales Bolivianos (YPFB) undertook a large seismic evaluation in the southern Altiplano, Bolivia in 1994. As an additional layer of information, sorbed soil gas and Microbial Oil Survey Technique (MOST) geochemical surveys were conducted to evaluate the hydrocarbon microseepage potential. The Wara Sara Prospect had 387 sorbed soil gas samples, collected from one meter depth, and 539 shallow soil microbial samples, collected from 15 to 20 centimeter depth. The sorbed soil gas samples were collected every 500 meters and microbial samples every 250 meters along geochemical traverses spaced 1 km apart. The presence of anmalous hydrocarbon microseepage is indicated by (1) a single hydrocarbon source identified by gas crossplots, (2) the high gas values with a broad range, (3) the high overall gas average, (4) the clusters of elevated samples, and (5) the right hand skewed data distributions.

  1. Relationships between host species and morphometric patterns in Fasciola hepatica adults and eggs from the northern Bolivian Altiplano hyperendemic region.

    PubMed

    Valero, M A; Darce, N A; Panova, M; Mas-Coma, S

    2001-12-01

    The highest prevalences and intensities of human fasciolosis by Fasciola hepatica are found in the northern Bolivian Altiplano, where sheep and cattle are the main reservoir host species and pigs and donkeys the secondary ones. Morphometric comparisons of many linear measurements, areas and ratios of F. hepatica adults (from sheep, cattle and pigs) and eggs (from sheep, cattle, pigs and donkeys) in natural liver fluke populations of the Bolivian Altiplano, as well as of F. hepatica adults and eggs experimentally obtained in Wistar rats infected with Altiplanic sheep, cattle and pig isolates, were made using computer image analysis and an allometric model. Although morphometric values of adult flukes from natural populations of sheep, cattle, and pigs showed great overlap, there were clear differences in allometric growth. The allometries analyzed were: body area (BA) versus body length (BL), BA versus body width (BW), BA versus perimeter (Pe), BA versus distance between posterior end of body and ventral sucker (P-VS), BL versus BW, BL versus Pe, and BL versus P-VS. These allometries show a good fit in the seven pairs of variables in all the populations examined. Comparative statistical analysis of the allometries shows that fluke adult populations from sheep, cattle and pigs significantly differ in BL versus BW and BL versus P-VS functions. Statistical analysis of F. hepatica egg size shows characteristic morphometric traits in each definitive host species. In experimentally infected rats, fluke adult allometry and egg morphometry do not vary depending on the Altiplanic definitive host species isolate. Our study reveals that the definitive host species decisively influences the size of F. hepatica adults and eggs, and these influences do not persist in a rodent definitive host model.

  2. Oligocene-Miocene deformational and depositional history of the Andean hinterland basin in the northern Altiplano plateau, southern Peru

    NASA Astrophysics Data System (ADS)

    Perez, Nicholas D.; Horton, Brian K.

    2014-09-01

    Cenozoic basin fill of the northern Altiplano plateau records the tectonic development of the flanking Western Cordillera magmatic arc and Eastern Cordillera fold-thrust belt. The Ayaviri hinterland basin of southern Peru contains a ~2300 m thick succession of fluvial sandstones and overbank siltstones (upper Oligocene Puno Group and lower Miocene lower Tinajani Formation) capped by ~400 m of alluvial fan conglomerates (middle Miocene upper Tinajani Formation). New U-Pb zircon chronostratigraphic constraints from ~30 to 15 Ma yield sediment accumulation rates of 110-660 m/Myr. Newly dated growth strata highlight the genetic role played by thrust displacement in basin evolution. A several phase accumulation history derived from chronostratigraphic, provenance, and structural data reveals Oligocene basin filling by fluvial sand and mud that changes provenance from Western Cordillera Mesozoic-Cenozoic volcanic rocks to Paleozoic-Mesozoic Eastern Cordillera sedimentary rocks driven by deformation along the southwest directed, northeastern basin margin Ayaviri thrust at 28-26 Ma. Continued early Miocene fluvial deposition was sourced solely from the Eastern Cordillera. An abrupt middle Miocene shift to coarse alluvial fan deposition sourced from the Western Cordillera was driven by out-of-sequence deformation along the northeast directed, southwestern basin margin Pasani thrust at 18-16 Ma. This northern Altiplano out-of-sequence deformation was coincident with increased Eastern and Western Cordillera exhumation and thrusting and may be symptomatic of changes in critical wedge dynamics. The overall record of basin sedimentation and syndepositional fold-thrust deformation emphasizes the role of regional shortening in governing crustal thickening and basin evolution in the central Andes during the Oligocene to Miocene.

  3. Administration of Triclabendazole Is Safe and Effective in Controlling Fascioliasis in an Endemic Community of the Bolivian Altiplano

    PubMed Central

    Villegas, Fidel; Angles, René; Barrientos, René; Barrios, Gary; Valero, María Adela; Hamed, Kamal; Grueninger, Heiner; Ault, Steven K.; Montresor, Antonio; Engels, Dirk; Mas-Coma, Santiago; Gabrielli, Albis Francesco

    2012-01-01

    Background The Bolivian northern Altiplano is characterized by a high prevalence of Fasciola hepatica infection. In order to assess the feasibility, safety and efficacy of large-scale administration of triclabendazole as an appropriate public health measure to control morbidity associated with fascioliasis, a pilot intervention was implemented in 2008. Materials and Methods Schoolchildren from an endemic community were screened for fascioliasis and treated with a single administration of triclabendazole (10 mg/kg). Interviews to assess the occurrence of adverse events were conducted on treatment day, one week later, and one month after treatment. Further parasitological screenings were performed three months after treatment and again two months later (following a further treatment) in order to evaluate the efficacy of the intervention. Results Ninety infected children were administered triclabendazole. Adverse events were infrequent and mild. No serious adverse events were reported. Observed cure rates were 77.8% after one treatment and 97.8% after two treatments, while egg reduction rates ranged between 74% and 90.3% after one treatment, and between 84.2% and 99.9% after two treatments. The proportion of high-intensity infections (≥400 epg) decreased from 7.8% to 1.1% after one treatment and to 0% after two treatments. Conclusion Administration of triclabendazole is a feasible, safe and efficacious public health intervention in an endemic community in the Bolivian Altiplano, suggesting that preventive chemotherapy can be applied to control of fascioliasis. Further investigations are needed to define the most appropriate frequency of treatment. PMID:22880138

  4. Pockmarks off Big Sur, California

    USGS Publications Warehouse

    Paull, C.; Ussler, W.; Maher, N.; Greene, H. Gary; Rehder, G.; Lorenson, T.; Lee, H.

    2002-01-01

    A pockmark field was discovered during EM-300 multi-beam bathymetric surveys on the lower continental slope off the Big Sur coast of California. The field contains ??? 1500 pockmarks which are between 130 and 260 m in diameter, and typically are 8-12 m deep located within a 560 km2 area. To investigate the origin of these features, piston cores were collected from both the interior and the flanks of the pockmarks, and remotely operated vehicle observation (ROV) video and sampling transects were conducted which passed through 19 of the pockmarks. The water column within and above the pockmarks was sampled for methane concentration. Piston cores and ROV collected push cores show that the pockmark field is composed of monotonous fine silts and clays and the cores within the pockmarks are indistinguishable from those outside the pockmarks. No evidence for either sediment winnowing or diagenetic alteration suggestive of fluid venting was obtained. 14C measurements of the organic carbon in the sediments indicate continuous sedimentation throughout the time resolution of the radiocarbon technique ( ??? 45000 yr BP), with a sedimentation rate of ??? 10 cm per 1000 yr both within and between the pockmarks. Concentrations of methane, dissolved inorganic carbon, sulfate, chloride, and ammonium in pore water extracted from within the cores are generally similar in composition to seawater and show little change with depth, suggesting low biogeochemical activity. These pore water chemical gradients indicate that neither significant accumulations of gas are likely to exist in the shallow subsurface ( ??? 100 m) nor is active fluid advection occurring within the sampled sediments. Taken together the data indicate that these pockmarks are more than 45000 yr old, are presently inactive, and contain no indications of earlier fluid or gas venting events. ?? 2002 Elsevier Science B.V. All rights reserved.

  5. A rare case of grass flow induced by the M8.4 Arequipa earthquake, June 2001, in the Altiplano of Northern Chile

    NASA Astrophysics Data System (ADS)

    Naranjo, José A.; Clavero, Jorge E.

    2005-09-01

    On June 23, 2001, an M8.4 earthquake that originated in southern Peru triggered the partial collapse of the Chislluma bofedal (water meadows) in the Altiplano (high-altitude plateau) of northern Chile. The seismic waves evidently produced the liquefaction of the bofedal and caused its partial collapse generating a flow. The flow deposit was mainly made of long-fiber grass and water, with minor amounts of clastic material. It traveled more than 14 km downstream at a peak velocity of 50 km/h. It destroyed the water meadows and killed more than 20 llamas. Slurry flows caused by meadow liquefaction are a previously unrecognized seismic-induced geological hazard for high-altitude plateau areas such as the Altiplano.

  6. Phylogeography and genetic divergence of some lymnaeid snails, intermediate hosts of human and animal fascioliasis with special reference to lymnaeids from the Bolivian Altiplano.

    PubMed

    Jabbour-Zahab, R; Pointier, J P; Jourdane, J; Jarne, P; Oviedo, J A; Bargues, M D; Mas-Coma, S; Anglés, R; Perera, G; Balzan, C; Khallayoune, K; Renaud, F

    1997-04-15

    A population genetic study using starch gel electrophoresis was performed on populations of several species of lymnaeid snails acting as intermediate hosts for Fasciola hepatica (Trematoda, Plathyhelminth). Lymnaea viatrix was collected in 16 sites from the Bolivian Northern Altiplano. L. cubensis were obtained in one site from Venezuela, one site from Guadeloupe, three sites from Cuba and one site from the Dominican Republic. L. truncatula were collected in one site from France, one from Portugal and one from Morocco. Multilocus enzyme electrophoresis (MEE) were determined for 282 snails at 18 loci. A complete monomorphism was encountered at each geographic site. However, among these 18 loci, 13 are polymorphic and low and high levels of genetic divergence were observed between samples. Two genotypic groups can be differentiated by their multilocus genotypes. The western genotypic group associates together samples from Venezuela, Guadeloupe, Cuba and Dominican Republic (L. cubensis) while samples from France, Portugal and Morocco (L. truncatula) belong to the eastern genotypic group. Surprisingly, the Northern Bolivian Altiplano populations (L. viatrix) do not present any genetic divergence with the Portuguese sample. Therefore, the Bolivian snails belong entirely to the eastern genetic group. Within each group slight genetic divergences were observed. These results strongly support the European origin of the lymnaeid snails from the Northern Bolivian Altiplano.

  7. AirMSPI PODEX BigSur Terrain Images

    Atmospheric Science Data Center

    2013-12-13

    ... from the PODEX 2013 Campaign   Big Sur target (Big Sur, California) 02/03/2013 Terrain-projected   Select ...   Version number   For more information, see the Data Product Specifications (DPS)   ...

  8. Climate and lake-level history of the northern altiplano, Bolivia, as recorded in holocene sediments of the Rio Desaguadero

    USGS Publications Warehouse

    Baucom, P.C.; Rigsby, C.A.

    1999-01-01

    Strata exposed in terraces and modern cutbanks along the Rio Desaguadero contain a variety of lithofacies that were deposited in four distinct facie??s associations. These facie??s associations document a history of aggradation and downcutting that is linked to Holocene climate change on the Altiplano. Braided-stream, meandering-stream, deltaic and shoreline, and lacustrine sediments preserved in multi-level terraces in the northern Rio Desaguadero valley record two high-water intervals: one between 4500 and 3900 yr BP and another between 2000 and 2200 yr BP. These wet periods were interrupted by three periods of fluvial downcutting, centered at approximately 4000 yr BP, 3600 yr BP, and after 2000 yr BP. Braided-river sediments preserved in a single terrace level in the southern Rio Desaguadero valley record a history of nearly continuous fluvial sedimentation from at least 7000 yr BP until approximately 3200 yr BP that was followed by a single episode (post-3210 yr BP) of downcutting and lateral migration. The deposition and subsequent fluvial downcutting of the northern strata was controlled by changes in effective moisture that can be correlated to Holocene water-level fluctuations of Lake Titicaca. The deposition and dissection of braided-stream sediments to the south are more likely controlled by a combination of base-level change and sediment input from the Rio Mauri. Copyright ??1999, SEPM (Society for Sedimentar)- Geology).

  9. Physical features, phenolic compounds, betalains and total antioxidant capacity of coloured quinoa seeds (Chenopodium quinoa Willd.) from Peruvian Altiplano.

    PubMed

    Abderrahim, Fatima; Huanatico, Elizabeth; Segura, Roger; Arribas, Silvia; Gonzalez, M Carmen; Condezo-Hoyos, Luis

    2015-09-15

    Physical features, bioactive compounds and total antioxidant capacity (TAC) of coloured quinoa varieties (Chenopodium quinoa Willd.) from Peruvian Altiplano were studied. Quinoa seeds did not show a pure red colour, but a mixture which corresponded to different fractal colour values (51.0-71.8), and they varied from small to large size. Regarding bioactive compounds, total phenolic (1.23-3.24mg gallic acid equivalents/g) and flavonol contents (0.47-2.55mg quercetin equivalents/g) were highly correlated (r=0.910). Betalains content (0.15-6.10mg/100g) was correlated with L colour parameter (r=-0.569), total phenolics (r=0.703) and flavonols content (r=0.718). Ratio of betaxanthins to betacyanins (0.0-1.41) was negatively correlated with L value (r=-0.744). Whereas, high TAC values (119.8-335.9mmol Trolox equivalents/kg) were negatively correlated with L value (r=-0.779), but positively with betalains (r=0.730), as well as with free (r=0.639), bound (r=0.558) and total phenolic compounds (r=0.676). Unexploited coloured quinoa seeds are proposed as a valuable natural source of phenolics and betalains with high antioxidant capacity.

  10. Climate change and the distribution and conservation of the world's highest elevation woodlands in the South American Altiplano

    NASA Astrophysics Data System (ADS)

    Cuyckens, G. A. E.; Christie, D. A.; Domic, A. I.; Malizia, L. R.; Renison, D.

    2016-02-01

    Climate change is becoming an increasing threat to biodiversity. Consequently, methods for delineation, establishment and management of protected areas must consider the species' future distribution in response to future climate conditions. Biodiversity in high altitude semiarid regions may be particularly threatened by future climate change. In this study we assess the main environmental variables that best explain present day presence of the world's highest elevation woodlands in the South American Altiplano, and model how climate change may affect the future distribution of this unique ecosystem under different climate change scenarios. These woodlands are dominated by Polylepis tarapacana (Rosaceae), a species that forms unique biological communities with important conservation value. Our results indicate that five environmental variables are responsible for 91% and 90.3% of the present and future P. tarapacana distribution models respectively, and suggest that at the end of the 21st century, there will be a significant reduction (56%) in the potential habitat for this species due to more arid conditions. Since it is predicted that P. tarapacana's potential distribution will be severely reduced in the future, we propose a new network of national protected areas across this species distribution range in order to insure the future conservation of this unique ecosystem. Based on an extensive literature review we identify research topics and recommendations for on-ground conservation and management of P. tarapacana woodlands.

  11. Analysis of subsurface temperature data to quantify groundwater recharge rates in a closed Altiplano basin, northern Chile

    NASA Astrophysics Data System (ADS)

    Kikuchi, C. P.; Ferré, T. P. A.

    2016-09-01

    Quantifying groundwater recharge is a fundamental part of groundwater resource assessment and management, and is requisite to determining the safe yield of an aquifer. Natural groundwater recharge in arid and semi-arid regions comprises several mechanisms: in-place, mountain-front, and mountain-block recharge. A field study was undertaken in a high-plain basin in the Altiplano region of northern Chile to quantify the magnitude of in-place and mountain-front recharge. Water fluxes corresponding to both recharge mechanisms were calculated using heat as a natural tracer. To quantify in-place recharge, time-series temperature data in cased boreholes were collected, and the annual fluctuation at multiple depths analyzed to infer the water flux through the unsaturated zone. To quantify mountain-front recharge, time-series temperature data were collected in perennial and ephemeral stream channels. Streambed thermographs were analyzed to determine the onset and duration of flow in ephemeral channels, and the vertical water fluxes into both perennial and ephemeral channels. The point flux estimates in streambeds and the unsaturated zone were upscaled to channel and basin-floor areas to provide comparative estimates of the range of volumetric recharge rates corresponding to each recharge mechanism. The results of this study show that mountain-front recharge is substantially more important than in-place recharge in this basin. The results further demonstrate the worth of time-series subsurface temperature data to characterize both in-place and mountain-front recharge processes.

  12. Climate and lake-level history of the northern Altiplano, Bolivia, as recorded in Holocene sediments of the Rio Desaguadero

    SciTech Connect

    Baucom, P.C.; Rigsby, C.A.

    1999-05-01

    Strata exposed in terraces and modern cutbanks along the Rio Desaguadero contain a variety of lithofacies that were deposited in four distinct facies associations. These facies associations document a history of aggradation and downcutting that is linked to Holocene climate change on the Altiplano. Braided-stream, meandering-stream, deltaic and shoreline, and lacustrine sediments preserved in multi-level terraces in the northern Rio Desaguadero valley record two high-water intervals: one between 4,500 and 3,900 yr BP and another between 2,000 and 2,200 yr BP. These wet periods were interrupted by three periods of fluvial downcutting, centered at approximately 4,000 yr BP, 3,600 yr BP, and after 2,000 yr BP. Braided-river sediments preserved in a single terrace level in the southern Rio Desaguadero valley record a history of nearly continuous fluvial sedimentation from at least 7,000 yr BP until approximately 3,200 yr BP that was followed by a single episode (post-3,210 yr BP) of down-cutting and lateral migration. The deposition and subsequent fluvial downcutting of the northern strata was controlled by changes in effective moisture that can be correlated to Holocene water-level fluctuations of Lake Titicaca. The deposition and dissection of braided-stream sediments to the south are more likely controlled by a combination of base-level change and sediment input from the Rio Mauri.

  13. The challenges of exploring near the fringes of space: A case history of seismically exploring the Altiplano Basin of Bolivia

    SciTech Connect

    Prideaux, B.R.; Bayne, J.W.

    1994-12-31

    Obtaining the quality seismic data necessary to answer key exploration questions in the Altiplano Basin of Bolivia necessitated the use of turbo-charged vibrators, ground force control electronics, and state of the art processing techniques. Overcoming the structural complexity of the region, including steep surface dips (averaging 45{degree}--50{degree}), even steeper subsurface dips adjacent to areas of near-flat dip, as well as substantial surface variations, required optimal recording and processing parameters. A long far offset (3056.75 m) and a close trace spacing (12.5 m) was needed to acquire the most reliable data. Seven second records were also recorded to insure that information was acquired at depth. Several other factors helped account for an acquisition success for the project. A field computer system was used to quickly process brute and enhanced brute stacks, which provided greater quality control and allowed for in-field adjustments to optimize the acquisition parameters. Additionally, the processing of the data was able to minimize numerous problems. There was a high variance in the recorded data quality, mainly due to surface and near-surface conditions (statics), as well as a fairly high degree of background noise throughout. These noise problems eventually determined the processing sequence that was used. Some processes that were initially proposed deteriorated instead of enhanced the interpretability of the seismic data.

  14. Physical features, phenolic compounds, betalains and total antioxidant capacity of coloured quinoa seeds (Chenopodium quinoa Willd.) from Peruvian Altiplano.

    PubMed

    Abderrahim, Fatima; Huanatico, Elizabeth; Segura, Roger; Arribas, Silvia; Gonzalez, M Carmen; Condezo-Hoyos, Luis

    2015-09-15

    Physical features, bioactive compounds and total antioxidant capacity (TAC) of coloured quinoa varieties (Chenopodium quinoa Willd.) from Peruvian Altiplano were studied. Quinoa seeds did not show a pure red colour, but a mixture which corresponded to different fractal colour values (51.0-71.8), and they varied from small to large size. Regarding bioactive compounds, total phenolic (1.23-3.24mg gallic acid equivalents/g) and flavonol contents (0.47-2.55mg quercetin equivalents/g) were highly correlated (r=0.910). Betalains content (0.15-6.10mg/100g) was correlated with L colour parameter (r=-0.569), total phenolics (r=0.703) and flavonols content (r=0.718). Ratio of betaxanthins to betacyanins (0.0-1.41) was negatively correlated with L value (r=-0.744). Whereas, high TAC values (119.8-335.9mmol Trolox equivalents/kg) were negatively correlated with L value (r=-0.779), but positively with betalains (r=0.730), as well as with free (r=0.639), bound (r=0.558) and total phenolic compounds (r=0.676). Unexploited coloured quinoa seeds are proposed as a valuable natural source of phenolics and betalains with high antioxidant capacity. PMID:25863614

  15. Evolved priors for ethnolinguistic categorization: A case study from the Quechua-Aymara boundary in the Peruvian Altiplano.

    PubMed

    Moya, Cristina

    2013-07-01

    Ethnic categories uniquely structure human social worlds. People readily form stereotypes about these, and other social categories, but it is unclear whether certain dimensions are privileged for making predictions about strangers when information is limited. If humans have been living in culturally-structured groups for much of their evolutionary history, we might expect them to have adaptations for prioritizing ethno-linguistic cues as a basis for making predictions about others. We provide a strong test of this possibility through a series of studies in a field context along the Quechua-Aymara linguistic boundary in the Peruvian Altiplano where the language boundary is not particularly socially meaningful. We find evidence of such psychological priors among children and adults at this site by showing that their age, and the social categories' novelty affect participants' reliance on ethno-linguistic inductive inferences (i.e. one-to-many predictions). Studies 1-3 show that participants make more ethno-linguistic inferences when the social categories are more removed from their real-world context. Additionally, in Study 4 when the category is marked with acoustic cues of language use, young children rely heavily on ethno-linguistic predictions, even though adults do not.

  16. Phylogenetic and phylogeographic analysis of the genus Orestias (Teleostei: Cyprinodontidae) in the southern Chilean Altiplano: the relevance of ancient and recent divergence processes in speciation.

    PubMed

    Vila, I; Morales, P; Scott, S; Poulin, E; Véliz, D; Harrod, C; Méndez, M A

    2013-03-01

    This study presents phylogenetic molecular data of the Chilean species of Orestias to propose an allopatric divergence hypothesis and phylogeographic evidence that suggests the relevance of abiotic factors in promoting population divergence in this complex. The results reveal that diversification is still ongoing, e.g. in the Ascotán salt pan, where populations of Orestias ascotanensis restricted to individual freshwater springs exhibit strong genetic differentiation, reflecting putative independent evolutionary units. Diversification of Orestias in the southern Altiplano may be linked to historical vicariant events and contemporary variation in water level; these processes may have affected the populations from the Plio-Pleistocene until the present.

  17. SO2-flux measurements and BrO/SO2 ratios at Guallatiri volcano, Altiplano, northern Chile

    NASA Astrophysics Data System (ADS)

    Gliss, Jonas; Stebel, Kerstin; Thomas, Helen

    2015-04-01

    Sulphur dioxide (SO2) fluxes were measured recently at Guallatiri volcano using two UV SO2-cameras and one IR SO2-camera. Furthermore, measurements of reactive halogens (e.g. BrO, OClO) were investigated using a high performance DOAS (Differential Optical Absorption Spectroscopy) instrument. Guallatiri (18° 25' 00″ S, 69° 5' 30″ W, 6.071 m a.s.l.) is situated in the Altiplano in northern Chile, close to the Bolivian border. The last known eruption of Guallatiri was in 1960. The measurements were performed during a short-term field trip on three days in November 2014 (20.11.-22.11.2014). During that time, the volcano showed a quiescent degassing behaviour from the summit crater and from a fumarolic field on the southern flank. A preliminary evaluation of the spectra recorded with the DOAS instruments showed SO2 column amounts (SCDs) up to 3 - 1017 molec/cm2 and BrO-SCDs of the order of several 1013 molec/cm2. This corresponds to BrO/SO2-ratios of the order of 10-4 which is a typical order of magnitude for volcanic emissions. We will present SO2-flux estimates for Guallatiri volcano during these three days as well as BrO/SO2-ratio estimates in dependence of different plume ages. Furthermore, we will compare the results retrieved with the two UV-cameras with the data recorded simultaneously with the IR-camera.

  18. Diurnal variability and biogeochemical reactivity of mercury species in an extreme high-altitude lake ecosystem of the Bolivian Altiplano.

    PubMed

    Alanoca, L; Amouroux, D; Monperrus, M; Tessier, E; Goni, M; Guyoneaud, R; Acha, D; Gassie, C; Audry, S; Garcia, M E; Quintanilla, J; Point, D

    2016-04-01

    Methylation and demethylation represent major transformation pathways regulating the net production of methylmercury (MMHg). Very few studies have documented Hg reactivity and transformation in extreme high-altitude lake ecosystems. Mercury (Hg) species concentrations (IHg, MMHg, Hg°, and DMHg) and in situ Hg methylation (M) and MMHg demethylation (D) potentials were determined in water, sediment, floating organic aggregates, and periphyton compartments of a shallow productive Lake of the Bolivian Altiplano (Uru Uru Lake, 3686 m). Samples were collected during late dry season (October 2010) and late wet season (May 2011) at a north (NS) and a south (SS) site of the lake, respectively. Mercury species concentrations exhibited significant diurnal variability as influenced by the strong diurnal biogeochemical gradients. Particularly high methylated mercury concentrations (0.2 to 4.5 ng L(-1) for MMHgT) were determined in the water column evidencing important Hg methylation in this ecosystem. Methylation and D potentials range were, respectively, <0.1-16.5 and <0.2-68.3 % day(-1) and were highly variable among compartments of the lake, but always higher during the dry season. Net Hg M indicates that the influence of urban and mining effluent (NS) promotes MMHg production in both water (up to 0.45 ng MMHg L(-1) day(-1)) and sediment compartments (2.0 to 19.7 ng MMHg g(-1) day(-1)). While the sediment compartment appears to represent a major source of MMHg in this shallow ecosystem, floating organic aggregates (dry season, SS) and Totora's periphyton (wet season, NS) were found to act as a significant source (5.8 ng MMHg g(-1) day(-1)) and a sink (-2.1 ng MMHg g(-1) day(-1)) of MMHg, respectively. This work demonstrates that high-altitude productive lake ecosystems can promote MMHg formation in various compartments supporting recent observations of high Hg contents in fish and water birds.

  19. Immunodiagnosis of Fasciola hepatica infection (fascioliasis) in a human population in the Bolivian Altiplano using purified cathepsin L cysteine proteinase.

    PubMed

    O'Neill, S M; Parkinson, M; Strauss, W; Angles, R; Dalton, J P

    1998-04-01

    Cathepsin L1 (CL1), an immunogenic cysteine proteinase secreted by juvenile and adult Fasciola hepatica, was assessed for its potential as a diagnostic agent for the serologic detection of human fascioliasis. Using ELISAs, we compared the ability of liver fluke homogenates (LFH), excretory/secretory (ES) products, and CL1 to discriminate between seropositive (infected) and seronegative (noninfected) individuals within a population of 95 patients from the Bolivian Altiplano. A high prevalence of human fascioliasis has been reported in this region. The division between the seropositive and seronegative individuals was poorly defined when LFH was used as the antigen. A greater discrimination between these populations was achieved with both ES and CL1. A K-means cluster analysis using the combined ES and CL1 ELISA data identified a cluster of seropositive individuals. Cathepsin L1 detected a subset (20) of these seropositive individuals while ES detected all 26; however, ES detected nine additional individuals that were in the seronegative cluster. The ratio of the mean absorbance readings between seropositive and seronegative individuals was markedly improved by using conjugated second antibodies to IgG4, the predominant isotype elicited by infection. In these IgG4-ELISAs, CL1 again identified fewer individuals as seropositive than did ES, but improved the discrimination between the seropositive and seronegative individuals and thus provided a more conclusive diagnosis. Sera obtained from patients infected with schistosomiasis mansoni, cysticercosis, hydatidosis, and Chagas' disease were negative in these assays, which demonstrated the specificity of the IgG4-ELISA for detecting fascioliasis. Twenty of the 95 patients (21%) were seropositive for fascioliasis by the CL1 IgG4-ELISA, confirming the earlier reports of the high prevalence of disease in this region. A standardized diagnostic test for human fascioliasis, based on an ELISA that detects IgG4 responses to CL1

  20. Arsenic and other trace elements in thermal springs and in cold waters from drinking water wells on the Bolivian Altiplano

    NASA Astrophysics Data System (ADS)

    Ormachea Muñoz, Mauricio; Bhattacharya, Prosun; Sracek, Ondra; Ramos Ramos, Oswaldo; Quintanilla Aguirre, Jorge; Bundschuh, Jochen; Maity, Jyoti Prakash

    2015-07-01

    Numerous hot springs and fumaroles occur along the Andes Mountains, in the Bolivian Altiplano, where people use thermal springs for recreational purposes as pools, baths and also for consumption as drinking water and irrigation once it is mixed with natural surface waters; most of these thermal springs emerge from earth surface and flow naturally into the rivers streams which drain further into the Poopó Lake. Physicochemical characteristics of the thermal water samples showed pH from 6.3 to 8.3 with an average of 7.0, redox potential from +106 to +204 mV with an average of +172 mV, temperatures from 40 to 75 °C with an average of 56 °C and high electrical conductivity ranging from 1.8 to 75 mS/cm and averaged 13 mS/cm. Predominant major ions are Na+ and Cl- and the principal water types are 37.5% Na-Cl type and 37.5% Na-Cl-HCO3 type. Arsenic concentrations ranged from 7.8 to 65.3 μg/L and arsenic speciation indicate the predominance of As(III) species. Sediments collected from the outlets of thermal waters show high iron content, and ferric oxides and hydroxides are assumed to be principal mineral phases for arsenic attenuation by adsorption/co-precipitation processes. Arsenic concentrations in cold water samples from shallow aquifers are higher than those in thermal springs (range < 5.6-233.2 μg/L), it is likely that thermal water discharge is not the main source of high arsenic content in the shallow aquifer as they are very immature and may only have a small component corresponding to the deep geothermal reservoir. As people use both thermal waters and cold waters for consumption, there is a high risk for arsenic exposure in the area.

  1. New paleomagnetic data from Upper Oligocene-Lower Miocene rocks of the Northern Argentine Puna-Southern Bolivian Altiplano: Constraining the age of vertical axis rotations

    NASA Astrophysics Data System (ADS)

    Prezzi, Claudia B.; Caffe, Pablo J.; Iglesia Llanos, María P.; Orgeira, María J.

    2014-08-01

    Along the Central Andes a pattern of vertical axis rotations has been paleomagnetically identified. Such rotations are counterclockwise north of Arica Deflection (∼19° S) and clockwise to the south. Different hypothesis and models have been proposed to explain the Central Andean Rotation Pattern (CARP). However, the origin of the CARP is a subject of ongoing debate. Recently, different authors have proposed the possible existence of a close correlation between the time-space distribution of deformation and the amount of registered vertical axis rotations in the Southern Central Andes. In order to further investigate such relationship, new paleomagnetic studies were carried out in Upper Oligocene-Lower Miocene rocks of the Northern Argentine Puna and the Southern Bolivian Altiplano. Our results indicate that while one of the sampled localities did not undergo significant vertical axis rotations, the other two recorded clockwise vertical axis rotations larger than 30°. These results suggest the occurrence of small-block rotations in the Southern Bolivian Altiplano-Northern Argentine Puna prior to 15 Ma, which would correspond to the local accommodation of the regional deformation field.

  2. Mineral mapping on the Chilean-Bolivian Altiplano using co-orbital ALI, ASTER and Hyperion imagery: Data dimensionality issues and solutions

    USGS Publications Warehouse

    Hubbard, B.E.; Crowley, J.K.

    2005-01-01

    Hyperspectral data coverage from the EO-1 Hyperion sensor was useful for calibrating Advanced Land Imager (ALI) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images of a volcanic terrane area of the Chilean-Bolivian Altiplano. Following calibration, the ALI and ASTER datasets were co-registered and joined to produce a 13-channel reflectance cube spanning the Visible to Short Wave Infrared (0.4-2.4 ??m). Eigen analysis and comparison of the Hyperion data with the ALI + ASTER reflectance data, as well as mapping results using various ALI+ASTER data subsets, provided insights into the information dimensionality of all the data. In particular, high spectral resolution, low signal-to-noise Hyperion data were only marginally better for mineral mapping than the merged 13-channel, low spectral resolution, high signal-to-noise ALI + ASTER dataset. Neither the Hyperion nor the combined ALI + ASTER datasets had sufficient information dimensionality for mapping the diverse range of surface materials exposed on the Altiplano. However, it is possible to optimize the use of the multispectral data for mineral-mapping purposes by careful data subsetting, and by employing other appropriate image-processing strategies.

  3. Sur8 mediates tumorigenesis and metastasis in colorectal cancer

    PubMed Central

    Lee, Young-Mi; Kaduwal, Saluja; Lee, Kug Hwa; Park, Jong-Chan; Jeong, Woo-Jeong; Choi, Kang-Yell

    2016-01-01

    Sur8, a scaffold protein of the Ras pathway, interacts with Ras and Raf and modulates the Ras-extracellular signal-regulated kinase (ERK) pathway. Here we show that Sur8 is overexpressed in established human colorectal cancer (CRC) cell lines and CRC patient tissues. Moreover, Sur8 expression is increased during liver metastasis in CRC patients. Sur8 knockdown decreases ERK and Akt activities in CRC cell lines, regardless of their K-Ras, B-Raf or PI3K mutation status. Overexpression or knockdown of Sur8 increases or decreases, respectively, the proliferation or transformation of CRC cell lines. Sur8 knockdown attenuates the migration and invasion of HCT116 CRC cells. Subcutaneous or orthotopic injection of HCT116 cells harboring a doxycycline (Dox)-mediated Sur8 knockdown system in nude mice resulted in decreased tumorigenic potential and inhibited the liver metastatic potential of HCT116 cells. Taken together, our data support the role of Sur8 as a promoter of tumorigenesis and liver metastasis in CRC through its modulation of the Ras-ERK and PI3K-Akt signaling pathways. PMID:27469030

  4. Sur8 mediates tumorigenesis and metastasis in colorectal cancer.

    PubMed

    Lee, Young-Mi; Kaduwal, Saluja; Lee, Kug Hwa; Park, Jong-Chan; Jeong, Woo-Jeong; Choi, Kang-Yell

    2016-01-01

    Sur8, a scaffold protein of the Ras pathway, interacts with Ras and Raf and modulates the Ras-extracellular signal-regulated kinase (ERK) pathway. Here we show that Sur8 is overexpressed in established human colorectal cancer (CRC) cell lines and CRC patient tissues. Moreover, Sur8 expression is increased during liver metastasis in CRC patients. Sur8 knockdown decreases ERK and Akt activities in CRC cell lines, regardless of their K-Ras, B-Raf or PI3K mutation status. Overexpression or knockdown of Sur8 increases or decreases, respectively, the proliferation or transformation of CRC cell lines. Sur8 knockdown attenuates the migration and invasion of HCT116 CRC cells. Subcutaneous or orthotopic injection of HCT116 cells harboring a doxycycline (Dox)-mediated Sur8 knockdown system in nude mice resulted in decreased tumorigenic potential and inhibited the liver metastatic potential of HCT116 cells. Taken together, our data support the role of Sur8 as a promoter of tumorigenesis and liver metastasis in CRC through its modulation of the Ras-ERK and PI3K-Akt signaling pathways. PMID:27469030

  5. Adolescence et pornographie sur la toile

    PubMed Central

    Haza, Marion

    2012-01-01

    Dans cet article, nous abordons la question de l’accès à la pornographie sur Internet par les adolescents. Nous déclinons plusieurs facettes de ces rencontres: la rencontre «fortuite», quand les adolescents sont confrontés à des images intempestives, des publicités ou spams avec des contenus pornographiques; la rencontre «spectatrice», quand les adolescents cherchent activement des vidéos ou photos mettant en scène la sexualité; et enfin la rencontre «actrice», quand les adolescents se mettent en scène eux-mêmes, seuls ou à plusieurs, de façon pornographique sur le Net. A partir d’exemple, nous réfléchissons aux enjeux de ces rencontres virtuelles précoces de la sexualité adulte par rapport au développement adolescent et à la représentation de leur propre sexualité en construction. PMID:22876261

  6. Widespread Lake Highstands in the Southernmost Andean Altiplano during Heinrich Event 1: Implications for the South American Summer Monsoon

    NASA Astrophysics Data System (ADS)

    Chen, C. Y.; McGee, D.; Quade, J.

    2014-12-01

    Speleothem-based oxygen isotope records provide strong evidence of anti-phased behavior of the northern and southern hemisphere summer monsoons during Heinrich events, but we lack rigorous constraints on the amount of wetting or drying occurring in monsoon regions. Studies centered on shoreline deposits of closed-basin lakes are well suited for establishing such quantitative controls on water balance changes by providing unequivocal evidence of lake volume variations. Here we present new dating constraints on the highstands of several high-altitude (3800-4350 m) paleolakes in the southern Andean Altiplano, an outlying arid region of the Atacama Desert stretching across the Chilean-Bolivian-Argentinian border east of the Andes (20-25°S). These lakes once occupied the closed basins where only phreatic playas, dry salars, and shallow ponds exist today. Initial U-Th dating of massive shoreline tufas reveals that these deposits are dateable to within ±150 to 300 yrs due to high U concentrations and low initial Th content (as indicated by high 230Th/232Th). Our U-Th and 14C dates show that lake highstands predominantly occur between 18.5 and 14.5 kyrs BP, coinciding with Heinrich Event 1 (HE1) and the expansion of other nearby lakes, such as Lake Titicaca. Because of their (1) location at the modern-day southwestern edge of the summer monsoon, (2) intact shoreline preservation, and (3) precise age control, these lakes may uniquely enable us to reconstruct the evolution of water balance (P-E) changes associated with HE1. Hydrologic modeling constrained by temperature estimates provided by local glacial records is used to provide bounds for past precipitation changes. We also examine North Atlantic cooling as the mechanism for these changes by comparing a compilation of S. American lake level records with various hosing experiments and transient climate simulations at HE1. Our results lend us confidence in expanding our U-Th work to other shoreline tufas in the

  7. Late Pleistocene pluton formation during the waning stages of the Altiplano-Puna ignimbrite flare-up

    NASA Astrophysics Data System (ADS)

    Tierney, C. R.; Schmitt, A. K.; Lovera, O. M.; de Silva, S. L.

    2015-12-01

    The latest phase of volcanism during the late Mio- to Pleistocene ignimbrite flare-up in the Altiplano-Puna Volcanic Complex consists of a series of late Pleistocene lava domes (Chao, Chillahuita, Chanka, Chascon-Runtu Jarita, and Tocopuri) which are distributed over a roughly elliptical area of ~2,000 km2. With a collective volume of ~40 km3, these represent a waning of magmatic activity from the peak of the flare-up. Zircon chronochemistry and zircon age spectra were modeled using a finite-difference thermal- and mass-balance model for open-system magma evolution (recharge-assimilation-fractional crystallization; RAFC) where zircon crystallization is treated in accord with experimentally calibrated zircon saturation. Zircon rims and interiors were dated (U-Th, U-Pb) for a total of 252 crystals distributed equally over the domes, with a ~50% subset also analyzed for trace elements. The domes share remarkably consistent zircon crystallization histories: the youngest zircon rim ages (ca. 83 to 104 ka) are near the 40Ar/39Ar eruption ages (ca. 87 to 120 ka; sanidine and biotite), but a significant population of rim ages predates eruption, often ranging to secular equilibrium. U-Pb interior ages of crystals with secular equilibrium rim ages date to ca. 2.0 Ma, and a single core of Chascon to 3.5 Ma. Ti-in-zircon, backed by indirectly T-dependent compositional parameters, show that zircon crystallized at steady-state in a magma reservoir with essentially insignificant (<10-4 °C/a) secular cooling. Most zircon rims postdate peak flare-up, but nevertheless record a protracted and continuous crystallization history. To match the record of zircon production, time-integrated recharge rates of ~1 ×10-3 km3/a are required. At lower rates, older zircon ages are predicted for the dominant zircon rim age population than observed. At higher rates zircon would crystallize late, resulting in a lack of antecrysts. Intermediate recharge rates that best match the data call for at

  8. Geogenic arsenic and other trace elements in the shallow hydrogeologic system of Southern Poopó Basin, Bolivian Altiplano.

    PubMed

    Ormachea Muñoz, Mauricio; Wern, Hannes; Johnsson, Fredrick; Bhattacharya, Prosun; Sracek, Ondra; Thunvik, Roger; Quintanilla, Jorge; Bundschuh, Jochen

    2013-11-15

    Environmental settings in the southern area of Lake Poopó in the Bolivian highlands, the Altiplano, have generated elevated amounts of arsenic (As) in the water. The area is characterised by a semiarid climate, slow hydrological flow and geologic formations of predominantly volcanic origin. The present study aimed at mapping the extent of the water contamination in the area and to investigate the geogenic sources and processes involved in the release of As to the groundwater. Ground- and surface-water samples were collected from 24 different sites, including drinking water wells and rivers, in the southern Poopó basin in two different field campaigns during the dry and rainy seasons. The results revealed variable levels of As in shallow drinking water wells and average concentration exceeding the WHO guidelines value. Arsenic concentrations range from below 5.2 μg/L (the detection level) to 207 μg/L and averages 72 μg/L. Additionally, high boron (B) concentrations (average 1902 μg/L), and high salinity are further serious concerns for deteriorating the groundwater quality and rendering it unsuitable for drinking. Groundwater is predominantly of the Na-Cl-HCO3 type or the Ca-Na-HCO3 type with neutral or slightly alkaline pH and oxidising character. While farmers are seriously concerned about the water scarcity, and on a few occasions about salinity, there are no concerns about As and B present at levels exceeding the WHO guidelines, and causing negative long term effects on human health. Sediment samples from two soil profiles and a river bed along with fourteen rock samples were also collected and analysed. Sequential extractions of the sediments together with the calculation of the mineral saturation indices indicate that iron oxides and hydroxides are the important secondary minerals phases which are important adsorbents for As. High pH values, and the competition of As with HCO3 and dissolved silica for the adsorption sites probably seems to be an

  9. Geogenic arsenic and other trace elements in the shallow hydrogeologic system of Southern Poopó Basin, Bolivian Altiplano.

    PubMed

    Ormachea Muñoz, Mauricio; Wern, Hannes; Johnsson, Fredrick; Bhattacharya, Prosun; Sracek, Ondra; Thunvik, Roger; Quintanilla, Jorge; Bundschuh, Jochen

    2013-11-15

    Environmental settings in the southern area of Lake Poopó in the Bolivian highlands, the Altiplano, have generated elevated amounts of arsenic (As) in the water. The area is characterised by a semiarid climate, slow hydrological flow and geologic formations of predominantly volcanic origin. The present study aimed at mapping the extent of the water contamination in the area and to investigate the geogenic sources and processes involved in the release of As to the groundwater. Ground- and surface-water samples were collected from 24 different sites, including drinking water wells and rivers, in the southern Poopó basin in two different field campaigns during the dry and rainy seasons. The results revealed variable levels of As in shallow drinking water wells and average concentration exceeding the WHO guidelines value. Arsenic concentrations range from below 5.2 μg/L (the detection level) to 207 μg/L and averages 72 μg/L. Additionally, high boron (B) concentrations (average 1902 μg/L), and high salinity are further serious concerns for deteriorating the groundwater quality and rendering it unsuitable for drinking. Groundwater is predominantly of the Na-Cl-HCO3 type or the Ca-Na-HCO3 type with neutral or slightly alkaline pH and oxidising character. While farmers are seriously concerned about the water scarcity, and on a few occasions about salinity, there are no concerns about As and B present at levels exceeding the WHO guidelines, and causing negative long term effects on human health. Sediment samples from two soil profiles and a river bed along with fourteen rock samples were also collected and analysed. Sequential extractions of the sediments together with the calculation of the mineral saturation indices indicate that iron oxides and hydroxides are the important secondary minerals phases which are important adsorbents for As. High pH values, and the competition of As with HCO3 and dissolved silica for the adsorption sites probably seems to be an

  10. Chemistry of Post 12 Ma Los Frailes Volcanic Complex Ignimbrites in Bolivia and the Role of Magmatism in the Uplift of the Central Andean Altiplano Plateau

    NASA Astrophysics Data System (ADS)

    Kay, S. M.; Keller, C. B.; Coira, B.; Jiménez, N.; Caffe, P. J.

    2010-12-01

    The giant (~2000 km3) backarc Los Frailes volcanic complex in the Bolivian Altiplano of the Central Andes records the late Oligocene to Pleistocene magmatic history of the Altiplano plateau whose time and processes of uplift are controversial. Most previous studies of the Los Frailes complex have concentrated on pre-12 Ma volcanic rocks that host Sn-Ag deposits including the world’s largest silver deposit at Cerro Rico. Here, we combine sparse pre-existing chemical data from post 12 Ma volcanic rocks with new major and trace element analyses to show that the voluminous post-12 Ma ignimbrites are predominantly peraluminous, K-rich biotite-bearing andesites and dacites (58-69% SiO2) that can contain calcic feldspar, orthopyroxene, cordierite, and ilmenite. Trace element data show that the ignimbrites have very steep REE patterns (La/Yb = 30-90) marked by HREE depletion (Sm/Yb = 5-9) requiring garnet as a deep-crustal restitic phase in a very thick crust. The presence of cordierite crystals in some ignimbrites requires final equilibration of the erupted magmas at depths of less than ~14 km (< 450 MPa). Other prominent chemical features include LIL enrichment (to 90 ppm La), non-arc like Ba/La ratios (<20) and HFSE/LREE ratios (La/Ta=35-50) as high as those in frontal arc magmas. Sparse 87Sr/86Sr ratios near 0.712 show the magmas contain significant crustal contributions. The least silicic ignimbrites with the lowest La/Yb ratios (25-35) are the voluminous ~7 Ma Livicucho/Condor Nasa andesites/dacites in the northern part of the complex. These ignimbrites erupted during an ~ 8.5 to ~6 Ma peak in backarc ignimbrite activity in the northern Puna to the south and the Altiplano to the north. These eruptions are approximately coincident with the 10-7 Ma period of rapid plateau uplift proposed by Molnar and Garzione (2007). Other widespread ignimbrites from across the main part of the Los Frailes plateau have chemical features in common with an ignimbrite flow dated at 2

  11. Lithiase géante sur enterocystoplastie

    PubMed Central

    Elmortaji, Khalid; Elomri, Ghassane; Bennani, Saad; Rabii, Redouane; Aboutaib, Rachid; Meziane, Fethi

    2014-01-01

    La formation des lithiases est une complication fréquente des entérocystoplasties après cystectomie radicale pour tumeur de vessie infiltrante. Le délai d'apparition dépend des facteurs de risque favorisants notamment les infections urinaires. Néanmoins la survenue de lithiase géante sur néovessie reste exceptionnelle, seulement 5 cas ont été rapportés dans la littérature. Nous rapportons dans ce travail, le cas d'une lithiase géante compliquant une entérocystoplastie chez un malade suivi pour tumeur de vessie infiltrante. PMID:25932070

  12. Groundwater flow in a closed basin with a saline shallow lake in a volcanic area: Laguna Tuyajto, northern Chilean Altiplano of the Andes.

    PubMed

    Herrera, Christian; Custodio, Emilio; Chong, Guillermo; Lambán, Luis Javier; Riquelme, Rodrigo; Wilke, Hans; Jódar, Jorge; Urrutia, Javier; Urqueta, Harry; Sarmiento, Alvaro; Gamboa, Carolina; Lictevout, Elisabeth

    2016-01-15

    Laguna Tuyajto is a small, shallow saline water lake in the Andean Altiplano of northern Chile. In the eastern side it is fed by springs that discharge groundwater of the nearby volcanic aquifers. The area is arid: rainfall does not exceed 200mm/year in the rainiest parts. The stable isotopic content of spring water shows that the recharge is originated mainly from winter rain, snow melt, and to a lesser extent from some short and intense sporadic rainfall events. Most of the spring water outflowing in the northern side of Laguna Tuyajto is recharged in the Tuyajto volcano. Most of the spring water in the eastern side and groundwater are recharged at higher elevations, in the rims of the nearby endorheic basins of Pampa Colorada and Pampa Las Tecas to the East. The presence of tritium in some deep wells in Pampa Colorada and Pampa Las Tecas indicates recent recharge. Gas emission in recent volcanoes increase the sulfate content of atmospheric deposition and this is reflected in local groundwater. The chemical composition and concentration of spring waters are the result of meteoric water evapo-concentration, water-rock interaction, and mainly the dissolution of old and buried evaporitic deposits. Groundwater flow is mostly shallow due to a low permeability ignimbrite layer of regional extent, which also hinders brine spreading below and around the lake. High deep temperatures near the recent Tuyajto volcano explain the high dissolved silica contents and the δ(18)O shift to heavier values found in some of the spring waters. Laguna Tuyajto is a terminal lake where salts cumulate, mostly halite, but some brine transfer to the Salar de Aguas Calientes-3 cannot be excluded. The hydrogeological behavior of Laguna Tuyajto constitutes a model to understand the functioning of many other similar basins in other areas in the Andean Altiplano.

  13. Imaging the mid-crustal low velocity zone of the Altiplano-Puna magma body (Uturuncu volcano) in southern Bolivia from receiver functions

    NASA Astrophysics Data System (ADS)

    Cooksey, S.; Christensen, D. H.; West, M. E.

    2012-12-01

    Uturuncu volcano is located in the Altiplano-Puna volcanic complex, near the center of the Altiplano-Puna magma body (APMB) in southern Bolivia. The region has exhibited sustained uplift of 1 to 2 cm/yr for several decades over a broad region (70 km diameter). Uturuncu volcano and the surrounding area are the focus of an intensive multi-university study. The centerpiece of this study is a 40-station network of broadband seismometers that were deployed in the spring of 2010. At this time two full years of data have been retrieved from the network. Over 1200 receiver functions were determined from 65 teleseismic earthquakes. Receiver functions from similar back-azimuths and distances were then stacked to produce 49 average receiver functions that are used in this study. P-wave receiver functions clearly delineate the low velocity region associated with the APMB. This mid-crustal low velocity zone is present throughout the study area. While the APMB has been previously noted and described, the current network increases the station density in this region by a factor of 10. The top of the low velocity layer is associated with a large negative Ps arrival at about 2 seconds, corresponding to a depth of about 15 km (although there is scatter and variability in the depth modeling). This negative arrival is followed by a positive Ps arrival at around 3.5 seconds corresponding to the bottom of the low velocity zone at a depth of about 25 km. In general the low velocity zone is around 10-15 km thick, but once again with a fair amount of variability. The low velocity region corresponds well with estimates of the inflation source responsible for the observed uplift, and thus most likely represents an extensive region of partial melt, and potentially magma recharge, at the volcano. Arrivals from the Moho and subducting Nazca plate are obscured by the strong arrivals (including multiple reverberations) from the low velocity layer.

  14. Groundwater flow in a closed basin with a saline shallow lake in a volcanic area: Laguna Tuyajto, northern Chilean Altiplano of the Andes.

    PubMed

    Herrera, Christian; Custodio, Emilio; Chong, Guillermo; Lambán, Luis Javier; Riquelme, Rodrigo; Wilke, Hans; Jódar, Jorge; Urrutia, Javier; Urqueta, Harry; Sarmiento, Alvaro; Gamboa, Carolina; Lictevout, Elisabeth

    2016-01-15

    Laguna Tuyajto is a small, shallow saline water lake in the Andean Altiplano of northern Chile. In the eastern side it is fed by springs that discharge groundwater of the nearby volcanic aquifers. The area is arid: rainfall does not exceed 200mm/year in the rainiest parts. The stable isotopic content of spring water shows that the recharge is originated mainly from winter rain, snow melt, and to a lesser extent from some short and intense sporadic rainfall events. Most of the spring water outflowing in the northern side of Laguna Tuyajto is recharged in the Tuyajto volcano. Most of the spring water in the eastern side and groundwater are recharged at higher elevations, in the rims of the nearby endorheic basins of Pampa Colorada and Pampa Las Tecas to the East. The presence of tritium in some deep wells in Pampa Colorada and Pampa Las Tecas indicates recent recharge. Gas emission in recent volcanoes increase the sulfate content of atmospheric deposition and this is reflected in local groundwater. The chemical composition and concentration of spring waters are the result of meteoric water evapo-concentration, water-rock interaction, and mainly the dissolution of old and buried evaporitic deposits. Groundwater flow is mostly shallow due to a low permeability ignimbrite layer of regional extent, which also hinders brine spreading below and around the lake. High deep temperatures near the recent Tuyajto volcano explain the high dissolved silica contents and the δ(18)O shift to heavier values found in some of the spring waters. Laguna Tuyajto is a terminal lake where salts cumulate, mostly halite, but some brine transfer to the Salar de Aguas Calientes-3 cannot be excluded. The hydrogeological behavior of Laguna Tuyajto constitutes a model to understand the functioning of many other similar basins in other areas in the Andean Altiplano. PMID:26410705

  15. What is safe and clean water in rural Bolivian communities? A preliminary investigation of heavy metal contamination in rural community water systems in the Bolivian Altiplano

    NASA Astrophysics Data System (ADS)

    Borella, M.; Guido, Z.; Borella, P.; Ketron, T.

    2009-12-01

    A proliferation of potable water systems utilizing groundwater is currently underway in the Lake Titicaca region of the Bolivian Altiplano. With the aid of national and international organizations, rural communities are developing groundwater sources because the region’s surface water is highly contaminated with waterborne pathogens—the primary factor contributing to high child mortality rates in developing nations. According to UNICEF, 86 percent of Bolivian families have access to “improved” water systems, which predominantly take the form of deep groundwater wells or contained natural springs. While the water systems have worked well to reduce pathogens in drinking water systems that cause illnesses such as dysentery, the water is rarely tested for heavy metal contamination, such as arsenic and lead. While bacteria analysis is essential, it is not the only component of healthy drinking water. Testing for heavy metals is especially important in the Bolivian Altiplano because abundant volcanic deposits and massive sulfide deposits suggest that in some areas it is likely that the water contains elevated concentrations of heavy metals. In this study, Terra Resource Development International, A California-based 502(c)3 nonprofit organization, partnered with Stanford University, the Technical University of Bolivia, and the Bolivian Geologic and Mining Survey to collect water samples in 36 rural community situated in four watersheds feeding into Lake Titicaca. Water was collected from shallow, hand dug wells, deep groundwater wells, springs, and small rivers in the Tiwanku, Laja, Batallas, Achacachi watersheds and were analyzed for inorganic contaminants. Samples were analyzed at Stanford’s Environmental Measurements Facility using the Inductively Coupled Plasma (ICP) Spectrometer for major ions and heavy metals. Results will help determine which, if any, community water systems are at risk of heavy metal contamination, where more comprehensive sampling is

  16. Geochemical processes controlling mobilization of arsenic and trace elements in shallow aquifers and surface waters in the Antequera and Poopó mining regions, Bolivian Altiplano

    NASA Astrophysics Data System (ADS)

    Ramos Ramos, Oswaldo Eduardo; Rötting, Tobias S.; French, Megan; Sracek, Ondra; Bundschuh, Jochen; Quintanilla, Jorge; Bhattacharya, Prosun

    2014-10-01

    A geochemical approach was applied to understand the factors controlling the mobilization of As and trace elements (TEs) in mining areas of the Poopó and Antequera River sub-basins on the Bolivian Altiplano. A total of 52 samples (surface, groundwater and geothermal water) were collected during the rainy season (2009). Arsenic, Cd and Mn concentrations exceed World Health Organization (WHO) drinking water guidelines and Bolivian regulations for drinking water in 28 groundwater samples, but Cu, Ni, Pb and Zn do not. Arsenic, Cd, Mn, Pb and Zn concentrations exceed World Health Organization guidelines for drinking water and Bolivian regulations Class A standard for discharge to water bodies in 20 surface water samples, whereas levels of Cu do not, and Ni and Fe rarely exceed regulation and guideline values. Factor analysis was applied to 18 hydrochemical parameters of 52 samples. Five factors for groundwater (plagioclase weathering, dissolution of gypsum and halite, TEs mobilization at acidic pH, sulfide oxidation, and release of As) account for 86.5% of the total variance for Antequera and 83.9% for Poopó sub-basins. Four factors for surface water data (weathering and mobilization of TEs influenced by pH, dissolution of evaporate salts, neutralization of acid mine drainage, and As release due to dissolution of Mn and Fe oxides) account for 91% of the total variance in Antequera and 96% in Poopó sub-basins. The As and TEs mobilized in these regions could affect the local water sources, which is a prevalent concern with respect to water resource management in this semi-arid Altiplano region. Presence of both natural and anthropogenic sources of contamination requires careful monitoring of water quality.

  17. AirMSPI PODEX Big Sur Ellipsoid Images

    Atmospheric Science Data Center

    2013-12-11

    ... AirMSPI Browse Images from the PODEX 2013 Campaign   Big Sur target 02/03/2013 Ellipsoid-projected   Select ...   Version number   For more information, see the  Data Product Specifications (DPS) ...

  18. Lignes directrices canadiennes sur la rhinosinusite chronique

    PubMed Central

    Kaplan, Alan

    2013-01-01

    Résumé Objectif Présenter un résumé clinique des lignes directrices canadiennes sur la rhinosinusite chronique (RSC) qui comporte des recommandations pertinentes aux médecins de famille. Qualité des données Les auteurs des lignes directrices ont effectué une recherche documentaire systématique dans la littérature médicale et ont rédigé une ébauche de recommandations. Une cote a été donnée à la fois en fonction de la fiabilité des données probantes et de la solidité des recommandations. On a sollicité les commentaires d’experts en contenu de l’extérieur, ainsi que l’aval des sociétés médicales (Association pour la microbiologie médicale et l’infectiologie Canada, Société canadienne d’allergie et d’immunologie clinique, Canadian Society of Otolaryngology—Head and Neck Surgery, Association canadienne des médecins d’urgence et Regroupement canadien des médecins de famille en santé respiratoire). Message principal Le diagnostic d’une RSC se fonde sur le type et la durée des symptômes et une constatation objective d’une inflammation de la muqueuse nasale ou des sinus paranasaux. La rhinosinusite chronique est catégorisée en fonction de la présence ou de l’absence de polypes nasaux et cette distinction entraîne des différences dans le traitement. On traite la rhinosinusite chronique avec polypes nasaux au moyen de corticostéroïdes par voie intranasale. Des antibiotiques sont recommandés quand les symptômes indiquent une infection (douleur ou purulence). Pour une RSC sans polypes nasaux, on recommande des corticostéroïdes par voie intranasale et des antibiotiques de deuxième ligne (par ex. combinaisons amoxicilline–acide clavulanique ou fluoroquinolones à activité accrue contre Gram positif). Une irrigation avec une solution saline, des stéroïdes par voie orale et des tests d’allergies pourraient être appropriées. Si le patient ne répond pas au traitement, il faudrait envisager d

  19. Fires Burning near Big Sur, California

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Fires near Big Sur, Calif., continued to burn unchecked when the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra satellite captured this image on Sunday, June 29. In Northern California alone, fires have consumed more than 346,000 acres.At least 18,000 people have deployed to attempt to extinguish or control the flames. Air quality as far away as San Francisco has been adversely impacted by the dense clouds of smoke and ash blowing towards the northwest. The satellite image combines a natural color portrayal of the landscape with thermal infrared data showing the active burning areas in red. The dark area in the lower right is a previous forest fire.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

    Size: 35.4 by 57 kilometers (21.9 by 34.2 miles) Location: 36.1 degrees North latitude, 121.6 degrees West longitude Orientation: North at top Image Data: ASTER bands 3, 2, and 1 Original Data Resolution: 15 meters (49 feet) Dates Acquired: June 29

  20. Kir6.2 activation by sulfonylurea receptors: a different mechanism of action for SUR1 and SUR2A subunits via the same residues

    PubMed Central

    Principalli, Maria A; Dupuis, Julien P; Moreau, Christophe J; Vivaudou, Michel; Revilloud, Jean

    2015-01-01

    ATP-sensitive potassium channels (K-ATP channels) play a key role in adjusting the membrane potential to the metabolic state of cells. They result from the unique combination of two proteins: the sulfonylurea receptor (SUR), an ATP-binding cassette (ABC) protein, and the inward rectifier K+ channel Kir6.2. Both subunits associate to form a heterooctamer (4 SUR/4 Kir6.2). SUR modulates channel gating in response to the binding of nucleotides or drugs and Kir6.2 conducts potassium ions. The activity of K-ATP channels varies with their localization. In pancreatic β-cells, SUR1/Kir6.2 channels are partly active at rest while in cardiomyocytes SUR2A/Kir6.2 channels are mostly closed. This divergence of function could be related to differences in the interaction of SUR1 and SUR2A with Kir6.2. Three residues (E1305, I1310, L1313) located in the linker region between transmembrane domain 2 and nucleotide-binding domain 2 of SUR2A were previously found to be involved in the activation pathway linking binding of openers onto SUR2A and channel opening. To determine the role of the equivalent residues in the SUR1 isoform, we designed chimeras between SUR1 and the ABC transporter multidrug resistance-associated protein 1 (MRP1), and used patch clamp recordings on Xenopus oocytes to assess the functionality of SUR1/MRP1 chimeric K-ATP channels. Our results reveal that the same residues in SUR1 and SUR2A are involved in the functional association with Kir6.2, but they display unexpected side-chain specificities which could account for the contrasted properties of pancreatic and cardiac K-ATP channels. PMID:26416970

  1. Random assembly of SUR subunits in K(ATP) channel complexes.

    PubMed

    Cheng, Wayland W L; Tong, Ailing; Flagg, Thomas P; Nichols, Colin G

    2008-01-01

    Sulfonylurea receptors (SURs) associate with Kir6.x subunits to form tetradimeric K(ATP) channel complexes. SUR1 and SUR2 confer differential channel sensitivities to nucleotides and pharmacological agents, and are expressed in specific, but overlapping, tissues. This raises the question of whether these different SUR subtypes can assemble in the same channel complex and generate channels with hybrid properties. To test this, we engineered dimeric constructs of wild type or N160D mutant Kir6.2 fused to SUR1 or SUR2A. Dimeric fusions formed functional, ATP-sensitive, channels. Coexpression of weakly rectifying SUR1-Kir6.2 (WTF-1) with strongly rectifying SUR1-Kir6.2[N160D] (NDF-1) in COSm6 cells results in mixed subunit complexes that exhibit unique rectification properties. Coexpression of NDF-1 and SUR2A-Kir6.2 (WTF-2) results in similar complex rectification, reflecting the presence of SUR1- and SUR2A-containing dimers in the same channel. The data demonstrate clearly that SUR1 and SUR2A subunits associate randomly, and suggest that heteromeric channels will occur in native tissues. PMID:18690055

  2. Climate and tectonic evolution of the Descanso-Yauri basin in the northernmost Altiplano: Archetype example of a 'lithospheric drip' basin

    NASA Astrophysics Data System (ADS)

    Kar, N.; Garzione, C. N.

    2015-12-01

    We present a new multiproxy Miocene-Pliocene paleoelevation record of the northernmost Altiplano plateau reconstructed from pollen, clumped isotope (TΔ47) and δ18Oc of sedimentary carbonates and leaf wax n-alkane δD signatures. The ~18Ma to ~9Ma deposits of our study area, Descanso-Yauri basin in southern Peru show 11 to 16ºC warmer than modern mean annual air temperature, low elevation vegetation pollen assemblage (dominated by Podocarpus), and an average precipitation δ18Omw (VSMOW) value of -8.3±2.0‰ (2σ). The ~5 to 4 Ma deposits in the Descanso-Yauri basin are characterized by herb and shrub vegetation and an average δ18O mw (VSMOW) value of -14.6±3.0‰ (2σ), indicative of an elevation and/or climate similar to modern conditions. Based on the multiproxy paleoclimate record, we interpret that there was a 2±1 km surface uplift between 9 and 5 Ma in the northernmost Altiplano plateau. Deformation history analysis through map scale structural investigation combined with provenance analysis from conglomerate clast composition and paleocurrents show that the thrusts bounding the NE side of the Descanso-Yauri basin were active until ˜9Ma. Deformation waned afterwards, and switched to an extensional deformation regime, coincident with decrease in subsidence rate from ˜0.2mm/year to ˜0.03mm/year. Depositional history reconstructed by facies analysis and stratigraphic correlation reveal that deposition in the basin began with transverse braided river systems that formed along the thrust front and gave way to a larger fluvial-lacustrine system until ˜4 Ma. The basin deposits show an overall fining upward trend from coarse clastic dominated, in the lower most parts of the basin fill to fluvial overbank and lacustrine mudstone and diatomite deposits in the middle-upper parts. The thickest deposits formed in the central part of the basin. Based on these depositional and deformational patterns, we infer that the Descanso-Yauri basin formed in response to a

  3. Comparative infectivity of Fasciola hepatica metacercariae from isolates of the main and secondary reservoir animal host species in the Bolivian Altiplano high human endemic region.

    PubMed

    Valero, M A; Mas-Coma, S

    2000-01-01

    Fascioliasis due to Fasciola hepatica (Linnaeus, 1758) is an endemic disease on the Northern Bolivian Altiplano, where human prevalences and intensities are the highest known, sheep and cattle are the main reservoir hosts, and pigs and donkeys the secondary ones. Investigations were carried out to study the viability of metacercariae experimentally obtained from eggs shed by naturally infected Altiplanic sheep, cattle, pigs and donkeys. A total of 157 Wistar rats were infected with doses of 5, 10, 20 and 150 metacercariae. Metacercariae aged for different number of weeks were used to analyse the influence of age on their viability. The number of worms successfully developed in each rat was established by dissection. Results obtained show that metacercarial infectivity is dependent upon storage time, being lower when metacercariae are older. The maximum longevity is 31 weeks using doses of 20 metacercariae per rat and 48 weeks with 150 metacercariae per rat, although in the latter case only a very low percentage of worms is recovered. Age-related infectivity of metacercariae from Altiplanic F. hepatica does not significantly differ from that of the liver fluke in lowlands of other countries. Concerning the influence of the isolate according to host species, results indicate that metacercarial viabilities of pig and donkey isolates are similar to the viabilities of metacercariae of sheep and cattle isolates. Thus, pig and donkey have a high transmission potential capacity concerning this aspect. This fact is of great importance for the control of human and animal fascioliasis in this highly endemic zone.

  4. Progressive glacial retreat in the Southern Altiplano (Uturuncu volcano, 22°S) between 65 and 14 ka constrained by cosmogenic 3He dating

    NASA Astrophysics Data System (ADS)

    Blard, Pierre-Henri; Lave, Jérôme; Farley, Kenneth A.; Ramirez, Victor; Jimenez, Nestor; Martin, Léo C. P.; Charreau, Julien; Tibari, Bouchaïb; Fornari, Michel

    2014-07-01

    This work presents the first reconstruction of late Pleistocene glacier fluctuations on Uturuncu volcano, in the Southern Tropical Andes. Cosmogenic 3He dating of glacial landforms provides constraints on ancient glacier position between 65 and 14 ka. Despite important scatter in the exposure ages on the oldest moraines, probably resulting from pre-exposure, these 3He data constrain the timing of the moraine deposits and subsequent glacier recessions: the Uturuncu glacier may have reached its maximum extent much before the global LGM, maybe as early as 65 ka, with an equilibrium line altitude (ELA) at 5280 m. Then, the glacier remained close to its maximum position, with a main stillstand identified around 40 ka, and another one between 35 and 17 ka, followed by a limited recession at 17 ka. Then, another glacial stillstand is identified upstream during the late glacial period, probably between 16 and 14 ka, with an ELA standing at 5350 m. This stillstand is synchronous with the paleolake Tauca highstand. This result indicates that this regionally wet and cold episode, during the Heinrich 1 event, also impacted the Southern Altiplano. The ELA rose above 5450 m after 14 ka, synchronously with the Bolling-Allerod.

  5. Evidence of Early to Middle Ordovician arc volcanism in the Cordillera Oriental and Altiplano of southern Peru, Ollantaytambo Formation and Umachiri beds

    NASA Astrophysics Data System (ADS)

    Bahlburg, Heinrich; Carlotto, Victor; Cárdenas, José

    2006-11-01

    Volcanic rocks of intermediate to predominantly mafic composition are exposed in the Cordillera Oriental and Altiplano of southern Peru in two localities: (1) the Ollantaytambo Formation, which crops out near Cusco, and (2) the Umachiri beds in the Departamento de Puno. The most notable unit in the Ollantaytambo Formation is an approximately 100 m thick succession of lapilli tuffs that originated by hydroclastic fragmentation. These volcanic rocks are of calc-alkaline basaltic to andesitic composition. The tuffs are overlain by fine-grained volcaniclastic sandstones and shales, which grade into quartz-rich turbidites. The Umachiri beds consist of monomict lapilli tuffs with varying lapilli abundance and size, formed by hydroclastic fragmentation, and volcaniclastic sandstones. The rocks have a uniform basaltic andesite composition and tholeiitic affinity. Chondrite-normalized element patterns of both volcanigenic units show a moderate enrichment of LREE and a weak negative Eu anomaly. Pronounced negative Nb and Ta anomalies indicate magma evolution in an arc environment. In contrast, the overlying epiclastic sandstones and shales in the Ollantaytambo Formation reflect upper crustal sources. Our data indicate that the deposition of the lapilli tuffs of the Ollantaytambo Formation and Umachiri beds likely was connected to the westward-lying Ordovician magmatic arc on the Arequipa Massif. If the Ordovician active margin in southern Peru had the same east-dipping subduction polarity as the active Gondwana margin in Argentina and Chile, the sedimentary basin in which the Ollantaytambo Formation and Umachiri beds were deposited was in a backarc position.

  6. Finding the SurPriSe: A Case Study of a Faculty Learning Community

    ERIC Educational Resources Information Center

    Michel, Roberta M.

    2014-01-01

    This article details a faculty learning community (FLC) that started in 2009 on the campus of a Midwestern University and has evolved into an interdisciplinary research, teaching and social community of practice and learning called SurPriSe. SurPriSe is an acronym that reflects the interest area of the FLC; Sur for surveillance, Pri for privacy,…

  7. Ground/satellite observations and atmospheric modeling of dust storms originating in the high Puna-Altiplano deserts (South America): Implications for the interpretation of paleo-climatic archives

    NASA Astrophysics Data System (ADS)

    Gaiero, D. M.; Simonella, L.; Gassó, S.; Gili, S.; Stein, A. F.; Sosa, P.; Becchio, R.; Arce, J.; Marelli, H.

    2013-05-01

    This study provides a detailed description of the sources, transport, dispersion, and deposition of two major dust events originating from the high-altitude subtropical Puna-Altiplano Plateau (15-26°S; 65-69°W) in South America. A long and severe drought provided the right conditions for the onset of both events in July 2009 and 2010. Dust was transported SE and deposited over the Pampas region and was observed to continue to the Atlantic Ocean. Dust monitoring stations located downwind recorded both events, and samples were characterized through chemical and textural analysis. Through a combination of meteorological data and satellite observations (CALIPSO and MODIS detectors), we estimate the emission flux for the 2010 event. This estimate was used to constrain the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) transport model and simulate the dust event. Both satellite imagery and model results agree in the location and extension of the dust cloud. CALIPSO detected dust between ~6000 and ~8500 m a.s.l., which remained at this height during most of its trajectory. The dust cloud mixed with a strong convective system in the region, and the associated precipitation brought down significant amounts of dust to the ground. Dust particle size analysis for both events indicates that near the sources dust samples show median modes of 12.4-14.1 µm, similar to modes observed 1300 km away. Chemical composition of sediments from potential dust sources shows distinct signatures within the Puna-Altiplano Plateau, the Puna sector being clearly different from the Altiplano area. In addition, both sources are markedly different from the Patagonian chemical fingerprint. These results have important implications to improve the interpretation of paleo-environmental archives preserved on the Argentine loess, Antarctic ice cores, and Southern Ocean marine sediments.

  8. Le point sur les amas de galaxies

    NASA Astrophysics Data System (ADS)

    Pierre, M.

    galaxies jouent donc un rôle de premier plan dans toute étude cosmologique et par conséquent, sont indispensables à notre compréhension globale de l'univers. Dans l'introduction générale, nous détaillons cet aspect fondamental en montrant comment l'étude des amas peut contribuer à contraindre les scénarios cosmologiques. Une fois le contexte scientifique délimité, les chapitres suivants s'attachent à présenter les diverses propriétés des amas et leur évolution cosmique observée dans diverses longueurs d'onde principalement dans les domaines visible (galaxies), X (gaz) et radio (gaz et particules). Nous verrons que l'étude détaillée d'un amas implique celle de l'interaction entre ses différentes composantes et est un passage obligé pour remonter au paramètre ultime (ou premier) qu'est sa masse. Loin d'être un détour ennuyeux, ceci sera l'occasion d'aborder des phénomènes physiques extrêmement variés tel l'aspect multi-phases du milieu intra-amas, les sursauts de formation d'étoiles et l'évolution morphologique des galaxies capturées par les amas, ou bien encore, l'interaction entre le plasma intra-amas et les particules relativistes accélérées lors de la fusion entre deux amas. Bien sûr, pour chaque longueur d'onde, nous ne manquerons pas de décrire simplement les techniques d'observation et d'analyse mises en oeuvre ; celles-ci sont particulièrement intéressantes dans le cas de l'instrumentation spatiale. Nous terminerons en présentant des projets d'observatoires pour l'horizon 2010 et leur impact prévu sur l'étude des amas de galaxies.

