Factores asociados al consumo abusivo de alcohol en chicos y chicas mexicanos

En el presente estudio se propuso analizar los factores asociados con el consumo abusivo de alcohol en chicos y chicas mexicanos. Se trata de un estudio con 1.245 adolescentes escolarizados, de ambos sexos, de dos centros educativos de secundaria y dos preuniversitarios, con edades comprendidas entre los 12 y 17 años de edad. Se utilizó un muestreo probabilístico estratifi cado, considerando la proporción del alumnado por grado escolar, grupos y turnos. Los resultados muestran que el tener amigos consumidores de alcohol incrementa signifi cativamente el consumo tanto en chicos como en chicas; en los chicos y no en las chicas el tener padres y hermanos consumidores tiene un efecto de potenciación del consumo abusivo. En las chicas y no en los chicos el consumo abusivo se relaciona con una pobre autoestima emocional y, fi nalmente, el fracaso/reprobación escolar se relaciona con el consumo abusivo en chicos y no en chicas. Estos resultados se discuten en función de los estudios más relevantes en la temática de esta investigación y se hace énfasis en sus limitaciones metodológicas.The present study is set out to analyze the factors associated with the abusive consumption of alcohol in Mexican boys and girls. 1,245 teenagers from both genders where studied, in two High School educational centers and two gyms, between 12 and 17 years old. We used a sampling stratifi ed probabilistic, considering the proportion of students by grade level, groups and shifts. The results show that alcohol consumers' friends signifi cantly increases the consumption both in boys as in girls; boys and not girls having parents and other relatives consumers have the effect of empowerment abusive consumption. While in girls and not in boys the abusive consumption is related to a poor emotional and low self-esteem. Finally, school failure is related to the abusive consumption in boys while not in girls. These results are discussed in the light of the relevant studies in the theme of this research and emphasis is made on their methodological limitations

Control de la frecuencia cardíaca durante la competición en el fútbol profesional

Una de las claves del éxito en el fútbol profesional es la correcta y adecuada planificación de las cargas de entrenamiento. Cualquier figura que interviene sobre el rendimiento del deportista, sea entrenador, preparador físico, psicólogo, médico, etc., necesita planificar en base a zonas de entrenamiento específicas debido al corto periodo de tiempo de preparación (pretemporada) para alcanzar rendimientos óptimos inmediatos (Jiménez, 1993)

Plant cell culture strategies for the production of natural products

Plants have evolved a vast chemical cornucopia to support their sessile lifestyles. Man has exploited this natural resource since Neolithic times and currently plant-derived chemicals are exploited for a myriad of applications. However, plant sources of most high-value natural products (NPs) are not domesticated and therefore their production cannot be undertaken on an agricultural scale. Further, these plant species are often slow growing, their populations limiting, the concentration of the target molecule highly variable and routinely present at extremely low concentrations. Plant cell and organ culture constitutes a sustainable, controllable and environmentally friendly tool for the industrial production of plant NPs. Further, advances in cell line selection, biotransformation, product secretion, cell permeabilisation, extraction and scale-up, among others, are driving increases in plant NP yields. However, there remain significant obstacles to the commercial synthesis of high-value chemicals from these sources. The relatively recent isolation, culturing and characterisation of cambial meristematic cells (CMCs), provides an emerging platform to circumvent many of these potential difficulties. [BMB Reports 2016; 49(3): 149-158

Análisis psicosocial del consumo de alcohol en adolescentes mexicanos

RESUMEN El objetivo del presente estudio fue realizar un análisis psicosocial del consumo de alcohol en adolescentes mexicanos, considerando de forma simultánea las variables personales, familiares, escolares y sociales. Se realizó un estudio de tipo explicativo. La muestra estuvo conformada por 1.245 adolescentes de ambos sexos, procedentes de dos centros educativos de secundaria y dos de preparatoria, con edades comprendidas entre los 12 y los 17 años. Se realizó un modelo de ecuaciones estructurales que explicó el 66 % de la varianza y se exploró el efecto moderador del género. Los resultados se discuten en función de los estudios más relevantes en la temática de esta investigación. ABSTRACT The objective of the present study was to analyze the psychosocial alcohol consumption in Mexican adolescents, taking into account simultaneously personal, family, school and social variables. The type of study is explanatory. The sample consisted of 1245 adolescents girls and boys form two secondary and preparatory schools, with ages between 12 and 17 years old. A structural equations model explained 66% of the variance and also it was explored the moderating effect of gender. The results are discussed in terms of the relevant studies on the subject of this investigation

