Métodos para evaluar interacciones entre cuerpos de agua en un humedal y aplicación en dos casos de estudio

La comprensión de la dinámica de ecosistemas dependientes del recurso hídrico subterráneo, como pueden llegar a serlo algunos humedales, parte del conocimiento del sistema hidrológico. Para alcanzar esta meta se aplica una serie de métodos y procedimientos de análisis que comprenden la caracterización hi-drogeológica, la delimitación del área de captura de agua hacia el humedal, el monitoreo piezométrico, la rea-lización de balances de masas. La modelación numérica, los análisis hidrogeoquímicos y los métodos isotópi-cos permiten refinar y validar los modelos conceptuales. En el marco del proyecto Hydrochemical and isotopic techniques for assessment hidrological proccesses on wetlands, promovido entre los años 2006 y 2011 por la Agencia Internacional de Energía Atómica (IAEA), Colombia y Argentina compartieron conoci-miento y experiencias para entender la dinámica de los humedales Ciénaga Colombia y La Salada. En este texto se resumen aspectos metodológicos y los resultados de los dos casos de estudio considerados.The Understanding of ecosystem dynamics, for example the wetlands, depends of the knowledge of the hydrologic system. Many techniques can be used in order to obtain a good conceptual mod-el of the wetlands and its catchment area: hydrogeology, numerical modeling, hydrogeochemestry, and iso-tope hydrology. researchers of Argentina and Colombia studied -According with the project: ―Hydrochemical and isotopic techniques for assessment hidrological proccesses on wetlands‖ (IAEA, 2006 to 2011)- two wet-lands hydrogeology dependent: La salada Pond and Cienaga Colombia Weltand. These projects used method-ologies similar and they obtained validated hydrological models

Caracterización preliminar de las interacciones aguas subterráneas-humedales-ser humano en Iberoamérica y en la Península Ibérica

El proyecto UNESCO IGCP 604 tiene como objetivo elaborar un marco conceptual sobre las interacciones aguas subterráneas–humedales-ser humano, y está motivado por el Programa de Evaluación de los Ecosistemas del Milenio de Naciones Unidas. Como resultados preliminares se ha elaborado información de catorce humedales en nueve países. Sus características morfológicas, hidrológicas, químicas, etc. son muy variables. Solamente los servicios de abastecimiento de agua y de regulación hídrica parecen estar ampliamente extendidos, con una tendencia dominante a mantenerse estables o a empeorar. Todos los servicios culturales son frecuentes y muestran una tendencia mayoritaria a mejorar. Entre los factores que inducen cambios en los servicios, los de impacto más extendido son: extracción de agua, cambios en el uso de suelo, contaminación y cambio climático y global. Presentan impactos variables, pero la tendencia general es a mantenerse estables o a aumentar.This paper presents the preliminary results of The UNESCO project IGCP 604, whose objec-tive is to elaborate a conceptual framework on groundwater-wetland-human beings interactions, and is moti-vated by the UNESCO Millennium Ecosystems Assessment Programme. Data from fourteen wetlands in nine countries have been elaborated. Their morphological, hydrological, chemical, etc. characteristics are highly variable. Only the water supply and water regulation services seem to be widely extended, and their general evolution trend is to be stable or to worsen. All the cultural services seem to be widely extended, and the dominant trend is to improve. The factors that most widely induce changes in wetland services are water ex-traction, biological exploitation, changes in land use, pollution, and climate and global change. They cause variable impacts, which tend to be stable or to increase

Estudio seroepidemiológico del virus respiratorio sincitial bovino en el municipio de Montería, Colombia