  9. Influence of source distribution and geochemical composition of aerosols on children exposure in the large polymetallic mining region of the Bolivian Altiplano.

    PubMed

    Goix, Sylvaine; Point, David; Oliva, Priscia; Polve, Mireille; Duprey, Jean Louis; Mazurek, Hubert; Guislain, Ludivine; Huayta, Carlos; Barbieri, Flavia L; Gardon, Jacques

    2011-12-15

    The Bolivian Altiplano (Highlands) region is subject to intense mining, tailing and smelting activities since centuries because of the presence of large and unique polymetallic ore deposits (Ag, Au, Cu, Pb, Sn, Sb, Zn). A large scale PM(10), PM(2.5) aerosol monitoring survey was conducted during the dry season in one of the largest mining cities of this region (Oruro, 200,000 inhabitants). Aerosol fractions, source distribution and transport were investigated for 23 elements at approximately 1 km(2) scale resolution, and compared to children exposure data obtained within the same geographical space. As, Cd, Pb, Sb, W and Zn in aerosols are present at relatively high concentrations when compared to studies from other mining regions. Arsenic exceeds the European council PM(10) guide value (6 ng/m(3)) for 90% of the samples, topping 200 ng/m(3). Ag, As, Cd, Cu, Pb and Sb are present at significantly higher levels in the district located in the vicinity of the smelter zone. At the city level, principal component analysis combined with the mapping of factor scores allowed the identification and deconvolution of four individual sources: i) a natural magmatic source (Co, Cs, Fe, K, Mn, Na, Rb and U) originating from soil dust, resuspended by the traffic activity; ii) a natural sedimentary source (Mg, Ca, Sr, Ba and Th) resulting from the suspension of evaporative salt deposits located South; iii) an anthropogenic source specifically enriched in mined elements (As, Cd, Cu, Pb, Sb and Zn) mainly in the smelting district of the city; and iv) a Ni-Cr source homogenously distributed between the different city districts. Enrichment factors for As, Cd and Sb clearly show the impact of smelting activities, particularly in the finest PM(2.5) fraction. Comparison to children's hair metal contents collected in five schools from different districts shows a direct exposure to smelting activity fingerprinted by a unique trace elements pattern (Ag, As, Cu, Pb, Sb).

  10. Isolation and characterization of a novel Acidithiobacillus ferrivorans strain from the Chilean Altiplano: attachment and biofilm formation on pyrite at low temperature.

    PubMed

    Barahona, Sergio; Dorador, Cristina; Zhang, Ruiyong; Aguilar, Pablo; Sand, Wolfgang; Vera, Mario; Remonsellez, Francisco

    2014-11-01

    Microorganisms are used to aid the extraction of valuable metals from low-grade sulfide ores in mines worldwide, but relatively little is known about this process in cold environments. This study comprises a preliminary analysis of the bacterial diversity of the polyextremophilic acid River Aroma located in the Chilean Altiplano, and revealed that Betaproteobacteria was the most dominant bacterial group (Gallionella-like and Thiobacillus-like). Taxa characteristic of leaching environments, such Acidithiobacillus and Leptospirillum, were detected at low abundances. Also, bacteria not associated with extremely acidic, metal-rich environments were found. After enrichment in iron- and sulfur-oxidizing media, we isolated and identified a novel psychrotolerant Acidithiobacillus ferrivorans strain ACH. This strain can grow using ferrous iron, sulfur, thiosulfate, tetrathionate and pyrite, as energy sources. Optimal growth was observed in the presence of pyrite, where cultures reached a cell number of 6.5 · 10(7) cells mL(-1). Planktonic cells grown with pyrite showed the presence of extracellular polymeric substances (10 °C and 28 °C), and a high density of cells attached to pyrite grains were observed at 10 °C by electron microscopy. The attachment of cells to pyrite coupons and the presence of capsular polysaccharides were visualized by using epifluorescence microscopy, through nucleic acid and lectin staining with Syto(®)9 and TRITC-Con A, respectively. Interestingly, we observed high cell adhesion including the formation of microcolonies within 21 days of incubation at 4 °C, which was correlated with a clear induction of capsular polysaccharides production. Our data suggests that attachment to pyrite is not temperature-dependent in At. ferrivorans ACH. The results of this study highlight the potential of this novel psychrotolerant strain in oxidation and attachment to minerals under low-temperature conditions.

  11. mtDNA and Y-chromosome diversity in Aymaras and Quechuas from Bolivia: different stories and special genetic traits of the Andean Altiplano populations.

    PubMed

    Gayà-Vidal, Magdalena; Moral, Pedro; Saenz-Ruales, Nancy; Gerbault, Pascale; Tonasso, Laure; Villena, Mercedes; Vasquez, René; Bravi, Claudio M; Dugoujon, Jean-Michel

    2011-06-01

    Two Bolivian samples belonging to the two main Andean linguistic groups (Aymaras and Quechuas) were studied for mtDNA and Y-chromosome uniparental markers to evaluate sex-specific differences and give new insights into the demographic processes of the Andean region. mtDNA-coding polymorphisms, HVI-HVII control regions, 17 Y-STRs, and three SNPs were typed in two well-defined populations with adequate size samples. The two Bolivian samples showed more genetic differences for the mtDNA than for the Y-chromosome. For the mtDNA, 81% of Aymaras and 61% of Quechuas presented haplogroup B2. Native American Y-chromosomes were found in 97% of Aymaras (89% hg Q1a3a and 11% hg Q1a3*) and 78% of Quechuas (100% hg Q1a3a). Our data revealed high diversity values in the two populations, in agreement with other Andean studies. The comparisons with the available literature for both sets of markers indicated that the central Andean area is relatively homogeneous. For mtDNA, the Aymaras seemed to have been more isolated throughout time, maintaining their genetic characteristics, while the Quechuas have been more permeable to the incorporation of female foreigners and Peruvian influences. On the other hand, male mobility would have been widespread across the Andean region according to the homogeneity found in the area. Particular genetic characteristics presented by both samples support a past common origin of the Altiplano populations in the ancient Aymara territory, with independent, although related histories, with Peruvian (Quechuas) populations.

  12. Etude des effets du martelage repetitif sur les contraintes residuelles

    NASA Astrophysics Data System (ADS)

    Hacini, Lyes

    L'assemblage par soudage peut engendrer des contraintes residuelles. Ces contraintes provoquent des fissurations prematurees et un raccourcissement de la duree de vie des composants. Dans ce contexte, le martelage robotise est utilise pour relaxer ces contraintes residuelles. Trois volets sont presentes: le premier est l'evaluation des effets des impacts unitaires repetes sur le champ de contraintes developpe dans des plaques d'acier inoxydable austenitique 304L vierges ou contenant des contraintes residuelles initiales. Dans la deuxieme partie de ce projet, le martelage est applique grace au robot SCOMPI. Les contraintes residuelles induites et relaxees par martelage sont ensuite mesurees par la methode des contours, qui a ete adaptee a cet effet. Dans la troisieme partie, le martelage est modelise par la methode des elements finis. Un modele axisymetrique developpe grace au logiciel ANSYS permet de simuler des impacts repetes d'un marteau elastique sur une plaque ayant un comportement elastoplastique.

  13. Effets des electrons secondaires sur l'ADN

    NASA Astrophysics Data System (ADS)

    Boudaiffa, Badia

    Les interactions des electrons de basse energie (EBE) representent un element important en sciences des radiations, particulierement, les sequences se produisant immediatement apres l'interaction de la radiation ionisante avec le milieu biologique. Il est bien connu que lorsque ces radiations deposent leur energie dans la cellule, elles produisent un grand nombre d'electrons secondaires (4 x 104/MeV), qui sont crees le long de la trace avec des energies cinetiques initiales bien inferieures a 20 eV. Cependant, il n'y a jamais eu de mesures directes demontrant l'interaction de ces electrons de tres basse energie avec l'ADN, du principalement aux difficultes experimentales imposees par la complexite du milieu biologique. Dans notre laboratoire, les dernieres annees ont ete consacrees a l'etude des phenomenes fondamentaux induits par impact des EBE sur differentes molecules simples (e.g., N2, CO, O2, H2O, NO, C2H 4, C6H6, C2H12) et quelques molecules complexes dans leur phase solide. D'autres travaux effectues recemment sur des bases de l'ADN et des oligonucleotides ont montre que les EBE produisent des bris moleculaires sur les biomolecules. Ces travaux nous ont permis d'elaborer des techniques pour mettre en evidence et comprendre les interactions fondamentales des EBE avec des molecules d'interet biologique, afin d'atteindre notre objectif majeur d'etudier l'effet direct de ces particules sur la molecule d'ADN. Les techniques de sciences des surfaces developpees et utilisees dans les etudes precitees peuvent etre etendues et combinees avec des methodes classiques de biologie pour etudier les dommages de l'ADN induits par l'impact des EBE. Nos experiences ont montre l'efficacite des electrons de 3--20 eV a induire des coupures simple et double brins dans l'ADN. Pour des energies inferieures a 15 eV, ces coupures sont induites par la localisation temporaire d'un electron sur une unite moleculaire de l'ADN, ce qui engendre la formation d'un ion negatif transitoire

  14. Avulsion processes at the terminus of low-gradient semi-arid fluvial systems: Lessons from the Río Colorado, Altiplano endorheic basin, Bolivia

    NASA Astrophysics Data System (ADS)

    Donselaar, M. E.; Cuevas Gozalo, M. C.; Moyano, S.

    2013-01-01

    The Río Colorado dryland river system in the southeast of the endorheic Altiplano Basin (Bolivia) terminates on a very flat coastal plain at the edge of the Salar de Uyuni, the world's largest salt pan with an area of ca. 12,500 km2. Since the Pleistocene the basin has experienced several lake expansion and contraction cycles in response to wetter and drier climate periods, respectively. At present the basin is in a dry climate period which results in a lake level lowstand and progradation of fluvial systems such as the Río Colorado onto the former lake bottom. The present field study of the terminus of the Río Colorado shows that the river experiences a gradual downstream decrease of bankfull width and depth. This bankfull decrease is caused by the combined effects of: (1) extremely low gradient of the lake bottom and, hence, loss of flow energy, and (2) downstream transmission losses due to high evaporation potential and river water percolation through the channel floor. Peak water discharge in seasonal, short-duration rain periods causes massive overbank flooding and floodplain inundation. On satellite images the morphology of the river terminus has a divergent pattern and resembles a network of coeval sinuous distributary channels. However, field observations show that only one channel is active at low flow stage, and at high-flow stage an abandoned, partially infilled channel may be active as well. The active channel at its termination splits into narrow and shallow anastomosing streams before its demise on the lacustrine coastal plain. The rest of the channels which form the divergent network are older sediment-filled abandoned sinuous river courses with multiple random avulsion points. These channel deposits, together with extensive amalgamated crevasse-splay deposits, form an intricate network of fluvial sand deposits. Successive stages of progressively deeper crevasse-channel incision into the floodplain are the result of waning-stage return flow of

  15. Identification of the Calderas for Major Ignimbrites of the Altiplano-Puna Volcanic Complex, Central Andes, Including Two New Super-eruptions

    NASA Astrophysics Data System (ADS)

    Ort, M. H.; de Silva, S. L.; Jiménez, N.

    2008-12-01

    The Neogene ignimbrite flare-up in the Altiplano-Puna Volcanic Complex (APVC) in the central Andes produced calderas and ignimbrites covering >70,000 km2 in Chile, Bolivia, and Argentina and totaling >11,000 km3 of magma. One of the questions related to this extraordinary occurrence is how long it took for these ignimbrites to be emplaced. In an effort to determine this, we have combined field correlations, high-precision 40Ar/39Ar dating, anisotropy of magnetic susceptibility (AMS) and characteristic remanent magnetism (ChRM) to constrain the dates of the eruptions. Herein we present the paleomagnetic data and preliminary interpretations, including the definition of two new super-eruptions in the APVC (including the youngest yet identified in the APVC). Several ignimbrites occupy similar stratigraphic positions. The Pastos Grandes and Tara Ignimbrites erupted 2.8-3.5 Ma, while the Chuhuilla, Alota, and Guacha Ignimbrites date between 5.3 and 5.6 Ma. The Pastos Grandes and Tara Ignimbrites have similar ChRM directions. The ChRM directions of the Alota and Guacha Ignimbrites are clearly distinct but the Chuhuilla Ignimbrite data have very large dispersion. The thermal demagnetization reveals a single component in nearly all the samples, which may indicate that the ignimbrites were emplaced above the magnetite Curie temperature. Current efforts center on refining and reducing the errors on the ChRM directions. AMS was used to determine flow directions and thus define the source areas for ignimbrites. The 3.51 Ma Tara Ignimbrite, first recognized as ponded ignimbrite in La Pacana caldera and thought to be erupted from there, is sourced in the Guacha caldera of Bolivia, likely from the western dome complex, which yields similar dates. Great thicknesses of Tara Ignimbrite are ponded within the Guacha caldera, and also around Cerro Zapaleri. This is the youngest super-eruption in the central APVC. The Pastos Grandes caldera was previously thought to have formed during

  16. The Cerro Guacha Caldera complex: An Upper Miocene-Pliocene polycyclic volcano-tectonic structure in the Altiplano Puna Volcanic Complex of the Central Andes of Bolivia

    NASA Astrophysics Data System (ADS)

    Iriarte, R.; de Silva, S. L.; Jimenez, N.; Ort, M. H.

    2011-12-01

    Four multicyclic complex calderas and smaller ignimbrite shields located within the Altiplano Puna Volcanic Complex of the Central Andes erupted 13000 km3 of magma within the last 11 Ma. One of the largest and most complex of these is the 5.6 to 1 Ma Cerro Guacha Caldera complex in SW Lipez, Bolivia. Ar-Ar age determinations and paleomagnetic signatures suggest that the Cerro Guacha Caldera was formed by two major eruptions, caldera collapse, resurgence cycles and several smaller eruptions. Two major ignimbrites of super-eruption magnitude are found with 40Ar-39Ar from biotites and sanidines of 5.65±0.01Ma for the 1300 km3 (magma volume) Guacha ignimbrite and 3.49±0.01Ma for the 800 km3 Tara Ignimbrite. The last major eruption occurred on the western flank producing the 1.72±0.02 Ma Puripica Chico Ignimbrite with a volume of approximately 10 km3. Characteristic remanent magnetization data (ChRM) for these ignimbrites show that the Guacha has reverse polarity, while the Tara is normally polarized and the magnetic fingerprints have allowed their current full extents to be identified. The Guacha ignimbrite extends over 70 km north and south of the caldera and is distributed over an area of almost 5000 km2. The Tara ignimbrite covers an area of almost 4000 km2 and extends southwards almost 70 km, where it ponded in La Pacana caldera. A conspicuous lineament of volcanic structures towards the caldera's easternmost edge, along with a flat surface (moat), welded ignimbrites, and sedimentary lacustrine sequences suggest an earlier 60x40 km outer collapse associated with the Guacha explosive episode. A central graben consisting of Guacha welded ignimbrite is related to the first episode of resurgence. Evidence of a second 30x15 km inner collapse scarp includes offset of welded Guacha ignimbrites and alignment of lava domes equivalent in age to the Tara ignimbrite. A second resurgence episode is suggested by the presence of a central block consisting primarily of welded

  17. Rapid tectonic and paleogeographic evolution associated with the development of the Chucal anticline and the Chucal-Lauca Basin in the Altiplano of Arica, northern Chile

    NASA Astrophysics Data System (ADS)

    Charrier, Reynaldo; Chávez, Alvaro N.; Elgueta, Sara; Hérail, Gérard; Flynn, John J.; Croft, Darin A.; Wyss, André R.; Riquelme, Rodrigo; García, Marcelo

    2005-05-01

    , which is intercalated within its middle part). We interpret the contractional deformation to be associated with tectonic activity that led to the uplift of the Altiplano; however, paleobotanical evidence does not indicate any major altitude changes during the time period considered here but rather suggests that rapid uplift took place after the deposition of the Quebrada Macusa Formation.

  18. Genesis and Eruptive Dynamics of the Garnet-Bearing Rhyolites from the Ramadas Volcanic Centre (Altiplano-Puna Plateau, Central Andes, Argentina).

    NASA Astrophysics Data System (ADS)

    De Astis, G.; Baez, W.; Bardelli, L.; Becchio, R.; Giordano, G.; Lucci, F.; Rossetti, F.; Viramonte, J. G.

    2015-12-01

    Ramadas volcanic centre (6.6 Ma) is a monogenetic calderic depression, now largely obliterated, almost coeval with the Late Miocene outbreak of highly explosive silicic activity in the Altiplano-Puna plateau. Ramadas erupted a rather complex suite of garnet-bearing, rhyolitic pyroclastic rocks, dominated by a >35 km3 fall deposit and preceded by the emplacement of a lag breccia containing abundant metasedimentary lithics and garnet-tourmaline leucogranites. During the waning stage of the eruption, small volume phreatomagmatic deposits formed a small tuff-ring, followed by a lava coulée emplacement. Volcanological data together with textural features of typical tube pumice evidence a volatiles-rich, plinian eruption. Petrographic and textural studies on juveniles confirm the presence of euhedral garnet as dominant phase and identify micrometric metaigneous fragments (Qtz+Bt+Kfs+Mt+Tur). BSE imaging and microprobe analyses on glasses, garnets and accessory mineral phases (zircon and monazite) provide further data to understand the genesis and eruptive conditions of these atypical rhyolites, geochemically different from those outcropping in the same region. Garnets display a homogeneous, unzoned almandine-spessartine composition (Alm72-71Sps24-23Pyr0-1Grs4-3) and are contained in a glassy rhyolitic magma with peraluminous character, HREE depleted and relative LREE enriched. It's known that primary igneous garnets are rare and can only develop under restricted conditions. Additionally, the presence of Zr and Mnz is associated with both magmatic and high-T metamorphic processes. Although more data need to be collected, our study and preliminary modelling point to the occurrence of thermal metamorphism shifting to partial melting of Fe-MnO-rich metapelitic rocks (or even re-melting of older acid volcanics), with final extraction of volatiles-rich rhyolitic melts, able to produce a plinian eruption. Here, Alm-Sps garnet could represent the peritectic product of the

  19. Endothelial SUR-8 Acts in an ERK-Independent Pathway During Atrioventricular Cushion Development

    PubMed Central

    Yi, Jing; Chen, Muyun; Wu, Xiaohui; Yang, Xiao; Xu, Tian; Zhuang, Yuan; Han, Min; Xu, Rener

    2010-01-01

    SUR-8, a conserved leucine-rich repeats protein, was first identified as a positive regulator of Ras pathway in Caenorhabditis elegans. Biochemical studies indicated that SUR-8 interacts with Ras and Raf, leading to the elevated ERK activity. However, the physiological role of SUR-8 during mammalian development remains unclear. Here we found that germline deletion of SUR-8 in mice resulted in early embryonic lethality. Inactivated SUR-8 specifically in mouse endothelial cells (ECs) revealed that SUR-8 is essential for embryonic heart development. SUR-8 deficiency in ECs resulted in late embryonic lethality, and the mutant mice displayed multiple cardiac defects. The reduced endothelial-mesenchymal transformation (EMT) and the reduced mesenchyme proliferation phase were observed in the atrioventricular canal (AVC) within the mutant hearts, leading to the formation of hypoplastic endocardial cushions. However, ERK activation did not appear to be affected in mutant ECs, suggesting that SUR-8 may act in an ERK-independent pathway to regulate AVC development. Developmental Dynamics 239:2005–2013, 2010 © 2010 Wiley-Liss, Inc. PMID:20549726

  20. Lignes directrices simplifiées sur les lipides

    PubMed Central

    Allan, G. Michael; Lindblad, Adrienne J.; Comeau, Ann; Coppola, John; Hudson, Brianne; Mannarino, Marco; McMinis, Cindy; Padwal, Raj; Schelstraete, Christine; Zarnke, Kelly; Garrison, Scott; Cotton, Candra; Korownyk, Christina; McCormack, James; Nickel, Sharon; Kolber, Michael R.

    2015-01-01

    Résumé Objectif Produire un guide de pratique clinique comportant une approche simplifiée à la prévention primaire des maladies cardiovasculaires (MCV), en insistant sur l’estimation du risque de MCV et la prise en charge des profils lipidiques à l’intention des cliniciens de soins primaires et leurs équipes; nous avons recherché la contribution de professionnels des soins primaires qui n’avaient que peu ou pas de conflits d’intérêts et nous nous sommes concentrés sur les données probantes de la plus haute qualité accessibles. Méthodes Neuf professionnels de la santé (4 médecins de famille, 2 internistes, 1 infirmière praticienne, 1 infirmière autorisée et 1 pharmacienne) et 1 membre non votant (pharmacienne gestionnaire de projet) formaient le comité principal appelé le Lipid Pathway Committee (le comité). La sélection des membres s’est fondée sur la profession, le milieu de pratique et son emplacement. Les membres ont divulgué tous leurs conflits d’intérêts potentiels ou réels. Le processus d’élaboration des lignes directrices était itératif et s’appuyait sur des affichages en ligne, une révision détaillée des données probantes, des réunions par téléphone et en ligne. Le comité a cerné 12 questions prioritaires à répondre. Le groupe de révision des données probantes a répondu à ces questions. À la suite d’un examen des réponses, les principales recommandations ont été formulées par consensus du comité. Nous avons produit une ébauche des lignes directrices qui a ensuite été peaufinée, distribuée à un groupe de cliniciens (médecins de famille, autres spécialistes, pharmaciens, infirmières et infirmières praticiennes) et à des patients pour obtenir de la rétroaction, la réviser en conséquence et le comité l’a ensuite finalisée. Recommandations Des recommandations sont présentées concernant le dépistage et les analyses, les évaluations du risque, le suivi, de même que le r

  1. Structure of thermotoga maritima stationary phase survival protein SurE : a novel acid phosphatase.

    SciTech Connect

    Zhang, R.-G; Skarina, T.; Katz, J. E.; Khachatryan, A; Vyas, S.; Arrowsmith, C. H.; Clarke, S.; Edwards, A.; Joachimiak, A.; Savchenko, A.; Biosciences Division; Univ. of Toronto; Univ. of California; Clinical Genomics Centre /Proteomics, Univ. Health Network

    2001-11-01

    Background: The rpoS, nlpD, pcm, and surE genes are among many whose expression is induced during the stationary phase of bacterial growth. rpoS codes for the stationary-phase RNA polymerase {sigma} subunit, and nlpD codes for a lipoprotein. The pcm gene product repairs damaged proteins by converting the atypical isoaspartyl residues back to L-aspartyls. The physiological and biochemical functions of surE are unknown, but its importance in stress is supported by the duplication of the surE gene in E. coli subjected to high-temperature growth. The pcm and surE genes are highly conserved in bacteria, archaea, and plants. Results: The structure of SurE from Thermotoga maritima was determined at 2.0 Angstroms. The SurE monomer is composed of two domains; a conserved N-terminal domain, a Rossman fold, and a C-terminal oligomerization domain, a new fold. Monomers form a dimer that assembles into a tetramer. Biochemical analysis suggests that SurE is an acid phosphatase, with an optimum pH of 5.5-6.2. The active site was identified in the N-terminal domain through analysis of conserved residues. Structure-based site-directed point mutations abolished phosphatase activity. T. maritima SurE intra- and intersubunit salt bridges were identified that may explain the SurE thermostability. Conclusions: The structure of SurE provided information about the protein's fold, oligomeric state, and active site. The protein possessed magnesium-dependent acid phosphatase activity, but the physiologically relevant substrate(s) remains to be identified. The importance of three of the assigned active site residues in catalysis was confirmed by site-directed mutagenesis.

  2. Comparison of 36Cl and 3He measurements in glacial surfaces on the tropical Altiplano (Cerro Tunupa volcano, 20°S)

    NASA Astrophysics Data System (ADS)

    Schimmelpfennig, Irene; Blard, Pierre-Henri; Lavé, Jérôme; Benedetti, Lucilla; Aster Team

    2016-04-01

    age is overestimated due to analytical complications. The results of this study show that combined 3He and 36Cl measurements are useful to detect geomorphological or analytical biases, and that they represent a high potential for the investigation of complex exposure histories in lithologies that lack quartz. Blard, P.-H., Lavé, J., Farley, K.A., Fornari, M., Jiménez, N., Ramirez, V., 2009. Late local glacial maximum in the Central Altiplano triggered by cold and locally-wet conditions during the paleolake Tauca episode (17-15 ka, Heinrich 1). Quat. Sci. Rev. 28, 3414-3427. Blard, P.-H., Lavé, J., Sylvestre, F., Placzek, C.J., Claude, C., Galy, V., Condom, T., Tibari, B., 2013. Cosmogenic 3He production rate in the high tropical Andes (3800 m, 20◦S): Implications for the local last glacial maximum. Earth Planet. Sci. Lett. 377-378, 260-275.

  3. Effusive silicic volcanism in the Central Andes: The Chao dacite and other young lavas of the Altiplano-Puna Volcanic Complex

    NASA Technical Reports Server (NTRS)

    De Silva, S. L.; Self, S.; Francis, P. W.; Drake, R. E.; Ramirez, Carlos R.

    1994-01-01

    The largest known Quaternary silicic lava body in the world is Cerro Chao in north Chile, a 14-km-long coulee with a volume of at least 26 cu km. It is the largest of a group of several closely similar dacitic lavas erupted during a recent (less than 100,000 year old) magmatic episode in the Altiplano-Puna Volcanic Complex (APVC; 21-24 deg S) of the Centra; Andean Volcanic Zone. The eruption of Chao proceeded in three phases. Phase 1 was explosive and produced approximately 1 cu km of coarse, nonwelded dacitic pumice deposits and later block and ash flows that form an apron in front of the main lava body. Phase 2 was dominantly effusive and erupted approximately 22.5 cu km of magma in the form of a composite coulee covering approximately 53 sq km with a 400-m-high flow front and a small cone of poorly expanded pumice around the vent. The lava is homogeneous with rare flow banding and vesicular tops and selvages. Ogives (flow ridges) reaching heights of 30 m form prominent features on its surface. Phase 3 produced a 6-km-long, 3-km-wide flow that emanated from a collapsed dome. Ogives are subdued, and the lava is glassier than that produced in previous phases. All the Chao products are crystal-rich high-K dacites and rhyodacites with phenocrysts of plagioclase, quartz, hornblende, biotite, sphene, rare snidine, and oxides. Phenocryst contents reach 40-60 vol % (vesicle free) in the main phase 2 lavas but are lower in the phase 1 (20-25%) and phase 3 (approximately 40%) lavas. Ovoid andesitic inclusions with vesicular interiors and chilled margins up to 10 cm are found in the later stages of phase 2 and compose up to 5% of the phase 3 lava. There is little evidence for preeruptive zonation of the magma body in composition, temperature (approximately 840 C), fO2 (19(exp -11), or water content, so we propose that eruption of the Chao complex was driven by intrusion of fresh, hot andesitic magma into a crystallizing and largely homogeneous body of dacitic magma

  4. SUR1-Associated Mechanisms Are Not Involved in Ischemic Optic Neuropathy 1 Day Post-Injury

    PubMed Central

    Nicholson, James D.; Guo, Yan; Bernstein, Steven L.

    2016-01-01

    Ischemia-reperfusion injury after central nervous system (CNS) injury presents a major health care challenge with few promising treatments. Recently, it has become possible to reduce edema after CNS injury by antagonizing a sulfonylurea receptor 1 (SUR1) regulated ion channel expressed after injury. SUR1 upregulation after injury is a necessary precondition for the formation of this channel, and has been implicated in white matter injury after clinical spinal cord trauma. Glibenclamide, an SUR1 antagonist, appears to have neuroprotective effect against cerebral stroke in an open-label small clinical trial and great effectiveness in reducing damage after varied experimental CNS injury models. Despite its importance in CNS injuries, SUR1 upregulation appears to play no part in rodent anterior ischemic optic neuropathy (rAION) injury as tested by real-time PCR and immunohistochemical staining of rAION-injured rat optic nerve (ON). Furthermore, the SUR1 antagonist glibenclamide administered immediately after rAION injury provided no protection to proximal ON microvasculature 1 day post-injury but may reduce optic nerve head edema in a manner unrelated to ON SUR1 expression. Our results suggest that there may be fundamental differences between rAION optic nerve ischemia and other CNS white matter injuries where SUR1 appears to play a role. PMID:27560494

  5. SUR1-Associated Mechanisms Are Not Involved in Ischemic Optic Neuropathy 1 Day Post-Injury.

    PubMed

    Nicholson, James D; Guo, Yan; Bernstein, Steven L

    2016-01-01

    Ischemia-reperfusion injury after central nervous system (CNS) injury presents a major health care challenge with few promising treatments. Recently, it has become possible to reduce edema after CNS injury by antagonizing a sulfonylurea receptor 1 (SUR1) regulated ion channel expressed after injury. SUR1 upregulation after injury is a necessary precondition for the formation of this channel, and has been implicated in white matter injury after clinical spinal cord trauma. Glibenclamide, an SUR1 antagonist, appears to have neuroprotective effect against cerebral stroke in an open-label small clinical trial and great effectiveness in reducing damage after varied experimental CNS injury models. Despite its importance in CNS injuries, SUR1 upregulation appears to play no part in rodent anterior ischemic optic neuropathy (rAION) injury as tested by real-time PCR and immunohistochemical staining of rAION-injured rat optic nerve (ON). Furthermore, the SUR1 antagonist glibenclamide administered immediately after rAION injury provided no protection to proximal ON microvasculature 1 day post-injury but may reduce optic nerve head edema in a manner unrelated to ON SUR1 expression. Our results suggest that there may be fundamental differences between rAION optic nerve ischemia and other CNS white matter injuries where SUR1 appears to play a role.

  6. SUR1-Associated Mechanisms Are Not Involved in Ischemic Optic Neuropathy 1 Day Post-Injury.

    PubMed

    Nicholson, James D; Guo, Yan; Bernstein, Steven L

    2016-01-01

    Ischemia-reperfusion injury after central nervous system (CNS) injury presents a major health care challenge with few promising treatments. Recently, it has become possible to reduce edema after CNS injury by antagonizing a sulfonylurea receptor 1 (SUR1) regulated ion channel expressed after injury. SUR1 upregulation after injury is a necessary precondition for the formation of this channel, and has been implicated in white matter injury after clinical spinal cord trauma. Glibenclamide, an SUR1 antagonist, appears to have neuroprotective effect against cerebral stroke in an open-label small clinical trial and great effectiveness in reducing damage after varied experimental CNS injury models. Despite its importance in CNS injuries, SUR1 upregulation appears to play no part in rodent anterior ischemic optic neuropathy (rAION) injury as tested by real-time PCR and immunohistochemical staining of rAION-injured rat optic nerve (ON). Furthermore, the SUR1 antagonist glibenclamide administered immediately after rAION injury provided no protection to proximal ON microvasculature 1 day post-injury but may reduce optic nerve head edema in a manner unrelated to ON SUR1 expression. Our results suggest that there may be fundamental differences between rAION optic nerve ischemia and other CNS white matter injuries where SUR1 appears to play a role. PMID:27560494

  7. [Marine algae of Baja California Sur, Mexico: nutritional value].

    PubMed

    Carrillo Domínguez, Silvia; Casas Valdez, Margarita; Ramos Ramos, Felipe; Pérez-Gil, Fernando; Sánchez Rodríguez, Ignacio

    2002-12-01

    The Baja California Peninsula is one of the richest regions of seaweed resources in México. The objective of this study was to determine the chemical composition of some marine algae species of Baja California Sur, with an economical potential due to their abundance and distribution, and to promote their use as food for human consumption and animal feeding. The algae studied were Green (Ulva spp., Enteromorpha intestinalis, Caulerpa sertularoides, Bryopsis hypnoides), Red (Laurencia johnstonii, Spyridia filamentosa, Hypnea valentiae) and Brown (Sargassum herporizum, S. sinicola, Padina durvillaei, Hydroclathrus clathrathus, Colpomenia sinuosa). The algae were dried and ground before analysis. In general, the results showed that algae had a protein level less than 11%, except L. johnstonii with 18% and low energy content. The ether extract content was lower than 1%. However, the algae were a good source of carbohydrates and inorganic matter.

  8. 46 CFR 7.135 - Point Sur, CA to Cape Blanco, OR.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... shore. (e) A line drawn from the northwestern tip of Tomales Point to latitude 38°15.1′ N. longitude 123... 46 Shipping 1 2014-10-01 2014-10-01 false Point Sur, CA to Cape Blanco, OR. 7.135 Section 7.135... Pacific Coast § 7.135 Point Sur, CA to Cape Blanco, OR. (a) A line drawn from Monterey Harbor Light “6”...

  9. 46 CFR 7.135 - Point Sur, CA to Cape Blanco, OR.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... shore. (e) A line drawn from the northwestern tip of Tomales Point to latitude 38°15.1′ N. longitude 123... 46 Shipping 1 2012-10-01 2012-10-01 false Point Sur, CA to Cape Blanco, OR. 7.135 Section 7.135... Pacific Coast § 7.135 Point Sur, CA to Cape Blanco, OR. (a) A line drawn from Monterey Harbor Light “6”...

  10. 46 CFR 7.135 - Point Sur, CA to Cape Blanco, OR.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... shore. (e) A line drawn from the northwestern tip of Tomales Point to latitude 38°15.1′ N. longitude 123... 46 Shipping 1 2011-10-01 2011-10-01 false Point Sur, CA to Cape Blanco, OR. 7.135 Section 7.135... Pacific Coast § 7.135 Point Sur, CA to Cape Blanco, OR. (a) A line drawn from Monterey Harbor Light “6”...

  11. 46 CFR 7.135 - Point Sur, CA to Cape Blanco, OR.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... shore. (e) A line drawn from the northwestern tip of Tomales Point to latitude 38°15.1′ N. longitude 123... 46 Shipping 1 2013-10-01 2013-10-01 false Point Sur, CA to Cape Blanco, OR. 7.135 Section 7.135... Pacific Coast § 7.135 Point Sur, CA to Cape Blanco, OR. (a) A line drawn from Monterey Harbor Light “6”...

  12. 46 CFR 7.130 - Point Conception, CA to Point Sur, CA.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Point Conception, CA to Point Sur, CA. 7.130 Section 7.130 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC BOUNDARY LINES Pacific Coast § 7.130 Point Conception, CA to Point Sur, CA. (a) A line drawn from the southernmost extremity of Fossil Point at longitude...

  13. 46 CFR 7.135 - Point Sur, CA to Cape Blanco, OR.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Point Sur, CA to Cape Blanco, OR. 7.135 Section 7.135 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC BOUNDARY LINES Pacific Coast § 7.135 Point Sur, CA to Cape Blanco, OR. (a) A line drawn from Monterey Harbor Light “6” to latitude 36°36.5′ N. longitude...

  14. Modelisations des effets de surface sur les jets horizontaux subsoniques d'hydrogene et de methane

    NASA Astrophysics Data System (ADS)

    Gomez, Luis Fernando

    Le developpement des codes et de normes bases sur une methodologie scientifique requiert la capacite de predire l'etendue inflammable de deversements gazeux d'hydrogene sous differentes conditions. Des etudes anterieures ont deja etabli des modeles bases sur les lois de conservation de la mecanique des fluides basees sur des correlations experimentales qui permettent de predire la decroissance de la concentration et de la vitesse d'un gaz le long de l'axe d'un jet libre vertical. Cette etude s'interesse aux effets de proximite a une surface horizontale parallele sur un jet turbulent. Nous nous interessons a son impact sur l'etendue du champ de la concentration et sur l'enveloppe inflammable en particulier. Cette etude est comparative : l'hydrogene est compare au methane. Ceci permet de degager l'influence des effets de difference de la densite sur le comportement du jet, et de comparer le comportement de l'hydrogene aux correlations experimentales, qui ont ete essentiellement etablies pour le methane. Un modele decrivant l'evolution spatio-temporelle du champ de concentration du gaz dilue est propose, base sur la mecanique des fluides computationnelle. Cette approche permet de varier systematiquement les conditions aux frontieres (proximite du jet a la surface, par exemple) et de connaitre en detail les proprietes de l'ecoulement. Le modele est implemente dans le code de simulations par volumes finis de FLUENT. Les resultats des simulations sont compares avec les lois de similitudes decoulant de la theorie des jets d'ecoulements turbulents libres ainsi qu'avec les resultats experimentaux disponibles. L'effet de la difference des masses molaires des constituantes du jet et des constituantes du milieu de dispersion est egalement etudie dans le contexte du comportement d'echelle de la region developpee du jet.

  15. Carcinome hépatocellulaire non fibrolamellaire sur foie sain

    PubMed Central

    Bouomrani, Salem; Kilani, Ichrak; Nouma, Hanène; Slama, Alaeddine; Beji, Maher

    2014-01-01

    Le carcinome hépatocellulaire (CHC) survient le plus souvent sur foie de cirrhose. Sa survenue sur un foie sain est exceptionnelle et pose un véritable défit diagnostique pour le clinicien. Nous rapportons l'observation d'un patient de 53 ans, sans antécédents pathologiques notables qui fût admis pour exploration d'une douleur de l'hypochondre droit évoluant depuis quelques mois avec une exacerbation récente, associée à un amaigrissement important et une altération de l’état général. L'examen clinique notait une hépatomégalie ferme et douloureuse. L’échographie abdominale montrait une masse hétérogène du secteur latéral droit du foie faisant 10 cm de grand axe. La TDM abdominale montrait une masse tissulaire, hétérogène, à vascularisation artérielle importante, mesurant 10 cm de diamètre et occupant le secteur latéral droit du foie. Cette tumeur comprime la branche portale droite sans signes d'extension. Il n'y avait pas d'adénopathie ni d’épanchement intra abdominal. La ponction biopsique écho-guidée avait conclu à un CHC non fibrolamellaire. Le bilan biologique, en particulier les transaminases, le taux de prothrombine, l’électrophorèse des protéines sanguine et l'alpha foeto-protéine, était sans anomalies. Les sérologies de l'hépatites virales B et C ainsi que la recherche des auto anticorps spécifiques des hépatites auto immunes et le bilan cuprique étaient aussi négatives. Vue l’âge, le stade avancé de la tumeur et l'altération de l’état général la conduite thérapeutique était de s'abstenir. PMID:25419293

  16. Effets de la formation sur la violence conjugale

    PubMed Central

    Zaher, Eman; Keogh, Kelly; Ratnapalan, Savithiri

    2014-01-01

    Résumé Objectif Décrire et évaluer l’efficacité de la formation concernant la violence conjugale pour améliorer les connaissances et permettre la reconnaissance et la prise en charge par les médecins des femmes victimes de violence. Sources des données On a fait une recension dans la base de données des révisions systématiques de Cochrane, MEDLINE, PubMed, PsycINFO, ERIC et EMBASE pour trouver des articles publiés entre le 1e janvier 2000 et le 1e novembre 2012. Des recherches manuelles ont complété cette recension pour cerner des articles pertinents à l’aide d’une stratégie de recherche combinant des textes, mots et expressions MeSH. Sélection des études On a choisi des études randomisées contrôlées qui portaient sur des interventions éducatives à l’intention des médecins et fournissaient des données sur les effets des interventions. Synthèse On a inclus 9 études randomisées contrôlées qui décrivaient différentes approches pédagogiques et diverses mesures des résultats. Trois études examinaient les effets d’interventions éducatives pour des médecins en formation postdoctorale et ont constaté une augmentation des connaissances, mais il n’y a eu aucun changement dans le comportement en ce qui a trait à l’identification des victimes de violence conjugale. Six études portaient sur des interventions éducatives pour des médecins en pratique active. Trois d’entre elles utilisaient une approche à multiples facettes pour les médecins, qui combinait une formation ainsi que des interventions de soutien de la part du système pour changer les comportements des médecins, comme une sensibilisation générale accrue à la violence conjugale au moyen de brochures et d’affiches, des aide-mémoire pour rappeler aux médecins comment identifier les victimes, des moyens pour faciliter l’accès des médecins à des services de soutien pour les victimes, la réalisation d’audits et la fourniture de rétroaction. Les

  17. Sur Lago area, Venezuela: Three dimensional integrated seismic interpretation

    SciTech Connect

    Growcott, A.; McIan, A.; Ramirez, R. )

    1993-02-01

    In 1988, 550 square km of 3D seismic data were acquired in the Sur Del Lago area. The aims of the survey were (1) To better define structures already identified from the existing 1 [times] 1 km 2D seismic grid at the level of potential Cretaceous limestone reservoirs and (2) To further study the prospectivity of potential structural and stratigraphic traps within the Tertiary section. Detailed interpretation of the 3D survey using an interactive workstation led to an improved structural definition at the Cogollo limestone level and the identification of fault related inversion lineaments and basement related Cretaceous limestone structures. Based upon the new seismic interpretation a 4 well exploration project was planned. The new program commenced with the drilling of exploration well SLA-7-IX in 1991 which proved commercial amounts of hydrocarbons in the western part of the area. Detailed information collected from the exploration wells includes a comprehensive electric log suite, ditch cuttings and vertical seismic profiles. The information is being used as detailed lithological, stratigraphic and seismic data input for velocity modeling, ray trace modeling, seismic attribute analysis, and reservoir characterization software in order to further understand the structural and stratigraphic potential of the area.

  18. SurR regulates hydrogen production in Pyrococcus furiosus by a sulfur-dependent redox switch

    PubMed Central

    Yang, Hua; Lipscomb, Gina L.; Keese, Annette M.; Schut, Gerrit J.; Thomm, Michael; Adams, Michael W. W.; Wang, Bi Cheng; Scott, Robert A.

    2010-01-01

    SUMMARY We present structural and biochemical evidence for a redox switch in the archaeal transcriptional regulator SurR of Pyrococcus furiosus, a hyperthermophilic anaerobe. P. furiosus produces H2 during fermentation, but undergoes a metabolic shift to produce H2S when elemental sulfur (S0) becomes available. Changes in gene expression occur within minutes of S0 addition, and the majority of these S0-responsive genes are regulatory targets of SurR, a key regulator involved in primary S0 response. SurR was shown in vitro to have dual functionality, activating transcription of some of these genes, notably the hydrogenase operons, and repressing others, including a gene encoding sulfur reductase. This work demonstrates via biochemical and structural evidence that the activity of SurR is modulated by cysteine residues in a CxxC motif that constitute a redox switch. Oxidation of the switch with S0 inhibits sequence-specific DNA binding by SurR, leading to deactivation of genes related to H2 production and derepression of genes involved in S0 metabolism. PMID:20598080

  19. The Activity of Escherichia coli Chaperone SurA Is Regulated by Conformational Changes Involving a Parvulin Domain

    PubMed Central

    Soltes, Garner R.; Schwalm, Jaclyn; Ricci, Dante P.

    2016-01-01

    ABSTRACT The periplasmic chaperone SurA is critical for the biogenesis of outer membrane proteins (OMPs) and, thus, the maintenance of membrane integrity in Escherichia coli. The activity of this modular chaperone has been attributed to a core chaperone module, with only minor importance assigned to the two SurA peptidyl-prolyl isomerase (PPIase) domains. In this work, we used synthetic phenotypes and covalent tethering to demonstrate that the activity of SurA is regulated by its PPIase domains and, furthermore, that its activity is correlated with the conformational state of the chaperone. When combined with mutations in the β-barrel assembly machine (BAM), SurA mutations resulting in deletion of the second parvulin domain (P2) inhibit OMP assembly, suggesting that P2 is involved in the regulation of SurA. The first parvulin domain (P1) potentiates this autoinhibition, as mutations that covalently tether the P1 domain to the core chaperone module severely impair OMP assembly. Furthermore, these inhibitory mutations negate the suppression of and biochemically stabilize the protein specified by a well-characterized gain-of-function mutation in P1, demonstrating that SurA cycles between distinct conformational and functional states during the OMP assembly process. IMPORTANCE This work reveals the reversible autoinhibition of the SurA chaperone imposed by a heretofore underappreciated parvulin domain. Many β-barrel-associated outer membrane (OM) virulence factors, including the P-pilus and type I fimbriae, rely on SurA for proper assembly; thus, a mechanistic understanding of SurA function and inhibition may facilitate antibiotic intervention against Gram-negative pathogens, such as uropathogenic Escherichia coli, E. coli O157:H7, Shigella, and Salmonella. In addition, SurA is important for the assembly of critical OM biogenesis factors, such as the lipopolysaccharide (LPS) transport machine, suggesting that specific targeting of SurA may provide a useful means to

  20. Structure and function of an archaeal homolog of survival protein E (SurEalpha): an acid phosphatase with purine nucleotide specificity.

    PubMed

    Mura, Cameron; Katz, Jonathan E; Clarke, Steven G; Eisenberg, David

    2003-03-01

    The survival protein E (SurE) family was discovered by its correlation to stationary phase survival of Escherichia coli and various repair proteins involved in sustaining this and other stress-response phenotypes. In order to better understand this ancient and well-conserved protein family, we have determined the 2.0A resolution crystal structure of SurEalpha from the hyperthermophilic crenarchaeon Pyrobaculum aerophilum (Pae). This first structure of an archaeal SurE reveals significant similarities to and differences from the only other known SurE structure, that from the eubacterium Thermatoga maritima (Tma). Both SurE monomers adopt similar folds; however, unlike the Tma SurE dimer, crystalline Pae SurEalpha is predominantly non-domain swapped. Comparative structural analyses of Tma and Pae SurE suggest conformationally variant regions, such as a hinge loop that may be involved in domain swapping. The putative SurE active site is highly conserved, and implies a model for SurE bound to a potential substrate, guanosine-5'-monophosphate (GMP). Pae SurEalpha has optimal acid phosphatase activity at temperatures above 90 degrees C, and is less specific than Tma SurE in terms of metal ion requirements. Substrate specificity also differs between Pae and Tma SurE, with a more specific recognition of purine nucleotides by the archaeal enzyme. Analyses of the sequences, phylogenetic distribution, and genomic organization of the SurE family reveal examples of genomes encoding multiple surE genes, and suggest that SurE homologs constitute a broad family of enzymes with phosphatase-like activities.

  1. Use of the Falcon assay screening test--enzyme-linked immunosorbent assay (FAST-ELISA) and the enzyme-linked immunoelectrotransfer blot (EITB) to determine the prevalence of human fascioliasis in the Bolivian Altiplano.

    PubMed

    Hillyer, G V; Soler de Galanes, M; Rodriguez-Perez, J; Bjorland, J; Silva de Lagrava, M; Ramirez Guzman, S; Bryan, R T

    1992-05-01

    A collaborative study between the University of Puerto Rico School of Medicine, the Centers for Disease Control, the Bolivian Ministry of Health, and private voluntary organizations (Foster Parents Plan International and Danchurchaid) working in Bolivia has identified a region in the northwestern Altiplano of Bolivia near Lake Titicaca as harboring the highest prevalence of human fascioliasis in the world reported to date. Two serologic techniques (the Falcon assay screening test-enzyme-linked immunosorbent assay [FAST-ELISA] and the enzyme-linked immunoelectrotransfer blot [EITB]) were used in the determination of its prevalence. One hundred serum samples and 73 stool samples were obtained from Aymara Indians from Corapata, Bolivia. Antibody absorbance levels to Fasciola hepatica excretion-secretion antigens were compared with EITB banding patterns using the same antigen preparation. A positive FAST-ELISA result was defined as an absorbance value greater than the mean plus three standard deviations of two sets of normal negative controls (Puerto Rican and Bolivian). Using this criterion, 53 of 100 sera tested were found positive by this technique. Within this group, 19 (95%) of 20 individuals who were parasite positive were also positive by FAST-ELISA. An additional 24 individuals who were negative for F. hepatica eggs and 10 individuals for whom no specimens were received were also positive by FAST-ELISA. Among the 53 individuals negative for F. hepatica eggs, 29 were also negative by FAST-ELISA. The EITB analysis of the sera from confirmed infected individuals revealed at least three F. hepatica (Fh) bands with molecular weights of 12, 17, and 63 kD, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. The Classroom as Big Sur: Notes on the Liaison Between Evaluation and Professional Growth

    ERIC Educational Resources Information Center

    Sneeden, Ralph

    2013-01-01

    Bill Frisell's new album ("Big Sur") was heralded with a short documentary about its impulse and inception: Frisell's retreat to an isolated coastal ranch in Central California. In the video, he describes the influence of the place, the dramatic and evocative landscape, and how it ultimately became the subject and theme for the…

  3. Seafloor Rocks and Sediments of the Continental Shelf From Monterey Bay to Point Sur, California

    USGS Publications Warehouse

    Eittreim, Stephen L.; Anima, Roberto J.; Stevenson, Andrew J.; Wong, Florence L.

    2000-01-01

    Introduction Acoustic swath mapping of the greater Monterey Bay area continental shelf from Point Ano Nuevo to Point Sur reveals complex patterns of rock outcrops on the shelf, and coarse sand bodies that occur in distinct depressions on the inner and mid-shelves. This publication portrays the seafloor components in a 36- by 48-inch map sheet at 1:100,000 scale.

  4. Reflections on "Petit Battement sur le Cou de Pied": Is It Still Relevant?

    ERIC Educational Resources Information Center

    Paskevska, Anna

    2007-01-01

    This article presents multiple perspectives of "petit battement sur le cou de pied". These perspectives include historical, biomechanical, and pedagogic points of view. The article offers useful information for ballet specialists and applied research studies aimed at ballet pedagogy. (Contains 2 tables and 5 figures.)

  5. Eisosomes promote the ability of Sur7 to regulate plasma membrane organization in Candida albicans

    PubMed Central

    Wang, Hong X.; Douglas, Lois M.; Veselá, Petra; Rachel, Reinhard; Malinsky, Jan; Konopka, James B.

    2016-01-01

    The plasma membrane of the fungal pathogen Candida albicans forms a protective barrier that also mediates many processes needed for virulence, including cell wall synthesis, invasive hyphal morphogenesis, and nutrient uptake. Because compartmentalization of the plasma membrane is believed to coordinate these diverse activities, we examined plasma membrane microdomains termed eisosomes or membrane compartment of Can1 (MCC), which correspond to ∼200-nm-long furrows in the plasma membrane. A pil1∆ lsp1∆ mutant failed to form eisosomes and displayed strong defects in plasma membrane organization and morphogenesis, including extensive cell wall invaginations. Mutation of eisosome proteins Slm2, Pkh2, and Pkh3 did not cause similar cell wall defects, although pkh2∆ cells formed chains of furrows and pkh3∆ cells formed wider furrows, identifying novel roles for the Pkh protein kinases in regulating furrows. In contrast, the sur7∆ mutant formed cell wall invaginations similar to those for the pil1∆ lsp1∆ mutant even though it could form eisosomes and furrows. A PH-domain probe revealed that the regulatory lipid phosphatidylinositol 4,5-bisphosphate was enriched at sites of cell wall invaginations in both the sur7∆ and pil1∆ lsp1∆ cells, indicating that this contributes to the defects. The sur7∆ and pil1∆ lsp1∆ mutants displayed differential susceptibility to various types of stress, indicating that they affect overlapping but distinct functions. In support of this, many mutant phenotypes of the pil1∆ lsp1∆ cells were rescued by overexpressing SUR7. These results demonstrate that C. albicans eisosomes promote the ability of Sur7 to regulate plasma membrane organization. PMID:27009204

  6. Influence des effets de température quasi-statiques du premier ordre sur les dispositifs à ondes de surface transverses sur sillons gravés

    NASA Astrophysics Data System (ADS)

    Ballandras, S.; Gavignet, E.; Bigler, E.

    1995-02-01

    The present study is devoted to the theoretical calculation of the first order quasi-static temperature coefficient of surface transverse waves which can propagate under shallow groove gratings. The model presented here associates an analytical description of non-perturbed surface transverse waves on an anisotropic substrate developed by Auld and Tiersten's perturbation method. This approach has been implemented in the case of quartz delay lines corrugated with rectangular grooves. It is shown that singly rotated quartz cuts can be theoretically found exhibiting a first-order temperature coefficient close to zero. The sensitivity of this coefficient versus the groove depth is also theoretically demonstrated. La présente étude consiste à calculer le coefficient de température du premier ordre d'un résonateur à ondes transverses de surface se propageant sous un réseau de sillons gravés de forme quelconque. Ce calcul fait intervenir un modèle analytique de propagation des ondes sur un substrat anisotrope développé par Auld et une méthode de perturbation mise au point par Tiersten. Cette approche théorique a été mise en oeuvre pour traiter le cas des dispositifs à sillons gravés de profil rectangulaire sur quartz. On montre ainsi qu'il existe des coupes de quartz à simple rotation présentant un coefficient de température du premier ordre théorique proche de zéro. L'influence de la profondeur de gravure des sillons sur ce coefficient est également mise en évidence théoriquement.

  7. Évolution des lignes directrices sur le traitement de la dyslipidémie

    PubMed Central

    John Bosomworth, N.

    2014-01-01

    Résumé Objectif Comprendre comment les nouvelles lignes directrices sur la prise en charge du risque cardiovasculaire publiées par l’American Heart Association et l’American College of Cardiology (AHA-ACC) peuvent être interprétées et utilisées dans le contexte canadien. Sources des données Les lignes directrices de l’AHA-ACC ont été examinées, de même que toutes les références. Des recherches indépendantes dans PubMed ont été effectuées pour inclure l’ajout aux statines d’autres antihyperlipidémiants et l’emploi de calculatrices médicales visant à aider le patient à comprendre. Message principal Les nouvelles lignes directrices de l’AHA-ACC s’appuient sur les meilleures données probantes disponibles actuellement en matière de traitement de la dyslipidémie. Cela inclut le risque cardiovasculaire (CV) sur 10 ans comme seuil thérapeutique au lieu du taux de cholestérol des lipoprotéines de faible densité, de même que l’abandon des cibles thérapeutiques de lipoprotéines de faible densité. On met de plus en plus l’accent sur les interventions alimentaires et l’exercice, avec l’amorce d’un effort pour quantifier l’effet de ces interventions. Les statines constituent la principale intervention pharmacologique, et l’ajout d’autres médicaments pour accentuer la baisse lipidique n’est plus recommandé. En ce qui concerne l’application au Canada, les tables de risque de Framingham sont plus appropriées pour évaluer le risque que les équations de cohortes regroupées utilisées aux États-Unis. Les calculatrices du risque de maladie cardiovasculaire (MCV) devraient contenir de l’information sur l’âge cardiovasculaire et devraient pouvoir illustrer le risque et les interventions de rechange afin d’aider le patient à comprendre et de favoriser la prise de décision éclairée. Conclusion L’attention sur les meilleures données probantes concernant le risque CV peut simplifier le traitement de la

  8. Réalisation de réseaux sur polymères par laser UV

    NASA Astrophysics Data System (ADS)

    Castex, M. C.; Fischer, A.; Simeonov, D.; Adès, D.; Siove, A.

    2003-06-01

    Nous présentons ici une méthode très simple de réalisation de réseaux d'amplitude de pas sub-micronique sur des films polymères à base de carbazote déposés sur des substrat de silice. Les réseaux sont fabriqués en irradiant avec un faisceau laser à 193nm un masque de phase placé au contact du film. La qualité des réseaux obtenus permet désormais d'envisager la réalisation de micro-cavités lasers de type planaire permettant de sélectionner une émission laser monomode autour de 400nm.

  9. A new species of Rhadinella (Serpentes: Colubridae) from the Sierra Madre del Sur of Guerrero, Mexico.

    PubMed

    Campillo, Gustavo; Dávila-Galavíz, Luis Fernando; Flores-Villela, Oscar; Campbell, Jonathan A

    2016-04-12

    We describe a new species of Rhadinella from the Sierra Madre del Sur of Guerrero, Mexico, a region where the genus was previously unknown. This diminutive species is a member of a group of snakes previously allocated in the Rhadinaea godmani group, and more recently transferred to the genus Rhadinella. These snakes may have conspicuous dark longitudinal striping on a pale brown to orange background or may have dark brown to blackish dorsal ground coloration, which mostly or completely obfuscates a pattern of longitudinal striping. The new species is mostly dark with barely discernible slightly paler or darker striping (depending on how striping is interpreted). The closest relative of the new species, on the basis of morphological similarities and biogeography, appears to be Rhadinella donaji which occurs to the east in the Sierra Madre del Sur of Oaxaca about 275 km from the type-locality of the new species.

  10. ABCC9/SUR2 in the brain: Implications for hippocampal sclerosis of aging and a potential therapeutic target.

    PubMed

    Nelson, Peter T; Jicha, Gregory A; Wang, Wang-Xia; Ighodaro, Eseosa; Artiushin, Sergey; Nichols, Colin G; Fardo, David W

    2015-11-01

    The ABCC9 gene and its polypeptide product, SUR2, are increasingly implicated in human neurologic disease, including prevalent diseases of the aged brain. SUR2 proteins are a component of the ATP-sensitive potassium ("KATP") channel, a metabolic sensor for stress and/or hypoxia that has been shown to change in aging. The KATP channel also helps regulate the neurovascular unit. Most brain cell types express SUR2, including neurons, astrocytes, oligodendrocytes, microglia, vascular smooth muscle, pericytes, and endothelial cells. Thus it is not surprising that ABCC9 gene variants are associated with risk for human brain diseases. For example, Cantu syndrome is a result of ABCC9 mutations; we discuss neurologic manifestations of this genetic syndrome. More common brain disorders linked to ABCC9 gene variants include hippocampal sclerosis of aging (HS-Aging), sleep disorders, and depression. HS-Aging is a prevalent neurological disease with pathologic features of both neurodegenerative (aberrant TDP-43) and cerebrovascular (arteriolosclerosis) disease. As to potential therapeutic intervention, the human pharmacopeia features both SUR2 agonists and antagonists, so ABCC9/SUR2 may provide a "druggable target", relevant perhaps to both HS-Aging and Alzheimer's disease. We conclude that more work is required to better understand the roles of ABCC9/SUR2 in the human brain during health and disease conditions.

  11. Multimodal 3-D reconstruction of human anatomical structures using SurLens Visualization System.

    PubMed

    Adeshina, A M; Hashim, R; Khalid, N E A; Abidin, S Z Z

    2013-03-01

    In the medical diagnosis and treatment planning, radiologists and surgeons rely heavily on the slices produced by medical imaging devices. Unfortunately, these image scanners could only present the 3-D human anatomical structure in 2-D. Traditionally, this requires medical professional concerned to study and analyze the 2-D images based on their expert experience. This is tedious, time consuming and prone to error; expecially when certain features are occluding the desired region of interest. Reconstruction procedures was earlier proposed to handle such situation. However, 3-D reconstruction system requires high performance computation and longer processing time. Integrating efficient reconstruction system into clinical procedures involves high resulting cost. Previously, brain's blood vessels reconstruction with MRA was achieved using SurLens Visualization System. However, adapting such system to other image modalities, applicable to the entire human anatomical structures, would be a meaningful contribution towards achieving a resourceful system for medical diagnosis and disease therapy. This paper attempts to adapt SurLens to possible visualisation of abnormalities in human anatomical structures using CT and MR images. The study was evaluated with brain MR images from the department of Surgery, University of North Carolina, United States and CT abdominal pelvic, from the Swedish National Infrastructure for Computing. The MR images contain around 109 datasets each of T1-FLASH, T2-Weighted, DTI and T1-MPRAGE. Significantly, visualization of human anatomical structure was achieved without prior segmentation. SurLens was adapted to visualize and display abnormalities, such as an indication of walderstrom's macroglobulinemia, stroke and penetrating brain injury in the human brain using Magentic Resonance (MR) images. Moreover, possible abnormalities in abdominal pelvic was also visualized using Computed Tomography (CT) slices. The study shows SurLens' functionality as

  12. [Polyplacophoran communities (Mollusca: Polyplacophora) at Bahia de La Paz, Baja California Sur, México].

    PubMed

    García Ríos, Cedar I; Alvarez Ruiz, Migdalia

    2007-03-01

    Eight species of polyplacophorans have been reported from La Bahia de la Paz, Baja California Sur, Mexico. We add Lepidochitona beanii, Chaetopleura lurida, Stenoplax limaciformis, S. mariposa, Lepidozona clathrata, L. serrata and Acanthochitona arragonites, increasing the known number of species to 15. Ordination analysis of five chiton communities at the site suggests a correlation of wave exposure to species composition and diversity: communities with intermediate wave exposure have more species (richness) and higher diversity (Shannon's index).

  13. [Polyplacophoran communities (Mollusca: Polyplacophora) at Bahia de La Paz, Baja California Sur, México].

    PubMed

    García Ríos, Cedar I; Alvarez Ruiz, Migdalia

    2007-03-01

    Eight species of polyplacophorans have been reported from La Bahia de la Paz, Baja California Sur, Mexico. We add Lepidochitona beanii, Chaetopleura lurida, Stenoplax limaciformis, S. mariposa, Lepidozona clathrata, L. serrata and Acanthochitona arragonites, increasing the known number of species to 15. Ordination analysis of five chiton communities at the site suggests a correlation of wave exposure to species composition and diversity: communities with intermediate wave exposure have more species (richness) and higher diversity (Shannon's index). PMID:18457125

  14. Etude du stockage de l'hydrogene sur des nanostructures de carbone microporeuses

    NASA Astrophysics Data System (ADS)

    Poirier, Eric

    2007-12-01

    Le stockage de l'hydrogene par adsorption sur des adsorbants nano-structures a ete etudie sous differentes conditions de pression et de temperature. Les adsorbants etudies sont principalement des nanotubes de carbone a simple paroi ainsi que des structures metallo-organiques. Les mesures ont ete realisees a l'aide de systemes gravimetriques et volumetriques tres sensibles specialement mis au point pour de petits echantillons necessitant un degazage in situ. Les appareils developpes, au nombre de quatre, comprennent deux systemes gravimetriques et deux systemes volumetriques. Ensemble, ces systemes couvrent la plage de pressions (0-100) bars ainsi que la plage de temperatures (77-295) K. Les differentes analyses montrent que l'adsorption d'hydrogene sur les adsorbants nano-structures etudies est maximale a 77 K et varie entre environ (1.5 et 4) % masse. A temperature ambiante, l'adsorption croit lineairement avec la pression et demeure sous les 1% masse pour des pressions inferieures a 100 bars. L'adsorption d'hydrogene sur ces materiaux dans ces conditions se compare notamment a celle obtenue sur des charbons actives. La modelisation de l'adsorption a egalement ete realisee dans des conditions cryogeniques a l'aide du modele de Dubinin-Astakhov sous une forme adaptee pour l'adsorption supercritique. Les enthalpies d'adsorption calculees a partir de ce modele varient sous les 6 kJ/mole et sont donc consistantes avec des processus de physisorption. L'applicabilite du modele de Dubinin-Astakhov suggere que l'adsorption d'hydrogene puisse etre representee par un processus de remplissage des pores par un pseudo-liquide. Ces travaux s'inscrivent dans un contexte ou la capacite d'adsorption reelle des nanostructures de carbone est sujette a la controverse. En consequence, l'approche experimentale adoptee se distingue par les differentes demarches mises de l'avant pour l'obtention de mesures fiables sur des echantillons de faibles masses ainsi que par son caractere

  15. Mechanisms of anticonvulsant and sedative actions of the ethanolic stem-bark extract of Ficus sur Forssk (Moraceae) in rodents.

    PubMed

    Ishola, Ismail O; Olayemi, Sunday O; Yemitan, Omoniyi K; Ekpemandudiri, Ngozi K

    2013-11-01

    Ficus sur Forssk (Moraceae) is used in traditional African medicine in the treatment of epilepsy, pain and inflammations. Anticonvulsant activity was investigated using picrotoxin (PTX), strychnine (SCN), isoniazid (INZ), pentylenetetrazole (PTZ) and N-methyl-D-aspartic acid NMDA models of convulsion. The phytochemical analysis of the extract revealed the presence of flavonoids, saponins, tannins, alkaloids and anthraquinone. Oral administration of Ficus sur, 1 h before intraperitoneal injection of chemical convulsants significantly (p < 0.05) delayed the onset and prolonged the duration of convulsions in PTX, SCN, INZ, PTZ and NMDA-induced seizures. However, the anticonvulsant activity of the ethanolic extract of Ficus sur was significantly reversed following intraperitoneal pre-treatment with flumazenil (GABA receptor antagonist), cyproheptadine (5-HT2 receptor antagonist) and L-NNA (nitric oxide synthase inhibitor) in picrotoxin-induced convulsion. The data obtained suggest that ethanol extract of Ficus sur possessed significant anticonvulsant effect, thereby confirming the traditional uses of Ficus sur in the treatment of epilepsies; mechanisms of which could involve interaction with GABAergic, glycinergic, serotonergic and glutaminergic system barks.

  16. Phenylephrine preconditioning in embryonic heart H9c2 cells is mediated by up-regulation of SUR2B/Kir6.2: A first evidence for functional role of SUR2B in sarcolemmal KATP channels and cardioprotection.

    PubMed

    Jovanović, Sofija; Ballantyne, Thomas; Du, Qingyou; Blagojević, Miloš; Jovanović, Aleksandar

    2016-01-01

    ATP-sensitive K(+) (KATP) channels were originally described in cardiomyocytes, where physiological levels of intracellular ATP keep them in a closed state. Structurally, these channels are composed of pore-forming inward rectifier, Kir6.1 or Kir6.2, and a regulatory, ATP-binding subunit, SUR1, SUR2A or SUR2B. SUR1 and Kir6.2 form pancreatic type of KATP channels, SUR2A and Kir6.2 form cardiac type of KATP channels, SUR2B and Kir6.1 form vascular smooth muscle type of KATP channels. The presence of SUR2B has been described in cardiomyocytes, but its functional significance and role has remained unknown. Pretreatment with phenylephrine (100nM) for 24h increased mRNA levels of SUR2B and Kir6.2, without affecting those levels of SUR1, SUR2A and Kir6.1 in embryonic heart H9c2 cells. Such increase was associated with increased K(+) current through KATP channels and Kir6.2/SUR2B protein complexes as revealed by whole cell patch clamp electrophysiology and immunoprecipitation/Western blotting respectively. Pretreatment with phenylephrine (100nM) generated a cellular phenotype that acquired resistance to chemical hypoxia induced by 2,4-dinitrophenol (DNP; 10mM), which was accompanied by increased in K(+) current in response to DNP (10mM). Cytoprotection afforded by phenylephrine (100nM) was abolished by infection of H9c2 cells with adenovirus containing Kir6.2AFA, a mutant form of Kir6.2 with largely reduced K(+) conductance. Taking all together, the present findings demonstrate that the activation of α1-adrenoceptors up-regulates SUR2B/Kir6.2 to confer cardioprotection. This is the first account of possible physiological role of SUR2B in cardiomyocytes.

  17. Etude sur les tendons en materiaux composites et leur application aux ancrages postcontraints

    NASA Astrophysics Data System (ADS)

    Chennouf, Adil

    L'objectif general de la presente these est d'evaluer le comportement a l'arrachement et au fluage d'ancrages injectes constitues de tendons en materiaux composites afin d'etablir des recommandations plus appropriees et realistes pour le dimensionnement et la conception. Quatre types de tendons en materiaux composites, deux a base de fibres d'aramide et deux a base de fibres de carbone, ont ete utilises dans l'etude. Les travaux de recherche de cette these ont porte notamment sur: (I) Une caracterisation physique et mecanique des tendons en materiaux composites utilises dans l'etude. (II) Une etude en laboratoire sur les coulis de scellement. La premiere etape de cette etude a concerne le developpement d'un coulis de scellement performant adapte aux tendons en materiaux composites et a differentes situations d'injection. La seconde etape a traite des essais de caracterisations physique et mecanique du coulis de scellement developpe comparativement a trois coulis de scellement usuels d'un meme rapport E/L de 0,4. (III) Une etude sur des modeles reduits d'ancrages injectes. (IV) Une etude sur des modeles d'ancrages a grande echelle. La synthese de ces etudes a permis d'enoncer les principales conclusions suivantes: (1) Les valeurs moyennes des charges de rupture des tendons en materiaux composites ont ete de 1% a 29% superieures a celles specifiees par les manufacturiers. (2) L'etude sur les coulis de scellement a permis le developpement de coulis de ciment repondant aux criteres fixes, soient une grande stabilite, une bonne fluidite, une legere expansion et de bonnes caracteristiques mecaniques. (3) Les tendons en materiaux composites ont montre des contraintes d'adherence maximum superieures a celles des tendons en acier. (4) Le type de fibre, la configuration et le fini de surface des tendons en materiaux composites gouvernent leur resistance a l'adherence. (5) L'introduction de sable et d'autres ajouts comme les fines de silice et la poudre d'aluminium au coulis

  18. SUR2 subtype (A and B)-dependent differential activation of the cloned ATP-sensitive K+ channels by pinacidil and nicorandil

    PubMed Central

    Shindo, Takashi; Yamada, Mitsuhiko; Isomoto, Shojiro; Horio, Yoshiyuki; Kurachi, Yoshihisa

    1998-01-01

    The classical ATP sensitive K+ (KATP) channels are composed of a sulphonylurea receptor (SUR) and an inward rectifying K+ channel subunit (BIR/Kir6.2). They are the targets of vasorelaxant agents called K+ channel openers, such as pinacidil and nicorandil.In order to examine the tissue selectivity of pinacidil and nicorandil, in vitro, we compared the effects of these agents on cardiac type (SUR2A/Kir6.2) and vascular smooth muscle type (SUR2B/Kir6.2) of the KATP channels heterologously expressed in HEK293T cells, a human embryonic kidney cell line, by using the patch-clamp method.In the cell-attached recordings (145 mM K+ in the pipette), pinacidil and nicorandil activated a weakly inwardly-rectifying, glibenclamide-sensitive 80 pS K+ channel in both the transfected cells.In the whole-cell configuration, pinacidil showed a similar potency in activating the SUR2B/Kir6.2 and SUR2A/Kir6.2 channels (EC50 of ∼2 and ∼10 μM, respectively). On the other hand, nicorandil activated the SUR2B/Kir6.2 channel >100 times more potently than the SUR2A/Kir6.2 (EC50 of ∼10 μM and >500 μM, respectively).Thus, nicorandil, but not pinacidil, preferentially activates the KATP channels containing SUR2B. Because SUR2A and SUR2B are diverse only in 42 amino acids at their C-terminal ends, it is strongly suggested that this short part of SUR2B may play a critical role in the action of nicorandil on the vascular type classical KATP channel. PMID:9692785

  19. Intragenic single nucleotide polymorphism haplotype analysis of SUR1 mutations in familial hyperinsulinism.

    PubMed

    Glaser, B; Furth, J; Stanley, C A; Baker, L; Thornton, P S; Landau, H; Permutt, M A

    1999-01-01

    Familial hyperinsulinism (HI; MIM# 256450) is an autosomal recessive disorder of pancreatic beta-cell function, characterized by inadequate suppression of insulin secretion despite severe recurrent fasting hypoglycemia. Subtotal pancreatectomy is frequently required to prevent permanent neurologic sequelae. The incidence of HI in the Caucasian population is estimated at 1:50,000, however an apparent increased incidence among Ashkenazi Jews and Saudi Arabian Arabs has been reported. A locus for HI was assigned by linkage analyses to human chromosome 11p15.1. The sulfonylurea receptor (MIM# 600509, SUR1) and the potassium channel, inwardly rectifying, subfamily J member 11 (MIM# 600937, KIR6.2) genes, 2 components of the beta-cell K(ATP) channel, are clustered in this chromosomal region, and mutations in these genes have been implicated in HI. We previously demonstrated that two mutations in the SUR1 gene are present on approximately 88% of HI-associated chromosomes in Ashkenazi Jewish patients. Haplotype analysis with microsatellite markers flanking the gene revealed that one mutation (delF1388), reported only in Ashkenazi probands, occurred on two related extended haplotypes. By contrast, the second, more common mutation (3992-9g-->a) was associated with nine different intergenic haplotypes and has been reported in non-Jewish HI patients as well. In this study, we evaluated disease-associated chromosomes from 41 Ashkenazi Jewish and 2 non-Jewish HI patients carrying the 3992-9g-->a mutation by assessing haplotypes defined by nine common single nucleotide polymorphisms (SNPs), six in the SUR1 gene, and three in the KIR6.2 gene. Our results indicate that all 54 chromosomes carrying the 3992-9g-->a mutation in the Jewish patients appear to have originated from one founder mutation, whereas the same mutation on chromosomes from non-Jewish patients originated independently. Furthermore, our findings have implications concerning the HI-associated chromosomes on which no

  20. Instrumentation pour la spectroscopie laser sur faisceau d'ions rapides

    NASA Astrophysics Data System (ADS)

    Bazin, Marc

    Devant l'emergence des technologies exploitant l'infiniment petit, la spectroscopie atomique et moleculaire devient de plus en plus incontournable pour comprendre precisement les mecanismes quantiques impliques dans l'interaction des molecules. C'est le cas notamment de la nanotechnologie, de la dynamique reactionnelle des gaz a effet de serre ou simplement de l'identification des molecules constituant certains objets de l'astrophysique. Bien qu'un travail considerable soit deja accompli pour comprendre la dissociation ou la formation des molecules simples, il reste a vaincre la complexite des mecanismes impliques lorsque les molecules possedent plus de trois noyaux. Parmi les rares techniques de spectroscopie a tres haute resolution (jusqu'a la structure hyperfine), la spectroscopie laser sur faisceaux d'ions rapides est une methode experimentale eprouvee depuis trois decennies environ. Cette methode spectroscopique fournit des resultats comptant parmi les meilleurs pour obtenir des constantes moleculaires precises et permettre la reduction du spectre moleculaire. Une particularite remarquable de notre instrument est la possibilite d'enregistrer le signal de fragmentation moleculaire par laser via les etats de predissociation de la molecule etudiee. Notre contribution a ete d'ameliorer et de moderniser l'equipement existant. Nous avons augmente la resolution spectrale de notre instrument. Nous avons atteint notre principal objectif, a savoir, la possibilite d'acquerir des spectres selon deux modes : par detection du signal synchronisee sur le faisceau laser module en frequence ou par detection du signal directement par comptage. Cette derniere methode est une premiere sur ce type d'instrument et son principal interet a ete d'obtenir une meilleure mesure de l'elargissement de raie. Nous sommes parvenus a mettre clairement en evidence l'elargissement de raie avec la puissance laser en utilisant la methode de detection par comptage direct. La fluorescence induite par

  1. Salt Playas of the Bolivian Altiplano

    NASA Technical Reports Server (NTRS)

    2003-01-01

    In the high plateau of southwestern Bolivia, two large salt deserts, or playas, are located between the eastern and western Andes. The Salar de Uyuni is the largest and highest playa in the world, encompassing an area of more than 9000 square kilometers and situated more than 3600 meters above sea level. It is separated by a range of hills from its smaller neighbor to the north, the Salar de Coipasa. During the Pleistocene the climate of the region was wetter and the entire area was covered by a massive lake. As the waters slowly dried, abundant dissolved minerals were left behind to form the playas. The salt pans are now excellent indicators of rainfall fluctuations within the region and are also important sites for the study of paleoclimatology.

