Sample records for acero estructural propensas

  1. "Estudio tribologico de aceros para moldes. Aplicacion al moldeo por inyeccion de polibutilentereftalato reforzado con fibra de vidrio"

    NASA Astrophysics Data System (ADS)

    Martinez Mateo, Isidoro Jose

    fabricacion del molde, tienen una gran influencia sobre su comportamiento en servicio a lo largo de la vida util del molde. En la primera parte del presente estudio, a partir de ensayos punzon sobre disco, se ha determinado la relacion entre la resistencia al desgaste y la dureza de aceros para moldes obtenidos a partir de bloques de gran espesor, estudiando los principales mecanismos de desgaste que tienen lugar. A continuacion, con el fin de determinar el dano superficial que sufren los aceros para moldes en condiciones reales de inyeccion, se han estudiado distintos tipos de aceros utilizados comercialmente en moldes de inyeccion de polimeros y materiales compuestos, seleccionando las condiciones de operacion para determinar la variacion de la rugosidad superficial del acero en funcion del material inyectado, del numero de operaciones sucesivas de inyeccion y de la orientacion del flujo de inyeccion, mediante tecnicas de perfilometria optica y microscopia electronica de barrido. Ademas del dano superficial sufrido por el acero con el numero de piezas inyectadas, tambien se ha determinado la evolucion de la rugosidad superficial de los materiales inyectados, polibutilentereftalato (PBT) puro y materiales compuestos derivados de PBT por adicion de un 20 o un 50% en peso de fibra de vidrio. En el caso de las piezas inyectadas, se ha caracterizado su microestructura en funcion del flujo de inyeccion y de la densidad de fibra, se han determinado sus propiedades termicas y dinamico-mecanicas, asi como la variacion de la rugosidad superficial de las piezas inyectadas con el numero de operaciones de inyeccion y con la geometria de las distintas secciones de las piezas. Finalmente, se ha evaluado la resistencia a la abrasion de PBT reforzado con un 50% de fibra, en funcion del numero de piezas inyectadas y de la direccion de rayado con respecto a la orientacion del flujo de inyeccion.

  2. Mapa de Vulnerabilidad en Honduras

    NASA Astrophysics Data System (ADS)

    Sánchez, A. A.

    2013-05-01

    Dado que Honduras geográficamente se encuentra en una zona que esta expuesta a diferentes fenómenos sísmicos y climatológicos. Investigamos cuales son las zonas mas propensas a desastres naturales, la vulnerabilidad y el factor de resiliencia de la población de acuerdo a diferentes parámetros de estudio.

  3. Integrated Information Support System (IISS). Volume 8. User Interface Subsystem. Part 10. Graph Support System Unit Test Plan

    DTIC Science & Technology

    1990-09-30

    UTP 620344220 30 September 1990 Command Line form gfl MSG: Estructure closed apIcatic Figure 5-64b (AFTER) 5-132 UTP 620344220 30 September 1990 Command...620344220 30 September 1990 Comman Lineay form gf 1 MSG: Estructure 9 psted on workstation 1 at priority 1 applcatioo Figure 5-101a (BEFORE) 5-205 UTP

  4. 76 FR 39901 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Cooperative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... invoking the Act's provisions limiting the recovery of antitrust plaintiffs to actual damages under... NETHERLANDS; Tubos De Acero De Mexico S.A., Veracruz, MEXICO; Shell Oil Company, Houston, TX; and ExxonMobil Development Company, Houston, TX. The general area of FlawPRO-JIP's planned activity is to develop an enhanced...

  5. A comprehensive molecular phylogeny for the hornbills (Aves: Bucerotidae).

    PubMed

    Gonzalez, Juan-Carlos T; Sheldon, Ben C; Collar, Nigel J; Tobias, Joseph A

    2013-05-01

    The hornbills comprise a group of morphologically and behaviorally distinct Palaeotropical bird species that feature prominently in studies of ecology and conservation biology. Although the monophyly of hornbills is well established, previous phylogenetic hypotheses were based solely on mtDNA and limited sampling of species diversity. We used parsimony, maximum likelihood and Bayesian methods to reconstruct relationships among all 61 extant hornbill species, based on nuclear and mtDNA gene sequences extracted largely from historical samples. The resulting phylogenetic trees closely match vocal variation across the family but conflict with current taxonomic treatments. In particular, they highlight a new arrangement for the six major clades of hornbills and reveal that three groups traditionally treated as genera (Tockus, Aceros, Penelopides) are non-monophyletic. In addition, two other genera (Anthracoceros, Ocyceros) were non-monophyletic in the mtDNA gene tree. Our findings resolve some longstanding problems in hornbill systematics, including the placement of 'Penelopides exharatus' (embedded in Aceros) and 'Tockus hartlaubi' (sister to Tropicranus albocristatus). We also confirm that an Asiatic lineage (Berenicornis) is sister to a trio of Afrotropical genera (Tropicranus [including 'Tockus hartlaubi'], Ceratogymna, Bycanistes). We present a summary phylogeny as a robust basis for further studies of hornbill ecology, evolution and historical biogeography. Copyright © 2013. Published by Elsevier Inc.

  6. FAST's Discovery of a New Millisecond Pulsar (MSP) toward the Fermi-LAT unassociated source 3FGL J0318.1+0252

    NASA Astrophysics Data System (ADS)

    Wang, Pei; Li, Di; Zhu, Weiwei; Zhang, Chengmin; Yan, Jun; Hou, Xian; Clark, Colin J.; Saz Parkinson, Pablo M.; Michelson, Peter F.; Ferrara, Elizabeth C.; Thompson, David J.; Smith, David A.; Ray, Paul S.; Kerr, Matthew; Shen, Zhiqiang; Wang, Na; Fermi-LAT Collaboration

    2018-04-01

    The Five hundred-meter Aperture Spherical radio Telescope (FAST), operated by the National Astronomical Observatories, Chinese Academy of Sciences, has discovered a radio millisecond pulsar (MSP) coincident with the unassociated gamma-ray source 3FGL J0318.1+0252 (Acero et al. 2015 ApJS, 218, 23), also known as FL8Y J0318.2+0254 in the recently released Fermi Large Area Telescope (LAT) 8-year Point Source List (FL8Y).

  7. Fermi LAT detection of renewed and strong GeV gamma-ray flares from blazars PKS 0903-57 and PKS 0346-27

    NASA Astrophysics Data System (ADS)

    Ciprini, Stefano

    2018-05-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed high-level gamma-ray activity from sources positionally consistent with the active galaxy PKS 0903-57 (also known as MRC 0903-573 and 3FGL J0904.8-5734, Acero et al. 2015, ApJS, 218, 23) and with the flat spectrum radio quasar PKS 0346-27 (also known as OE -278, TXS 0346-279, MRC 0346-279 and 3FGL J0348.6-2748).

  8. Fermi LAT detection of renewed strong GeV activity from the FSRQ 3C 279

    NASA Astrophysics Data System (ADS)

    Ojha, Roopesh; van Zyl, Pfesesani; Fermi Large Area Telescope Collaboration

    2018-04-01

    The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has observed an intense and hard gamma-ray flare from a source positionally consistent with the flat spectrum radio quasar 3C 279, also known as 3FGL J1256.1-0547 (Acero et al. 2015, ApJS, 218, 23), with radio coordinates R.A.: 12h56m11.1665s, Dec: -05d47m21.523s (J2000.0; Johnston et al. 1995, AJ, 110, 880).

  9. Estudio del comportamiento tribologico y de las interacciones de superficie de nuevos nanofluidos ionicos

    NASA Astrophysics Data System (ADS)

    Espinosa Rodriguez, Tulia

    tribocorrosion processes. The formation of a coating layer on magnesium alloys from phosphonate imidazolium ionic liquids by immersion and by chronoamperometry has been described. The new coatings reduce the abrasive wear in the magnesium-aluminium alloy but they are not effective in the magnesium-zinc alloy, which prevent the formation of continuous coatings. Los liquidos ionicos son sales liquidas a temperatura ambiente o bajas temperaturas que presentan excelentes propiedades fisico-quimicas. En el presente trabajo se estudian como lubricantes en problemas tribologicos complejos como la lubricacion de metales contra si mismos, el desarrollo de lubricantes base agua y de nuevas superficies autolubricadas. Cuando no es posible reducir la friccion y desgaste mediante lubricacion, como en las aleaciones de magnesio, los liquidos ionicos se han estudiado como precursores de recubrimientos protectores. Se han determinado las interacciones superficiales y los procesos de corrosion sobre cobre y sobre acero con diferentes liquidos ionicos proticos y aproticos para desarrollar nuevos lubricantes y aditivos. En el contacto cobre/cobre, excepto el liquido ionico protico derivado del oleato, todos los liquidos ionicos estudiados presentan mejor comportamiento tribologico que el lubricante comercial Polialfaolefina 6. En el contacto acero/zafiro, los nuevos liquidos ionicos proticos son buenos lubricantes cuando se utilizan en estado puro, y, como aditivos en agua, generan peliculas adsorbidas sobre la superficie del metal reduciendo la friccion y el desgaste tras la evaporacion del agua. Para evitar el periodo de alta friccion inicial en presencia de agua, se han generado peliculas superficiales de liquido ionico sobre el acero en condiciones estaticas. El mejor comportamiento lubricante tanto en el contacto cobre/cobre como en el contacto acero/zafiro se obtiene para el liquido ionico protico derivado del anion adipato, con dos grupos carboxilicos. Las interacciones de los grupos

  10. Intraspecific rearrangement of duplicated mitochondrial control regions in the Luzon Tarictic Hornbill Penelopides manillae (Aves: Bucerotidae).

