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The consideration of specific needs of gifted students in the school is an issue of equality of opportunities in relation to average and low capacity students. This topic, too known from the psychopedagogical field, has been considered in a different way in several countries, and it has experienced important changes from the educational politics in the last few years. This document intends to actualise and carry out a comparative study on its situation in Latin American countries and to assemble the specific information belonging to the educational institutions: administrations, ministries, universities, institutes, and so on, engaged in these students education There has been, and there is, a very different focus on legislation and educational interventions for this kind of students in the Latin American countries. Besides, there is a lack of comparative studies on what different countries are doing in this field. The analysis is carried out on three variables: legislation, educational interventions and research. The study ends with some conclusions and proposals to improve the programs and the political decisions. [ABSTRACT FROM AUTHOR]

Abstract Modern life involves chronic circadian disruption through artificial light and these disruptions are associated with numerous mental and physical health maladies. Because the developing nervous system is particularly vulnerable to perturbation, we hypothesized that early-life circadian disruption would negatively impact offspring development and adult function. Pregnant mice were subjected to chronic circadian disruption from the time of uterine implantation through weaning. To dissociate in utero from postnatal effects, a subset of litters was cross-fostered at birth from disrupted dams to control dams and vice versa. Postnatal circadian disruption was associated with reduced adult body mass, social avoidance, and hyperactivity. In utero disruption resulted in more pronounced social avoidance and hyperactivity, phenotypes not abrogated by cross-fostering to control mothers. To examine whether circadian disruption affects development by acting as an early life stressor, we examined birthweight, litter size, maternal cannibalism, and epigenetic modifications. None of these variables differed between control and disrupted dams, or resembled patterns seen following early-life stress. Our findings indicate that developmental chronic circadian disruption permanently affects somatic and behavioral development in a stage-of-life-dependent manner, independent of early life stress mechanisms, underscoring the importance of temporal structure during development, both in utero and early postnatal life.

One of the most important structural parameters involved in the characterization of the void space of soils is the pore size distribution. In this work, a nitrogen adsorption method is presented as an alternative to determine the mesopore contribution of slit-shaped pores to the abovementioned parameter in montmorillonite-containing soils. The mesopore size structural parameter obtained via this sorption method is related to montmorillonite d 001 interlayer distances proceeding from either X-ray or electron diffraction analysis, if only by assuming during sorption analysis that mesopores resident inside clay grains adopt slit-shaped geometries. Mineralogical analysis and determination of some important geotechnical properties of these montmorillonite-containing soils complement the preceding sorption and structural studies. [ABSTRACT FROM AUTHOR]

Background: The proper establishment of hypothalamic feeding circuits during early development has a profound influence on energy homeostasis, and perturbing this process could predispose individuals to obesity and its associated consequences later in life. The maturation of hypothalamic neuronal circuitry in rodents takes place during the initial postnatal weeks, and this coincides with a dramatic surge in the circulating level of leptin, which is known to regulate the outgrowth of key neuronal projections in the maturing hypothalamus. Coincidently, this early postnatal period also marks the rapid proliferation and expansion of astrocytes in the brain. Methods: Here we examined the effects of leptin on the proliferative capacity of astrocytes in the developing hypothalamus by treating postnatal mice with leptin. Mutant mice were also generated to conditionally remove leptin receptors from glial fibrillary acidic protein (GFAP)-expressing cells in the postnatal period. Results and conclusions: We show that GFAP-expressing cells in the periventricular zone of the 3rd ventricle were responsive to leptin during the initial postnatal week. Leptin enhanced the proliferation of astrocytes in the postnatal hypothalamus and conditional removal of leptin receptors from GFAP-expressing cells during early postnatal period limited astrocyte proliferation. While increasing evidence demonstrates a direct role of leptin in regulating astrocytes in the adult brain, and given the essential function of astrocytes in modulating neuronal function and connectivity, our study indicates that leptin may exert its metabolic effects, in part, by promoting hypothalamic astrogenesis during early postnatal development.

