Science.gov

Sample records for algunos medios auxiliares

  1. Cúmulos abiertos y su medio interestelar

    NASA Astrophysics Data System (ADS)

    Rizzo, J. R.; Arnal, E. M.; Morras, R.; Cappa, C.

    Se analiza la distribución del hidrógeno neutro en la vecindad de cuatro cúmulos abiertos ubicados en el cuarto cuadrante galáctico, con el fin de investigar su posible interacción con el medio interestelar circundante. El estudio se lleva a cabo en base a observaciones de la línea de 21 cm del HI obtenidos con la antena de 30 m del IAR.

  2. Estudio multifrecuencia del medio interestelar cercano a HD 192281

    NASA Astrophysics Data System (ADS)

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

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

  3. Estudio multifrecuencia del medio interestelar cercano a HD 192281

    NASA Astrophysics Data System (ADS)

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

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

  4. Los plaguicidas y la contaminacion del medio ambiente Venezolano

    USGS Publications Warehouse

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

    1972-01-01

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

  5. Kaon properties in dense nuclear matter: are there experimental evidences of in medio effects?

    SciTech Connect

    Mangiarotti, A.

    2009-06-03

    Beyond the general interest for nuclear matter theory, the K{sup -} in medio mass modification could have important astrophysical consequences. Experimental evidences of how a nuclear medium affects K{sup +} and K{sup -} properties will be summarised. To reach a firm conclusion about the K{sup -}, the missing information on the flow will be shown to be still relevant.

  6. The influence of a medio-lateral unstable sole on invertor and evertor activation while descending stairs

    PubMed Central

    Yang, Ki-sik; Park, Kyungyeon; Choi, Bo-ram

    2016-01-01

    [Purpose] This study examined the effects of a medio-lateral unstable sole on invertor and evertor activation while descending stairs. [Subjects and Methods] The subjects were 30 university students with no history of ankle sprain. They descended stairs while wearing the medio-lateral unstable sole or with bare feet. Electromyography was used to record the activity of the tibialis anterior and peroneus longus and brevis muscles and paired t-tests were used to assess statistical significance. [Results] The medio-lateral unstable sole group showed increased tibialis anterior and peroneus longus and brevis muscle activation compared to the barefoot group. [Conclusion] Medio-lateral unstable sole can be used with exercises to prevent further ankle damage by activating both the inversion and eversion muscles.

  7. Moléculas orgánicas obtenidas en simulaciones experimentales del medio interestelar.

    NASA Astrophysics Data System (ADS)

    Muñoz-Caro, Guillermo Manuel

    Las nubes moleculares son regiones de formación de estrellas, con temperaturas cinéticas entre 10-50 K y densidades de 103-106 átomos cm-3. Su materia está formada por gas y polvo interestelar. Estas partículas de polvo están cubiertas por una fina capa de hielo, de unos 0.01 μm, que contiene H2O y a menudo CO, CO2, CH3OH y NH3. El hielo es presumiblemente irradiado por fotones ultravioleta y rayos cósmicos en las zonas poco profundas de las nubes moleculares y las regiones circunestelares. En un sistema de vacío, P ˜ 10-7 mbar, simulamos la deposición de hielo a partir de 10 K y la irradiación ultravioleta por medio de una lámpara de descarga de hidrógeno activada con microondas. La evolución del hielo se observa por medio de un espectrómetro infrarrojo. De este modo es posible determinar la composición del hielo observado en el medio interestelar y predecir la presencia de moléculas aún no detectadas en el espacio, que han sido producto del procesamiento del hielo en nuestros experimentos. También es posible calentar el sistema hasta temperatura ambiente para sublimar el hielo depositado. Cuando el hielo ha sido previamente irradiado, se observa un residuo compuesto por moléculas orgánicas complejas, algunas prebióticas, como varios ácidos carboxílicos, aminas, amidas, ésteres y en menor proporción moléculas heterocíclicas y aminoácidos. Algunas de estas moléculas podrían detectarse en estado gaseoso por medio de observaciones milimétricas y de radio. También podrían estar presentes en el polvo cometario, cuyo análisis químico está planeado por las misiones Stardust y Rosetta. Mientras tanto, nuestro grupo está llevando a cabo el análisis de partículas de polvo interplanetario (IDPs), algunas de las cuales pueden ser de origen cometario. Al igual que ocurre con los productos obtenidos por irradiación del hielo en nuestros experimentos, algunas IDPs son ricas en material orgánico que contiene oxígeno.

  8. Role of Medio-Dorsal Frontal and Posterior Parietal Neurons during Auditory Detection Performance in Rats

    PubMed Central

    Bohon, Kaitlin S.; Wiest, Michael C.

    2014-01-01

    To further characterize the role of frontal and parietal cortices in rat cognition, we recorded action potentials simultaneously from multiple sites in the medio-dorsal frontal cortex and posterior parietal cortex of rats while they performed a two-choice auditory detection task. We quantified neural correlates of task performance, including response movements, perception of a target tone, and the differentiation between stimuli with distinct features (different pitches or durations). A minority of units—15% in frontal cortex, 23% in parietal cortex—significantly distinguished hit trials (successful detections, response movement to the right) from correct rejection trials (correct leftward response to the absence of the target tone). Estimating the contribution of movement-related activity to these responses suggested that more than half of these units were likely signaling correct perception of the auditory target, rather than merely movement direction. In addition, we found a smaller and mostly not overlapping population of units that differentiated stimuli based on task-irrelevant details. The detection-related spiking responses we observed suggest that correlates of perception in the rat are sparsely represented among neurons in the rat's frontal-parietal network, without being concentrated preferentially in frontal or parietal areas. PMID:25479194

  9. Final Report (OO-ERD-056) MEDIOS: Modeling Earth Deformation Using Interferometric Observations from Space

    SciTech Connect

    Vincent, P; Walter, B; Zucca, J; Larsen, S; Goldstein, P; Foxall, W; Ryerson, F

    2002-01-29

    This final report summarizes the accomplishments of the 2-year LDRD-ER project ''MEDIOS: Modeling Earth Deformation using Interferometric Observations from Space'' (00-ERD-056) which began in FY00 and ended in FY01. The structure of this report consists of this summary part plus two separate journal papers, each having their own UCRL number, which document in more detail the major results in two (of three) major categories of this study. The two categories and their corresponding paper titles are (1) Seismic Hazard Mitigation (''Aseismic Creep Events along the Southern San Andreas Fault System''), and (2) Ground-based Nuclear Explosion Monitoring, or GNEM (''New Signatures of Underground Nuclear Tests Revealed by Satellite Radar Interferometry''). The third category is Energy Exploitation Applications and does not have a separate journal article associated with it but is described briefly. The purpose of this project was to develop a capability within the Geophysics and Global Security Division to process and analyze InSAR data for the purposes of constructing more accurate ground deformation source models relevant to Hazards, Energy, and NAI applications. Once this was accomplished, an inversion tool was to be created that could be applied to many different types (sources) of surface deformation so that accurate source parameters could be determined for a variety of subsurface processes of interest to customers of the GGS Division. This new capability was desired to help attract new project funding for the division.

  10. A modern analog of past climatic impacts on denudation rates and sediment transport: The Del Medio fan, NW Argentina

    NASA Astrophysics Data System (ADS)

    Savi, S.; Schildgen, T. F.; Tofelde, S.; Wittmann, H.; Strecker, M. R.

    2014-12-01

    The combined effects of tectonic and climatic forcing govern the evolution of landscapes, modifying erosional processes, changing river profiles, and ultimately impacting depositional systems. The complexity of the response, however, often means that we cannot predict a priori how a given landscape will react to climatic changes. The Del Medio catchment is located in the Humahuaca Basin, an intermontane valley of the Eastern Cordillera. This area coincides with a climatic divide between a sub-humid and a semi-arid environment. An extensive debris-flow fan sourced in the Del Medio catchment covers ca. 18.6 km2 of the lower basin. To investigate rates and timing of its evolution, we analyzed cosmogenic 10Be concentrations on large boulders from the fan surface, river sands and pebbles in 3 active channels, a depth profile, and bedrock exposed atop the drainage basin margins. Our CRN results illustrate the rapid rate at which the fan surface is subject to change, with each of the 16 analyzed boulder samples providing ages of < 400 years. The 15-m deep depth profile exposes three cycles of activity in the recent past. In addition, river sands record very high denudation rates (from several mm/yr to tens of mm/yr), despite bedrock denudation rates of < 0.04 mm/yr from most bedrock ridges. Interestingly, modern pebbles from tributaries with recent landslide activity consistently yield denudation rates that are faster than those from sands, while tributaries without landslide activity show the opposite pattern, documenting the importance of grain-size dependency for inferring the main mechanism of sediment transport within a catchment. Farther upstream in the more arid Humahuaca Basin, abandoned fluvial terrace sequences have been linked to wetter episodes during the late Quaternary. Within those fills, preliminary paleo-denudation rates reach values similar to those currently observed in the Del Medio catchment, while modern denudation rates from river sands are similar

  11. Basal and thirst-evoked vasopressin secretion in rats with electrolytic lesion of the medio-ventral septal area.

    PubMed

    Iovino, M; Poenaru, S; Annunziato, L

    1983-01-01

    Electrolytic lesion of the medio-ventral septal (MVS) area produces, 3 days after the surgery, a remarkable increase of daily diuresis and water intake in the rat. This polyuria and polydipsia is associated with decreased levels of circulating radioimmunoassayable vasopressin. In addition, if these lesioned animals were water-deprived (48 h), the usual vasopressin release observed in sham-lesioned and normal controls was markedly blunted. These results suggest that the MVS area exerts a modulatory control on vasopressin secretion both in basal and thirst-evoked conditions. PMID:24010174

  12. Medio-lateral stability of sit-to-walk performance in older individuals with and without fear of falling.

    PubMed

    Aberg, Anna Cristina; Frykberg, Gunilla Elmgren; Halvorsen, Kjartan

    2010-04-01

    Most falls in older people are due to loss of balance during everyday locomotion, e.g., when initiating walking from sitting; sit-to-walk (STW). It has been considered that the broader stride width in walking that is seen in many people with fear of falling (FoF) does not increase stability, but could be predictive of future falls because of increased medio-lateral (ML) velocity of the body centre of mass (CoM). This study was aimed to examine step-, velocity- and stability-related parameters, focusing on ML stability, in STW performance of people with and without FoF. Ten subjects with FoF and 10 matched controls, aged > or = 70 years, were included. Kinematic and kinetic data were collected in a laboratory. Stability parameters were calculated from a formula implying that the vertical projection of the CoM extrapolated by adding its velocity times a factor radicall/g (height of inverted pendulum divided by gravity) should fall within the base of support (BoS). A related spatial margin of stability (SMoS), defined as the minimum distance from the extrapolated CoM (XCoM) to the boundaries of the BoS, was also calculated. In the phase 'seat-off-second-toe-off', the FoF group had significantly (p<0.05) shorter and broader steps, lower forward but similar ML CoM velocity, and broader CoM and XCoM widths. The FoF group therefore exhibited a disproportionately large sideways velocity compared to the controls. This indicates that STW may be a hazardous transfer for older people with FoF, which should be relevant in assessment and training aimed at preventing falls. PMID:20189390

  13. A modern analog of past climatic impacts on sedimentary processes and landscape evolution in an intermontane basin: The Del Medio fan, NW Argentina

    NASA Astrophysics Data System (ADS)

    Savi, Sara; Schildgen, Taylor F.; Tofelde, Stefanie; Wittmann, Hella; Strecker, Manfred

    2014-05-01

    The combined effects of tectonic and climatic forcing govern the evolution of landscapes, setting the scale of topographic relief and the pace of landscape changes over time. Tectonic uplift or changes in precipitation regimes can fundamentally modify erosional processes and sediment flux from hillslopes, change river profiles, and ultimately impact depositional systems downstream. The complexity of the response, however, often means that we cannot predict a priori how a given landscape will react to future changes in climate, or how it responded in the past to multiple episodes of climate change. The Del Medio catchment is located in the southern part of the Humahuaca Basin, an intermontane valley within the Eastern Cordillera in transition to the Puna Plateau. This area coincides with a climatic and vegetation divide between a sub-humid environment downstream and the semi-arid upper Humahuaca Basin. An extensive fan sourced in the Del Medio catchment covers ca. 18.6 km2 of the basin outlet. The fan stratigraphy and surface morphology suggest that the fan dynamics are dominated by debris-flow processes. The surface comprises abandoned channels, levees and lobes, while exposed sections in channel cuts reveal unsorted, matrix-dominated deposits, with individual boulders reaching a diameter of 5 m. To investigate rates and timing of the Del Medio fan evolution, we analyzed cosmogenic 10Be concentrations on the surfaces of large boulders from the fan surface, river sands in active channels, a depth profile, and bedrock exposed atop the drainage basin margins. Our preliminary CRN results illustrate the rapid rate at which the active fan surface is subject to change, with each of the 11 analyzed boulder samples providing ages of < 200 years. In addition, river sands record very high denudation rates that range from several mm/yr to tens of mm/yr, despite bedrock denudation rates from the basin margins of only 0.04 mm/yr. These contrasting denudation rates likely result

  14. Impact of posterior tibial nail malpositioning on iatrogenic injuries by distal medio-lateral interlocking screws. A cadaveric study on plastinated specimens.

    PubMed

    Wegmann, Kilian; Burkhart, Klaus Josef; Buhl, Jörg; Gausepohl, Thomas; Koebke, Jürgen; Müller, Lars Peter

    2012-12-01

    In intramedullary tibial nailing, multi-planar locking makes stabilization of proximal and distal metaphyseal fractures possible. A known complication in intramedullary nailing of the tibia is iatrogenic injury to neuro-vascular structures caused by the insertion of locking screws. As shown in previous studies, the distal positioning of the nail is important, as it determines the course of the locking bolts. The goal of the present study was to display the consequences of posterior nail malpositioning with respect to the safety of the distal medio-lateral locking screws and the available options. Human cadaveric legs were plastinated according to the sequential plastination technique after intramedullary nailing of the tibia and were then cut transversely. The tibial nails were placed centrally or posteriorly. Macroscopic analysis showed a distinct drawback of posterior nail positioning, with diminished options for the placement of the locking screws and thereby a risk of damaging the anterior and posterior neuro-vascular bundles by distal medio-lateral locking screws. PMID:23409576

  15. Algunos Animales de Latino America = Some Animals of Latin America.

    ERIC Educational Resources Information Center

    Thompson, Kathryn F. B.

    Developed by the Latin American Culture Studies Project for educators of elementary level children, these materials are designed to teach students the Spanish and English names of animals found in Latin America. The lesson includes coloring sheets, duplicating masters, fact sheets, the card game Maymayguashi, and directions for preparation. (DB)

  16. El medio interestelar alrededor de estrellas Of

    NASA Astrophysics Data System (ADS)

    Caballero, N.; Cappa, C.

    Se analiza la distribución del hidrógeno neutro interestelar en la vecindad de algunas estrellas Of con el fin de investigar la presencia de burbujas de H I vinculadas a las estrellas. Se determinan los parámetros físicos de las burbujas de H I encontradas y se comparan con estructuras similares vinculadas a estrellas Wolf-Rayet. El estudio se lleva a cabo en base a datos pertenecientes al relevamiento de Weaver y Willians (1973).

  17. El medio interestelar alrededor de estrellas Of: HD 108

    NASA Astrophysics Data System (ADS)

    Cappa, C.; Testori, J. C.

    Hemos analizado la distribución del hidrógeno neutro interestelar en la vecindad de la estrella Of HD 108 en base a perfiles de la línea de 21 cm. Estos datos nos han permitido encontrar una probable burbuja interestelar asociada a la estrella. Comparamos estos resultados con la emisión en otros rangos espectrales y estimamos los principales parámetros físicos de la estructura.

  18. Espectros en el infrarrojo medio de discos de escombros

    NASA Astrophysics Data System (ADS)

    Garcia, L.; Gómez, M. N.

    In this contribution we report mid-infrared spectra of 3 stars (ages 10 -- 10 yrs) with known debris disks. These spectra are compared with the absorption profiles of crystalline and amorphous silicates. The presence of absorption bands can be explained by considering the existence of amorphous compounds together with those of the crystalline type. In addition; dust particles may have typical sizes 1.5 m. This would indicate that the material in the debris disks is in a more advanced evolutionary state than in disks around T - Tauri stars ( years) or in the interstellar medium; populated by dust particles with sizes 0.1 m consisting of amorphous silicates. FULL TEXT IN SPANISH

  19. Curso: Auxiliar de Farmacia. Guia. Farmacia Teorica: Manual del Estudiante. Matematica General: Manual del Estudiante. Documento de Trabajo (Pharmacy Assistant Course Guide. Theoretical Pharmacy Student Manual. General Mathematics Student Manual. Working Document).

    ERIC Educational Resources Information Center

    Puerto Rico State Dept. of Education, Hato Rey. Area for Vocational and Technical Education.

    The three parts of this document are intended for a 3-semester course for pharmacy assistants. The course guide contains the following sections: occupational description; educational philosophy; general objectives; tasks/competencies for each unit; course organization; brief description of the topics; student standards; and evaluation methods.…

  20. Ensenando El Espanol por Medio de Accion (Teaching Spanish through Action).

    ERIC Educational Resources Information Center

    Segal, Bertha

    A teaching guide containing 102 elementary to intermediate level Spanish lessons is presented. The lessons are based on the Total Physical Response technique of second language teaching. They follow the stages of first language acquisition: listening, speaking, and reading. Each of the ten units contains a list of new vocabulary words, individual…

  1. Seminario latinoamericano de didactica de los medios audiovisuales (Latin American Seminar on Teaching with Audiovisual Aids).

    ERIC Educational Resources Information Center

    Eduplan Informa, 1971

    1971-01-01

    This seminar on the use of audiovisual aids reached several conclusions on the need for and the use of such aids in Latin America. The need for educational innovation in the face of a new society, a new type of communication, and a new vision of man is stressed. A new definition of teaching and learning as a fundamental process of communication is…

  2. World bank and the environment. Progress report. Banco mundial y el medio ambiente

    SciTech Connect

    Not Available

    1991-01-01

    The second annual report describes specific environmental strategies and environmental lending in the Bank's four operational regions: Africa; Asia; Europe, Middle East, and North Africa; and Latin America and the Caribbean. It details the Bank's progress in eight environmental categories: energy and the environment, pollution, urban environment, water resources management, forest and land management, social and cultural, environmental economics, and the global environment. One chapter is devoted exclusively to tropical forests, studying ways in which the Bank is dealing with deforestation as a part of the constant review of its forest policies. Suggestions are made for decreasing the degradation of tropical forests while meeting demands for forest products. This chapter reflects a shift in Bank emphasis from commercial ventures to conservation measures. The publication reports on other initiatives by the Bank during fiscal 1991, including the launching of the Global Environment Facility (GEF)--a pilot program to oversee reduction of global warming, preservation of biological diversity, protection of international waters, and prevention of ozone depletion.

  3. Amazonian Triatomine Biodiversity and the Transmission of Chagas Disease in French Guiana: In Medio Stat Sanitas.

    PubMed

    Péneau, Julie; Nguyen, Anne; Flores-Ferrer, Alheli; Blanchet, Denis; Gourbière, Sébastien

    2016-02-01

    The effects of biodiversity on the transmission of infectious diseases now stand as a cornerstone of many public health policies. The upper Amazonia and Guyana shield are hot-spots of biodiversity that offer genuine opportunities to explore the relationship between the risk of transmission of Chagas disease and the diversity of its triatomine vectors. Over 730 triatomines were light-trapped in four geomorphological landscapes shaping French-Guiana, and we determined their taxonomic status and infection by Trypanosoma cruzi. We used a model selection approach to unravel the spatial and temporal variations in species abundance, diversity and infection. The vector community in French-Guiana is typically made of one key species (Panstrongylus geniculatus) that is more abundant than three secondary species combined (Rhodnius pictipes, Panstrongylus lignarius and Eratyrus mucronatus), and four other species that complete the assemblage. Although the overall abundance of adult triatomines does not vary across French-Guiana, their diversity increases along a coastal-inland gradient. These variations unravelled a non-monotonic relationship between vector biodiversity and the risk of transmission of Chagas disease, so that intermediate biodiversity levels are associated with the lowest risks. We also observed biannual variations in triatomine abundance, representing the first report of a biannual pattern in the risk of Chagas disease transmission. Those variations were highly and negatively correlated with the average monthly rainfall. We discuss the implications of these patterns for the transmission of T. cruzi by assemblages of triatomine species, and for the dual challenge of controlling Amazonian vector communities that are made of both highly diverse and mostly intrusive species. PMID:26867025

  4. Estandares: El medio ambiente de las politicas (Standards: The Policy Environment). ERIC Digest.

    ERIC Educational Resources Information Center

    Hadderman, Margaret

    This digest in Spanish offers a snapshot of the standards movement: its origins, the definitions of standards and which ones matter, its successes at the district and state levels, the backlash against the movement, and possible policy directions. While a broad coalition of constituencies has embraced standards-based reform as a means of improving…

  5. Amazonian Triatomine Biodiversity and the Transmission of Chagas Disease in French Guiana: In Medio Stat Sanitas

    PubMed Central

    Flores-Ferrer, Alheli; Blanchet, Denis; Gourbière, Sébastien

    2016-01-01

    The effects of biodiversity on the transmission of infectious diseases now stand as a cornerstone of many public health policies. The upper Amazonia and Guyana shield are hot-spots of biodiversity that offer genuine opportunities to explore the relationship between the risk of transmission of Chagas disease and the diversity of its triatomine vectors. Over 730 triatomines were light-trapped in four geomorphological landscapes shaping French-Guiana, and we determined their taxonomic status and infection by Trypanosoma cruzi. We used a model selection approach to unravel the spatial and temporal variations in species abundance, diversity and infection. The vector community in French-Guiana is typically made of one key species (Panstrongylus geniculatus) that is more abundant than three secondary species combined (Rhodnius pictipes, Panstrongylus lignarius and Eratyrus mucronatus), and four other species that complete the assemblage. Although the overall abundance of adult triatomines does not vary across French-Guiana, their diversity increases along a coastal-inland gradient. These variations unravelled a non-monotonic relationship between vector biodiversity and the risk of transmission of Chagas disease, so that intermediate biodiversity levels are associated with the lowest risks. We also observed biannual variations in triatomine abundance, representing the first report of a biannual pattern in the risk of Chagas disease transmission. Those variations were highly and negatively correlated with the average monthly rainfall. We discuss the implications of these patterns for the transmission of T. cruzi by assemblages of triatomine species, and for the dual challenge of controlling Amazonian vector communities that are made of both highly diverse and mostly intrusive species. PMID:26867025

  6. La Socializacion Linguistica en un Medio Bilingue (Linguistic Socialization within a Bilingual Context).

    ERIC Educational Resources Information Center

    Blanco, Amalio

    1980-01-01

    In order to arrive at a better theory of linguistic socialization, the study examined the relationship of the language of socialization, the content of the communication and the social reality in which socialization takes place by administering a questionnaire to 31 Mexican American mothers. (Author/SB)

  7. Vinculación entre varios cúmulos estelares y estructuras del medio interestelar

    NASA Astrophysics Data System (ADS)

    Corti, M. A.; Baume, G. L.; Panei, J. A.; Suad, L. A.; Testori, J. C.; Borissova, J.; Kurtev, R.; Chené, A. N.; Ramirez Alegría, S.

    2015-08-01

    We study the embedded clusters DBS77, 78, 102, 160, and 161 located in the Galactic plane in the fourth quadrant of the Milky Way and the surrounding interstellar medium (ISM). We analyzed UBVIc photometry (SOAR) and infrared spectroscopy (NTT, ESO). We complemented these data with JHK (VVV2MASS), HI 21 cm bands (SGPS), 1.4 GHz (ATCA), and 4.85 GHz (PMN). We did multiband analysis and spectral classification of the brightest stars in each area. We also identified the ISM structures possibly related to the clusters. Finally, we obtained the main parameters of the studied clusters, the structures of the ISM and the link between them.

  8. [Radio-carpal and medio-carpal arthroscopy in instability of the wrist].

    PubMed

    Sennwald, G; Fischer, M; Jacob, H A

    1993-01-01

    Forty-one arthroscopies were performed on previously asymptomatic wrists following trauma. In about 25% of the wrists there was only one specific ligamentous lesion. In 75% however a combination of 2 or several distinct lesions was observed. These lesions, localised on the ulnar aspect of the mid-carpal joint, are more complex than those on the radio-carpal joint on the radial aspect of the carpus. These observations would tend to confirm our present day knowledge of wrist biomechanics but disagree with the currently proposed concepts of instability by several American authors. "Instability" seems to be inadequate to define complex lesions, more adequate would be the simple description of a "dysfunctional state" of the wrist complex. This statement must be related to the position of the carpal bones, which do not show any significant change despite the tears shown. The arthroscopy appears to range first in a series of diagnostic tools. However it concerns mainly the ligamentous layers facing the interior of the joint while lacking information about time elapsed since the actual trauma. We therefore state that arthroscopy may decrease but not exclude diagnostic failures. Type and risk of therapeutic decisions are also appreciated with increased accuracy. No doubt there still remain discrepancies when clinical, arthrographic and arthroscopic examination are compared, which indicates the complementary nature of the technics of investigation, especially in the light of the current state of the biomechanic sciences of the wrist. PMID:7683900

  9. Sh2-206: medio interestelar y formación estelar

    NASA Astrophysics Data System (ADS)

    Martín, M. C.; Cappa, C. E.

    The analysis of the interstellar matter around the HII region Sh2-206 shows extended emission in a region of more than 30 pc from the optical nebula detected both in the radio continuum and in the far IR. The distribution of dust, atomic and molecular gas, is compatible with the fact that the nebula is density bounded towards the east, and ionization bounded towards the south and west. This region is consistent with the champagne model. FULL TEXT IN SPANISH

  10. Un nuevo fármaco puede ser una opción de tratamiento para algunos cánceres de mama

    Cancer.gov

    Los resultados de un estudio clínico internacional permiten suponer que, en poco tiempo, habrá otra opción de tratamiento para las mujeres con cáncer de mama metastásico HER2 positivo que deja de responder a los tratamientos dirigidos con trastuzumab.

  11. Concepcion de la Educacion Basica en Algunos Paises. Series Divulgaciones No. 1 (The Notion of Basic Education in Several Countries. Information Series No. 1).

    ERIC Educational Resources Information Center

    Enriquez, Galo, Ed.

    This booklet defines and considers basic education and reports on the concept as it is implemented and developed in Argentina, Colombia, Chile, Spain, and Peru. Basic education, as defined here, generally refers to the education of children between the ages of 7 and 16 years. Initial remarks define the issue and discuss general principles. The…

  12. Algunos aspectos sicolinguisticos de la Instruccion Programada en el laboratorio de idiomas (Some Psycholinguistic Aspects of Programed Instruction in the Language Laboratory).

    ERIC Educational Resources Information Center

    Monteverde G., Luisa

    1971-01-01

    This paper presents ideas on using programed instruction in the language laboratory for second language learning. Linear programing is more suited to language instruction than is branching, because the former more easily allows comparison between the students' and teachers' solutions and is technically less complicated and less expensive to…

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

    NASA Astrophysics Data System (ADS)

    Saker, L.; Gómez, M.; Chavero C.

    2015-08-01

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

  14. Life Support Systems. Environment Booklet 1. Teacher's Edition=Sistemas vitales. Libro del medio ambiente 1. Manual para El Maestro.

    ERIC Educational Resources Information Center

    California State Univ., Los Angeles. National Dissemination and Assessment Center.

    The booklet is part of a grade 10-12 social studies series produced for bilingual education. The series consists of six major thematic modules, with four to five booklets in each. The interdisciplinary modules are based on major ideas and designed to help students understand some major human problems and make sound, responsive decisions to improve…

  15. Urban Ecosystems. Environment Booklet 4. Teacher's Edition =Ecosist urbanos. Libro del medio ambiente 4. Manual para El Maestro.

    ERIC Educational Resources Information Center

    California State Univ., Los Angeles. National Dissemination and Assessment Center.

    The booklet is part of a grade 10-12 social studies series produced for bilingual education. The series consists of six major thematic modules, with four to five booklets in each. The interdisciplinary modules are based on major ideas and are designed to help students understand some major human problems and make sound, responsive decisions to…

  16. Conservation, Pollution. Environment Booklet 3. Teacher's Edition=Conservacion, contaminacion. Libro del medio ambiente 3. Manual para El Maestro.

    ERIC Educational Resources Information Center

    California State Univ., Los Angeles. National Dissemination and Assessment Center.

    The booklet is part of a grade 10-12 social studies series produced for bilingual education. The series consists of six major thematic modules, with four to five booklets in each. The interdisciplinary modules are based on major ideas and designed to help students understand some major human problems and make sound, responsive decisions to improve…

  17. How the brain predicts people's behavior in relation to rules and desires. Evidence of a medio-prefrontal dissociation.

    PubMed

    Corradi-Dell'Acqua, Corrado; Turri, Francesco; Kaufmann, Laurence; Clément, Fabrice; Schwartz, Sophie

    2015-09-01

    Forming and updating impressions about others is critical in everyday life and engages portions of the dorsomedial prefrontal cortex (dMPFC), the posterior cingulate cortex (PCC) and the amygdala. Some of these activations are attributed to "mentalizing" functions necessary to represent people's mental states, such as beliefs or desires. Evolutionary psychology and developmental studies, however, suggest that interpersonal inferences can also be obtained through the aid of deontic heuristics, which dictate what must (or must not) be done in given circumstances. We used fMRI and asked 18 participants to predict whether unknown characters would follow their desires or obey external rules. Participants had no means, at the beginning, to make accurate predictions, but slowly learned (throughout the experiment) each character's behavioral profile. We isolated brain regions whose activity changed during the experiment, as a neural signature of impression updating: whereas dMPFC was progressively more involved in predicting characters' behavior in relation to their desires, the medial orbitofrontal cortex and the amygdala were progressively more recruited in predicting rule-based behavior. Our data provide evidence of a neural dissociation between deontic inference and theory-of-mind (ToM), and support a differentiation of orbital and dorsal prefrontal cortex in terms of low- and high-level social cognition. PMID:25820129

  18. Reconnaissance evaluation of Honduran geothermal sites. Una evaluacion por medio de reconocimiento de seis areas geotermicas en Honduras

    SciTech Connect

    Eppler, D.; Fakundiny, R.; Ritchie, A.

    1986-12-01

    Six geothermal spring sites were selected on the basis of preliminary investigations conducted in Honduras over the last decade and were evaluated in terms of their development potential. Of the six, the Platanares and San Ignacio sites have high base temperatures and high surface fluid discharge rates and appear to have the best potential for further development as sources of electrical power. A third site, Azacualpa, has a high enough base temperature and discharge rate to be considered as a back-up, but the logistical problems involved in geophysical surveys make it less attractive than the two primary sites. Of the remaining three sites, Pavana may be a source of direct-use heat for local agricultural processing. Sambo Creek and El Olivar have either severe logistical problems that would impede further investigation and development or base temperatures and flow rates that are too low to warrant detailed investigation at this time.

  19. The world bank and the environment, exercise 1992. Annual report. Banco mundial y el medio ambiente, ejercicio de 1992

    SciTech Connect

    Not Available

    1992-01-01

    The report describes the Bank's activities in assisting countries with environmental management, such as programs to reduce poverty without exhausting natural resources. Included are assessments of the environmental impacts of projects supported by World Bank loans, and accounts of efforts to meet global environmental challenges with coordinated international action through the Global Environment Facility (GEF). Among the events in the period covered by the report are the affirmation of the World Bank's participation with United Nations organizations in the GEF and the Bank's administration of pilot programs aimed at finding solutions to such global environmental problems as pollution of international waters, global warming, depletion of the Earth's ozone layer, and dwindling biological diversity; the United Nations Conference on Environment and Development; and the publication of the World Development Report 1992, with its theme of development and the environment.

  20. En otras palabras: Perfeccionamiento del espanol por medio de la traduccion (In Other Words: Perfecting Spanish Language Skills through Translation).

    ERIC Educational Resources Information Center

    Lunn, Patricia V.; Lunsford, Ernest J.

    This publication, written primarily in Spanish, is an activity book designed to teach Spanish through translation based on the theory that, in order to produce an acceptable translation, students must focus their attention on lexical and grammatical detail. The book combines incisive grammar explanations, relevant lexical information, and a wide…

  1. A role for PHANTASTICA in medio-lateral regulation of adaxial domain development on tomato and tobacco leaves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diverse leaf forms in nature can be categorized into two groups: simple and compound. A simple leaf has a single blade unit, whilst a compound leaf is dissected into leaflets. For both simple and compound leaves, a MYB domain transcription factor PHANTASTICA (PHAN) plays an important role in establi...

  2. Mecanismos cinéticos y distribuciones energéticas de iones (H3+, N2H+, CH3+...) en plasmas fríos de H2/N2/CH4

    NASA Astrophysics Data System (ADS)

    Tanarro, I.; Herrero, V. J.; Islyaikin, A.; Tabarés, F. L.; Tafalla, D.

    En este trabajo se presenta el estudio espectrométrico de los plasmas levemente ionizados generados en una descarga continua a baja presión de H2 con trazas de N2 y CH4, orientado principalmente a identificar la naturaleza y distribución energética de los iones que en ella se producen, y a asignar algunos de los mecanismos cinéticos elementales de formación y destrucción de tales especies. Alguno de los iones mayoritarios de estos plasmas, como el H3+, presenta gran interés desde el punto de vista de la Astrofísica por su prevista intervención en la química de las ionosferas planetarias y del medio interestelar, al actuar como sustancia intermedia en la formación de gran variedad de especies moleculares; si bien, dada su pequeña concentración, su observación real en el espacio se demoró hasta la pasada década de los años 90, cuando fue detectado por primera vez en la atmósfera de Júpiter y en otros objetos estelares. Del mismo modo que los trabajos espectroscópicos de laboratorio resultan indispensables para la posterior identificación de las especies observadas en el espacio, es de esperar que la asignación de los procesos cinéticos más importantes que tienen lugar en los plasmas generados en reactores de descarga, como los aquí presentados, permitan extrapolar los resultados así obtenidos al esclarecimiento de los mecanismos fisico-químicos participantes en otros medios observables únicamente a larga distancia.

  3. The Design and Development of Online Course Materials: Some Features and Recommendations (El diseño y desarrollo de materiales para cursos en línea: algunos rasgos y recomendaciones)

    ERIC Educational Resources Information Center

    Cuesta, Liliana

    2010-01-01

    This article discusses various features in the design and implementation of online course materials. The author provides a critical review of some instructional design patterns and expands on the alignment among instruction, motivation and learners' performances as part of a curriculum design process. In this context, the author emphasizes…

  4. Algunos Criterios para Evaluar Programas de Educacion Superior a Nivel de Posgrado: El Caso Particular de la Administracion Publica (Some Criteria to Evaluate Higher Education Programs at the Graduate Level: The Special Case of Public Administration).

