1,281 research outputs found
Effects of internal fluctuations on the spreading of Hantavirus
We study the spread of Hantavirus over a host population of deer mice using a
population dynamics model. We show that taking into account the internal
fluctuations in the mouse population due to its discrete character strongly
alters the behaviour of the system. In addition to the familiar transition
present in the deterministic model, the inclusion of internal fluctuations
leads to the emergence of an additional deterministically hidden transition. We
determine parameter values that lead to maximal propagation of the disease, and
discuss some implications for disease prevention policies
Extracellular vesicle-mediated communication in host-parasite interactions: insight from Fasciola hepatica
Seguridad del paciente en la sedación profunda para procedimientos endoscópicos digestivos
La sedación profunda con propofol se ha popularizado en los últimos años. La seguridad de esta técnica cuando se administra por no anestesiólogos, ha generado gran controversia que a veces se enmascara en un discutible debate sobre la sostenibilidad económica del sistema sanitario. En el año 2011 la Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor junto con otras 20 sociedades de países europeos, revocan las recomendaciones de la Sociedad Europea de Gastroenterólogos sobre administración de propofol por no anestesiólogos por ser “sumamente peligroso para la seguridad y calidad de los procedimientos endoscópicos”. Previamente la FDA había rechazado en el año 2005 el uso del propofol por no anestesiólogos en Estados Unidos, prohibición que fue reiterada en 2010 y que sigue en vigor, apoyándose entre otras, en las recomendaciones y estándares de la Joint Comissión y de la Declaración de Helsinki. En España, la ficha técnica del propofol establece el uso restringido del propofol a anestesiólogos y a intensivistas dentro de las unidades de Cuidados Intensivos En nuestra opinión los elementos clave a discutir (que son los que desarrollamos en nuestro artículo) serían los relacionados con: a) la morbimortalidad de la sedación (que es lo mismo que hablar de los factores que influyen en su seguridad), b) el profesional adecuado para emplear esa técnica y c) los aspectos económicos vinculados al uso de la misma. Concluimos que no se puede afirmar que una técnica es segura cuando un alto porcentaje de pacientes presentan depresión respiratoria variable (y por tanto hipoxemia) e hipotensión. Estamos seguros que la Colaboración de la Sociedad Española de Patología Digestiva (SEPD) y de Sociedad Española de Endoscopia Digestiva (SEED), con la Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor (SEDAR), es el primer paso para buscar una solución satisfactoria para todos y especialmente para nuestros pacientes.Deep sedation with Propofol has become popular in recent years. The safety of this technique when administered by non-anaesthesiologists has created much controversy which at times is masked in a contentious debate on the economic sustainability of the health system. In 2011, the Spanish Society of Anaesthesiology, Resuscitation and Pain Therapy, along with 20 other organisations from European countries, revoked the recommendations of the European Society of Gastrointestinal Endoscopy on the administration of Propofol by non-anaesthesiologists, citing that it is "extremely dangerous for the safety and quality of endoscopic procedures". The FDA in 2005 had already rejected the use of Propofol by non-anaesthesiologists in the United States, a prohibition which was reiterated in 2010 and is still in force, basing its evidence, among others, on the recommendations and guidelines of the Joint Commission and the Declaration of Helsinki. In Spain, the data sheet of Propofol restricts the use of the drug to anaesthesiologists and intensivists in intensive care units. In our opinion, the key elements to discuss (which we develop in our paper) are those related to: a) the morbidity and mortality of sedation (which is the same as speaking about the factors that influence its safety); b) the appropriate professionals to use this technique; and c) economic aspects related to the use of said technique. Our conclusion is that a technique cannot be declared safe when a high percentage of patients present with varying respiratory depression (and therefore hypoxaemia) and hypotension. We are confident that the collaboration of the Spanish Society of Digestive Pathology and the Spanish Society of Digestive Endoscopy with the Spanish Society of Anaesthesiology, Resuscitation and Pain Therapy is the first step towards finding a satisfactory solution for everyone, and especially for our patients.S
Monitoring Tools in Robust CWM for the Analysis of Crime Data
Robust inference for the Cluster Weighted Model requires the specification of a few hyper-parameters. Their role is crucial for increasing the quality of the estimators, while arbitrary decisions about their value could severely hamper inferential results. To guide the user in the delicate choice of such parameters, a monitoring approach has been introduced in the recent literature, yielding an adaptive method. The approach is here exemplified, via the analysis of a dataset on the effect of punishment regimes on crime rates
Robust Fuzzy Clustering via Trimming and Constraints
Producción CientíficaA methodology for robust fuzzy clustering is proposed. This
methodology can be widely applied in very different statistical problems given
that it is based on probability likelihoods. Robustness is achieved by trimming
a fixed proportion of “most outlying” observations which are indeed
self-determined by the data set at hand. Constraints on the clusters’ scatters
are also needed to get mathematically well-defined problems and to avoid the
detection of non-interesting spurious clusters. The main lines for computationally
feasible algorithms are provided and some simple guidelines about
how to choose tuning parameters are briefly outlined. The proposed methodology
is illustrated through two applications. The first one is aimed at heterogeneously
clustering under multivariate normal assumptions and the second
one migh be useful in fuzzy clusterwise linear regression problems.Ministerio de Economía, Industria y Competitividad (MTM2014-56235-C2-1-P)Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA212U13
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