Search results for "TRADE-OFF"
showing 10 items of 131 documents
Speed-accuracy trade-off and its consequences in a scramble competition context.
2014
Abstract: Animals foraging in groups commonly respond to the presence of others by increasing their foraging rate, an increase that could come at the expense of prey detection accuracy. Yet the existence and consequences of such so-called 'speed-accuracy trade-offs' in group-foraging animals remain unexplored. We used group-feeding zebra finches, Taeniopygia guttata, to determine how search speed affects food detection accuracy and how a potential speed-accuracy trade-off influences feeding success. We found significant between-individual differences in hopping speed as well as evidence that faster individuals were more likely to overlook food, demonstrating the existence of a trade-off bet…
Sex-specific transgenerational effects of early developmental conditions in a passerine.
2007
Most studies dealing with the trade-off between offspring number and quality have overlooked the long-term consequences for the progeny. High investment in offspring number usually results in an increased competition among nest mates. The deterioration of the early developmental conditions, due to this increased competition, can impair individual quality over the long term, and subsequently affect survival and lifetime fecundity. Moreover, the consequences of the allocation rule to offspring number vs. quality can extend across generations and give raise to grandparental effects. These transgenerational trade-offs have been explored rarely. In the present study, we manipulated the breeding …
Age, pathogen exposure, but not maternal care shape offspring immunity in an insect with facultative family life
2017
International audience; Background: To optimize their resistance against pathogen infection, individuals are expected to find the right balance between investing into the immune system and other life history traits. In vertebrates, several factors were shown to critically affect the direction of this balance, such as the developmental stage of an individual, its current risk of infection and/or its access to external help such as parental care. However, the independent and/or interactive effects of these factors on immunity remain poorly studied in insects.Results: Here, we manipulated maternal presence and pathogen exposure in families of the European earwig Forficula auricularia to measur…
Introduction. Ecological immunology.
2009
12 pages; International audience; An organism's fitness is critically reliant on its immune system to provide protection against parasites and pathogens. The structure of even simple immune systems is surprisingly complex and clearly will have been moulded by the organism's ecology. The aim of this review and the theme issue is to examine the role of different ecological factors on the evolution of immunity. Here, we will provide a general framework of the field by contextualizing the main ecological factors, including interactions with parasites, other types of biotic as well as abiotic interactions, intraspecific selective constraints (life-history trade-offs, sexual selection) and popula…
Should we manage weeds for bees ?
2014
National audience
Tracking Ideal Varieties and Cropping Techniques for Agroecological Weed Management: A Simulation-Based Study on Pea.
2022
Book of abstract p.110-111; International audience; Pea (Pisum sativum L.) is a key diversification crop but current varieties are not verycompetitive against weeds. The objective of this study was to identify, depending on the typeof cropping system and weed flora, (1) the key pea parameters that drive crop production,weed control and weed contribution to biodiversity, (2) optimal combinations of peaparameter values and crop-management techniques to maximise these goals. For this, virtualexperiments were run, using FLORSYS, a mechanistic simulation model (Colbach et al., 2021,Field Crops Res 261:108006). This individual-based 3D model simulates daily crop-weed seedand plant dynamics over t…
Optimal sample allocation conditioned on a small area model, estimator, and auxiliary data
2018
We have studied optimal sample allocation, associated with small area estimation, when the objective is to obtain as accurate estimates as possible, for the population and for the subpopulations, called as areas here. It is a question of a two-level optimization problem. The basic premise is composed of planned areas, stratified sampling, and small overall sample size predetermined by restricted time and budget resources. Low sample sizes are common in market surveys. During this thesis, we have developed new allocation methods, based on a small area model, estimator, and auxiliary data. The final method, the three-term Pareto allocation, is based on the three terms of the mean-squared erro…
Managing a boreal forest landscape for providing timber, storing and sequestering carbon
2015
Human well-being highly depends on ecosystem services and this dependence is expected to increase in the future with increasing population and economic growth. Studies that investigate trade-offs between ecosystem services are urgently needed for informing policy-makers. We examine the trade-offs between a provisioning (revenues from timber selling) and regulating (carbon storage and sequestration) ecosystem services among seven alternative forest management regimes in a large boreal forest production landscape. First, we estimate the potential of the landscape to produce harvest revenues and store/sequester carbon across a 50-year time period. Then, we identify conflicts between harvest re…
What is (not) the point of just transition in food systems?
2022
Food systems are confronted with a low-carbon transition challenge. The need for significant emission reductions in industrial food systems implies significant systemic transformations in food production, processing, and consumption. The wide-reaching impacts of such transformations have evoked public discussion and academic research on just transition in food systems. The undisputable legitimacy of the idea of just transition makes it an attractive concept for all food system actors who might be affected by low-carbon transition policies in direct and indirect ways. Some of the claims that are being made are warranted claims for justice, some merely defend the achieved privileges and benef…
"Nyt nää läskit lähtee" : lihavuusleikkaukseen hakeutuminen kuluttajan ostopolkuna
2016
Tutkimuksen tavoitteena on selvittää, kuinka kuluttaja toimii hakeutuessaan vaativaan leikkaukseen. Tutkimuksessa pyritään ymmärtämään kuluttajan motivaatioita, emooti-oita ja vaikeita valintoja lihavuusleikkauksen ostopolulla. Tutkimuksen teoreettisena taustana toimivat kuluttajan ostopäätösprosessiin, erityisesti konstruktiiviseen päätös-prosessiin sekä emootioihin liittyvät teoriat ja aiempi tutkimus. Ylipainoiseen kuluttajaan, lihavuusleikkaukseen sekä terveyspalvelujen valintaan liittyvät tiedot ja teoriat muodos-tavat ostopolun maiseman. Tutkimuksessa haastateltiin 17 suomalaista kuluttajaa, joille oli suoritettu lihavuusleik-kaus. Haasteltaviksi valittiin sekä julkisen terveydenhuoll…