905 resultados para need is great
Climate refugia: joint inference from fossil records, species distribution models and phylogeography
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Climate refugia, locations where taxa survive periods of regionally adverse climate, are thought to be critical for maintaining biodiversity through the glacial–interglacial climate changes of the Quaternary. A critical research need is to better integrate and reconcile the three major lines of evidence used to infer the existence of past refugia – fossil records, species distribution models and phylogeographic surveys – in order to characterize the complex spatiotemporal trajectories of species and populations in and out of refugia. Here we review the complementary strengths, limitations and new advances for these three approaches. We provide case studies to illustrate their combined application, and point the way towards new opportunities for synthesizing these disparate lines of evidence. Case studies with European beech, Qinghai spruce and Douglas-fir illustrate how the combination of these three approaches successfully resolves complex species histories not attainable from any one approach. Promising new statistical techniques can capitalize on the strengths of each method and provide a robust quantitative reconstruction of species history. Studying past refugia can help identify contemporary refugia and clarify their conservation significance, in particular by elucidating the fine-scale processes and the particular geographic locations that buffer species against rapidly changing climate.
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BACKGROUND There is great variability for the type of anaesthesia used during TAVI, with no clear consensus coming from comparative studies or guidelines. We sought to detect regional differences in the anaesthetic management of patients undergoing transcatheter aortic valve implantation (TAVI) in Europe and to evaluate the relationship between type of anaesthesia and in-hospital and 1year outcome. METHODS Between January 2011 and May 2012 the Sentinel European TAVI Pilot Registry enrolled 2807 patients treated via a transfemoral approach using either local (LA-group, 1095 patients, 39%) or general anaesthesia (GA-group, 1712 patients, 61%). RESULTS A wide variation in LA use was evident amongst the 10 participating countries. The use of LA has increased over time (from a mean of 37.5% of procedures in the first year, to 57% in last 6months, p<0.01). MI, major stroke as well as in-hospital death rate (7.0% LA vs 5.3% GA, p=0.053) had a similar incidence between groups, confirmed in multivariate regression analysis after adjusting for confounders. Dividing our population in tertiles according to the Log-EuroSCORE we found similar mortality under LA, whilst mortality was higher in the highest risk tertile under GA. Survival at 1year, compared by Kaplan-Meier analysis, was similar between groups (log-rank: p=0.1505). CONCLUSIONS Selection of anaesthesia appears to be more influenced by national practice and operator preference than patient characteristics. In the absence of an observed difference in outcomes for either approach, there is no compelling argument to suggest that operators and centres should change their anaesthetic practice.
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The global social and economic burden of HIV/AIDS is great, with over forty million people reported to be living with HIV/AIDS at the end of 2005; two million of these are children from birth to 15 years of age. Antiretroviral therapy has been shown to improve growth and survival of HIV-infected individuals. The purpose of this study is to describe a cohort of HIV-infected pediatric patients and assess the association between clinical factors, with growth and mortality outcomes. ^ This was a historical cohort study. Medical records of infants and children receiving HIV care at Mulago Pediatric Infectious Disease Clinic (PIDC) in Uganda between July 2003 and March 2006 were analyzed. Height and weight measurements were age and sex standardized to Centers for Disease Control and prevention (CDC) 2000 reference. Descriptive and logistic regression analyses were performed to identify covariates associated with risk of stunting or being underweight, and mortality. Longitudinal regression analysis with a mixed model using autoregressive covariance structure was used to compare change in height and weight before and after initiation of highly active antiretroviral therapy (HAART). ^ The study population was comprised of 1059 patients 0-20 years of age, the majority of whom were aged thirteen years and below (74.6%). Mean height-for-age before initiation of HAART was in the 10th percentile, mean weight-for-age was in the 8th percentile, and the mean weight-for-height was in the 23rd percentile. Initiation of HAART resulted in improvement in both the mean standardized weight-for-age Z score and weight-for-age percentiles (p <0.001). Baseline age, and weight-for-age Z score were associated with stunting (p <0.001). A negative weight-for-age Z score was associated with stunting (OR 4.60, CI 3.04-5.49). Risk of death decreased from 84% in the >2-8 years age category to 21% in the >13 years age category respectively, compared to the 0-2 years of age (p <0.05). ^ This pediatric population gained weight significantly more rapidly than height after starting HAART. A low weight-for-age Z score was associated with poor survival in children. These findings suggest that age, weight, and height measurements be monitored closely at Mulago PIDC. ^