[Objetivo] El objetivo es documentar el proceso de diseño, implementación y evaluación de una secuencia de enseñanza-aprendizaje basada en el modelo 5E para la enseñanza de los conceptos de calor y temperatura. [Metodología] Utilizando la metodología de investigación basada en el diseño se diseñó, implemento y evaluó la aplicación de una secuencia de enseñanza-aprendizaje a estudiantes con edades entre 13 y 15 años, de educación secundaria. Participaron 19 estudiantes de dos escuelas en México organizados en dos grupos, uno por cada escuela. Utilizando pretest y postest, se registraron datos cuantitativos asociadas a los conocimientos de los estudiantes y datos cualitativos, obtenidos durante las sesiones con los estudiantes, asociados al uso de los conceptos de calor y temperatura para explicar fenómenos naturales. Los datos cuantitativos fueron analizados con la prueba Shapiro-Wilk y ANOVA de dos factores, utilizando JASP con p≤0.05. Además, se realizó una triangulación con datos cualitativos para dar soporte a las conclusiones. [Resultados] Los resultados obtenidos muestran efectos positivos relacionados con los conocimientos que alcanzan los estudiantes durante la implementación. También se encuentran efectos positivos en las evidencias cualitativas donde se observa que la integración conceptual que logran los estudiantes logra explicar de forma coherente y compleja los fenómenos naturales relacionados con los conceptos de calor y temperatura. [Conclusiones] En conclusión, la secuencia de enseñanza-aprendizaje diseñada alcanza las metas de aprendizaje propuestas relacionadas con los conceptos de calor y temperatura. Se incluye un listado de principios de diseño que pretenden ser una guía para otros docentes interesados en adaptar esta experiencia a sus contextos locales.

The aim of this study was to assess the relationship of the rs11191439 and rs3740393 polymorphisms of the Arsenite Methyltransferase (As3MT) gene with the arsenic urinary excretion profiles in a population in northern Mexico. A crosssectional study was conducted with 102 participants between the ages of 14 and 75 in Comarca Lagunera, Mexico. Speciation of the arsenic urinary metabolites was determined, and DNA was extracted; analysis and amplification of the polymorphisms was made by PCR in real time. A descriptive analysis was carried out and the differences in the urinary arsenic concentrations were assessed according to sex and genotype. The median concentration of arsenic in water was 82 μg/L; the levels of urinary excretion of dimethylarsinic acid (DMA) were higher in women than in the men. The carriers of the CC genetic variant of the As3MT (rs3740393) gene showed higher urinary concentrations of methylarsinic acid (p=0.01) and DMA (p=0.05). [ABSTRACT FROM AUTHOR]

El presente artículo de investigación muestra un análisis de un suelo expansivo del Residencial Santa Fe, en la zona Este de la ciudad de Santiago de Querétaro, México, con el fin de determinar el periodo anual en el que es más conveniente el inicio de la autoconstrucción de una vivienda de interés social. Las propiedades mecánicas del suelo (presión de expansión, ángulo de fricción y cohesión) se determinan mediante pruebas geotécnicas para conocer los posibles movimientos diferenciales del terreno y así evitar las deficiencias a corto plazo que estas casas sufren en nuestro país, obteniendo que el lapso idóneo para la edificación es octubre-marzo, caso contrario, en el periodo abril-septiembre es crítico, por lo que los cimientos aumentan en costo.

The Mexican asphalt paving industry is increasingly interested in using reclaimed asphalt pavement (RAP) to produce hot mix asphalt (HMA) due to its economic and environmental advantages. However, an ill-defined methodology for integrating RAP into the HMA mix design has hindered its use. This paper investigates how compaction energy affects both rejuvenated and non-rejuvenated recycled HMA mixtures. A Superpave gyratory compactor was used to determine the optimal binder content and find a balance between flexibility and stiffness that meets cracking and rutting resistance requirements. Various recycled HMA mixtures were subjected to different compaction energy levels (75, 100, and 125 gyros), different RAP contents (15%, 30%, and 45%), and various dosages (10%, 15%, and 36%) of the rejuvenating additive Maro-1000®, following the blending chart. Performance was evaluated using the Hamburg wheel tracking test (HWTT) and the fracture energy flexibility index test (I-FIT). The results demonstrate that mixtures with RAP, a rejuvenating admixture, and varying compaction energies exhibit favorable mechanical behavior. However, both rejuvenated and non-rejuvenated mixes with 15% RAP showed performance comparable to conventional mixtures. They improved stiffness by up to 46% while reducing the flexibility index to 25%, striking a balanced equilibrium between rutting resistance and cracking susceptibility.

