1,222 research outputs found

    Stability Analysis of a Bose-Einstein Condensate Trapped in a Generic Potential

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    We investigate the dynamical behavior of the Gross-Pitaevskii equation for a Bose-Einstein condensate trapped in a spherical power law potential restricted to the repulsive case, from the dynamical system formalism point of view. A five-dimensional dynamical system is found (due the symmetry of the Gross-Pitaevskii equation interacting with a potential), where the Thomas-Fermi approximation constrains the parameter space of solutions. We show that for values of the power law exponent equal or smaller than 2 the system seems to be stable. However, when the corresponding exponent is bigger than 2, the instability of the system grows when the power law exponent grows, indicating that large values of the aforementioned parameter can be related to a loss in the number of particles from the condensed state. This fact can be used also to show that the stability conditions of the condensate are highly sensitive to the exponent associated with the external potential.Comment: 9 pages, 2 figure

    Evaluation of the Response of Posttensioned Steel Frames with Energy Dissipators Using Equivalent Single-Degree-of-Freedom Systems

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    The hysteretic energy (EH) dissipated in posttensioned steel frames (PTSF) with hysteretic dampers is calculated by using equivalent single-degree-of-freedom systems (ESDOFS), where the nonlinearity of both the steel bars (beam and columns) and the connections of the structural frame is separately considered. Five multi-degree-of-freedom (MDOFS) PTSF and their corresponding ESDOFS are studied under the action of 30 seismic motions recorded in soft ground, scaled in terms of the spectral pseudoacceleration evaluated at the fundamental period of the structures. Several simple mathematical expressions are proposed. The first expression is useful to calculate modifying factors (FMEH) to relate EH of the ESDOFS with that of the MDOFS; the second is to determine the interstory drift (γ) as a function of the seismic intensity. The third equation is to calculate the factor of the relative participation of the energy that the connections dissipate with respect to the total energy EH and the fourth equation, which is function of the γ, is to obtain the distribution factors of EH through the height of the structure. The methodology proposed can be used for the design or the structural revision of PTSF with dampers

    Fitogeografía de la Sierra Monte Grande, Charcas, San Luis Potosí, México

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    La sierra Monte Grande, con una extensión de 41.8 km, se localiza en el sur de la altiplanicie septentrional de México. Tiene un clima seco (8So) y en ella prevalecen los matorrales xerófilos, piñonares y encinares. A partir de su flora, compuesta por 397 especies, se analizó su fitogeografía histórica con base en los taxones (familias, géneros y especies) de distribución restringida. Al nivel de familia se identificaron tres patrones de distribución: 1) desde Norteamérica hasta el norte de Suramérica; 2) con mayor amplitud en el continente americano; 3) familias relacionadas con la región del Mediterráneo. Al nivel de género se encontraron cinco patrones: 1) endémicos de las zonas semisecas a muy secas de México y regiones adyacentes de Estados Unidos; 2) desde el sur de Estados Unidos hasta Centroamérica; 3) de distribución amplia pero con marcada relación antillana; 4) relacionados con la región del Mediterráneo; 5) disyuntos o vicariantes de las zonas áridas de Norte y Suramérica. Al nivel de especie se identificaron nueve patrones de distribución: 1) altiplanicie septentrional; 2) altiplanicie meridional; 3) altiplanicie y zonas adyacentes; 4) altiplanicie-Sierra Madre de Oaxaca; 5) altiplanicie-planicie costera noroccidental; 6) altiplanicie-planicies costeras noroccidental y nororiental; 7) altiplanicie-planicie costera nororiental; 8) región xerofítica mexicana; 9) altiplanicie sierras Madre. Se descarta que estos patrones sean casuales, pues concuerdan con teorías recientes sobre el proceso que culminó con la configuración actual del continente; se postula un papel destacado del Caribe en la florigénesis de linajes vegetales actuales de las zonas semisecas, secas y muy secas de México y en el mismo sentido un papel destacado del Mediterráneo Antiguo.Monte Grande is a small (41.8 km) mountain range located at the southernmost part of the northern plateau of Mexico. It has a dry climate and its vegetation is characterized by pinyon woodland, oak scrub and three kinds of xerophytic scrub. Based on its flora of 397 species, we analyzed the historie phytogeography of Monte Grande, using only the taxa (families, genera and species) that have a restricted distribution. At the family level, we identified three patterns of distribution: 1) from North America to northern South America; 2) mostly in the American continent; 3) families related to the Mediterranean region. At the genus level, five patterns were identified: 1) endemic of arid and semiarid lands of Mexico and adjacent regions of the United States; 2) from southern United States to Central America; 3) broadly distributed, but highly related to the Antillean region; 4) with Mediterranean relations; 5) disjunct or vicariant between the arid lands of North and South America. At the species level, nine patterns of distribution were identified: 1) septentrional plateau; 2) meridional plateau; 3) all plateaus and adjacent regions; 4) all plateaus-Sierra Madre de Oaxaca; 5) all plateaus-northwestern coast plain; 6) all plateaus-both coastal plains; 7) all plateaus-northeastern coastal plain; 8) Mexican xerophytic region; 9) all plateaus-both sierras Madre. These patterns are unlikely to be accidental, as they agree with recent theories about the process that led to the present landform configuration of the American Continent. On the basis of this interpretation, we postulate a major role of the Caribbean and the Former Mediterranean in the florigenesis of present linages of the arid and semiarid lands of Mexico

