Relaciones entre los aspectos cognitivos y emocionales de la enseñanza

Desde que Shulman (1986) propuso el concepto de conocimiento didáctico de contenido (CDC) se han realizado una gran cantidad de investigaciones al respecto; algunas referentes a las ideas o conceptos que se deben incluir en el CDC, otras referentes a las relaciones con la materia y otras sobre cómo el profesor desarrolla su CDC. Sin embargo, a pesar de que muchos autores han señalado la importancia de las emociones en la enseñanza, poco o nada se ha hecho para estudiar si el CDC tiene un lado emocional. En este trabajo se estudian las relaciones entre ambos aspectos de la enseñanza universitaria en química; para ello se parte del modelo de CDC propuesto por Magnusson et al. (1999) y se proponen tres nuevos componentes relacionados con las emociones del docente hacia la materia, los estudiantes y hacia su propia enseñanza

Intra-sexual competition alters the relationship between testosterone and ornament expression in a wild territorial bird

Open Access funded by Natural Environment Research Council Under a Creative Commons licensePeer reviewedPublisher PD

N,N′-Bis(4-amino­benz­yl)oxalamide

In the title compound, C16H18N4O2, the two carbonyl groups are in an anti­periplanar conformation with an O=C—C=O torsion angle of 173.86 (17)°. In the crystal, a pair of inter­molecular N—H⋯O hydrogen bonds, forming an R 2 2(10) ring motif, connect the mol­ecules into an inversion dimer. The dimers are further linked by N—H⋯N and C—H⋯π inter­actions, forming a zigzag chain along the b axis

Experience of parents who have suffered a perinatal death in two Spanish hospitals: a qualitative study

Background: Perinatal grief is a process that affects families in biological, psychological, social and spiritual terms. It is estimated that every year there are 2.7 million perinatal deaths worldwide and 4.43 deaths for every 1000 births in Spain. The aim of this study is to describe and understand the experiences and perceptions of parents who have suffered a perinatal death. Methods: A qualitative study based on Gadamer’s hermeneutic phenomenology. The study was conducted in two hospitals in the South of Spain. Thirteen mothers and eight fathers who had suffered a perinatal death in the 5 years prior to the study participated in this study. In-depth interviews were carried out for data collection. Inductive analysis was used to find themes based on the data. Results: Eight sub-themes emerged, and they were grouped into three main themes: ‘Perceiving the threat and anticipating the baby’s death: “Something is going wrong in my pregnancy”’; ‘Emotional outpouring: the shock of losing a baby and the pain of giving birth to a stillborn baby’; “We have had a baby”: The need to give an identity to the baby and legitimise grief’. Conclusion: The grief suffered after a perinatal death begins with the anticipation of the death, which relates to the mother’s medical history, symptoms and premonitions. The confirmation of the death leads to emotional shock, characterised by pain and suffering. The chance to take part in mourning rituals and give the baby the identity of a deceased baby may help in the grieving and bereavement process. Having empathy for the parents and notifying them of the death straightaway can help ease the pain. Midwives can help in the grieving process by facilitating the farewell rituals, accompanying the family, helping in honouring the memory of the baby, and supporting parents in giving the deceased infant an identity that makes them a family member

Calibration of semi-analytic models of galaxy formation using Particle Swarm Optimization

We present a fast and accurate method to select an optimal set of parameters in semi-analytic models of galaxy formation and evolution (SAMs). Our approach compares the results of a model against a set of observables applying a stochastic technique called Particle Swarm Optimization (PSO), a self-learning algorithm for localizing regions of maximum likelihood in multidimensional spaces that outperforms traditional sampling methods in terms of computational cost. We apply the PSO technique to the SAG semi-analytic model combined with merger trees extracted from a standard $\Lambda$CDM N-body simulation. The calibration is performed using a combination of observed galaxy properties as constraints, including the local stellar mass function and the black hole to bulge mass relation. We test the ability of the PSO algorithm to find the best set of free parameters of the model by comparing the results with those obtained using a MCMC exploration. Both methods find the same maximum likelihood region, however the PSO method requires one order of magnitude less evaluations. This new approach allows a fast estimation of the best-fitting parameter set in multidimensional spaces, providing a practical tool to test the consequences of including other astrophysical processes in SAMs.Comment: 11 pages, 4 figures, 1 table. Accepted for publication in ApJ. Comments are welcom