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Streptococcus mutans has been identified as the primary etiological agent of human dental caries. Since its identification, there has been research focused on the development of a vaccine to prevent this disease. Preliminary research has been conducted to test both active and passive vaccines for Streptococcus mutans in animals and humans. Although a vaccine for dental caries caused by Streptococcus mutans would most likely be administered to children, no testing of any type of dental caries vaccines has been conducted on children as of yet. The public health imperative for the development of a vaccine is great. Not only will a vaccine reduce the various consequences, but it would also improve quality of life for many individuals. Among the many possible vaccine antigen candidates, researchers have also been focusing on protein antigens, GTFs, and Gbps as possible candidates for a vaccine. There are also many routes of administration under research, with topical, oral, and intranasal showing a lot of promise. This review will provide an overview on the current state of research, present key factors influencing prevalence of caries, and summarize and discuss the results of animal and human studies on caries vaccines against Streptococcus mutans. The progress and obstacles facing the development of a vaccine to fight dental caries will also be discussed. ^
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El resveratrol es considerado una fitoalexina pues es sintetizado como respuesta a patógenos (factores bióticos) y en condiciones climáticas adversas (factores abióticos). Actualmente existe mucho interés en él por su potencial uso en farmacología como antioxidante. Mediante cromatografía de líquidos de alta resolución (HPLC) se determinó el contenido de resveratrol en hojas de 18 accesiones de vides nativas de Puebla, México, cuatro de ellas creciendo en cuatro condiciones ambientales diferentes. Las concentraciones fueron muy variables, estimándose 39,5 μg g−1 peso fresco como valor máximo, mientras que en algunas accesiones no fue posible detectar resveratrol. Se observaron diferencias en el contenido de resveratrol para accesiones creciendo en localidades diferentes, lo que sugiere alta influencia de los factores ambientales sobre la expresión del genotipo en la inducción o inhibición de la biosíntesis de dicho metabolito secundario.
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Con esta presentación he buscado sustentar la función significativa que cumplen las Expresiones Motrices en la configuración de derechos ciudadanos que se manifiestan en identidad,interacción, inclusión, interculturalidad, visibilización, vinculación, democracia, respeto, resistencia, arraigo, diferencia, autonomía, transformación. Para ello he abordado la ciudadanía como ese rasgo sustantivo de la estructura social y cultural que permite el reconocimiento de los derechos diferenciados en función de la pertenencia al grupo, en la tensión autonomía-democracia. Una suerte de insistencia en la búsqueda del bien común, en el sentido de lo público y en la protección del sentido propio. A partir de la evidencia recabada a lo largo de mi historia profesional, denominada aquí "experiencia significativa", intento dar cuenta de los derechos ciudadanos que se promueven en las Expresiones Motrices, de ahí la referencia permanente a prácticas y producciones personales
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Con esta presentación he buscado sustentar la función significativa que cumplen las Expresiones Motrices en la configuración de derechos ciudadanos que se manifiestan en identidad,interacción, inclusión, interculturalidad, visibilización, vinculación, democracia, respeto, resistencia, arraigo, diferencia, autonomía, transformación. Para ello he abordado la ciudadanía como ese rasgo sustantivo de la estructura social y cultural que permite el reconocimiento de los derechos diferenciados en función de la pertenencia al grupo, en la tensión autonomía-democracia. Una suerte de insistencia en la búsqueda del bien común, en el sentido de lo público y en la protección del sentido propio. A partir de la evidencia recabada a lo largo de mi historia profesional, denominada aquí "experiencia significativa", intento dar cuenta de los derechos ciudadanos que se promueven en las Expresiones Motrices, de ahí la referencia permanente a prácticas y producciones personales
