Search results for "Linear relation"
showing 10 items of 35 documents
The rat liver foci bioassay: II. Investigations on the dose-dependent induction of ATPase-deficient foci by vinyl chloride at very low doses
1985
In order to study the dose-dependence of the genotoxic effect of vinyl chloride (VC) hepatocellular ATPase-deficient foci were evaluated after subchronic exposure of newborn rats. Wistar rats were exposed from day 1 after birth over 10 weeks to 10, 40, 70, 150, 500 and 2000 p.p.m. VC (8 h/day; 5 days/week). One week after cessation of exposure hepatic ATPase-deficient foci were quantitated. For a subsequent investigation lower dose range groups of female and male Wistar and Sprague-Dawley rats were exposed (8 h/day; 5 days/week) to 2.5, 5, 10, 20, 40 and 80 p.p.m. VC. Exposure started at day 3 of life and lasted for 3 weeks. After cessation of exposure the animals were maintained for 10 wee…
Relationship between lanthanide contents in aquatic turtles and environmental exposures
2013
International audience; Trace elements released in the environment during agricultural practices can be incorporated and accumulated in biological fluids and tissues of living organisms. The assessment of these exposures were carried out investigating lanthanide distributions in blood and exoskeleton samples collected from Emys trinacris turtle specimens coming from sites with anthropogenic discharge in western and south Sicily, along migration paths of many bird species from Africa to Europe. The data show a significant (Rxy = 0.72; Rxy > 0.67; α = 0.025) linear relationship between the size of turtle specimens and the lanthanide contents in blood lower than 0.4 μg L−1 whereas this relatio…
Relation between physical activity and academic performance in 3rd-year secondary education students
2011
The main aim of this study was to analyze the relationship between the amount of physical activity and academic performance in 3rd-year secondary education students. The sample was taken from three secondary schools in the area of Barcelona. 284 students (158 girls, 126 boys) with an average age of 14.7 yr. participated. The International Physical Activity Questionnaire was used by students to self-report their amount of physical activity. Students’ academic records were obtained for comparisons. Results showed that there was a linear relationship between academic performance and physical activity; nevertheless, there was a trend to stronger correlation when modeling the relationship betwee…
Relations between subdomains of physical activity, sedentary lifestyle, and quality of life in young adult men
2018
Purpose To assess the relationship between physical activity (PA) in work, transport, domestic and leisure-time domains (with sitting time included) and health-related quality of life (HRQoL) among young adult men. Methods The long version of IPAQ and SF-36 Health Survey were used to assess PA and HRQoL, respectively, in 1425 voluntary 20 to 40 year old Finnish male participants. Participants were divided into tertiles (MET-h/week): Lowest tertile ( 100 MET-h/week). Results The IPAQ domain leisure-time PA predicted positively the Physical Component Summary (PCS) (β=0.11, 95% CI: 0.06 to 0.16) and Mental Component Summary (MCS) (β=0.11, 95% CI: 0.05 to 0.16) dimensions. Occupational PA predi…
Oral health-related quality of life of implant-supported overdentures versus conventional complete prostheses: Retrospective study of a cohort of ede…
2015
Background This work aims to confirm if implant-supported overdentures are a good treatment option for edentulous patients and offer an improvement in quality of life compared with traditional complete prostheses (dentures). Material and Methods This retrospective clinical descriptive study included three evaluation groups: validation group (n=57); control group of patients with complete removeable prostheses (n=56); study group of patients with implant-supported overdentures retained with the Locator® system (n=80). The study also validated the Oral Health Impact Profile-20 questionnaire. Individual protocols were created that included socio-demographic data, the Oral Health Impact Profile…
Parameters analysis of FitzHugh-Nagumo model for a reliable simulation
2014
International audience; Derived from the pioneer ionic Hodgkin-Huxley model and due to its simplicity and richness from a point view of nonlinear dynamics, the FitzHugh-Nagumo model has been one of the most successful neuron / cardiac cell model. It exists many variations of the original FHN model. Though these FHN type models help to enrich the dynamics of the FHN model. The parameters used in these models are often in biased conditions. The related results would be questionable. So, in this study, the aim is to find the parameter thresholds for one of the commonly used FHN model in order to pride a better simulation environment. The results showed at first that inappropriate time step and…
Ceftazidime Determination in Serum by High-pressure Liquid Chromatography
2004
A rapid and sensitive high-pressure liquid chromatographic method with simple sample preparation was developed for the quantitative analysis of the beta-lactam antibiotic ceftazidime (CAS 78439-06-2, Fortum). A good linear relationship was established between the peak area and the amount of ceftazidime injected over a concentration range of 1 to 200 microg/ml. The detection limit of the method was calculated to be 0.9 microg/ml. Stability was shown at 4 degrees C and at -196 degrees C for time periods of 2 h and 84 days, respectively.
Loop quantum gravity and Planck-size black hole entropy
2007
The Loop Quantum Gravity (LQG) program is briefly reviewed and one of its main applications, namely the counting of black hole entropy within the framework is considered. In particular, recent results for Planck size black holes are reviewed. These results are consistent with an asymptotic linear relation (that fixes uniquely a free parameter of the theory) and a logarithmic correction with a coefficient equal to -1/2. The account is tailored as an introduction to the subject for non-experts.
Quasi-brittle porous material: Simulated effect of stochastic air void structure on compressive strength
2021
Abstract The effect of porosity comprised of spherical air voids on the compressive strength of quasi-brittle material was studied via simulations. The simulated porous structures were based on pore size distributions of two mortar samples measured by X-ray microtomography. While the simulation method set practical limits on the size of sample, the base of the statistics was established by simulating 128 small structures generated by sampling from pore structures of two mortars. By studying the application of the classical strength-porosity formulas to the simulated data, a new simple model was formed. A linear relationship was achieved between the cubic root of air void fraction (porosity)…
The Influence of Entrepreneurial Learning in New Firms’ Performance: A Study in Costa Rica
2014
The creation of new firms is important for the economy, and entrepreneurial learning is essential for the performance of new firms. We contribute to existing knowledge by combining these two topics and considering a third one: The role of multinational companies (MNCs) as a source of learning for the entrepreneur. This approach has rarely been taken in the literature. We investigated the performance of a group of young companies created by former employees of MNCs and their relationship with entrepreneurial learning in such companies. The study was based on a sample of 175 former employees of MNCs in Costa Rica, who founded their own firm between 2001 and 2007. The control group was formed …