Search results for "Spar"
showing 10 items of 1739 documents
A formal classification of the Lygeum spartum vegetation of the Mediterranean Region
2019
Aims: We examined all available literature and some unpublished data on the We examined all available literature and some unpublished data on the grasslands dominated by Lygeum spartum from Southern Europe and North Africa to produce a formalised classification of this vegetation and to identify the main factors determining its plant species composition. Location: Mediterranean Basin and Iberian Peninsula. Methods: We used a dataset of 728 releves, which were resampled to reduce unbalanced sampling effort, resulting in a dataset of 568 releves and 846 taxa. We classified the plots by TWINSPAN, interpreted the resulting pools, and used them to develop formal definitions of phytosociological …
Assessing global range expansion in a cryptic species complex: insights from the red seaweed genus Asparagopsis (Florideophyceae)
2017
The mitochondrial genetic diversity, distribution and invasive potential of multiple cryptic operational taxonomic units (OTUs) of the red invasive seaweed Asparagopsis were assessed by studying introduced Mediterranean and Hawaiian populations. Invasive behavior of each Asparagopsis OTU was inferred from phylogeographic reconstructions, past historical demographic dynamics, recent range expansion assessments and future distributional predictions obtained from demographic models. Genealogical networks resolved Asparagopsis gametophytes and tetrasporophytes into four A. taxiformis and one A. armata cryptic OTUs. Falkenbergia isolates of A. taxiformis L3 were recovered for the first time in t…
Phylogenetic relationships among tetraploid species of Bellevalia (Asparagaceae) endemic to south-central Mediterranean
2017
AbstractIn the south-central Mediterranean four tetraploid species of Bellevalia occur: B. dolichophylla, B. galitensis, B. mauritanica, and B. pelagica. Another group of plants, morphologically similar to B. dolichophylla, has been recently recovered in Zembra Island (Tunisia). A phylogenetic reconstruction involving all these tetraploid taxa was performed using both plastidial and nuclear markers (trnL-trnF and ITS, respectively). For all these taxa, an allopolyploid origin involving B. romana and B. dubia is supported. Regarding plants from Zembra, they may fall within the variability of B. dolichophylla.
New polymorphic microsatellite loci in the house sparrow, Passer domesticus.
2009
3 pages; International audience; We developed 13 new polymorphic microsatellite loci in the house sparrow (Passer domesticus), which exhibited from 2 to 15 alleles. Observed and expected heterozygosities ranged from 0.17 to 0.77 and from 0.35 to 0.85, respectively. We detected no linkage disequilibrium between loci. Allele frequencies supported Hardy–Weinberg equilibrium for 8 loci out of 13 after Bonferroni correction. Combined with loci previously isolated in the house sparrow, these new microsatellite markers provide valuable tools to study population genetics of this species.
Antagonistic effects of a Mhc class I allele on malaria-infected house sparrows.
2008
8 pages; International audience; Genes of the Major Histocompatibility Complex (Mhc) play a fundamental role during the immune response because MHC molecules expressed on cell surface allow the recognition and presentation of antigenic peptides to T-lymphocytes. Although Mhc alleles have been found to correlate with pathogen resistance in several host-parasite systems, several studies have also reported associations between Mhc alleles and an accrued infection risk or an accelerated disease progression. The existence of these susceptibility alleles is puzzling, as the cost generated by the infection should rapidly eliminate them from the population. Here, we show that susceptibility alleles…
Plasmodium relictum infection and MHC diversity in the house sparrow (Passer domesticus).
2010
Antagonistic coevolution between hosts and parasites has been proposed as a mechanism maintaining genetic diversity in both host and parasite populations. In particular, the high level of genetic diversity usually observed at the major histocompatibility complex (MHC) is generally thought to be maintained by parasite-driven selection. Among the possible ways through which parasites can maintain MHC diversity, diversifying selection has received relatively less attention. This hypothesis is based on the idea that parasites exert spatially variable selection pressures because of heterogeneity in parasite genetic structure, abundance or virulence. Variable selection pressures should select for…
Predictions of avian Plasmodium expansion under climate change.
2013
International audience; Vector-borne diseases are particularly responsive to changing environmental conditions. Diurnal temperature variation has been identified as a particularly important factor for the development of malaria parasites within vectors. Here, we conducted a survey across France, screening populations of the house sparrow (Passer domesticus) for malaria (Plasmodium relictum). We investigated whether variation in remotely-sensed environmental variables accounted for the spatial variation observed in prevalence and parasitemia. While prevalence was highly correlated to diurnal temperature range and other measures of temperature variation, environmental conditions could not pre…
Otolith fingerprints reveals potential pollution exposure of newly settled juvenile Sparus aurata
2020
Abstract Coastal ecosystems are increasingly threatened by a wide range of human activities. Fish otolith chemistry, by creating a unique specific signature, can be used as a natural tag for determining life stage dispersal, spatial connectivity and population structure. In this study, we tested whether differences in otolith composition among juveniles of gilthead sea bream, Sparus aurata, could enable their proper allocation to polluted areas based on higher concentrations of elements related to contaminants. Otoliths were embedded, sectioned and analysed by LA-ICP-MS in line scan mode. Multivariate analysis confirmed clear separation between sites and elements. Samples from the site unde…
The author's reply to N.R. Haddaway.
2017
Abstract In this reply we respond to the commentary of Dr. Haddaway addressed in searching for pitfalls in our systematic mapping exercise “Collating science-based evidence to inform public opinion on the environmental effects of marine drilling platforms in the Mediterranean Sea” recently published in Journal of Environmental Management (Mangano, M.C. and Sara, G. 2017. Journal of Environmental Management 188: 195–202). We discussed each so called “pitfalls” and, in our opinion, the main cornerstones of systematic map – SM (repeatability, comprehensiveness, transparency, traceability, quality, generalizability) are safe guaranteeing the “gold standard” required by this technique. Where nee…
Parasite communities in Boops boops (L.) (Sparidae) after the Prestige oil-spill: Detectable alterations
2007
Environmental pollution affects parasite populations and communities, both directly and through effects on intermediate and final hosts. In this work, we present a comparative study on the structure and composition of metazoan parasite communities in the bogue, Boops boops, from two localities (Galician coast, Spain) affected by the Prestige oil-spill (POS). We focus on the distribution of both individual parasite species and larger functional groupings by using both univariate and multivariate analyses. Our results indicate directional trends in community composition that might be related to the Prestige oil-spill disturbance of the natural coastal communities off Galicia. Endoparasite com…