    These two image pairs from the Multi-angle Imaging SpectroRadiometer (MISR)depict the playas on January 16, 2002 and January 3, 2003. At this time of year the wet season has already begun, and the Salar de Coipaso is usually at least partially flooded. Data from these two dates were processed identically to preserve relative variations in brightness between them. Varying degrees of surface moisture around the two playas are illustrated by the different display techniques of the right and left-hand panels.

    At left are two false-color views acquired by MISR's nadir camera. Data from the near-infrared, green and blue bands are displayed as red, green and blue. This spectral display causes bright, wet surfaces to appear blue-green because water selectively absorbs longer wavelengths such as near-infrared. Significantly more standing water is present in the Salar de Coipaso in 2002 than in 2003. However, a stronger signal at the near-infrared band on the 2003 date, which causes the overall hue in the 2003 image to be redder than 2002, suggests an increase in photosynthetic activity (plant growth) at the 2003 date compared with one year earlier.

    The right-hand panels were created using only red band data, and are multi-angle composites in which color variations serve as a proxy for changes in angular reflectance. Data from the 46-degree forward, nadir and 46-degree backward-viewing cameras are displayed here as red, green and blue. The angular composites contain information relating to surface moisture and/or texture characteristics that are not apparent with a single view. In the southern hemisphere, the backward pointing cameras receive a stronger signal from surfaces which predominantly forward scatter sunlight (which generally tend to be smooth and/or wet surfaces). The salt encrusted playas appear bright white and gray but the edges of the playas and some smaller salt flats exhibit a purple-blue hue that corresponds with enhanced forward scattering, possibly caused by greater moisture content of these soils. If this interpretation is correct, it indicates that the soil moisture content is greater around the playa perimeters on the 2003 date.

    Thin, wispy clouds that are almost invisible over the Salar de Uyuni in the nadir 2003 image are also more easily identified using the composite views, since geometric parallax associated with the clouds' elevation above the surface causes the individual camera images to be spatially separated.

    The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 11071 and 16197. The panels cover an area of 199 kilometers x 174 kilometers, and utilize data from blocks 106 to 107 within World Reference System-2 path 233.

  2. Grossesse sur cicatrice de césarienne: à propos d'un cas et revue de la literature

    PubMed Central

    Lachiri, Boutaina; Zazi, Abdelgheni; Benkerroum, Zineb; Hafidi, Moulay Rachid; Kouach, Jaouad; Rahali, Driss Moussaoui; Dehayni, Mohamed

    2015-01-01

    La grossesse sur cicatrice de césarienne est une forme rare de grossesse ectopique qui engage le pronostic vital et fonctionnel utérin par hémorragie ou par rupture utérine précoce. Nous rapportons le cas d'une grossesse ectopique sur cicatrice de césarienne diagnostiquée à 11 semaines d'aménorrhée suite à une aspiration blanche pour grossesse arrêtée chez une patiente de 43 ans porteuse d'un utérus bi-cicatriciel. A travers cette observation ainsi qu'une revue de la littérature les auteurs vont essayer de mettre le point sur les méthodes diagnostiques et thérapeutiques de cette entité rare afin d'améliorer la prise en charge. PMID:26213603

  3. Effet de la composition des materiaux composites sur la caracterisation et detection par ondes de Lamb

    NASA Astrophysics Data System (ADS)

    Ostiguy, Pierre-Claude

    Les matériaux composites sont de plus en plus utilisés en aéronautique. Leurs excellentes propriétés mécaniques et leur faible poids leur procurent un avantage certain par rapport aux matériaux métalliques. Ceux-ci étant soumis à diverses conditions de chargement et environnementales, ils sont suceptibles de subir plusieurs types d'endommagements, compromettant leur intégrité. Des méthodes fiables d'inspection sont donc nécessaires pour évaluer leur intégrité. Néanmoins, peu d'approches non destructives, embarquées et efficaces sont présentement utilisées. Ce travail de recherche se penche sur l'étude de l'effet de la composition des matériaux composites sur la détection et la caractérisation par ondes guidées. L'objectif du projet est de développer une approche de caractérisation mécanique embarquée permettant d'améliorer la performance d'une approche d'imagerie par antenne piézoélectriques sur des structures composite et métalliques. La contribution de ce projet est de proposer une approche embarquée de caractérisation mécanique par ultrasons qui ne requiert pas une mesure sur une multitude d'échantillons et qui est non destructive. Ce mémoire par articles est divisé en quatre parties, dont les parties deux A quatre présentant les articles publiés et soumis. La première partie présente l'état des connaissances dans la matière nécessaires à l'acomplissement de ce projet de maîtrise. Les principaux sujets traités portent sur les matériaux composites, propagation d'ondes, la modélisation des ondes guidées, la caractérisation par ondes guidées et la surveillance embarquée des structures. La deuxième partie présente une étude de l'effet des propriétés mécaniques sur la performance de l'algorithme d'imagerie Excitelet. L'étude est faite sur une structure isotrope. Les résultats ont démontré que l'algorithme est sensible à l'exactitude des propriétés mécaniques utilisées dans le modèle. Cette

  4. Les enjuex éthiques entourant la recherche en santé sur les enfants

    PubMed Central

    2008-01-01

    RÉSUMÉ La recherche en santé est un devoir moral parce qu’elle est la base des soins probants prodigués par tous les dispensateurs de soins. Des politiques et des règlements précis régissent la tenue des recherches sur des humains. Il faut procéder à une évaluation éthique d’un projet de recherche donné avant de pouvoir l’entreprendre. La recherche sur les enfants pose d’énormes défis en matière de consentement éclairé et d’assentiment, de vulnérabilité et de potentiel de conflit d’intérêts (CDI). Les chercheurs en santé pédiatrique devraient prôner la participation des enfants à la recherche, tout en se montrant attentifs à en limiter les risques.

  5. Adsorption de gaz sur les materiaux microporeux modelisation, thermodynamique et applications

    NASA Astrophysics Data System (ADS)

    Richard, Marc-Andre

    2009-12-01

    Nos travaux sur l'adsorption de gaz dans les materiaux microporeux s'inscrivent dans le cadre des recherches visant a augmenter l'efficacite du stockage de l'hydrogene a bord des vehicules. Notre objectif etait d'etudier la possibilite d'utiliser l'adsorption afin d'ameliorer l'efficacite de la liquefaction de l'hydrogene des systemes a petite echelle. Nous avons egalement evalue les performances d'un systeme de stockage cryogenique de l'hydrogene base sur la physisorption. Comme nous avons affaire a des plages de temperatures particulierement etendues et a de hautes pressions dans la region supercritique du gaz, nous avons du commencer par travailler sur la modelisation et la thermodynamique de l'adsorption. La representation de la quantite de gaz adsorbee en fonction de la temperature et de la pression par un modele semi-empirique est un outil utile pour determiner la masse de gaz adsorbee dans un systeme mais egalement pour calculer les effets thermiques lies a l'adsorption. Nous avons adapte le modele Dubinin-Astakhov (D-A) pour modeliser des isothermes d'adsorption d'hydrogene, d'azote et de methane sur du charbon actif a haute pression et sur une grande plage de temperatures supercritiques en considerant un volume d'adsorption invariant. Avec cinq parametres de regression (incluant le volume d'adsorption Va), le modele que nous avons developpe permet de tres bien representer des isothermes experimentales d'adsorption d'hydrogene (de 30 a 293 K, jusqu'a 6 MPa), d'azote (de 93 a 298 K, jusqu'a 6 MPa) et de methane (de 243 a 333 K, jusqu'a 9 MPa) sur le charbon actif. Nous avons calcule l'energie interne de la phase adsorbee a partir du modele en nous servant de la thermodynamique des solutions sans negliger le volume d'adsorption. Par la suite, nous avons presente les equations de conservation de la niasse et de l'energie pour un systeme d'adsorption et valide notre demarche en comparant des simulations et des tests d'adsorption et de desorption. En plus de l

  6. The optimization research of the multi-response problems based on the SUR.

    PubMed

    Su, Haitao; Yao, Hong Mei; Zeng, Hui

    2015-03-01

    In the optimization design of products and processes in the biological medicine, we need to consider multiple characteristics of quality simultaneously, namely multi-response problems, multi-response optimization design can improve the quality of the products effectively, and realize enormous economic benefits and so multi-response optimization design is showing a more and more important role in continuous quality improvement activities. But usually there is no specific set of input variables to make all the response variables be optimal, and the traditional multi-response surface method cannot solve the correlation problem between multi-responses and regression model problem effectively. Because we can make a better fitting model and solve the problem of the correlation between the response variables at the same time with SUR method, this thesis uses the SUR method to model the relationship between each response and control variables, and makes predictions; confirms the satisfaction function of each response and the overall satisfaction function; combines with practical problems of a company in biological medicine field named SX to conduct empirical research, this thesis confirms the optimal factor level combination with the overall satisfaction function in the end, thus solves the multi-response optimization problems.

  7. Volvulus du grêle sur paquet d’ascaris: à propos d’un cas

    PubMed Central

    Diouf, Cheikh; Kane, Ahmed; Ndoye, Ndeye Aby; Ndour, Oumar; Faye-Fall, Aimé Lakh; Fall, Mbaye; Alumeti, Désiré Munyali; Ngom, Gabriel

    2016-01-01

    Nous rapportons un cas exceptionnel de volvulus nécrosé de l'intestin grêle dû à des ascaris adultes chez un enfant de 7 ans. A l'admission, l'enfant présentait le tableau d'occlusion intestinale qui évoluait depuis deux jours avec altération de l'état général. La radiographie de l'abdomen sans préparation retrouvait des niveaux hydroaériques de type grêlique et un aspect tigré évoquant le diagnostic d'une occlusion intestinale haute sur masse abdominale. Après la réanimation, le traitement chirurgical consistait en une laparotomie qui avait retrouvé un volvulus nécrosé de l'iléon terminale contenant des ascaris adultes. Une résection du grêle sur environ un mètre emportant le segment nécrosé suivie d'une iléostomie était réalisée. L'évolution a été favorable, l'anastomose iléo-colique fut réalisée quatre semaines plus tard. Au recul de deux ans l'enfant est indemne de tout symptôme. PMID:27795803

  8. Visual Analysis and Dissemination of Scientific Literature Collections with SurVis.

    PubMed

    Beck, Fabian; Koch, Sebastian; Weiskopf, Daniel

    2016-01-01

    Bibliographic data such as collections of scientific articles and citation networks have been studied extensively in information visualization and visual analytics research. Powerful systems have been built to support various types of bibliographic analysis, but they require some training and cannot be used to disseminate the insights gained. In contrast, we focused on developing a more accessible visual analytics system, called SurVis, that is ready to disseminate a carefully surveyed literature collection. The authors of a survey may use our Web-based system to structure and analyze their literature database. Later, readers of the survey can obtain an overview, quickly retrieve specific publications, and reproduce or extend the original bibliographic analysis. Our system employs a set of selectors that enable users to filter and browse the literature collection as well as to control interactive visualizations. The versatile selector concept includes selectors for textual search, filtering by keywords and meta-information, selection and clustering of similar publications, and following citation links. Agreement to the selector is represented by word-sized sparkline visualizations seamlessly integrated into the user interface. Based on an analysis of the analytical reasoning process, we derived requirements for the system. We developed the system in a formative way involving other researchers writing literature surveys. A questionnaire study with 14 visual analytics experts confirms that SurVis meets the initially formulated requirements.

  9. Evaluation des connaissances des parents sur les bronchiolites aiguës

    PubMed Central

    Gueddari, Widad; Tazi, Abderrahmane; Ouardi, Amine; Nani, Samira; Zineddine, Abdelhadi

    2014-01-01

    Les infections respiratoires (IR) constituent la deuxième cause de mortalité infantile au Maroc, dû en partie à l'absence d'information et de sensibilisation. Le but de ce travail était d’évaluer les connaissances des parents sur la bronchiolite aiguë, infection respiratoire très fréquente. Nous avons réalisé une enquête basée sur un questionnaire, auprès de parents de nourrissons consultants pour toux, avec ou sans gêne respiratoire. 180 parents ont été inclus dans l’étude. Les parents pensaient que l'infection respiratoire était secondaire au climat froid (96%); seuls 4% ont évoqué une origine infectieuse. Aucun des parents ne savait que le lavage des mains était un moyen de prévention de la transmission. Les parents ont majoritairement répondu que la kinésithérapie respiratoire ne servait à rien (65%), et qu'elle était nocive (24.5%). Ce manque de connaissances fondamentales en matière d'IR et de bronchiolite en particulier, devrait inciter à entreprendre un programme de sensibilisation PMID:25328606

  10. Implementation of tsunami disaster prevention measures in the municipality of San Rafael del Sur, Nicaragua

    NASA Astrophysics Data System (ADS)

    Strauch, W.; Talavera, E.; Acosta, N.; Sanchez, M.; Mejia, E.

    2007-05-01

    The Nicaraguan Pacific coast presents considerable tsunami risk. On September 1, 1992, a tsunami caused enormous damage in the infrastructure and killed more than 170 people. A pilot project was conducted between 2006 and 2007 in the municipality of San Rafel del Sur, area of Masachapa, The project included multiple topics of tsunami prevention measures and considering the direct participation of the local population, as: -General education on disaster prevention, participative events; -Investigation of awareness level and information needs for different population groups; -Specific educational measures in the schools; -Publication of brochures, calendars, news paper articles, radio programs, TV spots -Development of local tsunami hazard maps, 1:5,000 scale; (based on previous regional tsunami hazard mapping projects and local participation) -Development of a tsunami warning plan; -Improvements of the national tsunami warning system. -Installation of sirens for tsunami warning -Installation of tsunami signs, indicating hazardous areas, evacuation routes, safe places; -Realization of evacuation drills in schools. Based on the experiences gained in Masachapa it is planned to run similar projects in other areas along the Nicaraguan Pacific coast. In the project participated the local municipality and local stakeholders of San Rafael del Sur, Ministry of Education, National Police, Nicaraguan Red Cross, Ministry of Health, Ministry of Tourism, Nicaraguan Geosciences Institute (INETER), National System for Disaster Prevention (SINAPRED), Swiss Agency for Development and Cooperation (SDC). It was financed by SDC and INETER.

  11. Cancer du sein sur tissu mammaire ectopique: à propos de 2 cas

    PubMed Central

    Haddad, Houssam; Bourhaleb, Zouhour; El Harroudi, Tijani; Mezouar, Loubna; El Hfid, Mohamed

    2012-01-01

    Le cancer du sein sur tissu mammaire ectopique est une tumeur rare qui représente 0,2 à 0,6% de l′ensemble des cancers du sein. Les auteurs en rapportent 2 cas pris en charge dans 2 centres d′oncologie marocains. Il s′agit de 2 patientes âgées de 31 ans et 47 ans présentant un cancer du sein sur tissu mammaire ectopique en situation axillaire. Une tumorectomie avec curage ganglionnaire axillaire homolatéral a été réalisée chez les 2 patientes dont une après une chimiothérapie néoadjuvante. Le traitement adjuvant a compris une chimiothérapie, radiothérapie puis une hormonothérapie. Après un recul de 12 mois et 20 mois respectivement, les 2 patientes sont en rémission complète. PMID:23330041

  12. Impact de la preparation des anodes crues et des conditions de cuisson sur la fissuration dans des anodes denses

    NASA Astrophysics Data System (ADS)

    Amrani, Salah

    La fabrication de l'aluminium est realisee dans une cellule d'electrolyse, et cette operation utilise des anodes en carbone. L'evaluation de la qualite de ces anodes reste indispensable avant leur utilisation. La presence des fissures dans les anodes provoque une perturbation du procede l'electrolyse et une diminution de sa performance. Ce projet a ete entrepris pour determiner l'impact des differents parametres de procedes de fabrication des anodes sur la fissuration des anodes denses. Ces parametres incluent ceux de la fabrication des anodes crues, des proprietes des matieres premieres et de la cuisson. Une recherche bibliographique a ete effectuee sur tous les aspects de la fissuration des anodes en carbone pour compiler les travaux anterieurs. Une methodologie detaillee a ete mise au point pour faciliter le deroulement des travaux et atteindre les objectifs vises. La majorite de ce document est reservee pour la discussion des resultats obtenus au laboratoire de l'UQAC et au niveau industriel. Concernant les etudes realisees a l'UQAC, une partie des travaux experimentaux est reservee a la recherche des differents mecanismes de fissuration dans les anodes denses utilisees dans l'industrie d'aluminium. L'approche etait d'abord basee sur la caracterisation qualitative du mecanisme de la fissuration en surface et en profondeur. Puis, une caracterisation quantitative a ete realisee pour la determination de la distribution de la largeur de la fissure sur toute sa longueur, ainsi que le pourcentage de sa surface par rapport a la surface totale de l'echantillon. Cette etude a ete realisee par le biais de la technique d'analyse d'image utilisee pour caracteriser la fissuration d'un echantillon d'anode cuite. L'analyse surfacique et en profondeur de cet echantillon a permis de voir clairement la formation des fissures sur une grande partie de la surface analysee. L'autre partie des travaux est basee sur la caracterisation des defauts dans des echantillons d'anodes crues

  13. Prevalence of infection with Toxoplasma gondii in landrace and mixed breed pigs slaughtered in Baja California Sur state, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purpose We performed a cross-sectional study to determine the seroprevalence of Toxoplasma gondii infection in 308 domestic pigs slaughtered in La Paz, Baja California Sur State, Mexico using the modified agglutination test (MAT, cut off 1:25). Results Forty (13%) of the 308 pigs were seropositive ...

  14. Effets de la pollution de l’air sur la santé

    PubMed Central

    Abelsohn, Alan; Stieb, Dave M.

    2011-01-01

    Résumé Objectif Faire connaître aux médecins de famille les effets de la pollution atmosphérique sur la santé et indiquer quels conseils donner aux patients vulnérables pour qu’ils soient moins exposés. Sources de l’information On a consulté MEDLINE à l’aide des termes relatifs à la pollution atmosphérique et à ses effets indésirables. On a révisé les articles en anglais publiés entre janvier 2008 et décembre 2009. La plupart des études contenaient des preuves de niveau II. Principal message Au Canada, la pollution de l’air extérieur cause une morbidité et une mortalité importantes. Elle peut affecter le système respiratoire (exacerbation de l’asthme et de la maladie pulmonaire obstructive chronique) et le système cardiovasculaire (déclencher l’arythmie, l’insuffisance cardiaque et les AVC). La cote air santé (CAS) est un nouvel outil de communication mis au point par Santé Canada et Environnement Canada qui indique sur une échelle de 1 à 10, le risque pour la santé causé par la pollution atmosphérique. La CAS est largement diffusée dans les médias et cet outil pourrait être utile au médecin de famille pour inciter les patients à haut risque (comme ceux qui souffrent d’asthme, de maladie pulmonaire obstructive chronique ou d’insuffisance cardiaque) à réduire leur exposition à la pollution atmosphérique. Conclusion Le médecin de famille peut se servir de la CAS et de ses messages sur la santé pour enseigner aux asthmatiques et aux autres patients à risque élevé la façon de réduire les risques pour la santé causés par la pollution atmosphérique.

  15. Late Cardiac Events after Childhood Cancer: Methodological Aspects of the Pan-European Study PanCareSurFup

    PubMed Central

    Feijen, Elizabeth A. M.; Font-Gonzalez, Anna; van Dalen, Elvira C.; van der Pal, Helena J. H.; Reulen, Raoul C.; Winter, David L.; Kuehni, Claudia E.; Haupt, Riccardo; Alessi, Daniela; Byrne, Julianne; Bardi, Edit; Jakab, Zsuzsanna; Grabow, Desiree; Garwicz, Stanislaw; Jankovic, Momcilo; Levitt, Gill A.; Skinner, Roderick; Zadravec Zaletel, Lorna; Hjorth, Lars; Tissing, Wim J. E.; de Vathaire, Florent; Hawkins, Mike M.; Kremer, Leontien C. M.

    2016-01-01

    Background and Aim Childhood cancer survivors are at high risk of long-term adverse effects of cancer and its treatment, including cardiac events. The pan-European PanCareSurFup study determined the incidence and risk factors for cardiac events among childhood cancer survivors. The aim of this article is to describe the methodology of the cardiac cohort and nested case-control study within PanCareSurFup. Methods Eight data providers in Europe participating in PanCareSurFup identified and validated symptomatic cardiac events in their cohorts of childhood cancer survivors. Data on symptomatic heart failure, ischemia, pericarditis, valvular disease and arrhythmia were collected and graded according to the Criteria for Adverse Events. Detailed treatment data, data on potential confounders, lifestyle related risk factors and general health problems were collected. Results The PanCareSurFup cardiac cohort consisted of 59,915 5-year childhood cancer survivors with malignancies diagnosed between 1940 and 2009 and classified according to the International Classification of Childhood Cancer 3. Different strategies were used to identify cardiac events such as record linkage to population/ hospital or regional based databases, and patient- and general practitioner-based questionnaires. Conclusion The cardiac study of the European collaborative research project PanCareSurFup will provide the largest cohort of 5-year childhood cancer survivors with systematically ascertained and validated data on symptomatic cardiac events. The result of this study can provide information to minimize the burden of cardiac events in childhood cancer survivors by tailoring the follow-up of childhood cancer survivors at high risk of cardiac adverse events, transferring this knowledge into evidence-based clinical practice guidelines and providing a platform for future research studies in childhood cancer patients.  PMID:27643694

  16. Ophthalmic Combination of SurR9-C84A and Trichostatin-A Targeting Molecular Pathogenesis of Alkali Burn

    PubMed Central

    Roy, Kislay; Sriramoju, Bhasker; Kanwar, Rupinder K.; Kanwar, Jagat R.

    2016-01-01

    Background: Alkali burn is a frequently occurring ocular injury that resembles ocular inflammation caused by eye allergies, infection, and refractive surgeries. Methods: We investigated the synergistic regenerative potential of dominant negative survivin mutant (SurR9-C84A) and histone deacetylase (HDAC) inhibitor trichostatin-A (TSA) against alkali burn and corneal haze using human keratocytes and rabbit alkali burn model (Female New Zealand white rabbits). Results: Combination of SurR9-C84A and TSA suppressed levels of transforming growth factor (TGF)-β, alpha smooth-muscle actin (α-SMA), fibronectin and HDAC1, leading to apoptosis in myofibroblast cells and, showed the potential to clear the corneal haze. An insult with 0.5 N NaOH for 1 min led to neutrophils infiltration and formation of large vacuoles in the stroma. Treatments with TSA and SurR9-C84A for 40 min led to improvement in the conjunctival and corneal tissue integrity, marked by an increase in clathrin, and claudin expressions. An increase in TGF-β and endogenous survivin confirmed wound healing and cell proliferation in rabbit cornea. The blood analysis revealed a substantial decrease in the RBC, WBC, platelets, or the hemoglobin content post alkali burn. The cytokine array analysis revealed that NaOH induced expressions of IL-1α and MMP-9, which were found to be significantly downregulated (1.8 and 11.5 fold respectively) by the combinatorial treatment of SurR9-C84A and TSA. Conclusion: Our results confirmed that combination of SurR9-C84A with TSA worked in synergy to heal ocular injury and inflammations due to alkali burn and led to the regeneration of ocular tissue by increasing clathrin, claudin, survivin, and TGF-β and reversal of alkali burn by suppressing IL-1α and MMP-9 without inducing haze. PMID:27516741

  17. The Periplasmic Bacterial Molecular Chaperone SurA Adapts Its Structure to Bind Peptides in Different Conformations to Assert a Sequence Preference for Aromatic Residues

    SciTech Connect

    Xu, X.; Wang, S.; Hu, Y.-X.; McKay, D.B.

    2009-06-04

    The periplasmic molecular chaperone protein SurA facilitates correct folding and maturation of outer membrane proteins in Gram-negative bacteria. It preferentially binds peptides that have a high fraction of aromatic amino acids. Phage display selections, isothermal titration calorimetry and crystallographic structure determination have been used to elucidate the basis of the binding specificity. The peptide recognition is imparted by the first peptidyl-prolyl isomerase (PPIase) domain of SurA. Crystal structures of complexes between peptides of sequence WEYIPNV and NFTLKFWDIFRK with the first PPIase domain of the Escherichia coli SurA protein at 1.3 A resolution, and of a complex between the dodecapeptide and a SurA fragment lacking the second PPIase domain at 3.4 A resolution, have been solved. SurA binds as a monomer to the heptapeptide in an extended conformation. It binds as a dimer to the dodecapeptide in an alpha-helical conformation, predicated on a substantial structural rearrangement of the SurA protein. In both cases, side-chains of aromatic residues of the peptides contribute a large fraction of the binding interactions. SurA therefore asserts a recognition preference for aromatic amino acids in a variety of sequence configurations by adopting alternative tertiary and quaternary structures to bind peptides in different conformations.

  18. Experiential environmental learning: A case study of innovative pedagogy in Baja Sur, Mexico

    NASA Astrophysics Data System (ADS)

    Schneller, Andrew Jon

    This mixed methods case study describes an innovative two-semester middle school environmental learning course that departs from traditional Mexican expository pedagogy through the incorporation of experiential and service learning. This research takes place in a small middle school in Pescadero, Baja California Sur, Mexico. The research approach utilized in the study adds to the handful of studies in this cross-disciplinary field by employing quantitative methodologies to measure course outcomes on student environmental knowledge, perceptions, and actions, while simultaneously qualitatively describing the behavioral, educational, environmental, and social experiences of students. This research employs Dewey's theories of experience---as well as those of more contemporary authenticity theorists---in order to identify the philosophies that advocate incorporating experiential pedagogy within the curriculum. Implications for Mexican educational policy, practical pedagogical applications, and theory are discussed.

  19. Metal concentrations in demersal fish species from Santa Maria Bay, Baja California Sur, Mexico (Pacific coast).

    PubMed

    Jonathan, M P; Aurioles-Gamboa, David; Villegas, Lorena Elizabeth Campos; Bohórquez-Herrera, Jimena; Hernández-Camacho, Claudia J; Sujitha, S B

    2015-10-15

    Concentrations of 11 trace metals (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd, As, Hg) in 40 fish species from Santa Maria Bay, Baja California Sur, Mexico, the strategically important area for marine mammals and organisms were analyzed. Based on their concentrations the ranking of metals Fe>Zn>Ni>Cr>Mn>Pb>Cu>Co>As>Cd>Hg suggests that organism size, metabolism and feeding habits are correlated with metal concentrations. Local geological formations affect the concentrations of different metals in the aquatic environment and are subsequently transferred to fishes. The correlation analysis suggests that metabolism and nurturing habits impact the concentration of metals. Concentrations of Fe and Mn appear to be influenced by scavenging and absorption processes, which vary by species. The considerable variability in the metal concentrations obtained in different species underscores the importance of regular monitoring.

  20. Recommandations sur l’examen pelvien de dépistage systématique

    PubMed Central

    Tonelli, Marcello; Gorber, Sarah Connor; Moore, Ainsley; Thombs, Brett D.

    2016-01-01

    Résumé Objectif Examiner les lignes directrices de 2014 de l’American College of Physicians (ACP) en matière d’examens pelviens de dépistage du cancer (autre que du col), des maladies inflammatoires pelviennes ou d’autres affections gynécologiques bénignes afin de déterminer si les lignes directrices de l’ACP en matière d’examens pelviens systématiques sont conformes aux normes établies par le Groupe d’étude canadien sur les soins de santé préventifs (GECSSP) et peuvent être adaptées ou adoptées. Méthodologie La méthode SNAP-IT (Smooth National Adaptation and Presentation of Guidelines to Improve Thrombosis Treatment) a servi à déterminer si les lignes directrices de l’ACP étaient conformes aux normes du GECSSP et pouvaient être adaptées ou adoptées. Recommandations Le GECSSP recommande de ne pas effectuer un examen pelvien de dépistage des cancers non cervicaux, des maladies inflammatoires pelviennes ou d’autres affections gynécologiques chez les femmes asymptomatiques. Il s’agit d’une forte recommandation reposant sur des données probantes de qualité modérée. Conclusion Le GECSSP adopte la recommandation en matière d’examen pelvien de dépistage, comme publiée par l’ACP en 2014.

  1. Segundo Catálogo Estelar del Hemisferio Sur con Astrolabio Fotoeléctrico PAII

    NASA Astrophysics Data System (ADS)

    Manrique, W. T.; Podestá, R. C.; Alonso, E.; Actis, E. V.; Pacheco, A. M.; Bustos, G.; Lizhi, L.; Zezhi, W.; Fanmiao, Z.; Hongqi, W.; Perdomo, R.

    Recordamos que entre el Observatorio Astronómico ``Félix Aguilar'', el Observatorio Astronómico de Beijing y el Observatorio Astronómico de La Plata, se ha convenido en desarrollar un Proyecto de Investigación conjunto, para la observación sistemática de estrellas en el Hemisferio Sur, con el objeto de la elaboración de un Catálogo Estelar Global utilizando un Astrolabio Fotoeléctrico PAII del Observatorio de Beijing, que ha sido usado con éxito en la República de China. En este trabajo se presenta el Segundo Catálogo Estelar del Hemisferio Sur, derivado de las observaciones realizadas con el PAII instalado en el OAFA, durante el períiodo Febrero de 1992 a Marzo de 1997. En este lapso se han observado mas de 400000 pasajes estelares, obteniéndose las correcciones Δ α y Δ δ de 5241 estrellas del FK4, FK5, FK5 Ext., SRS, CAMC y GC. Las precisiones medias son del orden de ± 3,2 ms en ascensión recta y ±0."057 en declinación. Rango de magnitudes : 2,0 a 11,5 Rango de declinaciones : -3o a -60o Epoca Media : 1994.9 Se analizan los residuos en función de la magnitud y tipo espectral, correcciones de grupo y frecuencia de distribución Δ α y Δ δ.

  2. Modern carbonate sediments and environments of the LaPaz region, Baja California Sur, Mexico

    SciTech Connect

    Halfar, J.; Ingle, J.C. Jr.; Cruz-Orozco, R.; Godinez-Orta, L.

    1996-12-31

    The Gulf of California represents one of the most productive and unique marginal seas in the world. The mouth of the Gulf captures warm equatorial water while annual wind patterns assure major upwelling of nutrient-rich water leading to a rich marine biota. These conditions have created a wide array of tropical through warm temperate carbonate environments. The most unusual of these environments is located in the La Paz region of Baja California Sur where tropical-subtropical water temperatures and low rainfall have allowed growth of corals, calcareous red algae, and other shelled invertebrates to form a carbonate bank environment. Sampling and mapping transacts in shallow bays north of La Paz and on the adjacent Espiritu Santo island have revealed a full spectrum of subenvironments including mangrove bordered, terrigenous mud dominated coastal zones, which grade into carbonate tidal flats. In addition, single coral heads as well as incipient reef structures constructed by Porites and Pocillopora coral are present in deeper water areas. Coralline red algae, which are increasingly utilized for paleoenvironmental reconstructions, grow in high abundance on coral debris and in soft sediments and turn out to be main contributors to the La Paz carbonates. Analysis of siliciclastic admixtures, grain size and organic carbon content allow a classification of distinct environments. These data are supplemented by an evaluation of benthic foraminiferal zonations and the varying abundance of biogenic constituents. This Baja California Sur carbonate environment holds special relevance for the interpretation of analogous Neogene and Paleogene paleoenvironments marking major paleoclimatic and paleoceanographic events along the Pacific Coast of North America.

  3. Modern carbonate sediments and environments of the LaPaz region, Baja California Sur, Mexico

    SciTech Connect

    Halfar, J.; Ingle, J.C. Jr. ); Cruz-Orozco, R. ); Godinez-Orta, L. )

    1996-01-01

    The Gulf of California represents one of the most productive and unique marginal seas in the world. The mouth of the Gulf captures warm equatorial water while annual wind patterns assure major upwelling of nutrient-rich water leading to a rich marine biota. These conditions have created a wide array of tropical through warm temperate carbonate environments. The most unusual of these environments is located in the La Paz region of Baja California Sur where tropical-subtropical water temperatures and low rainfall have allowed growth of corals, calcareous red algae, and other shelled invertebrates to form a carbonate bank environment. Sampling and mapping transacts in shallow bays north of La Paz and on the adjacent Espiritu Santo island have revealed a full spectrum of subenvironments including mangrove bordered, terrigenous mud dominated coastal zones, which grade into carbonate tidal flats. In addition, single coral heads as well as incipient reef structures constructed by Porites and Pocillopora coral are present in deeper water areas. Coralline red algae, which are increasingly utilized for paleoenvironmental reconstructions, grow in high abundance on coral debris and in soft sediments and turn out to be main contributors to the La Paz carbonates. Analysis of siliciclastic admixtures, grain size and organic carbon content allow a classification of distinct environments. These data are supplemented by an evaluation of benthic foraminiferal zonations and the varying abundance of biogenic constituents. This Baja California Sur carbonate environment holds special relevance for the interpretation of analogous Neogene and Paleogene paleoenvironments marking major paleoclimatic and paleoceanographic events along the Pacific Coast of North America.

  4. Etude Bacteriologique sur 30 Mois dans un Service de Brulés

    PubMed Central

    Chaibdraa, A.; Bentakouk, M.C.

    2008-01-01

    Summary Le pronostic des brûlures est souvent tributaire de complications infectieuses. Les objectifs de cette étude préliminaire rétrospective sont une évaluation de la flore microbienne et ses fluctuations selon la durée d'hospitalisation chez les patients du Centre des brûlés adultes de Annaba (Algérie). Ce travail porte sur 633 prélèvements microbiologiques positifs obtenus entre juin 2003 (inauguration du service) et décembre 2005. Selon le site de prélèvement la répartition est: cutané (78%), hémoculture (9%), prélèvement trachéo-bronchique (4%), uroculture (3%), sonde urinaire (3%), cathéter(3%). Les germes isolés sont: les staphylocoques (58%), les Pseudomonas (20%), le Candida albicans (5%), l'Acinetobacter (3%) et les autres germes (14%). Parmi les staphylocoques et les Pseudomonas recensés, respectivement 19% et 11% sont isolés la première semaine, contre 43% et 52% au-delà de 21 jours. Ces résultats confrontés aux données de la littérature confirment la prédominance du staphylocoque et du Pseudomonas. Le risque de contamination à partir des techniques invasives de réanimation est commun à toutes les équipes. La prolifération bactérienne est en relation avec la durée d'hospitalisation. Ces constatations doivent nous inciter à tirer bénéfice de l'expérience des autres services, en particulier sur les moyens, accessibles, de prévention de l'infection nosocomiale. PMID:21991102

  5. Evaluation d'impact sur la santé et évaluation d'impact sur l'équité en santé : éventail de pratiques et questions de recherche.

    PubMed

    Villeval, Mélanie; Bidault, Elsa; Lang, Thierry

    2016-09-01

    L'Evaluation d'Impact sur la Santé (EIS) se développe au niveau international et est encore au stade émergent en France. Elle vise à évaluer les effets positifs et négatifs potentiels d'un projet, d'un programme ou d'une politique sur la santé. L'objectif est de produire des recommandations en direction des décideurs, afin d'en maximiser les effets positifs et d'en diminuer les effets négatifs. L'EIS est un moyen particulièrement intéressant d'action sur les déterminants de la santé au-delà des comportements individuels et du système de santé. Les politiques de logement, de transport, de solidarité, économiques, etc. ont, en effet, des impacts souvent non prévus sur la santé. Au-delà des effets sur la santé, l'EIS doit aussi permettre d'apprécier la distribution de ces effets dans la population.Si la préoccupation pour l'équité en santé est centrale dans l'EIS, elle reste cependant difficilement traduite en pratique. Face à cette difficulté, des démarches d'évaluation d'impact ont été développées pour renforcer la prise en compte de l'équité à chaque étape de l'EIS ou « Equity Focused Health Impact Assessment », ou prendre en compte les impacts sur les inégalités de santé de façon spécifique. Ainsi, l'Evaluation de l'Impact sur l'Equité en Santé (EIES) semble, par exemple, particulièrement intéressante pour évaluer l'impact sur les inégalités de projets dans le champ sanitaire.L'EIS et l'EIES posent de nombreuses questions de recherche, notamment autour de la réunion, dans une même démarche, du politique, du citoyen et de l'expert. La participation des populations vulnérables potentiellement affectées par la politique évaluée est une valeur centrale de l'EIS, mais pose des questions d'acceptabilité sociale. La collaboration avec les décideurs politiques est également un enjeu majeur. Les difficultés méthodologiques, notamment de quantification des impacts, peuvent constituer des freins à la promotion

  6. Evaluation d'impact sur la santé et évaluation d'impact sur l'équité en santé : éventail de pratiques et questions de recherche.

    PubMed

    Villeval, Mélanie; Bidault, Elsa; Lang, Thierry

    2016-09-01

    L'Evaluation d'Impact sur la Santé (EIS) se développe au niveau international et est encore au stade émergent en France. Elle vise à évaluer les effets positifs et négatifs potentiels d'un projet, d'un programme ou d'une politique sur la santé. L'objectif est de produire des recommandations en direction des décideurs, afin d'en maximiser les effets positifs et d'en diminuer les effets négatifs. L'EIS est un moyen particulièrement intéressant d'action sur les déterminants de la santé au-delà des comportements individuels et du système de santé. Les politiques de logement, de transport, de solidarité, économiques, etc. ont, en effet, des impacts souvent non prévus sur la santé. Au-delà des effets sur la santé, l'EIS doit aussi permettre d'apprécier la distribution de ces effets dans la population.Si la préoccupation pour l'équité en santé est centrale dans l'EIS, elle reste cependant difficilement traduite en pratique. Face à cette difficulté, des démarches d'évaluation d'impact ont été développées pour renforcer la prise en compte de l'équité à chaque étape de l'EIS ou « Equity Focused Health Impact Assessment », ou prendre en compte les impacts sur les inégalités de santé de façon spécifique. Ainsi, l'Evaluation de l'Impact sur l'Equité en Santé (EIES) semble, par exemple, particulièrement intéressante pour évaluer l'impact sur les inégalités de projets dans le champ sanitaire.L'EIS et l'EIES posent de nombreuses questions de recherche, notamment autour de la réunion, dans une même démarche, du politique, du citoyen et de l'expert. La participation des populations vulnérables potentiellement affectées par la politique évaluée est une valeur centrale de l'EIS, mais pose des questions d'acceptabilité sociale. La collaboration avec les décideurs politiques est également un enjeu majeur. Les difficultés méthodologiques, notamment de quantification des impacts, peuvent constituer des freins à la promotion

  7. Thermal-maturity trends within Franciscan rocks near Big Sur, California: Implications for offset along the San Gregorio San Simeon Hosgri fault zone

    NASA Astrophysics Data System (ADS)

    Underwood, Michael B.; Laughland, Matthew M.; Shelton, Kevin L.; Sedlock, Richard L.

    1995-09-01

    Conventional neotectonic interpretations place the Lucia and Point Sur subterranes of the Franciscan subduction complex on opposite sides of the San Gregorio San Simeon Hosgri dextral fault system and connect that system through the Sur fault zone. Our reconstructed paleotemperature contours, however, are not offset across the San Simeon segment, so differential displacement between the subterranes after peak heating appears to have been negligible. One explanation is that dextral slip on the faults has totaled only 5 10 km. A second possibility is that a discrete Hosgri San Simeon segment extends offshore of the amalgamated Point Sur and Lucia subterranes and that an en echelon stepover transfers dextral slip eastward to the San Gregorio Palo Colorado segment. In either case, the Sur fault zone appears to play a relatively insignificant role in the late Cenozoic tectonic evolution of central California.

  8. First record of a louse fly, Stilbometopa impressa (Bigot), and new host for Microlynchia pusilla (Speiser) (Hippoboscidae) from the Cape Region, Baja California Sur, México.

    PubMed

    Llinas, J; Jiménez, M L

    1996-04-01

    Nine of thirty California quail (Callipepla californica achrustera) captured in autumn of 1992, 17 km west of La Paz, Baja California Sur, México, were parasitized by louse flies. We identified eight Microlynchia pusilla and three Stilbometopa impressa from 30 quails in the ratio of 2.75:1. These are the first records of S. impressa for Cape Region and the first time either fly has been reported from the California quail in Baja California Sur. PMID:8722274

  9. Croissance epitaxiale de GaAs sur substrats de Ge par epitaxie par faisceaux chimiques

    NASA Astrophysics Data System (ADS)

    Belanger, Simon

    La situation energetique et les enjeux environnementaux auxquels la societe est confrontee entrainent un interet grandissant pour la production d'electricite a partir de l'energie solaire. Parmi les technologies actuellement disponibles, la filiere du photovoltaique a concentrateur solaire (CPV pour concentrator photovoltaics) possede un rendement superieur et mi potentiel interessant a condition que ses couts de production soient competitifs. La methode d'epitaxie par faisceaux chimiques (CBE pour chemical beam epitaxy) possede plusieurs caracteristiques qui la rendent interessante pour la production a grande echelle de cellules photovoltaiques a jonctions multiples a base de semi-conducteurs III-V. Ce type de cellule possede la meilleure efficacite atteinte a ce jour et est utilise sur les satellites et les systemes photovoltaiques a concentrateur solaire (CPV) les plus efficaces. Une des principales forces de la technique CBE se trouve dans son potentiel d'efficacite d'utilisation des materiaux source qui est superieur a celui de la technique d'epitaxie qui est couramment utilisee pour la production a grande echelle de ces cellules. Ce memoire de maitrise presente les travaux effectues dans le but d'evaluer le potentiel de la technique CBE pour realiser la croissance de couches de GaAs sur des substrats de Ge. Cette croissance constitue la premiere etape de fabrication de nombreux modeles de cellules solaires a haute performance decrites plus haut. La realisation de ce projet a necessite le developpement d'un procede de preparation de surface pour les substrats de germanium, la realisation de nombreuses sceances de croissance epitaxiale et la caracterisation des materiaux obtenus par microscopie optique, microscopie a force atomique (AFM), diffraction des rayons-X a haute resolution (HRXRD), microscopie electronique a transmission (TEM), photoluminescence a basse temperature (LTPL) et spectrometrie de masse des ions secondaires (SIMS). Les experiences ont permis

  10. Lignes directrices canadiennes sur la rhinosinusite bactérienne aiguë

    PubMed Central

    Kaplan, Alan

    2014-01-01

    Résumé Objectif Faire un résumé clinique des lignes directrices canadiennes sur la rhinosinusite bactérienne aiguë (RSBA) qui présente des éléments d’intérêt pour les médecins de famille. Source des données Les auteurs des lignes directrices ont effectué une recherche documentaire systématique et ont rédigé des recommandations. Une cote a été donnée à la fois en fonction de la fiabilité des données probantes et de la solidité des recommandations. On a sollicité les commentaires d’experts en la matière venant de l’extérieur, ainsi que l’aval de sociétés médicales canadiennes (Association pour la microbiologie médicale et l’infectiologie Canada, Société canadienne d’allergie et d’immunologie clinique, Société canadienne d’otorhinolaryngologie et de chirurgie cervicofaciale, Association canadienne des médecins d’urgence et Regroupement canadien des médecins de famille en santé respiratoire). Message principal Le diagnostic de la RSBA repose sur la présence de symptômes particuliers et leur durée; l’imagerie ou une culture n’est pas nécessaire dans les cas peu compliqués. Le traitement dépend de la gravité des symptômes, notamment avec des corticostéroïdes intranasaux (CSIN) recommandés comme monothérapie pour les cas de légers à modérés, quoique leurs bienfaits soient modestes. Le recours à des CSIN accompagnés d’antibiotiques est réservé aux patients qui ne répondent pas aux CSIN après 72 heures et comme traitement initial des patients dont les symptômes sont graves. Le choix de l’antibiotique doit tenir compte du pathogène soupçonné, du risque de résistance, des problèmes concomitants et des tendances locales de la résistance aux antimicrobiens. Des thérapies d’appoint comme l’irrigation nasale avec une solution saline sont recommandées. En présence de cas réfractaires au traitement, d’épisodes récurrents et de signes de complications, on devrait demander une

  11. Structural and functional insights into the stationary-phase survival protein SurE, an important virulence factor of Brucella abortus.

    PubMed

    Tarique, K F; Abdul Rehman, S A; Devi, S; Tomar, Priya; Gourinath, S

    2016-05-01

    The stationary-phase survival protein SurE from Brucella abortus (BaSurE) is a metal-dependent phosphatase that is essential for the survival of this bacterium in the stationary phase of its life cycle. Here, BaSurE has been biochemically characterized and its crystal structure has been determined to a resolution of 1.9 Å. BaSurE was found to be a robust enzyme, showing activity over wide ranges of temperature and pH and with various phosphoester substrates. The active biomolecule is a tetramer and each monomer was found to consist of two domains: an N-terminal domain, which forms an approximate α + β fold, and a C-terminal domain that belongs to the α/β class. The active site lies at the junction of these two domains and was identified by the presence of conserved negatively charged residues and a bound Mg(2+) ion. Comparisons of BaSurE with its homologues have revealed both common features and differences in this class of enzymes. The number and arrangement of some of the equivalent secondary structures, which are seen to differ between BaSurE and its homologues, are responsible for a difference in the size of the active-site area and the overall oligomeric state of this enzyme in other organisms. As it is absent in mammals, it has the potential to be a drug target.

  12. Structural and functional insights into the stationary-phase survival protein SurE, an important virulence factor of Brucella abortus.

    PubMed

    Tarique, K F; Abdul Rehman, S A; Devi, S; Tomar, Priya; Gourinath, S

    2016-05-01

    The stationary-phase survival protein SurE from Brucella abortus (BaSurE) is a metal-dependent phosphatase that is essential for the survival of this bacterium in the stationary phase of its life cycle. Here, BaSurE has been biochemically characterized and its crystal structure has been determined to a resolution of 1.9 Å. BaSurE was found to be a robust enzyme, showing activity over wide ranges of temperature and pH and with various phosphoester substrates. The active biomolecule is a tetramer and each monomer was found to consist of two domains: an N-terminal domain, which forms an approximate α + β fold, and a C-terminal domain that belongs to the α/β class. The active site lies at the junction of these two domains and was identified by the presence of conserved negatively charged residues and a bound Mg(2+) ion. Comparisons of BaSurE with its homologues have revealed both common features and differences in this class of enzymes. The number and arrangement of some of the equivalent secondary structures, which are seen to differ between BaSurE and its homologues, are responsible for a difference in the size of the active-site area and the overall oligomeric state of this enzyme in other organisms. As it is absent in mammals, it has the potential to be a drug target. PMID:27139831

  13. La violence sur les réseaux canadiens de télévision

    PubMed Central

    Paquette, Guy

    2003-01-01

    La question des effets de la violence à la télévision occupe une place très importante dans l’opinion publique depuis les vingt dernières années, et des centaines d’études y ont été consacrées. Plusieurs chercheurs concluent à une influence négative de cette violence sur le comportement. Le public, les diffuseurs et les autorités politiques ont tous endossé l’idée de réduire la quantité totale de violence présentée au petit écran – en particulier dans les émissions accessibles aux enfants. Nous avons analysé un millier d’émissions de fiction présentées entre 1993 et 2001 sur les principaux réseaux généralistes de télévision au Canada : TVA et TQS ainsi que CTV et Global pour les réseaux privés français et anglais, ainsi que Radio-Canada français et anglais pour les réseaux publics. La méthodologie utilisée est l’analyse de contenu classique, où l’acte de violence constitue l’unité d’analyse. Les données recueillies démontrent que la quantité de violence a augmenté régulièrement depuis 1993, malgré la volonté affirmée des télédiffuseurs de présenter une programmation moins violente. C’est le cas du nombre brut d’actes et du nombre d’actes à l’heure, qui est lui aussi en forte croissance. Les réseaux privés véhiculent trois fois plus de violence que les réseaux publics. On constate également qu’une très forte proportion d’actes de violence figure dans des émissions qui commencent avant 21 h, et que de nombreux enfants y sont probablement exposés. Nous signalons finalement la place de plus en plus importante occupée par la violence psychologique. PMID:20020031

  14. Mise à jour sur l’utilisation clinique de la buprénorphine

    PubMed Central

    Ducharme, Simon; Fraser, Ronald; Gill, Kathryn

    2012-01-01

    Résumé Objectif Examiner les données scientifiques actuelles sur la buprénorphine-naloxone pour le traitement des troubles liés aux opioïdes, en insistant sur le contexte des soins primaires. Qualité des données On a fait une recension dans MEDLINE et la base de données Cochrane des synthèses critiques. Les données probantes sont surtout de niveau I. Message principal La buprénorphine est un agoniste partiel des récepteurs μ des opioïdes et un antagoniste des récepteurs κ des opioïdes ayant une longue demi-vie et un potentiel moins grand que la méthadone d’entraîner un usage abusif. Pour une désintoxication, la buprénorphine est au moins équivalente à la méthadone et supérieure à la clonidine. Comme thérapie de substitution, la buprénorphine est clairement supérieure au placebo. La méthadone comporte de légers avantages en ce qui a trait à la rétention en thérapie, mais une approche par étape en utilisant initialement la buprénorphine-naloxone est aussi efficace. Il est possible, sécuritaire et efficace de recourir à la buprénorphine en milieu de soins primaires. On peut obtenir l’autorisation de prescrire de la buprénorphine après avoir suivi une formation en ligne. Conclusion La buprénorphine est un agent sécuritaire et efficace pour la désintoxication en cas de dépendance aux opioïdes. Elle peut servir d’agent de première intention dans les programmes de thérapie de substitution, en raison de son potentiel plus faible d’usage abusif en comparaison d’autres opioïdes. Son efficacité en milieux de soins primaires en fait un outil thérapeutique utile pour les médecins de famille.

  15. Enquete sur les aspects toxicologiques de la phytotherapie utilisee par un herboriste à Fes, Maroc

    PubMed Central

    Zeggwagh, Ali Amine; Lahlou, Younes; Bousliman, Yassir

    2013-01-01

    Introduction Dans le but d'étudier l'aspect toxicologique des plantes médicinales utilisées en médecine traditionnelle, une étude ethnobotanique a été réalisée à la ville de Fès au centre du Maroc. Méthodes Ont été inclus dans l'étude tous les patients ayant bénéficié d'une prescription par l'herboriste de plantes à visée thérapeutique. La discussion de nos résultats s'est faite sur la base d'une revue de la littérature avec identification des principales plantes toxiques utilisées en phytothérapie au Maroc. L'approche bibliographique a permis de compléter les informations. Résultats L'âge moyen des patients traités par des plantes (38 femmes, 32 hommes) était de 35 ± 18 ans. L'enquête ethnobotanique à révélé que la majorité des plantes médicinales étaient utilisées contre les affections urinaires (21%), suivi des maladies de l'appareil digestif (19.6%) et des maladies rhumatologiques (18.2%). Le nombre de plantes prescrits par l'herboriste a été de 53 dont 5 sont potentiellement toxiques. L'identification taxonomique des plantes prescrites a recensé 30 familles dont les plus représentées sont les Lamiaceae (23.33%), les Apiaceae (13,33%) et les Asteraceae (10%). La prescription des plantes considérées comme toxiques a concerné 7,1% des consultants traités par les plantes médicinales. Aucune complication inhérente aux plantes prescrites n'a été déplorée. Conclusion Malgré les résultats encourageants de notre enquête sur le compte de la phytothérapie, la pratique de la phytothérapie est laissée à la vulgarisation et à l'oubli scientifique, législatif et universitaire. PMID:23734270

  16. Bio-optical profile data report coastal transition zone program, R/V Point Sur, June 15-28, 1987

    NASA Technical Reports Server (NTRS)

    Davis, Curtiss O.; Rhea, W. Joseph

    1990-01-01

    Twenty vertical profiles of the bio-optical properties of the ocean were made during a research cruise on the R/V Point Sur, June 15 to 28, 1987, as part of the Coastal Transition Zone Program off Point Arena, California. Extracted chlorophyll values were also measured at some stations to provide calibration data for the in situ fluorometer. This summary provides investigators with an overview of the data collected. The entire data set is available in digital form.

  17. Map showing coastal cliff retreat rates along the Big Sur coast, Monterey and San Luis Obispo Counties, California

    USGS Publications Warehouse

    Hapke, Cheryl J.; Green, Krystal R.

    2004-01-01

    The average coastal cliff retreat rate along the Big Sur coast is 18 ? 6 cm/yr as measured over a 52-year time period. The erosion reference features measured as the cliff edge include the well-defined cliff edges common to marine terraces, slight breaks in the slope defining the upper edge of the active lower slope, and the road grade. Cliff erosion and retreat are focused in isolated erosion hotspots that account for most of the calculated average retreat.

  18. Abdomen aigu sur une torsion de rate ectopique: à propos d'un cas

    PubMed Central

    Khalid, Elhattabi; Fatimazahra, Bensardi; Rachid, Lefriyekh; Abdelaziz, Fadil; Mohamed, Lahkim; Nadia, Benissa; Driss, Khaiz; Saad, Berrada; Najib, Zerouali Ouariti

    2012-01-01

    La rate ectopique est une entité rare dont l'incidence est mal connue. La torsion de son pédicule est une complication grave, qui doit bénéficier d'un diagnostic précoce; évitant ainsi la splénectomie surtout chez des patients jeunes. Nous rapportons le cas d'une patiente âgée de 39 ans; admise aux urgences dans un tableau d'abdomen aigu chirurgical, l'examen clinique, l’échographie et la tomodensitométrie abdominale ont contribué au diagnostic de torsion d'une rate ectopique en position hypogastrique, la splénectomie a été réalisée devant la découverte peropératoire de taches de nécrose sur la rate tordue. Le diagnostic de torsion d'une rate ectopique doit être suspecté devant l'association d'un abdomen aigu et la palpation d'une masse abdominale. L’échographie et la tomodensitométrie abdominale confirment le diagnostic. Le traitement est chirurgical; il consiste en une splénopexie qui est plus approprié. En présence de nécrose, la splénectomie doit être réalisée aussi bien par voie laparoscopique que par laparotomie. PMID:22655096

  19. The two Coissac's novels : l'Envol and Sur la Lune

    NASA Astrophysics Data System (ADS)

    Villain, Jacques

    2002-01-01

    Coissac wrote two novels with his friend Charles Rouch.: "L'Envol" in 1934 and "Sur la Lune" in 1935. In these books he describes the preparation of the lunar rocket weigthing 3000 tons and powered by solid propellants. This rocket is launched from a base built at the top of a peruvian volcano. The seven men crew (5 french and one american) is sent to the Moon in a 45 tons command module from which two lunar modules can be separated and can descent to the lunar surface. Coissac describes along the trajectory the means to guide and control the rocket. The exploration of the Moon is done with bicycles ans suits. The explorers meet strange animals and strange people living under ground like termites in perfect love and happiness. After having explored the two faces of the Moon, the lunar modules leave the Moon for a docking with the main vehicle waiting on a lunar orbit and the crew comes back to the Earth. The spacecraft lands in the Pacific Ocean. Except the direct flight from Earth to the Moon, the travel to the Moon proposed by Coissac is very similar to that of Apollo but more than thirty years earlier.

  20. The Reality of Neandertal Symbolic Behavior at the Grotte du Renne, Arcy-sur-Cure, France

    PubMed Central

    Caron, François; d'Errico, Francesco; Del Moral, Pierre; Santos, Frédéric; Zilhão, João

    2011-01-01

    Background The question of whether symbolically mediated behavior is exclusive to modern humans or shared with anatomically archaic populations such as the Neandertals is hotly debated. At the Grotte du Renne, Arcy-sur-Cure, France, the Châtelperronian levels contain Neandertal remains and large numbers of personal ornaments, decorated bone tools and colorants, but it has been suggested that this association reflects intrusion of the symbolic artifacts from the overlying Protoaurignacian and/or of the Neandertal remains from the underlying Mousterian. Methodology/Principal Findings We tested these hypotheses against the horizontal and vertical distributions of the various categories of diagnostic finds and statistically assessed the probability that the Châtelperronian levels are of mixed composition. Our results reject that the associations result from large or small scale, localized or generalized post-depositional displacement, and they imply that incomplete sample decontamination is the parsimonious explanation for the stratigraphic anomalies seen in the radiocarbon dating of the sequence. Conclusions/Significance The symbolic artifacts in the Châtelperronian of the Grotte du Renne are indeed Neandertal material culture. PMID:21738702

  1. Relevamiento total del hemisferio sur celeste en la frecuencia de 1420 MHz

    NASA Astrophysics Data System (ADS)

    Bava, J. A.; Colomb, F. R.; Hurrel, E.; Larrarte, J. J.; Sanz, A. J.; Testori, J. C.; Reich, P.; Reich, W.; Wielebinski, R.

    En el presente artículo se describe el relevamiento del cielo en el Hemisferio Sur Celeste en la frecuencia de 1420 MHz para declinaciones δ<= -19o realizado con la Antena II de 30 metros de diámetro del IAR. Este relevamiento posee igual sensibilidad (3xr.m.s=50 mK) que el realizado en el Hemisferio Norte con el radiotelescopio de 25 metros de Stockert de la Universidad de Bonn, operado por el Max-Planck Institute für Radioastronomie ( Reich W., 1982, A&ASS 48, 219; Reich P. and Reich W., 1986, A&ASS 63, 205). Con los datos obtenidos por ambos radiotelescopios se posee una base de datos de todo el cielo en esta frecuencia. En esta publicación presentamos los detalles del sistema receptor, técnicas de observación y reducción de datos, calibración y discusión de los errores en los resultados.

  2. Isostatic gravity map of the Point Sur 30 x 60 quadrangle and adjacent areas, California

    USGS Publications Warehouse

    Watt, J.T.; Morin, R.L.; Langenheim, V.E.

    2011-01-01

    This isostatic residual gravity map is part of a regional effort to investigate the tectonics and water resources of the central Coast Range. This map serves as a basis for modeling the shape of basins and for determining the location and geometry of faults in the area. Local spatial variations in the Earth's gravity field (after removing variations caused by instrument drift, earth-tides, latitude, elevation, terrain, and deep crustal structure), as expressed by the isostatic anomaly, reflect the distribution of densities in the mid- to upper crust, which in turn can be related to rock type. Steep gradients in the isostatic gravity field often indicate lithologic or structural boundaries. Gravity highs reflect the Mesozoic granitic and Franciscan Complex basement rocks that comprise both the northwest-trending Santa Lucia and Gabilan Ranges, whereas gravity lows in Salinas Valley and the offshore basins reflect the thick accumulations of low-density alluvial and marine sediment. Gravity lows also occur where there are thick deposits of low-density Monterey Formation in the hills southeast of Arroyo Seco (>2 km, Marion, 1986). Within the map area, isostatic residual gravity values range from approximately -60 mGal offshore in the northern part of the Sur basin to approximately 22 mGal in the Santa Lucia Range.

  3. Uranium-series ages of marine terraces, La Paz Peninsula, Baja California Sur, Mexico

    USGS Publications Warehouse

    Sirkin, L.; Szabo, B. J.; Padilla, G.A.; Pedrin, S.A.; Diaz, E.R.

    1990-01-01

    Uranium-series dating of coral samples from raised marine terrace deposits between 1.5 and 10 m above sea level in the La Paz Peninsula area, Baja California Sur, yielded ages between 123 ka and 138 ka that are in agreement with previously reported results. The stratigraphy and ages of marine units near the El Coyote Arroyo indicate the presence of two high stands of the sea during the last interglacial or oxygen isotope substage 5e at about 140 ka and 123 ka. Accepting 5 m for the sea level during the last interglacial transgression, we calculate average uplift rates for the marine terraces of about ???70 mm/ka and 40 mm/ka. These slow rates of uplift indicate a relative stability of the La Paz peninsula area for the past 140 000 years. In contrast, areas of Baja California affected by major faultf experienced higher rates of uplift. Rockwell et al. (1987) reported vertical uplift rates of 180 to 300 mm/ka at Punta Banda within the Aqua Blanea fault zone in northern Baja California. ?? 1990 Springer-Verlag.

  4. Geothermal Exploration Using Remote Sensing in the South of Baja California Sur, Mexico

    NASA Astrophysics Data System (ADS)

    Báncora, Cristina; Prol-Ledesma, Rosa María

    2008-05-01

    The area from Ciudad Constitución to Los Cabos in Baja California Sur was studied using a mosaic of four Landsat ETM+images. The main objective was to define favorable areas for utilization and exploitation of geothermal energy. The approach was to spectrally and spatially enhance the images to define characteristics related with geothermal activity, as are the presence of altered rock and main geological structures. The products of hydrothermal alteration are minerals that belong to two main groups: oxides and hydroxyls. Therefore, image processing is necessary to enhance oxides and hydroxyls spectral features and subdue the vegetation spectral characteristics. The band subtraction (4-3, 3-1, 5-7) gave the finest results due to the fact that it is a linear equation that does not cause loss of information when it is stretched. A color composite was done with these three layers and after a detailed visual analysis three areas were point out to be prospective to contain hydrothermal activity.

  5. Influence of Carbonate Crusts on Trophic Cascades in Big Sur Streams.

    NASA Astrophysics Data System (ADS)

    Rundio, D.; Lindley, S.

    2005-05-01

    Top-down effects of fish predation in streams are influenced by habitat conditions and traits of intermediate consumers. Along the Big Sur coast, seasonal carbonate crusts form in many streams, and appear to alter insect communities. We conducted a small-scale field experiment in two adjacent tributaries (crusted and crust-free) to determine the effects of predation by juvenile steelhead (Oncorhynchus mykiss) on invertebrates and algae in these different stream types. We hypothesized that a trophic cascade would be more likely in the crusted stream, which was dominated by an herbivore vulnerable to steelhead predation (Baetis), than in the crust-free stream, which was dominated by a less vulnerable herbivore (Agapetus). However, excluding steelhead from paving bricks had no effect on algae or Baetis in the crusted stream. Algal abundance was low, suggesting possible bottom-up control. In the crust-free stream, steelhead predation did not affect Agapetus, but nevertheless produced a trophic cascade by causing Baetis to increase by 85%, which in turn depressed algae by 25%. These results suggest that trophic interactions may differ between crust forming and non-crust forming streams, which we plan to test with additional sampling and experiments replicated across stream types.

  6. Modelisation de la diffusion sur les surfaces metalliques: De l'adatome aux processus de croissance

    NASA Astrophysics Data System (ADS)

    Boisvert, Ghyslain

    Cette these est consacree a l'etude des processus de diffusion en surface dans le but ultime de comprendre, et de modeliser, la croissance d'une couche mince. L'importance de bien mai triser la croissance est primordiale compte tenu de son role dans la miniaturisation des circuits electroniques. Nous etudions ici les surface des metaux nobles et de ceux de la fin de la serie de transition. Dans un premier temps, nous nous interessons a la diffusion d'un simple adatome sur une surface metallique. Nous avons, entre autres, mis en evidence l'apparition d'une correlation entre evenements successifs lorsque la temperature est comparable a la barriere de diffusion, i.e., la diffusion ne peut pas etre associee a une marche aleatoire. Nous proposons un modele phenomenologique simple qui reproduit bien les resultats des simulations. Ces calculs nous ont aussi permis de montrer que la diffusion obeit a la loi de Meyer-Neldel. Cette loi stipule que, pour un processus active, le prefacteur augmente exponentiellement avec la barriere. En plus, ce travail permet de clarifier l'origine physique de cette loi. En comparant les resultats dynamiques aux resultats statiques, on se rend compte que la barriere extraite des calculs dynamiques est essentiellement la meme que celle obtenue par une approche statique, beaucoup plus simple. On peut donc obtenir cette barriere a l'aide de methodes plus precises, i.e., ab initio, comme la theorie de la fonctionnelle de la densite, qui sont aussi malheureusement beaucoup plus lourdes. C'est ce que nous avons fait pour plusieurs systemes metalliques. Nos resultats avec cette derniere approche se comparent tres bien aux resultats experimentaux. Nous nous sommes attardes plus longuement a la surface (111) du platine. Cette surface regorge de particularites interessantes, comme la forme d'equilibre non-hexagonale des i lots et deux sites d'adsorption differents pour l'adatome. De plus, des calculs ab initio precedents n'ont pas reussi a confirmer la

  7. Stratigraphy of Pyroclastic Deposits of EL Aguajito Caldera, Baja California Sur, MÉXICO

    NASA Astrophysics Data System (ADS)

    Osorio Ocampo, L. S.; Macias, J. L.; García Sánchez, L.; Pola, A.; Saucedo, R.; Sánchez, J. M.; Avellán, D. R.; Cardona, S.; Reyes-Agustín, G.; Arce, J. L.

    2015-12-01

    El Aguajito caldera is located in the State of Baja California Sur, it comprises an area of 450 km2 and sits within the Santa Rosalía Basin which is controlled by NE-SW extensional structures and the NW-SE Cimarron Fault that transects the caldera structure. The oldest rocks are ~90 Ma granodiorites covered by an Oligocene-Miocene volcano-sedimentary sequence, the Miocene Santa Lucia Formation and La Esperanza basalt. Pliocene volcanism is represented by La Reforma caldera, El Aguajito caldera, and the Tres Vírgenes Volcanic complex. This study focuses on the cartography and stratigraphy of area in order to understand the evolution of the volcanic system. The stratigraphy from base to top consists of a series of shallow marine sediments (fossiliferous sandstones) covered by a thick sequence of ignimbrites and pyroclastic flows interbedded with volcaniclastic deposits (Gloria and El Infierno Formations). On top of these deposits is El Aguajito caldera, it consists of a 2 m thick pumice fallout followed by an ignimbrite with three transitional lithofacies: a ≤30-m thick light-pink pyroclastic flow enriched in pumice at the base that gradually becomes enrich in lithics towards the top with the occurrence of degasing pipes. On top rests a 15 m-thick light-purple ignimbrite slightly welded with fiammes and a sequence of pumiceous pyroclastic flows and fallouts. These deposits have been associate to the caldera formation with a collapse diameter of ~8 km marked by rhyolitic domes exposed along a ring collapse crowned the sequence as well as NW-SE aligned rhyolitic domes parallel to the seashore. This cartography allowed to present a preliminary new geological map with four stratigraphic units recognized so far, that were emplaced under subaerial conditions beginning with a Plinian column followed by the emplacement of El Aguajito ignimbrite with its subsequent caldera collapse and finally the extrusion of resurgent domes.

  8. Availability of safe drinking-water: the answer to cholera outbreak? Nabua, Camarines Sur, Philippines, 2012

    PubMed Central

    de los Reyes, Vikki Carr; Sucaldito, Ma Nemia; Tayag, Enrique

    2015-01-01

    Background In May 2012, there were increasing diarrhoea cases and deaths reported from Nabua, Camarines Sur to the Philippines event-based surveillance system. An investigation was conducted to identify risk factors and determine transmission dynamics. Methods A suspected case was defined as a resident of Nabua with at least three episodes of watery diarrhoea per day from 16 March to 22 June 2012. A confirmed case was defined as a suspected case positive for Vibrio cholerae. An environmental investigation was conducted and rectal swabs and water samples sent to the national reference laboratory for bacterial isolation. A 1:2 case-control study matching for age and sex was conducted. Data were analysed using Epi Info. Results There were 309 suspected cases with two deaths, and the most affected age group was children under five years (45%). Eight cases were positive for Vibrio cholerae Ogawa El Tor and one for Non-01. Water samples were positive for faecal coliforms and Aeromonas caviae. The case-control study showed that cases had a higher odds than controls of using unchlorinated water sources (odds ratio [OR] = 3.6; 95% confidence interval [CI]:1.6–8.5) and having toilets located within 20 m of a septic tank (OR = 2.7; 95% CI: 1.4–5.3). In multivariate analysis, the only significant factor was drinking from piped water (OR = 0.21; 95% CI: 0.09–0.49). Discussion In this cholera outbreak, drinking-water from unchlorinated wells was a significant risk factor. Future cholera control efforts should include not just improving water and sanitation systems but also intensified behaviour change campaigns. PMID:26668761

  9. L'effet des deformations plastiques severes sur les proprietes d'hydruration du magnesium

    NASA Astrophysics Data System (ADS)

    Lang, Julien

    Le travail de recherche effectue durant mon projet de maitrise en physique a l'Universite du Quebec a Trois-Rivieres dans les laboratoires de l'Institut de Recherche sur l'Hydrogene etait de comparer l'effet du laminage a froid de la poudre de MgH2 avec celui du broyage mecanique. Nous avons etudie cette nouvelle technique en utilisant un laminoir vertical concu specialement pour laminer de la poudre. Nous avons lamine la poudre de MgH2 5, 25, 50 et 100 fois. La comparaison de la morphologie de la poudre de MgH 2 telle que recu du manufacturier et broye mecaniquement pendant 30 minutes avec celle de la poudre laminee ete faite a l'aide d'un microscope electronique a balayage. Nous avons par la suite mesure les proprietes de sorption d'hydrogene grace un appareil PCT de type Sievert. Nous avons aussi determine la structure cristalline par diffraction de rayons X. A partir de ces resultats, nous avons constate que le nombre optimal de laminages est de cinq et a les caracteristiques d'absorption/desorption d'hydrogene similaires a un broyage mecanique de 30 minutes. Nous avons aussi utilise les courbes de cinetiques d'absorption et de desorption d'hydrogene pour calculer l'etape limitative dans les reactions de sorption des echantillons lamines. Comme cinq laminages se font en environ 10 secondes, on voit que le laminage a froid est une technique plus interessante industriellement que le broyage mecanique a cause de l'important gain en temps et en energie.

  10. Regulation of myometrial contraction by ATP-sensitive potassium (KATP) channel via activation of SUR2B and Kir 6.2 in mouse.

    PubMed

    Hong, Seung Hwa; Kyeong, Kyu-Sang; Kim, Chan Hyung; Kim, Young Chul; Choi, Woong; Yoo, Ra Young; Kim, Hun Sik; Park, Yeon Jin; Ji, Il Woon; Jeong, Eun-Hwan; Kim, Hak Soon; Xu, Wen-Xie; Lee, Sang Jin

    2016-08-01

    ATP-sensitive potassium (KATP) channels are well characterized in cardiac, pancreatic and many other muscle cells. In the present study, functional expression of the KATP channel was examined in non-pregnant murine longitudinal myometrium. Isometric contraction measurements and Western blot were used. KATP channel openers (KCOs), such as pinacidil, cromakalim, diazoxide and nicorandil, inhibited spontaneous myometrial contractions in a reversible and glibenclamide-sensitive manner. KCOs inhibited oxytocin (OXT)- and prostaglandin F2α (PGF2α)-induced phasic contractions in a glibenclamide-sensitive manner. SUR2B and Kir6.2 were detected by Western blot, whereas SUR1, SUR2A and Kir6.1 were not. These results show that pinacidl, cromakalim, diazoxide and nicorandil-sensitive KATP channels exist in murine myometrium, which are composed of SUR2B and Kir6.2. Based on the modulatory effects of the KATP channel on spontaneous contraction, OXT- and PGF2α-induced contractions, KATP channels seem to play an essential role in murine myometrial motility via activation of SUR2B and Kir6.2.

