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Sample records for playas del sudeste

  1. Monitoring Playa Hydrology using LANDSAT Imagery

    NASA Astrophysics Data System (ADS)

    Young, C. B.; Pradhananga, A.

    2004-12-01

    Playa lakes are wetland basins found across the Great Plains. These ephemeral lakes serve as habitat for migrating waterfowl and act as concentrated recharge points for groundwater aquifers. Playas are generally small but number in the tens of thousands, making them a significant component of the ecology and hydrology of the Great Plains. The shear number of playas makes this system difficult to study. Satellite remote sensing, however, can be used to monitor playa hydrology over broad space and time scales. This study demonstrates the use of a four-image LANDSAT sequence to study a cluster of playas in Beaver County, Oklahoma. A simple water budget model is developed to predict aggregate playa water surface area for the study area.

  2. Geochemical exploration for uranium in playas.

    USGS Publications Warehouse

    Leach, D.L.; Puchlik, K.P.; Glanzman, R.K.

    1980-01-01

    Although playa sediments at spring discharge areas contain as much as 58 ppm U, evaporation and mobilization processes were found to limit their potential as resources of U. Other metals, however, such as Zn, W, and Au may have a geochemical signature in the playas. There are certain conditions that would make some playas more favorable for the accumulation of U: 1) the presence of precursor carbonate-rich saline lakes; 2) nearby U-rich source rocks; 3) restricted groundwater discharge into the playa; 4) localized precipitation mechanisms or phases in the playa;5) large drainage basins and adequate precipitation; and 6) stability of a hydrologically closed basin for a long period of time.- from Authors

  3. Astronomy at Nabta Playa, Southern Egypt

    NASA Astrophysics Data System (ADS)

    McKim Malville, J.

    Nabta Playa may contain the oldest human-made features with astronomical alignments in Egypt. In the Late and Terminal Neolithic (7,500-5,400 BP), nomadic pastoralists built a ceremonial center on the western shore of Nabta Playa, consisting of some 30 complex megalithic structures, stone circles, and lines of megaliths crossing the playa. The megaliths may once have aligned with Arcturus, the Belt of Orion, Sirius, and α Cen. Reorientations of the northern set of megaliths suggest a response to precession. Elaborate burials at the nearby cemetery at Gebel Ramlah indicate the nomads consisted of Mediterranean and sub-Saharan populations with little social stratification.

  4. Microbial Signatures In Sulfate-Rich Playas

    NASA Astrophysics Data System (ADS)

    Glamoclija, M.; Steele, A.; Starke, V.; Zeidan, M.; Potochniak, S.; Sirisena, K.; Widanagamage, I. H.

    2016-05-01

    Microbes that live in playas represent organisms able to cope with transient environments, ranging from fresh to hyper-saline water settings and from wet to dry. We will try to identify mineral and chemical signatures of their presence.

  5. Evolution of playa basins on the Texas High Plains--Evidence from playa-basin fills

    SciTech Connect

    Hovorka, S.D. . Bureau of Economic Geology)

    1993-02-01

    Heterogeneous sediments in playa basins document the evolution of shallow depressions on the Texas High Plains surface through the late Quaternary. The suite of sediments encountered in playa-lake basins differs from the typical lithologies of the Blackwater Draw Formation in upland areas. The upland Blackwater Draw Formation has red-brown clayey silt containing root casts, well-developed soil fabrics, and abundant pedogenic carbonate nodules. Cores drilled in playa basins encountered a repetitive suite of gray clay, well-sorted fine to medium sand, and laminated sand and silt associated with clay drapes and beds of pedogenic calcite pebbles. The gray clay was deposited in ephemeral lakes similar to modern playa lakes. Small clams and drab colors extending downward from these deposits demonstrate ponding. Soil fabrics, soil slickensides, deep clay-filled cracks, and root tubules within the clayey beds indicate desiccation and exposure of the lake floor. Well-sorted sand layers represent episodic migration of sand sheets across the playa. Laminated sand and silt beds are interpreted as delta deposits that formed at the mouths of draws. Minimal soil formation indicates relatively rapid deposition during delta progradation. The suite of playa sediments interfingers with upland Blackwater Draw facies, documenting the temporal equivalence of playa and upland deposition and expansion and contraction of the lake within the playa basin. Complex patterns of oxidation, reduction, and precipitation and dissolution of calcite document the interaction between ground water and sediments.

  6. Dynamics of salt playa polygons

    NASA Astrophysics Data System (ADS)

    Goehring, L.; Fourrière, A.

    2014-12-01

    In natural salt playa or in evaporation pools for the salt extraction industry, one can sometimes see surprising regular structures formed by ridges of salt. These ridges connect together to form a self-organized network of polygons one to two meters in diameter, which we call salt polygons. Here we propose a mechanism based on porous media convection of salty water in soil to explain the formation and the scaling of the salt polygons. Surface evaporation causes a steady upward flow of salty water, which can cause precipitation near the surface. A vertical salt gradient then builds up in the porous soil, with heavy salt-saturated water lying over the less salty source water. This can drive convection when a threshold is reached, given by a critical Rayleigh number of about 7. We suggest that the salt polygons are the surface expression of the porous medium convection, with salt crystallizing along the positions of the convective downwellings. To study this instability directly, we developed a 2D analogue experiment using a Hele-Shaw cell filled with a porous medium saturated with a salt solution and heated from above. We perform a linear stability analysis of this system, and find that it is unstable to convection, with a most unstable wavelength that is set by a balance between salt diffusion and water evaporation. The Rayleigh number in our experiment is controlled by the particle size of our model soil, and the evaporation rate. We obtain results that scale with the observation of natural salt polygons. Using dye, we observe the convective movement of salty water and find downwelling convective plumes underneath the spots where surface salt ridges form, as shown in the attached figure.

  7. The restless rock of Racetrack Playa

    NASA Astrophysics Data System (ADS)

    Jackson, Brian; Lorenz, Ralph; Norris, Richard

    2015-07-01

    Tucked away in California's Death Valley National Park, the flat basin known as Racetrack Playa is littered with stones that seem to migrate across the landscape. But how do they do it? Brian Jackson describes how he and collaborators Ralph Lorenz and Richard Norris solved a long-standing mystery.

  8. Playa basin development, southern High Plains, Texas and New Mexico

    SciTech Connect

    Gustavson, T.C. ); Holliday, V.T. )

    1992-01-01

    More than 20,000 playa basins have formed on fine-grained eolian sediments of the Quaternary Blackwater Draw and Tertiary Ogallala Formations on the High Plains of TX and NM. Numerous hypotheses have been proposed for the development of playa basins: (1) subsidence due to dissolution of underlying Permian bedded salt, (2) dissolution of soil carbonate and piping of clastic sediment into the subsurface, (3) animal activity, and (4) deflation. Evidence of eolian processes includes lee dunes and straightened shorelines on the eastern and southern margins of many playas. Lee dunes, which occur on the eastern side of ca 15% of playa basins and contain sediment deflated from adjacent playas, are cresentic to oval in plain view and typically account for 15--40% of the volume of the playa basin. Quaternary fossil biotas and buried calcic soils indicate that grasslands and semi-arid to aid climatic conditions prevailed as these basins formed. Evidence of fluviolacustrine processes in playa basins includes centripetal drainage leading to fan deltas at playa margins and preserved deltaic and lacustrine sediments. Playa basins expanded as fluvial processes eroded basin slopes and carried sediment to the basin floor where, during periods of minimal vegetation cover, loose sediment was removed by deflation. Other processes that played secondary roles in the development of certain playa basins include subsidence induced by dissolution of deeply buried Permian salt, dissolution of soil carbonate and piping, and animal activity. Two small lake basins in Gray County, TX, occur above strata affected by dissolution-induced subsidence. Dissolution of soil carbonate was observed in exposures and cores of strata underlying playa basins. Cattle, and in the past vast numbers of migrating buffalo, destroy soil crusts in dry playas, making these sediments more susceptible to deflation, and carry sediment out of flooded playas on their hooves.

  9. 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

  10. Grass buffers for playas in agricultural landscapes: A literature synthesis

    USGS Publications Warehouse

    Melcher, Cynthia P.; Skagen, Susan K.

    2005-01-01

    Future research should entail multiple-scale approaches at regional, wetland-complex, and individual watershed scales. Information needs include direct measures of buffer effectiveness in ‘real-world’ systems, refinement and field tests of buffer-effectiveness models, how buffers may affect floral and faunal communities of playas, and basic ecological information on playa function and playa wildlife ecology. Understanding how wildlife communities respond to patch size and habitat fragmentation is crucial for addressing questions regarding habitat quality of grass buffers in playa systems.

  11. Topography, surface features, and flooding of Rogers Lake playa, California

    USGS Publications Warehouse

    Dinehart, Randal L.; McPherson, Kelly R.

    1998-01-01

    Rogers Lake is a desert playa used as a military airport for Edwards Air Force Base in the Antelope Valley of southern California. Previous measurements of land subsidence and ground-water levels in the study area indicated that ground-water pumping induced tensional stresses in the playa, which were sporadically relieved through the formation of long cracks. Drying of the sediments beneath the playa also may have accelerated the natural formation of giant desiccation polygons. When water flows across the playa, the cracks erode into fissures of sufficient width and depth to endanger traffic on the playa. Topographic surveys of the playa were made to derive a contour map that would allow examination of erosive flow paths. Crack networks were surveyed in selected areas during 1995 and compared with cracks visible in aerial photographs taken in 1990. Crack networks remained visible in their positions following several inundations of the playa. The density of the crack networks increased in all of the selected areas.

  12. Evaporation from groundwater discharge playas, Estancia Basin, central New Mexico

    USGS Publications Warehouse

    Menking, Kirsten M.; Anderson, Roger Y.; Brunsell, Nathaniel A.; Allen, Bruce D.; Ellwein, Amy L.; Loveland, Thomas A.; Hostetler, Steven W.

    2000-01-01

    Bowen ratio meteorological stations have been deployed to measure rates of evaporation from groundwater discharge playas and from an adjacent vegetated bench in the Estancia Basin, in central New Mexico. The playas are remnants of late Pleistocene pluvial Lake Estancia and are discharge areas for groundwater originating as precipitation in the adjacent Manzano Mts. They also accumulate water during local precipitation events. Evaporation is calculated from measured values of net radiation, soil heat flux, atmospheric temperature, and relative humidity. Evaporation rates are strongly dependent on the presence or absence of standing water in the playas, with rates increasing more than 600% after individual rainstorms. Evaporation at site E-12, in the southeastern part of the playa Complex, measured 74 cm over a yearlong period from mid-1997 through mid-1998. This value compares favorably to earlier estimates from northern Estancia playas, but is nearly three times greater than evaporation at a similar playa in western Utah. Differences in geographical position, salt crust composition, and physical properties may explain some of the difference in evaporation rates in these two geographic regions.

  13. Dynamics of playa lakes in the Texas High Plains

    NASA Technical Reports Server (NTRS)

    Reeves, C. C., Jr. (Principal Investigator)

    1972-01-01

    The author has identified the following significant results. Three small playa lake basins on the southern High Plains, Texas, have been examined by geologists, pedologists, hydrologists, and botanists to establish ground truth for correlation with ERTS-1 imagery. Although the sites are recognizable, details of the three playa basins are too small, at present resolution, to be accurately determined by the available MSS imagery. However, a fourth study site, consisting of a dual playa complex approximately 5 miles long in a basin of 9 square miles, does resolve available imagery allowing accurate measurement of water fluctuations and water depth. Of the available MSS imagery, Band 5 is the most usable. Definition of Band 4 is less due to reduced tonal contrast. The greatest tonal contrast appears on Band 6 and Band 7 between dry land and water areas. Band 6 is particularly good for defining large water areas, Band 7 being best for small lake basins, and Band 5 for growing fields.

  14. Spatial distribution and morphology of sediments in Texas Southern High Plains playa wetlands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Playas are depressional geomorphic features on the U.S. High Plains. About 20,000 Southern High Plains playa wet¬lands serve as runoff catchment basins, which are thought to be focal points of Ogallala aquifer recharge. Sediments in playas can alter biodiversity services, impede aquifer recharge, an...

  15. Spatial Distribution and Morphology of Sediments in Texas Southern High Plains Playa Wetlands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Playas are depressional geomorphic features on the U.S. High Plains and about 20,000 Southern High Plains playa wetlands serve as runoff catchment basins, which are thought to be focal points of Ogallala aquifer recharge. Sediments in playas can alter biodiversity services, impede aquifer recharge,...

  16. Geomorphic and hydrologic controls of dust emissions during drought from Yellow Lake playa, West Texas, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research on the factors that control dust emissions from playas has revealed a number of complex geomorphic and hydrologic factors, yet there are few measurements of dust emissions from playas during drought or low-emission seasons. Deflation of Yellow Lake, a saline playa in West Texas, produces sa...

  17. Comments on Racetrack playa: Rocks moved by wind alone

    NASA Astrophysics Data System (ADS)

    Sanz-Montero, M. E.; Cabestrero, Ó.; Rodríguez-Aranda, J. P.

    2016-03-01

    The mechanisms by which rocks move across the beds of playa lakes leaving tracks continue to be debated (Sanz-Montero and Rodríguez-Aranda, 2013; Norris et al., 2014; Sanz-Montero et al., 2015a,b; Baumgardner and Shaffer, 2015; Jones and Hooke, 2015). In this regard, the article by Jones and Hooke (Aeolian Research 19, 2015) is particularly interesting since it provides a description of these mechanisms by R. Jones who, during a storm event in 1972, was probably the first person to witness movement of rocks. The dominant meteorological conditions described by Jones during the period when the tracks were formed are, significantly, rather similar to those previously described by Clements (1952) at Little Bonnie Claire Playa (Nevada, USA). The storm conditions referred to in the article also coincide with the observations, measurements and deductions made by Sanz-Montero and Rodríguez-Aranda (2013) and Sanz-Montero et al. (2015a,b) at Altillo Chica playa lake, Central Spain. Furthermore, we were able to carry out an on-site analysis of the sedimentary structures at Racetrack playa in June 2015, allowing us to verify the similarity of the features present at both sites. Together with the important role played by gusty winds in the formation of the tracks, all the above mentioned studies point to the presence of a thin veneer of water, just a few millimeters deep, in the area of the playa lake where the rock movements occur. However, Jones and Hooke (2015) disregard the force exerted by moving water and analyze the coefficient of friction assuming that the rocks are moved by wind alone. We offer an alternative explanation for the movement of rocks both at Racetrack and Altillo Chica playa lake which considers not only the wind but also the role played by moving water in conjunction with other parameters which modify the erosion thresholds (rocks acting as obstacles) and reduce friction (benthic microorganisms).

  18. Genetic differentiation among cottontails from isolated playa basins.

    PubMed

    Van den Bussche, R A; Hamilton, M J; Chesser, R K; Scribner, K T

    1987-11-30

    Protein variation in 182 Sylvilagus floridanus from 19 playa basins in Castro Co., Texas was examined using starch-gel electrophoresis. Heterozygote deficiencies were noted for all populations. This heterozygote deficiency may be due to differential selection against heterozygous individuals over the winter months. Results of F-statistics indicated a significant degree of population differentiation at six loci. Nei's genetic distance between populations ranged from 0.20 to 0.388 and a significant association between genetic distance and linear geographic distance among playas was found. These results suggest that genetic exchange and long-distance dispersal may be hindered by expanses of unsuitable habitat. PMID:3504804

  19. Estimating Recharge through Playa Lakes to the Southern High Plains Aquifer

    NASA Astrophysics Data System (ADS)

    Rainwater, K.; Ganesan, G.; Gitz, D.; Zartman, R.; Hudnall, W.; Smith, L.

    2009-12-01

    In the Southern High Plains of Texas, it is accepted that focused recharge to the High Plains Aquifer (locally known as the Ogallala) occurs through over 20,000 playa lakes, which are local depressions that collect storm runoff. The amount and rate of recharge is not precisely known, and the impact of the land use surrounding each playa lake on the amount of runoff has not been quantified. Each playa exists within its own watershed, and many of those are cultivated, while others are surrounded by native grassland or conservation reserve program (CRP) lands. The amount of sediments entering most playas following cultivation has been substantial, but whether this erosion has had a harmful influence on recharge is unknown. Changing recharge rates can also impact the playa ecosystems that are pivotal to many types of local wildlife. Improved understanding of playa recharge is necessary for proper management strategies for long-term survivability of the Ogallala aquifer. Over the last four years, the research team selected and instrumented 30 playas (10 counties, one cropland playa, one native grassland playa, one CRP playa in each) for observation of their water budgets. To quantify recharge in each playa, data collection includes sufficient weather instrumentation to determine local precipitation and free water evaporation, as well as water level monitoring in the playa lake. The depth/area/volume relationship for each playa was developed by local GPS surveying. Between rainfall/runoff events, seepage through the playa bottom is calculated as the difference between the change in the volume of water stored in the playa and the calculated free water evaporation. The research team hopes to keep the instrumentation operational for as long as possible, hopefully several years, to observe enough inundation events to characterize a range of behaviors in the different playa basins. In this presentation, initial water budget analyses for several of the initially instrumented

  20. Dust emission from wet and dry playas in the Mojave Desert, USA

    USGS Publications Warehouse

    Reynolds, R.L.; Yount, J.C.; Reheis, M.; Goldstein, H.; Chavez, P., Jr.; Fulton, R.; Whitney, J.; Fuller, C.; Forester, R.M.

    2007-01-01

    The interactions between playa hydrology and playa-surface sediments are important factors that control the type and amount of dust emitted from playas as a result of wind erosion. The production of evaporite minerals during evaporative loss of near-surface ground water results in both the creation and maintenance of several centimeters or more of loose sediment on and near the surfaces of wet playas. Observations that characterize the texture, mineralogic composition and hardness of playa surfaces at Franklin Lake, Soda Lake and West Cronese Lake playas in the Mojave Desert (California), along with imaging of dust emission using automated digital photography, indicate that these kinds of surface sediment are highly susceptible to dust emission. The surfaces of wet playas are dynamic - surface texture and sediment availability to wind erosion change rapidly, primarily in response to fluctuations in water-table depth, rainfall and rates of evaporation. In contrast, dry playas are characterized by ground water at depth. Consequently, dry playas commonly have hard surfaces that produce little or no dust if undisturbed except for transient silt and clay deposited on surfaces by wind and water. Although not the dominant type of global dust, salt-rich dusts from wet playas may be important with respect to radiative properties of dust plumes, atmospheric chemistry, windborne nutrients and human health.

  1. Land use and conservation reserve program effects on the persistence of playa wetlands in the High Plains.

    PubMed

    Daniel, Dale W; Smith, Loren M; Haukos, David A; Johnson, Lacrecia A; McMurry, Scott T

    2014-04-15

    Watershed cultivation and subsequent soil erosion remains the greatest threat to the service provisioning of playa wetlands in the High Plains. The U.S. Department of Agriculture's (USDA) Conservation Reserve Program (CRP) plants perennial vegetation cover on cultivated lands including playa watersheds, and therefore, the program influences sediment deposition and accumulation in playas. Our objective was to measure the effects of the CRP on sediment deposition by comparing sediment depth and present/historic size characteristics in 258 playas among three High-Plains subregions (northern, central, and southern) and the three dominant watershed types: cropland, CRP, and native grassland. Sediment depth and resultant volume loss for CRP playas were 40% and 57% lower than cropland playas, but 68% and 76% greater than playas in native grassland. Playas in CRP had remaining volumes exceeding those of cropland playas. Grassland playas had nearly three times more original playa volume and 122% greater wetland area than CRP playas. Overall, playas were larger in the south than other subregions. Sediment depth was also three times greater in the south than the north, which resulted in southern playas losing twice as much total volume as northern playas. However, the larger southern playas provide more remaining volume per playa than those in other subregions. The results of this study demonstrate the importance of proper watershed management in preserving playa wetland ecosystem service provisioning in the High Plains. Furthermore, we identify regional differences in playas that may influence management decisions and provide valuable insight to conservation practitioners trying to maximize wetland services with limited resources. PMID:24635683

  2. Dynamics of Playa lakes in the Texas High Plains

    NASA Technical Reports Server (NTRS)

    Reeves, C. C., Jr.

    1974-01-01

    Three small playa lake basins on the Texas High Plains were originally selected as ERTS-1 test sites to attempt correlation of ERTS-1 imagery with the water balance ecosystem and geology/morphology of the lake basins. The 5-mile long large Double Lakes playa complex was also instrumented as an alternate test site. Analysis of bands 6 and 7 of ERTS-1 MSS imagery shows that lake basins as small as 200 m in diameter (+ or - 10 acres) can be reliably classified as being wet or dry, thus supplying the methodology for a rapid, periodic census of surface water. A cost/benefit analysis reveals that the use of MSS imagery for such a census results in a 66 to 200-fold cost reduction when compared to the costs of using other conventional methods.

  3. Geohydrology and evapotranspiration at Franklin Lake Playa, Inyo County, California

    SciTech Connect

    1990-12-01

    Franklin Lake playa is one of the principal discharge areas of the Furnace Creek Ranch-Alkali Flat ground-water-flow system in southern Nevada and adjacent California. Yucca Mountain, Nevada, located within this flow system, is being evaluated by the US Department of Energy to determine its suitability as a potential site for a high-level nuclear-waste repository. To assist the US Department of Energy with its evaluation of the Yucca Mountain site, the US Geological Survey developed a parameter-estimation model of the Furnace Creek Ranch-Alkali Flat ground-water-flow system. Results from sensitivity analyses made using the parameter-estimation model indicated that simulated rates of evapotranspiration at Franklin Lake playa had the largest effect on the calculation of transmissivity values at Yucca Mountain of all the model-boundary conditions and, therefore, that evapotranspiration required careful definition. 72 refs., 59 figs., 26 tab.

  4. Geohydrology and evapotranspiration at Franklin Lake playa, Inyo County, California

    SciTech Connect

    Czarnecki, J.B.

    1997-12-31

    Franklin Lake playa is one of the principal discharge areas of the Furnace Creek Ranch-Alkali Flat ground-water-flow system in southern Nevada and adjacent California. Yucca Mountain, Nevada, located within this flow system, is being evaluated by the US Department of Energy to determine its suitability as a potential site for a high-level nuclear-waste repository. To assist the U.S. Department of Energy with its evaluation of the Yucca Mountain site, the US Geological Survey developed a parameter-estimation model of the Furnace Creek Ranch-Alkali Flat ground-water-flow system. Results from sensitivity analyses made using the parameter-estimation model indicated that simulated rates of evapotranspiration at Franklin Lake playa had the largest effect on the calculation of transmissivity values at Yucca Mountain of all the model-boundary conditions and, therefore, that evapotranspiration required careful definition.

  5. Bacterial succession within an ephemeral hypereutrophic mojave desert playa lake

    USGS Publications Warehouse

    Navarro, J.B.; Moser, D.P.; Flores, A.; Ross, C.; Rosen, Michael R.; Dong, H.; Zhang, G.; Hedlund, B.P.

    2009-01-01

    Ephemerally wet playas are conspicuous features of arid landscapes worldwide; however, they have not been well studied as habitats for microorganisms. We tracked the geochemistry and microbial community in Silver Lake playa, California, over one flooding/desiccation cycle following the unusually wet winter of 2004-2005. Over the course of the study, total dissolved solids increased by 10-fold and pH increased by nearly one unit. As the lake contracted and temperatures increased over the summer, a moderately dense planktonic population of 1 ?????106 cells ml-1 of culturable heterotrophs was replaced by a dense population of more than 1????????109 cells ml-1, which appears to be the highest concentration of culturable planktonic heterotrophs reported in any natural aquatic ecosystem. This correlated with a dramatic depletion of nitrate as well as changes in the microbial community, as assessed by small subunit ribosomal RNA gene sequencing of bacterial isolates and uncultivated clones. Isolates from the early-phase flooded playa were primarily Actinobacteria, Firmicutes, and Bacteroidetes, yet clone libraries were dominated by Betaproteobacteria and yet uncultivated Actinobacteria. Isolates from the late-flooded phase ecosystem were predominantly Proteobacteria, particularly alkalitolerant isolates of Rhodobaca, Porphyrobacter, Hydrogenophaga, Alishwenella, and relatives of Thauera; however, clone libraries were composed almost entirely of Synechococcus (Cyanobacteria). A sample taken after the playa surface was completely desiccated contained diverse culturable Actinobacteria typically isolated from soils. In total, 205 isolates and 166 clones represented 82 and 44 species-level groups, respectively, including a wide diversity of Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, Gemmatimonadetes, Acidobacteria, and Cyanobacteria. ?? 2008 Springer Science+Business Media, LLC.

  6. Clay Minerals in Playas of the Mojave Desert, California.

    PubMed

    Droste, J B

    1959-07-10

    Montmorillonite, illite, chlorite, and kaolinite in the playas of southern California are traceable directly to the source areas surrounding the basins. No evidence found in this investigation suggests that these clay minerals are unstable in the sodic or calcic saline lake environment, but this conclusion may not be directly applied to marine evaporite facies where the minerals are rich in potassium and magnesium. PMID:17738603

  7. Bacterial succession within an ephemeral hypereutrophic Mojave Desert playa Lake.

    PubMed

    Navarro, Jason B; Moser, Duane P; Flores, Andrea; Ross, Christian; Rosen, Michael R; Dong, Hailiang; Zhang, Gengxin; Hedlund, Brian P

    2009-02-01

    Ephemerally wet playas are conspicuous features of arid landscapes worldwide; however, they have not been well studied as habitats for microorganisms. We tracked the geochemistry and microbial community in Silver Lake playa, California, over one flooding/desiccation cycle following the unusually wet winter of 2004-2005. Over the course of the study, total dissolved solids increased by approximately 10-fold and pH increased by nearly one unit. As the lake contracted and temperatures increased over the summer, a moderately dense planktonic population of approximately 1x10(6) cells ml(-1) of culturable heterotrophs was replaced by a dense population of more than 1x10(9) cells ml(-1), which appears to be the highest concentration of culturable planktonic heterotrophs reported in any natural aquatic ecosystem. This correlated with a dramatic depletion of nitrate as well as changes in the microbial community, as assessed by small subunit ribosomal RNA gene sequencing of bacterial isolates and uncultivated clones. Isolates from the early-phase flooded playa were primarily Actinobacteria, Firmicutes, and Bacteroidetes, yet clone libraries were dominated by Betaproteobacteria and yet uncultivated Actinobacteria. Isolates from the late-flooded phase ecosystem were predominantly Proteobacteria, particularly alkalitolerant isolates of Rhodobaca, Porphyrobacter, Hydrogenophaga, Alishwenella, and relatives of Thauera; however, clone libraries were composed almost entirely of Synechococcus (Cyanobacteria). A sample taken after the playa surface was completely desiccated contained diverse culturable Actinobacteria typically isolated from soils. In total, 205 isolates and 166 clones represented 82 and 44 species-level groups, respectively, including a wide diversity of Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, Gemmatimonadetes, Acidobacteria, and Cyanobacteria. PMID:18758846

  8. A modern subtropical playa complex: Salina de Ambargasta, central Argentina

    NASA Astrophysics Data System (ADS)

    Zanor, Gabriela A.; Piovano, Eduardo L.; Ariztegui, Daniel; Vallet-Coulomb, Christine

    2012-04-01

    Salina de Ambargasta is a playa located at mid latitudes in central Argentina (29 °S-64 °W). Because of its hydrological behaviour, this playa complex can be subdivided into a closed system "sensu-stricto" and an "open-like system" due to the presence of a seasonal outflow. Geomorphological and sedimentological features enable the separation of the Ambargasta playa into well-defined western, eastern and northern zones, where aeolian processes, groundwater supply and surface inflow, respectively, define distinctive sedimentary environments and typical processes of deposition. The following depositional settings were recognized: (1) alluvial fan; (2) sandflat; (3) springs; (4) dunes and palaeo-dune field; (5) dry mudflat; (6) capillary mudflat; (7) ephemeral saline lake (includes saline mudflat and salt pan). The dry mudflat is present at the highest topographical zone, where the groundwater influence is less important and only intermittent ponds are present. In the capillary mudflat, evaporite sedimentation is limited to the development of efflorescence by evaporative pumping. The ephemeral saline lake, placed in the lowermost topographical region, alternates cycles of lake expansion and contraction responding to inter-annual hydrological variability as well as to seasonal variability. Lake expansion takes place during early austral summer (December-March), while continuous evaporation of brine leads to the growth of halite crystals during late summer. Sodium chloride-type brines result from both chemical fractionation as evaporation increases and salt dissolution. The isotopic compositions of surficial and underground waters (δ18O and δ2H) indicate that lake waters become isotopically enriched during summer when evaporation plays a significant role in the playa complex.

  9. Development rates of Late Quaternary soils, Silver Lake Playa, California

    USGS Publications Warehouse

    Reheis, M.C.; Harden, J.W.; McFadden, L.D.; Shroba, R.R.

    1989-01-01

    Soils formed on alluvial fan deposits that range in age from about 35 000 to 200 yr BP near Silver Lake playa in the Mojave Desert permit study of the rates of soil development in an arid, hyperthermic climate. Field-described properties of soils were quantified and analyzed using a soil development index that combines properties and horizon thicknesses. Pedogenic CaCO3 (as indicated by color), pH increase, and dry consistence appear to change with age at linear rates, whereas rubification appears to change at a logarithmic rate. The linear rates are best attributed to the progressive accumulation of CaCO3- and salt-rich eolian dust derived from the playa and other mnore distant sources. The total-texture values of soils on fans older than 10 000 yr BP are similar, which suggests that playas in this area may have been wet enough to restrict the availability of fines from these sources for many thousands of years prior to 10 000 yr BP. Equations derived from regressions of soil age and properties can be used to estimate ages of undated, lithologically similar deposits in similar climates and geomorphic settings. -from Authors

  10. MTI Thermal Bands Calibration at Ivanpah Playa with a Fourier Transform Infrared Spectrometer

    SciTech Connect

    Villa-Aleman, E.

    2001-06-27

    The Savannah River Technology Center (SRTC) is currently calibrating the Multispectral Thermal Imager (MTI) satellite sponsored by the Department of Energy. The reflective bands of the MTI satellite are calibrated in desert playas such as Ivanpah Playa in the Nevada/California border. The five MTI thermal bands are calibrated with targets of known emissivity and temperature such as power plant heated lakes. In order to accomplish a full calibration at the desert playas, a Fourier transform infrared spectrometer was used to measure soil surface radiance and temperature during the satellite overpass. The results obtained with the mobile FTIR during the ground truth campaign at Ivanpah Playa will be presented.

  11. Dust emissions from undisturbed and disturbed, crusted playa surfaces: cattle trampling effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dry playa lake beds can be significant sources of fine dust emission. This study used a portable field wind tunnel to quantify the PM10 emissions from a bare, fine-textured playa surface located in the far northern Chihuahua Desert. The natural, undisturbed crust and its subjection to two levels of ...

  12. Influence of conservation practices on ecosystem services provided by playas in the High Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The majority of the High Plains region is comprised of shortgrass prairie. Within this shortgrass prairie region, playas are the dominant wetland type. Playas are shallow depressional recharge wetlands, each existing within their own individual catchments. This is also one of the most intensively...

  13. Dust Emissions from Undisturbed and Disturbed, Crusted Playa Surfaces: Cattle Trampling Effect

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dry playa lake beds can be a significant source of fine dust emissions during high wind events in arid and semiarid landscapes. The physical and chemical properties of the playa surface control the amount and properties of the dust emitted. In this study, we use a field wind tunnel to quantify the...

  14. Preliminary results of dust emission data from Yellow Lake Playa, West Texas, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated the relationship between groundwater and dust emission rates at Yellow Lake, a saline “wet” playa in West Texas with a long history of wind erosion. Deflation of the playa surface has generated lunettes composed of silt-clay aggregates and gypsum. Saltation sensors indicate that most...

  15. Field study of spatial variability in unsaturated flow beneath and adjacent to playas

    NASA Astrophysics Data System (ADS)

    Scanlon, Bridget R.; Goldsmith, Richard S.

    We quantified unsaturated flow beneath playa and adjacent interplaya settings at a site in the Southern High Plains (United States) to resolve issues related to where and how water moves through the unsaturated zone. This is the first study in which the data density (39 boreholes) and the variety of techniques used (physical, chemical, and isotopic) were sufficient to quantify spatial variability in unsaturated flow. Water contents, water potentials, and tritium concentrations were much higher and chloride concentrations were much lower beneath playas than in interplaya settings, which indicated that playas focus recharge. These results refute previous hypotheses that playas act as evaporation pans or that recharge is restricted to the annular region around playas. Water fluxes estimated from environmental tracers ranged from 60 to 120mmyr-1 beneath playas and were <=0.1mmyr-1 during the past 2000-5000 years beneath natural interplaya areas not subjected to ponding. To evaluate the apparent inconsistency between high recharge rates and thick clay layers beneath playas, we applied bromide and FD&C blue dye to evaluate flow processes. These applied tracer experiments showed preferential flow along roots and desiccation cracks through structured clays in the shallow subsurface in playas.

  16. Lithium and strontium isotopic systematics in playas in Nevada, USA: constraints on the origin of lithium

    NASA Astrophysics Data System (ADS)

    Araoka, Daisuke; Kawahata, Hodaka; Takagi, Tetsuichi; Watanabe, Yasushi; Nishimura, Koshi; Nishio, Yoshiro

    2014-03-01

    Lithium-rich brine in playas is a major raw material for lithium production. Recently, lithium isotopic ratios (δ7Li) have been identified as a tool for investigating water-rock interactions. Thus, to constrain the origin of lithium in playas by the use of its isotopes, we conducted leaching experiments on various lacustrine sediment and evaporite deposit samples collected from playas in Nevada, USA. We determined lithium and strontium isotopic ratios and contents and trace element contents of the leachate, estimated the initial δ7Li values in the water flowing into the playas, and examined the origin of lithium in playas by comparison with δ7Li values of the possible sources. In samples from the playas, δ7Li values show some variation, reflecting differences both in isotopic fractionation during mineral formation and in initial δ7Li value in water flowing into each playa. However, all δ7Li values in this study are much lower than those in river water and groundwater samples from around the world, but they are close to those of volcanic rocks. Considering the temperature dependence of lithium isotopic fractionation between solid and fluid, these results indicate that the lithium concentrated in playas in Nevada was supplied mainly through high-temperature water-rock interaction associated with local hydrothermal activity and not directly by low-temperature weathering of surface materials. This study, which is the first to report lithium isotopic compositions in playas, demonstrates that δ7Li may be a useful tracer for determining the origin of lithium and evaluating its accumulation processes in playas.

  17. Macropolygon morphology, development, and classification on North Panamint and Eureka playas, Death Valley National Park CA

    NASA Astrophysics Data System (ADS)

    Messina, Paula; Stoffer, Phil; Smith, Ward C.

    2005-12-01

    Panamint and Eureka playas, both located within Death Valley National Park, exhibit a host of surficial features including fissures, pits, mounds, and plant-covered ridges, representing topographic highs and lows that vary up to 2 m of relief from the playa surface. Aerial photographs reveal that these linear strands often converge to form polygons, ranging in length from several meters to nearly a kilometer. These features stand out in generally dark contrast to the brighter intervening expanse of flat, plant-free, desiccated mud of the typical playa surface. Ground-truth mapping of playa features with differential GPS (Global Positioning System) was conducted in 1999 (North Panamint Valley) and 2002 (Eureka Valley). High-resolution digital maps reveal that both playas possess macropolygons of similar scale and geometry, and that fissures may be categorized into one of two genetic groups: (1) shore-parallel or playa-interior desiccation and shrinkage; and (2) tectonic-induced cracks. Early investigations of these features in Eureka Valley concluded that their origin may have been related to agricultural activity by paleo-Indian communities. Although human artifacts are abundant at each locale, there is no evidence to support the inference that surface features reported on Eureka Playa are anthropogenic in origin. Our assumptions into the genesis of polygons on playas is based on our fortuitous experience of witnessing a fissure in the process of formation on Panamint Playa after a flash flood (May 1999); our observations revealed a paradox that saturation of the upper playa crusts contributes to the establishment of some desiccation features. Follow-up visits to the same feature over 2 yrs' time are a foundation for insight into the evolution and possible longevity of these features.

  18. Macropolygon morphology, development, and classification on North Panamint and Eureka playas, Death Valley National Park CA

    USGS Publications Warehouse

    Messina, P.; Stoffer, P.; Smith, W.C.

    2005-01-01

    Panamint and Eureka playas, both located within Death Valley National Park, exhibit a host of surficial features including fissures, pits, mounds, and plant-covered ridges, representing topographic highs and lows that vary up to 2 m of relief from the playa surface. Aerial photographs reveal that these linear strands often converge to form polygons, ranging in length from several meters to nearly a kilometer. These features stand out in generally dark contrast to the brighter intervening expanse of flat, plant-free, desiccated mud of the typical playa surface. Ground-truth mapping of playa features with differential GPS (Global Positioning System) was conducted in 1999 (North Panamint Valley) and 2002 (Eureka Valley). High-resolution digital maps reveal that both playas possess macropolygons of similar scale and geometry, and that fissures may be categorized into one of two genetic groups: (1) shore-parallel or playa-interior desiccation and shrinkage; and (2) tectonic-induced cracks. Early investigations of these features in Eureka Valley concluded that their origin may have been related to agricultural activity by paleo-Indian communities. Although human artifacts are abundant at each locale, there is no evidence to support the inference that surface features reported on Eureka Playa are anthropogenic in origin. Our assumptions into the genesis of polygons on playas is based on our fortuitous experience of witnessing a fissure in the process of formation on Panamint Playa after a flash flood (May 1999); our observations revealed a paradox that saturation of the upper playa crusts contributes to the establishment of some desiccation features. Follow-up visits to the same feature over 2 yrs' time are a foundation for insight into the evolution and possible longevity of these features. ?? 2005 Elsevier B.V. All rights reserved.

  19. A change-detection application on the evolution of Kahak playa (South Khorasan province, Iran)

    NASA Astrophysics Data System (ADS)

    Rezaei Moghaddam, Mohammad Hossein; Saghafi, Mahdi

    2006-12-01

    Kahak salt playa in South Khorasan province of Iran, have special geomorphological characteristics by the presence of ephemeral saline lakes, wetlands, salt crusts, surface accumulations of salt and zones of patterned ground. Salt crusts in the soil surface are unique in the region and have laminated horizons in the playa soil. Soil-surface salt accumulations are dominated by NaCl and gypsum. It has been found that distribution of chemical soluble is not uniform across the playa landscape, and this result influences on the variety form of patterned ground. In this study, the percent changes in some of the chemical elements such as NaCl, gypsum and also brine extent have been calculated in the playa. Indicating changes in Kahak salt playa is the main aim of this study by using remote sensing and GIS techniques. In this paper, techniques such as spectral un-mixing, maximum likelihood classification, band rationing, fuzzy classification and correlation relationships are discussed. This contribution presents modeling of temporal and spatial changes of salinity and playa developing using combined approaches that incorporate different data-fusion and data-integration techniques for two periods of date. Furthermore, percent changes in the surface-patterned ground of the playa have been calculated using texture and pattern analysis of the PCA1. Results have revealed that, in the playa developing, chemical materials such as sodium, NaCl, gypsum and also brine extent are positively correlated with each other and the most increased changes are related to gypsum and the most decreased changes are related to the NaCl. Also changes in the amount of agricultural area in the playa-lakes margin, show low effects in the desertification process.

  20. Dynamics of Playa Lakes in the Texas High Plains

    NASA Technical Reports Server (NTRS)

    Reeves, C. C., Jr. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. This project is designed to correlate ERTS-1 satellite imagery signatures with the water balance ecosystem and geology of select playa lake basins in West Texas. The principal work consisted of monitoring the weather instruments, the measurement of water levels and water depths examination of MSS imagery, and measurement of water and mud areas by use of ESIAC (Electronic Satellite Image Analysis Console) at Stanford Research Center, Menlo Park, California. A cost/benefit analysis, comparing the use of ERTS-1 data to more conventionally secured data, revealed that use of ERTS-1 data for such a survey reduces cost from $2.00 to $0.03/square mile.

  1. Grass buffers for playas in agricultural landscapes: An annotated bibliography

    USGS Publications Warehouse

    Melcher, Cynthia P.; Skagen, Susan K.

    2005-01-01

    References on best management practices (BMPs) for agricultural lands were included because certain BMPs are crucial for informing decisions about buffer design/ effectiveness and overall playa ecology. We also included various papers that increase the spectrum of time over which buffer theories and practices have evolved. An unannotated section lists references that we did not prioritize for annotation and references that may be helpful but were beyond the scope of this document. Finally, we provide notes on conversations we had with scientists, land managers, and other buffer experts whom we consulted, and their contact information. We conclude the bibliography with appendices of common and scientific names of birds and plants and acronyms used in both the bibliography. In the annotations, italicized text signifies our own editorial remarks. Readers should also note that much of the work on buffers has been designed using English units of measure rather than metrics; in most cases, their results have been converted to metrics for publication, explaining the seemingly odd or irregular buffer widths and other parameters reported.

  2. Playa lake and sheetflood deposits of the Upper Cretaceous Jindong Formation, Korea: Occurrences and palaeoenvironments

    NASA Astrophysics Data System (ADS)

    Paik, I. S.; Kim, H. J.

    2006-05-01

    Lake model of the Upper Cretaceous Jindong Formation in Korea was established on the basis of sedimentological and palaeobiological records of the playa lake and sheetflood deposits and their palaeoenvironmental implications. The playa lake and sheetflood deposits of the Jindong Formation are characterized by the common presence of traces of vanished evaporites, complicated polygonal desiccation cracks and rainprints, the pedogenic carbonate development, and the preservation of invertebrate traces and dinosaur and bird tracks. The traces of vanished evaporites including halite and sulphate evaporite occur as evaporite pseudopmorphs and moulds. The occurrence of all of the evaporite minerals as traces suggests that flooding stages persisted much longer than evaporation and desiccation stages. Invertebrates, birds, and dinosaurs inhabited the playa lake environment of the Upper Cretaceous Jindong Lake. The Jindong Lake formed by the combination of humid source area and arid depositional site due to an orographic effect in fault-bounded basin. Extensive development of the playa lake and sheetflood deposits with evaporite mineral casts and very limited association of shoreline deposits in the Jindong Formation are characteristic of closed lake, and the Jindong Lake is compared to a lake formed in partly drained closed basin. The aggradation of mudflat deposits indicates continued subsidence of the basin and continuation of an underfilled lake basin. The Jindong Lake expanded and stabilized as a playa lake surrounded by dry to saline mudflats, and palaeoclimate and subsidence rates changed little throughout the period of the Jindong Lake development.

  3. Lithostratigraphy and geochronology of fills in small playa basins on the Southern High Plains, United States

    SciTech Connect

    Holliday, V.T.; Hovorka, S.D.; Gustavson, T.C.

    1996-08-01

    Playa basins are small depressions (typically <=1.5 km{sup 2}) on the Southern High Plains of northwestern Texas and eastern New Mexico. There are about 25000 playas in the region; they lie on the Blackwater Draw Formation (Pleistocene), a widespread eolin deposit, and locally on the Ogallala Formation (Miocene-Pliocene). Understanding the lithostratigraphy and chronostratigraphy of the fill in the basins is important because it should (1) provide clues to the origin and evolution of playas, which have been long debated; (2) yield a paleoenvironmental record for the region; and (3) aid in understanding the history and future of the regional aquifer because playas are the principal source of recharge. Data from 19 playa basins, combined with published data from 4 other basins, show that the basin fill is composed of six distinctive facies: (1) lacustrine mud; (2) lacustrine carbonate; (3) lacustrine delta deposits; (4) eolian sand and silt; (5) eolian loam; and (6) accretionary eolian deposits (Blackwater Draw Formation). Dating is based on radiocarbon ages from the fill in 12 basins and from lunettes adjacent to 5 basins. All dated basins were present at the end of the Pleistocene and some were present in some form throughout the Pleistocene. These lithostratigraphic and chronostratigraphic relationships show that some basins have a prolonged history as depressions. 96 refs., 7 figs., 3 tabs.

  4. Modeling sediment accumulation in North American playa wetlands in response to climate change, 1940-2100

    USGS Publications Warehouse

    Burris, Lucy; Skagen, Susan K.

    2013-01-01

    Playa wetlands on the west-central Great Plains of North America are vulnerable to sediment infilling from upland agriculture, putting at risk several important ecosystem services as well as essential habitats and food resources of diverse wetland-dependent biota. Climate predictions for this semi-arid area indicate reduced precipitation which may alter rates of erosion, runoff, and sedimentation of playas. We forecasted erosion rates, sediment depths, and resultant playa wetland depths across the west-central Great Plains and examined the relative roles of land use context and projected changes in precipitation in the sedimentation process. We estimated erosion with the Revised Universal Soil Loss Equation (RUSLE) using historic values and downscaled precipitation predictions from three general circulation models and three emissions scenarios. We calibrated RUSLE results using field sediment measurements. RUSLE is appealing for regional scale modeling because it uses climate forecasts with monthly resolution and other widely available values including soil texture, slope and land use. Sediment accumulation rates will continue near historic levels through 2070 and will be sufficient to cause most playas (if not already filled) to fill with sediment within the next 100 years in the absence of mitigation. Land use surrounding the playa, whether grassland or tilled cropland, is more influential in sediment accumulation than climate-driven precipitation change.

  5. Tectonic constraints and hydrological functioning in several playa-lakes from southern Spain

    NASA Astrophysics Data System (ADS)

    Rodríguez-Rodríguez, Miguel; Moral, Francisco; Díaz-Azpiroz, Manuel; Pérez-Valera, Fernando

    2013-04-01

    We have selected three main wetland systems located in southern Spain to describe the tectonic factors that have given rise to the formation of closed depressions originating playa - lakes in a semi arid climate context. The three wetlands are located in the provinces of Córdoba, Seville and Cádiz (Andalusia). The low-permeability of the materials - often Triassic clays and marls - forming the closed depressions generates a local groundwater flow system that coincides with the surface watershed. The main surface water inputs comes from the watershed (runoff) and the main groundwater inputs comes from a local aquifer placed at the bottom of the closed depression. Water outputs are mainly due to the evaporation from the playa-lake and ET from the vegetation. This hypothesis is coherent with the geological origin and is supported by hydrological observation, numerical modelling and and surface-groundwater daily monitoring of time series in some of the studied playas. The southernmost playa lake studied is Medina playa-lake, hosted in the northern edge of a 1748 ha closed basin (Cádiz). The main structure that has generated the northern edge is an antiform with a core of Triassic and Miocene sediments and an upper part formed by alluvial conglomerates. This antiform acts as a barrier to the natural runoff, flowing to the north, remaining the cause for the genesis of the endorheic basin that leads to the establishment of the playa-lake. The Conde playa-lake (Córdoba province) is also placed in the northern edge of its 1109 ha closed basin. In this case, clay, gypsum-rich matrix tectonic mélange with a NE-SW orientation has been described in this sector. This melange define a non-continuous NE-SW uplift ridge, which acts as a natural barrier to the northwardly directed runoff originating the Conde playa-lake formation Finally, in Seville province, there is a large (251 km2) continental inner depression, formerly a Quaternary inland delta, that has lead to the

  6. Microbial mats in playa lakes and other saline habitats: Early Mars analog?

    NASA Technical Reports Server (NTRS)

    Bauld, John

    1989-01-01

    Microbial mats are cohesive benthic microbial communities which inhabit various Terra (Earth-based) environments including the marine littoral and both permanent and ephemeral (playa) saline lakes. Certain geomorphological features of Mars, such as the Margaritifer Sinus, were interpreted as ancient, dried playa lakes, presumably formed before or during the transition to the present Mars climate. Studies of modern Terran examples suggest that microbial mats on early Mars would have had the capacity to survive and propagate under environmental constraints that would have included irregularly fluctuating regimes of water activity and high ultraviolet flux. Assuming that such microbial communities did indeed inhabit early Mars, their detection during the Mars Rover Sample Return (MRSR) mission depends upon the presence of features diagnostic of the prior existence of these communities or their component microbes or, as an aid to choosing suitable landing, local exploration or sampling sites, geomorphological, sedimentological or chemical features characteristic of their playa lake habitats. Examination of modern Terran playas (e.g., the Lake Eyre basin) shows that these features span several orders of magnitude in size. While stromatolites are commonly centimeter-meter scale features, bioherms or fields of individuals may extend to larger scales. Preservation of organic matter (mats and microbes) would be favored in topographic lows such as channels or ponds of high salinity, particularly those receiving silica-rich groundwaters. These areas are likely to be located near former zones of groundwater emergence and/or where flood channels entered the paleo-playa. Fossil playa systems which may aid in assessing the applicability of this particular Mars analog include the Cambrian Observatory Hill Beds of the Officer Basin and the Eocene Wilkins Peak Member of the Green River Formation.

  7. Effectiveness of vegetation buffers surrounding playa wetlands at contaminant and sediment amelioration.

    PubMed

    Haukos, David A; Johnson, Lacrecia A; Smith, Loren M; McMurry, Scott T

    2016-10-01

    Playa wetlands, the dominant hydrological feature of the semi-arid U.S. High Plains providing critical ecosystem services, are being lost and degraded due to anthropogenic alterations of the short-grass prairie landscape. The primary process contributing to the loss of playas is filling of the wetland through accumulation of soil eroded and transported by precipitation from surrounding cultivated watersheds. We evaluated effectiveness of vegetative buffers surrounding playas in removing metals, nutrients, and dissolved/suspended sediments from precipitation runoff. Storm water runoff was collected at 10-m intervals in three buffer types (native grass, fallow cropland, and Conservation Reserve Program). Buffer type differed in plant composition, but not in maximum percent removal of contaminants. Within the initial 60 m from a cultivated field, vegetation buffers of all types removed >50% of all measured contaminants, including 83% of total suspended solids (TSS) and 58% of total dissolved solids (TDS). Buffers removed an average of 70% of P and 78% of N to reduce nutrients entering the playa. Mean maximum percent removal for metals ranged from 56% of Na to 87% of Cr. Maximum removal was typically at 50 m of buffer width. Measures of TSS were correlated with all measures of metals and nutrients except for N, which was correlated with TDS. Any buffer type with >80% vegetation cover and 30-60 m in width would maximize contaminant removal from precipitation runoff while ensuring that playas would continue to function hydrologically to provide ecosystem services. Watershed management to minimize erosion and creations of vegetation buffers could be economical and effective conservation tools for playa wetlands. PMID:27423768

  8. The utilization of ERTS-1-generated photographs in the evaluation of the Iranian playas as potential locations for economic and engineering development. [hydrology and morphology of playa soils

    NASA Technical Reports Server (NTRS)

    Krinsley, D. B. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Hydrologic inventories, throughout the year, were made in interior basins that have not been measured previously because of their inaccessibility. Interior basins during the last ERTS-1 year (August 1972 to August 1973) had driest ground conditions in late September 1972 and had wettest ground conditions from March through May 1973, depending upon location. Bearing strengths of playa soils can be inferred from the changing hydrologic conditions through the seasons as recorded by ERTS-1, with prior ground control. Slight differences in salt-crust morphology and in moisture contest of playa soils can be greatly enhanced by rationing and stretching techniques. Differences in water area and silt content can be enhanced by using a three-stage photographic masking technique employing bands 4, 5, and 7.

  9. Water-Chemistry Evolution and Modeling of Radionuclide Sorption and Cation Exchange during Inundation of Frenchman Flat Playa

    SciTech Connect

    Hershey, Ronald; Cablk, Mary; LeFebre, Karen; Fenstermaker, Lynn; Decker, David

    2013-08-01

    Atmospheric tests and other experiments with nuclear materials were conducted on the Frenchman Flat playa at the Nevada National Security Site, Nye County, Nevada; residual radionuclides are known to exist in Frenchman Flat playa soils. Although the playa is typically dry, extended periods of winter precipitation or large single-event rainstorms can inundate the playa. When Frenchman Flat playa is inundated, residual radionuclides on the typically dry playa surface may become submerged, allowing water-soil interactions that could provide a mechanism for transport of radionuclides away from known areas of contamination. The potential for radionuclide transport by occasional inundation of the Frenchman Flat playa was examined using geographic information systems and satellite imagery to delineate the timing and areal extent of inundation; collecting water samples during inundation and analyzing them for chemical and isotopic content; characterizing suspended/precipitated materials and archived soil samples; modeling water-soil geochemical reactions; and modeling the mobility of select radionuclides under aqueous conditions. The physical transport of radionuclides by water was not evaluated in this study. Frenchman Flat playa was inundated with precipitation during two consecutive winters in 2009-2010 and 2010-2011. Inundation allowed for collection of multiple water samples through time as the areal extent of inundation changed and ultimately receded. During these two winters, precipitation records from a weather station in Frenchman Flat (Well 5b) provided information that was used in combination with geographic information systems, Landsat imagery, and image processing techniques to identify and quantify the areal extent of inundation. After inundation, water on the playa disappeared quickly, for example, between January 25, 2011 and February 10, 2011, a period of 16 days, 92 percent of the areal extent of inundation receded (2,062,800 m2). Water sampling provided

  10. Estimating recharge through Playa Lakes to the Southern High Plains Aquifer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the Southern High Plains of Texas, it is accepted that focused recharge to the High Plains Aquifer (locally known as the Ogallala) occurs through over 20,000 playa lakes, which are local depressions that collect storm runoff. The amount and rate of recharge is not precisely known, and the impact ...

  11. Suitability of Eastern Gamagrass for in situ Precipitation Catchment Forage Production in Playas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Freshwater playas, shallow ephemeral lakes whose basins fill after periods of prolonged or intense rainfall preceding runoff events, occupy 3-5% of the land in the Llano Estacado and are considered marginal farmlands. The goals of this work were to determine if a native species, eastern gamagrass, c...

  12. A water resource assessment of the playa lakes of the Texas High Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Texas Water Development Board (TWDB) staff are studying the water-resource potential of playa lakes in the Texas High Plains in partnership with the U. S. Department of Agriculture— Agricultural Research Service and Texas Tech University. Phase 1 of the research seeks to measure the volume of water ...

  13. Monitoring infiltration and recharge of playa lakes in the Texas Southern High Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Preliminary results from playa lakes monitored by the Texas Water Development Board (TWDB) suggest that a small volume of deep infiltration and recharge to the Ogallala aquifer occurs along the margins of the lake beds, while the majority of infiltration associated with a typical inundation remains ...

  14. Biophysical Controls over Carbon and Nitrogen Stocks in Desert Playa Wetlands

    NASA Astrophysics Data System (ADS)

    McKenna, O. P.; Sala, O. E.

    2014-12-01

    Playas are ephemeral desert wetlands situated at the bottom of closed catchments. Desert playas in the Southwestern US have not been intensively studied despite their potential importance for the functioning of desert ecosystems. We want to know which geomorphic and ecological variables control of the stock size of soil organic carbon, and soil total nitrogen in playas. We hypothesize that the magnitude of carbon and nitrogen stocks depends on: (a) catchment size, (b) catchment slope, (d) catchment vegetation cover, (e) bare-ground patch size, and (f) catchment soil texture. We chose thirty playas from across the Jornada Basin (Las Cruces, NM) ranging from 0.5-60ha in area and with varying catchment characteristics. We used the available 5m digital elevation map (DEM) to calculate the catchment size and catchment slope for these thirty playas. We measured percent cover, and patch size using the point-intercept method with three 10m transects in each catchment. We used the Bouyoucos-hydrometer soil particle analysis to determine catchment soil texture. Stocks of organic carbon and nitrogen were measured from soil samples at four depths (0-10 cm, 10-30 cm, 30-60 cm, 60-100 cm) using C/N combustion analysis. In terms of nitrogen and organic carbon storage, we found soil nitrogen values in the top 10cm ranging from 41.963-214.365 gN/m2, and soil organic carbon values in the top 10cm ranging from 594.339-2375.326 gC/m2. The results of a multiple regression analysis show a positive relationship between catchment slope and both organic carbon and nitrogen stock size (nitrogen: y= 56.801 +47.053, R2=0.621; organic carbon: y= 683.200 + 499.290x, R2= 0.536). These data support our hypothesis that catchment slope is one of factors controlling carbon and nitrogen stock in desert playas. We also applied our model to the 69 other playas of the Jornada Basin and estimated stock sizes (0-10cm) between 415.07-447.97 Mg for total soil nitrogen and 4627.99-5043.51 Mg for soil organic

  15. Evaporites, surface roughness, and inundation in a playa dust source; implications of surface composition for erodibility

    NASA Astrophysics Data System (ADS)

    Tollerud, H.; Fantle, M.

    2013-12-01

    An understanding of fundamental controls on dust emission is critical in order to predict and model geochemical fluxes in the Earth system. Crucial parameters for dust emission include surface properties such as roughness, strength, and composition, which affect the erodibility of surface sediments. Accordingly, knowledge of the processes that govern surface properties is vital for predicting geochemical dust fluxes. In this study, we examine the spatial distribution of mineralogy within a playa dust source (Black Rock Desert, NV, USA) and its association with the spatial distribution of annual inundation, and employ a numerical model to assess the importance of transport by inundation for producing the distribution of mineralogy that we observe. Additionally, we experimentally investigate the effect of evaporite mineralogy on the development of surface roughness in a playa analog surface. We hypothesize that evaporite minerals in playa surface crusts reduce erodibility by contributing to sediment aggregation, promoting smoothing of the surface and a decrease in the availability of particles for saltation. Heterogeneity in surface mineralogy will then affect erodibility. Thus, it is useful to identify controls on the distribution of mineralogy (specifically evaporites) across a playa dust source. In particular, a connection between inundation and surface heterogeneity suggests that inundation could influence erodibility. Semi-quantitative X-ray diffraction analysis of surface sediments from the Black Rock Desert shows that evaporite content is variable; halite content varies from 0-40 wt%, and calcite from 2-15 wt%, with average sediment compositions of 30% quartz, 45% clay, and 10% plagioclase. Average calcite content is lower (7.6%) for sites within the inundated area of the previous year's playa lake (detected using MODIS satellite imagery; band 6, 1640 nm) than for sites outside this area (average calcite content 9.5%). Sites inundated the previous year are

  16. Using the WRF model to simulate the playa breeze over Dugway Proving Ground

    NASA Astrophysics Data System (ADS)

    Spade, Daniela Maria

    The aim of this model and observation based study is to investigate the Advanced Research Weather Research and Forecasting Model's (WRF-ARW, although WRF from hereout) ability to simulate the three-dimensional structure of playa breezes and drainage flows occurring in Dugway Proving Ground, Utah using sub-km nesting in addition to improved land use and terrain datasets (as compared to the default datasets provided with WRF), in addition to studying the diurnal cycle and interactions between the playa breeze and drainage flows. A playa breeze is a thermally forced air circulation system that develops near the edge of playas, which have properties distinct from the surrounding land cover, including a higher thermal conductivity, a higher albedo due to the presence of a thin salt crust at the surface, sparse vegetation cover relative to the surrounding land cover, and a higher latent heat flux. The combination of each of these characteristics produces a thermally direct circulation, with low-level flow away from the playa during the day and toward the playa at night, the result of a cooler playa during the day and a warmer playa at night. Five model runs were performed using the Noah land Surface model, each employing a four telescoping nest strategy. Each model run was given a different set of physical parameterizations, with some using GFS model output and others using NAM model output. The object behind utilizing five model runs was to isolate the impacts made by the differing model parameterization schemes used for each simulation. This was accomplished by comparing the model run output to in situ weather observations, provided courtesy of the Mountain Terrain Atmospheric Modeling and Observation Program (MATERHORN), an ongoing Multidisciplinary University Research Initiative (MURI) sponsored by the Office of Naval Research with the University of Notre Dame acting as Project Lead. It was found that each of the five model simulations tended to produce a longer

  17. Ratosa playa lake in southern Spain. Karst pan or compound sink?

    PubMed

    Rodríguez-Rodríguez, Miguel; Martos-Rosillo, Sergio; Pedrera, Antonio; Benavente-Herrera, José

    2015-04-01

    In Andalusia (Spain), there are more than 45 semiarid playa lakes protected as natural reserves and related to karstic outcrops. Some of them are located over regional karstic aquifers and have internal drainage networks with sporadic surface outlets, such as sinkholes (compound sinks), but the majority of such playas have no internal drainage systems, so the only water output is evaporation (karst pans). Karst pans are perched and disconnected from the groundwater system. The fact that the Ratosa playa lake is partially located over a karstic Sierra, as well as other hydromorphological observations, it is suggested that the system could be of a compound type, but a detailed hydrogeological analysis showed that the playa is disconnected from the aquifer, so it is in fact a karst pan. Once the hydrological functioning had been established, a monthly water balance for a 10-year period (1998-2008), enabled us to reproduce the evolution of the water level of the playa lake. Estimations of runoff were carried out by a soil water estimate for a water holding capacity in the soil of 191 mm. Results show a good correlation (>90%) after calibration with the time series of water level in the lake for the same period confirming geological observations. Our results highlight that this water body is extremely vulnerable to hydrological alterations of its watershed caused by human activities, particularly those related to land-use change for agriculture. For this reason, we propose a new protection zone, based on hydrological knowledge, instead of the present Peripheral Area of Protection. PMID:25810083

  18. Surface water hydrology and geomorphic characterization of a playa lake system: Implications for monitoring the effects of climate change

    NASA Astrophysics Data System (ADS)

    Adams, Kenneth D.; Sada, Donald W.

    2014-03-01

    Playa lakes are sensitive recorders of subtle climatic perturbations because these ephemeral water bodies respond to the flux of diffuse and channelized flow from their watersheds as well as from direct precipitation. The Black Rock Playa in northwestern Nevada is one of the largest playas in North America and is noted for its extreme flatness, varying less than one meter across a surface area of 310 km2. Geo-referenced Landsat imagery was used to map surface-area fluctuations of ephemeral lakes on the playa from 1972 to 2013 to provide baseline data on surface water hydrology of this system to compare to future hydrologic conditions caused by climate change. The area measurements were transformed into depth and volumetric estimates using results of detailed topographic global positioning system (GPS) surveys and correlated with available surface hydrological and meteorological monitoring data. Playa lakes reach their maximum size (<350 km2) in spring, fed by melting snows from high mountains on the periphery of the drainage basin, and usually desiccate by early- to mid-summer. The combination of a shallow groundwater table, sediment deposition, and hydro-aeolian planation probably are largely responsible for the flatness of the playa. When lakes do not form for a period of several years, the clay- and silt-rich playa surface transforms from one that is hard and durable into one that is soft and puffy, probably from upward capillary movement of water and resultant evaporation. Subsequent flooding restores the hard and durable surface. The near-global availability of Landsat imagery for the last 41 years should allow the documentation of baseline surface hydrologic characteristics for a large number of widely-distributed playa lake systems that can be used to assess the hydrologic effects of future climate changes.

  19. Sliding stones of Racetrack Playa, Death Valley, USA: The roles of rock thermal conductivity and fluctuating water levels

    NASA Astrophysics Data System (ADS)

    Kletetschka, Gunther; Hooke, Roger LeB.; Ryan, Andrew; Fercana, George; McKinney, Emerald; Schwebler, Kristopher P.

    2013-08-01

    On occasion, Racetrack playa in Death Valley National Park becomes flooded and temperatures then drop appreciably below freezing. The thermal conductivity of rock is greater than that of water, so heat is conducted from a partially-submerged rock faster than from water. Consequently, a collar of thicker ice forms at the water surface, a layer of ice forms on more deeply-submerged parts of the rock, and playa sediment beneath the rock may even become frozen to it. While this occurs, only a surface layer of ice forms on water away from the rock. Once the ice becomes thick enough, perhaps only 5-10 mm, either the buoyancy of the ice or additions of water to the playa by rain, snow-melt, or groundwater seepage then reduce the normal force between the rock and the playa to the point where wind shear can move the ice sheet with its entrained rocks, making trails (Stanley, 1955; Reid et al., 1995). After the ice melts, rocks are left at the ends of the trails, sometimes atop a pedestal of silt. A renewed increase in water level on the playa before the ice melts may lift a rock completely free of the playa surface and whisk it away, leaving a rockless trail. During a movement event, changes in rock orientation or water depth may result in changes in width along the track. Rock speeds are likely tens to hundreds of millimeters per second.

  20. Sliding rocks on Racetrack Playa, Death Valley National Park: first observation of rocks in motion.

    PubMed

    Norris, Richard D; Norris, James M; Lorenz, Ralph D; Ray, Jib; Jackson, Brian

    2014-01-01

    The engraved trails of rocks on the nearly flat, dry mud surface of Racetrack Playa, Death Valley National Park, have excited speculation about the movement mechanism since the 1940s. Rock movement has been variously attributed to high winds, liquid water, ice, or ice flotation, but has not been previously observed in action. We recorded the first direct scientific observation of rock movements using GPS-instrumented rocks and photography, in conjunction with a weather station and time-lapse cameras. The largest observed rock movement involved > 60 rocks on December 20, 2013 and some instrumented rocks moved up to 224 m between December 2013 and January 2014 in multiple move events. In contrast with previous hypotheses of powerful winds or thick ice floating rocks off the playa surface, the process of rock movement that we have observed occurs when the thin, 3 to 6 mm, "windowpane" ice sheet covering the playa pool begins to melt in late morning sun and breaks up under light winds of -4-5 m/s. Floating ice panels 10 s of meters in size push multiple rocks at low speeds of 2-5 m/min. along trajectories determined by the direction and velocity of the wind as well as that of the water flowing under the ice. PMID:25162535

  1. Filed-Analog Study: Efficiency of microbial fossilization in sulfate-rich playas

    NASA Astrophysics Data System (ADS)

    Glamoclija, M.; Zeidan, M.; Potochniak, S.

    2015-12-01

    The samples with the highest priority for sample return will be samples that contain potential life signatures. Sulfate-rich salts have been identified as important component of Mars sedimentary deposits, illustrating the importance of near-surface hydrological processes during the planet's history. The presence of Noachian/early Hesperian sulfate-rich deposits have been identified by the MER's Opportunity at Meridiani Planum and by MRO mission in sedimentary sequences within Gale crater, the Mars Science Laboratory landing site. White Sands National Monument, which we are using as a terrestrial analog in our study, holds active playas that may contain different sizes of water bodies during the year. Alkali Flat contains also preserved deposits of Pleistocene Lake Otero. The presence of a range of modern playas and equivalent Pleistocene deposits allows for an excellent comparison of these different extreme transitional habitats and potential of preservation of organics in an evaporitic playa setting. We have performed shallow drilling (1m) of the Lake Lucero deposits and of Lake Otero evaporitic sequence. The XRD analysis revealed that samples are mainly composed of gypsum and minor mineral phases as brushite, halite and quartz. SEM/EDS revealed the presence of amorphous phases such as halite, glauberite, magnesium chlorite salt, and diatom shells and biofilm. Biofilm is found in near surface samples, which may be attributed to microbial adaptation to desert environment and considered as one of the characteristics of modern and not fossil microbial communities. The compositional difference of salt precipitates associated with potentially geologically old biofilm and the modern counterpart are still ongoing and our findings will be presented at the conference. Further, comparison of environmental physicochemical conditions and molecular biology will be used to determine the characteristics of modern microbial habitats/deposits and to attempt to distinguish them

  2. Investigating playa surface textures: The impact of chemistry and environment on surface morphology and dust

    NASA Astrophysics Data System (ADS)

    Tollerud, H. J.; Fantle, M. S.

