Counterpart candidates to the unidentified Fermi source 0FGL J1848.6-0138

Aims: We aim to contribute to the identification of the counterpart for one of the bright sources of gamma-rays in the catalogue obtained and released by the Fermi collaboration. Methods: Our work is based on a extensive identification of sources from different wavelength catalogues and databases. Results: As a first result, we report the finding of a few counterpart candidates inside the 95% confidence error box of the Fermi LAT unidentified gamma-ray source 0FGL J1848.6-0138. The globular cluster GLIMPSE-C01 is remarkably distinctive being among the most peculiar objects consistent with both the position uncertainty in the gamma-ray source and a conceivable physical scenario for gamma-ray production. The Fermi-observed spectrum is compared with theoretical predictions in the literature and the association is found to be plausible but not yet certain because of its low X-ray to gamma-ray luminosity ratio. Other competing counterparts are also discussed. In particular, we pay special attention to a possible Pulsar Wind Nebula inside the Fermi error box, whose nature is yet to be confirmed. Conclusions: Both a globular cluster and an infrared source resembling a Pulsar Wind Nebula were found to be in positional agreement with 0FGL J1848.6-0138. In addition, other interesting objects in the field are also reported. Future gamma-ray observations will reduce the position uncertainty and we hope eventually confirm one of the counterpart candidates reported here. If GLIMPSE-C01 is confirmed together with the possible Fermi detection of the well known globular cluster 47 Tuc, then this would provide strong support to theoretical predictions that globular clusters are possible gamma-ray sources.Facultad de Ciencias Astronómicas y Geofísica

Improved linkage analysis of Quantitative Trait Loci using bulk segregants unveils a novel determinant of high ethanol tolerance in yeast

Background: Bulk segregant analysis (BSA) coupled to high throughput sequencing is a powerful method to map genomic regions related with phenotypes of interest. It relies on crossing two parents, one inferior and one superior for a trait of interest. Segregants displaying the trait of the superior parent are pooled, the DNA extracted and sequenced. Genomic regions linked to the trait of interest are identified by searching the pool for overrepresented alleles that normally originate from the superior parent. BSA data analysis is non-trivial due to sequencing, alignment and screening errors. Results: To increase the power of the BSA technology and obtain a better distinction between spuriously and truly linked regions, we developed EXPLoRA (EXtraction of over-rePresented aLleles in BSA), an algorithm for BSA data analysis that explicitly models the dependency between neighboring marker sites by exploiting the properties of linkage disequilibrium through a Hidden Markov Model (HMM). Reanalyzing a BSA dataset for high ethanol tolerance in yeast allowed reliably identifying QTLs linked to this phenotype that could not be identified with statistical significance in the original study. Experimental validation of one of the least pronounced linked regions, by identifying its causative gene VPS70, confirmed the potential of our method. Conclusions: EXPLoRA has a performance at least as good as the state-of-the-art and it is robust even at low signal to noise ratio's i.e. when the true linkage signal is diluted by sampling, screening errors or when few segregants are available

Modificaciones funcionales, personales y sociales de las fracturas de la extremidad proximal del fémur en pacientes mayores

Se ha realizado un estudio retrospectivo revisando las historias clínicas de 550 pacientes mayores de 69 años que sufrieron una fractura de cadera durante 1995 y 1996 en Salamanca. Cerca de la mitad de los pacientes estudiados tenían independencia casi total y el 40.22% cambió su tipo de residencia. La mayoría de los pacientes perdieron actividad y se encontraron diferencias estadísticamente significativas en la existencia o no de complicaciones. Casi todas las fracturas ocurrieron tras una caída casual por tropiezos o resbalones. El 57.67% de los pacientes tenían una intensa osteopenia. Alrededor del 25% de los pacientes realizaron rehabilitación, sobre todo los tratados con enclavados endomedulares. La mortalidad fue de 31.37% y se encontraron diferencias estadísticamente significativas al relacionarla con la actividad física previa y postratamiento y el grado de dependencia previa a la fractura. Estos cambios en la función y dependencia, tienen poca influencia en la rehabilitación y mortalidad de los pacientes.Case-history reviews and at-home interviews we used to study retrospectively the 550 patients older than 69 years who suffered a hip fracture between 1995 and 1996 in Salamanca (Spain). The average hospitalization time was 15 days. Almost half of patients were not dependent at all and 40.22% of them moved to another residence. Most patients lost activity, and it was statistically correlated to the adverse events reported. Almost every fracture occurred after a casual fall due to stumbling or sliding. 57.67 % of patients had a severe osteopenia. The most frequent fracture reported was pertrochanteric (44.67%) followed by subcapital, especially those treated with intramedullary nailing. Mortality was 31.37% and statistical differences were found between degree of activity before and after the fracture. These changes in function and type of residence have a scarce influence on rehabilitation and mortality of patients

