541 research outputs found

    Description of a peculiar Rhithrogena nymph from the Iberian Peninsula (Ephemeroptera, Heptageniidae)

    Get PDF
    Recent collecting in southern Portugal (Algarve) let to the discovery of an unusual Rhithrogena that possibly belongs to the so-called Rh. sowai group. The nymph of the species is described but not named, and affinities and relationships with other members from the Iberian Peninsula are discussed.Una especie poco frecuente de Rhithrogena, que posiblemente pertenece al llamado grupo Rh. sowai ha sido descubierta en unos muestreos realizados recientemente en el sur de Portugal (Algarve). En este trabajo se describe la ninfa de la especie pero no se le da nombre. Se discuten también las relaciones y afinidades con otros miembros del género de la Península Ibérica

    Combinando habitat y caracterizacion biologica: validacion ecologica del "river habitat survey"

    Get PDF
    The River Habitat Survey (RHS) is a widespread technique used to characterize the habitats at the fluvial sector level and to quantify the magnitude of physical disturbances. In this study we tested the ability of this method to discriminate sites along a gradient of perturbation and to analyse its relation with typological and environmental features. At the same time, a biological validation of RHS parameters was carried out by crossing the descriptors with three different aquatic communities (benthic macroinvertebrates, fish, and macrophytes). The Portuguese sector of the Douro basin was the area selected for this purposes. Ordination and classification techniques were used to achieve the objectives mentioned, after a reduction of the variables as a function of their relationships and according to their affinity. The multivariate analysis revealed that the variables associated with the river corridor were more appropriate to differentiate the sampling stations along the gradient of disturbance. However, these variables, together with the ones describing the river conditions (together with the RHS derived indices) were strongly dependent on the typological characteristics. This work shows an adequate strategy for the characterization of the fluvial habitat with biological data to obtain an integrated ecological vision

    Azorean freshwater invertebrates : status, threats and biogeographic notes

    Get PDF
    This paper presents an updated catalogue of the freshwater invertebrates of the Azores archipelago and reviews the published records to account for the current taxonomic status and changes in the nomenclature of the listed taxa. The number of freshwater invertebrate species that has been recorded in the Azores has risen sharply throughout the 20th century to 241 species based on field collections and the identification by several generations of local and foreign researchers. The freshwater fauna has been described as the following: (i) being "disharmonic", i.e., lacking taxa commonly found in continental freshwater systems such as the Plecoptera, and (ii) possessing a relatively high degree of endemism in selected groups. As expected, most recorded invertebrates are primarily of Palaearctic origin. However, endemic species make up 11 % of the freshwater invertebrate fauna, which emphasises the unique character of Azorean freshwater habitats, the importance of conservation measures and the need to continue the study of these systems.Este artículo presenta un catalogo actualizado de los invertebrados acuáticos presentes en el Archipiélago de las Azores. La revisión de los registros publicados de estos animales dulceacuícolas se ha realizado teniendo en cuenta el estado taxonómico actual y los cambios en las nomenclaturas de las taxones listados. De todas las maneras la lista no pretende ser un catalogo definitivo, dado que nuevos registros continúan apareciendo, en particular, aquellos que pertenecen a habitats poco estudiados, como es el caso de los sistemas acuáticos dulceacuícolas de las Azores. El número de registros de especies de invertebrados de agua dulce en Azores ha sufrido un incremento importante a lo largo del siglo XX alcanzando 241 especies, que refleja los esfuerzos realizados en la recolección e identificación por parte de varias generaciones de investigadores. La fauna acuática es inarmónica faltando taxones comunes que si existen en los sistemas dulceacuícolas continentales, tal es el caso de los Plecoptera, y abundam los endemismos en otros grupos. La mayoría de invertebrados catalogados son primordialmente de origen Paleártico. Sin embargo, el porcentaje de especies endémicas es de 11 % lo que enfatiza el carácter único de estas especies de Las Azores, la importancia de su conservación y la necesidad de proseguir con un trabajo continuado

    Adapting and adopting River Habitat Survey : problems and solutions for fluvial hydromorphological assessment in Portugal

