313 research outputs found
La raza sayaguesa base de la marca silomaña. Actualidad y posibilidades
La utilización de los pastos de la montaña de León unido a una raza autóctona, la raza sayaguesa, para la obtención de un producto de calidad y diferenciado como es el buey. Nos ha permitido obtener un producto de unas características hasta ahora desconocidas, con un perfil de ácidos grasos mono y poliinsaturados, y unas características físico-químicas que hacen que nuestro producto puede considerarse como un “ALIMENTO FUNCIONAL”
Development of organs and tissues in lambs raised on Spanish mountain grassland
The present study was conducted to establish
the pattern of body development in grass-raised Churra Tensina lambs. Forty-nine single male lambs were slaughtered at
three body-weight intervals, according to the commercial categories of suckling (11.191.0kg), light (22.190.8 kg) and
heavy lamb (32.092.9 kg). Non-carcass and carcass components were recorded and the half left carcasses were completely
dissected. Lambs showed a low growth rate of main organs in relation to empty body weight (BW) (PB0.01). Skin fleece
and liver accompanied the rest of mass growth (P 0.05). The allometric coefficients of forestomachs and large intestine
were higher than that of the small intestine (PB0.05). Joints related to locomotion had early development (PB0.01),
whereas those belonging to the trunk grew at faster rates than did carcass weight (PB0.01). The fatty tissues had increased
growth coefficients (PB0.01), whereas bone and lean coefficients decreased (PB0.01) with increasing carcass weight.
Intermuscular fat attained greater growth rates in lambs slaughtered at light BW than in heavy lambs (PB0.01). However,
the former group displayed lower relative growth of pelvic-renal, subcutaneous and abdominal fat than the latter
(PB0.01). This trait might reflect improved investment of dietary energy towards deposition of adipose tissue through the
increased digestive tract capacity. L’e´tude devait pre´ciser
comment se de´veloppe le corps des agneaux Churra Tensina engraisse´s a` l’herbe. Quarante-neuf agneaux maˆ les ont e´ te´
abattus a` trois poids corporels diffe´rents selon les cate´gories commerciales d’agnelet (11,191,0kg), d’agneau le´ger (22,19
0,8 kg) et d’agneau lourd (32,092,9 kg). Les auteurs ont consigne´ les parties de la carcasse et les autres parties puis
entie`rement disse´que´ le coˆ te´ gauche de la carcasse. Les principaux organes des agneaux croissent lentement
comparativement au poids de la carcasse vide (PB0,01). La peau et la laine ainsi que le foie suivent le reste de
l’accroissement ponde´ ral (P 0,05). Les coefficients allome´triques du secteur gastrique ante´rieur et du gros intestin sont
plus e´leve´ s que ceux de l’intestin greˆ le (PB0,05). Les articulations associe´es a` la locomotion se de´veloppent haˆ tivement
(PB0,01) alors que celles du tronc croissent plus vite que le poids de la carcasse (PB0,01). Les tissus adipeux se
caracte´ risent par un coefficient de croissance plus e´leve´ (PB0,01), tandis que les coefficients des os et de la viande maigre
diminuent (PB0,01) a` mesure que le poids de la carcasse augmente. Le taux de croissance de la graisse intermusculaire est
plus e´leve´ chez les agneaux le´gers que chez les agneaux lourds (PB0,01). Cependant, les sujets du premier groupe re´ve`lent
une plus faible croissance relative de la matie`re grasse pelvique-re´nale, sous-cutane´e et abdominale que ceux du second
groupe (PB0,01). Cette caracte´ristique pourrait traduire une meilleure utilisation de l’e´nergie des aliments pour le de´poˆt de
tissu adipeux graˆ ce a` une capacite´ supe´rieure du tube digestif
Multiwavelength Photometric and Spectropolarimetric Analysis of the FSRQ 3C 279
In this paper, we present light curves for 3C 279 over a time period of six
years; from 2008 to 2014. Our multiwavelength data comprise 1 mm to gamma-rays,
with additional optical polarimetry. Based on the behaviour of the gamma-ray
light curve with respect to other bands, we identified three different activity
periods. One of the activity periods shows anomalous behaviour with no
gamma-ray counterpart associated with optical and NIR flares. Another anomalous
activity period shows a flare in gamma-rays, 1 mm and polarization degree,
however, it does not have counterparts in the UV continuum, optical and NIR
bands. We find a significant overall correlation of the UV continuum emission,
the optical and NIR bands. This correlation suggests that the NIR to UV
continuum is co-spatial. We also find a correlation between the UV continuum
and the 1 mm data, which implies that the dominant process in producing the UV
continuum is synchrotron emission. The gamma-ray spectral index shows
statistically significant variability and an anti-correlation with the
gamma-ray luminosity. We demonstrate that the dominant gamma-ray emission
mechanism in 3C 279 changes over time. Alternatively, the location of the
gamma-ray emission zone itself may change depending on the activity state of
the central engine.Comment: 32 pages, 19 figures, Accepted for publication in MNRA
