Search results for "EED"
showing 10 items of 5952 documents
Conifer Needles as Thermoplastic Composite Fillers: Structure and Properties
2016
This study describes the properties of thermoplastic polymer composites based on polyethylene (of low and high density) and ethylene-propylene copolymers using various types of conifer needles (pine, spruce, fir, and cedar) as fillers. For the needles, thermogravimetric analysis (TGA) and TGA/Fourier transform infrared spectroscopy (TGA/FTIR) were performed to investigate their structures and thermal resistance, as required for the composite processing methods. Moreover, structural differences were studied for the analyzed fillers and composite materials (FTIR). The results were compared with the values obtained for composites with conifer wood flour. Composites with conifer needles (pine) …
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…
Effect of vernalization on the development and growth of Alopecurus myosuroides
2002
Alopecurus myosuroides is an annual winter grass weed present in many winter and spring crops. The vernalization responses of three populations of A. myosuroides were assessed using natural exposure during winter in two field experiments and using cold exposure of imbibed seeds in a refrigerator in two greenhouse experiments. It was observed that a period of chilling during the pregermination phase had a marked effect on subsequent phenology. In the greenhouse, the major effect of vernalization was the reduction in the vegetative period because of an early reproductive induction of the apex. Plant morphology was affected by vernalization via a decrease in biomass resulting from a reduced ti…
The effect of maze complexity on maze-solving time in a desert ant
2019
One neglected aspect of research on foraging behavior is that of the effect of obstacles that increase habitat complexity on foraging efficiency. Here, we explored how long it takes individually foraging desert ant workers (Cataglyphis niger) to reach a food reward in a maze, and examined whether maze complexity affects maze-solving time (the time elapsed till the first worker reached the food reward). The test mazes differed in their complexity level, or the relative number of correct paths leading to the food reward, vs. wrong paths leading to dead-ends. Maze-solving time steeply increased with maze complexity, but was unaffected by colony size, despite the positive correlation between co…
Trans-equatorial migration routes, staging sites and wintering areas of a High-Arctic avian predator: the Long-tailed Skua (Stercorarius longicaudus).
2013
The Long-tailed Skua, a small (,300 g) Arctic-breeding predator and seabird, is a functionally very important component of the Arctic vertebrate communities in summer, but little is known about its migration and winter distribution. We used lightlevel geolocators to track the annual movements of eight adult birds breeding in north-east Greenland (n = 3) and Svalbard (n = 5). All birds wintered in the Southern Hemisphere (mean arrival-departure dates on wintering grounds: 24 October-21 March): five along the south-west coast of Africa (0–40uS, 0–15uE), in the productive Benguela upwelling, and three further south (30–40uS, 0–50uE), in an area extending into the south-west Indian Ocean. Diffe…
The antagonistic effect of UV radiation on warming or nitrate enrichment depends on ecotypes of freshwater macroalgae (Charophytes).
2019
Increases in ultraviolet radiation (UVR), a negative global change factor, affect aquatic primary producers. This effect is expected to be modulated by other global change factors, and to be different for populations adapted to different environments. A common garden experimental approach using freshwater green macroalgae, the cosmopolitan charophyte species Chara hispida and C. vulgaris, allowed us to test whether the beneficial increases in water temperature (T) and nitrate concentration (N) mitigate negative UVR effects. Also, whether these interactions would be not only species-specific but also according to the origin of the population; therefore, two populations of each species were u…
Guidance for the risk assessment of the presence at low level of genetically modified plant material in imported food and feed under Regulation (EC) …
2017
Abstract This document provides guidance for the risk assessment under Regulation (EC) No 1829/2003 of the unintended, adventitious or technically unavoidable presence in food and feed of low level of genetically modified plant material intended for markets other than in the European Union. In this context, the presence at low level is defined to be maximum 0.9% of genetically modified plant material per ingredient. This guidance is intended to assist applicants by indicating which scientific requirements of Annex II of Regulation (EU) No 503/2013 are considered necessary for the risk assessment of the presence at low levels of genetically modified plant material in food and feed.
Hierarchy of factors impacting grape berry mass: separation of direct and indirect effects on major berry metabolites
2018
Final berry mass, a major quality factor in wine production, is determined by the integrated effect of biotic and abiotic factors that can also influence berry composition. Under field conditions, interactions between these factors complicate study of the variability of berry mass and composition. Depending on the observation scale, the hierarchy of the impact degree of these factors can vary. The present work examines the simultaneous effects of the major factors influencing berry mass and composition to create a hierarchy by impact degree. A second objective was to separate the possible direct effects of factors on berry composition from an indirect effect mediated through their impact on…
Dietary characterization of Savi s Warbler Locustaella luscinioides and Great Reed Warbler Acrocephalus rundinaceus in eastern Spain
2017
[EN] This research deals with two insectivorous reedbed-nesting songbirds, the Savi's Warbler Locustella luscinioides and the Great Reed Warbler Acrocephalus arundinaceus breeding at the Marjal de Pego-Oliva (Valencia-Alicante, Spain). Our aims were to study the diet and the prey selection of the two species and to assess the dietary differences between them. Diet composition has been assessed by examining samples off regurgitated food obtained using apomorphine as an emetic. Prey availability was estimated through standardized invertebrate sampling. The diet of the two warblers were significantly different and included arthropods belonging to the orders Araneida, Coleoptera, Hymenoptera, H…
Heterozygosity-fitness correlations in adult and juvenile Zenaida Dove, Zenaida aurita.
2013
10 pages; International audience; Understanding how fitness is related to genetic variation is of crucial importance in both evolutionary ecology and conservation biology. We report a study of heterozygosity-fitness correlations in a wild, noninbred population of Zenaida Doves, Zenaida aurita, based on a sample comprising 489 individuals (382 adults and 107 juveniles) typed at 13 microsatellite loci, resulting in a data set comprising 5793 genotypes. In both adults and juveniles, and irrespective of sex, no evidence was found for an effect of either multilocus or single-locus heterozygosity on traits potentially related to fitness such as foraging tactic, competitive ability, and fluctuatin…