Pliocene sigmodontine rodents (Mammalia: Cricetidae) in northernmost South America: test of biogeographic hypotheses and revised evolutionary scenarios

We document the first occurrence of Sigmodontinae (Mammalia, Rodentia, Cricetidae) from the Pliocene of northern South America, from the San Gregorio Formation of northwestern Venezuela. The recovered isolated molars are identified as Oligoryzomys sp. and Zygodontomys sp., two currently widespread sigmodontines in South America. These records constitute the oldest representatives of these genera, potentially new species, and the first Pliocene occurrence for Oryzomyini and the whole subfamily outside Argentina. Hypotheses on the historical biogeography of sigmodontines have been constructed almost exclusively using genetic data and the fossils we report provide a new kind of evidence. The occurrence of Oligoryzomys sp. and Zygodontomys sp. in Venezuela provides novel information for the diversification models suggested for Oligoryzomys, by supporting a potential eastern corridor of open environments from northern to southern South America. The presence of sigmodontines from the locality home of the new reports, Norte Casa Chiguaje, is consistent with the palaeoenvironmental conditions originally proposed for it based on mammals and botanical records, being characterized as mixed open grassland/forest areas surrounding permanent freshwater systems. The new sigmodontine evidence is used to discuss the putative scenarios of the ancient evolution of the subfamily in South America, favouring a model in which open areas (savannahs) to the east of the Andes played crucial role aiding or obstructing Late Miocene-Pliocene sigmodontine dispersion southwards

Candidate counterparts to the soft gamma-ray flare in the direction of LS i +61 303

Context. A short duration burst reminiscent of a soft gamma-ray repeater/anomalous X-ray pulsar behaviour was detected in the direction of LS I +61 303 by the Swift satellite. While the association with this well known gamma-ray binary is likely, a different origin cannot be excluded. Aims. We explore the error box of this unexpected flaring event and establish the radio, near-infrared and X-ray sources in our search for any peculiar alternative counterpart. Methods. We carried out a combined analysis of archive Very Large Array radio data of LS I +61 303 sensitive to both compact and extended emission. We also reanalysed previous near infrared observations with the 3.5 m telescope of the Centro Astronómico Hispano Alemn and X-ray observations with the Chandra satellite. Results. Our deep radio maps of the LS I +61 303 environment represent a significant advancement on previous work and 16 compact radio sources in the LS I +61 303 vicinity are detected. For some detections, we also identify near infrared and X-ray counterparts. Extended emission features in the field are also detected and confirmed. The possible connection of some of these sources with the observed flaring event is considered. Based on these data, we are unable to claim a clear association between the Swift-BAT flare and any of the sources reported here. However, this study represents the most sophisticated attempt to determine possible alternative counterparts other than LS I +61 303.Facultad de Ciencias Astronómicas y Geofísica

Candidate counterparts to the soft gamma-ray flare in the direction of LS i +61 303

Context. A short duration burst reminiscent of a soft gamma-ray repeater/anomalous X-ray pulsar behaviour was detected in the direction of LS I +61 303 by the Swift satellite. While the association with this well known gamma-ray binary is likely, a different origin cannot be excluded. Aims. We explore the error box of this unexpected flaring event and establish the radio, near-infrared and X-ray sources in our search for any peculiar alternative counterpart. Methods. We carried out a combined analysis of archive Very Large Array radio data of LS I +61 303 sensitive to both compact and extended emission. We also reanalysed previous near infrared observations with the 3.5 m telescope of the Centro Astronómico Hispano Alemn and X-ray observations with the Chandra satellite. Results. Our deep radio maps of the LS I +61 303 environment represent a significant advancement on previous work and 16 compact radio sources in the LS I +61 303 vicinity are detected. For some detections, we also identify near infrared and X-ray counterparts. Extended emission features in the field are also detected and confirmed. The possible connection of some of these sources with the observed flaring event is considered. Based on these data, we are unable to claim a clear association between the Swift-BAT flare and any of the sources reported here. However, this study represents the most sophisticated attempt to determine possible alternative counterparts other than LS I +61 303.Facultad de Ciencias Astronómicas y Geofísica

