The dysfunction of T follicular helper cells.

PURPOSE OF REVIEW: T follicular helper (Tfh) cells play a critical role as providers of B-cell help and dysfunction in Tfh/B-cell interactions can lead to autoimmunity or immunodeficiency. These observations have generated a great deal of interest in understanding how these cells are affected during HIV infection and how their functional changes might affect antibody responses. RECENT FINDINGS: Recent studies have shown that HIV/simian immunodeficiency virus (SIV) infection affects both Tfh-cell frequency and function and suggest that Tfh-cell perturbations might contribute to the relative inefficiency of HIV-infected individuals to generate broadly neutralizing antibodies (bNAbs). SUMMARY: The present review will highlight these recent findings addressing the role of Tfh cells in HIV infection as well as the impact HIV infection has on Tfh and circulating memory Tfh (cTfh) cell frequency and function

Estrutura e composição florística de uma área de caíva com extração de erva-mate e pastejo animal no Planalto Norte Catarinense.

Caívas são remanescentes de Floresta Ombrófila Mista que se apresentam como fragmentos florestais de tamanhos variados nas propriedades rurais. A somatória desses fragmentos contribui para a formação da paisagem característica do Planalto Norte Catarinense (PNC) e parte do Centro-Sul Paranaense, formando um mosaico de áreas de cultivo intercaladas por áreas de florestas. Apesar de não ser computada especificamente nos censos agropecuários, sua estimativa é que estão presentes em aproximadamente 39% dos estabelecimentos rurais, ocupando em torno de 70.000 hectares no PNC. O presente trabalho teve como objetivo caracterizar a estrutura e composição florística de uma área de caíva cuja utilização, há mais de 60 anos, tem sido a extração de erva-mate nativa e o pastejo animal por rebanho bovino. A área experimental com 4.320 m2 foi demarcada dentro de uma caíva de aproximadamente 10 ha, localizada em uma propriedade rural no município de Canoinhas. Foram alocadas 27 parcelas amostrais com 144 m² cada, onde foi realizado o levantamento na área total da parcela. Foram medidos e identificados todos os indivíduos com DAP ? 5 cm e calculados os parâmetros fitossociológicos de densidade, frequência, dominância e valor de importância. Verificou-se a ocorrência de 418 indivíduos arbóreos, 12 famílias botânicas e 21 espécies. As famílias com maior número de espécies foram Myrtaceae (4), Aquifoliaceae (3) e Lauraceae (3); e as famílias com maior número de indivíduos foram Aquifoliaceae (240), Myrtaceae (83) e Annonaceae (43). O índice de diversidade de Shannon foi de 3,18, indicando considerável diversidade florística. As espécies que contribuíram para os maiores valores de importância foram: Ilex paraguariensis, Mosiera prismatica, Ocotea porosa e Rollinia rugulosa. Esses resultados confirmam que as caívas representam uma importante reserva de espécies de árvore nativas, mesmo sendo manejadas há longo tempo

Fuentes mantelicas y evolucion del volcanismo canario

A total of 74 samples of canarian volcanic rocks allows to show the variability of the magmatism. Isotopic relationships (Pb, Sr and Nd) limits the magmatic reservoirs to HIMU and EM2. The existence of sediments in the canarian crust would explain the contamination processes existing in some islands. The chondritic REE pattern indicates a fractional crystallization process for the canarian magmatic sequence, chemical changes observed in some basic rocks could be related to contamination processes.Una selección de 74 muestras de rocas volcánicas de las islas Canarias se ha utilizado para delimitar la variabilidad de los magmas canarios. Relaciones isotópicas de Pb, Sr y Nd situan las fuentes magmáticas como una mezcla de HIMU y EM2. La presencia de una corteza con un grosor variable de sedimentos explicaría el proceso de contaminación observable en algunas islas. El modelo condrítico de tierras raras indicaría un proceso de diferenciación magmática por cristalización fraccionada como el más apropiado para la secuencia magmática canaria. Algunos cambios composicionales observados en rocas básicas pueden estar en relación con procesos de contaminación

