Fragile X syndrome.

Fragile X Syndrome (FXS) is a genetic disease due to a CGG trinucleotide expansion, named full mutation (greater than 200 CGG repeats), in the fragile X mental retardation 1 gene locus Xq27.3; which leads to an hypermethylated region in the gene promoter therefore silencing it and lowering the expression levels of the fragile X mental retardation 1, a protein involved in synaptic plasticity and maturation. Individuals with FXS present with intellectual disability, autism, hyperactivity, long face, large or prominent ears and macroorchidism at puberty and thereafter. Most of the young children with FXS will present with language delay, sensory hyper arousal and anxiety. Girls are less affected than boys, only 25% have intellectual disability. Given the genomic features of the syndrome, there are patients with a number of triplet repeats between 55 and 200, known as premutation carriers. Most carriers have a normal IQ but some have developmental problems. The diagnosis of FXS has evolved from karyotype with special culture medium, to molecular techniques that are more sensitive and specific including PCR and Southern Blot. During the last decade, the advances in the knowledge of FXS, has led to the development of investigations on pharmaceutical management or targeted treatments for FXS. Minocycline and sertraline have shown efficacy in children

Perspectivas teóricas de aproximación a la organización y estructura de la institución educativa.

109 Páginas.Se propone un marco analítico que caracteriza y distingue las diferentes aproximaciones o perspectivas teóricas que se han planteado para estudiar la organización y estructura de las instituciones educativas, así como los enfoques al interior de cada perspectiva. En la perspectiva de la sociología de la organización escolar, se visualiza la institución educativa como organización, en la cual se identifican tres enfoques: organización formal, articulación de modo impreciso y orden interactivo. La finalidad de esta perspectiva es descriptiva y utiliza principalmente modo inductivos, generativos, constructivos y objetivos. En la perspectiva de la administración educativa, se estudia la organización de la institución educativa, en la cual se plantearon tres enfoques: empresa educativa, organización humana bajo el enfoque antropológico y calidad escolar. Por su parte, esta perspectiva, se orienta hacia la prescripción, mediante la deducción, verificación, enumeración y objetividad

Forms of Participatory Democracy: An Analytical Framework Based on the Experiences of Bolivia, Brazil and Colombia

Based on the experiences of Colombia, Brazil and Bolivia, the paper proposes a general analytical framework for participatory mechanisms. The analysis is oriented to detect the incentives in each system and the ethics and behavior sustaining them. It investigates about the sustainability of participatory democracy, in the face of tensions with representative democracy. The article presents a theoretical framework built from these experiences of institutional design and political practice, and confronts it against the theoretical conceptualizations of participatory democracy in Bobbio, Sartori, Elster and Nino, among others. In this context, different ways in wich those schemes can be inserted in the political systems become apparent, along with the variables that result from combinig elements of direct, representative and participatory democracy.********************************************************************************************************A partir de la experienca de Colombia, Brasil y Bolivia, el artículo propone un marco de análisis general de esquemas de democracia participativa. El análisis está orientado a detectar los incentivos presentes en cada uno de los sistemas y la ética y el comportamiento que sostiene estas instituciones. Investiga además su sostenibilidad al enfrentar tensiones en su interacción con la democracia representativa. El artículo presenta un marco teórico a partir de estas experiencias de diseño institucional y prácticas políticas, y su comparación con las conceptualizaciones teóricas de la democracia participativa de Bobbio, Sartori, Elster y Nino, entre otros. En este análisis se resaltan las diferentes maneras en que tales sistemas políticos son introducidos, así como las variables que resultan de la combinación entre democraica directa, participativa y representativa.democracy, participation, participatory budgets, local government

Cosmic web alignments with the shape, angular momentum and peculiar velocities of dark matter haloes

