Search results for "cam"
showing 10 items of 4055 documents
Crayfish invasion facilitates dispersal of plants and invertebrates by gulls
2018
The red swamp crayfish (Procambarus clarkii), originally from North America, is one of the world's worst aquatic invaders. It is a favoured prey item for waterbirds, but the influence of this novel predator–prey relationship on dispersal of other organisms has not previously been considered. We investigated the potential for dispersal of plants and invertebrates by migratory waterbirds feeding on alien P. clarkii in European ricefields at harvest time. In November–December of 2014–2015, we collected propagules from the outside of 13 crayfish captured as they moved out of ricefields during harvest in Doñana, south‐west Spain. We also collected excreta (N = 76 faeces, 14 pellets) of lesser‐bl…
Stabilization of an enzymatic extract from Penicillium camemberti containing lipoxygenase and hydroperoxide lyase activities
2008
International audience; The stabilization of an enzymatic extract, obtained from Penicillium camemberti containing lipoxygenase (LOX) and hydroperoxide lyase (HPL) activities, was investigated using selected additives. Although the addition of KCl (86%, w/w) to the enzymatic extract decreased slightly (7%) the LOX activity, it increased HPL activity by 2.25 fold; however, the addition of dextran resulted in the inactivation of both enzymatic activities. The stability of the solid lyophilized enzymatic extract was greater in the presence of KCl than that without it, with ∼100% residual activity after 8 and 4 weeks of storage at −80 °C, for LOX and HPL, respectively. The rate constants of ina…
Cave-adapted campodeids (Hexapoda, Diplura, Campodeidae) from the Dinarides and adjacent karst regions
2021
Five new species are described, Plusiocampa (Didymocampa) cvijici Sendra & Antić, sp. nov., Plusiocampa (Plusiocampa) atom Sendra & Antić, sp. nov., Plusiocampa (Stygiocampa) barethae Sendra & Rađa, sp. nov., Plusiocampa (Stygiocampa) dulcici Sendra & Rađa, sp. nov. and Plusiocampa (Venetocampa) pirnati Sendra & Borko, sp. nov. This brings the number of cave-adapted species of campodeids known from the Dinarides, Eastern Alps, Balkan System and Rodope Massif to 28 (one species in the genus Campodea and 27 in Plusiocampa). Among Plusiocampa, four out of five subgenera are present (Pentachaetocampa is not present in the region studied): Didymocampa (one species), Plusiocampa s. str. (15 speci…
Benthic hydroids (Cnidaria, Hydrozoa) from the Ross Sea (Antarctica) collected by the New Zealand Antarctic expedition BioRoss 2004 with RV Tangaroa
2017
During the New Zealand BioRoss 2004 survey, with RV Tangaroa , sampling of marine communities on the Ross Sea shelf was undertaken. Samples were obtained employing several sampling gears (Van Veen grab, epibenthic sled, rough bottom trawl, and beam trawl). Among the numerous benthic samples obtained, a large and important collection of hydroids was present. Sixty-one species, four of them new to science ( Monocoryne antarctica sp. nov., Halecium tangaroa sp. nov., Staurotheca gracilis sp. nov. and Symplectoscyphus densus sp. nov.) have been recorded. Oswaldella blanconae sp. nov. is also described. “Anthoathecata” are represented by ten species belonging to the families Bougainvilliidae, Ca…
No evidence of an immune adjustment in response to a parasitoid threat in Lobesia botrana larvae.
2017
5 pages; International audience; Immune function is a key determinant of an organism's fitness, and natural insect populations are highly variable for this trait, mainly due to environmental heterogeneity and pathogen diversity. We previously reported a positive correlation between infection prevalence by parasitoids and host immunity in natural populations of the vineyard pest Lobesia botrana. Here, we tested whether this correlation reflects a plastic adjustment of host immunity in response to the local presence of parasites. To this end, we measured immunity of non-parasitized L. botrana larvae exposed, respectively, to one of the two most common species of parasitoids in vineyards, over…
Specific color sensitivities of prey and predator explain camouflage in different visual systems
2004
In situations of aggressive mimicry, predators adapt their color to that of the substrate on which they sit for hunting, a behavior that is presumed to hide them from prey as well as from their own predators. Females of few crab-spider species encounter such situations when lying on flowers to ambush pollinators. To evaluate the efficiency of spider camouflage on flowers, we measured by spectroradiometry adult female Thomisus onustus and marguerite daisies, Leucanthemum vulgare. We compared chromatic contrast (color used for short-range detection) of each pair of spider and flower to detection thresholds computed in the visual systems of both Hymenopteran prey and passerine bird predator. W…
Effect of landscape structure on common vole (Microtus arvalis) distribution and abundance at several space scales
1996
This paper aims to answer the following question: are the fluctuations of abundance of Common Vole (Microtus arvalis) specific to different types of landscapes? The research was carried out in landscapes where grassland was dominant. The sampling method was based upon a partition in both landscape types and landscape units. Tracking of vole indices was used to evaluate their relative abundance. Six landscape transects were sampled during two successive years. Results show that population variation and diffusion of demographic states are closely related to landscape types. The possible causes of this are discussed. The landscape units can be used as global variables to assess outbreak risk a…
Germination and emergence of Neslia paniculata (L.) Desv.
2019
Abstract Seed characteristics, either in size or in structure, can affect germination, hence the emergence of a plant species. In the present work germination and emergence of Neslia paniculata, a Brassicaceae species that produces fruits containing one seed covered by a hard fruit coat, was studied. Germination experiments of seed with and without the fruit coat were performed at constant temperatures from 5 to 23 °C under controlled conditions and germination was measured daily. Additionally, seeds were sown in the field and emergence was periodically followed in three sites: Almenar (Spain), Morris (USA) and Riga (Latvia). Both germination and emergence were modelled with Boltzmann and W…
Modelling vertical and lateral weed seed movements during mouldboard ploughing with a skim-coulter
2001
Abstract The vertical distribution of weed seeds in soil is crucial because seedling emergence varies with seed depth, whereas lateral soil displacement during mouldboard ploughing contributes to weed dispersal within the tilled field. In order to model vertical and lateral seed displacements during ploughing, an existing model describing soil particle movements for different ploughing characteristics (depth and width) and soil structures was adapted to integrate the effect of a skim-coulter. This model was tested in two field trials, in Northern France, using coloured plastic beads to imitate weed seeds. The trial in Dijon was set up on an eutric cambisol and comprised both compacted and u…
Quality Characteristics of Wholemeal Flour and Bread from Durum Wheat (Triticum turgidum L subsp. durum Desf.) after Field Treatment with Plant Water…
2016
The use of selected plant water extracts to control pests and weeds is gaining growing attention in organic and sustainable agriculture, but the effects that such extracts may exert on the quality aspects of durum wheat are still unexplored. In 2014, 5 plant water extracts (Artemisia arborescens, Euphorbia characias, Rhus coriaria, Thymus vulgaris, Lantana camara) were prepared and distributed on durum wheat cv Valbelice to evaluate their potential herbicidal effects. After crop harvesting, the major physicochemical and technological parameters of wholemeal flours obtained from each treatment were measured and compared with those from chemical weeding and untreated controls. A baking test w…