The evolution of Balmer jump selected galaxies in the ALHAMBRA survey

We present a new color-selection technique, based on the Bruzual & Charlot models convolved with the bands of the ALHAMBRA survey, and the redshifted position of the Balmer jump to select star-forming galaxies in the redshift range 0.5 < z < 1.5. These galaxies are dubbed Balmer jump Galaxies BJGs. We apply the iSEDfit Bayesian approach to fit each detailed SED and determine star-formation rate (SFR), stellar mass, age and absolute magnitudes. The mass of the haloes where these samples reside are found via a clustering analysis. Five volume-limited BJG sub-samples with different mean redshifts are found to reside in haloes of median masses $\sim 10^{12.5 \pm 0.2} M_\odot$ slightly increasing toward z=0.5. This increment is similar to numerical simulations results which suggests that we are tracing the evolution of an evolving population of haloes as they grow to reach a mass of $\sim 10^{12.7 \pm 0.1} M_\odot$ at z=0.5. The likely progenitors of our samples at z$\sim$3 are Lyman Break Galaxies, which at z$\sim$2 would evolve into star-forming BzK galaxies, and their descendants in the local Universe are elliptical galaxies.Hence, this allows us to follow the putative evolution of the SFR, stellar mass and age of these galaxies. From z$\sim$1.0 to z$\sim$0.5, the stellar mass of the volume limited BJG samples nearly does not change with redshift, suggesting that major mergers play a minor role on the evolution of these galaxies. The SFR evolution accounts for the small variations of stellar mass, suggesting that star formation and possible minor mergers are the main channels of mass assembly.Comment: 14 pages, 10 figures. Submitted to A&A. It includes first referee's comments. Abstract abridged due to arXiv requirement

Gene organization and sequence analyses of transfer RNA genes in Trypanosomatid parasites

<p>Abstract</p> <p>Background</p> <p>The protozoan pathogens <it>Leishmania major</it>, <it>Trypanosoma brucei </it>and <it>Trypanosoma cruzi </it>(the Tritryps) are parasites that produce devastating human diseases. These organisms show very unusual mechanisms of gene expression, such as polycistronic transcription. We are interested in the study of tRNA genes, which are transcribed by RNA polymerase III (Pol III). To analyze the sequences and genomic organization of tRNA genes and other Pol III-transcribed genes, we have performed an <it>in silico </it>analysis of the Tritryps genome sequences.</p> <p>Results</p> <p>Our analysis indicated the presence of 83, 66 and 120 genes in <it>L. major, T. brucei </it>and <it>T. cruzi</it>, respectively. These numbers include several previously unannotated selenocysteine (Sec) tRNA genes. Most tRNA genes are organized into clusters of 2 to 10 genes that may contain other Pol III-transcribed genes. The distribution of genes in the <it>L. major </it>genome does not seem to be totally random, like in most organisms. While the majority of the tRNA clusters do not show synteny (conservation of gene order) between the Tritryps, a cluster of 13 Pol III genes that is highly syntenic was identified. We have determined consensus sequences for the putative promoter regions (Boxes A and B) of the Tritryps tRNA genes, and specific changes were found in tRNA-Sec genes. Analysis of transcription termination signals of the tRNAs (clusters of Ts) showed differences between <it>T. cruzi </it>and the other two species. We have also identified several tRNA isodecoder genes (having the same anticodon, but different sequences elsewhere in the tRNA body) in the Tritryps.</p> <p>Conclusion</p> <p>A low number of tRNA genes is present in Tritryps. The overall weak synteny that they show indicates a reduced importance of genome location of Pol III genes compared to protein-coding genes. The fact that some of the differences between isodecoder genes occur in the internal promoter elements suggests that differential control of the expression of some isoacceptor tRNA genes in Tritryps is possible. The special characteristics found in Boxes A and B from tRNA-Sec genes from Tritryps indicate that the mechanisms that regulate their transcription might be different from those of other tRNA genes.</p

Glomerulonefritis primarias en niños que asisten a un Centro de Referencia en la Región Caribe colombiana

