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Sample records for bata blanca durante

  1. Experimental Evaluation of Behavioral Activation Treatment of Anxiety (BATA) in Three Older Adults

    ERIC Educational Resources Information Center

    Turner, Jarrod S.; Leach, David J.

    2010-01-01

    This report describes three single-case experimental evaluations of Behavioral Activation Treatment of Anxiety (BATA) applied with a 51-year-old male, a 62-year-old female, and a 53-year-old female, each of whom met DSM-IV criteria for anxiety. Each case was a clinical replication of an initial trial of BATA reported in Turner and Leach (2009).…

  2. Synthesis and Optical Characterization of Red-Emitting BaTa2O6:Eu(3+) Phosphors.

    PubMed

    İlhan, Mustafa; Ekmekçi, Mete Kaan; Mergen, Ayhan; Yaman, Cemalettin

    2016-09-01

    Undoped and Eu(3+) doped BaTa2O6 phosphors were synthesized via solid state reaction method and characterized by using XRD, SEM-EDS and photoluminescence (PL) analyses. The XRD results revealed that the crystal structure of BaTa2O6 allowed up to 10 mol% levels of Eu(3+) ions due to the TTB characteristic network of adjacent octahedrals. SEM-EDS analyses confirmed the formation of BaTa2O6 structure and EuTaO4 secondary phase. BaTa2O6:Eu(3+) phosphors exhibited orange and red emissions at 592.2 nm and 615.7 nm in the visible region respectively. The Commission Internationale d'Eclairage (CIE) chromaticity coordinates of the BaTa2O6:Eu(3+) phosphors that excited at λ ex = 400 nm ranged from orangish-red to pinkish-red depending on increasing Eu(3+) concentration. PMID:27325113

  3. Structural and Luminescence Properties of Sm(3+) Doped TTB -Type BaTa2O6 Ceramic Phosphors.

    PubMed

    Ekmekçi, Mete Kaan; İlhan, Mustafa; Başak, Ali Sadi; Deniz, Sabahattin

    2015-11-01

    Pure and 0.5 to 10 mole% Sm(3+) doped TTB (tetragonal tungsten bronze)-type BaTa2O6 ceramic phosphor was produced by the solid state reaction method which performed at 1425 °C for 20 h. XRD and SEM analysis indicated single TTB phase for undoped and 0.5 to 10 mole% Sm(3+) doped BaTa2O6 structures. SEM also showed that the BaTa2O6 grain size decreased with the increasing content of Sm(3+). Optical analysis indicated significant emissions in the visible spectral region as green (λ = 562.7 nm) and orange-reddish (λ = 597.1 nm). The emission intensity increased with the increasing doping concentration up to 2.5 mole%, and then decreased due to the concentration quenching effect. PMID:26410773

  4. Natural Analog Studies at Pena Blanca, Mexico

    SciTech Connect

    A.M. Simmons

    2005-07-11

    The significance of the Pena Blanca uranium deposits in the State of Chihuahua, Mexico as potential natural analogs for a nuclear waste repository in unsaturated welded tuff was first recognized in the 1980s. In the 1970s, the Pena Blanca region was a major target of uranium exploration and exploitation by the Mexican government. Since then the Nopal I uranium deposit has been studied extensively by researchers in the U.S., Mexico, and Europe. The Nopal I deposit represents an environment similar to that of the proposed high-level radioactive waste repository at Yucca Mountain in many ways. Both are located in semi-arid regions. Both are located in Tertiary rhyolitic tuffs overlying carbonate rocks that have been subjected to basin and range-style tectonic deformation. Both are located in a chemically oxidizing, unsaturated zone 200 m or more above the water table. The alteration of uraninite to secondary minerals at Nopal I may be similar to the alteration of uranium fuel rods in this type of setting. Investigations at Nopal I and in the surrounding Sierra Pena Blanca have included detailed outcrop mapping, hydrologic and isotopic studies of flow and transport, studies of mineral alteration, modeling, and performance assessment.

  5. Urban epidemiology of Schistosoma intercalatum in the city of Bata, Equatorial Guinea.

    PubMed

    Simarro, P P; Sima, F O; Mir, M

    1990-09-01

    In a cross sectional study, 1221 individuals were enrolled to determine the urban epidemiology of Schistosoma intercalatum in the city of Bata, Equatorial Guinea. Bulinus forskalii was the only intermediate host for schistosomes found in the study areas. The only Schistosoma species detected in faeces was S. intercalatum. However, no Schistosoma eggs were found in urine. The overall prevalence of S. intercalatum infection was 21.2%. Although infected subjects were found in all age groups, peak prevalence and highest parasite load occurred in 5-14 years old children. But only 38 individuals (3.1%) had infection with more than 400 eggs per gram faeces. Thirty out of these (78.9%), were children between 5 and 14 years of age. In the heavily infected subjects (greater than 400 eggs/g. faeces) highly significantly more diarrhoea with microscopic and macroscopic blood in stool was present (p less than 0.0001). PMID:2255841

  6. Rural-Urban Differences in Household Treatment-Seeking Behaviour for Suspected Malaria in Children at Bata District, Equatorial Guinea

    PubMed Central

    Romay-Barja, Maria; Jarrin, Inma; Ncogo, Policarpo; Nseng, Gloria; Sagrado, Maria Jose; Santana-Morales, Maria A.; Aparcio, Pilar; Valladares, Basilio; Riloha, Matilde; Benito, Agustin

    2015-01-01

    Background Malaria remains a major cause of morbidity and mortality among children under five years old in Equatorial Guinea. However, little is known about the community management of malaria and treatment-seeking patterns. We aimed to assess symptoms of children with reported malaria and treatment-seeking behaviour of their caretakers in rural and urban areas in the Bata District. Methodology A cross-sectional study was conducted in the district of Bata and 440 houses were selected from 18 rural villages and 26 urban neighbourhoods. Differences between rural and urban caregivers and children with reported malaria were assessed through the chi-squared test for independence of categorical variables and the t-Student or the non-parametric Mann-Whitney test for normally or not-normally distributed continuous variables, respectively. Results Differences between rural and urban households were observed in caregiver treatment-seeking patterns. Fever was the main symptom associated with malaria in both areas. Malaria was treated first at home, particularly in rural areas. The second step was to seek treatment outside the home, mainly at hospital and Health Centre for rural households and at hospital and private clinic for urban ones. Artemether monotherapy was the antimalarial treatment prescribed most often. Households waited for more than 24 hours before seeking treatment outside and delays were longest in rural areas. The total cost of treatment was higher in urban than in rural areas in Bata. Conclusions The delays in seeking treatment, the type of malaria therapy received and the cost of treatment are the principal problems found in Bata District. Important steps for reducing malaria morbidity and mortality in this area are to provide sufficient supplies of effective antimalarial drugs and to improve malaria treatment skills in households and in both public and private sectors. PMID:26284683

  7. Slope stability of moraines, Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Klimes, J.; Novotny, J.

    2012-12-01

    Landslides originating from inner slopes of moraine dams are often capable of producing glacial lakes outburst floods (GLOFs). Therefore assessing stability conditions of the moraines is important for predicting this potentially damaging phenomenon. Characteristics of the basic mechanical properties of the material and geophysical investigations were applied to collect necessary information for slope stability assessment of the Palcacocha Lake moraine dam, Peru. The lake is situated in the Cordillera Blanca Mts. at the altitude of about 4,500m asl and produced catastrophic GLOF in 1941. Another minor flood originated in 2003 due to landslide impact into the lake. Detailed investigations of this landslide site included geomorphological mapping, geophysical investigations and characterization of basic mechanical properties of the forming material. Geomorphological mapping identified dormant landslide with scarp up to 2m high which developed on the edge of the inner moraine slope. It is conditioned by set of parallel extension trenches which also affected the origin of 2003 landslide. Within its scarp area, significant water bearing layer was noticed around 10 m bellow the moraine surface. Three profiles were investigated using electric resistivity tomography performed on 4poing light instrument with 24 electrodes and with spacing ranging from 1 to 4m. Results helped to verify geometry of the main shear plane of the mapped landslide as well as the spacing and depth of extension trenches. Significant heterogeneity in the moraine resistivity characteristics was found. The high resistivity regions are explained by rock block accumulation whereas the low resistivity may represent wet layers within the moraine body. Grain size distribution of 33 disturbed soil samples originating from moraine material within the Cordillera Blanca Mts., Peru were determined and classified according to the UCSC classification system. The samples were taken from moraine dams and slopes

  8. Self-reported adherence to antiretroviral therapy in HIV+ population from Bata, Equatorial Guinea.

    PubMed

    Salmanton-García, Jon; Herrador, Zaida; Ruiz-Seco, Pilar; Nzang-Esono, Jesús; Bendomo, Veronica; Bashmakovic, Emma; Nseng-Nchama, Gloria; Benito, Agustín; Aparicio, Pilar

    2016-05-01

    The human immunodeficiency virus (HIV) and the acquired immune deficiency syndrome (AIDS) represent a serious public health problem in Equatorial Guinea, with a prevalence of 6.2% among adults. the high-activity antiretroviral treatment (HAART) coverage data is 10 points below the overall estimate for Sub-Saharan Africa, and only 61% patients continue with HAART 12 months after it started. This study aims to assess HAART adherence and related factors in Litoral Province of Equatorial Guinea. In this cross-sectional study, socio-demographic and clinical data were collected at Regional Hospital of Bata, during June-July 2014. Adherence to treatment was assessed by using the Spanish version of CEAT-VIH. Bivariate and linear regression analyses were employed to assess HAART adherence-related factors. We interviewed 50 men (35.5%) and 91 women (64.5%), with a mean age of 47.7 ± 8.9 and 36.2 ± 11.2, respectively (p < .001). Overall, 55% patients had low or insufficient adherence. CEAT-VIH score varied by ethnic group (p = .005). There was a positive correlation between CEAT-VIH score and current CD4 T-cells count (p = .013). The Cronbach's α value was 0.52. To our knowledge, this is the first study to assess HAART adherence in Equatorial Guinea. Internal reliability for CEAT-VIH was low, nonetheless the positive correlation between the CEAT-VIH score and the immunological status of patients add value to our findings. Our results serve as baseline for future research and will also assist stakeholders in planning and undertaking contextual and evidence-based policy initiatives. PMID:26698540

  9. THE PENA BLANCA NATURAL ANALOGUE PERFORMANCE ASSESSMENT MODEL

    SciTech Connect

    G.J. Saulnier Jr; W. Statham

    2006-03-10

    The Nopal I uranium mine in the Sierra Pena Blanca, Chihuahua, Mexico serves as a natural analogue to the Yucca Mountain repository. The Pena Blanca Natural Analogue Performance Assessment Model simulates the mobilization and transport of radionuclides that are released from the mine and transported to the saturated zone. the Pena Blanca Natural Analogue Model uses probabilistic simulations of hydrogeologic processes that are analogous to the processes that occur at the Yucca Mountain site. The Nopal I uranium deposit lies in fractured, welded, and altered rhyolitic ash flow tuffs that overlie carbonate rocks, a setting analogous to the geologic formations at the Yucca Mountain site. The Nopal I mine site has the following characteristics as compared to the Yucca Mountain repository site. (1) Analogous source: UO{sub 2} uranium ore deposit = spent nuclear fuel in the repository; (2) Analogous geologic setting: fractured, welded, and altered rhyolitic ash flow tuffs overlying carbonate rocks; (3) Analogous climate: Semiarid to arid; (4) Analogous geochemistry: Oxidizing conditions; and (5) Analogous hydrogeology: The ore deposit lies in the unsaturated zone above the water table. The Nopal I deposit is approximately 8 {+-} 0.5 million years old and has been exposed to oxidizing conditions during the last 3.2 to 3.4 million years. The Pena Blanca Natural Analogue Model considers that the uranium oxide and uranium silicates in the ore deposit were originally analogous to uranium-oxide spent nuclear fuel. The Pena Blanca site has been characterized using field and laboratory investigations of its fault and fracture distribution, mineralogy, fracture fillings, seepage into the mine adits, regional hydrology, and mineralization that shows the extent of radionuclide migration. Three boreholes were drilled at the Nopal I mine site in 2003 and these boreholes have provided samples for lithologic characterization, water-level measurements, and water samples for laboratory

  10. THE PENA BLANCA NATURAL ANALOGUE PERFORMANCE ASSESSMENT MODEL

    SciTech Connect

    G. Saulnier and W. Statham

    2006-04-16

    The Nopal I uranium mine in the Sierra Pena Blanca, Chihuahua, Mexico serves as a natural analogue to the Yucca Mountain repository. The Pena Blanca Natural Analogue Performance Assessment Model simulates the mobilization and transport of radionuclides that are released from the mine and transported to the saturated zone. The Pena Blanca Natural Analogue Performance Assessment Model uses probabilistic simulations of hydrogeologic processes that are analogous to the processes that occur at the Yucca Mountain site. The Nopal I uranium deposit lies in fractured, welded, and altered rhyolitic ash-flow tuffs that overlie carbonate rocks, a setting analogous to the geologic formations at the Yucca Mountain site. The Nopal I mine site has the following analogous characteristics as compared to the Yucca Mountain repository site: (1) Analogous source--UO{sub 2} uranium ore deposit = spent nuclear fuel in the repository; (2) Analogous geology--(i.e. fractured, welded, and altered rhyolitic ash-flow tuffs); (3) Analogous climate--Semiarid to arid; (4) Analogous setting--Volcanic tuffs overlie carbonate rocks; and (5) Analogous geochemistry--Oxidizing conditions Analogous hydrogeology: The ore deposit lies in the unsaturated zone above the water table.

  11. Cretaceous stratigraphy and biostratigraphy, Sierra Blanca basin, southeastern New Mexico

    SciTech Connect

    Lucas, S.G. ); Anderson, O.R. )

    1994-03-01

    The Sierra Blanca basin of Otero and Lincoln counties, New Mexico contains a Lower (upper Albian)-Upper (Santonian) Cretaceous section of marine and nonmarine strata as much as 700 m thick which represent the upper part of a regressive cycle followed by two transgressive-regressive deposition cycles. The lower 55 m of the Cretaceous section are the same tripartite Dakota Group units recognized in Guadalupe and San Miguel counties: basal Mesa Rica Sandstone (late Albian), medial Pajarito formation (late Albian) and upper Romeroville sandstone (earliest Cenomanian). The Mesa Rica and Pajarito represent a regression and are overlain disconformably by the transgressive Romeroville sandstone. Overlying transgressive marine clastics and minor carbonates of the Mancos Shale are as much as 73 m thick and include the early Turonian Greenhorn Limestone. The overlying Tres Hermanos formation (up to 91 m thick) consists of the (ascending order) Atarque sandstone and the Carthage and Fite Ranch sandstone members. These strata represent a mid-Turonian regression in response to regional tectonism (Atarque and Carthage), followed by a transgression (Fite Ranch sandstone) that ended in the deposition of the D-Cross Tongue of the Mancos Shale and Fort Hays Member of the Niobrara Formation during the late Turonian. The subsequent regression began with the Coniacian Gallup Sandstone (55 m) followed by coal-bearing Crevasse Canyon Formation (up to 244 m thick). The Coniacian-Santonian Crevasse Canyon Formation, the youngest Cretaceous unit in the basin, is disconformably overlain by middle Eocene conglomerates and red-bed siliciclastics of the Cub Mountain formation. Dakota Group age determinations in the Sierra Blanca basin are those of well-dated sections to the north, but ammonites and inoceramid bivalves from the Sierra Blanca basin provide precise age control for Cenomanian-Santonian marine and marginal marine strata and palynology and megafossil plants for nonmarine strata.

  12. De Novo Transcriptome Assembly and Annotation of the Leaves and Callus of Cyclocarya Paliurus (Bata1) Iljinskaja.

    PubMed

    Xu, Xiaoxiang; Yin, Zhongping; Chen, Jiguang; Wang, Xiaoqiang; Peng, Dayong; Shangguan, Xinchen

    2016-01-01

    Cyclocarya Paliurus (Bata1) Iljinskaja contains various bioactive secondary metabolites especially in leaves, such as triterpenes, flavonoids, polysaccharides and alkaloids, and its leaves are widely used as an hyperglycemic tea in China. In the present paper, we sequenced the transcriptome of the leaves and callus of Cyclocarya Paliurus using Illumina Hiseq 4000 platform. After sequencing and de novo assembly, a total of 65,654 unigenes were generated with an N50 length of 1,244bp. Among them, 35,041 (53.37%) unigenes were annotated in NCBI Non-Redundant database, 19,453 (29.63%) unigenes were classified into Gene Ontology (GO) database, and 7,259 (11.06%) unigenes were assigned to Clusters of Orthologous Group (COG) categories. Furthermore, 11,697 (17.81%) unigenes were mapped onto 335 pathways in Kyoto Encyclopedia of Genes and Genomes (KEGG), among which 1,312 unigenes were identified to be involved in biosynthesis of secondary metabolites. In addition, a total of 11,247 putative simple sequence repeats (SSRs) were detected. This transcriptome dataset provides a comprehensive sequence resource for gene expression profiling, genetic diversity, evolution and further molecular genetics research on Cyclocarya Paliurus. PMID:27483006

  13. De Novo Transcriptome Assembly and Annotation of the Leaves and Callus of Cyclocarya Paliurus (Bata1) Iljinskaja

    PubMed Central

    Xu, Xiaoxiang; Yin, Zhongping; Chen, Jiguang; Wang, Xiaoqiang; Peng, Dayong; Shangguan, Xinchen

    2016-01-01

    Cyclocarya Paliurus (Bata1) Iljinskaja contains various bioactive secondary metabolites especially in leaves, such as triterpenes, flavonoids, polysaccharides and alkaloids, and its leaves are widely used as an hyperglycemic tea in China. In the present paper, we sequenced the transcriptome of the leaves and callus of Cyclocarya Paliurus using Illumina Hiseq 4000 platform. After sequencing and de novo assembly, a total of 65,654 unigenes were generated with an N50 length of 1,244bp. Among them, 35,041 (53.37%) unigenes were annotated in NCBI Non-Redundant database, 19,453 (29.63%) unigenes were classified into Gene Ontology (GO) database, and 7,259 (11.06%) unigenes were assigned to Clusters of Orthologous Group (COG) categories. Furthermore, 11,697 (17.81%) unigenes were mapped onto 335 pathways in Kyoto Encyclopedia of Genes and Genomes (KEGG), among which 1,312 unigenes were identified to be involved in biosynthesis of secondary metabolites. In addition, a total of 11,247 putative simple sequence repeats (SSRs) were detected. This transcriptome dataset provides a comprehensive sequence resource for gene expression profiling, genetic diversity, evolution and further molecular genetics research on Cyclocarya Paliurus. PMID:27483006

  14. Holocene denudation and landscape deformation in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Hodson, K. R.; Hall, S. R.; Michalak, M.; Farber, D.; Hourigan, J. K.

    2012-12-01

    Active orogenic systems are subject to a host of processes that influence their topographic and structural evolution. Broadly speaking, these processes can be divided into two general groups: tectonics and climate. Both are capable of inducing profound changes within an orogen, although many specifics regarding their forcings, interactions, and feedbacks remain unclear. Here, we address the evolution of the Cordillera Blanca Mountain Range of northern Peru: an elevated, high-relief, 200km long string of glaciated peaks along the spine of the Andes. The striking Cordillera Blanca Detachment Fault (CBDF) is actively facilitating the production of several kilometers of relief along the western flank of the range, and abundant records of past glaciations span from >440 ka to the present. Thus, tectonics (active faulting) and climate (glacial erosion) are operating in tandem to produce some of the highest topography in the western hemisphere, affording the opportunity to investigate their potential interactions. Through the use of cosmogenic 10Be, low temperature thermochronology and digital terrain analysis we characterize the rates of landscape change as well as the present morphology. Significant variation in range elevation (maximum, mean, modal and minimum), relief (local and within basins) and slope (maximum, mean and minimum) exist along the strike of the range, potentially reflecting variable displacement along the CBDF, varying degrees of glacial erosion along the mountain range, or some combination of the two. The morphology of the adjacent supradetachment basin varies as well, containing zones with distinct styles of faulting and basin growth likely defined by the segmentation history of the CBDF. New thermochronologic data extends the current dataset, which we combine with 10Be basin-averaged erosion rates from basins along the range. These two datasets constrain the exhumational and erosional history of the range-forming Cordillera Blanca Batholith from the

  15. The Cordillera Blanca normal fault and its contribution to the Andean topographic evolution (northern Peru)

    NASA Astrophysics Data System (ADS)

    Margirier, Audrey; Robert, Xavier; Schwartz, Stéphane; Audin, Laurence

    2015-04-01

    Nature and localization of Quaternary tectonics remains largely unconstrained in Peruvian Andes as well as the mechanism driving rock uplift. The Cordillera Blanca normal fault accommodates extension in a convergent context. The fault system trends parallel to the subduction zone, just above the Peruvian flat-slab, and separate the Cordilleras Blanca and Negra. The Cordillera Blanca batholith (8-5 Ma) is an elongated pluton, emplaced at ~6 km depth in the Jurassic sedimentary country rocks. The Cordillera Blanca range (6768 m) that comprises the highest Peruvian peak built the footwall of the fault. The ~200 km-long fault has showed ~4500 m of vertical displacement since 5 Ma. This normal fault is described as active despite the lack of historical seismicity and constitutes a striking singularity within the prevailing compressional setting of the Andean orogeny. This region is a perfect target to explore the contribution of large normal fault in relief building. Our goals are to determine if the fault was pre-existing before the Cordillera Blanca batholith emplacement, when it has been reactivated and how does it interact with the batholith exhumation. For that purpose, we focus on brittle deformation analysis from a regional scale (faults trends) to outcrop scale (fault planes, striaes and kinematics). We present here new structural data and focal mechanisms indicating a senestral transtensive component on the Cordillera Blanca normal fault and a regional extensional regime in the Cordillera Negra area. We compare the paleotensors obtained from the inversion of the microstructural data and focal mechanisms with the exhumation history deduced from the thermochronological data to constrain the role of the normal fault in relation with relief building. We propose that the Cordillera Blanca normal fault is an inherited tectonic feature reactivated in transtension after the slab flattening at ~8 Ma. The differential exhumation of the Cordillera Blanca with respect to

  16. Characterisation of the Bahía Blanca estuary by data analysis and numerical modelling

    NASA Astrophysics Data System (ADS)

    Campuzano, Francisco Javier; Pierini, Jorge O.; Leitão, Paulo C.; Gómez, Eduardo A.; Neves, Ramiro J.

    2014-01-01

    The Bahía Blanca estuary is a complex system of channels and tidal flats where the most important deep water harbour system of Argentina is located. The main goal of the present work was to obtain a hydrodynamic conceptual model for the Bahía Blanca coastal area. For this reason, a combined analysis of observed data and numerical modelling has been performed for the whole area. The gained knowledge on the system hydrodynamics could aid in the decision support for navigation security, waste water discharges management, sediment dredging and rejection operations among other applications. Due to the Bahía Blanca coastal vast area, hydrodynamic observations are scarce and located near the populated areas. In order to describe the hydrodynamics of such a complex and large system, the analysed tidal and current data from different periods have been completed through numerical modelling. Data analysis served to determine the main processes governing the Bahía Blanca hydrodynamics, to characterise the area using general descriptors, to provide inputs for the numerical model and to aid in evaluating its performance. In addition, a 2-dimensional application was set up using the MOHID water modelling system for the Bahía Blanca estuary. This application aimed to gain a better understanding of the system dynamics, to explain and test the consistency of the observed data and to reproduce the processes taking place. Model results were in good agreement with the analysed data and served to confirm an inconsistency found on the sea level observations. The combination of both methodologies served to further describe the hydrodynamic processes governing this coastal area and also to obtain a conceptual model for the water and property circulation in the Bahía Blanca estuary.

  17. Miocene Blanca Fan, Northern Channel Islands, California: Small fans reflecting tectonism and volcanism

    USGS Publications Warehouse

    McLean, H.; Howell, D.G.

    1984-01-01

    Blanca fan is a submarine fan composed of Miocene volcaniclastic strata. Parts of the fan system are exposed on Santa Cruz and Santa Rosa Islands, and possibly correlative strata crop out on San Miguel and Santa Catalina Islands. The Blanca fan and underlying breccia reflect regional transcurrent faulting in the California Continental Borderland and development of a system of rapidly subsiding basins and uplifted linear ridges during early and middle Miocene time. Erosion of uplifted crystalline basement rocks followed by the onset of silicic volcanism created linear sediment sources for the alluvial and submarine fans, respectively. ?? 1984 Springer-Verlag New York Inc.

  18. Flying High With Civil Air Patrol: The Sierra Blanca Civil Air Patrol Squadron.

    ERIC Educational Resources Information Center

    Carnicom, Gene E.

    The Sierra Blanca Civil Air Patrol (CAP) Cadet Squadron from Mescalero, New Mexico, is a program funded by the tribe and the state of New Mexico for Mescalero Apache youth. The national CAP Cadet Program promotes moral leadership, aerospace education, leadership, and physical fitness; Mescalero cadets have learned self-confidence and leadership…

  19. STRATIGRAPHY OF THE PB-1 WELL, NOPAL 1 URANIUM DEPOSIT, PENA BLANCA, CHIHUAHUA, MEXICO

    SciTech Connect

    P. Dobson

    2005-09-14

    The objectives of this report are: (1) Stratigraphic study part of integrated research project examining migration of radionuclides at Pena Blanca; (2) Immediate objectives of study include: locate stratigraphic contacts in third dimension; measure rock properties (matrix permeability, porosity, mineralogy, cation exchange capacity) of cored section; determine fracture frequency and orientation; (3) Results of study serve as primary inputs to flow and transport models.

  20. Composition and spectrum of cosmic rays at the knee measured by the CASA-BLANCA experiment

    NASA Astrophysics Data System (ADS)

    Fowler, Joseph Westbrook

    2000-07-01

    The energy spectrum and primary composition of cosmic rays with energy between 0.25PeV and 30PeV have been studied using the CASA-BLANCA detector. In this energy range, a ``knee'' in the spectrum has been recognized for over 40 years, but the astrophysical origins of the knee remain unknown. Measuring the spectrum and elemental composition of cosmic rays near the knee can help to address the problem. The favored model of acceleration in supernova shock waves predicts that cosmic rays with energy above 10PeV are heavy nuclei. The measurements were made by BLANCA, a new array of 144 angle-integrating Cherenkov light detectors located at the CASA-MIA site in Utah. CASA data on particle density are used to find the core and direction of air showers, while BLANCA measures the lateral distribution of Cherenkov light about the core. The advantages of Cherenkov light allow BLANCA to measure shower energy with minimal composition bias and to estimate accurately the depth of shower maximum. The cosmic ray flux measured by BLANCA exhibits a knee in the range of 2-3PeV with a width of approximately 0.5 decades in primary energy. The power law indices of the differential flux above and below the knee are -2.72 +/- 0.02 and -2.95 +/- 0.02. The data on mean shower depth indicate that the composition is lighter at 3 PeV than below the knee and that it becomes heavier with increasing energy above 3PeV. Cherenkov measurements are interpreted using the predictions of the CORSIKA Monte Carlo air shower simulation coupled with each of four hadronic interaction codes (QGSJET, VENUS, SIBYLL, and HDPM). The distribution of air shower depths can be reproduced well at all energies by the QGSJET and VENUS models, and these distributions suggest the same composition trends exhibited by the mean depth of maximum results.

  1. Regional Analysis of the Hazard Level of Glacial Lakes in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Chisolm, Rachel E.; Jhon Sanchez Leon, Walter; McKinney, Daene C.; Cochachin Rapre, Alejo

    2016-04-01

    The Cordillera Blanca mountain range is the highest in Peru and contains many of the world's tropical glaciers. This region is severely impacted by climate change causing accelerated glacier retreat. Secondary impacts of climate change on glacier retreat include stress on water resources and the risk of glacial lake outburst floods (GLOFs) from the many lakes that are forming and growing at the base of glaciers. A number of GLOFs originating from lakes in the Cordillera Blanca have occurred over the last century, several of which have had catastrophic impacts on cities and communities downstream. Glaciologists and engineers in Peru have been studying the lakes of the Cordillera Blanca for many years and have identified several lakes that are considered dangerous. However, a systematic analysis of all the lakes in the Cordillera Blanca has never before been attempted. Some methodologies for this type of systematic analysis have been proposed (eg. Emmer and Vilimek 2014; Wang, et al. 2011), but as yet they have only been applied to a few select lakes in the Cordillera Blanca. This study uses remotely sensed data to study all of the lakes of the Glacial Lake Inventory published by the Glaciology and Water Resources Unit of Peru's National Water Authority (UGRH 2011). The objective of this study is to assign a level of potential hazard to each glacial lake in the Cordillera Blanca and to ascertain if any of the lakes beyond those that have already been studied might pose a danger to nearby populations. A number of parameters of analysis, both quantitative and qualitative, have been selected to assess the hazard level of each glacial lake in the Cordillera Blanca using digital elevation models, satellite imagery, and glacier outlines. These parameters are then combined to come up with a preliminary assessment of the hazard level of each lake; the equation weighting each parameter draws on previously published methodologies but is tailored to the regional characteristics

  2. Geologic studies in the Sierra de Pena Blanca, Chihuahua, Mexico

    NASA Astrophysics Data System (ADS)

    Reyes-Cortes, Ignacio Alfonso

    The Sierra del Cuervo has been endowed with uranium mineralization, which has attracted many geological studies, and recently the author was part of a team with the goal of selecting a site of a radioactive waste repository. The first part of the work adds to the regional framework of stratigraphy and tectonics of the area. It includes the idea of a pull apart basin development, which justifies the local great thickness of the Cuervo Formation. It includes the regional structural frame work and the composite stratigraphic column of the Chihuahua Trough and the equivalent Cretaceous Mexican Sea. The general geologic features of the NE part of the Sierra del Cuervo are described, which include the folded ignimbrites and limestones in that area; the irregular large thicknesses of the Cuervo Formation; and the western vergence of the main folding within the area. Sanidine phenocrystals gave ages of 54.2 Ma and 51.8 Ma ± 2.3 Ma. This is the first time these dates have been reported in print. This age indicates a time before the folded structures which outcrop in the area, and 44 Ma is a date after the Cuervo Formation was folded. The Hidalgoan orogeny cycle affected the rocks between this lapse of time. Since then the area has been partially affected by three tensional overlapped stages, which resulted in the actual Basin and Range physiography. The jarosite related to the tectonic activity mineralization has been dated by the Ar-Ar method and yields an age of 9.8 Ma. This is the first report of a date of mineralization timing at Pena Blanca Uranium District in the Sierra del Cuervo. These are some of the frame work features that justify the allocation of a radioactive waste repository in the Sierra del Cuervo. An alluvial fan system within the Boquilla Colorada microbasin was selected as the best target for more detailed site assessment. The study also included the measurement of the alluvium thicknesses by geoelectric soundings; studies of petrography and weathered

  3. REGIONAL HYDROLOGY OF THE NOPAL I SITE, SIERRA DE PENA BLANCA, CHIHUAHUA, MEXICO

    SciTech Connect

    J.A. Rodriguez-Pineda; P. Goodell; P.F. Dobson; J. Walton; R. Oliver; De La Garza; S. Harder

    2005-07-11

    The U.S. Department of Energy sponsored the drilling of three wells in 2003 near the Nopal I uranium deposit at the Sierra Pena Blanca, Chihuahua, Mexico. Piezometric information is being collected to understand groundwater flow at local and regional levels as part of an ongoing natural analogue study of radionuclide migration. Water level monitoring reported at these and other wells in the region is combined with archival data to provide a better understanding of the hydrology at Nopal I. Initial results suggest that the local hydrology is dependent on the regional hydrologic setting and that this groundwater system behaves as an unconfined aquifer. The region is dominated by an alternating sequence of highlands and basins that step down from west to east. The Sierra de Pena Blanca was downdropped from the cratonic block to the west during Cenozoic extension. The Nopal I area is near the intersection of two large listric faults, and the questa of ash flow tuffs that hosts the deposit has been subjected to complex structural events. The Pena Blanca Uranium District was originally characterized by 105 airborne radiometric anomalies, indicating widespread uranium mineralization. The Nopal I uranium deposit is located in the Sierra del Pena Blanca between the Encinillas Basin to the west, with a mean elevation of 1560 m, and the El Cuervo Basin to the east, with a mean elevation of 1230 m. The Nopal I + 10 level is at an intermediate elevation of 1463 m, with a corresponding groundwater elevation of approximately 1240 m. The regional potentiometric surface indicates flow from west to east, with the El Cuervo Basin being the discharge zone for the regional flow system. However, it appears that the local groundwater potential beneath the Nopal I site is more in accordance with the water table of the El Cuervo Basin than with that of the Encinillas Basin. This might indicate that there is limited groundwater flow between the Encinillas Basin and the Nopal I area.

  4. Wind Transport of Radionuclide- Bearing Dust, Peña Blanca, Chihuahua, Mexico

    NASA Astrophysics Data System (ADS)

    Velarde, R.; Goodell, P. C.; Gill, T. E.; Arimoto, R.

    2007-05-01

    This investigation evaluates radionuclide fractionation during wind erosion of high-grade uranium ore storage piles at Peña Blanca (50km north of Chihuahua City), Chihuahua, Mexico. The aridity of the local environment promotes dust resuspension by high winds. Although active operations ceased in 1983, the Peña Blanca mining district is one of Mexico`s most important uranium ore reserves. The study site contains piles of high grade ore, left loose on the surface, and separated by the specific deposits from which they were derived (Margaritas, Nopal I, and Puerto I). Similar locations do not exist in the United States, since uranium mining sites in the USA have been reclaimed. The Peña Blanca site serves as an analog for the Yucca Mountain project. Dust deposition is collected at Peña Blanca with BSNE sediment catchers (Fryrear, 1986) and marble dust traps (Reheis, 1999). These devices capture windblown sediment; subsequently, the sample data will help quantify potentially radioactive short term field sediment loss from the repository surface and determine sediment flux. Aerosols and surface materials will be analyzed and radioactivity levels established utilizing techniques such as gamma spectroscopy. As a result, we will be able to estimate how much radionuclide contaminated dust is being transported or attached geochemically to fine grain soils or minerals (e.g., clays or iron oxides). The high-grade uranium-bearing material is at secular equilibrium, thus the entire decay series is present. Of resulting interest is not only the aeolian transport of uranium, but also of the other daughter products. These studies will improve our understanding of geochemical cycling of radionuclides with respect to sources, transport, and deposition. The results may also have important implications for the geosciences and homeland security, and potential applications to public health. Funding for this project is provided in part via a NSF grant to Arimoto.

  5. Predictive optimal control of sewer networks using CORAL tool: application to Riera Blanca catchment in Barcelona.

    PubMed

    Puig, V; Cembrano, G; Romera, J; Quevedo, J; Aznar, B; Ramón, G; Cabot, J

    2009-01-01

    This paper deals with the global control of the Riera Blanca catchment in the Barcelona sewer network using a predictive optimal control approach. This catchment has been modelled using a conceptual modelling approach based on decomposing the catchments in subcatchments and representing them as virtual tanks. This conceptual modelling approach allows real-time model calibration and control of the sewer network. The global control problem of the Riera Blanca catchment is solved using a optimal/predictive control algorithm. To implement the predictive optimal control of the Riera Blanca catchment, a software tool named CORAL is used. The on-line control is simulated by interfacing CORAL with a high fidelity simulator of sewer networks (MOUSE). CORAL interchanges readings from the limnimeters and gate commands with MOUSE as if it was connected with the real SCADA system. Finally, the global control results obtained using the predictive optimal control are presented and compared against the results obtained using current local control system. The results obtained using the global control are very satisfactory compared to those obtained using the local control. PMID:19700825

  6. Effective utilization of distiller's grain soluble-an agro-industrial waste in the feed of cage-reared minor carp Labeo bata in a tropical reservoir, India.

    PubMed

    Hassan, M A; Aftabuddin, Md; Meena, D K; Mishal, P; Gupta, S Das

    2016-08-01

    A 60-day feeding trial was conducted to evaluate the efficacy of distiller's grain soluble (brewery waste) as a prospective ingredient to substitute expensive and high demand feed component, soybean meal for farming Labeo bata in cages installed in tropical reservoir. Two isonitrogenous and isocaloric diets comprising brewery waste (49.2 % CP) as test diet and soybean meal (44.4 % CP) as reference diet were formulated and extruded to obtain 2-mm floating pellets. The efficacy of the diets was tested in terms of survival (%), live weight gain (%), SGR (%/day), FCR, PER and ANPU and recorded 65 ± 0.2, 96 ± 8.1, 1.9 ± 0.1, 2.5 ± 0.02, 1.4 ± 0.1, 20.3 ± 2.0 and 66 ± 0.6, 112 ± 9.8, 2.2 ± 0.1, 2.2 ± 0.2, 1.6 ± 0.1 and 20 ± 2.1, respectively, for soybean and brewer's waste-based formulated feed. The analyses of results revealed that survival, growth parameters and biochemical composition of whole body tissue did not differ significantly (p > 0.05) despite complete replacement of soybean meal by brewery waste. However, the cost estimate of diet revealed marked reduction of feed cost of Rs. 9.2/kg (33.8 %) in the test diet as compared to the reference diet. The study suggests that brewery waste could effectively replace soybean meal without effecting survival and growth of the fish. The finding thus may pave a productive way for reducing environmental pressure of disposal of an agro-industrial waste. PMID:27146546

  7. Slab flattening driving regional uplift in the Cordilleras Blanca and Negra, Western Andes

    NASA Astrophysics Data System (ADS)

    Margirier, Audrey; Audin, Laurence; Robert, Xavier; Bernet, Matthias; Gautheron, Cécile

    2015-04-01

    The Andean range topographic evolution is known to have had a strong impact on regional climate by building an orographic barrier that preserved its western flank from the south Atlantic moisture. Even if largely invoked, the impact of subduction processes on the uplift and relief building is not yet well understood in the Andes. The northern Peru is characterized by a present day flat subduction zone (3-15°S), where both the geometry and temporal evolution of the flat-slab are well constrained. The subduction of two buoyant anomalies, the Nazca ridge and the lost Inca plateau controlled the slab flattening. The highest Peruvian peaks in the Cordillera Blanca (6768 m), and the Cordillera Negra (5187 m) are located just above the flat-slab segment. Both ranges trend parallel to the subduction zone and are separated by the NW-SE Rio Santa valley. The Cordillera Blanca batholith emplaced at 8-5 Ma and renders of an abnormal magmatic activity over a planar subduction. This area is a perfect target to explore the impact of slab flattening on the topography and uplift in the Occidental Cordillera of the Andes. We present new AHe and AFT data from three vertical profiles located in both the Cordilleras Blanca and Negra. We compare time-temperature paths obtained from inverse modeling of the thermochronological data with the timing of the slab flattening, the arrival of the Nazca ridge and magmatism. Our thermochronological data evidences a regional exhumation in the Occidental Cordillera from ~10 Ma. We propose that the Nazca ridge subduction below the Occidental Cordillera (11 Ma) and slab flattening (8 Ma) drive the Occidental Cordillera uplift and thus exhumation. We evidence the important contribution of the magmatism in the Cordillera Blanca exhumation and high relief building in the Occidental Cordillera. Our new thermochronological data highlight the control of both the subduction processes and magmatism on the paleogeography and uplift in the Andes. Finally, the

  8. Slab flattening, dynamic topography and normal faulting in the Cordillera Blanca region (northern Peru)

    NASA Astrophysics Data System (ADS)

    Margirier, A.; Robert, X.; Laurence, A.; Gautheron, C.; Bernet, M.; Simon-Labric, T.; Hall, S. R.

    2015-12-01

    Processes driving surface uplift in the Andes are still debated and the role of subduction processes as slab flattening on surface uplift and relief building in the Andes is not well understood. Some of the highest Andean summits, the Cordillera Blanca (6768 m) and the Cordillera Negra (5187 m), are located above a present flat subduction zone (3-15°S), in northern Peru. In this area, both the geometry and timing of the flattening of the slab are well constrained (Gutscher et al., 1999; Rosenbaum et al., 2005). This region is thus a perfect target to explore the effect of slab flattening on the Andean topography and uplift. We obtained new apatite (U-Th)/He and fission-track ages from three vertical profiles located in the Cordillera Blanca and the Cordillera Negra. Time-temperature paths obtained from inverse modeling of the thermochronological data indicates a Middle Miocene cooling for both Cordillera Negra profiles. We interpret it as regional exhumation in the Cordillera Occidental starting in Middle Miocene, synchronous with the onset of the subduction of the Nazca ridge (Rosenbaum et al., 2005). We propose that the Nazca ridge subduction at 15 Ma and onset of slab flattening in northern Peru drove regional positive dynamic topography and thus enhanced exhumation in the Cordillera Occidental. This study provides new evidence of the impact subduction processes and associated dynamic topography on paleogeography and surface uplift in the Andes.