    Get PDF
    The Water Framework Directive (WFD), which established the use of hydromorphological quality elements to assess the ecological status of water bodies, has influenced the purpose and content of several European methods for characterizing physical structure and assessing habitat quality in rivers. The River Habitat Survey (RHS) is a WFD compliant method developed in the UK and follows rapid and simple survey procedures using a standardised approach to characterize the physical habitat and evaluate hydromorphological quality. In Portugal, RHS was adopted for WFD purposes due to its successful long term application across the UK and other European countries. Even so, an effort was made to adapt the RHS to Portuguese regional and river characteristics, in order to accurately record habitat features, assess habitat quality and comply with legal requirements. This paper describes the constraints, adaptations, state of the art and way forward for a successful RHS implementation in Portugal. Constraints concerning the application of RHS to Mediterranean rivers are strongly related to natural hydromorphological processes, namely annual and inter-annual flow variability, which is a potential source of covariance with anthropogenic pressures. This leads to difficulties in recognizing and accurately recording some RHS features. Adaptations to RHS were introduced for survey guidelines, recording procedures and improved definitions of habitat features. Additional modifications were prepared in different sections of RHS field form to reflect Portuguese river features and incorporate components required by the WFD.La Directiva Marco del Agua (DMA), que estableció el uso de indicadores de calidad hidromorfológicos para evaluar el estado ecológico de las masas de agua, ha influido en la finalidad y el contenido de varios métodos europeos para la caracterización de la estructura física y la evaluación de la calidad del h'abitat en los ríos. El River Habitat Survey (RHS) es un método compatible con la DMA desarrollado en el Reino Unido y sigue los procedimientos de encuesta rápida y sencilla utilizando un método estándar para caracterizar el hábitat físico y evaluar la calidad hidromorfológa. En Portugal, el RHS fue adoptado a efectos de la DMA debido a su exitosa aplicación a largo plazo en el Reino Unido y otros países europeos. Aun así, se hizo un esfuerzo para adaptar el RHS a las características regionales y de los ríos de Portugal, con el fin de registrar con precisión las características del hábitat, evaluar la calidad del hábitat y cumplir con los requisitos legales. Este artículo describe las limitaciones, las adaptaciones, el estado de implementacion y la manera para una implementación exitosa de RHS en Portugal. Las restricciones relativas a la aplicación de RHS a los ríos del Mediterráneo están fuertemente relacionadas con procesos hidromorfológicos naturales, como es la variabilidad del flujo anual e interanual, la cual es una fuente potencial de covarianza con presiones antropogénicas. Esto lleva a dificultades para reconocer y registrar con precisión algunas de las caracter'ısticas del RHS. Se han introducido adaptaciones al RHS en las directrices de muestreo, en los procedimientos de registro y se han mejorado algunas definiciones de ciertas características del hábitat. Otras modificaciones adicionales se han realizado en diferentes secciones del formulario de campo del RHS para reflejar las características de los ríos por tugueses y ciertas componentes requeridas por la DMA

    Effects of landscape metrics and land-use variables on macroinvertebrate communities and habitat characteristics

    Get PDF
    The growing number of studies establishing links between stream biota, environmental factors and river classification has contributed to a better understanding of fluvial ecosystem function. Environmental factors influencing river systems are distributed over hierarchically organised spatial scales. We used a nested hierarchical sampling design across four catchments to assess how benthic macroinvertebrate community composition and lower spatial scale habitat descriptors were shaped by landscape and land-use patterns. We found that benthic macroinvertebrate community structure and composition varied significantly from catchment to habitat level. We assessed and identified fractal metrics of landscape descriptors capable of explaining compositional and functional change in the benthic faunal indicators and compared them with the traditional variables describing land use and reach level habitat descriptors within a 1 km radius of each sampling site. We found that fractal landscape metrics were the best predictor variables for benthic macroinvertebrate community composition, function, instream habitat and river corridor characteristics.El creciente número de estudios que relacionan la biota fluvial, los factores ambientales y la clasificación de los ríos, ha contribuido a comprender el funcionamiento de los ecosistemas fluviales. La organización de los factores ambientales fluviales es entendida, en la actualidad, como una jerarquía de factores con varias escalas espaciales. Para evaluar cómo la composición de los macroinvertebrados bentónicos y las características del hábitat a escala local son afectadas por el uso del paisaje y del suelo, se siguió un diseño de muestreo jerárquico en cuatro cuencas. Hemos verificado que la estructura y composición de las comunidades de macroinvertebrados bentónicos varió significativamente desde la escala de cuenca hasta la del hábitat. Fueron evaluadas e identificadas métricas fractales del paisaje que podrían explicar los cambios en la composición y funcionalidad de la fauna bentónica y se ha comparado también con la influencia de las tradicionales variables de usos del suelo y descriptores del hábitat al nivel del tramo, en un círculo de 1 km de radio alrededor de cada tramo. Encontramos que las métricas fractales del paisaje fueron las mejores variables predictoras de la composición y funcionalidad de las comunidades de macroinvertebrados y de las características del hábitat en el cauce y del corredor fluvial

