Sample records for valley colombia analisis

  1. Study of air pollution in the Aburra Valley, Colombia

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bedoya, J.; Bedoya, E.

    1980-01-01

    A study of air pollution in the Aburra Valley, Colombia, showed that in 1978, the total vehicular (automobiles, buses, and trucks) fuel consumption, including gasoline, fuel oil, kerosine and aviation gasoline, was 136 million gal, which, based on EPA emission factors, produced 755 metric tons of particulate matter and 245 metric tons of sulfur dioxide. In the city of Medellin, during 1976-1979, sulfur dioxide concentrations averaged 40 jg/cu m annually at two sampling stations representing the worst cases, a value below the Colombian standard of 70 jg/cu m. The annual average for the city showed an increase of 22 jg/cumore » m in 1977 to 30 jg/cu m in 1979. In March 1978, the Olaya Herrera Airport in Aburra Valley was closed a number of hours due to lack of visibility caused by fumes; on 3/17/78, it was closed ten hours. The economic and demographic aspects of the Aburra Valley, industrial sources of pollution in the Valley and Colombian air pollution regulations are discussed.« less

  2. Reservoir performance of Late Eocene incised valley fills, Cusiana Field, Llanos Foothills, Eastern Colombia

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pulham, A.; Edward, W.; App, J.

    1996-12-31

    The Cusiana Field is located in the Llanos Foothills of Eastern Colombia. The principal reservoir is the late Eocene Mirador Formation which comprises >50% of reserves. Currently the Mirador reservoir is providing nearly all of the 150,00bopd of production from the Cusiana Field. The Mirador reservoir comprises a stack of incised valley deposits. The fills of the valleys are dominated by quartz arenite sandstones. The average porosity of the valley sandstones is 8% which reflects abundant quartz cement ({approximately}14%) and significant compaction during deep burial ({approximately}20,000feet). Single valleys are up to 70 feet thick and exhibit a distinctive bipartite fillmore » that reflects changing energy conditions during filling. Bases of valleys have the coarsest grain size and have sedimentological and trace fossil evidence for deposition in highly stressed, brackish water environments. The upper parts of the valleys are typically finer grained and were deposited in more saline settings. Despite the low porosity of the Mirador valleys, drill stem tests and production log data show that they have phenomenal performance characteristics. Rates of {ge}10,000bopd are achieved from single valleys. Bases of the valley fills are the key contributors to flow. Integration of detailed core and pore system analysis with the reservoir performance data shows that the permeability fabric of the Mirador can be explained by original depositional architecture and simple loss of primary porosity. Comparison of Cusiana with other quartz-rich sandstones from around the world suggests that it`s low porosity/high performance is predictable.« less

  3. Hydrogeological Characterization of the Middle Magdalena Valley - Colombia

    NASA Astrophysics Data System (ADS)

    Arenas, Maria Cristina; Riva, Monica; Donado, Leonardo David; Guadagnini, Alberto

    2017-04-01

    We provide a detailed hydrogeological characterization of the complex aquifer system of the Middle Magdalena Valley, Colombia. The latter is comprised by 3 sub-basins within which 7 blocks have been identified for active exploration and potential production of oil and gas. As such, there is a critical need to establish modern water resources management practices in the area to accommodate the variety of social, environmental and industrial needs. We do so by starting from a detailed hydrogeological characterization of the system and focus on: (a) a detailed hydrogeological reconnaissance of the area leading to the definition of the main hydrogeological units; (b) the collection, organization and analysis of daily climatic data from 39 stations available in the region; and (c) the assessment of the groundwater flow circulation through the formulation of a conceptual and a mathematical model of the subsurface system. Groundwater flow is simulated in the SAM 1.1 aquifer located in the Middle Magdalena Valley with the objective of showing and evaluating alternative conceptual hydrogeological modeling alternatives. We focus here on modeling results at system equilibrium (i.e., under steady-state conditions) and assess the value of available information in the context of the candidate modeling strategies we consider. Results of our modeling effort are conducive to the characterization of the distributed hydrogeological budget and the assessment of critical areas as a function of the conceptualization of the system functioning and data avilability.

  4. Hydrological Modelling the Middle Magdalena Valley (Colombia)

    NASA Astrophysics Data System (ADS)

    Arenas, M. C.; Duque, N.; Arboleda, P.; Guadagnini, A.; Riva, M.; Donado-Garzon, L. D.

    2017-12-01

    Hydrological distributed modeling is key point for a comprehensive assessment of the feedback between the dynamics of the hydrological cycle, climate conditions and land use. Such modeling results are markedly relevant in the fields of water resources management, natural hazards and oil and gas industry. Here, we employ TopModel (TOPography based hydrological MODEL) for the hydrological modeling of an area in the Middle Magdalena Valley (MMV), a tropical basin located in Colombia. This study is located over the intertropical convergence zone and is characterized by special meteorological conditions, with fast water fluxes over the year. It has been subject to significant land use changes, as a result of intense economical activities, i.e., and agriculture, energy and oil & gas production. The model employees a record of 12 years of daily precipitation and evapotranspiration data as inputs. Streamflow data monitored across the same time frame are used for model calibration. The latter is performed by considering data from 2000 to 2008. Model validation then relies on observations from 2009 to 2012. The robustness of our analyses is based on the Nash-Sutcliffe coefficient (values of this metric being 0.62 and 0.53, respectively for model calibration and validation). Our results reveal high water storage capacity in the soil, and a marked subsurface runoff, consistent with the characteristics of the soil types in the regions. A significant influence on runoff response of the basin to topographical factors represented in the model is evidenced. Our calibrated model provides relevant indications about recharge in the region, which is important to quantify the interaction between surface water and groundwater, specially during the dry season, which is more relevant in climate-change and climate-variability scenarios.

  5. Social urbanization in the Cauca Valley, Colombia.

    PubMed

    Whiteford, M B

    1979-01-01

    "This paper treats aspects of the urbanization of the countryside occurring in southern Colombia. It focuses on those urban-emanating forces that provide rural people with a perspective of 'city' life. The impact of such things as the construction (or improvement) of roads, the role of the media, return visits by ex-villagers, and the urban visiting of country people [is] discussed in terms of social urbanization. This presentation renews the call for eschewing bipolar models for studying migration/urbanization in favor of a broader and more holistic perspective. Furthermore, this article suggests that urbanization is another manifestation of a type of dependency relationship." excerpt

  6. Strong Motion Network of Medellín and Aburrá Valley: technical advances, seismicity records and micro-earthquake monitoring

    NASA Astrophysics Data System (ADS)

    Posada, G.; Trujillo, J. C., Sr.; Hoyos, C.; Monsalve, G.

    2017-12-01

    The tectonics setting of Colombia is determined by the interaction of Nazca, Caribbean and South American plates, together with the Panama-Choco block collision, which makes a seismically active region. Regional seismic monitoring is carried out by the National Seismological Network of Colombia and the Accelerometer National Network of Colombia. Both networks calculate locations, magnitudes, depths and accelerations, and other seismic parameters. The Medellín - Aburra Valley is located in the Northern segment of the Central Cordillera of Colombia, and according to the Colombian technical seismic norm (NSR-10), is a region of intermediate hazard, because of the proximity to seismic sources of the Valley. Seismic monitoring in the Aburra Valley began in 1996 with an accelerometer network which consisted of 38 instruments. Currently, the network consists of 26 stations and is run by the Early Warning System of Medellin and Aburra Valley (SIATA). The technical advances have allowed the real-time communication since a year ago, currently with 10 stations; post-earthquake data is processed through operationally near-real-time, obtaining quick results in terms of location, acceleration, spectrum response and Fourier analysis; this information is displayed at the SIATA web site. The strong motion database is composed by 280 earthquakes; this information is the basis for the estimation of seismic hazards and risk for the region. A basic statistical analysis of the main information was carried out, including the total recorded events per station, natural frequency, maximum accelerations, depths and magnitudes, which allowed us to identify the main seismic sources, and some seismic site parameters. With the idea of a more complete seismic monitoring and in order to identify seismic sources beneath the Valley, we are in the process of installing 10 low-cost shake seismometers for micro-earthquake monitoring. There is no historical record of earthquakes with a magnitude

  7. Toxicosis by Plant Alkaloids in Humans and Animals in Colombia

    PubMed Central

    Diaz, Gonzalo J.

    2015-01-01

    Due to its tropical location, chains of mountains, inter-Andean valleys, Amazon basin area, eastern plains and shores on both the Atlantic and Pacific Oceans, Colombia has many ecosystems and the second largest plant biodiversity in the world. Many plant species, both native and naturalized, are currently recognized as toxic for both animals and humans, and some of them are known to cause their toxic effects due to their alkaloid content. Among these, there are plants containing the hepatotoxic pyrrolizidine alkaloids, neurotoxins such as the indolizidine alkaloid swainsonine and the piperidine alkaloids coniine and γ-coniceine and tropane alkaloids. Unfortunately, the research in toxic plants in Colombia is not nearly proportional to its plant biodiversity and the scientific information available is only very scarce. The present review aims at summarizing the scarce information about plant alkaloid toxicosis in animals and humans in Colombia. PMID:26690479

  8. Depositional and provenance record of the Paleogene transition from foreland to hinterland basin evolution during Andean orogenesis, northern Middle Magdalena Valley Basin, Colombia

    NASA Astrophysics Data System (ADS)

    Moreno, Christopher J.; Horton, Brian K.; Caballero, Victor; Mora, Andrés; Parra, Mauricio; Sierra, Jair

    2011-10-01

    The Central Cordillera and Eastern Cordillera of the northern Andes form the topographic flanks of the north-trending Magdalena Valley Basin. Constraining the growth of these ranges and intervening basin has implications for Andean shortening and the transformation from a foreland to hinterland basin configuration. We present sedimentological, paleocurrent, and sandstone petrographic results from Cenozoic type localities to provide insights into the tectonic history of the northern Middle Magdalena Valley Basin of Colombia. In the Nuevo Mundo Syncline, the mid-Paleocene transition from marine to nonmarine deposystems of the Lisama Formation corresponds with a paleocurrent shift from northward to eastward transport. These changes match detrital geochronological evidence for a contemporaneous shift from cratonic (Amazonian) to orogenic (Andean) provenance, suggesting initial shortening-related uplift of the Central Cordillera and foreland basin generation in the Magdalena Valley by mid-Paleocene time. Subsequent establishment of a meandering fluvial system is recorded in lower-middle Eocene strata of the lower La Paz Formation. Eastward paleocurrents in mid-Paleocene through uppermost Eocene fluvial deposits indicate a continuous influence of western sediment source areas. However, at the upper middle Eocene (˜40 Ma) boundary between the lower and upper La Paz Formation, sandstone compositions show a drastic decrease in lithic content, particularly lithic volcanic fragments. This change is accompanied by a facies shift from mixed channel and overbank facies to thick, amalgamated braided fluvial deposits of possible fluvial megafans, reflecting changes in both the composition and proximity of western sediment sources. We attribute these modifications to the growing influence of exhumed La Cira-Infantas paleohighs in the axial Magdalena Valley, features presently buried beneath upper Eocene-Quaternary basin fill along the western flank of the Nuevo Mundo Syncline. In

  9. [Distribution of Leishmania infantum vector species in Colombia].

    PubMed

    González, Camila; Cabrera, Olga L; Munstermann, Leonard E; Ferro, Cristina

    2006-10-01

    Since entomological surveillance is the main control strategy for visceral leishmaniasis, updated information on the distribution and ecology of involved vector species is necessary for planning preventive measures. To present the updated and geo-referenced distribution of L. longipalpis and L. evansi, vectors of visceral leishmaniasis in Colombia, considering their relationship with their habitat. Distribution was estimated from records of the sand fly specimens collected since 1967. The information was organized in a database from which the localities were selected and geographically analyzed with Arc view in order to develop the distribution maps. 40 localities were established for L. longipalpis along the upper (24), middle (11) and lower (5) Magdalena river valley. L. evansi was recorded in 19 localities of the middle (5) and lower (14) Magdalena valley. Both species showed consistent association with dry tropical forest (sensu Holdridge 1967), confirming the epidemiological risk for visceral leishmaniasis in these areas.

  10. Relationship between VOC and NOx emissions and chemical production of tropospheric ozone in the Aburrá Valley (Colombia).

    PubMed

    Toro, María Victoria; Cremades, Lázaro V; Calbó, Josep

    2006-10-01

    Relationship between volatile organic compounds (VOC) and nitrogen oxides (NOx) emissions and the chemical production of tropospheric ozone is studied through mathematical simulation. The study is applied to the Aburrá Valley, in the Colombian Andes, which is a practically unknown area from the point of view of ozone formation. The model used for this application is the European modelling of atmospheric constituents (EUMAC) zooming model (EZM) which consists of a mesoscale prognostic model (MEMO, mesoscale meteorological model) and a chemical reaction model (MUSE, multiscale for the atmospheric dispersion of reactive species), coupled to the chemical mechanism EMEP (European monitoring and evaluation program). The analysis is performed for a real episode that was characterized by high ozone production and that happened during the 23rd and 24th December, 1999 in Medellín (Colombia). From this real scenario, a sensitivity analysis has been carried out in order to assess the influence of VOC and NOx amounts on ozone production and to extract some conclusions for future ozone abatement policies in Andean regions. As far as ozone air quality is concerned, it is shown that in order to keep current levels the emphasis must be put to avoid increasing NOx emissions, or alternatively, to augment VOC emissions in order to have a high VOC/NOx ratio.

  11. Coupled surface and subsurface flow modeling of natural hillslopes in the Aburrá Valley (Medellín, Colombia)

    NASA Astrophysics Data System (ADS)

    Blessent, Daniela; Barco, Janet; Temgoua, André Guy Tranquille; Echeverrri-Ramirez, Oscar

    2017-03-01

    Numerical results are presented of surface-subsurface water modeling of a natural hillslope located in the Aburrá Valley, in the city of Medellín (Antioquia, Colombia). The integrated finite-element hydrogeological simulator HydroGeoSphere is used to conduct transient variably saturated simulations. The objective is to analyze pore-water pressure and saturation variation at shallow depths, as well as volumes of water infiltrated in the porous medium. These aspects are important in the region of study, which is highly affected by soil movements, especially during the high-rain seasons that occur twice a year. The modeling exercise considers rainfall events that occurred between October and December 2014 and a hillslope that is currently monitored because of soil instability problems. Simulation results show that rainfall temporal variability, mesh resolution, coupling length, and the conceptual model chosen to represent the heterogeneous soil, have a noticeable influence on results, particularly for high rainfall intensities. Results also indicate that surface-subsurface coupled modeling is required to avoid unrealistic increase in hydraulic heads when high rainfall intensities cause top-down saturation of soil. This work is a first effort towards fostering hydrogeological modeling expertise that may support the development of monitoring systems and early landslide warning in a country where the rainy season is often the cause of hydrogeological tragedies associated with landslides, mud flow or debris flow.

  12. Predicted altitudinal shifts and reduced spatial distribution of Leishmania infantum vector species under climate change scenarios in Colombia.

    PubMed

    González, Camila; Paz, Andrea; Ferro, Cristina

    2014-01-01

    Visceral leishmaniasis (VL) is caused by the trypanosomatid parasite Leishmania infantum (=Leishmania chagasi), and is epidemiologically relevant due to its wide geographic distribution, the number of annual cases reported and the increase in its co-infection with HIV. Two vector species have been incriminated in the Americas: Lutzomyia longipalpis and Lutzomyia evansi. In Colombia, L. longipalpis is distributed along the Magdalena River Valley while L. evansi is only found in the northern part of the Country. Regarding the epidemiology of the disease, in Colombia the incidence of VL has decreased over the last few years without any intervention being implemented. Additionally, changes in transmission cycles have been reported with urban transmission occurring in the Caribbean Coast. In Europe and North America climate change seems to be driving a latitudinal shift of leishmaniasis transmission. Here, we explored the spatial distribution of the two known vector species of L. infantum in Colombia and projected its future distribution into climate change scenarios to establish the expansion potential of the disease. An updated database including L. longipalpis and L. evansi collection records from Colombia was compiled. Ecological niche models were performed for each species using the Maxent software and 13 Worldclim bioclimatic coverages. Projections were made for the pessimistic CSIRO A2 scenario, which predicts the higher increase in temperature due to non-emission reduction, and the optimistic Hadley B2 Scenario predicting the minimum increase in temperature. The database contained 23 records for L. evansi and 39 records for L. longipalpis, distributed along the Magdalena River Valley and the Caribbean Coast, where the potential distribution areas of both species were also predicted by Maxent. Climate change projections showed a general overall reduction in the spatial distribution of the two vector species, promoting a shift in altitudinal distribution for L

  13. Catalogue of Diptera of Colombia: an introduction.

    PubMed

    Wolff, Marta; Nihei, Silvio S; Carvalho, Claudio J B De

    2016-06-14

    Colombia has an imposing natural wealth due to its topography has many unique characteristics as a consequence of having Caribbean and Pacific shores, as well as sharing part of the Amazon basin and northern Andes mountains. Thus, many natural and biological features are due to the convergence of three biogeographical regions: Pacific, Andes and Amazonia. The Andean uplift created a complex mosaic of mountains and isolated valleys, including eleven biogeographical provinces (Morrone 2006). The Andes dominate the Colombian topography and cross the country south to north. There are three mountain ranges (Western, Central, and Eastern) with a maximum elevation of 5,775 m, and an average elevation of 2,000 m. The Magdalena and Cauca River valleys separate these ranges, that along with the Putumayo and Caquetá Rivers, the Catatumbo watershed, the Darién, Pique Hill, the Orinoquia Region (with its savannas), the Amazon region (with tropical rainforests), and some lower mountain ranges (Macarena and Chiribiquete), have generated the conditions for very high levels of endemism. This variety of conditions has resulted in an extremely diverse plant and animal biota, and in which 48% of the nation remains unexplored.

  14. Petrotectonic characteristics, geochemistry, and U-Pb geochronology of Jurassic plutons in the Upper Magdalena Valley-Colombia: Implications on the evolution of magmatic arcs in the NW Andes

    NASA Astrophysics Data System (ADS)

    Rodríguez, G.; Arango, M. I.; Zapata, G.; Bermúdez, J. G.

    2018-01-01

    Field, petrographic, and geochemical characterization along with U-Pb zircon geochronology of the Jurassic plutons exposed in the Upper Magdalena Valley (Colombia) allowed recognizing distinct western and eastern suites formed in at least three magmatic pulses. The western plutons crop out between the eastern flank of the Central Cordillera and the Las Minas range, being limited by the Avirama and the Betania-El Agrado faults. The western suite comprises a quartz monzonite - quartz monzodiorite - quartz diorite series and subordinate monzogranites. Chemically, the rocks are high-K calc-alkaline I-type granitoids (some reaching the shoshonitic series) with metaluminous of magnesium affinity. Trace-element tectonic discrimination is consistent with magmatism in a continental arc environment. Most rocks of this suite crystallized between 195 and 186 Ma (Early Jurassic, Pliensbachian), but locally some plutons yielded younger ages between 182 and 179 Ma (Early Jurassic, Toarcian). The eastern suite crops out in the eastern margin of the Upper Magdalena Valley, east of the Betania - El Agrado fault. Plutons of this unit belong to the monzogranite series with rock types ranging between syenogranites and granodiorites. They are high-K calc-alkaline continental granitoids, some metaluminous and some peraluminous, related to I-type granites generated in a volcanic arc. Crystallization of the suite was between 173 and 169 Ma (Middle Jurassic, Aalenian-Bajocian), but locally these rocks contain zircon with earlier inherited ages related to the magmatic pulse of the western suite between 182 and 179 Ma (Early Jurassic, Toarcian). The evolution of the Jurassic plutons in the Upper Magdalena Valley is best explained by onset or increase in subduction erosion of the accretionary prism. This explains the eastward migration of the arc away from the trench. Subduction of prism sediments increased the water flux from the subducting slab, decreasing solidus temperatures, therefore

  15. Integrated exploration workflow in the south Middle Magdalena Valley (Colombia)

    NASA Astrophysics Data System (ADS)

    Moretti, Isabelle; Charry, German Rodriguez; Morales, Marcela Mayorga; Mondragon, Juan Carlos

    2010-03-01

    The HC exploration is presently active in the southern part of the Middle Magdalena Valley but only moderate size discoveries have been made up to date. The majority of these discoveries are at shallow depth in the Tertiary section. The structures located in the Valley are faulted anticlines charged by lateral migration from the Cretaceous source rocks that are assumed to be present and mature eastward below the main thrusts and the Guaduas Syncline. Upper Cretaceous reservoirs have also been positively tested. To reduce the risks linked to the exploration of deeper structures below the western thrusts of the Eastern Cordillera, an integrated study was carried out. It includes the acquisition of new seismic data, the integration of all surface and subsurface data within a 3D-geomodel, a quality control of the structural model by restoration and a modeling of the petroleum system (presence and maturity of the Cretaceous source rocks, potential migration pathways). The various steps of this workflow will be presented as well as the main conclusions in term of source rock, deformation phases and timing of the thrust emplacement versus oil maturation and migration. Our data suggest (or confirm) The good potential of the Umir Fm as a source rock. The early (Paleogene) deformation of the Bituima Trigo fault area. The maturity gap within the Cretaceous source rock between the hangingwall and footwall of the Bituima fault that proves an initial offset of Cretaceous burial in the range of 4.5 km between the Upper Cretaceous series westward and the Lower Cretaceous ones eastward of this fault zone. The post Miocene weak reactivation as dextral strike slip of Cretaceous faults such as the San Juan de Rio Seco fault that corresponds to change in the Cretaceous thickness and therefore in the depth of the thrust decollement.

  16. Modeling high resolution stratigraphy in the Cusiana Field, Eastern Colombia; static builds to dynamic simulation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pulham, A.; MacDonald, D.; Colin, D.

    1996-12-31

    The Cusiana Field (BP, Ecopetrol, Total and Triton) is located in the Llanos Foothills of Eastern Colombia. The Cusiana reservoirs range from late Cretaceous, passive margin deltaic to early Tertiary, early foreland basin estuarine-fluvial. The key reservoir is the late Eocene Mirador Formation which comprises over 50% of reserves. Currently the Mirador reservoir is providing nearly all of the 180,00 bopd of production from the Cusiana Field. The Mirador reservoir comprises a stack of incised valley deposits. The fills of the valleys are sandstone-dominated and comprise the majority of the reservoir quality in the reservoir. Critical to an effective understandingmore » of reservoir behavior has been a detailed reservoir description and reservoir modeling of the incised valley stratigraphy in the Mirador. Models have been constructed using the deterministic information provided by extensive core (3000 feet) coupled with stochastic tools and techniques. Dynamic data, provided by extensive acquisition of production logs during early development drilling, have been integrated within the static-descriptions. Important reservoir characteristics such as degree of valley connectivity, intra-valley heterogeneities and textural controls on permeability have been captured in the modeling process. Upscaling of the high resolution static model has preserved the key sequence stratigraphic facets of the reservoir and also incorporated textural controls on relative permeability. Prediction of pressure transient behavior and fluid movement is working well in the full field simulator, VIP.« less

  17. DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    Trinity Gas Corp. officials signed an agreement on May 20, 1997, with the Cauca Valley Corp. (CVC) allowing Trinity to use CVC data to explore for natural gas in the Cauca Valley of Colombia. CVC, Colombia`s Valle del Cauca water resources and environmental division, is evaluating Colombia`s underground water reserves to protect, control and preserve fresh water aquifers, some of which contain natural gas pockets that cause blowouts in farmers` water wells. Preparations now are underway for drilling Trinity`s first well at the Palmira 1 site on the San Jose Hacienda, the largest privately owned sugar cane plantation in themore » valley. Trinity also entered into an agreement with the Cauca Valley Natural Gas and Electricity Project to furnish natural gas, generated electricity and energy fuel for the industrial district in the region. According to this contract, many valley residents will have electric service for the first time.« less

  18. Characterization of the Atmospheric Boundary Layer Over Aburrá Valley Region (Colombia) Using Remote Sensing and Radiosonde Data

    NASA Astrophysics Data System (ADS)

    Herrera, L.; Hoyos Ortiz, C. D.

    2017-12-01

    The spatio-temporal evolution of the Atmospheric Boundary Layer (ABL) in the Aburrá Valley, a narrow highly complex mountainous terrain located in the Colombian Andes, is studied using different datasets including radiosonde and remote sensors from the meteorological network of the Aburrá Valley Early Warning System. Different techniques are developed in order to estimate Mixed Layer Height (MLH) based on variance of the ceilometer backscattering profiles. The Medellín metropolitan area, home of 4.5 million people, is located on the base and the hills of the valley. The generally large aerosol load within the valley from anthropogenic emissions allows the use of ceilometer retrievals of the MLH, especially under stable atmospheric conditions (late at night and early in the morning). Convective atmospheres, however, favor the aerosol dispersion which in turns increases the uncertainty associated with the estimation of the Convective Boundary Layer using ceilometer retrievals. A multi-sensor technique is also developed based on Richardson Number estimations using a Radar Wind Profiler combined with a Microwave Radiometer. Results of this technique seem to be more accurate thorough the diurnal cycle. ABL retrievals are available from October 2014 to April 2017. The diurnal cycle of the ABL exhibits monomodal behavior, highly influenced by the evolution of the potential temperature profile, and the turbulent fluxes near the surface. On the other hand, the backscattering diurnal cycle presents a bimodal structure, showing that the amount of aerosol particles at the lower troposphere is strongly influenced by anthropogenic emissions, dispersion conditioned by topography and by the ABL dynamics, conditioning the available vertical height for the pollutants to interact and disperse. Nevertheless, the amount, distribution or type of atmospheric aerosols does not appear to have a first order influence on the MLH variations or evolution. Results also show that intra

  19. Characterization of the Atmospheric Boundary Layer Over Aburrá Valley Region (Colombia) Using Remote Sensing and Radiosonde Data

    NASA Astrophysics Data System (ADS)

    Harlow, R. C.; Blockley, E. W.; Brooks, I. M.; Essery, R.; Milton, S.; Renfrew, I.; Vosper, S.

    2016-12-01

    The spatio-temporal evolution of the Atmospheric Boundary Layer (ABL) in the Aburrá Valley, a narrow highly complex mountainous terrain located in the Colombian Andes, is studied using different datasets including radiosonde and remote sensors from the meteorological network of the Aburrá Valley Early Warning System. Different techniques are developed in order to estimate Mixed Layer Height (MLH) based on variance of the ceilometer backscattering profiles. The Medellín metropolitan area, home of 4.5 million people, is located on the base and the hills of the valley. The generally large aerosol load within the valley from anthropogenic emissions allows the use of ceilometer retrievals of the MLH, especially under stable atmospheric conditions (late at night and early in the morning). Convective atmospheres, however, favor the aerosol dispersion which in turns increases the uncertainty associated with the estimation of the Convective Boundary Layer using ceilometer retrievals. A multi-sensor technique is also developed based on Richardson Number estimations using a Radar Wind Profiler combined with a Microwave Radiometer. Results of this technique seem to be more accurate thorough the diurnal cycle. ABL retrievals are available from October 2014 to April 2017. The diurnal cycle of the ABL exhibits monomodal behavior, highly influenced by the evolution of the potential temperature profile, and the turbulent fluxes near the surface. On the other hand, the backscattering diurnal cycle presents a bimodal structure, showing that the amount of aerosol particles at the lower troposphere is strongly influenced by anthropogenic emissions, dispersion conditioned by topography and by the ABL dynamics, conditioning the available vertical height for the pollutants to interact and disperse. Nevertheless, the amount, distribution or type of atmospheric aerosols does not appear to have a first order influence on the MLH variations or evolution. Results also show that intra

  20. A distinctive new subspecies of Scytalopus griseicollis (Aves, Passeriformes, Rhinocryptidae) from the northern Eastern Cordillera of Colombia and Venezuela

    PubMed Central

    Avendaño, Jorge Enrique; Donegan, Thomas M.

    2015-01-01

    Abstract We describe a new subspecies of Pale-bellied Tapaculo Scytalopus griseicollis from the northern Eastern Cordillera of Colombia and Venezuela. This form differs diagnosably in plumage from described subspecies Scytalopus griseicollis griseicollis and Scytalopus griseicollis gilesi and from the latter in tail length. It is also differentiated non-diagnosably in voice from both these populations. Ecological niche modelling analysis suggests that the new subspecies is restricted to the Andean montane forest and páramo north of both the arid Chicamocha valley and the Sierra Nevada del Cocuy. PMID:26085800

  1. Valley-dependent band structure and valley polarization in periodically modulated graphene

    NASA Astrophysics Data System (ADS)

    Lu, Wei-Tao

    2016-08-01

    The valley-dependent energy band and transport property of graphene under a periodic magnetic-strained field are studied, where the time-reversal symmetry is broken and the valley degeneracy is lifted. The considered superlattice is composed of two different barriers, providing more degrees of freedom for engineering the electronic structure. The electrons near the K and K' valleys are dominated by different effective superlattices. It is found that the energy bands for both valleys are symmetric with respect to ky=-(AM+ξ AS) /4 under the symmetric superlattices. More finite-energy Dirac points, more prominent collimation behavior, and new crossing points are found for K' valley. The degenerate miniband near the K valley splits into two subminibands and produces a new band gap under the asymmetric superlattices. The velocity for the K' valley is greatly renormalized compared with the K valley, and so we can achieve a finite velocity for the K valley while the velocity for the K' valley is zero. Especially, the miniband and band gap could be manipulated independently, leading to an increase of the conductance. The characteristics of the band structure are reflected in the transmission spectra. The Dirac points and the crossing points appear as pronounced peaks in transmission. A remarkable valley polarization is obtained which is robust to the disorder and can be controlled by the strain, the period, and the voltage.

  2. DNA Barcoding Survey of Anurans across the Eastern Cordillera of Colombia and the Impact of the Andes on Cryptic Diversity

    PubMed Central

    Guarnizo, Carlos E.; Paz, Andrea; Muñoz-Ortiz, Astrid; Flechas, Sandra V.; Méndez-Narváez, Javier; Crawford, Andrew J.

    2015-01-01

    Colombia hosts the second highest amphibian species diversity on Earth, yet its fauna remains poorly studied, especially using molecular genetic techniques. We present the results of the first wide-scale DNA barcoding survey of anurans of Colombia, focusing on a transect across the Eastern Cordillera. We surveyed 10 sites between the Magdalena Valley to the west and the eastern foothills of the Eastern Cordillera, sequencing portions of the mitochondrial 16S ribosomal RNA and cytochrome oxidase subunit 1 (CO1) genes for 235 individuals from 52 nominal species. We applied two barcode algorithms, Automatic Barcode Gap Discovery and Refined Single Linkage Analysis, to estimate the number of clusters or “unconfirmed candidate species” supported by DNA barcode data. Our survey included ~7% of the anuran species known from Colombia. While barcoding algorithms differed slightly in the number of clusters identified, between three and ten nominal species may be obscuring candidate species (in some cases, more than one cryptic species per nominal species). Our data suggest that the high elevations of the Eastern Cordillera and the low elevations of the Chicamocha canyon acted as geographic barriers in at least seven nominal species, promoting strong genetic divergences between populations associated with the Eastern Cordillera. PMID:26000447

  3. Genetic variability among populations of Lutzomyia (Psathyromyia) shannoni (Dyar 1929) (Diptera: Psychodidae: Phlebotominae) in Colombia.

    PubMed

    Cárdenas, E; Munstermann, L E; Martínez, O; Corredor, D; Ferro, C

    2001-02-01

    Polyacrylamide gel electrophoresis was used to elucidate genetic variation at 13 isozyme loci among forest populations of Lutzomyia shannoni from three widely separated locations in Colombia: Palambí (Nariño Department), Cimitarra (Santander Department) and Chinácota (Norte de Santander Department). These samples were compared with a laboratory colony originating from the Magdalena Valley in Central Colombia. The mean heterozygosity ranged from 16 to 22%, with 2.1 to 2.6 alleles detected per locus. Nei's genetic distances among populations were low, ranging from 0.011 to 0.049. The estimated number of migrants (Nm=3.8) based on Wright's F-Statistic, F ST, indicated low levels of gene flow among Lu. shannoni forest populations. This low level of migration indicates that the spread of stomatitis virus occurs via infected host, not by infected insect. In the colony sample of 79 individuals, the Gpi locus was homozygotic (0.62/0.62) in all females and heterozygotic (0.62/0.72) in all males. Although this phenomenon is probably a consequence of colonization, it indicates that Gpi is linked to a sex determining locus.

  4. Combination of RNAseq and SNP nanofluidic array reveals the center of genetic diversity of cacao pathogen Moniliophthora roreri in the upper Magdalena Valley of Colombia and its clonality.

    PubMed

    Ali, Shahin S; Shao, Jonathan; Strem, Mary D; Phillips-Mora, Wilberth; Zhang, Dapeng; Meinhardt, Lyndel W; Bailey, Bryan A

    2015-01-01

    Moniliophthora roreri is the fungal pathogen that causes frosty pod rot (FPR) disease of Theobroma cacao L., the source of chocolate. FPR occurs in most of the cacao producing countries in the Western Hemisphere, causing yield losses up to 80%. Genetic diversity within the FPR pathogen population may allow the population to adapt to changing environmental conditions and adapt to enhanced resistance in the host plant. The present study developed single nucleotide polymorphism (SNP) markers from RNASeq results for 13 M. roreri isolates and validated the markers for their ability to reveal genetic diversity in an international M. roreri collection. The SNP resources reported herein represent the first study of RNA sequencing (RNASeq)-derived SNP validation in M. roreri and demonstrates the utility of RNASeq as an approach for de novo SNP identification in M. roreri. A total of 88 polymorphic SNPs were used to evaluate the genetic diversity of 172 M. roreri cacao isolates resulting in 37 distinct genotypes (including 14 synonymous groups). Absence of heterozygosity for the 88 SNP markers indicates reproduction in M. roreri is clonal and likely due to a homothallic life style. The upper Magdalena Valley of Colombia showed the highest levels of genetic diversity with 20 distinct genotypes of which 13 were limited to this region, and indicates this region as the possible center of origin for M. roreri.

  5. Combination of RNAseq and SNP nanofluidic array reveals the center of genetic diversity of cacao pathogen Moniliophthora roreri in the upper Magdalena Valley of Colombia and its clonality

    PubMed Central

    Ali, Shahin S.; Shao, Jonathan; Strem, Mary D.; Phillips-Mora, Wilberth; Zhang, Dapeng; Meinhardt, Lyndel W.; Bailey, Bryan A.

    2015-01-01

    Moniliophthora roreri is the fungal pathogen that causes frosty pod rot (FPR) disease of Theobroma cacao L., the source of chocolate. FPR occurs in most of the cacao producing countries in the Western Hemisphere, causing yield losses up to 80%. Genetic diversity within the FPR pathogen population may allow the population to adapt to changing environmental conditions and adapt to enhanced resistance in the host plant. The present study developed single nucleotide polymorphism (SNP) markers from RNASeq results for 13 M. roreri isolates and validated the markers for their ability to reveal genetic diversity in an international M. roreri collection. The SNP resources reported herein represent the first study of RNA sequencing (RNASeq)-derived SNP validation in M. roreri and demonstrates the utility of RNASeq as an approach for de novo SNP identification in M. roreri. A total of 88 polymorphic SNPs were used to evaluate the genetic diversity of 172 M. roreri cacao isolates resulting in 37 distinct genotypes (including 14 synonymous groups). Absence of heterozygosity for the 88 SNP markers indicates reproduction in M. roreri is clonal and likely due to a homothallic life style. The upper Magdalena Valley of Colombia showed the highest levels of genetic diversity with 20 distinct genotypes of which 13 were limited to this region, and indicates this region as the possible center of origin for M. roreri. PMID:26379633

  6. Dental education in Colombia

    PubMed Central

    Jaramillo, Jorge A.; Pulido, Jairo H. Ternera; Núñez, Jaime A. Castro; Bird, William F.; Komabayashi, Takashi

    2014-01-01

    This article describes Colombia's development of formal dentistry, its dental school system, curriculum, and dental licensure, and current issues in oral health care. In 1969, there were only 4 dental schools in Colombia; at this writing there are 21. Five dental schools are public and the other 16 are private. Nearly all classes are conducted in Spanish. Undergraduate pre-dental coursework is not a prerequisite for dental school in Colombia. To obtain licensure, Colombian dental students must complete 5 years of study in dental school, earn a diploma, and work for the government for 1 year. There are approximately 41,400 dentists in Colombia, and the number is increasing quickly. However, the unemployment rate among dentists is very high, even though graduation from dental school is extremely difficult. Although the 1,100:1 ratio of citizens to dentists is considered satisfactory, access to dental care is limited due to the high rate of poverty. PMID:20339245

  7. Internal displacement in Colombia

    PubMed Central

    Shultz, James M; Ceballos, Ángela Milena Gómez; Espinel, Zelde; Oliveros, Sofia Rios; Fonseca, Maria Fernanda; Florez, Luis Jorge Hernandez

    2014-01-01

    This commentary aims to delineate the distinguishing features of conflict-induced internal displacement in the nation of Colombia, South America. Even as Colombia is currently implementing a spectrum of legal, social, economic, and health programs for “victims of armed conflict,” with particular focus on internally displaced persons (IDPs), the dynamics of forced migration on a mass scale within this country are little known beyond national borders.   The authors of this commentary are embarking on a global mental health research program in Bogota, Colombia to define best practices for reaching the displaced population and implementing sustainable, evidence-based screening and intervention for common mental disorders. Presenting the defining characteristics of internal displacement in Colombia provides the context for our work and, more importantly, conveys the compelling and complex nature of this humanitarian crisis. We attempt to demonstrate Colombia’s unique position within the global patterning of internal displacement. PMID:28228997

  8. Receiver Function Study of the Crustal Structure Beneath the Northern Andes (colombia)

    NASA Astrophysics Data System (ADS)

    Poveda, E.; Monsalve, G.; Vargas-Jimenez, C. A.

    2013-05-01

    We have investigated crustal thickness beneath the Northern Andes with the teleseismic receiver function technique. We used teleseismic data recorded by an array of 18 broadband stations deployed by the Colombian Seismological Network, and operated by the Colombian Geological Survey. We used the primary P-to-S conversion and crustal reverberations to estimate crustal thickness and average Vp/Vs ratio; using Wadati diagrams, we also calculated the mean crustal Vp/Vs ratio around stations to further constrain the crustal thickness estimation. In northern Colombia, near the Caribbean coast, the estimated crustal thickness ranges from 25 to 30 km; in the Middle Magdalena Valley, crustal thickness is around 40 km; beneath the northern Central Cordillera, the Moho depth is nearly 40 km; at the Ecuador-Colombia border, beneath the western flank of the Andes, the estimated thickness is about 46 km. Receiver functions at a station at the craton in South East Colombia, near the foothills of the Eastern Cordillera, clearly indicate the presence of the Moho discontinuity at a depth near 36 km. The greatest values of crustal thickness occur beneath a plateau (Altiplano Cundiboyacense) on the Eastern Cordillera, near the location of Bogota, with values around 58 km. Receiver functions in the volcanic areas of the south-western Colombian Andes do not show a systematic signal from the Moho, indicating abrupt changes in Moho geometry. Signals at stations on the Eastern Cordillera near Bogota reveal a highly complex crustal structure, with a combination of sedimentary layers up to 9 km thick, dipping interfaces, low velocity layers, anisotropy and/or lateral heterogeneity that still remain to be evaluated. This complexity obeys to the location of these stations at a region of a highly deformed fold and thrust belt.

  9. Genetic diversity and population structure of Anastrepha striata (Diptera: Tephritidae) in three natural regions of southwestern Colombia using mitochondrial sequences.

    PubMed

    Gallo-Franco, Jenny Johana; Velasco-Cuervo, Sandra Marcela; Aguirre-Ramirez, Elkin; González Obando, Ranulfo; Carrejo, Nancy Soraya; Toro-Perea, Nelson

    2017-02-01

    Anastrepha striata is widely distributed across the Americas and is a pest of economically important crops, especially crops of the Myrtaceae family. Insect population structures can be influenced by the presence of physical barriers or characteristics associated with habitat differences. This study evaluated the effect of the Western Andes on the population structure of A. striata. Individuals were collected from Psidium guajava fruits from three natural regions of southwestern Colombia (Pacific Coast, mountainous region and the inter-Andean valley of the Cauca River). Based on a 1318 bp concatenated of the genes Cytochrome Oxidase subunit I (COI) and NADH dehydrogenase subunit 6 (ND6), 14 haplotypes with few changes among them (between 1 and 3) were found. There was only one dominant haplotype in all three regions. No genetic structure associated with the three eco-geographical regions of the study was found. Moreover, the Western Andes are not an effective barrier for the genetic isolation of the populations from the Pacific Coast compared with the inter-Andean valley populations. This genetic homogeneity could be partially due to anthropogenic intervention, which acts as a dispersal agent of infested fruits. Another hypothesis to explain the lack of structure would be the relatively recent arrival of A. striata to the region, as indicated by an analysis of the demographic history, which reveals a process of population expansion. This study represents the first attempt to understand the population genetics of A. striata in Colombia and could contribute to the integral management of this pest.

  10. 77 FR 33237 - Saline Valley Warm Springs Management Plan/Environmental Impact Statement, Death Valley National...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-05

    ... Valley Warm Springs Management Plan/Environmental Impact Statement, Death Valley National Park, Inyo... an Environmental Impact Statement for the Saline Valley Warm Springs Management Plan, Death Valley... analysis process for the Saline Valley Warm Springs Management Plan for Death Valley [[Page 33238...

  11. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

  12. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

  13. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

  14. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

  15. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

  16. Morphology of large valleys on Hawaii - Evidence for groundwater sapping and comparisons with Martian valleys

    NASA Technical Reports Server (NTRS)

    Kochel, R. Craig; Piper, Jonathan F.

    1986-01-01

    Morphometric data on the runoff and sapping valleys on the slopes of Hawaii and Molokai in Hawaii are analyzed. The analysis reveals a clear distinction between the runoff valleys and sapping valleys. The Hawaiian sapping valleys are characterized by: (1) steep valley walls and flat floors, (2) amphitheater heads, (3) low drainage density, (4) paucity of downstream tributaries, (5) low frequency of up-dip tributaries, and (6) structural and stratigraphic control on valley patterns. The characteristics of the Hawaiian sapping valleys are compared to Martian valleys and experimental systems, and good correlation between the data is detected. Flume experiments were also conducted to study the evolution of sapping valleys in response to variable structure and stratigraphy.

  17. Land Reform and Social Change in Colombia.

    ERIC Educational Resources Information Center

    Hirschman, Albert O.; And Others

    This conference report focuses on three major areas of interest: (1) land reform in Colombia, (2) social change in Popayan, and (3) implications for research in agrarian structure in Colombia. A case study dealing with Colombia's sequence of moves toward land reform over the last 40 years is reviewed. The impact of political factors and social…

  18. Valley Fever (Coccidioidomycosis) Statistics

    MedlinePlus

    ... Valley fever may be under-recognized. 2 , 3 Public health surveillance for Valley fever Valley fever is reportable ... MMWR) . Check with your local, state, or territorial public health department for more information about disease reporting requirements ...

  19. Conservation Genetics of Two Highly Endangered and Poorly Known Species of Zamia (Zamiaceae: Cycadales) in Colombia.

    PubMed

    Aristizábal, Arturo; Tuberquia, Dino J; Sanín, María José

    2018-05-11

    Genetic diversity is key in providing the variation needed to face stochastic change. Increased habitat loss alters population size and dynamics posing serious threats to the conservation of wild species. Colombia has undergone massive deforestation over the last century, but harbors extraordinary high species diversity of genus Zamia (Cycadales); however, most of the species are under threat. In this study, we targeted the largest accessible remaining populations of 2 closely related species growing as endemics in the Magdalena Valley region of Colombia. We successfully transferred the SSR loci used in previous Zamia studies to these species. In total, we amplified 13 microsatellite loci in 3 wild populations, aiming at: 1) assessing genetic diversity and 2) understanding if the structure found between the 3 populations reflected species and population boundaries due to ecological and historical genetic isolation. We found that the actual population size does not reflect population genetic diversity with a small population (Perales) harboring the highest genetic diversity. In addition, all populations are highly structured regardless of species containment, all showing signs of genetic isolation. Given the high degree of ecological threat, and the inherent biological traits of Cycads, we provide information regarding the prioritization of populations for ex situ management.

  20. Valley polarization in bismuth

    NASA Astrophysics Data System (ADS)

    Fauque, Benoit

    2013-03-01

    The electronic structure of certain crystal lattices can contain multiple degenerate valleys for their charge carriers to occupy. The principal challenge in the development of valleytronics is to lift the valley degeneracy of charge carriers in a controlled way. In bulk semi-metallic bismuth, the Fermi surface includes three cigar-shaped electron valleys lying almost perpendicular to the high symmetry axis known as the trigonal axis. The in-plane mass anisotropy of each valley exceeds 200 as a consequence of Dirac dispersion, which drastically reduces the effective mass along two out of the three orientations. According to our recent study of angle-dependent magnetoresistance in bismuth, a flow of Dirac electrons along the trigonal axis is extremely sensitive to the orientation of in-plane magnetic field. Thus, a rotatable magnetic field can be used as a valley valve to tune the contribution of each valley to the total conductivity. As a consequence of a unique combination of high mobility and extreme mass anisotropy in bismuth, the effect is visible even at room temperature in a magnetic field of 1 T. Thus, a modest magnetic field can be used as a valley valve in bismuth. The results of our recent investigation of angle-dependent magnetoresistance in other semi-metals and doped semiconductors suggest that a rotating magnetic field can behave as a valley valve in a multi-valley system with sizeable mass anisotropy.

  1. Internal displacement in Colombia: Fifteen distinguishing features.

    PubMed

    Shultz, James M; Ceballos, Ángela Milena Gómez; Espinel, Zelde; Oliveros, Sofia Rios; Fonseca, Maria Fernanda; Florez, Luis Jorge Hernandez

    2014-01-01

    This commentary aims to delineate the distinguishing features of conflict-induced internal displacement in the nation of Colombia, South America. Even as Colombia is currently implementing a spectrum of legal, social, economic, and health programs for "victims of armed conflict," with particular focus on internally displaced persons (IDPs), the dynamics of forced migration on a mass scale within this country are little known beyond national borders.   The authors of this commentary are embarking on a global mental health research program in Bogota, Colombia to define best practices for reaching the displaced population and implementing sustainable, evidence-based screening and intervention for common mental disorders. Presenting the defining characteristics of internal displacement in Colombia provides the context for our work and, more importantly, conveys the compelling and complex nature of this humanitarian crisis. We attempt to demonstrate Colombia's unique position within the global patterning of internal displacement.

  2. Optical manipulation of valley pseudospin

    DOE PAGES

    Ye, Ziliang; Sun, Dezheng; Heinz, Tony F.

    2016-09-19

    The coherent manipulation of spin and pseudospin underlies existing and emerging quantum technologies, including quantum communication and quantum computation. Valley polarization, associated with the occupancy of degenerate, but quantum mechanically distinct valleys in momentum space, closely resembles spin polarization and has been proposed as a pseudospin carrier for the future quantum electronics. Valley exciton polarization has been created in the transition metal dichalcogenide monolayers using excitation by circularly polarized light and has been detected both optically and electrically. In addition, the existence of coherence in the valley pseudospin has been identified experimentally. The manipulation of such valley coherence has, however,more » remained out of reach. In this paper, we demonstrate all-optical control of the valley coherence by means of the pseudomagnetic field associated with the optical Stark effect. Using below-bandgap circularly polarized light, we rotate the valley exciton pseudospin in monolayer WSe 2 on the femtosecond timescale. Both the direction and speed of the rotation can be manipulated optically by tuning the dynamic phase of excitons in opposite valleys. Finally, this study unveils the possibility of generation, manipulation, and detection of the valley pseudospin by coupling to photons.« less

  3. PLAN COLOMBIA: Some Differing Perspectives

    DTIC Science & Technology

    2001-06-01

    PLAN COLOMBIA Some Differing Perspectives Gabriel Marcella Charles E. Wilhelm Alvaro Valencia Tovar Ricardo Arias Calderón Chris Marquis June 2001...COLOMBIA: Some Differing Perspectives Contract or Grant Number Program Element Number Authors Gabriel Marcella ,Charles E. Wilhelm Alvaro Valencia...release, distribution unlimited Supplementary Notes ISBN 1-58487-057-5 Abstract This monograph, with an introduction by Dr. Gabriel Marcella

  4. Mental health law in Colombia

    PubMed Central

    Chaskel, Roberto; Shultz, James M.; Gaviria, Silvia L.; Taborda, Eliana; Vanegas, Roland; García, Natalia Muñoz; Flórez, Luis Jorge Hernández; Espinel, Zelde

    2015-01-01

    Mental health law in Colombia has evolved over the past 50 years, in concert with worldwide recognition and prioritisation of mental healthcare. Laws and policies have become increasingly sophisticated to accommodate the ongoing transformations throughout Colombia’s healthcare system and improvements in mental health screening, treatment and supportive care. Mental health law and policy development have been informed by epidemiological data on patterns of mental disorders in Colombia. Colombia is distinguished by the fact that its mental health laws and policies have been formulated during a 60-year period of continuous armed conflict. The mental health of Colombian citizens has been affected by population-wide exposure to violence and, accordingly, the mental health laws that have been enacted reflect this feature of the Colombian experience. PMID:29093872

  5. Tectonomorphic evolution of the Eastern Cordillera fold-thrust belt, Colombia: New insights based on apatite and zircon (U-Th)/He thermochronometers

    NASA Astrophysics Data System (ADS)

    Ghorbal, B.; Stockli, D. F.; Mora, A.; Horton, B. K.; Blanco, V.; Sanchez, N.

    2010-12-01

    The Eastern Cordillera (EC) of Colombia marks the eastern boundary of Cenozoic fold-thrust deformation in the northern Andes. It is a classic example of an inversion belt formed in the retro-arc region, in this case superimposed on a Triassic/Jurassic to Cretaceous intracontinental rift system of northern South America. Ongoing thrust reactivation (inversion) in this contractional orogen provides an excellent opportunity to study the patterns of deformation and influence of preexisting anisotropies (Mora et al., 2006). The objective of this detailed (U-Th)/He study is to unravel the tectonic and thermal evolution of the EC from the Magdalena Valley basin in the west to the Llanos foreland basin in the east and reconstruct the temporal and spatial progression of deformation in the EC fold-thrust belt. Furthermore, the Subandean or foothills zone of Colombia is key for understanding the petroleum systems in the complex frontal zone of the inverted fold-thrust belt. We present detailed apatite and zircon (U-Th)/He thermochronometric data from surface samples along a ~220 km WNW-ESE transect across the EC from the frontal fold-thrust belt at the edge of the Llanos basin to the western edge of the EC, the Magdalena basin. Surface and borehole zircon and apatite (U-Th)/He data, integrated with structural data, show that the EC fold-thrust belt propagated foreland-ward from the axial zone to the modern edges of the fold-thrust belt from at least the early Oligocene to the early Miocene. Detailed apatite and zircon (U-Th)/He data from surface samples and borehole samples in the foothills-Llanos transition zone and the Middle Magdalena Valley basin, between the large-displacement Guaicaramo and Pajarito-Chámeza thrusts in the east and the La Salina fault system in the west show a temporally complex evolution. The frontal fold-thrust belt was characterized by continued progressive foreland-ward migration of deformation and an apparent phase of major out-of-sequence motion

  6. Chuckwalla Valley multiple-well monitoring site, Chuckwalla Valley, Riverside County

    USGS Publications Warehouse

    Everett, Rhett

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Bureau of Land Management, is evaluating the geohydrology and water availability of the Chuckwalla Valley, California. As part of this evaluation, the USGS installed the Chuckwalla Valley multiple-well monitoring site (CWV1) in the southeastern portion of the Chuckwalla Basin. Data collected at this site provide information about the geology, hydrology, geophysics, and geochemistry of the local aquifer system, thus enhancing the understanding of the geohydrologic framework of the Chuckwalla Valley. This report presents construction information for the CWV1 multiple-well monitoring site and initial geohydrologic data collected from the site.

  7. Sacramento Valley, CA, USA

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The Sacramento Valley (40.5N, 121.5W) of California is the northern extension of the Central Valley, main agriculture region of the state. Hundreds of truck farms, vineyards and orchards can be seen throughout the length and breadth of the valley which was reclaimed from the desert by means of intensive and extensive irrigation projects.

  8. Effects of realistic topography on the ground motion of the Colombian Andes - A case study at the Aburrá Valley, Antioquia

    NASA Astrophysics Data System (ADS)

    Restrepo, Doriam; Bielak, Jacobo; Serrano, Ricardo; Gómez, Juan; Jaramillo, Juan

    2016-03-01

    This paper presents a set of deterministic 3-D ground motion simulations for the greater metropolitan area of Medellín in the Aburrá Valley, an earthquake-prone region of the Colombian Andes that exhibits moderate-to-strong topographic irregularities. We created the velocity model of the Aburrá Valley region (version 1) using the geological structures as a basis for determining the shear wave velocity. The irregular surficial topography is considered by means of a fictitious domain strategy. The simulations cover a 50 × 50 × 25 km3 volume, and four Mw = 5 rupture scenarios along a segment of the Romeral fault, a significant source of seismic activity in Colombia. In order to examine the sensitivity of ground motion to the irregular topography and the 3-D effects of the valley, each earthquake scenario was simulated with three different models: (i) realistic 3-D velocity structure plus realistic topography, (ii) realistic 3-D velocity structure without topography, and (iii) homogeneous half-space with realistic topography. Our results show how surface topography affects the ground response. In particular, our findings highlight the importance of the combined interaction between source-effects, source-directivity, focusing, soft-soil conditions, and 3-D topography. We provide quantitative evidence of this interaction and show that topographic amplification factors can be as high as 500 per cent at some locations. In other areas within the valley, the topographic effects result in relative reductions, but these lie in the 0-150 per cent range.

  9. Sacramento Valley, CA, USA

    NASA Image and Video Library

    1973-06-22

    SL2-04-179 (22 June 1973) --- The Sacramento Valley (40.5N, 121.5W) of California is the northern extension of the Central Valley, main agriculture region of the state. Hundreds of truck farms, vineyards and orchards can be seen throughout the length and breadth of the valley which was reclaimed from the desert by means of intensive and extensive irrigation projects. Photo credit: NASA

  10. Space Radar Image of Ruiz Volcano, Colombia

    NASA Image and Video Library

    1999-04-15

    This spaceborne radar image shows the Ruiz-Tolima volcanic region in central Colombia, about 150 kilometers 93 miles west of Bogata. The town of Manizales, Colombia, is the pinkish area in the upper right of the image.

  11. Observation of acoustic valley vortex states and valley-chirality locked beam splitting

    NASA Astrophysics Data System (ADS)

    Ye, Liping; Qiu, Chunyin; Lu, Jiuyang; Wen, Xinhua; Shen, Yuanyuan; Ke, Manzhu; Zhang, Fan; Liu, Zhengyou

    2017-05-01

    We report an experimental observation of the classical version of valley polarized states in a two-dimensional hexagonal sonic crystal. The acoustic valley states, which carry specific linear momenta and orbital angular momenta, were selectively excited by external Gaussian beams and conveniently confirmed by the pressure distribution outside the crystal, according to the criterion of momentum conservation. The vortex nature of such intriguing bulk crystal states was directly characterized by scanning the phase profile inside the crystal. In addition, we observed a peculiar beam-splitting phenomenon, in which the separated beams are constructed by different valleys and locked to the opposite vortex chirality. The exceptional sound transport, encoded with valley-chirality locked information, may serve as the basis of designing conceptually interesting acoustic devices with unconventional functions.

  12. Dry Valleys, Antarctica

    NASA Image and Video Library

    2009-11-02

    The McMurdo Dry Valleys are a row of valleys west of McMurdo Sound, Antarctica. They are so named because of their extremely low humidity and lack of snow and ice cover. This image was acquired December 8, 2002 by NASA Terra spacecraft.

  13. The U.S.-Colombia Free Trade Agreement: Economic and Political Implications

    DTIC Science & Technology

    2008-05-01

    a Colombia, Anuncia el Presidente de Colombia en Entrevista a Caracol Radio,” May 3, 2007. 48 Colombia’s Observatorio del Programa Presidencial de ...Presidente de Colombia en Entrevista a Caracol Radio,” May 3, 2007. 51 Embassy of Colombia, pp. 11-12. that under President Uribe’s leadership, Colombia has...American Free Trade Agreement (NAFTA), the U.S.- Chile Free Trade Agreement, the Dominican Republic-Central America Free Trade Agreement (CAFTA-DR

  14. Genetic structure of local populations of Lutzomyia longipalpis (Diptera: Psychodidae) in central Colombia.

    PubMed

    Munstermann, L E; Morrison, A C; Ferro, C; Pardo, R; Torres, M

    1998-01-01

    Lutzomyia longipalpis (Lutz & Neiva), the sand fly vector of American visceral leishmaniasis in the New World tropics, has a broad but discontinuous geographical distribution from southern Mexico to Argentina. A baseline for population genetic structure and genetic variability for this species was obtained by analyzing 5 local, peridomestic populations at the approximate center of its distribution, the Magdalena River Valley of central Colombia. Three populations of L. longipalpis from El Callejón, a small rural community, were compared with 2 populations from neighboring areas 12 and 25 km distant for genetic variation at 15 isoenzyme loci. The mean heterozygosity ranged from 11 to 16%, with 1.2 to 2.3 alleles detected per locus. Nei's genetic distances among the populations were very low, ranging from 0.001 to 0.007. Gene flow estimates based on FST indicated high levels of gene flow among local L. longipalpis populations, with minimal population substructuring.

  15. Ground-water conditions in southern Utah Valley and Goshen Valley, Utah

    USGS Publications Warehouse

    Cordova, R.M.