  9. Major QTLs control resistance to rice hoja blanca virus and its vector Tagosodes orizicolus.

    PubMed

    Romero, Luz E; Lozano, Ivan; Garavito, Andrea; Carabali, Silvio J; Triana, Monica; Villareal, Natalia; Reyes, Luis; Duque, Myriam C; Martinez, César P; Calvert, Lee; Lorieux, Mathias

    2014-01-01

    Rice hoja blanca (white leaf) disease can cause severe yield losses in rice in the Americas. The disease is caused by the rice hoja blanca virus (RHBV), which is transmitted by the planthopper vector Tagosodes orizicolus. Because classical breeding schemes for this disease rely on expensive, time-consuming screenings, there is a need for alternatives such as marker-aided selection. The varieties Fedearroz 2000 and Fedearroz 50, which are resistant to RHBV and to the feeding damage caused by T. orizicolus, were crossed with the susceptible line WC366 to produce segregating F2:3 populations. The F3 families were scored for their resistance level to RHBV and T. orizicolus. The F2:3 lines of both crosses were genotyped using microsatellite markers. One major QTL on the short arm of chromosome 4 was identified for resistance to RHBV in the two populations. Two major QTL on chromosomes 5 and 7 were identified for resistance to T. orizicolus in the Fd2000 × WC366 and Fd50 × WC366 crosses, respectively. This comparative study using two distinct rice populations allowed for a better understanding of how the resistance to RHBV and its vector are controlled genetically. Simple marker-aided breeding schemes based on QTL information can be designed to improve rice germplasm to reduce losses caused by this important disease. PMID:24240781

  10. Major QTLs Control Resistance to Rice Hoja Blanca Virus and Its Vector Tagosodes orizicolus

    PubMed Central

    Romero, Luz E.; Lozano, Ivan; Garavito, Andrea; Carabali, Silvio J.; Triana, Monica; Villareal, Natalia; Reyes, Luis; Duque, Myriam C.; Martinez, César P.; Calvert, Lee; Lorieux, Mathias

    2013-01-01

    Rice hoja blanca (white leaf) disease can cause severe yield losses in rice in the Americas. The disease is caused by the rice hoja blanca virus (RHBV), which is transmitted by the planthopper vector Tagosodes orizicolus. Because classical breeding schemes for this disease rely on expensive, time-consuming screenings, there is a need for alternatives such as marker-aided selection. The varieties Fedearroz 2000 and Fedearroz 50, which are resistant to RHBV and to the feeding damage caused by T. orizicolus, were crossed with the susceptible line WC366 to produce segregating F2:3 populations. The F3 families were scored for their resistance level to RHBV and T. orizicolus. The F2:3 lines of both crosses were genotyped using microsatellite markers. One major QTL on the short arm of chromosome 4 was identified for resistance to RHBV in the two populations. Two major QTL on chromosomes 5 and 7 were identified for resistance to T. orizicolus in the Fd2000 × WC366 and Fd50 × WC366 crosses, respectively. This comparative study using two distinct rice populations allowed for a better understanding of how the resistance to RHBV and its vector are controlled genetically. Simple marker-aided breeding schemes based on QTL information can be designed to improve rice germplasm to reduce losses caused by this important disease. PMID:24240781

  11. U-Series Transport Studies at the Pena Blanca, Mexico Natural Analog Site

    SciTech Connect

    A. M. Simmons; M. T. Murrell

    2001-05-31

    Natural analogs provide a line of evidence that supports the understanding of how natural and engineered processes would occur over long time frames and large spatial scales at a potential nuclear waste repository at Yucca Mountain, Nevada. Studies of U-series disequilibria within and around uranium deposits can provide valuable information on the timing of actinide mobility and hence the stability of a potential repository over geologic time scales. The Nopal I uranium deposit at Pena Blanca, Mexico, is situated in unsaturated tuff that is similar in composition to the Topopah Spring Tuff of Yucca Mountain and closely matches other evaluation criteria for suitable natural analogs. By modeling the observed radioactive isotope disequilibria at Nopal I, we can estimate the rates of sorption-desorption and dissolution-precipitation of the radionuclides over time. Such information is vital to the testing or validation of performance assessment models for geologic nuclear waste disposal.

  12. Paleoseismicity and neotectonics of the Cordillera Blanca fault zone, Northern Peruvian Andes.

    USGS Publications Warehouse

    Schwartz, D.P.

    1988-01-01

    The Cordillera Blanca fault zone is a major W dipping normal fault that bounds the W side of a 120- 170-km wide zone of active extension along the crest of the N Peruvian Andes. The fault is approximately 210 km long and exhibits continuous geomorphic evidence of repeated late Pleistocene and Holocene displacements but has not been the source of historical or teleseismically recorded earthquakes. Trenching and mapping of fault scarps provide new information on earthquake recurrence, slip rate, timing of the most recent events and Andean neotectonics. At Quebrada Queroccocha, 55 km from valley fill lacustrine and fluvial deposits are displaced 7.5-8 m. Scarp profiles, tectonic terraces, and trench exposures indicate 5 to 7 scarp-forming earthquakes of 2-3 m per event during the past 11 000-14 000 yrs at this location.-from Author

  13. Dust from Anthropogenic Sources in the Snowpack on Glaciers in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Semborski, R. J.

    2013-12-01

    The tropical glaciers in the high mountains of Peru are currently experiencing rapid melting due to climate change and to increased human activities. The objective of my research project is to quantify the impact of deposited airborne particulates including dust on the spectral albedo of the glacial snowpack in the Cordillera Blanca located in Huascaran National Park, Ancash Region of Peru. Snow and ice samples collected from several peaks throughout the range will be melted and filtered through 25 mm quartz filters (Pallflex Tissuquartz, 0.7 micron pore size). The filters will be analyzed using two methods: Optical and Thermal. Collected spectral albedo measurements will be used to help quantify the results. The results will help determine spatial variability, and therefore potential sources and quantitative impact on snowpack albedo and glacial melting.

  14. Sources and pathways of stream generation in tropical proglacial valleys of the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Gordon, Ryan P.; Lautz, Laura K.; McKenzie, Jeffrey M.; Mark, Bryan G.; Chavez, Daniel; Baraer, Michel

    2015-03-01

    Tropical glaciers supply approximately half of dry-season stream discharge in glacierized valleys of the Cordillera Blanca, Peru. The remainder of streamflow originates as groundwater stored in alpine meadows and other proglacial geomorphic features. A better understanding of the hydrogeology of alpine groundwater, including sources, storage zones, and the locations and magnitudes of contributions to streamflow, is important for making accurate estimates of glacial inputs to the hydrologic budget, and for our ability to make predictions about future water resources as glaciers retreat. This field study focuses on two high-elevation meadows in valleys of the Cordillera Blanca, in headwaters and mid-valley locations. Tracer measurements of stream and spring discharge and groundwater-surface water exchange were combined with synoptic sampling of water isotopic and geochemical composition in order to characterize and quantify contributions to streamflow from different groundwater reservoirs. At the headwaters site, groundwater supplied approximately half of stream discharge from a small meadow, with most originating in an alluvial fan adjacent to the meadow and little (6%) from the meadow itself; however, at the mid-valley site, where meadows are extensive, local groundwater has a large impact on streamflow and chemistry through large net contributions to discharge and turnover of surface water due to gross exchanges with groundwater. At the mid-valley site, stream discharge increased by 200 L s-1 (18% of average discharge) over 1.2 km as it descended a moraine between two meadows. Such valley-crossing moraines, which create significant steps in the down-valley slope, are likely locations of substantial groundwater contribution to streams.

  15. Spatial distribution of canine zoonotic enteroparasites in Bahía Blanca, Argentina.

    PubMed

    La Sala, Luciano F; Leiboff, Anastasia; Burgos, Julián M; Costamagna, Sixto R

    2015-01-01

    The objectives of this research were: (1) to determine the occurrence of zoonotic enteroparasites in dog feces from Bahía Blanca, Argentina; (2) to characterize the spatial distribution of the parasites found in association with the quality of life index (QLI) in neighborhoods of Bahía Blanca; and (3) to determine if the presence of a particular parasite genus in a stool sample was facilitated or impeded by the presence of other parasite genera. Samples of dog stools (n=475) were collected between December 2012 and December 2013 in areas with varying QLI. The association between QLI values and the presence of parasites was analyzed using logistic regression. Overall enteroparasite occurrence was 36.6%. Parasitic forms found included nematode larvae, cysts of Blastocystis spp., Giardia spp., and oocysts of Cryptosporidium spp., and eggs of Ancylostoma caninum, Toxocara canis, cestodes and Trichuris spp. For certain enteroparasites, we detected significant associations between their occurrence and QLI. Feces collected in areas with medium and low QLI were 2.46 and 5.43 times more likely, respectively, to contain A. caninum than stools from the high-QLI area. Samples from areas with low QLI were 2.36 times more likely to contain Trichuris spp. than those from the high QLI area. Regarding protozoa, feces from areas with low QLI were 2.4 times more likely to be positive than those from areas with high QLI. We demonstrated that canine zoonotic parasites have a wide distribution in the study area, and that occurrence is higher in neighborhoods with lower QLI. PMID:25705047

  16. Single layer centrifugation (SLC) improves sperm quality of cryopreserved Blanca-Celtibérica buck semen.

    PubMed

    Jiménez-Rabadán, P; Morrell, J M; Johannisson, A; Ramón, M; García-Álvarez, O; Maroto-Morales, A; Alvaro-García, P J; Pérez-Guzmán, M D; Fernández-Santos, M R; Garde, J J; Soler, A J

    2012-12-01

    The aim of the present study was to evaluate the effect of sperm selection by means of single layer centrifugation (SLC) on sperm quality after cryopreservation, either when SLC is used before freezing or after thawing, using Blanca-Celtibérica buck semen collected by electroejaculation (EE). Ejaculates from six bucks were collected by EE and divided into two aliquots. One of them (unselected) was diluted with Biladyl(®) by the two-step method and frozen over nitrogen vapor. The other aliquot was selected by the SLC technique and subsequently frozen in the same way as the unselected samples (SLC before freezing). In a further treatment, two unselected straws were thawed and SLC was carried out (SLC after thawing). At thawing, sperm motility of all samples ((i) unselected; (ii) selected before freezing and (iii) selected after thawing) was evaluated by CASA. In addition, integrity of the plasma membrane, mitochondrial membrane potential, ROS production and DNA fragmentation index were assessed by flow cytometry. Most of the sperm parameters were improved (P≤0.001) in samples selected by SLC after thawing in relation to unselected or selected by SLC before freezing. The percentage of progressive motile spermatozoa was greater (86%) for sperm samples selected after thawing compared with unselected (58%) or selected before freezing (54%). Moreover, percentages of spermatozoa with intact plasma membrane and spermatozoa with high mitochondrial membrane potential (hMMP) were also greater for sperm samples selected after thawing compared to sperm samples unselected or selected before freezing (spermatozoa with intact plasma membrane: 80% vs. 32% vs. 12%; spermatozoa with hMMP: 54% vs. 1% vs. 15%; respectively). Therefore, sperm quality after cryopreservation is improved in Blanca-Celtibérica buck ejaculates collected by EE when a sperm selection technique such as SLC is carried out after thawing. PMID:23084569

  17. Measurements of light-absorbing particles on the glaciers in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Schmitt, C. G.; All, J. D.; Schwarz, J. P.; Arnott, W. P.; Cole, R. J.; Lapham, E.; Celestian, A.

    2015-02-01

    Glaciers in the tropical Andes have been rapidly losing mass since the 1970s. In addition to the documented increase in temperature, increases in light-absorbing particles deposited on glaciers could be contributing to the observed glacier loss. Here we report on measurements of light-absorbing particles sampled from glaciers during three surveys in the Cordillera Blanca Mountains in Peru. During three research expeditions in the dry seasons (May-August) of 2011, 2012 and 2013, 240 snow samples were collected from 15 mountain peaks over altitudes ranging from 4800 to nearly 6800 m. Several mountains were sampled each of the 3 years and some mountains were sampled multiple times during the same year. Collected snow samples were melted and filtered in the field then later analyzed using the Light Absorption Heating Method (LAHM), a new technique that measures the ability of particles on filters to absorb visible light. LAHM results have been calibrated using filters with known amounts of fullerene soot, a common industrial surrogate for black carbon (BC). As sample filters often contain dust in addition to BC, results are presented in terms of effective black carbon (eBC). During the 2013 survey, snow samples were collected and kept frozen for analysis with a Single Particle Soot Photometer (SP2). Calculated eBC mass from the LAHM analysis and the SP2 refractory black carbon (rBC) results were well correlated (r2 = 0.92). These results indicate that a substantial portion of the light-absorbing particles in the more polluted regions were likely BC. The 3 years of data show that glaciers in the Cordillera Blanca Mountains close to human population centers have substantially higher levels of eBC (as high as 70 ng g-1) than remote glaciers (as low as 2.0 ng g-1 eBC), indicating that population centers can influence local glaciers by sourcing BC.

  18. Measurements of light absorbing particulates on the glaciers in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Schmitt, C. G.; All, J. D.; Schwarz, J. P.; Arnott, W. P.; Cole, R. J.; Lapham, E.; Celestian, A.

    2014-10-01

    Glaciers in the tropical Andes have been rapidly losing mass since the 1970s. In addition to the documented increase in air temperature, increases in light absorbing particulates deposited on glaciers could be contributing to the observed glacier loss. Here we report on measurements of light absorbing particulates sampled from glaciers during three surveys in the Cordillera Blanca in Peru. During three research expeditions in the dry seasons (May-August) of 2011, 2012 and 2013, two hundred and forty snow samples were collected from fifteen mountain peaks over altitudes ranging from 4800 to nearly 6800 m. Several mountains were sampled each of the three expeditions and some mountains were sampled multiple times during the same expedition. Collected snow samples were melted and filtered in the field then later analyzed using the Light Absorption Heating Method (LAHM), a new technique that measures the ability of particulates on filters to absorb visible light. LAHM results have been calibrated using filters with known amounts of fullerene soot, a common industrial surrogate for black carbon (BC). As sample filters often contain dust in addition to BC, results are presented in terms of effective Black Carbon (eBC). During the 2013 survey, snow samples were collected and kept frozen for analysis with a Single Particle Soot Photometer (SP2). Calculated eBC mass from the filter analysis and the SP2 refractory Black Carbon (rBC) results were well correlated (r2 = 0.92). These results indicate that a substantial portion of the light absorbing particulates in the more polluted areas were likely BC. The three years of data show that glaciers in the Cordillera Blanca Mountains close to human population centers have substantially higher levels of eBC (as high as 70 ng g-1) than remote glaciers (as low as 2.0 ng g-1 eBC), indicating that population centers can influence local glaciers by sourcing BC.

  19. Asymmetrical Growth of Footwall Topography in the Cordillera Blanca, Peru: Implications for Normal Fault Control on Landscape Evolution

    NASA Astrophysics Data System (ADS)

    Giovanni, M. K.; Horton, B. K.

    2007-12-01

    Morphometric parameters and hypsometry of the >5-km-high Cordillera Blanca in Peru provide insights into the topographic evolution of the uplifted footwall of an active, high-magnitude-slip, low-angle normal fault within a contractional orogenic belt. The modern tectonic activity, mappable fault trace, high relief, and uniform footwall lithology make the Cordillera Blanca an ideal locality to test models for the evolution of topography related to normal faulting. Most models for normal fault growth suggest a tectonic and geomorphic symmetry in which maximum slip and maximum surface uplift occur along the central segments of the fault, with net slip, footwall uplift, and hangingwall subsidence diminishing along strike toward the fault tips. A digital elevation model (DEM) of the Cordillera Blanca permits extraction of important geomorphic metrics for footwall transverse drainages and the hanging-wall axial river, including hypsometry, drainage area, drainage length, relief, channel gradient, surface slope, aspect ratio, and longitudinal profile. These data reveal a pronounced asymmetry in which footwall relief, exposed fault relief, channel gradient, and surface slope are greatest along the northern fault segment and become systematically lower southward along strike. In contrast to most models for normal fault growth, largely based on late Cenozoic systems in the Basin and Range province of the western United States, the Cordillera Blanca demonstrates that abrupt and significant along-strike variations in displacement and footwall uplift are possible in major normal fault systems. The causes of an asymmetric distribution of fault slip and footwall topography in the Cordillera Blanca may be related to: (a) mechanical coupling between the subducting flat Nazca slab and the overriding South American plate; (b) gravitational collapse of overthickened crust along reactivated thrust faults; (c) climatic processes linked to the effect of glacial erosion in the footwall

  20. Recent (0-8 Ma) tectonics and exhumation processes in Cordilleras Blanca and Negra, Central Peru: Constraints from (U-Th)/He dating

    NASA Astrophysics Data System (ADS)

    Margirier, Audrey; Robert, Xavier; Gautheron, Cécile; Audin, Laurence

    2014-05-01

    The Central Andes are a classical example of topography building in front of an oceanic subduction. However, many first order questions are still debated: How do subduction processes and observed tectonic uplift interact along the Andean margin? What is the impact of tectonic, magmatism and climate on exhumation? The Cordilleras Blanca (6768 m) and Negra (5181 m), in north Central Peru, belong to the highest Andean reliefs. Both ranges trend parallel to the subduction zone and are separated by the NW-SE Rio Santa valley. The Cordillera Blanca pluton formed in an active subduction context at 8-5 Ma and renders an abnormal magmatic activity over a planar subduction. In contrast with the Cordillera Blanca, the Cordillera Negra is an older relief, which evolution and exhumation history has never been studied. A remarkable ~200 km-long normal fault system showing ~4500 m of vertical displacement since 5 Ma edges the western flank of the Cordillera Blanca. This region is a perfect target to study the impact of magmatism and subduction processes on exhumation. We perform a morphotectonic study on both cordilleras coupled with low-temperature thermochronology apatite (U-Th)/He dating to quantify these processes. Geomorphic parameters and altitude contrasts between these two ranges indicate a differential uplift. The Cordillera Negra displays a smooth and asymmetric relief from the West to the East whereas the Cordillera Blanca shows higher and sharper relief with North/South and East/West contrasts. We obtain apatite (U-Th)/He ages for twenty samples located along vertical and horizontal profiles at different latitudes of the Cordilleras Blanca and Negra. The (U-Th)/He ages range from 13.4 ± 1.3 to 5.6 ± 0.6 Ma in the Cordillera Negra and range from 11.8 ± 1.2 to 2.0 ± 0.2 Ma in the Cordillera Blanca. We use them as inputs in QTQt tools for time-temperature reconstructions and thus to constrain the exhumation history. Whole ages evidence a more regional exhumation than

  1. Prevalence of Pediculus humanus capitis infestation among kindergarten children in Bahía Blanca city, Argentina.

    PubMed

    Gutiérrez, María Mercedes; González, Jorge Werdin; Stefanazzi, Natalia; Serralunga, Gabriela; Yañez, Loreto; Ferrero, Adriana Alicia

    2012-09-01

    The human head louse, Pediculus humanus capitis De Geer (Anoplura: Pediculidae), is a worldwide public health concern. This human obligate ectoparasite usually infests school age children. The aim of this work was to investigate the prevalence of head lice in kindergarten children from Bahia Blanca. In addition, the influence of risk factors for pediculosis infestation, such as gender, hair characteristics, and socioeconomic class, was studied in relation to the prevalence of this ectoparasite. From a total of 220 pupils examined (125 girls and 95 boys), 94 showed pediculosis. The overall prevalence of head lice infestation was 42.7 %. Pediculosis was more frequent in girls (53.6 %) than in boys (28.4 %) and in medium, long, and very long hairs. No differences were found between socioeconomic classes. This indicated that head lice are relatively common in kindergarten children from Bahía Blanca. PMID:22752696

  2. Remote Sensing Analysis of the Sierra Blanca (Faskin Ranch) Low-Level Radioactive Waste Disposal Site, Hudspeth County, Texas

    SciTech Connect

    LeMone, D. V.; Dodge, R.; Xie, H.; Langford, R. P.; Keller, G. R.

    2002-02-26

    Remote sensing images provide useful physical information, revealing such features as geological structure, vegetation, drainage patterns, and variations in consolidated and unconsolidated lithologies. That technology has been applied to the failed Sierra Blanca (Faskin Ranch) shallow burial low-level radioactive waste disposal site selected by the Texas Low-Level Radioactive Waste Disposal Authority. It has been re-examined using data from LANDSAT satellite series. The comparison of the earlier LANDSAT V (5/20/86) (30-m resolution) with the later new, higher resolution ETM imagery (10/23/99) LANDSAT VII data (15-m resolution) clearly shows the superiority of the LANDSAT VII data. The search for surficial indications of evidence of fatal flaws at the Sierra Blanca site utilizing was not successful, as it had been in the case of the earlier remote sensing analysis of the failed Fort Hancock site utilizing LANDSAT V data. The authors conclude that the tectonic activity at the Sierra Blanca site is much less recent and active than in the previously studied Fort Hancock site. The Sierra Blanca site failed primarily on the further needed documentation concerning a subsurface fault underneath the site and environmental justice issues. The presence of this fault was not revealed using the newer LANDSAT VII data. Despite this fact, it must be remembered that remote sensing provides baseline documentation for determining future physical and financial remediation responsibilities. On the basis of the two sites examined by LANDSAT remote sensing imaging, it is concluded that it is an essential, cost-effective tool that should be utilized not only in site examination but also in all nuclear-related facilities.

  3. New geologic slip rates for the Agua Blanca Fault, northern Baja California, Mexico

    NASA Astrophysics Data System (ADS)

    Gold, P. O.; Behr, W. M.; Fletcher, J. M.; Hinojosa-Corona, A.; Rockwell, T. K.

    2015-12-01

    Within the southern San Andreas transform plate boundary system, relatively little is known regarding active faulting in northern Baja California, Mexico, or offshore along the Inner Continental Borderland. The inner offshore system appears to be fed from the south by the Agua Blanca Fault (ABF), which strikes northwest across the Peninsular Ranges of northern Baja California. Therefore, the geologic slip rate for the ABF also provides a minimum slip rate estimate for the offshore system, which is connected to the north to faults in the Los Angeles region. Previous studies along the ABF determined slip rates of ~4-6 mm/yr (~10% of relative plate motion). However, these rates relied on imprecise age estimates and offset geomorphic features of a type that require these rates to be interpreted as minima, allowing for the possibility that the slip rate for the ABF may be greater. Although seismically quiescent, the surface trace of the ABF clearly reflects Holocene activity, and given its connectivity with the offshore fault system, more quantitative slip rates for the ABF are needed to better understand earthquake hazard for both US and Mexican coastal populations. Using newly acquired airborne LiDAR, we have mapped primary and secondary fault strands along the segmented western 70 km of the ABF. Minimal development has left the geomorphic record of surface slip remarkably well preserved, and we have identified abundant evidence meter to km scale right-lateral displacement, including new Late Quaternary slip rate sites. We verified potential reconstructions at each site during summer 2015 fieldwork, and selected an initial group of three high potential slip rate sites for detailed mapping and geochronologic analyses. Offset landforms, including fluvial terrace risers, alluvial fans, and incised channel fill deposits, record displacements of ~5-80 m, and based on minimal soil development, none appear older than early Holocene. To quantitatively constrain landform ages

  4. Past peak water in Peru's Cordillera Blanca: diagnosing the demise of glacier influence on stream discharge

    NASA Astrophysics Data System (ADS)

    Baraer, M.; Mark, B. G.; McKenzie, J. M.

    2011-12-01

    In conditions of continuous retreat, glaciers generate a temporary increase in stream runoff as they lose mass. Yet as the extant glacier volume diminishes, the annual runoff reaches a peak and is followed by a persistent decrease. In the present study we explore historical and modern discharge measurements measured between 1952 and 2010 at nine stations across the upper Rio Santa watershed, the basin that drains most of the western Cordillera Blanca, Peru, and situate the regional stream hydrology within this glacier influence change sequence. The relation between glacial retreat and stream discharge is investigated by the use of a simple water balance model that simulates glacier retreat influence on the annual and dry-season discharge, as well as on the annual discharge variability, permitting distinction between four phases of glacier retreat hydrological impact. The link between the modeled synthetic time series and the Cordillera Blanca discharge records is assessed using polynomial regressions and the Mann-Kendall non-parametric statistical test on daily discharge series for three hydrograph parameters: the yearly average, the dry season discharge and the variability coefficient. The glacial retreat for the same period is estimated using existing historical data of glacial coverage from an analysis of composite ASTER imagery that shows accelerating glacier recession in the upper Rio Santa watershed, with the overall glacierized area decreasing annually by 0.81 % between 1990 and 2009. The results provide statistically significant evidence that seven of the nine discharge time series have crossed a critical transition, and now exhibit a decreasing trend related to glacier retreat. La Balsa station measures discharge from the entire upper Rio Santa before entering a major hydro-electrical power plant, and it is undergoing a decline in dry season flow that probably began during the 1970s. Our results predict that if the glaciers completely melt, stream

  5. Uranium-series dating of actinide decay series mobility at Pena Blanca

    SciTech Connect

    Dixon, P.R.; Goldstein, S.J.; Murrell, M.T.

    1997-12-31

    Studies of U-series disequilibria near uranium ore deposits can provide valuable information on the mobility of actinides and their daughters over the range of timescales needed to assess the stability of proposed waste repositories. We have applied highly sensitive TIMS methods to obtain 238U-234U-230Th dates for three whole rock samples within a {approximately}30 in long fracture emanating into surrounding tuff from the deposit at Pena Blanca, Mexico. The 238U-234U-230Th data lie on a whole-rock isochron that requires closed-system behavior for the last 380 ka. Preliminary 231Pa-235U data for the U-rich vein also indicates closed system behavior for at least the last 100 ka. In contrast, 226Ra/230Th activity ratios range from 0.76-0.99 which indicates more recent Ra mobility within the fracture most likely due to surface water infiltration. Our results require uranium, thorium and protactinium stability despite recent radium mobility and provide important constraints on repository stability over {approximately}100 ka timescales.

  6. Morphology and dynamics of large subtidal dunes in Bahia Blanca estuary, Argentina

    NASA Astrophysics Data System (ADS)

    Minor Salvatierra, Marta; Aliotta, Salvador; Ginsberg, Silvia Susana

    2015-10-01

    The purpose of this paper is to carry out a detailed analysis of subtidal dune morphology and temporal variability and to estimate dune migration rate to improve knowledge of this topic, and so enhance the existing data on different marine environments in the world and especially in South America where this information is limited. Two swath bathymetry surveys were conducted across a dune field in the Bahia Blanca Estuary (Argentina). Morphometric parameters and migration rate according to the dune type, were analyzed. The field is composed of large dunes exhibiting two morphological configurations, which are differentiated into sinuous and barchan dunes. The dunes studied are the largest of the estuary, with heights and wavelengths greater than 5 m and 130 m, respectively. The crests of the large dunes are arranged with an orientation perpendicular to the axis of the channel. From geometrical analysis of the parameters, the dunes show a weakly positive correlation between dune height and wavelength as too between dune height and water depth. No clear relationship was observed between maximum height and wavelength parameters with water depth. Across the estuary, the bedforms migrate in the ebb direction, with mean rate of 43 m year- 1. Comparison of our results with previous data shows that during three decades the western boundary of dune field has been displaced 900 m towards the outer estuary, however the dune field configuration and distribution of diverse types of bedform appear to be relatively stable.

  7. Slope deformations in high-mountain regions as observed by InSAR: Examples from the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Frey, Holger; Strozzi, Tazio; Caduff, Rafael; Huggel, Christian; Klimeš, Jan; Vilímek, Vít; Wiesmann, Andreas; Kääb, Andreas; Cochachin, Alejo; Plummer, Stephen

    2016-04-01

    Steep topography, the world's highest concentration of tropical glaciers, numerous glacial lakes and strong seismic activity combined with a densely populated valley bottom in the Rio Santa basin characterize the Cordillera Blanca in Peru. Besides glacier-related processes, a variety of landslide types and processes is present outside the glaciated areas, favoured by the steep terrain, geological conditions, sparse vegetation, intense precipitation, and strong seismicity. This combination of high hazard potentials and vulnerabilities results in a long list of natural disasters. Information on surface displacements is very valuable for early detection of emerging hazard potentials and their assessment. Interferometric processing of SAR data (InSAR) provides the possibility to remotely detect different types of surface displacement processes, also in remote locations where no other monitoring data are available. This contribution, developed under the ESA-funded S:GLA:MO project (sglamo.gamma-rs.ch), shows the potential of InSAR products for hazard assessments and glaciological investigations in high-mountain regions. We present a selection of different surface displacements as observed in the Cordillera Blanca based on InSAR data: a landslide zone near the Rampac Grande village, where in 2009 a landslide caused casualties and property loss; a landslide at the entry of the Santa Cruz Valley, northern Cordillera Blanca, where the displacement history could be reconstructed over five years; surface displacements at the interior moraine slopes surrounding Laguna Palcacocha, a major glacier lake above the city of Huaraz, which are compared to and complemented by geophysical investigations in the field; surface displacements at the moraine damming Laguna Safuna Alta, a glacier lake in the northern part of the Cordillera Blanca; glacier velocities across the entire Cordillera Blanca, revealing ice flow velocities of more than 200 m yr-1 at certain locations at the end of

  8. Constraining Subsurface Structure and Composition Using Seismic Refraction Surveys of Proglacial Valleys in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Glas, R. L.; Lautz, L.; McKenzie, J. M.; Mark, B. G.; Baker, E. A.; Aubry-Wake, C.; Somers, L. D.; Wigmore, O.

    2015-12-01

    As tropical glaciers rapidly recede in response to climate change, the storage and discharge of groundwater will play an increasing role in regulating river baseflow, particularly during the dry season, when stream flow is currently sustained predominantly by glacial melt. Little is understood regarding the hydrogeologic processes controlling base flow characteristics of low-gradient proglacial valleys of the Cordillera Blanca in Northwestern Peru, which has the world's highest density of tropical glaciers. To better understand the processes of groundwater storage and discharge in proglacial meadows, we completed seismic refraction surveys in three representative valleys of the Cordillera Blanca range: the Quilcayhuanca, Yanamarey, and Pachacoto valleys. The locations of survey transects were chosen based on locations of previous sediment core sampling, GPR lines, and quantification of groundwater-surface water interaction derived from dye and temperature tracing experiments. The seismic surveys consisted of 48 vertical component geophones with 2.5 m spacing. Across the three representative valleys a total of 15 surveys were conducted, covering a distance of 1800 m in cross, down, and oblique-valley directions. Preliminary interpretation of the seismic refraction data indicates a maximum imaging depth of 16 m below land surface, and a transition from glacio-lacustrine sediments to buried saturated talus at a depth of 6 m in the Quilcayhuanca valley. The organic-rich glacio-lacustrine sediments in the Yanamarey valley have seismic velocities ranging from 300 to 800 m/s and are >16 m in thickness at mid- valley. Weathered metasedimentary bedrock in the Pachacoto valley was imaged at ~5 m below the valley surface, exhibiting a p-wave velocity of 3400 m/s. The knowledge of hydrogeologic structure derived from seismic refraction surveys will provide crucial boundary conditions for future groundwater models of the valleys of the Cordillera Blanca.

  9. Reinterpretation of the formation of the "crooked moraine" of the debris-covered Hatunraju Glacier (Cordillera Blanca, Perú)

    NASA Astrophysics Data System (ADS)

    Iturrizaga, L.

    2012-04-01

    The Hatunraju Glacier (9°00'S/70°40'W) is located in the Parón valley in the northern part of the Cordillera Blanca. The almost 4 km long and steeply inclined glacier flows down from the Huandoy-N-Side (6395 m) into the Parón valley to an elevation of 4250 m a.s.l.. The extremely narrow glacier is in its entire ablation area heavily debris-covered. It is one of the few glaciers, which dam with its debris-mantled glacier tongue a main river in this mountain range. In this case the Hatunraju glacier produces the largest glacier-dammed lake in the Cordillera Blanca, the Laguna Parón. In some other aspects, this glacier proves to be distinct from the majority of the glaciers in the Cordillera Blanca: It is flowing on an almost up to 250 m high moraine pedestal ("moraine-dammed raised bed glacier") and the glacier makes a bend of almost 90° when entering into the main valley. The present paper focuses in particular on the last point: the formation of the so called "crooked moraine". It has been explained by Lliboutry (1977) as a result of a glacier lake outburst and the subsequent destruction of the latero-frontal moraine. The later process supposed to be the trigger of the abrupt change in the flow direction of the lower part of the glacier. Recent investigations suggest an alternative genesis of the crooked moraine considering the distinct phases of the glaciation history of the Parón valley. The here proposed formation pattern is also paradigmatic for other crooked debris-covered glaciers, especially in High Asia. Comparative examples will be provided from the Karakoram and Himalayas. The research work on the Hatunraju Glacier is part of a project on the glacial geomorphology in the Tropical Andes financed by the Alexander von Humboldt-Foundation.

  10. Epithermal uranium deposits in a volcanogenic context: the example of Nopal 1 deposit, Sierra de Pena Blanca, Mexico

    NASA Astrophysics Data System (ADS)

    Calas, G.; Angiboust, S.; Fayek, M.; Camacho, A.; Allard, T.; Agrinier, P.

    2009-12-01

    The Peña Blanca molybdenum-uranium field (Chihuahua, Mexico) exhibits over 100 airborne anomalies hosted in tertiary ignimbritic ash-flow tuffs (44 Ma) overlying the Pozos conglomerate and a sequence of Cretaceous carbonate rocks. Uranium occurrences are associated with breccia zones at the intersection of two or more fault systems. Periodic reactivation of these structures associated with Basin and Range and Rio Grande tectonic events resulted in the mobilization of U and other elements by meteoric fluids heated by geothermal activity. Trace element geochemistry (U, Th, REE) provides evidence for local mobilization of uranium under oxidizing conditions. In addition, O- and H-isotope geochemistry of kaolinite, smectite, opal and calcite suggests that argillic alteration proceeded at shallow depth with meteoric water at 25-75 °C. Focussed along breccia zones, fluids precipitated several generations of pyrite and uraninite together with kaolinite, as in the Nopal 1 mine, indicating that mineralization and hydrothermal alteration of volcanic tuffs are contemporaneous. Low δ34S values (~ -24.5 ‰) of pyrites intimately associated with uraninite suggest that the reducing conditions at the origin of the U-mineralization arise from biological activity. Later, the uplift of Sierra Pena Blanca resulted in oxidation and remobilization of uranium, as confirmed by the spatial distribution of radiation-induced defect centers in kaolinites. These data show that tectonism and biogenic reducing conditions can play a major role in the formation and remobilization of uranium in epithermal deposits. By comparison with the other uranium deposits at Sierra Pena Blanca and nearby Sierra de Gomez, Nopal 1 deposit is one of the few deposits having retained a reduced uranium mineralization.

  11. Mapping Glacier Dynamics and Proglacial Wetlands with a Multispectral UAV at 5000m in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Wigmore, O.; Mark, B. G.

    2015-12-01

    The glaciers of the Cordillera Blanca, Peru are rapidly retreating as a result of rising temperatures, transforming the hydrology and impacting the socio-economic and environmental systems of the Rio Santa basin. Documenting the heterogeneous spatial patterns of these changes to understand processes of water storage and flow is hindered by technologic and logistic challenges. Highly complex topography, cloud cover and coarse spatial resolution limit the application of satellite data while airborne data collection remains costly and potentially dangerous. However, recent developments have made Unmanned Aerial Vehicle (UAV) technology a viable and potentially transformative method for studying glacier dynamics and proglacial hydrology. The extreme altitudes (4000-6700m) of the Cordillera Blanca limit the use of 'off the shelf' UAVs. Therefore we developed a low cost multispectral (visible, near-infrared and thermal infrared) multirotor UAV capable of conducting fully autonomous aerial surveys at elevations over 5000m within the glacial valleys of the Cordillera Blanca. Using this platform we have completed repeat aerial surveys (in 2014 and 2015) of the debris covered Llaca Glacier, generating highly accurate 10-20cm DEM's and 5cm orthomosaics using a structure from motion workflow. Analysis of these data reveals a highly dynamic system with some areas of the glacier losing as much as 16m of vertical elevation, while other areas have gained up to 5m of elevation over one year. The magnitude and direction of these changes appears to be associated with the presence of debris free ice faces and meltwater ponds. Additionally, we have mapped proglacial meadow and wetland systems. Thermal mosaics at 10-20cm resolution are providing novel insights into the hydrologic pathways of glacier meltwater including mapping the distribution of artesian springs that feed these wetland systems. The high spatial resolution of these UAV datasets facilitates a better understanding of the

  12. Trace elements in mineral separates of the Pena Blanca Spring aubrite - Implications for the evolution of the aubrite parent body

    NASA Technical Reports Server (NTRS)

    Lodders, K.; Palme, H.; Wlotzka, F.

    1993-01-01

    A detailed chemical study is conducted of the Pena Blanca Spring aubrite in order to clarify both the origin of the aubrite parent body (APB) and its relation to the enstatite chondrites. The distribution of REE among aubritic minerals cannot be the result of fractional distillation, which would occur if high degrees of partial melting had occurred on the APB. The REE distributions instead indicate a complete equilibrium of oldhamite and other phases, so that a brief nonequilibrium melting episode must have led to the segregation of metal and sulfides.

  13. Stratigraphy of the PB-1 well, Nopal I uranium deposit, Sierra Pena Blanca, Chihuahua, Mexico

    SciTech Connect

    Dobson, P.; Fayek, M.; Goodell, P.; Ghezzehei, T.; Melchor, F.; Murrell, M.; Oliver, R.; Reyes-Cortes, I.A.; de la Garza, R.; Simmons, A.

    2008-08-01

    The Nopal I site in the Pena Blanca uranium district has a number of geologic and hydrologic similarities to the proposed high-level radioactive waste repository at Yucca Mountain, making it a useful analogue to evaluate process models for radionuclide transport. The PB-1 well was drilled in 2003 at the Nopal I uranium deposit as part of a DOE-sponsored natural analogue study to constrain processes affecting radionuclide transport. The well penetrates through the Tertiary volcanic section down to Cretaceous limestone and intersects the regional aquifer system. The well, drilled along the margin of the Nopal I ore body, was continuously cored to a depth of 250 m, thus providing an opportunity to document the local stratigraphy. Detailed observations of these units were afforded through petrographic description and rock-property measurements of the core, together with geophysical logs of the well. The uppermost unit encountered in the PB-1 well is the Nopal Formation, a densely welded, crystal-rich, rhyolitic ash-flow tuff. This cored section is highly altered and devitrified, with kaolinite, quartz, chlorite, and montmorillonite replacing feldspars and much of the groundmass. Breccia zones within the tuff contain fracture fillings of hematite, limonite, goethite, jarosite, and opal. A zone of intense clay alteration encountered in the depth interval 17.45-22.30 m was interpreted to represent the basal vitrophyre of this unit. Underlying the Nopal Formation is the Coloradas Formation, which consists of a welded lithic-rich rhyolitic ash-flow tuff. The cored section of this unit has undergone devitrification and oxidation, and has a similar alteration mineralogy to that observed in the Nopal tuff. A sharp contact between the Coloradas tuff and the underlying Pozos Formation was observed at a depth of 136.38 m. The Pozos Formation consists of poorly sorted conglomerate containing clasts of subangular to subrounded fragments of volcanic rocks, limestone, and chert

  14. Infrared Imaging and Modeling of Proglacial Stream Temperature in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Baker, E. A.; Lautz, L.; McKenzie, J. M.; Aubry-Wake, C.; Somers, L. D.; Wigmore, O.; Glose, A.; Glas, R. L.; Mark, B. G.

    2015-12-01

    In the tropical Andes, glacial meltwater is an important water resource for downstream communities, especially during the dry season. Due to climate change, glacial retreat is accelerating and straining already limited water resources in the region. It is hypothesized that groundwater storage and discharge will play a critical role in sustaining future river flows. To improve our understanding of the hydrologic fluxes in proglacial valleys of the tropical Andes, we monitored a ~1.2 km reach of the Quilcayhuanca River, in the Cordillera Blanca, Peru, using a high resolution infrared (IR) camera and in-stream temperature sensors. We positioned the IR camera on the southern valley wall, 96 m above the valley floor, and collected >700 IR images at 10 minute intervals over 5 days. We deployed 40 temperature sensors along the stream at ~25 m intervals and 10 sensors at additional control points throughout the surrounding valley, recording temperature at 10 minute intervals. Groundwater temperature was recorded in 6 wells in the study area. The reach had diurnal temperature fluctuations from ~4 to 13°C, but did not exhibit large longitudinal temperature differences. Stream temperature profiles within the water column show stream water is well mixed, improving the ability of the IR camera to accurately observe the stream temperature at this research site. Temperature sensors in 4 reach tributaries recorded warmer temperatures than the main channel. The daily temperatures of one tributary fluctuated within the range of the groundwater temperature (~9 to 11°C), while another tributary exhibited a range of ~18°C. A weather station in the study area recorded climate data (air temperature, humidity, wind speed, solar radiation) at 10 minute intervals. We used this field data as input for a spatial and temporal energy balance model of the reach. Our model demonstrates the utility of IR imagery to monitor stream temperatures and improves our understanding of energy fluxes in

  15. Water Resources and Groundwater in a Glaciated Andean Watershed (Cordillera Blanca, Peru)

    NASA Astrophysics Data System (ADS)

    McKenzie, J. M.; Gordon, R.; Baraer, M.; Lautz, L.; Mark, B. G.; Wigmore, O.; Chavez, D.; Aubry-Wake, C.

    2014-12-01

    It is estimated that almost 400 million people live in watersheds where glaciers provide at least 10% of the runoff, yet many questions remain regarding the impact of climate change and glacier recession on water resources derived from these high mountain watersheds. We present research from the Cordillera Blanca, Peru, an area with the highest density of glaciers in the tropics. While glacier meltwater buffers stream discharge throughout the range, groundwater is a major component of dry season runoff, contributing up to 50-70% of outflow in some tributaries. In order to predict future changes to water resources it is critical to understand how groundwater can offset future hydrologic stress by maintaining stream baseflow, including recharge mechanisms, subsurface pathways, storage, and net fluxes to rivers. We present a synthesis of results based on hydrologic modeling, drilling/piezometers, geophysics, and artificial and natural hydrologic tracers. Our findings show that 'pampas', low-relief mountain valleys, are critical for baseflow generation by storing groundwater on interannual timescales. Pampas have a total area of ~65 km2 and are comprised of unconsolidated glacial, talus, lacustrine and wetland (bofedales) deposits. The valleys commonly have buried talus aquifers that are overlain by low permeability, glaciolacustrine deposits. Glaciofluvial outwash deposits and small wetlands also act as unconfined aquifers. These groundwater systems appear to be primarily recharged by wet season precipitation, and at higher elevations also by glacial meltwater. Additionally a ubiquitous feature in the valleys are springs, often located at the base of talus deposits, which generate a large hydrologic flux within the hydrologic systems. While glaciers are the most visible and vulnerable component of the Andean waterscape, we argue that it is crucial to understand the complete mountain hydrologic cycle, including groundwater, in order to understand the ongoing

  16. Characterization of U-series disequilibria at the Pena Blanca natural analogue site, Chihuahua, Mexico

    SciTech Connect

    Wong, V.; Goodell, P.C.; Anthony, E.Y.