The Mazarrón basin, SE Spain: a study of mineralization processes, evolving magmatic series, and geothermal activity

The Miocene to Present Mazarrón basin provides a window on the metallogenic role of an evolving magmatic series. High-K calc–alkaline magmas gave rise to an important cluster of Pb–Zn–Ag–Cu vein and stockwork deposits emplaced in dacitic to rhyodacitic domes, part of a complex volcanic–metallogenic province (Au, Hg, Pb–Zn–Cu–Ag, Sn) stretching for ∼150 km along the Mediterranean coast of SE Spain. By Pliocene time the former magmatic series had been replaced by intraplate alkaline basaltic volcanism, thus becoming the southern branch of the Western/Central Europe alkaline province. In terms of base metal sulphide deposits, this European province is barren, although it triggered widespread, CO2-rich geothermal activity. Modern geothermal activity at El Saladillo (Mazarrón) resulted in the deposition of carbonate sinter deposits and formation of microbial mats. Proximal facies consist of millimetric to centimetric multicoloured layers of microbial mats, including yellow-orange thin bands of calcified bacteria and mineral growths of aragonite and calcite; green layers of live thermophilic Lyngbya-type cyanobacteria; black, degraded organic matter; and pyrite as the sole sulphide phase. Except for arsenic (37–63 μg g−1), all of the studied trace elements (Ag, Ba, Bi, Cd, Cu, Pb, Sb, Se, and Sn) appear in remarkably low concentrations in the geothermal sinters. This is consistent with compositional data for the El Saladillo waters, with no significant metal concentrations. We present the first conceptual model (Miocene to Present) for the ore-forming processes, magmatism, CO2 degasification, and geothermal activity for this realm. We argue that the time- and space-limited character of this volcanism (small, scattered outcrops), the deep magma emplacement level, the metal sulphide behaviour in alkaline basaltic magmatic chambers, and the dry character of these magmas prevented any metallogenic interaction between the chambers and the much shallower meteoric waters that drove the El Saladillo geothermal system and others of the same kind in Spain and elsewhere in Europe

La compatibilidad entre estudios y deporte en estudiantes de secundaria

The purpose of this research was to analysethe difficulties thathigh school studentshadto balance outstudiesandsports. Following adescriptiveexploratorymethodandthroughthe application of atestquestionnaireandconductinga discussion group, informationwascollectedin relation to fourkey factors: the characteristicsof the sport, the conflicts of interestemergedinbalancingstudiesand sport, the support and resources theyhadto bring togetherthisdoubleactivityandthetrainingand professional expectationsthatwereahead of theirfuture. Theanalysis of the differentfactors involved inthe development of thisdouble activity, constitutes afundamentalelement of reference sothatschoolsimplementmeasuresand actions that allow these students to continue with theirsports training, without having to give upeducation. The results obtainedhighlightthe difficulties thathigh school students havetocombineboth processes, which requires them greateffort, good planning ofgoals, appropriate organization of time andpersistenceinachievingthe objectives.La finalidad de esta investigación fue analizar las dificultades que los estudiantes de secundaria tenían para compatibilizar estudios y deportes. Siguiendo un método descriptivo de carácter exploratorio y a través de la aplicación de una prueba de cuestionario y la realización de un grupo de discusión, se recogió información en relación a cuatro factores clave: las características propias de la práctica deportiva, el conflicto de intereses surgido a la hora de compatibilizar los estudios y el deporte, los apoyos y recursos con los que contaban para armonizar esta doble actividad y las expectativas formativas y profesionales que tenían de cara a su futuro. El análisis de los distintos factores que intervienen en el desarrollo de esta doble actividad, constituye un elemento de referencia fundamental para que los centros educativos implanten medidas y acciones que permitan a estos estudiantes continuar con su preparación deportiva, sin tener que renunciar a la formación. Los resultados obtenidos ponen de manifiesto las dificultades que tienen los estudiantes de secundaria para compaginar ambos procesos, lo que les exige un gran esfuerzo, una buena planificación de metas, una adecuada organización del tiempo y persistencia en el logro de los objetivos planteados

