Search results for " shape"

Axiomatics and construction of the central place system

1987

The construction of the loschian landscape is a basic element in the Theory of Economic Regions. It is based on an hexagonal lattice and loschian numbers having properties used by DACEY (10,11,12,13) and MARSHALL (16,17,18,19,20). In fact, the former has not tested his model. In this paper our purpose is to prove that DACEY failed to build mathematically the Central Place System, and to propose a new method of construction of the loschian landscape.

Effect of oxidative stress on UDP-glucuronosyltransferases in rat astrocytes.

2012

WOS:000309170300003; International audience; The present work reports data regarding effects of an induced oxidative stress on the mainly expressed isoforms of UDP-glucuronosyltransferases (UGTs) in the brain. UGT1A6 and UGT1A7 expression and enzymatic activities toward the 1-naphthol were analyzed in rat cultured astrocytes following the exposure for 48 h to redox-cycling xenobiotic compounds such as quinones and bipyridinium ions. The expression of NADPH:cytochrome P450 reductase and NAD(P)H:quinone oxidoreductase 1 (NQO1) was also investigated. Oxidative stress induced significant deleterious changes in astrocyte morphology, decreased cell viability and inhibited catalytic function of UG…

Spermiogram and sperm head morphometry assessed by multivariate cluster analysis results during adolescence (12-18 years) and the effect of varicocele

2016

Artículo científico This work evaluates sperm head morphometric characteristics in adolescents from 12 to 18 years of age, and the effect of varicocele. Volunteers between 150 and 224 months of age (mean 191, n = 87), who had reached oigarche by 12 years old, were recruited in the area of Barranquilla, Colombia. Morphometric analysis of sperm heads was performed with principal component (PC) and discriminant analysis. Combining seminal fluid and sperm parameters provided five PCs: two related to sperm morphometry, one to sperm motility, and two to seminal fluid components. Discriminant analysis on the morphometric results of varicocele and nonvaricocele groups did not provide a useful class…

A new technique for analysis of human sperm morphology in unstained cells from raw semen

2014

Sperm morphology analysis is a fundamental component of semen analysis, but its real significance has been clouded by the plethora of techniques used for its evaluation. Most involve different fixation and staining procedures that induce artefacts. Herein we describe Trumorph (Proiser R+D, Paterna, Spain), a new method for sperm morphology analysis based on examination of wet preparations of spermatozoa immobilised, after a short 60°C shock, in narrow chambers and examined by negative phase contrast microscopy. A range of morphological forms was observed, similar to those found using conventional fixed and stained preparations, but other forms were also found, distinguishable only by the o…

Single mechano-gated channels activated by mechanical deformation of acutely isolated cardiac fibroblasts from rats

2010

Aim Mechanosensitive conductances were reported in cardiac fibroblasts, but the properties of single channels mediating their mechanosensitivity remain uncharacterized. The aim of this work was to investigate single mechano-gated channels (MGCs) activated by mechanical deformations of cardiac fibroblasts. Methods Currents through single MGCs and mechanosensitive whole-cell currents were recorded from isolated rat atrial fibroblasts using the cell-attached and whole-cell patch-clamp configurations respectively. Defined mechanical stress was applied via the patch pipette used for the whole-cell recordings. Results Under resting conditions occasional short openings of two types of single MGCs …

Sexual orientation predicts men’s preferences for sexually dimorphic face-shape characteristics: A replication study

2020

Many researchers have proposed that straight men prefer women’s faces displaying feminine shape characteristics at least partly because mating with such women will produce healthier offspring. Although a prediction of thisadaptation-for-mate-choicehypothesis is that straight men will show stronger preferences for feminized versus masculinized versions of women’s faces than will gay men, only one previous study has directly tested this prediction. Here we directly replicated that study by comparing 623 gay and 3163 straight men’s preferences for feminized versus masculinized versions of faces. Consistent with the adaptation-for-mate-choice hypothesis of straight men’s femininity preferences,…

Comparison of different statistical approaches to evaluate morphometric sperm subpopulations in men.

2016

This study was designed to characterize morphometric sperm subpopulations in normozoospermic men by using different statistical methods and examining their suitability to classify correctly different sperm nuclear morphologies present in human ejaculates. Ejaculates from 21 normozoospermic men were collected for the study. After semen collection and analysis, samples were prepared for morphometric determination. At least 200 spermatozoa per sample were assessed for sperm morphometry by computer-assisted sperm morphometry analysis (CASA-Morph) using fluorescence. Clustering and discriminant procedures were performed to identify sperm subpopulations from the morphometric data obtained. Cluste…

The Polysialylated Form of the Neural Cell Adhesion Molecule (PSA-NCAM) Is Expressed in a Subpopulation of Mature Cortical Interneurons Characterized…

2010

Principal neurons in the adult cerebral cortex undergo synaptic, dendritic, and spine remodeling in response to different stimuli, and several reports have demonstrated that the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) participates in these plastic processes. However, there is only limited information on the expression of this molecule on interneurons and on its role in the structural plasticity of these cells. We have found that PSA-NCAM is expressed in mature interneurons widely distributed in all the extension of the cerebral cortex and have excluded the expression of this molecule in most principal cells. Although PSA-NCAM expression is generally considered a …

Afterword to

2016

Cycloastragenol as an Exogenous Enhancer of Chondrogenic Differentiation of Human Adipose-Derived Mesenchymal Stem Cells. A Morphological Study

2020

Stem cell therapy and tissue engineering represent a promising approach for cartilage regeneration. However, they present limits in terms of mechanical properties and premature de-differentiation of engineered cartilage. Cycloastragenol (CAG), a triterpenoid saponin compound and a hydrolysis product of the main ingredient in Astragalus membranaceous, has been explored for cartilage regeneration. The aim of this study was to investigate CAG&rsquo