Search results for "iTED"
showing 10 items of 2408 documents
Bivalve shell formation in a naturally CO2-enriched habitat: Unraveling the resilience mechanisms from elemental signatures
2018
Abstract Marine bivalves inhabiting naturally pCO2-enriched habitats can likely tolerate high levels of acidification. Consequently, elucidating the mechanisms behind such resilience can help to predict the fate of this economically and ecologically important group under near-future scenarios of CO2-driven ocean acidification. Here, we assess the effects of four environmentally realistic pCO2 levels (900, 1500, 2900 and 6600 μatm) on the shell production rate of Mya arenaria juveniles originating from a periodically pCO2-enriched habitat (Kiel Fjord, Western Baltic Sea). We find a significant decline in the rate of shell growth as pCO2 increases, but also observe unchanged shell formation r…
Simple learning rules to cope with changing environments
2008
10 pages; International audience; We consider an agent that must choose repeatedly among several actions. Each action has a certain probability of giving the agent an energy reward, and costs may be associated with switching between actions. The agent does not know which action has the highest reward probability, and the probabilities change randomly over time. We study two learning rules that have been widely used to model decision-making processes in animals-one deterministic and the other stochastic. In particular, we examine the influence of the rules' 'learning rate' on the agent's energy gain. We compare the performance of each rule with the best performance attainable when the agent …
Mutations associated with pyrethroid resistance in Varroa mite, a parasite of honey bees, are widespread across the United States.
2021
BACKGROUND Managed honey bees are key pollinators of many crops and play an essential role in the United States food production. For more than ten years, beekeepers in the United States have been reporting high rates of colony losses. One of the drivers of these losses is the parasitic mite Varroa destructor. Maintaining healthy honey bee colonies in the United States is dependent on a successful control of this mite. The pyrethroid tau-fluvalinate (Apistan®) was among the first synthetic varroacides registered in the United States. With over 20 years of use, mites resistant to Apistan® have emerged, and so it is unsurprising that treatment failures have been reported. Resistance to tau-flu…
Harvest‐induced evolution and effective population size
2016
Much has been written about fishery-induced evolution (FIE) in exploited species, but relatively little attention has been paid to the consequences for one of the most important parameters in evolutionary biology-effective population size (N-e). We use a combination of simulations of Atlantic cod populations experiencing harvest, artificial manipulation of cod life tables, and analytical methods to explore how adding harvest to natural mortality affects N-e, census size (N), and the ratio N-e/N. We show that harvest-mediated reductions in N-e are due entirely to reductions in recruitment, because increasing adult mortality actually increases the N-e/N ratio. This means that proportional red…
Dynamics of PHA-induced immune response and plasma carotenoids in birds: should we have a closer look?
2009
SUMMARY Allocation trade-offs of limited resources are thought to ensure the honesty of sexual signals and are often studied using controlled immune challenges. One such trade-off between immunity and ornaments is that involving carotenoids. Phytohemagglutinin (PHA)-induced immune response is a widely used immune challenge, yet more details on the underlying physiological mechanisms and potential costs are needed. We investigated the temporal dynamics of PHA-induced immune response and associated changes in blood carotenoids, body mass and a carotenoid-based coloured signal. We found variation in individual response patterns to PHA after peak swelling was reached, with birds showing either …
Vertebrate-mediated seed rain and artificial perches contribute to overcome seed dispersal limitation in a Mediterranean old field
2019
Natural regeneration of vegetation is a frequent outcome of land abandonment, although the rate and diversity of such regeneration may be severely restricted by seed dispersal limitation, among other factors. In spite of this, studies aiming to quantify seed rain and test methods to enhance it, such as artificial perches, are still underrepresented in the Mediterranean. In our study, we quantified seed rain density and richness and tested the effects of artificial perches on such rain over a distance gradient on seven Mediterranean island old fields. In each of the seven sites, we positioned three sampling stations, each consisting of 1 seed trap under an artificial perch and 1 as a control…
Breeding success of the Great Tit Parus major in relation to attributes of natural nest cavities in a primeval forest
2015
An overlap in attributes of nest cavities used by Great Tit Parus major across Eurasia suggests similar nest site preferences within the geographical range, although the drivers of these preferences are unclear. To determine whether preferred cavities provide conditions enhancing successful reproduction, we investigated the breeding performance of Great Tits in relation to tree cavity characteristics using data collected during 2008–2011 in primeval conditions (Białowieża National Park, Poland). Here, tree cavities are diverse and superabundant but nesting birds are at risk from a variety of predators. According to expectations, nest losses were high (60 % of Great Tit nests failed), mostly…
Implications of the EFSA Scientific Opinion on Site Directed Nucleases 1 and 2 for Risk Assessment of Genome-Edited Plants in the EU
2021
Genome editing is a set of techniques for introducing targeted changes in genomes. It may be achieved by enzymes collectively called site-directed nucleases (SDN). Site-specificity of SDNs is provided either by the DNA binding domain of the protein molecule itself or by RNA molecule(s) that direct SDN to a specific site in the genome. In contrast to transgenesis resulting in the insertion of exogenous DNA, genome editing only affects specific endogenous sequences. Therefore, multiple jurisdictions around the world have exempted certain types of genome-edited organisms from national biosafety regulations completely, or on a case-by-case basis. In the EU, however, the ruling of the Court of J…
Context-dependent coloration of prey and predator decision making in contrasting light environments
2022
A big question in behavioral ecology is what drives diversity of color signals. One possible explanation is that environmental conditions, such as light environment, may alter visual signaling of prey, which could affect predator decision-making. Here, we tested the context-dependent predator selection on prey coloration. In the first experiment, we tested detectability of artificial visual stimuli to blue tits (Cyanistes caeruleus) by manipulating stimulus luminance and chromatic context of the background. We expected the presence of the chromatic context to facilitate faster target detection. As expected, blue tits found targets on chromatic yellow background faster than on achromatic gre…
Secular trends in Dietary Inflammatory Index among adults in the United States, 1999-2014.
2018
Objective: The objective of this study was to evaluate secular trends in Dietary Inflammatory Index (DII) scores in the United States between 1999 and 2014. Methods: Data from adults over 19 years from the 1999 to 2014 National Health and Nutrition Examination Survey (N = 39,191) were used. DII scores, at each 2-year cycle, were evaluated from a 24-h recall, including 26 food parameters for DII calculation. Analyses were conducted in 2018. Results: For the entire sample, there was a quadratic trend (Ptrend < 0.001), with the DII scores peaking in 2003–2004, and then decreasing during the cycles from 2005 to 2014. Similar quadratic trends (Ptrend < 0.001) were observed by age, gender, …