    PubMed

    Sammler, Svenja; Ketmaier, Valerio; Havenstein, Katja; Tiedemann, Ralph

    2013-12-01

    Philippine hornbills of the genera Aceros and Penelopides (Bucerotidae) are known to possess a large tandemly duplicated fragment in their mitochondrial genome, whose paralogous parts largely evolve in concert. In the present study, we surveyed the two distinguishable duplicated control regions in several individuals of the Luzon Tarictic Hornbill Penelopides manillae, compare their characteristics within and across individuals, and report on an intraspecific mitochondrial gene rearrangement found in one single specimen, i.e., an interchange between the two control regions. To our knowledge, this is the first observation of two distinct mitochondrial genome rearrangements within a bird species. We briefly discuss a possible evolutionary mechanism responsible for this pattern, and highlight potential implications for the application of control region sequences as a marker in population genetics and phylogeography.

  11. Discovery of a Fanaroff-Riley type 0 radio galaxy emitting at γ-ray energies

    NASA Astrophysics Data System (ADS)

    Grandi, Paola; Capetti, Alessandro; Baldi, Ranieri D.

    2016-03-01

    We present supporting evidence for the first association of a Fermi source, 3FGLJ1330.0-3818, Acero et al. (2015) with the Fanaroff-Riley type 0 (FR 0) radio galaxy Tol1326-379. FR 0s represent the majority of the local population of radio-loud active galactic nuclei but their nature is still unclear. They share the same nuclear and host properties as FR Is, but they show a large deficit of extended radio emission. Here we show that FR 0s can emit photons at very high energies. Tol1326-379 has a GeV luminosity of L>1 GeV ˜ 2 × 1042 erg s-1, typical of FR Is, but with a steeper γ-ray spectrum (Γ = 2.78 ± 0.14). This could be related to the intrinsic jet properties but also to a different viewing angle.

  12. Occurrence of Cryptosporidium oocysts in Wrinkled Hornbill and other birds in the Kuala Lumpur National Zoo.

    PubMed

    Rohela, M; Lim, Y A L; Jamaiah, I; Khadijah, P Y Y; Laang, S T; Nazri, M H Mohd; Nurulhuda, Z

    2005-01-01

    The occurrence of a coccidian parasite, Cryptosporidium, among birds in the Kuala Lumpur National Zoo was investigated in this study. A hundred bird fecal samples were taken from various locations of the zoo. Fecal smears prepared using direct smear and formalin ethyl acetate concentration technique were stained with modified Ziehl-Neelsen stain. Samples positive for Cryptosporidium with Ziehl-Neelsen stain were later confirmed using the immunofluorescence technique and viewed under the epifluorescence microscope. Six species of bird feces were confirmed positive with Cryptosporidium oocysts. They included Wrinkled Hornbill (Aceros corrugatus), Great Argus Pheasant (Argusianus argus), Black Swan (Cygnus atratus), Swan Goose (Anser cygnoides), Marabou Stork (Leptoptilos crumeniferus), and Moluccan Cockatoo (Cacatua moluccencis). These birds were located in the aviary and lake, with the Moluccan Cockatoo routinely used as a show bird. Results obtained in this study indicated that animal sanctuaries like zoos and bird parks are important sources of Cryptosporidium infection to humans, especially children and other animals.

  13. Fermi LAT detection of an increase in gamma-ray activity of the FSRQ S5 1044+71

    NASA Astrophysics Data System (ADS)

    Ojha, Roopesh; Carpen, Bryce

    2017-01-01

    The Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope, has observed gamma-ray flaring activity from a source positionally consistent with the flat spectrum radio quasar S5 1044+71 (also known as 3FGL J1048.4+7144, Acero et al. 2015, ApJS 218, 23) with radio coordinates R.A: 10h48m27.6199s, Dec: +71d43m35.938s (J2000; Johnston et al. 1995, AJ, 110, 880) and redshift z=1.15 (Polatidis et al. 1995, ApJS, 98, 1). Preliminary results indicate that S5 1044+71 showed a marked increase in activity on 2016 December 29, with a daily flux (E > 100 MeV) of (1.1+/-0.2) x10^-6 ph cm^-2 s^-1 (errors are statistical only) which is a factor of about 16 greater than the average flux reported in the third Fermi LAT catalog (3FGL).

  14. ["I say no, she says yes": matrimonial violence according to male speech].

    PubMed

    Alves, Sandra Lúcia Belo; Diniz, Normélia Maria Freire

    2005-01-01

    This study aims to analize the violence between couples from the man's point of view. We adopted a qualitative methodology approach having as reference the Social Representation Theory. Ten adult men took part in the survey. They live in the Calafate community, in San Martin, Salvador-BA and had a relationship for at least 2 years. In order to collect the data, a semi-estructured interview was used. As a result, it was observed that the respondents agree directly with the process of men and women's socialization in order to define the way husband and wife behave in a relationship. This is an asymetric and hierarchical perspective, where the masculine tendencies are defined by the society, as well as the women's undefined social role. These two motives are pointed out as the explanation for the violence between couples.

  15. Burnout and depression among Spanish periodontology practitioners.

    PubMed

    Ríos-Santos, Jose-Vicente; Reyes-Torres, Mercedes; López-Jiménez, Ana; Morillo-Velázquez, Juan-Manuel; Bullón, Pedro

    2010-09-01

    The objective of this study was to determine the prevalence of burnout syndrome and depression symptoms among periodontology practitioners, as well as the relationship with socio-demographic variables and work stress. A total of 284 subjects, members of the Spanish Society of Periodontology (SEPA), were selected for this study. The Spanish version of the Maslach Burnout Inventory (MBI) and the Tetradimensional Estructural Questionnaire for Depression (TEC-DE) were sent by post to all participants. Descriptive statistics in addition to mean comparison and chi-square test were used for data analysis. A response rate of 59.85% was obtained. From the total sample, 40% shows high levels of emotional exhaustion, 20% increased depersonalization and 11.20% diminished personal accomplishment. The prevalence of any depression symptom was nearly 16%. Moreover, higher prevalence was found among those practitioners not working a continuous shift and not practicing periodontology on an exclusive basis. Among Spanish periodontology practitioners, a high prevalence of burnout and depression exists.

  16. Fermi LAT detection of a GeV gamma-ray flare from blazar CGRaBS J0809+5341 (87GB 080551.6+535010)

    NASA Astrophysics Data System (ADS)

    Gasparrini, Dario

    2017-10-01

    The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray emission from a source positionally consistent with the flat spectrum radio quasar CGRaBS J0809+5341 (also known as 87GB 080551.6+535010, BZQ J0809+5341 and 3FGL J0809.5+5342) with radio coordinates (J2000) R.A.: 122.4238862 deg, Dec.: 53.6903033 deg (Petrov et al. 2011, AJ, 142, 89). This blazar has a redshift z = 2.133 (Healey et al. 2008, ApJS, 175, 97). Preliminary analysis indicates that on 2017 October 26, CGRaBS J0809+5341 was in a high state with a daily averaged gamma-ray flux (E > 100 MeV) of (0.23+/-0.15) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only), about 20 times greater than its four-year average flux reported in the third Fermi-LAT source catalog (3FGL, Acero et al. 2015, ApJS, 218, 23). Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue.

  17. Regulación del flujo sanguíneo uterino. II. Funciones de estrógeno y receptores estrogénicos α/β en acciones genómicas y no-genómicas del endotelio uterino *

    PubMed Central

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

    2015-01-01

    Resumen El embarazo está marcado por cambios y adaptaciones cardiovasculares que son importantes para el crecimiento y mantenimiento de la placenta y el feto. Durante este periodo, las adaptaciones vasculares uterinas manifiestan cambios clasificados como de corto o largo plazo los cuales están relacionados con adaptaciones vasodilatadoras, angiogénicas o de remodelación. El estrógeno y los receptores estrogénicos clásicos (REs), RE-α y RE-β, han demostrado ser parcialmente responsables por facilitar el incremento dramático en el fluido sanguíneo uterino necesario durante el embarazo. En ésta revisión bibliográfica se discuten la base estructural para la diversidad y selectividad funcional de los REs por el estrógeno, el papel de los REs sobre los efectos genómicos y no-genómicos en células endoteliales de arterias uterinas (CEAU). Estos temas integran el conocimiento científico sobre la regulación molecular de CEAU para mantener el incremento fisiológico en la perfusión útero-placentaria observada durante un embarazo normal. PMID:26113751

  18. First principles study of hydrogen adsorption on carbon nanowires.

    NASA Astrophysics Data System (ADS)

    Tapia, Alejandro; Aguilera, Luis; Murrieta, Gabriel; de Coss, Romeo

    2007-03-01

    Recently has been reported a new type of one-dimensional carbon structures. Carbon nanowires formed by a linear carbon-atom chain inside an armchair (5,5) carbon nanotube has been observed using high-resolution transmission electron microscopy. In the present work we have studied the changes in the electronic structure of a carbon nanowires and (5,5) single-walled carbon nanotubes (SWCN) when a hydrogen atom is adsorbed. We used the Density Functional Theory and the calculations where performed by the pseudopotentials LCAO method (SIESTA code) and the Generalized Gradient Approximation (GGA) for the exchange-correlation potential. We have analyzed the changes in the atomic structure, density of states (LDOS), and the local orbital population. We found charge transfer from the nanotube to the linear chain and the hydrogen atom, the electronic character of the chain and nanotube sub-systems in chain@SWCN is the same that in the corresponding isolated systems, chain or SWCN. But the hydrogen adsorption produced changes in the atomic estructure and the electronic properties. This research was supported by PRIORI-UADY under Grant No. FING-05-004 and Consejo Nacional de Ciencia y Tecnolog'ia (Conacyt) under Grants No. 43830-F and 49985-J.

  19. Linear lateral vibration of axisymmetric liquid briges

    NASA Astrophysics Data System (ADS)

    Ferrera, C.; Montanero, J. M.; Cabezas, M. G.

