Evaluación del estado y composición de la Comunidad Fitoplanctónica de las agua del Mar Menor, Murcia (mayo de 2016)

La preocupación, compartida con todos los ciudadanos, por el deterioro de la laguna en las últimas décadas, nos ha llevado a centrar parte de nuestro esfuerzo investigador en el Mar Menor. En este sentido, los indicadores observados durante el pasado año, parecían adelantar la visualización dramática de la situación actual. Los elementos de tampón y autoprotección de la laguna que hasta el momento se consideraban que podían controlar, en parte, las graves presiones antrópicas, estaban siendo alterados (temperaturas cálidas durante todo el año, alteración en los bloom de medusas habituales los últimos años, disminución de la cobertura del tapiz de Caulerpa prolifera, como especie de gran eficiencia en la retirada de nutrientes, etc) y hacían prever la proximidad de un "colapso ambiental". En esta situación, comenzó la inquietud de colectivos y usuarios en general, entre otros, el colectivo de pescadores. Estos últimos, vieron agravada su preocupación, "como consecuencia de la observación de baba en los últimos meses y la turbidez de las aguas en la época (invierno), que a diferencia de otros años resulta superior". Por ello, la Cofradía de Pescadores de San Pedro del Pinatar, solicitó en el mes de enero y posteriormente el mes de mayo del presente año, la realización de un informe/investigación relativo al estado de las aguas del Mar Menor. Solicitud que fue canalizada en el marco de la Unidad mixta UA-IEO. Tras una primera prospección de las posibles actuaciones llevadas a cabo por las diferentes administraciones competentes, se llegó a la conclusión de que no existía, en ese momento (o al menos de forma pública), ningún equipo de investigación técnico y/o científico que estuviese realizando campañas de muestreo sobre la comunidad fitoplanctónica o parámetros asociados en la laguna. Es por ello que en pro del bien común, se asumió la realización de este estudio. En el mes de febrero, se detectó la presencia de un evento de Floración Algal Nocivo (FAN), dominado por la especie Cylindrotheca closterium. La cual es considerada una especie fitoplanctónica nociva por la producción de mucílagos cuando está presente en elevadas concentraciones, situación observada en las muestras analizadas, y causante de la "baba" descrita por los pescadores. Estos primeros resultados nos llevaron a la realización de una segunda campaña de muestreo, asumida con recursos propios del mismo equipo investigador. Se muestrearon mediante metodología estandarizada, 14 puntos distribuidos de forma regular en toda la laguna, tal y como se explica en el informe adjunto. Los resultados mostraron que todas las muestras poseían una elevada abundancia celular, persistiendo la existencia de un evento de Floración Nociva Algal (FAN). El incremento de dinoflagelados hacía aconsejable un análisis específico de toxinas en el medio y en los organismos afectados. Asumiendo nuestro compromiso y responsabilidad como investigadores de instituciones públicas, y acogiéndonos a las obligaciones marcadas por la Directiva INSPIRE 2007/2/CE y la Ley 19/2013, de 9 de diciembre, de transparencia, acceso a la información pública y buen gobierno, los resultados se hacen públicos. En base a estos resultados las administraciones competentes deberían activar un protocolo de seguimiento con una periodicidad mínima semanal y en el que se llevase a cabo un estudio de la evolución de la comunidad fitoplanctónica, así como análisis específicos de toxinas. Con el fin de poder analizar la evolución del estado de la laguna en estos meses críticos

Commissioning of a synchrotron-based proton beam therapy system for use with a Monte Carlo treatment planning system

