2,497 research outputs found
La comunicación en las sedes webs de las universidades a distancia españolas
Esta investigaciĂłn analiza la comunicaciĂłn de las universidades españolas a distancia en sus sedes webs. En los Ășltimos años este tipo de universidades se han multiplicado por cuatro.
Hoy en dĂa, las sedes webs de las universidades españolas online se ha convertido en una herramienta primordial para comunicar y atraer a pĂșblicos potenciales. Es mĂĄs, en este tipo de universidades la sede web es el medio por el que los alumnos conocen y establecen una relaciĂłn con la universidad.
El fin de este estudio es profundizar en la forma en que las universidades a distancia se comunican a travĂ©s de sus sedes webs. Para ello, este trabajo ha utilizado el anĂĄlisis de contenidos con el fin de estudiar las sedes webs de las universidades españolas a distancia.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech
A Multi-Omics Analysis Pipeline for the Metabolic Pathway Reconstruction in the Orphan Species Quercus ilex
Holm oak (Quercus ilex) is the most important and representative species of the Mediterranean forest and of the Spanish agrosilvo-pastoral âdehesaâ ecosystem. Despite its environmental and economic interest, Holm oak is an orphan species whose biology is very little known, especially at the molecular level. In order to increase the knowledge on the chemical composition and metabolism of this tree species, the employment of a holistic and multi-omics approach, in the Systems Biology direction would be necessary. However, for orphan and recalcitrant plant species, specific analytical and bioinformatics tools have to be developed in order to obtain adequate quality and data-density before to coping with the study of its biology. By using a plant sample consisting of a pool generated by mixing equal amounts of homogenized tissue from acorn embryo, leaves, and roots, protocols for transcriptome (NGS-Illumina), proteome (shotgun LC-MS/MS), and metabolome (GC-MS) studies have been optimized. These analyses resulted in the identification of around 62629 transcripts, 2380 protein species, and 62 metabolites. Data are compared with those reported for model plant species, whose genome has been sequenced and is well annotated, including Arabidopsis, japonica rice, poplar, and eucalyptus. RNA and protein sequencing favored each other, increasing the number and confidence of the proteins identified and correcting erroneous RNA sequences. The integration of the large amount of data reported using bioinformatics tools allows the Holm oak metabolic network to be partially reconstructed: from the 127 metabolic pathways reported in KEGG pathway database, 123 metabolic pathways can be visualized when using the described methodology. They included: carbohydrate and energy metabolism, amino acid metabolism, lipid metabolism, nucleotide metabolism, and biosynthesis of secondary metabolites. The TCA cycle was the pathway most represented with 5 out of 10 metabolites, 6 out of 8 protein enzymes, and 8 out of 8 enzyme transcripts. On the other hand, gaps, missed pathways, included metabolism of terpenoids and polyketides and lipid metabolism. The multi-omics resource generated in this work will set the basis for ongoing and future studies, bringing the Holm oak closer to model species, to obtain a better understanding of the molecular mechanisms underlying phenotypes of interest (productive, tolerant to environmental cues, nutraceutical value) and to select elite genotypes to be used in restoration and reforestation programs, especially in a future climate change scenario
Responses and Differences in Tolerance to Water Shortage under Climatic Dryness Conditions in Seedlings from Quercus spp. and Andalusian Q. ilex Populations
Analyzing differences in tolerance to drought in Quercus spp., and the characterization of these responses at the species and individual population level, are imperative for the selection of resilient elite genotypes in reforestation programs. The main objective of this work was to evaluate differences in the response and tolerance to water shortage under in five Quercus spp. and five Andalusian Q. ilex populations at the inter- and intraspecies level. Six-month-old seedlings grown in perlite were subjected to drought treatments by withholding water for 28 days under mean 37 °C temperature, 28 W m-2 solar irradiance, and 41% humidity. The use of perlite as the substrate enabled the establishment of severe drought stress with reduction in water availability from 73% (field capacity) to 28% (dryness), corresponding to matric potentials of 0 and â30 kPa. Damage symptoms, mortality rate, leaf water content, photosynthetic, and biochemical parameters (amino acids, sugars, phenolics, and pigments) were determined. At the phenotypic level, based on damage symptoms and mortality, Q. ilex behaved as the most drought tolerant species. Drought caused a significant decrease in leaf fluorescence, photosynthesis rate, and stomatal conductance in all Quercus spp. analyzed, being less pronounced in Q. ilex. There were not differences between irrigated and non-irrigated Q. ilex seedlings in the content of sugar and photosynthetic pigments, while the total amino acid and phenolic content significantly increased under drought conditions. As a response to drought, living Q. ilex seedlings adjust stomata opening and gas exchange, and keep hydrated, photosynthetically active, and metabolically competent. At the population level, based on damage symptoms, mortality, and physiological parameters, the eastern Andalusian populations were more tolerant than the western ones. These observations inform the basis for the selection of resilient genotypes to be used in breeding and reforestation programs
NADPH-thioredoxin reductase c mediates the response to oxidative stress and thermotolerance in the cyanobacterium anabaena sp. pcc7120