Resumo:
Con esta presentación he buscado sustentar la función significativa que cumplen las Expresiones Motrices en la configuración de derechos ciudadanos que se manifiestan en identidad,interacción, inclusión, interculturalidad, visibilización, vinculación, democracia, respeto, resistencia, arraigo, diferencia, autonomía, transformación. Para ello he abordado la ciudadanía como ese rasgo sustantivo de la estructura social y cultural que permite el reconocimiento de los derechos diferenciados en función de la pertenencia al grupo, en la tensión autonomía-democracia. Una suerte de insistencia en la búsqueda del bien común, en el sentido de lo público y en la protección del sentido propio. A partir de la evidencia recabada a lo largo de mi historia profesional, denominada aquí "experiencia significativa", intento dar cuenta de los derechos ciudadanos que se promueven en las Expresiones Motrices, de ahí la referencia permanente a prácticas y producciones personales
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Port services, and in particular the cargo handling service, are responsible for the greatest share of costs incurred during the passage of cargo through a port. The provision of these services reliably and efficiently is crucial in a sector in which there is great opacity. This study has provided the responsible administration ? the Port Authority ? with a tool enabling objective decision making both when it comes to issuing the corresponding licenses and during the period of service provision. Furthermore, we have proposed a series of measures whose application would improve the conditions of service provision and reduce the costs incurred by the passage of cargo through the port.
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Project planning and architectural management of a port area should include many variables, it must be in harmony with its environment and its historical development as the key to successful integration. This article explains the elements which should be taken into account when doing such planning by describing the proposal presented on the ?Concurso public internacional de ideas para proyectar la ordenación urbanística y arquitectónica del área central del puerto de Vigo?, with the aim of sharing comprehensive applied design philosofy, it will inspire and help future designers. Creative imagination is great added value to engineering creations, but should not overwhelm functionality and sustainability, but to be in harmony with them. The maximum aesthetic expression in engineering is achieved as the product of the conceptual elegance of the functionality of the structures.
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La computación ubicua está extendiendo su aplicación desde entornos específicos hacia el uso cotidiano; el Internet de las cosas (IoT, en inglés) es el ejemplo más brillante de su aplicación y de la complejidad intrínseca que tiene, en comparación con el clásico desarrollo de aplicaciones. La principal característica que diferencia la computación ubicua de los otros tipos está en como se emplea la información de contexto. Las aplicaciones clásicas no usan en absoluto la información de contexto o usan sólo una pequeña parte de ella, integrándola de una forma ad hoc con una implementación específica para la aplicación. La motivación de este tratamiento particular se tiene que buscar en la dificultad de compartir el contexto con otras aplicaciones. En realidad lo que es información de contexto depende del tipo de aplicación: por poner un ejemplo, para un editor de imágenes, la imagen es la información y sus metadatos, tales como la hora de grabación o los ajustes de la cámara, son el contexto, mientras que para el sistema de ficheros la imagen junto con los ajustes de cámara son la información, y el contexto es representado por los metadatos externos al fichero como la fecha de modificación o la de último acceso. Esto significa que es difícil compartir la información de contexto, y la presencia de un middleware de comunicación que soporte el contexto de forma explícita simplifica el desarrollo de aplicaciones para computación ubicua. Al mismo tiempo el uso del contexto no tiene que ser obligatorio, porque si no se perdería la compatibilidad con las aplicaciones que no lo usan, convirtiendo así dicho middleware en un middleware de contexto. SilboPS, que es nuestra implementación de un sistema publicador/subscriptor basado en contenido e inspirado en SIENA [11, 9], resuelve dicho problema extendiendo el paradigma con dos elementos: el Contexto y la Función de Contexto. El contexto representa la información