5,164 research outputs found
Alimentació, model estètic femenà i mitjans de comunicació entre els adolescents
La preocupació pel cos i l'estètica i els mals hà bits en l'alimentació comporten trastorns en la conducta alimentà ria cada cop més freqüents i persistensts en nens i adolescents. Investigadors de la UAB han dissenyat un original programa de prevenció de trastorns alimentaris a les escoles que combina una acció directa sobre els hà bits alimentaris dels adolescents -corregint falses creences sobre nutrició i alimentació, proporcionant coneixements sobre una alimentació equilibrada i promovent l'anà lisi participatiu dels menús- amb una alfabetització medià tica que els permeti generar una anà lisi crÃtica del model estètic imperant i dels anuncis publicitaris. El programa ha demostrat ser eficaç en prevenir tant l'aparició d'actituds alterades cap al menjar com en reduir la influència dels ideals estètics corporals en una mostra mixta d'adolescents escolaritzats.La preocupación por el cuerpo y la estética y los malos hábitos en la alimentación conllevan trastornos en la conducta alimentaria cada vez más frecuentes y persistentes en niños y adolescentes. Investigadores de la UAB han diseñado un original programa de prevención de trastornos alimentarios en las escuelas que combina una acción directa sobre los hábitos alimentarios de los adolescentes -corrigiendo falsas creencias sobre nutrición y alimentación, proporcionando conocimientos sobre una alimentación equilibrada y promoviendo el análisis participativo de los menús- con una alfabetización mediática que les permita generar un análisis crÃtico del modelo estético imperante y los anuncios publicitarios. El programa ha demostrado ser eficaz en prevenir tanto la aparición de actitudes alteradas hacia la comida como en reducir la influencia de los ideales estéticos corporales en una muestra mixta de adolescentes escolarizados
Thiol precursors in Catarratto Bianco Comune and Grillo grapes and effect of clarification conditions on the release of varietal thiols in wine
Background and aims: Varietal thiols characterize the typical aroma of several white wines, as Sauvignon blanc. Their presence was suggested in two Sicilian grape cultivars, Catarratto Bianco Comune (CBC) and Grillo, thought it was not analytically proved to date.
Methods and Results: Varietal thiol precursors and free varietal thiols were assessed in CBC and Grillo grapes, musts and wines by UPLC/high resolution mass spectrometry (HRMS). The isobaric compounds S-3-(hexanal)-glutathione (GSH-3MHAl) and S-3-(4-mercapto-4-methylpentan-2-one)-glutathione (GSH-4MMP) were discriminated by comparing their accurate masses and HR-MS/MS spectra with those of their synthetic standards. GSH-3MHAl, S-3-(hexan-1-ol)-glutathione (GSH-3MH) and S-3-(hexan-1-ol)-cysteine occurred in grape, must and wine, while GSH-4MMP and its hydrolysed forms did not. Their amounts decreased during the industrial winemaking processes, mostly following the grape pressing. We compared clarification conditions exposing must to either air or CO2 in terms of thiol precursors\u2019 and free thiols\u2019 content in wine. However, negligible differences were observed. Concentrations of free thiols in the range 400\u20131100 ng/L were found in the wines and they were not affected to the two clarification conditions adopted.
Conclusion: The isobaric GSH-3MHAl and GSH-4MMP were clearly distinguished for the first time by UPLC-HRMS through their retention times and MS spectra. The varietal thiols were firstly revealed CBC and Grillo wines. The air-free and air- exposed clarification poorly affected the levels of varietal thiols.
Significance of the study: This research highlights the major impact of the varietal thiols (mainly 3\u2013mercapto-hexan-1-ol and its acetate form) on the sensory properties of CBC and Grillo wines
Evidence for tidal interaction and merger as the origin of galaxy morphology evolution in compact groups
We present the results of a morphological study based on NIR images of 25
galaxies, with different levels of nuclear activity, in 8 Compact Groups of
Galaxies (CGs). We perform independently two different analysis: a isophotal
study and a study of morphological asymmetries. The results yielded by the two
analysis are highly consistent. For the first time, it is possible to show that
deviations from pure ellipses are produced by inhomogeneous stellar mass
distributions related to galaxy interactions and mergers. We find evidence of
mass asymmetries in 74% of the galaxies in our sample. In 59% of these cases,
the asymmetries come in pairs, and are consistent with tidal effects produced
by the proximity of companion galaxies. The symmetric galaxies are generally
small in size or mass, inactive, and have an early-type morphology. In 20% of
the galaxies we find evidence for cannibalism. In 36% of the early-type
galaxies the color gradient is positive (blue nucleus) or flat. Summing up
these results, as much as 52% of the galaxies in our sample could show evidence
of an on going or past mergers. Our observations suggest that galaxies in CGs
merge more frequently under ``dry'' conditions. The high frequency of
interacting and merging galaxies observed in our study is consistent with the
bias of our sample towards CGs of type B, which represents the most active
phase in the evolution of the groups. In these groups we also find a strong
correlation between asymmetries and nuclear activity in early-type galaxies.