NADPH-thioredoxin reductase C (NTRC) is a bimodular enzyme composed of an NADPH-thioredoxin reductase and a thiioredoxin domain extension in the same protein. In plants, NTRC has been described to be involved in the protection of the chloroplast against oxidative stress damage through reduction of the 2-Cys peroxiredoxin (2- Cys Prx) as well as through other functions related to redox enzyme regulation. In cyanobacteria, the Anabaena NTRC has been characterized in vitro, however, nothing was known about its in vivo function. In order to study that, we have generated the first knockout mutant strain (LintrC), apart from the previously described in Arabidopsis. Detailed characterization of this strain reveals a differential sensitivity to oxidative stress treatments with respect to the wild-type Anabaena strain, including a higher level of ROS (reactive oxygen species) in normal growth conditions. In the mutant strain, different oxidative stress treatments such as hydrogen peroxide, methyl-viologen or high light irradiance provoke an increase in the expression of genes related to ROS detoxification, including AnNTRC and peroxiredoxin genes, with a concomitant increase in the amount of AnNTRC and 2-Cys Prx. Moreover, the role of AnNTRC in the antioxidant response is confirmed by the observation of a pronounced overoxidation of the 2-Cys Prx and a time-delay recovery of the reduced form of this protein upon oxidative stress treatments. Our results suggest the participation of this enzyme in the peroxide detoxification in Anabaena. In addition, we describe the role of Anabaena NTRC in thermotolerance, by the appearance of high molecular mass AnNTRC complexes, showing that the mutant strain is more sensitive to high temperature treatment
Combining data from primary and ancillary surveys to assess the association between neighborhood-level characteristics and health outcomes: the Multi-Ethnic Study of Artherosclerosis
There is increasing interest in understanding the role of neighborhood-level factors on the health of individuals. Many large-scale epidemiological studies that accurately measure health status of individuals and individual risk factors exist. Sometimes these studies are linked to area-level databases (e.g. census) to assess the association between crude area-level characteristics and health. However, information from such databases may not measure the neighborhood-level constructs of interest. More recently, large-scale epidemiological studies have begun collecting data to measure specific features of neighborhoods using ancillary surveys. The ancillary surveys are composed of a separate, typically larger, set of individuals. The challenge is then to combine information from these two surveys to assess the role of neighborhood-level factors. We propose a method for combining information from the two data sources using a likelihood-based framework. We compare it with currently used ad hoc approaches via a simulation study. The simulation study shows that the proposed approach yields estimates with better sampling properties (less bias and better coverage probabilities) compared with the other approaches. However, there are cases where some ad hoc approaches may provide adequate estimates. We also compare the methods by applying them to the Multi-Ethnic Study of Atherosclerosis and its Neighborhood Ancillary Survey. Copyright © 2008 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/61232/1/3384_ftp.pd
Parkinsonâs disease and autophagy
It is generally accepted that a correlation between neurodegenerative disease and protein aggregation in the brain exists; however, a
causal relationship has not been elucidated. In neurons, failure of autophagy may result in the accumulation of aggregate-prone
proteins and subsequent neurodegeneration. Thus, pharmacological induction of autophagy to enhance the clearance of intracytoplasmic
aggregate-prone proteins has been considered as a therapeutic strategy to ameliorate pathology in cell and animal
models of neurodegenerative disorders. However, autophagy has also been found to be a factor in the onset of these diseases, which
raises the question of whether autophagy induction is an effective therapeutic strategy, or, on the contrary, can result in cell death.
In this paper, we will first describe the autophagic machinery, and we will consider the literature to discuss the neuroprotective
effects of autophagy
A high-fat plus fructose diet produces a vascular prostanoid alterations in the rat
In the rat, a high-fat (HF) plus fructose (F) diet produces cardiovascular and metabolic alterations that resemble human metabolic syndrome. Prostanoids (PR), cyclo-oxygenase-derived arachidonic acid metabolites, have vasoactive properties and mediate inflammation. The aim of this study was to analyse the effect of a HF+F diet on blood pressure (BP), metabolic parameters and mesenteric vascular bed PR production in male Sprague-Dawley rats. Four groups were studied over 9 weeks (n = 6 each): control (C), standard diet (SD) and tap water to drink; F+SD and 10% w/v F solution to drink; HF 50% (w/w) bovine fat added to SD and tap water; and HFF, both treatments. PR were determined by HPLC. Blood pressure was elevated in all experimental groups. Triglyceridaemia, insulinaemia and HOMA-IR were increased in the F and HF groups. HF+F animals showed elevated glycaemia, insulinaemia, HOMA-IR and triglyceridaemia. F decreased the vasodilator prostanoids PGI2 and PGE2 in the mesenteric vascular bed. Body weight was not significantly altered. In HFF, production of PGE2, PGF2alpha and TXB2 was elevated. The increased BP in HF and HFF could be partly attributed to the imbalance in vascular PR production towards vasoconstrictors. On the other hand, this dietary modification could induce inflammation, which would explain the elevation of PGE2. In the F group, hypertension could be related to decreased vasodilator PRs. The simultaneous administration of HF and F in the rat produces deleterious effects greater than observed when treatments are applied separately.Fil: Peredo, Horacio Angel. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Lee, H.. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica; ArgentinaFil: Donoso, Adriana Susana. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica; ArgentinaFil: Andrade, V.. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica; ArgentinaFil: SĂĄnchez Eluchans, N.. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica; ArgentinaFil: PuyĂł, Ana MarĂa. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica; Argentin
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