1,964 research outputs found
Recuperación e identificación de variedades de vid en Aragón
1 copia .pdf del Póster original de los Autores.- 1 Tabl.- 4 Fots. Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)A partir de la década de los setenta diferentes circunstancias provocaron que muchas de las zonas más productivas arrancaran las vides antiguas y apostaran por plantaciones de variedades foráneas o distintas de las tradicionales.
Conscientes de la pérdida de biodiversidad, desde la Unidad de Tecnología Vegetal (Gobierno de Aragón) se viene prospectando en toda la geografía aragonesa y recopilando accesiones de vid, especialmente en viñas antiguas y a punto de desaparecer. El año 1992 se formó el Banco de Germoplasma de Vid de Aragón (Dep. de Agricultura, Ganadería y Medio Ambiente) que conserva más de 700 accesiones (algunas caracterizadas molecularmente, Buhner-Zaharieva et al., 2010) .Este trabajo ha sido financiado por el INIA (RF2012-00027-C05-02) y el Gobierno de Aragón (A44)Peer reviewe
A caricature of a singular curvature flow in the plane
We study a singular parabolic equation of the total variation type in one
dimension. The problem is a simplification of the singular curvature flow. We
show existence and uniqueness of weak solutions. We also prove existence of
weak solutions to the semi-discretization of the problem as well as convergence
of the approximating sequences. The semi-discretization shows that facets must
form. For a class of initial data we are able to study in details the facet
formation and interactions and their asymptotic behavior. We notice that our
qualitative results may be interpreted with the help of a special composition
of multivalued operators
Modelling magnetic flux emergence in the solar convection zone
[Abridged] Bipolar magnetic regions are formed when loops of magnetic flux
emerge at the solar photosphere. Our aim is to investigate the flux emergence
process in a simulation of granular convection. In particular we aim to
determine the circumstances under which magnetic buoyancy enhances the flux
emergence rate (which is otherwise driven solely by the convective upflows). We
use three-dimensional numerical simulations, solving the equations of
compressible magnetohydrodynamics in a horizontally-periodic Cartesian domain.
A horizontal magnetic flux tube is inserted into fully developed hydrodynamic
convection. We systematically vary the initial field strength, the tube
thickness, the initial entropy distribution along the tube axis and the
magnetic Reynolds number. Focusing upon the low magnetic Prandtl number regime
(Pm<1) at moderate magnetic Reynolds number, we find that the flux tube is
always susceptible to convective disruption to some extent. However, stronger
flux tubes tend to maintain their structure more effectively than weaker ones.
Magnetic buoyancy does enhance the flux emergence rates in the strongest
initial field cases, and this enhancement becomes more pronounced when we
increase the width of the flux tube. This is also the case at higher magnetic
Reynolds numbers, although the flux emergence rates are generally lower in
these less dissipative simulations because the convective disruption of the
flux tube is much more effective in these cases. These simulations seem to be
relatively insensitive to the precise choice of initial conditions: for a given
flow, the evolution of the flux tube is determined primarily by the initial
magnetic field distribution and the magnetic Reynolds number.Comment: 12 pages, 15 figures, 2 tables. Accepted for publication in Astronomy
and Astrophysic
Mutant glycyl-tRNA synthetase (Gars) ameliorates SOD1G93A motor neuron degeneration phenotype but has little affect on Loa dynein heavy chain mutant mice
Background:
In humans, mutations in the enzyme glycyl-tRNA synthetase (GARS) cause motor and sensory axon loss in the peripheral nervous system, and clinical phenotypes ranging from Charcot-Marie-Tooth neuropathy to a severe infantile form of spinal muscular atrophy. GARS is ubiquitously expressed and may have functions in addition to its canonical role in protein synthesis through catalyzing the addition of glycine to cognate tRNAs.
Methodology/Principal findings:
We have recently described a new mouse model with a point mutation in the Gars gene resulting in a cysteine to arginine change at residue 201. Heterozygous Gars^{C201R/+} mice have locomotor and sensory deficits. In an investigation of genetic mutations that lead to death of motor and sensory neurons, we have crossed the Gars^{C201R/+} mice to two other mutants: the TgSOD1^{G93A} model of human amyotrophic lateral sclerosis and the Legs at odd angles mouse (Dync1h1^{Loa}) which has a defect in the heavy chain of the dynein complex. We found the Dync1h1^{Loa/+}; Gars^{C201R/+} double heterozygous mice are more impaired than either parent, and this is may be an additive effect of both mutations. Surprisingly, the Gars^{C201R} mutation significantly delayed disease onset in the SOD1^{G93A}; Gars^{C201R/+} double heterozygous mutant mice and increased lifespan by 29% on the genetic background investigated.