    1999-07-01

    The purpose of this study was to evaluate radionuclide migration from a uranium-mineralized breccia pipe. The site provides an excellent opportunity to evaluate radionuclide mobility in a geochemical environment similar to that around the proposed high-level waste repository at Yucca Mountain, Nevada. Samples represent fracture-infillings from both within and outside the breccia pipe. Mineral assemblages within the fractures include (1) pure kaolinite, (2) a mixture of iron-oxyhydroxides (goethite and hematite) with associated alunite and jarosite, which the authors refer to as the Fe-mineral assemblage, and (3) carbonates. Uranophane, weeksite, soddyite, and boltwoodite are associated with samples from within the breccia zone. The authors obtain radionuclide activities from gamma-ray rather than alpha spectroscopy, and the methodology for these measurements is presented in detail. Plots of {sup 230}Th/{sup 238}U vs. {sup 226}Ra/{sup 230}Th show three distinct mobility trends. (1) The majority of the Fe-mineral samples from within the breccia pipe yield values between 1.0 and 1.1 for both ratios, (2) Fe-mineral samples from outside the ore zone and a kaolinite from within the ore zone have {sup 230}Th/{sup 238}U of 0.58 to 0.83 and {sup 226}Ra/{sup 230}Th of 1.09 to 1.42, and (3) some Fe-mineral samples from within the breccia pipe have values of 1.2 and 0.9 respectively. These data, combined with those from other studies at Pena Blanca suggest that U and Ra are sometimes mobile in the near-surface environment and that multiple episodes of enrichment and leaching are required to explain the trends.

  17. ENSO influence on surface energy and mass balance at Shallap Glacier, Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Maussion, F.; Gurgiser, W.; Großhauser, M.; Kaser, G.; Marzeion, B.

    2015-05-01

    The El Niño/Southern Oscillation (ENSO) is a major driver of climate variability in the tropical Andes, where recent Niño and Niña events left an observable footprint on glacier mass balance. The nature and strength of the relationship between ENSO and glacier mass balance, however, varies between regions and time periods, leaving several unanswered questions about its exact mechanisms. The starting point of this study is a four-year long time series of distributed surface energy and mass balance (SEB/SMB) calculated using a process-based model driven by observations at Shallap Glacier (Cordillera Blanca, Peru). These data are used to calibrate a regression-based downscaling model that links the local SEB/SMB fluxes to atmospheric reanalysis variables on a monthly basis, allowing an unprecedented quantification of the ENSO influence on the SEB/SMB at climatological time scales (1980-2013, ERA-Interim period). We find a stronger and steadier anti-correlation between pacific sea surface temperature (SST) and glacier mass balance than previously reported. This relationship is most pronounced during the wet season (December-May) and at low altitudes where Niño (Niña) events are accompanied with a snowfall deficit (excess) and a higher (lower) radiation energy input. We detect a weaker but significant ENSO anti-correlation with total precipitation (Niño dry signal) and positive correlation with the sensible heat flux, but find no ENSO influence on sublimation. Sensitivity analyses comparing several downscaling methods and reanalysis datasets resulted in stable mass balance correlations with pacific SST but also revealed large uncertainties in computing the mass balance trend of the last decades. The newly introduced open-source downscaling tool can be applied easily to other glaciers in the tropics, opening new research possibilities on even longer time scales.

  18. ENSO influence on surface energy and mass balance at Shallap Glacier, Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Maussion, F.; Gurgiser, W.; Großhauser, M.; Kaser, G.; Marzeion, B.

    2015-08-01

    The El Niño/Southern Oscillation (ENSO) is a major driver of climate variability in the tropical Andes, where recent Niño and Niña events left an observable footprint on glacier mass balance. The nature and strength of the relationship between ENSO and glacier mass balance, however, varies between regions and time periods, leaving several unanswered questions about its exact mechanisms. The starting point of this study is a 4-year long time series of distributed surface energy and mass balance (SEB/SMB) calculated using a process-based model driven by observations at Shallap Glacier (Cordillera Blanca, Peru). These data are used to calibrate a regression-based downscaling model that links the local SEB/SMB fluxes to atmospheric reanalysis variables on a monthly basis, allowing an unprecedented quantification of the ENSO influence on the SEB/SMB at climatological time scales (1980-2013, ERA-Interim period). We find a stronger and steadier anti-correlation between Pacific sea-surface temperature (SST) and glacier mass balance than previously reported. This relationship is most pronounced during the wet season (December-May) and at low altitudes where Niño (Niña) events are accompanied with a snowfall deficit (excess) and a higher (lower) radiation energy input. We detect a weaker but significant ENSO anti-correlation with total precipitation (Niño dry signal) and positive correlation with the sensible heat flux, but find no ENSO influence on sublimation. Sensitivity analyses comparing several downscaling methods and reanalysis data sets resulted in stable mass balance correlations with Pacific SST but also revealed large uncertainties in computing the mass balance trend of the last decades. The newly introduced open-source downscaling tool can be applied easily to other glaciers in the tropics, opening new research possibilities on even longer time scales.

  19. Improved cryopreservation protocol for Blanca-Celtibérica buck semen collected by electroejaculation.

    PubMed

    Jiménez-Rabadán, Pilar; Ramón, Manuel; García-Álvarez, Olga; Maroto-Morales, Alejandro; Alvaro-García, Pablo J; Del Olmo, Enrique; Pérez-Guzmán, M Dolores; Fernández-Santos, M Rocio; Julián Garde, J; Soler, Ana J

    2013-12-01

    The collection of sperm samples by electroejaculation (EE) leads to an increase of the production of seminal plasma which could modify the tolerance of spermatozoa to the cryopreservation procedure. This study aims to compare a standard sperm cryopreservation protocol for samples collected by artificial vagina (AV) with the same protocol and modifications to this for samples obtained by EE. Semen from six males of Blanca-Celtibérica goat breed was collected by AV (control) and EE, and three experiments were conducted. In Experiment 1, it was examined the effects of egg yolk concentration contained in freezing extender (0%, 1.5%, 10% and 20% of egg yolk); in Experiment 2, it was evaluated the cooling rate from 30 to 5 °C (fast: 10 min and slow: 90 min) and the temperature of glycerol addition (30 and 5 °C); and in Experiment 3, it was examined the time of equilibration at 5 °C (0, 1, 2 or 3h). A heterologous in vitro fertilization test was carried out in order to compare the fertility of control samples with that resulting from the EE protocol which showed the highest sperm quality. Results showed greater sperm motility parameters after thawing for control samples cryopreserved in standard conditions in the three experiments. For samples collected by EE, extender with 20% egg yolk, a slow cooling rate and a longer equilibration time (3h) provided higher sperm quality, and no differences were observed between temperatures of glycerol addition. Samples collected by EE and cryopreserved with the protocol which yielded the best sperm quality after thawing showed higher fertility compared to AV. PMID:23958413

  20. New measurements of particulates in glacial snow and ice in the Cordillera Blanca mountains of Peru

    NASA Astrophysics Data System (ADS)

    All, J.; Schmitt, C.; Celestian, A. J.; Rucks, M.; Arnott, W. P.; Cole, R.

    2012-12-01

    During the local dry season (June/July) of 2011 and 2012, the American Climber Science Program (organized with the assistance of the American Alpine Club) conducted scientific expeditions in Huascaran National Park in Peru. The Park is located in the Cordillera Blanca mountain range and contains the world's largest collection of tropical mountain glaciers. One component of the environmental research program was sampling particulates on glacier surfaces by means of snow collection and filtration. Over 150 samples were collected during the two expeditions by volunteer climbers working with scientists in the field. Glacier snows were collected on over fifteen peaks throughout the range at altitudes from 4800 to nearly 6800 meters. Snow samples were kept frozen until the climber-scientists returned to basecamp - at which point they were rapidly melted and then immediately filtered through 0.7 micron PallFlex tissuequartz filters. The particulates captured on the filters have been analyzed for their bulk heat absorption properties as well as to determine the properties of individual particles through X-ray diffraction for bulk mineral identification, and Raman microscopy for chemical mapping of minerals. Preliminary results indicate that snow age, altitude, as well as geographic location (with respect to urban areas, mines, and predominant wind direction) all play significant roles in the amount and types of contaminants. Multiple locations were sampled during both expeditions as well as at different times during the same climbing season. Results include the relative heating capacity of the samples at various wavelengths as well as mineral composition information across the range. Local weather patterns and geographic observations will be used to identify potential sources of contaminants. Sampling will continue under the American Climber Science Program in 2013 and beyond.

  1. Recent trends in annual snowline variations in the northern wet outer tropics: case studies from southern Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Veettil, Bijeesh Kozhikkodan; Wang, Shanshan; Bremer, Ulisses Franz; de Souza, Sergio Florêncio; Simões, Jefferson Cardia

    2016-03-01

    This paper describes the changes in the annual maximum snowlines of a selected set of mountain glaciers at the southern end of the Cordillera Blanca between 1984 and 2015 using satellite images. Furthermore, we analysed the existing glacier records in the Cordillera Blanca since the last glacial maximum to understand the evolution of glaciers in this region over a few centuries. There was a rise in the snowline altitude of glaciers in this region since the late 1990s with a few small glacier advances. Historical to the present El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) records were also analysed to understand whether there was a teleconnection between the glacier fluctuations in the region and the phase changes of ENSO and PDO. We also assessed the variations in three important climatic parameters that influence the glacier retreat—temperature, precipitation, and relative humidity—over a few decades. We calculated the anomalies as well as the seasonal changes in these variables since the mid-twentieth century. There was an increase in temperature during this period, and the decrease in precipitation was not so prominent compared with the temperature rise. There was an exceptionally higher increase in relative humidity since the early 2000s, which is relatively higher than that expected due to the observed rate of warming, and this increase in humidity is believed to be the reason behind the unprecedented rise in the snowline altitudes since the beginning of the twenty-first century.

  2. Role of plate kinematics and plate-slip-vector partitioning in continental magmatic arcs: Evidence from the Cordillera Blanca, Peru

    SciTech Connect

    McNulty, B.A.; Farber, D.L.; Wallace, G.S.; Lopez, R.; Palacios, O.

    1998-09-01

    New structural and geochronological data from the Cordillera Blanca batholith in the Peruvian Andes, coupled with Nazca-South American plate-slip-vector data, indicate that oblique convergence and associated strike-slip partitioning strongly influenced continental magmatic arc evolution. Both the strain field and mode of magmatism (plutonism vs. volcanism) in the late Miocene Peruvian Andes were controlled by the degree to which the arc-parallel component of the plate slip vector was partitioned into the arc. Strong strike-slip partitioning at ca. 8 Ma produced arc-parallel sinistral shear, strike-slip intercordilleran basins and east-west-oriented tension fractures that facilitated emplacement of the Cordillera Blanca batholith (ca. 8.2 {+-} 0.2 Ma). Periods during which the strike-slip component was not partitioned into the arc (ca. 10 and ca. 7 Ma) were associated with roughly arc-normal contraction and ignimbrite volcanism. The data thus support the contention that contraction within continental magmatic arcs favors volcanism, whereas transcurrent shear favors plutonism. The tie between oblique convergence and batholith emplacement in late Miocene Peruvian Andes provides a modern analogue for batholiths emplaced as the result of transcurrent shear in ancient arcs.

  3. Geochronology and Fluid-Rock Interaction Associated with the Nopal I Uranium Deposit, Pena Blanca, Mexico

    SciTech Connect

    M. Fayek; P. Goodell; M. Ren; A. Simmons

    2005-07-11

    The Nopal I uranium (U) deposit, Pena Blanca District, Mexico, largely consists of secondary U{sup 6+} minerals, which occur within a breccia pipe mainly hosted by the 44 Ma Nopal and Colorados volcanic formations. These two units overly the Pozos conglomerate formation and Cretaceous limestone. Three new vertical diamond drill holes (DDHs) were recently drilled at Nopal I. DDH-PB1 with continuous core was drilled through the Nopal I deposit and two additional DDHs were drilled {approx}50 m on either side of the cored hole. These DDHs terminate 20 m below the current water table, thus allowing the detection of possible gradients in radionuclide contents resulting from transport from the overlying uranium deposit. Primary uraninite within the main ore body is rare and fine-grained ({approx}50 micrometers), thus making geochronology of the Nopal I deposit very difficult. Uranium, lead and oxygen isotopes can be used to study fluid-uraninite interaction, provided that the analyses are obtained on the micro-scale. Secondary ionization mass spectrometry (SIMS) permits in situ measurement of isotopic ratios with a spatial resolution on the scale of a few {micro}m. Preliminary U-Pb results show that uraninite from the main ore body gives an age of 32 {+-} 8 Ma, whereas uraninite from the uraniferous Pozos conglomerate that lies nearly 100 m below the main ore body and 25 meters above the water table, gives a U-Pb age that is <1 Ma. Oxygen isotopic analyses show that uraninite from the ore body has a {delta}{sup 18}O = -10.8{per_thousand}, whereas the uraninite within the Pozos conglomerate has a {delta}{sup 18}O = +1.5{per_thousand}. If it is assumed that both uraninites precipitated from meteoric water ({delta}{sup 18}O = -7{per_thousand}), then calculated precipitation temperatures are 55 C for the uraninite from the ore body and 20 C for uraninite hosted by the Pozos conglomerate. These temperatures are consistent with previous studies that calculated precipitation

  4. Cooling History for the Sierra Laguna Blanca (NW Argentina) on the Southern Puna Plateau, Central Andes

    NASA Astrophysics Data System (ADS)

    Zhou, R.; Schoenbohm, L. M.; Sobel, E. R.; Stockli, D. F.; Glodny, J.

    2014-12-01

    Various dynamic models have been proposed to explain deformation history and topographic evolution for the southern Altiplano-Puna Plateau, including inversion of the Cretaceous Salta rift structures, formation of an orogenic wedge, flat subduction, climate-tectonic coupling, and lithospheric foundering. Controversies persist in the southern Puna Plateau, where preexisting rift structures are unknown and Cenozoic shortening events are sparsely documented. The 6-km high Sierra Laguna Blanca (LB) (NW Argentina) is among the most outstanding topographic features in the interior of the southern Puna Plateau. We document cooling history for LB with apatite (U-Th)/He, apatite fission-track and zircon (U-Th)/He thermochronometers for a vertical profile from 3.6-5.6 km on its eastern flank. Preliminary results from apatite fission-track (AFT) analysis yield ages ranging from 45-65 Ma, with top samples being the oldest. Dpar values for all samples are low (1.54 to 1.74), suggesting a relatively low-temperature partial annealing zone. All samples have shortened mean track lengths ranging from 10.9 to 12.3 micrometers, suggesting partial resetting. Preliminary apatite U-Th/He (AHe) ages are compatible with AFT ages but are widely dispersed, perhaps due to U zoning and small U-rich inclusions which have been observed on AFT external detectors. Inverse modeling of AFT data and selected AHe data using the HeFTy program reveal two major cooling events for LB. All models start ~90-70 Ma and immediately decrease their temperatures to ~60°C before ~50 Ma. Samples may have stayed ~60°C without additional thermal events until ~15-10 Ma, when the most recent cooling event took place, bringing all samples to surface temperature. Our first finding is that the interior of the southern Puna Plateau may have been influenced by the Salta Rift during the Cretaceous, extending the known zone of influence further west. Second, the most recent cooling phase (mid-late Miocene) is consistent

  5. U-Sries Disequilibra in Soils, Pena Blanca Natural Analog, Chihuahua, Mexico

    SciTech Connect

    D. French; E. Anthony; P. Goodell

    2006-03-16

    The Nopal I uranium deposit located in the Sierra Pena Blanca, Mexico. The deposit was mined in the early 1980s, and ore was stockpiled close by. This stockpile area was cleared and is now referred to as the Prior High Grade Stockpile (PHGS). Some of the high-grade boulders from the site rolled downhill when it was cleared in the 1990s. For this study soil samples were collected from the alluvium surrounding and underlying one of these boulders. A bulk sample of the boulder was also collected. Because the Prior High Grade Stockpile had no ore prior to the 1980s a maximum residence time for the boulder is about 25 years, this also means that the soil was at background as well. The purpose of this study is to characterize the transport of uranium series radionuclides from ore to the soil. Transport is characterized by determining the activities of individual radionuclides and daughter to parent ratios. Isotopes of the uranium series decay chain detected include {sup 210}Pb, {sup 234}U, {sup 230}Th, {sup 226}Ra, {sup 214}Pb, and {sup 214}Bi. Peak areas for each isotope are determined using gamma-ray spectroscopy with a Canberra Ge (Li) detector and GENIE 2000 software. The boulder sample is close to secular equilibrium when compared to the standard BL-5 (Beaver Lodge Uraninite from Canada). Results for the soils, however, indicate that some daughter/parent pairs are in secular disequilibrium. These daughter/parent (D/P) ratios include {sup 230}Th/{sup 234}U, which is greater than unity, {sup 226}Ra/{sup 230}Th, which is also greater than unity, and {sup 210}Pb/{sup 214}Bi, which is less than unity. The gamma-ray spectrum for organic material lacks {sup 230}Th peaks, but contains {sup 234}U and {sup 226}Ra, indicating that plants preferentially incorporate {sup 226}Ra. Our results, combined with previous studies require multistage history of mobilization of the uranium series radionuclides. Earlier studies at the ore zone could limit the time span for mobilization only

  6. Evolución de estrellas enanas blancas de Helio de masa baja e intermedia

    NASA Astrophysics Data System (ADS)

    Althaus, L. G.; Benvenuto, O. G.

    Numerosas observaciones realizadas particularmente en los últimos dos años parecen confirmar que las enanas blancas (EB) de helio de masa baja e intermedia son el resultado de la evolución de sistemas binarios cercanos. Con el objeto de realizar una adecuada interpretación de estos objetos son necesarios modelos de EBs de helio lo más detallado posibles. En este estudio presentamos cálculos detallados de la evolución de EBs de helio con masas entre M=0.1Msolar y M=0.5Msolar a intervalos de 0.05Msolar . Para ello, hemos tenido en cuenta los efectos de temperatura finita mediante un código de evolución estelar lo más actualizado posible. En particular, el transporte de energía es descripto en el marco del nuevo modelo para la convección turbulenta desarrollado por Canuto - Mazzitelli. Además hemos considerado la nueva ecuación de estado para plasmas de helio de Saumon et al. y nuevas opacidades radiativas OPAL. Las pérdidas por neutrinos fueron asimismo tenidas en cuenta. Excepto para las EBs más masivas, nuestros modelos iniciales están ubicados en las cercanías de la correspondiente línea de Hayashi para configuraciones de helio. Nuestros resultados muestran que existe una región prohibida en el diagrama observacional HR donde ninguna EB de helio puede encontrarse. Dicha región es para log{(L/Lsolar )}>= -0.25 and log{Teff} >= 4.45. Hemos encontrado también que los tracks evolutivos en el diagrama HR en el dominio de alta luminosidad (pre - EB) son fuertemente afectados por la eficiencia convectiva y que las pérdidas por neutrinos son importantes en los modelos más masivos. Finalmente hemos analizado la estructura de la zona convectiva externa encontrando que la teoría de Canuto - Mazzitelli conduce a un perfil convectivo muy diferente del dado por cualquier versión de la popular teoría de la mixing length. Si bién este comportamiento es decisivo en el contexto de las inestabilides pulsacionales, los radios y gravedades superficiales de

  7. Geologic Mapping in Nogal Peak Quadrangle: Geochemistry, Intrusive Relations and Mineralization in the Sierra Blanca Igneous Complex, New Mexico

    NASA Astrophysics Data System (ADS)

    Goff, F.; Kelley, S. A.; Lawrence, J. R.; Cikowski, C. T.; Krier, D. J.; Goff, C. J.; McLemore, V. T.

    2011-12-01

    Nogal Peak quadrangle is located in the northern Sierra Blanca Igneous Complex (SBIC) and contains most of the White Mountain Wilderness (geologic map is available at http://geoinfo.nmt.edu/publications/maps/geologic/ofgm/details.cfml?Volume=134). The geology of the quad consists of a late Eocene to Oligocene volcanic pile (Sierra Blanca Volcanics, mostly alkali basalt to trachyte) intruded by a multitude of dikes, plugs and three stocks: Rialto, 31.4 Ma (mostly syenite), Three Rivers, ca. 29 to 27 Ma (quartz syenite intruded by subordinate alkali granite), and Bonito Lake, 26.6 Ma (mostly monzonite). Three Rivers stock is partially surrounded by alkali rhyolites that geochemically resemble the alkali granites. The circular shape of the stock and surrounding rhyolites suggests they form the root of a probable caldera. SBIC rocks have compositions typical of those found within the Rocky Mountain alkaline belt and those associated with continental rift zone magmatism. Because the volcanic host rocks are deeply eroded, intrusive relations with the stocks are well exposed. Most contacts at stock margins are near vertical. Roof pendants are common near some contacts and stoped blocks up to 700 m long are found within the Three Rivers stock. Contacts, pendants and stoped blocks generally display some combination of hornfelsing, brecciation, fracturing, faulting and mineralization. Sierra Blanca Volcanics display hydrothermal alteration increasing from argillic in the NW sector of the quad to high-temperature porpylitic near stock margins. Retrograde phyllic alteration occurs within breccia pipes and portions of the stocks. Mineral deposits consist of four types: Placer Au, fissure veins (mostly Ag-Pb-Zn±Au), breccia pipes (Au-Mo-Cu), and porphyry Mo-Cu. A singular pipe on the SW margin of Bonito Lake stock contains sapphire-lazulite-alunite. Although Au has been intermittently mined in the quad since 1865, best production of Au originated around the turn of the last

  8. Glacier Changes in the Cordillera Blanca, Peru, Derived From SPOT5 Imagery, GIS and Field- Based Measurements

    NASA Astrophysics Data System (ADS)

    Racoviteanu, A.; Arnaud, Y.; Williams, M. W.; Singh Khalsa, S.

    2007-12-01

    There is urgency in deriving an extensive dataset for deriving glacier changes within the Cordillera Blanca, Peru, in a cost-effective and timely manner. Rapid glacial retreat during the last decades in this area poses a threat for water resources, hydroelectric power and local traditions. While there is some information on decadal changes in glacier extents, there still remains a paucity of mass balance measurements and glacier parameters such as hypsometry, size distribution and termini elevations. Here we investigate decadal changes in glacier parameters for Cordillera Blanca of Peru using data from Système Probatoire d'Observation de la Terre (SPOT) sensor, an old glacier inventory from 1970 aerial photography, field-based mass balance measurements and meteorological observations. Here we focus on: constructing a geospatial glacier inventory from 2003 SPOT scenes; mass balance estimations using remote sensing and field data; frequency distribution of glacier area; changes in termini elevations; hypsometry changes over time; glacier topography (slope, aspect, length/width ratio); AAR vs. mass balance for Artesonraju and Yanamarey benchmark glaciers; precipitation and temperature trends in the region. Over the last 25 years, mean temperatures increases of 0.09 deg.C/yr were greater at lower elevation than the 0.01 deg.C/yr at higher elevations, with little change in precipitation. Comparison of the new SPOT-based glacier inventory with the 1970 inventory shows that glaciers in Cordillera Blanca retreated at a rate of 0.6% per year over the last three decades, with no significant differences in the rate of area loss between E and W side. At lower elevations there is an upward shift of glacier termini along with a decrease in glacier area. Small glaciers are losing more area than large glaciers. Based on the relationship between specific mass balance (bn) and accumulation area ratio (AAR) for the two benchmark glaciers, we predicted a steady-state equilibrium line

  9. How many populations set foot through the Patagonian door? Genetic composition of the current population of Bahía Blanca (Argentina) based on data from 19 Alu polymorphisms.

    PubMed

    Resano, M; Esteban, E; González-Pérez, E; Vía, M; Athanasiadis, G; Avena, S; Goicoechea, A; Bartomioli, M; Fernández, V; Cabrera, A; Dejean, C; Carnese, F; Moral, P

    2007-01-01

    The city of Bahía Blanca occupies a strategic place in Argentina south of the Pampean region in the north-east corner of the Patagonia. Since 1828, this city has been the historical and political border between Amerindian lands in the south, and the lands of European colonists. Nowadays, Bahía Blanca is an urban population mainly composed by descendents of immigrants from Spain and other European countries with apparently low admixture with Amerindians. In view of the unexpectedly high Amerindian admixture levels (about 46.7%) suggested by mtDNA data, and protein markers (19.5%), we analyzed a set of 19 Alu polymorphisms (18 autosomal, 1 of Chromosome Y) in a well-documented genealogical sample from Bahía Blanca. The genotyped sample was made up of 119 unrelated healthy individuals whose birth place and grandparent origins were fully documented. According to available genealogical records, the total sample has been subdivided into two groups: Bahía Blanca Original (64 individuals with all 4 gandparents born in Argentina) and Bahía Blanca Mix (55 individuals with one to three grandparents born out of Argentina). Allele frequencies and gene diversity values in Bahía Blanca fit well into the European ranges. Population relationships have been tested for 8 Alu markers, whose variation has been described in several Amerindian and European samples. Reynolds genetic distances underline the significant genetic similarity of Bahía Blanca to Europeans (mean distance 0.044) and their differentiation from Amerindians (0.146). Interestingly enough, when the general sample is divided, Bahía Blanca Original appears slightly closer to Amerindians (0.127) in contrast to Bahía Blanca Mix (0.161). Furthermore, the genetic relationships depicted through a principal components analysis emphasize the relative similarity of Bahía Blanca Original to Amerindians. A thorough knowledge of the sample origins has allowed us to make a subtle distinction of the genetic composition of

  10. Relationship of physical factors and salinity with indicator bacteria in Bahía Blanca estuary waters, Argentina.

    PubMed

    Cabezali, C B; Baldini, M D; Burgos, M A; Arango, J M

    1994-01-01

    The relationship between the number of Escherichia coli, terrestrial and marine heterotrophic bacteria, with certain physical and chemical parameters in Bahia Blanca estuary waters, were investigated by means of a statistical analysis of multiple linear regression. The samples were taken during a period of 16 months. Although distance from the sewage outlet seems to be the factor having the greatest effect on the number of alien bacteria, the models obtained for E. coli are inappropriate to predict bacterial behaviour in this particular natural habitat, while for heterotrophic bacteria descriptive models were selected. The results of this study suggest that many factors affect bacterial population densities in this estuarine ecosystem. This should be taken into account trying to solve the problem in order to avoid progressive degradation. PMID:7938503

  11. Legendary lost city Ciudad Blanca found under tropical forest in Honduras, using ERS-2 and JERS-1 SAR imagery

    NASA Astrophysics Data System (ADS)

    Yakam-Simen, Francis; Nezry, Edmond; Ewing, James J.; Maschal, Ted

    1998-10-01

    The legendary 'Ciudad Blanca' of Honduras was first referred to under the name Xucutaco by the Spanish conquistador Hernan Cortes already in 1526. Located in the remote, impenetrable and incompletely mapped rainforest of the Mosquito Coast, it was never conquered by the Spanish. With the time, it was slowly abandoned and forgotten. Two JERS-1 and one ERS-2 SLC Synthetic Aperture Radar (SAR) images have been used to identify and to locate the lost city, a task made difficult due to the thick vegetation cover. To this end, advanced processing tools for the detection of artificial targets under forest cover, and for SAR data fusion have been used. Among the techniques used, a new Bayesian Distribution Entropy Maximum A Posteriori (DE-MAP) vector speckle filter, particularly suited for the restoration of a strongly textured scene, has been used to enhance the SAR images. This new speckle filter incorporates a statistical description of the effects of the SAR imaging system: in order to account for the effects due to the spatial correlation of the speckle in SAR images, an estimator originating from the local spatial autocorrelation function (ACF) of the SAR signal are incorporated to this filter, to refine the evaluation of the non-stationary first order local statistics, to improve the restoration of the scene textural properties, and to preserve the useful spatial resolution in the speckle filtered image. On the other hand, radargrammetric techniques have been used to: (1) produce a Digital Elevation Model (DEM) of the study area; (2) fuse ERS and JERS information in order to allow visual identification of the remnants of Ciudad Blanca by visual photo-interpretation. Using the processed images, geocoded UTM spatio-maps of the region have also been produced to locate accurately our findings, and guide a ground expedition in the future.

  12. Characterization of Quartz and Feldspar Deformation in the Mid-crust: Insights from the Cordillera Blanca Shear Zone, Peru

    NASA Astrophysics Data System (ADS)

    Hughes, C. A.; Jessup, M. J.; Shaw, C. A.

    2014-12-01

    Deformation mechanisms within shear zones from various crustal levels must be characterized to develop accurate models of lithospheric rheology. The Cordillera Blanca Shear Zone (CBSZ) in the central Peruvian Andes records changes in temperature, microstructures, and deformation mechanisms that occurred during exhumation through the brittle-ductile-transition during normal-sense slip over the last ~5 m.y. The 100-500-m-thick mylonitic shear zone occupies the footwall of a 200-km-long normal detachment fault, marking the western boundary of the 8 Ma, leucogranodiorite Cordillera Blanca Batholith. Though local variations do occur, including recrystallized quartz veins and local, decimeter- to meter- scale shear zones, the CBSZ follows a general trend of increasing strain towards the detachment. Structurally lowest positions are weakly deformed and transition to protomylonite, mylonite, and ultramylonite at higher positions, truncating at a cataclasite nearest the detachment. We characterize strain using EBSD analyses of quartz lattice preferred orientations and deformation temperatures using quartz and feldspar textures and two-feldspar thermometry of asymmetric strain-induced myrmekite. At the deepest structural positions, feldspar grains record a complex history characterized by bulging recrystallization, myrmekite formation, and brittle fracture, while quartz exhibits dominant grain-boundary migration recrystallization (T> 500 °C) and prism slip. Intermediate samples exhibit more prevalent strain-induced myrmekite, brittle fracture in feldspar, and reaction-associated recrystallization of K-feldspar to mica; quartz records mainly subgrain-rotation recrystallization (400-500 °C) and dominant prism slip with a rhomb component. Shallower positions preserve fewer, smaller, and more rounded feldspar porphyroclasts with no myrmekite, and dominant bulging recrystallization (280-400 °C) in quartz that records prism , rhomb , and some basal slip.

  13. From the Cordillera Blanca to the Pacific Ocean: hydrological changes and consequences across the Rio Santa watershed

    NASA Astrophysics Data System (ADS)

    Baraer, M.; Mark, B. G.; Wigmore, O.; Fernandez-Rivera, A.; McKenzie, J. M.; Walsh, E.

    2012-12-01

    The Rio Santa, Peru, drains the western slopes of the glacierized Cordillera Blanca and provides water resources for intense and diversified purposes. The Rio Santa basin sustains one of the most important hydropower plants in Peru, several middle-sized cities, high-elevation slope agriculture and mining industries. Glaciers in the Cordillera Blanca are rapidly retreating, modifying the hydrology of the upper Rio Santa watershed. Previous results show that the upper Rio Santa watershed has passed peak-water, the moment of maximum water availability, and now exhibit decreasing dry season discharge as a consequence of glacial retreat. We present results from data collected in July of 2011 and 2012, including discharge measurements using acoustic Doppler current profiling and major dissolved ion concentrations and stable isotopes of water. The hydrochemical data were analysed using the Hydrochemical Basin Characterization Method and the results are used to map the dry-season specific discharge variations across the entire Rio Santa watershed. Measurements from 2011 suggest that around 80% of current lower Rio Santa dry-season flows are diverted to supply water to major cities, intensive agriculture and hydro-electricity projects situated in the dry coastal area. Glacier retreat simulations are used to localize future hydrological changes and evaluate the downstream repercussions. Results show that glacierized catchments have higher specific discharge compared to non-glacierized catchments but the contribution of the glaciers during the dry season represent less than 30% of the Rio Santa discharge. As the glaciers further retreat, the Rio Santa dry-season outflows are going to progressively decrease to a level below the actual freshwater demand. These changes will adversely impact the socioeconomic vulnerability to water scarcity in the entire watershed while deepening the upstream/downstream disparity in water availability.

  14. Recalibration of the yellow Rhizocarpon growth curve in the Cordillera Blanca (Peru) and implications for LIA chronology

    NASA Astrophysics Data System (ADS)

    Jomelli, V.; Grancher, D.; Brunstein, D.; Solomina, O.

    2008-01-01

    A new lichen dating method and new moraine observations enabled us to improve the chronology of glacier advances in the Cordillera Blanca (Peru) during the Little Ice Age (LIA). Our results reveal that an early LIA glacial advance occurred around AD 1330 ± 29. However, a second major glacial advance at the beginning of the 17th century overlapped the earlier stage for most glaciers. Hence, this second glacial stage, dated from AD 1630 ± 27, is considered as the LIA maximum glacial advance in the Cordillera Blanca. During the 17th-18th centuries, at least three glacial advances were recorded synchronously for the different glaciers (AD 1670 ± 24, 1730 ± 21, and 1760 ± 19). The moraines corresponding to the two first stages are close to the one in 1630 suggesting a slow recession of about 18% in the total length of the glacier. From the LIA maximum extent to the beginning of the 20th century, the 24 glaciers have retreated a distance of about 1000 m, corresponding to a reduction of 30% in their length. This rate is comparable to that observed during the 20th century. Estimates of palaeo-Equilibrium Line Altitudes show an increase in altitude of about 100 m from the LIA maximum glacial extension at the beginning of the 17th century to the beginning of the 20th century. Because long time series are not available for precipitation and temperature, this glacial retreat is difficult to explain by past climate changes. However, there is a fair correspondence between changes in glacier length and the δ18O recorded in the Quelccaya ice core at a century timescale. Our current knowledge of tropical glaciers and isotope variations leads us to suggest that this common tropical signal reflects a change from a wet LIA to the drier conditions of today. Finally, a remarkable synchronicity is observed with glacial variations in Bolivia, suggesting a common regional climatic pattern during the LIA.

  15. Emerging Glacial Lakes in the Cordillera Blanca, Peru: A Case Study at Arteson Glacier

    NASA Astrophysics Data System (ADS)

    Chisolm, R. E.; Mckinney, D. C.; Gomez, J.; Voss, K.

    2012-12-01

    Tropical glaciers are an essential component of the water resources systems in the mountainous regions where they are located, and a warming climate has resulted in the accelerated retreat of Andean glaciers in recent decades. The shrinkage of Andean glaciers influences the flood risk for communities living downstream as new glacial lakes have begun to form at the termini of some glaciers. As these lakes continue to grow in area and volume, they pose an increasing risk of glacial lake outburst floods (GLOFs). Ice thickness measurements have been a key missing link in studying the tropical glaciers in Peru and how climate change is likely to impact glacial melt and the growth of glacial lakes. Ground penetrating radar (GPR) has rarely been applied to glaciers in Peru to measure ice thickness, and these measurements can tell us a lot about how a warming climate will affect glacier mass balance. This study presents GPR data taken in July 2012 at the Arteson glacier in the Cordillera Blanca, Peru. A new lake has begun to form at the terminus of the Arteson glacier, and this lake has key features, including overhanging ice and loose rock likely to create landslides, that could trigger a catastrophic GLOF if the lake continues to grow. This new lake is part of a series of three lakes that have formed below the Arteson glacier. The two lower lakes, Artesonraju and Paron, are much larger so that if there were an avalanche or landslide into the new lake below Arteson glacier, the impact could potentially be more catastrophic than a GLOF from one single lake. Estimates of how the lake mass balance is likely to evolve due to the retreating glacier are key to assessing the flood risk from this dynamic three-lake system. Because the glacier mass balance and lake mass balance are closely linked, the ice thickness measurements and measurements of the bed slope of the Arteson glacier and underlying bedrock give us a clue to how the lake is likely to evolve. GPR measurements of

  16. Modeling of U-series Radionuclide Transport Through Soil at Pena Blanca, Chihuahua, Mexico

    NASA Astrophysics Data System (ADS)

    Pekar, K. E.; Goodell, P. C.; Walton, J. C.; Anthony, E. Y.; Ren, M.

    2007-05-01

    The Nopal I uranium deposit is located at Pena Blanca in Chihuahua, Mexico. Mining of high-grade uranium ore occurred in the early 1980s, with the ore stockpiled nearby. The stockpile was mostly cleared in the 1990s; however, some of the high-grade boulders have remained there, creating localized sources of radioactivity for a period of 25-30 years. This provides a unique opportunity to study radionuclide transport, because the study area did not have any uranium contamination predating the stockpile in the 1980s. One high-grade boulder was selected for study based upon its shape, location, and high activity. The presumed drip-line off of the boulder was marked, samples from the boulder surface were taken, and then the boulder was moved several feet away. Soil samples were taken from directly beneath the boulder, around the drip-line, and down slope. Eight of these samples were collected in a vertical profile directly beneath the boulder. Visible flakes of boulder material were removed from the surficial soil samples, because they would have higher concentrations of U-series radionuclides and cause the activities in the soil samples to be excessively high. The vertical sampling profile used 2-inch thicknesses for each sample. The soil samples were packaged into thin plastic containers to minimize the attenuation and to standardize sample geometry, and then they were analyzed by gamma-ray spectroscopy with a Ge(Li) detector for Th-234, Pa-234, U-234, Th-230, Ra-226, Pb-214, Bi-214, and Pb-210. The raw counts were corrected for self-attenuation and normalized using BL-5, a uranium standard from Beaverlodge, Saskatchewan. BL-5 allowed the counts obtained on the Ge(Li) to be referenced to a known concentration or activity, which was then applied to the soil unknowns for a reliable calculation of their concentrations. Gamma ray spectra of five soil samples from the vertical profile exhibit decreasing activities with increasing depth for the selected radionuclides

  17. GAMMA-RAY CHARACTERIZATION OF THE U-SERIES INTERMEDIATE DAUGHTERS FROM SOIL SAMPLES AT THE PENA BLANCA NATURAL ANALOG, CHIHUAHUA, MEXICO

    SciTech Connect

    D.C. French; E.Y. Anthony; P.C. Goodell

    2005-07-18

    The Pena Blanca natural analog is located in the Sierra Pena Blanca, approximately 50 miles north of Chihuahua City, Mexico. The Sierra Pena Blanca is composed mainly of ash-flow tuffs, and the uranium in the region is contained in the brecciated zones of these tuffs. The Pena Blanca site is considered a natural analog to the proposed Yucca Mountain Nuclear Waste Repository because they share similar characteristics of structure, volcanic lithology, tectonic activity, and hydrologic regime. One of the mineralized zones, the Nopal I deposit, was mined in the early 1980s and the ore was stockpiled close to the mine. This stockpile area has subsequently been cleared and is referred to as the prior high-grade stockpile (PHGS) site. Soil surrounding boulders of high-grade ore associated with the PHGS site have been sampled. The purpose of this study is to characterize the transport of uranium series radioisotopes from the boulder to the soil during the past 25 years. Transport is characterized by determining the activities of individual radionuclides and daughter to parent ratios. The daughter to parent ratios are used to establish whether the samples are in secular equilibrium. Activities are determined using gamma-ray spectroscopy. Isotopes of the uranium series decay chain detected by gamma-ray spectroscopy include {sup 210}Pb, {sup 234}U, {sup 234}Th, {sup 230}Th, {sup 226}Ra, {sup 214}Pb, {sup 214}Bi, and {sup 234}Pa. Preliminary results indicate that some daughter to parent pairs appear to be in secular disequilibrium. Thorium is in excess relative to uranium, and radium is in excess relative to thorium. A deficiency appears to exist for {sup 210}Pb relative to {sup 214}Bi and {sup 214}Pb. If these results are borne out by further analysis, they would suggest transport of nuclides from the high-grade boulder into its surroundings, followed by continued leaching of uranium and lead from the environment.

  18. Digital aeromagnetic data and derivative products from a helicopter survey over the town of Blanca and surrounding areas, Alamosa and Costilla counties, Colorado

    USGS Publications Warehouse

    Bankey, Viki; Grauch, V.J.S.; Fugro Airborne Surveys Corporation

    2004-01-01

    This CD-ROM contains digital data, image files, and text files describing data formats and survey procedures for aeromagnetic data collected during a helicopter geophysical survey in southern Colorado during October 2003. The survey covers the town of Blanca and surrounding communities in Alamosa and Costilla Counties. Several derivative products from these data are also presented, including reduced-to-pole, horizontal gradient magnitude, and downward continued grids and images.

  19. Evaluating glacier volume changes since the Little Ice Age maximum and consequences for stream flow by integrating models of glacier flow and hydrology in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Huh, K. I.; Mark, B. G.; Baraer, M.; Ahn, Y.

    2014-12-01

    Assessing the historical contribution of glacier ice volume loss to stream flow based on reconstructed volume changes through Little Ice Age (LIA) can be directly related to the understanding of glacier-hydrology in the current epoch of rapid glacier ice loss that has disquieting implications for water resources in the Cordillera Blanca of the Peruvian Andes. However, the accurate prediction of the future glacial meltwater availability for the increasing regional Andean society needs more extensive quantitative estimation from long-term glacial meltwater of reconstructed glacial volume. Modeling LIA paleoglaciers using a cellular automata glacier flow model in different catchments of the Cordillera Blanca allows us to reconstruct glacier volume and its change from likely combinations of climatic control variables and time. We compute the rate and magnitude of glacier volume changes for Yanamarey and Queshque glaciers between the LIA and modern defined by 2011 Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model Version 2 (GDEM V2) from the Cordillera Blanca. Also, we employ a recently demonstrated hydrological stream model (Baraer et al., 2012) for integrating the reconstructed glacier volume and its change to calculate glacier contribution to meltwater runoff as a function of glacier loss rate in the Yanamarey and the Queshque catchments, and reconstruct long-term glacier significance to stream flow.

  20. Mantle to Surface Fluid Transfer Above a Flat Slab Subduction Zone: Isotopic Evidence from Hot Springs in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Newell, D. L.; Jessup, M. J.; Hilton, D. R.; Shaw, C. A.; Hughes, C. A.