A porous-solid model based on the grain and pore size distributions of the soil is coupled with a mechanical model to simulate the soil-water retention curves while the material is deforming. During the determination of the main drying curve, the soil is subjected to high suctions which induce important volumetric deformations. These volumetric deformations modify the pore size distribution of the sample affecting both the drying and the wetting retention curves. Although, most deformation occurs at drying, the drying curve is only slightly affected by soil deformation. In contrast, the wetting curve shows important shifting when volume change is considered. [ABSTRACT FROM AUTHOR]

The natural production of the native flat oyster Ostrea edulis and the production of seed in hatcheries are insufficient to meet demand. Several projects have recently been developed to optimise flat oyster production and to establish a reliable protocol for broodstock conditioning in hatcheries. In this sense, the positive effect of a gradient of temperature and a gradient of daylight on the gonadal development, spawning and larval production of O. edulis during winter and autumn conditioning was previously confirmed. No other study has yet been optimised the effect of other factors on flat oyster conditioning.This work examines the combined effect of two important factors on broodstock conditioning, namely the food ration and the water flow rate, for the first time. Furthermore, the bacteriological load of oyster broodstock and its influence on O. edulis conditioning had not been studied before. The results showed that the broodstock conditioned with a food ration of 3% produced the highest number of viable larvae. Oysters conditioned at a flow rate of 3 L h−1 oyster−1 had the highest mortality rate, coinciding with the highest levels of vibrio and heterotrophic bacteria in both meat and intervalvar fluid. The best larval production results were obtained when the 3% food ration was combined with a water flow rate of 2 L h−1 oyster−1.

The mussel Mytilus galloprovincialis is one of the most important aquaculture species in Europe. Its main production problem is the accumulation of toxins during coastal blooms, which prevents mussel commercialization. P-glycoprotein (ABCB1/MDR1/P-gp) is part of the multixenobiotic resistance system in aquatic organisms, and okadaic acid, the main DSP toxin, is probably a substrate of the P-gp-mediated efflux. In this study, the presence and possible role of P-gp in the okadaic acid detoxification process was studied in M. galloprovincialis. We identified, cloned, and characterized two complete cDNAs of mdr1 and mdr2 genes. MgMDR1 and MgMDR2 predicted proteins had the structure organization of ABCB full transporters, and were identified as P-gp/MDR/ABCB proteins. Furthermore, the expression of mdr genes was monitored in gills, digestive gland, and mantle during a cycle of accumulation-elimination of okadaic acid. Mdr1 significantly increased its expression in the digestive gland and gills, supporting the idea of an important role of the MDR1 protein in okadaic acid efflux out of cells in these tissues. The expression of M. galloprovincialismrp2, a multidrug associated protein (MRP/ABCC), was also monitored. As in the case of mdr1, there was a significant induction in the expression of mrp2 in the digestive gland, as the content of okadaic acid increased. Thus, P-gp and MRP might constitute a functional defense network against xenobiotics, and might be involved in the resistance mechanisms to DSP toxins.

The Trans-Mexican Volcanic Belt (TMVB), located in central Mexico, is an area for which low to moderate seismic risk is considered. This is based on the limited instrumental data available, even though large historical earthquakes have damaged some urban centers in the past. However, site effects is an aspect that must be considered in estimating risk, because there are some instances of important amplifications that have been documented with serious effects. In this work, ambient noise and earthquake records from 90 seismic permanent and temporary stations are used to analyze site response in the TMVB. The results obtained show a heterogeneous range in the value of the fundamental frequency. When possible, a comparison was made of the results obtained from ambient noise and earthquake records. In almost all these comparisons, no significant differences were observed in terms of the fundamental frequency. However, there were some stations with a flat average HVSR ambient noise curve that contradicted earthquake data results, which showed peaks at some frequencies. Our results are a first step towards categorizing the different site responses in the TMVB but in order to provide finer details, it is necessary to improve the actual monitoring conditions.