    A liquid bridge is a mass of liquid sustained by the action of the surface tension force between two parallel supporting disks Apart from their basic scientific interest a liquid bridge can be considered as the simplest idealization of the configuration appearing in the floating zone technique used for crystal growth and purification of high melting point materials footnote Messeguer et al emph Crystal Growth Res bf 5 27 1999 This has conferred considerable interest on the study of liquid bridges not only in fluid mechanics but also in the field of material engineering The axisymmetric dynamics of an isothermal liquid bridge has been frequently analysed over the past years The studies have considered different phenomena such as free oscillations footnote Montanero emph E J Mech B Fluids bf 22 169 2003 footnote Acero and Montanero emph Phys Fluids bf 17 078105 2005 forced vibrations footnote Perales and Messeguer emph Phys Fluids A bf 4 1110 1992 g-jitter effects footnote Messeguer and Perales emph Phys Fluids A bf 3 2332 1991 extensional deformation footnote Zhang et al emph J Fluid Mech bf 329 207 1996 and breakup process footnote Espino et al emph Phys Fluids bf 14 3710 2002 among others Works considering the nonaxisymmetric dynamical behaviour of a liquid bridge has been far less common footnote Sanz and Diez emph J Fluid Mech bf 205 503 1989 In the present study the linear vibration of an axisymmetric liquid

  20. Estudio teórico de moléculas de interés en Astrofísica: compuestos binarios policarbonados

    NASA Astrophysics Data System (ADS)

    Largo-Cabrerizo, A.

    Se han detectado en el espacio distintos compuestos binarios policarbonados (que se pueden formular como CnX), algunos de ellos con elementos de la primera fila del sistema periódico, pero también existen otros que contienen elementos de la segunda fila, como azufre o silicio. La información experimental sobre estos últimos compuestos es escasa, por lo que los estudios teóricos son especialmente valiosos en este campo. En esta comunicación presentaremos los avances mas recientes que sobre el tema ha realizado nuestro grupo. Incidiremos particularmente en dos aspectos. En primer lugar resumiremos los estudios en los que hemos intentado proporcionar información estructural sobre carburos metálicos formados por sodio, magnesio, aluminio o calcio, que pueda ser de ayuda a la hora de caracterizar estas moléculas en laboratorio como paso previo a su eventual detección en el espacio. Un aspecto importante dentro de este primer apartado es el análisis de las propiedades moleculares en función del tamaño del sistema (cuantificado en el numero de átomos de carbono) con el objeto de intentar sistematizar su estudio. En segundo lugar comentaremos brevemente algunos de los estudios realizados sobre posibles reacciones que pueden ser vías de síntesis de este tipo de compuestos en el medio interestelar.

  1. Perceptional gaps among women, husbands and family members about intentions for birthplace: a cross-sectional study.

    PubMed

    Shimpuku, Yoko; Madeni, Frida Elikana; Horiuchi, Shigeko; Leshabari, Sebalda Charles

    2017-01-30

    women are more likely to give birth at a health facility when their families agree with the birthplace. However, in rural areas of Tanzania, women are often marginalized from decision-making. This study predicted birthplace intention and identified factors to reduce perceptional gaps among pregnant women, husbands and family members. explanatory cross-sectional survey was conducted in three villages in North Eastern Tanzania. Participants were 138 pregnant women and their families who answered the Birth Intention Questionnaire (BIQ), measuring knowledge, attitude, perceived behavioral control, subjective norms and intention for birthplace. Descriptive analysis, ANOVA, Chi-square, and multiple linear regression was used to analyze the data. the regression model showed that knowledge, perceived behavioral control, and subjective norms predicted intention for birthplace (R2 = .28). While 81% of pregnant women thought their husbands were decision-makers for their birth, only 38% of husbands and 37% of family members agreed. Pregnant women had significantly lower scores on the item "I will prepare for childbirth with my family" compared with husbands (p < .01) and other family members (p < .001). providing evidence-based birth preparation and reducing the identified perceptual gaps may enhance women's intention to deliver at health facilities. as mulheres são mais propensas a dar à luz em um centro de saúde quando suas famílias estão de acordo com o local de nascimento. No entanto, nas áreas rurais da Tanzânia, as mulheres são muitas vezes marginalizadas do processo de decisão. Este estudo fez previsoes de intenção para o local do parto e fatores para reduzir as lacunas de percepção entre as mulheres grávidas, seus maridos e familiares identificados. estudo transversal explicativo realizado em três aldeias no nordeste da Tanzânia. Os participantes foram 138 mulheres grávidas e suas famílias que responderam ao Questionário de Intenção sobre Parto

  2. Use of deferiprone for the treatment of hepatic iron storage disease in three hornbills.

    PubMed

    Sandmeier, Peter; Clauss, Marcus; Donati, Olivio F; Chiers, Koen; Kienzle, Ellen; Hatt, Jean-Michel

    2012-01-01

    3 hornbills (2 Papua hornbills [Aceros plicatus] and 1 longtailed hornbill [Tockus albocristatus]) were evaluated because of general listlessness and loss of feather glossiness. Because hepatic iron storage disease was suspected, liver biopsy was performed and formalin-fixed liver samples were submitted for histologic examination and quantitative image analysis (QIA). Additional frozen liver samples were submitted for chemical analysis. Birds also underwent magnetic resonance imaging (MRI) under general anesthesia for noninvasive measurement of liver iron content. Serum biochemical analysis and analysis of feed were also performed. Results of diagnostic testing indicated that all 3 hornbills were affected with hepatic iron storage disease. The iron chelator deferiprone was administered (75 mg/kg [34.1 mg/lb], PO, once daily for 90 days). During the treatment period, liver biopsy samples were obtained at regular intervals for QIA and chemical analysis of the liver iron content and follow-up MRI was performed. In all 3 hornbills, a rapid and large decrease in liver iron content was observed. All 3 methods for quantifying the liver iron content were able to verify the decrease in liver iron content. Orally administered deferiprone was found to effectively reduce the liver iron content in these 3 hornbills with iron storage disease. All 3 methods used to monitor the liver iron content (QIA, chemical analysis of liver biopsy samples, and MRI) had similar results, indicating that all of these methods should be considered for the diagnosis of iron storage disease and monitoring of liver iron content during treatment.

  3. Recruitment of hornbill-dispersed trees in hunted and logged forests of the Indian Eastern Himalaya.

    PubMed

    Sethi, Pia; Howe, Henry F

    2009-06-01

    Hunting of hornbills by tribal communities is widespread in logged foothill forests of the Indian Eastern Himalaya. We investigated whether the decline of hornbills has affected the dispersal and recruitment of 3 large-seeded tree species. We hypothesized that 2 low-fecundity tree species, Chisocheton paniculatus and Dysoxylum binectariferum (Meliaceae) bearing arillate fruits, are more dispersal limited than a prolifically fruiting drupaceous tree Polyalthia simiarum (Annonaceae), which has potential dispersers other than hornbills. We estimated the abundance of large avian frugivores during the fruiting season along transects in 2 protected and 2 disturbed forests. We compared recruitment of the tree species near (<10 m) and far (10-40 m) from parent trees at protected and disturbed sites. Median abundance of Great (Buceros bicornis), Wreathed (Aceros undulatus), and Oriental Pied Hornbills (Anthracoceros albirostris) were significantly lower in disturbed forests, but sites did not differ in abundances of the Mountain Imperial Pigeon (Ducula badia). Overall, tree species showed more severely depressed recruitment of seedlings (77% fewer) and juveniles (69% fewer) in disturbed than in protected forests. In disturbed forests, 93% fewer seedlings of C. paniculatus were beyond parental crowns, and a high number of all seedlings (42%) accumulated directly under reproductive adults. In contrast, D. binectariferum and P. simiarum were recruitment rather than dispersal limited, with fewer dispersed seedlings surviving in disturbed than in protected forests. Results are consistent with the idea that disturbance disrupts mutualisms between hornbills and some large-seeded food plants, with the caveat that role redundancy within even small and specialized disperser assemblages renders other tree species less vulnerable to loss of regular dispersal agents. ©2009 Society for Conservation Biology.

  4. VizieR Online Data Catalog: MOJAVE. XIII. New 15GHz observations on 1994-2013 (Lister+, 2016)

    NASA Astrophysics Data System (ADS)

    Lister, M. L.; Aller, M. F.; Aller, H. D.; Homan, D. C.; Kellermann, K. I.; Kovalev, Y. Y.; Pushkarev, A. B.; Richards, J. L.; Ros, E.; Savolainen, T.

    2016-09-01

    Starting with the 2cm Very Long Baseline Array (VLBA) survey in 1994 (Kellermann et al. 1998AJ....115.1295K), and continuing with the MOJAVE (Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments) program (Lister et al. 2009, Cat. J/AJ/137/3718), we have carried out multi-epoch VLBA observations of several hundred of the brightest, most compact radio sources in the northern sky. In this paper, we present 1625 VLBA 15GHz contour maps of 295 AGNs for epochs between 1994 August 31 and 2013 August 20 that have not previously appeared in any paper from the MOJAVE (Lister & Homan 2005, Cat. J/AJ/130/1389; Lister et al. 2009, Cat. J/AJ/137/3718; Lister et al. 2013, Cat. J/AJ/146/120) or 2cm VLBA surveys (Kellermann et al. 1998AJ....115.1295K; Zensus et al. 2002AJ....124..662Z). These AGNs (see Table1) are from one or more of the following: the MOJAVE low-luminosity sample (Lister et al. 2013, Cat. J/AJ/146/120), the complete flux density-limited MOJAVE 1.5Jy sample (Lister et al. 2015, Cat. J/ApJ/810/L9), the VLBA 2cm survey (Kellermann et al. 1998AJ....115.1295K), the third EGRET gamma-ray catalog (Hartman et al. 1999, Cat. J/ApJS/123/79), or the 3FGL Fermi gamma-ray catalog (Acero et al. 2015, Cat. J/ApJS/218/23). Also included are some AGNs that were originally candidates for these samples, but did not meet the final selection criteria. We list the parameters of the contour maps in Table2. We modeled the (u, v) visibility data in Difmap (Shepherd 1997ASPC..125...77S) using a set of Gaussian features, which we list in Table3. We analyzed the kinematics of the robust Gaussian jet features in our sample using two methods. The results of these analyses are listed separately in Tables 4 and 5, respectively. (6 data files).

