Search results for "value"
showing 10 items of 5321 documents
Effect of amorphous sequences on the longitudinal acoustic modes in partially crystalline polymers. I. Transfer matrix method
1983
A novel theoretical scheme is developed which enables the determination of the LAM-like vibrations of polymer chains made up of crystalline and amorphous parts as they occur in partially crystalline structures. The boundary conditions effective at the junction points are formulated in terms of the compliances of the associated amorphous sequences. These compliances can be derived from their eigenfrequencies and eigenvectors in a disconnected state. The treatment uses a matrix formalism which can be extended to include bending and torsional motions in a general state of vibration of the crystalline stem. A first numerical example demonstrates that the LA mode of a crystalline stem can be str…
Endoscopic Anatomy of the Ventricles
1994
The endoscopic view offers a new anatomical dimension to the neurosurgeon. The fact makes it basically necessary to study the topographic anatomy under endoscopic conditions. In this paper attention was drawn to the ventricles because they are the most common region of clinical application. In 25 specimens neuroendoscopic explorations of the ventricles have been done. The dissections have been carried out through one- and two burr hole approaches (two working endoscopes at the same time). The instrumentation includes rigid 4 mm and 6 mm endoscopes. The procedures have been documented by continuous video recording and parallel photography.
Slow Crystallization Kinetics of Poly(vinyl alcohol) in Confined Environment during Cryotropic Gelation of Aqueous Solutions
2006
The gelation kinetics of aqueous solutions of poly(vinyl alcohol) (PVA) during freezing at −13 °C has been investigated with time-resolved small angle neutron scattering. Crystallization of PVA takes place inside an unfrozen liquid microphase that forms in the matrix of ice crystals and follows a first-order kinetics during the early stages and becomes very slow in the later stages with an apparent Avrami exponent lower than 1. Crystallization of PVA at low temperatures is responsible of formation of strong physical gels upon defrosting, provided that the concentration of PVA is higher than a critical value.
In-Depth Characterization of Viral Isolates from Plasma and Cells Compared with Plasma Circulating Quasispecies in Early HIV-1 Infection
2012
Background The use of in vitro models to unravel the phenotypic characteristics of circulating viral variants is key to understanding HIV-1 pathogenesis but limited by the availability of primary viral isolates from biological samples. However, overall in vivo genetic variability of HIV-1 within a subject may not be reflected in the viable viral population obtained after isolation. Although several studies have tried to determine whether viral populations expanded in vitro are representative of in vivo findings, the answer remains unclear due to the reduced number of clonal sequences analyzed or samples compared. In order to overcome previous experimental limitations, here we applied Deep P…
Computational discovery of novel trypanosomicidal drug-like chemicals by using bond-based non-stochastic and stochastic quadratic maps and linear dis…
2009
Herein we present results of a quantitative structure-activity relationship (QSAR) studies to classify and design, in a rational way, new antitrypanosomal compounds by using non-stochastic and stochastic bond-based quadratic indices. A data set of 440 organic chemicals, 143 with antitrypanosomal activity and 297 having other clinical uses, is used to develop QSAR models based on linear discriminant analysis (LDA). Non-stochastic model correctly classifies more than 93% and 95% of chemicals in both training and external prediction groups, respectively. On the other hand, the stochastic model shows an accuracy of about the 87% for both series. As an experiment of virtual lead generation, the …
Stability of the lipid fraction of milk‐based infant formulas during storage
2005
A study is made of the effects of storage (time and temperature) on the lipid fraction of four milk-based adapted infant formulas with basically the same composition, though differing in the iron salt added (lactate or sulfate) and/or the vitamin E source (a-tocopherol or α-tocopherol acetate). Peroxide value, hydroperoxide C 18 percentage and thiobarbituric acid-reactive substance (TBARS) content were used as indicators of lipid peroxidation. Fat contents remained stable throughout storage. Peroxide values increased from the first storage month and were affected by storage time, although they exhibited irregular behavior. Storage time and temperature affected hydroperoxide percentage, whic…
Analysis of dietary patterns and nutritional adequacy in lactating women : a multicentre European cohort (ATLAS study)
2021
Abstract Eating habits of lactating women can influence the nutrient composition of human milk, which in turn influences nutrient intake of breastfed infants. The aim of the present study was to identify food patterns and nutritional adequacy among lactating women in Europe. Data from a multicentre European longitudinal cohort (ATLAS study) were analysed to identify dietary patterns using cluster analysis. Dietary information from 180 lactating women was obtained using 3-d food diaries over the first 4 months of lactation. Four dietary patterns were identified: ‘vege-oils’, ‘fish-poultry’, ‘confectionery-salads’ and ‘mixed dishes’. Nutrition adequacy was not significantly different between …
Folate, related B vitamins, and homocysteine in childhood and adolescence: potential implications for disease risk in later life.
2009
OBJECTIVES. Folate and the metabolically related B vitamins are an important priority throughout life, but few studies have examined their status through childhood and adolescence. The aims of the current study were to investigate age, gender, and lifestyle factors as determinants of folate, related B-vitamin status, and homocysteine concentrations among British children and adolescents and to propose age-specific reference ranges for these biomarkers, which, at present, are unavailable. PARTICIPANTS AND METHODS. Data from the National Dietary and Nutritional Survey of 2127 young people aged 4 to 18 years were accessed to provide a representative sample of British children. All of the subje…
Part-of-Speech Induction by Singular Value Decomposition and Hierarchical Clustering
2006
Part-of-speech induction involves the automatic discovery of word classes and the assignment of each word of a vocabulary to one or several of these classes. The approach proposed here is based on the analysis of word distributions in a large collection of German newspaper texts. Its main advantage over other attempts is that it combines the hierarchical clustering of context vectors with a previous step of dimensionality reduction that minimizes the effects of sampling errors.
Gender Equality and Maternal Burnout: A 40-Country Study
2022
International audience; In Western countries, recent decades have witnessed a revolution toward gender equality. Inequalities have been greatly reduced in areas such as education or employment. Because inequalities lead to distress, this development has largely benefited women. One notable exception is the realm of parenting, which has remained rife with inequalities even in the most egalitarian countries. We hypothesized that experiencing inequality in parenting when one holds egalitarian values and raising a child in a country characterized by a high level of gender equality in other areas, increases mothers’ psychological distress in the specific area of parenting. Multilevel modeling an…