    1970-01-01

    The investigation of ground-water conditions in southern Utah Valley and Goshen Valley, Utah, was made by the U. S. Geological Survey as part of a cooperative program with the Utah Department of Natural Resources, Division of Water Rights, to investigate the water resources of the State. The purposes of the investigation were to (1) determine the occurrence, recharge, discharge, movement, storage, chemical quality, and availability of ground water; (2) appraise the effects of increased withdrawal of water from wells; and (3) evaluate the effect of the Central Utah Project on the ground-water reservoir and the water supply of Utah Lake.This report presents a description of the aquifer system in the two valleys, a detailed description of the ground-water resources, and conclusions about potential development and its effect on the hydrologic conditions in the valleys. Two supplementary reports are products of the investigation. A basic-data release (Cordova, 1969) contains most of the basic data collected for the investigation, including well characteristics, drillers' logs, water levels, pumpage from wells, chemical analyses of ground and surface waters, and discharge of selected springs, drains, and streams. An interpretive report (Cordova and Mower, 1967) contains the results of a large-scale aquifer test in southern Utah Valley.

  16. Analysis of Mining-induced Valley Closure Movements

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Mitra, R.; Oh, J.; Hebblewhite, B.

    2016-05-01

    Valley closure movements have been observed for decades in Australia and overseas when underground mining occurred beneath or in close proximity to valleys and other forms of irregular topographies. Valley closure is defined as the inward movements of the valley sides towards the valley centreline. Due to the complexity of the local geology and the interplay between several geological, topographical and mining factors, the underlying mechanisms that actually cause this behaviour are not completely understood. A comprehensive programme of numerical modelling investigations has been carried out to further evaluate and quantify the influence of a number of these mining and geological factors and their inter-relationships. The factors investigated in this paper include longwall positional factors, horizontal stress, panel width, depth of cover and geological structures around the valley. It is found that mining in a series passing beneath the valley dramatically increases valley closure, and mining parallel to valley induces much more closure than other mining orientations. The redistribution of horizontal stress and influence of mining activity have also been recognised as important factors promoting valley closure, and the effect of geological structure around the valley is found to be relatively small. This paper provides further insight into both the valley closure mechanisms and how these mechanisms should be considered in valley closure prediction models.

  17. Mental health in Colombia

    PubMed Central

    Chaskel, Roberto; Gaviria, Silvia L.; Espinel, Zelde; Taborda, Eliana; Vanegas, Roland; Shultz, James M.

    2015-01-01

    A hallmark of Colombia is population-wide exposure to violence. To understand the realities of mental health in Colombia requires attention to the historical context of 60 years of unrelenting armed conflict overlaid upon high rates of homicide, gang activity and prevalent gender-based and intra-familial violence. The number of patients affected by trauma is extremely large, and the population burden of alcohol misuse and illicit drug use is significant. These patterns have brought the subspecialties of trauma and addiction psychiatry to the forefront, and highlight the need for novel treatments that integrate psychotherapeutic and psychopharmacological modalities. PMID:29093873

  18. The Inter-Valley Soil Comparative Survey: the ecology of Dry Valley edaphic microbial communities

    PubMed Central

    Lee, Charles K; Barbier, Béatrice A; Bottos, Eric M; McDonald, Ian R; Cary, Stephen Craig

    2012-01-01

    Recent applications of molecular genetics to edaphic microbial communities of the McMurdo Dry Valleys and elsewhere have rejected a long-held belief that Antarctic soils contain extremely limited microbial diversity. The Inter-Valley Soil Comparative Survey aims to elucidate the factors shaping these unique microbial communities and their biogeography by integrating molecular genetic approaches with biogeochemical analyses. Although the microbial communities of Dry Valley soils may be complex, there is little doubt that the ecosystem's food web is relatively simple, and evidence suggests that physicochemical conditions may have the dominant role in shaping microbial communities. To examine this hypothesis, bacterial communities from representative soil samples collected in four geographically disparate Dry Valleys were analyzed using molecular genetic tools, including pyrosequencing of 16S rRNA gene PCR amplicons. Results show that the four communities are structurally and phylogenetically distinct, and possess significantly different levels of diversity. Strikingly, only 2 of 214 phylotypes were found in all four valleys, challenging a widespread assumption that the microbiota of the Dry Valleys is composed of a few cosmopolitan species. Analysis of soil geochemical properties indicated that salt content, alongside altitude and Cu2+, was significantly correlated with differences in microbial communities. Our results indicate that the microbial ecology of Dry Valley soils is highly localized and that physicochemical factors potentially have major roles in shaping the microbiology of ice-free areas of Antarctica. These findings hint at links between Dry Valley glacial geomorphology and microbial ecology, and raise previously unrecognized issues related to environmental management of this unique ecosystem. PMID:22170424

  19. 27 CFR 9.132 - Rogue Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Rogue Valley. 9.132... Rogue Valley. (a) Name. The name of the viticultural area described in this section is “Rouge Valley.” (b) Approved map. The appropriate map for determining the boundaries of the Rogue Valley viticultural...

  20. Prevention of School Desertion in Colombia

    ERIC Educational Resources Information Center

    Walker, Sarah

    2004-01-01

    Colombia has been ravaged for over 40-years by escalating civil conflict and more than half of its population of 42 million live below the poverty line. As a result, many children and young people are excluded from school and drop out rates of those who gain places are high. It is in Bogota, the capital of Colombia, where many displaced families…

  1. Plan Colombia: The View from the Presidential Palace

    DTIC Science & Technology

    2001-05-01

    la violencia , in which liberals and conservatives kill each other in order to seize control of the government. Of course, there have been efforts to...Colombia for some 40 years. I have been in the Colombian Senate for 8 years. I’ve traveled all over Colombia. I’ve been familiar with Colombia’s...country because of la violencia in the early Fifties. Colombia, since the end of that unfortunate turn, has enjoyed a robust democratic system under which

  2. Hydrogeologic framework and estimates of groundwater storage for the Hualapai Valley, Detrital Valley, and Sacramento Valley basins, Mohave County, Arizona

    USGS Publications Warehouse

    Truini, Margot; Beard, L. Sue; Kennedy, Jeffrey; Anning, Dave W.

    2013-01-01

    We have investigated the hydrogeology of the Hualapai Valley, Detrital Valley, and Sacramento Valley basins of Mohave County in northwestern Arizona to develop a better understanding of groundwater storage within the basin fill aquifers. In our investigation we used geologic maps, well-log data, and geophysical surveys to delineate the sedimentary textures and lithology of the basin fill. We used gravity data to construct a basin geometry model that defines smaller subbasins within the larger basins, and airborne transient-electromagnetic modeled results along with well-log lithology data to infer the subsurface distribution of basin fill within the subbasins. Hydrogeologic units (HGUs) are delineated within the subbasins on the basis of the inferred lithology of saturated basin fill. We used the extent and size of HGUs to estimate groundwater storage to depths of 400 meters (m) below land surface (bls). The basin geometry model for the Hualapai Valley basin consists of three subbasins: the Kingman, Hualapai, and southern Gregg subbasins. In the Kingman subbasin, which is estimated to be 1,200 m deep, saturated basin fill consists of a mixture of fine- to coarse-grained sedimentary deposits. The Hualapai subbasin, which is the largest of the subbasins, contains a thick halite body from about 400 m to about 4,300 m bls. Saturated basin fill overlying the salt body consists predominately of fine-grained older playa deposits. In the southern Gregg subbasin, which is estimated to be 1,400 m deep, saturated basin fill is interpreted to consist primarily of fine- to coarse-grained sedimentary deposits. Groundwater storage to 400 m bls in the Hualapai Valley basin is estimated to be 14.1 cubic kilometers (km3). The basin geometry model for the Detrital Valley basin consists of three subbasins: northern Detrital, central Detrital, and southern Detrital subbasins. The northern and central Detrital subbasins are characterized by a predominance of playa evaporite and fine

  3. Fretted Terrain Valleys

    NASA Technical Reports Server (NTRS)

    2004-01-01

    30 October 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows shallow tributary valleys in the Ismenius Lacus fretted terrain region of northern Arabia Terra. These valleys exhibit a variety of typical fretted terrain valley wall and floor textures, including a lineated, pitted material somewhat reminiscent of the surface of a brain. Origins for these features are still being debated within the Mars science community; there are no clear analogs to these landforms on Earth. This image is located near 39.9oN, 332.1oW. The picture covers an area about 3 km (1.9 mi) wide. Sunlight illuminates the scene from the lower left.

  4. Guerrilla Violence in Colombia: Examining Causes and Consequences

    DTIC Science & Technology

    1994-06-01

    17 million at the end of 1931.4 The country along with most of 4 P caut, Daniel, Orden y Violencia: Colombia 1930-1954, Siglo veintiuno Editores, 1987...should no longer be a source of support for the masses.7 P0caut, Daniel, Orden y Violencia: Colombia 1930-1954, Siglo veintiuno Editores, 1987, p. 353. 14...Daniel, Orden y Violencia: Colombia 1930-1954, Siglo veintiuno Editores, 1987, p. 362. Ibid. 15 Gaitanism, the populist social movement led by Gait~n

  5. Geologic history of the Yosemite Valley

    USGS Publications Warehouse

    Matthes, Francois E.

    1930-01-01

    Projection of the longitudinal profiles of these hanging valleys forward to the axis of the Merced Canyon shows that they are closely accordant in height. Their profiles indicate a series of points on a former profile of the Merced with respect to which the side streams had graded their courses prior to the last uplift. This old profile can be extended upward into the glaciated part of the Merced Canyon above El Portal and even into the profoundly glaciated Yosemite Valley, accordant points being furnished by a number of hanging side valleys (due allowance being made for glacial erosion suffered by those valleys). However, not all the hanging valleys of the Yosemite region are accordant with this set. Several of them, including the upland valley of Yosemite Creek, constitute a separate set indicating another old profile of the Merced at a level 600 to 1,000 feet higher than the first. Others, including the hanging gulch of lower Bridalveil Creek, point to an old profile of the Merced about 1,200 feet lower than the first. There are thus three distinct sets of hanging valleys produced in three cycles of stream erosion. The valleys of the upper set, like those of the middle set, were left hanging as a result of rapid trenching by the Merced induced by an uplift of the range, there having been two such uplifts. Only the valleys of the lower set hang because of glacial deepening and widening of the Yosemite Valley, the cycle in which they were cut having been interrupted by the advent of the Pleistocene glaciers. They consequently indicate the preglacial depth of the Yosemite Valley. That depth, measured from the brow of El Capitan, was about 2,400 feet; measured from the rim at Glacier Point it was about 2,000 feet.

  6. 76 FR 22746 - Conecuh Valley Railway, LLC-Acquisition and Operation Exemption-Conecuh Valley Railroad Co., Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-22

    ... Railway, LLC--Acquisition and Operation Exemption--Conecuh Valley Railroad Co., Inc. Conecuh Valley Railway, LLC (CVR), a noncarrier, has filed a verified notice of exemption under 49 CFR 1150.31 to acquire from Conecuh Valley Railroad Co., Inc. (COEH), and to operate [[Page 22747

  7. The ant genus Linepithema (Formicidae: Dolichoderinae) in Colombia.

    PubMed

    Escárraga, Mayron; Guerrero, Roberto J

    2016-12-19

    The species of Linepithema Mayr in Colombia are reviewed from collection material. The genus Linepithema comprises 20 species, of which the following are reported in Colombia: L. angulatum (Emery), L. dispertitum (Forel), L. gallardoi (Brèthes), L. humile (Mayr), L. iniquum (Mayr), L. neotropicum Wild, L. piliferum (Mayr), L. tsachila Wild, and a new species, Linepithema hirsutum sp. nov. Linepithema dispertitum is a new record for Colombia and South America. A taxonomic key (English and Spanish) and distribution maps to the species of Linepithema in Colombia are provided.

  8. Local Climate Changes Forced by Changes in Land Use and topography in the Aburrá Valley, Colombia.

    NASA Astrophysics Data System (ADS)

    Zapata Henao, M. Z.; Hoyos Ortiz, C. D.

    2017-12-01

    One of the challenges in the numerical weather models is the adequate representation of soil-vegetation-atmosphere interaction at different spatial scales, including scenarios with heterogeneous land cover and complex mountainous terrain. The interaction determines the energy, mass and momentum exchange at the surface and could affect different variables including precipitation, temperature and wind. In order to quantify the long-term climate impact of changes in local land use and to assess the role of topography, two numerical experiments were examined. The first experiment allows assessing the continuous growth of urban areas within the Aburrá Valley, a complex terrain region located in Colombian Andes. The Weather Research Forecast model (WRF) is used as the basis of the experiment. The basic setup involves two nested domains, one representing the continental scale (18 km) and the other the regional scale (2 km). The second experiment allows drastic topography modification, including changing the valley configuration to a plateau. The control run for both experiments corresponds to a climatological scenario. In both experiments the boundary conditions correspond to the climatological continental domain output. Surface temperature, surface winds and precipitation are used as the main variables to compare both experiments relative to the control run. The results of the first experiment show a strong relationship between land cover and the variables, specially for surface temperature and wind speed, due to the strong forcing land cover imposes on the albedo, heat capacity and surface roughness, changing temperature and wind speed magnitudes. The second experiment removes the winds spatial variability related with hill slopes, the direction and magnitude are modulated only by the trade winds and roughness of land cover.

  9. Grizzly Valley fault system, Sierra Valley, CA

    USGS Publications Warehouse

    Gold, Ryan; Stephenson, William; Odum, Jack; Briggs, Rich; Crone, Anthony; Angster, Steve

    2012-01-01

    The Grizzly Valley fault system (GVFS) strikes northwestward across Sierra Valley, California and is part of a network of active, dextral strike-slip faults in the northern Walker Lane (Figure 1). To investigate Quaternary motion across the GVFS, we analyzed high-resolution (0.25 m) airborne LiDAR data (Figure 2) in combination with six, high-resolution, P-wave, seismic-reflection profiles [Gold and others, 2012]. The 0.5- to 2.0-km-long seismic-reflection profiles were sited orthogonal to suspected tectonic lineaments identified from previous mapping and our analysis of airborne LiDAR data. To image the upper 400–700 m of subsurface stratigraphy of Sierra Valley (Figure 3), we used a 230-kg accelerated weight drop source. Geophone spacing ranged from 2 to 5 m and shots were co-located with the geophones. The profiles reveal a highly reflective, deformed basal marker that we interpret to be the top of Tertiary volcanic rocks, overlain by a 120- to 300-m-thick suite of subhorizontal reflectors we interpret as Plio-Pleistocene lacustrine deposits. Three profiles image the principle active trace of the GVFS, which is a steeply dipping fault zone that offsets the volcanic rocks and the basin fill (Figures 4 & 5).

  10. Topological Valley Currents in Gapped Dirac Materials

    NASA Astrophysics Data System (ADS)

    Lensky, Yuri D.; Song, Justin C. W.; Samutpraphoot, Polnop; Levitov, Leonid S.

    2015-06-01

    Gapped 2D Dirac materials, in which inversion symmetry is broken by a gap-opening perturbation, feature a unique valley transport regime. Topological valley currents in such materials are dominated by bulk currents produced by electronic states just beneath the gap rather than by edge modes. The system ground state hosts dissipationless persistent valley currents existing even when topologically protected edge modes are absent. Valley currents induced by an external bias are characterized by a quantized half-integer valley Hall conductivity. The undergap currents dominate magnetization and the charge Hall effect in a light-induced valley-polarized state.

  11. Field Surveys, IOC Valleys. Volume III, Part II. Cultural Resources Survey, Pine and Wah Wah Valleys, Utah.

    DTIC Science & Technology

    1981-08-01

    valleys are typical of the Basin and Range Province, characterized by parallel, north-south trending mountain ranges, separated by hydrologically closed... basins . Pine and Wah Wah valleys each have hardpan-playas in their lowest areas. State Highway 21 runs roughly northwest-southeast through both val...have been important for prehis- toric and historic use of the area. Pine Valley: Pine and Wah Wah valleys are closed alluvial basins . The central part

  12. Epidemiology and control of malaria in Colombia

    PubMed Central

    Rodríguez, Julio Cesar Padilla; Uribe, Gilberto Álvarez; Araújo, Roberto Montoya; Narváez, Pablo Chaparro; Valencia, Sócrates Herrera

    2016-01-01

    Malaria is currently one of the most serious public health problems in Colombia with an endemic/epidemic transmission pattern that has maintained endemic levels and an average of 105,000 annual clinical cases being reported over the last five years. Plasmodium vivax accounts for approximately 70% of reported cases with the remainder attributed almost exclusively to Plasmodium falciparum. A limited number of severe and complicated cases have resulted in mortality, which is a downward trend that has been maintained over the last few years. More than 90% of the malaria cases in Colombia are confined to 70 municipalities (about 7% of the total municipalities of Colombia), with high predominance (85%) in rural areas. The purpose of this paper is to review the progress of malaria-eradication activities and control measures over the past century within the eco-epidemiologic context of malaria transmission together with official consolidated morbidity and mortality reports. This review may contribute to the formulation of new antimalarial strategies and policies intended to achieve malaria elimination/eradication in Colombia and in the region. PMID:21881765

  13. A landscape scale valley confinement algorithm: Delineating unconfined valley bottoms for geomorphic, aquatic, and riparian applications

    Treesearch

    David E. Nagel; John M. Buffington; Sharon L. Parkes; Seth Wenger; Jaime R. Goode

    2014-01-01

    Valley confinement is an important landscape characteristic linked to aquatic habitat, riparian diversity, and geomorphic processes. This report describes a GIS program called the Valley Confinement Algorithm (VCA), which identifies unconfined valleys in montane landscapes. The algorithm uses nationally available digital elevation models (DEMs) at 10-30 m resolution to...

  14. Graphene Nanobubbles as Valley Filters and Beam Splitters

    NASA Astrophysics Data System (ADS)

    Settnes, Mikkel; Power, Stephen R.; Brandbyge, Mads; Jauho, Antti-Pekka

    2016-12-01

    The energy band structure of graphene has two inequivalent valleys at the K and K' points of the Brillouin zone. The possibility to manipulate this valley degree of freedom defines the field of valleytronics, the valley analogue of spintronics. A key requirement for valleytronic devices is the ability to break the valley degeneracy by filtering and spatially splitting valleys to generate valley polarized currents. Here, we suggest a way to obtain valley polarization using strain-induced inhomogeneous pseudomagnetic fields (PMFs) that act oppositely on the two valleys. Notably, the suggested method does not involve external magnetic fields, or magnetic materials, unlike previous proposals. In our proposal the strain is due to experimentally feasible nanobubbles, whose associated PMFs lead to different real space trajectories for K and K' electrons, thus allowing the two valleys to be addressed individually. In this way, graphene nanobubbles can be exploited in both valley filtering and valley splitting devices, and our simulations reveal that a number of different functionalities are possible depending on the deformation field.

  15. Colombia Country Analysis Brief

    EIA Publications

    2016-01-01

    Colombia is South America's largest coal producer, and the region's third-largest oil producer after Venezuela and Brazil. In 2015, Colombia was the world's fifth-largest coal exporter. The country is also a significant oil exporter, ranking as the fifth-largest crude oil exporter to the United States in 2015. A series of regulatory reforms enacted in 2003 makes the oil and natural gas sector more attractive to foreign investors led to an increase in Colombian oil and natural gas production. The Colombian government implemented a partial privatization of state oil company Ecopetrol (formerly known as Empresa Colombiana de Petróleos S.A.) in an attempt to revive its upstream oil industry.

  16. The Long Valley Caldera GIS database

    USGS Publications Warehouse

    Battaglia, Maurizio; Williams, M.J.; Venezky, D.Y.; Hill, D.P.; Langbein, J.O.; Farrar, C.D.; Howle, J.F.; Sneed, M.; Segall, P.

    2003-01-01

    This database provides an overview of the studies being conducted by the Long Valley Observatory in eastern California from 1975 to 2001. The database includes geologic, monitoring, and topographic datasets related to Long Valley caldera. The CD-ROM contains a scan of the original geologic map of the Long Valley region by R. Bailey. Real-time data of the current activity of the caldera (including earthquakes, ground deformation and the release of volcanic gas), information about volcanic hazards and the USGS response plan are available online at the Long Valley observatory web page (http://lvo.wr.usgs.gov). If you have any comments or questions about this database, please contact the Scientist in Charge of the Long Valley observatory.

  17. 27 CFR 9.78 - Ohio River Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ohio River Valley. 9.78... River Valley. (a) Name. The name of the viticultural area described in this section is “Ohio River Valley.” (b) Approved maps. The approved maps for determining the boundary of the Ohio River Valley...

  18. The public health context of violence in Colombia.

    PubMed

    Garfield, Richard; Llanten Morales, Claudia Patricia

    2004-10-01

    Among the countries of the Americas, Colombia has the highest level of deaths due to homicides and armed conflict. The objective of this research was to combine and contrast information from various sources on deaths due to violence in Colombia in order to identify major trends in violence in the country and to compare those trends with those in other nations of the Americas. We drew together information from a wide array of sources, including the Government of Colombia, Colombian forensic institutions, nongovernmental organizations, and international research centers. We considered the impact of the violence on mortality as well as in such areas as nonfatal injuries, displacement of persons, and kidnappings. While there have been many deaths in Colombia directly related to military conflict, there have been many more deaths and injuries as an indirect result of war. The highest levels of deaths directly related to violence occurred during the 1990-1995 period. Although deaths due directly to armed conflict declined in the late 1990s, the related events of kidnappings and displacement did not. Efforts to reduce the violence-related suffering in Colombia must consider both direct and indirect causes of mortality as well as nonfatal outcomes such as kidnappings and displacement.

  19. Valley dependent transport in graphene L junction

    NASA Astrophysics Data System (ADS)

    Chan, K. S.

    2018-05-01

    We studied the valley dependent transport in graphene L junctions connecting an armchair lead and a zigzag lead. The junction can be used in valleytronic devices and circuits. Electrons injected from the armchair lead into the junction is not valley polarized, but they can become valley polarized in the zigzag lead. There are Fermi energies, where the current in the zigzag lead is highly valley polarized and the junction is an efficient generator of valley polarized current. The features of the valley polarized current depend sensitively on the widths of the two leads, as well as the number of dimers in the armchair lead, because this number has a sensitive effect on the band structure of the armchair lead. When an external potential is applied to the junction, the energy range with high valley polarization is enlarged enhancing its function as a generator of highly valley polarized current. The scaling behavior found in other graphene devices is also found in L junctions, which means that the results presented here can be extended to junctions with larger dimensions after appropriate scaling of the energy.

  20. Down in the Valley.

    ERIC Educational Resources Information Center

    Salter, Linda Graef

    1999-01-01

    Describes the partnerships formed by West Valley Mission Community College District (California) with its surrounding Silicon Valley business community in an effort to benefit workforce development. Asserts that community colleges are uniquely positioned to provide a lifelong education that will yield a skilled workforce to meet the needs of…

  1. Hazardous Waste Cleanup: West Valley Demonstration Project USDOE in West Valley, New York

    EPA Pesticide Factsheets

    The U.S. Department of Energy's West Valley Demonstration Project is located at 10282 Rock Spring Road in West Valley, New York. This is a 167 acre, Department of Energy (DOE)-operated portion of a 3,300-acre site owned by the New York State Energy

  2. Rift Valley Fever Virus

    USDA-ARS?s Scientific Manuscript database

    Rift Valley fever virus (RVFV) is a mosquito-transmitted virus or arbovirus that is endemic in sub-Saharan Africa. In the last decade, Rift Valley fever (RVF) outbreaks have resulted in loss of human and animal life, as well as had significant economic impact. The disease in livestock is primarily a...

  3. Situation Report--Colombia.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    Data relating to population and family planning in Colombia are presented in this situation report. Information is provided, where appropriate and available, under two topics, general background and family planning situation. General background covers ethnic groups, language, religion, economy, communication/education, medical/social welfare, and…

  4. An evaluation of Skylab (EREP) remote sensing techniques applied to investigation of crustal structure. [Death Valley and Greenwater Valley (CA)

    NASA Technical Reports Server (NTRS)

    Bechtold, I. C. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. A study of Greenwater Valley indicates that the valley is bounded on the north and east by faults, on the south by a basement high, and on the west by the dip slope of the black mountains, movement of ground water from the valley is thus Movement of ground water from the valley is thus restricted, indicating the valley is a potential water reservoir.

  5. Phylogenetic evidence of a new canine distemper virus lineage among domestic dogs in Colombia, South America.

    PubMed

    Espinal, Maria A; Díaz, Francisco J; Ruiz-Saenz, Julian

    2014-08-06

    Canine distemper virus (CDV) is a highly contagious viral disease of carnivores affecting both wild and domestic populations. The hemagglutinin gene, encoding for the attachment protein that determines viral tropism, shows high heterogeneity among strains, allowing for the distinction of ten different lineages distributed worldwide according to a geographic pattern. We obtained the sequences of the full-length H gene of 15 wild-type CDV strains circulating in domestic dog populations from the Aburrá Valley, Colombia. A phylogenetic analysis of H gene nucleotide sequences from Colombian CDV viruses along with field isolates from different geographic regions and vaccine strains was performed. Colombian wild-type viruses formed a distinct monophyletic cluster clearly separated from the previously identified wild-type and vaccine lineages, suggesting that a novel genetic variant, quite different from vaccines and other lineages, is circulating among dog populations in the Aburrá Valley. We propose naming this new lineage as "South America 3". This information indicates that there are at least three different CDV lineages circulating in domestic and wild carnivore populations in South America. The first one, renamed Europe/South America 1, circulates in Brazil and Uruguay; the second, South America 2, appears to be restricted to Argentina; and the third, South America 3, which comprises all the strains characterized in this study, may also be circulating in other northern countries of South America. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. 27 CFR 9.154 - Chiles Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Chiles Valley. (a) Name. The name of the viticultural area described in this section is “Chiles Valley... viticultural area are four 1:24,000 Scale U.S.G.S. topography maps. They are titled: (1) St. Helena, CA 1960 photorevised 1980; (2) Rutherford, CA 1951 photorevised 1968; (3) Chiles Valley, CA 1958 photorevised 1980; (4...

  7. Meter-Scale Characteristics of Martian Channels and Valleys

    USGS Publications Warehouse

    Carr, M.H.; Malin, M.C.

    2000-01-01

    Mars Global Surveyor images, with resolutions as high as 1.5 m pixel, enable characterization of martian channels and valleys at resolutions one to two orders of magnitude better than was previously possible. A major surprise is the near-absence of valleys a few hundred meters wide and narrower. The almost complete absence of fine-scale valleys could be due to lack of precipitation, destruction of small valleys by erosion, or dominance of infiltration over surface runoff. V-shaped valleys with a central channel, such as Nanedi Vallis, provide compelling evidence for sustained or episodic flow of water across the surface. Larger valleys appear to have formed not by headward erosion as a consequence of groundwater sapping but by erosion from water sources upstream of the observed sections. The freshest appearing valleys have triangular cross sections, with talus from opposing walls meeting at the center of the valley. The relations suggest that the width of the valleys is controlled by the depth of incision and the angle of repose of the walls. The flat floors of less fresh-appearing valleys result primarily from later eolian fill. Several discontinuous valleys and lines of craters suggest massive subsurface solution or erosion. The climatic implications of the new images will remain obscure until the cause for the scarcity of fine-scale dissection is better understood. ?? 2000 Academic Press.

  8. Microscopic Identification of Prokaryotes in Modern and Ancient Halite, Saline Valley and Death Valley, California

    NASA Astrophysics Data System (ADS)

    Schubert, Brian A.; Lowenstein, Tim K.; Timofeeff, Michael N.

    2009-06-01

    Primary fluid inclusions in halite crystallized in Saline Valley, California, in 1980, 2004-2005, and 2007, contain rod- and coccoid-shaped microparticles the same size and morphology as archaea and bacteria living in modern brines. Primary fluid inclusions from a well-dated (0-100,000 years), 90 m long salt core from Badwater Basin, Death Valley, California, also contain microparticles, here interpreted as halophilic and halotolerant prokaryotes. Prokaryotes are distinguished from crystals on the basis of morphology, optical properties (birefringence), and uniformity of size. Electron micrographs of microparticles from filtered modern brine (Saline Valley), dissolved modern halite crystals (Saline Valley), and dissolved ancient halite crystals (Death Valley) support in situ microscopic observations that prokaryotes are present in fluid inclusions in ancient halite. In the Death Valley salt core, prokaryotes in fluid inclusions occur almost exclusively in halite precipitated in perennial saline lakes 10,000 to 35,000 years ago. This suggests that trapping and preservation of prokaryotes in fluid inclusions is influenced by the surface environment in which the halite originally precipitated. In all cases, prokaryotes in fluid inclusions in halite from the Death Valley salt core are miniaturized (<1 μm diameter cocci, <2.5 μm long, very rare rod shapes), which supports interpretations that the prokaryotes are indigenous to the halite and starvation survival may be the normal response of some prokaryotes to entrapment in fluid inclusions for millennia. These results reinforce the view that fluid inclusions in halite and possibly other evaporites are important repositories of microbial life and should be carefully examined in the search for ancient microorganisms on Earth, Mars, and elsewhere in the Solar System.

  9. Valley Vortex States in Sonic Crystals

    NASA Astrophysics Data System (ADS)

    Lu, Jiuyang; Qiu, Chunyin; Ke, Manzhu; Liu, Zhengyou

    2016-03-01

    Valleytronics is quickly emerging as an exciting field in fundamental and applied research. In this Letter, we study the acoustic version of valley states in sonic crystals and reveal a vortex nature of such states. In addition to the selection rules established for exciting valley polarized states, a mimicked valley Hall effect of sound is proposed further. The extraordinary chirality of valley vortex states, detectable in experiments, may open a new possibility in sound manipulations. This is appealing to scalar acoustics that lacks a spin degree of freedom inherently. In addition, the valley selection enables a handy way to create vortex matter in acoustics, in which the vortex chirality can be controlled flexibly. Potential applications can be anticipated with the exotic interaction of acoustic vortices with matter, such as to trigger the rotation of the trapped microparticles without contact.

  10. Topological Valley Transport in Two-dimensional Honeycomb Photonic Crystals.

    PubMed

    Yang, Yuting; Jiang, Hua; Hang, Zhi Hong

    2018-01-25

    Two-dimensional photonic crystals, in analogy to AB/BA stacking bilayer graphene in electronic system, are studied. Inequivalent valleys in the momentum space for photons can be manipulated by simply engineering diameters of cylinders in a honeycomb lattice. The inequivalent valleys in photonic crystal are selectively excited by a designed optical chiral source and bulk valley polarizations are visualized. Unidirectional valley interface states are proved to exist on a domain wall connecting two photonic crystals with different valley Chern numbers. With the similar optical vortex index, interface states can couple with bulk valley polarizations and thus valley filter and valley coupler can be designed. Our simple dielectric PC scheme can help to exploit the valley degree of freedom for future optical devices.

  11. Potential Distribution of Chagas Disease Vectors (Hemiptera, Reduviidae, Triatominae) in Colombia, Based on Ecological Niche Modeling

    PubMed Central

    Suárez-Escudero, Laura C.; González-Caro, Sebastián

    2016-01-01

    Ecological niche modeling of Triatominae bugs allow us to establish the local risk of transmission of the parasite Trypanosoma cruzi, which causes Chagas disease. This information could help to guide health authority recommendations on infection monitoring, prevention, and control. In this study, we estimated the geographic distribution of triatomine species in Colombia and identified the relationship between landscape structure and climatic factors influencing their occurrence. A total of 2451 records of 4 triatomine species (Panstrongylus geniculatus, Rhodnius pallescens, R. prolixus, and Triatoma maculata) were analyzed. The variables that provided more information to explain the ecologic niche of these vectors were related to precipitation, altitude, and temperature. We found that the species with the broadest potential geographic distribution were P. geniculatus, R. pallescens, and R. prolixus. In general, the models predicted the highest occurrence probability of these vectors in the eastern slope of the Eastern Cordillera, the southern region of the Magdalena valley, and the Sierra Nevada of Santa Marta. PMID:28115946

  12. Potential Distribution of Chagas Disease Vectors (Hemiptera, Reduviidae, Triatominae) in Colombia, Based on Ecological Niche Modeling.

    PubMed

    Parra-Henao, Gabriel; Suárez-Escudero, Laura C; González-Caro, Sebastián

    2016-01-01

    Ecological niche modeling of Triatominae bugs allow us to establish the local risk of transmission of the parasite Trypanosoma cruzi, which causes Chagas disease. This information could help to guide health authority recommendations on infection monitoring, prevention, and control. In this study, we estimated the geographic distribution of triatomine species in Colombia and identified the relationship between landscape structure and climatic factors influencing their occurrence. A total of 2451 records of 4 triatomine species ( Panstrongylus geniculatus , Rhodnius pallescens , R. prolixus , and Triatoma maculata ) were analyzed. The variables that provided more information to explain the ecologic niche of these vectors were related to precipitation, altitude, and temperature. We found that the species with the broadest potential geographic distribution were P. geniculatus , R. pallescens , and R. prolixus . In general, the models predicted the highest occurrence probability of these vectors in the eastern slope of the Eastern Cordillera, the southern region of the Magdalena valley, and the Sierra Nevada of Santa Marta.

  13. Optical tuning of electronic valleys (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Sie, Edbert J.; Gedik, Nuh

    2017-02-01

    Monolayer transition-metal dichalcogenides such as MoS2 and WS2 are prime examples of atomically thin semiconducting crystals that exhibit remarkable electronic and optical properties. They have a pair of valleys that can serve as a new electronic degree of freedom, and these valleys obey optical selection rules with circularly polarized light. Here, we discuss how ultrafast laser pulses can be used to tune their energy levels in a controllable valley-selective manner. The energy tunability is extremely large, comparable to what would be obtained using a hundred Tesla of magnetic field. We will also show that such valley tunability can be performed while we effectively manipulate the valley selection rules. Finally, we will explore the prospect of using this technique through photoemission spectroscopy to create a new phase of matter called a valley Floquet topological insulator.

  14. State of emergency medicine in Colombia.

    PubMed

    Arbelaez, Christian; Patiño, Andrés

    2015-01-01

    Colombia is an upper-middle-income country with a population of 45 million people and one of the best national healthcare and medical education systems in South America. However, its widely diverse and difficult terrains hinder healthcare delivery to rural areas, creating disparities in healthcare access and outcomes between the urban and rural settings. Currently, emergency medical care is overwhelmingly provided by general practitioners without residency training, who obtain specialty consultations based on the medical/surgical condition identified. A few emergency medicine (EM) residency programs have sprouted over the last two decades in renowned academic institutions in the largest cities, producing high-quality EM specialists. With the establishment of EM as a specialty in 2005 and increasing recognition of the specialty, there has been an increasing demand for EM specialists in cities, which is only slowly being met by the current residencies. The critical challenges for EM in Colombia are both, establishing itself as a well-recognized specialty - by increasing academic production and reaching a critical mass of and unity among EM specialists - and providing the highest quality and safest emergency care to the people of Colombia - by improving capacity both in emergency departments and in the regional and national emergency response systems. Historically, the establishment of EM as a strongly organized specialty in other countries has spanned decades (e.g., the United States), and Colombia has been making significant progress in a similar trajectory.

  15. Martian oceans, valleys and climate

    USGS Publications Warehouse

    Carr, M.H.

    2000-01-01

    The new Mars Global Surveyor altimetry shows that the heavily cratered southern hemisphere of Mars is 5 km higher that the sparely cratered plains of the northern hemisphere. Previous suggestions that oceans formerly occupied that northern plains as evidenced by shorelines are partly supported by the new data. A previously identified outer boundary has a wide range of elevations and is unlikely to be a shoreline but an inner contact with a narrow range of elevations is a more likely candidate. No shorelines are visible in the newly acquired, 2.5 metre/pixel imaging. Newly imaged valleys provide strong support for sustained or episodic flow of water across the Martian surface. A major surprise, however, is the near absence of valleys less than 100 m across. Martian valleys seemingly do not divide into ever smaller valleys as terrestrial valleys commonly do. This could be due to lack of precipitation or lack of surface runoff because of high infiltration rates. High erosion rates and supports warm climates and presence of large bodies of water during heavy bombardment. The climate history and fate of the water after heavy bombardment remain cotroversial.

  16. Knickpoints and Hanging Valleys of Licus Vallis, Mars

    NASA Astrophysics Data System (ADS)

    Goudge, T. A.; Fassett, C.

    2016-12-01

    Licus Vallis is a 350 km long valley system located along the dichotomy boundary on Mars. The main trunk of the valley is incised 200-700 m into the surrounding terrain. The valley heads at an outlet breach of a shallow, 30 km diameter impact crater, and is also fed by a system of tributaries incised into the plateau surrounding Licus Vallis. Many of the tributary valleys, as well as the main stem of the valley fed by the paleolake outlet, have profiles that are not smoothly graded, but rather have distinct reaches with concave downward topography. These sections are either knickpoints or hanging valleys that develop in response to changes in the effective local base level, changes in climate conditions during incision of the valley, or lithologic boundaries in the substrate. Here we present remote sensing observations from images and topography to test these competing hypotheses and further characterize the evolution of this large valley system. Slope-watershed area relationships for the tributaries and main trunk valley are used to distinguish between knickpoints and hanging valleys. Analysis of orbital images does not reveal any distinct layer above which knickpoints develop, and the elevation of knickpoints show no systematic trends that might be expected of a regional lithologic unit(s). Our preliminary results suggest that the distance of knickpoint retreat is correlated with the position of the tributary valley and not the watershed area. Downstream valleys have retreated the most, suggesting they have had the most time to adjust to lowering of the local base level associated with incision of the main valley. These results are most consistent with a wave of incision sweeping up the valley system as it adjusts to a low base level in the northern plains. This conclusion is also consistent with observations of the incision depth of Licus Vallis, which increases approximately linearly downstream. Understanding this signature of base level control on the incision

  17. Magnetic control of valley pseudospin in monolayer WSe 2

    DOE PAGES

    Aivazian, G.; Gong, Zhirui; Jones, Aaron M.; ...

    2015-01-26

    Local energy extrema of the bands in momentum space, or valleys, can endow electrons in solids with pseudo-spin in addition to real spin 1-5. In transition metal dichalcogenides this valley pseudo-spin, like real spin, is associated with a magnetic moment1,6 which underlies the valley-dependent circular dichroism 6 that allows optical generation of valley polarization 7-9, intervalley quantum coherence 10, and the valley Hall effect 11. However, magnetic manipulation of valley pseudospin via this magnetic moment 12-13, analogous to what is possible with real spin, has not been shown before. Here we report observation of the valley Zeeman splitting and magneticmore » tuning of polarization and coherence of the excitonic valley pseudospin, by performing polarization-resolved magneto-photoluminescence on monolayer WSe 2. Our measurements reveal both the atomic orbital and lattice contributions to the valley orbital magnetic moment; demonstrate the deviation of the band edges in the valleys from an exact massive Dirac fermion model; and reveal a striking difference between the magnetic responses of neutral and charged valley excitons which is explained by renormalization of the excitonic spectrum due to strong exchange interactions.« less

  18. Spin and valley filter across line defect in silicene

    NASA Astrophysics Data System (ADS)

    Wang, Sake; Ren, Chongdan; Li, Yunfang; Tian, Hongyu; Lu, Weitao; Sun, Minglei

    2018-05-01

    We propose a new scheme to achieve an effective spin/valley filter in silicene with extended line defect on the basis of spin–valley coupling due to the intrinsic spin-orbit coupling (SOC). The transmission coefficient of the spin/valley states is seriously affected by the SOC. When a perpendicular magnetic field is applied on one side of the line defect, one valley state will experience backscattering, but the other valley will not; this leads to high valley polarization in all transmission directions. Moreover, the spin/valley polarization can be enhanced to 96% with the aid of a perpendicular electric field.

  19. Astronomy in Colombia

    NASA Astrophysics Data System (ADS)

    Higuera-G., Mario A.

    2017-07-01

    More than two centuries ago, José Celestino Mutis and Francisco José de Caldas initiated the Colombian Astronomical Expedition. Today, Colombia has a community of over 50 scientists, linked to six institutions nationwide, and more than 250 students and researchers (PhDs and Postdocs), having high-impact astronomical research around the world.

  20. New records of Anastrepha (Diptera: Tephritidae) primarily from Colombia

    USDA-ARS?s Scientific Manuscript database

    New distribution information, primarily from Colombia, is provided for 60 species of Anastrepha, including the first records of 32 species from Colombia: A. acca Norrbom, A. acris Stone, A. amita Zucchi, A. amplidentata Norrbom, A. atrox (Aldrich), A. barbiellinii Lima, A. bezzii Lima, A. canalis St...

  1. Toward Middle-Level Manpower Education for Colombia. A Report to USAID Colombia.

    ERIC Educational Resources Information Center

    Johnson, B. Lamar

    Education for middle-level manpower, a high-priority need in Colombia, is discussed. The current programs of five educational agencies--universities, university institutes, SENA (National Apprentice Service), industrial schools, and agricultural schools--that are providing some preparation for middle-level manpower positions are described. A…

  2. 27 CFR 9.36 - McDowell Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....” (b) Approved maps. The appropriate map for determining the boundaries of the McDowell Valley... and the ridge line (highest elevation line) between the McDowell Creek Valley and the Dooley Creek Valley. (3) Then southeasterly along the ridge line (highest elevation line) to the intersection of the...

  3. 27 CFR 9.36 - McDowell Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ....” (b) Approved maps. The appropriate map for determining the boundaries of the McDowell Valley... and the ridge line (highest elevation line) between the McDowell Creek Valley and the Dooley Creek Valley. (3) Then southeasterly along the ridge line (highest elevation line) to the intersection of the...

  4. Unanswered Questions in Colombia's Foreign Language Education Policy (Preguntas por responder en la política educativa de lenguas extranjeras en Colombia)

    ERIC Educational Resources Information Center

    Bonilla Carvajal, Camilo Andrés; Tejada-Sánchez, Isabel

    2016-01-01

    Following the trend of much of the Western, non-English speaking world, Colombia has tirelessly strived for spreading English education in an effort to augment economic benefits. This paper aims at providing a critical account of foreign language education policy in Colombia, with special attention to English. It outlines the impact of its…

  5. Valley Near Nilus Chaos

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-504, 5 October 2003

    This August 2003 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a valley near Nilus Chaos, around 25.2oN, 80.3oW. The scene has a uniform albedo, indicating that all of the landforms are probably mantled by fine, bright dust. Dark streaks on the valley walls indicate places where recent dust avalanches have occurred. The ripple-like dune features on the valley floor were formed by wind, but today they are inactive and covered with dust. A few craters, created by impacting debris, have formed on the dunes, again attesting to their inactivity in the modern martian environment. The image covers an area 3 km (1.9 mi) wide; it is illuminated by sunlight from the lower left.

  6. [Suicide trends in Colombia, 1985-2002].

    PubMed

    Cendales, Ricardo; Vanegas, Claudia; Fierro, Marco; Córdoba, Rodrigo; Olarte, Ana

    2007-10-01

    To report trends in mortality from suicide in Colombia from 1985 to 2002 by sex, age group, and method, and determine the number of Years of Potential Life Lost (YPLL) to suicide during this period. Age- and sex-specific and age-adjusted crude mortality rates were calculated based on mortality and population information available from the official database of the Department of National Statistics Administration, Colombia. YPLL were estimated and adjusted for societal impact, age, and poor quality of mortality records. The results were tabulated according to codes X600-X849 and Y870 from the International Statistical Classification of Disease and Related Health Problems, 10th revision (ICD-10), and codes E950-E959 from the 9th revision (ICD-9). Suicide rates have been climbing in Colombia since 1998, particularly among young adults and males. The highest rates among males were in the age groups 20-29 years of age and over 70 years of age, and rates increased over time. Among females, the highest rates were recorded for the group 10-19 years of age. The YPLL rose in proportion with the increase in suicides, from 0.81% in 1981 to 2.20% in 2002. Among males, the most common methods used were firearms and explosives, hanging, and poison, with a relative increase in hanging; whereas among females, poison was most common. A rising trend in suicide rates in Colombia was confirmed, especially among the productive segment of the population, which has resulted in a marked increase in YPLL.

  7. 78 FR 72972 - Meeting of the United States-Colombia Environmental Affairs Council and Environmental Cooperation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-04

    ... DEPARTMENT OF STATE [Public Notice 8541] Meeting of the United States-Colombia Environmental... Colombia intend to hold the first meeting of the Environmental Affairs Council (the ``Council'') and the... States- Colombia Trade Promotion Agreement (TPA) and the United States-Colombia Environmental Cooperation...

  8. 27 CFR 9.194 - San Antonio Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... significance. (b) Approved Maps. The appropriate maps for determining the boundary of the San Antonio Valley...) Hames Valley, California, 1949, photorevised 1978; (2) Tierra Redonda Mountain, California, 1949... southeast corner of section 14, T23S, R9E, on the Hames Valley map; (2) From the beginning point, proceed...

  9. Morning Transition Tracer Experiments in a Deep Narrow Valley.

    NASA Astrophysics Data System (ADS)

    Whiteman, C. David

    1989-07-01

    Three sulfur hexafluoride atmospheric tracer experiments were conducted during the post-sunrise temperature inversion breakup period in the deep, narrow Brush Creek Valley of Colorado. Experiments were conducted under clear, undisturbed weather conditions.A continuous elevated tracer plume was produced along the axis of the valley before sunrise and the behavior of the plume during the inversion breakup period was detected down-valley from the release point using an array of radio-controlled sequential bag samplers, a vertical SF6 profiling system carried on a tethered balloon, two portable gas chromatographs operated on a sidewall of the valley, and a continuous real-time SF6 monitor operated from a research aircraft. Supporting meteorological data came primarily from tethered balloon profilers. The nocturnal elevated plume was carried and diffused in down-valley flows. After sunrise, convective boundary layers grew upward from the sunlit valley surfaces, fumigating the elevated plume onto the valley floor and sidewalls. Upslope flow developed in the growing convective boundary layers, carrying fumigated SF6 up the sidewalls and causing a compensating subsidence over the valley center. High post-sunrise SF6 concentrations were experienced on the northeast-facing sidewall of the northwest-southeast oriented valley as a result of cross-valley flow, which developed due to differential solar heating of the sidewalls. Reversal of the down-valley wind system brought air with lower SF6 concentrations into the lower valley.

  10. The Central Valley Hydrologic Model

    NASA Astrophysics Data System (ADS)

    Faunt, C.; Belitz, K.; Hanson, R. T.

    2009-12-01

    Historically, California’s Central Valley has been one of the most productive agricultural regions in the world. The Central Valley also is rapidly becoming an important area for California’s expanding urban population. In response to this competition for water, a number of water-related issues have gained prominence: conjunctive use, artificial recharge, hydrologic implications of land-use change, subsidence, and effects of climate variability. To provide information to stakeholders addressing these issues, the USGS made a detailed assessment of the Central Valley aquifer system that includes the present status of water resources and how these resources have changed over time. The principal product of this assessment is a tool, referred to as the Central Valley Hydrologic Model (CVHM), that simulates surface-water flows, groundwater flows, and land subsidence in response to stresses from human uses and from climate variability throughout the entire Central Valley. The CVHM utilizes MODFLOW combined with a new tool called “Farm Process” to simulate groundwater and surface-water flow, irrigated agriculture, land subsidence, and other key processes in the Central Valley on a monthly basis. This model was discretized horizontally into 20,000 1-mi2 cells and vertically into 10 layers ranging in thickness from 50 feet at the land surface to 750 feet at depth. A texture model constructed by using data from more than 8,500 drillers’ logs was used to estimate hydraulic properties. Unmetered pumpage and surface-water deliveries for 21 water-balance regions were simulated with the Farm Process. Model results indicate that human activities, predominately surface-water deliveries and groundwater pumping for irrigated agriculture, have dramatically influenced the hydrology of the Central Valley. These human activities have increased flow though the aquifer system by about a factor of six compared to pre-development conditions. The simulated hydrology reflects spatial

  11. NV PFA - Steptoe Valley

    DOE Data Explorer

    Jim Faulds

    2015-10-29

    All datasets and products specific to the Steptoe Valley model area. Includes a packed ArcMap project (.mpk), individually zipped shapefiles, and a file geodatabase for the northern Steptoe Valley area; a GeoSoft Oasis montaj project containing GM-SYS 2D gravity profiles along the trace of our seismic reflection lines; a 3D model in EarthVision; spreadsheet of links to published maps; and spreadsheets of well data.

  12. 27 CFR 9.27 - Lime Kiln Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Lime Kiln Valley. 9.27... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.27 Lime Kiln Valley. (a) Name. The name of the viticultural area described in this section is “Lime Kiln Valley...

  13. Valley Pearl’ table grape

    USDA-ARS?s Scientific Manuscript database

    Valley Pearl’ is an early to mid-season, white seedless table grape (Vitis vinifera L.) suitable for commercial table grape production where V. vinifera can be grown. Significant characteristics of ‘Valley Pearl’ are its high and consistent fruit production on spur pruned vines and large round berr...

  14. Extraction of Martian valley networks from digital topography

    NASA Technical Reports Server (NTRS)

    Stepinski, T. F.; Collier, M. L.

    2004-01-01

    We have developed a novel method for delineating valley networks on Mars. The valleys are inferred from digital topography by an autonomous computer algorithm as drainage networks, instead of being manually mapped from images. Individual drainage basins are precisely defined and reconstructed to restore flow continuity disrupted by craters. Drainage networks are extracted from their underlying basins using the contributing area threshold method. We demonstrate that such drainage networks coincide with mapped valley networks verifying that valley networks are indeed drainage systems. Our procedure is capable of delineating and analyzing valley networks with unparalleled speed and consistency. We have applied this method to 28 Noachian locations on Mars exhibiting prominent valley networks. All extracted networks have a planar morphology similar to that of terrestrial river networks. They are characterized by a drainage density of approx.0.1/km, low in comparison to the drainage density of terrestrial river networks. Slopes of "streams" in Martian valley networks decrease downstream at a slower rate than slopes of streams in terrestrial river networks. This analysis, based on a sizable data set of valley networks, reveals that although valley networks have some features pointing to their origin by precipitation-fed runoff erosion, their quantitative characteristics suggest that precipitation intensity and/or longevity of past pluvial climate were inadequate to develop mature drainage basins on Mars.

  15. Dynamics of Katabatic Winds in Colorado' Brush Creek Valley.

    NASA Astrophysics Data System (ADS)

    Vergeiner, I.; Dreiseitl, E.; Whiteman, C. David

    1987-01-01

    A method is proposed to evaluate the coupled mass, momentum and thermal energy budget equations for a deep valley under two-dimensional, steady-state flow conditions. The method requires the temperature, down- valley wind and valley width fields to be approximated by simple analytical functions. The vertical velocity field is calculated using the mass continuity equation. Advection terms in the momentum and energy equations are then calculated using finite differences computed on a vertical two-dimensional grid that runs down the valley's axis. The pressure gradient term in the momentum equation is calculated from the temperature field by means of the hydrostatic equation. The friction term is then calculated as a residual in the xmomentum equation, and the diabatic cooling term is calculated as a residual in the thermal energy budget equation.The method is applied to data from an 8-km-long segment of Colorado's; Brush Creek Valley on the night of 30-31 July 1982. Pressure decreased with distance down the peak on horizontal surfaces, with peak horizontal pressure gradients of 0.04 hPa km1. The valley mass budget indicated that subsidence was required in the valley to support calculated mean along-valley mass flux divergence. Peak subsidence rates on the order of 0.10 m s1 were calculated. Subsiding motions in the valley produced negative vertical down-valley momentum fluxes in the upper valley atmosphere, but produced positive down-valley momentum fluxes below the level of the jet. Friction, calculated as a residual in the x momentum equation, was negative, as expected on physical grounds. and attained reasonable quantitative values.The strong subsidence field in the stable valley atmosphere produced subsidence warming that was only partly counteracted by down-valley cold air advection. Strong diabatic cooling was therefore required in order to account for the weak net cooling of the valley atmosphere during the nighttime period when tethered balloon observations

  16. Viva Colombia/Colombia Viva! A Fantasy Trip for the Five Senses

    ERIC Educational Resources Information Center

    de Ramirez, Lori Langer

    2006-01-01

    In the author's experience, Colombia is among the most misunderstood Spanish-speaking countries. Most of the news about Columbia involves drug trafficking or guerilla warfare, due to the many social and political problems that face the country. It is rare that the public is informed about the culture and people of this beautiful South American…

  17. Fretted Terrain Valley in Coloe Fossae Region

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Figure 1 Click on image for larger version

    The image in figure 1 shows lineated valley fill in one of a series of enclosed, intersecting troughs known as Coloe (Choloe) Fossae. Lineated valley fill consists of rows of material in valley centers that are parallel to the valley walls. It is probably made of ice-rich material and boulders that are left behind when the ice-rich material sublimates. Very distinct rows can be seen near the south (bottom) wall of the valley. Lineated valley fill is thought to result from mass wasting (downslope movement) of ice-rich material from valley walls towards their centers. It is commonly found in valleys near the crustal dichotomy that separates the two hemispheres of Mars. The valley shown here joins four other valleys with lineated fill near the top left corner of this image. Their juncture is a topographic low, suggesting that the lineated valley fill from the different valleys may be flowing or creeping towards the low area (movement towards the upper left of the image). The valley walls appear smooth at first glance but are seen to be speckled with small craters several meters in diameter at HiRISE resolution (see contrast-enhanced subimage). This indicates that at least some of the wall material has been stable to mass wasting for some period of time. Also seen on the valley wall are elongated features shaped like teardrops. These are most likely slightly older craters that have been degraded due to potentially recent downhill creep. It is unknown whether the valley walls are shedding material today. The subimage is approximately 140 x 400 m (450 x 1280 ft).

    Image PSP_001372_2160 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on November 11, 2006. The complete image is centered at 35.5 degrees latitude, 56.8 degrees East longitude. The range to the target site was 290.3 km (181

  18. Victor Valley College Agreement between the Victor Valley Community College District and the Victor Valley College California Teachers Association Chapter 1170. July 1989 - June 1992.

    ERIC Educational Resources Information Center

    Victor Valley Community Coll. District, Victorville, CA.

    The collective bargaining agreement between the Victor Valley College Board of Trustees and the Victor Valley College California Teachers Association/National Education Association is presented. This contract, covering the period from July 1989 through June 1992, deals with the following topics: bargaining agent recognition; district and…

  19. Valley spin polarization of Tl/Si(111)

    NASA Astrophysics Data System (ADS)

    Stolwijk, Sebastian D.; Schmidt, Anke B.; Sakamoto, Kazuyuki; Krüger, Peter; Donath, Markus

    2017-11-01

    The metal/semiconductor hybrid system Tl/Si(111)-(1 ×1 ) exhibits a unique Tl-derived surface state with remarkable properties. It lies within the silicon band gap and forms spin-momentum-locked valleys close to the Fermi energy at the K ¯ and K¯' points. These valleys are completely spin polarized with opposite spin orientation at K ¯ and K¯' and show a giant spin splitting of more than 0.5 eV. We present a detailed preparation study of the surface system and demonstrate that the electronic valleys are extremely robust, surviving exposure to 100 L hydrogen and 500 L oxygen. We investigate the influence of additional Tl atoms on the spin-polarized valleys. By combining photoemission and inverse photoemission, we prove the existence of fully spin-polarized valleys crossing the Fermi level. Moreover, these metallic valleys carry opposite Berry curvature at K ¯ and K¯', very similar to WSe2, promising a large spin Hall effect. Thus, Tl/Si(111)-(1 ×1 ) possesses all necessary key properties for spintronic applications.

  20. Electrical valley filtering in transition metal dichalcogenides

    NASA Astrophysics Data System (ADS)

    Hsieh, Tzu-Chi; Chou, Mei-Yin; Wu, Yu-Shu

    2018-03-01

    This work investigates the feasibility of electrical valley filtering for holes in transition metal dichalcogenides. We look specifically into the scheme that utilizes a potential barrier to produce valley-dependent tunneling rates, and perform the study with both a k .p -based analytic method and a recursive Green's function-based numerical method. The study yields the transmission coefficient as a function of incident energy and transverse wave vector, for holes going through lateral quantum barriers oriented in either armchair or zigzag directions, in both homogeneous and heterogeneous systems. The main findings are the following: (1) The tunneling current valley polarization increases with increasing barrier width or height; (2) both the valley-orbit interaction and band structure warping contribute to valley-dependent tunneling, with the former contribution being manifest in structures with asymmetric potential barriers, and the latter being orientation dependent and reaching maximum for transmission in the armchair direction; and (3) for transmission ˜0.1 , a tunneling current valley polarization of the order of 10 % can be achieved.

  1. Observation of valley-dependent beams in photonic graphene.

    PubMed

    Deng, Fusheng; Sun, Yong; Wang, Xiao; Xue, Rui; Li, Yuan; Jiang, Haitao; Shi, Yunlong; Chang, Kai; Chen, Hong

    2014-09-22

    Valley-dependent propagation of light in an artificial photonic hexagonal lattice, akin to electrons in graphene, is investigated in microwave regime. Both numerical and experimental results show that the valley degeneracy in the photonic graphene is broken when the frequency is away from the Dirac point. The peculiar anisotropic wave transport property due to distinct valleys is analyzed using the equifrequency contours. More interestingly, the valley-dependent self-collimation and beam splitting phenomena are experimentally demonstrated with the armchair and zigzag interfaces, respectively. Our results confirm that there are two inequivalent Dirac points that lead to two distinct valleys in photonic graphene, which could be used to control the flow of light and might be used to carry information in valley polarized beam splitter, collimator or guiding device.

  2. 27 CFR 9.58 - Carmel Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ....” (b) Approved maps. The approved maps for determining the boundary of the Carmel Valley viticultural... Ridge, Calif., dated 1956; and (5) Rana Creek, Calif., dated 1956. (c) Boundary. The Carmel Valley...

  3. 27 CFR 9.58 - Carmel Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....” (b) Approved maps. The approved maps for determining the boundary of the Carmel Valley viticultural... Ridge, Calif., dated 1956; and (5) Rana Creek, Calif., dated 1956. (c) Boundary. The Carmel Valley...

  4. Water resources of Parowan Valley, Iron County, Utah

    USGS Publications Warehouse

    Marston, Thomas M.