This correlation allows us to identify tidal interactions and mergers as the
cause of galaxy morphology transformation in CGs.[abridge]Comment: 64 pages, 35 figures. Accepted for publication in Ap
The SDSS-UKIDSS Fundamental Plane of Early-type Galaxies
We derive the Fundamental Plane (FP) relation for a sample of 1430 early-type
galaxies in the optical (r band) and the near-infrared (K band), by combining
SDSS and UKIDSS data. With such a large, homogeneous dataset, we are able to
assess the dependence of the FP on the waveband. Our analysis indicates that
the FP of luminous early-type galaxies is essentially waveband independent,
with its coefficients increasing at most by 8% from the optical to the NIR.
This finding fits well into a consistent picture where the tilt of the FP is
not driven by stellar populations, but results from other effects, such as
non-homology. In this framework, the optical and NIR FPs require more massive
galaxies to be slightly more metal rich than less massive ones, and to have
highly synchronized ages, with an age variation per decade in mass smaller than
a few percent.Comment: 7 pages, 2 figures, accepted for publication on Ap
Comparative assessment of satellite- and drone-based vegetation indices to predict arthropod biomass in shrub-steppes
Arthropod biomass is a key element in ecosystem functionality and a basic
food item for many species. It must be estimated through traditional costly
field sampling, normally at just a few sampling points. Arthropod biomass and
plant productivity should be narrowly related because a large majority of
arthropods are herbivorous, and others depend on these. Quantifying plant
productivity with satellite or aerial vehicle imagery is an easy and fast procedure already tested and implemented in agriculture and field ecology.
However, the capability of satellite or aerial vehicle imagery for quantifying
arthropod biomass and its relationship with plant productivity has been
scarcely addressed. Here, we used unmanned aerial vehicle (UAV) and satellite Sentinel-2 (S2) imagery to establish a relationship between plant productivity and arthropod biomass estimated through ground-truth field sampling in
shrub steppes. We UAV-sampled seven plots of 47.6–72.3 ha at a 4-cm pixel
resolution, subsequently downscaling spatial resolution to 50 cm resolution.
In parallel, we used S2 imagery from the same and other dates and locations at
10-m spatial resolution. We related several vegetation indices (VIs) with
arthropod biomass (epigeous, coprophagous, and four functional consumer
groups: predatory, detritivore, phytophagous, and diverse) estimated at 41–48
sampling stations for UAV flying plots and in 67–79 sampling stations for S2.
VIs derived from UAV were consistently and positively related to all arthropod
biomass groups. Three out of seven and six out of seven S2-derived VIs were
positively related to epigeous and coprophagous arthropod biomass, respectively. The blue normalized difference VI (BNDVI) and enhanced normalized
difference VI (ENDVI) showed consistent and positive relationships with
arthropod biomass, regardless of the arthropod group or spatial resolution. Our results showed that UAV and S2-VI imagery data may be viable and
cost-efficient alternatives for quantifying arthropod biomass at large scales
in shrub steppes. The relationship between VI and arthropod biomass is
probably habitat-dependent, so future research should address this relationship and include several habitats to validate VIs as proxies of arthropod
biomassBBVA Foundation, BBVA Dron Ricoti
project; European Commission, Grant/
Award Number: LIFE15-NAT-ES-000802;
REMEDINAL-3 from CAM; European
Comission, Grant/Award Number:
LIFE20-NAT-ES-00013
MAP entropy estimation: applications in robust image filtering
We introduce a new approach for image filtering in a Bayesian framework. In this case the probability density function (pdf) of thelikelihood function is approximated using the concept of non-parametric or kernel estimation. The method is based on the generalizedGaussian Markov random fields (GGMRF), a class of Markov random fields which are used as prior information into the Bayesian rule, whichprincipal objective is to eliminate those effects caused by the excessive smoothness on the reconstruction process of images which arerich in contours or edges. Accordingly to the hypothesis made for the present work, it is assumed a limited knowledge of the noise pdf,so the idea is to use a non-parametric estimator to estimate such a pdf and then apply the entropy to construct the cost function for thelikelihood term. The previous idea leads to the construction of Maximum a posteriori (MAP) robust estimators, since the real systems arealways exposed to continuous perturbations of unknown nature. Some promising results of three new MAP entropy estimators (MAPEE) forimage filtering are presented, together with some concluding remarks
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