contextual propiamente dicha del mensaje por enviar o aquella requerida por el subscriptor para recibir notificaciones, mientras la función de contexto se evalúa usando el contexto del publicador y del subscriptor. Esto permite desacoplar la lógica de gestión del contexto de aquella de la función de contexto, incrementando de esta forma la flexibilidad de la comunicación entre varias aplicaciones. De hecho, al utilizar por defecto un contexto vacío, las aplicaciones clásicas y las que manejan el contexto pueden usar el mismo SilboPS, resolviendo de esta forma la incompatibilidad entre las dos categorías. En cualquier caso la posible incompatibilidad semántica sigue existiendo ya que depende de la interpretación que cada aplicación hace de los datos y no puede ser solucionada por una tercera parte agnóstica. El entorno IoT conlleva retos no sólo de contexto, sino también de escalabilidad. La cantidad de sensores, el volumen de datos que producen y la cantidad de aplicaciones que podrían estar interesadas en manipular esos datos está en continuo aumento. Hoy en día la respuesta a esa necesidad es la computación en la nube, pero requiere que las aplicaciones sean no sólo capaces de escalar, sino de hacerlo de forma elástica [22]. Desgraciadamente no hay ninguna primitiva de sistema distribuido de slicing que soporte un particionamiento del estado interno [33] junto con un cambio en caliente, además de que los sistemas cloud actuales como OpenStack u OpenNebula no ofrecen directamente una monitorización elástica. Esto implica que hay un problema bilateral: cómo puede una aplicación escalar de forma elástica y cómo monitorizar esa aplicación para saber cuándo escalarla horizontalmente. E-SilboPS es la versión elástica de SilboPS y se adapta perfectamente como solución para el problema de monitorización, gracias al paradigma publicador/subscriptor basado en contenido y, a diferencia de otras soluciones [5], permite escalar eficientemente, para cumplir con la carga de trabajo sin sobre-provisionar o sub-provisionar recursos. Además está basado en un algoritmo recientemente diseñado que muestra como añadir elasticidad a una aplicación con distintas restricciones sobre el estado: sin estado, estado aislado con coordinación externa y estado compartido con coordinación general. Su evaluación enseña como se pueden conseguir notables speedups, siendo el nivel de red el principal factor limitante: de hecho la eficiencia calculada (ver Figura 5.8) demuestra cómo se comporta cada configuración en comparación con las adyacentes. Esto permite conocer la tendencia actual de todo el sistema, para saber si la siguiente configuración compensará el coste que tiene con la ganancia que lleva en el throughput de notificaciones. Se tiene que prestar especial atención en la evaluación de los despliegues con igual coste, para ver cuál es la mejor solución en relación a una carga de trabajo dada. Como último análisis se ha estimado el overhead introducido por las distintas configuraciones a fin de identificar el principal factor limitante del throughput. Esto ayuda a determinar la parte secuencial y el overhead de base [26] en un despliegue óptimo en comparación con uno subóptimo. Efectivamente, según el tipo de carga de trabajo, la estimación puede ser tan baja como el 10 % para un óptimo local o tan alta como el 60 %: esto ocurre cuando se despliega una configuración sobredimensionada para la carga de trabajo. Esta estimación de la métrica de Karp-Flatt es importante para el sistema de gestión porque le permite conocer en que dirección (ampliar o reducir) es necesario cambiar el despliegue para mejorar sus prestaciones, en lugar que usar simplemente una política de ampliación. ABSTRACT The application of pervasive computing is extending from field-specific to everyday use. The Internet of Things (IoT) is the shiniest example of its application and of its intrinsic complexity compared with classical application development. The main characteristic that differentiates pervasive from other forms of computing lies in the use of contextual information. Some classical applications do not use any contextual information whatsoever. Others, on the other hand, use only part of the contextual information, which is integrated in an ad hoc fashion using an application-specific implementation. This information is handled in a one-off manner because of the difficulty of sharing context across applications. As a matter of fact, the application type determines what the contextual information is. For instance, for an imaging editor, the image is the information and its meta-data, like the time of the shot or camera settings, are the context, whereas, for a file-system application, the image, including its camera settings, is the information and the meta-data external to the file, like the modification date or the last accessed timestamps, constitute the context. This means that