  5. Full mitochondrial genome sequences of two endemic Philippine hornbill species (Aves: Bucerotidae) provide evidence for pervasive mitochondrial DNA recombination.

    PubMed

    Sammler, Svenja; Bleidorn, Christoph; Tiedemann, Ralph

    2011-01-14

    Although nowaday it is broadly accepted that mitochondrial DNA (mtDNA) may undergo recombination, the frequency of such recombination remains controversial. Its estimation is not straightforward, as recombination under homoplasmy (i.e., among identical mt genomes) is likely to be overlooked. In species with tandem duplications of large mtDNA fragments the detection of recombination can be facilitated, as it can lead to gene conversion among duplicates. Although the mechanisms for concerted evolution in mtDNA are not fully understood yet, recombination rates have been estimated from "one per speciation event" down to 850 years or even "during every replication cycle". Here we present the first complete mt genome of the avian family Bucerotidae, i.e., that of two Philippine hornbills, Aceros waldeni and Penelopides panini. The mt genomes are characterized by a tandemly duplicated region encompassing part of cytochrome b, 3 tRNAs, NADH6, and the control region. The duplicated fragments are identical to each other except for a short section in domain I and for the length of repeat motifs in domain III of the control region. Due to the heteroplasmy with regard to the number of these repeat motifs, there is some size variation in both genomes; with around 21,657 bp (A. waldeni) and 22,737 bp (P. panini), they significantly exceed the hitherto longest known avian mt genomes, that of the albatrosses. We discovered concerted evolution between the duplicated fragments within individuals. The existence of differences between individuals in coding genes as well as in the control region, which are maintained between duplicates, indicates that recombination apparently occurs frequently, i.e., in every generation. The homogenised duplicates are interspersed by a short fragment which shows no sign of recombination. We hypothesize that this region corresponds to the so-called Replication Fork Barrier (RFB), which has been described from the chicken mitochondrial genome. As this RFB

  6. Mitochondrial control region I and microsatellite analyses of endangered Philippine hornbill species (Aves; Bucerotidae) detect gene flow between island populations and genetic diversity loss.

    PubMed

    Sammler, Svenja; Ketmaier, Valerio; Havenstein, Katja; Krause, Ulrike; Curio, Eberhard; Tiedemann, Ralph

    2012-10-12

    The Visayan Tarictic Hornbill (Penelopides panini) and the Walden's Hornbill (Aceros waldeni) are two threatened hornbill species endemic to the western islands of the Visayas that constitute - between Luzon and Mindanao - the central island group of the Philippine archipelago. In order to evaluate their genetic diversity and to support efforts towards their conservation, we analyzed genetic variation in ~ 600 base pairs (bp) of the mitochondrial control region I and at 12-19 nuclear microsatellite loci. The sampling covered extant populations, still occurring only on two islands (P. panini: Panay and Negros, A. waldeni: only Panay), and it was augmented with museum specimens of extinct populations from neighboring islands. For comparison, their less endangered (= more abundant) sister taxa, the Luzon Tarictic Hornbill (P. manillae) from the Luzon and Polillo Islands and the Writhed Hornbill (A. leucocephalus) from Mindanao Island, were also included in the study. We reconstructed the population history of the two Penelopides species and assessed the genetic population structure of the remaining wild populations in all four species. Mitochondrial and nuclear data concordantly show a clear genetic separation according to the island of origin in both Penelopides species, but also unravel sporadic over-water movements between islands. We found evidence that deforestation in the last century influenced these migratory events. Both classes of markers and the comparison to museum specimens reveal a genetic diversity loss in both Visayan hornbill species, P. panini and A. waldeni, as compared to their more abundant relatives. This might have been caused by local extinction of genetically differentiated populations together with the dramatic decline in the abundance of the extant populations. We demonstrated a loss in genetic diversity of P. panini and A. waldeni as compared to their sister taxa P. manillae and A. leucocephalus. Because of the low potential for gene flow

  7. Mitochondrial control region I and microsatellite analyses of endangered Philippine hornbill species (Aves; Bucerotidae) detect gene flow between island populations and genetic diversity loss

    PubMed Central

    2012-01-01

    Background The Visayan Tarictic Hornbill (Penelopides panini) and the Walden’s Hornbill (Aceros waldeni) are two threatened hornbill species endemic to the western islands of the Visayas that constitute - between Luzon and Mindanao - the central island group of the Philippine archipelago. In order to evaluate their genetic diversity and to support efforts towards their conservation, we analyzed genetic variation in ~ 600 base pairs (bp) of the mitochondrial control region I and at 12–19 nuclear microsatellite loci. The sampling covered extant populations, still occurring only on two islands (P. panini: Panay and Negros, A. waldeni: only Panay), and it was augmented with museum specimens of extinct populations from neighboring islands. For comparison, their less endangered (= more abundant) sister taxa, the Luzon Tarictic Hornbill (P. manillae) from the Luzon and Polillo Islands and the Writhed Hornbill (A. leucocephalus) from Mindanao Island, were also included in the study. We reconstructed the population history of the two Penelopides species and assessed the genetic population structure of the remaining wild populations in all four species. Results Mitochondrial and nuclear data concordantly show a clear genetic separation according to the island of origin in both Penelopides species, but also unravel sporadic over-water movements between islands. We found evidence that deforestation in the last century influenced these migratory events. Both classes of markers and the comparison to museum specimens reveal a genetic diversity loss in both Visayan hornbill species, P. panini and A. waldeni, as compared to their more abundant relatives. This might have been caused by local extinction of genetically differentiated populations together with the dramatic decline in the abundance of the extant populations. Conclusions We demonstrated a loss in genetic diversity of P. panini and A. waldeni as compared to their sister taxa P. manillae and A. leucocephalus. Because

  8. Full mitochondrial genome sequences of two endemic Philippine hornbill species (Aves: Bucerotidae) provide evidence for pervasive mitochondrial DNA recombination

    PubMed Central

    2011-01-01

    Background Although nowaday it is broadly accepted that mitochondrial DNA (mtDNA) may undergo recombination, the frequency of such recombination remains controversial. Its estimation is not straightforward, as recombination under homoplasmy (i.e., among identical mt genomes) is likely to be overlooked. In species with tandem duplications of large mtDNA fragments the detection of recombination can be facilitated, as it can lead to gene conversion among duplicates. Although the mechanisms for concerted evolution in mtDNA are not fully understood yet, recombination rates have been estimated from "one per speciation event" down to 850 years or even "during every replication cycle". Results Here we present the first complete mt genome of the avian family Bucerotidae, i.e., that of two Philippine hornbills, Aceros waldeni and Penelopides panini. The mt genomes are characterized by a tandemly duplicated region encompassing part of cytochrome b, 3 tRNAs, NADH6, and the control region. The duplicated fragments are identical to each other except for a short section in domain I and for the length of repeat motifs in domain III of the control region. Due to the heteroplasmy with regard to the number of these repeat motifs, there is some size variation in both genomes; with around 21,657 bp (A. waldeni) and 22,737 bp (P. panini), they significantly exceed the hitherto longest known avian mt genomes, that of the albatrosses. We discovered concerted evolution between the duplicated fragments within individuals. The existence of differences between individuals in coding genes as well as in the control region, which are maintained between duplicates, indicates that recombination apparently occurs frequently, i.e., in every generation. Conclusions The homogenised duplicates are interspersed by a short fragment which shows no sign of recombination. We hypothesize that this region corresponds to the so-called Replication Fork Barrier (RFB), which has been described from the chicken

  9. Conjuncion y contexto: Contenido semantico y valor estructural de "con que, conque" en el lenguaje de Calderon (Conjunction and Context: Semantic Context and Structural Value in "con que, conque" in Calderon's Literary Style)

    ERIC Educational Resources Information Center

    Flasche, Hans

    1973-01-01

    Special issue as a tribute to Dr. Arnold Reichenberger, a well-known Hispanist, who has served as chairman of the Department of Romance Languages at Pennsylvania State University, University Park, Pennsylvania. (DS)

  10. Inactivation of foodborne microorganisms using engineered water nanostructures (EWNS).

    PubMed

    Pyrgiotakis, Georgios; Vasanthakumar, Archana; Gao, Ya; Eleftheriadou, Mary; Toledo, Eduardo; DeAraujo, Alice; McDevitt, James; Han, Taewon; Mainelis, Gediminas; Mitchell, Ralph; Demokritou, Philip

    2015-03-17

    Foodborne diseases caused by the consumption of food contaminated with pathogenic microorganisms or their toxins have very serious economic and public health consequences. Here, we explored the effectiveness of a recently developed intervention method for inactivation of microorganisms on fresh produce, and food production surfaces. This method utilizes Engineered Water Nanostructures (EWNS) produced by electrospraying of water vapor. EWNS possess unique properties; they are 25 nm in diameter, remain airborne in indoor conditions for hours, contain Reactive Oxygen Species (ROS) and have very strong surface charge (on average 10 e/structure). Here, their efficacy in inactivating representative foodborne bacteria such as Escherichia coli, Salmonella enterica, and Listeria innocua, on stainless steel surfaces and on organic tomatoes, was assessed. The inactivation was facilitated using two different exposure approaches in order to optimize the delivery of EWNS to bacteria: (1) EWNS were delivered on the surfaces by diffusion and (2) a "draw through" Electrostatic Precipitator Exposure System (EPES) was developed and characterized for EWNS delivery to surfaces. Using the diffusion approach and an EWNS concentration of 24,000 #/cm3, the bacterial concentrations on the surfaces were reduced, depending on the bacterium and the surface type, by values ranging between 0.7 to 1.8 logs. Using the EPES approach and for an aerosol concentration of 50,000 #/cm3 at 90 min of exposure, results show a 1.4 log reduction for E. coli on organic tomato surfaces, as compared to the control (same conditions in regards to temperature and Relative Humidity). Furthermore, for L. innocua, the dose-response relationship was demonstrated and found to be a 0.7 and 1.2 logs removal at 12,000 and 23,000 #/cm3, respectively. The results presented here indicate that this novel, chemical-free, and environmentally friendly intervention method holds potential for development and application in the

  11. Estimation of Future Return Levels for Heavy Rainfall in the Iberian Peninsula: Comparison of Methodologies

    NASA Astrophysics Data System (ADS)

    Parey, S.

