232 research outputs found

    Adaptación de la madera de Eucalyptus globulus a la normativa europea de durabilidad natural

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    La madera de Eucalyptus globulus en algunos países como Australia es recomendada para situaciones de riesgo de ataque de organismos xilófagos por su elevada durabilidad. En Galicia esta madera ha sido utilizada desde hace muchas décadas en estructuras y carpinterías, que aún hoy perduran. Sin embargo, la norma europea EN-350-2 encuadra la especie E. globulus en la peor categoría de durabilidad natural, situación que no se corresponde con la realidad. El objetivo de este proyecto es constatar la durabilidad de esta especie frente a hongos de pudrición e insectos xilófagos y modificar en consecuencia la clase de durabilidad asignada en la norma europea. Con este fin se están realizando los correspondientes ensayos frente a hongos e insectos xilófagos, tanto en laboratorio como en campo. Los resultados que se han obtenido con los hongos de pudrición fibrosa y pudrición blanda indican que, efectivamente, el duramen es durable (clase 2), mientras que la albura no es durable (clase 4) y la madera juvenil es medianamente durable (clase 3). De este modo, se confirma la elevada durabilidad del duramen de eucalipto, a la espera de finalizar los ensayos en curso y obtener los resultados finales.__________________________In some countries as Australia the wood of Eucalyptus globulus is recommended for its high durability in risk situations where attack by organisms is likely to occur. In Galicia this species has been utilised since many decades for timber structures, which are still in service. But the European Standard EN-350-2 qualifies Eucalyptus globulus with the worst category of natural durability, situation that does not correspond with the reality. The objetive of this project is to determine the durability of the species against wood decay fungi and wood boring insects and to accordingly classify E. globulus in the mentioned standard. To achieve this objective laboratory and field tests against fungi and insect attack are carried out. The preliminary results of the laboratory tests with white and soft rot indicate that the heartwood is durable (class 2), sapwood is not durable (class 4) and juvenil wood is moderately durable (class 3). These results confirm the high durability of the heartwood of this species, pending the end of the remaining tests

    Durabilidad natural del carrizo (Phragmites australis) frente a organismos xilófagos: relación con otras especies forestales

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    This work presents the research carried out to determine the natural durability of reed (Phragmites communis) from the Fertö region of Hungary against wood decay organisms, with the objective of obtaininig information to be used as a constituent element in outdoor use, and in particular, in a viable and sustainable motorway noise barrier. Phragmites communis is a large perennial grass of considerable size which grows in temperate and tropical wetland zones throughout the world. Its growth is expansive and it frequently invades wetlands where it competes with the native species and therefore requires regular removal so that an excess of organic material is not produced in the habitat. In addition, the invasion by this plant of polluted waters also appears to have a beneficial effect, so it can be used as a natural water purifier and thus has a potential use as a purification method for wetlands contaminated by agricultural practices. Due to the need for its periodic extraction, its possible use as a construction material, although in a secondary role, gives it an added value for which further scientific study is required. In the absence of a reference Standard and being reed a lignocellulose material, the study of its natural durability has been based on the existing Standards for wood. The tests show that Hungarian reed has a high level of durability against some fungi and other wood decay organisms. Key words: Reed, sustainable noise barrier, durability, wood decay organisms.Este trabajo presenta las investigaciones llevadas a cabo para determinar la durabilidad natural de Phragmites communis procedente de la región de Fertö, Hungría, frente a organismos xilófagos, con el objetivo de ser utilizado en el exterior, y en particular, como parte fundamental de una barrera acústica sostenible para carretera. Phragmites communis es una gramínea de gran tamaño que se desarrolla en humedales de zonas templadas y tropicales de todo el mundo. Suele utilizarse como herramienta natural para la depuración de aguas, y es especialmente relevante su uso potencial como depurador de humedales contaminados por las prácticas agrícolas. Debido a la necesidad de extraerlo periódicamente, las investigaciones que se realicen para su posible uso como material de construcción ofrecerían un valorañadido. Dada la ausencia de una normativa de referencia, y dado que el carrizo es un material lignocelulósico, el estudio de su durabilidad natural se ha enfocado a partir de las normas existentes para madera. Los ensayos demuestran que la durabilidad del carrizo húngaro es alta frente a algunos hongos y organismos xilófagos