contextual information is hard to share. A communication middleware that supports context decidedly eases application development in pervasive computing. However, the use of context should not be mandatory; otherwise, the communication middleware would be reduced to a context middleware and no longer be compatible with non-context-aware applications. SilboPS, our implementation of content-based publish/subscribe inspired by SIENA [11, 9], solves this problem by adding two new elements to the paradigm: the context and the context function. Context represents the actual contextual information specific to the message to be sent or that needs to be notified to the subscriber, whereas the context function is evaluated using the publisher’s context and the subscriber’s context to decide whether the current message and context are useful for the subscriber. In this manner, context logic management is decoupled from context management, increasing the flexibility of communication and usage across different applications. Since the default context is empty, context-aware and classical applications can use the same SilboPS, resolving the syntactic mismatch that there is between the two categories. In any case, the possible semantic mismatch is still present because it depends on how each application interprets the data, and it cannot be resolved by an agnostic third party. The IoT environment introduces not only context but scaling challenges too. The number of sensors, the volume of the data that they produce and the number of applications that could be interested in harvesting such data are growing all the time. Today’s response to the above need is cloud computing. However, cloud computing applications need to be able to scale elastically [22]. Unfortunately there is no slicing, as distributed system primitives that support internal state partitioning [33] and hot swapping and current cloud systems like OpenStack or OpenNebula do not provide elastic monitoring out of the box. This means there is a two-sided problem: 1) how to scale an application elastically and 2) how to monitor the application and know when it should scale in or out. E-SilboPS is the elastic version of SilboPS. I t is the solution for the monitoring problem thanks to its content-based publish/subscribe nature and, unlike other solutions [5], it scales efficiently so as to meet workload demand without overprovisioning or underprovisioning. Additionally, it is based on a newly designed algorithm that shows how to add elasticity in an application with different state constraints: stateless, isolated stateful with external coordination and shared stateful with general coordination. Its evaluation shows that it is able to achieve remarkable speedups where the network layer is the main limiting factor: the calculated efficiency (see Figure 5.8) shows how each configuration performs with respect to adjacent configurations. This provides insight into the actual trending of the whole system in order to predict if the next configuration would offset its cost against the resulting gain in notification throughput. Particular attention has been paid to the evaluation of same-cost deployments in order to find out which one is the best for the given workload demand. Finally, the overhead introduced by the different configurations has been estimated to identify the primary limiting factor for throughput. This helps to determine the intrinsic sequential part and base overhead [26] of an optimal versus a suboptimal deployment. Depending on the type of workload, this can be as low as 10% in a local optimum or as high as 60% when an overprovisioned configuration is deployed for a given workload demand. This Karp-Flatt metric estimation is important for system management because it indicates the direction (scale in or out) in which the deployment has to be changed in order to improve its performance instead of simply using a scale-out policy.
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No mundo contemporâneo as formas de atingir desempenho máximo são cruciais, resulta em altos investimentos em tecnologia com o intuito de melhorar, entre outros, o desempenho dos trabalhadores, por serem esses os responsáveis pela produção eficiente ou não de bens e serviços. A tecnologia tem sido essencial neste processo, tais recursos estão à disposição de toda e qualquer empresa. Resta então, otimizar o desempenho dos trabalhadores frente a tal cenário. Neste, a liderança que sempre foi marcante nos processos administrativos, precisa ser reavaliada com o objetivo de conhecer como ela se dá nas equipes virtuais. O trabalho em equipe num mesmo local ganhou força desde a última década e continua sendo propulsora de desempenho na década atual. Contudo, tais equipes ganharam novo papel: o de compartilhar o desenvolvimento de um bem ou serviço em locais distintos. Nasceram, então, as equipes virtuais. Este trabalho objetiva compreender como a liderança estimula a motivação dos integrantes de equipes virtuais. Com intuito de responder ao objetivo do trabalho foi realizado um estudo de caso exploratório em uma empresa multinacional francesa instalada na região metropolitana de São Paulo. O caso é composto por 10 sujeitos que cobrem todo território nacional, para a qual foi realizada entrevista pelos mesmos meios de comunicação utilizado pelos sujeitos. Como resultado obteve-se a idéia de que a liderança é de alta relevância para o caso estudado. Identificou-se que nas equipes virtuais há elementos facilitadores e dificultadores, de ordem pessoal, organizacional e de infra-estrutura.(AU)