    2014-12-01

    F. J. Acero1, S. Parey2, T.T.H. Hoang2, D. Dacunha-Castelle31Dpto. Física, Universidad de Extremadura, Avda. de Elvas s/n, 06006, Badajoz 2EDF/R&D, 6 quai Watier, 78401 Chatou Cedex, France 3Laboratoire de Mathématiques, Université Paris 11, Orsay, France Trends can already be detected in daily rainfall amount in the Iberian Peninsula (IP), and this will have an impact on the extreme levels. In this study, we compare different ways to estimate future return levels for heavy rainfall, based on the statistical extreme value theory. Both Peaks over Threshold (POT) and block maxima with the Generalized Extreme Value (GEV) distribution will be used and their results compared when linear trends are assumed in the parameters: threshold and scale parameter for POT and location and scale parameter for GEV. But rainfall over the IP is a special variable in that a large number of the values are 0. Thus, the impact of taking this into account is discussed too. Another approach is then tested, based on the evolutions of the mean and variance obtained from the time series of rainy days only, and of the number of rainy days. A statistical test, similar to that designed for temperature in Parey et al. 2013, is used to assess if the trends in extremes can be considered as mostly due to these evolutions when considering only rainy days. The results show that it is mainly the case: the extremes of the residuals, after removing the trends in mean and standard deviation, cannot be differentiated from those of a stationary process. Thus, the future return levels can be estimated from the stationary return level of these residuals and an estimation of the future mean and standard deviation. Moreover, an estimation of the future number of rainy days is used to retrieve the return levels for all days. All of these comparisons are made for an ensemble of high quality rainfall time series observed in the Iberian Peninsula over the period 1961-2010, from which we want to estimate a 20-year

  12. EL PROTEOMA DEL TEJIDO ADIPOSO SUBCUTÁNEO MUESTRA HETEROGENEIDAD ANATÓMICA

    PubMed Central

    Martos-Moreno, G.A.; Sackmann-Sala, L.; Berryman, D.E.; Blome, D.W.; Argente, J.; Kopchick, y J.J.

    2015-01-01

    Introducción El tejido adiposo blanco (TAB) subcutáneo (Sc) humano podría variar dependiendo de su localización anatómica, con diferencias en su perfil proteómico. Pacientes y métodos Se obtuvieron aspirados de TAB-Sc de seis mujeres con IMC >25 kg/m2, sometidas a liposucción. Dicho TAB-Sc se obtuvo de seis localizaciones anatómicas: abdominal superior e inferior, muslo, dorsal, flanco y cadera, analizándose su perfil proteómico mediante electroforesis bidimensional. En muslo y abdomen superior se compararon, además, las muestras obtenidas de las dos capas del TAB-Sc (profunda y superficial). Resultados Se detectaron 21 proteínas que mostraban una intensidad de expresión diferente entre las seis localizaciones anatómicas y 14 entre las capas superficial y profunda de una misma región. Entre las proteínas identificadas se incluyen: vimentina (proteína estructural); proteínas “heat-shock” (HSPs), superóxido-dismutasa, (estrés/chaperoninas); proteína fijadora de ácidos grasos 4 (FABP-4) y alfa-enolasa (metabolismo lipídico y de los hidratos de carbono, respectivamente) y ATP-sintetasa (producción de energía). Entre las regiones estudiadas, el TAB-Sc dorsal mostraba un perfil proteómico particular, con menor expresión de proteínas implicadas en la producción de energía y metabolismo (ATP-sintetasa, alfa-enolasa, HSPs y FABP-4) que el resto de regiones. Conclusiones Los niveles de expresión de diversas proteínas en el TAB-Sc humano no son homogéneos, difiriendo entre localizaciones anatómicas. Esto sugiere la existencia de diferencias funcionales en el TAB-Sc de acuerdo con su localización anatómica, lo que debe considerarse antes de asumir la extrapolación de los datos derivados del TAB-Sc de una determinada localización al de otras partes de la anatomía. PMID:23228439

  13. PubMed

    De Battista, Juan Carlos; Buonanotte, Carlos Federico; Foa Torres, Gustavo A; Keller, Jeffrey Thomas; Aranega, Cesar I

    2018-04-24

    Antecedentes: Las enfermedades que afectan la órbita representan un desafío quirúrgico, en particular las que comprometen el ápex orbitario. Una vía óptima de acceso quirúrgico proporciona la mejor exposición permitiendo identificar ciertas estructuras anatómicas claves llamadas reparos anatómicos. Objetivo: Describir la anatomía endoscópica de la unidad estructural Fisura Orbitaria Inferior / Músculo de Müller a nivel del ápex orbitario generando así un nuevo reparo anatómico endoscópico. Material y método: Análisis descriptivo óseo de la fisura orbitaria inferior (FOI) en cráneos secos, disección y estudio bajo técnica endoscópica de 6 cabezas fijadas en formol y coloreadas; finalmente se tomaron distancias y ángulos a forámenes relacionados con el ápex orbitario a 10 cráneos secos. El análisis estadístico se realizó con el programa estadístico SPSS 17,0 (SPSS, Inc., Chicago, IL). Resultado: En todas las disecciones endoscópicas se pudo identificar la unidad fisura orbitaria inferior-músculo de Müller y también verificar su íntima relación con el ápex orbitario. Morfométricamente el foramen óptico y el foramen redondo mayor están a una distancia promedio de 65.19mm y 60.16mm respectivamente. Los ángulos promedio del FO fue de 13.32 grados y del FRM de19.31 grados. Hallamos correlación significativa entre CO. y el FRM sólo en el hemicráneo izquierdo, (Tau b de Kendall 0.69, P=0.006). No se encontraron diferencias anatómicas (o morfológicas) significativas entre lados. Conclusión: bajo técnica endoscópica la unidad Fisura Orbitaria Inferior-Músculo de Müller (FOI-MM) es un reparo anatómico constante, útil y seguro que permite el reconocimiento del ápex orbitario y sus áreas contiguas.

  14. Mapa Geologico de Venezuela a Escala 1:750,000

    USGS Publications Warehouse

    Hackley, Paul C.; Urbani, Franco; Karlsen, Alex W.; Garrity, Christopher P.

    2006-01-01

    Se presenta un mapa geologico digital de Venezuela sobre un fondo de relieve sombreado. Los datos geologicos e hidrologicos del norte del rio Orinoco proceden de la digitalizacion de mapas geologicos en papel a escala 1:500.000. Estos datos fueron integrados con el mapa geologico digital del Escudo de Guayana Venezolano, a su vez derivado de hojas en papel a escala 1:500.000. La informacion sobre los tipos de fallas mostrados en el mapa es igual que en las fuentes originales. Los poligonos geologicos fueron atribuidos por edad, litologia y nombre de la unidad siguiendo el Codigo geologico de Venezuela. Se incorporaron revisiones significativas de la geologia de la Cordillera de la Costa a partir de las nuevas hojas integradas a escala 1:25.000. Toda esta informacion geologico-estructural se sobrepuso a una imagen de relieve sombreado, producida por el procesamiento de los datos de radar interferometrico con 90 m (3 arcosegundos) de resolucion espacial obtenidos por la mision topografica de radar del transbordador espacial (SRTM). Las areas de la base de datos del SRTM carentes de informacion fueron llenadas por medio de la interpolacion de los datos de las celdas adyacentes. Para producir la imagen de relieve sombreado se uso una direccion de iluminacion de 315 deg con un angulo de 65 deg sobre el horizonte. La proyeccion usada en el mapa es conica equidistante, con latitudes de 4 y 9 deg norte como paralelos estandar y una longitud de 66 deg al oeste como meridiano central. Los datos en el mapa proceden primordialment de hojas a escala 1:500.000 y el producto esta preparado para una impresion optima en escala 1:750.000. Los usuarios pueden obtener ampliaciones mayores, sin embargo no se garantiza la precision del mapa a escalas mas detalladas. Especialmente en la region de Guayana, al sobreponer los mapas geologicos sobre la reciente imagen SRTM, se notan grandes discrepancias no sistematicas tanto en contactos como en fallas. Esto es debido a que los mapas

  15. Understanding ozone mechanisms to alleviate ceramic membrane fouling

    NASA Astrophysics Data System (ADS)

    Chu, Irma Giovanna Llamosas

    before the onset of a cake. These facts put in evidence the important role of electrical charges in filtration processes with ceramic membranes (Chiu, 2011; S. Lee & Kim, 2014; Szymczyk, Fievet, Reggiani, & Pagetti, 1998b). In the ozonation side, it was confirmed that natural waters with high NOM content (>3 mg/L) trigger advanced oxidation processes (Acero & Von Gunten, 2001). It was also found that condition pH 6.5 showed higher NOM decomposition than condition pH 8.5 at the highest ozone dose used.

