Search results for "agricultural and biological sciences"
showing 10 items of 1704 documents
Survey of the parasitoids of the European Sunflower MothHomoeosoma nebulella [Lep.: Pyralidae] in the palearctic region
1993
The European Sunflower MothHomoeosoma nebulella Denis & Schiffermuller is a potential pest on sunflower in France. The parasitoids of this moth are little known. We present here original data obtained in the south of France together with previous survey. Some parasitoids we found were new records onH. nebulella. The relative weakness of the parasite complex ofH. nebulella (less than 15 species) compared to that of the American Sunflower MothH. electellum (Hulst) is discussed.
AN ANALYSIS OF CONTINENT-WIDE PATTERNS OF SEXUAL SELECTION IN A PASSERINE BIRD
2006
Patterns of selection are widely believed to differ geographically, causing adaptation to local environmental conditions. However, few studies have investigated patterns of phenotypic selection across large spatial scales. We quantified the intensity of selection on morphology in a monogamous passerine bird, the barn swallow Hirundo rustica, using 6495 adults from 22 populations distributed across Europe and North Africa. According to the classical Darwin-Fisher mechanism of sexual selection in monogamous species, two important components of fitness due to sexual selection are the advantages that the most attractive males acquire by starting to breed early and their high annual fecundity. W…
New insights into the diversity dynamics of Triassic conodonts
2013
International audience; In this paper, we examine the diversity trends and the evolutionary patterns of Triassic conodonts through a newly powered large-scale data-set compiled directly from the primary literature. Paleodiversity dynamics analyses have been undertaken by working at the species level and using a system of time units based on biozone subdivisions for a fine temporal level resolution. The role of heterogeneous duration of taxa in diversity estimates has been evaluated through the probabilistic profiles. Results reveal three different stages in the diversity behaviour of Triassic conodonts from standing metrics delimited by two inflections at the mid-Anisian and mid-Carnian. Su…
Culturable endophytic microbial communities in the circumpolar grass,Deschampsia flexuosain a sub-Arctic inland primary succession are habitat and gr…
2014
Summary Little is known about endophytic microbes in cold climate plants and how their communities are formed. We compared culturable putative endophytic bacteria and fungi in the ecologically important circumpolar grass, Deschampsia flexuosa growing in two successional stages of subarctic sand dune (68°29′N). Sequence analyses of partial 16S rRNA and internal transcribed spacer (ITS) sequences of culturable endophytes showed that diverse bacteria and fungi inhabit different tissues of D. flexuosa. A total of 178 bacterial isolates representing seven taxonomic divisions, Alpha, Beta and Gammaproteobacteria, Actinobacteria, Bacteroidetes, Firmicutes and Acidobacteria, and 30 fungal isolates …
THERMOREGULATION CONSTRAINS EFFECTIVE WARNING SIGNAL EXPRESSION
2009
Evolution of conspicuous signals may be constrained if animal coloration has nonsignaling as well as signaling functions. In aposematic wood tiger moth (Parasemia plantaginis) larvae, the size of a warning signal (orange patch on black body) varies phenotypically and genetically. Although a large warning signal is favored as an antipredator defense, we hypothesized that thermoregulation may constrain the signal size in colder habitats. To test this hypothesis, we conducted a factorial rearing experiment with two selection lines for larval coloration (small and large signal) and with two temperature manipulations (high and low temperature environment). Temperature constrained the size and br…
Regeneration in invertebrates
2008
The mechanisms of regeneration are reviewed from a genetic, cytological and molecular biological points of view. Planarians and Hydra have been chosen and illustrated as biological examples.
Phenolic compounds in different olive varieties
2001
Phenolic compounds in different olive varieties were determined by HPLC analysis over 2 years. Demethyloleuropein was found in only two (Coratina and Leccino) of the eight varieties studied, so it could be used as varietal marker. Elenolic acid glucoside and hydroxytyrosol can be considered indicators of maturation for olives. In fact, as the olives ripen, their tenor increases whereas oleuropein decreases. Keywords: Phenolic compounds; olive fruit; oleuropein; demethyloleuropein; 3,4-dihydroxyphenylethanol; elenolic acid glucoside
Watanabea green microalgae (Trebouxiophyceae) inhabiting lichen holobiomes: Watanabea lichenicola sp. nova
2021
Comparison of the Antibiotic-Resistant <i>Enterobacteriaceae</i> Content in Conventional, Organic and Fresh-Cut Vegetables Sold in Valenc…
2020
Bacterial content of fresh vegetables that are often eaten raw represents a risk factor for consumers, and the presence in these produce of antibiotic-resistant bacteria constitutes an additional food safety concern. We have compared the Enterobacteriaceae content, as well as the antibiotic resistances of bacterial isolates, in samples of different types of fresh vegetables (conventional an organic produce, fresh-cut vegetables and prepared salads) marketed in Valencia (Spain) in order to find possible differences among these vegetable types. Bacterial isolation, identification and resistance assays to eleven relevant chemotherapeutics agents were performed according to standard microbiolog…
Distribution of biomass and site location of combustion and gasification power plants in western Sicily
2012
The substitution of conventional fossil fuels with biomass for energy production results both in the reduction of greenhouse gases emissions and in the replacement of non-renewable energy sources. The use of biomass for energy production responds to the growing pressure of government policies towards the achievement of better environmental sustainability of power generation processes. This is particularly true for the agricultural areas of Sicily, where the realization of new economic dynamics can lead to development of a local economic system. However, at present, generating energy from biomass is rather expensive due to both technological limits related to low conversion efficiencies, and…