Search results for "Population"
showing 10 items of 9945 documents
Invasion success despite reduction of genetic diversity in the European populations of eastern mosquitofish (Gambusia holbrooki)
2006
The introduction of a few individuals to new, isolated habitats (founder effect) is expected to reduce the genetic variability of a population. At the beginning of the last century a few eastern mosquitofish (Gambusia holbrooki) individuals were introduced to Southern Europe from North America to control malaria‐carrying mosquitoes. We studied the effect of this severe bottleneck on genetic variability in four populations of eastern mosquitofish introduced to Spain and Italy in the early 1900s and compared them to a native population in North America. Using amplified polymorphic DNA–polymerase chain reaction (RADP–PCR) we found a strong reduction of genetic diversity, in terms of both numbe…
Genetic diversity in theCentaurea cinerariagroup (Compositae) in Sicily using isozymes
2006
Abstract The genetic diversity of seven taxa endemic to Sicily, C. cineraria, C. busambarensis, C. ucriae subsp. ucriae, C. ucriae subsp. umbrosa, C. todari, C. erycina and C. saccensis, from 11 localities was investigated using isozymes. Eight loci from five enzyme systems (IDH, MDH, PGD, PGM and PGI) were examined. A total of 19 alleles were identified, some rare and two of them exclusive to different populations. The allelic frequencies and the genetic variability values for each population were calculated. On the whole, the genetic diversity, i.e., average polymorphism (P) = 0.41, average number of alleles per locus (A) = 1.75, Nei's gene diversity (H) = 0.18, is moderate, with the high…
Continental-scale patterns of pathogen prevalence: a case study on the corncrake
2014
Pathogen infections can represent a substantial threat to wild populations, especially those already limited in size. To determine how much variation in the pathogens observed among fragmented populations is caused by ecological factors, one needs to examine systems where host genetic diversity is consistent among the populations, thus controlling for any potentially confounding genetic effects. Here, we report geographic variation in haemosporidian infection among European populations of corncrake. This species now occurs in fragmented populations, but there is little genetic structure and equally high levels of genetic diversity among these populations. We observed a longitudinal gradient…
The peculiarities of genetic structure of the Blumeria graminis f. sp. hordei population in Lithuania
2014
In 2010, samples of Blumeria graminis f. sp. hordei both in sporulation and cleistothecia were collected in Lithuania from spring barley variety ‘Dina’. Eighty monopustule isolates were tested on differentials with well-known resistance genes. Frequencies of virulence genes, virulence complexity and pathotypes were detected. Virulence frequencies showed a wide range from 0 to 90%. The clear tendency of virulence increasing for Vla in cleistothecia was observed during the growing season of the pathogen. No virulences were found against resistances, which were present in the line SI1, as well as no matching virulence was found for the resistance gene mlo in Lithuania in 2010. Wide diversity o…
How Do Young People Cope with Job Flexibility?: Demographic and Psychological Antecendents of the Resistance to Accept a Job with Non-Preferred Flexi…
2002
La flexibilite est souvent vue comme condition necessaire a la survie des marches de travail nationaux et a celle des organisations dans un monde en rapide changement ou s’accroit la competition globale. Elle a adopte diverses formes tels les contrats a duree determinee, l’externalisation, les horaires flexibles, le temps partiel, les heures complementaires, le roulement fonctionnel. De plus, il a ete declare que la flexibilite organisationnelle se doit d’etre accompagnee d’une flexibilite personnelle. Quoi qu’il en soit, face aux nouvelles opportunites de travail, les gens different tant sur le plan de leurs preferences que sur celui de leur comportement. Le but de cette etude est d’identi…
Anthropological investigation of a Kurdish village population from south-eastern Turkey. II. Internal differentiation of morphological features
1988
A small scale village society from southern Turkey has been investigated by demographic, social and anthropological criteria. An internal differentiation of the population on the basis of demographic and social data could be verified for morphological features, too. This is shown clearly by a differentiation of the population into two family complexes. The consequences for the interpretation of metrical random sample surveys in typological investigations are discussed.
The Usefulness of Biometrics for the Study of Avian Connectivity within Europe. A Case Study with BlackcapsSylvia atricapillain Spain
2012
Summary. The use of biometrics in studies of migratory connectivity is still relatively infrequent in Europe. This is partly due to the fact that biometrics is a less accurate tool when compared to ringing recovery data, or such techniques as stable isotope analyses, use of geolocators or satellite telemetry. Combination with one of these (recovery data) allows us to test the usefulness of biometrics in connectivity analyses, as well as to evaluate/quantify the influence of migratory behaviour on phenotypic traits such as flight morphology. We used historical recovery data, together with flight morphology data obtained from a consistent collection protocol during a three-year ringing progra…
Population structure of a parasitic plant and its perennial host
2002
Characterization of host and parasite population genetic structure and estimation of gene flow among populations are essential for the understanding of parasite local adaptation and coevolutionary interactions between hosts and parasites. We examined two aspects of population structure in a parasitic plant, the greater dodder (Cuscuta europaea) and its host plant, the stinging nettle (Urtica dioica), using allozyme data from 12 host and eight parasite populations. First, we examined whether hosts exposed to parasitism in the past contain higher levels of genetic variation. Second, we examined whether host and parasite populations differ in terms of population structure and if their populati…
Análisis de la percepción de la peligrosidad de inundación en el municipio de Tavernes Blanques (Valencia, España). Su papel en la valoración del rie…
2021
Resumen: La Comunidad Valenciana alberga numerosas cuencas pequeñas de dinámica torrencial donde la ocurrencia de avenidas puede afectar a zonas urbanas. La alta ocupación de estas zonas y la baja percepción del riesgo por parte de las poblaciones contribuyen al aumento de la vulnerabilidad, suponiendo la amenaza un riesgo mayor para los grupos humanos. El presente estudio aborda el análisis de la percepción del riesgo de inundación por parte de la población de Tavernes Blanques (Valencia), municipio catalogado como de alto riesgo de inundación por la AVSRE. Para ello se lleva a cabo una encuesta a la población residente en el municipio, cuyos resultados muestran una baja percepción del rie…
Son Actuarialmente Justas Las Tarifas Para Determinar El Coste De Las Pensiones Derivadas De Accidentes De Trabajo? Annlisis Del Perrodo 2011-2015 (A…
2015
Spanish Abstract: Este trabajo analiza si las tarifas que se aplican para la determinacion del denominado “capital coste” de pensiones derivadas de los accidentes de trabajo (AT) y enfermedades profesionales (EP) son las adecuadas, y si la falta de actualizacion periodica ha producido distorsiones financieras entre los actores implicados. A partir de los datos de la Muestra Continua de Vidas Laborales (MCVL) y de la evolucion de la longevidad de la poblacion general en Espana, se estiman tablas de mortalidad para las contingencias de viudedad e invalidez, que combinadas con los parametros economicos y financieros apropiados, permiten construir las bases tecnicas actuarialmente justas para c…