Descripción geoquímica y geocronológica de secuencias volcánicas neógenas de Trasarco, en el extremo oriental de la Cadena Volcánica Transversal del Quevar (Noroeste de Argentina)

Se realizaron 34 nuevas dataciones K/Ar y 39 análisis geoquímicos de elementos mayoritarios, trazas y tierras raras, que implican nuevas aportaciones sobre las secuencias volcánicas neógenas de trasarco pertenecientes a la cadena volcánica transversal del Quevar. Esta cadena volcánica parte del arco volcánico actual con dirección W N W-ESE hasta las cercanías de la localidad de San Antonio de los Cobres. Se han reconocido y estudiado centros volcánicos ubicados en el extremo oriental de la misma. Los diferentes pulsos detectados en cada uno de estos centros (Aguas Calientes, Acay, El Morro-Orrganullo y Tocomar) son geoquímica y petrogr á ficamente homogéneos. Se interpreta que las cámaras magmáticas involucradas no han estado estratificadas composicionalmente ni han tenido sectores enriquecidos en cristales. Como excepción, el centro eruptivo Acay muestra un rango composicional desde términos andesíticos a riolíticos. En este caso, se interpreta un fraccionamiento de la cámara magmática en pulsos de edad similar. La composición isotópica del centro eruptivo Aguas Calientes indica una fuerte componente cortical en la formación de los magmas. Es posible explicar su origen a partir de fusión cortical. Las determinaciones geocronológicas realizadas muestran pulsos volcánicos a los 17-19 Ma, 13-12 Ma, 10 Ma, 7-6 Ma, 1-0.5 Ma en esta región de los Andes Centrales.New geochronological data (34) and 39 new geochemical analyses have been made in the Neogene backarc volcanic sequences in the “El Quevar Transversal Volcanic Chain” defined by Viramonte et al (1984a). This chain starts at the present N-S arc with WNW-ESE trend. New volcanic centres have been recognised and analysed at the eastern end of this chain. The different pulses from each volcanic centre (Aguas Calientes, Acay, El Morro - Organullo and Tocomar) are petrographically and geochemically homogeneous. This suggests that the magma chambers related in each volcano, were geochemically homogeneous and did not have crystal enriched sectors. The Acay eruptive centre is an exception of this assumption; a compositionally differentiated magmatic chamber could be inferred. The isotopic composition of the Aguas Calientes emission centre has a crust signature in its origin, related with melts generated by crustal fussion. The geochronological determinations show volcanic pulses at 17-19 Ma, 13-12 Ma, 10 Ma, 7-6 Ma, 1-0.5 Ma in this region of the Central Andes

Teacher reports of peer aggression in preschool: its relationship to DSM-IV externalizing symptoms

Objetivo: Determinar la prevalencia de agresión preescolar hacia iguales en la comunidad y su correlación con categorías externalizantes del DSM-IV. Método: La muestra fue de 1104 niños de 3 a 6 años, procedentes de aulas preescolares urbanas y rurales. Se aplicó a los maestros la Peer Conflict Scale (PCS), para recabar información de agresiones físicas directas, verbales, con objetos y simbólicas, y el cuestionario de psicopatología ECI-IV. Resultados: Un 6.6% (n = 73) puntuó positivamente por lo menos en un item de la PCS. Este porcentaje decreció hasta un 2.6 % (n = 29) con una definición de caso más exigente (mínimo tres ítems positivos). La agresión física directa fue la forma más frecuente de agresión seguida de agresión verbal y agresión con objetos. Hubo diferencias significativas según edad y sexo. La agresión dirigida a iguales se asocia al sexo masculino desde los 3 años. La agresión física directa, con objetos y verbal correlaciona con trastornos externalizantes, principalmente con trastornos oposicionistas. Conclusiones: Esta investigación en población española confirma la existencia de agresividad hacia iguales en preescolares así como diferencias según sexo. Nuestra principal aportación es haber encontrado diferencias de sexo en el inicio y en los tipos de agresividad hacia iguales.Objective: to establish the prevalence and associations of peer aggression as manifested in preschool children, in community-based populations and to study links with DSM-IV externalizing diagnoses. Method: Subjects were 1,104 children, 3-to-5-year-olds attending rural and urban pre-schools classes. Teachers completed the Peer Conflict Scale (PCS) to inform about direct physical and verbal aggression, object aggression and symbolic aggression and the questionnaire on psychopathology ECI-4. Results: 6.6% (n = 73) had at least one positive item on the PCS. This percentage dropped to 2.6% (n = 29) if we take into account a minimum of three positive items. Physical direct aggression was the more prevalent type of aggressive behavior, followed by verbal aggression, object aggression and symbolic aggression. Significant differences by gender and age were found. Peer aggression was associated with male gender from three years of age. Physical, object and verbal aggressive behavior was linked with externalizing disorders. This association was very strong with oppositional disorder. Conclusions: The present research with a Spanish population confirms the existence of peer aggression in preschoolers and the gender differences. Our chief contribution is about the age of emergence of sex differences and gender differences in different types of peer aggression