  11. Regulation of myometrial contraction by ATP-sensitive potassium (KATP) channel via activation of SUR2B and Kir 6.2 in mouse

    PubMed Central

    HONG, Seung Hwa; KYEONG, Kyu-Sang; KIM, Chan Hyung; KIM, Young Chul; CHOI, Woong; YOO, Ra Young; KIM, Hun Sik; PARK, Yeon Jin; JI, Il Woon; JEONG, Eun-Hwan; KIM, Hak Soon; XU, Wen-Xie; LEE, Sang Jin

    2016-01-01

    ATP-sensitive potassium (KATP) channels are well characterized in cardiac, pancreatic and many other muscle cells. In the present study, functional expression of the KATP channel was examined in non-pregnant murine longitudinal myometrium. Isometric contraction measurements and Western blot were used. KATP channel openers (KCOs), such as pinacidil, cromakalim, diazoxide and nicorandil, inhibited spontaneous myometrial contractions in a reversible and glibenclamide-sensitive manner. KCOs inhibited oxytocin (OXT)- and prostaglandin F2α (PGF2α)-induced phasic contractions in a glibenclamide-sensitive manner. SUR2B and Kir6.2 were detected by Western blot, whereas SUR1, SUR2A and Kir6.1 were not. These results show that pinacidl, cromakalim, diazoxide and nicorandil-sensitive KATP channels exist in murine myometrium, which are composed of SUR2B and Kir6.2. Based on the modulatory effects of the KATP channel on spontaneous contraction, OXT- and PGF2α-induced contractions, KATP channels seem to play an essential role in murine myometrial motility via activation of SUR2B and Kir6.2. PMID:27086859

  12. Regulation of myometrial contraction by ATP-sensitive potassium (KATP) channel via activation of SUR2B and Kir 6.2 in mouse.

    PubMed

    Hong, Seung Hwa; Kyeong, Kyu-Sang; Kim, Chan Hyung; Kim, Young Chul; Choi, Woong; Yoo, Ra Young; Kim, Hun Sik; Park, Yeon Jin; Ji, Il Woon; Jeong, Eun-Hwan; Kim, Hak Soon; Xu, Wen-Xie; Lee, Sang Jin

    2016-08-01

    ATP-sensitive potassium (KATP) channels are well characterized in cardiac, pancreatic and many other muscle cells. In the present study, functional expression of the KATP channel was examined in non-pregnant murine longitudinal myometrium. Isometric contraction measurements and Western blot were used. KATP channel openers (KCOs), such as pinacidil, cromakalim, diazoxide and nicorandil, inhibited spontaneous myometrial contractions in a reversible and glibenclamide-sensitive manner. KCOs inhibited oxytocin (OXT)- and prostaglandin F2α (PGF2α)-induced phasic contractions in a glibenclamide-sensitive manner. SUR2B and Kir6.2 were detected by Western blot, whereas SUR1, SUR2A and Kir6.1 were not. These results show that pinacidl, cromakalim, diazoxide and nicorandil-sensitive KATP channels exist in murine myometrium, which are composed of SUR2B and Kir6.2. Based on the modulatory effects of the KATP channel on spontaneous contraction, OXT- and PGF2α-induced contractions, KATP channels seem to play an essential role in murine myometrial motility via activation of SUR2B and Kir6.2. PMID:27086859

  13. Impact de la varicocèle sur le volume testiculaire et les paramètres spermatiques

    PubMed Central

    Benazzouz, Mohamed Hicham; Essatara, Younes; El Sayegh, Hachem; Iken, Ali; Benslimane, Lounis; Nouini, Yassine

    2014-01-01

    Introduction La varicocèle est une pathologie masculine fréquente dont l'incidence est encore plus importante dans dans la population des hommes infertiles. Si ses mécanismes sont à ce jour incomplètement expliqués il semble acquis que la varicocèle peut être associée a une dysfonction testiculaire avec diminution du volume testiculaire et de la concentration en spermatozoïde de l’éjaculat. Méthodes Dans un premier temps nous exposons les résultats d'une étude rétrospective sur 5 ans (de Mars 2009 à Mars 2014), réalisée au service d'urologie A de l'hôpital Ibn Sina de Rabat et ayant comme objectif d’évaluer l'impact de la varicocèle palpable sur le volume testiculaire et les paramètres spermatiques. Tous les patients inclus dans notre étude avaient une varicocèle palpable. Dans un deuxième temps, et à travers une revue de la littérature nous discutons l'impact du traitement de la varicocèle sur la fertilité. Résultats 39 patients ont été inclus dans notre étude. L’âge moyen était de 29,71 ans et la varicocèle siégeait dans 89,74% des cas du coté gauche. Une atrophie testiculaire homolatérale à la varicocèle était retrouvée dans 7% des cas alors que des anomalies du spermogramme se voyaient dans 69,23% des cas. Conclusion L'impact de la varicocèle sur l'altération des paramètres spermatiques a été clairement établi bien que sa physio pathogénie ne soit pas bien élucidée. Le traitement chirurgical de la varicocèle semble indiqué chez les hommes infertiles présentant une varicocèle clinique et une altération significative du sperme. PMID:25918574

  14. Syndrome de Sweet: étude clinique et natomopathologique sur 5 ans

    PubMed Central

    Bouzidi, Hanae; Gallouj, Salim; Amraoui, Nissrine; Mernissi, Fatima Zahra; Harmouch, Taoufiq

    2015-01-01

    Le syndrome de Sweet ou dermatose aiguë fébrile neutrophilique est une maladie inflammatoire rare à expression cutanée prédominante, appartenant au groupe des dermatoses neutrophiliques. Il est caractérisé par le polymorphisme de son expression clinique et la diversité des maladies qui peuvent lui être associées. Le but de ce travail était d’étudier les particularités cliniques, anatomopathologiques, thérapeutiques et évolutives du syndrome de Sweet. Nous rapportons une étude rétrospective et descriptive de 25 cas de syndrome de Sweet observés dans les services de dermatologie et d'anatomie pathologique du centre hospitalier universitaire de Fès sur une période de 5 ans. Notre série était constituée de 5 hommes et de 20 femmes avec un sex-ratio (hommes/femmes) de 0,25. L’âge moyen des patients était de 47 ans avec des extrêmes allant de 11 à 75 ans. Des maladies associées étaient retrouvées chez 17 patients: hémopathies (deux cas), tumeur solide (1cas), maladie chronique de l'intestin (1cas), tuberculose (1 cas), diabète (trois cas) et infections (9 cas). Deux patientes étaient enceintes au moment du diagnostic. Les manifestations cutanées étaient polymorphes avec atteintes muqueuses dans deux cas. Les lésions siégeaient le plus souvent au niveau acral. Histologiquement, le derme était le siège d'un infiltrat dense et diffus riche en polynucléaires neutrophiles dans tous les cas. Une inflammation de la paroi des vaisseaux étaient observées dans trois cas. Le syndrome de Sweet peut être révélateur ou précéder des maladies associées, ce qui impose une surveillance rigoureuse et prolongée. PMID:26185554

  15. Mise à jour sur la vaccination contre l’herpès zoster

    PubMed Central

    Shapiro, Marla; Kvern, Brent; Watson, Peter; Guenther, Lyn; McElhaney, Janet; McGeer, Allison

    2011-01-01

    Résumé Objectif Répondre aux questions fréquentes concernant l’utilisation du nouveau vaccin contre l’herpès zoster (HZ). Sources de l’information Les résultats publiés d’études cliniques et d’autres études, les recommandations du Comité consultatif national de l’immunisation du Canada et de l’Advisory Committee on Immunization Practices des États-Unis; des données ont aussi été obtenues dans la monographie du produit approuvée par Santé Canada sur le vaccin. Principal message L’herpès zoster est causé par la réactivation du virus varicelle-zoster; l’algie post-zostérienne (APZ) est sa complication la plus fréquente et la plus grave. L’incidence de l’APZ après un zona est directement reliée à l’âge, notamment 50 % des personnes affectées de plus de 60 ans qui ont des douleurs persistantes non soulagées. Le vaccin à base de virus vivant contre le HZ réduit l’incidence du zona d’environ 50 % et de 2 tiers l’apparition des APZ. De plus, les symptômes sont atténués et de plus courte durée chez les personnes vaccinées. Le vaccin est contre-indiqué chez de nombreux patients immunodéprimés et pourrait ne pas être efficace chez les patients qui prennent des médicaments antiviraux qui agissent contre le virus HZ. Les médecins devraient être au courant des différentes recommandations touchant ces groupes. Conclusion Le vaccin contre le HZ est une mesure de prévention sécuritaire et efficace pour réduire le fardeau global et la gravité du zona chez les adultes plus âgés. Le vaccin semble rentable lorsqu’il est administré à des adultes de 60 ans et plus.

  16. Le cancer en Mauritanie : résultats sur 10 ans du registre hospitalier de Nouakchott

    PubMed Central

    Baba, Nacer Dine Ould Mohamed; Sauvaget, Catherine

    2013-01-01

    Le fardeau du cancer reste mal connu en Mauritanie. Il n'est basé que sur des extrapolations de l'incidence des cancers des pays avoisinants. Les données du registre de l'hôpital national permettent de décrire les cas avec un diagnostic histologique. Tous les cas de cancers enregistrés par le service d'anatomo-pathologie de l'hôpital national de Nouakchott de 2000 à 2009 ont été analysés. En 10 ans, 3305 prélèvements histologiques ont été analysés (hommes:42%, femmes:58%). Chez l'homme, le cancer le plus fréquemment analysé était le cancer de la peau (218 cas au total, 189 cas en excluant mélanome), suivi de la prostate (203), des cancers digestifs (179, colorectal et ‘sophage), et des lymphomes (151). Chez la femme, un quart des biopsies était des cancers du sein (485), suivi du col utérin (344), de la sphère gynécologique (218, ovaire et corps utérin), et de la peau (114). Les cancers du foie, du poumon ou de la vessie étaient peu fréquents. Ces résultats ne reflètent pas l'incidence ni l'actuel fardeau du cancer en Mauritanie puisque de nombreux patients diagnostiqués avec un cancer ne reçoivent pas d'examen anatomopathologique. Si, comme dans les pays avoisinants du Maroc et du Mali, les cancers du col et du sein sont les pathologies les plus fréquentes chez la femme, la distribution des cancers chez l'homme dans ce registre hospitalier diffère des résultats des registres de population du Maroc et du Mali où les cancers du poumon, du foie, de la prostate et de la vessie dominent. PMID:23785554

  17. Geochemistry of a Tertiary sedimentary phosphate deposit: Baja California Sur, Mexico

    USGS Publications Warehouse

    Piper, D.Z.

    1991-01-01

    The San Gregorio Formation in Baja California Sur, a phosphate-enriched sedimentary unit of late Oligocene to early Miocene age, has been analyzed in two areas (La Purisima and San Hilario) for its chemical composition (major oxides, Cu, Cd, Cr, Co, V, and rare-earth elements - REE) and isotopic composition (??18O and ??13C). A detrital and a marine component were determined from major oxides. The detrital component consists of an unaltered volcanic-ash fraction and a terrigenous clay-silt fraction. The marine component, which accumulated initially as biogenic and hydrogenous material, is now present as opal-A, opal-CT, CaCO3, organic matter, and an authigenic phosphate fraction, mostly pelletal and composed of the carbonate-fluorapatite mineral francolite. The minor elements have been partitioned into these components by assuming a constant composition for the two detrital fractions. The composition of the marine component of minor elements can then be interpreted by assuming that the stoichiometry of the original accumulating organic matter was equal to that of modern plankton. The Cu and Cd contents in the marine component of all rocks require that the seawater-derived fractions of these two metals were supplied to the seafloor solely by organic matter. Enrichments of Cr and V at both sites required an additional marine input. On the basis of their geochemistry in the modern ocean, Cr and V could have precipitated, or been adsorbed, onto settling particles from an O2 minimum zone in which the O2 content was low enough to promote denitrification rather than oxygen respiration. An enrichment of the REE, now within the apatite fraction, resulted from their adsorption onto particulates also in the O2 minimum zone and to the dissolution and alteration of biogenic phases (predominantly silica) within the sediment. Co and Fe2O3 show no enrichment above a detrital contribution. The ??18O-values of apatites from the La Purisima site are heavier than those of apatites

  18. The Palaeodiet of the Pericue Indians of the Cape Region of Baja California Sur, Mexico.

    NASA Astrophysics Data System (ADS)

    Beer, N.; Gonzalez, S.; Huddart, D.; Rosales-Lopez, A.; Lamb, A.

    2008-05-01

    The archaeology of the Pericue Indians inhabiting the Cape region of Baja California has long been an area of interest. The dolichocranic traits exhibited by this population have lead to suggestions that these people were a relic population of an early coastal migration into North America. The antiquity of directly dated Pericue human remains only reaches 3,000 B.P. with occupation sites dating back to 9,000 B.P. The site of Babisuri cave in Isla Espiritu Santo may demonstrate a very early human presence in Baja California Sur between 36,000 to 45,000 B.P. although the exact nature of this evidence is unclear. Increasing tourist development within this region threatens many archaeological sites particularly coastal shell middens and rock shelters. Current rescue excavations are yielding important information regarding many aspects of the culture of the Pericue Indians. Geochemical evidence of diet {d13C and d15N} taken from Pericue bone samples, modern and archaeological animals and modern plants is helping us to understand the complicated subsistence strategies of this group. Initial results highlight a complicated and diverse diet including marine and terrestrial resources, most likely exploited seasonally. Similarities between the diet of the Pericue and other nearby coastal Indian groups are clear and will be discussed. Pericue Indian material culture, combined with the exploitation of marine mammals and the construction of enormous shell mounds display parallels with other central and North American groups. The exploitation of marine mammals and the associated stone tools display striking similarities to the Chumash people of the Channel Islands of Coastal Southern California. Some of these cultural similarities will be highlighted in this presentation. Current genetic work is attempting to discover the nature of the similarities between the Chumash and Pericue groups as some cultural elements of each group have parallels with the other. Initial genetic

  19. Modelling impacts of offshore wind farms on trophic web: the Courseulles-sur-Mer case study

    NASA Astrophysics Data System (ADS)

    Raoux, Aurore; Pezy, Jean-Philippe; Dauvin, Jean-Claude; Tecchio, samuele; Degraer, Steven; Wilhelmsson, Dan; Niquil, Nathalie

    2016-04-01

    The French government is planning the construction of three offshore wind farms in Normandy. These offshore wind farms will integrate into an ecosystem already subject to a growing number of anthropogenic disturbances such as transportation, fishing, sediment deposit, and sediment extraction. The possible effects of this cumulative stressors on ecosystem functioning are still unknown, but they could impact their resilience, making them susceptible to changes from one stable state to another. Understanding the behaviour of these marine coastal complex systems is essential in order to anticipate potential state changes, and to implement conservation actions in a sustainable manner. Currently, there are no global and integrated studies on the effects of construction and exploitation of offshore wind farms. Moreover, approaches are generally focused on the conservation of some species or groups of species. Here, we develop a holistic and integrated view of ecosystem impacts through the use of trophic webs modelling tools. Trophic models describe the interaction between biological compartments at different trophic levels and are based on the quantification of flow of energy and matter in ecosystems. They allow the application of numerical methods for the characterization of emergent properties of the ecosystem, also called Ecological Network Analysis (ENA). These indices have been proposed as ecosystem health indicators as they have been demonstrated to be sensitive to different impacts on marine ecosystems. We present here in detail the strategy for analysing the potential environmental impacts of the construction of the Courseulles-sur-Mer offshore wind farm (Bay of Seine) such as the reef effect through the use of the Ecopath with Ecosim software. Similar Ecopath simulations will be made in the future on the Le Tréport offshore wind farm site. Results will contribute to a better knowledge of the impacts of the offshore wind farms on ecosystems. They also allow to

  20. Une arthrite septique sur prothèse totale de genou à Pasteurella multocida: à propos d'un cas

    PubMed Central

    Kouevidjin, Biova Teko; Bassinga, Jonathan Sylvanus

    2015-01-01

    Une arthrite septique sur PTG est due essentiellement au Staphylococcus aureus suivie des staphylocoques à coagulase négative, et les streptocoques. Au cours de ses 40 dernières années très peu de cas d'infection sur arthroplastie à Pasteurella multocida ont été rapporté. La présentation clinique n'a rien de spécifique.la contamination survient après une morsure, griffure ou léchage d'un chat. L'interrogatoire et l'examen bactériologique est la clé du diagnostique. Nous rapportons le cas d'une patiente de 84 ans qui présente une infection a Pasteurella multocida suite à une morsure du chat 06 jours au paravent. Elle a bénéficié d'une prise en charge chirurgicale par lavage et synovectomie et une bi-antibiothérapie avec bonne évolution. PMID:26523162

  1. From Bretonneau to therapeutic antibodies, from specificity to specific remedies, Saint-Cyr-Sur-Loire, France, November 19, 2012

    PubMed Central

    Marchand, Claire; Nouat, Romaric; Watier, Hervé

    2013-01-01

    Held on November 19, 2012 in Saint-Cyr-sur-Loire, France, the symposium “From Bretonneau to therapeutic antibodies, from specificity to specific remedies” focused on the historical development of antibodies as therapeutics, with an emphasis on the seminal work of the French physician Pierre-Fidèle Bretonneau (1778–1862). The morning session was devoted to discussion of the evolution of the concept of specificity in medicine, which started with an epistemological definition. The contributions of Bretonneau to the emergence of the concept of specificity, notably with his studies on diphtheria, and the subsequent development of antidiphtheric serotherapy in Europe during the period 1894–1898 were then presented in detail. The afternoon session began with a presentation on the role of French physiologists during the years 1860–1890 in establishing the basic concepts of specific immunity and the principles of serotherapy. The history of antivenom serotherapy, particularly its discovery by Césaire Phisalix, and the development of antilymphocyte globulins as successful transplantation drugs were then discussed. The symposium ended with the inauguration of a stele representing Bretonneau, who lived in Saint-Cyr-sur-Loire and died 150 y ago. PMID:23924799

  2. Methodologie de conception numerique d'un ventilateur helico-centrifuge basee sur l'emploi du calcul meridien

    NASA Astrophysics Data System (ADS)

    Lallier-Daniels, Dominic

    La conception de ventilateurs est souvent basée sur une méthodologie « essais/erreurs » d'amélioration de géométries existantes ainsi que sur l'expérience de design et les résultats expérimentaux cumulés par les entreprises. Cependant, cette méthodologie peut se révéler coûteuse en cas d'échec; même en cas de succès, des améliorations significatives en performance sont souvent difficiles, voire impossibles à obtenir. Le projet présent propose le développement et la validation d'une méthodologie de conception basée sur l'emploi du calcul méridien pour la conception préliminaire de turbomachines hélico-centrifuges (ou flux-mixte) et l'utilisation du calcul numérique d'écoulement fluides (CFD) pour la conception détaillée. La méthode de calcul méridien à la base du processus de conception proposé est d'abord présentée. Dans un premier temps, le cadre théorique est développé. Le calcul méridien demeurant fondamentalement un processus itératif, le processus de calcul est également présenté, incluant les méthodes numériques de calcul employée pour la résolution des équations fondamentales. Une validation du code méridien écrit dans le cadre du projet de maîtrise face à un algorithme de calcul méridien développé par l'auteur de la méthode ainsi qu'à des résultats de simulation numérique sur un code commercial est également réalisée. La méthodologie de conception de turbomachines développée dans le cadre de l'étude est ensuite présentée sous la forme d'une étude de cas pour un ventilateur hélico-centrifuge basé sur des spécifications fournies par le partenaire industriel Venmar. La méthodologie se divise en trois étapes: le calcul méridien est employé pour le pré-dimensionnement, suivi de simulations 2D de grilles d'aubes pour la conception détaillée des pales et finalement d'une analyse numérique 3D pour la validation et l'optimisation fine de la géométrie. Les résultats de calcul m

  3. Stratigraphy and geochronology of the Comondú Group near Loreto, Baja California sur, Mexico

    NASA Astrophysics Data System (ADS)

    Umhoefer, Paul J.; Dorsey, Rebecca J.; Willsey, Shawn; Mayer, Larry; Renne, Paul

    2001-10-01

    Upper Oligocene to Middle Miocene volcanic and sedimentary rocks in the Loreto region, Baja California Sur, are widely exposed and make up the Comondú Group as redefined here following McFall. The Comondú Group is part of a volcanic arc and forearc basin that formed along the northwestern margin of Mexico. Regional to detailed scale mapping, stratigraphic analysis, and geochronology in a 10-20-km-wide and 70-km-long belt from the gulf escarpment to the coast near Loreto reveal three main units in the Comondú Group and a composite thickness of ˜1.5-2 km. (1) The lower clastic unit (˜30-19 Ma) contains 200-300 m of fluvial sandstone and conglomerate with probable local eolian deposits and numerous felsic tuffs and basalt flows that accumulated in a forearc basin. (2) The middle breccia and lava flow unit (˜19-15 Ma) is up to 750 m thick and consists of massive andesite breccia that was deposited as proximal debris flows interbedded with minor andesite lava flows. (3) The upper lava flow and breccia unit (˜15-12 Ma) consists almost entirely of up to ˜600 meters of andesite lava flows a few kilometers west of Loreto that are part of a composite volcano. North and south of Loreto for up to 25 km, the unit is composed of andesite lava flows and massive andesite breccia that formed from thick debris flows near that and other volcanic centers. The three units of the Comondú Group in the Loreto area correlated with the Salto, Pelones, and Ricasón formations of the Bahı´a Concepción area. The lower clastic unit of this study is time equivalent to the marine San Gregorio, El Cien, and Isidro formations on the western and southern Baja California peninsula. The middle and upper units of the Loreto area are the proximal equivalent to the type section of the Comondú Group near the village of Comondú. During deposition of the lower part of the Comondú Group, the arc lay to the east on mainland Mexico in the Sierra Madre Occidental, and then migrated to the

  4. Mesure et retroaction sur un qubit multi-niveaux en electrodynamique quantique en circuit non lineair

    NASA Astrophysics Data System (ADS)

    Boissonneault, Maxime

    L'electrodynamique quantique en circuit est une architecture prometteuse pour le calcul quantique ainsi que pour etudier l'optique quantique. Dans cette architecture, on couple un ou plusieurs qubits supraconducteurs jouant le role d'atomes a un ou plusieurs resonateurs jouant le role de cavites optiques. Dans cette these, j'etudie l'interaction entre un seul qubit supraconducteur et un seul resonateur, en permettant cependant au qubit d'avoir plus de deux niveaux et au resonateur d'avoir une non-linearite Kerr. Je m'interesse particulierement a la lecture de l'etat du qubit et a son amelioration, a la retroaction du processus de mesure sur le qubit de meme qu'a l'etude des proprietes quantiques du resonateur a l'aide du qubit. J'utilise pour ce faire un modele analytique reduit que je developpe a partir de la description complete du systeme en utilisant principalement des transfprmations unitaires et une elimination adiabatique. J'utilise aussi une librairie de calcul numerique maison permettant de simuler efficacement l'evolution du systeme complet. Je compare les predictions du modele analytique reduit et les resultats de simulations numeriques a des resultats experimentaux obtenus par l'equipe de quantronique du CEASaclay. Ces resultats sont ceux d'une spectroscopie d'un qubit supraconducteur couple a un resonateur non lineaire excite. Dans un regime de faible puissance de spectroscopie le modele reduit predit correctement la position et la largeur de la raie. La position de la raie subit les decalages de Lamb et de Stark, et sa largeur est dominee par un dephasage induit par le processus de mesure. Je montre que, pour les parametres typiques de l'electrodynamique quantique en circuit, un accord quantitatif requiert un modele en reponse non lineaire du champ intra-resonateur, tel que celui developpe. Dans un regime de forte puissance de spectroscopie, des bandes laterales apparaissent et sont causees par les fluctuations quantiques du champ electromagnetique

  5. Late Quaternary Faulting along the San Juan de los Planes Fault Zone, Baja California Sur, Mexico

    NASA Astrophysics Data System (ADS)

    Busch, M. M.; Coyan, J. A.; Arrowsmith, J.; Maloney, S. J.; Gutierrez, G.; Umhoefer, P. J.

    2007-12-01

    As a result of continued distributed deformation in the Gulf Extensional Province along an oblique-divergent plate margin, active normal faulting is well manifest in southeastern Baja California. By characterizing normal-fault related deformation along the San Juan de los Planes fault zone (SJPFZ) southwest of La Paz, Baja California Sur we contribute to understanding the patterns and rates of faulting along the southwest gulf-margin fault system. The geometry, history, and rate of faulting provide constraints on the relative significance of gulf-margin deformation as compared to axial system deformation. The SJPFZ is a major north-trending structure in the southern Baja margin along which we focused our field efforts. These investigations included: a detailed strip map of the active fault zone, including delineation of active scarp traces and geomorphic surfaces on the hanging wall and footwall; fault scarp profiles; analysis of bedrock structures to better understand how the pattern and rate of strain varied during the development of this fault zone; and a gravity survey across the San Juan de los Planes basin to determine basin geometry and fault behavior. The map covers a N-S swath from the Gulf of California in the north to San Antonio in the south, an area ~45km long and ~1-4km wide. Bedrock along the SJPFZ varies from Cretaceous Las Cruces Granite in the north to Cretaceous Buena Mujer Tonalite in the south and is scarred by shear zones and brittle faults. The active scarp-forming fault juxtaposes bedrock in the footwall against Late Quaternary sandstone-conglomerate. This ~20m wide zone is highly fractured bedrock infused with carbonate. The northern ~12km of the SJPFZ, trending 200°, preserves discontinuous scarps 1-2km long and 1-3m high in Quaternary units. The scarps are separated by stretches of bedrock embayed by hundreds of meters-wide tongues of Quaternary sandstone-conglomerate, implying low Quaternary slip rate. Further south, ~2 km north of the

  6. Lipid Biomarkers for Methanogens in Hypersaline Cyanobacterial Mats for Guerrero Negro, Baja California Sur

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda L.; Embaye, Tsegereda; Summons, Roger E.; Fonda, Mark (Technical Monitor)

    2002-01-01

    Analyses of sediments from the vicinity of active methane seeps have uncovered a particular suite of lipid biomarker patterns that characterize methane consuming archaea and their syntrophic, sulfate reducing partners. These isoprenoid biomarkers, largely identified by their anomalously light carbon isotopic signatures, have been a topic of intense research activity and are recorded in numerous methane-rich environments from Holocene to Cenozoic. This phenomenon has implications for depleted kerogens at 2.7 Ga on early Earth (Hinrichs 2002). In contrast, the lipid biosignatures of methane producing archaea are not readily identified through distinct isotopic labels and have received comparably little attention in analyses of archaea in environmental samples. Indeed, environmental analyses generally detect only free archaeal lipids, not the intact, polar molecules found in the membrane of living organisms. As part of the Ames NAI, the 'Early Microbial Ecosystem Research Group' (EMERG) is working to understand microbial processes in the hypersaline cyanobacterial mats growing in the salt evaporation ponds of the Exportadora de Sal at Guerrero Negro, Baja California Sur, Mexico. The aim of this study was to develop methods by which we could identify the organisms responsible for methane generation in this environment. While the ester-bound fatty acids, hopanoids and wax esters provide a means to identify most of the bacterial components of these mats, the archaea which Ere evidently present through genomic assays and the fact of intense methane production (Hoehler et al. 200l), have not been identified through their corresponding lipid signatures. Archaeal core lipids present a number of analytical challenges. The core lipids of methanogens comprise C20, C40 and sometimes C25 isoprenoid chains, linked through ether bonds to glycerol. As well as archaeal (C20), sn-2- and sn-3-hydroxyarchaeol are associated particularly with methylotrophic methanogens. Recently, we have

  7. Actes des journees de linguistique: Colloque sur la recherche etudiante (Proceedings of the Linguistics Conference: Colloquium on Student Research) (Quebec, Canada, March 18-19, 1988).

    ERIC Educational Resources Information Center

    Lepage, Danielle, Ed.; Dominik, Annette, Ed.

    Presentations by students at a colloquium on student research on the occasion of the 50th anniversary of the University of Laval's Faculty of Letters, March 18-19, 1988, include: "Une enquete sur la qualite du francais ecrit au Quebec"; "Amenagement linguistique et neologie"; "Analyse syntaxique des 'arrets et retours' en arabe morocain parle";…

  8. Conséquences des nouvelles formes de commande sur les matériaux de l'isolation statorique

    NASA Astrophysics Data System (ADS)

    Bellomo, J. P.; Lebey, Th.; Peltier, Fr.; Oraison, J. M.

    1997-05-01

    Use of inverter drive for rotating machines speed control leads to the application of new stress on stator insulation materials. The integrity of these materials under such stresses has therefore to be studied. Thanks to specially equipped motor, the different voltage shapes have been identified. Very short rise time fronts, large overvoltages and high oscillation frequencies are obtained. These voltages are then reproduced on laboratory samples (Polyethylene Terephtalate). The main result is the existence of trapped surface charges related both to the rise front value and to the existence of polar mechanisms in the material bulk. The consequences of this surface charge existence on the reliability of a real system are then discussed. L'utilisation de nouvelles formes de commande pour les machines à courant alternatif se traduit par l'apparition d'un nouveau type de contraintes sur les matériaux de l'isolation statorique. L'étude de leur comportement sous l'action de ce type de contraintes revêt un intérêt tout particulier pour la validation et la stabilité de ces systèmes dans le temps. Nous présentons, tout d'abord, ces différentes formes de tension identifiées à l'aide d'un moteur spécialement instrumenté. L'existence de fronts de tension très élevés, de surtensions importantes (jusqu'à 500V) et d'oscillations hautes fréquences (2MHz), est mise en évidence. La reproduction de ces contraintes en laboratoire sur des échantillons de polyesters (PolyÉthylène Térephthalate) permet alors de déterminer l'influence des formes de tension carrées sur les propriétés intrinsèques du matériau. Elle se traduit par l'existence d'une charge piégée en surface du diélectrique. Cette charge superficielle est associée, d'une part à l'existence de phénomènes de relaxation dans les matériaux étudiés et d'autre part à la valeur des fronts de tension appliqués. Pour finir, les conséquences possibles de l'existence de ces charges superficielles

  9. Profil bactériologique du pied diabétique et son impact sur le choix des antibiotiques

    PubMed Central

    Zemmouri, Adil; Tarchouli, Mohamed; Benbouha, Abdellatif; Lamkinsi, Tarik; Bensghir, Mustapha; Elouennass, Mostafa; Haimeur, Cherqui

    2015-01-01

    Introduction Analyse du profil bactériologique des pieds diabétiques pris en charge à l'hôpital militaire de Rabat et son influence sur l'antibiothérapie de première intention. Méthodes Etude prospective non randomisée étalée sur 18 mois, ayant concerné 105 patients. Après recueil des données et en attente des résultats bactériologiques nos patients ont été divisés en deux groupes: un groupe a été mis sous Amoxicilline + Acide clavulanique + Gentamycine (59 patients) et un groupe sous Ertapénème±Gentamycine (46 patients). Résultats L’étude a regroupé 85 hommes et 20 femmes (sexe ratio = 4.26). L’âge moyen est de 64.4 ans. La gangrène a été observée chez 79% des malades; elle était humide-donc surinfectée en principe- dans 43% des cas. Par ailleurs, 67% des malades ont un chiffre de globules blancs 12000 définissant une infection sévère. L'ostéolyse a été mise en évidence chez 27% de nos patients. Parmi les différentes techniques de prélèvements: 81% ont été profonds dont 21% de biopsie osseuse per opératoire et 14% de prélèvements combinés. 42% de ces prélèvements sont poly microbiens et 21% sont stériles. Les résultats bactériologiques viennent confirmer la prédominance des bactéries aérobies à Gram positif. Le taux de remplacement de l'Ertapénème est de 22% contre un taux de 50% pour l'Amoxiclav. Conclusion L'antibiothérapie ne doit être instaurée qu'en cas d'infection du pied diabétique diagnostiquée sur les critères cliniques établis par les consensus internationaux récents. Le respect des mesures de lutte contre la diffusion de la résistance bactérienne s'avère primordiale. PMID:27386024

  10. Nicotinamide-rich diet protects the heart against ischaemia-reperfusion in mice: a crucial role for cardiac SUR2A.

    PubMed

    Sukhodub, Andriy; Du, Qingyou; Jovanović, Sofija; Jovanović, Aleksandar

    2010-06-01

    It is a consensus view that a strategy to increase heart resistance to ischaemia-reperfusion is a warranted. Here, based on our previous study, we have hypothesized that a nicotinamide-rich diet could increase myocardial resistance to ischaemia-reperfusion. Therefore, the purpose of this study was to determine whether nicotinamide-rich diet would increase heart resistance to ischaemia-reperfusion and what is the underlying mechanism. Experiments have been done on mice on control and nicotinamide-rich diet (mice were a week on nicotinamide-rich diet) as well as on transgenic mice overexpressing SUR2A (SUR2A mice), a regulatory subunit of cardioprotective ATP-sensitive K(+) (K(ATP)) channels and their littermate controls (WT). The levels of mRNA in heart tissue were measured by real-time RT-PCR, whole heart and single cell resistance to ischaemia-reperfusion and severe hypoxia was measured by TTC staining and laser confocal microscopy, respectively. Nicotinamide-rich diet significantly decreased the size of myocardial infarction induced by ischaemia-reperfusion (from 42.5+/-4.6% of the area at risk zone in mice on control diet to 26.8+/-1.8% in mice on nicotinamide-rich diet, n=6-12, P=0.031). The cardioprotective effect of nicotinamide-rich diet was associated with 11.46+/-1.22 times (n=6) increased mRNA levels of SUR2A in the heart. HMR1098, a selective inhibitor of the sarcolemmal K(ATP) channels opening, abolished cardioprotection afforded by nicotinamide-rich diet. Transgenic mice with a sole increase in SUR2A expression had also increased cardiac resistance to ischaemia-reperfusion. We conclude that nicotinamide-rich diet up-regulate SUR2A and increases heart resistance to ischaemia-reperfusion.

  11. Rupture utérine sur utérus bicorne à 12 semaines d'aménorrhée: à propos d'un cas

    PubMed Central

    Itchimouh, Sanaa; Khabtou, Karima; Mahdaoui, Sakher; Boufettal, Houssine; Samouh, Naima

    2016-01-01

    La fréquence des malformations utérines ayant un impact sur la reproduction est difficile à apprécier. Leur mise en évidence nécessite un bilan spécifique (hystérosalpingographie, hystéroscopie, cœlioscopie). La fertilité spontanée peut être altérée en fonction du type d'anomalie utérine. Toutes ces anomalies peuvent avoir des répercussions sur l’évolution de la conception à type de fausses couches précoces et tardives, de grossesse extra utérine, de menace d'accouchement prématuré, d'accouchement prématuré, de pathologies vasculaires gravidiques et de retard de croissance intra-utérin. L'utérus bicorne est la plus connue des malformations et représente environ la moitié des anomalies de l'utérus. La survenue d'une telle grossesse constitue une situation à risque pouvant entraîner une mort maternelle, mais le diagnostic précoce et un bon suivi peut mener des grossesses à terme sur des utérus malformé. Le dépistage échographique devrait permettre la détection systématique de ce genre de cas afin de prendre préventivement les mesures qui s'imposent. Nous rapportons un cas de rupture utérine sur utérus bicorne unicervical sur grossesse à 12 semaines d'aménorrhée. PMID:27642490

  12. Testosterone protects female embryonic heart H9c2 cells against severe metabolic stress by activating estrogen receptors and up-regulating IES SUR2B.

    PubMed

    Ballantyne, Thomas; Du, Qingyou; Jovanović, Sofija; Neemo, Andrew; Holmes, Robert; Sinha, Sharabh; Jovanović, Aleksandar

    2013-02-01

    A recent clinical study demonstrated that a testosterone supplementation improves functional capacity in elderly female patients suffering from heart failure. These findings prompted us to consider possible mechanisms of testosterone-induced cardioprotection in females. To address this question we have used a pure female population of rat heart embryonic H9c2 cells. Pre-treatment of cells with testosterone for 24h significantly increased survival of H9c2 cells exposed to 2,4-dinitrophenol (DNP), an inhibitor of oxidative phosphorylation. These cells expressed low level of androgen receptors and the effect of testosterone was not modified by hydroxyflutamide, an antagonist of androgen receptor. In contrast, cyclohexamide, an inhibitor of protein biosynthesis, and tamoxifene, a partial agonist of estrogen receptors, abolished cardioprotection afforded by testosterone. In addition, finasteride, an inhibitor of 5α-reductase, and anastrazole, an inhibitor of α-aromatase, also blocked testosterone-induced cytoprotection. Real time RT-PCR revealed that testosterone did not regulate the expression of nine subunits and accessory proteins of sarcolemmal ATP-sensitive K(+) (K(ATP)) channels. On the other hand, testosterone, as well as 17β-estradiol, up-regulated a putative mitochondrial K(ATP) channel subunit, mitochondrial sulfonylurea receptor 2B intraexonics splice variant (IES SUR2B), without affecting expression of IES SUR2A. Tamoxifene inhibited testosterone-induced up-regulation of IES SUR2B without affecting IES SUR2A. In conclusion, this study has shown that testosterone protect female embryonic heart H9c2 cells against severe metabolic stress by its conversion into metabolites that activate estrogen receptors and up-regulate IES SUR2B.

  13. Le défi de la recherche sur les médicaments et du traitement des enfants au Canada

    PubMed Central

    Rieder, Michael J

    2011-01-01

    RÉSUMÉ Les enfants ont toujours été des « orphelins thérapeutiques ». De nombreux médicaments n’ont pas fait l’objet d’études auprès des enfants et des adolescents ou leur utilisation n’est pas autorisée officiellement auprès d’eux, ce qui crée un défi constant en matière d’élaboration et de définition de pharmacothérapies à la sécurité et l’efficacité optimales au sein du groupe d’âge pédiatrique. Depuis dix ans, des réseaux ont germé aux États-Unis et en Europe afin d’accroître la recherche sur les médicaments dans ce groupe, mais aucune évolution comparable ne s’observe au Canada. Le présent document de principes expose le contexte de la situation canadienne et contient des recommandations qui tiennent compte de deux besoins pressants : plus de recherches sur les médicaments axées sur les enfants et les adolescents canadiens, y compris un financement dédié à de telles recherches, et plus d’effectifs pour mener des études ciblées. Ces initiatives devraient être entreprises en collaboration, sur les scènes nationale et internationale, et inclure des démarches stratégiques et novatrices afin de régler les problèmes et enjeux éthiques uniques que présente la recherche sur les médicaments au sein de cette population.

  14. Cancer développé sur dilatation kystique de la voie biliaire: à propos d’un cas

    PubMed Central

    Soufi, Mehdi; Lahlou, Mohammed Khalid; Chad, Bouziane

    2014-01-01

    Les auteurs rapportent un cas de dilatation kystique du cholédoque intra- pancréatique découvert chez une femme de 46 ans et compliqué d'un carcinome tubulo-papillaire n'envahissant pas le pancréas. Le traitement a consisté en une duodénopancréatectomie céphalique avec un curage ganglionnaire et anastomose hépatico-jéjunale; la survie était de 30 mois; les auteurs abordent les aspects radiologiques, anatomopathologiques, thérapeutiques et pronostiques de ces cancers développé sur dilatation kystique de la voie biliaire et discutent la place d'une radiothérapie complémentaire de la chirurgie susceptible d'améliorer la survie. PMID:25922635

  15. Influence du chrome et du niobium sur l'équilibre α-γ dans les aluminiures de titane

    NASA Astrophysics Data System (ADS)

    Daloz, D.; Hazotte, A.; Lacaze, J.; Charpentier, M.

    2004-12-01

    L’influence du chrome et du niobium sur les transformations et équilibres de phases des aluminiures de titane dans le domaine biphasé a/g est étudiée par analyse thermique différentielle, dilatomètrie, et métallographie quantitative après traitements thermiques suivis de trempe. Les compositions et les taux de phases à l’équilibre sont déterminés pour différentes températures du domaine biphasé a/g. Les résultats sont comparés aux calculs thermodynamiques réalisés à l’aide d’une banque de données relative aux intermétalliques de base Ti-Al.

  16. Reconnaissance geologic map of the Loreto and part of the San Janier quadrangles, Baja California Sur, Mexico

    USGS Publications Warehouse

    McLean, Hugh

    1988-01-01

    The Loreto area of Baja California Sur, Mexico, contains a diverse association of igneous, sedimentary, and metasedimentary rocks exposed in the foothills and arroyos between the Sierra La Giganta and Gulf of California. The Loreto area was selected for this study to examine the possible relation of the marine rocks to the opening of the Gulf of California, and to determine the stratigraphic and structural relations between basement rocks composed of granitic and prebatholithic rocks and overlying Tertiary (mainly Miocene) sedimentary and volcanic rocks, and by a sequence of Pliocene marine and nonmarine sedimentary rocks. The Pliocene marine rocks lie in a structural depression informally called here, the Loreto embayment. This geologic map and report stem from a cooperative agreement between the U.S. Geological Survey and the Consejo de Recursos Minerales of Mexico that was initiated in 1982.

  17. Ondes de surface transverses sur plaques piézoélectriques avec réseaux de bandes metalliques déposés sur les 2 faces

    NASA Astrophysics Data System (ADS)

    Ballandras, S.; Gavignet, E.; Bigler, E.

    1995-09-01

    A theoretical model has been implemented to study surface transverse waves propagating on piezoelectric plates of finite thickness with thin metal strip gratings on both sides. Calculations have been performed for AT-cuts of quartz of thickness varying from 140 to 120 μm. The spatial period of the gratings was fixed to 20 μm (acoustic wavelength equal to 40 μm). The dispersion curve relating the angular frequency to the wavenumber presents more than one stopband as found in the usual analyses on semi-infinite substrates. These multiple high-frequency stopbands allow to design and realize high stability resonators or highly sensitive sensors for gravimetry, accelerometer applications, etc. Un modèle théorique a été mis en œuvre pour l'étude des propriétés des ondes de surface transverses se propageant sur des plaques piézoélectriques d'épaisseur finie avec des réseaux de fines bandes métalliques déposés sur chaque face. Les calculs ont été effectués pour des plaques de quartz voisines de la coupe AT et d'épaisseur variant de 140 à 120 μm. La périodicité des réseaux en regard a été fixée à 20 μm (longueur d'onde acoustique 40 μm). La courbe de dispersion reliant la pulsation au nombre d'ondes présente plusieurs bandes d'arrêt incluant celle habituellement mise en évidence pour un substrat semi-infini. L'existence de ces multiples bandes d'arrêt haute fréquence ouvre de nouvelles perspectives pour la réalisation de résonateurs ultrastables ou de capteurs de très grande sensibilité gravimétrique, accélérométrique, etc.

  18. Volvulus gastrique aigu sur éventration diaphragmatique de l'adulte: à propos d'un cas et revue de la littérature

    PubMed Central

    Guèye, Mohamadou Lamine; Touré, Alpha Oumar; Thiam, Ousmane; Seck, Mamadou; Cissé, Mamadou; Kâ, Ousmane; Dieng, Madieng; Touré, Cheikh Tidiane

    2015-01-01

    Le volvulus gastrique aigu sur éventration diaphragmatique est une affection rare et une urgence diagnostique et thérapeutique. Sa présentation clinique est peu spécifique et la tomodensitométrie abdominale permet de confirmer le diagnostic. Nous rapportons le cas d'un patient de 22 ans qui présentaitun syndrome occlusif et une voussure épigastrique. A la radiographie de l'Abdomen Sans Préparation, on notait 2 niveaux hydro-aériques sous la coupole diaphragmatique gauche qui était surélevée. Une dévolvulation et une gastrectomie atypique ont été réalisées devant un volvulus gastrique aigu avec nécrose du fundus mis en évidence à la laparotomie. Les suites opératoires ont été simples. PMID:26161223

  19. Restauration fonctionnelle du rachis : effet du niveau initial de douleur sur les performances des sujets lombalgiques chroniques

    PubMed Central

    Caby, Isabelle; Olivier, N; Mendelek, F; Kheir, R Bou; Vanvelcenaher, J; Pelayo, P

    2014-01-01

    HISTORIQUE : La lombalgie chronique est une douleur lombaire persistante d’origine multifactorielle. Le niveau de douleur initial reste faiblement utilisé pour analyser et comparer les réponses des patients lombalgiques au programme de reconditionnement. OBJECTIFS : Apprécier et évaluer les réponses des sujets lombalgiques chroniques très douloureux à une prise en charge dynamique et intensive. MÉTHODOLOGIE : 144 sujets atteints de lombalgie chronique ont été inclus dans un programme de restauration fonctionnelle du rachis de 5 semaines. Les sujets ont été classés en deux groupes de niveau de douleur: un groupe atteint de douleur sévère (n = 28) et un groupe atteint de douleur légère à modérée (n = 106). L’ensemble des sujets ont bénéficié d’une prise en charge identique comprenant principalement de la kinésithérapie, de l’ergothérapie, du reconditionnement musculaire et cardio-vasculaire ainsi qu’un suivi psychologique. Les paramètres physiques (flexibilité, force musculaire) et psychologiques (qualité de vie) ont été mesurés avant (T0) et après le programme (T5sem). RÉSULTATS : L’ensemble des performances physiques et fonctionnelles des sujets très douloureux sont moins bonnes et le retentissement de la lombalgie sur la qualité de vie, pour ces mêmes sujets, est majoré à T0. Toutes les différences significatives constatées à T0 entre les deux groupes s’effacent à T5sem. CONCLUSIONS : Les sujets lombalgiques chroniques très douloureux répondent favorablement au programme dynamique et intensif. L’intensité douloureuse de la lombalgie n’aurait pas d’effet sur les réponses au programme. La restauration fonctionnelle du rachis apporterait aux sujets la possibilité de mieux gérer leur douleur quel que soit son niveau. PMID:25299476

  20. Effet de l'interaction coulombienne sur la localisation d'Anderson dans le gaz bidimensionnel d'électrons

    NASA Astrophysics Data System (ADS)

    Fleury, G.

    2010-09-01

    Nous étudions l’effet des interactions coulombiennes sur la localisation d’Anderson dans le gaz bidimensionnel d’électrons désordonné. L’objectif est de statuer sur la question de l’existence de métaux à deux dimensions. En l’absence d’interaction, la théorie d’échelle de la localisation prédit qu’un désordre infinitésimal suffit à localiser la fonction d’onde électronique et donc à rendre le système isolant à température nulle (Abrahams et al., 1979). Dans certaines limites extrêmes, les interactions peuvent être prises en compte et l’on aboutit également à un état isolant. Cependant, aucune théorie analytique ne permet de traiter le régime quantique non-perturbatif où désordre et interaction sont intermédiaires. Expérimentalement, il est possible de l’explorer dans des échantillons de haute mobilité et basse densité. Depuis 1994, des comportements métalliques inexpliqués y ont été observés (Kravchenko et al., 1994). Nous avons mis au point une méthode numérique permettant d’étudier le problème couplé de la localisation d’Anderson en présence d’interaction. Cette méthode mêle Monte Carlo quantique à température nulle et théorie d’échelle pour la conductance de Thouless. Nous trouvons que la théorie d’échelle de la localisation est préservée en présence d’interaction et donc que le gaz bidimensionnel, même corrélé, est isolant à température nulle. Nos résultats montrent de plus que les interactions délocalisent le gaz bidimensionnel et que cet effet de délocalisation est accru en présence de dégénérescence de vallées. Ils nous permettent de proposer un mécanisme simple rendant compte des principales caractéristiques des comportements métalliques observés expérimentalement.

  1. Ability of a rapid HIV testing site to attract and test vulnerable populations: a cross-sectional study on Actuel sur Rue.

    PubMed

    Engler, Kim; Rollet, Kathleen; Lessard, David; Thomas, Réjean; Lebouché, Bertrand

    2016-10-01

    Quebec's HIV epidemic persists, particularly among men who have sex with men (MSM) and in Montreal. Increasing access to HIV testing is necessary and community-based rapid testing offers one strategy. This paper examines the clienteles and activities of a rapid HIV testing site in Montreal, the pilot project Actuel sur Rue. Comparative analyses were conducted with 1357 MSM, 147 heterosexual men and 64 women who visited Actuel sur Rue between July 2012 and November 2013 on socio-demographics, health, drug use, sexual practices/infection and HIV testing/prevention. Significant group differences were observed in each category. Actuel sur Rue received 1901 clients, conducted 1417 rapid HIV tests and tested 77 never-tested individuals. Rapid testing produced a high reactive rate (2%). Only 1/28 of those with reactive tests had no previous HIV testing, and 36% had used post-exposure prophylaxis, suggesting missed opportunities for prevention. Findings highlight diverse client vulnerability profiles and the relevance of checkpoints and further prevention efforts.

  2. Trichinella spiralis infection in pigs in the Bolivian Altiplano.

    PubMed

    Bjorland, J; Brown, D; Gamble, H R; McAuley, J B

    1993-05-01

    Trichinella spiralis infection has been reported sporadically in several areas in Central and South America. However, several countries, including Bolivia, have not reported trichinellosis in animals or humans. A small survey of pigs slaughtered in an abattoir in Bolivia was undertaken during September 1991, to determine the presence of Trichinella spiralis. In a group of 100 pigs slaughtered consecutively on a single day and tested using the pooled digestion method, two of eight pools (25%) were positive. Twenty-one of 188 pigs (11.2%) from ten communities slaughtered consecutively on a second day tested positive for the presence of antibodies to Trichinella spiralis using an enzyme-linked immunosorbent assay. It was concluded that trichinellosis is present in pigs in Bolivia and the rate of infection may be quite high.

  3. Electrical Resistivity Tomographies on the detection of adobe buried archaeological structures in Piramide Sur in Cahuachi (Peru)

    NASA Astrophysics Data System (ADS)

    Capozzoli, L.; Masini, N.; Rizzo, E.; Lasaponara, R.; Orefici, G.

    2012-04-01

    During the last two decades of excavations, adobe pyramids dating back from the 6th century B.C. to the 4th century A.D have been unearthed in the ancient Ceremonial Centre of Cahuachi near Nasca (Peru) by an Italian-Peruvian mission directed by Giuseppe Orefici. One of the archaeological sectors, called sector A, has been almost excavated and restored. To complete sector A only a terraced mound named "Piramide Sur" needs to be excavated. In order to provide useful information on the presence of buried structures and platforms as well on the geological stratigraphy a multi-scale approach based on the integration of satellite remote sensing with geophysical techniques was employed. Such investigations were carried out by the Italian mission ITACA, funded by the Italian Ministry Affairs and composed of researchers of two institutes of CNR (IMAA and IBAM), which provides a scientific support for archaeological research, since 2007. In particular, the subsurface features were investigated by Geoelectrical prospecting, performed by using a georesistivimeter for tomography which observe the resistivity value along sections. Several tomographies were carried out to investigate the shallow and deep structure of the pyramid both along the main flank at Nord and on the top. Finally, the integration of all data acquired by the different remote sensing techniques allowed for spatially characterizing the archaeological features, thus providing important information for the planning of the next archaeological campaign.

  4. Chaetognatha in the Bahía Magdalena lagoon complex, Baja California Sur, México: species composition and assemblages.

    PubMed

    Cota Meza, M S

    2011-07-01

    The chaetognaths from 187 zooplankton samples collected from the Bahia Magdalena lagoon complex, Baja California Sur, Mexico during March, June, July, August, September, November, and December 1982 were studied. Twelve species belonging to two genera were identified. Sagitta euneritica and S. enflata were the most abundant and most frequent species with maximum abundance in July (40,000 org/100 m(3) and 6100 org/100 m(3) respectively). Sagitta pacifica, S. regularis and S. pseudoserratodentata were stenothermic (21 to 25 degrees C), whereas the rest of the species were eurythermic (15.5 to 29.5 degrees C). Sagitta euneritica contributed considerably to the zooplanktonic biomass, increasing the density in particular in BahíaAlmejas. The analysis of the species assemblages (Morisita index) showed that S. pacifica and S. regularis interact more frequently in August when there is a change of the water masses that converge in this zone during summer, when the California Countercurrent predominates. The composition of taxa during winter is characterized by the dominance of S. euneritica. Entering the warm period, an abrupt change occurs in taxa composition of the three zones studied: channels, Bahía Magdalena, and BahíaAlmejas. The amplitude and distribution of S. peruviana was influenced possibility by the oceanographic conditions of ENSO 1982. PMID:22315819

  5. Baseline heavy metals and metalloid values in blood of loggerhead turtles (Caretta caretta) from Baja California Sur, Mexico.

    PubMed

    Ley-Quiñónez, C; Zavala-Norzagaray, A A; Espinosa-Carreón, T L; Peckham, H; Marquez-Herrera, C; Campos-Villegas, L; Aguirre, A A

    2011-09-01

    Environmental pollution due to heavy metals is having an increased impact on marine wildlife accentuated by anthropogenic changes in the planet including overfishing, agricultural runoff and marine emerging infectious diseases. Sea turtles are considered sentinels of ecological health in marine ecosystems. The objective of this study was to determine baseline concentrations of zinc, cadmium, copper, nickel, selenium, manganese, mercury and lead in blood of 22 clinically healthy, loggerhead turtles (Caretta caretta), captured for several reasons in Puerto López Mateos, Baja California Sur, Mexico. Zinc was the most prevalent metal in blood (41.89 μg g⁻¹), followed by Selenium (10.92 μg g⁻¹). The mean concentration of toxic metal Cadmium was 6.12 μg g⁻¹ and 1.01μg g⁻¹ respectively. Mean concentrations of metals followed this pattern: Zn>Se>Ni>Cu>Mn>Cd>Pb and Hg. We can conclude that blood is an excellent tissue to measure in relatively non-invasive way baseline values of heavy metals in Caretta caretta. PMID:21788056

  6. SUR1 Receptor Interaction with Hesperidin and Linarin Predicts Possible Mechanisms of Action of Valeriana officinalis in Parkinson

    PubMed Central

    Santos, Gesivaldo; Giraldez-Alvarez, Lisandro Diego; Ávila-Rodriguez, Marco; Capani, Francisco; Galembeck, Eduardo; Neto, Aristóteles Gôes; Barreto, George E.; Andrade, Bruno

    2016-01-01

    Parkinson’s disease (PD) is one of the most common neurodegenerative disorders. A theoretical approach of our previous experiments reporting the cytoprotective effects of the Valeriana officinalis compounds extract for PD is suggested. In addiction to considering the PD as a result of mitochondrial metabolic imbalance and oxidative stress, such as in our previous in vitro model of rotenone, in the present manuscript we added a genomic approach to evaluate the possible underlying mechanisms of the effect of the plant extract. Microarray of substantia nigra (SN) genome obtained from Allen Brain Institute was analyzed using gene set enrichment analysis to build a network of hub genes implicated in PD. Proteins transcribed from hub genes and their ligands selected by search ensemble approach algorithm were subjected to molecular docking studies, as well as 20 ns Molecular Dynamics (MD) using a Molecular Mechanic Poison/Boltzman Surface Area (MMPBSA) protocol. Our results bring a new approach to Valeriana officinalis extract, and suggest that hesperidin, and probably linarin are able to relieve effects of oxidative stress during ATP depletion due to its ability to binding SUR1. In addition, the key role of valerenic acid and apigenin is possibly related to prevent cortical hyperexcitation by inducing neuronal cells from SN to release GABA on brain stem. Thus, under hyperexcitability, oxidative stress, asphyxia and/or ATP depletion, Valeriana officinalis may trigger different mechanisms to provide neuronal cell protection. PMID:27199743

  7. MIS3 to late Holocene Palaeo-ice Thickness Constraints of Glacier Viedma, Hielo Patagonico Sur, Southern South America

    NASA Astrophysics Data System (ADS)

    Geiger, A.; Fabel, D.; Glasser, N. F.

    2014-12-01

    Southern South America is the only landmass intersecting the southern westerly winds (SWW), which critically shape southern hemispheric and global climate. At present palaeo-climatic datasets stretching the 3000 km of SWW influence are in latitudinal disagreement, suggesting a complex picture of SWW palaeo-behavior. In order to unravel the nature of the SWW over the last glacial cycle, a tighter grid of sensitive palaeo-proxies in the region is required. The work presented here is based on the palaeo-glaciology of the Viedma outlet (49°S, 72°W), the second largest glacier draining the Hielo Patagonico Sur (HPS). This locality corresponds to the present day center of the precipitation bearing SWW in southern South America, which are a key factor in maintaining the HPS. Any variation in SWW strength or location has a direct impact on glacial expansion in the region, hence palaeo-glacial geometries can provide key insights into SWW dynamics. Palaeo-ice surface, thickness and thinning rates spanning MIS3 to the late Holocene are presented based on 16 Be-10 exposure ages along three vertical transects covering the accumulation and ablation areas of glacier Viedma. Results indicate a maximum ice thickness over MIS3, a thickening over the Antarctic Cold Reversal (ACR), which overprinted the vertical expression of the LGM, and progressive ice surface lowering from the middle to the late Holocene. The palaeo-climatic implications will be discussed, particularly with focus on SWW positioning and behavior.

  8. Biological influences on modern sulfates: Textures and composition of gypsum deposits from Guerrero Negro, Baja California Sur, Mexico

    NASA Astrophysics Data System (ADS)

    Vogel, Marilyn B.; Des Marais, David J.; Parenteau, Mary N.; Jahnke, Linda L.; Turk, Kendra A.; Kubo, Michael D. Y.

    2010-01-01

    Gypsum (CaSO 4·2H 2O) deposits from a range of sedimentary environments at Guerrero Negro, Baja California Sur, Mexico were investigated for microscale texture and composition in order to differentiate features formed under substantial microbial influence from those for which microbial effects were relatively minor or absent. Gypsum deposits were classified according to their sedimentary environment, textures, crystal habit, brine composition and other geochemical factors. The environments studied included subaqueous sediments in anchialine pools and in solar salterns, as well as subsurface sediments of mudflats and saltpans. Gypsum that developed in the apparent absence of biofilms included crystals precipitated in the water column and subsedimentary discs that precipitated from phreatic brines. Subsedimentary gypsum developed in sabkha environments exhibited a sinuous microtexture and poikilitically enclosed detrital particles. Water column precipitates had euhedral prismatic habits and extensive penetrative twinning. Gypsum deposits influenced by biofilms included bottom nucleated crusts and gypsolites developing in anchialine pools and saltern ponds. Gypsum precipitating within benthic biofilms, and in biofilms within subaerial sediment surfaces provided compelling evidence of biological influences on crystal textures and habits. This evidence included irregular, high relief surface textures, accessory minerals (S°, Ca-carbonate, Sr/Ca-sulfate and Mg-hydroxide) and distinctive crystal habits such as equant forms and crystals having distorted prism faces.

  9. Syndrome de larva migrans cutanée sur pied malformé (à propos d'un cas)

    PubMed Central

    Benbella, Imane; Khalki, Hanane; Lahmadi, Khalid; Kouara, Sara; Abbadi, Abderrahim; Er-rami, Mohammed

    2016-01-01

    Le syndrome de larva migrans cutanée est une dermite sous cutanée causée par des larves d'ankylostomes d'animaux en impasse parasitaire chez l'homme. L'infestation transcutanée est favorisée par le contact avec le sol contaminé par les larves du parasite. Nous rapportons le cas d'un nourrisson de 15 mois, originaire de Guinée-Bissau, atteint d'un syndrome de larva migrans cutanée sur un pied malformé. Cette malformation sous forme d'une syndactylie associée à une tuméfaction du pied, était à l'origine d'un retard d'acquisition de la station debout. De même, on a rapporté une notion de pieds nus, vue la difficulté de chausser le pied malformé du patient. Tous ces facteurs auraient contribués à favoriser l'infestation du malade par les larves du nématode. PMID:27217876

  10. Rupture utérine spontanée sur léiomyosarcome utérin

    PubMed Central

    Boussouni, Khouloud; Benoulaid, Meryem; Dafiri, Rachida

    2016-01-01

    Les sarcomes utérins sont des cancers rares caractérisés par leur polymorphisme clinique et histologique. Ce sont des tumeurs malignes de mauvais pronostic. Ils se révèlent, généralement, par des symptômes non spécifiques à type de douleurs pelviennes, métrorragies. Un tableau d'abdomen aigu avec hémopneumopéritoine est une présentation rare. Nous rapportons le cas d'un léiomyosarcome utérin qui s'est manifesté par une péritonite aigue généralisée inaugurale chez une femme de 43 ans. Le diagnostic de perforation utérine sur tumeur maligne a été suspecté par l'imagerie préopératoire en urgence (échographie et TDM) et confirmé histologiquement. PMID:27642425

  11. Baseline heavy metals and metalloid values in blood of loggerhead turtles (Caretta caretta) from Baja California Sur, Mexico.

    PubMed

    Ley-Quiñónez, C; Zavala-Norzagaray, A A; Espinosa-Carreón, T L; Peckham, H; Marquez-Herrera, C; Campos-Villegas, L; Aguirre, A A

    2011-09-01

    Environmental pollution due to heavy metals is having an increased impact on marine wildlife accentuated by anthropogenic changes in the planet including overfishing, agricultural runoff and marine emerging infectious diseases. Sea turtles are considered sentinels of ecological health in marine ecosystems. The objective of this study was to determine baseline concentrations of zinc, cadmium, copper, nickel, selenium, manganese, mercury and lead in blood of 22 clinically healthy, loggerhead turtles (Caretta caretta), captured for several reasons in Puerto López Mateos, Baja California Sur, Mexico. Zinc was the most prevalent metal in blood (41.89 μg g⁻¹), followed by Selenium (10.92 μg g⁻¹). The mean concentration of toxic metal Cadmium was 6.12 μg g⁻¹ and 1.01μg g⁻¹ respectively. Mean concentrations of metals followed this pattern: Zn>Se>Ni>Cu>Mn>Cd>Pb and Hg. We can conclude that blood is an excellent tissue to measure in relatively non-invasive way baseline values of heavy metals in Caretta caretta.

  12. Evolution de films de cuivre sur un substrat de cordiérite au cours de traitements thermiques

    NASA Astrophysics Data System (ADS)

    Guille, Jean-Louis; Gondolf, Marc

    1993-04-01

    Copper films were applied on low sintering temperature cordierite substrates either by sputtering or screen printing. Their behaviour during thermal treatments was studied as a function of various parameters : deposition technique, thickness, firing atmosphere, physical state of the substrate (green or sintered). Films were most often broken during the treatment. In the case of screen printed films the effects of an oxydation-reduction cycle of copper are pointed out. Des films de cuivre ont été déposés sur un substrat de cordiérite à basse température de frittage par deux techniques, pulvérisation cathodique et sérigraphie. On étudie leur comportement au cours de traitements thermiques en fonction de différents paramètres : technique de déposition, épaisseur, atmosphère de traitement, état physique du substrat (cru ou fritté). On constate le plus souvent une fragmentation du film. Dans le cas des films sérigraphiés on met en évidence les effets dus à l'oxydation et à la réduction du cuivre.

  13. Protein kinase C modulation of recombinant ATP-sensitive K(+) channels composed of Kir6.1 and/or Kir6.2 expressed with SUR2B.

    PubMed

    Thorneloe, Kevin S; Maruyama, Yoshiaki; Malcolm, A Todd; Light, Peter E; Walsh, Michael P; Cole, William C

    2002-05-15

    The molecular identity of smooth muscle ATP-sensitive K(+) channels (K(ATP)) is not established with certainty. Patch clamp methods were employed to determine if recombinant K(ATP) channels composed of Kir6.1 and SUR2B subunits expressed by human embryonic kidney (HEK293) cells share an identical modulation by protein kinase C (PKC) with the vascular K(NDP) subtype of K(ATP) channel. The open probability of Kir6.1/SUR2B channels was determined before and after sequential exposure to pinacidil (50 microM) and the combination of pinacidil and phorbol 12,13-dibutyrate (PdBu; 50 nM). Treatment with PdBu caused a decline in channel activity, but this was not seen with an inactive phorbol ester, 4 alpha-phorbol 12,13-didecanoate (PdDe; 50 nM). Angiotensin II (0.1 microM) induced a similar inhibition of Kir6.1/SUR2B channels in cells expressing angiotensin AT(1) receptors. The effects of PdBu and angiotensin II were blocked by the PKC inhibitor, chelerythrine (3 microM). Purified PKC inhibited Kir6.1/SUR2B activity (in 0.5 mM ATP/ 0.5 mM ADP), and the inhibition was blocked by a specific peptide inhibitor of PKC, PKC(19-31). In contrast, PdBu increased the activity of recombinant K(ATP) channels composed of Kir6.2 and SUR2B, or the combination of Kir6.1, Kir6.2 and SUR2B subunits. The results indicate that the modulation by PKC of Kir6.1/SUR2B, but not Kir6.2/SUR2B or Kir6.1-Kir6.2/SUR2B channel gating mimics that of native vascular K(NDP) channels. Physiological inhibition of vascular K(ATP) current by vasoconstrictors which utilize intracellular signalling cascades involving PKC is concluded to involve the modulation of K(NDP) channel complexes composed of four Kir6.1 and their associated SUR2B subunits.

  14. Les effets du travail en equipe dans l'apprentissage par projets sur la motivation des etudiantes et des etudiants en formation des ingenieurs

    NASA Astrophysics Data System (ADS)

    Fernandez, Nicolas

    Les representants des secteurs industriels et les, milieux professionnels en Amerique du Nord reprochaient aux universites de former des ingenieurs avec peu d'experience pratique en resolution de problemes et en conception. Quelques programmes de genie ont alors mis en place le travail en equipe dans l'apprentissage par projets. Beaucoup d'ecrits font valoir les benefices de l'apprentissage par projets sur la motivation des etudiants. Or, ces benefices commencent a peine a faire l'objet de recherches visant a produire des donnees probantes a ce sujet. Les travaux sur la motivation en contexte d'apprentissage et les modeles theoriques developpes sont issus d'environnements d'apprentissage marques par l'enseignement magistral. Le modele de la valeur attendue de la tache (Eccles et Wigfield, 1995; Neuville, 2004) et le modele du systeme-groupe (St-Arnaud, 2008) ont ete retenus pour mesurer les effets du travail en equipe dans l'apprentissage par projets sur la motivation. La recherche visait aussi a approfondir et a nuancer la comprehension de la motivation des etudiants universitaires apprenant en contexte innovant. Les sujets constituent des etudiants (n=100) travaillant sur des projets d'integration au cours des trois sessions initiales du programme de genie mecanique d'une universite canadienne. L'analyse de regression multiple revele que les construits de la motivation expliquent un tiers de la variance de l'engagement academique dans la realisation du projet d'integration. Les perceptions de l' "expectancy", de la valeur intrinseque et utilitaire sont les determinants principaux de l'engagement des etudiants. L'analyse de variance multivariee a mesures repetees indique que la motivation des etudiants pour le travail sur les projets d'integration a augmente au cours des trois sessions initiales du parcours de formation. Finalement, malgre l'absence d'interaction significative entre les variables de motivation et de l'equipe, les reponses des sujets indiquent une

  15. ATP-sensitive K(+) channels (Kir6.1/SUR1) regulate gap junctional coupling in cochlear-supporting cells.

    PubMed

    Blödow, Alexander; Begandt, Daniela; Bader, Almke; Becker, Annegret; Burghard, Alice; Kühne, Daniela; Kral, Andrej; Ngezahayo, Anaclet

    2016-07-01

    Using the double whole-cell patch-clamp technique, we found that the absence of intracellular ATP led to gap junction uncoupling in cochlear-supporting Hensen cells. The uncoupling was observed as a progressive reduction of the gap junctional electrical conductance from a starting value of approximately 40 nS to less than 0.04 nS within 10-20 min. The conductance rundown was partly avoided by at least 3 mM ATP and completely suppressed by 5 mM ATP or 5'-adenylyl-imidodiphosphate (AMP-PNP), the non-hydrolysable ATP analog, in the pipette filling solution, suggesting that ATP was needed as ligand and not as a hydrolysable energy supplier or substrate for enzymatic reactions. The effect of intracellular ATP was mimicked by the external application of barium, a nonselective blocker of inwardly rectifying K(+) (Kir) channels, and glibenclamide, an inhibitor of the ATP-sensitive Kir channels (KATP). Moreover a Ba(2+)-sensitive whole-cell inward current was observed in absence of internal ATP. We propose that the internal ATP kept the KATP channels in a closed state, thereby maintaining the gap junction coupling of Hensen cells. The immunostaining of guinea pig cochlear tissue revealed for the first time the expression of the KATP channel subunits Kir6.1 and SUR1 in Hensen cells and supported the proposed hypothesis. The results suggest that KATP channels, as regulator of the gap junction coupling in Hensen cells, could be the physiological link between the metabolic state of the supporting cells and K(+) recycling in the organ of Corti. PMID:27030354

  16. K-Ar ages confirm Pliocene age for oldest Neogene marine strata near Loreto, Baja California Sur, Mexico

    SciTech Connect

    McLean, H.

    1987-05-01

    Beds of pumiceous tuff interbedded with mollusk-rich sedimentary rocks provide new age constraints on the timing of the late Neogene subsidence and marine transgression a few kilometers north of Loreto, Baja California Sur, Mexico. The lower part of the Neogene section consists of approximately 1500 m of early to middle Miocene nonmarine volcanic-derived sandstone, breccia, and porphyritic andesite and dacite lavas, called the Comondu Formation or Comondu Group by previous workers. The Miocene rocks are unconformably overlain by nearly 1000 m of predominantly marine sandstone, siltstone, conglomerate, coquina, and tuff of Pliocene age. This 1000-m section grades upward from unfossiliferous fanglomerate, sandstone, and pelitic red beds that are interpreted to be nonmarine into mollusk-rich marine strata; this sequence indicates that marine transgression occurred within the Pliocene section. Plagioclase and hornblende from three pumiceous tuff beds stratigraphically located near the base, middle, and top of the marine section yield K-Ar ages of 3.2, 1.9, and 1.8 Ma, respectively; these ages are similar to Pliocene ages indicated by reconnaissance studies of ostracods, diatoms, and foraminifers. The diatoms indicate open-ocean waters and the foraminifers indicate outer shelf depth. Ostracods, oysters, pectens, and other fossil bivalves seem to indicate a shallow-water embayment. Lateral distribution of nonmarine and marine facies suggests a paleoenvironment in which alluvial fans fed coarse debris into a series of coastal fan deltas. The Pliocene basin may have been a largely landlocked embayment similar to the modern Bahia Concepcion, located 70 km north of Loreto. Marine and volcanic rocks are assumed to be associated with the opening of the Gulf of California. If this assumption is correct, the beds near Loreto suggest that the opening occurred during the Pliocene.

  17. Transmission Sur Fibres Optiques Dans Un Systeme D'Archivage Et De Communication D'Images Pour Des Applications Medicales

    NASA Astrophysics Data System (ADS)

    Aaron, Gilles; Bonnard, Rene

    1984-03-01

    Dans l'hOpital, le besoin d'un reseau de communication electronique ne cesse de crottre au fur et a mesure de la numerisation des images. Ce reseau local a pour but de relier quelques sources d'images telles la radiologie numerique, la tomodensitometrie, la resonance magnetique nucleaire, l'echographie ultraso-nore etc..., a un systme d'archivage. Des consoles de visualisation interacti-ves peuvent etre utilisees dans les salles d'examens, les bureaux des medecins et les services de soins. Dans un tel systme, trois caracteristiques princi-pales doivent etre prises en compte le debit, la longueur du cable et le nombre de connexions. - Le debit est tr?)s important, en effet, un temps de reponse maxima de quel-ques secondes doit etre garanti pour des images de plusieurs millions d'ele-ments binaires. - La distance entre connexions peut etre de quelques km dans certains grands hopitaux. - Le nombre de connexions au reseau ne depasse jamais quelques dizaines car les sources d'images et les unites de traitement representent des materiels importants, par ailleurs les consoles de visualisation simples peuvent etre groupees en grappe. Toutes ces conditions sont remplies par les transmissions sur fibres optiques. Selon la topologie et la methode d'accNs, deux solutions peuvent etre envisa-gees : - Anneau actif - Etoile active ou passive Enfin, les developpements de Thomson-CSF en composants pour transmissions optiques pour les grands reseaux de tel4distribution nous apportent un support technologique et une production de masse qui diminuera les collts du materiel.