S-nitrosylation of the zinc finger protein SRG1 regulates plant immunity

Upon pathogen infection plants accumulate nitric oxide which subsequently regulates defence gene expression. Here, the authors show that S-nitrosylation of the zinc finger transcription factor SRG1 affects transcriptional suppression and contributes to activation of defence responses

In situ solid-liquid extraction enhances recovery of taxadiene from engineered Saccharomyces cerevisiae cell factories

Microbial cell factories express diverse heterologous pathways for the production of a wide range of valuable natural products. However, the recovery and purification of such compounds is a major bottleneck in commercialization. In this study, a novel in situ solid phase adsorption strategy was investigated for enhanced recovery of taxadiene, a precursor to the blockbuster anticancer drug, paclitaxel, from engineered Saccharomyces cerevisiae. A synthetic adsorbent resin (HP-20) was employed to efficiently sequester taxadiene as it was secreted during growth and a carefully optimized desorption solvent was applied following cultivation to maximize recovery of both secreted and intracellular taxadiene, across a range of scales (2 – 250 mL). Resin concentration was found to have an impact on cellular growth, with the high concentration of 12 % (w/v) resulting in fragmentation of the resin beads, which was detrimental to growth. The optimal resin concentration and desorption solvent combination elucidated at microscale (2 mL) resulted in a two-fold improvement in taxadiene titer to 61 ± 8 mg/L, compared to the traditional liquid-liquid extraction approach (dodecane overlay). Taxadiene was found to be distributed evenly between resin beads and biomass. Performance of the optimal process was subsequently investigated through scale-up using controlled mini-bioreactors (250 mL). Here, a comparable taxadiene titer of 76 ± 19 mg/L was achieved despite a 125-fold scale-up in cultivation volume. This represented a 1.4-fold improvement in taxadiene recovery compared to previous mini-bioreactor scale cultivations using the dodecane overlay extraction approach

Toxic Determination of Cry11 Mutated Proteins Obtained Using Rational Design and Its Computational Analysis

Cry11 proteins are toxic to Aedes aegypti, the vector of dengue, chikungunya, and Zika viruses. Cry11Aa and Cry11Bb are protoxins, which when activated present their active-toxin form in two fragments between 30 and 35 kDa respectively. Previous studies conducted with Cry11Aa and Cry11Bb genes using DNA shuffling generated variant 8, which presented a deletion in the first 73 amino acids and one at position 572 and 9 substitutions including L553F and L556W. In this study, variant 8 mutants were constructed using site-directed mutagenesis, resulting in conversion of phenylalanine (F) and tryptophan (W) to leucine (L) at positions 553 and 556, respectively, producing the mutants 8F553L, 8W556L, and 8F553L/8W556L. Additionally, two mutants, A92D and C157R, derived from Cry11Bb were also generated. The proteins were expressed in the non-crystal strain BMB171 of Bacillus thuringiensis and subjected to median-lethal concentration (LC 50) tests on first-instar larvae of A. aegypti. LC 50 analysis showed that the 8F553L, 8W556L, 8F553L/8W556L, and C157R variants lost their toxic activity (&gt;500 ng·mL -1), whereas the A92D protein presented a loss of toxicity of 11.4 times that of Cry11Bb. Cytotoxicity assays performed using variant 8, 8W556L and the controls Cry11Aa, Cry11Bb, and Cry-negative BMB171 on the colorectal cancer cell line SW480 reported 30-50% of cellular viability except for BMB171. Molecular dynamic simulations performed to identify whether the mutations at positions 553 and 556 were related to the stability and rigidity of the functional tertiary structure (domain III) of the Cry11Aa protein and variant 8 showed the importance of these mutations in specific regions for the toxic activity of Cry11 against A. aegypti. This generates pertinent knowledge for the design of Cry11 proteins and their biotechnological applications in vector-borne disease control and cancer cell lines. </p