Los domos sálicos de Tenerife, Islas Canarias

Morphological, petrological and geochemical features of the felsic domes in Tenerife are treated. Two main groups have been established: Old Edifices Domes and Recent Series Domes, subdivided in minor groups according to their volcano-stratigraphic position. There are many morphological types, each group showing different typical characters. Haüyne phonolites are the most common rocks, although nepheline phonolites and trachytes are also present. Chemical analysis indicate major abundance of undersaturated terms and higher differentiation in the Recent Series Domes than in the üld Edifices Domes. Both groups are clearly separated in usual diagrams and specially show different trends in Al, Fe, K, Ti, Nb, Y and Ce elementsSe estudian las características morfológicas, petrológicas y geoquímicas de los domos sálicos de Tenerife, separándolos en dos grupos: domos de los edificios antiguos y domos de las series recientes. A su vez en cada uno de éstos se han distinguido varios subgrupos atendiendo a su localización volcanoestratigráfica. Los tipos morfológicos son variados, cada uno de ellos con características particulares. Las rocas más comunes son fonolitas haüynicas, existiendo menor abundancia de fonolitas nefelínicas y de traquitas. Geoquímicamente se comprueba que los términos más abundantes son también los subsaturados, siendo los domos de las series recientes los más diferenciados. En distintos diagramas se observa que quedan bien separados los dos grandes grupos establecidos, los cuales presentan diferentes pautas de variación para algunos elementos tales como Al, Fe, K, Ti, Nb, Y Y Ce, entre otros

Caracterização dos principais ambientes pedológicos na Base de Operações Geólogo Pedro de Moura, Amazônia Central brasileira.

Trabalho apresentado no XVIII CLACS com o objetivo de, através de um número limitado de observações (perfis e tradagens) em combinação com uso de imagens de satélites e de radar, apresentar um mapa e uma legenda preliminar das principais classes de solos e de suas associações na área da Base de Operações Geólogo Pedro de Moura (BOGPM) no município de Coari na Amazônia Central brasileira, região de exploração de petróleo e gás na Amazônia

Neurobehavioral consequences of chronic intrauterine opioid exposure in infants and preschool children: a systematic review and meta-analysis

<b>Background</b><p></p> It is assumed within the accumulated literature that children born of pregnant opioid dependent mothers have impaired neurobehavioral function as a consequence of chronic intrauterine opioid use.<p></p> <b>Methods</b><p></p> Quantitative and systematic review of the literature on the consequences of chronic maternal opioid use during pregnancy on neurobehavioral function of children was conducted using the Meta-analysis of Observational Studies in Epidemiology (MOOSE) and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We searched Cinahl, EMBASE, PsychINFO and MEDLINE between the periods of January 1995 to January 2012.<p></p> <b>Results</b><p></p> There were only 5 studies out of the 200 identified that quantitatively reported on neurobehavioral function of children after maternal opioid use during pregnancy. All 5 were case control studies with the number of exposed subjects within the studies ranging from 33–143 and 45–85 for the controls. This meta-analysis showed no significant impairments, at a non-conservative significance level of p < 0.05, for cognitive, psychomotor or observed behavioural outcomes for chronic intra-uterine exposed infants and pre-school children compared to non-exposed infants and children. However, all domains suggested a trend to poor outcomes in infants/children of opioid using mothers. The magnitude of all possible effects was small according to Cohen’s benchmark criteria.<p></p> <b>Conclusions</b><p></p> Chronic intra-uterine opioid exposed infants and pre-school children experienced no significant impairment in neurobehavioral outcomes when compared to non-exposed peers, although in all domains there was a trend to poorer outcomes. The findings of this review are limited by the small number of studies analysed, the heterogenous populations and small numbers within the individual studies. Longitudinal studies are needed to determine if any neuropsychological impairments appear after the age of 5 years and to help investigate further the role of environmental risk factors on the effect of ‘core’ phenotypes