8,516 research outputs found

    Further constraints on the optical transmission spectrum of HAT-P-1b

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    We report on novel observations of HAT-P-1 aimed at constraining the optical transmission spectrum of the atmosphere of its transiting Hot-Jupiter exoplanet. Ground-based differential spectrophotometry was performed over two transit windows using the DOLORES spectrograph at the Telescopio Nazionale Galileo (TNG). Our measurements imply an average planet to star radius ratio equal to Rp/R\rm R_p/R_{\star}=(0.1159±\pm0.0005). This result is consistent with the value obtained from recent near infrared measurements of this object but differs from previously reported optical measurements being lower by around 4.4 exoplanet scale heights. Analyzing the data over 5 different spectral bins 600\AA\, wide we observed a single peaked spectrum (3.7 σ\rm\sigma level) with a blue cut-off corresponding to the blue edge of the broad absorption wing of sodium and an increased absorption in the region in between 6180-7400\AA. We also infer that the width of the broad absorption wings due to alkali metals is likely narrower than the one implied by solar abundance clear atmospheric models. We interpret the result as evidence that HAT-P-1b has a partially clear atmosphere at optical wavelengths with a more modest contribution from an optical absorber than previously reported.Comment: Accepted by Ap

    Optical detection of the radio supernova SN 2000ft in the circumnuclear region of the luminous infrared galaxy NGC 7469

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    SN 2000ft is detected in two independent Planetary Camera images (F547W and F814W) taken May 13, 2000, about two months before the predicted date of the explosion (July 19, 2000), based on the analysis of its radio light evolution by Alberdi and collaborators. The apparent optical magnitudes and red color of SN 2000ft indicate that it is observed through an extinction of at least AV_V= 3.0 magnitudes. The extinction corrected lower limit to the absolute visual magnitude (MV_V \leq - 18.0), identifies SN 2000ft as a luminous supernova in the optical, as other luminous radio supernovae before. SN 2000ft exploded in a region located at only 0.1 arcsec (i.e. 34 +/- 3 pc) west of a faint cluster (C24). No parent cluster is identified within the detection limits of the HST short exposures. The unambiguous detection of SN 2000ft in the visual shows that multi-epoch sub-arcsecond (FWHM less than 0.1 arcsec) optical imaging is also a valid tool that should be explored further to detect supernovae in the dusty (circum)nuclear regions of (U)LIRGs

    Parkin truncating variants result in a loss-of-function phenotype

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    Parkinson disease (PD) is the second most common neurodegenerative disorder. Most cases of PD are sporadic, while 5–10% have a known genetic basis. Variants in the PARK2 gene are the most frequent cause of autosomal recessive juvenile-onset PD. PARK2 encodes parkin, a multi-domain protein that functions as an ubiquitin E3 ligase. Numerous variants spanning all parkin domains have been identified, although the pathogenic relevance for several of those remains unclear. In this study, we aimed to functionally characterize two truncating parkin variants: N52Mfs*29, which is highly prevalent in the Portuguese and Spanish populations, and L358Rfs*77, recently identified in the Portuguese population. Our results indicate that both variants are prematurely degraded by the proteasome, even though proteins levels are still moderate. We also showed that they are aggregation-prone and lead to mislocalized parkin. Interestingly, the L358Rfs*77 variant is mislocalized to the nucleus, which was never reported for parkin variants. While N52Mfs*29 impaired self-ubiquitination activity, the L358Rfs*77 variant seemed to retain it. Both variants, however, fail to ubiquitinate p62 substrate and did not relocalize to depolarized mitochondria. Therefore, we conclude that parkin truncating variants cause loss of parkin function, thus showing their causative role in PD pathogenesis.This work was funded by FEDER funds through the Programa Operacional Factores de Competitividade – COMPETE 2020 and by Nacional funds through the Fundação para a Ciência e Tecnologia - FCT [COMPETE: POCI-01-0145-FEDER-007440]. This work was also funded in part by the FCT grant FCT-ANR/BEX-GMG/0008/2013 and the Porto Neurosciences and Neurologic Disease Research Initiative at the i3S (Norte-01-0145-FEDER-000008), supported by Norte Portugal Regional Operational Programme (NORTE 2020) under the PORTUGAL 2020 Partnership Agreement, also through FEDER. The authors also acknowledge the support of the i3S Scientific Platform Advanced Light Microscopy, member of the PPBI (PPBI-POCI-01-0145-FEDER-022122). MS, SM and CP were the recipients of fellowships (SFRH/BPD/116046/2016, SFRH/ BD/87189/2012 and SFRH/BD/90048/2012) from the FCT supported by POPH/MCTES funding