    ERIC Educational Resources Information Center

    Valle, Victor M.

    Intended as a contribution to a workshop discussion on program evaluation in higher education, the paper covers five major evaluation issues. First, it deals with evaluation concepts, explaining the purposes of evaluation; pertinent terms; and the sources of evaluation in public health procedures, the scientific method, the systems approach, and…

  5. 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.

  6. Can medio-lateral baseplate position and load sharing induce asymptomatic local bone resorption of the proximal tibia? A finite element study

    PubMed Central

    Innocenti, Bernardo; Truyens, Evelyn; Labey, Luc; Wong, Pius; Victor, Jan; Bellemans, Johan

    2009-01-01

    Background Asymptomatic local bone resorption of the tibia under the baseplate can occasionally be observed after total knee arthroplasty (TKA). Its occurrence is not well documented, and so far no explanation is available. We report the incidence of this finding in our practice, and investigate whether it can be attributed to specific mechanical factors. Methods The postoperative radiographs of 500 consecutive TKA patients were analyzed to determine the occurrence of local medial bone resorption under the baseplate. Based on these cases, a 3D FE model was developed. Cemented and cementless technique, seven positions of the baseplate and eleven load sharing conditions were considered. The average VonMises stress was evaluated in the bone-baseplate interface, and the medial and lateral periprosthetic region. Results Sixteen cases with local bone resorption were identified. In each, bone loss became apparent at 3 months post-op and did not increase after one year. None of these cases were symptomatic and infection screening was negative for all. The FE analysis demonstrated an influence of baseplate positioning, and also of load sharing, on stresses. The average stress in the medial periprosthetic region showed a non linear decrease when the prosthetic baseplate was shifted laterally. Shifting the component medially increased the stress on the medial periprosthetic region, but did not significantly unload the lateral side. The presence of a cement layer decreases the stresses. Conclusion Local bone resorption of the proximal tibia can occur after TKA and might be attributed to a stress shielding effect. This FE study shows that the medial periprosthetic region of the tibia is more sensitive than the lateral region to mediolateral positioning of the baseplate. Medial cortical support of the tibial baseplate is important for normal stress transfer to the underlying bone. The absence of medial cortical support of the tibial baseplate may lead to local bone resorption at the proximal tibia, as a result of the stress shielding effect. The presence of a complete layer of cement can reduce stress shielding, though. Despite the fact that the local bone resorption is asymptomatic and non-progressive, surgeons should be aware of this phenomenon in their interpretation of follow-up radiographs. PMID:19615054

  7. Construccion/Communicacion y Medios Publicitarios. Libro del Profesor (Construction/Communication & Media. Teacher's Guide). B5. CHOICE (Challenging Options in Career Education).

    ERIC Educational Resources Information Center

    Mid-Hudson Migrant Education Center, New Paltz, NY.

    The guide, written in Spanish, comprises the fourth grade unit of a career education curriculum for migrant students. Focus of the unit is on the tools and tasks of workers in 11 jobs in the construction, communication, and media occupational clusters: heavy equipment operator, architect, mason, carpenter, plumber, electrician, telephone line…

  8. Limited Resources, Unlimited Wants. Environment Booklet 2. Teacher's Edition=Recursos limitados, deseos ilimitados. Libro del medio ambiente 2. Manual para El Maestro.

    ERIC Educational Resources Information Center

    California State Univ., Los Angeles. National Dissemination and Assessment Center.

    The booklet is part of a grade 10-12 social studies series produced for bilingual education. The series consists of six major thematic modules, with four to five booklets in each. The interdisciplinary modules are based on major ideas and are designed to help students understand some major human problems and make sound, responsive decisions to…

  9. Estudio estadístico de la actividad de formación estelar en galaxias interactuantes: dependencia con el medio

    NASA Astrophysics Data System (ADS)

    Alonso, M. S.; García Lambas, D.; Tissera, P.; Coldwell, G.

    We analyse the effects of galaxy interactions on star formation in groups and clusters of galaxies with virial masses in the range 1013 - 10 15 M⊙. We find a trend for galaxy-galaxy interactions to be less efficient in high density regions in comparison with galaxies with no close companion. However, the relative projected distance and relative radial velocity thresholds ,rp ˜ 25 h-1 kpc and Δ V ˜ 100 km s-1, to trigger significant star formation activity are nearly independent of environment. The above results reflect, on one hand, the local nature of star formation induced by tidal interactions and, on the other, the role play by the internal properties of galaxies. The similarity of the distribution of radius and velocity of the pairs normalised to the group virial radius and group mean velocity dispersion is similar to that of other typical group members. We find that galaxy pairs in rich groups are systematically redder and with a lower present-day star formation activity than other group members, suggesting a higher efficiency of galaxy-galaxy interactions in these dense regions in the past.

  10. Global environment facility: Independent evaluation of the pilot phase; Fondo para el medio ambiente mundial: evaluacion independiente de la etapa experimental

    SciTech Connect

    1994-06-01

    This study responds to a request by participants in the Global Environment Facility (GEF) for an independent evaluation of the pilot phase. It profiles the GEF, discusses its policy framework, and reviews project development procedures and the strategies and projects in each of the GEF`s four focal areas. The study concludes that fundamental changes must occur and recommends specific reforms, such as articulating more clearly the GEF`s mandate, objectives, and strategies; addressing deficiencies in meeting its global focus; improving capacities and procedures within implementing agencies for managing the portfolio; and increasing non-government organization (NGO), country and community-level participation.

  11. Comparative effects of split Orimulsion{reg_sign}, fuel oil {number_sign}6 and Lago Medio Crude oil over functional variables of an estuarine community

    SciTech Connect

    Quilici, A.; Rodriguez-Grau, J.; Vasquez, P.; Infante, C.; Schiazza, J. La; Briceno, H.; Pereira, N.

    1995-12-31

    This study evaluates the effects, on comparative bases, of three different kinds of hydrocarbon products, on physiological and dynamic parameters of a mangrove community (located East of Venezuela), by experimentally monitoring changes on those parameters using Laguncularia racemosa as a bioindicator mangrove species. Orimulsion{reg_sign} has been introduced recently in the World market; and it is, in essence, an emulsion produced from bitumen mixed with water and stabilized with a surfactant. Results indicate that litter disappearance rate, a parameter directly related to nutrient cycling and dynamics, is not altered by the split Orimulsion{reg_sign}, when compared to controls; while the other hydrocarbon products tested, seem to exert an impact over this parameter. In addition, Orimulsion{reg_sign}, is less retained in mangrove sediments compared with the other two products, as indicated by the remaining percent mean of total hydrocarbon soil content sampled on the same consecutive dates. Nonetheless, the photosynthetic capacity of leaves as well as soil respiratory rates, monitored at treatment and control plots, were not affected by any of the products tested. In conclusion, L. racemosa, in terms of its photosynthetic capacity, is not directly affected by any of the hydrocarbon products tested, nor does there seem to be an effect on soil respiration; however, Orimulsion{reg_sign}, in contrast to the other products, does not seem to be causing an impact with regard to litter dynamics.

  12. La influencia del medio interestelar sobre la evolución del remanente de supernova (RSN) G53.6-2.2

    NASA Astrophysics Data System (ADS)

    Giacani, E. B.; Dubner, G.; Cappa, C.; Testori, J. C.

    G53.6-2.2 is a supernova remnant with an unusual morphology: in the radio band the overall shape can be described as two shells that overlap on the NW side of the remnant. The X-ray emission fills the source and peaks in the region where the radio rings overlap; while in the optical range the emission consists of filaments that correlate with portions of radio rings that overlap in the NW. The aim of the present project is to investigate the neutral hydrogen distribution around the remnant in search for signatures that allow to disclose the role of the surrounding gas in conditioning the observed morphology.

  13. Our World, Our Future: Bilingual Activities on Population and the Environment = Nuestro Mundo, Nuestro Futuro: Actividades Bilingues Acerca de la Poblacion y el Medio Ambiente.

    ERIC Educational Resources Information Center

    Zero Population Growth, Inc., Washington, DC.

    This bilingual activity guide helps to develop students' understandings of the interdependence of people and the environment. Interdisciplinary resources are provided featuring environmental education lessons with applications to the social studies, science, math, and family life education curricula. It is designed for the middle school level, but…

  14. Experiencias Educativas en el Medio Rural Colombiano. Serie Divulgacion No. 2. [Educational Experiences in the Rural Colombian Milieu. Circulation Series No. 2].

    ERIC Educational Resources Information Center

    Ministerio de Educacion Nacional, Bogota (Colombia). Centro Nacional de Documentacion e Informacion Pedagogica.

    In fulfillment of the Colombian National Government's educational policy aimed toward improving the rural population's level of living, two fundamental projects have been implemented. These projects have led to the creation of schools, the continuous extension of grades, and the creation of "Concentraciones de Desarrollo Rural." They seek to: (1)…

  15. QUALITY ASSURANCE PERFORMANCE AUDIT REPORT FOR THE SECRETARIA DEL MEDIO AMBIENTE CIUDAD DE MEXICO, DF, MEXICO RED AUTOMATICA DE MONITOREO ATMOSFERICO (RAMA) AIR QUALITY MONITORING STATIONS

    EPA Science Inventory

    The United States Environmental Protection Agency (U.S. EPA) conducted this evaluation of the air monitoring network, known as RAM (Red Automatica de Monitoreo Atmosferico) at the request of the Mexico City Secretariat of the Environment on October 16-27, 2000. This evaluation...

  16. Astronomy at School: Measurements of the Earth-Moon Distance. (Spanish Title: Astronomía en la Escuela: Medición de la Distancia Tierra-Luna.) Astronomia na Escola: Medida da Distância Terra-Lua

    NASA Astrophysics Data System (ADS)

    Paolantonio, Santiago; Pintado, Olga I.

    2006-12-01

    The aim of this project is to approach High School students to Science. We propose to measure the Earth-Moon distance using the parallax. The observation and measurements techniques and all the calculations needed are described in this paper. The results obtained in a test experience realized during 2003 are presented. This test shows that this is a feasible project and also shows which things needed to be improved. Se plantea la propuesta de un proyecto educativo dirigido al Nivel Medio de enseñanza, consistente en la determinación de la distancia Tierra - Luna por paralaje. Se describen las técnicas de observación, mediciones y cálculos. Se proporcionan a continuación los resultados obtenidos en la experiencia piloto realizada en el 2003, la que permitió comprobar la factibilidad de llevar a cabo la propuesta, así como perfeccionar los diferentes aspectos involucrados en la misma. Propomos neste trabalho um projeto educativo dirigido ao Ensino Médio que consiste na determinação da distância Terra-Lua pelo efeito da paralaxe. As técnicas de observação, medidas e cálculos auxiliares são descritos, e os resultados obtidos numa experiência-teste realizada no ano de 2003 apresentados. Este último teste permitiu comprovar a viabilidade de execução da proposta e aperfeiçoar diversos aspectos da mesma.

  17. Evolución de planetas gigantes y posibilidades de su detección directa

    NASA Astrophysics Data System (ADS)

    Brunini, A.; Benvenuto, O. G.

    Desde la reciente detección de planetas gigantes orbitando estrellas cercanas de tipo solar por medio de efecto Doppler, uno de los principales problemas, en cuanto al estudio de los sistemas planetarios extrasolares, se refiere a la posibilidad de obtener evidencia directa de su existencia. Esto parece ser factible gracias a que en un futuro cercano entrarán en operación algunos telescopios especialmente adecuados a estos propósitos. Por tal motivo, hemos comenzado desde hace un tiempo un esfuerzo en cuanto al estudio de la evolución planetaria. A tales efectos hemos adaptado el código de evolución estelar de nuestro Observatorio al caso planetario. Las principales diferencias entre el caso estelar y el planetario se encuentran en la ecuación de estado. A tales fines hemos incluído la reciente ecuación de estado de Saumon, Chabrier y Van Horn, las opacidades radiativas de Guillot et al., procesos de quema de Deuterio, etc. También se ha considerado la posible existencia de fases de hielo y roca en el interior planetario. Por el momento hemos despreciado los efectos de la rotación planetaria. Con este código hemos computado la evolución de planetas con masas desde 10 hasta 0.3 masas de Júpiter. Utilizando nuestros resultados numéricos discutimos la detectabilidad de estos objetos en condiciones realistas.

  18. Environment Module. Test Booklet. Test Items for Booklets 1, 2, 3, 4=Libro de prueba. Modulo del medio ambiente. Itemes de prueba para los libros 1, 2, 3, 4.

    ERIC Educational Resources Information Center

    California State Univ., Los Angeles. National Dissemination and Assessment Center.

    The booklet is part of a grade 10-12 social studies series produced for bilingual education. The series consists of six major thematic modules, with four to five booklets in each. The interdisciplinary modules are based on major ideas and are designed to help students understand some major human problems and make sound, responsive decisions to…

  19. The Latinas' Guide to the Information Superhighway: A Bilingual Guide for Latinas by Latinas = Guia para Mujeres Latinas sobre la Supercarretera de la Informacion: Una Guia Bilingue para Latinas por medio de Latinas.

    ERIC Educational Resources Information Center

    MANA, A National Latina Organization, Washington, DC.

    This guide to the Internet is designed to give Latinas basic information on computers and the information superhighway. Written in both Spanish and English, the guide begins by defining the Internet and making some suggestions about acquiring access to a computer. Among the topics discussed are how to choose an Internet service provider, how to…

  20. Tabacundo: Battery-Powered Dialogue. Technical Note No. 10.

    ERIC Educational Resources Information Center

    Hoxeng, James; And Others

    The effects of using cassette-tape recordings for programming in a rural radio school program in Ecuador were examined. Radio schools broadcasted five afternoons a week and offered a primary school equivalency certificate at the completion of the course. Students were under the direction of an "Auxiliar" who followed the directions of the…

  1. The Framework of Media Education and Media Criticism in the Contemporary World: The Opinion of International Experts (Situación de la educación en medios y la competencia crítica en el mundo actual: opinión de expertos internacionales)

    ERIC Educational Resources Information Center

    Fedorov, Alexander; Livitskaya, Anastasia

    2015-01-01

    The article analyzes the results of the international survey "Synthesis of Media Literacy Education and Media Criticism in the Modern World," conducted by the authors in May-July 2014. 64 media educators, media critics, and researchers in the field of media education and media culture participated in the survey, representing 18…

  2. For a Child, Life is a Creative Adventure: Supporting Development and Learning through Art, Music, Movement, and Dialogue. A Guide for Parents and Professionals. = Para los ninos, la vida es una aventura creativa: Como estimular el desarrollo y el aprendizaje por medio de las artes visuales, la musica, el movimiento y el dialogo. Guia para padres de familia y profesionales.

    ERIC Educational Resources Information Center

    Cohen, Elena

    Recognizing that creativity facilitates children's learning and development, the Head Start Program Performance Standards require Head Start programs to include opportunities for creative self-expression. This guide with accompanying videotape, both in English- and Spanish- language versions, encourages and assists adults to support children's…

  3. Towards a Discourse for Criticism in Language Teaching: Analysis of Sociocultural Representations in Mass Media (Hacia un discurso para la crítica en la enseñanza de la lengua: análisis de representaciones socioculturales en medios de comunicación)

    ERIC Educational Resources Information Center

    Vargas Torres, Margarita Rosa

    2010-01-01

    This article states that in order to exercise citizenship with responsibility, language teachers need to popularize a discourse for criticism in which students and teachers transcend tacit knowledge and common sense due to meta-cognition and argumentation and reach systematic knowledge and procedures posed by experts in the different disciplines.…

  4. Poblacion estelar joven embebida en la nube molecular galactica asociada a la fuente IRAS 18236-1205

    NASA Astrophysics Data System (ADS)

    Romero, Ricardo Retes

    2008-06-01

    En esta tesis presento una metodología de seleccion y estudio de la población estelar embebida en la nube molecular galactica asociada a la fuente IRAS 18236-1205. La fuente IRAS posee colores de region Ultra Compacta HII (UCHII) y tiene deteccióon en monosulfuro de carbono (CS), trazador molecular de alta densidad, lo cual da la posibilidad de definir la nube molecular asociada hacia esta region. Lo anterior muestra que esta es buena candidata a región de formación estelar masiva. La metodología de seleccion de la población embebida, est à basada por una parte, en la distribución del gas molecular monoxido de carbono (13CO) asociado a la fuente IRAS, nube molecular seleccionada del mapeo Galactic Ring Survey (GRS) realizado en 13CO. Otros pasos de la seleccion, se basan en los diagramas color-color y color-magnitud con datos del cercano infrarrrojo de 2MASS. Para el estudio de la componente estelar se usaron los catalogos de fuentes puntuales en el cercano, medio y lejano infrarrojo de 2MASS, SPITZER e IRAS, respectivamente. De los diagramas color-color y color-magnitud, usando datos de 2MASS, se construyo un criterio fotométrico para identificar los objetos estelares j ovenes embebidos en la region molecular. Aplicando modelos a la distribución espectral de energía (SED) de algunos ellos, se encontraron parametros estelares de objetos estelares j ovenes embebidos de masa intermedia y alta. Adicionalmente, se encontro un objeto de masa ´ intermedia no identifiado por el catalogo de 2MASS y su efecto sobre el medio interestelar, emision en la banda de [4.5] μm de IRAC-Spitzer asociado a un outflow. Dos de los objetos seleccionados por el criterio fotometrico resultaron ser objetos estelares jovenes de alta e intermedia masa (B1V/B2V y B8V/A0V respectivamente), los cuales deben estar asociados a la emision radiativa responsable de los colores de región UC HII. Otro objeto estelar joven de baja masa (F0V/F5V) fue encontrado en la region de estudio

  5. Experimentos submarinos

    NASA Video Gallery

    NEEMO se lleva a cabo en un laboratorio submarino llamado Aquarius. De la mano del astronauta de la NASA José Hernández conoce alguno de los experimentos que los astronautas (o acuanautas) hacen mi...

  6. Ten Ways Hispanics and Latinos Can Prevent Type 2 Diabetes

    MedlinePlus

    ... los alimentos que come y en la actividad física que hace. Estos son algunos consejos que le ... de peso comiendo alimentos saludables y haciendo actividad física. Trate de bajar de peso haciendo por lo ...

  7. Breakfast of champions or kiss of death? Survival and sexual performance of protein-fed, sterile Mediterranean fruit flies (Diptera: Tephritidae)

    SciTech Connect

    Yuval, B.; Maor, M.; Levy, K.; Kaspi, R.; Taylor, P.; Shelly, T.

    2007-03-15

    The sterile insect technique (SIT) is increasingly being used around the world to control Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), the Mediterranean fruit fly as part of an area-wide integrated approach. One option that may improve the effectiveness of the SIT, by increasing the sexual competitiveness of released sterile males, consists of feeding males protein during the post-teneral stage, a diet that increases sexual performance of wild males. We examine the effects of diet on the successive hurdles males must overcome in order to inseminate females, i.e., joining leks, copulating females, having their sperm stored and inhibition of female remating. In addition, we address the effects of diet on post-release foraging success, longevity, and the ability to withstand starvation. While protein feeding universally increases the sexual success of wild males, its effect on sterile males varies with strain, experimental settings, and environmental conditions. In some cases, treatments that resulted in the best sexual performance were significantly associated with increased vulnerability to starvation. However, no particular diet affected the ability of sterile males to find nutrients in the field when these where available. We suggest it may be better to release relatively short-lived flies that are highly competitive, rather than long-lived, sexually ineffective ones. (author) [Spanish] El uso de la tecnica de insecto esteril (TIE) esta aumentando alrededor del mundo para el control de Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), la mosca mediterranea de la fruta como parte de un enfoque integrado por toda el area. Una opcion que puede mejorar la eficiencia de TIE, por medio del aumento de la capacidad de los machos esteriles liberados para competir, consiste en la alimentacion de los machos con proteina durante la etapa de pos-teneral, una dieta que aumenta el desempeno sexual de los machos naturales. Nosotros examinamos los efectos de la

  8. 16 CFR 455.5 - Spanish language sales.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... pueden darle a usted algunos derechos y hacer que el vendedor resuelva problemas graves que no fueron... implícitas” de acuerdo a la ley del estado pueden concederle derechos adicionales. EC29SE91.053 EC29SE91.054...

  9. Carne cocinada a altas temperaturas y el riesgo de cáncer

    Cancer.gov

    Hoja informativa que explica cómo algunos compuestos químicos se forman en la carne cocinada a alta temperatura y describe los resultados de estudios sobre el consumo de estos compuestos químicos y el riesgo de cáncer.

  10. Desigualdades por cáncer

    Cancer.gov

    Información básica de las desigualdades en salud por cáncer en EE. UU., factores que contribuyen a la carga desproporcionada del cáncer en algunos grupos y ejemplos de desigualdades en incidencia y mortalidad entre ciertos grupos de la población.

  11. Ciencia en la Estación Espacial Internacional

    NASA Video Gallery

    Durante más de 10 años, los seres humanos vivieron en la estación espacial las 24 horas, los siete días de la semana Y llevaron a cabo más de 600 experimentos. Fíjate apenas algunos de estos experi...

  12. Prediabetes: What You Need to Know

    MedlinePlus

    ... prediabetes si tiene sobrepeso y • no realiza actividad física • su madre, su padre o alguno/a de sus hermanos/as tiene diabetes • tiene presión arterial elevada o un nivel alto de colesterol (un tipo de grasa en ...

  13. Everybody's Different Nobody's Perfect

    MedlinePlus

    ... en Rush University Medical Center en Chicago. © 2009, Muscular Dystrophy Association Inc. (Asociación de la Distrofia Muscular) Everybody’s ... get stronger. These kids have a disease called MUSCULAR DYSTROPHY. Algunos niños tienen discapacidades porque sus músculos son ...

  14. Engineering chiral porous metal-organic frameworks for enantioselective adsorption and separation.

    PubMed

    Peng, Yongwu; Gong, Tengfei; Zhang, Kang; Lin, Xiaochao; Liu, Yan; Jiang, Jianwen; Cui, Yong

    2014-01-01

    The separation of racemic molecules is of substantial significance not only for basic science but also for technical applications, such as fine chemicals and drug development. Here we report two isostructural chiral metal-organic frameworks decorated with chiral dihydroxy or -methoxy auxiliares from enantiopure tetracarboxylate-bridging ligands of 1,1'-biphenol and a manganese carboxylate chain. The framework bearing dihydroxy groups functions as a solid-state host capable of adsorbing and separating mixtures of a range of chiral aromatic and aliphatic amines, with high enantioselectivity. The host material can be readily recycled and reused without any apparent loss of performance. The utility of the present adsorption separation is demonstrated in the large-scale resolution of racemic 1-phenylethylamine. Control experiments and molecular simulations suggest that the chiral recognition and separation are attributed to the different orientations and specific binding energies of the enantiomers in the microenvironment of the framework. PMID:25030529

  15. Engineering chiral porous metal-organic frameworks for enantioselective adsorption and separation

    NASA Astrophysics Data System (ADS)

    Peng, Yongwu; Gong, Tengfei; Zhang, Kang; Lin, Xiaochao; Liu, Yan; Jiang, Jianwen; Cui, Yong

    2014-07-01

    The separation of racemic molecules is of substantial significance not only for basic science but also for technical applications, such as fine chemicals and drug development. Here we report two isostructural chiral metal-organic frameworks decorated with chiral dihydroxy or -methoxy auxiliares from enantiopure tetracarboxylate-bridging ligands of 1,1‧-biphenol and a manganese carboxylate chain. The framework bearing dihydroxy groups functions as a solid-state host capable of adsorbing and separating mixtures of a range of chiral aromatic and aliphatic amines, with high enantioselectivity. The host material can be readily recycled and reused without any apparent loss of performance. The utility of the present adsorption separation is demonstrated in the large-scale resolution of racemic 1-phenylethylamine. Control experiments and molecular simulations suggest that the chiral recognition and separation are attributed to the different orientations and specific binding energies of the enantiomers in the microenvironment of the framework.

  16. Utilization of LANDSAT orbital imagery in the soil survey processes at Rio Grande do Norte state

    NASA Technical Reports Server (NTRS)

    Formaggio, A. R. (Principal Investigator)

    1984-01-01

    Pedologic photointerpretative criteria adapted to LANDSAT orbital imagery were used: drainage (pattern, integration degree, density and uniformity degree); relief (pattern, dissection degree and crest lines); photographic texture, photographic tonnality, and the land use (type, glebas size and intensity of use). The performance of the imagery as an auxiliar tool in the soil survey processes, at Rio Grande do Norte State was evaluated. The drainage and relief elements were easily extracted from the imagery and also ones that provided the greatest deductive possibility about pedologic boundaries. Other analyzed criteria were considered only auxiliaries, corroborating some soil limits in the evidences convergence phase. The principal pedologic dominions of the 30,000 sq km are covered by the same LANDSAT image (WRS 359/16) were delimited with good precision: (1) fluvial plains, beaches, dunes and coastal mangroves; (2) North Coast line Plateau; (3) Acu Sandstone Zone; (4) residual plateaus of the Tertiary; and (6) plains of the embasement.

  17. Hydrogeology of a fractured shale (Opalinus Clay): Implications for deep geological disposal of radioactive wastes

    NASA Astrophysics Data System (ADS)

    Gautschi, Andreas

    2001-01-01

    ême lorsque des fractures et des failles existaient dans certains des intervalles d'essais. Ces mesures sont conformes aux données hydrogéologiques tirées du recoupement des argiles à Opalinus par dix tunnels du Jura plissé du nord de la Suisse. Malgré une tectonique intense, peu de manifestations de faibles venues d'eau ont été rencontrées dans plus de 6600 m de tunnel. Toutes les venues d'eau se sont produites dans des sections de tunnel où le recouvrement est inférieur à 200 m. Les données hydrauliques sont en bon accord avec les données hydrochimiques et isotopiques de l'eau porale des argiles. En se basant sur le grand nombre de données hydrogéologiques, qui portent en partie sur les environnements géologiques particulièrement peu propices, on peut avancer que le transport advectif le long des failles et des fractures n'est pas un facteur susceptible de remettre en question le choix de l'argile à Opalinus comme roche hôte pour le stockage de déchets radioactifs en formation géologique profonde. Resúmen. Dentro del programa suizo de eliminación de residuos radiactivos de alta actividad, se está investigando la posibilidad de utilizar unos esquistos Jurásicos (Arcilla Opalina) como depósito geológico. Las observaciones efectuadas en pozos en arcilla y los resultados de un programa de estudio alemán sobre eliminación de residuos peligrosos han demostrado que, a profundidades de entre 10 y 30 m, la permeabilidad de la Arcilla Opalina decrece en varios órdenes de magnitud. Los ensayos hidráulicos realizados en sondeos más profundos (en intervalos situados a más de 300 m) proporcionaron conductividades hidráulicas inferiores a 10-12 m/s, pese a que algunos de los intervalos interceptaban juntas y fallas. Estas medidas son coherentes con los datos hidrogeológicos de las secciones de Arcilla Opalina existentes en 10 túneles del Jurásico Plegado, al norte de Suiza. A pesar de las fallas extensivas, apenas se hallaron indicios de entrada de

  18. Application of remote-sensing data to groundwater exploration: A case study of the Cross River State, southeastern Nigeria

    NASA Astrophysics Data System (ADS)

    Edet, A. E.; Okereke, C. S.; Teme, S. C.; Esu, E. O.

    té utilisées pour mettre en évidence certains phénomènes hydrologiques et hydrogéologiques en certains points de la région étudiée. L'analyse des réseaux de linéaments et de drainage a porté sur la densité de leurs longueurs et sur leur fréquence. La densité de longueur des linéaments s'étend de 0,04 à 1,52 et la fréquence des linéaments de 0,11 à 5,09 ; la densité des longueurs de drainage est comprise entre 0,17 et 0,94, et la fréquence du drainage entre 0,16 et 1,53. Ces gammes de valeurs rendent compte des différences dans la probabilité des potentiels en eau souterraine. Ces résultats ont ensuite été utilisés pour délimiter les zones à potentiel en eau souterraine fort, moyen et faible. Les résultats de l'étude indiquent aussi qu'il existe des corrélations entre les réseau de linéaments et de drainage, la lithologie, la température de l'eau, la conductivité de l'eau, le rendement des puits, la transmissivité, la conductance longitudinale et la présence d'eau souterraine. Resumen Bajo el Estado de Cross River, Nigeria, subyace un complejo basal cristalino del Precámbrico, así como rocas de edad entre Cretácica y Terciaria. La exploración hidrogeológica en esta área requiere una técnica sistemàtica para poder alcanzar resultados óptimos, pero la falta de medios y de infraestructura ha hecho extremadamente difícil el poder realizar investigaciones previas a la perforación de los pozos, de manera que el porcentaje de fallos se eleva al 80%. Para poder delinear las áreas adecuadas para el posterior desarrollo hidrogeológico, se han usado imágenes de radar en blanco y negro y fotografías aéreas, con el objetivo de definir algunos rasgos hidrológicos e hidrogeológicos en partes del área de estudio. Se analizaron los esquemas de lineamiento y drenaje usando densidad y frecuencia de longitudes. La densidad de longitudes de lineamiento oscila entre 0.04-1.52 y la frecuencia entre 0.11-5.09. La densidad de longitud de

  19. The migration, dissolution, and fate of chlorinated solvents in the urbanized alluvial valleys of the southwestern USA

    NASA Astrophysics Data System (ADS)

    Jackson, R. E.

    solvants chlorés piégés. Malgré leur faible solubilité dans l'eau, ces solvants denses sont suffisamment mobiles et solubles pour avoir produit, dans le sud-ouest des vallées alluviales, des panaches aqueux qui ont migré de plusieurs kilomètres dans les alluvions plus profondes et ont contaminé des champs captants pour l'eau potable en Californie, en Arizona et au Nouveau-Mexique. La longueur de ces panaches et la présence d'eau souterraine en conditions oxiques indiquent qu'il est peu probable que la décroissance naturelle soit un recours pratique de décontamination dans les vallées alluviales du sud-ouest ou dans d'autres systèmes alluviaux dans lesquels existent des conditions hydrogéologiques et géochimiques semblables. Resumen La migración, disolución y transporte de compuestos clorados en valles aluviales urbanos del sudoeste de los Estados Unidos de América parecen estar gobernados por un conjunto único de procesos hidrogeológicos y geoquímicos que tienen lugar en los depósitos clásticos. El relleno aluvial y lacustre de las cuencas, la inmovilización de los solutos en sedimentos de grano fino bajo las zonas urbanizadas, los condiciones óxicas típicas del aluvial profundo y las direcciones de transporte regidas por los fuertes bombeos en las cuencas se combinan para producir grandes penachos en fase acuosa procedentes de la disolución de los compuestos clorados atrapados en el medio. Aunque la solubilidad de estos compuestos clorados densos es pequeña, es suficiente para producir penachos que en algunos casos se han desplazado varios kilómetros a través del aluvial profundo y han llegado a contaminar zonas de extracción muy productivas en California, Arizona y Nuevo México. La longitud de estos penachos y la presencia de agua subterránea oxidante indican que es improbable que la degradación natural sea un buen método de limpieza de estos acuíferos o de otros sistemas aluviales que presenten características hidrogeológicas y

  20. Efectos de la irradiación iónica en hielos de moléculas carbonadas

    NASA Astrophysics Data System (ADS)

    Satorre, M. A.

    En Astrofísica podemos encontrar numerosos contextos en los cuales se observan moléculas en estado sólido que, en condiciones estándar de presión y temperatura, se encontrarían como gases o líquidos. Dichas moléculas se denominan hielos y han sido observadas en nubes densas del medio interestelar, en envolturas circumestelares, en satélites del Sistema Solar, en cometas, etc. Los hielos pueden ser alterados en su composición química debido a diversos factores como por ejemplo variaciones de temperatura o aportes energéticos por parte de la irradiación, ya sea tanto de fotones ultravioleta como de iones. Dependiendo del escenario astrofísico que analicemos, unos factores cobran más importancia que otros. Los experimentos de laboratorio muestran el efecto que produce sobre la composición de los hielos la irradiación iónica, en particular sobre los que contenían alguna molécula con átomos de carbono. Dicha composición se analiza con espectroscopía IR en el rango de 2 a ˜ 25μ m. La aplicabilidad de los resultados de los experimentos es distinta dependiendo de la composición química inicial de los hielos, del tipo de ion utilizado y de la dosis total de irradiación. Existen efectos generales de la irradiación sobre la materia en los experimentos de relevancia astrofísica como son: - la formación de nuevas moléculas, que pueden incluir o no el ion incidente; - la progresiva pérdida de hidrógeno (carbonización) cuando irradiamos muestras que originalmente contienen una determinada relación carbono/hidrógeno; - la variación de la temperatura de sublimación que presentan algunos hielos. Esto puede suceder tanto en hielos que estaban presentes antes de la irradiación como en hielos formados por ésta. Se presentará el papel del ion en la formación de nuevas moléculas a partir de las que originalmente se encontraban en el hielo. Al penetrar en él, el ion provoca distintos procesos como rotura de enlaces y excitaciones electr

  1. Lenguaje. Libro de maestro (Language. Teacher's Guide).

    ERIC Educational Resources Information Center

    Iribarren, Norma C.

    This teacher's manual is a guide for the lessons in the student's workbook, "Lenguaje." General objectives are given for each unit as well as specific objectives for each lesson. The detailed lesson plans are presented under four headings: (1) "Motivacion," (2) "Actividades de aprendizaje," (3) "Comprobacion," and (4) "Medios auciliares." (AMH)

  2. AN ACCURACY ASSESSMENT OF 1997 LANDSAT THEMATIC MAPPER DERIVED LAND COVER FOR THE UPPER SAN PEDRO WATERSHED (U.S./MEXICO)

    EPA Science Inventory

    High-Resolution airborne color video data were used to evaluate the accuracy of a land cover map of the upper San Pedro River watershed, derived from June 1997 Landsat Thematic Mapper data. The land cover map was interpreted and generated by Instituto del Medio Ambiente y el Bes...

  3. 78 FR 67389 - Endangered Species; Marine Mammals; Receipt of Applications for Permit

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-12

    ... specimens or condors originating in Mexico, to La Secretaria de Medio Ambiente y Rescoursos Naturales... Departments and Agencies of January 21, 2009--Transparency and Open Government (74 FR 4685; January 26, 2009... Federal Register (78 FR 40762; July 8, 2013) and reopens the 30-day comment period. Applicant: Guy...

  4. PROGRAMA PARA LA VERIFICACIN DE LA TECNOLOGIA AMBIENTAL/ENVIRONMENTAL TECHNOLOGY VERIFICATION PROGRAM (ETV) (EPA/600/F-98/015A)

    EPA Science Inventory

    A travs de su historia, la Agencia de Proteccin del Medio Ambiente estadounidense (U.S. Environmental Protection Agency, EPA) ha evaluado distintas tecnologas para determinar su efectividad en el monitoreo, la prevencin, el control, y la limpieza de la contaminacin ambiental. Sin...