    2015-12-01

    Thermal springs in the Cordillera Blanca, Peru, provide geochemical evidence for deeply circulated hydrothermal fluids that carry significant mantle-derived helium. The Cordillera Blanca is a ~200 km-long NNW-SSE trending mountain range in the Peruvian Andes located above an amagmatic flat-slab subduction segment. The west side of the range is bounded by the Cordillera Blanca detachment that preserves a progression of top to the west ductile shear to brittle normal faulting since ~5 Ma. We report aqueous and stable isotope geochemical results from fluid and gas samples collected in 2013 and 2015 from 13 hot springs emanating from the Cordillera Blanca detachment and associated hanging wall faults. Most springs are vigorously bubbling (degassing), and range in temperature, pH, and conductivity from 17-89 °C, 5.95-8.87, and 0.17-21.5 mS, respectively. The hottest springs issue directly from the northern segment of the detachment. Geochemically, springs are CO2-rich, alkaline-chloride to alkaline-carbonate waters, with elevated trace metal contents including Fe, Cu, As, Zn, Sb, and Tl. Notably, As contents are ≤11 ppm, indicating that thermal waters may be adversely impacting local water quality. Water δ18O and δD, trends in elemental chemistry, and cation geothermometry collectively demonstrate mixing of hot (200-260 °C) saline fluid with cold meteoric recharge along the fault. Helium isotope ratios (3He/4He) for dissolved gases in the hot springs range from 0.62 to 1.98 RC/RA, indicating the presence of ~25% mantle-derived helium, assuming mixing of an asthenospheric end-member with the crustal helium reservoir. CO2/3He and carbon stable isotope ratios indicate a carbon source derived from mixing of crustal sources with minor mantle carbon. Overall, the volatile signature overlaps with orogen-wide datasets where crustal overprinting has modified mantle contributions at active arc volcanoes. Given the long duration since active magmatism in the Cordillera

  1. Investigation of environmental pollution effects on stone monuments in the case of Santa Maria La Blanca, Seville (Spain)

    NASA Astrophysics Data System (ADS)

    Ortiz, P.; Vázquez, M. A.; Ortiz, R.; Martin, J. M.; Ctvrtnickova, T.; Mateo, M. P.; Nicolas, G.

    2010-09-01

    The aim of the study was to characterize specimens submitted to the effects of weathering in an urban atmosphere. Samples investigated were stones covered by crusts and deposits of thickness ranging from micrometers to millimetres due to traffic pollutants and mineral dust. The pieces were collected in the Church of Santa Maria La Blanca in Seville (South Spain). In the Historical Centre of this city, the traffic is the main source of sulphur oxides. Several analytical techniques have been employed to determine composition of specimens: OM, XRD, XRF, SEM-EDX and LIBS. The main weathering form was gypsum (CaSO4ṡ2H2O), and it has its source in sulphur oxides from traffic. Over this alteration layer, the deposits of atmospheric particles have been found. According to LIBS results, these particles can be composed of Al, Si, Ba, K, Na, Ti, V, Mg and Ca, while XRF technique also detect S, Fe, Mn and P. These atmospheric particles can have an anthropogenic or terrigenous origin, including the weathering of the building materials and its restoration products.

  2. PHASE ANALYSES OF URANIUM-BEARING MINERALS FROM THE HIGH GRADE ORE, NOPAL I, PENA BLANCA, MEXICO

    SciTech Connect

    M. Ren; P. Goodell; A. Kelts; E.Y. Anthony; M. Fayek; C. Fan; C. Beshears

    2005-07-11

    The Nopal I uranium deposit is located in the Pena Blanca district, approximately 40 miles north of Chihuahua City, Mexico. The deposit was formed by hydrothermal processes within the fracture zone of welded silicic volcanic tuff. The ages of volcanic formations are between 35 to 44 m.y. and there was secondary silicification of most of the formations. After the formation of at least part of the uranium deposit, the ore body was uplifted above the water table and is presently exposed at the surface. Detailed petrographic characterization, electron microprobe backscatter electron (BSE) imagery, and selected x-ray maps for the samples from Nopal I high-grade ore document different uranium phases in the ore. There are at least two stages of uranium precipitation. A small amount of uraninite is encapsulated in silica. Hexavalent uranium may also have been a primary precipitant. The uranium phases were precipitated along cleavages of feldspars, and along fractures in the tuff. Energy dispersive spectrometer data and x-ray maps suggest that the major uranium phases are uranophane and weeksite. Substitutions of Ca and K occur in both phases, implying that conditions were variable during the mineralization/alteration process, and that compositions of the original minerals have a major influence on later stage alteration. Continued study is needed to fully characterize uranium behavior in these semi-arid to arid conditions.

  3. Microplankton dynamics under heavy anthropogenic pressure. The case of the Bahía Blanca Estuary, southwestern Atlantic Ocean.

    PubMed

    López Abbate, M Celeste; Molinero, Juan Carlos; Guinder, Valeria A; Dutto, M Sofía; Barría de Cao, M Sonia; Ruiz Etcheverry, Laura A; Pettigrosso, Rosa E; Carcedo, M Cecilia; Hoffmeyer, Mónica S

    2015-06-15

    Quantifying biotic feedbacks in response to environmental signals is fundamental to assess ecosystem perturbation. We analyzed the joint effects of eutrophication, derived from sewage pollution, and climate at the base of the pelagic food web in the Bahía Blanca Estuary (SW Atlantic Ocean). A two-year survey of environmental conditions and microplankton communities was conducted in two sites affected by contrasting anthropogenic eutrophication conditions. Under severe eutrophication, we found higher phytoplankton abundance consistently dominated by smaller sized, non siliceous species, while microzooplankton abundance remained lower and nutrient stoichiometry showed conspicuous deviations from the Redfield ratio. Phytoplankton growth in such conditions appeared controlled by phosphorous. In turn, microplankton biomass and phytoplankton size ratio (<20μm:>20μm) displayed a saturation relationship with nutrients in the highly eutrophic area, although mean phytoplankton growth was similar in both eutrophic systems. The strength of links within the estuarine network, quantified through path analysis, showed enhanced relationships under larger anthropogenic eutrophication, which fostered the climate influence on microplankton communities. Our results show conspicuous effects of severe sewage pollution on the ecological stoichiometry, i.e., N and P excess with respect to Si, altering nutrient ratios for microplankton communities. This warns on wide consequences on food web dynamics and ultimately in ecosystem assets of coastal pelagic environments. PMID:25837775

  4. Analysis of 15 autosomal STR loci from Mar del Plata and Bahia Blanca (Central Region of Argentina).

    PubMed

    Parolin, María Laura; Carreras-Torres, Robert; Sambuco, Lorena Andrea; Jaureguiberry, Stella Maris; Iudica, Celia Estela

    2014-05-01

    Allele frequencies for the 15 short tandem repeats (STRs) loci included in the AmpFlSTR® Identifiler kit were estimated in a sample of unrelated individuals from Mar del Plata (MDQ; N = 180) and Bahia Blanca (BB; N = 85) (Buenos Aires, Argentina). Biological samples were obtained from voluntary donors and forensic cases. Both populations were in Hardy-Weinberg equilibrium after Bonferroni correction, except for locus vWA in MDQ and D2S1338 in BB. FGA was the most informative locus, and the least discriminating locus was TPOX in both samples. The combined power of discrimination (PDc) and the combined probability of exclusion (PEc) were similar in MDQ and BB samples (0.999999998 < PDc < 0.999999999 and 0.999999979 < PEc < 0.999999989). The multidimentional scaling plot from Rst genetic distance matrix and the interethnic admixture estimation supported a higher European contribution in populations of the central region compared with populations from other regions of Argentina with higher Amerindian composition. These results enlarge the Argentine databases of autosomal STR loci, revealed as an excellent tool for human identification tests and population genetic analysis. PMID:24257759

  5. The Point Sal–Point Piedras Blancas correlation and the problem of slip on the San Gregorio–Hosgri fault, central California Coast Ranges

    USGS Publications Warehouse

    Colgan, Joseph P.; Stanley, Richard G.

    2016-01-01

    Existing models for large-magnitude, right-lateral slip on the San Gregorio–Hosgri fault system imply much more deformation of the onshore block in the Santa Maria basin than is supported by geologic data. This problem is resolved by a model in which dextral slip on this fault system increases gradually from 0–10 km near Point Arguello to ∼150 km at Cape San Martin, but such a model requires abandoning the cross-fault tie between Point Sal and Point Piedras Blancas, which requires 90–100 km of right-lateral slip on the southern Hosgri fault. We collected stratigraphic and detrital zircon data from Miocene clastic rocks overlying Jurassic basement at both localities to determine if either section contained unique characteristics that could establish how far apart they were in the early Miocene. Our data indicate that these basins formed in the early Miocene during a period of widespread transtensional basin formation in the central Coast Ranges, and they filled with sediment derived from nearby pre-Cenozoic basement rocks. Although detrital zircon data do not indicate a unique source component in either section, they establish the maximum depositional age of the previously undated Point Piedras Blancas section to be 18 Ma. We also show that detrital zircon trace-element data can be used to discriminate between zircons of oceanic crust and arc affinity of the same age, a potentially useful tool in future studies of the California Coast Ranges. Overall, we find no characteristics in the stratigraphy and provenance of the Point Sal and Point Piedras Blancas sections that are sufficiently unique to prove whether they were far apart or close together in the early Miocene, making them of questionable utility as piercing points.

  6. Assessing the variability of glacier lake bathymetries and potential peak discharge based on large-scale measurements in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Cochachin, Alejo; Huggel, Christian; Salazar, Cesar; Haeberli, Wilfried; Frey, Holger

    2015-04-01

    Over timescales of hundreds to thousands of years ice masses in mountains produced erosion in bedrock and subglacial sediment, including the formation of overdeepenings and large moraine dams that now serve as basins for glacial lakes. Satellite based studies found a total of 8355 glacial lakes in Peru, whereof 830 lakes were observed in the Cordillera Blanca. Some of them have caused major disasters due to glacial lake outburst floods in the past decades. On the other hand, in view of shrinking glaciers, changing water resources, and formation of new lakes, glacial lakes could have a function as water reservoirs in the future. Here we present unprecedented bathymetric studies of 124 glacial lakes in the Cordillera Blanca, Huallanca, Huayhuash and Raura in the regions of Ancash, Huanuco and Lima. Measurements were carried out using a boat equipped with GPS, a total station and an echo sounder to measure the depth of the lakes. Autocad Civil 3D Land and ArcGIS were used to process the data and generate digital topographies of the lake bathymetries, and analyze parameters such as lake area, length and width, and depth and volume. Based on that, we calculated empirical equations for mean depth as related to (1) area, (2) maximum length, and (3) maximum width. We then applied these three equations to all 830 glacial lakes of the Cordillera Blanca to estimate their volumes. Eventually we used three relations from the literature to assess the peak discharge of potential lake outburst floods, based on lake volumes, resulting in 3 x 3 peak discharge estimates. In terms of lake topography and geomorphology results indicate that the maximum depth is located in the center part for bedrock lakes, and in the back part for lakes in moraine material. Best correlations are found for mean depth and maximum width, however, all three empirical relations show a large spread, reflecting the wide range of natural lake bathymetries. Volumes of the 124 lakes with bathymetries amount to 0

  7. Testing Pixel Translation Digital Elevation Models to Reconstruct Slip Histories: An Example from the Agua Blanca Fault, Baja California, Mexico

    NASA Astrophysics Data System (ADS)

    Wilson, J.; Wetmore, P. H.; Malservisi, R.; Ferwerda, B. P.; Teran, O.

    2012-12-01

    We use recently collected slip vector and total offset data from the Agua Blanca fault (ABF) to constrain a pixel translation digital elevation model (DEM) to reconstruct the slip history of this fault. This model was constructed using a Perl script that reads a DEM file (Easting, Northing, Elevation) and a configuration file with coordinates that define the boundary of each fault segment. A pixel translation vector is defined as a magnitude of lateral offset in an azimuthal direction. The program translates pixels north of the fault and prints their pre-faulting position to a new DEM file that can be gridded and displayed. This analysis, where multiple DEMs are created with different translation vectors, allows us to identify areas of transtension or transpression while seeing the topographic expression in these areas. The benefit of this technique, in contrast to a simple block model, is that the DEM gives us a valuable graphic which can be used to pose new research questions. We have found that many topographic features correlate across the fault, i.e. valleys and ridges, which likely have implications for the age of the ABF, long term landscape evolution rates, and potentially provide conformation for total slip assessments The ABF of northern Baja California, Mexico is an active, dextral strike slip fault that transfers Pacific-North American plate boundary strain out of the Gulf of California and around the "Big Bend" of the San Andreas Fault. Total displacement on the ABF in the central and eastern parts of the fault is 10 +/- 2 km based on offset Early-Cretaceous features such as terrane boundaries and intrusive bodies (plutons and dike swarms). Where the fault bifurcates to the west, the northern strand (northern Agua Blanca fault or NABF) is constrained to 7 +/- 1 km. We have not yet identified piercing points on the southern strand, the Santo Tomas fault (STF), but displacement is inferred to be ~4 km assuming that the sum of slip on the NABF and STF is

  8. Investigating potential precipitation changes with impacts on small-scale farming in mountain villages, Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Gurgiser, Wolfgang; Hofer, Marlis; Juen, Irmgard; Schauwecker, Simone; Singer, Katrin; Neuburger, Martina; Kaser, Georg

    2015-04-01

    Small subsistence farmers on the slopes above the city of Huaraz in the Peruvian Cordillera Blanca assign recent challenges in agricultural production - beyond other factors - to decreasing precipitation during the early crop cultivation period in August and September. In general, local climate is characterized by low annual variation in air temperature but a strong seasonality in precipitation. While driest conditions prevail in June and July, precipitation increases gradually towards the October to April wet season with strong topographically induced gradients. Because seeding occurs soon after the core dry months, cultivation is highly vulnerable to potential alterations in the transition period from dry to wet conditions. Within this study we try to find "data-based" evidence for changes in precipitation patterns, even though the availability of meteorological information for proving precipitation trends is generally poor for this region. We currently investigate the respective potential of connecting approx. 10 years (2003-2013) of ground measurements (weekly resolution with some gaps) with ERA-interim total precipitation output (0.75 deg. resolution) by (1) selecting those adjacent model grid points that explain measured precipitation variability best and by (2) fitting the data from the selected grid points to the measurements with quantile mapping. Uncertainties arising from the transfer functions are assessed with a cross validation approach. Our preliminary results suggest that (1) ground measurements are fairly explained by ERA interim data (despite the very complex topography), that (2) no significant trends in precipitation at the end of the dry season (August, September) are detectable for the period 1979-2013, but relatively high year-to-year variability occurs and that (3) process based limited area modeling might be required to effectively assess specific requests of user groups related to local precipitation variability.

  9. Time-lapse and UAV Thermal Imaging of Glacial and Periglacial Environments in the Peruvian Andes (Cordillera Blanca, Peru)

    NASA Astrophysics Data System (ADS)

    McKenzie, J. M.; Wigmore, O.; Aubry-Wake, C.; Mark, B. G.; Hellstrom, R. A.; Lautz, L.

    2015-12-01

    In the tropics, the acquisition of high-resolution geospatial data of high-mountain glacial and periglacial systems presents unique challenges due to remote site access and very high elevations. For glaciers and hydrologic systems, a key variable of interest is surface temperature as it constrains glacier melt rates, traces hydrologic processes, and is needed for the calibration of energy budget models. We present results from two studies that acquired high resolution temperature data from the Cuchillacocha Glacier, Peru (9.24°S, 77.21°W). The glacier resides on the western drainage of the Cordillera Blanca with an elevation range of 4700 to 6096 m. In the first study we use high resolution time-lapse infrared imagery (5-10 minute interval over 3 days; 0.6 m2 pixel size) to observe diel changes in the surface energy budget of the glacier and to demonstrate how radiation from bare rock adjacent to the glacier may affect melt rates. In the second study we use a newly developed, inexpensive unmanned aerial vehicle (UAV) for high resolution multispectral mapping of the glacier (2 cm resolution orthomosaic and 5 cm resolution DEM). We present results showing how the time-lapse and the high-resolution UAV imagery can be combined to further strengthen our understanding of the Cuchillacocha Glacier's energy budget and possible insights about turbulent heat fluxes. While the new instruments provide unprecedented data acquisition capabilities, there is an outstanding need for proper data correction. Spatial/thermal control points and post-processing algorithms are needed to produce quantifiable datasets. For example, our post-processed time-lapse imagery has an r2 > 0.9 after emissivity, transmissivity and offset corrections.

  10. VIEW OF PIEDMONT AVENUE AT INTERSECTION OF DURANT STREET. SEEN ...

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

    VIEW OF PIEDMONT AVENUE AT INTERSECTION OF DURANT STREET. SEEN FROM NW CORNER LOOKING SE. Photograph by Brian Grogan, July 8, 2007 - Piedmont Way & the Berkeley Property Tract, East of College Avenue between Dwight Way & U.C. Memorial Stadium, Berkeley, Alameda County, CA

  11. VIEW OF PIEDMONT AVENUE AT INTERSECTION OF DURANT AVENUE WITH ...

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

    VIEW OF PIEDMONT AVENUE AT INTERSECTION OF DURANT AVENUE WITH DOME OF THE INTERNATIONAL HOUSE AT 2299 PIEDMONT AVENUE. BY GEORGE W. KELHAM, 1929, SEEN FROM SW CORNER LOOKING NORTH. Photograph by Fredrica Drotos and Michael Kelly, July 9, 2006 - Piedmont Way & the Berkeley Property Tract, East of College Avenue between Dwight Way & U.C. Memorial Stadium, Berkeley, Alameda County, CA

  12. VIEW OF PIEDMONT AVENUE BETWEEN CHANNING WAY AND DURANT AVENUE. ...

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

    VIEW OF PIEDMONT AVENUE BETWEEN CHANNING WAY AND DURANT AVENUE. 2325 PIEDMONT (MRS. F.W. FISH HOUSE DESIGNED BY CHARLES S. KAISER, 1910. SEEN FROM WEST SIDE OF PIEDMONT LOOKING NORTH. Photograph by Fredrica Drotos and Michael Kelly, July 9, 2006 - Piedmont Way & the Berkeley Property Tract, East of College Avenue between Dwight Way & U.C. Memorial Stadium, Berkeley, Alameda County, CA

  13. VIEW OF PIEDMONT AVENUE AT INTERSECTION OF DURANT AVENUE. SEEN ...

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

    VIEW OF PIEDMONT AVENUE AT INTERSECTION OF DURANT AVENUE. SEEN FROM NW CORNER LOOKING SE. Photograph by Brian Grogan, July 8, 2007 - Piedmont Way & the Berkeley Property Tract, East of College Avenue between Dwight Way & U.C. Memorial Stadium, Berkeley, Alameda County, CA

  14. VIEW OF PIEDMONT AVENUE BETWEEN CHANNING WAY AND DURANT AVENUE. ...

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

    VIEW OF PIEDMONT AVENUE BETWEEN CHANNING WAY AND DURANT AVENUE. SEEN FROM WEST SIDE OF PIEDMONT LOOKING NORTH. Photograph by Brian Grogan, July 2007 - Piedmont Way & the Berkeley Property Tract, East of College Avenue between Dwight Way & U.C. Memorial Stadium, Berkeley, Alameda County, CA

  15. Cuidados paliativos durante el cáncer

    Cancer.gov

    Describe la función de los cuidados paliativos, los cuales son los cuidados que se brindan a pacientes que tienen una enfermedad grave o potencialmente letal, como el cáncer, desde el momento del diagnóstico y durante todo el curso de la enfermedad.

  16. Spatio-temporal assessment of WRF, TRMM and in situ precipitation data in a tropical mountain environment (Cordillera Blanca, Peru)

    NASA Astrophysics Data System (ADS)

    Mourre, L.; Condom, T.; Junquas, C.; Lebel, T.; Sicart, J. E.; Figueroa, R.; Cochachin, A.

    2015-07-01

    The estimation of precipitation over the broad range of scales of interest for climatologists, meteorologists and hydrologists is challenging in high altitudes of tropical regions, where the spatial variability of precipitation is important while in situ measurements remain scarce largely due to operational constraints. Three different types of rainfall products - ground based, satellite derived, RCM outputs - are compared here during the hydrological year 2012/13 in order to retrieve rainfall patterns at time scales ranging from sub-daily to annual over a watershed of approximately 10 000 km2 in Peru. It is a high altitude catchment, located in the region of the Cordillera Blanca, with 41 % of its area above 4000 m a.s.l. and 340 km2 glaciated. Daily in situ data are interpolated using a kriging with external drift (KED) algorithm; the satellite product is TRMM 3B42, which incorporates monthly gauge data; RCM outputs are obtained from WRF run with a Thompson microphysical scheme at three nested resolutions: 27, 9 and 3 km. The performances of each product are assessed from a double perspective. A local comparison with gauge data is first carried out when relevant (diurnal and seasonal cycles, statistics of rainfall occurrence); then the ability of each product to reproduce some well-known spatial features of rain fields at various time scales (from annual down to daily) is analysed. WRF simulations largely overestimate the annual totals, especially at low spatial resolution, while reproducing correctly the diurnal cycle and locating the spots of heavy rainfall more realistically than either the ground-based KED or the TRMM products. The main weakness of the KED data is the production of annual rainfall maxima over the summit rather than on the slopes, induced by a lack of in situ data above 3800 m a.s.l. One main limitation of the TRMM product is its poor performance over ice-covered areas because ice on the ground behaves in a similar way as rain or ice drops in

  17. Modelling cascading and erosional processes for glacial lake outburst floods in the Quillcay catchment, Huaraz, Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Baer, Patrick; Huggel, Christian; Frey, Holger; Chisolm, Rachel; McKinney, Daene; McArdell, Brian; Portocarrero, Cesar; Cochachin, Alejo

    2016-04-01

    Huaraz as the largest city in Cordillera Blanca has faced a major disaster in 1941, when an outburst flood from Lake Palcacocha killed several thousand people and caused widespread destruction. Recent studies on glacial lake outburst flood (GLOF) modelling and early warning systems focussed on Lake Palcacocha which has regrown after the 1941 event, from a volume of half a million m3 in 1974 to a total volume of more than 17 million m3 today. However, little research has been conducted so far concerning the situation of other lakes in the Quillcay catchment, namely Lake Tullparaju (12 mill. m3) and Cuchillacocha (2.5 mill. m3), which both also pose a threat to the city of Huaraz. In this study, we modelled the cascading processes at Lake Tullparaju and Lake Cuchillacocha including rock/ice avalanches, flood wave propagation in the lake and the resulting outburst flood and debris flows. We used the 2D model RAMMS to simulate ice avalanches. Model output was used as input for analytical 2D and 3D calculations of impact waves in the lakes that allowed us to estimate dam overtopping wave height. Since the dimension of the hanging glaciers above all three lakes is comparable, the scenarios in this study have been defined similar to the previous study at Lake Palcacocha. The flow propagation model included sediment entrainment in the steeper parts of the catchment, adding up to 50% to the initial flow volume. The results for total travel time as well as for inundated areas and flow depth and velocity in the city of Huaraz are comparable to the previous studies at Lake Palcacocha. This underlines the importance of considering also these lakes within an integral hazard analysis for the city of Huaraz. A main challenge for modelling GLOFs in the Quillcay catchment using RAMMS is the long runout distance of over 22 km combined with the very low slope gradient of the river. Further studies could improve the process understanding and could focus on more detailed investigations

  18. Temporal variation in abundance and fecundity of the invading copepod Eurytemora americana in Bahía Blanca Estuary during an unusual year

    NASA Astrophysics Data System (ADS)

    Berasategui, Anabela A.; Hoffmeyer, Mónica S.; Biancalana, Florencia; Fernandez Severini, Melisa; Menendez, María C.

    2009-10-01

    Eurytemora americana has been only reported as invader in Bahía Blanca Estuary, Argentina within the South Hemisphere. There are a few experimental researches under laboratory conditions done with this species and its reproductive behaviour around the world is very scarce. Consequently, it is still not possible to completely understand its population dynamics. In the present study, E. americana reproductive temporal behaviour and relationships among abundance, female size, egg production and hatching success were examined in the Bahía Blanca Estuary, during 2007 pulse. In order to determine the potential relationships between these variables and the environmental variables, experimental incubations were conducted in the laboratory simulating natural conditions. Spearman's rank correlation was used to analyze the relationships among all variables. Temporal change of biotic and environmental variables was corroborated by a Mann-Whitney/Kruskal-Wallis non-parametric tests, with significant differences ( p ≪ 0.01) in all variables throughout the study. Abundance population results showed very high values in relation to those recorded in recent years in Bahía Blanca Estuary. This response could be due to the unusual combination of environmental factors (polar wave with temperatures ≤6 °C and a drought period with high salinities, 32.7-36.6) recorded during the studied winter period. Significant positive correlations between abundance and salinity ( p < 0.01, n = 226), and hatching success ( p < 0.01, n = 25) as well as a significant negative correlation between abundance and chlorophyll a ( p < 0.01, n = 226) were found. Although E. americana shows a k-strategy within its annual pulse, it presented two markedly distinct behaviours depending on temporal environmental variability. From July to early september, when the estuary evidenced high salinity, low temperature and high food availability, E. Americana showed large females, large clutch size and high hatching

  19. Spatiotemporal variability and differentiation between anthropogenic and natural contamination of heavy metals of surface water: a case study in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Guittard, A.; Baraer, M.; McKenzie, J. M.; Mark, B. G.; Fernandez, A.; Walsh, E.; Santos Perez, A.

    2015-12-01

    The Rio Santa, Peru, drains the western slopes of the glacierized Cordillera Blanca and provides water resources at almost all levels of the watershed. As it flows away from the valleys of the Cordillera Blanca, the Rio Santa takes out pollution from numerous sources, including acid mine drainage and natural sulfide oxidation by-products. The Rio Santa dry season discharge decline that is projected to be a consequence of glaciers retreat will probably have implications for the evolution of water pollution. This threat makes the characterization of the actual contamination mechanisms of primary importance. The present study focuses, first, on the spatiotemporal variability of heavy metal contamination across the entire Rio Santa Watershed and secondly on differentiating anthropogenic and natural contaminated sites. First, a macroscale sampling has been done during the summer 2013 to provide an overview of the contamination by trace metal, in water, suspended sediments and riverbed sediments. In addition, 30 water samples were taken from a point next to the city of Huaraz at a frequency of once every 2 weeks and analyzed for trace metals. Secondly, in order to identify hydrochemical contaminant origin dependant signatures in the Rio Santa watershed, 5 areas of known contamination origins were sampled during the summer 2014.Spatially speaking, we observed that most pollution is located in the south of the watershed, and that a large part of the arsenic that reaches the Santa in an aqueous phase does not make it to the outlet but remains trapped in the riverbed. Annual variation in water shows a very unusual fluctuation in Mn compare to other trace metal which are relatively stable. By differencing anthropogenic and natural sites and by considering glaciers melt and decrease water in future what would be the impact of the part of natural contaminated sites versus anthropogenic, mining and cities, on the water quality? Preliminary results show that anthropogenic sites

  20. Reducing risks from hazardous glacier lakes in the Cordillera Blanca (Peru): Six decades of experience and perspectives for the future

    NASA Astrophysics Data System (ADS)

    Portocarrero, Cesar; Cochachin, Alejo; Frey, Holger; González, Cesar; Haeberli, Wilfried; Huggel, Christian

    2016-04-01

    Outbursts from glacier lakes at various spatial and temporal scales have had marked geomorphological effects in many mountain ranges. In many glacierized Andean mountain regions substrates of human settlements made out of flood and debris-flow deposits are testimonies of such events. Examples in the Cordillera Blanca, Peru, are the towns of Caraz, Carhuaz or parts of Huaraz. Continued glacier shrinking since the end of the Little Ice Age caused the formation or enlargement of numerous lakes. The outburst of Laguna Palcacocha, destroying the centre of Huaraz and causing more than 1800 losses of life in December 1941, marked the beginning of systematic risk reduction work in Peru. Corresponding efforts included glacier and lake inventories, hazard assessments, definition of high-risk situations, and completion of engineering work for lake-level lowering in more than 30 cases. The latter comprises outlet reinforcements on morainic dams as well as artificial tunnels in bedrock thresholds. This work has been remarkably efficient as documented in the latest case of the Laguna Huallcacocha (Carhuaz-Ancash), where the earlier made installations withstood the erosive power of an impact wave from an ice avalanche in 2015. In the case of the Laguna 513, the impact wave and far-reaching flood caused by a rock/ice avalanche from Nevado Hualcán in April 2010 showed that the risk had been essentially reduced by the preventive lake-level lowering in the early 1990s but not to zero. Risk assessments, planning, construction and non-structural risk reduction efforts continue. Work is in progress to increase the safety of Laguna Palcacocha where extensive assessments and model calculations had been carried out. Risks related to rock/ice avalanches into lakes from steep icy slopes and related to de-buttressing processes as well as long-term permafrost degradation increases. Based on morphological indications and numerical modelling (GlabTop) an inventory of possible future lakes

  1. Constraining Basin Geometry and Fault Kinematics on the Santo Tomas Segment of the Agua Blanca Fault Through a Combined Geophysical and Structural Study

    NASA Astrophysics Data System (ADS)

    Springer, A.; Wetmore, P.; Fletcher, J.; Connor, C. B.; Callihan, S.; Beeson, J.; Wilson, J.

    2008-12-01

    The Santo Tomas basin, located in northern Baja California, formed at a right step in the dextral Agua Blanca fault (ABF). The ABF extends for more than 120km east from Punta Banda, with an east-west strike, and represents the southernmost fault in the San Andreas system of faulting. The basin is located roughly 40km south of Ensenada where the Agua Blanca fault intersects the Maximos fault. A detailed geophysical analysis defines the basin geometry, and helps to constrain the distribution and offset of mapped and concealed faults. Geophysical and structural data sets are combined to constrain the kinematic evolution of the Santo Tomas basin, including determining the relative amount of dip-slip and strike-slip motion on basin-bounding faults. Gravity data was collected over seven transects across and along the axis of the basin at 500 meter intervals, with 200 meter intervals at locations of known or inferred faults. Magnetic data were taken over the same lines, and are used in conjunction with gravity data to constrain the locations, geometries and displacements of intrabasinal faults. The combined gravity and magnetic data are modeled using Geosoft Oasis montaj software to create 2 3/4D models along profiles across the study area. Modeling of the geophysical data combined with structural mapping indicates that the Santo Tomas basin is bound by two major strike-slip faults, the ABF on the northeastern side and the Maximos fault on south, Based on offset markers, most of the strike-slip motion appears to be concentrated on the ABF on the north side of the basin. The ABF fault is characterized by multiple subparallel fault strands that appear to coalesce into single strands to the northwest and southeast of the basin. The Maximos is characterized by a single strand throughout the basin and it exhibits a minor dip-slip component. Basin sediments thicken slightly against the Maximos fault to as much as 1km. A third fault, cutting across the basin southeast of the

  2. Tropical glacier fluctuations in the Cordillera Blanca, Peru between 12.5 and 7.6 ka from cosmogenic 10Be dating

    NASA Astrophysics Data System (ADS)

    Glasser, Neil F.; Clemmens, Samuel; Schnabel, Christoph; Fenton, Cassandra R.; McHargue, Lanny

    2009-12-01

    We report cosmogenic surface exposure 10Be ages of 21 boulders on moraines in the Jeullesh and Tuco Valleys, Cordillera Blanca, Peru (˜10°S at altitudes above 4200 m). Ages are based on the sea-level at high-latitude reference production rate and scaling system of Lifton et al. (2005. Addressing solar modulation and long-term uncertainties in scaling secondary cosmic rays for in situ cosmogenic nuclide applications. Earth and Planetary Science Letters 239, 140-161) in the CRONUS-Earth online calculator of Balco et al. (2008. A complete and easily accessible means of calculating surface exposure ages or erosion rates from 10Be and 26Al measurements. Quaternary Geochronology 3, 174-195). Using the Lifton system, large outer lateral moraines in the Jeullesh Valley have a 10Be exposure age of 12.4 ka, inside of which are smaller moraine systems dated to 10.8, 9.7 and 7.6 ka. Large outer lateral moraines in the Tuco Valley have a 10Be exposure age of 12.5 ka, with inner moraines dated to 11.3 and 10.7 ka. Collectively, these data indicate that glacier recession from the Last Glacial Maximum (LGM) in the Cordillera Blanca was punctuated by three to four stillstands or minor advances during the period 12.5-7.6 ka, spanning the Younger Dryas Chronozone (YDC; ˜12.9-11.6 ka) and the cold event identified in Greenland ice cores and many other parts of the world at 8.2 ka. The inferred fluctuations of tropical glaciers at these times, well after their withdrawal from the LGM, indicate an increase in precipitation or a decrease in temperature in this region. Although palaeoenvironmental records show regional and temporal variability, comparison with proxy records (lacustrine sediments and ice cores) indicate that regionally this was a cold, dry period so we ascribe these glacier advances to reduced atmospheric temperature rather than increased precipitation.

  3. Polycyclic aromatic hydrocarbons in water, mussels ( Brachidontes sp., Tagelus sp.) and fish ( Odontesthes sp.) from Bahía Blanca Estuary, Argentina

    NASA Astrophysics Data System (ADS)

    Arias, Andres H.; Spetter, Carla V.; Freije, Rubén H.; Marcovecchio, Jorge E.

    2009-10-01

    Polycyclic aromatic hydrocarbons (PAHs), one of the major groups of anthropogenic environmental pollutants, were firstly identified and measured in coastal waters, native mussels and fish of an industrialized South American estuary. The aim of this study was to measure the PAHs concentrations and evaluate distribution and sources in surface seawater, native mussels ( Brachidontes sp. and Tagelus sp.) and fish ( Odontesthes sp.) from various coastal sites of the Bahía Blanca Estuary, in order to put the estuary in a global context and assess it ecotoxicological risk. For this, 40 samples of surface water were collected between August 2004 and February 2006 and analyzed by GC/MS for 17 PAHs, including the 16 EPA priority PAHs. In addition, main physicochemical parameters, nutrients and pigments were simultaneously obtained as key parameters to evaluate possible relationships. Finally, several native mussel communities and fish specimens were also analyzed for PAHs contents. The area of study is located at the Argentinean coast and presents an intensive human and industrial activity at the north shoreline. Total PAHs (Σ17 PAHs) in whole surface waters ranged from undetected to more than 4 μg/l. Seasonal PAHs levels relationship with master parameters suggested a relationship between the phytoplankton microbiological cycling and the dissolved/suspended PAHs occurrence in water. In addition, Cluster Analysis was performed to identify the homogeneous groups of individual PAHs in water and Principal Component Analysis to extract underlying common factors. The result of PCA was similar to that of the cluster analysis; both could differentiate two subsets of pyrogenic sources and a petrogenic origin. PAHs levels in indigenous mussels ( Brachidontes sp. and Tagelus sp.) ranged from 348 to 1597 ng/g (dry weight). Fish specimens ( Odontesthes sp.) showed a mean concentration of 1095 ng/g d.w. in whole tissues. Mussel source ratios and PCA results were in good agreement with

  4. Land cover changes in tidal salt marshes of the Bahía Blanca estuary (Argentina) during the past 40 years

    NASA Astrophysics Data System (ADS)

    Pratolongo, Paula; Mazzon, Carla; Zapperi, Georgina; Piovan, María Julia; Brinson, Mark M.

    2013-11-01

    The present work describes land cover changes in the inner section of Canal Principal, in the Bahía Blanca estuary. The study area is subjected to a rising relative sea level, large interanual variations in rainfall, and recent changes human in land use. We used historical aerial photographs, high resolution satellite images, and GIS to quantify changes in land cover for the years 1967, 1996, and 2005. The replacement of Sarcocornia perennis marshes and halophytic shrub-like steppes by mudflats is a recurring pattern through the area. We estimated a total loss to mudflats of 33 and 6% of the area of marshes and steppes, respectively, and it may reflect increased erosion of relict Holocene coastal terraces in response to a rising sea level. Human activities have played a significant role in reshaping coastal landscape, particularly in the harbor area. Fifty percent of the area originally covered by shrub-like steppes and 33% of the Sarcocornia perennis marshes were replaced by human land uses. Major changes correspond to dredged spoil deposition and landfilling. One of the most striking changes observed is the increase of the area covered by Spartina alterniflora marshes. This type of replacement suggests the occurrence of depositional environments that, at least locally, allow bed elevation and vegetation growth. In the harbor area, an enhanced sedimentation may result from maintenance dredging. At the mouth of Maldonado channel, sediment deposition may occur during extraordinary heavy rainfall associated to El Niño.

  5. A record of uranium-series transport at Nopal I, Sierra Pena Blanca, Mexico: Implications for natural uranium deposits and radioactive waste repositories

    DOE PAGESBeta

    Denton, J. S.; Goldstein, S. J.; Paviet, P.; Nunn, A. J.; Amato, R. S.; Hinrichs, K. A.

    2016-09-15

    Studies of uranium-series (U-series) disequilibria within and around ore deposits provide valuable information on the extent and timing of actinide mobility, via mineral-fluid interaction, over a range of spatial and temporal scales. Such information is useful in studies of analogs of high-level nuclear-waste repositories, as well as for mining and mineral extraction sites, locations of previous nuclear weapons testing, and legacy nuclear waste contamination. In this study we present isotope dilution mass spectrometry U-series measurements for fracture-fill materials (hematite, goethite, kaolinite, calcite, dolomite and quartz) from one such analog; the Nopal I uranium ore deposit situated at Peña Blanca inmore » the Chihuahua region of northern Mexico. The ore deposit is located in fractured, unsaturated volcanic tuff and fracture-fill materials from surface fractures as well as fractures in a vertical drill core have been analyzed. High uranium concentrations in the fracture-fill materials (between 12 and 7700 ppm) indicate uranium mobility and transport from the deposit. Furthermore, uranium concentrations generally decrease with horizontal distance away from the deposit but in this deposit there is no trend with depth below the surface.« less

  6. The NS3 protein of Rice hoja blanca tenuivirus suppresses RNA silencing in plant and insect hosts by efficiently binding both siRNAs and miRNAs

    PubMed Central

    Hemmes, Hans; Lakatos, Lóránt; Goldbach, Rob; Burgyán, József; Prins, Marcel

    2007-01-01

    RNA silencing plays a key role in antiviral defense as well as in developmental processes in plants and insects. Negative strand RNA viruses such as the plant virus Rice hoja blanca tenuivirus (RHBV) replicate in plants and in their insect transmission vector. Like most plant-infecting viruses, RHBV encodes an RNA silencing suppressor, the NS3 protein, and here it is demonstrated that this protein is capable of suppressing RNA silencing in both plants and insect cells. Biochemical analyses showed that NS3 efficiently binds siRNA as well as miRNA molecules. Binding of NS3 is greatly influenced by the size of small RNA molecules, as 21 nucleotide (nt) siRNA molecules are bound > 100 times more efficiently than 26 nt species. Competition assays suggest that the activity of NS3 is based on binding to siRNAs prior to strand separation during the assembly of the RNA-induced silencing complex. In addition, NS3 has a high affinity for miRNA/miRNA* duplexes, indicating that its activity might also interfere with miRNA-regulated gene expression in both insects and plants. PMID:17513697

  7. Insights from analyzing and modelling cascading multi-lake outburst flood events in the Santa Cruz Valley (Cordillera Blanca, Perú)

    NASA Astrophysics Data System (ADS)

    Emmer, Adam; Mergili, Martin; Juřicová, Anna; Cochachin, Alejo; Huggel, Christian

    2016-04-01

    Since the end of Little Ice Age, the Cordillera Blanca of Perú has experienced tens of lake outburst floods (LOFs), resulting in the loss of thousands of lives and significant material damages. Most commonly involving glacial lakes, such events are often directly or indirectly related to glacier retreat. Here we analyze an event on 8th February 2012 involving four lakes and affecting two valleys (Santa Cruz and Artizón) in the northern part of the Cordillera Blanca. Using the combination of field data, satellite images, digital elevation model (DEM) and GIS-based modelling approaches, the main objectives are: (i) to better understand complex multi-lake outburst flood and related foregoing and induced geomorphological processes; and (ii) to evaluate and discuss the suitability, potentials and limitations of the r.avaflow model for modelling such complex process chains. Analyzing field geomorphological evidence and remotely-sensed images, we reconstruct the event as follows: a landslide from the recently deglaciated left lateral moraine of Lake Artizón Alto (4 639 m a.s.l.), characterized by steep slopes and a height of more than 200 m produced a displacement wave which overtopped the bedrock dam of the lake. The resulting flood wave breached the dam of the downstream moraine-/landslide-dammed Lake Artizón Bajo (4 477 m a.s.l.), decreasing the lake level by 10 m and releasing 3 x 105 m3 of water. Significant amounts of material were eroded from the steeper parts of the Artizón Valley (mean slope >15°) and deposited further downstream in the flatter part of the Santa Cruz Valley (mean slope <2°; confluence of the two valleys at 3 985 m a.s.l.). The flood affected two debris cone-dammed lakes (Jatuncocha and Ichiccocha) in the Santa Cruz Valley. Some minor damages to the dam of Lake Jatuncocha were documented. Geomprohological evidence of the event was observed more than 20 km downstream from Lake Artizón Alto. The described multi-LOF event was employed as a

  8. Modeling non-steady state radioisotope transport in the vadose zone--A case study using uranium isotopes at Pena Blanca, Mexico

    SciTech Connect

    Ku, T. L.; Luo, S.; Goldstein, S. J.; Murrell, M. T.; Chu, W. L.; Dobson, P. F.

    2009-06-01

    Current models using U- and Th-series disequilibria to study radioisotope transport in groundwater systems mostly consider a steady-state situation. These models have limited applicability to the vadose zone (UZ) where the concentration and migratory behavior of radioisotopes in fluid are often transitory. We present here, as a first attempt of its kind, a model simulating the non-steady state, intermittent fluid transport in vadose layers. It provides quantitative constraints on in-situ migration of dissolved and colloidal radioisotopes in terms of retardation factor and rock-water interaction (or water transit) time. For uranium, the simulation predicts that intermittent flushing in the UZ leads to a linear relationship between reciprocal U concentration and {sup 234}U/{sup 238}U ratio in percolating waters, with the intercept and slope bearing information on the rates of dissolution and {alpha}-recoil of U isotopes, respectively. The general validity of the model appears to be borne out by the measurement of uranium isotopes in UZ waters collected at various times over a period during 1995-2006 from a site in the Pena Blanca mining district, Mexico, where the Nopal I uranium deposit is located. Enhanced {sup 234}U/{sup 238}U ratios in vadose-zone waters resulting from lengthened non-flushing time as prescribed by the model provide an interpretative basis for using {sup 234}U/{sup 238}U in cave calcites to reconstruct the regional changes in hydrology and climate. We also provide a theoretical account of the model's potential applications using radium isotopes.

