264 research outputs found
Essential oil composition of leaves of Pistacia lentiscus L. growing wild in Valencia (Spain)
[EN] Pistacia lentiscus L. grows wild in a wide range of habitats in Mediterranean countries. The essential oil (EO) composition of its aerial parts has been extensively studied showing noticeable differences according to plant organ (leaves and twigs or fruits), geographical origin and harvest time. In this study, EO composition of leaves of samples coming from two representative habitats from Valencia (Spain) -siliceous (Segart) and calcicolous (Xeraco) soils-were determined by GC/MS and GC/FID. Hydrocarbon monoterpenes was found the major fraction (57.5 %) in calcicolous soil, whereas hydrocarbon sesquiterpenes was in siliceous soil (39.9 %). Oxygenated monoterpenes reached a significant higher amount in leaves from siliceous location (11.2 %) as against calcicolous one (6.7 %). The rate of oxygenated sesquiterpenes was also higher in siliceous soil (15.2 % in contrast to 1.6 % in calcicolous one. These results lead to consider soil parameters as hypothetical source of EO composition variability being the target for further researches.Llorens Molina, JA.; Vacas González, S.; Sabater Martínez, J. (2015). Essential oil composition of leaves of Pistacia lentiscus L. growing wild in Valencia (Spain). Natural Volatiles and Essential Oils. 2(4):17-26. http://hdl.handle.net/10251/70897S17262
La confianza y la reputación en los sistemas multiagente
Después de una introducción a los conceptos básicos, presentamos brevemente diversos modelos de confianza y reputación que han sido desarrollados por grupos de investigación en el ámbito de los países de habla hispana (en muchos casos en colaboración con grupos de otros países) y que son a su vez referentes a nivel internacional. Aunque lejos de ser exhaustiva, creemos que la selección de modelos ilustra adecuadamente tanto la problemática como las soluciones que se están aplicando actualmente en este campo.Publicad
Intestinal anti-inflammatory effects of artichoke pectin and modified pectin fractions in the dextran sulfate sodium model of mice colitis. Artificial neural network modelling of inflammatory markers
Anti-inflammatory properties of artichoke pectin and modified fractions (arabinose- and galactose-free)
used at two doses (40 and 80 mg kg−1) in mice with colitis induced by dextran sulfate sodium have been
investigated. Expression of pro-inflammatory markers TNF-α and ICAM-I decreased in groups of mice
treated with original and arabinose-free artichoke pectin while IL-1β and IL-6 liberation was reduced only
in mice groups treated with original artichoke pectin. A decrease in iNOS and TLR-4 expression was
observed for most treatments. Intestinal barrier gene expression was also determined. MUC-1 and
Occludin increased in groups treated with original artichoke pectin while MUC-3 expression also
increased in arabinose-free pectin treatment. Galactose elimination led to a loss of pectin bioactivity.
Characteristic expression profiles were established for each treatment through artificial neural networks
showing high accuracy rates (≥90%). These results highlight the potential amelioration of inflammatory
bowel disease on mice model colitis through artichoke pectin administration.This work has been funded by MICINN of Spain, Projects
AGL2014-53445-R and AGL2017-84614-C2-1-R. Carlos Sabater
thanks his FPU Predoc contract from Spanish MECD (FPU14/
03619)
Intestinal anti-inflammatory effects of artichoke pectin and modified pectin fractions in the dextran sulfate sodium model of mice colitis. Artificial neural network modelling of inflammatory markers
Anti-inflammatory properties of artichoke pectin and modified fractions (arabinose- and galactose-free)
used at two doses (40 and 80 mg kg−1) in mice with colitis induced by dextran sulfate sodium have been
investigated. Expression of pro-inflammatory markers TNF-α and ICAM-I decreased in groups of mice
treated with original and arabinose-free artichoke pectin while IL-1β and IL-6 liberation was reduced only
in mice groups treated with original artichoke pectin. A decrease in iNOS and TLR-4 expression was
observed for most treatments. Intestinal barrier gene expression was also determined. MUC-1 and
Occludin increased in groups treated with original artichoke pectin while MUC-3 expression also
increased in arabinose-free pectin treatment. Galactose elimination led to a loss of pectin bioactivity.
Characteristic expression profiles were established for each treatment through artificial neural networks
showing high accuracy rates (≥90%). These results highlight the potential amelioration of inflammatory
bowel disease on mice model colitis through artichoke pectin administration.This work has been funded by MICINN of Spain, Projects
AGL2014-53445-R and AGL2017-84614-C2-1-R. Carlos Sabater
thanks his FPU Predoc contract from Spanish MECD (FPU14/
03619)
Electrocardiographic Screening of Arrhythmogenic Cardiomyopathy in Genotype-Positive and Phenotype-Negative Relatives
Background: Arrhythmogenic cardiomyopathy is a hereditary cause of ventricular arrhythmias and sudden death. Identifying the healthy genetic carriers who will develop the disease remains a challenge. A novel approach to the analysis of the digital electrocardiograms of mutation carriers through signal processing may identify early electrocardiographic abnormalities.
Methods: A retrospective case–control study included a population of healthy genetics carriers and their wild-type relatives. Genotype-positive/phenotype-negative individuals bore mutations associated with the development of arrhythmogenic cardiomyopathy. The relatives included had a non-pathological 12-lead electrocardiogram, echocardiogram, and a cardiac magnetic resonance. Automatic digital electrocardiographic analyses comprised QRS and terminal activation delay duration, the number of QRS fragmentations, ST slope, and T-wave voltage.
Results: Digital 12-lead electrocardiograms from 41 genotype-positive/ phenotype-negative (29 simple carriers and 12 double mutation carriers) and 73 wild-type relatives were analyzed. No differences in the QRS length, the number of QRS fragmentations, and the voltage of the T-wave were observed. After adjusting for potential confounders, double carriers showed an average ST-slope flatter than those of the simple carriers and wild type [5.18° (0.73–8.01), 7.15° (5.14–11.05), and 11.46° (3.94–17.49), respectively, p = 0.005]. There was a significant negative correlation between the ST slope and the age in genotype-positive/phenotype-negative relatives (r = 0.376, p = 0.021) not observed in their wild-type counterparts (r = 0.074, p = 0.570).
Conclusions: A flattened ST segment may be an early sign of electrical remodeling that precedes T-wave inversion in healthy genetic carriers. A thorough analysis of the digital electrocardiographic signal may help identify and measure early electrical abnormalities
Long-term Resilient Labour Strategies to Deal with the Economic Crisis in Europe Using Qualitative Comparative Analysis (QCA)
The crisis has had a negative impact on both European economies and labour markets with different effects among countries, raising the importance of analysing the labour market resilience. This paper seeks to identify which strategies and labour adjustments have led European labour markets to both resilient and non-resilient results by using Qualitative Comparative Analysis (QCA). The findings show two different configurations explaining 57% of the resilient cases and four configurations explaining 74% of the non-resilient cases. The results of this study revealed three important issues. First of all, the same strategy was found to have different results on labour markets. This fact stressed that the context in which different measures are imposed is a decisive factor in their success. Secondly, resilient strategies underlined the importance of “flexibility”, by increasing temporary employment together with other conditions to escape from the crisis. Finally, the non-resilient results stress the importance of the imbalance between the flexicurity dimensions and the effect of the fall in economic activity on not being resilient in the long-term.La crisis ha tenido un impacto en la economía y en los mercados laborales europeos cuyo efecto se ha mostrado diferencial entre países. Este hecho ha aumentado la importancia del estudio de la resiliencia laboral. Este estudio busca identificar qué estrategias han conducido a un resultado resiliente y no resiliente en Europa mediante el uso del Análisis Comparativo Cualitativo (QCA). Los resultados han identificado dos configuraciones, explicando el 57% de los países resilientes y cuatro configuraciones que explican el 74% de los casos no resilientes. En primer lugar, los resultados han mostrado que una misma estrategia puede tener un impacto diferente subrayando la idiosincrasia de cada país como factor decisivo para la resiliencia. En segundo lugar, las estrategias resilientes destacaron la “flexibilidad”, al aumentar el empleo temporal junto con otras condiciones, como factor clave para escapar de la crisis. Finalmente, los resultados no resilientes subrayaron el desequilibrio entre las dimensiones de flexiguridad y el efecto de la caída de la actividad económica como principales causas de un resultado negativo
Fluctuations of conformational mobility of macromolecules around the glass transition
[EN] The heterogeneity of local dynamics in disordered systems is behind some key features of glass transition. In
order to improve our understanding of the molecular dynamics in disordered systems in the vicinity of the glass
transition, different parameters have been proposed to quantitatively describe dynamical heterogeneity. In the
case of polymers, free volume models relate the macromolecular mobility to the free or accessible volume. The