  16. Estudio de reflectancia enfocado a la cartografia litologica de rocas igneas, efectos de distintos tipos de metamorfismo y analisis estructural en materiales precambricos, basado en datos espectrales de laboratorio e imagenes thematic mapper (Macizo Hesperico Central, Prov. de Caceres y Badajoz)

    NASA Astrophysics Data System (ADS)

    Plaza Garcia, Maria Asuncion

    The rampant success of quantum theory is the result of applications of the 'new' quantum mechanics of Schrodinger and Heisenberg (1926-7), the Feynman-Schwinger-Tomonaga Quantum Electro-dynamics (1946-51), the electro-weak theory of Salaam, Weinberg, and Glashow (1967-9), and Quantum Chromodynamics (1973-); in fact, this success of 'the' quantum theory has depended on a continuous stream of brilliant and quite disparate mathematical formulations. In this carefully concealed ferment there lie plenty of unresolved difficulties, simply because in churning out fabulously accurate calculational tools there has been no sensible explanation of all that is going on. It is even argued that such an understanding is nothing to do with physics. A long-standing and famous illustration of this is the paradoxical thought-experiment of Einstein, Podolsky and Rosen (1935). Fundamental to all quantum theories, and also their paradoxes, is the location of sub-microscopic objects; or, rather, that the specification of such a location is fraught with mathematical inconsistency. This project encompasses a detailed, critical survey of the tangled history of Position within quantum theories. The first step is to show that, contrary to appearances, canonical quantum mechanics has only a vague notion of locality. After analysing a number of previous attempts at a 'relativistic quantum mechanics', two lines of thought are considered in detail. The first is the work of Wan and students, which is shown to be no real improvement on the iisu.al 'nonrelativistic' theory. The second is based on an idea of Dirac's - using backwards-in-time light-cones as the hypersurface in space-time. There remain considerable difficulties in the way of producing a consistent scheme here. To keep things nicely stirred up, the author then proposes his own approach - an adaptation of Feynman's QED propagators. This new approach is distinguished from Feynman's since the propagator or Green's function is not obtained by Feynman's rule. The type of equation solved is also different: instead of an initial-value problem, a solution that obeys a time-symmetric causality criterion is found for an inhomogeneous partial differential equation with homogeneous boundary conditions. To make the consideration of locality more precise, some results of Fourier transform theory are presented in a form that is directly applicable. Somewhat away from the main thrust of the thesis, there is also an attempt to explain, the manner in which quantum effects disappear as the number of particles increases in such things as experimental realisations of the EPR and de Broglie thought experiments.

  17. Reproductive aspects and knowledge of family planning among women with Acquired Immunodeficiency Syndrome.

    PubMed

    Lima, Ivana Cristina Vieira de; Cunha, Maria da Conceição Dos Santos Oliveira; Cunha, Gilmara Holanda da; Galvão, Marli Teresinha Gimeniz

    2017-05-25

    filhos, enquanto a laqueadura tubária foi maior em mulheres que não receberam orientações sobre planejamento familiar. A maioria das mulheres com Aids não pretendem mais ter filhos. O conhecimento sobre o planejamento familiar foi limitado por falta de orientações pelos profissionais de saúde. Analizar aspectos reproductivos y el conocimiento acerca de planificación familiar de las mujeres con síndrome de inmunodeficiencia adquirida (SIDA). Estudio transversal, descriptivo realizado de enero a diciembre de 2015, en la sala de enfermedades infecciosas de un hospital de Fortaleza, Ceará. Los datos fueron recolectados a través de una entrevista semiestructurada de forma de cuestionario en un ámbito privado. El estudio incluyó a 102 mujeres. La mayoría de ellos tenían conocimiento de ser seropositivas para el virus de la inmunodeficiencia humana (VIH) durante la atención prenatal (96,1%), y que no tenía intención de tener más hijos (63,7%). Mujeres menores de 39 años, con educación superior y terapia antirretroviral más corta eran más propensas a tener hijos (p=0,05). Mujeres con edades de menos de 39 años y más educación tenían más probabilidades de tener la información correcta acerca de tener hijos en presencia del VIH (p=0,05). Tener pareja estable aumentó la posibilidad de desear tener hijos, mientras que la ligadura de trompas fue mayor en las mujeres que no han recibido orientación sobre la planificación familiar. La mayoría de las mujeres con SIDA no tienen intención de tener hijos. El conocimiento acerca de la planificación familiar se vio limitada por la falta de orientación por los profesionales de la salud.

  18. PubMed

    Gómez, Luis Alberto; Montoya, Gladis; Rivera, Hernán Mauricio; Hernández, Juan Carlos

    2017-04-01

    Introducción. El virus del Zika (ZIKV) es un flavivirus con envoltura, transmitido a los seres humanos principalmente por el vector Aedes aegypti. La infección por ZIKV se ha asociado con un gran neurotropismo y con efectos neuropáticos, como el síndrome de Guillain-Barré en el adulto y la microcefalia fetal y posnatal, así como con un síndrome de infección congénita similar al producido por el virus de la rubéola (RV).Objetivo. Comparar las estructuras moleculares de la proteína de envoltura E del virus del Zika (E-ZIKV) y de la E1 del virus de la rubéola (E1-RV), y plantear posibles implicaciones en el neurotropismo y en las alteraciones del sistema nervioso asociadas con el ZIKV.Materiales y métodos. La secuencia de aminoácidos de la proteína E-ZIKV (PDB: 5iZ7) se alineó con la de la glucopreteína E1 del virus de la rubéola (PDB: 4ADG). Los elementos de la estructura secundaria se determinaron usando los programas Vector NTI Advance®, DSSP y POSA, así como herramientas de gestión de datos (AlignX®). Uno de los criterios principales de comparación y alineación fue la asignación de residuos estructuralmente equivalentes, con más de 70 % de identidad.Resultados. La organización estructural de la proteína E-ZIKV (PDB: 5iZ7) fue similar a la de E1-RV (PDB: 4ADG) (70 a 80 % de identidad), y se observó una correspondencia con la estructura definida para las glucoproteínas de fusión de membrana de clase II de los virus con envoltura. E-ZIKV y E1-RV exhibieron elementos estructurales de fusión muy conservados en la región distal del dominio II, asociados con la unión a los receptores celulares de entrada del virus de la rubéola (glucoproteína de mielina del oligodendrocito, Myelin Oligodendrocyte Glycoprotein, MOG), y con los receptores celulares Axl del ZIKV y de otros flavivirus.Conclusión. La comparación de las proteínas E-ZIKV y E1-RV es un paso necesario hacia la definición de otros factores moleculares determinantes del

  19. Validation of the Earthquake Archaeological Effects methodology by studying the San Clemente cemetery damages generated during the Lorca earthquake of 2011

    NASA Astrophysics Data System (ADS)

    Martín-González, Fidel; Martín-Velazquez, Silvia; Rodrigez-Pascua, Miguel Angel; Pérez-López, Raul; Silva, Pablo

    2014-05-01

    and we have been able to constrain the ranges of orientation for each EAE's. The orientation of the damage is not usually recorded after an earthquake; however, it can provide information on seismic source in historical earthquakes. References Giner-Robles, J. L., Perez-Lopez, R., Silva Barroso, P., Rodriguez-Pascua, M. A., Martin-Gonzalez, F. and Cabanas, L. 2012. Analisis estructural de danos orientados en el terremoto de Lorca del 11 de mayo de 2011. Aplicaciones en arqueosismologia. Boletín Geológico y Minero, 123 (4): 503-513 Rodriguez-Pascua, M.A., Perez-Lopez, R., Silva, P.G., Giner- Robles, J.L., Garduno-Monroy, V.H. and Reicherter, K. 2011. A Comprehensive Classification of Earthquake Archaeological Effects (EAE) for Archaeoseismology. Quaternary International, 242, 20-30.

  20. Seismic hazard assessment in the Catania and Siracusa urban areas (Italy) through different approaches

    NASA Astrophysics Data System (ADS)

    Panzera, Francesco; Lombardo, Giuseppe; Rigano, Rosaria

    2010-05-01

    , through the site approach, for Catania area can be interpreted in terms of greater damage historically observed at this town and its smaller distance from the seismogenic structures. On the other hand, the higher level of hazard found for Siracusa, throughout the Esteva-Cornell approach, could be a consequence of the features of such method which spreads out the intensities over a wide area. However, in SHA the use of a combined approach is recommended for a mutual validation of obtained results and any choice between the two approaches is strictly linked to the knowledge of the local seismotectonic features. References Albarello D. and Mucciarelli M.; 2002: Seismic hazard estimates using ill?defined macroseismic data at site. Pure Appl. Geophys., 159, 1289?1304. Cornell C.A.; 1968: Engineering seismic risk analysis. Bull. Seism. Soc. Am., 58(5), 1583-1606. D'Amico V. and Albarello D.; 2007: Codice per il calcolo della pericolosità sismica da dati di sito (freeware). Progetto DPC-INGV S1, http://esse1.mi.ingv.it/d12.html Esteva L.; 1967: Criterios para la construcción de espectros para diseño sísmico. Proceedings of XII Jornadas Sudamericanas de Ingeniería Estructural y III Simposio Panamericano de Estructuras, Caracas, 1967. Published later in Boletín del Instituto de Materiales y Modelos Estructurales, Universidad Central de Venezuela, No. 19. Ordaz M., Aguilar A. and Arboleda J.; 2007: CRISIS2007, Program for computing seismic hazard. Version 5.4, Mexico City: UNAM. SSHAC (Senior Seismic Hazard Analysis Committee); 1997: Recommendations for probabilistic seismic hazard analysis: guidance on uncertainty and use of experts. NUREG/CR-6372.