    2010-12-01

    Mineral dust is an important component of geochemical cycles, but its impact on those cycles is not thoroughly understood. For instance, dust inputs to the ocean have been suggested to affect the iron cycle by stimulating natural iron fertilization, which then could modify climate. The influence of dust on geochemical cycles is determined by the chemical and mineralogical composition of dust inputs, which is governed in turn by the composition of dust source regions. A loose, unconsolidated surface texture is more easily ablated by wind, and so a location where composition and environmental characteristics encourage this type of surface is more likely to produce dust and influence geochemical cycles. Also, if evaporation concentrates evaporites such as calcite at the surface of a dust producing region, dust Ca concentrations are likely to be higher. Playas can be regionally significant dust source regions, and they are amenable to study as their surface textures often vary significantly across small areas. This study investigates surface processes experimentally, and compares the results to observations of surface texture in a natural playa system (the Black Rock Desert, Nevada). We dry surfaces with 25% to 75% clay and quartz at 40°C for approximately a day, wet the surface to simulate rain, and then repeat the cycle multiple times. We estimate surface roughness, measure surface strength with a penetrometer, and investigate thermal characteristics with an IR camera (wavelength range 8-12μm). We find that textures similar to those in playas can be reproduced with cycles of wetting and drying, such as might occur in an arid environment with intermittent rain. We investigate the addition of calcite and halite, since their precipitation potentially can disrupt the clay surfaces through the formation and expansion of crystals, thereby linking the chemical composition with the disruption of a strong surface texture and an increased chance of dust production. In the

  3. Effects of landuse and precipitation on pesticides and water quality in playa lakes of the southern high plains.

    PubMed

    Anderson, Todd A; Salice, Christopher J; Erickson, Richard A; McMurry, Scott T; Cox, Stephen B; Smith, Loren M

    2013-06-01

    The 25000 playa wetlands within the Southern High Plains (SHP) of the United States of America (USA) are the dominant hydrogeomorphic feature in the region, providing habitat for numerous plants and wildlife. The SHP are among the most intensively cultivated regions; there are concerns over the degradation and/or loss of playa wetland habitat. We examined water quality in playa wetlands surrounded by both grassland and agriculture and measured water concentrations of pesticides used on cotton (acephate, trifluralin, malathion, pendimethalin, tribufos, bifenthrin, λ-cyhalothrin, acetamiprid, and thiamethoxam), the dominant crop in the SHP. Pesticides used on cotton were detected in water samples collected from all playas. Precipitation events and the amount of cultivation were related to pesticide concentrations in sediment and water. Our results show that pesticide concentrations were related in some circumstances to time, precipitation, and tilled-index for some but not all pesticides. We further compared measured pesticide concentrations in playas to toxicity benchmarks used by the US EPA in pesticide ecological risk assessments to obtain some insight into the potential for ecological effects. For all pesticides in water, the maximum measured concentrations exceeded at least one toxicity benchmark, while median concentrations did not exceed any benchmarks. This analysis indicates that there is a potential for adverse effects of pesticides to aquatic organisms. PMID:23541358

  4. Dust emissions from undisturbed and disturbed, crusted playa surfaces: Cattle trampling effects

    NASA Astrophysics Data System (ADS)

    Baddock, Matthew C.; Zobeck, Ted M.; Van Pelt, R. Scott; Fredrickson, Ed L.

    2011-06-01

    Dry playa lake beds can be significant sources of fine dust emission. This study used a portable field wind tunnel to quantify the PM 10 emissions from a bare, fine-textured playa surface located in the far northern Chihuahua Desert. The natural, undisturbed crust and its subjection to two levels of animal disturbance (one and ten cow passes) were tested. The wind tunnel generated dust emissions under controlled conditions for firstly an initial blow-off of the surface, followed by two longer runs with sand added to the flow as an abrader material. Dust was measured using a GRIMM particle monitor. For the study playa, no significant differences in PM 10 concentration and emission flux were found between the untrampled surface and following a single animal pass. This was the case for both the initial blow-offs and tests on plots under a steady abrader rate. Significantly higher dust loading was only associated with the effect of 10 animal passes. In the blow-offs, the higher PM 10 yield after 10 passes reflected the greater availability of easily entrainable fine particles. Under abrasion, the effect of the heaviest trampling increased the emission flux by a third and abrasion efficiency by around 50% more than values on the untrampled surface. This enhanced abrasion efficiency persisted for a 30 min period under abrasion before the positive effect of the disturbance was no longer evident. The findings highlight the role of a threshold of disturbance that determines if supply-limited surfaces will exhibit enhanced wind erosion or not after undergoing perturbation.

  5. The impact of climate and composition on playa surface roughness: Investigation of atmospheric mineral dust emission mechanisms

    NASA Astrophysics Data System (ADS)

    Tollerud, H. J.; Fantle, M. S.

    2011-12-01

    Atmospheric mineral dust has a wide range of impacts, including the transport of elements in geochemical cycles, health hazards from small particles, and climate forcing via the reflection of sunlight from dust particles. In particular, the mineral dust component of climate forcing is one of the most uncertain elements in the IPCC climate forcing summary. Mineral dust is also an important component of geochemical cycles. For instance, dust inputs to the ocean potentially affect the iron cycle by stimulating natural iron fertilization, which could then modify climate via the biological pump. Also dust can transport nutrients over long distances and fertilize nutrient-poor regions, such as island ecosystems or the Amazon rain forest. However, there are still many uncertainties in quantifying dust emissions from source regions. One factor that influences dust emission is surface roughness and texture, since a weak, unconsolidated surface texture is more easily ablated by wind than a strong, hard crust. We are investigating the impact of processes such as precipitation, groundwater evaporation, and wind on surface roughness in a playa dust source region. We find that water has a significant influence on surface roughness. We utilize ESA's Advanced Synthetic Aperture Radar (ASAR) instrument to measure roughness in the playa. A map of roughness indicates where the playa surface is smooth (on the scale of centimeters) and potentially very strong, and where it is rough and might be more sensitive to disturbance. We have analyzed approximately 40 ASAR observations of the Black Rock Desert from 2007-2011. In general, the playa is smoother and more variable over time relative to nearby areas. There is also considerable variation within the playa. While the playa roughness maps changed significantly between summers and between observations during the winters, over the course of each summer, the playa surface maintained essentially the same roughness pattern. This suggests that

  6. Briny lakes on early Mars? Terrestrial intracrater playas and Martian candidates

    NASA Technical Reports Server (NTRS)

    Lee, P.

    1993-01-01

    Recently, salt-rich aqueous solutions have been invoked in the preterrestrial alteration of the Nakhla and Lafayette SNC meteorites. The findings substantiate the long-standing suspicion that salts are abundant on Mars and, more importantly, that brines have played a significant role in Martian hydrogeological history. Adding to the growing body of evidence, I report here on the identification of several unusual intracrater high-albedo features in the ancient cratered highlands of Mars, which I interpret as possible saline playas, or salt pans.

  7. Aeolian responses to climate variability during the past century on Mesquite Lake Playa, Mojave Desert

    NASA Astrophysics Data System (ADS)

    Whitney, J. W.; Breit, G. N.; Buckingham, S. E.; Reynolds, R. L.; Bogle, R. C.; Luo, L.; Goldstein, H. L.; Vogel, J. M.

    2015-02-01

    The erosion and deposition of sediments by wind from 1901 to 2013 have created large changes in surface features of Mesquite Lake playa in the Mojave Desert. The decadal scale recurrence of sand-sheet development, migration, and merging with older dunes appears related to decadal climatic changes of drought and wetness as recorded in the precipitation history of the Mojave Desert, complemented by modeled soil-moisture index values. Historical aerial photographs, repeat land photographs, and satellite images document the presence and northward migration of a mid-20th century sand sheet that formed during a severe regional drought that coincided with a multi-decadal cool phase of the Pacific Decadal Oscillation (PDO). The sand sheet slowly eroded during the wetter conditions of the subsequent PDO warm phase (1977-1998) due to a lack of added sediment. Sand cohesion gradually increased in the sand sheet by seasonal additions of salt and clay and by re-precipitation of gypsum, which resulted in the wind-carving of yardangs in the receding sand sheet. Smaller yardangs were aerodynamically shaped from coppice dunes with salt-clay crusts, and larger yardangs were carved along the walls and floor of trough blowouts. Evidence of a 19th century cycle of sand-sheet formation and erosion is indicated by remnants of yardangs, photographed in 1901 and 1916, that were found buried in the mid-20th century sand sheet. Three years of erosion measurements on the playa, yardangs, and sand sheets document relatively rapid wind erosion. The playa has lowered 20 to 40 cm since the mid-20th century and a shallow deflation basin has developed since 1999. Annually, 5-10 cm of surface sediment was removed from yardang flanks by a combination of wind abrasion, deflation, and mass movement. The most effective erosional processes are wind stripping of thin crusts that form on the yardang surfaces after rain events and the slumping of sediment blocks from yardang flanks. These wind

  8. Dust Emissions from Undisturbed and Disturbed, Crusted Playa Surfaces: Cattle Trampling Effect

    NASA Astrophysics Data System (ADS)

    Zobeck, T. M.; Baddock, M. C.; van Pelt, R.; Fredrickson, E. L.

    2009-12-01

    Dry playa lake beds can be a significant source of fine dust emissions during high wind events in arid and semiarid landscapes. The physical and chemical properties of the playa surface control the amount and properties of the dust emitted. In this study, we use a field wind tunnel to quantify the dust emissions from a bare, fine-textured playa surface located in the Chihuahua Desert at the Jornada Experimental Range, near Las Cruces, New Mexico, USA. We tested natural, undisturbed crusted surfaces and surfaces that had been subjected to two levels of domestic animal disturbance. The animal disturbance was provided by trampling produced from one and ten passes along the length of the wind tunnel by a 630 kg Angus-Hereford cross cow. The trampling broke the durable crust and created loose erodible material. Each treatment (natural crust, one pass, and ten passes) was replicated three times. A push-type wind tunnel with a 6 m long, 0.5 m wide, and 1 m high test section was used to generate dust emissions under controlled conditions. Clean medium sand was dropped onto the playa surface to act as an abrader material. The tunnel wind speed was equivalent to 15 m/s at a height of 2 m over a smooth soil surface. The tunnel was initially run for ten minutes, with no abrader added. A second 30 minute run was subsequently sampled as abrader was added to the wind stream. Dust and saltating material were collected using an isokinetic slot sampler at the end of the tunnel. Total airborne dust was collected on two 25 cm x 20 cm glass fiber filters (GFF) and measured using a GRIMM particle monitor every 6 sec throughout each test run. Disturbance by trampling generated increased saltating material and airborne dust. The amount of saltating material measured during the initial (no abrader added) run was approximately 70% greater and 5.8 times the amount of saltating material measured on the one pass and ten pass plots, respectively, compared with that observed on the undisturbed

  9. The application of remote sensing technology to the inventory of playa lakes in the High Plains of Texas

    NASA Technical Reports Server (NTRS)

    Wyatt, A. W.; Ellis, M. L.; Bell, A. E.

    1975-01-01

    The feasibility of using LANDSAT digital data to inventory the playa lakes of the High Plains region of Texas was investigated. The project will use the detection and mapping (DAM) package developed at NASA-Johnson Space Center. The economy of the High Plains region is dependent on ground water for irrigation and the Ogallala aquifer is being depleted faster than it is being recharged. The playa lakes represent a potential source of artificial recharge for the aquifer and an inventory is the first step in that direction.

  10. Trail formation by ice-shoved "sailing stones" observed at Racetrack Playa, Death Valley National Park

    NASA Astrophysics Data System (ADS)

    Lorenz, R. D.; Norris, J. M.; Jackson, B. K.; Norris, R. D.; Chadbourne, J. W.; Ray, J.

    2014-08-01

    Trails in the usually-hard mud of Racetrack Playa in Death Valley National Park attest to the seemingly-improbable movement of massive rocks on an exceptionally flat surface. The movement of these rocks, previously described as "sliding stones", "playa scrapers", "sailing stones" etc., has been the subject of speculation for almost a century but is an exceptionally rare phenomenon and until now has not been directly observed. Here we report documentation of multiple rock movement and trail formation events in the winter of 2013-2014 by in situ observation, video, timelapse cameras, a dedicated meteorological station and GPS tracking of instrumented rocks. Movement involved dozens of rocks, forming fresh trails typically of 10s of meters length at speeds of ~5 cm s-1 and were caused by wind stress on a transient thin layer of floating ice. Fracture and local thinning of the ice decouples some rocks from the ice movement, such that only a subset of rocks move in a given event.

  11. Numerical investigation of coupled density-driven flow and hydrogeochemical processes below playas

    NASA Astrophysics Data System (ADS)

    Hamann, Enrico; Post, Vincent; Kohfahl, Claus; Prommer, Henning; Simmons, Craig T.

    2015-11-01

    Numerical modeling approaches with varying complexity were explored to investigate coupled groundwater flow and geochemical processes in saline basins. Long-term model simulations of a playa system gain insights into the complex feedback mechanisms between density-driven flow and the spatiotemporal patterns of precipitating evaporites and evolving brines. Using a reactive multicomponent transport model approach, the simulations reproduced, for the first time in a numerical study, the evaporite precipitation sequences frequently observed in saline basins ("bull's eyes"). Playa-specific flow, evapoconcentration, and chemical divides were found to be the primary controls for the location of evaporites formed, and the resulting brine chemistry. Comparative simulations with the computationally far less demanding surrogate single-species transport models showed that these were still able to replicate the major flow patterns obtained by the more complex reactive transport simulations. However, the simulated degree of salinization was clearly lower than in reactive multicomponent transport simulations. For example, in the late stages of the simulations, when the brine becomes halite-saturated, the nonreactive simulation overestimated the solute mass by almost 20%. The simulations highlight the importance of the consideration of reactive transport processes for understanding and quantifying geochemical patterns, concentrations of individual dissolved solutes, and evaporite evolution.

  12. Strontium isotope geochemistry of soil and playa deposits near Yucca Mountain, Nevada

    SciTech Connect

    Marshall, B.D.; Mahan, S.A.

    1994-12-31

    The isotopic composition of strontium contained in the carbonate fractions of soils provides an excellent tracer which can be used to test models for their origin. This paper reports data on surface coatings and cements, eolian sediments, playas and alluvial fan soils which help to constrain a model for formation of the extensive calcretes and fault infilling in the Yucca Mountain region. The playas contain carbonate with a wide range of strontium compositions; further work will be required to fully understand their possible contributions to the pedogenic carbonate system. Soils from an alluvial fan to the west of Yucca Mountain show that only small amounts of strontium are derived from weathering of silicate detritus. However, calcretes from a fan draining a carbonate terrane have strontium compositions dominated locally by the limestone strontium component. Although much evidence points to an eolian source for at least some of the strontium in the pedogenic carbonates near Yucca Mountain, an additional component or past variation of strontium composition in the eolian source is required to model the pedogenic carbonate system.

  13. Playa Soil Moisture and Evaporation Dynamics During the MATERHORN Field Program

    NASA Astrophysics Data System (ADS)

    Hang, Chaoxun; Nadeau, Daniel F.; Jensen, Derek D.; Hoch, Sebastian W.; Pardyjak, Eric R.

    2016-06-01

    We present an analysis of field data collected over a desert playa in western Utah, USA in May 2013, the most synoptically active month of the year, as part of the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) program. The results show that decreasing surface albedo, decreasing Bowen ratio and increasing net radiation with increasing soil moisture sustained a powerful positive feedback mechanism promoting large evaporation rates immediately following rain events. Additionally, it was found that, while nocturnal evaporation was negligible during dry periods, it was quite significant (up to 30 % of the daily cumulative flux) during nights following rain events. Our results further show that the highest spatial variability in surface soil moisture is found under dry conditions. Finally, we report strong spatial heterogeneities in evaporation rates following a rain event. The cumulative evaporation for the different sampling sites over a five-day period varied from ≈ 0.1 to ≈ 6.6 mm. Overall, this study allows us to better understand the mechanisms underlying soil moisture dynamics of desert playas as well as evaporation following occasional rain events.

  14. Multi-temporal water extent analysis of a hypersaline playa lake using Landsat Imagery

    NASA Astrophysics Data System (ADS)

    Kilic, Ecenur; Kamil Yilmaz, Koray; Lutfi Suzen, Mehmet

    2016-04-01

    Distinguishing inland water bodies from satellite imagery has always been one of the main practices of remote sensing. In some cases this differentiation can directly be obtained by visual interpretation. However, in case of hyper-saline playa lakes, presence of high albedo salt crust in the lake bed hampers visual interpretation and requires further attention. Lake Tuz is a hypersaline playa lake which is ranked as the second largest lake in Turkey. Spatio-temporal changes in lake water extent are important both economically and hydrologically including salt production, lake water balance, drought and over-exploitation issues. This study investigates the spatiotemporal changes in Lake Tuz water extent during the last decade using single-band thresholding and multi-band indices extracted from the multi-temporal Landsat 5 TM and Landsat 7 ETM+ images. The applicability of different satellite-derived indices including Normalized Difference Water Index (NDWI), Modified NDWI (MNDWI), Automated Water Extraction Index (AWEI) and Tasseled Cap Wetness (TCw) were investigated for the extraction of lake water extent from Landsat imagery. Our analysis indicated that, overall, NDWI is superior to other tested indices in separating wet/dry pixels over the lake bottom covered with salt crust. Using a NDWI thresholding procedure, the annual and seasonal variation in the Lake Tuz water extent were determined and further linked to hydro-meteorological variables such as precipitation.

  15. Hydrology and surface morphology of the Bonneville Salt Flats and Pilot Valley Playa, Utah

    USGS Publications Warehouse

    Lines, Gregory C.

    1979-01-01

    The Bonneville Salt Flats and Pilot Valley are in the western part of the Great Salt Lake Desert in northwest Utah. The areas are separate, though similar, hydrologic basins, and both contain a salt crust. The Bonneville salt crust covered about 40 square miles in the fall of 1976, and the salt crust in Pilot Valley covered 7 square miles. Both areas lack any noticeable surface relief (in 1976, 1.3 feet on the Bonneville salt crust and 0.3 foot on the Pilot Valley salt crust). The salt crust on the Salt Flats has been used for many years for automobile racing, and brines from shallow lacustrine deposits have been used for the production of potash. In recent years, there has been an apparent conflict between these two major uses of the area as the salt crust has diminished in both thickness and extent. Much of the Bonneville Racetrack has become rougher, and there has also been an increase in the amount of sediment on the south end of the racetrack. The Pilot Valley salt crust and surrounding playa have been largely unused. Evaporite minerals on the Salt Flats and the Pilot Valley playa are concentrated in three zones: (1) a carbonate zone composed mainly of authigenic clay-size carbonate minerals, (2) a sulfate zone composed mainly of authigenic gypsum, and (3) a chloride zone composed of crystalline halite (the salt crust). Five major types of salt crust were recognized on the Salt Flats, but only one type was observed in Pilot Valley. Geomorphic differences in the salt crust are caused by differences in their hydrologic environments. The salt crusts are dynamic features that are subject to change because of climatic factors and man's activities. Ground water occurs in three distinct aquifers in much of the western Great Salt Lake Desert: (1) the basin-fill aquifer, which yields water from conglomerate in the lower part of the basin fill, (2) the alluvial-fan aquifer, which yields water from sand and gravel along the western margins of both playas, and (3) the

  16. Sodium toxicity and pathology associated with exposure of waterfowl to hypersaline playa lakes of southeast New Mexico

    USGS Publications Warehouse

    Meteyer, C.U.; Dubielzig, R.D.; Dein, F.J.; Baeten, L.A.; Moore, M.K.; Jehl, J.R., Jr.; Wesenberg, K.E.

    1997-01-01

    Cause of mortality was studied in waterfowl in hypersaline playa lakes of southeast New Mexico during spring and fall migration. Mortality was not common in wild ducks resting on the playas during good weather. However, when birds remained on the lakes for prolonged periods of time, such as during experimental trials and stormy weather, a heavy layer of salt precipitated on their feathers. Sodium toxicity was the cause of death for all experimental mallards housed on playa water and for 50% of the wild waterfowl found moribund or dead during the spring of 1995. Gross lesions included heavy salt precipitation on the feathers, ocular lens opacities, deeply congested brains, and dilated, thin-walled, fluid-filled cloacae. Microscopic lesions in the more severely affected birds included liquefaction of ocular lens cortex with lens fiber swelling and multifocal to diffuse ulcerative conjunctivitis with severe granulocytic inflammation, edema, and granulocytic vasculitis resulting in thrombosis. Inflammation similar to that seen in the conjunctiva occasionally involved the mucosa of the mouth, pharynx, nasal turbinates, cloaca, and bursa. Transcorneal movement of water in response to the hypersaline conditions on the playa lakes or direct contact with salt crystals could induce anterior segment dehydration of the aqueous humor and increased osmotic pressure on the lens, leading to cataract formation.

  17. Effects of land-use change and fungicide application on soil respiration in playa wetlands and adjacent uplands of the U.S. High Plains.

    PubMed

    Daniel, Dale W; Smith, Loren M; Belden, Jason B; McMurry, Scott T; Swain, Shella

    2015-05-01

    With the increased use of fungicides in cultivated regions such as the southern High Plains (SHP), U.S., unintentional runoff and drift as well as direct overspray during aerial application lead to environmental exposures that may influence soil microbial communities and related biogeochemical functioning. Our goal was to examine the effects of two popular fungicides Headline (pyraclostrobin) and Quilt (azoxystrobin/propiconazole) on respiration from soil microbial communities in playa wetlands embedded in cropland and native grassland and their adjacent watersheds. We monitored fungicide effects (at levels of 0, .1×, 1× and 10× the label rate) by measuring respiration from plant matter amended soils collected from 6 cropland and 6 grassland playas and uplands. In addition, differences in microbial community structure among land use types were determined by measuring ergosterol levels in cropland and native grassland playas and uplands. Native grassland playas and their associated watersheds had up to 43% higher soil respiration rates than cropland playas and watersheds, indicating higher soil microbial activity. Application of either fungicide had no effect on soil respiration at any concentration in either land use type or habitat type (playa/watershed). Native grassland playas and watersheds had 3 and 1.6 times higher ergosterol content than cropland playas and watersheds. The lack of soil respiration response to fungicide application does not necessarily suggest that fungicides used in this study do not affect non-target soil microbial communities due to potential compensation by other biota. Future studies should further elucidate existing microorganism communities in playas and their watersheds. PMID:25668281

  18. A hydrous Ca-bearing magnesium carbonate from playa lake sediments, Salines Lake, Spain

    USGS Publications Warehouse

    Queralt, I.; Julia, R.; Plana, F.; Bischoff, J.L.

    1997-01-01

    Sediments of playa Lake Salines, SE, Spain, contain a carbonate mineral characterized by X-ray diffraction peaks very similar to, but systematically shifted from those of pure magnesite. Analyses (SEM, IR and Raman spectroscopy, DTA, TGA, and ICP) indicate the mineral is a hydrous Ca-bearing magnesium carbonate with the chemical formula (Mg0.92,Ca0.08)CO3??3H2O. Thermal characteristics of the mineral are similar to those of other known hydrated magnesium carbonates. X-ray and electron diffraction data suggests a monoclinic system (P21/n space group) with unit-cell parameters of a = 6.063(6), b = 10.668(5), and c = 6.014(4) A?? and ?? = 107.28??.

  19. Mapping playa evaporite minerals and associated sediments in Death Valley, California, with multispectral thermal infrared images

    USGS Publications Warehouse

    Crowley, J.K.; Hook, S.J.

    1996-01-01

    Efflorescent salt crusts and associated sediments in Death Valley, California, were studied with remote-sensing data acquired by the NASA thermal infrared multispectral scanner (TIMS). Nine spectral classes that represent a variety of surface materials were distinguished, including several classes that reflect important aspects of the playa groundwater chemistry and hydrology. Evaporite crusts containing abundant thenardite (sodium sulfate) were mapped along the northern and eastern margins of the Cottonball Basin, areas where the inflow waters are rich in sodium. Gypsum (calcium sulfate) crusts were more common in the Badwater Basin, particularly near springs associated with calcic groundwaters along the western basin margin. Evaporite-rich crusts generally marked areas where groundwater is periodically near the surface and thus able to replenish the crusts though capillary evaporation. Detrital silicate minerals were prevalent in other parts of the salt pan where shallow groundwater does not affect the surface composition. The surface features in Death Valley change in response to climatic variations on several different timescales. For example, salt crusts on low-lying mudflats form and redissolve during seasonal-to-interannual cycles of wetting and desiccation. In contrast, recent flooding and erosion of rough-salt surfaces in Death Valley probably reflect increased regional precipitation spanning several decades. Remote-sensing observations of playas can provide a means for monitoring changes in evaporite facies and for better understanding the associated climatic processes. At present, such studies are limited by the availability of suitable airborne scanner data. However, with the launch of the Earth Observing System (EOS) AM-1 Platform in 1998, multispectral visible/near-infrared and thermal infrared remote-sensing data will become globally available. Copyright 1996 by the American Geophysical Union.

  20. Temporal Dynamics of Sodic Playa Salt Crust Patterns: Implications for Aeolian Dust Emission Potential

    NASA Astrophysics Data System (ADS)

    Nield, J. M.; King, J.; Bryant, R. G.; Wiggs, G.; Eckardt, F. D.; Thomas, D. S.; Washington, R.

    2013-12-01

    Salt pans (or playas) are common in arid environments and can be major sources of windblown mineral dust, but there are uncertainties associated with their dust emission potential. These landforms typically form crusts which modify both their erosivity and erodibility by limiting sediment availability, modifying surface and aerodynamic roughness and limiting evaporation rates and sediment production. Here we show the relationship between seasonal surface moisture change and crust pattern development based on both remote-sensing and field surface and atmospheric measurements. We use high resolution (sub-cm) terrestrial laser scanning (TLS; ground-based lidar) surveys over weekly, monthly and annual timescales to accurately characterise crustal ridge thrusting and collapse. This can be as much as 2 mm/day on fresh pan areas that have recently been reset by flooding. Over a two month period, this ridge growth can change aerodynamic roughness length values by 6.5 mm. At the same time, crack densities across the surface increase and this raises the availability of erodible fluffy, low density dust source sediment stored below the crust layer. Ridge spaces are defined in the early stages of crust development, as identified by Fourier Transform analysis, but wider wavelengths become more pronounced over time. We present a conceptual model accounting for the driving forces (subsurface, surface and atmospheric moisture) and feedbacks between these and surface shape that lead to crust pattern trajectories between highly emissive degraded surfaces and less emissive ridged or continuous crusts. These findings improve our understanding of temporal changes in dust availability and supply from playa source regions.

  1. Dust emission thresholds from sodic playas with varying geochemistry and environmental conditions

    NASA Astrophysics Data System (ADS)

    Nield, J. M.; McKenna Neuman, C.; O'Brien, P.

    2014-12-01

    Sodic playa surfaces can be major sources of dust emission but their erodibility depends on the surface salt crust characteristics. Here we determine dust emission thresholds in a wind tunnel for 22 different crusts with varying concentrations of sodium sulphate and sodium chloride. Crusts mimic those on Sua Pan, in the Makgadikgadi Basin, Botswana, which is one of the biggest dust hot spots in the Southern Hemisphere. Crusts were grown by encouraging capillary processes and subjected to several weeks of diurnal temperature variation to enable the development of hydrated and dehydrated salt crystals, along with low density, 'fluffy' sediment beneath the primary (and in some cases, secondary) crust. Spray on crusts and liquefied crusts were also developed for response comparison. Using laser scanning we tracked surface change and crystal growth, which we link to crust type and evaporation rates. We found that under pre-dawn and early morning Sua Pan conditions, crusts were typically non-emissive, but during mid-day temperature and humidity conditions typical of Sua Pan in August and September (dry and peak dust emission season), several crusts became friable and highly emissive above wind velocities of 7 m/s, which agrees with in-situ field observations. Thenardite capillary crusts were the most emissive, in contrast to supply limited, halite liquefied crusts which were relatively stable. Disturbances, or small crust fractures, common on polygonal surface patterns decreased the dust emission threshold values and enabled emission from more stable crusts. Our study confirms the potential of playa surfaces to emit dust without the presence of saltation, and highlights the sensitivity of emission thresholds to crust geochemistry, evaporation rates and temperature and humidity conditions.

  2. Mineralogical Composition and Potential Dust Source of Playas in the Western U.S. and Australia as Remotely Identified Through Imaging Spectroscopy.

    NASA Astrophysics Data System (ADS)

    Raming, L. W.; Farrand, W. H.; Bowen, B.

    2015-12-01

    Playas are significant dust sources and as a result are potentially hazardous to human health. The composition of the dust is a function of the mineralogical content of the playa and associated brines. Playas are found in arid climates globally, however they are challenging to map geologically as they are often hard to access, have subtle variations in mineralogy, and are topographically featureless. This study uses remote sensing in the form of imaging spectroscopy to map the mineralogical composition of five playas from different geologic settings: Railroad Valley Playa, Nevada, USA; Bonneville Salt Flats, Utah, USA; White Sands National Monument, New Mexico, USA; Lake Brown, Western Australia, Australia; and Lake Tyrrell, Victoria, Australia.Multiple spectrometers were used for this study; these include the multispectral sensor ASTER, and the hyperspectral sensors AVIRIS, HICO, and HyMap. All scenes were processed in ENVI and corrected to at surface reflectance using FLAASH, QUAC or Empirical Line methods. Minerals were identified through a standard end-member extraction approach and mapped using multi-range spectral feature fitting and other methods. Additionally, remote data are combined with in-situ field-based spectra and sample-based laboratory spectra.Initial results suggest various and differing mineralogy between playas. The most abundant mineralogy includes clay minerals such as illite and montmorillonite and evaporites such as gypsum. Additionally there has been identification of Fe absorption bands in the visible / near infrared at White Sands National Monument, and Lake Brown and Lake Tyrell, suggesting the presence of iron bearing minerals. Further research will provide a more comprehensive list of minerals identified by absorption features as related to specific sensors. Collectively, these analyses will be used characterize overall patterns in playa surface mineralogy and to evaluate the parameters that influence playa dust source composition.

  3. Deflation and Meteorite Exposure on Playa Lakes in the Southwestern United States: Unpaired Meteorites at Lucerne Dry Lake, California

    NASA Astrophysics Data System (ADS)

    Verish, Robert S.; Rubin, Alan E.; Moore, Carleton B.; Oriti, Ronald A.

    2000-01-01

    Numerous dry lakes (playas) dot the Mojave Desert in Southern California and adjacent desert regions in Nevada and Arizona. Most have been significantly affected by deflation processes aided by the lack of protective vegetation and occurrence of fine-grained sediments. Meteorites have been found on several playas including Lucerne Dry Lake,Rogers (formerly Muroc) Dry Lake, Rosamond Dry Lake, Roach Dry Lake, Alkali Dry Lake, and an unnamed dry lake near the town of Bonnie Claire in Nye County, Nevada. Unpaired meteorites have been found near one another on the same playa. Since 1963, 17 meteorite specimens (1.2-37.4 g), collectively called Lucerne Valley, have been found on Lucerne Dry Lake. Most appear to be completely covered with fusion crust, suggesting that their small size is due to fragmentation in the atmosphere and not to terrestrial weathering. The collection of meteorites on Lucerne Dry Lake is aided by the paucity of terrestrial rocks coarser than small pebbles; this is unusual for dry lakes in the region. Sixteen of the meteorite specimens from Lucerne Dy Lake were available for analysis.

  4. Visible and near-infrared (0.4-2.5 μm) reflectance spectra of playa evaporite minerals

    USGS Publications Warehouse

    Crowley, James K.

    1991-01-01

    Visible and near-infrared (VNIR; 0.4–2.4 μm) reflectance spectra were recorded for 35 saline minerals that represent the wide range of mineral and brine chemical compositions found in playa evaporite settings. The spectra show that many of the saline minerals exhibit diagnostic near-infrared absorption bands, chiefly attributable to vibrations of hydrogen-bonded structural water molecules. VNIR reflectance spectra can be used to detect minor hydrate phases present in mixtures dominated by anhydrous halite or thenardite, and therefore will be useful in combination with X ray diffraction data for characterizing natural saline mineral assemblages. In addition, VNIR reflectance spectra are sensitive to differences in sample hydration state and should facilitate in situ studies of minerals that occur as fragile, transitory dehydration products in natural salt crusts. The use of spectral reflectance measurements in playa studies should aid in mapping evaporite mineral distributions and may provide insight into the geochemical and hydrological controls on playa mineral and brine development.

  5. Temporal dynamics of salt crust patterns on a sodic playa: implications for aerodynamic roughness and dust emission potential

    NASA Astrophysics Data System (ADS)

    Nield, Joanna; Bryant, Robert; Wiggs, Giles; King, James; Thomas, David; Eckardt, Frank; Washington, Richard

    2015-04-01

    Salt pans (or playas) are common in arid environments and can be major sources of windblown mineral dust, but there are uncertainties associated with their dust emission potential. These landforms typically form crusts which modify both their erosivity and erodibility by limiting sediment availability, modifying surface and aerodynamic roughness and limiting evaporation rates and sediment production. Here we show the relationship between seasonal surface moisture change and crust pattern development on part of the Makgadikgadi Pans of Botswana (a Southern Hemisphere playa that emits significant dust), based on both remote-sensing and field surface and atmospheric measurements. We use high resolution (sub-cm) terrestrial laser scanning (TLS) surveys over weekly, monthly and annual timescales to accurately characterise crustal ridge thrusting and collapse. Ridge development can change surface topography as much as 30 mm/week on fresh pan areas that have recently been reset by flooding. The corresponding change aerodynamic roughness can be as much as 3 mm/week. At the same time, crack densities across the surface increase and this raises the availability of erodible fluffy, low density dust source sediment stored below the crust layer. We present a conceptual model accounting for the driving forces (subsurface, surface and atmospheric moisture) and feedbacks between these and surface shape that lead to crust pattern trajectories between highly emissive degraded surfaces and less emissive ridged or continuous crusts. These findings improve our understanding of temporal changes in dust availability and supply from playa source regions.

  6. Sedimentary facies and environmental ichnology of a ?Permian playa-lake complex in western Argentina

    USGS Publications Warehouse

    Zhang, G.; Buatois, L.A.; Mangano, M.G.; Acenolaza, F.G.

    1998-01-01

    A moderately diverse arthropod icnofauna occurs in ?Permian ephemeral lacustrine deposits of the Paganzo Basin that crop out at Bordo Atravesado, Cuesta de Miranda, western Argentina. Sedimentary successions are interpreted as having accumulated in a playa-lake complex. Deposits include three sedimentary facies: (A) laminated siltstone and mudstone: (B) current-rippled cross-laminated very fine grained sandstone: and (C) climbing and wave-rippled cross-laminated fine-grained sandstone deposited by sheet floods under wave influence in the playa-lake complex. Analysis of facies sequences suggests that repeated vertical facies associations result from transgressive regressive episodes of variable time spans. The Bordo Atravesado ichnofauna includes Cruziana problematica, Diplocraterion isp., cf. Diplopadichnus biformis, Kouphichnium? isp., Merostomichnites aicunai, Mirandaichnium famatinense, Monomorphichnus lineatus, Palaeophyeus tubularis, Umfolozia sinuosa and Umfolozia ef. U. longula. The assemblage is largely dominated by arthropod trackways and represents an example of the Scoyenia ichnofacies. Trace fossils are mostly preserved as hypichnial ridges on the soles of facies C beds, being comparatively rare in facies A and B. Ichnofossil preservation was linked to rapid influx of sand via sheet floods entering into the lake. Four taphonomic variants (types 1-4) are recognized, each determined by substrate consistency and time averaging. Type 1 is recorded by the presence of low density assemblages consisting of poorly defined trackways, which suggests that arthropods crawled in soft, probably slightly subaqueous substrates. Type 2 is represented by low to moderate density suites that include sharply defined trackways commonly associated with mud cracks, suggesting that the tracemakers inhabited a firm, desiccated lacustrine substrate. Type 3 displays features of types 1 and 2 and represents palimpsestic bedding surfaces, resulting from the overprint of terrestrial

  7. Effects of agricultural tillage and sediment accumulation on emergent plant communities in playa wetlands of the U.S. High Plains.

    PubMed

    O'Connell, Jessica L; Johnson, Lacrecia A; Daniel, Dale W; McMurry, Scott T; Smith, Loren M; Haukos, David A

    2013-05-15

    Identifying community assembly filters is a primary ecological aim. The High Plains, a 30 million ha short-grass eco-region, is intensely cultivated. Cultivation disturbance, including plowing and eroded soil deposition down-slope of plowing, influences plant composition in depressional wetlands, such as playas, within croplands. We evaluated influences of wetland cultivation and sediment deposition on plant composition in playas embedded within croplands (46 plowed and 32 unplowed) and native grasslands (79) across 6 High Plains' states. Sediment accumulation ranged from 7 to 78 cm in cropland and 1 to 35 cm in grassland playas. Deeper sediments and plowing each decreased wetland plant richness, 28% and 70% respectively in cropland wetlands. Sediment depth reduced richness 37% in small grasslands playas while it increased richness 22% in larger ones, suggesting moderate disturbance increased richness when there were nearby propagule sources. Sediment depth was unrelated to species richness in plowed wetlands, probably because plowing was a strong disturbance. Plowing removed perennial plants from vegetation communities. Sediment accumulation also influenced species composition in cropland playas, e.g., probability of Eleocharis atropurpurea increased with sediment depth, while probability of Panicum capillare decreased. In grassland playas, observed lighter sediment depths did not influence species composition after accounting for wetland area. Sediment accumulation and plowing shift wetland plant communities toward annual species and decrease habitat connectivity for wetland-dependent organisms in cropland playas over 39,000 and 23,400 ha respectively. Conservation practices lessening sediment accumulation include short-grass buffer strips surrounding wetlands. Further, wetland tillage, allowed under federal agricultural conservation programs, should be eliminated. PMID:23500104

  8. Eolian sand deposition during th Medieval Climatic Anomaly in Playa San Bartolo, Sonora, Mexico

    NASA Astrophysics Data System (ADS)

    Ortega, B.; Schaaf, P. E.; Murray, A.; Caballero, M.; Lozano Garcia, S.; Ramirez, A.

    2012-12-01

    Records of past climatic changes in desert environments are scarce due to the poor preservation of biological proxies. To overcome this lack we consider the paleoenvironmental significance and age of a lunette dune in the eastern rim of the Playa San Bartolo (PSB) in Sonoran Desert (Mexico). Rock magnetism, mineralogical, and geochemical analysis (major, trace and REE) allow assessment of sediment provenance and changes in the composition of the PSB dune over time. Thermoluminiscence and optical stimulated luminescence (TL and OSL) provide the chronology of lunette dune development. Dune sediments are composed by intercalated layers of sand beds and sandy silt strata. Variability in composition of dune sediments is attributed to changes in sediment sources. Mineralogical, geochemical and magnetic data show clear differences between the sand and the sandy silt of the PSB dune deposits, which suggest different sediment sources. Sand sized deposits, characterized by coarse magnetite grains, are mainly eroded from granitoids from nearby outcrops. Sandy silt deposits, rich in fine grained magnetite and evaporative minerals, resulted after the erosion of volcanic rocks and their soils from sierras at the NE of PSB during heavy rainfall episodes, the flooding of PSB and later deflation and accumulation in the dune of both detritic and authigenic components. The upper 6 m of dune accumulation occurred largely during AD 500 to 1200, a period that correlates with the Medieval climatic anomaly (AD 300 to 1300). These findings suggest that main dune accretion occurred during regionally extended drought conditions, disrupted by sporadic heavy rainfall.

  9. A spectral reflectance study (0.4-2.5 μm) of selected playa evaporite mineral deposits and related geochemical processes

    USGS Publications Warehouse

    Crowley, James K.

    1990-01-01

    Playa evaporite mineral deposits show major compositional variations related to differences in lithology, hydrology, and groundwater geochemistry. The use of visible and near-infrared (VNIR) spectral reflectance measurements as a technique for investigating the mineralogy of playa efflorescent crusts is examined. Samples of efflorescent crust were collected from 4 playa: Bristol Dry Lake, Saline Valley, Teels Marsh, and Rhodes Marsh--all located in eastern California and western Nevada. Laboratory and field spectral analyses coupled with X-ray diffraction analyses of the crusts yielded the following observations: VNIR spectra of unweathered salt crusts can be used to infer the general chemistry of near-surface brines; VNIR spectra are very sensitive for detecting minor hydrate mineral phases contained in mixtures with anhydrous, spectrally featureless, minerals such as halite (NaCl) and thernardite (Na2So4); borate minerals exhibit particularly strong VNIR spectral features that permit small amounts of borate to be detected in efflorescent salt crusts; remote sensing spectral measurements of playa efflorescent crusts may have applications in global studies of playa brines and minerals.

  10. Final Scientific/ Technical Report. Playas Grid Reliability and Distributed Energy Research

    SciTech Connect

    Romero, Van; Weinkauf, Don; Khan, Mushtaq; Helgeson, Wes; Weedeward, Kevin; LeClerc, Corey; Fuierer, Paul

    2012-06-30

    found that the benefits of net metering (like savings on investments in infrastructure and on meeting state renewables requirements) outweigh the costs (like the lowered revenue to cover utility infrastructure costs). Many are eagerly awaiting a California Public Utilities Commission study due later this year, in the hopes that it will provide a relatively unbiased look at the issue. Meanwhile, some states continue to pursue virtual net metering policies. Under Colorado’s Solar Gardens Act, for example, utility customers can subscribe to power generated somewhere other than their own homes. The program allowed by that bill sold out in 30 minutes, evidence of the pent-up demand for this kind of arrangement. And California solar advocates are hoping for passage of a “shared renewables” bill in that state, which would provide for similar solar are significant in bringing solar power to the estimated 75% (likely a conservative number) of can’t put solar on our own roof. As great a resource as the sun is, when it comes to actually implementing solar or other renewables, technology advances, policy changes, bureaucratic practices, and increased energy consciousness will all have to happen to achieve a 30% by 2050 national goal. This project incorporated research activities focused on addressing each of these challenges. First, the project researchers evaluated several leading edge solar technologies by actually implementing these technologies at Playas, New Mexico, a remote town built in the 1970s by Phelps Dodge Mining Company for the company’s employees. This town was purchased by the New Mexico Institute of Mining and Technology in 2005 and converted to a training and research center. Playas is an all-electric town served by a substation about seven miles away. The town is the last user on a 240 kV utility transmission line owned by the Columbus Electric Cooperative (CEC) making it easy to isolate for experiment purposes. The New Mexico Institute of Mining and

  11. The utilization of ERTS-1-generated photographs in the evaluation of the Iranian playas as potential locations for economic and engineering development. [water-borne sedimentation of playa lakes

    NASA Technical Reports Server (NTRS)

    Krinsley, D. B. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. False-color composites made from ratioed and stretched transparencies, generated from CCT's of ERTS-1, have enhanced hydrologic and morphologic differences within the playa surficial sediments. A composite of ratios 4/6, 5/7,15/61 and 4/7 using blue, red, yellow, and green, respectively, was useful in separating wet, water, and dry areas in the salt crust and for delineating smooth and rough salt where relief was less than 20 cm.

  12. Modeling aluminum-silicon chemistries and application to Australian acidic playa lakes as analogues for Mars

    NASA Astrophysics Data System (ADS)

    Marion, G. M.; Crowley, J. K.; Thomson, B. J.; Kargel, J. S.; Bridges, N. T.; Hook, S. J.; Baldridge, A.; Brown, A. J.; Ribeiro da Luz, B.; de Souza Filho, C. R.

    2009-06-01

    Recent Mars missions have stimulated considerable thinking about the surficial geochemical evolution of Mars. Among the major relevant findings are the presence in Meridiani Planum sediments of the mineral jarosite (a ferric sulfate salt) and related minerals that require formation from an acid-salt brine and oxidizing environment. Similar mineralogies have been observed in acidic saline lake sediments in Western Australia (WA), and these lakes have been proposed as analogues for acidic sedimentary environments on Mars. The prior version of the equilibrium chemical thermodynamic FREZCHEM model lacked Al and Si chemistries that are needed to appropriately model acidic aqueous geochemistries on Earth and Mars. The objectives of this work were to (1) add Al and Si chemistries to the FREZCHEM model, (2) extend these chemistries to low temperatures (<0 °C), if possible, and (3) use the reformulated model to investigate parallels in the mineral precipitation behavior of acidic Australian lakes and hypothetical Martian brines. FREZCHEM is an equilibrium chemical thermodynamic model parameterized for concentrated electrolyte solutions using the Pitzer approach for the temperature range from <-70 to 25 °C and the pressure range from 1 to 1000 bars. Aluminum chloride and sulfate mineral parameterizations were based on experimental data. Aluminum hydroxide and silicon mineral parameterizations were based on Gibbs free energy and enthalpy data. New aluminum and silicon parameterizations added 12 new aluminum/silicon minerals to this Na-K-Mg-Ca-Fe(II)-Fe(III)-Al-H-Cl-Br-SO 4-NO 3-OH-HCO 3-CO 3-CO 2-O 2-CH 4-Si-H 2O system that now contain 95 solid phases. There were similarities, differences, and uncertainties between Australian acidic, saline playa lakes and waters that likely led to the Burns formation salt accumulations on Mars. Both systems are similar in that they are dominated by (1) acidic, saline ground waters and sediments, (2) Ca and/or Mg sulfates, and (3) iron

  13. Modeling aluminum-silicon chemistries and application to Australian acidic playa lakes as analogues for Mars

    USGS Publications Warehouse

    Marion, G.M.; Crowley, J.K.; Thomson, B.J.; Kargel, J.S.; Bridges, N.T.; Hook, S.J.; Baldridge, A.; Brown, A.J.; Ribeiro da Luz, B.; de Souza, Filho C.R.

    2009-01-01

    Recent Mars missions have stimulated considerable thinking about the surficial geochemical evolution of Mars. Among the major relevant findings are the presence in Meridiani Planum sediments of the mineral jarosite (a ferric sulfate salt) and related minerals that require formation from an acid-salt brine and oxidizing environment. Similar mineralogies have been observed in acidic saline lake sediments in Western Australia (WA), and these lakes have been proposed as analogues for acidic sedimentary environments on Mars. The prior version of the equilibrium chemical thermodynamic FREZCHEM model lacked Al and Si chemistries that are needed to appropriately model acidic aqueous geochemistries on Earth and Mars. The objectives of this work were to (1) add Al and Si chemistries to the FREZCHEM model, (2) extend these chemistries to low temperatures (<0 ??C), if possible, and (3) use the reformulated model to investigate parallels in the mineral precipitation behavior of acidic Australian lakes and hypothetical Martian brines. FREZCHEM is an equilibrium chemical thermodynamic model parameterized for concentrated electrolyte solutions using the Pitzer approach for the temperature range from <-70 to 25 ??C and the pressure range from 1 to 1000 bars. Aluminum chloride and sulfate mineral parameterizations were based on experimental data. Aluminum hydroxide and silicon mineral parameterizations were based on Gibbs free energy and enthalpy data. New aluminum and silicon parameterizations added 12 new aluminum/silicon minerals to this Na-K-Mg-Ca-Fe(II)-Fe(III)-Al-H-Cl-Br-SO4-NO3-OH-HCO3-CO3-CO2-O2-CH4-Si-H2O system that now contain 95 solid phases. There were similarities, differences, and uncertainties between Australian acidic, saline playa lakes and waters that likely led to the Burns formation salt accumulations on Mars. Both systems are similar in that they are dominated by (1) acidic, saline ground waters and sediments, (2) Ca and/or Mg sulfates, and (3) iron

  14. Mapping Playa Evaporite Minerals, White Sands, New Mexico Using Landsat ETM+

    NASA Astrophysics Data System (ADS)

    Ghrefat, H. A.; Goodell, P. C.

    2002-12-01

    Evaporite minerals are the main source of several industrial and agricultural minerals important to the U.S. and world economy. Landsat ETM+ data covering the White Sands, New Mexico have been used in this study. The White Sands Dune Field, Lake Lucero, and Alkali Flat have been chosen as target sites. The study aims to determine the number of evaporite mineral endmembers that can be detected and mapped using Landsat ETM+. Furthermore, the study also aims to determine the spatial distribution of fractional abundances of evaporite mineral endmembers assuming a linear mixing model. The Minimum Noise Fraction (MNF) transform and Principal Component Analysis (PCA) were employed to determine a reduced set of noise-free spectral bands. The Pixel Purity Index (PPI) and n-D Visualization (nDV) were conducted on the reduced set of spectral bands to identify spectrally pure evaporite mineral endmembers in the image. Mineral maps of the spatial distribution and relative abundance of evaporite minerals were performed using two different algorithms: Spectral Angle Mapper (SAM) and Linear Spectral Unmixing (LSU). Four evaporite mineral endmembers have been identified using Spectral Angle Mapper. These minerals are gypsum, halite, calcite, and thenardite. The results of Linear Spectral Unmixing showed that the most common and abundant evaporite mineral in the White Sands is gypsum. The results of Spectral Angle Mapper (SAM) and Linear Spectral Unmixing (LSU) are validated by collecting field samples from different locations within the White Sands. A good match has been determined between results of Landsat ETM+ data and field and laboratory work. Mapping of playa evaporite minerals is of potential importance for the goal of saline soil characterization, regional groundwater hydrology and quality, and mineral resource development.

  15. [Biology and fishery of the lobster Panulirus gracilis in Playa Lagarto, Guanacaste, Costa Rica].

    PubMed

    Madrigal, Helven Naranjo

    2011-06-01

    Panulirus gracilis is a high valuable lobster species with considerable captures along the tropical Pacific coast. In this study, I present some biological and fishery parameters described after a sample of 843 lobsters, landed in Playa Lagarto from November 2007 to October 2008. From landing records, a total of 74.9% of lobsters were below the minimum legal catch size (80 mm CL). Carapace lengths were in the range of 42.8 and 143.6 mm for males and 115 and 35.8 mm for females. The size structure showed a wide overlapping of population segments, and a trend to increase with depth, where lung diving and "hooka" diving operations take place. Sex ratio was 1.36 M:H. The relationship between weight and LC revealed that females are heavier than males of the same size, and this difference was significant (p < 0.05). The von Bertalanffy growth parameters for males and females respectively (K = 0.45-0.38, LC(infinity) = 166.9-121.7) showed accelerated growth compared to other species. Males observed a higher growth rate than females. Furthermore, natural mortality (M), total mortality (Z) and fishing mortality (F) was higher in males (0.49-2.34-1.92) than in females (0.47-1.82-1.42). Recruitment was continuous for both sexes during the year, with an elevated intensity of 18.5% in July. Under the current fishing regime the population could be at risk of collapse, as indicated by the high exploitation rate (E) 0.80 PMID:21721230

  16. Saline Playas on Qinghai-Tibet Plateau as Mars Analog for the Formation-Preservation of Hydrous Salts and Biosignatures

    NASA Astrophysics Data System (ADS)

    Wang, A.; Zheng, M.; Kong, F.; Sobron, P.; Mayer, D. P.

    2010-12-01

    Qinghai-Tibet (QT) Plateau has the highest average elevation on Earth (~ 4500 m, about 50-60% of atmospheric pressure at sea-level). The high elevation induces a tremendous diurnal (and seasonal) temperature swing caused by high level of solar irradiation during the day and low level of atmospheric insulation during the evening. In addition, the Himalaya mountain chain (average height >6100 m) in the south of the QT Plateau largely blocks the pathway of humid air from the Indian Ocean, and produces a Hyperarid region (Aridity Index, AI ~ 0.04), the Qaidam Basin (N32-35, E90-100) at the north edge of the QT Plateau. Climatically, the low P, T, large ΔT, high aridity, and high UV radiation all make the Qaidam basin to be one of the most similar places on Earth to Mars. Qaidam basin has the most ancient playas (up to Eocene) and the lakes with the highest salinity on QT Plateau. More importantly, Mg-sulfates appear in the evaporative salts within the most ancient playas (Da Langtang) at the northwest corner of Qaidam basin, which mark the final stage of the evaporation sequence of brines rich in K, Na, Ca, Mg, Fe, C, B, S, and Cl. The evaporation minerals in the saline playas of Qaidam basin, their alteration and preservation under hyperarid conditions can be an interesting analog for the study of Martian salts and salty regolith. We conducted a field investigation at Da Langtan playa in Qaidam basin, with combined remote sensing (ASTER on board of NASA’s Terra satellite, 1.656, 2.167, 2.209, 2.62, 2.336, 2.40 µm), in situ sensing of a portable NIR spectrometer (WIR, 1.25-2.5 µm continuous spectral range), and the laboratory analyses of collected samples from the field (ASD spectrometer, 0.4 -2.5 µm, and Laser Raman spectroscopy). The results indicate that the materials contributing the high albedo layers in playa deposits are carbonate-gypsum-bearing surface soils, salt-clay-bearing exhaumed Pleistocene deposits, dehydrated Na-sulfates, hydrous Mg

  17. Potential transport pathways of dust emanating from the playa of Ebinur Lake, Xinjiang, in arid northwest China

    NASA Astrophysics Data System (ADS)

    Ge, Yongxiao; Abuduwaili, Jilili; Ma, Long; Wu, Na; Liu, Dongwei

    2016-09-01

    In this paper, the HYSPLIT model, driven with reanalysis meteorological data from 1978 to 2013, was used to understand the potential transport characteristics of dust and salt dust emanating from the playa of Ebinur Lake in arid northwest China. Daily air parcel trajectories were computed forward for 8 days from an origin centered over Ebinur Lake at 100 m above ground level. Air parcel trajectory density plots were mapped for seven levels: 0-100 m agl., 100-500 m agl., 500-1000 m agl., 1000-1500 m agl., 1500-2000 m agl., 2000-3000 m agl., and 3000-5000 m agl. These show that potential dust transport pathways have clear seasonal differentiation. The potential transport distance of dust and salt dust is greatest in spring and summer. In autumn and winter, the potential transport of the high-density air trajectory is below 1000 m traveling a shorter distance. Potential dust transport pathways showed notifying directivity in different seasons and heights. Southeast in spring and summer, and north to northeast in autumn and winter are the two main potential transport channels of dust and salt dust. Accordingly, dust and salt dust from the playa of Ebinur Lake may influence the atmospheric processes and biogeochemical cycles of a vast region. The main area of influence of dust and salt dust is close to the source area, and will significantly accelerate the melting of snow and ice in the Tianshan Mountains. This highlights the urgent need to combine remote sensing, isotope and other methods to further research the transport characteristics of dust and salt dust from the playa of the Ebinur Lake.

  18. Subsidence beneath a playa basin on the Southern High Plains, U. S. A. Evidence from shallow seismic data

    SciTech Connect

    Paine, J.G. )

    1994-02-01

    Shallow seismic data from Sevenmile Basin, a large ephemeral lake (playa) basin in the Texas Panhandle, reveal that subsidence has been an important agent in basin formation. Sevenmile Basin is 5.5 x 3.6 km across and 14 m deep and contains 20 m of lacustrine and eolian sediments that interfinger with the Quaternary Blackwater Draw Formation. Seismic reflection and refraction data were collected from the unlithified and variably saturated clastic sequence beneath Seven-mile Basin to investigate the geological history and hydrogeological framework of playa basins, which recharge the regionally important Ogallala aquifer. Three-layer velocity models provide good solutions for reversed refraction data. Near-surface p-wave velocities (layer 1) range from 349 to 505 m/s, layer 2 velocities range from 806 to 851 m/s, and layer 3 velocities range from 2,037 to 2,161 m/s. Shallow test holes and drillers' logs suggest that layer 1 is composed of playa and upper Blackwater Draw Formation deposits, layer 2 consists of lower Blackwater Draw Formation and upper Ogallala Formation deposits, and layer 3 represents a competent and partly saturated zone near the top of the Ogallala aquifer. Reflection sections show a middle Ogallala reflector, a reflector at the top of Permian or Triassic bedrock, and internal bedrock reflectors that indicate a structural low beneath Sevenmile Basin. Increasing relief with age, from 14 m at the surface to 70 m on the middle Ogallala reflector to 110 m at the base of the Ogallala, is interpreted as evidence of subsidence of underlying Permian evaporite-bearing strata before or during Ogallala deposition. 29 refs., 12 figs., 2 tabs.

  19. Mapping compositional and particle size variations across Silver Lake Playa: Relevance to analyses of Mars TIR data

    NASA Technical Reports Server (NTRS)

    Petroy, S. B.; Arvidson, Raymond E.; Kahle, A. B.

    1991-01-01

    The high spectral and spatial resolution thermal infrared (TIR) data to be acquired from the upcoming Mars Observer-Thermal Emission Spectra (TES) mission will map the composition and texture of the Martian sediments. To prepare for these data, portions of two remote sensing experiments were conducted to test procedures for extracting surface property information from TIR data. Reported here is the continuing analysis of Thermal Infrared Multispectral Scanner (TIMS) data, field emission spectra, laboratory Fourier Transform Infrared (FTIR) reflectance spectra, and field observations with respect to the physical characteristics (composition, emissivity, etc.) of Silver Lake playa in southern California.

  20. Eolian sediments generated by anthropogenic disturbance of playas: human impacts on the geomorphic system and geomorphic impacts on the human system

    NASA Astrophysics Data System (ADS)

    Gill, Thomas E.

    1996-09-01

    In many of the Earth's arid and semiarid lands, saline lakes, playas, and similar landforms are disturbed as a result of human activity. Diversion and/or consumptive use of surface or groundwaters has created the effect of a climate change in numerous drainage basins, resulting in the desiccation of lakes and reactivation of eolian processes at many locations. Playas are natural sites for extensive eolian activity because of the deposition of clastic and chemical sediments in basins by surface water (via fluvial transport) and groundwater (via efflorescence). Wind erosion and deposition of playa sediments has had a major role in the development of landforms and sedimentary units in the present (lunette fields worldwide; Simpson Desert, Australia) and geological past, from the Triassic (Mercia Mudstone, England) to the Quaternary (Lahontan Basin and Cima Volcanic Field, USA). Anthropogenic disturbance or desiccation of playa systems has resulted in the eolian transport of sand (e.g. Lop Nor, China; Konya Basin, Turkey; Rajasthan, India; Kappakoola, Australia; several sites in West Africa) and/or dust (e.g. Aral Sea, Kazakhstan/Uzbekistan; Old Wives Lake, Canada; Kara Bogaz Gol, (ex-)USSR; Lake Texcoco, Mexico; Owens (dry) Lake, Mono Lake and other playas, USA). Typically, this is accomplished by abstraction of water and/or removal of vegetation from terminal lake basins. An extensive review of the literature documents many examples and/or potential examples of such phenomena in numerous nations. The reactivation of eolian processes from closed basins produces air pollution in the form of fugitive dust (naturally occurring compounds released into the atmosphere by human actions), and has significant environmental and economic impacts on human activities in the surrounding areas. Restoration or mitigation of degraded land on or surrounding playas has been accomplished at Lake Texcoco, Kara Bogaz Gol and the Konya Basin, and is being actively implemented at Mono Lake

  1. Building on previous OSL dating techniques for gypsum: a case study from Salt Basin playa, New Mexico and Texas

    USGS Publications Warehouse

    Mahan, Shannon; Kay, John

    2012-01-01

    The long term stability and reliability of the luminescence signal for gypsum has not been well documented or systematically measured until just recently. A review of the current literature for luminescence dating of gypsum is compiled here along with original efforts at dating an intact and in-situ bed of selenite gypsum at Salt Basin Playa, New Mexico and Texas. This effort differs from other documented luminescence dating efforts because the gypsum is not powdery or redistributed from its original growth patterns within the playa basin but is instead of a crystalline form. Sixteen ages from eight cores were ultimately produced with seven of the ages coming from rare detrital quartz encased in or with the gypsum crystals while the remaining ages are from the crystalline gypsum. As far as can be ascertained, the quartz was measured separately from the gypsum and no contaminants were noted in any of the aliquots. Some basic and preliminary tests of signal stability were measured and found to be mitigated by lessening of pre-heat protocols. Ages ranged from 8 ka to 10 ka in the shallow cores and 16 ka to 22 ka in the deeper cores. These ages will be useful in determining rates of gypsum growth within a sequence of evaporates which, in turn, will help to better document historic rates of evaporation and thus estimate, with more precision, the corresponding annual evaporation rates.

  2. A new ranavirus isolated from Pseudacris clarkii tadpoles in playa wetlands in the southern High Plains, Texas.

    PubMed

    Torrence, Shannon M; Green, D Earl; Benson, Catherine J; Ip, Hon S; Smith, Loren M; McMurry, Scott T

    2010-06-01

    Mass die-offs of amphibian populations pose a challenging problem for conservation biologists. Ranaviruses often cause systemic infections in amphibians and, in North America, are especially virulent and lethal to larvae and metamorphs. In this paper we describe a novel ranavirus isolate as well as the first recorded occurrence of ranavirus in the southern High Plains of Texas and in associated populations of the spotted chorus frog Pseudacris clarkii. The breeding sites were playas, that is, wetlands that fill via isolated thunderstorms that can occur infrequently; thus, not every playa has water or breeding amphibians annually. We did not detect ranavirus in sympatric anurans, but other reports document ranaviruses in Pseudacris spp. elsewhere. The occurrence of multiple isolates of ranavirus in a number of Pseudacris species suggests that this genus of frogs is highly susceptible to ranaviruses and may experience exceptionally high mortality rates from infection. Thus, the virus may contribute to substantial seasonal population declines and low seasonal recruitment, with negative impacts on populations of breeding adults in successive years. PMID:20848879

  3. Geologic investigation of Playa Lakes, Tonopah Test Range, Nevada : data report.

    SciTech Connect

    Rautman, Christopher Arthur

    2004-12-01

    Subsurface geological investigations have been conducted at two large playa lakes at the Tonopah Test Range in central Nevada. These characterization activities were intended to provide basic stratigraphic-framework information regarding the lateral distribution of ''hard'' and ''soft'' sedimentary materials for use in defining suitable target regions for penetration testing. Both downhole geophysical measurements and macroscopic lithilogic descriptions were used as a surrogate for quantitative mechanical-strength properties, although some quantitative laboratory strength measurements were obtained as well. Both rotary (71) and core (19) holes on a systematic grid were drilled in the southern half of the Main Lake; drill hole spacings are 300 ft north-south and 500-ft east-west. The drilled region overlaps a previous cone-penetrometer survey that also addressed the distribution of hard and soft material. Holes were drilled to a depth of 40 ft and logged using both geologic examination and down-hole geophysical surveying. The data identify a large complex of very coarse-grained sediment (clasts up to 8 mm) with interbedded finer-grained sands, silts and clays, underlying a fairly uniform layer of silty clay 6 to 12 ft thick. Geophysical densities of the course-grained materials exceed 2.0 g/cm{sup 2}, and this petrophysical value appears to be a valid discriminator of hard vs. soft sediments in the subsurface. Thirty-four holes, including both core and rotary drilling, were drilled on a portion of the much larger Antelope Lake. A set of pre-drilling geophysical surveys, including time-domain electromagnetic methods, galvanic resistivity soundings, and terrain-conductivity surveying, was used to identify the gross distribution of conductive and resistive facies with respect to the present lake outline. Conductive areas were postulated to represent softer, clay-rich sediments with larger amounts of contained conductive ground water. Initial drilling, consisting of

  4. Microclimate of a desert playa: evaluation of annual radiation, energy, and water budgets components

    NASA Astrophysics Data System (ADS)

    Malek, Esmaiel

    2003-03-01

    We set up two automatic weather stations over a playa (the flat floor of an undrained desert basin that, at times, becomes a shallow lake), approximately 65 km east-west by 130 km north-south, located in Dugway (40° 08N, 113° 27W, 1124 m above mean sea level) in northwestern Utah, USA, in 1999. These stations measured the radiation budget components, namely: incoming Rsi and outgoing Rso solar or shortwave radiation, using two Kipp and Zonen pyranometers (one inverted), the incoming Rli (or atmospheric) and outgoing Rlo (or terrestrial) longwave radiation, using two Kipp and Zonen pyrgeometers (one inverted) during the year 2000. These sensors were ventilated throughout the year to prevent dew and frost formation. Summation of these components yields the net radiation Rn. We also measured the air temperatures and humidity at 1 and 2 m and the soil moisture and temperature (Campbell Sci., Inc., CSI) to evaluate the energy budget components (latent (LE), sensible (H), and the soil (Gsur) heat fluxes). The 10 m wind speed U10 and direction (R.M. Young wind monitor), precipitation (CSI), and the surface temperature (Radiation and Energy Balance Systems, REBS) were also measured during 2000. The measurements were taken every 2 s, averaged into 20 min, continuously, throughout the year 2000. The annual comparison of radiation budget components indicates that about 34% of the annual Rsi (6937.7 MJ m-2 year-1) was reflected back to the sky as Rso, with Rli and Rlo amounting to 9943.4 MJ m-2 year-1 and 12 789.7 MJ m-2 year-1 respectively. This yields about 1634.3 MJ m-2 year-1 as Rn, which is about 24% of the annual Rsi. Of the total 1634.3 MJ m-2 year-1 available energy, about 25% was used for the process of evaporation (LE) and 77% for heating the air (H). The annual heat contribution from the soil to the energy budget amounted to 2% during the experimental period. Our studies showed that the total annual measured precipitation amounted to 108.0 mm year-1 during the

  5. Geologic and paleoseismic study of the Lavic Lake fault at Lavic Lake Playa, Mojave Desert, Southern California

    USGS Publications Warehouse

    Rymer, M.J.; Seitz, G.G.; Weaver, K.D.; Orgil, A.; Faneros, G.; Hamilton, J.C.; Goetz, C.

    2002-01-01

    Paleoseismic investigations of the Lavic Lake fault at Lavic Lake playa place constraints on the timing of a possible earlier earthquake along the 1999 Hector Mine rupture trace and reveal evidence of the timing of the penultimate earthquake on a strand of the Lavic Lake fault that did not rupture in 1999. Three of our four trenches, trenches A, B, and C, were excavated across the 1999 Hector Mine rupture; a fourth trench, D, was excavated across a vegetation lineament that had only minor slip at its southern end in 1999. Trenches A-C exposed strata that are broken only by the 1999 rupture; trench D exposed horizontal bedding that is locally warped and offset by faults. Stratigraphic evidence for the timing of an earlier earthquake along the 1999 rupture across Lavic Lake playa was not exposed. Thus, an earlier event, if there was one along that rupture trace, predates the lowest stratigraphic level exposed in our trenches. Radiocarbon dating of strata near the bottom of trenches constrains a possible earlier event to some time earlier than about 4950 B.C. Buried faults revealed in trench D are below a vegetation lineament at the ground surface. A depositional contact about 80 cm below the ground surface acts as the upward termination of fault breaks in trench D. Thus, this contact may be the event horizon for a surface-rupturing earthquake prior to 1999-the penultimate earthquake on the Lavic Lake fault. Radiocarbon ages of detrital charcoal samples from immediately below the event horizon indicate that the earthquake associated with the faulting occurred later than A.D. 260. An approximately 1300-year age difference between two samples at about the same stratigraphic level below the event horizon suggests the potential for a long residence time of detrital charcoal in the area. Coupled with a lack of bioturbation that could introduce young organic material into the stratigraphic section, the charcoal ages provide only a maximum bounding age; thus, the recognized

  6. The utilization of ERTS-1-generated photographs in the evaluation of the Iranian playas as potential locations for economic and engineering development

    NASA Technical Reports Server (NTRS)

    Krinsley, D. B. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. Seasonal monitoring of hydrologic conditions at three playa lakes provides a basis for constructing an annual water inventory for these lakes. Although the extreme variation in the extent of playa lakes must be considered, the principal periods of their fluctuations are generally constant. Playa lakes provide an important water source for arid region needs, and their water can be diverted and stored for use during the long, hot, and dry summer. At their 1973 maxima, approximately 400 million cu m and 794 million cu m of water were available at the lakes at Qom and Neriz playas, respectively. These lakes adjoin areas of moderately dense population that have severe annual water deficits. A preliminary road alignment across the Great Kavir in north-central Iran has been prepared from an analysis of ERTS-1 images of that area from September 2, 1972, through May 12, 1973, a total of 6 scenes. An all-weather road constructed along this alignment could reduce the distance between points north and south of the Great Kavir by as much as 700 km.

  7. Playa-lake basins on the Southern High Plains of Texas and New Mexico: Part II. A hydrologic model and mass-balance arguments for their development.

    USGS Publications Warehouse

    Wood, W.W.; Osterkamp, W.R.

    1987-01-01

    Hydrologic, geologic, geomorphic, and mass-balance data suggest that most of the approx. 30 000 playa lake basins on the Southern High Plains have developed by a combination of dissolution of caliche and piping of surface material into the unsaturated zone rather than by eolian processes as has generally been stated.-from Authors

  8. Unravelling aquifer-wetland interaction using CSAMT and gravity methods: the Mollina-Camorra aquifer and the Fuente de Piedra playa-lake, southern Spain

    NASA Astrophysics Data System (ADS)

    Pedrera, A.; Martos-Rosillo, S.; Galindo-Zaldívar, J.; Rodríguez-Rodríguez, M.; Benavente, J.; Martín-Rodríguez, J. F.; Zúñiga-López, M. I.