We study the alignment of dark matter haloes with the cosmic web characterized by the tidal and velocity shear fields. We focus on the alignment of their shape, angular momentum and peculiar velocities. We use a cosmological N-body simulation that allows to study dark matter halos spanning almost five orders of magnitude in mass ($10^{9}$-$10^{14}$) $h^{-1}$$M_{\odot}$ and spatial scales of $(0.5$-$1.0)$ $h^{-1}$ Mpc to define the cosmic web. We find that the halo shape presents the strongest alignment along the smallest tidal eigenvector, e.g. along filaments and walls, with a signal that gets stronger as the halo mass increases. In the case of the velocity shear field only massive halos $>10^{12}$ $h^{-1}$$M_{\odot}$ tend to have their shapes aligned along the largest tidal eigenvector; that is, perpendicular to filaments and walls. For the angular momentum we find alignment signals only for halos more massive than $10^{12}$ $h^{-1}$$M_{\odot}$ both in the tidal and velocity shear webs where the preferences are for it to be parallel to the middle eigenvector; perpendicular to filaments and parallel to walls. Finally, the peculiar velocities show a strong alignment along the smallest tidal eigenvector for all halo masses; halos move along filaments and walls. In the velocity shear the same alignment is present but weaker and only for haloes less massive than $10^{12}$ $h^{-1}$$M_{\odot}$. Our results clearly show that the two different algorithms we used to define the cosmic web describe different physical aspects of non-linear collapse and should be used in a complementary way to understand the effect of the cosmic web on galaxy evolution.Comment: 14 pages, 5 figures, MNRAS accepte

Impact of Cosmic Variance on the Galaxy-Halo Connection for Lyman-α\alpha Emitters

In this paper we study the impact of cosmic variance and observational uncertainties in constraining the mass and occupation fraction, $f_{\rm occ}$, of dark matter halos hosting Ly-$\alpha$ Emitting Galaxies (LAEs) at high redshift. To this end, we construct mock catalogs from an N-body simulation to match the typical size of observed fields at $z=3.1$ ($\sim 1 {\rm deg^2}$). In our model a dark matter halo with mass in the range $M_{\rm min}<M_{\mathrm h}<M_{\rm max}$ can only host one detectable LAE at most. We proceed to explore the parameter space determined by $M_{\rm min}$,$M_{\rm max}$ and $f_{\rm occ}$ with a Markov Chain Monte-Carlo algorithm using the angular correlation function (ACF) and the LAEs number density as observational constraints. We find that the preferred minimum and maximum masses in our model span a wide range $10^{10.0}h^{-1}{\rm{M_{\odot}}}\leq M_{\rm min} \leq 10^{11.1}h^{-1}{\rm{M_{\odot}}}$ , $10^{11.0}h^{-1}{\rm{M_{\odot}}}\leq M_{\rm max} \leq 10^{13.0}h^{-1}{\rm{M_{\odot}}}$; followed by a wide range in the occupation fraction $0.02\leq f_{\rm occ} \leq 0.30$. As a consequence the median mass, $M_{50}$, of all the consistent models has a large uncertainty $M_{50} = 3.16^{+9.34}_{-2.37}\times 10^{10}$$h^{-1}{\rm{M_{\odot}}}$. However, we find that the same individual models have a relatively tight $1\sigma$ scatter around the median mass $\Delta M_{1\sigma} = 0.55^{+0.11}_{-0.31}$ dex. We are also able to show that \focc\ is uniquely determined by $M_{\rm min}$, regardless of $M_{\rm max}$. We argue that upcoming large surveys covering at least $25$ deg$^{2}$ should be able to put tighter constraints on $M_{\rm min}$ and $f_{\rm occ}$ through the LAE number density distribution width constructed over several fields of $\sim 1$ deg$^{2}$.Comment: 7 Pages, 5 figures. Accepted for publication in Ap

Cibersocioantropología de comunidades virtuales

El texto describe, desde perspectivas sociológicas y antropológicas, las principales formas de investigar las interacciones sociales mediadas por el uso de las Tecnologías de la Información y la Comunicación (TIC) en el contexto de la llamada Sociedad de la Información (SI), particularmente aquellas que ocurren en el ciberespacio. Se exponen elaboraciones teóricas y conceptuales a partir de la emergencia de estas nuevas relaciones sociales, y se abordan el método y las técnicas que la etnografía virtual utiliza para el conocimiento de los fenómenos sociales que ocurren en el ciberespacio