    2017-08-29

    Parowan Valley, in Iron County, Utah, covers about 160 square miles west of the Red Cliffs and includes the towns of Parowan, Paragonah, and Summit. The valley is a structural depression formed by northwest-trending faults and is, essentially, a closed surface-water basin although a small part of the valley at the southwestern end drains into the adjacent Cedar Valley. Groundwater occurs in and has been developed mainly from the unconsolidated basin-fill aquifer. Long-term downward trends in groundwater levels have been documented by the U.S. Geological Survey (USGS) since the mid-1950s. The water resources of Parowan Valley were assessed during 2012 to 2014 with an emphasis on refining the understanding of the groundwater and surface-water systems and updating the groundwater budget.Surface-water discharge of five perennial mountain streams that enter Parowan Valley was measured from 2013 to 2014. The total annual surface-water discharge of the five streams during 2013 to 2014 was about 18,000 acre-feet (acre-ft) compared to the average annual streamflow of about 22,000 acre-ft from USGS streamgages operated on the three largest of these streams from the 1940s to the 1980s. The largest stream, Parowan Creek, contributes more than 50 percent of the annual surface-water discharge to the valley, with smaller amounts contributed by Red, Summit, Little, and Cottonwood Creeks.Average annual recharge to the Parowan Valley groundwater system was estimated to be about 25,000 acre-ft from 1994 to 2013. Nearly all recharge occurs as direct infiltration of snowmelt and rainfall on the Markagunt Plateau east of the valley. Smaller amounts of recharge occur as infiltration of streamflow and unconsumed irrigation water near the east side of the valley on alluvial fans associated with mountain streams at the foot of the Red Cliffs. Subsurface flow from the mountain block to the east of the valley is a significant source of groundwater recharge to the basin-fill aquifer

  5. Optical manipulation of valley pseduospin in 2D semiconductors

    NASA Astrophysics Data System (ADS)

    Ye, Ziliang

    Valley polarization associated with the occupancy in the energy degenerate but quantum mechanically distinct valleys in the momentum space closely resembles spin polarization and has been proposed as a pseudospin carrier for future quantum information technologies. Monolayers of transition metal dichalcogenide (TMDC) crystals, with broken inversion symmetry and large spin-orbital coupling, support robust valley polarization and therefore provide an important platform for studying valley-dependent physics. Besides optical excitation and photoluminescence detection, valley polarization has been electrically measured through the valley Hall effect and created through spin injection from ferromagnetic semiconductor contacts. Moreover, the energy degeneracy of the valley degree of freedom has been lifted by the optical Stark effect. Recently, we have demonstrated optical manipulation of valley coherence, i.e., of the valley pseudospin, by the optical Stark effect in monolayer WSe2. Using below-bandgap circularly polarized light, we rotated the valley pseudospin on the femtosecond time scale. Both the direction and speed of the rotation can be optically controlled by tuning the dynamic phase of excitons in opposite valleys. The pseudospin rotation was identified by changes in the polarization of the photoluminescence. In addition, by varying the time delay between the excitation and control pulses, we directly probed the lifetime of the intervalley coherence. Similar rotation levels have also been observed in static magneto-optic experiments. Our work presents an important step towards the full control of the valley degree of freedom in 2D semiconductors. The work was done in collaboration with Dr. Dezheng Sun and Prof. Tony F. Heinz.

  6. Origin of the Valley Networks On Mars: A Hydrological Perspective

    NASA Technical Reports Server (NTRS)

    Gulick, Virginia C.

    2000-01-01

    The geomorphology of the Martian valley networks is examined from a hydrological perspective for their compatibility with an origin by rainfall, globally higher heat flow, and localized hydrothermal systems. Comparison of morphology and spatial distribution of valleys on geologic surfaces with terrestrial fluvial valleys suggests that most Martian valleys are probably not indicative of a rainfall origin, nor are they indicative of formation by an early global uniformly higher heat flow. In general, valleys are not uniformly distributed within geologic surface units as are terrestrial fluvial valleys. Valleys tend to form either as isolated systems or in clusters on a geologic surface unit leaving large expanses of the unit virtually untouched by erosion. With the exception of fluvial valleys on some volcanoes, most Martian valleys exhibit a sapping morphology and do not appear to have formed along with those that exhibit a runoff morphology. In contrast, terrestrial sapping valleys form from and along with runoff valleys. The isolated or clustered distribution of valleys suggests localized water sources were important in drainage development. Persistent ground-water outflow driven by localized, but vigorous hydrothermal circulation associated with magmatism, volcanism, impacts, or tectonism is, however, consistent with valley morphology and distribution. Snowfall from sublimating ice-covered lakes or seas may have provided an atmospheric water source for the formation of some valleys in regions where the surface is easily eroded and where localized geothermal/hydrothermal activity is sufficient to melt accumulated snowpacks.

  7. EPA Region 1 - Valley Depth in Meters

    EPA Pesticide Factsheets

    Raster of the Depth in meters of EPA-delimited Valleys in Region 1.Valleys (areas that are lower than their neighbors) were extracted from a Digital Elevation Model (USGS, 30m) by finding the local average elevation, subtracting the actual elevation from the average, and selecting areas where the actual elevation was below the average. The landscape was sampled at seven scales (circles of 1, 2, 4, 7, 11, 16, and 22 km radius) to take into account the diversity of valley shapes and sizes. Areas selected in at least four scales were designated as valleys.

  8. Preliminary hydrogeologic assessment near the boundary of the Antelope Valley and El Mirage Valley groundwater basins, California

    USGS Publications Warehouse

    Stamos, Christina L.; Christensen, Allen H.; Langenheim, Victoria

    2017-07-19

    The increasing demands on groundwater for water supply in desert areas in California and the western United States have resulted in the need to better understand groundwater sources, availability, and sustainability. This is true for a 650-square-mile area that encompasses the Antelope Valley, El Mirage Valley, and Upper Mojave River Valley groundwater basins, about 50 miles northeast of Los Angeles, California, in the western part of the Mojave Desert. These basins have been adjudicated to ensure that groundwater rights are allocated according to legal judgments. In an effort to assess if the boundary between the Antelope Valley and El Mirage Valley groundwater basins could be better defined, the U.S. Geological Survey began a cooperative study in 2014 with the Mojave Water Agency to better understand the hydrogeology in the area and investigate potential controls on groundwater flow and availability, including basement topography.Recharge is sporadic and primarily from small ephemeral washes and streams that originate in the San Gabriel Mountains to the south; estimates range from about 400 to 1,940 acre-feet per year. Lateral underflow from adjacent basins has been considered minor in previous studies; underflow from the Antelope Valley to the El Mirage Valley groundwater basin has been estimated to be between 100 and 1,900 acre-feet per year. Groundwater discharge is primarily from pumping, mostly by municipal supply wells. Between October 2013 and September 2014, the municipal pumpage in the Antelope Valley and El Mirage Valley groundwater basins was reported to be about 800 and 2,080 acre-feet, respectively.This study was motivated by the results from a previously completed regional gravity study, which suggested a northeast-trending subsurface basement ridge and saddle approximately 3.5 miles west of the boundary between the Antelope Valley and El Mirage Valley groundwater basins that might influence groundwater flow. To better define potential basement

  9. 78 FR 49972 - Importation of Cape Gooseberry From Colombia Into the United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-16

    ... (Physalis peruviana) from Colombia is authorized for importation into the United States if the commodity is... added to read as follows: Sec. 319.56-60 Cape gooseberry from Colombia. Cape gooseberry (Physalis peruviana) may be imported into the United States from Colombia in accordance with the conditions described...

  10. [Reference values for erythrocyte cholinesterase activity in the working population of Antioquia, Colombia, according to the Michel and EQM techniques].

    PubMed

    Carmona-Fonseca, Jaime

    2003-11-01

    To establish reference values for erythrocyte cholinesterase (EC 3.1.1.7) activity for the active working population of two regions of the department of Antioquia, Colombia, that are located at different altitudes above sea level. We took representative samples from populations of active working persons 18 to 59 years old from two regions in the department of Antioquia: (1) the Aburrá Valley (1 540 m above sea level) and (2) the near east of the department (2 150 m above sea level). We excluded workers who were using cholinesterase-inhibiting substances in their work or at home, those who had a disease that altered their cholinesterase levels, and those who said they were not in good health. We measured the erythrocyte cholinesterase activity using two methods: (1) the Michel method and (2) the EQM method (EQM Research, Cincinnati, Ohio, United States of America). We carried out the measurements with 827 people, 415 from the Aburrá Valley and 412 from the near east region. We compared proportions using the chi-square test and Fisher's exact test. We utilized the Student's t test for independent samples to compare two averages. To simultaneously compare three or more averages, analysis of variance was used, followed by the Newman-Keuls multiple-range test. When the variables were not normally distributed or when the variances were not homogeneous, Kruskal-Wallis nonparametric analysis of variance was used to compare the medians. Three computer software programs were used in the statistical analysis: SPSS 9.0, SGPlus 7.1, and Epi Info 6.04. In all the statistical tests the level of significance was set at P < 0.05. The average erythrocyte cholinesterase activity value that we found for the studied population by using the Michel method was 0.857 delta pH/hour (95% confidence interval (CI): 0.849 to 0.866), and the average value found through the EQM method was 35.21 U/g hemoglobin (95% CI: 34.82 to 35.60). With the Michel method: (1) the enzymatic activity differed

  11. Control of Exciton Valley Coherence in Transition Metal Dichalcogenide Monolayers

    NASA Astrophysics Data System (ADS)

    Wang, Gang

    Current research on Transition Metal Dichalcogenide (TMD) Monolayers is stimulated by their strong light-matter interaction and the possibility to use the valley index in addition to spin as an information carrier. The direct gap interband transitions in TMD monolayers are governed by chiral optical selection rules. Determined by laser helicity, optical transitions in either the K+ or K- valley in momentum space are induced. Very recently the optical generation of valley polarization and valley coherence (coherent superposition of valley states) have been reported. In this work we go a step further by discussing the coherent manipulation of valley states. Linearly polarized laser excitation prepares a coherent superposition of valley states. We demonstrate the control of the exciton valley coherence in monolayer WSe2 by tuning the applied magnetic field perpendicular to the monolayer plane. The induced valley Zeeman splitting between K+ and K- results in a change of the oscillation frequency of the superposition of the valley states, which corresponds to a rotation of the exciton valley pseudo-spin. We show rotation of this coherent superposition of valley states by angles as large as 30 degrees in applied fields up to 9T and discuss valley coherence in other TMD monolayer materials. This exciton valley coherence control on ps time scale could be an important step towards complete control of qubits based on the valley degree of freedom. In collaboration with X. Marie, T. Amand, C. Robert, F. Cadiz, P. Renucci, B. Urbaszek (Université de Toulouse, INSA-CNRS-UPS, LPCNO, France), B. L. Liu (Institute of Physics, Chinese Academy of Sciences, China) and we acknowledge ERC Grant No. 306719.

  12. Geology and water resources of Owens Valley, California

    USGS Publications Warehouse

    Hollett, Kenneth J.; Danskin, Wesley R.; McCaffrey, William F.; Walti, Caryl L.

    1991-01-01

    Owens Valley, a long, narrow valley located along the east flank of the Sierra Nevada in east-central California, is the main source of water for the city of Los Angeles. The city diverts most of the surface water in the valley into the Owens River-Los Angeles Aqueduct system, which transports the water more than 200 miles south to areas of distribution and use. Additionally, ground water is pumped or flows from wells to supplement the surface-water diversions to the river-aqueduct system. Pumpage from wells needed to supplement water export has increased since 1970, when a second aqueduct was put into service, and local concerns have been expressed that the increased pumpage may have had a detrimental effect on the environment and the indigenous alkaline scrub and meadow plant communities in the valley. The scrub and meadow communities depend on soil moisture derived from precipitation and the unconfined part of a multilayered aquifer system. This report, which describes the hydrogeology of the aquifer system and the water resources of the valley, is one in a series designed to (1) evaluate the effects that groundwater pumping has on scrub and meadow communities and (2) appraise alternative strategies to mitigate any adverse effects caused by, pumping. Two principal topographic features are the surface expression of the geologic framework--the high, prominent mountains on the east and west sides of the valley and the long, narrow intermountain valley floor. The mountains are composed of sedimentary, granitic, and metamorphic rocks, mantled in part by volcanic rocks as well as by glacial, talus, and fluvial deposits. The valley floor is underlain by valley fill that consists of unconsolidated to moderately consolidated alluvial fan, transition-zone, glacial and talus, and fluvial and lacustrine deposits. The valley fill also includes interlayered recent volcanic flows and pyroclastic rocks. The bedrock surface beneath the valley fill is a narrow, steep-sided graben

  13. Geohydrology of the Unconsolidated Valley-Fill Aquifer in the Meads Creek Valley, Schuyler and Steuben Counties, New York

    USGS Publications Warehouse

    Miller, Todd S.; Bugliosi, Edward F.; Reddy, James E.

    2008-01-01

    The Meads Creek valley encompasses 70 square miles of predominantly forested uplands in the upper Susquehanna River drainage basin. The valley, which was listed as a Priority Waterbody by the New York State Department of Environmental Conservation in 2004, is prone to periodic flooding, mostly in its downstream end, where development is occurring most rapidly. Hydraulic characteristics of the unconsolidated valley-fill aquifer were evaluated, and seepage rates in losing and gaining tributaries were calculated or estimated, in an effort to delineate the aquifer geometry and identify the factors that contribute to flooding. Results indicated that (1) Meads Creek gained about 61 cubic feet of flow per second (about 6.0 cubic feet per second per mile of stream channel) from ground-water discharge and inflow from tributaries in its 10.2-mile reach between the northernmost and southernmost measurement sites; (2) major tributaries in the northern part of the valley are not significant sources of recharge to the aquifer; and (3) major tributaries in the central and southern part of the valley provide recharge to the aquifer. The ground-water portion of streamflow in Meads Creek (excluding tributary inflow) was 11.3 cubic feet per second (ft3/s) in the central part of the valley and 17.2 ft3/s in the southern part - a total of 28.5 ft3/s. Ground-water levels were measured in 29 wells finished in unconfined deposits for construction of a potentiometric-surface map to depict directions of ground-water flow within the valley. In general, ground water flows from the edges of the valley toward Meads Creek and ultimately discharges to it. The horizontal hydraulic gradient for the entire 12-mile-long aquifer averages about 30 feet per mile, whereas the gradient in the southern fourth of the valley averages about half that - about 17 feet per mile. A water budget for the aquifer indicated that 28 percent of recharge was derived from precipitation that falls on the aquifer, 32

  14. [Mortality by homicides in Colombia, 1998-2012].

    PubMed

    Chaparro-Narváez, Pablo; Cotes-Cantillo, Karol; León-Quevedo, Willian; Castañeda-Orjuela, Carlos

    2016-12-01

    Homicide is a universal indicator of social violence with large public health consequences. To describe mortality by homicides and to analyze its trends and geographic distribution in Colombia between 1998 and 2012. We conducted a descriptive study of deaths by homicide in Colombia between 1998 and 2012 using official mortality databases and the population projections of the Departamento Administrativo Nacional de Estadística, DANE. We calculated age- and sex-specific mortality rates, and we analyzed the geographical distribution of mean-adjusted homicide mortality rates at municipal level. Between 1998 and 2012, 331,470 homicides were reported in Colombia. The mean crude rate was 51.5 per 100,000 inhabitants: 95.9 in men and 8.2 in women. Since 2003, a decrease in the number of deaths and rates was observed; 91.9% of the victims were men and the highest mortality rates were reported in the 20-29 years old group. The most frequently involved mechanism was the firearm: Eight of 10 homicides in men, and seven of 10 homicides in women. Out of 1,122 municipalities, 186 were in the highest quintile, accumulating 50.1% of all deaths. In Colombia, homicides have been one of the leading causes of death with a trend towards reduction since 2002. Its geographical distribution has been heterogeneous. To continue addressing this public health issue we must recur to multidisciplinary analytical methodologies for a better understanding of the phenomenon.

  15. Observation of valley-selective microwave transport in photonic crystals

    NASA Astrophysics Data System (ADS)

    Ye, Liping; Yang, Yuting; Hong Hang, Zhi; Qiu, Chunyin; Liu, Zhengyou

    2017-12-01

    Recently, the discrete valley degree of freedom has attracted extensive attention in condensed matter physics. Here, we present an experimental observation of the intriguing valley transport for microwaves in photonic crystals, including the bulk valley transport and the valley-projected edge modes along the interface separating different photonic insulating phases. For both cases, valley-selective excitations are realized by a point-like chiral source located at proper locations inside the samples. Our results are promising for exploring unprecedented routes to manipulate microwaves.

  16. California's Central Valley Groundwater Study: A Powerful New Tool to Assess Water Resources in California's Central Valley

    USGS Publications Warehouse

    Faunt, Claudia C.; Hanson, Randall T.; Belitz, Kenneth; Rogers, Laurel

    2009-01-01

    Competition for water resources is growing throughout California, particularly in the Central Valley. Since 1980, the Central Valley's population has nearly doubled to 3.8 million people. It is expected to increase to 6 million by 2020. Statewide population growth, anticipated reductions in Colorado River water deliveries, drought, and the ecological crisis in the Sacramento-San Joaquin Delta have created an intense demand for water. Tools and information can be used to help manage the Central Valley aquifer system, an important State and national resource.

  17. 27 CFR 9.90 - Willamette Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) “Roseburg,” Location Diagram NL 10-2, 1958 (revised 1970). (c) Boundaries. The Willamette Valley... valleys of Little River, Mosby Creek, Sharps Creek and Lost Creek to the intersection of R1W/R1E and State...

  18. Valley photonic crystals for control of spin and topology

    NASA Astrophysics Data System (ADS)

    Dong, Jian-Wen; Chen, Xiao-Dong; Zhu, Hanyu; Wang, Yuan; Zhang, Xiang

    2017-03-01

    Photonic crystals offer unprecedented opportunity for light manipulation and applications in optical communication and sensing. Exploration of topology in photonic crystals and metamaterials with non-zero gauge field has inspired a number of intriguing optical phenomena such as one-way transport and Weyl points. Recently, a new degree of freedom, valley, has been demonstrated in two-dimensional materials. Here, we propose a concept of valley photonic crystals with electromagnetic duality symmetry but broken inversion symmetry. We observe photonic valley Hall effect originating from valley-dependent spin-split bulk bands, even in topologically trivial photonic crystals. Valley-spin locking behaviour results in selective net spin flow inside bulk valley photonic crystals. We also show the independent control of valley and topology in a single system that has been long pursued in electronic systems, resulting in topologically-protected flat edge states. Valley photonic crystals not only offer a route towards the observation of non-trivial states, but also open the way for device applications in integrated photonics and information processing using spin-dependent transportation.

  19. A review of empirical evidence on different uncanny valley hypotheses: support for perceptual mismatch as one road to the valley of eeriness

    PubMed Central

    Kätsyri, Jari; Förger, Klaus; Mäkäräinen, Meeri; Takala, Tapio

    2015-01-01

    The uncanny valley hypothesis, proposed already in the 1970s, suggests that almost but not fully humanlike artificial characters will trigger a profound sense of unease. This hypothesis has become widely acknowledged both in the popular media and scientific research. Surprisingly, empirical evidence for the hypothesis has remained inconsistent. In the present article, we reinterpret the original uncanny valley hypothesis and review empirical evidence for different theoretically motivated uncanny valley hypotheses. The uncanny valley could be understood as the naïve claim that any kind of human-likeness manipulation will lead to experienced negative affinity at close-to-realistic levels. More recent hypotheses have suggested that the uncanny valley would be caused by artificial–human categorization difficulty or by a perceptual mismatch between artificial and human features. Original formulation also suggested that movement would modulate the uncanny valley. The reviewed empirical literature failed to provide consistent support for the naïve uncanny valley hypothesis or the modulatory effects of movement. Results on the categorization difficulty hypothesis were still too scarce to allow drawing firm conclusions. In contrast, good support was found for the perceptual mismatch hypothesis. Taken together, the present review findings suggest that the uncanny valley exists only under specific conditions. More research is still needed to pinpoint the exact conditions under which the uncanny valley phenomenon manifests itself. PMID:25914661

  20. Gravity survey of Dixie Valley, west-central Nevada

    USGS Publications Warehouse

    Schaefer, Donald H.

    1983-01-01

    Dixie Valley, a northeast-trending structural trough typical of valleys in the Basin and Range Province, is filled with a maximum of about 10,000 feet of alluvial and lacustrine deposits , as estimated from residual-gravity measurements obtained in this study. On the basis of gravity measurements at 300 stations on nine east-west profiles, the gravity residuals reach a maximum of 30 milligals near the south-central part of the valley. Results from a three-dimensional inversion model indicate that the central depression of the valley is offset to the west of the geographic axis. This offset is probably due to major faulting along the west side of the valley adjacent to the Stillwater Range. Comparison of depths to bedrock obtained during this study and depths obtained from a previous seismic-refraction study indicates a reasonably good correlation. A heterogeneous distribution of densities within the valley-fill deposits would account for differing depths determined by the two methods. (USGS)

  1. The Great Tumaco, Colombia earthquake of 12 December 1979

    USGS Publications Warehouse

    Herd, D.G.; Youd, T.L.; Meyer, H.; Arango, C.J.L.; Person, W.J.; Mendoza, C.

    1981-01-01

    Southwestern Colombia and northern Ecuador were shaken by a shallow-focus earthquake on 12 December 1979. The magnitude 8 shock, located near Tumaco, Colombia, was the largest in northwestern South America since 1942 and had been forecast to fill a seismic gap. Thrust faulting occurred on a 280- by 130-kilometer rectangular patch of a subduction zone that dips east beneath the Pacific coast of Colombia. A 200-kilometer stretch of the coast tectonically subsided as much as 1.6 meters; uplift occurred offshore on the continental slope. A tsunami swept inland immediately after the earthquake. Ground shaking (intensity VI to IX) caused many buildings to collapse and generated liquefaction in sand fills and in Holocene beach, lagoonal, and fluvial deposits.

  2. Napa Valley Community College District and Napa Valley College Faculty Association/CTA/NEA 1988-89 Agreement.

    ERIC Educational Resources Information Center

    Napa Valley Community Coll. District, Napa, CA.

    The collective bargaining agreement between the Board of Trustees of the Napa Valley Community College District and the Napa Valley College Faculty Association/California Teachers Association/National Education Association is presented. This contract, in effect from June 1988 through July 1989, deals with the following topics: bargaining agent…

  3. Channels and valleys on Mars

    NASA Technical Reports Server (NTRS)

    Baker, V. R.

    1983-01-01

    Tentative conclusions about the origins of channels and valleys on Mars based on the consensus of investigators who have studied the problem are presented. The morphology of outflow channels is described in detail, and the morphology, distribution, and genesis of Martian valleys are addressed. Secondary modification of channels and valleys by mass-wasting phenomena, eolian processes, cratering, and mantling by lava flows is discussed. The physics of the flows needed to account for the immense volumes of Martian outflow channels is considered in detail, including the possible influence of debris flows and mudflows, glaciers, and ice sheets. It is concluded that Mars once probably possessed an atmosphere with higher temperatures and pressures than at present which played an essential role in an active hydrological cycle.

  4. The geochemistry of groundwater resources in the Jordan Valley: The impact of the Rift Valley brines

    USGS Publications Warehouse

    Farber, E.; Vengosh, A.; Gavrieli, I.; Marie, Amarisa; Bullen, T.D.; Mayer, B.; Polak, A.; Shavit, U.

    2007-01-01

    The chemical composition of groundwater in the Jordan Valley, along the section between the Sea of Galilee and the Dead Sea, is investigated in order to evaluate the origin of the groundwater resources and, in particular, to elucidate the role of deep brines on the chemical composition of the regional groundwater resources in the Jordan Valley. Samples were collected from shallow groundwater in research boreholes on two sites in the northern and southern parts of the Jordan Valley, adjacent to the Jordan River. Data is also compiled from previous published studies. Geochemical data (e.g., Br/Cl, Na/Cl and SO4/Cl ratios) and B, O, Sr and S isotopic compositions are used to define groundwater groups, to map their distribution in the Jordan valley, and to evaluate their origin. The combined geochemical tools enabled the delineation of three major sources of solutes that differentially affect the quality of groundwater in the Jordan Valley: (1) flow and mixing with hypersaline brines with high Br/Cl (>2 ?? 10-3) and low Na/Cl (<0.8) ratios; (2) dissolution of highly soluble salts (e.g., halite, gypsum) in the host sediments resulting in typically lower Br/Cl signal (<2 ?? 10-3); and (3) recharge of anthropogenic effluents, primarily derived from evaporated agricultural return flow that has interacted (e.g., base-exchange reactions) with the overlying soil. It is shown that shallow saline groundwaters influenced by brine mixing exhibit a north-south variation in their Br/Cl and Na/Cl ratios. This chemical trend was observed also in hypersaline brines in the Jordan valley, which suggests a local mixing process between the water bodies. ?? 2007 Elsevier Ltd. All rights reserved.

  5. 36 CFR 7.26 - Death Valley National Monument.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Death Valley National... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.26 Death Valley National Monument. (a) Mining. Mining in Death Valley National Monument is subject to the following regulations, which are...

  6. Mineral resources of Colombia (other than petroleum)

    USGS Publications Warehouse

    Singewald, Quentin Dreyer

    1950-01-01

    The following report summarizes data acquired during 1942-45, in Colombia, by geologists and engineers of the Foreign Economic Administration, with whom the United States Geological Survey cooperated. Twenty-nine mineral commodities are considered, but the data for five of them are scant because they were of no interest to FEA personnel. Petroleum is not considered. Preliminary to a review of individual mineral commodities, resumes are given of the general geography and geology of Colombia and of the country's mining laws. The principal mineral commodities, besides petroleum, produced in Colombia are (1) emeralds, gold, platinum, and silver, mainly for export, and (2) barite, cement, clay, coal, gypsum, salt, sand and gravel, silica, and stone, mainly for the domestic market. A large number of other mineral commodities are known in "raw" prospects, some of which may eventually become productive. Their distribution and apparent potentialities, as of 1945, are given. Factors unfavorable to mining are the ruggedness of the terrain, the scarcity of outcrops, and the very high transportation costs.

  7. Total carbon and nitrogen in mineral soil after 26 years of prescribed fire: Long Valley and Fort Valley Experimental Forests

    Treesearch

    Daniel G. Neary; Sally M. Haase; Steven T. Overby

    2008-01-01

    Prescribed fire was introduced to high density ponderosa pine stands at Fort Valley and Long Valley Experimental Forests in 1976. This paper reports on mineral soil total carbon (C) and nitrogen (N) at Long Valley. Total soil C and N levels were highly variable and exhibited an increasing, but inconsistent, concentration trend related to burn interval. Total N ranged...

  8. Valley-polarized quantum transport generated by gauge fields in graphene

    NASA Astrophysics Data System (ADS)

    Settnes, Mikkel; Garcia, Jose H.; Roche, Stephan

    2017-09-01

    We report on the possibility to simultaneously generate in graphene a bulk valley-polarized dissipative transport and a quantum valley Hall effect by combining strain-induced gauge fields and real magnetic fields. Such unique phenomenon results from a ‘resonance/anti-resonance’ effect driven by the superposition/cancellation of superimposed gauge fields which differently affect time reversal symmetry. The onset of a valley-polarized Hall current concomitant to a dissipative valley-polarized current flow in the opposite valley is revealed by a {{e}2}/h Hall conductivity plateau. We employ efficient linear scaling Kubo transport methods combined with a valley projection scheme to access valley-dependent conductivities and show that the results are robust against disorder.

  9. Catalogue of Tephritidae of Colombia

    USDA-ARS?s Scientific Manuscript database

    The present Catalogue includes 93 species and 23 genera of Tephritidae that have been recorded in Colombia. Four subfamilies (Blepharoneurinae, Dacinae, Trypetinae and Tephritinae), and eight tribes (Acrotaeniini, Carpomyini, Dacini, Eutretini, Myopitini, Noeetini, Tephritini, and Toxotrypanini) are...

  10. Smokefree implementation in Colombia: Monitoring, outside funding, and business support.

    PubMed

    Uang, Randy; Crosbie, Eric; Glantz, Stanton A

    2017-01-01

    To analyze successful national smokefree policy implementation in Colombia, a middle income country. Key informants at the national and local levels were interviewed and news sources and government ministry resolutions were reviewed. Colombia's Ministry of Health coordinated local implementation practices, which were strongest in larger cities with supportive leadership. Nongovernmental organizations provided technical assistance and highlighted noncompliance. Organizations outside Colombia funded some of these efforts. The bar owners' association provided concerted education campaigns. Tobacco interests did not openly challenge implementation. Health organization monitoring, external funding, and hospitality industry support contributed to effective implementation, and could be cultivated in other low and middle income countries.

  11. Molecular characterization of Hepatozoon canis in dogs from Colombia.

    PubMed

    Vargas-Hernandez, Giovanni; André, Marcos R; Munhoz, Thiago D; Faria, Joice M L; Machado, Rosangela Z; Tinucci-Costa, Mirela

    2012-01-01

    Hepatozoonosis is a tick-borne disease whose transmission to dogs occurs by ingestion of oocysts infected ticks or feeding on preys infested by infected ticks. Until now, there is no previous report of molecular characterization of Hepatozoon sp. in dogs from Colombia. EDTA blood samples were collected from 91 dogs from central-western region of Colombia (Bogotá, Bucaramanga, and Villavicencio cities) and submitted to 18S rRNA Hepatozoon sp. PCR and blood smears confection. Phylogenetic analysis was used to access the identity of Hepatozoon species found in sampled dogs. From 91 sampled dogs, 29 (31.8%) were positive to Hepatozoon sp. (25 dogs were only positive in PCR, 1 was positive only in blood smears, and 3 were positive in both blood smears and PCR). After sequencing, the found Hepatozoon sp. DNA showed 100% of identity with Hepatozoon canis DNA isolates. The phylogenetic tree supported the identity of the found Hepatozoon sp. DNA, showing that the isolates from Colombia were placed in the same clade than other H. canis isolates from Venezuela, Spain, and Taiwan. This is the first molecular detection of H. canis in dogs from Colombia.

  12. Groundwater availability of the Central Valley Aquifer, California

    USGS Publications Warehouse

    Faunt, Claudia C.

    2009-01-01

    California's Central Valley covers about 20,000 square miles and is one of the most productive agricultural regions in the world. More than 250 different crops are grown in the Central Valley with an estimated value of $17 billion per year. This irrigated agriculture relies heavily on surface-water diversions and groundwater pumpage. Approximately one-sixth of the Nation's irrigated land is in the Central Valley, and about one-fifth of the Nation's groundwater demand is supplied from its aquifers. The Central Valley also is rapidly becoming an important area for California's expanding urban population. Since 1980, the population of the Central Valley has nearly doubled from 2 million to 3.8 million people. The Census Bureau projects that the Central Valley's population will increase to 6 million people by 2020. This surge in population has increased the competition for water resources within the Central Valley and statewide, which likely will be exacerbated by anticipated reductions in deliveries of Colorado River water to southern California. In response to this competition for water, a number of water-related issues have gained prominence: conservation of agricultural land, conjunctive use, artificial recharge, hydrologic implications of land-use change, and effects of climate variability. To provide information to stakeholders addressing these issues, the USGS Groundwater Resources Program made a detailed assessment of groundwater availability of the Central Valley aquifer system, that includes: (1) the present status of groundwater resources; (2) how these resources have changed over time; and (3) tools to assess system responses to stresses from future human uses and climate variability and change. This effort builds on previous investigations, such as the USGS Central Valley Regional Aquifer System and Analysis (CV-RASA) project and several other groundwater studies in the Valley completed by Federal, State and local agencies at differing scales. The

  13. Valley-selective optical Stark effect in monolayer WS2

    NASA Astrophysics Data System (ADS)

    Gedik, Nuh

    Monolayer semiconducting transition-metal dichalcogenides (TMDs) have a pair of valleys that, by time-reversal symmetry, are energetically degenerate. Lifting the valley degeneracy in these materials is of great interest because it would allow for valley specific band engineering and offer additional control in valleytronic applications. In this talk, I will show that circularly polarized light, which breaks time-reversal symmetry, can be used to lift the valley degeneracy by means of the optical Stark effect. We demonstrate that this effect is capable of raising the exciton level in monolayer TMD WS2 by as much as 18 meV in a controllable valley-selective manner. The resulting energy shift is extremely large, comparable to the shift that would be obtained using a very high magnetic field (approximately 100 Tesla). These results offer a novel way to control valley degree of freedom, and may provide a means to realize new valley-selective Floquet topological state of matter.

  14. Impacts of Climate Change on Colombia’s National and Regional Security

    DTIC Science & Technology

    2009-10-01

    Peru, and Chile have relatively diverse, industrialized economies and greater domestic resources and state capaci- ties for adaptation. Bolivia...Change on Colombia’s National and Regional Security References 1 Colombia, Sistema de Informacion sobre el Uso del Agua en la Agricultura y el Medio...Jul 2009. "El cambio climatico en Colombia." Unpublished report shared with authors. IDEAM. 26 "El agua para 40 millones de personas esta en riesgo

  15. Prediabetes in Colombia: Expert Consensus.

    PubMed

    López-Jaramillo, Patricio; Calderón, Carlos; Castillo, Jorge; Escobar, Iván Darío; Melgarejo, Enrique; Parra, Gustavo Adolfo

    2017-12-30

    The prevalence of Prediabetes in Colombia is high, and despite being recognized and categorized in the main Medical Guidelines and included in the International Classification of Diseases in Colombia, knowledge and awareness of it is limited amongst healthcare professionals and in the community. Our expert group recommends that educational programs emphasize a global approach to risk which includes a recognition of the importance of prediabetes and its evaluation along with and other risk factors such as a family history of DM2, overweight and obesity, dislipidemia and hypertension. Studies conducted in Colombia demonstrate the value of the FINDRIS questionnaire as a tool to identify subjects at risk of prediabetes and DM2, and we recommend that it should be systematic applied throughout the country as part of government policy. Prediabetes progresses to DM2 at an annual rate of 10%, but it has also been shown that prediabetes is an independent risk factor for cardiovascular outcomes. On this basis, the Committee recommends that once prediabetes is detected and diagnosed, immediate management of the disease begins through lifestyle changes, with follow up assessments performed at 3 and 6 months. If the patient does not respond with a weight loss of at least 5% and if the HbA1C values ​​are not normalized, pharmacological management should be initiated with a metformin dose of 500 mg / day, increasing up to 1,500 - 1,700 mg / day, according to tolerance.

  16. Prediabetes in Colombia: Expert Consensus

    PubMed Central

    Calderón, Carlos; Castillo, Jorge; Escobar, Iván Darío; Melgarejo, Enrique; Parra, Gustavo Adolfo

    2017-01-01

    Abstract The prevalence of Prediabetes in Colombia is high, and despite being recognized and categorized in the main Medical Guidelines and included in the International Classification of Diseases in Colombia, knowledge and awareness of it is limited amongst healthcare professionals and in the community. Our expert group recommends that educational programs emphasize a global approach to risk which includes a recognition of the importance of prediabetes and its evaluation along with and other risk factors such as a family history of DM2, overweight and obesity, dislipidemia and hypertension. Studies conducted in Colombia demonstrate the value of the FINDRIS questionnaire as a tool to identify subjects at risk of prediabetes and DM2, and we recommend that it should be systematic applied throughout the country as part of government policy. Prediabetes progresses to DM2 at an annual rate of 10%, but it has also been shown that prediabetes is an independent risk factor for cardiovascular outcomes. On this basis, the Committee recommends that once prediabetes is detected and diagnosed, immediate management of the disease begins through lifestyle changes, with follow up assessments performed at 3 and 6 months. If the patient does not respond with a weight loss of at least 5% and if the HbA1C values ​​are not normalized, pharmacological management should be initiated with a metformin dose of 500 mg / day, increasing up to 1,500 - 1,700 mg / day, according to tolerance. PMID:29662261

  17. Groundwater sapping valleys: Experimental studies, geological controls and implications to the interpretation of valley networks on Mars

    NASA Technical Reports Server (NTRS)

    Kochel, R. Craig

    1988-01-01

    An integrated approach using experimental laboratory models, field studies of terrestrial analogs, and remote studies of terrestrial field sites were applied to the goals of understanding the nature and morphology of valley networks formed by groundwater sapping. In spite of problems with scaling, the experimental studies provide valuable insights into concepts relating to the initiation, development, and evolution of valleys by groundwater sapping. These investigations are also aimed at developing geomorphic criteria for distinguishing valleys formed by surface runoff from those formed by groundwater sapping processes. Channels that were field classified as sapping vs. runoff were successfully distinguished using statistical analysis of their respective morphologies; therefore, it may be possible to use similar techniques to interpret channel genesis on Mars. The terrestrial and flume studies provide the ground truth dataset which can be used (and will be during the present year) to help interpret the genesis of valley networks on Mars.

  18. Dengue mortality in Colombia, 1985-2012.

    PubMed

    Chaparro-Narváez, Pablo; León-Quevedo, Willian; Castañeda-Orjuela, Carlos Andrés

    2016-02-11

    Dengue in Colombia is an important public health problem due to the huge economic and social costs it has caused, especially during the disease outbreaks.  To describe the behavior of dengue mortality in Colombia between 1985 and 2012.  We conducted a descriptive study. Information was obtained from mortality and population projection databases provided by the Departamento Administrativo Nacional de Estadística (DANE) for the 1985-2012 period. Mortality rates, rate ratios, and case fatality rates were estimated.  A total of 1,990 dengue deaths were registered during this period in Colombia. Dengue mortality rates presented an increasing trend with statistical significance between 1985 and 1998. Higher mortality rates were reported in men both younger than 5 years and older than 65 years. Between 1995 and 2012, category 1 to 4 municipalities reported the highest mortality rates. Case fatality rates varied during the period between 0.01% and 0.39%.  Dengue is an avoidable disease that should disappear from mortality statistics as a cause of death. The event is avoidable if the proposed activities from the Estrategia de Gestión Integrada (EGI)-Dengue are implemented and evaluated. We recommend encouraging the development of an informational culture to contribute to decision making and prioritizing resource allocation.

  19. [Cigarette taxes and demand in Colombia].

    PubMed

    Maldonado, Norman; Llorente, Blanca; Deaza, Javier

    2016-10-01

    Estimate price and income elasticities of aggregate demand for cigarettes in Colombia, by controlling for structural market changes since the late 1990s, to identify policy opportunities for taxes that could improve public health and increase tax revenues. Measurement of aggregate demand for cigarettes using gross income reported on value-added tax returns submitted to Colombia's National Tax and Customs Office (DIAN is the acronym in Spanish) by the tobacco product manufacturing industry, subtracting exports. A quarterly time series was obtained for the period 1994-2014. The econometric estimation using two-stage least squares controls for price endogeneity and uses a set of dummy variables to control for structural changes in the market and in its regulation. Demand is, from a statistical standpoint, sensitive to price and to income. Price elasticity of demand is -0.78 and income elasticity is 0.61. Inelastic demand implies that it is possible, through cigarette excise taxes, to meet public health targets and increase revenues simultaneously. The results also suggest that the considerable increase in household income in Colombia in the first decade of the 21st century increased purchasing power, which, lacking an accompanying tax increase, promoted cigarette consumption, with negative effects on public health, and wasted an opportunity to increase tax revenues.

  20. Hydrologic effects of stress-relief fracturing in an Appalachian Valley

    USGS Publications Warehouse

    Wyrick, Granville G.; Borchers, James W.

    1981-01-01

    A hydrologic study at Twin Falls State Park, Wyoming County, West Virginia, was made to determine how fracture systems affect the occurrence and movement of ground water in a typical valley of the Appalachian Plateaus Physiographic Province. Twin Falls was selected because it is generally unaffected by factors that would complicate an analysis of the data. The study area was the Black Fork Valley at Twin Falls. The valley is about 3 miles long and 400 to 600 feet wide and is cut into massive sandstone units interbedded with thin coal and shale beds. The study was made to determine how aquifer characteristics were related to fracture systems in this valley, so that the relation could be applied to studies of other valleys. Two sites were selected for test drilling, pumping tests, and geophysical studies. One site is in the upper part of the valley, and the second is near the lower central part. At both sites, ground water occurs mainly in horizontal bedding-plane fractures under the valley floor and in nearly vertical and horizontal slump fractures along the valley wall. The aquifer is under confined conditions under the valley floor and unconfined conditions along the valley wall. The fractures pinch out under the valley walls, which form impermeable barriers. Tests of wells near the valley center indicated a change in storage coefficient as the cone of depression caused by pumping reached the confined-unconfined boundaries; the tests also indicated barrier-image effects when the cone reached the impermeable boundaries. Drawdown from pumping near the center of the valley affected water levels at both sites, indicating a hydraulic connection from the upper to the lower end of the valley. Stream gain-and-loss studies show that ground water discharges to the stream from horizontal fractures beneath Black Fork Falls, near the mouth of Black Fork. The fracture systems that constitute most of the transmissive part of the aquifer at Twin Falls are like those described as

  1. Groundwater quality in the Santa Clara River Valley, California

    USGS Publications Warehouse

    Burton, Carmen A.; Landon, Matthew K.; Belitz, Kenneth

    2011-01-01

    The Santa Clara River Valley (SCRV) study unit is located in Los Angeles and Ventura Counties, California, and is bounded by the Santa Monica, San Gabriel, Topatopa, and Santa Ynez Mountains, and the Pacific Ocean. The 460-square-mile study unit includes eight groundwater basins: Ojai Valley, Upper Ojai Valley, Ventura River Valley, Santa Clara River Valley, Pleasant Valley, Arroyo Santa Rosa Valley, Las Posas Valley, and Simi Valley (California Department of Water Resources, 2003; Montrella and Belitz, 2009). The SCRV study unit has hot, dry summers and cool, moist winters. Average annual rainfall ranges from 12 to 28 inches. The study unit is drained by the Ventura and Santa Clara Rivers, and Calleguas Creek. The primary aquifer system in the Ventura River Valley, Ojai Valley, Upper Ojai Valley, and Simi Valley basins is largely unconfined alluvium. The primary aquifer system in the remaining groundwater basins mainly consists of unconfined sands and gravels in the upper portion and partially confined marine and nonmarine deposits in the lower portion. The primary aquifer system in the SCRV study unit is defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health (CDPH) database. Public-supply wells typically are completed in the primary aquifer system to depths of 200 to 1,100 feet below land surface (bls). The wells contain solid casing reaching from the land surface to a depth of about 60-700 feet, and are perforated below the solid casing to allow water into the well. Water quality in the primary aquifer system may differ from the water in the shallower and deeper parts of the aquifer. Land use in the study unit is approximately 40 percent (%) natural (primarily shrubs, grassland, and wetlands), 37% agricultural, and 23% urban. The primary crops are citrus, avocados, alfalfa, pasture, strawberries, and dry beans. The largest urban areas in the study unit are the cities of

  2. Outbreak of Rocky Mountain spotted fever in Córdoba, Colombia.

    PubMed

    Hidalgo, Marylin; Miranda, Jorge; Heredia, Damaris; Zambrano, Pilar; Vesga, Juan Fernando; Lizarazo, Diana; Mattar, Salim; Valbuena, Gustavo

    2011-02-01

    Rocky Mountain spotted fever (RMSF) is a tick-borne disease caused by the obligate intracellular bacterium Rickettsia rickettsii. Although RMSF was first reported in Colombia in 1937, it remains a neglected disease. Herein, we describe the investigation of a large cluster of cases of spotted fever rickettsiosis in a new area of Colombia.

  3. English Teaching Profile: Colombia.

    ERIC Educational Resources Information Center

    British Council, London (England). English Language and Literature Div.

    A review of the status of English language instruction in Colombia provides an overview of the role of English in the society in general and outlines the status of English use and instruction in the educational system at all levels (elementary, secondary, postsecondary, and teacher education). The following topics are covered: the characteristics…

  4. New records of spider wasps (Hymenoptera, Pompilidae) from Colombia

    PubMed Central

    Castro-Huertas, Valentina; Pitts, James P.; Rodriguez, Juanita; Cecilia Waichert; Fernández, Fernando

    2014-01-01

    Abstract New records of genera and species of spider wasps (Hymenoptera: Pompilidae) from Colombia are provided. Agenioideus, Cryptocheilus, Evagetes, Mystacagenia, and Xerochares are newly recorded genera from Colombia. Nineteen species are first recorded from Colombia: Aimatocare vitrea (Fox); Ageniella azteca (Cameron); Ageniella curtipinus (Cameron); Ageniella fallax (Arlé); Ageniella hirsuta Banks; Ageniella pilifrons (Cameron); Ageniella pretiosa Banks; Ageniella sanguinolenta (Smith); Ageniella zeteki (Banks); Agenioideus birkmanni (Banks); Aporus (Aporus) cuzco Evans; Aporus (Cosmiaporus) diverticulus (Fox); Aporus (Notoplaniceps) canescens Smith; Euplaniceps exilis (Banks); Euplaniceps herbertii (Fox); Irenangelus clarus Evans; Mystacagenia bellula Evans; Phanochilus nobilitatus (Smith) and Xerochares expulsus Schulz. The following species and genera have their occurence ranges expanded for South America: Ageniella azteca (Cameron); Ageniella zeteki (Banks); Agenioideus birkmanni (Banks); and Xerochares expulsus Schulz; Cryptocheilus Panzer; and Xerochares Evans. PMID:25349495

  5. California's restless giant: the Long Valley Caldera

    USGS Publications Warehouse

    Hill, David P.; Bailey, Roy A.; Hendley, James W.; Stauffer, Peter H.; Marcaida, Mae

    2014-01-01

    Scientists have monitored geologic unrest in the Long Valley, California, area since 1980. In that year, following a swarm of strong earthquakes, they discovered that the central part of the Long Valley Caldera had begun actively rising. Unrest in the area persists today. The U.S. Geological Survey (USGS) continues to provide the public and civil authorities with current information on the volcanic hazard at Long Valley and is prepared to give timely warnings of any impending eruption.

  6. Pumpernickel Valley Geothermal Project Thermal Gradient Wells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Z. Adam Szybinski

    2006-01-01

    The Pumpernickel Valley geothermal project area is located near the eastern edge of the Sonoma Range and is positioned within the structurally complex Winnemucca fold and thrust belt of north-central Nevada. A series of approximately north-northeast-striking faults related to the Basin and Range tectonics are superimposed on the earlier structures within the project area, and are responsible for the final overall geometry and distribution of the pre-existing structural features on the property. Two of these faults, the Pumpernickel Valley fault and Edna Mountain fault, are range-bounding and display numerous characteristics typical of strike-slip fault systems. These characteristics, when combined withmore » geophysical data from Shore (2005), indicate the presence of a pull-apart basin, formed within the releasing bend of the Pumpernickel Valley – Edna Mountain fault system. A substantial body of evidence exists, in the form of available geothermal, geological and geophysical information, to suggest that the property and the pull-apart basin host a structurally controlled, extensive geothermal field. The most evident manifestations of the geothermal activity in the valley are two areas with hot springs, seepages, and wet ground/vegetation anomalies near the Pumpernickel Valley fault, which indicate that the fault focuses the fluid up-flow. There has not been any geothermal production from the Pumpernickel Valley area, but it was the focus of a limited exploration effort by Magma Power Company. In 1974, the company drilled one exploration/temperature gradient borehole east of the Pumpernickel Valley fault and recorded a thermal gradient of 160oC/km. The 1982 temperature data from five unrelated mineral exploration holes to the north of the Magma well indicated geothermal gradients in a range from 66 to 249oC/km for wells west of the fault, and ~283oC/km in a well next to the fault. In 2005, Nevada Geothermal Power Company drilled four geothermal gradient wells

  7. Geology of the Greenwater Range, and the dawn of Death Valley, California—Field guide for the Death Valley Natural History Conference, 2013

    USGS Publications Warehouse

    Calzia, J.P.; Rämö, O.T.; Jachens, Robert; Smith, Eugene; Knott, Jeffrey

    2016-05-02

    Much has been written about the age and formation of Death Valley, but that is one—if not the last—chapter in the fascinating geologic history of this area. Igneous and sedimentary rocks in the Greenwater Range, one mountain range east of Death Valley, tell an earlier story that overlaps with the formation of Death Valley proper. This early story has been told by scientists who have studied these rocks for many years and continue to do so. This field guide was prepared for the first Death Valley Natural History Conference and provides an overview of the geology of the Greenwater Range and the early history (10–0 Ma) of Death Valley.

  8. 27 CFR 9.191 - Ramona Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Ramona Valley. 9.191 Section 9.191 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT...) Borrego Valley, California, 1982 edition; and (2) El Cajon, California, 1979 edition. (c) Boundary. The...

  9. 27 CFR 9.191 - Ramona Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ramona Valley. 9.191 Section 9.191 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT...) Borrego Valley, California, 1982 edition; and (2) El Cajon, California, 1979 edition. (c) Boundary. The...

  10. Environmental occurrence of arsenic in Colombia: a review.

    PubMed

    Alonso, David L; Latorre, Sergio; Castillo, Elianna; Brandão, Pedro F B

    2014-03-01

    The international literature on the presence of arsenic (As) in Latin America does not disclose the true magnitude of the presence of As in Colombia. In this paper, we summarize the literature on As occurrence in Colombia. The data reveal that As is present in matrices such as soil, sediments and water and in the food chain. Some of the As concentrations exceed the limits specified by national and international regulations. Arsenic higher concentrations are associated with mining regions (e.g., soils, up to 148 mg/kg; sediments, up to 1400 mg/kg) and agricultural areas (e.g., vegetables, up to 5.40 mg/kg; irrigation water, up to 255 μg/L), and underscore the potential human and environmental risks associated with the presence of As in the country. This review highlights the importance of focusing research on understanding the occurrence, origin and distribution of As in Colombia to better understand its environmental and public health impact. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. A Quantitative Analysis of the Fretted Terrain Valleys, Arabia Terra, Mars

    NASA Astrophysics Data System (ADS)

    Mason, Kelsey Anne

    Fretted terrain describes regions on Mars with low-lying, flat valleys separated by steep cliffs that often form polygonal-shaped mesas. The fretted terrain valleys have a morphology distinct from other valleys found on Mars, and their unknown origin may hold insights into critical questions about Mars' tectonic, magmatic, and hydrologic history. Current hypothesis for the formation of the fretted terrain include fracturing as well as hydrological flow processes such as fluvial or glacial erosion. The region for this study is located in eastern Arabia Terra and is the type-location for fretted terrain. By qualitatively and quantitatively documenting the planform, or map-view, valley geometries and orientations throughout the fretted terrain, this study better constrains the origin of the valleys. Valleys were mapped using automated routines in ArcGIS including the D8 flow direction algorithm. Valleys were then grouped geographically into basins and also by Strahler order. The valleys were then segmented every 50 km and the azimuth of each segment was calculated. The resulting valley azimuths were analyzed using rose diagrams to quantitatively describe the planform geometries of the valleys. Qualitatively, the majority of basins were found to have rectangular valley geometries. The downslope direction was calculated for each basin, and it was compared to the corresponding valley azimuths. The basins with rectangular valley geometries had valleys with an azimuth mode nearly parallel to the downslope direction and another azimuth mode perpendicular to the downslope direction. The valley azimuth mode parallel to the downslope direction is attributed to hydrological flow processes while the mode perpendicular to the downslope direction is attributed to fracturing related to the formation or existence of the Mars global dichotomy boundary.

  12. Ecology and policy for exclusive breastfeeding in Colombia: a proposal

    PubMed Central

    2012-01-01

    Introduction: Breastfeeding promotion is one of the most important strategies against infant mortality and to control child undernourishment. Despite policies and plans to promote and protect breastfeeding in Colombia, its practice is low and its duration is short. Objective: To propose an ecology framework to interpret and incorporate contextual, interpersonal, and individual factors associated with the practice of breastfeeding and duration. Thereby, the plans and policies addressed to promote and protect breastfeeding in Colombia could be reinforced. Conclusions: To implement an ecology framework for Breastfeeding in Colombia, it is necessary to identify the effect of contextual factors in the biggest cultural regions of Colombia, to recognize the limitations of Infant-Friendly Hospital Initiatives to improve exclusive breastfeeding duration, to execute prospective studies in order to identify factors associated with breastfeeding duration, to design and implement plans and policies based on comprehensive planning strategies of healthcare interventions, to develop appropriate and cost-effective extra-institutional strategies aimed at prolonging the duration of breastfeeding, and to implement more reliable breastfeeding surveillance systems. PMID:24893193

  13. Dynamics of valley pseudospin in single-layer WSe2. Inter-valley scattering mediated by electron-phonon interaction

    NASA Astrophysics Data System (ADS)

    Molina-Sanchez, Alejandro; Sangalli, Davide; Wirtz, Ludger; Marini, Andrea

    In a time-dependent Kerr experiment a circularly polarized laser field is used to selectively populate the K+/- electronic valleys of single-layer WSe2. This carrier population corresponds to a finite pseudospin polarization that dictates the valleytronic properties of WSe2, but whose decay mechanism still remains largely debated. Time-dependent Kerr experiments provide an accurate way to visualize the pseudospin dynamics by measuring the rotation of a linearly polarized probe pulse applied after a circularly polarized and short pump pulse. We present here a clear, accurate and parameter-free description of the valley pseudospin dynamics in single-layer WSe2. By using an ab-initio approach we solve unambiguously the long standing debate about the dominant mechanism that drives the valley depolarization. Our results are in excellent agreement with recent time-dependent Kerr experiments. The decay dynamics and peculiar temperature dependence is explained in terms of electron phonon mediated processes that induce spin-flip inter-valley transitions.

  14. Scaling relationships and concavity of small valley networks on Mars

    NASA Astrophysics Data System (ADS)

    Penido, Julita C.; Fassett, Caleb I.; Som, Sanjoy M.

    2013-01-01

    Valley networks are widely interpreted as the preserved erosional record of water flowing across the martian surface. The manner in which valley morphometric properties scale with drainage area has been widely examined on Earth. Earlier studies assessing these properties on Mars have suggested that martian valleys are morphometrically distinct from those on Earth. However, these earlier measurements were generally made on large valley systems because of the limited topographic data available. In this study, we determine the scaling properties of valley networks at smaller scales than have been previously assessed, using digital elevation models from the High Resolution Stereo Camera (HRSC). We find a Hack's law exponent of 0.74, larger than on Earth, and our measurements also reveal that individual small valleys have concave up, concave down, and quasi-linear longitudinal profiles, consistent with earlier studies of dissected terrain on Mars. However, for many valleys, widths are observed to increase downstream similarly to how they scale in terrestrial channels. The similarities and differences between valley networks on Mars and Earth are consistent with the idea that valleys on Mars are comparatively immature, and precipitation was a likely mechanism for delivering water to these networks.

  15. 27 CFR 9.100 - Mesilla Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Mesilla Valley. 9.100 Section 9.100 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Mesilla Valley viticultural area is located within Dona Ana County, New Mexico, and El Paso County, Texas...

  16. 27 CFR 9.100 - Mesilla Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Mesilla Valley. 9.100 Section 9.100 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Mesilla Valley viticultural area is located within Dona Ana County, New Mexico, and El Paso County, Texas...

  17. 27 CFR 9.78 - Ohio River Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Valley.” (b) Approved maps. The approved maps for determining the boundary of the Ohio River Valley... boundary proceeds in a straight line westerly to the town of Dry Ridge in Grant County, Kentucky...

  18. Numerical Simulation of Nocturnal Drainage Flows in Idealized Valley-Tributary Systems.

    NASA Astrophysics Data System (ADS)

    O'Steen, Lance B.

    2000-11-01

    Numerical simulations of nocturnal drainage flow and transport in idealized valley-tributary systems are compared with the Atmospheric Science in Complex Terrain (ASCOT) meteorological field data and tracer studies from the Brush Creek valley of western Colorado. Much of the general valley-tributary flow behavior deduced from observations is qualitatively reproduced in the numerical results. The spatially complex, unsteady nature of the tributary flow found in the field data is also seen in the simulations. Oscillations in the simulated tributary flow are similar to some field observations. However, observed oscillations in the valley flow at the mouth of the tributary could not be reproduced in the numerical results. Thus, hypotheses of strongly coupled valley-tributary flow oscillations, based on field data, cannot be supported by these simulations. Along-valley mass flux calculations based on model results for the valley-tributary system indicate an increase of 5%-10% over a valley without a tributary. Enhanced valley mass fluxes were found from 8 km above the tributary to almost the valley mouth. However, the valley mass fluxes for topography with and without a tributary were nearly equal at the valley outflow. ASCOT field data suggested a tributary mass flow contribution of 5%-15% for a Brush Creek tributary of similar drainage area to the model tributary employed here. Numerical simulations of transport in the nocturnal valley-tributary flow strongly support ASCOT tracer studies in the Pack Canyon tributary of Brush Creek. These results suggest that the valley-tributary interaction can significantly increase plume dispersion under stable conditions. Overall, the simulation results presented here indicate that simple terrain geometries are able to capture many of the salient features of drainage flow in real valley-tributary systems.

  19. The Valley Networks on Mars

    NASA Astrophysics Data System (ADS)

    Gulick, V. C.

    2002-12-01

    Despite three decades of exploration, the valley networks on Mars still seem to raise more questions than they answer. Valley systems have formed in the southern highlands, along some regions of the dichotomy boundary and the south rim of Valles Marineris, around the rim of some impact craters, and on the flanks of some volcanoes. They are found on some of the oldest and youngest terrains as well as on intermediate aged surfaces. There is surprisingly little consensus as to the formation and the paleoclimatic implications of the valley networks. Did the valleys require a persistent solar-driven atmospheric hydrological cycle involving precipitation, surface runoff, infiltration and groundwater outflow as they typically do on Earth? Or are they the result of magmatic or impact-driven thermal cycling of ground water involving persistent outflow and subsequent runoff? Are they the result of some other process(es)? Ground-water sapping, surface-water runoff, debris flows, wind erosion, and formation mechanisms involving other fluids have been proposed. Until such basic questions as these are definitively answered, their significance for understanding paleoclimatic change on Mars remains cloudy. I will review what is known about valley networks using data from both past and current missions. I will discuss what we have learned about their morphology, environments in which they formed, their spatial and temporal associations, possible formation mechanisms, relation to outflow channel and gully formation, as well as the possible implications for past climate change on Mars. Finally I will discuss how future, meter to submeter scale imaging and other remote sensing observations may shed new light on the debate over the origin of these enigmatic features.

  20. Death Valley California as seen from STS-59

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This oblique handheld Hasselblad 70mm photo shows Death Valley, near California's border with Nevada. The valley -- the central feature of Death Valley National Monument -- extends north to south for some 140 miles (225 kilometers). Hemmed in to the east by the Amargosa Range and to the west by the Panamints, its width varies from 5 to 15 miles (8 to 24 kilometers).

