La sombra del patriarcado en las redes sociales del aula

La sociedad actual se encuentra inmersa en profundos cambios relacionales ligados a la identidad de género, manifestándose de diferentes formas, entre las que se encuentra la violencia de género. En este sentido, y en el marco del proyecto de excelencia Teón XXI, en el que se está realizando el diagnóstico de género en el sistema escolar andaluz como primera medida para la prevención de conductas violentas, cobra importancia analizar las relaciones que los y las estudiantes establecen. Así, el análisis de las redes sociales del aula constituye el objetivo principal de este estudio. En este trabajo se desarrollan técnicas sociométricas para analizar las redes sociales del aula con perspectiva de género, los posicionamientos y el estatus del alumnado. La metodología experimental utilizada, complementada con encuesta y observación, permite valorar la incidencia de los mandatos del patriarcado en la sociología escolar en aulas de Educación Primaria y Secundaria de Sevilla. Los resultados muestran cómo los mandatos de género influyen en la elección y rechazo de estudiantes, asimismo se contrastan diferencias en las relaciones que establece el alumnado según el supuesto presentado, identificándose formas de liderazgo diferentes en función del género

Discourses of boys about masculinity in school settings. A pilot study

Este trabajo se basa parcialmente en el trabajo fin de master en género realizado por Rita Santana bajo la dirección de Mª Ángeles Rebollo en el marco de este proyecto.Este estudio piloto presenta y describe los discursos de niños varones en contextos escolares con el objetivo de analizar el papel que desempeñan el sexismo y la homofobia en la construcción de la masculinidad. La metodología empleada fue la del microanálisis etnográfico. Para ello empleamos las técnicas de la observación participante para analizar las interacciones que se dan en los centros escolares elegidos e entrevistas semi-estructuradas para analizar el discurso de 12 niños varones de 10 a 12 años de tres centros de Educación Primaria de Sevilla. El análisis de los discursos se ha centrado en los significados y emociones que los niños asocian a ciertas prácticas. El análisis de los discursos muestra cómo el control social ejercido entre iguales modela las interpretaciones y valoraciones de las prácticas asociadas a la masculinidad. Nuestro trabajo ejemplifica cómo de forma temprana el proceso de generización entre los hombres se construye desligándose de los modelos de femineidad desde la infancia. De ahí que el sexismo y la homofobia funcionen como ejes activos en la formulación normativa sobre “ser hombre”, por eso recomendamos la implementación de programas coeducativos a partir de la educación primaria.This pilot study presents and describes the discourses of boys in school settings in order to analyze the role of sexism and homophobia in the construction of masculinity. The methodology used was ethnographic microanalysis. For this we use the techniques of participant observation to analyze the interactions that occur in selected schools and semi-structured interviews to analyze the speech of 12 boys aged 10 to 12 years from three Primary Schools in Seville. The discourse analysis has focused on the meanings and emotions that children associate to certain practices. The discourse analysis shows how social control exercised by fellow, model interpretations and evaluations of the practices associated with masculinity. Our work shows how early sexism and homophobia are active axes in formulating rules about "being a man", so we recommend the implementation of coeducational programs from primary education.Grupo FORCE (HUM-386). Departamento de Didáctica y Organización Escolar de la Universidad de Granada.Este trabajo ha sido posible gracias al proyecto de investigación de excelencia “Teón XXI: Creación de recursos digitales para el conocimiento y difusión de la cultura de género en la escuela” (P06-HUM-01408), financiado por la Consejería de Innovación, Ciencia y Empresa de la Junta de Andalucía. BOJA nº 71 de 11 de abril de 2007 (ref. P06-HUM-01408)

Statistical-Analysis of a Mixed-Layer X-Ray-Diffraction Peak

Fil: Rebollo-Neira, Laura. Department of Mathematics. Aston University. Birmingham; United KingdomFil: Constantinides, Anthony G.. Imperial College London. Department of Electrical and Electronic Engineering. London; United KingdomFil: Plastino, Ángel Luis. CONICET; ArgentinaFil: Alvarez, Alberto Guillermo. Departamento de Química. Universidad de Los Andes; ColombiaFil: Bonetto, Rita D.. Centro de Investigación y Desarrollo en Ciencias Aplicadas Dr. Jorge J. Ronco. CINDECA. Facultad de Ingeniería y de Ciencias Exactas. Universidad Nacional de La Plata; ArgentinaFil: Iñíguez Rodríguez, Adrián Mario. Centro de Investigaciones Geológicas (CIG). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

Inter-Strain Epigenomic Profiling Reveals a Candidate IAP Master Copy in C3H Mice.