    The candidate TB vaccine, MVA85A, induces highly durable Th1 responses

    Get PDF
    BACKGROUND: Vaccination against tuberculosis (TB) should provide long-term protective immunity against Mycobacterium tuberculosis ( M.tb ). The current TB vaccine, Bacille Calmette-Guerin (BCG), protects against disseminated childhood TB, but protection against lung TB in adolescents and adults is variable and mostly poor. One potential reason for the limited durability of protection may be waning of immunity through gradual attrition of BCG-induced T cells. We determined if a MVA85A viral-vector boost could enhance the durability of mycobacteria-specific T cell responses above those induced by BCG alone. METHODS: We describe a long-term follow-up study of persons previously vaccinated with MVA85A. We performed a medical history and clinical examination, a tuberculin skin test and measured vaccine-specific T cell responses in persons previously enrolled as adults, adolescents, children or infants into three different Phase II trials, between 2005 and 2011. RESULTS: Of 252 potential participants, 183 (72.6%) consented and completed the study visit. Vaccine-induced Ag85A-specific CD4+ T cell responses were remarkably persistent in healthy, HIV-uninfected adults, adolescents, children and infants, up to 6 years after MVA85A vaccination. Specific CD4+ T cells expressed surface markers consistent with either CD45RA−CCR7+ central memory or CD45RA−CCR7− effector memory T cells. Similarly durable Ag85A-specific CD4+ T cell responses were detected in HIV-infected persons who were on successful antiretroviral therapy when MVA85A was administered. By contrast, Ag85A-specific CD4+ T cell frequencies in untreated MVA85A-vaccinated HIV-infected persons were mostly undetectable 3-5 years after vaccination. CONCLUSION: MVA85A induces remarkably durable T cell responses in immunocompetent persons. However, results from a recent phase IIb trial of MVA85A, conducted in infants from the same geographic area and study population, showed no vaccine efficacy, suggesting that these durable T cell responses do not enhance BCG-induced protection against TB in infants

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

    Get PDF
    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

    Glastir Monitoring & Evaluation Programme. First year annual report

    Get PDF
    The Welsh Government has commissioned a comprehensive new ecosystem monitoring and evaluation programme to monitor the effects of Glastir, its new land management scheme, and to monitor progress towards a range of international biodiversity and environmental targets. A random sample of 1 km squares stratified by landcover types will be used both to monitor change at a national level in the wider countryside and to provide a backdrop against which intervention measures are assessed using a second sample of 1 km squares located in areas eligible for enhanced payments for advanced interventions. Modelling in the first year has forecast change based on current understanding, whilst a rolling national monitoring programme based on an ecosystem approach will provide an evidence-base for on-going, adaptive development of the scheme by Welsh Government. To our knowledge, this will constitute the largest and most in-depth ecosystem monitoring and evaluation programme of any member state of the European Union

    Structural and non-coding variants increase the diagnostic yield of clinical whole genome sequencing for rare diseases

    Get PDF
    Background Whole genome sequencing is increasingly being used for the diagnosis of patients with rare diseases. However, the diagnostic yields of many studies, particularly those conducted in a healthcare setting, are often disappointingly low, at 25–30%. This is in part because although entire genomes are sequenced, analysis is often confined to in silico gene panels or coding regions of the genome. Methods We undertook WGS on a cohort of 122 unrelated rare disease patients and their relatives (300 genomes) who had been pre-screened by gene panels or arrays. Patients were recruited from a broad spectrum of clinical specialties. We applied a bioinformatics pipeline that would allow comprehensive analysis of all variant types. We combined established bioinformatics tools for phenotypic and genomic analysis with our novel algorithms (SVRare, ALTSPLICE and GREEN-DB) to detect and annotate structural, splice site and non-coding variants. Results Our diagnostic yield was 43/122 cases (35%), although 47/122 cases (39%) were considered solved when considering novel candidate genes with supporting functional data into account. Structural, splice site and deep intronic variants contributed to 20/47 (43%) of our solved cases. Five genes that are novel, or were novel at the time of discovery, were identified, whilst a further three genes are putative novel disease genes with evidence of causality. We identified variants of uncertain significance in a further fourteen candidate genes. The phenotypic spectrum associated with RMND1 was expanded to include polymicrogyria. Two patients with secondary findings in FBN1 and KCNQ1 were confirmed to have previously unidentified Marfan and long QT syndromes, respectively, and were referred for further clinical interventions. Clinical diagnoses were changed in six patients and treatment adjustments made for eight individuals, which for five patients was considered life-saving. Conclusions Genome sequencing is increasingly being considered as a first-line genetic test in routine clinical settings and can make a substantial contribution to rapidly identifying a causal aetiology for many patients, shortening their diagnostic odyssey. We have demonstrated that structural, splice site and intronic variants make a significant contribution to diagnostic yield and that comprehensive analysis of the entire genome is essential to maximise the value of clinical genome sequencing
    corecore