  1. Cuyahoga Valley National Park : comprehensive rail study

    DOT National Transportation Integrated Search

    2013-07-25

    Cuyahoga Valley Scenic Railroad (CVSR) has been operating in partnership with Cuyahoga Valley National Park (CVNP) since 1989 under a cooperative agreement. The railroad has been successfully developing and expanding services and ridership for the pa...

  2. Valley photonic crystals for control of spin and topology.

    PubMed

    Dong, Jian-Wen; Chen, Xiao-Dong; Zhu, Hanyu; Wang, Yuan; Zhang, Xiang

    2017-03-01

    Photonic crystals offer unprecedented opportunity for light manipulation and applications in optical communication and sensing. Exploration of topology in photonic crystals and metamaterials with non-zero gauge field has inspired a number of intriguing optical phenomena such as one-way transport and Weyl points. Recently, a new degree of freedom, valley, has been demonstrated in two-dimensional materials. Here, we propose a concept of valley photonic crystals with electromagnetic duality symmetry but broken inversion symmetry. We observe photonic valley Hall effect originating from valley-dependent spin-split bulk bands, even in topologically trivial photonic crystals. Valley-spin locking behaviour results in selective net spin flow inside bulk valley photonic crystals. We also show the independent control of valley and topology in a single system that has been long pursued in electronic systems, resulting in topologically-protected flat edge states. Valley photonic crystals not only offer a route towards the observation of non-trivial states, but also open the way for device applications in integrated photonics and information processing using spin-dependent transportation.

  3. Valley Hall effect and Nernst effect in strain engineered graphene

    NASA Astrophysics Data System (ADS)

    Niu, Zhi Ping; Yao, Jian-ming

    2018-04-01

    We theoretically predict the existence of tunneling valley Hall effect and Nernst effect in the normal/strain/normal graphene junctions, where a strained graphene is sandwiched by two normal graphene electrodes. By applying an electric bias a pure transverse valley Hall current with longitudinal charge current is generated. If the system is driven by a temperature bias, a valley Nernst effect is observed, where a pure transverse valley current without charge current propagates. Furthermore, the transverse valley current can be modulated by the Fermi energy and crystallographic orientation. When the magnetic field is further considered, we obtain a fully valley-polarized current. It is expected these features may be helpful in the design of the controllable valleytronic devices.

  4. Scaling relations for large Martian valleys

    NASA Astrophysics Data System (ADS)

    Som, Sanjoy M.; Montgomery, David R.; Greenberg, Harvey M.

    2009-02-01

    The dendritic morphology of Martian valley networks, particularly in the Noachian highlands, has long been argued to imply a warmer, wetter early Martian climate, but the character and extent of this period remains controversial. We analyzed scaling relations for the 10 large valley systems incised in terrain of various ages, resolvable using the Mars Orbiter Laser Altimeter (MOLA) and the Thermal Emission Imaging System (THEMIS). Four of the valleys originate in point sources with negligible contributions from tributaries, three are very poorly dissected with a few large tributaries separated by long uninterrupted trunks, and three exhibit the dendritic, branching morphology typical of terrestrial channel networks. We generated width-area and slope-area relationships for each because these relations are identified as either theoretically predicted or robust terrestrial empiricisms for graded precipitation-fed, perennial channels. We also generated distance-area relationships (Hack's law) because they similarly represent robust characteristics of terrestrial channels (whether perennial or ephemeral). We find that the studied Martian valleys, even the dendritic ones, do not satisfy those empiricisms. On Mars, the width-area scaling exponent b of -0.7-4.7 contrasts with values of 0.3-0.6 typical of terrestrial channels; the slope-area scaling exponent $\\theta$ ranges from -25.6-5.5, whereas values of 0.3-0.5 are typical on Earth; the length-area, or Hack's exponent n ranges from 0.47 to 19.2, while values of 0.5-0.6 are found on Earth. None of the valleys analyzed satisfy all three relations typical of terrestrial perennial channels. As such, our analysis supports the hypotheses that ephemeral and/or immature channel morphologies provide the closest terrestrial analogs to the dendritic networks on Mars, and point source discharges provide terrestrial analogs best suited to describe the other large Martian valleys.

  5. The Role of Source Material in Basin Sedimentation, as Illustrated within Eureka Valley, Death Valley National Park, CA.

    NASA Astrophysics Data System (ADS)

    Lawson, M. J.; Yin, A.; Rhodes, E. J.

    2015-12-01

    Steep landscapes are known to provide sediment to sink regions, but often petrological factors can dominate basin sedimentation. Within Eureka Valley, in northwestern Death Valley National Park, normal faulting has exposed a steep cliff face on the western margin of the Last Chance range with four kilometers of vertical relief from the valley floor and an angle of repose of nearly 38 degrees. The cliff face is composed of Cambrian limestone and dolomite, including the Bonanza King, Carrara and Wood Canyon formations. Interacting with local normal faulting, these units preferentially break off the cliff face in coherent blocks, which result in landslide deposits rather than as finer grained material found within the basin. The valley is well known for a large sand dune, which derives its sediment from distal sources to the north, instead of from the adjacent Last Chance Range cliff face. During the Holocene, sediment is sourced primary from the northerly Willow Wash and Cucomungo canyon, a relatively small drainage (less than 80 km2) within the Sylvan Mountains. Within this drainage, the Jurassic quartz monzonite of Beer Creek is heavily fractured due to motion of the Fish Valley Lake - Death Valley fault zone. Thus, the quartz monzonite is more easily eroded than the well-consolidated limestone and dolomite that forms the Last Change Range cliff face. As well, the resultant eroded material is smaller grained, and thus more easily transported than the limestone. Consequently, this work highlights an excellent example of the strong influence that source material can have on basin sedimentation.

  6. Boulder Valley Schools Teen Parenting Program.

    ERIC Educational Resources Information Center

    Parmerlee-Greiner, Gloria

    To meet the needs of pregnant and parenting adolescents in Boulder Valley (Colorado), the local public school district has developed the Boulder Valley Schools Teen Parenting Program, now in its 12th year. The program was designed to help teen parents to mature to meet the challenges of parenting, enhance the school district's dropout/intervention…

  7. Collective Bargaining Agreement between Antelope Valley Community College and Antelope Valley College Faculty Association, June 13, 1988.

    ERIC Educational Resources Information Center

    Antelope Valley Coll., Lancaster, CA.

    The collective bargaining agreement between Antelope Valley Community College and the Antelope Valley College Faculty Association outlines the terms of employment for all full- and part-time certificated employees of the District, covering the period from June 1988 to June 1990. The articles in the agreement set forth provisions related to: (1)…

  8. Volume of Valley Networks on Mars and Its Hydrologic Implications

    NASA Astrophysics Data System (ADS)

    Luo, W.; Cang, X.; Howard, A. D.; Heo, J.

    2015-12-01

    Valley networks on Mars are river-like features that offer the best evidence for water activities in its geologic past. Previous studies have extracted valley network lines automatically from digital elevation model (DEM) data and manually from remotely sensed images. The volume of material removed by valley networks is an important parameter that could help us infer the amount of water needed to carve the valleys. A progressive black top hat (PBTH) transformation algorithm has been adapted from image processing to extract valley volume and successfully applied to simulated landform and Ma'adim Valles, Mars. However, the volume of valley network excavation on Mars has not been estimated on a global scale. In this study, the PBTH method was applied to the whole Mars to estimate this important parameter. The process was automated with Python in ArcGIS. Polygons delineating the valley associated depressions were generated by using a multi-flow direction growth method, which started with selected high point seeds on a depth grid (essentially an inverted valley) created by PBTH transformation and grew outward following multi-flow direction on the depth grid. Two published versions of valley network lines were integrated to automatically select depression polygons that represent the valleys. Some crater depressions that are connected with valleys and thus selected in the previous step were removed by using information from a crater database. Because of large distortion associated with global dataset in projected maps, the volume of each cell within a valley was calculated using the depth of the cell multiplied by the spherical area of the cell. The volumes of all the valley cells were then summed to produce the estimate of global valley excavation volume. Our initial result of this estimate was ~2.4×1014 m3. Assuming a sediment density of 2900 kg/m3, a porosity of 0.35, and a sediment load of 1.5 kg/m3, the global volume of water needed to carve the valleys was

  9. Valley excitons in two-dimensional semiconductors

    DOE PAGES

    Yu, Hongyi; Cui, Xiaodong; Xu, Xiaodong; ...

    2014-12-30

    Monolayer group-VIB transition metal dichalcogenides have recently emerged as a new class of semiconductors in the two-dimensional limit. The attractive properties include: the visible range direct band gap ideal for exploring optoelectronic applications; the intriguing physics associated with spin and valley pseudospin of carriers which implies potentials for novel electronics based on these internal degrees of freedom; the exceptionally strong Coulomb interaction due to the two-dimensional geometry and the large effective masses. The physics of excitons, the bound states of electrons and holes, has been one of the most actively studied topics on these two-dimensional semiconductors, where the excitons exhibitmore » remarkably new features due to the strong Coulomb binding, the valley degeneracy of the band edges, and the valley dependent optical selection rules for interband transitions. Here we give a brief overview of the experimental and theoretical findings on excitons in two-dimensional transition metal dichalcogenides, with focus on the novel properties associated with their valley degrees of freedom.« less

  10. Drug-Trafficking and Police Corruption: A Comparison of Colombia and Mexico

    DTIC Science & Technology

    2008-06-01

    76 C ADMINISTRATIVE FACTORS IN MEXICO AND COLOMBIA.........77 1. The Police Recruitment Process in Mexico...77 2. The Police Recruitment Process in Colombia .................................79 3 Police Salaries, Resources...37 Figure 11. Departamento Administrativo de Seguridad (DAS) building in Bogota in 1989 after one of Pablo Escobar’s

  11. Geology and ground water in Russian River Valley areas and in Round, Laytonville, and Little Lake Valleys, Sonoma and Mendocino Counties, California

    USGS Publications Warehouse

    Cardwell, G.T.

    1965-01-01

    This report describes the occurrence, availability, and quality of ground water in seven valley areas along the course of the Russian River in Sonoma and Mendocino Counties, Calif., and in three valleys in the upper drainage reach of the Eel River in Mendocino County. Except for the westward-trending lower Russian River valley, the remaining valley areas along the Russian River (Healdsburg, Alexander, Cloverdale, Sanel, Ukiah, and Potter Valleys) lie in northwest-trending structurally controlled depressions formed in marine rocks of Jurassic and Cretaceous age. The principal aquifer in all the valleys is the alluvium of Recent age, which includes highly permeable channel deposits of gravel and sand. Water for domestic, irrigation, industrial, and other uses is developed by (1) direct diversion from the Russian River and its tributaries, (2) withdrawal of ground water and river water from shallow wells near the river, and (3) withdrawals of ground water from wells in alluvial deposits at varying distances from the river. Surface water in the Russian River and most tributaries is of good chemical quality. The water is a calcium magnesium bicarbonate type and contains 75,200 parts per million of dissolved solids. Ground water is also of good chemical quality throughout most of the drainage basin, but the concentration of dissolved solids (100-300 parts per million) is somewhat higher than that in the surface water. Round, Laytonville, and Little Lake Valleys are in central and northern Mendocino County in the drainage basin of the northwestward flowing Eel River. In Round Valley the alluvium of Recent age yields water of good chemical quality in large quantities. Yields are lower and the chemical quality poorer in Laytonville Valley. Ground water in Little Lake Valley is relatively undeveloped. Selected descriptions of wells, drillers' logs, chemical analyses, and hydrographs showing water-level fluctuations are included in the report. Accompanying maps show the

  12. New species and new records of Manota Williston from Colombia, Brazilian Amazonia, and Costa Rica (Diptera, Mycetophilidae).

    PubMed

    Kurina, Olavi; Hippa, Heikki; Amorim, Dalton de Souza

    2017-01-01

    The following five species are described as new: Manota clava sp. n. (Colombia), Manota multilobata sp. n. (Colombia), Manota perplexa sp. n. (Costa Rica), Manota setilobata sp. n. (Colombia) and Manota subaristata sp. n. (Colombia). In addition, new records for the following 11 species are presented: Manota acuminata Jaschhof & Hippa, 2005 (Costa Rica), Manota arenalensis Jaschhof & Hippa, 2005 (Costa Rica), Manota corcovado Jaschhof & Hippa, 2005 (Costa Rica), Manota costaricensis Jaschhof & Hippa, 2005 (Costa Rica), Manota diversiseta Jaschhof & Hippa, 2005 (Colombia, Brazilian Amazonia, Costa Rica), Manota minutula Hippa, Kurina & Sääksjärvi, 2017 (Brazilian Amazonia), Manota multisetosa Jaschhof & Hippa, 2005 (Costa Rica), Manota parva Jaschhof & Hippa, 2005 (Colombia, Costa Rica), Manota pisinna Hippa & Kurina, 2013 (Brazilian Amazonia), Manota spinosa Jaschhof & Hippa, 2005 (Colombia) and Manota squamulata Jaschhof & Hippa, 2005 (Costa Rica). Distribution patterns include (1) species known only locally in Costa Rica or Colombia, (2) distributions connecting Central America to west Andes lowlands, and (3) north-west Neotropical components, extending from Central America to Brazilian Amazonia. The possible biogeographical and taxonomical context of Manota species with a widespread distribution is considered.

  13. Modeling Soil Sodicity Problems under Dryland and Irrigated Conditions: Case Studies in Argentina and Colombia

    NASA Astrophysics Data System (ADS)

    Pla-Sentís, Ildefonso

    2014-05-01

    Salt-affected soils, both saline and sodic, my develop both under dryland and irrigated conditions, affecting negatively the physical and chemical soil properties, the crop production and the animal and human health.Among the development processes of salt-affected soils, the processes of sodification have been generally received less attention and is less understood than the development of saline soils. Although in both of them, hydrological processes are involved in their development, in the case of sodic soils we have to consider some additional chemical and physicochemical reactions, making more difficult their modeling and prediction. In this contribution we present two case studies: one related to the development of sodic soils in the lowlands of the Argentina Pampas, under dryland conditions and sub-humid temperate climate, with pastures for cattle production; the other deals with the development of sodic soils in the Colombia Cauca Valley, under irrigated conditions and tropical sub-humid climate, in lands used for sugarcane cropping dedicated to sugar and ethanol production. In both cases the development of sodicity in the surface soil is mainly related to the effects of the composition and level of groundwater, affected in the case of Argentina Pampas by the off-site changes in dryland use and management in the upper zones and by the drainage conditions in the lowlands, and in the case of the Cauca Valley, by the on-site irrigation and drainage management in lands with sugarcane. There is shown how the model SALSODIMAR, developed by the main author, based on the balance of water and soluble componentes of both the irrigation water and groundwater under different water and land management conditions, may be adapted for the diagnosis and prediction of both problems, and for the selection of alternatives for their management and amelioration.

  14. Observation of ultralong valley lifetime in WSe 2/MoS 2 heterostructures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kim, Jonghwan; Jin, Chenhao; Chen, Bin

    The valley degree of freedom in two-dimensional (2D) crystals recently emerged as a novel information carrier in addition to spin and charge. The intrinsic valley lifetime in 2D transition metal dichalcogenides (TMD) is expected to be markedly long due to the unique spin-valley locking behavior, where the intervalley scattering of the electron simultaneously requires a large momentum transfer to the opposite valley and a flip of the electron spin. However, the experimentally observed valley lifetime in 2D TMDs has been limited to tens of nanoseconds thus far. We report efficient generation of microsecond-long-lived valley polarization in WSe 2/MoS 2 heterostructuresmore » by exploiting the ultrafast charge transfer processes in the heterostructure that efficiently creates resident holes in the WSe 2 layer. These valley-polarized holes exhibit near-unity valley polarization and ultralong valley lifetime: We observe a valley-polarized hole population lifetime of more than 1 μs and a valley depolarization lifetime (that is, intervalley scattering lifetime) of more than 40 μs at 10 K. The near-perfect generation of valley-polarized holes in TMD heterostructures, combined with ultralong valley lifetime, which is orders of magnitude longer than previous results, opens up new opportunities for novel valleytronics and spintronics applications.« less

  15. Observation of ultralong valley lifetime in WSe 2/MoS 2 heterostructures

    DOE PAGES

    Kim, Jonghwan; Jin, Chenhao; Chen, Bin; ...

    2017-07-26

    The valley degree of freedom in two-dimensional (2D) crystals recently emerged as a novel information carrier in addition to spin and charge. The intrinsic valley lifetime in 2D transition metal dichalcogenides (TMD) is expected to be markedly long due to the unique spin-valley locking behavior, where the intervalley scattering of the electron simultaneously requires a large momentum transfer to the opposite valley and a flip of the electron spin. However, the experimentally observed valley lifetime in 2D TMDs has been limited to tens of nanoseconds thus far. We report efficient generation of microsecond-long-lived valley polarization in WSe 2/MoS 2 heterostructuresmore » by exploiting the ultrafast charge transfer processes in the heterostructure that efficiently creates resident holes in the WSe 2 layer. These valley-polarized holes exhibit near-unity valley polarization and ultralong valley lifetime: We observe a valley-polarized hole population lifetime of more than 1 μs and a valley depolarization lifetime (that is, intervalley scattering lifetime) of more than 40 μs at 10 K. The near-perfect generation of valley-polarized holes in TMD heterostructures, combined with ultralong valley lifetime, which is orders of magnitude longer than previous results, opens up new opportunities for novel valleytronics and spintronics applications.« less

  16. 27 CFR 9.76 - Knights Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Knights Valley. 9.76 Section 9.76 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.76 Knights Valley. (a) Name. The name of the viticultura...

  17. 27 CFR 9.29 - Sonoma Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Sonoma Valley. 9.29 Section 9.29 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.29 Sonoma Valley. (a) Name. The name of the viticultural...

  18. 27 CFR 9.23 - Napa Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Napa Valley. 9.23 Section 9.23 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.23 Napa Valley. (a) Name. The name of the viticultural area...

  19. 27 CFR 9.23 - Napa Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Napa Valley. 9.23 Section 9.23 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.23 Napa Valley. (a) Name. The name of the viticultural area...

  20. 27 CFR 9.76 - Knights Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Knights Valley. 9.76 Section 9.76 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.76 Knights Valley. (a) Name. The name of the viticultura...

  1. 27 CFR 9.29 - Sonoma Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Sonoma Valley. 9.29 Section 9.29 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.29 Sonoma Valley. (a) Name. The name of the viticultural...

  2. 27 CFR 9.23 - Napa Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Napa Valley. 9.23 Section 9.23 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.23 Napa Valley. (a) Name. The name of the viticultural area...

  3. 27 CFR 9.23 - Napa Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Napa Valley. 9.23 Section 9.23 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.23 Napa Valley. (a) Name. The name of the viticultural area...

  4. 27 CFR 9.142 - Bennett Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Bennett Valley. 9.142 Section 9.142 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.142 Bennett Valley. (a) Name. The name of the...

  5. 27 CFR 9.29 - Sonoma Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Sonoma Valley. 9.29 Section 9.29 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.29 Sonoma Valley. (a) Name. The name of the viticultural...

  6. 27 CFR 9.29 - Sonoma Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Sonoma Valley. 9.29 Section 9.29 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.29 Sonoma Valley. (a) Name. The name of the viticultural...

  7. 27 CFR 9.53 - Alexander Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Alexander Valley. 9.53 Section 9.53 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.53 Alexander Valley. (a) Name. The name of the...

  8. 27 CFR 9.53 - Alexander Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Alexander Valley. 9.53 Section 9.53 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.53 Alexander Valley. (a) Name. The name of the...

  9. 27 CFR 9.76 - Knights Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Knights Valley. 9.76 Section 9.76 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.76 Knights Valley. (a) Name. The name of the viticultura...

  10. 27 CFR 9.76 - Knights Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Knights Valley. 9.76 Section 9.76 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.76 Knights Valley. (a) Name. The name of the viticultura...

  11. 27 CFR 9.23 - Napa Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Napa Valley. 9.23 Section 9.23 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.23 Napa Valley. (a) Name. The name of the viticultural area...

  12. 27 CFR 9.29 - Sonoma Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Sonoma Valley. 9.29 Section 9.29 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.29 Sonoma Valley. (a) Name. The name of the viticultural...

  13. 27 CFR 9.142 - Bennett Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Bennett Valley. 9.142 Section 9.142 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.142 Bennett Valley. (a) Name. The name of the...

  14. 27 CFR 9.142 - Bennett Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Bennett Valley. 9.142 Section 9.142 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.142 Bennett Valley. (a) Name. The name of the...

  15. 27 CFR 9.142 - Bennett Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bennett Valley. 9.142 Section 9.142 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.142 Bennett Valley. (a) Name. The name of the...

  16. 27 CFR 9.53 - Alexander Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Alexander Valley. 9.53 Section 9.53 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.53 Alexander Valley. (a) Name. The name of the...

  17. 27 CFR 9.76 - Knights Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Knights Valley. 9.76 Section 9.76 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.76 Knights Valley. (a) Name. The name of the viticultura...

  18. 27 CFR 9.53 - Alexander Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Alexander Valley. 9.53 Section 9.53 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.53 Alexander Valley. (a) Name. The name of the...

  19. 27 CFR 9.53 - Alexander Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Alexander Valley. 9.53 Section 9.53 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.53 Alexander Valley. (a) Name. The name of the...

  20. 27 CFR 9.142 - Bennett Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Bennett Valley. 9.142 Section 9.142 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.142 Bennett Valley. (a) Name. The name of the...

  1. Rift Valley fever in Namibia, 2010.

    PubMed

    Monaco, Federica; Pinoni, Chiara; Cosseddu, Gian Mario; Khaiseb, Siegfried; Calistri, Paolo; Molini, Umberto; Bishi, Alec; Conte, Annamaria; Scacchia, Massimo; Lelli, Rossella

    2013-12-01

    During May-July 2010 in Namibia, outbreaks of Rift Valley fever were reported to the National Veterinary Service. Analysis of animal specimens confirmed virus circulation on 7 farms. Molecular characterization showed that all outbreaks were caused by a strain of Rift Valley fever virus closely related to virus strains responsible for outbreaks in South Africa during 2009-2010.

  2. East African Rift Valley, Kenya

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This rare, cloud free view of the East African Rift Valley, Kenya (1.5N, 35.5E) shows a clear view of the Turkwell River Valley, an offshoot of the African REift System. The East African Rift is part of a vast plate fracture which extends from southern Turkey, through the Red Sea, East Africa and into Mozambique. Dark green patches of forests are seen along the rift margin and tea plantations occupy the cooler higher ground.

  3. Proposed U.S.-Colombia Free Trade Agreement: Labor Issues

    DTIC Science & Technology

    2011-04-14

    Colombian President Juan Manual Santos, on April 7, 2011. If Congress were to approve the Colombia FTA, it would be the second FTA (after Peru ) to have some...production from Peru and Bolivia to Colombia in the 1980s increased drug violence and provided a new source of revenue for both guerrillas and...Nicaragua, Costa Rica, Peru , and Chile. The investment that goes into these other countries from the United States as a result, the Colombian

  4. Total carbon and nitrogen in mineral soil after 26 years of prescribed fire: Long Valley and Fort Valley Experimental Forests (P-53)

    Treesearch

    Daniel G. Neary; Sally M. Haase; Steven T. Overby

    2008-01-01

    Prescribed fire was introduced to high density ponderosa pine stands at Fort Valley and Long Valley Experimental Forests in 1976. This paper reports on mineral soil total carbon (C) and nitrogen (N) at Long Valley. Total soil C and N levels were highly variable and exhibited an increasing, but inconsistent, concentration trend related to burn interval. Total N ranged...

  5. Jaguar Densities across Human-Dominated Landscapes in Colombia: The Contribution of Unprotected Areas to Long Term Conservation

    PubMed Central

    Boron, Valeria; Tzanopoulos, Joseph; Gallo, Jenny; Barragan, Jorge; Jaimes-Rodriguez, Laura; Schaller, George; Payán, Esteban

    2016-01-01

    Large carnivores such as jaguars (Panthera onca) are species of conservation concern because they are suffering population declines and are keystone species in their ecosystems. Their large area requirements imply that unprotected and ever-increasing agricultural regions can be important habitats as they allow connectivity and dispersal among core protected areas. Yet information on jaguar densities across unprotected landscapes it is still scarce and crucially needed to assist management and range-wide conservation strategies. Our study provides the first jaguar density estimates of Colombia in agricultural regions which included cattle ranching, the main land use in the country, and oil palm cultivation, an increasing land use across the Neotropics. We used camera trapping across two agricultural landscapes located in the Magdalena River valley and in the Colombian llanos (47–53 stations respectively; >2000 trap nights at both sites) and classic and spatially explicit capture-recapture models with the sex of individuals as a covariate. Density estimates were 2.52±0.46–3.15±1.08 adults/100 km2 in the Magdalena valley, whereas 1.12±0.13–2.19±0.99 adults/100 km2 in the Colombian llanos, depending on analysis used. We suggest that jaguars are able to live across unprotected human-use areas and co-exist with agricultural landscapes including oil-palm plantations if natural areas and riparian habitats persist in the landscape and hunting of both jaguar and prey is limited. In the face of an expanding agriculture across the tropics we recommend land-use planning, adequate incentives, regulations, and good agricultural practices for range-wide jaguar connectivity and survival. PMID:27144280

  6. Valley switch in a graphene superlattice due to pseudo-Andreev reflection

    NASA Astrophysics Data System (ADS)

    Beenakker, C. W. J.; Gnezdilov, N. V.; Dresselhaus, E.; Ostroukh, V. P.; Herasymenko, Y.; Adagideli, I.; Tworzydło, J.

    2018-06-01

    Dirac electrons in graphene have a valley degree of freedom that is being explored as a carrier of information. In that context of "valleytronics" one seeks to coherently manipulate the valley index. Here, we show that reflection from a superlattice potential can provide a valley switch: Electrons approaching a pristine-graphene-superlattice-graphene interface near normal incidence are reflected in the opposite valley. We identify the topological origin of this valley switch, by mapping the problem onto that of Andreev reflection from a topological superconductor, with the electron-hole degree of freedom playing the role of the valley index. The valley switch is ideal at a symmetry point of the superlattice potential, but remains close to 100% in a broad parameter range.

  7. Wilderness, water, and quality of life in the Bitterroot Valley

    Treesearch

    Kari Gunderson; Clint Cook

    2007-01-01

    The Bitterroot Valley is located in western Montana, U.S.A. Most of the Bitterroot Range above the Bitterroot Valley is protected as wilderness, and is a source of much of the water that flows down and through the valley floor. With an annual precipitation of only 12.3 inches, the Bitterroot Valley is classified as a high desert environment. Today the quality of life...

  8. Fracture controls on valley persistence: the Cairngorm Granite pluton, Scotland

    NASA Astrophysics Data System (ADS)

    Hall, A. M.; Gillespie, M. R.

    2017-09-01

    Valleys are remarkably persistent features in many different tectonic settings, but the reasons for this persistence are rarely explored. Here, we examine the structural controls on valleys in the Cairngorms Mountains, Scotland, part of the passive margin of the eastern North Atlantic. We consider valleys at three scales: straths, glens and headwater valleys. The structural controls on valleys in and around the Cairngorm Granite pluton were examined on satellite and aerial photographs and by field survey. Topographic lineaments, including valleys, show no consistent orientation with joint sets or with sheets of microgranite and pegmatitic granite. In this granite landscape, jointing is not a first-order control on valley development. Instead, glens and headwater valleys align closely to quartz veins and linear alteration zones (LAZs). LAZs are zones of weakness in the granite pluton in which late-stage hydrothermal alteration and hydro-fracturing have greatly reduced rock mass strength and increased permeability. LAZs, which can be kilometres long and >700 m deep, are the dominant controls on the orientation of valleys in the Cairngorms. LAZs formed in the roof zone of the granite intrusion. Although the Cairngorm pluton was unroofed soon after emplacement, the presence of Old Red Sandstone (ORS) outliers in the terrain to the north and east indicates that the lower relief of the sub-ORS basement surface has been lowered by <500 m. Hence, the valley patterns in and around the Cairngorms have persisted through >1 km of vertical erosion and for 400 Myr. This valley persistence is a combined product of regionally low rates of basement exhumation and of the existence of LAZs in the Cairngorm pluton and sub-parallel Caledonide fractures in the surrounding terrain with depths that exceed 1 km.

  9. Proposed U.S.-Colombia Free Trade Agreement: Background and Issues

    DTIC Science & Technology

    2011-04-12

    to Colombia’s institutions and threaten the human rights of Colombian citizens. An independent candidate, Alvaro Uribe , won the 2002 presidential...president of Colombia with 69% of the vote. President Santos previously served as defense minister (2006-2009) under former President Alvaro Uribe and in...elections, largely because of his aggressive plan to reduce violence in Colombia. President Uribe , who served two terms in office, retained widespread

  10. Airborne Dust Models in Valley Fever Research

    NASA Astrophysics Data System (ADS)

    Sprigg, W. A.; Galgiani, J. N.; Vujadinovic, M.; Pejanovic, G.; Vukovic, A. J.; Prasad, A. K.; Djurdjevic, V.; Nickovic, S.

    2011-12-01

    Dust storms (haboobs) struck Phoenix, Arizona, in 2011 on July 5th and again on July 18th. One potential consequence: an estimated 3,600 new cases of Valley Fever in Maricopa County from the first storm alone. The fungi, Coccidioides immitis, the cause of the respiratory infection, Valley Fever, lives in the dry desert soils of the American southwest and southward through Mexico, Central America and South America. The fungi become part of the dust storm and, a few weeks after inhalation, symptoms of Valley Fever may appear, including pneumonia-like illness, rashes, and severe fatigue. Some fatalities occur. Our airborne dust forecast system predicted the timing and extent of the storm, as it has done with other, often different, dust events. Atmosphere/land surface models can be part of public health services to reduce risk of Valley Fever and exacerbation of other respiratory and cardiovascular illness.

  11. Evaluation of the United States Drug War Policy Abroad: A Case Study in Colombia

    DTIC Science & Technology

    2010-12-01

    Case Study in Colombia By: Kevin T. Wright and Joseph S. Hamilton December 2010 Advisors: David R. Henderson, John Enns...States Drug War Policy Abroad: A Case Study in Colombia 6. AUTHOR(S) Kevin T. Wright, Joseph S. Hamilton 5. FUNDING NUMBERS 7. PERFORMING...public release; distribution is unlimited EVALUATION OF THE UNITED STATES DRUG WAR POLICY ABROAD: A CASE STUDY IN COLOMBIA Kevin T. Wright

  12. California: Diamond Valley

    Atmospheric Science Data Center

    2014-05-15

    ... article title:  Watching the Creation of Southern California's Largest Reservoir     ... Valley Lake is designed to provide protection against drought and a six-month emergency supply in the event of earthquake damage to a ...

  13. Mzab Valley, Algeria

    NASA Image and Video Library

    2011-03-24

    Located 600 km south of Algiers, Algeria in the heart of the Sahara Desert, the five ksour fortified villages of the MZab Valley form an extraordinarily homogenous ensemble in this image captured by NASA Terra spacecraft.

  14. Colombia. America = Las Americas [Series].

    ERIC Educational Resources Information Center

    Toro, Leonor; Doran, Sandra

    Written for teachers to use with migrant children in elementary grades to highlight the many Americas, this bilingual English/Spanish social studies resource booklet provides historical and cultural background information on Colombia and features biographies of Colombian leaders and artists. A table of contents indicates the language--Spanish or…

  15. Spin- and Valley-Dependent Electronic Structure in Silicene Under Periodic Potentials

    NASA Astrophysics Data System (ADS)

    Lu, Wei-Tao; Li, Yun-Fang; Tian, Hong-Yu

    2018-03-01

    We study the spin- and valley-dependent energy band and transport property of silicene under a periodic potential, where both spin and valley degeneracies are lifted. It is found that the Dirac point, miniband, band gap, anisotropic velocity, and conductance strongly depend on the spin and valley indices. The extra Dirac points appear as the voltage potential increases, the critical values of which are different for electron with different spins and valleys. Interestingly, the velocity is greatly suppressed due to the electric field and exchange field, other than the gapless graphene. It is possible to achieve an excellent collimation effect for a specific spin near a specific valley. The spin- and valley-dependent band structure can be used to adjust the transport, and perfect transmissions are observed at Dirac points. Therefore, a remarkable spin and valley polarization is achieved which can be switched effectively by the structural parameters. Importantly, the spin and valley polarizations are greatly enhanced by the disorder of the periodic potential.

  16. 2012-2013 Delaware Valley Household Travel Survey | Transportation Secure

    Science.gov Websites

    Data Center | NREL 12-2013 Delaware Valley Household Travel Survey 2012-2013 Delaware Valley Household Travel Survey The 2012-2013 Delaware Valley Household Travel Survey collected data for multiple ) sponsored the survey in collaboration with AbtSRBI. Methodology A sampling strategy was designed to recruit

  17. Fluvial valleys on Martian volcanoes

    NASA Technical Reports Server (NTRS)

    Baker, Victor R.; Gulick, Virginia C.

    1987-01-01

    Channels and valleys were known on the Martian volcanoes since their discovery by the Mariner 9 mission. Their analysis has generally centered on interpretation of possible origins by fluvial, lava, or viscous flows. The possible fluvial dissection of Martian volcanoes has received scant attention in comparison to that afforded outflow, runoff, and fretted channels. Photointerpretative, mapping, and morphometric studies of three Martian volcanoes were initiated: Ceraunius Tholus, Hecate Tholus, and Alba Patera. Preliminary morphometric results indicate that, for these three volcanoes, valley junction angles increase with decreasing slope. Drainage densities are quite variable, apparently reflecting complex interactions in the landscape-forming factors described. Ages of the Martian volcanoes were recently reinterpreted. This refined dating provides a time sequence in which to evaluate the degradational forms. An anomaly has appeared from the initial study: fluvial valleys seem to be present on some Martian volcanoes, but not on others of the same age. Volcanic surfaces characterized only by high permeability lava flows may have persisted without fluvial dissection.

  18. Directional interlayer spin-valley transfer in two-dimensional heterostructures

    DOE PAGES

    Schaibley, John R.; Rivera, Pasqual; Yu, Hongyi; ...

    2016-12-14

    Van der Waals heterostructures formed by two different monolayer semiconductors have emerged as a promising platform for new optoelectronic and spin/valleytronic applications. In addition to its atomically thin nature, a two-dimensional semiconductor heterostructure is distinct from its three-dimensional counterparts due to the unique coupled spin-valley physics of its constituent monolayers. In this paper, we report the direct observation that an optically generated spin-valley polarization in one monolayer can be transferred between layers of a two-dimensional MoSe 2–WSe 2 heterostructure. Using non-degenerate optical circular dichroism spectroscopy, we show that charge transfer between two monolayers conserves spin-valley polarization and is only weaklymore » dependent on the twist angle between layers. Finally, our work points to a new spin-valley pumping scheme in nanoscale devices, provides a fundamental understanding of spin-valley transfer across the two-dimensional interface, and shows the potential use of two-dimensional semiconductors as a spin-valley generator in two-dimensional spin/valleytronic devices for storing and processing information.« less

  19. 76 FR 67055 - Amendment of Class E Airspace; Valley City, ND

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-31

    ...-0605; Airspace Docket No. 11-AGL-13] Amendment of Class E Airspace; Valley City, ND AGENCY: Federal... Valley City, ND. Decommissioning of the Valley City non-directional beacon (NDB) at Barnes County Municipal Airport, Valley City, ND, has made this action necessary to enhance the safety and management of...

  20. Valley floor climate observations from the McMurdo dry valleys, Antarctica, 1986-2000

    USGS Publications Warehouse

    Doran, P.T.; McKay, C.P.; Clow, G.D.; Dana, G.L.; Fountain, A.G.; Nylen, T.; Lyons, W.B.

    2002-01-01

    Climate observations from the McMurdo dry valleys, East Antarctica are presented from a network of seven valley floor automatic meteorological stations during the period 1986 to 2000. Mean annual temperatures ranged from -14.8??C to -30.0??C, depending on the site and period of measurement. Mean annual relative humidity is generally highest near the coast. Mean annual wind speed increases with proximity to the polar plateau. Site-to-site variation in mean annual solar flux and PAR is due to exposure of each station and changes over time are likely related to changes in cloudiness. During the nonsummer months, strong katabatic winds are frequent at some sites and infrequent at others, creating large variation in mean annual temperature owing to the warming effect of the winds. Katabatic wind exposure appears to be controlled to a large degree by the presence of colder air in the region that collects at low points and keeps the warm less dense katabatic flow from the ground. The strong influence of katabatic winds makes prediction of relative mean annual temperature based on geographical position (elevation and distance from the coast) alone, not possible. During the summer months, onshore winds dominate and warm as they progress through the valleys creating a strong linear relationship (r2 = 0.992) of increasing potential temperature with distance from the coast (0.09??C km-1). In contrast to mean annual temperature, summer temperature lends itself quite well to model predictions, and is used to construct a statistical model for predicting summer dry valley temperatures at unmonitored sites. Copyright 2002 by the American Geophysical Union.

  1. A new species of Espeletiopsis (Millerieae, Asteraceae) from Colombia

    PubMed Central

    Diazgranados, Mauricio; Sánchez, Luis Roberto

    2013-01-01

    Abstract A new species of Espeletiopsis was found in two small páramos of Norte de Santander, Colombia. The species is named Espeletiopsis diazii honoring the contributions of Santiago Díaz-Piedrahita in recognition of his vast knowledge of the Compositae in Colombia. This is a very distinctive species, markedly different from most of the Espeletiopsis present in Colombia. The new species is closely related to Espeletiopsis caldasii and Espeletiopsis santanderensis, but differs in having (1–)4–6(–7) capitula, with very short peduncles, and capitula arranged in a compact or densely glomerate cyme. With a total distribution area of less than 75 km2, this species is probably critically endangered or imperiled. PMID:24399905

  2. Electrical control of the anomalous valley Hall effect in antiferrovalley bilayers

    NASA Astrophysics Data System (ADS)

    Tong, Wen-Yi; Duan, Chun-Gang

    2017-08-01

    In analogy to all-electric spintronics, all-electric valleytronics, i.e., valley manipulation via electric means, becomes an exciting new frontier as it may bring revolutions in the field of data storage with ultra-high speed and ultra-low power consumption. The existence of the anomalous valley Hall effect in ferrovalley materials demonstrates the possibility of electrical detection for valley polarization. However, in previously proposed valley-polarized monolayers, the anomalous valley Hall effect is controlled by external magnetic fields. Here, through elaborate structural design, we propose the antiferrovally bilayer as an ideal candidate for realizing all-electric valleytronic devices. Using the minimal k.p model, we show that the energy degeneracy between valley indexes in such system can be lifted by electric approaches. Subsequently, the anomalous valley Hall effect strongly depends on the electric field as well. Taking the bilayer VSe2 as an example, all-electric tuning and detecting of anomalous valley Hall effect is confirmed by density-functional theory calculations, indicating that the valley information in such antiferrovalley bilayer can be reversed by an electric field perpendicular to the plane of the system and easily probed through the sign of the Hall voltage.

  3. Hydrologic reconnaissance of Rush Valley, Tooele County, Utah

    USGS Publications Warehouse

    Hood, James W.; Price, Don; Waddell, K.M.

    1969-01-01

    This report is the third in a series by the U. S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, which describes the water resources of the western basins of Utah. Its purpose is to present available hydrologic data for Rush Valley, to provide an evaluation of the potential water-resources development of the valley, and to identify needed studies that would help provide an understanding of the valley's water supply.

  4. Hydrologic reconnaissance of Skull Valley, Tooele County, Utah

    USGS Publications Warehouse

    Hood, James W.; Waddell, K.M.

    1968-01-01

    This report is the second in a series by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, which describes the water resources of the western basins of Utah. Its purpose is to present available hydrologic data on Skull Valley, to provide an evaluation of the potential water-resource development of the valley, and to identify needed studies that would help provide an understandingof the valley's water supply.

  5. Democratic Governance and the Rule of Law: Lessons from Colombia

    DTIC Science & Technology

    2009-12-01

    DEMOCRATIC GOVERNANCE AND THE RULE OF LAW: LESSONS FROM COLOMBIA Gabriel Marcella December 2009 The views expressed in this report are those of the... Government . Authors of Strategic Studies Institute (SSI) publications enjoy full academic freedom, provided they do not disclose classified information...DATES COVERED 00-00-2009 to 00-00-2009 4. TITLE AND SUBTITLE Democratic Governance and the Rule of Law: Lessons from Colombia 5a. CONTRACT NUMBER

  6. Death Valley, California

    NASA Image and Video Library

    2009-06-29

    Death Valley, Calif., has the lowest point in North America, Badwater at 85.5 meters 282 feet below sea level. It is also the driest and hottest location in North America. This image is from NASA Terra spacecraft.

  7. Air flow analysis in the upper Río Negro Valley (Argentina)

    NASA Astrophysics Data System (ADS)

    Cogliati, M. G.; Mazzeo, N. A.

    2006-06-01

    The so called Upper Río Negro Valley in Argentina is one of the most important fruit and vegetable production regions of the country. It comprises the lower valleys of the Limay and Neuquén rivers and the upper Negro river valley. Out of the 41,671 cultivated hectares, 84.6% are cultivated with fruit trees, especially apple, pear and stone fruit trees. Late frosts occurring when trees are sensitive to low temperatures have a significant impact on the regional production. This study presents an analysis of air flow characteristics in the Upper Río Negro Valley and its relationship with ambient air flow. To such effect, observations made when synoptic-scale weather patterns were favorable for radiative frosts (light wind and clear sky) or nocturnal temperature inversion in the lower layer were used. In the Negro river valley, both wind channeling and downward horizontal momentum transport from ambient wind were observed; in nighttime, very light wind events occurred, possibly associated with drainage winds from the nearby higher levels of the barda. In the Neuquén river valley, the prevailing effect appeared to be forced channeling, consistent with the results obtained in valleys where the synoptic scale wind crossed the axis of the valley. In the Limay river valley, the flow was observed to blow parallel to the longitudinal valley axis, possibly influenced by pressure gradient and forced channeling.

  8. Titan's fluvial valleys: Morphology, distribution, and spectral properties

    USGS Publications Warehouse

    Langhans, M.H.; Jaumann, R.; Stephan, K.; Brown, R.H.; Buratti, B.J.; Clark, R.N.; Baines, K.H.; Nicholson, P.D.; Lorenz, R.D.; Soderblom, L.A.; Soderblom, J.M.; Sotin, Christophe; Barnes, J.W.; Nelson, R.

    2012-01-01

    Titan's fluvial channels have been investigated based on data obtained by the Synthetic Aperture Radar (SAR) instrument and the Visible and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft. In this paper, a database of fluvial features is created based on radar-SAR data aiming to unveil the distribution and the morphologic and spectral characteristics of valleys on Titan on a global scale. It will also study the spatial relations between fluvial valleys and Titan's geologic units and spectral surface units which have become accessible thanks to Cassini-VIMS data. Several distinct morphologic types of fluvial valleys can be discerned by SAR-images. Dendritic valley networks appear to have much in common with terrestrial dendritic systems owing to a hierarchical and tree-shaped arrangement of the tributaries which is indicative of an origin from precipitation. Dry valleys constitute another class of valleys resembling terrestrial wadis, an indication of episodic and strong flow events. Other valley types, such as putative canyons, cannot be correlated with rainfall based on their morphology alone, since it cannot be ruled out that they may have originated from volcanic/tectonic action or groundwater sapping. Highly developed and complex fluvial networks with channel lengths of up to 1200 km and widths of up to 10 km are concentrated only at a few locations whereas single valleys are scattered over all latitudes. Fluvial valleys are frequently found in mountainous areas. Some terrains, such as equatorial dune fields and undifferentiated plains at mid-latitudes, are almost entirely free of valleys. Spectrally, fluvial terrains are often characterized by a high reflectance in each of Titan's atmospheric windows, as most of them are located on Titan's bright 'continents'. Nevertheless, valleys are spatially associated with a surface unit appearing blue due to its higher reflection at 1.3??m in a VIMS false color RGB composite with R: 1.59/1.27??m, G: 2

  9. Erosion of steepland valleys by debris flows

    USGS Publications Warehouse

    Stock, J.D.; Dietrich, W.E.

    2006-01-01

    Episodic debris flows scour the rock beds of many steepland valleys. Along recent debris-flow runout paths in the western United States, we have observed evidence for bedrock lowering, primarily by the impact of large particles entrained in debris flows. This evidence may persist to the point at which debris-flow deposition occurs, commonly at slopes of less than ???0.03-0.10. We find that debris-flow-scoured valleys have a topographic signature that is fundamentally different from that predicted by bedrock river-incision models. Much of this difference results from the fact that local valley slope shows a tendency to decrease abruptly downstream of tributaries that contribute throughgoing debris flows. The degree of weathering of valley floor bedrock may also decrease abruptly downstream of such junctions. On the basis of these observations, we hypothesize that valley slope is adjusted to the long-term frequency of debris flows, and that valleys scoured by debris flows should not be modeled using conventional bedrock river-incision laws. We use field observations to justify one possible debris-flow incision model, whose lowering rate is proportional to the integral of solid inertial normal stresses from particle impacts along the flow and the number of upvalley debris-flow sources. The model predicts that increases in incision rate caused by increases in flow event frequency and length (as flows gain material) downvalley are balanced by rate reductions from reduced inertial normal stress at lower slopes, and stronger, less weathered bedrock. These adjustments lead to a spatially uniform lowering rate. Although the proposed expression leads to equilibrium long-profiles with the correct topographic signature, the crudeness with which the debris-flow dynamics are parameterized reveals that we are far from a validated debris-flow incision law. However, the vast extent of steepland valley networks above slopes of ???0.03-0.10 illustrates the need to understand debris

  10. Groundwater quality in Coachella Valley, California

    USGS Publications Warehouse

    Dawson, Barbara J. Milby; Belitz, Kenneth

    2012-01-01

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Coachella Valley is one of the study areas being evaluated. The Coachella study area is approximately 820 square miles (2,124 square kilometers) and includes the Coachella Valley groundwater basin (California Department of Water Resources, 2003). Coachella Valley has an arid climate, with average annual rainfall of about 6 inches (15 centimeters). The runoff from the surrounding mountains drains to rivers that flow east and south out of the study area to the Salton Sea. Land use in the study area is approximately 67 percent (%) natural, 21% agricultural, and 12% urban. The primary natural land cover is shrubland. The largest urban areas are the cities of Indio and Palm Springs (2010 populations of 76,000 and 44,000, respectively). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in Coachella Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Coachella Valley are completed to depths between 490 and 900 feet (149 to 274 meters), consist of solid casing from the land surface to a depth of 260 to 510 feet (79 to 155 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the surrounding mountains, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to

  11. Rift Valley fever outbreak, southern Mauritania, 2012.

    PubMed

    Sow, Abdourahmane; Faye, Ousmane; Ba, Yamar; Ba, Hampathé; Diallo, Diawo; Faye, Oumar; Loucoubar, Cheikh; Boushab, Mohamed; Barry, Yahya; Diallo, Mawlouth; Sall, Amadou Alpha

    2014-02-01

    After a period of heavy rainfall, an outbreak of Rift Valley fever occurred in southern Mauritania during September-November 2012. A total of 41 human cases were confirmed, including 13 deaths, and 12 Rift Valley fever virus strains were isolated. Moudjeria and Temchecket Departments were the most affected areas.

  12. Genetic Structure of Anopheles (Nyssorhynchus) marajoara (Diptera: Culicidae) in Colombia

    PubMed Central

    Brochero, Helena; Li, Cong; Wilkerson, Richard; Conn, Jan E.; Ruiz-García, Manuel

    2010-01-01

    Five Anopheles marajoara Galvão and Damasceno populations, representing diverse ecological conditions, were sampled throughout Colombia and analyzed using nine hypervariable DNA microsatellite loci. The overall genetic diversity (H = 0.58) was lower than that determined for some Brazilian populations using the same markers. The Caquetá population (Colombia) had the lowest gene diversity (H = 0.48), and it was the only population at Hardy–Weinberg equilibrium. Hardy–Weinberg disequilibrium in the remaining four populations was probably caused by the Wahlund effect. The assignment analyses showed two incompletely isolated gene pools separated by the Eastern Andean cordillera. However, other possible geographical barriers (rivers and other mountains) did not play any role in the moderate genetic heterogeneity found among these populations (FST = 0.069). These results are noteworthy, because this species is a putative malaria vector in Colombia. PMID:20810825

  13. Rocky Mountain spotted fever, Colombia.

    PubMed

    Hidalgo, Marylin; Orejuela, Leonora; Fuya, Patricia; Carrillo, Pilar; Hernandez, Jorge; Parra, Edgar; Keng, Colette; Small, Melissa; Olano, Juan P; Bouyer, Donald; Castaneda, Elizabeth; Walker, David; Valbuena, Gustavo

    2007-07-01

    We investigated 2 fatal cases of Rocky Mountain spotted fever that occurred in 2003 and 2004 near the same locality in Colombia where the disease was first reported in the 1930s. A retrospective serosurvey of febrile patients showed that > 21% of the serum samples had antibodies aaainst spotted fever group rickettsiae.

  14. Solving Colombia’s Problems

    DTIC Science & Technology

    2003-04-07

    parties for political control during the period from 1948 to 1953.15 “During this period, referred to as ‘La Violencia ,’ groups of armed men paid by...surprise to those familiar with the Colombia government history of mishandling foreign aid in the war against drugs and in their parallel inability to

  15. 27 CFR 9.37 - California Shenandoah Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false California Shenandoah Valley. 9.37 Section 9.37 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU...) Boundaries. The Shenandoah Valley viticultural Area is located in portions of Amador and El Dorado Counties...

  16. 27 CFR 9.37 - California Shenandoah Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false California Shenandoah Valley. 9.37 Section 9.37 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU...) Boundaries. The Shenandoah Valley viticultural Area is located in portions of Amador and El Dorado Counties...

  17. 27 CFR 9.25 - San Pasqual Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... They are entitled: (1) “Escondido Quadrangle, California—San Diego County”, 7.5 minute series; (2) “San Pasqual Quadrangle, California—San Diego County”, 7.5 minute series; (3) “Valley Center Quadrangle, California—San Diego County”, 7.5 minute series. (c) Boundaries. The San Pasqual Valley viticultural area is...

  18. 27 CFR 9.25 - San Pasqual Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... They are entitled: (1) “Escondido Quadrangle, California—San Diego County”, 7.5 minute series; (2) “San Pasqual Quadrangle, California—San Diego County”, 7.5 minute series; (3) “Valley Center Quadrangle, California—San Diego County”, 7.5 minute series. (c) Boundaries. The San Pasqual Valley viticultural area is...

  19. 27 CFR 9.25 - San Pasqual Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... They are entitled: (1) “Escondido Quadrangle, California—San Diego County”, 7.5 minute series; (2) “San Pasqual Quadrangle, California—San Diego County”, 7.5 minute series; (3) “Valley Center Quadrangle, California—San Diego County”, 7.5 minute series. (c) Boundaries. The San Pasqual Valley viticultural area is...

  20. 27 CFR 9.25 - San Pasqual Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... They are entitled: (1) “Escondido Quadrangle, California—San Diego County”, 7.5 minute series; (2) “San Pasqual Quadrangle, California—San Diego County”, 7.5 minute series; (3) “Valley Center Quadrangle, California—San Diego County”, 7.5 minute series. (c) Boundaries. The San Pasqual Valley viticultural area is...

  1. 27 CFR 9.25 - San Pasqual Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... They are entitled: (1) “Escondido Quadrangle, California—San Diego County”, 7.5 minute series; (2) “San Pasqual Quadrangle, California—San Diego County”, 7.5 minute series; (3) “Valley Center Quadrangle, California—San Diego County”, 7.5 minute series. (c) Boundaries. The San Pasqual Valley viticultural area is...

  2. Detection and Response for Rift Valley fever

    USDA-ARS?s Scientific Manuscript database

    Rift Valley fever is a viral disease that impacts domestic livestock and humans in Africa and the Middle East, and poses a threat to military operations in these areas. We describe a Rift Valley fever Risk Monitoring website, and its ability to predict risk of disease temporally and spatially. We al...

  3. Illinois Valley Industry Retention Program. Final Report.

    ERIC Educational Resources Information Center

    Allen, John P.

    The Illinois Valley Industry Retention Program was conceived with the goals of retaining existing industries in the area and saving presently available jobs for the area's citizens. A program committee, formed in March 1982 of representatives from state government, Illinois Valley Community College (IVCC), and local businesses, undertook a survey…

  4. An Ancient Valley Network

    NASA Image and Video Library

    2017-05-09

    Most of the oldest terrains on Mars have eroded into branching valleys, as seen here in by NASA's Mars Reconnaisance Orbiter, much like many land regions of Earth are eroded by rain and snowmelt runoff. This is the primary evidence for major climate change on Mars billions of years ago. How the climate of Mars could have supported a warmer and wetter environment has been the subject of scientific debates for 40 years. A full-resolution enhanced color closeup reveals details in the bedrock and dunes on the valley floor (upper left). The bedrock of ancient Mars has been hardened and cemented by groundwater. https://photojournal.jpl.nasa.gov/catalog/PIA21630

  5. Subglacial tunnel valleys dissecting the Alpine landscape - an example from Bern, Switzerland

    NASA Astrophysics Data System (ADS)

    Dürst Stucki, Mirjam; Reber, Regina; Schlunegger, Fritz

    2010-05-01

    The morphology of the Alpine and adjacent landscapes is directly related to glacial erosion and associated sediment transport. Here we report the effects of glacio-hydrologic erosion on bedrock topography in the Swiss Mittelland. Specifically, we identify the presence of subsurface valleys beneath the city of Bern in Switzerland and discuss their genesis. Detailed stratigraphic investigations of more than 4000 borehole data within a 430 km2-large area reveal the presence of a network of >200 m-deep and 1000 m-wide valleys. They are flat floored with steep sided walls and are filled by Quaternary fluvio-glacial deposits. The main valley beneath Bern is straight and oriented towards the NNW, with valley flanks more than 20° steep. The valley bottom has an irregular undulating profile along the thalweg, with differences between sills and hollows higher than 50-100 m over a reach of 4 kilometers length. Approximately 200 m high bedrock uplands flank the valley network. The uplands are dissected by up to 80 m-deep and 500 m-broad hanging valleys that currently drain away from the axis of the main valley. We interpret the valleys beneath the city of Bern to be a tunnel valley network which originated from subglacial erosion by melt water. The upland valleys are hanging with respect to the trunk system, indicating that these incipient upland systems as well as the main gorge beneath Bern formed by glacial melt water under hydrostatic pressure. This explains the ascending flow of glacial water from the base towards the higher elevation hanging valleys where high water discharge resulted in the formation of broad valley geometries. Similarly, we relate efficient erosion, excavation of bedrock and the formation of the tunnel valley network with >20° steep shoulders to confined flow under pressure, caused by the overlying ice.

  6. 78 FR 15346 - Secretarial Infrastructure Business Development Mission to Brazil, Colombia and Panama; May 12-18...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-11

    ... Development Mission to Brazil, Colombia and Panama; May 12-18, 2013 AGENCY: International Trade Administration...[aacute], Colombia and Panama City, Panama from May 12-18, 2013. This business development mission will... 12-18, 2013) Colombia and Panama (May 14-18, 2013) The delegation will be composed of 20-25 U.S...

  7. EPA Region 1 - Map Layers for Valley ID Tool (Hosted Feature Service)

    EPA Pesticide Factsheets

    The Valley Service Feature Layer hosts spatial data for EPA Region 1's Valley Identification Tool. These layers contain attribute information added by EPA R1 GIS Center to help identify populated valleys:- Fac_2011NEI: Pollution sources selected from the National Emissions Inventory (EPA, 2011).- NE_Towns_PopValleys: New England Town polygons (courtesy USGS), with Population in Valleys and Population Density in Valleys calculated by EPA R1 GIS, from 2010 US Census blocks. - VT_E911: Vermont residences (courtesy VT Center for Geographic Information E-911).

  8. Valley photonic crystals for control of spin and topology

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dong, Jian-Wen; Chen, Xiao-Dong; Zhu, Hanyu

    2016-11-28

    Photonic crystals offer unprecedented opportunity for light manipulation and applications in optical communication and sensing1,2,3,4. Exploration of topology in photonic crystals and metamaterials with non-zero gauge field has inspired a number of intriguing optical phenomena such as one-way transport and Weyl points5,6,7,8,9,10. Recently, a new degree of freedom, valley, has been demonstrated in two-dimensional materials11,12,13,14,15. Here, we propose a concept of valley photonic crystals with electromagnetic duality symmetry but broken inversion symmetry. We observe photonic valley Hall effect originating from valley-dependent spin-split bulk bands, even in topologically trivial photonic crystals. Valley–spin locking behaviour results in selective net spin flow insidemore » bulk valley photonic crystals. We also show the independent control of valley and topology in a single system that has been long pursued in electronic systems, resulting in topologically-protected flat edge states. Valley photonic crystals not only offer a route towards the observation of non-trivial states, but also open the way for device applications in integrated photonics and information processing using spin-dependent transportation.« less

  9. Valley Physics in Non-Hermitian Artificial Acoustic Boron Nitride

    NASA Astrophysics Data System (ADS)

    Wang, Mudi; Ye, Liping; Christensen, J.; Liu, Zhengyou

    2018-06-01

    The valley can serve as a new degree of freedom in the manipulation of particles or waves in condensed matter physics, whereas systems containing combinations of gain and loss elements constitute rich building units that can mimic non-Hermitian properties. By introducing gain and loss in artificial acoustic boron nitride, we show that the acoustic valley states and the valley-projected edge states display exotic behaviors in that they sustain either attenuated or amplified wave propagation. Our findings show how non-Hermiticity introduces a mechanism in tuning topological protected valley transports, which may have significance in advanced wave control for sensing and communication applications.