The star forming region Monoceros R2 as a gamma-ray source

Context. After the release of the gamma-ray source catalog produced by the Fermi satellite during its first two years of operation, a significant fraction of sources still remain unassociated at lower energies. In addition to well-known high-energy emitters (pulsars, blazars, supernova remnants, etc.), theoretical expectations predict new classes of gamma-ray sources. In particular, gamma-ray emission could be associated with some of the early phases of stellar evolution, but this interesting possibility is still poorly understood. Aims. The aim of this paper is to assess the possibility of the Fermi gamma-ray source 2FGL J0607.5-0618c being associated with the massive star forming region Monoceros R2. Methods. A multi-wavelength analysis of the Monoceros R2 region is carried out using archival data at radio, infrared, X-ray, and gamma-ray wavelengths. The resulting observational properties are used to estimate the physical parameters needed to test the different physical scenarios. Results. We confirm the 2FGL J0607.5-0618c detection with improved confidence over the Fermi two-year catalog. We find that a combined effect of the multiple young stellar objects in Monoceros R2 is a viable picture for the nature of the source.Facultad de Ciencias Astronómicas y GeofísicasInstituto Argentino de Radioastronomí

The star forming region Monoceros R2 as a gamma-ray source

Context. After the release of the gamma-ray source catalog produced by the Fermi satellite during its first two years of operation, a significant fraction of sources still remain unassociated at lower energies. In addition to well-known high-energy emitters (pulsars, blazars, supernova remnants, etc.), theoretical expectations predict new classes of gamma-ray sources. In particular, gamma-ray emission could be associated with some of the early phases of stellar evolution, but this interesting possibility is still poorly understood. Aims. The aim of this paper is to assess the possibility of the Fermi gamma-ray source 2FGL J0607.5-0618c being associated with the massive star forming region Monoceros R2. Methods. A multi-wavelength analysis of the Monoceros R2 region is carried out using archival data at radio, infrared, X-ray, and gamma-ray wavelengths. The resulting observational properties are used to estimate the physical parameters needed to test the different physical scenarios. Results. We confirm the 2FGL J0607.5-0618c detection with improved confidence over the Fermi two-year catalog. We find that a combined effect of the multiple young stellar objects in Monoceros R2 is a viable picture for the nature of the source.Facultad de Ciencias Astronómicas y GeofísicasInstituto Argentino de Radioastronomí

Cíes Islands: a wind trap in the Ria of Vigo (Galicia, Spain) at the end of the Last Glacial

Las Islas Cíes han constituido un obstáculo para los intensos vientos costeros del Atlántico Norte, especialmente durante las fases glaciares del Cuaternario. Al final del último glaciar el mar descendió más de 100 m por debajo de su nivel actual. Este descenso transformó el archipiélago en un relieve emergido de 300 m de alto, capaz de deflectar el viento y atraer, al mismo tiempo, sedimentos eólicos procedentes de una franja de plataforma continental también emergida. Bajo esta hipótesis, estos materiales eólicos se depositaron cubriendo el contorno de Cíes. Un ejemplo de estos episodios de acreción eólica es el afloramiento de eolianitas situado en la Isla de Monteagudo (Islas Cíes, Galicia, España), interpretado como una duna rampante que estuvo activa desde el final del Pleistoceno Superior, cubriendo parcialmente la vertiente oriental. Con un espesor de más de 3 metros y una edad (OSL) de 35 ka (b2k) en el muro y de 17 ka en el techo de la formación, este depósito es una prueba de la eolización desarrollada en la costa de Galicia durante miles de años, interrumpida al cesar los aportes durante el postglaciar holocenoCies Islands have been an obstacle to the intense coastal winds from the North Atlantic, especially during the Quaternary glacial cycles. At the end of the Last Glacial period, the local sedimentary-record shows that sea-level decreased more than 100 m below present level. This sea-level drop transformed the archipelago into an emerged relief 300 m high, which probably deflected the wind and, at the same time, was able to capture aeolian sediments coming from a strip of the continental shelf also emerged. Under this hypothesis, these aeolian materials were deposited covering the contour of Cies Islands. An example of these aeolian accretion processes is the eolianites outcrop located at Monteagudo Island (Cies Islands, Galicia, Spain) interpreted as a climbing-dune which was active from the end of the Upper Pleistocene, partially covering the eastern slope. This deposit more than 3 meters thick with an OSL age of 35 ky (b2k) at the base and 17 ky at the top, is an evidence of the aeolisation developed in the Galician coast for thousands of years, finally disrupted when aeolian-supplies were suspended during Holocene post-glacia