Search results for "adaptation"
showing 10 items of 1775 documents
Evolution of fitness in experimental populations of vesicular stomatitis virus
1996
Abstract The evolution of fitness in experimental clonal populations of vesicular stomatitis virus (VSV) has been compared under different genetic (fitness of initial clone) and demographic (population dynamics) regimes. In spite of the high genetic heterogeneity among replicates within experiments, there is a clear effect of population dynamics on the evolution of fitness. Those populations that went through strong periodic bottlenecks showed a decreased fitness in competition experiments with wild type. Conversely, mutant populations that were transferred under the dynamics of continuous population expansions increased their fitness when compared with the same wild type. The magnitude of …
Effect of population patchiness and migration rates on the adaptation and divergence of vesicular stomatitis virus quasispecies populations
1999
The effect of migration among different isolated virus quasispecies populations on their adaptation and diversity was analysed through experimental evolution. Anin vitrocell system was employed to simulate migration of vesicular stomatitis virus between isolated homogeneous host cell populations. The results clearly demonstrated a positive correlation between the migration rate and the magnitude of the mean fitness reached by the virus quasispecies populations. The results also showed, although less clearly, that fitness differences among quasispecies decreased with the magnitude of migration. These results are in close agreement with predictions of standard population genetics theory. Thes…
Cost of host radiation in an RNA virus.
2000
Abstract Although host radiation allows a parasite to expand its ecological niche, traits governing the infection of multiple host types can decrease fitness in the original or alternate host environments. Reasons for this reduction in fitness include slower replication due to added genetic material or modifications, fitness trade-offs across host environments, and weaker selection resulting from simultaneous adaptation to multiple habitats. We examined the consequences of host radiation using vesicular stomatitis virus (VSV) and mammalian host cells in tissue culture. Replicate populations of VSV were allowed to evolve for 100 generations on the original host (BHK cells), on either of two …
Coping strategies and postpartum depressive symptoms: A structural equation modelling approach.
2014
AbstractBackgroundVariables such as the mother's personality, social support, coping strategies and stressful events have been described as risk factors for postpartum depression. Structural Equation Modelling (SEM) analysis was used to examine whether neuroticism, perceived social support, perceived life events, and coping strategies are associated with postpartum depressive symptoms at the 8th and 32nd weeks.MethodsA total of 1626 pregnant women participated in a longitudinal study. Different evaluations were performed 8 and 32 weeks after delivery. Several measures were used: the Edinburgh Postnatal Depression Scale (EPDS), the Diagnostic Interview for Genetic Studies (DIGS), the Eysenck…
Personality types during transition to young adulthood: how are they related to life situation and well-being?
2014
Abstract The present longitudinal study examined personality types, their change, and their relations with life outcomes and well-being in a sample of young Finns ( N = 493) that was followed from age 15 to 23. The Big Five traits were measured at ages 20 and 23, and four personality types – Resilients, Overcontrollers, Anti-Resilients, and “Averages” – emerged at both time points. Those with higher initial well-being were more likely to be later classified as Resilients, whereas those with low and decreasing well-being were more likely to be classified as Anti-Resilients. At age 23, Anti-Resilients were less likely to have reached normative educational goals than others, and more likely t…
Assessing Time Management Skills as an Important Aspect of Student Learning
2004
The main purpose of this study is to analyse the factorial structure, psychometric properties and predictive capacity for academic achievement of a scale designed to evaluate the time management skills of Spanish high school students. An adaptation of the Time Management Questionnaire was presented to two samples of 350 Spanish high school students. Exploratory and Confirmatory Factor Analysis results from the two samples shows an adequate fit of a three-factor oblique model, as well as its superior explanatory capacity compared to other competitive models considered. This model basically reproduces the structure of the original scale, integrating the subscales on short-range planning, lon…
Adolescent Sexual and Emotional Development: The Role of Romantic Relationships
2015
Abstract The physiological processes occurring during adolescence, often so abrupt, threaten the permanence of the previously constructed sense of identity, questioning the patterns and representations that had governed the relations of the teenager with his body and with his relational systems. Although puberty is not only reduced to sexual transformations, definitions centered mainly on this aspect can be found in the literature. In fact, pubertal development is the acquisition disclosure index of adult reproductive capacity. Objective Explore the process of increasing involvement of the adolescent in an emotional and sexual relationship with a partner. Methodology: It will try to underst…
Finnish interpretations of Creative Physical Education
2016
ABSTRACTWhen physical education (PE) teachers change their programs to incorporate something new, the process always involves some effort at interpretation and adaptation. The perceived benefits must outweigh the labour required to think through the possibilities and to then manage the political and logistical challenges that go hand in hand with achieving change of this magnitude. This paper tells the story of one such change process, which involved the interpretation by a small group of teachers in Finland of a set of pedagogical ideas and practices developed in Australia known as Creative Physical Education. The story involves a range of characters (including the authors) and conveys the…
Measuring business performance in the metal finishing industry by combining theory with practice
2019
Little attention has been spent on the adaptation and implementation of theoretical Business Performance Measurement (BPM) models to specific industry and company contexts leading to a limited prac...