  10. Mental health service delivery following health system reform in Colombia.

    PubMed

    Romero-González, Mauricio; González, Gerardo; Rosenheck, Robert A

    2003-12-01

    In 1993, Colombia underwent an ambitious and comprehensive process of health system reform based on managed competition and structured pluralism, but did not include coverage for mental health services. In this study, we sought to evaluate the impact of the reform on access to mental health services and whether there were changes in the pattern of mental health service delivery during the period after the reform. Changes in national economic indicators and in measures of mental health and non-mental health service delivery for the years 1987 and 1997 were compared. Data were obtained from the National Administrative Department of Statistics of Colombia (DANE), the Department of National Planning and Ministry of the Treasury of Colombia, and from national official reports of mental health and non-mental health service delivery from the Ministry of Health of Colombia for the same years. While population-adjusted access to mental health outpatient services declined by -2.7% (-11.2% among women and +5.8% among men), access to general medical outpatient services increased dramatically by 46%. In-patient admissions showed smaller differences, with a 7% increase in mental health admissions, as compared to 22.5% increase in general medical admissions. The health reform in Colombia imposed competition across all health institutions with the intention of encouraging efficiency and financial autonomy. However, the challenge of institutional survival appears to have fallen heavily on mental health care institutions that were also expected to participate in managed competition, but that were at a serious disadvantage because their services were excluded from the compulsory standardized package of health benefits. While the Colombian health care reform intended to close the gap between those who had and those who did not have access to health services, it appears to have failed to address access to specialized mental health services, although it does seem to have promoted a

  11. Smart Valley Infrastructure.

    ERIC Educational Resources Information Center

    Maule, R. William

    1994-01-01

    Discusses prototype information infrastructure projects in northern California's Silicon Valley. The strategies of the public and private telecommunications carriers vying for backbone services and industries developing end-user infrastructure technologies via office networks, set-top box networks, Internet multimedia, and "smart homes"…

  12. Counterterrorism Policy in Colombia

    DTIC Science & Technology

    2007-06-01

    Grievance-based insurgencies are the most familiar type of insurgency because of their frequency during the Cold War. These insurgencies arise due...tumultuous period in Colombian history known as La Violencia . During this period, 1948-1964, the two primary political parties in Colombia, the Liberals...themselves and their property.34 These ’self-defense’ groups were the precursor to the FARC. La Violencia ended with the formation of the National

  13. Acoustic valley edge states in a graphene-like resonator system

    NASA Astrophysics Data System (ADS)

    Yang, Yahui; Yang, Zhaoju; Zhang, Baile

    2018-03-01

    The concept of valley physics, as inspired by the recent development in valleytronic materials, has been extended to acoustic crystals for manipulation of air-borne sound. Many valleytronic materials follow the model of a gapped graphene. Yet the previously demonstrated valley acoustic crystal adopted a mirror-symmetry-breaking mechanism, lacking a direct counterpart in condensed matter systems. In this paper, we investigate a two-dimensional (2D) periodic acoustic resonator system with inversion symmetry breaking, as an analogue of a gapped graphene monolayer. It demonstrates the quantum valley Hall topological phase for sound waves. Similar to a gapped graphene, gapless topological valley edge states can be found at a zigzag domain wall separating different domains with opposite valley Chern numbers, while an armchair domain wall hosts no gapless edge states. Our study offers a route to simulate novel valley phenomena predicted in gapped graphene and other 2D materials with classical acoustic waves.

  14. Observation of topological valley transport of sound in sonic crystals

    NASA Astrophysics Data System (ADS)

    Lu, Jiuyang; Qiu, Chunyin; Ye, Liping; Fan, Xiying; Ke, Manzhu; Zhang, Fan; Liu, Zhengyou

    2017-04-01

    The concept of valley pseudospin, labelling quantum states of energy extrema in momentum space, is attracting attention because of its potential as a new type of information carrier. Compared with the non-topological bulk valley transport, realized soon after predictions, topological valley transport in domain walls is extremely challenging owing to the inter-valley scattering inevitably induced by atomic-scale imperfections--but an electronic signature was recently observed in bilayer graphene. Here, we report the experimental observation of topological valley transport of sound in sonic crystals. The macroscopic nature of sonic crystals permits a flexible and accurate design of domain walls. In addition to a direct visualization of the valley-selective edge modes through spatial scanning of the sound field, reflection immunity is observed in sharply curved interfaces. The topologically protected interface transport of sound, strikingly different from that in traditional sound waveguides, may serve as the basis for designing devices with unconventional functions.

  15. Rocky Mountain Spotted Fever, Colombia

    PubMed Central

    Hidalgo, Marylin; Orejuela, Leonora; Fuya, Patricia; Carrillo, Pilar; Hernandez, Jorge; Parra, Edgar; Keng, Colette; Small, Melissa; Olano, Juan P.; Bouyer, Donald; Castaneda, Elizabeth; Walker, David

    2007-01-01

    We investigated 2 fatal cases of Rocky Mountain spotted fever that occurred in 2003 and 2004 near the same locality in Colombia where the disease was first reported in the 1930s. A retrospective serosurvey of febrile patients showed that >21% of the serum samples had antibodies against spotted fever group rickettsiae. PMID:18214179

  16. Enhanced valley splitting in monolayer WSe2 due to magnetic exchange field.

    PubMed

    Zhao, Chuan; Norden, Tenzin; Zhang, Peiyao; Zhao, Puqin; Cheng, Yingchun; Sun, Fan; Parry, James P; Taheri, Payam; Wang, Jieqiong; Yang, Yihang; Scrace, Thomas; Kang, Kaifei; Yang, Sen; Miao, Guo-Xing; Sabirianov, Renat; Kioseoglou, George; Huang, Wei; Petrou, Athos; Zeng, Hao

    2017-08-01

    Exploiting the valley degree of freedom to store and manipulate information provides a novel paradigm for future electronics. A monolayer transition-metal dichalcogenide (TMDC) with a broken inversion symmetry possesses two degenerate yet inequivalent valleys, which offers unique opportunities for valley control through the helicity of light. Lifting the valley degeneracy by Zeeman splitting has been demonstrated recently, which may enable valley control by a magnetic field. However, the realized valley splitting is modest (∼0.2 meV T -1 ). Here we show greatly enhanced valley spitting in monolayer WSe 2 , utilizing the interfacial magnetic exchange field (MEF) from a ferromagnetic EuS substrate. A valley splitting of 2.5 meV is demonstrated at 1 T by magnetoreflectance measurements and corresponds to an effective exchange field of ∼12 T. Moreover, the splitting follows the magnetization of EuS, a hallmark of the MEF. Utilizing the MEF of a magnetic insulator can induce magnetic order and valley and spin polarization in TMDCs, which may enable valleytronic and quantum-computing applications.

  17. Geophysical reconnaissance of Lemmon Valley, Washoe County, Nevada

    USGS Publications Warehouse

    Schaefer, Donald H.; Maurer, Douglas K.

    1981-01-01

    Rapid growth in the Lemmon Valley area, Nevada, during recent years has put increasing importance on knowledge of stored ground water for the valley. Data that would fill voids left by previous studies are depth to bedrock and depth to good-quality water beneath the two playas in the valley. Depths to bedrock calculated from a gravity survey in Lemmon Valley indicate that the western part of Lemmon Valley is considerably deeper than the eastern part. Maximum depth in the western part is about 2 ,600 feet below land surface. This depression approximately underlies the Silver Lake playa. A smaller, shallower depression with a maximum depth of about 1,500 feet below land surface exists about 2.5 miles north of the playa. The eastern area is considerably shallower. The maximum calculated depth to bedrock is about 1,000 feet below land surface, but the depth throughout most the eastern area is only about 400 feet below land surface. An electrical resistivity survey in Lemmon Valley consisting of 10 Schlumberger soundings was conducted around the playas. The maximum depth of poor-quality water (characterized by a resistivity less than 20 ohm-meters) differed considerably from place to place. Maximum depths of poor-quality water beneath the playa east of Stead varied from about 120 feet to almost 570 feet below land surface. At the Silver Lake playa, the maximum depths varied from about 40 feet in the west to 490 feet in the east. (USGS)

  18. Principal facts for gravity stations in the Elko, Steptoe Valley, Coyote Spring Valley, and Sheep Range areas, eastern and southern Nevada

    USGS Publications Warehouse

    Berger, D.L.; Schaefer, D.H.; Frick, E.A.

    1990-01-01

    Principal facts for 537 gravity stations in the carbonate-rock province of eastern and southern Nevada are tabulated and presented. The gravity data were collected in support of groundwater studies in several valleys. The study areas include the Elko area, northern Steptoe Valley, Coyote Spring Valley, and the western Sheep Range area. The data for each site include values for latitude, longitude, altitude, observed gravity, free- air anomaly, terrain correction, and Bouguer anomaly (calculated at a bedrock density of 2.67 g/cu cm. (USGS)

  19. Scaling the Morphology of Sapping and Pressurized Groundwater Experiments to Martian Valleys

    NASA Astrophysics Data System (ADS)

    Marra, W. A.; Kleinhans, M. G.

    2013-12-01

    Various valleys exist on Mars, which shows the former existence of fluvial activity and thus liquid water at the surface. Although these valleys show similarities with some valleys on Earth, many morphological features are unique for Mars or are very rare on Earth. Therefore, we lack knowledge about the formative processes of these enigmatic valleys. In this study, we explored possible groundwater scenarios for the formation of these valleys using flume experiments, as there are no pure Earth analogues for these systems. We aim to infer their formative processes from morphological properties. A series of flume experiments were carried out in a 4x6x1 m experimental setup, where we observed the valley formation as result from seeping groundwater by both local and distal groundwater sources and by pressurized groundwater release. Time-lapse imagery and DEMs of the experiments show the morphological development, associated processes, and landscape evolution. Indicators of the processes where we particularly looked at were changes in valley slope, cross-sectional shape, the relations between valley dimensions, and regional landscape properties as drainage density and valley size distributions. Hydrological modelling assists in scaling the observed experimental features to real-world systems. Additionally, we looked at valleys on Earth in the Atacama Desert, at Box canyon in Idaho, valleys around Kohala on Hawaii and Apalachicola bluffs in Florida to test the applicability of our methods to real-world systems. In the seeping groundwater valleys, valleys develop due to a combination of mass-wasting failures, mudflows and fluvial flow. The latter two processes are expressed in the final morphology by a break in slope. The mass wasting processes result in U-shaped valleys, which are more pronounced in distal groundwater cases. However, in real-world cases of similar shaped valleys, the cross-sectional shape seems strongly influenced by the strength of the material as well

  20. Malaria in gold-mining areas in Colombia

    PubMed Central

    Castellanos, Angélica; Chaparro-Narváez, Pablo; Morales-Plaza, Cristhian David; Alzate, Alberto; Padilla, Julio; Arévalo, Myriam; Herrera, Sócrates

    2016-01-01

    Gold-mining may play an important role in the maintenance of malaria worldwide. Gold-mining, mostly illegal, has significantly expanded in Colombia during the last decade in areas with limited health care and disease prevention. We report a descriptive study that was carried out to determine the malaria prevalence in gold-mining areas of Colombia, using data from the public health surveillance system (National Health Institute) during the period 2010-2013. Gold-mining was more prevalent in the departments of Antioquia, Córdoba, Bolívar, Chocó, Nariño, Cauca, and Valle, which contributed 89.3% (270,753 cases) of the national malaria incidence from 2010-2013 and 31.6% of malaria cases were from mining areas. Mining regions, such as El Bagre, Zaragoza, and Segovia, in Antioquia, Puerto Libertador and Montelíbano, in Córdoba, and Buenaventura, in Valle del Cauca, were the most endemic areas. The annual parasite index (API) correlated with gold production (R2 0.82, p < 0.0001); for every 100 kg of gold produced, the API increased by 0.54 cases per 1,000 inhabitants. Lack of malaria control activities, together with high migration and proliferation of mosquito breeding sites, contribute to malaria in gold-mining regions. Specific control activities must be introduced to control this significant source of malaria in Colombia. PMID:26814645

  1. Malaria in gold-mining areas in Colombia.

    PubMed

    Castellanos, Angélica; Chaparro-Narváez, Pablo; Morales-Plaza, Cristhian David; Alzate, Alberto; Padilla, Julio; Arévalo, Myriam; Herrera, Sócrates

    2016-01-01

    Gold-mining may play an important role in the maintenance of malaria worldwide. Gold-mining, mostly illegal, has significantly expanded in Colombia during the last decade in areas with limited health care and disease prevention. We report a descriptive study that was carried out to determine the malaria prevalence in gold-mining areas of Colombia, using data from the public health surveillance system (National Health Institute) during the period 2010-2013. Gold-mining was more prevalent in the departments of Antioquia, Córdoba, Bolívar, Chocó, Nariño, Cauca, and Valle, which contributed 89.3% (270,753 cases) of the national malaria incidence from 2010-2013 and 31.6% of malaria cases were from mining areas. Mining regions, such as El Bagre, Zaragoza, and Segovia, in Antioquia, Puerto Libertador and Montelíbano, in Córdoba, and Buenaventura, in Valle del Cauca, were the most endemic areas. The annual parasite index (API) correlated with gold production (R2 0.82, p < 0.0001); for every 100 kg of gold produced, the API increased by 0.54 cases per 1,000 inhabitants. Lack of malaria control activities, together with high migration and proliferation of mosquito breeding sites, contribute to malaria in gold-mining regions. Specific control activities must be introduced to control this significant source of malaria in Colombia.

  2. Genetic Structure of Anopheles (Nyssorhynchus) marajoara (Diptera: Culicidae) in Colombia

    DTIC Science & Technology

    2010-01-01

    South America . J Infect Dis 186: 999 – 1006 . 2. Mendoza M , Nicholls R , Olano V , Cortés L , 2000 . Situación de la malaria en ...Colombia . Manual de Manejo integral de la malaria. Instituto Nacional de Salud Ed . Bogotá, Columbia: Instituto Nacional de Salud . 3. Herrera...S , Suárez M , Sánchez G , Quiñones M , Herrera M , 1987 . Uso de la técnica inmunoradiometrica (IRMA) en Anopheles de Colombia para la

  3. MX Siting Investigation. Gravity Survey - Sevier Desert Valley, Utah.

    DTIC Science & Technology

    1981-01-24

    Cheyenne, Wyoming. DMAHTC reduces the data to Simple Bouguer Anomaly (see Section A1.4, Appendix Al.0). The Defense Mapping Agency Aerospace Center...Desert Valley, Utah ......... 2 2 Topographic Setting - Sevier Desert Valley, Utah . 3 LIST OF DRAWINGS Drawing Number 1 Complete Bouguer Anomaly...gravity stations were distributed throughout the valley at an approxi- mate interval of 1.4 miles (2.3 km). Drawing 1 is a Complete Bouguer Anomaly

  4. Lithologic controls on valley width and strath terrace formation

    NASA Astrophysics Data System (ADS)

    Schanz, Sarah A.; Montgomery, David R.

    2016-04-01

    Valley width and the degree of bedrock river terrace development vary with lithology in the Willapa and Nehalem river basins, Pacific Northwest, USA. Here, we present field-based evidence for the mechanisms by which lithology controls floodplain width and bedrock terrace formation in erosion-resistant and easily friable lithologies. We mapped valley surfaces in both basins, dated straths using radiocarbon, compared valley width versus drainage area for basalt and sedimentary bedrock valleys, and constructed slope-area plots. In the friable sedimentary bedrock, valleys are 2 to 3 times wider, host flights of strath terraces, and have concavity values near 1; whereas the erosion-resistant basalt bedrock forms narrow valleys with poorly developed, localized, or no bedrock terraces and a channel steepness index half that of the friable bedrock and an average channel concavity of about 0.5. The oldest dated strath terrace on the Willapa River, T2, was active for nearly 10,000 years, from 11,265 to 2862 calibrated years before present (cal YBP), whereas the youngest terrace, T1, is Anthropocene in age and recently abandoned. Incision rates derived from terrace ages average 0.32 mm y- 1 for T2 and 11.47 mm y- 1 for T1. Our results indicate bedrock weathering properties influence valley width through the creation of a dense fracture network in the friable bedrock that results in high rates of lateral erosion of exposed bedrock banks. Conversely, the erosion-resistant bedrock has concavity values more typical of detachment-limited streams, exhibits a sparse fracture network, and displays evidence for infrequent episodic block erosion and plucking. Lithology thereby plays a direct role on the rates of lateral erosion, influencing valley width and the potential for strath terrace planation and preservation.

  5. U.S. Support of Plan Colombia: Rethinking the Ends and Means

    DTIC Science & Technology

    2001-05-01

    to thrive as long as there are dark corners of the international systems where traditional sovereign controls are weak or non -existent. The illicit...security debate involving U.S. policy in Colombia and the implementation of Plan Colombia. DOUGLAS C. LOVELACE, JR. Director Strategic Studies...crime more efficiently through effective international cooperation, which includes the press, judicial systems, and government officials on a broad

  6. Are We Approaching the Real Defeat of the FARC in Colombia

    DTIC Science & Technology

    2009-03-01

    Democracia Asediada, Balance y perspectivas del conflicto armado en Colombia. (Bogota, Grupo Editorial Norma 2004). 64 46 Fundacion Seguridad y Democracia ...the armed forces in false accusations, and defending the rebels captured. 35 Eduardo Pizarro Leon gomez, “Una Democracia Asediada”: balance y...Colombia, la seguridad y la defense de las fronteras. (Bogota, November 2008),19. 47 Alfredo Rangel, Un vecindario inseguro , (Semana, November 13, 2008

  7. Valley-contrasting physics in all-dielectric photonic crystals: Orbital angular momentum and topological propagation

    NASA Astrophysics Data System (ADS)

    Chen, Xiao-Dong; Zhao, Fu-Li; Chen, Min; Dong, Jian-Wen

    2017-07-01

    The valley has been exploited as a binary degree of freedom to realize valley-selective Hall transport and circular dichroism in two-dimensional layered materials, in which valley-contrasting physics is indispensable in making the valley index an information carrier. In this Rapid Communication, we reveal valley-contrasting physics in all-dielectric valley photonic crystals. The link between the angular momentum of light and the valley state is discussed, and unidirectional excitation of the valley chiral bulk state is realized by sources carrying orbital angular momentum with proper chirality. Characterized by the nonzero valley Chern number, valley-dependent edge states and the resultant broadband robust transport is found in such an all-dielectric system. Our work has potential in the orbital angular momentum assisted light manipulation and the discovery of valley-protected topological states in nanophotonics and on-chip integration.

  8. Valley-polarized edge pseudomagnetoplasmons in graphene: A two-component hydrodynamic model

    NASA Astrophysics Data System (ADS)

    Zhang, Ya; Guo, Bin; Zhai, Feng; Jiang, Wei

    2018-03-01

    By means of a nonlinear two-component hydrodynamic model, we study the valley-polarized collective motion of electrons in a strained graphene sheet. The self-consistent numerical solution in real space indicates the existence of valley-polarized edge plasmons due to a strain-induced pseudomagnetic field. The valley polarization of the edge pseudomagnetoplasmon can occur in a specific valley, depending on the pseudomagnetic field and the electron density in equilibrium. A full valley polarization is achieved at the edge of the graphene sheet for a pseudomagnetic field of tens of Tesla, which is a realistic value in current experimental technologies.

  9. Orbital and Rover-based Exploration of Perseverance Valley, Endeavour Crater, Mars

    NASA Astrophysics Data System (ADS)

    Morgan, A. M.; Arvidson, R. E.; Duran Vinent, O.; Craddock, R. A.; Holo, S.; Gadal, C.; Blois, G.; Palucis, M. C.; Goudge, T. A.; Morgan, A. M.; Day, M.; Sullivan, R. J., Jr.; Umurhan, O. M.; Pähtz, T.; Birch, S.; Morgan, A. M.; Goudge, T. A.; Palucis, M. C.; Arvidson, R. E.; Duran Vinent, O.; Craddock, R. A.; Holo, S.; Blois, G.; Gadal, C.; Morgan, A. M.; Sullivan, R. J., Jr.; Day, M.; Arvidson, R. E.

    2017-12-01

    Perseverance Valley, based on orbital observations from the Mars Reconnaisance Orbiter HiRISE image data, is a 180 m long, 20 m wide anastomosing shallow channel system superimposed on the Cape Byron rim segment of the 22 km diameter Noachian-age Endeavour Crater on Mars. Several impact craters are superimposed on the valley system, indicating antiquity, although the valley's high degree of preservation indicates that it formed after significant regional-scale fluvial erosion and diffusive smoothing of Endeavour and its rim segments. The valley cuts into the inner, eastern rim on a 10˚ to 15˚ slope, and starts at a local low area on the rim crest. A set of shallow channels, some lined with perimeter rocks, extends from the west to meet the entrance to the valley. The western rim tilts to the west 0.8˚ and thus the channels tilt away from the valley entrance. The Mars Rover Opportunity has explored the western shallow channels leading up to the entrance to the valley. As of this writing Opportunity is located on the southern side of the valley entrance, with the Athena Science Team waiting until after solar conjunction to command the rover to descend into the valley to search for geomorphic and sedimentologic evidence related to valley formation. Wind erosion along radial fractures extending into and down Cape Byron is a possibility. Debris flows are also under consideration, perhaps enabled by melting ice at the rim crest. Dry avalanches are unlikely due to the low slopes. A fluvial origin is a strong contender based on models that show it is possible to have had a western catchment present when the Burns formation hydrated sulfates were being emplaced, followed by self-compaction of these sediments that tilted the western plains away from the rim crest. The key to testing among the various hypotheses for formation of the valley and shallow channels leading into the entrance will be the detailed stereo and multispectral imaging observations Opportunity will make

  10. Rural-Urban Migration in Colombia.

    ERIC Educational Resources Information Center

    Schultz, T. Paul

    The rural-urban migration pattern in Colombia during the last 25 years has resulted in a population increase in urban areas from 30 to 52 percent of the total population. This study explores the causes of internal migration. Migration rates are estimated for various groups in the population to clarify who migrates and to where. A model of…

  11. Sutter Buttes-the lone volcano in California's Great Valley

    USGS Publications Warehouse

    Hausback, Brain P.; Muffler, L.J. Patrick; Clynne, Michael A.

    2011-01-01

    The volcanic spires of the Sutter Buttes tower 2,000 feet above the farms and fields of California's Great Valley, just 50 miles north-northwest of Sacramento and 11 miles northwest of Yuba City. The only volcano within the valley, the Buttes consist of a central core of volcanic domes surrounded by a large apron of fragmental volcanic debris. Eruptions at the Sutter Buttes occurred in early Pleistocene time, 1.6 to 1.4 million years ago. The Sutter Buttes are not part of the Cascade Range of volcanoes to the north, but instead are related to the volcanoes in the Coast Ranges to the west in the vicinity of Clear Lake, Napa Valley, and Sonoma Valley.

  12. Results of global youth tobacco surveys in public schools in Bogotá, Colombia.

    PubMed

    Pardo, Constanza; Piñeros, Marion; Jones, Nathan R; Warren, Charles W

    2010-03-01

    The purpose of this paper is to use data from the Global Youth Tobacco Survey (GYTS) conducted in Bogotá, Colombia, in 2001 and 2007 to examine changes in tobacco use among youth 13-15 years of age. The current tobacco control effort in Bogotá will be accessed relative to Colombia ratifying the World Health Organization Framework Convention on Tobacco Control (WHO FCTC) in 2008. GYTS was implemented in public schools in Bogotá, Colombia, by the Colombian National Cancer Institute. Data were collected from students in classrooms using self-administered procedures. Between 2001 and 2007, ever having smoked cigarettes decreased along with exposure to secondhand smoke (SHS) at home, having an object with a tobacco logo on it, and having been offered free cigarettes by a tobacco company representative. Prevalence of current cigarette smoking did not change from 2001 to 2007 (32.9% and 29.9%). Exposure to pro-tobacco advertising increased, reaching 71.4%, and 73.4% respectively, in 2007. Having been taught about the harmful effects of tobacco use did not change over time. The government of Colombia ratified the WHO FCTC in 2008. However, Colombia has one of the highest levels of cigarette smoking among 13-15 year olds in the Region of the Americas. The tobacco control effort in Colombia has much work to do, including recognition that the levels of smoking among adolescents are already as high as those of adults. Future declines in tobacco use among adolescents in Bogotá will likely depend on development of a comprehensive tobacco control program.

  13. 27 CFR 9.66 - Russian River Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Russian River Valley. 9.66 Section 9.66 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.66 Russian River Valley. (a) Name. The name of the...

  14. 27 CFR 9.66 - Russian River Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Russian River Valley. 9.66 Section 9.66 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.66 Russian River Valley. (a) Name. The name of the...

  15. 27 CFR 9.66 - Russian River Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Russian River Valley. 9.66 Section 9.66 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.66 Russian River Valley. (a) Name. The name of the...

  16. 27 CFR 9.66 - Russian River Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Russian River Valley. 9.66 Section 9.66 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.66 Russian River Valley. (a) Name. The name of the...

  17. 27 CFR 9.64 - Dry Creek Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Dry Creek Valley. 9.64 Section 9.64 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.64 Dry Creek Valley. (a) Name. The name of the...

  18. 27 CFR 9.64 - Dry Creek Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Dry Creek Valley. 9.64 Section 9.64 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.64 Dry Creek Valley. (a) Name. The name of the...

  19. 27 CFR 9.64 - Dry Creek Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Dry Creek Valley. 9.64 Section 9.64 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.64 Dry Creek Valley. (a) Name. The name of the...

  20. 27 CFR 9.66 - Russian River Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Russian River Valley. 9.66 Section 9.66 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.66 Russian River Valley. (a) Name. The name of the...

  1. 27 CFR 9.64 - Dry Creek Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Dry Creek Valley. 9.64 Section 9.64 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.64 Dry Creek Valley. (a) Name. The name of the...

  2. 27 CFR 9.64 - Dry Creek Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Dry Creek Valley. 9.64 Section 9.64 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.64 Dry Creek Valley. (a) Name. The name of the...

  3. 27 CFR 9.214 - Haw River Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Haw River Valley. 9.214... River Valley. (a) Name. The name of the viticultural area described in this section is “Haw River Valley”. For purposes of part 4 of this chapter, “Haw River Valley” and “Haw River” are terms of viticultural...

  4. Gate-tunable valley-spin filtering in silicene with magnetic barrier

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wu, X. Q., E-mail: xianqiangzhe@126.com; Meng, H.

    2015-05-28

    We theoretically study the valley- and spin-resolved scattering through magnetic barrier in a one layer thick silicene, using the mode-matching method for the Dirac equation. We show that the spin-valley filtering effect can be achieved and can also be tuned completely through both a top and bottom gate. Moreover, when reversing the sign of the staggered potential, we find the direction of the valley polarization is switched while the direction of spin polarization is unchanged. These results can provide some meaningful information to design valley valve residing on silicene.

  5. VALDRIFT 1.0: A valley atmospheric dispersion model with deposition

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Allwine, K.J.; Bian, X.; Whiteman, C.D.

    1995-05-01

    VALDRIFT version 1.0 is an atmospheric transport and diffusion model for use in well-defined mountain valleys. It is designed to determine the extent of ddft from aedal pesticide spraying activities, but can also be applied to estimate the transport and diffusion of various air pollutants in valleys. The model is phenomenological -- that is, the dominant meteorological processes goveming the behavior of the valley atmosphere are formulated explicitly in the model, albeit in a highly parameterized fashion. The key meteorological processes treated are: (1) nonsteady and nonhomogeneous along-valley winds and turbulent diffusivities, (2) convective boundary layer growth, (3) inversion descent,more » (4) noctumal temperature inversion breakup, and (5) subsidence. The model is applicable under relatively cloud-free, undisturbed synoptic conditions and is configured to operate through one diumal cycle for a single valley. The inputs required are the valley topographical characteristics, pesticide release rate as a function of time and space, along-valley wind speed as a function of time and space, temperature inversion characteristics at sunrise, and sensible heat flux as a function of time following sunrise. Default values are provided for certain inputs in the absence of detailed observations. The outputs are three-dimensional air concentration and ground-level deposition fields as a function of time.« less

  6. The vertical structure of the circulation and dynamics in Hudson Shelf Valley

    USGS Publications Warehouse

    Lentz, Steven J.; Butman, Bradford; Harris, Courtney K.

    2014-01-01

    Hudson Shelf Valley is a 20–30 m deep, 5–10 km wide v-shaped submarine valley that extends across the Middle Atlantic Bight continental shelf. The valley provides a conduit for cross-shelf exchange via along-valley currents of 0.5 m s−1 or more. Current profile, pressure, and density observations collected during the winter of 1999–2000 are used to examine the vertical structure and dynamics of the flow. Near-bottom along-valley currents having times scales of a few days are driven by cross-shelf pressure gradients setup by wind stresses, with eastward (westward) winds driving onshore (offshore) flow within the valley. The along-valley momentum balance in the bottom boundary layer is predominantly between the pressure gradient and bottom stress because the valley bathymetry limits current veering. Above the bottom boundary layer, the flow veers toward an along-shelf (cross-valley) orientation and a geostrophic balance with some contribution from the wind stress (surface Ekman layer). The vertical structure and strength of the along-valley current depends on the magnitude and direction of the wind stress. During offshore flows driven by westward winds, the near-bottom stratification within the valley increases resulting in a thinner bottom boundary layer and weaker offshore currents. Conversely, during onshore flows driven by eastward winds the near-bottom stratification decreases resulting in a thicker bottom boundary layer and stronger onshore currents. Consequently, for wind stress magnitudes exceeding 0.1 N m−2, onshore along-valley transport associated with eastward wind stress exceeds the offshore transport associated with westward wind stress of the same magnitude.

  7. View From Within 'Perseverance Valley' on Mars

    NASA Image and Video Library

    2017-12-06

    This view from within "Perseverance Valley," on the inner slope of the western rim of Endurance Crater on Mars, includes wheel tracks from the Opportunity rover's descent of the valley. The Panoramic Camera (Pancam) on Opportunity's mast took the component images of the scene during the period Sept. 4 through Oct. 6, 2017, corresponding to sols (Martian days) 4840 through 4871 of the rover's work on Mars. Perseverance Valley is a system of shallow troughs descending eastward about the length of two football fields from the crest of the crater rim to the floor of the crater. This panorama spans from northeast on the left to northwest on the right, including portions of the crater floor (eastward) in the left half and of the rim (westward) in the right half. Opportunity began descending Perseverance Valley in mid-2017 (see map) as part of an investigation into how the valley formed. Rover wheel tracks are darker brown, between two patches of bright bedrock, receding toward the horizon in the right half of the scene. This view combines multiple images taken through three different Pancam filters. The selected filters admit light centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). The three color bands are combined here to show approximately true color. A map and high-resolution TIFF file is available at https://photojournal.jpl.nasa.gov/catalog/PIA22074

  8. The Breakup of Temperature Inversions In Steep Valleys

    NASA Astrophysics Data System (ADS)

    Colette, A.; Street, R.

    The purpose of this research is to model and provide a better understanding of tem- perature inversions breakup in steep valleys. The Advanced Regional Prediction Sys- tem (ARPS), a three-dimensional, compressible, and non-hydrostatic modeling tool developed by the Center for Analysis and Prediction of Storms at the University of Oklahoma was used. Many field studies indicate that the evolution of the convective and inversion layers are strongly dependant on the surrounding topography. In relatively open valleys, the convective boundary layer usually grows from the bottom of the valley while in steeper cases, the upslope morning winds affects the dynamic of the mixing layer resulting in the destruction of the inversion from its bottom and its top (see Whiteman 1980). ARPS allows one to perform accurate simulation of such situations. First, written in terrain following coordinates, it handles steep topographies; then its extensive radi- ation and surface flux packages provide a good treatment of land related processes. Moreover, ARPS accounts for the incidence angle of sunrays, differencing the ex- posed and non-exposed mountain slopes. However, it neglects the topographic shade which can delay the sunrise of a hour or more in steep valleys. A new subroutine described by Colette etal. 2002 is thus used to compute the projected shade on the surrounding topography. Simulations of temperature inversion breakup for various two-dimensional valleys are presented. The time scale of evolution of the mixing layer is in good agreement with field studies and, as expected, the convective boundary layer shows an asymmetry between east and west facing slopes. The different patterns of inversion breakup doc- umented by Whiteman are also reproduced. These simulations of idealized cases give a better understanding of inversion breakup in steep valleys. Our code is now being applied to a real case: the study of a peculiar wind, la Ora del Garda, caused by the interaction between a

  9. Ground water in the San Joaquin Valley, California

    USGS Publications Warehouse

    Kunkel, Fred; Hofman, Walter

    1966-01-01

    Ladies and gentlemen, it is a pleasure to be invited to attend this Irrigation Institute conference and to describe the Geological Survey's program of ground-water studies in the San Joaquin Valley. The U.S. Geological Survey has been making water-resources studies in cooperation with the State of California and other agencies in California for more than 70 years. Three of the earliest Geological Survey Water-Supply Papers--numbers 17, 18, and 19--published in 1898 and 1899, describe "Irrigation near Bakersfield," "Irrigation near Fresno," and "Irrigation near Merced." However, the first Survey report on ground-water occurrence in the San Joaquin Valley was "Ground Water in the San Joaquin Valley," by Mendenhall and others. The fieldwork was done from 1905 to 1910, and the report was published in 1916 as U.S. Geological Survey Water-Supply Paper 398.The current series of ground-water studies in the San Joaquin Valley was begun in 1952 as part of the California Department of Water Resources-U.S. Geological Survey cooperative water-resources program. The first report of this series is Geological Survey Water-Supply Paper 1469, "Ground-Water Conditions and Storage Capacity in the San Joaquin Valley." Other reports are Water-Supply Paper 1618, "Use of Ground-Water Reservoirs for Storage of Surface Water in the San Joaquin Valley;" Water-Supply Paper 1656, "Geology and Ground-Water Features of the Edison-Maricopa Area;" Water-Supply Paper 1360-G, "Ground- Water Conditions in the Mendota-Huron Area;" Water-Supply Paper 1457, "Ground-Water Conditions in the Avenal-McKittrick Area;" and an open-file report, "Geology, Hydrology, and Quality of Water in the Terra Bella-Lost Hills Area."In addition to the preceding published reports, ground-water studies currently are being made of the Kern Fan area, the Hanford- Visalia area, the Fresno area, the Merced area, and of the clays of Tulare Lake. Also, detailed studies of both shallow and deep subsidence in the southern part of

  10. Advanced seismic imaging of overdeepened alpine valleys

    NASA Astrophysics Data System (ADS)

    Burschil, Thomas; Buness, Hermann; Tanner, David; Gabriel, Gerald; Krawczyk, Charlotte M.

    2017-04-01

    Major European alpine valleys and basins are densely populated areas with infrastructure of international importance. To protect the environment by, e.g., geohazard assessment or groundwater estimation, understanding of the geological structure of these valleys is essential. The shape and deposits of a valley can clarify its genesis and allows a prediction of behaviour in future glaciations. The term "overdeepened" refers to valleys and basins, in which pressurized melt-water under the glacier erodes the valley below the fluvial level. Most overdeepened valleys or basins were thus refilled during the ice melt or remain in the form of lakes. The ICDP-project Drilling Overdeepened Alpine Valleys (DOVE) intends to correlate the sedimentary succession from boreholes between valleys in the entire alpine range. Hereby, seismic exploration is essential to predict the most promising well path and drilling site. In a first step, this DFG-funded project investigates the benefit of multi-component techniques for seismic imaging. At two test sites, the Tannwald Basin and the Lienz Basin, the Leibniz Institute for Applied Geophysics acquired P-wave reflection profiles to gain structural and facies information. Built on the P-wave information, several S-wave reflection profiles were acquired in the pure SH-wave domain as well as 6-C reflection profiles using a horizontal S-wave source in inline and crossline excitation and 3-C receivers. Five P-wave sections reveal the structure of the Tannwald Basin, which is a distal branch basin of the Rhine Glacier. Strong reflections mark the base of the basin, which has a maximum depth of 240 metres. Internal structures and facies vary strongly and spatially, but allow a seismic facies characterization. We distinguish lacustrine, glacio-fluvial, and deltaic deposits, which make up the fill of the Tannwald Basin. Elements of the SH-wave and 6-C seismic imaging correlate with major structures in the P-wave image, but vary in detail. Based on

  11. Sociocultural and Economic Dimensions of Rift Valley Fever

    PubMed Central

    Muga, Geoffrey Otieno; Onyango-Ouma, Washington; Sang, Rosemary; Affognon, Hippolyte

    2015-01-01

    Health researchers have advocated for a cross-disciplinary approach to the study and prevention of infectious zoonotic diseases, such as Rift Valley Fever. It is believed that this approach can help bring out the social determinants and effects of the zoonotic diseases for the design of appropriate interventions and public health policy. A comprehensive literature review using a systematic search strategy was undertaken to explore the sociocultural and economic factors that influence the transmission and spread of Rift Valley Fever. Although the findings reveal a paucity of social research on Rift Valley Fever, they suggest that livestock sacrificial rituals, food preparation and consumption practices, gender roles, and inadequate resource base for public institutions are the key factors that influence the transmission. It is concluded that there is need for cross-disciplinary studies to increase the understanding of Rift Valley Fever and facilitate appropriate and timely response and mitigation measures. PMID:25688166

  12. 19. PIPELINE INTERSECTION AT THE MOUTH OF WAIKOLU VALLEY ON ...

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

    19. PIPELINE INTERSECTION AT THE MOUTH OF WAIKOLU VALLEY ON THE BEACH. VALVE AT RIGHT (WITH WRENCH NEARBY) OPENS TO FLUSH VALLEY SYSTEM OUT. VALVE AT LEFT CLOSES TO KEEP WATER FROM ENTERING SYSTEM ALONG THE PALI DURING REPAIRS. - Kalaupapa Water Supply System, Waikolu Valley to Kalaupapa Settlement, Island of Molokai, Kalaupapa, Kalawao County, HI

  13. Highlights of NASA/DOE photovoltaics market assessment visit to Colombia

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A NASA/DOE sponsored photovoltaic market assessment team composed of representatives of NASA-Lewis Research Center, DHR, Inc., and Associates in Rural Development, Inc. recently conducted a month-long study in Colombia (June 28 - July 23). The team contacted government officials and private sector representatives in Bogota and Cali, and visited rural development and agricultural sites in the departments of Cundinamarca, Caldas, Valle, and chada to determine the potential market for American photovoltaic products in the Colombia agricultural and rural sectors.

  14. Source regions and water release mechanisms of Martian Valley Networks

    NASA Astrophysics Data System (ADS)

    Jaumann, R.; Reiss, D.; Sander, T.; Gwinner, K.; Roatsch, T.; Matz, K.-D.; Hauber, E.; Mertens, V.; Hoffmann, H.; Neukum, G.; HRSC Co-Investigator Team

    Martian valley networks have been cited as the best evidence that Mars maintained flow of liquid water across the surface. Although internal structures associated with a fluvial origin within valleys like inner channels, terraces, slip-off and undercut slopes are extremely rare on Mars (Carr and Malin, 2000) such features can be identified in high-resolution imagery (e.g. Malin and Edgett, 2001; Jaumann et al., 2005). However, besides internal features the source regions are an important indicator for the flow processes in Martian valleys because they define the drainage area and thus constrain the amount of available water for eroding the valley network. Furthermore, the morphology of the source regions and their topographic characteristics provide information about the origin of the water. On Mars valley networks are thought to be formed by retreating erosion where the water is supplied from the sub-surface. However, the mechanisms that are responsible for the release of ground water are poorly understood. The three dimensional highly resolved data of the High Resolution Stereo Camera (HRSC) on the Mars Express Mission (Neukum et al., 2004) allow the detailed examination of valley network source regions. A valley network in the western Lybia Montes region valley between 1.4°N to 3.5°N and 81.6°E to 82.5°E originates at a highland mountain region and drains down to Isidis Planitia over a distance of 400 km. Most of its distance the valley exhibits an interior channel that allows to constraint discharge and erosion budgets (Jaumann, et al., 2005). The valley was formed in the Noachian/Hesperian between 3.7 and 3.3 billion years. However, discharge and erosion budgets restrict the erosion time to a few million years in total, indicating single events rather than continuous flow over long periods. The source region of the valley is covered by a series of lava flows. Even the upstream part of the valley is covered by lava flows that cover the interior channel

  15. Valley-spin filtering through a nonmagnetic resonant tunneling structure in silicene

    NASA Astrophysics Data System (ADS)

    Wu, Xiuqiang; Meng, Hao; Zhang, Haiyang; Bai, Yujie; Xu, Xing

    2018-07-01

    We theoretically investigate how a silecene-based nonmagnetic resonant-tunneling structure, i.e. a double electrostatic potential structure, can be tailored to generate valley- and spin-polarized filtering by using the scattering matrix method. This method allows us to find simple analytical expressions for the scattering amplitudes. It is found that the transmissions of electrons from opposite spin and valley show exactly opposite behaviors, leading to valley and spin filtering in a wide range of transmission directions. These directional-dependent valley-spin polarization behaviors can be used to select preferential directions along which the valley-spin polarization of an initially unpolarized carrier can be strongly enhanced. We also find that this phenomenon arises from the combinations of the coherent effect, electrostatic potential and external electric field. Especially when the direction of the external electric field is changed, the spin filtering properties are contained, while the valley filtering properties can be switched. In addition, the filtering behaviors can be conveniently controlled by electrical gating. Therefore, the results can offer an all-electric method to construct a valley-spin filter in silicene.

  16. Results of Global Youth Tobacco Surveys in Public Schools in Bogota, Colombia

    ERIC Educational Resources Information Center

    Pardo, Constanza; Pineros, Marion; Jones, Nathan R.; Warren, Charles W.

    2010-01-01

    Background: The purpose of this paper is to use data from the Global Youth Tobacco Survey (GYTS) conducted in Bogota, Colombia, in 2001 and 2007 to examine changes in tobacco use among youth 13-15 years of age. The current tobacco control effort in Bogota will be accessed relative to Colombia ratifying the World Health Organization Framework…

  17. Fitness-valley crossing with generalized parent-offspring transmission.

    PubMed

    Osmond, Matthew M; Otto, Sarah P

    2015-11-01

    Simple and ubiquitous gene interactions create rugged fitness landscapes composed of coadapted gene complexes separated by "valleys" of low fitness. Crossing such fitness valleys allows a population to escape suboptimal local fitness peaks to become better adapted. This is the premise of Sewall Wright's shifting balance process. Here we generalize the theory of fitness-valley crossing in the two-locus, bi-allelic case by allowing bias in parent-offspring transmission. This generalization extends the existing mathematical framework to genetic systems with segregation distortion and uniparental inheritance. Our results are also flexible enough to provide insight into shifts between alternate stable states in cultural systems with "transmission valleys". Using a semi-deterministic analysis and a stochastic diffusion approximation, we focus on the limiting step in valley crossing: the first appearance of the genotype on the new fitness peak whose lineage will eventually fix. We then apply our results to specific cases of segregation distortion, uniparental inheritance, and cultural transmission. Segregation distortion favouring mutant alleles facilitates crossing most when recombination and mutation are rare, i.e., scenarios where crossing is otherwise unlikely. Interactions with more mutable genes (e.g., uniparental inherited cytoplasmic elements) substantially reduce crossing times. Despite component traits being passed on poorly in the previous cultural background, small advantages in the transmission of a new combination of cultural traits can greatly facilitate a cultural transition. While peak shifts are unlikely under many of the common assumptions of population genetic theory, relaxing some of these assumptions can promote fitness-valley crossing. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Hydrology of the San Luis Valley, south-central Colorado

    USGS Publications Warehouse

    Emery, P.A.; Boettcher, A.J.; Snipes, R.J.; Mcintyre, H.J.

    1969-01-01

    An investigation of the water resources of the Colorado part of the San Luis Valley was begun in 1966 by the U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board. (See index map, fig. 1). The purpose of the investigation is to provide information for planning and implementing improved water-development and management practices. The major water problems in the San Luis Valley include (1) waterlogging, (2) waste of water by nonbeneficial evapotranspiration, (3) deterioration of ground-water chemical quality, and (4) failure of Colorado to deliver water to New Mexico and Texas in accordance with the Rio Grande Compact. This report describes the hydrologic environment, extent of water-resource development, and some of the problems related to that development. Information presented is based on data collected from 1966 to 1968 and on previous studies. Subsequent reports are planned as the investigation progresses. The San Luis Valley extends about 100 miles from Poncha Pass near the northeast corner of Saguache County, Colo., to a point about 16 miles south of the Colorado-New Mexico State line. The total area is 3,125 square miles, of which about 3,000 are in Colorado. The valley is nearly flat except for the San Luis Hills and a few other small areas. The Colorado part of the San Luis Valley, which is described in this report, has an average altitude of about 7,700 feet. Bounding the valley on the west are the San Juan Mountains and on the east the Sangre de Cristo Mountains. Most of the valley floor is bordered by alluvial fans deposited by streams originating in the mountains, the most extensive being the Rio Grande fan (see block diagram, fig. 2 in pocket). Most of the streamflow is derived from snowmelt from 4,700 square miles of watershed in the surrounding mountains. The northern half of the San Luis Valley is internally drained and is referred to as the closed basin. The lowest part of this area is known locally as the "sump." The

  19. Re-Imagining Teacher Professional Development and Citizenship Education: Lessons for Import from Colombia

    ERIC Educational Resources Information Center

    Noonan, James M.

    2010-01-01

    This paper examines the role of teachers in the implementation of citizenship education in Colombia. Consistent with its highly-decentralized school system, Colombia's National Program of Citizenship Competencies was developed with the participation of many local, national, and international partners. Among the most involved and most critical…

  20. Ozone Laminae and Their Entrainment Into a Valley Boundary Layer, as Observed From a Mountaintop Monitoring Station, Ozonesondes, and Aircraft Over California's San Joaquin Valley

    NASA Astrophysics Data System (ADS)

    Faloona, I. C.; Conley, S. A.; Caputi, D.; Trousdell, J.; Chiao, S.; Eiserloh, A. J., Jr.; Clark, J.; Iraci, L. T.; Yates, E. L.; Marrero, J. E.; Ryoo, J. M.; McNamara, M. E.

    2016-12-01

    The San Joaquin Valley of California is wide ( 75 km) and long ( 400 km), and is situated under strong atmospheric subsidence due, in part, to the proximity of the midlatitude anticyclone of the Pacific High. The capping effect of this subsidence is especially prominent during the warm season when ground level ozone is a serious air quality concern across the region. While relatively clean marine boundary layer air is primarily funneled into the valley below the strong subsidence inversion at significant gaps in the upwind Coast Range mountains, airflow aloft also spills over these barriers and mixes into the valley from above. Because this transmountain flow occurs under the influence of synoptic subsidence it tends to present discrete, laminar sheets of differing air composition above the valley boundary layer. Meanwhile, although the boundary layers tend to remain shallow due to the prevailing subsidence, orographic and anabatic venting of valley boundary layer air around the basin whips up a complex admixture of regional air masses into a "buffer layer" just above the boundary layer (zi) and below the lower free troposphere. We present scalar data of widely varying lifetimes including ozone, methane, NOx, and thermodynamic observations from upwind and within the San Joaquin Valley to better explain this layering and its subsequent erosion into the valley boundary layer via entrainment. Data collected at a mountaintop monitoring station on Chews Ridge in the Coast Range, by coastal ozonesondes, and aircraft are analyzed to document the dynamic layering processes around the complex terrain surrounding the valley. Particular emphasis will be made on observational methods whereby distal ozone can be distinguished from the regional ozone to better understand the influence of exogenous sources on air quality in the valley.

  1. Hypocenter for the 1979 Imperial Valley Earthquake

    USGS Publications Warehouse

    Archuleta, Ralph J.

    1982-01-01

    Using P-and S-wave arrival times with the laterally varying P-wave velocity structure derived from analysis of a refraction survey of the Imperial Valley, a hypocenter is ascertained for the October 15, 1979, Imperial Valley earthquake: Latitude 32° 39.50′N, Longitude 115° 19.80′W, Depth 8.0 km, Time 23:16:54.40 GMT.

  2. Scale insects (Hemiptera: Coccomorpha) on sugarcane in Colombia, with description of a new species of Tillancoccus Ben-Dov (Coccidae).

    PubMed

    Caballero, Alejandro; Ramos-Portilla, Andrea Amalia; Kondo, Takumasa

    2017-05-02

    Herein we describe a new species, Tillancoccus koreguajae Caballero & Ramos, sp. n. (Hemiptera: Coccidae) from Colombia collected on sugarcane. Pinnaspis strachani (Cooley) is also recorded on sugarcane for the first time worldwide. An updated list of seven species of Coccomorpha on sugarcane in Colombia is provided, including information on its distribution, biology, and mutualistic ants for each species. Seven species of scale insects (Hemiptera: Coccomorpha) have been recorded previously on sugarcane, Saccharum officinarum L. (Poaceae) in Colombia: Pseudococcidae: Dysmicoccus boninsis (Kuwana), D. brevipes (Cockerell), Pseudococcus calceolariae (Maskell), Saccharicoccus sacchari (Cockerell); Coccidae: Pulvinaria elongata Newstead; Diaspididae: Duplachionaspis divergens (Green) and Serenaspis minima (Maskell). However, the record of S. minima in Colombia is considered doubtful as there are no voucher specimens from Colombia and because the distribution of this species is currently limited to the Australasian region. Pseudococcus calceolariae is present in Colombia but its record on sugarcane is also doubtful. A taxonomic key for the identification of scale insects on sugarcane in Colombia is provided.

  3. Moisture origin and transport processes in Colombia, northern South America

    NASA Astrophysics Data System (ADS)

    Hoyos, I.; Dominguez, F.; Cañón-Barriga, J.; Martínez, J. A.; Nieto, R.; Gimeno, L.; Dirmeyer, P. A.

    2018-02-01

    We assess the spatial structure of moisture flux divergence, regional moisture sources and transport processes over Colombia, in northern South America. Using three independent methods the dynamic recycling model (DRM), FLEXPART and the Quasi-isentropic back-trajectory (QIBT) models we quantify the moisture sources that contribute to precipitation over the region. We find that moisture from the Atlantic Ocean and terrestrial recycling are the most important sources of moisture for Colombia, highlighting the importance of the Orinoco and Amazon basins as regional providers of atmospheric moisture. The results show the influence of long-range cross-equatorial flow from the Atlantic Ocean into the target region and the role of the study area as a passage of moisture into South America. We also describe the seasonal moisture transport mechanisms of the well-known low-level westerly and Caribbean jets that originate in the Pacific Ocean and Caribbean Sea, respectively. We find that these dynamical systems play an important role in the convergence of moisture over western Colombia.

  4. A new Proposal to Mexico Valley Zonification

    NASA Astrophysics Data System (ADS)

    Flores-Estrella, H. C.; Yussim, S.; Lomnitz, C.

    2004-12-01

    The effects of the Michoacan earthquake (19th September, 1985, Mw 8.1) in Mexico City caused a significant change in the political, social and scientific history, as it was considered the worst seismic disaster ever lived in Mexico. Since then, numerous efforts have been made to understand and determine the parameters that caused the special features registered. One of these efforts had began on 1960 with the work by Marsal and Masari, who published the Mexico Valley seismological and geotechnical zonification (1969), based on gravimetric and shallow borehole data. In this work, we present a revision of the studies that proposed the zonification, a description of the valley geology, and basing on it we propose a new zonification for Mexico Valley.

  5. Hybrid spin and valley quantum computing with singlet-triplet qubits.

    PubMed

    Rohling, Niklas; Russ, Maximilian; Burkard, Guido

    2014-10-24

    The valley degree of freedom in the electronic band structure of silicon, graphene, and other materials is often considered to be an obstacle for quantum computing (QC) based on electron spins in quantum dots. Here we show that control over the valley state opens new possibilities for quantum information processing. Combining qubits encoded in the singlet-triplet subspace of spin and valley states allows for universal QC using a universal two-qubit gate directly provided by the exchange interaction. We show how spin and valley qubits can be separated in order to allow for single-qubit rotations.

  6. M’zab Valley, Algeria

    NASA Image and Video Library

    2017-12-08

    NASA image acquired Feb. 9, 2011 Less than 5 percent of Algeria’s land surface is suitable for growing crops, and most precipitation falls on the Atlas Mountains along the coast. Inland, dust-laden winds blow over rocky plains and sand seas. However, in north central Algeria—off the tip of Grand Erg Occidental and about 450 kilometers (280 miles) south of Algiers—lies a serpentine stretch of vegetation. It is the M’zab Valley, filled with palm groves and dotted with centuries-old settlements. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite captured this image of M’zab Valley on February 9, 2011. ASTER combines infrared, red, and green wavelengths of light. Bare rock ranges in color from beige to peach. Buildings and paved surfaces appear gray. Vegetation is red, and brighter shades of red indicate more robust vegetation. This oasis results from water that is otherwise in short supply in the Sahara Desert, thanks to the valley’s approximately 3,000 wells. Chemical analysis of Algerian aquifers, as well studies of topography in Algeria and Tunisia, suggest this region experienced a cooler climate in the late Pleistocene, and potentially heavy monsoon rains earlier in the Holocene. The M’zab region shows evidence of meandering rivers and pinnate drainage patterns. The vegetation lining M’zab Valley highlights this old river valley’s contours. Cool summer temperatures and monsoon rains had long since retreated from the region by eleventh century, but this valley nevertheless supported the establishment of multiple fortified settlements, or ksours. Between 1012 A.D. and 1350 A.D., locals established the ksours of El-Atteuf, Bounoura, Melika, Ghardaïa, and Beni-Isguen. Collectively these cities are now a United Nations Educational, Scientific, and Cultural Organization (UNESCO) World Heritage site. NASA Earth Observatory image by Robert Simmon and Jesse Allen, using data from the GSFC

  7. Geospatial-temporal distribution of Tegumentary Leishmaniasis in Colombia (2007–2016)

    PubMed Central

    Herrera, Giovanny; Pradilla, Iván; Vera, Mauricio

    2018-01-01

    Background Tegumentary Leishmaniasis (TL) is a neglected disease with worldwide distribution and considered a public health problem, especially in Latin America. In Colombia, the governmental epidemiological surveillance system (SIVIGILA) is responsible for collecting information on the presentation of cases of TL from each of the municipalities and departments. In absence of a study compiling and analyzing currently available metadata of TL in Colombia, this study describes the geospatial-temporal distribution of TL and identifies the regions of the country on which prevention measures should be established in order to control the disease. Methodology/Principal findings This is an exploratory descriptive analysis of the distribution of TL in Colombia. Information was collected on new cases of the disease during the years 2007–2016 from the Colombian reporting system (SIVIGILA). Incidence calculations were made based on population estimates by departments and biogeographical regions. Time evolution is shown in biennial maps. A 10-year series was analyzed, showing that the Amazon region is the most affected in terms of incidence, while the Andean region has the highest number of cases with a high variability among the departments that make it up. In those departments where there is a greater reported diversity of vector species, a large number of cases was observed. Conclusions/Significance Transmission dynamics of TL in Colombia in the past 10 years have been variable, with a greater concentration of cases in the central and southern departments. The present study contributes to improve the understanding of the patterns of distribution of TL in Colombia and can be a basis for future studies of impact evaluation of Health policies in the country and the region. PMID:29624582

  8. Current status of rift valley fever vaccine development

    USDA-ARS?s Scientific Manuscript database

    Rift Valley fever (RVF) is a mosquito-borne zoonotic disease that presents substantial threat to human and public health. It is caused by Rift Valley fever phlebovirus (RVFV), which belongs to the genus Phlebovirus and the family Pheuniviridae within the order Bunyavirales. The wide distribution of ...

  9. Hydrological responses to channelization and the formation of valley plugs and shoals

    USGS Publications Warehouse

    Pierce, Aaron R.; King, Sammy L.

    2017-01-01

    Rehabilitation of floodplain systems focuses on restoring interactions between the fluvial system and floodplain, however, there is a paucity of information on the effects of valley plugs and shoals on floodplain hydrological processes. We investigated hydrologic regimes in floodplains at three valley plug sites, two shoal sites, and three unchannelized sites. Valley plug sites had altered surface and sub-surface hydrology relative to unchannelized sites, while only sub-surface hydrology was affected at shoal sites. Some of the changes were unexpected, such as reduced flood duration and flood depth in floodplains associated with valley plugs. Our results emphasize the variability associated with hydrologic processes around valley plugs and our rudimentary understanding of the effects associated with these geomorphic features. Water table levels were lower at valley plug sites compared to unchannelized sites, however, valley plug sites had a greater proportion of days when water table inundation was above mean root collar depth than both shoal and unchannelized sites as a result of lower root collar depths and higher deposition rates. This study has provided evidence that valley plugs can affect both surface and sub-surface hydrology in different ways than previously thought and illustrates the variability in hydrological responses to valley plug formation.

  10. Observation of Exciton-Exciton Interaction Mediated Valley Depolarization in Monolayer MoSe2.

    PubMed

    Mahmood, Fahad; Alpichshev, Zhanybek; Lee, Yi-Hsien; Kong, Jing; Gedik, Nuh

    2018-01-10

    The valley pseudospin in monolayer transition metal dichalcogenides (TMDs) has been proposed as a new way to manipulate information in various optoelectronic devices. This relies on a large valley polarization that remains stable over long time scales (hundreds of nanoseconds). However, time-resolved measurements report valley lifetimes of only a few picoseconds. This has been attributed to mechanisms such as phonon-mediated intervalley scattering and a precession of the valley pseudospin through electron-hole exchange. Here we use transient spin grating to directly measure the valley depolarization lifetime in monolayer MoSe 2 . We find a fast valley decay rate that scales linearly with the excitation density at different temperatures. This establishes the presence of strong exciton-exciton Coulomb exchange interactions enhancing the valley depolarization. Our work highlights the microscopic processes inhibiting the efficient use of the exciton valley pseudospin in monolayer TMDs.

  11. Sociocultural and economic dimensions of Rift Valley fever.

    PubMed

    Muga, Geoffrey Otieno; Onyango-Ouma, Washington; Sang, Rosemary; Affognon, Hippolyte

    2015-04-01

    Health researchers have advocated for a cross-disciplinary approach to the study and prevention of infectious zoonotic diseases, such as Rift Valley Fever. It is believed that this approach can help bring out the social determinants and effects of the zoonotic diseases for the design of appropriate interventions and public health policy. A comprehensive literature review using a systematic search strategy was undertaken to explore the sociocultural and economic factors that influence the transmission and spread of Rift Valley Fever. Although the findings reveal a paucity of social research on Rift Valley Fever, they suggest that livestock sacrificial rituals, food preparation and consumption practices, gender roles, and inadequate resource base for public institutions are the key factors that influence the transmission. It is concluded that there is need for cross-disciplinary studies to increase the understanding of Rift Valley Fever and facilitate appropriate and timely response and mitigation measures. © The American Society of Tropical Medicine and Hygiene.

