11 research outputs found

    Bar-tailed Godwits Limosa l. lapponica eat polychaete worms wherever they winter in Europe

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    <p>Capsule Across the European wintering range Bar-tailed Godwits Limosa lapponica lapponica selected polychaete worms and especially Ragworms Hediste diversicolor, with differences between areas due to variations in prey availability.Aims To determine the diet of Bar-tailed Godwits across their wintering range in Europe by the analysis of droppings, collected at five important wintering sites.Methods Diet was estimated by the identification of undigested prey remains in droppings. We provide the rationale for quantifying the contributions of jawed and non-jawed polychaetes.Results We identified 18 different prey species in the diet of wintering Bar-tailed Godwits. The Ragworm was the most common prey item and the only one actively selected. Ragworms, on average, contributed 79% to the diet in terms of biomass, followed by King Ragworm Alitta virens (with 17% biomass) and Lugworms Arenicola marina (with 2%). Polychaetes such as Alitta succinea and Scoloplos armiger were also regularly found in the diet. Bivalves, snails and crustaceans contributed less than 1% to the diet.Conclusion This study highlights and confirms the importance of polychaete worms in the diet of European-wintering Bar-tailed Godwits.</p>

    Fungos endofíticos em Annona spp.: isolamento, caracterização enzimática e promoção do crescimento em mudas de pinha (Annona squamosa L.) Endophytic fungi of Annona spp.: isolation, enzymatic characterization of isolates and plant growth promotion in Annona squamosa L. seedlings

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    A partir de folhas, caules e raízes de plantas de pinha e graviola coletadas em Pernambuco foram obtidos 110 e 90 isolados fúngicos endofíticos, respectivamente. Vinte e nove isolados foram selecionados e avaliados quanto à produção de enzimas extracelulares, através do método qualitativo em placas com meios sólidos específicos, e à capacidade de estimular o crescimento de mudas de pinha. Esses isolados foram identificados como pertencentes aos gêneros Acremonium (10,34%), Aspergillus (3,45%), Chaetomium (3,45%), Colletotrichum (10,34%), Cylindrocladium (13,8%), Fusarium (31,03%), Glomerella (3,45%), Nigrospora (6,9%), Penicillium (6,9%) e Phomopsis (10,34%). Dezenove isolados apresentaram atividade lipolítica, cinco atividade proteolítica e nenhum deles atividades celulolítica ou amilolítica. Onze isolados dos gêneros Acremonium (GFR6 e GRR1), Colletotrichum (GFR4 e PFR4), Phomopsis (PFR3 e GCR4), Cylindrocladium (GRR4), Chaetomium (GRR7) e Fusarium (GRR5, PRR1 e PRR6) promoveram eficientemente o crescimento vegetal. Os índices de aumento da biomassa seca da parte aérea de mudas de pinha variou de 23,2 a 32,7%, sendo que nenhum isolado promoveu a biomassa seca da raiz. Destaca-se também que 20 isolados apresentaram efeito deletério significativo (P = 0,05) na biomassa seca da raiz das mudas de pinha. Em tecidos aparentemente sadios de plantas de pinha e graviola são encontrados alguns fungos que podem promover o crescimento da parte aérea, como também reduzir o crescimento da raiz e outros sem efeito no crescimento de mudas de pinha.<br>Endophytic isolates of fungi were obtained from leaves, stems and roots of 110 sweetsop and 90 soursop plants from Pernambuco. Twenty-nine isolates were analyzed for production of extracellular enzymes by qualitative assay in Petri dishes containing specific solid media, and for the capacity to promote growth of sweetsop seedlings. These isolates were identified as Acremonium (10.34%), Aspergillus (3.45%), Chaetomium (3.45%), Colletotrichum (10.34%), Cylindrocladium (13.8%), Fusarium (31.03%), Glomerella (3.45%), Nigrospora (6.9%), Penicillium (6.9%) and Phomopsis (10.34%). Nineteen isolates showed lypolytic activity while five showed proteolytic activity; cellulolytic and amylolytic activity were not detected. Eleven isolates of the genera Acremonium (GFR6 and GRR1), Colletotrichum (GFR4 and PFR4), Phomopsis (PFR3 and GCR4), Cylindrocladium (GRR4), Chaetomium (GRR7) and Fusarium (GRR5, PRR1 and PRR6) efficiently improved plant growth. Increase in shoot dry matter of sweetsop seedlings ranged from 23.2 to 32.7%; there was no increase in root dry matter. It is worthy of note that 20 isolates caused significant (P = 0.05) reduction in root dry matter of sweetsop seedlings. In apparently healthy tissues of sweetsop and soursop plants, some fungi promote shoot growth or reduce root growth, while others have no effect on growth of sweetsop seedlings

    Three new VHS–DES quasars at 6.7 < z < 6.9 and emission line properties at z > 6.5

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    International audienceWe report the results from a search for z > 6.5 quasars using the Dark Energy Survey (DES) Year 3 data set combined with the VISTA Hemisphere Survey (VHS) and WISE All-Sky Survey. Our photometric selection method is shown to be highly efficient in identifying clean samples of high-redshift quasars, leading to spectroscopic confirmation of three new quasars – VDES J0244−5008 (z = 6.724), VDES J0020−3653 (z = 6.834), and VDES J0246−5219 (z = 6.90) – which were selected as the highest priority candidates in the survey data without any need for additional follow-up observations. We have obtained spectroscopic observations in the near-infrared for VDES J0244−5008 and VDES J0020−3653 as well as our previously identified quasar, VDES J0224−4711 at z = 6.50 from Reed et al. We use the near-infrared spectra to derive virial black hole masses from the full width at half-maximum of the Mg ii line. These black hole masses are ≃1–2 × 10^9 M_⊙. Combined with the bolometric luminosities of these quasars of L_bol ≃ 1–3 × 10^47, these imply that the Eddington ratios are high, ≃0.6–1.1. We consider the C iv emission line properties of the sample and demonstrate that our high-redshift quasars do not have unusual C iv line properties when compared to carefully matched low-redshift samples. Our new DES + VHS z > 6.5 quasars now add to the growing census of luminous, rapidly accreting supermassive black holes seen well into the epoch of reionization
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