  1. Prioritization of strategies to approach the judicialization of health in Latin America and the Caribbean.

    PubMed

    Pinzón-Flórez, Carlos Eduardo; Chapman, Evelina; Cubillos, Leonardo; Reveiz, Ludovic

    2016-09-01

    To describe strategies that contribute to the comprehensive approach to the judicialization of health in countries of Latin America and the Caribbean. A search was structured to identify articles presenting strategies to approach the judicialization of health. A survey was designed, which included actors of the health system and judiciary sector. We prioritized the strategies qualified by more than the 50.0% of the participants as "very relevant". Strategies were categorized according to: governance, provision of services, human resources, information systems, financing, and medical products. We included 64 studies, which identified 50 strategies, related to the sub-functions and components of health systems. Of the 165 people who answered the survey, 80.0% were aged 35-64 years. The distribution of men and women was homogeneous. Half of the respondents were from Colombia (20.0%), Uruguay (16.9%), and Argentina (12.7%). We prioritized strategies that addressed aspects of generation of useful scientific evidence for decision making according to the health needs of the population, empowerment for the society, and creating spaces for discussion of measures of inclusion or exclusion of health technologies. The executive and judiciary decision makers prioritized questions that dealt with strategies that would ensure accountability. The results of this study contribute to the identification of effective strategies to approach the phenomenon of judicialization of health, guaranteeing the right to health. Describir estrategias que contribuyan al abordaje integral de la judicialización de la salud en países de América Latina y El Caribe. Se estructuró una búsqueda para identificar artículos que presentaran estrategias para el abordaje de la judicialización en salud. Se diseñó una encuesta, en donde se incluyeron actores del sistema de salud y del sector judicial. Se priorizaron las estrategias calificadas por más del 50,0% de los participantes como "muy relevantes

  2. Groundwater targeting in a hard-rock terrain using fracture-pattern modeling, Niva River basin, Andhra Pradesh, India

    NASA Astrophysics Data System (ADS)

    Srinivasa Rao, Y.; Reddy, T. V. K.; Nayudu, P. T.

    2000-09-01

    'eau souterraine. Dans la région étudiée, les fractures N35°-55°E ont été identifiées comme étant en extension, et les fractures N35°-55°W comme étant à la fois en extension et en cisaillement. Ces fractures sont apparemment les fractures ouvertes les plus jeunes. Partout où la densité des fractures N35°-55°E et N35°-55°W est élevée, la zone altérée est plus épaisse, les fluctuations de la nappe sont faibles et les rendements des puits sont forts. Des zones à potentiel en eau souterraine ont ainsi été délimitées et classées en excellent, bon à très bon, assez bon et médiocre. Resumen. Las zonas de fracturación y de meteorización son las que condicionan el flujo de agua subterránea en rocas duras, debido a la falta de porosidad primaria en la matriz rocosa. Se utilizaron cinco conjuntos de datos fotográficos del satélite Landsat con el fin de preparar un mapa integrado hidrogeomorfológico de la cuenca del río Niva, al sur del estado Andhra Pradesh (India). El objetivo era estudiar el potencial de aguas subterráneas en esta región, que es propensa a períodos de sequía, en la que predominan las rocas duras. Se aplicó el modelo de deformación integrado de Larsson a la identificación de los sistemas de fracturación. El propósito era, por un lado, identificar los conjuntos de fracturas de tracción más jóvenes, que desempeñan un papel principal como reservorios de aguas subterráneas. Por otro lado, se quería comprender la importancia de la densidad de fracturación en el desarrollo de las aguas subterráneas. Se identificó una familia de fracturas de tracción con orientación N35°-55°E y otra familia N35°-55°W que contenía tanto bandas de cizalla como fracturas de tracción. Aparentemente, se trataba de las fracturas abiertas más recientes. El espesor de la zona de meteorización es grande cuando la densidad de fracturas de estas dos familias es elevada, hecho que está asociado a fluctuaciones pequeñas del nivel freático y

  3. Fertility rates and perinatal outcomes of adolescent pregnancies: a retrospective population-based study.

    PubMed

    Souza, Maria de Lourdes de; Lynn, Fiona Ann; Johnston, Linda; Tavares, Eduardo Cardoso Teixeira; Brüggemann, Odaléa Maria; Botelho, Lúcio José

    2017-04-06

    es entre 15 e 19 anos eram mais propensas a ter filhos prematuros (OR:1,1; IC:1,08-1,13; p<0,001), ter um filho com baixo peso ao nascer (OR:1,1; IC:1,10-1,15; p<0,001) , com baixo e Apgar no quinto minuto (OR:1,4; IC:1,34-1,45; p<0,001), do que mães com 20 anos ou mais; as chances de desfechos adversos também eram maiores entre mães de 10 a 14 anos. este estudo apresenta evidência de que as taxas de fertilidade entre adolescentes continuam altas em regiões que enfrentam privação social e econômica. Adolescentes e seus filhos são mais propensos a desfechos perinatais adversos. Enfermeiros(as), profissionais de saúde pública, profissionais de saúde e de assistência social, assim como educadores precisam trabalhar em conjunto para direcionar estratégias às adolescentes com maior risco, para ajudar a melhorar as taxas de fertilidade e dos desfechos. analizar tendencias en las tasas de fertilidad y asociaciones con resultados perinatales para adolescentes en el Estado de Santa Catarina, Brasil. estudio poblacional, considerando el período de 2006 a 2013. Para evaluar las asociaciones entre los resultados perinatales y los grupos de edad fueron aplicados los odds ratios y pruebas de ji-cuadrado. fueron observadas diferencias en la tasa de fertilidad entre las adolescentes de acuerdo con las regiones y períodos, variando de 40,9 a 72,0 por 1.000 en madres entre 15 y 19 años de edad. Las adolescentes tuvieron menos consultas prenatales en comparación con madres ≥20 años, con una mayor proporción sin pareja. La probabilidad de parto prematuro (OR:1,1; IC:1,08-1,13; p<0,001), bebé con peso bajo al nacer (OR:1,1; IC:1,10-1,15; p<0,001) y puntuación de Apgar baja a los 5 minutes (OR:1,4; IC:1,34-1,45; p<0,001) fue superior para madres entre 15 y 19 años en comparación con madres ≥20 años, con mayores chances de resultados negativos para aquellas entre 10 y 14 años de edad. este estudio evidencia que las tasas de fertilidad entre las adolescentes siguen

  4. List of Participants

    NASA Astrophysics Data System (ADS)

    2011-08-01

    GonzalezBUAP, FCFM Lorenzo Díaz CruzBUAP Facultad de Ciencias Físico Matemáticas Luis Rey Díaz BarrónDivisión de Ciencias e Ingenierías Luis UrenaUniversidad de Guanajuato Magda LolaDept. of Physics, University of Patras, Greece Mahmoud WahbaEgyptian Center for Theoretical Physics, MTI Marcus S CohenNew Mexico State University Mario A Acero OrtegaICN - UNAM Mario E GomezUniversidad de Huelva Mark PipeUniversity of Sheffield Mauro NapsucialeDCI-UG Mirco CannoniUniversidad de Huelva Mónica Felipa Ramírez PalaciosUniversidad de Guadalajara Murli Manohar VermaLucknow university, India Nassim BozorgniaUCLA Octavio Obregón Octavio ValenzuelaIA-UNAM Oleg KamaevUniversity of Minnesota Osamu SetoHokkai-Gakuen University Pedro F González DíazIFF, CSIC, Serrano 121, 28006 Madrid, Spain Qaisar ShafiBartol Research Inst. and Delaware U. Raul Hennings-YeomansLos Alamos National Laboratory René Ángeles MartínezDepartamento de Fisica, del DCI de la Universidad de Guanajuato Reyna XoxocotziBUAP, FCFM Rishi Kumar TiwariGovt. Model Science College, Rewa (MP) INDIA Roberto A SussmanICN-UNAM Selim Gómez ÁvilaDCI-UG Sugai KenichiSaitama University Susana Valdez AlvaradoDCI-UG TVladimir - 2K CollaborationColorado State University Tonatiuh MatosCINVESTAV Valeriy DvoeglazovUniversidad de Zacatecas Vannia Gonzalez MaciasDCI-UG Vladimir Avila-ReeseInstituto de Astronomia, UNAM Wolfgang BietenholzINC, UNAM (Mexico) Yamanaka MasatoKyoto Sangyo University Yann MambriniLPT Orsay Yu-Feng ZhouInstitute of Theotretical Physics, Chinese Academy of Sciences, PR China Aaron HigueraDCI-UG Azarael Yebra PérezDCI-UG César Hernández AguayoDCI-UG Jaime Chagoya AlvarezDCI-UG Jonathan Rashid Rosique CampuzanoDCI-UG José Alfredo Soto ÁlvarezDCI-UG Juan Carlos De Haro SantosDCI-UG Luis Eduardo Medina MedranoDCI-UG Maria Fatima Rubio EspinozaDCI-UG Paulo Alberto Rodriguez HerreraDCI-UG Roberto Oziel Gutierrez CotaDCI-UG Rocha Moran Maria PaulinaDCI-UG Xareni Sanchez MonroyDCI-UG

  5. Management changes resulting from hospital accreditation.

    PubMed

    Oliveira, João Lucas Campos de; Gabriel, Carmen Silvia; Fertonani, Hosanna Pattrig; Matsuda, Laura Misue

    2017-03-02

    contenido, modalidad temática, a la luz del referencial de la Evaluación en Salud de Avedis Donabedian. fue aprendida una gran categoría temática (family), llamada "Cambios Gerenciales Resultantes de la Acreditación: perspectivas de gestores y trabajadores" y cinco subcategorías (codes), relacionadas a los cambios gerenciales en las esferas operacional; estructural; financiera y de costo; en la alta gestión hospitalaria; y en la gestión de calidad. los cambios gerenciales en las organizaciones hospitalarias, resultantes de la Acreditación, fueron amplias, polifacéticas y coherentes con las mejoras en la calidad de los servicios. analisar as percepções de gestores e trabalhadores sobre as mudanças no gerenciamento hospitalar advindas da Acreditação. estudo descritivo com abordagem qualitativa. Participaram cinco gestores da qualidade hospitalar e outros 91 trabalhadores das mais diversas categorias profissionais, níveis hierárquicos e áreas de atuação de quatro hospitais do sul do Brasil certificados pela Acreditação nacional de diferentes níveis, que responderam à questão "Fale-me sobre o gerenciamento deste hospital, antes e depois da Acreditação". Os dados foram gravados, transcritos na íntegra e transportados para acesso e manejo no software ATLAS.ti, versão 7.1. Após isso, procedeu-se a análise de conteúdo, modalidade temática, sustentada à luz do referencial da Avaliação em Saúde de Avedis Donabedian. apreendeu-se uma grande categoria temática (family), denominada "Mudanças Gerenciais Advindas da Acreditação: perspectivas de gestores e trabalhadores" e cinco subcategorias (codes), relacionadas às mudanças gerenciais no âmbito operacional; estrutural; financeiro e de custo; na alta gestão hospitalar; e na gestão da qualidade. as mudanças gerenciais nas organizações hospitalares, advindas da Acreditação, se mostraram amplas, multifacetadas e coadunam às melhorais da qualidade nos serviços.