RESUMEN Objetivo. El propósito de esta investigación fue realizar un estudio seroepidemiológicopara detectar anticuerpos específicos contra el Virus Respiratorio Sincitial Bovino (BRSV)mediante la técnica comercial de ELISA (Bio-X ® BRSV Elisa Kit, Bruselas, Bélgica), con elfin de demostrar de manera indirecta, la presencia y circulación del VRSB en el municipio deMontería, Colombia. Materiales y métodos. Se recolectaron 163 muestras de sangre (137de hembras y 26 de toros) de animales con antecedentes de infertilidad, pertenecientes a28 fincas, los cuales provenían de 4 diferentes zonas equidistantes dentro del municipio.Todas las muestras fueron seleccionadas al azar. Se realizó un análisis descriptivo con losdatos serológicos obtenidos de cada animal e interpretándolos con las variables: raza,edad, zona, tipo de explotación, sexo y alteraciones reproductivas. Para determinar laasociación entre seropositividad y cada una de las variables se utilizó la prueba de c2. Nohubo diferencias significativas para ninguna de las variables analizadas. Resultados. Sedetectaron anticuerpos en 22 de los animales seleccionados, lo que correspondió al 13%del total muestreado. Conclusiones. Este hallazgo constituye la demostración indirecta dela presencia del VRSB en el municipio de Montería, lo que sugiere la necesidad de estudiosadicionales para determinar su participación en síndromes respiratorios y problemasreproductivos; de comprobarse sus implicaciones clínicas en hatos bovinos de esta región,sería necesario implementar medidas adecuadas para su control y prevención

Integrated multiple mediation analysis: A robustness–specificity trade-off in causal structure

Recent methodological developments in causal mediation analysis have addressed several issues regarding multiple mediators. However, these developed methods differ in their definitions of causal parameters, assumptions for identification, and interpretations of causal effects, making it unclear which method ought to be selected when investigating a given causal effect. Thus, in this study, we construct an integrated framework, which unifies all existing methodologies, as a standard for mediation analysis with multiple mediators. To clarify the relationship between existing methods, we propose four strategies for effect decomposition: two-way, partially forward, partially backward, and complete decompositions. This study reveals how the direct and indirect effects of each strategy are explicitly and correctly interpreted as path-specific effects under different causal mediation structures. In the integrated framework, we further verify the utility of the interventional analogues of direct and indirect effects, especially when natural direct and indirect effects cannot be identified or when cross-world exchangeability is invalid. Consequently, this study yields a robustness–specificity trade-off in the choice of strategies. Inverse probability weighting is considered for estimation. The four strategies are further applied to a simulation study for performance evaluation and for analyzing the Risk Evaluation of Viral Load Elevation and Associated Liver Disease/Cancer data set from Taiwan to investigate the causal effect of hepatitis C virus infection on mortality

Tooth development and replacement in the Atlantic Cutlassfish, Trichiurus lepturus, with comparisons to other Scombroidei

Atlantic Cutlassfish, Trichiurus lepturus, have large, barbed, premaxillary and dentary fangs, and sharp dagger-shaped teeth in their oral jaws. Functional teeth firmly ankylose to the dentigerous bones. We used dry skeletons, histology, SEM, and micro-CT scanning to study 92 specimens of T. lepturus from the western North Atlantic to describe its dentition and tooth replacement. We identified three modes of intraosseous tooth replacement in T. lepturus depending on the location of the tooth in the jaw. Mode 1 relates to replacement of premaxillary fangs, in which new tooth germs enter the lingual surface of the premaxilla, develop horizontally, and rotate into position. We suggest that growth of large fangs in the premaxilla is accommodated by this horizontal development. Mode 2 occurs for dentary fangs: new tooth germs enter the labial surface of the dentary, develop vertically, and erupt into position. Mode 3 describes replacement of lateral teeth, in which new tooth germs enter a trench along the crest of the dentigerous bone, develop vertically, and erupt into position. Such distinct modes of tooth replacement in a teleostean species are unknown. We compared modes of replacement in T. lepturus to 20 species of scombroids to explore the phylogenetic distribution of these three replacement modes. Alternate tooth replacement (in which new teeth erupt between two functional teeth), ankylosis, and intraosseous tooth development are plesiomorphic to Bluefish + other Scombroidei. Our study highlights the complexity and variability of intraosseous tooth replacement. Within tooth replacement systems, key variables include sites of formation of tooth germs, points of entry of tooth germs into dentigerous bones, coupling of tooth germ migration and bone erosion, whether teeth develop horizontally or immediately beneath the tooth to be replaced, and how tooth eruption and ankylosis occur. Developmentally different tooth replacement processes can yield remarkably similar dentitions