    2016-06-01

    The hydrological regime of Fuente de Piedra playa-lake (Málaga, southern Spain) has been significantly affected by the intensive exploitation of groundwater in the area. The playa-lake is situated above clays, marls, and gypsum, and under unaltered conditions received surface-subsurface runoff within the watershed as well as groundwater discharge from two carbonate aquifers. We have analyzed the structure of the main one, the Mollina-Camorra carbonate aquifer, by combining controlled source audio magnetotellurics (CSAMT), gravity prospecting, and time-domain electromagnetic (TDEM) soundings. This geophysical information, together with new structural and hydrogeological data, was gathered to develop a new conceptual hydrogeological model. This model allows the hydrological linkage of the carbonate aquifer with the playa-lake system to be established. Moreover, the intensive exploitation in the carbonate aquifer, even outside the watershed of the playa-lake, has affected the hydrological regime of the system. This multidisciplinary work demonstrates the potential of geophysical methods for understanding wetland-aquifer interaction, having important groundwater management implications.

  9. Exploring Variability in Acidic Saline Playa Lakes in WA with HyMAP Hyperspectral Data

    NASA Astrophysics Data System (ADS)

    Baldridge, A. M.; Hook, S. J.; Souza Filho, C. R.; Thomson, B. J.; Bridges, N. T.; Crowley, J. K.

    2009-12-01

    Acid saline lakes in Western Australia have been recognized as useful chemical terrestrial analogs for aqueous mineral formation on Mars [e.g., 1]. In these lake systems, large pH and salinity differences are observed both laterally and vertically over scales of a few tens of meters[2, 3]. The variability in these lakes have been offered as an alternate formation mechanism for some of the phyllosilicates and sulfates on Mars, suggesting that these different mineral types may be separated by chemical gradients rather than by temporal boundaries[4]. To assess the ability to detect this variability remotely and to determine the extent of the surface variability, which may not be easily accessible in the field, spectral mapping for two of the acidic saline playa lakes was performed. HyMAP airborne data were acquired in December, 2008, of Lake Gilmore and Lake Chandler in WA. The HyMAP sensors have 126 bands that cover the wavelength range between 0.45 and 2.5 µm. Hyvista Corporation provided atmospherically corrected surface reflectance data at approximately 3m spatial resolution. Using the methodology described by [5] the HyMAP data were analyzed using ENVI to identify spectrally pure endmembers that can be used to distinguish mineralogy in the scene. Relevant (e.g. not roads, water or vegetation) spectral endmembers derived for each scene were identified visually using spectra from the ASTER spectral library[6]. The processing techniques were applied to all flight lines and ultimately a classification map mosaic was produced for selection of relevant and intriguing field sampling sites. The classification maps will be validated using field spectroscopy and visual inspection of representative samples collected from the field sites in October 2009, and laboratory spectroscopy and X-ray diffraction will be performed for further validation. The classification maps confirm variability in mineralogy across the lakes, validating geochemical modeling. There are also some

  10. Comparison of flood hazard assessments on desert piedmonts and playas: A case study in Ivanpah Valley, Nevada

    NASA Astrophysics Data System (ADS)

    Robins, Colin R.; Buck, Brenda J.; Williams, Amanda J.; Morton, Janice L.; House, P. Kyle; Howell, Michael S.; Yonovitz, Maureen L.

    2009-02-01

    Accurate and realistic characterizations of flood hazards on desert piedmonts and playas are increasingly important given the rapid urbanization of arid regions. Flood behavior in arid fluvial systems differs greatly from that of the perennial rivers upon which most conventional flood hazard assessment methods are based. Additionally, hazard assessments may vary widely between studies or even contradict other maps. This study's chief objective was to compare and evaluate landscape interpretation and hazard assessment between types of maps depicting assessments of flood risk in Ivanpah Valley, NV, as a case study. As a secondary goal, we explain likely causes of discrepancy between data sets to ameliorate confusion for map users. Four maps, including three different flood hazard assessments of Ivanpah Valley, NV, were compared: (i) a regulatory map prepared by FEMA, (ii) a soil survey map prepared by NRCS, (iii) a surficial geologic map, and (iv) a flood hazard map derived from the surficial geologic map, both of which were prepared by NBMG. GIS comparisons revealed that only 3.4% (33.9 km 2) of Ivanpah Valley was found to lie within a FEMA floodplain, while the geologic flood hazard map indicated that ~ 44% of Ivanpah Valley runs some risk of flooding (Fig. 2D). Due to differences in mapping methodology and scale, NRCS data could not be quantitatively compared, and other comparisons were complicated by differences in flood hazard class criteria and terminology between maps. Owing to its scale and scope of attribute data, the surficial geologic map provides the most useful information on flood hazards for land-use planning. This research has implications for future soil geomorphic mapping and flood risk mitigation on desert piedmonts and playas. The Ivanpah Valley study area also includes the location of a planned new international airport, thus this study has immediate implications for urban development and land-use planning near Las Vegas, NV.

  11. Impact of Diagenesis on Biosignature Preservation Potential in Playa Lake Evaporites in Verde Formation, Arizona: Implications for Mars Exploration

    NASA Astrophysics Data System (ADS)

    Shkolyar, S.; Farmer, J. D.

    2015-12-01

    Major priorities for Mars science include assessing the preservation potential and impact of diagenesis on biosignature preservation in aqueous sedimentary environments. We address these priorities with field and lab studies of playa evaporites of the Verde Formation (upper Pliocene) in Arizona. Evaporites studied include bottom-nucleated halite and displacive growth gypsum in magnesite-rich mudstone. These lithotypes are potential analogs for ancient lacustrine habitable environments on Mars. This study aimed to understand organic matter preservation potential under different diagenetic histories. Methods combined outcrop-scale field observations and lab analyses, including: (1) thin-section petrography to understand diagenetic processes and paragenesis; (2) X-ray powder diffraction to obtain bulk mineralogy; (3) Raman spectroscopy to identify and place phases (and kerogenous fossil remains) within a microtextural context; (4) Total Organic Carbon (TOC) analyses to estimate weight percentages of preserved organic carbon for each subfacies endmember; and (5) electron microprobe to create 2D kerogen maps semi-quantifying kerogen preservation in each subfacies. Results revealed complex diagenetic histories for each evaporite subfacies and pathways for organic matter preservation. Secondary gypsum grew displacively within primary playa lake mudstones during early diagenesis. Mudstones then experienced cementation by Mg-carbonates. Displacive-growth gypsum was sometimes dissolved, forming crystal molds. These molds were later either infilled by secondary sulfates or recrystallized to gypsum pseudomorphs with minor phases present (i.e., glauberite). These observations helped define taphonomic models for organic matter preservation in each subfacies. This work has the potential to inform in situ target identification, sampling strategies, and data interpretations for future Mars Sample Return missions (e.g., sample caching strategies for NASA's Mars 2020 mission).

  12. Late Holocene evolution of playa lakes in the central Ebro depression based on geophysical surveys and morpho-stratigraphic analysis of lacustrine terraces

    NASA Astrophysics Data System (ADS)

    Gutiérrez, F.; Valero-Garcés, B.; Desir, G.; González-Sampériz, P.; Gutiérrez, M.; Linares, R.; Zarroca, M.; Moreno, A.; Guerrero, J.; Roqué, C.; Arnold, L. J.; Demuro, M.

    2013-08-01

    The origin and morpho-stratigraphic evolution of the largest playa-lake system (La Playa-El Pueyo) in the Bujaraloz-Sástago endorheic area, located in the semiarid central sector of the Ebro Depression, are analysed. The enclosed depressions are developed on gypsiferous Tertiary bedrock and show a prevalent WNW-ESE orientation parallel to the direction of the prevalent strong local wind (Cierzo). Yardangs have been carved in bedrock and unconsolidated terrace deposits in the leeward sector of the largest lake basins. A sequence of three lacustrine terrace levels has been identified by detailed geomorphological mapping. The treads of the upper, middle and lower terrace levels are situated at + 9 m, + 6 m and + 0.5 m above the playa-lake floors, respectively. Seismic refraction and electrical resistivity profiles acquired in La Playa reveal a thin basin fill (~ 2 m) with a planar base. These data allow ruling out the genetic hypothesis for the depressions involving the collapse of large bedrock cavities and support a mixed genesis of combined widespread dissolution and subsidence by groundwater discharge and eolian deflation during dry periods. The 5 m thick deposit of the middle terrace was investigated in hand-dug and backhoe trenches. Six AMS radiocarbon ages from this terrace indicate an aggradation phase between 3.9 ka and ca. 2 ka. These numerical ages yield a maximum average aggradation rate of 2.6 mm/yr and a minimum excavation rate by wind deflation of 3 mm/yr subsequent to the accumulation of the middle terrace. The latter figure compares well with those calculated in several arid regions of the world using yardangs carved in palaeolake deposits. The aggradation phase between 4 and 2 ka is coherent with other Iberian and Mediterranean records showing relatively more humid conditions after 4 ka, including the Iron Ages and the Iberian-Roman Period.

  13. Evaporite-mineral Dusts From a Dry Saline Playa in the Mojave Desert and Bioaccessibility of Their Trace Metals

    NASA Astrophysics Data System (ADS)

    Reynolds, R. L.; Breit, G. N.; Goldstein, H.; Morman, S.; Reheis, M. C.; Yount, J. C.; Bogle, R.; Vogel, J.; Ballantine, J.; King, J.

    2008-12-01

    Evaporite-rich sediments commonly form on the surfaces of dust-emitting dry saline lakes, including wet playas, where the depth to the saturated zone is less than about 4 m. These sediments may contain high levels of toxic metals and metalloids, but many important aspects about these kinds of settings remain poorly known: Conditions that promote and suppress dust emission; chemical relations among ground water, salt- rich crusts, and salt-rich dust; bioaccessibility of metals and metalloids in dust; and controls of human activity and climatic variability on dust emission and on metal contents of dust. A dust-emitting area in the Mojave Desert provides a setting where these factors can be evaluated. The area encompasses Ash Meadows to the north where dilute waters (0.7 mS/cm) both discharge and evaporate and Franklin Lake playa (FLP) about 20 km south where saline ground water (90 mS/cm) evaporates. These features are linked by north-to-south flow of shallow ground water in a confined aquifer beneath Carson Slough that has intermediate salinity (1.5- 16 mS/cm). In ground water at FLP, maximum dissolved concentrations of arsenic (16 mg/L), molybdenum (12 mg/L), selenium (0.7 mg/L), tungsten (0.3 mg/L), and uranium (4 mg/L) are explained by evaporative concentration. Monitoring of dust emission from FLP between March 2005 and April 2008, mainly using digital cameras triggered automatically by wind speeds greater than 4.5 m/s, reveals that aridity suppressed dust emission, whereas wet periods promoted dust emission by generating loose accumulations of salt minerals or thin salt crusts that are vulnerable to wind erosion. Samples of dust taken by a portable wind tunnel and of salt crusts contain highly variable contents of toxic metals and metalloids that have high levels of bioaccessibility when leached in fluids that simulate human gastric, intestinal, and lung fluids, with respective pHs of 1.5, 5.5, and 7.4. The levels of bioaccessible toxic substances correspond

  14. Groundwater Modeling of Playa-Focused Recharge at the Southwestern Edge of the High Plains Aquifer in West Texas

    NASA Astrophysics Data System (ADS)

    Blainey, J.; Pickens, J. F.; grisak, G. E.; Holt, R. M.; Sigda, J.; Cook, S.; Hughes, E.

    2011-12-01

    Ongoing hydrogeologic investigations at a licensed low-level radioactive waste disposal site in Andrews County, Texas include monitoring of a groundwater system in Ogallala (Neogene), Antlers (Cretaceous), and Gatuna (Neogene/Quaternary) Formation sediments on the southwestern edge of the Southern High Plains physiographic province. The disposal site is underlain by unsaturated sands and gravels of these laterally contiguous sediments, informally termed the OAG. North of the site these sediments develop into the continuously saturated High Plains or Ogallala aquifer. Episodes of focused recharge to the OAG sediments have been observed during the last 9 years of groundwater level monitoring near small playas and topographic depressions that collect water after large precipitation events. During smaller precipitation events water is stored in the unsaturated zone and evapotranspired, predominately by mesquite, creosote and grasses. The climate is semi-arid with average evaporation rates far exceeding the estimated average annual precipitation of 15-16 inches/year. Monitoring at more than 250 wells in the OAG and environmental tracer studies confirm a conceptual model of playa-focused natural recharge to the groundwater system with little or no recharge occurring in inter-playa areas. The thickness of the OAG saturated sediments in the vicinity of the disposal sites ranges from 3 feet to 10 feet, with areas of discontinuous saturation away from areas of focused recharge. Environmental tracer studies show the groundwater in the OAG is poorly mixed and disconnected from regional groundwater flow further to the northeast. The disposal facilities are located over a structural high on the erosional surface of the Dockum Group, which immediately underlies the OAG sediments. This feature, referred to as the red bed ridge, is roughly coincident with the topographic divide between the High Plains and the Pecos Valley physiographic provinces and serves as a divide for

  15. A Br Isotopic Study of Australian Arid Playa Lakes and halophyte vegetation as a monitor of Br transport

    NASA Astrophysics Data System (ADS)

    Schaefer, B. F.

    2014-12-01

    Bromine possesses a chemistry broadly comparable to that of Cl and F, however its heavier mass and lower abundance results in slightly different behaviours in geochemical cycling. For example it is disproportionately enriched in sea water with respect to Cl. Br can be considered to be a "hydrophile" element, and hence its behaviour is in governed by that of water. It possesses two isotopes 79Br (50.686%) and 81Br (49.314%). This study has developed new chemical extraction, and most significantly, new mass spectrometric protocols for Br isotopes on silicates, evaporites and waters using N-TIMS methodologies. Existing CF-IRMS methodologies offer internal precision of ~0.3‰ (1SD, [1]), whereas N-TIMS measurements of laboratory HBr and seawater standards produce external reproducibility of <0.07‰ (1SD) over an 18 month period with internal precision typically <0.06‰ (1SD) on single analyses. This study presents the first high precision, N-TIMS isotopic data on playa lake evaporites, recording a >5‰ variation in solar system 81Br/79Br. Also presented is data from the analysis of the halophylic saltbush (sp Atriplex) adjacent to the lakes to constrain biological fractionation of Br isotopes. Variations of ~4‰ are observed between the lakes with a comparable shift for the leaves of the saltbush. [1] Shouaker-Stash et al., Anal. Chem, 77; p4027-4033, 2005.

  16. Specificity of the chemical and mineralogical composition of salts in solonchak playas and lakes of the Kulunda steppe

    NASA Astrophysics Data System (ADS)

    Lebedeva (Verba), M. P.; Lopukhina, O. V.; Kalinina, N. V.

    2008-04-01

    The chemical composition of water in 44 lakes of the Kulunda steppe has been studied. It is shown that solute concentrations in different lakes vary from 1 to 390 g/l. Four chemical types of the water salinity—chloride, sulfate, chloride-sulfate with the presence of sodium bicarbonate, and sodic waters—are distinguished. The nature of the water alkalinity has been studied in 12 lakes. In the lakes with neutral chloride and sulfate salts, the total alkalinity does not exceed 16.56 meq/l. In the lakes with the presence of soda, it reaches 189 meq/l. In sodic waters, the total alkalinity varies from 600 to 1504.6 meq/l. In the latter case, the water alkalinity is conditioned by the presence of soda and borate salts. Salt minerals in the bottom sediments and in the salt crusts of solonchakous playas around the lakes are represented by halite, calcite, dolomite, and thenardite. In two salt crusts, the presence of soda and trona has been diagnosed.

  17. Changes in water level, land use, and hydrological budget in a semi-permanent playa lake, southwest Spain.

    PubMed

    Rodríguez-Rodríguez, M; Green, A J; López, R; Martos-Rosillo, S

    2012-01-01

    Medina playa lake, a Ramsar site in western Andalusia, is a brackish lowland lake of 120 ha with an average depth of 1 m. Water flows into Medina from its 1,748-ha watershed, but the hydrology of the lake has not previously been studied. This paper describes the application of a water budget model on a monthly scale over a 6-year period, based on a conceptual hydrological model, and considers different future scenarios after calibration to improve the understanding of the lake's hydrological functioning. Climatic variables from a nearby weather station and observational data (water-level evolution) were used to develop the model. Comparison of measured and predicted values demonstrated that each model component provided a reasonable output with a realistic interaction among the components. The model was then used to explore the potential consequences of land-use changes. Irrigation of olive groves would significantly reduce both the hydroperiod (becoming dry 15% of the time) and the average depth of the lake (water level <0.5 m 40% of the time). On the other hand, removal of an artificial overflow would double the average flooded surface area during high-water periods. The simulated water balance demonstrates that the catchment outputs are dominated by lake evaporation and surface outflow from the lake system to a creek. Discrepancies between predicted and observed water levels identify key areas of uncertainty for future empirical research. The study provides an improved basis for future hydrological management of the catchment and demonstrates the wider utility of this methodology in simulating this kind of system. This methodology provides a realistic appraisal of potential land-use management practices on a catchment-wide scale and allows predictions of the consequences of climate change. PMID:21461983

  18. Analysis of polygonal cracking patterns in chloride-bearing terrains on Mars: Indicators of ancient playa settings

    NASA Astrophysics Data System (ADS)

    El-Maarry, M. R.; Pommerol, A.; Thomas, N.

    2013-11-01

    ancient southern highlands on Mars (~3.5 Gyr old) contain > 600 regions that display spectral evidence in the infrared for the presence of chloride-bearing materials. Many of these locations were previously reported to display polygonal cracking patterns. We studied more than 80 of the chloride-bearing terrains using high-resolution (0.25-0.5 m/pixel) images, as well as near-infrared spectral data, to characterize the surface textures and the associated cracking patterns and mineralogies. Our study indicates that ~75% of the studied locations display polygonal cracks that resemble desiccation cracks, while some resemble salt expansion/thrust polygons. Furthermore, we detect, spectrally, the presence of smectites in association with ~30% of the studied fractured terrains. We note that smectites are a special class of swelling clay minerals that can induce formation of large desiccation cracks. As such, we suggest that the cracking patterns are indicative of the presence of smectite phyllosilicates even in the absence of spectral confirmation. Our results suggest that many chloride-bearing terrains have a lacustrine origin and a geologic setting similar to playas on Earth. Such locations would have contained ephemeral lakes that may have undergone repeated cycles of desiccation and recharging by a near-surface fluctuating water table in order to account for the salt-phyllosilicates associations. These results have notable implications for the ancient hydrology of Mars. We propose that the morphologies and sizes of the polygonal cracks can be used as paleoenvironmental, as well as lithological, indicators that could be helpful in planning future missions.

  19. Septic tanks as larval habitats for the mosquitoes Aedes aegypti and Culex quinquefasciatus in Playa-Playita, Puerto Rico.

    PubMed

    Burke, R; Barrera, R; Lewis, M; Kluchinsky, T; Claborn, D

    2010-06-01

    Adult Aedes aegypti (Linnaeus) (Diptera: Culicidae) were previously recovered from emergence traps on septic tanks in southeastern Puerto Rico. In this study we quantified immature mosquito abundance and its relationship with structural variables of the septic tanks and chemical properties of the water containing raw sewage. A miniaturized floating funnel trap was used to sample 89 septic tanks for larvae in the Puerto Rican community of Playa-Playita. Aedes aegypti larvae were recovered from 18% of the sampled tanks (10.3 larvae per septic tank per day). Larval presence was positively associated with cracking of the septic tank walls and uncovered access ports. Larval abundance was positively associated with cracking of the septic tank walls and larger tank surface areas, and inversely associated with the total dissolved solids (TDS). Culex quinquefasciatus (Say) larvae were also recovered from 74% of the septic tanks (129.6 larvae per septic tank per day). Larval presence was negatively associated with TDS in the water and larval abundance was positively associated with cracking of the septic tank walls. A screened, plastic emergence trap was used to sample 93 septic tanks within the community for Ae. aegypti and Cx. quinquefasciatus adults. Aedes aegypti adults were recovered from 49% of the sampled tanks (8.7 adults per septic tank per day) and Cx. quinquefasciatus adults were recovered from 97% of the sampled tanks (155.5 adults per septic tank per day). Aedes aegypti adult presence was positively associated with cracking, uncapped openings and septic water pH. The Ae. aegypti adult counts were positively associated with cracking and inversely associated with TDS and conductivity. This study marks the first published record of the recovery of Ae. aegypti larvae from holding tanks containing raw sewage in the Caribbean region. Our study indicates that Ae. aegypti larvae are present in sewage water and that septic tanks have at least the potential to maintain

  20. Diagenesis of Paleozoic playa-lake and ephemeral-stream deposits from the Pimenta Bueno Formation, Siluro-Devonian (?) of the Parecis Basin, central Brazil

    NASA Astrophysics Data System (ADS)

    Goldberg, K.; Morad, S.; Al-Aasm, I. S.; De Ros, L. F.

    2011-07-01

    The Parecis Basin is a large intracratonic rift located in central Brazil and filled with Paleozoic carbonate, evaporite and siliciclastic sediments. The occurrence of gas seeps has recently attracted significant exploration interest by the Brazilian petroleum agency and by Petrobras. The continuously cored PB-01-RO well provided the first opportunity to study the depositional environments, diagenetic evolution and hydrocarbon potential of the largely unknown sedimentary successions of the Parecis Basin. The cored lithologies, belonging to the Siluro-Devonian (?) Pimenta Bueno Formation, are interpreted as deposited in playa-lake and ephemeral-stream environments. The deposits display a strong facies control on the diagenetic mineral assemblages and evolution. Diagenetic minerals in the ephemeral-stream deposits include eogenetic hematite and smectitic clay coats and quartz cement, and the mesogenetic process includes precipitation of sulfates (anhydrite and barite) and carbonates (calcite, dolomite and kutnahorite-ankerite-huntite), followed by partial dissolution of these carbonates and sulfates, and of feldspar grains. Telogenetic processes include the precipitation of hematite and kaolinite within secondary pores, and the replacement of anhydrite by gypsum. A second burial phase and mesodiagenesis is indicated by the precipitation of discrete K-feldspar crystals within moldic pores after dissolved feldspars, and by the illitization of etched, telogenetic kaolinite. The playa-lake deposits show early diagenetic dolomitization of lime mud, precipitation of anhydrite nodules and extensive silicification. The anhydrite nodules were replaced by gypsum and chalcedony during telodiagenesis. Potential source rocks are locally represented by organic shales. The fluvial sandstones show fair reservoir quality and limited compaction, as indicated by their intergranular volume, suggesting that the succession has undergone moderate burial. Potential seals for hydrocarbon

  1. Spatial and temporal variability in atmospheric CO2 and CH4 at Railroad Valley playa, a mid-latitude desert site

    NASA Astrophysics Data System (ADS)

    Yates, E. L.; Schiro, K. A.; Sheffner, E. J.; Iraci, L. T.; Bebout, B.; Berthold, R.; Bruegge, C. J.; Bui, T.; DeMarines, J.; Detweiler, A. M.; Fladeland, M.; Kelley, C. A.; Kolyer, R.; Loewenstein, M.; McKay, C.; Tadic, J.

    2011-12-01

    Carbon dynamics of desert and semi arid ecosystems, which occupy 30% to 45% of the Earth's terrestrial surface, is poorly understood and understudied. However, these regions are of particular interest due to increasing desertification, as a result of climate and land-use change, and due to recent reports which indicate net CO2 uptake by deserts suggesting deserts may play a larger role in modulating atmospheric CO2 levels than previously thought. In an effort to address these issues we conducted a study at Railroad Valley playa, Nevada, USA during June 2011. The playa is a flat, dry lakebed with virtually no vegetation, approximately 15 km x 15 km in size, 1434 m in elevation and 110 km southwest of the nearest city (Ely, Nevada). Surface and airborne CO2 and CH4 observations were made from the playa and from the SIERRA Unmanned Aircraft System (UAS) to assess temporal and spatial variability at the ground and low altitudes. Measurements of soil parameters (temperature and humidity) and determination of soil microbial activity by soil gas analysis (CH4 concentrations and isotopic content) and incubation of soil samples were also carried out. This study focuses on exploring the following questions: 1) What is the magnitude and temporal variability of atmospheric CO2 and CH4 in the surface boundary layer? 2) What is the spatial variability of atmospheric CO2 and CH4 within the boundary layer? 3) What is the relationship between the physical environment of the soil and atmospheric observations of CO2 and CH4?

  2. Geohydrology and evapotranspiration at Franklin Lake playa, Inyo County, California; with a section on estimating evapotranspiration using the energy-budget eddy-correlation technique

    USGS Publications Warehouse

    Czarnecki, John B.; Stannard, David I.

    1997-01-01

    Franklin Lake playa is one of the principal discharge areas of the ground-water-flow system associated with Yucca Mountain, Nevada, the potential site of a high-level nuclear-waste repository. By using the energy-budget eddy-correlation technique, measurements made between June 1983 and April 1984 to estimate evapotranspiration were found to range from 0.1 centimeter per day during winter months to about 0.3 centimeter per day during summer months; the annual average was 0.16 centimeter per day. These estimates were compared with evapotranspiration estimates calculated from six other methods.

  3. Simulation of the long term radiometric responses of the Terra MODIS and EO-1 ALI using Hyperion spectral responses over Railroad Valley Playa in Nevada (RVPN)

    NASA Astrophysics Data System (ADS)

    Choi, Taeyoung; Xiong, Xiaoxiong J.; Angal, Amit; Chander, Gyanesh

    2010-10-01

    The Earth Observing-1 (EO-1) Hyperion instrument provides 220 spectral bands with wavelengths between 400 and 2500 nm at 30 m spatial resolution, which covers a 7.5 km by 100 km area on the ground. The EO-1 spacecraft has another multispectral sensor called the Advanced Land Imager (ALI), which has 10 spectral bands with wavelengths between 400 and 2350 nm at 30 m spatial resolution. The Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard the Terra spacecraft was launched in Dec., 1999, and flies approximately 30 minutes behind EO-1. Nearsimultaneous observations from Terra MODIS, EO-1 ALI and Hyperion over a well characterized Railroad Valley Playa in Nevada (RVPN) target are chosen for this study. A uniform region of interest (ROI) within the playa within latitudes and longitudes of 38.48 and -115.71 to 38.53 and -115.66 was chosen for this analysis. A representation of the ground spectra during every near-simultaneous acquisition of MODIS and ALI is obtained using EO-1 Hyperion data. Using the EO-1 Hyperion derived top-of-atmosphere (TOA) reflectance profile along with the ALI and MODIS relative spectral responses (RSR), simulated reflectance for the matching band pairs is calculated. The Hyperion simulated TOA reflectance results are compared to the measured TOA reflectance trends of ALI and MODIS. The long-term measured versus simulated reflectance results are used to examine the relationships and calibration differences between the ALI and MODIS sensors.

  4. The microbiological activity and toxicity of oil-polluted playa solonchaks and filled grounds within the Severnye Buzachi Oil Field (Kazakhstan)

    NASA Astrophysics Data System (ADS)

    Tynybaeva, T. G.; Kostina, N. V.; Terekhov, A. M.; Kurakov, A. V.

    2008-10-01

    The number of colony-forming units of microorganisms, the viable biomass, and also the intensity of the microbiological processes (respiration, nitrogen fixation, denitrification, and cellulose decomposition) in playa solonchaks and sandy-loamy filled grounds in the territory of the Severnye Buzachi Oilfields (Kazakhstan) were much lower than in other soil types attesting to the limited capability of these substrates for selfpurification. Upon pollution by oil at concentrations of 100 600 mg/kg, the number of copiotrophic bacteria increased, whereas the actinomycetal and fungal populations were reduced and the biomass pool, the rates of CO2 emission, the potential nitrogen fixation, and denitrification became higher. The microbial communities of the playa solonchaks were weakly active and consumed few applied substrates. The biotesting with Artemia salina L. showed that some areas belonged to the lands of the 4th danger class, although the majority of the soil and substrate samples were not toxic. The germination of Lepidium sativum L. seeds was suppressed because of the salt toxicity, which is not related to the oil concentration (30 to 600 mg/kg).

  5. The application of remotely sensed data to pedologic and geomorphic mapping on alluvial fan and playa surfaces in Saline Valley, California

    NASA Technical Reports Server (NTRS)

    Miller, D. A.; Petersen, G. W.; Kahle, A. B.

    1986-01-01

    Arid and semiarid regions yield excellent opportunities for the study of pedologic and geomorphic processes. The dominance of rock and soil exposure over vegetation not only provides the ground observer with observational possibilities but also affords good opportunities for measurement by aircraft and satellite remote sensor devices. Previous studies conducted in the area of pedologic and geomorphic mapping in arid regions with remotely sensed data have utilized information obtained in the visible to near-infrared portion of the spectrum. Thermal Infrared Multispectral Scanner (TIMS) and Thematic Mapping (TM) data collected in 1984 are being used in comjunction with maps compiled during a Bureau of Land Management (BLM) soil survey to aid in a detailed mapping of alluvial fan and playa surfaces within the valley. The results from this study may yield valuable information concerning the application of thermal data and thermal/visible data combinations to the problem of dating pedologic and geomorphic features in arid regions.

  6. Quaternary enhancement of westerly jet and central Asian aridification: carbonate and salt fluid inclusion isotope records from deep drilling in the Qaidam salt playa, NE Tibet

    NASA Astrophysics Data System (ADS)

    Xi, X.; Han, W.; Fang, X.

    2014-12-01

    The vast Asian arid inland under the westerlies exerts great impacts on global climatic change. However, its evolution history and its relation with the westerlies, Tibet uplift and global change are still unknown. Here we present high quality carbonate and salt fluid inclusion isotope records from a near thousand meter deep drilling core in the Qaidam salt playa, NW China. They reveal an evident long-term persistent aridification of Asian inland since ca. 1.2 Ma, followed by an accelerated drying since ca. 0.6 Ma. We propose that the rapid uplift of the Tibetan Plateau in the mid-Pleistocene (called Yellow River Movement) might have contributed to the desiccation of the Asian inland through enhancing and bending the westerly jet and its associated ascending flow and blocking the moisture input from the westerlies and monsoons.

  7. Multisensor and multiscale survey and characterization for radiometric spatial uniformity and temporal stability of Railroad Valley Playa (Nevada) test site used for optical sensor calibration

    NASA Astrophysics Data System (ADS)

    Bannari, Abdou A.; Omari, K.; Teillet, Phillipe M.; Fedosejevs, Gunar

    2004-02-01

    In this study, we analyzed for the first time the potential of Getis statistics compared to the coefficient of variation for the study of the radiometric spatial uniformity and temporal stability of the Railroad Valley Playa, Nevada (RVPN) test site. We evaluated multi-sensor and multi-scale image data acquired for the RVPN, including four SPOT HRV images acquired in 1997 and 1998, five NOAA AVHRR images acquired in 1999, and one Landsat TM image acquired in 1998. The results show the potential and the importance of the synergy generated by these two methods for analyzing the radiometric spatial uniformity and temporal stability of the RVPN site. Getis statistics provide an excellent spatial analysis of the site while the coefficient of variation provides complementary information on the temporal evolution of the site.

  8. Morphological and chemical properties of the meadow-semidesert soil complexes of the Khaki playa (the Caspian Lowland) and the influence of the biogenic factor on them

    NASA Astrophysics Data System (ADS)

    Shabanova, N. P.; Lebedeva-Verba, M. P.; Bykov, A. V.

    2010-03-01

    The initial stage of the development of the complex soil cover pattern in the Caspian Lowland was studied. The obtained data made it possible to reveal the specific features of the morphological and chemical properties of the soils on terraces of the Khaki playa and the role of burrowing animals in the formation of the microtopography and complex soil cover patterns on the youngest surfaces. The soil cover of the studied area consists of three-component complexes: light-humus quasi-gley solonetzes on relatively flat background surfaces, zooturbated solonetzes on microhighs, and humus quasi-gley soils in microlows. The layered deposits of the Khaki playa terraces and the shallow depth of the saline groundwater are responsible for the specificity of the modern salinization of the studied solonetzes. The distribution of the salts in their profiles has a sawshaped patter, which is related to the nonuniform texture of the deposits. On the microhighs composed of the earth extracted from 5- to 7-year-old suslik burrows, specific zooturbated solonetzes are formed. The known age of these formations makes it possible to determine the rate of the desalinization of the gypsum- and salt-bearing material extracted onto the soil surface and the rate of the salt accumulation in the lower part of the solonetzic horizon and in the subsolonetzic horizons in comparison with the data on the solonetzes of the background flat surfaces. The specific features of the soils in the closed microlows suggest that these soils have a polygenetic origin. The features of the recent hydromorphism predetermine the specificity of their morphology.

  9. Two year (2011-2012) observations of atmospheric CO2 and CH4 and comparison with GOSAT measurements at Railroad Valley playa, Nevada

    NASA Astrophysics Data System (ADS)

    Tadic, J.; Loewenstein, M.; Frankenberg, C.; Iraci, L. T.; Gore, W.; Yates, E. L.

    2012-12-01

    Measurements of carbon dioxide (CO2) and methane (CH4) play an important role in understanding the global carbon cycle and its contribution to global warming. In recent years methane (CH4) has received increasing attention as the second most important anthropogenic greenhouse gas because of the high uncertainty of its sources and sinks. Aircraft measurements of greenhouse gases are essential for observations in the free troposphere and lower stratosphere to better understand changes at regional and continental scales. Mixing ratios of methane and carbon dioxide were measured from 27000 ft down to the surface on 22 - 26th of June, 2011 and 25th of June - 2nd of July, 2012, to create vertical profiles of CO2 and CH4 over a playa in Railroad Valley, Nevada, USA. The playa is a flat, dry lakebed with virtually no vegetation, approximately 15 km x 15 km in size, 1434 m in elevation and 110 km southwest of the nearest city (Ely, Nevada). The time and location of flights were selected to coincide with the overpass of Greenhouse Gases Observing Satellite (GOSAT). Airborne (Alpha Jet) in-situ measurements of CO2 and CH4 were collected to support the vicarious calibration experiment to validate column-averaged dry air mole fractions of CO2 and CH4 (XCO2 and XCH4) retrieved from the GOSAT. The in-situ profiles were collected simultaneously with remote measurements in the same regions of atmosphere. Our results reflected the global trend in CO2 concentration measured worldwide, and corresponded well with the values measured by GOSAT.

  10. Soil-Gas Identification of Environmental Factors Affecting CO2 Concentrations Beneath a Playa Wetland: Implications for Soil-Gas Monitoring at Carbon Storage Sites

    NASA Astrophysics Data System (ADS)

    Romanak, K.; Bennett, P.

    2009-12-01

    Strategies for identifying and interpreting the effects of environmental factors on near-surface CO2 concentrations are essential to developing accurate monitoring protocols at carbon storage sites. Based on the results of a three-year study of a natural analogue we present, 1) a method for using soil-gas to identify near-surface CO2 cycling, and 2) a framework for developing monitoring protocols and site evaluation for near-surface monitoring. Near-surface CO2 production, consumption, and re-distribution was observed in the vadose-zone of a highly CO2-reactive playa wetland in the Texas High Plains. Atmospheric conditions, organic and inorganic soil carbon, subsurface pressure, water flux, and surface and groundwater chemistry were compared to real-time background measurements of CO2, CH4, O2+Ar, and N2 from depths up to 45 feet. Carbon isotopes and spatially and temporally variable concentrations of CO2 ≤ 17%, CH4 ≤ 2%, and O2 from 21-0% indicate CO2 and CH4 are produced by microbes. Molar gas ratios of O2 and CO2 distinguish between oxidation of organic matter (CH2O + O2 → CO2 + H2O), CH4 oxidation (CH4 + 2O2 → CO2 + 2H2O), and potentially acetate fermentation (CH3COOH → CH4 + CO2). O2 consumption and distribution is regulated by water flux that supplies dissolved organics to microbes at depth and regulates oxygen supply by blocking vertical permeability and atmospheric gas exchange. A surface flux experiment indicates that when playa floors are dry, subsurface wetting fronts from rain events or previous ponding periods block vertical permeability resulting in surface flux measurements that do not represent subsurface conditions. Samples with CO2+O2 < 21% and N2 > 78% identify dissolution of CO2 and carbonate minerals into recharging groundwater resulting in loss of pore pressure and chemically-induced advection of atmosphere into pores. Inverse geochemical reaction modeling (PHREEQC) of playa surface water and perched groundwater in high PCO2 zones

  11. Development of a new platform for airborne measurements of atmospheric CO2 and CH4 and comparison with GOSAT measurements at Railroad Valley playa, Nevada

    NASA Astrophysics Data System (ADS)

    Tadic, J.; Loewenstein, M.; Iraci, L. T.; Gore, W.; Schiro, K. A.; Olson, R. A.; Sheffner, E. J.; Yates, E. L.

    2011-12-01

    Measurements of carbon dioxide (CO2) play an important role in understanding the global carbon cycle and its contribution to global warming. In recent years methane (CH4) has received increasing attention as the second most important anthropogenic greenhouse gas because of the high uncertainty of its sources and sinks. Aircraft measurements of greenhouse gases are essential for observations in the free troposphere and lower stratosphere to better understand changes at regional and continental scales. Recently new types of high-accuracy analyzers based on cavity-ring down spectroscopy have become available for use on aircraft. One of them, Picarro 2301-m, was remodeled and adapted for use outside the cabin of an Alpha Jet. In this unique attempt, the instrument was redesigned from a single unit to multiple units that fit inside the Alpha jet wing pod, with special emphasis on internal thermal management. After remodeling, the platform was tested in a laboratory, in a chamber with variable pressure and temperature, and in the field. This newly developed platform exhibits several important characteristics: the modular structure of the platform allows usage of other instruments simultaneously, the platform is capable of measuring both vertical and horizontal profiles of CO2 and CH4, and it is very insensitive to flight maneuvers. The new platform was used on 22-26th of June, 2011, to create spatial and temporal profiles of CO2 and CH4 over a playa in Railroad Valley, Nevada, USA. The playa is a flat, dry lakebed with virtually no vegetation, approximately 15 km x 15 km in size, 1434 m in elevation and 110 km southwest of the nearest city (Ely, Nevada). The time and location of flights were selected to coincide with the overpass of Greenhouse Gases Observing Satellite (GOSAT). Airborne (Alpha Jet) in-situ measurements of CO2 and CH4 were collected to support the vicarious calibration experiment to validate column-averaged dry air mole fractions of CO2 and CH4 (XCO2 and

  12. First Observation of Rock Motion on Racetrack Playa, Death Valley National Park—Role of a Persistent Pool, Sun, Zephyrs, Windowpane Ice, and Tugboats

    NASA Astrophysics Data System (ADS)

    Norris, R. D.; Norris, J. M.

    2014-12-01

    Trails in the mud-cracked surface of Racetrack Playa have been scored by hundreds of rocks up to 320 kg, but the mechanism of movement is debated. In Winter 2013-2014, we observed rocks in motion associated with a transient pool formed by winter precipitation. The pond was 7 cm deep on the southern edge of the playa, tapering to a mud flat to the north. Freezing during cold winter nights formed floating "windowpane" ice 3-5 mm thick. Rocks repeatedly moved on sunny days under light winds of 3-5 m/second, as the ice broke up near midday and was set into motion by wind stress on melt pools and the ice surface. Ice panels shoved rocks along the mud like a tugboat, sometimes forming moving imbricated ice piles upstream of the rocks and in other cases moving faster than the rocks and forming brash-filled leads downstream. GPS units mounted in experimental rocks recorded a creeping pace of 2-6 m/minute, a speed that made it difficult to observe trail formation visually. The 2013-2014 pond formed on November 20-24 and persisted through early February 2014. During this time rocks were observed moving at least five times, and studies of "stiz marks" formed by rocks at the ends of trail segments show that there were likely 3-5 additional move events. Observed travel times ranged from a few seconds to 16 minutes. In one event, two experimental rocks 153 m apart began moving simultaneously and traveled 64.1 and 65.6 m respectively, ultimately moving 157-162 m in subsequent events. Rock motion depends on the creation of winter pools sufficiently deep to allow the formation of floating ice and exposed to the light winds and sun needed for ice breakup. The combination of these events is extremely rare, leading to highly episodic trail formation. Our observations differ from previous hypotheses in that the rocks were moved by thinner ice, at slower speeds, and by lighter winds than predicted.

  13. Application of GIS and remote sensing methods to the paleohydrography of the Paso del Norte region

    NASA Astrophysics Data System (ADS)

    Kennedy, John F.

    The purpose of this project is to use geographic information system (GIS) and remote sensing methods to investigate the paleohydrology of the Paso del Norte region during the latest pluvial event. During the research I gathered the best available geologic and hydrographic data sets and integrated these data within a GIS in order to create a digital paleohydrologic database for the region. In particular, I used the GIS to reconstruct the hydrography (i.e. streams, lakes, and watershed boundaries) that existed as a results of increased precipitation and a decrease in temperature in the recent geologic past. The existence of the pluvial lakes had an impact on ground-water and surface-water flow systems in this region. The results of my research are presented as two papers ready for peer-review publication submission and a third paper that is a previously published work. (1) Using GIS and Remote Sensing to Reconstruct Late Quaternary and Early Holocene Paleo-Hydrography Using Climate Data and Modern Topography---an Example from the Southwestern US. This paper describes the methods used to create a paleo-hydrography system for the Paso del Norte region, and the development of a water-balance equation that estimates the inputs and outputs of this system. (2) Estimating Water-Balance Equation for Playas in the Tularosa Basin of Southern New Mexico. This paper describes the calibration and testing of the GIS model presented in the first paper. Before it can be applied to paleohydrologic systems, it must be shown to reasonably approximate playa systems in the region under current conditions. Water balances were calculated for several playas and their associated drainages. (3) The Hydrogeologic Framework of Basin-Fill Aquifers and Associated Ground-water flow Systems in Southwestern New Mexico---An Overview. The paper is an overview of work done by many hydrogeologists in the Paso del Norte region; however, the primary source of most of our current knowledge is based on the

  14. [Chemical and nutritional composition in the marine snail Strombus gracilior (Mesogastropoda: Strombidae) of various sizes and sexes in Playa Panamá, Costa Rica].

    PubMed

    Jiménez-Arce, G

    1993-12-01

    74 individuals of "cambute" (Strombus gracilior), were collected in Playa Panamá (10 degrees 35' 45"N, 85 degrees 40' 09" W), Costa Rica. The sex ratio was 1:1 and the size range 70-80mm (total length). The yield was 80% of edible meat. The average values of the macroconstituents to both sizes were: water 72.6% males and 70.9% females; 19.09g% protein in males and 26.89g% in females; carbohydrates 1.85g% males and 1.35g% females; 0.44g% crude fiber both males and females; within ashes there wre variations (2.30-3.71g%) among size and sex. Fat reached a maximum value of 0.94 and 0.91g% (length 80mm) for males and females respectively. In minerals, maximum values for the Na and K of 1440.88 and 1898.33 micrograms/g respectively were obtained for 80mm males; females of the same size showed values of 1376.97 micrograms/g for the Na and of 2393.09 micrograms/g for K; the other minerals (Cu, Mg, Fe) had lower values in relation to the above but the normal according to the literature. PMID:7701073

  15. Physical, chemical, and mineralogical data from surficial deposits, groundwater levels, and water composition in the area of Franklin Lake playa and Ash Meadows, California and Nevada

    USGS Publications Warehouse

    Goldstein, Harland L.; Breit, George N.; Yount, James C.; Reynolds, Richard L.; Reheis, Marith C.; Skipp, Gary L.; Fisher, Eric M.; Lamothe, Paul J.

    2011-01-01

    This report presents data and describes the methods used to determine the physical attributes, as well as the chemical and mineralogical composition of surficial deposits; groundwater levels; and water composition in the area of Franklin Lake playa and Ash Meadows, California and Nevada. The results support studies that examine (1) the interaction between groundwater and the ground surface, and the transport of solutes through the unsaturated zone; (2) the potential for the accumulation of metals and metalloids in surface crusts; (3) emission of dust from metal-rich salt crust; and (4) the effects of metal-rich dusts on human and ecosystem health. The evaporation of shallow (<3 to 4 m) groundwater in saline, arid environments commonly results in the accumulation of salt in the subsurface and (or) the formation of salt crusts at the ground surface. Ground-surface characteristics such as hardness, electrical conductivity, and mineralogy depend on the types and forms of these salt crusts. In the study area, salt crusts range from hard and bedded to soft and loose (Reynolds and others, 2009). Depending on various factors such as the depth and composition of groundwater and sediment characteristics of the unsaturated zone, salt crusts may accumulate relatively high contents of trace elements. Soft, loose salt crusts are highly vulnerable to wind erosion and transport. These vulnerable crusts, which may contain high contents of potentially toxic trace elements, can travel as atmospheric dust and affect human and ecosystem health at local to regional scales.

  16. Use RUSLE2 model to assess the impact of soil erosion on playa inundation and hydrophyte conditions in the Rainwater Basin, Nebraska.

    PubMed

    Tang, Zhenghong; Gu, Yue; Jiang, Weiguo; Xue, Yuan; Bishop, Andy; LaGrange, Ted; Nugent, Eleanor

    2016-06-01

    Playas in the Rainwater Basin region in Nebraska are globally important wetlands that are continuously threatened by culturally accelerated sedimentation. Using annual habitat survey data and wetland vegetation inventories, inundation and hydrophyte community distributions were evaluated for properties under different types of conservation status. Annual soil erosion rates from surrounding watersheds were calculated to estimate sediment accumulated rates using the Revised Universal Soil Loss Equation 2 (RUSLE2). The slope-length component of the RUSLE2 was derived from 2009 light detection and ranging (LiDAR) data after the methods described by Van Remortel (Computers & Geosciences 30:1043-1053, 2004). Wetlands enrolled in conservation programs were inundated more and were dominated to a greater degree by hydrophytes than wetlands not enrolled in these programs. The mean estimated soil erosion rate at the Rainwater Basin landscape level was 4.67 tons/ha/year, and the mean estimated sediment accumulation depth for public watersheds was estimated as 0.19 cm/year. Without appropriate conservation actions, the current inundated acres and wetland acres growing hydrophytes would be further reduced by sediment accumulation. The results illustrated the importance of conservation programs to protect wetlands. PMID:27138004

  17. Avian cholera in waterfowl: the role of lesser snow and Ross's geese as carriers of avian cholera in the Playa Lakes region

    USGS Publications Warehouse

    Samuel, M.D.; Shadduck, D.J.; Goldberg, D.R.; Johnson, W.P.

    2005-01-01

    We collected samples from apparently healthy geese in the Playa Lakes Region (USA) during the winters of 2000a??01 and 2001a??02 to determine whether carriers of Pasteurella multocida, the bacterium that causes avian cholera, were present in wild populations. With the use of methods developed in laboratory challenge trials (Samuel et al., 2003a) and a serotype-specific polymerase chain reaction method for identification of P. multocida serotype 1, we found that a small proportion of 322 wild birds (<5%) were carriers of pathogenic P. multocida. On the basis of serology, an additional group of these birds (<10%) were survivors of recent avian cholera infection. Our results confirm the hypothesis that wild waterfowl are carriers of avian cholera and add support for the hypothesis that wild birds are a reservoir for this disease. In concert with other research, this work indicates that enzootic infection with avian cholera occurs in lesser snow goose (Chen caerulescens caerulescens) populations throughout their annual cycle. Although fewer Rossa??s geese (Chen rossii) were sampled, we also found these birds were carriers of P. multocida. Even in the absence of disease outbreaks, serologic evidence indicates that chronic disease transmission and recent infection are apparently occurring year-round in these highly gregarious birds and that a small portion of these populations are potential carriers with active infection.

  18. Braidplain, floodplain and playa lake, alluvial-fan, aeolian and palaeosol facies composing a diversified lithogenetical sequence in the permian and triassic of South Devon (England)

    NASA Astrophysics Data System (ADS)

    Mader, Detlef

    The Permian and Triassic of South Devon (England) are a continental red bed sequence of very diversified lithogenetical composition. Within the thick series, the distribution of the main depositional environments being fluvial braidplain, fluvial floodplain and playa lake, alluvial fan, aeolian dune and calcrete palaeosol changes repeatedly in both horizontal and vertical direction. Significant sedimentary milieus such as aeolian dunes and calcrete palaeosols occur repeatedly within the succession, but are also lacking in several parts of the sequence. Fluvial braidplain deposits comprise conglomerates, sandstones, intraformational reworking horizons and mudstones and originate in channels and overbank plains of a braided river system. Conglomerates and sandstones are formed by migration of bars and spreading out of sheets during infilling of streams and aggradation of flats. Gravel is often enriched as lag pockets or veneers within steeper scour holes and kolk pots or on the plane floor of the watercourse. Finer-grained sandstones and mudstones are laid down by suspension settling in stagnant water bodies such as small lakes in the overbank area and residual pools in interbar depressions during low-stage or waning-flow in active channels or in abandoned streams. Spectacular bioturbation features in some sandstones with both horizontal tubes and vertical burrows testify to the colonization of the sediments at the bottom of the rivers with declining discharge and transport capacity. Intraformational reworking horizons with ghost-like remnants of degraded sandstones, mudstones and pedogenic carbonates document partially severe condensation of the sequence by removal of some facies elements from the depositional record. The occasionally occurring gravel-bearing mudstones or silty-clayey sandstones represent products of high-energy water surges overspilling the channel banks and transporting sandy and gravelly bed-load in limited amounts beyond the levee wall. The

  19. The balance between deposition and subsidence (tectonics) in a rift basin playa and its effect on the climatic record of an area: Evidence from Bristol Dry Lake, California

    SciTech Connect

    Rosen, M.R. )

    1991-03-01

    Two continuous core intervals drilled in Bristol Dry Lake, a large (150 km{sup 2}) playa in the central Mojave Desert of California, penetrated over 500 m of sediment and did not reach basement. The repetitious nature of the alternating shallow brine pond halite and siliciclastic and the consistency of the carbonate isotopic data from the surface and core indicate a relatively stable brine composition for most of the history of Bristol Dry Lake. All sedimentary structures and primary halite fabrics in the core indicate shallow-water, brine-pond halite alternated with halite-saturated siliciclastic muds in the basin center. A delicate balance of subsidence and mechanical and chemical deposition of evaporite and siliciclastic minerals was necessary to maintain the largely ephemeral lake environment of deposition through over 550 m of basin fill. The alternating brine pond/saline lake setting in Bristol Dry Lake is not directly related to climatic influences, and the sediments do not record major climatic events demonstrated in other closed-basin lakes. The reason for this insensitivity to climatic events is explained by the interior location of the basin, the low relief of the mountains surrounding the catchment, the large surface area of the catchment, and the low average sedimentation rates. All of the above criteria are at least partially controlled by the tectonics of the area, which, in turn, affect the sedimentation rate and supply water to the basin. Therefore, it is important to consider the influence of the above factors in determining global versus local, or regional, climate curves for a particular basin.

  20. End-Pleistocene to Holocene paleoenvironmental record from piston corer samples and the challenge of stratigraphic correlation of playa sediment data with a connected alluvial apron from Damghan Basin, Iran

    NASA Astrophysics Data System (ADS)

    Büdel, Christian; Hoelzmann, Philipp; Wennrich, Volker; Majid Padashi, Sajed; Baumhauer, Roland

    2015-04-01

    The study yields a first characterization and correlation of the end-Pleistocene to Holocene sediment archive of playa and playa lake deposits in the Damghan Basin, northern Iran. The Basin sediments are deposited since Mio- and Pliocene, which is valid for the connected alluvial fans, too. These are covering the area between the playa and mountains and while prograding from the mountain ranges they deliver gravels and fine-sediments to the basins sink. The processes on the studied alluvial apron are described and dated already and can be explained in seven morphodynamic phases, which are linked to a general lake level high-stand in north-east Iran at about 8000-9000 years ago. If and how these phases are passed on from the alluvial record down to the playa sediment record is aim of this study. Today the salt pans margins are highly affected by salt tectonic drifting and access was suboptimal. Only here drilling could be performed through about 280 centimeters of salt-crust unfrequently intercalated with loamy layers. For yielding undisturbed playa sediment records sampling was performed with inliner-tubes deployed in a piston corer (Kullenberg type). Thus at two different drilling sites in summation seven cores could be taken, down to a maximum depth of 129 cm and 1000 cm. Back in Germany the cores had been opened and initially described, photographed and optically scanned with a core logger. Regarding future studies, the aim was a best possible comprehensive documentation of the cores. Therefore basically grainsize measurements (laser diffraction), multi element analyses (XRF, ICP-OES, titrimetry) and mineralogical measurements (XRD) had been deployed on samples taken from every single previously identified layer. Continuous elemental data was secured by use of a XRF-scanning core logger. The sedimentological description together with laboratory element analyses shows saline conditions in the first three meters coincide with general coarser grain sizes. The next

  1. Linking playa surface dust emission potential to feedbacks between surface moisture and salt crust expansion through high resolution terrestrial laser scanning measurements

    NASA Astrophysics Data System (ADS)

    Nield, J. M.; King, J.; Wiggs, G.

    2012-12-01

    The dust emissivity of salt pans (or playas) can be significant but is controlled by interactions between wind erosivity, surface moisture, salt chemistry and crust morphology. These surface properties influence the aeolian transport threshold and can be highly variable over both short temporal and spatial scales. In the past, field studies have been hampered by practical difficulties in accurately measuring properties controlling sediment availability at the surface in high resolution. Studies typically therefore, have investigated large scale monthly or seasonal change using remote sensing and assume a homogeneous surface when predicting dust emissivity. Here we present the first high resolution measurements (sub-cm) of salt crust expansion related to changes in diurnal moisture over daily and weekly time periods using terrestrial laser scanning (TLS, ground-based LiDAR) on Sua Pan, Botswana. The TLS measures both elevation and relative surface moisture change simultaneously, without disturbing the surface. Measurement sequences enable the variability in aeolian sediment availability to be quantified along with temporal feedbacks associated with crust degradation. On crusts with well-developed polygon ridges (high aerodynamic and surface roughness), daily surface expansion was greater than 30mm. The greatest surface change occurred overnight on the upper, exposed sections of the ridges, particularly when surface temperatures dropping below 10°C. These areas also experienced the greatest moisture variation and became increasingly moist overnight in response to an increase in relative humidity. In contrast, during daylight hours, the ridge areas were drier than the lower lying inter-ridge areas. Positive feedbacks between surface topography and moisture reinforced the maximum diurnal moisture variation at ridge peaks, encouraging crust thrusting due to overnight salt hydration, further enhancing the surface, and therefore, aerodynamic roughness. These feedbacks

  2. Investigación del USGS sobre el ecosistema de arrecifes de coral en el Atlántico

    USGS Publications Warehouse

    Kuffner, Ilsa B.; Yates, Kimberly K.; Zawada, David G.; Richey, Julie N.; Kellogg, Christina A.; Toth, Lauren T.; Torres-Garcia, Legna M.

    2015-01-01

    Los arrecifes de coral son estructuras sólidas, biomineralizadas que protegen comunidades costeras actuando como barreras protectoras de peligros tales como los huracanes y los tsunamis. Estos proveen arena a las playas a través de procesos naturales de erosión, fomentan la industria del turismo, las actividades recreacionales y proveen hábitats pesqueros esenciales. La conti-nua degradación mundial de ecosistemas de arrecifes de coral está bien documentada. Existe la necesidad de enfoque y organización de la ciencia para entender los procesos complejos físicos y biológicos e interacciones que están afectando el estado de los arrecifes coralinos y su capacidad para responder a un entorno cambiante.

  3. Study on the Hymenoptera parasitoid associated with Lepidoptera larvae in reforestation and agrosilvopastoral systems at Fazenda Canchim (Embrapa Pecuária Sudeste) São Carlos, SP, Brazil.

    PubMed

    Pereira, A G; Silva, R B; Dias, M M; Penteado-Dias, A M

    2015-11-01

    The aim of this study was to characterize the local fauna of Hymenoptera parasitoids associated with Lepidoptera larvae in areas of reforestation and agrosilvopastoral systems at Fazenda Canchim (Embrapa Pecuária Sudeste, São Carlos, SP, Brazil). Lepidoptera larvae collected with entomological umbrella were kept in the laboratory until emergence of adults or their parasitoids. From those collected in the agrosilvopastoral system, emerged 267 specimens of hymenopteran parasitoids belonging to 16 genera: Braconidae, Agathidinae (Alabagrus), Braconinae (Bracon), Microgastrinae (Cotesia, Diolcogaster, Glyptapanteles, Pholetesor and Protapanteles), Orgilinae (Orgilus); Ichneumonidae, Campopleginae (Casinaria, Charops and Microcharops); Chalcididae, Chalcidinae (Brachymeria and Conura); Eulophidae, Entedoninae (Horismenus), Eulophinae (Elachertus and Euplectrus). From the Lepidoptera larvae collected in the reforestation, emerged 68 specimens of hymenopteran parasitoids, belonging to 8 genera: Chalcididae, Chalcidinae (Conura); Ichneumonidae, Pimplinae (Neotheronia), Campopleginae (Charops and Microcharops) and Braconidae, Microgastrinae (Apanteles, Diolcogaster, Distatrix, Glyptapanteles and Protapanteles). The results of this study suggest the occurrence of a wide variety of Hymenoptera parasitoids in the studied environments. PMID:26602340

  4. Cross-calibration of the Terra MODIS, Landsat 7 ETM+ and EO-1 ALI sensors using near-simultaneous surface observation over the Railroad Valley Playa, Nevada, test site

    USGS Publications Warehouse

    Chander, G.; Angal, A.; Choi, T.; Meyer, D.J.; Xiong, X.; Teillet, P.M.

    2007-01-01

    A cross-calibration methodology has been developed using coincident image pairs from the Terra Moderate Resolution Imaging Spectroradiometer (MODIS), the Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+) and the Earth Observing EO-1 Advanced Land Imager (ALI) to verify the absolute radiometric calibration accuracy of these sensors with respect to each other. To quantify the effects due to different spectral responses, the Relative Spectral Responses (RSR) of these sensors were studied and compared by developing a set of "figures-of-merit." Seven cloud-free scenes collected over the Railroad Valley Playa, Nevada (RVPN), test site were used to conduct the cross-calibration study. This cross-calibration approach was based on image statistics from near-simultaneous observations made by different satellite sensors. Homogeneous regions of interest (ROI) were selected in the image pairs, and the mean target statistics were converted to absolute units of at-sensor reflectance. Using these reflectances, a set of cross-calibration equations were developed giving a relative gain and bias between the sensor pair.

  5. Cross-calibration of the Terra MODIS, Landsat 7 ETM+ and EO-1 ALI sensors using near-simultaneous surface observation over the Railroad Valley Playa, Nevada, test site

    NASA Astrophysics Data System (ADS)

    Chander, Gyanesh; Angal, Amit; Choi, Taeyoung Jason; Meyer, David J.; Xiong, Xiaoxiong Jack; Teillet, Philippe M.

    2007-09-01

    A cross-calibration methodology has been developed using coincident image pairs from the Terra Moderate Resolution Imaging Spectroradiometer (MODIS), the Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+) and the Earth Observing EO-1 Advanced Land Imager (ALI) to verify the absolute radiometric calibration accuracy of these sensors with respect to each other. To quantify the effects due to different spectral responses, the Relative Spectral Responses (RSR) of these sensors were studied and compared by developing a set of "figures-of-merit." Seven cloud-free scenes collected over the Railroad Valley Playa, Nevada (RVPN), test site were used to conduct the cross-calibration study. This cross-calibration approach was based on image statistics from near-simultaneous observations made by different satellite sensors. Homogeneous regions of interest (ROI) were selected in the image pairs, and the mean target statistics were converted to absolute units of at-sensor reflectance. Using these reflectances, a set of cross-calibration equations were developed giving a relative gain and bias between the sensor pair.

  6. Preguntas y respuestas acerca del Estudio del

    Cancer.gov

    El Estudio del Tamoxifeno y Raloxifeno (STAR, por sus siglas en ingls) es un estudio clnico (un estudio de investigacin conducido con voluntarios) diseado para ver cómo el medicamento raloxifeno (Evista) se compara con el medicamento tamoxifeno (Nolvadex)

  7. Il problema del litio.

    NASA Astrophysics Data System (ADS)

    D'Antona, F.

    1995-03-01

    Contents: 1. Introduzione. 2. La nucleosintesi del Big Bang. 3. Il litio nelle stelle di popolazione II. 4. I modelli stellari standard. 5. Il litio negli ammassi aperti. 6. Meccanismi di distruzione "non standard". 7. I modelli non-standard applicati alla popolazione II. 8. L'evoluzione Galattica del litio. 9. Quali stelle producono litio? 10. Il litio come elemento chiave per dare un nome agli oggetti stellari più minuscoli. 11. Conclusioni.

  8. Espectroscopia del Cometa Halley

    NASA Astrophysics Data System (ADS)

    Naranjo, O.; Fuenmayor, F.; Ferrin, L.; Bulka, P.; Mendoza, C.

    1987-05-01

    Se reportan observaciones espectroscópicas del cometa Halley. Los espectros fueron tomados usando el espectrógrafo del telescopio reflector de 1 metro del Observatorio Nacional de Venezuela. Se utilizó óptica azul, con una red de difracción de 600 lineas/min, obteniéndose una dispersión de 74.2 A/mm y una resolución de 2.5 A, en el rango espectral de 3500 a 6500 A. Seis placas fueron tomadas con emulsión IIa-O y dos con IIa-D. Los tiempos de exposición fueron entre 10 y 150 minutos. El cometa se encontraba entre 0.70 y 1.04 UA del Sol, y entre 1.28 y 0.73 UA de la Tierra. Las emisiones más prominentes en el espectro, son las del CN, C2, y C3. Otras emisiones detectadas corresponden a CH, NH2 y Na. Los espectros muestran un fuerte continuo, indicando un contenido significativo de polvo. Se detectó mayor intensidad del contínuo, en la dirección anti solar, lo cual es evidencia de la cola de polvo.

  9. Nevado del Huila, Columbia

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Nevado del Huila Volcano in Colombia is actually a volcanic chain running north to south, capped by a glacier. With peaks ranging in height from 2,600 to 5,780 meters (8,530 to 18,960 feet), Nevado del Huila is a stratovolcano composed of alternating layers of hardened lava, solidified ash, and volcanic rocks. Its first recorded eruption occurred in the mid-sixteenth century. The long-dormant volcano erupted again in mid-April 2007. A few months before the eruption, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of Nevado del Huila, on February 23, 2007. In this image, the bright white area just east of the central summit is ice. Immediately west of the summit are bare rocks, appearing as blue-gray. West of those rocks, white reappears, but this patch of white results from clouds hovering in the nearby valley. In the east, the colors turn to brown (indicating bare rock) and bright green (indicating vegetation). ASTER photographed Nevado del Huila near the end of a long phase of quietude. On April 17, 2007, local authorities recorded seismic activity associated with rock fracturing on the volcano's central summit, according to the ReliefWeb Website. Activity intensified the following day with an eruption and mudflows, forcing thousands of nearby residents to evacuate. As the Associated Press reported, the eruption caused avalanches and floods that wiped away both houses and bridges. It marked the volcano's first recorded eruption since the Spanish colonized the area five centuries earlier. NASA image created by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

  10. Atlas del Genoma del Cáncer: Antecedentes

    Cancer.gov

    El Atlas del Genoma del Cáncer es una iniciativa de los Institutos Nacionales de la Salud (NIH) para crear mapas multidimensionales completos de los cambios genómicos clave en los tipos y subtipos principales de cáncer.

  11. Ácaros del mango

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Los ácaros constituyen un grupo abundante y diverso que ocupa diferentes hábitats en árboles frutales y la estructura y disposición del follaje y ramas del mango, contribuyen significativamente a que se presente gran diversidad de ácaros benéficos y dañinos asociados a esta especie frutal. En Colomb...

  12. Case Study: del Amo Bioventing

    EPA Science Inventory

    The attached presentation discusses the fundamentals of bioventing in the vadose zone. The basics of bioventing are presented. The experience to date with the del Amo Superfund Site is presented as a case study.

  13. Vacunas contra los virus del papiloma humano

    Cancer.gov

    Una hoja informativa acerca de las vacunas contra los virus del papiloma humano (VPH) para prevenir infecciones con ciertos tipos de VPH, los cuales son la causa principal del cáncer de cuello del útero o cérvix.

  14. DelPhi: a comprehensive suite for DelPhi software and associated resources

    PubMed Central

    2012-01-01

    Background Accurate modeling of electrostatic potential and corresponding energies becomes increasingly important for understanding properties of biological macromolecules and their complexes. However, this is not an easy task due to the irregular shape of biological entities and the presence of water and mobile ions. Results Here we report a comprehensive suite for the well-known Poisson-Boltzmann solver, DelPhi, enriched with additional features to facilitate DelPhi usage. The suite allows for easy download of both DelPhi executable files and source code along with a makefile for local installations. The users can obtain the DelPhi manual and parameter files required for the corresponding investigation. Non-experienced researchers can download examples containing all necessary data to carry out DelPhi runs on a set of selected examples illustrating various DelPhi features and demonstrating DelPhi’s accuracy against analytical solutions. Conclusions DelPhi suite offers not only the DelPhi executable and sources files, examples and parameter files, but also provides links to third party developed resources either utilizing DelPhi or providing plugins for DelPhi. In addition, the users and developers are offered a forum to share ideas, resolve issues, report bugs and seek help with respect to the DelPhi package. The resource is available free of charge for academic users from URL: http://compbio.clemson.edu/DelPhi.php. PMID:22583952

  15. Tierra del Fuego, Argentina, South America

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Mitre Peninsula is the easternmost tip of Tierra del Fuego, Argentina, (54.5S, 65.5W). Early winter snow can be seen on this south tip of the Andes Mountains. These same mountains continue underwater to Antarctica. The Strait of Magellan, separating the South American mainland from Tierra del Fuego is off the scene to the north and west, but the Strait of LeMaire, separating Tierra del Fuego from the Isla de los Estados can be seen.

  16. Dynamics of playa lakes in the Texas High Plains

    NASA Technical Reports Server (NTRS)

    Reeves, C. C., Jr. (Principal Investigator)

    1972-01-01

    The author has identified the following significant results. Regional viewing of ERTS-1 imagery around the test sites shows that storm paths can be accurately traced and a count made of the number of intermittent lake basins filled by the storm. Therefore, during wet years ERTS-type imagery can be used to conduct a reliable count of the tens of thousands of natural lake basins on the southern High Plains which contain water. This type of regional overview of water filled basins in the normally arid southern High Plains is illustrated by bands 6 and 7, ERTS E-1078-16524.

  17. Herbert Marcuse's Theory of Play--A Social Philosophical Perspective.

    ERIC Educational Resources Information Center

    Volkwien, Karin A. E.

    Sport has been widely discussed, by conservatives who argue that sport operates within the realm of freedom, and so lies outside the deterministic nexus of capitalist economics and policies, and leftists who argue that sport reproduces the repressive features of capitalism and serves as an ideological tool of the latter. The purpose of this study…

  18. Dynamics of playa lakes in the Texas High Plains

    NASA Technical Reports Server (NTRS)

    Reeves, C. C., Jr. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. ERTS-1 MSS imagery has been found useful for taking a regional wet census of the tens of thousands of lake basins on the Southern High Plains, Texas and New Mexico. Once the ground truth which has been correlated with the MSS imagery, is correlated with CCT data, and reliable computer classifications are determined, a lake census from CCT printouts will be possible. Correlation of satellite imagery products with water fluctuations and water budget is also underway.

  19. Líneas Vitales: Programas y servicios del NCI

    Cancer.gov

    Artículos y videos sobre los programas y servicios del Instituto Nacional del Cáncer de la serie educativa Líneas Vitales del NCI, la cual está dirigida especialmente a poblaciones multiculturales.