relationship between dynamic heterogeneity and fluctuations of accessible volume seems straightforward. In the
present work, the heterogeneity of local dynamics in polymeric systems is analyzed by computer simulation with
the bond fluctuation model. The value of the accessible volume around each polymer chain is evaluated from
a snapshot or static structure at each system state, resulting in a distribution of accessible volume that reflects
system heterogeneity. The relationship between the average value and the standard deviation of free volume
distributions at different temperatures fits amaster curve for different systems, regardless of the specific inter- and
intramolecular interaction potentials that define each material. The dynamic slowdown around the glass transition
is accompanied by a clear evolution of the mean value and shape of the accessible free volume distribution. The
relative fluctuation of the dynamically accessible volume has been used as a parameter to quantitatively describe
heterogeneity. The fluctuation varies with temperature with remarkable differences between the liquid and glassy
states of the systems studied, presenting a peak at the glass transition temperature, which can be interpreted as a
reflection of the distribution of local glass transition temperatures.The support from the Ministry of Economy and Competitiveness (Spain) through Project No. MAT2016-76039-C4-1-R (including the FEDER financial support) is gratefully acknowledged. R.S.S. acknowledges the support of the Ministry of Education, Culture and Sports (Spain) through the program "Estancias de movilidad de profesores e investigadores seniores en centros extranjeros de ensenanza superior e investigacion 2016 under Grant No. PRX16/00208". CIBER-BBN is an initiative funded by the VI National R&D&I Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program. CIBER Actions are financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund.Torregrosa Cabanilles, C.; Molina Mateo, J.; Sabater I Serra, R.; Meseguer Dueñas, JM.; Gómez Ribelles, JL. (2018). Fluctuations of conformational mobility of macromolecules around the glass transition. Physical Review E. 97(6):062605-1-062605-7. https://doi.org/10.1103/PhysRevE.97.062605S062605-1062605-797
Non-Markovian Methods in Glass Transition
[EN] A model for the heterogeneity of local dynamics in polymer and other glass-forming materials is provided here. The fundamental characteristics of the glass transition phenomenology emerge when simulating a condensed matter open cluster that has a strong interaction with its heterogeneous environment. General glass transition features, such as non-exponential structural relaxations, the slowing down of relaxation times with temperature and specific off-equilibrium glassy dynamics can be reproduced by non-Markovian dynamics simulations with the minimum computer resources. Non-Markovian models are shown to be useful tools for obtaining insights into the complex dynamics involved in the glass transition phenomenon, including whether or not there is a need for a growing correlation length or the relationship between the non-exponentiality of structural relaxations and dynamic heterogeneity.The APC was funded by the Spanish Ministry of Science, Innovations, and Universities through the RTI2018-097862-B-C21 Project (including the FEDER financial support). CIBER-BBN is an initiative funded by the VI National R&D&I Plan 2008¿2011, Iniciativa
Ingenio 2010, Consolider Program. CIBER Actions are financed by the Instituto de Salud Carlos III with assistance
from the European Regional Development Fund.Torregrosa Cabanilles, C.; Molina Mateo, J.; Sabater I Serra, R.; Meseguer Dueñas, JM.; Gómez Ribelles, JL. (2020). Non-Markovian Methods in Glass Transition. Polymers. 12(9):1-14. https://doi.org/10.3390/polym12091997S11412
Computer simulation of the heterogeneity of segmental dynamics inamorphous polymers
The heterogeneity of local segmental dynamics in a polymer system is analyzed by computer simulation with the Bond Fluctuation Model. A different approach is proposed based on the concept of Dynamically Accessible Volume (DAV) due to the difficulties encountered in the characterization of this heterogeneity by means of the distribution of relaxation times. A DAV value is assigned to each polymer chain as the fraction of cells
in its surroundings that could be occupied in one Monte Carlo Step. In this way it is possible to relate the mobility of a chain with the accessible volume around it, due to the relationship between DAV and diffusion coefficient. As temperature decreases in equilibrium the DAV distribution shifts towards lower values, its width decreases and the number of frozen molecules increases. The methodology proposed also provides a
way of characterizing the evolution of segmental dynamics distribution in out of equilibrium states below glass transition temperatures.The authors would like to acknowledge the support provided by the Conselleria d'Educacio of the Generalitat Valenciana through the GV/2009/033 project. The translation of this paper was funded by the Universidad Politecnica de Valencia, Spain.Molina Mateo, J.; Torregrosa Cabanilles, C.; Sabater I Serra, R.; Meseguer Dueñas, JM.; Gómez Ribelles, JL. (2013). Computer simulation of the heterogeneity of segmental dynamics inamorphous polymers. Journal of Non-Crystalline Solids. 362:175-179. https://doi.org/10.1016/j.jnoncrysol.2012.11.034S17517936
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