    Understanding the 8 micron vs. Pa-alpha relationship on sub-arcsecond scales in Luminous Infrared Galaxies

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    This work explores in detail the relation between the 8 micron and the Pa-alpha emissions for 122 HII regions identified in a sample of 10 low-z LIRGs with nearly constant metallicity (12 + log (O/H) ~ 8.8). We use Gemini/T-ReCS high-spatial resolution (<~ 0.4" ~ 120 pc for the average distance of 60 Mpc of our sample) mid-infrared imaging (at 8.7 micron or 10.3 micron) together with HST/NICMOS continuum and Pa-alpha images. The LIRG HII regions extend the L_8micron vs. L_Pa-alpha relation found for HII knots in the high-metallicity SINGS galaxies by about two orders of magnitude to higher luminosities. Since the metallicity of the LIRG sample is nearly constant, we can rule out this effect as a cause for the scatter seen in the relationship. In turn, it is attributed to two effects: age and PAH features. The L_8micron/L_Pa-alpha ratio, which varies by a factor of ten for the LIRG HII regions, is reproduced by a model with instantaneous star formation and ages ranging from ~ 4 to 7.5 Myr. The remaining dispersion around the model predictions for a given age is probably due to differential contributions of the PAH features (the 8.6 micron, in our case) to the 8 micron emission from galaxy to galaxy.Comment: 16 pages, 9 figures, accepted for publication in ApJ; paper with full-resolution figures can be found at: http://damir.iem.csic.es/extragalactic

    A High Spatial Resolution Mid-Infrared Spectroscopic Study of the Nuclei and Star-Forming Regions in Luminous Infrared Galaxies

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    We present a high spatial (diffraction-limited) resolution (~0.3") mid-infrared (MIR) spectroscopic study of the nuclei and star-forming regions of 4 local luminous infrared galaxies (LIRGs) using T-ReCS on the Gemini South telescope. We investigate the spatial variations of the features seen in the N-band spectra of LIRGs on scales of ~100 pc, which allow us to separate the AGN emission from that of the star formation (SF). We compare our Gemini T-ReCS nuclear and integrated spectra of LIRGs with those obtained with Spitzer IRS. The 9.7um silicate absorption feature is weaker in the nuclei of the LIRGs than in the surrounding regions. This is probably due to the either clumpy or compact environment of the central AGN or young, nuclear starburst. We find that the [NeII] luminosity surface density is tightly and directly correlated with that of Pa-alpha for the LIRG star-forming regions (slope of 1.00+-0.02). Although the 11.3um PAH feature shows also a trend with Pa-alpha, this is not common for all the regions. We also find that the [NeII]\Pa-alpha ratio does not depend on the Pa-alpha equivalent width (EW), i.e., on the age of the ionizing stellar populations, suggesting that, on the scales probed here, the [NeII] emission line is a good tracer of the SF activity in LIRGs. On the other hand, the 11.3um PAH\Pa-alpha ratio increases for smaller values of the Pa-alpha EW (increasing ages), indicating that the 11.3um PAH feature can also be excited by older stars than those responsible for the Pa-alpha emission. Additional high spatial resolution observations are essential to investigate, in a statistical way, the star formation in local LIRGs at the smallest scales and to probe ultimately whether they share the same physical properties as high-z LIRGs, ULIRGs and submillimiter galaxies.Comment: 23 pages (apjstyle), 19 figures, accepted for publicacion in Ap

