Pretratamiento enzimático en el prensado en frío: Influencia en los aceites de linaza, hueso de albaricoque y semilla de uva

A commercial enzyme preparation consisting of pectolytic, cellulotic and hemicellulotic enzymes was applied to the oil extraction by cold pressing from apricot kernel, flaxseed and grape seed. The effects of enzyme pre-treatment varied depending on the different oil seed used as raw material. Although the increase in free fatty acidity can be considered as a negative effect (from 0.37 to 0.52), the decrease in peroxide number and p-anisidine values, increase in oil yield (22.75%), higher levels of total carotenoids and tocopherols, as well as a remarkable increase in phenolic content (x1.68) and radical scavenging effect (including hydrophilic and lipophilic-induced and total antioxidant capacity) showed that the use of enzyme application in the cold pressing of apricot kernel oil would be beneficial. Many of these positive results could not be achieved in the pressing of flaxseed or grape seed oils under the same conditions. A high negative correlation (r=-92.2) was found between p-anisidine value and δ-tocopherol for grapeseed oil. Hydrophilic and lipophilic antioxidant capacity, total phenolics, and total carotenoids negatively correlated well (r values above 80) with peroxide values for apricot seed oil. Correlation results showed that carotenoids play an important role in the oxidative stability of the oils, where it was much more evident for apricot seed oil (r=-97.5).Se aplicó un preparado enzimático comercial que consta de enzimas pectolíticas, celulóticas y hemicelulóticas en la extracción de aceite de prensado en frío de albaricoque, linaza y semilla de uva. Los efectos del pretratamiento enzimático variaron dependiendo de las diferentes semillas oleaginosas como materia prima. Aunque el aumento de la acidez libre puede considerarse como un efecto negativo (de 0,37 a 0,52), la disminución del valor de peróxidos y de p-anisidina, el aumento del rendimiento de aceite (22,75%), niveles más altos de carotenoides totales y tocoferoles, además de un aumento notable en el contenido de fenoles (x1.68) y el efecto captador de radicales (incluida la capacidad antioxidante total e inducida por hidrófilos y lipófilos) mostraron que la aplicación de enzimas en el prensado en frío del aceite de hueso de albaricoque resulta beneficioso. Muchos de estos resultados positivos no se pudieron lograr al prensar los aceites de semillas de linaza y uva, en las mismas condiciones. Se encontró una alta correlación negativa (r = -92.2) entre el valor de p-anisidina y el δ-tocoferol para el aceite de semilla de uva. La capacidad antioxidante hidrófila y lipófila, los fenoles totales y carotenoides totales se correlacionaron negativamente bien (valores de r por encima de 80) con los valores de peróxido para el aceite de semilla de albaricoque. Los resultados de correlación mostraron que los carotenoides juegan un papel importante en la estabilidad oxidativa de los aceites, mucho más evidente para el aceite de hueso de albaricoque (r = -97,5)

A first-principles study of the structural, electronic, optical, and vibrational properties for paramagnetic half-Heusler compound TiIrBi by GGA and GGA

The structural, electronic, optical, and vibrational properties of half-Heusler compound TiIrBi have been investigated by using the Generalized Gradient Approximation (GGA) and GGA plus modified Becke and Johnson (GGA + mBJ) functional within the Density Functional Theory (DFT). The obtained formation enthalpies and energy-volume curves for the three different atomic arrangements (alpha, beta and gamma) show that gamma phase is the most energetically favorable phase. Additionally, among the paramagnetic (PM), ferromagnetic (FM), and antiferromagnetic (AFM) magnetic systems considered for the gamma-phase of this compound, the paramagnetic system is found to be the most stable. The spin-polarized electronic band calculations of the TiIrBi compound demonstrate that this material has a semiconductor nature in both the majority and minority spin channels with the direct bandgap of 0.56 and 0.87 eV using the GGA and GGA + mBJ approach, respectively. The obtained formation enthalpy and phonon dispersion curves for gamma-crystal structure of TiIrBi compound show that this material is both thermodynamically and dynamically stable. We have also examined the optical properties by computing the optical parameters such as real and imaginary parts of the dielectric function, refractive index, extinction coefficient, optical conductivity, and reflectivity of the half-Heusler compound TiIrBi in the photon energy range of 0-16 eV. The collected results indicate that the TiIrBi compound has a direct bandgap semiconductor, which makes it a convenient material for technological applications in optoelectronics

Modulation of inducible nitric oxide synthase expression by sumoylation

<p>Abstract</p> <p>Background</p> <p>In astrocytes, the inflammatory induction of Nitric Oxide Synthase type 2 (NOS2) is inhibited by noradrenaline (NA) at the transcriptional level however its effects on specific transcription factors are not fully known. Recent studies show that the activity of several transcription factors including C/EBPβ, which is needed for maximal NOS2 expression, is modulated by conjugation of the small molecular weight protein SUMO. We examined whether the expression of SUMO Related Genes (SRGs: SUMO-1, the conjugating enzyme Ubc9, and the protease SENP1) are affected by inflammatory conditions or NA and whether SUMO-1 regulates NOS2 through interaction with C/EBPβ.</p> <p>Methods</p> <p>Bacterial endotoxin lipopolysaccharide (LPS) was used to induce inflammatory responses including NOS2 expression in primary astrocytes. The mRNA levels of SRGs were determined by QPCR. A functional role for SUMOylation was evaluated by determining effects of over-expressing SRGs on NOS2 promoter and NFκB binding-element reporter constructs. Interactions of SUMO-1 and C/EBPβ with the NOS2 promoter were examined by chromatin immunoprecipitation assays. Interactions of SUMO-1 with C/EBPβ were examined by immunoprecipitation and Western blot analysis and by fluorescence resonance energy transfer (FRET) assays.</p> <p>Results</p> <p>LPS decreased mRNA levels of SUMO-1, Ubc9 and SENP1 in primary astrocytes and a similar decrease occurred during normal aging in brain. NA attenuated the LPS-induced reductions and increased SUMO-1 above basal levels. Over-expression of SUMO-1, Ubc9, or SENP1 reduced the activation of a NOS2 promoter, whereas activation of a 4 × NFκB binding-element reporter was only reduced by SUMO-1. ChIP studies revealed interactions of SUMO-1 and C/EBPβ with C/EBP binding sites on the NOS2 promoter that were modulated by LPS and NA. SUMO-1 co-precipitated with C/EBPβ and a close proximity was confirmed by FRET analysis.</p> <p>Conclusion</p> <p>Our results demonstrate that SUMOylation regulates NOS2 expression in astrocytes, and point to modification of C/EBPβ as a possible mechanism of action. Targeting the SUMOylation pathway may therefore offer a novel means to regulate inflammatory NOS2 expression in neurological conditions and diseases.</p

Modèles en iles pour le réglage automatique de paramètres : application au problème du bandit manchot

National audienc

Parameter Setting with Dynamic Island Models

In this paper we proposed the use of a dynamic island model which aim at adapting parameter settings dynamically. Since each island corresponds to a specific parameter setting, measuring the evolution of islands populations sheds light on the optimal parameter settings efficiency throughout the search. This model can be viewed as an alternative adaptive operator selection technique for classic steady state genetic algorithms. Empirical studies provide competitive results with respect to other methods like automatic tuning tools. Moreover, this model could ease the parallelization of evolutionary algorithms and can be used in a synchronous or asynchronous way

Non stationary operator selection with island models

The purpose of adaptive operator selection is to choose dynamically the most suitable variation operator of an evolutionary algorithm at each iteration of the search process. These variation operators are applied on individuals of a population which evolves, according to an evolutionary process, in order to find an optimal solution. Of course the efficiency of an operator may change during the search and therefore its application should be precisely controlled. In this paper, we use dynamic island models as operator selection mechanisms. A sub-population is associated to each operators and individuals are allowed to migrate from one sub-population to another one. In order to evaluate the performance of this adaptive selection mechanism, we propose an abstract operator representation using fitness improvement distributions that allow us to define non stationary operators with mutual interactions. Our purpose is to show that the adaptive selection is able to identify not only good operators but also suitable sequences of operators

Pourquoi rendre les modèles en iles autonomes ?

Date du colloque&nbsp;: 04/2012National audienc

Theoretical research on structural, electronic, mechanical, lattice dynamical and thermodynamic properties of layered ternary nitrides Ti(2)AN (A = Si, Ge and Sn)

WOS: 000449621500085First-principles density functional theory (DFT) calculations within generalized gradient approximation (GGA) are carried out to investigate the structural, electronic, mechanical, lattice dynamical and thermodynamic properties of Ti(2)AN (A = Si, Ge and Sn) MAX phases. The optimized geometrical parameters such as lattice constants (a, c) and the internal coordinates have been calculated. Electronic band structure and corresponding density of states (DOS) have been obtained. The analysis of the band structures and density of states have shown that these compounds are electrical conductors. The elastic constants have been ascertained using the stress-strain method. The isotropic elastic moduli, known as bulk modulus (B), shear modulus (G), young's modulus (E), poisson's ratio (nu), vickers hardness (H-nu) and linear compressibility coefficients (alpha) have been studied within framework of the Voigt-Reuss-Hill approximation for ideal polycrystalline Ti(2)AN (A = Si, Ge and Sn) MAX aggregates. Furthermore, the phonon dispersion curves as well as accompanying phonon density of states have been comprehensively computed. And also raman and infrared modes at the G point have been obtained. Within the thermodynamic properties, specific heat capacity, entropy, helmholtz free energy and internal energy changes were analyzed depending on the temperature of Ti(2)AN (A = Si, Ge and Sn) compounds. The obtained results are presented in comparison with present theoretical data for Ti2SiN. This is the first quantitative theoretical study of the electronic properties and other properties for Ti2GeN and Ti2SnN compounds and therefore theoretical results for these compounds need to be verified experimentally. (C) 2018 Elsevier B.V. All rights reserved

Use of immediate-early gene expression to map relationships between limbic structures supporting memory

This thesis explores the influence of brain regions within the "extended hippocampal memory system" on the activity of the retrosplenial cortex in the rat. One of the first goals was to use lesion studies to improve the understanding of the vulnerability of the retrosplenial cortex, especially in the context of diencephalic and temporal lobe amnesia. The second was to assess what are the brain areas within the temporal lobe involved in object recognition and how they interact. These two objectives were made possible by visualising immediate-early gene expression. By combining this technique with lesions, distal effects of different lesions (hippocampus, mammillothalamic tract and fornix) on the activity of the retrosplenial cortex were measured. For object recognition, the immediate-early gene imaging enabled the assessment of normal brain activity in rats associated with behavioural discrimination of novelty. The lesion studies provide information about the specific and common vulnerability of the retrosplenial cortex, as all three distal lesions resulted in a decrease of immediate-early gene activity in the retrosplenial cortex. In addition, these findings unify diencephalic amnesia with temporal amnesia, and emphasize the need to study networks or systems instead of individual structure. The immediate-early gene/object recognition experiment implicated the caudal part of the perirhinal cortex (and Te2) and of the hippocampus in object recognition, and highlighted the importance of mapping brain region relationships within a connected system. Taken together, these experiments provide clear support for the concept of an extended hippocampal memory system, but also show how this system may interact with other structures involved in different forms of memory. The findings underlie the potential afforded by use of immediate-early gene expression techniques in animal studies.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A dynamic island model for adaptive operator selection

In this paper we propose a generic framework for Dynamic Island Models, which can be used as an original approach for the adaptive selection of operators in evolutionary algorithms. Assigning a variation operator to each island, we show that the dynamic regulation of migrations, which takes into account the pertinence of recent migrations, distributes the individuals on the most promising islands, i.e., the most efficient operators, at each stage of the search. The efficiency of this approach is assessed on the One-Max problem by comparing theoretical expected results to those obtained by our dynamic island model. Experiments show that the model provides the expected behavior