    Clinical characterization of patients with anal fistula during follow-up of anorectal abscess: a large population-based study

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    PurposeApproximately 15-50% of patients with an anorectal abscess will develop an anal fistula, but the true incidence of this entity is currently unknown. The aim of the study was to determine the incidence of anorectal abscess and development of a fistula in a specific population area and to identify potential risk factors associated with demographic, socioeconomic and pre-existing disease (e.g. diabetes and inflammatory bowel disease).MethodsA longitudinal observational study was designed including a large cohort study in an area with 7,553,650 inhabitants in Spain 1st january 2014 to 31st december 2019. Adults who attended for the first time with an anorectal abscess and had a minimum of 1-year follow-up were included. The diagnosis was made using ICD-10 codes for anorectal abscess and anal fistula.ResultsDuring the study period, we included 27,821 patients with anorectal abscess. There was a predominance of men (70%) and an overall incidence of 596 per million population. The overall incidence of anal fistula developing from abscesses was 20%, with predominance in men, and a lower incidence in the lowest income level. The cumulative incidence of fistula was higher in men and in younger patients (p < 0.0001). On multivariate analysis, patients aged 60-69 years (hazard ratio 2.0) and those with inflammatory bowel disease (hazard ratio 1.8-2.0) had a strong association with fistula development (hazard ratio 2.0).ConclusionsOne in five patients with an anorectal abscess will develop a fistula, with a higher likelihood in men. Fistula formation was strongly associated with inflammatory bowel disease

    Characterization of function of the GlgA2 glycogen/starch synthase in Cyanobacterium sp. Clg1 highlights convergent evolution of glycogen metabolism into starch granule aggregation

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    At variance with the starch-accumulating plants and most of the glycogen-accumulating cyanobacteria, Cyanobacterium sp. CLg1 synthesizes both glycogen and starch. We now report the selection of a starchless mutant of this cyanobacterium that retains wild-type amounts of glycogen. Unlike other mutants of this type found in plants and cyanobacteria, this mutant proved to be selectively defective for one of the two types of glycogen/starch synthase: GlgA2. This enzyme is phylogenetically related to the previously reported SSIII/SSIV starch synthase that is thought to be involved in starch granule seeding in plants. This suggests that, in addition to the selective polysaccharide debranching demonstrated to be responsible for starch rather than glycogen synthesis, the nature and properties of the elongation enzyme define a novel determinant of starch versus glycogen accumulation. We show that the phylogenies of GlgA2 and of 16S ribosomal RNA display significant congruence. This suggests that this enzyme evolved together with cyanobacteria when they diversified over 2 billion years ago. However, cyanobacteria can be ruled out as direct progenitors of the SSIII/SSIV ancestral gene found in Archaeplastida. Hence, both cyanobacteria and plants recruited similar enzymes independently to perform analogous tasks, further emphasizing the importance of convergent evolution in the appearance of starch from a preexisting glycogen metabolism network.Peer Reviewe

    From Pre‐Roman Bailo To Roman Baelo: Long‐Term Landscape Dynamics In The Straits Of Gibraltar

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    The Straits of Gibraltar have been historically an important maritime axis of connection between the Mediterranean and Atlantic areas of the Iberian Peninsula. For this reason, most of the archaeological research has focused on the coastal settlements, but its broader archaeological landscape remains mostly unknown. In this paper, we present recent intensive surveys in which a wide range of sites was detected, dating from the eighth century BC to the fourteenth AD. The ancient landscape is thus reconstructed over a long‐term perspective. Prior to the Roman expansion, the earlier Bailo‐La Silla del Papa was an urban central place that supported a dense network of subordinate settlements. Later on, the central settlement was transported from inland to the coastal town of Baelo Claudia, but the territorial structure remained based on a similar pattern.This study has been carried out as part of the Franco-German (Agence Nationale de la Recherche Scientifique and Deutsche Forschungsgemeinschaft) project – ARCHEOSTRAITS. Espaces protohistoriques du détroit de Gibraltar: les territoires de la Silla del Papa et de Los Castillejos de Alcorrín (IXe – Ier siècle av. J.-C.) – led by D.Marzoli and P.Moret. In this article we have presented the analysis of the Atlantic sector, drawing on a study included in a Junta de Andalucía General Research Project led by P. Moret – La Silla del Papa (Tarifa, Cádiz): oppidum, necropolis and territory (2014-2019)