    Autentificación de carne y productos cárnicos procedentes de codorniz, faisán, perdiz y pintada mediante una técnica de PCR con cebadores especie-específicos

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    Polymerase chain reaction (PCR) based on oligonucleotide primers targeting the mitochondrial 12S rRNA gene has been applied to the specific identification of meats from quail (Coturnix coturnix), pheasant (Phasianus colchicus), partridge (Alectoris spp), and guinea fowl (Numida meleagris)

    Repostaje en tierra de un avión mediante algoritmos genéticos

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    [Resumen] En este trabajo se presenta una solución alternativa, basada en técnicas de la inteligencia artificial, al problema de la gestión de la distribución de combustible dentro de una aeronave comercial. En concreto se ha abordado el repostaje de la aeronave antes de un vuelo. El repostaje en tierra consiste en decidir la cantidad de combustible que se dispondrá en cada depósito atendiendo a criterios de seguridad, estabilidad del avión y eficiencia energética. Para ello se define un problema de optimización cuya función de coste nace del conocimiento específico de los factores que influyen en una aeronave que tiene relación con el posicionamiento del combustible. Después su resolución se realiza mediante algoritmos genéticos. Los resultados obtenidos en simulación mejoran la solución manual estándar que se viene aplicando.Ministerio de Economía y Competitividad; DPI2015-71320-RED

    Complex movement disorders in Ataxia with oculomotor apraxia type 1: Beyond the cerebellar syndrome

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    Background: Ataxia with oculomotor apraxia (AOA1) is characterized by early-onset progressive cerebellar ataxia with peripheral neuropathy, oculomotor apraxia and hypoalbuminemia and hypercholesterolemia. Case Report: A 23-year-old previously healthy woman presented with slowly-progressive gait impairment since the age of six years. Neurological examination revealed profound areflexia, chorea, generalized dystonia and oculomotor apraxia. Brain MRI revealed mild cerebellar atrophy and needle EMG showed axonal sensorimotor neuropathy. Whole exome sequencing revealed a mutation in the aprataxin gene. Discussion: AOA1 can present with choreoathetosis mixed with dystonic features, resembling ataxia-telangiectasia. This case is instructive since mixed and complex movement disorders is not very common in AOA1. Highlights: • Ataxia with oculomotor apraxia type 1 (AOA1) is characterized by early-onset ataxia and oculomotor apraxia caused by variants in the APTX gene. • Ataxia is usually not the sole movement abnormality in AOA1. • Hyperkinetic movement disorders, especially chorea and dystonia, may occur. • Mixed and complex movement disorders is not very common in AOA1. • Patients with early-onset ataxia associated with mixed movement disorders should also be investigated for AOA1

    21cm Cosmology

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    The HARPS search for southern extra-solar planets XXXII. Only 4 planets in the Gl~581 system

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    The Gl 581 planetary system has generated wide interest, because its 4 planets include both the lowest mass planet known around a main sequence star other than the Sun and the first super-Earth planet in the habitable zone of its star. A recent paper announced the possible discovery of two additional super-Earth planets in that system, one of which would be in the middle of the habitable zone of Gl 581. The statistical significance of those two discoveries has, however, been questioned. We have obtained 121 new radial velocity measurements of Gl 581 with the HARPS spectrograph on the ESO 3.6 m telescope, and analyse those together with our previous 119 measurements of that star to examine these potential additional planets. We find that neither is likely to exist with their proposed parameters. We also obtained photometric observations with the 2.5 m Isaac Newton Telescope during a potential transit of the inner planet, Gl 581e, which had a 5% geometric transit probability. Those observations exclude transits for planet densities under 4 times the Earth density within -0.2 sigma to +2.7 sigma of the predicted transit center.Comment: Submitted to Astronomy & Astrophysic
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