Amplificación sísmica: Una aproximación por Elementos Finitos

En las páginas que siguen se presenta el estudio de uno de los más típicos problemas de dinámica estructural, cual es la obtención de la respuesta de una estructura excitada por un movimiento de la base. Este es un caso muy frecuente en ingeniería sísmica, donde el objeto del estudio puede ser el edificio (sometido a un movimiento en la cimentación) o un estrato de terreno sobre fondo rígido. Al objeto de facilitar un soporte intuitivo a la exposicióri, ésta se organiza en base al segundo de los casos citados (estrate en base rígida). La aproximación escogida, elementos finitos, pone de relieve una vez más la potencia y generalidad del método en lo que respecta a la formulación del sistema de equilibrio. La discusión se centra en un aspecto concreto del método: la elección de funciones de forma.The goal of this paper is to present the analysis of one of the most typical problems in dynamics: the response of a structure excited by a rigid-base motion. This is an usual case in seismic engineering, where the structure can be a building or a soil stratum lying on a rigid bed. In both cases the model will be the same but, in order to give a physical support to exposure, the later will be treated. The choosed approach, by finite elements, points up the power and the generality of that method with respect to equilibrium formulation. Emphasis is done over the choosing of shape functions.Peer Reviewe

Preterición de descendiente sobrevenido al testamento: Calificación y acciones sucesorias tardías

La preterición de descendiente sobrevenido al testamento supone la ausencia de relación jurídica entre causante y preterido al tiempo de su otorgamiento, lo que explica que se califique como no intencional y que en consecuencia proceda la apertura de la sucesion intestada. Recientes resoluciones judiciales evidencian que cuando la superveniencia del legitimario obedece a una sentencia de filiación se generan conflictos frecuentes, carentes de respuesta segura, que conviene analizar. Los problemas se centran principalmente en la calificación y determinación de los consiguientes efectos de la preterición, así como en el ejericio entremezclado, y muchas veces tardío, de distintas acciones sucesorias. The preterition of descendants arising after testament implies the absence of legal relation, at the moment it is made, between the testator and the forced heirs, so it is unintentional and intestate succession shall occur. Recent case law reveals that in case of child determining his filiation by final judgement there are frequent conflicts and important concerns without legal solutions that must be taken into consideration. Problems are focused on both the characterization and consequences of the figure and the appropriate legal actions in this matter, mainly in relation with late exercise of legal proceedings by the omitted descendant

A Bayesian approach to RFI mitigation

Interfering signals such as Radio Frequency Interference from ubiquitous satellite constellations are becoming an endemic problem in fields involving physical observations of the electromagnetic spectrum. To address this we propose a novel data cleaning methodology. Contamination is simultaneously flagged and managed at the likelihood level. It is modeled in a Bayesian fashion through a piecewise likelihood that is constrained by a Bernoulli prior distribution. The techniques described in this paper can be implemented with just a few lines of code.Comment: 6 pages, 4 figures, accepted by Physical Review D (APS

Treatment outcome of children with severe acute malnutrition admitted to therapeutic feeding centers in Southern Region of Ethiopia

Background: Inadequate intake of carbohydrates, proteins, vitamins and minerals is one of the causes for malnutrition. It often affects young children and contributes to more than 60% of deaths in children in developing countries. One in four of malnourished children receiving traditional treatment die during or soon after treatment. The study aimed to assess the treatment outcome of children treated in therapeutic feeding centers (TFC) in southern Ethiopia.Methods: A retrospective review of reports submitted by the TFCs was done during 2003-2004. Data was collected from the monthly reports using standardized formats. The variables included age, treatment centers, type of malnutrition and treatment outcome which were analyzed using descriptive statistics.Results: Of 11,335 cases of malnutrition, 47% (5447) had severe wasting and 53% (6103) had edematous malnutrition. Of the total, 87% (11,191) were cured while 3.6% (468) had died. The average length of stay was 25 and 21 days with an average weight gain of 14 and 13.4 g/kg/d for children with severe wasting and edematous malnutrition, respectively. With increasing age, the death rate decrease  and cure rate increased (p < 0.05 for both).Discussion: Our results show that the new management approach  implemented in the TFC improved the treatment outcome of malnourished children compared to the minimum international standard set for  management of severe acute malnutrition which is cure rate of at least 75% and death rate less than 10%, average length of stay of less than30 days and average weight gain of 8g/kg/day

Regulation of Hoxb4 induction after neurulation by somite signal and neural competence

<p>Abstract</p> <p>Background</p> <p>While the body axis is largely patterned along the anterior-posterior (A-P) axis during gastrulation, the central nervous system (CNS) shows dynamic changes in the expression pattern of <it>Hox </it>genes during neurulation, suggesting that the CNS refines the A-P pattern continuously after neural tube formation. This study aims at clarifying the role of somites in up-regulating <it>Hoxb4 </it>expression to eventually establish its final pattern and how the neural tube develops a competence to respond to extrinsic signals.</p> <p>Results</p> <p>We show that somites are required for the up-regulation of <it>Hoxb4 </it>in the neural tube at the level of somites 1 to 5, the anterior-most domain of expression. However, each somite immediately adjacent to the neural tube is not sufficient at each level; planar signaling is additionally required particularly at the anterior-most segments of the expression domain. We also show that the dorsal side of the neural tube has a greater susceptibility to expressing <it>Hoxb4 </it>than the ventral region, a feature associated with dorsalization of the neural tube by BMP signals. BMP4 is additionally able to up-regulate <it>Hoxb4 </it>ventrally, but the effect is restricted to the axial levels at which <it>Hoxb4 </it>is normally expressed, and only in the presence of retinoic acid (RA) or somites, suggesting a role for BMP in rendering the neural tube competent to express <it>Hoxb4 </it>in response to RA or somite signals.</p> <p>Conclusion</p> <p>In identifying the collaboration between somites and neural tube competence in the induction of <it>Hoxb4</it>, this study demonstrates interplay between A-P and dorsal-ventral (D-V) patterning systems, whereby a specific feature of D-V polarity may be a prerequisite for proper A-P patterning by <it>Hox </it>genes.</p

Verbal Memory and IQ Predict Adaptive Behavior in Children and Adolescents with High-Functioning Autism Spectrum Disorders

Adaptive deficits are commonly found in high functioning autism spectrum disorders (HF-ASD) despite of cognitive potential. Most studies have focused on the relationships between adaptive behavior and intellectual quotient (IQ) and have used correlations to study relationships between them. Few studies have analyzed cognitive variables other than IQ as potential predictors of adaptive behavior in HF-ASD using regression methods. This study aimed to analyze the impact of several cognitive variables on adaptive behavior in a sample of children and adolescents with HF-ASD. METHODS: Sample included 16 child and adolescent boys with HF-ASD (age between 7-17 years). Cognitive assessment included measures of general intelligence, visual memory, verbal memory, working memory and problem solving/flexibility tests. Vineland Adaptive Behavior Scales (VABS) was used to evaluate adaptive behavior. To establish the predictive capacity of the cognitive variables for adaptive functioning, linear regression models were fitted for each adaptive domain using a stepwise method. RESULTS: Verbal memory and IQ emerged as the main independent predictors for VABS adaptive scores. The 41% of the variance in Communication was predicted by IQ. The 35% of the variance in Daily Living Skills was predicted by verbal memory. Almost half of the variance in Socialization was predicted by both, verbal memory and IQ (49%). No other cognitive functions were associated with adaptive scores. CONCLUSIONS: The results highlight the strong impact of IQ and verbal memory on adaptive behavior in HF-ASD patients. These findings could contribute to identify potential targets of intervention