Singularities of surface mixing activity in the Western Mediterranean influence bluefin tuna larval habitats
Understanding how the surface dynamics of the ocean influence the spawning and larval ecology of many large pelagic species, in particular tuna species, is a major challenge. For temperate tunas, the selection of geographically restricted spawning grounds is influenced by environmental conditions, but the influence of surface mixing properties on the early life stages of these species remains poorly understood. Here, based on ichthyoplankton samples collected over 4 yr and satellite-derived finite size Lyapunov exponents (FSLEs), we examined how horizontal mixing activity drives the probability of presence of Atlantic bluefin tuna Thunnus thynnus larvae. We further analyzed the spatial and temporal scales of the FSLE variability at which the relationship between larval presence and mesoscale activity is maximized. We found that moderate mixing activity strongly favors the spatial-temporal distribution of larval habitats, evidencing an optimal environmental window of bluefin tuna spawning and early life development within the mesoscale dynamics. During the spawning season, the Balearic Sea presents a unique spatial and temporal hydrodynamic scenario within the Western Mediterranean. These results can be used for developing oceanographic indicators and improving larval abundance indices that are currently used in Atlantic bluefin tuna stock assessments.En prensa2,48
MEGADES: MEGARA Galaxy Discs Evolution Survey. Data Release I: central fields
The main interest of the Science Team for the exploitation of the MEGARA
instrument at the 10.4m Gran Telescopio Canarias (GTC hereafter) is devoted to
the study of nearby galaxies, with focus on the research of the history of star
formation, and chemical and kinematical properties of disc systems. We refer to
this project as MEGADES: MEGARA Galaxy Discs Evolution Survey. The initial goal
of MEGADES is to provide a detailed study of the inner regions of nearby disc
galaxies, both in terms of their spectrophotometric and chemical evolution, and
their dynamical characterisation, by disentangling the contribution of in-situ
and ex-situ processes to the history of star formation and effective chemical
enrichment of these regions. In addition, the dynamical analysis of these inner
regions naturally includes the identification and characterization of galactic
winds potentially present in these regions. At a later stage, we will extend
this study further out in galactocentric distance. The first stage of this
project encompasses the analysis of the central regions of a total of 43 nearby
galaxies observed with the MEGARA Integral Field Unit for 114 hours, including
both Guaranteed Time and Open Time observations. In this paper we provide a set
of all the processed data products available to the community and early results
from the analysis of these data regarding stellar continuum, ionized and
neutral gas features.Comment: Accepted for publication in Astronomy & Astrophysic
Updated Iberian archeomagnetic catalogue: new full vector paleosecular variation curve for the last three millennia
In this work, we present 16 directional and 27 intensity high‐quality values from Iberia. Moreover, we have updated the Iberian archeomagnetic catalogue published more than 10 years ago with a considerable increase in the database. This has led to a notable improvement of both temporal and spatial data distribution. A full vector paleosecular variation curve from 1000 BC to 1900 AD has been developed using high‐quality data within a radius of 900 km from Madrid. A hierarchical bootstrap method has been followed for the computation of the curves. The most remarkable feature of the new curves is a notable intensity maximum of about 80 μT around 600 BC, which has not been previously reported for the Iberian Peninsula. We have also analyzed the evolution of the paleofield in Europe for the last three thousand years and conclude that the high maximum intensity values observed around 600 BC in the Iberian Peninsula could respond to the same feature as the Levantine Iron Age Anomaly, after travelling westward through Europe
MEGARA-GTC stellar spectral library: I
MEGARA (Multi Espectrografo en GTC de Alta Resolucion para Astronomia) is an optical (3650-9750 Å), fibre-fed, medium-high spectral resolution (R = 6000, 12 000 and 20 000) instrument for the Gran Telescopio CANARIAS (GTC) 10.4-m telescope, commissioned in the summer of 2017, and currently in operation. The scientific exploitation of MEGARA requires a stellar spectra library to interpret galaxy data and to estimate the contribution of the stellar populations. In this paper, we introduce the MEGARA-GTC spectral library, detailing the rationale behind the building of this catalogue. We present the spectra of 97 stars (21 individual stars and 56 members of the globular cluster M15, which are both subsamples taken during the commissioning runs, and 20 stars from our ongoing GTC Open-Time programme). The spectra have R = 20 000 in the HR-R and HR-I set-ups, centred at 6563 and 8633 Å, respectively. We describe the procedures to reduce and analyse the data. Then, we determine the best-fitting theoretical models to each spectrum through a χ^(2) minimization technique, to derive the stellar physical parameters, and we discuss the results. We have also measured some absorption lines and indices. Finally, we introduce our project to complete the library and the data base in order to make the spectra available to the community