  20. Control del cáncer y salud mundial: noticia del Instituto Nacional del Cáncer (NCI)

    Cancer.gov

    En combinación con una reunión de alto nivel de las Naciones Unidas sobre enfermedades no transmisibles en países en vías de desarrollo, el doctor Harold Varmus, director del NCI, y el doctor Ted L. Trimble, del NCI, han publicado un comentario en Science

  1. Instantánea del melanoma

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el melanoma; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  2. Instantánea del linfoma

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el linfoma; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  3. Instantánea del mieloma

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el mieloma; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  4. Instantánea del sarcoma

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el sarcoma; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  5. Produccion Gaseosa del Cometa Halley: Erupciones Y Fotodisociacion del Radical OH

    NASA Astrophysics Data System (ADS)

    Silva, A. M.; Mirabel, I. F.

    1990-11-01

    RESUMEN:En este trabajo informamos la detecci6n de 20 erupciones en la li'nea de =18cm (1667MHz) del radical OH en el Cometa Halley.Las observaciones incluyen todos los monitoreos existentes y se extienden desde 120 dias antes del perihelio hasta 90 dias despues.Se detectan bruscos crecimientos en el flujo medido,hasta un factor 1O,seguidos por decaimientos lentos asociados con la fotodisociaci6n del OH. Se obtuvieron valores para el tiempo de vida fotoquimico del OH y del H2O basandose en el modelo desarrollado previamente por Silva(1988). Esos tiempos de vida estan de acuerdo con predicciones teoricas y con las observaciones en el Ultravioleta, y los resultados, los que son fuertemente dependientes de la velocidad heliocentrica del Coineta (variando hasta un factor 6), han sido calculados para varios rangos de velocidad entre +28 y -28 km/seg. Key wo'L :

  6. Gonadal dysgenesis in del (18p) syndrome

    SciTech Connect

    Telvi, L.; Ion, A.; Fouquet, F.

    1995-07-17

    We report on a girl with syndromal gonadal dysgenesis and a de novo del (18p). Genetic factors controlling gonadal development are located not only on the X chromosome, but also on autosomes. The present case suggests that one of these genes is situated on 18p. We conclude that patients with del (18p) syndrome should be evaluated for gonadal dysgenesis. 16 refs., 3 figs.

  7. Intertextual Sexual Politics: Illness and Desire in Enrique Gomez Carrillo's "Del amor", "del dolor y del vicio" and Aurora Caceres's "La rosa muerta"

    ERIC Educational Resources Information Center

    LaGreca, Nancy

    2012-01-01

    This study explores the intertextuality between Aurora Caceres's "La rosa muerta" (1914) and the novel "Del amor, del dolor y del vicio" (1898) by her ex-husband, Enrique Gomez Carrillo. Caceres strategically mentions Gomez Carrillo's novel in "La rosa muerta" to invite a reading of her work in dialogue with his. Both narratives follow the sexual…

  8. 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.

  9. Calidad de Imagen del Telescopio UNAM212

    NASA Astrophysics Data System (ADS)

    Cobos, F. J.; Teiada de Vargas, C.

    1987-05-01

    El telescopio UNAM2l2, del Observatorio Astronómico Nacional, situado en la Sierra de San Pedro Mártir (Baja California, México), cumplira en un futuro muy cercano siete años de uso para fines de investigación astronómica. Aunque en este tiempo no se ha efectuado un estudio sistemático acerca de su comportamiento óptico y de los factores que influyen en la calidad de las imágenes, se han realizado pruebas diversas, estudios parciales y reuniones especificas, cuyos resultados no siempre se han difundido ampliamente y generalmente no se han presentado por escrito. Es por ello que hemos creido necesario intentar una recopilación de la información existente para poder con ella establecer un diagnóstjco que, aunque no sea definitivo, sirva de base para futuros trabajos tendientes a optimizar el comportamiento óptico del telescopio. Es evidente que un buen número de las conclusiones que se presentan son resultado del trabajo de muchas personas ó de esfuerzos colectivos. Asimismo, hemos tratado de localizar información bibliográfica que pueda ser de utilidad. Nuestro objetivo primordial ha consistido en centrarnos en la óptica del telescopio y su calidad, pero también se han considerado otros aspectos que puedan afectar las imágenes obtenidas tales como: celda del primario, `seeing' local y externo, flexiones posibles en la estructura mecánica del telescopio, etc.

  10. Visiting the Gödel universe.

    PubMed

    Grave, Frank; Buser, Michael

    2008-01-01

    Visualization of general relativity illustrates aspects of Einstein's insights into the curved nature of space and time to the expert as well as the layperson. One of the most interesting models which came up with Einstein's theory was developed by Kurt Gödel in 1949. The Gödel universe is a valid solution of Einstein's field equations, making it a possible physical description of our universe. It offers remarkable features like the existence of an optical horizon beyond which time travel is possible. Although we know that our universe is not a Gödel universe, it is interesting to visualize physical aspects of a world model resulting from a theory which is highly confirmed in scientific history. Standard techniques to adopt an egocentric point of view in a relativistic world model have shortcomings with respect to the time needed to render an image as well as difficulties in applying a direct illumination model. In this paper we want to face both issues to reduce the gap between common visualization standards and relativistic visualization. We will introduce two techniques to speed up recalculation of images by means of preprocessing and lookup tables and to increase image quality through a special optimization applicable to the Gödel universe. The first technique allows the physicist to understand the different effects of general relativity faster and better by generating images from existing datasets interactively. By using the intrinsic symmetries of Gödel's spacetime which are expressed by the Killing vector field, we are able to reduce the necessary calculations to simple cases using the second technique. This even makes it feasible to account for a direct illumination model during the rendering process. Although the presented methods are applied to Gödel's universe, they can also be extended to other manifolds, for example light propagation in moving dielectric media. Therefore, other areas of research can benefit from these generic improvements. PMID

  11. Vigilando la Calidad del Agua de los Grandes Rios de la Nacion: El Programa NASQAN del Rio Grande (Rio Bravo del Norte)

    USGS Publications Warehouse

    Lurry, Dee L.; Reutter, David C.; Wells, Frank C.; Rivera, M.C., (translator); Munoz, A.

    1998-01-01

    La Oficina del Estudio Geologico de los Estados Unidos (U.S. Geological Survey, 0 USGS) ha monitoreado la calidad del agua de la cuenca del Rio Grande (Rio Bravo del Norte) desde 1995 como parte de la rediseiiada Red Nacional para Contabilizar la Calidad del Agua de los Rios (National Stream Quality Accounting Network, o NASOAN) (Hooper and others, 1997). EI programa NASOAN fue diseiiado para caracterizar las concentraciones y el transporte de sedimento y constituyentes quimicos seleccionados, encontrados en los grandes rios de los Estados Unidos - incluyendo el Misisipi, el Colorado y el Columbia, ademas del Rio Grande. En estas cuatro cuencas, el USGS opera actualmente (1998) una red de 40 puntos de muestreo pertenecientes a NASOAN, con un enfasis en cuantificar el flujo en masa (la cantidad de material que pasa por la estacion, expresado en toneladas por dial para cada constituyente. Aplicacando un enfoque consistente, basado en la cuantificacion de flujos en la cuenca del Rio Grande, el programa NASOAN esta generando la informacion necesaria para identificar fuentes regionales de diversos contaminantes, incluyendo sustancias qui micas agricolas y trazas elementos en la cuenca. EI efecto de las grandes reservas en el Rio Grande se puede observar segun los flujos de constituyentes discurren a 10 largo del rio. EI analisis de los flujos de constituyentes a escala de la cuenca proveera los medios para evaluar la influencia de la actividad humana sobre las condiciones de calidad del agua del Rio Grande.

  12. Educational and Demographic Profile: Del Norte County.

    ERIC Educational Resources Information Center

    California Postsecondary Education Commission, 2004

    2004-01-01

    This profile uniquely presents a variety of educational and socioeconomic information for Del Norte County, nearby counties, and the state. The profile highlights the relationship between various factors that affect the economic well-being of individuals and communities. This presentation of information provides a framework for enhanced…

  13. Del Mod System. 1972 Annual Report.

    ERIC Educational Resources Information Center

    Purnell, Charlotte H.

    The overall aim of the Del Mod System is the improvement of science programs taught in Delaware schools; it is a working agreement among the University of Delaware, Delaware Technical and Community College, Delaware State College, State Department of Public Instruction, industry, and the schools. It was formed to bring about changes in science…

  14. Andrea del Sarto rehabilitated: a psychoanalytic emendation.

    PubMed

    Trosman, Harry

    2002-01-01

    Ernest Jones's "The Influence of Andrea del Sarto's Wife on His Art" (1913) is an early example of psychoanalysis applied to the study of a prominent painter. Greatly influenced by Freud's Leonardo da Vinci and a Memory of His Childhood, Jones gave excessive credence to Vasari's highly prejudicial account of the life of del Sarto, on which the study relied heavily. Jones attempted to account psychologically for the circumstance that del Sarto, though highly skilled and "faultless," was not the equal of the three preeminent masters of the Italian High Renaissance: Leonardo, Michelangelo, and Raphael. Jones's uncritical acceptance of the Vasari biography encouraged him to view Sarto's assumed deficiency as the result of excessive attachment to his wife, a pathological uxoriousness. A contemporary psychoanalytic perspective, with its emphasis on the emotive response of the analyst, requires us to pay attention to the evocative nature of the work of the artist, an approach Jones neglected. In an examination of several paintings, the artist's sensitivity to the position of the spectator is explored, as is the interest in involving the viewer spatially and emotionally. An appreciation for the viewer's position is consistent with a capacity for using projected internal objects for creative purposes. The presence of this capacity suggests a revised view of del Sarto's contribution to art and of his relationship with his wife. PMID:12580329

  15. Clinical and laboratory update on the DEL variant.

    PubMed

    Nuchnoi, Pornlada; Thongbus, Jairak; Srisarin, Apapan; Kerdpin, Usanee; Prachayasittikul, Virapong

    2014-01-01

    Serological assays for the RhD blood group are based on detection of the RhD antigen on human red blood cells using a specific anti-D antibody. The weak expression of the RhD antigen in the DEL variant hinders the sensitivity of conventional serological assays. Evidence of anti-D immunization in patients with D-negativity who have received DEL-variant blood units has been reported in various populations. This observation has prompted the need for genetic epidemiological and clinical data on the DEL variant in the development of DEL molecular diagnostic testing. This review highlights the molecular features of the DEL variant, the clinical consequences of DEL-blood transfusion, and current approaches for detection of the DEL-variant for donor screening and transfusion. PMID:25316658

  16. Del Norte means north to recycling

    SciTech Connect

    Aquino, J.T.

    1998-06-01

    Del Norte Regional Recycling and Transfer Station is owned by the city of Oxnard, California and operated by BLT Enterprises, Inc. The Del Norte facility--located in southwestern Ventura County about an hour northwest of Los Angeles--processes polyethylene terephthalate (PET) and high-density polyethylene (HDPE) plastic containers, aluminum, steel, glass, old corrugated containers (OCC), newspapers, computer printout paper, white and colored ledger paper, coated book, supermix paper, telephone books, and old magazines. According to the company, there has been virtually no community opposition to the site. The facility has few neighbors, and those are agricultural. To keep the community relationship strong, the facility`s design and location all but eliminated odor and noise complaints. The building was designed against the prevailing wind pattern, and BLT processes odorous material fast. A misting system installed for dust suppression also can be used with a solution for odor control should the need arise.

  17. del, Einstein, Mach, Gamow, and Lanczos: Gödel's remarkable excursion into cosmology

    NASA Astrophysics Data System (ADS)

    Rindler, Wolfgang

    2009-06-01

    This article is an expanded version of a talk given at the International Symposium Celebrating the 100th Birthday of Kurt Gödel (Vienna, 2006). It seeks to trace the path which led this preeminent mathematical logician to discover one of the famous results of General Relativity, the rotating Gödel Universe. This universe has some remarkable properties, which gave the philosophers plenty to worry about. It allows a person to travel into his own past, with all the ensuing causal paradoxes; it allows no unique temporal ordering of events; and though Gödel's Universe is rigid and infinite, the Foucault pendulum planes everywhere in it rotate in unison, a clear affront to adherents of Mach's Principle. We also discuss some lesser known precursors in the field, who just missed discovering Gödel's universe. While the article gives all the necessary derivations in simplified form (for example, of the metric and its geodesics), much of it should be accessible to the general reader, who can simply skip most of the mathematics. [Reprinted, with permission, from Kurt Gödel and the Foundations of Mathematics: Horizons of Truth, edited by Matthias Baaz, Christos H. Papadimitriou, Dana S. Scott, Hilary Putnam, and Charles L. Harper, Jr. (Cambridge U. P., New York, 2009).

  18. Procesamiento Digital de Imagenes del Cometa Halley

    NASA Astrophysics Data System (ADS)

    Ferrin, L.; Fuenmayor, F.; Naranjo, O.; Bulka, P.; Mendoza, C.

    1987-05-01

    Se reportan observaciones fotográficas del cometa Halley, obtenidas con los telescopios Schmidt de 1-m del CIDA, y de 35 cms de la ULA. Se hicieron exposiciones desde 2 segundos a 30 minutos y se utilizaron emulsiones IIa-O, 103a-F, y 103a-D, guladas manualmente 0 automaticámente. Las imágenes fueron digitalizadas con el microdensitómetro PDS, y procesadas con el sistema HACIENDA del CCIBM. Se experimentó con la Transformada de Fourier en dos dimensiones, y con la aplicación de filtros de paso alto y bajo. Se encontró que el metodo de "autocorrelación" es el mejor para separar "la vegetación" de "la montaña". Se aplicaron diversas técnicas a fin de cubrir ambos extremos: a) enfatizar detalles débiles en la cola, y b) penetrar en las regiones más intensas de la coma. Se lograron ambos objetivos. Detalles en la cola permitieron determinar velocidades de propagación de unos 50 a 90 kms/ seg. Se pudieron detectar no menos de tres perturbaciones en "Y", y una en 5? Co de Cisne). Se cree que las primeras están asociadas a eventos de desconexión. Se puede separar la cola de gas de la de polvo. Las fotos de color permiten enfatizar diferentes regiones espectrales con mayor claridad aún. El "balance" del color puede ser hecho con la computadora.

  19. Visualization of the Gödel universe

    NASA Astrophysics Data System (ADS)

    Buser, M.; Kajari, E.; Schleich, W. P.

    2013-01-01

    The standard model of modern cosmology, which is based on the Friedmann-Lemaître-Robertson-Walker metric, allows the definition of an absolute time. However, there exist (cosmological) models consistent with the theory of general relativity for which such a definition cannot be given since they offer the possibility for time travel. The simplest of these models is the cosmological solution discovered by Kurt Gödel, which describes a homogeneous, rotating universe. Disregarding the paradoxes that come along with the abolishment of causality in such space-times, we are interested in the purely academic question of how an observer would visually perceive the time travel of an object in Gödel's universe. For this purpose, we employ the technique of ray tracing, a standard tool in computer graphics, and visualize various scenarios to bring out the optical effects experienced by an observer located in this universe. In this way, we provide a new perspective on the space-time structure of Gödel's model.

  20. Morphology, geology and geochemistry of the "Salar del Gran Bajo del Gualicho" (Rio Negro, Argentina)

    USGS Publications Warehouse

    Angelucci, A.; Barbieri, M.; Brodtkorb, A.; Ciccacci, S.; Civitelli, G.; De Barrio, R.; Di, Filippo M.; Fredi, P.; Friedman, I.; Lombardi, S.; Schalamuk, A.I.; Toro, B.

    1996-01-01

    A multidisciplinary study of the Gran Bajo del Gualicho area (Rio Negro - Argentina) was carried out; the aim was to delineate its geological and geomorphological evolution and to estabilish the genesis of salts filling the depression. Climatic conditions were analized first to individuate their role in the present morphogenetic processes; moreover the main morphological features of present landscape were examined as well as the stratigraphy of the outcropping formations, and of the Gran Bajo del Gualicho Formation in particular. Finally, a possible geomorphological evolution of the studied area was traced. Geophysical analyses allowed to estabilish that the paleosurface shaped on the crystalline basement is strongly uneven and shows evidence of the strong tectonic phases it underwent. The result of isotope analyses confirmed that the salt deposits on the Gran Bajo del Gualicho bottom were produced by fresh water evaporation, while strontium isotope ratio suggested that such waters were responsible for solubilization of more ancient evaporitic deposits.

  1. A Description of Del Mod and Its Final Evaluation, Final Report, Volume I.

    ERIC Educational Resources Information Center

    Purnell, Charlotte H.; Bolig, John R.

    This monograph presents an overview of five Del Mod System final reports, comments by the project director, financial structure of the Del Mod System, and descriptions of Del Mod Projects. The Del Mod System was concerned with changing the science and mathematics education programs in the state of Delaware. Between 1970 and 1976, Del Mod conducted…

  2. Huave de San Mateo del Mar, Oaxaca (Huave of San Mateo del Mar, Oaxaca).

    ERIC Educational Resources Information Center

    Mexico Coll. (Mexico City)

    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 Huave, an indigenous language of Mexico spoken in San Mateo del Mar, in the state of Oaxaca. The objective of collecting such a representative sampling of…

  3. Instantánea del sarcoma de Kaposi

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el sarcoma de Kaposi; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  4. Pastoral del Nino: Bringing the Abundant Life to Paraguayan Children

    ERIC Educational Resources Information Center

    Austin, Ann Berghout; Aquino, Cyle; Burro, Elizabeth

    2007-01-01

    Pastoral del Nino is transforming children's lives in rural Paraguay. Part of Pastoral Social (Catholic Social Services), Pastoral del Nino's primary focus is to bring "vida en abundancia" (the abundant life) to families by ensuring that mothers survive childbirth and children reach their first birthdays. In addition, the organization promotes…

  5. 75 FR 11104 - Del Norte Resource Advisory Committee (RAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-10

    ... Forest Service Del Norte Resource Advisory Committee (RAC) AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Del Norte Resource Advisory Committee (RAC) will meet in Crescent City... and Designated Federal Official roles and (5) review operational guidelines; (6) selection of...

  6. Research and Evaluation Within the Del Mod System.

    ERIC Educational Resources Information Center

    Bolig, John R.

    Described is the Del Mod System, its inception, the fundings associated with it, and its objectives. A number of projects have already been completed and implemented. This monograph describes the evaluations of such projects and of the Del Mod systems-approach to science education. The area of evaluation and the method of data collection (with…

  7. 33 CFR 80.1118 - Marina Del Rey, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Marina Del Rey, CA. 80.1118 Section 80.1118 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1118 Marina Del Rey, CA. (a) A line drawn...

  8. Instantánea del cáncer colorrectal

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer colorrectal; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  9. A new iterative Chebyshev spectral method for solving the elliptic equation [del] [center dot] ([sigma] [del]u) = f

    SciTech Connect

    Zhao, Shengkai; Yedlin, M.J. )

    1994-08-01

    We present a new iterative Chebyshev spectral method for solving the elliptic equation [del] [center dot] ([sigma] [del]u) = f. We rewrite the equation in the form of a Poisson's equation [del][sup 2]u = (f - [del]u [center dot] [del][sigma]/[sigma]). In each iteration we compute the right-hand side terms from the guess values first. Then we solve the resultant Poisson equation by a direct method to obtain the updated values. Three numerical examples are presented. For the sam number of iterations, the accuracy of the present method is about 6-8 orders better than the Chebyshev spectral multigrid method. On a SPARC Station 2 computer, the CPU time of the new method is about one-third of the Chebyshev spectral multigrid method. To obtain the same accuracy, the CPU time of the present method is about one-tenth of the Chebyshev spectral multigrid method. 17 refs., 5 figs., 3 tabs.

  10. Estudio teórico del CO2. Orbitales de valencia y del ``core''

    NASA Astrophysics Data System (ADS)

    Olalla Gutiérrez, E.

    Hemos calculado las intensidades de las transiciones E1 a los miembros de las series de Rydberg con origen en los orbitales ``no enlazantes'' del dióxido de carbono, especie de conocida relevancia atmosférica. Se han computado, asimismo, los continuos de fotoionización correspondientes a los distintos canales de ionización, representándolos como densidad espectral de fuerza de oscilador frente a la energía del fotón incidente; mostramos los resultados df/dE para la fotoionización total de esta especie en el intervalo 15-60 eV. Todos los cálculos se han llevado a cabo mediante la formulación Molecular del Método de los Orbitales de Defecto Cuántico, MQDO [1,2]. La calidad de los resultados que presentamos se ha evaluado en base a la comparación con los datos, tanto experimentales como teóricos, disponibles en la bibliografía. El acuerdo encontrado es altamente satisfactorio

  11. Neurological aspects of del(1q) syndrome.

    PubMed

    Murayama, K; Greenwood, R S; Rao, K W; Aylsworth, A S

    1991-09-15

    We have studied three children with de novo terminal deletion of the long arm of chromosome 1 (46,XX,del(1)(q43)). They all have minor anomalies and neurological signs (severe psychomotor developmental delay, generalized hypotonia, and seizures) that have been described previously. In addition, all of these three patients have autistic-like behavior. They avoid eye contact, show no interest in people, express little emotion, and repeat stereotypic movements such as head nodding and purposeless finger manipulation. They also spend excessive time in making unusual sounds consisting of a high-pitched shrill cry with little intonation in infancy and a harsh, strained, and glottal stridency in later life. They make no labial, lingual, or nasal sounds. We suggest that these observations may be unique clinical manifestations of certain terminal 1q deletions. PMID:1746617

  12. Illuminating water and life: Emilio Del Giudice.

    PubMed

    Ho, Mae-Wan

    2015-01-01

    The quantum electrodynamics theory of water put forward by Del Giudice and colleagues provides a useful foundation for a new science of water for life. The interaction of light with liquid water generates quantum coherent domains in which the water molecules oscillate between the ground state and an excited state close to the ionizing potential of water. This produces a plasma of almost free electrons favoring redox reactions, the basis of energy metabolism in living organisms. Coherent domains stabilized by surfaces, such as membranes and macromolecules, provide the excited interfacial water that enables photosynthesis to take place, on which most of life on Earth depends. Excited water is the source of superconducting protons for rapid intercommunication within the body. Coherent domains can also trap electromagnetic frequencies from the environment to orchestrate and activate specific biochemical reactions through resonance, a mechanism for the most precise regulation of gene function. PMID:26098522

  13. Wave maps from Gödel's universe

    NASA Astrophysics Data System (ADS)

    Barletta, Elisabetta; Dragomir, Sorin; Magliaro, Marco

    2014-10-01

    Using a result by Koch (1988 Trans. Am. Math. Soc. 307 827-41) we realize Gödel's universe G_{α }^{4}=({{{R}}^{4}},{{g}_{α}}) as the total space of a principal {R}-bundle over a strictly pseudo-convex CR manifold M3 and exploit the analogy between {{g}_{Yalpha;}} and Fefferman's metric {{F}_{θ}} (Fefferman 1976 Ann. Math. 103 395-416 104 393-4) to show that for any {R}-invariant wave map Φ of G_{α}^{4} into a Riemannian manifold N, the corresponding base map φ :{{M}^{3}}\\to N is subelliptic harmonic, with respect to a canonical choice of contact form θ on M3. We show that the subelliptic Jacobi operator J_{b}^{φ} of ϕ has a discrete Dirichlet spectrum on any bounded domain D\\subset {{M}^{3}} supporting the Poincaré inequality on \\mathop{W}\\limits^{\\circ }{}_{H}^{1,2}(D,{{φ}^{-1}}TN) and Kondrakov compactness, i.e. compactness of the embedding \\mathop{W}\\limits^{\\circ }{}_{H}^{1,2}(D,{{φ }^{-1}}TN)\\hookrightarrow {{L}^{2}}(D,{{φ}^{-1}}TN). We exhibit an explicit solution π :G_{α}^{4}\\to {{M}^{3}} to the wave map system on G_{α}^{4}, of index in{{d}^{Ω}}(π)\\geqslant 1 for any bounded domain Ω \\subset G_{α}^{4}. Mounoud's distance (Mounoud 2001 Differ. Geom. Appl. 15 47-57) d_{{{G}_{0}}, Ω }^{∞}({{g}_{α }}, {{F}_{θ}}) is bounded below by a constant depending only on the rotation frequency of Gödel's universe, thus giving a measure of the bias of {{g}_{α}} from being Fefferman like in the region Ω \\subset {{{R}}^{4}}.

  14. The Del Mod System: An External Evaluation, Final Report, Volume IV.

    ERIC Educational Resources Information Center

    Humphreys, Donald W.; And Others

    This is one of five volumes prepared to describe various aspects of the Del Mod System. This volume deals with the evaluation of the Del Mod System. Included are the following: (1) Del Mod Responsive Evaluation; (2) Evaluation Outcomes; (3) Validation of the Del Mod Responsive Evaluation Process; and (4) Conclusions. Appendices include: (A)…

  15. A Descriptive Analysis of the Del Mod System's Field Agent Component, Final Report, Volume III.

    ERIC Educational Resources Information Center

    Golts, Uldis R.

    This monograph describes the field agent of the Delaware Del Mod System. The following sections are included in the report: (1) The Duties and Activities of the Del Mod System Field Agents; (2) The Field Agents' Mode of Operation; (3) The Conduct of Projects; (4) The Hiring and Training of Del Mod Field Agents; (5) The Administration of Del Mod…

  16. Migration of recharge waters downgradient from the Santa Catalina Mountains into the Tucson basin aquifer, Arizona, USA

    NASA Astrophysics Data System (ADS)

    Cunningham, Erin E. B.; Long, Austin; Eastoe, Chris; Bassett, R. L.

    'origine thermonucléaire permettent de caractériser qualitativement les cheminements de l'eau et leurs vitesses. Les isotopes stables ne mettent pas en évidence un effet d'altitude. Les teneurs en tritium indiquent que quelques sources et certains puits fournissent une eau ancienne, alors que l'eau de la plupart des sources date des années soixante ou est plus récente. Resumen Los acuíferos en las cuencas aluviales áridas del sudoeste de los Estados Unidos de América se recargan principalmente por la infiltración procedentes de los arroyos y playas de las propias cuencas y por entradas a lo largo de los límites de las mismas. La cuenca de Tucson, en el sudeste de Arizona es una de ellas. Las Montañas de Santa Catalina forman el contorno septentrional de esta cuenca y reciben una precipitación de más del doble (700mm/año) que la media de la propia cuenca (unos 300mm/año). En este estudio, se utilizaron isótopos ambientales para investigar la infiltración a través de fracturas y juntas superficiales. Se obtuvieron muestras de manantiales y de la escorrentía en las Montañas de Santa Catalina, así como de pozos ubicados al pie de las mismas. Los isótopos estables (Deuterio y Oxígeno-18) y el Tritio procedente de las bombas termonucleares permitieron la caracterización cualitativa de las líneas de flujo y de las velocidades. Los datos procedentes de la medida de isótopos estables no parecen presentar un efecto de altitud. Los valores de Tritio indican que aunque algunos pozos y manantiales descargan agua previa a los ensayos termonucleares, la mayoría descargan aguas de fecha posterior a 1960.

  17. Centro para la Salud Mundial (CGH) del NCI

    Cancer.gov

    El Centro para la Salud Mundial (CGH) del NCI coordina actividades de investigación y trabaja con socios nacionales e internacionales para comprender y enfrentar la carga que representa el cáncer a nivel mundial.

  18. Living Legacy: A Conversation with Carolina Gomez del Valle.

    ERIC Educational Resources Information Center

    Montessori Life, 1993

    1993-01-01

    Carolina Gomez del Valle has been involved in training other Montessorians in Mexico, Chile, Nicaragua, Peru, and Taiwan. This interview explores her experiences with Montessori education and describes how she has woven her religious training and Montessori philosophy together. (PAM)

  19. 88. Paso Del Norte Hotel, 115117 South El Paso St., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    88. Paso Del Norte Hotel, 115-117 South El Paso St., south facade, west side of street - South El Paso Street Historic District, South El Paso, South Oregon & South Santa Fe Streets, El Paso, El Paso County, TX

  20. 91. Paso Del Norte Hotel, 115117 South El Paso St., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    91. Paso Del Norte Hotel, 115-117 South El Paso St., east facade, west side of street - South El Paso Street Historic District, South El Paso, South Oregon & South Santa Fe Streets, El Paso, El Paso County, TX

  1. PASO DEL NORTE HOTEL, 115117 S. EL PASO ST., SOUTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PASO DEL NORTE HOTEL, 115-117 S. EL PASO ST., SOUTH AND EAST FACADES, WEST SIDE OF STREET - South El Paso Street Historic District, South El Paso, South Oregon & South Santa Fe Streets, El Paso, El Paso County, TX

  2. 92. Paso Del Norte Hotel, 115117 South El Paso St., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    92. Paso Del Norte Hotel, 115-117 South El Paso St., interior, lobby rotunda - South El Paso Street Historic District, South El Paso, South Oregon & South Santa Fe Streets, El Paso, El Paso County, TX

  3. PASO DEL NORTE HOTEL, 115117 S. EL PASO ST., EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PASO DEL NORTE HOTEL, 115-117 S. EL PASO ST., EAST FACADE, WEST SIDE OF STREET - South El Paso Street Historic District, South El Paso, South Oregon & South Santa Fe Streets, El Paso, El Paso County, TX

  4. Se evitaron casi 800 000 muertes por descenso del tabaquismo

    Cancer.gov

    Programas y estrategias de control del tabaco del siglo XX fueron responsables de la prevención de más de 795 000 muertes por cáncer de pulmón en Estados Unidos de 1975 al 2000. Si todo el tabaquismo en este país hubiera cesado después de la publicación d

  5. Estudio del sistema simbiótico AR Pavonis

    NASA Astrophysics Data System (ADS)

    Quiroga, C.; Brandi, E.; Ferrer, O.; García, L.; Barbá, R.

    Se presenta un estudio espectroscópico y polarimétrico de la binaria eclipsante AR Pavonis a partir de observaciones obtenidas con el telescopio de 2.15 m. del CASLEO (San Juan). El estudio de la naturaleza del sistema se realizó a través del análisis de algunos espectros reunidos entre los años 1990 y 1995 y de datos polarimétricos correspondientes al intervalo 1995 y 1997. El análisis espectroscópico indica que AR Pav está compuesta por una gigante roja M3.7 y una componente caliente compacta, con una temperatura mayor a 90000 K y una luminosidad del orden de 500Lsolar. A lo largo del período orbital, las variaciones observadas en flujo y en velocidades radiales, reflejan que las emisiones permitidas se forman en una región que rodea la componente caliente. El estudio de la polarización lineal de AR Pav indica que además de una componente interestelar, existe una componente intrínseca del sistema que varía temporalmente y con la longitud de onda de la luz polarizada. El distinto comportamiento del grado de polarización y del ángulo de posición observado en fases diferentes, sugiere que distintos mecanismos pueden estar actuando, dependiendo de la región de scattering observado a lo largo de la línea de la visual.

  6. 65. Photographer unknown March 1931 DEL NORTE COUNTY, SECTION B, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    65. Photographer unknown March 1931 DEL NORTE COUNTY, SECTION B, HIGHWAY 1, 1-DN-1-B #66A, STA. 166.0+00 WIDENED ROADBED BEFORE COVERING LOG CRIB, 3-31. BACK READS: WIDENING ROAD BED WITH LOGS, APPROX 30 SQUARE & 60 LONG ON DN-1 SEC B STA 156+. Stamped office copy, - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

  7. Extreme Environments in Tierra del Fuego, Argentina

    NASA Astrophysics Data System (ADS)

    Schultz, C.; D'Antoni, H.; Burgess, S.; Zamora, J.; Skiles, J.

    2007-12-01

    The upper timberline of the Andes Cordillera on the island of Tierra del Fuego at the tip of South America is an environment subject to extreme conditions. In order to further understand this environment, ecosystem parameters were measured within two transects of the Andes at Glaciar Martial and Cerro Guanaco. The measurements included pH, soil temperature, soil moisture, nitrogen, sodium and potassium concentration, chlorophyll absorbance, and irradiance in the ultraviolet range (200-400 nm). These data comprise a survey that serves as a baseline for an intensive research program. Chlorophyll concentration and soil data were within the range of our observations at several other sites, from Lapataia Bay on the southwestern boundary with Chile, through the eastern end of Lake Fagnano. However, unusual levels of solar irradiance were found in the open sites of both transects while those in the forest exhibited lower UV values, suggesting strong absorption and/or reflection by the forest canopy. High levels of UV radiation damage important biomolecules and may be partially responsible for the presence of life forms such as the krummholz belt in the upper timberline. These UV values may be due to the effects of global ozone depletion and the ozone hole. The low temperatures, strong winds, snow and ice-covered soil and especially the exposure to UV radiation make this area an extreme environment for life.

  8. Alloimmunization of patients by blood units harboring distinct DEL variants.

    PubMed

    St-Louis, Maryse; Lebrun, André; Goldman, Mindy; Lavoie, Marianne

    2013-01-01

    The alloimmunization potential of many RHD variants is unknown, and it can be explored by lookback and traceback studies. Hema-Quebec (HQ) investigated the RHD status of 3980 D- repeat blood donors. Thirteen were found to be RHD positive: 4 RHD*1p, and 1 RHD*487delACAG, which show a Dphenotype;and 1 RHD*885T and 7 RHD*(93-94insT) causing a DEL phenotype when C antigen is present. Look back studies were done to verify the alloimmunization potential of these eight DEL donors. Coincidentally, Canadian Blood Services (CBS)performed a trace back study by investigating the RHD status of donors after aD- recipient developed anti-Dafter transfusion of two D- red blood cell (RBC) units. Donor genotyping was done either manually (HQ) or using the Progenika Bloodchip platform(CBS). Donations were traced through computer records. Letters were sent to hospital blood bank physicians to verify the presence of anti-Din recipients and to donors to request repeat samples.A total of 118 RBC units were transfused, 82 to D- recipients.Anti-D was found in three patients transfused with RHD*(93-94insT) DEL red blood cells. One donor presenting the same DEL variant was involved in the trace back study. Even without strong evidence clearly demonstrating the alloimmunization potential of DEL variants, whenever HQ or CBS identifies a donor harboring a DEL phenotype, his or her D status will be changed from DtoD+ to protect against the potential alloimmunization risk. PMID:24689683

  9. Estudio multifrecuencia del medio interestelar cercano a HD 192281

    NASA Astrophysics Data System (ADS)

    Arnal, E. M.; Cappa, C.; Cichowolski, S.; Pineault, S.; St-Louis, N.

    Una de las causas que modifica la estructura y dinámica del medio interestelar es la acción que los vientos de las estrellas de gran masa ejercen sobre el mismo. En este trabajo, mediante el uso de datos interferométricos obtenidos en la banda de radio en la transición de 21-cm del Hidrógeno neutro y de imágenes de la emisión de continuo en las bandas de 408 y 1420 MHz, de imágenes HIRES del satélite IRAS en 60 y 100 micrones, y de observaciones de continuo obtenidas con radiotelescopios de disco simple en 2695, 4850 y 8350 MHz se ha realizado un estudio multifrecuencia de los efectos que los vientos estelares de HD 192281, una estrella de tipo espectral O5 Vn((f))p, han tenido sobre el medio interestelar que rodea a la misma.

  10. May Gödel's Ideas Be Addressed Philosophically?

    NASA Astrophysics Data System (ADS)

    Dokulil, Miloš

    2007-11-01

    del emphasised philosophy as an important tool in science. Much less is known about his religious background. We should bear in mind that our evaluational perspective differs very much from the one in which Gödel lived. He was personally sure that there must be another existence after death-an afterlife (''of unlimited life span''). As a ''Baptized Lutheran'' he did not include ''Trinity'' in his creed. He was also certain that mind is separate from matter. This text tries to include Libet's ''readiness potential'' into the debate concerning the specificity of the mind. Neither Gödel's identification of materialism with mechanism nor his vision of the ''spirit'' are a viable solution of the problem.

  11. Field measurements of del13C in ecosystem respiration

    NASA Astrophysics Data System (ADS)

    van Asperen, Hella; Sabbatini, Simone; Nicolini, Giacomo; Warneke, Thorsten; Papale, Dario; Notholt, Justus

    2014-05-01

    Stable carbon isotope del13C-measurements are extensively used to study ecological and biogeochemical processes in ecosystems. Above terrestrial ecosystems, atmospheric del13C can vary largely due to photosynthetic fractionation. Photosynthetic processes prefer the uptake of the lighter isotope 12C (in CO2), thereby enriching the atmosphere in 13C and depleting the ecosystem carbon. At night, when ecosystem respiratory fluxes are dominant, 13C-depleted CO2 is respired and thereby depletes the atmospheric del13C-content. Different ecosystems and different parts of one ecosystem (type of plant, leaves, and roots) fractionate and respire with a different del13C-ratio signature. By determining the del13C-signature of ecosystem respiration in temporal and spatial scale, an analysis can be made of the composition of respiratory sources of the ecosystem. A field study at a dry cropland after harvest (province of Viterbo, Lazio, Italy) was performed in the summer of 2013. A FTIR (Fourier Transform Infrared Spectrometer) was set up to continuously measure CO2-, CH4-, N2O-, CO- and del13C-concentrations. The FTIR was connected to 2 different flux measurements systems: a Flux Gradient system (sampling every half hour at 1.3m and 4.2m) and 2 flux chambers (measured every hour), providing a continuous data set of the biosphere-atmosphere gas fluxes and of the gas concentrations at different heights. Keeling plot intercept values of respiratory CO2, measured by the Flux Gradient system at night, were determined to be between -25‰ and -20‰. Keeling plot intercept values of respiratory CO2, measured by the flux chamber system, varied between -24‰ and -29‰, and showed a clear diurnal pattern, suggesting different (dominant) respiratory processes between day and night.

  12. Symmetries of geodesic motion in Gödel-type spacetimes

    SciTech Connect

    Camci, U.

    2014-07-01

    In this paper, we study Noether gauge symmetries of geodesic motion for geodesic Lagrangian of four classes of metrics of Gödel-type spacetimes for which we calculated the Noether gauge symmetries for all classes I-IV, and find the first integrals of corresponding classes to derive a complete characterization of the geodesic motion. Using the obtained expressions for t-dot , r-dot ,φ-dot and ż of each classes I-IV which depends essentially on two independent parameters m and w, we explicitly integrated the geodesic equations of motion for the corresponding Gödel-type spacetimes.

  13. Outcome following haematopoietic cell transplantation in patients with myelodysplasia and del (5q) karyotypes.

    PubMed

    Stewart, B; Verdugo, M; Guthrie, K A; Appelbaum, F; Deeg, H J

    2003-12-01

    The deletion (5q) karyotype [del (5q)] in patients with myelodysplastic syndrome (MDS) is considered a good risk feature, while the impact of del (5q) combined with other karyotypic abnormalities [del (5q)+] is less well defined. We analysed the outcome of haematopoietic cell transplants (HCT) in patients with MDS with del (5q) or del (5q)+. Fifty-seven patients, aged 6-72 years, with MDS and del (5q) abnormalities received HCT from related (n = 32) or unrelated (n = 25) donors. By French-American-British (FAB) criteria, 27 patients had refractory anaemia (RA), 10 RA with excess blasts (RAEB), eight RAEB in transformation (RAEB-T) and 12 acute myeloid leukaemia evolving from MDS (tAML). Non-relapse mortality at 1-year post-transplantation was 30% for del (5q) and 38% for del (5q)+ patients. Relapse occurred in one of 20 del (5q) patients and 15 of 37 del (5q)+ patients (P = 0.001). After adjusting for del (5q) status, blast count (<5%) was the only factor significantly associated with relapse-free survival. Patients with del (5q), either as a '5q- syndrome' or with MDS in general, had better outcomes than did patients with del (5q)+. The indication for transplantation in patients with del (5q) was generally severe cytopenias, compared with disease progression to a more advanced FAB stage in patients with del (5q)+. Conceivably, outcome for patients with del (5q)+ would be improved with transplantation earlier in the disease course. PMID:14632779

  14. Using GIS to study the past and present of a northern Chihuahuan Desert playa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The encroachment of mesquite (Prosopis glandulos Torr.) and other desert shrubs into the desert grasslands of the northern Chihuahuan Desert is commonly associated with increased rates of soil erosion. The processes associated with vegetation shifts are still poorly understood. One such example of v...

  15. Self-Esteem through Play--A Natural for Special Children.

    ERIC Educational Resources Information Center

    Shriver, Eunice Kennedy

    1984-01-01

    Let's Play to Grow, a club for families with handicapped children, helps special children develop social and recreational skills. Special families meet monthly to learn how to enjoy and accept themselves. Parents develop relationships with other families with similiar problems. (DF)

  16. What We Know about Play--A Walk through Selected Research.

    ERIC Educational Resources Information Center

    Oliver, Susan J.; Klugman, Edgar

    2002-01-01

    Describes the "Playing for Keeps" project of maintaining a comprehensive, categorized database summarizing current knowledge on play. Presents selected findings and information about: child development theories, studies about the developmental benefits of play, investigations into why play is useful for children, and documentation of the impact of…

  17. The Sign Told Me how to Play--A Lesson in Risk Reduction.

    ERIC Educational Resources Information Center

    Wallach, Frances

    1988-01-01

    Two constantly appearing claims in most playground accident suits are improper supervision and lack of warning to the users. This article discusses legal implications of improper signage, explains use of symbols, and presents general sign guidelines to ensure proper safety measures. (MLH)

  18. Play--A Multi-Modal Manifestation in Kindergarten Education in China

    ERIC Educational Resources Information Center

    Vong, Keang-Ieng

    2012-01-01

    Play, as an educational concept, has entered many kindergartens in China; yet it has not become a core idea, or been prioritised in the teaching and learning process. An ongoing trans-provincial study started in 2008, using observation, interviews and document analyses. Based on findings from nine kindergartens in three provinces, this article…

  19. Australian Acid Playa Lake as a Mars Analog: Results from Sediment Lipid Analysis

    NASA Astrophysics Data System (ADS)

    Graham, H.; Baldridge, A. M.; Stern, J. C.

    2015-12-01

    The ephemeral saline acidic lakes on the Yilgarn Craton of Western Australia have been suggested as geochemical analogues to martian terrains. Both are characterized by interbedded phyllosilicates and hydrated sulfates. On Mars, these areas indicate shifting environmental conditions, from the neutral/alkaline and wet conditions that dominated during the Noachian era to the more familiar dry, acidic conditions that began in the Hesperian. The habitability of such a dynamic environment can be informed by investigation of the Yilgarn Lake system. Previous work has found phospholipid fatty acids (PLFA) evidence of microbial communities in sections of sediment cores taken from Lake Gilmore. These communities include both Gram-positive and -negative bacteria, Actinomycetes, and even methanotrophs. Given recurring detection of methane on the martian surface, evidence of a methane cycling community in an analogous environment is of particular interest. In this study we analyze the carbon isotope composition of bulk organic material as well as extracted lipids from the Lake Gilmore sediment cores at both a near-shore and mid-lake location. These analyses reveal very low accumulations of organic carbon, concentrated primarily in the gypsum-rich near-shore core. The near-shore sediments show a down-core decrease in abundance of organic carbon as well as depletion in the carbon isotope composition (δ13C) with depth. Bulk carbon did not exhibit the unique, highly depleted, diagnostic signature associated with methanotrophic biomass. Compound-specific isotope analysis (CSIA) of carbon in extracted methanotroph PFLAs can confirm the presence of a methane cycling metabolism at depth. Also, additional extractions have isolated lipids associated with lake-edge grasses. These analyses consider both the chain-length distribution and carbon CSIA of these lipids in order to understand the effect of terrestrial detritus on any preserved methanotroph carbon signal, given the very low amounts of microbial biomass found in lake cores. While the mineralogy does not suggest anaerobic conditions, further investigation includes extraction of archaeal lipids in order to identify the presence of any methanogenic community associated with the putative methanotrophic community.

  20. Retrieval of surface albedo over the Railroad Valley playa from AVIRIS measurements

    NASA Astrophysics Data System (ADS)

    Taylor, T.; O'Brien, D.; O'Dell, C. W.; kuze, A.

    2011-12-01

    High spatial resolution spectra, measured by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) in the 0.76, 1.6 and 2.0 micron bands, are used to retrieve albedo over a bright desert surface in support of the GOSAT vicarious calibration campaign. The albedo retrieval consists of a simple, linear least squares (LLS) fitting routine, coupled with a radiative transfer model. The retrieved albedos are used as inputs to a separate radiative transfer code used to model top of the atmosphere (TOA) radiances. These TOA radiances are then compared to those measured by GOSAT, thus providing the basis for the vicarious calibration of the GOSAT sensors.

  1. Comparison if seepage rates in playa lakes in grassland and cropland basins, Texas High Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two sorghum isolines, a wild type (BTx 623) and an erect leaf mutant line (ERL 20) isolated from the wild type were field grown in rectilinear arrays at low (25 plants m-2) and high (12 plants/m-2) densities with sub-surface drip irrigation in an effort to eliminate confounding drought effects. Cano...

  2. Controls of dust emission fluxes and wind erosion threshold on a wet playa

    NASA Astrophysics Data System (ADS)

    Wiggs, G.; King, J.; Thomas, D. S.; Washington, R.

    2012-12-01

    The control of dust emissions from crusted surfaces is both highly variable and difficult to measure directly. Seasonal changes in moisture availability, temperature, evaporation, surface roughness, and sediment supply result in a highly complex surface condition that remains to be fully described in the context of wind erosion potential. A highly intensive project on Sua Pan, Botswana using the PI-SWERL (portable wind tunnel) combined with surface measurements of crust and soil properties has led to a new understanding of the controls on wind erosion from these surfaces. The PI-SWERL is a highly portable wind tunnel that applies a wind shear to the surface using a motor-controlled rotating annular blade and measures resulting dust emissions with a DustTrak dust monitor. We undertook a sequence of tests with the PI-SWERL to obtain both the wind erosion threshold (using a slowly increasing shear velocity) and a dust emission flux (using a constant shear velocity) across a 12 km by 12 km grid across the pan surface. A total of just under 1000 wind tunnel tests and 2000 correlated measurements of a variety of surface properties including crust thickness, surface and subsurface soil moisture, shearing strength (shear vane), normal stress resistance (penetrometer), and surface roughness were conducted in August 2011. These results show that wind erosion potential is best described by measurements of normal stress resistance rather than shearing strength at low dust emission fluxes, but despite their frequent use in wind erosion studies of crusted surfaces neither metric provided a good explanation of higher dust emission fluxes. Surface soil moisture explained the most variation in both dust emissions and wind erosion threshold although much variation remains unexplained. Our results suggested that combining measurements of surface roughness, soil moisture, and crust thickness provided a reasonable explanation of wind erosion potential on the salt pan surface. As pan surfaces can exhibit a range of aerodynamic roughness lengths over three orders of magnitude the small-scale partition of wind stress could be considered. Surface soil moisture also had a very large range in which a relatively sharp threshold was found to increase dust emissions when combined with other surface factors. Although the role of surface moisture in dust emissions is understood it remains a very difficult (yet critical) parameter to measure and a call for more precise estimations of this metric is highly encouraged.

  3. Prokaryotic Diversity in Aran-Bidgol Salt Lake, the Largest Hypersaline Playa in Iran

    PubMed Central

    Makhdoumi-Kakhki, Ali; Amoozegar, Mohammad Ali; Kazemi, Bahram; Pašić, Lejla; Ventosa, Antonio

    2012-01-01

    Prokaryotic diversity in Aran-Bidgol salt lake, a thalasohaline lake in Iran, was studied by fluorescence in situ hybridization (FISH), cultivation techniques, denaturing gradient gel electrophoresis (DGGE) of PCR-amplified fragments of 16S rRNA genes and 16S rRNA gene clone library analysis. Viable counts obtained (2.5–4 × 106 cells mL−1) were similar to total cell abundance in the lake determined by DAPI direct count (3–4×107 cells mL−1). The proportion of Bacteria to Archaea in the community detectable by FISH was unexpectedly high and ranged between 1:3 and 1:2. We analyzed 101 archaeal isolates and found that most belonged to the genera Halorubrum (55%) and Haloarcula (18%). Eleven bacterial isolates obtained in pure culture were affiliated with the genera Salinibacter (18.7%), Salicola (18.7%) and Rhodovibrio (35.3%). Analysis of inserts of 100 clones from the eight 16S rRNA clone libraries constructed revealed 37 OTUs. The majority (63%) of these sequences were not related to any previously identified taxa. Within this sampling effort we most frequently retrieved phylotypes related to Halorhabdus (16% of archaeal sequences obtained) and Salinibacter (36% of bacterial sequences obtained). Other prokaryotic groups that were abundant included representatives of Haloquadratum, the anaerobic genera Halanaerobium and Halocella, purple sulfur bacteria of the genus Halorhodospira and Cyanobacteria. PMID:22185719

  4. 77 FR 50080 - Del Norte County Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-20

    ...The Del Norte County Resource Advisory Committee (RAC) will meet in Crescent City, California. The committee is authorized under the Secure Rural Schools and Community Self-Determination Act (Pub. L. 112-141) (the Act) and operates in compliance with the Federal Advisory Committee Act. The purpose of the committee is to improve collaborative relationships and to provide advice and......

  5. Síntesis: Resultados iniciales del Estudio Nacional de Ex

    Cancer.gov

    El 4 de noviembre de 2010, el Estudio Nacional de Exámenes de Pulmóndio a conocer resultados iniciales que indican que hubo 20% menos muertes por cáncer de pulmón entre los participantes del estudio evaluados con tomografía computarizada espiral de baja d

  6. Faculty Activity Analysis in the Universidad Tecnica Del Estado Campuses.

    ERIC Educational Resources Information Center

    Karadima, Oscar

    An analysis of academic activities of college faculty at the eight campuses of Chile's Universidad Tecnica del Estado was conducted. Activities were grouped into seven categories: direct teaching, indirect teaching, research, community services, faculty development, academic administration, and other activities. Following the narrative…

  7. Interdisciplinary Unit: La Isla del Encanto (The Enchanted Island).

    ERIC Educational Resources Information Center

    Ford-Guerrera, Rebecca

    This document presents a series of 14 lesson plans in an interdisciplinary Spanish unit on "La isla del encanto/The Enchanted Island." The materials were prepared for students in grades 5 or 6 who have had basic Spanish instruction in previous grades. The students should also be familiar with basic concepts in English such as math computation, map…

  8. Design, aerodynamics and autonomy of the DelFly.

    PubMed

    de Croon, G C H E; Groen, M A; De Wagter, C; Remes, B; Ruijsink, R; van Oudheusden, B W

    2012-06-01

    One of the major challenges in robotics is to develop a fly-like robot that can autonomously fly around in unknown environments. In this paper, we discuss the current state of the DelFly project, in which we follow a top-down approach to ever smaller and more autonomous ornithopters. The presented findings concerning the design, aerodynamics and autonomy of the DelFly illustrate some of the properties of the top-down approach, which allows the identification and resolution of issues that also play a role at smaller scales. A parametric variation of the wing stiffener layout produced a 5% more power-efficient wing. An experimental aerodynamic investigation revealed that this could be associated with an improved stiffness of the wing, while further providing evidence of the vortex development during the flap cycle. The presented experiments resulted in an improvement in the generated lift, allowing the inclusion of a yaw rate gyro, pressure sensor and microcontroller onboard the DelFly. The autonomy of the DelFly is expanded by achieving (1) an improved turning logic to obtain better vision-based obstacle avoidance performance in environments with varying texture and (2) successful onboard height control based on the pressure sensor. PMID:22617112

  9. Cosmogenic Radionuclides in the Campo Del Cielo Iron Meteorite

    NASA Technical Reports Server (NTRS)

    Liberman, R. G.; FernandezNiello, J. O.; Reedy, R. C.; Fifield, L. K.; diTada, M. L.

    2001-01-01

    Cosmogenic Be-10, Al-26, Cl-36, Ca-41, and Ni-59 were measured in the Campo del Cielo iron meteorite. Our results led us to conclude that the pre-atmospheric radius might have been approximately 2 m. Comparisons with other big bodies are also presented. Additional information is contained in the original extended abstract.

  10. 87. Paso Del Norte Hotel, 115117 South El Paso St., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    87. Paso Del Norte Hotel, 115-117 South El Paso St., south and east facades, west side of street - South El Paso Street Historic District, South El Paso, South Oregon & South Santa Fe Streets, El Paso, El Paso County, TX

  11. 89. Paso Del Norte Hotel, 115117 South El Paso St., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    89. Paso Del Norte Hotel, 115-117 South El Paso St., detail view of roof, west side of street - South El Paso Street Historic District, South El Paso, South Oregon & South Santa Fe Streets, El Paso, El Paso County, TX

  12. Cirugía de los trastornos del comportamiento: el estado del arte

    PubMed Central

    Yampolsky, Claudio; Bendersky, Damián

    2014-01-01

    Introducción: La cirugía de los trastornos del comportamiento (CTC) se está convirtiendo en un tratamiento más común desde el desarrollo de la neuromodulación. Métodos: Este artículo es una revisión no sistemática de la historia, indicaciones actuales, técnicas y blancos quirúrgicos de la CTC. Dividimos su historia en 3 eras: la primera comienza en los inicios de la psicocirugía y termina con el desarrollo de las tícnicas estereotácticas, cuando comienza la segunda era. Ésta se caracteriza por la realización de lesiones estereotácticas. Nos encontramos transitando la tercera era, que comienza cuando la estimulación cerebral profunda (ECP) comienza a ser usada en CTC. Resultados: A pesar de los errores graves cometidos en el pasado, hoy en día, la CTC está renaciendo. Los trastornos psiquiátricos que se más frecuentemente se tratan con cirugía son: depresión refractaria, trastorno obsesivo-compulsivo y síndrome de Tourette. Además, algunos pacientes con agresividad fueron tratados quirúrgicamente. Hay varios blancos estereotácticos descriptos para estos trastornos. La estimulación vagal puede ser usada también para depresión. Conclusión: Los resultados de la ECP en estos trastornos parecen alentadores. Sin embargo, se necesitan más estudios randomizados para establecer la efectividad de la CTC. Debe tenerse en cuenta que una apropiada selección de pacientes nos ayudará a realizar un procedimiento más seguro así como también a lograr mejores resultados quirúrgicos, conduciendo a la CTC a ser más aceptada por psiquiatras, pacientes y sus familias. Se necesita mayor investigación en varios temas como: fisiopatología de los trastornos del comportamiento, indicaciones de CTC y nuevos blancos quirúrgicos. PMID:25165612

  13. Del Mod at a Glance, Volume 3. 1973-1974 Annual Report for the Del Mod System.

    ERIC Educational Resources Information Center

    Bolig, John R.

    A synopsis of the 1973-74 annual report for the Del Mod System is presented. The activities described were conducted by the University of Delaware, Delaware State College, Delaware Technical and Community College, and the Department of Public Instruction. Activities of field agents, several local district projects, and individual teacher grants…

  14. Extensión del Formalismo de Orbitales de Defecto Cuántico al tratamiento del efecto Stark (SQDO).

    NASA Astrophysics Data System (ADS)

    Menéndez, J. M.; Martín, I.; Velasco, A. M.

    El estudio experimental de las interacciones de átomos Rydberg altamente excitados con campos eléctricos ha experimentado un creciente interés durante las dos últimas décadas debido, en gran medida, al desarrollo de nuevas técnicas para crear y estudiar átomos Rydberg en el laboratorio. Acompañando a estas nuevas técnicas experimentales, es necesario el desarrollo de modelos teóricos que nos permitan contrastar sus medidas y conocer mejor los fundamentos de los mismos. Desde el punto de vista teórico el conocimiento del desdoblamiento de los niveles energéticos de un átomo en función de la magnitud del campo eléctrico aplicado (lo que se conoce como mapa Stark) es el mejor punto de partida para la descripción del sistema y un prerrequisito fundamental para el cálculo de distintas propiedades atómicas en presencia del campo eléctrico tales como intensidades de transición, umbrales de ionización de campo eléctrico, tiempos de vida, posición y anchura de cruces evitados, etc. En este trabajo presentamos la adaptación del método de orbitales de defecto cuántico [1,2,3] al tratamiento del efecto Stark (SQDO) [4] y su aplicación al cálculo de los desdoblamientos energéticos y fuerzas de oscilador de estados Rydberg en los átomos de Li, Na y K. El propósito de este estudio es, por un lado, desarrollar métodos fiables para la determinación de propiedades atómicas en presencia de campos eléctricos y, por otro, mostrar la fiabilidad de las funciones de onda QDO en la descripción del efecto Stark en sistemas atómicos.

  15. Analisis del contenido curricular de los Documentos Normativos del Programa de Ciencias en el area de biologia para la escuela superior del sistema de educacion publica de Puerto Rico: 1993-2012

    NASA Astrophysics Data System (ADS)

    Davila Montanez, Melissa

    Esta investigacion de naturaleza cualitativa se ocupo de realizar un analisis de contenido documental de los Documentos Normativos del Programa de Ciencias en el area de biologia de la escuela superior del sistema de educacion publica de Puerto Rico del periodo 1993-2012. Los documentos analizados fueron: Guia Curricular, 1995; Marco Curricular, 2003; Estandares de Excelencia, 1996, 2000 y Estandares de Contenido y Expectativas de Grado, 2007. Se indago si hubo cambios en significados en los Componentes Estructurales: Naturaleza de la ciencia, Paradigmas para la ensenanza de la ciencia, Funcion del curriculo formal, Mision de la ensenanza de la ciencia; Contenidos, destrezas y competencias, Estrategias de ensenanza y Evaluacion/Assessment del aprendizaje. El analisis sugiere que no hubo cambios sustanciales en los significados de los Componentes Estructurales. Los documentos estudiados muestran mayormente caracteristicas similares, aunque los documentos mas recientes eran mas descriptivos, explicativos y especificos.

  16. Genomic Copy Number Variations in the Myelodysplastic Syndrome and Acute Myeloid Leukemia Patients with del(5q) and/or -7/del(7q).

    PubMed

    Zhang, Rui; Kim, Young-Mi; Wang, Xianfu; Li, Yan; Lu, Xianglan; Sternenberger, Andrea R; Li, Shibo; Lee, Ji-Yun

    2015-01-01

    The most common chromosomal abnormalities in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) are -5/del(5q) and -7/del(7q). When -5/del(5q) and -7/del(7q) coexist in patients, a poor prognosis is typically associated. Given that -5/del(5q) and/or -7/del(7q) often are accompanied with additional recurrent chromosomal alterations, genetic change(s) on the accompanying chromosome(s) other than chromosomes 5 and 7 may be important factor(s) affecting leukemogenesis and disease prognosis. Using an integrated analysis of karyotype, FISH and array CGH results in this study, we evaluated the smallest region of overlap (SRO) of chromosomes 5 and 7 as well as copy number alterations (CNAs) on the other chromosomes. Moreover, the relationship between the CNAs and del(5q) and -7/del(7q) was investigated by categorizing the cases into three groups based on the abnormalities of chromosomes 5 and 7 [group I: cases only with del(5q), group II: cases only with -7/del(7q) and group III: concurrent del(5q) and del(7q) cases]. The overlapping SRO of chromosome 5 from groups I and III was 5q31.1-33.1 and of chromosome 7 from groups II and III was 7q31.31-q36.1. A total of 318 CNAs were observed; ~ 78.3% of them were identified on chromosomes other than chromosomes 5 and 7, which were defined as 'other CNAs'. Group III was a distinctive group carrying the most high number (HN) CNAs, cryptic CNAs and 'other CNAs'. The loss of TP53 was highly associated with del(5q). The loss of ETV6 was specifically associated with group III. These CNAs or genes may play a secondary role in disease progression and should be further evaluated for their clinical significance and influence on therapeutic approaches in patients with MDS/AML carrying del(5q) and/or -7/del(7q) in large-scale, patient population study. PMID:26392809

  17. Genomic Copy Number Variations in the Myelodysplastic Syndrome and Acute Myeloid Leukemia Patients with del(5q) and/or -7/del(7q)

    PubMed Central

    Zhang, Rui; Kim, Young-Mi; Wang, Xianfu; Li, Yan; Lu, Xianglan; Sternenberger, Andrea R.; Li, Shibo; Lee, Ji-Yun

    2015-01-01

    The most common chromosomal abnormalities in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) are -5/del(5q) and -7/del(7q). When -5/del(5q) and -7/del(7q) coexist in patients, a poor prognosis is typically associated. Given that -5/del(5q) and/or -7/del(7q) often are accompanied with additional recurrent chromosomal alterations, genetic change(s) on the accompanying chromosome(s) other than chromosomes 5 and 7 may be important factor(s) affecting leukemogenesis and disease prognosis. Using an integrated analysis of karyotype, FISH and array CGH results in this study, we evaluated the smallest region of overlap (SRO) of chromosomes 5 and 7 as well as copy number alterations (CNAs) on the other chromosomes. Moreover, the relationship between the CNAs and del(5q) and -7/del(7q) was investigated by categorizing the cases into three groups based on the abnormalities of chromosomes 5 and 7 [group I: cases only with del(5q), group II: cases only with -7/del(7q) and group III: concurrent del(5q) and del(7q) cases]. The overlapping SRO of chromosome 5 from groups I and III was 5q31.1-33.1 and of chromosome 7 from groups II and III was 7q31.31-q36.1. A total of 318 CNAs were observed; ~ 78.3% of them were identified on chromosomes other than chromosomes 5 and 7, which were defined as 'other CNAs'. Group III was a distinctive group carrying the most high number (HN) CNAs, cryptic CNAs and 'other CNAs'. The loss of TP53 was highly associated with del(5q). The loss of ETV6 was specifically associated with group III. These CNAs or genes may play a secondary role in disease progression and should be further evaluated for their clinical significance and influence on therapeutic approaches in patients with MDS/AML carrying del(5q) and/or -7/del(7q) in large-scale, patient population study. PMID:26392809

  18. New records of fishes at Isla del Coco, Costa Rica

    USGS Publications Warehouse

    Garrison, V.H.

    1996-01-01

    Isla del Coco lies at 5 degrees 32'N latitude, 87 degrees 04'W longitude and is the sole peak of the Cocos Ridge exposed above sea level. This isolated island formed approximately 2 million years ago. It rises 575 m above the surface of the sea and covers 46 km2 (Castillo et aI., 1988). Five hundred km to the NNE is Costa Rica; 630 km SSW are the Galapagos Islands; 650 km to the E is Isla Malpelo, Colombia; and approximately 8,000 km W lie the Line Islands. Costa Rica claimed Isla del Coco in 1832 and declared it a National Park in 1978. The area of the park was increased to include the adjacent waters 5 km offshore in 1984 and 25 km offshore in 1991.

  19. A model of Nevado del Ruiz Volcano, Colombia

    NASA Astrophysics Data System (ADS)

    Williams, Stanley N.; Meyer, Hansjürgen

    A workshop was held at the Observatorio Vulcanologico de Colombia in Manizales, Colombia, March 28 to April 1, 1988, to review the accumulated data on the disastrous November 13, 1985, eruption and related activity of Nevado del Ruiz volcano (Figure 1). Approximately 30 scientists from eight countries presented data, developed a preliminary model, and addressed the future problems of Ruiz. The volcano (see Figure 2) erupted just prior to the meeting, covering the meeting site with 1-2 mm of ash.The workshop was convened by Stanley N. Williams (Louisiana State University, Baton Rouge) and Hansjürgen Meyer (Universidad del Valle, Cali, Colombia). A special volume of the Journal of Volcanology and Geothermal Research is planned for the papers and letters presented at the workshop, with some additional contributions. Publication is expected in mid-1989.

  20. El ``Aula del Cel'': astronomy approaching high school

    NASA Astrophysics Data System (ADS)

    Ortiz-Gil, A.; Gómez Collado, M.; Gallego Calvente, A. T.

    The “Aula del Cel” is a project carried out by the Astronomical Obsevatory of the University of Valencia, Spain. It offers high-school teachers a tool for teaching Astronomy to 10 to 17 year-old students. Different programs, experiments, and audiovisual presentations have been prepared by a team formed both by professional astronomers and teachers, and are offered in a format chosen to suit each particular age and curriculum group. Special sessions have been designed for students with special needs (for example blind or autistic children) in close contact with the pedagogical teams responsible for their education. Nearly three thousand students have already visited the “Aula del Cel” over the first six months that it has been offered to the school community.

  1. 2. COURSE OF THE LATERAL THROUGH DEL NORTHWEST MAR PARK. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. COURSE OF THE LATERAL THROUGH DEL NORTHWEST MAR PARK. - Highline Canal, Sand Creek Lateral, Beginning at intersection of Peoria Street & Highline Canal in Arapahoe County (City of Aurora), Sand Creek lateral Extends 15 miles Northerly through Araphoe County, City & County of Denver, & Adams County to its end point, approximately 1/4 mile Southest of intersectioin of D Street & Ninth Avenue in Adams County (Rocky Mountain Arsenal, Commerce City Vicinity), Commerce City, Adams County, CO

  2. 3. 1939 DROP STRUCTURE IN DEL MAR PARK SURMOUNTED BY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. 1939 DROP STRUCTURE IN DEL MAR PARK SURMOUNTED BY RECENT PEDESTRIAN BRIDGE. - Highline Canal, Sand Creek Lateral, Beginning at intersection of Peoria Street & Highline Canal in Arapahoe County (City of Aurora), Sand Creek lateral Extends 15 miles Northerly through Araphoe County, City & County of Denver, & Adams County to its end point, approximately 1/4 mile Southest of intersectioin of D Street & Ninth Avenue in Adams County (Rocky Mountain Arsenal, Commerce City Vicinity), Commerce City, Adams County, CO

  3. Solar adaptive optics at the Observatorio del Teide, Tenerife

    NASA Astrophysics Data System (ADS)

    Soltau, Dirk; Berkefeld, Thomas; Schmidt, Dirk; von der Lühe, Oskar

    2013-10-01

    Observing the Sun with high angular resolution is difficult because the turbulence in the atmosphere is strongest during day time. In this paper we describe the principles of solar adaptive optics exemplified by the two German solar telescopes VTT and GREGOR at the Observatorio del Teide. With theses systems we obtain near diffraction limited images of the Sun. Ways to overcome the limits of conventional AO by applying multiconjugate adaptive optics (MCAO) are shown.

  4. Determinacion de Caracteristicas Opticas del Telescopio OAN150

    NASA Astrophysics Data System (ADS)

    Galan, M. J.; Cobos, F. J.

    1987-05-01

    En el Observatorio de Calar Alto, en Almería, España, está ubicado un telescopio de 15O-cms de diámetro -construído por REOSC- perteneciente al Observatorio Astronómico Nacional, con sede en Madrid, España. La infraestructura técnica del OAN ha sido tradicionalmente débil y actualmente se está haciendo un esfuerzo por fortalecerla. Existe una información muy limitada del telescopio en general; de su óptica en particular se conocían los valores de los parámetros principales pero sin saber si éstos corresponden a valores teóricos ó de construcción. Por ello se consideró necesario iniciar una investigación para conocer en detalle los valores reales de las componentes ópticas del telescopio, obteniéndose algunos resultados de interés. El primario del telescopio OANl5O es aproximadamente F/3 y el siste ma en su conjunto es F/8.2, con su sistema corrector de campo. En términos generales, la imagen es satisfactoria en todo el campo y, sin sistema corrector, la imagen axial también es buena. En un futuro muy cercano se piensa diseñar instrumentación adicional para este telescopio. Conocer con mayor precisión sus características puede ser de gran utilidad para tal fin, pues se efectúan los cálculos considerando conjuntamente al telescopio y al instrumento.

  5. Los plaguicidas y la contaminacion del medio ambiente Venezolano

    USGS Publications Warehouse

    Stickel, L.F.; Stickel, W.H.