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No mundo contemporâneo as formas de atingir desempenho máximo são cruciais, resulta em altos investimentos em tecnologia com o intuito de melhorar, entre outros, o desempenho dos trabalhadores, por serem esses os responsáveis pela produção eficiente ou não de bens e serviços. A tecnologia tem sido essencial neste processo, tais recursos estão à disposição de toda e qualquer empresa. Resta então, otimizar o desempenho dos trabalhadores frente a tal cenário. Neste, a liderança que sempre foi marcante nos processos administrativos, precisa ser reavaliada com o objetivo de conhecer como ela se dá nas equipes virtuais. O trabalho em equipe num mesmo local ganhou força desde a última década e continua sendo propulsora de desempenho na década atual. Contudo, tais equipes ganharam novo papel: o de compartilhar o desenvolvimento de um bem ou serviço em locais distintos. Nasceram, então, as equipes virtuais. Este trabalho objetiva compreender como a liderança estimula a motivação dos integrantes de equipes virtuais. Com intuito de responder ao objetivo do trabalho foi realizado um estudo de caso exploratório em uma empresa multinacional francesa instalada na região metropolitana de São Paulo. O caso é composto por 10 sujeitos que cobrem todo território nacional, para a qual foi realizada entrevista pelos mesmos meios de comunicação utilizado pelos sujeitos. Como resultado obteve-se a idéia de que a liderança é de alta relevância para o caso estudado. Identificou-se que nas equipes virtuais há elementos facilitadores e dificultadores, de ordem pessoal, organizacional e de infra-estrutura.(AU)
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Recent signaling resolution models of parent–offspring conflict have provided an important framework for theoretical and empirical studies of communication and parental care. According to these models, signaling of need is stabilized by its cost. However, our computer simulations of the evolutionary dynamics of chick begging and parental investment show that in Godfray’s model the signaling equilibrium is evolutionarily unstable: populations that start at the signaling equilibrium quickly depart from it. Furthermore, the signaling and nonsignaling equilibria are linked by a continuum of equilibria where chicks above a certain condition do not signal and we show that, contrary to intuition, fitness increases monotonically as the proportion of young that signal decreases. This result forces us to reconsider much of the current literature on signaling of need and highlights the need to investigate the evolutionary stability of signaling equilibria based on the handicap principle.
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Tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1) by the insulin receptor permits this docking protein to interact with signaling proteins that promote insulin action. Serine phosphorylation uncouples IRS-1 from the insulin receptor, thereby inhibiting its tyrosine phosphorylation and insulin signaling. For this reason, there is great interest in identifying serine/threonine kinases for which IRS-1 is a substrate. Tumor necrosis factor (TNF) inhibited insulin-promoted tyrosine phosphorylation of IRS-1 and activated the Akt/protein kinase B serine-threonine kinase, a downstream target for phosphatidylinositol 3-kinase (PI 3-kinase). The effect of TNF on insulin-promoted tyrosine phosphorylation of IRS-1 was blocked by inhibition of PI 3-kinase and the PTEN tumor suppessor, which dephosphorylates the lipids that mediate PI 3-kinase functions, whereas constitutively active Akt impaired insulin-promoted IRS-1 tyrosine phosphorylation. Conversely, TNF inhibition of IRS-1 tyrosine phosphorylation was blocked by kinase dead Akt. Inhibition of IRS-1 tyrosine phosphorylation by TNF was blocked by rapamycin, an inhibitor of the mammalian target of rapamycin (mTOR), a downstream target of Akt. mTOR induced the serine phosphorylation of IRS-1 (Ser-636/639), and such phosphorylation was inhibited by rapamycin. These results suggest that TNF impairs insulin signaling through IRS-1 by activation of a PI 3-kinase/Akt/mTOR pathway, which is antagonized by PTEN.