  18. ATP-sensitive K(+) channels (Kir6.1/SUR1) regulate gap junctional coupling in cochlear-supporting cells.

    PubMed

    Blödow, Alexander; Begandt, Daniela; Bader, Almke; Becker, Annegret; Burghard, Alice; Kühne, Daniela; Kral, Andrej; Ngezahayo, Anaclet

    2016-07-01

    Using the double whole-cell patch-clamp technique, we found that the absence of intracellular ATP led to gap junction uncoupling in cochlear-supporting Hensen cells. The uncoupling was observed as a progressive reduction of the gap junctional electrical conductance from a starting value of approximately 40 nS to less than 0.04 nS within 10-20 min. The conductance rundown was partly avoided by at least 3 mM ATP and completely suppressed by 5 mM ATP or 5'-adenylyl-imidodiphosphate (AMP-PNP), the non-hydrolysable ATP analog, in the pipette filling solution, suggesting that ATP was needed as ligand and not as a hydrolysable energy supplier or substrate for enzymatic reactions. The effect of intracellular ATP was mimicked by the external application of barium, a nonselective blocker of inwardly rectifying K(+) (Kir) channels, and glibenclamide, an inhibitor of the ATP-sensitive Kir channels (KATP). Moreover a Ba(2+)-sensitive whole-cell inward current was observed in absence of internal ATP. We propose that the internal ATP kept the KATP channels in a closed state, thereby maintaining the gap junction coupling of Hensen cells. The immunostaining of guinea pig cochlear tissue revealed for the first time the expression of the KATP channel subunits Kir6.1 and SUR1 in Hensen cells and supported the proposed hypothesis. The results suggest that KATP channels, as regulator of the gap junction coupling in Hensen cells, could be the physiological link between the metabolic state of the supporting cells and K(+) recycling in the organ of Corti.

  19. Considérations nosographiques sur le délire d'infestation parasitaire à travers trois observations cliniques

    PubMed Central

    Berhili, Nabil; Bout, Amine; Hlal, Hayat; Aarab, Chadya; Aalouane, Rachid; Rammouz, Ismail

    2016-01-01

    Le syndrome d'Ekbom, ou délire d'infestation parasitaire, est une pathologie rare, caractérisée par la conviction inébranlable d'avoir une peau infestée d'insectes ou de parasites. Il s'agit d'un délire monothématique à mécanisme hallucinatoire qui touche typiquement les femmes d’âge avancé. Nous rapportons les cas de trois patients qui présentent un délire d'infestation parasitaire dans des contextes cliniques différents. Le premier patient souffre d'un délire d'infestation isolé correspondant à la forme décrite par Karl Ekbom. Le deuxième cas présente un délire d'infestation secondaire, s'inscrivant dans le cadre d'une leuco-encéphalopathie de type CADASIL. Enfin, le troisième patient se présente dans un tableau évocateur d'un épisode dépressif avec une caractéristique psychotique qui intègre le délire d'infestation. Ces trois vignettes cliniques illustrent parfaitement le caractère trans-nosographique de ce syndrome ainsi que les difficultés de prise en charge de ces patients, tant au niveau de l'alliance thérapeutique que sur le plan des choix en matière de traitement pharmacologiques. PMID:27642468

  20. Boron and strontium isotope compositions of groundwater from the La Paz arid coastal aquifer, Baja California Sur, Mexico

    NASA Astrophysics Data System (ADS)

    Mahlknecht, Jürgen; Rosner, Martin; Meixner, Anette

    2016-04-01

    In groundwater studies boron and strontium isotopic compositions can be used to identify natural and anthropogenic sources as well as processes related to groundwater recharge, flow and mixing. The La Paz arid costal aquifer in Baja California Sur, Mexico, is the most important source of drinking and irrigation water for La Paz area and suffers from anthropogenic contamination and intensive exploitation of the aquifer causing seawater intrusion and general groundwater abatement. The relatively un-radiogenic 87Sr/86Sr isotope ratios of the La Paz groundwater range in a narrow field between 0.7054 and 0.7062. In contrast to strontium the boron isotope composition displays a large variability between +27 and +55 permil d11B. The relatively low 87Sr/86Sr ratios of the La Paz groundwater highlight a significant contribution of strontium derived from local terrestrial sediments and igneous rocks with known 87Sr/86Sr ratios between 0.705 and 0.7035. The large variability of d11B values indicate that multiple sources and processes determine the boron isotope composition of La Paz groundwater. Rainwater (high d11B), seawater (~+40 permil) due to seawater intrusions, wastewater (low to medium d11B) and boron derived from the local geology (low to medium d11B) explain most of the observed groundwater d11B variability. However, d11B values higher than modern seawater point to significant boron isotope fractionation by preferential absorption of 10B onto clay minerals during the evolution of some groundwater samples. Due to low boron concentrations in rainwater a significant contribution of 11B-rich rainwater (>+40 permil) on the La Paz groundwater is unlikely.

  1. Technique distribuee de gestion de la charge sur le reseau electrique et ring-tree: Un nouveau systeme de communication P2P

    NASA Astrophysics Data System (ADS)

    Ayoub, Simon

    Le reseau de distribution et de transport de l'electricite se modernise dans plusieurs pays dont le Canada. La nouvelle generation de ce reseau que l'on appelle smart grid, permet entre autre l'automatisation de la production, de la distribution et de la gestion de la charge chez les clients. D'un autre cote, des appareils domestiques intelligents munis d'une interface de communication pour des applications du smart grid commencent a apparaitre sur le marche. Ces appareils intelligents pourraient creer une communaute virtuelle pour optimiser leurs consommations d'une facon distribuee. La gestion distribuee de ces charges intelligentes necessite la communication entre un grand nombre d'equipements electriques. Ceci represente un defi important a relever surtout si on ne veut pas augmenter le cout de l'infrastructure et de la maintenance. Lors de cette these deux systemes distincts ont ete concus : un systeme de communication peer-to-peer, appele Ring-Tree, permettant la communication entre un nombre important de noeuds (jusqu'a de l'ordre de grandeur du million) tel que des appareils electriques communicants et une technique distribuee de gestion de la charge sur le reseau electrique. Le systeme de communication Ring-Tree inclut une nouvelle topologie reseau qui n'a jamais ete definie ou exploitee auparavant. Il inclut egalement des algorithmes pour la creation, l'exploitation et la maintenance de ce reseau. Il est suffisamment simple pour etre mis en oeuvre sur des controleurs associes aux dispositifs tels que des chauffe-eaux, chauffage a accumulation, bornes de recharges electriques, etc. Il n'utilise pas un serveur centralise (ou tres peu, seulement lorsqu'un noeud veut rejoindre le reseau). Il offre une solution distribuee qui peut etre mise en oeuvre sans deploiement d'une infrastructure autre que les controleurs sur les dispositifs vises. Finalement, un temps de reponse de quelques secondes pour atteindre 1'ensemble du reseau peut etre obtenu, ce qui est

  2. Effets potentiels d’un modèle rationnel de prescription sur les dépenses nationales en santé

    PubMed Central

    Littman, Jordan; Halil, Roland

    2016-01-01

    Résumé Objectif Estimer les économies que pourrait engendrer la mise en œuvre d’un modèle rationnel de prescription pour des classes de médicaments équivalents sur les plans de l’efficacité, de la toxicité et de la commodité. Conception L’Institut canadien d’information sur la santé a fourni des renseignements sur les 10 principales classes de médicaments en fonction des dépenses annuelles qui leur sont attribuables. Ces classes ont été examinées en vue de leur inclusion potentielle dans l’étude selon qu’il était possible de comparer les médicaments à l’intérieur d’une même classe. Lorsqu’à la suite d’une recherche documentaire, une équivalence a été établie en fonction de l’efficacité, de la toxicité et de la commodité des médicaments, les données annuelles sur les prescriptions ont été recueillies à partir de la base de données du Système national d’information sur l’utilisation des médicaments prescrits. Les économies potentielles de coûts ont ensuite été calculées en comparant les parts de marché actuelles avec les parts potentielles futures de ce marché. Contexte Le Canada. Principaux paramètres à l’étude Les différences estimées dans les dépenses que produirait un modèle rationnel de prescription. Résultats Une équivalence a été établie sur les plans de l’efficacité, de la toxicité et de la commodité dans les classes de statines, d’inhibiteurs de la pompe à protons, d’inhibiteurs de l’enzyme de conversion de l’angiotensine et d’inhibiteurs sélectifs du recaptage de l’angiotensine. Les dépenses annuelles totales dans ces classes se situent à 856 millions $ dans les programmes publics de médicaments et à 1,97 milliard $ environ à l’échelle nationale. Grâce à des prescriptions rationnelles, on estime que les économies annuelles pourraient atteindre 222 millions $ pour les programmes publics et 521 millions $ à l’échelle nationale. Conclusion La

  3. Effets de L'anisotropie Cristalline et du Desordre Controle Sur les Proprietes Optiques et Phononiques des Composes Semiconducteurs ZIRCONIUM(1-X) Hafnium(x) SOUFRE(3)

    NASA Astrophysics Data System (ADS)

    Ait-Ouali, Abderrahmane

    Dans ce travail, nous presentons l'etude de l'effet de l'anisotropie cristalline et du desordre substitutionnel controle sur les proprietes electroniques et vibrationnelles des composes semiconducteurs Zr_{rm 1-x}Hf_{x} S_3. Les proprietes phononiques sont ete etudiees en spectroscopie Raman. Les mesures systematiques des spectres polarises de tous les composes nous ont permis d'identifier tous les phonons predits par la theorie des groupes et de suivre l'evolution de leur frequence avec la concentration de hafnium. L'analyse plus approfondie par un procede de lissage des spectres nous a permis detudier l'effet du desordre controle sur la largeur des modes phononiques. Les resultats de cette analyse ont ete confrontes aux predictions d'un modele developpe pour une chai ne diatomique desordonnee et ameliore suite a nos observations experimentales. La forme en cloche predite par ce dernier pour la variation de la largeur du mode optique de la chai ne est observee pour trois phonons de symetrie Bg. L'accord est excellent pour X > 0.5 pour deux des trois modes et ce, sans aucun parametre ajustable. Cette etude nous a permis, d'une part, de conclure que les modes Bg se comportent comme s'ils etaient sur une chai ne isolee et que, par consequent, les deux chai nes composant la cellule unite de nos cristaux sont tres faiblement liees et, d'autre part, de confirmer la symetrie des modes telle que deduite des spectres polarises. Les proprietes electroniques du ZrS_3 ont ete etudiees par des mesures polarisees du coefficient d'absorption pres de son gap indirect. L'evolution des spectres avec la temperature nous a permis d'identifier deux gaps paralleles differents et un gap perpendiculaire confirmant ainsi le modele de la structure de bande base sur les etats electroniques moleculaires de l'ion (S _2)^2. L'analyse detaillee des differentes structures du coefficient d'absorption indique clairement un caractere bidimensionnel du gap indirect. L'effet du desordre

  4. Differential mechanisms of Cantú syndrome-associated gain of function mutations in the ABCC9 (SUR2) subunit of the KATP channel.

    PubMed

    Cooper, Paige E; Sala-Rabanal, Monica; Lee, Sun Joo; Nichols, Colin G

    2015-12-01

    Cantú syndrome (CS) is a rare disease characterized by congenital hypertrichosis, distinct facial features, osteochondrodysplasia, and cardiac defects. Recent genetic analysis has revealed that the majority of CS patients carry a missense mutation in ABCC9, which codes for the sulfonylurea receptor SUR2. SUR2 subunits couple with Kir6.x, inwardly rectifying potassium pore-forming subunits, to form adenosine triphosphate (ATP)-sensitive potassium (K(ATP)) channels, which link cell metabolism to membrane excitability in a variety of tissues including vascular smooth muscle, skeletal muscle, and the heart. The functional consequences of multiple uncharacterized CS mutations remain unclear. Here, we have focused on determining the functional consequences of three documented human CS-associated ABCC9 mutations: human P432L, A478V, and C1043Y. The mutations were engineered in the equivalent position in rat SUR2A (P429L, A475V, and C1039Y), and each was coexpressed with mouse Kir6.2. Using macroscopic rubidium ((86)Rb(+)) efflux assays, we show that K(ATP) channels formed with P429L, A475V, or C1039Y mutants enhance K(ATP) activity compared with wild-type (WT) channels. We used inside-out patch-clamp electrophysiology to measure channel sensitivity to ATP inhibition and to MgADP activation. For P429L and A475V mutants, sensitivity to ATP inhibition was comparable to WT channels, but activation by MgADP was significantly greater. C1039Y-dependent channels were significantly less sensitive to inhibition by ATP or by glibenclamide, but MgADP activation was comparable to WT. The results indicate that these three CS mutations all lead to overactive K(ATP) channels, but at least two mechanisms underlie the observed gain of function: decreased ATP inhibition and enhanced MgADP activation. PMID:26621776

  5. Differential mechanisms of Cantú syndrome–associated gain of function mutations in the ABCC9 (SUR2) subunit of the KATP channel

    PubMed Central

    Cooper, Paige E.; Sala-Rabanal, Monica; Lee, Sun Joo

    2015-01-01

    Cantú syndrome (CS) is a rare disease characterized by congenital hypertrichosis, distinct facial features, osteochondrodysplasia, and cardiac defects. Recent genetic analysis has revealed that the majority of CS patients carry a missense mutation in ABCC9, which codes for the sulfonylurea receptor SUR2. SUR2 subunits couple with Kir6.x, inwardly rectifying potassium pore-forming subunits, to form adenosine triphosphate (ATP)-sensitive potassium (KATP) channels, which link cell metabolism to membrane excitability in a variety of tissues including vascular smooth muscle, skeletal muscle, and the heart. The functional consequences of multiple uncharacterized CS mutations remain unclear. Here, we have focused on determining the functional consequences of three documented human CS-associated ABCC9 mutations: human P432L, A478V, and C1043Y. The mutations were engineered in the equivalent position in rat SUR2A (P429L, A475V, and C1039Y), and each was coexpressed with mouse Kir6.2. Using macroscopic rubidium (86Rb+) efflux assays, we show that KATP channels formed with P429L, A475V, or C1039Y mutants enhance KATP activity compared with wild-type (WT) channels. We used inside-out patch-clamp electrophysiology to measure channel sensitivity to ATP inhibition and to MgADP activation. For P429L and A475V mutants, sensitivity to ATP inhibition was comparable to WT channels, but activation by MgADP was significantly greater. C1039Y-dependent channels were significantly less sensitive to inhibition by ATP or by glibenclamide, but MgADP activation was comparable to WT. The results indicate that these three CS mutations all lead to overactive KATP channels, but at least two mechanisms underlie the observed gain of function: decreased ATP inhibition and enhanced MgADP activation. PMID:26621776

  6. Investigation of the role of the BAM complex and SurA chaperone in outer-membrane protein biogenesis and type III secretion system expression in Salmonella.

    PubMed

    Fardini, Yann; Trotereau, Jérôme; Bottreau, Elisabeth; Souchard, Charlène; Velge, Philippe; Virlogeux-Payant, Isabelle

    2009-05-01

    In Escherichia coli, the assembly of outer-membrane proteins (OMP) requires the BAM complex and periplasmic chaperones, such as SurA or DegP. Previous work has suggested a potential link between OMP assembly and expression of the genes encoding type-III secretion systems. In order to test this hypothesis, we studied the role of the different lipoproteins of the BAM complex (i.e. BamB, BamC, BamD and BamE), and the periplasmic chaperones SurA and DegP, in these two phenotypes in Salmonella. Analysis of the corresponding deletion mutants showed that, as previously described with the DeltabamB mutant, BamD, SurA and, to a lesser extent, BamE play a role in outer-membrane biogenesis in Salmonella Enteritidis, while the membrane was not notably disturbed in DeltabamC and DeltadegP mutants. Interestingly, we found that BamD is not essential in Salmonella, unlike its homologues in Escherichia coli and Neisseria gonorrhoeae. In contrast, BamD was the only protein required for full expression of T3SS-1 and flagella, as demonstrated by transcriptional analysis of the genes involved in the biosynthesis of these T3SSs. In line with this finding, bamD mutants showed a reduced secretion of effector proteins by these T3SSs, and a reduced ability to invade HT-29 cells. As DeltasurA and DeltabamE mutants had lower levels of OMPs in their outer membrane, but showed no alteration in T3SS-1 and flagella expression, these results demonstrate the absence of a systematic link between an OMP assembly defect and the downregulation of T3SSs in Salmonella; therefore, this link appears to be related to a more specific mechanism that involves at least BamB and BamD. PMID:19372159

  7. Superposition tridimensionnelle (3-D) sur la base du crâne pour l’évaluation longitudinale des effets de la croissance et du traitement

    PubMed Central

    Cevidanes, Lucia H.S.; Styner, Martin; Proffit, William R.; Ngom, Traduit par Papa Ibrahima

    2010-01-01

    RÉSUMÉ – Pour évaluer les modifications liées à la croissance ou au traitement, il est nécessaire de superposer les céphalogrammes successifs sur une structure stable. En céphalométrie bidimensionnelle (2-D), la base du crâne est souvent utilisée pour les superpositions parce que les changements qu’elle subit après le développement cérébral sont mineurs. Toutefois, sur les céphalogrammes de profil et de face, les points de repère basicraniens sont peu fiables. Dans cet article, nous présentons une nouvelle méthode de superposition tridimensionnelle (3-D) basée sur un enregistrement entièrement automatisé des intensités de voxels, au niveau de la surface de la base du crâne. Le progiciel utilisé permet l’évaluation quantitative des modifications qui apparaissent dans le temps, grâce au calcul de la distance euclidienne entre les surfaces du modèle tridimensionnel. Il permet également l’appréciation visuelle de l’emplacement et de l’importance des modifications au niveau des maxillaires, grâce à une surimpression graphique. Les modifications sont visualisées par comparaison à des tables de correspondance de couleur. On peut ainsi réaliser une étude détaillée des modes d’adaptation chez les patients dont la croissance et/ou le traitement ont provoqué des modifications squelettiques cliniquement significatives. PMID:19954732

  8. D'Eichthal and Urbain's "Lettres sur la race noire et la race blanche": race, gender, and reconciliation after slave emancipation.

    PubMed

    Andrews, Naomi J

    2011-01-01

    This article is a close reading of Gustave D'Eichthal and Ishmayl Urbain's Lettres sur la race noire et la race blanche (1839), written during the decade prior to the "second" French emancipation in 1848. The article argues that the hierarchical gendering of race described in the letters is reflective of metropolitan concerns about potential for social disorder accompanying slave emancipation in the French colonies. In arguing for social reconciliation through interracial marriage and its offspring, the symbolically charged figure of the mulatto, the authors deployed gendered and familial language to describe a stable post-emancipation society.

  9. L’opinion des étudiants en médecine de Québec sur les punitions corporelles

    PubMed Central

    Labbé, Jean; Laflamme, Nathalie; Makosso-Kallyth, Sun

    2012-01-01

    OBJECTIF : L’objectif de la présente étude est de décrire l’opinion des étudiants en médecine de l’Université Laval sur le sujet controversé des punitions corporelles envers les enfants. MÉTHODOLOGIE : Un sondage a été réalisé auprès des étudiants en quatrième année de médecine de l’Université Laval pendant cinq années consécutives, soit de l’année scolaire 2006–2007 jusqu’à celle de 2010–2011 inclusivement, à l’occasion d’un séminaire portant sur la maltraitance envers les enfants. RÉSULTATS : Sur les 712 étudiants interrogés, 74 % étaient de sexe féminin et 91 % étaient âgés de moins de 30 ans. Concernant les punitions corporelles envers les enfants, 22 % des répondants s’y sont déclarés favorables. Plus de garçons que de filles se sont prononcés en faveur de cette pratique disciplinaire, soit 31 % des garçons par rapport à 18 % des filles respectivement (RC rajusté = 2,2, IC 95 % :1,4 à 3,4; p=0,0003). Près de 36 % des étudiants ayant eu des punitions corporelles y étaient favorables, comparativement à seulement 4 % de ceux qui n’avaient pas connu cette forme de discipline (RC rajusté = 16,5, IC 95 % :8,6 à 31,4; p<0,0001). Parmi ceux qui ont mentionné avoir été victimes d’abus physique, 25 % se sont déclarés en faveur de cette pratique, ce qui est similaire au 21 % observés chez ceux qui n’en ont pas été victimes (p=0,52). CONCLUSION : Alors que plusieurs organismes médicaux se sont prononcés contre l’utilisation des punitions corporelles, plus d’un futur médecin sur cinq à Québec se déclare favorable à cette méthode disciplinaire et pourrait influencer la conduite des parents en ce sens. PMID:24179417

  10. Scénarios dynamiques d'une fibre dopée erbium fonctionnant sur deux longueurs d'onde

    NASA Astrophysics Data System (ADS)

    Bérisson, W.; Besnard, P.; Ginovart, F.; Le Boudecl, P.; Sanchez, F.; Stéphan, G. M.

    2002-06-01

    Nous montrons la sensibilité à l'anisotropie de pompe des diagrammes de bifurcation d'une fibre dopée erbium fonctionnant sur deux longueurs d'onde. Un très bon accord entre les diagrammes de bifurcation expérimentaux et ceux obtenus théoriquement a été obtenu. De nouveaux types de bistabilités (3T-chaos et IT-chaos) sont mis en évidence pour ces systèmes.

  11. Evaluation du niveau de connaissance des patients sur la gestion du traitement par les antis vitamines K dans le service de cardiologie de Ouagadougou

    PubMed Central

    Samadoulougou, André; Temoua Naibe, Dangwé; Mandi, Germain; Yameogo, Relwendé Aristide; Kabore, Elisé; Millogo, Georges; Yameogo, Nobila Valentin; Kologo, Jonas Koudougou; Thiam/Tall, Anna; Toguyeni, Boubacar Jean Yves; Zabsonre, Patrice

    2014-01-01

    Introduction Les antivitamines K (AVK), traitement anticoagulant oral le plus largement prescrit, posent un réel problème de santé publique du fait de leur risque iatrogène. L'objectif de cette étude était de préciser le niveau de connaissance des patients sur la gestion de leur traitement par les AVK. Méthodes Il s'est agi d'une enquête transversale descriptive réalisée au CHU-Yalgado Ouédraogo, sur une période de 03 mois : du 1er mars au 31 mai 2012. Un questionnaire a été administré aux patients bénéficiant d'un traitement AVK depuis au moins un mois. Résultats Soixante-dix patients ont été inclus dans l'étude dont 30 hommes. L'âge moyen était de 49 ans ± 16 ans. Les cardiopathies et la maladie thromboembolique veineuse justifiant l'institution du traitement AVK étaient retrouvées respectivement dans 58,6% et 41,4% des cas. Le nom de l'AVK et la raison exacte du traitement étaient connus respectivement dans 91,4% et 67,1% des cas. Plus de la moitié des patients (68,6%) savaient que les AVK rendaient le sang plus fluide. Quarante-six patients (65,7%) citaient l'INR comme examen biologique de surveillance du traitement et seulement 28 patients (40%) connaissaient les valeurs cibles. La majorité des patients ne connaissait pas les risques encourus en cas de surdosage (72,8%) et de sous-dosage (71,4%). Une automédication par anti-inflammatoire non stéroïdien était signalée par 18 patients (25,7%). Les choux (74,3%) et la laitue (62,9%), aliments à consommer avec modération, étaient les plus cités. Conclusion Les connaissances des patients sur la gestion des AVK étaient fragmentaires et insuffisantes pour assurer la sécurité et l'efficacité du traitement. La création d'un programme d'éducation thérapeutique sur les AVK s'avère alors nécessaire. PMID:25870741

  12. Conceptualization of groundwater flow of a coastal arid aquifer using isotopic and chemical tools: La Paz, Baja California Sur, Mexico

    NASA Astrophysics Data System (ADS)

    Tamez-Melendez, Carol; Hernández-Antonio, Arturo; Mahlknecht, Jürgen

    2016-04-01

    Groundwater from the La Paz coastal aquifer in Baja California Sur, Mexico, is the main source of drinking water for the local population. Due to its proximity to the coast, sea water intrusion is the main factor of salinization of groundwater. Other geochemical processes also affect the quality of the aquifer threating its vulnerability. Forty-seven samples were analyzed for ion chemistry and isotopes. A hierarchical cluster analysis was performed for a better interpretation resulting in three main groups and proved for geographical correspondence. Deuterium and d18O ranged from -82 to -52.1 and from -11.6 to -7 permil, respectively, showing that the main recharge originates in the Sierra el Novillo, flowing toward SE-NW direction and in accordance to deuterium excess (d) high evaporation effects (d>10‰) are mostly in the middle portion of the study area and in El Centenario due to high kinetic isotope fractioning related to elevated temperatures. Hydrogeochemistry analyses demonstrated salinization mainly due to sea water intrusion and in second instance due water-rock interaction, where enrichment of Na+ (ranges from 35.7 to 1089 mg/L-1) was present in some samples probably due to weathering of silicates and/or cation exchange in soils with Ca2+ (27.7 to 658 mg/L-1) at clay-surfaces. High concentrations of NO3-2 (ranges from 1.4 to 48.8 mg/L-1), Cl- (ranges from 54.4 to 2960 mg/L-1) and Na+ show that anthropogenic input is mainly coming from an agricultural area (El Centenario-Chametla) where heavy groundwater extractions are made for irrigational purposes, lowering the groundwater table up to 10 m and consequently promoting upconing and salinity concentrations (NaCl). Carbon-13 and radiocarbon ranged from -12.3 to -9.1‰ and from 29.5 to 100.4 pmC, respectively. Distribution of ages (up to ~5000 years) indicates two flow trends (E-W and SE-NW).

  13. Sedimentologic Assessment of a Makran Tsunami Depsoit in Sur Lagoon Using High- Resolution Particle Size Distributions (PSDs) and Cluster Analysis

    NASA Astrophysics Data System (ADS)

    Reinhardt, E. G.; Donato, S. V.; Boyce, J. I.; Pilarczyk, J. E.

    2008-12-01

    The Makran subduction zone, which conveys the Arabian plate beneath Eurasia, has a poorly understood potential to generate tsunamis that would strike Oman, Iran, Pakistan, and India. The 1945 Makran earthquake (M 8.1), which resulted from a rupture 100-150 km long, caused a tsunami that reached heights of 5-15 m and killed an estimated 3,000 people on the coast of what is now Pakistan. The possibility of a full- length Makran rupture, approx. 750 km long, remains untested. The arid coastlines of the northern Arabian Sea (including parts of Oman, Iran, Pakistan and India) have had little attention regarding paleo-tsunami research. They lack the main environments where tsumani deposits have been found on temperate shores: tidal marshes, peatlands, and coastal lakes. Instead they offer sandy lagoons and salt flats where tsunami-laid sand sheets can be removed by wind, confused with the deposits of wadi sheet floods, and obliterated by burrowing crabs. Recent research has shown that a shell bed in Oman, likely from the 1945 tsunami (Sur Lagoon - Donato et al., 2008), contained distinctive molluscan assemblages and taphonomy, showing promise as a tsunami indicator for these arid settings. However, the large size of the molluscs is problematic in cores with small sample sizes, as the taphonomic data might not be representative enough to determine a tsunami origin without the use of additional proxies. Further characterization of the shell bed in Oman utilized high-resolution (cm scale) PSDs and Q-mode cluster analysis to identify the tsunami bed in cores (n=8). Results showed that the shell bed was more poorly sorted, and heterogeneous than the background lagoonal sediments. The tsunami bed thickness correlated generally with the thickness of the shell-bed, however cluster analysis of the particle size distributions (PSDs) extended the unit several centimeters above or below the shell-bed in some cores. The use of the full PSD (94 size classes) better characterized the

  14. Mise à jour sur le nouveau vaccin 9-valent pour la prévention du virus du papillome humain

    PubMed Central

    Yang, David Yi; Bracken, Keyna

    2016-01-01

    Résumé Objectif Informer les médecins de famille quant à l’efficacité, à l’innocuité, aux effets sur la santé publique et à la rentabilité du vaccin 9-valent contre le virus du papillome humain (VPH). Qualité des données Des articles pertinents publiés dans PubMed jusqu’en mai 2015 ont été examinés et analysés. La plupart des données citées sont de niveau I (essais randomisés et contrôlés et méta-analyses) ou de niveau II (études transversales, cas-témoins et épidémiologiques). Des rapports et recommandations du gouvernement sont aussi cités en référence. Message principal Le vaccin 9-valent contre le VPH, qui offre une protection contre les types 6, 11, 16, 18, 31, 33, 45, 52 et 58 du VPH, est sûr et efficace et réduira encore plus l’incidence des infections à VPH, de même que les cas de cancer lié au VPH. Il peut également protéger indirectement les personnes non immunisées par l’entremise du phénomène d’immunité collective. Un programme d’immunisation efficace peut prévenir la plupart des cancers du col de l’utérus. Les analyses montrent que la rentabilité du vaccin 9-valent chez les femmes est comparable à celle du vaccin quadrivalent original contre le VPH (qui protège contre les types 6, 11, 16 et 18 du VPH) en usage à l’heure actuelle. Toutefois, il faut investiguer plus en profondeur l’utilité d’immuniser les garçons avec le vaccin 9-valent contre le VPH. Conclusion en plus d’être sûr, le vaccin 9-valent protège mieux contre le VPH que le vaccin quadrivalent. Une analyse coûtefficacité en favorise l’emploi, du moins chez les adolescentes. Ainsi, les médecins devraient recommander le vaccin 9-valent à leurs patients plutôt que le vaccin quadrivalent contre le VPH.

  15. Renaud Paulian et le programme du CNRS sur les hautes montagnes à Madagascar: étage vs domaine

    PubMed Central

    Guillaumet, Jean-Louis; Betsch, Jean-Marie; Callmander, Martin W.

    2011-01-01

    Résumé Le programme intitulé « Étude des écosystémes montagnards dans la région malgache» (RCP 225/CNRS; responsable: Recteur Renaud Paulian) avait pour ambition de dégager leurs caractères généraux, l'origine des éléments constitutifs et de tester la validité d'un Domaine malgache des Hautes Montagnes proposé par Humbert dès 1951. De 1970 à 1973, trois campagnes (Andringitra; Chaînes anosyennes et Ankaratra; Itremo, Ibity et Marojejy) ont permis une caractérisation écologique des milieux particuliers ainsi que des analyses de systématique sur certains taxa connus pour leur intérêt biogéographique. La succession altitudinale des formations végétales, définies par des critères physionomiques et structuraux, est précisée par massif. Le dernier étage caractérisé par le fourré éricoïde et ses groupements associés ne correspond pas à l'Étage des Hautes Montagnes de l'Est africain. Des groupes de la faune (invertébrés hexapodes: Collemboles et Dermaptères) indiquent une disjonction entre les massifs du Nord (Tsaratanana, Marojejy), ceux du Centre et du Sud; des éléments de la flore (Pandanaceae, Araliaceae, Asteraceae) sont en cours d'analyse dans le même sens. Le Domaine des Hautes montagnes à Madagascar est une réalité écologique mais ne peut être défini floristiquement; chaque massif montagneux est une entité phytogéographique d'étages de végétation interdépendants inclus dans les différents Sous-Domaines du Centre. Les groupes peu mobiles de la faune indiquent globalement une dépendance trophique et bioclimatique (effet tampon du climat intraforestier) vis-à-vis des étages de végétation, mais peuvent réagir à des microclimats locaux par des décalages à leurs limites. PMID:21731422

  16. L'endométriose périnéale profonde sur cicatrice d’épisiotomie: à propos d'un cas rare

    PubMed Central

    Laadioui, Meriem; Alaoui, Fdili; Jayi, Sofia; Bouguern, Hakima; Chaara, Hikmat; Melhouf, Moulay Aabdelilah

    2013-01-01

    Parmi les localisations rares de l'endométriose sur cicatrice, celle du périnée demeure exceptionnelle, l'origine en est souvent iatrogène (épisiotomie). Nous rapportons le cas d'une patiente présentant une douleur cyclique, au niveau de la cicatrice d’épisiotomie. Avec à l'examen clinique une masse de 3,5 cm de grand diamètre au niveau de la cicatrice d’épisiotomie. L’écho périnéale a objectivé une image hypoéchgène hétérogène non vascularisée en regard de la cicatrice d’épisiotomie faisant 3,23/1cm. L'excision de la lésion a été réalisée et l’étude anatomopathologique a confirmé le diagnostic d'endométriose. Les suites postopératoires étaient simples avec un recul de 3 mois sans récidive de la douleur ni de la masse. A travers notre cas et une revue de la littérature, nous insistons sur les la nécessité du diagnostic clinique et d'une prise en charge précoce en vue d'améliorer le pronostic de cette entité rare. PMID:24778749

  17. Etude de l'influence de la temperature et de l'humidite sur les proprietes mecaniques en traction des fibres de chanvre et de coco

    NASA Astrophysics Data System (ADS)

    Ho Thi, Thu Nga

    L'objectif de cette etude fut d'etablir l'effet de l'humidite et de la temperature sur la resistance en traction et le module elastique des fibres de chanvre et de coco. Deux etudes ont ete realisees afin d'atteindre cet objectif. La premiere vise l'absorption de l'humidite dans ces fibres en exposition dans l'air (de 0%RH a 80%RH) ainsi que l'absorption de l'eau dans ces fibres immergees dans l'eau aux differentes temperatures. La deuxieme consiste a mesurer la resistance en traction et le module elastique de ces fibres sous differentes conditions d'humidite et de temperature. En basant sur les resultats experimentaux obtenus, les methodes semi empiriques et de reseaux de neurones ont ete utilisees pour but de predire les proprietes en traction (resistance et module d'elasticite) des fibres de chanvre et de coco sous l'influence de l'humidite et de la temperature.

  18. Un essai contrôlé randomisé: effet du port de chaussures à talons hauts sur le squelette appendiculaire inferieur

    PubMed Central

    Koussihouèdé, Fifamè Eudia Nadège; Falola, Jean-Marie; Fousseni, El-Mansour Barres

    2015-01-01

    Introduction Véritable attribut de la féminité, le port de chaussures à talons est devenu une exigence professionnelle dans certaines structures des pays en développement comme le Bénin. L'objectif de ce travail est de déterminer les effets spécifiques du port de chaussures à talons hauts sur le squelette appendiculaire inférieur. Méthodes Des examens radiographiques de face et de profil de la cheville et du genou ont été effectués sur 122 femmes volontaires, âgées en moyenne de 25,09 ± 1,34 ans et ayant les genu varum qui ont participé à cette étude. Résultats Les résultats ont indiqué une augmentation significative de l’écart inter malléolaire, de l’écart inter condylien, de l'angle antérieur du pied et de l'angle fémoro-patellaire. Une diminution significative de l'angle postérieur du pied a été constatée. Conclusion Le port de chaussures à talons hauts est l'une des causes de la gonarthrose, des troubles des articulations de la cheville et du pied. PMID:26113922

  19. Mesure des stades de developpement du sapin baumier (Abies balsamea [L.] Mill.) par teledetection des maxima locaux sur images a tres haute resolution

    NASA Astrophysics Data System (ADS)

    Demers, Alain

    L'objectif principal de cette these est d'identifier les parametres cles pour lier le developpement morphologique de la cime du sapin baumier (Abies balsamea [L.] Mill.) aux patrons de reflectance qu'elle genere sur une image aerienne a haute resolution. La quantite et la distribution spatiale des aiguilles dans le sapin dependent de la structure des branches. Un mecanisme de ramification particulier (la reiteration) ressort comme le parametre cle pour lier l'augmentation de la biomasse foliaire et la forme de la branche. Les reiterats forment des agglomerats de feuillage qui engendrent des inegalites dans les patrons de reflectance de la cime. La reflectance est plus elevee ou il y a une forte concentration de reiterats (maximum local). On demontre que le developpement du sapin baumier se mesure au moyen de l'analyse des maxima locaux de la cime sur une image. La biomasse de l'arbre se mesure par la teledetection et l'analyse des patrons de reflectance de la cime, c'est-a-dire la mesure du niveau de reiteration par le decompte des maxima locaux de la cime. Cette etude demontre qu'il est possible de proceder a l'inventaire du volume de bois d'un peuplement par la teledetection de l'architecture des arbres.

  20. Que nous apprennent les petits frères et sœurs sur les signes précoces d’autisme?1

    PubMed Central

    Rogers, Sally J.

    2010-01-01

    L’objectif de cette revue est de présenter une synthèse des réponses que l’on peut actuellement apporter à la question de savoir quelles sont les premières caractéristiques comportementales qui prédisent le développement de l’autisme. L’article se centre sur 5 points : la présence de Troubles du Spectre Autistique (TSA) dans des groupes de frères et sœurs puînés d’enfants déjà diagnostiqués, les patterns et caractéristiques du développement moteur, les patterns et caractéristiques du développement social et émotionnel, les patterns et caractéristiques de la communication intentionnelle verbale et non verbale, et les patterns qui marquent le début de comportements pathognomoniques de TSA. La discussion porte sur les aspects inattendus des résultats et les pistes de recherche nouvelles qu’ils peuvent engendrer. PMID:20890377

  1. Quaternary structure of K[ssubscript ATP] channel SUR2A nucleotide binding domains resolved by synchrotron radiation X-ray scattering

    SciTech Connect

    Park, Sungjo; Terzic, Andre

    2010-05-25

    Heterodimeric nucleotide binding domains NBD1/NBD2 distinguish the ATP-binding cassette protein SUR2A, a recognized regulatory subunit of cardiac ATP-sensitive K{sup +} (K{sub ATP}) channels. The tandem function of these core domains ensures metabolism-dependent gating of the Kir6.2 channel pore, yet their structural arrangement has not been resolved. Here, purified monodisperse and interference-free recombinant particles were subjected to synchrotron radiation small-angle X-ray scattering (SAXS) in solution. Intensity function analysis of SAXS profiles resolved NBD1 and NBD2 as octamers. Implemented by ab initio simulated annealing, shape determination prioritized an oblong envelope wrapping NBD1 and NBD2 with respective dimensions of 168 x 80 x 37 {angstrom}{sup 3} and 175 x 81 x 37 {angstrom}{sup 3} based on symmetry constraints, validated by atomic force microscopy. Docking crystal structure homology models against SAXS data reconstructed the NBD ensemble surrounding an inner cleft suitable for Kir6.2 insertion. Human heart disease-associated mutations introduced in silico verified the criticality of the mapped protein-protein interface. The resolved quaternary structure delineates thereby a macromolecular arrangement of K{sub ATP} channel SUR2A regulatory domains.

  2. Developpement et validation d'un outil base sur l'acoustique geometrique pour le diagnostic du bruit de nacelle

    NASA Astrophysics Data System (ADS)

    Minard, Benoit

    De nos jours, la problématique du bruit généré par les avions est devenue un point de développement important dans le domaine de l'aéronautique. C'est ainsi que de nombreuses études sont faites dans le domaine et une première approche consiste à modéliser de façon numérique ce bruit de manière à réduire de façon conséquente les coûts lors de la conception. C'est dans ce contexte qu'un motoriste a demandé à l'université de Sherbrooke, et plus particulièrement au groupe d'acoustique de l'Université de Sherbrooke (GAUS), de développer un outil de calcul de la propagation des ondes acoustiques dans les nacelles mais aussi pour l'étude des effets d'installation. Cet outil de prédiction leur permet de réaliser des études afin d'optimiser les traitements acoustiques (« liners »), la géométrie de ces nacelles pour des études portant sur l'intérieur de la nacelle et des études de positionnement des moteurs et de design pour les effets d'installation. L'objectif de ce projet de maîtrise était donc de poursuivre le travail réalisé par [gousset, 2011] sur l'utilisation d'une méthode de lancer de rayons pour l'étude des effets d'installation des moteurs d'avion. L'amélioration du code, sa rapidité, sa fiabilité et sa généralité étaient les objectifs principaux. Le code peut être utilisé avec des traitements acoustiques de surfaces («liners») et peut prendre en compte le phénomène de la diffraction par les arêtes et enfin peut être utilisé pour réaliser des études dans des environnements complexes tels que les nacelles d'avion. Le code développé fonctionne en 3D et procéde en 3 étapes : (1) Calcul des faisceaux initiaux (division d'une sphère, demi-sphère, maillage des surfaces de la géométrie) (2) Propagation des faisceaux dans l'environnement d'étude : calcul de toutes les caractéristiques des rayons convergents (amplitude, phase, nombre de réflexions, ...) (3) Reconstruction du champ de pression en un ou

  3. Victoire sur les Maths.

    ERIC Educational Resources Information Center

    Tahta, Dick

    1993-01-01

    Presents two case studies from a book by Lusiane Weyl-Kailey in which she addresses the learning problems of 14-year-old boys from either a psychoanalytic perspective or a mathematical perspective, depending upon her diagnosis of the boys' problems. (MDH)

  4. Little Ice Age versus Present Day: Comparison of Temperature, Precipitation and Seasonality in Speleothem Records from the Han-sur-Lesse Cave, Belgium.

    NASA Astrophysics Data System (ADS)

    Vansteenberge, S.; Van Opdenbosch, J.; Van Rampelbergh, M.; Verheyden, S.; Keppens, E.; Cheng, H.; Edwards, R. L.; Claeys, P. F.

    2015-12-01

    The Proserpine stalagmite is a 2 m large, tabular-shaped speleothem located in the Han-sur-Lesse cave in Belgium. The speleothem formed over the last 1000 years and is still growing. High-accuracy U/Th datings have indicated exceptionally high growth-rates of up to 2 mm per year. This, together with a well expressed annual layering, makes the Proserpine stalagmite an ideal candidate for high-resolution paleoclimate reconstructions of the last millennium. Previous work, including over 10 years of cave monitoring, has already learned us how short-term, i.e. decadal to seasonal, climate variations are incorporated within speleothem calcite from the Han-sur-Lesse cave system. It has been shown that δ18O and δ13C stable isotopes and trace element proxies of recently formed calcite reflect seasonal variations in temperature and precipitation of the near-cave environment (Verheyden et al, 2008; Van Rampelbergh et al., 2014). Now, this knowledge was used to infer local climate parameters further back in time to the period of +/- 1620-1630 CE, corresponding to one of the cold peaks within the Little Ice Age. Speleothem calcite was sampled at sub-annual resolution, with approximately 11 samples per year, for stable isotope analysis. LA-ICP-MS and µXRF analyses resulted in time series of trace elements. Preliminary results indicate a well expressed seasonal signal in δ13C and trace element composition but a multi-annual to decadal trend in δ18O. This combined proxy study eventually enables comparison of the expression of seasonality and longer term climate variations between a Little Ice Age cold peak and Present Day. References: Verheyden, S. et al., 2008, Monitoring climatological, hydrological and geochemical parameters in the Père Noël cave (Belgium): implication for the interpretation of speleothem isotopic and geochemical time-series. International Journal of Speleology, 37(3), 221-234. Van Rampelbergh, M. et al., 2014, Seasonal variations recorded in cave

  5. Catalyseur d'hydrocraquage à base de sulfure de NiMo déposé sur une zéolithe HEMT modifiée

    NASA Astrophysics Data System (ADS)

    Baalala, M.; Becue, T.; Leglise, J.; Manoli, J. M.; van Gestel, J. N. M.; Lamotte, J.; Bensitel, M.; Goupil, J. M.; Cornet, D.

    1999-02-01

    Treating a NH4EMT zeolite with a solution of (NH4)2SiF6 at 80 °C affords a solid containing amorphous SiO2 intimately mixed with the zeolite. This acidic support EMT-Si was loaded with NiMo sulfide in order to prepare a bifunctional catalyst, which was tested for the hydrogenation of benzene and the hydrocracking of n-heptane. This NiMo/EMT-Si catalyst was found more active for hydrogenation than the analogous NiMo/HY. This is ascribed to a higher dispersion of the NiMo sulfide, which is almost equally shared between the internal mesopores in the modified EMT solid, and the fissures, which were created throughout the zeolite grains upon inserting the NiMo sulfide. The catalyst with the EMT-Si support was also found more active than the NiMo/HY for the hydrocracking of heptane, with a slightly higher selectivity into heptane isomers. Le traitement d'une zéolithe NH4EMT par une solution de (NH4)2SiF6 fournit un solide comportant une phase SiO2 amorphe intimement mélangée aux parties intactes de la zéolithe. Sur ce support acide EMT-Si, on a greffé un sulfure de NiMo afin de préparer un catalyseur bifonctionnel qui a été testé dans les réactions d'hydrogénation du benzène et d'hydrocraquage du n-heptane. Ce catalyseur NiMo/EMT-Si s'avère plus actif en hydrogénation que son analogue NiMo/HY, en raison d'une meilleure dispersion du sulfure de NiMo. Sur le solide EMT modifié, le sulfure se répartit à peu près également entre les mésopores internes et les fissures crées dans les grains de zéolithe lors de l'insertion du sulfure de NiMo. Au contraire sur le support Y, une partie du sulfure est externe aux grains de zéolithe et inactive en catalyse. Le catalyseur NiMo/EMT-Si est aussi trouvé plus actif que le NiMo/HY en hydrocraquage du n-heptane, et un peu plus sélectif en isomères.

  6. Électrooxydation du mésoérythritol sur platine, modifié ou non par des adatomes, en milieu acide

    NASA Astrophysics Data System (ADS)

    Cherqaoui, A.; Chbihi, M. El M.; Takky, D.; Kokoh, K. B.; Leger, J.-M.; Lamy, C.

    1999-03-01

    The electrocatalytic oxidation of meso-erythritol has been studied in 0.1 M HClO4 on platinum and on adatoms modified platinum. Preliminary investigations by cyclic voltammetry showed that erythritol was not reactive on a Pt electrode. Underpotential deposition of lead or thallium adatoms at platinum allowed to increase significantly the current densities. Long-time electrolyses were carried out using a three potential plateau program with different values of the oxidation potentials. Chromatographic analyses showed that the oxidation of erythritol led mainly to erythrose, erythrulose and to erythronic acid. Otherwise, electrolysis of erythritol on a Pt-Tl modified electrode orientated selectively the distribution of the reaction products towards the formation of erythrulose. L'oxydation électrocatalytique du mésoérythrytol a été étudiée en milieu acide HClO4 0,1 M sur le platine modifié ou non par des adatomes métalliques. Les études préliminaires réalisées par voltammétrie cyclique montrent que l'érythritol est très peu réactif sur le platine seul. La modification de la surface de l'électrode par dépôt en sous-tension d'adatomes de plomb et de thallium permet d'augmenter les densités de courant. Les électrolyses prolongées sont réalisées à l'aide d'un programme à trois paliers de potentiel et pour différentes valeurs de potentiel d'oxydation. Les analyses chromatographiques montrent que les produits d'oxydation sont l'érythrose, l'érythrulose et l'acide érythronique. D'autre part l'oxydation de l'érythritol sur le platine modifié par des adatomes de thallium conduit à une production sélective d'érythrulose.

  7. Effet de la concentration du cuivre ou de l'argent sur les propriétés des agrégats de rhodium déposés sur silice amorphe dans l'hydrogénation du 1,3 butadiène

    NASA Astrophysics Data System (ADS)

    Ksibi, Z.; Ghorbel1, A.; Bellamy, B.

    1999-02-01

    Some samples with rhodium, rhodium-copper and rhodium-silver deposited on amorphous silica by vapor deposition of the metallic phase under high-vacuum (P < 5.10-7 Pa) have been prepared. The effect of rhodium cluster size and copper or silver addition on catalytic properties of rhodium in the 1,3 butadiène hydrogenation was studied. Results show that the reaction is sensitive to the size of rhodium aggregates and that there is an important difference between the effect of copper and silver on the rhodium properties. Indeed copper forms an alloy with rhodium and provokes a poison effect on the activity of the noble metal, whereas silver exhibits a mask effect on the rhodium particles without forming alloy with it. Des échantillons mono-métalliques au rhodium et bimétalliques rhodium-cuivre et rhodium-argent déposés sur une silice amorphe par vapodéposition d'une phase métallique dans des conditions ultra-vide (P < 5.10-7 Pa) ont été préparés. L'effet de la taille des agrégats de rhodium ainsi que celui de l'addition du cuivre ou de l'argent sur les propriétés catalytiques du rhodium dans l'hydrogénation du 1,3 butadiène ont été étudiés. Les résultats montrent que la réaction étudiée est sensible à la taille des agrégats de rhodium et nous notons une différence importante entre l'effet du cuivre et de l'argent sur les propriétés du rhodium. En effet le cuivre forme un alliage avec le rhodium et provoque un effet poison d?où une modification de l'activité du métal noble, alors que l'argent exerce un effet de masque sur les particules de rhodium sans toutefois former d'alliage avec ce dernier.

  8. Gold pickings and PIXE analysis. More about the Bronze age gold found in the cave of Han-sur-Lesse (Namur, Belgium)

    NASA Astrophysics Data System (ADS)

    Warmenbol, Eugène

    2004-11-01

    Gold remains a rare material during the whole Bronze Age. It is a metal that circulates amongst the elites exclusively. The exchange of gold artefacts over very long distances is fundamental in the build-up of socio-political relations. Fifty artefacts found during subaquatic excavations in the river Lesse in the cave of Han-sur-Lesse have been submitted to quantitative elemental analysis using PIXE, a method never used before on archaeological material found in Belgium. The results show that there are clearly three groups of artefacts. The first one (discs, "baskets", pearls) proves of local manufacture, as also suggested by the discovery of two ingots. The second one (gilded rings) could have been locally made too, but is a lot less homogeneous. The third one (filigreed and granulated beads or pin's heads) must be imported and most probably originates in the Mediterranean.

  9. Étude de la condensation par convection forcée du R113, R152a et du R12 sur une plaque plane horizontale

    NASA Astrophysics Data System (ADS)

    Louahlia, H.; Panday, P. K.

    1996-07-01

    Forced convection condensation of pure vapour flowing between two horizontal parallel plates with the bottom plate cooled is analysed numerically. The coupled boundary layer equations for the two phases are solved using an implicite finite difference procedure. The pressure gradient, shear stress, inertia and enthalpy convection terms, and turbulence in the two phases are retained in this analysis. The laminar model and the turbulent models of Pletcher [19] and Koyama et al. [20] are compared for condensation of R113. The mean heat transfer coefficients predicted with the model of Pletcher [19] are in good agreement with the experimental results of Lu and Suryanarayana [18]. The thermal performances of R152a and R12 are also compared. For the condensation of R152a, the pressure drop is 18% smaller and the mean heat transfer coefficients are 24% higher compared to those of R12. These results are in line with the experimental work of Cheng and Tao [12]. The influence of the temperature difference and inclination of the plate on the condensate film thikness are also reported. The results of the present calculations for the condensation of R12, R152a and R113 are represented by a non-dimensional equation. La condensation en film par convection forcée est analysé numériquement pour un écoulement de vapeur pure saturée entre deux plaques planes horizontales. Le condensat se forme uniquement sur une plaque inférieure. Les équations de la couche limite appliquées dans les deux phases sont couplées et résolues par une méthode des différences finies implicite. Le gradient de pression, les contraintes tangentielles, les termes d'inertie et de convection d'enthalpie ainsi que la turbulence dans les deux phases sont pris en compte. Le modèle laminaire ainsi que les modèles de turbulence de Pletcher [19] et de Koyama et al. [20] sont comparés pour la condensation du R113. Les coefficients d'échange thermique moyens prédits avec le modèle de Pletcher, s

  10. Variation du coefficient de collage de l'argent et de l'or durant leur condensation sur film de MgO

    NASA Astrophysics Data System (ADS)

    Desrousseaux, G.; Carlan, A.; Jiang, Z.

    1993-10-01

    The incidence rate dependence of the sticking coefficient during the growth of gold (or silver) condensate on MgO film is experimentally investigated for a substrate kept at room temperature. This MgO substrate is deposited on quartz monitor by evaporation under UHV from a Knudsen cell. Then, from another cell, the flux of metal atoms impinges on the MgO film which covers the quartz. Under this flux of incident metal atoms, the changes (respectively θ and f) of the temperature and of the frequency of the quartz oscillator are then simultaneously recorded. Both continuous measurements enable us to calculate, at different times t, the sticking coefficient η (t) defined as the ration between the condensed metal rate q and the incident rate R. We use the results to plot η versus t and examine the slope of η-rise until the time t at which η (t) reaches unity. The progression of η (t) reaches unity. The progression of η (t) from zero to unity during the metal deposition is explained by assuming that the nucleation on preferred sites with capture of adatoms at the edge of stable germs is the prevailing condensation mechanism at the initial stage of the condensation. Our experimental results could be fitted better by assuming an exponential growth of the site occupation than an increase of the number density n_s(t) with (Rt)^{1/3}. On étudie expérimentalement la dépendance que peut présenter, par rapport au flux métallique incident, la progression vers l'unité du coefficient de collage. Pour cela, on suit cette progression pour l'or et l'argent condensés sur film de MgO à température proche de l'ambiante. Le substrat de MgO est déposé sur un quartz de pesée par évaporation sous ultra-vide à partir d'une cellule de Knudsen. Une autre cellule est utilsée pour déposer l'un de ces métaux sur le film de MgO couvrant le quartz. Les variations θ et f de la température et de la fréquence d'oscillations du quartz de pesée sous le flux d'atomes incidents

  11. Two new hemoglobin variants: Hb Brem-sur-Mer [beta9(A6)Ser-->Tyr] and Hb Passy [alpha81(F2)Ser-->Pro (alpha2)].

    PubMed

    Lacan, Philippe; Moreau, Mathieu; Becchi, Michel; Zanella-Cleon, Isabelle; Aubry, Martine; Louis, Jean-Jacques; Couprie, Nicole; Francina, Alain

    2005-01-01

    Two new hemoglobin (Hb) variants: Hb Brem-sur-Mer [codon 9 (TCT-->TAT); beta9(A6)Ser-->Tyr] on the first exon of the beta-globin gene and Hb Passy [codon 81 (TCC-->CCC); alpha81(F2)Ser-->Pro (alpha2)] on the second exon of the alpha2-globin gene, are described. The two variants were characterized by DNA sequencing and mass spectrometry (MS). Hematological abnormalities: microcytosis and hypochromia were found only in the carrier of Hb Passy. In the absence of an association with an alpha-thalassemic deletion or mutation, the mutation 81(F2)Pro could induce a possible alpha-thalassemia (thal).

  12. Perspective sur les ruptures d’approvisionnement de médicaments en établissement de santé de 2006 à 2010

    PubMed Central

    Bussières, Jean-François; Chiveri, Andrei; Lebel, Denis

    2011-01-01

    RÉSUMÉ Contexte: Si les ruptures d’approvisionnement de médicaments font partie de la réalité de la pratique pharmaceutique depuis plusieurs décennies, elles deviennent une préoccupation quotidienne pour les pharmaciens dans les années 2000 et dépassent les frontières de la littérature pharmaceutique. Objectif: L’objectif principal de cette étude était de quantifier le nombre de médicaments en rupture de stock par année et la durée de ces interruptions. L’objectif secondaire visait à décrire le nombre de médicaments en rupture de stock par fabricant et par classe thérapeutique. Méthode: Cette étude descriptive et rétrospective des ruptures d’approvisionnement en médicaments a porté sur l’ensemble des médicaments à contrat pour les hôpitaux des régions administratives de Montréal, de Laval et de l’Estrie, au Québec. Le nombre de ruptures de stocks, le nombre de jours de rupture de stock et leur durée moyenne par année ont été calculés par fabricant et par classe thérapeutique. De plus, la proportion de produits en rupture de stock et la proportion de jours de rupture de stocks ont été déterminées par classe thérapeutique. Les données ont été analysées à l’aide de statistiques descriptives (c.-à-d. somme, moyenne, écart-type, médiane, intervalle). Résultats: Entre le 1er janvier 2006 et le 31 août 2010 (une période de 56 mois), 2400 ruptures de stocks ont été dénombrées pour un total de 258 105 jours de rupture de stocks (durée moyenne de 108 jours, écart-type de 130 jours et intervalle de 5 à 1623 jours). Un total de 70 fabricants étaient impliqués dans la survenue de toutes les ruptures d’approvisionnement de médicaments relevées durant cette période. Cinquante pour cent (50 %) des ruptures de stocks et des jours de rupture de stocks provenaient de quatre fabricants. Les interruptions étudiées touchaient la majorité des classes thérapeutiques de médicaments disponibles sur le

  13. Embedded Gaussian unitary ensembles with U(Ω)⊗SU(r) embedding generated by random two-body interactions with SU(r) symmetry

    NASA Astrophysics Data System (ADS)

    Vyas, Manan; Kota, V. K. B.

    2012-12-01

    Following the earlier studies on embedded unitary ensembles generated by random two-body interactions [EGUE(2)] with spin SU(2) and spin-isospin SU(4) symmetries, developed is a general formulation, for deriving lower order moments of the one- and two-point correlation functions in eigenvalues, that is valid for any EGUE(2) and BEGUE(2) ("B" stands for bosons) with U(Ω)⊗SU(r) embedding and with two-body interactions preserving SU(r) symmetry. Using this formulation with r = 1, we recover the results derived by Asaga et al. [Ann. Phys. (N.Y.) 297, 344 (2002)], 10.1006/aphy.2002.6248 for spinless boson systems. Going further, new results are obtained for r = 2 (this corresponds to two species boson systems) and r = 3 (this corresponds to spin 1 boson systems).

  14. Effet de la dose d'irradiation sur la fraction tocophérolique d'huiles végétales

    NASA Astrophysics Data System (ADS)

    Chaouch, A.; El Fartah, S.; Pouliquen-Sonaglia, I.; Lesgards, G.; Raffi, J.; Trihi, M.

    1999-01-01

    Tocopherols, minor components of vegetable oils, are very important due to their high antioxydant power; we studied separation and quantification of tocopherol fraction with regard to the irradiation dose, using liquid chromatography combined with electrochemical detection. Dans les huiles végétales, les tocophérols sont des constituants mineurs très importants grâce à leur pouvoir antioxydant très élevé. Notre travail s'est porté sur la séparation et la quantification de la fraction tocophérolique et son évolution en fonction des différentes doses d'ionisation par la technique C.L.H.P. / détection électrochimique.

  15. [Length, body weight and sex of the golden Coryphaena hippurus (Perciformes: Coryphaenidae), of the littoral of Sinaloa, Nayarit and Baja California Sur, Mexico].

    PubMed

    Madrid, J V; Beltrán-Pimienta, R

    2001-01-01

    Dolphin fish population data were recorded from landings in Sinaloa, Nayarit and Baja Califonia Sur, Mexico, in 1997. Of 3,211 organisms, only 2,812 produced complete biometric data. The maximal length and weight were 192 cm and 30 kg. The three sampling sites and the climatic periods also were associated with different size (P < 0.05). The covariate analysis of weight and length relationships indicated significative differences (P < 0.05) for total data and by sex. Condition factor was higher throughout the study period in Mazatlán, and the variation was higher, in the spring. The sexual ratio was in Mazatlán constant, while there were more males in Nayarit in the fall and the spring and in Los Cabos in the spring. There may be population differences, between the central mexican Pacific Coast and the Peninsula of Baja data. PMID:12189824

  16. [Length, body weight and sex of the golden Coryphaena hippurus (Perciformes: Coryphaenidae), of the littoral of Sinaloa, Nayarit and Baja California Sur, Mexico].

    PubMed

    Madrid, J V; Beltrán-Pimienta, R

    2001-01-01

    Dolphin fish population data were recorded from landings in Sinaloa, Nayarit and Baja Califonia Sur, Mexico, in 1997. Of 3,211 organisms, only 2,812 produced complete biometric data. The maximal length and weight were 192 cm and 30 kg. The three sampling sites and the climatic periods also were associated with different size (P < 0.05). The covariate analysis of weight and length relationships indicated significative differences (P < 0.05) for total data and by sex. Condition factor was higher throughout the study period in Mazatlán, and the variation was higher, in the spring. The sexual ratio was in Mazatlán constant, while there were more males in Nayarit in the fall and the spring and in Los Cabos in the spring. There may be population differences, between the central mexican Pacific Coast and the Peninsula of Baja data.

  17. Maps showing estimated sediment yield from coastal landslides and active slope distribution along the Big Sur coast, Monterey and San Luis Obispo Counties, California

    USGS Publications Warehouse

    Hapke, Cheryl J.; Green, Krystal R.; Dallas, Kate

    2004-01-01

    The 1982-83 and 1997-98 El Ni?os brought very high precipitation to California?s central coast; this precipitation resulted in raised groundwater levels, coastal flooding, and destabilized slopes throughout the region. Large landslides in the coastal mountains of Big Sur in Monterey and San Luis Obispo Counties blocked sections of California State Route 1, closing the road for months at a time. Large landslides such as these occur frequently in the winter months along the Big Sur coast due to the steep topography and weak bedrock. A large landslide in 1983 resulted in the closure of Highway 1 for over a year to repair the road and stabilize the slope. Resulting work from the 1983 landslide cost over $7 million and generated 30 million cubic yards of debris from landslide removal and excavations to re-establish the highway along the Big Sur coast. Before establishment of the Monterey Bay National Marine Sanctuary (MBNMS) in 1992, typical road opening measures involved disposal of some landslide material and excess material generated from slope stabilization onto the seaward side of the highway. It is likely that some or most of this disposed material, either directly or indirectly through subsequent erosion, was eventually transported downslope into the ocean. In addition to the landslides that initiate above the road, natural slope failures sometimes occur on the steep slopes below the road and thus deliver material to the base of the coastal mountains where it is eroded and dispersed by waves and nearshore currents. Any coastal-slope landslide, generated through natural or anthropogenic processes, can result in sediment entering the nearshore zone. The waters offshore of the Big Sur coast are part of the MBNMS. Since it was established in 1992, landslide-disposal practices came under question for two reasons. The U.S. Code of Federal Regulations, Title 15, Section 922.132 prohibits discharging or depositing, from beyond the boundary of the Sanctuary, any material

  18. Benthic trophic network in the Bay of Banyuls-sur-Mer (northwest Mediterranean, France): An assessment based on stable carbon and nitrogen isotopes analysis

    NASA Astrophysics Data System (ADS)

    Carlier, Antoine; Riera, Pascal; Amouroux, Jean-Michel; Bodiou, Jean-Yves; Grémare, Antoine

    2007-03-01

    The benthic trophic network in the Bay of Banyuls-sur-Mer was studied through the carbon and nitrogen isotopic characterization of a large set of soft-bottom macrobenthic invertebrates, fishes and potential food sources. Continental inputs as well as seagrass meadows did not contribute significantly to this benthic trophic network as indicated by: (1) the difference between their δ 13C signatures (respectively -28.4‰ and -9.5‰) and those of sampled animals (between -21.0‰ and -14.6‰); and (2) their low inputs to the bay. Benthic primary consumers fed mostly on surface sediment organic matter (SSOM), which tightly interacts with suspended particulate organic matter (SPOM) and sedimenting organic matter (STOM) due to sediment resuspension. Our results also suggest the occurrence of a transfer between marine SPOM and some invertebrates (e.g. Veretillum cynomorium) and fishes (e.g. Boops boops and Spicara melanurus) through zooplankton. Moreover, the different types of primary consumers (i.e., suspension-feeders, interface-feeders, surface deposit-feeders and subsurface deposit-feeders) preferentially used distinct fractions of the heterogeneous SPOM-STOM-SSOM pool. These differences were mostly related with feeding depth and resulted in distinct isotopic signatures. Differences in the stable isotopic ratios of suspension and interface-feeders could also partly reflect the use of microphytobenthos by the later. Assuming a 15N-enrichment factor of 3.4‰ between the lower and upper ranges of two successive trophic levels, we estimated that the benthic food web of the Bay of Banyuls-sur-Mer was composed of 4 trophic levels. The comparison with our δ 13C values suggests that the whole trophic food chain is affected by continental inputs at the immediate vicinity of the Rhône River mouth even though these effects are maximal for deposit-feeding and carnivorous polychaetes.

  19. Pharmacology of human sulphonylurea receptor SUR1 and inward rectifier K+ channel Kir6.2 combination expressed in HEK-293 cells

    PubMed Central

    Gopalakrishnan, Murali; Molinari, Eduardo J; Shieh, Char-Chang; Monteggia, Lisa M; Roch, Jean-Marc; Whiteaker, Kristi L; Scott, Victoria E S; Sullivan, James P; Brioni, Jorge D

    2000-01-01

    The pharmacological properties of KATP channels generated by stable co-expression of the sulphonylurea receptor SUR1 and the inwardly rectifying K+ channel Kir6.2 were characterized in HEK-293 cells.[3H]-Glyburide (glibenclamide) bound to transfected cells with a Bmax value of 18.5 pmol mg−1 protein and with a KD value of 0.7 nM. Specific binding was displaced by a series of sulphonylurea analogues with rank order potencies consistent with those observed in pancreatic RINm5F insulinoma and in the brain.Functional activity of KATP channels was assessed by whole cell patch clamp, cation efflux and membrane potential measurements. Whole cell currents were detected in transfected cells upon depletion of internal ATP or by exposure to 500 μM diazoxide. The currents showed weak inward rectification and were sensitive to inhibition by glyburide (IC50=0.92 nM).Metabolic inhibition by 2-deoxyglucose and oligomycin treatment triggered 86Rb+ efflux from transfected cells that was sensitive to inhibition by glyburide (IC50=3.6 nM).Diazoxide, but not levcromakalim, evoked concentration-dependent decreases in DiBAC4(3) fluorescence responses with an EC50 value of 14.1 μM which were attenuated by the addition of glyburide. Diazoxide-evoked responses were inhibited by various sulphonylurea analogues with rank order potencies that correlated well with their binding affinities.In summary, results from ligand binding and functional assays demonstrate that the pharmacological properties of SUR1 and Kir6.2 channels co-expressed in HEK-293 cells resemble those typical of native KATP channels described in pancreatic and neuronal tissues. PMID:10742287

  20. Sur la nature de la variabilite spectrale et photometrique periodique d'etoiles Wolf-Rayet apparemment isolees

    NASA Astrophysics Data System (ADS)

    Morel, Thierry

    Il est depuis longtemps suspecté que les étoiles Wolf-Rayet apparemment isolées présentant des variations périodiques dans le profil de leurs raies spectrales, en photométrie ou en polarimétrie sont associées à un compagnon dégénéré (étoile à neutron ou trou noir), et constituent ainsi une phase évolutive dont l'existence, bien que prédite par les modèles évolutifs des systèmes binaires massifs rapprochés, n'a pas encore été catégoriquement confirmée observationnellement. Cependant, de récentes études ayant trait à la variabilité spectrale des étoiles OB laissent émettre quelques doutes quant à la pertinence de ce modèle, en démontrant que des vents largement asphériques peuvent se développer dans les étoiles de type précoce. Le scénario alternatif serait donc de considérer que la variabilité périodique observée n'est pas due à la présence d'un compagnon dégénéré affectant la structure à grande échelle du vent de l'étoile Wolf-Rayet, mais est au contraire induite par la modulation par rotation d'un vent nettement anisotropique. Cet ouvrage présente les résultats d'un vaste programme d'observations spectroscopiques et photométriques (généralement simultanées) se proposant de lever l'ambiguïté sur la nature précise des étoiles Wolf-Rayet apparemment isolées dont la périodicité des variations est. soit depuis longtemps établie (WR 6), soit suspectée (WR 1, WR 134, WR 136). Notre étude a permis de confirmer l'existence d'une périodicité de 2.3 jours pour l'étoile WR 134. En outre, nous présentons des arguments mettant en doute l'éventuelle association de WR 6 et WR 134 avec un compagnon dégénéré. Alternativement, nous proposons que la variabilité périodique observée serait plutôt induite, à l'instar de nombreuses étoiles OB, par la rotation de structures azimutalement étendues dans le vent. Ce modèle est plus à même d'appréhender certains aspects de la variabilité, notamment la

  1. Lignes directrices canadiennes sur l’utilisation sécuritaire et efficace des opioïdes pour la douleur chronique non cancéreuse

    PubMed Central

    Kahan, Meldon; Wilson, Lynn; Mailis-Gagnon, Angela; Srivastava, Anita

    2011-01-01

    Résumé Objectif Présenter aux médecins de famille un résumé clinique pratique sur la prescription d’opioïdes à des populations particulières en se fondant sur les recommandations faites dans les lignes directrices canadiennes sur l’utilisation sécuritaire et efficace des opioïdes pour la douleur chronique non cancéreuse. Qualité des données Pour produire les lignes directrices, les chercheurs ont effectué une synthèse critique de la littérature médicale en insistant plus précisément sur les études de l’efficacité et de la sécurité des opioïdes dans des populations particulières. Message principal Les médecins de famille peuvent atténuer les risques de surdose, de sédation, d’usage abusif et de dépendance grâce à des stratégies adaptées à l’âge et à l’état de santé des patients. Dans le cas de patients à risque de dépendance, on devrait réserver les opioïdes aux douleurs nociceptives ou neuropathiques bien définies qui n’ont pas répondu aux traitements de première intention. Il faut procéder lentement au titrage des opioïdes, avec des dispensations fréquentes et une étroite surveillance pour dépister tout signe d’usage abusif. Une dépendance aux opioïdes suspectée est prise en charge au moyen d’une thérapie structurée aux opioïdes, d’un traitement à la méthadone ou à la buprénorphine ou encore d’un traitement fondé sur l’abstinence. Les patients souffrant de troubles de l’humeur ou d’anxiété ont tendance à avoir une réponse analgésique atténuée aux opioïdes, sont à risque plus élevé d’usage abusif et prennent souvent des sédatifs qui interagissent défavorablement avec les opioïdes. Il faut prendre des précautions semblables à celles utilisées avec d’autres patients à risque élevé. Il faut faire un sevrage progressif si la douleur du patient demeure sévère même avec un essai adéquat de thérapie aux opioïdes. Chez les personnes âgées, la s

  2. Lignes directrices canadiennes sur l’utilisation sécuritaire et efficace des opioïdes pour la douleur chronique non cancéreuse

    PubMed Central

    Kahan, Meldon; Mailis-Gagnon, Angela; Wilson, Lynn; Srivastava, Anita

    2011-01-01

    Résumé Objectif Présenter aux médecins de famille un résumé clinique pratique des lignes directrices canadiennes sur l’utilisation sécuritaire et efficace des opioïdes pour la douleur chronique non cancéreuse, produites par le National Opioid Use Guideline Group. Qualité des données Pour produire les lignes directrices, les chercheurs ont effectué une synthèse critique de la littérature médicale sur l’efficacité et l’innocuité des opioïdes pour la douleur chronique non cancéreuse et ont rédigé une série de recommandations. Un panel de 49 cliniciens experts de toutes les régions du Canada ont passé en revue l’ébauche et ont atteint un consensus sur 24 recommandations. Message principal Il est recommandé de faire un dépistage du risque de dépendance avant de prescrire des opioïdes. On recommande des opioïdes faibles (codéine et tramadol) pour une douleur de légère à modérée qui n’a pas répondu aux traitements de première intention. On peut essayer l’oxycodone, l’hydromorphone et la morphine chez les patients qui n’ont pas eu de soulagement avec des opioïdes plus faibles. Une faible dose initiale et une lente hausse du titrage sont recommandées, ainsi qu’une étroite surveillance du patient qu’on a d’abord renseigné. Les médecins doivent surveiller l’apparition de complications comme l’apnée du sommeil. La dose optimale est celle qui améliore le fonctionnement ou atténue les cotes d’évaluation de la douleur d’au moins 30 %. Pour la grande majorité des patients, la dose optimale sera bien en deçà de l’équivalent de 200 mg de morphine par jour. On recommande le sevrage progressif pour les patients qui n’ont pas répondu à un essai d’opioïdes adéquat. Conclusion Les opioïdes jouent un rôle important dans la prise en charge de la douleur chronique non cancéreuse, mais il faut en prescrire avec prudence pour limiter les dommages potentiels. Les nouvelles lignes directrices

  3. Transport de particules massives dans un fluide turbulent: Application a l'erosion due au sable sur les parois d'une turbine hydraulique

    NASA Astrophysics Data System (ADS)

    Bergeron, Stephen

    Le transport de particules massives par un champ turbulent est un vaste domaine de la mécanique des fluides. Il possède de nombreuses applications comme par exemple le transport de sable dans une turbine hydraulique. En raison de la dureté des grains de quartz et des grandes vitesses de collision avec les parois métalliques, un phénomène d'érosion intensif se produit. Les dommages résultants peuvent diminuer le rendement de la turbine au cours des quelques mois suivant la mise en opération. L'objectif de cette thèse est de mettre au point un outil permettant de prédire ces zones d'érosion. Ce projet de recherche en contexte industriel a été réalisé en collaboration avec la compagnie General Electric Hydro du Canada. Dans un régime hautement turbulent, il est possible d'obtenir une expression suffisamment générale en utilisant une formulation partiellement empirique: l'équation de Basset- Boussinesq-Oseen modifiée. Ce choix de modèle tient compte du niveau de précision recherché et de la méthode numérique employée afin de résoudre la phase fluide. Il permet aussi d'éliminer plusieurs ambiguïtés fréquemment rencontrées dans la littérature et implementées dans certains codes commerciaux courants. La formulation mathématique du problème est effectuée dans un espace mixte Euler-Lagrange. Les paramètres dynamiques sont relies au type de particules et à l'intensité de la turbulence. Le code numérique résultant est le plus performant développé à ce jour (août 1998). Les trajectoires de plusieurs centaines de milliers de particules peuvent être simulées et visualisées de manière interactive sur une station de travail (SGI R4K, R8K et R10K). L'utilisateur du logiciel est libre de se déplacer dans l'espace à l'aide d'un environnement similaire a un ``simulateur de vol''. Il peut ainsi analyser les détails du processus d'érosion de même que l'écoulement du fluide dans la turbine. Les zones d'érosion obtenues à l

  4. Quatrième conférence consensuelle sur le diagnostic et le traitement de la démence

    PubMed Central

    Moore, Ainsley; Patterson, Christopher; Lee, Linda; Vedel, Isabelle; Bergman, Howard

    2014-01-01

    Résumé Objectif Revoir les stratégies diagnostiques de la maladie d’Alzheimer, actualiser les recommandations concernant le traitement des symptômes de démence et proposer une approche thérapeutique à la démence d’apparition précoce et d’évolution rapide. Composition du comité Des spécialistes et des délégués de diverses régions du Canada et représentant diverses disciplines pertinentes ont discuté et se sont mis d’accord sur les révisions à apporter aux lignes directrices de 2006. Méthodologie On a eu recours au système GRADE (grading of recommendations, assessment, development, and evaluation) pour évaluer le consensus concernant les recommandations, lequel était défini comme suit : lorsque 80 % ou plus des participants ont voté en faveur de la recommandation. La cote des données probantes est rapportée lorsque cela est possible. Rapport important pour les médecins de famille, malgré les progrès effectués dans les domaines des biomarqueurs liquidiens et de la neuro-imagerie, le diagnostic de démence au Canada demeure fondamentalement clinique. De nouveaux critères cliniques essentiels de diagnostic de la maladie d’Alzheimer en reconnaissent dorénavant les formes moins fréquentes et non amnestiques. La démence précoce, une affection rare, mais importante, devrait inciter les médecins à aiguiller les patients vers un spécialiste ayant accès à des conseillers en génétique. La démence d’évolution rapide, mal définie dans la littérature, faciliterait le dépistage de cette affection rare, mais importante. Les inhibiteurs de la cholinestérase sont maintenant indiqués pour le traitement d’affections autres que la maladie d’Alzheimer. Des lignes directrices concernant l’arrêt du traitement, lesquelles n’existaient pas auparavant, sont également apparues. De nouvelles données probantes sur le recours à la mémantine, aux antidépresseurs et à d’autres agents psychotropes dans le traitement de la

  5. Si vous pensez que c'est juste un mal de jambe… détrompez-vous: ce que les leaders en santé doivent savoir sur la maladie artérielle périphérique.