Ante el fenómeno de la migración, tanto los familiares que se van como los que se quedan, se ven influenciados de alguna manera. Los niños como actores sociales, también viven y observan la migración directa e indirectamente. Ellos de acuerdo al contexto y a su propio proceso psico-evolutivo tienen una manera de narrar lo que saben y viven. La presente investigación hace un acercamiento a estos procesos socioemocionales a través de la narrativa y el dibujo de 653 niños de 3º a 6º de primaria, de los estados de Zacatecas, Michoacán, Hidalgo, Jalisco y Yucatán. Se utilizó la investigación narrativa en donde ellos dibujaban su interpretación de la migración y relataban una historia al respecto. Se analizó la información con categorías preestablecidas y emergentes, encontrando que los niños expresan principalmente las emociones de tristeza y felicidad, emociones que están asociadas a situaciones sociales donde hay peligro y amenaza ante la migración y donde se puede triunfar al vencer obstáculos y al lograr el objetivo de migrar. Finalmente, se constató que estos niños tienen una consciencia social de otro tanto de su dolor, alegría como de las injusticias vividas.

Some diatom species of the genus Pseudo-nitzschia produce the toxin domoic acid. The depuration rate of domoic acid in Pecten maximus is very low; for this reason, king scallops generally contain high levels of domoic acid in their tissues. A transcriptomic approach was used to identify the genes differentially expressed in the P. maximus digestive gland after the injection of domoic acid. The differential expression analysis found 535 differentially expressed genes (226 up-regulated and 309 down-regulated). Protein–protein interaction networks obtained with the up-regulated genes were enriched in gene ontology terms, such as vesicle-mediated transport, response to stress, signal transduction, immune system process, RNA metabolic process, and autophagy, while networks obtained with the down-regulated genes were enriched in gene ontology terms, such as response to stress, immune system process, ribosome biogenesis, signal transduction, and mRNA processing. Genes that code for cytochrome P450 enzymes, glutathione S-transferase theta-1, glutamine synthase, pyrroline-5-carboxylate reductase 2, and sodium- and chloride-dependent glycine transporter 1 were among the up-regulated genes. Therefore, a stress response at the level of gene expression, that could be caused by the domoic acid injection, was evidenced by the alteration of several biological, cellular, and molecular processes.

Introducción: La incapacidad temporal (IT) constituye un proceso de origen multifactorial. Objetivo: Evaluar el proceso de IT en relación con la enfermedad, estado de salud, satisfacción laboral, perfil de locus de control y características sociodemográficas. Método: Estudio observacional de cohortes prospectivo sobre 404 pacientes en IT. Realizamos un análisis de supervivencia describiendo la evolución de los participantes en cuanto a su permanencia en IT. Resultados: La permanencia media en IT fue significativamente superior (p

En los Altos de Jalisco, México, la migra- ción y la actividad agropecuaria son acti- vidades tradicionales con impacto econó- mico y social en la cotidianidad. Por ello se llevó a cabo un estudio cualitativo so- bre la percepción y experiencia de nueve empleadores de una empresa agroindus- trial respecto al fenómeno migratorio en la región, así como los costos y benefi cios que asocian al mismo. Los empleadores observan la disminución de emigrantes y el aumento de deportados. Identifi can un aumento de mujeres e hijos jóvenes ingre- sando a trabajar en la empresa. Como im- pacto negativo destacan: difi cultades de adaptación de los retornados, adquisición de costumbres diferentes, distanciamien- to o abandono familiar y falta de envío de remesas. Aprecian el desarrollo de nuevas cualidades y mayores exigencias hacia la empresa en los trabajadores migrantes de retorno.

