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showing 10 items of 8047 documents
Ecophysiological Modeling of Grapevine Water Stress in Burgundy Terroirs by a Machine-Learning Approach
2016
13 pages; International audience; In a climate change scenario, successful modeling of the relationships between plant-soil-meteorology is crucial for a sustainable agricultural production, especially for perennial crops. Grapevines (Vitis vinifera L. cv Chardonnay) located in eight experimental plots (Burgundy, France) along a hillslope were monitored weekly for 3 years for leaf water potentials, both at predawn (Ψpd) and at midday (Ψstem). The water stress experienced by grapevine was modeled as a function of meteorological data (minimum and maximum temperature, rainfall) and soil characteristics (soil texture, gravel content, slope) by a gradient boosting machine. Model performance was a…
A manipulative parasite increasing an antipredator response decreases its vulnerability to a nonhost predator.
2009
8 pages; International audience; Trophically transmitted parasites have to deal with the antipredator adaptations of their intermediate hosts. Some of these parasites induce behavioural changes in their intermediate hosts that make them more vulnerable to predation by definitive hosts. However, the adaptiveness of behavioural manipulation also depends on the probability of being eaten by a nonhost predator. Parasites might therefore try to use specific antipredator responses of intermediate hosts to avoid this dead end. We tested this hypothesis using the acanthocephalan Polymorphus minutus and its intermediate amphipod host, Gammarus roeseli. In their natural habitat, uninfected G. roeseli…
A new rationale for not picking low hanging fruits: The separation of ownership and control
2019
Recent attempts at explaining the energy-efficiency gap rely on considerations related to organizational and behavioral/cognitive failures. In this paper, we build on the strategic delegation literature to advance a complementary explanation. It is shown that strategic market interaction may encourage business owners to instill a bias against energy efficiency in managerial compensation contracts. Since managers respond to financial incentives, their decisions will reflect this bias, resulting in lack of investment.
Limits and targets for a regional sustainability assessment: an interdisciplinary exploration of the threshold concept
2008
Part 5. Regional and local evaluation-18 ; International audience; Some encompassing terminology is required in order to accommodate different conceptual approaches in the three pillars of sustainability. So, this chapter provides a literature review exploring the threshold concept. In environmental research – especially in ecology – thresholds are often associated with limits which have certain system-inherent processes. In social and economic disciplines, if the notion of limit or critical limit is present, the concept of targets is often more appropriate which are linked to political objectives and social acceptability. The concept of threshold is accommodated within the general framewor…
Acoustic communication in the Kittiwake Rissa tridactyla: potential cues for sexual and individual signatures in long calls
2007
International audience; Sex and individual recognition systems vary among species and can have various functions in different contexts. In order to determine the basis of identification by voice in the Kittiwake (Rissa tridactyla), the greeting calls of 32 individuals (18 males and 14 females) were recorded in May–June 2004 on the Kittiwake colony of Hornøya island (Barents sea) and analysed. On the basis of coefficient of variation calculations and discriminant analyses, we show (1) that calls are sexually dimorphic and that the dimorphism is mainly based on the value of the fundamental frequency, and (2) that calls are individually distinct, individuality being due to a complex of tempora…
Individual dispersal status influences space use of conspecific residents in the common lizard, Lacerta vivipara
2006
The effects of immigration on the behaviour of residents may have important implications for the local population characteristics. A manipulative laboratory experiment with yearlings of the common lizard (Lacerta vivipara) was performed to test whether the introduction of dispersing or philopatric individuals influences the short-term spacing behaviour of resident individuals. Staged encounters were carried out to induce interactions within dyads. The home cage of each responding individual was connected by a corridor to an unfamiliar “arrival cage” to measure the latency to leave their own home cage after each encounter. Our results showed that the time that pairs spent in close proximity …
Variations in soil-water use by grapevine according to plant water status and soil physical-chemical characteristics - A 3D spatio-temporal analysis.
2016
14 pages; International audience; Understanding plant and soil-water relationships is crucial to optimise agricultural management. In this multidisciplinary work, soil geophysics and plant physiological measurements are coupled and a statistical method is proposed to visualising plant soil-water uptake in space and time. The method is applied in a vineyard context and shows differences in the use of tranpirable soil water by grapevine according to the type of soil and the time of the day (day/night).During two years the water stress experienced by a single Chardonnay/SO4 grapevine clone was monitored both at pre-dawn and midday by leaf water potentials in two field plots exclusively differe…
Pea Efficiency of Post-drought Recovery Relies on the Strategy to Fine-Tune Nitrogen Nutrition
2020
International audience; As drought is increasingly frequent in the context of climate change it is a major constraint for crop growth and yield. The ability of plants to maintain their yield in response to drought depends not only on their ability to tolerate drought, but also on their capacity to subsequently recover. Post-stress recovery can indeed be decisive for drought resilience and yield stability. Pea (Pisum sativum), as a legume, has the capacity to fix atmospheric nitrogen through its symbiotic interaction with soil bacteria within root nodules. Biological nitrogen fixation is highly sensitive to drought which can impact plant nitrogen nutrition and growth. Our study aimed at dyna…
Evolutionary Changes after Translational Challenges Imposed by Horizontal Gene Transfer
2019
International audience; Genes acquired by horizontal gene transfer (HGT) may provide the recipient organism with potentially new functions, but proper expression level and integration of the transferred genes in the novel environment are not granted. Notably, transferred genes can differ from the receiving genome in codon usage preferences, leading to impaired translation and reduced functionality. Here, we characterize the genomic and proteomic changes undergone during experimental evolution of Escherichia coli after HGT of three synonymous versions, presenting very different codon usage preference, of an antibiotic resistance gene. The experimental evolution was conducted with and without…
Parasite-induced suppression of aggregation under predation risk in a freshwater amphipod
2012
a b s t r a c t Recent findings suggest that grouping with conspecifics is part of the behavioural defences developed by amphipod crustaceans to face predation risk by fish. Amphipods commonly serve as intermediate hosts for trophically transmitted parasites. These parasites are known for their ability to alter intermediate host phenotype in a way that promotes predation by definitive hosts, where they reproduce. If aggregation in amphipods dilutes the risk to be preyed on by fish, then it may dilute the probability of transmission for the parasite using fish as definitive hosts. Using experimental infections, we tested whether infection with the fish acanthocephalan Pomphorhynchus laevis a…