Hydrology influences breeding time in the white-throated dipper     

Nilsson  Anna L. K.  Skaugen  Thomas  Reitan  Trond  L’Abée-Lund  Jan Henning  Gamelon  Marlène  Jerstad  Kurt  Røstad  Ole Wiggo  Slagsvold  Tore  Stenseth  Nils C.  Vøllestad  L. Asbjørn  Walseng  Bjørn 《BMC ecology》2020,20(1):1-12

While nitrogen and carbon stable isotope values can reflect ecological segregation, prey choice and spatial distribution in seabirds, the interpretation of bulk stable isotope values is frequently hampered by a lack of isotopic baseline data. In this study, we used compound-specific isotope analyses of amino acids (CSIA-AA) to overcome this constraint and to study interspecific differences, seasonal and historical changes in trophic positions of five seabird species, three penguins and two petrels, from a sub-Antarctic seabird community. CSIA-AA allowed comparing trophic positions of seabirds with temperate and polar distributions. Gentoo and Magellanic penguins had the highest trophic positions during the breeding season (3.7 and 3.9), but decreased these (2.9 and 3.3) during the feed-up for moult. Intra-specific differences were also detected in Thin-billed prions, where carbon isotope values clearly separated individuals with polar and temperate distributions, both in the breeding and interbreeding periods. Thin-billed prions that foraged in polar waters had lower trophic positions (3.2) than conspecifics foraging in temperate waters (3.8). We further investigated historical changes by comparing museum samples with samples collected recently. Our pilot study suggests that Rockhopper penguins, Magellanic penguins and Thin-billed prions with temperate non-breeding distributions had retained their trophic levels over a 90–100 year period, while Gentoo penguins and Thin-billed prions with polar non-breeding distributions had decreased trophic levels compared to historical samples. In contrast, Wilson’s storm-petrels had slightly increased trophic levels compared to samples taken in 1924–1930. We applied compound-specific stable isotope analyses across a range of contexts, from intra-specific comparisons between stages of the breeding cycle to inter-specific seabird community analysis that would not have been possible using bulk stable isotope analyses alone due to differences in isotopic baselines.  相似文献   

Toward the Identification of Novel Antimicrobial Agents: One-Pot Synthesis of Lipophilic Conjugates of N-Alkyl d- and l-Iminosugars     

Anna Esposito  Daniele D&#x;Alonzo  Stefano D&#x;Errico  Eliana De Gregorio  Annalisa Guaragna 《Marine drugs》2020,18(11)

In the effort to improve the antimicrobial activity of iminosugars, we report the synthesis of lipophilic iminosugars 10a–b and 11a–b based on the one-pot conjugation of both enantiomeric forms of N-butyldeoxynojirimycin (NBDNJ) and N-nonyloxypentyldeoxynojirimycin (NPDNJ) with cholesterol and a succinic acid model linker. The conjugation reaction was tuned using the established PS-TPP/I₂/ImH activating system, which provided the desired compounds in high yields (94–96%) by a one-pot procedure. The substantial increase in the lipophilicity of 10a–b and 11a–b is supposed to improve internalization within the bacterial cell, thereby potentially leading to enhanced antimicrobial properties. However, assays are currently hampered by solubility problems; therefore, alternative administration strategies will need to be devised.  相似文献   

Constructing sustained‐release herbicide formulations based on poly‐3‐hydroxybutyrate and natural materials as a degradable matrix     

Evgeniy G Kiselev  Anatoly N Boyandin  Natalia O Zhila  Svetlana V Prudnikova  Anna A Shumilova  Sergey V Baranovskiy  Ekaterina I Shishatskaya  Sabu Thomas  Tatiana G Volova 《Pest management science》2020,76(5):1772-1785

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Water availability affects nectar sugar production and insect visitation of the cup plant Silphium perfoliatum L. (Asteraceae)     

Anna Lena Mueller  Christian A. Berger  Siegfried Schittenhelm  Burkhard Stever-Schoo  Jens Dauber 《Journal of Agronomy and Crop Science》2020,206(5):529-537

