Search results for " morphometry"
showing 10 items of 80 documents
Puma (Puma concolor) epididymal sperm morphometry
2016
The Andean puma (Puma concolor) has not been widely studied, particularly in reference to its semen characteristics. The aim of the present study was to define the morphometry of puma sperm heads and classify their subpopulations by cluster analysis. Samples were recovered postmortem from two epididymides from one animal and prepared for morphological observation after staining with the Hemacolor kit. Morphometric data were obtained from 581 spermatozoa using a CASA-Morph system, rendering 13 morphometric parameters. The principal component (PC) analysis was performed followed by cluster analysis for the establishment of subpopulations. Two PC components were obtained, the first related to …
Overlapping patterns of morphometric and genetic differentiation in the Mediterranean goby Pomatoschistus tortonesei Miller, 1968 (Perciformes, Gobii…
2012
Abstract. The genetic and morphological variations of Pomatoschistus tortonesei Miller, 1968 were studied in samples collected from three Tunisian lagoons. The morphological analysis included 18 morphometric measurements and was based on linear discriminant analysis (LDA), whereas the genetic analysis was based on the 16S-rRNA and COI mitochondrial genes. Both analyses differentiated the populations and demonstrated consistently a well-supported differentiation between the western Mediterranean samples (Bizerta and Tunis South lagoons) and the eastern Mediterranean sample (El Bibane lagoon). The observed differentiation could be explained in terms of the geographic isolation of the various …
Geometric morphometry supports a taxonomic revision of the Mediterranean Bathyporeia guilliamsoniana (Spence Bate, 1857) (Amphipoda, Bathyporeiidae)
2013
Bathyporeia guilliamsoniana (Spence Bate, 1857) specimens collected in the Levantine Basin of the Mediterranean Sea displayed polymorphism in some characters. More than 100 specimens were examined and their intra-specific variation in the shape of the third epimeral plate analysed and quantified. The morphometric geometry methodology is used to assess the ‘cryptic’ variation in shape which may obscure identification. The results support the assignment of sunnivae and megalops to morphotypes of B. guilliamsoniana sensu d’Udekem d’Acoz & Vader (2005).
Relationships between a new slope morphometric index and calanchi erosion in northern Sicily, Italy
2012
The Italian badlands, or “calanchi”, are common landforms in Mediterranean areas including central and southern Italy. Calanchi landforms may be compared to small hydrographic basins. These landforms are characterised by dense, hierarchical and rapidly evolving drainage systems carved into steep clayey slopes and by a sharply alternating pattern of furrows and narrow, generally sharp crests. This work presents a study of morphometric characteristics and a statistical analysis for two sites in northern Sicily (Italy), on outcrops of silty-clay deposits affected by active erosion processes, which give this area a typical calanchi landscape. In particular, factors closely linked to the charact…
Genetic structure of Triatoma venosa (Hemiptera: Reduviidae): molecular and morphometric evidence.
2006
Triatoma venosa presents a restricted geographical distribution in America and is considered as a secondary vector of Chagas disease in Colombia and Ecuador. A total of 120 adult insects were collected in domestic and peridomestic habitats in an endemic area of the department of Boyaca, Colombia, in order to determine their genetic structure through morphometric and molecular techniques. The head and wings of each specimen were used for the analyses of size, shape, and sexual dimorphism. A significant sexual dimorphism was found, although no differences in size among the studied groups were detected. Differences were found in the analyzed structures except for male heads. DNA was extracted …
Gyral and Sulcal Microsurgical Anatomy
2019
Abstract The complex set of sulci and gyri on the surface of the brain form a map with which neurosurgeons should be familiar when it comes to planning and carrying out their procedures, more particularly in the case of intrinsic brain lesions. Based on the general organization of the lobes and gyral convolutions of the brain, as defined by sulci and fissures, the pre- and intraoperative identification of the anatomical features of each patient is of critical importance. Knowledge of brain morphology is also essential to identify its different functional areas, given that both are closely associated. The correct interpretation of the excellent imaging techniques that are currently available…
Integrated neotectonic and morphometric analysis of northern Sicily
2006
Sicily is characterised by active deformations, as suggested by the presence of very recent faulted deposits and by widespread seismicity. The northern portion of the Sicilian belt has undergone strike-slip tectonics since the Pliocene, as the effect of the south Tyrrhenian border dynamics. Integrated methodologies of analysis have been utilised to evaluate the neotectonic setting of the northern sector of the island. To this aim, we have elaborated mesostructural, morphotectonic and morphometric data obtained from field survey, photogeological analysis and from the elaboration of digital elevation model (DEM) data relative to 31 drainage basins. The data sets have been compared with the up…
Testing the effects of pre-processing on voxel based morphometry analysis
2015
Voxel based morphometry (VBM) is an automated analysis technique which allows voxel-wise comparison of mainly grey-matter volumes between two magnetic resonance images (MRI). Two main analysis processes in VBM are possible. One is cross-sectional data analysis, where one group is compared with another to depict see the regions in the brain, which show changes in their grey-matter volume. Second is longitudinal data analysis, where MRIs, taken at different time points, are compared to see the regions in the brain that show changes in their grey matter volume for one time point with respect to another time point. Both types of analyses require pre-processing steps before performing the statis…
Effect of antipsychotic drugs on cortical thickness. A randomized controlled one-year follow-up study of haloperidol, risperidone and olanzapine.
2012
Abstract Background Imaging evidence indicates that brain alterations are primary to the full-blown onset of schizophrenia and seem to progress across time. The potential effects of antipsychotic medication on brain structure represent a key factor in understanding brain changes in psychosis. We aimed to investigate the effects of low doses of haloperidol, risperidone and olanzapine on cortical thickness. Method We investigated the effects of risperidone (N = 16), olanzapine (N = 18) and low doses of haloperidol (N = 18) in cortical thickness changes during 1-year follow-up period in a large and heterogeneous sample of schizophrenia spectrum patients. The relationship between cortical thick…
Vanadium Modulates Proteolytic Activities and MMP-14-Like Levels during Paracentrotus lividus Embryogenesis
2022
The increasing industrial use of vanadium (V), as well as its recent medical use in various pathologies has intensified its environmental release, making it an emerging pollutant. The sea urchin embryo has long been used to study the effects induced by metals, including V. In this study we used an integrated approach that correlates the biological effects on embryo development with proteolytic activities of gelatinases that could better reflect any metal-induced imbalances. V-exposure caused morphological/morphometric aberrations, mainly concerning the correct distribution of embryonic cells, the development of the skeleton, and the embryo volume. Moreover, V induced a concentration change …