    1972-01-01

    RESUMEN DE RECOMENDACIONES Recomendaciones para el Programa de Investigacion: 1. Establecer un sistema de muestreo biologico para detectar los niveles tendencias de los productos quimicos toxicos en un peque?o numero de si tios representativos. 2. Mantener continua vigilancia de la contaminacion ambiental, mediante la seleccion acertadamente dirigida de las zonas afectadas y de las fuentes de contaminacion. 3. Realizar estudios acerca de las poblaciones de animales silvestres, y del exito de los procesos reproductivos de las especies o grupos clayes de animales que se consideran mas gravemente afectados. 4. Preparar recomendaciones para una accion gubernamental de proteccion al hombre, a la fauna silvestre y al medio ambiente. Recomendaciones para la Accion Administrativa: 1. Establecer limites a la tolerancia de los residuos de plaguicidas en los alimentos. Constituye una medida clave para disminuir la contaminacion ambiental. 2. Establecer normas de calidad del agua para las corrientes, represas, la gos y otros cuerpos. Es la segunda medida clave para reducir la contaminacion del ambiente 3. Exigir un tratamiento adecuado de los efluentes industriales, especialmente antes de que se construyan las nuevas plantas. 4. Exigir a los agricultores que en el uso de plaguicidas sigan los consejos tecnicos autorizados y negar a los vendedores el derecho a recomendar productos por su cuenta. 5. Tomar medidas para recoger y eliminar los recipientes y sobrantes de los plaguicidas.

  6. Estudio multifrecuencia del medio interestelar cercano a HD 192281

    NASA Astrophysics Data System (ADS)

    Arnal, E. M.; Cappa, C. E.; Cichowolski, S.; Pineault, S.; St-Louis, N.

    Una de las causas que modifica la estructura y dinámica del medio interestelar es la acción que los vientos de las estrellas de gran masa ejercen sobre el mismo. En este trabajo, mediante el uso de datos interferométricos obtenidos en la banda de radio en la transición de λ˜21-cm del hidrógeno neutro y de imágenes de la emisión de continuo en las bandas de 408 y 1420 MHz, de imágenes HIRES del satélite IRAS en 60 y 100μm, y de observaciones de continuo obtenidas con radiotelescopios de disco simple en 2695, 4850 y 8350 MHz se ha realizado un estudio multifrecuencia de los efectos que los vientos estelares de HD 192281, una estrella de tipo espectral O5,Vn((f))p, han tenido sobre el medio interestelar que rodea a la misma.

  7. Field Measurements of Respiratory Del13CO2 and Photodegradation

    NASA Astrophysics Data System (ADS)

    van Asperen, H.; Sabbatini, S.; Nicolini, G.; Warneke, T.; Papale, D.; Notholt, J.

    2014-12-01

    Carbon decomposition dynamics have been studied in a variety of ecosystems and its variation can mostly be explained in terms of environmental variables (e.g. temperature and precipitation). However, carbon dynamics in arid, water limited regions have shown to be very different and are still largely unknown. Several studies have indicated the importance of photodegradation, the direct breakdown of organic matter by sunlight, in these arid regions. A FTIR (Fourier Transform Infrared Spectrometer) was set up to continuously measure concentrations of CO2, CH4, N2O, CO as well as del13C in CO2. The FTIR was connected to 2 different flux measurement systems: a Flux Gradient system and 2 flux chambers, providing a continuous data set of gas concentrations and biosphere-atmosphere gas fluxes at different heights and scales. Field measurements showed photodegradation induced carbon fluxes. Also, respiratory del13CO2 was determined by use of Keeling plots, and was determined to vary between -25‰ and -21‰. A clear diurnal pattern in respiratory del13CO2 was found, suggesting either different (dominant) respiratory processes between day and night or the effect of diffusive fractionation.

  8. Modeling Visibility in the EL Paso del Norte Region

    NASA Astrophysics Data System (ADS)

    Fitzgerald, R. M.; Medina, R.; DuBois, D. W.; Novlan, D.

    2013-12-01

    Poor visibility is a subject of growing public concern throughout the U.S, and an active area of research. Its societal impacts in air quality, aviation transport and traffic are significant. Aerosols play a fundamental role in the attenuation of solar radiation, and also affect visibility. The scattering and extinction coefficients of aerosol particles in the Paso del Norte Region have been calculated using the T- matrix model in conjunction with a laser particle counter. Inter-comparison of the model's results of the scattering and absorption coefficients against the corresponding data from a Photoacustic Extinctiometer instrument (which measures in-situ absorption and scattering coefficients of aerosol particles) shows excellent agreement. In addition, the volume-weighted method is used to determine the composite index of refraction which is representative of the aerosols for the Paso del Norte Airshed to obtain information of the type of aerosol particles present in the Airshed. The Single Scattering Albedo has also been retrieved using our methodology to obtain further insight into the type of aerosols present on a given day. Finally, the Koschmieder equation has been used to calculate the visual range or visibility, and was correlated with the PM2.5 and PM10 particle concentration present in the Airshed. Our methodology will allow a better understanding of the size and type of aerosol particles that are most detrimental to the visibility for the Paso del Norte Region.

  9. Modeling visibility in the Paso del Norte (PDN) Region

    NASA Astrophysics Data System (ADS)

    Medina Calderon, Richard

    Poor visibility is a subject of growing public concern throughout the U.S, and an active area of research. Its societal impacts on air quality, aviation transport and traffic are significant. Aerosols play a fundamental role in the attenuation of solar radiation, and also affect visibility. The scattering and extinction coefficients of aerosol particles in the Paso del Norte Region have been calculated using the T- matrix model in conjunction with a laser particle counter. Inter-comparison of the model's results of the scattering and absorption coefficients against the corresponding data from a Photoacustic extinctiometer instrument (which measures in-situ absorption and scattering coefficients of aerosol particles) shows excellent agreement. In addition, the volume-weighted method is used to determine the composite index of refraction which is representative of the aerosols for the Paso del Norte Region to obtain information of the type of aerosol particles present in the Region. The Single Scattering Albedo has also been retrieved using this methodology to obtain further insight into the type of aerosols present on a given day. Finally, the Koschmieder equation has been used to calculate the visual range or visibility, and was correlated with the PM2.5 and PM10 particle concentration present in the Region. Our methodology will allow a better understanding of the size and type of aerosol particles that are most detrimental to the visibility for the Paso Del Norte Region.

  10. Estrategia innovadora enfocada en parejas del mismo sexo para disminuir la infección del VIH en hombres Latinos

    PubMed Central

    Martinez, Omar; Wu, Elwin; Sandfort, Theo; Shultz, Andrew Z.; Capote, Jonathan; Chávez, Silvia; Moya, Eva; Dodge, Brian; Morales, Gabriel; Porras, Antonio; Ovejero, Hugo

    2014-01-01

    Resumen El VIH es un problema de salud importante dentro de la comunidad latina de los Estados Unidos. Gracias a los esfuerzos de prevención, los niveles de contagio entre los latinos se han mantenido estables por más de una década. Sin embargo, esta población sigue siendo afectada a niveles muy altos, en particular entre hombres que tienen sexo con hombres (HSH), de origen latino y que hablan principalmente el idioma español. Existen varios factores que contribuyen a la transmisión del VIH entre esta población, como son: el uso de drogas; la violencia dentro de la pareja; la presencia de infecciones de transmisión sexual; relaciones sexuales sin protección, dentro y fuera de la pareja; el evadir la búsqueda de recursos (prueba y tratamiento adecuado) por temor a ser discriminado o por su estatus migratorio; la escasez de recursos económicos o estado de pobreza y los patrones relacionados a la migración. En particular, Investigaciones Epidemiológicas de Comportamientos han determinado: cómo algunas dinámicas en parejas están directamente asociadas a los comportamientos sexuales de riesgos. En consecuencia, es necesaria mayor investigación para identificar esas dinámicas, y a su vez, realizar intervenciones dirigidas a la reducción de conductas de riesgo enfocadas en parejas de hombres del mismo sexo. En este escrito, se describe la importancia del uso de las relaciones de pareja como estrategia en la reducción de la trasmisión del VIH/SIDA en HSH de origen latino y que hablan principalmente el idioma español en los Estados Unidos. PMID:25580466

  11. The 2012 Reactivation of Nevado del Ruiz Volcano, Colombia

    NASA Astrophysics Data System (ADS)

    Ordoñez, M.; Lopez, C.; Cortes, G. P.; Londoño, J.; Battaglia, M.

    2012-12-01

    Nevado Del Ruiz volcano is most known for its tragic November 13, 1985 explosive event, when a small eruption produced an enormous lahar that buried and destroyed the town of Armero in Tolima, causing an estimated 25,000 deaths. Similar but less deadly incidents occurred in 1595 and 1845, again where a small explosive eruption was followed by a large lahar. Other minor explosive events occurred in 1805, 1828-9, and 1989. The Armero tragedy was a major factor in the establishment of a volcano monitoring program in Colombia. The network monitoring Nevado del Ruiz volcano has dramatically improved since the 1985 eruption and now includes geodetic, geophysical, geochemical and visual monitoring. The activity of Nevado Del Ruiz between 1985 and 1991 saw significant increases in seismicity and significant gas emissions with the main eruptive events of November 13, 1985 and September 1st, 1989. The volcano became seismically active again in 1995 and 2002, whit an increase in seismicity, without any gas emission or eruption. In October 2010 the volcano entered in a new phase of unrest with increased seismicity (HB events), deformation and gas emissions, likely associated with a new magma intrusion. In February, 2012 the volcano had a new and significant increase in seismicity (VT-LP), followed in May and June 2012 by small phreatic and phreato-magmatic eruption. This eruptive activity is still ongoing. Deformation measurements at Nevado Del Ruiz volcano have been carried out since just after the tragic eruption of the 13th of November 1985. In 2007 seven new electronic tilt meters were set up to monitor the deformation. Significant uplift was measured from August 2007 to October 2010, for a total cumulative value of more than 500 microradians. From the end of 2011 to July 2012, moderate changes of uplift were detected for a total of 70 microradians. The analysis of these deformation data shows a pattern of surface displacement associated with an intrusion of new magma

  12. Comportamiento del Helio en estrellas químicamente peculiares

    NASA Astrophysics Data System (ADS)

    Malaroda, S. M.; López García, Z.; Leone, F.; Catalano, F.

    Las estrellas químicamente peculiares (CP) se caracterizan por tener deficiencias y sobreabundancias de algunos elementos químicos de hasta 106 veces la abundancia solar. Además presentan variaciones en las líneas espectrales. Se piensa que ello se debe a que los campos magnéticos presentes en este tipo de estrellas son principalmente dipolares, con un eje de simetría diferente del eje de rotación. La distribución de los elementos sobreabundantes y deficientes no es homogénea sobre la superficie estelar y las variaciones observadas serían una consecuencia directa de la rotación estelar. Entre los elementos con abundancia anómala se encuentra el Helio, cuyas líneas tienen intensidades que no son consistentes con una abundancia normal, que no puede ser determinada del modo usual, o sea, considerando una atmósfera con composición solar. Con el fin de determinar la abundancia de este elemento, se inició un estudio de estrellas anómalas de Helio, Hew y He strong. Además se determinarán las abundancias de otros elementos anómalos como ser el Si, Cr, Mg, Mn y Fe. Las mismas se determinan del modo tradicional, o sea: a) medida de los anchos equivalentes de las líneas de los distintos elementos analizados; b) adopción de la temperatura efectiva, gravedad y abundancia del Helio; c) cálculo del modelo de atmósfera d) comparación con las observaciones y reinicio de un proceso iterativo hasta lograr un acuerdo entre todos los parámetros analizados. Las observaciones se llevaron a cabo en el Complejo Astronómico El Leoncito. Se observaron setenta y ocho estrellas anómalas de Helio. En este momento se está procediendo a calcular las abundancias correspondientes a los distintos elementos químicos. Para ello se hace uso de los modelos de Kurucz, ATLAS9. Los cálculos NLTE de las líneas de Helio se llevan a cabo con el programa MULTI y se compararán con los realizados con el programa WIDTH9 de Kurucz (LTE), con el objeto de resaltar la importancia de

  13. Perk Ablation Ameliorates Myelination in S63del-Charcot–Marie–Tooth 1B Neuropathy

    PubMed Central

    Musner, Nicolò; Sidoli, Mariapaola; Zambroni, Desireè; Del Carro, Ubaldo; Ungaro, Daniela; D’Antonio, Maurizio; Feltri, Maria L.

    2016-01-01

    In peripheral nerves, P0 glycoprotein accounts for more than 20% of myelin protein content. P0 is synthesized by Schwann cells, processed in the endoplasmic reticulum (ER) and enters the secretory pathway. However, the mutant P0 with S63 deleted (P0S63del) accumulates in the ER lumen and induces a demyelinating neuropathy in Charcot–Marie–Tooth disease type 1B (CMT1B)–S63del mice. Accumulation of P0S63del in the ER triggers a persistent unfolded protein response. Protein kinase RNA-like endoplasmic reticulum kinase (PERK) is an ER stress sensor that phosphorylates eukaryotic initiation factor 2 alpha (eIF2alpha) in order to attenuate protein synthesis. We have shown that increasing phosphophorylated-eIF2alpha (P-eIF2alpha) is a potent therapeutic strategy, improving myelination and motor function in S63del mice. Here, we explore the converse experiment: Perk haploinsufficiency reduces P-eIF2alpha in S63del nerves as expected, but surprisingly, ameliorates, rather than worsens S63del neuropathy. Motor performance and myelin abnormalities improved in S63del//Perk+/− compared with S63del mice. These data suggest that mechanisms other than protein translation might be involved in CMT1B/S63del neuropathy. In addition, Perk deficiency in other cells may contribute to demyelination in a non–Schwann-cell autonomous manner. PMID:27095827

  14. Perk Ablation Ameliorates Myelination in S63del-Charcot-Marie-Tooth 1B Neuropathy.

    PubMed

    Musner, Nicolò; Sidoli, Mariapaola; Zambroni, Desireè; Del Carro, Ubaldo; Ungaro, Daniela; D'Antonio, Maurizio; Feltri, Maria L; Wrabetz, Lawrence

    2016-04-01

    In peripheral nerves, P0 glycoprotein accounts for more than 20% of myelin protein content. P0 is synthesized by Schwann cells, processed in the endoplasmic reticulum (ER) and enters the secretory pathway. However, the mutant P0 with S63 deleted (P0S63del) accumulates in the ER lumen and induces a demyelinating neuropathy in Charcot-Marie-Tooth disease type 1B (CMT1B)-S63del mice. Accumulation of P0S63del in the ER triggers a persistent unfolded protein response. Protein kinase RNA-like endoplasmic reticulum kinase (PERK) is an ER stress sensor that phosphorylates eukaryotic initiation factor 2 alpha (eIF2alpha) in order to attenuate protein synthesis. We have shown that increasing phosphophorylated-eIF2alpha (P-eIF2alpha) is a potent therapeutic strategy, improving myelination and motor function in S63del mice. Here, we explore the converse experiment:Perkhaploinsufficiency reduces P-eIF2alpha in S63del nerves as expected, but surprisingly, ameliorates, rather than worsens S63del neuropathy. Motor performance and myelin abnormalities improved in S63del//Perk+/- compared with S63del mice. These data suggest that mechanisms other than protein translation might be involved in CMT1B/S63del neuropathy. In addition,Perkdeficiency in other cells may contribute to demyelination in a non-Schwann-cell autonomous manner. PMID:27095827

  15. Screening for 185delAG in the Ashkenazim.

    PubMed Central

    Richards, C S; Ward, P A; Roa, B B; Friedman, L C; Boyd, A A; Kuenzli, G; Dunn, J K; Plon, S E

    1997-01-01

    A study was initiated to assess interest, educational effectiveness, and implications of genetic testing for the common BRCA1 mutation, 185delAG, in the Ashkenazim. Of 333 individuals who attended group sessions, 309 (92%) participated in the study. Participants were categorized as having negative family history (67%), positive family history (defined, by a relaxed criterion, as one first-degree relative or two second-degree relatives with breast [premenopausal] or ovarian cancer) (22%), positive personal history (7%), and both positive personal history and positive family history (4%). Group education was effective, as shown by the improvement in participant scores from pre- to posteducation tests. For the 289 individuals (94%) who requested testing, the major reasons included concern for their own risk, concern for the risk of their children, and desire to learn about surveillance options. The most common reason given by participants who declined testing was concern about health insurance. Six participants found to be heterozygous for the 185delAG mutation received results and were offered genetic counseling. Participants had consented for additional testing without receiving results and were screened for the 6174delT mutation in BRCA2, and seven were found to be positive. All identified carriers reported at least one first- or second-degree relative with a history of breast or ovarian cancer, although they did not all meet our study criteria for positive family history. Given these outcomes, we conclude that screening for breast and ovarian cancer susceptibility is most appropriate for individuals with a positive personal or positive family cancer history. We propose a guideline for future studies designed to identify individuals who may benefit from genetic testing for inherited breast and ovarian cancer. Images Figure 1 PMID:9150156

  16. Optical photometry and spectroscopy of Nova Del 2013

    NASA Astrophysics Data System (ADS)

    Tomov, T.; Ilkiewicz, K.; Swierczynski, E.; Belcheva, M.; Dimitrov, D.

    2013-08-01

    We report optical BV photometry and spectroscopy of Nova Del 2013, carried out between August 14.88 UT and August 15.08 UT. Using a 60 cm Cassegrain telescope at the Nicolaus Copernicus University Observatory (Torun, Poland) we estimated the V brightness of the Nova to be 6.31+/-0.02 mag and 6.18+/-0.03 mag on Aug. 14.94 UT and Aug. 15.02 UT respectively. HD 194113 (F2, V=8.00 mag) was used as a comparison star.

  17. Stray-light measurements at the Observatorio del Teide

    NASA Astrophysics Data System (ADS)

    Martinez Pillet, V.; Ruiz Cobo, B.; Vázquez, M.

    1990-09-01

    A new procedure to separate the instrumental and atmospheric components of stray light is presented. It is based on the dependence of the aureole's atmospheric component on the air mass and is applied to measurements taken with the Vacuum Newton Telescope (VNT) at the Observatorio del Teide (Tenerife). The resulting instrumental part is independent of the air mass. The variation of both components with wavelength is also studied. The instrumental component shows no dependence on wavelength, in contrast to the atmospheric one which is greater in the blue than in the red. It is concluded that observations with air masses larger than two will probably be strongly affected by stray light.

  18. Stray-light measurements at the Observatorio del Teide

    NASA Astrophysics Data System (ADS)

    Martinez Pillet, V.; Ruiz Cobo, B.; Vazquez, M.

    1990-02-01

    A new procedure to separate the instrumental and atmospheric components of stray light is presented. It is based on the dependence of the aureole's atmospheric component on the air mass and is applied to measurements taken with the Vacuum Newton Telescope (VNT) at the Observatorio del Teide (Tenerife). The resulting instrumental part is independent of the air mass. The variation of both components with wavelength is also studied. The instrumental component shows no dependence on wavelength, in contrast to the atmospheric one which is greater in the blue than in the red. It is concluded that observations with air masses larger than two will probably be strongly affected by stray light.

  19. Medical ethnobotany of the Teribes of Bocas del Toro, Panama.

    PubMed

    Gupta, M P; Solís, P N; Calderón, A I; Guionneau-Sinclair, F; Guinneau-Sinclair, F; Correa, M; Galdames, C; Guerra, C; Espinosa, A; Alvenda, G I; Robles, G; Ocampo, R

    2005-01-15

    Ethnomedical uses of 108 medicinal plant species, belonging to 52 families, 89 genera, used by the Teribe Amerindians of Bocas del Toro Province in Panama, along with their socio-cultural practices are reported here. The methods of administration of the herbal remedies, the plant parts used, their families and local names are also documented. The recorded medicinal plants were used mainly for fever, various type of pain and inflammation. The potential value of 26 plants and their traditional uses was elucidated through literature search. PMID:15619557

  20. Instantánea del cáncer de riñón

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de riñón; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  1. 33 CFR 162.200 - Marina del Rey, Calif.; restricted area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Marina del Rey, Calif.; restricted area. 162.200 Section 162.200 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.200 Marina del Rey, Calif.; restricted area. (a)...

  2. Instantánea del cáncer de seno (mama)

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de seno (mama); así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  3. Instantánea del cáncer de tiroides

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de tiroides; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  4. Instantánea del cáncer de vejiga

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de vejiga; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  5. Instantánea del cáncer de pulmón

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de pulmón; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  6. Instantánea del cáncer de páncreas

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de páncreas; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  7. [Recommendations to improve the scientific communication process in the Revista Médica del IMSS].

    PubMed

    Álvarez, Ivón

    2016-01-01

    In order to improve the position of the Revista Médica del Instituto Mexicano del Seguro Social among the different journals, in this editorial we enumerate a series of recommendations to ameliorate the practices of the different actors who participate in the scientific communication process of this journal. PMID:26820191

  8. Instantánea del cáncer de cuello uterino

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de cuello uterino; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  9. 33 CFR 162.200 - Marina del Rey, Calif.; restricted area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Marina del Rey, Calif.; restricted area. 162.200 Section 162.200 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.200 Marina del Rey, Calif.; restricted area. (a)...

  10. 62. R.L.T., photographer November 1, 1934 DEL NORTE COUNTY, SECTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. R.L.T., photographer November 1, 1934 DEL NORTE COUNTY, SECTION D, HIGHWAY 1. REDWOOD CLEARING ON EXISTING LINE, 1-DN-71-A #26, R.L.T. 11-1-34. Stamped office copy. - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

  11. 63. G.F.H., photographer July 30, 1932 DEL NORTE COUNTY, SECTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    63. G.F.H., photographer July 30, 1932 DEL NORTE COUNTY, SECTION A, HIGHWAY 1. 1-DN A #124, STA. 164=00 SHOWING DRAINAGE CONDITIONS, G.F.H., 7-30-32. - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

  12. 33 CFR 334.110 - Delaware Bay off Cape Henlopen, Del.; naval restricted area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., Del.; naval restricted area. 334.110 Section 334.110 Navigation and Navigable Waters CORPS OF....110 Delaware Bay off Cape Henlopen, Del.; naval restricted area. (a) The area. Beginning at a point on... regulations in this section shall be enforced by the Commandant, Fourth Naval District, and such agencies...

  13. 33 CFR 334.110 - Delaware Bay off Cape Henlopen, Del.; naval restricted area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., Del.; naval restricted area. 334.110 Section 334.110 Navigation and Navigable Waters CORPS OF....110 Delaware Bay off Cape Henlopen, Del.; naval restricted area. (a) The area. Beginning at a point on... regulations in this section shall be enforced by the Commandant, Fourth Naval District, and such agencies...

  14. Statistical Comparisons of Pre and Post Del Mod Data, Final Report, Volume V.

    ERIC Educational Resources Information Center

    Bolig, John R.; Wall, Charles A.

    This is one of five volumes prepared to describe various aspects of the Del Mod System. This report attempts to compare baseline data gathered in 1970-71 to post experimental data gathered in 1975-76. Sections include analyses of achievement test scores, research conducted under the auspices of the Del Mod System, and a follow-up study of…

  15. 66. Photographer unknown March 1920'S DEL NORTE COUNTY, SECTION B, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    66. Photographer unknown March 1920'S DEL NORTE COUNTY, SECTION B, HIGHWAY 1. 1-DN 1-B #9, CORDUROY DETOUR INTO CRESCENT CITY, 2-2 (3?). Stamped office copy. - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

  16. 33 CFR 162.200 - Marina del Rey, Calif.; restricted area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Marina del Rey, Calif.; restricted area. 162.200 Section 162.200 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.200 Marina del Rey, Calif.; restricted area. (a)...

  17. Instantánea del cáncer de esófago

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de esófago; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  18. Instantánea del cáncer de estómago

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de estómago; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  19. Instantánea del cáncer de ovario

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de ovario; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  20. Instantánea del cáncer de endometrio

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de endometrio; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  1. Instantánea del cáncer de próstata

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de próstata; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  2. Late Quaternary vegetation and climate of southern Tierra del Fuego

    NASA Astrophysics Data System (ADS)

    Heusser, Calvin J.

    1989-05-01

    Vegetation and climate over approximately the past 13,000 yr are reconstructed from fossil pollen in a 9.4-m mire section at Caleta Róbalo on Beagle Channel, Isla Navarino (54°56'S, 67°38'W), southern Tierra del Fuego. Fifty surface samples reflecting modern pollen dispersal serve to interpret the record. Chronologically controlled by nine radiocarbon dates, fossil pollen assemblages are: Empetrum-Gramineae- Gunnera-Tubuliflorae (zone 3b, 13,000-11,850 yr B.P.), Gramineae- Empetrum-assorted minor taxa (zone 3a, 11,850-10,000 yr B.P.), Nothofagus-Gramineae-Tubuliflorae-Polypodiaceae (zone 2, 10,000-5000 yr B.P.), Nothofagus-Empetrum (zone 1b, 5000-3000 yr B.P.), and Empetrum-Nothofagus (zone 1a, 3000-0 yr B.P.). Assemblages show tundra under a cold, dry climate (zone 3), followed by open woodland (zone 2), as conditions became warmer and less dry, and later, with greater humidity and lower temperatures, by closed forest and the spread of mires (zone 1). Comparisons drawn with records from Antarctica, New Zealand, Tasmania, and the subantarctic islands demonstrate broadly uniform conditions in the circumpolar Southern Hemisphere. The influences of continental and maritime antarctic air masses were apparently considerable in Tierra del Fuego during cold late-glacial time, whereas Holocene climate was largely regulated by interplay between maritime polar and maritime tropical air.

  3. Efecto del Programa de Entrenamiento “Manejo del Dolor” en la Documentación de Enfermería en el Expediente Electrónico

    PubMed Central

    Monsiváis, María Guadalupe Moreno; Guzmán, Ma. Guadalupe Interial; Flores, Paz Francisco Sauceda; Arreola, Leticia Vázquez

    2012-01-01

    Resumen En el presente trabajo se muestra la importancia de entrenar al personal de enfermería para mejorar la documentación en el expediente electrónico. Se eligió el manejo del dolor por ser un área prioritaria; una alta proporción de pacientes en período post operatorio cursa con dolor, por lo tanto, la documentación debe ser útil para la toma de decisiones clínicas. Se implementó un programa de entrenamiento denominado “Manejo del Dolor” dirigido al personal de enfermería. Se utilizó la tecnología de la información como herramienta para fortalecer el conocimiento con base en la revisión sistemática de la literatura; el personal de enfermería participante seleccionó la mejor evidencia; posteriormente se trabajó en la transferencia de este conocimiento a la práctica a través del diseño de un protocolo para el manejo del dolor. Se concluye que el conocimiento del manejo del dolor es fundamental para que enfermería documente con mayor precisión sus intervenciones. PMID:24199106

  4. Disruption of cytokeratin-8 interaction with F508del-CFTR corrects its functional defect

    PubMed Central

    Colas, Julien; Faure, Grazyna; Saussereau, Emilie; Trudel, Stéphanie; Rabeh, Wael M.; Bitam, Sara; Guerrera, Ida Chiara; Fritsch, Janine; Sermet-Gaudelus, Isabelle; Davezac, Noëlie; Brouillard, Franck; Lukacs, Gergely L.; Herrmann, Harald; Ollero, Mario; Edelman, Aleksander

    2012-01-01

    We have previously reported an increased expression of cytokeratins 8/18 (K8/K18) in cells expressing the F508del mutation of cystic fibrosis transmembrane conductance regulator (CFTR). This is associated with increased colocalization of CFTR and K18 in the vicinity of the endoplasmic reticulum, although this is reversed by treating cells with curcumin, resulting in the rescue of F508del-CFTR. In the present work, we hypothesized that (i) the K8/K18 network may interact physically with CFTR, and that (ii) this interaction may modify CFTR function. CFTR was immunoprecipitated from HeLa cells transfected with either wild-type (WT) CFTR or F508del-CFTR. Precipitates were subjected to 2D-gel electrophoresis and differential spots identified by mass spectrometry. K8 and K18 were found significantly increased in F508del-CFTR precipitates. Using surface plasmon resonance, we demonstrate that K8, but not K18, binds directly and preferentially to the F508del over the WT human NBD1 (nucleotide-binding domain-1). In vivo K8 interaction with F508del-CFTR was confirmed by proximity ligation assay in HeLa cells and in primary cultures of human respiratory epithelial cells. Ablation of K8 expression by siRNA in F508del-expressing HeLa cells led to the recovery of CFTR-dependent iodide efflux. Moreover, F508del-expressing mice topically treated with K8-siRNA showed restored nasal potential difference, equivalent to that of WT mice. These results show that disruption of F508del-CFTR and K8 interaction leads to the correction of the F508del-CFTR processing defect, suggesting a novel potential therapeutic target in CF. PMID:22038833

  5. Instantánea de los cánceres de cerebro y del sistema nervioso central

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre los cánceres de cerebro y del sistema nervioso central; así como ejemplos de actividades del NCI y adelantos en la investigación de estos tipos de cáncer.

  6. Assessing Glacier Hazards At Ghiacciaio Del Belvedere, Macugnaga, Italian Alps

    NASA Astrophysics Data System (ADS)

    Haeberli, W.; Chiarle, M.; Mortara, G.; Mazza, A.

    The uppermost section of the Valle Anzasca behind and above the community of Macugnaga in the Italian Alps is one of the most spectacular high-mountain land- scapes in Europe, with gigantic rock walls and numerous steep hanging glaciers. Its main glacier, Ghiacciaio del Belvedere at the foot of the huge Monte Rosa east face, is a heavily debris-covered glacier flowing on a thick sediment bed. Problems with floods, avalanches and debris flows from this ice body have been known for extended time periods. Most recently, however, the evolution of this highly dynamic environ- ment has become more dramatic. An outburst of Lago delle Locce, an ice-dammed lake at the confluenec of the tributary Ghiacciaio delle Locce with Ghiacciaio del Belvedere, caused heavy damage in 1979 and necessitated site investigation and con- struction work to be done for flood protection. The intermittent glacier growth ten- dency in the 1970es induced strong bulging of the glacier surface and, in places, caused the glacier tongue to override historical morains and to destroy newly-grown forest stands. A surge-type flow acceleration started in the lower parts of the Monte- Rosa east face during summer 2000, leading to strong crevassing and deformation of Ghiacciaio del Belvedere and extreme bulging of its orographic right margin. High water pressure and accelerated movement lasted into winter 2001/2002: the ice now started overriding the LIA moraine near Rifugio Zamboni of the CAI. In addition but rather independently, a most active detachment zone for rock falls and debris flows developed for several years now in the east face of Monte Rosa, somewhat more to the south of the accelerated glacier movement and at an altitude where relatively warm permafrost must be expected. Besides the scientific interest in these phenomena, the growing hazard potential to the local infrastructure must be considered seriously. Es- pecially potentials for the destabilization of large rock and ice masses in the

  7. [History of Instituto Nacional de Salud Ocupacional del Peru].

    PubMed

    Cossio-Brazzan, Juan M

    2012-06-01

    In Peru, the industry's development has made economic improvements but at the same time, it has had a major impact on the health of the workers; for that reason, it was necessary to generate control mechanisms. So, in 1940 it was created the Departmento de Higiene Industrial, which in 1956 was changed to Instituto de Salud Ocupacional, but it was deactivated in 1994. However, in 2001 it reappeared into the Ministerio de Salud organizational structure with the name of Instituto de Salud Ocupacional "Alberto Hurtado Abadía". Actually, it is the Centro Nacional de Salud Ocupacional y Protección del Ambiente para la Salud (CENSOPAS), organ of the Instituto Nacional de Salud which continues working in synergy with other institutions and sectors, making research to protect the health of exposed persons (workers and community) to contamination and risks associated with economic activities. PMID:22858781

  8. Energy integrated farm system: Del Valle Hog Farm

    SciTech Connect

    Not Available

    1984-01-01

    The Del Valle Hog Farm, a Texas hog farm with grain crops, is designed to conserve energy through methane generation, alcohol production, and efficient use of electrical energy. The integrated energy concepts to be demonstrated are: methane generation from swine manure to produce electricity and heat for alcohol fermentation and distillation and to produce hot water for heating the digester reactors and the hog feeding pens; and alcohol production from milo and distillation of 170 proof alcohol by use of methane and generated electricity. Specific energy technologies to be implemented are: anaerobic digester; gas compressors to store methane for peak demands; engine generator powered by methane; waste-heat exchanger on engine generator to produce hot water; continuous-process alcohol facility to produce 24 gal/day; and crop management.

  9. Circular structures of Bajada del Diablo (Argentina): geophysical signatures

    NASA Astrophysics Data System (ADS)

    Prezzi, C. B.; Orgeira, M. J.; Martinez, O.; Acevedo, R. D.; Ponce, F.; Goldmann, G.; Magneres, I.; Rabassa, J.

    2016-02-01

    Bajada del Diablo is located in the Northern Patagonian Massif, Chubut, Argentina. The study area includes several circular structures found in Miocene olivine basalts of the Quiñelaf Eruptive Complex and in the Late Pliocene/Early Pleistocene Pampa Sastre conglomerates. An impact origin has been proposed for these circular structures. With the aim of further investigate the proposed impact origin, topographic, gravimetric, magnetic, resistivity, paleomagnetic and electromagnetic surveys in two circular structures ("8" and "G") located in Pampa Sastre conglomerates and in basalts of the Quiñelaf Eruptive Complex were carried out. The new geophysical results support the hypothesis of an impact origin. However, the confirmation of such an origin through the findings of shock metamorphism evidences and/or the recovery of meteorites remains elusive.

  10. Renewable energy load assessment for Boquillas Del Carmen Coahuila, Mexico

    SciTech Connect

    Foster, R.

    1995-08-01

    This report outlines the estimates that were made in 1992 of the potential load requirements for Boquillas del Carmen, a small Mexican village on the northern border of the state of Coahuila, Mexico near Big Bend National Park in southern Texas. The study was made to help determine the possibility that village might be electrified by solar or wind energy. Various estimates of are given of the potential load based on estimates ranging from basic use of lights, radio, television, and small household appliances to microwave ovens, refrigerators, and direct evaporative coolers. The low-energy consumption case was estimated to be at 23.0 kWh/month per residence per month, and the high-energy consumption case (with cooling) was 140.7 kWh/month per residence. On average, the typical residence is occupied by five individuals.

  11. Circular structures of Bajada del Diablo (Argentina): geophysical signatures

    NASA Astrophysics Data System (ADS)

    Prezzi, C. B.; Orgeira, M. J.; Martinez, O.; Acevedo, R. D.; Ponce, F.; Goldmann, G.; Magneres, I.; Rabassa, J.

    2016-05-01

    Bajada del Diablo is located in the Northern Patagonian Massif, Chubut, Argentina. The study area includes several circular structures found in Miocene olivine basalts of the Quiñelaf Eruptive Complex and in the Late Pliocene/Early Pleistocene Pampa Sastre conglomerates. An impact origin has been proposed for these circular structures. With the aim of further investigate the proposed impact origin, topographic, gravimetric, magnetic, resistivity, palaeomagnetic and electromagnetic surveys in two circular structures (`8' and `G') located in Pampa Sastre conglomerates and in basalts of the Quiñelaf Eruptive Complex were carried out. The new geophysical results support the hypothesis of an impact origin. However, the confirmation of such an origin through the findings of shock metamorphism evidences and/or the recovery of meteorites remains elusive.

  12. Phytoseiid mites (Acari: Phytoseiidae) from Patagonia and Tierra del Fuego.

    PubMed

    Ferragut, Francisco; Navia, Denise

    2015-01-01

    Predatory phytoseiid mites have been intensively studied and surveyed in the last decades because of their economic importance as biocontrol agents of agricultural pests. However, many regions of the world remain unexplored and the diversity of the family worldwide is still fragmentary. Up to date no phytoseiid species have been collected in the southernmost part of the Earth down to latitude 45º S. In this study Phytoseiidae were sampled from native vegetation in southern Argentina and Chile in the regions of Patagonia and Tierra del Fuego Island. Thirteen species were collected, five of which were previously described and eight, Chileseius australis n. sp., Neoseiulus mapuche n. sp., Typhlodromips valdivianus n. sp., T. fissuratus n. sp., Amblyseius grandiporus n. sp., A. caliginosus n. sp., Typhlodromus (Anthoseius) anomalos n. sp. and Metaseiulus parabrevicollis n. sp. are proposed as new to science and are described and diagnosed. PMID:26250248

  13. Ozone studies in the Paso del Norte region

    NASA Astrophysics Data System (ADS)

    Becerra-Davila, Fernando

    The Paso del Norte region forms the largest contiguous bi-national conglomerate on the US-Mexico border. With a combined population of around 2 million inhabitants, the Paso del Norte region is isolated, more than 500 km away from the nearest urban area of comparable size, thus making it an ideal location for air quality studies of an isolated urban environment. The meteorological conditions leading to a high ozone episode in this region, such as the historical ozone episode of June 2006, are analyzed. It is well known that stagnation and minimal winds, high temperatures, and pressure ridges over the region are conducive to high ozone episodes. In addition, the planetary boundary height is studied to understand its impact on high ozone episodes. Several studies report that ground level ozone non-attainment regulations could be caused not only by local emissions, but also by atmospheric transport. In this work the atmospheric advection of pollutants into the region is analyzed using HYSPLIT backward trajectories. Furthermore, a novel backward trajectory clustering technique is implemented for the summer of 2006. The "ozone weekend effect" (OWE) is a phenomenon by which in some geographical regions ambient ozone concentrations tend to be higher on weekends than on weekdays, despite the lower emissions of ozone precursors during those days. The observed local OWE has never previously been studied in terms of the photolysis rates of four of the main ozone precursors. In this research a novel method that allows the calculation of actinic fluxes, photolysis frequencies and photolysis rates with a high degree of accuracy and reliability has been developed. This method utilizes a combination of the experimental data available for this region in conjunction with a radiative transfer model (TUV model). Three weekend-weekday cases during summers 2006, 2009 and 2010 are studied in this work. In this research, the photolysis impact on the local OWE is studied. The results

  14. Clean cities: Award winning coalition -- Paso del Norte

    SciTech Connect

    O'Connor, K.

    1999-10-25

    Designated the 41st Clean Cities coalition in November 1995, the Paso del Norte Clean Cities Coalition (PDNCCC) is the first in the country to gain international participation. Spanning the US-Mexico border; the coalition includes stakeholders from El Paso, Texas; Ciudad Juarez, Mexico; and Las Cruces, New Mexico. PDNCCC developed a comprehensive plan to jump-start its program place, alternative fuel vehicles (AFVs) on the road, and eliminate barriers inhibiting alternative fuel market growth. PDNCC raised more than $2.3 million for alternative fuel activities and clean air initiatives in less than 26 months. In 1998, the US Department of Energy (DOE) recognized that PDNCCC accomplishment with its Rainmaker Award for leveraging the most funds from outside sources. PDNCCC is proud of its efforts to drive the alternative fuels and AFV market in the El Paso/Juarez region.

  15. Spatially Controlled Fe Isotope Variations at Torres del Paine

    NASA Astrophysics Data System (ADS)

    Gajos, N.; Lundstrom, C.

    2013-12-01

    Recent advances in mass-spectrometry have identified systematic trends of non-traditional stable isotope variation in igneous rocks with differentiation index. We present new Fe isotope data for the Torres del Paine igneous complex in southern Chile. The multi-composition pluton consists of a 1 km vertical exposure of homogenous granite overlying a contemporaneous and possibly cogenetic 0.5 km mafic gabbro suite. Whereas previous isotopic investigations do little to address variations across important magmatic contacts, this study focuses on a first-of-its-kind spatially dependent non-traditional stable isotope investigation of an igneous pluton. Samples were collected at Torres del Paine in spatially significant transects, focusing on major contacts between country rock, granite and mafic units. Results collected by bracketed double spike MC-ICP-MS (2s precision of ×0.03) show an increase in δ56Fe towards the high silica margins of the pluton with values as high as δ56Fe 0.36. Additionally, the data show a decrease in δ56Fe toward the mafic center of the pluton with δ56Fe values ranging from δ56Fe -0.05 to 0.18. Samples collected on the contact between the granite and mafic complex show intermediate values of δ56Fe= 0.18(×) 0.03. Country rock samples in contact with granite show an isotopically light signature of δ56Fe=0.04 (×) 0.03. Analysis of 50 samples in total show a trend of increasing δ56Fe with SiO2 content. The process responsible for Fe isotope variations remains debated but is suggested to reflect four mechanisms: (1) crustal assimilation, (2) fractional crystallization, (3) late stage fluid exsolution [1] and (4) thermal migration [3]. Preliminary results show that mechanisms #1 and #2 would produce isotopic signatures opposite of those seen at Torres del Paine and other plutonic rocks. Isotopically light Torres country rock samples reveal that assimilation of rocks would not produce the isotopically heavy granites seen at Torres. Based on

  16. DEL-1 restrains osteoclastogenesis and inhibits inflammatory bone loss in nonhuman primates.

    PubMed

    Shin, Jieun; Maekawa, Tomoki; Abe, Toshiharu; Hajishengallis, Evlambia; Hosur, Kavita; Pyaram, Kalyani; Mitroulis, Ioannis; Chavakis, Triantafyllos; Hajishengallis, George

    2015-09-30

    DEL-1 (developmental endothelial locus-1) is an endothelial cell-secreted protein that regulates LFA-1 (lymphocyte function-associated antigen-1) integrin-dependent leukocyte recruitment and inflammation in various tissues. We identified a novel regulatory mechanism of DEL-1 in osteoclast biology. Specifically, we showed that DEL-1 is expressed by human and mouse osteoclasts and regulates their differentiation and resorptive function. Mechanistically, DEL-1 inhibited the expression of NFATc1, a master regulator of osteoclastogenesis, in a Mac-1 integrin-dependent manner. In vivo mechanistic analysis has dissociated the anti-inflammatory from the anti-bone-resorptive action of DEL-1 and identified structural components thereof mediating these distinct functions. Locally administered human DEL-1 blocked inflammatory periodontal bone loss in nonhuman primates-a relevant model of human periodontitis. The ability of DEL-1 to regulate both upstream (inflammatory cell recruitment) and downstream (osteoclastogenesis) events that lead to inflammatory bone loss paves the way to a new class of endogenous therapeutics for treating periodontitis and perhaps other inflammatory disorders. PMID:26424570

  17. Deglacial palaeoclimate at Puerto del Hambre, subantarctic Patagonia, Chile

    NASA Astrophysics Data System (ADS)

    Heusser, Calvin J.; Heusser, Linda E.; Lowell, Thomas V.; Moreira M., Andrés; Moreira M., Simón

    2000-02-01

    The primary objective of this study is to further substantiate multistep climatic forcing of late-glacial vegetation in southern South America. A secondary objective is to establish the age of deglaciation in Estrecho de Magallanes-Bahía Inútil. Pollen assemblages at 2-cm intervals in a core of the mire at Puerto del Hambre (53°3621S, 70°5553W) provide the basis for reconstructing the vegetation and a detailed account of palaeoclimate in subantarctic Patagonia. Chronology over the 262-cm length of core is regulated by 20 AMS radiocarbon dates between 14 455 and 10 089 14C yr BP. Of 13 pollen assemblage zones, the earliest representing the Oldest Dryas chronozone (14 455-13 000 14C yr BP) records impoverished steppe with decreasing frequencies and loss of southern beech (Nothofagus). Successive 100-yr-long episodes of grass/herbs and of heath (Empetrum/Ericaceae) before 14 000 14C yr BP infer deglacial successional communities under a climate of increased continentality prior to the establishment of grass-dominated steppe. The Bølling-Allerød (13 000-11 000 14C yr BP) is characterised by mesic grassland under moderating climate that with abrupt change to heath dominance after 12 000 14C yr BP was warmer and not as humid. At the time of the Younger Dryas (11 000-10 000 14C yr BP), grass steppe expanded with a return of colder, more humid climate. Later, with gradual warming, communities were invaded by southern beech. The Puerto del Hambre record parallels multistep, deglacial palaeoclimatic sequences reported elsewhere in the Southern Andes and at Taylor Dome in Antarctica. Deglaciation of Estrecho de Magallanes-Bahía Inútil is dated close to 14 455 14C yr BP, invalidating earlier dates of between 15 800 and 16 590 14C yr BP.

  18. [Epidemiology of dog bite lesions in Tierra del Fuego, Argentina].

    PubMed

    Zanini, Fabián; Padinger, Patricia; Elissondo, María C; Pérez, Héctor

    2008-01-01

    The coexistence between man and dog has resulted in mutual benefits during thousands of years, nevertheless some problems have recently arisen where bite injuries have an important role. The aim of this work was to describe the epidemiological characteristics of dog bite lesions which occurred during a year in Tierra del Fuego. A descriptive observational, transversal study of patients who were admitted with dog bite injuries to clinic and pediatric emergency services of hospitals and health centers was carried out between 3/1/05 and 3/1/06. A total of 382 records were made. The children group represents 49.5%. The group between 5 and 9 year-old was the most affected (44.4%; IC95% 37.2-51.8). In the adult group, that between 15 and 24 year-old was the most affected (29.5%; IC95% 23.2-36.5). More lesions were registered in men (57.6%) than in women (42.4%) (chi2 = 8.6, p = 0.003). During spring and summer months, 56.5% of the lesions were registered. A 72.8% of the incidents occurred on the public highway. Dogs of big size were responsible of 49.7% (IC95% 44.6-54.9) of the injuries. The 89.8% of the incidents were caused by another person's dog. Of the lesions, 55.8% (IC95% 50.6-60.8) were registered in lower extremities and 11% (IC95% 8.1-14.7) in head and neck. These data show that dog bite lesions affect the health and impact in the quality of life of the population of Tierra del Fuego, Argentina. PMID:18416313

  19. Spatial shell structure of the novas DQ Her and HR Del

    SciTech Connect

    Pilyogin, L.S.

    1986-03-01

    This paper considers the formation of the spatial shell structure of the novas DQ Her (1934) and HR Del (1967). It is shown that the existence of polar caps is due to the influence of the second component of the system on the angular distribution of the mass shell depth of the mainshell. The ratio of the mass shell depth in the equatorial ring and in the polar caps is 1.13 for DQ Her and 2.7 for HR Del. The ratio of the maximal densities in the equatorial ring and the polar caps is of order 3 for DQ Her and of order 70 for HR Del.

  20. General nonextremal rotating charged Gödel black holes in minimal five-dimensional gauged supergravity.

    PubMed

    Wu, Shuang-Qing

    2008-03-28

    I present the general exact solutions for nonextremal rotating charged black holes in the Gödel universe of five-dimensional minimal supergravity theory. They are uniquely characterized by four nontrivial parameters: namely, the mass m, the charge q, the Kerr equal rotation parameter a, and the Gödel parameter j. I calculate the conserved energy, angular momenta, and charge for the solutions and show that they completely satisfy the first law of black hole thermodynamics. I also study the symmetry and separability of the Hamilton-Jacobi and the massive Klein-Gordon equations in these Einstein-Maxwell-Chern-Simons-Gödel black hole backgrounds. PMID:18517852

  1. General Nonextremal Rotating Charged Gödel Black Holes in Minimal Five-Dimensional Gauged Supergravity

    NASA Astrophysics Data System (ADS)

    Wu, Shuang-Qing

    2008-03-01

    I present the general exact solutions for nonextremal rotating charged black holes in the Gödel universe of five-dimensional minimal supergravity theory. They are uniquely characterized by four nontrivial parameters: namely, the mass m, the charge q, the Kerr equal rotation parameter a, and the Gödel parameter j. I calculate the conserved energy, angular momenta, and charge for the solutions and show that they completely satisfy the first law of black hole thermodynamics. I also study the symmetry and separability of the Hamilton-Jacobi and the massive Klein-Gordon equations in these Einstein-Maxwell-Chern-Simons-Gödel black hole backgrounds.

  2. Resultados del relevamiento de HI en el Cielo Austral: 3. Relevamiento de Nubes de Alta Velocidad

    NASA Astrophysics Data System (ADS)

    Morras, R.; Bajaja, E.; Arnal, E. M.; Pöppel, W. G. L.

    Los resultados del relevamiento de HI del Hemisferio Austral fueron reprocesados con el fin de incrementar su sensibilidad. Así, se utilizó esta nueva base de datos con el fin de obtener un nuevo relevamiento de Nubes de Alta Velocidad en el cielo austral. El ruido r.m.s. alcanzado es de 0.015-0.020 K, con una resolución espectral de 8 km/seg. El cubrimiento espacial del relevamiento mejora en un factor 16 al realizado por Bajaja et al (1985).

  3. HAER DEL,3MILF.V,2 (sheet 1 of 4) Mispillion Lighthouse, South ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    HAER DEL,3-MILF.V,2- (sheet 1 of 4) - Mispillion Lighthouse, South bank of Mispillion River at its confluence with Delaware River at northeast end of County Road 203, 7 miles east of Milford, Milford, Sussex County, DE

  4. HAER DEL,3MILF.V,2 (sheet 2 of 4) Mispillion Lighthouse, South ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    HAER DEL,3-MILF.V,2- (sheet 2 of 4) - Mispillion Lighthouse, South bank of Mispillion River at its confluence with Delaware River at northeast end of County Road 203, 7 miles east of Milford, Milford, Sussex County, DE

  5. HAER DEL,3MILF.V,2 (sheet 3 of 4) Mispillion Lighthouse, South ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    HAER DEL,3-MILF.V,2- (sheet 3 of 4) - Mispillion Lighthouse, South bank of Mispillion River at its confluence with Delaware River at northeast end of County Road 203, 7 miles east of Milford, Milford, Sussex County, DE

  6. HAER DEL,3MILF.V,2 (sheet 4 of 4) Mispillion Lighthouse, South ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    HAER DEL,3-MILF.V,2- (sheet 4 of 4) - Mispillion Lighthouse, South bank of Mispillion River at its confluence with Delaware River at northeast end of County Road 203, 7 miles east of Milford, Milford, Sussex County, DE

  7. [Progress in InDel as a new generation of genetic marker].

    PubMed

    Sun, Kuan; Zhang, Su-Hua; Zhu, Ru-Xin; Zhao, Shu-Min; Li, Cheng-Tao

    2013-04-01

    As forensic DNA typing experienced three generations of genetic marker researching stage, short tandem repeat (STR) has been widely used in forensic identification as a mature tool. Further exploration of the human genome led to the discovery of polymorphism markers of single nucleotide polymorphism (SNP) and Insertion/Deletion (InDel). InDel, which combines the desirable characteristics of previous genetic markers as a new type of genetic marker, has got extensive concern in fields like medical molecular biology and forensic biology. This paper generally reviews the history of research and the corresponding results of InDel along the line of time axis as well as the different aims of these research focusing on the progress in the multiple amplification system with several InDel as the genetic marker (autosomal or X chromosome) in forensic biology and anthropology. Finally, the direction of research in this field and the problems to be solved have been put forward. PMID:23930511

  8. Three cases of dup(10p)/del(10q) syndrome resulting from maternal pericentric inversion.

    PubMed

    Kulharya, A S; Schneider, N R; Wilson, G N

    1993-11-01

    Two families and 3 patients with dup(10p)/del(10q) syndrome segregating from a maternal pericentric inversion are described, including a stillborn female with Potter sequence and multicystic renal dysplasia. Comparison of 32 dup(10p) patients to 11 del(10)(q25) patients emphasized dolichocephaly, wide sutures, frontal bossing, micrognathia, and renal defects as distinguishing characteristics of the dup(10p) syndrome. The 3 new and 6 previously reported dup(10p)/del(10q) patients had several manifestations in common with the dup(10p) and del(10q) syndromes, but were more typical of dup(10p) syndrome with respect to all 5 distinguishing characters. PMID:8279477

  9. 90. Paso Del Norte Hotel, 115117 South El Paso St.,east ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    90. Paso Del Norte Hotel, 115-117 South El Paso St.,east facade, west side of street - South El Paso Street Historic District, South El Paso, South Oregon & South Santa Fe Streets, El Paso, El Paso County, TX

  10. The extracellular matrix protein Del1 induces apoptosis via its epidermal growth factor motif.

    PubMed

    Kitano, Hisataka; Kokubun, Shinichiro; Hidai, Chiaki

    2010-03-19

    Mouse Del1 is an extracellular matrix protein mainly expressed in the developing embryo. Del1 has three EGF motifs and two discoidin domains. The second EGF motif reportedly contains an RGD sequence that binds to integrin receptors. Here, we provide evidence that Del1 protein induces cell death in vitro. Chromatin condensation and DNA laddering were observed, suggestive of apoptosis. The results of analysis using the TUNEL method and annexin V staining were also consistent with apoptosis. The apoptosis-inducing activity of Del1 could be mapped to the third EGF motif, which fitted the consensus sequence CX(D/N)XXXX(F/Y)XCXC, wherein the aspartic acid residue (D) could be beta-hydroxylated. As little as twenty-five picomolar of recombinant E3 could induce apoptosis. PMID:20171188

  11. Impact of Observing Parameters on 17 Nights with Nova Del 2013 (Abstract)

    NASA Astrophysics Data System (ADS)

    Green, W. L.

    2014-12-01

    (Abstract only) Nova Del 2013 (V339 Del) was reported in Astronomer’s Telegram No. 5279 (PNV 20233073+2046041) on 2013 August 14. On the following day, the University of Colorado, Boulder, granted our observing request for use of the R3000-5000 spectrograph attached to their 60-cm telescope. The planning, operational approach, analysis techniques, results, issues, and operational conclusions for data taken from 15 August through 2 September are reported here.

  12. Defining the defect in F508 del CFTR: a soluble problem?

    PubMed

    Deber, Charles M; Cheung, Joanne C; Rath, Arianna

    2008-01-01

    Previously reported crystal structures of CFTR F508 del-NBD1 were determined in the presence of solubilizing mutations. In this issue of Chemistry & Biology, Pissarra et al. (2008) show that partial rescue of the trafficking and gating defects of full-length CFTR occurs in vivo upon recapitulation of the solubilizing F494N/Q637R or F428S/F494N/Q637R substitutions in cis with F508 del. PMID:18215767

  13. RASTREO DEL CANCER COLORRECTAL CONOCIMIENTO Y ACTITUD DE LA POBLACION

    PubMed Central

    CASAL, ENRIQUE R.; VELAZQUEZ, ELIZABETH N.; MEJIA, RAUL M.; CUNEO, ALDO; PEREZ-STABLE, ELISEO J.

    2014-01-01

    Resumen El rastreo de cáncer colorrectal (CCR) cuenta con fuertes evidencias en su favor. Datos preliminares indican que a pesar de ello no se lleva a cabo con la frecuencia adecuada. Se intenta aquí determinar, dentro de un Sistema de Salud que cuenta con los recursos necesarios, los elementos que facilitan o generan barreras para concretar esta práctica preventiva, cuántos individuos lo ponen en práctica y qué predice esta conducta. Se realizó una encuesta telefónica a los afiliados de una Obra Social de empleados de la Universidad de Buenos Aires, de los que 132 completaron el cuestionario (tasa de respuesta 70%). Los elementos considerados facilitadores del rastreo obtuvieron respuestas afirmativas en el 64 a 97%, mientras que los que definían barreras un 11 a 27%. En este último grupo, una categoría diferenciada la constituía el miedo a los efectos adversos: 39%, y el sentimiento de vergüenza relacionado con los procedimientos: 30%. Un 33% de los encuestados tenían hecho un método de rastreo, mayoritariamente de sangre oculta (27), sigmoideoscopía (11) y colonoscopía (20). Una mayoría afirmó que “se haría el procedimiento si el médico se lo recomendara” (95%), o “no se lo haría excepto que su médico se lo aconseje” (87%). Contestar afirmativamente que “los médicos hacen lo mejor para los pacientes” se asoció con haberse hecho un método de rastreo de CCR, OR 1.55 (IC 95%: 1.02-2.37) p: 0.04. El grupo de individuos estudiado parece bien predispuesto para el rastreo del CCR, la recomendación médica sería aquí un determinante prominente para ponerlo en práctica. PMID:19414294

  14. Developmental endothelial locus-1 (Del-1) is a homeostatic factor in the central nervous system limiting neuroinflammation and demyelination

    PubMed Central

    Neuwirth, Ales; Economopoulou, Matina; Chatzigeorgiou, Antonios; Chung, Kyoung-Jin; Bittner, Stefan; Lee, Seung-Hwan; Langer, Harald; Samus, Maryna; Kim, Hyesoon; Cho, Geum-Sil; Ziemssen, Tjalf; Bdeir, Khalil; Chavakis, Emmanouil; Koh, Jae-Young; Boon, Louis; Hosur, Kavita; Bornstein, Stefan R.; Meuth, Sven G.; Hajishengallis, George; Chavakis, Triantafyllos

    2014-01-01

    Inflammation in the central nervous system (CNS) and disruption of its immune privilege are major contributors to the pathogenesis of multiple sclerosis (MS) and of its rodent counterpart, experimental autoimmune encephalomyelitis (EAE). We have previously identified developmental endothelial locus-1 (Del-1) as an endogenous anti-inflammatory factor, which inhibits integrin-dependent leukocyte adhesion. Here we show that Del-1 contributes to the immune privilege status of the CNS. Intriguingly, Del-1 expression decreased in chronic active MS lesions and in the inflamed CNS in the course of EAE. Del-1-deficiency was associated with increased EAE severity, accompanied by increased demyelination and axonal loss. As compared to control mice, Del-1−/− mice displayed enhanced disruption of the blood brain barrier and increased infiltration of neutrophil granulocytes in the spinal cord in the course of EAE, accompanied by elevated levels of inflammatory cytokines, including IL-17. The augmented levels of IL-17 in Del-1-deficiency derived predominantly from infiltrated CD8+ T cells. Increased EAE severity and neutrophil infiltration due to Del-1-deficiency was reversed in mice lacking both Del-1 and IL-17-receptor, indicating a crucial role for the IL-17/neutrophil inflammatory axis in EAE pathogenesis in Del-1−/− mice. Strikingly, systemic administration of Del-1-Fc ameliorated clinical relapse in relapsing-remitting EAE. Therefore, Del-1 is an endogenous homeostatic factor in the CNS protecting from neuroinflammation and demyelination. Our findings provide mechanistic underpinnings for the previous implication of Del-1 as a candidate MS susceptibility gene and suggest that Del-1-centered therapeutic approaches may be beneficial in neuroinflammatory and demyelinating disorders. PMID:25385367

  15. Unravelling druggable signalling networks that control F508del-CFTR proteostasis.

    PubMed

    Hegde, Ramanath Narayana; Parashuraman, Seetharaman; Iorio, Francesco; Ciciriello, Fabiana; Capuani, Fabrizio; Carissimo, Annamaria; Carrella, Diego; Belcastro, Vincenzo; Subramanian, Advait; Bounti, Laura; Persico, Maria; Carlile, Graeme; Galietta, Luis; Thomas, David Y; Di Bernardo, Diego; Luini, Alberto

    2015-01-01

    Cystic fibrosis (CF) is caused by mutations in CF transmembrane conductance regulator (CFTR). The most frequent mutation (F508del-CFTR) results in altered proteostasis, that is, in the misfolding and intracellular degradation of the protein. The F508del-CFTR proteostasis machinery and its homeostatic regulation are well studied, while the question whether 'classical' signalling pathways and phosphorylation cascades might control proteostasis remains barely explored. Here, we have unravelled signalling cascades acting selectively on the F508del-CFTR folding-trafficking defects by analysing the mechanisms of action of F508del-CFTR proteostasis regulator drugs through an approach based on transcriptional profiling followed by deconvolution of their gene signatures. Targeting multiple components of these signalling pathways resulted in potent and specific correction of F508del-CFTR proteostasis and in synergy with pharmacochaperones. These results provide new insights into the physiology of cellular proteostasis and a rational basis for developing effective pharmacological correctors of the F508del-CFTR defect. PMID:26701908

  16. Unravelling druggable signalling networks that control F508del-CFTR proteostasis

    PubMed Central

    Hegde, Ramanath Narayana; Parashuraman, Seetharaman; Capuani, Fabrizio; Carissimo, Annamaria; Carrella, Diego; Belcastro, Vincenzo; Subramanian, Advait; Bounti, Laura; Persico, Maria; Carlile, Graeme; Galietta, Luis; Thomas, David Y; Di Bernardo, Diego; Luini, Alberto

    2015-01-01

    Cystic fibrosis (CF) is caused by mutations in CF transmembrane conductance regulator (CFTR). The most frequent mutation (F508del-CFTR) results in altered proteostasis, that is, in the misfolding and intracellular degradation of the protein. The F508del-CFTR proteostasis machinery and its homeostatic regulation are well studied, while the question whether ‘classical’ signalling pathways and phosphorylation cascades might control proteostasis remains barely explored. Here, we have unravelled signalling cascades acting selectively on the F508del-CFTR folding-trafficking defects by analysing the mechanisms of action of F508del-CFTR proteostasis regulator drugs through an approach based on transcriptional profiling followed by deconvolution of their gene signatures. Targeting multiple components of these signalling pathways resulted in potent and specific correction of F508del-CFTR proteostasis and in synergy with pharmacochaperones. These results provide new insights into the physiology of cellular proteostasis and a rational basis for developing effective pharmacological correctors of the F508del-CFTR defect. DOI: http://dx.doi.org/10.7554/eLife.10365.001 PMID:26701908

  17. CHEK2 c.1100delC allele is rarely identified in Greek breast cancer cases.

    PubMed

    Apostolou, Paraskevi; Fostira, Florentia; Papamentzelopoulou, Myrto; Michelli, Maria; Panopoulos, Christos; Fountzilas, George; Konstantopoulou, Irene; Voutsinas, Gerassimos E; Yannoukakos, Drakoulis

    2015-04-01

    The CHEK2 gene encodes a protein kinase that plays a crucial role in maintenance of genomic integrity and the DNA repair mechanism. CHEK2 germline mutations are associated with increased risk of breast cancer and other malignancies. From a clinical perspective, the most significant mutation identified is the c.1100delC mutation, which is associated with an approximately 25% lifetime breast cancer risk. The distribution of this mutation shows wide geographical variation; it is more prevalent in the Northern European countries and less common, or even absent, in Southern Europe. In order to estimate the frequency of the CHEK2 c.1100delC mutation in Greek breast cancer patients, we genotyped 2,449 patients (2,408 females and 41 males), which was the largest series ever tested for c.1100delC. The mean age of female and male breast cancer diagnosis was 49 and 59 years, respectively. All patients had previously tested negative for the Greek BRCA1 founder and recurrent mutations. The CHEK2 c.1100delC mutation was detected in 0.16% (4 of 2,408) of females, all of whom were diagnosed with breast cancer before the age of 50 years. Only one c.1100delC carrier was reported with breast cancer family history. The present study indicates that the CHEK2 c.1100delC mutation does not contribute substantially to hereditary breast cancer in patients of Greek descent. PMID:25835597

  18. Breast tumors from CHEK2 1100delC-mutation carriers: genomic landscape and clinical implications

    PubMed Central

    2011-01-01

    Introduction Checkpoint kinase 2 (CHEK2) is a moderate penetrance breast cancer risk gene, whose truncating mutation 1100delC increases the risk about twofold. We investigated gene copy-number aberrations and gene-expression profiles that are typical for breast tumors of CHEK2 1100delC-mutation carriers. Methods In total, 126 breast tumor tissue specimens including 32 samples from patients carrying CHEK2 1100delC were studied in array-comparative genomic hybridization (aCGH) and gene-expression (GEX) experiments. After dimensionality reduction with CGHregions R package, CHEK2 1100delC-associated regions in the aCGH data were detected by the Wilcoxon rank-sum test. The linear model was fitted to GEX data with R package limma. Genes whose expression levels were associated with CHEK2 1100delC mutation were detected by the bayesian method. Results We discovered four lost and three gained CHEK2 1100delC-related loci. These include losses of 1p13.3-31.3, 8p21.1-2, 8p23.1-2, and 17p12-13.1 as well as gains of 12q13.11-3, 16p13.3, and 19p13.3. Twenty-eight genes located on these regions showed differential expression between CHEK2 1100delC and other tumors, nominating them as candidates for CHEK2 1100delC-associated tumor-progression drivers. These included CLCA1 on 1p22 as well as CALCOCO1, SBEM, and LRP1 on 12q13. Altogether, 188 genes were differentially expressed between CHEK2 1100delC and other tumors. Of these, 144 had elevated and 44, reduced expression levels. Our results suggest the WNT pathway as a driver of tumorigenesis in breast tumors of CHEK2 1100delC-mutation carriers and a role for the olfactory receptor protein family in cancer progression. Differences in the expression of the 188 CHEK2 1100delC-associated genes divided breast tumor samples from three independent datasets into two groups that differed in their relapse-free survival time. Conclusions We have shown that copy-number aberrations of certain genomic regions are associated with CHEK2 mutation

  19. ``Campo del Cielo'' Meteorites: Astronomical Heritage and Cultural Colonialism

    NASA Astrophysics Data System (ADS)

    López, Alejandro Martín; Altman, Agustina

    2012-09-01

    In the province of Chaco, Argentina, there is a very unique dispersion of metallic meteorites called ``Campo del Cielo''. One of the meteoric fragments of this dispersion, the meteorite called ``El Chaco'', consisting of 37 tons, is the second heaviest in the world. These meteorites are of great importance to the worldview of the Moqoit, aboriginal people that inhabit this region. For the local Creole population the meteorites are also relevant, that's why they have being cited in numerous documents and reports since the colonial period. During the first months of 2012, two Argentine artists and the Artistic Director of the German contemporary art exhibition called dOCUMENTA (13) tried to move ``El Chaco'' meteorite to Germany in order to exhibit it as an artistic object. Due to the fact that moving the meteorite could have a negative impact according to the Moqoit cosmology and that they were not able to participate in the decision they begun a manifestation against the movement of El Chaco. The opposition made by aboriginal communities and experts in cultural astronomy was able to stop the transfer. The whole process and its impact on the local community have promoted a deep discussion about art, science and cultural colonialism. In this paper we aim to address this debate and its consequences. This will allow us to think about contemporary forms of colonialism that are hidden in many scientific and artistic projects. Furthermore, we aim to debate about the most effective ways of protecting astronomical heritage in the Third World.

  20. MALARIA VECTORS IN SAN JOSÉDEL GUAVIARE, ORINOQUIA, COLOMBIA

    PubMed Central

    JIMÉNEZ, IRENE P.; CONN, JAN E.; BROCHERO, HELENA

    2015-01-01

    This study was conducted to determine Anopheles species composition and their natural infectivity by human Plasmodium in 2 localities with the highest malaria transmission in San Jose del Guaviare, Guaviare, Colombia. A total of 1,009 Anopheles mosquitoes were collected using human landing catches during 8 months in 2010. Anopheles darlingi was the most abundant (83.2%) followed by An. albitarsis s.l. (8.6%), Anopheles braziliensis (3.8%), An. oswaldoi s.l. (1%), and An. rangeli (0.3%). Anopheles darlingi showed the highest human biting rate, and it was found naturally infected with Plasmodium vivax VK210 (0.119%) using enzyme-linked immunosorbent assays. All species were collected biting both indoors and outdoors. Anopheles darlingi showed biting activity overnight with an indoor peak between 1200–0100 h. Therefore, we recommend that malaria prevention strategies focus on 1) insecticide-treated nets to reduce human–vector contact when people are most exposed and unprotected; 2) accurate diagnoses; 3) adequate treatment for patients; 4) more timely epidemiological notification; and 5) improved entomological surveillance. PMID:25102591

  1. Estudio multiespectral del remanente de supernova W 28

    NASA Astrophysics Data System (ADS)

    Dubner, G.; Velázquez, P.; Castelletti, G.

    Se presentan observaciones en continuo de radio con muy alta resolución angular y sensibilidad del remanente de supernova (RSN) W28. Las observaciones fueron realizadas con el interferómetro Very Large Array (Estados Unidos), en las configuraciones C y D, en 1415 y 324 MHz. Por la gran extensión de este remanente (diámetro ~ 1o), las observaciones en 1415 MHz se realizaron en modo mosaico, combinando 48 apuntamientos diferentes en una única imagen. En ambas frecuencias los datos se procesaron con el agregado de observaciones de menor resolución angular, a fin de recuperar información en todas las frecuencias espaciales y obtener estimaciones precisas de densidad de flujo. Las imágenes resultantes muestran por primera vez la presencia de extensiones con forma de arco, cuya naturaleza se investiga. Las observaciones en radio se comparan con una imagen óptica de W28, y con la emisión en rayos X, observada con el satélite ROSAT. Este remanente muestra una clara morfología híbrida, tipo cáscara en frecuencias de radio y de centro lleno en las bandas óptica y de rayos X blandos.

  2. Seismicity following the 1985 eruption of Nevado del Ruiz, Colombia

    USGS Publications Warehouse

    Zollweg, J.E.