  5. Reproduccion del ganado

    Technology Transfer Automated Retrieval System (TEKTRAN)

    La determination de prenez es una de las principales herramientas de manejo en el Ganado de came. Le habilidad de determiner prenez proporciona al productor un medio de tomar sus decsiones de seleccion y descartarte en momentos decisivos, enfocando los recursos de la operacion en reporductores confi...

  6. Middle Ear Infections and Ear Tube Surgery (For Parents)

    MedlinePlus

    ... Zika & Pregnancy Middle Ear Infections and Ear Tube Surgery KidsHealth > For Parents > Middle Ear Infections and Ear ... medio y colocación de tubos de ventilación Why Surgery? Many kids get middle ear infections (known as ...

  7. 76 FR 57983 - Notice of the Availability of the Draft Framework for the U.S.-Mexico Environmental Program...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-19

    ...The U.S. Environmental Protection Agency (EPA) and the Secretaria de Medio Ambiente y Recursos Naturales (Mexico's Secretariat of Environment and Natural Resources, SEMARNAT) is announcing the availability of the draft document, ``Border 2020: U.S.-Mexico Environmental Program''. Border 2020 is an eight-year, bi-national, results-oriented, environmental program for the U.S.-Mexico border......

  8. The CA3 Network as a Memory Store for Spatial Representations

    ERIC Educational Resources Information Center

    Papp, Gergely; Witter, Menno P.; Treves, Alessandro

    2007-01-01

    Comparative neuroanatomy suggests that the CA3 region of the mammalian hippocampus is directly homologous with the medio-dorsal pallium in birds and reptiles, with which it largely shares the basic organization of primitive cortex. Autoassociative memory models, which are generically applicable to cortical networks, then help assess how well CA3…

  9. Mixing against culture vs mixing against nature: ontologization of prohibited interethnic relationships.

    PubMed

    Roncarati, Alessandra; Pérez, Juan A; Ravenna, Marcella; Navarro-Pertusa, Esperanza

    2009-02-01

    ón consiste en la separación de algunos seres humanos de sus propias especies y en la reubicación de estos en otro medio ambiente, por ejemplo el de un animal. Nosotros suponemos basados en el famoso eslogan "igual pero diferente" que la representación social de una mixtura interracial es un fenómeno "antinatural". Se ha observado que relaciones sexuales entre personas de "razas" diferentes conllevan a un elevado nivel de ontologización. Desde una perspectiva biologista se explica esta mezcla racial en términos de un instinto natural o de impulsos animales ancestrales. En un experimento (N =  360) se presenta el caso de una mujer, que a pesar de estar en una relación estable, no es fiel a su pareja. En un dieseño con 2×3 factores se manipuló la identidad étnica-nacional de esta mujer (intragrupo español/italiano vs. exogrupo senegalés) y la identidad étnica-nacional de sus amantes (intragrupo español/italiano vs. exogrupo rumano vs. exogrupo senegalés). En general los resultados apoyan más claramente la hipótesis de la ontologización en condiciones interraciales, que la acostumbrada hipótesis relacionada con sesgos de favoritismo hacia el intragrupo y/o de discriminación hacia el exogrupo. Posteriormente se discutió en que medida un aproximación de tipo biologista posibilita una diferenciación a nivel humano, en términos de grupos culturales y grupos naturales, en "razas", de tal medida que relaciones sexuales interraciales son vistas como evidencia de un impulso salvaje e incontrolable, el cual estigmatiza a las personas envueltas en estas relaciones. PMID:22029437

  10. Modelizacion, control e implementacion de un procesador energetico paralelo para aplicacion en sistemas multisalida

    NASA Astrophysics Data System (ADS)

    Ferreres Sabater, Agustin

    modelizacion, y aplicacion en convertidores PWM, esta aun por estudiar y valorar. El primer Capitulo consiste en una breve introduccion al problema de la regulacion cruzada y la impedancia cruzada para posteriormente describir las tecnicas de post-regulacion actualmente mas empleadas, con especial atencion al post-regulador con transformador controlado. El Capitulo segundo trata del estudio de las caracteristicas estaticas del postregulador con transformador controlado. Partiendo de los estudios disponibles sobre el postregulador se plantean mejoras en su modo de actuacion y se discuten tres alternativas diferentes para controlar el transformador. Las dos primeras consisten en emplear un convertidor auxiliar Boost en sus dos modos de funcionamiento, continuo y discontinuo. La tercera consiste en controlar el transformador con una tension PWM directamente, sin filtrado. Finalmente se comprueba experimentalmente, para el estado estacionario, el funcionamiento del post-regulador para cada uno de los tres metodos de control. El Capitulo tercero trata de la dinamica de la salida controlada con el post-regulador cuando este emplea un convertidor auxiliar tipo Boost. Mediante la tecnica de promediado de variables de estado se propone el modelo de pequena senal, tanto para el modo continuo como para el modo discontinuo de funcionamiento del convertidor auxiliar. Los resultados mas significativos de esta seccion son las expresiones analiticas de las impedancias cruzadas y de la impedancia de la salida post-regulada. Como complemento al modelo de pequena senal se plantea un modelo de gran senal implementado sobre el simulador Pspice. Con este nuevo modelo se reproducen los resultados obtenidos con el modelo de pequena senal y ademas es posible simular los transitorios en las tensiones de salida ante cambios de carga. La modelizacion del convertidor cuando el transformador se controla con una tension PWM sin filtrar es el objetivo del Capitulo 4. En las secciones siguientes del Capitulo

  11. Energy Savers: Tips for Saving Energy and Money at Home; El Ahorro de Energa: Sugerencias para ahorrar energa y dinero en el hogar

    SciTech Connect

    Jones, J.

    2000-06-01

    The Department of Energy of the United States of America works to guarantee provisions of safe energy, reliable and economically accessible to support to one developing economy and to protect the atmosphere. These suggestions and ideas to increase the energy efficiency in their house represent simple ways in which our citizens can contribute to preserve the atmosphere at world-wide level, to reduce the level of contamination of the air and to reserve our natural resources for future generations. [Spanish] El Departamento de Energa de los Estados Unidos de America trabaja para garantizar suministros de energa seguros, confiables y econmicamente accesibles para apoyar a una economa en desarrollo y proteger el medio ambiente. Estas sugerencias e ideas para aumentar la eficiencia energetica en su casa representan maneras sencillas en que nuestros ciudadanos pueden contribuir a preservar el medio ambiente a nivel mundial, a reducir el nivel de contaminacin del aire y a reservar nuestros recursos naturales para las generaciones futuras.

  12. The new genus Pheude (Coleoptera, Curculionidae, Cossoninae) with description of a new species from mainland China

    PubMed Central

    Omar, Youssef M.; Zhang, Runzhi; Davis, Steven R.

    2014-01-01

    Abstract A new weevil, Pheude punctatus gen. et sp. n., of the tribe Dryotribini in Cossoninae, is described from Guangdong Province, South China. It differs from the related genera Dryotribus Horn and Microtribodes Morimoto in having antennae with seven articles and a distinct scutellum, and from Ochronanus Pascoe and Stenomimus Wollaston in having long antennae, a rostrum with a medio-longitudinal furrow beginning at the posterior margin of the eyes and extending approximately midway on the rostrum, and a moderately elevated, medio-longitudinal carina extending the full length of the pronotum. Other diagnostic characters and illustrations are provided. A key to the genera of Dryotribini known from China is given. PMID:25610334

  13. Condylar movements of temporomandibular disorder patients with intermittent lock: a pilot study.

    PubMed

    Yamaguchi, Taihiko; Komatsu, Kosetsu; Okada, Kazuki; Matsuki, Takamitsu; Gotouda, Akihito

    2007-01-01

    The purpose of this study was to clarify which direction of the condylar path is advantageous for releasing TMJ intermittent lock. The subjects were ten patients with temporomandibular disorders (TMD) and intermittent lock caused by anterior displacement of disks without obvious medial or lateral displacement. The patients could not open their mouths fully in habitual opening but could open fully in an intentional winding opening with reduction of the anteriorly displaced disks (winding opening). The two kinds of movement at the kinematic condylar point were measured in each subject and compared. The length of the condylar path in winding opening was significantly larger than that in habitual opening. The affected side condyle of winding opening traced medio-inferior paths in the early part of the condylar translation in comparison with habitual opening. From the viewpoint of the condylar path, the medio-inferior direction of condylar translation is thought to be advantageous for releasing intermittent lock. PMID:17304918

  14. Postcollapse Volcanism in the Valles Caldera, New Mexico: Magma System Dynamics During a Transition Between Large Volume Explosive and Small Volume Effusive Eruptions

    NASA Astrophysics Data System (ADS)

    Spell, T. L.; Gibler, K. I.

    2007-12-01

    The Valles Caldera formed during eruption of the ~250 km3 upper Bandelier Tuff at 1.26 Ma. Following caldera collapse a series of 3 intracaldera rhyolites (Deer Canyon, Redondo Creek and Del Medio) erupted within 54 ka. They are petrographically diverse, ranging from coarsely porphyritic (Deer Canyon type B, Redondo Creek) to nearly aphyric (Deer Canyon type A, Del Medio) and contain distinctive phenocryst assemblages. Disequilibrium textures are common and include resorbed quartz, strongly resorbed plagioclase, antirapikivi feldspars, and zoned sanidine and plagioclase. Plagioclase in Deer Canyon rhyolite ranges widely from labradorite (An60) to oligoclase (An24). Most are andesine in composition and often exhibit oscillatory zonation with overgrowths up to ~200 um wide. Alkali feldspars include both anorthoclase and sanidine with a total variability in Or content of ~50%. Plagioclase and alkali feldspars in Redondo Creek rhyolite show less variability, but similarly large ranges. One phenocryst exhibits an andesine core, oligoclase overgrowth, and sanidine rim. Del Medio rhyolite lacks plagioclase, but contains alkali feldspars (both anorthoclase and sanidine) with variability in Or content of ~30%. Patchy zonation is common, with Or content within phenocrysts varying by ~7%. Redondo Creek rhyolite ranges from ~72-74 wt.% SiO2 whereas Deer Canyon and Del Medio are high silica rhyolites with ~76-78 wt.% SiO2. Trace elements show more significant variability. Redondo Creek samples have low Nb, Rb, Sc, and Lu and high La, Sr, Ba and Hf compared to Del Medio samples. In contrast, Deer Canyon samples exhibit extreme variability in trace element concentrations (e.g., Nb ranging from 32-83 ppm). Incompatible trace element ratios (Th/Nb, Th/Yb, Ta/Yb) versus Nb plots show that Redondo Creek and Del Medio samples have distinctive, limited compositions, whereas Deer Canyon exhibits widely varying values (e.g., Th/Yb ranging from ~3.5-10.5). 238U/206Pb ion microprobe dating

  15. Sunrise-related headache: case report.

    PubMed

    Ulas, U H; Korkmaz, A; Karadas, O; Odabasi, Z; Reiter, R J

    2010-01-01

    A male, 34 years of age, suffers from headaches, red and watery eyes. The headaches began in childhood; the frequency of headaches has increased over the years and in the last decade headaches have occurred on a daily basis. If he wakes up before sunrise he feels much better and free of a headache; however, once he continues to sleep during and after sunrise, he suffers from tiredness, headache and nervousness. On magnetic resonance imaging (MRI), benign neuroepithelial cysts or a chronic infarct area was reported at the junction of the left medio-lateral zone of hypothalamus. After repeated MRI examinations, it was decided that the lesion on the left medio-lateral zone of hypothalamus may have disrupted the pineal gland and changed melatonin secretion. It was decided to treat him with 3 mg melatonin daily before going to bed. After a week of treatment, the patient reported that he felt very fresh and was virtually free of headaches. PMID:19473198

  16. Quantitative three-dimensional shape analysis of the proximal hallucial metatarsal articular surface in Homo, Pan, Gorilla, and Hylobates.

    PubMed

    Proctor, Daniel J; Broadfield, Douglas; Proctor, Kristopher

    2008-02-01

    Multidimensional morphometrics is used to compare the proximal articular surface of the first metatarsal between Homo, Pan, Gorilla, Hylobates, and the hominin fossils A.L. 333-54 (A. afarensis), SKX 5017 (P. robustus), and OH 8 (H. habilis). Statistically significant differences in articular surface morphology exist between H. sapiens and the apes, and between ape groups. Ape groups are characterized by greater surface depth, an obliquely curved articular surface through the dorso-lateral and medio-plantar regions, and a wider medio-lateral surface relative to the dorso-plantar height. The OH 8 articular surface is indistinguishable from H. sapiens, while A.L. 333-54 and SKX 5017 more closely resemble the apes. P. robustus and A. afarensis exhibit ape-like oblique curvature of the articular surface. PMID:18046775

  17. Observación solar desde el espacio, resultados recientes

    NASA Astrophysics Data System (ADS)

    Machado, M. E.

    Presentaremos un resumen de los resultados más recientes sobre la física del sol, obtenidos por medio del análisis de datos de satélites artificiales como el Yohkoh, SOHO y COMPTON/GRO. En particular, nos referiremos a la acción y dinámica de los campos magnéticos en la generación de fenómenos activos y el calentamiento coronal.

  18. Ponte en onda: prende la energía limpia, (Spanish) Get Current

    SciTech Connect

    2015-05-01

    Cambiar a tecnologías de energía limpia significa que fortalecemos la economía y protegemos al medio ambiente. Este libreto de actividades educativas para todas las edades promueve el uso consciente de la energía, con datos de distintas formas de energía aplicables y una variedad de rompecabezas y crucigramas en temas energéticos.

  19. Effects of structural and functional cerebellar lesions on sensorimotor adaptation of saccades.

    PubMed

    Panouillères, M; Alahyane, N; Urquizar, C; Salemme, R; Nighoghossian, N; Gaymard, B; Tilikete, C; Pélisson, D

    2013-11-01

    The cerebellum is critically involved in the adaptation mechanisms that maintain the accuracy of goal-directed acts such as saccadic eye movements. Two categories of saccades, each relying on different adaptation mechanisms, are defined: reactive (externally triggered) saccades and voluntary (internally triggered) saccades. The contribution of the medio-posterior part of the cerebellum to reactive saccades adaptation has been clearly demonstrated, but the evidence that other parts of the cerebellum are also involved is limited. Moreover, the cerebellar substrates of voluntary saccades adaptation have only been marginally investigated. Here, we addressed these two questions by investigating the adaptive capabilities of patients with cerebellar or pre-cerebellar stroke. We recruited three groups of patients presenting focal lesions located, respectively, in the supero-anterior cerebellum, the infero-posterior cerebellum and the lateral medulla (leading to a Wallenberg syndrome including motor dysfunctions similar to those resulting from lesion of the medio-posterior cerebellum). Adaptations of reactive saccades and of voluntary saccades were tested during separate sessions in all patients and in a group of healthy participants. The functional lesion of the medio-posterior cerebellum in Wallenberg syndrome strongly impaired the adaptation of both reactive and voluntary saccades. In contrast, patients with lesion in the supero-anterior part of the cerebellum presented a specific adaptation deficit of voluntary saccades. Finally, patients with an infero-posterior cerebellar lesion showed mild adaptation deficits. We conclude that the medio-posterior cerebellum is critical for the adaptation of both saccade categories, whereas the supero-anterior cerebellum is specifically involved in the adaptation of voluntary saccades. PMID:23963603

  20. Visiting Richard Serra’s “Promenade” sculpture improves postural control and judgment of subjective visual vertical

    PubMed Central

    Kapoula, Zoï; Lang, Alexandre; Lê, Thanh-Thuan; Adenis, Marie-Sarah; Yang, Qing; Lipede, Gabi; Vernet, Marine

    2014-01-01

    Body sway while maintaining an upright quiet stance reflects an active process of balance based on the integration of visual, vestibular, somatosensory, and proprioceptive inputs. Richard Serra’s Promenade sculpture featured in the 2008 Monumenta exhibition at the Grand Palais in Paris, France is herein hypothesized to have stimulated the body’s vertical and longitudinal axes as it showcased five monumental rectangular solids pitched at a 1.69° angle. Using computerized dynamic posturography we measured the body sway of 23 visitors when fixating a cross, or when observing the artwork (fixating it or actively exploring it with eye movements) before and after walking around and alongside the sculpture (i.e., before and after a promenade). A first fixation at the sculpture increased medio-lateral stability (in terms of spectral power of body sway). Eye movement exploration in the depth of the sculpture increased antero-posterior stability [in terms of spectral power and canceling time (CT) of body sway] at the expense of medio-lateral stability (in terms of CT). Moreover, a medio-lateral instability associated with eye movement exploration before the promenade (in terms of body sway sensu stricto) was canceled after the promenade. Finally, the overall medio-lateral stability (in terms of spectral power) increased after the promenade. Fourteen additional visitors were asked to stand in a dark room and adjust a luminous line to what they considered to be the earth-vertical axis. The promenade executed within the sculpted environment afforded by Serra’s monumental statuary works resulted in significantly improved performances on the subjective visual vertical test. We attribute these effects to the sculpted environment provided by the exhibition which may have acted as a kind of physiologic “training ground” thereby improving the visitors’ overall sense of visual perspective, equilibrium, and gravity. PMID:25566107

  1. Visiting Richard Serra's "Promenade" sculpture improves postural control and judgment of subjective visual vertical.

    PubMed

    Kapoula, Zoï; Lang, Alexandre; Lê, Thanh-Thuan; Adenis, Marie-Sarah; Yang, Qing; Lipede, Gabi; Vernet, Marine

    2014-01-01

    Body sway while maintaining an upright quiet stance reflects an active process of balance based on the integration of visual, vestibular, somatosensory, and proprioceptive inputs. Richard Serra's Promenade sculpture featured in the 2008 Monumenta exhibition at the Grand Palais in Paris, France is herein hypothesized to have stimulated the body's vertical and longitudinal axes as it showcased five monumental rectangular solids pitched at a 1.69(°) angle. Using computerized dynamic posturography we measured the body sway of 23 visitors when fixating a cross, or when observing the artwork (fixating it or actively exploring it with eye movements) before and after walking around and alongside the sculpture (i.e., before and after a promenade). A first fixation at the sculpture increased medio-lateral stability (in terms of spectral power of body sway). Eye movement exploration in the depth of the sculpture increased antero-posterior stability [in terms of spectral power and canceling time (CT) of body sway] at the expense of medio-lateral stability (in terms of CT). Moreover, a medio-lateral instability associated with eye movement exploration before the promenade (in terms of body sway sensu stricto) was canceled after the promenade. Finally, the overall medio-lateral stability (in terms of spectral power) increased after the promenade. Fourteen additional visitors were asked to stand in a dark room and adjust a luminous line to what they considered to be the earth-vertical axis. The promenade executed within the sculpted environment afforded by Serra's monumental statuary works resulted in significantly improved performances on the subjective visual vertical test. We attribute these effects to the sculpted environment provided by the exhibition which may have acted as a kind of physiologic "training ground" thereby improving the visitors' overall sense of visual perspective, equilibrium, and gravity. PMID:25566107

  2. Cavernomas de la región temporal mesial: Anatomía microquirúrgica y abordajes

    PubMed Central

    Campero, Alvaro

    2015-01-01

    Objetivo: Describir la anatomía microquirúrgica y los abordajes a la región temporal mesial (RTM), en relación a cavernomas de dicho sector. Materiales y Método: Cinco cabezas de cadáveres adultos, fijadas en formol e inyectadas con silicona coloreada, fueron estudiadas. Además, desde enero de 2007 a junio de 2014, 7 pacientes con cavernomas localizados en la RTM fueron operados por el autor. Resultados: Anatomia: La RTM fue dividida en 3 sectores: Anterior, medio y posterior. Pacientes: 7 enfermos con cavernomas de la RTM fueron operados por el autor. De acuerdo a la ubicacion en la RTM, 4 cavernomas se ubicaron en el sector anterior, 2 cavernomas se localizaron en el sector medio y 1 cavernoma se ubico en el sector posterior. Para el sector anterior de la RTM se utilizo un abordaje transsilviano-transinsular; para el sector medio de la RTM se utilizo un abordaje transtemporal (lobectomia temporal anterior); y para el sector posterior de la RTM se utilizo un abordaje supracerebeloso-transtentorial. Conclusión: Dividir la RTM en 3 sectores nos permite adecuar el abordaje en función a la localización de la lesión. Así, el sector anterior es bien abordable a través de la fisura silviana; el sector medio a través de una vía transtemporal; y el sector posterior por un abordaje supracerebeloso. PMID:26600986

  3. Application of vibrotactile feedback of body motion to improve rehabilitation in individuals with imbalance

    PubMed Central

    Wall, Conrad

    2010-01-01

    Background and Purpose Balance rehabilitation and vestibular/balance prostheses are both emerging fields that have a potential for synergistic interaction. This paper reviews vibrotactile prosthetic devices that have been developed to date and ongoing work related to the application of vibrotactile feedback for enhanced postural control. A vibrotactile feedback device developed in the author’s laboratory is described. Methods Twelve subjects with vestibular hypofunction were tested on a platform that moved randomly in a plane, while receiving vibrotactile feedback in the anterio-posterior direction. The feedback allowed subjects to significantly decrease their anterio-posterior body tilt, but did not change mediolateral tilt. A tandem walking task using subjects with vestibulopathies demonstrated a reduction in their medio-lateral sway due to vibrotactile feedback of medio-lateral body tilt, after controlling for the effects of task learning. The findings from two additional experiments conducted in the laboratories of collaborating physical therapists are summarized. Results The Dynamic Gait Index scores in community-dwelling elderly individuals who were prone-to-fall were significantly improved with the use of medio-lateral body tilt feedback. Discussion and Conclusions While more work is needed, these results suggest that vibrotactile tilt feedback of subjects’ body motion can be used effectively by physical therapists for balance rehabilitation. A preliminary description of the 3rd generation device that has been reduced from a vest format to a belt format is described to demonstrate the progressive evolution from research to clinical application. PMID:20588096

  4. Effects of Alexander Technique training experience on gait behavior in older adults.

    PubMed

    O'Neill, Matthew M; Anderson, David I; Allen, Diane D; Ross, Christopher; Hamel, Kate A

    2015-07-01

    Heightened fall risk, potentially caused by aging-related changes in gait, is a serious health issue faced by older adults. The Alexander Technique is thought to improve balance and motor function; however, the technique's effect on gait has not been studied. The purpose of this study was to examine the effect of Alexander Technique training in older adults on the temporospatial characteristics of gait and medio-lateral center of mass displacement during fast and comfortably paced over-ground walking. Six licensed Alexander Technique teachers and seven controls between the ages of 60 and 75 years of age participated in the study. Alexander Technique teachers exhibited a reduction in medio-lateral center of mass displacement during fast paced walking compared to comfortably paced walking that was not present in controls. Due to this difference Alexander Technique teachers displayed a smaller medio-lateral Center of Mass displacement compared to controls during fast paced walking. Alexander Technique teachers also demonstrated significantly smaller stride width and lower gait timing variability compared to controls. These findings, which suggest superior control of dynamic stability during gait and potentially reduced fall risk in Alexander Technique teachers, warrant further study. PMID:26118520

  5. The role of central vision in posture: Postural sway adaptations in Stargardt patients.

    PubMed

    Agostini, Valentina; Sbrollini, Agnese; Cavallini, Chanda; Busso, Alessandra; Pignata, Giulia; Knaflitz, Marco

    2016-01-01

    The role of central and peripheral vision in the maintenance of upright stance is debated in literature. Stargardt disease causes visual deficits affecting the central field, but leaving unaltered a patient's peripheral vision. Hence, the study of this rare pathology gives the opportunity to selectively investigate the role of central vision in posture. Postural sway in quiet stance was analyzed in 10 Stargardt patients and 10 control subjects, in three different conditions: (1) eyes closed, (2) eyes open, gazing at a fixed target, and (3) eyes open, tracking a moving target. Stargardt patients outperformed controls in the condition with eyes closed, showing a reduced root mean square (RMS) of the medio-lateral COP displacement, while their performance was not significantly different from controls in the antero-posterior direction. There were no significant differences between patients and controls in open eyes conditions. These results suggest that Stargardt patients adapted to a different visual-somatosensory integration, relying less on vision, especially in the medio-lateral direction. Hence, the central vision seems to affect mostly the medio-lateral direction of postural sway. This finding supports the plausibility of the "functional sensitivity hypothesis", that assigns complementary roles to central and peripheral vision in the control of posture. PMID:26514831

  6. Dipole source localization of interictal epileptiform activity in temporal lobe epilepsy with medial temporal lesion.

    PubMed

    Mine, S; Iwasa, H; Nakajima, Y; Yamaura, A

    2000-02-01

    Dipole sources of interictal epileptiform activities recorded by conventional electroencephalogram (EEG) were estimated using the dipole tracing method. Four cases of temporal lobe epilepsy with medial temporal lesions were studied. Two patients with hippocampal sclerosis, one patient with granulation in the hippocampus and one patient with cavernous angioma were involved in the study. Interictal epileptiform activities were classified into two patterns according to the topography of spikes. They were widespread spikes over the parasagittal electrodes (parasagittal spikes) and restricted spikes at the temporal electrodes (temporal spikes). Dipole sources of parasagittal spikes were localized in the medio-basal temporal lobe with vertically orientated vector moment. Dipole sources of temporal spikes were localized in the medio-basal temporal lobe with horizontally orientated vector moment. Locations of dipoles and directions of vector moments were consistent with topography and polarity of spikes. The difference in the two patterns of interictal epileptiform activities was derived from the difference in the direction of the vector moment of dipole sources. There was no difference in the location of dipole sources. Both the dipole sources and the lesions were localized in the same medio-basal temporal lobe. Dipole tracing was very useful in localizing the dipole sources of interictal epileptiform activities and in understanding the neurophysiological background. PMID:15558875

  7. Unificando los criterios de sepsis neonatal tardía: propuesta de un algoritmo de vigilancia diagnóstica

    PubMed Central

    Zea-Vera, Alonso; Turin, Christie G.; Ochoa, Theresa J.

    2015-01-01

    Las infecciones constituyen una de las principales causas de muerte en el periodo neonatal. El diagnóstico de sepsis neonatal representa un gran desafío ya que los recién nacidos presentan signos clínicos muy inespecíficos y los exámenes auxiliares tienen una baja sensibilidad. Con el objetivo de mejorar el diagnóstico correcto de esta patología proponemos un algoritmo de vigilancia diagnóstica para sepsis neonatal tardía en el Perú y países de la región. El algoritmo permite clasificar a los episodios como sepsis confirmada, probable o posible, y sobretodo busca identificar aquellos episodios que no corresponden a sepsis, evitando calificar otras patologías como “sepsis”. Un mejor diagnóstico permitiría tener tasas más reales de sepsis neonatal, mejorar el uso de antibióticos y evitar sus efectos negativos en el recién nacido, así como una visión más exacta de su impacto en la salud pública. PMID:25123879

  8. Development of the Commonwealth of Puerto Rico National Protocol for the Management of Victims of Sexual Violence: Adults/Adolescents.

    PubMed

    Méndez, Rose Marie; Kulbok, Pamela; Lawson, Sarah; Matos, Abigail

    2013-01-01

    Sexual violence is a public health problem in Puerto Rico (PR), with an incidence of 7.4 cases for every 10,000 people during 2005-2006 (Departamento de Salud Secretaría Auxiliar de Salud Familiar y Servicios Integrados, 2007). Findings from the literature review indicated that the traditional model of care provided to the victims of sexual violence in the Emergency Department is incomplete; furthermore, it may cause revictimization because of the attitudes, behaviors, and practices of the community service providers, resulting in additional trauma. Emerging evidence demonstrates that Sexual Assault Nurse Examiner (SANE) programs are providing effective quality care. In PR, SANEs do not intervene in sexual assault cases; nevertheless, the Department of Health of PR has recognized the importance of SANE intervention. Consequently, there is a need for current evidence-based protocols and standards of care to describe the procedures, roles, and responsibilities for the provision of quality care to victims. This project involves the implementation of the Stufflebeam's Context-Input-Process-Product Model in the creation of the Commonwealth of Puerto Rico National Protocol for the Management of Victims of Sexual Violence: Adults/Adolescents. PMID:24158134

  9. Un nuevo estudio del cúmulo abierto Tr 14 en la región de Carina

    NASA Astrophysics Data System (ADS)

    García, B.; Malaroda, S.; Levato, H.; Morrell, N.

    Presentamos nuevos datos espectroscópicos de 9 objetos entre los miembros más brillantes de Tr 14. Hemos medido un total de 80 nuevos espectrogramas para contribuir a la determinación de la real naturaleza de estos objetos desde el punto de vista de la duplicidad. Del nuevo material debemos concluir que la mayoría de las estrellas en la muestra son simples. Sin embargo existen algunos objetos cuyo seguimiento debe continuar ya que no nos es posible efectuar conclusiones definitivas con el presente material.

  10. ?Cuales son las amenazas o peligros volcanicos?

    USGS Publications Warehouse

    Myers, Bobbie; Brantley, Steven R.; Stauffer, Peter; Hendley, James W., II

    2000-01-01

    Los volcanes son capaces de producir numerosos peligros geologicos e hidrologicos. Los cientificos del Servicio Geologico de los EE. UU. (USGS, por sus siglas en ingles) y de otras instituciones alrededor del mundo estan estudiando los peligros de muchos de los centenares de volcanes activos y potencialmente activos del mundo. Estos cientificos vigilan muy de cerca la actividad de algunos de los volcanes mas peligrosos, por lo que estan preparados para alertar a las autoridades y/o a la poblacion en caso de que aumente sustancialmente la probabilidad de que ocurra una erupcion u otro evento peligroso.

  11. Eventos Planetarios Periodicos

    NASA Astrophysics Data System (ADS)

    Flores Gutierrez, J. D.

    1987-05-01

    El análisis de las coordenadas ecuatoriales para los planetas Mercurio, Venus, Marte, Júpiter, Saturno, en los instantes en que ocurren algunos eventos astronómicos, como conjunciones, oposiciones,etc., muestra un comportamiento periódico, característico a cada planeta. El caso de Venus es el mejor estudiado. El cálculo de las efemérides a lo largo de 1000 años , indica un período característico de aproximadamente 260 años. Resultados preliminares con otros planetas muestran períodos distintos.

  12. Formación y evolución de planetas gigantes

    NASA Astrophysics Data System (ADS)

    Benvenuto, O. G.; Brunini, A.

    Presentamos el estado actual del trabajo que estamos realizando en el estudio de la formación de planetas gigantes. Detallamos los algoritmos numéricos necesarios para realizar este tipo de cálculo. Presentamos algunos resultados de la formación de objetos con masas de hasta una docena de veces la del planeta Júpiter, resaltando las principales caracteríticas. Finalmente detallamos los problemas que pensamos abordar en un futuro cercano en este tema de investigación.

  13. Deep-tissue confocal imaging of the central projections of ovipositor sensory afferents in the Egyptian cotton leafworm, Spodoptera littoralis.

    PubMed

    Seada, Mervat A; Ghaninia, Majid

    2016-03-01

    The pre-ovipositon behavior of moths is largely dependent upon the cues that a gravid female perceives while assessing potential oviposition sites. Assessment of such sites is accomplished, at least in part, by mechanosensory and gustatory sensilla located on the ovipositor whose sensory neurons project into the terminal abdominal ganglion (TAG). Using anterograde backfill staining, confocal laser scanning microscopy, and three dimensional reconstruction, we traced and analyzed the central projections of the sensory neurons housed in the sensilla located on the ovipositor papillae and explored the neuropilar composition of the TAG in the Egyptian cotton leafworm, Spodoptera littoralis. The TAG consists of three fused neuromeres (6-8th Ner) associated with the 6-8th abdominal segments. Within the TAG, and specifically in the 8th neuromere, four unstructured neuropilar compartments are present; the dorso-ipsilateral motor neuropil (MN), the medio-ipsilateral mechanosensory neuropil (MchN), the medio-ipsilateral small gustatory neuropil (GN), and the medio-contralateral posterior ovipositor glomerulus (Og). The Og appears quite compact, with a hollow core free of terminal arborizations. The MchN is further subdivided into 4 unstructured glomeruli in the 8th neuromere, whose afferents are subsequently extended into 3 glomeruli in the 7th and 6th neuromeres. Few neurites of the Og are populated with large dense varicosities reminiscent of neurosecretory vesicles. Given that all ovipositor nerves converge into a common ganglionic center, the TAG, we assume that this ganglion may be a center for coordination of oviposition behaviors, including movements of the ovipositor during assessment of oviposition substrates and egg laying in S. littoralis. PMID:26774745

  14. Fluvio-lacustrine sedimentation and volcanism in a Late Carboniferous tensional intra-arc basin, northern Chile

    NASA Astrophysics Data System (ADS)

    Breitkreuz, Christoph

    1991-11-01

    Extensive outcrops of Late Carboniferous to Triassic volcanoplutonic magnetic-arc complexes occur in the Andes of northern Chile. In the Salar de Atacama area, terrestrial volcanosedimentary successions include a 200-600 m thick fluvio-lacustrine sequence ("Miembro Medio"). The terrestrial basin which accommodated this sequence formed during the latest Carboniferous on top of the deposits of the pre-existing Carboniferous composite volcanoes. The lower part of the Miembro Medio consists of green limnic and multicoloured alluvial fan deposits; the upper part is made up of red fluvial sedimentary rocks. Basic volcanic rocks occur locally throughout the sequence. The climate is inferred to have been warm and humid. The limnic (freshwater) environment had a minimum extension of 300 × 100 km. Limnic facies is inferred from the existence of fine-parallel-bedded sediments, ooliths and a limnic benthic fauna. Lake-shore deposits prevail in the outcrops. In some sections, the green limnic sequence is followed by red fine-grained floodplain or alluvial plain, and fluvial channel deposits. The framework composition of the Miembro Medio is dominated by volcanogenic detritus presumably eroded from the successions of the previous Late Carboniferous volcanic arc. Another volcanogenic clast type was provided by syndepositional basalto-andesitic phreatomagmatic activity, which also produced peperitic sills, dykes and lavas. The limnic-alluvial fan facies association, the predominance of volcanogenic detritus, and the accompanying intrabasinal basic calc-alkaline volcanism together with the considerable size of the basin point to a ?NW-SE trending half-graben setting controlled by (trans-)tensional arc tectonics. With regard to the Late Carboniferous-Triassic volcanosedimentary successions of northern Chile, this Latest Carboniferous tensional setting is the only feature in this area supporting those models, which inferred an extensional magmatic arc for the entire Central and

  15. Muscle contributions to centre of mass acceleration during turning gait in typically developing children: A simulation study.