Some species of the genus Pseudo-nitzschia produce the toxin domoic acid, which causes amnesic shellfish poisoning (ASP). Given that bivalve mollusks are filter feeders, they can accumulate these toxins in their tissues. To elucidate the transcriptional response of the queen scallop Aequipecten opercularis after exposure to domoic acid-producing Pseudo-nitzschia, the digestive gland transcriptome was de novo assembled using an Illumina HiSeq 2000 platform. Then, a differential gene expression analysis was performed. After the assembly, 142,137 unigenes were obtained, and a total of 10,144 genes were differentially expressed in the groups exposed to the toxin. Functional enrichment analysis found that 374 Pfam (protein families database) domains were significantly enriched. The C1q domain, the C-type lectin, the major facilitator superfamily, the immunoglobulin domain, and the cytochrome P450 were among the most enriched Pfam domains. Protein network analysis showed a small number of highly connected nodes involved in specific functions: proteasome components, mitochondrial ribosomal proteins, protein translocases of mitochondrial membranes, cytochromes P450, and glutathione S-transferases. The results suggest that exposure to domoic acid-producing organisms causes oxidative stress and mitochondrial dysfunction. The transcriptional response counteracts these effects with the up-regulation of genes coding for some mitochondrial proteins, proteasome components, and antioxidant enzymes (glutathione S-transferases, thioredoxins, glutaredoxins, and copper/zinc superoxide dismutases).

El propósito de la investigación fue analizar el cambio actitudinal en los estudiantes de pregrado acerca del uso de la plataforma virtual como apoyo al desarrollo de un curso de formación disciplinar impartido en la modalidad presencial, considerando los aportes de Vygotsky (1988), Ausubel (1983), Pozo (2001), Coll (2007), Marqués (2001; 2003), Prensky (2001), Vilaseca y Meseguer (2000), entre otros. El estudio corresponde a un estudio de caso, enmarcado en el paradigma cualitativo, que utilizó como técnicas el grupo focal y dos encuestas que permitieron apreciar la opinión de los estudiantes del dominio las TIC y la actitud por el uso de la plataforma virtual como apoyo a la clase presencial o Aprendizaje Semipresencial. Contó con la participación de 35 estudiantes de Licenciatura en Preescolar en la Universidad del Magdalena en Santa Marta (Colombia) en el periodo académico 2012-I. Se evidenció que la interacción presencial no es el único canal comunicativo que garantiza aprendizajes efectivos y más allá del incremento de la habilidad tecnológica en los estudiantes, se contribuyó a elevar la autoestima, a mejorar el tiempo de dedicación en la realización de actividades complementarias a los encuentros presenciales. A los docentes les permite establecer las pautas para participar tanto en el entorno presencial como el virtual, la asignación de ejercicios y trabajos para presentar en cada espacio, los plazos de publicación de actividades y los criterios de evaluación.Descriptores: Formación del profesorado, aprendizaje semipresencial, actitudes, plataformas virtuales.The purpose of this research was to analyze the attitudinal change in undergraduate students about their use of the virtual platform to support the development of a training course in the classroom, considering the contributions of Vygotsky (1988), Ausubel (1983), Pozo (2001), Coll (2007), Marqués (2001; 2003), Prensky (2001), Vilaseca y Meseguer (2000). Is a case study, framed within the qualitative paradigm, which used as techniques a focus group and two surveys designed to appreciate the opinions and attitudes from the students on the TIC’s in the use of a virtual platform to support the Blended Learning. The research involved 35 undergraduate students of Preschool education in the Universidad del Magdalena in Santa Marta (Colombia) on the first academic period of 2012. It was evident that the clasroom interaction is not the only way of communication that ensures an effective learning and increase the students abilities beyond the tecnological system, improving time commitment in the follow-up activities to face meetings. The research also allowed teachers to establish guidelines to participate not only in the classroom, but on a virtual environment, assignig exercises and assignments to be presented in each space, the due dates of every activity and the evaluation criteria.Keywords: Teacher training, blended learning, attitudes, virtual platforms.

