Search results for " Population"
showing 10 items of 1682 documents
Häufigkeit, Altersabhängigkeit und Geschlechtsverteilung des Fersensporns
1995
In 1027 lateral radiograms of the ankle in a Caucasian population, 161 plantar and/or dorsal calcaneal spurs (15.7%) were diagnosed. Plantar spurs were more common than dorsal spurs (11.2 and 9.3% respectively). Prevalence of both spurs increases considerably with the rising age. Dorsal spurs appear slightly earlier than plantar spurs. The spur frequencies are similar in left and right feet. The plantar spurs were significantly (p < 0.0001) more common in women than in men in general, while dorsal spurs were more frequent in men than in women up to the age of 70. The previously reported higher frequencies of plantar and dorsal calcaneal spurs in women than in men are probably a result of a …
Population Properties of Compact Objects from the Second LIGO-Virgo Gravitational-Wave Transient Catalog
2021
Abbott, R., et al. (LIGO and Virgo Collaboration)
Modeling epidemics through ladder operators
2020
Highlights • We propose an operatorial model to describe epidemics. • The model describes well the asymptotic numbers of the epidemics. • Ladder operators are used to model exchanges between the “actors” of the system.
Diversifying crop rotations with temporary grasslands: potentials for weed management and farmland biodiversity
2010
Fruchtfolgen können dazu dienen, die kontinuierliche Selektion von Unkrautarten zu verhindern, die an eine bestimmte Kultur angepasst sind. Dies könnte dem Unkrautmanagement, der Einsparung von Herbiziden, und der Biodiversität dienen. Heutige, sehr einfache Furchtfolgen könnten durch mehrjährige Futterkulturen diversifiziert werden. Die Einflüsse solcher mehrjähriger Kulturen auf Unkräuter wurden in vier Ansätzen untersucht : 1) Vegetationsaufnahmen auf 632 Feldern in Westfrankreich zeigten, dass die Unkrautzusammensetzung zwischen mehrjährigen Futterkulturen und einjährigen Kulturen stark variiert. Der Vergleich von Feldern vor, während und nach mehrjährigen Futterkulturen legte nahe, das…
Non-Occupational Exposure to Pesticides: Experimental Approaches and Analytical Techniques (from 2019)
2021
© 2021 by the authors.
Estudios estratégicos para la lucha contra la fascioliasis humana a nivel mundial = Strategic studies for the fight against de human fascioliasis wor…
2013
Fascioliasis is a zoonotic parasitic disease caused by Fasciola hepatica and F. gigantica. Emergence of human fascioliasis prompted a worldwide control initiative including a pilot study in several countries. Given the necessity to characterize the fasciolid populations involved, the overall aim of the present research is, first, the phenotypic characterization of faciolid adults and eggs implicated in human endemic areas, where this initiative has been implemented, through a computer image analysis system (CIAS) applied on the basis of standardized measurements. Second, new immunological techniques and their potential use as immunological diagnostic tests in those areas are evaluated. The …
Maintenance of genetic diversity in cyclic populations - a longitudinal analysis in Myodes glareolus
2012
Conspicuous cyclic changes in population density characterize many populations of small northern rodents. The extreme crashes in individual number are expected to reduce the amount of genetic variation within a population during the crash phases of the population cycle. By long-term monitoring of a bank vole (Myodes glareolus) population we show that despite the substantial and repetitive crashes in the population size, high heterozygosity is maintained throughout the population cycle. The striking population density fluctuation in fact only slightly reduced the allelic richness of the population during the crash phases. Effective population sizes of vole populations remained also relativel…
Mitochondrial sequence analysis of Salamandra taxa suggests old splits of major lineages and postglacial recolonizations of Central Europe from disti…
2000
Representatives of the genus Salamandra occur in Europe, Northern Africa and the Near East. Many local variants are known but species and subspecies status of these is still a matter of dispute. We have analysed samples from locations covering the whole expansion range of Salamandra by sequence analysis of mitochondrial D-loop regions. In addition, we have calibrated the rate of divergence of the D-loop on the basis of geologically dated splits of the closely related genus Euproctus. Phylogenetic analysis of the sequences suggests that six major monophyletic groups exist (S. salamandra, S. algira, S. infraimmaculata, S. corsica, S. atra and S. lanzai) which have split between 5 and 13 milli…
The effect of inbreeding rate on fitness, inbreeding depression and heterosis over a range of inbreeding coefficients
2014
Understanding the effects of inbreeding and genetic drift within populations and hybridization between genetically differentiated populations is important for many basic and applied questions in ecology and evolutionary biology. The magnitudes and even the directions of these effects can be influenced by various factors, especially by the current and historical population size (i.e. inbreeding rate). Using Drosophila littoralis as a model species, we studied the effect of inbreeding rate over a range of inbreeding levels on (i) mean fitness of a population (relative to that of an outbred control population), (ii) within‐population inbreeding depression (reduction in fitness of offspring fro…
Maintenance of genetic diversity in cyclic populations—a longitudinal analysis in Myodes glareolus
2012
Conspicuous cyclic changes in population density characterize many populations of small northern rodents. The extreme crashes in individual number are expected to reduce the amount of genetic variation within a population during the crash phases of the population cycle. By long-term monitoring of a bank vole (Myodes glareolus) population, we show that despite the substantial and repetitive crashes in the population size, high heterozygosity is maintained throughout the population cycle. The striking population density fluctuation in fact only slightly reduced the allelic richness of the population during the crash phases. Effective population sizes of vole populations remained also relative…