  9. Bent glacier tongues: A new look at Lliboutry's model of the evolution of the crooked Jatunraju Glacier (Parón Valley, Cordillera Blanca, Perú)

    NASA Astrophysics Data System (ADS)

    Iturrizaga, Lasafam

    2013-09-01

    The article tackles the issue of which factors may influence the flow direction and morphological shape of glacier tongues terminating at tributary junctions to the main valley in high mountain landscapes. A very particular morphological form of a glacier tongue shows the Jatunraju Glacier in the Cordillera Blanca (Perú). It terminates in the superior Parón Valley with a prominent crooked form, embedded in a 250 m-high moraine pedestal. Lliboutry (1977) has explained the deviation of the Jatunraju Glacier tongue as a result of a proglacial lake outburst. Alternative hypothetical models on a general scale have been developed for the causes determining the morphological characteristics of glacier tongues. These are based on empirical field evidence from the Parón Valley and from glaciers located in other high mountain areas, in particular in the Himalaya Region, where glacier tongues in confluence settings are abundant. The comparative investigations demonstrate that the pronounced crooked form of the Jatunraju Glacier may not be the result of a single extreme event, but may have been produced as well by gradual processes. In a general context, the study shows that crooked glacier tongues are common landforms in other mountain regions and mainly intrinsic to debris-covered glaciers. The morphological evolution of glacier tongues may involve a polygenetic process pattern over a longer geological time period. Apart from the steepness of the valley gradient of the main valley, the former confluence from the source glacier with the main glacier during times of a more extensive glaciation is regarded as one of the dominating factors controlling the later evolution of glacier tongues in general ("inherited confluence model").

  10. Modeling non-steady state radioisotope transport in the vadose zone - A case study using uranium isotopes at Peña Blanca, Mexico

    NASA Astrophysics Data System (ADS)

    Ku, T. L.; Luo, S.; Goldstein, S. J.; Murrell, M. T.; Chu, W. L.; Dobson, P. F.

    2009-10-01

    Current models using U- and Th-series disequilibria to study radioisotope transport in groundwater systems mostly consider a steady-state situation. These models have limited applicability to the vadose zone (UZ) where the concentration and migratory behavior of radioisotopes in fluid are often transitory. We present here, as a first attempt of its kind, a model simulating the non-steady state, intermittent fluid transport in vadose layers. It provides quantitative constraints on in-situ migration of dissolved and colloidal radioisotopes in terms of retardation factor and rock-water interaction (or water transit) time. For uranium, the simulation predicts that intermittent flushing in the UZ leads to a linear relationship between reciprocal U concentration and 234U/ 238U ratio in percolating waters, with the intercept and slope bearing information on the rates of dissolution and α-recoil of U isotopes, respectively. The general validity of the model appears to be borne out by the measurement of uranium isotopes in UZ waters collected at various times over a period during 1995-2006 from a site in the Peña Blanca mining district, Mexico, where the Nopal I uranium deposit is located. Enhanced 234U/ 238U ratios in vadose-zone waters resulting from lengthened non-flushing time as prescribed by the model provide an interpretative basis for using 234U/ 238U in cave calcites to reconstruct the regional changes in hydrology and climate. We also provide a theoretical account of the model's potential applications using radium isotopes.

  11. Analysis of precipitation data from in situ and large-scale source in a tropical mountain environment. Study case of the Cordillera Blanca region, Peru.

    NASA Astrophysics Data System (ADS)

    Mourre, Lise; Junquas, Clémentine; Condom, Thomas; Lebel, Thierry

    2014-05-01

    The study area, the watershed of the Rio Santa in Peru, accuses a strong longitudinal climatic gradient, from the humid Amazonian lowlands to the drier Pacific coast, associated with an altitudinal gradient, with the highest point of the watershed at 6,768 meters asl. The Cordillera Blanca situated in this area, had more than 600 km² of glacier coverage at the end of the 20th century, with more than half that belongs to the watershed of the Rio Santa. The application of a hydrological model in this area requires the analysis and regionalization of precipitation, a key variable for the establishment of a water balance. In this context, different sources of precipitation data are useful in order to catch the spatial and temporal variability: in situ meteorological stations, TRMM 3B42 and 3B43 product satellite data and outputs of WRF model (Weather Research and Forecasting Model) at 3 km of spatial resolution. Precipitations are dependent on both the large-scale atmospheric circulation and local parameters such as topography or albedo. As all these variables cannot be properly taken into account in large scale models, it is important to evaluate the contribution of regional models in the analysis and the understanding of the spatial heterogeneity of precipitation across a watershed. To investigate the spatial and temporal variability of precipitations, two approaches have been adopted in this work. In a first approach the spatial repartition of precipitation is described from station data. The second approach is focused on the assessment of a high-scale regional climate model (WRF) and the TRMM satellite data to reproduce spatially and temporally in situ observed precipitations. This comparison was carried out for different time-scale variability: on a monthly time scale with the observation of the seasonal cycle, on the daily time scale to study the occurrence of precipitation, and finally with the hourly data to study the representation of diurnal cycle. First

  12. Uniform Distribution of Yttrium and Heavy Rare Earth Elements in Round Top Mountain Rhyolite Deposit , Sierra Blanca Texas, USA: Data, Significance, and Origin

    NASA Astrophysics Data System (ADS)

    Pingitore, N. E., Jr.; Clague, J. W.; Gorski, D.

    2014-12-01

    The Round Top Mountain peraluminous rhyolite, exposed at the surface in Sierra Blanca, Hudspeth County, west Texas, USA, is enriched in yttrium and heavy rare earth elements (YHREEs). Other potentially valuable elements in the deposit include Be, Li, U, Th, Sn, F, Nb, and Ta. Texas Rare Earth Resources Corp. proposes to extract the YHREEs from the host mineral variety yttrofluorite by inexpensive heap leaching with dilute sulfuric acid, which also releases some of the Be, Li, U, F, and Th from other soluble minor minerals. Data: Feldspars and quartz comprise 90-95% of the rhyolite, with pheonocrysts of up to 250 microns set in an aphanitic matrix that hosts the typically sub-micron target yttrofluorite. Reverse circulation cuttings from some 100 drill holes, two drill cores, and outcrop and trench observations suggest striking physical homogeneity through this billion-plus ton surface-exposed laccolith, about 1200 feet high and a mile in diameter (375 x 1600 m). Gray to pink, and other minor hues, color variation derives from magnetite—hematite redox reaction. Plots of Y, 13 REEs, U, Th, and Nb analyses from over 1500 samples collected from 64 drill holes (color codes in figure) exhibit remarkably little variation in the concentration of these elements with geographic position or depth within the laccolith. Importance: Uniform mineralization grades help insure against the mining production surprises often associated with vein deposits and heterogeneous open pit deposits. At Round Top, mine feedstock can be relatively constant over the life of the mine (multiple decades), so the mechanical mining process can be optimized early on and not need expensive alterations later. Likewise, the chemical and physical parameters of the heap leach can be perfected. The sensitive and expensive process of extraction of elements and element groups from the pregnant leach solution and purification also can be optimized. Origin: The remarkable homogeneity of the YHREE distribution

  13. Increased Concentrations of Short-Lived Decay-Series Radionuclides in Groundwaters Underneath the Nopal I Uranium Deposit at Pena Blanca, Mexico

    NASA Astrophysics Data System (ADS)

    Luo, S.; Ku, T.; Todd, V.; Murrell, M. T.; Dinsmoor, J. C.

    2007-05-01

    The Nopal I uranium ore deposit at Pena Blanca, Mexico, located at > 200 meters above the groundwater table, provides an ideal natural analog for quantifying the effectiveness of geological barrier for isolation of radioactive waste nuclides from reaching the human environments through ground water transport. To fulfill such natural analog studies, three wells (PB1, PB2, and PB3 respectively) were drilled at the site from the land surface down to the saturated groundwater zone and ground waters were collected from each of these wells through large- volume sampling/in-situ Mn-filter filtration for analyses of short-lived uranium/thorium-series radionuclides. Our measurements from PB1 show that the groundwater standing in the hole has much lower 222Rn activity than the freshly pumped groundwater. From this change in 222Rn activity, we estimate the residence time of groundwater in PB1 to be about 20 days. Our measurements also show that the activities of short-lived radioisotopes of Th (234Th), Ra (228Ra, 224Ra, 223Ra), Rn (222Rn), Pb (210Pb), and Po (210Po) in PB1, PB2, and PB3 are all significantly higher than those from the other wells near the Nopal I site. These high activities provide evidence for the enrichment of long-lived U and Ra isotopes in the groundwater as well as in the associated adsorbed phases on the fractured aquifer rocks underneath the ore deposit. Such enrichment suggests a rapid dissolution of U and Ra isotopes from the uranium ore deposit in the vadose zone and the subsequent migration to the groundwater underneath. A reactive transport model can be established to characterize the in-situ transport of radionuclides at the site. The observed change of 222Rn activity at PB1 also suggests that the measured high radioactivityies in ground waters from the site isare not an artifact of drilling operations. However, further studies are needed to assess if or to what extent the radionuclide migration is affected by the previous mining activities at

  14. Uranium-rich opal from the Nopal I uranium deposit, Peña Blanca, Mexico: Evidence for the uptake and retardation of radionuclides

    NASA Astrophysics Data System (ADS)

    Schindler, Michael; Fayek, Mostafa; Hawthorne, Frank C.

    2010-01-01

    The Nopal I uranium deposit of the Sierra Peña Blanca, Mexico, has been the focus of numerous studies because of its economic importance and its use as a natural analog for nuclear-waste disposal in volcanic tuff. Secondary uranyl minerals such as uranophane, Ca[(UO 2)(SiO 3OH)] 2(H 2O) 5, and weeksite, (K,Na) 2[(UO 2) 2(Si 5O 13)](H 2O) 3, occur in the vadose zone of the deposit and are overgrown by silica glaze. These glazes consist mainly of opal A, which contains small particles of uraninite, UO 2, and weeksite. Close to a fault between brecciated volcanic rocks and welded tuff, a greenish silica glaze coats the altered breccia. Yellow silica glazes from the center of the breccia pipe and from the high-grade pile coat uranyl-silicates, predominantly uranophane and weeksite. All silica glazes are strongly zoned with respect to U and Ca, and the distribution of these elements indicates curved features and spherical particles inside the coatings. The concentrations of U and Ca correlate in the different zones and both elements inversely correlate with the concentration of Si. Zones within the silica glazes contain U and Ca in a 1:1 ratio with maximum concentrations of 0.08 and 0.15 at.% for the greenish and yellow glazes, respectively, suggesting trapping of either Ca 1U 1-aqueous species or -particles in the colloidal silica. X-ray photoelectron spectroscopy (XPS), Fourier-transform infra-red spectroscopy (FTIR), and oxygen-isotope ratios measured by secondary-ion mass spectrometry (SIMS) indicate higher U 6+/U 4+ ratios, higher proportions of Si-OH groups and lower δ 18O values for the greenish silica glaze than for the yellow silica glaze. These differences in composition reflect increasing brecciation, porosity, and permeability from the center of the breccia pipe (yellow silica glaze) toward the fault (green silica glaze), where the seepage of meteoric water and Eh are higher.

  15. Gamma-ray characterization of uranium-series nuclides and its application to the study of the Pena Blanca natural analogue site, Chihuahua, Mexico

    NASA Astrophysics Data System (ADS)

    Wong, Virgina

    Two natural analogue sites located in the Pena Blanca Uranium District, Chihuahua, Mexico were characterized for radionuclide mobility. Analogue I is used to assess the long-term behavior of uranium-series nuclides in a host rock and geochemical environment that is similar to the proposed high-level waste repository at Yucca Mountain, Nevada. Analogue II represents a former dump site to assess short-term radionuclide mobility. Gamma-ray spectroscopy analysis was used to measure radioactivity of the U-series nuclides. Samples analyzed from Analogue I consist of: (1) fracture-infillings associated with different alteration assemblages collected within and outside the breccia pipe from various levels of the deposit and (2) fracture-infillings collected along an east-west trending fracture which intersects the breccia pipe and extends into the host rock. Alteration mineralogy, established via X-ray diffraction analysis, consists of pure kaolinite, a mixture of Fe-oxyhydroxide (goethite, hematite) With inclusions of jarosite and alunite, and carbonates. Results from activity ratios of 230Th/238U versus 226Ra/230Th indicate that majority of the Fe-oxyhydroxides from the breccia zone show a slight disequilibrium with respect to Ra enrichment and U depletion. This observation is modeled as requiring a multiple-event history of U mobility. An amorphous Fe sample distal to the breccia zone shows similar behavior but to a greater extent. This extreme behavior is ascribed to initially low U content and greater late-stage U removal. Two Fe-oxyhydroxide samples from Within the breccia pipe also display multiple-event stages but exhibit both Ra and U leaching. This behavior is shared by Fe-oxyhydroxide samples collected inside and peripheral to the breccia zone from the east-west trending fracture. Finally, three samples, two Fe phase samples outside the breccia zone and a kaolinite inside the breccia zone, show Ra and U enrichment. Also, a distal Fe-oxyhydroxide sample from the

  16. The effects on photosynthetic CO{sub 2} assimilation to long-term elevation of atmospheric CO{sub 2} concentration: An assessment of the response of Trifolium Repens L. cv. Blanca grown at F.A.C.E.

    SciTech Connect

    Lewis, C.E.

    1994-11-01

    Understanding how photosynthetic capacity acclimates to elevated CO{sub 2} concentrations is vital in predicting the response of important grassland species such as Trifolium repens. Previous studies of acclimatization have been carried out in artificial experimental conditions, such as acrylic greenhouses or controlled environment chambers. The advent of FACE technology has enabled a large area of crop to be fumigated in the field, providing more realistic growing conditions. Pure stands of Trifolium repens L. cv. Blanca grown at either 355 or 600{mu}mol mol{sup -1} CO{sub 2} were examined, and their photosynthetic response to elevated Ca determined via gas exchange studies. Rates of photosynthesis of young, fully expanded leaves were increased between 21 and 36% when grown and measured at elevated CO{sub 2}. This increase in A corresponded to a decrease in g{sub S} of between 18 and 52%. No acclimation effect was observed in the most frequently cut stands, whilst the response of stands clipped only 4 times per year was more variable. When down regulation of V{sub cmax} did occur, this was not nearly as marked as that which occurred in 3 other temperate species (Chrysanthemum leucanthemum, Ranunculus friesianus, Plantago lanceolata (L.) J. & C. Presl.), at similar growth regimes. No acclimation of stomatal frequency, SI or pore length was found to occur in the enriched clover stands.

  17. Infection par le virus de l’hépatite E durant la grossesse

    PubMed Central

    Chaudhry, Shahnaz A.; Verma, Natasha; Koren, Gideon

    2015-01-01

    Résumé Question Plusieurs de mes patientes sont originaires de l’Asie du Sud-Est où le virus de l’hépatite E est assez commun. Quelles précautions puis-je leur suggérer de prendre avant de voyager dans cette région et quels sont les risques d’une infection par le VHE durant la grossesse? Réponse L’hépatite E est un pathogène présent dans l’eau qui se transmet par voie oro-fécale. Afin de réduire le risque de contracter le VHE lors de voyages dans des régions endémiques, il est important de maintenir des pratiques d’hygiène telles que se laver les mains avec de l’eau potable, particulièrement avant de manipuler de la nourriture, éviter de boire de l’eau ou d’utiliser des glaçons de pureté inconnue et ne pas manger de fruits ou de légumes non pelés. Actuellement, il n’existe aucun vaccin disponible au Canada pour le VHE. Une infection à l’hépatite E durant la grossesse, surtout durant le troisième trimestre, se caractérise par une infection plus sévère qui se transforme parfois en hépatite fulminante, augmentant ainsi les risques de mortalité et de morbidité maternelles et fœtales.

  18. Les succédanés du sucre durant la grossesse

    PubMed Central

    Pope, Eliza; Koren, Gideon; Bozzo, Pina

    2014-01-01

    Résumé Question J’ai une patiente enceinte qui consomme souvent des succédanés du sucre et elle m’a demandé si cette pratique continue pouvait nuire à sa grossesse ou à son enfant. Que devrais-je lui répondre et existe-t-il d’autres meilleurs choix durant la grossesse? Réponse Il faudrait faire plus de recherche pour déterminer plus exactement les effets de l’exposition aux succédanés du sucre in utero, mais les données disponibles ne laissent pas présager d’effets indésirables durant la grossesse. Toutefois, il est recommandé de consommer des substituts du sucre en quantités modérées et de se conformer aux doses journalières admissibles établies par les organismes de règlementation.

  19. Tratamiento ayuda a mujeres jóvenes a preservar fertilidad durante quimioterapia para cáncer de seno

    Cancer.gov

    Las mujeres jóvenes con cáncer de seno (mama) lograron preservar la fertilidad durante los tratamientos del cáncer con un fármaco inyectable bloqueador de hormonas que les provocó menopausia temporal. Los resultados del estudio se anunciaron hoy en el con

  20. Glacier changes since Local Last Glacial Maximum in the South-West slope of Nevado Hualcán, Cordillera Blanca, Peru, deduced from moraine mapping and GIS-based analysis

    NASA Astrophysics Data System (ADS)

    Giráldez, Claudia; Palacios, David; Haeberli, Wilfried; Úbeda, Jose; Schauwecker, Simone; Torres, Judith

    2014-05-01

    Anticipating and assessing hazards and risks associated with the shrinking of surface and subsurface ice in cold mountain chains is facilitated by empirical-quantitative data on present and past rates of change, as well as by a general understanding of related landforms and landscape evolution through time. Rock/ice avalanches and devastating outburst floods from glacial lakes indeed constitute a major cause of severe damage in populated mountain areas such as the Cordillera Blanca whose combination of tectonic, topographic and glaciological characteristics make it a threatened region. This study focuses on the Río Chucchún catchment above the city of Carhuaz, which was recently affected by a flood/debris flow from a rock/ice avalanche impacting a recently grown lake (Laguna 513). Traces left by past glaciations strongly affect the current geomorphodinamic behaviour of the catchment. For instance, a prominent sediment-filled glacial overdeepening behind Younger Dryas (YD) moraines (Pampa de Shonquil) with its retention function strongly influenced the chain of processes initiated by the outburst of Laguna 513. The aim of this study is to reconstruct earlier glacial phases in the SW slope of Nevado Hualcán (Río Chucchún catchment), in order to compile quantitative information on surface areas and Equilibrium Line Altitudes (ELAs). To do so, glacier stages were assigned to five different glacial phases, through photointerpretation and moraine cartography: 2003; 1962; Hualcán-I-LIA (15th to 18th centuries); Hualcán-II-YD (~12,5 ka BP); and Hualcán-III-LLGM (~34 to 21 ka BP). Glacial stages Hualcán-I-LIA, Hualcán-II-YD and Hualcán-III-LLGM present relative dating based on previous studies from different authors in the Peruvian Andes. Once glaciers were delimited, their surface areas and Equilibrium Line Altitudes (ELAs) were calculated. For ELA estimation three different methods were used: the mid-range elevation, the Accumulation Area Ratio (AAR), and the

  1. Propriedades de estruturas temporais rápidas submilimétricas durante uma grande explosão solar

    NASA Astrophysics Data System (ADS)

    Raulin, J.-P.; Kaufmann, P.; Gimenez de Castro, C. G.; Pacini, A. A.; Makhmutov, V.; Levato, H.; Rovira, M.

    2003-08-01

    Apresentamos novas propriedades de variações rápidas da emissão submilimétrica durante uma das maiores explosões solares do ciclo solar 23. Os dados analisados neste estudo foram obtidos com o Telescópio Solar Submilimétrico (SST), que observa o Sol em 212 GHz e 405 GHz, e comparados com emissões em Raios-X duros e Raios-gama (fótons de energia > 10 MeV), que foram obtidas pelo experimento GRS do Yohkoh. Aplicamos diferentes metodologias para detectar e caracterizar, ao longo do evento, os pulsos submilimétricos (duração de 50-300 ms) detectados acima de uma componente mais lenta (alguns minutos). Os resultados mostram que durante a fase impulsiva, num instante próximo ao tempo do máximo do evento, houve um aumento da ocorrência de maiores e de mais rápidas estruturas temporais. Também identificamos uma boa correlação com as emissões em raios-X e raios-gama (até a faixa de energia 10-100 MeV), indicando que os pulsos rápidos submilimétricos refletiram injeções primárias de energia durante o evento.O espectro do fluxo desses pulsos é crescente com a freqüência entre 212 and 405 GHz, na maioria dos casos, ao contrário do observado para a componente gradual. As posições calculadas para as estruturas rápidas são discretas, compactas e localizadas em toda a área da região ativa, o que é previsto nos modelos de explosões solares decorrentes de instabilidades múltiplas em diferentes pequenas regiões. Por outro lado, a posição calculada para a componente lenta é estável durante a fase impulsiva. Assim, a comparação entre as características do espectro de fluxo e da localização da emissão, para os pulsos rápidos e para a componente gradual, sugere que as respectivas emissões são de natureza diferente.

  2. Materials Data on BaTaS3 (SG:194) by Materials Project

    SciTech Connect

    Kristin Persson

    2015-02-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  3. L’inhalation de corticostéroïdes est-elle sécuritaire durant la grossesse?

    PubMed Central

    Smy, Laura; Chan, Alvin C.H.; Bozzo, Pina; Koren, Gideon

    2014-01-01

    Résumé Question Une femme atteinte d’asthme léger à modéré, autrement en santé, s’est présentée à ma clinique aujourd’hui après avoir appris qu’elle était enceinte. Elle m’a demandé si elle devait continuer à prendre ses corticostéroïdes en inhalation (CSI) et, dans l’affirmative, s’il pourrait y avoir des risques pour son enfant à naître. Quels seraient vos conseils à ce propos? Réponse Compte tenu des données probantes publiées, les CSI devraient être continués durant toute la grossesse à des doses allant de faibles à modérées et suffisantes pour contrôler les symptômes de l’asthme et prévenir les exacerbations. Il faut toutefois être prudent quand il s’agit de doses de plus de 1 000 µg/j (d’équivalent de béclométasone avec chlorofluorocarbures), quoiqu’il soit actuellement questionnable si de telles doses causeraient des effets indésirables. Il faut renseigner de manière continue les patientes sur l’administration appropriée des CSI et l’observance du traitement, y compris durant le premier trimestre. Un bon contrôle de l’asthme réduira la nécessité de doses plus fortes de CSI et de l’exposition possible à des corticostéroïdes systémiques et diminuera ainsi le risque de résultats périnatals ou de grossesse indésirables.

  4. Sécurité de la plus récente classe d’antagonistes des opioïdes durant la grossesse

    PubMed Central

    Poon, Shirley; Pupco, Anna; Koren, Gideon; Bozzo, Pina

    2014-01-01

    Résumé Question J’ai une patiente dont 6 semaines de grossesse viennent d’être confirmées. Depuis 6 mois, elle suit une thérapie pour une dépendance aux opioïdes à l’aide d’une combinaison de buprénorphine et de naloxone. Devrais-je m’inquiéter qu’elle ait été exposée à cette combinaison de médicaments jusqu’à ce stade de sa grossesse? Faudrait-il que je change sa médication pour de la méthadone maintenant qu’elle est enceinte? Réponse Les données limitées sur l’exposition à la buprénorphine durant la grossesse ne révèlent pas d’augmentation du risque de résultats indésirables chez le nouveau-né. Il y a peu de données sur la naloxone durant la grossesse; par ailleurs, on ne s’attendrait pas à ce que l’administration par voie orale soit associée avec un risque accru de résultats de grossesse défavorables. On conseille aux médecins qui traitent des femmes enceintes ou qui deviennent enceintes et dont l’état est stable en prenant une thérapie à la buprénorphine et naloxone de continuer ce traitement mais d’envisager une transition à une monothérapie à la buprénorphine.

  5. Pena blanca natural analogue project: summary of activities

    SciTech Connect

    Levy, Schon S; Goldstein, Steven J; Abdel - Fattah, Amr I

    2010-12-08

    The inactive Nopal I uranium mine in silicic tuff north of Chihuahua City, Chihuahua, Mexico, was studied as a natural analogue for an underground nuclear-waste repository in the unsaturated zone. Site stratigraphy was confirmed from new drill core. Datafrom site studies include chemical and isotopic compositions of saturated- and unsaturated-zone waters. A partial geochronology of uranium enrichment and mineralization was established. Evidence pertinent to uranium-series transport in the soil zone and changing redox conditions was collected. The investigations contributed to preliminary, scoping-level performance assessment modeling.

  6. Astrosismología de estrellas enanas blancas

    NASA Astrophysics Data System (ADS)

    Córsico, A. H.

    2015-08-01

    Most of low- and intermediate-mass stars that populate the Universe will end their lives as white dwarf stars. These ancient stellar remnants have encrypted inside a precious record of the evolutionary history of the progenitor stars, providing a wealth of information about the evolution of stars, star formation, and the age of a variety of stellar populations, such as our Galaxy and open and globular clusters. While some information like surface chemical composition, temperature and gravity of white dwarfs can be inferred from spectroscopy, the internal structure of these compact stars can be unveiled only by means of asteroseismology, an approach based on the comparison between the observed pulsation periods of variable stars and the periods of appropriate theoretical models. In this communication, we first briefly describe the physical properties of white dwarf stars and the various families of pulsating white dwarfs known up to the present day, and then we present two recent analysis carried out by the La Plata Stellar Evolution and Pulsation Group in this active field of research.

  7. Pena Blanca Natural Analogue Project: Summary of activities

    SciTech Connect

    Levy, S.; Goldstein, S.; Dobson, P.F.; Goodell, P.; Ku, T.-L.; Abdel-Fattah, A.; Saulnier, G.; Fayek, M.; de la Garza, R.

    2011-02-01

    The inactive Nopal I uranium mine in silicic tuff north of Chihuahua City, Chihuahua, Mexico, was studied as a natural analogue for an underground nuclear-waste repository in the unsaturated zone. Site stratigraphy was confirmed from new drill cores. Data from site studies include chemical and isotopic compositions of saturated- and unsaturated-zone waters. A partial geochronology of uranium enrichment and mineralization was established. Evidence pertinent to uranium-series transport in the soil zone and changing redox conditions was collected. The investigations contributed to preliminary, scoping-level performance assessment modeling.

  8. [Four infants with upper urinary tract infection due to extended-spectrum bata lactamase (ESBL)-producing Escherichia coli].

    PubMed

    Hibino, Satoshi; Fukuchi, Kunihiko; Abe, Yoshifusa; Hoshino, Akihiro; Sakurai, Shunsuke; Mikawa, Takeshi; Fuke, Toshiya; Yoshida, Koichiro; Itabashi, Kazuo

    2011-09-01

    Bacteria producing extended-spectrum beta lactamase (ESBL) are detected mainly in adult urinary specimens, and are believed to cause hospital-acquired infection due to their resistance to many drugs. The incidence of community-acquired infection due to such bacteria is increasing, but few cases of infant upper urinary tract infection (UUTI) have been reported in Japan. We treated four infants with UUTI caused by ESBL-producing Escherichia coli, as determined by genotyping. Using medical records, we retrospectively evaluated the clinical course, antibiotic use and efficacy, antimicrobial susceptibility results, and the presence of underlying disease. One of the four had been previously hospitalized for occult bacteremia. Two developed UUTI after antibiotic treatment, indicating that previous antibiotic use may have been a risk factor in these cases. We could not identify the infection route in all cases. Two of the four had bilateral vesicoureteral reflux (VUR). Renal scintigraphy was done in three. Although an initial dimercaptosuccinic acid (DMSA) defect was detected in all four, only one had renal scarring. E. coli isolates from all four showed PCR signals for blaCTX-M-; one isolate positive for the blaCTX-M3 group and three positive for blaCTX-M14. Antimicrobial susceptibility test results showed all isolates to be resistant to cephalosporins, but discrepancies existed between antimicrobial susceptibility results and actual clinical efficacy. Clinically, cefazolin (CEZ) was effective in two subjects and ceftazidime (CAZ) effective in one. Panipenem/betamipron (PAPM/BP) was effective in one. None of the four developed sepsis or meningitis. Post hospitalization antibiotic prophylaxis showed that none of the four has had UUTI recur. Japan's ESBL-producing bacterial infection incidence is increasing, so medical professionals should watch for such UUTI even in first-case occurrence in infants. PMID:22117375

  9. Résultats à long terme de la transplantation hépatique orthotopique durant l'ère de la cyclosporine12

    PubMed Central

    Lerut, J.; Stieber, A. C.; Makowka, L.; Esquivel, C. O.; Iwatsuki, S.; Gordon, R. D.; Starzl, T. E.

    2010-01-01

    Résumé 313 patients ont subi consécutivement à l'Université de Pittsburgh 393 transplantations hépatiques orthotopiques (THO) durant l'ère de la cyclosporine 1980–1984. Tous les patients ont été suivis au moins durant trois ans après la transplantation ou jusqu'au moment de leur décès. 216 (69%) des 313 patients ont survécu au moins une année après la THO; 26 patients (12%) sont décédés après la première année postopératoire. Les résultats de la transplantation hépatique pour les diverses indications sont discutés. Les taux de survie actuarielle à cinq ans pour les maladies métaboliques, les atrésies des voies biliaires, la cirrhose biliaire primitive, la cholangite sclérosante primitive, la cirrhose posthépatitique et les tumeurs hépatobiliaires primitives sont respectivement de 75%, 68%, 60%, 58,9%, 53,2%, 23,8%. La récidive de la maladie primaire après THO pour maladie hépatique bénigne est, à l'exception de la cirrhose posthépatique B et le syndrome de Budd-Chiari, rare; elle est par contre élevée après THO réalisée pour maladie hépatobiliaire maligne. 27% (86) des 313 patients ont subi 112 retransplantations hépatiques durant la période du follow-up. 45 (21%) des 216 patients survivant plus qu'une année après la THO ont dû être traités pour un rejet de leur greffon; 18 patients ont dû être retransplantés pour un rejet chronique du greffon. Les complications extrahépatiques, survenant plus d'une année après la transplantation hépatique, sont plutôt rares (19/216 patients – 8,8%). Seulement trois patients ont dû subir une modification de la thérapie d'immunosuppression à cyclosporine pour cause d'insuffisance rénale incontrôlable. La qualité de vie des patients ayant une survie à long terme est excellente. 37 patients de cette série ont survécu au moins cinq ans après la THO. 81% (17/21) des enfants et douze des seize adultes (75%) ont une réintégration familiale, écolière et

  10. Regulación del flujo sanguíneo uterino. I. Funciones de estrógeno y receptores estrogénicos α/β en el endotelio vascular uterino durante el embarazo

    PubMed Central

    Mayra, Pastore R.; Rosalina, Villalón L.; López, Gladys; Iruretagoyena, Jesús; Magness, Ronald

    2015-01-01

    Resumen El estrógeno y los receptores estrogénicos clásicos (REs), RE-α y RE-β, han demostrado ser parcialmente responsable por las adaptaciones endoteliales uterinas durante el embarazo al corto y largo plazo. Las diferencias moleculares y estructurales, junto con los diferentes efectos causados por estos receptores en las células y los tejidos, sugieren que su función varía dependiendo de la manera en la cual el estrógeno se comunica con sus receptores. En ésta revisión bibliográfica se discuten la función del estrógeno y sus receptores clásicos en las adaptaciones cardiovasculares durante el embarazo y la expresión de los Res in vivo e in vitro en el endotelio de la arteria uterina durante el ciclo ovárico y el embarazo, a la vez comparado con la expresión en endotelio arterial de tejidos reproductivos y no reproductivos. Estos temas integran el conocimiento actual de este amplio campo científico con interpretaciones e hipótesis diversas relacionadas con los efectos estrogénicos mediados bien sea por uno o los dos REs. Esta revisión también incluye la relación con las adaptaciones vasodilatadoras y angiogénicas requeridas para modular el dramático incremento fisiológico en la perfusión útero-placentaria observada durante un embarazo normal. PMID:26113750

  11. Malformaciones arteriovenosas revisión y análisis descriptivo de 52 mavs tratadas durante el periodo de 2000-2010

    PubMed Central

    Rinaldi, Mariano; Mezzano, Emilio; Berra, Matias S.; Parés, Herald R.; Olocco, Ricardo V.; Papalini, Francisco R.

    2015-01-01

    Objetivo: Describir nuestra experiencia en el manejo de las Mavs analizando las características clínicas de los pacientes y los resultados postoperatorios. Método de análisis: Realizamos un análisis retrospectivo de 52 pacientes admitidos en el Servicio de neurocirugía para manejo quirúrgico: La información de referencia incluyo síntomas al inicio, diagnostico de admisión, hallazgos neurológicos y hallazgos en estudio por imágenes tales como tomografía cerebral, IRM cerebral y angiografía por sustracción digital. Los hallazgos postoperatorios de interés fueron: Mortalidad, examen neurológico postoperatorio y complicaciones asociadas. Presentamos nuestro análisis estadístico. Resultados: Edad promedio: 37,7 años. Distribución: Hombres: 61,5%. Motivos de consulta más frecuentes: Cefalea 63,5%, evento hemorrágico 59,6%, convulsiones 26,9%. Localización: Supratentorial: 92,9%, Infratentorial: 7,2%. 30,8%, de las Mavs fueron grado 2 y grado 3 Cincuenta por ciento del total presentaron aneurismas, del total de la MAVs, 59,6% debutó con sangrado, 26,9% con Crisis Convulsivas y 13,5% con déficit neurológico. Recibieron tratamiento endovascular previo a cirugía 30,7%. Durante el postoperatorio 23,1% presentaron mejoría clínica, 57,7% no presento modificación, 19,2% empeoraron en el postoperatorio. La mortalidad fue 13,5%. Conclusión: Creemos que el subgrupo de Mavs grados III a V representan una entidad que requiere una compleja toma de decisiones dada la alta incidencia de aneurismas asociados que presentan y su asociación con eventos de sangrado. Nuestra mortalidad postoperatoria coincide con la bibliografía. Palabras clave, Mavs- aneurismas asociados- Acv hemorrágico- convulsiones. PMID:26600984

  12. Cómo aumentar la actividad física de los niños durante el período del recreo en las escuelas

    PubMed Central

    Ludwig, David

    2014-01-01

    Objetivos. Analizamos si la participación de las escuelas en el Programa de Mejoramiento del Recreo (PMR) en la primavera del año 2011 estuvo asociada a tasas más altas de actividad física intensa en los niños. Métodos. En el PMR, un coordinador dirige a los niños para que practiquen juegos adecuados para la edad a fin de aumentar su nivel de actividad física. Durante el recreo en 25 escuelas primarias públicas de la ciudad de Nueva York (15 participantes en el PMR, 10 no participantes en el PMR) los investigadores observaron algunas áreas predeterminadas (n = 1 339 observaciones) y registraron el número de niños que estaban sedentarios, caminando o muy activos. Resultados. Tras el análisis estadístico con múltiples variables se encontró que la participación en el PMR era una variable predictiva significativa (P = 0,027) de la tasa de actividad física intensa (porcentaje de niños muy activos en las áreas de observación) cuyas medias de los mínimos cuadrados fueron de 41% en las escuelas participantes en el PMR y de 27% en escuelas no participantes en el PMR. En las escuelas participantes en el PMR se siguió registrando una tasa significativamente superior incluso cuando el coordinador de juegos no estaba en el área de observación, lo que sugiere un cambio en la cultura del recreo en las escuelas que participan en este programa. Conclusiones. La tasa de actividad física intensa en las escuelas participantes en el PMR fue 14 puntos porcentuales (o 52%) superior a la tasa registrada en las escuelas no participantes en el PMR. Esta intervención de bajo costo podría ser un agregado valioso a las herramientas para combatir la obesidad infantil y podría valer la pena reproducirla en otros sitios. PMID:24899455

  13. Astronomy Teaching and Teachers Continuing Education: the Interdisciplinarity during a Total Lunar Eclipse. (Spanish Title: Enseñanza de la Astronomía y la Formación Continua de Profesores: la Interdisciplinariedad Durante un Eclipse Total de Luna.) Educação EM Astronomia E Formação Continuada de Professores: a Interdisciplinaridade Durante um Eclipse Lunar TOTAL

    NASA Astrophysics Data System (ADS)

    Langhi, Rodolfo

    2009-07-01

    This paper describes how 67 teachers from 23 cities, could awaken, in students, the scientific interest, using a natural astronomical phenomenon: a total lunar eclipse. Before and after of eclipse, meetings for continuing education were characterized by interdisciplinarity of astronomy and the importance of these observations. Working groups were formed by teachers and students, who organized the survey data, mobilizing the people in their cities. The results point ways about how to provide the scientific culture and the motivation to learn science in students, using approaches between the following communities: scientific, amateur and school. En este artículo se describe cómo 67 profesores de 23 ciudades, despertó el interés científico en los estudiantes mediante un fenómeno astronómico: un eclipse total de Luna. Antes y después del eclipse, reuniones para la formación continua se centraron en la interdisciplinariedad de la astronomía, y la importancia de las observaciones de este tipo de fenómeno. Profesores y estudiantes formaron grupos de trabajo para investigar datos durante el eclipse, con el participación de la comunidad en sus ciudades. Los resultados apuntan a las opciones que conducen a la cultura científica y la motivación para aprender la ciencia, utilizando las relaciones de los siguientes grupos: científicos, aficionados y la escuela. Este texto relata como 67 professores, provenientes de 23 cidades, puderam despertar, nos alunos, o interesse científico utilizando um fenômeno natural astronômico: um eclipse lunar total. O evento foi precedido e procedido por encontros de formação continuada, onde se caracterizou a interdisciplinaridade da astronomia e a importância das observações de fenômenos como estes. Grupos de trabalho foram formados por professores e alunos, que se organizaram para o levantamento conjunto de dados durante o fenômeno, além do envolvimento da comunidade em suas respectivas cidades. Os resultados apontam

  14. Épidémiologie descriptive de la brûlure dans un territoire de santé exemple du « territoire nord franche-comté » durant l’année 2014

    PubMed Central

    Fortin, J.L.; Bitar, M.P.; Marx, T.; Macher, J.M.; Desmettre, T.; Ravat, F.; Labourey, J.M.; Capellier, G.

    2015-01-01

    Summary Cette étude est une analyse épidémiologique rétrospective du recours aux services de santé du nord de la Franche-Comté en raison d’une brûlure durant l’année 2014 (114 patients). L’âge moyen était de 26 ans (8 mois-81 ans), 1/3 des brûlures ont touché des enfants de moins de 15 ans. Les brûlures, plus fréquentes l’été, surviennent principalement autour de l’heure des repas, les jours « sans école », à domicile, avec un liquide chaud. Elles sont peu étendues (4,81% de la SCT) et souvent superficielles. Elles nécessitent un passage dans un Service d’Accueil des Urgences dans 88,59% des cas, suivi d’un transfert en CTB (Lyon plus que Nancy ou Metz) dans 12,28% des cas. PMID:27252605

  15. Autoreporte de exposición a publicidad y promoción de tabaco en una cohorte de fumadores mexicanos: Antes y durante la publicación de la Ley General para el Control del tabaco en 2008

    PubMed Central

    Hernández, Rosaura Pérez; Thrasher, James F.; Bolaños, Rosibel Rodríguez; Gutiérrez, Inti Barrientos; Hernández, Norma A Ibañez

    2015-01-01

    Resumen Objetivo Determinar en población fumadora el nivel de exposición a la mercadotecnia por parte de la Industria Tabacalera (IT), a través de diferentes métodos de promocionar sus productos de tabaco, antes y durante la publicación de la Ley General para el Control del Tabaco (LGCT) en 2008. Material y métodos Estudio de cohorte en fumadores adultos (n=941 pre-LGCT y n=1051 post-LGCT) de cuatro ciudades mexicanas. Se realizaron análisis multivariados mediante modelos de ecuaciones de estimación generalizada (GEE). Resultados Se incremento el autoreporte de recepción de muestras gratis de cigarros (3.7% a 8.1%), ropa o artículos con marcas o logos (3.6% a 6.4%), haber visto información sobre eventos especiales (1.9% a 4.7%), y bares, antros y discos para mayores de edad (21.4% a 28%). Se observaron decrementos de publicidad en exteriores (54.7% a 47.2%). Conclusión Es necesaria una política integral con prohibiciones totales de la publicidad y promoción de los productos de tabaco que integre mayor vigilancia y sanciones para lograr la disminución y prevención del consumo de tabaco. PMID:22689158

  16. Climate Change and Mountain Community Fire Management in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    All, J.; Medler, M.; Cole, R. J.; Arques, S.; Schmitt, C. G.

    2014-12-01

    In the central Andes of Peru, climate change is altering fire risk through changes in local meteorology and fuel loading. Greater moisture and favorable growing conditions are increasing vegetative productivity, which in turn increases fuel loads. This process is accentuated during El Nino events and potentially results in increased fire occurrence and frequency during relatively dry La Nina events. Park officials are concerned about the ramification of the changes on local ecology and tourist use of the resources. However, using a time-series of two different products from the MODIS Terra and Aqua platforms (Active Fire and Burned Area), TRMM 3B43 precipitation data, and Multivariate ENSO Index data we document fire occurrence and extent from 2000 to 2010 and our analysis indicates that fires are burning exclusively during winter months when there are no natural ignition sources. Globally, fire is used in conjunction with grazing to improve the regeneration and yield of grasses. During our interviews, locals claimed to only set fires in the buffer zone outside of the park, but our analysis indicates that the buffer zone rarely burns and that most fires begin within the park and only occasionally move into the buffer zones. Additionally, we determined that although this is small-scale fire activity every year, overall fire is having a very minor effect on local systems. The park service must develop programs to work with local grazing stakeholders to better limit the impacts of fire, while also address the negative perceptions from tourists in the future. In this instance, fire perception and fire reality are not the same and the challenge for resource managers is how to reconcile these two factors in order to more effectively manage the parklands.

