A Canonical Approach to Duality Transformations

We show that Buscher's abelian duality transformation rules can be recovered in a very simple way by performing a canonical transformation first suggested by Giveon, Rabinovici and Veneziano. We explore the properties of this transformation, and also discuss some aspects of non-abelian duality.Comment: 11 p, LaTex, preprint CERN-TH-7337/94 (some comments and references added

Estudio y análisis de métodos de inferencia filogenética: del ADN a las proteínas

Los principales objetivos de este proyecto fin de carrera son la traducción de ADN a proteínas, la construcción de árboles filogenéticos utilizando proteínas y su comparación con los árboles construidos directamente a partir de secuencias completas de ADN. La filogenética es la disciplina que estudia las relaciones evolutivas entre distintos individuos o especies. El ADN mitocondrial es un tipo especial de ADN que está almacenado en unos orgánulos de la célula llamados mitocondrias. Parte del ADN mitocondrial codifica proteínas. Los árboles filogenéticos se construyen utilizando modelos matemáticos que intentan explicar la evolución real de los individuos. En el caso tratado de ADN mitocondrial, las filogenias son especialmente útiles a la hora de diagnosticar las mutaciones de un paciente como patógenas. Para poder construir estos árboles es necesario identificar las proteínas dentro de la secuencia de ADN mitocondrial y extraer su información. Debido a la falta de homogeneidad en las bases de datos donde se encuentran almacenadas las secuencias es necesaria una primera fase de procesamiento para así poder localizar las proteínas. La comparación de árboles filogenéticos es un tema abierto y candente en la filogenia computacional para el que no se conocen en la actualidad soluciones satisfactorias, por lo que las herramientas existentes no permiten un análisis profundo de los resultados. Futuros desarrollos en el área de comparación de filogenias serán el punto de partida de posteriores investigaciones a partir de las herramientas y resultados obtenidos en este PFC. En este proyecto se trabaja con árboles filogenéticos construidos mediante proteínas, un tema novedoso en investigación por lo que se espera publicar los resultados en breve y que este proyecto sea el punto de partida de futuros estudios. Durante todo el proyecto se ha tenido que dedicar mucho tiempo a la formación en temas de índole biológica. También se ha usado gran cantidad de herramientas bioinformáticas. Se ha conseguido el objetivo de construir los árboles correspondientes a un total de 4.824 secuencias, un número considerado alto en filogenia computacional dado el gran coste computacional de los métodos empleados. Tras compararlos con los árboles de ADN disponibles se ha llegado a la conclusión que son muy distintos, hecho que puede tener varias explicaciones biológicas y que da pie a nuevas investigaciones para dar explicaciones a este suceso

On Non-Abelian Duality

A general study of non-abelian duality is presented. We first identify a possible obstruction to the conformal invariance of the dual theory for non-semisimple groups. We construct the exact non-abelian dual for any Wess-Zumino-Witten (WZW) model for any anomaly free subgroup, and the corresponding extension for coset conformal field theories. We characterize the exact non-abelian dual for $\sigma$-models with chiral isometries and extend the standard notion of duality to anomalous subgroups of WZW models, thus giving a way of constructing dual transformations for different groups on the left and on the right. We also present some new examples of non-abelian duality for four-dimensional gravitational instantons.Comment: 34 p, LaTex, preprint CERN-TH-7204/94, problems with the generation of ps and pdf solve

Do ecological characteristics drive the prevalence of Panulirus argus virus 1 (PaV1) in juvenile Caribbean spiny lobsters in a tropical reef lagoon?

PaV1 is a pathogenic virus found only to infect Caribbean spiny lobsters Panulirus argus, a major fishing resource. P. argus is a benthic mesopredator and has a complex life history, with several ontogenetic habitat changes. Habitat characteristics and species diversity of surrounding communities may have implications for disease dynamics. This is of more concern for juvenile lobsters, which are more susceptible to PaV1 and are far less mobile than adult lobsters. We targeted a population of juvenile P. argus in a reef lagoon in Mexico, where PaV1 was first observed in 2001. Prevalence has been since irregularly assessed, but in 2016 we began a more systematic assessment, with two sampling periods per year (June and November) in three different zones of the reef lagoon. To examine the relationship between PaV1 prevalence and potential ecological determinants, we assessed habitat complexity, cover of different substrates, and invertebrate community composition in all zones during the first four sampling periods (June and November 2016 and 2017). Habitat complexity and percent cover of some substrates varied with zone and sampling period. This was the case for seagrass and macroalgae, which nevertheless were the dominant substrates. The invertebrate community composition varied with sampling period, but not with zone. Probability of infection decreased with increasing lobster size, consistent with previous studies, but was not affected by zone (i.e., variations in ecological characteristics did not appear to be sufficiently large so as to influence prevalence of PaV1). This result possibly reflects the dominance of marine vegetation and suggests that lobsters can be sampled throughout the reef lagoon to assess PaV1 prevalence. Prevalence was higher in only one of seven sampling periods (November 2017), suggesting that the pathogen has leveled off to an enzootic level

Mortality increase after hip fracture in aged patients during the first 6 months of the covid-19 epidemic

Background: The COVID-19 pandemic modified hospital functioning, social mobility and assistance to the elderly. These factors may alter hip fracture evolution. Methods: Retrospective study of patients > 65 years suffering hip fracture fromthe 1st of March to the 31st of August of 2020, and compared with patients from the same period of 2019; 199 patients from 2019 (79.4%women) (mean age: 84.9 ± 7.72 years), and 203 patients from 2020 (69.5%women) (mean age: 85.37 ± 8.13 years). Extracapsular fractures were 57.3% in 2019, and 58.6% in 2020. Follow-up was made until death or 6 months after surgery. Results: In 2019, 44 patients (22.1%) died in the six postoperative months, and 61 patients (30%) in 2020 (OR 1.513; 95% CI 0.96–2.37; p = 0.199). There were no significant differences in mortality during postfracture hospitalization (11.1% in 2019; 11.82% in 2020) and in the first postoperative month (16.6% in 2019; 22.66% in 2020). Four patients died during hip fracture hospitalization over 8 patients presenting PCR+. In 30 patients SARS-CoV-2 infection was diagnosed during the six months after hip fracture in 13 patients thiswas the cause of death (21.3% of causes). Dementiawas associated with high mortality in patients with a SARS-CoV-2 diagnosis (6 out of 13 patients died with SARS-CoV-2 infection and dementia). Conclusions: An increase in the 6 postoperative months mortality in 2020 compared with the same period in 2019 was observed. An important cause of death was SARS-CoV-2 infection

Evaluación de los factores epidemiológicos como predictores de los resultados postquirúrgicos en patología lumbar degenerativa

Els resultats del tractament quirúrgic per dolor lumbar crònic i patologia degenerativa lumbar, patologies d'elevada prevalença i despesa sanitària, estan afectats per múltiples factors. En aquest treball hem estudiat com les característiques epidemiològiques dels pacients de la nostra població influeixen sobre el canvi de la qualitat de vida, la discapacitat i el dolor després de cirurgies per patologia lumbar degenerativa. Del nostre estudi, d'acord amb la revisió realitzada de la literatura, destaquem que el sexe femení, l'augment edat i la discapacitat laboral permanent són predictors dels resultats postoperatoris de la qualitat de vida i la discapacitat.Los resultados del tratamiento quirúrgico por dolor lumbar crónico y patología degenerativa lumbar, patologías de elevada prevalencia y gasto sanitario, están afectados por múltiples factores. En este trabajo hemos estudiado como las características epidemiológicas de los pacientes de nuestra población influyen sobre el cambio de la calidad de vida, la discapacidad y el dolor tras cirugías por patología lumbar degenerativa. De nuestro estudio, acorde con la revisión de la literatura realizada, destacamos que el sexo femenino, el aumento edad y la discapacidad laboral permanente son predictores de los resultados postoperatorios de la calidad de vida y la discapacidad

Coral Reef Degradation Differentially Alters Feeding Ecology of Co-occurring Congeneric Spiny Lobsters

Caribbean coral reefs are undergoing massive degradation, with local increases of macroalgae and reduction of architectural complexity associated with loss of reef-building corals. We explored whether reef degradation affects the feeding ecology of two co-occurring spiny lobsters: Panulirus guttatus, which is an obligate reef-dweller, and Panulirus argus, which uses various benthic habitats including coral reefs. We collected lobsters of both species from the back-reef zones of two large reefs similar in length (∼1.5 km) but differing widely in level of degradation, at the Puerto Morelos Reef National Park (Mexico). We measured the carapace length (CL) and weight (W) of lobsters, estimated three condition indices (hepatosomatic index, HI; blood refractive index, BRI; and W/CL ratio), and analyzed their stomach contents and stable isotope values (δ15N and δ13C). All lobsters tested negative for the presence of the virus PaV1, which can affect nutritional condition. Stomach contents yielded 72 animal taxa, mainly mollusks and crustaceans, with an average of 35 taxa per species per reef, but with much overlap. In P. guttatus, CL, HI, BRI, and W/CL did not vary with reef, but mean isotopic values did. The isotopic niche of P. guttatus showed little overlap between reefs, reflecting differences in local carbon sources and underlining the habitat specialization of P. guttatus, which exhibited a higher trophic position on the more degraded reef. Overall, the trophic position of P. guttatus was higher than that of P. argus. In P. argus, none of the variables differed between reefs and the isotopic niche was wide and with great overlap between reefs, reflecting the broader foraging ranges of P. argus compared to P. guttatus. Additional isotopic values from 16 P. argus caught at a depth of 25 m in the fore reef suggest that these larger lobsters forage over different habitats and have a higher trophic position than their smaller conspecifics and congeners from the back reef. The feeding ecology of P. argus appears to be less influenced by coral reef degradation than that of P. guttatus, but our results suggest a buffering effect of omnivory against habitat degradation for both lobster species

Extreme wave height events in NW Spain: a combined multi-sensor and model approach

The Galician coast (NW Spain) is a region that is strongly influenced by the presence of low pressure systems in the mid-Atlantic Ocean and the periodic passage of storms that give rise to severe sea states. Since its wave climate is one of the most energetic in Europe, the objectives of this paper were twofold. The first objective was to characterize the most extreme wave height events in Galicia over the wintertime of a two-year period (2015–2016) by using reliable high-frequency radar wave parameters in concert with predictions from a regional wave (WAV) forecasting system running operationally in the Iberia-Biscay-Ireland (IBI) area, denominatedIBI-WAV. The second objective was to showcase the application of satellite wave altimetry (in particular, remote-sensed three-hourly wave height estimations) for the daily skill assessment of the IBI-WAV model product. Special attention was focused on monitoring Ophelia—one of the major hurricanes on record in the easternmost Atlantic—during its 3-day track over Ireland and the UK (15–17 October 2017). Overall, the results reveal the significant accuracy of IBI-WAV forecasts and prove that a combined observational and modeling approach can provide a comprehensive characterization of severe wave conditions in coastal areas and shows the benefits from the complementary nature of both systems

Análisis del comportamiento estructural de uniones de madera sometidas a la acción del fuego

Congreso sobre Construcción con Madera y otros Materiales Lignocelulósicos (LIGNOMAD17), 29 de junio a 1 de julio de 2017, Barcelona (España)En situación de incendio, los elementos estructurales de madera sufren una degradación térmica, provocando una transformación del material y una disminución progresiva de su sección resistente. En este sentido, el comportamiento estructural de los elementos de madera se ve reducido. Sin embargo, esta carbonización del material funciona como aislante térmico, favoreciendo que la zona más interior de la madera no incremente su temperatura de inmediato. En este trabajo se muestra el estudio experimental del comportamiento estructural de uniones de cola de milano redondeada en la madera cuando se encuentran sometidas a la acción de un fuego y a una carga constant

Dinosaur bonebed amber from an original swamp forest soil

Dinosaur bonebeds with amber content, yet scarce, offer a superior wealth and quality of data on ancient terrestrial ecosystems. However, the preserved palaeodiversity and/or taphonomic characteristics of these exceptional localities had hitherto limited their palaeobiological potential. Here, we describe the amber from the Lower Cretaceous dinosaur bonebed of Ariño (Teruel, Spain) using a multidisciplinary approach. Amber is found in both a root layer with amber strictly in situ and a litter layer mainly composed of aerial pieces unusually rich in bioinclusions, encompassing 11 insect orders, arachnids, and a few plant and vertebrate remains, including a feather. Additional palaeontological data¿charophytes, palynomorphs, ostracods¿ are provided. Ariño arguably represents the most prolific and palaeobiologically diverse locality in which fossiliferous amber and a dinosaur bonebed have been found in association, and the only one known where the vast majority of the palaeontological assemblage suffered no or low-grade pre-burial transport. This has unlocked unprecedentedly complete and reliable palaeoecological data out of two complementary windows of preservation¿the bonebed and the amber¿from the same site