    PubMed

    Papia, Giuseppe; Mayer, Perry; Kelton, David; Queen, Douglas; Elliott, James A; Kuhnke, Janet L

    2015-11-01

    Environ 800 000 Canadiens ont une maladie artérielle périphérique (MAP), une cause majeure d'amputation. Pourtant, le public et les cliniciens connaissent très peu cette maladie. Le présent article traite de la campagne de sensibilisation Si vous pensez que c'est juste un mal de jambe… détrompez-vous que l'Association canadienne du soin des plaies a lancée pour contrer cette tendance. Il porte également sur les facteurs de risque et le dépistage de la MAP, son lien avec le diabète, son traitement et ses soins, ses innovations en matière de soins de la MAP et la nécessité de faire preuve de leadership sur le plan des politiques. PMID:26487733

  6. Structure and geomorphology of the "big bend" in the Hosgri-San Gregorio fault system, offshore of Big Sur, central California

    NASA Astrophysics Data System (ADS)

    Johnson, S. Y.; Watt, J. T.; Hartwell, S. R.; Kluesner, J. W.; Dartnell, P.

    2015-12-01

    The right-lateral Hosgri-San Gregorio fault system extends mainly offshore for about 400 km along the central California coast and is a major structure in the distributed transform margin of western North America. We recently mapped a poorly known 64-km-long section of the Hosgri fault offshore Big Sur between Ragged Point and Pfieffer Point using high-resolution bathymetry, tightly spaced single-channel seismic-reflection and coincident marine magnetic profiles, and reprocessed industry multichannel seismic-reflection data. Regionally, this part of the Hosgri-San Gregorio fault system has a markedly more westerly trend (by 10° to 15°) than parts farther north and south, and thus represents a transpressional "big bend." Through this "big bend," the fault zone is never more than 6 km from the shoreline and is a primary control on the dramatic coastal geomorphology that includes high coastal cliffs, a narrow (2- to 8-km-wide) continental shelf, a sharp shelfbreak, and a steep (as much as 17°) continental slope incised by submarine canyons and gullies. Depth-converted industry seismic data suggest that the Hosgri fault dips steeply to the northeast and forms the eastern boundary of the asymmetric (deeper to the east) Sur Basin. Structural relief on Franciscan basement across the Hosgri fault is about 2.8 km. Locally, we recognize five discrete "sections" of the Hosgri fault based on fault trend, shallow structure (e.g., disruption of young sediments), seafloor geomorphology, and coincidence with high-amplitude magnetic anomalies sourced by ultramafic rocks in the Franciscan Complex. From south to north, section lengths and trends are as follows: (1) 17 km, 312°; (2) 10 km, 322°; (3)13 km, 317°; (4) 3 km, 329°; (5) 21 km, 318°. Through these sections, the Hosgri surface trace includes several right steps that vary from a few hundred meters to about 1 km wide, none wide enough to provide a barrier to continuous earthquake rupture.

  7. Décohésion d'interfaces dans des couches de NiO sur du nickel industriel de pureté variable

    NASA Astrophysics Data System (ADS)

    Chirat, B.; Haut, C.; Huntz, A. M.; Andrieux, M.; Feltz, B.

    2003-03-01

    L'oxydation sous air de deux nickel de pureté industrielle mais de provenance différente a été étudiée, principalement à 800^{circ}C. Outre la cinétique d'oxydation et la morphologie des couches de NiO, l'étude a été focalisée sur les caractéristiques mécaniques des couches de NiO. Celles-ci ont été caractérisées à la température ambiante, essentiellement par flexion trois points sous MEB. Si la cinétique d'oxydation des deux métaux industriels est voisine et associée à des morphologies de couches assez complexes mais similaires, il n'en est pas de même pour la majorité des caractéristiques mécaniques. Ainsi, même en prenant en compte l'évolution des caractéristiques mécaniques du nickel avec le temps de traitement, on observe des différences dans les valeurs de KIC des couches de NiO selon la nature du substrat et l'épaisseur de la couche d'oxyde, c'est-à-dire avec la durée de l'oxydation. Enfin et surtout, le comportement vis-à-vis de la décohésion est très différent : il est pratiquement impossible d'écailler les couches de NiO formées sur l'un des nickel, tandis que la décohésion est obtenue avec une relative facilité dans le cas de l'autre nickel. Mais, cette décohésion n'a pas lieu à l'interface métal-oxyde, mais à l'interface oxyde-oxyde, en raison de la formation de deux couches de NiO, l'une interne, l'autre externe.

  8. Une étude rétrospective sur le cancer de l'ovaire avec un recul médian de 42 mois

    PubMed Central

    Raherinantenaina, Fanomezantsoa; Rakotomena, Solonirina Davidà; Hasiniatsy, Nomeharisoa Rodrigue Emile; Rakototiana, Felantsoa Auberlin; Rafaramino, Florine; Ratsimba, Hery Nirina Rakoto

    2015-01-01

    Le cancer de l'ovaire est relativement fréquent mais grave et de mauvais pronostic. Le but de cette étude était de mettre en évidence les aspects épidémiologique, diagnostique, thérapeutique et évolutif de cette pathologie maligne prise en charge dans un pays en développement. Il s'agit d'une étude rétrospective et descriptive de 10 ans (2000- 2009) effectuée dans un CHU de chirurgie générale et d'Oncologie sur 62 patientes ayant développé un cancer de l'ovaire et opérées à visée curative. L’âge moyen des patientes était de 43 ans dont 53,23% avaient plus de 45 ans. Le dosage sanguin du CA-125 était positif chez 10 patientes sur 12. Les tumeurs étaient découvertes à l’échographie dans 87,10% des cas et à la laparotomie dans 12,90%. L'hystérectomie totale avec annexectomie bilatérale était l'intervention la plus pratiquée (64,52%). Les suites opératoires précoces étaient simples. Dix patientes étaient opérées de second regard (16,13%) pour des récidives locorégionales. Les tumeurs épithéliales étaient le type histologique le plus fréquent (93,55%) dont 79% au stade avancé (Ic-IV) et 21% au stade précoce (Ia-Ib). La chimiothérapie adjuvante était administrée chez 22,60% des patientes. Avec un recul médian de 42 mois, 29 patientes étaient perdues de vue. L’évolution était favorable dans 27,42% et dans 25,81% les décès se sont survenus en postopératoire tardif. Le cancer de l'ovaire n’était pas fréquent mais grave compte tenu des stades avancés et du taux élevé des décès postopératoires tardifs qui étaient largement observés chez les patientes privées d'une chimiothérapie adéquate. PMID:26113942

  9. Carbonate chemistry and air-sea CO2 flux at a fixed point in a NW Mediterranean Bay, Villefranche-sur-Mer, France

    NASA Astrophysics Data System (ADS)

    De Carlo, E. H.; Mousseau, L.; Passafiume, O.; Drupp, P. S.; Gattuso, J.

    2011-12-01

    The purpose of the Service d'Observation de la Rade de Villefranche-sur-Mer (SO-RADE) is to study the temporal variability of hydrological conditions as well as the abundance and composition of holo- and meroplankton at a fixed station in the bay of Villefranche-sur-Mer, North West Mediterranean. The weekly data collected at this site, designated as "Point B (43° 41.10'N - 7° 18.94'E), since 1957 are recognized as a long-term time series describing the evolution of the hydrological conditions in a coastal environment. Since 2007, historical measurements of hydrological and biological conditions have been complemented by measurements of the CO2-carbonate system parameters. In this contribution we present CO2-carbonate system parameters and ancillary data for the period 2007-2010. The data are evaluated in the context of the physical and biogeochemical processes that contribute to the fluxes of CO2 between the ocean and atmosphere. Seasonal cycles of seawater pCO2 are controlled principally by variations in temperature, showing maxima in the summer and minima during the winters. Normalization of pCO2 to the mean seawater temperature (18oC) results in an apparent reversal of the seasonal cycle with maxima observed in the winters and minima in the summers, consistent with a control of pCO2 by primary productivity. Calculations of "instantaneous fluxes" of CO2 between the ocean and atmosphere show this area to be primarily a weak source of CO2 to the atmosphere during the summer and a weak sink during the winter and near neutral overall (range: -0.3 to +0.3 mmol CO2 m-2 h-1, average: 0.02 mmol CO2 m-2 h-1). We will also provide projections of errors incurred from the estimation of annualized fluxes of CO2 based on weekly measurements relative to daily and high-frequency (3 h) data such as those obtained at the Hawaii Kilo Nalu coastal time series station, which shows similar behavior to the Point B location despite significant differences in climate and hydrological

  10. Etiologies et pronostic des occlusions intestinales aigues mécaniques à l’Hôpital National de Zinder: étude transversale sur 171 patients

    PubMed Central

    Adamou, Harissou; Magagi, Ibrahim Amadou; Habou, Oumarou; Magagi, Amadou; Maazou, Halidou; Adamou, Mansour; Harouna, Yacouba

    2016-01-01

    L’occlusion intestinale aigue (OIA) mécanique, représente l’une des pathologies les plus fréquentes en chirurgie digestive d’urgence. L’objectif de cette étude était de décrire les aspects étiologiques et pronostiques des occlusions intestinales aigues mécaniques à l’Hôpital National de Zinder (HNZ), Niger. Il s’agissait d’une étude transversale sur 24 mois (Janvier 2013 à Décembre 2014) ayant inclus tous les patients opérés pour OIA. Les occlusions intestinales mécaniques représentaient 24,50% (n=171) des urgences chirurgicales digestives (n=622). L’âge médian était à 25 ans (extrêmes: 1 jour et 95 ans). Le sexe ratio était à 3,5 en faveur des hommes. Les enfants représentaient 38,60% (n=66). Le siège de l’obstacle était sur le grêle dans 60,82% (n=104), colique dans 21,63%(n=37) et mixte dans 17,54% (n=30). Le mécanisme par strangulation constituait 88,89% (n=152) dont les hernies étranglées avec 49,70% (n=85) et les invaginations intestinales aigues avec 19,88% (n=34) des patients. Les malformations ano-rectales et les tumeurs constituaient les principales étiologies par obstruction avec respectivement 7,02% (n=12) et 3,51% (n=6). Une résection intestinale était faite dans 52 cas (30,41%). Les complications septiques prédominaient (n=39/53), dont la suppuration pariétale (n=23). Le séjour moyen était de 7,82 jours. La mortalité globale était 11,70% (n=20). Celle-ci était corrélée statistiquement à la nécrose intestinale (p=0,01) et au retard d’admission (p=0,04). Les étiologies des OIA sont multiples et dominées par les hernies étranglées. La morbi-mortalité élevée qu’elles entrainent pourrait être évitée par la prise en charge précoce avant l’installation d’une nécrose intestinale.

  11. Suivi prospectif sur 5 ans des tentatives de suicide en population clinique dans la région de Fès, Maroc

    PubMed Central

    Aarab, Chadya; Elghazouani, Fatima; Aalouane, Rachid; Rammouz, Ismail

    2014-01-01

    Au Maroc, les tentatives de suicide (TS) demeurent un sujet mal évalué à cause de considérations socioculturelles et l'absence d'approche longitudinale. L'objectif principal était d’évaluer le devenir des suicidants après 5ans au centre universitaire psychiatrique de Fès, les objectifs secondaires étaient l'estimation de la prévalence des TS, préciser les étiologies les plus fréquentes, et établir une corrélation entre les paramètres sociodémographiques, cliniques et évolutifs. Etude prospective à visée transversale et longitudinale, incluant les suicidants vus à l'hôpital psychiatrique de Fès, avec un suivi longitudinal sur 5ans. L’évaluation a été faite par un hétéro-questionnaire et le Mini International Neuropsychiatric Interview (MINI) cherchant le trouble psychiatrique sous jacent. On a recruté 105 patients suicidants, 62% des femmes, l’âge moyen est de 29,23ans. La prévalence des tentatives de suicide est de 3% sur l'ensemble des consultants à l’établissement. Les troubles de l'humeur, psychotiques et de personnalité ont occupé respectivement 37,6%, 27,7%, et 25,7% des cas. La récidive suicidaire a été notée chez 54% des patients, était significativement corrélée à la vie solitaire (P: 0,039) et à la présence d'antécédents familiaux de TS (P: 0,046). L'utilisation de moyens violents était significativement fréquente chez les patients psychotiques. Après 5ans, 32 patients ont répondu à notre appel. Le taux de récidive était de 15%. On a noté trois cas de décès dont deux suicides confirmés. Les résultats confirment les données de la littérature scientifique avec certaines particularités cliniques et évolutives. PMID:25478042

  12. Qualité des certificats de coups et blessures volontaires sur adultes à Dakar et Diourbel, Sénégal

    PubMed Central

    Soumah, Mohamed Maniboliot; Ngwa, Hugues Elie Elame; Ndiaye, Mor; Sow, Mamadou Lamine

    2011-01-01

    Introduction Le certificat médical est une attestation écrite, destinée à constater un fait d'ordre médical. L'intérêt de cette étude résultait de la fréquence du contentieux entre représentants de la loi et médecins à propos des certificats médicaux descriptifs de coups et blessures volontaires. Les objectifs étaient d’étudier les critères d’établissement des certificats médicaux dans les cas de coups et blessures volontaires, d’évaluer la qualité des certificats médicaux dans les procédures judiciaires dans les régions de Dakar et de Diourbel, d'apprécier l’évaluation de l'Incapacité Totale de Travail fixée par les médecins et leurs implications judiciaires. Méthodes Nous avons étudié 201 certificats descriptifs de constatation de coups et blessures volontaires. L'incapacité totale de travail (ITT) au sens pénal a été revue par un médecin légiste. Les données recueillies ont été saisies et analysées par logiciel Epi Data version 3.1 et Epi Info 6.04. Résultats Le nom et les prénoms du médecin étaient mentionnés sur les 201 certificats. Sur les 201 certificats étudiés, 170 mentionnaient les faits rapportés par la victime. En proposant de manière comparative pour chacune des ITT fixées par le médecin, une ITT pénale, nous trouvions des erreurs entre ITT pénale et ITT civile (dans 95% des cas). Conclusion Les certificats médicaux délivrés sont incomplets. Les recommandations concernent la création d'unités médico-judiciaires et de centres d'accueil des victimes d'agression. PMID:22384305

  13. Polymorphisme de l'apolipoprotéine E dans la population du nord du Maroc: fréquence et influence sur les paramètres lipidiques

    PubMed Central

    Benyahya, Fatiha; Barakat, Amina; Ghailani, Naima; Bennani, Mohcine

    2013-01-01

    Introduction L'objectif de ce travail est de déterminer les fréquences alléliques et génotypiques des sites polymorphes situés dans le gène de l'apolipoprotéine E (apo E) ainsi que leur impact sur les paramètres cliniques et lipidiques dans un échantillon de la population du nord du Maroc cliniquement diagnostiqué ADH. Méthodes Le génotype de l'apo E a été analysé par séquençage direct chez 46 patients cliniquement diagnostiqués ADH selon les critères standards. Résultats Les fréquences des allèles epsilon 3, epsilon 2 et epsilon 4 ont été respectivement 78.3%, 2.2% et 19.6%. La fréquence de l'allèle epsilon 4 est très élevée chez la population du nord du Maroc en comparaison avec les populations des autres régions marocaines. Elle est similaire à celle rapportée dans les pays de l'Europe du nord. Les taux du cholestérol total, du cholestérol LDL ainsi que la présence des xanthomes et les maladies cardiovasculaires ne différent pas entre les génotypes de l'apoE. En revanche, les résultats ont montré une influence de l'allèle epsilon4 sur le taux des triglycérides chez les sujets obèses. Conclusion Le génotype de l'apoE ne peut expliquer le phénotype clinique et biochimique présenté par des patients du Nord du Maroc cliniquement diagnostiqués ADH. PMID:24396563

  14. Biomagnification of mercury and its antagonistic interaction with selenium in yellowfin tuna Thunnus albacares in the trophic web of Baja California Sur, Mexico.

    PubMed

    Ordiano-Flores, Alfredo; Rosíles-Martínez, Rene; Galván-Magaña, Felipe

    2012-12-01

    Mercury and selenium concentrations were determined in muscle of 37 yellowfin tuna (Thunnus albacares) captured aboard of Mexican purse-seiners boats off western coast of Baja California Sur, between Punta Eugenia and Cabo Falso, from October to December 2006. Also, its prey (mainly, jumbo squid Dosidicus gigas and pelagic red crab Pleuroncodes planipes) were analyzed from the stomach contents. All the mercury values obtained were lower that mercury content recommended by standard legal limits for seafood adopted by Mexican norms (typically 0.5-1.0μg g(-1)). Mercury concentrations vary between 0.06 and 0.51μg g(-1) in yellowfin tuna, and from 0.01 to 0.20μg g(-1) in its prey, suggesting that mercury can accumulate in prey tissues and that of their predator. Biomagnification factors (BMF) between predator-prey associations were calculated. The BMFs were >1, indicating that mercury biomagnifies along the food web of yellowfin tuna. In all species studied there was a molar excess of selenium over mercury. The rank order of mean selenium/mercury molar ratios was for pufferfish (42.62)> diamond squid (15.09)>yellowfin tuna (10.29)>pelagic red crab (10.05)>panama lightfish (9.54)> jumbo squid (8.91). The selenium health benefit value (Se-HBV) was calculated to have an improved understanding of the health benefits and risk of fish consumption.

  15. Consequences experimentales des effets des fluctuations du vide sur la fluorescence parametrique et la generation du second harmonique en milieu confine

    NASA Astrophysics Data System (ADS)

    Robichaud, Luc

    Les fluctuations du vide, qui consistent en l'apparition momentanee de particules, ce qui est permit par le principe d'incertitude de Heisenberg, joue un role primordial dans les processus photoniques, en particulier les processus non-lineaires. Par la manipulation de ces fluctuations du vide a l'aide de confinement optique, on retrouve deux phenomenes particuliers : l'intensification de la fluorescence parametrique (Walker, 2008) et l'inhibition de la generation du second harmonique (Collette, 2013). Dans ce travail, on presente les resultats dans le cas classique ; c'est-a-dire sans fluctuations du vide et confinement. Par la suite, on presente les effets des fluctuations du vide et du confinement, ce qui mene aux deux effets mentionnes. Dans le cas de la fluorescence parametrique, le bruit quantique sur le champ interne et externe est calcule, le role du desaccord de phase dans le modele est expose et une generalisation tridimensionnelle est etudiee afin de generaliser la conception du modele d'un cas unidimensionnel a un cas tridimensionnel planaire. Dans le cas de la generation du second harmonique, les difficultes d'un modele purement tridimensionnel sont exposees et ensuite le cas limite planaire est etudie.

  16. Overview of 3D Documentation Data and Tools available for Archaeological Researches: case study of the Romanesque Church of Dugny-sur-Meuse (France)

    NASA Astrophysics Data System (ADS)

    Macher, H.; Grussenmeyer, P.; Kraemer, C.; Guillemin, S.

    2015-08-01

    In this paper, the 3D documentation of the full structure of the Romanesque church of Dugny-sur-Meuse is discussed. In 2012 and 2013, a 3D recording project was carried out under the supervision of the Photogrammetry and Geomatics Research Group from INSA Strasbourg (France) in cooperation with C. Kraemer, archaeologist from Nancy (France). The goal of the project was on one hand to propose new solutions and tools to the archaeologists in charge of the project especially for stone by stone measurements. On the other hand, a simplified 3D model was required by the local authorities for communication purposes. To achieve these goals several techniques were applied namely GNSS measurements and accurate traverse networks, photogrammetric recordings and terrestrial laser scanning acquisitions. The various acquired data are presented in this paper. Based on these data, several deliverables are also proposed. The generation of orthoimages from plane as well as cylindrical surfaces is considered. Moreover, the workflow for the creation of a 3D simplified model is also presented.

  17. A probable case of gigantism/acromegaly in skeletal remains from the Jewish necropolis of "Ronda Sur" (Lucena, Córdoba, Spain; VIII-XII centuries CE).

    PubMed

    Viciano, Joan; De Luca, Stefano; López-Lázaro, Sandra; Botella, Daniel; Diéguez-Ramírez, Juan Pablo

    2015-01-01

    Pituitary gigantism is a rare endocrine disorder caused by hypersecretion of growth hormone during growing period. Individuals with this disorder have an enormous growth in height and associated degenerative changes. The continued hypersecretion of growth hormone during adulthood leads to acromegaly, a condition related to the disproportionate bone growth of the skull, hands and feet. The skeletal remains studied belong to a young adult male from the Jewish necropolis of "Ronda Sur" in Lucena (Córdoba, Spain, VIII-XII centuries CE). The individual shows a very large and thick neurocranium, pronounced supraorbital ridges, an extremely prominent occipital protuberance, and an extremely large and massive mandible. Additional pathologies include enlargement of the vertebral bodies with degenerative changes, thickened ribs, and a slight increased length of the diaphysis with an increased cortical bone thickness of lower limbs. Comparative metric analysis of the mandible with other individuals from the same population and a contemporary Mediterranean population shows a trend toward acromegalic morphology. This case is an important contribution in paleopathological literature because it is a rare condition that has not been widely documented in ancient skeletal remains. PMID:25776010

  18. Fiabilité des structures mécaniques adaptatives: effet de la panne des actionneurs ou des capteurs sur la stabilité

    NASA Astrophysics Data System (ADS)

    Fall, H.; Charon, W.; Kouta, R.

    2002-12-01

    Ces dernières décennies, des activités significatives dans le monde étaient dirigées autour du contrôle actif. Le but de ces recherches était essentiellement d'améliorer les performances, la fiabilité et la sécurité des systèmes. Notamment dans le cas des structures soumises à des vibrations aléatoires. D'importants travaux ont été consacré à l'utilisation des “matériaux intelligents” comme capteurs et actionneurs. Cette article propose l'analyse de la fiabilité des systèmes mécaniques en étudiant les pannes des actionneurs ou des capteurs. L'effet de ces pannes sur la stabilité et la performance du système y est démontré. Les méthodologies de conception y sont rappelées. Des exemples numériques sont fournis à travers le contrôle d'un panneau sous chargement dynamique pour illustrer la méthode proposée.

  19. Application d'une technique de modelisation aerodynamique conceptuelle sur la simulation d'un pilote automatique a commande optimale pour un avion d'affaires

    NASA Astrophysics Data System (ADS)

    Pollender-Moreau, Olivier

    Ce document présente, dans le cadre d'un contexte conceptuel, une méthode d'enchaînement servant à faire le lien entre les différentes étapes qui permettent de réaliser la simulation d'un aéronef à partir de ses données géométriques et de ses propriétés massiques. En utilisant le cas de l'avion d'affaires Hawker 800XP de la compagnie Hawker Beechcraft, on démontre, via des données, un processus de traitement par lots et une plate-forme de simulation, comment (1) modéliser la géométrie d'un aéronef en plusieurs surfaces, (2) calculer les forces aérodynamiques selon une technique connue sous le nom de Vortex Lattice Method, (3) construire un modèle de vol servant à la simulation des aéronefs pour leur enveloppe de vol en ajoutant des fonctions supplémentaires, (4) construire un modèle de turbosoufflante simplifié, (5) développer un algorithme d'équilibre (trim) du mouvement longitudinal, (6) développer des algorithmes de contrôle à commande moderne, (7) développer certaines fonctions d'un système de pilotage automatique, et (8) rassembler le tout sous une même plate-forme de simulation. Afin de supporter ce travail, une application publique Matlab, connue sous le nom de Tornado, est utilisée conjointement avec d'autres fonctions pour la conception du modèle de vol aérodynamique. D'ailleurs, il sera démontré que le modèle de vol, quoiqu'il soit quand même crédible, ne concorde pas tout à fait avec les données de référence. Par contre, puisque le modèle des moteurs fonctionne bien, que l'algorithme d'équilibrage du mouvement longitudinal fonctionne bien et que les pôles des systèmes dynamiques concordent avec la littérature, les tests dynamiques effectués au sein de la plate-forme de simulation permettent d'obtenir des résultats fonctionnels et crédibles. D'ailleurs, deux systèmes d'augmentation de la stabilité basés sur la méthode de contrôle moderne LQR et couvrant l

  20. Biomagnification of mercury and its antagonistic interaction with selenium in yellowfin tuna Thunnus albacares in the trophic web of Baja California Sur, Mexico.

    PubMed

    Ordiano-Flores, Alfredo; Rosíles-Martínez, Rene; Galván-Magaña, Felipe

    2012-12-01

    Mercury and selenium concentrations were determined in muscle of 37 yellowfin tuna (Thunnus albacares) captured aboard of Mexican purse-seiners boats off western coast of Baja California Sur, between Punta Eugenia and Cabo Falso, from October to December 2006. Also, its prey (mainly, jumbo squid Dosidicus gigas and pelagic red crab Pleuroncodes planipes) were analyzed from the stomach contents. All the mercury values obtained were lower that mercury content recommended by standard legal limits for seafood adopted by Mexican norms (typically 0.5-1.0μg g(-1)). Mercury concentrations vary between 0.06 and 0.51μg g(-1) in yellowfin tuna, and from 0.01 to 0.20μg g(-1) in its prey, suggesting that mercury can accumulate in prey tissues and that of their predator. Biomagnification factors (BMF) between predator-prey associations were calculated. The BMFs were >1, indicating that mercury biomagnifies along the food web of yellowfin tuna. In all species studied there was a molar excess of selenium over mercury. The rank order of mean selenium/mercury molar ratios was for pufferfish (42.62)> diamond squid (15.09)>yellowfin tuna (10.29)>pelagic red crab (10.05)>panama lightfish (9.54)> jumbo squid (8.91). The selenium health benefit value (Se-HBV) was calculated to have an improved understanding of the health benefits and risk of fish consumption. PMID:23059106

  1. Fine scale daily movements and habitat use of East Pacific green turtles at a shallow coastal lagoon in Baja California Sur, Mexico

    USGS Publications Warehouse

    Senko, Jesse; Koch, Volker; Megill, William M.; Carthy, Raymond R.; Templeton, R.obert P.; Nichols, Wallace J.

    2010-01-01

    Green turtles spend most of their lives in coastal foraging areas where they face multiple anthropogenic impacts. Therefore, understanding their spatial use in this environment is a priority for conservation efforts. We studied the fine scale daily movements and habitat use of East Pacific green turtles (Chelonia mydas) at Laguna San Ignacio, a shallow coastal lagoon in Baja California Sur, Mexico where sea turtles are subject to high levels of gillnet bycatch and directed hunting. Six turtles ranging from 44.6 to 83.5 cm in straight carapace length were tracked for short deployments (1 to 6 d) with GPS-VHF telemetry. Turtles were active throughout diurnal, nocturnal, and crepuscular periods. Although they moved greater total distances during daytime, their speed of travel and net displacement remained consistent throughout 24-h periods. A positive selection for areas of seagrass and moderate water depth (5 to 10 m) was determined using Ivlev's electivity index, with neutral selection for shallow water (< 5 m) and avoidance of deep water (> 10 m). Turtles exhibited two distinct behavioral movement patterns: circular movements with high fidelity to the capture–release location and meandering movements with low fidelity to the capture–release location. Our results indicate that green turtles were active throughout the diel cycle while traveling large distances and traversing multiple habitats over short temporal scales.

  2. Palaeo-ecological quality status based on foraminifera of Boulogne-sur-Mer harbour (Pas-de-Calais, Northeastern France) over the last 200 years.

    PubMed

    Francescangeli, F; Armynot du Chatelet, E; Billon, G; Trentesaux, A; Bouchet, V M P

    2016-06-01

    Over the last centuries, coastal areas have experienced dramatic degradations of their environmental quality, which has led to a huge reduction of marine biodiversity. The objective of the present study was to use geochemical parameters and benthic fossil foraminifera to assess environmental changes that have occurred over the last 200 years in a harbour area (Boulogne-sur-Mer, Northern France) heavily modified by human activities. A multidisciplinary approach including major and trace metals, grain-size, total organic carbon and benthic fossil foraminifera, has been performed on a 33-cm long core. The dating was carried out using the activity of (210)Pb and (137)Cs. Embayment of the area and increase of trace metals concentrations induced a shift in benthic communities. Human activities modified a sandy nearshore bank, colonized by typical marine foraminiferal species, such as Cribroelphiudium excavatum, into a sheltered environment, dominated by brackish end-members, such as Haynesina germanica. Along the sedimentary record, the interaction between meiofaunal and geochemical elements made it possible to distinguish between a pre-impacted period and an industrial period. The upper part of the core reflects better ecological conditions, indicating an environmental recovery. Our results provide baselines for future environmental bio-monitoring in the area. PMID:27074196

  3. Rapport sur l'état du patrimoine astronomique dans les observatoires français de la fin du XIXè siècle

    NASA Astrophysics Data System (ADS)

    Damm, E.; Pécontal, E.

    2012-12-01

    Suite au colloque sur la sauvegarde du patrimoine astronomique organisé par le MAEE et la SAF, sous l'égide de l'UNESCO, qui a conduit à l'adoption de la Déclaration de Paris, les directeurs d'observatoires institutionnels qui étaient absents du colloque ont ressenti le besoin de discuter de ces conclusions prises en leur nom. L'initiative d'organiser une réunion des directeurs des Observatoires des Sciences de l'Univers (OSU) à ce sujet le 30 janvier 2012 a été prise par François Vernotte, directeur de l'Observatoire de Besançon. Le présent compte-rendu de visite résulte d'une initiative spontanée d'Emmanuel Pécontal, astronome responsable du Patrimoine à l'observatoire de Lyon, et d'Evelyne Damm, membre de la Commission Nationale de classement des Monuments Historiques (CNMH) et élue à la communauté d'agglomération des Portes de l'Essonne oû est sis l'observatoire de Camille Flammarion.

  4. A probable case of gigantism/acromegaly in skeletal remains from the Jewish necropolis of "Ronda Sur" (Lucena, Córdoba, Spain; VIII-XII centuries CE).

    PubMed

    Viciano, Joan; De Luca, Stefano; López-Lázaro, Sandra; Botella, Daniel; Diéguez-Ramírez, Juan Pablo

    2015-01-01

    Pituitary gigantism is a rare endocrine disorder caused by hypersecretion of growth hormone during growing period. Individuals with this disorder have an enormous growth in height and associated degenerative changes. The continued hypersecretion of growth hormone during adulthood leads to acromegaly, a condition related to the disproportionate bone growth of the skull, hands and feet. The skeletal remains studied belong to a young adult male from the Jewish necropolis of "Ronda Sur" in Lucena (Córdoba, Spain, VIII-XII centuries CE). The individual shows a very large and thick neurocranium, pronounced supraorbital ridges, an extremely prominent occipital protuberance, and an extremely large and massive mandible. Additional pathologies include enlargement of the vertebral bodies with degenerative changes, thickened ribs, and a slight increased length of the diaphysis with an increased cortical bone thickness of lower limbs. Comparative metric analysis of the mandible with other individuals from the same population and a contemporary Mediterranean population shows a trend toward acromegalic morphology. This case is an important contribution in paleopathological literature because it is a rare condition that has not been widely documented in ancient skeletal remains.

  5. Mise à jour sur la prévention et le dépistage selon l’âge à l’intention des médecins de soins primaires canadiens

    PubMed Central

    Shimizu, Tawnya; Bouchard, Manon; Mavriplis, Cleo

    2016-01-01

    Résumé Objectif Faire la synthèse des meilleures lignes directrices fondées sur des données probantes concernant la prévention et le dépistage chez les adultes canadiens selon l’âge. Qualité des données Les recommandations du Groupe d’étude canadien sur les soins de santé préventifs représentent la source principale des renseignements et sont complétées par les recommandations pertinentes du Preventive Services Task Force des États-Unis lorsque celles du Groupe d’étude canadien étaient inaccessibles ou désuètes. Les guides de pratique des principales organisations nationales axées spécifiquement sur une maladie ou une spécialité ont aussi fait l’objet d’une révision pour prendre en compte les données factuelles les plus récentes. Message principal Les interventions de dépistage recommandées selon l’âge et le sexe sont présentées dans un tableau de synthèse où est mise en évidence la qualité des données à l’appui de ces recommandations. Un exemple de modèle à suivre dans les dossiers médicaux électroniques ou sur papier est aussi proposé. Conclusion Qu’il s’agisse d’une visite consacrée à la prévention ou d’une occasion saisie autrement de faire du counseling et du dépistage de prévention chez leurs patients, les médecins de soins primaires peuvent se servir de cette synthèse des recommandations fondées sur des données probantes pour maximiser leur efficience et prévenir d’importantes omissions ou des dépistages inutiles.

  6. Assessment by regional modelling of the impact of monopile foundations on the hydrodynamics and sediment transport: case of Courseulles-sur-Mer (France) wind farm

    NASA Astrophysics Data System (ADS)

    Rivier, Aurélie; Bennis, Anne-Claire; Pinon, Grégory; Magar, Vanesa; Gross, Markus

    2015-04-01

    Offshore monopile foundations of wind turbines modify hydrodynamics and sediment transport at local scale and also at regional scale. The aim of this work is to assess these changes and to parametrize them in a regional model. These modifications were previously evaluated using the regional circulation model MARS3D (Lazure and Dumas, 2008) in tests-cases (Rivier et al., 2014) using two approaches: in the first approach, monopiles are explicitly modelled in the mesh as dry cells and in the second approach a sub-grid parametrization which considers the drag force exerted by a monopile on the flow is used. The sub-grid parametrization is improved close to the bed in this paper by adding a drag force term in the momentum equations, source terms in the turbulence model and by increasing the bed shear stress at monopile location. Changes in hydrodynamics regime, especially near-bed, affect sediment transport regime and modifications due to monopiles on sediment dynamics is also investigated using the MARS3D sediment transport module (Le Hir et al., 2011) which solves the advection-diffusion equations. Test-cases are run using hydrodynamical conditions and sediment grain sizes typical from the area located off Courseulles-sur-Mer (Normandy, France) where an offshore wind farm is planned to be built. Velocity, turbulent kinetic energy and bed thickness changes due to the monopile simulated by both approaches are compared to each other and to experimental measurements made in a flume at the University of Caen or to published data (e.g. Roulund et al., 2005; Dargahi,1989). Then the model is applied in a real configuration on an area including the future offshore wind farm of Courseulles-sur-Mer. Four monopiles are represented in the model using both approaches and modifications of the hydrodynamics and sediment transport are assessed along a tidal cycle. Currents increase at the side edge of the monopile and decrease in front of and downstream the monopile. Turbulent kinetic

  7. Prevalence and risk factors for intestinal parasitic infections in a rural community in "consolación del sur" municipality, cuba.

    PubMed

    Pino Santos, A; Núñez Fernández, F A; Martínez Sánchez, R; Domenech Cañete, I; Rodríguez, M; Jeres Puebla, L; Rodríguez González, Z

    2014-08-01

    Intestinal parasites are very common infections worldwide and they are responsible for significant public health problems. The World Health Organization estimates that one-third of the world population is infected and some epidemiologic factors related to the transmission have been identified. The purpose of this investigation was to study the prevalence of intestinal parasitic infections in people living in the rural community of "El Canal", Consolación del Sur municipality and the association with some epidemiologic risk factors. All participants were subjected to three methods of parasitological examinations on the stool samples and by immunodiagnostic tests which allow the detection of excretory-secretory antigens of adults with Fasciola hepatica. The global prevalence rate of intestinal parasitic infections (IPIs) was 18%, and 16.7% for protozoan infections, while the rate of helminth infection was lower (5.3%) in the population studied. The univariate analysis identified three factors associated with intestinal pathogenic protozoan infections which include livestock work, drinking water from well\\river and eating unwashed fruits\\vegetables. The multivariate analysis using introduction test logistic regression ratified the association of these risk factors. Contrary to what have been published in the majority of Cuban studies carried out in rural places, a higher prevalence of protozoan than helminth infection was found. This discrepancy may be explained because the majority of the workers in this rural community were stock-breeders and they are not involved in other agricultural work. The identification of risk factors is important in order to design appropriate strategies for control of IPIs in communities. PMID:25429477

  8. High-resolution seismic-reflection and marine-magnetic data from offshore central California--San Gregorio to Point Sur

    USGS Publications Warehouse

    Sliter, Ray W.; Johnson, Samuel Y.; Watt, Janet T.; Scheirer, Daniel S.; Allwardt, Parker; Triezenberg, Peter J.

    2013-01-01

    The U.S. Geological Survey collected high-resolution seismic-reflection data on four surveys (S-N1-09-MB, S-15-10-NC, S-06-11-MB, and S-04-12-MB) and marine-magnetic data on one survey (S-06-11-MB) between 2009 and 2012, offshore of central California between San Gregorio and Point Sur. This work was supported in part by the California Seafloor Mapping Program. The survey areas span about 120 km of California's coast (including Monterey Bay). Most data were collected aboard the U.S. Geological Survey R/V Parke Snavely. Cumulatively, approximately 1,410 km of single-channel seismic-reflection data were acquired, mainly using a SIG 2mille minisparker. About 44 km of data were collected simultaneously using an EdgeTech Chirp 512. Subbottom acoustic penetration spanned tens to several hundreds of meters, variable by location. Marine magnetic data were collected on approximately 460 km of track lines (mainly in southern Monterey Bay) using a Geometrics G882 cesium-vapor marine magnetometer. This report includes maps and navigation files of the surveyed transects, linked to Google Earth™ software, as well as digital data files showing images of each transect in SEG-Y and JPEG formats. The images of bedrock, sediment deposits, and tectonic structure provide geologic information that is essential to hazard assessment, regional sediment management, and coastal and marine spatial planning at Federal, State and local levels, as well as to future research on the geomorphic, sedimentary, tectonic, and climatic record of central California.

  9. Numerical modelling of circulation and dispersion processes in Boulogne-sur-Mer harbour (Eastern English Channel): sensitivity to physical forcing and harbour design

    NASA Astrophysics Data System (ADS)

    Jouanneau, Nicolas; Sentchev, Alexei; Dumas, Franck

    2013-12-01

    The MARS-3D model in conjunction with the particle tracking module Ichthyop is used to study circulation and tracer dynamics under a variety of forcing conditions in the eastern English Channel, and in the Boulogne-sur-Mer harbour (referred to hereafter as BLH). Results of hydrodynamic modelling are validated against the tidal gauge data, VHF radar surface velocities and ADCP measurements. Lagrangian tracking experiments are performed with passive particles to study tracer dispersal along the northern French coast, with special emphasis on the BLH. Simulations revealed an anticyclonic eddy generated in the harbour at rising tide. Tracers, released during flood tide at the Liane river mouth, move northward with powerful clockwise rotating current. After the high water, the current direction changes to westward, and tracers leave the harbour through the open boundary. During ebb tide, currents convergence along the western open boundary but no eddy is formed, surface currents inside the harbour are much weaker and the tracer excursion length is small. After the current reversal at low water, particles are advected shoreward resulting in a significant increase of the residence time of tracers released during ebb tide. The effect of wind on particle dispersion was found to be particularly strong. Under strong SW wind, the residence time of particles released during flood tide increases from 1.5 to 6 days. For release during ebb tide, SW wind weakens the southward tidally induced drift and thus the residence time decreases. Similar effects are observed when the freshwater inflow to the harbour is increased from 2 to 10 m3/s during the ebb tide flow. For flood tide conditions, the effect of freshwater inflow is less significant. We also demonstrate an example of innovative coastal management targeted at the reduction of the residence time of the pathogenic material accidentally released in the harbour.

  10. Explaining the appeal for immigrant men who have sex with men of a community-based rapid HIV-testing site in Montreal (Actuel sur Rue).

    PubMed

    Lessard, David; Lebouché, Bertrand; Engler, Kim; Thomas, Réjean; Machouf, Nimâ

    2015-01-01

    Immigrant men who have sex with men (MSM) are vulnerable to HIV. In the last decade, several rapid HIV-testing facilities targeting MSM have been established around the world and seem popular among immigrants. This study analyzes factors contributing to immigrant MSM's use of Actuel sur Rue (AsR), a community-based rapid HIV-testing site in Montreal's gay village, where 31% of clients are immigrants. From October 2013 to January 2014, AsR staff compiled a list of new clients born outside of Canada. With their consent, 40 immigrant MSM were reached among these new clients for a 15-minute phone survey entailing open-ended and multiple-choice questions. The survey sought immigrant MSM's reasons for visiting AsR; satisfaction with service and staff; and open comments. An inductive thematic analysis was conducted with the qualitative data, and descriptive statistics were produced with the quantitative data. The qualitative findings indicate that the main reasons for seeking an HIV test were a recent risk, routine testing, or being in a new relationship. Clients chose AsR mainly because it is easily accessible, service is fast or they heard about it from a friend. The quantitative findings indicate that rates of satisfaction were high (over 90% were satisfied about all aspects except for openings hours) and more than 80% felt comfortable while receiving services at AsR. Nevertheless, this study's findings have implications for improving services. They stress the importance of offering rapid yet comprehensive service and of taking into account immigrant MSM's concerns for confidentiality.

  11. [Spatial and biogeographic characterization of macroalgal assemblages from Bahía del Rincón, Baja California Sur, Mexico].

    PubMed

    Riosmena-Rodríguez, R; Hinojosa-Arango, G; López-Vivas, J M; León-Cisneros, K; Holguin-Acosta, E

    2005-01-01

    Macroalgal studies in Baja California Sur have dealt mainly with occurrence and seasonality, but some areas are poorly known even for these basic data. Bahia del Rincón-La Rivera is an important high-productivity fisheries area where coastal infrastructure development is under way. A spatial characterization of the marine flora from Bahia del Rincón-La Rivera was done by intensive sampling at different depths and localities with skin and SCUBA diving. At least 500 m2 were surveyed in each site. Additionally. quantitative sampling was done in ten random 25 cm2 quadrates per site. In the intertidal section, density and cover estimates were used. We also investigated the historical records and geographical affinities. A total of 72 species were identified (most were red algae: 62%). We found no general trend in the biogeographical affinities, which varied with each taxonomic group. Most brown algae species were tropical-endemic; red algae temperate-cosmopolite and green algae tropical-cosmopolite. In the spatial assemblage structure we found a high similarity between the intertidal areas, but a low similarity in shallow or deeper areas (3-5 m). This pattern was the same when we compared the abundance of the main species. We suggest that there are significant spatial differences in recruitment and development of the assemblages in relation to vertical distribution (depth) and position along the shore. There is a clear-cut Gelidium-Jania belt in the intertidal zone and a Padina-Dictyota belt below the low tide. Sporadic and year-round species occur in the intertidal zone, annual and perennial species below the low tide line. Sites differ in recruitment and this affects the abundance of other species (such as coraline and Caulerpa species). Temperature and sedimentation affect seasonality, but community structure is relatively constant throughout the year.

  12. Lignes directrices sur la prise en charge en soins primaires des céphalées chez l’adulte

    PubMed Central

    Becker, Werner J.; Findlay, Ted; Moga, Carmen; Scott, N. Ann; Harstall, Christa; Taenzer, Paul

    2015-01-01

    Résumé Objectif Accroître l’utilisation d’approches éclairées par des données probantes pour diagnostiquer, investiguer et traiter en soins primaires les céphalées des patients. Qualité des données Une recherche documentaire exhaustive a été effectuée pour trouver des lignes directrices et des révisions systématiques publiées entre janvier 2000 et mai 2011. La grille d’évaluation de la qualité des recommandations pour la pratique clinique AGREE a servi à l’analyse critique des lignes directrices. Les 6 guides de pratique clinique de la plus grande qualité ont servi de base dans le processus d’adaptation. Message principal Un groupe d’élaboration multidisciplinaire de professionnels des soins primaires ont formulé 91 recommandations précises à l’aide d’un processus consensuel. Les recommandations portent sur le diagnostic, l’investigation et la prise en charge de la migraine, de la céphalée de tension, de la céphalée due à une surmédication et de la céphalée vasculaire de Horton. Conclusion Un guide de pratique clinique adapté au contexte des soins de santé au Canada a été produit en suivant un processus d’adaptation de lignes directrices dans le but d’aider les professionnels de toutes les disciplines des soins primaires à dispenser des soins éclairés par des données probantes aux patients souffrant de céphalées.

  13. Elemental concentrations in different species of seaweeds from Loreto Bay, Baja California Sur, Mexico: implications for the geochemical control of metals in algal tissue.

    PubMed

    Sánchez-Rodríguez, I; Huerta-Diaz, M A; Choumiline, E; Holguín-Quiñones, O; Zertuche-González, J A

    2001-01-01

    Concentration levels of 21 elements were analyzed by instrumental neutron activation analysis (Rb, Cs, Ca, Sr, Ba, Sc, Cr, Fe, Co, Ni, Zn, Se, As, Sb, Th, U, Br, Hf, Ta, Zr, and Ag) in seven different seaweed species (Codium cuneatum, Sargassum sinicola, Padina durvillaei, Laurencia johnstonii, L. papillosa, Gracilaria pachidermatica and Hypnea pannosa), collected in a shallow coastal zone from Bahia de Loreto, Baja California Sur, Mexico. Measured concentrations in algal tissue spanned almost eight orders of magnitude (from 2.0 x 10(-3) microg g(-1) for Hf to 1.2 x 10(5) microg g(-1) for Ca). Ca was consistently the most abundant element in all analyzed seaweeds, followed by Fe and Sr. Brown algae showed a tendency to incorporate higher concentrations of elements than red and green algae. Additionally, there were significant linear correlations (P < 0.05 to P < 0.001) between a total of 76 different pairs of elements, some of them (e.g. Rb-Ni, Rb-Ag, Sc Cr, Sc-Fe, Sc Ni, Sc Hf, Cr Fe, Fe Ni, Fe-Hf and Ni-Th) highly correlated (r2 > 0.900). A significant correlation (r2 = 0.701, n = 18, P < 0.001) exists between our measurements in the tissue of algae and their corresponding average elemental concentrations in oceanic water from the North Pacific Ocean. Hence, overall elemental abundance in algal tissue apparently is controlled by the elemental abundance in oceanic water, whereas metabolic processes as well as environmental factors relevant to each region modify the final concentration of a given element in the body of a macroalgae.

  14. Cestodes of the blue shark, Prionace glauca (Linnaeus 1758), (Carcharhiniformes: Carcharhinidae), off the west coast of Baja California Sur, Mexico.

    PubMed

    Méndez, Oscar; Galván-Magaña, Felipe

    2016-01-01

    The cestode species recovered from the spiral intestines of 27 blue sharks (Prionace glauca) (Linnaeus, 1758) are reported from the western coast of Baja California Sur (BCS). The sampling was undertaken on a monthly basis from January 2003 to January 2004. The helminthological examination indicated the presence of four species of cestodes: Platybothrium auriculatum Yamaguti, 1952; Prosobothrium japonicum Yamaguti, 1934; Anthobothrium caseyi (Yamaguti, 1934) Ruhnke & Caira, 2009; and Paraorygmatobothrium prionacis (Yamaguti, 1934) Ruhnke, 1994. Of all the 27 sharks examined, 88.8% were infected with at least one cestode species. The most frequent species was P. auriculatum infecting 85% of the spiral intestines examined. In contrast the species with the highest mean intensity was P. prionacis (80.4 200). The species richness of cestodes in P. glauca is very similar in other regions of the world despite its wide distribution; however, this richness is low compared with other species of sharks within the same family. The feeding and host-specific are important factors that influence the parameters of infection of cestodes in this shark. On the west coast of BCS, Prionace glauca feeds mainly on red crab Pleuroncodes planipes Stimpson, 1860; squids Gonatus californiensis Young, 1972, Ancistrocheirus lesueurii (D'Orbigny, 1842), Haliphron atlanticus Steenstrup, 1861, and low proportion of fish teleosts as Merluccius productus (Ayres, 1855), Sardinops sp. Hubbs, 1929 and Scomber japonicus Houttuyn, 1872. We speculate that these prey could be involved as the second intermediate hosts of these cestodes, as in other members of these genera, although the life cycles of none are known. PMID:27394312

  15. Incidence of organochlorine pesticides and the health condition of nestling ospreys (Pandion haliaetus) at Laguna San Ignacio, a pristine area of Baja California Sur, Mexico.

    PubMed

    Rivera-Rodríguez, Laura B; Rodríguez-Estrella, Ricardo

    2011-01-01

    We identified and quantified organochlorine (OC) pesticide residues in the plasma of 28 osprey (Pandion haliaetus) nestlings from a dense population in Laguna San Ignacio, a pristine area of Baja California Sur, Mexico, during the 2001 breeding season. Sixteen OC pesticides were identified and quantified. α-, β-, δ- and γ-hexachlorocyclohexane, heptaclor, heptachlor epoxide, endosulfan I and II, endosulfan-sulfate, p,p'-DDE, p,p'-DDD, aldrin, dieldrin, endrin, endrin aldehyde, and endrin ketone were the OCs found in the plasma of nestlings, ranging from 0.002 to 6.856 pg/μl (parts per billion). No differences were found in the concentration of pesticides between genders (P > 0.05). In our work, the concentrations detected in the plasma were lower than those reported to be a threat for the species and that affect the survival and reproduction of birds. The presence of OC pesticides in the remote Laguna San Ignacio osprey population is an indication of the ubiquitous nature of these contaminants. OCs are apparently able to travel long distances from their source to the study area. A significant relationship between hemoglobin and mean corpuscular hemoglobin concentrations and OC concentrations were found suggesting that a potential effect on the health of chicks may exist in this osprey population caused by the OC, e.g. anemia. The total proteins were positively correlated with α-BHC, endosulfan I, and p,p'-DDD. It has been suggested that OC also affects competitive interactions and population status over the long term in vertebrate species, and our results could be used as reference information for comparison with other more exposed osprey populations. PMID:20949316

  16. Cestodes of the blue shark, Prionace glauca (Linnaeus 1758), (Carcharhiniformes: Carcharhinidae), off the west coast of Baja California Sur, Mexico.

    PubMed

    Méndez, Oscar; Galván-Magaña, Felipe

    2016-03-03

    The cestode species recovered from the spiral intestines of 27 blue sharks (Prionace glauca) (Linnaeus, 1758) are reported from the western coast of Baja California Sur (BCS). The sampling was undertaken on a monthly basis from January 2003 to January 2004. The helminthological examination indicated the presence of four species of cestodes: Platybothrium auriculatum Yamaguti, 1952; Prosobothrium japonicum Yamaguti, 1934; Anthobothrium caseyi (Yamaguti, 1934) Ruhnke & Caira, 2009; and Paraorygmatobothrium prionacis (Yamaguti, 1934) Ruhnke, 1994. Of all the 27 sharks examined, 88.8% were infected with at least one cestode species. The most frequent species was P. auriculatum infecting 85% of the spiral intestines examined. In contrast the species with the highest mean intensity was P. prionacis (80.4 200). The species richness of cestodes in P. glauca is very similar in other regions of the world despite its wide distribution; however, this richness is low compared with other species of sharks within the same family. The feeding and host-specific are important factors that influence the parameters of infection of cestodes in this shark. On the west coast of BCS, Prionace glauca feeds mainly on red crab Pleuroncodes planipes Stimpson, 1860; squids Gonatus californiensis Young, 1972, Ancistrocheirus lesueurii (D'Orbigny, 1842), Haliphron atlanticus Steenstrup, 1861, and low proportion of fish teleosts as Merluccius productus (Ayres, 1855), Sardinops sp. Hubbs, 1929 and Scomber japonicus Houttuyn, 1872. We speculate that these prey could be involved as the second intermediate hosts of these cestodes, as in other members of these genera, although the life cycles of none are known.

  17. Arsenic content in groundwater from the southern part of the San Antonio-El Triunfo mining district, Baja California Sur, Mexico

    NASA Astrophysics Data System (ADS)

    Wurl, Jobst; Mendez-Rodriguez, Lía; Acosta-Vargas, Baudilio

    2014-10-01

    The San Antonio-El Triunfo mining district is located in a mountain region 60 km southeast of La Paz, the capital of the Mexican state of Baja California Sur. Mining activities, focused on gold and silver extraction, which began in the second half of the 18th century; the main activity took place between 1878 and 1911. The minerals were treated through the cyanide method, burned, and smelted. In effect between 800,000 and 1 million tons of mine waste materials were scattered in an area of approximately 350-400 km2. This area contains today several byproducts as a result from arsenopyrite oxidation, such as arsenolite (As2O3). The aim of this study was to analyze groundwater composition in order to define the actual concentrations of relevant parameters to detect ore mining contaminations, especially in respect to arsenic. In the autumn of 2010, 29 groundwater samples were obtained using flow-through bailer or down-hole pump methods, and a total of 37 variables were measured in each sample. Arsenic (dissolved) exceeded the values established by the World Health Organization (WHO, 2011) (0.01 mg/L) in 41% of the monitored sites. The maximum concentration of arsenic found in one observation well was 0.45 mg/L. Four water samples, which were characterized by elevated concentration of boron (max. conc. 9.5 mg/L), fluoride (max. conc. 3.25 mg/L) and alkaline pH values (>9), showed a composition typical for hydrothermal water. Because all four samples had arsenic concentration under 0.008 mg/L, we conclude that no significant impact of arsenic from hydrothermal fluids is found in the study area.

  18. Capillary electrophoresis finger print technique (CE-SSCP): an alternative tool for the monitoring activities of HAB species in Baja California Sur Costal.

    PubMed

    Herrera-Sepúlveda, Angélica; Hernandez-Saavedra, Norma Y; Medlin, Linda K; West, Nyree

    2013-10-01

    In Mexican waters, there is no a formal and well-established monitoring program of harmful algal blooms (HAB) events. Until now, most of the work has been focused on the characterization of organisms present in certain communities. Therefore, the development of new techniques for the rapid detection of HAB species is necessary. Capillary electrophoresis finger print technique (CE-SSCP) is a fingerprinting technique based on the identification of different conformers dependent of its base composition. This technique, coupled with capillary electrophoresis, has been used to compare and identify different conformers. The aim of this study was to determine if CE-SSCP analysis of ribosomal RNA (rRNA) gene fragments could be used for a rapid identification of toxic and harmful HAB species to improve monitoring activities along the coasts of Baja California Sur, Mexico.Three different highly variable regions of the 18S and 28S rRNA genes were chosen and their suitability for the discrimination of different dinoflagellate species was assessed by CE-SSCP.The CE-SSCP results obtained for the LSU D7 fragment has demonstrated that this technique with this gene region could be useful for the identification of the ten dinoflagellates species of different genera.We have shown that this method can be used to discriminate species and the next step will be to apply it to natural samples to achieve our goal of molecular monitoring for toxic algae in Mexican waters. This strategy will offer an option to improve an early warning system of HAB events for coastal BCS, allowing the possible implementation of mitigation strategies. A monitoring program of HAB species using molecular methods will permit the analysis of several samples in a short period of time, without the pressure of counting with a taxonomic expert in phytoplankton taxonomy. PMID:22744160

  19. Lignes directrices sur l’aiguillage des cas soupçonnés de cancer colorectal par un médecin de famille ou autre professionnel des soins primaires

    PubMed Central

    Del Giudice, M. Elisabeth; Vella, Emily T.; Hey, Amanda; Simunovic, Marko; Harris, William; Levitt, Cheryl

    2014-01-01

    Résumé Objectif Ces lignes directrices ont pour but d’aider les médecins de famille et les autres professionnels des soins primaires à reconnaître les caractéristiques qui devraient susciter leurs soupçons quant à la présence d’un cancer colorectal (CCR) chez leurs patients. Composition du comité Les membres du comité ont été choisis parmi les dirigeants régionaux des soins primaires au sein du Réseau provincial des soins primaires et de la lutte contre le cancer, les membres du Comité consultatif sur le dépistage du cancer colorectal de l’Ontario et les membres du Groupe sur le siège de la maladie, Cancer gastrointestinal, d’Action Cancer Ontario. Méthodes Ces lignes directrices sont le fruit d’une revue systématique et d’une synthèse des données probantes, ainsi que d’un examen formel par des intervenants canadiens pour valider la pertinence des recommandations. Rapport Des lignes directrices fondées sur des données probantes ont été élaborées pour améliorer la prise en charge des patients qui présentent des caractéristiques cliniques d’un CCR et ce, dans le contexte canadien. Conclusion Un équilibre judicieux entre une suspicion de CCR et le niveau de risque d’un tel cancer devrait favoriser une demande de consultation en temps opportun par les médecins de famille et les professionnels des soins primaires. Ces lignes directrices pourraient aussi orienter les décisions de demander une consultation à des programmes d’évaluation diagnostique du CCR.

  20. Effets de la taille finie du milieu non-linéaire sur le bruit quantique spatial généré par un oscillateur paramétrique optique confocal

    NASA Astrophysics Data System (ADS)

    Lopez, L.; Gatti, A.; Maitre, A.; Treps, N.; Gigan, S.; Fabre, C.

    2004-11-01

    Nous nous intéressons au comportement spatial des fluctuations quantiques à la sortie d'un oscillateur paramétrique optique dégénéré en modes transverses, sous le seuil. En vue de futures expériences, nous étudions les effets de la diffraction dans le milieu paramétrique sur le bruit quantique spatial. Nous montrons que l'on voit apparaître une aire de cohérence de taille finie pour les effets quantiques transverses.

  1. Halocoryza Alluaud 1919, sea-side beetles of the Indian, Atlantic (sensu lato), and Pacific Oceans: a generic synopsis and description of a remarkable new species from Baja California Sur, México (Coleoptera, Carabidae, Scaritini, Clivinina).

    PubMed

    Erwin, Terry L

    2011-01-01

    Information on the three previously described species of Halocoryza Alluaud is updated and a new species for the genus from Isla Carmen, Sea of Cortés, Baja California Sur, México is described. Halocoryza whiteheadianasp. n. was found at UV light on a beach of that island. This species does not fit the profile of the other three species, i.e., living on coralline beach sands, or in the Mangrove intertidal zone. Two alternative possibilities as to why this is so are suggested and a study plan for testing these possibilities is proposed.

  2. Formation et transformation de défauts ponctuels par insolation UV dans les diélectriques à base de silice: application à l'intégration de composants optiques sur fibre

    NASA Astrophysics Data System (ADS)

    Boukenter, A.; Goutaland, F.; Kuswanto, H.; Marin, E.; Meunier, J. P.; Ouerdane, Y.

    2003-06-01

    La présence dans les verres germanosilicates de défauts ponctuels résultants de défauts de liaisons interatomiques ou de stœchiométrie peut être à l'origine d'une modification photoinduite sous insolation UV de leur indice de réfraction. Cette modification est mise à profit pour induire une modulation périodique ou variable de l'indice permettant la réalisation de composants optiques intégrés sur fibre: filtres, miroirs, compensateurs de dispersion chromatique, étireur-compresseur d'impulsion optique.. .

  3. Les rivières et les sources de la Plaine du Cul-de-Sac: extrait du rapport sur les eaux souterraines de la Plaine du Cul-de-Sac

    USGS Publications Warehouse

    Taylor, George C.; Lemoine, Rémy C.

    1949-01-01

    Les principales rivières de la Plaine du Cul-de-Sac, la Rivière Grise ou Grande Rivière du Cul-de-Sac et la Rivière Blanche, prennent naissance sur le flanc Nord du Massif de la Selle à des altitudes de 1,300 à 1,800 mètres au dessus du niveau de la mer. Elles coulent à l’amont à travers des gorges profondes et sont éloignées de 9 Kms. dans la partie central de la bordure Sud de la plaine.

  4. Halocoryza Alluaud 1919, sea-side beetles of the Indian, Atlantic (sensu lato), and Pacific Oceans: a generic synopsis and description of a remarkable new species from Baja California Sur, México (Coleoptera, Carabidae, Scaritini, Clivinina)

    PubMed Central

    Erwin, Terry L.

    2011-01-01

    Abstract Information on the three previously described species of Halocoryza Alluaud is updated and a new species for the genus from Isla Carmen, Sea of Cortés, Baja California Sur, México is described. Halocoryza whiteheadiana sp. n. was found at UV light on a beach of that island. This species does not fit the profile of the other three species, i.e., living on coralline beach sands, or in the Mangrove intertidal zone. Two alternative possibilities as to why this is so are suggested and a study plan for testing these possibilities is proposed. PMID:21998544

  5. Active Crustal Deformation in the Area of San Carlos, Baja California Sur, Mexico as Shown by Data of Local Earthquake Sequences

    NASA Astrophysics Data System (ADS)

    Munguía, Luis; González-Escobar, Mario; Navarro, Miguel; Valdez, Tito; Mayer, Sergio; Aguirre, Alfredo; Wong, Victor; Luna, Manuel

    2015-12-01

    We analyzed earthquakes of sequences that occurred at different times near San Carlos, a town of approximately 5000 inhabitants. The seismic sequences happened during March-April 1989, October 2000-June 2001, and 5-15 February 2004 at about 200 km west of the Pacific-North America plate boundary. The strong shaking from initial earthquakes of the first two sequences prompted the installation of temporary seismic stations in the area. With data recorded by these stations, we found an earthquake distribution that is consistent with the northwest segment of the Santa Margarita fault. Both the focal depth, that seemed to increase in E-NE direction, and a composite fault-plane solution, obtained from polarity data of the small earthquakes, were also consistent with the main characteristics of that fault. We also found that our normal-faulting mechanism (east side down) was quite similar to centroid moment tensor solutions for earthquakes with M w 5.4 and 5.3 that occurred in the area in February 2004. It is likely, then, that these larger earthquakes also occurred along the Santa Margarita Fault. To get some insight into the regional stress pattern, we compared the above mechanisms with mechanisms reported for other earthquakes of the Pacific margin of Baja California Sur and the Gulf of California regions. We observed that focal mechanisms of the two regions have T axes of stress that plunge sub horizontally in E-NE average direction. The corresponding P axes have N-NW average trend, but for the Pacific earthquakes these axes plunge at angles that are ~35° larger than those for the Gulf earthquakes. These more vertically inclined P axes of compressive stress mean substantial oblique fault motions. The mixture of oblique and strike-slip components of fault motions, as the focal mechanisms show, confirms a transtensional stress regime for the region. Before this research, we knew little about the seismicity and styles of faulting in the area. Now we know that

  6. Corrosion influencée par les micro-organismes : influence du biofilm sur la corrosion des aciers, techniques et résultats recents

    NASA Astrophysics Data System (ADS)

    Feugeas, F.; Magnin, J. P.; Cornet, A.; Rameau, J. J.

    1997-03-01

    Microbiologically Influenced Corrosion (M.I.C.) studied since the beginning of this century, is responsible for the degradation of many metallic equipments. This study is a review of results dealing with M.I.C. on several types of steels as: carbon steels, stainless steels, welded steels and covered steels. M.I.C. occurs only in presence of a biofilm. The first part of this study describes chemical and physical factors involved in its development, technical methods for studying biofilms, and its contribution in the corrosion process. The second part is devoted to the study of M.I.C. cases linked with metal nature and different aqueous environments and the last part reviews the mainly mecanisms of biocorrosion. La Corrosion Influencée par les Micro-organismes (C.I.M.) ou biocorrosion, phénomène étudié depuis le début du siècle, est responsable de la dégradation d'un grand nombre d'ouvrages métalliques. Cette étude a pour but de faire le point des connaissances sur la corrosion influencée microbiologiquement de divers types d'aciers au carbone, d'aciers inoxydables, d'assemblages soudés et d'aciers revêtus. La C.I.M. n'apparaît qu'en présence d'un biofilm. La première partie de cette étude décrit les facteurs physico-chimiques impliqués dans la formation du biofilm, ces moyens d'études ainsi que son action dans le processus de biocorrosion. La seconde partie est consacrée à la description des cas de biocorrosion classés en fonction de la nature des métaux et des milieux avec lesquels ils sont en contact. La dernière partie de ce document passe en revue les principaux mécanismes de biocorrosion décrits.

  7. Influence des défauts de la structure du verre sur la résistance mécanique des fibres optiques

    NASA Astrophysics Data System (ADS)

    Chmel, A.; Baptizmanski, V. V.; Kharshak, A. A.

    1992-12-01

    For silica (pure and doped) optical fibers prepared from preforms irradiated by thermal neutrons and Ar^+ ions, the measurements of lifetime under transverse stress were carried out. It is found that the neutron bombardment leads to decrease of the lifetime and the strength of fiber while the ion implantation results in increasing of these parameters. The influence of particle irradiation on the glass strength is explained by the generation of structural defects which were observed by the infrared an Raman spectroscopy methods. The direction of the change of mechanical properties of fibers is determined by the type of defects and their distribution in the cross-section of fiber. Des préformes de fibres optiques de silice ont été exposées à un bombardement par des faisceaux de neutrons thermiques et d'ions Ar^+ à énergie de 40 keV afin d'engendrer des défauts de la structure respectivement dans le volume ou dans la couche superficielle des échantillons. Les fibres obtenues des préformes irradiées et non irradiées ont été mises en charge de flexion. On a déterminé leur temps de rupture sous diverses contraintes de traction sur la surface extérieure de la fibre en flexion. On a observé une diminution du temps de rupture des fibres après le bombardement neutronique et une augmentation après l'implantation ionique. L'analyse de la nature des défauts en faisant appel à la spectroscopie infrarouge et Raman a fait ressortir que l'irradiation aux ions entraînait essentiellement des liaisons chimiques dans une fine couche superficielle de l'échantillon alors que l'irradiation aux neutrons occasionnait une déformation des zones du réseau silicique dans toute la section de la préforme et de la fibre. L'amélioration de la résistance mécanique s'explique par une augmentation de la mobilité des éléments structuraux de la matrice de verre par suite d'une rupture partielle des liaisons chimiques et sa diminution par l'apparition de concentrateurs

  8. Impact du traitement antirétroviral sur le profil biologique des enfants VIH positifs suivis au Centre Hospitalier et Universitaire de Yaoundé au Cameroun

    PubMed Central

    Kalla, Ginette Claude Mireille; Assoumou, Marie-Claire Okomo; Kamgaing, Nelly; Monebenimp, Francisca; Mbopi-Keou, Francois-Xavier

    2015-01-01

    Introduction L'objectif de ce travail était d’évaluer l'impact du traitement antirétroviral sur le profil biologique des enfants VIH positifs suivis au Centre Hospitalier et Universitaire de Yaoundé au Cameroun. Méthodes Il s'agissait d'une étude rétrospective réalisée de Mai 2003 à Décembre 2012 au CHU de Yaoundé au Cameroun. Pour cette étude, nous avons obtenu une clairance éthique. Résultats L’âge moyen était de 54.02±46.34 mois. The sexe ratio était de 0.96 en faveur des garçons. Le diagnostic s’était fait tardivement (74.2%) ainsi que la mise sous traitement (83.3%). Seuls 36 des 116 enfants (31%) avait pu avoir un bilan biologique à l'initiation du traitement antirétroviral et six mois après l'initiation du traitement antirétroviral. Après six mois de traitement, nous avons enregistrés une augmentation significative des paramètres biologiques suivants: taux de glycémie de 0.09g/L (0.75-0.84; p= 0.007), pourcentage de CD4 chez les enfants de moins de 5 ans de 4.62% (20.12-24.75; p = 0.022), valeur absolue de CD4 chez les enfants de plus de 5 ans de 294 cellules/mm3 (151.18-445.18; p = 0.011), le rapport CD4/CD8 de 0.35 (0.55-0.90; p = 0.000). Enfin, après six mois de traitement, on enregistrait une baisse significative de la charge virale du VIH de 3.90 log (5.85-1.95; p = 0.006). Conclusion Il ressort de cette étude que la restauration immunitaire et la suppression virologique peuvent être obtenus après six mois de traitement antirétroviral. Cependant, des efforts doivent encore être faits en ce qui concerne la prise en charge du suivi biologique, gage d'un bon suivi thérapeutique au Cameroun. PMID:26113902

  9. Prise en compte de l'anisotropie des collisions ion-atome sur le transport des ions par simulation de Monte-Carlo

    NASA Astrophysics Data System (ADS)

    Hennad, A.; Eichwald, O.; Yousfi, M.; Lamrous, O.

    1997-09-01

    This paper is devoted to the determination of the differential and integral collision cross sections needed for the calculation of the transport coefficient of ions in weakly ionized gases. In the case of Ar^+/Ar system and for energy interval varying up to 100 eV, the cross sections are obtained from the interaction potential of polarization for low energies and of Lennard-Jones for higher energies. The calculation method of the collision cross sections based on the classical mechanics has been first validated from comparisons of measured and calculated differential cross sections. Then, these cross sections have been used in a Monte-Carlo code for simulation of the transport of Ar^+ ions in Ar gas at room temperature (300 K). The obtained transport coefficients (ion mobility, drift velocity and diffusion coefficient) are in good agreement with the drift tube measurements given in the literature thus confirming the validity of the method of collision cross section calculation. Cet article est consacré à la détermination des sections efficaces différentielles et intégrales ion-atome nécessaires au calcul des coefficients de transport des ions dans les gaz faiblement ionisés. Dans le cas du système Ar^+/Ar et pour des intervalles d'énergie allant jusqu'à quelques dizaines d'eV, les sections efficaces sont obtenues à partir des potentiels d'interaction de polarisation pour les faibles énergies et de Lennard-Jones pour les énergies plus élevées. La méthode de calcul des sections efficaces basée sur la mécanique classique a d'abord été validée par comparaison des sections efficaces différentielles mesurées et calculées. Ensuite, ces sections efficaces ont été utilisées dans un code de simulation statistique de Monte-Carlo du transport des ions Ar^+ dans l'Argon à la température ambiante (300 K). Les coefficients de transport (vitesse de dérive, mobilité ionique et coefficient de diffusion) obtenus sont en bon accord avec les mesures de

  10. Active Crustal Deformation in the Area of San Carlos, Baja California Sur, Mexico as Shown by Data of Local Earthquake Sequences

    NASA Astrophysics Data System (ADS)

    Munguía, Luis; González-Escobar, Mario; Navarro, Miguel; Valdez, Tito; Mayer, Sergio; Aguirre, Alfredo; Wong, Victor; Luna, Manuel

    2016-10-01

    We analyzed earthquakes of sequences that occurred at different times near San Carlos, a town of approximately 5000 inhabitants. The seismic sequences happened during March-April 1989, October 2000-June 2001, and 5-15 February 2004 at about 200 km west of the Pacific-North America plate boundary. The strong shaking from initial earthquakes of the first two sequences prompted the installation of temporary seismic stations in the area. With data recorded by these stations, we found an earthquake distribution that is consistent with the northwest segment of the Santa Margarita fault. Both the focal depth, that seemed to increase in E-NE direction, and a composite fault-plane solution, obtained from polarity data of the small earthquakes, were also consistent with the main characteristics of that fault. We also found that our normal-faulting mechanism (east side down) was quite similar to centroid moment tensor solutions for earthquakes with M w 5.4 and 5.3 that occurred in the area in February 2004. It is likely, then, that these larger earthquakes also occurred along the Santa Margarita Fault. To get some insight into the regional stress pattern, we compared the above mechanisms with mechanisms reported for other earthquakes of the Pacific margin of Baja California Sur and the Gulf of California regions. We observed that focal mechanisms of the two regions have T axes of stress that plunge sub horizontally in E-NE average direction. The corresponding P axes have N-NW average trend, but for the Pacific earthquakes these axes plunge at angles that are ~35° larger than those for the Gulf earthquakes. These more vertically inclined P axes of compressive stress mean substantial oblique fault motions. The mixture of oblique and strike-slip components of fault motions, as the focal mechanisms show, confirms a transtensional stress regime for the region. Before this research, we knew little about the seismicity and styles of faulting in the area. Now we know that

  11. Statistical properties and time-frequency analysis of temperature, salinity and turbidity measured by the MAREL Carnot station in the coastal waters of Boulogne-sur-Mer (France)

    NASA Astrophysics Data System (ADS)

    Kbaier Ben Ismail, Dhouha; Lazure, Pascal; Puillat, Ingrid

    2016-10-01

    In marine sciences, many fields display high variability over a large range of spatial and temporal scales, from seconds to thousands of years. The longer recorded time series, with an increasing sampling frequency, in this field are often nonlinear, nonstationary, multiscale and noisy. Their analysis faces new challenges and thus requires the implementation of adequate and specific methods. The objective of this paper is to highlight time series analysis methods already applied in econometrics, signal processing, health, etc. to the environmental marine domain, assess advantages and inconvenients and compare classical techniques with more recent ones. Temperature, turbidity and salinity are important quantities for ecosystem studies. The authors here consider the fluctuations of sea level, salinity, turbidity and temperature recorded from the MAREL Carnot system of Boulogne-sur-Mer (France), which is a moored buoy equipped with physico-chemical measuring devices, working in continuous and autonomous conditions. In order to perform adequate statistical and spectral analyses, it is necessary to know the nature of the considered time series. For this purpose, the stationarity of the series and the occurrence of unit-root are addressed with the Augmented-Dickey Fuller tests. As an example, the harmonic analysis is not relevant for temperature, turbidity and salinity due to the nonstationary condition, except for the nearly stationary sea level datasets. In order to consider the dominant frequencies associated to the dynamics, the large number of data provided by the sensors should enable the estimation of Fourier spectral analysis. Different power spectra show a complex variability and reveal an influence of environmental factors such as tides. However, the previous classical spectral analysis, namely the Blackman-Tukey method, requires not only linear and stationary data but also evenly-spaced data. Interpolating the time series introduces numerous artifacts to the

  12. Variabilidad de la Estación de Crecimiento en la Región Sur de Tamaulipas en condiciones climaticas actuales y futuras.