  12. Evidence for gap flows in the Birch Creek Valley, Idaho

    Treesearch

    D. Finn; B. Reese; B. Butler; N. Wagenbrenner; K. L. Clawson; J. Rich; E. Russell; Z. Gao; H. Liu

    2016-01-01

    A field study was conducted of flows in the Birch Creek Valley in eastern Idaho. There is a distinct topographic constriction in the Birch Creek Valley that creates two subbasins: an upper and lower valley. The data were classified into one of three groups based on synoptic influence (weak/absent, high wind speeds, and other evidence of synoptic influence). Gap flows...

  13. Castro Valley High School's Solar Panels

    NASA Astrophysics Data System (ADS)

    Lew, A.; Ham, S.; Shin, Y.; Yang, W.; Lam, J.

    2014-12-01

    Solar panels are photovoltaic cells that are designed to convert the sun's kinetic energy to generate usable energy in the form of electricity. Castro Valley High School has tried to offset the cost of electricity by installing solar panels, costing the district approximately 3.29 million dollars, but have been installed incorrectly and are not operating at peak efficency. By using trigonometry we deduced that Castro Valley High School's south facing solar panels were at an incline of 10o and that the east and west facing solar panels are at an incline of 5o. By taking the averages of the optimum angles for the months of September through May, roughly when school is in session, we found that the optimum angle for south facing solar panels should be roughly 46o. This shows that Castro Valley High School has not used it's budget to its full potential due to the fact that the solar panels were haphazardly installed.

  14. Economic Costs of Chikungunya Virus in Colombia.

    PubMed

    Alvis-Zakzuk, Nelson J; Díaz-Jiménez, Diana; Castillo-Rodríguez, Liliana; Castañeda-Orjuela, Carlos; Paternina-Caicedo, Ángel; Pinzón-Redondo, Hernando; Carrasquilla-Sotomayor, María; Alvis-Guzmán, Nelson; De La Hoz-Restrepo, Fernando

    2018-04-05

    The aim of the present study was to estimate the economic impact of chikungunya virus (CHIKV) infection in Colombia from a societal perspective. We conducted a retrospective, bottom-up cost-of-illness study in clinically confirmed cases during the first chikungunya (CHIK) outbreak in Colombia in 2014. Direct and indirect costs were estimated per patient. Economic costs were calculated by the addition of direct costs (direct medical costs and out-of-pocket heath expenditures) and indirect cost as a result of loss of productivity. A total of 126 patients (67 children and 59 adults) with CHIK were included. The median of the direct medical cost in children was US$257.9 (interquartile range [IQR] 121.7-563.8), and US$66.6 (IQR 26.5-317.3) for adults. The productivity loss median expenditures reached US$81.3 (IQR 72.2-203.2) per adult patient. The median economic cost in adults as a result of CHIK was US$152.9 (IQR 101.0-539.6), of which 53.2% was a result of indirect costs. Out-of-pocket expenditures comprised 3.3% of all economic costs. Our study can help health decision makers to properly assess the burden of disease caused by CHIK in Colombia, an endemic tropical country. We recommend to strength the health information systems and to continue investing in public health measures to prevent CHIK. Copyright © 2018. Published by Elsevier Inc.

  15. ASSESSING TRANSBOUNDARY INFLUENCES IN THE LOWER RIO GRANDE VALLEY (COMMUNITY SUMMARY)

    EPA Science Inventory

    The Lower Rio Grande Valley Transboundary Air Pollution Project (TAPP) was done to determine if movement of air pollutants across the U.S.-Mexico border was occurring in the Lower Rio Grande Valley (hereinafter called "the Valley") and, if so, the extent. The study w...

  16. Rock Stripes Pattern in Mars' 'Perseverance Valley'

    NASA Image and Video Library

    2018-02-15

    Textured rows on the ground in this portion of "Perseverance Valley" are under investigation by NASA's Mars Exploration Rover Opportunity, which used its Navigation Camera (Navcam) to take the component images of this downhill-looking scene. The rover took this image on Jan. 4, 2018, during the 4,958th Martian day, or sol, of its work on Mars, looking downhill from a position about one-third of the way down the valley. Perseverance Valley descends the inboard slope of the western rim of Endeavour Crater. A view on the same sol with the rover's front Hazard Avoidance Camera includes ground even closer to the rover at this site. Opportunity was still working close by as it reached the mission's Sol 5,000 (Feb. 16, 2018). In the portion of the valley seen here, soil and gravel have been shaped into a striped pattern in the foreground and partially bury outcrops visible in the midfield. The long dimensions of the stripes are approximately aligned with the downhill direction. The striped pattern resembles a type of feature on Earth (such as on Hawaii's Mauna Kea) that is caused by repeated cycles of freezing and thawing, though other possible origins are also under consideration for the pattern in Perseverance Valley. The view is spans from north on the left to east-southeast on the right. For scale, the foreground rock clump in the lower right is about 11 inches (28 centimeters) in width. https://photojournal.jpl.nasa.gov/catalog/PIA22217

  17. Colombia’s Conflicts: The Spillover Effects of a Wider War

    DTIC Science & Technology

    2002-10-01

    a summary of the history and impact of civil violence on Colombian history, see Comision de estudios sobre la violencia, Colombia: Violencia y...Brasilia pie acapos del Cartel de brasil,” El Nuevo Herald, March 27, 2001; Mendel, p. 7. 87. Quoted in Gentleman, pp. 28-29. 88. “Tracion en el mercado ...guerrilla groups, the leftist Revolutionary Armed Forces of Colombia (FARC) and Ejercito de Liberacion Nacional (ELN) and the rightist Auto Defensas

  18. Geohydrology of the Valley-Fill Aquifers between the Village of Greene, Chenango County and Chenango Valley State Park, Broome County, New York

    USGS Publications Warehouse

    Hetcher-Aguila, Kari K.; Miller, Todd S.

    2005-01-01

    The confined aquifer is widely used by people living and working in the Chenango River valley. The confined aquifer consists of ice-contact sand and gravel, typically overlies bedrock, and underlies a confining unit consisting of lacustrine fine sand, silt, and clay. The confining unit is typically more than 100 feet thick in the central parts of the valley between Greene Landing Field and along the northern edge of the Chenango Valley State Park. The thickness of the confined aquifer is more than 40 feet near the Greene Landing Field.

  19. Death Valley, California

    NASA Image and Video Library

    1994-04-11

    STS059-S-026 (11 April 1994) --- This is an image of Death Valley, California, centered at 36.629 degrees north latitude, 117.069 degrees west longitude. The image shows Furnace Creek alluvial fan and Furnace Creek Ranch at the far right, and the sand dunes near Stove Pipe Wells at the center. The dark fork-shaped feature between Furnace Creek fan and the dunes is a smooth flood-plain which encloses Cottonball Basin. The SIR-C/X-SAR supersite is an area of extensive field investigations and has been visited by both Space Radar Lab astronaut crews. Elevations in the Valley range from 70 meters below sea level, the lowest in the United States, to more than 3300 meters above sea level. Scientists are using SIR-C/X-SAR data from Death Valley to help answer a number of different questions about the Earth's geology. One question concerns how alluvial fans are formed and change through time under the influence of climatic changes and earthquakes. Alluvial fans are gravel deposits that wash down from the mountains over time. They are visible in the image as circular, fan-shaped bright areas extending into the darker valley floor from the mountains. Information about the alluvial fans help scientists study Earth's ancient climate. Scientists know the fans are bulit up through climatic and tectonic processes and they will use the SIR-C/X-SAR data to understand the nature and rates of weathering processes on the fans, soil formation, and the transport of sand and dust by the wind. SIR-C/X-SAR's sensitivity to centimeter-scale (or inch-scale) roughness provides detailed maps of surface texture. Such information can be used to study the occurrence and movement of dust storms and sand dunes. the goal of these studies is to gain a better understanding of the record of past climatic changes and the effects of those changes on a sensitive environment. This may lead to a better ability to predict future response of the land to different potential global cimate-change scenarios

  20. Groundwater quality in the Antelope Valley, California

    USGS Publications Warehouse

    Dawson, Barbara J. Milby; Belitz, Kenneth

    2012-01-01

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Antelope Valley is one of the study areas being evaluated. The Antelope study area is approximately 1,600 square miles (4,144 square kilometers) and includes the Antelope Valley groundwater basin (California Department of Water Resources, 2003). Antelope Valley has an arid climate and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). The study area has internal drainage, with runoff from the surrounding mountains draining towards dry lakebeds in the lower parts of the valley. Land use in the study area is approximately 68 percent (%) natural (mostly shrubland and grassland), 24% agricultural, and 8% urban. The primary crops are pasture and hay. The largest urban areas are the cities of Palmdale and Lancaster (2010 populations of 152,000 and 156,000, respectively). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in Antelope Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Antelope Valley are completed to depths between 360 and 700 feet (110 to 213 meters), consist of solid casing from the land surface to a depth of 180 to 350 feet (55 to 107 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the surrounding mountains, and by direct infiltration of irrigation and sewer and septic

  1. Present Status of Historical Seismicity Studies in Colombia and Venezuela

    NASA Astrophysics Data System (ADS)

    Sarabia, A.; Cifuentes, H.; Altez Ortega, R.; Palme, C.; Dimate, C.

    2013-05-01

    After the publication of the SISRA (CERESIS-1985) regional project, a unified catalog of seismic parameters and intensities for South America, researchers in historical seismicity have continued advancing on different scales in the area of this study of seismic hazard. The most important initiatives carried out in this area in Colombia and Venezuela can be grouped as follows: a) Reviews of destructive earthquakes in national and international historic archives, principally by Altez and FUNVISIS in Venezuela and Espinosa, Salcedo, and Sarabia et al in Colombia, leading to the preparation of seismologic catalogues, scientific and dissemination articles, reports, books, among others. b) Organization and systematization of historic information to develop public domain data bases and information, specifically the Historic Seismologic Teleinformation System in Venezuela, carried out between 2004 and 2008 under the coordination of Christl Palme and accessible on-line: http://sismicidad.ciens.ula.ve. As well, the "Historia Sísmica de Colombia 1550-1830" (Seismic History in Colombia 1550-1830) data base, in CD-ROM, by Espinosa Baquero (2003) and the historic seismicity information system of Colombia (Servicio Geológico Colombiano-Universidad Nacional de Colombia), published on the internet in 2012: http://agata.ingeominas.gov.co:9090/SismicidadHistorica/. c) Macroseismic studies for the development of intensity attenuation equations and the quantification and revaluation of basic historic earthquake parameters using isoseismal maps (Rengifo et al., Palme et al., Salcedo et al., among others) and procedures such as Boxer and Bakun & Wentworth (Palme et al., Dimaté, among others), which have produced significant changes in the parameters of some of the large earthquakes. d) Symposiums of researchers to promote interest and development in the discipline, including Jornadas Venezolanas de Sismología Histórica (Venezuelan Congress of Historical Seismology), held

  2. [Local contexts of drinking-water quality surveillance: Brazil and Colombia].

    PubMed

    Guzmán-Barragán, Blanca L; Días Bevilacqua, Paula; Nava-Tovar, Gerardo

    2015-12-01

    Objective This article aims to analyze comparatively the national surveillance systems of water quality for human consumption (DWQS) of Brazil and Colombia, seeking to understand how practices are organized in these countries, along with their limits and possibilities. Methods The National Cross Comparison methodology was used with document analysis of secondary sources, with the purpose of discussing the similarities and differences between the two systems using the WHO’s Guidelines for Drinking Water Quality. Results The legal framework on DWQS in Brazil and Colombia was defined in the 70s and 80s, coinciding with the international visibility of this issue. Thereafter, DWQS practices in Brazil have been defined and organized in a national program, which has only recently started in Colombia. The current Brazilian and Colombian legislations show progress in technical elements that guide surveillance practices, such as the incorporation of risk assessment methodologies. The Colombian legislation defines the regulation of water supply services provision, which is not contemplated in Brazilian legislation. Elements such as decentralization, intersectionality, universality and right to information are included in the legislations of both countries, although further action on DWQS is needed. Conclusions Brazil and Colombia have similarities in the implementation of DWQS, despite being at different points in the implementation timeline. Actions on drinking-water quality surveillance are necessary to guarantee human rights related to the protection of the environment, such as universal access to drinking water, contributing to the promotion of health.

  3. Solar energy innovation and Silicon Valley

    NASA Astrophysics Data System (ADS)

    Kammen, Daniel M.

    2015-03-01

    The growth of the U. S. and global solar energy industry depends on a strong relationship between science and engineering innovation, manufacturing, and cycles of policy design and advancement. The mixture of the academic and industrial engine of innovation that is Silicon Valley, and the strong suite of environmental policies for which California is a leader work together to both drive the solar energy industry, and keep Silicon Valley competitive as China, Europe and other area of solar energy strength continue to build their clean energy sectors.

  4. The Health Valley: Global Entrepreneurial Dynamics.

    PubMed

    Dubuis, Benoit

    2014-12-01

    In the space of a decade, the Lake Geneva region has become the Health Valley, a world-class laboratory for discovering and developing healthcare of the future. Through visionary individuals and thanks to exceptional infrastructure this region has become one of the most dynamic in the field of innovation, including leading scientific research and exceptional actors for the commercialization of academic innovation to industrial applications that will improve the lives of patients and their families. Here follows the chronicle of a spectacular expansion into the Health Valley.

  5. Subsurface Salts in Antarctic Dry Valley Soils

    NASA Technical Reports Server (NTRS)

    Englert, P.; Bishop, J. L.; Gibson, E. K.; Koeberl, C.

    2013-01-01

    The distribution of water-soluble ions, major and minor elements, and other parameters were examined to determine the extent and effects of chemical weathering on cold desert soils. Patterns at the study sites support theories of multiple salt forming processes, including marine aerosols and chemical weathering of mafic minerals. Periodic solar-mediated ionization of atmospheric nitrogen might also produce high nitrate concentrations found in older sediments. Chemical weathering, however, was the major contributor of salts in Antarctic Dry Valleys. The Antarctic Dry Valleys represent a unique analog for Mars, as they are extremely cold and dry desert environments. Similarities in the climate, surface geology, and chemical properties of the Dry Valleys to that of Mars imply the possible presence of these soil formation mechanisms on Mars, other planets and icy satellites.

  6. Topologically protected refraction of robust kink states in valley photonic crystals

    NASA Astrophysics Data System (ADS)

    Gao, Fei; Xue, Haoran; Yang, Zhaoju; Lai, Kueifu; Yu, Yang; Lin, Xiao; Chong, Yidong; Shvets, Gennady; Zhang, Baile

    2018-02-01

    Recently discovered valley photonic crystals (VPCs) mimic many of the unusual properties of two-dimensional (2D) gapped valleytronic materials. Of the utmost interest to optical communications is their ability to support topologically protected chiral edge (kink) states at the internal domain wall between two VPCs with opposite valley-Chern indices. Here we experimentally demonstrate valley-polarized kink states with polarization multiplexing in VPCs, designed from a spin-compatible four-band model. When the valley pseudospin is conserved, we show that the kink states exhibit nearly perfect out-coupling efficiency into directional beams, through the intersection between the internal domain wall and the external edge separating the VPCs from ambient space. The out-coupling behaviour remains topologically protected even when we break the spin-like polarization degree of freedom (DOF), by introducing an effective spin-orbit coupling in one of the VPC domains. This also constitutes the first realization of spin-valley locking for topological valley transport.

  7. Water availability and subsidence in California's Central Valley

    USGS Publications Warehouse

    Faunt, Claudia C.; Sneed, Michelle

    2015-01-01

    California’s Central Valley covers about 52,000 square kilometers (km2) and is one of the most productive agricultural regions in the world. More than 250 different crops are grown in the broad alluvial filled structural trough, with an estimated value exceeding $20 billion per year (Faunt 2009) (Figure 1). Central Valley agriculture depends on state and federal water systems that divert surface water, predominantly originating from Sierra Nevada snowmelt, to agricultural fields. Because the valley is semi-arid and the availability of surface water varies substantially from year to year, season to season, and from north to south, agriculture, as it grew, developed a reliance on groundwater for irrigation.

  8. Hydrologic reconnaissance of Curlew Valley, Utah and Idaho

    USGS Publications Warehouse

    Bolke, E.L.; Price, Don

    1969-01-01

    This report is the fifth in a series of reports prepared by the U. S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, that describe the water resources of selected basins in western Utah. Previously published reports in this series are listed on page 35 and the areas covered by them are shown in figure 1. The purpose of this report is to present available hydrologic data on the Utah part of Curlew Valley, to provide an evaluation of the potential water-resource development of the valley, and to identify needed studies that would help provide an understanding of the valley's water supply.

  9. A new species and new records of Cryptodacus (Diptera: Tephritidae) from Colombia, Bolivia and Peru.

    PubMed

    Rodriguez, Pedro Alexander; Rodriguez, Erick J; Norrbom, Allen L; Arévalo, Emilio

    2016-05-16

    Cryptodacus bernardoi Rodriguez & Rodriguez, new species, is described from Colombia. It was reared from fruits of Phoradendron sp. near piperoides (Kunth) Trel. New distribution records are reported for Cryptodacus ornatus Norrbom from Colombia and Peru, for Cryptodacus trinotatus Norrbom & Korytkowski from Colombia, and for Cryptodacus obliquus Hendel from Bolivia and Peru. The female abdomen and terminalia of C. obliquus is described for the first time. The Norrbom & Korytkowski (2008)`s key to species was modified to include C. bernardoi n. sp.

  10. The Boulder Valley Internet Project: Teachers Mentoring Teachers.

    ERIC Educational Resources Information Center

    Sherry, Lorraine; Lawyer-Brook, Dianna

    The Boulder Valley Internet Project (BVIP) was begun as a collaborative venture between the University of Colorado at Boulder and the Boulder Valley School District. The project's organizing aims of integrating Internet-based activities into curriculum and instruction have not been met fully due to the inhibiting characteristics of education…

  11. Revisiting Valley Development on Martian Volcanoes Using MGS and Odyssey Data

    NASA Technical Reports Server (NTRS)

    Gulick, Virginia C.

    2005-01-01

    The valley networks found on the slopes of Martian volcanoes represent an interesting subset of the Martian valley networks. Not only do the volcanoes constrain the possible geologic settings, they also provide a window into Martian valley development through time, as the volcanoes formed throughout the geologic history of Mars. Here I take another look at this intriguing subset of networks by revisiting conclusions reached in my earlier studies using the Viking imagery and the valleys on Hawaii as an analog. I then examine more recent datasets.

  12. 77 FR 71778 - U.S. Infrastructure Trade Mission to Colombia and Panama; Bogotá, Columbia and Panama City...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-04

    ... Colombia and Panama; Bogot[aacute], Columbia and Panama City, Panama, May 13-16, 2012 AGENCY: International... Department of Commerce is organizing a Trade Mission to Bogot[aacute], Colombia and Panama City, Panama... appointments with local companies, as well as market briefings, and networking events. In both Colombia and...

  13. Heat flow from eastern Panama and northwestern Colombia

    USGS Publications Warehouse

    Sass, J.H.; Munroe, R.J.; Moses, T.H.

    1974-01-01

    Heat flows were determined at 12 sites in four distinct areas between longitude 77?? and 80??W in eastern Panama and northwestern Colombia. Evidently, most of the region is underlain by mafic oceanic crust so that the crustal radiogenic component of heat flow is very small (??? 0.1 ??cal cm-2 sec-1). Low heat-flow values (??? 0.7 ??cal cm-2 sec-1) in northwestern Colombia may reflect thermal transients associated with shallow subduction. The normal values (??? 1) at about 78??W are consistent with the mean heat flow from the western Caribbean and the Gulf of Mexico. At 80??W, a fairly high value of 1.8 may define the easterly limit of thermal transients due to Cenozoic volcanic activity in Central America. ?? 1974.

  14. Goldstone-Apple Valley Radio Telescope System Theory of Operation

    NASA Technical Reports Server (NTRS)

    Stephan, George R.

    1997-01-01

    The purpose of this learning module is to enable learners to describe how the Goldstone-Apple Valley Radio Telescope (GAVRT) system functions in support of Apple Valley Science and Technology Center's (AVSTC) client schools' radio astronomy activities.

  15. Establishing Ripe Moments for Negotiated Settlement in Counterinsurgency: An Example from Colombia

    DTIC Science & Technology

    2017-05-25

    Rickmeyer Monograph Title : Establishing Ripe Moments for Negotiated Settlement in Counterinsurgency: An Example from Colombia Approved by...Establishing Ripe Moments for Negotiated Settlement in Counterinsurgency: An Example from Colombia A Monograph by MAJ Paul F. Rickmeyer US Army...05-2017 2. REPORT TYPE Mater’s Thesis 3. DATES COVERED (From - To) JUN 2016 – MAY 2017 4. TITLE AND SUBTITLE Establishing Ripe Moments for

  16. 27 CFR 9.44 - Solano County Green Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Solano County Green Valley. 9.44 Section 9.44 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... Solano County Green Valley. (a) Name. The name of the viticultural area described in this section is...

  17. Rift Valley Fever Outbreak in Livestock, Mozambique, 2014.

    PubMed

    Fafetine, José M; Coetzee, Peter; Mubemba, Benjamin; Nhambirre, Ofélia; Neves, Luis; Coetzer, J A W; Venter, Estelle H

    2016-12-01

    In early 2014, abortions and death of ruminants were reported on farms in Maputo and Gaza Provinces, Mozambique. Serologic analysis and quantitative and conventional reverse transcription PCR confirmed the presence of Rift Valley fever virus. The viruses belonged to lineage C, which is prevalent among Rift Valley fever viruses in southern Africa.

  18. Influence of Valley Floor Landforms on Stream Ecosystems

    Treesearch

    Stanley V. Gregory; Gary A. Lamberti; Kelly M. S. Moore

    1989-01-01

    A hierarchical perspective of relationships between valley floor landforms, riparian plant communities, and aquatic ecosystems has been developed, based on studies of two fifth-order basins in the Cascade Mountains of Oregon. Retention of dissolved nitrogen and leaves were approximately 2-3 times greater in unconstrained reaches than in constrained reaches. Both valley...

  19. Reconnaissance of the chemical quality of water in western Utah, Part I: Sink Valley area, drainage basins of Skull, Rush, and Government Creek Valleys, and the Dugway Valley-Old River Bed area

    USGS Publications Warehouse

    Waddell, K.M.

    1967-01-01

    This report presents data collected during the first part of an investigation that was started in 1963 by the U.S. Geological Survey in cooperation with the Utah Geological and Mineralogical Survey. The investigation has the purpose of providing information about the chemical quality of water in western Utah that will help interested parties to evaluate the suitability of the water for various uses in a broad area of Utah where little information of this type previously has been available. The area studied includes the Sink Valley area, the drainage basins of Skull, Rush, and Government Creek Valleys, and the Dugway Valley-Old River Bed area (fig. 1). Osamu Hattori and G. L. Hewitt started the investigation, and the author completed it and prepared the report.

  20. Valley-controlled propagation of pseudospin states in bulk metacrystal waveguides

    NASA Astrophysics Data System (ADS)

    Chen, Xiao-Dong; Deng, Wei-Min; Lu, Jin-Cheng; Dong, Jian-Wen

    2018-05-01

    Light manipulations such as spin-direction locking propagation, robust transport, quantum teleportation, and reconfigurable electromagnetic pathways have been investigated at the boundaries of photonic systems. Recently by breaking Dirac cones in time-reversal-invariant photonic crystals, valley-pseudospin coupled edge states have been employed to realize selective propagation of light. Here, we realize the controllable propagation of pseudospin states in three-dimensional bulk metacrystal waveguides by valley degree of freedom. Reconfigurable photonic valley Hall effect is achieved for frequency-direction locking propagation in such a way that the propagation path can be tunable precisely by scanning the working frequency. A complete transition diagram is illustrated on the valley-dependent pseudospin states of Dirac-cone-absent photonic bands. A photonic blocker is proposed by cascading two inversion asymmetric metacrystal waveguides in which pseudospin-direction locking propagation exists. In addition, valley-dependent pseudospin bands are also discussed in a realistic metamaterials sample. These results show an alternative way toward molding the pseudospin flow in photonic systems.

  1. Synthetic River Valleys

    NASA Astrophysics Data System (ADS)

    Brown, R.; Pasternack, G. B.

    2011-12-01

    The description of fluvial form has evolved from anecdotal descriptions to artistic renderings to 2D plots of cross section or longitudinal profiles and more recently 3D digital models. Synthetic river valleys, artificial 3D topographic models of river topography, have a plethora of potential applications in fluvial geomorphology, and the earth sciences in general, as well as in computer science and ecology. Synthetic river channels have existed implicitly since approximately the 1970s and can be simulated from a variety of approaches spanning the artistic and numerical. An objective method of synthesizing 3D stream topography based on reach scale attributes would be valuable for sizing 3D flumes in the physical and numerical realms, as initial input topography for morphodynamic models, stream restoration design, historical reconstruction, and mechanistic testing of interactions of channel geometric elements. Quite simply - simulation of synthetic channel geometry of prescribed conditions can allow systematic evaluation of the dominant relationships between river flow and geometry. A new model, the control curve method, is presented that uses hierarchically scaled parametric curves in over-lapping 2D planes to create synthetic river valleys. The approach is able to simulate 3D stream geometry from paired 2D descriptions and can allow experimental insight into form-process relationships in addition to visualizing past measurements of channel form that are limited to two dimension descriptions. Results are presented that illustrate the models ability to simulate fluvial topography representative of real world rivers as well as how channel geometric elements can be adjusted. The testing of synthetic river valleys would open up a wealth of knowledge as to why some 3D attributes of river channels are more prevalent than others as well as bridging the gap between the 2D descriptions that have dominated fluvial geomorphology the past century and modern, more complete, 3D

  2. Valley-symmetric quasi-1D transport in ballistic graphene

    NASA Astrophysics Data System (ADS)

    Lee, Hu-Jong

    We present our recent studies on gate-defined valley-symmetric one-dimensional (1D) carrier guiding in ballistic monolayer graphene and valley-symmetry-protected topological 1D transport in ballistic bilayer graphene. Successful carrier guiding was realized in ballistic monolayer graphene even in the absence of a band gap by inducing a high distinction ( more than two orders of magnitude) in the carrier density between the region of a quasi-1D channel and the rest of the top-gated regions. Conductance of a channel shows quantized values in units of 4e2/ h, suggesting that the valley symmetry is preserved. For the latter, the topological 1D conduction was realized between two closely arranged insulating regions with inverted band gaps, induced under a pair of split dual gating with polarities opposite to each other. The maximum conductance along the boundary channel showed 4e2/ h, again with the preserved valley symmetry. The 1D topological carrier guiding demonstrated in this study affords a promising route to robust valleytronic applications and sophisticated valley-associated functionalities based on 2D materials. This work was funded by the National Research Foundation of Korea.

  3. Evolution of collapse valleys in karst - examples from the Carpatho-Balkanides of Serbia

    NASA Astrophysics Data System (ADS)

    Petrović, Aleksandar S.; Ćalić, Jelena; Spalević, Aleksandra; Pantić, Marko

    2016-04-01

    Development of valleys in karst is an issue which has not been sufficiently studied in karst surface morphology. THESE valleys are long linear forms whose orthogonal projections resemble normal valleys, but most of their characteristics are strongly influenced by karst process. In largest number of relevant references, this subject is either only briefly mentioned or completely lacking. This paper presents the examples of a particular type of valley in karst formed by cave ceiling collapse close to the topographical surface. Karst of the Carpatho-Balkanides in eastern Serbia is characterized by uneven spatial distribution in several large massifs, but also in a large number of relatively small outcrops (patches and belts), which enable the development of contact karst and fluviokarst. Many morphological elements are of fluvial origin, subsequently modified by karst process. Collapse valleys occur mostly at the downstream contacts (where a seasonal watercourse leaves limestones) or in karst/limestone belts. In the first phase, which is visible on the example of the Radovanska Reka, the river course sinks to the swallets in the riverbed and forms a blind valley. After sinking, the water flows through the tunnel cave, while largest part of the valley remains above the cave. The bottom of the dry valley is dissected by deep dolines, reaching almost to the cave roof. In this part of the study, the area was scanned by a multistation Leica Nova MS 50 (resolution 20 cm @ 10 m). In the second phase, the doline bottoms reach the cave ceilings which develop holes at certain points, as it is case at the Zamna River valley. These hollows tend to enlarge with time, and the surface of the cave ceiling is reduced. The third, final phase is characterised by collapse of larger segments of cave ceilings. Only the natural bridges remain, as the remnants of former caves (e.g. in the Vratna River valley, Ravna Reka valley). These parts of valleys in karst are usually narrow, steep

  4. Geohydrology and Water Quality of the Valley-Fill Aquifer System in the Upper Sixmile Creek and West Branch Owego Creek Valleys in the Town of Caroline, Tompkins County, New York

    USGS Publications Warehouse

    Miller, Todd S.

    2009-01-01

    In 2002, the U.S. Geological Survey, in cooperation with the Town of Caroline and Tompkins County Planning Department, began a study of the valley-fill aquifer system in upper Sixmile Creek and headwaters of West Branch Owego Creek valleys in the Town of Caroline, NY. The purpose of the study is to provide geohydrologic data to county and town planners as they develop a strategy to manage and protect their water resources. The first aquifer reach investigated in this series is in the Town of Caroline and includes the upper Sixmile Creek valley and part of West Branch Owego Creek valley. The portions of the valley-fill aquifer system that are comprised of saturated coarse-grained sediments including medium to coarse sand and sandy gravel form the major aquifers. Confined sand and gravel units form the major aquifers in the western and central portions of the upper Sixmile Creek valley, and an unconfined sand and gravel unit forms the major aquifer in the eastern portion of the upper Sixmile Creek valley and in the headwaters of the West Branch Owego Creek valley. The valley-fill deposits are thinnest near the edges of the valley where they pinch out along the till-mantled bedrock valley walls. The thickness of the valley fill in the deepest part of the valley, at the western end of the study area, is about 100 feet (ft); the thickness is greater than 165 ft on top of the Valley Heads Moraine in the central part of the valley. An estimated 750 people live over and rely on groundwater from the valley-fill aquifers in upper Sixmile Creek and West Branch Owego Creek valleys. Most groundwater withdrawn from the valley-fill aquifers is pumped from wells with open-ended 6-inch diameter casings; the remaining withdrawals are from shallow dug wells or cisterns that collect groundwater that discharges to springs (especially in the Brooktondale area). The valley-fill aquifers are the sources of water for about 200 households, several apartment complexes, two mobile home parks

  5. Spin and Valley Noise in Two-Dimensional Dirac Materials

    NASA Astrophysics Data System (ADS)

    Tse, Wang-Kong; Saxena, A.; Smith, D. L.; Sinitsyn, N. A.

    2014-07-01

    We develop a theory for optical Faraday rotation noise in two-dimensional Dirac materials. In contrast to spin noise in conventional semiconductors, we find that the Faraday rotation fluctuations are influenced not only by spins but also the valley degrees of freedom attributed to intervalley scattering processes. We illustrate our theory with two-dimensional transition-metal dichalcogenides and discuss signatures of spin and valley noise in the Faraday noise power spectrum. We propose optical Faraday noise spectroscopy as a technique for probing both spin and valley relaxation dynamics in two-dimensional Dirac materials.

  6. Distribution of glacial deposits, soils, and permafrost in Taylor Valley, Antarctica

    USGS Publications Warehouse

    Bockheim, James G.; Prentice, M.L.; McLeod, M.

    2008-01-01

    We provide a map of lower and central Taylor Valley, Antarctica, that shows deposits from Taylor Glacier, local alpine glaciers, and grounded ice in the Ross Embayment. From our electronic database, which includes 153 sites from the coast 50 km upvalley to Pearse Valley, we show the distribution of permafrost type and soil subgroups according to Soil Taxonomy. Soils in eastern Taylor Valley are of late Pleistocene age, cryoturbated due to the presence of ground ice or ice-cemented permafrost within 70 cm of the surface, and classified as Glacic and Typic Haploturbels. In central Taylor Valley, soils are dominantly Typic Anhyorthels of mid-Pleistocene age that have dry-frozen permafrost within the upper 70 cm. Salt-enriched soils (Salic Anhyorthels and Petrosalic Anhyorthels) are of limited extent in Taylor Valley and occur primarily on drifts of early Pleistocene and Pliocene age. Soils are less developed in Taylor Valley than in nearby Wright Valley, because of lesser salt input from atmospheric deposition and salt weathering. Ice-cemented permafrost is ubiquitous on Ross Sea, pre-Ross Sea, and Bonney drifts that occur within 28 km of the McMurdo coast. In contrast, dry-frozen permafrost is prevalent on older (???115 ky) surfaces to the west. ?? 2008 Regents of the University of Colorado.

  7. The T-REX valley wind intercomparison project

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schmidli, J; Billings, B J; Burton, R

    2008-08-07

    An accurate simulation of the evolution of the atmospheric boundary layer is very important, as the evolution of the boundary layer sets the stage for many weather phenomena, such as deep convection. Over mountain areas the evolution of the boundary layer is particularly complex, due to the nonlinear interaction between boundary layer turbulence and thermally-induced mesoscale wind systems, such as the slope and valley winds. As the horizontal resolution of operational forecasts progresses to finer and finer resolution, more and more of the thermally-induced mesoscale wind systems can be explicitly resolved, and it is very timely to document the currentmore » state-of-the-art of mesoscale models at simulating the coupled evolution of the mountain boundary layer and the valley wind system. In this paper we present an intercomparison of valley wind simulations for an idealized valley-plain configuration using eight state-of-the-art mesoscale models with a grid spacing of 1 km. Different sets of three-dimensional simulations are used to explore the effects of varying model dynamical cores and physical parameterizations. This intercomparison project was conducted as part of the Terrain-induced Rotor Experiment (T-REX; Grubisic et al., 2008).« less

  8. Technology Finds Its Place in Silicon Valley Schools

    ERIC Educational Resources Information Center

    Hundley, Paula; Scigliano, Marie

    2012-01-01

    Technology today is poised to usher in the best of times. Exploring what other districts do highlights the common themes as well as the unique challenges. Three very different districts in Silicon Valley--Portola Valley School District, Campbell Union School District and San Jose Unified School District--explain the strategies they use to enhance…

  9. Organisms of the Hubbard Brook Valley, New Hampshire

    Treesearch

    Richard T. Holmes; Gene E. Likens

    1999-01-01

    Lists the organisms, both plant and animal, that have been identified by scientists engaged in multidisciplinary ecological research in the Hubbard Brook Valley, New Hampshire, during the past three decades. The Valley encompasses the Hubbard Brook Experimental Forest, Mirror Lake, and nearby areas within the White Mountain region of Grafton County. The species lists...

  10. Rift Valley Fever Outbreak in Livestock, Mozambique, 2014

    PubMed Central

    Coetzee, Peter; Mubemba, Benjamin; Nhambirre, Ofélia; Neves, Luis; Coetzer, J.A.W.; Venter, Estelle H.

    2016-01-01

    In early 2014, abortions and death of ruminants were reported on farms in Maputo and Gaza Provinces, Mozambique. Serologic analysis and quantitative and conventional reverse transcription PCR confirmed the presence of Rift Valley fever virus. The viruses belonged to lineage C, which is prevalent among Rift Valley fever viruses in southern Africa. PMID:27869589

  11. Geophysical setting of the Wabash Valley fault system

    USGS Publications Warehouse

    Hildenbrand, T.G.; Ravat, D.

    1997-01-01

    Interpretation of existing regional magnetic and gravity data and new local high-resolution aeromagnetic data provides new insights on the tectonic history and structural development of the Wabash Valley Fault System in Illinois and Indiana. Enhancement of short-wavelength magnetic anomalies reveal numerous NW- to NNE-trending ultramafic dikes and six intrusive complexes (including those at Hicks Dome and Omaha Dome). Inversion models indicate that the interpreted dikes are narrow (???3 m), lie at shallow depths (500 km long and generally >50 km wide) and with deep basins (locally >3 km thick), the ancestral Wabash Valley faults express, in comparison, minor tectonic structures and probably do not represent a failed rift arm. There is a lack of any obvious relation between the Wabash Valley Fault System and the epicenters of historic and prehistoric earthquakes. Five prehistoric earthquakes lie conspicuously near structures associated with the Commerce geophysical lineament, a NE-trending magnetic and gravity lineament lying oblique to the Wabash Valley Fault System and possibly extending over 600 km from NE Arkansas to central Indiana.

  12. 'BEST MANAGEMENT PRACTICES' FOR SALINITY CONTROL IN GRAND VALLEY

    EPA Science Inventory

    A nontechnical summary of several research activities in the Grand Valley is given. Analyses of alternative measures of reducing the salt load originating from the Valley as a result of irrigation return flows are presented. These alternatives include conveyance channel linings, ...

  13. Implementation and adaptation in Colombia of the Communities That Care.

    PubMed

    Mejía-Trujillo, Juliana; Pérez-Gómez, Augusto; Reyes-Rodríguez, María Fernanda

    2015-12-15

    For more than two years, Corporación Nuevos Rumbos (Colombia) has been carrying out, in eight Colombian communities, a preventive system called Comunidades Que se Cuidan (CQC), an adaptation of Communities That Care (CTC), created at the University of Washington (Seattle), developed for more than 25 years in the United States of America and implemented in eight countries of America, Oceania, and Europe. The system is based on the public health approach, and the social development strategy for community empowerment. The core idea is to teach communities how to make decisions based on data regarding drugs and alcohol consumption and the identification of protective and risk factors, on the basis of the original survey validated in Colombia: these will allow communities to choose the best preventive interventions, tailored for each of them according to their needs. This paper describes the process of implementation of CQC in Colombia, its differences with CTC, the creation of Colombian cut-points, the main difficulties and how these were solved. CQC seems to be a preventive system with a wide potential applicability in other Latin American countries.

  14. Influence of southwest monsoons in the Kashmir Valley, western Himalayas.

    PubMed

    Jeelani, Ghulam; Deshpande, Rajendrakumar D; Shah, Rouf A; Hassan, Wasim

    2017-08-01

    The regional climate of the Himalayas is predominated by the southwest monsoons and the western disturbances. The uplift of the Pir Panjal to its present height is believed to restrict the southwest monsoons from entering into the Kashmir Valley in the western Himalayas. In the present study, monthly precipitation samples were collected across the Kashmir Valley from June 2013 to May 2014 for δ 18 O and δ 2 H analyses to constrain the influence of southwest monsoons in the valley. Except in August, the precipitation is enriched in 18 O and 2 H from June to September and depleted from October to May. The sharp depletion of 18 O in precipitation along with the decrease in d-excess in August confirm the maximum intrusion of southwest monsoons into the valley. A significant temperature - δ 18 O relationship was found during October and May (westerlies period) decreasing during June and September (southwest monsoon period). The local meteoric water line for the whole Kashmir Valley based on the precipitation-weighted monthly samples is [Formula: see text] [Formula: see text]. Higher intercept of the regression equation suggested dominant contribution of precipitation from western disturbances. The study suggested that the southwest monsoons enter the Kashmir Valley from southwest through the mountainous passes.

  15. Death Valley California as seen from STS-59

    NASA Image and Video Library

    1994-04-13

    STS059-86-059 (9-20 April 1994) --- This oblique handheld Hasselblad 70mm photo shows Death Valley, near California's border with Nevada. The valley -- the central feature of Death Valley National Monument -- extends north to south for some 140 miles (225 kilometers). Hemmed in to the east by the Amargosa Range and to the west by the Panamints, its width varies from 5 to 15 miles (8 to 24 kilometers). Using Spaceborne Imaging Radar (SIR-C) and X-band Synthetic Aperture Radar (X-SAR) onboard the Space Shuttle Endeavour, the crew was able to record a great deal of data on this and other sites, as part of NASA's Mission to Planet Earth.

  16. 75 FR 5761 - Executive-Led Trade Mission to Colombia and Panama; November 15-18, 2010

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-04

    ...; security and safety equipment; telecommunications equipment; and travel and tourism services. Commercial..., and tourism, among others. Colombia's increasingly democratic and transparent government and its... fifth largest city in Colombia concentrating business opportunities in ports, tourism, oil refinery and...

  17. How does network structure affect partnerships for promoting physical activity? Evidence from Brazil and Colombia.

    PubMed

    Parra, Diana C; Dauti, Marsela; Harris, Jenine K; Reyes, Lissette; Malta, Deborah C; Brownson, Ross C; Quintero, Mario A; Pratt, Michael

    2011-11-01

    The objective of this study was to describe the network structure and factors associated with collaboration in two networks that promote physical activity (PA) in Brazil and Colombia. Organizations that focus on studying and promoting PA in Brazil (35) and Colombia (53) were identified using a modified one-step reputational snowball sampling process. Participants completed an on-line survey between December 2008 and March 2009 for the Brazil network, and between April and June 2009 for the Colombia network. Network stochastic modeling was used to investigate the likelihood of reported inter-organizational collaboration. While structural features of networks were significant predictors of collaboration within each network, the coefficients and other network characteristics differed. Brazil's PA network was decentralized with a larger number of shared partnerships. Colombia's PA network was centralized and collaboration was influenced by perceived importance of peer organizations. On average, organizations in the PA network of Colombia reported facing more barriers (1.5 vs. 2.5 barriers) for collaboration. Future studies should focus on how these different network structures affect the implementation and uptake of evidence-based PA interventions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Agricultural Development, Land Change, and Livelihoods in Tanzania's Kilombero Valley

    NASA Astrophysics Data System (ADS)

    Connors, John Patrick

    The Kilombero Valley lies at the intersection of a network of protected areas that cross Tanzania. The wetlands and woodlands of the Valley, as well as the forest of surrounding mountains are abundant in biodiversity and are considered to be critical areas for conservation. This area, however, is also the home to more than a half million people, primarily poor smallholder farmers. In an effort to support the livelihoods and food security of these farmers and the larger Tanzanian population, the country has recently targeted a series of programs to increase agricultural production in the Kilombero Valley and elsewhere in the country. Bridging concepts and methods from land change science, political ecology, and sustainable livelihoods, I present an integrated assessment of the linkages between development and conservation efforts in the Kilombero Valley and the implications for food security. This dissertation uses three empirical studies to understand the process of development in the Kilombero Valley and to link the priorities and perceptions of conservation and development efforts to the material outcomes in food security and land change. The first paper of this dissertation examines the changes in land use in the Kilombero Valley between 1997 and 2014 following the privatization of agriculture and the expansion of Tanzania's Kilimo Kwanza program. Remote sensing analysis reveals a two-fold increase in agricultural area during this short time, largely at the expense of forest. Protected areas in some parts of the Valley appear to be deterring deforestation, but rapid agricultural growth, particularly surrounding a commercial rice plantation, has led to loss of extant forest and sustained habitat fragmentation. The second paper focuses examines livelihood strategies in the Valley and claims regarding the role of agrobiodiversity in food security. The results of household survey reveal no difference or lower food security among households that diversify their

  19. Ventilation potential during the emissions survey in Toluca Valley, Mexico

    NASA Astrophysics Data System (ADS)

    Ruiz Angulo, A.; Peralta, O.; Jurado, O. E.; Ortinez, A.; Grutter de la Mora, M.; Rivera, C.; Gutierrez, W.; Gonzalez, E.

    2017-12-01

    During the late-spring early-summer measurements of emissions and pollutants were carried out during a survey campaign at four different locations within the Toluca Valley. The current emissions inventory typically estimates the generation of pollutants based on pre-estimated values representing an entire sector function of their activities. However, those factors are not always based direct measurements. The emissions from the Toluca Valley are rather large and they could affect the air quality of Mexico City Valley. The air masses interchange between those two valleys is not very well understood; however, based on the measurements obtained during the 3 months campaign we looked carefully at the daily variability of the wind finding a clear signal for mountain-valley breeze. The ventilation coefficient is estimated and the correlations with the concentrations at the 4 locations and in a far away station in Mexico City are addressed in this work. Finally, we discuss the implication of the ventilation capacity in air quality for the system of Valleys that include Mexico City.

  20. 27 CFR 9.119 - Middle Rio Grande Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Middle Rio Grande Valley. 9.119 Section 9.119 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.119 Middle Rio Grande Valley. (a) Name. The...

  1. 27 CFR 9.119 - Middle Rio Grande Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Middle Rio Grande Valley. 9.119 Section 9.119 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.119 Middle Rio Grande Valley. (a) Name. The...

  2. Imperial Valley College 2+2+2 Project Handbook.

    ERIC Educational Resources Information Center

    Marquez, Ralph

    This handbook of the Imperial Valley College (IVC) 2+2+2 Project provides an overview of the development of an articulated education program for business and law enforcement careers, involving six local high schools and San Diego State University, Imperial Valley Campus. Following a brief introduction to the 2+2+2 project in section I, section II…

  3. Epidemiology of endemic goitre in western Colombia

    PubMed Central

    Gaitan, E.; Merino, H.; Rodriguez, G.; Medina, P.; Meyer, J. D.; DeRouen, T. A.; MacLennan, R.

    1978-01-01

    This paper reports on recent epidemiological observations in western Colombia, which further demonstrate the presence of naturally-occurring goitrogens contaminating water supplies in areas where goitre persists despite prolonged and continuous iodine supplementation. 'Prospective' and 'cross-sectional' studies in 41 localities where the populations have been on a uniform and adequate iodine supplementation for the last 10-20 years indicate that, in the endemia of western Colombia, environmental factors other than nutritional iodine deficiency are responsible for differences in goitre prevalence. Further epidemiological studies to determine the causal factors for the persistence of the endemia established a correlation between the sources of drinking water and goitre prevalence rates. Organic compounds containing sulfur with marked thionamide-like antithyroid activity were isolated from water supplying endemic goitre districts, and results are presented supporting the hypothesis that sedimentary rocks rich in organic matter are the main source of water-borne goitrogens. Bacteriological investigations showed that the presence of Klebsiella pneumoniae in drinking water and bacterial concentration were related significantly with goitre prevalence only in the presence of other variables, particularly the presence of sedimentary rocks. In the light of these epidemiological observations and experimental studies it may be concluded that, at present, endemic goitre in western Colombia is not due to nutritional iodine deficiency, but that water supplies are contaminated with sulfur-bearing organic compounds with thionamide-like antithyroid activity most probably deriving from sedimentary rocks rich in organic matter and that these compounds are the main factor underlying the endemia. PMID:80287

  4. [Characterisation of Suicide in Colombia, 2000 2010].

    PubMed

    Cardona Arango, Doris; Medina-Pérez, Óscar Adolfo; Cardona Duque, Deisy Viviana

    2016-01-01

    Suicide is a serious public health problem worldwide, affecting all population groups, regardless of age, gender, or area of residence. The aim of this investigation was to characterise the recorded suicides in Colombia, between the years 2000 and 2010, according to the variables of the person, time and place. Descriptive quantitative study with information from secondary sources, from the death certificates of deceased people by suicide registered with the National Bureau of Statistics. The behaviour of the deaths and mortality, were determined using the denominator population projections of Colombia and the Amazon, Andean, Atlantic Coast, Eastern Plains and Pacific regions. Descriptive measurements and mortality rates were calculated using these. A total of 24,882 suicides were recorded in the eleven years studied, with a mean of 6.2 people per day, which increased to 8.0 during holidays The mean age of death was 34.5 years (men 36.4, women 27.7), with male deaths (78.1%) and urban areas (66%) predominating. The greatest risk of dying from this cause was recorded in the Eastern Plains, in young adults and seniors, and residents in rural areas. Suicide rates in Colombia show a downward trend, with a mean of 5.3/100,000 inhabitants, and with an increased risk in men (3.7 times the risk in women, in young adults (9/100,000). A higher death rate was recorded in single people in the months of December and January, and at weekends. Copyright © 2015 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  5. Stratigraphy of the Mississippi-Alabama shelf and the Mobile River incised-valley system

    USGS Publications Warehouse

    Kindinger, Jack G.; Balson, Peter S.; Flocks, James G.; Dalrymple, Robert W.; Boyd, Ron; Zaitlin, Brian A.

    1994-01-01

    The Holocene incised-valley fill (estuarine facies) underlying Mobile Buy fit well into the conceptual facies model of a microtidal wave-dominated estuary. The model does not fit as well, however, with the rapidly transgressed shelf portion of the incised valley. The down dip section does not contain a clearly identifiable (from seismic profiles) estuarine facies; the valley fill is primarily fluvial and is overlain by marine shoals. In the Mobile River incised valley, the distal portion of the valley was rapidly drowned, allowing the thin estuarine facies to be reworked. The proximal portion was drowned more slowly, leaving the estuarine facies intact. Thus, the single incised valley contains two very different types of fill.

  6. Electrical generation and control of the valley carriers in a monolayer transition metal dichalcogenide

    NASA Astrophysics Data System (ADS)

    Ye, Yu; Xiao, Jun; Wang, Hailong; Ye, Ziliang; Zhu, Hanyu; Zhao, Mervin; Wang, Yuan; Zhao, Jianhua; Yin, Xiaobo; Zhang, Xiang

    2016-07-01

    Electrically controlling the flow of charge carriers is the foundation of modern electronics. By accessing the extra spin degree of freedom (DOF) in electronics, spintronics allows for information processes such as magnetoresistive random-access memory. Recently, atomic membranes of transition metal dichalcogenides (TMDCs) were found to support unequal and distinguishable carrier distribution in different crystal momentum valleys. This valley polarization of carriers enables a new DOF for information processing. A variety of valleytronic devices such as valley filters and valves have been proposed, and optical valley excitation has been observed. However, to realize its potential in electronics it is necessary to electrically control the valley DOF, which has so far remained a significant challenge. Here, we experimentally demonstrate the electrical generation and control of valley polarization. This is achieved through spin injection via a diluted ferromagnetic semiconductor and measured through the helicity of the electroluminescence due to the spin-valley locking in TMDC monolayers. We also report a new scheme of electronic devices that combine both the spin and valley DOFs. Such direct electrical generation and control of valley carriers opens up new dimensions in utilizing both the spin and valley DOFs for next-generation electronics and computing.

  7. Alternative Fuels Data Center: Lamoille Valley Ford Is #1 for Electric

    Science.gov Websites

    Vehicle Sales in Vermont Lamoille Valley Ford Is #1 for Electric Vehicle Sales in Vermont to someone by E-mail Share Alternative Fuels Data Center: Lamoille Valley Ford Is #1 for Electric Vehicle Electric Vehicle Sales in Vermont on Twitter Bookmark Alternative Fuels Data Center: Lamoille Valley Ford

  8. Debris flow occurrence and sediment persistence, Upper Colorado River Valley, CO

    USGS Publications Warehouse

    Grimsley, Kyle J; Rathburn, Sara L.; Friedman, Jonathan M.; Mangano, Joseph F.

    2016-01-01

    Debris flow magnitudes and frequencies are compared across the Upper Colorado River valley to assess influences on debris flow occurrence and to evaluate valley geometry effects on sediment persistence. Dendrochronology, field mapping, and aerial photographic analysis are used to evaluate whether a 19th century earthen, water-conveyance ditch has altered the regime of debris flow occurrence in the Colorado River headwaters. Identifying any shifts in disturbance processes or changes in magnitudes and frequencies of occurrence is fundamental to establishing the historical range of variability (HRV) at the site. We found no substantial difference in frequency of debris flows cataloged at eleven sites of deposition between the east (8) and west (11) sides of the Colorado River valley over the last century, but four of the five largest debris flows originated on the west side of the valley in association with the earthen ditch, while the fifth is on a steep hillslope of hydrothermally altered rock on the east side. These results suggest that the ditch has altered the regime of debris flow activity in the Colorado River headwaters as compared to HRV by increasing the frequency of debris flows large enough to reach the Colorado River valley. Valley confinement is a dominant control on response to debris flows, influencing volumes of aggradation and persistence of debris flow deposits. Large, frequent debris flows, exceeding HRV, create persistent effects due to valley geometry and geomorphic setting conducive to sediment storage that are easily delineated by valley confinement ratios which are useful to land managers.

  9. Debris Flow Occurrence and Sediment Persistence, Upper Colorado River Valley, CO

    NASA Astrophysics Data System (ADS)

    Grimsley, K. J.; Rathburn, S. L.; Friedman, J. M.; Mangano, J. F.

    2016-07-01

    Debris flow magnitudes and frequencies are compared across the Upper Colorado River valley to assess influences on debris flow occurrence and to evaluate valley geometry effects on sediment persistence. Dendrochronology, field mapping, and aerial photographic analysis are used to evaluate whether a 19th century earthen, water-conveyance ditch has altered the regime of debris flow occurrence in the Colorado River headwaters. Identifying any shifts in disturbance processes or changes in magnitudes and frequencies of occurrence is fundamental to establishing the historical range of variability (HRV) at the site. We found no substantial difference in frequency of debris flows cataloged at eleven sites of deposition between the east (8) and west (11) sides of the Colorado River valley over the last century, but four of the five largest debris flows originated on the west side of the valley in association with the earthen ditch, while the fifth is on a steep hillslope of hydrothermally altered rock on the east side. These results suggest that the ditch has altered the regime of debris flow activity in the Colorado River headwaters as compared to HRV by increasing the frequency of debris flows large enough to reach the Colorado River valley. Valley confinement is a dominant control on response to debris flows, influencing volumes of aggradation and persistence of debris flow deposits. Large, frequent debris flows, exceeding HRV, create persistent effects due to valley geometry and geomorphic setting conducive to sediment storage that are easily delineated by valley confinement ratios which are useful to land managers.

  10. Debris Flow Occurrence and Sediment Persistence, Upper Colorado River Valley, CO.

    PubMed

    Grimsley, K J; Rathburn, S L; Friedman, J M; Mangano, J F

    2016-07-01

    Debris flow magnitudes and frequencies are compared across the Upper Colorado River valley to assess influences on debris flow occurrence and to evaluate valley geometry effects on sediment persistence. Dendrochronology, field mapping, and aerial photographic analysis are used to evaluate whether a 19th century earthen, water-conveyance ditch has altered the regime of debris flow occurrence in the Colorado River headwaters. Identifying any shifts in disturbance processes or changes in magnitudes and frequencies of occurrence is fundamental to establishing the historical range of variability (HRV) at the site. We found no substantial difference in frequency of debris flows cataloged at eleven sites of deposition between the east (8) and west (11) sides of the Colorado River valley over the last century, but four of the five largest debris flows originated on the west side of the valley in association with the earthen ditch, while the fifth is on a steep hillslope of hydrothermally altered rock on the east side. These results suggest that the ditch has altered the regime of debris flow activity in the Colorado River headwaters as compared to HRV by increasing the frequency of debris flows large enough to reach the Colorado River valley. Valley confinement is a dominant control on response to debris flows, influencing volumes of aggradation and persistence of debris flow deposits. Large, frequent debris flows, exceeding HRV, create persistent effects due to valley geometry and geomorphic setting conducive to sediment storage that are easily delineated by valley confinement ratios which are useful to land managers.

  11. Technology push, market pull, and the Valley of Death

    NASA Astrophysics Data System (ADS)

    Swift, Gregory W.

    2005-09-01

    The Valley of Death is the gap between fundamental research and product development, where apparently promising technologies can stall or disappear. Fundamental researchers may hope for potential applications of their work, and they try to push technology based on their research. Businesses may hope that new technology might serve their market needs, and they try to find promising new technologies that can be pulled toward practical use. The valley between the researchers and the businesses can be surprisingly twisted and thorny, despite government attempts to build roads across it. The histories of cryogenic engineering in the late 20th century and of thermoacoustics work at Los Alamos offer examples of both useful and misguided strategies in this valley. Although global thermoacoustics R&D has not (yet?) been as successful as cryogenic engineering, thermoacoustics has thus far avoided some of the worst pitfalls in the valley.

  12. Decentralization and equity of resource allocation: evidence from Colombia and Chile.

    PubMed Central

    Bossert, Thomas J.; Larrañaga, Osvaldo; Giedion, Ursula; Arbelaez, José Jesus; Bowser, Diana M.

    2003-01-01

    OBJECTIVE: To investigate the relation between decentralization and equity of resource allocation in Colombia and Chile. METHODS: The "decision space" approach and analysis of expenditures and utilization rates were used to provide a comparative analysis of decentralization of the health systems of Colombia and Chile. FINDINGS: Evidence from Colombia and Chile suggests that decentralization, under certain conditions and with some specific policy mechanisms, can improve equity of resource allocation. In these countries, equitable levels of per capita financial allocations at the municipal level were achieved through different forms of decentralization--the use of allocation formulae, adequate local funding choices and horizontal equity funds. Findings on equity of utilization of services were less consistent, but they did show that increased levels of funding were associated with increased utilization. This suggests that improved equity of funding over time might reduce inequities of service utilization. CONCLUSION: Decentralization can contribute to, or at least maintain, equitable allocation of health resources among municipalities of different incomes. PMID:12751417

  13. Etiologic agent of an epidemic of cutaneous leishmaniasis in Tolima, Colombia.

    PubMed

    Rodríguez-Barraquer, Isabel; Góngora, Rafael; Prager, Martín; Pacheco, Robinson; Montero, Luz Mery; Navas, Adriana; Ferro, Cristina; Miranda, Maria Consuelo; Saravia, Nancy G

    2008-02-01

    American cutaneous leishmaniasis (ACL) has been characterized as a zoonotic disease. However, peridomestic and domestic transmission have been recorded in at least nine countries in Central and South America. The present study was undertaken to identify the etiologic agent of a peridomestic epidemic of ACL in the Department of Tolima, Colombia. Leishmania isolates were obtained during the diagnosis of 56 patients with ACL who consulted the local leishmaniasis control program in three municipalities in Tolima. Species were identified using monoclonal antibodies and isoenzyme electrophoresis. A total of 53 (94.6%) of 56 isolates were identified as Leishmania (Viannia) guyanensis. Three isolates (5.4%) were identified as L. (V.) panamensis. Leishmania (V.) guyanensis is the probable etiologic agent of the largest epidemic of cutaneous leishmaniasis recorded in Colombia. This species has not previously been reported outside the Amazon and southeastern regions of Colombia, and has not been described in the peridomestic setting or linked with an epidemic.