  17. CartaBlanca-rapid prototyping development environment for non-linear systems on unstructured grids.

    SciTech Connect

    VanderHeyden, W. B.; Livescu, D.; Padial-Collins, N. T.

    2002-01-01

    This talk describes a component-based nonlinear physical system simulation prototyping package written entirely in Java using objectoriented design, The package provides scientists and engineers a 'developer-friendly' software environment for large-scale computational algorithm and physical model development, on the Jacobian-Free Newton-Krylov solution method surrounding a finite-volume treatment of conservation equations. This enables a clean component-like implementation. We first provide motivation for the development of the software and then discuss software structure. Discussion .includes a description of the use of Java's built-in thread facility that enables parallel, shared-memory computations on a wide variety of unstructured grids with triangular, quadrilateral, tetrahedral and hexahedral elements. We also discuss the use of Java's inheritance mechanism in the construction of a hierarchy of physics systems objects and linear and nonlinear solver objects that simplify development and foster software re-use. Following this, we show results from example calculations and then discuss plans including the extension of the software to distributed memory computer systems.

  18. Managing glacier related risks in the Chucchún Catchment, Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Muñoz, Randy; Gonzáles, César; Price, Karen; Frey, Holger; Huggel, Christian; Cochachin, Alejo; García, Javier; Mesa, Luis

    2015-04-01

    On April 11 2010, the city of Carhuaz and settlements in the Chucchún Catchment (Ancash region, Peru) suffered the impact of a glacier lake outburst flood. An avalanche of rock and ice from the Mount Hualcán hit the glacier lake 513, triggering a glacial lake outburst flood (GLOF) of 1 million m3 which destroyed farmland and several infrastructures. Although there was no loss of human life, the event caused panic in the population. In consequence, the Municipality of Carhuaz prioritized GLOF-related risk management. The Glacier Project, funded by Swiss Agency for Development and Cooperation, and executed by CARE Peru and the University of Zurich, fosters the coordination among public institutions (Glaciological Unit of the National Water Authority, the Ministry of Environment and Municipality) and the population for risk management. In this contribution we present all components of the risk management strategy as well as the lessons learned during the implementation. Risk management involves managing both glacier hazard as well as the vulnerability of the population. In this framework a glaciological and geomorphological characterization of Mount Hualcán and lake 513 was perfomed in order to model past and potential future outburst floods and to assess the slope stability conditions. Based on three potential GLOF scenarios of different magnitudes, a hazard map was produced for the entire catchment, which served as the basis for the vulnerability and risk assessment as well as for the design and the implementation of an Early Warning System (EWS), including evacuation planning. The EWS consists of 4 components: 1) knowledge of risk, through hazard and vulnerability characterization; 2) monitoring and alert, through the installation of monitoring stations on lake 513 for detecting avalanches with geophones and cameras; 3) broadcasting and communications, through the implementation of communication protocols between the Municipality of Carhuaz and emergency institutions (police, health centers and schools) and also authorities at higher coordination levels (Regional Government and the National Emergency Operations Center) enabling rapid emergency care; and 4) Responsiveness, through strengthening and training of public and private institutions and local leaders that make up the Civil Defense Platforms, the development of Emergency Operations Plan, and continuous organization of simulations for the population. As result, the population is aware of the risks they face and knok how to respond in case of a lake outburst event. In addition, the results generated during studies related to the risk analysis are used for land management of the Municipality of Carhuaz. The successful implementation of this risk management strategy was only possible by combining comprehensively scientific and local knowledge. This EWS represents a pilot experience in Peru and the Andes, and contributes to relatively scarce international experience with GLOF EWS. An important lesson is that these processes require active leadership of local authorities and continuous learning by the population. The mere existence of technology does not ensure the success of the risk reduction measures; this can only be attained by the internalization of processes and by taking responsibility against the existing hazard by each resident, authority and institution.

  19. Evolución de estrellas enanas blancas con envolturas de hidrógeno.

    NASA Astrophysics Data System (ADS)

    Althaus, L. G.; Benvenuto, O. G.

    The present study is aimed at exploring the effects of hydrogen envelopes on the structure and evolution of white dwarf stars by means of a detailed and updated evolutionary code. In particular, we treat the energy transport by convection within the formalism of the full spectrum turbulence theory developed by Canuto, Goldman & Mazzitelli (1996) (CGM). Furthermore, we take into account convective mixing in the outer layers and a detailed network of thermonuclear reaction rates for hydrogen burning as well. Our attention is focused mainly on the ZZ Ceti evolutionary stage with the aim of assessing the compatibility of the CGM model with new observations of the hottest pulsating DA white dwarfs. We also extend our calculations to the case of low - mass helium white dwarfs, which have recently begun to be detected in various binary configurations.

  20. INITIAL TEST WELL CONDITIONING AT NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, CHIHUAHUA, MEXICO

    SciTech Connect

    R.D. Oliver; J.C. Dinsmoor; S.J. Goldstein; I. Reyes; R. De La Garza

    2005-07-11

    Three test wells, PB-1, PB-2, and PB-3, were drilled at the Nopal I uranium deposit as part of a natural analogue study to evaluate radionuclide transport processes during March-April 2003. The initial pumping to condition the wells was completed during December 2003. The PB-1 well, drilled immediately adjacent to the Nopal I ore body, was continuously cored to a depth of 250 m, terminating 20 m below the top of the measured water level. The PB-2 and PB-3 wells, which were drilled on opposite sides of PB-1 at a radial distance of approximately 40 to 50 m outside of the remaining projected ore body, were also drilled to about 20 m below the top of the measured water level. Each test well was completed with 4-inch (10.2-cm) diameter PVC casing with a slotted liner below the water table. Initial conditioning of all three wells using a submersible pump at low pump rates [less than 1 gallon (3.8 1) per minute] resulted in measurable draw down and recoveries. The greatest drawdown ({approx}15 m) was observed in PB-2, whereas only minor (<1 m) drawdown occurred in PB-3. For PB-1 and PB-2, the water turbidity decreased as the wells were pumped and the pH values decreased, indicating that the contamination from the drilling fluid was reduced as the wells were conditioned. Test wells PB-1 and PB-2 showed increased inflow after several borehole volumes of fluid were removed, but their inflow rates remained less that the pumping rate. Test well PB-3 showed the smallest drawdown and least change in pH and conductivity during initial pumping and quickest recovery with a rise in measured water level after conditioning. The 195 gallons (750 l) of water pumped from PB-3 during conditioning was discharged through a household sponge. That sponge showed measurable gamma radiation, which decayed to background values in less than 12 hours. Preliminary interpretations include filtration of a radioisotope source with a short half-life or of a radioisotope that volatized as the sponge dried, such as Rn-222 and its short-lived daughters. No filtration was used during the pumping of PB-1 or PB-2.

  1. STRATIGRAPHY OF THE PB-1 WELL, NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, CHIHUAHUA, MEXICO

    SciTech Connect

    NA

    2005-06-25

    Three wells, PB-1, PB-2, and PB-3, were drilled in 2003 at the Nopal I uranium deposit as part of a natural analogue study to evaluate radionuclide transport processes. The wells penetrate through the Tertiary volcanic section down to the Cretaceous limestone basement, and intersect the top of the regional aquifer system. The PB-1 well, drilled immediately adjacent to the Nopal I ore body, was cored to a depth of 250 m, thus providing an opportunity to document the local stratigraphy. The uppermost unit encountered in the PB-1 well is the Nopal Formation, a densely welded, crystal-rich rhyolitic ash-flow tuff. The cored section is highly altered and devitrified, with kaolinite, quartz, chlorite, and montmorillonite replacing feldspars and much of the groundmass. Breccia zones within the tuff contain fracture fillings of hematite, limonite, and goethite. A zone of intense clay alteration encountered in the depth interval 17.45-22.30 m was interpreted to represent the basal vitrophyre of this unit. Underlying the basal vitrophyre is the Coloradas Formation, which consists of a welded, lithic-rich rhyolitic ash-flow tuff. The cored section of this unit has undergone devitrification and oxidation, and has a similar alteration mineralogy to that observed in the Nopal tuff. The Nopal I ore body is restricted to a brecciated zone that intersects these two volcanic units. A sharp contact between the Coloradas tuff and the underlying Pozos Formation was observed at a depth of 136.38 m. The Pozos Formation in the PB-1 core consists of interbedded, poorly sorted sandstone and conglomerate layers. The conglomeratic clasts consist of subangular to subrounded fragments of volcanic rocks, limestone, and chert. Thin (2-6 m) intervals of intercalated pumiceous tuffs were observed within this unit. The contact between the Pozos Formation and the underlying Cretaceous limestone basement was observed at a depth of 244.4 m.

  2. Structural analysis of the Cordillera Blanca detachment: Geometry, kinematics and fault rocks

    NASA Astrophysics Data System (ADS)

    Shaw, C. A.; Jessup, M. J.; Hughes, C. A.; Newell, D. L.

    2015-12-01

    The Cordillera Banca Detachment (CBD) in the north-central Peruvian Andes is recognized as a rare example of active extension parallel to the direction of shortening within a convergent orogenic setting. Despite longstanding interest in the geodynamic significance of the CBD relatively little work has been done to characterize the basic geometry, kinematics and evolution of the detachment or the petrology and distribution of brittle and ductile tectonites within the fault zone. This contribution presents preliminary results of a basic structural analysis of the CBD based on field observations, laboratory results, and GIS analysis. Basic structural observations of fault geometry and kinematics are needed to constrain the regional geodynamic role of the CBD. The NNW topographic trace of the CBD is defined by faceted ridges up to 2000 m in height. The lower slopes of the facets are locally cut by steep fault scarps that offset quaternary glacial moraines, debris fans and colluvium. The shear zone comprises both brittle and ductile tectonites including mylonite series rocks, pseudotachylyte, and breccia - often highly silicified. Highly polished mirrored surfaces are observed locally. Deformation mechanisms show a consistent progression from plastic in structurally lower positions to brittle in structurally higher positions. Evidence for overprinting deformation mechanisms is preserved in many samples. The shear zone ranges up to about 200 m thick. The average orientation of mylonitic foliation and fault slip surfaces (strike/dip = 140/30) and lineations/slickenlines (plunge-trend = 35-235) is quite consistent along the ~200 km detachment, but some systematic variation along strike may be related to concave fault segments or corrugations. Slip indicators are nearly down-dip with a minor left-lateral or right-lateral component in some locations. Offsets in marker horizons constrain total offset between about 4500 m near the central section of the fault to near zero approaching the fault tips. Structural observations are consistent with a long history of displacement across the CBD resulting in the progressive exhumation of deep rocks under relatively constant tectonic conditions.

  3. FUTURE STUDIES AT PENA BLANCA: RADIONUCLIDE MIGRATION IN THE VADOSE ZONE OF AN ALLUVIAL FAN

    SciTech Connect

    P. Goodell; J. Walton; P.J. Rodriguez

    2005-07-11

    The pathway to the accessible environment at Yucca Mountain contains volcanic rocks and alluvial fill. Transport properties in alluvial fill, specifically retardation and dispersivity, may be significant in determining the overall performance of the repository. Prior relevant studies, with the exception of the Nye County Tracer Test, are almost entirely in bedrock material. The proposed study will provide field data on radionuclide migration in alluvial material. High grade uranium ore was mined at the Nopal I deposit. This mined ore (60,000 tons) was moved in 1994 to its present site as open piles on an alluvial fan in the Boquilla Colorada Microbasin. Precipitation is approximately 20 cm/year, and has caused migration of radionuclides into the subsurface. We propose partial removal of an ore pile, excavation into the alluvial fan, sampling, and determination of radionuclide mobilities from the uranium decay chain. The proposed research would be taking advantage of a unique opportunity with a known time frame for migration.

  4. Procesos cuasi-moleculares en enanas blancas frías

    NASA Astrophysics Data System (ADS)

    Rohrmann, R. D.; Althaus, L. G.; Kepler, S. O.

    We show that the radiation emitted by very cool white dwarf stars (Teff ~< 3000 K) with pure hydrogen atmospheres, is fully formed by radiative processes induced by atomic and molecular collisions. FULL TEXT IN SPANISH

  5. Índices de color en el infrarrojo cercano y medio de enanas blancas con y sin discos de escombros

    NASA Astrophysics Data System (ADS)

    Saker, L.; Gómez, M.; Chavero C.

    2015-08-01

    In this contribution we use different color indices in near and mid infrared (IR) to identify white dwarfs (WDs) with and without debris disks. To this aim, we employ magnitudes from WISE and 2MASS for a sample of 41 EBs with disks and other 52 objects without evidence of disks, but with similar stellar properties as the first group. For each of the analyzed color-color diagrams (W1W2 vs. W1W3, HW1 vs. JH) we define regions in which EBs with or without disks are located preferably. The usefulness of the color indices, particularly in WISE bands, to select candidates EBs with disks is discussed. Also, we investigate possible correlations between the color indices and other properties of stars, such as metal abundances.

  6. URANIUM-SERIES CONSTRAINTS ON RADIONUCLIDE TRANSPORT AND GROUNDWATER FLOW AT NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, MEXICO

    SciTech Connect

    S. J. Goldstein, S. Luo, T. L. Ku, and M. T. Murrell

    2006-04-01

    Uranium-series data for groundwater samples from the vicinity of the Nopal I uranium ore deposit are used to place constraints on radionuclide transport and hydrologic processes at this site, and also, by analogy, at Yucca Mountain. Decreasing uranium concentrations for wells drilled in 2003 suggest that groundwater flow rates are low (< 10 m/yr). Field tests, well productivity, and uranium isotopic constraints also suggest that groundwater flow and mixing is limited at this site. The uranium isotopic systematics for water collected in the mine adit are consistent with longer rock-water interaction times and higher uranium dissolution rates at the front of the adit where the deposit is located. Short-lived nuclide data for groundwater wells are used to calculate retardation factors that are on the order of 1,000 for radium and 10,000 to 10,000,000 for lead and polonium. Radium has enhanced mobility in adit water and fractures near the deposit.

  7. Spatio-temporal assessment of WRF, TRMM and in situ precipitation data in a tropical mountain environment (Cordillera Blanca, Peru)

    NASA Astrophysics Data System (ADS)

    Mourre, L.; Condom, T.; Junquas, C.; Lebel, T.; Sicart, J. E.; Figueroa, R.; Cochachin, A.

    2016-01-01

    The estimation of precipitation over the broad range of scales of interest for climatologists, meteorologists and hydrologists is challenging at high altitudes of tropical regions, where the spatial variability of precipitation is important while in situ measurements remain scarce largely due to operational constraints. Three different types of rainfall products - ground based (kriging interpolation), satellite derived (TRMM3B42), and atmospheric model outputs (WRF - Weather Research and Forecasting) - are compared for 1 hydrological year in order to retrieve rainfall patterns at timescales ranging from sub-daily to annual over a watershed of approximately 10 000 km2 in Peru. An ensemble of three different spatial resolutions is considered for the comparison (27, 9 and 3 km), as long as well as a range of timescales (annual totals, daily rainfall patterns, diurnal cycle). WRF simulations largely overestimate the annual totals, especially at low spatial resolution, while reproducing correctly the diurnal cycle and locating the spots of heavy rainfall more realistically than either the ground-based KED or the Tropical Rainfall Measuring Mission (TRMM) products. The main weakness of kriged products is the production of annual rainfall maxima over the summit rather than on the slopes, mainly due to a lack of in situ data above 3800 m a. s. l. This study also confirms that one limitation of TRMM is its poor performance over ice-covered areas because ice on the ground behaves in a similar way as rain or ice drops in the atmosphere in terms of scattering the microwave energy. While all three products are able to correctly represent the spatial rainfall patterns at the annual scale, it not surprisingly turns out that none of them meets the challenge of representing both accumulated quantities of precipitation and frequency of occurrence at the short timescales (sub-daily and daily) required for glacio-hydrological studies in this region. It is concluded that new methods should be used to merge various rainfall products so as to make the most of their respective strengths.

  8. 75 FR 2477 - Plan Development for Kiowa, Rita Blanca, Black Kettle and McClellan Creek National Grasslands...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-15

    ... using the provisions of the 1982 planning rule. Authority: 16 U.S.C. 1600-1614; 36 CFR 219.35 (74 FR... eligible Wild and Scenic Rivers; addressed travel management issues and oil and gas leasing stipulations... National Grasslands and will not be considered. In addition, some issues, such as wild and scenic...

  9. Uranium-series constraints on radionuclide transport and groundwater flow at the Nopal I uranium deposit, Sierra Pena Blanca, Mexico

    SciTech Connect

    Goldstein, S.J.; Abdel-Fattah, A.I.; Murrell, M.T.; Dobson, P.F.; Norman, D.E.; Amato, R.S.; Nunn, A. J.

    2009-10-01

    Uranium-series data for groundwater samples from the Nopal I uranium ore deposit were obtained to place constraints on radionuclide transport and hydrologic processes for a nuclear waste repository located in fractured, unsaturated volcanic tuff. Decreasing uranium concentrations for wells drilled in 2003 are consistent with a simple physical mixing model that indicates that groundwater velocities are low ({approx}10 m/y). Uranium isotopic constraints, well productivities, and radon systematics also suggest limited groundwater mixing and slow flow in the saturated zone. Uranium isotopic systematics for seepage water collected in the mine adit show a spatial dependence which is consistent with longer water-rock interaction times and higher uranium dissolution inputs at the front adit where the deposit is located. Uranium-series disequilibria measurements for mostly unsaturated zone samples indicate that {sup 230}Th/{sup 238}U activity ratios range from 0.005-0.48 and {sup 226}Ra/{sup 238}U activity ratios range from 0.006-113. {sup 239}Pu/{sup 238}U mass ratios for the saturated zone are <2 x 10{sup -14}, and Pu mobility in the saturated zone is >1000 times lower than the U mobility. Saturated zone mobility decreases in the order {sup 238}U{approx}{sup 226}Ra > {sup 230}Th{approx}{sup 239}Pu. Radium and thorium appear to have higher mobility in the unsaturated zone based on U-series data from fractures and seepage water near the deposit.

  10. Uranium-series constraints on radionuclide transport and groundwater flow at the Nopal I uranium deposit, Sierra Pena Blanca, Mexico.

    PubMed

    Goldstein, Steven J; Abdel-Fattah, Amr I; Murrell, Michael T; Dobson, Patrick F; Norman, Deborah E; Amato, Ronald S; Nunn, Andrew J

    2010-03-01

    Uranium-series data for groundwater samples from the Nopal I uranium ore deposit were obtained to place constraints on radionuclide transport and hydrologic processes for a nuclear waste repository located in fractured, unsaturated volcanic tuff. Decreasing uranium concentrations for wells drilled in 2003 are consistent with a simple physical mixing model that indicates that groundwater velocities are low ( approximately 10 m/y). Uranium isotopic constraints, well productivities, and radon systematics also suggest limited groundwater mixing and slow flow in the saturated zone. Uranium isotopic systematics for seepage water collected in the mine adit show a spatial dependence which is consistent with longer water-rock interaction times and higher uranium dissolution inputs at the front adit where the deposit is located. Uranium-series disequilibria measurements for mostly unsaturated zone samples indicate that (230)Th/(238)U activity ratios range from 0.005 to 0.48 and (226)Ra/(238)U activity ratios range from 0.006 to 113. (239)Pu/(238)U mass ratios for the saturated zone are <2 x 10(-14), and Pu mobility in the saturated zone is >1000 times lower than the U mobility. Saturated zone mobility decreases in the order (238)U approximately (226)Ra > (230)Th approximately (239)Pu. Radium and thorium appear to have higher mobility in the unsaturated zone based on U-series data from fractures and seepage water near the deposit. PMID:20136119

  11. Efectos difusivos en la formación de enanas blancas de Helio de baja masa en sistemas binarios cerrados

    NASA Astrophysics Data System (ADS)

    De Vito, M. A.; Benvenuto, O. G.

    In the last years, and thanks to advances in observational techniques, many astronomers have discovered in a great number of binary radio-pulsars the presence of a helium white dwarf resulting from a previous evolutionary state in which the progenitor of this star experienced one or more episodes of mass transfer to the compact component in the pair. That is the case for PSR B1855+09 (van Kerkwijk, M. H., Bell, J. F, Kaspi, V. M., & Kulkarni, S. R. 2000, ApJ 530, L37), where the mass for the white dwarf is known accurately from measurements of the Shapiro delay of the pulsar signal, MWD = 0.258+0.028-0.016 M⊙; for PSR J02018 + 4232 (Bassa, C. G., van Kerkwijk, M. H., & Kulkarni, S. R. 2003, A&A, 403, 1067), the spectra confirm that the companion is a helium-core white dwarf of ≈ 0.2 M⊙. On the other hand, there are several authors (Ferraro, F., Possenti, A., Sabbi, E., & D'Amico, N. 2003, ApJ, 596, L211; Bassa et al. 2003) that have identified the optical binary companion to the BMSP PSR J1911 - 5958A, located in the halo of the Galactic globular cluster NGC 6752, like a blue star whose position in the color-magnitude diagram is consistent with the cooling sequence of a low-mass, ≈ 0.17 - 0.20 M⊙, low metallicity helium white dwarf at the cluster distance. Finally, the color and magnitude of the stellar companion for B 1620-26 indicate that is a white dwarf of 0.34 ± 0.04 M⊙ (Sigurdson, S., Richer, H. B., Hansen, B. M., Stairs, I. H. & Thorset, S. E. 2003, Science, 301, 193S). This has motivated us to study the formation of low mass helium white dwarfs in the context of binary evolution. For that purpose, using the code of binary evolution, entirely developed in the Facultad de Ciencias Astronómicas y Geofísicas of the Universidad Nacional de La Plata, Argentina, we have investigated the effects of diffusive processes on the evolution of a star member of a close binary system. A similar study was performed for Althaus, L. G., Serenelli, A. M., & Benvenuto, O. G. (2001, MNRAS, 323, 471) but in that paper the mass transfer was mimicked by subtracting mass to a progenitor of 1 M⊙ to obtain the mass for the desired object. Actually, our binary code has a full nuclear reactions network for hydrogen and helium burning that allowed us to follow the abundances of fifteen isotopes throughout the entire evolution of the star. We have also included a detailed equation of state. The mass loss treatment is non conservative. We have modified the conditions for the beginning and end of mass transfer episodes. In our previous version, we assumed it to occur when the stellar radius was greater or smaller, respectively, that the Roche Lobe radius for the star. This introduced numerical problems, especially at the end of mass transfer phases. We adopted H. Ritter (1988, A&A, 202, 93) formulation that considers a finite scale height in the stellar atmosphere. The numerical behaviour in much more satisfactory, besides that it constitutes a more appropriate description for the physical problem. We perform the calculations for the evolution of the primary star in a close binary system of initial mass 2 M⊙, initial period of 1 day, initial mass ratio of 1.4142 and solar metallicity. We have done the calculations in four cases: A) with diffusion and all Roche Lobe overflows, B) with diffusion and only the first Roche Lobe overflow, C) without diffusion and all Roche Lobe overflows, D) without diffusion and only the first Roche Lobe overflow. Cases B) and D) where performed to compare with results obtained for Althaus et al. (2001). The main conclusion of this work is that the age of these objects is mainly determined by diffusive effects, and the late stages of mass transfer, not considered in Althaus et al. (2001), constituted a minor effect on the scales of cooling times.

  12. Evolution of the Astronomy Concepts Along Basic Education Cycle. (Breton Title: Evolução dos Conceitos de Astronomia no Decorrer da Educação Básica.) La Evolución de los Conceptos de Astronomía Durante la Educación Básica

    NASA Astrophysics Data System (ADS)

    Darroz, Luiz Marcelo; da Rosa, Cleci Werner; Becker da Rosa, Álvaro; Samudio Pèrez, Carlos Ariel

    2014-07-01

    learning of astronomy in basic education. Embora a astronomia seja considerada uma das ciências mais antigas da humanidade e ainda que a compreensão de seus conceitos tenha trazido enormes avanços para a Ciência e, consequentemente, para a sociedade, observa-se que uma parcela significativa de pessoas encontra-se à margem desses conhecimentos. De acordo com os Parâmetros Curriculares Nacionais para a Educação Básica, cabe à escola a difusão dos conceitos cientificamente corretos, entre eles os relacionados à área de astronomia. Pertinente a essa questão, apresenta-se uma pesquisa realizada com 140 estudantes do nono ano do ensino fundamental e com 120 estudantes da terceira série do ensino médio de quatro escolas da região de Passo Fundo/RS. Buscou-se averiguar, por meio de um questionário composto de questões abertas e de múltipla escolha, o conhecimento desse grupo de estudantes acerca de termos e fenômenos astronômicos básicos e, também, verificar se o índice de acertos cresce à medida que eles avançam nas diferentes e gradativas séries dos ensinos fundamental e médio. De modo geral, os resultados apresentados demonstram que o ensino de astronomia na educação básica enfrenta deficiências. Das 20 questões investigadas, em 17 os índices de acertos são semelhantes nas respostas dadas por estudantes de nível fundamental e médio, revelando que muitas concepções equivocadas permanecem ao longo da educação básica. Isso evidencia que tais temas não são - ou são pouco - abordados durante esses dois níveis de escolarização. Assim, conclui-se que a discussão dos conceitos relacionados com a astronomia deve receber maior ênfase na abordagem dos diferentes conteúdos, sendo necessária uma ação nacional em prol do seu ensino. Acredita-se que essa ação nacional deve estar apoiada em um pilar triplo de atores coletivos: comunidade científica, comunidade astronômica semiprofissional e comunidade escolar. Por fim, esse pilar seria

  13. Cybrids between Dancy tangerine (Citrus reticulata Blanca) and Ruby Red grapefruit (C. paradisi Mafc.) for improvement of citrus fruit traits [abstract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In cybridization, new combinations of nuclear and cytoplasmic genes result in a unique genotype that may bring cellular, physical, physiological and biochemical changes to the plant. This has been demonstrated in cybrids generated from the fusion of citrus protoplasts in two independent experiments....

  14. Acute toxicities of four metals on the early life stages of the crab Chasmagnathus granulata from Bahía Blanca estuary, Argentina.

    PubMed

    Ferrer, Laura; Andrade, Santiago; Asteasuain, Raúl; Marcovecchio, Jorge

    2006-10-01

    Acute semistatic toxicity tests were carried out for 96 h with first zoeae and young crabs of Chasmagnathus granulata. Survival curves and LC50 (lethal concentration 50, the concentration which produces the death of 50% of the exposed population) indices for copper, zinc, cadmium, and lead were determined. Furthermore, mixture toxicity tests (Cd/Cu and Cd/Zn) with first-stage larvae were also carried out. The LC50-96 h values determined in this study were 1093.4 (881-1319) microg Pb2+ L(-1), 219.2 (188.9-248.9) microg Cu2+ L(-1), 172.1 (141.3-203.6) microg Zn2+ L(-1), and 47.8 (37.9-58.0) microg Cd2+ L(-1) for zoeae I and 130.1 (121.7-139.0) mg Cu2+ L(-1), 51.0 (41.9-61.6) mg Zn2+ L(-1), and 35.7 (30.1-41.9) mg Cd2+ L(-1) for young crabs. The LC50-96 h indices for mixture tests with zoeae I were 260.6 (227.3-286.3) microg Cd2+/Zn2+ L(-1) and 41.3 (37.4-60.7) microg Cd2+/Cu2+ L(-1). Cadmium presented the highest acute toxicity for both stages of the life cycle examined. The toxicity of the metals analyzed followed the order cadmium >zinc>copper>lead. First zoeae were more sensitive than young crabs to acute exposure to all metals analyzed. The young crabs were considered potentially dangerous agents of transference to the associated trophic chain because of their relatively elevated resistance and their capacity to bioaccumulate heavy metals in their tissues. Mixed toxicity tests carried out on first-stage larvae showed different kinds of interactions. Cadmium/copper presented an additive interaction trend while the mixture cadmium/zinc showed an antagonistic interaction. PMID:16098589

  15. A Record of Uranium-Series Transport in Fractured, Unsaturated Tuff at Nopal I, Sierra Peña Blanca, Chihuahua, Mexico

    NASA Astrophysics Data System (ADS)

    Denton, J.; Goldstein, S. J.; Paviet, P.; Nunn, A. J.; Amato, R. S.; Hinrichs, K. A.

    2015-12-01

    In this study we utilize U-series disequilibria measurements to investigate mineral fluid interactions and the role fractures play in the geochemical evolution of an analogue for a high level nuclear waste repository, the Nopal I uranium ore deposit. Samples of fracture-fill materials have been collected from a vertical drill core and surface fractures. High uranium concentrations in these materials (12-7700 ppm) indicate U mobility and transport from the deposit in the past. U concentrations generally decrease with horizontal distance away from the ore deposit but show no trend with depth. Isotopic activity ratios indicate a complicated geochemical evolution in terms of the timing and extent of actinide mobility, possibly due to changing environmental (redox) conditions over the history of the deposit. 234U/238U activity ratios are generally distinct from secular equilibrium and indicate some degree of open system U behavior during the past 1.2 Ma. However, calculated closed system 238U-234U-230Th model ages are generally >313 ka and >183 ka for the surface fracture and drill core samples respectively, suggesting closed system behavior for U and Th over this most recent time period. Whole rock isochrons drawn for the drill core samples show that at two of three depths fractures have remained closed with respect to U and Th mobility for >200 ka. However, open system behavior for U in the last 350 ka is suggested at 67 m depth. 231Pa/235U activity ratios within error of unity suggest closed system behavior for U and Pa for at least the past 185 ka. 226Ra/230Th activity ratios are typically <1 (0.7-1.2), suggesting recent (<8 ka) radium loss and mobility due to ongoing fluid flow in the fractures. Overall, the mainly closed system behavior of U-Th-Pa over the past ~200 ka provides one indicator of the geochemical immobility of these actinides over long time-scales for potential nuclear waste repositories sited in fractured, unsaturated tuff.

  16. Oscilaciones estelares no-radiales: aplicación a configuraciones politrópicas y modelos de enanas blancas de He

    NASA Astrophysics Data System (ADS)

    Córsico, A. H.; Benvenuto, O. G.

    Recently in our Observatory we have developed a new Stellar Pulsation Code, independently of other workers. Such program computes eigenvalues (eigenfrequencies) and eigenfunctions of non-radial modes in spherical non-perturbated stellar models. To accomplish this calculations, the four order eigenvalue problem (in the linear adiabatic approach) is solved by means of the well-know technique of Henyey on the finite differences scheme wich replace to the differential equations of the problem. In order to test the Code, we have computed numerous eigenmodes in polytropic configurations for several values of index n. In this comunication we show the excelent agreement of our results and that best available in the literature. Also, we present results of oscillations in models of white dwarf stars with homogeneus chemical composition (pure Helium). This models have been obtained with the Evolution Stellar Code of our Observatory. The calculations outlined above conform a first preliminary step in a major proyect whose main purpose is the study of pulsational properties of DA, DB and DO white dwarfs stars. Detailed investigations have demonstrated that such objets pulsates in non-radial g-modes with eigenperiods in the range 100-2000 sec.

  17. On the impact of using downscaled reanalysis data instead of direct measurements for modeling the mass balance of a tropical glacier (Cordillera Blanca, Peru)

    NASA Astrophysics Data System (ADS)

    Galos, Stephan; Hofer, Marlis; Marzeion, Ben; Mölg, Thomas; Großhauser, Martin

    2013-04-01

    Due to their setting, tropical glaciers are sensitive indicators of mid-tropospheric meteorological variability and climate change. Furthermore these glaciers are of particular interest because they respond faster to climatic changes than glaciers located in mid- or high-latitudes. As long-term direct meteorological measurements in such remote environments are scarce, reanalysis data (e.g. ERA-Interim) provide a highly valuable source of information. Reanalysis datasets (i) enable a temporal extension of data records gained by direct measurements and (ii) provide information from regions where direct measurements are not available. In order to properly derive the physical exchange processes between glaciers and atmosphere from reanalysis data, downscaling procedures are required. In the present study we investigate if downscaled atmospheric variables (air temperature and relative humidity) from a reanalysis dataset can be used as input for a physically based, high resolution energy and mass balance model. We apply a well validated empirical-statistical downscaling model, fed with ERA-Interim data, to an automated weather station (AWS) on the surface of Glaciar Artesonraju (8.96° S | 77.63° W). The downscaled data is then used to replace measured air temperature and relative humidity in the input for the energy and mass balance model, which was calibrated using ablation data from stakes and a sonic ranger. In order to test the sensitivity of the modeled mass balance to the downscaled data, the results are compared to a reference model run driven solely with AWS data as model input. We finally discuss the results and present future perspectives for further developing this method.

  18. 78 FR 77096 - Newspapers Used for Publication of Legal Notices in the Southwestern Region, Which Includes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... Mexico. Rita Blanca National Grassland in Cimarron County, Oklahoma notices published in:--``Boise City News'', Boise City, Oklahoma. Rita Blanca National Grassland in Dallam County, Texas notices published...:--``Union County Leader'', Clayton, New Mexico. Rita Blanca National Grassland in Cimarron County,...

  19. 77 FR 73412 - Newspapers Used for Publication of Legal Notices in the Southwestern Region, Which Includes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-10

    ... in:--``Union County Leader'', Clayton New Mexico. Rita Blanca National Grassland in Cimarron County, Oklahoma notices published in:--``Boise City News'', Boise City, Oklahoma. Rita Blanca National Grassland... Mexico published in:--``Union County Leader'', Clayton, New Mexico. Rita Blanca National Grassland...

  20. Osservazioni radio di Giove durante gli impatti della cometa Shoemaker-Levy 9.

    NASA Astrophysics Data System (ADS)

    Bressan, G.

    1994-10-01

    Jupiter's decametric radio emissions lowered during the week interested by the comet impacts. Each event was preceded, as loss frequently followed, by outbursts which increased the radio emission between three and four times the ground noise.

  1. Studio morfologico della cometa P/Swift-Tuttle durante l'apparizione del 1992.

    NASA Astrophysics Data System (ADS)

    Favero, G.; Favero, G.; Milani, G. A.

    1996-02-01

    The study of hundreds visual, photographic and CCD observations of comet 109P/Swift-Tuttle made by amateurs and mostly published in popular magazines allowed the authors to estimate the expansion velocities of the coma and the behaviour of the plasma tail. The photometric and morphologic behaviour is accounted for by a monolithic nucleus, rotating in 2.92 d and erupting gas and dust from three restricted areas of its surface.

  2. Usando el Periodico durante el desarollo (Growing Up Using the Newspaper: Ideas for Parents).

    ERIC Educational Resources Information Center

    Becher, Nancy A.

    Written for parents, this guide offers suggestions for using the newspaper at home to practice reading skills, to discover new information, and to teach critical reading. Activities in the guide are arranged according to grade level (kindergarten through grade two, grades one through three, grades four through six, and grades seven through twelve)…

  3. Actividad cometaria en 2060 Chiron durante un mínimo de brillo

    NASA Astrophysics Data System (ADS)

    Cellone, S. A.; Silva, A. M.

    A decade after its discovery in 1977 and its classification as an asteroid with the number 2060, Chiron began to show evidences of cometary activity at ~ 13 AU from the Sun. Since then, it has been the target of several studies due to its particular orbital and astrophysical behavior, which are unusual both for an asteroid and for a comet. We present here results from direct CCD observations obtained between 1996 and 1998 with the 2.15 m ``Jorge Sahade'' telescope (San Juan, Argentina). Chiron's absolute magnitude was then very near its historical minimum; however, cometary activity was unequivocally detected from its surface brightness profiles (SBP) as well as directly from co-added images. This sets an upper limit to the nuclear brightness of this object. Conclusions about the dynamical state of the dust coma are obtained from the analysis of the SBPs slopes, while the possible gas emission is studied through narrow-band imaging. Integrated photometry shows a ~ 0.08 mag decline in 1 hour in agreement with the rotational light-curve of the nucleus, although its amplitude is larger than all published values, probably due to a smaller dilution by the coma.

  4. La cometa 9P Tempel 1 nell'apparizione 2005. Monitoraggio durante la fase di impatto della missione Deep Impact

    NASA Astrophysics Data System (ADS)

    Milani, Giannantonio; Sostero, Giovanni; Trabatti, Roberto; Vinante, Carlo

    2006-06-01

    Comet 9P/Tempel 1 was constantly monitored during the 2005 apparition by observers participating in the CARA project (http://cara.uai.it). R and I (Cousins), as well as 647-650 nm narrowband filter photometric data were used to produce Afrho quantity measuremnts. Afrho value peaked about 300 cm approximately 83 days before perihelion, with a general behaviour that closely matches the one of previous apparitions. Around the time of the impact of the Deep Impact module a short temporary increase was detected, but Afrho values and the coma profile returned to a normal state within approximately 3 days. The dust cloud produced by the impact was clearly seen in the images obtained on July 4 and 5 as well as a temporary disturbance in the average photometric profile in the coma. No permanent long-time effects were detected in the average Afrho behaviour, which matches the trend observed in previous apparitions fairly well.

  5. History of the USDA-ARS Watershed, Water Resources and Climate Research at Chickasha, Durant, and El Reno, Oklahoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The watershed, water resources and climate research conducted at the Great Plains Agroclimate and Natural Resources Research Unit at the USDA, ARS Grazinglands Research Laboratory in El Reno, Oklahoma, is rooted in events reaching as far back as the Dust Bowl and the Great Depression. In this narrat...

  6. Fumar durante el tratamiento de cáncer (PDQ®)—Versión para pacientes

    Cancer.gov

    Resumen de información revisada por expertos acerca de la influencia de seguir fumando sobre el tratamiento del cáncer y el riesgo de segundos cánceres. Se mencionan las intervenciones que estimulan dejar el hábito de fumar.

  7. Monitoreo óptico de eta-Carina durante el pasaje por el periastro en 2014.6

    NASA Astrophysics Data System (ADS)

    Fernández-Lajús, E.; Salerno, N. E.; Scalia, M. C.; Ramos, X. S.; Giudici, F. N.; Gamen, R. C.

    2015-08-01

    We present the H light curves resulting from the 2013 and 2014 observing seasons of Car as well as its spectral evolution, including the latest ``event'' occurred in mid-2014. The direct CCD observations were made with the telescope ``VS Niemela'' the Observatory of La Plata, and spectroscopic observations were made with the telescope ``J. Sahade'' of Casleo, Argentina.

  8. Fasi fenologiche di Cupressus Sempervirens all'IIS Caffè, a Roma durante l'inverno 2016

    NASA Astrophysics Data System (ADS)

    Sigismondi, Costantino; Ricciardi, Lorenzo

    2016-05-01

    The phenology of 10 trees of Cupressus Sempervirens has been monitored weekly during the winter 2016. In the month of February 2016 all pollinations occurred for our sample trees near new Moon and last quarter.

  9. Fumar durante el tratamiento de cáncer (PDQ®)—Versión para profesionales de salud

    Cancer.gov

    Resumen de información revisada por expertos acerca de la influencia de seguir fumando sobre el tratamiento del cáncer y el riesgo de segundos cánceres. Se mencionan las intervenciones que estimulan dejar el hábito de fumar.

  10. Hospitalization Cost Offset of a Hostility Intervention for Coronary Heart Disease Patients

    ERIC Educational Resources Information Center

    Davidson, Karina W.; Gidron, Yori; Mostofsky, Elizabeth; Trudeau, Kimberlee J.

    2007-01-01

    The authors evaluated hospitalization cost offset of hostility management group therapy for patients with coronary heart disease (CHD) from a previously published randomized controlled trial (Y. Gidron, K. Davidson, & I. Bata, 1999). Twenty-six male patients with myocardial infarction or unstable angina were randomized to either 2 months of…

  11. Open-field host specificity test of Gratiana boliviana (Coleoptera: Chrysomelidae), a biological control agent of tropical soda apple (Solanaceae) in the United States

    SciTech Connect

    Gandolfo, D.; McKay, F.; Medal, J.C.; Cuda, J.P.

    2007-03-15

    An open-field experiment was conducted to assess the suitability of the South American leaf feeding beetle Gratiana boliviana Spaeth for biological control of Solanum viarum Dunal in the USA. An open-field test with eggplant, Solanum melongena L., was conducted on the campus of the University of Buenos Aires, Argentina, and a S. viarum control plot was established 40 km from the campus. One hundred adult beetles were released in each plot at the beginning of the experiment during the vegetative stage of the plants, and forty additional beetles were released in the S. melongena plot at the flowering stage. All the plants in each plot were checked twice a week and the number of adults, immatures, and eggs recorded. Results showed almost a complete rejection of eggplant by G. boliviana. No noticeable feeding damage was ever recorded on eggplant. The experiment was ended when the eggplants started to senesce or were severely damaged by whiteflies and spider mites. The results of this open-field experiment corroborate previous quarantine/laboratory host-specificity tests indicating that a host range expansion of G. boliviana to include eggplant is highly unlikely. Gratiana boliviana was approved for field release in May 2003 in the USA. To date, no non-target effects have been observed either on eggplant or native species of Solanum. (author) [Spanish] Una prueba de campo fue conducida para evaluar la especificidad del escarabajo suramericano defoliador Gratiana boliviana Spaeth para control biologico de Solanum viarum Dunal en los Estados Unidos. La prueba con berenjena se realizo en el campo experimental de la Universidad de Buenos Aires, Argentina, y una parcela control con S. viarum fue establecida a 40 km. Cien escarabajos adultos fueron liberados en cada parcela al inicio del experimento durante la fase vegetativa, y cuarenta escarabajos adicionales fueron liberados en la parcela de berenjena durante la floracion. Todas las plantas en cada parcela fueron

  12. 9. Photographic copy of photograph. (Source: U.S. Department of Interior. ...