The perennial cup plant (Silphium perfoliatum L.) is considered as an alternative feedstock to maize for biogas plants. Due to its ecological advantages of an extensive management and function as food resource for pollinators, it can be grown in Ecological Focus Areas (EFAs) since 2018. However, studies at the Julius Kühn-Institute in Braunschweig (Germany) showed that the assumed advantage of the cup plant of a high drought tolerance could not be confirmed regarding aspects of crop production and yield. We complemented this experiment by assessing how different soil moisture conditions affect the production of floral resources and insect visitation. In 2014, we sampled three irrigated and three rainfed plots of the cup plant. We quantified the nectar volume and sugar mass per inflorescence, the number of inflorescences per plant and calculated the total nectar sugar production. We further counted insect visitation on the inflorescences. Due to reduced numbers of inflorescences per plant and an earlier harvest, the estimated nectar sugar production was 58 kg/ha regarding irrigated and 20 kg/ha regarding rainfed plots. Honeybee visitation per inflorescence was about twice as high in the irrigated plots. Furthermore, the early harvest is a disadvantage for wild pollinators with a late activity period.  相似文献   

Clinical and magnetic resonance imaging features of lymphoma involving the nervous system in cats     

Alexane Durand  Erin Keenihan  Daniela Schweizer  Arianna Maiolini  Julien Guevar  Anna Oevermann  Rodrigo Gutierrez&#x;Quintana 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2022,36(2):679

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Effects of no‐take area size and age of marine protected areas on fisheries yields: a meta‐analytical approach     

Frederic Vandeperre  Ruth M. Higgins  Julio Sánchez‐Meca  Francesc Maynou  Raquel Goñi  Pablo Martín‐Sosa  Angel Pérez‐Ruzafa  Pedro Afonso  Iacopo Bertocci  Romain Crec’hriou  Giovanni D’Anna  Mark Dimech  Carmelo Dorta  Oscar Esparza  Jesús M. Falcón  Aitor Forcada  Ivan Guala  Laurence Le Direach  Concepción Marcos  Celia Ojeda‐Martínez  Carlo Pipitone  Patrick J. Schembri  Vanessa Stelzenmüller  Ben Stobart  Ricardo S. Santos 《Fish and Fisheries》2011,12(4):412-426

Marine protected areas (MPAs) are often promoted as tools for biodiversity conservation as well as for fisheries management. Despite increasing evidence of their usefulness, questions remain regarding the optimal design of MPAs, in particular concerning their function as fisheries management tools, for which empirical studies are still lacking. Using 28 data sets from seven MPAs in Southern Europe, we developed a meta‐analytical approach to investigate the effects of protection on adjacent fisheries and asking how these effects are influenced by MPA size and age. Southern European MPAs showed clear effects on the surrounding fisheries, on the ‘catch per unit effort’ (CPUE) of target species, but especially on the CPUE of the marketable catch. These effects depended on the time of protection and on the size of the no‐take area. CPUE of both target species and the marketable catch increased gradually by 2–4% per year over a long time period (at least 30 years). The influence of the size of the no‐take area appeared to be more complex. The catch rates of the entire fishery in and around the MPA were higher when the no‐take areas were smaller. Conversely, catch rates of selected fisheries that were expected to benefit most from protection increased when the no‐take area was larger. Our results emphasize the importance of MPA size on its export functions and suggest that an adequate, often extended, time frame be used for the management and the evaluation of effectiveness of MPAs.  相似文献   

Detection and characterization of a rhabdovirus causing mortality in black bullhead catfish,Ameiurus melas          下载免费PDF全文

Giulia Bedendo  Valentina Panzarin  Andrea Fortin  Gianpiero Zamperin  Tobia Pretto  Alessandra Buratin  Rosita Quartesan  Matteo Sabbion  Cristian Salogni  Francesco Pascoli  Anna Toffan 《Journal of fish diseases》2018,41(7):1063-1075