    NASA Astrophysics Data System (ADS)

    Medina-Barrios, M.; Conde-Alvarez, C.; Gay-Garcia, C.

    2007-05-01

    El impacto de la variabilidad y cambio climáticos, afectan el potencial agrícola de la Región Sur de Tamaulipas. Además de los cambios estacionales, bajos rendimientos agrícolas, el manejo de los cultivos y las políticas locales de producción, existe la incertidumbre del mercado regional para los pequeños y grandes productores. La diversificación agrícola ha sido una alternativa para enfrentar las condiciones imperantes en esta región. Pero ésta ha provocado la fragmentación territorial, por lo que sólo algunos productores logran competir en un mercado nacional. Existe una preocupación generalizada por buscar soluciones que permitan que la población que es afectada por la inseguridad de la producción agrícola y económica, pueda adaptarse a las variaciones climáticas que afectan el proceso productivo. La seguridad alimentaría queda sujeta a la fluctuación de las importaciones para los sectores básicos y a las estrategias mercantiles de empresas trasnacionales. La percepción local sugiere un número creciente de eventos climatológicos extremos, constantes y severos en los últimos 20 años, con el aumento creciente de pérdidas económicas. El análisis se centra en la disponibilidad de agua, agregándose un aspecto de capital importancia como es la variabilidad interanual de la lluvia, que condiciona muy fuertemente el riesgo agrícola en el trópico seco, siendo ésta la que determina el momento de inicio de la estación favorable para el crecimiento y su duración. En este trabajo se han obtenido modelos de la distribución espacial de la precipitación y temperaturas, para el escenario base 1961-1990, el escenario actual 1971-2000, para algunos años El Niño y La Niña, así como para los escenarios de Cambio Climático HADLEY, ECHAM y GFDL, con escenarios A2 y B2, para las décadas de los 20s y 50s, para establecer el inicio y duración de la Estación de Crecimiento, utilizando Sistemas de Información Geográfica (ArcView). Estos

  13. Late Pleistocene-Holocene Faulting History Along the Northern El Carrizal Fault, Baja California Sur, Mexico: Earthquake Recurrence at a Persistently Active Rifted Margin

    NASA Astrophysics Data System (ADS)

    Maloney, S. J.; Umhoefer, P. J.; Arrowsmith, J. R.; Gutiérrez, G. M.; Santillanez, A. U.; Rittenour, T. R.

    2007-12-01

    The El Carrizal fault is a NW striking, east dipping normal fault located 25 km west of the city of La Paz, Baja California Sur, Mexico and is the westernmost bounding fault of the gulf-margin system at this latitude. The fault is ~70 km long onshore and ~50 km long offshore to the north in La Paz Bay. As many as three Quaternary geomorphic surfaces formed on the footwall and were identified on the basis of mapping and topographic profiling. In the north, the El Carrizal fault splays into multiple strands and exhibits a pattern of alternating N-S and NW-trending segments. Results from geologic mapping, paleoseismic investigations, and preliminary optically stimulated luminescence (OSL) geochronology provide some of the first numerical constraints on late Pleistocene-Holocene faulting along the El Carrizal fault. A 20 m long, 2-3 m deep trench (Trench 28) was excavated across the fault 23 km south of La Paz Bay. The trench was photographed, hand logged, and sampled for OSL dating. The trench revealed a succession of fluvial and channel deposits of sands, gravels, and cobbles. The main fault zone is manifested by a 0.5 m thick wedge-shaped deposit that consists of silty-sand and also contains rotated blocks of caliche- cemented gravels. Preliminary OSL ages from a silty-sand unit offset 2 m by the fault average latest Pleistocene. A trench 4 km south of Trench 28 (Cuadradito Trench) was also documented and sampled for OSL analysis. Preliminary OSL ages from a fluvial sand unit deposited against faulted bedrock range from mid to late Holocene. Sedimentary comparisons and surficial mapping suggest that the Holocene unit at Cuadradito Trench may be correlative to sediment that overlies faulted units from Trench 28. Such a correlation would constrain the timing of the 2 m offset at Trench 28 to be between latest Pleistocene and mid Holocene. A quarry 10 km north of Trench 28 exposes Quaternary sand and gravels buttressed against a 5-10 m wide bedrock shear zone. Here

  14. Revue systématique sur la contribution des femmes distributeurs communautaires dans la lutte contre l'onchocercose en Afrique sub-saharienne

    PubMed Central

    Vouking, Marius Zambou; Tadenfok, Carine Nouboudem; Evina, Christine Danielle; Nsangou, Moustapha; Bonono, Cécile-Renée; Yondo, David

    2014-01-01

    un rôle important dans la lutte contre l'onchocercose. Toutefois, des préoccupations subsistent quant aux considérations de mise en œuvre en faveur dudit rôle. Les conclusions ont aussi des implications pour la recherche future sur l’élaboration d'un cadre d’évaluation et de comparaison des interventions impliquant les DCs hommes et femmes. PMID:25883745

  15. Lignes directrices sur l’aiguillage des cas soupçonnés de cancer du poumon par un médecin de famille ou autre professionnel des soins primaires

    PubMed Central

    Del Giudice, M. Elisabeth; Young, Sheila-Mae; Vella, Emily T.; Ash, Marla; Bansal, Praveen; Robinson, Andrew; Skrastins, Roland; Ung, Yee; Zeldin, Robert; Levitt, Cheryl

    2014-01-01

    Résumé Objectif Les présentes lignes directrices visent à aider les médecins de famille et autres généralistes à reconnaître les manifestations cliniques devant éveiller les soupçons quant à la présence d’un cancer du poumon chez les patients. Composition du comité Les membres du comité ont été choisis parmi les leaders régionaux en soins primaires du Réseau provincial des soins primaires et de la lutte contre le cancer d’Action Cancer Ontario et parmi les membres du Groupe sur le siège de la maladie, Cancer du poumon d’Action Cancer Ontario. Méthodes Les présentes lignes directrices sont le fruit d’une revue systématique des données probantes, d’une synthèse des données et d’un examen externe formel effectué par des intervenants canadiens qui ont validé la pertinence des recommandations. Rapport Ces lignes directrices fondées sur des données probantes ont été formulées pour améliorer la prise en charge en contexte canadien des patients qui présentent des manifestations cliniques du cancer du poumon. Conclusion Le dépistage et l’aiguillage précoces des patients atteints de cancer du poumon pourraient en fin de compte aider à réduire les morbidités et mortalités liées au cancer. Ces lignes directrices pourraient aussi s’avérer utiles dans la mise sur pied de programmes de diagnostic du cancer du poumon et pour aider les décideurs à veiller à ce que les ressources appropriées soient en place.

  16. Low risk of nevirapine resistance mutations in the prevention of mother-to-child transmission of HIV-1: Agence Nationale de Recherches sur le SIDA Ditrame Plus, Abidjan, Cote d'Ivoire.

    PubMed

    Chaix, Marie-Laure; Ekouevi, Didier Koumavi; Rouet, Francois; Tonwe-Gold, Besigin; Viho, Ida; Bequet, Laurence; Peytavin, Gilles; Toure, Hassane; Menan, Herve; Leroy, Valeriane; Dabis, Francois; Rouzioux, Christine

    2006-02-15

    The frequency of resistance mutations was estimated in the cohort of Agence Nationale de Recherches sur le SIDA Ditrame Plus, a study that evaluated the combination of short-course zidovudine (ZDV) plus lamivudine (3TC) and single-dose nevirapine (SD-NVP) followed by 3 days of postpartum ZDV plus 3TC for the prevention of mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1). The frequency with which resistance mutations were detected in mothers at week 4 postpartum was 1.14% (95% confidence interval [CI], 0.03%-6.17%) for NVP and 8.33% (95% CI, 3.66%-15.76%) for 3TC. In multivariate analysis, 3TC resistance was associated with a longer duration of ZDV plus 3TC prepartum prophylaxis (P=.009). This regimen, which is feasible in resource-limited settings, prevents most peripartum HIV-1 transmission and minimizes the development of NVP resistance.

  17. Répercussions psychosociales de la drépanocytose sur les parents d'enfants vivant à Kinshasa, République Démocratique du Congo: une étude qualitative

    PubMed Central

    Luboya, Evariste; Tshilonda, Jean-Christophe Bukasa; Ekila, Mathilde Bothale; Aloni, Michel Ntetani

    2014-01-01

    Introduction L'insuffisance des moyens de base pour le dépistage et la prise en charge de la socioculturel Africain. D'où la nécessité de réaliser un travail de mise en sens du vécu et des émotions en vue d'information et de soutien psychologique des familles des drépanocytaires. Cette étude a eu pour objectif d'identifier la nature des répercussions psychosociales de la drépanocytose chez les parents et chez les malades. Méthodes Une approche qualitative a été utilisée. Des entretiens ont été menés auprès des parents et des patients drépanocytaires. Nos résultats ont fait l'objet d'une analyse thématique articulée sur les circonstances de découvertes de la maladie, les répercussions de la maladie et la perception de la prise en charge. Résultats Nos interviews ont montré des répercussions psychosociales importantes chez les parents d'enfants drépanocytaires et de stigmatisation des difficultés d'insertion sociale et scolaire pour les enfants drépanocytaires. Ces derniers sont les grands oubliés des récits de parents. La prise en charge est uniquement médicale avec des ressources très limitées et aucun accompagnement psychologique de la famille n'est assuré. Conclusion La prise en charge de cette maladie nécessite la mise en place d'une politique de prise en charge basée sur une approche globale de la maladie. PMID:25574334

  18. Evaluation of analgesic activities of tremetone derivatives isolated from the Chilean altiplano medicine Parastrephia lepidophylla.

    PubMed

    Benites, Julio; Gutierrez, Eunices; López, Jóse; Rojas, Mauricio; Rojo, Leonel; Costa, Maria do Céu; Vinardell, Maria Pilar; Calderon, Pedro Buc

    2012-05-01

    Parastrephia lepidophylla, family Asteraceae, has ancient use in traditional medicine in the region of Tarapacá, Chile. Bioguided fractionation of extracts of this plant was undertaken in the search for compounds with analgesic and antioxidant activity. Two benzofuran derivatives were isolated as the major components of this plant, identified as tremetone 1 and methoxytremetone 6. Remarkably, neither of these showed antioxidant activity, but tremetone 1 exhibited a morphine-like analgesic property. Reduction of this analgesic effect by naloxone suggests a direct effect on opiate receptors as a possible signaling pathway. However, both the low diffusion across lipid membranes (PAMPA assay) and the lipophilicity (Log P) shown by tremetone 1 make elusive the mechanism explaining its induced analgesia.

  19. Indoor metallic pollution related to mining activity in the Bolivian Altiplano.

    PubMed

    Fontúrbel, Francisco E; Barbieri, Enio; Herbas, Cristian; Barbieri, Flavia L; Gardon, Jacques

    2011-10-01

    The environmental pollution associated with mining and metallurgical activities reaches its greatest extent in several Andean cities and villages. Many locations in this area have accumulated through centuries a large amount of mining wastes, often disregarding the magnitude of this situation. However, in these naturally mineralized regions, there is little information available stating the exact role of mining and metallurgical industries in urban pollution. In this study, we demonstrated that the various metallic elements present in indoor dust (As, Cd, Cu, Pb, Sb, Sn, Zn) had a common origin and this contamination was increased by the proximity to the mines. Lead dust concentration was found at concerning levels for public health. In addition, wrong behaviors such as carrying mining workwear home contributed to this indoor dust pollution. Consequently, the constant exposure of the population could represent a potential health hazard for vulnerable groups, especially children.

  20. Getting the Mixture Right: Nonformal Education through Community Radio in the Bolivian Altiplano.

    ERIC Educational Resources Information Center

    Burke, Richard C.

    1987-01-01

    Concentrates on the work of Community Education through Radio (ECORA), a Bolivian organization that planned and implemented the nonformal education component of a project that included school construction, teacher training, bilingual education, and administrative reforms within the Ministry of Education and Culture. (JOW)

  1. Ethnobotany and exchange of traditional medicines on the Southern Bolivian Altiplano.

    PubMed

    Sikkink, L

    2000-01-01

    Research conducted on the collection, use, and vending of traditional medicines by rural Bolivian women indicates that it is an important economic activity as well as having a place in the health system of high altitude inhabitants. The aim of this paper is to discuss the intersection of an approach that focuses on the exchange of traditional medicines with an ethnobotanical perspective that considers the medicines themselves. Women are the focus of this intersection because they are central to the enterprise of collecting and selling traditional medicines, which is an expanding business opportunity due in part to demands by urban consumers. In moving toward an ethnobotanical analysis of the plants themselves, it is important to consider how this focus will enhance our understanding of the marketing and use of traditional medicines and women's roles therein, but researchers must also understand the problems related to the potential use of ethnobotanical data to create new pharmaceuticals.

  2. Making a case for breeding frost tolerant potatoes adapted to Andean Highlands especially the Altiplano

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although cultivated potatoes are sensitive to mild frost (severely damaged at air temperatures below -2 or -3 C) limited progress has been made in developing frost hardy cultivars. This may be due to the fact that most potato crop grown in North America and Europe has minimal risk to be subjected to...

  3. Caracterisation, modelisation et validation du transfert radiatif d'atmospheres non standard; impact sur les corrections atmospheriques d'images de teledetection

    NASA Astrophysics Data System (ADS)

    Zidane, Shems

    This study is based on data acquired with an airborne multi-altitude sensor on July 2004 during a nonstandard atmospheric event in the region of Saint-Jean-sur-Richelieu, Quebec. By non-standard atmospheric event we mean an aerosol atmosphere that does not obey the typical monotonic, scale height variation employed in virtually all atmospheric correction codes. The surfaces imaged during this field campaign included a diverse variety of targets : agricultural land, water bodies, urban areas and forests. The multi-altitude approach employed in this campaign allowed us to better understand the altitude dependent influence of the atmosphere over the array of ground targets and thus to better characterize the perturbation induced by a non-standard (smoke) plume. The transformation of the apparent radiance at 3 different altitudes into apparent reflectance and the insertion of the plume optics into an atmospheric correction model permitted an atmospheric correction of the apparent reflectance at the two higher altitudes. The results showed consistency with the apparent validation reflectances derived from the lowest altitude radiances. This approach effectively confirmed the accuracy of our non-standard atmospheric correction approach. This test was particularly relevant at the highest altitude of 3.17 km : the apparent reflectances at this altitude were above most of the plume and therefore represented a good test of our ability to adequately correct for the influence of the perturbation. Standard atmospheric disturbances are obviously taken into account in most atmospheric correction models, but these are based on monotonically decreasing aerosol variations with increasing altitude. When the atmospheric radiation is affected by a plume or a local, non-standard pollution event, one must adapt the existing models to the radiative transfer constraints of the local perturbation and to the reality of the measurable parameters available for ingestion into the model. The

  4. Détermination expérimentale de la résistance thermique d'interface d'un dépôt métallique submicronique sur son substrat

    NASA Astrophysics Data System (ADS)

    Hmina, N.; Scudeller, Y.

    1995-06-01

    Mechanisms of deposition and adhesion of a solid film are closely related to the physical and chemical properties of the substrate. Experimental measurement of thermal contact resistance gives new informations by characterizing the presence of impurities, fissures and cracks due to the elaboration process. An original method of thermal contact resistance measurement of a submicronic film on a dielectric substrate is presented. The measurement consists in analysing the very beginning of the cooling phase of the film, which follow the heating by a short laser pulse (≈ 20 ns). Temperature detection is obtained by electrical resistance measurement of the film. Detection with a high bandwidth (25 MHz) ensure a good restitution of the signal, which is numerically filtered in order to be analyzed. A very small thermal contact resistance compromise between 10^{-8} and 10^{-6} m^2K/W is measured if the temperature detection is operated before one microsecond. The principle of the method and the experimental arrangement are described. The sensitivity is analyzed. Experimental results are obtained on thin film of 200 to 600 nm thickness (pulverized copper) on glass substrate. The thermal contact resistance of about 10^{-7} m^2K/W have been identified with an uncertainty of about 30%. Les mécanismes de croissance et l'adhésion d'un dépôt sont étroitement liés aux propriétés physiques et chimiques superficielles du substrat. La détermination de la résistance thermique d'interface peut mettre en lumière certains aspects de ce couplage en caractérisant la présence d'impuretés, de fissures ou de décollements liés au procédé d'élaboration. Une méthode de mesure originale de la résistance d'interface entre un dépôt submicronique et un substrat diélectrique est présentée. Elle est fondée sur l'analyse des premiers instants de refroidissement du dépôt consécutif à l'échauffement produit par une impulsion laser. L'échauffement est obtenu par la mesure

  5. Révision systématique des effets de la fréquence des repas en famille sur les résultats psychosociaux chez les jeunes

    PubMed Central

    Harrison, Megan E.; Norris, Mark L.; Obeid, Nicole; Fu, Maeghan; Weinstangel, Hannah; Sampson, Margaret

    2015-01-01

    Résumé Objectif Effectuer une révision systématique des effets de repas en famille fréquents sur les résultats psychosociaux chez les enfants et les adolescents et examiner s’il existe des différences dans les résultats selon le sexe. Sources des données Des études ont été cernées à la suite d’une recherche dans MEDLINE (de 1948 à la dernière semaine de juin 2011) et dans PsycINFO (de 1806 à la première semaine de juillet 2011) à l’aide de l’interface Ovide. Les expressions et mots clés MeSH utilisés seuls ou en combinaisons étaient les suivants : family, meal, food intake, nutrition, diets, body weight, adolescent attitudes, eating behaviour, feeding behaviour et eating disorders. Les bibliographies des articles jugés pertinents ont aussi été passées en revus. Sélection des études La recherche initiale a produit 1783 articles. Pour être incluses dans l’analyse, les études devaient répondre aux critères suivants : être publiées en anglais dans une revue révisée par des pairs; porter sur des enfants ou des adolescents; traiter de l’influence des repas en famille sur les paramètres psychosociaux (p. ex. consommation de drogues et autres substances, troubles de l’alimentation, dépression) chez les enfants ou les adolescents; avoir une conception d’étude appropriée, notamment des méthodes statistiques acceptables pour l’analyse des paramètres. Quatorze articles satisfaisaient aux critères d’inclusion. Deux examinateurs indépendants ont étudié et analysé les articles. Synthèse Dans l’ensemble, les résultats font valoir que la fréquence des repas en famille est inversement proportionnelle aux troubles de l’alimentation, à la consommation d’alcool et de drogues, aux comportements violents, aux sentiments de dépression ou aux pensées suicidaires chez les adolescents. Il existe une relation positive entre de fréquents repas en famille, une bonne estime de soi et la réussite scolaire. Les

  6. Une étude rétrospective sur l'incidence de l'insuffisance rénale chronique dans le service de Médecine Interne et Néphrologie du Centre Hospitalier Universitaire d'Antananarivo

    PubMed Central

    Ramilitiana, Benja; Ranivoharisoa, Eliane Mikkelsen; Dodo, Mihary; Razafimandimby, Evanirina; Randriamarotia, Willy Franck

    2016-01-01

    L'insuffisance rénale chronique est un problème de santé publique au niveau mondial. Dans les pays développés, cette affection survient essentiellement chez les sujets âgés, mais en Afrique, elle s'installe plutôt chez les sujets jeunes actifs. C'est une affection de lourde prise en charge dans un pays à faible revenu à cause de ses coûts. Notre but est de décrire les aspects épidémiologiques des nouveaux cas d'insuffisance rénale chronique à Madagascar. Il s'agit d'une étude rétrospective descriptive de 3 ans partant du 1er janvier 2007 au 31 décembre 2009 dans le service de Médecine Interne et Néphrologie du Centre Hospitalier Universitaire d'Antananarivo portant sur 239 patients diagnostiqués comme une insuffisance rénale chronique. L'incidence était de 8,51% parmi les patients hospitalisés dans le service. L’âge moyen des patients était de 45,4 ans avec des extrêmes de 16 et 82 ans et un sex-ratio de 1,46. Le principal antécédent était l'hypertension artérielle (59,8%). L'insuffisance rénale chronique était terminale dans 75,31% des cas (n=180). Les causes de l'insuffisance rénale chronique étaient dominées par la glomérulonéphrite chronique (40,1%), la néphroangiosclérose (35,5%). L'hémodialyse était réalisée chez 3 patients (1,26%), aucun patient n’était pas programmé pour une greffe rénale. Le taux de mortalité dans le service était de 28,87%. L'insuffisance rénale chronique est une maladie de pronostic redoutable et handicapante qui affecte les sujets jeunes à Madagascar. Son traitement reste inaccessible dans la majorité des patients. L'accent doit donc être mis principalement sur la prévention notamment une bonne prise en charge précoce des infections, de l'hypertension artérielle et du diabète pour réduire ses impacts négatifs sur la santé communautaire et publique. Le projet de la transplantation rénale - donneur vivant, traitement efficace et moins coûteux par rapport à l

  7. Morbidité et mortalité des nouveau-nés hospitalisés sur 10 années à la Clinique El Fateh-Suka (Ouagadougou, Burkina Faso)

    PubMed Central

    Nagalo, Kisito; Dao, Fousséni; Tall, François Housséini; Yé, Diarra

    2013-01-01

    Introduction La mortalité néonatale demeure un problème majeur de santé publique dans les pays en développement. Notre étude avait pour but de déterminer la morbidité et la mortalité des nouveau-nés à Ouagadougou, Burkina Faso. Méthodes Une étude rétrospective sur 10 années a permis d'inclure tous les nouveau-nés admis dans l'Unité de Néonatologie de la Clinique El Fateh-Suka. Résultats Au total, 697 nouveau-nés étaient hospitalisés sur la période d'étude. Les principaux diagnostics étaient les infections néonatales (23.5%), les anomalies liées à la durée de la gestation et à la croissance du fætus (17.9%) et le paludisme congénital (15.1%). Les 91 (13.1%) décès étaient dus aux anomalies liées à la durée de la grossesse et à la croissance du fætus (46.1%), à l'hypoxie intra-utérine et à l'asphyxie obstétricale (20,9%) et aux infections néonatales (17.6%). Ces décès survenaient dans 81.3% dans les 72 heures, dans 93.4% des cas dans la première semaine d'hospitalisation. Le facteur de risque associé à ces décès était la voie basse d'accouchement (p = 0.02). Conclusion Cette étude a identifié des pathologies évitables déjà décrites comme les principales causes d'hospitalisations et de décès néonatals. La voie basse d'accouchement était le facteur de risque associé à ces décès, ce qui n'avait pas encore été rapporté. Les efforts pour améliorer la qualité des services de soins périnatals doivent être intensifiés afin de réduire la mortalité néonatale dans les pays en développement. PMID:23785558

  8. The Application of Support Vector Machine (svm) Using Cielab Color Model, Color Intensity and Color Constancy as Features for Ortho Image Classification of Benthic Habitats in Hinatuan, Surigao del Sur, Philippines

    NASA Astrophysics Data System (ADS)

    Cubillas, J. E.; Japitana, M.

    2016-06-01

    This study demonstrates the application of CIELAB, Color intensity, and One Dimensional Scalar Constancy as features for image recognition and classifying benthic habitats in an image with the coastal areas of Hinatuan, Surigao Del Sur, Philippines as the study area. The study area is composed of four datasets, namely: (a) Blk66L005, (b) Blk66L021, (c) Blk66L024, and (d) Blk66L0114. SVM optimization was performed in Matlab® software with the help of Parallel Computing Toolbox to hasten the SVM computing speed. The image used for collecting samples for SVM procedure was Blk66L0114 in which a total of 134,516 sample objects of mangrove, possible coral existence with rocks, sand, sea, fish pens and sea grasses were collected and processed. The collected samples were then used as training sets for the supervised learning algorithm and for the creation of class definitions. The learned hyper-planes separating one class from another in the multi-dimensional feature space can be thought of as a super feature which will then be used in developing the C (classifier) rule set in eCognition® software. The classification results of the sampling site yielded an accuracy of 98.85% which confirms the reliability of remote sensing techniques and analysis employed to orthophotos like the CIELAB, Color Intensity and One dimensional scalar constancy and the use of SVM classification algorithm in classifying benthic habitats.

  9. Bronchiolitis obliterans organizing pneumonia syndrome primed by radiation therapy to the breast. The Groupe d'Etudes et de Recherche sur les Maladies Orphelines Pulmonaires (GERM"O"P)

    PubMed

    Crestani, B; Valeyre, D; Roden, S; Wallaert, B; Dalphin, J C; Cordier, J F

    1998-12-01

    Reports of bronchiolitis obliterans organizing pneumonia (BOOP) occurring in women after radiation therapy for breast cancer have suggested that radiation to the lung could participate in the development of BOOP. We now describe the clinical, radiographic, functional, and bronchoalveolar lavage characteristics of this syndrome in a series of 15 patients reported to the Groupe d'Etudes et de Recherche sur les Maladies "Orphelines" Pulmonaires (GERM"O"P) in France. All 15 women (60 +/- 6 yr of age) fulfilled the following inclusion criteria: (1) radiation therapy to the breast within 12 mo, (2) general and/or respiratory symptoms lasting for at least 2 wk, (3) lung infiltrates outside the radiation port, and (4) no specific cause. The patients presented with fever, nonproductive cough, mild dyspnea, and peripheral alveolar opacities on chest radiograph with a characteristic migratory pattern. In five patients, BOOP was found at lung pathologic analysis. In all the patients dramatic improvement was obtained with corticosteroids, but relapses occurred in 12 patients while tapering or after stopping corticosteroids. This report demonstrates that a characteristic BOOP syndrome may occur after radiation therapy to the breast, including tangential radiation to the lung, thus suggesting that radiation therapy may prime the development of BOOP.

  10. Sources et impacts potentiels des micropolluants chimiques sur un écosystème littoral exploité: l'exemple des côtes des Charente-Maritime

    NASA Astrophysics Data System (ADS)

    Miramand, P.; Guyot, T.; Pigeot, J.

    2003-06-01

    Le littoral picto-charentais est une zone à fortes activités économiques liées à l'aquaculture, à la pêche et au tourisme. Toutes ces activités demandent une très bonne qualité des eaux et de l'environnement en général. Or, cette zone littorale est soumise à de nombreux apports de micropolluants: métaux lourds, phytosanitaires, hydrocarbures, organochlorés.... Les sources en sont nombreuses: apports fluviatiles et atmosphériques, rejets diffus et rejets directs. Les risques dus à cette pollution sont multiples que ce soit au niveau dcs organismes, au niveau des écosystèmes ou des consommateurs. De ce fait, les contaminants majeurs (métaux lourds, organochlorés. hydrocarbures aromatiques polycycliques) et leurs impacts éventuels sur les écosystèmes font l'objet de veille environnementale (réseaux de surveillance ou d'observatoires de l'environnement) et de mesures de prévention se traduisant par la définition de normes de rejets ou de contamination décidées à l'échelle européenne.

  11. Synchrotron X-ray microanalysis and imaging of synthetic biological calcium carbonate in comparison with archaeological samples originating from the Large cave of Arcy-sur-Cure (28000-24500 BP, Yonne, France).

    PubMed

    Chalmin, Emilie; Reiche, Ina

    2013-12-01

    Biosynthetic calcite samples were investigated using combined synchrotron X-ray microspectroscopy mapping. These samples were prepared with bacteria isolated from the Large cave of Arcy-sur-Cure in which prehistoric figures are masked by an opaque calcite layer. The biotic or abiotic origin of this layer is the issue of the present work. As previously known, a large community of bacteria may be involved in the CaCO3 formation in caves. A mixture of calcite/vaterite was obtained from bacteria isolated from the cave. Therefore, we can offer conclusions on their calcifying capability. The rare presence of vaterite in cave environments may be treated as a marker of biotic carbonate formations. Moreover, an amorphous calcium phosphate phase was present in the form of a calcite/vaterite mixture in the biotic model samples. This mixture of phases could be used as a tracer of the biotic process of CaCO3 formation. These biotic tracer phases were not identified using the applied analytical methods in the natural samples taken from the opaque calcite layers that covered the prehistoric figures of the Large cave. In this case, based on the obtained results, the biotic calcite formation process is likely to be considered as an undetectable effect at minimum.

  12. La valgisation tibiale par addition d'ouverture interne avec comblement cimenté dans la gonarthrose fémorotibiale médiale sur 38 genu-varum

    PubMed Central

    Mahraoui, Mohamed Amine; Abouchane, Merouane; El Andaloussi, Yassir; Haddoun, Ahmed Reda; Nechad, Mohamed

    2015-01-01

    Le genu varum sur gonarthrose fémorotibiale interne est une pathologie en nette recrudescence dans notre pays, affectant spécialement les femmes âgées et hautement invalidante chez l'adulte jeune; Souvent, elle pose un problème d'indication et de choix thérapeutique d'ordre multifactoriel. L'ostéotomie tibiale de valgisation par ouverture interne est une technique de référence, bien connue depuis longtemps et d'efficacité validée à court, moyen et long terme, et constitue un outil thérapeutique de choix et d'apport marqué, notamment pour les sujets jeunes actifs avec gonarthrose débutante. Par ailleurs, cette technique peut voir ses indications s’élargir au dépend de l’âge et du stade évolutif. Le but de notre travail est d’évaluer les résultats anatomiques et fonctionnels de notre technique d'ostéotomie tibiale de valgisation avec comblement cimenté chez l'adulte jeune de plus de 40 ans et de préciser les facteurs pronostiques qui régissent ces résultats. Ce travail propose à travers une étude rétrospectivement menée à propos de 38 genoux opérés chez 28 patients de dresser un bilan épidémiologique, clinique, et radiologique afin d’évaluer les résultats anatomiques et fonctionnels immédiats et à distance avec un recul minimum de 2 ans, de l'ostéotomie tibiale de valgisation avec comblement cimenté. Les 28 cas ont été revus à un recul moyen de 3,7 ans avec des extrêmes entre 2 et 9 ans, l’âge moyen de nos malades était de 52 ans avec des extrêmes de 40 à 67 ans, le sexe féminin était prédominant (64%). Le genu varum était primitif dans 20 cas (71,4%), et secondaire dans 8 cas (28,5%). Les stades I et II d'Ahlback constituaient la majorité des cas de l'arthrose fémoro-tibiale (94,7%). La déviation angulaire globale moyenne était de 11,3° avec des extrêmes de 8,5° à 18°. Les résultats évalués selon le protocole du groupe Guépar étaient excellents et très bons dans 86% des cas, et moyens et

  13. Mapping variations in weight percent silica measured from multispectral thermal infrared imagery - Examples from the Hiller Mountains, Nevada, USA and Tres Virgenes-La Reforma, Baja California Sur, Mexico

    USGS Publications Warehouse

    Hook, S.J.; Dmochowski, J.E.; Howard, K.A.; Rowan, L.C.; Karlstrom, K.E.; Stock, J.M.

    2005-01-01

    Remotely sensed multispectral thermal infrared (8-13 ??m) images are increasingly being used to map variations in surface silicate mineralogy. These studies utilize the shift to longer wavelengths in the main spectral feature in minerals in this wavelength region (reststrahlen band) as the mineralogy changes from felsic to mafic. An approach is described for determining the amount of this shift and then using the shift with a reference curve, derived from laboratory data, to remotely determine the weight percent SiO2 of the surface. The approach has broad applicability to many study areas and can also be fine-tuned to give greater accuracy in a particular study area if field samples are available. The approach was assessed using airborne multispectral thermal infrared images from the Hiller Mountains, Nevada, USA and the Tres Virgenes-La Reforma, Baja California Sur, Mexico. Results indicate the general approach slightly overestimates the weight percent SiO2 of low silica rocks (e.g. basalt) and underestimates the weight percent SiO2 of high silica rocks (e.g. granite). Fine tuning the general approach with measurements from field samples provided good results for both areas with errors in the recovered weight percent SiO2 of a few percent. The map units identified by these techniques and traditional mapping at the Hiller Mountains demonstrate the continuity of the crystalline rocks from the Hiller Mountains southward to the White Hills supporting the idea that these ranges represent an essentially continuous footwall block below a regional detachment. Results from the Baja California data verify the most recent volcanism to be basaltic-andesite. ?? 2005 Elsevier Inc. All rights reserved.

  14. Comparaison des effets de la xylazine et de la romifidine administrées en période péri-opératoire sur le réveil de chevaux anesthésiés

    PubMed Central

    Bauquier, Sébastien H.; Kona-Boun, Jean-Jacques

    2011-01-01

    Cette étude prospective compare les effets de la xylazine et de la romifidine sur la qualité du réveil de chevaux anesthésiés. Vingt-huit chevaux sains présentés pour des arthroscopies étaient aléatoirement distribués entre 2 groupes. Le protocole anesthésique intraveineux du groupe xylazine comprenait : butorphanol (0,02 mg/kg) et xylazine (0,5–0,7 mg/kg) en prémédication, diazépam (0,1 mg/kg), kétamine (2,2 mg/kg) et isoflurane comme agents anesthésiques, et xylazine (0,1 mg/kg) comme sédatif au réveil. La xylazine était remplacée par la romifidine 0,05–0,08 mg/kg (prémédication) et 0,01 mg/kg (réveil) dans le groupe romifidine. La qualité du réveil était évaluée à l’aveugle au moyen d’une grille d’évaluation. Le test de la somme des rangs de Wilcoxon (P < 0,05) a été utilisé pour l’analyse statistique. Les notes de la qualité du réveil n’étaient pas statiquement différentes entre les deux groupes. Dans cette étude, la romifidine et la xylazine influençaient de façon similaire la qualité du réveil. PMID:22379199

  15. Effets de l'interaction avec l'oxygène sur le comportement de couches semi-conductrices de ZnO, SnO{2} et CdSe

    NASA Astrophysics Data System (ADS)

    Ain-Souya, A.; Ghers, M.; Haddad, A.; Tebib, W.; Rehamnia, R.; Messsalhi, A.; Bounouala, M.; Djouama, M. C.

    2005-05-01

    Les propriétés superficielles des matériaux solides diffèrent de celles du volume. A la surface, des défauts de différentes natures peuvent être présents. Ils permettent à la surface d'être interactive avec le milieu ambiant. Les multiples interactions entre les états de surface et des éléments du milieu extérieur peuvent modifier les propriétés superficielles. Ce travail étudie la régénération de couches semi-conductrices après adsorption isotherme d'oxygène à différentes températures effectuées entre 20 ° C et 300 ° C. Les matériaux qui ont servi à l'étude sont des couches de ZnO, SnO{2} et CdSe. Celles de CdSe ont été obtenues par co-évaporation, sous vide, de cadmium et de sélénium. Les échantillons de ZnO et SnO{2} ont été élaborés par oxydation, à des températures respectives de 450 ° C et 200 ° , de Zn et Sn déposés par électrolyse et par évaporation sous vide. Les matériaux évaporés ont été déposés sur des plaquettes en verre, les autres ont été électrodéposés sur des substrats métalliques. Les variations des propriétés électriques des couches ont été suivies par mesure de leur résistance électrique superficielle R. Les courbes LogR = f (103 /T (K)), relevées sous vide à différentes températures, sont caractéristiques d'un comportement de semi-conducteur. Des essais d'adsorption d'O{2} à différentes températures montrent des variations considérables de R. En effet, la chimisorption forte d'un gaz par une surface semi-conductrice est telle que l'échange électronique entre adsorbant et adsorbat provoque la formation d'une zone de charge d'espace modifiant la conduction superficielle. Les résultats mettent en évidence des domaines de température de plus haute sensibilité à l'oxygène. Pour le CdSe, certaines désorptions isothermes ont été suffisantes pour une régénération totale des échantillons. Les couches de ZnO ont souvent nécessité des désorptions programm

  16. Migration of As, Hg, Pb, and Zn in arroyo sediments from a semiarid coastal system influenced by the abandoned gold mining district at El Triunfo, Baja California Sur, Mexico.

    PubMed

    Marmolejo-Rodríguez, Ana Judith; Sánchez-Martínez, Martha Alicia; Romero-Guadarrama, Juan Armando; Sánchez-González, Alberto; Magallanes-Ordóñez, Víctor René

    2011-08-01

    Extensive waste deposits (tailings) and ash from the ignition oven of the abandoned gold mine of mining district El Triunfo (MD-ET) in Baja California Sur, Mexico have released trace elements into the sediments of the Hondo-Las Gallinas-El Carrizal arroyo, which connects to the Pacific Ocean through an evaporitic basin. Migration of these elements through the arroyo is mainly caused by winds or tropical hurricanes that occur sporadically during the summer and cause the otherwise dry arroyo to overflow. To evaluate the concentration and distribution of the elements As, Hg, Pb, and Zn along the 48 km arroyo, surface sediments were collected from 26 sites, ranging from close to the MD-ET to the mouth of the arroyo at the Pacific Ocean. Concentrations in tailings and ash were for As 8890 and 505 000 mg kg(-1); for Hg 0.336 and 54.9 mg kg(-1); for Pb 92,700 and 19,300 mg kg(-1); and for Zn 49,600 and 1380 mg kg(-1). The average of the Normalized Enrichment Factor (Av-NEF) in surface sediments, calculated using background levels, indicates that the sediments are severely contaminated with As and Zn (Av-NEF = 22), Pb (Av-NEF = 24) and with a moderate contamination of Hg (Av-NEF = 7.5). The anthropogenic influence of those elements is reflected in the arroyo sediments as far as 18 km away from the MD-ET, whereas the samples closest to the discharge into the Pacific Ocean show a natural to moderate enrichment for As and Zn and low or no enrichment for Hg and Pb. A principal components analysis identified four principal components that explained 90% of the total variance. Factor 1 was characterized by a high positive contribution of the anthropogenic source elements, especially As, Pb, and Zn (37%), whereas Factor 2 was strongly correlated with the oxy-hydroxides of Fe and Mn (27%). Factor 3 was correlated with Li (16%) and Factor 4 with Al (10%), which indicates more than one source of lithogenic composition, though they played a minor role in the distribution of the

  17. Impact of HIV-1 genetic diversity on plasma HIV-1 RNA Quantification: usefulness of the Agence Nationale de Recherches sur le SIDA second-generation long terminal repeat-based real-time reverse transcriptase polymerase chain reaction test.

    PubMed

    Rouet, François; Chaix, Marie-Laure; Nerrienet, Eric; Ngo-Giang-Huong, Nicole; Plantier, Jean-Christophe; Burgard, Marianne; Peeters, Martine; Damond, Florence; Ekouevi, Didier Koumavi; Msellati, Philippe; Ferradini, Laurent; Rukobo, Sandra; Maréchal, Valérie; Schvachsa, Nilda; Wakrim, Lahcen; Rafalimanana, Christian; Rakotoambinina, Benjamin; Viard, Jean-Paul; Seigneurin, Jean-Marie; Rouzioux, Christine

    2007-08-01

    The high genetic diversity of HIV-1 has a major impact on the quantification of plasma HIV-1 RNA, representing an increasingly difficult challenge. A total of 898 plasma specimens positive for HIV-1 RNA by commercial assays (Amplicor v1.5; Roche Diagnostic Systems, Alameda, CA or Versant v3.0; Bayer Diagnostics, Emeryville, CA) were tested using the Agence Nationale de Recherches sur le SIDA second-generation (G2) real-time reverse transcriptase polymerase chain reaction (RT-PCR) test: 518 samples containing HIV-1 of known subtype, including 88 from 2 subtype panels and 430 harboring B (n = 266) and non-B (n = 164) group M HIV-1 subtypes from patients followed up in 2002 through 2005 at Necker Hospital (Paris, France), and 380 samples from 10 different countries (Argentina, Cambodia, Cameroon, Central African Republic, France, Ivory Coast, Madagascar, Morocco, Thailand, and Zimbabwe). HIV-1 RNA values obtained by G2 real-time PCR were highly correlated with those obtained by the Amplicor v1.5 for B and non-B subtypes (R = 0.892 and 0.892, respectively) and for samples from diverse countries (R = 0.867 and 0.893 for real-time PCR vs. Amplicor v1.5 and real-time PCR vs. Versant v3.0, respectively). Approximately 30% of specimens harboring non-B subtypes were underquantified by at least -0.51 log10 in Amplicor v1.5 versus 5% underquantified in G2 real-time PCR. Discrepant results were also obtained with subtype B samples (14% underquantified by Amplicor v1.5 vs. 7% by G2 real-time PCR). Similar percentages were observed when comparing results obtained with the G2 real-time PCR assay with those obtained using the Versant assay. Addressing HIV-1 diversity, continual monitoring of HIV-1 RNA assays, together with molecular epidemiology studies, is required to improve the accuracy of all HIV RNA assays.

  18. Seasonal variations recorded in cave monitoring results and a 10 year monthly resolved speleothem δ18O and δ13C record from the Han-sur-Lesse cave, Belgium

    NASA Astrophysics Data System (ADS)

    Van Rampelbergh, M.; Verheyden, S.; Allan, M.; Quinif, Y.; Keppens, E.; Claeys, P.

    2014-04-01

    Speleothems provide paleoclimate information on multi-millennial to decadal scales in the Holocene. However seasonal or even monthly resolved records remain scarce. They require fast growing stalagmites and a good understanding of the proxy transfer function on very short time scales. The Proserpine stalagmite from the Han-sur-Less cave (Belgium) displays seasonal layers of 0.5 to 2 mm thickness that reconstruct paleoclimates at a monthly scale. Through a regular cave monitoring, we acquired a good understanding of how δ18O and δ13C signals in modern calcite reflect climate variations on sub-seasonal scale. Cave parameters vary seasonally in response to the activity of the vegetation cover and outside air temperature. From December to June, the cave remains in "winter-mode". Outside temperatures are cold inducing low cave air and water temperatures. Bio-productivity in the soil is limited leading to low pCO2, higher δ13C composition of the CO2 in the cave air and high discharge due to the inactivity of the plant coverage. From June to December, the cave switches to "summer-mode" and the measured factors display an opposite behavior. The δ18O and δ13C signals of fresh calcite precipitated on glass slabs vary seasonally. Lowest δ18O values occur during the summer-mode when the δ13C values are high. The δ18O composition of the calcite is in equilibrium with the drip water δ18O and display seasonal variations due to changes in the cave air and water temperature. In contrast to the δ18O signal, δ13C values of the calcite precipitated on the glass slabs do not reflect equilibrium conditions. Highest δ13C values occur during summer, when discharge rates are low increasing the evaporation effect on the thin water film covering the stalagmite. This same antithetical behavior of the δ18O vs. the δ13C signals is seen in the monthly resolved speleothem record that covers the period between 1976 and 1985 AD. Dark layers are formed during summer, while light layers

  19. Effet de la substitution du cuivre par du lithium sur les proprietes de l'oxyde spinelle lithium(x)cuivre(y-x)cobalt(3-y)oxygen(4) etudie pour l'electrocatalyse de la reaction de degagement de l'oxygene en milieu alcalin

    NASA Astrophysics Data System (ADS)

    Fatih, Khalid

    L'electrolyse de l'eau demeure la seule technologie industrielle de generation de l'hydrogene et de l'oxygene tres purs sans rejet de CO2 dans l'atmosphere, ce qui le rend tres attrayant par rapport a la combustion de carburants fossiles qui provoque presentement de serieux problemes environnementaux. Dans le but d'ameliorer le rendement de ce procede, nous avons developpe de nouveaux materiaux d'anode peu couteux, a base de l'oxyde mixte CuyCo3-yO 4, qui possedent une cinetique rapide pour la reaction de degagement de l'oxygene (RDO). Cette reaction suscite un interet particulier en raison de la surtension d'activation relativement elevee a l'anode qui cause la principale perte de rendement du procede. Une etude systematique a ete effectuee sur la substitution du Cu par du Li (0 a 40%), afin d'elucider les proprietes electrocatalytiques des oxydes LixCuy-xCo3-yO4. Ces oxydes, prepares sous forme de poudres par decomposition thermique des nitrates precurseurs entre 300 et 500°C, ont montre (DRX et FTIR) une structure spinelle inverse non-stcechiometrique avec une diminution du volume de la maille cristalline. La surface specifique par BET est d'environ 6 m2 g-1. Le pcn, obtenu par titrage acido-basique, a indique une diminution de la force du lien M-OH avec le taux du Li dans l'oxyde. Les analyses par XPS, realisees sur des films d'oxyde prepares par nebulisation reactive sur un substrat lisse de nickel, revelent un enrichissement de la surface en Cu a partir de 30% Li, et la presence des cations de surface Co2+, Co3+, Cu +, Cu2+ et Cu3+. La concentration de ce dernier montre un maximum a 10 et 20% Li. Suite a la substitution du Cu par du Li, la compensation de la charge serait assuree principalement par la formation d'especes Cu3+ pour les oxydes contenant jusqu'a 20% Li, et par la formation d'especes Co3+ aux taux de substitution superieurs. Les micrographies MEB montrent une morphologie hemispherique des particules d'oxyde reparties uniformement sur le substrat

  20. FIRE_AX_SOF_SUR_MET

    Atmospheric Science Data Center

    2015-11-25

    ... Campaigns Radiation Budget Aerosols Level:  L2 Platform:  Buoy Instrument:  ... Parameters:  Dry Bulb Temperature Pressure Sea Surface Temperature Wet Bulb Temperature Wind Direction Wind Speed ...

  1. Sur le remodelage des tissus osseux anisotropes

    NASA Astrophysics Data System (ADS)

    DiCarlo, Antonio; Naili, Salah; Quiligotti, Sara

    2006-11-01

    Growth (change of relaxed lengths) and remodelling (change of mechanical properties) are both involved in the morphogenesis of biological tissues. To model them is of paramount import for progressing both in scientific understanding and health technologies. We model bone tissue as a microstructured continuum, whose mechanical properties at the macroscopic scale are described by a linear, anisotropic elastic response that evolves in time. Our kinematics is rich enough to allow for the microstructural evolution, as well as for the interplay between stress, growth and remodelling. This is a unified approach to the mechanics of growth and remodelling, in which all balance laws derive from one virtual-power principle. As a first application, we study the problem of stiffness remodelling due to planar rotation of the microstructure, excluding bulk growth and all physiological response to mechanical stimuli (passive remodelling). To cite this article: A. DiCarlo et al., C. R. Mecanique 334 (2006).

  2. Effect of intermittent hypoxia on the reproduction of rats exposed to high altitude in the Chilean Altiplano.

    PubMed

    Cikutovic, Marcos; Fuentes, Nelson; Bustos-Obregón, Eduardo

    2009-01-01

    Environmental parameters such as the large day-night temperature differences, high light radiation, and low humidity may have a synergistic effect with low oxygen pressure. To evaluate the effects of the exposure to intermittent chronic hypobaric hypoxia (ICHH) in nature on rat reproduction, a group of rats was alternately moved to a location at 3400 meters over sea level (moml) for 7 days and returned the subsequent week to sea level; this procedure was repeated six times. Hematological and reproductive parameters were measured and analyzed. At the end of the experimental protocol, hematocrit and hemoglobin concentrations were significantly greater in the ICHH group compared to the control group (Nx) (p < 0.05). The diameter of the seminiferous tubule and the height of the spermatogenic epithelium in ICHH rats presented a significant decrease in relation to Nx rats (p < 0.05). Consequently, the number of epididymal spermatozoa in the experimental animals decreased compared to normal rats, with no evidence of recovery after 84 days. The offspring of the different matings between normal and hypoxic animals decreased proportionally to hypoxia exposure. The low oxygen and the changes in testicular temperature homeostasis would provide a novel local mechanism to explain the decrease in sperm cell production and the reduced number of puppies born. The alterations of the reproductive parameters of the hypoxic female, plus testicular injuries and diminished sperm in males, result in a significant decrease in the reproductive activity of the animals.

  3. The effect of high altitude on the glycolytic activity of erythrocytes in natives of the Andean Altiplano.

    PubMed

    Arnaud, J; Gutiérrez, N; Vergnes, H

    1983-01-01

    Glucose consumption by anaerobic glycolysis and the pentose pathway were studied in two Aymara populations living at different altitudes (3 600 m and 450 m). The measurements were made both with and without methylene blue. We observed a Pasteur effect for both pathways which may explain the increase in 2-3 DPG and ATP levels found in blood samples from people living at high altitudes. The results in the presence of methylene blue showed a reduced activity of the methaemoglobin reductase system in the high altitude group which may be partly responsible for their increased levels of methaemoglobin.

  4. Antibodies to pathogenic livestock viruses in a wild vicuña (Vicugna vicugna) population in the Argentinean Andean altiplano.

    PubMed

    Marcoppido, Gisela; Parreño, Viviana; Vilá, Bibiana

    2010-04-01

    Serum samples from 128 wild vicuñas (Vicugna vicugna) were tested for antibodies (Ab) to rotavirus (RV), bovine parainfluenza virus 3 (BPIV-3), bovine herpesvirus-1 (BHV-1), bovine viral diarrhea virus (BVDV-1), foot-and-mouth disease virus (FMDV), bluetongue virus (BTV), equine herpesvirus-1 (EHV-1), and influenza A virus equine (EIV). Samples were collected in Cieneguillas Province of Jujuy, in northern Argentina. Feces from 44 vicuñas were also collected to investigate RV shedding. Llamas (Lama glama) and domestic cattle (Bos taurus) from the area studied also were tested for antibodies to these viruses. Antibodies against RV (100%) and BPIV-3 (37%) were detected in the vicuñas sampled. No RV antigen was detected in any of the fecal samples tested. One vicuña was positive for Ab to BHV-1 (0.8%) and another for BVDV-1 (0.8%). The Ab prevalences detected in llamas were: 100% (16/16) for RV, 47% (8/17) for BPIV-3, 17.6% (3/17) for BHV-1, and 5.9% (1/17) for BVDV-1. However, domestic cattle had high antibody prevalences for RV and BPIV-3, 100% (13/13) and 73% (11/15), respectively, but were negative for Ab to BHV-1 and BVDV. No antibodies against FMDV, BTV, EHV-1, or EIV were detected in wild vicuñas or domestic species. Because no data of viral circulation on wild vicuñas are available, this report represents the first evidence of viral infection in wild vicuñas from the Argentinean Andean Puna.

  5. Cardiovascular function in term fetal sheep conceived, gestated and studied in the hypobaric hypoxia of the Andean altiplano.

    PubMed

    Herrera, Emilio A; Rojas, Rodrigo T; Krause, Bernardo J; Ebensperger, Germán; Reyes, Roberto V; Giussani, Dino A; Parer, Julian T; Llanos, Aníbal J

    2016-03-01

    High-altitude hypoxia causes intrauterine growth restriction and cardiovascular programming. However, adult humans and animals that have evolved at altitude show certain protection against the effects of chronic hypoxia. Whether the highland fetus shows similar protection against high altitude gestation is unclear. We tested the hypothesis that high-altitude fetal sheep have evolved cardiovascular compensatory mechanisms to withstand chronic hypoxia that are different from lowland sheep. We studied seven high-altitude (HA; 3600 m) and eight low-altitude (LA; 520 m) pregnant sheep at ∼90% gestation. Pregnant ewes and fetuses were instrumented for cardiovascular investigation. A three-period experimental protocol was performed in vivo: 30 min of basal, 1 h of acute superimposed hypoxia (∼10% O2) and 30 min of recovery. Further, we determined ex vivo fetal cerebral and femoral arterial function. HA pregnancy led to chronic fetal hypoxia, growth restriction and altered cardiovascular function. During acute superimposed hypoxia, LA fetuses redistributed blood flow favouring the brain, heart and adrenals, whereas HA fetuses showed a blunted cardiovascular response. Importantly, HA fetuses have a marked reduction in umbilical blood flow versus LA. Isolated cerebral arteries from HA fetuses showed a higher contractile capacity but a diminished response to catecholamines. In contrast, femoral arteries from HA fetuses showed decreased contractile capacity and increased adrenergic contractility. The blunting of the cardiovascular responses to hypoxia in fetuses raised in the Alto Andino may indicate a change in control strategy triggered by chronic hypoxia, switching towards compensatory mechanisms that are more cost-effective in terms of oxygen uptake.

  6. Les myélopathies cervicarthrosiques: résultat clinique et radiologique de la chirurgie sur une série de 135 patients opérés au service de neurochirurgie CHU Avicenne

    PubMed Central

    Djoubairou, Ben Ousmanou; Nabil, Moussé; Karekezi, Claire; Diawara, Seylan; El Fatemi, Nizar; Gana, Rachid; El Abbadi, Najia; Maaqili, Moulay Rachid

    2014-01-01

    La myélopathie cervicarthrosique est un syndrome clinique en relation avec la diminution des dimensions du canal rachidien, la cervicarthrose est l’étiologie principale après 50 ans. L'objectif du traitement est de rétablir les dimensions du canal rachidien cervical. Le choix de la technique chirurgicale sera guidé par l'analyse des signes cliniques, imageries, pré opératoire en fonction de laquelle sera pratiquée soit la voie antérieure, postérieure, ou exceptionnellement la voie combinée. Notre étude a pour but dans un premier temps d’évaluer à long terme les résultats cliniques et radiologiques de la chirurgie ensuite répondre à cette préoccupation: La lordose cervicale pré opératoire et postopératoire sont t-elles des facteurs de bon pronostic? Nous rapportons une étude rétrospective entre 2000 et 2013 portant sur 135 patients opérés dans notre formation et remplissant les critères inclusions. La collecte des données s'est faite en s'aidant du dossier médical des patients (échelle d'Association des orthopédistes Japonais), Imagerie (Radio, TDM, IRM), mesure de l'angle de courbure rachidienne en pré et postopératoire, ceci dans le but d’évaluer à long terme les résultats clinique et radiologique de la chirurgie. Ont été inclus dans notre étude 135 patients, 82 Hommes (60%), 53 femmes (40%) avec un âge moyen de 52 ans, ayant consulté pour des motifs divers (Névralgies cervicobrachiales, lourdeur des membres, troubles génito-sphinctériens). Soixante cinq patients (48%) ont bénéficié d'un abord antérieur (dissectomie, cloward, somatotomie médiane), 64 patients (47%) ont été opérés par voie postérieure (laminectomie de 1 à 3 niveaux) et 6 patients (5%) ont bénéficié d'un abord combiné dans un délai moyen de 3 mois devant la persistance des symptômes. Le niveau cervical le plus touché était C5C6 suivie de C4C5. L’évolution globale de nos patients était favorable dans 58% des cas, stationnaire

  7. Monitoring of a fast-growing speleothem site from the Han-sur-Lesse cave, Belgium, indicates equilibrium deposition of the seasonal δ18O and δ13C signals in the calcite

    NASA Astrophysics Data System (ADS)

    Van Rampelbergh, M.; Verheyden, S.; Allan, M.; Quinif, Y.; Keppens, E.; Claeys, P.

    2014-10-01

    Speleothems provide paleoclimate information on multimillennial to decadal scales in the Holocene. However, seasonal or even monthly resolved records remain scarce. Such records require fast-growing stalagmites and a good understanding of the proxy system on very short timescales. The Proserpine stalagmite from the Han-sur-Less cave (Belgium) displays well-defined/clearly visible darker and lighter seasonal layers of 0.5 to 2 mm thickness per single layer, which allows a measuring resolution at a monthly scale. Through a regular cave monitoring, we acquired a good understanding of how δ18O and δ13C signals in modern calcite reflect climate variations on the seasonal scale. From December to June, outside temperatures are cold, inducing low cave air and water temperature, and bio-productivity in the soil is limited, leading to lower pCO2 and higher δ13C values of the CO2 in the cave air. From June to December, the measured factors display an opposite behavior. The absence of epikarst water recharge between May and October increases prior calcite precipitation (PCP) in the vadose zone, causing drip water to display increasing pH and δ13C values over the summer months. Water recharge of the epikarst in winter diminishes the effect of PCP and as a result the pH and δ13C of the drip water gradually decrease. The δ18O and δ13C signals of fresh calcite precipitated on glass slabs also vary seasonally and are both reflecting equilibrium conditions. Lowest δ18O values occur during the summer, when the δ13C values are high. The δ18O values of the calcite display seasonal variations due to changes in the cave air and water temperature. The δ13C values reflect the seasonal variation of the δ13CDIC of the drip water, which is affected by the intensity of PCP. This same anticorrelation of the δ18O versus the δ13C signals is seen in the monthly resolved speleothem record that covers the period between 1976 and 1985 AD. Dark layers display lower δ18O and higher δ13C

  8. Le Phénomène Wolf-Rayet au Sein des Etoiles chaudes de Populations I et II: Histoire des Vents stellaires et Impact sur la Structure nébulaire circumstellaire

    NASA Astrophysics Data System (ADS)

    Grosdidier, Yves

    2000-12-01

    Les spectres des étoiles Wolf-Rayet pop. I (WR) présentent de larges raies en émission dues à des vents stellaires chauds en expansion rapide (vitesse terminale de l'ordre de 1000 km/s). Le modèle standard des étoiles WR reproduit qualitativement le profil général et l'intensité des raies observées. Mais la spectroscopie intensive à moyenne résolution de ces étoiles révèle l'existence de variations stochastiques dans les raies (sous-pics mobiles en accélération échelles de temps: environ 10-100 min.). Ces variations ne sont pas comprises dans le cadre du modèle standard et suggèrent une fragmentation intrinsèque des vents. Cette thèse de doctorat présente une étude de la variabilité des raies spectrales en émission des étoiles WR pop. II; la question de l'impact d'un vent WR fragmenté sur le milieu circumstellaire est aussi étudiée: 1) à partir du suivi spectroscopique intensif des raies CIIIl5696 et CIVl5801/12, nous analysons quantitativement (via le calcul des Spectres de Variance Temporelle) les vents issus de 5 étoiles centrales de nébuleuses planétaires (NP) galactiques présentant le phénomène WR; 2) nous étudions l'impact de la fragmentation des vents issus de deux étoiles WR pop. I sur le milieu circumstellaire via: i) l'imagerie IR (NICMOS2/HST) de WR 137, et ii) l'imagerie H-alpha (WFPC2/HST) et l'interférométrie Fabry-Perot H-alpha (SIS-CFHT) de la nébuleuse M 1-67 (étoile centrale: WR 124). Les principaux résultats sont les suivants: VENTS WR POP. II: (1) Nous démontrons la variabilité spectroscopique intrinsèque des vents issus des noyaux de NP HD 826 ([WC 8]), BD +30 3639 ([WC 9]) et LSS 3169 ([WC 9]), observés durant respectivement 22, 15 et 1 nuits, et rapportons des indications de variabilité pour les noyaux [WC 9] HD 167362 et He 2-142. Les variabilités de HD 826 et BD +30 3639 apparaissent parfois plus soutenues (``bursts'' qui se maintiennent durant plusieurs nuits); (2) La cinématique des sous

  9. Détermination d'un pǒle paléomagnétique et mise en évidence d'aimantations à polarité normale sur les formations du Permien supérieur du Massif des Maures (France)

    NASA Astrophysics Data System (ADS)

    Merabet, N.; Daly, L.

    1986-10-01

    Des roches sédimentaires du Massif des Maures (latitude: 43,4°N, longitude: 6,3°E), appartenantàla famille des pélites et dont l'ǎge bien préciséest Permian supérieur (Thuringien), ontétéétudiées par analyse thermique et par champs alternatifs. La direction moyenne de l'aimantation caractéristique, obtenueàpartir de 103échantillons, en donnant le měme poids aux 10 sites, est définie par D = -164°, I = -14° et α 95 = 4° , et le pǒle paléomagnétique Nord correspondant est situéà51°N, 161°E avec A 95 = 3,5° . Ce pǒle est très proche de la partie 230-250 Ma de la courbe de migration polaire européenne. Il estégalement proche des pǒles du Permien supérieur obtenus par Zijderveld en Estérel oriental, et de ceux d'U.R.S.S., obtenus sur les formations rouges de la Volga dont l'ǎge est Tatarien supérieur. Ce résultat montre qu'il n'y a pas eu de déplacement tectonique important dans la région depuis le Permien, et le pǒle peut doncětre considérécomme une nouvelle contribution. Une polariténormale a puětre correctement isolée sur 20% deséchantillons. Ce résultat, très similaireàcelui obtenu sur les formations rouges du Permien supérieur de la Volga, apporte un nouvel argument en faveur de la solution qui situe la limite supérieure de l'intervalle Kiaman au début du Thuringien.

  10. Etude de l'effet de la température de dépôt ou de recuit sur la formation de l'interface Au/GaSb(100) par diffraction d'électrons lents et spectroscopies d'électrons Auger ou de pertes d'énergies

    NASA Astrophysics Data System (ADS)

    Rouanet, M.; Oueini, W.; Nouaoura, M.; Bertru, N.; Bonnet, J.; Lassabatere, L.

    1995-05-01

    Auger electron spectroscopy (AES), energy electron loss spectroscopy (EELS) and low energy electron diffraction (LEED) are used to precise the interaction of gold with GaSb(100) surfaces grown on GaSb substrates by molecular beam epitaxy (MBE). After the growth, the GaSb layers, produced in the laboratory, were transferred by the mean of an ultra vacuum lock chamber, into an other ultra vacuum devoted to the deposit of gold and to the physical studies. Measurements were first performed on the clean surfaces and then on surfaces covered by increasing amounts of gold (6 × 10^{13} 1.8 × 10^{16} atoms cm^{-2}) deposited on substrates brought at room temperature or at low temperature (220 K). The samples were then studied during the annealing up to 520 K. The results show, at the beginning of the deposition, gold was adsorbed on the MBE GaSb(100) surface. When the gold coverage increases and becomes higher than 10^{15} atomes cm^{-2}, Au diffuses into the bulk and forms alloys. Nous étudions par spectroscopie d'électrons Auger (SEA), spectroscopie de pertes d'énergies d'électrons lents (SPEEL) et diffraction d'électrons lents (DEL), l'adsorption de l'or sur des surfaces (100) de couches de GaSb obtenues au laboratoire par épitaxie par jets moléculaires (EJM) sur des substrats de GaSb, puis transférées pour dépôt et étude dans l'enceinte à ultravvide de dépôt métallique par l'intermédiaire d'un sas sous ultravide. Les mesures sont effectuées avant et après dépôts d'or (6 × 10^{13} 1,8 × 10^{16} atomes cm^{-2}) réalisés sur un substrat à la température ambiante ou refroidi à 220 K. Les échantillons sont ensuite étudiés pendant lerecuit jusqu'à 520 K. Les résultats obtenues montrent que l'or, dans un premier temps s'adsorbe sur la surface, puis, lorsque le dépôt augmente, diffuse dans le volume du matériau. cette diffusion, qui peut s'acompagner de la formation d'alliages, n'est cependant notable dans la gamme de température utilis

  11. Tensions entre rationalité technique et intérêts politiques : l’exemple de la mise en œuvre de la Loi sur les agences de développement de réseaux locaux de services de santé et de services sociaux au Québec

    PubMed Central

    Contandriopoulos, D.; Hudon, Raymond; Martin, Elisabeth; Thompson, Daniel

    2013-01-01

    Sommaire L’objet de cet article est constitué par les processus décisionnels entourant la mise en œuvre de la Loi sur les agences de développement de réseaux locaux de services de santé et de services sociaux (Loi 25). Nous entendons mettre en lumière les stratégies des groupes ou institutions de diverses natures qui ont fait valoir leurs préférences et ont tenté, avec un succès inégal, d’influencer les décisions relatives à cette réforme majeure de la structure du système de santé québécois. Au plan théorique, nous nous appuyons principalement sur les modèles d’analyse du lobbying qui, depuis les travaux fondateurs de Milbrath (1960, 1963), présentent cette pratique comme un processus fondamental d’échange d’information. Selon les données colligées dans les retranscriptions d’entrevues, les stratégies observées correspondent effectivement aux caractéristiques constitutives du lobbying et, dans quelques situations, à celles du patronage. La combinaison de ces divers éléments révèle que la mise en œuvre de la Loi 25 s’avère être avant tout un processus proprement politique. Ainsi, furent relégués au second plan les arguments techniques qui composaient initialement les objectifs de la Loi. PMID:23509412

  12. Evaluation du traitement antirétroviral chez les femmes enceintes VIH-1 positif, sur la transmission de l'infection de la mère à l'enfant: cas du Centre Médical Saint Camille de Ouagadougou, au Burkina Faso

    PubMed Central

    Soubeiga, Serge Theophile; Compaore, Rebecca; Djigma, Florencia; Zagre, Nicaise; Assengone, Elsa; Traore, Lassina; Diarra, Birama; Bisseye, Cyrille; Ouermi, Djeneba; Sagna, Tani; Karou, Simplice; Pietra, Virginio; Simpore, Jacques

    2015-01-01

    Introduction L'infection au VIH chez les nouveau-nés par leur mère peut être réduite grâce à des programmes de prévention de transmission mère-enfant du VIH (PTME). L'objectif dans cette étude était d’évaluer le traitement antirétroviral chez les femmes enceintes VIH-1 positif sur la transmission mère-enfant de l'infection au Centre Médical Saint Camille de Ouagadougou, Burkina Faso. Méthodes Des échantillons de spot de sang total ont été collectés chez 160 enfants âgés de 6 semaines, nés de mères VIH-1 positif et chez 40 enfants âgés de 2 à 13 mois provenant d'orphelinats et dont les mères étaient inconnues. Ces échantillons ont été testés avec le kit Abbott Real Time HIV-1 Qualitative. Un questionnaire a permis de connaitre les âges et les fonctions des femmes enceintes. Résultats Les femmes enceintes avaient un âge moyen global de 29,50±5,19 ans. Au total, 50,5% (101/200) ont été mises sous combinaison AZT/3TC/NVP et 29,5% (59/200) étaient sous prophylaxie (AZT/3TC). Le taux de transmission verticale du VIH-1 était de 0,0% (0/160) (p < 0,001) chez les enfants dont les mères étaient sous combinaison AZT/3TC/NVP ou sous prophylaxie AZT/3TC et de 15,0% (6/40) chez les enfants orphelins qui n’étaient pas inclus dans le protocole de la PTME. Conclusion Selon les résultats, le protocole de la PTME est efficace et réduit très significativement le risque de transmission du VIH-1 de la mère à l'enfant. De plus, le dépistage par PCR, des enfants orphelins infectés verticalement par le VIH, permet leur prise en charge thérapeutique précoce. PMID:26301003

  13. Herd evaluation by enzyme-linked immunosorbent assay for the determination of Fasciola hepatica infection in sheep and cattle from the Altiplano of Bolivia.

    PubMed

    Hillyer, G V; Soler de Galanes, M; Buchón, P; Bjorland, J

    1996-02-01

    A study was designed to determine by ELISA the seroprevalence of fasciolosis both in sheep (29 herds totaling 184 sheep), in samples collected in 1988, and in cattle (41 herds totaling 299 animals, samples collected in 1988; 34 herds totaling 147 animals, samples collected in 1989) in the same area of Corapata in which a seroprevalence survey had been done in humans. The results show high seropositivity in sheep (89%) and lower seropositivity in cattle (58% in 1988, and 57% in 1989). The seroprevalence in cattle in 1988 was essentially identical to that detected in 1989. Faecal examinations were also done in the 1988 sheep and 1989 cattle. Results of the study showed that of the 184 sheep examined, 22 were positive for F. hepatica eggs, while 163 were positive by serology. All of the 22 sheep which were positive parasitologically were also positive serologically for a sensitivity of 100%. On the other hand, of 147 cattle tested, 38 were positive parasitologically while 84 were positive serologically. Of the 38 positives for F. hepatica eggs, 31 were positive by serology (sensitivity 82%).

  14. New KAr age determinations of intrusive rocks from the Cordillera Occidental and Altiplano of central Peru: Identification of magmatic pulses and episodes of mineralization

    NASA Astrophysics Data System (ADS)

    Soler, P.; Bonhomme, M. G.

    The post-Albian evolution of the Andes of central Peru is characterized by igneous activity, both effusive and intrusive, and by at least six distinct episodes of compressional tectonics. New KAr age determinations have been made of intrusive rocks from the Cajatambo-Oyón-Cerro de Pasco area. In conjunction with already published information, these new data permit a better estimate of the ages and the lateral extent of successive Cenozoic magmatic arcs. Metallogenetic implications of the 26.3-29.3 Ma age of mineralized Milpo-Atacocha intrusions are also discussed.

  15. Giant fossil tortoise and freshwater chelid turtle remains from the middle Miocene, Quebrada Honda, Bolivia: Evidence for lower paleoelevations for the southern Altiplano

    NASA Astrophysics Data System (ADS)

    Cadena, Edwin A.; Anaya, Federico; Croft, Darin A.

    2015-12-01

    We describe the first Miocene turtle remains from Bolivia, which were collected from the late middle Miocene (13.18-13.03 Ma) of Quebrada Honda, southern Bolivia. This material includes a large scapula-acromion and fragmentary shell elements conferred to the genus Chelonoidis (Testudinidae), and a left xiphiplastron from a pleurodire or side-necked turtle, conferred to Acanthochelys (Chelidae). The occurrence of a giant tortoise and a freshwater turtle suggests that the paleoelevation of the region when the fossils were deposited was lower than has been estimated by stable isotope proxies, with a maximum elevation probably less than 1000 m. At a greater elevation, cool temperatures would have been beyond the tolerable physiological limits for these turtles and other giant ectotherm reptiles.

  16. Acateco de la Frontera Sur (Acateco of the Southern Border).

    ERIC Educational Resources Information Center

    Maldonado, Roberto Zavala

    This document is one of 17 volumes on indigenous Mexican languages and is the result of a project undertaken by the Archivo de Lenguas Indigenas de Mexico. This volume contains information on Acatec, an indigenous language of Mexico spoken along Mexico's southern border. The objective of collecting such a representative sampling of the linguistic…

  17. Recherches sur l'histoire de l'astronomie ancienne

    NASA Astrophysics Data System (ADS)

    Tannery, Paul

    2015-04-01

    Préface; 1. Ce que les Hellènes ont appelé astronomie; 2. Ce que les Hellènes ont appelé astrologie (cont.); 3. Les mathématiciens alexandrins; 4. Les postulats de l'astronomie d'après Ptlolémée et les auteurs élémentaires; 5. La sphéricité de la terre et la mesure de sa circonférence; 6. Le mouvement général des planètes; 7. Les cercles de la sphère; 8. La longueur de l'année solaire; 9. Les tables du soleil; 10. Les périodes d'Hipparque pour les mouvements lunaires; 11. Les tables de la lune; 12. Les parallaxes du soleil et de la lune; 13. Les prédictions d'éclipses; 14. La théorie des planètes; 15. Le catalogue des fixes; Appendice; Errata.

  18. Remarques sur le passif (suite) (Remarks on the Passive)

    ERIC Educational Resources Information Center

    Pinchon, Jacqueline

    1977-01-01

    This installment of the series on the passive considers the subject and the object of the verb under the following headings: part of speech, circumstantial objects and the relationship between clauses and sentences. (Text is in French.) (AMH)

  19. Remarques sur le Passif (Remarks on the Passive Voice)

    ERIC Educational Resources Information Center

    Pinchon, Jacqueline

    1977-01-01

    A short study of definitions of the passive voice in French. Definitions are based on meaning; morphology; syntax; meaning and morphology; and morphology and syntax. The latter is the most widely accepted today. (Text is in French.) (AMH)

  20. Mathematics Comparison Study = Etude Comporative Portant Sur les Mathematiques.

    ERIC Educational Resources Information Center

    Alberta Dept. of Education, Edmonton. Curriculum Standards Branch.

