500 research outputs found
Processing of Threat-related Information Outside the Focus of Visual Attention
En el presente estudio se investiga si las palabras relativas a peligros se perciben fuera del campo de atención visual. En una tarea de decisión léxica se presentaron como estímulos de prueba palabras representativas de peligro, otras de contenido emocional positivo, y otras neutras. La palabra de prueba iba precedida por 2 palabras-contexto simultáneas (1 en posición foveal, en el centro del campo visual; 1 parafoveal, desplazada 2.2 grados a izquierda o derecha) durante 150 ms. Una de las palabras-contexto era idéntica a la de prueba o bien no estaba relacionada ésta. Los resultados mostraron facilitación en la tarea de decisión léxica para las palabras de peligro cuando estaban precedidas por una palabra idéntica en el campo parafoveal derecho. Se concluye que las palabras de peligro tienen un acceso privilegiado (en comparación con las neutras y con las positivas) para ser analizadas fuera del foco de atención. Esto revela un sesgo cognitivo en el procesamiento preferente y en paralelo de la información con importancia adaptativa.This study investigates whether threat-related words are especially likely to be perceived in unattended locations of the visual field. Threat-related, positive, and neutral words were presented at fixation as probes in a lexical decision task. The probe word was preceded by 2 simultaneous prime words (1 foveal, i.e., at fixation; 1 parafoveal, i.e., 2.2 deg. of visual angle from fixation), which were presented for 150 ms, one of which was either identical or unrelated to the probe. Results showed significant facilitation in lexical response times only for the probe threat words when primed parafoveally by an identical word presented in the right visual field. We conclude that threat-related words have privileged access to processing outside the focus of attention. This reveals a cognitive bias in the preferential, parallel processing of information that is important for adaptation
Structure and antigenicity changes in 7S soyabean allergen by enzymic deglycosylation
peer-reviewedno abstract availablePUBLISHEDpeer-reviewe
Advanced analysis of carbohydrates in foods
In this chapter, modern analytical procedures used to study carbohydrates in foods and
beverages are discussed. The main advanced analytical methodologies applied to determine
the different carbohydrate families (monosaccharides, oligosaccharides, polysaccharides and
macromolecules including different glycosilated compounds) are reviewed considering the
sample preparation required and the type of technique (separation or spectroscopic) used,
including their different couplings, multidimensional- approaches, modern glycomics
strategies, etc. The goal of this contribution is, therefore, to provide the reader with a broad
and critical view on the different analytical methods nowadays employed to analyze
carbohydrates in foods and their foreseeable trends.Peer Reviewe
Memoria operativa y procesos de integración en la comprensión de textos
The aim was to examine the influence of working memory capacity on the integration of information across sentences during reading. Subjects high or low in reading span read texts under three conditions: (a) reading regressions and self-paced reading allowed, (b) self-paced reading (no regressions), and (e) fixed-pace reading (no regressions or selfpaced reading). Two kinds of regressive fixations - between- and withinsentence- were measured; and two types of comprehension questions - detail and integration - were used. The results indicated that (a) highspan subjects made more regressive movements, especially between-sentence regressions, than low-anxiety subjects; but (b) comprehension performance and efficiency were lower for low-span than for high-span readers, with both integration and detail questions, under all three reading conditions. The findings on regressive movements are consistent with the idea that subjects low in working memory capacity resort to reading regressions as un auxiliary strategy to carry out integration processes, in order to compensate for their capacity lirnitations. In contrast, the data concerning comprehension suggest that the frequent use of regressive fixations and reading time by readers low in working memory capacity is not a real compensatory mechanism for comprehension, but has a metacognitive function which provides reassurance. Defcits in working memory capacity constrain reading comprehension in general, but not specifically integration processes.Se examina el efecto de la capacidad de la memoria operativa sobre los procesos de integración de información en la lectura de textos. Sujetos con diferente capacidad de memoria operativa leyeron textos bajo tres condiciones: (a) retrocesos posibles y tiempo libre de lectura, (b) tiempo libre (pero no retrocesos), y (e) presentación prejijada (tiempo fijo y no retrocesos). Se midieron dos tipos de retrocesos durante la lectura: intra-frase e inter-frases; y se presentaron dos tipos de preguntas de comprensión: detalle e integración. Los resultados indicaron que: (a) los lectorescon menor capacidad hicieron mas retrocesos que los de mayor capacidad, especialmente inter-frases; pero (b) los primeros tuvieron peor comprensión y eficiencia que los segundos en todas las condiciones de lectura y en ambos tipos de preguntas. El dato relativo a los retrocesos hace suponer que los lectores con menor capacidad recurren a los retrocesos como una estrategia auxiliar para llevar a cabo los procesos de integración, a fin de compensar sus propias deficiencias en capacidad. En contraste, los datos relativos a la comprensión sugieren que el uso extraordinario de retrocesos y el tiempo de lectura adicional en las personas con menor capacidad cumplen una función metacognitiva más que cognitiva, ya que no son eficaces para compensar esas deficiencias. Además, las limitaciones en capacidad de la memoria operativa afectan negativamente a la comprensión lectora de modo general, no específicamente a los procesos de integración
Insights on the health benefits of the bioactive compounds of coffee silverskin extract
The bioaccessibility of chlorogenic acid (CGA) and caffeine in coffee silverskin extracts (CSE) and the contribution of these substances to the prophylactic effect of CSE on the pathogenesis of diabetes have not been reported. This study aimed to evaluate the bioaccessibility, bioavailability and bioactivity of CGA and caffeine alone and in CSE in the pancreas of rats treated with streptozotocin-nicotinamide (type 2 diabetes model). Metabolism of CGA and caffeine started in the gastrointestinal tract due to changes of pH taking place during digestion. Their metabolites protected pancreatic cells against the risk of diabetes. This is the first in vivo study to demonstrate a specific chemo-protective effect of CSE in pancreatic tissue, and this effect may be associated with its antioxidant capacity. Daily administration of CSE, CGA or caffeine 35 d previous to the induction of diabetes significantly reduced (p < 0.05) pancreatic oxidative stress and protein damage.This work was supported by grants from SUSCOFFEE (AGL2014-57239-R) and SAMID (RD12/0026). B. Fernandez-Gomez thanks the PhD program of MINECO for supporting her research career (BES-2011-046827). SAMID RETICS is funded by the PN I+D+I 2012-2016 (Spain), ISCIII- Sub-Directorate General for Research Assessment and Promotion and the European Regional Development Fund (ERDF), ref. RD12/0026.Peer Reviewe
Facts about the formation of newantioxidants in natural samples after subcritical water extraction
8 páginas, 3 figuras, 3 tablas.-- El pdf del artículo es la versión pre-print.Subcritical water extraction (SWE) is a very promising technique for obtaining bioactives (mainly
antioxidants) from natural sources; even if sometimes the high operation temperatures have been
suggested as responsible for thermal degradation of bioactives, the fact is that this type of extraction
processes may generate new bioactive (antioxidant) compounds. The present study involved the analysis of
antioxidants either naturally found in raw samples and/or those formed during extraction via Maillard
reaction and other chemical events. Samples of different nature like microalgae (Chlorella vulgaris), algae
(Sargassum vulgare, Porphyra spp., Cystoseira abies-marina, Sargassum muticum, Undaria pinnatifida, and
Halopitys incurvus) and plants (rosemary, thyme and verbena) were studied. Amino acid availability, sugar
content, fluorescence and absorbance at different wavelengths were determined to follow chemical changes
due to reactions such as Maillard, caramelization and thermoxidation. Folin reaction also provided
information related to total phenol content of the samples. ABTS•+, peroxyl as well as superoxide radical
scavenging assays were used to measure the antioxidant capacity of the extracts. Results obtained from this
study suggest that neoformed compounds derived from Maillard, caramelization and thermoxidation
reactions affect the overall antioxidant capacity of water subcritical extracts depending on the nature of the
sample. The brown algae U. pinnatifida was the sample in which these chemical events contributed to a
higher extent to improve the antioxidant capacity (from 0.047 to 1.512 mmol/g and from 45.356 to
1522.692 μmol/g for the TEAC and ORACFL methods, respectively) when the extraction temperature was
raised from 100 to 200 °C. To the best of our knowledge, this is the first work supporting the formation of
neoantioxidants in natural complex matrices during subcritical water extraction.This work has been financed by AGL2008-05108-C03-01 (Ministerio
de Educacion y Ciencia), CSD2007-00063 FUN-CFOOD (Programa
CONSOLIDER-INGENIO 2010) and by ALIBIRD, S2009/AGR-
1469 (Comunidad de Madrid) projects. M.H. would like to thank the
Spanish Science and Innovation Ministry (MICINN) for a post-doc
contract (“Juan de la Cierva” programme). M.P. thanks CSIC for her I3P
fellowship. M.A.B. thanks for a Danone Institute fellowship.Peer reviewe
Exposure of Trypanosoma brucei to an N-acetylglucosamine-binding lectin induces VSG switching and glycosylation defects resulting in reduced infectivity
Trypanosoma brucei variant surface glycoproteins (VSG) are glycosylated by both paucimannose and oligomannose structures which are involved in the formation of a protective barrier against the immune system. Here, we report that the stinging nettle lectin (UDA), with predominant N-acetylglucosamine-binding specificity, interacts with glycosylated VSGs and kills parasites by provoking defects in endocytosis together with impaired cytokinesis. Prolonged exposure to UDA induced parasite resistance based on a diminished capacity to bind the lectin due to an enrichment of biantennary paucimannose and a reduction of triantennary oligomannose structures. Two molecular mechanisms involved in resistance were identified: VSG switching and modifications in N-glycan composition. Glycosylation defects were correlated with the down-regulation of the TbSTT3A and/or TbSTT3B genes (coding for oligosaccharyltransferases A and B, respectively) responsible for glycan specificity. Furthermore, UDA-resistant trypanosomes exhibited severely impaired infectivity indicating that the resistant phenotype entails a substantial fitness cost. The results obtained further support the modification of surface glycan composition resulting from down-regulation of the genes coding for oligosaccharyltransferases as a general resistance mechanism in response to prolonged exposure to carbohydrate-binding agents
Immunochemical and mass spectrometric analysis of N<sup>ε</sup>-(carboxymethyl)lysine content of AGE-BSA systems prepared with and without selected antiglycation agents
Coffee silverskin extract protects against accelerated aging caused by oxidative agents
Nowadays, coffee beans are almost exclusively used for the preparation of the beverage. The sustainability of coffee production can be achieved introducing new applications for the valorization of coffee by-products. Coffee silverskin is the by-product generated during roasting, and because of its powerful antioxidant capacity, coffee silverskin aqueous extract (CSE) may be used for other applications, such as antiaging cosmetics and dermaceutics. This study aims to contribute to the coffee sector’s sustainability through the application of CSE to preserve skin health. Preclinical data regarding the antiaging properties of CSE employing human keratinocytes and Caenorhabditis elegans are collected during the present study. Accelerated aging was induced by tert-butyl hydroperoxide (t-BOOH) in HaCaT cells and by ultraviolet radiation C (UVC) in C. elegans. Results suggest that the tested concentrations of coffee extracts were not cytotoxic, and CSE 1 mg/mL gave resistance to skin cells when oxidative damage was induced by t-BOOH. On the other hand, nematodes treated with CSE (1 mg/mL) showed a significant increased longevity compared to those cultured on a standard diet. In conclusion, our results support the antiaging properties of the CSE and its great potential for improving skin health due to its antioxidant character associated with phenols among other bioactive compounds present in the botanical materialThe authors are grateful for the financial support from the SUSCOFFEE Project
(AGL2014-57239-R) and the NATURAGE Project (AGL2010-17779). This work was partially funded by a Santander
Small and Medium Enterprises Work Placement Grant in Beacon Biomedicine. Amaia Iriondo is a fellow of the FPI predoctoral program of the Ministry of Economy and Competitiveness (BES-2015-072191). Konstantinos Stamatakis is a recipient of an Asociación Española Contra el Cancer fellowship.We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)
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