  14. A shore-based preliminary survey of marine ribbon worms (Nemertea) from the Caribbean coast of Colombia

    PubMed Central

    Gonzalez-Cueto, Jaime; Quiroga, Sigmer; Norenburg, Jon

    2014-01-01

    Abstract A checklist of benthic ribbon worm species from the Caribbean coast of Colombia is presented, including synonyms, distributions, a photographic record, and the main morphologic characters of each species for a rapid identification. This is the first research focused broadly on nemerteans in Colombia. 54 specimens of nemerteans were hand-collected from the rocky littoral of two different localities, and identified according to personal experience and specialist literature. 13 species were found; of which 11 represent new records for the country. These species belong to eight different traditionally used families: Tubulanidae, Valenciniidae, Lineidae, Amphiporidae, Cratenemertidae, Emplectonematidae, Drepanophoridae and Ototyphlonemertidae. The most common and abundant species was Dushia atra. The biodiversity of nemerteans in Colombia seems to overlap with the nemertean fauna from Florida and Brazil, explained by the convergence of the North Brazil Current, Guiana Current, Caribbean Currents and the Panama-Colombia Contracurrent in the sampled region. The results of this work suggest that the Caribbean coast of Colombia is a region with a high diversity of nemerteans, and provide important taxonomic data for environmental assessments and future biological research. PMID:25317057

  15. A new species and new records of Cryptodacus (Diptera: Tephritidae) from Colombia, Bolivia and Peru

    USDA-ARS?s Scientific Manuscript database

    Cryptodacus bernardoi Rodriguez & Rodriguez, new species, is described from Colombia. It was reared from fruits of Phoradendron sp. near piperoides (Kunth) Trel. New distribution records are reported for Cryptodacus ornatus Norrbom from Colombia and Peru, for Cryptodacus trinotatus Norrbom & Korytko...

  16. Male-only clinics: a success story in Colombia.

    PubMed

    Goldman, R

    1987-04-01

    2 male-only reproductive health clinics in Colombia are refuting the stereotype that Latin American men reject vasectomy as a threat to their machismo image and consider birth control to be a woman's responsibility. Over 1000 vasectomies were performed in the 2 clinics in Bogota and Medellin in 1986. The clinics are operated by PROFAMILIA and supported by the Association for Voluntary Surgical Contraception. Information about these male-only clinics is dispersed through radio announcements, magazine advertisements, and newspaper articles. The cost of services at these clinics is 50% less than services provided at other family facilities. These clinics demonstrate that Colombian men are willing to share family planning responsibilities if services are offered in a manner respectful of their needs. 3 additional male-only clinics are scheduled to open in Colombia in 1987.

  17. Gravity survey and depth to bedrock in Carson Valley, Nevada-California

    USGS Publications Warehouse

    Maurer, D.K.

    1985-01-01

    Gravity data were obtained from 460 stations in Carson Valley, Nevada and California. The data have been interpreted to obtain a map of approximate depth to bedrock for use in a ground-water model of the valley. This map delineates the shape of the alluvium-filled basin and shows that the maximum depth to bedrock exceeds 5,000 feet, on the west side of the valley. A north-south trending offset in the bedrock surface shows that the Carson-Valley/Pine-Nut-Mountain block has not been tilted to the west as a simple unit, but is comprised of several smaller blocks. (USGS)

  18. Dry Valley streams in Antarctica: Ecosystems waiting for water

    USGS Publications Warehouse

    McKnight, Diane M.; Niyogi, D.K.; Alger, A.S.; Bomblies, A.; Conovitz, P.A.; Tate, C.M.

    1999-01-01

    An axiom of ecology is: 'Where there is water, there is life.' In dry valley ecosystems of Antarctica, this axiom can be extended to: 'Where there has been and will be water, there is life.' Stream communities in the dry valleys can withstand desiccation on an annual basis and also for longer periods - as much as decades or even centuries. These intact ecosystems, consisting primarily of cyanobacteria and eukaryotic algae, spring back to life with the return of water. Soil organisms in the dry valleys also have remarkable survival capabilities (Virginia and Wall 1999), emerging from dormancy with the arrival of water. Streams in the dry valleys carry meltwater from a glacier or ice-field source to the lakes on the valley floors and generally flow for 4-10 weeks during the summer, depending on climatic conditions. Many of these streams contain abundant algal mats that are perennial in the sense that they are in a freeze-dried state during the winter and begin growing again within minutes of becoming wetted by the first flow of the season. The algal species present in the streams are mainly filamentous cyanobacteria (approximately 20 species of the genera Phormidium, Oscillatoria, and Nostoc), two green algal species of the genus Prasiola, and numerous diatom taxa that are characteristic of soil habitats and polar regions. Algal abundances are greatest in those streams in which periglacial processes, acting over periods of perhaps a century, have produced a stable stone pavement in the streambed. This habitat results in a less turbulent flow regime and limits sediment scour from the streambed. Because dry valley glaciers advance and retreat over periods of centuries and millennia and stream networks in the dry valleys evolve through sediment deposition and transport, some of the currently inactive stream channels may receive flow again in the future. Insights- into the process of algal persistence and reactivation will come from long-term experiments that study the

  19. First evidence of the Hepatitis E virus in environmental waters in Colombia

    PubMed Central

    Baez, Paula A.; Lopez, Maria Camila; Duque-Jaramillo, Alejandra; Pelaez, Dioselina; Molina, Francisco; Navas, Maria-Cristina

    2017-01-01

    Hepatitis E virus (HEV) is one of the main causes of acute viral hepatitis of enteric transmission. HEV has been detected in environmental samples in several countries from Europe and Asia, constituting a risk factor for waterborne infection. In Colombia, HEV has been identified in samples obtained from patients as well as from swine, but no environmental studies have been carried out. To determine if HEV is present in environmental waters, samples from the main source of drinking water plant and of wastewater system of eight municipalities and two villages of Antioquia state (North West Colombia), were collected between December 2012 and April 2014. The HEV genome was detected by RT-PCR in 23.3% (7/30) of the samples from the main source of drinking water plants and in 16.7% (5/30) from sewage. Viral concentrates obtained from three positive sewage samples were used to inoculate HepG2 cell cultures that were followed for one month; however, the viral genome was not detected in any cell culture. This study demonstrates the circulation of HEV in both source of drinking water plants and wastewater in Antioquia state, Colombia. The presence of HEV in environmental waters could be a risk for waterborne transmission in this population. The findings of the present study, together with the evidence of HEV circulation in human and swine in Colombia, should be consider by public health authorities for the development of surveillance programs and the inclusion of HEV infection diagnosis in the guidelines of viral hepatitis in the country. This is the first report of HEV in environmental samples in Colombia and the second one in Latin America. PMID:28520759

  20. [Death by homicide in Colombia and Mexico: magnitude and trends, 2000-2011].

    PubMed

    Dávila-Cervantes, Claudio Alberto; Pardo-Montaño, Ana Melisa

    2014-07-01

    To quantify the magnitude and explain the trends and impact of death by homicide in Colombia and Mexico between 2000 and 2011 at the national level and by sex. Data were obtained from national homicide statistics (Departamento Administrativo Nacional de Estadística [DANE], Colombia; and Instituto Nacional de Estadística y Geografía [INEGI], Mexico). Standardized death rates and years of life lost (YLL) were calculated (the latter assuming zero mortality) in people 15–49 years old. In Colombia, between 2000 and 2002, deaths by homicide increased from 71.3 to 76.7 per 100 000 (7.5%); by 2011 this figure had fallen to 36.1. YLL in the same period increased to 0.58 years overall, reducing temporary life expectancy by one year in men and 0.1 years in women. Between 2002 and 2011, YLL was 0.45 years in both sexes: 0.83 in men and 0.07 in women. This decline occurred mainly in persons over 45 years of age. In Mexico, between 2000 and 2007, homicide rates fell from 10.8 to 8.2 per 100,000 and YLL dropped by 24%. Between 2008 and 2011, mortality and YLL increased significantly in both sexes (191.2% and 164.5%, respectively), reducing life expectancy by 0.39 years in men and 0.04 years in women. It was corroborated that there has been a decline in deaths by homicide in Colombia and a significant rise in Mexico after a period of continuous reduction. Numerous actions should be taken to continue reducing homicides in Colombia and to reverse the current trend in Mexico.

  1. First evidence of the Hepatitis E virus in environmental waters in Colombia.

    PubMed

    Baez, Paula A; Lopez, Maria Camila; Duque-Jaramillo, Alejandra; Pelaez, Dioselina; Molina, Francisco; Navas, Maria-Cristina

    2017-01-01

    Hepatitis E virus (HEV) is one of the main causes of acute viral hepatitis of enteric transmission. HEV has been detected in environmental samples in several countries from Europe and Asia, constituting a risk factor for waterborne infection. In Colombia, HEV has been identified in samples obtained from patients as well as from swine, but no environmental studies have been carried out. To determine if HEV is present in environmental waters, samples from the main source of drinking water plant and of wastewater system of eight municipalities and two villages of Antioquia state (North West Colombia), were collected between December 2012 and April 2014. The HEV genome was detected by RT-PCR in 23.3% (7/30) of the samples from the main source of drinking water plants and in 16.7% (5/30) from sewage. Viral concentrates obtained from three positive sewage samples were used to inoculate HepG2 cell cultures that were followed for one month; however, the viral genome was not detected in any cell culture. This study demonstrates the circulation of HEV in both source of drinking water plants and wastewater in Antioquia state, Colombia. The presence of HEV in environmental waters could be a risk for waterborne transmission in this population. The findings of the present study, together with the evidence of HEV circulation in human and swine in Colombia, should be consider by public health authorities for the development of surveillance programs and the inclusion of HEV infection diagnosis in the guidelines of viral hepatitis in the country. This is the first report of HEV in environmental samples in Colombia and the second one in Latin America.

  2. Imaging of pure spin-valley diffusion current in WS2-WSe2 heterostructures

    NASA Astrophysics Data System (ADS)

    Jin, Chenhao; Kim, Jonghwan; Utama, M. Iqbal Bakti; Regan, Emma C.; Kleemann, Hans; Cai, Hui; Shen, Yuxia; Shinner, Matthew James; Sengupta, Arjun; Watanabe, Kenji; Taniguchi, Takashi; Tongay, Sefaattin; Zettl, Alex; Wang, Feng

    2018-05-01

    Transition metal dichalcogenide (TMDC) materials are promising for spintronic and valleytronic applications because valley-polarized excitations can be generated and manipulated with circularly polarized photons and the valley and spin degrees of freedom are locked by strong spin-orbital interactions. In this study we demonstrate efficient generation of a pure and locked spin-valley diffusion current in tungsten disulfide (WS2)–tungsten diselenide (WSe2) heterostructures without any driving electric field. We imaged the propagation of valley current in real time and space by pump-probe spectroscopy. The valley current in the heterostructures can live for more than 20 microseconds and propagate over 20 micrometers; both the lifetime and the diffusion length can be controlled through electrostatic gating. The high-efficiency and electric-field–free generation of a locked spin-valley current in TMDC heterostructures holds promise for applications in spin and valley devices.

  3. Gender and Cooperation in Children: Experiments in Colombia and Sweden

    PubMed Central

    Cárdenas, Juan-Camilo; Dreber, Anna; von Essen, Emma; Ranehill, Eva

    2014-01-01

    In this article we compare cooperation among Colombian and Swedish children aged 9–12. We illustrate the dynamics of the prisoner's dilemma in a new task that is easily understood by children and performed during a physical education class. We find no robust evidence of a difference in cooperation between Colombia and Sweden overall. However, Colombian girls cooperate less than Swedish girls. We also find indications that girls in Colombia are less cooperative than boys. Finally, there is also a tendency for children to be more cooperative with boys than with girls on average. PMID:24614513

  4. Large, valley-exclusive Bloch-Siegert shift in monolayer WS2

    NASA Astrophysics Data System (ADS)

    Sie, Edbert J.; Lui, Chun Hung; Lee, Yi-Hsien; Fu, Liang; Kong, Jing; Gedik, Nuh

    2017-03-01

    Coherent interaction with off-resonance light can be used to shift the energy levels of atoms, molecules, and solids. The dominant effect is the optical Stark shift, but there is an additional contribution from the so-called Bloch-Siegert shift that has eluded direct and exclusive observation in solids. We observed an exceptionally large Bloch-Siegert shift in monolayer tungsten disulfide (WS2) under infrared optical driving. By controlling the light helicity, we could confine the Bloch-Siegert shift to occur only at one valley, and the optical Stark shift at the other valley, because the two effects obey opposite selection rules at different valleys. Such a large and valley-exclusive Bloch-Siegert shift allows for enhanced control over the valleytronic properties of two-dimensional materials.

  5. Returns to Education in Bogota, Colombia.

    ERIC Educational Resources Information Center

    Schultz, T. P.

    This memorandum derives estimates of the private rate of return to schooling for men and women based on a 1965 labor force survey, past cross-sectional data, and the long-term educational public policy of Bogota, Colombia. Here resources may be viewed as an investment in the future productive capacity of people. Depending on the costs and benefits…

  6. Groundwater quality in the Owens Valley, California

    USGS Publications Warehouse

    Dawson, Barbara J. Milby; Belitz, Kenneth

    2012-01-01

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Owens Valley is one of the study areas being evaluated. The Owens study area is approximately 1,030 square miles (2,668 square kilometers) and includes the Owens Valley groundwater basin (California Department of Water Resources, 2003). Owens Valley has a semiarid to arid climate, with average annual rainfall of about 6 inches (15 centimeters). The study area has internal drainage, with runoff primarily from the Sierra Nevada draining east to the Owens River, which flows south to Owens Lake dry lakebed at the southern end of the valley. Beginning in the early 1900s, the City of Los Angeles began diverting the flow of the Owens River to the Los Angeles Aqueduct, resulting in the evaporation of Owens Lake and the formation of the current Owens Lake dry lakebed. Land use in the study area is approximately 94 percent (%) natural, 5% agricultural, and 1% urban. The primary natural land cover is shrubland. The largest urban area is the city of Bishop (2010 population of 4,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to the Owens Lake dry lakebed. The primary aquifers in Owens Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database

  7. Late Cenozoic surficial deposits and valley evolution of unglaciated northern New Jersey

    USGS Publications Warehouse

    Stanford, S.D.

    1993-01-01

    Multiple alluvial, colluvial, and eolian deposits in unglaciated northern New Jersey, and the eroded bedrock surfaces on which they rest, provide evidence of both long-term valley evolution driven by sustained eustatic baselevel lowering and short-term filling and excavation of valleys during glacial and interglacial climate cycles. The long-term changes occur over durations of 106 years, the short-term features evolve over durations of 104 to 105 years. Direct glacial effects, including blockage of valleys by glacial ice and sediment, and valley gradient reversals induced by crustal depression, are relatively sudden changes that account for several major Pleistocene drainage shifts. After deposition of the Beacon Hill fluvial gravel in the Late Miocene, lowering of sea level, perhaps in response to growth of the Antarctic ice sheet, led to almost complete dissection of the gravel. A suite of alluvial, colluvial, and eolian sediments was deposited in the dissected landscape. The fluvial Bridgeton Formation was deposited in the Raritan lowland, in the Amboy-Trenton lowland, and in the Delaware valley. Following southeastward diversion of the main Bridgeton river, perhaps during Late Pliocene or Early Pleistocene glaciation, northeastward drainage was established on the inactive Bridgeton fluvial plain. About 30 to 45 m of entrenchment followed, forming narrow, incised valleys within which Late Pleistocene deposits rest. This entrenchment may have occurred in response to lowered sea level caused by growth of ice sheets in the northern hemisphere. Under periglacial conditions in the Middle and Late Pleistocene, valleys were partially filled with alluvium and colluvium. During interglacials slopes were stabilized by vegetation and the alluvial and colluvial valley-fill was excavated by gullying, bank erosion, and spring sapping. During Illinoian and late Wisconsinan glaciation, the lower Raritan River was diverted when glacial deposits blocked its valley, and the

  8. Hydrologic reconnaissance of Grouse Creek valley, Box Elder County, Utah

    USGS Publications Warehouse

    Hood, J.W.; Price, Don

    1970-01-01

    This report is the seventh in a series by the U. S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, which describes water resources of the western basins of Utah. Its purpose is to present available hydrologic data on Grouse Creek valley, to provide an evaluation of the potential water-resource development of the valley, and to identify studies that would help provide a better understanding of the valley's water supply

  9. Ground water in Fountain and Jimmy Camp Valleys, El Paso County, Colorado with a section on Computations of drawdowns caused by the pumping of wells in Fountain Valley

    USGS Publications Warehouse

    Jenkins, Edward D.; Glover, Robert E.

    1964-01-01

    The part of Fountain Valley considered in this report extends from Colorado Springs to the Pueblo County line. It is 23 miles long and has an area of 26 square miles. The part of Jimmy Camp Valley discussed is 11 miles long and has an area of 9 square miles. The topography is characterized by level flood plains and alluvial terraces that parallel the valley and by rather steep hills along the valley sides. The climate is semiarid, average annual precipitation being about 13 inches. Farming and stock raising are the principal occupations in the valleys; however, some of the agricultural land near Colorado Springs is being used for housing developments. The Pierre Shale and alluvium underlie most of the area, and mesa gravel caps the shale hills adjacent to Fountain Valley. The alluvium yields water to domestic, stock, irrigation, and public-supply wells and is capable of yielding large quantities of water for intermittent periods. Several springs issue along the sides of the valley at the contact of the mesa gravel and the underlying Pierre Shale. The water table ranges in depth from less than 10 feet along the bottom lands to about 80 feet along the sides of the valleys; the saturated thickness ranges from less than a foot to about 50 feet. The ground-water reservoir in Fountain Valley is recharged by precipitation that falls within the area, by percolation from Fountain Creek, which originates in the Pikes Peak, Monument Valley, and Rampart Range areas, and by seepage from irrigation water. This reservoir contains about 70,000 acre-feet of ground water in storage. The ground-water reservoir in Jimmy Camp Valley is recharged from precipitation that falls within the area, by percolation from Jimmy Camp Creek during periods of streamflow, and by seepage from irrigation water. The Jimmy Camp ground-water reservoir contains about 25,000 acre-feet of water in storage. Ground water is discharged from the area by movement to the south, by evaporation and transpiration in

  10. Valley-chiral quantum Hall state in graphene superlattice structure

    NASA Astrophysics Data System (ADS)

    Tian, H. Y.; Tao, W. W.; Wang, J.; Cui, Y. H.; Xu, N.; Huang, B. B.; Luo, G. X.; Hao, Y. H.

    2016-05-01

    We theoretically investigate the quantum Hall effect in a graphene superlattice (GS) system, in which the two valleys of graphene are coupled together. In the presence of a perpendicular magnetic field, an ordinary quantum Hall effect is found with the sequence σxy=ν e^2/h(ν=0,+/-1,+/-2,\\cdots) . At the zeroth Hall platform, a valley-chiral Hall state stemming from the single K or K' valley is found and it is localized only on one sample boundary contributing to the longitudinal conductance but not to the Hall conductivity. Our findings may shed light on the graphene-based valleytronics applications.

  11. Civil Information Management in Support of Counterinsurgency Operations: A Case for the Use of Geospatial Information Systems in Colombia

    DTIC Science & Technology

    2006-05-25

    desempeño económico en las áreas rurales. Bogotá: Universidad Externado de Colombia & Fondo Financiero de Proyectos de Desarrollo. 1997. Bilyeu, Elisabeth...Ediciones B Colombia, S.A.. 2004. Presidencia República de Colombia. Plan Nacional de Desarrollo 2002-2006: Hacia un Estado Comunitario. Bogotá

  12. Valley-selective photon-dressed states in transition metal dichalcogenides

    NASA Astrophysics Data System (ADS)

    LaMountain, Trevor; Chen, Yen-Jung; Stanev, Teodor K.; Stern, Nathaniel P.

    2018-02-01

    When electronic excitations in a semiconductor interact with light, the relevant quasiparticles are hybrid lightmatter dressed states, or exciton-polaritons. In monolayer transition metal dichalcogenides, a class of 2D direct bandgap semiconductors, optical excitations selectively populate distinct momentum valleys with correlated spin projection. The combination of this spin-valley locking with photon dressed states can lead to new optical phenomena in these materials. We present spectroscopic measurements of valley-specific exciton-polaritons in monolayer 2D materials in distinct regimes. When a monolayer is embedded in a dielectric microcavity, strong coupling exciton-polaritons are achieved. Cavity-modified dynamics of the dressed states are inferred from emission. Polarization persists up to room temperature in monolayer MoS2, in contrast with bare material. We also show that distinct regimes of valley-polarized exciton-polaritons can be accessed with microcavity engineering by tuning system parameters such as cavity decay rate and exciton-photon coupling strength. Further, we report results showing that polarization-sensitive ultrafast spectroscopy can enable sensitive measurements of the valley optical Stark shift, a light-induced dressed state energy shift, in monolayer semiconductors such as WSe2 and MoS2. These findings demonstrate distinct approaches to manipulating the picosecond dynamics of valleysensitive dressed states in monolayer semiconductors.

  13. Aeromagnetic survey map of Sacramento Valley, California

    USGS Publications Warehouse

    Langenheim, Victoria E.

    2015-01-01

    Three aeromagnetic surveys were flown to improve understanding of the geology and structure in the Sacramento Valley. The resulting data serve as a basis for geophysical interpretations, and support geological mapping, water and mineral resource investigations, and other topical studies. Local spatial variations in the Earth's magnetic field (evident as anomalies on aeromagnetic maps) reflect the distribution of magnetic minerals, primarily magnetite, in the underlying rocks. In many cases the volume content of magnetic minerals can be related to rock type, and abrupt spatial changes in the amount of magnetic minerals commonly mark lithologic or structural boundaries. Bodies of serpentinite and other mafic and ultramafic rocks tend to produce the most intense positive magnetic anomalies (for example, in the northwest part of the map). These rock types are the inferred sources, concealed beneath weakly magnetic, valley-fill deposits, of the most prominent magnetic features in the map area, the magnetic highs that extend along the valley axis. Cenozoic volcanic rocks are also an important source of magnetic anomalies and coincide with short-wavelength anomalies that can be either positive (strong central positive anomaly flanked by lower-amplitude negative anomalies) or negative (strong central negative anomaly flanked by lower-amplitude positive anomalies), reflecting the contribution of remanent magnetization. Rocks with more felsic compositions or even some sedimentary units also can cause measurable magnetic anomalies. For example, the long, linear, narrow north-trending anomalies (with amplitudes of <50 nanoteslas [nT]) along the western margin of the valley coincide with exposures of the Mesozoic Great Valley sequence. Note that isolated, short-wavelength anomalies, such as those in the city of Sacramento and along some of the major roads, are caused by manmade features.

  14. Structural superposition in fault systems bounding Santa Clara Valley, California

    USGS Publications Warehouse

    Graymer, Russell W.; Stanley, Richard G.; Ponce, David A.; Jachens, Robert C.; Simpson, Robert W.; Wentworth, Carl M.

    2015-01-01

    Santa Clara Valley is bounded on the southwest and northeast by active strike-slip and reverse-oblique faults of the San Andreas fault system. On both sides of the valley, these faults are superposed on older normal and/or right-lateral normal oblique faults. The older faults comprised early components of the San Andreas fault system as it formed in the wake of the northward passage of the Mendocino Triple Junction. On the east side of the valley, the great majority of fault displacement was accommodated by the older faults, which were almost entirely abandoned when the presently active faults became active after ca. 2.5 Ma. On the west side of the valley, the older faults were abandoned earlier, before ca. 8 Ma and probably accumulated only a small amount, if any, of the total right-lateral offset accommodated by the fault zone as a whole. Apparent contradictions in observations of fault offset and the relation of the gravity field to the distribution of dense rocks at the surface are explained by recognition of superposed structures in the Santa Clara Valley region.

  15. 75 FR 27494 - Proposed Amendment of Class E Airspace; Pauls Valley, OK

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-17

    ... 0182; Airspace Docket No. 10-ASW-4] Proposed Amendment of Class E Airspace; Pauls Valley, OK AGENCY... action proposes to amend Class E airspace at Pauls Valley, OK. Additional controlled airspace is necessary to accommodate new Standard Instrument Approach Procedures (SIAPs) at Pauls Valley Municipal...

  16. The McMurdo Dry Valleys: A landscape on the threshold of change

    NASA Astrophysics Data System (ADS)

    Fountain, Andrew G.; Levy, Joseph S.; Gooseff, Michael N.; Van Horn, David

    2014-11-01

    Field observations of coastal and lowland regions in the McMurdo Dry Valleys suggest they are on the threshold of rapid topographic change, in contrast to the high elevation upland landscape that represents some of the lowest rates of surface change on Earth. A number of landscapes have undergone dramatic and unprecedented landscape changes over the past decade including, the Wright Lower Glacier (Wright Valley) - ablated several tens of meters, the Garwood River (Garwood Valley) has incised > 3 m into massive ice permafrost, smaller streams in Taylor Valley (Crescent, Lawson, and Lost Seal Streams) have experienced extensive down-cutting and/or bank undercutting, and Canada Glacier (Taylor Valley) has formed sheer, > 4 meter deep canyons. The commonality between all these landscape changes appears to be sediment on ice acting as a catalyst for melting, including ice-cement permafrost thaw. We attribute these changes to increasing solar radiation over the past decade despite no significant trend in summer air temperature. To infer possible future landscape changes in the McMurdo Dry Valleys, due to anticipated climate warming, we map ‘at risk’ landscapes defined as those with buried massive ice in relative warm regions of the valleys. Results show that large regions of the valley bottoms are ‘at risk’. Changes in surface topography will trigger important responses in hydrology, geochemistry, and biological community structure and function.

  17. Water resources of Beaver Valley, Utah

    USGS Publications Warehouse

    Lee, Willis Thomas

    1908-01-01

    Location and extent of area examined. Beaver Valley is located in Beaver County, in southwestern Utah, about 175 miles south of Salt Lake. It lies between the Tushar Mountains on the east and the Beaver Mountains on the west. The principal town of the valley is Beaver, which is most conveniently reached from Milford, a station on the San Pedro, Los Angeles and Salt Lake Railroad. The valley, together with its neighboring highlands, occupies the eastern third of Beaver County, an area of about 1,200 square miles. A large part of this area, however, is rocky upland and unproductive desert, the tillable land comprising a comparatively small area in the immediate vicinity of the streams.Purpose and scope of work. The purpose of this paper is to present information concerning the waters of Beaver Valley and to point out ways and means of increasing their usefulness. The presence of a large amount of water in Beaver Valley results from local topograhic conditions, the water being supplied by precipitation in the highland to the east. Its conservation and distribution result from geologic conditions, the water being held in loose gravel and sand, which are more or less confined between ridges of consolidated rocks. The rock basins were formed partly by erosion and partly by faulting and surface deformation. In order to accomplish the purpose in view it is therefore necessary to describe the geographic and geologic conditions in Beaver Valley and neighboring regions.The investigation included the determination of the flow of streams and springs, of the manner of occurrence and quantity of the underground waters as shown by the geologic and geographic conditions of the region and by the distribution of springs and wells, and of the chemical character of the waters with reference to their adaptability to domestic use and to irrigation. The chemical data were obtained (a) by field assays, which are approximately correct and probably of sufficient accuracy to be of value in

  18. 10. VIEW OF YAKIMA VALLEY TRANSPORTATION COMPANY AND UNION PACIFIC ...

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

    10. VIEW OF YAKIMA VALLEY TRANSPORTATION COMPANY AND UNION PACIFIC RAILROAD INTERCHANGE TRACKS AT YAKIMA - Yakima Valley Transportation Company Interurban Railroad, Connecting towns of Yakima, Selah & Wiley City, Yakima, Yakima County, WA

  19. Patterns of Rift Valley fever activity in Zambia.

    PubMed Central

    Davies, F. G.; Kilelu, E.; Linthicum, K. J.; Pegram, R. G.

    1992-01-01

    An hypothesis that there was an annual emergence of Rift Valley fever virus in Zambia, during or after the seasonal rains, was examined with the aid of sentinel cattle. Serum samples taken during 1974 and 1978 showed evidence of epizootic Rift Valley fever in Zambia, with more than 80% positive. A sentinel herd exposed from 1982 to 1986 showed that some Rift Valley fever occurred each year. This was usually at a low level, with 3-8% of the susceptible cattle seroconverting. In 1985-6 more than 20% of the animals seroconverted, and this greater activity was associated with vegetational changes--which could be detected by remote-sensing satellite imagery--which have also been associated with greater virus activity in Kenya. PMID:1547835

  20. New records of Anastrepha (Diptera: Tephritidae) primarily from Colombia.

    PubMed

    Clavijo, Pedro Alexander Rodriguez; Norrbom, Allen L; PeÑaranda, Emilio arÉvalo; Tehran, Francisco Balseiro; DÍaz, Paula Andrea; Benitez, Maria Clara; Gallego, Jeisson; Cruz, Maria Isabel; Montes, JosÉ M; Rodriguez, Erick J; Steck, Gary J; Sutton, Bruce D; Ramos, Elizabeth Quisberth; SÁnchez, Juan josÉ Lagrava; Colque, Freddy

    2018-03-06

    New distribution information, primarily from Colombia, is provided for 60 species of Anastrepha, including the first records of 33 species from Colombia: A. acca Norrbom, A. acris Stone, A. amita Zucchi, A. amplidentata Norrbom, A. atrox (Aldrich), A. barbiellinii Lima, A. bezzii Lima, A. canalis Stone, A. cocorae Norrbom Korytkowski, A. compressa Stone, A. cordata Aldrich, A. crebra Stone, A. cryptostrepha Hendel, A. cryptostrephoides Norrbom Korytkowski, A. furcata Lima, A. fuscicauda Norrbom Korytkowski, A. galbina Stone, A. grandicarina Norrbom Korytkowski, A. hamata (Loew), A. katiyari Norrbom, A. macrura Hendel, A. margarita Caraballo, A. minuta Stone, A. nigripalpis Hendel, A. normalis Norrbom, A. pastranai Blanchard, A. pseudanomala Norrbom, A. pulchra Stone, A. similis Greene, A. speciosa Stone, A. urichi Greene, A. willei Korytkowski, and A. zuelaniae Stone. In addition, A. acris is reported from Costa Rica, A. alveata Stone from El Salvador, A. antunesi Lima and A. bahiensis Lima from Bolivia, A. barbiellinii from Trinidad Tobago, A. bezzii, A. canalis, A. coronilli Carrejo González, A. cryptostrepha and A. minuta from Bolivia, and A. willei from Argentina and Bolivia. A list of the 83 species of Anastrepha now known to occur in Colombia is provided, as well as illustrations of at least the wing and aculeus tip or male genitalia for 60 species.

  1. Bilingual Curriculum Construction and Empowerment in Colombia.

    ERIC Educational Resources Information Center

    de Mejia, Anne-Marie; Tejada, Harvey

    2003-01-01

    Traced development of a bilingual curriculum in a monolingual private school in Cali, Colombia, with particular reference to the creation of a curricular proposal in accord with the philosophy and expectations of the school community and the process of particular empowerment generated throughout the research. (Author/VWL)

  2. Switching effects and spin-valley Andreev resonant peak shifting in silicene superconductor

    NASA Astrophysics Data System (ADS)

    Soodchomshom, Bumned; Niyomsoot, Kittipong; Pattrawutthiwong, Eakkarat

    2018-03-01

    The magnetoresistance and spin-valley transport properties in a silicene-based NM/FB/SC junction are investigated, where NM, FB and SC are normal, ferromagnetic and s-wave superconducting silicene, respectively. In the FB region, perpendicular electric and staggered exchange fields are applied. The quasiparticles may be described by Dirac Bogoliubov-de Gennes equation due to Cooper pairs formed by spin-valley massive fermions. The spin-valley conductances are calculated based on the modified Blonder-Tinkham-Klapwijk formalism. We find the spin-valley dependent Andreev resonant peaks in the junction shifted by applying exchange field. Perfect conductance switch generated by interplay of intrinsic spin orbit interaction and superconducting gap has been predicted. Spin and valley polarizations are almost linearly dependent on biased voltage near zero bias and then turn into perfect switch at biased voltage approaching the superconducting gap. The perfect switching of large magnetoresistance has been also predicted at biased energy near the superconducting gap. These switching effects may be due to the presence of spin-valley Andreev resonant peak near the superconducting gap. Our work reveals potential of silicene as applications of electronic switching devices and linear control of spin and valley polarizations.

  3. The drink driving situation in Colombia.

    PubMed

    Castaño, Ramón

    2012-01-01

    To describe and analyze the drink driving situation in Colombia. The assessment was based on semistructured interviews of key stakeholders and analysis of secondary data. Road traffic crashes caused 5704 deaths and injured 39,318 people in 2010. The 3 main sources of crash data-forensic authorities, traffic authorities, and motor vehicle insurance agencies-provide different information about crashes, drivers, and victims, but they cannot be routinely merged. This together with the problem of identifying alcohol as the cause of a crash makes it difficult to estimate the role of drink driving in road crashes. In addition, reliable figures for the incidence of drink driving are not available from the random breath test programs because of sampling issues, underreporting, and missing data on negative results. However, it can be argued that alcohol plays a role in fatalities, because the proportion of crashes involving fatalities rises on weekends and between 12:00 a.m. and 05:59 a.m. when drink driving is likely to occur. Colombia has strict drink-drive laws that specify 3 levels of offense and sanctions (level I: 40- 99 mg/100 mL, level II: 100-149 mg/100 mL, and level III: 150 mg/100 mL or above). Drivers responsible for causing crashes with fatalities and injuries can be imprisoned under criminal law and sentences are increased by 50 to 100 percent if they test positive for alcohol. Enforcement includes random breath testing for alcohol, but its impact is weakened by the lack of a legal requirement to submit to a test and poor implementation of sanctions. There have been mass media campaigns against drink driving including one linked to a major enforcement initiative in 2008. However, there was a consensus that most campaigns were not focused sufficiently on increasing drivers' perceived risk of being caught. According to those interviewed, campaigns aimed at responsible consumption and the use of designated drivers appear to have had a growing positive effect, but

  4. Large tunable valley splitting in edge-free graphene quantum dots on boron nitride

    NASA Astrophysics Data System (ADS)

    Freitag, Nils M.; Reisch, Tobias; Chizhova, Larisa A.; Nemes-Incze, Péter; Holl, Christian; Woods, Colin R.; Gorbachev, Roman V.; Cao, Yang; Geim, Andre K.; Novoselov, Kostya S.; Burgdörfer, Joachim; Libisch, Florian; Morgenstern, Markus

    2018-05-01

    Coherent manipulation of the binary degrees of freedom is at the heart of modern quantum technologies. Graphene offers two binary degrees: the electron spin and the valley. Efficient spin control has been demonstrated in many solid-state systems, whereas exploitation of the valley has only recently been started, albeit without control at the single-electron level. Here, we show that van der Waals stacking of graphene onto hexagonal boron nitride offers a natural platform for valley control. We use a graphene quantum dot induced by the tip of a scanning tunnelling microscope and demonstrate valley splitting that is tunable from -5 to +10 meV (including valley inversion) by sub-10-nm displacements of the quantum dot position. This boosts the range of controlled valley splitting by about one order of magnitude. The tunable inversion of spin and valley states should enable coherent superposition of these degrees of freedom as a first step towards graphene-based qubits.

  5. Gravitational stresses in long symmetric ridges and valleys in anisotropic rock

    USGS Publications Warehouse

    Pan, E.; Amadei, B.; Savage, W.Z.

    1994-01-01

    The effect of topography and rock mass anisotropy on gravitational stresses in long isolated symmetric ridges and valleys is modeled using an analytical method proposed earlier by the first two authors. The rock mass deforms under a condition of plane strain. A parametric study is presented on the effect of (1) topography, (2) orientation of anisotropy and (3) degree of anisotropy on the magnitude and distribution of gravitational stresses in transversely isotropic rock masses with planes of anisotropy striking parallel to the ridge or valley axis. It is found that compressive stresses develop near ridge crests and that tensile stresses develop in valley bottoms and valley walls. The magnitude of the gravitational stresses is of the order of the characteristics stress ??{variant}g??b?? where ??{variant} is the rock density, g is the gravitational acceleration and ??b?? is the height of the ridge or depth of the valley. ?? 1994.

  6. 79. COVERED CONDUIT ACROSS ANTELOPE VALLEY WITH WIND FARM IN ...

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

    79. COVERED CONDUIT ACROSS ANTELOPE VALLEY WITH WIND FARM IN DISTANCE - Los Angeles Aqueduct, From Lee Vining Intake (Mammoth Lakes) to Van Norman Reservoir Complex (San Fernando Valley), Los Angeles, Los Angeles County, CA

  7. Erosional valleys in the Thaumasia region of Mars: Hydrothermal and seismic origins

    USGS Publications Warehouse

    Tanaka, K.L.; Dohm, J.M.; Lias, J.H.; Hare, T.M.

    1998-01-01

    Analysis of erosional valleys, geologic materials and features, and topography through time in the Thaumasia region of Mars using co-registered digital spatial data sets reveals significant associations that relate to valley origin. Valleys tend to originate (1) on Noachian to Early Hesperian (stages 1 and 2) large volcanoes, (2) within 50-100 km of stages 1 and 2 rift systems, and (3) within 100 km of Noachian (stage 1) impact craters >50 km in diameter. These geologic preferences explain observations of higher valley-source densities (VSDs) in areas of higher elevations and regional slopes (>1??) because the volcanoes, rifts, and craters form high, steep topography or occur in terrain of high relief. Other stage 1 and stage 2 high, steep terrains, however, do not show high VSDs. The tendency for valleys to concentrate near geologic features and the overall low drainage densities in Thaumasia compared to terrestrial surfaces rule out widespread precipitation as a major factor in valley formation (as is proposed in wann, wet climate scenarios) except perhaps during the Early Noachian, for which much of the geologic record has been obliterated. Instead, volcanoes and rifts may indicate the presence of shallow crustal intrusions that could lead to local hydrothermal circulation, melting of ground ice and snow, and groundwater sapping. However, impact-crater melt would provide a heat source at the surface that might drive away water, forming valleys in the process. Post-stage 1 craters mostly have low nearby VSDs, which, for valleys incised in older rocks, suggests burial by e??jecta and, for . younger valleys, may indicate desiccation of near-surface water and deepening of the cryosphere. Later Hesperian and Amazonian (stages 3 and 4) valleys originate within 100-200 km of three young, large impact craters and near rifts systems at Warrego Valle??s and the southern part of Coprates rise. These valleys likely developed when the cryosphere was a couple kilometers or

  8. [Discriminating concentrations for three insecticides used in public health in a Lutzomyia longipalpis experimental strain from Colombia].

    PubMed

    Marceló, Catalina; Cabrera, Olga Lucía; Santamaría, Erika

    2014-01-01

    In Colombia, periurban populations of Lutzomyia longipalpis , vector of the causative agent of visceral leishmaniasis in the upper and middle valley of the Magdalena River, may be exposed to insecticide applications with different purposes. Thus, it is important to begin a susceptibility surveillance of this species to insecticides. To determine indicators of susceptibility to three insecticides habitually used in public health, such as malathion, deltamethrin and lambda-cyhalothrin in an experimental strain of L. longipalpis . We used the method proposed by the Centers for Disease Control and Prevention. Groups of 10 to 15 unfed females were exposed to different concentrations of the insecticides using 250 ml glass bottles as test chambers. Mortality was registered every five minutes for an hour. Diagnostic concentrations and lethal times for each insecticide were calculated. In the evaluated L. longipalpis strain, the diagnostic concentrations and times were 75 µg/ml and 25 minutes for malathion, 10 µg/ml and 35 minutes for deltamethrin, and 15 µg/ml during 30 minutes for lambda-cyhalothrin. Baseline data over mortality response to three insecticides were established in a susceptibility strain of L. longipalpis vector. These indicators will allow establishing comparisons with populations of L. longipalpis exposed regularly or sporadically to chemical control measures to detect changes in their resistance to these insecticides.

  9. 3 CFR - Continuation of U. S. Drug Interdiction Assistance to the Government of Colombia

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 3 The President 1 2014-01-01 2014-01-01 false Continuation of U. S. Drug Interdiction Assistance to the Government of Colombia Presidential Documents Other Presidential Documents Presidential Determination No. 2013-12 of August 9, 2013 Continuation of U. S. Drug Interdiction Assistance to the Government of Colombia Memorandum for the Secretary o...

  10. 3 CFR - Continuation of U.S. Drug Interdiction Assistance to the Government of Colombia

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 3 The President 1 2012-01-01 2012-01-01 false Continuation of U.S. Drug Interdiction Assistance to the Government of Colombia Presidential Documents Other Presidential Documents Presidential Determination No. 2011-13 of August 10, 2011 Continuation of U.S. Drug Interdiction Assistance to the Government of Colombia Memorandum for the Secretary of...

  11. Colombia's Libraries: Modernizing amidst a Drug War.

    ERIC Educational Resources Information Center

    Chepesiuk, Ron

    1991-01-01

    Describes the impact that the war on drugs in Colombia has had on their library services and on the lives of professional librarians. Topics discussed include political, staffing, budget, resource, and physical plant problems; the serious shortage of professional librarians; and extending library service to rural areas. (LRW)

  12. Fuelling a National Innovation System in Colombia

    ERIC Educational Resources Information Center

    Lucio-Arias, Diana

    2006-01-01

    This presentation of the innovation-driven environment in Colombia derives from important national efforts to gather and store pertinent information. Two large surveys have tested the "innovative behaviour" of Colombian manufacturing firms--the more recent of these was in 2005. Another information source is the Scienti platform, an…

  13. Has Plan Colombia Ignored Neighboring Countries

    DTIC Science & Technology

    2008-06-01

    IGNORED NEIGHBORING COUNTRIES? Celso Andrade-Garzon Colonel, Ecuadorian Army, 1981 B.S., University of Loja , Ecuador , 1993 M.S., Institute of...neighboring countries of Ecuador and Venezuela, increasing border violence, population displacement and the creation of refugees, environmental damage...black market weapons trading and drug trafficking. This thesis uses trust and influence theory to analyze how Plan Colombia affects Ecuador and

  14. Malaria in Colombia: retrospective glance during the past 40 years.

    PubMed

    Valero-Bernal, María V

    2006-01-01

    Describe and analyze the structural configuration of malaria in Colombia since 1960 to 2004 where the phenomena of persistence, resurgence and resistance as well as the main determinants associated to these phenomena. A comparative study of the history of malaria and its trend was conducted in Colombia since 1960-2004. Secondary and primary information about the frequency and spatial distribution of malaria was collected. The sub period were identified according to institutional transformation and malaria control strategies as well as the socioeconomic and sociopolitical conjuncture factors in the country. The structural and situational analyses of malaria in Colombia shown a steadily increase in morbidity from an average API 2,19 x 1 000 in 1960-74 to 8,92 by 1994-2004. Since the middle 70's there has been a considerable reduction of mortality. The malaria case relation P. vivax vs. P. falciparum is 3 to 5, respectively. The Annual Positive Sample Rate increased during the same study periods from 3.96% to 29.93%. Unfortunately the Annual Blood Examination Rate-ABER decreased by fewer than 5%, instead of increase to minimum required for detection of malaria. During the National Eradication Malaria Service the malaria decreased steadily by the first five years, unfortunately the disease present resurgence, persistence after the reduction of financial and technical support from international health agencies in the middle seventies. Nowadays, around 85% of the territory, mainly rural areas are endemic for malaria. In spite of the transformation of the health system and different strategies implemented against malaria, it continues being one of the priorities in the public health services of Colombia.

  15. Colombia: reasons to create a national space agency

    NASA Astrophysics Data System (ADS)

    Arenales-Vergara, Oscar A.

    2004-01-01

    All modern nations are concerned with their independence, whether political, economic, or intellectual. That is why we support countries which are in the process of development becoming actively involved in the international space scene. Indeed, having limitations in industrial and technological exchange, we feel excluded today from key fields which hold promise for our future. The present moment is one of serious crises in Colombia's history. This paper thus proposes to demonstrate how the nation could, in an atmosphere free from fratricidal conflicts, exploit its space capabilities. We do not limit our focus to the scientific field, but also consider the social, economic and cultural aspects. The results of this research delineate how Colombia could start a new optimistic phase of its development, joining the international space programs within the framework of agreements among the regional governments in Latin America.

  16. 78 FR 18877 - Defense Federal Acquisition Regulation Supplement: New Free Trade Agreement With Colombia (DFARS...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-28

    ... Regulation Supplement (DFARS) to implement the United States-Colombia Trade Promotion Agreement. This Trade Promotion Agreement is a free trade agreement that provides for mutually non-discriminatory treatment of... States-Colombia Trade Promotion Agreement Implementation Act (Pub. L. 112-42) (19 U.S.C. 3805 note). No...

  17. [Association between inequality and suicide rate in Colombia (1994-2013)].

    PubMed

    Campo-Arias, Adalberto; Herazo, Edwin

    2015-01-01

    Income inequality is directly related to the mental health of the population. However, the relationship between income inequality and suicide rates in Colombia has still not been explored. To estimate the relationship between inequality and suicide rates in Colombia from 1994 to 2013. An ecological study was conducted, in which the correlation was estimated (Spearman) between inequality (Gini coefficient) and suicide rate between 1994 and 2013, according to official information available from the National Administrative Department of Statistics (DANE), and the National Institute of Forensic Science and Forensic Medicine. A Gini coefficient between 0.53 and 0.60 (median, 0.65 [interquartile range, 0.54-0.57]) was observed, and suicide rates were between 3.84 and 5.26 (median, 4.20 [4.08-4.86]). The correlation between inequality and suicide rates was positive and statistically significant (r=.70; p<.001). There is a positive association between economic inequality and suicide rate in Colombia. It is important to achieve greater equity in the distribution of income to reduce suicide rate in the country. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  18. CONTRIBUTIONS TO RICKETTSIOSES RESEARCH IN COLOMBIA (1917-1943), LUIS B. PATIÑO CAMARGO

    PubMed Central

    FACCINI-MARTÍNEZ, Álvaro A.; BOTERO-GARCÍA, Carlos A.; HIDALGO, Marylin

    2016-01-01

    Colombian physician Luis Benigno Patiño Camargo was one of the pioneers in the study of rickettsioses in South America, demonstrating for the first time in Colombia the presence of Rickettsia rickettsii as the etiological agent of a highly deadly exanthematic febrile syndrome in the 1930s. However, Patiño-Camargo performed other investigations from 1917-1943, which represent the first descriptions and scientific evidence of the presence of R. prowazekii and R. typhi in Colombia. Almost 60 years after the latest research conducted by Dr. Patiño-Camargo, rickettsioses were again a matter of interest and research. In the last decade over 20 research studies have been published, showing new endemic areas for R. rickettsii, as well as the description of new rickettsial species in Colombia. PMID:27074327

  19. CONTRIBUTIONS TO RICKETTSIOSES RESEARCH IN COLOMBIA (1917-1943), LUIS B. PATIÑO CAMARGO.

    PubMed

    Faccini-Martínez, Álvaro A; Botero-García, Carlos A; Hidalgo, Marylin

    2016-01-01

    Colombian physician Luis Benigno Patiño Camargo was one of the pioneers in the study of rickettsioses in South America, demonstrating for the first time in Colombia the presence of Rickettsia rickettsii as the etiological agent of a highly deadly exanthematic febrile syndrome in the 1930s. However, Patiño-Camargo performed other investigations from 1917-1943, which represent the first descriptions and scientific evidence of the presence of R. prowazekii and R. typhi in Colombia. Almost 60 years after the latest research conducted by Dr. Patiño-Camargo, rickettsioses were again a matter of interest and research. In the last decade over 20 research studies have been published, showing new endemic areas for R. rickettsii, as well as the description of new rickettsial species in Colombia.

  20. Contributions to the knowledge of hard ticks (Acari: Ixodidae) in Colombia.

    PubMed

    Rivera-Páez, Fredy A; Labruna, Marcelo B; Martins, Thiago F; Perez, Jorge E; Castaño-Villa, Gabriel J; Ossa-López, Paula A; Gil, Carlos A; Sampieri, Bruno Rodrigues; Aricapa-Giraldo, Hector J; Camargo-Mathias, Maria I

    2018-01-01

    The known tick fauna of Colombia includes 58 species (15 Argasidae and 43 Ixodidae). To add to the knowledge of the biology of ticks in Colombia, hard ticks (Ixodidae) were collected from domestic animals or vegetation during 2014-2016 in 10 of Colombia's Departments. Ticks were identified to species through morphological examinations. Taxonomic identification was confirmed for some specimens by molecular methods, including phylogenetic analyses inferred from three tick genes (cytochrome c oxidase, 16S rDNA, second internal transcribed spacer). A total of 1745 tick specimens encompassing 8 species were collected. Overall, 5 tick species were recorded on cattle [Amblyomma dissimile, Amblyomma mixtum, Dermacentor nitens, Rhipicephalus microplus, Rhipicephalus sanguineus sensu lato (s.l.)], 5 on dogs (Amblyomma maculatum, Amblyomma ovale, Amblyomma varium, R. microplus, R. sanguineus s.l.), 3 on horses (A. mixtum, D. nitens, R. sanguineus s.l.), 3 on donkeys (A. mixtum, D. nitens, R. microplus), 1 on pig (D. nitens), and 2 from vegetation (A. mixtum, A. dissimile). This included the first records of A. mixtum from two Colombian Departments, indicating that the distribution of this tick in Colombia may be broader than currently known. Phylogenetic analyses confirmed that R. sanguineus s.l. specimens from 8 Departments belong to the "tropical species". Moreover, Colombian specimens of A. maculatum formed a large clade with GenBank sequences of A. maculatum and A. triste, although some Colombian specimens grouped with A. maculatum from the United States while others grouped with A. triste from Brazil. Significant polymorphisms were observed between specimens of A. ovale or D. nitens; for the former species, it is noteworthy that two distinct clades were observed. Our study provides new records for 8 tick species parasitizing domestic animals in Colombia, including species with veterinary and medical importance in the Neotropical region, such as R. microplus, R

  1. From valley to marginal glaciation in alpine-type relief: Lateglacial glacier advances in the Pięć Stawów Polskich/Roztoka Valley, High Tatra Mountains, Poland

    NASA Astrophysics Data System (ADS)

    Zasadni, Jerzy; Kłapyta, Piotr

    2016-01-01

    The Pięć Stawów Polskich-Roztoka Valley in the High Tatras (Western Carpathians) features typical alpine-type relief with a deeply incised glacial trough and large, compound trough head cirque. The prominent hypsographic maximum in the valley (1680-2000 m) along with a broad cirque bottom had provided a vast space for recording glacial and periglacial landforms, specifically the most recent Lateglacial advances. The valley has been intensively studied before in the context of glacial chronology. In this paper, we re-establish the post-Last Glacial Maximum (LGM) glacial chronology of the valley via detailed geomorphologic mapping, equilibrium line altitude (ELA) reconstruction, and Schmidt hammer (SH) dating, along with a critical review of previously published cosmogenic exposure age data (36Cl) and lacustrine sediment chronology. Our results indicate that the first four of the five distinguished Lateglacial stages (Roztoka I-III, Pusta I) occurred before the Bølling/Allerød (B/A) interstadial; thus, virtually the entire valley became deglaciated in course of the Oldest Dryas cold phase. A distinct reorganization of deglacial patterns from valley-type to marginal-type occurred before B/A warming when the ELA increased above the valley hypsographic maximum concentrated at the cirque bottom elevation. It shows that noticeable deglaciation step can be caused due to topographic reason with a minimal climate forcing. This points also to an important role of glaciated valley hypsography in regulating the distribution of moraines which is rarely taken into account in paleoglaciological reconstructions. We infer that glaciers vanished in the Tatra Mountains during the B/A interstadial. Later, a renewed advance during the Younger Dryas (Pusta II) formed a nearly continuous, festoon shaped pattern of moraines and rock glaciers in close distance to cirque backwalls. Furthermore, we discus some paleoenvironmental significance of the geomorphological record in the valley

  2. First record and a new species of Cylindroxystus Bierig (Coleoptera, Staphylinidae, Paederinae) in Colombia.

    PubMed

    Ramírez, José; Asenjo, Angélico

    2017-11-01

    Cylindroxystus janualis sp. nov., of the Paederinae, subtribe Cylindroxystina, from Chocó, northwest Colombia is described, illustrated and distinguished from the other species mainly using aedeagal characters. This is the first record of Cylindroxystus Bierig 1943 from Colombia.

  3. Climatic and morphological controls on post-glacial lake and river valley evolution in the Weichselian belt - an example from the Wda valley, Northern Poland

    NASA Astrophysics Data System (ADS)

    Kramkowski, M. A.; Błaszkiewicz, M.; Piotrowski, J. A.; Brauer, A.; Gierszewski, P.; Kordowski, J.; Lamparski, P.; Lorenz, S.; Noryśkiewicz, A. M.; Ott, F.; Slowinski, M. M.; Tyszkowski, S.

    2014-12-01

    The River Wda valley is a classical example of a polygenetic valley, consisting of former lake basins joined by erosive gap sections. In its middle section, which was the subject of our research, a fragment of an abandoned Lateglacial river valley is preserved, which is unique for the Weichselian moraine belt in the Central European Lowlands. The analysis of the relationship between the lacustrine and fluvial sediments and landforms enabled the authors to report many evolutionary connections between the initial period of the river system formation and the emergence of lakes during the Weichselian Lateglacial. The surface drainage essentially determined the progress of melting of dead ice blocks buried in the glacial depressions, which finally led to lake formation there. Most of the lake basins in the study area were formed during the Bølling-Allerød period. However, one section of the subglacial channel was not exposed to the thermokarst conditions and was therefore preserved with dead ice blocks throughout the entire Lateglacial. The dead ice decay at the beginning of the Holocene, as well as the emergence of another lake, created a lower base level of erosion in the close vicinity of the abandoned valley and induced a change of the river's course. Both fluvial and lacustrine deposits and landforms distributed in the central section of the River Wda valley indicate two processes, which proceeded simultaneously: (1) emergence of fluvially joined lake basins within a glacial channel, (2) degradation of the river bed in the gap sections interfering between the lakes. The processes described for the central section of the River Wda channel indicate a very dynamic river valley development during the Weichselian Lateglacial and the early Holocene. The valley formation was tightly interwoven with the morphogenesis of the primary basins within the valley, mainly with the melting of the buried blocks of dead ice and the development of lakes. This study is a contribution

  4. 11. VIEW OF YAKIMA VALLEY TRANSPORTATION COMPANY AND UNION PACIFIC ...

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

    11. VIEW OF YAKIMA VALLEY TRANSPORTATION COMPANY AND UNION PACIFIC RAILROAD INTERCHANGE TRACKS AT YAKIMA, SHOWING DETAIL OF OVERHEAD WIRING - Yakima Valley Transportation Company Interurban Railroad, Connecting towns of Yakima, Selah & Wiley City, Yakima, Yakima County, WA

  5. Energy Band Gap Dependence of Valley Polarization of the Hexagonal Lattice

    NASA Astrophysics Data System (ADS)

    Ghalamkari, Kazu; Tatsumi, Yuki; Saito, Riichiro

    2018-02-01

    The origin of valley polarization of the hexagonal lattice is analytically discussed by tight binding method as a function of energy band gap. When the energy gap decreases to zero, the intensity of optical absorption becomes sharp as a function of k near the K (or K') point in the hexagonal Brillouin zone, while the peak intensity at the K (or K') point keeps constant with decreasing the energy gap. When the dipole vector as a function of k can have both real and imaginary parts that are perpendicular to each other in the k space, the valley polarization occurs. When the dipole vector has only real values by selecting a proper phase of wave functions, the valley polarization does not occur. The degree of the valley polarization may show a discrete change that can be relaxed to a continuous change of the degree of valley polarization when we consider the life time of photo-excited carrier.

  6. Disarmament, Demobilization, and Reintegration of FARC: A Challenge for Colombia and a Step Toward Andean Region Stability

    DTIC Science & Technology

    2014-12-01

    Chernick, “ Las Dimensiones Internacionales De Los Conflictos Internos En América Latina: De La Guerra Fría (a La Paz Negociada En Centroamérica) a...www.un.org/ en / peacekeeping/missions/past/onusal.htm. 54 Daniel Flores, “El Salvador: Problematica Relacionada con las Tierras Excedantarias en el...Borda, and Eduardo Umana Luna, La Violencia en Colombia, [The Violence in Colombia] 2nd ed., vol. I (Bogota, Colombia: Taurus, 2005), 118. 125 Ibid

  7. Asymmetric valley-resolved beam splitting and incident modes in slanted graphene junctions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hsieh, S. H.; Chu, C. S.

    2016-01-18

    Electron injection into a graphene sheet through a slanted armchair graphene nanoribbon (AGNR) is investigated. An incident mode, or subband, in the AGNR is valley-unpolarized. Our attention is on the valley-resolved nature of the injected electron beams and its connection to the incident mode. It is known for a normal injection that an incident mode will split symmetrically into two valley-resolved beams of equal intensity. We show, in contrast, that slanted injections result in asymmetric valley-resolved beam splitting. The most asymmetric beam splitting cases, when one of the valley-resolved beams has basically disappeared, are found and the condition derived. Thismore » is shown not due to trigonal warping because it holds even in the low incident energy regime, as long as collimation allows. These most asymmetric beam splitting cases occur at energies within an energy interval near and include the subband edge of an incident mode. The physical picture is best illustrated by a projection of the slanted AGNR subband states onto that of the 2D graphene sheet. It follows that the disappearing of a valley-resolved beam coincides with the situation that the group velocities of the projected states in the corresponding valley are in backward directions.« less

  8. [Public health policies as regards the elderly in Colombia].

    PubMed

    Cardona Arango, Doris; Segura Cardona, Angela María

    2011-01-01

    A literature review was performed on the laws passed, and adopted in accordance with international regulations, in Colombia and which currently benefit or affect the quality of life of the elderly. Public policies in Colombia are inclined towards the well-being of the elderly, but this documental analysis concludes that the elderly Colombian is unprotected and defenseless against the obstacles and difficult situations due to the biological, political, social, economic and environmental conditions. This makes them vulnerable as it is a scheme that only benefits in cases of poverty and by being a member of the General Social Security in Health system, with transfer of obligations to the family, society and likewise the elderly. Copyright © 2010 SEGG. Published by Elsevier Espana. All rights reserved.

  9. Ground water in Tooele Valley, Utah

    USGS Publications Warehouse

    Gates, J.S.; Keller, O.A.

    1970-01-01

    This short report was written by condensing parts of a technical report on the ground water in Tooele Valley, which was prepared as part of a cooperative program between the Utah Department of Natural Resources, Division of Water Rights, and the U. S. Geological Survey to study water in Utah. If you would like to read the more detailed technical report, write for a copy of the Utah State Engineer Technical Publication 12, “Reevaluation of the ground-water resources of Tooele Valley, Utah” by J. S. Gates. Copies can be obtained free of charge from the Division of Water Rights, State Capitol, Salt Lake City, Utah 84114.

