Search results for "Season"
showing 10 items of 1002 documents
Delayed maturation in plumage colour: Evidence for the female-mimicry hypothesis in the kestrel
1993
In many sexually dichromatic species, young males have female-like plumage during their first potential breeding year. The female-mimicry hypothesis (FMH) supposes that by possessing female-like plumage young males deceive older conspicuous males into believing that they are females, thus reducing competition from adult males. The status-signalling hypothesis (SSH) supposes that adult males can distinguish sex, but postulates that young males reduce competition from adult males by reliably signaling low status with their dull plumage. We tested these hypotheses in the European kestrel (Falco tinnunculus). Female-like young males settled to breed closer to adult males than did other adult ma…
Screen media time usage of 12-16 year-old Spanish school adolescents: Effects of personal and socioeconomic factors, season and type of day.
2007
Abstract This study examined screen media time usage (SMTU) and its association with personal and socioeconomic factors, as well as the effect of season and type of day, in a Spanish sample of 12–16 year-old school adolescents (N = 323). The research design was a cross-sectional survey, in which an interviewer-administered recall questionnaire was used. Statistical analyses included repeated measures analyses of variance, analysis of covariance and structural equation models. Results showed an average of 2.52 h per day of total SMTU and partial times of 1.73 h per day in TV viewing, 0.27 h per day in computer/videogames, and 0.52 h per day in mobile use. Four significant predictors of SMTU …
Symbiotic N2 fixation activity in relation to C economy of Pisum sativum L. as a function of plant phenology
2003
The relationships between symbiotic nitrogen fixation (SNF) activity and C fluxes were investigated in pea plants (Pisum sativum L. cv. Baccara) using simultaneous 13 C and 15 N labelling. Analysis of the dynamics of labelled CO 2 efflux from the nodulated roots allowed the different components associated with SNF activity to be calculated, together with root and nodule synthetic and maintenance processes. The carbon costs for the synthesis of roots and nodules were similar and decreased with time. Carbon lost by turnover, associated with maintenance processes, decreased with time for nodules while it increased in the roots. Nodule turnover remained higher than root turnover until flowering…
Early screening of new accumulating versus non-accumulating tree species for the phytomanagement of marginal lands
2019
International audience; The use of fast-growing trees producing a high quantity of biomass can bring significant practical and economic benefits to the reclamation of marginal lands. The present study aims to identify new shrub/tree species to offer a wider range of shrubs/trees useful for phytomanagement practices. We implemented three experimental sites in France of 1 ha each (Thann, Carrières-sous-Poissy and Leforest) contaminated by different potentially toxic elements (PTE) with a total of 38 different tree species. After two years of growth, the element concentrations in stem and leaf biomasses, tree survival rate and growth of plants were assessed. Although the three sites had elevat…
Risk Analysis of Human Anisakidosis Through the Consumption of the Blue Whiting, Micromesistius poutassou, Sold at Spanish Supermarkets
2012
European legislation directed at the catering industry concerning the prevention of anisakidosis proposes efficient measures to avoid human infestation, but this legislation does not directly address the consumer at the household level. Assessing the anisakidosis risk for consumers who buy fresh fish at supermarkets in Spain, 284 blue whiting, Micromesistius poutassou, specimens, originating from two fishing zones and seasons of capture, sold at five nationwide Spanish supermarket chains, were examined to identify the presence of anisakid species and analyze their prevalence and abundance in viscera and flesh. The potential influence of intrinsic (length and weight) and extrinsic (origin, s…
Malaria resurgence risk in southern Europe: climate assessment in an historically endemic area of rice fields at the Mediterranean shore of Spain
2010
Abstract Background International travel and immigration have been related with an increase of imported malaria cases. This fact and climate change, prolonging the period favouring vector development, require an analysis of the malaria transmission resurgence risk in areas of southern Europe. Such a study is made for the first time in Spain. The Ebro Delta historically endemic area was selected due to its rice field landscape, the presence of only one vector, Anopheles atroparvus, with densities similar to those it presented when malaria was present, in a situation which pronouncedly differs from already assessed potential resurgence areas in other Mediterranean countries, such as France an…
Etude expérimentale de la lamination des stromatolithes à Rivularia haematites en climat tempéré: édification des lamines micritiques
1997
The lamination of Rivularia haematites stromatolites (D.C.) Agardh was studied experimentally for 7 years. Micritic laminae are found to form in three stages: biological formation of dark laminae during the wet season, microsparitic calcification of these laminae in the form of clearly individualized polycrystalline aggregates and, finally, micritization of the latter by bacterial action. These three stages develop over 2 to 3 years. The occurrence of transverse, longitudinal and circular microfibrils in the outer sheath is thought to explain the nucleation and the three-dimensional structure of the microsparitic crystals of the dark laminae and of the polycrystalline aggregates.
Rotavirus surveillance in europe, 2005-2008: web-enabled reporting and real-time analysis of genotyping and epidemiological data.
2009
International audience; BACKGROUND: The first European rotavirus surveillance network, EuroRotaNet, comprising 16 laboratories in 15 European countries, has been established. METHODS: Fecal samples from gastroenteritis cases positive for group A rotavirus antigen were collected from multiple European countries from 2005 to mid-2008 and were subjected to G and P genotyping. Epidemiological data collected included age, sex, geographical location, setting, dates of onset and sample collection, and clinical symptoms. RESULTS: A total of 8879 rotavirus-positive samples were characterized: 2129 cases were from the 2005-2006 season, 4030 from the 2006-2007 season, and 2720 from the ongoing 2007-20…
Virus diversity in a winter epidemic of acute diarrhea in France.
2002
ABSTRACT In France, an epidemic peak of acute diarrhea is observed each winter. Previous results suggested a viral etiology for these winter epidemics. We investigated the role of enteric viruses in acute diarrhea and their molecular diversity. One hundred sixty-one patients with acute diarrhea and 45 healthy patients (controls) from the general population were given a standardized questionnaire between December 1998 and May 1999. Stool specimens were screened for group A and C rotaviruses, human caliciviruses, astroviruses, and adenovirus types 40 and 41 by reverse transcription-PCR and/or enzyme immunoassay. Virologic analysis was positive for 63 cases (39%). Caliciviruses and group A rot…
Early Warning Systems for Food Security in West Africa: Evolution, Achievements and Challenges
2010
In West Africa, early warning systems (EWSs) for food security have been widely recognized to have contributed, in the last 20 years, to an improved ability to deal with famine emergencies. Nevertheless, despite the advancements in understanding of the environmental and socio-economic dynamics and despite the improved technologies, tackling food security remains a difficult task for decision makers as demonstrated by local food crises in many countries of the region. African Monsoon Multidisciplinary Analysis, while improving the understanding of the monsoon system, allowed us to better orient research challenges to provide EWS with improved products, effectively meeting the needs of end-us…