Dengue una enfermedad emergente y re-emergente en América

El Dengue es una enfermedad infecciosa, producida por un arbovirus cuyo único reservorio es el hombre. El virusutiliza como vector biológico al mosquito Aedes aegypti o al mosquito Aedes albopictus. La sintomatología se presentahabitualmente como un cuadro febril denominado dengue clásico, que se caracteriza por fiebre alta de presentaciónaguda, de duración limitada (2 a 7 días), con intenso malestar general, acompañado de erupción cutánea. Puedepresentar síntomas hemorrágicos de escasa intensidad, como petequias y sangramiento gingival. El tratamiento essintomático y el paciente mejora completamente en aproximadamente 7 días. Esta forma de dengue no producemortalidad. Sin embargo, existen otras presentaciones de la enfermedad que pueden llegar a manifestaciones graves deltipo hemorrágicas con muerte, lo que se presenta en el 5% de los enfermos. El dengue es un problema creciente desalud pública, que afecta a más de 100 países en el mundo, con más de 50 millones de casos informados cada año. Loscuatro tipos de dengue, están circulando en América, donde los casos aumentaron en los últimos años en formaexplosiva. Si bien, en Chile continental no se ha documentado la existencia del mosquito vector del dengue de formaendémica, si se ha hecho en Chile Insular, más específicamente en Isla de Pascua, donde desde el año 1999, seincorporó a la lista de enfermedades de declaración obligatoria (D.S. Nº 158) estableciendo su vigilancia. Los factoresque han llevado a la emergencia de esta enfermedad son principalmente el cambio climático, que ha modificado elnicho ecológico de los mosquitos de la familia Aedes. También la urbanización, la falta de control del vector, las fallasen infraestructura básica y el pobre saneamiento ambiental. La intervención primaria de salud pública ha ido por la líneadel uso de insecticidas para el control del vector y la detección temprana de casos. No existe aún una vacuna efectiva,sin embargo, actualmente se están realizando esfuerzos en esta materia

Using Both Sides of Your Brain: The Case for Rapid Interhemispheric Switching

Individual brain hemispheres are often specialized for specific aspects of a behavior. How both sides of the brain coordinate their output to produce a perfectly seamless behavior is not known. Songbirds appear to achieve this by rapidly switching back and forth between hemispheres

Reassessment of the Lineage Fusion Hypothesis for the Origin of Double Membrane Bacteria

In 2009, James Lake introduced a new hypothesis in which reticulate phylogeny reconstruction is used to elucidate the origin of Gram-negative bacteria (Nature 460: 967–971). The presented data supported the Gram-negative bacteria originating from an ancient endosymbiosis between the Actinobacteria and Clostridia. His conclusion was based on a presence-absence analysis of protein families that divided all prokaryotes into five groups: Actinobacteria, Double Membrane bacteria (DM), Clostridia, Archaea and Bacilli. Of these five groups, the DM are by far the largest and most diverse group compared to the other groupings. While the fusion hypothesis for the origin of double membrane bacteria is enticing, we show that the signal supporting an ancient symbiosis is lost when the DM group is broken down into smaller subgroups. We conclude that the signal detected in James Lake's analysis in part results from a systematic artifact due to group size and diversity combined with low levels of horizontal gene transfer.Exobiology Program (U.S.) (Grant NNX08AQ10G)Assembling the Tree of Life (Program) (Grant DEB 0830024

The impact of inpatient suicide on psychiatric nurses and their need for support

<p>Abstract</p> <p>Background</p> <p>The nurses working in psychiatric hospitals and wards are prone to encounter completed suicides. The research was conducted to examine post-suicide stress in nurses and the availability of suicide-related mental health care services and education.</p> <p>Methods</p> <p>Experiences with inpatient suicide were investigated using an anonymous, self-reported questionnaire, which was, along with the Impact of Event Scale-Revised, administered to 531 psychiatric nurses.</p> <p>Results</p> <p>The rate of nurses who had encountered patient suicide was 55.0%. The mean Impact of Event Scale-Revised (IES-R) score was 11.4. The proportion of respondents at a high risk (≥ 25 on the 88-point IES-R score) for post-traumatic stress disorder (PTSD) was 13.7%. However, only 15.8% of respondents indicated that they had access to post-suicide mental health care programmes. The survey also revealed a low rate of nurses who reported attending in-hospital seminars on suicide prevention or mental health care for nurses (26.4% and 12.8%, respectively).</p> <p>Conclusions</p> <p>These results indicated that nurses exposed to inpatient suicide suffer significant mental distress. However, the low availability of systematic post-suicide mental health care programmes for such nurses and the lack of suicide-related education initiatives and mental health care for nurses are problematic. The situation is likely related to the fact that there are no formal systems in place for identifying and evaluating the psychological effects of patient suicide in nurses and to the pressures stemming from the public perception of nurses as suppliers rather than recipients of health care.</p