    PubMed

    Dixon, Philippe C; Jansen, Karen; Jonkers, Ilse; Stebbins, Julie; Theologis, Tim; Zavatsky, Amy B

    2015-12-16

    Turning while walking requires substantial joint kinematic and kinetic adaptations compared to straight walking in order to redirect the body centre of mass (COM) towards the new walking direction. The role of muscles and external forces in controlling and redirecting the COM during turning remains unclear. The aim of this study was to compare the contributors to COM medio-lateral acceleration during 90° pre-planned turns about the inside limb (spin) and straight walking in typically developing children. Simulations of straight walking and turning gait based on experimental motion data were implemented in OpenSim. The contributors to COM global medio-lateral acceleration during the approach (outside limb) and turn (inside limb) stance phase were quantified via an induced acceleration analysis. Changes in medio-lateral COM acceleration occurred during both turning phases, compared to straight walking (p<0.001). During the approach, outside limb plantarflexors (soleus and medial gastrocnemius) contribution to lateral (away from the turn side) COM acceleration was reduced (p<0.001), whereas during the turn, inside limb plantarflexors (soleus and gastrocnemii) contribution to lateral acceleration (towards the turn side) increased (p≤0.013) and abductor (gluteus medius and minimus) contribution medially decreased (p<0.001), compared to straight walking, together helping accelerate the COM towards the new walking direction. Knowledge of the changes in muscle contributions required to modulate the COM position during turning improves our understanding of the control mechanisms of gait and may be used clinically to guide the management of gait disorders in populations with restricted gait ability. PMID:26555714

  16. The peats of Costa Rica

    SciTech Connect

    Obando A, L.; Malavassi R, L.; Ramirez E, O. ); Cohen, A. . Dept. of Geological Sciences); Raymond, R. Jr.; Thayer, G.R. )

    1991-04-01

    The objectives of this investigation were: (1) to locate potential peat deposits in Costa Rica; (2) to estimate as closely as possible by representative sampling the amount of peat present in each deposit, and (3) to make a preliminary evaluation of the quality of the peat in each deposit. With information from soil maps and a 3-week survey of Costa Rica, it is estimated that a potential area of about 1000 km{sup 2} is covered by peat. Most of the peat area (about 830 km{sup 2}) is in northeastern Costa Rica in the Tortuguero area. An aerial survey identified the potential peat areas by the exclusive presence of the Yolillo palm. The next largest potential area of peat (about 175 km{sup 2}) is in the cloud-covered areas of the Talamanca Mountains. Some reconnaissance has been done in the Talamanca Mountains, and samples of the peat indicate that it is very similar to the sphagnum peat moss found in Canada and the northern US. Smaller bogs have been discovered at Medio Queso, El Cairo, Moin, and the Limon airport. Two bogs of immediate interest are Medio Queso and El Cairo. The Medio Queso bog has been extensively sampled and contains about 182,000 metric tons (dry) of highly decomposed peat, which is being used as a carrier for nitrogen-fixing bacteria. The El Cairo bog is sparsely sampled and contains about 1,300,000 metric tons of slightly decomposed dry peat. Plans are to use this peat in horticultural applications on nearby farms. 10 refs., 11 figs., 7 tabs.

  17. Local cerebral glucose utilisation in chronic alcoholics: a positron tomographic study.

    PubMed Central

    Samson, Y; Baron, J C; Feline, A; Bories, J; Crouzel, C

    1986-01-01

    Using positron tomography, a study of regional cerebral glucose utilisation was performed prospectively in a highly selected group of six neurologically unaffected primary chronic alcoholics. In this group, neuropsychological, behavioural and CT scan anomalies were comparable with those previously reported in more extensive studies. With respect to age-matched control values, cerebral metabolic rate was not significantly modified in the selected cortical, subcortical and cerebellar regions of interest. However, the metabolic regional distribution index, which reflects the distribution pattern of glucose utilisation, was selectively and significantly decreased in the medio-frontal area, pointing to a limbic metabolic dysfunction apparently linked to chronic alcoholism. Images PMID:3491181

  18. [In Process Citation].

    PubMed

    Ballesteros Pomar, María D; Suárez Gutiérrez, Alfonso; Calleja Fernández, Alicia; Pintor de la Maza, Begoña; Urioste Fondo, Ana; Vidal Casariego, Alfonso; Villar Taibo, Rocío; Otero Redondo, Concepción; Herrero Moratiel, Manuel; Cano Rodríguez, Isidoro; Burón Llamazares, Juan Luis

    2016-01-01

    Introducción: la desnutrición relacionada con la enfermedad (DRE) afecta al menos a una cuarta parte de los pacientes hospitalizados, aumentando la morbimortalidad del paciente durante su hospitalización y al alta. Sin embargo, su repercusión en la actividad hospitalaria no está bien cuantificada.Objetivo: determinar el impacto de una adecuada codificación de la DRE y los procedimientos empleados para revertirla en el peso medio del hospital y otros índices hospitalarios.Material y métodos: estudio comparativo realizado en todos los pacientes subsidiarios de soporte nutricional artificial seguidos por la Unidad de Nutrición Clínica y Dietética de la Sección de Endocrinología y Nutrición (UNCyD-SEyN) del Complejo Asistencial Universitario de León durante los años 2008 y 2013. Se realizó un informe de codificación nutricional del diagnóstico, el tratamiento nutricional y la vía de acceso según la CIE-9-MC. Se comparó el peso medio depurado del hospital, el índice de estancia media ajustada (IEMA), la casuística e índice de funcionamiento previo a la codificación nutricional y tras la misma.Resultados: el peso medio depurado del hospital se incrementó tras la codificación, tanto en 2008 (+ 4,1%) como en 2013 (+1,7%) y especialmente en aquellos servicios en los que se realiza cribado nutricional (Hematología, +10,5%). El IEMA se redujo por debajo de 1 (-5,7% y -0,2% en 2008 y 2013), indicando un mejor funcionamiento, y también disminuyó el índice funcional (-5,6% y -0,4% en 2008 y 2013), lo que supondría una mayor eficiencia.Conclusión: la correcta codificación del diagnóstico y el tratamiento nutricional del paciente con desnutrición aumenta el peso medio depurado de un hospital de tercer nivel, y mejora el IEMA y el índice de funcionamiento. PMID:27019251

  19. The MCH neuron population as a model for the development and evolution of the lateral and dorsal hypothalamus.

    PubMed

    Chometton, Sandrine; Croizier, Sophie; Fellmann, Dominique; Risold, Pierre-Yves

    2016-09-01

    The LHA contains neurons producing melanin-concentrating hormone (MCH) or hypocretin (Hcrt) that have emerged as being more conspicuous and representative of the posterior LHA. In this review, we focus on MCH neurons and show that they have unique qualities. Their distribution is conserved in the posterior hypothalamus of all vertebrates and their ontogenetic differentiation is very precocious in the rodent embryo. In mammals, interspecific differences in their medio-lateral distribution suggest that the LHA differentiation may follow species specific strategies. These characteristics make a very valuable tool of MCH neurons to study the development as well as the phylogenetical origin and differentiation of the LHA. PMID:26459022

  20. Calcium imaging of sleep–wake related neuronal activity in the dorsal pons

    PubMed Central

    Cox, Julia; Pinto, Lucas; Dan, Yang

    2016-01-01

    The dorsal pons has long been implicated in the generation of rapid eye movement (REM) sleep, but the underlying circuit mechanisms remain poorly understood. Using cell-type-specific microendoscopic Ca2+ imaging in and near the laterodorsal tegmental nucleus, we found that many glutamatergic neurons are maximally active during REM sleep (REM-max), while the majority of GABAergic neurons are maximally active during wakefulness (wake-max). Furthermore, the activity of glutamatergic neurons exhibits a medio-lateral spatial gradient, with medially located neurons more selectively active during REM sleep. PMID:26911837

  1. Burbujas interestelares alrededor de estrellas masivas: observaciones en frecuencias de Radio

    NASA Astrophysics Data System (ADS)

    Cappa, C.

    Los vientos estelares de estrellas masivas interactúan con el medio interestelar circundante originando burbujas interestelares que pueden detectarse en diversas bandas del espectro electromagnético, incluyendo la banda de radio. En esta presentación se hace una puesta al día de los resultados obtenidos a partir de observaciones en el continuo de radio y en líneas espectrales en dirección de estas estructuras. Estas observaciones nos permiten estudiar el material ionizado, atómico y molecular asociado a las burbujas interestelares.

  2. Contribución al flujo infrarrojo de las estrellas Be de la recombinación dielectrónica del MgII

    NASA Astrophysics Data System (ADS)

    Cruzado, A.; di Rocco, H.; Ringuelet, A.

    Para evaluar la contribución del proceso de recombinación dielectrónica del átomo de MgII al exceso de flujo infrarrojo observado en las estrellas Be, calculamos la energía emitida en las líneas originadas por este proceso. Se evaluaron los efectos de las condiciones físicas del medio, como la temperatura electrónica y la densidad electrónica, sobre el flujo emitido. Se consideró también la influencia de una posible opacidad.

  3. Factors Affecting Open-Set Word Recognition in Adults with Cochlear Implants

    PubMed Central

    Holden, Laura K.; Finley, Charles C.; Firszt, Jill B.; Holden, Timothy A.; Brenner, Christine; Potts, Lisa G.; Gotter, Brenda D.; Vanderhoof, Sallie S.; Mispagel, Karen; Heydebrand, Gitry; Skinner, Margaret W.

    2012-01-01

    A monosyllabic word test was administered to 114 postlingually-deaf adult cochlear implant (CI) recipients at numerous intervals from two weeks to two years post-initial CI activation. Biographic/audiologic information, electrode position, and cognitive ability were examined to determine factors affecting CI outcomes. Results revealed that Duration of Severe-to-Profound Hearing Loss, Age at Implantation, CI Sound-field Threshold Levels, Percentage of Electrodes in Scala Vestibuli, Medio-lateral Electrode Position, Insertion Depth, and Cognition were among the factors that affected performance. Knowledge of how factors affect performance can influence counseling, device fitting, and rehabilitation for patients and may contribute to improved device design. PMID:23348845

  4. Sistemas de cúmulos globulares extragalácticos

    NASA Astrophysics Data System (ADS)

    Forte, J. C.

    Se describen las características de los sistemas de cúmulos globulares asociados a galaxias elípticas en una variedad de medios y, en particular, aquellas vinculadas con la distribución espacial, frecuencia específica y composición química. Esta discusión se hace dentro de un conjunto de esquemas orientados a explicar las primeras fases de la formación de las galaxias dominantes en cúmulos y del rol de los sistemas de cúmulos globulares en esos procesos.

  5. Amygdala atrophy affects emotion-related activity in face-responsive regions in frontotemporal degeneration.

    PubMed

    De Winter, François-Laurent; Van den Stock, Jan; de Gelder, Beatrice; Peeters, Ronald; Jastorff, Jan; Sunaert, Stefan; Vanduffel, Wim; Vandenberghe, Rik; Vandenbulcke, Mathieu

    2016-09-01

    In the healthy brain, modulatory influences from the amygdala commonly explain enhanced activation in face-responsive areas by emotional facial expressions relative to neutral expressions. In the behavioral variant frontotemporal dementia (bvFTD) facial emotion recognition is impaired and has been associated with atrophy of the amygdala. By combining structural and functional MRI in 19 patients with bvFTD and 20 controls we investigated the neural effects of emotion in face-responsive cortex and its relationship with amygdalar gray matter (GM) volume in neurodegeneration. Voxel-based morphometry revealed decreased GM volume in anterior medio-temporal regions including amygdala in patients compared to controls. During fMRI, we presented dynamic facial expressions (fear and chewing) and their spatiotemporally scrambled versions. We found enhanced activation for fearful compared to neutral faces in ventral temporal cortex and superior temporal sulcus in controls, but not in patients. In the bvFTD group left amygdalar GM volume correlated positively with emotion-related activity in left fusiform face area (FFA). This correlation was amygdala-specific and driven by GM in superficial and basolateral (BLA) subnuclei, consistent with reported amygdalar-cortical networks. The data suggests that anterior medio-temporal atrophy in bvFTD affects emotion processing in distant posterior areas. PMID:27389802

  6. Gait patterns in children with Developmental Coordination Disorder.

    PubMed

    Wilmut, K; Du, W; Barnett, A L

    2016-06-01

    Previous research has shown that adults with Developmental Coordination Disorder (DCD) show increased variability of foot placement measures and movement of the centre of mass (CoM) while walking. The current study considered the gait patterns of young and older children with DCD. Fourteen young children with DCD (7-12 years), 15 older children with DCD (12-17 years) and 29 age- and gender-matched typically developing children took part. Children were asked to walk up and down a flat 10-m-long pathway for 1 min, while the movement of their feet and trunk was recorded using motion analysis. The gait pattern of children with DCD was characterised by wider steps, elevated variability in the time spent in double support and stride time and greater medio-lateral velocity and acceleration compared to their peers. An elevated variability in medio-lateral acceleration was also seen in the young but not the older children with DCD. In addition, the young children showed a greater variability in velocity and acceleration in all three directions compared to the older children. The data suggest that the high incidence of trips and falls seen in children with DCD may be due to differences in the control of the CoM. PMID:26879769

  7. Effect of gait retraining for reducing ambulatory knee load on trunk biomechanics and trunk muscle activity.

    PubMed

    Nüesch, Corina; Laffer, Dominik; Netzer, Cordula; Pagenstert, Geert; Mündermann, Annegret

    2016-06-01

    The purpose of this study was to test the hypothesis that walking with increased medio-lateral trunk sway is associated with lower external knee adduction moment and lower extremity muscle activation, and higher external ipsilateral trunk moment and trunk muscle activity than walking with normal trunk sway in healthy participants. Fifteen participants performed walking trials with normal and increased medio-lateral trunk sway. Maximum trunk sway, first maximum knee adduction moment, lateral trunk bending moment, and bilateral vastus medialis, vastus lateralis, gluteus medius, rectus abdominis, external oblique and erector spinae muscle activity were computed. Walking with increased trunk sway was associated with lower maximum knee adduction moment (95% confidence interval (CI): 0.50-0.62Nm/kg vs. 0.62-0.76Nm/kg; P<.001) and ipsilateral gluteus medius (-17%; P=.014) and erector spinae muscle activity (-24%; P=.004) and greater maximum lateral trunk bending moment (+34%; P<.001) and contralateral external oblique muscle activity (+60%; P=.009). In all participants, maximum knee adduction moment was negatively correlated and maximum trunk moment was positively correlated with maximum trunk sway. The results of this study suggest that walking with increased trunk sway not only reduces the external knee adduction moment but also alters and possibly increases the load on the trunk. Hence, load-altering biomechanical interventions should always be evaluated not only regarding their effects on the index joint but on other load-bearing joints such as the spine. PMID:27264398

  8. Observatorio Astronómico De Cantabria

    NASA Astrophysics Data System (ADS)

    Domínguez, R. M.; Carrera, F. J.

    The Astronomical Observatory of Cantabria is a center of the Consejería de Medio Ambiente del Gobierno de Cantabria managed by the Centro de Investigación del Medio Ambiente (CIMA), an autonomous organism which depends on such Consejería. The development of different activities of the Observatory is a joint collaboration between the University of Cantabria and the Agrupación Astronómica Cántabra (AstroCantabria). As part of the University of Cantabria, the Instituto de Física de Cantabria (IFCA, CSIC-UC) is in charge of the direction, management and coordination of scientific, observational, educational and outreach activities of the Observatory. AstroCantabria takes care of the outreach activities for the general public as well as the astronomical observations. In addition, it is responsible for the calibration and maintenance of the astronomical instrumentation of the Observatory. The Astronomical Observatory of Cantabria is located on the Southern edge of the Comunidad Autónoma de Cantabria, on the high plateau of La Lora (Valderredible county), at an altitude of 1,080m, with longitude 3∘ 56 ' 36' W and latitude 42∘ 46 ' 18' N. Rocamundo is the closest town. The Observatory aims to become a center of reference for scientific, observational, educational and public outreach activities in Cantabria. In the near future, an observational proposal system for outside users will be set in place.

  9. Validation of a method for real time foot position and orientation tracking with Microsoft Kinect technology for use in virtual reality and treadmill based gait training programs.

    PubMed

    Paolini, Gabriele; Peruzzi, Agnese; Mirelman, Anat; Cereatti, Andrea; Gaukrodger, Stephen; Hausdorff, Jeffrey M; Della Croce, Ugo

    2014-09-01

    The use of virtual reality for the provision of motor-cognitive gait training has been shown to be effective for a variety of patient populations. The interaction between the user and the virtual environment is achieved by tracking the motion of the body parts and replicating it in the virtual environment in real time. In this paper, we present the validation of a novel method for tracking foot position and orientation in real time, based on the Microsoft Kinect technology, to be used for gait training combined with virtual reality. The validation of the motion tracking method was performed by comparing the tracking performance of the new system against a stereo-photogrammetric system used as gold standard. Foot position errors were in the order of a few millimeters (average RMSD from 4.9 to 12.1 mm in the medio-lateral and vertical directions, from 19.4 to 26.5 mm in the anterior-posterior direction); the foot orientation errors were also small (average %RMSD from 5.6% to 8.8% in the medio-lateral and vertical directions, from 15.5% to 18.6% in the anterior-posterior direction). The results suggest that the proposed method can be effectively used to track feet motion in virtual reality and treadmill-based gait training programs. PMID:24122572

  10. Measuring regularity of human postural sway using approximate entropy and sample entropy in patients with Ehlers-Danlos syndrome hypermobility type.

    PubMed

    Rigoldi, Chiara; Cimolin, Veronica; Camerota, Filippo; Celletti, Claudia; Albertini, Giorgio; Mainardi, Luca; Galli, Manuela

    2013-02-01

    Ligament laxity in Ehlers-Danlos syndrome hypermobility type (EDS-HT) patients can influence the intrinsic information about posture and movement and can have a negative effect on the appropriateness of postural reactions. Several measures have been proposed in literature to describe the planar migration of CoP over the base of support, and the most used in clinical field are the CoP excursions in antero-posterior and medio-lateral direction. In recent years a growing number of studies have been designed to explore the complexity of the COP trajectories during quiet standing. We assessed 13 adults with EDS-HT (EDSG) and 20 healthy adults (CG) during static posture, evaluating the CoP using time and frequency domain analysis and entropy analysis (SampEn and ApEn parameters). Higher values of CoP displacements in medio-lateral and anterior-posterior directions for EDSG than CG were found; no differences were observed in CoP frequency. The entropy analysis showed lower value for EDSG than CG, pointing out the needing of EDSG to concentrate more attention on postural control, loosing complexity and reflecting a less automatized postural control. PMID:23246558

  11. Modelling and gait evaluation of asymmetrical-keel foot prosthesis.

    PubMed

    Allard, P; Trudeau, F; Prince, F; Dansereau, J; Labelle, H; Duhaime, M

    1995-01-01

    The paper documents a new concept in prosthetic foot design. It is based on the capacity of a flexible keel to allow a greater medio-lateral function than previously available. The heel has a complex curvature consisting of a medially concave shape that joins the mid-foot. There a hump acting as a leaf-spring ends at the metatarsal break, with an inwardly curved toe extremity. These curvatures contribute to increased medio-lateral control at heel-strike and propulsion for weight transfer and push-off. Results from finite-element modelling indicate that the asymmetrically shaped keel is at least twice as active in storing energy compared with a completely symmetrical one. A preliminary gait study is carried out for a 24-year-old below-knee amputee fitted with the new design, the SPACE foot and a dynamic elastic response foot with a symmetrical keel. With the SPACE foot, there is a 14% increase in walking speed combined with a reduction in the phasic asymmetries. The absolute difference between the initial and terminal double support is 1.4% for the asymmetrical keel design compared with 4.4% for the symmetrical keel foot prosthesis. The peak ankle power generation burst indicates that the SPACE foot behaves as a dynamic elastic response foot. PMID:7616775

  12. The peats of Costa Rica

    SciTech Connect

    Thayer, G.R.

    1991-01-01

    Peat has been identified in Cost Rica, and an economic analysis of energy applications for peat has been done. About 1000 km{sup 2} of Cost Rica has the potential of being covered by peat. The Talamanca Mountains and the northeastern plains contain most of the Costa Rican peat. Specific bogs have been identified by the Medio Queso River in north-central Costa Rica and near El Cairo, Moin, and the Limon airport in northeastern Costa Rica. The Medio Queso bog, which is supplying peat for use as a carrier for nitrogen-fixing bacteria, and the El Cairo bog, which has been identified as a source of horticultural peat for nearby ornamental plant farms, are of special interest. The economics of three energy applications of peat were examined -- as a fuel in large boilers, as a fuel in small boilers, and as an oil substitute in a cement plant. A facility using coal would have the same total costs as one using peat if coal prices were $45 and $30 per metric ton (used for large boilers and a cement plant, respectively). A facility using Bunker C or diesel would have the same total cost as one using peat if oil prices were $0.11, $0.08, and $0.06 per liter (used for large boilers, small boilers, and a cement plant, respectively). In all three cases, the costs for peat were comparable or less than the costs for coal and oil at 1987 prices. 6 refs., 8 figs.

  13. Visual evoked potential guidance for posteroventral pallidotomy in Parkinson's disease.

    PubMed

    Yokoyama, T; Sugiyama, K; Nishizawa, S; Ryu, H; Hinokuma, K; Yamamoto, S; Endoh, M; Ohta, S; Yokota, N; Uemura, K

    1997-03-01

    Visual evoked potentials (VEPs) to photic stimulation of the eyes were used to identify the optic tract and thus determine the location of the globus pallidus internus (GPi) in eight patients with Parkinson's disease who then underwent posteroventral pallidotomy. Distinct waves appeared at 1 or 2 mm below the target (4 to 5 mm below the intercommissural line) and the amplitude significantly increased at 5 or 6 mm below, strongly suggesting that the electrode was in contact with the optic tract. In the medio-lateral direction, potentials were successively recorded in an area of 4 to 8 mm length, indicating the width of the optic tract. The trajectory at the mid point showed the most significant potentials which suggested the center of the optic tract. The site of the first lesion was placed 0 to 2 mm lateral to this trajectory and 5 mm above the point at which the amplitudes of responses increased. The actual lesion site significantly differed from the tentative target in a medio-lateral direction by 1 to 5 mm (mean 3.0 +/- 1.5 mm, n = 6). The Unified Parkinson's Disease Rating Scale score significantly improved and magnetic resonance imaging taken 2 or 3 weeks after the operation showed a lesion within the GPi in each patient. Recording of VEPs greatly facilitates accurate determination of the GPi. PMID:9095626

  14. Changes in initiation of orienting gaze shifts after muscimol inactivation of the caudal fastigial nucleus in the cat.

    PubMed

    Goffart, L; Pélisson, D

    1997-09-15

    1. The production of a goal-directed saccadic gaze shift involves the specification of movement amplitude and direction, and the decision to trigger the movement. Behavioural and neurophysiological data suggest that these two functions involve separate processes which may interact. 2. The medio-posterior cerebellar areas are classically assigned a major contribution to the control of saccade metrics, and previous cerebellar lesion studies have revealed marked dysmetria of visually triggered gaze shifts. In contrast, these studies did not provide evidence for a cerebellar role in saccadic initiation. 3. In the present study, we investigated in the head-unrestrained cat the deficits in both the initiation and the metrics control of saccadic gaze shifts following pharmacological inactivation of the caudal part of the fastigial nucleus (cFN). 4. After cFN inactivation, latencies for contraversive gaze shifts increased to about 137 +/- 28% of normal, and latencies for ipsiversive gaze shifts decreased to about 84 +/- 8% of normal. Similar changes in head movement latency were observed, such that the temporal coupling between eye and head components remained largely unaffected. 5. Contraversive gaze shifts were more hypometric as their latency increased. In contrast, the degree of hypermetria in ipsiversive gaze shifts was unrelated to latency. 6. These results suggest a functional role of the medio-posterior cerebellum in gaze shift initiation and in storing information about the target location and/or the desired gaze shift amplitude. PMID:9379419

  15. NASA Astrophysics Data System (ADS)

    Brunini, A.

    Se presenta una revisión de los conocimientos actuales sobre el proceso de acreción del sistema solar exterior. En base a nuevas y más realistas simulaciones numéricas, se analiza el impacto que tuvo dicho proceso en otras regiones del sistema solar tales como la nube de Oort, el cinturón de Kuiper y el sistema solar interior. Se presentan entonces, las principales limitaciones de los modelos numéricos actuales, los principales puntos aún oscuros en el problema, y algunos de los posibles caminos a seguir para mejorar nuestro conocimiento en el tema. Se discute a continuación la posible utilidad de este tipo de estudios para el diseño de estrategias de búsqueda de otros sistemas planetarios.

  16. DESAFÍOS ÉTICOS DE LA INVESTIGACIÓN CON ANIMALES, MANIPULACIÓN GENÉTICA

    PubMed Central

    Yunta, Eduardo Rodríguez

    2012-01-01

    En la investigación con animales existen cuestionamientos éticos tanto en el uso como modelos de enfermedades humanas y requisito previo para ensayos en humanos como en la introducción de modificaciones genéticas. Algunos de estos cuestionamientos son: no representar exactamente la condición humana como modelos, realizar pruebas de toxicidad con grave daño para los animales, alterar su naturaleza mediante modificaciones genéticas, riesgos de la introducción de organismos genéticamente modificados. El uso de animales en investigación para beneficio humano, impone al ser humano la responsabilidad moral de respetarlo, no haciéndoles sufrir innecesariamente, al estar trabajando con seres vivientes y sentientes. PMID:23338641

  17. LOS COMITÉS DE ÉTICA DE INVESTIGACIÓN BIOMEDICA Y PSICOSOCIAL EN BOLIVIA*

    PubMed Central

    Zwareva Mashiri, Elizabeth C.

    2010-01-01

    Este artículo reporta un estudio realizado en las ciudades de La Paz, Cochabamba, y Santa Cruz en Bolivia. Interesaba saber cuál era la situación de la bioética en Bolivia y cómo se estaba protegiendo a los sujetos de investigación. Luego de revisar algunos conceptos bioéticos, la legislación boliviana y los métodos del estudio, se dan a conocer los resultados del mismo, los cuales revelan gran desconocimiento respecto de cómo proteger los derechos de los sujetos, por la casi ausencia o el inadecuado funcionamiento de los comités de ética de la investigación. PMID:20802822

  18. Probabilidad de colisión de cometas periódicos con partículas interplanetarias

    NASA Astrophysics Data System (ADS)

    Gil Hutton, R.

    Se presentan resultados sobre la probabilidad de colisión de cometas de corto período con la población de partículas interplanetarias presentes en la región del cinturón de asteroides. Se encuentra que este proceso colisional afecta la evolución física de los cometas de manera no despreciable y puede ser el responsable de variaciones de brillo de tipo ``outburst". Se presentan resultados para algunos cometas en particular y se obtiene un límite inferior para el tamaño de los núcleos en función de la distribución de radios del cinturón de asteroides.

  19. Adapting a Common Photographic Camera to Take Pictures of the Sky. (Spanish Title: Adaptando Una Camara Fotografica Comun Para Obtener Fotografias del Cielo.) Adaptando Uma Câmera Fotográfica Manual Simples Para Fotografar o Céu

    NASA Astrophysics Data System (ADS)

    Danhoni Neves, Marcos Cesar; Pereira, Ricardo Francisco

    2007-12-01

    In this paper will be introduced a method of astrophotography using a non-reflex photographic camera (a low-cost method). It will be revised some photographic processes commonly used nowadays for comparison with the aims of this paper. En este trabajo será introducido un método de astrofotografia que utiliza una cámara fotográfica non-reflex (un método de bajo costo). Serán revisados algunos procesos fotográficos comúnmente utilizados actualmente para comparación con los objetivos de este trabajo. O presente artigo procura introduzir um método de astrofotografia utilizando uma câmera fotográfica não reflex, de baixo custo. É feita uma revisão do processo fotográfico comumente empregado para fins de comparação com os objetivos pretendidos no presente trabalho.

  20. Comportamiento dinámico de asteroides en la región 23 < a < 26 UA

    NASA Astrophysics Data System (ADS)

    López García, F.

    Los Kuiper Belt Objects (KBOs) pueden ser una fuente de origen de los cometas de corto período. Muchos de los KBOs observados parecen provenir, al igual que el sistema Pluton-Charonte, de órbitas resonantes con Neptuno. Los Centauros son objetos que dinámicamente provienen de órbitas inestables cuyo semieje mayor se encuentra entre las órbitas de Júpiter y Neptuno. Pudiera ser que estos cuerpos fueron expulsados desde la región del cinturón de Kuiper y se encuentran en un proceso de ``scattering" debido a los efectos gravitacionales de los planetas gigantes. Su tiempo de vida dinámico es de algunos millones de años. La evolución orbital de los objetos trans-Neptunianos nos permite conocer su comportamiento anterior, por eso, es importante su relación dinámica con la evolución orbital de Neptuno. El objeto de este trabajo es estudiar el comportamiento dinámico de partículas test que se encuentran entre las resonancias 3:2 con Neptuno y 2:3 con Urano, las cuales comprenden una región de 2 UA aproximadamente. Los primeros resultados indican que la mayoría de los objetos ficticios son eyectados hacia la parte externa del Sistema Solar, mientras que sólo una parte pequeña del total de objetos estudiados, aproximadamente un 7%, son eyectados hacia la parte interna del Sistema Solar, y en algunos casos sus órbitas pueden cruzar la órbita de los planetas terrestres.

  1. Static and Dynamic Postural Changes after a Mountain Ultra-Marathon of 80 km and 5500 D.

    PubMed

    Marcolin, Giuseppe; Grainer, Alessandro; Reggiani, Carlo; Bisiacchi, Patrizia; Cona, Giorgia; Petrone, Nicola; Paoli, Antonio

    2016-01-01

    The study aimed to investigate the effect of fatigue on static and dynamic postural stability after completing a mountain ultra-marathon. Twelve male athletes participated in the study. Postural stability was assessed before and immediately after the race. Static postural stability was evaluated on a dynamometric platform with eyes opened (OE) and closed (CE). Dynamic postural stability was assessed with OE on an instrumented plate which allowed medio-lateral oscillations. Stabilometric data were affected by fatigue in the OE condition, concerning sway path velocity (p = 0.0006), sway area velocity (p = 0.0006), area of the confidence ellipse (p = 0.0016), maximal anterior-posterior (AP) (p = 0.0017) and medio-lateral (ML) (p = 0.0039) oscillations. In the CE condition the sway path velocity (p = 0.0334), the maximal ML oscillations (p = 0.0161) and the area of the confident ellipse (p = 0.0180) were also negatively influenced. Stabilogram diffusion analysis showed in the OE condition an increase of short-term diffusion coefficients considering the anterior-posterior direction (Dfys; p = 0.0023) and the combination of the two (Dfr2s; p = 0.0032). Equally, long term diffusion coefficients increased considering the anterior-posterior direction (Dfyl; p = 0.0093) and the combination of the two (Dfr2l; p = 0.0086). In CE condition greater values were detected for medio-lateral direction (Dfxl; p = 0.033), anterior-posterior direction (Dfyl; p = 0.0459) and the combination of the two (Dfr2l; p = 0.0048). The dynamic postural stability test showed an increase of the time spent with the edges of the plate on the floor (p = 0.0152). Our results showed that mountain ultra-marathon altered static stability more than dynamic stability. An involvement of cognitive resources to monitor postural stability after fatiguing could be the explanation of the worsening in the automatic task (quiet standing) and of the positive compensation in the less automatic task (dynamic standing

  2. [In Process Citation].

    PubMed

    Daponte Codina, A; Bolivar Muñoz, J; Sánchez-Cantalejo, E; Mateo-Rodríguez, I; Babio, G; Romo-Avilés, N; Rosell-Ortiz, F; Grupo de Estudio de Género Y Enfermedades Cardiovasculares, G

    2016-01-01

     RESUMEN              Fundamento. Identificar factores asociados a la demora prehospitalaria en personas que han tenido un síndrome coronario agudo             Método. Se estudiaron mediante encuesta pacientes ingresados por síndrome coronario agudo en los 33 hospitales públicos andaluces, obteniéndose información sobre diferentes tipos de variables: socio-demográficas, contextuales, clínicas, percepción, actuaciones, y transporte. Se aplicaron modelos de regresión logística multivariante para calcular las odds ratio para la demora.             Resultados. De los 1.416 pacientes en total, más de la mitad tuvieron una demora superior a la hora. Se asocia a la distancia al hospital y al medio de transporte: cuando el evento ocurre en la misma ciudad del hospital, utilizar medios propios aumenta la demora, odds ratio= 1,51 (1,02-2,23);  si la distancia es entre 1-25 kilómetros, no hay una diferencia entre medios propios y ambulancia, odds ratio = 1,41 y odds ratio = 1,43 respectivamente; y cuando supera los25 kilómetros la ambulancia implica mayor demora, odds ratio = 3,13 y odds ratio = 2,20 respectivamente. Además, la sintomatología típica reduce la demora entre los hombres, pero la aumenta entre las mujeres. Asimismo, no darle importancia, esperar a la resolución de los síntomas, buscar atención sanitaria diferente a urgencias hospitalarias o al 061, tener antecedentes, encontrarse fuera de la vivienda habitual, y tener ingresos menores de 1.500 euros aumentan la demora. Tener síntomas respiratorios la reduce.             Conclusiones. La demora prehospitalaria no se ajusta a las recomendaciones sanitarias, asociándose al  entorno físico y social, a factores clínicos, y de percepción y actitudinales de los sujetos.              Palabras clave. Síndrome coronario agudo. Demora prehospitalaria. Género. Servicios de emergencias sanitarias. Desigualdades. PMID:27125609

  3. Static and Dynamic Postural Changes after a Mountain Ultra-Marathon of 80 km and 5500 D+

    PubMed Central

    Marcolin, Giuseppe; Grainer, Alessandro; Reggiani, Carlo; Bisiacchi, Patrizia; Cona, Giorgia; Petrone, Nicola

    2016-01-01

    The study aimed to investigate the effect of fatigue on static and dynamic postural stability after completing a mountain ultra-marathon. Twelve male athletes participated in the study. Postural stability was assessed before and immediately after the race. Static postural stability was evaluated on a dynamometric platform with eyes opened (OE) and closed (CE). Dynamic postural stability was assessed with OE on an instrumented plate which allowed medio-lateral oscillations. Stabilometric data were affected by fatigue in the OE condition, concerning sway path velocity (p = 0.0006), sway area velocity (p = 0.0006), area of the confidence ellipse (p = 0.0016), maximal anterior-posterior (AP) (p = 0.0017) and medio-lateral (ML) (p = 0.0039) oscillations. In the CE condition the sway path velocity (p = 0.0334), the maximal ML oscillations (p = 0.0161) and the area of the confident ellipse (p = 0.0180) were also negatively influenced. Stabilogram diffusion analysis showed in the OE condition an increase of short-term diffusion coefficients considering the anterior-posterior direction (Dfys; p = 0.0023) and the combination of the two (Dfr2s; p = 0.0032). Equally, long term diffusion coefficients increased considering the anterior-posterior direction (Dfyl; p = 0.0093) and the combination of the two (Dfr2l; p = 0.0086). In CE condition greater values were detected for medio-lateral direction (Dfxl; p = 0.033), anterior-posterior direction (Dfyl; p = 0.0459) and the combination of the two (Dfr2l; p = 0.0048). The dynamic postural stability test showed an increase of the time spent with the edges of the plate on the floor (p = 0.0152). Our results showed that mountain ultra-marathon altered static stability more than dynamic stability. An involvement of cognitive resources to monitor postural stability after fatiguing could be the explanation of the worsening in the automatic task (quiet standing) and of the positive compensation in the less automatic task (dynamic standing

  4. A cosmologia no ensino da geografia

    NASA Astrophysics Data System (ADS)

    Santos, S. C.; Chiaradia, A. P. M.