Hepatic changes during a carrageenan induced granuloma in rats

Hepatic changes during inflammation were studied in rats bearing a carrageenan induced granuloma. In spite of a decrease in the metabolic capacity of microsomes to induce lipid peroxidation during inflammation, the endogenous lipid peroxidation remained unchanged and unrelated with the hepatic activities measured. The continuous increase in hepatic cAMP observed during acute and chronic phases could be related to adenylate cyclase stimulation by mediators, and could be an initial step in the hepatocyte adaptation leading to the increased level of hepatic caeruloplasmin, to the reduction of cytochrome P-450 level and to the modifications of Ca2+ sequestration by microsomes

Interview investigation of insecure attachment styles as mediators between poor childhood care and schizophrenia-spectrum phenomenology

Background Insecure attachment styles have received theoretical attention and some initial empirical support as mediators between childhood adverse experiences and psychotic phenomena; however, further specificity needs investigating. The present interview study aimed to examine (i) whether two forms of poor childhood care, namely parental antipathy and role reversal, were associated with subclinical positive and negative symptoms and schizophrenia-spectrum personality disorder (PD) traits, and (ii) whether such associations were mediated by specific insecure attachment styles. Method A total of 214 nonclinical young adults were interviewed for subclinical symptoms (Comprehensive Assessment of At-Risk Mental States), schizophrenia-spectrum PDs (Structured Clinical Interview for DSM-IV Axis II Disorders), poor childhood care (Childhood Experience of Care and Abuse Interview), and attachment style (Attachment Style Interview). Participants also completed the Beck Depression Inventory-II and all the analyses were conducted partialling out the effects of depressive symptoms. Results Both parental antipathy and role reversal were associated with subclinical positive symptoms and with paranoid and schizotypal PD traits. Role reversal was also associated with subclinical negative symptoms. Angry-dismissive attachment mediated associations between antipathy and subclinical positive symptoms and both angry-dismissive and enmeshed attachment mediated associations of antipathy with paranoid and schizotypal PD traits. Enmeshed attachment mediated associations of role reversal with paranoid and schizotypal PD traits. Conclusions Attachment theory can inform lifespan models of how adverse developmental environments may increase the risk for psychosis. Insecure attachment provides a promising mechanism for understanding the development of schizophrenia-spectrum phenomenology and may offer a useful target for prophylactic intervention

Descripción geoquímica y geocronológica de secuencias volcánicas neógenas de Trasarco, en el extremo oriental de la Cadena Volcánica Transversal del Quevar (Noroeste de Argentina)

New geochronological data (34) and 39 new geochemical analyses have been made in the Neogene backarc volcanic sequences in the “El Quevar Transversal Volcanic Chain” defined by Viramonte et al (1984a). This chain starts at the present N-S arc with WNW-ESE trend. New volcanic centres have been recognised and analysed at the eastern end of this chain. The different pulses from each volcanic centre (Aguas Calientes, Acay, El Morro - Organullo and Tocomar) are petrographically and geochemically homogeneous. This suggests that the magma chambers related in each volcano, were geochemically homogeneous and did not have crystal enriched sectors. The Acay eruptive centre is an exception of this assumption; a compositionally differentiated magmatic chamber could be inferred. The isotopic composition of the Aguas Calientes emission centre has a crust signature in its origin, related with melts generated by crustal fussion. The geochronological determinations show volcanic pulses at 17-19 Ma, 13-12 Ma, 10 Ma, 7-6 Ma, 1-0.5 Ma in this region of the Central Andes

Oxidative stress in pregnancy and fertility pathologies

Oxidative stress designates the state of imbalance between reactive oxygen species (ROS) production and antioxidant levels. In a healthy placenta, there is an increase in ROS production, due to formation of new tissues and inherent metabolism, but this is balanced by higher levels of antioxidants. However, this balance is lost in some situations, with a consequent increase in oxidative stress levels. Oxidative stress has been implicated in several placental disorders and pregnancy pathologies. The present review intends to summarize what is known about the relationship between oxidative stress and well-known pregnancy disorders

Decoding the regulatory network of early blood development from single-cell gene expression measurements.

Reconstruction of the molecular pathways controlling organ development has been hampered by a lack of methods to resolve embryonic progenitor cells. Here we describe a strategy to address this problem that combines gene expression profiling of large numbers of single cells with data analysis based on diffusion maps for dimensionality reduction and network synthesis from state transition graphs. Applying the approach to hematopoietic development in the mouse embryo, we map the progression of mesoderm toward blood using single-cell gene expression analysis of 3,934 cells with blood-forming potential captured at four time points between E7.0 and E8.5. Transitions between individual cellular states are then used as input to develop a single-cell network synthesis toolkit to generate a computationally executable transcriptional regulatory network model of blood development. Several model predictions concerning the roles of Sox and Hox factors are validated experimentally. Our results demonstrate that single-cell analysis of a developing organ coupled with computational approaches can reveal the transcriptional programs that underpin organogenesis.We thank J. Downing (St. Jude Children's Research Hospital, Memphis, TN, USA) for the Runx1-ires-GFP mouse. Research in the authors' laboratory is supported by the Medical Research Council, Biotechnology and Biological Sciences Research Council, Leukaemia and Lymphoma Research, the Leukemia and Lymphoma Society, Microsoft Research and core support grants by the Wellcome Trust to the Cambridge Institute for Medical Research and Wellcome Trust - MRC Cambridge Stem Cell Institute. V.M. is supported by a Medical Research Council Studentship and Centenary Award and S.W. by a Microsoft Research PhD Scholarship.This is the accepted manuscript for a paper published in Nature Biotechnology 33, 269–276 (2015) doi:10.1038/nbt.315