El presente artículo tiene como finalidad analizar los comportamientos de las redes sociales, ya que cada vez es más común que la sociedad las utilice para intercambiar, negociar y difundir información por diferentes motivos. Dentro de éste ámbito las redes de investigación, juegan un papel de gran importancia, ya que tiene como prioridad comunicar y divulgar el conocimiento científico, tratando que llegue a una gran cantidad de lectores, para lo cual la red es un elemento imprescindible. Una red de aprendizaje parte del principio que todos vivimos en sociedad y aprendemos con base a interacciones, gracias a las Tecnologías de Información y Comunicación y la conectividad, estas interacciones también se dan en el ciberespacio donde las comunidades negocian significados construidos por el grupo social. Una red de aprendizaje tiene un gran valor, en primer lugar porque en ella todos pueden ser enseñantes o aprendices y seguir comunicando los aprendizajes o informaciones entre otros grupos sociales, lo que hace que las redes tomen mayor poder, ya que un mensaje se potencia con los reenvíos y así la organización tiene la posibilidad de crecer y reconfigurar su extensión y funcionalidad. En este sentido se puede analizar el comportamiento de la red a partir de la Ley de Metcalf, que establece que el valor de una red de comunicación se incrementa en la medida que sus usuarios se incrementan, ya que la relación entre el valor de la red y el número de usuarios es exponencial.

Chicken feathers are composed mainly of avian keratin, a fibrillar protein with a complex structure, and important properties such as durability, hydrophobicity, being chemically unreactive, and depending on the specific function can change its morphological and inner structure. This study takes advantage of these features and for the first time the use of keratin from chicken feathers to modify characteristics on expansive soils is reported. Swelling characteristics of remolded expansive soil specimens were studied through varying the percentage of keratin fiber content using 0.25, 0.50, 1.00 and 3.00 wt%. One-dimensional swell-consolidation tests were conducted on oedometric specimens, specific surface area was determined using methylene blue, and degree of saturation was also analyzed. Finally random distribution and interaction between keratin structures and soil were studied by scanning electron microscopy. The results show that randomly distributed fibers are useful in restraining the swelling tendency of expansive soils. The maximum reduction of pressure (43.99%) due to swelling is achieved by reducing the void ratio, which can be reached with the addition of chicken feather keratin structures to the expansive soil. Finally, the mechanism by which discrete and randomly distributed fibers reduce swelling pressure of expansive soil is explained.

Background Despite the prophylactic use of allopurinol, tumor lysis syndrome (TLS)-related morbidity and mortality still occur in a number of patients with acute myeloid leukemia (AML). The aim of this study was: (i) to analyze the incidence and outcome of TLS in a large series of patients with AML receiving hyperhydration and allopurinol, (ii) to identify risk factors for TLS, and (iii) to develop a prognostic scoring system for estimating individual risk of TLS.Design and Methods The study included 772 adult patients with AML receiving induction chemotherapy between 1980 and 2002. TLS was divided into laboratory TLS (LTLS) or clinical TLS (CTLS). The population study was randomly divided into training and test subsets, so that a prognostic model for CTLS was developed in one set and validated in the other.Results Overall, 130 patients (17%) developed TLS (5% CTLS and 12% LTLS). Unlike LTLS, CTLS was associated with a higher rate of death from induction therapy. Multivariate analysis showed that pretreatment serum lactate dehydrogenase (LDH) levels above laboratory normal values, creatinine >1.4 mg/dL, uric acid >7.5 mg/dL and white blood cell (WBC) counts >25 × 109/L were independent risk factors for CTLS and LTLS. The scoring system, based on pretreatment WBC counts, and uric acid and LDH serum levels, had excellent discrimination and was accurate for predicting CTLS and LTLS.Conclusions TLS is frequently observed in AML patients during induction therapy. Only the development of CTLS had an impact on higher mortality rate from induction therapy. The scoring system derived from this study can be used to obtain an accurate estimate of the individual risk of TLS, allowing for risk-adapted prophylaxis against this complication.

The historical process of the infirmary has had great evolution in Mexico its beginnings, in the professional order, have taken to a great height to the National Institute of Cardiology; in the year of 1944, the Dr. Ignacio Chávez had great vision and assertivity when considering to religious nurses to direct different services to it; they have been and are at the moment an essential piece to continue the evolution of infirmary in the National Institute of Cardiology. It is possible to mention that the historical way of the infirmary must to the effort of the group of nuns who have known to guide and to lead to the team of nurses of the Institute, promoting at any moment the quality of attention provided to the patients with cardiovascular affections.