This work tackles the commissioning and validation of a novel combination of a synchrotron-based proton beam therapy system (Hitachi, Ltd.) for use with a Monte Carlo treatment planning system (TPS). Four crucial aspects in this configuration have been investigated: (1) Monte Carlo-based correction performed by the TPS to the measured integrated depth-dose curves (IDD), (2) circular spot modelling with a single Gaussian function to characterize the synchrotron physical spot, which is elliptical, (3) the modelling of the range shifter that enables using only one set of measurements in open beams, and (4) the Monte Carlo dose calculation model in small fields. Integrated depth-dose curves were measured with a PTW Bragg peak chamber and corrected, with a Monte Carlo model, to account for energy absorbed outside the detector. The elliptical spot was measured by IBA Lynx scintillator, EBT3 films and PTW microDiamond. The accuracy of the TPS (RayStation, RaySearch Laboratories) at spot modelling with a circular Gaussian function was assessed. The beam model was validated using spread-out Bragg peak (SOBP) fields. We took single-point doses at several depths through the central axis using a PTW Farmer chamber, for fields between 2 × 2cm and 30 × 30cm. We checked the range-shifter modelling from open-beam data. We tested clinical cases with film and an ioni- zation chamber array (IBA Matrix). Sigma differences for spots fitted using 2D images and 1D profiles to elliptical and circular Gaussian models were below 0.22 mm. Differences between SOBP measurements at single points and TPS calculations for all fields between 5 × 5 and 30 × 30cm were below 2.3%. Smaller fields had larger differences: up to 3.8% in the 2 × 2cm field. Mean differences at several depths along the central axis were generally below 1%. Differences in range- shifter doses were below 2.4%. Gamma test (3%, 3 mm) results for clinical cases were generally above 95% for Matrix and film. Approaches for modelling synchrotron proton beams have been validated. Dose values for open and range- shifter fields demonstrate accurate Monte Carlo correction for IDDs. Elliptical spots can be successfully modelled using a circular Gaussian, which is accurate for patient calculations and can be used for small fields. A double-Gaussian spot can improve small-field calculations. The range-shifter modelling approach, which reduces clinical commissioning time, is adequat

Under pressure: phenotypic divergence and convergence associated with microhabitat adaptations in Triatominae.

BACKGROUND: Triatomine bugs, the vectors of Chagas disease, associate with vertebrate hosts in highly diverse ecotopes. It has been proposed that occupation of new microhabitats may trigger selection for distinct phenotypic variants in these blood-sucking bugs. Although understanding phenotypic variation is key to the study of adaptive evolution and central to phenotype-based taxonomy, the drivers of phenotypic change and diversity in triatomines remain poorly understood. METHODS/RESULTS: We combined a detailed phenotypic appraisal (including morphology and morphometrics) with mitochondrial cytb and nuclear ITS2 DNA sequence analyses to study Rhodnius ecuadoriensis populations from across the species' range. We found three major, naked-eye phenotypic variants. Southern-Andean bugs primarily from vertebrate-nest microhabitats (Ecuador/Peru) are typical, light-colored, small bugs with short heads/wings. Northern-Andean bugs from wet-forest palms (Ecuador) are dark, large bugs with long heads/wings. Finally, northern-lowland bugs primarily from dry-forest palms (Ecuador) are light-colored and medium-sized. Wing and (size-free) head shapes are similar across Ecuadorian populations, regardless of habitat or phenotype, but distinct in Peruvian bugs. Bayesian phylogenetic and multispecies-coalescent DNA sequence analyses strongly suggest that Ecuadorian and Peruvian populations are two independently evolving lineages, with little within-lineage phylogeographic structuring or differentiation. CONCLUSIONS: We report sharp naked-eye phenotypic divergence of genetically similar Ecuadorian R. ecuadoriensis (nest-dwelling southern-Andean vs palm-dwelling northern bugs; and palm-dwelling Andean vs lowland), and sharp naked-eye phenotypic similarity of typical, yet genetically distinct, southern-Andean bugs primarily from vertebrate-nest (but not palm) microhabitats. This remarkable phenotypic diversity within a single nominal species likely stems from microhabitat adaptations possibly involving predator-driven selection (yielding substrate-matching camouflage coloration) and a shift from palm-crown to vertebrate-nest microhabitats (yielding smaller bodies and shorter and stouter heads). These findings shed new light on the origins of phenotypic diversity in triatomines, warn against excess reliance on phenotype-based triatomine-bug taxonomy, and confirm the Triatominae as an informative model system for the study of phenotypic change under ecological pressure

Correction to: Under pressure: phenotypic divergence and convergence associated with microhabitat adaptations in Triatominae.

An amendment to this paper has been published and can be accessed via the original article

Charge separation relative to the reaction plane in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}= 2.76 TeV

Measurements of charge dependent azimuthal correlations with the ALICE detector at the LHC are reported for Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV. Two- and three-particle charge-dependent azimuthal correlations in the pseudo-rapidity range $|\eta| < 0.8$ are presented as a function of the collision centrality, particle separation in pseudo-rapidity, and transverse momentum. A clear signal compatible with a charge-dependent separation relative to the reaction plane is observed, which shows little or no collision energy dependence when compared to measurements at RHIC energies. This provides a new insight for understanding the nature of the charge dependent azimuthal correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286

A note on comonotonicity and positivity of the control components of decoupled quadratic FBSDE

In this small note we are concerned with the solution of Forward-Backward Stochastic Differential Equations (FBSDE) with drivers that grow quadratically in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem is a comparison result that allows comparing componentwise the signs of the control processes of two different qgFBSDE. As a byproduct one obtains conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio