4,081 research outputs found

    The Dirichlet Obstruction in AdS/CFT

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    The obstruction for a perturbative reconstruction of the five-dimensional bulk metric starting from the four-dimensional metric at the boundary,that is, the Dirichlet problem, is computed in dimensions 6d106\leq d\leq 10 and some comments are made on its general structure and, in particular, on its relationship with the conformal anomaly, which we compute in dimension d=8d=8.Comment: 13 pages, references added (this paper supersedes hep-th/0206140, "A Note on the Bach Tensor in AdS/CFT", which has been withdrawn

    Experimental measurement of the quality factor of a Fabry-P\'erot open-cavity axion haloscope

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    The axion is a hypothetical boson arising from the most natural solution to the problem of charge and parity symmetry in the strong nuclear force. Moreover, this pseudoscalar emerges as a dark matter candidate in a parameter space extending several decades in mass. The Dark-photons \& Axion-Like particles Interferometer (DALI) is a proposal to search for axion dark matter in a range that remains under-examined. Currently in a design and prototyping phase, this haloscope is a multilayer Fabry-P\'erot interferometer. A proof-of-principle experiment is performed to observe the resonance in a prototype. The test unveils a quality factor per open cavity of a few hundred over a bandwidth of the order of dozens of megahertz. The result elucidates a physics potential to find the, so far elusive, axion, in a sector which can simultaneously solve the symmetry problem in the strong interaction and the enigma of dark matter.Comment: 5 pages, 6 figure

    Adaptación al Español Europeo de la Evaluación Automatizada de la Memoria Operativa (Automated Working Memory Test Battery -AWMA).

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    The current study presents the adaptation of Automated Working Memory Assessment into European Spanish, considering the need of calibration for accent and linguistic issues not supported by the version available. For this purpose, verbal material was carefully and properly selected, considering specificities of the European Spanish, in order to control possible effects of psycholinguistic factors, such as word length or lexical frequency, and technical aspects such as stimuli presentation speed and sound quality were also tuned. An exploratory sample of 81 children from 7- to 9-year-old was assessed to confirm that the adaptation is suitable for further use, besides, their scores were contrasted with the Argentinean children. The data showed proper validity and reliability scores, which characterize this version as a useful instrument for research purposes, and its usage in further studies should be encourage to gather normative data for Spaniards.En el presente estudio se presenta la adaptación al idioma Es-pañol Europeo de la Evaluación Automatizada de la Memoria Operativa, habiéndose tenido en cuenta la necesidad de calibración para cuestiones de acento y lingüística que no son compatibles con la versión disponible. Con este propósito, el material verbal fue seleccionado cuidadosa y apropiada-mente, teniendo en cuenta las especificidades del Español Europeo y con el fin de controlar los posibles efectos de los factores psicolingüísticos, tales como la longitud de las palabras o la frecuencia léxica, y aspectos técnicos, como la velocidad de presentación de los estímulos y la calidad de sonido también fueron controlados. Una muestra exploratoria de 81 niños de 7 a 9 años de edad se evaluó para confirmar que la adaptación es adecuada para su empleo posterior. Además las puntuaciones obtenidas se contrastaron con las de niños argentinos. Los datos mostraron una validez adecuada y una puntuación fiable, lo que permite considerar a esta versión como un instrumento útil para fines de investigación, y su empleo en futuros estu-dios debería incentivar la recopilación de datos normativos para españoles.This research was supported mainly by two grants from the Fundacion Seneca, Murcia Regional Government Agency for Science and Technology (visiting research grant 2010 to Flavia Heloisa Dos Santos and research grant 19463/PI/14), and by a grant from the Spanish Minister of Science and Innovation (research grant PSI2008-03481/PSIC)

    Phylogenomics of \u3ci\u3eTetraopes\u3c/i\u3e longhorn beetles unravels their evolutionary history and biogeographic origins

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    Tetraopes longhorn beetles are known for their resistance to milkweed plant toxins and their coevolutionary dynamics with milkweed plants (Asclepias). This association is considered a textbook example of coevolution, in which each species of Tetraopes is specialized to feed on one or a few species of Asclepias. A major challenge to investigating coevolutionary hypotheses and conducting molecular ecology studies lies in the limited understanding of the evolutionary history and biogeographical patterns of Tetraopes. By integrating genomic, morphological, paleontological, and geographical data, we present a robust phylogeny of Tetraopes and their relatives, using three inference methods with varying subsets of data, encompassing 2–12 thousand UCE loci. We elucidate the diversification patterns of Tetraopes species across major biogeographical regions and their colonization of the American continent. Our findings suggest that the genus originated in Central America approximately 21 million years ago during the Miocene and diversified from the Mid-Miocene to the Pleistocene. These events coincided with intense geological activity in Central America. Additionally, independent colonization events in North America occurred from the Late Miocene to the early Pleistocene, potentially contributing to the early diversification of the group. Our data suggest that a common ancestor of Tetraopini migrated into North America, likely facilitated by North Atlantic land bridges, while closely related tribes diverged in Asia and Europe during the Paleocene. Establishing a robust and densely sampled phylogeny of Tetraopes beetles provides a foundation for investigating micro- and macroevolutionary phenomena, including clinal variation, coevolution, and detoxification mechanisms in this ecologically important group

    Orbital and Physical Properties of the σ Ori Aa, Ab, B Triple System

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    We provide a complete characterization of the astrophysical properties of the σ Ori Aa, Ab, B hierarchical triple system and an improved set of orbital parameters for the highly eccentric σ Ori Aa, Ab spectroscopic binary. We compiled a spectroscopic data set comprising 90 high-resolution spectra covering a total time span of 1963 days. We applied the Lehman-Filhés method for a detailed orbital analysis of the radial velocity curves and performed a combined quantitative spectroscopic analysis of the σ Ori Aa, Ab, B system by means of the stellar atmosphere code FASTWIND. We used our own plus other available information on photometry and distance to the system for measuring the radii, luminosities, and spectroscopic masses of the three components. We also inferred evolutionary masses and stellar ages using the Bayesian code BONNSAI. The orbital analysis of the new radial velocity curves led to a very accurate orbital solution of the σ Ori Aa, Ab pair. We provided indirect arguments indicating that σ Ori B is a fast-rotating early B dwarf. The FASTWIND+BONNSAI analysis showed that the Aa, Ab pair contains the hottest and most massive components of the triple system while σ Ori B is a bit cooler and less massive. The derived stellar ages of the inner pair are intriguingly younger than the one widely accepted for the σ Orionis cluster, at 3 ± 1 Ma. The outcome of this study will be of key importance for a precise determination of the distance to the σ Orionis cluster, the interpretation of the strong X-ray emission detected for σ Ori Aa, Ab, B, and the investigation of the formation and evolution of multiple massive stellar systems and substellar objects.Financial support was provided by the Spanish Ministerio de Ciencia e Innovación and Ministerio de Economía y Competitividad under grants AYA2010-17631, AYA2010-15081, AYA2010-21697-C05-04, AYA2011-30147-C03-03, AYA2012-39364-C02-01/02, and Severo Ochoa SEV-2011-0187, and by the Canary Islands Government under grant PID2010119. R.H.B. acknowledges support from FONDECYT Regular project 1140076. J.S.-B. acknowledges support by the JAE-PreDoc program of the Spanish Consejo Superior de Investigaciones Científicas (CSIC). Á.S. acknowledges support by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences

    Hallazgos histopatológicos en corazón, pulmones y cerebro de ratones expuestos a óxidos de plomo (greta) por vía cutánea.

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    Introducción: México es un país con grandes depósitos naturales de plomo y se estima que el mundo genera alrededor de 12 a 130,000 toneladas/año y su principal vía de introducción al ambiente es por la atmósfera. El propósito del presente trabajo es identificar si existen lesiones en corazón, pulmones y cerebro después de una exposición cutánea al plomo en ratones.   Material y Métodos: Se seleccionaron 40 ratones sanos: 24 machos y 16 hembras; se les aplicó óxido de plomo (GRETA) por vía cutánea y las dosis fueron de 2,4, 6,8 y 10 mg de óxido de plomo. Se aplicó diario de lunes a sábado, estableciendo 5 lotes de 8 ratones en cada grupo; más un grupo control también de 8 ratones. Cada semana se sacrificó un ratón al azar de cada grupo y 5 ratones fallecieron antes de concluir el experimento. De cada órgano se consignó su coloración, tamaño, aspecto externo, fragilidad del tejido en general, tiempo de exposición al plomo y cambios histopatológicos en los tejidos.   Resultados: En los 40 ratones expuestos se presentó congestión pulmonar en grado moderado, en 33 de ellos (82%) se encontró edema pulmonar de tipo no cardiogénico y en 1 existió coágulo de fibrina. En corazón se presentó congestión vascular moderada en el 97% de los ratones (39 de ellos) y en el 5% (2 ratones) se encontró necrosis leve. En el cerebro las alteraciones fueron edema en todos los ratones expuestos, con necrosis neuronal  en el 88% (35 ratones) y gliosis neuronal reactiva en el 10% (4 ratones), con estas alteraciones los ratones perdieron coordinación en sus movimientos.   Discusión: El presente trabajo mostró que el plomo aplicado por vía cutánea es capaz de absorberse. La mayoría de los mecanismos de toxicidad del plomo han sido estudiados en procesos bioquímicos y afectan sobre todo enzimas en procesos celulares. La frecuencia y la severidad de los síntomas médicos se relaciona con la concentración de plomo en la sangre.   Conclusiones: Por la piel la entrada del plomo inorgánico es mínima, pero el plomo orgánico pasa a través de los folículos pilosos, glándulas sebáceas y sudoríparas directo al torrente sanguíneo. El plomo constituye una parte importante de la contaminación ambiental, el empleo de este metal en la industria, hacen necesario que se controle el impacto negativo de sus acciones tanto en la salud de los seres humanos como en el ambiente.Introducción: México es un país con grandes depósitos naturales de plomo y se estima que el mundo genera alrededor de 12 a 130,000 toneladas/año y su principal vía de introducción al ambiente es por la atmósfera. El propósito del presente trabajo es identificar si existen lesiones en corazón, pulmones y cerebro después de una exposición cutánea al plomo en ratones.   Material y Métodos: Se seleccionaron 40 ratones sanos: 24 machos y 16 hembras; se les aplicó óxido de plomo (GRETA) por vía cutánea y las dosis fueron de 2,4, 6,8 y 10 mg de óxido de plomo. Se aplicó diario de lunes a sábado, estableciendo 5 lotes de 8 ratones en cada grupo; más un grupo control también de 8 ratones. Cada semana se sacrificó un ratón al azar de cada grupo y 5 ratones fallecieron antes de concluir el experimento. De cada órgano se consignó su coloración, tamaño, aspecto externo, fragilidad del tejido en general, tiempo de exposición al plomo y cambios histopatológicos en los tejidos.   Resultados: En los 40 ratones expuestos se presentó congestión pulmonar en grado moderado, en 33 de ellos (82%) se encontró edema pulmonar de tipo no cardiogénico y en 1 existió coágulo de fibrina. En corazón se presentó congestión vascular moderada en el 97% de los ratones (39 de ellos) y en el 5% (2 ratones) se encontró necrosis leve. En el cerebro las alteraciones fueron edema en todos los ratones expuestos, con necrosis neuronal  en el 88% (35 ratones) y gliosis neuronal reactiva en el 10% (4 ratones), con estas alteraciones los ratones perdieron coordinación en sus movimientos.   Discusión: El presente trabajo mostró que el plomo aplicado por vía cutánea es capaz de absorberse. La mayoría de los mecanismos de toxicidad del plomo han sido estudiados en procesos bioquímicos y afectan sobre todo enzimas en procesos celulares. La frecuencia y la severidad de los síntomas médicos se relaciona con la concentración de plomo en la sangre.   Conclusiones: Por la piel la entrada del plomo inorgánico es mínima, pero el plomo orgánico pasa a través de los folículos pilosos, glándulas sebáceas y sudoríparas directo al torrente sanguíneo. El plomo constituye una parte importante de la contaminación ambiental, el empleo de este metal en la industria, hacen necesario que se controle el impacto negativo de sus acciones tanto en la salud de los seres humanos como en el ambiente

    The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII): First Flight

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    The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter far-infrared (30-100 m) double-Fourier Michelson interferometer designed to fly on a high altitude scientific balloon. The project began in 2011, and the payload was declared ready for flight in September 2016. Due to bad weather, the first flight was postponed until June 2017; BETTII was successfully launched on June 8, 2017 for an engineering flight. Over the course of the one night flight, BETTII acquired a large amount of technical data that we are using to characterize the payload. Unfortunately, the flight ended with an anomaly that resulted in destruction of the payload. In this paper, we will discuss the path to BETTII flight, the results of the first flight, and some of the plans for the future

    A genome-wide association study follow-up suggests a possible role for PPARG in systemic sclerosis susceptibility

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    Introduction: A recent genome-wide association study (GWAS) comprising a French cohort of systemic sclerosis (SSc) reported several non-HLA single-nucleotide polymorphisms (SNPs) showing a nominal association in the discovery phase. We aimed to identify previously overlooked susceptibility variants by using a follow-up strategy.<p></p> Methods: Sixty-six non-HLA SNPs showing a P value <10-4 in the discovery phase of the French SSc GWAS were analyzed in the first step of this study, performing a meta-analysis that combined data from the two published SSc GWASs. A total of 2,921 SSc patients and 6,963 healthy controls were included in this first phase. Two SNPs, PPARG rs310746 and CHRNA9 rs6832151, were selected for genotyping in the replication cohort (1,068 SSc patients and 6,762 healthy controls) based on the results of the first step. Genotyping was performed by using TaqMan SNP genotyping assays. Results: We observed nominal associations for both PPARG rs310746 (PMH = 1.90 × 10-6, OR, 1.28) and CHRNA9 rs6832151 (PMH = 4.30 × 10-6, OR, 1.17) genetic variants with SSc in the first step of our study. In the replication phase, we observed a trend of association for PPARG rs310746 (P value = 0.066; OR, 1.17). The combined overall Mantel-Haenszel meta-analysis of all the cohorts included in the present study revealed that PPARG rs310746 remained associated with SSc with a nominal non-genome-wide significant P value (PMH = 5.00 × 10-7; OR, 1.25). No evidence of association was observed for CHRNA9 rs6832151 either in the replication phase or in the overall pooled analysis.<p></p> Conclusion: Our results suggest a role of PPARG gene in the development of SSc

    Caribbean Corals in Crisis: Record Thermal Stress, Bleaching, and Mortality in 2005

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    BACKGROUND The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. METHODOLOGY/PRINCIPAL FINDINGS Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. CONCLUSIONS/SIGNIFICANCE Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.This work was partially supported by salaries from the NOAA Coral Reef Conservation Program to the NOAA Coral Reef Conservation Program authors. NOAA provided funding to Caribbean ReefCheck investigators to undertake surveys of bleaching and mortality. Otherwise, no funding from outside authors' institutions was necessary for the undertaking of this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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