Search results for "Regression analysi"
showing 10 items of 813 documents
The effect of periodic bottlenecks on the competitive ability of Drosophila pseudoobscura lines.
1993
Competition experiments between several Drosophila pseudoobscura strains that were previously subjected to periodic bottlenecks of different sizes and D. willistoni have been carried out. Contrary to previous results with these two species, where stable coexistence was detected, populations of D. pseudoobscura displaced D. willistoni in a few generations. By using a relative fitness measure, the control lines (that had not gone through bottlenecks) outcompeted D. willistoni faster than bottlenecked lines. One of these, corresponding to the minimum possible bottleneck size of one pair, also shows significantly lower relative fitness than the other strains. These results are discussed in rela…
Feature extraction from remote sensing data using Kernel Orthonormalized PLS
2007
This paper presents the study of a sparse kernel-based method for non-linear feature extraction in the context of remote sensing classification and regression problems. The so-called kernel orthonormalized PLS algorithm with reduced complexity (rKOPLS) has two core parts: (i) a kernel version of OPLS (called KOPLS), and (ii) a sparse (reduced) approximation for large scale data sets, which ultimately leads to rKOPLS. The method demonstrates good capabilities in terms of expressive power of the extracted features and scalability.
Sources of life satisfaction judgments in Latvia
2010
AbstractResearch indicates that life satisfaction judgments may be influenced by many different factors, but there is no clear evidence how these judgments are constructed. The purpose of this study was to examine sources of life satisfaction judgments in Latvia. Respondents (N=605) aged 18 - 70 completed self report measures of life satisfaction (SWLS), satisfaction with life domains, stressful life events, positive and negative affects (PANAS). Regression analysis shows that model including satisfaction with different life domains, positive and negative affects and number of stressful life events measures explains 53% of the variance in the overall life satisfaction. Immediately after com…
A Macroeconomic Analysis of Regional Migration in Finland, 1975-95
1999
This study analyzes regional migration in the 85 Finnish subregions during the period 1975-95 using data on net in-migration rates. Both cross-section and panel data methods are employed. The regression analysis reveals that the direction of net in-migration flows can be explained by a set of regionally differing characteristics. Unemployment rates, tax rates, and the share of primary production affect net in-migration negatively, whereas the share of higher education and the growth of regional incomes have a positive effect. This indicates that regional disparities may not be alleviated by migration, but there is some evidence for a cumulative causation growth pattern induced by net in-mig…
Examining the association between exposome score for schizophrenia and functioning in schizophrenia, siblings, and healthy controls: results from the…
2021
European Community's Seventh Framework Program, European Commission [HEALTH-F2-2009-241909]; Scientific and Technological Research Council of Turkey, 2219 International Postdoctoral Research Fellowship Program; Spanish Ministry of Science and Innovation, Instituto de Salud Carlos III (SAM16PE07CP1, PI16/02012, and PI19/024)...
Exploring twitter for csr disclosure: influence of ceo and firm characteristics in latin american companies
2018
Social networks, which are characterised by accessibility and interactivity, offer great potential for dialogue between companies and stakeholders, for example as platforms for publishing information on aspects of corporate social responsibility (CSR). In this paper, we use a synthetic index to analyse levels of CSR disclosure via Twitter, and identify explanatory variables of this disclosure by studying the demographic characteristics of the Chief Executive Officer (CEO) and of the company. This synthetic index was based on data for 93 companies located in the four countries of the Pacific Alliance (Chile, Colombia, Mexico, and Peru), using categories based on the 2016 Global Reporting Ini…
Quantification of intracranial contribution to rheoencephalography by a numerical model of the head
2000
Abstract Objectives : Partial contributions of intracranial and extracranial circulation to rheoencephalography (REG) remain uncertain. The main goal of this work is to determine theoretically the capability of REG techniques to reflect intracranial blood flow. Methods : Head and current injection electrodes were computationally modeled to assess REG sensitivity to brain and scalp conductivity changes. Data obtained were related to tissue perfusions to calculate the partial contribution of cerebral blood perfusion to REG I, REG II and monopolar REG and to assess their amplitudes. Results : When REG I and monopolar REG were used, the theoretical maximum of intracranial contribution was reach…
Application of Molecular Topology to the Prediction of the Reaction Yield and Anticancer Activity of Imidazole and Guanidine Derivatives
2013
In this study molecular topology based QSAR has been applied to predict the reaction yield and anticancer activity of 18 imidazole and guanidine derivatives. Four properties were evaluated, namely reaction yield, anti prostatic-cancer activity, anti breast-cancer activity and anti lung-cancer activity. The four models have been validated by both internal and cross validation, and also by randomness tests. The results obtained are in full agreement with the experimental results and confirm the precision, accuracy and robustness of the method followed. After carrying out a virtual screening upon such models, new imidazole and guanidine derivatives with potential anticancer activity are propos…
The relationship among beliefs about problem solving, epistemological beliefs, grade level, sex, and problem solving achievement: A study in secondar…
2020
The first purpuse of this investigation was to study the effects of sex and grade level on secondary students’ beliefs about epistemology and problem solving. The second purpuse was to analyze the contribution of both belief systems, grade level, and sex to problem solving achievement. One hundred and forty-four High School students, 9th and 11th grade students, took part in the study. Two questionnaires (Schommer and StageKloosterman’s questionnaires) and a problem solving test (two word problems of the PISA tests) were administered to these students. Two ANOVAs, an ANCOVA, and a multiple regression analysis were carried out from data obtained in the investigation. In the light of the fore…
Sickness presenteeism of German teachers: prevalence and influencing factors
2016
AbstractThe aim of the present study was to investigate teachers’ sickness presenteeism (SP). We examined the prevalence of SP in a sample of teachers as well as work-related and health-related influencing factors of teachers’ SP. We used a cross-sectional study design. Teachers working at different types of schools in Rhineland-Palatinate (Germany) participated in an online survey. We used Pearson’s Chi-squared test (in case of categorical variables) or Mann–Whitney-U-test (in case of continuous variables) to test for differences between SP and sociodemographic/work-related/health-related factors. Factors influencing SP were identified using multivariable logistic regression analyses. Nine…