    2003-08-01

    O principal objetivo deste trabalho é auxiliar o professor de Geografia em sala de aula no ensino de tópicos relacionados com a Cosmologia. A idéia deste trabalho surgiu quando foi constatado que o professor de Geografia tem dificuldades de ensinar este tópico. Esta constatação foi feita por uma das autoras ao lecionar este tópico no ensino fundamental e em discussões com outros professores de Geografia. Da mesma maneira que ocorria desde os tempos mais antigos, os alunos têm muito interesse em conhecer os fenômenos que ocorrem no Cosmo, porém os livros didáticos de Geografia utilizados em sala de aula não são ricos em informações sobre este assunto. Assim, o professor de Geografia tem poucas informações para discutir este assunto em sala de aula e não dá a devida importância para este tópico. Então, foi desenvolvido um material de apoio para professores de Geografia sobre a origem do Universo, sua evolução e seu possível futuro evolutivo segundo as mais recentes teorias, com base em perguntas feitas pelos alunos de ensino fundamental e as informações trazidas nos livros didáticos Não cabe a este material inovar e tão pouco trazer uma metodologia de ensino de Cosmologia. Neste material o professor de Geografia pode encontrará um banco de informações, que constitui no estabelecimento de conceitos, teorias e hipóteses, sobre a Cosmologia, em linguagem simples e de fácil entendimento. Para desenvolvê-lo, foram feitas pesquisas não exaustivas em livros e revistas científicas, compilação e discussão em forma cronológica das teorias aceitas sobre modelos cosmológicos. Portanto, este material será apresentado neste trabalho.

  5. What does a comparison of the alcoholic Korsakoff syndrome and thalamic infarction tell us about thalamic amnesia?

    PubMed

    Kopelman, Michael D

    2015-07-01

    In this review, the clinical, neuropsychological, and neuroimaging findings in the alcoholic Korsakoff syndrome and in thalamic amnesia, resulting from focal infarction, are compared. In both disorders, there is controversy over what is the critical site for anterograde amnesia to occur-damage to the anterior thalamus/mammillo-thalamic tract has most commonly been cited, but damage to the medio-dorsal nuclei has also been advocated. Both syndromes show 'core' features of an anterograde amnesic syndrome; but retrograde amnesia is generally much more extensive (going back many years or decades) in the Korsakoff syndrome. Likewise, spontaneous confabulation occurs more commonly in the Korsakoff syndrome, although seen in only a minority of chronic cases. These differences are attributed to the greater prevalence of frontal atrophy and frontal damage in Korsakoff cases. PMID:25218758

  6. Using Schemata for Diagnosis*

    PubMed Central

    Turner, Roy M.

    1988-01-01

    Medical diagnosis is a planning task in which the operators are actions such as asking for information and drawing an inference. Diagnosis involves interleaving planning and plan execution, since information gathered by the diagnostician may change the future course of diagnosis. In this paper we present an approach to computer-based medical diagnosis called schema-based reasoning. This approach represents the reasoner's planning knowledge as packets of procedural information called schemata; each schema can be applied to achieve a goal. Schemata are retrieved using the goals and other features of a consultation. To facilitate opportunism and reactive planning, several schemata can be active at once. The reasoner switches between them as needed, using information about the consultation and using strategies that are represented as strategic schemata. Our approach is implemented in the MEDIO program, a schema-based diagnostic reasoner whose domain is pulmonology.

  7. Mark III Space Suit Mobility: A Reach Evaluation Case Study

    NASA Technical Reports Server (NTRS)

    Thaxton, Sherry S.; Abercromby, Andrew F. J.; Onady, Elizabeth A.; Rajulu, Sudhakar L.

    2007-01-01

    A preliminary assessment of the reach envelope and field of vision (FOV) for a subject wearing a Mark III space suit was requested for use in human-machine interface design of the Science Crew Operations and Utility Testbed (SCOUT) vehicle. The reach and view of two suited and unsuited subjects were evaluated while seated in the vehicle using 3-dimensional position data collected during a series of reaching motions. Data was interpolated and displayed in orthogonal views and cross-sections. Compared with unsuited conditions, medio-lateral reach was not strongly affected by the Mark III suit, whereas vertical and antero-posterior reach were inhibited by the suit. Lateral FOV was reduced by approximately 40 deg. in the suit. The techniques used in this case study may prove useful in human-machine interface design by providing a new means of developing and displaying reach envelopes.

  8. Extrastriate projections in human optic radiation revealed by fMRI-informed tractography.

    PubMed

    Alvarez, Ivan; Schwarzkopf, D Samuel; Clark, Chris A

    2015-09-01

    The human optic radiation (OR) is the main pathway for conveying visual input to occipital cortex, but it is unclear whether it projects beyond primary visual cortex (V1). In this study, we used functional MRI mapping to delineate early visual areas in 30 healthy volunteers and determined the termination area of the OR as reconstructed with diffusion tractography. Direct thalamo-cortical projections to areas V2 and V3 were found in all hemispheres tested, with a distinct anatomical arrangement of superior-inferior fiber placement for dorsal and ventral projections, respectively, and a medio-lateral nesting arrangement for projections to V1, V2 and V3. Finally, segment-specific microstructure was examined, revealing sub-fascicular information. This is to date the first in vivo demonstration of direct extrastriate projections of the OR in humans. PMID:24903826

  9. Fine structure of spermatozoa in the common pandora (Pagellus erythrinus Linnaeus, 1758) (Perciformes, Sparidae).

    PubMed

    Maricchiolo, G; Genovese, L; Laurà, R; Micale, V; Muglia, U

    2004-10-01

    Scanning and transmission electron microscopy were used to investigate the fine structure of the sperm of the Sparid fish Pagellus erythrinus L. The spermatozoon of pandora has a spherical head lacking an acrosome, a cone-shaped midpiece and a long tail. The midpiece houses a single mitochondrion. The centriolar complex lies inside the nuclear fossa and is composed of a proximal and a distal centriole which are arranged at right angles to each other. The flagellum is inserted medio-laterally into the head, contains the conventional 9+2 axoneme and possesses one pair of lateral fins. On the basis of its ultrastructural organization, the pandora sperm can be regarded as an evolved form of the primitive spermatozoon found in Teleosts. According to the morphological classification proposed by Mattei (1970), the sperm of pandora belongs to a "type I" designation, like that of the other Sparid fish. PMID:15375767

  10. Spanish Summary (Nuevos meteoritos encountrados en lmilac)

    NASA Astrophysics Data System (ADS)

    1987-03-01

    Desde tiempos prehistoricos han sido coleccionadas piedras que caen dei cielo. Hasta hace poco eran la unica fuente para hacer estudios de laboratorio de la materia extragal, ktica, e incluso en nuestra era espacial, siguen siendo una valiosa fuente de investigacion de la temprana historia dei sistema solar. Se estima que como termine medio cada kilometro cuadrado de la superficie terrestre es golpeada cada millon de aiios por un meteorito con un pese superior a 500 gramos. La mayoria se pierden en los oceanos 0 caen en regiones con escasa poblacion. Como resultado, los museos en el munda reciben anualmente tan solo alrededor de 6 meteoritos cuya caida fuera atestiguada. Otros llegan por hallazgos casuales que en la mayoria de los casos son meteoritos que han cardo en tiempos prehistoricos.

  11. Comportamiento dinámico de asteroides en la resonancia 2:1

    NASA Astrophysics Data System (ADS)

    López García, F.; Brunini, A.

    El propósito de este trabajo es mostrar los resultados obtenidos del estudio del movimiento de asteroides cercanos a la conmensurabilidad 2:1 con el movimiento medio de Júpiter, analizando el comportamiento de órbitas de asteroides reales y ficticios. Se analizan los tiempos de Lyapunov obtenidos a partir de la integración de las ecuaciones del movimiento. Se han estudiado la órbitas utilizando el modelo de cinco cuerpos y se han considerado los casos planar y espacial. Las simulaciones numéricas se realizaron utilizando integradores simpléticos y el intervalo de tiempo de integración fue de T = 107 años.

  12. Regiones de formación de la línea de He II λ 1640 en una atmósfera en expansión

    NASA Astrophysics Data System (ADS)

    Venero, R.; Cidale, L.; Ringuelet, A.

    Se calculan perfiles de la línea del He II λ1640 empleando un modelo de atmósfera en expansión con una estructura cromosférica para determinar la región de formación de la línea. El problema se trata en geometría esférica, fuera de equilibrio termodinámico. La ecuación de transporte radiativo se resuelve rigurosamente en el marco de referencia del fluído para distintas leyes de velocidad, monótonamente crecientes, y diferentes leyes de temperatura. Se buscan relaciones globales entre las características del perfil y los parámetros físicos atribuídos a la atmósfera estelar, con la finalidad de definir una herramienta de diagnóstico de las propiedades del medio.

  13. Biotelemetry studies on elk

    SciTech Connect

    White, G.C.

    1981-03-01

    The movements of Rocky Mountain elk (Cervus elaphus nelsoni) in the eastern Jemez Mountains in north-central New Mexico were studied from 1978 to 1980. Thirty-six elk were trapped, marked, and released, and 30 of these animals were radio-collared. The June 1977 la Mesa fire created a wintering habit at that was used heavily by the radio-collared elk. The 10-year-old clear cuts on Cerro del Medio on the Baca Land and Cattle Company property were used for calving and nursing areas. In general, radio-collared elk used in an early successional state, and they did not use areas at the Los Alamos National Laboratory where there was human activity.

  14. Una propuesta para el desarrollo de un arreglo de síntesis de apertura

    NASA Astrophysics Data System (ADS)

    Arnal, E. M.

    Los estudios llevados a cabo en la transición del hidrógeno neutro a λ~21-cm han contribuído a incrementar nuestro conocimiento acerca de las propiedades globales del medio interestelar, sea este galáctico o extragaláctico. Avances en este campo han sido provocados, a menudo, por la puesta en servicio de radiotelescopios que poseen una mayor resolución angular. Aquí se presenta una propuesta para desarrollar un nuevo instrumento, un interferómetro, que permitirá abrir nuevas líneas de investigación. Este instrumento combinará la técnica de síntesis de apertura con la de espectroscopía de correlación digital, para alcanzar una resolución angular de 1' y un campo de visión de ~1o.7.

  15. Development and application of a safety assessment methodology for waste disposals

    SciTech Connect

    Little, R.H.; Torres, C.; Schaller, K.H.

    1996-12-31

    As part of a European Commission funded research programme, QuantiSci (formerly the Environmental Division of Intera Information Technologies) and Instituto de Medio Ambiente of the Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (IMA/CIEMAT) have developed and applied a comprehensive, yet practicable, assessment methodology for post-disposal safety assessment of land-based disposal facilities. This Safety Assessment Comparison (SACO) Methodology employs a systematic approach to the collection, evaluation and use of waste and disposal system data. It can be used to assess engineered barrier performance, the attenuating properties of host geological formations, and the long term impacts of a facility on the environment and human health, as well as allowing the comparison of different disposal options for radioactive, mixed and non-radioactive wastes. This paper describes the development of the methodology and illustrates its use.

  16. Poblaciones de los niveles atómicos en condiciones de no equilibrio

    NASA Astrophysics Data System (ADS)

    Cruzado, A.

    El objetivo de este trabajo es encontrar la distribución de los átomos en los diferentes niveles de energía. Con el propósito de encontrar resultados generales y de amplia aplicación, hemos planteado las ecuaciones de equilibrio estadístico como función del número atómico del elemento a considerar y de las condiciones físicas del medio (temperatura y densidad). Así también se ha intentado tener en cuenta todos los niveles atómicos considerando explícitamente aquellos con un número cuántico principal menor que un cierto valor n y calculando una expresión aproximada para estimar la influencia de los demás.

  17. Multi-view score fusion for content-based mammogram retrieval

    NASA Astrophysics Data System (ADS)

    Dhahbi, Sami; Barhoumi, Walid; Zagrouba, Ezzeddine

    2015-12-01

    Screening mammography provides two views for each breast: Medio-Lateral Oblique (MLO) and Cranial-Caudal (CC) views. However, current content based image retrieval (CBIR) systems analyze each view independently, in spite of their complementarities. To further improve the retrieval performance, this paper introduces a two-view CBIR system that combines retrieval results of MLO and CC views. First, we computed the similarity scores between MLO (resp. CC) ROIs in the database and the MLO (resp. CC) query ROI. These ROIs are characterized using curvelet moments. Then, a new linear weighted sum scheme combines MLO and CC scores; it assigns weights for each view according to the distribution of the classes of its neighbors. The ROIs having the highest fused scores are displayed to the radiologist and used to compute the malignancy likelihood of the lesion. Experiments performed on mammograms from the Digital Database for Screening Mammography (DDSM) show the effectiveness of the proposed method.

  18. The replacement of serum by hormones in cell culture media.

    PubMed

    Sato, G; Hayashi, I

    1976-12-01

    The replacement of serum by hormones in cell culture media. (Reemplazo del suero por hormonas en el medio de cultivo de células). Arch. Biol. Med. Exper. 10: 120-121, 1976. The serum used in cell culture media can be replaced by a mixture of hormones and some accesory blood factors. The pituitary cell line GH3 can be grown in a medium in which serum is replaced by triiodothyronine, transferrin, parathormone, tyrotrophin releasing hormone and somatomedins. Hela and BHK cell strains can also be grown in serum free medium supplemented with hormones. Each cell type appears to have different hormonal requirements yet it may found that some hormones are required for most cell types. PMID:1026199

  19. El Planetario Móvil de la Municipalidad de la ciudad de Córdoba

    NASA Astrophysics Data System (ADS)

    Suárez, F. E.; Campos, M.; Goldes, G. V.; Carranza, G. J.; Romero, R.; Juri, H. O.

    Se describen las características y operatoria del nuevo Planetario Móvil. Se trata de un equipamiento de propiedad de la Municipalidad de la Ciudad de Córdoba que es operado por personal y en el predio de la Universidad, en virtud de un convenio suscripto entre ambas instituciones. El planetario consta de una cúpula inflable y de un proyector con programas alternativos que incluyen temas de astronomía, geografía, biología y medio ambiente, entre otros. En la actualidad opera en las instalaciones del Pabellón Argentina de la Ciudad Universitaria y recibe delegaciones escolares de todo el territorio provincial. El Planetario Móvil es parte de un proyecto más amplio de divulgación científica en el cual interactúan la Universidad y el Municipio.

  20. Cerebellar mature teratoma in adulthood.

    PubMed

    Zavanone, M; Alimehmeti, R; Campanella, R; Ram-Pini, P; Locatelli, M; Egidi, M; Righini, A; Bauer, D

    2002-03-01

    Mature teratoma of the posterior cranial fossa in adults is extremely rare. We report a particularly rare case of medio-lateral cerebellar mature teratoma that became symptomatic in a middle-aged man. The CT revealed the lesion of heterogeneous density with calcifications in the solid medial portion. Only the MRI could reliably define the borders of the cystic component extending into the left cerebellar lobe. Histologically the presence of fully matured representative tissues of the 3 germ layers ensured the diagnosis of mature teratoma. We suggest that the cyst formation from progressive latent hemorrhage and/or secretion from the gland cells of the tumor, may be responsible for the clinical decompensation even in adulthood. PMID:12118223

  1. Estimation of potential biomass resource and biogas production from aquatic plants in Argentina

    NASA Astrophysics Data System (ADS)

    Fitzsimons, R. E.; Laurino, C. N.; Vallejos, R. H.

    1982-08-01

    The use of aquatic plants in artificial lakes as a biomass source for biogas and fertilizer production through anaerobic fermentation is evaluated, and the magnitude of this resource and the potential production of biogas and fertilizer are estimated. The specific case considered is the artificial lake that will be created by the construction of Parana Medio Hydroelectric Project on the middle Parana River in Argentina. The growth of the main aquatic plant, water hyacinth, on the middle Parana River has been measured, and its conversion to methane by anaerobic fermentation is determined. It is estimated that gross methane production may be between 1.0-4.1 x 10 to the 9th cu cm/year. The fermentation residue can be used as a soil conditioner, and it is estimated production of the residue may represent between 54,900-221,400 tons of nitrogen/year, a value which is 2-8 times the present nitrogen fertilizer demand in Argentina.

  2. Distribución del continuo ultravioleta e infrarrojo en estrellas Be

    NASA Astrophysics Data System (ADS)

    Cruzado, A.; Ringuelet, A.; di Rocco, H.

    Estamos interesados en interpretar los excesos de flujo infrarrojo y/o ultravioleta observados en estrellas Be con respecto al de estrellas B normales, así como su posible correlación. Una envoltura rodeando la estrella distingue una estrella Be de una B normal; para explicar las observaciones es necesario entonces tener en cuenta todos los posibles procesos físicos que en ella tienen lugar. Adoptando un modelo atmosférico específico, hemos estudiado el proceso de recombinación dielectrónica de metales como MgII y FeII, teniendo en cuenta la posible influencia de la opacidad del medio en el flujo emitido.

  3. Discusión de las aproximaciones utilizadas en el estudio de la recombinación dielectrónica de los metales en envolturas estelares

    NASA Astrophysics Data System (ADS)

    Cruzado, A.; di Rocco, H. O.; Ringuelet, A.

    Se calcularon nuevos parámetros atómicos del MgI reemplazando los niveles de energía teóricos por los observados. Con ellos se calculó nuevamente el flujo originado en la Recombinación Dielectrónica (RD) del MgII y se comparó con resultados anteriores. Se evaluó también la posible influencia de diferentes fuentes de opacidad, en el flujo originado en la RD de los metales en atmósferas extendidas de estrellas tempranas. En particular, se calculó la profundidad óptica de las líneas de MgI para diferentes condiciones físicas del medio.

  4. Three-dimensional cone-beam computed tomography based comparison of condylar position and morphology according to the vertical skeletal pattern

    PubMed Central

    Park, In-Young; Kim, Ji-Hyun

    2015-01-01

    Objective To compare condylar position and morphology among different vertical skeletal patterns. Methods Diagnostic cone-beam computed tomography images of 60 adult patients (120 temporomandibular joints) who visited the orthodontic clinic of Hallym University Sacred Heart Hospital were reviewed. The subjects were divided into three equal groups according to the mandibular plane angle: hypodivergent, normodivergent, and hyperdivergent groups. Morphology of the condyle and mandibular fossa and condylar position were compared among the groups. Results The hypodivergent and hyperdivergent groups showed significant differences in superior joint spaces, antero-posterior condyle width, medio-lateral condyle width, condyle head angle, and condylar shapes. Conclusions Condylar position and morphology vary according to vertical facial morphology. This relationship should be considered for predicting and establishing a proper treatment plan for temporomandibular diseases during orthodontic treatment. PMID:25798412

  5. Late Miocene ignimbrites at the southern Puna-northern Sierras Pampeanas border (˜27°S): Stratigraphic correlation

    NASA Astrophysics Data System (ADS)

    Montero-López, Carolina; Guzmán, Silvina; Barrios, Fabiola

    2015-10-01

    New field observations and petrographic and geochemical data of pyroclastic deposits exposed along the Las Papas valley (border between southern Puna and northern Sierras Pampeanas, Argentina) and further north, lead us to propose a new stratigraphic correlation and classification of the late Miocene volcanism in this area. We redefine the Las Papas, Las Juntas, Aguada Alumbrera and Rosada ignimbrites and define the Agua Caliente and Del Medio ignimbrites. The whole set of ignimbrites are rhyolites and less frequently dacites of calc-alkaline affinity. In the present contribution we divide ignimbrites into the Agua Negra and Rincón groups, based mainly on their geochemical signature. The Agua Negra Group is formed by the Las Papas and Las Juntas ignimbrites, indurated and welded, lithic-rich, with crystal-poor pumices and crystal-rich matrix. The Rincón Group comprises the Agua Caliente, Aguada Alumbrera, Rosada and Del Medio ignimbrites, with variable welding degrees, lithic and crystal content. The greater enrichment of crystals in the matrix in comparison with the crystal content in pumices indicates significant elutriation during flow transport and thus volume estimations are to be considered lower bounds for the actual erupted volume. The total minimum estimated volume for the ignimbrites of the Agua Negra and Rincón groups is 2.8 km3 (2.3 km3 DRE). Field relationships and new analytical data indicate that the different acid ignimbrites that crop out in this small area are related to at least two different magma chambers. The widespread Quaternary volcanism in this area covers the older deposits, thus making it difficult to recognize the volcanic centers that produced these late Miocene ignimbrites.

  6. The influence of cage positioning and cage type on cage migration and fusion rates in patients with monosegmental posterior lumbar interbody fusion and posterior fixation

    PubMed Central

    Abbushi, Alexander; Čabraja, Mario; Thomale, Ulrich-Wilhelm; Woiciechowsky, Christian

    2009-01-01

    In posterior lumbar interbody fusion, cage migrations and lower fusion rates compared to autologous bone graft used in the anterior lumbar interbody fusion procedure are documented. Anatomical and biomechanical data have shown that the cage positioning and cage type seem to play an important role. Therefore, the aim of the present study was to evaluate the impact of cage positioning and cage type on cage migration and fusion. We created a grid system for the endplates to analyze different cage positions. To analyze the influence of the cage type, we compared “closed” box titanium cages with “open” box titanium cages. This study included 40 patients with 80 implanted cages. After pedicle screw fixation, 23 patients were treated with a “closed box” cage and 17 patients with an “open box” cage. The follow-up period averaged 25 months. Twenty cages (25%) showed a migration into one vertebral endplate of <3 mm and four cages (5%) showed a migration of ≥3 mm. Cage migration was highest in the medio-medial position (84.6%), followed by the postero-lateral (42.9%), and the postero-medial (16%) cage position. Closed box cages had a significantly higher migration rate than open box cages, but fusion rates did not differ. In conclusion, cage positioning and cage type influence cage migration. The medio-medial cage position showed the highest migration rate. Regarding the cage type, open box cages seem to be associated with lower migration rates compared to closed box cages. However, the cage type did not influence bone fusion. PMID:19475436

  7. Robust estimation of mammographic breast density: a patient-based approach

    NASA Astrophysics Data System (ADS)

    Heese, Harald S.; Erhard, Klaus; Gooßen, Andre; Bulow, Thomas

    2012-02-01

    Breast density has become an established risk indicator for developing breast cancer. Current clinical practice reflects this by grading mammograms patient-wise as entirely fat, scattered fibroglandular, heterogeneously dense, or extremely dense based on visual perception. Existing (semi-) automated methods work on a per-image basis and mimic clinical practice by calculating an area fraction of fibroglandular tissue (mammographic percent density). We suggest a method that follows clinical practice more strictly by segmenting the fibroglandular tissue portion directly from the joint data of all four available mammographic views (cranio-caudal and medio-lateral oblique, left and right), and by subsequently calculating a consistently patient-based mammographic percent density estimate. In particular, each mammographic view is first processed separately to determine a region of interest (ROI) for segmentation into fibroglandular and adipose tissue. ROI determination includes breast outline detection via edge-based methods, peripheral tissue suppression via geometric breast height modeling, and - for medio-lateral oblique views only - pectoral muscle outline detection based on optimizing a three-parameter analytic curve with respect to local appearance. Intensity harmonization based on separately acquired calibration data is performed with respect to compression height and tube voltage to facilitate joint segmentation of available mammographic views. A Gaussian mixture model (GMM) on the joint histogram data with a posteriori calibration guided plausibility correction is finally employed for tissue separation. The proposed method was tested on patient data from 82 subjects. Results show excellent correlation (r = 0.86) to radiologist's grading with deviations ranging between -28%, (q = 0.025) and +16%, (q = 0.975).

  8. Effect of THIP and SL 76002, two clinically experimented GABA-mimetic compounds, on anterior pituitary GABA receptors and prolactin secretion in the rat

    SciTech Connect

    Apud, J.A.; Masotto, C.; Racagni, G.

    1987-03-02

    In the present study, the ability of three direct GABA agonists, muscimol, THIP and SL 76002 to displace /sup 3/H-GABA binding from anterior pituitary and medio-basal hypothalamus membranes was evaluated. Further, the effect of both THIP and SL 76002 on baseline prolactin levels or after stimulation of hormone release with haloperidol has been also studied. Either muscimol, THIP or SL 76002 have shown to posses 7-, 7- and 3-fold higher affinity, respectively, for the central nervous system than for the anterior pituitary /sup 3/H-GABA binding sites. Moreover, THIP and SL 76002 have demonstrated to be respectively, 25- and 1000- fold less potent than muscimol in inhibiting /sup 3/H- GABA binding at the level of the anterior pituitary and about 25- and 2700-fold less potent at the level of the medio-basal hypothalamus. Under basal conditions, either THIP or SL 76002 were ineffective to reduce prolactin release. However, after stimulation of prolactin secretion through blockade of the dopaminergic neurotransmission with haloperidol (0.1 mg/kg), both THIP (10 mg/kg) and SL 76002 (200 mg/kg) significantly counteracted the neuroleptic-induced prolactin rise with a potency which is in line with their ability to inhibit /sup 3/H-GABA binding in the anterior pituitary. The present results indicate that both compounds inhibit prolactin release under specific experimental situations probably through a GABAergic mechanism. In view of the endocrine effects of these GABA-mimetic compounds, the possibility arises for an application of these type of drugs in clinical neuroendocrinology. 35 references, 3 figures, 2 tables.

  9. Accurate stepping on a narrow path: mechanics, EMG, and motor cortex activity in the cat.

    PubMed

    Farrell, Brad J; Bulgakova, Margarita A; Sirota, Mikhail G; Prilutsky, Boris I; Beloozerova, Irina N

    2015-11-01

    How do cats manage to walk so graciously on top of narrow fences or windowsills high above the ground while apparently exerting little effort? In this study we investigated cat full-body mechanics and the activity of limb muscles and motor cortex during walking along a narrow 5-cm path on the ground. We tested the hypotheses that during narrow walking 1) lateral stability would be lower because of the decreased base-of-support area and 2) the motor cortex activity would increase stride-related modulation because of imposed demands on lateral stability and paw placement accuracy. We measured medio-lateral and rostro-caudal dynamic stability derived from the extrapolated center of mass position with respect to the boundaries of the support area. We found that cats were statically stable in the frontal plane during both unconstrained and narrow-path walking. During narrow-path walking, cats walked slightly slower with more adducted limbs, produced smaller lateral forces by hindlimbs, and had elevated muscle activities. Of 174 neurons recorded in cortical layer V, 87% of forelimb-related neurons (from 114) and 90% of hindlimb-related neurons (from 60) had activities during narrow-path walking distinct from unconstrained walking: more often they had a higher mean discharge rate, lower depth of stride-related modulation, and/or longer period of activation during the stride. These activity changes appeared to contribute to control of accurate paw placement in the medio-lateral direction, the width of the stride, rather than to lateral stability control, as the stability demands on narrow-path and unconstrained walking were similar. PMID:26354314

  10. Economic characteristics of the peat deposits of Costa Rica: preliminary study

    SciTech Connect

    Cohen, A.D. Malavassi, L.; Raymond, R. Jr.; Mora, S.; Alverado, A.

    1985-01-01

    Recent field and laboratory studies have established the presence of numerous extensive peat deposits in Costa Rica. Three of these were selected for initial investigation: (1) the cloud-forest histosols of the Talamanca Mountain Range; (2) the Rio Medio Queso flood plain deposits near the northern Costa Rican border; and (3) a tropical jungle swamp deposit on the northeastern coastal plain. In the Talamanca area, 29 samples were collected from eight sites. Due to the high moisture and cool temperatures of the cloud forest, the peats in this area form blanket-like deposits (generally <1 meter thick) over a wide area (>150 km/sup 2/). These peats are all highly decomposed (avg. 28% fiber), high in ash (avg. 21%), and extensively bioturbated. Relative to all other sites visited, these peats are lowest in moisture (avg. 84%), pH (avg. 4.4), fixed carbon (avg. 23%), and sulfur (avg. 0.2%). However, they have the highest bulk densities (avg. 0.22 g/cc), volatile matter contents (avg. 55%), and nitrogen. Their heating value averaged 7700 BTUs/lb., dry. In the Rio Medio Queso area, 28 samples were collected, representing one transect of the 70 km/sup 2/ flood plain. The peats here occurred in several layers (each <1-1/2 meters thick), interfingering with river flood plain sediments. These peats have the highest calorific values (avg. 8000 BTUs/lb., dry), fixed carbon (avg. 30%), and ash (avg. 22%) and have an average pH of 5.4 and a bulk density of 0.20 g/cc. These results represent only the first part of a long-term, extensive survey of Costa Rica's peat resources. However, they suggest that large, economically-significant peat deposits may be present in this country. 5 refs., 8 figs., 4 tabs.

  11. Center of pressure displacements during gait initiation in individuals with obesity

    PubMed Central

    2014-01-01

    Background Obesity is known to affect balance and gait pattern increasing the risk of fall and injury as compared to the lean population. Such risk is particularly high during postural transitions. Gait initiation (GI) is a transient procedure between static upright posture and steady-state locomotion, which includes anticipatory antero-posterior and lateral movements. GI requires propulsion and balance control. The aim of this study was to characterise quantitatively the strategy of obese subjects during GI using parameters obtained by the Center of Pressure (CoP) track. Methods 20 obese individuals and 15 age-matched healthy subjects were tested using a force platform during the initiation trials. CoP plots were divided in different phases, which identified the anticipatory postural adjustments (APA1, APA2) and a movement phase (LOC). Duration, length and velocity of the CoP trace in these phases were calculated and compared. Results and discussion The results show that the main characteristic of GI in obese participants is represented by a higher excursion in medio-lateral direction. This condition lead to longer APA length and duration, which are statistical significant during APA2 when compared to control subjects. We also found longer duration of APA1 and LOC phases. In terms of velocity, most of the phases were characterised by a reduced CoP velocity in antero-posterior direction and faster movement in medio-lateral direction as compared to the control group. Conclusions Our findings provide novel evidence in GI in obese subjects that may serve for developing exercise programs aimed at specifically improving balance in both the antero-posterior and lateral directions. Such programs together with weight management may be beneficial for improving stability during postural transitions and reducing risk of fall in this population. PMID:24885764

  12. Are the mediolateral joint forces in the lower limbs different between scoliotic and healthy subjects during gait?

    PubMed Central

    2015-01-01

    Introduction The quantification of internal joint efforts could be essential in the development of rehabilitation tools for patients with musculo-skeletal pathologies, such as scoliosis. In this context, the aim of this study was to compare the hips joint mediolateral forces during gait, between healthy subjects and adolescents with left lumbar or thoracolumbar scoliosis (AIS), categorized by their Cobb angle (CA). Material and methods Twelve healthy subjects, 12 AIS with CA between 20° and 40° and 16 AIS in pre-operative condition (CA : > 40°) walked at 4 km/h on an instrumented treadmill. The experimental set-up include six infrared cameras allow the computation of the tridimensional (3D) angular displacement and strain gauges located under the motor-driven treadmill allow the computation of ground reaction forces (GRF). The hips joint mediolateral forces were calculated using a 3D inverse dynamic of human body. One-way ANOVA was performed for the maximum, the minimum and the range of medio-lateral forces at each joint of the lower limbs. When appropriate, a Tukey's post hoc was performed to determine the differences. Results The mediolateral forces were significantly lower at the right hip for AIS with CA between 20° and 40° compared to healthy subject. Conclusion The spinal deformation leads to a reduced medio-lateral force at the right hip, which could gradually change the scheme of postural adjustments for AIS during gait. Further research on the quantification of the joint lower limb efforts should include the knee and ankle joints to evaluate the impact of spinal deformation on the lower limb dynamic behaviour in AIS patients. PMID:25810755

  13. Sampling probability distributions of lesions in mammograms

    NASA Astrophysics Data System (ADS)

    Looney, P.; Warren, L. M.; Dance, D. R.; Young, K. C.

    2015-03-01

    One approach to image perception studies in mammography using virtual clinical trials involves the insertion of simulated lesions into normal mammograms. To facilitate this, a method has been developed that allows for sampling of lesion positions across the cranio-caudal and medio-lateral radiographic projections in accordance with measured distributions of real lesion locations. 6825 mammograms from our mammography image database were segmented to find the breast outline. The outlines were averaged and smoothed to produce an average outline for each laterality and radiographic projection. Lesions in 3304 mammograms with malignant findings were mapped on to a standardised breast image corresponding to the average breast outline using piecewise affine transforms. A four dimensional probability distribution function was found from the lesion locations in the cranio-caudal and medio-lateral radiographic projections for calcification and noncalcification lesions. Lesion locations sampled from this probability distribution function were mapped on to individual mammograms using a piecewise affine transform which transforms the average outline to the outline of the breast in the mammogram. The four dimensional probability distribution function was validated by comparing it to the two dimensional distributions found by considering each radiographic projection and laterality independently. The correlation of the location of the lesions sampled from the four dimensional probability distribution function across radiographic projections was shown to match the correlation of the locations of the original mapped lesion locations. The current system has been implemented as a web-service on a server using the Python Django framework. The server performs the sampling, performs the mapping and returns the results in a javascript object notation format.