Introduction: Primary glomerulonephritis are diseases that affect the structure and function of the glomerulus. For proliferative glomerulopathies, it has been observed that for IgA and IgM mesangial GN, they are the ones that mostly evolve to end-stage renal failure, followed by membranous-proliferative or mesangiocapillar GN. The clinical manifestation of GN is the result of the combination of hematuria, proteinuria and the presence of acute or chronic renal failure.Material and methods: Medical records were reviewed. They were collected in a database of all biopsies performed from 2008 to 2014. An ?² was used to establish associations between variables (? = 95%). For the differences among proportions Student’s t or U-Mann-Whitney were used.Results: 146 (88%) patients who had complete data were selected. The mean age was 8 ± 4 years old for both sexes. No significant difference was found between gender by age (p? 0.05), nor was there an association between gender and age (p? 0.05). The predominant NGs with the highest prevalence were Proliferative Mesangial and IgA Nephropathy. NGs by Thin Basal Membrane, Nephropathy by C3 and Cq were not present in male patients. The most prevalent syndromic picture was the Nephrotic Syndrome (58%).Conclusions: The existence of this registry of renal biopsies is the basis for the creation of the Registry of Glomerulopathies in children in Colombia, whose data are necessary to establish programs for the treatment and prevention of glomerular diseases in our country in order to decrease its progression.Introducción:Las glomerulonefritis (GN) primarias son enfermedades que afectan a la estructura y función del glomérulo. Dentro de las glomerulopatías proliferativas se ha observado que la GN mesangial por IgA e IgM, son las que evolucionan con mayor frecuencia a la insuficiencia renal permanente; seguida de la GN membrano-proliferativa o mesangiocapilar. La presentación clínica de la GN incluye hematuria, proteinuria e insuficiencia renal aguda o crónica.Material y métodos: Se revisaron las historias clínicas y se acopiaron en una base de datos todas las biopsias realizadas entre los años 2008 a 2014. Se realizó un ?², para establecer las asociaciones entre variables (? = 95%) y para las diferencias entre proporciones se utilizó t de Studentó U- Mann-Whitney.Resultados: Se seleccionaron 146 pacientes (88% del total analizado) que tenían los datos completos. La edad promedio fue de 8±4 años para ambos sexos. No se encontraron diferencias significativasni asociaciones entre el sexo y la edad (p? 0,05). Las GN predominantes fueron las proliferativa mesangial y la nefropatía por IgA. Las GN por membrana basal delgada, nefropatía por C3 y C4 q no se presentaron en varones. La presentación clínica más frecuente fue el Síndrome Nefrótico (58%).Conclusiones: Los hallazgos de éste registro de biopsias renales podrían ser la base para la creación de un Registro de Glomerulopatías en niños en Colombia, instrumento necesario para establecer programas de tratamiento y prevención de las enfermedades glomerulares en nuestro país a fin de disminuir su progresión

Design and construction of a hybrid system of heating air by combustion of biomass and solar radiation, using phase change material (PCM) as a source of thermal storage, for cassava drying

Este estudio consistió en el diseño, la construcción y la validación de un sistema híbrido de calentamiento de aire por combustión de biomasa y radiación solar, utilizando material de cambio de fase (PCM) como fuente de almacenamiento térmico, para el secado de yuca, a pequeña escala. El sistema híbrido consta de un ventilador centrífugo, dos colectores solares, un quemador de combustible sólido (cascarilla de arroz) y un secador de bandejas. La validación del sistema se realizó secando yuca. El PCM permitió seguir el proceso de secado, incluso cuando la radiación solar estuvo por debajo de 116,22 ± 31,94 W/m2, logrando mantener temperaturas de aire de secado en los dos colectores solares a 46 ±4 ,29°C y 51± 4,08°C durante 45 min adicionales. El tiempo de secado fue de 10 h y 45 min, la eficiencia de los colectores solares fue 43,91% y la del quemador de cascarilla de arroz de 36,72%.This study consisted of designing, building and validation a hybrid system of heating air by combustion of biomass and solar radiation, using phase change material (PCM) as a thermal storage source, for cassava drying, a small scale. The dryer consists of a centrifugal fan, two solar collectors, a fuel burner solid (rice husk) and a tray dryer. System validation was performed drying up Yucca. The PCM allowed to follow the drying process, even when the solar radiation was below 116,22 ± 31,94 W / m2, being able to maintain drying air temperatures in the two solar collectors at 46 ± 4, 29 ° C and 51 ± 4.08 ° C for an additional 45 min. The drying time was 10 h and 45 min, the efficiency of the solar collectors was 43.91 % and the rice husk burner of 36.72 %