    Fitogeografía de la Sierra Monte Grande, Charcas, San Luis Potosí, México

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    La sierra Monte Grande, con una extensión de 41.8 km, se localiza en el sur de la altiplanicie septentrional de México. Tiene un clima seco (8So) y en ella prevalecen los matorrales xerófilos, piñonares y encinares. A partir de su flora, compuesta por 397 especies, se analizó su fitogeografía histórica con base en los taxones (familias, géneros y especies) de distribución restringida. Al nivel de familia se identificaron tres patrones de distribución: 1) desde Norteamérica hasta el norte de Suramérica; 2) con mayor amplitud en el continente americano; 3) familias relacionadas con la región del Mediterráneo. Al nivel de género se encontraron cinco patrones: 1) endémicos de las zonas semisecas a muy secas de México y regiones adyacentes de Estados Unidos; 2) desde el sur de Estados Unidos hasta Centroamérica; 3) de distribución amplia pero con marcada relación antillana; 4) relacionados con la región del Mediterráneo; 5) disyuntos o vicariantes de las zonas áridas de Norte y Suramérica. Al nivel de especie se identificaron nueve patrones de distribución: 1) altiplanicie septentrional; 2) altiplanicie meridional; 3) altiplanicie y zonas adyacentes; 4) altiplanicie-Sierra Madre de Oaxaca; 5) altiplanicie-planicie costera noroccidental; 6) altiplanicie-planicies costeras noroccidental y nororiental; 7) altiplanicie-planicie costera nororiental; 8) región xerofítica mexicana; 9) altiplanicie sierras Madre. Se descarta que estos patrones sean casuales, pues concuerdan con teorías recientes sobre el proceso que culminó con la configuración actual del continente; se postula un papel destacado del Caribe en la florigénesis de linajes vegetales actuales de las zonas semisecas, secas y muy secas de México y en el mismo sentido un papel destacado del Mediterráneo Antiguo.Monte Grande is a small (41.8 km) mountain range located at the southernmost part of the northern plateau of Mexico. It has a dry climate and its vegetation is characterized by pinyon woodland, oak scrub and three kinds of xerophytic scrub. Based on its flora of 397 species, we analyzed the historie phytogeography of Monte Grande, using only the taxa (families, genera and species) that have a restricted distribution. At the family level, we identified three patterns of distribution: 1) from North America to northern South America; 2) mostly in the American continent; 3) families related to the Mediterranean region. At the genus level, five patterns were identified: 1) endemic of arid and semiarid lands of Mexico and adjacent regions of the United States; 2) from southern United States to Central America; 3) broadly distributed, but highly related to the Antillean region; 4) with Mediterranean relations; 5) disjunct or vicariant between the arid lands of North and South America. At the species level, nine patterns of distribution were identified: 1) septentrional plateau; 2) meridional plateau; 3) all plateaus and adjacent regions; 4) all plateaus-Sierra Madre de Oaxaca; 5) all plateaus-northwestern coast plain; 6) all plateaus-both coastal plains; 7) all plateaus-northeastern coastal plain; 8) Mexican xerophytic region; 9) all plateaus-both sierras Madre. These patterns are unlikely to be accidental, as they agree with recent theories about the process that led to the present landform configuration of the American Continent. On the basis of this interpretation, we postulate a major role of the Caribbean and the Former Mediterranean in the florigenesis of present linages of the arid and semiarid lands of Mexico