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

    9. Photographic copy of photograph. (Source: U.S. Department of Interior. Office of Indian Affairs. Indian Irrigation Service. Annual Report, Fiscal Year 1928 Vol I. Irrigation District #4, California and Southern Arizona, RG 75, BIA-Phoenix, Box 40, National Archives, Pacific Southwest Region) Photographer unknown. CASA BLANCA CANAL, HEADING AND FLUME, APRIL 10, 1928 - San Carlos Irrigation Project, Casa Blanca Canal, Gila River, Coolidge, Pinal County, AZ

  13. 10. Photographic copy of photograph. (Source: U.S. Department of Interior. ...

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

    10. Photographic copy of photograph. (Source: U.S. Department of Interior. Office of Indian Affairs. Indian Irrigation Service. Annual Report, Fiscal Year 1928. Vol I. Irrigation District #4, California and Southern Arizona, RG 75, BIA-Phoenix, Box 40, National Archives, Pacific Southwest Region) Photographer unknown. CASA BLANCA CANAL, HEADING AND FLUME, APRIL 10, 1928 - San Carlos Irrigation Project, Casa Blanca Canal, Gila River, Coolidge, Pinal County, AZ

  14. Mediciones de irradiancia solar y capa de ozono durante el eclipse de Sol de 1994 en el Observatorio Astronómico de Rosario, Argentina

    NASA Astrophysics Data System (ADS)

    Piacentini, R. D.; Micheletti, M. I.

    We show results of measurements made during the Sun's eclipse of November 3, 1994, in Observatorio Astronómico de Rosario (32o 57' S, 60o 37' W, 25 m a.s.l.). The eclipse begin at 8:41 local hour, reached its maximum with 77% of the surface covered at 9:51 and finished at 11:04. The direct solar irradiance of 300 nm and 313 nm were able to be measured, due to the fact that during the whole period the sky remained completed uncovered (zero percent cloudiness). The measurements were made with the portable ozonometer developed by Tocho and co-workers. They show the characterictic decrease due to the occultation of the source, which is approximately proportional to the surface's diminution. When crossing the earth's atmosphere to arrive to the observation point, these irradiances are affected mainly by the ozone layer, specially the irradiance at lower wavelength, what let it to determine by comparison the thickness of this layer. The total ozone thickness distributed between the troposphere and the stratosphere shows an oscillation, whose amplitude, since the occurence of the maximum of occulation, has a mean value of 4%, and whose period is of approximately 2100 seconds, being both numbers considerably larger than the ones registred by Mims III y Mims (Geophysical Research Letters, 20, 367, 1993) during the eclipse of July 11, 1991 and by Tocho, Da Silva y Rivas (XVIII Quadriennial Ozone Symposiom, Italy, September, 1996) during the same eclipse analyzed in the present work, but observed in Salta. As complementary results, we measured the global irradiance and the ambient temperature during this astronomical event.

  15. La Educacion de los Jesuitas en Cuba durante el Siglo XVI (1566-1574) (Jesuit Education in Cuba during the 16th Century (1566-1574).

    ERIC Educational Resources Information Center

    Puentes, Roberto Valdes

    2000-01-01

    Explains the relationship between Spanish colonialism in Cuba, evangelization of the Indians, and the origins of Cuban culture, as well as the role the Jesuits played in this process of transculturation. Analyzes the first phase in the history of the educational work of the Jesuits in Cuba (1566-1574). (BT)

  16. La Educacion en America Latina y El Caribe Durante Los Proximos 25 Anos. (Education in Latin America and the Caribbean during the Next 25 Years.)

    ERIC Educational Resources Information Center

    Roggi, Luis Osvaldo, Ed.

    1987-01-01

    The nine papers appearing in this document review both limitations and progress in education in Latin America, study the future of education in Latin America and the Caribbean, and make recommendations to the Regional Program for Educational Development (PREDE). There is, in addition, a lengthy transcription of a discussion, among eight of the…

  17. During Her Pregnancy, Kathy Prepares for Breastfeeding. Mother-to-Mother Support = Durante Su Embarazo, Josefa Se Prepara para la Lactancia. Apoyo Madre a Madre.

    ERIC Educational Resources Information Center

    Magalhaes, Rebecca; Stone-Jimerez, Maryanne; Allen de Smith, Paulina; Smith, Natalia

    These magazine-sized booklets, one in English, one in Spanish, are in a cartoon format and designed to be used by people with limited literacy in English or Spanish. They explain the importance of both prenatal care and breastfeeding. (Adjunct ERIC Clearinghouse for ESL Literacy Education) (KFT)

  18. CHOQUES AGREGADOS E INVERSIÓN EN CAPITAL HUMANO: EL LOGRO EDUCATIVO SUPERIOR DURANTE LA DÉCADA PERDIDA EN MÉXICO

    PubMed Central

    Peña, Pablo A.

    2014-01-01

    Este artículo documenta una respuesta agregada negativa del logro educativo superior (más de 12 años de escolaridad) en México a la recesión de 1982–83 y el estancamiento que le siguió. La respuesta no fue homogénea entre géneros, regiones y entornos familiares. Los hombres experimentaron una caída en el logro mientras que las mujeres experimentaron un crecimiento más lento. En promedio, los estados con un mayor logro antes del choque experimentaron mayores caídas. La respuesta entre distintos entornos familiares no presenta un patrón claro. Sin embargo, el efecto negativo en el logro se observa incluso entre hermanos. La evidencia sugiere una historia por el lado de la demanda: la caída en el ingreso de los hogares parece ser el determinante de la caída/desaceleración del logro educativo superior. La conclusión es que la recesión y la falta de crecimiento que le siguió tuvieron un efecto negativo importante y duradero en la formación de capacidades en México. PMID:25328251

  19. NSR&D FY14 Final Report: Friction/Impact Modeling

    SciTech Connect

    Zhang, Duan Zhong; Ma, Xia; Giguere, Paul T.

    2014-09-19

    The LANL-developed CartaBlanca code uses advanced techniques, including the Dual Domain Material Point (DDMP) method, to calculate fluid, solid motions and fluid-structure interactions. In the last year we have implemented the ViscoSCRAM material model in CartaBlanca based on Clements’ Abaqus-Explicit Finite Element implementation. In this fiscal year, we study numerical properties of this implementation. To consider coupled mechanical, thermal and chemical effects, we have implemented Henson’s HE decomposition model to couple with the thermal and mechanical packages in CartaBlanca. We have also developed porous media flow modules to consider heat convection effects of the reaction product gas inside pores of HE. The next immediate step is to perform numerical simulations to study interactions among these different mechanisms. We have started such calculation and obtained interesting initial results at the end of this fiscal year.

  20. Flight data acquisition methodology for validation of passive ranging algorithms for obstacle avoidance

    NASA Technical Reports Server (NTRS)

    Smith, Phillip N.

    1990-01-01

    An account is given of the methodology used to develop a data base containing low altitude imagery, augmented with the rotorcraft and sensor parameters required for passive-range estimation. The bata base is predicated on flight test data encompassing imagery, rotorcraft and sensor parameters, and ground truth range measurements. Data preparation was conducted by means of a novel technique for obtaining the sensor-calibration parameters. The data-base thus obtained will facilitate further development of computer vision-based obstacle-detection and passive range-estimation algorithms, as well as furnish a benchmark for verification of range estimates against ground-truth estimates.

  1. Como ayudar a su hijo durante la edad preescolar, con actividades para los ninos desde el nacimiento hasta los 5 anos (Helping Your Preschool Child, with Activities for Children from Infancy through Age 5).

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC. Office of Intergovernmental and Interagency Affairs.

    The first 5 yeas of a child's life are a time of tremendous physical, emotional, social, and cognitive growth. Noting that research shows that children are more likely to succeed in learning when their families actively support them, this Spanish-language booklet is intended for families and caregivers who want to help their preschool children…

  2. Como ayudar a su hijo durante los primeros anos de la adolescencia: Para los padres con ninos entre las edades de 10 a 14 anos (Helping Your Child through Early Adolescence: For Parents of Children from 10 through 14).

    ERIC Educational Resources Information Center

    Paulu, Nancy

    Recognizing that parents and families can greatly influence the development of their 10- through 14-year-olds, this Spanish-language booklet is part of a national effort to provide parents with the latest research and practical information to help them support their children both at home and in school. The booklet is organized in 13 sections…

  3. Ideologies Revealed during the Construction of Meaning in an EFL Class (Ideologías reveladas durante la construcción de significado en una clase de inglés como lengua extranjera)

    ERIC Educational Resources Information Center

    Fajardo Mora, Néstor Ricardo

    2014-01-01

    This article reports on an interpretive qualitative study conducted at a public university in Bogotá with 26 pre-service social studies teachers. It is focused on unveiling which ideologies are discovered when they construct the meaning of texts through text-based tasks in an English as a foreign language class. The data were collected by using…

  4. Comparison of Life Cycle Costs for LLRW Management in Texas

    SciTech Connect

    Baird, R. D.; Rogers, B. C.; Chau, N.; Kerr, Thomas A

    1999-08-01

    This report documents a comparison of life-cycle costs of an assured isolation facility in Texas versus the life-cycle costs for a traditional belowground low-level radioactive waste disposal facility designed for the proposed site near Sierra Blanca, Texas.

  5. eLearning--Theories, Design, Software and Applications

    ERIC Educational Resources Information Center

    Ghislandi, Patrizia, Ed.

    2012-01-01

    Chapters in this book include: (1) New e-Learning Environments: e-Merging Networks in the Relational Society (Blanca C. Garcia); (2) Knowledge Building in E-Learning (Xinyu Zhang and Lu Yuhao); (3) E-Learning and Desired Learning Outcomes (Ralph Palliam); (4) Innovative E-Learning Solutions and Environments for Small and Medium Sized Companies…

  6. Phytochemical Composition, Anti-inflammatory, and Antiproliferative Activity of Whole Wheat Flour

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Five wheat cultivars (Macon, Louise, WestBred 936, Alpowa, and Blanca Grande) were evaluated for phenolics composition, carotenoid, and tocopherol composition, anti-inflammatory activity, and antiproliferative activity against HT-29 cells. Total ferulic acid ranged from 451.7-731.3 µg/g , with the ...

  7. Release of ‘UI Platinum’ hard white spring wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘UI Platinum’ (Reg. No. CV------, PI 672533) hard white spring wheat (Triticum aestivum L.) was developed by the Idaho Agricultural Experiment Station and released in 2014. UI Platinum was derived from the cross ‘Blanca Grande’ x ‘Jerome’ and tested under experimental numbers A01178S, IDO694, and I...

  8. 77 FR 56840 - Environmental Impacts Statements; Notice of Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-14

    ... 202-493-6381. Revision to FR Notice Published 07/20/2012; Extending Comments Period from 09/20/2012 to..., Rita Blanca, Black Kettle, and McClellan Creek National Grasslands Land and Resource Management Plan... Activity Bethesda, Montgomery County, MD, Comment Period Ends: 10/29/2012, Contact: Joseph Macri 301-...

  9. Darwin’s legacy to rove beetles (Coleoptera, Staphylinidae): A new genus and a new species, including materials collected on the Beagle’s voyage

    PubMed Central

    Chatzimanolis, Stylianos

    2014-01-01

    Abstract A species of xanthopygine rove beetles is described and figured here as Darwinilus sedarisi gen. n. and sp. n. The holotype was collected by Charles Darwin in Bahía Blanca, Argentina on the Beagle’s voyage. The contributions of Charles Darwin to rove beetle systematics are summarized briefly. PMID:24574856

  10. Life-Cycle Cost Study for a Low-Level Radioactive Waste Disposal Facility in Texas

    SciTech Connect

    B. C. Rogers; P. L. Walter; R. D. Baird

    1999-08-01

    This report documents the life-cycle cost estimates for a proposed low-level radioactive waste disposal facility near Sierra Blanca, Texas. The work was requested by the Texas Low-Level Radioactive Waste Disposal Authority and performed by the National Low-Level Waste Management Program with the assistance of Rogers and Associates Engineering Corporation.

  11. "My Student Was Apprehended by Immigration": A Civics Teacher's Breach of Silence in a Mixed-Citizenship Classroom

    ERIC Educational Resources Information Center

    Darbach, Dafney Blanca

    2015-01-01

    In this article, Dafney Blanca Dabach investigates how teachers and their students of different citizenship statuses navigate tensions in formal state-sponsored citizenship education. In traditional US high school civics courses, undocumented immigrant youths' liminal status is often invisible and overlooked as undocumented youth are educated…

  12. Malaria transmission in two localities in north-western Argentina

    PubMed Central

    Dantur Juri, María J; Zaidenberg, Mario; Claps, Guillermo L; Santana, Mirta; Almirón, Walter R

    2009-01-01

    Background Malaria is one of the most important tropical diseases that affects people globally. The influence of environmental conditions in the patterns of temporal distribution of malaria vectors and the disease has been studied in different countries. In the present study, ecological aspects of the malaria vector Anopheles (Anopheles) pseudopunctipennis and their relationship with climatic variables, as well as the seasonality of malaria cases, were studied in two localities, El Oculto and Aguas Blancas, in north-western Argentina. Methods The fluctuation of An. pseudopunctipennis and the malaria cases distribution was analysed with Random Effect Poisson Regression. This analysis takes into account the effect of each climatic variable on the abundance of both vector and malaria cases, giving as results predicted values named Incidence Rate Radio. Results The number of specimens collected in El Oculto and Aguas Blancas was 4224 (88.07%) and 572 (11.93%), respectively. In El Oculto no marked seasonality was found, different from Aguas Blancas, where high abundance was detected at the end of spring and the beginning of summer. The maximum mean temperature affected the An. pseudopunctipennis fluctuation in El Oculto and Aguas Blancas. When considering the relationship between the number of malaria cases and the climatic variables in El Oculto, maximum mean temperature and accumulated rainfall were significant, in contrast with Aguas Blancas, where mean temperature and humidity showed a closer relationship to the fluctuation in the disease. Conclusion The temporal distribution patterns of An. pseudopunctipennis vary in both localities, but spring appears as the season with better conditions for mosquito development. Maximum mean temperature was the most important variable in both localities. Malaria cases were influenced by the maximum mean temperature in El Oculto, while the mean temperature and humidity were significant in Aguas Blancas. In Aguas Blancas peaks of

  13. Water Resources in a Peruvian Mountain Watershed: Hydrochemical Tracing of Groundwater and Glacier Meltwater Impact on Streamflow

    NASA Astrophysics Data System (ADS)

    McKenzie, J. M.; Mark, B. G.

    2005-12-01

    The Callejon de Huaylas, Peru, is a large (~5000 km2; elevation range from ~1800 to 1650 masl) drainage basin for the Rio Santa, which is fed by the glacierized Cordillera Blanca and the non-glacierized Cordillera Negra. The region is well-populated, with extensive agricultural diversity and natural resources, but currently receding glaciers are threatening the future water supply. During the dry season (May to September) glacial melt water from the Cordillera Blanca partially buffers stream-flow, although the magnitude of this effect is not easily measured. We attempt to evaluate the relative contribution of glacier meltwater and groundwater to the regional stream discharge, from 1st order basins to the whole watershed. In July, 2004 and July, 2005 we collected 89 water samples from streams, springs, and groundwater within the Callejon de Huaylas and analyzed for major dissolved ions and the isotopes of oxygen and hydrogen. The water generally has a Ca-Mg-HCO3 chemical signal, consistent with the regional geology. Preliminary δ18O and δD values range from -15.6‰ to -4.9‰ and -113‰ to -51.3‰ respectively. Transects of surface water samples from Cordillera Blanca glaciers to the Rio Santa show isotopic enrichment with lower elevation. We sampled 14 groundwater wells and springs, and found the isotopic composition of the water to be isotopically enriched and very similar to surface water within the Cordillera Negra. The Rio Santa is a mixture of Cordillera Blanca and Cordillera Negra surface waters, and the down gradient transect becomes relatively depleted with lower elevation, possibly due to the distribution of glacier mass in the Cordillera Blanca. This research is the beginning of a long term water sampling and monitoring program to identify unique geochemical end-members for quantification of glacier meltwater and groundwater contributions and to assess changes in the hydrologic balance within the Callejon de Huaylas as a result of glacier recession.

  14. Synthesis, structure and photoluminescence properties of Ho3+ doped TTB-BaTa2O6 phosphors

    NASA Astrophysics Data System (ADS)

    İlhan, Mustafa

    2014-12-01

    Ho3+ doped TTB-BaTa2O6 phosphors were produced by the solid state reaction method. XRD analysis confirmed the formation of BaTa2O6 single phase which was accomplished by heat treatment at 1425 °C for 20 h. The crystal structure of TTB-BaTa2O6 allowed doping concentration of Ho3+ ions up to 10 mol%, maintaining a single phase composition. A second phase of HoTaO4 begins to appear at 15 mol%. The lattice structure and the crystallite sizes changed with the concentration of Ho3+. In SEM analysis, it was also shown that BaTa2O6 grain sizes changed with the concentration of Ho3+. EDS analysis revealed that the Ta/Ba ratio increased on the grains depending on Ho3+ concentration. Charge balance of the structure was formulated through the EDS results. In fluorometer analysis, a strong green emission (λem = 546.9 nm) was observed in the visible spectral region. The emission increased with the doping concentration of up to 2.5 mol%, and above this level decreased due to concentration quenching.

  15. Chapman Conference on Sediment Transport Processes in Estuaries

    NASA Astrophysics Data System (ADS)

    Perillo, Gerardo M. E.; Lavelle, J. William

    During the week of June 13-17, 1988, 72 sediment transport researchers “aggregated” at the Universidad Nacional del Sur in Bahfa Blanca, Argentina, to participate in an AGU Chapman Conference on Sediment Transport Processes in Estuaries. The main goals of the meeting were to discuss recent advances in estuarine science, to appraise promising future research directions, and to develop contacts and establish working relationships between Latin American and non-Latin- American estuarine researchers. The meeting drew participants from Argentina, Brazil, Chile, Uruguay, Venezuela, the U.S., Canada, Britain, France, the Federal Republic of Germany, The Netherlands, and South Africa. Meeting cosponsors were UNESCO, Secretaria de Ciencía y Técnica, Consejo Nacional de Investigaciones Cientificas y Técnicas, Comision de Investigaciones Cientificas de la Provincia de Buenos Aires, Universidad del Sur, Municipalidad de Bahia Blanca, Asociaciôn Argentina de Geofisicos y Geodestas (AGU sister organization), and the Instituto Argentino de Oceanografia (IADO).

  16. A study of microseismicity in northern Baja California, Mexico

    NASA Technical Reports Server (NTRS)

    Johnson, T. L.; Koczynski, T.; Madrid, J.

    1976-01-01

    Five microearthquake instruments were operated for 2 months in 1974 in a small mobile array deployed at various sites near the Agua Blanca and San Miguel faults. An 80-km-long section of the San Miguel fault zone is presently active seismically, producing the vast majority of recorded earthquakes. Very low activity was recorded on the Agua Blanca fault. Events were also located near normal faults forming the eastern edge of the Sierra Juarez suggesting that these faults are active. Hypocenters on the San Miguel fault range in depth from 0 to 20 km although two-thirds are in the upper 10 km. A composite focal mechanism showing a mixture of right-lateral and dip slip, east side up, is similar to a solution obtained for the 1956 San Miguel earthquake which proved consistent with observed surface deformation.

  17. Geologic evaluation of remote sensing data, site 157, Awza-Borrego Desert, California

    NASA Technical Reports Server (NTRS)

    Wolfe, E. W.

    1969-01-01

    Remote sensing data were obtained at site 157 in May 1968 under mission 73 of the NASA aircraft program. The site is located in an area of high temperatures and extreme aridity immediately west of the Imperial Valley, Southern California. Site 157 is partially surrounded by pre-Cenozoic crystalline rocks exposed in the Fish Creek, Vallecito, and Tierra Blanca Mountains. The study area itself is underlain by more than 20,000 feet of sedimentary strata of late Cenozoic age.

  18. Seven New Bulk Chemical Analyses of Aubrites

    NASA Astrophysics Data System (ADS)

    Easton, A. J.

    1985-09-01

    New bulk chemical analyses are given of Aubres, Bishopville, Bustee, Khor Temiki, Norton County, Peña Blanca Spring and Shallowater. Selective attack by dry chlorine (350°C) on magnetic and non-magnetic fractions was used to determine the distribution of some normally lithophile elements (Al, Ca, Cr, K, Mg, Mn, Na, P and Ti) between silicate and sulphide groups of minerals.

  19. Revision of the South American window fly genus Heteromphrale Kröber, 1937 (Diptera, Scenopinidae)

    PubMed Central

    Winterton, Shaun L.; Gaimari, Stephen D.

    2011-01-01

    Abstract The Neotropical window fly genus Heteromphrale Kröber, 1937 is revised. Two previously described species (Heteromphrale chilensis (Kröber, 1937) and Heteromphrale cyanops (Edwards, 1932)) are redescribed while a new species (Heteromphrale blanca sp. n.) is described from Argentina. The male of Heteromphrale chilensis and female of Heteromphrale cyanops are described and figured for the first time, and a key to species is presented. PMID:21594165

  20. Geologic structure and tectonics of inner continental borderland of northern Baja California

    SciTech Connect

    Legg, M.R.; Victor, W.O.; Francisco, S.V.

    1987-05-01

    Detailed marine geophysical surveys of the inner California continental borderland west of northern Baja California show that the region is underlain by two major, northwest-trending, Quaternary, dextral wrench fault systems. The San Clemente fault system lies along the western part of the inner borderland and is delineated by the San Clemente and San Isidro fault zones. Together, these fault zones connect to form a long (300 km), narrow (5-10 km), continuous zone of faulting that is very similar to the larger San Andreas fault system onshore. The Agua Blanca fault system is a complex zone of shear delineated by three or more subparallel wrench fault zones in the eastern part of the inner borderland. The westernmost San Diego Trough-Bahia Soledad fault zone consists of relatively long (50 km), continuous, main fault traces which cut the Quaternary sediments of the nearshore basin trough. The Coronado Bank-Agua Blanca fault zone is more complicated, with numerous discontinuous, subparallel, right- and left-stepping, anastomosing fault traces which are associated with significant structural relief. A nearshore zone of faults, marked by the Newport-Inglewood-Rose Canyon fault zone in the north and the Estero-Descanso fault zone in the south, parallels the coast and defines the eastern boundary of the California continental borderland structural province. All of these eastern fault zones merge into the transpeninsular Agua Blanca fault, and their N30/sup 0/W trend differs substantially from the trend of the major peninsular ranges fault zones.

  1. Variations in macrobenthic community structure in relation to changing environmental conditions in sandy beaches of Argentina

    NASA Astrophysics Data System (ADS)

    Carcedo, M. Cecilia; Fiori, Sandra M.; Piccolo, M. Cintia; López Abbate, M. Celeste; Bremec, Claudia S.

    2015-12-01

    This study describes for the first time the intertidal macrobenthic community of exposed sandy beaches located near the Bahía Blanca Estuary (38°S) and reports the physical characterization of this coastal fringe. The main objective of the study was to link environmental variables to biotic information, analyzing the results in the context of the Swash Exclusion Hypothesis (SEH) and possible estuarine influence. Four beaches were sampled seasonally at different distances from the mouth of the Bahía Blanca Estuary. To characterize the morphodynamic state of the beaches, the Dean parameter (Ω) was calculated. Multivariate analyses were used to assess benthic community structures and their relationships with physical variables. The two beaches located closest to the Bahía Blanca Estuary were classified as intermediate and those located further from the estuary as dissipative. Richness, diversity and biomass of intertidal macrobenthic communities varied with the SEH, increasing towards the dissipative beaches. However, total density was higher on intermediate beaches, possibly because of nutrient-rich silt-clay sediment input from the estuary, enabling them to maintain a higher density of organisms than dissipative beaches. The estuary acts as a moderator of habitat hardness, which together with the morphodynamic state of the beaches is an important factor in the structuring of the macrobenthic community along this coastal fringe.

  2. Late Pleistocene equilibrium-line reconstructions in the northern Peruvian Andes

    USGS Publications Warehouse

    Rodbell, D.T.

    1992-01-01

    ELA reconstructions using the toe-to-headwall-altitude ratio method for paleoglaciers in the Cordilleras Blanca and Oriental, northern Peruvian Andes indicate that ELAs during the last glacial maximum (LGM; marine isotope stage 2)) were c.4300 m in the Cordillera Blanca, c.3900-3600 m on the west side of the Cordillera Oriental, and c.3200 m on the east (Amazon Basin) side of the Cordillera Oriental. Comparison with estimated modern ELAs and glaciation thresholds indicate that ELA depression ranged from c.700 m in the Cordillera Blanca to c.1200 m on the east side of the Cordillera Oriental. Palynological evidence for drier conditions during the LGM in the tropical Andes suggests that ELA depression of this amount involved a temperature reduction (>5-6??C) that greatly exceeded the tropical sea-surface temperature depression estimates of CLIMAP (<2??C). The west to east increase in ELA depression during the LGM indicates that the steep modern precipitation gradients may have been even steeper during the LGM. -from Author

  3. Satellite-derived NDVI, LST, and climatic factors driving the distribution and abundance of Anopheles mosquitoes in a former malarious area in northwest Argentina.

    PubMed

    Dantur Juri, María Julia; Estallo, Elizabet; Almirón, Walter; Santana, Mirta; Sartor, Paolo; Lamfri, Mario; Zaidenberg, Mario

    2015-06-01

    Distribution and abundance of disease vectors are directly related to climatic conditions and environmental changes. Remote sensing data have been used for monitoring environmental conditions influencing spatial patterns of vector-borne diseases. The aim of this study was to analyze the effect of the Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS), and climatic factors (temperature, humidity, wind velocity, and accumulated rainfall) on the distribution and abundance of Anopheles species in northwestern Argentina using Poisson regression analyses. Samples were collected from December, 2001 to December, 2005 at three localities, Aguas Blancas, El Oculto and San Ramón de la Nueva Orán. We collected 11,206 adult Anopheles species, with the major abundance observed at El Oculto (59.11%), followed by Aguas Blancas (22.10%) and San Ramón de la Nueva Orán (18.79%). Anopheles pseudopunctipennis was the most abundant species at El Oculto, Anopheles argyritarsis predominated in Aguas Blancas, and Anopheles strodei in San Ramón de la Nueva Orán. Samples were collected throughout the sampling period, with the highest peaks during the spring seasons. LST and mean temperature appear to be the most important variables determining the distribution patterns and major abundance of An. pseudopunctipennis and An. argyritarsis within malarious areas. PMID:26047182

  4. New generalized poisson mixture model for bimodal count data with drug effect: An application to rodent brief-access taste aversion experiments.

    PubMed

    Sheng, Y; Soto, J; Orlu Gul, M; Cortina-Borja, M; Tuleu, C; Standing, J F

    2016-08-01

    Pharmacodynamic (PD) count data can exhibit bimodality and nonequidispersion complicating the inclusion of drug effect. The purpose of this study was to explore four different mixture distribution models for bimodal count data by including both drug effect and distribution truncation. An example dataset, which exhibited bimodal pattern, was from rodent brief-access taste aversion (BATA) experiments to assess the bitterness of ascending concentrations of an aversive tasting drug. The two generalized Poisson mixture models performed the best and was flexible to explain both under and overdispersion. A sigmoid maximum effect (Emax ) model with logistic transformation was introduced to link the drug effect to the data partition within each distribution. Predicted density-histogram plot is suggested as a model evaluation tool due to its capability to directly compare the model predicted density with the histogram from raw data. The modeling approach presented here could form a useful strategy for modeling similar count data types. PMID:27472892

  5. New generalized poisson mixture model for bimodal count data with drug effect: An application to rodent brief‐access taste aversion experiments

    PubMed Central

    Soto, J; Orlu Gul, M; Cortina‐Borja, M; Tuleu, C; Standing, JF

    2016-01-01

    Pharmacodynamic (PD) count data can exhibit bimodality and nonequidispersion complicating the inclusion of drug effect. The purpose of this study was to explore four different mixture distribution models for bimodal count data by including both drug effect and distribution truncation. An example dataset, which exhibited bimodal pattern, was from rodent brief‐access taste aversion (BATA) experiments to assess the bitterness of ascending concentrations of an aversive tasting drug. The two generalized Poisson mixture models performed the best and was flexible to explain both under and overdispersion. A sigmoid maximum effect (Emax) model with logistic transformation was introduced to link the drug effect to the data partition within each distribution. Predicted density‐histogram plot is suggested as a model evaluation tool due to its capability to directly compare the model predicted density with the histogram from raw data. The modeling approach presented here could form a useful strategy for modeling similar count data types. PMID:27472892

  6. Importance of Viscoelastic Property Measurement of a New Hydrogel for Health Care

    NASA Astrophysics Data System (ADS)

    Roy, Niladri; Saha, Nabanita; Kitano, Takeshi; Saha, Petr

    2009-07-01

    A simple technology based new hydrogel "PVP-CMC-BA" has been prepared by the scientists of Tomas Bata University in Zlin, Czech Republic. Its swelling property (in presence of water, human blood and different pH), antimicrobial property (in presence of skin infection causing agents like: Staphylococcus aureus; bacteria and Candida albicans; fungi) and viscoelastic properties such as storage modulus (G'), loss modulus (G") and complex viscosity (η*) were investigated at room temperature (25-28° C) which demonstrate that PVP-CMC-BA hydrogel is maintaining requisite properties for health care application, specially as a wound dressing material. The elasticity and antimicrobial property of PVP-CMC-BA is directly correlated with percentage of boric acid, an antiseptic agent. The consequential values of viscoelastic properties of the hydrogel (before drying) enable us to understand its specific flexible condition to apply on the surface of human body.

  7. Effect of sporulation medium on wet-heat resistance and structure of Alicyclobacillus acidoterrestris DSM 3922-type strain spores and modeling of the inactivation kinetics in apple juice.

    PubMed

    Molva, Celenk; Baysal, Ayse Handan

    2014-10-17

    Alicyclobacillus acidoterrestris is a spoilage bacterium in fruit juices leading to high economic losses. The present study evaluated the effect of sporulation medium on the thermal inactivation kinetics of A. acidoterrestris DSM 3922 spores in apple juice (pH3.82±0.01; 11.3±0.1 °Brix). Bacillus acidocaldarius agar (BAA), Bacillus acidoterrestris agar (BATA), malt extract agar (MEA), potato dextrose agar (PDA) and B. acidoterrestris broth (BATB) were used for sporulation. Inactivation kinetic parameters at 85, 87.5 and 90°C were obtained using the log-linear model. The decimal reduction times at 85°C (D85°C) were 41.7, 57.6, 76.8, 76.8 and 67.2min; D87.5°C-values were 22.4, 26.7, 32.9, 31.5, and 32.9min; and D90°C-values were 11.6, 9.9, 14.7, 11.9 and 14.1min for spores produced on PDA, MEA, BATA, BAA and BATB, respectively. The estimated z-values were 9.05, 6.60, 6.96, 6.15, and 7.46, respectively. The present study suggests that the sporulation medium affects the wet-heat resistance of A. acidoterrestris DSM 3922 spores. Also, the dipicolinic acid content (DPA) was found highest in heat resistant spores formed on mineral containing media. After wet-heat treatment, loss of internal volume due to the release of DPA from spore core was observed by scanning electron microscopy. Since, there is no standardized media for the sporulation of A. acidoterrestris, the results obtained from this study might be useful to determine and compare the thermal resistance characteristics of A. acidoterrestris spores in fruit juices. PMID:25129530

  8. Effects of pomegranate and pomegranate-apple blend juices on the growth characteristics of Alicyclobacillus acidoterrestris DSM 3922 type strain vegetative cells and spores.

    PubMed

    Molva, Celenk; Baysal, Ayse Handan

    2015-05-01

    The present study examined the growth characteristics of Alicyclobacillus acidoterrestris DSM 3922 vegetative cells and spores after inoculation into apple, pomegranate and pomegranate-apple blend juices (10, 20, 40 and 80%, v/v). Also, the effect of sporulation medium was tested using mineral [Bacillus acidoterrestris agar (BATA) and Bacillus acidocaldarius agar (BAA)] and non-mineral containing media [potato dextrose agar (PDA) and malt extract agar (MEA)]. The juice samples were inoculated separately with approximately 10(5)CFU/mL cells or spores from different sporulation media and then incubated at 37°C for 336 h. The number of cells decreased significantly with increasing pomegranate juice concentration in the blend juices and storage time (p<0.001). Based on the results, 3.17, 3.53, and 3.72 log cell reductions were observed in 40%, 80% blend and pomegranate juices, respectively while the cell counts attained approximately 7.17 log CFU/mL in apple juice after 336 h. On the other hand, the cell growth was inhibited for a certain time, and then the numbers started to increase after 72 and 144 h in 10% and 20% blend juices, respectively. After 336 h, total population among spores produced on PDA, BATA, BAA and MEA indicated 1.49, 1.65, 1.67, and 1.28 log reductions in pomegranate juice; and 1.51, 1.38, 1.40 and 1.16 log reductions in 80% blend juice, respectively. The inhibitory effects of 10%, 20% and 40% blend juices varied depending on the sporulation media used. The results obtained in this study suggested that pomegranate and pomegranate-apple blend juices could inhibit the growth of A. acidoterrestris DSM 3922 vegetative cells and spores. PMID:25676243

  9. Facilitating Professional Development during International Practicum: Understanding Our Work as Teacher Educators through Critical Incidents (Facilitando el desarrollo profesional durante la práctica internacional: Comprendiendo nuestro trabajo como formadores de profesores a través de incidentes críticos)

    ERIC Educational Resources Information Center

    Williams, Judy; Grierson, Arlene

    2016-01-01

    This collaborative self-study details the experiences of an Australian teacher educator and a Canadian teacher educator, who led teacher candidates on international practicum placements to the Cook Islands and Kenya respectively. Focusing on critical incidents, they collaboratively analyzed dilemmas that occurred when providing professional…

  10. Sedimentology and depositional environments of Lower Permian Yeso Formation in northwestern New Mexico

    SciTech Connect

    Stanesco, J.D. )

    1989-09-01

    The northwesternmost exposures of the Lower Permian (Leonardian) Yeso Formation are in uplifts that bound the southern half of the San Juan basin in northwestern New Mexico. The Yeso comprises the Meseta Blanca member and overlying San Ysidro Member. The latter is called the Los Vallos Member in the southern part of the study area. The Meseta Blanca consists of cross-stratified and horizontal to wavy-bedded sandstones of eolian-dune, sand-sheet, and sabkha origin. These facies also occur in the San Ysidro (Los Vallos), which additionally includes mud-draped, ripple-laminated sandstones of supratidal mud-flat origin, gypsiferous sandstones and siltstones of sabkha origin, and evaporite-carbonate rocks of intertidal to marine-shelf origin. Paleocurrent analysis indicates that eolian dunes in the Meseta Blanca migrated southward in the northern part of the study area. These dunes may have been extensions of the DeChelly Sandstone erg to the northwest. Dunes in the southern part of the study area shifted under variable north-south winds. This variability may reflect a seasonal onshore/offshore wind regime. Lateral facies changes in the San Ysidro (Los Vallos) indicate a juxtaposition of eolian-dune and sand-dominated sabkha environments in the northern part of the study area, with coastal-sabkha, tidal, and shelf environments in the southern part. Eolian dunes prograded southward over coastal sabkhas at least 12 times during deposition of the Yeso. A northward shift of all facies during middle San Ysidro deposition suggests a marine transgression from the south.

  11. The Nopal 1 Uranium Deposit: an Overview

    NASA Astrophysics Data System (ADS)

    Calas, G.; Allard, T.; Galoisy, L.

    2007-05-01

    The Nopal 1 natural analogue is located in the Pena Blanca uranium district, about 50 kms north of Chihuahua City, Mexico. The deposit is hosted in tertiary ignimbritic ash-flow tuffs, dated at 44 Ma (Nopal and Colorados formations), and overlying the Pozos conglomerate formation and a sequence of Cretaceous carbonate rocks. The deposit is exposed at the ground surface and consists of a near vertical zone extending over about 100 m with a diameter of 40 m. An interesting characteristic is that the primary mineralization has been exposed above the water table, as a result of the uplift of the Sierra Pena Blanca, and subsequently oxidized with a remobilization of hexavalent uranium. The primary mineralization has been explained by various genetic models. It is associated to an extensive hydrothermal alteration of the volcanic tuffs, locally associated to pyrite and preserved by an intense silicification. Several kaolinite parageneses occur in fissure fillings and feldspar pseudomorphs, within the mineralized breccia pipe and the barren surrounding rhyolitic tuffs. Smectites are mainly developed in the underlying weakly welded tuffs. Several radiation-induced defect centers have been found in these kaolinites providing a unique picture of the dynamics of uranium mobilization (see Allard et al., this session). Another evidence of this mobilization is given by the spectroscopy of uranium-bearing opals, which show characteristic fluorescence spectra of uranyl groups sorbed at the surface of silica. By comparison with the other uranium deposits of the Sierra Pena Blanca and the nearby Sierra de Gomez, the Nopal 1 deposit is original, as it is one of the few deposits hving retained a reduced uranium mineralization.

  12. Learning about the Sky from the Environment: An Experience Working Along One Year with Students of Elementary Education. (Spanish Title: Aprendiendo sobre EL Cielo Desde el Entorno: Una Experiencia Trabajando Durante un Año Junto a Estudiantes del Primario.) Aprendendo sobre o Céu a Partir do Entorno: Uma Experiência de Trabalho ao Longo de um Ano com Alunos de Ensino Fundamental

    NASA Astrophysics Data System (ADS)

    Longhini, Marcos Daniel; Gomide, Hanny Angeles

    2014-12-01

    Research developed with 95 students of the 6th year of elementary education in a public school of Uberlândia, Minas Gerais. It was a continuous work from February to December 2013, which led the students to participate in activities of observation of the environment, specifically the sky, analyzing the changes occurred. We focused on the study of variations in temperature, rainfall, day length, variations in the size of the shadows and changes in the aspect of the Moon. Our focus of analysis targeted the discussion of the knowledge that these students had about the topics indicated and as they entered the stage during the implementation of the proposal. The results showed a limited perception that students have of their environment, however, lately expanded due to the undertaken activities, especially in relation to the Moon. Working with systematic measure procedures reveals the careful handling of data so that they become understandable to students, and working with the shadows points towards the students first understand how shadows are formed, and then apply this knowledge to Astronomy. Finally, we conclude that the lived process consisted of an initial step of a work that should be encouraged for the subsequent years of training of these students. Proyecto de investigación desarrollado con 95 alumnos del sexto año de primaria en una escuela pública de Uberlândia, Minas Gerais. Fue un trabajo continuo, de febrero a diciembre de 2013, que llevó a los estudiantes a participar en actividades de observación de su entorno, entre ellas, el cielo, analizando los cambios ocurridos. Nos centramos en el estudio de las variaciones en la temperatura, las precipitaciones, la duración del día, las variaciones en el tamaño de las sombras y los cambios en los aspectos de la Luna. Nuestro foco de análisis se centró en discutir el conocimiento que estos estudiantes tenían sobre los temas indicados al inicio y término de la propuesta. Los resultados mostraron una percepción limitada que los estudiantes tienen de su alrededor la cual, sin embargo, se expandió debido a las actividades llevadas a cabo, sobre todo en relación con la Luna. Trabajar con medidas sistemáticas revela el manejo cuidadoso de los datos para que sean comprensibles para los estudiantes, así como el trabajo con las sombras para que comprendan primero como se forman estas para después trabajarlas en Astronomía. Por último, llegamos a la conclusión de que el proceso desarrollado consistió en una etapa inicial de una obra que debe ser profundizado en los años posteriores de la formación de estos estudiantes. Projeto de pesquisa desenvolvido com 95 alunos do 6º ano do Ensino Fundamental de uma escola pública estadual de Uberlândia, Minas Gerais. Foi um trabalho contínuo, de fevereiro a dezembro de 2013, o qual levou os alunos a participarem de atividades de observação do entorno, dentre ele, o céu, analisando as mudanças ocorridas. Focamos no estudo das variações de temperaturas, chuvas, duração do dia, variações do tamanho das sombras e mudanças nos aspectos da Lua. Nosso foco de análise centrou-se em discutir os conhecimentos que os referidos alunos tinham acerca dos temas indicados no início e ao término da implementação da proposta. Os resultados mostraram a percepção limitada que os estudantes possuem de seu entorno, todavia, ampliada em função das atividades desenvolvidas, principalmente no que se refere à Lua. O trabalho com medidas sistemáticas revela o cuidado no tratamento dos dados para que eles se tornem compreensíveis aos alunos, assim como o trabalho com as sombras sinaliza para que os alunos primeiramente compreendam como as sombras são formadas para depois trabalhar isso em Astronomia. Por fim, concluímos que o processo vivido constituiu-se em uma etapa inicial de um trabalho que deve ser estimulado para os anos subsequentes da formação desses alunos.

  13. Public Outreach of the South Texas Health Physic Society and Texas A&M University Nuclear Engineering Department

    SciTech Connect

    Berry, R. O.

    2003-02-24

    In a cooperative effort of the members of the South Texas Chapter of the Heath Physics Society (STC-HPS) and the Texas A&M University Nuclear Engineering Department, great efforts have been made to reach out and provide educational opportunities to members of the general public, school age children, and specifically teachers. These efforts have taken the form of Science Teacher Workshops (STW), visits to schools all over the state of Texas, public forums, and many other educational arenas. A major motivational factor for these most recent efforts can be directly tied to the attempt of the State of Texas to site a low-level radioactive waste facility near Sierra Blanca in West Texas. When the State of Texas first proposed to site a low level radioactive waste site after the Low-Level Radioactive Waste Policy Act of 1980 was passed, many years of political struggle ensued. Finally, a site at Sierra Blanca in far West Texas was selected for study and characterization for a disposal site for waste generated in the Texas Compact states of Maine, Vermont and Texas. During this process, the outreach to and education of the local public became a paramount issue.

