How Do Y-Chromosomes Modulate Genome-Wide Epigenetic States: Genome Folding, Chromatin Sinks, and Gene Expression

The Y chromosomes of Drosophila melanogaster and D. simulans contain only a handful of protein-coding genes, which are related to sperm mobility and reproductive fitness. Despite low or absent protein coding polymorphism, the Drosophila Y chromosome has been associated with natural phenotypic variation, including variation in the expression of hundreds to thousands of genes located on autosomes and on the X chromosome. Polymorphisms present in the large blocks of heterochromatin and consisting of differences in the amounts and kinds of sequences for satellite DNA and transposable elements may be the source of this modulation. Here we review the evidence and discuss mechanisms for global epigenetic regulation by repetitious elements in the Y chromosome. We also discuss how the discovery of this new function impacts the current knowledge about Y chromosome origin, its current dynamics, and future fate

MULTI-INSTRUMENTAL IDENTIFICATION OF ORPIMENT IN ARCHAEOLOGICAL MORTUARY CONTEXTS

Indexación: Web of Science; Scielo.This paper reports on an unknown yellowish mineral compound found in an archaeological context from Chorrillos cemetery (Calama, Chile) dating to the Early Formative period (800 - 200 B.C.). We used optic microscopy, SEM, EDX, 1H-RMN, 13C-RMN, and infrared (IR) and Raman spectroscopy to tease out the chemical and molecular composition of the sample. The microscopic images show amorphous yellowish granulates with heterogeneous chemical surfaces. 1H-RMN and 13C-RMN negative results show that the sample is free of organic matter. The SEM and EDX indicate the presence of arsenic and sulfur in the sample. The IR and Raman analyses suggest the presence of orpiment which is a toxic yellow arsenic sulfide mineral.http://ref.scielo.org/mfcms

Reference priors for high energy physics

Bayesian inferences in high energy physics often use uniform prior distributions for parameters about which little or no information is available before data are collected. The resulting posterior distributions are therefore sensitive to the choice of parametrization for the problem and may even be improper if this choice is not carefully considered. Here we describe an extensively tested methodology, known as reference analysis, which allows one to construct parametrization-invariant priors that embody the notion of minimal informativeness in a mathematically well-defined sense. We apply this methodology to general cross section measurements and show that it yields sensible results. A recent measurement of the single top quark cross section illustrates the relevant techniques in a realistic situation

Variabilidad intraespecífica del gastrópodo struthiolarido perissodonta ameghinoi (ihering, 1897), mioceno temprano, Tierra del Fuego, Argentina

Los depósitos marinos del Mioceno temprano en Tierra del Fuego albergan un grupo de gasterópodos struthiolaridos que se destacan por su alta variabilidad morfológica. Desde finales del siglo 19 se interpretó que esta variabilidad reflejaba (1) un grupo de especies altamente diversificado en rápida evolución o (2) una única especie plástica caracterizada por una amplia variabilidad intraespecífica. El estudio morfológico de más de 100 ejemplares del género Perissodonta Martens recolectados en las formaciones fueguinas Carmen silva, Viamonte e Irigoyen indica que parámetros significativos, como la forma del caparazón, la longitud de la espira y el número de ornamentaciones espirales y axiales (líneas espirales finas, cordones, tubérculos) varían continuamente dentro de una amplia gama de valores, favoreciendo una única especie plástica. Los especímenes topotipo de Perissodonta ameghinoi (Ihering), recolectados de la Formación Monte León del Mioceno temprano en la Patagonia, muestran una plasticidad de caracteres similar. Además, material de topotipo reciente de Perissodonta georgiana strebel de las Islas Georgias del sur, una especie considerada sinónimo muy cercano o junior del genotipo de la especie P. mirabilis (smith), indica un grado similar de plasticidad. En consecuencia, los struthiolaridos fueguinos asignados previamente a Perissodonta ameghinoi; P. fueguina (Ihering) o P. densestriata (Ihering) se refieren en este trabajo a P. ameghinoi, un gasterópodo struthiolarido restringido al Mioceno temprano en Tierra del Fuego y Patagonia.The early Miocene marine deposits in Tierra del Fuego bear a group of struthiolariid gastropods that stand out for their high morphological variability. since the end of the 19th century this variability was interpreted as reflecting (1) a highly diversified rapidly evolving group of species or (2) a single, plastic species characterized by ample intraspecific variability. The morphological study of more than 100 specimens of the Fuegian struthiolariid genus Perissodonta Martens collected in the Carmen silva, Viamonte, and Irigoyen formations indicate that significant parameters, such as shell shape, spire length and number of spiral and axial sculptures (cords, threads, tubercles) vary continuously within an ample range of values, favoring a single, plastic species. Topotype specimens of Perissodonta ameghinoi (Ihering), collected from the early Miocene Monte León Formation in Patagonia, show similar plasticity of characters. Furthermore, recent topotype material of Perissodonta georgiana strebel from Islas Georgias del sur, a species considered very close or junior synonym of the genotype species P. mirabilis (smith), indicates a similar degree of plasticity. Accordingly, the Fuegian struthiolariids previously assigned to Perissodonta ameghinoi; P. fueguina (Ihering); or P. densestriata (Ihering) are here referred to P. ameghinoi, a struthiolariid gastropod restricted to the early Miocene in Tierra del Fuego and Patagonia.Fil: Lopez Cabrera O., Maria Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Olivero, Eduardo Bernardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego; Argentin

Reporting Model for Decision Support Based on the SAF-T Standard

The purpose of this paper is to summarize the results and conclusions obtained during an investigation aiming to reveal the usefulness and added value of the SAF-T when used to support decision making and the internal management of organizations. The research addresses the SAF-T standard as a source of knowledge for decision support and intelligent auditing. The research contextualizes the contribution of the SAF-T based model as a scalable way to make intelligent audits, implement new business processes and manage electronic control. The information quality of this report and digital model is also stressed. Upon automatic reporting based on SAF-T data one can draw financial conclusions and decide changes on a firm´s commercial scope. This article also highlights the advantages of decision making based on the proposed model and report. A set of hints and suggestions for further re-search work on this topic is also provided