Search results for "age effect"
showing 10 items of 34 documents
Symmetric BEM Formulations for Elastic-Damage Material Models
1997
BEM analysis for elastic-damage materials is addressed by “undamaged” fundamental solutions. In step-by-step analysis, the actual response is obtained by an iterative procedure in which the undamaged structure is subjected to the loads and to some fictitious strains (or relaxation stresses) simulating the damage effects. Through symmetric BEM, the solution to the typical iteration problem is shown to solve a boundary/domain stationarity principle, whereas the above iterative procedure can be incorporated in a predictor/corrector scheme aimed at the integration of the damage laws. Discretization by boundary and interior elements leads to a symmetric equation system.
Resource competition between sympatric sibling rotifer species
2001
Mechanisms underlying competitive interactions are important in understanding the structure of planktonic communities, particularly the coexistence of similar species. Here we present experimental results of exploitative competition among three sympatric sibling species of the Brachionus plicatilis complex for two differently-sized species of food microalgae. These three rotifer species are to be found in seasonal succession in brackish ponds on the Spanish Mediterranean coast; they can, however, co-occur for long periods. The functional and numerical responses of the three Brachionus species to both food microalgae, although similar, differed. Neither rotifer population growth nor grazing …
Direct interference or indirect exploitation? An experimental study of fitness costs of interspecific competition in voles
2002
Studies on competing mammalian species in the past have focused mainly on the competitive exclusion of one species from the preferred habitat of the other. Investigations on effects of competition and coexistence on individual fitness are rare. In this study we were able to measure effects of interspecific competition on major fitness components, using a system with two vole species in asymmetric competition. Survival, reproduction and space use of bank vole Clethrionomys glareolus females were monitored in 32 enclosed populations over four replicates of eight parallel run enclosures. Into half of the enclosures we introduced an additional number of field voles Microtus agrestis, a dominant…
Simulation of the dynamics of hard ellipsoids
2008
We study a system of uniaxial hard ellipsoids by molecular dynamics simulations, changing both the aspect-ratio X-0 (X-0 = a/b, where a is the length of the revolution axis and b is the length of the two other axes) and the packing fraction phi. We calculate the translational and rotational mean squared displacements, the translational D-trans and the rotational D-rot diffusion coefficients and the associated isodiffusivity lines in the phi - X-0 plane. For the first time, we characterize the cage effect through the logarithmic time derivative of log and log . These quantities exhibit a minimum if the system is supercooled and we show that, consistently with our previous findings, for large…
Relativ alderseffekt i norsk kretslagsfotball : Eksisterer det en relativ alderseffekt blant selekterte norske kretslagsspillere?
2017
Masteroppgave idrettsvitenskap ME517 - Universitetet i Agder 2017 The purpose of this study was to investigate the prevalence of a relative age effect among selected youth players on a regional level in Norwegian soccer and to determine if players born in different quarters of the selectionyear, assess their soccer-related abilities differently. Previuos research has shown that players born early in the selectionyear, has been overrepresented in youth national teams in Europe (Helsen et al., 2005) and talentdevelopment-programs (Carling et al., 2009). A total number of 624 players took part in this study, from 16 out of 18 different regions in Norway and the players were considered the most…
Relative Age Effect in the Sport Environment. Role of Physical Fitness and Cognitive Function in Youth Soccer Players
2019
The need to achieve short-term competitive outcomes in sports may influence the emergence of talent selection strategies, which could bias individuals&rsquo
Effects of omalizumab in severe asthmatics across ages: A real life Italian experience
2016
Background This retrospective study aimed at evaluating long-term effects of Omalizumab in elderly asthmatics in a real-life setting. Methods 105 consecutive severe asthmatics (GINA step 4–5; mean FEV1% predicted:66 ± 15.7) treated with Omalizumab for at least 1 year (treatment mean duration 35.1 ± 21.7 months) were divided into 3 groups according to their age at Omalizumab treatment onset: 18–39, 40–64 and ≥ 65 years. Results Comorbidities, number of overweight/obese subjects and patients with late-onset asthma were more frequent among older people. A similar reduction of inhaled corticosteroids dosage and SABA on-demand therapy was observed in all groups during Omalizumab treatment; a sim…
Evidence for different patterns of chemosensory alterations in the elderly population: impact of age versus dependency
2015
The present experiment aimed to explore the interindividual variability in chemosensory abilities among the elderly population. The chemosensory abilities of 559 subjects, aged from 65 to 99 years, were evaluated. Various categories of the elderly, including people who were living at home either without or with assistance, and people who were living in a nursing home, were interviewed. The results revealed that 43% of the sample presented well-preserved chemosensory abilities, whereas 21% of the participants presented a moderate impairment. Of the sample, 33% presented well-preserved olfactory abilities but strong impairment in gustatory abilities and 3% were nearly anosmic but remained abl…
SEA presidential address: Group connectivity and cooperation
2011
A model-free methodology is used for the first time to estimate a daily volatility index (VIBEX-NEW) for the Spanish financial market.We use a public data set of daily option prices to compute this index and showthat daily changes in VIBEXNEW display a negative, tight contemporaneous relationship with IBEX daily returns, contrary to other common volatility indicators, as an implied volatility indicator or a GARCH(1,1) conditional volatility model. This relationship is approximately symmetric to the sign on VIBEX-NEW changes and asymmetric to the IBEX-35 returns sign, which make it clearly a suitable volatility index for the Spanish stock market. We also examine the relationship between curr…
Shoot age as a confounding factor on detecting the effect of human-induced disturbance on Posidonia oceanica growth performance
2007
Abstract The response of orthotropic rhizome elongation and primary production of Posidonia oceanica to anthropogenic perturbations and potential confounding effects of shoot age were assessed using a Linear Multilevel Model (LMM). This model examined the confounding effect of age by comparing the estimates of impact and variance components obtained by excluding and including Age as an explanatory variable. Age had a negative effect on rhizome elongation and primary production with an annual decrease of 0.6 mm y − 1 and 7 mg dw y − 1 respectively. According to the LMM when age effect was omitted, the differences between disturbed and control locations in rhizome elongation and primary produ…