329 research outputs found

    Does fishing have an impact on Maltese maerl grounds?

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    The sedimentary bottoms off the northeastern coast of the Maltese Islands are important inshore fishing grounds. Between depths of 45m and 80m, these bottoms are characterized by accumulations of unattached calcareous rhodophytes, forming maerl beds. The complex structure of these free-living thalli (rhodoliths) introduces heterogeneity to the otherwise homogenous sedimentary bottoms, thus increasing biotic diversity. Maerl deposits may take hundreds of years to accumulate and their development is strongly correlated with the current and sedimentary regimes and with bottom disturbance, making such beds susceptible to anthropogenic disruption. Two fishing techniques in particular used locally may have an impact on maerl bottoms: parit fishing (bottom-set gill-nets) and bottom trawling using an otter trawl. We investigated the effect of the former by experimental fishing on maerl, and that of the latter by studying rhodolith structure, sediment granulometry, and benthic biodiversity of a 20km2 maerl bed, part of which is regularly trawled. Parit fishing may remove the larger rhodoliths but its impact depends greatly on the strength of the bottom current. The trawled site had more abundant rhodoliths and coarser sediments than the non- trawled site, but a lower sediment organic content. Rhodolith morphology was also different at the two sites. Both sites had a high species richness but low abundance and biomass. Differences in species composition were also noted. These results are discussed in relation to the different environmental characteristics of the two sites, including the role of disturbance, but the relative importance of anthropic activities and natural perturbations is not yet clear.peer-reviewe

    PROSPECCIÓN DE HONGOS ENTOMOPATÓGENOS DEL PULGÓN DEL CIPRÉS EN DOS REGIONES ECOLÓGICAS DE CHILE. I

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    El pulgón del ciprés (Cinara cupressi), es una plaga exótica distribuida en todo el territorio continental chileno que ha provocado daños importantes tanto en especies forestales introducidas como nativas. Se han estudiado algunos aspectos de la biología de este pulgón, mediante control biológico y productos químicos, los cuales no presentan actualmente resultados satisfactorios. Durante el tiempo que esta plaga se ha establecido en Chile, no se ha realizado un estudio sistemático de hongos entomopatógenos asociados a este pulgón, aunque se cuenta con antecedentes de un control promisorio en pulgones con estos agentes en otros países. Con el objetivo inicial de aislar en una primera fase del presente estudio hongos patogénicos potenciales para el control biológico de C. cupressi, iniciamos su búsqueda en dos regiones ecológicas del sur de Chile (Región ecológica Mediterránea PerHúmeda y Región ecológica Oceánica con influencia Mediterránea), seleccionándose en cada una de ellas 6 sitios de muestreo donde en cada uno se recolectaron 10 ramas con colonias de pulgones que fueron mantenidas en una cámara bioclimática (20 ± 2 °C, 16:8 h) por 7 días,  para estimular el desarrollo fúngico. Se aislaron integrantes de lo géneros Verticillium, Paecilomyces (ambos con mayor frecuencia de presencia), Fusarium y un entomophthoral en estudio

    EVALUACIÓN DE LA VIRULENCIA DE HONGOS ENTOMOPATÓGENOS DEL PULGÓN DEL CIPRÉS, DE DOS REGIONES ECOLÓGICAS DE CHILE. II

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    El pulgón del ciprés Cinara cupressi, se considera uno de los insectos invasores más dañinos del mundo, ha provocado una gran mortalidad en especies Cupresáceas nativas y exóticas en varios países. En Chile, fue detectado el año 2003 y para el año 2008 esta plaga ya se encontraba distribuida en todo el país, afectando especies cupresáceas forestales exóticas como Cupressus macrocarpa y especies nativas, tales como, Austrocedrus chilensis (Ciprés de la Cordillera) y Fitzroya cupressoides (Alerce), que están categorizadas en el estado de conservación vulnerable y en peligro respectivamente. El área forestal de Chile ha potenciado y privilegiado el uso de controladores biológicos como parte del manejo integrado de plagas. Es por esto que se ha utilizado el parasitoide Pauesia juniperorum. Sin embargo, se han detectado bajos niveles de parasitismo. Se propone el uso de hongos entomopatógenos como alternativa y complemento al control biológico. Se prospectaron hongos entomopatógenos en la Región ecológica mediterránea per-húmeda y en la Región oceánica con influencia mediterránea. Como resultado se han identificado seis géneros de hongos descritos como patógenos de insectos. Sin embargo, bajo condiciones de laboratorio sólo cepas del género Verticillium fueron virulentas, causando sobre el 80% de mortalidad acumulada a los 7 días. No hubo diferencias significativas entre las cepas de Verticillium y un producto químico (pirimicarb) aplicado como control, aunque el hongo fue más lento. Las cepas más virulentas fueron identificadas como Verticillium lecanii, Ve 1 y Ve 2, con un TL50 de: 3.2 y 3.1 días y un DL50: 1.24 y 1.37 conidias mL-1 respectivamente, sugiriendo el uso de estos hongos para controlar C. cupressi en Chile