  14. Suckling kid breed and slaughter weight discrimination using muscle colour and visible reflectance.

    PubMed

    Ripoll, G; Alcalde, M J; Horcada, A; Panea, B

    2011-02-01

    Meat colour was evaluated in 141 male suckling kids from five Spanish breeds: Blanca Andaluza (BA), Blanca Celtibérica (BC), Moncaína (MO), Negra Serrana-Castiza (NE) and Pirenaica (PI). Kids were slaughtered at 7.5 and 11.5 kg. pH and colour were measured in the longissimus thoracis et lumborum muscle. pH values did not differ significantly among breeds. Lightness tended to decrease and redness to increase as weight increased. BC and NE at light weight and BC and BA at heavy weight were characterized by greater lightness, chroma and hue. At both weights MO and PI were darker and showed lower values for chroma and hue. BA at light weight and NE at heavy weight were characterized by values that were between those of the former groups for all variables. Discriminant analysis based on colour and pH correctly classified 48.9% of the kids into their breed and slaughter weight. PMID:21041040

  15. An Andean ice-core record of a Middle Holocene mega-drought in North Africa and Asia

    NASA Astrophysics Data System (ADS)

    Davis, Mary E.; Thompson, Lonnie G.

    An ice core from the Nevado Huascarán col in the Cordillera Blanca of northern Peru contains high-resolution time series of dust concentrations and size distributions since the end of the last glacial stage. A large dust peak, dated ˜4500 years ago, is contemporaneous with a widespread and prolonged drought that apparently extended from North Africa to eastern China, evidence of which occurs in historical, archeological and paleoclimatic records. This event may have been associated with several centuries of weak Asian/Indian/African monsoons, possibly linked with a protracted cooling in the North Atlantic. During the second half of the 20th century, high austral-summer dust concentrations in the Huascarán record are significantly correlated with atmospheric conditions, such as sea-level pressure and zonal wind velocities that are consistent with El Niño-Southern Oscillation (ENSO) and positive North Atlantic Oscillation (NAO) indices, and with aridity in North Africa, southwest Asia and the Middle East. Therefore, the dominant submicron fraction of the dust may have been transported by more intense northeasterly trade winds from the African dry regions across the tropical Atlantic during a period of frequent and/or intense ENSO activity. The proposed ENSO conditions that may have been linked with drought in the monsoon region may also have contributed to aridity in tropical South America, including the Cordillera Blanca.

  16. The application of an MPM-MFM method for simulating weapon-target interaction.

    SciTech Connect

    Ma, X.; Zou, Q.; Zhang, D. Z.; VanderHeyden, W. B.; Wathugala, G. W.; Hasselman, T. K.

    2005-01-01

    During the past two decades, Los Alamos National Laboratory (LANL) has developed computational algorithms and software for analysis of multiphase flow suitable for high-speed projectile penetration of metallic and nonmetallic materials, using a material point method (MPM)-multiphase flow method (MFM). Recently, ACTA has teamed with LANL to advance a computational algorithm for simulating complex weapon-target interaction for penetrating and exploding munitions, such as tank rounds and artillery shells, as well as non-exploding kinetic energy penetrators. This paper will outline the mathematical basis for the MPM-MFM method as implemented in LANL's CartaBlanca code. CartaBlanca, written entirely in Java using object-oriented design, is used to solve complex problems involving (a) failure and penetration of solids, (b) heat transfer, (c) phase change, (d) chemical reactions, and (e) multiphase flow. We will present its application to the penetration of a steel target by a tungsten cylinder and compare results with time-resolved experimental data published by Anderson, et. al., Int. J. Impact Engng., Vol. 16, No. 1, pp. 1-18, 1995.

  17. Yeast Infection and Diabetes Mellitus among Pregnant Mother in Malaysia

    PubMed Central

    Sopian, Iylia Liyana; Shahabudin, Sa’adiah; Ahmed, Mowaffaq Adam; Lung, Leslie Than Thian; Sandai, Doblin

    2016-01-01

    Background Vaginal yeast infection refers to irritation of the vagina due to the presence of opportunistic yeast of the genus Candida (mostly Candida albicans). About 75% of women will have at least one episode of vaginal yeast infection during their lifetime. Several studies have shown that pregnancy and uncontrolled diabetes increase the infection risk. Reproductive hormone fluctuations during pregnancy and elevated glucose levels characteristic of diabetes provide the carbon needed for Candida overgrowth and infection. The goal of this study was to determine the prevalence of vaginal yeast infection among pregnant women with and without diabetes. Methods This was a case-control study using cases reports from Kepala Batas Health Clinic, Penang State, Malaysia from 2006 to 2012. In total, 740 pregnant ladies were chosen as sample of which 370 were diabetic and 370 were non-diabetic cases. Results No relationship between diabetes and the occurrence of vaginal yeast infection in pregnant women was detected, and there was no significant association between infection and age group, race or education level. Conclusion In conclusion, within radius of this study, vaginal yeast infection can occur randomly in pregnant women. PMID:27540323

  18. Occurrence of Trichodinid Ciliophorans (Ciliophora: Peritrichida) in the freshwater fishes of the river Churni with description of Trichodina glossogobae sp. nov. in West Bengal, India.

    PubMed

    Mitra, Amlan Kumar; Bandyopadhyay, Probir K; Gong, Yingchun; Bhowmik, Biplab

    2012-04-01

    Between January 2011 and March 2011 occurrence of trichodinid ciliophorans were studied in the freshwater fishes of the river Churni. The biodiversity survey revealed presence of a new species of the genus Trichodina (Ehrenberg 1830) infesting Glossogobius giuris (Hamilton-Buchanan). Another freshwater fish Labeo bata (Hamilton 1822) were found to be infested with two species of the genus Tripartiella Lom 1959: Tripartiella bulbosa (Davis 1947) Lom 1959 and T. copiosa Lom 1959. Adhesive disc size of the new Trichodina species is small measuring 30.6-46.9 (36.2 ± 3.9) μm in diameter. The centre of the disc is finely granular and transforms into dark when impregnated with silver. The overall prevalence of this species is 15.6% (12/77). Tripartiella bulbosa and T. copiosa are very small sized ciliophorans, measuring 16.7-23.8 (20.6 ± 2.2) μm and 15.2-22.4 (19.7 ± 1.9) μm in diameter, respectively. PMID:23542238

  19. Effect of repeated targeted mass treatment with praziquantel on the prevalence, intensity of infection and morbidity due to Schistosoma intercalatum in an urban community in equatorial Guinea.

    PubMed

    Simarro, P P; Sima, F O; Mir, M; Ndong, P

    1991-09-01

    A longitudinal community-based study was carried out in order to evaluate the impact of repeated selective population chemotherapy with praziquantel on the epidemiology of an urban focus of Schistosoma intercalatum in the city of Bata, capital of the Continental Region of Equatorial Guinea. Three surveys were undertaken in January of 1988, 1989 and 1990, determining parasitological prevalence, intensity of infection and morbidity and applying repeated targeted mass treatment. One dose of praziquantel (40 mg/kg body weight) was given one week after treatment with mebendazole (100 mg every 12 hours for 3 days). A reduction of the overall prevalence by S. intercalatum of 69.9% and 79.3% in the first and second year respectively was found. Persons showing high parasite burden suffered a reduction of 95.7%. The cure rate (no more eggs in stool) was between 90% and 98.9%. A significant decrease of signs and symptoms was observed. No important side effects were detected. This study shows the positive action of praziquantel in reducing prevalence, intensity of infection and morbidity due to S. intercalatum, above all in the case of a high human population participation response. Cure rates obtained being similar to the ones observed using the same drug in Schistosoma mansoni and Schistosoma haematobium. PMID:1801138

  20. African trypanosomiasis and S. intercalatum infection in Equatorial Guinea: comparative epidemiology and feasibility of integrated control.

    PubMed

    Simarro, P P; Sima, F O; Mia, M

    1989-06-01

    The integration of schistosomiasis control with the activities of different endemic disease control or health programmes has been endorsed by a WHO Expert Committee on the Control of Schistosomiasis (WHO 1985). Endemic countries face increasing economic and manpower constraints which limit the coverage and effectiveness of control activities. Integration would be expected to optimize available resources for control. The feasibility of integration can be assessed by a comparative evaluation of: the epidemiology and distribution of the health problems; the techniques and methodology of control; and the requirements for maintenance and their relative health importance. This report presents a preliminary assessment of trypanosomiasis and schistosomiasis in Equatorial Guinea. The background and implementation of the operational national trypanosomiasis control programme are summarized. Population-based epidemiological investigations undertaken by the staff of the trypanosomiasis control programme are reported from a rural village and an urban suburb of Bata, Equatorial Guinea. The distribution and morbidity of S. intercalatum are compared, the public health importance of S. intercalatum is reviewed and the feasibility of integration of control of trypanosomiasis and schistosomiasis are assessed. PMID:2772519

  1. Asians seek end to girls' trafficking.

    PubMed

    1997-01-01

    Each year, approximately 1 million Asian children under 18 years old, many of them female, become prostitutes. With regard to this problem, the Summit Foundation, the United Nations Population Fund, UNICEF, and the Centre for Development and Population Activities are sponsoring a conference entitled "Girls' Rights, Society's Responsibility: Taking Action Against Child Sexual Exploitation," on December 8-10, 1997, at the Nehru Centre, Worli, Bombay. Policy makers from government, the legal and police professions, corporations, the tourism industry, and grassroots organizations will attend. Representatives from Bangladesh, Bhutan, China, India, Maldives, Myanmar, Nepal, Pakistan, the Philippines, Sri Lanka, and Thailand will develop coordinated strategies to end the abuse. The experiences of community-based nongovernmental organizations will be used to develop approaches to prevent exploitation, provide surveillance, and rehabilitate girls who have been exploited. The Nehru Centre, Jet Airways, and the President Hotel of Bombay will provide support. Participants are to include the Ford Foundation, the John D. and Catherine T. MacArthur Foundation, UNIFEM, the World Health Organization, the World Bank, the US Agency for International Development (USAID), Oxfam, CIDA, SIDA, NORAD, and many corporations (Bata, Apeejay, Pepsi, Tata, Godrej, Mahindra and Mahindra, and hotel and tourist businesses). PMID:12292789

  2. Out on the Playing Field: Providing Quality Physical Education and Recreational Opportunities for Lesbian, Gay, and Bisexual Youth

    ERIC Educational Resources Information Center

    White, Christopher S.; Oswalt, Sara B.; Wyatt, Tammy J.; Peterson, Fred L.

    2010-01-01

    Lesbian, gay, and bisexual (LGB) youth may be at a higher risk for depression, suicide, and negative risk-taking (Bontempo & D'Augelli, 2002; DuRant, Krowchuk, & Senal, 1998; Garofalo, Wolf, Kessel, Palfrey, & DuRant, 1998; Hershberger & D'Augelli, 1995; Moon et al., 2000; Rosario, Hunter, & Gwadz, 1997; Rotherum-Borus, Rosario, Van Rossem, Reid,…

  3. Preliminary Geologic Map of the North-Central Part of the Alamosa 30' x 60' Quadrangle, Alamosa, Conejos and Costilla Counties, Colorado

    USGS Publications Warehouse

    Machette, Michael N.; Thompson, Ren A.; Brandt, Theodore R.

    2008-01-01

    This geologic map presents new polygon (geologic map unit contacts) and line (terrace and lacustrine spit/barrier bar) vector data for a map comprised of four 7.5' quadrangles in the north-central part of the Alamosa, Colorado, 30' x 60' quadrangle. The quadrangles include Baldy, Blanca, Blanca SE, and Lasauses. The map database, compiled at 1:50,000 scale from new 1:24,000-scale mapping, provides geologic coverage of an area of current hydrogeologic, tectonic, and stratigraphic interest. The mapped area is located primarily in Costilla County, but contains portions of Alamosa and Conejos Counties, and includes the town of Blanca in its northeastern part. The map area is mainly underlain by surficial geologic materials (fluvial and lacustrine deposits, and eolian sand), but Tertiary volcanic and volcaniclastic rocks crop out in the San Luis Hills, which are in the central and southern parts of the mapped area. The surficial geology of this area has never been mapped at any scale greater than 1:250,000 (broad reconnaissance), so this new map provides important data for ground-water assessments, engineering geology, and the Quaternary geologic history of the San Luis Basin. Newly discovered shoreline deposits are of particular interest (sands and gravels) that are associated with the high-water stand of Lake Alamosa, a Pliocene to middle Pleistocene lake that occupied the San Luis basin prior to its overflow and cutting of a river gorge through the San Luis Hills. After the lake drained, the Rio Grande system included Colorado drainages for the first time since the Miocene (>5.3 Ma). In addition, Servilleta Basalt, which forms the Basaltic Hills on the east margin of the map area, is dated at 3.79+or-0.17 Ma, consistent with its general age range of 3.67-4.84 Ma. This map provides new geologic information for better understanding ground-water flow paths in and adjacent to the Rio Grande system. The map abuts U.S. Geological Survey Open File Report 2005-1392 (a map of

  4. Characterization of Two Microbial Isolates from Andean Lakes in Bolivia

    NASA Technical Reports Server (NTRS)

    Demergasso, C.; Blamey, J.; Escudero, L.; Chong, G.; Casamayor, E. O.; Cabrol, N. A.; Grin, E. A.; Hock, A.; Kiss, A.; Borics, G.

    2004-01-01

    We are currently investigating the biological population present in the highest and least explored perennial lakes on earth in the Bolivian and Chilean Andes, including several volcanic crater lakes of more than 6000 m elevation, in combination of microbiological and molecular biological methods. Our samples were collected in saline lakes of the Laguna Blanca Laguna Verde area in the Bolivian Altiplano and in the Licancabur volcano crater (27 deg. 47 min S/67 deg. 47 min. W) in the ongoing project studying high altitude lakes. The main goal of the project is to look for analogies with Martian paleolakes. These Bolivian lakes can be described as Andean lakes following the classification of Chong. We have attempted to isolate pure cultures and phylogenetically characterize prokaryotes that grew under laboratory conditions. Sediment samples taken from the Licancabur crater lake (LC), Laguna Verde (LV), and Laguna Blanca (LB) were analyzed and cultured using enriched liquid media under both aerobic and anaerobic conditions. All cultures were incubated at room temperature (15 to 20 C) and under light exposure. For the reported isolates, 36 hours incubation were necessary for reaching optimal optical densities to consider them viable cultures. Ten serial dilutions starting from 1% inoculum were required to obtain a suitable enriched cell culture to transfer into solid media. Cultures on solid medium were necessary to verify the formation of colonies in order to isolate pure cultures. Different solid media were prepared using several combinations of both trace minerals and carbohydrates sources in order to fit their nutrient requirements. The microorganisms formed individual colonies on solid media enriched with tryptone, yeast extract and sodium chloride. Cells morphology was studied by optical and electronic microscopy. Rodshape morphologies were observed in most cases. Total bacterial genomic DNA was isolated from 50 ml late-exponential phase culture by using the CTAB

  5. Biostratigraphic implications of the first Eocene land-mammal fauna from the North American coastal plain

    NASA Astrophysics Data System (ADS)

    Westgate, James W.

    1988-11-01

    A newly discovered vertebrate fossil assemblage, the Casa Blanca local fauna, comes from the Laredo Formation, Claiborne Group, of Webb County, Texas, and is the first reported Eocene land-mammal fauna from the coastal plain of North America. The mammalian fauna is correlated with the Serendipity and Candelaria local faunas of west Texas, the Uinta C faunas of the Rocky Mountains, the Santiago Formation local fauna of southern California, and the Swift Current Creek local fauna of Saskatchewan. The vertebrate-bearing deposit lies about 32 m above a horizon containing the marine gastropod Turritella cortezi, which ranges from east Texas to northeast Mexico in the lower half of the Cook Mountain and Laredo Formations and is a guide fossil to the Hurricane Lentil in the Cook Mountain Formation. Nannoplankton found in these middle Eocene formations belong to the upper half of Nannoplankton Zone I6 and allow correlation with European beds of late Lutetian to early Bartonian age.

  6. Hydraulic characterization of hydrothermally altered Nopal tuff

    SciTech Connect

    Green, R.T.; Meyer-James, K.A.; Rice, G.

    1995-07-01

    Understanding the mechanics of variably saturated flow in fractured-porous media is of fundamental importance to evaluating the isolation performance of the proposed high-level radioactive waste repository for the Yucca Mountain site. Developing that understanding must be founded on the analysis and interpretation of laboratory and field data. This report presents an analysis of the unsaturated hydraulic properties of tuff cores from the Pena Blanca natural analog site in Mexico. The basic intent of the analysis was to examine possible trends and relationships between the hydraulic properties and the degree of hydrothermal alteration exhibited by the tuff samples. These data were used in flow simulations to evaluate the significance of a particular conceptual (composite) model and of distinct hydraulic properties on the rate and nature of water flow.

  7. Comparing peasants' perceptions of precipitation change with precipitation records in the tropical Callejón de Huaylas, Peru

    NASA Astrophysics Data System (ADS)

    Gurgiser, W.; Juen, I.; Singer, K.; Neuburger, M.; Schauwecker, S.; Hofer, M.; Kaser, G.

    2015-10-01

    Pronounced hygric seasonality determines the regional climate and, thus, the characteristics of rain-fed agriculture in the Peruvian Callejón de Huaylas (Cordillera Blanca). Peasants in the Cuenca Auqui on the eastern slopes above the city of Huaraz attribute recently experienced challenges in agricultural production mainly to perceived changes in precipitation patterns. Statistical analyses of daily precipitation records at nearby Recuay (1964 to 2013) and Huaraz (1996 to 2013) stations do not corroborate the perceived changes. Either insufficient temporal resolution of available precipitation records or other environmental and sociopolitical factors impacting traditional farming methods may be the reason for the lack of concordance between the two information sources investigated in this study.

  8. Evolución estelar en sistemas binarios

    NASA Astrophysics Data System (ADS)

    De Vito, M. A.; Benvenuto, O.

    Definición y clasificación de sistemas binarios; descripción del comportamiento del sistema frente a la variación de su masa; binarias de rayos X; transferencia de masa en sistemas binarios masivos aplicado al posible esclarecimiento del progenitor azul de la supernova SN 1987A; comentario acerca de la evolución de enanas blancas de helio de baja masa y su conexión con los sistemas binarios; reseña del trabajo de Kippenhahn y Weigert sobre el cual está basado el código evolutivo desarrollado en la FCAG por el Dr. Benvenuto y sobre el cual se trabajará para poder incluir la evolución de una estrella con pérdida de masa perteneciente a un sistema binario.

  9. Arsenic in Water Resources of the Southern Pampa Plains, Argentina

    PubMed Central

    Paoloni, Juan D.; Sequeira, Mario E.; Espósito, Martín E.; Fiorentino, Carmen E.; del C. Blanco, María

    2009-01-01

    Confronted with the need for accessible sources of good quality water and in view of the fact that the threat to public health posed by arsenic occurs mainly through the ingestion of contaminated drinking water, the presence and distribution of arsenic was evaluated in the southern Pampa Plains of Bahía Blanca district in Argentina. The findings show variable concentrations of arsenic in a complex distribution pattern. Complementary information is provided on the behavior of the groundwater resource and its salinity in terms of dissolved ions. Groundwater is the most severely affected, 97% of the samples exceeding the guideline value for arsenic in drinking water as recommended by the WHO (Guidelines for Drinking Water Quality, 2004). and showing maximum concentrations of up to 0.30 mg/L. Informing those responsible for preventive medicine and alerting the community at large will facilitate measures to mitigate exposure and ensure the safety of drinking water. PMID:19936127

  10. Biostratigraphic implications of the first Eocene land-mammal fauna from the North American coastal plain

    SciTech Connect

    Westgate, J.W. )

    1988-11-01

    A newly discovered vertebrate fossil assemblage, the Casa Blanca local fauna, comes from the Laredo Formation, Claiborne Group, of Webb County, Texas, and is the first reported Eocene land-mammal fauna from the coastal plain of North America. The mammalian fauna is correlated with the Serendipity and Canderlaria local faunas of west Texas, the Uinta C faunas of the Rocky Mountains, the Santiago Formation local fauna of southern California, and the Swift Current Creek local fauna of Saskatchewan, The vertebrate-bearing deposit lies about 32 m above a horizon containing the marine gastropod Turritella cortezi, which ranges from east Texas to northeast Mexico in the lower half of the Cook Mountain and Laredo Formations and is a guide fossil to the Hurricane Lentil in the Cook Mountain Formation. Nannoplankton found in these middle Eocene formations belong to the upper half of Nannoplankton Zone 16 and allow correlation with European beds of late Lutetian to early Bartonian age.

  11. Age and extent of the Ilopango TBJ Tephra inferred from a Holocene chronostratigraphic reference section, Lago De Yojoa, Honduras

    USGS Publications Warehouse

    Mehringer, P.J., Jr.; Sarna-Wojcicki, A. M.; Wollwage, L.K.; Sheets, P.

    2005-01-01

    Eruption of central El Salvador's Ilopango Volcano early in the first millennium A.D. caused death, cultural devastation, and exodus of southern Mesoamericans. It also left a time-stratigraphic marker in western El Salvador and adjacent Guatemala - the Ilopango Tierra Blanca Joven, or TBJ tephra. Mineral suites and major element abundances identify a silicic volcanic ash in cores from Lago de Yojoa, Honduras, as Ilopango TBJ. This extends its reported range more than 150 km to the northeast. Analyses of glass from the TBJ tephra from the Chalchuapa archaeological site, El Salvador, and from Lago de Yojoa, Honduras, establish the first major element reference fingerprint for the TBJ tephra. The Lago de Yojoa cores also hold two previously undated trachyandesitic tephra layers originating from the nearby Lake Yojoa Volcanic Field. One fell shortly before 11,000 14C yr B.P. and the other about 8600 14C yr B.P. ?? 2004 University of Washington. All rights reserved.

  12. Aspects of reproductive ecology of Clusia valerioi Standl. and Clusia peninsulae Hammel (sp. nov.), two Central American species of Clusiaceae with resin flowers.

    PubMed

    Hochwallner, H; Vogel, S; Huber, W; Hammel, B E; Weber, A

    2012-01-01

    Clusia valerioi Standl. and C. peninsulae Hammel, sp. nov. (formally established in the Appendix), two Central American species of Clusiaceae offering resin as a floral reward, were studied in the Piedras Blancas National Park, SW Costa Rica. Basic data on phenology, flower structure, course of anthesis, flower visitors, flower visitation and pollination processes, fruit development and seed dispersal are communicated. Resin collection and pollen release are reported and documented in greater detail. The significance of stingless bees for pollination is confirmed, but honeybees were also observed to visit the flowers and to collect resin. The seeds of C. valerioi, exhibiting a clearly ornithochorous character syndrome, were observed to be eaten and dispersed by four species of the tanager family (Thraupidae) and one species of finch (Fringillidae). Ants were also observed to carry away the seeds. PMID:21972795

  13. Extensive characterisation of bioactive phenolic constituents from globe artichoke (Cynara scolymus L.) by HPLC-DAD-ESI-QTOF-MS.

    PubMed

    Abu-Reidah, Ibrahim M; Arráez-Román, David; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto

    2013-12-01

    The aim of this work was to characterise the phenolic compounds in artichoke (hearts) by using HPLC coupled to DAD-ESI-QTOF-MS, which proved useful in characterising 61 phenolic and other polar compounds. Notably, of the 61 compounds characterised, 34 new phenolic compounds with their isomers have been tentatively characterised in artichoke for the first time, namely: 3 hydroxybenzoic acids, 17 hydroxycinnamic acids, 4 lignans, 7 flavones, 2 flavonols, and 1 phenol derivative. Moreover, a total of 28 isomers of previously described phenolics have also been detected. The data compiled from the qualitative polyphenol characterisation indicate that the artichoke extract analysed (Blanca de Tudela variety) could be regarded as a bioactive functional food and also as a promising source of antioxidant phenolic compounds. PMID:23870957

  14. Holocene Paleoglacier History of Glaciar Dalla Vedova, Cordillera DARWIN, Tierra del Fuego, Chile

    NASA Astrophysics Data System (ADS)

    Reynhout, S.

    2015-12-01

    Southernmost South America is unique in its position immediately north of the present-day Antarctic Convergence, making it ideally suited for the evaluation of Antarctic influences on terrestrial paleoclimate. Here we present a glacial geomorphic interpretation of the paleoglacial history of Glaciar Dalla Vedova in Bahía Blanca, Cordillera Darwin, Chile (53°S). This interpretation is further constrained by radiocarbon dating, cosmogenic dating, dendrochronology, and historical photogrammetry. Preliminary field work suggests that Holocene glacier fluctuations have been constrained to within 3 km of the present glacier boundary, punctuated by rapid recent glacier retreat over the past century. By comparing the observed chronology with the record contained further north in Patagonia, we will evaluate possible mechanisms of regional climate variability over the Holocene across southernmost South America.

  15. Oxidative alteration of uraninite at the Nopal I deposit, Mexico: Possible contaminant transport and source term constraints for the proposed repository at Yucca Mountain

    SciTech Connect

    Leslie, B.W.; Pearcy, E.C.; Prikryl, J.D.

    1993-12-31

    The Nopal I uranium deposit at Pena Blanca, Mexico is being studied as a natural analog of the proposed high-level nuclear waste repository at Yucca Mountain. Identification of secondary uranium phases at Nopal I, and the sequence of their formation after uraninite oxidation, provides insight into the source term for uranium, and suggests that uranophane may control uranium release and transport in a silici, tuffaceous, chemically oxidizing, and hydrologically unsaturated environment. Possible constraints on contaminant transport at Nopal I are derived from the spatial distribution of uranium and from measurements of {sup 238}U decay-series isotopes. The analyses indicate that flow of U-bearing fluids was influenced strongly by fracture density, but that the flow of these fluids was not restricted to fractures. Gamma spectroscopic measurements of {sup 238}U decay-series isotopes indicates secular equilibrium, which suggests undetectable U transport under present conditions.

  16. Alisitos Formation calcareous facies - Early Cretaceous episode of tectonic calm

    SciTech Connect

    Suarez-Vidal, F.

    1986-04-01

    The Alisitos Formation (Aptian-Albian), shaped as a marine volcanic arc, crops out along the western side of Baja California bounding the Peninsula Range batholith. Lithologically, this formation is formed by volcanic breccias, porphyritic flows, biohermal limestones, and tuffaceous and pyroclastic sediments. The distribution of the different facies depends on the nature of volcanism and the distance from a volcanic center, although the presence of massive biohermal limestone indicates that in the Early Cretaceous (during tectonic episodes), the volcanic activity decreased to the level that the environmental conditions were favorable for the development of an organic barrier reef behind an island arc. Such conditions pertained south of the Agua Blanca fault and extended to El Arco, Baja California. Based on field observation and petrologic analysis in the Alisitos limestone, an attempt has been made to re-create the environmental condition in the Punta China and San Fernando, Baja California, sites.

  17. Geological Survey investigations in the U12e.05 tunnel, Nevada Test Site

    USGS Publications Warehouse

    Diment, William H.; Wilmarth, V.R.; Houser, F.N.; Dickey, D.D.; Hinrichs, E.N.; Botinelly, T.; Wilcox, R.E.; Byers, F.M., Jr.

    1959-01-01

    The U12e.05 tunnel, one of two laterals from the main U12e tunnel, trends west and connects with the main tunnel about U960 feet from the portal (fig. 2). The U12e.05 tunnel was driven for the nuclear test, code name Blanca, which took place on October 30, 1958. Before the explosion, the tunnel was 8 feet high and 8 to 9 feet wide and consisted of 990 feet of workings, a shot chamber, and an alcove (fig. 2). The original shot chamber, at the west end of the tunnel, was 19 feet long, 10 feet wide, and 15 feet high. The vertical and minimum cover over the original shot chamber are 1,150 and 950 feet, respectively. After detonation of the nuclear device in the test, code named Logan, in the U12e.02 tunnel on October 15, 1958, the U12e.05 tunnel, locally, was damaged severely.

  18. Closure Report for Corrective Action Unit 574: Neptune, Nevada National Security Site, Nevada

    SciTech Connect

    NSTec Environmental Restoration

    2012-04-30

    Corrective Action Unit (CAU) 574 is identified in the Federal Facility Agreement and Consent Order (FFACO) as 'Neptune' and consists of the following two Corrective Action Sites (CASs), located in Area 12 of the Nevada National Security Site: (1) CAS 12-23-10, U12c.03 Crater (Neptune); and (2) CAS 12-45-01, U12e.05 Crater (Blanca). This Closure Report presents information supporting closure of CAU 574 according to the FFACO (FFACO, 1996 [as amended March 2010]) and the Streamlined Approach for Environmental Restoration Plan for CAU 574 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSA/NSO], 2011). The following activities were performed to support closure of CAU 574: (1) In situ external dose rate measurements were collected using thermoluminescent dosimeters at CAS 12-45-01, U12e.05 Crater (Blanca). (2) Total effective dose rates were determined at both sites by summing the internal and external dose rate components. (3) A use restriction (UR) was implemented at CAS 12-23-10, U12c.03 Crater (Neptune). Areas that exceed the final action level (FAL) of 25 millirems per year (mrem/yr) based on the Occasional Use Area exposure scenario are within the existing use restricted area for CAU 551. The 25-mrem/yr FAL is not exceeded outside the existing CAU 551 UR for any of the exposure scenarios (Industrial Area, Remote Work Area, and Occasional Use Area). Therefore, the existing UR for CAU 551 is sufficient to bound contamination that exceeds the FAL. (4) An administrative UR was implemented at CAS 12-45-01, U12e.05 Crater (Blanca) as a best management practice (BMP). The 25-mrem/yr FAL was not exceeded for the Remote Work Area or Occasional Use Area exposure scenarios; therefore, a UR is not required. However, because the 25-mrem/yr FAL was exceeded for the Industrial Area exposure scenario, an administrative UR was established as a BMP. UR documentation is included as Appendix B. The UR at CAS 12-23-10, U12c.03 Crater (Neptune

  19. NSR&D FY15 Final Report. Modeling Mechanical, Thermal, and Chemical Effects of Impact

    SciTech Connect

    Long, Christopher Curtis; Ma, Xia; Zhang, Duan Zhong

    2015-11-02

    The main goal of this project is to develop a computer model that explains and predicts coupled mechanical, thermal and chemical responses of HE under impact and friction insults. The modeling effort is based on the LANL-developed CartaBlanca code, which is implemented with the dual domain material point (DDMP) method to calculate complex and coupled thermal, chemical and mechanical effects among fluids, solids and the transitions between the states. In FY 15, we have implemented the TEPLA material model for metal and performed preliminary can penetration simulation and begun to link with experiment. Currently, we are working on implementing a shock to detonation transition (SDT) model (SURF) and JWL equation of state.

  20. Effect of slaughter weight and breed on instrumental and sensory meat quality of suckling kids.

    PubMed

    Ripoll, G; Alcalde, M J; Horcada, A; Campo, M M; Sañudo, C; Teixeira, A; Panea, B

    2012-09-01

    The effects of breed and slaughter weight on chemical composition, fatty acid groups, texture, and sensory characteristics of meat of 141 suckling male kids from 5 Spanish breeds were studied. There was a decrease in texture and lightness and hue angle with the increase of the slaughter weight. Fatty acid composition was correlated with the intramuscular fat content. All the breeds except MO had values of n-6/n-3 ratio below 4, which is the healthy limit recommended, and a low atherogenic index as well as a low intramuscular fat content. A multivariate analysis discriminated light kid, which had the most tender and juicy meat, from heavy kid which had more intense kid and milk odours. Blanca Andaluza and Pirenaica had most tender and juicy meat. The effect of slaughter weight on meat traits should be considered separately for each breed to find the most appropriate meat according to consumers preferences. PMID:22546814

  1. Comparing peasants' perceptions of precipitation change with precipitation records in the tropical Callejón de Huaylas, Peru

    NASA Astrophysics Data System (ADS)

    Gurgiser, Wolfgang; Juen, Irmgard; Singer, Katrin; Neuburger, Martina; Schauwecker, Simone; Hofer, Marlis; Kaser, Georg

    2016-05-01

    Pronounced hygric seasonality determines the regional climate and, thus, the characteristics of rain-fed agriculture in the Peruvian Callejón de Huaylas (Cordillera Blanca). Peasants in the Cuenca Auqui on the eastern slopes above the city of Huaraz attribute recently experienced challenges in agricultural production mainly to perceived changes in precipitation patterns. Statistical analyses of daily precipitation records at nearby Recuay (1964 to 2013) and Huaraz (1996 to 2013) stations do not corroborate the perceived changes. Either insufficient temporal resolution of available precipitation records or other environmental and sociopolitical factors impacting traditional farming methods may be the reason for the lack of concordance between the two information sources investigated in this study.

  2. Power spectrum and Fisher-Shannon information plane analysis of tidal records

    NASA Astrophysics Data System (ADS)

    Lovallo, Michele; Pierini, Jorge O.; Telesca, Luciano

    2012-10-01

    The time dynamics of tidal fluctuations measured in three sites in Bahia Blanca Estuary (central Argentina), Ingeniero White, Puerto Belgrano and Torre Mareografica, are analyzed. To investigate the time series of the tidal waves we used two different approaches: the power spectral density (PSD) and the Fisher-Shannon (FS) information plane. The PSD permitted: (i) the identification of diurnal, semi-diurnal and higher frequency cycles in all the three tidal signals, and (ii) the detection of two different dynamical regimes (scaling and white-noise), involving respectively timescales lower and higher than about 2-2.5 days. The FS method, which allows to gain insight into the complex structure of a time series, quantifying its degree of organization and order, was applied to the residual tidal series (after removing the main cycles) and permitted to identify a period of low organization in the tidal signal measured at Puerto Belgrano.

  3. Associational Patterns of Scavenger Beetles to Decomposition Stages.

    PubMed

    Zanetti, Noelia I; Visciarelli, Elena C; Centeno, Nestor D

    2015-07-01

    Beetles associated with carrion play an important role in recycling organic matter in an ecosystem. Four experiments on decomposition, one per season, were conducted in a semirural area in Bahía Blanca, Argentina. Melyridae are reported for the first time of forensic interest. Apart from adults and larvae of Scarabaeidae, thirteen species and two genera of other coleopteran families are new forensic records in Argentina. Diversity, abundance, and species composition of beetles showed differences between stages and seasons. Our results differed from other studies conducted in temperate regions. Four guilds and succession patterns were established in relation to decomposition stages and seasons. Dermestidae (necrophages) predominated in winter during the decomposition process; Staphylinidae (necrophiles) in Fresh and Bloat stages during spring, summer, and autumn; and Histeridae (necrophiles) and Cleridae (omnivores) in the following stages during those seasons. Finally, coleopteran activity, diversity and abundance, and decomposition rate change with biogeoclimatic characteristics, which is of significance in forensics. PMID:26174466

  4. Measuring glacier surface temperatures with ground-based thermal infrared imaging

    NASA Astrophysics Data System (ADS)

    Aubry-Wake, Caroline; Baraer, Michel; McKenzie, Jeffrey M.; Mark, Bryan G.; Wigmore, Oliver; Hellström, Robert È.; Lautz, Laura; Somers, Lauren

    2015-10-01

    Spatially distributed surface temperature is an important, yet difficult to observe, variable for physical glacier melt models. We utilize ground-based thermal infrared imagery to obtain spatially distributed surface temperature data for alpine glaciers. The infrared images are used to investigate thermal microscale processes at the glacier surface, such as the effect of surface cover type and the temperature gradient at the glacier margins on the glacier's temperature dynamics. Infrared images were collected at Cuchillacocha Glacier, Cordillera Blanca, Peru, on 23-25 June 2014. The infrared images were corrected based on ground truth points and local meteorological data. For the control points, the Pearson's correlation coefficient between infrared and station temperatures was 0.95. The ground-based infrared camera has the potential for greatly improving glacier energy budget studies, and our research shows that it is critical to properly correct the thermal images to produce robust, quantifiable data.

  5. Radio Brightness Temperatures and Angular Dimensions of Recently Predicted Vl-Bi Small-Scale Structures

    NASA Astrophysics Data System (ADS)

    Opher, R.

    1990-11-01

    RESUMEN. Muestro que analisis recientes publicados de fuentes de radio galacticas y extragalacticas predicen estructuras en pequera escala en fuentes de radio extendidas, remanentes de supernova, vientos protoestelares, nubes moleculares, distorsiones del fondo de 3 K, enanas blancas magnetizadas, estrellas de tipo tardio y el Sol. Discuto las temperatu- ras de brillo de radio de estas estructuras y sus ditnensiones. Muestro que estas estructuras son detectables con las sensibilidades actuales de VLBI (o en el futuro cercano). ABSTRACT. I show that recently published analysis of galactic and extragalactic radio sources make predictions of small-scale structures in extended radio sources, supernovae remnants, protostellar winds, molecu- lar clouds, distortions of the 3 K background, magnetized white dwarf binaries, late-type stars and the sun. I discuss the radio brightness temperatures of these structures and their dimensions. I show that these structures are detectable with present (or near future) VLBI sensitivities. : RADIO SOURCES-EXTENDED

  6. Late Quaternary in a South Atlantic estuarine system: Stratigraphic and paleontologic indicators of coastal evolution

    NASA Astrophysics Data System (ADS)

    Aliotta, Salvador; Ginsberg, Silvia S.; Spagnuolo, Jorge O.; Farinati, Ester; Giagante, Darío; Vecchi, Laura G.

    2013-08-01

    The decisive influence of Late Quaternary sea level changes on the geological evolution of the coastal plain and adjacent continental shelf around the world has long been recognized. Coastal environments evolve actively during transgressive-regressive cycles whose development depends on sea level and sediment supply variations. The interaction of these variables was key to the current morphological and sedimentological configuration of coastal regions. Particularly, the estuarine system of Bahía Blanca (Argentina) presents various types of deposits and marine fossil accumulations, such as paleochannels in the subbottom, sand-shell ridges and extensive layers with fossils in life position. These features are important geological indicators, because its analysis allows us to define different paleoenvironmental conditions that prevailed during the coastal evolutionary process.

  7. Mapping hazards from glacier lake outburst floods based on modelling of process cascades at Lake 513, Carhuaz, Peru

    NASA Astrophysics Data System (ADS)

    Schneider, D.; Huggel, C.; Cochachin, A.; Guillén, S.; García, J.

    2014-01-01

    Recent warming has had enormous impacts on glaciers and high-mountain environments. Hazards have changed or new ones have emerged, including those from glacier lakes that form as glaciers retreat. The Andes of Peru have repeatedly been severely impacted by glacier lake outburst floods in the past. An important recent event occurred in the Cordillera Blanca in 2010 when an ice avalanche impacted a glacier lake and triggered an outburst flood that affected the downstream communities and city of Carhuaz. In this study we evaluate how such complex cascades of mass movement processes can be simulated coupling different physically-based numerical models. We furthermore develop an approach that allows us to elaborate corresponding hazard maps according to existing guidelines for debris flows and based on modelling results and field work.

  8. Alisitos Formation, calcareous facies: Early Cretaceous episode of tectonic calm

    SciTech Connect

    Suarez-Vidal, F.

    1986-07-01

    The Alisitos Formation (Aptian-Albian), shaped as a marine volcanic arc, crops out along the western side of the peninsula of Baja California bounding the Peninsular Range batholith. Lithologically, this formation is formed by volcanic-breccias, porphyritic flows, biohermal limestones, and tuffaceous and pyroclastic sediments. The distribution of the different facies depends on the nature of volcanism and the distance from a volcanic center, although the presence of massive biohermal limestone indicates that in the Early Cretaceous (during the tectonic episodes), the volcanic activity decreased to the level that the environmental conditions were favorable for the development of an organic reef barrier, behind an island arc. Such conditions existed south of the Agua Blanca fault and extended to El Arco, Baja California. Based upon field observations and petrological analysis of the Alisitos limestone, an attempt is made to recreate the environmental condition in the Punta China and San Fernando, Baja California, sites.

  9. Sewage pollution effects on mesozooplankton structure in a shallow temperate estuary.

    PubMed

    Biancalana, Florencia; Menéndez, María C; Berasategui, Anabela A; Fernández-Severini, Melisa D; Hoffmeyer, Mónica S

    2012-06-01

    The effects of a sewage effluent with no treatment on the mesozooplankton structure and the environmental quality were evaluated in the Bahía Blanca Estuary, during June to November 1995. The highest values of particulate organic matter, nutrients and specially phosphate, were observed in the effluent discharge zone. In addition, taxa richness, mesozooplankton abundance and Shannon diversity values were lower in the sewage discharge area compared with the less polluted area. Eurytemora americana and Acartia tonsa as well as larvae of Balanus glandula, Neohelice granulata and Spionidae were found in the discharge area with lower densities. These results highlight the importance of sewage effluent effects on mesozooplankton community providing background data to use in other monitoring programmes. PMID:21814721

  10. Downstream effects of hydropower production on aquatic macroinvertebrate assemblages in two rivers in Costa Rica.

    PubMed

    Chaves-Ulloa, Ramsa; Umaña-Villalobos, Gerardo; Springer, Monika

    2014-04-01

    Despite the fact that little is known about the consequences of hydropower production in tropical areas, many large dams (> 15 m high) are currently under construction or consideration in the tropics. We researched the effects of large hydroelectric dams on aquatic macroinvertebrate assemblages in two Costa Rican rivers. We measured physicochemical characteristics and sampled aquatic macroinvertebrates from March 2003 to March 2004 in two dammed rivers, Peñas Blancas and San Lorenzo, as well as in the undammed Chachagua River. Sites above and below the dam had differences in their physicochemical variables, with wide variation and extreme values in variables measured below the dam in the San Lorenzo River. Sites below the dams had reduced water discharges, velocities, and depths when compared with sites above the dams, as well as higher temperatures and conductivity. Sites above dams were dominated by collector-gatherer-scrapers and habitat groups dominated by swimmer-clingers, while sites below dams had a more even representation of groups. In contrast, a comparison between two sites at different elevation in the undammed river maintained a similar assemblage composition. Tributaries might facilitate macroinvertebrate recovery above the turbine house, but the assemblage below the turbine house resembled the one below the dam. A massive sediment release event from the dam decreased the abundance per sample and macroinvertebrate taxa below the dam in the Peñas Blancas River. Our study illustrates the effects of hydropower production on neotropical rivers, highlighting the importance of using multiple measures of macroinvertebrate assemblage structure for assessing this type of environmental impact. PMID:25189078