    At the request of the Council of Ministries of Education, Canada (CMEC), Alberta Learning conducted this Mathematics Comparison Study. The focus of this study is from Kindergarten to Grade 12. All provinces and territories were invited to participate, and only the Quebec region declined. Participating regions were invited to send a representative…

  1. Notes sur les mouvements recursifs (Notes on Regressive Moves).

    ERIC Educational Resources Information Center

    Auchlin, Antoine; And Others

    1981-01-01

    Examines the phenomenon of regressive moves (retro-interpretation) in the light of a hypothesis according to which the formation of complex and hierarchically organized conversation units is subordinated to the linearity of discourse. Analyzes a transactional exchange, describing the interplay of integration, anticipation, and retro-interpretation…

  2. Identifying recharge from tropical cyclonic storms, Baja California Sur, Mexico.

    PubMed

    Eastoe, Christopher J; Hess, Greg; Mahieux, Susana

    2015-04-01

    Groundwater in the Todos Santos watershed in southern Baja California, and throughout the peninsula south of latitude 28°N, has values of (δ18 O‰, δD‰) ranging between (-8.3, -57) and (-10.9, -78). Such negative values are uncharacteristic of the site latitude near the sea level. Altitude effects do not explain the isotope data. Tropical depressions originating along the Pacific coast of North America yield rain with isotopic depletion; rain from these weather systems in southern Arizona commonly has δ18O values<-10‰ in comparison with amount-weighted mean summer and fall rain at -6‰. Isotope data indicate hurricane rain as the predominant source of recharge in southern Baja California, where named tropical depressions bring large rains (>50 mm) at least once every 2 to 3 years, and along the Pacific coast between Jalisco and Oaxaca.

  3. SUR UNE REGLE DE "CACAPHONIE" (ON A RULE OF "CACAPHONY").

    ERIC Educational Resources Information Center

    GROSS, MAURICE

    A TRANSFORMATIONAL ANALYSIS OF MODERN FRENCH GRAMMAR IS SIMILAR TO THE "RULE OF CACAPHONY" PROPOSED BY PORT-ROYAL GRAMMARIANS TO AVOID BAD PRONUNCIATION. BY MEANS OF CERTAIN REWRITE RULES, THE CORRECT USAGE OF THE PARTITIVE (DE) CAN BE TAUGHT AND EXPLAINED MORE SIMPLY THAN WAS POSSIBLE USING THE TRADITIONAL METHOD. THE RULE OF CACAPHONY (RC) IS…

  4. Stratigraphy of Reforma Caldera, Baja California Sur, Mexico

    NASA Astrophysics Data System (ADS)

    García Sánchez, L.; Macias, J. L.; Osorio, L. S.; Pola, A.; Avellán, D. R.; Arce, J. L.; Saucedo, R.; Sánchez, J. M.; García-Tenorio, F.; Cisneros, G.; Reyes-Agustín, G.; Cardona, S.; Jimenez, A.

    2015-12-01

    The Reforma caldera is located at ~35 km to the northwest of Santa Rosalía in the central part of the Baja California peninsula. It has 10 km in diameter and a maximum height of 1200 masl in the center and between 100 and 500 masl in its slopes. Reforma is within a tectonic zone affected by two fault systems: A NW-SE normal fault system linked to the opening of the Gulf of California, and a NNW-SSE and NW-SE strike-slip fault system associated with an active Riedel system. Reforma was built upon Cretaceous granites that outcrop at the caldera center, Miocene to Pliocene volcano-sedimentary rocks of the Comondú group, and Miocene marine sediments of the Santa Rosalía basin. On top of these rocks outcrop at least four submarine to subaerial ignimbrites interbedded with marine fossiliferous beds and the lower Pleistocene deposits associated to the Reforma caldera. These deposits are formed by a ignimbrite that shifts to different lithofacies that change gradually their welding, here dubbed basal, transitional, intermediate, and upper (all of then enriched in black fiammes), followed by a pumice-rich, white fiammes, and vitrophyre lithofacies, which are distributed around the 9 km wide caldera and have been associated to the caldera formation episode. Deposits related to post-caldera volcanism are andesite-basaltic lava flows erupted along the caldera rim through localized feeding dikes and andesitic and rhyolitic domes, and scoria cinder cones exposed inside and outside the caldera. On top of these deposits rest the middle Pleistocene Aguajito caldera deposits.

  5. Sur Quatre Methodes Audio-Visuelles (On Four Audiovisual Methods)

    ERIC Educational Resources Information Center

    Porquier, Remy; Vives, Robert

    1974-01-01

    This is a critical examination of four audiovisual methods for the teaching of French as a Foreign Language. The methods have as a common basis the interrelationship of image, dialogue, situation, and give grammar priority over vocabulary. (Text is in French.) (AM)

  6. AIDS Resource Directory and Repertoire de ressources sur le SIDA.

    ERIC Educational Resources Information Center

    Department of National Health and Welfare, Ottawa (Ontario).

    This set of documents presents directories of resources on the topic of Acquired Immune Deficiency Syndrome (AIDS) available in Canada in English and in French. The first section in each directory contains a list of names, addresses, and telephone numbers of organizations from which readers may obtain the listed resources. Resources are then…

  7. Diffusion superficielle sur le cuivre: Influence des marches

    NASA Astrophysics Data System (ADS)

    Cousty, J.; Peix, R.; Perraillon, B.

    1981-06-01

    The surface self-diffusion coefficients of several clean flat copper surfaces have been measured by a radiotracer method. The surface impurity concentration remains lower than 0.01 monolayer and the atomic structure of the surface is not disturbed by the diffusion measurement. At 820 K (0.67 Tm), the following results are obtained on the (100), (111), (110), (310), (511) and (331) faces: (a) The surface diffusion perpendicular to the step array is independent of the step density, (b) The diffusion on the (110), (511) and (331) faces shows a strong anisotropy. This one is attributed to a large mobility of the tracer atoms along the [110] steps. By contrast, [001] step does not affect appreciably the diffusion on the (100) terraces as shown the results obtained on the (310) face. This interpretation is supported by an evaluation of the ratios of the adatom jump frequencies at each step site on these vicinal surfaces, using an atomistic model of surface diffusion.

  8. Influence de la nature et de l'état de conditionnement de l'électrode plane sur la décomposition de SF_6 soumis à des décharges couronne de polarité négative

    NASA Astrophysics Data System (ADS)

    Pradayrol, C.; Casanovas, A. M.; Belarbi, A.; Casanovas, J.

    1995-04-01

    The influence of plane electrode material (aluminium, copper, stainless steel) on the decomposition of dry (no water added ; simeq 200 ppmv H2O) or damp (2000 ppmv H2O) SF6 (P_SF6=300 kPa) subjected to point-to-plane negative corona discharges overline{I}=25 μA ; 0sur la décomposition de SF6 (P_SF6=300 kPa) sec (pas d'eau ajoutée ; simeq 200 ppmv H2O) ou humide (2000 ppmv H2O) soumis à des décharges couronne (géométrie pointe-plan; tension continue de polarité négative ; overline{I}=25 μA ; 0 < Q leq 10 C) a été mise en évidence en dosant les quantités des principaux sous-produits gazeux, SOF2, “SOF4+SO2F2”, S2F{10}, formés. Cette influence est d'autant plus nette que la valeur de la charge transportée et que le taux d'humidité du SF6 sont élevés. L'utilisation d'une électrode en aluminium favorise la formation du “SOF4 + SO2F2” et du S2F{10}, celle d'une électrode en acier inoxydable favorise par contre celle du SOF2. Les différences de composition de la phase gazeuse observées au cours d'un essai et selon le métal sont quasi totalement dues à la passivation de l'électrode plane en cours d'essai. L'utilisation d'électrodes vieillies entraîne une

  9. La prise en charge à long terme de l’asthme chez les enfants inuits et des Premières nations : un outil de transfert du savoir fondé sur les lignes directrices canadiennes pour l’asthme pédiatrique, conçu pour être utilisé par les professionnels de la santé de première ligne qui travaillent dans des communautés isolées

    PubMed Central

    Kovesi, Tom; Giles, Brenda Louise; Pasterkamp, Hans

    L’asthme est un grave problème de santé pour les enfants inuits et des Premières nations. Chez les enfants de moins d’un an, il faut distinguer l’asthme de la bronchiolite virale, anormalement fréquente chez les enfants autochtones du Canada. Chez les enfants de moins de six ans, le diagnostic dépend de la présence de symptômes classiques, de l’absence de caractéristiques atypiques et de la consignation de la réponse au traitement, notamment la réponse rapide et transitoire aux bronchodilatateurs. Chez les enfants plus âgés, il faut, dans la mesure du possible, déterminer la présence d’une obstruction réversible des voies aériennes par spirométrie afin de confirmer le diagnostic, ainsi qu’évaluer et corriger les déclencheurs environnementaux. L’utilisation régulière de corticoïdes en aérosol est la principale mesure à prendre pour maintenir un bon contrôle de l’asthme chez les enfants asthmatiques. Les clients et leur famille devraient recevoir une formation sur l’asthme. Il faut réévaluer régulièrement le contrôle aux visites de suivi dans des centres de santé et rajuster le traitement à la dose la plus basse possible pour le maintien de ce contrôle.

  10. Conversations with Marcgrave: the Origin of Modern Astronomy in the Southern Hemisphere (Spanish Title: Conversando con Marcgrave: El Origen de la Astronomía Moderna en el Hemisferio Sur) Conversando Com Marcgrave: a Origem da Moderna Astronomia no Hemisfério Sul

    NASA Astrophysics Data System (ADS)

    Medeiros, Alexandre; Araújo, Fábio

    2005-12-01

    The year 2004 signals the 400th anniversary of the birth of count Mauricio of Nassau, an important character in the history of Brazil. The present text is related to the period of Dutch domination in Pernambuco. The article attempts to rescue the beginnings of Astronomy study in the South hemisphere. Therefore, we idealized a dramatization of a fictitious interview with German astronomer Georg Marcgrave, who was the constructor of the first astronomical observatory in this hemisphere and the author of the first systematic astronomical observations using telescopes in this side of the world. Our "conversation" with Marcgrave is idealized in the old Recife scenario, a place where he lived in Mauricio of Nassau's period and gathers some fellow teachers who love the teaching of Astronomy. The story, this way, is reported in a possibly light and funny atmosphere. Nevertheless, the conceptual and historical framework presented is based on reliable bibliographical sources pointed out at the end of the text. The sources range from the original book of that scientist, in which a solar eclipse is reported, passing through some other classical texts, such as that of Professor Juliano Moreira, up to more recent sources such as the very influential work of professor John North. Other influential texts about the Dutch period in Brazil, such as the classical works of Charles Boxer, Bouman and Boogaart, among others, are also used in the construction of this pedagogical dramatization, which involves an interesting chapter of the history of Astronomy. El año 2004 marca los 400 años del nacimineto del conde Mauricio de Nassau, un importante personaje de la historia del Brasil. El presente texto está relacionado con el período del dominio holandés en Pernambuco. El artículo intenta rescatar los comienzos del estudio de la Astronomía en el hemisferio Sur. Para esto, ideamos una dramatización de una entrevista ficticia con el astrónomo alemán Georg Marcgrave, constructor del

  11. L'impact d'une simulation sur des dispositifs mobiles et en situation de collaboration sur la comprehension de l'effet photoelectrique au niveau collegial

    NASA Astrophysics Data System (ADS)

    Droui, Mohamed

    The educational innovation itself is sometimes debatable but it is justified when the teachers confront the learning difficulties of their students. In particular, some notions of physics are notoriously hard for students to understand, as is the case for the photoelectric effect which is not often comprehended by the students at the college level. This research tries to determine if, as part of a physics course, the simulation of the photoelectric effect and the use of mobile devices in collaborative situations facilitate an evolution of the student's conceptions about the concept of light. We have proceeded to develop a scenario of collaborative learning by integrating a simulation of the photoelectric effect on handheld devices (Pocket PC). The design of scenario was first influenced by our socioconstructivist vision of learning. We conducted two preliminary studies to complete our scenario of learning and to validate the platform " MobileSim " and the interface of the simulator used in our experiment. The first studies were completed with a simulation on computers and the second with a simulation on Pocket PC. After that, we carried out the experimentation with two groups of students. The control group was assigned to the traditional approach of teaching and the experimental group was assigned to the approach based on the developed scenario of collaborative learning. We have conducted a test twice to assess a conceptual change about the nature of light and about the phenomenon of the photoelectric effect and related concepts. The first test (pre-test) before the students are involved in the course and the second (post-test) after completion of experiments. Our results in the pre-test and post-test were completed by conducting semi-structured individual interviews with all students, by video recordings and recovered traces (on log files or on paper). Students in the experimental group obtained good results in the test compared to those of the control group. We noted an average gain of learning qualified at a moderate level according to Hake (1998). Interview results were used to identify some conceptual difficulties of student learning. Analysis of collected data from video sequences, questionnaires and recovered tracks allowed us to better understand the process of collaborative learning and has revealed that the number and the time of interactions between students are strongly correlated with the gain of learning. At first, this research project is a success in the designing of a learning scenario of a phenomenon as complex as the photoelectric effect and respects many criteria (collaboration, simulation, mobile devices, etc.) that it seemed for us extremely utopian to combine them in an effective learning situation in the classroom. For instance, this scenario could be adapted to the learning of other concepts in physics. It could also be considered for the design of collaborative environments for innovative mobile learning focused on the needs of learners that integrate the technologies at the right time and for the right activity. Keywords : collaborative learning, simulation, mobile learning, conceptual change, photoelectric effect.

  12. Clair de lune sur le port de Boulogne: enquête sur un tableau de Manet, traduction d'un article de Donald W. Olson

    NASA Astrophysics Data System (ADS)

    Borg, Janet

    2016-10-01

    The 19th-century artist Edouard Manet created a spectacular nocturnal painting showing a full Moon over the harbor of Boulogne. Art historians have dated this work to either 1868 or 1869. Calculations of lunar phases, 19th-century maps and photographs of Boulogne harbor, the correspondence of the artist, and other clues allow us to determine a date and precise time when Manet observed this moonlit scene.

  13. Taxonomic Treatment of Solanum Section Petota (Wild Potatoes) in Catálogo de Plantas Vasculares del Cono Sur (Argentina, Chile, Paraguay, Uruguay, y sur del Brasil)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solanum section Petota (Solanaceae), which includes the cultivated potato (Solanum tuberosum) and its wild relatives, contains over 150 wild species distributed from the southwestern U.S.A. (38°N) to central Argentina and adjacent Chile (41°S). This catalog includes all species from the Southern Con...

  14. Le concept de banque d'items et ses implications sur le contenu didactique

    NASA Astrophysics Data System (ADS)

    Tistaert, G.; Mwene, Magabe

    1985-12-01

    The development of the concept of an item bank comes as a reply to the didactic situations which for reasons of efficiency require the storing of a number of susceptible items to be used at any time. Access to the computer makes possible an improvement and rationalization of the management of the item bank. At the same time the extension of the concept has followed two main directions. On the one hand, particular care relates to the adequacy of stored items with the content of learning and it brings about the emergence of a technology of item-editing. On the other hand, psychometric considerations have caused the invariance of essential characteristics of the items. This demands that the items respond to the presupposed models with latent traits. On the basis of theoretical arguments supported by some research findings the final part of the article calls attention to the deep discord among researchers concerning the reliability of the presuppositions of these models in the didactic field. The compromise will probably lead to it that the multidimensionality of items which have a didactic character are admitted.

  15. L'Information sur la Technologie Educative (Information about Educational Technology). Melanges Pedagogiques, 1976.

    ERIC Educational Resources Information Center

    Cembalo, M.

    This paper deals with the problems of information about educational technology among teachers of foreign languages. It investigates the various definitions of educational technology as they appear explicitly in technological publications or implicitly among language teachers. The stress on the systems approach on the researcher's part and the…

  16. Radio-Observaciones del OH EN la Coma del Cometa Halley Desde EL Hemisferio Sur

    NASA Astrophysics Data System (ADS)

    Silva, A. M.; Bajaja, E.; Morras, R.; Cersosimo, J. C.; Martin, M. C.; Arnal, E. M.; Poppel, W. G. L.; Colomb, F. R.; Mazzaro, J.; Olalde, J. C.; Boriakoff, V.; Mirabel, I. F.

    1987-05-01

    Se utilizó una antena de 30 metros del Instituto Argentino de Radioastronomía para observaciones diarias Cf ebrero a abril de 1986) de la transición en 1667 MHz ( λ = 18 cm) del OH en la coma del cometa Halley. De las observaciones realizadas se concluye: 1) El número promedio de moléculas de OH en la coma durante 37 días de observación fue de (8.9±3.5)x1034 moléculas, lo que implica una tasa de producción promedio de OH de 1.8x1029 moléculas seg-1 y consecuentemente una pérdida de masa promedio de 17±6 toneladas seg-1 . Este valor está de acuerdo con las mediciones realizadas por las sondas Vega y Giotto. 2) El monitoreo desde el lAR revela la existencia de variaciones bruscas en los flujos de absorción del OH. Estas variaciones son consistentes con los modelos que representan la producción gaseosa a partir de ejecciones y/o desprendimientos discretos de materia congelada del núcleo. 3) Las variaciones en la densidad de flujo son consistentes con las estimaciones de los tiem- pos de vida medios del H2O y del OH en presencia del campo de radiación solar. 4) Se encuentra una correlación entre la intensidad del flujo absorbido y anisotropías en Ia dinamica de la coma.

  17. Misleading averages on couples j. (French Title: Moyennes trompeuses sur des couples j )

    NASA Astrophysics Data System (ADS)

    Thorel, J. C.

    2010-09-01

    From 1919 to 1920, the equatorial with a 35 cm aperture which is part of the private observatory of Robert JONCKHEERE located at Hem in France undergoes a repair in the workshop of Prin-Gauthier in Paris. During that period, no measure of double stars could be done. Yet, several means are published. We present an analysis of these means and a few others which were established during another period of inactivity in astronomy.

  18. Etudes sur la gravitation: Theories alternatives en 2+1 et 3+1 dimensions

    NASA Astrophysics Data System (ADS)

    Edery, Ariel

    This thesis contains four articles on gravitation of which three have been published in scientific journals and one has been submitted for publication. The four articles divide naturally into two parts. Chapter 1 contains two articles on conformal gravity, a 3 + 1 dimensional theory of gravity and chapter 2 contains two articles on 2 + 1 dimensional topologically massive gravity. Conformal gravity is a metric theory of gravitation which is generally covariant like Einstein gravity but also requires the action to be invariant under conformal transformations of the metric. The novel feature of the solution is a term in the metric that grows linearly with the radius. This linear term, which plays a significant role on large distance scales, can then be used to imitate the effects of the dark matter that is presumed to exist in abundance on galactic scales. In the first and second article, we test the viability of the vacuum solution of conformal gravity. In the first article we calculate the deflection of light due to a spherically symmetric source and obtain a remarkably simple result: besides the usual Einstein deflection, we obtain an extra deflection that increases linearly as the ``impact parameter'' increases (valid for small deflections). In both analyses no dark matter has been included. We explain clearly in our first article the reasons for the discrepency between the two results. In the second article, we study in detail the geometrical properties and the causal structure of the vacuum solution to conformal gravity. At infinity the space-time is not flat but conformal to flat. Through the use of Penrose (conformal) diagrams, we demonstrate that certain space- times, corresponding to certain parameters in the metric, do not allow light to scatter from infinity to infinity. For those which do, we obtain the trajectories and the deflection of light for arbitrary large values of r0 (the radius of closest approach). To simplify the study of gravity, it is common to study a 2 + 1 dimensional model. However, in 2 + 1 dimensions, the analog to Einstein gravity is trivial. The space-time outside sources is flat and particles at rest do not interact. The odd dimensional space-time allows one to include a gravitational Chern-Simons term called a topological mass term because it gives mass to the graviton. In article three and four, we consider localized mass and spin sources in the full non-linear theory. We obtain solutions for both of Vuorio's sectors. In article 3 we demonstrate that delta function sources, while allowed in the linearized theory are not consistent with the full non-linear field equations. In article four, we consider how to embed point sources in Vuorio's cosmological sector and discuss the metric solution for the case when observers are near and far away from the source. (Abstract shortened by UMI.)

  19. Le francais fonde sur la competence, Avance (Competency Based French, Advanced).

    ERIC Educational Resources Information Center

    Dimanche, Maurice

    This instructional guide in French is intended for training Peace Corps volunteers serving in the Central African Republic. It includes 26 topical lessons at the advanced level, each consisting of briefly stated competency objectives and a number of brief, related situational dialogues or texts. Lesson topics include: orienting oneself; discussing…

  20. Uranium series ages of corals from the upper Pleistocene Mulege terrace, Baja California Sur, Mexico

    SciTech Connect

    Ashby, J.R.; Ku, T.L.; Minch, J.A.

    1987-02-01

    Specimens of Porites californica contained in the sediments of upper Pleistocene, +12-m marine terrace deposits developed on the east coast of the Baja California (Mexico) peninsula at Mulege have yielded /sup 239/Th//sup 234/U dates of 124 +/- 5 and 144 +/- 7 ka (+/- 1 sigma). These dates can be assigned to the well-documented late Pleistocene oxygen-isotope stage 5e high sea stand. Differences between the eustatic and present elevations of this terrace indicate average uplift rates since terrace formation of approximately 4 to 5 cm/1000 yr, indicating a relative stability and lack of major vertical deformation since the late Pleistocene. This terrace in the Mulege area can now be correlated with other marine terraces throughout the Baja California peninsula and southern California.

  1. Community Development and Research. Aboriginal Peoples Collection = Developpement Communautaire et Recherches. Collection sur les Autochtones.

    ERIC Educational Resources Information Center

    Ministry of the Solicitor General, Ottawa (Ontario).

    This report provides Canadian Aboriginal communities with information and resources for carrying out participatory action research and applying the results to community development. Presented in English and French, the report is based on a literature review and a 2-day focus group involving 14 community development experts, Aboriginal community…

  2. Sur la nature des absorbeurs dans l'interpretation transactionnelle de la mecanique quantique

    NASA Astrophysics Data System (ADS)

    Boisvert, Jean-Sebastien

    L'interpretation transactionnelle de la mecanique quantique est l'une des plus recentes propositions de description des phenomenes du microcosme. En accord avec les predictions de la mecanique quantique standard, l'interpretation transactionnelle propose une alternative a celle de Copenhague. Son principal avantage est qu'elle permet de visualiser les mecanismes sous-jacents a l'echange d'energie, de quantite de mouvement ou d'autres quantites quantiques entre un emetteur et un absorbeur. Ces echanges sont le resultat, a l'instar de la theorie de l'absorbeur de Wheeler et Feynman, de l'utilisation autant d'ondes avancees que retardees. Bien que l'interpretation transactionnelle n'ait pas attire la plus grande attention scientifique, plusieurs critiques lui ont ete adressees. Dans les annees 1990, differentes experiences a mesure sans interaction ont ete concues. Depuis, il a ete avance que la version originale de l'interpretation transactionnelle pouvait difficilement rendre compte de ce type d'experience et meme qu'elle n'est pas compatible avec le concept d'univers quadridimensionnel. La recherche de ce memoire par article consiste a montrer que lorsque l'on utilise systematiquement l'interpretation transactionnelle en considerant la configuration totale des absorbeurs (incluant l'absorbeur universel), il n'est pas necessaire de faire appel a une hierarchie de transactions comme certains l'ont propose.

  3. Simulation numerique de l'accretion de glace sur une pale d'eolienne

    NASA Astrophysics Data System (ADS)

    Fernando, Villalpando

    The wind energy industry is growing steadily, and an excellent place for the construction of wind farms is northern Quebec. This region has huge wind energy production potential, as the cold temperatures increase air density and with it the available wind energy. However, some issues associated with arctic climates cause production losses on wind farms. Icing conditions occur frequently, as high air humidity and freezing temperatures cause ice to build up on the blades, resulting in wind turbines operating suboptimally. One of the negative consequences of ice accretion is degradation of the blade's aerodynamics, in the form of a decrease in lift and an increase in drag. Also, the ice grows unevenly, which unbalances the blades and induces vibration. This reduces the expected life of some of the turbine components. If the ice accretion continues, the ice can reach a mass that endangers the wind turbine structure, and operation must be suspended in order to prevent mechanical failure. To evaluate the impact of ice on the profits of wind farms, it is important to understand how ice builds up and how much it can affect blade aerodynamics. In response, researchers in the wind energy field have attempted to simulate ice accretion on airfoils in refrigerated wind tunnels. Unfortunately, this is an expensive endeavor, and researchers' budgets are limited. However, ice accretion can be simulated more cost-effectively and with fewer limitations on airfoil size and air speed using numerical methods. Numerical simulation is an approach that can help researchers acquire knowledge in the field of wind energy more quickly. For years, the aviation industry has invested time and money developing computer codes to simulate ice accretion on aircraft wings. Nearly all these codes are restricted to use by aircraft developers, and so they are not accessible to researchers in the wind engineering field. Moreover, these codes have been developed to meet aeronautical industry specifications, which are different from those that must be met in the wind energy industry. Among these differences are the following: wind turbines operate at subsonic speeds; the cords and angles of attack of wind turbine blades are smaller than those of aircraft wings; and a wind turbine can operate with a larger ice mass on its blades than an aircraft can. So, it is important to provide wind energy researchers with tools specifically validated with the operations parameters of a wind turbine. The main goal of this work is to develop a methodology to simulate ice accretion in 2D using Fluent and Matlab, commercial software programs that are available at nearly all research institutions. In this study, we used Gambit, previously the companion tool of Fluent, for mesh generation, and which has now been replaced by ICEM. We decided to stay with Gambit, because we were already deeply involved with the meshing procedure for our simulation of ice accretion at the time Gambit was removed from the market. We validate the methodology with experimental data consisting of iced airfoil contours obtained in a refrigerated wind tunnel using the parameters of actual ice conditions recorded in northern Quebec. This methodology consists of four steps: airfoil meshing, droplet trajectory calculation, thermodynamic model application, and airfoil contour updating. The total simulation time is divided into several time steps, for each of which the four steps are performed until the total time has elapsed. The time step length depends on the icing conditions. (Abstract shortened by UMI.).

  4. Comportement en fatigue et influence de la temperature sur les proprietes en traction du PLA

    NASA Astrophysics Data System (ADS)

    Menard, Claire

    Current environmental issues reduce the use of materials obtained from fossil resources. The usual plastics therefore tend to be replaced by more green polymers such as polylactic acid (PLA), a bio-based and biodegradable polymer. Knowledge on the properties of this material is essential, especially in terms of fatigue strength and influence of temperature on tensile stiffness and strength. In this study, the PLA samples are submitted to monotonic tensile tests, according to ASTM D638-10, at various temperatures between room temperature (23°C) and the glass transition temperature of the material (55-60°C). The results show a decrease of 30% of the modulus of elasticity and 60% of the tensile strength between these two temperatures. This decrease is mainly due to a significant drop in the mechanical properties beyond 50°C. In addition, tensile fatigue tests were conducted at loads rate between 40 and 80% of tensile strength, at room temperature in order to plot the Wohler curve of PLA. The ruptured specimens were finally observed with a scanning electron microscope (SEM) to analyze the failure mechanisms in fatigue of PLA.

  5. [Presidential address at the 20th Journees sur la Fertilite et l'Orthogenie].

    PubMed

    Dourlen-rollier, A M

    1993-01-01

    Recollections of the author's early experiences in French family planning and reflections on the ethical issues and legal status of new fertility technologies are the major topics of this address. The group that was to become le Mouvement francais pour le Planning Familial (MFPF) was founded in 1956 by the author and others and opened its first family planning center in 1961, before contraception became legal. Despite opposition from physicians and Catholic clergy, the MFPF operated 100 centers serving over 100,000 clients by 1965. In 1969 the MFPF began a study of abortion. Despite legalization, the controversy concerning the legitimacy of abortion has not subsided. More recently, the practices of artificial insemination with donor sperm, in vitro fertilization, surrogate mothers, and other medically assisted fertility technologies have raised moral, ethical, and legal questions for all societies. The questions range from the legitimacy of gamete donation to the status of unused embryos. The dissociation of different stages of the reproductive process affects concepts of filiation, paternity and maternity. In the absence of appropriate legislation, it has been left largely to the courts to create a new body of law at this frontier. The review of legislation in France, elsewhere in Europe, and in the U.S. concerning contested filiation in cases of artificial insemination, the legitimacy of insemination of a woman after the death of her spouse, the preservation and donation of embryos, surrogate motherhood, the child's rights to information about his biological parents, and other questions indicate that no consensus has yet emerged concerning the admissibility and legitimacy of specific practices. It would be highly desirable for the European countries to adopt a common legislation in these areas.

  6. Problems and constraints in Philippine municipal fisheries: The case of San Miguel Bay, Camarines Sur

    NASA Astrophysics Data System (ADS)

    Lim, Cristina P.; Matsuda, Yoshiaki; Shigemi, Yukio

    1995-11-01

    The Philippine fisheries accounted for 3.7% of the gross national product at current prices. The sector employed about 990,872 persons. Of the divisions comprising the industry, municipal fisheries continued to contribute the largest share of fish production. However, the sector is beset with problems, many of which are best examplified by the case of San Miguel Bay (SMB). This paper presents the problems and constraints confronting SMB, a common property resource. This bay's open access condition has led to various problems, such as declining fishery resources, depressed socioeconomic conditions, illegal fishing, increasing population, and conflict among resource users. A poor marketing system, low level of fishing technology, fishermen's noncompliance and authorities' lax enforcement of rules and regulations, as well as lack of alternative sources of income further characterize the condition in SMB. Establishment of fishing rights, improvement of the marketing system, provision of alternative sources of income, and improvement of fishing technology were some of the solutions suggested. One major constraint, however, is financial, Comanagement complemented with other management tools has been proposed in addressing the problems in SMB.

  7. [Temporal and spatial distribution of shorebirds (Charadriiformes) at San Ignacio Lagoon, Baja California Sur, Mexico].

    PubMed

    Mendoza, Luis Francisco; Carmona, Roberto

    2013-03-01

    Baja California Peninsula has several wetlands that represent important ecosystems for shorebirds. San Ignacio Lagoon is one of these sites, and supports 10% of the total abundance of shorebirds reported in this Peninsula. Since there is few information about this group in this area, we studied spatial and temporal changes in abundance and distribution of shorebirds in San Ignacio Lagoon. For this, we conducted twelve monthly censuses (October 2007-September 2008) on the entire internal perimeter of the lagoon, which we divided into four areas: two at the North and two at the South. We observed a seasonal pattern, with the lowest abundance in May (1 585 birds) and the highest in October (47 410). The most abundant species were Marbled Godwits (Limosa fedoa; 55% of the total records), Western Sandpipers (Calidris mauri; 23%), and Willet (Tringa semipalmata; 10%). All three species were more abundant in autumn; for both, the Marbled Godwit and Willet, we observed their highest numbers in winter and spring, while the Western Sandpiper showed noticeable oscillations, reaching a maximum in early winter (December). In summer, Marbled Godwit and Willet were the only birds present but in lower numbers. Here present the first records of the Pacific Red Knot (Calidris canutus roselaari) in the area. Bird abundance and species richness were influenced seasonally by migration and spatially by sites in the lagoon. The greatest shorebird abundance was in the South area of the lagoon, probably because of better accessibility to food. Our results allowed the inclusion of San Ignacio Lagoon in the Western Hemisphere Shorebirds Reserve Network (WHSRN) as a site of international importance.

  8. Pleistocene - Holocene Rainfall and Productivity Records in Alfonso Basin Baja California Sur

    NASA Astrophysics Data System (ADS)

    Martinez-Perez, V. D. R.; Gonzalez-Yajimovich, O.; Mejia-Pina, K. G.

    2014-12-01

    Northwesterly winds dominate the southern Gulf of California during most of the year and are associated with high primary productivity due to upwelling. The North American Monsoon causes the wind direction to reverse during the summer months and this brings humid and warms conditions to the region. This climatic temporal-variation generates alternate sedimentation and as a consequence laminated deposits of biogenic and terrigenous composition, preserved by the presence of an oxygen minimum zone. A 5.4 m long piston core (36N) was recovered from Cuenca Alfonso during the DIPAL IV cruise on May 2011. The core was sampled at 1 cm intervals to produce high-resolution proxy records of primary productivity (biogenic opal, total organic carbon and carbonate content) and rainfall (terrigenous content). The core spans from late Pleistocene to the present and it's the longest analyzed record for the basin for the above-mentioned proxies. In general, the proxies show a negative trend towards the present, suggesting a more productive basin and wetter climate in the past. During climatic events like the Bølling-Allerød and the Holocene climatic optimum (HCO) CaCO3 content decreased and opal content increased; suggesting the presence of stronger NW winds and nutrient-richer waters. In contrast, during the Younger Dryas and 8.2 Kyr events the opal content decrease and the CaCO3 increase. At 5.5 KyBP the negative trends in all components intensify, especially during the Medieval Warm Period (MWP). An exception to this occurs during the little ice Age (LIA) where the opal and CaCO3 increase. The organic carbon content increases at the end of the HCO and during the MWP, and decreases during the BA, YD, 8.2 Kyr and LIA. The terrigenous content follows the 24°N summer insolation trend, but shows an increase during warm events (BA, HCO and MWP), and can be attributed to migration of the average position of the Intertropical Convergence Zone driven by variations in solar insolation.

  9. The pioneer woman's view of migraine: Elizabeth Garrett Anderson's thesis "Sur la migraine".

    PubMed

    Wilkinson, M; Isler, H

    1999-01-01

    This is a presentation of a doctoral thesis of 1870. The author was English but the thesis and the examinations were in French. Elizabeth Garrett Anderson, usually referred to as E.G.A., was the first woman in Britain to obtain the title of M.D., but not the first in Europe. Nadeshda Prokofevna Suslova, a Russian, received her M.D. in 1867 in Zurich, the most liberal university at that time, soon to be flooded by female students from Russia. E.G.A. had been applying to the few possible European universities but she settled for Paris after the Empress Eugenie had decided that she should be accepted there. This meant that she could succeed without having to be a Paris resident, just by writing a thesis and passing a series of examinations presided over by Paul Broca. This was important as she was already conducting private and dispensary practice, and could not find a locum (she insisted on a woman). E.G.A. had suffered many setbacks, for being a woman, as such being unacceptable in dissection rooms and operating theatres, and generally in a professional career where women were unheard of. She was finally permitted to receive her medical diploma from the Worshipful Society of Apothecaries of London. She wrote about her thesis: "I have chosen Headache as its subject. I had to find a subject which could be well studied without post-mortem observations, of which I can have but very few in either private or dispensary practice; and I wished also to take a large subject, one that demanded some insight into the harmony that exists between the main physiological functions." Marcia Wilkinson (M.W.), who worked in the Elizabeth Garrett Anderson Hospital in London for 35 years, heard there of E.G.A.'s thesis on migraine and sent for it from Paris. In 1966 she translated it into English from the original French, being interested both in the subject and in the person of this resolute and lucid woman. When H. Isler found the French thesis in the British Library he intended to translate it but, after discussion, we decided on a joint effort (95% of the translation is by M.W.; very few details were changed, and some footnotes added for better understanding). We think that E.G.A.'s text is a classic, showing profound understanding, sound practical advice, and also, in its theoretical part, the limits of neurophysiological knowledge in Paris when Brown-Sequard was "charge des cours" there. We may add that in her various examinations she had to answer questions, in French, on the use of footprints by the police, the general nature of fishes, toxic fishes, electric fishes, cod liver oil, and the secretion of tears. She earned much applause from the public, which consisted of male French students, and the overt appreciation of Paul Broca, head examiner, and Dr Wurtz, the Dean of the Faculte de Médecine. The impact of her thesis in the 19th century was modest. It appears to be rather marginal in the German literature of the early 20th century, but it has imprinted the management of migraine at the City of London Migraine Clinic in the last thirty years. The importance of nutrition, regular meals, regular habits, the need to supplement analgesics with antiemetics, and the treatment of the attack with rest, and great quantities of hot tea, were certainly related to E.G.A.'s doctrine. The internationally prevailing recommendation to give antiemetics, and then only analgesics, as well as the combination of both in one tablet, may thus be traced back to E.G.A. via the teachings of M.W. and Nat Blau.

  10. Modélisation des effets de la photoabsorption K sur l'ADN

    NASA Astrophysics Data System (ADS)

    Vrigneaud, J. M.; Terrissol, M.

    1999-01-01

    Monte Carlo codes were used to simulate the transport of photons and their secondary electrons produced on a linear and hydrated DNA model. Between 150 and 550eV, the variation of photon cross section upon the K-ionisation threshold in C, N, O atoms of DNA is responsible for an increase of the biological effectiveness. We showed that, with the same number of absorbed photons, the distribution of breaks as a function of energy reaches a maximum around 450eV. Nous avons simulé le transport des photons et de leurs électrons secondaires mis en mouvement dans un modèle d'ADN linéaire hydraté, en utilisant la méthode de Monte Carlo. Entre 150 et 550 eV, la variation de section efficace photonique au- dessus du seuil d'ionisation K des atomes C, N, O de l'ADN est responsable d'un accroissement de l'efficacité biologique. Nous avons montré que, pour un même nombre de photons absorbés, la distribution des cassures en fonction de l'énergie passe par un maximum autour de 450 eV.

  11. Coastal dynamics off Cabo Pulmo, Baja California Sur, México

    NASA Astrophysics Data System (ADS)

    Trasviña-Castro, A.; Gonzalez-Rodriguez, E.; Zaitsev, O. V.

    2013-05-01

    Cabo Pulmo is the one of the few coral reefs of the Mexican Pacific. It is located to the north of the Tropic of Cancer (at 23.5° N) and therefore formally in the subtropical region. It is part of the Gulf of California but its location near the tip of the Peninsula pose questions about the exchange of properties with the neighboring Pacific Ocean, some of which will be addressed here. It was declared National Park in 1995. Since then it became a no-take zone and a nature reserve for the preservation of the large variety of species found there. We report results based on meteorological and hydrographic observations as well as current measurements gathered between October 2010 and February 2012. These results include the presence of coastal currents forced by the tide, the wind and remote forcing. We believe the latter are associated, sometimes, to the mesoscale circulation of the entrance to the Gulf of California and, at other times, to coastal jets coming from the interior of the Gulf. We use displacement diagrams to discuss the trends of the residual circulation along the coast. During autumn, winter and even in spring the residual coastal flow is towards the Equator. This is attributed to the influence of the Northwesterly winds that blow over the Gulf of California in these months. It is in summer that the coastal residual circulation exhibits a poleward component being more intense during Southeasterly wind events. Finally, we present evidence of coastal exchange with the Pacific Ocean in the form of an intense jet. This coastal jet flows equatorward past Cabo Pulmo, continues towards the Pacific side of the Peninsula and generates offshore filaments when turning the cape.

  12. Nouvelles Limites sur la Detection Directe de la Matiere Sombre avec l'Experience PICASSO

    NASA Astrophysics Data System (ADS)

    Piro, Marie-Cecile

    Astronomical and cosmological observations strongly suggest the presence of an exotic form of non-relativistic, non-baryonic matter that would represent 26% of the actual energy-matter content of the Universe. This so-called cold dark matter would be composed of Weakly Interactive Massive Particles (WIMP). PICASSO (Project In CAnada to Search for Supersymmetric Objects) aims to detect directly one of the dark matter candidates proposed in the framework of supersymmetric extensions of the standard model : the neutralino. The experiment is installed in the SNOLAB underground laboratory at Sudbury (Ontario) and uses superheated C4F10 droplets detectors, a variant of bubble chamber technique. Phase transitions in the superheated liquids are triggered by 19F recoils caused by the elastic collision with neutralinos and create an acoustic signal which is recorded by piezoelectric sensors. This thesis presents recent progress in PICASSO leading to a substantially increased sensitivity in the search of neutralinos. New fabrication and purification procedures allowed a background reduction of about a factor 10 of the major detectors contamination caused by alpha emitters. Detailed studies allowed to localize these emitters in the detectors. In addition, data analysis efforts were able to improve substantially the discrimination between alpha particle induced events and those created by nuclear recoils. New analysis tools were also developed in order to discriminate between particle induced and non-particle induced events, such as electronic backgrounds and acoustic noise signals. An important new background suppression mechanism at higher temperatures led to the present improved sensitivity of PICASSO at low WIMP masses.

  13. Evolution of the east-central San Jose del Cabo basin, Baja California Sur, Mexico

    NASA Astrophysics Data System (ADS)

    McTeague, M. S.; Umhoefer, P. J.; Schwennicke, T.; Ingle, J. C.; Cortes Martinez, M.

    2006-12-01

    The San Jose del Cabo basin at the southern tip of the Baja California peninsula records the early tectonic evolution of the west side of the Gulf of California. This study focused on the east central margin of the basin. The basal La Calera Formation unconformably overlies Cretaceous granite and consists of conglomerate, pebbly sandstone and conglomerate, and sandstone deposited in alluvial fans and fan-deltas. Deposition of the La Calera Formation was from ca. 9-14 Ma. The lower member of the Trinidad Formation was deposited beginning ca. 9-13 Ma and consists of sandstone, mudstone, and shelly mudstone deposited in nearshore and estuarine environments. These age estimates are based on sedimentation rates and foraminifera and coccoliths from the NN 11A nannozone (7.4 8.6 Ma, GTS 2004). The middle member of the Trinidad Formation consists of deeper water mudstones deposited by turbidity currents and suspension settling in a shelf to slope and conglomerates deposited by submarine debris flows on the shelf. The basin began earlier than previously thought. The oldest marine rocks are ca.9-13 Ma, while sedimentation on the east side began at ca. 9-14 Ma, synchronous with estimates of initiation of offset on the San Jose del Cabo fault. The Zapote fault is a down-to-the-east normal and sinistral-oblique fault that exposes a wedge of granite and older strata in the footwall to the west. The fault was active during sedimentation in the late Miocene and possibly later. The fault divides the study area into an eastern hanging wall subbasin and western footwall subbasin. The eastern subbasin formed an embayment in the eastern margin of the Cabo basin. A regional flooding surface (ca. 8 Ma) can be correlated across the fault that marks a major marine incursion. Depositional systems evolved rapidly from coarse-grained terrestrial systems to fine-grained marine and estuarine systems. The Cabo basin provides an excellent analogue for comparison with offshore basins, which are broadly similar with more faulting in lower strata and fewer or no faulting in upper strata. Offshore seismic data show older, deformed syn-rift strata in half graben overlain by younger, undeformed post-rift strata. The normal faults with 1-5 km spacing cut the basement rock and oldest sedimentary units. The eastern margin of the Cabo basin has older, growth strata cut by the Zapote fault that are overlain by simpler strata. Smaller scale normal faults in the Cabo basin are no longer active while the Cabo fault remains active.

  14. [Pierre Bayen (Chalons-sur-Marne 1725-Paris 1798), organizer of military pharmacy, chemist].

    PubMed

    Labrude, P

    1999-01-01

    Pierre Bayen was born in Chalons in 1725. Pupil in pharmacy in Reims and in Paris, he begun his military career during the "Expedition de Minorque". After the "Guerre de Sept-Ans", named major apothecary, he had to organize the military pharmacy. At the end of his life, he was named general inspector of the medical corps. Member of the College de pharmacie, he devoted a great deal of his time to chemical research and he was named as a member of the Institut national de France when it was created. Bayen is one of the founders of analytical chemistry and of mineralogy. His results on the toxicology of pewter plates were famous. He is one of the precursors of the discovery of oxygen and one of the creators of modern chemistry. Bayen died in Paris in 1798.

  15. Multiculturalism Film and Video Catalogue--1982 = Repertoire des films et videos sur le multiculturalisme--1982.

    ERIC Educational Resources Information Center

    Britt, Margaret, Ed.

    Multiculturalism and cultural pluralism are the foci of this catalog, which lists over 800 films and videos in one or both of Canada's two official languages, French and English. A subject index gives items by title and cross references titles that deal with more than one subject. Subject areas covered are child adoption, architecture, arts and…

  16. Influence de revetements bioactifs sur les cellules endotheliales: Vers des protheses vasculaires non thrombotiques

    NASA Astrophysics Data System (ADS)

    Fadlallah, Hicham

    Developing vascular prostheses of small diameter to replace vessels closed by atherosclerosis remains a challenge because of the risk of thrombosis. Seeding of endothelial cells, which have antithrombogenic properties, is a promising solution, but we must create surfaces which promote their adhesion and retention to resist shear stresses created by the blood flow on the surface. This master's project aimed at investigating the effect of a plasma polymerized coating rich in primary amines (called LP), with or without elements of the extracellular matrix (Fibronectin (FN) or chondroitin sulphate (CS)) on the endothelial cells and hemocompatibility of polyethylene terephthalate (PET). The adhesion, growth and retention of human umbilical vein endothelial cells (HUVECs) on PET and LP, in the presence and absence of FN or CS, have been studied. In addition, platelet adhesion on different surfaces was evaluated by a perfusion test with whole blood, platelets being previously labeled with rhodamine. Finally a double fluorescent labeling (using Cellview Maroon to mark the HUVECs and CD61 antibody for platelets) was developed to study the retention of endothelial cells, under blood flow and verify their non thrombogenic character. The results obtained show that both the LP coating and the adsorbed FN, strongly increase both the cellular adhesion and growth on PET; however they have no additional effect when the two are combined. They also augment cellular retention to surface, but this remains incomplete. Moreover we observed that the plasma coating (LP) greatly increases the thrombogenicity of the surface, with strong platelet adhesion and activation. This thrombogenicity is extremely reduced when endothelial cells cover the surface, but cell loss under the effect of shear produced by the perfusion creates significant areas of platelet adhesion. The grafting of CS on LP also permits good HUVECs adhesion, growth and retention under shear stress on HUVEC, with no difference from the LP alone. In addition, the CS sharply decreases the platelet adhesion, which is found below the value observed for PET. The double cell labeling also showed that cells adhered on LP+CS has an anti-thrombotic phenotype and can resist blood flow. These studies suggest that a coating of CS is a promising strategy for vascular prosthesis given the combination of the good adhesion of endothelial cells and the low thrombogenicity of the underlying surface. Keywords: vascular prostheses, polymers, bioactive coating, thrombogenicity, HUVECs.

  17. Reconnaissance geologic map of part of the San Isidro Quadrangle, Baja California Sur, Mexico

    USGS Publications Warehouse

    McLean, Hugh; Hausback, B.P.; Knapp, J.H.

    1985-01-01

    Mapping was done on aerial photographs and transferred, where possible, to 1:50,000-scale topographic base maps. Areas with roads were field checked; however, in the northeast part of the map area, lack of roads prevented field checks. Previous geologic surveys of parts of the map area were made by horseback in the early 1920's; reports were published by Darton (1921), Heim (1922), and Beal (1948). Subsurface data from petroleum exploration and a geologic map were incorporated in a regional study by Mina (1957). The first radiometric ages of rocks from the map area were published by Gastil and others (1979). Recently determined radiometric ages and chemical analysis of volcanic rocks were reported by Hausback (1984) and by Sawlan and Smith (1984). Our study incorporates geologic mapping with age control based on new radiometric ages as well as paleontology, Flows and tuffs were dated by the K-Ar method. Fossil ages are based on diatom and mollusk assemblages.

  18. Etude des performances de solveurs deterministes sur un coeur rapide a caloporteur sodium

    NASA Astrophysics Data System (ADS)

    Bay, Charlotte

    The reactors of next generation, in particular SFR model, represent a true challenge for current codes and solvers, used mainly for thermic cores. There is no guarantee that their competences could be straight adapted to fast neutron spectrum, or to major design differences. Thus it is necessary to assess the validity of solvers and their potential shortfall in the case of fast neutron reactors. As part of an internship with CEA (France), and at the instigation of EPM Nuclear Institute, this study concerns the following codes : DRAGON/DONJON, ERANOS, PARIS and APOLLO3. The precision assessment has been performed using Monte Carlo code TRIPOLI4. Only core calculation was of interest, namely numerical methods competences in precision and rapidity. Lattice code was not part of the study, that is to say nuclear data, self-shielding, or isotopic compositions. Nor was tackled burnup or time evolution effects. The study consists in two main steps : first evaluating the sensitivity of each solver to calculation parameters, and obtain its optimal calculation set ; then compare their competences in terms of precision and rapidity, by collecting usual quantities (effective multiplication factor, reaction rates map), but also more specific quantities which are crucial to the SFR design, namely control rod worth and sodium void effect. The calculation time is also a key factor. Whatever conclusion or recommendation that could be drawn from this study, they must first of all be applied within similar frameworks, that is to say small fast neutron cores with hexagonal geometry. Eventual adjustments for big cores will have to be demonstrated in developments of this study.

  19. [Pierre Bayen (Chalons-sur-Marne 1725-Paris 1798), organizer of military pharmacy, chemist].

    PubMed

    Labrude, P

    1999-01-01

    Pierre Bayen was born in Chalons in 1725. Pupil in pharmacy in Reims and in Paris, he begun his military career during the "Expedition de Minorque". After the "Guerre de Sept-Ans", named major apothecary, he had to organize the military pharmacy. At the end of his life, he was named general inspector of the medical corps. Member of the College de pharmacie, he devoted a great deal of his time to chemical research and he was named as a member of the Institut national de France when it was created. Bayen is one of the founders of analytical chemistry and of mineralogy. His results on the toxicology of pewter plates were famous. He is one of the precursors of the discovery of oxygen and one of the creators of modern chemistry. Bayen died in Paris in 1798. PMID:11625658

  20. Remarques critques à propos de l'enquête internationale sur la litteratie

    NASA Astrophysics Data System (ADS)

    Manesse, Daniele

    2000-09-01

    There is no doubt of the necessity and importance of an international comparative inquiry concerning literacy. The difficulties involved in such an inquiry are also incontestable. In France the seemingly improbable results of the survey led to the French authorities - who had no doubt been insufficiently vigilant during the earlier stages of the survey - refusing to make the results public. These results highlight a number of methodological flaws that beset this vast undertaking, drawing attention to the need for better procedural precautions and a more adequate notion of literacy. This article presents a synthesis of the counter-investigations demanded by the French authorities, which justify their doubts on the IALS methods, and opens up a debate on the conception of literacy that was applied in the tests.

  1. Oh! I Slipped the Surly Bounds of Earth....and Ran into Space Weather!

    NASA Technical Reports Server (NTRS)

    Golightly, Michael J.

    2004-01-01

    Over the past decade the concept of space weather has been introduced and matured in both the scientific community and popular press. Likewise the concept of space climatology recently also is being advanced. Closely linked to these concepts are their impacts on ground- and space-based technological systems; one such system commonly mentioned is manned space flight exemplified by the Space Shuttle and International Space Station (ISS). From a manned space flight perspective, space weather and space climatology have significant effects on the amount of radiation exposure received by humans in space from the ambient high-energy charged particles present in interplanetary space and trapped in the geomagnetosphere. Whereas the impact of space weather for most technological systems is usually discrete and well correlated in time, the principle impact of space weather and space climatology is to increase the probability of latent cancer formation in thetraveler cohort. In this regard, while space weather may be the dominating factor for a given mission, over the life of a long-term program such as the Space Shuttle or ISS space climatology is the controlling factor of latent cancer risk. Human radiation exposure enhancements associated with space weather disturbances has been a concern among scientist and mission controllers since the inception of manned spaceflight nearly forty years ago. This led NASA to develop, in conjunction with the Environmental Science Services Administration s Space Disturbance Forecast Center and the USAF/AWS, the Solar Particle Alert Network (SPAN)-the foundation of an initial U.S. space weather monitoring and forecasting service. Since Apollo, routine space flight operations have evolved to include the use of space weather and climatology data provided through a world-wide network of operational space weather data services to predict and recommend actions to minimize astronaut radiation exposures. NASA Space Radiation Analysis Group (SRAG) flight controllers use real-time space weather data to detect and assess the impact of solar particle events, outer electron belt enhancements, the formation of pseudo-stable additional trapped radiation belts, and the solar cycle modulation of trapped radiation belts and galactic cosmic rays. Energetic particle data from GOES spacecraft are automatically ingested from NOAA Space Environment Center data servers and used to drive a model for the estimating the exposure to astronauts from solar particle events. While adequate for current manned space flight support, the existing operational space weather support system requires improvements to address the anticipated evolution in both the character of manned missions as well as space flight operations management. Necessary space weather data improvements include: reliably available (near) real-time space weather data on a fixed schedule via redundant access methods that support autonomous data acquisition by computer systems behind enterprise firewalls; and rapid transition of promising research sensors into operational systems.

  2. L'Univers bute sur l'âge du fer

    NASA Astrophysics Data System (ADS)

    Bonnet-Bidaud, J. M.

    2003-07-01

    La découverte d'un quasar très lointain, apparu dans l'Univers très jeune, bien plus chargé en fer que ne le prévoit le Big Bang, sème la perplexité chez les cosmologistes. Faut-il revoir la théorie ou attendre d'autres observations?

  3. Reflexions sur les marqueurs de structuration de la conversation (Considerations on the Structural Markers of Conversation).

    ERIC Educational Resources Information Center

    Auchlin, Antoine

    1981-01-01

    Examines morphemic markers that signal the opening and closing of discourse units, emphasizing their complexity and their central role for a descriptive model of conversation. Then proceeds to analyze their functions within the overall structure of conversation, classifying them according to their properties and uses. Societe Nouvelle Didier…

  4. Le francais fonde sur la competence, Novice (Competency Based French, Novice).

    ERIC Educational Resources Information Center

    Dimanche, Maurice

    This instructional guide in French is intended for training Peace Corps volunteers serving in the Central African Republic. The guide includes 21 topical lessons at the introductory level, each consisting of briefly stated competency objectives and a number of brief, related situational dialogues. Lesson topics include: greetings; introducing…

  5. Rare Social Marketing for Sustainable Fishing in Cortes, Surigao Del Sur, Philippines

    ERIC Educational Resources Information Center

    Day, Brian A.; DeWan, Amielle; Cadiz, Fel Ceasar; Jakosalem-Balane, Joy; Dueñas, Vincent; Trinidad, Pedro M., Jr.

    2014-01-01

    Rare's approach to promoting sustainable fishing through social marketing in the Philippines is exemplified in the Cortes Pride campaign. The Cortes Pride campaign is a social marketing behavior change program that was part of a cohort of 12 similar sustainable fishing campaigns in the Philippines, all of which used a unique blend of social…

  6. A Teacher's Guide to...Awareness Series = Renseignons-nous sur...Serie Sensibilisation.

    ERIC Educational Resources Information Center

    Alberta Dept. of Education, Edmonton. Special Educational Services Branch.

    This document consists of a collection of fourteen information brochures, each issued in both an English and a French version. Each brochure describes the symptoms of a particular disability and provides recommended classroom interventions and additional resources. This collection covers the following disabilities (arranged alphabetically and…

  7. PECVD de composes de silicium sur polymeres: Etude de la premiere phase du depot

    NASA Astrophysics Data System (ADS)

    Dennler, Gilles

    Since their first introduction in the early 90's, transparent barriers against oxygen and/or water vapor permeation through polymers, such as SiO 2, are the object of increasing interest in the food and pharmaceutical packaging industries, and more recently for the encapsulation of organic-based displays. It is now well known that these thin layers possess barrier properties only if they are thicker than a certain critical thickness, dc. For example, dc is around 12 nm in the case of SiO2 on KaptonRTM PI; below this value, the measured "Oxygen Transmission Rate" (OTR, in standard cm3/m2/day/bar) is roughly the same as that of the uncoated polymer. Until now, no detailed research has been carried out to explain this observation, but a hypothesis was proposed in the literature, based on island-like growth structure of the coating for d ≤ dc. According to this hypothesis, the surface energy of the polymeric substrates is so low that the Volmer-Weber (island-coalescence) growth mode occurs. We have aimed to verify this explanation, that is, to study the initial phase of silicon-compound (SiO2 and SiN) growth on four different polymeric substrates, namely polyimide (KaptonRTM PI), polycarbonate (LexanRTM PC), polypropylene (PP), and polyethyleneterephthalate (MylarRTM PET). Three different deposition methods were used, namely reactive evaporation of SiO, radio-frequency (RF) Plasma Enhanced Chemical Vapor Deposition (RF PECVD), and Distributed Electron Cyclotron Resonance (DECR) PECVD. In this latter case, the substrates were placed in three different positions: (i) in the active glow zone, (ii) downstream, and (iii) downstream, but shielded from photon emission (e.g. VUV) from the plasma. Angle-Resolved X-Ray Photoelectron Spectroscopy (ARXPS), Rutherford Backscattering Spectroscopy (RBS), and Scanning Electron Microscopy (SEM), the latter performed after Reactive Ion Etching (RIE) by oxygen plasma, revealed that growth indeed occurs in a Volmer-Weber mode in the case of evaporated films. The island coalescence was observed to occur at d = 1.2 nm, at which point the sticking coefficient of precursor species changes drastically. Finally, we have investigated the presence of an "interphase" between deposited coatings and the polymeric substrate. (Abstract shortened by UMI.)

  8. Integration hybride de transistors a un electron sur un noeud technologique CMOS

    NASA Astrophysics Data System (ADS)

    Jouvet, Nicolas

    This study deals with the hybrid integration of single electron transistors (SET) on a CMOS technology nod. SET devices possess a high potential, especially regarding energy efficiency, but aren't fit to completely replace CMOS components in electrical circuits. However, this problem can be solved through hybrid combination of SETs and MOS, leading to very low operating power circuits, and high integration density. This thesis investigates the use of the nanodamascene process, developed by C. Dubuc, for back-end-of-line (BEOL) SET fabrication, meaning creation of SETs in the oxide encapsulating CMOS devices. The assets the nanodamascene process presents are quite interesting: fabrication of SETs with a large operation margin, high repeatability, and potential for BEOL fabrication. This last point, in particular, makes this process promising. Indeed, it opens the path to the fabrication of numerous layers of SETs, stacked one upon the other, and forming 3D circuits, created on top of 2D CMOS layer. Thus a high gain to existing CMOS wafers could be generated. Devices created through the use of the nanodamascene process, adapted for BEOL SET fabrication, are presented. Limits and improvement perspectives of the technique's transfer are discussed. Electrical characterizations of the devices are also presented. They have demonstrated the created devices functionality, thus validating the successful adaption of the nanodamascene process. They have also allowed for the identification of numerous traps located at the heart of fabricated devices. Fabricated SET devices potential for hybrid SET-CMOS circuits was studied through simulations. Possible architectures showing good potential for early hybrid circuits' realization were identified. Keywords: MOSFET, single electron transistor (SET), nanotechnology, microfabrication, nanodamascene, electrical characterization.

  9. Le Point sur la Pharmacologie des Agents Anesthesiques Chez le Brule Grave

    PubMed Central

    Siah, S.; Ababou, K.; Benziane, H.; El Jaoudi; Bensghir, M.; Bakali, H.; El Wali, A.; Ihrai, I.; Drissi, N.K.

    2008-01-01

    Summary La pharmacologie des agents anesthésiques chez le brûlé est variable et imprévisible. Dans les premières 48 h, il y a une hypovolémie avec chute du débit cardiaque et des fuites plasmatiques. Après 48 h, il y a une hypervolémie avec augmentation du débit cardiaque, hypermétabolisme et la clearance des médicaments est augmentée. Parmi les facteurs de déséquilibre, on retrouve les variations des protéines plasmatiques. Deux protéines sont importantes chez le brûlé grave : l'albumine et l'alpha 1- glycoprotéine. Leur taux varie beaucoup au cours de l'évolution de la brûlure. Les agents anesthésiques dont la liaison avec ces deux protéines est prédominante verront leur pharmacocinétique modifiée. L'anesthésiste-réanimateur du service des brûlés va maîtriser ces notions pharmacologiques pour utiliser à bon escient les agents anesthésiques. PMID:21991108

  10. Animals in Canadian Children's Books (Livres Canadiens sur les Animaux pour les Jeunes).

    ERIC Educational Resources Information Center

    Aubrey, Irene E., Comp.

    French and English annotations for each of the 41 Canadian children's books that involve animals are provided in this bibliography; books listed are in English or French, with some bilingual items, including one in English and Ojibwa. Bibliographic information for each title includes author's name, illustrator's name (if illustrated),…

  11. Sur une ligne aerienne. Carrieres bilinques (On an Airline. Bilingual Careers).

    ERIC Educational Resources Information Center

    Argue, Valerie; Ullmann, Rebecca

    This multimedia kit for French instruction at the secondary level aims to acquaint students with some basic airline terminology in French. One goal of the modular course is to show students the practical link that exists between the study of French and the work world. The kit is represented by a teacher's guide, a student handbook, and a…

  12. Impacts potentiels d'un changement climatique sur le pergelisol dans le nord canadien

    NASA Astrophysics Data System (ADS)

    Obretin, Calin

    This thesis explores the potential impacts of a climate change due to the greenhouse gases on the state and the evolution of the permafrost in the Canadian North. The permafrost represents the half of the Canadian national territory and a change of its current state will echo in all spheres of activity, on the biosphere and on the environment generally. In spite of the evident importance of the subject, there is no precise idea as to how the permafrost will react to the climate change and to what extent the frozen layer will be disrupted. This thesis investigates this problem by using a methodological approach inspired by the Canadian model on the evolution of permafrost (TTOP) coupled with a theoretical approach based on the theory of the complex neuronal systems. The general objective of this thesis is to improve the Canadian model of evolution of permafrost (TTOP-Temperature one the Top Of Permafrost) created by Smith and Riseborough in 1996, its structure of computation, spatial resolution and to determine the state of the permafrost in the study area between 2010 and 2100. The study zone is situated in the Mackenzie Basin (N-W.T) on a north-south transect of 1440 by 720 km. The first objective of the research is to derive maps of the annual values of temperature on the top of the permafrost from 2010 to 2100 by using an improved dynamic model of the evolution of permafrost (TTOP-A). Thereafter, these values are compared with those obtained by Smith and Riseborough (1996). The values of the evolution of air temperature for this period are supplied by the climatic scenarios CGCM32 SRES A1B, CGCM3 SRES A2 and CGCM3 SRES B1. Secondly, this thesis has as an objective the production of the maps of the thickness of permafrost for 2100 with a spatial resolution of 25 km. More exactly, we determine the evolution of the values of thickness of permafrost for the three climatic scenarios mentioned above. Furthermore, the study proposes: i) a new method for downscaling of climate data by using a Determined Stochastic Model, ii) the integration of soil type, iii) the integration of the soil humidity, iv) the integration of the values of thickness of the snow layer and v) the integration of remote sensing data (SSM/I). As a rule, the results obtained by the TTOP-A model reveal that the mean values of temperature at the surface of the permafrost follow closely the values of air temperature and that they are similar to those found by Smith and Riseborough (1996) and Heginbottom and coll. (1995). Also, the differences of the values of temperature on the surface of permafrost between 2010 and 2100 are similar to the values published by the Intergovernmental Panel on Climate Change (IPCC). Concerning the second objective of this thesis, the spatio-temporal dynamics of the permafrost until 2100 demonstrates that, in the study zone, the surface perturbed by global warming will be 37 %, 60 % and 29 % according to the scenarios CGCM3 SRES A1B, CGCM3 SRES A2 and CGCM3 SRES B1 respectively. The permafrost layer inside this zone will disappear by 20 %, 32 % and 18 % according to the scenarios mentioned before. These results lead us to believe that the estimations made by Smith and Riseborough were overvalued in the context of two of three current climates scenarios compared to that of the 1996. Finally, this study demonstrates that the method of downscaling of climate data using the neuronal network within a Determined Stochastic Model gives good results and it represents a reliable option which lends itself to large-scale generalizations. Keywords: permafrost, downscaling, snow, soil humidity, climate scenarios, neuronal network, Determined Stochastic Model, climate change, CGCM3, TTOP. 2The third generation Coupled Global Climate Model [CCCma, 2010].

  13. Impact du réchauffement climatique sur le cycle hydrologique

    NASA Astrophysics Data System (ADS)

    Planton, Serge; Déqué, Michel; Douville, Hervé; Spagnoli, Bruno

    2005-02-01

    At the planetary scale, the models consistently simulate an intensification of the hydrological cycle in a future climate, warmer than the present-day one. However, this intensification might be accompanied by its slowing down due to an increase of the residence time of water vapour in the atmosphere. The impact of climate change on extreme events is even more difficult to evaluate, as results are dependent on methods, emission scenarios and, above all, on models. However, the increase of extreme winter precipitation over northern Europe is a common feature of these evaluations. The hydrological cycle, through the geographical distribution of continental surface humidity, seems to play a key role on the possibility to detect the warming in France. To cite this article: S. Planton et al., C. R. Geoscience 337 (2005).

  14. Quelques considerations sur la traduction medicale et pharmaceutique (Some Considerations in Medical and Pharmaceutical Translation)

    ERIC Educational Resources Information Center

    Sliosberg, A.

    1971-01-01

    Paper presented during the meeting of the Section Presse et Documentation" of the 29th International Congress of Pharmaceutical Science of the International Pharmaceutical Federation, London, September 10, 1969. (VM)

  15. Table ronde sur l'enseignement de la traduction (Round Table on the Instruction of Translation)

    ERIC Educational Resources Information Center

    Delisle, Jean; And Others

    1975-01-01

    This is a discussion on how translator training can be improved. Some conclusions are: that professional societies, universities, and industries which employ translators should work together; that the role of the student should increase; and that universities should cooperate in researching and implementing a more rigorous system of instruction.…

  16. Table ronde sur l'evolution de la traduction (Round Table on the Evolution of Translation)

    ERIC Educational Resources Information Center

    Coty, Jean-Paul; And Others

    1975-01-01

    This is a discussion of the future of translation as a profession. The following are discussed: the quantitative growth of translation; the growth of translation as a technical profession; the influence of this growth on the future of translation training; the influence of translation on Canadian French; machine translation; and the future role of…

  17. Regard critique sur la traduction au Canada (A Critical Look at Translation in Canada)

    ERIC Educational Resources Information Center

    Cardinal, Pierre

    1978-01-01

    A discussion of the history, development and present state of translation, both official and non-official, in Canada. It is shown that translation has become an omnipresent public institution and is at present a linguistic reflection of sociopolitical relations existing between the two linguistic communities. (Text is in French.) (AMH)

  18. Les langues sur le gril argentin (Languages on the Argentine Grill).

    ERIC Educational Resources Information Center

    Cagnolait, Beatriz

    1994-01-01

    A survey of secondary students, French language teachers, managers, and university students in Buenos Aires (Argentina) gives insight into the role of French there and reasons for studying it. Students in general appreciated the language for its aesthetic aspects, managers and teachers for its contribution to culture in general. (MSE)

  19. Points quantiques sur substrat d'indium phosphure: Plate-forme pour des composantes optoelectroniques accordables

    NASA Astrophysics Data System (ADS)

    Allen, Claudine

    InAs/InGaAsP quantum dots were embedded in laser diode structures grown on (100) InP and tunable lasing has been observed between 1.5 mum and 1.7 mum. We first investigated the dynamics of charge carriers and photons in these laser diodes. It was found that the carriers confined in the quantum dots have discrete energy states like those of a bidimensional harmonic oscillator. The interaction between charge carriers and electromagnetic waves was analyzed through the electrical susceptibility. This has confirmed the possibility of wave amplification if the charge carrier population in the quantum dots is inverted, eventually leading to lasing if enough current is injected. Next, we have studied experimentally three different laser diode structures; their spectral properties and their super linear relation between emitted optical power and injected current demonstrate lasing characteristics. The best optoelectronic performance was obtained for the structure with the deepest charge carrier confinement potential and largest density of quantum dots, but an increase of this second parameter doesn't guarantee an improvement of the performance. At room temperature, a laser threshold current density of 1.1 kA/cm 2 and an external quantum differential efficiency of 9.4% have been measured for this laser diode structure as well as a good internal quantum efficiency of 25% approximately. This efficiency decrease from internal to external was attributed to high internal photon losses with a coefficient of 28 cm-1. Typical increase of the threshold current density with temperature was verified with characteristic temperatures between 52 K and 121 K, but this characteristic temperature abnormally increased above 180 K for two of the three laser diode structures. Spectral tuning potential was assessed by studying the effect of temperature and length of the laser diodes on their lasing wavelength. Promising results incited us to set up an external cavity tunable laser based on our quantum dot laser diodes. A tuning range of 110 nm centered at 1580 nm was reached in a spectral region important for applications of optoelectronic devices in the field of telecommunications.

  20. Reflexions sur L'Evolution de L'Enseignement de la Biologie en Afrique.

    ERIC Educational Resources Information Center

    Sasson, A.

    1980-01-01

    Reviews the main stages of the evolution of biology teaching in Africa. Discusses the UNESCO pilot project, the teaching aids produced for English- and French-speaking countries of Africa, and the "Teacher's Guide on the Biology of Human Populations" and projects needs for further assistance. (CS)

  1. Quelques facteurs sociaux agissant sur la formation permanente et l'education informelle en Algerie

    NASA Astrophysics Data System (ADS)

    Haddab, Mustapha

    1994-05-01

    This article attempts an analysis of the conditions under which a certain degree of educational pluralism has begun, tentatively, to be seen in Algeria in association with the political and socio-economic changes that have taken place since 1988. After a long period of centralism codified in the National Charter of 1976, during which the public education system had become all but the only provider of education, in demand largely on account of the diplomas and certificates which it awarded, various social factors (including growth in unemployment among young people and those with qualifications, development of voluntary associations, inflexibility of public schools, various effects of the "language conflict" on the educational system, etc.) have since led to the appearance of varying educational activities. Some of these make up for the inadequacy of the public schools; others, less well established, respond to the emergence of the need for "lifelong education" or provide complementary training for social groups which may have a political or religious motivation. These tendencies are limited to the development of voluntary associations in Algeria.

  2. Policy for Heritage Language Instruction = Politique sur l'enseignement des langues ancestrales.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education and Training, Winnipeg.

    Policy established by the Manitoba (Canada) provincial government to inform the development and implementation of heritage language programs is outlined. Introductory sections provide background on the history of heritage language instruction, foreign language instruction, and language of instruction in Manitoba public schools. A brief discussion…

  3. The SU(r)2 string functions as q-diagrams

    NASA Astrophysics Data System (ADS)

    Genish, Arel; Gepner, Doron

    2016-06-01

    A generalized Roger Ramanujan (GRR) type expression for the characters of A-type parafermions has been a long standing puzzle dating back to conjectures made regarding some of the characters in the 90s. Not long ago we have put forward such GRR type identities describing any of the level two ADE-type generalized parafermions characters at any rank. These characters are the string functions of simply laced Lie algebras at level two, as such, they are also of mathematical interest. In our last joint paper we presented the complete derivation for the D-type generalized parafermions characters identities. Here we generalize our previous discussion and prove the GRR type expressions for the characters of A-type generalized parafermions. To prove the A-type GRR conjecture we study further the q-diagrams, introduced in our last joint paper, and examine the diagrammatic interpretations of known identities among them Slater identities for the characters of the first minimal model, which is the Ising model, and the Bailey lemma.

  4. La photoémission VUV résolue en temps sur des solides isolants

    NASA Astrophysics Data System (ADS)

    Geoffroy, G.; Guizard, S.; Belsky, A.; Constant, E.; Martin, P.; Mével, E.

    2003-06-01

    L'objectif de ce travail expérimental est l'étude de la dynamique des processus de relaxations électroniques dans les solides, et en particulier dans les diélectriques. La technique la plus couramment employée pour étudier ces phénomènes est la photoémission résolue en temps, l'aide d'impulsions laser ultra-brèves. Une première impulsion excite les électrons du solide, et une seconde impulsion provoque l'ionisation d'une partie de ces électrons. La mesure de l'énergie cinétique de ces photoélectrons en fonction du retard entre les impulsions pompe et sonde donne une image directe de l'évolution de leur distribution énergétique. Cette technique très puissante a déjà été utilisée pour étudier les cinétiques de relaxation dans les semi-conducteurs et les métaux. En effet les énergies de photons nécessaires aux excitations électroniques correspondent aux longueurs d'onde d'émission des lasers femtosecondes les plus courants. Les harmoniques d'ordres élevés obtenues à partir de lasers femtosecondcs intenses permettent d'étendre ces études à des matériaux isolants à grande bande interdite. Les résultats d'une étude systématique de la relaxation d'électrons de grande énergie (\\cong30 eV) dans différents diélectriques (SiO2, CeF3), réalisée avec la source d'harmoniques du laboratoire CELIA sont comparés et discutés.

  5. The ambient acoustic environment in Laguna San Ignacio, Baja California Sur, Mexico.

    PubMed

    Seger, Kerri D; Thode, Aaron M; Swartz, Steven L; Urbán, Jorge R

    2015-11-01

    Each winter gray whales (Eschrichtius robustus) breed and calve in Laguna San Ignacio, Mexico, where a robust, yet regulated, whale-watching industry exists. Baseline acoustic environments in LSI's three zones were monitored between 2008 and 2013, in anticipation of a new road being paved that will potentially increase tourist activity to this relatively isolated location. These zones diff