Path Following for Mobile Manipulators

This is a post-peer-review, pre-copyedit version of an article published in Robotics Research. The final authenticated version is available online at: http://dx.doi.org/https://doi.org/10.1007/978-3-319-60916-4_30This paper presents a framework of path following via set stabilization for mobile manipulator systems. The mobile manipulator is modelled as a single redundant dynamic system. The mobile base considered belongs to a large class of wheeled ground vehicles, including those with nonholonomic constraints. Kinematic redundancies are resolved by designing a controller that solves a suitably defined constrained quadratic optimization problem, which can be easily tuned by the designer to achieve various desired poses. By employing partial feedback linearization, the proposed path following controller has a clear physical meaning. The desired path to be followed is a spline in the output space of the system. The controller simultaneously controls the manipulator and mobile base. The result is a unified path following controller without any trajectory planning performed on the mobile base. The approach is experimentally verified on a 4-degree-of-freedom (4-DOF) manipulator mounted on a differential drive mobile platfor

Ubiquitin sets the timer: impacts on aging and longevity

Protein homeostasis is essential for cellular function, organismal growth and viability. Damaged and aggregated proteins are turned over by two major proteolytic routes of the cellular quality-control pathways: the ubiquitin-proteasome system and autophagy. For both these pathways, ubiquitination provides the recognition signal for substrate selection. This Commentary discusses how ubiquitin-dependent proteolytic pathways are coordinated with stress- and aging-induced signals

BranchClust: a phylogenetic algorithm for selecting gene families

BACKGROUND: Automated methods for assembling families of orthologous genes include those based on sequence similarity scores and those based on phylogenetic approaches. The first are easy to automate but usually they do not distinguish between paralogs and orthologs or have restriction on the number of taxa. Phylogenetic methods often are based on reconciliation of a gene tree with a known rooted species tree; a limitation of this approach, especially in case of prokaryotes, is that the species tree is often unknown, and that from the analyses of single gene families the branching order between related organisms frequently is unresolved. RESULTS: Here we describe an algorithm for the automated selection of orthologous genes that recognizes orthologous genes from different species in a phylogenetic tree for any number of taxa. The algorithm is capable of distinguishing complete (containing all taxa) and incomplete (not containing all taxa) families and recognizes in- and outparalogs. The BranchClust algorithm is implemented in Perl with the use of the BioPerl module for parsing trees and is freely available at . CONCLUSION: BranchClust outperforms the Reciprocal Best Blast hit method in selecting more sets of putatively orthologous genes. In the test cases examined, the correctness of the selected families and of the identified in- and outparalogs was confirmed by inspection of the pertinent phylogenetic trees

Genomic fluidity: an integrative view of gene diversity within microbial populations

<p>Abstract</p> <p>Background</p> <p>The dual concepts of pan and core genomes have been widely adopted as means to assess the distribution of gene families within microbial species and genera. The core genome is the set of genes shared by a group of organisms; the pan genome is the set of all genes seen in any of these organisms. A variety of methods have provided drastically different estimates of the sizes of pan and core genomes from sequenced representatives of the same groups of bacteria.</p> <p>Results</p> <p>We use a combination of mathematical, statistical and computational methods to show that current predictions of pan and core genome sizes may have no correspondence to true values. Pan and core genome size estimates are problematic because they depend on the estimation of the occurrence of rare genes and genomes, respectively, which are difficult to estimate precisely because they are rare. Instead, we introduce and evaluate a robust metric - genomic fluidity - to categorize the gene-level similarity among groups of sequenced isolates. Genomic fluidity is a measure of the dissimilarity of genomes evaluated at the gene level.</p> <p>Conclusions</p> <p>The genomic fluidity of a population can be estimated accurately given a small number of sequenced genomes. Further, the genomic fluidity of groups of organisms can be compared robustly despite variation in algorithms used to identify genes and their homologs. As such, we recommend that genomic fluidity be used in place of pan and core genome size estimates when assessing gene diversity within genomes of a species or a group of closely related organisms.</p