Search results for "valu"
showing 10 items of 8713 documents
Intégrer la connectivité paysagère dans la séquence ERC : une approche par la quantité d'habitat atteignable
2019
Des engagements nationaux, européens et internationaux ont été pris pour maintenir et restaurer la connectivité entre habitats naturels face à la perte et à la fragmentation de ces habitats. Dans le même temps, les politiques environnementales dans différents pays mettent en oeuvre la séquence Eviter-Réduire-Compenser (ERC) pour atteindre l’objectif d’absence de perte nette de biodiversité (PPN). La séquence ERC a pour principe d’évaluer l’ensemble des impacts écologiques d’un aménagement, mais les critères et indicateurs permettant de quantifier les impacts sur la connectivité paysagère ne sont pas satisfaisants. Nous proposons une démarche opérationnelle pour évaluer les impacts environne…
Descriptors of Posidonia oceanica meadows: Use and application
2005
This work benefited partly from the financial support of the European program ΓNTERREG IIIA Corsica, Sardinia. Tuscany
Escaping the evolutionary trap: Can size-related contest advantage compensate for juvenile mortality disadvantage when parasitoids develop in unnatur…
2021
Abstract The quality of hosts for a parasitoid wasp may be influenced by attributes such as host size or species, with high quality for successful development usually coincident with high quality for larger offspring. This is not always the case: for the Scelionid wasp Trissolcus basalis, oviposition in eggs of the Brown Marmorated Stink Bug, Halyomorpha halys, rather than of the normal host, the Southern Green Stink Bug, Nezara viridula, leads to lower offspring survival, but survivors can be unusually large. Adult female T. basalis engage in contests for host access. As larger contestants are typically favoured in contests between parasitoids, the larger size of surviving offspring may co…
New Acyclic Cytotoxic Jasplakinolide Derivative from the Marine Sponge Jaspis splendens
2019
A new acylic jasplakinolide congener (2), another acyclic derivative requiring revision (4), together with two jasplakinolide derivatives including the parent compound jasplakinolide (1) were isolated from the Indonesian marine sponge Jaspis splendens. The chemical structures of the new and known compounds were unambiguously elucidated based on HRESIMS and exhaustive 1D and 2D NMR spectral analysis as well as a comparison of their NMR data with those of jasplakinolide (1). The isolated jasplakinolides inhibited the growth of mouse lymphoma (L5178Y) cells in vitro with IC50 values in the low micromolar to nanomolar range.
Natural colorants improved the physicochemical and sensorial properties of frozen Brazilian sausage (linguiça) with reduced nitrite
2020
Made available in DSpace on 2021-06-25T12:18:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01. Added 1 bitstream(s) on 2021-07-15T15:05:51Z : No. of bitstreams: 1 S0103-90162021000300902.pdf: 246305 bytes, checksum: 130e2a2703383287ec0721e788c1b83e (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) The use of natural colorants in meat products can keep its coloring attractive as well as meet the demand from consumers interested in products that are healthier. Nitrite is added as a preservative to these products and it is also a precursor of the generation of a specifically desired color in meat products. However, its use has been associated with the dev…
Long-term modelling of weed control strategies: analysis of threshold-based options for weed species with contrasted competitive abilities
2002
A simple life-cycle-based demography model was adapted for two contrasting weed species (Alopecurus myosuroides and Poa annual. This model included a seed production function that accounted for population self-regulation through weed:weed interactions. The A. myosuroides version of the model was tested with field data. Long-term simulations of population demography were then performed to investigate the relationship between weed control strategies based on density thresholds and both the frequency of herbicide use and the long-term economic profitability. This study confirms that threshold-based weed management strategies are more cost-effective than spraying every year and may allow import…
Communication in social insects and how it is shaped by individual experience
2019
Communication is the foundation of all social systems, and learning is perhaps the most important cognitive tool. But how do these two critical faculties interact? With social insects being some of the best learners of the invertebrate world, and indisputably the most communicative, we examine the role of learning and experience in social insect communication. Learning plays a major role for both senders and receivers. A sender's experience can modulate what information is available for communication, whether communication is effective and whether individuals are motivated to communicate. Signalling about a resource is often modulated relative to the value of that resource and relative to t…
A Systematic Literature Review of Historic Garden Management and Its Economic Aspects
2020
Historic gardens are important parts of humanity’s built heritage within the designed landscape, providing many environmental, economic and socio-cultural benefits. Management is a key part of their conservation, perhaps the most difficult because it is costly, must be continual, and requires a skilled workforce. This systematic review looks at the literature addressing historic garden management, with special attention regarding the social, economic and environmental aspects of sustainability. Academic studies on this subject come from many different disciplines, making it both stimulating and fragmented. It is now time to consolidate these interdisciplinary efforts into a clear vision, in…
The Importance of Engaging Local People in Landscape Management – Experiences from an EU Project
2018
“Bull by the Horns” -project initiated landscape management and promoted biodiversity associated with diminishing High Nature Value farmland habitats in Finland. A specific focus was on grazed semi-natural grasslands and wood-pastures which are collectively referred to as traditional rural biotopes (TRBs). Collaboration among project workers, non-farming landowners, and cattle owners reintroduced grazing to abandoned pastures, and management was financed through agri-environmental payments. Using adaptive co-management principles, the project enabled collective definition of integrated site-specific management objectives. A better understanding of contemporary challenges and opportunities t…
Variations spatiales et temporelles des communautés adventices des cultures annuelles en France
2007
Although arable weed species are particularly well adapted to habitats characterised by high levels of disturbance(ploughing, harvest), the degree and rate at which agro-ecosytems have been transformed in the last 50 years in Europe(use of chemicals, changes in crop rotations) has led to profound changes in the composition and diversity of arable weedcommunities. This thesis provides an update on the composition and diversity of weed communities that can be foundacross the main crop types and regions of France. It also addresses two objectives i) applying (community) ecologytheories for the analysis and interpretation of spatial and temporal variations in weed communities and ii) using the …