  14. Mini-mastoidectomía para anastomosis hipogloso-facial con sección parcial del nervio hipogloso

    PubMed Central

    Campero, Álvaro; Ajler, Pablo; Socolovsky, Mariano; Martins, Carolina; Rhoton, Albert

    2012-01-01

    Introducción: La anastomosis hipogloso-facial es la técnica de elección para la reparación de la parálisis facial cuando no se dispone de un cabo proximal sano del nervio facial. La técnica de anastomosis mediante fresado mastoideo y sección parcial del hipogloso minimiza la atrofia lingual sin sacrificar resultados a nivel facial. Método: La porción mastoidea del nervio facial transcurre por la pared anterior de la AM, a un promedio de 18+/-3 mm de profundidad respecto de la pared lateral. Se debe reconocer la cresta supramastoidea, desde la cual se marca una línea vertical paralela al eje mayor de la AM, 1 cm por detrás de la pared posterior del CAE El fresado se comienza desde la línea medio mastoidea hasta la pared posterior del CAE. Una vez encontrado el nervio facial en el tercio medio del canal mastoideo, el mismo es seguido hacia proximal y distal. Resultados: El abordaje descripto permite acceder al nervio facial intratemporal en su porción mastoidea, y efectuar un fresado óseo sin poner en riesgo al nervio o a estructuras vasculares cercanas. Se trata de un procedimiento técnicamente más sencillo que los abordajes amplios habitualmente utilizados al hueso temporal; no obstante su uso debe ser restringido mayormente a la anastomosis hipogloso-facial. Conclusión: Esta es una técnica relativamente sencilla, que puede ser reproducida por cirujanos sin mayor experiencia en el tema, luego de su paso por el laboratorio de anatomía. PMID:23596555

  15. Los manuales de quimica en Espana (1788--1845): Protagonistas, terminologia, clasificaciones y orden pedagogico

    NASA Astrophysics Data System (ADS)

    Munoz Bello, Maria Rosa

    La presente tesis doctoral es una investigacion sobre los manuales de quimica utilizados en Espana de 1788 a 1845. Este trabajo proporciona una perspectiva general de un tema relevante en las ultimas decadas en Historia de la Ciencia, el estudio de los libros de texto. De acuerdo con las ultimas investigaciones realizadas en este terreno, el acto pedagogico es considerado como un proceso creativo, como espacio de encuentro de actores e intereses muy diversos, matizando las ideas defendidas por Thomas S. Kuhn. Recordemos que segun Kuhn, los libros de texto ofrecen una vision consensuada y normalizada del estado de la ciencia de su epoca, por lo que sus autores eliminan deliberadamente toda controversia y presentan asi una imagen distorsionada de la actividad cientifica. En cambio, se ha mostrado, por ejemplo, que en la ensenanza participan no solamente profesores y alumnos sino tambien otros muchos actores y todos ellos no unicamente con intereses puramente pedagogicos sino tambien con diversos intereses politicos y economicos que pueden conocerse a traves del estudio de los manuales. En esta tesis se pretende analizar los manuales de quimica en Espana desde 1788 hasta 1845. Para poder llevar a cabo la investigacion ha sido necesario precisar el objeto de estudio (libro de texto de quimica) durante el periodo estudiado (1788-1845) ya que no es adecuado adoptar la imagen actual de una disciplina que sufrio sustanciales cambios durante la epoca estudiada. Esta investigacion se centra en un momento especialmente importante para la quimica y que algunos historiadores han llegado a considerar "revolucionario". Durante estos anos se produjo un cambio importante en las teorias quimicas sobre la combustion y el concepto de elemento, asi como una reforma terminologica que originaron la aparicion de importantes controversias. Ademas, debido a la relacion de la quimica con otras disciplinas como la historia natural o la fisica ha sido necesario restringir el objeto de estudio

  16. Discussions about the Nature of Science in a Course on the History of Astronomy. (Spanish Title: Discusiones sobre la Naturaleza de la Ciencia en un Curso sobre Historia de la Astronomía.) Discussões sobre a Natureza da Ciência em um Curso sobre a História da Astronomia

    NASA Astrophysics Data System (ADS)

    Pires de Andrade, Victória Flório; L'Astorina, Bruno

    2010-07-01

    There are an increasing number of researches in science education that affirm the importance of discussions on the "nature of science" in basic education level as well as in teacher training. The history of science applied to education is a way to contextualize epistemological discussions, allowing both the understanding of scientific content and learning about science concepts. We present some reasonably consensual definitions on the nature of science that have been widely discussed by the academic community. We show also some episodes in the history of astronomy which can lead to discussions involving some aspects of the nature of science, and how they can do it. Hay un número creciente de investigaciones en la enseñanza de las ciencias que afirman la importancia de debates sobre la "naturaleza de la ciencia" en la educación básica y formación del profesorado. La historia de la ciencia aplicada a la educación es una manera de contextualizar los debates de la epistemología, lo que permite tanto la comprensión de los contenidos científicos como el aprendizaje de conceptos científicos. En esto trabajo, presentamos algunas definiciones bastante consensuales sobre la naturaleza de la ciencia que han sido ampliamente discutidas por la comunidad académica y mostramos cómo algunos episodios en la historia de la astronomía pueden llevar a discusiones sobre algunos aspectos de la naturaleza de la ciencia. Há um número crescente de pesquisas na área de ensino de ciências que afirmam a importância de discussões sobre a "natureza da ciência" na educação básica e na formação de professores. A história da ciência aplicada ao ensino é uma maneira de contextualizar discussões epistemológicas, permitindo tanto a compreensão de conteúdos científicos quanto o aprendizado de noções sobre as ciências. Neste trabalho apresentamos algumas definições razoavelmente consensuais sobre a natureza da ciência que foram amplamente discutidas pela

  17. Órbitas caóticas en satelites galácticos

    NASA Astrophysics Data System (ADS)

    Carpintero, D. D.; Muzzio, J. C.; Vergne, M. M.; Wachlin, F. C.

    En trabajos anteriores investigamos las órbitas de estrellas que forman los satelites galácticos utilizando análisis de frecuencias. Su uso estaba plenamente justificado por su velocidad y la gran información que brinda, amén de haber dado resultados muy concordantes con los exponentes de Liapunov. Sin embargo, más recientemente, encontramos algunos problemas en la utilización del análisis de frecuencias en sistemas de referencia rotantes (como se utilizan para los satélites), por lo que en este trabajo rehicimos nuestras investigaciones previas utilizando exclusivamente exponentes de Liapunov. Algunas conclusiones anteriores se han confirmado, en tanto que otras deben modificarse. Además, los nuevos resultados muestran que las escalas de tiempo de los procesos caóticos en los satélites galácticos son comparables a, o más cortas que, las escalas de tiempo de otros procesos dinámicos característicos de estos objetos.

  18. Aceptabilidad del diagnóstico rápido casero para HIV entre hombres gay y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires.

    PubMed

    Balán, Iván C; Carballo-Diéguez, Alex; Marone, Rubén O; Pando, María A; Barreda, Victoria; Avila, María M

    2011-03-01

    El uso del diagnóstico rápido para HIV en Argentina, así como otros países de Latinoamérica, ha sido limitado hasta el momento. Este trabajo reporta los resultados provenientes de un estudio cualitativo realizado entre hombres gays y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires, Argentina. El objetivo principal del mismo fue conocer las ventajas y desventajas que los hombres G&HSH perciben en relación al diagnóstico rápido casero para HIV. Se realizaron ocho grupos focales con 73 participantes en los cuales se discutió acerca de las ventajas y desventajas del uso de los diagnósticos rápidos. Las respuestas fueron codificadas utilizando un programa para análisis de datos cualitativos (NVivo) y analizadas temáticamente. Los participantes describieron numerosas ventajas sobre el uso del diagnóstico rápido casero, aunque algunos reportaron importantes preocupaciones dentro de las cuales se destaca la posibilidad de impulsos suicidas si alguien recibe un resultado positivo estando solo. En términos generales se observó una gran aceptabilidad para el uso del diagnóstico rápido si el mismo es realizado por personal de salud en lugares acondicionados para este fin. PMID:25284951

  19. Resonances and Tides in Natural Satellites Systems. (Breton Title: Ressonâncias e Marés em Sistemas de Satélites Naturais.) Resonancias y Mareas en Sistemas de Satélites Naturales

    NASA Astrophysics Data System (ADS)

    Callegari, Nelson, Jr.

    2006-12-01

    sica, e não a descrição detalhada dos conceitos aqui discutidos. Describimos en este trabajo algunos aspectos de la dinámica de resonancias de movimientos promedio. Será dado un énfasis mayor al caso de las resonancias entre satélites regulares de los planetas gigantes, aunque también son discutidos brevemente algunos aspectos de la física de resonancias en sistemas panetarios extrasolares. La importancia del estudio de las resonancias en sistemas de satélites es discutida más detalladamente através de ejemplos, mostrando cómo ciertas resonancias y los efectos de disipación por mareas pueden ser la clave de parte de la explicación de algunos fenómenos aún no comprendidos en el Sistema Solar. Entre varios ejemplos se destacan el problema de la superficie remodelada del satélite Enceladus, la existencia de volcanes activos en Io y la posible existencia de un océano subterráneo en Europa. Este trabajo tiene como objetivo la divulgación de algunos tópicos en Mecánica Celeste y Planetología para un público universitario de ciencias exactas, en particular Astronomía y Física, y no la descripción detallada de los conceptos aquí discutidos.

  20. [Not Available].

    PubMed

    Ortega, Rosa M

    2016-01-01

    El artículo de San Mauro y cols. profundiza en un tema de interés prioritario como es el estudio de los hábitos de ingesta de fluidos en personas de cuatro países: España, Portugal, México y Uruguay, para analizar si se cumplen (y si se conocen) las pautas de hidratación marcadas como adecuadas por organismos oficiales y, en concreto, por la EFSA. Es indudable la importancia de una correcta hidratación pues mientras que se puede vivir meses, o años, con una alimentación incorrecta, la deshidratación puede llevar a la muerte en un escaso periodo de tiempo. Por otra parte, un aporte ligeramente insuficiente de fluidos perjudica la salud, capacidad funcional y calidad de vida del individuo, por lo que debe ser evitada. Incluso algunos estudios encuentran hábitos y estilo de vida menos saludables en individuos con menor consumo de fluidos y pautas de hidratación más incorrectas. PMID:27571645

  1. Aceptabilidad del diagnóstico rápido casero para HIV entre hombres gay y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires

    PubMed Central

    Balán, Iván C.; Carballo-Diéguez, Alex; Marone, Rubén O.; Pando, María A.; Barreda, Victoria; Ávila, María M.

    2011-01-01

    Resumen El uso del diagnóstico rápido para HIV en Argentina, así como otros países de Latinoamérica, ha sido limitado hasta el momento. Este trabajo reporta los resultados provenientes de un estudio cualitativo realizado entre hombres gays y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires, Argentina. El objetivo principal del mismo fue conocer las ventajas y desventajas que los hombres G&HSH perciben en relación al diagnóstico rápido casero para HIV. Se realizaron ocho grupos focales con 73 participantes en los cuales se discutió acerca de las ventajas y desventajas del uso de los diagnósticos rápidos. Las respuestas fueron codificadas utilizando un programa para análisis de datos cualitativos (NVivo) y analizadas temáticamente. Los participantes describieron numerosas ventajas sobre el uso del diagnóstico rápido casero, aunque algunos reportaron importantes preocupaciones dentro de las cuales se destaca la posibilidad de impulsos suicidas si alguien recibe un resultado positivo estando solo. En términos generales se observó una gran aceptabilidad para el uso del diagnóstico rápido si el mismo es realizado por personal de salud en lugares acondicionados para este fin. PMID:25284951

  2. La Observación Sistemática de Vecindarios: El caso de Chile y sus perspectivas para Trabajo Social

    PubMed Central

    Sanhueza, Guillermo E.; Delva, Jorge; Andrade, Fernando H.; Grogan-Kaylor, Andrew; Bares, Cristina; Castillo, Marcela

    2012-01-01

    El estudio acerca de las características de los vecindarios y sus efectos sobre las personas ha llegado a ser un área de creciente atención por parte de investigadores de diversas disciplinas en países desarrollados. Aunque actualmente existen diversas metodologías para estudiar efectos del vecindario, una de las más utilizadas es la Observación Sistemática de Vecindarios –Systematic Social Observation SSO, en inglés—porque permite recolectar información acerca de diversas características del entorno físico, social, ambiental y económico de los vecindarios donde se aplica. El objetivo de este artículo es (i) dar a conocer sumariamente algunas investigaciones influyentes sobre efectos del vecindario en Estados Unidos, ii) describir cómo se diseñó e implementó la Observación Sistemática de Vecindarios en la ciudad de Santiago de Chile, iii) señalar algunos facilitadores y obstaculizadores de la implementación del proyecto y, finalmente iv) enunciar posibles contribuciones y limitaciones que esta metodología ofrecería al trabajo social en Chile. PMID:24791060

  3. Los manuales de quimica en Espana (1788--1845): Protagonistas, terminologia, clasificaciones y orden pedagogico

    NASA Astrophysics Data System (ADS)

    Munoz Bello, Maria Rosa

    La presente tesis doctoral es una investigacion sobre los manuales de quimica utilizados en Espana de 1788 a 1845. Este trabajo proporciona una perspectiva general de un tema relevante en las ultimas decadas en Historia de la Ciencia, el estudio de los libros de texto. De acuerdo con las ultimas investigaciones realizadas en este terreno, el acto pedagogico es considerado como un proceso creativo, como espacio de encuentro de actores e intereses muy diversos, matizando las ideas defendidas por Thomas S. Kuhn. Recordemos que segun Kuhn, los libros de texto ofrecen una vision consensuada y normalizada del estado de la ciencia de su epoca, por lo que sus autores eliminan deliberadamente toda controversia y presentan asi una imagen distorsionada de la actividad cientifica. En cambio, se ha mostrado, por ejemplo, que en la ensenanza participan no solamente profesores y alumnos sino tambien otros muchos actores y todos ellos no unicamente con intereses puramente pedagogicos sino tambien con diversos intereses politicos y economicos que pueden conocerse a traves del estudio de los manuales. En esta tesis se pretende analizar los manuales de quimica en Espana desde 1788 hasta 1845. Para poder llevar a cabo la investigacion ha sido necesario precisar el objeto de estudio (libro de texto de quimica) durante el periodo estudiado (1788-1845) ya que no es adecuado adoptar la imagen actual de una disciplina que sufrio sustanciales cambios durante la epoca estudiada. Esta investigacion se centra en un momento especialmente importante para la quimica y que algunos historiadores han llegado a considerar "revolucionario". Durante estos anos se produjo un cambio importante en las teorias quimicas sobre la combustion y el concepto de elemento, asi como una reforma terminologica que originaron la aparicion de importantes controversias. Ademas, debido a la relacion de la quimica con otras disciplinas como la historia natural o la fisica ha sido necesario restringir el objeto de estudio

  4. Predicciones Sísmológicas

    NASA Astrophysics Data System (ADS)

    Briceño Guarape, Luis Alberto

    2004-05-01

    El trabajo prctende orientar las discusiones. reflexiones y posibles investigaciones sobre la predicción sismológica. inicialmente muestra una síntesis teórica del problema de la predicción científica. estableciendo diferencias entre predicción y pronóstico. Los sistemas en las geocicncias esencialmente son no lineales, lo cual requiere en el caso particular, un acercamiento al problema del caos en geofisica y aclaraciones sobre el problema inverso en sismologóa. Cuál es la opinión de los sismólogos internacionales y nacionales sobre la predicción de los terremotos? Dentro de esta discusión se muestran algunos resultados de laboratorio y campo sobre potenciales eléctricos y otros parámetros geofisicos que se vienen logrando en Colombia. Los resultados no se concluyentes aún y por lo tanto las conclusiones son abiertas.

  5. Observaciones de la corona solar interior con un coronógrafo de espejo

    NASA Astrophysics Data System (ADS)

    Stenborg, G.; Schwenn, R.; Francile, C.; Rovira, M.

    El plasma de la corona solar es un buen indicador de las líneas de fuerza del campo magnético. Por lo tanto, el análisis de estructuras coronales cuasiestacionarias en la corona da importante información sobre el campo magnético y la actividad asociada. Se trata de poner límites a los modelos teóricos existentes mediante el estudio de distintas estructuras en la corona interior. En agosto de 1997 comenzó a operar el coronógrafo solar (MICA) en El Leoncito como parte del Observatorio Solar Alemán-Argentino. Desde su instalación obtiene imágenes de la corona solar (1.05 a 2.0 radios solares) en 2 líneas espectrales correspondientes a la emisión de Fe XIV y Fe X. El instrumento puede obtener imágenes cada minuto por lo que es ideal para estudiar procesos rápidos. Presentamos observaciones recientes que muestran la capacidad del coronógrafo así como la evolución de algunos eventos dinámicos observados por MICA.

  6. Dispersión de velocidades en cúmulos de galaxias

    NASA Astrophysics Data System (ADS)

    Muriel, H.; García Lambas, D.; Quintana, H.; Infante, L.

    Se ha estudiado la dinámica de galaxias en cúmulos en base a una muestra de aproximadamente 4000 galaxias con estimas de velocidad radial pertenecientes a 40 cúmulos. Se desarrolló un algoritmo para identificar sub-estructuras del tipo ``grupos de galaxias". Una vez eliminada este tipo de sub-estructura se computaron los perfiles radiales de dispersión de velocidades (VDP) para los 40 cúmulos de galaxias. Dada las características de la muestra, fue posible estimar el VDP hasta grandes distancias del centro del cúmulo llegando en algunos casos hasta 7 Mpc-1. Los resultados indican que el 65% de los cúmulos presentan un VDP plano a grandes radios consistente con el modelo isotermo. Estos resultados son discutidos en el marco de las recientes controversias suscitadas respecto de la dinámica de los cúmulos vía los perfiles de temperaturas de cúmulos derivados de la emisión en rayos-X.

  7. Polvo en la Región de los Troyanos

    NASA Astrophysics Data System (ADS)

    Gilhutton, R.; Brunini, A.; Coldwell, G.

    La posible existencia de un anillo de polvo en la resonancia 1:1 con Júpiter formado por partículas provenientes de colisiones de asteroides fue propuesta por Liou and Zook (Icarus 113, 403, 1995) y estudiada extensamente por Vieira Martins and Gomes (VIII Reunión Regional Latinoamericana de Astronomía, Montevideo,1995). Si bien las partículas quedarían atrapadas sólo por períodos de algunos miles de años, el proceso colisional continuo en el cinturón de asteroides mantendría constante la densidad, presentándose una mayor concentración en la región de los troyanos. En el presente trabajo se presentan resultados preliminares sobre observaciones polarimétricas realizadas desde CASLEO de la región de L5 que confirmarían la existencia y variaciones de densidad en el anillo de polvo.

  8. Grupos españoles de cálculos ab initio de moléculas de interés astrofísico

    NASA Astrophysics Data System (ADS)

    Yáñez, M.

    Pocos campos de la química están tan bien adaptados a la modelización por medio de los métodos teóricos de la Química Cuántica como la Astroquímica y la Química de la Atmósfera, donde las interacciones moleculares son, generalmente, lo suficientemente pequeñas para que el modelo de molécula aislada funcione muy bien. En España son varios los grupos teóricos que dedican su esfuerzo de investigación, o parte de él, al estudio de moléculas o procesos de interés en Astrofísica o en atmósferas planetarias. Presentaremos diferentes ejemplos paradigmáticos de esta actividad en la que se exploran desde aspectos estructurales, hasta aspectos espectroscópicos y dinámicos. Entre los últimos, cabe destacar estudios en los que se demuestra la importancia de procesos a dos estados, prohibidos por espín, en la formación astrofísica de diversos derivados de interés. En el tratamiento espectroscópico se han hecho esfuerzos interesantes, que han aunado teoría y experimento, en el estudio de sistemas relevantes desde el punto de vista atmosférico, como los hidratos de ácido nítrico, o el tratamiento espectroscópico de moléculas no rígidas. No menos interesantes son los estudios de fotoabsorción de radicales o de procesos multifotónicos. Son particularmente abundantes los estudios dedicados a la reactividad específica de sistemas de interés astrofísico o atmosférico, con el objetivo de esclarecer vías de formación de determinados compuestos o de proporcionar mecanismos que permitan identificar las etapas reactivas limitantes de reacciones de interés en esos medios y sobre los que no existía información previa. Así, por ejemplo, se han publicado interesantes estudios sobre la formación o propiedades de compuestos de fósforo, de silico o de azufre o sobre mecanismos de reacción en los que intervienen el ozono, el radical nitrato, el radical OH u otras especies. Finalmente, son también particularmente relevantes los estudios que varios

  9. Cortical and Subcortical Grey and White Matter Atrophy in Myotonic Dystrophies Type 1 and 2 Is Associated with Cognitive Impairment, Depression and Daytime Sleepiness

    PubMed Central

    Prehn, Christian; Krogias, Christos; Schneider, Ruth; Klein, Jan; Gold, Ralf; Lukas, Carsten

    2015-01-01

    Objectives Central nervous system involvement is one important clinical aspect of myotonic dystrophy type 1 and 2 (DM1 and DM2). We assessed CNS involvement DM1 and DM2 by 3T MRI and correlated clinical and neuocognitive symptoms with brain volumetry and voxel-based morphometry (VBM). Methods 12 patients with juvenile or classical DM1 and 16 adult DM2 patients underwent 3T MRI, a thorough neurological and neuropsychological examination and scoring of depression and daytime sleepiness. Volumes of brain, ventricles, cerebellum, brainstem, cervical cord, lesion load and VBM results of the patient groups were compared to 33 matched healthy subjects. Results Clinical symptoms were depression (more pronounced in DM2), excessive daytime sleepiness (more pronounced in DM1), reduced attention and flexibility of thinking, and deficits of short-term memory and visuo-spatial abilities in both patient groups. Both groups showed ventricular enlargement and supratentorial GM and WM atrophy, with prevalence for more GM atrophy and involvement of the motor system in DM1 and more WM reduction and affection of limbic structures in DM2. White matter was reduced in DM1 in the splenium of the corpus callosum and in left-hemispheric WM adjacent to the pre- and post-central gyrus. In DM2, the bilateral cingulate gyrus and subgyral medio-frontal and primary somato-sensory WM was affected. Significant structural-functional correlations of morphological MRI findings (global volumetry and VBM) with clinical findings were found for reduced flexibility of thinking and atrophy of the left secondary visual cortex in DM1 and of distinct subcortical brain structures in DM2. In DM2, depression was associated with brainstem atrophy, Daytime sleepiness correlated with volume decrease in the middle cerebellar peduncles, pons/midbrain and the right medio-frontal cortex. Conclusion GM and WM atrophy was significant in DM1 and DM2. Specific functional-structural associations related morphological changes

  10. Kinematic predictors of single-leg squat performance: a comparison of experienced physiotherapists and student physiotherapists

    PubMed Central

    2012-01-01

    Background The single-leg squat (SLS) is a common test used by clinicians for the musculoskeletal assessment of the lower limb. The aim of the current study was to reveal the kinematic parameters used by experienced and inexperienced clinicians to determine SLS performance and establish reliability of such assessment. Methods Twenty-two healthy, young adults (23.8 ± 3.1 years) performed three SLSs on each leg whilst being videoed. Three-dimensional data for the hip and knee was recorded using a 10-camera optical motion analysis system (Vicon, Oxford, UK). SLS performance was rated from video data using a 10-point ordinal scale by experienced musculoskeletal physiotherapists and student physiotherapists. All ratings were undertaken a second time at least two weeks after the first by the same raters. Stepwise multiple regression analysis was performed to determine kinematic predictors of SLS performance scores and inter- and intra-rater reliability were determined using a two-way mixed model to generate intra-class correlation coefficients (ICC3,1) of consistency. Results One SLS per leg for each participant was used for analysis, providing 44 SLSs in total. Eight experienced physiotherapists and eight physiotherapy students agreed to rate each SLS. Variance in physiotherapist scores was predicted by peak knee flexion, knee medio-lateral displacement, and peak hip adduction (R2 = 0.64, p = 0.01), while variance in student scores was predicted only by peak knee flexion, and knee medio-lateral displacement (R2 = 0.57, p = 0.01). Inter-rater reliability was good for physiotherapists (ICC3,1 = 0.71) and students (ICC3,1 = 0.60), whilst intra-rater reliability was excellent for physiotherapists (ICC3,1 = 0.81) and good for students (ICC3,1 = 0.71). Conclusion Physiotherapists and students are both capable of reliable assessment of SLS performance. Physiotherapist assessments, however, bear stronger relationships to lower limb kinematics and are more sensitive to hip

  11. Insertion of Astronomy as a High School Subject. (Spanish Title: Inserción de Astronomia Como Materia del Ciclo Secundario.) Inserção da Astronomia Como Disciplina Curricular do Ensino Médio

    NASA Astrophysics Data System (ADS)

    Dias, Claudio André C. M.; Santa Rita, Josué R.

    2008-12-01

    Astronomy is considered among the first sciences that man dominated, however, the basic skills for the construction of knowledge, relatively to the contents "Earth and the Universe" are not being developed properly for the majority of students concluding the high school level. The students are concluding this teaching cycle without proper knowledge of several subjects in the area of Astronomy, which are mandatory in the national Curricular National Parameters (PCN). Because of this discrepancy, this work stresses the need of the incorporation of a specific subject of Astronomy in the high school, in order to reduce the gap between what is taught and which should be taught. La Astronomía es considerada una de las primeras ciencias que el hombre dominó. Sin embargo, las habilidades básicas para la construcción del conocimento, relativo al eje temático "Tierra y Universo", no vienen siendo trabajadas adecuadamente con la mayoría de los alumnos que concluyen el ciclo escolar medio. Los alumnos están concluyendo este nivel de enseñanza sin conocimentos de varios temas en el área de Astronomía, que son obligatorios según los Parámetros Curriculares Nacionales (PCN). En virtud de esta discrepancia, este trabajo enfatiza la necesidad de incorporar una disciplina específica de Astronomía em el ciclo medio, em pro de la reducción de las distorsiones entre lo que es enseñado y lo que se debe enseñar. A Astronomia é considerada uma das primeiras ciências que o homem dominou, porém as competências básicas para a construção do conhecimento, relativo ao eixo temático "Terra e Universo", não vêm sendo trabalhadas a contento com a maioria dos alunos que concluem o ensino médio. Os alunos estão concluindo este nível de ensino sem conhecimento de vários temas na área de Astronomia, que são obrigatórios nos Parâmetros Curriculares Nacionais (PCN). Em virtude desta discrepância, este trabalho vem evidenciar a necessidade da incorporação de uma

  12. Kinetics of bipedal locomotion during load carrying in capuchin monkeys.

    PubMed

    Hanna, Jandy B; Schmitt, Daniel; Wright, Kristin; Eshchar, Yonat; Visalberghi, Elisabetta; Fragaszy, Dorothy

    2015-08-01

    Facultative bipedalism during load transport in nonhuman primates has been argued to be an important behavior potentially leading to the evolution of obligate, extended limb bipedalism. Understanding the biomechanics of such behavior may lead to insights about associated morphology, which may translate to interpretation of features in the fossil record. Some populations of bearded capuchin monkeys (Sapajus libidinosus) spontaneously carry heavy loads bipedally during foraging activities. This study provides the first data on all three components of ground reaction force for spontaneous bipedalism during load carriage in a nonhuman primate. Five individual S. libidinosus (mean body mass = 2.4 kg ± 0.96) were videorecorded during bipedalism while carrying a stone (0.93 kg) under natural conditions. A force plate was embedded in the path of the monkeys. Spatiotemporal and force data for all three components of the ground reaction force were recorded for 28 steps. Capuchins exhibited a mean vertical peak force per total weight (Vpk) for the hindlimb of 1.19 (sd = 0.13), consistent with those of unloaded capuchins in the laboratory and for other bipedal primates, including humans. Vertical force records suggest that capuchins, along with most nonhuman primates, maintain a relatively compliant leg during both unloaded and loaded locomotion. Like all other primates, loaded capuchins maintained laterally (outward) directed medio-lateral forces, presumably to stabilize side-to-side movements of the center of mass. Medio-lateral forces suggest that at near-running speeds dynamic stability diminishes the need to generate high lateral forces. Vertical force traces exhibited a measurable impact spike at foot contact in 85% of the steps recorded. An impact spike is common in human walking and running but has not been reported in other bipedal primates. This spike in humans is thought to lead to bone and cartilage damage. The earliest biped may have experienced similar

  13. Calibración del retardo ionosférico en observaciones astrométricas y geodésicas a partir de observaciones GPS

    NASA Astrophysics Data System (ADS)

    Brunini, C.; Kleusberg, A.; Arias, E. F.; de Biasi, M. S.

    Los parámetros astrométricos y geodésicos de precisión se determinan hoy mediante la observación con técnicas espaciales (VLBI, GPS y LSR). Las técnicas VLBI y GPS operan en la banda de microondas y en ella la ionósfera terrestre es dispersiva. Las señales que provienen de las radiofuentes y de los satélites atraviesan la ionósfera, donde el índice de refracción difiere de la unidad en una cantidad que es proporcional a la densidad de electrones libres e inversamente proporcional al cuadrado de la frecuencia de la onda portadora. Actualmente el International GPS Service for Geodynamics (IGS) mantiene operacional una red global integrada por más de 50 estaciones equipadas con receptores GPS de alta performance; las observaciones diarias son accesibles a los usuarios mediante ftp. La posibilidad de utilizar estas observaciones en un monitoreo continuo de la ionósfera fue señalada por diversos autores, razón por la cual en los últimos años se ha invertido un significativo esfuerzo en la producción de mapas ionosféricos regionales y globales. En el presente trabajo se utilizan 28 estaciones cuyas observaciones mapean la mayor parte de la ionósfera global. Los resultados obtenidos demuestran la posibilidad de obtener mapas ionosféricos globales con una resolución de medio día y con una precisión de (1.5 nseg (rms)). Dichos mapas proveen valores medios globales para el intervalo ajustado. Los residuos del ajuste por mínimos cuadrados constituyen una señal a partir de la cual pueden estudiarse mejor las variaciones geográficas de la ionósfera y las componentes estadísticas de su variación temporal.

  14. Implementacion de modulos constructivistas que atiendan "misconceptions" y lagunas conceptuales en temas de la fisica en estudiantes universitarios

    NASA Astrophysics Data System (ADS)

    Santacruz Sarmiento, Neida M.

    Este estudio se enfoco en los "misconception" y lagunas conceptuales en temas fundamentales de Fisica como son Equilibrio Termodinamico y Estatica de fluidos. En primer lugar se trabajo con la identificacion de "misconceptions" y lagunas conceptuales y se analizo en detalle la forma en que los estudiantes construyen sus propias teorias de fenomenos relacionados con los temas. Debido a la complejidad en la que los estudiantes asimilan los conceptos fisicos, se utilizo el metodo de investigacion mixto de tipo secuencial explicativo en dos etapas, una cuantitativa y otra cualitativa. La primera etapa comprendio cuatro fases: (1) Aplicacion de una prueba diagnostica para identificar el conocimiento previo y lagunas conceptuales. (2) Identificacion de "misconceptions" y lagunas del concepto a partir del conocimiento previo. (3) Implementacion de la intervencion por medio de modulos en el topico de Equilibrio Termodinamico y Estatica de Fluidos. (4) Y la realizacion de la pos prueba para analizar el impacto y la efectividad de la intervencion constructivista. En la segunda etapa se utilizo el metodo de investigacion cualitativo, por medio de una entrevista semiestructurada que partio de la elaboracion de un mapa conceptual y se finalizo con un analisis de datos conjuntamente. El desarrollo de este estudio permitio encontrar "misconceptions" y lagunas conceptuales a partir del conocimiento previo de los estudiantes participantes en los temas trabajados, que fueron atendidos en el desarrollo de las distintas actividades inquisitivas que se presentaron en el modulo constructivista. Se encontro marcadas diferencias entre la pre y pos prueba en los temas, esto se debio al requerimiento de habilidades abstractas para el tema de Estatica de Fluidos y al desarrollo intuitivo para el tema de Equilibrio Termodinamico, teniendo mejores respuestas en el segundo. Los participantes demostraron una marcada evolucion y/o cambio en sus estructuras de pensamiento, las pruebas estadisticas

  15. Neocerebellar control of the motor activity: experimental analysis in the rat. Comparative aspects.

    PubMed

    Cicirata, F; Angaut, P; Pantó, M R; Serapide, M F

    1989-01-01

    The results collected by electrical microstimulation of the nucleus lateralis of the cerebellum in anaesthetized rats may be summarized as follows. The stimulations evoked motor effects in head and forelimb principally whereas hindlimb was only occasionally involved. The movements were prevalently segregated to only one joint (simple movements), in a lesser degree they involved two or three segments (complex movements). Simple and complex movements were apparently distributed in the nuclear mass without topographical segregation or preferentiality. The electromyographic records suggest that the neocerebellar movements are of synergistic nature. A somatotopical organization was evidenced within the nucleus lateralis: 3 specific functional regions were identified in the caudorostral nuclear extension. They concern the forelimb (caudally), head (centrally) and hindlimb (rostrally). This somatotopical organization persisted unmodified following elimination of either the cerebral motor cortex alone or in addition to that of the red nucleus. The nuclear subdivisions of the cerebellar nucleus lateralis showed functional differences: (1) the dorsolateral hump of Goodman et al. was principally involved in lip movements; (2) the subnucleus lateralis parvocellularis elicited movements of single vibrissae, neck and medio-distal segments of the forelimb, prevalently; (3) the magnocellular subdivision essentially controlled both limbs with large prevalence for their medio-proximal segments. To identify the functional role of the different descending pathways which relay the neocerebellum to the cord, the motor effects evoked in intact rats were compared with those elicited in rats submitted to cortical ablation and/or to lesion of the red nucleus region. The integrity of the cerebral cortex was essential only for distalmost forelimb motor activities. After lesion of the rubral region (which concomitantly eliminates corticospinal output), the stimulation of the nucleus lateralis

  16. Gas-exchange patterns of Mediterranean fruit fly Pupae (Diptera: Tephritidae): A tool to forecast developmental stage

    SciTech Connect

    Nestel, D.; Nemny-Lavy, E.; Alchanatis, V.