    HPV-16 infection modifies overall survival of Puerto Rican HNSCC patients

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    International audienceThis paper presents a set of experimental results concerning the sliding mode control of an electro-pneumatic system. Two discrete-time control strategies are considered for the implementation of the discontinuous part of the sliding mode controller: explicit and implicit discretizations. While the explicit implementation is known to generate numerical chattering [6], [7], [12], [13], the implicit one is expected to significantly reduce chattering while keeping the accuracy. The experimental results reported in this work remarkably confirm that the implicit discrete-time sliding mode supersedes the explicit ones, with several important features: chattering in the control input is almost eliminated (while the explicit and saturated controllers behave like high-frequency bang-bang inputs), the input magnitude depends only on the perturbation size and is largely independent of the controller gain and sampling time

    Análisis Discursivo de la Motricidad Orofacial en Colombia

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      Introducción: Analizar desde el discurso de los actores sociales la historia de la Motricidad Orofacial (MO) en Colombia. Métodos: Participaron en el estudio 24 personas, con participación de 4 Expertas, 15 Profesionales y 5 estudiantes. El análisis discursivo fue realizado a partir del enfoque cartográfico apoyado en la técnica de codificación. Resultados: La cartografía da cuenta de tres momentos históricos: 1. La llegada de la MO a Colombia, centrada en las dificultades de acceso a la información. 2. El crecimiento y formación en MO, de la mano de Garliner y Segovia. 3. El cambio de Paradigma, de los trastornos oclusivos a los enfoques neuromotores. Análisis: La MO en Colombia conserva una configuación cartográfica de saber-poder centrada en las formas de control discursivo centradas en el comentario, el autor y la disciplina; de esta manera el estatuto de control se centra en un dispositivo de verdad basado en el saber histórico. La historicidad de este saber se decanta en la existencia de nociones como Terapia Miofuncional y Deglución Atípica, en oposición a la emergencia de nuevas categorias como MO, Deglución Adaptada y enfoque funcional de la atención en salud. Conclusiones: La MO en Colombia aún está construyendo su reconocimiento como parte del estatuto disciplinar de la Fonoaudiología, evento claramente visible en la asignación de dedicación académica al área dentro de los programas de formación pregradual vigentes

    Hospitalisation by tick-borne diseases in the last 10 years in two hospitals in South Spain: analysis of tick exposure data collected in the Emergency Department

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    Tick-borne diseases (TBDs) can sometimes cause severe symptoms and lead to hospitalisation, but they often go unnoticed in the Emergency Department (ED). The aim of this study was twofold: (i) to describe the profile of patients hospitalised by TBDs; and (ii) to evaluate the data collected in the medical records from the ED in order to analyse their potential clinical consequences. A total of 84 cases that included all TBD diagnoses registered in the ED records were identified and analysed. These corresponded to all the hospitalisations by TBDs in the last 10 years (2009–2019) in two tertiary hospitals in Granada, Spain. Statistical analyses were made using RStudio. Coinciding with the absence of patient’s report of exposure to ticks, 64.3% of TBDs were not suspected in the ED. Intensive care unit admission was required in 8.3% of cases, and the mortality rate was 2.4%. Non-suspected cases showed longer hospital stay (P < 0.001), treatment duration (P = 0.02) and delay in the initiation of antibiotic treatment (P < 0.001). Our findings indicate that symptoms associated with TBDs are highly non-specific. In the absence of explicit information related to potential tick exposure, TBDs are not initially suspected. As a consequence, elective treatment administration is delayed and hospitalisation time is prolonged. In conclusion, our results highlight the importance of addressing potential exposure to ticks during the ED contact with patients presenting with febrile syndrome
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