Insertions of endogenous retroviruses cause a significant fraction of mutations in inbred mice but not all strains are equally susceptible. Notably, most new Intracisternal A particle (IAP) ERV mutagenic insertions have occurred in C3H mice. We show here that strain-specific insertional polymorphic IAPs accumulate faster in C3H/HeJ mice, relative to other sequenced strains, and that IAP transcript levels are higher in C3H/HeJ embryonic stem (ES) cells compared to other ES cells. To investigate the mechanism for high IAP activity in C3H mice, we identified 61 IAP copies in C3H/HeJ ES cells enriched with H3K4me3 (a mark of active promoters) and, among those tested, all are unmethylated in C3H/HeJ ES cells. Notably, 13 of the 61 are specific to C3H/HeJ and are members of the non-autonomous 1Δ1 IAP subfamily that is responsible for nearly all new insertions in C3H. One copy is full length with intact open reading frames and hence potentially capable of providing proteins i

Statistical analysis of a mixed-layer x-ray diffraction peak

A mathematical model to describe the line shape of an x-ray diffraction peak from stacks of different layers such as, for instance, an interstratified clay mineral has been evolved. The aim was to be able to analyse the proportions of different specific stacking sequences in two-component interstratified samples. A maximum-entropy algorithm was applied to observed powder-diffraction intensities in order to obtain the probability of each stacking sequence. Application to natural smectite-illite clays gave reasonable results.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Ciencias AplicadasCentro de Investigaciones Geológica

Transcriptomic-based selection of reference genes for quantitative real-time PCR in an insect endosymbiotic model

Reference genes are a fundamental tool for analyses of gene expression by real-time quantitative PCR (qRT-PCR), in that they ensure the correct comparison between conditions, stages, or treatments. Because of this, selection of appropriate genes to use as references is crucial for proper application of the technique. Nevertheless, efforts to find appropriate, stably expressed transcripts are still lacking, in particular in the field of insect science. Here, we took advantage of a massive transcriptomic high-throughput analysis of various developmental stages of the gut and associated-bacteriomes of the cereal weevil Sitophilus oryzae and identified a subset of stably expressed genes with the potential to be used as housekeeping genes from the larva to the adult stage. We employed several normalization techniques to select the most suitable genes among our subset. Our final selection includes two genes–TAO, and YTH3–which can also be used to compare transcript abundance at various developmental stages in symbiotic insects, and in insects devoid of endosymbionts (aposymbiotic). Since they are well conserved, these genes have the potential to be useful for many other insect species. This work confirms the interest in using large-scale, unbiased methods for reference gene selection

Retrotransposon-Induced Heterochromatin Spreading in the Mouse Revealed by Insertional Polymorphisms

The “arms race” relationship between transposable elements (TEs) and their host has promoted a series of epigenetic silencing mechanisms directed against TEs. Retrotransposons, a class of TEs, are often located in repressed regions and are thought to induce heterochromatin formation and spreading. However, direct evidence for TE–induced local heterochromatin in mammals is surprisingly scarce. To examine this phenomenon, we chose two mouse embryonic stem (ES) cell lines that possess insertionally polymorphic retrotransposons (IAP, ETn/MusD, and LINE elements) at specific loci in one cell line but not the other. Employing ChIP-seq data for these cell lines, we show that IAP elements robustly induce H3K9me3 and H4K20me3 marks in flanking genomic DNA. In contrast, such heterochromatin is not induced by LINE copies and only by a minority of polymorphic ETn/MusD copies. DNA methylation is independent of the presence of IAP copies, since it is present in flanking regions of both full and empty sites. Finally, such spreading into genes appears to be rare, since the transcriptional start sites of very few genes are less than one Kb from an IAP. However, the B3galtl gene is subject to transcriptional silencing via IAP-induced heterochromatin. Hence, although rare, IAP-induced local heterochromatin spreading into nearby genes may influence expression and, in turn, host fitness

Publisher Correction: Chemotherapy-induced transposable elements activate MDA5 to enhance haematopoietic regeneration.

Funder: RCUK | Medical Research Council (MRC); doi: https://doi.org/10.13039/501100000265Funder: Max-Planck-Gesellschaft (Max Planck Society); doi: https://doi.org/10.13039/50110000418

Chemotherapy-induced transposable elements activate MDA5 to enhance haematopoietic regeneration.