    1990-01-01

    Over 200 of the best-recorded earthquakes occurring near Nevado del Ruiz, Colombia, between December 1985 and May 1986 are examined for spatial patterns, information on local stress orientations, and evidence for seismogenic structures that may be related to magma-transport processes. These earthquakes occurred following the devastating eruption of November 13, 1985. Earthquake activity that is probably related to the volcanic system occurs over a large area, of the order of 50 km2. A pattern of earthquakes beneath the southern half of Ruiz may be the expression of a conduit system, but evidence is inconclusive due to low spatial resolution of most hypocenters. Epicenter and first-motion plots suggest most earthquakes occur on small faults of varying orientation. Most seismicity during this time period was unrelated to mapped faults, including some with Holocene offsets, except for the Villamaria Fault near Ruiz's northeast sector. Composite focal mechanisms show a variation of nearly 90?? in the strike of T-axes and indicate Ruiz is in a zone of local extension. ?? 1990.

  3. Ethnoveterinary medicine in the Arribes del Duero, western Spain.

    PubMed

    González, José A; García-Barriuso, Mónica; Amich, Francisco

    2011-06-01

    Currently, traditional ethnoveterinary practices are rare in Europe and the plants used previously have been replaced by the modern drugs used by national veterinary services. However, in some rural areas of the Mediterranean basin these traditional practices persist. Here we analyze the plant resources still used, or that have been used up until recently, for the treatment of the health and comfort of animals in a region in the central-western part of the Iberian Peninsula, the Arribes del Duero. We document the use of 84 species, belonging to 39 families (with a total of 2243 use-reports), and 62 herbal remedies based on the use of a single plant species (43) and cited by at least three independent informants. The veterinary use of the Ranunculaceae Clematis campaniflora is reported for the first time. We also identify several plants used as bedding or fodder for livestock and discuss the relevance of some toxic plants and some "magical-curative" aspects reported in the territory. PMID:21461643

  4. Paso del Norte ozone study VOC measurements, 1996

    SciTech Connect

    Seila, R.L.; Main, H.; Arriaga, J.L.; Martinez, G.V.; Ramadan, A.B.

    1999-11-01

    The results of VOC determinations of ambient air samples collected at surface air quality monitoring sites and near sources of interest on the US and Mexican side of the border during six weeks of the 1996 Paso del Norte Ozone Study are reported. Carbonyl samples were collected on DNPH impregnated cartridges at three surface sites and analyzed by HPLC to quantify 13, C-1 to C-8 species. Whole air samples were collected in electro-polished stainless steel canisters which were returned to laboratory for determination of C-2 to C-10+ hydrocarbons by cryogenic preconcentration capillary gas chromatography with flame ionization detection (gc-fid). Several sources were sampled: rush hour traffic, propane-powered bus exhaust, automobile paint shop emissions, propane fuel, petroleum refinery, and industrial manufacturing site. Spatial and temporal characteristics of VOC species concentrations and compositions are presented. Overall surface TNMOC values ranged from 0.1 to 3.4 ppmC with the highest concentrations recorded in the morning at three vehicle-dominated sites, two in Cuidad Juarez and one in downtown El Paso. Toluene in El Paso samples and propane, which is used as a cooking and transportation fuel in Cuidad Juarez, were the most abundant hydrocarbons.

  5. Paso del Norte ozone study VOC measurements, 1996

    SciTech Connect

    Seila, R.L.; Main, H.; Arriaga, J.L.; Martinez, G.V.; Ramadan, A.B.

    1999-01-01

    The results of VOC determinations of ambient air samples collected at surface air quality monitoring sites and near sources of interest on the US and Mexican side of the border during six weeks of the 1996 Paso del Norte Ozone Study are reported. Carbonyl samples were collected on DNPH impregnated cartridges at three surface sites and analyzed by HPLC to quantify 13, C-1 to C-8 species. Whole air samples were collected in electro-polished stainless steel canisters which were returned to laboratory for determination of C-2 to C-10+ hydrocarbons by cryogenic preconcentration capillary gas chromatography with flame ionization detection (gc-fid). Several sources were sampled: rush hour traffic, propane-powered bus exhaust, automobile paint shop emissions, propane fuel, petroleum refinery, and industrial manufacturing site. Spatial and temporal characteristics of VOC species concentrations and compositions are presented. Overall surface TNMOC values ranged from 0.1 to 3.4 ppmC with the highest concentrations recorded in the morning at three vehicle-dominated sites, two in Cuidad Juarez and one in downtown El Paso. Toluene in El Paso samples and propane, which is used as a cooking and transportation fuel in Cuidad Juarez, were the most abundant hydrocarbons.

  6. El uso de la neuromodulación para el tratamiento del temblor

    PubMed Central

    Bendersky, Damián; Ajler, Pablo; Yampolsky, Claudio

    2014-01-01

    Introducción: El temblor puede ser un desorden incapacitante y el tratamiento de primera línea para estos pacientes es farmacológico. Sin embargo, este tratamiento puede llevar a una reducción satisfactoria del temblor en sólo el 50% de los pacientes con temblor esencial. La talamotomía era el tratamiento de elección para el temblor refractario al tratamiento médico hasta que comenzó a utilizarse la estimulación cerebral profunda (ECP) del núcleo ventral intermedio (Vim) del tálamo. En la actualidad, raramente se realiza la talamotomía. Métodos: Este artículo es una revisión no sistemática de las indicaciones, resultados, parámetros de programación y técnica quirúrgica de la ECP del Vim para el tratamiento del temblor. Resultados: Aunque los resultados clínicos son similares usando la talamotomía o la ECP del Vim, la primera causa más efectos adversos que la última. Además, la ECP puede ser usada bilateralmente, mientras que la talamotomía tiene un alto riesgo de causar disartria cuando se realiza de ambos lados. La ECP del Vim logró una adecuada mejoría del temblor en varias series de pacientes con temblor causado por temblor esencial, enfermedad de Parkinson o esclerosis múltiple. Además del Vim, hay otros blancos que están siendo usados por varios autores, tales como la zona incerta y las radiaciones prelemniscales. Conclusión: La ECP del Vim es un tratamiento útil para el temblor incapacitante refractario al tratamiento médico. Es esencial realizar una precisa selección de pacientes, así como utilizar una técnica quirúrgica correcta. Aún se desconoce el mejor blanco estereotáctico para el temblor, aunque el Vim es el más usado. PMID:25165613

  7. MICROBIAL ECOLOGY AND MOLECULAR CHARACTERIZATION OF PATHOGENS IN FEEDYARD PLAYA AIR AND WATER SAMPLES IN THE HIGH PLAINS OF TEXAS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concentrated animal feeding operations (CAFO) may impact the environment due to nutrient inputs present in the manure, and the sheer volume of manure that must be removed. Consequently, management issues such as odor, presence of pathogens, endotoxins, and dust emissions are introduced. The impact o...

  8. Impact of Diagenesis on Biosignature Preservation Potential in Playa Lake Evaporites of the Verde Formation, Arizona: Implications for Mars Exploration

    NASA Astrophysics Data System (ADS)

    Shkolyar, S.; Farmer, J. D.

    2016-05-01

    We studied evaporite subfacies in the Verde Fmn., AZ. We identified diagenetic pathways and assessed how diagenesis affected biosignature preservation potential (BPP) in each. Results revealed eight pathways, each with diverse impacts on BPP.

  9. Screening for F508del as a first step in the molecular diagnosis of cystic fibrosis*,**

    PubMed Central

    Marson, Fernando Augusto de Lima; Bertuzzo, Carmen Silvia; Ribeiro, Maria Ângela Gonçalves de Oliveira; Ribeiro, Antônio Fernando; Ribeiro, José Dirceu

    2013-01-01

    OBJECTIVE: To determine the relevance of screening for the F508del mutation of the cystic fibrosis transmembrane conductance regulator gene as a first step in the genetic diagnosis of cystic fibrosis (CF) by associating the genotype with various clinical variables. METHODS: We evaluated 180 CF patients regarding the F508del mutation. The clinical data were obtained from the medical records of the patients and from interviews with their parents or legal guardians. RESULTS: Of the 180 patients studied, 65 (36.1%) did not carry the F508del mutation (group 0 [G0]), 67 (37.2%) were F508del heterozygous (G1), and 48 (26.7%) were F508del homozygous (G2). All three groups showed associations with the clinical variables. Homozygosis was associated with younger patients, younger age at CF diagnosis, and younger age at the first isolation of Pseudomonas aeruginosa (PA), as well as with higher prevalence of pancreatic insufficiency (PI) and non-mucoid PA (NMPA) colonization. In comparison with G1+G2 patients, G0 patients were older; first experienced clinical symptoms, digestive disease, and pulmonary disease at an older age; were older at CF diagnosis and at first PA isolation; and had a lower prevalence of PI and meconium ileus, as well as of colonization by NMPA, mucoid PA, and Burkholderia cepacia. In G1 patients, values were intermediate for age at CF diagnosis; age at first PA isolation, first pulmonary symptoms, and first clinical manifestations; MPA colonization; and OR for PI. CONCLUSIONS: The identification of F508del in 63.9% of the patients studied showed that this can be a useful tool as a first step in the genetic diagnosis of CF. The F508del genotype was associated with clinical severity of the disease, especially with the variables related to CF onset. PMID:23857699

  10. Manipulating proteostasis to repair the F508del-CFTR defect in cystic fibrosis.

    PubMed

    Esposito, Speranza; Tosco, Antonella; Villella, Valeria R; Raia, Valeria; Kroemer, Guido; Maiuri, Luigi

    2016-12-01

    Cystic fibrosis (CF) is a lethal monogenic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that entails the (diagnostic) increase in sweat electrolyte concentrations, progressive lung disease with chronic inflammation and recurrent bacterial infections, pancreatic insufficiency, and male infertility. Therapies aimed at restoring the CFTR defect have emerged. Thus, a small molecule which facilitates chloride channel opening, the potentiator Ivacaftor, has been approved for the treatment of CF patients bearing a particular class of rare CFTR mutations. However, small molecules that directly target the most common misfolded CFTR mutant, F508del, and improve its intracellular trafficking in vitro, have been less effective than expected when tested in CF patients, even in combination with Ivacaftor. Thus, new strategies are required to circumvent the F508del-CFTR defect. Airway and intestinal epithelial cells from CF patients bearing the F508del-CFTR mutation exhibit an impressive derangement of cellular proteostasis, with oxidative stress, overactivation of the tissue transglutaminase (TG2), and disabled autophagy. Proteostasis regulators such as cysteamine can rescue and stabilize a functional F508del-CFTR protein through suppressing TG2 activation and restoring autophagy in vivo in F508del-CFTR homozygous mice, in vitro in CF patient-derived cell lines, ex vivo in freshly collected primary patient's nasal cells, as well as in a pilot clinical trial involving homozygous F508del-CFTR patients. Here, we discuss how the therapeutic normalization of defective proteostasis can be harnessed for the treatment of CF patients with the F508del-CFTR mutation. PMID:26976279

  11. Modelo semi-empírico de protuberancia solar a partir del diagnóstico de densidades

    NASA Astrophysics Data System (ADS)

    Cirigliano, D.; Vial, J. C.; Rovira, M.

    A partir de la observación del espectro del quintuplete de C III alrededor de 1175 Å, se ha realizado el diagnóstico de la densidad y presión electrónica, basado en el cálculo del cociente de las intensidades observadas. Una vez establecida la densidad electrónica, y con el cálculo de las velocidades Doppler, hemos investigado el flujo de masa en la protuberancia en función de la temperatura. Estableciendo como hipótesis la conservación del número de partículas que ingresan y salen del cuerpo de la protuberancia, se investiga la variación del área de un tubo de flujo semi-empírico en función de la temperatura. A partir de dicho diagnóstico, se examina el comportamiento del radio del tubo magnético en función de la temperatura, los que dan cuenta de la abertura de las líneas de campo magnético que confinan el plasma y de la divergencia del campo magnético en diferentes alturas de la atmósfera solar.

  12. Resistivity structure of the Del Mar methane seep.

    NASA Astrophysics Data System (ADS)

    Kannberg, P. K.; Constable, S.

    2015-12-01

    In March of 2015 we mapped the resistivity structure of the Del Mar methane seep in the inner California borderlands using a deep towed electromagnetic (EM) source and receiver array. Located in the San Diego trough at a depth of 1km, the seep site is on the flank of a mound associated with a transpressive step in the San Diego trough fault. The seep site has previously been associated with seafloor pockmarks, acoustic wipeouts, chemosynthetic communities, and active methane bubble venting. Controlled source electromagnetic (CSEM) surveys are performed by deep-towing an EM source that is transmitting a known signal; this signal is detected by towed receivers. This transmitted signal is altered by the electrical properties of the surrounding environment. Compared to seismic methods, EM methods are largely insensitive to free gas, making it an especially useful tool for detecting electrically resistive methane hydrate in areas of active gas venting. We used a 50m dipole transmitting 100A, with 3-axis electric field receivers spaced at 130m, 230m, 330m, and 430m behind the transmitter dipole center. The receiver data are inverted using MARE2DEM, a finite element 2D inversion routine. The inversion results show the background resistivity of the trough sediments to be about 1-2 ohmm, and are largely featureless outside of the seep site. However at the seep site we see a decanter-shaped 100 ohmm resistor whose base is 100m below the seafloor, and 1km wide at its widest. This feature narrows at the top to form a pipe structure about 200m wide that extends to the seafloor. These resistive structures are interpreted to be methane hydrate resulting from methane rich fluid flow along faults associated with the transpressional system that brackets the seep site.

  13. Predicting Nonspecific Ion Binding Using DelPhi

    PubMed Central

    Petukh, Marharyta; Zhenirovskyy, Maxim; Li, Chuan; Li, Lin; Wang, Lin; Alexov, Emil

    2012-01-01

    Ions are an important component of the cell and affect the corresponding biological macromolecules either via direct binding or as a screening ion cloud. Although some ion binding is highly specific and frequently associated with the function of the macromolecule, other ions bind to the protein surface nonspecifically, presumably because the electrostatic attraction is strong enough to immobilize them. Here, we test such a scenario and demonstrate that experimentally identified surface-bound ions are located at a potential that facilitates binding, which indicates that the major driving force is the electrostatics. Without taking into consideration geometrical factors and structural fluctuations, we show that ions tend to be bound onto the protein surface at positions with strong potential but with polarity opposite to that of the ion. This observation is used to develop a method that uses a DelPhi-calculated potential map in conjunction with an in-house-developed clustering algorithm to predict nonspecific ion-binding sites. Although this approach distinguishes only the polarity of the ions, and not their chemical nature, it can predict nonspecific binding of positively or negatively charged ions with acceptable accuracy. One can use the predictions in the Poisson-Boltzmann approach by placing explicit ions in the predicted positions, which in turn will reduce the magnitude of the local potential and extend the limits of the Poisson-Boltzmann equation. In addition, one can use this approach to place the desired number of ions before conducting molecular-dynamics simulations to neutralize the net charge of the protein, because it was shown to perform better than standard screened Coulomb canned routines, or to predict ion-binding sites in proteins. This latter is especially true for proteins that are involved in ion transport, because such ions are loosely bound and very difficult to detect experimentally. PMID:22735539

  14. 1996 Paso del Norte ozone study VOC measurements

    SciTech Connect

    Seila, R.L.; Main, H.; Arriaga, J.L.; Martinez, G.; Ramadan, A.B.

    1999-07-01

    Ambient air VOC samples were collected at surface air quality monitoring sites, near sources of interest, and aloft on the US and Mexican side of the border during a six week period of the 1996 Paso del Norte Ozone Study. On nine intensive operations (IOP) days, when high ozone concentrations were forecast, five 2-hr samples were collected at five IOP sites, three on the US side and two on the Mexican side. Six special survey sites on the US side and two on the Mexican side were sampled to characterize up-wind, down-wind and other emissions. In Ciudad Juarez, rush hour traffic, propane-powered bus exhaust, automobile paint shop emissions, propane and butane fuels, and an industrial manufacturing site were sampled. Carbonyl samples were collected at three surface sites. Carbonyl and canister grab samples were also collected during aircraft and hot air balloon flights. Most of the hydrocarbon samples were collected in electro-polished stainless steel canisters which were returned to laboratories for determination of C-2 to C-10+ hydrocarbons by cryogenic preconcentration GC-FID. The carbonyl samples were collected on DNPH impregnated C-18 Sep-Pak cartridges and analyzed by HPLC to quantify 13, C-1 to C-8 species. This paper presents the spatial and temporal characteristics of VOC species concentrations and compositions to examine the differences and similarities of the various locations and time periods. Overall surface TNMOC values ranged from 0.1 to 3.4 ppmC with the highest concentrations being recorded in the morning at three vehicle-dominated sites, two in Ciudad Juarez and one in downtown El Paso. Toluene in El Paso samples and propane, which is used as a cooking and transportation fuel in Ciudad Juarez, were the most abundant hydrocarbons. The most abundant carbonyls were acetaldehyde and acetone.

  15. La implantacion del enfoque constructivista en el aula de ciencia: Estudio de caso multiple

    NASA Astrophysics Data System (ADS)

    Arroyo Betancourt, Luz I.

    Esta investigacion estudia la implantacion del enfoque constructivista en tres aulas de ciencia del contexto puertorriqueno. Se auscultaron las practicas educativas que utilizan maestras consideradas constructivistas y la correspondencia de sus practicas educativas con los elementos esenciales de la didactica que proponen los teoricos de los planteamientos constructivistas. Se ausculto, ademas, a que vision del enfoque constructivista responden las expresiones de las maestras acerca de su practica educativa y como compara con su quehacer, a la luz de los elementos esenciales de las visiones constructivistas piagetiana, social y radical. Se utilizo el diseno de estudio descriptivo de caso multiple. El estudio se baso en entrevistas a profundidad, revision de documentos y observacion no participativa a la sala de clases. El contexto fueron tres escuelas publicas de la Region Educativa de San Juan, una elemental, una intermedia y una superior. Los resultados confirmaron que la transicion hacia el enfoque constructivista es un proceso que toma tiempo, dedicacion y la participacion en adiestramientos y readiestramientos acerca del nuevo enfoque. Las maestras coinciden en la mayoria de las practicas educativas que utilizan para implantar el enfoque constructivista de ensenanza y difieren en algunas debido, probablemente, a que han tenido que adaptarlas a los correspondientes niveles de ensenanza: elemental, intermedio y superior. Dos de las maestras planifican por conceptos generadores, mientras que una de ellas planifica siguiendo la guia que recibe del Departamento de Educacion. Difieren ademas, en el enfasis que confieren al inquirir cientifico. Con relacion a la correspondencia entre la vision manifestada por las maestras a la luz de las visiones piagetiana, social y radical, aparentemente, las preguntas del protocolo de entrevistas no lograron evocar la informacion con suficiente profundidad, por lo que la investigadora tuvo que inferir las visiones de las

  16. Using Del-1 to Tip the Angiogenic Balance in Endothelial Cells in Modular Constructs

    PubMed Central

    Ciucurel, Ema C.; Vlahos, Alexander E.

    2014-01-01

    Modular tissue engineering is a method of building vascularized tissue-engineered constructs. Submillimeter-sized collagen pieces (modules) coated with a layer of endothelial cells (EC; vascular component), and with embedded functional cells, are self-assembled into a larger, three-dimensional tissue. In this study, we examined the use of developmental endothelial locus-1 (Del-1), an extracellular matrix protein with proangiogenic properties, as a means of tipping the angiogenic balance in human umbilical vein endothelial cells incorporated in modular tissue-engineered constructs. The motivation was to enhance the vascularization of these constructs upon transplantation in vivo, in this case, without the use of exogenous mesenchymal stromal cells. EC were transduced using a lentiviral construct to overexpress Del-1. The Del-1 EC formed more sprouts in a fibrin gel sprouting assay in vitro compared with eGFP (control) transduced EC, as expected. Del-1 EC had a distinct profile of gene expression (upregulation of matrix metalloproteinase-9 [MMP-9], urokinase-type plasminogen activator [uPA/PLAU], vascular endothelial growth factor [VEGF-A], and intercellular adhesion molecule-1 [ICAM-1]; downregulation of angiopoietin-2 [Ang2]), also supporting the notion of “tipping the angiogenic balance”. On the other hand, contrary to our expectations, when Del-1 EC-coated modules were implanted subcutaneously in a severe combined immunodeficient/beige animal model, the proangiogenic effect of Del-1 was less remarkable. There was only a small increase in the number of blood vessels formed in Del-1 implants compared with the eGFP implants, and only few blood vessels formed at the implant site in both cases. This was presumed due to limited EC survival after transplantation. We speculate that if we could improve EC survival in our study (for example, by adding other prosurvival factors or supporting cells), we would see a greater Del-1-induced angiogenic benefit in vivo as a

  17. Detecting a hierarchical genetic population structure via Multi-InDel markers on the X chromosome

    PubMed Central

    Fan, Guang Yao; Ye, Yi; Hou, Yi Ping

    2016-01-01

    Detecting population structure and estimating individual biogeographical ancestry are very important in population genetics studies, biomedical research and forensics. Single-nucleotide polymorphism (SNP) has long been considered to be a primary ancestry-informative marker (AIM), but it is constrained by complex and time-consuming genotyping protocols. Following up on our previous study, we propose that a multi-insertion-deletion polymorphism (Multi-InDel) with multiple haplotypes can be useful in ancestry inference and hierarchical genetic population structures. A validation study for the X chromosome Multi-InDel marker (X-Multi-InDel) as a novel AIM was conducted. Genetic polymorphisms and genetic distances among three Chinese populations and 14 worldwide populations obtained from the 1000 Genomes database were analyzed. A Bayesian clustering method (STRUCTURE) was used to discern the continental origins of Europe, East Asia, and Africa. A minimal panel of ten X-Multi-InDels was verified to be sufficient to distinguish human ancestries from three major continental regions with nearly the same efficiency of the earlier panel with 21 insertion-deletion AIMs. Along with the development of more X-Multi-InDels, an approach using this novel marker has the potential for broad applicability as a cost-effective tool toward more accurate determinations of individual biogeographical ancestry and population stratification. PMID:27535707

  18. The RGD finger of Del-1 is a unique structural feature critical for integrin binding

    SciTech Connect

    Schürpf, Thomas; Chen, Qiang; Liu, Jin-huan; Wang, Rui; Springer, Timothy A.; Wang, Jia-huai

    2012-11-13

    Developmental endothelial cell locus-1 (Del-1) glycoprotein is secreted by endothelial cells and a subset of macrophages. Del-1 plays a regulatory role in vascular remodeling and functions in innate immunity through interaction with integrin {alpha}{sub V}{beta}{sub 3}. Del-1 contains 3 epidermal growth factor (EGF)-like repeats and 2 discoidin-like domains. An Arg-Gly-Asp (RGD) motif in the second EGF domain (EGF2) mediates adhesion by endothelial cells and phagocytes. We report the crystal structure of its 3 EGF domains. The RGD motif of EGF2 forms a type II' {beta} turn at the tip of a long protruding loop, dubbed the RGD finger. Whereas EGF2 and EGF3 constitute a rigid rod via an interdomain calcium ion binding site, the long linker between EGF1 and EGF2 lends considerable flexibility to EGF1. Two unique O-linked glycans and 1 N-linked glycan locate to the opposite side of EGF2 from the RGD motif. These structural features favor integrin binding of the RGD finger. Mutagenesis data confirm the importance of having the RGD motif at the tip of the RGD finger. A database search for EGF domain sequences shows that this RGD finger is likely an evolutionary insertion and unique to the EGF domain of Del-1 and its homologue milk fat globule-EGF 8. The RGD finger of Del-1 is a unique structural feature critical for integrin binding.

  19. Del1 Knockout Mice Developed More Severe Osteoarthritis Associated with Increased Susceptibility of Chondrocytes to Apoptosis

    PubMed Central

    Wang, Zhen; Tran, Misha C.; Bhatia, Namrata J.; Hsing, Alexander W.; Chen, Carol; LaRussa, Marie F.; Fattakhov, Ernst; Rashidi, Vania; Jang, Kyu Yun; Choo, Kevin J.; Nie, Xingju; Mathy, Jonathan A.; Longaker, Michael T.; Dauskardt, Reinhold H.; Helms, Jill A.; Yang, George P.

    2016-01-01

    Objective We identified significant expression of the matricellular protein, DEL1, in hypertrophic and mature cartilage during development. We hypothesized that this tissue-specific expression indicated a biological role for DEL1 in cartilage biology. Methods Del1 KO and WT mice had cartilage thickness evaluated by histomorphometry. Additional mice underwent medial meniscectomy to induce osteoarthritis, and were assayed at 1 week for apoptosis by TUNEL staining and at 8 weeks for histology and OA scoring. In vitro proliferation and apoptosis assays were performed on primary chondrocytes. Results Deletion of the Del1 gene led to decreased amounts of cartilage in the ears and knee joints in mice with otherwise normal skeletal morphology. Destabilization of the knee led to more severe OA compared to controls. In vitro, DEL1 blocked apoptosis in chondrocytes. Conclusion Osteoarthritis is among the most prevalent diseases worldwide and increasing in incidence as our population ages. Initiation begins with an injury resulting in the release of inflammatory mediators. Excessive production of inflammatory mediators results in apoptosis of chondrocytes. Because of the limited ability of chondrocytes to regenerate, articular cartilage deteriorates leading to the clinical symptoms including severe pain and decreased mobility. No treatments effectively block the progression of OA. We propose that direct modulation of chondrocyte apoptosis is a key variable in the etiology of OA, and therapies aimed at preventing this important step represent a new class of regenerative medicine targets. PMID:27505251

  20. Detecting a hierarchical genetic population structure via Multi-InDel markers on the X chromosome.

    PubMed

    Fan, Guang Yao; Ye, Yi; Hou, Yi Ping

    2016-01-01

    Detecting population structure and estimating individual biogeographical ancestry are very important in population genetics studies, biomedical research and forensics. Single-nucleotide polymorphism (SNP) has long been considered to be a primary ancestry-informative marker (AIM), but it is constrained by complex and time-consuming genotyping protocols. Following up on our previous study, we propose that a multi-insertion-deletion polymorphism (Multi-InDel) with multiple haplotypes can be useful in ancestry inference and hierarchical genetic population structures. A validation study for the X chromosome Multi-InDel marker (X-Multi-InDel) as a novel AIM was conducted. Genetic polymorphisms and genetic distances among three Chinese populations and 14 worldwide populations obtained from the 1000 Genomes database were analyzed. A Bayesian clustering method (STRUCTURE) was used to discern the continental origins of Europe, East Asia, and Africa. A minimal panel of ten X-Multi-InDels was verified to be sufficient to distinguish human ancestries from three major continental regions with nearly the same efficiency of the earlier panel with 21 insertion-deletion AIMs. Along with the development of more X-Multi-InDels, an approach using this novel marker has the potential for broad applicability as a cost-effective tool toward more accurate determinations of individual biogeographical ancestry and population stratification. PMID:27535707

  1. Pseudomonas aeruginosa Reduces VX-809 Stimulated F508del-CFTR Chloride Secretion by Airway Epithelial Cells

    PubMed Central

    Stanton, Bruce A.; Coutermarsh, Bonita; Barnaby, Roxanna; Hogan, Deborah

    2015-01-01

    Background P. aeruginosa is an opportunistic pathogen that chronically infects the lungs of 85% of adult patients with Cystic Fibrosis (CF). Previously, we demonstrated that P. aeruginosa reduced wt-CFTR Cl secretion by airway epithelial cells. Recently, a new investigational drug VX-809 has been shown to increase F508del-CFTR Cl secretion in human bronchial epithelial (HBE) cells, and, in combination with VX-770, to increase FEV1 (forced expiratory volume in 1 second) by an average of 3-5% in CF patients homozygous for the F508del-CFTR mutation. We propose that P. aeruginosa infection of CF lungs reduces VX-809 + VX-770- stimulated F508del-CFTR Cl secretion, and thereby reduces the clinical efficacy of VX-809 + VX-770. Methods and Results F508del-CFBE cells and primary cultures of CF-HBE cells (F508del/F508del) were exposed to VX-809 alone or a combination of VX-809 + VX-770 for 48 hours and the effect of P. aeruginosa on F508del-CFTR Cl secretion was measured in Ussing chambers. The effect of VX-809 on F508del-CFTR abundance was measured by cell surface biotinylation and western blot analysis. PAO1, PA14, PAK and 6 clinical isolates of P. aeruginosa (3 mucoid and 3 non-mucoid) significantly reduced drug stimulated F508del-CFTR Cl secretion, and plasma membrane F508del-CFTR. Conclusion The observation that P. aeruginosa reduces VX-809 and VX-809 + VX-770 stimulated F508del CFTR Cl secretion may explain, in part, why VX-809 + VX-770 has modest efficacy in clinical trials. PMID:26018799

  2. High mountain soils and periglacial features at the Torres del Paine, National Park Torres del Paine, Chile.

    NASA Astrophysics Data System (ADS)

    Senra, Eduardo; Schaefer, Carlos; Simas, Felipe; Gjorup, Davi

    2015-04-01

    The Torres del Paine National Park (TPNP) is located on the southern limit of the Andean Southern Ice Field, part of the Magallanes and Antartica Chilena region, in the province of Ultima Esperanza. The TPNP has a very heterogeneous climate due to orographic influence and wet air masses from the Pacific. The geology is basically Cretaceous metasedimentary rocks and Miocene granitic plutons and batholiths. We studied the main soils and geoenvironments of Mt Ferrier mountain and its surroundings, based on soils , landforms and vegetation aspects. The geoenvironmental stratification was based on the combined variation and integration of pedo-litho-geomorphological features with the vegetation. WE used detailed geological maps, a DEM and slope maps and WorlView II satellite images. Fifteen soils profiles were sampled and classified according to Soil Taxonomy (2010) at all genovironments, ranging from 50 m a.s.l to the at high plateau just below the permanent snowline, under periglacial conditions (~1004m asl). Three soil temperature and moisture monitoring sites were set, allowing for 24 consecutive months (2011 to 2013). Seven geoenvironments were identified with distinct soil and landform characteristics, all with a similar geological substrate. The landform and vegetation have a strong connection with the landscape dynamic, controlling erosional and depositional processes, resulting from glacier advances and retreats in the Late Quaternary. Wind blown materials is widespread, in the form of loess material, accumulating in the higher parts of the landscape. On the other hand, accumulation of organic matter in the water-saturated depressions is common in all altitudes. Generally the soils are acidic and dystrophic, with little exceptions. The following geoenvironments were identified: Periglacial Tundra, Loess slopes, Talus and scarpmentd, Fluvio-glacial terraces, Fluvio-lacustrine plains, Moraines and Paleodunes. The regional pedology show the occurrence of five soil

  3. The novel complex allele [A238V;F508del] of the CFTR gene: clinical phenotype and possible implications for cystic fibrosis etiological therapies.

    PubMed

    Diana, Anna; Polizzi, Angela Maria; Santostasi, Teresa; Ratclif, Luigi; Pantaleo, Maria Giuseppina; Leonetti, Giuseppina; Iusco, Danila Rosa; Gallo, Crescenzio; Conese, Massimo; Manca, Antonio

    2016-06-01

    Few mutations in cis have been annotated for F508del homozygous patients. Southern Italy patients who at a first analysis appeared homozygous for the F508del mutation (n=63) or compound heterozygous for the F508del and another mutation in the cystic fibrosis transmembrane conductance regulator gene (n=155) were searched for the A238V mutation in exon 6. The allelic frequency of the complex allele [A238V;F508del] was 0.04. When the whole data set was used (comprised also of 56 F508del/F508del and 34 F508del/other mutation controls), no differences reached the statistical significance in the clinical parameters, except chloride concentrations which were lower in [A238V;F508del]/other mutation compared with F508del/other mutation (P=0.03). The two study groups presented less complications than the control groups. Within the minimal data set (34 F508del/F508del, 27 F508del/other mutation, 4 [A238V;F508del]/F508del cases and 5 [A238V;F508del]/other mutation cases); that is, presenting all the variables in each patient, forced expiratory volume in 1 s and forced vital capacity presented a trend to lower levels in the study groups in comparison with the F508del/F508del group, and C-reactive protein approximated statistically significant higher levels in the [A238V;F508del]/other mutation as compared with F508del/F508del patients (P=0.09). The analysis of statistical dependence among the variables showed a significant anticorrelation between chloride and body mass index in the [A238V;F508del]/other mutation group. In conclusion, the complex allele [A238V;F508del] seems to be associated with less general complications than in the control groups, on the other hand possibly giving a worse pulmonary phenotype and higher systemic/local inflammatory response. These findings have implications for the correct recruitment and clinical response of F508del patients in the clinical trials testing the new etiological drugs for cystic fibrosis. PMID:26911355

  4. Integrated global background monitoring network. Preliminary results from Torres del Paine and Olympic National Parks

    SciTech Connect

    Wiersma, G.B.; Kohler, A.; Boelcke, C.; Baker, G.; Harmon, M.; Weber, C.; Gonzales, J.

    1985-10-01

    During 1984, a pilot project was initiated for monitoring pollution at Torres del Paine National Park in southern Chile and Olympic National Park in the United States. These are two of three initial sites that are to be established as part of an integrated global backgound monitoring network. Eventually, the plan is to establish a world-wide system of such sites. We collected and analyzed samples of the soil, water, air, and two species of plants (moss and lichen). We also collected and analyzed samples of the forest litter. We compared the samples of soil and vegetation against reference samples. We also compared samples of soil, vegetation, and of organic material from Torres del Paine against similar samples from Olympic and Sequoia-Kings Canyon National Parks in the United States. Although the data is preliminary, it is in agreement with out initial hypothesis that Torres del Paine and Olympic National Parks are not a polluted sites.

  5. Biotic association and palaeoenvironmental reconstruction of the "Loma del Pterodaustro" fossil site (Early Cretaceous, Argentina)

    USGS Publications Warehouse

    Chiappe, L.; Rivarola, D.; Cione, A.; Fregenal-Martinez, M.; Sozzi, H.; Buatois, L.; Gallego, O.; Laza, J.; Romero, E.; Lopez-Arbarello, A.; Buscalioni, A.; Marsicano, C.; Adamonis, S.; Ortega, F.; McGehee, S.; Di, Iorio O.

    1998-01-01

    A sedimentological analysis of the basal section of the Early Cretaceous, lacustrine Lagarcito Formation at "Loma del Pterodaustro" (San Luis, Argentina) and a summary of its biological components are presented. Three sedimentological facies can be recognized in the basal sequence of the Lagarcito Formation. Fossil remains are particularly abundant in laminated claystones of a facies interpreted as deposits formed in offshore areas of the lake. The preservation of delicate structures allows recognition of these deposits as a Konservat Lagersta??tte. Up to now, rocks at "Loma del Pterodaustro" have yielded plants, conchostracans, semionotid and pleuropholid fishes, pterodactyloid pterosaurs, and a variety of invertebrate traces. The chronology of the Lagarcito Formation is discussed and it is concluded that this unit is of Albian age. The palaeoenvironment of deposition of the basal sequence of the Lagarcito Formation at "Loma del Pterodaustro" is interpreted as a perennial, shallow lake developed within an alluvial plain, under semiarid climatic conditions.

  6. del-type metrics in Einstein-Aether theory II: nonflat background in arbitrary dimensions

    NASA Astrophysics Data System (ADS)

    Gürses, Metin; Şentürk, Çetin

    2016-05-01

    It was previously proved that the Gödel-type metrics with flat three-dimensional background metric solve exactly the field equations of the Einstein-Aether theory in four dimensions. We generalize this result by showing that the stationary Gödel-type metrics with nonflat background in D dimensions solve exactly the field equations of the Einstein-Aether theory. The reduced field equations are the (D-1)-dimensional Euclidean Ricci-flat and the (D-1)-dimensional source-free Maxwell equations, and the parameters of the theory are left free except c1-c3=1. We give a method to produce exact solutions of the Einstein-Aether theory from the Gödel-type metrics in D dimensions. By using this method, we present explicit exact solutions to the theory by considering the particular cases: (D-1)-dimensional Euclidean flat, conformally flat, and Tangherlini backgrounds.

  7. La relatività debole. La fisica dello spazio e del tempo senza paradossi

    NASA Astrophysics Data System (ADS)

    Selleri, Franco

    2011-06-01

    Secondo Einstein e Poincaré la simultaneità di eventi che hanno luogo in punti diversi dello spazio può essere definita solo per convenzione. Dal punto di vista matematico si dimostra, quindi, che due diverse definizioni di simultaneità corrispondono a due diversi valori del coefficiente e1 della variabile spaziale x presente nelle trasformazioni di Lorentz. A partire da premesse normalmente accettate otterremo diverse dimostrazioni della necessità di reintrodurre il concetto di simultaneità assoluta. Le conseguenze cosmologiche della nuova struttura dello spazio e del tempo andranno contro la cosmologia del Big Bang. Inoltre, dopo questi risultati, il relativismo sopravviverà in una forma meno aspra ("relatività debole") perché risulter privo di quel campionario di paradossi portato dalla teoria della Relatività Speciale.

  8. Mejoras en el apuntado del telescopio de 2,15 mts de CASLEO

    NASA Astrophysics Data System (ADS)

    Aballay, J. L.; Casagrande, A. R.; Pereyra, P. F.; Marún, A. H.

    Con el objeto de optimizar el funcionamiento del telescopio de 2,15 mts. de CASLEO, se están eliminando los motores de calar, de guía y mecánica asociada. Para ésto, se están diseñando dos electrónicas que gobernarán, solamente, el motor de slew y el de tracking. Con el control del motor de slew se realizarán las funciones de slew y calar, controlando desde una PC la placa que maneja las rampas de velocidad. De este modo, el movimiento será programado y por lo tanto, más suave y preciso. Con el control del motor de tracking, a través de un generador de frecuencias programable desde una PC, se proveerá los movimientos necesarios para el tracking y guía.

  9. Deep source model for Nevado del Ruiz Volcano, Colombia, constrained by interferometric synthetic aperture radar observations

    NASA Astrophysics Data System (ADS)

    Lundgren, Paul; Samsonov, Sergey V.; López Velez, Cristian Mauricio; Ordoñez, Milton

    2015-06-01

    Nevado del Ruiz is part of a large volcano complex in the northern Andes of Colombia. Interferometric synthetic aperture radar observations from the RADARSAT-2 satellite since 2011 show steady inflation of the volcano since 2012 at 3-4 cm/yr. The broad (>20 km) deformation pattern from both ascending and descending track data constrain source models for either point or spheroidal sources, both located at >14 km beneath the surface (mean elevation 4.2 km) and 10 km SW of Nevado del Ruiz, below nearby Santa Isabel Volcano. Stress change computations for both sources in the context of a compressive regional stress indicate that dikes propagating from the source should become trapped in sills, possibly leading to a more complex pathway to the surface and explaining the significant lateral separation of the source and Nevado del Ruiz Volcano.

  10. L'eliosismologia: onde sismiche per studiare l'interno del Sole

    NASA Astrophysics Data System (ADS)

    Di Mauro, M. P.

    2014-12-01

    Negli ultimi cinquanta anni siamo stati testimoni di una straordinaria rivoluzione della conoscenza e comprensione della nostra stella grazie alla nascita dell'Eliosismologia, lo studio delle oscillazioni solari. Analogamente a ciò che accade nella Terra durante i terremoti, anche l'interno del Sole è pervaso continuamente da onde sismiche che provocano piccole oscillazioni, ovvero deformazioni della fotosfera. Le oscillazioni sono la manifestazione di diversi processi che avvengono all'interno della struttura del Sole e le frequenze sismiche dei modi osservati e misurati sulla superficie sono legate direttamente ai parametri fisici degli strati interni attraversati dalle onde sismiche. Lo studio delle oscillazioni rappresenta, quindi, l'unico metodo diretto per studiare la struttura e la dinamica interna del Sole. In questo articolo verranno illustrate le caratteristiche generali delle oscillazioni solari e verranno presentati i risultati importanti e i progressi notevoli raggiunti grazie all'Eliosismologia.

  11. CASE REPORT: Phenotypic presentation of the Ser63Del MPZ mutation

    PubMed Central

    Miller, Lindsey J.; Patzko, Agnes; Lewis, Richard A.; Shy, Michael E.

    2013-01-01

    Mutations in MPZ cause CMT1B, the second most frequent cause of CMT1. Elegant studies with Ser63del mice suggest that Ser63del MPZ is retained in the ER where it activates the unfolded protein response (UPR) that contributes to the neuropathy. Clinical information about patients with this mutation is limited. We present clinical and electrophysiological data on a large multigenerational family with CMT1B caused by Ser63del MPZ. The patients have a classical CMT1 phenotype that is much less severe than that of patients with Arg98Cys MPZ that also activates the UPR. These results suggest that clinical presentation along cannot predict which MPZ mutations will be retained in the ER and activate the UPR. PMID:22734905

  12. The 1985 Nevado del Ruiz volcano catastrophe: anatomy and retrospection

    NASA Astrophysics Data System (ADS)

    Voight, Barry

    1990-07-01

    This paper seeks to analyze in an objective way the circumstances and events that contributed to the 1985 Nevado del Ruiz catastrophe, in order to provide useful guidelines for future emergencies. The paper is organized into two principal parts. In the first part, an Anatomy of the catastrophe is developed as a step-by-step chronicle of events and actions taken by individuals and organizations during the period November 1984 through November 1985. This chronicle provides the essential background for the crucial events of November 13. This year-long period is broken down further to emphasize essential chapters: the gradual awareness of the awakening of the volcano; a long period of institutional skepticism reflecting an absence of credibility; the closure of the credibility gap with the September 11 phreatic eruption, followed by an intensive effort to gird for the worst; and a detailed account of the day of reckoning. The second part of the paper, Retrospection, examines the numerous complicated factors that influenced the catastrophic outcome, and attempts to cull a few "lessons from Armero" in order to avoid similar occurrences in the future. In a nutshell, the government on the whole acted responsibly but was not willing to bear the economic or political costs of early evacuation or a false alarm. Science accurately foresaw the hazards but was insufficiently precise to render reliable warning of the crucial event at the last possible minute. Catastrophe was therefore a calculated risk, and this combination — the limitations of predication/detection, the refusal to bear a false alarm and the lack of will to act on the uncertain information available — provided its immediate and most obvious causes. But because the crucial event occurred just two days before the Armero emergency-management plan was to be critically examined and improved, the numerous circumstances which delayed progress of emergency management over the previous year also may be said to have

  13. The 1985 Nevado del Ruiz volcano catastrophe: anatomy and retrospection

    NASA Astrophysics Data System (ADS)

    Voight, Barry

    1990-12-01

    This paper seeks to analyze in an objective way the circumstances and events that contributed to the 1985 Nevado del Ruiz catastrophe, in order to provide useful guidelines for future emergencies. The paper is organized into two principal parts. In the first part, an Anatomy of the catastrophe is developed as a step-by-step chronicle of events and actions taken by individuals and organizations during the period November 1984 through November 1985. This chronicle provides the essential background for the crucial events of November 13. This year-long period is broken down further to emphasize important chapters: the gradual awareness of the awakening of the volcano; a long period of institutional skepticism reflecting an absence of credibility; the closure of the credibility gap with the September 11 phreatic eruption, followed by an intensive effort to gird for the worst; and a detailed account of the day of reckoning. The second part of the paper, Retrospection, examines the numerous complicated factors that influenced the catastrophic outcome, and attempts to cull a few "lessons from Armero" in order to avoid similar occurrences in the future. In a nutshell, the government on the whole acted responsibly but was not willing to bear the economic or political costs of early evacuation or a false alarm. Science accurately foresaw the hazards but was insufficiently precise to render reliable warning of the crucial event at the last possible minute. Catastrophe was therefore a calculated risk, and this combination - the limitations of prediction/detection, the refusal to bear a false alarm and the lack of will to act on the uncertain information available - provided its immediate and most obvious causes. But because the crucial event occurred just two days before the Armero emergency management plan was to be critically examined and improved, the numerous circumstances which delayed progress of emergency management over the previous year also may be said to have

  14. An unexpected effect of TNF-α on F508del-CFTR maturation and function

    PubMed Central

    Bitam, Sara; Urbach, Valérie; Sermet-Gaudelus, Isabelle; Hinzpeter, Alexandre; Edelman, Aleksander

    2015-01-01

    Cystic fibrosis (CF) is a multifactorial disease caused by mutations in the cystic fibrosis transmembrane conductance regulator gene ( CFTR), which encodes a cAMP-dependent Cl - channel. The most frequent mutation, F508del, leads to the synthesis of a prematurely degraded, otherwise partially functional protein. CFTR is expressed in many epithelia, with major consequences in the airways of patients with CF, characterized by both fluid transport abnormalities and persistent inflammatory responses. The relationship between the acute phase of inflammation and the expression of wild type (WT) CFTR or F508del-CFTR is poorly understood. The aim of the present study was to investigate this effect. The results show that 10 min exposure to TNF-alpha (0.5-50ng/ml) of F508del-CFTR-transfected HeLa cells and human bronchial cells expressing F508del-CFTR in primary culture (HBE) leads to the maturation of F508del-CFTR and induces CFTR chloride currents. The enhanced CFTR expression and function upon TNFα is sustained, in HBE cells, for at least 24 h. The underlying mechanism of action involves a protein kinase C (PKC) signaling pathway, and occurs through insertion of vesicles containing F508del-CFTR to the plasma membrane, with TNFα behaving as a corrector molecule. In conclusion, a novel and unexpected action of TNFα has been discovered and points to the importance of systematic studies on the roles of inflammatory mediators in the maturation of abnormally folded proteins in general and in the context of CF in particular. PMID:26594334

  15. Haplotype analysis of the 185delAG BRCA1 mutation in ethnically diverse populations

    PubMed Central

    Laitman, Yael; Feng, Bing-Jian; Zamir, Itay M; Weitzel, Jeffrey N; Duncan, Paul; Port, Danielle; Thirthagiri, Eswary; Teo, Soo-Hwang; Evans, Gareth; Latif, Ayse; Newman, William G; Gershoni-Baruch, Ruth; Zidan, Jamal; Shimon-Paluch, Shani; Goldgar, David; Friedman, Eitan

    2013-01-01

    The 185delAG* BRCA1 mutation is encountered primarily in Jewish Ashkenazi and Iraqi individuals, and sporadically in non-Jews. Previous studies estimated that this is a founder mutation in Jewish mutation carriers that arose before the dispersion of Jews in the Diaspora ∼2500 years ago. The aim of this study was to assess the haplotype in ethnically diverse 185delAG* BRCA1 mutation carriers, and to estimate the age at which the mutation arose. Ethnically diverse Jewish and non-Jewish 185delAG*BRCA1 mutation carriers and their relatives were genotyped using 15 microsatellite markers and three SNPs spanning 12.5 MB, encompassing the BRCA1 gene locus. Estimation of mutation age was based on a subset of 11 markers spanning a region of ∼5 MB, using a previously developed algorithm applying the maximum likelihood method. Overall, 188 participants (154 carriers and 34 noncarriers) from 115 families were included: Ashkenazi, Iraq, Kuchin-Indians, Syria, Turkey, Iran, Tunisia, Bulgaria, non-Jewish English, non-Jewish Malaysian, and Hispanics. Haplotype analysis indicated that the 185delAG mutation arose 750–1500 years ago. In Ashkenazim, it is a founder mutation that arose 61 generations ago, and with a small group of founder mutations was introduced into the Hispanic population (conversos) ∼650 years ago, and into the Iraqi–Jewish community ∼450 years ago. The 185delAG mutation in the non-Jewish populations in Malaysia and the UK arose at least twice independently. We conclude that the 185delAG* BRCA1 mutation resides on a common haplotype among Ashkenazi Jews, and arose about 61 generations ago and arose independently at least twice in non-Jews. PMID:22763381

  16. Development and Utilization of InDel Markers to Identify Peanut (Arachis hypogaea) Disease Resistance

    PubMed Central

    Liu, Lifeng; Dang, Phat M.; Chen, Charles Y.

    2015-01-01

    Peanut diseases, such as leaf spot and spotted wilt caused by Tomato Spotted Wilt Virus, can significantly reduce yield and quality. Application of marker assisted plant breeding requires the development and validation of different types of DNA molecular markers. Nearly 10,000 SSR-based molecular markers have been identified by various research groups around the world, but less than 14.5% showed polymorphism in peanut and only 6.4% have been mapped. Low levels of polymorphism limit the application of marker assisted selection (MAS) in peanut breeding programs. Insertion/deletion (InDel) markers have been reported to be more polymorphic than SSRs in some crops. The goals of this study were to identify novel InDel markers and to evaluate the potential use in peanut breeding. Forty-eight InDel markers were developed from conserved sequences of functional genes and tested in a diverse panel of 118 accessions covering six botanical types of cultivated peanut, of which 104 were from the U.S. mini-core. Results showed that 16 InDel markers were polymorphic with polymorphic information content (PIC) among InDels ranged from 0.017 to 0.660. With respect to botanical types, PICs varied from 0.176 for fastigiata var., 0.181 for hypogaea var., 0.306 for vulgaris var., 0.534 for aequatoriana var., 0.556 for peruviana var., to 0.660 for hirsuta var., implying that aequatoriana var., peruviana var., and hirsuta var. have higher genetic diversity than the other types and provide a basis for gene functional studies. Single marker analysis was conducted to associate specific marker to disease resistant traits. Five InDels from functional genes were identified to be significantly correlated to tomato spotted wilt virus (TSWV) infection and leaf spot, and these novel markers will be utilized to identify disease resistant genotype in breeding populations. PMID:26617627

  17. Haplotype analysis of the 185delAG BRCA1 mutation in ethnically diverse populations.

    PubMed

    Laitman, Yael; Feng, Bing-Jian; Zamir, Itay M; Weitzel, Jeffrey N; Duncan, Paul; Port, Danielle; Thirthagiri, Eswary; Teo, Soo-Hwang; Evans, Gareth; Latif, Ayse; Newman, William G; Gershoni-Baruch, Ruth; Zidan, Jamal; Shimon-Paluch, Shani; Goldgar, David; Friedman, Eitan

    2013-02-01

    The 185delAG* BRCA1 mutation is encountered primarily in Jewish Ashkenazi and Iraqi individuals, and sporadically in non-Jews. Previous studies estimated that this is a founder mutation in Jewish mutation carriers that arose before the dispersion of Jews in the Diaspora ~2500 years ago. The aim of this study was to assess the haplotype in ethnically diverse 185delAG* BRCA1 mutation carriers, and to estimate the age at which the mutation arose. Ethnically diverse Jewish and non-Jewish 185delAG*BRCA1 mutation carriers and their relatives were genotyped using 15 microsatellite markers and three SNPs spanning 12.5 MB, encompassing the BRCA1 gene locus. Estimation of mutation age was based on a subset of 11 markers spanning a region of ~5 MB, using a previously developed algorithm applying the maximum likelihood method. Overall, 188 participants (154 carriers and 34 noncarriers) from 115 families were included: Ashkenazi, Iraq, Kuchin-Indians, Syria, Turkey, Iran, Tunisia, Bulgaria, non-Jewish English, non-Jewish Malaysian, and Hispanics. Haplotype analysis indicated that the 185delAG mutation arose 750-1500 years ago. In Ashkenazim, it is a founder mutation that arose 61 generations ago, and with a small group of founder mutations was introduced into the Hispanic population (conversos) ~650 years ago, and into the Iraqi-Jewish community ~450 years ago. The 185delAG mutation in the non-Jewish populations in Malaysia and the UK arose at least twice independently. We conclude that the 185delAG* BRCA1 mutation resides on a common haplotype among Ashkenazi Jews, and arose about 61 generations ago and arose independently at least twice in non-Jews. PMID:22763381

  18. D469del-COMP retention in chondrocytes stimulates caspase-independent necroptosis.

    PubMed

    Coustry, Françoise; Posey, Karen L; Liu, Peiman; Alcorn, Joseph L; Hecht, Jacqueline T

    2012-02-01

    Mutations in the cartilage oligomeric matrix protein gene (COMP) cause pseudoachondroplasia (PSACH). This dysplasia results from the intracellular retention of mutant COMP protein and premature death of growth-plate chondrocytes. Toward better understanding of these underlying mechanisms, we examined D469del-COMP activation of the unfolded protein response and cell death pathways in rat chondrosarcoma cells. Using an inducible expression system, we examined the effects of D469del-COMP retention after 4 days of mRNA expression and then 5 days without inducing agent. Retention of D469del-COMP stimulated Chop (Ddit3) and Gadd34 (Ppp1r15a) and triggered reactivation of protein translation that exacerbated intracellular retention. High levels of Nox4 and endoplasmic reticulum receptor stress-inducible Ero1β generated reactive oxygen species, causing oxidative stress. Increased expression of Gadd genes and presence of γH2AX indicated that DNA damage was occurring. The presence of cleaved apoptosis inducing factor (tAIF) and the absence of activated caspases indicated that retention of D469del-COMP triggers cell death in chondrocytes by necroptosis, a caspase-independent programmed necrosis. Loss of growth-plate chondrocytes by necroptosis was also found in our pseudoachondroplasia mouse model. These results suggest a model in which D469del-COMP expression induces persistent endoplasmic reticulum stress, oxidative stress, and DNA damage, thus priming chondrocytes for necroptosis. We define for the first time the precise mechanisms underlying D469del-COMP pathology in pseudoachondroplasia and suggest that oxidative stress and AIF may be promising therapeutic targets. PMID:22154936

  19. Development of EST-based SNP and InDel markers and their utilization in tetraploid cotton genetic mapping

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Expressed sequence tags (ESTs) were analyzed in silico in order to identify single nucleotide polymorphisms (SNPs) and insertion-deletion polymorphisms (InDels) in cotton. A total of 1349 EST-based SNP and InDel markers were developed by comparing ESTs between Gossypium hirsutum and G. barbadense, m...

  20. DELIVERING TIMELY AIR QUALITY, TRAFFIC, AND WEATHER INFORMATION TO YOUR COMMUNITY/THE PASO DEL NORTE ENVIRONMENTAL MONITORING PROJECT

    EPA Science Inventory

    EPA has developed a technology transfer handbook for the EMPACT Paso del Norte Project. The EMPACT Paso del Norte Environmental Monitoring Project is a mobile vehicle emissions project that involves the international community of El Paso, TX; Sundland Park, NM; and Juarez, Mexico...

  1. 75 FR 44720 - Safety Zone; Live-Fire Gun Exercise, M/V Del Monte, James River, VA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-29

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Live-Fire Gun Exercise, M/V Del Monte... specified waters of the James River to protect mariners from the hazards associated with live fire and... conduct a live fire and explosive training event onboard the M/V Del Monte in the vicinity of the...

  2. Resultado negativo de prueba del VPH es mejor predictor de riesgo bajo de cáncer de cuello uterino

    Cancer.gov

    De acuerdo con un estudio en el que participaron más de un millón de mujeres, los investigadores del NCI han determinado que el resultado negativo de una prueba para la detección del VPH proporciona mayor certeza o seguridad frente a riesgos futuros de cá

  3. Do crustal deformations observed by GPS in Tierra del Fuego (Argentina) reflect glacial-isostatic adjustment?

    NASA Astrophysics Data System (ADS)

    Mendoza, L.; Richter, A.; Hormaechea, J. L.; Perdomo, R.; Del Cogliano, D.; Dietrich, R.; Fritsche, M.

    2010-09-01

    Vertical site velocities determined by geodetic GPS observations in the Lago Fagnano area, Tierra del Fuego main island, are interpreted with respect to their potential relation with the glacial-isostatic crustal response to ice mass changes. The spatial pattern of the uplift rates, in combination with the horizontal crustal deformation pattern, point towards a fault-tectonic rather than glacial-isostatic origin of the determined vertical crustal deformations. This implies rather small GIA effects pointing towards relatively small Holocene ice-mass changes in Tierra del Fuego. However, these findings are considered to be preliminary. They should be confirmed by additional observations covering an extended area with GPS sites.

  4. Historical survey of the national astronomical observatory in Llano del Hato

    NASA Astrophysics Data System (ADS)

    Martinez Picar, Antonio; Salas Ramirez, Henry

    2007-12-01

    The Centro de Investigaciones de Astronomia (CIDA), the Venezuelan Institute in charge for managing human- and technical resources of the National Astronomical Observatory in Llano del Hato, is one of the younger institutes in its field. However, its foundation is surrounded by a series of curious and interesting eyents that go back to the end of the 18th century. Its equatoriallocation, excellent astronomical equipment and the high-qualified personnel offers a geographical and technical advantage. The paper is a historical oveniew of events, facts and demonstrations of the human activity related to the conception, building and starting the Llano del Hato National Astronomical Observatory.

  5. Archivo de placas astrométricas del Observatorio de La Plata

    NASA Astrophysics Data System (ADS)

    di Sisto, R.; Orellana, R. B.

    Se ha realizado una base de datos con las placas fotográficas obtenidas con el Astrográfico del Observatorio de La Plata. Se han clasificado un total de 3000 placas obtenidas para asteroides y cometas. El acceso a la base de datos se hará por FTP y la misma contendrá la siguiente información: fecha y tiempo de exposición, coordenadas del centro de placa, tipo de emulsión fotográfica, estado de la placa, objeto fotografiado.

  6. A tectonically controlled basin-fill within the Valle del Cauca, West-Central Colombia

    SciTech Connect

    Rine, J.M.; Keith, J.F. Jr.; Alfonso, C.A.; Ballesteros, I.; Laverde, F.; Sacks, P.E.; Secor, D.T. Jr. ); Perez, V.E.; Bernal, I.; Cordoba, F.; Numpaque, L.E. )

    1993-02-01

    Tertiary strata of the Valle del Cauca reflect a forearc/foreland basin tectonic history spanning a period from pre-uplift of the Cordillera Central to initiation of uplift of the Cordillera Occidental. Stratigraphy of the Valle del Cauca begins with Jurassic-Cretaceous rocks of exotic and/or volcanic provenance and of oceanic origin. Unconformably overlying these are Eocene to Oligocene basal quartz-rich sandstones, shallow marine algal limestones, and fine-grained fluvial/deltaic mudstones and sandstones with coalbeds. These Eocene to Oligocene deposits represent a period of low tectonic activity. During late Oligocene to early Miocene, increased tectonic activity produced conglomeratic sediments which were transported from east to west, apparently derived from uplift of the Cordillera Central, and deposited within a fluvial to deltaic setting. East-west shortening of the Valle del Cauca basin folded the Eocene to early Miocene units, and additional uplift of the Cordillera Central during the later Miocene resulted in syn-tectonic deposition of alluvial fans. After additional fold and thrust deformation of the total Eocene-Miocene basin-fill, tectonic activity abated and Pliocene-Quaternary alluvial and lacustrine strata were deposited. Within the framework of this depositional and tectonic history of the Valle del Cauca, hydrocarbon exploration strategies can be formulated and evaluated.

  7. The c.657del5 variant in the NBN gene predisposes to pancreatic cancer.

    PubMed

    Borecka, Marianna; Zemankova, Petra; Lhota, Filip; Soukupova, Jana; Kleiblova, Petra; Vocka, Michal; Soucek, Pavel; Ticha, Ivana; Kleibl, Zdenek; Janatova, Marketa

    2016-08-10

    Pancreatic ductal adenocarcinoma (PDAC) is the sixth most frequent cancer type in the Czech Republic with a poor prognosis that could be improved by an early detection and subsequent surgical treatment combined with chemotherapy. Genetic factors play an important role in PDAC risk. We previously identified one PDAC patient harboring the Slavic founder deleterious mutation c.657del5 in the NBN gene, using a panel next-generation sequencing (NGS). A subsequent analysis of 241 unselected PDAC patients revealed other mutation carriers. The overall frequency of c.657del5 in unselected PDAC patients (5/241; 2.07%) significantly differed from that in non-cancer controls (2/915; 0.2%; P=0.006). The result indicates that the NBN c.657del5 variant represents a novel PDAC-susceptibility allele increasing PDAC risk (OR=9.7; 95% CI: 1.9 to 50.2). The increased risk of PDAC in follow-up recommendations for NBN mutation carriers should be considered if other studies also confirm an increased frequency of c.657del5 carriers in PDAC patients from other populations. PMID:27150568

  8. Calcio y la prevención del cáncer

    Cancer.gov

    Hoja informativa que resume los resultados de estudios sobre el calcio y la prevención del cáncer. Incluye información sobre las recomendaciones dietéticas para calcio y la cantidad de calcio en los alimentos y en complementos de calcio.

  9. 33 CFR 162.35 - Channel of Christina River, Del.; navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Channel of Christina River, Del.; navigation. 162.35 Section 162.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.35 Channel...

  10. 33 CFR 162.35 - Channel of Christina River, Del.; navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Channel of Christina River, Del.; navigation. 162.35 Section 162.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.35 Channel...

  11. 33 CFR 162.35 - Channel of Christina River, Del.; navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Channel of Christina River, Del.; navigation. 162.35 Section 162.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.35 Channel...

  12. 33 CFR 162.35 - Channel of Christina River, Del.; navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Channel of Christina River, Del.; navigation. 162.35 Section 162.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.35 Channel...

  13. 33 CFR 162.35 - Channel of Christina River, Del.; navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Channel of Christina River, Del.; navigation. 162.35 Section 162.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.35 Channel...

  14. Community Arts Programs: Cohesion and Difference Case Studies. Henry Street Settlement and El Museo del Barrio

    ERIC Educational Resources Information Center

    Kiebert-Gruen, Cathleen

    2009-01-01

    A comparative case study of two cultural institutions, Henry Street Settlement and El Museo del Barrio, founded almost eighty years apart, were involved in social justice causes and community arts. Although both of these institutions participated in the political activism of their time, they also demonstrated an important adaptability. They were…

  15. ATMOSPHERIC VOLATILE ORGANIC COMPOUND MEASUREMENTS DURING THE 1996 PASO DEL NORTE OZONE STUDY

    EPA Science Inventory

    Ambient air VOC samples were collected at surface air quality monitoring sites, near sources of interest, and aloft on the US (El Paso) and Mexican (Ciudad Juarez) side of the border during a six-week period of the 1996 Paso del Norte Ozone Study. Samples were collected at five...

  16. Dropouts, Stopouts, Optouts at Del Mar College: Spring 1991. Report of a Joint Research Project.

    ERIC Educational Resources Information Center

    Luckie, Jo Ann I.; Bonham, L. Adrianne

    A research project investigated 2,313 persons who attended Del Mar College (Texas) during fall 1990 but did not enroll for spring 1991. Four sets of data were collected: (1) limited demographic information on the total student body; (2) demographic information drawn from school records to describe all nonreturnees; (3) demographic information…

  17. Dolores Del Rio, the First "Latin Invasion", and Hollywood's Transition to Sound

    ERIC Educational Resources Information Center

    Beltran, Mary

    2005-01-01

    The career and promotion of Mexican actress Dolores Del Rio as a case study of how Hollywood's shift to sound film affected Latino and Latina actors is examined. It reveals the way in which the starring opportunities for Latinos dwindled when accent and language increasingly marked them as nonwhite in the 1930s in the talkie films.

  18. Tratamiento del cáncer sin daño al corazón

    Cancer.gov

    Investigadores de los campos de oncología y de cardiología están trabajando para encontrar formas de impedir, manejar y posiblemente aun revertir los efectos secundarios cardiovasculares de ciertas terapias del cáncer.

  19. Exploración del Nuevo Laboratorio Científico de Marte

    NASA Video Gallery

    Únase a Fernando Abilleira, un analista de trayectoria de la NASA para la Oficina de Exploración de Marte, y conozca las nuevas tecnologías que el nuevo robot Curiosity del Laboratorio Científico d...

  20. Advances in optical technologies at Pontificia Universidad Católica del Perú

    NASA Astrophysics Data System (ADS)

    Baldwin, Guillermo; Asmad, Miguel; Romero, Sandra; Gonzales, Franco; Gálvez, Gonzalo; Sánchez, Rubén; Córdova, Darwin

    2011-05-01

    In this work, it is shown a panoramically view of advances and works on fundamental optical technology developed and Physics Section at Pontificia Universidad Católica del Perú PUCP in Lima Peru. This includes works in, precision optics manufacturing, optical testing, and optical design and simulation and also in optical thin film evaporation and its design techniques

  1. Urban Impact of Dissolved Metals in the Paso del Norte Segment of the Rio Grande

    ERIC Educational Resources Information Center

    Freiwan, Sumayeh Ahmad

    2013-01-01

    The Paso del Norte segment of the Rio Grande experiences two seasons per year; the (wet) irrigation season and the (dry) non-irrigation season. The goal of this study was to improve the understanding of occurrence and contribution of dissolved metals in this region during the non-irrigation season. The objectives of this study were to (1) evaluate…

  2. A Failed Utopia in Marcela Del Río's "Proceso a Faubritten"

    ERIC Educational Resources Information Center

    Manickam, Samuel

    2014-01-01

    In Marcela del Río's science fiction novel "Proceso a Faubritten," utopia comes in the form of eternal life for all of humanity, thanks to Dr. Alexander Faubritten's "Bomba L." This polyphonic work includes diaries by Faubritten and his Mexican lover, María Corona. In my analysis of these two diaries, I will show how…

  3. Se lanza Red Nacional de Estudios Clínicos del NCI

    Cancer.gov

    El Instituto Nacional del Cáncer (NCI) puso en marcha una nueva red de investigación de estudios clínicos con el objetivo de mejorar el tratamiento de más de 1,6 millones de estadounidenses que reciben un diagnóstico de cáncer cada año.

  4. Control del dolor: Apoyo para las personas con cáncer

    Cancer.gov

    Contiene información sobre las medicinas contra el dolor para pacientes con cáncer, los planes para controlarlo, cómo hablar con su equipo de atención médica sobre el dolor que usted siente y qué hacer para controlar los efectos físicos y emocionales del

  5. Interstitial deletion of the long arm of chromosome 2: del(2)(q31q33).

    PubMed

    Al-Awadi, S A; Farag, T I; Naguib, K; Teebi, A; Cuschieri, A; Al-Othman, S; Sundareshan, T S

    1983-12-01

    A child with a de novo interstitial deletion, 46,XX,del(2)(q31q33), is described. Clinical features included psychomotor retardation, hypotonia, microcephaly, hypertelorism, downward slanting palpebral fissures, macrostomia, cleft palate, micrognathia, abnormal ears, overlapping fingers, simian creases, and rocker bottom feet. PMID:6655673

  6. Exploración del Sistema Solar -- Una mirada hacia el futuro

    NASA Video Gallery

    ¿Piensas que ya sabemos todo acerca de nuestro sistema solar? La realidad es que apenas hemos comenzado con lo que hay para conocer. Únete a la NASA, en el envío de misiones a los confines del sist...

  7. Use of del Nido Cardioplegia for Adult Cardiac Surgery at the Cleveland Clinic: Perfusion Implications

    PubMed Central

    Kim, Kuna; Ball, Clifford; Grady, Patrick; Mick, Stephanie

    2014-01-01

    Abstract: Cardiac arrest by cardioplegia provides a reproducible and safe method to induce and maintain electromechanical cardiac quiescence. Techniques of intraoperative myocardial protection are constantly evolving. For the past three decades, modified Buckberg cardioplegia solution has been used for adult cardiac surgery at the Cleveland Clinic. This formulation serves as the crystalloid component, which is delivered 4:1 with oxygenated patient’s blood to crystalloid. Meanwhile, our use of the del Nido cardioplegia solution in adult patients, heretofore primarily used in pediatric cardiac surgical centers, has been increasing over the past several years. Single-dose, cold blood del Nido cardioplegia can be delivered antegrade if the duration of the operation will be limited and if there is no significant coronary artery disease or aortic insufficiency that would limit the distribution of cardioplegia. The addition of del Nido cardioplegia to our cardioplegia armamentarium allows us to customize our myocardial protection strategies for different surgical needs. This article aims to provide information on technical aspects of del Nido cardioplegia in adult cardiac surgery and its use at the Cleveland Clinic in the adult surgical population. PMID:26357803

  8. Fermions tunnelling from 5D general rotating charged Gödel black hole

    NASA Astrophysics Data System (ADS)

    Song, Shi-Xiong; Huang, Jiang; Ren, Ji-Rong

    2011-01-01

    Using the tunneling method we derive the Hawking temperature of the nonextremal rotating charged black hole in the Gödel universe of five-dimensional minimal supergravity theory found by Wu. We successfully recovered the tunneling probability of charged Dirac particles and the expected Hawking temperature of the black hole, which is exactly consistent with that obtained by other methods.