She\u27s So Bubbly
We introduce the Automatic Learning for the Rapid Classification of Events (ALeRCE) broker, an astronomical alert broker designed to provide a rapid and self-consistent classification of large etendue telescope alert streams, such as that provided by the Zwicky Transient Facility (ZTF) and, in the future, the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). ALeRCE is a Chilean-led broker run by an interdisciplinary team of astronomers and engineers working to become intermediaries between survey and follow-up facilities. ALeRCE uses a pipeline that includes the real-time ingestion, aggregation, cross-matching, machine-learning (ML) classification, and visualization of the ZTF alert stream. We use two classifiers: a stamp-based classifier, designed for rapid classification, and a light curve–based classifier, which uses the multiband flux evolution to achieve a more refined classification. We describe in detail our pipeline, data products, tools, and services, which are made public for the community (see https://alerce.science). Since we began operating our real-time ML classification of the ZTF alert stream in early 2019, we have grown a large community of active users around the globe. We describe our results to date, including the real-time processing of 1.5 × 10⁸ alerts, the stamp classification of 3.4 × 10⁷ objects, the light-curve classification of 1.1 × 10⁶ objects, the report of 6162 supernova candidates, and different experiments using LSST-like alert streams. Finally, we discuss the challenges ahead in going from a single stream of alerts such as ZTF to a multistream ecosystem dominated by LSST
The nature of the Cygnus extreme B supergiant 2MASS J20395358+4222505
2MASS J20395358+4222505 is an obscured early B supergiant near the massive OB star association Cygnus OB2. Despite its bright infrared magnitude (Ks = 5.82) it has remained largely ignored because of its dim optical magnitude (B = 16.63, V = 13.68). In a previous paper, we classified it as a highly reddened, potentially extremely luminous, early B-type supergiant. We obtained its spectrum in the U, B and R spectral bands during commissioning observations with the instrument MEGARA at the Gran Telescopio CANARIAS. It displays a particularly strong Hα emission for its spectral type, B1 Ia. The star seems to be in an intermediate phase between supergiant and hypergiant, a group that it will probably join in the near (astronomical) future. We observe a radial velocity difference between individual observations and determine the stellar parameters, obtaining Teff = 24 000 K and log gc = 2.88 ± 0.15. The rotational velocity found is large for a B supergiant, v sin i = 110 ± 25 kms−1. The abundance pattern is consistent with solar, with a mild C underabundance (based on a single line). Assuming that J20395358+4222505 is at the distance of Cyg OB2, we derive the radius from infrared photometry, finding R = 41.2 ± 4.0 R⊙, log(L/L⊙) = 5.71 ± 0.04 and a spectroscopic mass of 46.5 ± 15.0 M⊙. The clumped mass-loss rate (clumping factor 10) is very high for the spectral type, M˙ = 2.4 × 10−6 M⊙ a−1. The high rotational velocity and mass-loss rate place the star at the hot side of the bi-stability jump. Together with the nearly solar CNO abundance pattern, they may also point to evolution in a binary system, J20395358+4222505 being the initial secondary.SS-D and AH acknowledge support from the Spanish Government Ministerio de Ciencia e Innovación through grants PGC-2018-091 3741-B-C22 and CEX2019-000920-S and from the Canarian Agency for Research, Innovation and Information Society (ACIISI), of the Canary Islands Government, and the European Regional Development Fund (ERDF), under grant with reference ProID2020010016. MG and FN acknowledge financial support through Spanish grant PID2019-105552RB-C41 (MINECO/MCIU/AEI/FEDER) and from the Spanish State Research Agency (AEI) through the Unidad de Excelencia ‘María de Maeztu’-Centro de Astrobiología (CSIC-INTA) project No. MDM-2017-0737. SRB acknowledges support by the Spanish Government under grants AYA2015-68012-C2-2-P and PGC2018-093741-B-C21/C22 (MICIU/AEI/FEDER, UE). SRA acknowledges funding support from the FONDECYT Iniciación project 11171025 and the FONDECYT Regular project 1201490. JIP acknowledges finantial support from projects Estallidos6 AYA2016-79724-C4 (Spanish Ministerio de Economia y Competitividad), Estallidos7 PID2019-107408GB-C44 (Spanish Ministerio de Ciencia e Innovacion), grant P18-FR-2664 (Junta de Andalucía), and grant SEV-2017-0709 ‘Centro de Excelencia Severo Ochoa Program’ (Spanish Science Ministry). AGP, SP, AG-M, JG and NC acknowledge support from the Spanish MCI through project RTI2018-096188-B-I00
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