Search results for " statistics"
showing 10 items of 1891 documents
2019
IntroductionTeachers and student teachers in Germany are a high-risk population for stress and stress-related mental health problems. This often leads to early retirement in subsequent professional life. Various trials have demonstrated positive effects of stress prevention training on the perceived stress and stress-related symptoms of teachers. Although many studies show positive effects of mindfulness-based stress interventions, there is not yet any mindfulness-based intervention for teachers or student teachers in Germany. The aim of this trial is to evaluate a training that combines mindfulness-based and cognitive interventions into one programme, addressing to the specific burdens of …
Latvia
1924
Latvia
1925
Climate Aridity and the Geographical Shift of Olive Trees in a Mediterranean Northern Region
2021
Climate change leverages landscape transformations and exerts variable pressure on natural environments and rural systems. Earlier studies outlined how Mediterranean Europe has become a global hotspot of climate warming and land use change. The present work assumes the olive tree, a typical Mediterranean crop, as a candidate bioclimatic indicator, delineating the latent impact of climate aridity on traditional cropping systems at the northern range of the biogeographical distribution of the olive tree. Since the olive tree follows a well-defined latitude gradient with a progressive decline in both frequency and density moving toward the north, we considered Italy as an appropriate case to i…
A time series study on the effects of heat on mortality and evaluation of heterogeneity into European and Eastern-Southern Mediterranean cities: resu…
2013
Background: The Mediterranean region is particularly vulnerable to the effect of summer temperature. Within the CIRCE project this time-series study aims to quantify for the first time the effect of summer temperature in Eastern-Southern Mediterranean cities and compared it with European cities around the Mediterranean basin, evaluating city characteristics that explain between-city heterogeneity. Methods: The city-specific effect of maximum apparent temperature (Tappmax) was assessed by Generalized Estimation Equations, assuming a linear threshold model. Then, city-specific estimates were included in a random effect meta-regression analysis to investigate the effect modification by several…
Spatial structure of helminth communities in the golden grey mullet, Liza aurata (Actinopterygii: Mugilidae), from the Western Mediterranean.
2012
Ecological investigations regarding the parasite fauna of grey mullets are scarce. The present study provides a detailed description of the helminth communities of Liza aurata in the Spanish western Mediterranean and analyzes the role of spatial, temporal, and host variables in shaping the infracommunities. In total, 204 fish were collected in 2 localities, situated ca. 290 km apart, in spring and fall of 2004 and 2005. A non-metric multidimensional scaling (NMDS) was used to visualize an ordination of the infracommunities according to their relative similarities in parasite abundances. The relationship between infracommunity composition and explanatory variables (host size, locality, year,…
Distribution of Brachionus species in Spanish mediterranean wetlands
1987
In this study 200 zooplankton samples were Burjassotcollected (1979–1980), from 57 different wetlands in coastal Mediterranean Spain (CMS) and examined for the occurrence of Brachionus species. Data on 17 separate physical and chemical features of these water bodies were obtained from samples collected at the same time. Ten different Brachionus species were found in these wetlands, but only six occurred frequently enough to allow further examination of their distributional patterns using multivariate discriminant analysis. To separate these species, three analyses were performed using the 17 physical and chemical parameters, or their ratios. Three discriminant functions accounted for 80% or…
Using topographical attributes to evaluate gully erosion proneness (susceptibility) in two mediterranean basins: advantages and limitations
2015
Empirical multivariate predictive models represent an important tool to estimate gully erosion susceptibility. Topography, lithology, climate, land use and vegetation cover are commonly used as input for these approaches. In this paper, two multivariate predictive models were generated for two gully erosion processes in San Giorgio basin (Italy) and Mula River basin (Spain) using only topographical attributes as independent variables. Initially, nine models (five for San Giorgio and four for Mula) with pixel sizes ranging from 2 to 50 m were generated, and validation statistics were calculated to estimate the optimal pixel size. The best models were selected based on model performance using…
Poisson white noise parametric input and response by using complex fractional moments
2014
Abstract In this paper the solution of the generalization of the Kolmogorov–Feller equation to the case of parametric input is treated. The solution is obtained by using complex Mellin transform and complex fractional moments. Applying an invertible nonlinear transformation, it is possible to convert the original system into an artificial one driven by an external Poisson white noise process. Then, the problem of finding the evolution of the probability density function (PDF) for nonlinear systems driven by parametric non-normal white noise process may be addressed in determining the PDF evolution of a corresponding artificial system with external type of loading.
Probabilistic characterization of nonlinear systems under Poisson white noise parametric input via complex fractional moments
2014
In this paper the probabilistic characterization of a nonlinear system enforced by parametric Poissonian white noise in terms of complex fractional moments is presented. In fact the initial system driven by a parametric input could be transformed into a system with an external type of excitation through an invertible nonlinear transformation. It is shown that by using Mellin transform theorem and related concepts, the solution of the Kolmogorov-Feller equation for the system with external input may be obtained in a very easy way.