  9. Functional Rescue of F508del-CFTR Using Small Molecule Correctors

    PubMed Central

    Molinski, Steven; Eckford, Paul D. W.; Pasyk, Stan; Ahmadi, Saumel; Chin, Stephanie; Bear, Christine E.

    2012-01-01

    High-throughput screens for small molecules that are effective in “correcting” the functional expression of F508del-CFTR have yielded several promising hits. Two such compounds are currently in clinical trial. Despite this success, it is clear that further advances will be required in order to restore 50% or greater of wild-type CFTR function to the airways of patients harboring the F508del-CFTR protein. Progress will be enhanced by our better understanding of the molecular and cellular defects caused by the F508del mutation, present in 90% of CF patients. The goal of this chapter is to review the current understanding of defects caused by F508del in the CFTR protein and in CFTR-mediated interactions important for its biosynthesis, trafficking, channel function, and stability at the cell surface. Finally, we will discuss the gaps in our knowledge regarding the mechanism of action of existing correctors, the unmet need to discover compounds which restore proper CFTR structure and function in CF affected tissues and new strategies for therapy development. PMID:23055971

  10. Shed Some Light on the Subject: Teaching Ramon del Valle-Inclan's "Luces de bohemia"

    ERIC Educational Resources Information Center

    Parker, Jason Thomas

    2011-01-01

    This essay seeks to provide parallel and interchangeable approaches to teaching Ramon del Valle-Inclan's challenging play "Luces de bohemia". A greater understanding of the cultural and mental frameworks of the early twentieth-century Spanish spectator will permit students to penetrate the dense intertextuality that characterizes Valle's…

  11. Self-consistent Gödel cosmology with spin-density in Riemann-Cartan spacetime

    NASA Astrophysics Data System (ADS)

    Smalley, Larry L.

    1986-01-01

    We show that the Gödel metric for a rotating cosmology is compatible with the self-consistent formulation of the Einstein-Cartan metric-torsion theory for a spinning fluid. Fruitful discussions with J.R. Ray and F.W. Hehl are greatfully acknowledged. I wish to also thank J. Bradas who brought a reference to my attention.

  12. Informe del NCI y los CDC sobre el tabaco sin humo

    Cancer.gov

    El primer informe sobre el consumo mundial del tabaco sin humo y sus consecuencias en la salud pública reveló que más de 300 millones de personas en al menos 70 países usan estos productos dañinos.

  13. Synonymous Codon Usage Affects the Expression of Wild Type and F508del CFTR

    PubMed Central

    Shah, Kalpit; Cheng, Yi; Hahn, Brian; Bridges, Robert; Bradbury, Neil; Mueller, David M.

    2015-01-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel composed of 1480 amino acids. The major mutation responsible for cystic fibrosis results in loss of amino acid residue, F508, (F508del). Loss of F508 in CFTR alters the folding pathway resulting in endoplasmic reticulum associated degradation (ERAD). This study investigates the role of synonymous codon in the expression of CFTR and CFTR F508del in human HEK293 cells. DNA encoding the open reading frame (ORF) for CFTR containing synonymous codon replacements, were expressed using a heterologous vector integrated into the genome. The results indicate that the codon usage greatly affects the expression of CFTR. While the promoter strength driving expression of the ORFs was largely unchanged and the mRNA half-lives were unchanged, the steady state levels of the mRNA varied by as much as 30 fold. Experiments support that this apparent inconsistency is attributed to exon junction complex independent nonsense mediated decay. The ratio of CFTR/mRNA indicates that mRNA containing native codons was more efficient in expressing mature CFTR as compared to mRNA containing synonymous high expression codons. However, when F508del CFTR was expressed after codon optimization, a greater percentage of the protein escaped ERAD resulting in considerable levels of mature F508del CFTR on the plasma membrane, which showed channel activity. These results indicate that for CFTR, codon usage has an effect on mRNA levels, protein expression and likely, for F508del CFTR, chaperone assisted folding pathway. PMID:25676312

  14. Determinacion de periodos fundamentales del suelo mediante vibraciones ambientales en el municipio de Humacao, Puerto Rico

    NASA Astrophysics Data System (ADS)

    Cintron Aponte, Rommel

    La tecnica de Nakamura ha sido utilizada a nivel mundial para determinar periodos fundamentales del suelo. La tecnica consiste en calcular y graficar cocientes espectrales H/V de vibraciones ambientales registradas sobre el suelo. Mediciones de vibraciones ambientales fueron tomadas en 151 lugares dentro del municipio de Humacao, localizado al este de Puerto Rico. Los datos se procesaron utilizando espectros de Fourier y espectros de potencia. La tecnica fue validada al compararla con los resultados de cocientes espectrales H/V de registros de sismos debiles y tambien con una modelacion numerica realizada con datos de un ensayo "downhole". Las graficas de los cocientes espectrales H/V fueron divididas en casos y grupos, los cuales dependen de la facilidad para identificar el periodo fundamental pico y amplitudes en frecuencias menores de 1 Hz, respectivamente. Los resultados obtenidos con ambos espectros fueron comparados y se concluye que los mismos se complementan para proveer resultados mas confiables. Se crearon mapas de periodos fundamentales, factores de amplitud, isoperiodos y clasificacion sismica de sitio. Los mapas de isoperiodos fueron realizados en las zonas mas pobladas sobre depositos de suelo. El mapa de periodos fundamentales del suelo mostro buena correlacion con la geologia local. El mapa de clasificacion sismica derivado de periodos de sitio fue comparado con el mapa de clasificacion sismica derivado de barrenos geotecnicos. El mapa de clasificacion obtenido de periodos puede sobreestimar un poco algunas clasificaciones del suelo. Sin embargo, este mapa puede proveer un estimado aproximado de la velocidad de onda de corte promedio del suelo hasta una profundidad de 100 pies (30 metros).

  15. Toric K3-fibred Calabi-Yau manifolds with del Pezzo divisors for string compactifications

    NASA Astrophysics Data System (ADS)

    Cicoli, Michele; Kreuzer, Maximilian; Mayrhofer, Christoph

    2012-02-01

    We analyse several explicit toric examples of compact K3-fibred Calabi-Yau three-folds. These manifolds can be used for the study of string dualities and are crucial ingredients for the construction of LARGE Volume type IIB vacua with promising applications to cosmology and particle phenomenology. In order to build a phenomenologically viable model, on top of the two moduli corresponding to the base and the K3 fibre, we demand also the existence of two additional rigid divisors: the first supporting the non-perturbative effects needed to achieve moduli stabilisation, and the second allowing the presence of chiral matter on wrapped D-branes. We clarify the topology of these rigid divisors by discussing the interplay between a diagonal structure of the Calabi-Yau volume and D-terms. Del Pezzo divisors appearing in the volume form in a completely diagonal way are natural candidates for supporting non-perturbative effects and for quiver constructions, while `non-diagonal' del Pezzo and rigid but not del Pezzo divisors are particularly interesting for model building in the geometric regime. Searching through the existing list of four dimensional reflexive lattice polytopes, we find 158 examples admitting a Calabi-Yau hypersurface with a K3 fibration and four Kähler moduli where at least one of the toric divisors is a `diagonal' del Pezzo. We work out explicitly the topological details of a few examples showing how, in the case of simplicial polytopes, all the del Pezzo divisors are `diagonal', while `non-diagonal' ones appear only in the case of non-simplicial polytopes. A companion paper will use these results in the study of moduli stabilisation for globally consistent explicit Calabi-Yau compactifications with the local presence of chirality.

  16. Percepcion de los profesores universitarios acerca del concepto cultura cientifica y de sus implicaciones en el nuevo bachillerato del Recinto de Rio Piedras de la Universidad de Puerto Rico

    NASA Astrophysics Data System (ADS)

    Ramos Pastrana, Nilsa

    El Senado Academico del Recinto de Rio Piedras de la Universidad de Puerto Rico aprobo en el ano academico 2005-2006 la Certificacion 46, que contiene los lineamientos de un nuevo bachillerato. Este nuevo bachillerato introdujo cambios significativos en el curriculo tradicional. Entre ellos se encuentra la reduccion del componente de educacion general y el de Ciencias Biologicas en particular. La reduccion de creditos en el componente de Ciencias Biologicas ha obligado a reevaluar el concepto de cultura cientifica que desarrollan esos cursos. El proposito del estudio consistio en auscultar las percepciones de los profesores de las Facultades de Administracion de Empresas, Humanidades, Ciencias Sociales, Ciencias Naturales, Educacion y Estudios Generales del Recinto de Rio Piedras de la Universidad de Puerto Rico en torno al concepto de cultura cientifica, los contenidos disciplinares del curso de Ciencias Biologicas y la reduccion de creditos en el nuevo bachillerato. Las preguntas que guiaron la investigacion fueron: ¿cuales son las percepciones que tienen los profesores de las Facultades de Administracion de Empresas, Ciencias Sociales, Estudios Generales, Ciencias Naturales, Humanidades y Educacion, en torno al concepto de cultura cientifica y los contenidos disciplinares del curso de Ciencias Biologicas? ¿cuales son las percepciones que tienen los profesores de Ciencias Biologicas en torno al concepto cultura cientifica y los contenidos disciplinares del curso de Ciencias Biologicas? ¿existen diferencias significativas por facultad, genero, experiencia, rango y nombramiento en las percepciones que tienen los profesores del Recinto de Rio Piedras de la Universidad de Puerto Rico sobre los elementos que caracterizan la cultura cientifica y los contenidos biologicos que deben tener los egresados del Recinto? ¿que implicaciones curriculares tienen estos testimonios en el desarrollo del concepto de cultura cientifica en el nuevo bachillerato? Para realizar la

  17. Development of InDel markers for Brassica rapa based on whole-genome re-sequencing.

    PubMed

    Liu, Bo; Wang, Yan; Zhai, Wen; Deng, Jie; Wang, Hui; Cui, Yang; Cheng, Feng; Wang, Xiaowu; Wu, Jian

    2013-01-01

    Genome-wide detection of short insertion/deletion length polymorphisms (InDels, <5 bp) in Brassica rapa (named the A genome) was performed by comparing whole-genome re-sequencing data from two B. rapa accessions, L144 and Z16, to the reference genome sequence of Chiifu-401-42. In total, we identified 108,558 InDel polymorphisms between Chiifu-401-42 and L144, 26,795 InDels between Z16 and Chiifu-401-42, and 26,693 InDels between L144 and Z16. From these, 639 InDel polymorphisms of 3-5 bp in length between L144 and Z16 were selected for experimental validation; 491 (77%) yielded single PCR fragments and showed polymorphisms, 7 (1%) did not amplify a product, and 141 (22%) showed no polymorphism. For further validation of these intra-specific InDel polymorphisms, 503 candidates, randomly selected from the 639 InDels, were screened across seven accessions representing different B. rapa cultivar groups. Of these assayed markers, 387 (77%) were polymorphic, 111 (22%) were not polymorphic and 5 (1%) did not amplify a PCR product. Furthermore, we randomly selected 518 InDel markers to validate their polymorphism in B. napus (the AC genome) and B. juncea (the AB genome), of which more than 90% amplified a PCR product; 132 (25%) showed polymorphism between the two B. napus accessions and 41 (8%) between the two B. juncea accessions. This set of novel PCR-based InDel markers will be a valuable resource for genetic studies and breeding programs in B. rapa. PMID:22972202

  18. Thermal unfolding studies show the disease causing F508del mutation in CFTR thermodynamically destabilizes nucleotide-binding domain 1

    PubMed Central

    Protasevich, Irina; Yang, Zhengrong; Wang, Chi; Atwell, Shane; Zhao, Xun; Emtage, Spencer; Wetmore, Diana; Hunt, John F; Brouillette, Christie G

    2010-01-01

    Misfolding and degradation of CFTR is the cause of disease in patients with the most prevalent CFTR mutation, an in-frame deletion of phenylalanine (F508del), located in the first nucleotide-binding domain of human CFTR (hNBD1). Studies of (F508del)CFTR cellular folding suggest that both intra- and inter-domain folding is impaired. (F508del)CFTR is a temperature-sensitive mutant, that is, lowering growth temperature, improves both export, and plasma membrane residence times. Yet, paradoxically, F508del does not alter the fold of isolated hNBD1 nor did it seem to perturb its unfolding transition in previous isothermal chemical denaturation studies. We therefore studied the in vitro thermal unfolding of matched hNBD1 constructs ±F508del to shed light on the defective folding mechanism and the basis for the thermal instability of (F508del)CFTR. Using primarily differential scanning calorimetry (DSC) and circular dichroism, we show for all hNBD1 pairs studied, that F508del lowers the unfolding transition temperature (Tm) by 6–7°C and that unfolding occurs via a kinetically-controlled, irreversible transition in isolated monomers. A thermal unfolding mechanism is derived from nonlinear least squares fitting of comprehensive DSC data sets. All data are consistent with a simple three-state thermal unfolding mechanism for hNBD1 ± F508del: N(±MgATP) ⇄ IT(±MgATP) → AT → (AT)n. The equilibrium unfolding to intermediate, IT, is followed by the rate-determining, irreversible formation of a partially folded, aggregation-prone, monomeric state, AT, for which aggregation to (AT)n and further unfolding occur with no detectable heat change. Fitted parameters indicate that F508del thermodynamically destabilizes the native state, N, and accelerates the formation of AT. PMID:20687133

  19. Estudio del Hidrógeno neutro en dirección al remanente de supernova W28

    NASA Astrophysics Data System (ADS)

    Dubner, G.; Velazquez, P.; Green, A.; Goss, W. M.; Reynoso, E.

    Se presenta un relevamiento del hidrógeno neutro alrededor del remanente de supernova W28 realizado con el radiotelescopio australiano de Parkes. Se analizan rasgos de emisión y absorción. Se muestra la existencia de estructuras anulares asociadas con el remanente. Se compara la distribución del hidrógeno neutro con la ubicación de máseres de OH detectados en la línea de 1720 MHz.

  20. Epidemiological surveillance of ovine hydatidosis in Tierra del Fuego, Patagonia Argentina, 1997-1999.

    PubMed

    Zanini, Fabián; Gonzalo, Roberto; Pérez, Héctor; Aparici, Inés; Soto, Ximena; Guerrero, Juvenal; Cerrone, Gloria; Elissondo, Celina

    2006-06-15

    Cystic echinococcosis is the most prevalent zoonosis in Tierra del Fuego province, Argentina, with important economic, productive and public health consequences. The present work was performed to determine the ovine prevalence in Tierra del Fuego, Argentina, as well as to evaluate the quality of diagnostic systems in slaughterhouses. Moreover, genetic analyses to characterize the strain of Echinococcus granulosus involved in the region were done. The first actions to perform a diagnosis of the epidemiological situation of hydatidosis in Tierra del Fuego were done between 1976 and 1977. A canine prevalence of 80% and an ovine prevalence of 55% results were obtained. Since 1979 the control program of Hydatidosis of Tierra del Fuego was implemented. It was based on semiannual canine anthelmintic treatment with praziquantel at dose of 5mg/kg, and complemented with sanitary education and canine and ovine epidemiological surveillance. During May 1997-January 1999: 5,916 sheep coming from 20 farms of the programmatic area were evaluated. In the lamb category, hydatid cysts were not found. In the adults category, 62 infected animals were found (3.2%). The ovine prevalence was 1.1% and there was 100% of coincidence between diagnosis in the slaughterhouse, re-inspection in the laboratory and histopathological study. The marked decrease in the prevalence observed for sheep infection evidenced a destabilization of the biological cycle of the parasite. This could be explained by the application of a control program with uninterrupted systematic actions. Polymerase chain reaction-ribosomal ITS-1 DNA (rDNA) restriction fragment length polymorphism (PCR-RFLP) analysis and partial sequencing of the mitochondrial cytochrome c oxidase subunit 1 (CO1) gene were used to characterize E. granulosus isolates collected from different regions of Tierra del Fuego to determine which genotypes occurred in this region. The results revealed the presence of the G1 genotype (sheep-dog strain

  1. Medición de densidades medias de meteoritos: test del método de inmersión

    NASA Astrophysics Data System (ADS)

    Steren, G.

    Se evaluó una técnica simple para medir las densidades medias de meteoritos, basada en el Método de Arquímedes y que utiliza cuentas de vidrio de 40μ en lugar de un fluído esto presenta la ventaja de no ser intrusivo ni químicamente reactivo (D.Britt and G.Consolmagno, 1996, B.A.A.S.28,1106). El estudio, realizado en junio de este año por participantes de la VI Escuela de Verano del Observatorio del Vaticano, empleó 37 muestras de la colección del Observatorio del Vaticano, de las cuales 26 eran Condritas, 1 Pallasita y 1 Howardita; algunas de ellas ya habian sido estudiadas por otras técnicas aunque también se incluyeron muestras no estudiadas anteriormente.

  2. 78 FR 6173 - Diana Del Grosso, Ray Smith, Joseph Hatch, Cheryl Hatch, Kathleen Kelley, Andrew Wilklund, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-29

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF TRANSPORTATION Surface Transportation Board Diana Del Grosso, Ray Smith, Joseph Hatch, Cheryl Hatch, Kathleen... Smith, Joseph Hatch, Cheryl Hatch, Kathleen Kelley, Andrew Wilklund, and Richard Kosiba...

  3. del Nido versus St. Thomas Cardioplegia Solutions: A Single-Center Retrospective Analysis of Post Cross-Clamp Defibrillation Rates.

    PubMed

    Buel, Shane T; Striker, Carrie Whittaker; O'Brien, James E

    2016-06-01

    There are many cardioplegia solutions currently in use for pediatric cardiopulmonary bypass (CPB). The most common being del Nido solution. Another common cardioplegia solution used for pediatric CPB is St. Thomas. In October 2014, Children's Mercy Kansas City changed from the use of modified St. Thomas to del Nido. This study compared rates of post cross-clamp fibrillation requiring defibrillation between del Nido solution and modified St. Thomas solution stratified by weight at Children's Mercy Kansas City. This retrospective study consisted of 394 patients who underwent cardiac surgery requiring cardioplegia between January 1, 2014 and July 31, 2015. The outcome measured was defibrillation upon cross-clamp removal. Statistical significance was determined using Fishers exact test with a two-sided significance level of .05. Incidence of defibrillation post cross-clamp removal was 4.4% in the del Nido group and 26.8% in the St. Thomas group (p < .0001). Analysis by weight stratifications displays a reduction in post cross-clamp defibrillation rates in groups using the del Nido solution. The 0- to 6-kg category had an incidence of fibrillation of 1.23% in the del Nido group and 17.5% in the St. Thomas group (p < .0003). The 6- to 15-kg category had an incidence of defibrillation of 1.82% in the del Nido group and 14% in the St. Thomas group (p < .0198). The 15- to 60-kg category had an incidence of defibrillation of 8.9% in the del Nido group and 61% in the St. Thomas group (p < .0001). The >60-kg category had an incidence of defibrillation of 16.7% in the del Nido group and 63% in the St. Thomas group (p < .0623). This study demonstrates a 6-fold decrease in the overall rate of defibrillation post cross-clamp removal between St. Thomas and del Nido cardioplegia solutions. Analyses of weight stratifications demonstrate a decrease in the rate of defibrillation post cross-clamp removal in all categories within the del Nido group. PMID:27578896

  4. DEL RBC transfusion should be avoided in particular blood recipient in East Asia due to allosensitization and ineffectiveness*

    PubMed Central

    Shao, Chao-peng; Wang, Bao-yan; Ye, Shi-hui; Zhang, Wen-li; Xu, Hua; Zhuang, Nai-bao; Wu, Xiao-ying; Xu, Heng-gui

    2012-01-01

    Previously, both primary and secondary anti-D alloimmunizations induced by “Asian type” DEL (RHD1227A allele) were observed in two incidents. We investigated how often these alloimmunization events occur. The transfusions of any D-negative patients were investigated in the First Affiliated Hospital of Xi’an Jiaotong University Medical College, China, during the entire 2009. The antigens of D, C, c, E, and e were routinely serotyped. The “Asian type” DEL variant was genotyped and the RHD heterozygote was determined through two published methods. The changes in anti-D levels were monitored by the indirect antiglobulin test (IAT) and flow cytometry. Thirty D-negative transfused patients were included in the study. We focused on 11 recipients who were transfused with packed red blood cells (RBCs) from DEL donors at least one time. Of those 11 recipients, seven were anti-D negative before transfusion and four were anti-D positive (one patient with an autoantibody). One of the seven pre-transfusion anti-D negative patients produced a primary-response anti-D after being transfused with 400 ml of DEL blood twice. All four pre-transfusion antibody positive patients were not observed hemoglobin (Hb) levels increased, as expected after transfusions. Two patients had an increase in anti-D from 1:8 to 1:64 by IAT, which was also shown by flow cytometry. None of the patients experienced an acute hemolytic episode. Our data indicated that the primary anti-D induced by DEL transfusion or the secondary anti-D elevated by DEL in a truly D-negative patient might not be unusual. We suggest that a truly D-negative childbearing-aged woman should avoid DEL transfusion to protect her from primary anti-D allosensitization. In addition, anti-D positive recipients should also avoid DEL red cell transfusion due to the delayed hemolytic transfusion reaction (DHTR). PMID:23125084

  5. The birth of oligodendrocytes in the anatomical and neuropathological literature: the seminal contribution of Pio del Rio-Hortega. 1921.

    PubMed

    Lassmann, Hans

    2012-01-01

    Comment on: del Río-Hortega P. Glia with very few processes (oligodendroglia). Clin Neuropathol. 2012; 31: 440-459, originally published in Archivos de Neurobiología. 1921; 2: 16-43 and del Río-Hortega P. Are the glia with very few processes homologous with Schwann cells? Clin Neuropathol. 2012; 31: 460-462, originally published in Bol de la Soc Esp de Biol. 1922; X: 25-28. PMID:22943958

  6. La reconstrucción del seno después de una mastectomía

    Cancer.gov

    Hoja informativa que describe la reconstrucción del seno (mama) después de una mastectomía. Contiene información sobre las opciones quirúrgicas, los cuidados de seguimiento y los exámenes de detección del cáncer de seno después de la reconstrucción.

  7. Violación del Principio de Equivalencia en Teorías con Dilatón de Cuerdas

    NASA Astrophysics Data System (ADS)

    Landau, S. J.; Sisterna, P. D.; Vucetich, H.

    Se estudian las violaciones al Principio de Equivalencia en Teorías con Dilatón de Cuerdas. En estos modelos, algunas de las constantes fundamentales dependen del espacio y del tiempo. Se muestra que los experimentos de caída libre no tienen aún precisión como para poner límites a los parámetros de la teoría.

  8. Identification and functional characterisation of a novel KCNJ2 mutation, Val302del, causing Andersen-Tawil syndrome.

    PubMed

    Ördög, Balázs; Hategan, Lidia; Kovács, Mária; Seprényi, György; Kohajda, Zsófia; Nagy, István; Hegedűs, Zoltán; Környei, László; Jost, Norbert; Katona, Márta; Szekeres, Miklós; Forster, Tamás; Papp, Julius Gy; Varró, András; Sepp, Róbert

    2015-07-01

    Loss-of-function mutations of the KCNJ2 gene encoding for the inward rectifier potassium channel subunit Kir2.1 cause Andersen-Tawil Syndrome (ATS), a rare genetic disorder characterised by periodic paralysis, ventricular arrhythmias, and dysmorphic features. Clinical manifestations of the disease appear to vary greatly with the nature of mutation, therefore, functional characterisation of ATS-causing mutations is of clinical importance. In this study, we describe the identification and functional analysis of a novel KCNJ2 mutation, Val302del, identified in a patient with ATS. Heterologously expressed wild type (WT) and Val302del mutant alleles showed similar subcellular distribution of the Kir2.1 protein with high intensity labelling from the membrane region, demonstrating normal membrane trafficking of the Val302del Kir2.1 variant. Cells transfected with the WT allele displayed a robust current with strong inward rectification, while no current above background was detected in cells expressing the Val302del Kir2.1 subunit. Co-transfection of CHO cells with the WT and the Val302del Kir2.1 revealed a dose-dependent inhibitory effect of the Val302del Kir2.1 mutant subunit on WT Kir2.1 currents. These observations indicate that the WT and the Val302del mutant subunits co-assemble in the cell membrane and that the mutation affects potassium conductivity and (or) gating of the WT/Val302del heteromeric Kir2.1 channels. PMID:26103554

  9. ∆ DNMT3B4-del Contributes to Aberrant DNA Methylation Patterns in Lung Tumorigenesis

    PubMed Central

    Ma, Mark Z.; Lin, Ruxian; Carrillo, José; Bhutani, Manisha; Pathak, Ashutosh; Ren, Hening; Li, Yaokun; Song, Jiuzhou; Mao, Li

    2015-01-01

    Aberrant DNA methylation is a hallmark of cancer but mechanisms contributing to the abnormality remain elusive. We have previously shown that ∆DNMT3B is the predominantly expressed form of DNMT3B. In this study, we found that most of the lung cancer cell lines tested predominantly expressed DNMT3B isoforms without exons 21, 22 or both 21 and 22 (a region corresponding to the enzymatic domain of DNMT3B) termed DNMT3B/∆DNMT3B-del. In normal bronchial epithelial cells, DNMT3B/ΔDNMT3B and DNMT3B/∆DNMT3B-del displayed equal levels of expression. In contrast, in patients with non-small cell lung cancer NSCLC), 111 (93%) of the 119 tumors predominantly expressed DNMT3B/ΔDNMT3B-del, including 47 (39%) tumors with no detectable DNMT3B/∆DNMT3B. Using a transgenic mouse model, we further demonstrated the biological impact of ∆DNMT3B4-del, the ∆DNMT3B-del isoform most abundantly expressed in NSCLC, in global DNA methylation patterns and lung tumorigenesis. Expression of ∆DNMT3B4-del in the mouse lungs resulted in an increased global DNA hypomethylation, focal DNA hypermethylation, epithelial hyperplastia and tumor formation when challenged with a tobacco carcinogen. Our results demonstrate ∆DNMT3B4-del as a critical factor in developing aberrant DNA methylation patterns during lung tumorigenesis and suggest that ∆DNMT3B4-del may be a target for lung cancer prevention. PMID:26629529

  10. Estimaciones de Prevalencia del VIH por Género y Grupo de Riesgo en Tijuana, México: 2006

    PubMed Central

    Iñiguez-Stevens, Esmeralda; Brouwer, Kimberly C.; Hogg, Robert S.; Patterson, Thomas L.; Lozada, Remedios; Magis-Rodriguez, Carlos; Elder, John P.; Viani, Rolando M.; Strathdee, Steffanie A.

    2010-01-01

    OBJETIVO Estimar la prevalencia del VIH en adultos de 15-49 años de edad en Tijuana, México - en la población general y en subgrupos de riesgo en el 2006. METODOS Se obtuvieron datos demográficos del censo Mexicano del 2005, y la prevalencia del VIH se obtuvo de la literatura. Se construyó un modelo de prevalencia del VIH para la población general y de acuerdo al género. El análisis de sensibilidad consistió en estimar errores estándar del promedio-ponderado de la prevalencia del VIH y tomar derivados parciales con respecto a cada parámetro. RESULTADOS La prevalencia del VIH es 0.54%(N = 4,347) (Rango: 0.22%–0.86%, (N = 1,750–6,944)). Esto sugiere que 0.85%(Rango: 0.39%–1.31%) de los hombres y 0.22%(Rango: 0.04%–0.40%) de las mujeres podrían ser VIH-positivos. Los hombres que tienen sexo con hombres (HSH), las trabajadoras sexuales usuarias de drogas inyectables (MTS-UDI), MTS-noUDI, mujeres UDI, y los hombres UDI contribuyeron las proporciones más elevadas de personas infectadas por el VIH. CONCLUSIONES El número de adultos VIH-positivos entre subgrupos de riesgo en la población de Tijuana es considerable, marcando la necesidad de enforcar las intervenciones de prevención en sus necesidades específicas. El presente modelo estima que hasta 1 en cada 116 adultos podrían ser VIH-positivos. PMID:19685824

  11. PREVENCIÓN DEL VIH/SIDA EN LOS CIRCUITOS DE LEVANTE HSH: UNA ASIGNATURA PENDIENTE.

    PubMed

    Barreda, Victoria; Carballo-Dieguez, Alex; Marone, Rubén; Balán, Iván; Pando, María Ángeles; Avila, María Mercedes

    2010-12-01

    A partir de un relevamiento de tipo etnográfico, se describen lugares de encuentro de HSH en la Ciudad de Buenos Aires y sus prácticas sexuales. El reconocimiento de tales espacios, así como las características que asumen en ellos los encuentros sexuales entre los HSH, plantean obstáculos específicos en la adopción de comportamientos preventivos y, asimismo, generan nuevos desafíos para las actividades de prevención. Se plantean las dificultades y debates conceptuales que la misma categoría presenta, y sus consecuencias en el abordaje preventivo y teórico-metodológico para las ciencias sociales. Además, se proponen nuevos interrogantes acerca de los alcances y las limitaciones del modelo preventivo del VIH/Sida para HSH. PMID:21874154

  12. Ectrodactyly and tetralogy of Fallot in a fetus with del(6)(q21q23).

    PubMed

    Novikova, I V; Lazarevich, A A; Egorova, T M; Solovyeva, I V; Golovataja, E I; Plevako, T A; Mikheeva, N G; Lurie, I W

    2014-01-01

    We report a fetus with del(6)(q21q23) who had tetralogy of Fallot and ectrodactyly of the right hand. Analysis of the literature showed that both these defects were reported in several patients with similar deletions. The minimal segment responsible for ectrodactyly may be limited to 7.35 Mb (106.650.000-114.600.000). However 1) significant number of patients with this deletion but without ectrodactyly or other defects of extremities, and 2) wide range of unusual birth defects in some persons with deletions of the critical segment allow to propose involvement of regulatory element(s) necessary for the occurrence of ectrodactyly in patients with del 6q21. PMID:24783651

  13. Correction of F508del CFTR in airway epithelium using nanoparticles delivering triplex-forming PNAs

    PubMed Central

    McNeer, Nicole Ali; Anandalingam, Kavitha; Fields, Rachel J.; Caputo, Christina; Kopic, Sascha; Gupta, Anisha; Quijano, Elias; Polikoff, Lee; Kong, Yong; Bahal, Raman; Geibel, John P; Glazer, Peter M.; Saltzman, W. Mark; Egan, Marie E.

    2015-01-01

    Cystic fibrosis (CF) is a lethal genetic disorder most commonly caused by the F508del mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. It is not readily amenable to gene therapy because of its systemic nature and challenges including in vivo gene delivery and transient gene expression. Here, we use triplex-forming PNA molecules and donor DNA in biodegradable polymer nanoparticles to correct F508del. We confirm modification with sequencing and a functional chloride efflux assay. In vitro correction of chloride efflux occurs in up to 25% of human cells. Deep sequencing reveals negligible off-target effects in partially homologous sites. Intranasal application of nanoparticles in CF mice produces changes in nasal epithelium potential differences consistent with corrected CFTR, with gene correction also detected in lung tissue. This work represents facile genome engineering in vivo with oligonucleotides using a nanoparticle system to achieve clinically relevant levels of gene editing without off-target effects. PMID:25914116

  14. Lumacaftor/ivacaftor combination for cystic fibrosis patients homozygous for Phe508del-CFTR.

    PubMed

    Zhang, W; Zhang, X; Zhang, Y H; Strokes, D C; Naren, A P

    2016-04-01

    Cystic fibrosis (CF) is a life-shortening inherited disease caused by the loss or dysfunction of the CF transmembrane conductance regulator (CFTR) channel activity resulting from mutations in the CFTR gene. Phe508del is the most prevalent mutation, with approximately 90% of all CF patients carrying it on at least one allele. Over the past two or three decades, significant progress has been made in understanding the pathogenesis of CF, and in the development of effective CF therapies. The approval of Orkambi® (lumacaftor/ivacaftor) marks another milestone in CF therapeutics development, which, with the advent of personalized medicine, could potentially revolutionize CF care and management. This article reviews the rationale, progress and future direction in the development of lumacaftor/ivacaftor combination to treat CF patients homozygous for the Phe508del-CFTR mutation. PMID:27252987

  15. Informe trata el descenso del cáncer y los tumores cerebrales

    Cancer.gov

    Los índices de mortalidad en los Estados Unidos de todos los cánceres en hombres y mujeres siguieron bajando entre 2003 y 2007, que es el período más reciente del que se disponen datos, según el último Informe Anual a la Nación sobre el Estado del Cáncer. El informe encuentra también que el índice general combinado de nuevos diagnósticos de cáncer en hombres y mujeres decreció un promedio un poco menos de 1% por año en el mismo período.

  16. Antagonistic effects of IL-17 and D-resolvins on endothelial Del-1 expression through a GSK-3β-C/EBPβ pathway.

    PubMed

    Maekawa, Tomoki; Hosur, Kavita; Abe, Toshiharu; Kantarci, Alpdogan; Ziogas, Athanasios; Wang, Baomei; Van Dyke, Thomas E; Chavakis, Triantafyllos; Hajishengallis, George

    2015-01-01

    Del-1 is an endothelial cell-secreted anti-inflammatory protein. In humans and mice, Del-1 expression is inversely related to that of IL-17, which inhibits Del-1 through hitherto unidentified mechanism(s). Here we show that IL-17 downregulates human endothelial cell expression of Del-1 by targeting a critical transcription factor, C/EBPβ. Specifically, IL-17 causes GSK-3β-dependent phosphorylation of C/EBPβ, which is associated with diminished C/EBPβ binding to the Del-1 promoter and suppressed Del-1 expression. This inhibitory action of IL-17 can be reversed at the GSK-3β level by PI3K/Akt signalling induced by D-resolvins. The biological relevance of this regulatory network is confirmed in a mouse model of inflammatory periodontitis. Intriguingly, resolvin-D1 (RvD1) confers protection against IL-17-driven periodontal bone loss in a Del-1-dependent manner, indicating an RvD1-Del-1 axis against IL-17-induced pathological inflammation. The dissection of signalling pathways regulating Del-1 expression provides potential targets to treat inflammatory diseases associated with diminished Del-1 expression, such as periodontitis and multiple sclerosis. PMID:26374165

  17. Antagonistic effects of IL-17 and D-resolvins on endothelial Del-1 expression through a GSK-3β-C/EBPβ pathway

    PubMed Central

    Maekawa, Tomoki; Hosur, Kavita; Abe, Toshiharu; Kantarci, Alpdogan; Ziogas, Athanasios; Wang, Baomei; Van Dyke, Thomas E.; Chavakis, Triantafyllos; Hajishengallis, George

    2015-01-01

    Del-1 is an endothelial cell-secreted anti-inflammatory protein. In humans and mice, Del-1 expression is inversely related to that of IL-17, which inhibits Del-1 through hitherto unidentified mechanism(s). Here we show that IL-17 downregulates human endothelial cell expression of Del-1 by targeting a critical transcription factor, C/EBPβ. Specifically, IL-17 causes GSK-3β-dependent phosphorylation of C/EBPβ, which is associated with diminished C/EBPβ binding to the Del-1 promoter and suppressed Del-1 expression. This inhibitory action of IL-17 can be reversed at the GSK-3β level by PI3K/Akt signalling induced by D-resolvins. The biological relevance of this regulatory network is confirmed in a mouse model of inflammatory periodontitis. Intriguingly, resolvin-D1 (RvD1) confers protection against IL-17-driven periodontal bone loss in a Del-1-dependent manner, indicating an RvD1-Del-1 axis against IL-17-induced pathological inflammation. The dissection of signalling pathways regulating Del-1 expression provides potential targets to treat inflammatory diseases associated with diminished Del-1 expression, such as periodontitis and multiple sclerosis. PMID:26374165

  18. Sanger Sequencing for BRCA1 c.68_69del, BRCA1 c.5266dup and BRCA2 c.5946del Mutation Screen on Pap Smear Cytology Samples

    PubMed Central

    Lee, Sin Hang; Zhou, Shaoxia; Zhou, Tianjun; Hong, Guofan

    2016-01-01

    Three sets of polymerase chain reaction (PCR) primers were designed for heminested PCR amplification of the target DNA fragments in the human genome which include the site of BRCA1 c.68_69del, BRCA1 c.5266dup and BRCA2 c.5946del respectively, to prepare the templates for direct Sanger sequencing screen of these three founder mutations. With a robust PCR mixture, crude proteinase K digestate of the fixed cervicovaginal cells in the liquid-based Papanicolaou (Pap) cytology specimens can be used as the sample for target DNA amplification without pre-PCR DNA extraction, purification and quantitation. The post-PCR products can be used directly as the sequencing templates without further purification or quantitation. By simplifying the frontend procedures for template preparation, the cost for screening these three founder mutations can be reduced to about US $200 per test when performed in conjunction with human papillomavirus (HPV) assays now routinely ordered for cervical cancer prevention. With this projected price structure, selective patients in a high-risk population can be tested and each provided with a set of DNA sequencing electropherograms to document the absence or presence of these founder mutations in her genome to help assess inherited susceptibility to breast and ovarian cancer in this era of precision molecular personalized medicine. PMID:26867194

  19. Sanger Sequencing for BRCA1 c.68_69del, BRCA1 c.5266dup and BRCA2 c.5946del Mutation Screen on Pap Smear Cytology Samples.

    PubMed

    Lee, Sin Hang; Zhou, Shaoxia; Zhou, Tianjun; Hong, Guofan

    2016-01-01

    Three sets of polymerase chain reaction (PCR) primers were designed for heminested PCR amplification of the target DNA fragments in the human genome which include the site of BRCA1 c.68_69del, BRCA1 c.5266dup and BRCA2 c.5946del respectively, to prepare the templates for direct Sanger sequencing screen of these three founder mutations. With a robust PCR mixture, crude proteinase K digestate of the fixed cervicovaginal cells in the liquid-based Papanicolaou (Pap) cytology specimens can be used as the sample for target DNA amplification without pre-PCR DNA extraction, purification and quantitation. The post-PCR products can be used directly as the sequencing templates without further purification or quantitation. By simplifying the frontend procedures for template preparation, the cost for screening these three founder mutations can be reduced to about US $200 per test when performed in conjunction with human papillomavirus (HPV) assays now routinely ordered for cervical cancer prevention. With this projected price structure, selective patients in a high-risk population can be tested and each provided with a set of DNA sequencing electropherograms to document the absence or presence of these founder mutations in her genome to help assess inherited susceptibility to breast and ovarian cancer in this era of precision molecular personalized medicine. PMID:26867194

  20. Correction of the F508del-CFTR protein processing defect in vitro by the investigational drug VX-809.

    PubMed

    Van Goor, Fredrick; Hadida, Sabine; Grootenhuis, Peter D J; Burton, Bill; Stack, Jeffrey H; Straley, Kimberly S; Decker, Caroline J; Miller, Mark; McCartney, Jason; Olson, Eric R; Wine, Jeffrey J; Frizzell, Ray A; Ashlock, Melissa; Negulescu, Paul A

    2011-11-15

    Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene that impair the function of CFTR, an epithelial chloride channel required for proper function of the lung, pancreas, and other organs. Most patients with CF carry the F508del CFTR mutation, which causes defective CFTR protein folding and processing in the endoplasmic reticulum, resulting in minimal amounts of CFTR at the cell surface. One strategy to treat these patients is to correct the processing of F508del-CFTR with small molecules. Here we describe the in vitro pharmacology of VX-809, a CFTR corrector that was advanced into clinical development for the treatment of CF. In cultured human bronchial epithelial cells isolated from patients with CF homozygous for F508del, VX-809 improved F508del-CFTR processing in the endoplasmic reticulum and enhanced chloride secretion to approximately 14% of non-CF human bronchial epithelial cells (EC(50), 81 ± 19 nM), a level associated with mild CF in patients with less disruptive CFTR mutations. F508del-CFTR corrected by VX-809 exhibited biochemical and functional characteristics similar to normal CFTR, including biochemical susceptibility to proteolysis, residence time in the plasma membrane, and single-channel open probability. VX-809 was more efficacious and selective for CFTR than previously reported CFTR correctors. VX-809 represents a class of CFTR corrector that specifically addresses the underlying processing defect in F508del-CFTR. PMID:21976485

  1. Correction of the F508del-CFTR protein processing defect in vitro by the investigational drug VX-809

    PubMed Central

    Van Goor, Fredrick; Hadida, Sabine; Grootenhuis, Peter D. J.; Burton, Bill; Stack, Jeffrey H.; Straley, Kimberly S.; Decker, Caroline J.; Miller, Mark; McCartney, Jason; Olson, Eric R.; Wine, Jeffrey J.; Frizzell, Ray A.; Ashlock, Melissa; Negulescu, Paul A.

    2011-01-01

    Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene that impair the function of CFTR, an epithelial chloride channel required for proper function of the lung, pancreas, and other organs. Most patients with CF carry the F508del CFTR mutation, which causes defective CFTR protein folding and processing in the endoplasmic reticulum, resulting in minimal amounts of CFTR at the cell surface. One strategy to treat these patients is to correct the processing of F508del-CFTR with small molecules. Here we describe the in vitro pharmacology of VX-809, a CFTR corrector that was advanced into clinical development for the treatment of CF. In cultured human bronchial epithelial cells isolated from patients with CF homozygous for F508del, VX-809 improved F508del-CFTR processing in the endoplasmic reticulum and enhanced chloride secretion to approximately 14% of non-CF human bronchial epithelial cells (EC50, 81 ± 19 nM), a level associated with mild CF in patients with less disruptive CFTR mutations. F508del-CFTR corrected by VX-809 exhibited biochemical and functional characteristics similar to normal CFTR, including biochemical susceptibility to proteolysis, residence time in the plasma membrane, and single-channel open probability. VX-809 was more efficacious and selective for CFTR than previously reported CFTR correctors. VX-809 represents a class of CFTR corrector that specifically addresses the underlying processing defect in F508del-CFTR. PMID:21976485

  2. [The Accademia dei Lincei (1603-1630) and the Accademia del Cimento (1657-1667].

    PubMed

    Mazzolini, Renato G

    2008-01-01

    The development of scientific academies during the 17th century in the old Italian States is illustrated on the basis of two examples: that of the Accademia dei Lincei with seat in Rome and that of the Accademia del Cimento with seat in the Grand Duchy of Tuscany. After a short survey of their activities follow some reflections on the causes of their ending. PMID:20617611

  3. Impact of Observing Parameters on 17 Nights with Nova Del 2013

    NASA Astrophysics Data System (ADS)

    Green, Wayne L.

    2014-05-01

    Nova Del 2013 was reported in Astronomer's Telegram #5279 (PNV 20233073+2046041) on 2013 Aug. 14. On the following day, the University of Colorado, Boulder granted our observing request for use of the R3000-5000 spectrograph attached to the their 60-cm telescope. The planning, operational approach, analysis techniques, results, issues, and operational conclusions for data taken from 15 August through 2 September are reported here.

  4. Deep source model for Nevado del Ruiz Volcano, Colombia, constrained by interferometric synthetic aperture radar observations

    NASA Astrophysics Data System (ADS)

    Lundgren, P.; Samsonov, S. V.; López, C. M.; Ordoñez, M.

    2015-12-01

    Nevado del Ruiz (NRV) is part of a large volcano complex in the northern Andes of Colombia with a large glacier that erupted in 1985, generating a lahar killing over 23,000 people in the city of Armero and 2,000 people in the town of Chinchina. NRV is the most active volcano in Colombia and since 2012 has generated small eruptions, with no casualties, and constant gas and ash emissions. Interferometric synthetic aperture radar (InSAR) observations from ascending and descending track RADARSAT-2 data show a large (>20 km) wide inflation pattern apparently starting in late 2011 to early 2012 and continuing to the time of this study in early 2015 at a LOS rate of over 3-4 cm/yr (Fig. 1). Volcano pressure volume models for both a point source (Mogi) and a spheroidal (Yang) source find solutions over 14 km beneath the surface, or 10 km below sea level, and centered 10 km to the SW of Nevado del Ruiz volcano. The spheroidal source has a roughly horizontal long axis oriented parallel to the Santa Isabel - Nevado del Ruiz volcanic line and perpendicular to the ambient compressive stress direction. Its solution provides a statistically significant improvement in fit compared to the point source, though consideration of spatially correlated noise sources may diminish this significance. Stress change computations do not favor one model over the other but show that propagating dikes would become trapped in sills, leading to a more complex pathway to the surface and possibly explaining the significant lateral distance between the modeled sources and Nevado del Ruiz volcano.

  5. Mach, Thirring & Lense, Gödel getting dizzy in space-time

    NASA Astrophysics Data System (ADS)

    Embacher, Franz

    2007-11-01

    Contrary to Newton's concept of inertia, general relativity predicts an influence of rotating matter on the structure of space and time. Anticipated by Ernst Mach, effects of this type have first been derived by Hans Thirring and Josef Lense. Almost ninety years later, we face their experimental verification. An even more dramatic scenario is provided by Kurt Gödel's cosmological model, in which nearby observers rotate with respect to each other and are free to travel to their own past.

  6. Pío del Río Hortega and the discovery of the oligodendrocytes

    PubMed Central

    Pérez-Cerdá, Fernando; Sánchez-Gómez, María Victoria; Matute, Carlos

    2015-01-01

    Pío del Río Hortega (1882–1945) discovered microglia and oligodendrocytes (OLGs), and after Ramón y Cajal, was the most prominent figure of the Spanish school of neurology. He began his scientific career with Nicolás Achúcarro from whom he learned the use of metallic impregnation techniques suitable to study non-neuronal cells. Later on, he joined Cajal’s laboratory. and Subsequently, he created his own group, where he continued to develop other innovative modifications of silver staining methods that revolutionized the study of glial cells a century ago. He was also interested in neuropathology and became a leading authority on Central Nervous System (CNS) tumors. In parallel to this clinical activity, del Río Hortega rendered the first systematic description of a major polymorphism present in a subtype of macroglial cells that he named as oligodendroglia and later OLGs. He established their ectodermal origin and suggested that they built the myelin sheath of CNS axons, just as Schwann cells did in the periphery. Notably, he also suggested the trophic role of OLGs for neuronal functionality, an idea that has been substantiated in the last few years. Del Río Hortega became internationally recognized and established an important neurohistological school with outstanding pupils from Spain and abroad, which nearly disappeared after his exile due to the Spanish civil war. Yet, the difficulty of metal impregnation methods and their variability in results, delayed for some decades the confirmation of his great insights into oligodendrocyte biology until the development of electron microscopy and immunohistochemistry. This review aims at summarizing the pioneer and essential contributions of del Río Hortega to the current knowledge of oligodendrocyte structure and function, and to provide a hint of the scientific personality of this extraordinary and insufficiently recognized man. PMID:26217196

  7. Lenalidomide induces ubiquitination and degradation of CK1α in del(5q) MDS.

    PubMed

    Krönke, Jan; Fink, Emma C; Hollenbach, Paul W; MacBeth, Kyle J; Hurst, Slater N; Udeshi, Namrata D; Chamberlain, Philip P; Mani, D R; Man, Hon Wah; Gandhi, Anita K; Svinkina, Tanya; Schneider, Rebekka K; McConkey, Marie; Järås, Marcus; Griffiths, Elizabeth; Wetzler, Meir; Bullinger, Lars; Cathers, Brian E; Carr, Steven A; Chopra, Rajesh; Ebert, Benjamin L

    2015-07-01

    Lenalidomide is a highly effective treatment for myelodysplastic syndrome (MDS) with deletion of chromosome 5q (del(5q)). Here, we demonstrate that lenalidomide induces the ubiquitination of casein kinase 1A1 (CK1α) by the E3 ubiquitin ligase CUL4-RBX1-DDB1-CRBN (known as CRL4(CRBN)), resulting in CK1α degradation. CK1α is encoded by a gene within the common deleted region for del(5q) MDS and haploinsufficient expression sensitizes cells to lenalidomide therapy, providing a mechanistic basis for the therapeutic window of lenalidomide in del(5q) MDS. We found that mouse cells are resistant to lenalidomide but that changing a single amino acid in mouse Crbn to the corresponding human residue enables lenalidomide-dependent degradation of CK1α. We further demonstrate that minor side chain modifications in thalidomide and a novel analogue, CC-122, can modulate the spectrum of substrates targeted by CRL4(CRBN). These findings have implications for the clinical activity of lenalidomide and related compounds, and demonstrate the therapeutic potential of novel modulators of E3 ubiquitin ligases. PMID:26131937

  8. Lenalidomide induces ubiquitination and degradation of CK1α in del(5q) MDS

    PubMed Central

    Hollenbach, Paul W.; MacBeth, Kyle J.; Hurst, Slater N.; Udeshi, Namrata D.; Chamberlain, Philip P.; Mani, D.R.; Man, Hon Wah; Gandhi, Anita K.; Svinkina, Tanya; Schneider, Rebekka K.; McConkey, Marie; Järås, Marcus; Griffiths, Elizabeth; Wetzler, Meir; Bullinger, Lars; Cathers, Brian E.; Carr, Steven A.; Chopra, Rajesh; Ebert, Benjamin L.

    2015-01-01

    Summary Lenalidomide is a highly effective treatment for myelodysplastic syndrome (MDS) with deletion of chromosome 5q (del(5q)). Here, we demonstrate that lenalidomide induces the ubiquitination of casein kinase 1A1 (CK1α) by the CRL4CRBN E3 ubiquitin ligase, resulting in CK1α degradation. CK1α is encoded by a gene within the common deleted region for del(5q) MDS and haploinsufficient expression sensitizes cells to lenalidomide therapy, providing a mechanistic basis for lenalidomide's therapeutic window in del(5q) MDS. We found that mouse cells are resistant to lenalidomide but that changing a single amino acid in mouse Crbn to the corresponding human residue enables lenalidomide-dependent degradation of CK1α. We further demonstrate that minor side chain modifications in thalidomide and a novel analogue, CC-122, can modulate the spectrum of substrates targeted by CRL4CRBN. These findings have implications for the clinical activity of lenalidomide and related compounds and demonstrate the therapeutic potential of novel modulators of E3 ubiquitin ligases. PMID:26131937

  9. Lenalidomide for myelodysplastic syndromes with del(5q): how long should it last?

    PubMed

    Vozella, Federico; Latagliata, Roberto; Carmosino, Ida; Volpicelli, Paola; Montagna, Chiara; Romano, Angela; Roberto, Amanda; Finsinger, Paola; Mancini, Marco; Breccia, Massimo; Oliva, Esther; Oliva, Esther

    2015-03-01

    Lenalidomide induces in patients with myelodysplastic syndrome (MDS) and del(5q) erythroid and cytogenetic response rates as high as 75% and 50%, respectively. It is still unclear, however, how long lenalidomide treatment should be continued and whether or not the drug could be interrupted. To assess the feasibility of lenalidomide discontinuation, we revised a cohort of 16 low-risk MDS patients with del(5q) treated at our institute in a phase II multicentric Italian study. Among the 12 responding patients, four discontinued lenalidomide while in complete response. All four patients needed during treatment a permanent lenalidomide reduction from 10 to 5 mg/day because of haematological toxicity (three patients) or grade 3 muscular and bone pain (one patient). At lenalidomide discontinuation after 16, 20, 27 and 20 months from the start, respectively, all four patients were in complete hematologic response and three forth in complete cytogenetic response. Three patients are still in response after 36, 30 and 20 months from lenalidomide discontinuation, respectively: The remaining patient relapsed after 20 months, and she is now receiving a new course of lenalidomide. In conclusion, long-lasting remissions are achievable in MDS patients with del(5q) in complete response after lenalidomide discontinuation. PMID:25950027

  10. Variation in mangrove forest structure and sediment characteristics in Bocas del Toro, Panama

    USGS Publications Warehouse

    Lovelock, C.E.; Feller, Ilka C.; McKee, K.L.; Thompson, R.

    2005-01-01

    Mangrove forest structure and sediment characteristics were examined in the extensive mangroves of Bocas del Toro, Republic of Panama. Forest structure was characterized to determine if spatial vegetation patterns were repeated over the Bocas del Toro landscape. Using a series of permanent plots and transects we found that the forests of Bocas del Toro were dominated by Rhizophora mangle with very few individuals of Avicennia germinans and Laguncularia racemosa. Despite this low species diversity, there was large variation in forest structure and in edaphic conditions (salinity, concentration of available phosphorus, Eh and sulphide concentration). Aboveground biomass varied 20-fold, from 6.8 Mg ha-1 in dwarf forests to 194.3 Mg ha-1 in the forests fringing the land. But variation in forest structure was predictable across the intertidal zone. There was a strong tree height gradient from seaward fringe (mean tree height 3.9 m), decreasing in stature in the interior dwarf forests (mean tree height 0.7 m), and increasing in stature in forests adjacent to the terrestrial forest (mean tree height 4.1 m). The predictable variation in forest structure emerges due to the complex interactions among edaphic and plant factors. Identifying predictable patterns in forest structure will aid in scaling up the ecosystem services provided by mangrove forests in coastal landscapes. Copyright 2005 College of Arts and Sciences.

  11. Digitalización de diapositivas del Sol en H α

    NASA Astrophysics Data System (ADS)

    Missio, H.; Montenegro, C.; Montenegro, R.

    El objetivo de este trabajo ha sido el de obtener imágenes digitalizadas de las diapositivas tomadas del Sol en luz de hidrógeno de la línea correspondiente a Hα, y de esta manera llegar a convertir las mismas a un archivo digital para poder ser tratadas luego por computadora y poder contabilizar con exactitud, mediante un programa adecuado para tal fin, las zonas activas del Sol en la imagen digitalizada. En principio, para llegar a esto se pensó en la utilización de medios accesibles, y como detector se utilizó un fototransistor ubicado dentro de un soporte rectangular sobre dos ejes de desplazamiento X e Y. Se han obtenido con este procedimiento imágenes de buena calidad, construídas a partir de tres datos digitalizados en cada barrido que aportan la posición X e Y y la intensidad del pixel en ese punto indicada en 255 tonos de grises.

  12. Campano-Maastrichtian foraminifera from onshore sediments in the Rio del Rey Basin, Southwest Cameroon

    NASA Astrophysics Data System (ADS)

    Njoh, Oliver Anoh; Victor, Obiosio; Christopher, Agyingi

    2013-03-01

    Campanian-Maastrichtian marine sediments outcrop in five genetically linked sedimentary basins along the West African coast in the Gulf of Guinea, from the Douala Basin in Cameroon to the Anambra Basin in Nigeria. These sediments in the more centrally located Rio del Rey Basin have been the least studied. Therefore, the geologic history of this region has merely been speculative. The Rio del Rey Basin like the adjacent Niger Delta is producing hydrocarbon from the offshore Tertiary sedimentary interval in which all studies have been focused, neglecting the onshore Cretaceous sediments. Outcrops in the basin are rare, small and highly weathered. Samples from some of these sediments have yielded a few Planktonic and dominantly benthonic foraminiferal assemblages. The long-ranging heterohelix and hedbergellids characterized the planktics while the species Afrobolivina afra which is a well known diagnostic taxon for Campanian-Maastrichtian sediments in West African basins clearly dominate the benthic assemblage. Its occurrence in association with other Upper Cretaceous forms such as Bolivina explicata, Praebulimina exiqua, Gabonita lata, Ammobaculites coprolithiformis amongst others, formed the basis on which this age was assigned to the sediments sampled from the Rio del Rey Basin. Hence, this work has undoubtedly established the much needed link in this regional geologic history and correlates these sediments with the Logbaba and Nkporo Formations in the Douala Basin in Cameroon and the southeastern Nigerian Sedimentary Basins. Thus, these units were all deposited during this same geologic period and probably controlled by the same geologic event.

  13. Experience the magic of light and color: outreach activity by Universidad del Valle student chapter

    NASA Astrophysics Data System (ADS)

    Valdes, Claudia; Reyes, Camilo; Osorio, Alberto; Solarte, Efrain

    2010-08-01

    During 2007, the Universidad del Valle Student Chapter presented a proposal for developing an educational outreach activity for children from an underprivileged zone to the Optical Society of America Foundation (OSAF) and to SPIE. The activity was carried out jointly by OSA and SPIE Universidad del Valle Student Chapters in the hillsides of Santiago de Cali, in a zone known as "Pueblo Joven" during 2008. It was aimed to boys and girls with ages between 8 and 13 years and was called "Experience the magic of light and color". The main purpose was to bring the children some basic concepts on optics and to encourage them to explore science through optics. The Universidad del Valle Student Chapters designed a series of talks and practical workshops where children participated in hands-on experiments that easily explain the fundamental concepts of light phenomena. Afterwards the children presented their achievements in a small science fair offered to the community and tried to explain in their own words what they learned and built. In this work, we present the most successful experimental designs and the educational standards we tried to develop with this activity.

  14. Observaciones del disco solar y de una protuberancia quiescente en radiación ultravioleta

    NASA Astrophysics Data System (ADS)

    Cirigliano, D.; Vial, J.-C.; Rovira, M.

    Observaciones del disco solar y de una protuberancia quiescente en el rango de longitudes de onda ultravioleta fueron obtenidas con el instrumento CDS (Coronal Diagnostic Spectrograph) y SUMER (Solar Ultraviolet Measurements of emitted radiation) a bordo de la sonda SOHO. El propósito es investigar las velocidades macroscópicas de varias especies metálicas que se observan tanto en el disco solar como en el plasma de las protuberancias. Para calcular las velocidades del disco solar aplicamos una técnica mixta para modelar la distribución de estructuras en UV en el Sol quieto. Las velocidades macroscópicas en las protuberancias se calcularon a partir de los corrimientos Doppler en cada línea espectral y luego se tomaron las del disco solar como referencia. Obtuvimos valores absolutos para las velocidades macroscópicas entre 5 y 40 km/seg. También detectamos comportamientos diferentes en las velocidades de las protuberancias en el centro con respecto a los bordes.

  15. El diseño final del espectrógrafo de banco (EBASIM) para CASLEO

    NASA Astrophysics Data System (ADS)

    Simmons, J.; Levato, H.

    Utilizando el código de óptica ACCOS V se ha finalizado el diseño del espectrógrafo de banco para CASLEO. En una comunicación anterior habíamos indicado que utilizaríamos un colimador de 150 mm de diámetro con un radio de curvatura de 1540 mm. Para el espejo cámara, que tiene un diámetro de 200 mm, el radio de curvatura es de 1200 mm, ambos radios con una tolerancia no mayor a los 3 mm. En la presente, se informa sobre los detalles finales del cálculo del espectrógrafo que incluye el cómputo para 5 longitudes de onda diferentes y alrededor de 100 rayos. En todos los casos el 75 % de energía está dentro de un diámetro de 13 micrones. El diseño ha sido probado entre 3500 Å hasta 9000 Å con resultados satisfactorios.

  16. A Precambrian cratonic block in the west-central Chihuahua - The Sierra del Nido cratonic block

    SciTech Connect

    Goodell, P.C. . Dept. of Geological)

    1993-02-01

    Precambrian rocks in west-central Chihuahua have been recognized by Denison (1969) and Mauger et al. (1983), on the basis of radiometric dating. The rocks are rhyolite clasts, and an allucthonous block, respectively, however their source direction and vergence can be measured. They point back to and are on the edge of a large, uniform, negative Bouguer gravity anomaly, having values greater than 200 milligals. The isotopic geochemical character of several Tertiary felsic fields within this anomalous are has been determined, and initial strontium isotopic ratios are all greater than 0.7055. Outside the anomalous area these ratios are lower, and Basin and Range extension tectonism is more evident. It is proposed that a Precambrian cratonic block, the Sierra del Nido, is present in the crust in west-central Chihuahua. It is reasonable to propose that it was decreted from North America during a Precambrian extensional (1.1. By ) event, from somewhere along the Arizona Transition Zone-Texas Linament region. The Sierra del Nido Block is separated form the ATZ-TL by a region of disrupted craton and extended crust, the Basin and Range Province. Implications of the pressure of the Sierra del Nido Block on other regional tectonic events will be discussed.

  17. D-branes at del Pezzo singularities: global embedding and moduli stabilisation

    NASA Astrophysics Data System (ADS)

    Cicoli, Michele; Krippendorf, Sven; Mayrhofer, Christoph; Quevedo, Fernando; Valandro, Roberto

    2012-09-01

    In the context of type IIB string theory we combine moduli stabilisation and model building on branes at del Pezzo singularities in a fully consistent global compactification. By means of toric geometry, we classify all the Calabi-Yau manifolds with 3 < h 1,1 < 6 which admit two identical del Pezzo singularities mapped into each other under the orientifold involution. This effective singularity hosts the visible sector containing the Standard Model while the Kähler moduli are stabilised via a combination of D-terms, perturbative and non-perturbative effects supported on hidden sectors. We present concrete models where the visible sector, containing the Standard Model, gauge and matter content, is built via fractional D3-branes at del Pezzo singularities and all the Kähler moduli are fixed providing an explicit realisation of both KKLT and LARGE volume scenarios, the latter with D-term uplifting to de Sitter minima. We perform the consistency checks for global embedding such as tadpole, K-theory charges and Freed-Witten anomaly cancellation. We briefly discuss phenomenological and cosmological implications of our models.

  18. Heat flow and thermal processes in the Jornada delMuerto, New Mexico

    NASA Technical Reports Server (NTRS)

    Reiter, M.

    1985-01-01

    Most heat flow data in rifts are uncertain largely because of hydrologic disturbances in regions of extensive fracturing. Estimates of heat flow in deep petroleum tests within a large basin of the Rio Grande rift, which has suffered little syn-rift fracturing, may begin to provide clearer insight into the relationships between high heat flow and crustal thinning processes. The Jornada del Muerto is a large basin located in the Rio Grande rift of south central New Mexico. The region of interest within the Jornada del Muerto is centered about 30 km east of the town of Truth or Consequences, and is approximately 60 km north-south by 30 km east-west. High heat flows are estimated for the region. Values increase from about 90 mWm(-2) in the northern part of the study area to about 125 mWm(-2) in the southern part. These high heat flows are rather enigmatic because in the immediate vicinities of the sites there is little evidence of Cenozoic volcanism or syn-rift extensional tectonics. It is suggested that the geothermal anomaly in the southern Jornada del Muerto (approx. 125 to approx. 95 mWm(-2) results from some type of mass movement-heat transfer mechanism operating in the crust just below the elastic layer. This conclusion is consistent with the geologic and geophysical data which describe a thin crust, apparently devoid of features indicative of extensional-tectonics in the upper part of the lastic crust.

  19. Mitochondrial DNA diversity of feral pigs from Karukinka Natural Park, Tierra del Fuego Island, Chile.

    PubMed

    Aravena, P; Skewes, O; Gouin, N

    2015-01-01

    Control or eradication of exotic species is one of the greatest challenges facing biodiversity and ecosystem conservation. Domestic pigs (Sus scrofa domestica) were released and became feral in the southern region of Chilean Tierra del Fuego Island in the 1900s. Currently, they inhabit part of Karukinka Natural Park, an area of global conservation concern. To gain insight into the control of this invasive species, we analyzed genetic variation in the mitochondrial DNA control region to determine the origin and population subdivision of feral pigs in Tierra del Fuego. Sequences from a sample of 42 feral pigs, 10 domestic pigs from local farms, and references from other countries and commercial breeds revealed 2 highly differentiated populations, 1 in the western and the other in the eastern area of the park, each harboring a different haplotype, suggesting no connectivity between populations. Comparison of these haplotypes with reference sequences from other countries and commercial breeds indicated that feral pigs from Chilean Tierra del Fuego are of European origin, very likely from 2 separate introduction events. The haplotype found in the western feral population was also identified in domestic pigs from a farm. This raises concerns regarding the possible connectivity between stocks from local farms and the wild population. Based on these results, we recommend the development of strategies for controlling the population of this invasive species in Karukinka Natural Park. PMID:25966196

  20. 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.

  1. [Seventy years of medicine in the Instituto Mexicano del Seguro Social].

    PubMed

    Fajardo-Ortiz, Guillermo

    2014-01-01

    The purpose of these lines is to remember and refer some of the historical landmarks in the evolution of the medical services of the Instituto Mexicano del Seguro Social (IMSS, according to its initials in Spanish) since it was founded, in 1943. We also want to bring to the reader's attention that the dimensions and impacts on health that IMSS has achieved, throughout its history, have strengthened the citizenship, as well as social sustainability. Also, those impacts have determined the creation and the reinforcement of human capital in México. Throughout this concise balance, all the controversy surrounding the foundation of the Institute is being recalled (the protest in the Mexico City Zócalo, or the attack to an hospital in San Ángel -a neighborhood located in the Southwest of Mexico City-), as well as the way the IMSS incorporated several words into the vocabulary of Mexicans. We also remember the previous antecedent of the Revista Médica del Instituto Mexicano del Seguro Social, as well as the Revista de Enfermería, and the emblematic Archives of Medical Research. The IMSS has 70 years of achievements, seven decades covered. PMID:24758865

  2. Moléculas orgánicas obtenidas en simulaciones experimentales del medio interestelar.

    NASA Astrophysics Data System (ADS)

    Muñoz-Caro, Guillermo Manuel

    Las nubes moleculares son regiones de formación de estrellas, con temperaturas cinéticas entre 10-50 K y densidades de 103-106 átomos cm-3. Su materia está formada por gas y polvo interestelar. Estas partículas de polvo están cubiertas por una fina capa de hielo, de unos 0.01 μm, que contiene H2O y a menudo CO, CO2, CH3OH y NH3. El hielo es presumiblemente irradiado por fotones ultravioleta y rayos cósmicos en las zonas poco profundas de las nubes moleculares y las regiones circunestelares. En un sistema de vacío, P ˜ 10-7 mbar, simulamos la deposición de hielo a partir de 10 K y la irradiación ultravioleta por medio de una lámpara de descarga de hidrógeno activada con microondas. La evolución del hielo se observa por medio de un espectrómetro infrarrojo. De este modo es posible determinar la composición del hielo observado en el medio interestelar y predecir la presencia de moléculas aún no detectadas en el espacio, que han sido producto del procesamiento del hielo en nuestros experimentos. También es posible calentar el sistema hasta temperatura ambiente para sublimar el hielo depositado. Cuando el hielo ha sido previamente irradiado, se observa un residuo compuesto por moléculas orgánicas complejas, algunas prebióticas, como varios ácidos carboxílicos, aminas, amidas, ésteres y en menor proporción moléculas heterocíclicas y aminoácidos. Algunas de estas moléculas podrían detectarse en estado gaseoso por medio de observaciones milimétricas y de radio. También podrían estar presentes en el polvo cometario, cuyo análisis químico está planeado por las misiones Stardust y Rosetta. Mientras tanto, nuestro grupo está llevando a cabo el análisis de partículas de polvo interplanetario (IDPs), algunas de las cuales pueden ser de origen cometario. Al igual que ocurre con los productos obtenidos por irradiación del hielo en nuestros experimentos, algunas IDPs son ricas en material orgánico que contiene oxígeno.