    Conservation threats and future prospects for the freshwater fishes of Ecuador: A hotspot of Neotropical fish diversity

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    Freshwater fish communities in Ecuador exhibit some of the highest levels of diversity and endemism in the Neotropics. Unfortunately, aquatic ecosystems in the country are under serious threat and conditions are deteriorating. In 2018–19, the government of Ecuador sponsored a series of workshops to examine the conservation status of Ecuador''s freshwater fishes. Concerns were identified for 35 species, most of which are native to the Amazon region, and overfishing of Amazonian pimelodid catfishes emerged as a major issue. However, much of the information needed to make decisions across fish groups and regions was not available, hindering the process and highlighting the need for a review of the conservation threats to Ecuador''s freshwater fishes. Here, we review how the physical alteration of rivers, deforestation, wetland and floodplain degradation, agricultural and urban water pollution, mining, oil extraction, dams, overfishing, introduced species and climate change are affecting freshwater fishes in Ecuador. Although many of these factors affect fishes throughout the Neotropics, the lack of data on Ecuadorian fish communities is staggering and highlights the urgent need for more research. We also make recommendations, including the need for proper enforcement of existing environmental laws, restoration of degraded aquatic ecosystems, establishment of a national monitoring system for freshwater ecosystems, investment in research to fill gaps in knowledge, and encouragement of public engagement in citizen science and conservation efforts. Freshwater fishes are an important component of the cultural and biological legacy of the Ecuadorian people. Conserving them for future generations is critical. © 2021 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles

    Darunavir/cobicistat/emtricitabine/tenofovir alafenamide versus dolutegravir /abacavir/lamivudine in antiretroviral-naïve adults (SYMTRI): a multicenter randomized open-label study (PReEC/RIS-57)

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    D/C/F/TAF is the reference for combination therapy based on protease inhibitors but has not been compared with regimens containing integrase inhibitors as initial ART. We could not demonstrate D/C/F/TAF noninferiority relative to DTG/ABC/3TC, although both regimens were similarly well tolerated. Background Darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) is the reference for combination therapy based on protease inhibitors due to its efficacy, tolerability, and convenience. Head-to-head randomized comparisons between D/C/F/TAF and combination therapy based on integrase inhibitors in antiretroviral-naive patients are lacking. Methods Adult (>18 years old) human immunodeficiency virus-infected antiretroviral-naive patients (HLA-B*5701 negative and hepatitis B virus negative), with viral load (VL) >= 500 c/mL, were centrally randomized to initiate D/C/F/TAF or dolutegravir/abacavir/lamivudine (DTG/3TC/ABC) after stratifying by VL and CD4 count. Clinical and analytical assessments were performed at weeks 0, 4, 12, 24, and 48. The primary endpoint was VL 100 000 copies/mL, and 13% had <200 CD4 cells/mu L. Median weight was 73 kg and median body mass index was 24 kg/m(2). At 48 weeks, 79% (D/C/F/TAF) versus 82% (DTG/3TC/ABC) had VL <50 c/mL (difference, -2.4%; 95% confidence interval [CI], -11.3 to 6.6). Eight percent versus four percent experienced virologic failure but no resistance-associated mutations emerged. Four percent versus six percent had drug discontinuation due to adverse events. In the per-protocol analysis, 94% versus 96% of patients had VL <50 c/mL (difference, -2%; 95% CI, -8.1 to 3.5). There were no differences in CD4 cell count or weight changes. Conclusions We could not demonstrate the noninferiority of D/C/F/TAF relative to DTG/ABC/3TC as initial antiretroviral therapy, although both regimens were similarly well tolerated
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