    2007-03-15

    medido en un sistema cerrado de 'flujo a traves del sistema' conectado a un detector infrarrojo de gases. La actividad metabolica de la pupa (emision de CO{sub 2}) fue contrastado al color del ojo de la pupa en desarrollo, que constituye la actual tecnica de determinacion de la edad fisiologica. El color de ojos en pupa fue determinado digitalmente, usando tres variables (Tendencia, Saturacion e Intensidad). Los colores fueron separados utilizando el analisis discriminatorio. Los patrones de emision de CO{sub 2} durante el desarrollo de la pupa sugieren una tendencia de U: una alta actividad metabolica durante la fase inicial de pupacion y transformacion y durante la fase final del adulto. La temperatura de incubacion afecto el tiempo de desarrollo pero no el patron basico de actividad metabolica. La proporcion de emision de CO{sub 2} uno y dos dias antes de la emergencia del adulto fue muy similar para pupas mantenidas en las diversas temperaturas. El color digital del ojo de la pupa se correlaciono significativamente con los patrones de emision de CO{sub 2} detectados a partir de la fase media de la transformacion de larva a adulto. Los resultados soportan la utilizacion de sistemas de intercambio gaseoso como un sistema auxiliar para la determinacion de la edad fisiologica en cria masiva de moscas de la fruta. (author)

  17. Habitus furibundo en el gueto estadounidense1

    PubMed Central

    Bourgois, Philippe; Castrillo, Fernando Montero; Hart, Laurie; Karandinos, George

    2014-01-01

    Resumen Durante cinco años, un torbellino cotidiano de tiroteos, apuñalamientos y asaltos afectó a la venta de drogas al aire libre en el vecindario puertorriqueño de Filadelfia, donde residíamos y conducíamos nuestro trabajo de campo. La industria de los narcóticos ha venido a llenar el vacío que dejó la desindustrialización, convirtiendo al antiguo distrito fabril de la ciudad en un mercado de narcóticos a cielo abierto que emplea en sus niveles más bajos a jóvenes puertorriqueños y cuyos clientes son principalmente heroinómanos blancos de bajos recursos. La capacidad para movilizar la furia asegura el éxito en la economía de las drogas, garantiza protección en las cárceles y le provee un ingreso mínimo a una población de bajos recursos estigmatizada cuyos miembros frecuentemente reciben diagnósticos médicos de discapacidad cognitiva. Muchos residentes buscan alianzas en redes sociales que los comprometen a participar en intercambios solidarios de violencia auxiliar. Una dinámica de acumulación primitiva corporizada mata, hiere, discapacita o encarcela a la mayoría de estos empleados de bajo nivel y a sus clientes. Los inflados márgenes de ganancia alrededor de esta dinámica dependen de la violencia y la coerción. Un habitus furibundo impulsa a los vendedores callejeros a defender violentamente el micro monopolio de poder de sus jefes en la economía subterránea como si fuese un asunto de diversión. Estos miembros de los niveles más bajos de la industria del narcotráfico se apresuran a fraguar transacciones comerciales en ausencia de un marco legal en un ambiente de escasez que sin embargo se ve inundado por enormes flujos de dinero, drogas adictivas y armas automáticas. Tras las drásticas reformas a los programas de seguridad social, la mano izquierda del Estado, en la forma de los servicios sociales, intenta prolongar los subsidios para individuos vulnerables diagnosticándolos como discapacitados cognitivos permanentes

  18. The impact of focal spot size on clinical images

    NASA Astrophysics Data System (ADS)

    Gorham, Sinead M.; Brennan, Patrick C.

    2009-02-01

    The physical assessment of the spatial resolution produced by broad and fine focal spot sizes has been well established. There is however an evident lack of study into the impact of focal spot selection on clinical image quality. While the excessive use of the fine focus has an impact on tube life, the benefit of its use in radiological imaging should be investigated. Cadaver images were produced in order to compare the 0.8mm and 1.8mm focal spot sizes. The range of radiographic projections assessed included the medio-lateral ankle, antero-posterior (AP) knee, AP thoracic spine and horizontal beam lateral (HBL) lumbar spine. Five clinicians analysed the images using a 1 - 4 visual grading analysis score against a reference image to assess the visibility of specific anatomical criteria. A Mann- Whitney U statistical test was employed to assess the results. No significant statistical differences between the scores for the broad and fine focus images were found, although a non-significant higher score in image quality was shown for the fine compared with the broad focus images with large object to detector distance. No difference in image quality was shown for examinations traditionally produced with a fine focus. The study results questions the wide spread usage of fine foci for specific examinations, particularly for extremity examinations. Current practice based on international guidelines can lead to a reduced life and increased cost with little clinical benefit.

  19. Soft tissue balancing in varus total knee arthroplasty: an algorithmic approach.

    PubMed

    Verdonk, Peter C M; Pernin, Jerome; Pinaroli, Alban; Ait Si Selmi, Tarik; Neyret, Philippe

    2009-06-01

    We present an algorithmic release approach to the varus knee, including a novel pie crust release technique of the superficial MCL, in 359 total knee arthroplasty patients and report the clinical and radiological outcome. Medio-lateral stability was evaluated as normal in 97% of group 0 (deep MCL), 95% of group 1 (pie crust superficial MCL) and 83% of group 2 (distal superficial MCL). The mean preoperative hip-knee angle was 174.0, 172.1, and 169.5 and was corrected postoperatively to 179.1, 179.2, and 177.6 for groups 0, 1, and 2, respectively. A satisfactory correction in the coronal plane was achieved in 82.9% of all-comers falling within the 180 degrees +/- 3 degrees interval. An algorithmic release approach can be beneficial for soft tissue balancing. In all patients, the deep medial collateral ligament should be released and otseophytes removed. The novel pie crust technique of the superficial MCL is safe, efficient and reliable, provided a medial release of 6-8 mm or less is required. The release of the superficial MCL on the distal tibia is advocated in severe varus knees. Preoperative coronal alignment is an important predictor for the release technique, but should be combined with other parameters such as reducibility of the deformity and the obtained gap asymmetry. PMID:19290507

  20. A new gnathiid (Crustacea: Isopoda) parasitizing two species of requiem sharks from Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Coetzee, Maryke L; Smit, Nico J; Grutter, Alexandra S; Davies, Angela J

    2008-06-01

    Third-stage juveniles (praniza 3) of Gnathia grandilaris n. sp. were collected from the gill filaments and septa of 5 requiem sharks, including a white tip reef shark, Triaenodon obesus, and 4 grey reef sharks, Carcharhinus amblyrhynchos, at Lizard Island, Great Barrier Reef, Australia, in March 2002. Some juvenile gnathiids were then maintained in fresh sea water until they molted to adults. Adult males appeared 19 days following detachment of juveniles from host fishes, but no juveniles molted successfully into females. The current description is based, therefore, on bright field and scanning electron microscopy observations of adult males and third-stage juveniles. Unique features of the male include the triangular-shaped inferior medio-frontal process, 2 areolae on the dorsal surface of the pylopod, and a slender pleotelson (twice as long as wide) with lateral concavities. The third-stage juvenile has distinctive white pigmentation on the black pereon when alive, while the mandible has 9 triangular backwardly directed teeth. This species has the largest male and third-stage juvenile of any Gnathia spp. from Australia and of any gnathiid isopods associated with elasmobranchs. PMID:18605791

  1. Attentional and sensory contributions to postural sway in children with autism spectrum disorder.

    PubMed

    Stins, John F; Emck, Claudia; de Vries, Else M; Doop, Siebe; Beek, Peter J

    2015-07-01

    Postural control is known to depend on sensory and cognitive factors. Little is known about how children with autism spectrum disorder (ASD) regulate static balance, and to what extent vision and cognition contribute to the regulation of balance in this group. We compared a group of children with mild ASD and a group of age- and gender-matched controls on various postural tasks, standing on a Wii Balance Board. We tested a sensory disturbance (closing the eyes) and a cognitive disturbance (word memorization) on the control of quiet standing. Analysis of center-of-pressure excursions revealed moderate effects of cognitive load, but clear effects of vision. We found a greater destabilizing effect of closing the eyes (greater postural excursions in the medio-lateral direction) for the ASD group than for controls. No group differences were found on word recall and on a standardized balance test (Movement Assessment Battery for Children; M-ABC2). We suggest that the postural effects reflect tighter coupling between vision and motor adjustments in ASD than in controls, which is consistent with recent suggestions of greater reliance on vision in this group. PMID:26028526

  2. Topographic organization in the auditory brainstem of juvenile mice is disrupted in congenital deafness

    PubMed Central

    Leao, Richardson N; Sun, Hong; Svahn, Katarina; Berntson, Amy; Youssoufian, Monique; Paolini, Antonio G; Fyffe, Robert E W; Walmsley, Bruce

    2006-01-01

    There is an orderly topographic arrangement of neurones within auditory brainstem nuclei based on sound frequency. Previous immunolabelling studies in the medial nucleus of the trapezoid body (MNTB) have suggested that there may be gradients of voltage-gated currents underlying this tonotopic arrangement. Here, our electrophysiological and immunolabelling results demonstrate that underlying the tonotopic organization of the MNTB is a combination of medio-lateral gradients of low-and high-threshold potassium currents and hyperpolarization-activated cation currents. Our results also show that the intrinsic membrane properties of MNTB neurones produce a topographic gradient of time delays, which may be relevant to sound localization, following previous demonstrations of the importance of the timing of inhibitory input from the MNTB to the medial superior olive (MSO). Most importantly, we demonstrate that, in the MNTB of congenitally deaf mice, which exhibit no spontaneous auditory nerve activity, the normal tonotopic gradients of neuronal properties are absent. Our results suggest an underlying mechanism for the observed topographic gradient of neuronal firing properties in the MNTB, show that an intrinsic neuronal mechanism is responsible for generating a topographic gradient of time-delays, and provide direct evidence that these gradients rely on spontaneous auditory nerve activity during development. PMID:16373385

  3. Subjective Visual Vertical and Postural Capability in Children Born Prematurely

    PubMed Central

    Bucci, Maria Pia; Wiener-Vacher, Sylvette; Trousson, Clémence; Baud, Olivier; Biran, Valerie

    2015-01-01

    Purpose We compared postural stability and subjective visual vertical performance in a group of very preterm-born children aged 3-4 years and in a group of age-matched full-term children. Materials and Methods A platform (from TechnoConcept) was used to measure postural control in children. Perception of subjective visual vertical was also recorded with posture while the child had to adjust the vertical in the dark or with visual perturbation. Two other conditions (control conditions) were also recorded while the child was on the platform: for a fixation of the vertical bar, and in eyes closed condition. Results Postural performance was poor in preterm-born children compared to that of age-matched full-term children: the surface area, the length in medio-lateral direction and the mean speed of the center of pressure (CoP) were significantly larger in the preterm-born children group (p < 0.04, p < 0.01, and p < 0.04, respectively). Dual task in both groups of children significantly affected postural control. The subjective visual vertical (SVV) values were more variable and less precise in preterm-born children. Discussion-Conclusions We suggest that poor postural control as well as perception of verticality observed in preterm-born children could be due to immaturity of the cortical processes involved in the motor control and in the treatment of perception and orientation of verticality. PMID:25790327

  4. Three-dimensional morphology and strain of the human Achilles free tendon immediately following eccentric heel drop exercise.

    PubMed

    Obst, Steven J; Newsham-West, Richard; Barrett, Rod S

    2015-12-01

    Our understanding of the immediate effects of exercise on Achilles free tendon transverse morphology is limited to single site measurements acquired at rest using 2D ultrasound. The purpose of this study was to provide a detailed 3D description of changes in Achilles free tendon morphology immediately following a single clinical bout of exercise. Freehand 3D ultrasound was used to measure Achilles free tendon length, and regional cross-sectional area (CSA), medio-lateral (ML) diameter and antero-posterior (AP) diameter in healthy young adults (N=14) at rest and during isometric muscle contraction, immediately before and after 3×15 eccentric heel drops. Post-exercise reductions in transverse strain were limited to CSA and AP diameter in the mid-proximal region of the Achilles free tendon during muscle contraction. The change in CSA strain during muscle contraction was significantly correlated to the change in longitudinal strain (r=-0.72) and the change in AP diameter strain (r=0.64). Overall findings suggest the Achilles free tendon experiences a complex change in 3D morphology following eccentric heel drop exercise that manifests under contractile but not rest conditions, is most pronounced in the mid-proximal tendon and is primarily driven by changes in AP diameter strain and not ML diameter strain. PMID:26519510

  5. Analysis of walking variability through simultaneous evaluation of the head, lumbar, and lower-extremity acceleration in healthy youth

    PubMed Central

    Toda, Haruki; Nagano, Akinori; Luo, Zhiwei

    2016-01-01

    [Purpose] The purpose of this study was to clarify whether walking speed affects acceleration variability of the head, lumbar, and lower extremity by simultaneously evaluating of acceleration. [Subjects and Methods] Twenty young individuals recruited from among the staff at Kurashiki Heisei Hospital participated in this study. Eight accelerometers were used to measure the head, lumbar and lower extremity accelerations. The participants were instructed to walk at five walking speeds prescribed by a metronome. Acceleration variability was assessed by a cross-correlation analysis normalized using z-transform in order to evaluate stride-to-stride variability. [Results] Vertical acceleration variability was the smallest in all body parts, and walking speed effect had laterality. Antero-posterior acceleration variability was significantly associated with walking speed at sites other than the head. Medio-lateral acceleration variability of the bilateral hip alone was smaller than the antero-posterior variability. [Conclusion] The findings of this study suggest that the effect of walking speed changes on the stride-to-stride acceleration variability was individual for each body parts, and differs among directions. PMID:27390419

  6. Pre-bomb {Delta}{sup 14}C variability and the Suess Effect in Cariaco Basin Surface Waters as Recorded in Hermatypic Corals

    SciTech Connect

    Guilderson, T; Cole, J; Southon, J

    2004-10-28

    The {Delta}{sup 14}C content of surface waters in and around the Cariaco Basin were reconstructed from {sup 14}C measurements on sub-annually sampled coral skeletal material. During the late 1930s - early 1940s surface waters within and outside of the Cariaco Basin are similar. Within the Cariaco Basin at Islas Tortugas coral {Delta}{sup 14}C averages -51.9 {+-}3.3 {per_thousand}. Corals collected outside of the basin at Boca de Medio and Los Testigos have {Delta}{sup 14}C values of -53.4 {+-} 3.3 {per_thousand} and -54.3 {+-} 2.6 respectively. Additional {sup 14}C analyses on the Isla Tortugas coral document an {approx} 11 {per_thousand} decrease between {approx}1905 (-40.9 {+-}4.5 {per_thousand}) and {approx}1940. The implied Suess Effect trend (-3 {per_thousand}/decade) is nearly as large as that observed in the atmosphere over the same time period. If we assume that there is little to no fossil fuel {sup 14}CO{sub 2} signature in Cariaco surface waters in {approx}1905, the waters have an equivalent reservoir age of {approx}312 years.

  7. Effects of emotional videos on postural control in children.

    PubMed

    Brandão, Arthur de Freitas; Palluel, Estelle; Olivier, Isabelle; Nougier, Vincent

    2016-03-01

    The link between emotions and postural control has been rather unexplored in children. The objective of the present study was to establish whether the projection of pleasant and unpleasant videos with similar arousal would lead to specific postural responses such as postural freezing, aversive or appetitive behaviours as a function of age. We hypothesized that postural sway would similarly increase with the viewing of high arousal videos in children and adults, whatever the emotional context. 40 children participated in the study and were divided into two groups of age: group 7-9 years (n=23; mean age=8 years ± 0.7) and group 10-12 years (n=17; mean age=11 years ± 0.7). 19 adults (mean age=25.8 years ± 4.4) also took part in the experiment. They viewed emotional videos while standing still on a force platform. Centre of foot pressure (CoP) displacements were analysed. Antero-posterior, medio-lateral mean speed and sway path length increased similarly with the viewing of high arousal movies in the younger, older children, and adults. Our findings suggest that the development of postural control is not influenced by the maturation of the emotional processing. PMID:26979902

  8. Total Knee Arthroplasty for Post-Traumatic Proximal Tibial Bone Defect: Three Cases Report

    PubMed Central

    Tigani, D; Dallari, D; Coppola, C; Ben Ayad, R; Sabbioni, G; Fosco, M

    2011-01-01

    Bone stock deficiency in primary as well as in revision total knee arthroplasty (TKA) represents a difficult problem to surgeon with regard to maintaining proper alignment of the implant components and in establishing a stable bone-implant interface. Different surgical procedures are available in these situations, for instances the use of bone cement, prosthetic augments, custom implant, and wire mesh with morsellized bone grafting and structural bone allograft. Structural allograft offers a numerous advantages as easy remodeling and felling cavitary or segmental defects, excellent biocompatibility, bone stock restoration and potential for ligamentous reattachment. In this article we report a short term result of three cases affected by severe segmental medial post/traumatic tibial plateau defect in arthritic knee, for which massive structural allograft reconstruction and primary total knee replacement were carried. The heights of the bone defect were between 27-33 mm and with moderate medio-lateral knee instability. Pre-operative AKS score in three cases was 30, 34 and 51 points consecutively and improved at the last follow-up to 83, 78 and 85 consecutively. No acute or chronic complication was observed. Last radiological exam referred no signs of prosthetic loosening, no secondary resorption of bone graft and well integrated graft to host bone. These results achieved in our similar three cases have confirmed that the structural bone allograft is a successful biological material to restore hemi-condylar segmental tibial bone defect when total knee replacement is indicated. PMID:21584202

  9. Digitalización de diapositivas del Sol en H α

    NASA Astrophysics Data System (ADS)

    Missio, H.; Montenegro, C.; Montenegro, R.

    El objetivo de este trabajo ha sido el de obtener imágenes digitalizadas de las diapositivas tomadas del Sol en luz de hidrógeno de la línea correspondiente a Hα, y de esta manera llegar a convertir las mismas a un archivo digital para poder ser tratadas luego por computadora y poder contabilizar con exactitud, mediante un programa adecuado para tal fin, las zonas activas del Sol en la imagen digitalizada. En principio, para llegar a esto se pensó en la utilización de medios accesibles, y como detector se utilizó un fototransistor ubicado dentro de un soporte rectangular sobre dos ejes de desplazamiento X e Y. Se han obtenido con este procedimiento imágenes de buena calidad, construídas a partir de tres datos digitalizados en cada barrido que aportan la posición X e Y y la intensidad del pixel en ese punto indicada en 255 tonos de grises.

  10. Where have all the flowers gone: deforestation in the Third World

    SciTech Connect

    Not Available

    1981-01-01

    The papers in this issue (and in its companion issue) describe tropical forest destruction and analyze implications at several levels. The contributions are representative of the major regions of the tropical moist forests (TMFs) - Amazonia, Africa, and Indo-Malaysia - and reveal a process whose ramifications will affect all parts and components of the biosphere. The authors and titles of the 13 paprs are: Norman Myers, Deforestation in the Tropics: Who Gains, Who Loses; William M. Denevan, Swiddens and Cattle Versus Forest: The Imminent Demise of the Amazon Rain Forest Reexamined; Stephen G. Bunker, Impact of Deforestation on Peasant Communities in the Medio Amazonas of Brazil; Susanna B. Hecht, Deforestation in the Amazon Basin: Magnitude, Dynamics and Soil-Resource Effects; K. Twum-Barima, Forests of Ghana - A Diminishing Asset; J. Leroy Deval (English abstract), Man and Development in the Forests of Gabon; J. Leroy Deval, L'Homme et Le Developpement de La Foret du Gabon Dans Le Passe; Faustin Legault (English Translation), Reforestation in the Republic of Gabon; Faustin Legault, Le Reboisement en Republique Gabonaise; Peter S. Ashton, Forest Conditions in the Tropics of Asia and the Far East; Gurmit Singh K.S., Destroying Malaysian Forests; Kuswata Kartawinata, Environmental Consequences of Tree Removal from the Forest in Indonesia; and Robert Goodland, Indonesia's Environmental Progress in Economic Development.

  11. An Anthropometric-Based Subject-Specific Finite Element Model of the Human Breast for Predicting Large Deformations

    PubMed Central

    Pianigiani, Silvia; Ruggiero, Leonardo; Innocenti, Bernardo

    2015-01-01

    The large deformation of the human breast threatens proper nodules tracking when the subject mammograms are used as pre-planning data for biopsy. However, techniques capable of accurately supporting the surgeons during biopsy are missing. Finite element (FE) models are at the basis of currently investigated methodologies to track nodules displacement. Nonetheless, the impact of breast material modeling on the mechanical response of its tissues (e.g., tumors) is not clear. This study proposes a subject-specific FE model of the breast, obtained by anthropometric measurements, to predict breast large deformation. A healthy breast subject-specific FE parametric model was developed and validated by Cranio-caudal (CC) and Medio-Lateral Oblique (MLO) mammograms. The model was successively modified, including nodules, and utilized to investigate the effect of nodules size, typology, and material modeling on nodules shift under the effect of CC, MLO, and gravity loads. Results show that a Mooney–Rivlin material model can estimate healthy breast large deformation. For a pathological breast, under CC compression, the nodules displacement is very close to zero when a linear elastic material model is used. Finally, when nodules are modeled, including tumor material properties, under CC, or MLO or gravity loads, nodules shift shows ~15% average relative difference. PMID:26734604

  12. Acidic gases and nitrate and sulfate particles in the atmosphere in the city of Guadalajara, México.

    PubMed

    Saldarriaga-Noreña, Hugo; Waliszewski, Stefan; Murillo-Tovar, Mario; Hernández-Mena, Leonel; de la Garza-Rodríguez, Iliana; Colunga-Urbina, Edith; Cuevas-Ordaz, Rosalva

    2012-05-01

    Atmospheric concentrations of nitrous acid, nitric acid, nitrate and sulfate particles were obtained in this study from April to June 2008 in the center of the city of Guadalajara, while concentrations of ozone, sulfur dioxide, nitrogen dioxide and meteorological parameters (temperature and relative humidity), were acquired by the Secretaría del Medio Ambiente para el Desarrollo Sustentable del Estado de Jalisco (SEMADES). The results showed that nitric acid (2.7 μg m(-3)) was 2.7 times higher than nitrous acid (1.0 μg m(-3)). The sulfur dioxide (SO(2)) concentration indicated an opposite trend to sulfate (SO(4) (2-)), with the average concentration of SO(2) (6.9 μg m(-3)) higher in almost the entire period of study. The sulfur conversion ratio (Fs, 24.9%) and nitrogen conversion ratio (Fn, 6.2%), were revealed to be similar to that reported in other urban areas during warm seasons. It is also noted that ozone is not the main oxidizer of nitrogen dioxide and sulfur dioxide. This determination was made by taking into account the slightly positively correlation determined for Fn (r(2) = 0.084) and Fs (r(2) = 0.092) with ozone that perhaps suggests there are other oxidizing species such as the radical OH, which are playing an important role in the processes of atmospheric oxidation in this area. PMID:22358115

  13. Functional magnetic resonance imaging of the rat cerebellum during electrical stimulation of the fore- and hindpaw at 7 T

    NASA Astrophysics Data System (ADS)

    Peeters, Ronald; Verhoye, Marleen; Vos, Bart; De Schutter, Erik; Van der Linden, Anne-Marie

    1999-05-01

    Blood oxygenation level dependent contrast (BOLD) functional MRI responses at 7T were observed in the cerebellum of alpha- chloralose anesthetized rats in response to innocuous electrical stimulation of a forepaw or hindpaw. The responses were imaged in both coronal and sagittal slices which allowed for a clear delineation and localization of the observed activations. We demonstrate the validity of our fMRI protocol by imaging the responses in somatosensory cortex to the same stimuli and by showing a high level of reproducibility of the cerebellar responses. Widespread bilateral activations were found with mainly a patchy and medio-lateral band organization, more pronounced ipsilaterally. There was no overlap between the cerebellar activations caused by forepaw or hindpaw stimulation. Most remarkable was the overall horizontal organization of these responses: for both stimulation paradigms the patches and bands of activation were roughly positioned in either a cranial or caudal plane running antero-posteriorly through the whole cerebellum. This is the first fMRI study in the cerebellum of the rat. We relate our findings to the known projection patterns found with other techniques and to human fMRI studies. The horizontal organization found wasn't observed before in other studies using other techniques.

  14. Effect of Long-Duration Spaceflight on Postural Control During Self-Generated Perturbations

    NASA Technical Reports Server (NTRS)

    Layne, Charles S.; Mulavera, Ajitkumar P.; McDonald, P. Vernon; Pruett, Casey J.; Kozlovskaya, Innessa B.; Bloomberg, Jacob J.

    2001-01-01

    This report is the first systematic evaluation of the effects of prolonged weightlessness on the bipedal postural control processes during self-generated perturbations produced by voluntary upper limb movements. Spaceflight impacts humans in a variety of ways, one of which is compromised postflight postural control. We examined the neuromuscular activation characteristics and center of pressure motion (COP) associated with arm movement of eight subjects who experienced long duration spaceflight (3-6 months) aboard the Mir space station. Surface electromyography (EMG), arm acceleration, and COP motion were collected while astronauts performed rapid unilateral shoulder flexions prior to and after spaceflight. Subjects displayed compromised postural control after flight as evidenced by modified peak-to-peak COP anterior-posterior and medio-lateral motion and COP pathlength relative to preflight values. These changes were associated with disrupted neuromuscular activation characteristics, particularly after the completion of arm acceleration (i.e. when subjects were attempting to maintain their upright posture). These findings suggest that although the subjects were able to assemble coordination modes that enabled them to generate rapid arm movements, the subtle control necessary to maintain bipedal equilibrium evident in their preflight performance is compromised after long duration spaceflight.

  15. The effect of a long-distance run on plantar pressure distribution during running.

    PubMed

    Willems, Tine Marieke; De Ridder, Roel; Roosen, Philip

    2012-03-01

    The purpose of this study was to assess plantar pressure alterations after long-distance running. Prior to and after a 20 km run, force distribution underneath the feet of 52 participants was registered using Footscan(®) pressure plates while the participants ran shod at a constant self-selected pace. Peak force, mean force and impulse were registered underneath different zones of the foot. In addition, temporal data as total foot contact time, time of contact and end of contact were derived for these zones. Furthermore, a medio-lateral pressure distribution ratio was calculated in different phases of the roll-off. After the run, increases in the loading of the forefoot, midfoot and medial heel were noted and decreases in loading of the lateral toes. In the forefoot push off phase a more lateral pressure distribution was observed. The results of this study demonstrated plantar pressure deviations after long-distance running which could give additional information related to several running injuries. PMID:22153665

  16. The Saint-Georges-sur-Loire olistostrome, a key zone to understand the Gondwana-Armorica boundary in the Variscan belt (Southern Brittany, France)

    NASA Astrophysics Data System (ADS)

    Cartier, Carine; Faure, Michel

    2004-12-01

    In the southern part of the French Armorican massif, the Ligerian domain is located along the boundary between Gondwana and Armorica. Lithological, geochemical and structural data on the Saint-Georges-sur-Loire Unit, which is the northern part of the Ligerian domain, allow us to distinguish two sub-units. A southern sub-unit, formed by various blocks (chert, limestone, sandstone, rhyolite, mafic rocks) of Silurian to Middle Devonian age included as olistoliths in a Middle-Late Devonian terrigeneous matrix, overthrusts a sandstone-pelite northern sub-unit. Both units experienced two deformation events. The first one is a top-to-the-NW thrusting and the second one is a left-lateral wrenching. The Saint-Georges-sur-Loire Unit is an accretionary prism formed during the Late Devonian closure of the Layon rift, coeval with the main phase of the Variscan orogeny. The Layon rift, which according to the mafic olistoliths was partly floored by oceanic crust, appears as a buffer structural zone that accounts for the lack in Central Brittany of any tectonic or sedimentary echo of the closure of the Medio-European Ocean. The tectonic evolution of the Saint-Georges-sur-Loire Unit supports a polyorogenic model for this part of the Variscan Belt.

  17. TECNOLOGÍAS DE INFORMACIÓN Y COMUNICACIÓN PARA LA PREVENCIÓN Y CONTROL DE LA INFECCIÓN POR EL VIH Y OTRAS ITS*

    PubMed Central

    Curioso, Walter H.; Blas, Magaly M.; Kurth, Ann E.; Klausner, Jeffrey D.

    2010-01-01

    Avances tecnológicos innovadores como Internet, computadoras personales de bolsillo, teléfonos celulares y otros equipos son un arsenal en crecimiento en el esfuerzo de impedir y controlar el VIH y otras infecciones de transmisión sexual (ITS). A pesar que existe una diversidad de tecnologías de información y comunicación en diferentes etapas de desarrollo para la prevención del VIH e ITS, la investigación en esta área se encuentra aún en crecimiento, y el impacto en la incidencia de enfermedad, las evaluaciones con diseños rigurosos y los estudios económicos todavía son muy limitados. Sin embargo, algunas de estas evidencias son prometedoras y poseen un gran potencial para su uso en nuestro medio. En este artículo hemos realizado una revisión sistemática de la literatura relacionada con el uso de la tecnología aplicada a la prevención y control del VIH e ITS. De ser usada apropiadamente, esta tecnología podría mejorar la vigilancia del VIH y otras ITS, diagnóstico, notificación de parejas, prevención, manejo clínico, y capacitación de profesionales de la salud. PMID:26339254

  18. Evoked potential mapping of the rostral region by frameless navigation system in Mexican hairless pig.

    PubMed

    Saito, Toshiyuki; Uga, Minako; Tsuzuki, Daisuke; Yokota, Hidenori; Oguro, Keiji; Yamamoto, Tsuyoshi; Dan, Ippeita; Watanabe, Eiju

    2013-01-15

    There is an increasing need for a pig model for use in functional brain studies, but a system for determining precise stereotactic coordinates has yet to be developed. Thus, we devised a frameless navigation system for stereotactic positioning, and measured coordinates for the rostral region and the primary somatosensory cortex in the pig brain. Raw coordinates for somatic evoked potential recordings were obtained by passive optical tracking. The location was registered to a computed tomographic image in reference to four stable skull landmarks: the upper margin of each auditory meatus, the external occipital protuberance, and the point where the interfrontal suture crosses a line drawn between the two supraorbital foramina ("IF" point). The cortical position with the greatest response in evoked potential was mapped -51.0 ± 4.67 mm rostro-caudally, 9.1 ± 1.19 mm medio-laterally, and -8.8 ± 0.48 mm dorso-ventrally (means ± SD; n=3) to the IF point. These results show that frameless registration is useful for coordinate-based evoked-potential mapping of the rostral region of the Mexican hairless pig. PMID:23036661

  19. Quantifying the internal deformation of the rodent spinal cord during acute spinal cord injury - the validation of a method.

    PubMed

    Bhatnagar, Tim; Liu, Jie; Yung, Andrew; Cripton, Peter; Kozlowski, Piotr; Tetzlaff, Wolfram; Oxland, Thomas

    2016-01-01

    Visualization and analysis of the rodent spinal cord subject to experimental spinal cord injury (SCI) has almost completely been limited to naked-eye observations, and a single measure of gross spinal cord motion due to injury. This study introduces a novel method which utilizes MRI to quantify the deformation of the rodent spinal cord due to imposed, clinically-relevant injuries - specifically, cervical contusion and dislocation mechanisms. The image registration methods were developed using the Advanced Normalization Tools package, which incorporate rigid, affine and deformable registration steps. The proposed method is validated against a fiducial-based, 'gold-standard' measure of spinal cord tissue motion. The validation analysis yielded accuracy (and precision) values of 62 μm (49 μm), 73 μm (79 μm) and 112 μm (110 μm), for the medio-lateral, dorso-ventral and cranio-caudal directions, respectively. The internal morphological change of the spinal cord has never before been quantified, experimentally. This study demonstrates the capability of this method and its potential for future application to in vivo rodent models of SCI. PMID:25894327

  20. Radiological study of the knee joint line position measured from the fibular head and proximal tibial landmarks.

    PubMed

    Havet, Eric; Gabrion, Antoine; Leiber-Wackenheim, Frederic; Vernois, Joël; Olory, Bruno; Mertl, Patrice

    2007-06-01

    Restoring the joint line level is one of the surgical challenges during revision of total knee arthroplasty. The position of the tibial surface is commonly estimated by its distance to the apex of fibular head, but no study evaluating this distance accurately has been published yet. The purpose of this work was to study the distance between the knee joint line and the apex of the fibular head and the proximal tibia, particularly the tibial tuberosity. Variability with clinical data and relations with other local measurements have been evaluated on knee radiographs (an antero-posterior view, a medio-lateral view and an anteroposterior full length view) of 100 subjects (125 knees). Results showed no correlation between the joint line-fibular head apex distance and any clinical data of the patients, or any other performed measurements. Relations between tibial measurements and the sexe or the height of the subjects were noted. Besides, the review of the 25 bilateral cases did not show statistically significant side difference but the descriptive analysis showed too large discrepancies for the joint line-fibular head apex distance to be used as a landmark. We conclude that the fibular head apex cannot be used as a morphologic landmark to determine the knee joint line position. Its interest in clinical and surgical practice must be discussed. PMID:17440678

  1. Mindfulness, movement control, and attentional focus strategies: effects of mindfulness on a postural balance task.

    PubMed

    Kee, Ying Hwa; Chatzisarantis, Nikos; Kong, Pui Wah; Chow, Jia Yi; Chen, Lung Hung

    2012-10-01

    We examined whether the momentary induction of state mindfulness benefited subsequent balance performance, taking into consideration the effects of dispositional mindfulness. We also tested whether our mindfulness induction, grounded in sustaining moment-to-moment attention, influenced the attentional focus strategies that were adopted by the participants during the balancing task. Balance performance was ascertained based on approximate entropy (ApEn) of the center of pressure (COP) data. The study involved 32 males (age: M = 22.8, SD = 1.94) who were randomly assigned to the mindfulness or control group. Using difference in pretest to posttest performance based on the medio-lateral movements as the dependent variable, the test for interaction showed that the mindfulness induction was more effective for participants with higher dispositional mindfulness. Participants who underwent mindfulness induction also reported greater use of external focus strategies than those in the control group. Results suggest that momentary mindful attention could benefit balance performance and affect the use of attentional focus strategies during movement control. PMID:23027228

  2. Estimation of ground reaction force and zero moment point on a powered ankle-foot prosthesis.

    PubMed

    Martinez-Villalpando, Ernesto C; Herr, Hugh; Farrell, Matthew

    2007-01-01

    The ground reaction force (GRF) and the zero moment point (ZMP) are important parameters for the advancement of biomimetic control of robotic lower-limb prosthetic devices. In this document a method to estimate GRF and ZMP on a motorized ankle-foot prosthesis (MIT Powered Ankle-Foot Prosthesis) is presented. The method proposed is based on the analysis of data collected from a sensory system embedded in the prosthetic device using a custom designed wearable computing unit. In order to evaluate the performance of the estimation methods described, standing and walking clinical studies were conducted on a transtibial amputee. The results were statistically compared to standard analysis methodologies employed in a gait laboratory. The average RMS error and correlation factor were calculated for all experimental sessions. By using a static analysis procedure, the estimation of the vertical component of GRF had an averaged correlation coefficient higher than 0.94. The estimated ZMP location had a distance error of less than 1 cm, equal to 4% of the anterior-posterior foot length or 12% of the medio-lateral foot width. PMID:18003052

  3. Highly specific role of hypocretin (orexin) neurons: differential activation as a function of diurnal phase, operant reinforcement vs. operant avoidance and light level

    PubMed Central

    McGregor, Ronald; Wu, Ming-Fung; Barber, Grace; Ramanathan, Lalini; Siegel, Jerome M.

