Inversión de los patrones estacionales de la absorción de carbono en un stand de eucalipto en Portugal

This paper summarizes results between 2002 and 2010 from eddy covariance measurements of carbon uptake in the 12 month annual growing period eucalypt site of Espirra in Southern Portugal (38° 38’N, 8° 36’ W) . This site, aimed for pulp production is part of an intensively 300 ha eucalypt coppice, with about 1100 trees ha–1. The climate is of Mediterranean type. During the measurement period (2002-2010) two main events changed the annual sink pattern of the forest: a drought period of two years (2004-2005) and a tree felling (November and December 2006). Before the felling, annual net ecosystem exchange (NEE) diminished from 865.56 gCm–2 in 2002 to 356.64 gCm–2 in 2005 together with a deep decrease in rainfall from 748 mm in 2002 to 378.58 mm and 396.64 mm in 2004 and 2005, respectively. The eucalypt stand recovered its carbon sink ability in June 2007 with a cumulated NEE of 151 gCm–2 from January to September 2010. A quantitative approach using generalized estimating equations (GEEs) was made to relate monthly NEE, gross primary production (GPP) and soil moisture with the main meteorological variables. Seasonal patterns of carbon uptake were almost opposite in the periods before and after the felling with maxima in April and August, respectively, and this seasonal change is gradually reversing to the pattern before 2006. Drought was the main meteorological driver of these temporal tendencies in carbon uptake.Este documento resume los resultados entre 2002 y 2010 a partir de mediciones de covarianza turbulenta de la absorción de carbono en los 12 meses anuales a los sitios de crecimiento de eucalipto período de Espirra en el sur de Portugal (38° 38’N, 8° 36’ W). Este sitio, con el objetivo para la producción de celulosa es parte de un monte bajo de intensidad 300 hectáreas de eucaliptos, con cerca de 1.100 árboles ha–1. El clima es de tipo mediterráneo. Durante el período de medición (2002-2010) dos eventos principales cambiado el patrón fregadero anual de la selva: un período de sequía de dos años (2004-2005) y la tala de árboles (noviembre y diciembre de 2006). Antes de la tala, el intercambio anual neta de los ecosistemas (NEE) se redujo de 865,56 g cm–2 en 2002 a 356,64 g cm–2 en 2005, junto con una disminución profunda de las precipitaciones de 748 mm en 2002 a 378,58 mm y 396,64 en 2004 y 2005, respectivamente. El eucalipto de pie recupera su capacidad de sumidero de carbono en junio de 2007 con un acumulado de 151 gcm NEE–2 de enero a septiembre de 2010.Una aproximación cuantitativa mediante ecuaciones de estimación generalizada (GEES) se hizo para relacionar mensual NEE, la producción primaria bruta (GPP) y la humedad del suelo con las variables meteorológicas principales.Los patrones estacionales de la absorción de carbono eran casi opuestas en los períodos antes y después de la tala, con máximos en abril y agosto, respectivamente, y este cambio de temporada se va de marcha atrás para el patrón antes de 2006. La sequía fue el principal impulsor de estas tendencias meteorológicas temporal en la absorción de carbono

Variscan overthrusting, fluid flow and the genesis of magnetite ore-bodies at Azenhas area (Pedrógão, Ossa-Morena Zone, SE Portugal)

In the Azenhas area (SE Portugal), an important segment of a regional WNW-ESE Variscan thrust can be observed. The hanging wall felsic metavolcanics carried from ENE are evolved rhyolite tuffs. The underlying sequence is mainly composed of variably metasomatised allochthonous amphibolites that are believed to represent an ophiolite slice tectonically overlying the autochthonous Moura-Ficalho Complex. Within this latter sequence, numerous WNW-ESE thrusts with prevailing displacement towards W-SW cut prior sub-parallel structures with northwards thrust shear. According to the observed crosscutting relationships and to the available petrographic data, the metasomatism experienced by the lower amphibolite sequence took place mainly before the emplacement of the upper slices of amphibolites, preceding therefore the installation of the felsic metatuffs. Magnetite ore-bodies are found within strongly metasomatised amphibolites immediately below the major WNW-ESE thrust zone or its subsidiary thrust structures. Their genesis is envisaged as a result of a complex chemical reaction path that involves the ascent of aqueous oxidising fluids under a reverse temperature gradient generated during the tectonic emplacement of amphibolites. In order to test the geological plausibility of the thermal evolution and the time span needed for ore genesis a one-dimensional numerical model was developed. This model enables the tracing of vertical thermal profiles at different times and accounts for the thrust emplacement history, incorporating variable erosion rates of the rock sequence. The results obtained show that an inverted thermal gradient in the thrusted sequence is kept for over 1 Ma and a regular temperature increase (from 400ºC to 500ºC) is observed in the underlying rocks lasting for 4.5 to 5.5 Ma.info:eu-repo/semantics/publishedVersio

Pneumatosis Cystoides Intestinalis Induced by Acarbose Treatment

A "Pneumatosis Cystoides Intestinalis" é uma situação clínica rara que se caracteriza pela presença de múltiplos quistos de conteúdo gasoso ao nível da submucosa ou subserosa na parede do tracto gastrointestinal. A pneumatose intestinal classifica-se em idiopática e secundária. Na última forma admite-se uma relação causal com doença pulmonar obstrutiva crónica, conectivites, amiloidose, colites infecciosas, oclusão intestinal, isquémia, doença de Crohn, fármacos e iatrogenia cirúrgica e endoscópica. O espectro de manifestações clínicas compreende dor abdominal, oclusão intestinal, diarreia e hemorragia digestiva. Todavia, é frequentemente assintomática ou constitui um achado incidental no decurso de uma investigação não relacionada. Os autores apresentam o caso clínico de uma doente com pneumatose quística intestinal associada à utilização terapêutica de um antidiabético oral - acarbose (inibidor da alfa-glucosidase)

Assessment of the risk of Hepatitis E virus occurrence in pork carcasses at slaughter in the UK

Hepatitis E virus (HEV) is a RNA virus of the genus Hepevirus. HEV genotype 3 is zoonotic and pigs are the main reservoir. This genotype has been identified in the United Kingdom, in sporadic locally-acquired cases without recent history of foreign travel to endemic countries. The number of HEV-confirmed human cases in the UK has increased significantly, from 124 cases in 2003 to 661 in 2013. Non-travel cases now account for the majority (69%) of cases observed annually in the UK. Our aim was to assess the risk of HEV occurrence in pork carcases at slaughter in the UK. We performed a quantitative exposure assessment using Monte Carlo simulation to estimate the number of carcasses contaminated with HEV produced in a high throughput porcine abattoir during one year. The input data used were: a) true prevalence in British pigs, b) probability of viral shedding in bile and faeces c) number of pig carcases with bile and/or faecal contamination detected during post-mortem inspection. The following assumptions were made when data were unavailable: a) sensitivity and specificity of the RP-PCR diagnostic test; b) meat from viraemic pigs was considered HEV-positive; c) visual faecal and bile contamination only considered since microscopic contamination would not be detected through visual inspection. We estimated through our model that 175,152 (2.4%) of carcases produced in high throughput abattoirs would be infected with HEV in one year period. The number of viraemic pigs slaughtered at the abattoir was the largest driver of the uncertainty in carcass contamination. Variations in this parameter would change the output from 62,982 carcasses up to 306,320. Mitigation strategies at farm level should be explored, as it appears that control at this level would likely result in a higher reduction in HEV contamination in pork meat