Psychiatric genome-wide association study analyses implicate neuronal, immune and histone pathways

Genome-wide association studies (GWAS) of psychiatric disorders have identified multiple genetic associations with such disorders, but better methods are needed to derive the underlying biological mechanisms that these signals indicate. We sought to identify biological pathways in GWAS data from over 60,000 participants from the Psychiatric Genomics Consortium. We developed an analysis framework to rank pathways that requires only summary statistics. We combined this score across disorders to find common pathways across three adult psychiatric disorders: schizophrenia, major depression and bipolar disorder. Histone methylation processes showed the strongest association, and we also found statistically significant evidence for associations with multiple immune and neuronal signaling pathways and with the postsynaptic density. Our study indicates that risk variants for psychiatric disorders aggregate in particular biological pathways and that these pathways are frequently shared between disorders. Our results confirm known mechanisms and suggest several novel insights into the etiology of psychiatric disorders

Estudio serológico sobre neosporosis en bovinos con problemas reproductivos en Montería, Córdoba, Colombia

Objetivo. Determinar la presencia de anticuerpos contra N. caninum en vacas con desordenes reproductivos. Materiales y métodos. Se utilizaron muestras de suero de 196 vacas procedentes de 27 fincas del municipio de Montería, Colombia. La prueba utilizada para la determinación de anticuerpos fue ELISA. Los criterios de inclusión para las vacas fueron: antecedentes de aborto, momificaciones, reabsorciones embrionarias y repetición de servicios. Resultados. El estudio determinó una seropositividad contra N. caninum del 10,2%. De los animales muestreados, el 10,76% presentaron abortos, 9,75% fueron vacas repetidoras de celo, 20.0% presentaron momificación fetal y 0.0% con reabsorciones embrionarias. Conclusiones. Con base en los resultados se puede afirmar que existe evidencia de circulación antigénica de N. caninum en hembras bovinas del municipio de Montería, Colombia

A genome-wide scan for common alleles affecting risk for autism

Although autism spectrum disorders (ASDs) have a substantial genetic basis, most of the known genetic risk has been traced to rare variants, principally copy number variants (CNVs). To identify common risk variation, the Autism Genome Project (AGP) Consortium genotyped 1558 rigorously defined ASD families for 1 million single-nucleotide polymorphisms (SNPs) and analyzed these SNP genotypes for association with ASD. In one of four primary association analyses, the association signal for marker rs4141463, located within MACROD2, crossed the genome-wide association significance threshold of P < 5 × 10−8. When a smaller replication sample was analyzed, the risk allele at rs4141463 was again over-transmitted; yet, consistent with the winner's curse, its effect size in the replication sample was much smaller; and, for the combined samples, the association signal barely fell below the P < 5 × 10−8 threshold. Exploratory analyses of phenotypic subtypes yielded no significant associations after correction for multiple testing. They did, however, yield strong signals within several genes, KIAA0564, PLD5, POU6F2, ST8SIA2 and TAF1C

Molecular and cellular mechanisms underlying the evolution of form and function in the amniote jaw.

The amniote jaw complex is a remarkable amalgamation of derivatives from distinct embryonic cell lineages. During development, the cells in these lineages experience concerted movements, migrations, and signaling interactions that take them from their initial origins to their final destinations and imbue their derivatives with aspects of form including their axial orientation, anatomical identity, size, and shape. Perturbations along the way can produce defects and disease, but also generate the variation necessary for jaw evolution and adaptation. We focus on molecular and cellular mechanisms that regulate form in the amniote jaw complex, and that enable structural and functional integration. Special emphasis is placed on the role of cranial neural crest mesenchyme (NCM) during the species-specific patterning of bone, cartilage, tendon, muscle, and other jaw tissues. We also address the effects of biomechanical forces during jaw development and discuss ways in which certain molecular and cellular responses add adaptive and evolutionary plasticity to jaw morphology. Overall, we highlight how variation in molecular and cellular programs can promote the phenomenal diversity and functional morphology achieved during amniote jaw evolution or lead to the range of jaw defects and disease that affect the human condition