    First baseline data of the Klinefelter ItaliaN Group (KING) cohort: clinical features of adult with Klinefelter syndrome in Italy

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    Background Klinefelter syndrome (KS) is frustratingly under-diagnosed. KS have a broad spectrum of clinical features, making it difficult to identify. Objective We describe KS clinical presentation in a large Italian cohort. Design This is the first observational cohort study within a national network, the Klinefelter ItaliaN Group (KING). Primary outcomes were to describe the basic clinical features and the actual phenotype of KS in Italy. Secondary outcomes were to determine age at diagnosis and geographical distribution. Methods We performed a basic phenotyping and evaluation of the hormonal values of 609 adult KS patients. Results Mean age at diagnosis was 37.4 +/- 13.4 years. The overall mean testicular size was 3 ml, and 2.5 ml in both testes in untreated KS group. BMI was 26.6 +/- 5.8 kg/m(2), and 25.5% of KS had metabolic syndrome (MetS). LH and FSH were increased, and mean total testosterone were 350 +/- 9.1 ng/dl. A descriptive analysis showed that 329 KS patients were evaluated in Northern Italy, 76 in Central and 204 in Southern Italy. Analysis of variance demonstrated significant statistical differences (p < 0001) between the age at diagnosis of the three geographical groups. Compared with the expected number among male patients matched for age in Italy, only 16% of KS patients received a diagnosis. Conclusions These data are the results of the only national database available that collects the clinical and hormonal data of the KS patients, currently referred at the KING centers. In Italy the typical KS patient is overweight, with small testes, and elevated LH and FSH. Only 25.5% of them are diagnosed with MetS. Early detection and timely treatment are mandatory

    Revealing natural relationships among arbuscular mycorrhizal fungi: culture line BEG47 represents Diversispora epigaea, not Glomus versiforme

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    Background: Understanding the mechanisms underlying biological phenomena, such as evolutionarily conservative trait inheritance, is predicated on knowledge of the natural relationships among organisms. However, despite their enormous ecological significance, many of the ubiquitous soil inhabiting and plant symbiotic arbuscular mycorrhizal fungi (AMF, phylum Glomeromycota) are incorrectly classified. Methodology/Principal Findings: Here, we focused on a frequently used model AMF registered as culture BEG47. This fungus is a descendent of the ex-type culture-lineage of Glomus epigaeum, which in 1983 was synonymised with Glomus versiforme. It has since then been used as ‘G. versiforme BEG47’. We show by morphological comparisons, based on type material, collected 1860–61, of G. versiforme and on type material and living ex-type cultures of G. epigaeum, that these two AMF species cannot be conspecific, and by molecular phylogenetics that BEG47 is a member of the genus Diversispora. Conclusions: This study highlights that experimental works published during the last >25 years on an AMF named ‘G. versiforme’ or ‘BEG47’ refer to D. epigaea, a species that is actually evolutionarily separated by hundreds of millions of years from all members of the genera in the Glomerales and thus from most other commonly used AMF ‘laboratory strains’. Detailed redescriptions substantiate the renaming of G. epigaeum (BEG47) as D. epigaea, positioning it systematically in the order Diversisporales, thus enabling an evolutionary understanding of genetical, physiological, and ecological traits, relative to those of other AMF. Diversispora epigaea is widely cultured as a laboratory strain of AMF, whereas G. versiforme appears not to have been cultured nor found in the field since its original description
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