Search results for "feature"
showing 10 items of 4091 documents
Data for nine autosomal STRs markers from Valencia (East Mediterranean coast of the Iberian Peninsula)
2000
Nine STRs loci have been typed in a sample from Valencia, a population from the East Mediterranean coast of the Iberian Peninsula.
Plant speciation in continental island floras as exemplified byNigellain the Aegean Archipelago
2008
Continental shelf island systems, created by rising sea levels, provide a premier setting for studying the effects of geographical isolation on non-adaptive radiation and allopatric speciation brought about by genetic drift. The Aegean Archipelago forms a highly fragmented complex of mostly continental shelf islands that have become disconnected from each other and the mainland in relatively recent geological times (ca<5.2 Ma). These ecologically fairly homogenous islands thus provide a suitable biogeographic context for assessing the relative influences of past range fragmentation, colonization, gene flow and drift on taxon diversification. Indeed, recent molecular biogeographic studies…
Genetic diversity of two perch Perca fluviatilis populations of the Latgale region
2015
Molecular markers based on retrotransposons possibility of integration into genomes of many organisms are commonly used for genetic analysis of different species. The aim of this study was to test possibility of use those markers in perch and detect genetic diversity of populations of two lakes of the Latgale region of Latvia: Cirišs and Sventes. The distance between the lakes is nearly 60 km, they belong to the same Daugava river basin but are different from ecological point of view. Forty two blood samples of <em>Perca fluviatilis </em>were collected altogether. Extracted DNA was analyzed using inter-PBS amplification technique with specifically selected retrotransposon-based …
The distribution and genetic diversity of the common hamsterCricetus cricetusin Central and Western Romania
2015
The existing literature, museum records, personal reports of field biologists and our own field results were compiled to assess the present distribution of the common hamster within Transylvania and the Pannonian Plain of Romania. Combining available distribution data and the existence of natural barriers we were able to designate five, possibly separate, populations: the Pannonian Plain, the Transylvanian Plateau, the Olt Valley, the Brasov Depression and the Ciuc Depression population. The Pannonian Plain and the Transylvanian Plateau populations showed mass outbreaks in recent years. Twenty three individuals were available for the genetic analyses. The populations belonged to the Pannoni…
Genetic Diversity of Mute Swan Population of the Riga Urban Area
2015
Abstract Mute swan Cygnus olor is the most abundant breeding swan species in Rīga and Latvia. Since manmade habitats are the preferred breeding habitats of this species - Cygnus olor is of particular interest in studies of urban biodiversity. The latest records show that 30-40 pairs breed annually in Rīga, 400-700 individuals migrate through the area, and 120-150 individuals stay over winter. The goal of our study was to determine the genetic variation of the mute swan population in Rīga. Blood samples were collected from 47 individual birds found in different sites in Rīga or elsewhere in Latvia. The universal retrotransposon based iPBS markers were used to estimate diversity. Three primer…
Isolation and biodiversity inCytisus villosusPourret (Fabaceae, Genisteae): enzyme polymorphism in disjunct populations
1997
ABSTRACT The genetic diversity of isolated populations of Cytisus villosus has been studied by means of enzyme polymorphism analysis. Two types of isolated populations were studied: “terrestrial islands” in Sicily, and “true islands” in the Aeolian archipelago. In the populations of “true islands” the number of alleles and the heterozygosity are lower than in “terrestrial islands”. Isolation amongst Sicilian populations seems to be more recent than isolation of the Aeolian populations, and may be attributed to climatic changes which occurred during the Holocene and/or to human activities. The disjunction of the Aeolian populations seems much more recent than the origin of the isles themselv…
Causes of the genetic architecture of south-west European high mountain disjuncts
2008
Background: Postglacial climatic warming in south-western Europe and the retreat of cold-adapted species into higher elevations, starting in the Sierra Nevada and proceeding northwards to the Pyrenees and Alps, should have resulted in a pattern of ‘successive vicariance’. Alternatively, long-distance dispersal might explain the extant distribution pattern of mountain species in this region. Aims: Here, we report an investigation of two alpine plants, Saxifraga oppositifolia and S. stellaris, which co-occur in the Sierra Nevada, the Pyrenees, and the south-western Alps/Massif Central. Our aim was to distinguish between (successive) vicariance and long-distance dispersal as alternative explan…
Cytokine regulatory effects on α-1 proteinase inhibitor expression in NOD mouse islet endothelial cells
2002
Human microvascular islet endothelial cells (IEC) exhibit specific morphological and functional characteristics that differ from endothelia derived from other organs. One of these characteristics is the expression of alpha-1 proteinase inhibitor (Api). In this study, we observed its expression in nonobese diabetic (NOD) mouse IEC, in relation to the occurrence of type 1 diabetes and in response to cytokines, namely IL-1 beta and IL-10. In addition, IL-10-deficient NOD mice as well as IL-10 transgenic NODs were studied. Results have demonstrated that Api expression is: (i) highly specific for IEC in NOD mouse islets, as for humans; (ii) linked to the occurrence of early type 1 diabetes, and …
Geosphere-biosphere interactions in bio-activity volcanic lakes: Evidences from Hule and Rìo Cuarto (Costa Rica)
2014
Hule and R ́ıo Cuarto are maar lakes located 11 and 18 km N of Poa ́s volcano along a 27 km long fracture zone, in the Central Volcanic Range of Costa Rica. Both lakes are characterized by a stable thermic and chemical stratification and recently they were affected by fish killing events likely related to the uprising of deep anoxic waters to the surface caused by rollover phenomena. The vertical profiles of temperature, pH, redox potential, chemical and isotopic compositions of water and dissolved gases, as well as prokaryotic diversity estimated by DNA fingerprinting and massive 16S rRNA pyrosequencing along the water column of the two lakes, have highlighted that different bio-geochemica…
Insensitivity of Tree-Ring Growth to Temperature and Precipitation Sharpens the Puzzle of Enhanced Pre-Eruption NDVI on Mt. Etna (Italy)
2017
On Mt. Etna (Italy), an enhanced Normalized Difference in Vegetation Index (NDVI) signature was detected in the summers of 2001 and 2002 along a distinct line where, in November 2002, a flank eruption subsequently occurred. These observations suggest that pre-eruptive volcanic activity may have enhanced photosynthesis along the future eruptive fissure. If a direct relation between NDVI and future volcanic eruptions could be established, it would provide a straightforward and low-cost method for early detection of upcoming eruptions. However, it is unclear if, or to what extent, the observed enhancement of NDVI can be attributed to volcanic activity prior to the subsequent eruption. We conse…