Funder: RCUK | Medical Research Council (MRC); doi: https://doi.org/10.13039/501100000265Funder: Max-Planck-Gesellschaft (Max Planck Society); doi: https://doi.org/10.13039/501100004189Haematopoietic stem cells (HSCs) are normally quiescent, but have evolved mechanisms to respond to stress. Here, we evaluate haematopoietic regeneration induced by chemotherapy. We detect robust chromatin reorganization followed by increased transcription of transposable elements (TEs) during early recovery. TE transcripts bind to and activate the innate immune receptor melanoma differentiation-associated protein 5 (MDA5) that generates an inflammatory response that is necessary for HSCs to exit quiescence. HSCs that lack MDA5 exhibit an impaired inflammatory response after chemotherapy and retain their quiescence, with consequent better long-term repopulation capacity. We show that the overexpression of ERV and LINE superfamily TE copies in wild-type HSCs, but not in Mda5-/- HSCs, results in their cycling. By contrast, after knockdown of LINE1 family copies, HSCs retain their quiescence. Our results show that TE transcripts act as ligands that activate MDA5 during haematopoietic regeneration, thereby enabling HSCs to mount an inflammatory response necessary for their exit from quiescence

Variation des éléments transposables dans les populations naturelles de drosophila : nombre de copies, transcription et état de la chromatine

Transposable elements (TEs) are one major force of genome evolution thanks to theirability to create genetic variation. TEs are ubiquitous and their proportion is variable between species and also populations, suggesting that a tight relationship exists between genomes and TEs. The model system composed of the natural populations of the twin sisters Drosophila melanogaster and D. simulans is interesting to compare host/TE relationship, since both species harbour different amounts of TE copies. The helena element is nearly silenced in D.simulans natural populations despite a very high copy number. Such repression is associated to abundant internally deleted copies suggesting a regulatory mechanism of TEs based on DNA deletion. Another pathway of TE regulation is through epigenetics where the host genome is able to keep intact the DNA sequences of TEs and still silence their activities.Chromatin remodelling is well known in drosophila and specific histone modifications can be associated to specific chromatin domains. We observed an important variation on H3K27me3and H3K9me2, two heterochromatic marks, on TE copies in D. melanogaster and D. simulans natural populations. Also, we show that derepressed lines of D. simulans exist for specific elements, have high TE transcription rates and are highly associated to non constitutive heterochromatic marks. TEs are therefore controlled by the host genome through DNA deletion and a possible chromatin remodelling mechanism. Not only genetic variability is enhanced by TEs but also epigenetic variability, allowing the host genome to be partitioned into chromatin domains. TEs are therefore mandatory to gene network regulation through their ability of “jumping epigenetics”.Les éléments transposables (ET) sont une source majeure de variation génétique, ce qui leur confère un rôle essentiel dans l’évolution des génomes. Certes présents dans tous les génomes analysés à ce jour, leurs proportions sont fortement variables entre espèces et aussi entre populations, suggérant une relation unique entre génome hôte et ET. Grâce à un système modèle composé de populations naturelles de deux espèces proches (Drosophila melanogaster et D. simulans) avec des quantités différentes en ET, nous avons pu comparer les relations génome hôte/ET. Nous nous sommes particulièrement interessés à l’élément helena qui, chez D. simulans, montre une activité faible, malgré un nombre de copies élevé.Cette activité moindre est associée à de nombreuses délétions internes des copies, suggérant un mécanisme de régulation d’ET par des délétions de l’ADN. Un autre système de régulation de l’activité des ET utilise le contrôle épigénétique, ce qui permet le maintien des copies d’ET dans le génome mais un blocage de leur activité. Le remodelage de la chromatine est un système épigénétique bien décrit chez la drosophile. Les régions chromatiniennes des génomes sont associées à différents types de modifications d’histone. Nous avons mis en évidence, dans des populations de D. melanogaster et D. simulans, une variation conséquente de modifications d’histones de type hétérochromatique, H3K27me3 et H3K9me2, associées àdes copies de différents ET. De plus, nous avons décrit des populations chez D. simulans dites déréprimées, chez lesquelles certains éléments sont surexprimés et présentent des localisations probablement hétéchromatiques. Les ET sont donc contrôlés par le génome hôte par des délétions internes et probablement par un système épigénétique variable. De plus, dans certaines populations, des copies peuvent échapper à ce contrôle et envahir le génome. Les ET sont donc des grands créateurs de variabilité génétique mais permettent aussi une territorialisation chromatinienne du génome car ils portent des modifications épigénétiques précises et sont capables de les étendre à leurs environnements génomiques. Ceci leur confére la fonction "d'épigénétique mobile"