    2011-01-01

    Hypocretin (Hcrt) cell loss is responsible for narcolepsy, but Hcrt's role in normal behavior is unclear. We found that Hcrt KO mice were unable to work for food or water reward during the light phase. However, they were unimpaired relative to wild type (WT) mice when working for reward during the dark phase or when working to avoid shock in the light or dark phases. In WT, expression of Fos in Hcrt neurons occurs only in the light phase when working for positive reinforcement. Expression was seen throughout the medio-lateral extent of the Hcrt field. Fos was not expressed when expected or unexpected, unearned rewards were presented, when working to avoid negative reinforcement, or when given or expecting shock, even though these conditions elicit maximal electroencephalographic (EEG) arousal. Fos was not expressed in the light phase when light was removed. This may explain the lack of light induced arousal in narcoleptics and its presence in normal individuals. This is the first demonstration of such specificity of arousal system function and has implications for understanding the motivational and circadian consequences of arousal system dysfunction. The current results also indicate that comparable and complementary specificities must exist in other “arousal” systems. PMID:22031892

  4. An Anthropometric-Based Subject-Specific Finite Element Model of the Human Breast for Predicting Large Deformations.

    PubMed

    Pianigiani, Silvia; Ruggiero, Leonardo; Innocenti, Bernardo

    2015-01-01

    The large deformation of the human breast threatens proper nodules tracking when the subject mammograms are used as pre-planning data for biopsy. However, techniques capable of accurately supporting the surgeons during biopsy are missing. Finite element (FE) models are at the basis of currently investigated methodologies to track nodules displacement. Nonetheless, the impact of breast material modeling on the mechanical response of its tissues (e.g., tumors) is not clear. This study proposes a subject-specific FE model of the breast, obtained by anthropometric measurements, to predict breast large deformation. A healthy breast subject-specific FE parametric model was developed and validated by Cranio-caudal (CC) and Medio-Lateral Oblique (MLO) mammograms. The model was successively modified, including nodules, and utilized to investigate the effect of nodules size, typology, and material modeling on nodules shift under the effect of CC, MLO, and gravity loads. Results show that a Mooney-Rivlin material model can estimate healthy breast large deformation. For a pathological breast, under CC compression, the nodules displacement is very close to zero when a linear elastic material model is used. Finally, when nodules are modeled, including tumor material properties, under CC, or MLO or gravity loads, nodules shift shows ~15% average relative difference. PMID:26734604

  5. Identification of the breast boundary in mammograms using active contour models.

    PubMed

    Ferrari, R J; Rangayyan, R M; Desautels, J E L; Borges, R A; Frère, A F

    2004-03-01

    A method for the identification of the breast boundary in mammograms is presented. The method can be used in the preprocessing stage of a system for computer-aided diagnosis (CAD) of breast cancer and also in the reduction of image file size in picture archiving and communication system applications. The method started with modification of the contrast of the original image. A binarisation procedure was then applied to the image, and the chain-code algorithm was used to find an approximate breast contour. Finally, the identification of the true breast boundary was performed by using the approximate contour as the input to an active contour model algorithm specially tailored for this purpose. After demarcation of the breast boundary, all artifacts outside the breast region were eliminated. The method was applied to 84 medio-lateral oblique mammograms from the Mini-MIAS database. Evaluation of the detected breast boundary was performed based upon the percentage of false-positive and false-negative pixels determined by a quantitative comparison between the contours identified by a radiologist and those identified by the proposed method. The average false positive and false negative rates were 0.41% and 0.58%, respectively. The two radiologists who evaluated the results considered the segmentation results to be acceptable for CAD purposes. PMID:15125150

  6. Effects of running-induced fatigue on plantar pressure distribution in novice runners with different foot types.

    PubMed

    Anbarian, Mehrdad; Esmaeili, Hamed

    2016-07-01

    This study aimed to assess the effects of running-induced fatigue on plantar pressure parameters in novice runners with low and high medial longitudinal arch. Plantar pressure data from 42 novice runners (21 with high, and 21 with low arch) were collected before and after running-induced fatigue protocol during running at 3.3m/s along the Footscan(®) platform. Peak plantar pressure, peak force and force-time integral (impulse) were measured in ten anatomical zones. Relative time for foot roll-over phases and medio-lateral force ratio were calculated before and after the fatigue protocol. After the fatigue protocol, increases in the peak pressure under the first-third metatarsal zones and reduction under the fourth-fifth metatarsal regions were observed in the low arch individuals. In the high arch group, increases in peak pressure under the fourth-fifth metatarsal zones after the running-induced fatigue was observed. It could be concluded that running-induced fatigue had different effects on plantar pressure distribution pattern among novice runners with low and high medial longitudinal foot arch. These findings could provide some information related to several running injuries among individuals with different foot types. PMID:27477708

  7. Atlas de aves: Un metodo para documentar distribucion y seguir poblaciones

    USGS Publications Warehouse

    Robbins, C.S.; Dowell, B.A.; Dawson, D.K.

    1988-01-01

    Los Atlas de Aves son proyectos nacionales o regionalies para trazar en mapas la distribucion en reproduccion de cada especie de ave. Ese procedimiento se esta usando en Europa, Australia, Nueva Zelanda, Norteamerica, y partes de Africa. El tama?o de los cuadrados varia de medio grado de latitud y Iongitud hasta 5 x 5 km. El trabajo de campo de cada proyecto exige aproxlmadamente cinco a?os, pero los aficionados pueden llevar a cabo la mayor parte del trabajo. Es posible almacenar los resultados en un computador personal. Hay muchos beneficios: (I) se presenta la distribucion corriente de las aves de la nacion, del estado, o de la Iocalidad; (2) se desarrolla nueva informacion especialmente sobre especies raras o en peligro; (3) se descubren areas que tienen una avlfauna sobresaliente o habitats raros y ayuda a su proteccion, (4) se documentan cambios de dlstribucion; (5) se pueden usar para documentar cambios de poblacion, especialmente en los tropicos donde otros metodos son mas dificiles de usar porque hay muchas especies y no hay muchos observadores calificados en la identificacion de sonidos de las aves; (6) son proyectos buenos de investigacion para estudiantes graduados; (7) los turistas y los jefes de excursiones de historia natural pueden contribuir con muchas informaciones

  8. The effects of hippotherapy on postural balance and functional ability in children with cerebral palsy

    PubMed Central

    Moraes, Andréa Gomes; Copetti, Fernando; Angelo, Vera Regina; Chiavoloni, Luana Leonardo; David, Ana Cristina

    2016-01-01

    [Purpose] This study evaluated the effects of hippotherapy on seated postural balance, dynamic balance, and functional performance in children with cerebral palsy and compared the effects of 12 and 24 sessions on seated postural balance. [Subjects and Methods] This study included 15 children with cerebral palsy aged between 5 and 10 years. Interventions: A hippotherapy protocol was performed for 30 minutes, twice a week, for 12 weeks. Postural balance in a sitting position was measured using an AMTI AccuSway Plus force platform 1 week before initiating the hippotherapy program and after 12 and 24 weeks. The Berg Balance Scale (BBS) and Pediatric Evaluation of Disability Inventory (PEDI) were used before and after 24 sessions. [Results] Significant differences were observed for center of pressure (COP) variables, including medio-lateral (COPml), anteroposterior displacement (COPap), and velocity of displacement (VelCOP), particularly after 24 sessions. There were also significant differences in BBS scores and PEDI score increases associated with functional skills (self-care, social function, and mobility), caregiver assistance (self-care), social function, and mobility. [Conclusion] Hippotherapy resulted in improvement in postural balance in the sitting position, dynamic balance, and functionality in children with cerebral palsy, an effect particularly significant after 24 hippotherapy sessions.

  9. Automatic determination of the transition between successive control mechanisms in upright stance assessed by modelling of the centre of pressure.

    PubMed

    Rougier, P

    1999-02-01

    A recently introduced concept models the trajectory of the centre of pressure as a fractional Brownian motion and reveals that two successive scaling regimes, acting hypothetically as open and closed loop mechanisms, are implicated in posture control. Objectivity is obviously required in the determination of the transition point, i.e. the point at which an open-loop control mechanism would switch to a closed-loop one, in order to provide reproducibility and automatism in the processing of data. In the method proposed herein, the transition point corresponds to the maximal distance separating a diffusion curve in a double logarithmic plot (mean square distances MSD calculated on each axis versus increasing time intervals Deltat) from a straight line characterising a pure stochastic behaviour. In closed eye conditions, the switch appears medio-laterally in a 0. 26-0.52 s range for Deltat, the corresponding MSD being in the range of 1.86-10.50 mm(2). In the forward-backward direction, the transition is in a 0.28-0.42 s range and the corresponding MSD is between 3.60 and 15.17 mm(2). Finally, these co-ordinates induce scaling exponents over 0.50 for the shortest Deltat, thus suggesting open-loop control, whereas those of longest Deltat, ranged between 0 and 0.20, give evidence of close-loop control. This data is compared to previous data based upon empirical methods. PMID:10455557

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

    USGS Publications Warehouse

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

    1998-01-01

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

  11. Strategies for defending a dribbler: categorisation of three defensive patterns in 1-on-1 basketball.

    PubMed

    Fujii, Keisuke; Yamashita, Daichi; Yoshioka, Shinsuke; Isaka, Tadao; Kouzaki, Motoki

    2014-09-01

    To clarify the defending-dribbler mechanism, the interaction between the dribbler and defender should be investigated. The purposes of this study were to identify variables that explain the outcome (i.e. 'penetrating' and 'guarding') and to understand how defenders stop dribblers by categorising defensive patterns. Ten basketball players participated as 24 dribbler-defender pairs, who played a real-time, 1-on-1 sub-phase of the basketball. The trials were categorised into penetrating trials, where a dribbler invaded the defended area behind the defender, and guarding trials, where the defender stopped the dribbler's advance. Our results demonstrated that defenders in guarding trials initiated their movements earlier and moved quicker than the defenders in penetrating trials. Moreover, linear discriminant analysis revealed that the differences in initiation time and medio-lateral peak velocity between the defenders and dribblers were critical parameters for explaining the difference between penetrating and guarding trials. Lastly, guarding trials were further categorised into three process patterns during 1-on-1 basketball (i.e. 'early initiation' trials, 'quick movement' trials, and 'dribbler's stop' trials). The results suggest that there are three defending strategies and that one strategy would be insufficient to explain the defending-dribbler mechanism, because both players' anticipation and reactive movement must be considered. PMID:25203390

  12. Long-axis rotation: a missing degree of freedom in avian bipedal locomotion.

    PubMed

    Kambic, Robert E; Roberts, Thomas J; Gatesy, Stephen M

    2014-08-01

    Ground-dwelling birds are typically characterized as erect bipeds having hind limbs that operate parasagittally. Consequently, most previous research has emphasized flexion/extension angles and moments as calculated from a lateral perspective. Three-dimensional (3D) motion analyses have documented non-planar limb movements, but the skeletal kinematics underlying changes in foot orientation and transverse position remain unclear. In particular, long-axis rotation of the proximal limb segments is extremely difficult to measure with topical markers. Here, we present six degree of freedom skeletal kinematic data from maneuvering guineafowl acquired by marker-based XROMM (X-ray Reconstruction of Moving Morphology). Translations and rotations of the hips, knees, ankles and pelvis were derived from animated bone models using explicit joint coordinate systems. We distinguished sidesteps, sidestep yaws, crossover yaws, sidestep turns and crossover turns, but birds often performed a sequence of blended partial maneuvers. Long-axis rotation of the femur (up to 38 deg) modulated the foot's transverse position. Long-axis rotation of the tibiotarsus (up to 65 deg) also affected medio-lateral positioning, but primarily served to either re-orient a swing phase foot or yaw the body about a stance phase foot. Tarsometatarsal long-axis rotation was minimal, as was hip, knee and ankle abduction/adduction. Despite having superficially hinge-like joints, birds coordinate substantial long-axis rotations of the hips and knees to execute complex 3D maneuvers while striking a diversity of non-planar poses. PMID:24855675

  13. Postural sway modifications induced by backpack carriage in primary school children: a case study in Italy.

    PubMed

    Pau, Massimiliano; Pau, Marco

    2010-07-01

    The aim of this investigation is to assess modifications in sway parameters introduced by backpack carriage in Italian primary school children (6-10 years old, n = 447). Two 30-s trials (without and with backpack) were performed directly at a school on a regular school day to collect data on sway area, centre of pressure path length and maximum displacement range in antero-posterior and medio-lateral directions. The results show a significant load-induced increase in all sway parameters and the existence of a linear relationship between sway area and backpack weight. Since postural sway represents an effective indicator of balance abilities, the alterations observed suggest that backpack carriage originates balance impairment and thus may increase the risk of unintentional falls in children. STATEMENT OF RELEVANCE: Loss of balance is among the primary causes of unintentional falls and postural sway represents an effective indicator of balance abilities. In this study, sway parameters were assessed in primary school children wearing backpacks. The differences that were observed show that backpack carriage potentially increases the risk of falls. PMID:20582768

  14. La guerra de los Estados Unidos contra la inmigración. Efectos paradójicos1

    PubMed Central

    Massey, Douglas S.; Pren, Karen A.

    2016-01-01

    Resumen A finales de la década de los cincuenta, Estados Unidos permitía la entrada de aproximadamente medio millón de inmigrantes mexicanos al año, de los cuales 450.000 entraban con visados de trabajo temporal y 50.000 llegaban con visados de residentes permanentes. A mediados de los años sesenta, los cambios en la política migratoria de Estados Unidos realizados en nombre de los derechos civiles redujeron drásticamente las oportunidades de entrada legal a Estados Unidos. Se eliminaron los visados de trabajo temporal y se limitaron los visados de residentes a 20.000 por año. Con las oportunidades de entrada legal restringidas, los flujos migratorios ya establecidos simplemente continuaron, fuera de los límites legales, dando comienzo a una inesperada reacción en cadena de eventos que culminaron en una guerra total contra los inmigrantes y el rápido crecimiento -sin precedentes- de población residente no autorizada en Estados Unidos. El presente artículo demuestra que el aumento de inmigración indocumentada en los Estados Unidos y el crecimiento de la población sin papeles son un producto de políticas migratorias y fronterizas mal concebidas. PMID:27076695

  15. [Options for the improvement of communication and self-determination in end-of-life decisions in intensive care units].

    PubMed

    Zubek, László

    2016-04-24

    The end-of-life decision making process normally based on patient autonomy or substituted judgement. If the patient can express his/her wishes, one must take note of his autonomy. If he/she is unable to self-determination, the importance of advanced directives or substituted judgement increases in the field of end-of-life care. The most important target of the efforts is to improve end-of-life care at intensive care units. Based on bioethical studies of the author and international literature this paper analizes the practice of end-of-life care and presents recommendations for lawmakers. The author proposes to divide patients with organ failure into three parts (end-of-life triage). The first part includes definitely salvageable, the second part definitely unsalvageable, and the third part possibly salvageable groups. This classification depends on the development of medical science and the local options of medical treatment. The quality of the decision-making process can be improved, but all participants must participate and medio-legal regulation must be improved. PMID:27084441

  16. Maintenance of postural stability as a function of tilted base of support.

    PubMed

    Dutt-Mazumder, Aviroop; Challis, John; Newell, Karl

    2016-08-01

    The experiment was set-up to investigate the mechanisms of postural control by manipulating the base of support angle, using tilted platform wedges. The primary focus was to analyze the coupling of the motion of the center of mass (CoM) and the center of pressure (CoP), and the motions of the leg joints considered as individual components and synergies. The CoM-CoP coupling (both medio-lateral and anterioposterior) was preserved (∼0°) across all tilted platform angles (35°, 30°, 20°, 10° Down, 0° Flat and 10°, 20°, 25° Up), reflecting an in-phase pattern. There was high coherence (∼1) for CoM-CoP in the lower frequency range, whereas contrarily the hip, knee and ankle pair-wise couplings had values ranging between (0.4 and 0.7) across the different platform angle conditions. These findings are consistent with the view that the local pair-wise coupled variables of Hip, Knee and Ankle motions adaptively self-organized to preserve the CoM-CoP in-phase coupling at equilibrium over the baseline (0° Flat) platform condition and all other tilted platform angles. The findings support the hypothesis of CoM-CoP coupling acting as a collective variable that provides the structural integrity of the system for upright quiet standing across the platform angle conditions. PMID:27155961

  17. Effects of a light touch on fixed or mobile supports on gait parameters in visually restricted young adults.

    PubMed

    Bingenheimer, Katja; Temprado, Jean Jacques; Harnagea, Marta; Bricot, Nicolas; Villani, Patrick; Berton, Eric

    2015-03-01

    We investigated the effects of lightly touching fixed and mobile supports on gait parameters and center of mass oscillations in visually restricted young adults. Fourteen healthy male and female adults of mean=23.6 years (SD=1.6 years). Twelve walking conditions were completed on the GAITRite measurement system, resulting from crossing 3 conditions of visual restriction (no restriction, partial restriction, blindfolded) and 4 conditions of haptic supplementation (no supplementation, with a cane used as "light touch", with a cane sliding on the ground, while touching a soft elastic handrail). Gait speed, stance time, step length and the basis of support were measured. Accelerations of center of mass were also recorded through an accelerometer and the displacements of center of mass were analyzed. Results showed that visual restriction decreased in gait speed, reduced step length, while it increased the base of support and the amplitude of CoM displacements. In the full restriction condition, haptic supplementation provided by the use of the classic cane improved normalized stance time (%). In addition, in the no vision condition, both the classic cane and the soft handrail increased step length and reduced medio-lateral oscillations of the CoM. These results suggest that in visually restricted healthy adults, lightly touching a fixed (soft handrail) or a mobile (classic cane) support contributes to adaptation of gait parameters and postural control during locomotion. PMID:25623038

  18. Agreement between vertical ground reaction force and ground reaction force vector in five common clinical tests.

    PubMed

    Veilleux, L N; Rauch, F; Lemay, M; Ballaz, L

    2012-12-01

    Mechanography is an innovative method to evaluate lower-limb dynamic muscle function. This technique is generally performed on force platforms that measure only the vertical component of ground reaction force (GRF). The underlying assumption is that medio-lateral and antero-posterior forces do not contribute significantly to the GRF in jumping and rising tests. The goal of this study was to establish the validity of this assumption. Fifteen healthy adults (mean age [SD]: 30 [11] years; mean height [SD]: 1.68 [0.12] m; mean body mass: 70 [18] kg) performed three repetitions of five different tests in the following order: multiple two-legged hopping, multiple one-legged hopping, single two-legged jump, heel-rise test and chair-rise test. An excellent agreement was found between peak GRF and peak vertical GRF. In each of the five tests, peak vertical GRF represented more than 99% of peak GRF. Moreover, the limits of agreement ranged between 0.05% (multiple two-legged hopping test) and 0.4% (heel-rise test) of the averaged peak force measurements. Therefore measuring only the vertical component of ground reaction force in healthy participants is appropriate for the five tests used in the present study. PMID:23196264

  19. Balance Dysfunction in Parkinson's Disease: The Role of Posturography in Developing a Rehabilitation Program.

    PubMed

    Ferrazzoli, Davide; Fasano, Alfonso; Maestri, Roberto; Bera, Rossana; Palamara, Grazia; Ghilardi, Maria Felice; Pezzoli, Gianni; Frazzitta, Giuseppe

    2015-01-01

    Balance dysfunction (BD) in Parkinson's disease (PD) is a disabling symptom, difficult to treat and predisposing to falls. The dopaminergic drugs or deep brain stimulation does not always provide significant improvements of BD and rehabilitative approaches have also failed to restore this condition. In this study, we investigated the suitability of quantitative posturographic indicators to early identify patients that could develop disabling BD. Parkinsonian patients not complaining of a subjective BD and controls were tested using a posturographic platform (PP) with open eyes (OE) and performing a simple cognitive task [counting (OEC)]. We found that patients show higher values of total standard deviation (SD) of body sway and along the medio-lateral (ML) axis during OE condition. Furthermore, total and ML SD of body sway during OE condition and total SD of body sway with OEC were higher than controls also in a subgroup of patients with normal Berg Balance Scale. We conclude that BD in Parkinsonian patients can be discovered before its appearance using a PP and that these data may allow developing specific rehabilitative treatment to prevent or delay their onset. PMID:26504611

  20. Relationship between Anthropometric Factors, Gender, and Balance under Unstable Conditions in Young Adults

    PubMed Central

    Greve, Júlia Maria D'Andréa; Cuğ, Mutlu; Dülgeroğlu, Deniz; Brech, Guilherme Carlos; Alonso, Angelica Castilho

    2013-01-01

    The objective of this study was to evaluate the relationship between the anthropometric factors of height, body mass, body mass index and postural balance and to compare the balance indices between genders in the upright standing position, in healthy adult subjects under conditions of instability. Forty individuals were subjected to functional tests of body stability using the Biodex Balance System, and the resulting indices were correlated with body mass, height, and body mass index, and also compared between genders. Body mass was the main anthropometric factor that influenced variations in postural balance, with a high correlation between groups and with all variables. A linear regression analysis showed that body mass associated with BMI explained 66% of the overall stability, and body mass explained 59% of the anteroposterior stability index and 65% of the mediolateral stability index. In the female group, body mass explained 72% of the overall balance, 66% of the anteroposterior, and 76% of the medio-lateral stability index. Increased body mass requires greater movements to maintain postural balance. Height and BMI presented moderate correlations with balance. Women showed less movement than men on the Biodex Balance System. PMID:23509788

  1. Modulation of muscle sympathetic nerve activity by low-frequency physiological activation of the vestibular utricle in awake humans.

    PubMed

    Hammam, Elie; Kwok, Kenny; Macefield, Vaughan G

    2013-09-01

    We recently showed that selective stimulation of one set of otolithic organs-those located in the utricle, sensitive to displacement in the horizontal axis-causes a marked entrainment of skin sympathetic nerve activity (SSNA). Here, we assessed whether muscle sympathetic nerve activity (MSNA) is similarly modulated. MSNA was recorded via tungsten microelectrodes inserted into cutaneous fascicles of the common peroneal nerve in 12 awake subjects, seated (head vertical, eyes closed) on a motorised platform. Slow sinusoidal accelerations-decelerations (±4 mG) were applied in the X (antero-posterior) or Y (medio-lateral) direction at 0.08 Hz. Cross-correlation analysis revealed partial entrainment of MSNA: vestibular modulation was 32 ± 3 % for displacements in the X-axis and 29 ± 3 % in the Y-axis; these were significantly smaller than those evoked in SSNA (97 ± 3 and 91 ± 5 %, respectively). For each sinusoidal cycle, there were two peaks of modulation-one associated with acceleration as the platform moved forward or to the side and one associated with acceleration in the opposite direction. We believe the two peaks reflect inertial displacement of the stereocilia within the utricle during sinusoidal acceleration, which evokes vestibulosympathetic reflexes that are expressed as vestibular modulation of MSNA as well as of SSNA. The smaller vestibular modulation of MSNA can be explained by the dominant modulation of MSNA by the arterial baroreceptors. PMID:23852323

  2. Increased Histone H3 Phosphorylation in Neurons in Specific Brain Structures after Induction of Status Epilepticus in Mice

    PubMed Central

    Mori, Tetsuji; Wakabayashi, Taketoshi; Ogawa, Haruyuki; Hirahara, Yukie; Koike, Taro; Yamada, Hisao

    2013-01-01

    Status epilepticus (SE) induces pathological and morphological changes in the brain. Recently, it has become clear that excessive neuronal excitation, stress and drug abuse induce chromatin remodeling in neurons, thereby altering gene expression. Chromatin remodeling is a key mechanism of epigenetic gene regulation. Histone H3 phosphorylation is frequently used as a marker of chromatin remodeling and is closely related to the upregulation of mRNA transcription. In the present study, we analyzed H3 phosphorylation levels in vivo using immunohistochemistry in the brains of mice with pilocarpine-induced SE. A substantial increase in H3 phosphorylation was detected in neurons in specific brain structures. Increased H3 phosphorylation was dependent on neuronal excitation. In particular, a robust upregulation of H3 phosphorylation was detected in the caudate putamen, and there was a gradient of phosphorylated H3+ (PH3+) neurons along the medio-lateral axis. After unilateral ablation of dopaminergic neurons in the substantia nigra by injection of 6-hydroxydopamine, the distribution of PH3+ neurons changed in the caudate putamen. Moreover, our histological analysis suggested that, in addition to the well-known MSK1 (mitogen and stress-activated kinase)/H3 phosphorylation/c-fos pathway, other signaling pathways were also activated. Together, our findings suggest that a number of genes involved in the pathology of epileptogenesis are upregulated in PH3+ brain regions, and that H3 phosphorylation is a suitable indicator of strong neuronal excitation. PMID:24147063

  3. Cyclists and triathletes have different body positions on the bicycle.

    PubMed

    Bini, Rodrigo Rico; Hume, Patria A; Croft, James

    2014-01-01

    Our study evaluated differences in body position on the bicycle for recreational cyclists, competitive cyclists and triathletes. Thirty-six recreational cyclists, 17 competitive road cyclists and 18 competitive triathletes were assessed for body position on their bicycles on a cycle trainer. Images were taken of cyclists/triathletes in static poses with the crank at the 3 o'clock and 6 o'clock positions. Trunk, pelvis, hip, knee and ankle angles, anterior-posterior and medio-lateral positions of the knees in relation to the pedal axis and frontal projected area were measured using ImageJ. Comparison of body position between groups (recreational, competitive road cyclists and competitive triathletes) was conducted using effects sizes (ES). The greatest differences between groups in the measured variables were observed between the triathletes and the other two groups. Smaller differences were observed between competitive and recreational cyclists. Competitive triathletes had greater body forward projection (10% greater trunk flexion and 66% knee anterior position, ES = 2.5 and 1.2, respectively) and less frontal projected area (17%, ES = 1.3) than competitive road cyclists for body position on the bicycle. Both recreational and competitive cyclists sat on their bicycles with their trunks in a more vertical position compared to triathletes. Guidelines for bicycle configuration for triathletes and road cyclists need to consider the body positions during events. PMID:24444194

  4. Restriction of dopamine signaling to the dorsolateral striatum is sufficient for many cognitive behaviors

    PubMed Central

    Darvas, Martin; Palmiter, Richard D.

    2009-01-01

    The striatum is a vital substrate for performance, procedural memory, and learning. The ventral and medial striatum are thought to be critical for acquisition of tasks while the dorsolateral striatum is important for performance and habitual enactment of skills. Evidence based on cortical, thalamic, and amygdaloid inputs to the striatum suggests a medio-lateral zonation imposed on the classical dorso-ventral distinction. We therefore investigated the functional significance of dopaminergic signaling in cognitive tasks by studying dopamine-deficient (DD) mice and mice with dopamine signaling restored to only the dorsolateral (DL) striatum by viral rescue (vrDD-DL mice). Whereas DD mice failed in all of the tasks examined here, vrDD-DL mice displayed intact discriminatory learning, object recognition, visuospatial learning and spatial memory. Acquisition of operant behavior for food rewards was delayed in vrDD-DL mice and their motivation in a progressive ratio experiments was reduced. Therefore, dopaminergic signaling in the dorsolateral striatum is sufficient for mice to learn several different cognitive tasks although the rate of learning some of them was reduced. These results indicate that dopaminergic signaling in the ventromedial striatum is not absolutely necessary for mastery of these behaviors, but may facilitate them. PMID:19667174

  5. Effect of projective viewpoint in detecting temporal density changes

    NASA Astrophysics Data System (ADS)

    Raundahl, Jakob; Nielsen, Mads; Olsen, Ole F.; Bagger, Yu Z.

    2004-05-01

    An important question in mammographic image analysis is the importance of the projected view of the breast. Can temporal changes in density be detected equally well using either one of the commonly available views Medio-Lateral (ML) and Cranio-Caudal (CC) or a combination of the two? Two sets of mammograms of 50 patients in a double-blind, placebo controlled hormone replacement therapy (HRT) experiment were used. One set of ML and CC view from 1999 and one from 2001. HRT increases density which means that the degree of separation of the populations (one group receiving HRT and the other placebo) can be used as a measure of how much density change information is carried in a particular view or combination of views. Earlier results have shown a high correlation between CC and ML views leading to the conclusion that only one of them is needed for density assessment purposes. A similar high correlation coefficient was observed in this study (0.85), while the correlation between changes was a bit lower (0.71). Using both views to separate the patients receiving hormones from the ones receiving placebo increased the area under corresponding ROC curves from 0.76 +/- 0.04 to 0.79 +/- 0.04.

  6. The Pregnancy Exposome: Multiple Environmental Exposures in the INMA-Sabadell Birth Cohort.

    PubMed

    Robinson, Oliver; Basagaña, Xavier; Agier, Lydiane; de Castro, Montserrat; Hernandez-Ferrer, Carles; Gonzalez, Juan R; Grimalt, Joan O; Nieuwenhuijsen, Mark; Sunyer, Jordi; Slama, Rémy; Vrijheid, Martine

    2015-09-01

    The "exposome" is defined as "the totality of human environmental exposures from conception onward, complementing the genome" and its holistic approach may advance understanding of disease etiology. We aimed to describe the correlation structure of the exposome during pregnancy to better understand the relationships between and within families of exposure and to develop analytical tools appropriate to exposome data. Estimates on 81 environmental exposures of current health concern were obtained for 728 women enrolled in The INMA (INfancia y Medio Ambiente) birth cohort, in Sabadell, Spain, using biomonitoring, geospatial modeling, remote sensors, and questionnaires. Pair-wise Pearson's and polychoric correlations were calculated and principal components were derived. The median absolute correlation across all exposures was 0.06 (5th-95th centiles, 0.01-0.54). There were strong levels of correlation within families of exposure (median = 0.45, 5th-95th centiles, 0.07-0.85). Nine exposures (11%) had a correlation higher than 0.5 with at least one exposure outside their exposure family. Effectively all the variance in the data set (99.5%) was explained by 40 principal components. Future exposome studies should interpret exposure effects in light of their correlations to other exposures. The weak to moderate correlation observed between exposure families will permit adjustment for confounding in future exposome studies. PMID:26168307

  7. High frequency synchrony in the cerebellar cortex during goal directed movements

    PubMed Central

    Groth, Jonathan D.; Sahin, Mesut

    2015-01-01

    The cerebellum is involved in sensory-motor integration and cognitive functions. The origin and function of the field potential oscillations in the cerebellum, especially in the high frequencies, have not been explored sufficiently. The primary objective of this study was to investigate the spatio-temporal characteristics of high frequency field potentials (150–350 Hz) in the cerebellar cortex in a behavioral context. To this end, we recorded from the paramedian lobule in rats using micro electro-corticogram (μ-ECoG) electrode arrays while the animal performed a lever press task using the forelimb. The phase synchrony analysis shows that the high frequency oscillations recorded at multiple points across the paramedian cortex episodically synchronize immediately before and desynchronize during the lever press. The electrode contacts were grouped according to their temporal course of phase synchrony around the time of lever press. Contact groups presented patches with slightly stronger synchrony values in the medio-lateral direction, and did not appear to form parasagittal zones. The size and location of these patches on the cortical surface are in agreement with the sensory evoked granular layer patches originally reported by Welker's lab (Shambes et al., 1978). Spatiotemporal synchrony of high frequency field potentials has not been reported at such large-scales previously in the cerebellar cortex. PMID:26257613

  8. Caracterización espectroscópica de hielos de interés atmosférico y astrofísico

    NASA Astrophysics Data System (ADS)

    Escribano, R.

    En años recientes se ha incrementado el estudio de procesos físicos y químicos que tienen lugar en la superficie o el interior de hielos, tanto en medios astrofísicos como en la atmósfera terrestre y en otros cuerpos del sistema solar. Se ha comprobado que las partículas heladas actúan como catalizadores de reacciones químicas, que no ocurrirían en su ausencia. En la atmósfera terrestre, es bien conocida la importancia de partículas de hidratos de ácido nítrico, formando las llamadas nubes estratosféricas polares, en los procesos de destrucción de ozono estratosférico. En hielos astrofísicos, átomos como H, C, N y O pueden adherirse o introducirse en la estructura cristalina o amorfa del hielo, y dar lugar a reacciones de formación de moléculas evitando su barrera de activación. Existen partículas heladas en el medio interestelar formando parte de las llamadas nubes moleculares densas y frías, con valores del orden de 106 átomos de H por cm3 y temperaturas entre 3 y 90 K. Alrededor de protoestrellas, pueden formarse hielos de distinta composición, polares o apolares, en las zonas de alejamiento y temperatura decreciente a partir del núcleo caliente. Por su parte, los cometas están formados por un núcleo de hielo y rocas, sobre el que se encuentran adheridas moléculas gaseosas, y una cola, formada por los gases liberados por efecto del calentamiento debido a la radiación solar incidente. En nuestro sistema solar, los polos de La Tierra y de Marte están cubiertos de hielo, así como la mayoría de los cuerpos externos. Los satélites de Júpiter han sido estudiados detalladamente, y se han encontrado en ellos, y en Tritón (satélite de Neptuno), hielos de moléculas como SON2, CO2, N2, CH4 y otros. Para la caracterización espectroscópica de estos hielos se precisan medidas en el laboratorio, aún conociendo la imposibilidad intrínseca de reproducir exactamente las condiciones en que se formaron y se encuentran en los medios astrof

  9. The projection of the primary somatic sensory cortex upon area 5 in the monkey.

    PubMed

    Pearson, R C; Powell, T P

    1985-04-01

    The projection of the cortex of the primary somatic sensory area (S1) upon area 5 in the rhesus monkey has been studied with axonal degeneration methods. There is little or no overlap between the major topographic representations in area 5 but there is both convergence and divergence within a representation; the degeneration after a small lesion in a representation in SI virtually fills the representation in area 5 and there is extensive overlap of the degeneration after two lesions in widely separated parts of the representation in S1. The representation of the arm in area 5 is surprisingly large, that of the face is relatively smaller than in S1 and the trunk and leg are about the same as in S1. Lesions in the trunk and face representations result in terminal degeneration throughout the antero-posterior extent of area 5, but after damage of the limb representations the degeneration in area 5 is concentrated into 3 medio-laterally disposed bands. Of the cytoarchitectonic subdivisions of S1, area 2 projects most heavily upon area 5 and area 3b the least, and there is a reversal in the antero-posterior dimension with more posterior parts of S1 projecting to more anterior parts of area 5. The corticocortical fibres from S1 end in layers III and IV of area 5, and while the degeneration in layer IV is continuous it is in distinct 'prongs' in layer III. PMID:3995356

  10. [Arterial hypertension caused by anomaly of the renal artery or its branches in children].

    PubMed

    Broyer, M; Lenoir, G; Guesry, P; Levy-Bentolila, D; Gubler, M C

    1979-11-01

    38 cases of severe hypertension due to a vascular abnormality of the renal pedicle were studied in children under 16 years of age, 18 boys and 20 girls. The most common presentation was at routine clinical examination. The diagnosis of an abnormality of the renal artery was suggested by the appearances of intravenous urography. There were many causes; 4 aneurysms of the renal artery or its branches, 4 fibromuscular dysplasias with one case of bilateral fibromuscular dysplasia, 4 idiopathic stenoses, 2 endarteritis, and 6 thromboses revascularised to variable degrees (2 after umbilical vein catheterisation and one due to DLE). In three cases the hypertension was related to compression of the pedicle by a tumour of haematome, and 14 cases had multiple arterial lesion. In the latter group, 6 cases of neurofibromatosis, 2 cases of William and Beuren's disease, 1 case of generalised Elastorhexia, 2 cases of aortic medio stenosis, probably Takayashu's disease, and 3 unidentified conditions. Surgery was performed on 29 patients, 21 of whom had unilateral lesions and were definitively cured of hypertension. Of the 8 cases with multiple lesions, only 2 were completely corrected with cure of their hypertension. PMID:119510