Antileishmanial and antifungal activities of xanthanolides isolated from Xanthium macrocarpum

Seven xanthanolides, xanthinosin, xanthatin, 4-hydroxyxanthinosin, xanthinin, 4-epiisoxanthanol, 4-epixanthanol, 2-hydroxyxanthinosin and 4-oxobedfordia acid, were isolated from the fruits of Xanthium macrocarpum. A valuation of the antifungal activity of these xanthanolides against Candida albicans, Candida glabrata and Aspergillus fumigatus and of their antileishmanial activity against Leishmania infantum and Leishmania mexicana is presented.     

Light propagation with phase discontinuities: generalized laws of reflection and refraction

Conventional optical components rely on gradual phase shifts accumulated during light propagation to shape light beams. New degrees of freedom are attained by introducing abrupt phase changes over the scale of the wavelength. A two-dimensional array of optical resonators with spatially varying phase response and subwavelength separation can imprint such phase discontinuities on propagating light as it traverses the interface between two media. Anomalous reflection and refraction phenomena are observed in this regime in optically thin arrays of metallic antennas on silicon with a linear phase variation along the interface, which are in excellent agreement with generalized laws derived from Fermat's principle. Phase discontinuities provide great flexibility in the design of light beams, as illustrated by the generation of optical vortices through use of planar designer metallic interfaces.     

Protective and curative efficacy of prothioconazole against isolates of Mycosphaerella graminicola differing in their in vitro sensitivity to DMI fungicides

BACKGROUND: Septoria leaf blotch is the most important disease of wheat in Europe. To control this disease, fungicides of the 14α‐demethylase inhibitor group (DMIs) have been widely used for more than 20 years. However, resistance towards DMIs has increased rather quickly in recent years. The objective of this study was to evaluate, on plants and under controlled conditions, the protective and curative efficacy of the DMI fungicide prothioconazole against three current isolates of M. graminicola, chosen to belong to different DMI‐resistant phenotypes. Fungicide efficacy was assessed by visual symptoms and by quantitative real‐time polymerase chain reaction (PCR). RESULTS: With a protective fungicide application, prothioconazole was always effective against each isolate. This was in accordance with the EC₅₀ results. However, curative efficacy differed between the isolates. It remained at a good level, between 60 and 70% against one isolate, whereas it was strongly affected by late applications from 7 days post‐inoculation with the two other isolates. CONCLUSION: A protective application of prothioconazole in wheat crops could be the best strategy to keep a high efficacy against Septoria leaf blotch. Copyright © 2011 Society of Chemical Industry     

Effort rights‐based management

Effort rights‐based fisheries management (RBM) is less widely used than catch rights, whether for groups or individuals. Because RBM on catch or effort necessarily requires a total allowable catch (TAC) or total allowable effort (TAE), RBM is discussed in conjunction with issues in assessing fish populations and providing TACs or TAEs. Both approaches have advantages and disadvantages, and there are trade‐offs between the two approaches. In a narrow economic sense, catch rights are superior because of the type of incentives created, but once the costs of research to improve stock assessments and the associated risks of determining the TAC and costs of monitoring, control, surveillance and enforcement are taken into consideration, the choice between catch or effort RBM becomes more complex and less clear. The results will be case specific. Hybrid systems based on both catch and effort are increasingly employed to manage marine fisheries to capture the advantages of both approaches. In hybrid systems, catch or effort RBM dominates and controls on the other supplements. RBM using either catch or effort by itself addresses only the target species stock externality and not the remaining externalities associated with by‐catch and the ecosystem.     

Immunological reversal of autoimmune diabetes without hematopoietic replacement of beta cells

Type 1 diabetes mellitus results from the autoimmune destruction of the beta cells of the pancreatic islets of Langerhans and is recapitulated in the nonobese diabetic strain of mice. In an attempt to rescue islet loss, diabetic mice were made normoglycemic by islet transplantation and immunization with Freund's complete adjuvant along with multiple injections of allogeneic male splenocytes. This treatment allowed for survival of transplanted islets and recovery of endogenous beta cell function in a proportion of mice, but with no evidence for allogeneic splenocyte-derived differentiation of new islet beta cells. Control of the autoimmune disease at a crucial time in diabetogenesis can result in recovery of beta cell function.     

Does upwelling intensity determine larval fish habitats in upwelling ecosystems? The case of Senegal and Mauritania

European sardine (Sardina pilchardus) and round sardinella (Sardinella aurita) comprise two‐thirds of total landings of small pelagic fishes in the Canary Current Eastern Boundary Ecosystem (CCEBE). Their spawning habitat is the continental shelf where upwelling is responsible for high productivity. While upwelling intensity is predicted to change through ocean warming, the effects of upwelling intensity on larval fish habitat expansion is not well understood. Larval habitat characteristics of both species were investigated during different upwelling intensity regimes. Three surveys were carried out to sample fish larvae during cold (permanent upwelling) and warm (low upwelling) seasons along the southern coastal upwelling area of the CCEBE (13°–22.5°N). Sardina pilchardus larvae were observed in areas of strong upwelling during both seasons. Larval habitat expansion was restricted from 22.5°N to 17.5°N during cold seasons and to 22.5°N during the warm season. Sardinella aurita larvae were observed from 13°N to 15°N during cold seasons and 16–21°N in the warm season under low upwelling conditions. Generalized additive models predicted upwelling intensity driven larval fish abundance patterns. Observations and modeling revealed species‐specific spawning times and locations, that resulted in a niche partitioning allowing species' co‐existence. Alterations in upwelling intensity may have drastic effects on the spawning behavior, larval survival, and probably recruitment success of a species. The results enable insights into the spawning behavior of major small pelagic fish species in the CCEBE. Understanding biological responses to physical variability are essential in managing marine resources under changing climate conditions.     

A decision support tool for response to global change in marine systems: the IMBER‐ADApT Framework

Global change is occurring now, often with consequences far beyond those anticipated. Although there is a wide range of assessment approaches available to address‐specific aspects of global change, there is currently no framework to identify what governance responses have worked and where, what has facilitated change and what preventative options are possible. To respond to this need, we present an integrated assessment framework that builds on knowledge learned from past experience of responses to global change in marine systems, to enable decision‐makers, researchers, managers and local stakeholders to: (i) make decisions efficiently; (ii) triage and improve their responses; and (iii) evaluate where to most effectively allocate resources to reduce vulnerability and enhance resilience of coastal people. This integrated assessment framework, IMBER‐ADApT is intended to enable and enhance decision‐making through the development, a typology of case‐studies providing lessons on how the natural, social and governance systems respond to the challenges of global change. The typology is developed from a database of case‐studies detailing the systems affected by change, responses to change and, critically, an appraisal of these responses, generating knowledge‐based solutions that can be applied to other comparable situations. Fisheries, which suffer from multiple pressures, are the current focus of the proposed framework, but it could be applied to a wide range of global change issues. IMBER‐ADApT has the potential to contribute to timely, cost‐effective policy and governing decision‐making and response. It offers cross‐scale learning to help ameliorate, and eventually prevent, loss of livelihoods, food sources and habitat.     

Assessment of commercial and recreational fishing effects on trophic interactions in the Cap Roux area (north‐western Mediterranean)

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