  10. VEGETATION CHARACTERIZATION OF THREE CONTRASTING RIPARIAN SITES, WILLAMETTE VALLEY, OR

    EPA Science Inventory

    Much of the native riparian vegetation of the Willamette Valley, Oregon, has been replaced with agricultural crops or invasive non-native plant species. Detailed information about current Willamette Valley riparian vegetation is generally lacking. Plant species composition data...

  11. Imaging of pure spin-valley diffusion current in WS2-WSe2 heterostructures.

    PubMed

    Jin, Chenhao; Kim, Jonghwan; Utama, M Iqbal Bakti; Regan, Emma C; Kleemann, Hans; Cai, Hui; Shen, Yuxia; Shinner, Matthew James; Sengupta, Arjun; Watanabe, Kenji; Taniguchi, Takashi; Tongay, Sefaattin; Zettl, Alex; Wang, Feng

    2018-05-25

    Transition metal dichalcogenide (TMDC) materials are promising for spintronic and valleytronic applications because valley-polarized excitations can be generated and manipulated with circularly polarized photons and the valley and spin degrees of freedom are locked by strong spin-orbital interactions. In this study we demonstrate efficient generation of a pure and locked spin-valley diffusion current in tungsten disulfide (WS 2 )-tungsten diselenide (WSe 2 ) heterostructures without any driving electric field. We imaged the propagation of valley current in real time and space by pump-probe spectroscopy. The valley current in the heterostructures can live for more than 20 microseconds and propagate over 20 micrometers; both the lifetime and the diffusion length can be controlled through electrostatic gating. The high-efficiency and electric-field-free generation of a locked spin-valley current in TMDC heterostructures holds promise for applications in spin and valley devices. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  12. Astroparticle physics at the Eastern Colombia region

    NASA Astrophysics Data System (ADS)

    Asorey, Hernán; Núñez, Luis A.

    2015-12-01

    We present the emerging panorama of Astroparticle Physics at the Eastern Colombia region, and describe several ongoing projects, most of them related to the Latin American Giant Observatory (LAGO) Project. This research work is carried out at the Grupo de Investigaciones en Relatividad y Gravitacin of Universidad Industrial de Santander.

  13. Taxonomic and Functional Diversity of Soil and Hypolithic Microbial Communities in Miers Valley, McMurdo Dry Valleys, Antarctica.

    PubMed

    Wei, Sean T S; Lacap-Bugler, Donnabella C; Lau, Maggie C Y; Caruso, Tancredi; Rao, Subramanya; de Los Rios, Asunción; Archer, Stephen K; Chiu, Jill M Y; Higgins, Colleen; Van Nostrand, Joy D; Zhou, Jizhong; Hopkins, David W; Pointing, Stephen B

    2016-01-01

    The McMurdo Dry Valleys of Antarctica are an extreme polar desert. Mineral soils support subsurface microbial communities and translucent rocks support development of hypolithic communities on ventral surfaces in soil contact. Despite significant research attention, relatively little is known about taxonomic and functional diversity or their inter-relationships. Here we report a combined diversity and functional interrogation for soil and hypoliths of the Miers Valley in the McMurdo Dry Valleys of Antarctica. The study employed 16S rRNA fingerprinting and high throughput sequencing combined with the GeoChip functional microarray. The soil community was revealed as a highly diverse reservoir of bacterial diversity dominated by actinobacteria. Hypolithic communities were less diverse and dominated by cyanobacteria. Major differences in putative functionality were that soil communities displayed greater diversity in stress tolerance and recalcitrant substrate utilization pathways, whilst hypolithic communities supported greater diversity of nutrient limitation adaptation pathways. A relatively high level of functional redundancy in both soil and hypoliths may indicate adaptation of these communities to fluctuating environmental conditions.

  14. Diversity of inland valleys and opportunities for agricultural development in Sierra Leone.

    PubMed

    Dossou-Yovo, Elliott Ronald; Baggie, Idriss; Djagba, Justin Fagnombo; Zwart, Sander Jaap

    2017-01-01

    Inland valleys are becoming increasingly important agricultural production areas for rural households in sub-Saharan Africa due to their relative high and secure water availability and soil fertility. In addition, inland valleys are important as water buffer and biodiversity hot spots and they provide local communities with forest, forage, and fishing resources. As different inland-valley ecosystem functions may conflict with agricultural objectives, indiscriminate development should be avoided. This study aims to analyze the diversity of inland valleys in Sierra Leone and to develop guidelines for more precise interventions. Land use, biophysical and socio-economic data were analyzed on 257 inland valleys using spatial and multivariate techniques. Five cluster groups of inland valleys were identified: (i) semi-permanently flooded with high soil organic carbon (4.2%) and moderate available phosphorus (10.2 ppm), mostly under natural vegetation; (ii) semi-permanently flooded with low soil organic carbon (1.5%) and very low available phosphorus (3.1 ppm), abandoned by farmers; (iii) seasonally flooded with moderate soil organic carbon (3.1%) and low available phosphorus (8.3 ppm), used for rainfed rice and off-season vegetables produced without fertilizer application for household consumption and market; (iv) well drained with moderate soil organic carbon (3.8%) and moderate available phosphorus (10.0 ppm), used for rainfed rice and off-season vegetables produced with fertilizer application for household consumption and market; and (v) well drained with moderate soil organic carbon (3.6%) and moderate available phosphorus (11 ppm), used for household consumption without fertilizer application. Soil organic carbon, available phosphorus, hydrological regime, physical accessibility and market opportunity were the major factors affecting agricultural intensification of inland valleys. Opening up the areas in which inland valleys occur through improved roads and markets

  15. 12. VIEW OF YAKIMA VALLEY TRANSPORTATION COMPANY AND UNION PACIFIC ...

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

    12. VIEW OF YAKIMA VALLEY TRANSPORTATION COMPANY AND UNION PACIFIC RAILROAD INTERCHANGE TRACKS AT YAKIMA, SHOWING SOUTH END OF OVERHEAD WIRING TERMINATION - Yakima Valley Transportation Company Interurban Railroad, Connecting towns of Yakima, Selah & Wiley City, Yakima, Yakima County, WA

  16. EPA awards $352,000 brownfields grants to Elk Valley Rancheria

    EPA Pesticide Factsheets

    SAN FRANCISCO - The U.S. Environmental Protection Agency announced today that the Elk Valley Rancheria will receive $352,000 in federal grants to clean up two contaminated properties near Crescent City, Calif. Elk Valley Rancheria is among 147 commu

  17. Screening effects due to carrier doping on valley relaxation in transition metal dichalcogenide monolayers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Konabe, Satoru

    2016-08-15

    This work theoretically investigated the mechanism of valley polarization relaxation in monolayers of transition metal dichalcogenides, focusing on the exchange interactions between electrons and holes. In particular, we elucidated the effects of screening resulting from carrier doping on valley depolarization dynamics. The results show that the valley relaxation time is highly dependent on the extent of carrier doping. In addition, a finite degree of doping is predicted to induce additional valley relaxation temperature dependence at low temperatures, an effect that is absent at zero doping. Our calculation results suggest the possibility of increasing the valley relaxation time by tuning carriermore » doping, which could present a means of manipulating the valley degrees of freedom.« less

  18. The Imperial Valley of California is critical to wintering Mountain Plovers

    USGS Publications Warehouse

    Wunder, Michael B.; Knopf, F.L.

    2003-01-01

    We surveyed Mountain Plovers (Charadrius montanus) wintering in the Imperial Valley of California in January 2001, and also recorded the types of crop fields used by plovers in this agricultural landscape. We tallied 4037 plovers in 36 flocks ranging in size from 4 to 596 birds. Plovers were more common on alfalfa and Bermudagrass fields than other field types. Further, most birds were on alfalfa fields that were currently being (or had recently been) grazed, primarily by domestic sheep. Plovers used Bermudagrass fields only after harvest and subsequent burning. Examination of Christmas Bird Count data from 1950–2000 indicated that the Mountain Plover has abandoned its historical wintering areas on the coastal plains of California. Numbers in the Central Valley seem to have undergone recent declines also. We believe that the cultivated landscape of the Imperial Valley provides wintering habitats for about half of the global population of Mountain Plovers. We attribute the current importance of the Imperial Valley for Mountain Plovers to loss of native coastal and Central Valley habitats rather than to a behavioral switching of wintering areas through time. Future changes in specific cropping or management practices in the Imperial Valley will have a major impact on the conservation status of this species.

  19. Ground-water hydrology of the upper Sevier River Basin, south-central Utah, and simulation of ground-water flow in the valley-fill in Panguitch Valley.

    USGS Publications Warehouse

    Thiros, Susan A.; Brothers, William C.

    1993-01-01

    The ground-water hydrology of the upper Sevier River basin, primarily of the unconsolidated valley-fill aquifers, was studied from 1988 to 1989. Recharge to the valley-fill aquifers is mostly by seepage from surface-water sources. Changes in soil-moisture content am water levels were measured in Panguitch Valley both at a flood-irrigated and at a sprinkler-irrigated alfalfa field to quantify seepage from unconsumed irrigation water. Lag time between irrigation and water-level response decreased from 6 to 2 days in the flood-irrigated field as the soil-moisture content increased. Water levels measured in the sprinkler-irrigated field did not respond to irrigation. Discharge from the valley-fill aquifer to the Sevier River in Panguitch Valley is about 53,570 acre-feet per year.Water levels measured in wells from 1951 to 1989 tend to fluctuate with the quantity of precipitation falling at higher elevations. Ground-water discharge to the Sevier River in Panguitch Valley causes a general increase in the specific conductance of the river in a downstream direction.A three-layered ground-water-flow model was used to simulate the effects of changes in irrigation practices am increased ground-water withdrawals in Panguitch Valley. The establishment of initial conditions consisted of comparing simulated water levels and simulated gains and losses from the Sevier River and selected canals with values measured during the 1988 irrigation season. The model was calibrated by comparing water-level changes measured from 1961 to 1963 to simulated changes. A simulated change from flood to sprinkler irrigation resulted in a maximum decline in water level of 0.9 feet after the first year of change. Simulating additional discharge from wells resulted in drawdowns of about 20 feet after the first year of pumping.

  20. Forecasting of Average Monthly River Flows in Colombia

    NASA Astrophysics Data System (ADS)

    Mesa, O. J.; Poveda, G.

    2006-05-01

    The last two decades have witnessed a marked increase in our knowledge of the causes of interannual hydroclimatic variability and our ability to make predictions. Colombia, located near the seat of the ENSO phenomenon, has been shown to experience negative (positive) anomalies in precipitation in concert with El Niño (La Niña). In general besides the Pacific Ocean, Colombia has climatic influences from the Atlantic Ocean and the Caribbean Sea through the tropical forest of the Amazon basin and the savannas of the Orinoco River, in top of the orographic and hydro-climatic effects introduced by the Andes. As in various other countries of the region, hydro-electric power contributes a large proportion (75 %) of the total electricity generation in Colombia. Also, most agriculture is rain-fed dependant, and domestic water supply relies mainly on surface waters from creeks and rivers. Besides, various vector borne tropical diseases intensify in response to rain and temperature changes. Therefore, there is a direct connection between climatic fluctuations and national and regional economies. This talk specifically presents different forecasts of average monthly stream flows for the inflow into the largest reservoir used for hydropower generation in Colombia, and illustrates the potential economic savings of such forecasts. Because of planning of the reservoir operation, the most appropriated time scale for this application is the annual to interannual. Fortunately, this corresponds to the scale at which hydroclimate variability understanding has improved significantly. Among the different possibilities we have explored: traditional statistical ARIMA models, multiple linear regression, natural and constructed analogue models, the linear inverse model, neural network models, the non-parametric regression splines (MARS) model, regime dependant Markovian models and one we termed PREBEO, which is based on spectral bands decomposition using wavelets. Most of the methods make

  1. The Proposed U.S.-Colombia Free Trade Agreement: Economic and Political Implications

    DTIC Science & Technology

    2010-04-16

    2008. 50 Ibid, p. 2. 51 Colombia’s Observatorio del Programa Presidencial de DDHH y DIH, Vicepresidencia de la República, April 2008. 52 See CRS...President Alvaro Uribe, “Se Hara Todo el Esfuerzo Para Que No Se Le Niegue el TLC a Colombia, Anuncia el Presidente de Colombia en Entrevista a Caracol...focus of U.S. trade policy as demonstrated by the passage of the North American Free Trade Agreement (NAFTA), the U.S.- Chile Free Trade Agreement, the

  2. Hydrology of Northern Utah Valley, Utah County, Utah, 1975-2005

    USGS Publications Warehouse

    Cederberg, Jay R.; Gardner, Philip M.; Thiros, Susan A.

    2009-01-01

    The ground-water resources of northern Utah Valley, Utah, were assessed during 2003-05 to describe and quantify components of the hydrologic system, determine a hydrologic budget for the basin-fill aquifer, and evaluate changes to the system relative to previous studies. Northern Utah Valley is a horst and graben structure with ground water occurring in both the mountain-block uplands surrounding the valley and in the unconsolidated basin-fill sediments. The principal aquifer in northern Utah Valley occurs in the unconsolidated basin-fill deposits where a deeper unconfined aquifer occurs near the mountain front and laterally grades into multiple confined aquifers near the center of the valley. Sources of water to the basin-fill aquifers occur predominantly as either infiltration of streamflow at or near the interface of the mountain front and valley or as subsurface inflow from the adjacent mountain blocks. Sources of water to the basin-fill aquifers were estimated to average 153,000 (+/- 31,500) acre-feet annually during 1975-2004 with subsurface inflow and infiltration of streamflow being the predominant sources. Discharge from the basin-fill aquifers occurs in the valley lowlands as flow to waterways, drains, ditches, springs, as diffuse seepage, and as discharge from flowing and pumping wells. Ground-water discharge from the basin-fill aquifers during 1975-2004 was estimated to average 166,700 (+/- 25,900) acre-feet/year where discharge to wells for consumptive use and discharge to waterways, drains, ditches, and springs were the principal sources. Measured water levels in wells in northern Utah Valley declined an average of 22 feet from 1981 to 2004. Water-level declines are consistent with a severe regional drought beginning in 1999 and continuing through 2004. Water samples were collected from 36 wells and springs throughout the study area along expected flowpaths. Water samples collected from 34 wells were analyzed for dissolved major ions, nutrients, and

  3. 77 FR 30359 - Defense Federal Acquisition Regulation Supplement: New Free Trade Agreement With Colombia (DFARS...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-22

    ... (see FAR 25.408). II. Discussion and Analysis This interim rule adds Colombia to the definition of...,000 for construction. Because the Colombia FTA construction threshold of $7,777,000 is the same as the... states that acquisitions that do not exceed $150,000 (with some exceptions) are automatically reserved...

  4. Geomorphic response to tectonically-induced ground deformation in the Wabash Valley

    USGS Publications Warehouse

    Fraser, G.S.; Thompson, T.A.; Olyphant, G.A.; Furer, L.; Bennett, S.W.

    1997-01-01

    Numerous low- to moderate-intensity earthquakes have been recorded in a zone of diffuse modern seismicity in southwest Indiana, southeast Illinois, and northernmost Kentucky. Structural elements within the zone include the Wabash Valley Fault System, the LaSalle Anticlinal Belt in western Illinois, and the Rough Creek-Shawneetown Fault System in northern Kentucky. The presence of seismically-induced liquefaction features in the near-surface alluvial sediments in the region indicates that strong ground motion has occurred in the recent geological past, but because the glacial and alluvial sediments in the Wabash Valley appear to be otherwise undisturbed, post-Paleozoic ground deformation resulting from movement on these structural elements has not yet been documented. Morphometric analysis of the land surface, detailed mapping of geomorphic elements in the valley, reconnaissance drilling of the Holocene and Pleistocene alluvium, and structural analysis of the bedrock underlying the valley were used to determine whether the geomorphology of the valley and the patterns of alluviation of the Wabash River were affected by surface deformation associated with the seismic zone during the late Pleistocene and Holocene. Among the observed features in the valley that can be attributed to deformation are: (1) tilting of the modern land surface to the west, (2) preferred channel migration toward the west side of the valley, with concomitant impact on patterns of soil development and sedimentation rate, (3) a convex longitudinal profile of the Wabash River where it crosses the LaSalle Anticlinal Belt, and (4) increased incision of the river into its floodplain downstream from the anticlinal belt.

  5. Valley plugs, land use, and phytogeomorphic response: Chapter 14

    USGS Publications Warehouse

    Pierce, Aaron R.; King, Sammy L.; Shroder, John F.

    2013-01-01

    Anthropogenic alteration of fluvial systems can disrupt functional processes that provide valuable ecosystem services. Channelization alters fluvial parameters and the connectivity of river channels to their floodplains which is critical for productivity, nutrient cycling, flood control, and biodiversity. The effects of channelization can be exacerbated by local geology and land-use activities, resulting in dramatic geomorphic readjustments including the formation of valley plugs. Considerable variation in the response of abiotic processes, including surface hydrology, subsurface hydrology, and sedimentation dynamics, to channelization and the formation of valley plugs. Altered abiotic processes associated with these geomorphic features and readjustments influence biotic processes including species composition, abundance, and successional processes. Considerable interest exists for restoring altered fluvial systems and their floodplains because of their social and ecological importance. Understanding abiotic and biotic responses of channelization and valley-plug formation within the context of the watershed is essential to successful restoration. This chapter focuses on the primary causes of valley-plug formation, resulting fluvial-geomorphic responses, vegetation responses, and restoration and research needs for these systems.

  6. Gravity Data from Newark Valley, White Pine County, Nevada

    USGS Publications Warehouse

    Mankinen, Edward A.; McKee, Edwin H.

    2007-01-01

    The Newark Valley area, eastern Nevada is one of thirteen major ground-water basins investigated by the BARCAS (Basin and Range Carbonate Aquifer Study) Project. Gravity data are being used to help characterize the geophysical framework of the region. Although gravity coverage was extensive over parts of the BARCAS study area, data were sparse for a number of the valleys, including the northern part of Newark Valley. We addressed this lack of data by establishing seventy new gravity stations in and around Newark Valley. All available gravity data were then evaluated to determine their reliability, prior to calculating an isostatic residual gravity map to be used for subsequent analyses. A gravity inversion method was used to calculate depths to pre-Cenozoic basement rock and estimates of maximum alluvial/volcanic fill. The enhanced gravity coverage and the incorporation of lithologic information from several deep oil and gas wells yields a view of subsurface shape of the basin and will provide information useful for the development of hydrogeologic models for the region.

  7. 78 FR 34127 - Notice of Inventory Completion: Coachella Valley History Museum, Indio, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-06

    ... Valley History Museum professional staff in consultation with representatives of Torres Martinez Desert....R50000] Notice of Inventory Completion: Coachella Valley History Museum, Indio, CA AGENCY: National Park Service, Interior. ACTION: Notice. SUMMARY: The Coachella Valley History Museum has completed an inventory...

  8. Bedrock mapping of buried valley networks using seismic reflection and airborne electromagnetic data

    NASA Astrophysics Data System (ADS)

    Oldenborger, G. A.; Logan, C. E.; Hinton, M. J.; Pugin, A. J.-M.; Sapia, V.; Sharpe, D. R.; Russell, H. A. J.

    2016-05-01

    In glaciated terrain, buried valleys often host aquifers that are significant groundwater resources. However, given the range of scales, spatial complexity and depth of burial, buried valleys often remain undetected or insufficiently mapped. Accurate and thorough mapping of bedrock topography is a crucial step in detecting and delineating buried valleys and understanding formative valley processes. We develop a bedrock mapping procedure supported by the combination of seismic reflection data and helicopter time-domain electromagnetic data with water well records for the Spiritwood buried valley aquifer system in Manitoba, Canada. The limited spatial density of water well bedrock observations precludes complete depiction of the buried valley bedrock topography and renders the water well records alone inadequate for accurate hydrogeological model building. Instead, we leverage the complementary strengths of seismic reflection and airborne electromagnetic data for accurate local detection of the sediment-bedrock interface and for spatially extensive coverage, respectively. Seismic reflection data are used to define buried valley morphology in cross-section beneath survey lines distributed over a regional area. A 3D model of electrical conductivity is derived from inversion of the airborne electromagnetic data and used to extrapolate buried valley morphology over the entire survey area. A spatially variable assignment of the electrical conductivity at the bedrock surface is applied to different features of the buried valley morphology identified in the seismic cross-sections. Electrical conductivity is then used to guide construction of buried valley shapes between seismic sections. The 3D locus of points defining each morphological valley feature is constructed using a path optimization routine that utilizes deviation from the assigned electrical conductivities as the cost function. Our resulting map represents a bedrock surface of unprecedented detail with more

  9. Rock-fall potential in the Yosemite Valley, California

    USGS Publications Warehouse

    Wieczorek, G.F.; Morrissey, M.M.; Iovine, Giulio; Godt, Jonathan

    1999-01-01

    We used two methods of estimating rock-fall potential in the Yosemite Valley, California based on (1) physical evidence of previous rock-fall travel, in which the potential extends to the base of the talus, and (2) theoretical potential energy considerations, in which the potential can extend beyond the base of the talus, herein referred to as the rock-fall shadow. Rock falls in the valley commonly range in size from individual boulders of less than 1 m3 to moderate-sized falls with volumes of about 100,000 m3. Larger rock falls exceeding 100,000 m3, referred to as rock avalanches, are considered to be much less likely to occur based on the relatively few prehistoric rock-fall avalanche deposits in the Yosemite Valley. Because the valley has steep walls and is relatively narrow, there are no areas that are absolutely safe from large rock avalanches. The map shows areas of rock-fall potential, but does not predict when or how frequently a rock fall will occur. Consequently, neither the hazard in terms of probability of a rock fall at any specific location, nor the risk to people or facilities to such events can be assessed from this map.

  10. Valley splitting of single-electron Si MOS quantum dots

    DOE PAGES

    Gamble, John King; Harvey-Collard, Patrick; Jacobson, N. Tobias; ...

    2016-12-19

    Here, silicon-based metal-oxide-semiconductor quantum dots are prominent candidates for high-fidelity, manufacturable qubits. Due to silicon's band structure, additional low-energy states persist in these devices, presenting both challenges and opportunities. Although the physics governing these valley states has been the subject of intense study, quantitative agreement between experiment and theory remains elusive. Here, we present data from an experiment probing the valley states of quantum dot devices and develop a theory that is in quantitative agreement with both this and a recently reported experiment. Through sampling millions of realistic cases of interface roughness, our method provides evidence that the valley physicsmore » between the two samples is essentially the same.« less

  11. Checklist of the freshwater fishes of Colombia: a Darwin Core alternative to the updating problem.

    PubMed

    DoNascimiento, Carlos; Herrera-Collazos, Edgar Esteban; Herrera-R, Guido A; Ortega-Lara, Armando; Villa-Navarro, Francisco A; Oviedo, José Saulo Usma; Maldonado-Ocampo, Javier A

    2017-01-01

    The present work is part of a process to create a Catalogue of the Freshwater Fishes of Colombia and consisted in the depuration and updating of the taxonomic and geographic components of the checklist of the freshwater fishes of Colombia. An exhaustive revision of the 1435 species recorded in 2008 was necessary to: 1. Add new species described since 2009 and species originally described from Colombia but inadvertently omitted in 2008; 2. Add new records of already described species; 3. Delete species whose presence in Colombia was not supported by voucher specimens in ichthyological collections; and 4. Revise the geographic distribution of the species listed in 2008. This process resulted in the following numbers: 1. Total number of freshwater fish species in Colombia: 1494; 2. Number of species recorded by hydrographic region - Amazon: 706, Orinoco: 663, Caribbean: 223, Magdalena-Cauca: 220, Pacific: 130; and 3. Number of endemic species: 374 (76% from the trans-Andean region). Updating the current checklist is a fundamental requirement to ensure its incorporation in the decision-making process with regard to the conservation of Colombian aquatic species and ecosystems, which are facing transformation processes as a result of activities such as mining, construction of hydroelectric plants, expansion of the agricultural frontier and subsequent deforestation, industrial and domestic pollution, development of waterways, introduction of exotic species, and climate change.

  12. Checklist of the freshwater fishes of Colombia: a Darwin Core alternative to the updating problem

    PubMed Central

    DoNascimiento, Carlos; Herrera-Collazos, Edgar Esteban; Herrera-R., Guido A.; Ortega-Lara, Armando; Villa-Navarro, Francisco A.; Oviedo, José Saulo Usma; Maldonado-Ocampo, Javier A.

    2017-01-01

    Abstract The present work is part of a process to create a Catalogue of the Freshwater Fishes of Colombia and consisted in the depuration and updating of the taxonomic and geographic components of the checklist of the freshwater fishes of Colombia. An exhaustive revision of the 1435 species recorded in 2008 was necessary to: 1. Add new species described since 2009 and species originally described from Colombia but inadvertently omitted in 2008; 2. Add new records of already described species; 3. Delete species whose presence in Colombia was not supported by voucher specimens in ichthyological collections; and 4. Revise the geographic distribution of the species listed in 2008. This process resulted in the following numbers: 1. Total number of freshwater fish species in Colombia: 1494; 2. Number of species recorded by hydrographic region - Amazon: 706, Orinoco: 663, Caribbean: 223, Magdalena-Cauca: 220, Pacific: 130; and 3. Number of endemic species: 374 (76% from the trans-Andean region). Updating the current checklist is a fundamental requirement to ensure its incorporation in the decision-making process with regard to the conservation of Colombian aquatic species and ecosystems, which are facing transformation processes as a result of activities such as mining, construction of hydroelectric plants, expansion of the agricultural frontier and subsequent deforestation, industrial and domestic pollution, development of waterways, introduction of exotic species, and climate change. PMID:29118633

  13. Road traffic injuries in Colombia.

    PubMed

    Rodríguez, Deysi Yasmin; Fernández, Francisco José; Acero Velásquez, Hugo

    2003-01-01

    Road traffic injuries are a leading public health problem in Colombia. Pedestrians are the most vulnerable road users, especially in the main urban centers of Bogotá, Medellin and Cali. Data analyzed in this report include official statistics from the National Police and the National Institute of Legal Medicine and Forensic Sciences for 1996-2000, and results of a study conducted at the National University of Colombia in 2000. Methods from the Highway Capacity Manual were used for determining physical and technical variables, and a Geographical Information System tool was used for the location and spatial analysis of the road traffic crashes. Pedestrians accounted for close to 32% of injuries and 40% of the deaths from road traffic crashes. The problem of road traffic crashes existed predominately in urban areas. In the main urban centers, pedestrians constituted nearly 68% of road traffic crash victims. The high level of risky road use behaviors demonstrated by pedestrians and drivers, and inadequate infrastructure for safe mobility of pedestrians in some sections of the road network were the main contributing factors. Major improvements were achieved in Bogotá following enhancements to the municipal transport system and other policies introduced since 1995. In conclusion, policies and programs for improving road safety, in particular pedestrian safety, and strengthening urban planning are top priority.

  14. Measurement of Valley Kondo Effect in a Si/SiGe Quantum Dot

    NASA Astrophysics Data System (ADS)

    Yuan, Mingyun; Yang, Zhen; Tang, Chunyang; Rimberg, A. J.; Joynt, R.; Savage, D. E.; Lagally, M. G.; Eriksson, M. A.

    2013-03-01

    The Kondo effect in Si/SiGe QDs can be enriched by the valley degree of freedom in Si. We have observed resonances showing temperature dependence characteristic of the Kondo effect in two consecutive Coulomb diamonds. These resonances exhibit unusual magnetic field dependence that we interpret as arising from Kondo screening of the valley degree of freedom. In one diamond two Kondo peaks due to screening of the valley index exist at zero magnetic field, revealing a zero-field valley splitting of Δ ~ 0.28 meV. In a non-zero magnetic field the peaks broaden and coalesce due to Zeeman splitting. In the other diamond, a single resonance at zero bias persists without Zeeman splitting for non-zero magnetic field, a phenomenon characteristic of valley non-conservation in tunneling. This research is supported by the NSA and ARO.

  15. Mississippi Alluvial Valley

    USGS Publications Warehouse

    Reinecke, K.J.; Kaminski, R.M.; Moorhead, D.J.; Hodges, J.D.; Nasser, J.R.; Smith, L.M.; Pederson, R.L.; Kaminski, R.M.

    1989-01-01

    Available data are summarized according to the following major topics: (1) characteristics of the Mississippi Alluvial Valley (MAV); (2) waterfowl populations associated with the MAV; (3) habitat requirements of migrating and wintering waterfowl in the MAV; (4) current habitat management practices in the MAV, including croplands, moist-soil impoundments, and forested wetlands; (5) status and classification of winter habitat in the MAV; and (6) research and management information needs.

  16. Revisiting the 1872 Owens Valley, California, Earthquake

    USGS Publications Warehouse

    Hough, S.E.; Hutton, K.

    2008-01-01

    The 26 March 1872 Owens Valley earthquake is among the largest historical earthquakes in California. The felt area and maximum fault displacements have long been regarded as comparable to, if not greater than, those of the great San Andreas fault earthquakes of 1857 and 1906, but mapped surface ruptures of the latter two events were 2-3 times longer than that inferred for the 1872 rupture. The preferred magnitude estimate of the Owens Valley earthquake has thus been 7.4, based largely on the geological evidence. Reinterpreting macroseismic accounts of the Owens Valley earthquake, we infer generally lower intensity values than those estimated in earlier studies. Nonetheless, as recognized in the early twentieth century, the effects of this earthquake were still generally more dramatic at regional distances than the macroseismic effects from the 1906 earthquake, with light damage to masonry buildings at (nearest-fault) distances as large as 400 km. Macroseismic observations thus suggest a magnitude greater than that of the 1906 San Francisco earthquake, which appears to be at odds with geological observations. However, while the mapped rupture length of the Owens Valley earthquake is relatively low, the average slip was high. The surface rupture was also complex and extended over multiple fault segments. It was first mapped in detail over a century after the earthquake occurred, and recent evidence suggests it might have been longer than earlier studies indicated. Our preferred magnitude estimate is Mw 7.8-7.9, values that we show are consistent with the geological observations. The results of our study suggest that either the Owens Valley earthquake was larger than the 1906 San Francisco earthquake or that, by virtue of source properties and/or propagation effects, it produced systematically higher ground motions at regional distances. The latter possibility implies that some large earthquakes in California will generate significantly larger ground motions than San

  17. Wind's Marks in "Perseverance Valley" (Enhanced Color)

    NASA Image and Video Library

    2017-12-06

    This patch of rocky Martian ground on the floor of "Perseverance Valley" on the inner slope of the western rim of Endurance Crater slopes steeply downhill from left to right. Some textures seen here, including striations just above and parallel to the edge of a solar panel at far left, may be due to abrasion by wind-driven sand. Researchers interpret them as possible signs of past winds blowing from right to left, up and out of the crater, which currently hosts sand dunes on its central floor. The view spans about 11.5 feet (3.5 meters) from left to right and is presented in enhanced color to make differences in surface materials easier to see. The Panoramic Camera (Pancam) on NASA's Mars Exploration Rover Opportunity took the component images of this scene during the period Oct. 13 through Oct. 20, 2017, corresponding to sols (Martian days) 4878 through 4884 of the rover's work on Mars. Opportunity entered the upper end of Perseverance Valley in July 2017 for several months of investigating how it formed. The valley is a system of shallow troughs extending about the length of two football fields down the crater rim's steep inner slope. Endurance Crater is about 14 miles (22 kilometers) in diameter. Opportunity has been exploring features on its western rim since 2011, after investigating a series of smaller craters beginning with the one it landed in on Jan. 25, 2004, Universal Time (Jan. 24, PST). The origin of Perseverance Valley is unknown, but some observed features suggest that water might have played a role in the past. Opportunity is descending the steep valley, making observations along the way that could help illuminate the origin of this feature. The bedrock target area in this view is called "La Bajada." The image combines exposures taken through three Pancam filters, centered at wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). https://photojournal.jpl.nasa.gov/catalog/PIA22072

  18. A reference architecture for integrated EHR in Colombia.

    PubMed

    de la Cruz, Edgar; Lopez, Diego M; Uribe, Gustavo; Gonzalez, Carolina; Blobel, Bernd

    2011-01-01

    The implementation of national EHR infrastructures has to start by a detailed definition of the overall structure and behavior of the EHR system (system architecture). Architectures have to be open, scalable, flexible, user accepted and user friendly, trustworthy, based on standards including terminologies and ontologies. The GCM provides an architectural framework created with the purpose of analyzing any kind of system, including EHR system´s architectures. The objective of this paper is to propose a reference architecture for the implementation of an integrated EHR in Colombia, based on the current state of system´s architectural models, and EHR standards. The proposed EHR architecture defines a set of services (elements) and their interfaces, to support the exchange of clinical documents, offering an open, scalable, flexible and semantically interoperable infrastructure. The architecture was tested in a pilot tele-consultation project in Colombia, where dental EHR are exchanged.

  19. [Tobacco control: an intersectorial experience in Tunja (Colombia)].

    PubMed

    Panader-Torres, Adriana; Agudelo-Cely, Nancy Aurora; Bolívar-Suárez, Yolima; Cárdenas-Cárdenas, Luz Mery

    2014-01-01

    Tobacco control in Colombia is regulated by Law 1335 of 2009. The implementation and monitoring of the provisions of this law require strengthening of intersectorial work at the local level. This field note presents an intersectorial work experience that was carried out in the municipality of Tunja (Colombia) to improve tobacco control. The Respirarte Group was established. This group consists of an intersectorial team composed of 15 institutions. The Respirarte Group achieved the following political and community actions: signing of an agreement on tobacco control by government actors, expedition of a local decree to comply with Law 1335 in the municipality, provision of information and communication, and social mobilization and monitoring. This experience serves as a national and international reference and its lessons could be used in the approach to other public health problems. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

  20. Syphilis infection among female sex workers in Colombia.

    PubMed

    Mejia, Alfredo; Bautista, Christian T; Leal, Luis; Ayala, Claudia; Prieto, Franklyn; de la Hoz, Fernando; Alzate, Martha L; Acosta, Jacqueline; Sanchez, Jose L

    2009-04-01

    To study the epidemiology of Treponema pallidum (syphilis) among female sex workers (FSW) in Santa Fe de Bogotá, Colombia. A cross-sectional study was conducted. Participants were interviewed using a standardized questionnaire, which collected socio-demographic characteristics and risk behavior information. Blood samples were screened for syphilis using the VDRL test and the MHATP assay. The prevalence of syphilis was 10.3% (53/514). Adjusted risk factors significantly associated with syphilis were: age (linear increase), education (primary or no education), monthly income (or=4 years), number of clients per week (>or=22), main workplace (street), inconsistent (never) condom use in sex work, previous STI history, and use of illegal drugs. Effective health education programs for improving the level of knowledge of STI and the promotion of consistent condom use activities along with other appropriate harm reduction activities are urgently required among FSW in Colombia.

  1. Respiratory hospital admissions associated with PM10 pollution in Utah, Salt Lake, and Cache Valleys

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pope CA, I.I.I.

    This study assessed the association between respiratory hospital admissions and PM10 pollution in Utah, Salt Lake, and Cache valleys during April 1985 through March 1989. Utah and Salt Lake valleys had high levels of PM10 pollution that violated both the annual and 24-h standards issued by the Environmental Protection Agency (EPA). Much lower PM10 levels occurred in the Cache Valley. Utah Valley experienced the intermittent operation of its primary source of PM10 pollution: an integrated steel mill. Bronchitis and asthma admissions for preschool-age children were approximately twice as frequent in Utah Valley when the steel mill was operating versus whenmore » it was not. Similar differences were not observed in Salt Lake or Cache valleys. Even though Cache Valley had higher smoking rates and lower temperatures in winter than did Utah Valley, per capita bronchitis and asthma admissions for all ages were approximately twice as high in Utah Valley. During the period when the steel mill was closed, differences in per capita admissions between Utah and Cache valleys narrowed considerably. Regression analysis also demonstrated a statistical association between respiratory hospital admissions and PM10 pollution. The results suggest that PM10 pollution plays a role in the incidence and severity of respiratory disease.« less

  2. Geology and mineral deposits of an area in the Departments of Antioquia and Caldas (Subzone IIB), Colombia

    USGS Publications Warehouse

    Feininger, Tomas; Barrero L., Dario; Castro, Nestor; Hall, R.B.

    1973-01-01

    The Inventario Minero National (IMN), a four-year cooperative geologic mapping and mineral resources appraisal project, was accomplished under an agreement between the Republic of Colombia and the U. S. Agency for International Development from 1964 through 1969. Subzone IIB, consisting essentially of the east half of Zone comprises nearly 20,000 km2 principally in the Department of Antioquia but including also small parts of the Departments of Caldas and Tolima. The rocks in IIB range from Precambrian to Holocene. Precambrian feldspar-quartz gneiss occupies a mosaic of fault-bounded blocks intruded by igneous rocks between the Oto fault and the Rio Magdalena. Paleozoic rocks are extensive, and include lightly metamorphosed graptolite-bearing Ordovician shale at Cristalina, and a major suite of graphitic quartz-mica schist, feldspathic and aluminous gneiss, quartzite, marble, amphibolite, and other rocks. Syntectonic intrusive gneiss included many of the older rocks during a late Paleozoic(?) orogeny, which was accompanied by Abukuma-type metamorphosing from lowermost greenschist to upper amphibolite facies. A Jurassic diorite pluton bounded by faults cuts volcanic rocks of unknown age east of the Otu fault. Cretaceous rocks are major units. Middle Cretaceous carbonaceous shale, sandstone, graywacke, conglomerate, and volcanic rocks are locally prominent. The Antioquian batholith (quartz diorite) of Late Cretaceous age cuts the middle Cretaceous and older rocks. A belt of Tertiary nonmarine clastic sedimentary rocks crops out along the Magdalena Valley. Patches of Tertiary alluvium are locally preserved in the mountains. Quaternary alluvium, much of it auriferous, is widespread in modern stream valleys. Structurally IIB constitutes part of a vast complex synclinorium intruded concordantly by syntectonic catazonal or mesozonal felsic plutons, and by the later epizonal post-tectonic Antioquian batholith. Previously unrecognized major wrench faults are outstanding

  3. Detection and Molecular Characterization of Zoonotic Poxviruses Circulating in the Amazon Region of Colombia, 2014

    PubMed Central

    Usme-Ciro, Jose A.; Paredes, Andrea; Walteros, Diana M.; Tolosa-Pérez, Erica Natalia; Laiton-Donato, Katherine; Pinzón, Maria del Carmen; Petersen, Brett W.; Gallardo-Romero, Nadia F.; Li, Yu; Wilkins, Kimberly; Davidson, Whitni; Gao, Jinxin; Patel, Nishi; Nakazawa, Yoshinori; Reynolds, Mary G.; Satheshkumar, P. S.; Emerson, Ginny L.

    2017-01-01

    During 2014, cutaneous lesions were reported in dairy cattle and farmworkers in the Amazon Region of western Colombia. Samples from 6 patients were analyzed by serologic and PCR testing, and results demonstrated the presence of vaccinia virus and pseudocowpox virus. These findings highlight the need for increased poxvirus surveillance in Colombia. PMID:28322708

  4. 78 FR 15343 - Multi-State, Multi-Sector Trade Mission to Colombia; September 9-12, 2013

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-11

    ... for intellectual property rights (IPR). Colombia's traditional acceptance of U.S. brands as well as U... Colombia as an export destination. With more than 45 million people, an improved security environment, an... participation in the labor market has increased over 11% in the past five years; Use of free trade zones for...

  5. Sandfly Lutzomyia longipalpis in a Cutaneous leishmaniasis focus in central Colombia.

    PubMed

    López, Y; Osorio, L; Alvarez, G; Rojas, J; Jiménez, F; Gómez, C; Ferro, C

    1996-01-01

    Lutzomyia longipalpis, 15 other species of the genus Lutzomyia, and one species of Brumptomyia were collected in an endemic focus of cutaneous leishmaniasis in a river canyon 450 m above sea-level, in Rio Claro, Antioquia, Colombia. The presence of Lu. longipalpis is associated with the destruction of the primary forest and the development of new farmland and rural settlement in this region. The composition of species identified a different habitat for Lu. longipalpis in Colombia. Lu. yuilli and Lu. longipalpis were predominant (68.26%) followed by Lu. trapidoi, Lu. hartmani, Lu. triramula, Lu. panamensis, Lu. gomezi.

  6. Landslide Buries Valley of the Geysers

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Geysers are a rare natural phenomena found only in a few places, such as New Zealand, Iceland, the United States (Yellowstone National Park), and on Russia's far eastern Kamchatka Peninsula. On June 3, 2007, one of these rare geyser fields was severely damaged when a landslide rolled through Russia's Valley of the Geysers. The landslide--a mix of mud, melting snow, trees, and boulders--tore a scar on the land and buried a number of geysers, thermal pools, and waterfalls in the valley. It also blocked the Geyser River, causing a new thermal lake to pool upstream. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this infrared-enhanced image on June 11, 2007, a week after the slide. The image shows the valley, the landslide, and the new thermal lake. Even in mid-June, just days from the start of summer, the landscape is generally covered in snow, though the geologically heated valley is relatively snow free. The tree-covered hills are red (the color of vegetation in this false-color treatment), providing a strong contrast to the aquamarine water and the gray-brown slide. According to the Russian News and Information Agency (RIA) [English language], the slide left a path roughly a kilometer and a half (one mile) long and 200 meters (600 feet) wide. Within hours of the landslide, the water in the new lake inundated a number of additional geysers. The geysers directly buried under the landslide now lie under as much as 60 meters (180 feet) of material, according to RIA reports. It is unlikely that the geysers will be able to force a new opening through this thick layer, adds RIA. Among those directly buried is Pervenets (Firstborn), the first geyser found in the valley, in 1941. Other geysers, such as the Bolshoi (Greater) and Maly (Lesser) Geysers, were silenced when buried by water building up behind the new natural dam. According to Vladimir and Andrei Leonov of the Russian Federation Institute of

  7. Delineation of the Pahute Mesa–Oasis Valley groundwater basin, Nevada

    USGS Publications Warehouse

    Fenelon, Joseph M.; Halford, Keith J.; Moreo, Michael T.

    2016-01-22

    This report delineates the Pahute Mesa–Oasis Valley (PMOV) groundwater basin, where recharge occurs, moves downgradient, and discharges to Oasis Valley, Nevada. About 5,900 acre-feet of water discharges annually from Oasis Valley, an area of springs and seeps near the town of Beatty in southern Nevada. Radionuclides in groundwater beneath Pahute Mesa, an area of historical underground nuclear testing at the Nevada National Security Site, are believed to be migrating toward Oasis Valley. Delineating the boundary of the PMOV groundwater basin is necessary to adequately assess the potential for transport of radionuclides from Pahute Mesa to Oasis Valley.The PMOV contributing area is defined based on regional water-level contours, geologic controls, and knowledge of adjacent flow systems. The viability of this area as the contributing area to Oasis Valley and the absence of significant interbasin flow between the PMOV groundwater basin and adjacent basins are shown regionally and locally. Regional constraints on the location of the contributing area boundary and on the absence of interbasin groundwater flow are shown by balancing groundwater discharges in the PMOV groundwater basin and adjacent basins against available water from precipitation. Internal consistency for the delineated contributing area is shown by matching measured water levels, groundwater discharges, and transmissivities with simulated results from a single-layer, steady-state, groundwater-flow model. An alternative basin boundary extending farther north than the final boundary was rejected based on a poor chloride mass balance and a large imbalance in the northern area between preferred and simulated recharge.

  8. Climate controls on valley fever incidence in Kern County, California

    NASA Astrophysics Data System (ADS)

    Zender, Charles S.; Talamantes, Jorge

    2006-01-01

    Coccidiodomycosis (valley fever) is a systemic infection caused by inhalation of airborne spores from Coccidioides immitis, a soil-dwelling fungus found in the southwestern United States, parts of Mexico, and Central and South America. Dust storms help disperse C. immitis so risk factors for valley fever include conditions favorable for fungal growth (moist, warm soil) and for aeolian soil erosion (dry soil and strong winds). Here, we analyze and inter-compare the seasonal and inter-annual behavior of valley fever incidence and climate risk factors for the period 1980-2002 in Kern County, California, the US county with highest reported incidence. We find weak but statistically significant links between disease incidence and antecedent climate conditions. Precipitation anomalies 8 and 20 months antecedent explain only up to 4% of monthly variability in subsequent valley fever incidence during the 23 year period tested. This is consistent with previous studies suggesting that C. immitis tolerates hot, dry periods better than competing soil organisms and, as a result, thrives during wet periods following droughts. Furthermore, the relatively small correlation with climate suggests that the causes of valley fever in Kern County could be largely anthropogenic. Seasonal climate predictors of valley fever in Kern County are similar to, but much weaker than, those in Arizona, where previous studies find precipitation explains up to 75% of incidence. Causes for this discrepancy are not yet understood. Higher resolution temporal and spatial monitoring of soil conditions could improve our understanding of climatic antecedents of severe epidemics.

  9. Dawn in the Apollo Valley

    NASA Image and Video Library

    2013-12-18

    Beam Wave Guide antennas at Goldstone, known as the Beam Waveguide Cluster. They are located in an area at Goldstone called Apollo Valley. The Goldstone Deep Space Communications Complex is located in the Mojave Desert in California, USA.

  10. View From Within 'Perseverance Valley' on Mars (Enhanced Color)

    NASA Image and Video Library

    2017-12-06

    This enhanced-color view from within "Perseverance Valley," on the inner slope of the western rim of Endurance Crater on Mars, includes wheel tracks from the Opportunity rover's descent of the valley. The Panoramic Camera (Pancam) on Opportunity's mast took the component images of the scene during the period Sept. 4 through Oct. 6, 2017, corresponding to sols (Martian days) 4840 through 4871 of the rover's work on Mars. Perseverance Valley is a system of shallow troughs descending eastward about the length of two football fields from the crest of the crater rim to the floor of the crater. This panorama spans from northeast on the left to northwest on the right, including portions of the crater floor (eastward) in the left half and of the rim (westward) in the right half. Opportunity began descending Perseverance Valley in mid-2017 (see map) as part of an investigation into how the valley formed. Rover wheel tracks are darker brown, between two patches of bright bedrock, receding toward the horizon in the right half of the scene. This view combines multiple images taken through three different Pancam filters. The selected filters admit light centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). The three color bands are combined here with enhancement to make differences in surface materials easier to see. A map and full-resolution TIFF file are available at https://photojournal.jpl.nasa.gov/catalog/PIA22073

  11. Smokefree implementation in Colombia: Monitoring, outside funding, and business support

    PubMed Central

    Uang, Randy; Crosbie, Eric; Glantz, Stanton A

    2017-01-01

    Objective To analyze successful national smokefree policy implementation in Colombia, a middle income country. Materials and methods Key informants at the national and local levels were interviewed and news sources and government ministry resolutions were reviewed. Results Colombia’s Ministry of Health coordinated local implementation practices, which were strongest in larger cities with supportive leadership. Nongovernmental organizations provided technical assistance and highlighted noncompliance. Organizations outside Colombia funded some of these efforts. The bar owners’ association provided concerted education campaigns. Tobacco interests did not openly challenge implementation. Conclusions Health organization monitoring, external funding, and hospitality industry support contributed to effective implementation, and could be cultivated in other low and middle income countries. PMID:28562713

  12. Giant magnetic splitting inducing near-unity valley polarization in van der Waals heterostructures.

    PubMed

    Nagler, Philipp; Ballottin, Mariana V; Mitioglu, Anatolie A; Mooshammer, Fabian; Paradiso, Nicola; Strunk, Christoph; Huber, Rupert; Chernikov, Alexey; Christianen, Peter C M; Schüller, Christian; Korn, Tobias

    2017-11-16

    Monolayers of semiconducting transition metal dichalcogenides exhibit intriguing fundamental physics of strongly coupled spin and valley degrees of freedom for charge carriers. While the possibility of exploiting these properties for information processing stimulated concerted research activities towards the concept of valleytronics, maintaining control over spin-valley polarization proved challenging in individual monolayers. A promising alternative route explores type II band alignment in artificial van der Waals heterostructures. The resulting formation of interlayer excitons combines the advantages of long carrier lifetimes and spin-valley locking. Here, we demonstrate artificial design of a two-dimensional heterostructure enabling intervalley transitions that are not accessible in monolayer systems. The resulting giant effective g factor of -15 for interlayer excitons induces near-unity valley polarization via valley-selective energetic splitting in high magnetic fields, even after nonselective excitation. Our results highlight the potential to deterministically engineer novel valley properties in van der Waals heterostructures using crystallographic alignment.

  13. Hydrogeologic framework of the Wood River Valley aquifer system, south-central Idaho

    USGS Publications Warehouse

    Bartolino, James R.; Adkins, Candice B.

    2012-01-01

    The Wood River Valley contains most of the population of Blaine County and the cities of Sun Valley, Ketchum, Hailey, and Bellevue. This mountain valley is underlain by the alluvial Wood River Valley aquifer system, which consists primarily of a single unconfined aquifer that underlies the entire valley, an underlying confined aquifer that is present only in the southernmost valley, and the confining unit that separates them. The entire population of the area depends on groundwater for domestic supply, either from domestic or municipal-supply wells, and rapid population growth since the 1970s has caused concern about the long-term sustainability of the groundwater resource. As part of an ongoing U.S. Geological Survey effort to characterize the groundwater resources of the Wood River Valley, this report describes the hydrogeologic framework of the Wood River Valley aquifer system. Although most of the Wood River Valley aquifer system is composed of Quaternary-age sediments and basalts of the Wood River Valley and its tributaries, older igneous, sedimentary, or metamorphic rocks that underlie these Quaternary deposits also are used for water supply. It is unclear to what extent these rocks are hydraulically connected to the main part of Wood River Valley aquifer system and thus whether they constitute separate aquifers. Paleozoic sedimentary rocks in and near the study area that produce water to wells and springs are the Phi Kappa and Trail Creek Formations (Ordovician and Silurian), the Milligen Formation (Devonian), and the Sun Valley Group including the Wood River Formation (Pennsylvanian-Permian) and the Dollarhide Formation (Permian). These sedimentary rocks are intruded by granitic rocks of the Late Cretaceous Idaho batholith. Eocene Challis Volcanic Group rocks overlie all of the older rocks (except where removed by erosion). Miocene Idavada Volcanics are found in the southern part of the study area. Most of these rocks have been folded, faulted, and

  14. A Progressive Black Top Hat Transformation Algorithm for Estimating Valley Volumes from DEM Data

    NASA Astrophysics Data System (ADS)

    Luo, W.; Pingel, T.; Heo, J.; Howard, A. D.

    2013-12-01

    The amount of valley incision and valley volume are important parameters in geomorphology and hydrology research, because they are related to the amount erosion (and thus the volume of sediments) and the amount of water needed to create the valley. This is not only the case for terrestrial research but also for planetary research as such figuring out how much water was on Mars. With readily available digital elevation model (DEM) data, the Black Top Hat (BTH) transformation, an image processing technique for extracting dark features on a variable background, has been applied to DEM data to extract valley depth and estimate valley volume. However, previous studies typically use one single structuring element size for extracting the valley feature and one single threshold value for removing noise, resulting in some finer features such as tributaries not being extracted and underestimation of valley volume. Inspired by similar algorithms used in LiDAR data analysis to separate above ground features and bare earth topography, here we propose a progressive BTH (PBTH) transformation algorithm, where the structuring elements size is progressively increased to extract valleys of different orders. In addition, a slope based threshold was introduced to automatically adjust the threshold values for structuring elements with different sizes. Connectivity and shape parameters of the masked regions were used to keep the long linear valleys while removing other smaller non-connected regions. Preliminary application of the PBTH to Grand Canyon and two sites on Mars has produced promising results. More testing and fine-tuning is in progress. The ultimate goal of the project is to apply the algorithm to estimate the volume of valley networks on Mars and the volume of water needed to form the valleys we observe today and thus infer the nature of the hydrologic cycle on early Mars. The project is funded by NASA's Mars Data Analysis program.

  15. Developing the Intercultural Perspective in Foreign Language Teaching in Colombia: A Review of Six Journals

    ERIC Educational Resources Information Center

    Álvarez Valencia, José Aldemar

    2014-01-01

    The steadfast spread of English as the dominant world language has heightened the need to integrate culture in the foreign language teaching (FLT) curriculum, but how does this process crystallize in countries such as Colombia? The results of this review provide insight on the status of the intercultural perspective in FLT in Colombia by looking…

  16. Recharge of valley-fill aquifers in the glaciated northeast from upland runoff

    USGS Publications Warehouse

    Williams, J.H.; Morrissey, D.J.

    1996-01-01

    Channeled and unchanneled runoff from till-covered bedrock uplands is a major source of recharge to valley-fill aquifers in the glaciated northeastern United States. Streamflow measurements and model simulation of average steady-state conditions indicate that upland runoff accounted for more recharge to two valley-fill aquifers in moderately high topographic-relief settings than did direct infiltration of precipitation. Recharge from upland runoff to a modeled valley-fill aquifer in an area of lower relief was significant but less than that from direct infiltration of precipitation. The amount of upland runoff available for recharging valley-fill aquifers in the glaciated Northeast ranges from about 1.5 to 2.5 cubic feet per second per square mile of drainage area that borders the aquifer. Stream losses from tributaries that drain the uplands commonly range from 0.3 to 1.5 cubic feet per second per 1,000 feet of wetted channel where the tributaries cross alluvial fans in the main valleys. Recharge of valley-fill aquifers from channeled runoff was estimated from measured losses and average runoff rates and was represented in aquifer models as specified fluxes or simulated by head-dependent fluxes with streamflow routing in the model cells that represent the tributary streams. Unchanneled upland runoff, which includes overland and subsurface flow, recharges the valley-fill aquifers at the contact between the aquifer and uplands near the base of the bordering till-covered hillslopes. Recharge from unchanneled runoff was estimated from average runoff rates and the hillslope area that borders the aquifer and was represented as specified fluxes to model-boundary cells along the valley walls.

  17. Impacts of El Niño and El Niño Modoki on the precipitation in Colombia

    NASA Astrophysics Data System (ADS)

    Córdoba Machado, Samir; Palomino Lemus, Reiner; Raquel Gámiz Fortis, Sonia; Castro Díez, Yolanda; Jesús Esteban Parra, María

    2015-04-01

    The influence of the tropical Pacific SST on precipitation in Colombia is examined using 341 stations covering the period 1979-2009. Through a Singular Value Decomposition (SVD) the two main coupled variability modes show SST patterns clearly associated with El Niño (EN) and El Niño Modoki (ENM), respectively, presenting great coupling strength with the corresponding seasonal precipitation modes in Colombia. The results reveal that, mainly in winter and summer, EN and ENM events are associated with a significant rainfall decrease over northern, central, and western Colombia. The opposite effect occurs in some localities during spring, summer, and autumn. The southwestern region of Colombia exhibits an opposite behaviour connected to EN and ENM events during years when both events do not coexist, showing that the seasonal precipitation response is not linear. The Partial Regression Analysis used to quantify separately the influence of the two types of ENSO on seasonal precipitation shows the importance of both types in the reconstruction process. The results obtained in this study establish the base for modeling and forecasting the seasonal precipitation in Colombia using the tropical Pacific SST associated with El Niño and El Niño Modoki. Keywords: Seasonal precipitation, Tropical Pacific SST, El Niño, El Niño Modoki, Singular Value Decomposition, Colombia. ACKNOWLEDGEMENTS This work has been financed by the projects P11-RNM-7941 (Junta de Andalucía-Spain) and CGL2013-48539-R (MINECO-Spain, FEDER).

  18. Utilizing Lidar Data for Detection of Channel Migration: Taylor Valley, Antarctica

    NASA Astrophysics Data System (ADS)

    Barlow, M. C.; Telling, J. W.; Glennie, C.; Fountain, A.

    2017-12-01

    The McMurdo Dry Valleys is the largest ice-free expanse in Antarctica and one of the most studied regions on the continent. The valleys are a hyper-arid, cold-polar desert that receives little precipitation (<50 mm weq yr-1). The valley bottoms are covered in a sandy-gravel, dotted with ice-covered lakes and ponds, and alpine glaciers that descend from the surrounding mountains. Glacial melt feeds the lakes via ephemeral streams that flow 6 - 10 weeks each summer. Field observations indicate that the valley floors, particularly in Taylor Valley, contain numerous abandoned stream channels but, given the modest stream flows, channel migration is rarely observed. Only a few channels have been surveyed in the field due to the slow pace of manual methods. Here we present a method to assess channel migration over a broad region in order to study the pattern of channel migration as a function of climatic and/or geologic gradients in Taylor Valley. Raster images of high-resolution topography were created from two lidar (Light Detection and Ranging) datasets and were used to analyze channel migration in Taylor Valley. The first lidar dataset was collected in 2001 by NASA's Airborne Topographic Mapper (ATM) and the second was collected by the National Center for Airborne Laser Mapping (NCALM) in 2014 with an Optech Titan Sensor. The channels were extracted for each dataset using GeoNet, which is an open source tool used for the automatic extraction of channel networks. Channel migration was found to range from 0 to 50 cm per year depending upon the location. Channel complexity was determined based on the change in the number of channel branches and their length. We present the results for various regions in Taylor Valley with differing degrees of stream complexity. Further research is being done to determine factors that drive channel migration rates in this unique environment.

  19. 2. SNAKE RIVER VALLEY IRRIGATION DISTRICT DAM, PHOTOGRAPHIC COPY OF ...

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

    2. SNAKE RIVER VALLEY IRRIGATION DISTRICT DAM, PHOTOGRAPHIC COPY OF DRAWING, PLAN, SHEET 5 OF 5, 1924 (on file at the Idaho State Office of Water Resources, Boise, Idaho) - Snake River Valley Irrigation District, East Side of Snake River (River Mile 796), Shelley, Bingham County, ID

  20. South entrance, plan, section, & detail. San Bernardino Valley Union ...

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

    South entrance, plan, section, & detail. San Bernardino Valley Union Junior College, Science Building. Detailed drawings of tile work, wrought iron, and art stone, Howard E. Jones, Architect, San Bernardino, California. Sheet 6, job no. 311. Scale 1.2 inch to the foot. February 15, 1927. - San Bernardino Valley College, Life Science Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA