17 research outputs found
La violencia de género contra las mujeres en Yucatán
This paper analyzes different types of violence: domestic violence, institutional violence and femicide to show how gender violence against Yucatan’s women is not only part of the domestic environment, but is also part of institutional environments and found in collective representations. To achieve this, the concept "gender violence against women" is used for analysis in combination with the spheres of violence as proposed by Johan Galtung: interpersonal or direct, structural and cultural/symbolic. Because women are objectified in these spheres, extreme violence and even feminicide are possible.Se analizan los tipos de violencia: doméstica, institucional y feminicida, usando el concepto de "violencia de género contra las mujeres", en combinación con las dimensiones de la violencia propuestas por Johan Galtung: interpersonal, estructural y cultural/simbólica, para demostrar que la violencia de género contra las mujeres en el estado de Yucatán, México, se ejerce no sólo en el hogar, sino también en las instituciones y en las representaciones colectivas, espacios en los que todavía se concibe a la mujer como un símbolo objeto, lo cual condiciona la aparición de conductas de violencia extrema que potencialmente desembocan en feminicidio
Modelado de un sistema de manufactura no convencional usando lógica difusa y algoritmos genéticos
De acuerdo con la literatura especializada, el algoritmo difuso de Mamdani es un aproximador universal, es decir, a través de la interacción de las reglas difusas que lo componen, un sistema de múltiples entradas y una salida puede aproximarse uniformemente a cualquier función aún definida en dominios compactos. La precisión de los aproximadores construidos por algoritmos difusos incide en la complejidad de estos, cuanto más precisos habrá un aumento en la complejidad, reflejado en un aumento de reglas difusas, las cuales, pueden ser construidas por medio de un sistema adaptativo neuro-difuso, además los conjuntos difusos obtenidos pueden ser optimizados por medio de un algoritmo genético con codificación real. Como caso de prueba es el modelado de la tasa de remoción de material de un proceso de maquinado electroquímico por descarga eléctrica, este es un proceso de fabricación no convencional donde el fresado o barrido se realiza mediante una disolución electrolítica, evitando el contacto físico entre la pieza de trabajo y el herramental Los resultados muestran que el enfoque propuesto permite obtener un modelo basado en un algoritmo difuso de Mamdani con menos conjuntos y reglas con respecto a un método de construcción basado en un proceso empírico
Untangling the Effects of Plant Genotype and Soil Conditions on the Assembly of Bacterial and Fungal Communities in the Rhizosphere of the Wild Andean Blueberry (Vaccinium floribundum Kunth)
Microbial communities in the rhizosphere influence nutrient acquisition and stress tolerance. How abiotic and biotic factors impact the plant microbiome in the wild has not been thoroughly addressed. We studied how plant genotype and soil affect the rhizosphere microbiome of Vaccinium floribundum, an endemic species of the Andean region that has not been domesticated or cultivated. Using high-throughput sequencing of the 16S rRNA and ITS region, we characterized 39 rhizosphere samples of V. floribundum from four plant genetic clusters in two soil regions from the Ecuadorian Highlands. Our results showed that Proteobacteria and Acidobacteria were the most abundant bacterial phyla and that fungal communities were not dominated by any specific taxa. Soil region was the main predictor for bacterial alpha diversity, phosphorous and lead being the most interesting edaphic factors explaining this diversity. The interaction of plant genotype and altitude was the most significant factor associated with fungal diversity. This study highlights how different factors govern the assembly of the rhizosphere microbiome of a wild plant. Bacterial communities depend more on the soil and its mineral content, while plant genetics influence the fungal community makeup. Our work illustrates plant–microbe associations and the drivers of their variation in a unique unexplored ecosystem from the Ecuadorian Andes
Estabilización de antioxidantes fenólicos bioactivos de origen natural: modificación de tocoferoles y resveratrol mediante acilación y glicosilación enzimática
Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 22-05-2009Antioxidants protect cells against the effects of harmful free radicals and play an
important role in preventing many human diseases (e.g. cancer, atherosclerosis,
neurodegeneration, inflammatory disorders, etc.) and aging itself. In addition, antioxidant
molecules are employed to prevent unsaturated oil products from becoming rancid during
storage, thus extending oil life. The modification of natural antioxidants in order to increase
their miscibility and/or stability towards the action of light and/or oxygen renders a series of
“semisynthetic” antioxidants with great value-added in the food, cosmetics and pharmaceutical
industries. These antioxidant derivatives may have impact not only as food preservatives but
also as components of functional foods and nutraceuticals.
Vitamin E (acting as a free radical scavenger) enhances the oxidative stability of
polyunsaturated fatty acids towards peroxidation and, to increase its stability, is generally
administered in the form of all-rac-α-tocopheryl acetate. Several approaches have been
described for the enzyme-catalysed synthesis of vitamin E acetate, e.g. the regioselective
hydrolysis of α-isophorone followed by reaction with isophytol. We have investigated the
modification of antioxidant vitamin E by acylation with vinyl acetate catalyzed by lipases.
Several parameters have been probed: (1) the source of the enzyme and its water content; (2)
the effect of the carriers; and (3) the composition of the reaction medium.
Resveratrol (trans-3,5,4'-trihydroxystilbene) is a polyphenolic phytochemical found in
grapes and wine that is biosynthesized in response to pathogenic attack or stress conditions. It
possesses a variety of antioxidant, anti-inflammatory, antitumour, cardioprotective and
immunomodulatory bioactivities. As part of our interest in regioselective biotransformations
of polyhydroxylated compounds, we have investigated the one-step enzymatic synthesis of
acylated or glycosylated resveratrol by enzyme-catalyzed processes. Such modifications could
render derivatives bearing different acyl- or glucosyl- groups in various positions, which may
beneficially affect their bioavailability and/or pharmacological properties. Although the three
phenolic groups of resveratrol at positions 3-, 5- and 4’- exhibit very similar chemical
reactivity, our results suggest that the regioselectivity of the acylation can be controlled by an
adequate selection of the biocatalyst. Regarding the glucosylation, we have investigated the
modification of resveratrol by glucosyltransferases, with starch as glucosyl donor. We studied
several parameters: (1) source of the enzyme, (2) presence of cosolvents, (3) reaction
temperature, (4) weight ratio donor (starch) : acceptor (resveratrol). We obtained 14 new
resveratrol glucosides, which were further characterized by HPLC-MS and NMR.
Using Rancimat test and Trolox Equivalent Antioxidant Capacity assay (TEAC), we
studied the antioxidant capability of all new derivatives of tocopherol and resveratrol. To
know the surfactant properties of resveratrol glucosides, we measured the variation of the
surface tension vs concentration in order to determinate the value of critical micellar
concentration.
Apart from this, we have characterized a new group of epoxy-activated supports, called
DilbeadsTM, based on methacrylate, to immobilize enzymes (Dilbeads TA, DVK, SZ, EZ, NK
and RS). Scanning electron microscopy, mercury intrusion porosimetry analysis and nitrogen
adsortion isotherms were employed. We have studied the distribution of a sterol sterase within
Dilbeads using fluorescence confocal microscopy and a FITC-labelled enzyme. Most of the
enzyme molecules are confined in a surface layer of 10.5 μm width. There is an apparent
diffusional limitations of enzyme molecules to reach the center of the bead particle, which can
be caused by several factors including: (1) the tortuosity of the pore structure; (2) the steric
hindrance exerted by the enzyme molecules that are immobilized in the shell of the particle.
1
Regioselective enzymatic hydrolysis of hexa-O-acetyl-lactal in a green non-aqueous medium
A purified lipase fraction from Rhizomucor miehei (RML) was immobilized and used to selectively hydrolyze hexa-O-acetyl-lactal (1) to penta-O-acetyl-3-hydroxylactal (2). The reaction was performed in low-water content tert-butanol (7% USP water), thus allowing the control of by-product formation. This solvent was superior to the established buffer/acetonitrile system in terms of reagent/product solubility, biocatalyst stability and environmental impact. The reaction was scaled up till 28 g/L (50 mM) affording the product 2 in very high yield (85%) and purity (98%)
Regioselective Deacetylation of Disaccharides via Immobilized Aspergillus niger Esterase(s)-catalyzed Hydrolysis in Aqueous and Non-aqueous Media
Purified lipase fractions from crude commercial extract of Aspergillus niger lipase (ANL) were selectively immobilized on hydrophobic supports. A significant percentage of esterase activity remains in the supernatant, derived from esterase(s) unable to become adsorbed onto the employed matrices. These residual proteins were covalently immobilized on epoxy-acrylic
resin. Immobilized hydrolases were tested in the hydrolysis of
acetylated disaccharides in water-cosolvent systems. ANL-Esterase was able to catalyze regioselective deprotection of acetylated beta-O-methyl lactoside in C-2 position and beta-O-methyl lactosaminide in C-3’ position. The hydrolyzed products, never reported before, can be considered new building blocks for the synthesis of oligosaccharides of biological relevance. Furthermore, preparative hydrolyses were also performed in tert-butanol. This solvent is compatible with ANL-esterase stability and it appears to be a novel and promising approach because of its green status
