Search results for "mixture"
showing 10 items of 1178 documents
Multilevel Latent Profile Analysis With Covariates : Identifying Job Characteristics Profiles in Hierarchical Data as an Example
2018
Latent profile analysis (LPA) is a person-centered method commonly used in organizational research to identify homogeneous subpopulations of employees within a heterogeneous population. However, in the case of nested data structures, such as employees nested in work departments, multilevel techniques are needed. Multilevel LPA (MLPA) enables adequate modeling of subpopulations in hierarchical data sets. MLPA enables investigation of variability in the proportions of Level 1 profiles across Level 2 units, and of Level 2 latent classes based on the proportions of Level 1 latent profiles and Level 1 ratings, and the extent to which covariates drawn from the different hierarchical levels of th…
A person-oriented approach to diary data. Children’s temperamental negative emotionality increases susceptibility to emotion transmission in father-c…
2015
The notion that some individuals are more prone to emotion transmission than others has prompted the need for a person-oriented approach to emotion transmission in parent-child dyads. The present study applied a person-oriented analysis to examine the patterns of emotion transmission that can be identified in the diary data of father-child dyads, and the extent to which children with high levels of temperamental negative emotionality are particularly susceptible to emotion transmission within the family. Mothers of 149 first grade children (age 6 to 7) completed questionnaires concerning their child’s temperament. Mothers and fathers maintained diary questionnaires (for a total of 7 days) c…
Selective hemicellulose hydrolysis of Scots pine sawdust
2019
The depletion of fossil resources is driving forward the search for new and alternative renewable feedstocks in the production of renewable chemicals, which could replace the petroleum-based ones. One such feedstock is pine (Pinus sylvestris) sawdust, which is generated enormous amounts in Finnish sawmills yearly. However, prior to the utilization in high-value applications, it needs to be fractionated into its constituents. In this work, the objective was to produce monomeric hemicellulose sugars from pine sawdust without degrading cellulose or lignin simultaneously. The influence of the reaction temperature and time, as well as acid type and concentration, was studied. Based on the result…
Blends of Semiflexible Polymers: Interplay of Nematic Order and Phase Separation
2021
Mixtures of semiflexible polymers with a mismatch in either their persistence lengths or their contour lengths are studied by Density Functional Theory and Molecular Dynamics simulation. Considering lyotropic solutions under good solvent conditions, the mole fraction and pressure is systematically varied for several cases of bending stiffness κ (the normalized persistence length) and chain length N. For binary mixtures with different chain length (i.e., NA=16, NB=32 or 64) but the same stiffness, isotropic-nematic phase coexistence is studied. For mixtures with the same chain length (N=32) and large stiffness disparity (κB/κA=4.9 to 8), both isotropic-nematic and nematic-nematic unmixing oc…
Processus sensoriels cognitifs et comportementaux impliqués dans la perception des mélanges odorants alimentaires complexes chez le lapin nouveau-né …
2015
Within each breath, a large diversity of volatiles molecules of the surrounding reaches our olfactory receptors. Despite the chemical complexity of the natural environment, the organisms succeed to represent their world using relevant information carried by single odorants or mixtures. Focusing on the perception of these stimuli, we explored the processes involved in the treatment of this complex information, sometimes supported by mixtures or sub-mixtures. The treatment is based on two processes: the elemental mode, which allows extracting the odor quality of all or some of the elements, or the configural mode which allows the holistic representation of the mixture. In this doctoral thesis…
Comparison of oxidoreductive enzyme activities in three coal tar creosote-contaminated soils
2019
This study used laboratory experiments to compare the effects of coal tar creosote on the activity of oxidoreductive enzymes in sandy loam, loamy sand and sandy clay loam soils. Different amounts of coal tar creosote were added to soil samples as follows: 0 (control), 2, 10 or 50 g kg–1 dry matter. The activity of soil dehydrogenases (DHAs), o-diphenol oxidase (o-DPO), catalase (CAT), nitrate reductase (NR) and peroxidases (POX) was determined. Contamination of soil with coal tar creosote affected oxidoreductase activity. Oxidoreductive enzyme activity following soil contamination with coal tar creosote was in the following order: DHAs > CAT > NR > POX > o-DPO in…
Prenatal air pollution exposure and growth and cardio-metabolic risk in preschoolers
2020
Objectives: We investigated the association between outdoor air pollutants exposure in the first trimester of pregnancy, and growth and cardio-metabolic risk at four years of age, and evaluated the mediating role of birth weight. Methods: We included mother-child pairs (N = 1,724) from the Spanish INMA birth cohort established in 2003-2008. First trimester of pregnancy nitrogen dioxide (NO2) and fine particles (PM2.5) exposure levels were estimated. Height, weight, waist circumference, blood pressure, and lipids were measured at four years of age. Body mass index (BMI) trajectories from birth to four years were identified. Results: Increased PM2.5 exposure in the first trimester of pregnanc…
Evidence of neonatal memory of odor configuration
2013
The perception of some mixtures of odorants engages configural abilities, i.e. the perception of these mixtures as single odor objects. For instance, data in human adults demonstrated that a mixture of two odorants (AB), one smelling like strawberry and the other like caramel, generates the configural perception of the odor of pineapple (Le Berre et al., 2008; Barkat et al., 2012). Configural processing may be adaptive also for young organisms, to which rapid extraction of chemical information from the maternal environment, highly complex, is a prerequisite to survival. Thus, results in newborn rabbits suggest the perception of a unique odor in the AB mixture (smelling like configural pinea…
Predicting tire/pavement noise impact reduction using numerical simulation and experimental data for open graded asphalt mixture
2013
The environmental impact of noise from roads and highways traffic is relevant in urban and rural areas. The use of open-graded asphalt pavements reduces significantly the noise, entrapping the acoustic waves inside the porous structure of the material. In this paper we propose a simulation approach in order to predict the acoustic properties of the asphalt mixture from geometrical and topological indicators. In detail we have generated, using a Random Sequential Adsorption model, synthetic samples starting from the same grading and bitumen contents of real samples manufactured in laboratory. We have measured the acoustic adsorption coefficient of the real samples and we have investigated th…
Antecedents and Consequences of Student-Athletes’ Identity Profiles in Upper Secondary School
2020
The present study examined the identity profiles that upper-secondary-school Finnish student-athletes show, and the extent to which these profiles were associated with their athletic and academic achievements and withdrawal from sports and school. A total of 391 adolescent athletes (51% females) completed assessments of student and athletic identity four times during their time in upper secondary school. Using growth mixture modeling, three groups were identified: (a) dual identity (77%), (b) changing identity (5%), and (c) athletic identity (18%). The higher the academic achievement was at Time 1, the more likely the athletes were to show dual identity than athletic identity profile. Simil…