  6. Estudio de la influencia de la refrigeracion con aire de forma natural e inducida en el comportamiento de instalaciones fotovoltaicas

    NASA Astrophysics Data System (ADS)

    Mazon Hernandez, Rocio

    panels are analysed to compare and select the best configuration. The presented research provides a deep knowledge of how they work as well as information and results for an improvement in future designs of building integrated photovoltaic systems. Este estudio se centra en analizar la influencia negativa de la temperatura en la produccion electrica de paneles fotovoltaicos al estar emplazados sobre cubierta de acero, como sucede en naves industriales y sobre un invernadero. Se estudian diferentes configuraciones que permitan refrigerar los paneles, reduciendo su temperatura y mejorar su rendimiento. Para abordar este problema, se han construido dos instalaciones experimentales, fieles a plantas solares en funcionamiento. Una instalacion engloba dos paneles fotovoltaicos sobre estructura fija al suelo. Uno de los paneles esta integrado sobre una superficie paralela y metalica. Entre ambas superficies existe un espacio que posibilita circular aire, permitiendo refrigerar el panel por conveccion natural, o conveccion forzada impulsando el aire con un ventilador. El otro panel, libre por su cara posterior y se ha considerado de referencia. Se ha estudiado el comportamiento del panel integrado sobre cubierta para diferentes secciones de aire y velocidades inducidas, comparandolo con el panel de referencia. Se ha desarrollado un modelo experimental que nos permite determinar la temperatura del panel en funcion de las variables que influyen en su refrigeracion. Adicionalmente, se han analizado los datos de una planta solar en funcionamiento, con paneles de igual caracteristicas, obteniendo correlaciones entre la temperatura del panel y las variables electricas y comparandolos con las obtenidas en la instalacion experimental. La segunda instalacion experimental reproduce parte de una instalacion solar sobre un invernadero, formada por cuatro paneles fotovoltaicos colocados sobre el plastico del invernadero, existiendo un canal divergente entre ambas superficies. Se estudia la

  7. Self-image and perception of mother and father in psychotic and borderline patients.

    PubMed

    Armelius, K; Granberg

    2000-02-01

    eine mangelnde Separation von ihren Müttern und eine geringe Differenzierung zwischen Autonomie und Kontrolle. Es wird außerdem diskutiert, wie die Ergebnisse auf die realen Beziehungen der Patienten zu anderen Menschen Einflus nehmen könnten. Des patients psychotiques et Borderline ont évalué leur image d'eux-mêmes et leur perception de leur mère et père à l'aide du modèle de l'Analyse Structural du Comportement Social (SASB. Les patients Borderline avaient des imagess plus négatives d'eux-mêmes et de leurs parents, surtout de leur père, que les patients psychotiques et les sujets normaux, alors que les patients psychotiques se jugeaient à peine différemment des sujets normaux. L'image de soi était en relation avec les images des deux parents pour les patients Borderline et pour les sujets normaux, alors que pour les patients psychotiques, seulement l'image de la mère jouait un rôle pour leur image. En plus, les patients psychotiques ne différenciaient pas entre les pôles de contrôle et d'autonomie dans l'image de soi introjectée. Nous en avons conclu que les patients Borderline se caractérisent par un attachement négatif, et les patients psychotiques par une faible séparation de la mère ainsi qu'une différenciation modeste entre autonomie et contrôle. L'influence de ceci sur les relations des patients avec les autrs est discutée dans cet article. Pacientes limítrofes y psicóticos evaluaron su autoimagen y la percepción que tenían de sus padres usando el modelo de Análisis estructural del comportamiento social (SASB). Los pacientes limítrofes registraron imágenes más negativas de sí mismos y de sus progenitores, especialmente de su padre, que los pacientes psicóticos y los normales, mientras que las evaluaciones de los pacientes psicóticos no difirieron mucho de las de los sujetos normales. La autoimagen tuvo relación con la imagen de ambos progenitores tanto en el caso de los pacientes limítrofes como de los sujetos normales

  8. Hydrogeology in North America: past and future

    NASA Astrophysics Data System (ADS)

    Narasimhan, T. N.

    2005-03-01

    'hydrogéologie est à la transition entre la volonté de découvrir de nouvelles ressources et l' exploitation la plus bénéfique au possible, et un management judicieux des ressources finies, interconnectées, qui sont vitales pour l' approvisionnement des hommes et autres formes de vie. Le futur de l' hydrogéologie sera dicté par la balance subtile dans laquelle intervient les cycles de l'hydrologie, de l'érosion, de la nutrition, et la décision d'une société technologique qui s'adapterait aux contraintes de la balance, ou qui continuerait d'exploiter les systèmes hydrologiques pour un bénéfice maximum. Par ailleurs il y a une nette tendance à inclure les aspects écologiques, les aspects environnementaux, et les changements humains qui pourraient être influencés par les modifications hydrogéologiques observées depuis une dizaine d'années. Este articulo es una retrospectiva sobre la evolución de la hidrogeología en Norte América en los pasados dos siglos, y una breve especulación de su futuro. La historia de la hidrogeología está marcada por desarrollos en muchos campos diferentes tal como hidrología de aguas subterráneas, mecánica de suelos, ciencia del suelo, geología económica, ingeniería del petróleo, geología estructural, geoquímica, geofísica, geología marina, y más recientemente, ecología. El campo se ha enriquecido por las contribuciones de investigadores distinguidos en todos esos campos. Actualmente, la hidrogeología se encuentra en transición de un estado de descubrir nuevos recursos y explotarlos eficientemente para un beneficio máximo, a un estado de gestión juiciosa de recursos finitos, interconectados, que son vitales para el sustento de humanos y otras cosas vivientes. El futuro de la hidrogeología posiblemente esté determinado por el balance sutil con el cual funcionan los ciclos nutricionales, erosionales e hidrológicos, y la decisión de una sociedad tecnológica para ya sea adaptarse a las restricciones impuestas por el

  9. The influence of faults in basin-fill deposits on land subsidence, Las Vegas Valley, Nevada, USA

    NASA Astrophysics Data System (ADS)

    Burbey, Thomas

    2002-07-01

    -dimensional consolidation. Jour. Applied Physics 12:155-164), a été utilisé pour évaluer la nature du déplacement au voisinage de deux failles verticales. La faille a été simulée comme 1) une barrière de faible perméabilité pour l'écoulement horizontal, 2) une rupture structurale dans le milieu, mais sans obstruction de l'écoulement, et 3) une combinaison des deux précédentes conditions. Les résultats indiquent que la barrière de faible perméabilité favorise fortement le déplacement horizontal. Le plan de faille constitue aussi un lieu de subsidence différentielle verticale significative. Les fortes contraintes calculées au voisinage de la faille laissent penser qu'il existe un fort potentiel de rupture et le développement de fissures du sol quand on suppose que la faille possède une faible perméabilité. Les résultats utilisant une combinaison des deux conditions suggèrent que le développement potentiel de fissures peut être grand sur ou à proximité du plan de faille et que la déformation horizontale joue vraisemblablement un rôle clé dans ce développement. Resumen. Se conoce la contribución que la deformación horizontal causada por el bombeo de sistemas acuíferos confinados tienen en el desarrollo de fisuras en regiones semiáridas, como es el caso del Valle de Las Vegas (Nevada, Estados Unidos de América). A pesar de la estabilización de los niveles, se continúa desarrollando nuevas fisuras, mientras las ya existentes se alargan y ensanchan cerca de las fallas de relleno de cuenca. Se ha utilizado un modelo tridimensional de desplazamiento granular basado en la teoría de consolidación de Biot (Biot, M.A., 1941. General theory of three-dimensional consolidation. J. Applied Physics, 12: 155-164) para evaluar la naturaleza del desplazamiento junto a dos fallas verticales. Se ha simulado cada falla como (1) una barrera de baja permeabilidad al flujo horizontal, (2) un hueco o ruptura estructural en el medio pero sin obstrucción al flujo de aguas

  10. Occurrence of springs in massifs of crystalline rocks, northern Portugal

    NASA Astrophysics Data System (ADS)

    Pacheco, Fernando António Leal; Alencoão, Ana Maria Pires

    2002-02-01

    ógicos, así como las desviaciones relacionadas con diferencias en la estructura de la roca y, presumiblemente, en las historias de deformación. Se profundizó en la relación entre la frecuencia de los manantiales y las estructuras de la roca por medio de la Determinación Espectral, que es un modelo introducido en el presente estudio. Los datos de entrada son las frecuencias de los manantiales y la longitud de las fracturas en cada dominio geológico, además de los ángulos entre las direcciones de las fracturas y la orientación actual del campo de tensiones. Los resultados del modelo incluyen las denominadas densidades intrínsecas, parámetro que cuantifica la existencia de manantiales en función de factores como el tipo de fractura y el régimen y edad de deformación asociados. Las densidades mayores (12,2 manantiales por kilómetro de lineamiento) fueron atribuidas a fracturas jóvenes de cizalla causadas por deformación frágil, y las menores (valor 0,1) con fracturas antiguas y dúctiles. La Determinación Espectral también relaciona cada clase de orientación con un parámetro estructural dominante: donde la existencia de fracturas está dominada por el campo actual de tensiones, la clase es paralela a la orientación presente de dicho campo; donde domina la longitud de las fracturas, sigue la dirección de las fallas normales de gran escala que atraviesan la región.