Conclusions/Significance:
These findings raise intriguing possibilities for the study of pathogenetic mechanisms in all three mouse mutant strains
Energy solutions to one-dimensional singular parabolic problems with data are viscosity solutions
We study one-dimensional very singular parabolic equations with periodic
boundary conditions and initial data in , which is the energy space. We
show existence of solutions in this energy space and then we prove that they
are viscosity solutions in the sense of Giga-Giga.Comment: 15 page
Validación durante cuatro años de un sistema experto para optimizar el uso de herbicidas en cereales de invierno en condiciones agronómicas españolas
CPOWeeds is a version of Danish Crop Protection online adjusted to conditions in North-eastern Spain. The predicted efficacies and the yield obtained with CPOWeeds were validated in winter cereal field trials from 2010 to 2013. The predictions from CPOWeeds were compared to the actually achieved efficacies in the field trials for the nine weed species at different developmental stages and for 84.2% of the comparisons the obtained efficacies were equal to or higher than predicted. It was concluded that the use of CPOWeeds allowed optimisation of the herbicide application with a very high robustness. The recommendations were satisfactorily for the conditions of the Northeast of Spain and have the potential to decrease the amount of applied herbicides by at least 30%. Therefore, it can be an important tool in Integrated Weed Management.El CPOWeeds es una versión del Crop Protection Online danés puesto a punto para las condiciones del noroeste (NE) de España. Las eficacias predichas por el programa se han validado en ensayos en cereal de invierno desde 2010 a 2013. Las predicciones dadas por el CPOWeeds se han comprobado para nueve especies de malas hierbas en diferentes estadios fenológicos y en el 84,2% de los casos las eficacias han sido iguales o superiores a las predichas. Se concluye que el uso del CPOWeeds permite optimizar la aplicación de herbicidas con una gran robustez. Las recomendaciones son satisfactorias para el NE de España y se puede disminuir la cantidad de herbicidas aplicados hasta en un 30%. Por tanto, se trata de una herramienta muy importante en el Manejo Integrado de Malas Hierbas
The large-scale Quasar-Lyman \alpha\ Forest Cross-Correlation from BOSS
We measure the large-scale cross-correlation of quasars with the Lyman
\alpha\ forest absorption in redshift space, using ~ 60000 quasar spectra from
Data Release 9 (DR9) of the Baryon Oscillation Spectroscopic Survey (BOSS). The
cross-correlation is detected over a wide range of scales, up to comoving
separations r of 80 Mpc/h. For r > 15 Mpc/h, we show that the cross-correlation
is well fitted by the linear theory prediction for the mean overdensity around
a quasar host halo in the standard \Lambda CDM model, with the redshift
distortions indicative of gravitational evolution detected at high confidence.
Using previous determinations of the Lyman \alpha\ forest bias factor obtained
from the Lyman \alpha\ autocorrelation, we infer the quasar bias factor to be
b_q = 3.64^+0.13_-0.15 at a mean redshift z=2.38, in agreement with previous
measurements from the quasar auto-correlation. We also obtain a new estimate of
the Lyman \alpha\ forest redshift distortion factor, \beta_F = 1.1 +/- 0.15,
slightly larger than but consistent with the previous measurement from the
Lyman \alpha\ forest autocorrelation. The simple linear model we use fails at
separations r < 15 Mpc/h, and we show that this may reasonably be due to the
enhanced ionization due to radiation from the quasars. We also provide the
expected correction that the mass overdensity around the quasar implies for
measurements of the ionizing radiation background from the line-of-sight
proximity effect.Comment: 24 pages, 6 figures, published in JCA
Long-Term water stress and drought assessment of Mediterranean oak savanna vegetation using thermal remote sensing
Drought is a devastating natural hazard that is difficult to define, detect and quantify. The increased availability of both meteorological and remotely sensed data provides an opportunity to develop new methods to identify drought conditions and characterize how drought changes over space and time. In this paper, we applied the surface energy balance model, SEBS (Surface Energy Balance System), for the period 2001 2018, to estimate evapotranspiration and other energy fluxes over the dehesa area of the Iberian Peninsula, with a monthly temporal resolution and 0.05° pixel size. A satisfactory agreement was found between the fluxes modeled and the measurements obtained for 3 years by two flux towers located over representative sites (RMSD = 21 W m-2 and R2 = 0.76, on average, for all energy fluxes and both sites). The estimations of the convective fluxes (LE and H) showed higher deviations, with RMSD = 26 W m-2 on average, than Rn and G, with RMSD = 15 W m-2. At both sites, annual evapotranspiration (ET) was very close to total precipitation, with the exception of a few wet years in which intense precipitation events that produced high runoff were observed. The analysis of the anomalies of the ratio of ET to reference ET (ETo) was used as an indicator of agricultural drought on monthly and annual scales. The hydrological years 2004/2005 and 2011/2012 stood out for their negative values. The first one was the most severe of the series, with the highest impact observed on vegetation coverage and grain production. On a monthly scale, this event was also the longest and most intense, with peak negative values in January February and April May 2005, explaining its great impact on cereal production (up to 45 % reduction). During the drier events, the changes in the grasslands and oak trees ground cover allowed for a separate analysis of the strategies adopted by the two strata to cope with water stress. These results indicate that the drought events characterized for the period did not cause any permanent damage to the vegetation of dehesa systems. The approach tested has proven useful for providing insight into the characteristics of drought events over this ecosystem and will be helpful to identify areas of interest for future studies at finer resolutions
Gender recognition from a partial view of the face using local feature vectors
This paper proposes a gender recognition scheme focused on local appearance-based features to describe the top half of the face. Due to the fact that only the top half of the face is used, this is a
feasible approach in those situations where the bottom half is hidden. In the experiments, several face detection methods with different precision levels are used in order to prove the robustness of the scheme with respect to variations in the accuracy level of the face detection proces
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