This study fully describes a severe disease outbreak occurred in 2016 in black bullhead catfish farmed in Italy. Affected fish showed nervous clinical signs as well as emaciations and haemorrhagic petechiae on the skin at the fin bases, abdomen and gills. Viral isolation in cell culture allowed the subsequent identification of a rhabdovirus, tentatively named ictalurid rhabdovirus (IcRV), through electron microscopy, immunofluorescence and whole genome sequencing (WGS). The newly isolated virus, together with 14 additional viral strains stored in our repository and detected during similar mortality episodes in the period 1993–2016, was phylogenetically analysed on the basis of the nucleoprotein and the glycoprotein nucleotide and amino acid sequences. The genetic distances among Italian IcRV strains were also estimated. Our results show that all the IcRV strains belong to the genus Sprivivirus and are closely related to the tench rhabdovirus (TenRV). Italian catfish production is constantly decreasing, mainly due to viral infections, which include the newly characterized IcRV. Data presented in this work will assist to investigate the molecular epidemiology and the diffusive dynamics of this virus and to develop adequate surveillance activities.  相似文献   

Population structure,residency patterns and movements of whale sharks in Southern Leyte,Philippines: results from dedicated photo‐ID and citizen science          下载免费PDF全文

Gonzalo Araujo  Sally Snow  Catherine Lee So  Jessica Labaja  Ryan Murray  Anna Colucci  Alessandro Ponzo 《水产资源保护:海洋与淡水生态系统》2017,27(1):237-252

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Strip-till as a means of decreasing spatial variability of winter barley within a field scale     

Iwona Jaskulska  Anna Gałązka 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2019,69(6):516-527

The tillage system, which joins soil tillage, fertilisation, and seed sowing in one pass of a machine, is rarely used in cereal cultivation. This research aimed to study whether strip-till and conventional tillage (post-harvest ripping and mixing of stubble, ploughing, pre-sowing fertilisation, and seedbed preparation) differ in plant density, yield components, and grain yield of winter barley cultivated on Cambisol in a region with low rainfall, the annual average is about 500?mm. To reach this aim, a two-year, large-plot experiment was conducted in a production field. The soil within the field was spatially variable in texture, moisture, and chemical and biological properties, CV 2.3% do 29.6%. Strip-till had lower within-field spatial variability of winter barley grain yield than conventional tillage. The standard deviation was 0.36?t?ha^?1, 0.67?t?ha^?1 in the first year and 0.12?t?ha^?1, 0.30?t?ha^?1 in the second year, respectively. During the period of limited rainfall, strip-till had greater uniformity of plants after emergence; after the winter with low air temperature and a low amount of snow, it had greater plant density. Thus, strip-till can reduce variability of plants and their yield within a field, especially in adverse environmental conditions.  相似文献   

Cover crop and plant density in seed production of white clover (Trifolium repens L.)     

Anna Karina R. Schmidt 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2017,67(5):416-424

Seed crops of white clover (Trifolium repens L.) are usually established with a cover crop. Provided sufficient light, white clover may compensate for low plant density by stoloniferous growth. Our objectives were (1) to compare spring barley or spring wheat used as cover crops for white clover and (2) to find the optimal seeding rate/row distance for white clover. Seven field trials were conducted in Southeast Norway from 2000 to 2003. Barley was seeded at 360 and 240 seeds m^?2 and wheat at 525 and 350 seeds m^?2. White clover was seeded perpendicularly to the cover crop at 400 seeds m^?2/13 cm row distance or 200 seeds m^?2/26 cm. Results showed that light penetration in spring and early summer was better in wheat than in barley. On average for seven trials, this resulted in 11% higher seed yield after establishment in wheat than in barley. The 33% reduction in cover crop seeding rate had no effect on white clover seed yield for any of the cover crops. Reducing the seeding rate/doubling the row distance of white clover had no effect on seed yield but resulted in slightly earlier maturation of the seed crop.  相似文献