  3. Abnormal spatial diffusion of Ca2+ in F508del-CFTR airway epithelial cells

    PubMed Central

    Antigny, Fabrice; Norez, Caroline; Cantereau, Anne; Becq, Frédéric; Vandebrouck, Clarisse

    2008-01-01

    Background In airway epithelial cells, calcium mobilization can be elicited by selective autocrine and/or paracrine activation of apical or basolateral membrane heterotrimeric G protein-coupled receptors linked to phospholipase C (PLC) stimulation, which generates inositol 1,4,5-trisphosphate (IP3) and 1,2-diacylglycerol (DAG) and induces Ca2+ release from endoplasmic reticulum (ER) stores. Methods In the present study, we monitored the cytosolic Ca2+ transients using the UV light photolysis technique to uncage caged Ca2+ or caged IP3 into the cytosol of loaded airway epithelial cells of cystic fibrosis (CF) and non-CF origin. We compared in these cells the types of Ca2+ receptors present in the ER, and measured their Ca2+ dependent activity before and after correction of F508del-CFTR abnormal trafficking either by low temperature or by the pharmacological corrector miglustat (N-butyldeoxynojirimycin). Results We showed reduction of the inositol 1,4,5-trisphosphate receptors (IP3R) dependent-Ca2+ response following both correcting treatments compared to uncorrected cells in such a way that Ca2+ responses (CF+treatment vs wild-type cells) were normalized. This normalization of the Ca2+ rate does not affect the activity of Ca2+-dependent chloride channel in miglustat-treated CF cells. Using two inhibitors of IP3R1, we observed a decrease of the implication of IP3R1 in the Ca2+ response in CF corrected cells. We observed a similar Ca2+ mobilization between CF-KM4 cells and CFTR-cDNA transfected CF cells (CF-KM4-reverted). When we restored the F508del-CFTR trafficking in CFTR-reverted cells, the specific IP3R activity was also reduced to a similar level as in non CF cells. At the structural level, the ER morphology of CF cells was highly condensed around the nucleus while in non CF cells or corrected CF cells the ER was extended at the totality of cell. Conclusion These results suggest reversal of the IP3R dysfunction in F508del-CFTR epithelial cells by correction of

  4. Systematically frameshifting by deletion of every 4th or 4th and 5th nucleotides during mitochondrial transcription: RNA self-hybridization regulates delRNA expression.

    PubMed

    Seligmann, Hervé

    2016-01-01

    In mitochondria, secondary structures punctuate post-transcriptional RNA processing. Recently described transcripts match the human mitogenome after systematic deletions of every 4th, respectively every 4th and 5th nucleotides, called delRNAs. Here I explore predicted stem-loop hairpin formation by delRNAs, and their associations with delRNA transcription and detected peptides matching their translation. Despite missing 25, respectively 40% of the nucleotides in the original sequence, del-transformed sequences form significantly more secondary structures than corresponding randomly shuffled sequences, indicating biological function, independently of, and in combination with, previously detected delRNA and thereof translated peptides. Self-hybridization decreases delRNA abundances, indicating downregulation. Systematic deletions of the human mitogenome reveal new, unsuspected coding and structural informations. PMID:27018206

  5. Restoration of CFTR function in patients with cystic fibrosis carrying the F508del-CFTR mutation

    PubMed Central

    Stefano, Daniela De; Villella, Valeria R; Esposito, Speranza; Tosco, Antonella; Sepe, Angela; Gregorio, Fabiola De; Salvadori, Laura; Grassia, Rosa; Leone, Carlo A; Rosa, Giuseppe De; Maiuri, Maria C; Pettoello-Mantovani, Massimo; Guido, Stefano; Bossi, Anna; Zolin, Anna; Venerando, Andrea; Pinna, Lorenzo A; Mehta, Anil; Bona, Gianni; Kroemer, Guido; Maiuri, Luigi; Raia, Valeria

    2014-01-01

    Restoration of BECN1/Beclin 1-dependent autophagy and depletion of SQSTM1/p62 by genetic manipulation or autophagy-stimulatory proteostasis regulators, such as cystamine, have positive effects on mouse models of human cystic fibrosis (CF). These measures rescue the functional expression of the most frequent pathogenic CFTR mutant, F508del, at the respiratory epithelial surface and reduce lung inflammation in CftrF508del homozygous mice. Cysteamine, the reduced form of cystamine, is an FDA-approved drug. Here, we report that oral treatment with cysteamine greatly reduces the mortality rate and improves the phenotype of newborn mice bearing the F508del-CFTR mutation. Cysteamine was also able to increase the plasma membrane expression of the F508del-CFTR protein in nasal epithelial cells from F508del homozygous CF patients, and these effects persisted for 24 h after cysteamine withdrawal. Importantly, this cysteamine effect after washout was further sustained by the sequential administration of epigallocatechin gallate (EGCG), a green tea flavonoid, both in vivo, in mice, and in vitro, in primary epithelial cells from CF patients. In a pilot clinical trial involving 10 F508del-CFTR homozygous CF patients, the combination of cysteamine and EGCG restored BECN1, reduced SQSTM1 levels and improved CFTR function from nasal epithelial cells in vivo, correlating with a decrease of chloride concentrations in sweat, as well as with a reduction of the abundance of TNF/TNF-alpha (tumor necrosis factor) and CXCL8 (chemokine [C-X-C motif] ligand 8) transcripts in nasal brushing and TNF and CXCL8 protein levels in the sputum. Altogether, these results suggest that optimal schedules of cysteamine plus EGCG might be used for the treatment of CF caused by the F508del-CFTR mutation. PMID:25350163

  6. The Human 343delT HSPB5 Chaperone Associated with Early-onset Skeletal Myopathy Causes Defects in Protein Solubility.

    PubMed

    Mitzelfelt, Katie A; Limphong, Pattraranee; Choi, Melinda J; Kondrat, Frances D L; Lai, Shuping; Kolander, Kurt D; Kwok, Wai-Meng; Dai, Qiang; Grzybowski, Michael N; Zhang, Huali; Taylor, Graydon M; Lui, Qiang; Thao, Mai T; Hudson, Judith A; Barresi, Rita; Bushby, Kate; Jungbluth, Heinz; Wraige, Elizabeth; Geurts, Aron M; Benesch, Justin L P; Riedel, Michael; Christians, Elisabeth S; Minella, Alex C; Benjamin, Ivor J

    2016-07-15

    Mutations of HSPB5 (also known as CRYAB or αB-crystallin), a bona fide heat shock protein and molecular chaperone encoded by the HSPB5 (crystallin, alpha B) gene, are linked to multisystem disorders featuring variable combinations of cataracts, cardiomyopathy, and skeletal myopathy. This study aimed to investigate the pathological mechanisms involved in an early-onset myofibrillar myopathy manifesting in a child harboring a homozygous recessive mutation in HSPB5, 343delT. To study HSPB5 343delT protein dynamics, we utilize model cell culture systems including induced pluripotent stem cells derived from the 343delT patient (343delT/343delT) along with isogenic, heterozygous, gene-corrected control cells (WT KI/343delT) and BHK21 cells, a cell line lacking endogenous HSPB5 expression. 343delT/343delT and WT KI/343delT-induced pluripotent stem cell-derived skeletal myotubes and cardiomyocytes did not express detectable levels of 343delT protein, contributable to the extreme insolubility of the mutant protein. Overexpression of HSPB5 343delT resulted in insoluble mutant protein aggregates and induction of a cellular stress response. Co-expression of 343delT with WT prevented visible aggregation of 343delT and improved its solubility. Additionally, in vitro refolding of 343delT in the presence of WT rescued its solubility. We demonstrate an interaction between WT and 343delT both in vitro and within cells. These data support a loss-of-function model for the myopathy observed in the patient because the insoluble mutant would be unavailable to perform normal functions of HSPB5, although additional gain-of-function effects of the mutant protein cannot be excluded. Additionally, our data highlight the solubilization of 343delT by WT, concordant with the recessive inheritance of the disease and absence of symptoms in carrier individuals. PMID:27226619

  7. 500 days of Stromgren b, y and narrow-band [OIII], H α photometric evolution of gamma-ray Nova Del 2013 (=V339 Del)

    NASA Astrophysics Data System (ADS)

    Munari, Ulisse; Maitan, Alessandro; Moretti, Stefano; Tomaselli, Salvatore

    2015-10-01

    We present and discuss highly accurate photometry obtained through medium Stromgren y, b bands and narrow [OIII], Hα bands covering 500 days of the evolution of Nova Del 2013 since its maximum brightness. This is by far the most complete study of any nova observed in such photometric systems. The nova behavior in these photometric bands is very different from that observed with the more conventional broad bands like UBVRC IC or u‧g‧r‧i‧z‧ , providing unique information about extent and ionization of the ejecta, the onset of critical phases like the transition between optically thick and thin conditions, and re-ionization by the central super-soft X-ray source. The actual transmission profiles of the y, b , [OIII] and Hα photometric filters have been accurately measured at different epochs and different illumination angles, to evaluate in detail their performance under exact operating conditions. The extreme smoothness of both the Hα and [OIII] lightcurves argues for absence of large and abrupt discontinuities in the ejecta of Nova Del 2013. Should they exist, glitches in the lightcurves would have appeared when the ionization and/or recombination fronts overtook them. During the period of recorded very large variability (up to 100× over a single day) in the super-soft X-ray emission (from day +69 to +86 past V maximum), no glitch in excess of 1% was observed in the optical photometry, either in the continuum (Stromgren y) or in the lines ([OIII] and Hα filters), or in a combination of the two (Stromgren b, Johnson B and V). Considering that the recombination time scale in the ejecta was one week at that time, this excludes global changes of the white dwarf as the source of the X-ray variability and supports instead clumpy ejecta passing through the line of sight to us as its origin.

  8. Thermal unfolding studies show the disease causing F508del mutation in CFTR thermodynamically destabilizes nucleotide-binding domain 1.

    PubMed

    Protasevich, Irina; Yang, Zhengrong; Wang, Chi; Atwell, Shane; Zhao, Xun; Emtage, Spencer; Wetmore, Diana; Hunt, John F; Brouillette, Christie G

    2010-10-01

    Misfolding and degradation of CFTR is the cause of disease in patients with the most prevalent CFTR mutation, an in-frame deletion of phenylalanine (F508del), located in the first nucleotide-binding domain of human CFTR (hNBD1). Studies of (F508del)CFTR cellular folding suggest that both intra- and inter-domain folding is impaired. (F508del)CFTR is a temperature-sensitive mutant, that is, lowering growth temperature, improves both export, and plasma membrane residence times. Yet, paradoxically, F508del does not alter the fold of isolated hNBD1 nor did it seem to perturb its unfolding transition in previous isothermal chemical denaturation studies. We therefore studied the in vitro thermal unfolding of matched hNBD1 constructs ±F508del to shed light on the defective folding mechanism and the basis for the thermal instability of (F508del)CFTR. Using primarily differential scanning calorimetry (DSC) and circular dichroism, we show for all hNBD1 pairs studied, that F508del lowers the unfolding transition temperature (T(m)) by 6-7°C and that unfolding occurs via a kinetically-controlled, irreversible transition in isolated monomers. A thermal unfolding mechanism is derived from nonlinear least squares fitting of comprehensive DSC data sets. All data are consistent with a simple three-state thermal unfolding mechanism for hNBD1 ± F508del: N(±MgATP) <==> I(T)(±MgATP) → A(T) → (A(T))(n). The equilibrium unfolding to intermediate, I(T), is followed by the rate-determining, irreversible formation of a partially folded, aggregation-prone, monomeric state, A(T), for which aggregation to (A(T))(n) and further unfolding occur with no detectable heat change. Fitted parameters indicate that F508del thermodynamically destabilizes the native state, N, and accelerates the formation of A(T). PMID:20687133

  9. Genetic Inhibition Of The Ubiquitin Ligase Rnf5 Attenuates Phenotypes Associated To F508del Cystic Fibrosis Mutation

    PubMed Central

    Tomati, Valeria; Sondo, Elvira; Armirotti, Andrea; Caci, Emanuela; Pesce, Emanuela; Marini, Monica; Gianotti, Ambra; Ju Jeon, Young; Cilli, Michele; Pistorio, Angela; Mastracci, Luca; Ravazzolo, Roberto; Scholte, Bob; Ronai, Ze’ev; Galietta, Luis J. V.; Pedemonte, Nicoletta

    2015-01-01

    Cystic fibrosis (CF) is caused by mutations in the CFTR chloride channel. Deletion of phenylalanine 508 (F508del), the most frequent CF mutation, impairs CFTR trafficking and gating. F508del-CFTR mistrafficking may be corrected by acting directly on mutant CFTR itself or by modulating expression/activity of CFTR-interacting proteins, that may thus represent potential drug targets. To evaluate possible candidates for F508del-CFTR rescue, we screened a siRNA library targeting known CFTR interactors. Our analysis identified RNF5 as a protein whose inhibition promoted significant F508del-CFTR rescue and displayed an additive effect with the investigational drug VX-809. Significantly, RNF5 loss in F508del-CFTR transgenic animals ameliorated intestinal malabsorption and concomitantly led to an increase in CFTR activity in intestinal epithelial cells. In addition, we found that RNF5 is differentially expressed in human bronchial epithelia from CF vs. control patients. Our results identify RNF5 as a target for therapeutic modalities to antagonize mutant CFTR proteins. PMID:26183966

  10. Developing market class specific InDel markers from next generation sequence data in Phaseolus vulgaris L.

    PubMed Central

    Moghaddam, Samira Mafi; Song, Qijian; Mamidi, Sujan; Schmutz, Jeremy; Lee, Rian; Cregan, Perry; Osorno, Juan M.; McClean, Phillip E.

    2013-01-01

    Next generation sequence data provides valuable information and tools for genetic and genomic research and offers new insights useful for marker development. This data is useful for the design of accurate and user-friendly molecular tools. Common bean (Phaseolus vulgaris L.) is a diverse crop in which separate domestication events happened in each gene pool followed by race and market class diversification that has resulted in different morphological characteristics in each commercial market class. This has led to essentially independent breeding programs within each market class which in turn has resulted in limited within market class sequence variation. Sequence data from selected genotypes of five bean market classes (pinto, black, navy, and light and dark red kidney) were used to develop InDel-based markers specific to each market class. Design of the InDel markers was conducted through a combination of assembly, alignment and primer design software using 1.6× to 5.1× coverage of Illumina GAII sequence data for each of the selected genotypes. The procedure we developed for primer design is fast, accurate, less error prone, and higher throughput than when they are designed manually. All InDel markers are easy to run and score with no need for PCR optimization. A total of 2687 InDel markers distributed across the genome were developed. To highlight their usefulness, they were employed to construct a phylogenetic tree and a genetic map, showing that InDel markers are reliable, simple, and accurate. PMID:24860578

  11. miR-16 rescues F508del-CFTR function in native cystic fibrosis epithelial cells.

    PubMed

    Kumar, P; Bhattacharyya, S; Peters, K W; Glover, M L; Sen, A; Cox, R T; Kundu, S; Caohuy, H; Frizzell, R A; Pollard, H B; Biswas, R

    2015-11-01

    Cystic fibrosis (CF) is due to mutations in the CFTR gene, which prevents correct folding, trafficking and function of the mutant cystic fibrosis transmembrane conductance regulator (CFTR) protein. The dysfunctional effect of CFTR mutations, principally the F508del-CFTR mutant, is further manifested by hypersecretion of the pro-inflammatory chemokine interleukin-8 into the airway lumen, which further contributes to morbidity and mortality. We have hypothesized that microRNA (miR)-based therapeutics could rescue the dysfunctional consequences of mutant CFTR. Here we report that a miR-16 mimic can effectively rescue F508del-CFTR protein function in airway cell lines and primary cultures, of differentiated human bronchial epithelia from F508del homozygotes, which express mutant CFTR endogenously. We also identify two other miRs, miR-1 and miR-302a, which are also active. Although miR-16 is expressed at basal comparable levels in CF and control cells, miR-1 and miR-302a are undetectable. When miR mimics are expressed in CF lung or pancreatic cells, the expression of the F508del-CFTR protein is significantly increased. Importantly, miR-16 promotes functional rescue of the cyclic AMP-activated apical F508del-CFTR chloride channel in primary lung epithelial cells from CF patients. We interpret these findings to suggest that these miRs may constitute novel targets for CF therapy. PMID:26133785

  12. Developing market class specific InDel markers from next generation sequence data in Phaseolus vulgaris L.

    PubMed

    Moghaddam, Samira Mafi; Song, Qijian; Mamidi, Sujan; Schmutz, Jeremy; Lee, Rian; Cregan, Perry; Osorno, Juan M; McClean, Phillip E

    2014-01-01

    Next generation sequence data provides valuable information and tools for genetic and genomic research and offers new insights useful for marker development. This data is useful for the design of accurate and user-friendly molecular tools. Common bean (Phaseolus vulgaris L.) is a diverse crop in which separate domestication events happened in each gene pool followed by race and market class diversification that has resulted in different morphological characteristics in each commercial market class. This has led to essentially independent breeding programs within each market class which in turn has resulted in limited within market class sequence variation. Sequence data from selected genotypes of five bean market classes (pinto, black, navy, and light and dark red kidney) were used to develop InDel-based markers specific to each market class. Design of the InDel markers was conducted through a combination of assembly, alignment and primer design software using 1.6× to 5.1× coverage of Illumina GAII sequence data for each of the selected genotypes. The procedure we developed for primer design is fast, accurate, less error prone, and higher throughput than when they are designed manually. All InDel markers are easy to run and score with no need for PCR optimization. A total of 2687 InDel markers distributed across the genome were developed. To highlight their usefulness, they were employed to construct a phylogenetic tree and a genetic map, showing that InDel markers are reliable, simple, and accurate. PMID:24860578

  13. The Torres del Paine intrusion as a model for a shallow magma chamber

    NASA Astrophysics Data System (ADS)

    Baumgartner, Lukas; Bodner, Robert; Leuthold, Julien; Muntener, Othmar; Putlitz, Benita; Vennemann, Torsten

    2014-05-01

    The shallow magmatic Torres del Paine Intrusive Complex (TPIC) belongs to a series of sub-volcanic and plutonic igneous bodies in Southern Chile and Argentina. This trench-parallel belt is located in a transitional position between the Patagonia Batholith in the West, and the alkaline Cenozoic plateau lavas in the East. While volumetrically small amounts of magmatism started around 28 my ago in the Torres del Paine area, and a second period occurred between 17-16 Ma, it peaked with the TPIC 12.59-12.43 Ma ago. The spectacular cliffs of the Torres del Paine National park provide a unique opportunity to study the evolution of a very shallow magma chamber and the interaction with its host rocks. Intrusion depth can be estimated based on contact metamorphic assemblages and granite solidus thermobarometry to 750±250 bars, corresponding to an intrusion depth of ca. 3km, ca. 500m above the base of the intrusion. Hornblende thermobarometry in mafic rocks agrees well with these estimates (Leuthold et al., 2014). The TPIC is composed of a granitic laccolith emplaced over 90ka (Michel et al., 2008) in 3 major, several 100m thick sheets, forming an overall thickness of nearly 2 km. Contacts are sharp between sheets, with the oldest sheet on the top and the youngest on the bottom (Michel et al., 2008). The granitic laccolith is under-plated by a ca. 400m thick mafic laccolith, built up over ca. 50ka (Leuthold et al. 2012), constructed from the bottom up. Granitic and mafic sheets are themselves composed of multiple metric to decametric pulses, mostly with ductile contacts between them, resulting in outcrop patterns resembling braided stream sediments. The contact of the TPIC with the Cretaceous flysch sediments document intrusion mechanism. Pre-existing sub-horizontal fold axes are rotated in the roof of the TPIC, clearly demonstrating ballooning of the roof; no ballooning was observed in the footwall of the intrusion. Extension during ballooning of the roof is indicated by

  14. Towards a systematic construction of realistic D-brane models on a del Pezzo singularity

    NASA Astrophysics Data System (ADS)

    Dolan, Matthew J.; Krippendorf, Sven; Quevedo, Fernando

    2011-10-01

    A systematic approach is followed in order to identify realistic D-brane models at toric del Pezzo singularities. Requiring quark and lepton spectrum and Yukawas from D3 branes and massless hypercharge, we are led to Pati-Salam extensions of the Standard Model. Hierarchies of masses, flavour mixings and control of couplings select higher order del Pezzo singularities, minimising the Higgs sector prefers toric del Pezzos with dP 3 providing the most successful compromise. Then a supersymmetric local string model is presented with the following properties at low energies: (i) the MSSM spectrum plus a local B - L gauge field or additional Higgs fields depending on the breaking pattern, (ii) a realistic hierarchy of quark and lepton masses and (iii) realistic flavour mixing between quark and lepton families with computable CKM and PMNS matrices, and CP violation consistent with observations. In this construction, kinetic terms are diagonal and under calculational control suppressing standard FCNC contributions. Proton decay operators of dimension 4, 5, 6 are suppressed, and gauge couplings can unify depending on the breaking scales from string scales at energies in the range 1012-1016 GeV, consistent with TeV soft-masses from moduli mediated supersymmetry breaking. The GUT scale model corresponds to D3 branes at dP 3 with two copies of the Pati-Salam gauge symmetry SU(4) × SU(2) R × SU(2) L . D-brane instantons generate a non-vanishing μ-term. Right handed sneutrinos can break the B - L symmetry and induce a see-saw mechanism of neutrino masses and R-parity violating operators with observable low-energy implications.

  15. Multimodal Assessment of Protein Functional Deficiency Supports Pathogenicity of BRCA1 p.V1688del

    PubMed Central

    De Nicolo, Arcangela; Parisini, Emilio; Zhong, Quan; Palma, Maurizia Dalla; Stoeckert, Kathryn A.; Domchek, Susan M.; Nathanson, Katherine L.; Caligo, Maria A.; Vidal, Marc; Cusick, Michael E.; Garber, Judy E.

    2009-01-01

    Unequivocal discrimination between neutral variants and deleterious mutations is crucial for appropriate counseling of individuals with a BRCA1 or BRCA2 sequence change. An increasing number of variants of uncertain significance (VUSs) are being identified, whose unclassified biological effect poses clinical concerns. A multifactorial likelihood-based approach recently suggested disease causality for BRCA1 p.V1688del, a VUS recurrent in Italian breast/ovarian cancer families. Whether and how this single amino acid deletion in the BRCA1 BRCT domain affects the function of the mutant protein (ΔValBRCA1) has not been elucidated. We undertook comprehensive functional characterization of ΔValBRCA1, comprising comparative structural modeling, analysis of protein stability and associations, and analysis of DNA repair function. Our model predicted BRCT domain destabilization and folding disruption caused by BRCA1 p.V1688del. Consistently, the recombinant ΔValBRCA1 was less stable than wtBRCA1 and, unlike the latter, failed to associate with BRIP1, CtIP, and Rap80, and to re-localize to sites of DNA damage. Yeast two-hybrid analysis revealed a compromised interaction with FHL2 and with KPNA2, which is likely responsible for improper subcellular localization of ΔValBRCA1. In addition, we found four new breast/ovarian cancer families of Italian ancestry who carried this sequence alteration. These results provide the first evidence of the effect of BRCA1 p.V1688del on protein stability and function, supporting the view that it is a deleterious mutation. Multimodal analyses like ours could advance understanding of tumor suppression by BRCA1, and ultimately contribute to developing efficient strategies for screening and characterization of VUSs. PMID:19706752

  16. Petroleum geology of the deltaic sequence, Rio Del Rey basin, offshore Cameroon

    SciTech Connect

    Coughlin, R.M.; Bement, W.O.; Maloney, W.V. )

    1993-09-01

    The Rio Del Rey Basin of offshore Cameroon comprises the easternmost portion of the Niger delta complex. In the delta flank setting, the overall package is thinner and stratigraphic correlation simpler than in the depocenter to the west so the distribution of reservoirs and seals is well defined. Productive reservoirs are shallow, typically less than 2000 m, and mostly hydropressured to slightly overpressured. Reservoir properties generally are excellent and seismic bright-spot technology has played a major role in exploration and development efforts. Rio Del Rey is characterized by three main structural styles from north to south: (1) detachment-based growth faults, (2) highly faulted, mobile shale cored domes and ridges, and (3) toe thrusts and folds. Virtually all individual traps are fault dependent and lack of sufficient internal seals in sand-rich wave-dominated deltaic sequences can limit the objective window. Most fields are downthrown fault traps in which hanging-wall reservoirs are effectively sealed against older prodelta and marine shales. All large oil fields are located in the dome and ridge province and are potential analogs for similar structures now being explored on the upper slope off Nigeria. The best quality source rocks identified thus far are Paleocene to Eocene marine shales. Oil vs. gas distribution in the basin is a function of variations in the kerogen type, organic richness, and maturity of these source rocks. A significant quantity of the gas found to date in Rio Del Rey is biogenic in origin. The Cameroon charge model may aid in better understanding hydrocarbon distribution on offshore Nigeria, where the Miocene deltaic section is much thicker and potential Paleocene-Eocene source rocks likely are unpenetrated. The shallow deltaic play in Cameroon is relatively mature. Future exploration likely will focus on identifying deeper, nonbright-spot-supported opportunities including potential stratigraphic traps.

  17. Match fitness: development, evolution, and behavior: comment on Frankenhuis and Del Giudice (2012).

    PubMed

    Gluckman, Peter D; Beedle, Alan S

    2012-05-01

    The application of evolutionary thinking to human physical and psychological medicine suggests several pathways through which evolutionary processes affect risk of disease. Among these is the concept of mismatch between an individual and its environment, either because the environment has changed for the whole species (evolutionary novelty) or because the environment has changed for an individual during its lifetime (developmental mismatch). Here we set a discussion of maladaptation and mismatch as a cause of psychopathology (Frankenhuis & Del Giudice, 2012) in the broader framework of developmental plasticity and life history trade-offs. PMID:22545849

  18. Early neogene history of the central American arc from Bocas del Toro, western Panama

    USGS Publications Warehouse

    Coates, A.G.; Aubry, M.-P.; Berggren, W.A.; Collins, Luke S.; Kunk, M.

    2003-01-01

    A newly discovered sequence of lower to middle Miocene rocks from the eastern Bocas del Toro archipelago, western Panama, reveals the timing and environment of the earliest stages in the rise of the Isthmus of Panama in this region. Two new formations, the Punta Alegre Formation (lower Miocene, Aquitanian to Burdigalian) and the Valiente Formation (middle Miocene, Langhian to Serravallian), are here named and formally described. The Punta Alegre Formation contains a diagnostic microfauna of benthic and planktic foraminifera and calcareous nannofossils that indicate deposition in a 2000-m-deep pre-isthmian neotropical ocean from as old as 21.5-18.3 Ma. Its lithology varies from silty mudstone to muddy foraminiferal ooze with rare thin microturbidite layers near the top. The Valiente Formation, which ranges in age from 16.4 to ca. 12.0 Ma, lies with slight angular unconformity on the Punta Alegre Formation and consists of five lithofacies: (1) columnar basalt and flow breccia, (2) pyroclastic deposits, (3) coarse-grained volcaniclastic deposits, (4) coral-reef limestone with diverse large coral colonies, and (5) marine debris-flow deposits and microturbidities. These lithofacies are interpreted to indicate that after ca. 16 Ma a volcanic arc developed in the region of Bocas del Toro and that by ca. 12 Ma an extensively emergent archipelago of volcanic islands had formed. 39Ar/40Ar dating of basalt flows associated with the fossiliferous sedimentary rocks in the upper part of the Valiente Formation strongly confirms the ages derived from planktic foraminifera and nannofossils. Paleobathymetric analysis of the two new formations in the Valiente Peninsula and Popa Island, in the Bocas del Toro archipelago, shows a general shallowing from lower- through upper-bathyal to upper-neritic and emergent laharic and fluviatile deposits from ca. 19 to 12 Ma. The overlying nonconformable Bocas del Toro Group contains a lower transgressive sequence ranging from basal nearshore

  19. Identifying bipolar knapping in the Mesolithic site of Font del Ros (northeast Iberia).

    PubMed

    Roda Gilabert, Xavier; Mora, Rafael; Martínez-Moreno, Jorge

    2015-11-19

    Despite recent advances in the identification of bipolar knapping, its role in many sites is not well known. We propose to assess the significance of this technique in the context of changes that occur in the Mesolithic. A lithic assemblage was recovered from unit SG at Font del Ros (Catalunya, Spain) in which pitted stones, cores and products arising from bipolar reduction (flakes, fragments and splintered pieces) were identified. This study indicates that the bipolar technique is fundamental in the settlement. These results are key to defining the organization of Holocene hunter-gatherer subsistence in northeast Iberia. PMID:26483532

  20. Descripción del coronógrafo a ser instalado en Argentina (MICA)

    NASA Astrophysics Data System (ADS)

    Stenborg, G.; Francile, C.; Schwenn, R.; Epple, A.; Rovira, M.

    El ``Coronógrafo de espejo para Argentina'' es un telescopio solar terrestre a ser colocado en el Observatorio Astronómico Félix Aguilar (El Leoncito), antes de finalizar 1996, como parte de un programa de ciencia bilateral entre Alemania y Argentina. Eclipses fotográficos de alta resolución han revelado que la corona solar es altamente estructurada y variable. De hecho, está contínuamente deformada y moldeada por los movimientos convectivos de los extremos de los arcos magnéticos en la fotosfera, estando, en muchas oportunidades, afectada por explosivas liberaciones de energía. MICA, en conjunción con otros telescopios solares espaciales y terrestres, tratará de contribuir al entendimiento de cuestiones fundamentales de la física solar. Entre ellas: cómo la corona está siendo calentada, dónde y cómo el viento solar es acelerado, qué causa los transitorios coronales, etc. Para ello investigará la distribución de los parámetros del plasma y su evolución con el tiempo, la estructura espacial de la corona en fina y gran escala, procesos que ocurren en los transitorios coronales y factores que los disparan, etc. Para responder a estas cuestiones MICA observará la atmósfera solar por sobre el limbo entre 1.1 y 2 radios solares aproximadamente, usando un nuevo tipo de sistema coronográfico que permite suprimir el brillo del disco solar suficientemente bien, tomando las imágenes con una cámara CCD de 1024x1024 pixels, codificada en 12 bits, pudiendo el mismo ser operado en forma remota. En la presente exposición describiremos las características del instrumento, cómo será controlado y qué esperamos observar basados en las imágenes obtenidas por los telescopios de similares características LASCO C1 a bordo del SOHO y PICO (ubicado en el Observatorio de Pic du Midi, Francia).

  1. Uranium series dating of human skeletal remains from the Del Mar and Sunnyvale sites, California

    USGS Publications Warehouse

    Bischoff, J.L.; Rosenbauer, R.J.

    1981-01-01

    Uranium series analyses of human bone samples from the Del Mar and Sunnyvale sites indicate ages of 11,000 and 8,300 years, respectively. The dates are supported by internal concordancy between thorium-230 and protactinium-231 decay systems. These ages are significantly younger than the estimates of 48,000 and 70,000 years based on amino acid racemization, and indicate that the individuals could derive from the population waves that came across the Bering Strait during the last sea-level low. Copyright ?? 1981 AAAS.

  2. Matuyama-age lithic tools from the Sima del Elefante site, Atapuerca (northern Spain).

    PubMed

    Parés, Josep M; Pérez-González, Alfredo; Rosas, Antonio; Benito, A; Bermúdez de Castro, J M; Carbonell, E; Huguet, R

    2006-02-01

    Paleomagnetic results obtained from the sedimentary fill at the Sima del Elefante site in Atapuerca, Spain, reveal a geomagnetic reversal, interpreted as the Matuyama-Brunhes boundary (0.78 Ma). The uppermost lithostratigraphic units (E17 through E19), which contain Mode II and III archaeological assemblages, display normal polarity magnetization, whereas the six lowermost units (E9 through E16) yield negative latitudinal virtual geomagnetic pole positions. Units E9 through E13, all of which display reverse magnetic polarity, contain Mode I (Oldowan) lithic tools, testifying to the presence of humans in the early Pleistocene (0.78-1.77 Ma). PMID:16249015

  3. Eruption of the nevado del ruiz volcano, Colombia, on 13 november 1985: tephra fall and lahars.

    PubMed

    Naranjo, J L; Sigurdsson, H; Carey, S N; Fritz, W

    1986-08-29

    A small Plinian eruption of the Nevado del Ruiz volcano in Colombia ejected 3.5 x 10(10) kilograms of mixed dacite and andesite tephra on 13 November 1985, with a maximum column height of 31 kilometers above sea level. Small pyroclastic flows and surges, generated during the initial stage of the eruption, caused surface melting of approximately 10% of the volcano's ice cap, leading to meltwater floods. The erosive floods incorporated soils and loose sediments from the volcano's flanks and developed into lahars, which claimed at least 25,000 lives. PMID:17732038

  4. Holocene paleoclimate characterization in Lago Fagnano (Tierra del Fuego) using sedimentary, physical and geochemical proxies

    NASA Astrophysics Data System (ADS)

    Vizcaino Marti, A.; Dunbar, R. B.; Wahl, D.; Moy, C. M.; Mucciarone, D. A.; Anderson, L.; Guilderson, T. P.

    2010-12-01

    Tierra del Fuego is the world's southernmost landmass outside of Antarctica. Two features of ocean circulation control the climate of Tierra del Fuego: the Southern Ocean circumpolar flow and the South Pacific Gyre. Together with Patagonia, Tierra del Fuego is the only terrestrial region directly influenced by the southern hemisphere westerly winds. This region is also a tectonically active area affected by volcanic and seismic activity related to South American and Scotia-Antarctic plate boundaries. Accommodated along the Magallanes-Fagnano fault system, as part of the plate boundary, the Lago Fagnano is the largest lake in Tierra del Fuego. This E-W trending lake is 100 km long and 5-15 km wide. Our investigations were carried out on the upper 4 meters of an 8.4 m long piston core obtained at 69 m water depth in Bahía Grande (LF06-PC8); a southwestern lake sub-basin separated from the main lake by a shallow sill. Our studies are based on the integration of sediment description, physical properties, pollen, and geochemical analyses including C and N isotopes (1cm interval) and XRF scan (1mm interval). The age model for the core is based on radiocarbon ages and tephrochronology. Additionally, a 800 km long grid of high resolution seismic profiles support the sedimentary analyses and allow the correlation with other cores from within the lake basin. LF06-PC8 yields continuous and high accumulation-rate sedimentary sections for Lago Fagnano. The presented sediment record corresponds to a laminated hemipelagite with presence of a single but complex mass transport deposit interval. An accurate sedimentological interpretation of the core together with the radiocarbon ages and tephra dates allow to identify and characterize the main sedimentary processes occurring in the lake over the last 8 kyr. In addition, proxy data (C and N isotopes and XRF scan data) from the laminated hemipelagic interval provide a reliable record of past variability in the westerly wind field as

  5. Uranium series dating of human skeletal remains from the Del Mar and Sunnyvale sites, California

    SciTech Connect

    Bischoff, J.L.; Rosenbauer, R.J.

    1981-08-28

    Uranium series analyses of human bone samples from the Del Mar and Sunnyvale sites indicate ages of 11,000 and 8300 years, respectively. The dates are supported by internal concordancy between thorium-230 and protactinium-231 decay systems. These ages are significantly younger than the estimates of 48,000 and 70,000 years based on amino acid racemization, and indicate that the individuals could derive from the population waves that came across the Bering Strait during the last sea-level low.

  6. Uranium series dating of human skeletal remains from the del mar and sunnyvale sites, california.

    PubMed

    Bischoff, J L; Rosenbauer, R J

    1981-08-28

    Uranium series analyses of human bone samples from the Del Mar and Sunnyvale sites indicate ages of 11,000 and 8,300 years, respectively. The dates are supported by internal concordancy between thorium-230 and protactinium-231 decay systems. These ages are significantly younger than the estimates of 48,000 and 70,000 years based on amino acid racemization, and indicate that the individuals could derive from the population waves that came across the Bering Strait during the last sea-level low. PMID:17789030

  7. La meridiana di Egnazio Danti nella Torre dei Venti in Vaticano: un'icona della riforma Gregoriana del calendario

    NASA Astrophysics Data System (ADS)

    Sigismondi, Costantino

    2014-05-01

    La Torre dei Venti domina l’angolo Sud Ovest del cortile della Pigna (nell'area dei Musei Vaticani), ed è inclusa negli ambienti dell'Archivio Segreto Vaticano. Non è aperta al pubblico, ma è universalmente nota per la fama che da oltre quattrocento anni la circonda, legata alle vicende della riforma Gregoriana del calendario. La meridiana tracciata da padre Egnazio Danti (1536-1586) nella torre dei Venti, fu visitata anche da Gregorio XIII, probabilmente il 21 marzo 1581 come suppone il padre Stein, per convincersi dell'anticipo ormai arrivato a dieci giorni dell'equinozio di primavera sulla data che il concilio di Nicea aveva fissato al 21 marzo per il computo pasquale. La ricognizione astrometrica del febbraio-marzo 2009 fatta dall'autore viene qui presentata.

  8. Basis for a streamflow forecasting system to Rincón del Bonete and Salto Grande (Uruguay)

    NASA Astrophysics Data System (ADS)

    Talento, Stefanie; Terra, Rafael

    2013-10-01

    This paper presents the basis for the design of streamflow prediction systems for the hydroelectric dams of Rincón del Bonete (Uruguay) and Salto Grande (Uruguay-Argentina). The prediction is made, independently, for each reservoir and each month of the year with two methodologies: data-driven statistical models and hybrid downscaling that includes atmospheric predictors. We determine a set of potential predictors and then fit linear models coupled with variable selection techniques, under the hypothesis of perfectly known predictors. The predictive skill of the schemes outperforms the climatological forecast throughout the year in both reservoirs (except August in Rincón del Bonete). This remains the case even when the forecast lead does not allow for the use of preceding flows as predictors. While in Rincón del Bonete it is not possible to distinguish a period of high predictability, in Salto Grande, there is a robust signal in March-May and October-December.

  9. Loss of helminth species diversity in the large hairy armadillo Chaetophractus villosus on the Tierra del Fuego Island, Argentina.

    PubMed

    Ezquiaga, M C; Abba, A M; Navone, G T

    2016-03-01

    The aim of this work is to compare the taxonomic diversity of parasite species of the large hairy armadillo Chaetophractus villosus in its native range and in another recently introduced population (Tierra del Fuego island), and to evaluate whether the isolation of the latter determines a decrease in its parasitic diversity. Forty specimens from Buenos Aires and Tierra del Fuego Provinces were collected and examined for helminths. Eleven parasite species were found in the native population, and only one species was present in Tierra del Fuego (Trichohelix tuberculata). This may be explained because isolation and climatic conditions prevent encounters between potential host species and infective forms of parasites. Further sampling will be needed throughout the entire Patagonia steppe to confirm how the characteristic parasitic fauna of C. villosus behaves across the armadillo's southern distribution. PMID:25673233

  10. [Tierra del Fuego: the scientific-political construction of exclusion and counter-image of the ideal city dweller].

    PubMed

    Nacach, Gabriela

    2012-01-01

    Due to its late incorporation into the national State, the social, economic and political setting of the Argentine province Tierra del Fuego differed from that of the rest of the national territory. In the construction of dependent otherness, objectifications and representations were imposed by state-related and non-state-related institutions, among other agencies. In this context, the Salesian mission of La Candelaria and Ushuaia's Jail for recidivists stand out as spaces in which biopolitics was concretised. The native population and criminals in Tierra del Fuego were those to be subjugated. The thesis of the extinction of the Indian and the simultaneous exaltation of the criminal as the subject of progress identified the scientific and political mechanisms by which the exclusion of certain social groups (Tierra del Fuego's indigenous population) and the inclusion of others (criminals) were regulated. PMID:22849216

  11. Lumacaftor alone and combined with ivacaftor: preclinical and clinical trial experience of F508del CFTR correction.

    PubMed

    Brewington, John J; McPhail, Gary L; Clancy, John P

    2016-01-01

    Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator protein (CFTR), leading to significant morbidity and mortality. CFTR is a chloride and bicarbonate channel at the epithelial cell membrane. The most common CFTR mutation is F508del, resulting in minimal CFTR at the plasma membrane. Current disease management is supportive, whereas an ultimate goal is to develop therapies to restore CFTR activity. We summarize experience with lumacaftor, a small molecule that increases F508del-CFTR levels at the plasma membrane. Lumacaftor in combination with ivacaftor, a modulator of CFTR gating defects, improves clinical outcome measures in patients homozygous for the F508del mutation. Lumacaftor represents a significant advancement in the treatment of biochemical abnormalities in CF. Further development of CFTR modulators will improve upon current therapies, although it remains unclear whether this approach will provide therapies for all CFTR mutations. PMID:26581802

  12. [I costi farmacologici della terapia di conversione con farmaci biologici nel carcinoma del colon-retto con metastasi epatiche].

    PubMed

    Giuliani, Jacopo; Bonetti, Andrea

    2016-08-01

    Riassunto. Lo scopo di questo studio è quello di valutare i costi dei farmaci (con particolare riferimento alle terapie con farmaci biologici) utilizzati nella terapia di conversione in una popolazione non selezionata di pazienti affetti da carcinoma del colon-retto in stadio avanzato, al fine di ottenere una resezione epatica R0. In questa rassegna sono stati selezionati i report completi e gli aggiornamenti di tutti gli studi clinici randomizzati (di fase II e fase III) che confrontassero almeno 2 regimi di terapia con farmaci biologici in prima linea in pazienti affetti da carcinoma del colon-retto in stadio avanzato di malattia. I costi dei farmaci sono stati ricavati dalla nostra Farmacia Ospedaliera e sono espressi in euro (€). Il nostro studio inizia con la valutazione di 683 abstract. 48 tria sono stati considerati adeguati per una successiva analisi. Una valutazione più approfondita ha portato all'esclusione di 37 trial, lasciando alla valutazione finale 11 studi clinici randomizzati (3 trial di fase II, per un totale di 522 pazienti, e 8 studi di fase III, per un totale di 7191 pazienti). I costi dei farmaci utilizzati nella terapia di conversione aumentano con la sostituzione del 5-fluorouracile con la capecitabina e, in misura maggiore, con l'introduzione degli agenti biologici. In questo lavoro sono presentati due punti chiave. Primo, i costi degli agenti farmacologici utilizzati nei regimi di prima linea a base di agenti biologici più comunemente utilizzati nel trattamento del carcinoma del colon-retto in stadio avanzato sono molto variabili. Secondo, i dati di efficacia dei regimi pubblicati, in termini di tassi di resezione, dipendono dalla selezione dei pazienti, dalle caratteristiche del tumore e dal tipo di schema di terapia. PMID:27571559

  13. Mini-mastoidectomía para anastomosis hipogloso-facial con sección parcial del nervio hipogloso

    PubMed Central

    Campero, Álvaro; Ajler, Pablo; Socolovsky, Mariano; Martins, Carolina; Rhoton, Albert

    2012-01-01

    Introducción: La anastomosis hipogloso-facial es la técnica de elección para la reparación de la parálisis facial cuando no se dispone de un cabo proximal sano del nervio facial. La técnica de anastomosis mediante fresado mastoideo y sección parcial del hipogloso minimiza la atrofia lingual sin sacrificar resultados a nivel facial. Método: La porción mastoidea del nervio facial transcurre por la pared anterior de la AM, a un promedio de 18+/-3 mm de profundidad respecto de la pared lateral. Se debe reconocer la cresta supramastoidea, desde la cual se marca una línea vertical paralela al eje mayor de la AM, 1 cm por detrás de la pared posterior del CAE El fresado se comienza desde la línea medio mastoidea hasta la pared posterior del CAE. Una vez encontrado el nervio facial en el tercio medio del canal mastoideo, el mismo es seguido hacia proximal y distal. Resultados: El abordaje descripto permite acceder al nervio facial intratemporal en su porción mastoidea, y efectuar un fresado óseo sin poner en riesgo al nervio o a estructuras vasculares cercanas. Se trata de un procedimiento técnicamente más sencillo que los abordajes amplios habitualmente utilizados al hueso temporal; no obstante su uso debe ser restringido mayormente a la anastomosis hipogloso-facial. Conclusión: Esta es una técnica relativamente sencilla, que puede ser reproducida por cirujanos sin mayor experiencia en el tema, luego de su paso por el laboratorio de anatomía. PMID:23596555

  14. Centro para la Salud Mundial del NCI anuncia becas de investigación para tecnologías portátiles

    Cancer.gov

    El Centro para la Salud Mundial del NCI (CGH) anunció el otorgamiento de subvenciones que apoyarán el desarrollo y la validación de tecnologías portátiles y de bajo costo para mejorar la detección temprana, el diagnóstico y el tratamiento del cáncer.

  15. Estudio del NCI revela que la obesidad extrema puede acortar la esperanza de vida hasta en 14 años

    Cancer.gov

    Los adultos con obesidad extrema tienen mayor riesgo de morir a edad más joven por cáncer y muchas otras causas entre ellas, enfermedades cardíacas, accidentes cerebrovasculares, diabetes y enfermedades del hígado y los riñones, según estudio del NCI.

  16. Aspectos generales de los exámenes de detección del cáncer (PDQ®)—Versión para pacientes

    Cancer.gov

    Información sobre la medición de la eficacia de los exámenes de detección del cáncer y la evaluación de la solidez de las pruebas obtenidas en estudios de investigación de detección del cáncer.

  17. 76 FR 31848 - Safety Zone; M/V Del Monte Live-Fire Gun Exercise, James River, Isle of Wight, Virginia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-02

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; M/V Del Monte Live-Fire Gun Exercise, James... the live-fire gun exercises on the M/V Del Monte. This action is intended to restrict vessel traffic movement to protect mariners from the hazards associated with the live-fire gun exercise. DATES: This...

  18. 77 FR 4897 - Safety Zone; M/V Del Monte Live-Fire Gun Exercise, James River, Isle of Wight, VA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-01

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; M/V Del Monte Live-Fire Gun Exercise, James... live-fire gun exercises on the M/V Del Monte. This action is intended to restrict vessel traffic movement to protect mariners from the hazards associated with the live-fire gun exercise. DATES: This...

  19. Aspectos generales de los exámenes de detección del cáncer (PDQ®)—Versión para profesionales de salud

    Cancer.gov

    Información sobre la medición de la eficacia de las pruebas de detección del cáncer y la evaluación de la solidez de las pruebas obtenidas en estudios de investigación de detección del cáncer.

  20. Aplicación del Teorema de Nekhorochev para tiempos de estabilidad en Mecánica Celeste

    NASA Astrophysics Data System (ADS)

    Miloni, O.; Núñez, J.; Brunini, A.

    En Mecánica Celeste, uno de los problemas centrales consiste en la determinación de los tiempos de estabilidad. El teorema de Nekhorochev proporciona un método para dicho estudio, para un sistema determinado por un hamiltoniano descripto en las variables acción-ángulo. El trabajo consiste en la acotación tanto del potencial perturbador y de la matriz hessiana del hamiltoniano integrable para determinar luego el tiempo de estabilidad de dicho sistema, donde por estabilidad se entiende la separación en norma infinito en el espacio de las acciones.

  1. Massless Spin-Zero Particle and the Classical Action via Hamilton-Jacobi Equation in Gödel Universe

    NASA Astrophysics Data System (ADS)

    Bahrehbakhsh, A. F.; Momeni, D.; Myrzakulov, R.

    2012-08-01

    In this letter we investigate the separability of the Klein-Gordon and Hamilton-Jacobi equation in Gödel universe. We show that the Klein-Gordon eigen modes are quantized and the complete spectrum of the particle's energy is a mixture of an azimuthal quantum number, m and a principal quantum number, n and a continuous wave number k. We also show that the Hamilton-Jacobi equation gives a closed function for classical action. These results may be used to calculate the Casimir vacuum energy in Gödel universe.

  2. La opacidad atmosférica del CASLEO a ondas milimétricas

    NASA Astrophysics Data System (ADS)

    Bareilles, F.; Olalde, J.; Picardo, C.; Guarrera, L.; Arnal, E. M.; Morras, R.; Perilli, D.; Salazar, P.

    Mediante el uso de un radiómetro que trabaja en la frecuencia de 210 GHz, se han realizado mediciones de la transparencia de la atmósfera a esa frecuencia. Los sitios en los que se han realizado las medidas, corresponden al Cerro Negro de la Tina (Cerro Burek), ubicado a unos 2650 m de altura, y a un sitio ubicado a unos 3400 m de altura, localizado en la Pampa del Jarillal. Las mediciones forman parte de una campaña que cubrirá un lapso de tres años, durante la cual se caracterizan distintas zonas ubicadas en la cordillera. Los resultados que se comunican fueron obtenidos durante el período diciembre de 2002 a septiembre de 2003. Se realiza una comparación preliminar entre la opacidad atmosférica de los lugares mencionados y aquélla de otros sitios en los que se encuentran instaladas facilidades observacionales que operan en la banda milimétrica y submilimétrica del espectro.

  3. AdS-like spectrum of the asymptotically Gödel space-times

    NASA Astrophysics Data System (ADS)

    Konoplya, R. A.; Zhidenko, A.

    2011-09-01

    A black hole immersed in a rotating universe, described by the Gimon-Hashimoto solution, is tested on stability against scalar field perturbations. Unlike the previous studies on perturbations of this solution, which dealt only with the limit of slow universe rotation j, we managed to separate variables in the perturbation equation for the general case of arbitrary rotation. This leads to qualitatively different dynamics of perturbations, because the exact effective potential does not allow for Schwarzschild-like asymptotic of the wave function in the form of purely outgoing waves. The Dirichlet boundary conditions are allowed instead, which result in a totally different spectrum of asymptotically Gödel black holes: the spectrum of quasinormal frequencies is similar to the one of asymptotically anti-de Sitter black holes. At large and intermediate overtones N, the spectrum is equidistant in N. In the limit of small black holes, quasinormal modes (QNMs) approach the normal modes of the empty Gödel space-time. There is no evidence of instability in the found frequencies, which supports the idea that the existence of closed timelike curves (CTCs) and the onset of instability correlate (if at all) not in a straightforward way.

  4. 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.

  5. Challenges of modeling current very large lahars at Nevado del Huila Volcano, Colombia

    NASA Astrophysics Data System (ADS)

    Worni, Raphael; Huggel, Christian; Stoffel, M.; Pulgarín, B.

    2012-03-01

    Nevado del Huila, a glacier-covered volcano in the South of Colombia's Cordillera Central, had not experienced any historical eruptions before 2007. In 2007 and 2008, the volcano erupted with phreatic and phreatomagmatic events which produced lahars with flow volumes of up to about 300 million m3 causing severe damage to infrastructure and loss of lives. The magnitude of these lahars and the prevailing potential for similar or even larger events, poses significant hazards to local people and makes appropriate modeling a real challenge. In this study, we analyze the recent lahars to better understand the main processes and then model possible scenarios for future events. We used lahar inundation depths, travel duration, and flow deposits to constrain the dimensions of the 2007 event and applied LAHARZ and FLO-2D for lahar modeling. Measured hydrographs, geophone seismic sensor data and calculated peak discharges served as input data for the reconstruction of flow hydrographs and for calibration of the models. For model validation, results were compared with field data collected along the Páez and Simbola Rivers. Based on the results of the 2007 lahar simulation, we modeled lahar scenarios with volumes between 300 million and 1 billion m3. The approach presented here represents a feasible solution for modeling high-magnitude flows like lahars and allows an assessment of potential future events and related consequences for population centers downstream of Nevado del Huila.

  6. VizieR Online Data Catalog: 1 Del spectroscopy (Kubat+, 2016)

    NASA Astrophysics Data System (ADS)

    Kubat, J.; Kubatova, B.; Dolezalova, B.; Iliev, L.; Slechta, M.

    2016-02-01

    Visual spectra were observed with the Perek 2-m telescope at the Ondrejov Observatory (Czech Republic) with the slit spectrograph in coude focus. We obtained medium-resolution spectra, (R~13000) with the 700-mm spectrograph focus, in which the SITe CCD 2030x800 chip of 15um pixels was used. Our spectra of 1 Del were taken on 16 September 2007. The data were reduced (bias subtracted, flat-fielded, and wavelength calibrated) using the Image Reduction and Analysis Facility (IRAF1). The spectra were normalized to continuum with a straight line to fit the far wings of the Hα line. SINFONI observations were obtained in service mode at the VLT-UT4 (Yepun) telescope at ESO under Programme-ID 093.D-0172(A) during two nights (6 and 10 June 2014). Spectroscopy of 1 Del was carried out with the SINFONI, the AO-assisted integral field spectrograph in all available near-infrared bands (J, H, and K). (2 data files).

  7. Epidemiological surveillance of cystic echinococcosis in rural population of Tierra del Fuego, Argentina, 1997-2006.

    PubMed

    Zanini, Fabián; Suárez, Carlos; Pérez, Héctor; Elissondo, María C

    2009-03-01

    Cystic echinococcosis (CE) is the most prevalent zoonosis in Tierra del Fuego. In 1997, ulrasonography (US) was selected as the method of choice for the development of population surveys for epidemiological surveillance and early diagnosis in rural population. The aim of this work was to present the results of the epidemiological surveillance of CE by means of US in rural population of Tierra del Fuego, Argentina between 1997 and 2006. The ultrasonographic diagnostic was realized once a year. The population was stratified in children (4 to 17 years) and adults. From each individual, name, age, sex, actual residence and origin were registered. The images compatible with cysts were graded according to location, number and characteristics. A total of 1400 rural inhabitants were examined for CE. From the total of studied individuals, 27 (1.9%) exhibited images compatible with cysts on the abdominal ultrasound scan. Thirteen of these persons were finally diagnosed as having CE. The overall prevalence of CE was 0.9%. This value is in accordance with the decrease in the prevalence observed in the definitive host and the intermediate hosts (sheep and cattle). The absence of cases in children during the studied period, evidence no transmission of the disease to humans in the recent past. PMID:18996221

  8. Large residuals on geoidal heights determined on the Fagnano Lake, Tierra del Fuego-Argentina

    NASA Astrophysics Data System (ADS)

    Gomez, M. E.; Del Cogliano, D.; Perdomo, R.

    2013-05-01

    A new geoid model was developed in Tierra del Fuego and it was evaluated in the area of Fagnano Lake. The model was developed by means of the Equivalent Source Technique combining gravity data, levelling information measured on the province and observations of a GPS buoy on the Fagnano Lake. Those GPS buoy measurements provide information of the mean lake level surface (Del Cogliano et al., 2007). A cross validation process was realized in order to evaluate the model on the lake. What allowed determining a 6 cm geoid in the area of Fagnano Lake. Also, an evaluation of the EGM2008 (Pavlis et al., 2008) was made on the lake. Its behaviour was compared to that observed on the levelling lines. Differences of several decimetres were found when EGM2008 undulations were compared to observed geoid undulations in the lake area. In the regions where EGM2008 has included real gravimetric observations, differences between model and observations were only of a few centimetres. Such model has the particularity that includes fill-in gravity in that region. The above mentioned evaluation derived in an analysis of the effect that not representative gravity information could have on the estimation of geoid undulations in high mountainous regions. We found that this effect could be significant if there is no real information in the computing area (Gomez et al, 2012).

  9. Isolation of Sphaerotilus-Leptothrix strains from iron bacteria communities in Tierra del Fuego wetlands.

    PubMed

    Schmidt, Bertram; Sánchez, Leandro A; Fretschner, Till; Kreps, Gastón; Ferrero, Marcela A; Siñeriz, Faustino; Szewzyk, Ulrich

    2014-11-01

    Sheath-forming iron- and manganese-depositing bacteria belonging to the Sphaerotilus-Leptothrix group (SLG) are widespread in natural and artificial water systems. Known requirements for their growth include the presence of organic substrates and molecular oxygen. High concentrations of reduced iron or manganese, although not necessary for most species, make their growth a noticeable phenomenon. Such microbial communities have been studied mostly in the Northern Hemisphere. Here, we present descriptions of diverse ochre-depositing microbial communities in Tierra del Fuego, Argentina, using a combined approach of microscopical examination, clone library construction and cultivation focused on SLG bacteria. To date, only few SLG type strains are available. The present work increases the number and diversity of cultivated SLG bacteria by obtaining isolates from biofilms and sediment samples of wetlands in Tierra del Fuego. Thirty isolates were selected based on morphological features such as sheath formation and iron/manganese deposition. Five operational taxonomic units (OTUs) were deduced. Sequencing of 16S rRNA genes showed that one OTU is identical to the Leptothrix mobilis Feox-1(T) -sequence while the four remaining OTUs show similarity values related to previously described type strains. Similarity values ranged from 96.5% to 98.8%, indicating possible new species and subspecies. PMID:25098830

  10. EU Del: exploring the onset of pulsation-driven winds in giant stars

    NASA Astrophysics Data System (ADS)

    McDonald, I.; Zijlstra, A. A.; Sloan, G. C.; Lagadec, E.; Johnson, C. I.; Uttenthaler, S.; Jones, O. C.; Smith, C. L.

    2016-03-01

    We explore the wind-driving mechanism of giant stars through the nearby (117 pc), intermediate-luminosity (L ≈ 1600 L⊙) star EU Del (HIP 101810, HD 196610). Atacama Pathfinder Experiment observations of the CO (3-2) and (2-1) transitions are used to derive a wind velocity of 9.51 ± 0.02 km s-1, a 12C/13C ratio of 14^{+9}_{-4} and a mass-loss rate of a few × 10-8 M⊙ yr-1. Analysis of published spectra show the star has a metallicity of [Fe/H] = -0.27 ± ˜0.30 dex. The star's dusty envelope lacks a clear 10-μm silicate feature, despite the star's oxygen-rich nature. Radiative transfer modelling cannot fit a wind acceleration model which relies solely on radiation pressure on condensing dust. We compare our results to VY Leo (HIP 53449), a star with similar temperature and luminosity, but different pulsation properties. We suggest the much stronger mass-loss from EU Del may be driven by long-period stellar pulsations, due to its potentially lower mass. We explore the implications for the mass-loss rate and wind velocities of other stars.

  11. Phenomena that influence high ozone concentrations in the Paso del Norte area

    SciTech Connect

    MacDonald, C.P.; Roberts, P.T.; Main, H.H.; Dye, T.S.; Yarbrough, J.

    1998-12-31

    This paper summarizes the results of analyses of meteorological and air quality data for the 1996 Paso del Norte Ozone Study. The purpose of these data analyses was to develop an understanding of the significant chemical and physical processes which lead to high concentrations of ozone in the Paso del Norte study region which includes El Paso, TX; Sunland Park, NM; and Juarez, Mexico. This analysis has shown that the high ozone concentrations are a result of slow convective boundary layer growth, reduced convective boundary layer depth, light surface winds, and high morning surface ozone precursor concentrations. Overlying meteorological conditions observed during high ozone episodes include an upstream aloft high pressure system, aloft warming, and weak surface pressure gradients. The analysis has also shown that aloft carryover of ozone and ozone precursors does not significantly contribute to the surface ozone concentration. Furthermore, hydrocarbon and NO{sub x} data, although spatially limited, show that the system is most often NO{sub x} rather than VOC limited.

  12. Light scattering from aerosol particles in the El Paso del Norte region / the effect of humidity

    NASA Astrophysics Data System (ADS)

    Medina Calderon, Richard

    Atmospheric aerosols play an important role in climate forcing, through scattering and absorption of the incoming solar radiation. The extinction of light by the presence of atmospheric aerosols was studied using two first-principle models, and corresponding computer codes. In the first model the extinction of light from irregularly shaped aerosol particles was analyzed. In the second model it was assumed that the irregularly shaped aerosol particles were covered by a film of water, and the hygroscopicity and the extinction of light by the aerosols was analyzed. These models were then applied to the Paso del Norte region and their light extinction results compared with a local extinctiometer. The inter-comparison of the models extinction results and the extinctiometer values were well correlated. It was observed that for high humidity days the model that used an aerosol particle covered with a water film correlated better with the experimental extinctiometer measurements. While these two models were validated in the Paso del Norte region, they are also applicable to any other region, under humid or dry atmospheric conditions.

  13. Paso del Norte pilot border study of ozone precursors and air toxics

    SciTech Connect

    Zielinska, B.; Sheetz, L.; Harshfield, G.

    1996-12-31

    A comprehensive monitoring program for ozone precursors and air toxics in the Paso del Norte border area is planned by the U.S. EPA for the Summer of 1996. A pilot study was carried out in October 1995 in the Paso del Norte area (El Paso, Texas, Ciudad Juarez, Chihuahua, and Sunland Park, New Mexico) to test the appropriateness of proposed sampling and analysis methods and to provide preliminary data to be used for planning the Summer 1996 study. Two monitoring sites were selected, one in Ciudad Juarez, and one in the El Paso area. Samples were collected every second day from October 21 to October 31, from 0300 to 0900 hr using stainless steel canisters (for VOC in the C{sub 2}-C{sub 12} range), Tenax-TA solid adsorbent cartridges (for C{sub 8}-C{sub 20} hydrocarbons). DNPH impregnated C{sub 18} Sep-Pack cartridges (for carbonyl compounds) and Teflon impregnated glass fiber filters followed by PUF/YAD/PUF {open_quotes}sandwich{close_quotes} cartridges (for SVOC). This paper discusses the data set obtained from the analyses of these samples. 6 refs., 7 figs.

  14. Aparición del cometa Hale - BOPP C / 1995-01

    NASA Astrophysics Data System (ADS)

    Arquiola, A.

    El Cometa Hale - Bopp fue observado a partir de la 10ma. magnitud con el telescopio de 300mm de abertura a f/6.5. En esas primeras observaciones desde luego no hubo mucho detalle. A su vez las posiciones del cometa para nuestro hemisferio no fueron favorables, solamente asomó por el horizonte N.O. para nuestra latitud cuando se alejaba de la Tierra. Se registró la observación visualmente con binoculares 10 x 50, y fotográficamente con un Telezoom de 210mm a f/4,5 con película 400 ASA color. Todas las imágenes fueron procesadas y digitalizadas a fin de obtener las diferentes escalas de brillo. El aspecto que presentó para nuestra posición geográfica fue discreta ya que tuvo su máximo brillo cuando era visible desde el hemisferio norte. Presentó la clásica cola de polvo curva, y con su aspecto casi estelar, destacándose entre la luminosidad del crepúsculo. Instrumentos Utilizados: Telezoom de 210mm a f/4.5, Telescopio refractor de 80mm a f/15, Binocular 10 x 50

  15. Receiver Function Analyses of Uturuncu Volcano, Bolivia and Lastarria/Cordon Del Azufre Volcanoes, Chile

    NASA Astrophysics Data System (ADS)

    Mcfarlin, H. L.; Christensen, D. H.; Thompson, G.; McNutt, S. R.; Ryan, J. C.; Ward, K. M.; Zandt, G.; West, M. E.

    2014-12-01

    Uturuncu Volcano and a zone between Lastarria and Cordon del Azufre Volcanoes (also calledLazufre), have seen much attention lately because of significant and rapid inflation of one to twocentimeters per year over large areas. Uturuncu is located near the Bolivian-Chilean border, andLazufre is located near the Chilean-Argentine border. The PLUTONS Project deployed 28broadband seismic stations around Uturuncu Volcano, from April 2009 to Octobor 2012, and alsodeployed 9 stations around Lastarria and Cordon del Azufre volcanoes, from November, 2011 toApril 2013. Teleseismic receiver functions were generated using the time-domain iterativedeconvolution algorithm of Ligorria and Ammon (1999) for each volcanic area. These receiverfunctions were used to better constrain the depths of magma bodies under Uturuncu and Lazufre,as well as the ultra low velocity layer within the Altiplano-Puna Magma Body (APMB). Thelow velocity zone under Uturuncu is shown to have a top around 10 km depth b.s.l and isgenerally around 20 km thick with regional variations. Tomographic inversion shows a well resolved,near vertical, high Vp/Vs anomaly directly beneath Uturuncu that correlates well with adisruption in the receiver function results; which is inferred to be a magmatic intrusion causing alocal thickening of the APMB. Preliminary results at Lazufre show the top of a low velocityzone around 5-10 km b.s.l with a thickness of 15-30 km.

  16. The Last Glacial Maximum and Termination in the Torres del Paine Region, Southern South America

    NASA Astrophysics Data System (ADS)

    Garcia, J.; Hall, B. L.; Kaplan, M. R.; Vega, R. M.; Binnie, S.; Gómez, G.; Santana, F.

    2012-12-01

    Deciphering the timing, structure and termination of the local last glacial maximum (LGM) throughout Patagonia (42-55 S) remains one of the key unsolved paleoclimate questions in Quaternary sciences. During the last glaciation, the Patagonian ice sheet formed one ice body along the Patagonian Andes (42-55 S) in southern South America, but previous work has revealed different spatiotemporal ice dynamics along the eastern and western ice margins. The Patagonian Andes is the only landmass that exists at this latitude confronting the southern westerly wind belt, which seems to have played a key role in past glacial and climate changes. Therefore, reconstructing southern Andes glacier history constitutes a key element for understanding the causes of glaciations in the Southern Hemisphere. Major progress has been made to document the local Late-Pleistocene glacier history, particularly in response to recent application of exposure-cosmogenic dating technique in the region, although only sparse well-dated paleoclimate records exist in this vast area. LGM moraine-based records in south Patagonia (~48-55 S) have been developed for the Strait of Magellan area, where full glacial conditions seems to have occurred between ~28.0 - 17.5 ka. Despite that these data seem to confirm previous glacial chronologies developed in north Patagonia and the Chilean Lake District (40-42 S), recent works in Torres del Paine and Última Esperanza basins (50-51 S), suggest that glacial maximum conditions may have occurred earlier (i.e., during Marine Isotope Stage 3) and that ice extent could have been twice the size of previously thought. Here, we discuss paleoclimatological implications from our 10Be and 26Al-dating program of moraines in the Torres del Paine region in southern Patagonia. We focused our efforts in the previously undated Río de las Viscachas (RV) I and II moraines, which occur distal to the late-glacial TDP II, III and IV moraines that enclose present lake bodies at the

  17. Attic dust analysis approach for evaluation of heavy metal deposition in the El Paso Del Norte Region

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During the 90 years from 1887 to 1977, a large smelter in the El Paso Del Norte region of North America smelted many ores including copper, lead, and zinc. In order to identify the patterns of heavy metal dispersion from the smelter, we sampled attic dust and dust from undisturbed surfaces in 15 bu...

  18. Developing Flexible Dual Master's Degree Programs at UPAEP (Universidad Popular Autonoma del Estado de Puebla) and OSU (Oklahoma State University)

    ERIC Educational Resources Information Center

    Fabregas-Janeiro, Maria G.; de la Parra, Pablo Nuno

    2012-01-01

    In 2006, UPAEP (Universidad Popular Autonoma del Estado de Puebla) and OSU (Oklahoma State University) signed a MOU (memorandum of understanding) to develop more than 20 dual master's degree programs. This special partnership has allowed students from Mexico and the United States to study two master degree programs, in two languages, in two…

  19. Disseminated Medulloblastoma in a Child with Germline BRCA2 6174delT Mutation and without Fanconi Anemia.

    PubMed

    Xu, Jingying; Margol, Ashley Sloane; Shukla, Anju; Ren, Xiuhai; Finlay, Jonathan L; Krieger, Mark D; Gilles, Floyd H; Couch, Fergus J; Aziz, Meraj; Fung, Eric T; Asgharzadeh, Shahab; Barrett, Michael T; Erdreich-Epstein, Anat

    2015-01-01

    Medulloblastoma, the most common malignant brain tumor in children, occurs with increased frequency in individuals with Fanconi anemia who have biallelic germline mutations in BRCA2. We describe an 8-year-old child who had disseminated anaplastic medulloblastoma and a deleterious heterozygous BRCA2 6174delT germline mutation. Molecular profiling was consistent with Group 4 medulloblastoma. The posterior fossa mass was resected and the patient received intensive chemotherapy and craniospinal irradiation. Despite this, the patient succumbed to a second recurrence of his medulloblastoma, which presented 8 months after diagnosis as malignant pleural and peritoneal effusions. Continuous medulloblastoma cell lines were isolated from the original tumor (CHLA-01-MED) and the malignant pleural effusion (CHLA-01R-MED). Here, we provide their analyses, including in vitro and in vivo growth, drug sensitivity, comparative genomic hybridization, and next generation sequencing analysis. In addition to the BRCA2 6174delT, the medulloblastoma cells had amplification of MYC, deletion at Xp11.2, and isochromosome 17, but no structural variations or overexpression of GFI1 or GFI1B. To our knowledge, this is the first pair of diagnosis/recurrence medulloblastoma cell lines, the only medulloblastoma cell lines with BRCA2 6174delT described to date, and the first reported case of a child with medulloblastoma associated with a germline BRCA2 6174delT who did not also have Fanconi anemia. PMID:26380221

  20. Mineralogy of Inclusions in the Campo Del Cielo and Mont Dieu Irons and Segregation of Partial Melts

    NASA Astrophysics Data System (ADS)

    Takeda, H.; Ishii, T.; Otsuki, M.

    2001-03-01

    To find partial melt segregation, we studied two new irons. Segregations of albite and chromite were found in Campo del Cielo and ameboidal FeS in Mont Dieu with the same shape as in IIE irons together with minor Cr diopside and Na,K-rich glass.