Dietary determinants of urinary molybdenum levels in Mexican women: a pilot study
Objective. This study determined the main dietary sources of urinary Mo concentrations in a sample of 124 pregnant women in Mexico. Materials and methods. Dietary data was collected during pregnancy, through a semi-qualitative food frequency questionnaire, with information of 84 foods. Urine Mo levels were determined by atomic absorption spectrometry, for at least two trimesters of pregnancy. The associations with Mo levels were estimated by generalized mixed effect regression models. Results. Between 5.8 to 12.7% of the samples were above the 95th percentile of urinary Mo distribution reported by National Health and Nutrition Examination Survey (NHANES) 2009-2010 for women (151 μg/L and 148 μg/g creatinine). After bootstrap resampling was conducted, women with high-consumption of hot peppers (β=1.34μg/g; 95% CI: 1.00-1.80; p= 0.05) had marginal higher urinary Mo concentration levels, creatinine adjusted,compared to women with low-consumption. Conclusion. Hot chili pepper consumption may contribute to body burden Mo levels in this population
Widening the pH Activity Profile of a Fungal Laccase by Directed Evolution
Unnatural selection: A fungal laccase was tailored by directed evolution to be active at neutral/alkaline pH. After five generations, the final mutant showed a broader pH profile while retaining 50 to 80 % of its activity at neutral pH.This study was based upon work funded by the EU Projects [NMP4‐SL‐2009–229255–3D‐Nanobiodevice, FP7‐KBBE‐2010–4–26537‐Peroxicats and COST Action CM0701] and a project of the Spanish Government [BIO2010–19697]. P.T.S. was supported by a grant from the “Comunidad de Madrid” and D.M.M. was supported by a JAE‐CSIC grant.Peer Reviewe
Untangling the Effects of Plant Genotype and Soil Conditions on the Assembly of Bacterial and Fungal Communities in the Rhizosphere of the Wild Andean Blueberry (<i>Vaccinium floribundum</i> Kunth)
Microbial communities in the rhizosphere influence nutrient acquisition and stress tolerance. How abiotic and biotic factors impact the plant microbiome in the wild has not been thoroughly addressed. We studied how plant genotype and soil affect the rhizosphere microbiome of Vaccinium floribundum, an endemic species of the Andean region that has not been domesticated or cultivated. Using high-throughput sequencing of the 16S rRNA and ITS region, we characterized 39 rhizosphere samples of V. floribundum from four plant genetic clusters in two soil regions from the Ecuadorian Highlands. Our results showed that Proteobacteria and Acidobacteria were the most abundant bacterial phyla and that fungal communities were not dominated by any specific taxa. Soil region was the main predictor for bacterial alpha diversity, phosphorous and lead being the most interesting edaphic factors explaining this diversity. The interaction of plant genotype and altitude was the most significant factor associated with fungal diversity. This study highlights how different factors govern the assembly of the rhizosphere microbiome of a wild plant. Bacterial communities depend more on the soil and its mineral content, while plant genetics influence the fungal community makeup. Our work illustrates plant–microbe associations and the drivers of their variation in a unique unexplored ecosystem from the Ecuadorian Andes
Untangling the Effects of Plant Genotype and Soil Conditions on the Assembly of Bacterial and Fungal Communities in the Rhizosphere of the Wild Andean Blueberry (Vaccinium floribundum Kunth)
Microbial communities in the rhizosphere influence nutrient acquisition and stress tolerance. How abiotic and biotic factors impact the plant microbiome in the wild has not been thoroughly addressed. We studied how plant genotype and soil affect the rhizosphere microbiome of Vaccinium floribundum, an endemic species of the Andean region that has not been domesticated or cultivated. Using high-throughput sequencing of the 16S rRNA and ITS region, we characterized 39 rhizosphere samples of V. floribundum from four plant genetic clusters in two soil regions from the Ecuadorian Highlands. Our results showed that Proteobacteria and Acidobacteria were the most abundant bacterial phyla and that fungal communities were not dominated by any specific taxa. Soil region was the main predictor for bacterial alpha diversity, phosphorous and lead being the most interesting edaphic factors explaining this diversity. The interaction of plant genotype and altitude was the most significant factor associated with fungal diversity. This study highlights how different factors govern the assembly of the rhizosphere microbiome of a wild plant. Bacterial communities depend more on the soil and its mineral content, while plant genetics influence the fungal community makeup. Our work illustrates plant–microbe associations and the drivers of their variation in a unique unexplored ecosystem from the Ecuadorian Andes