ABSTRACT
Sexual differences in the index to ring finger length ratio (2D:4D ratio) have been observed since more than 150 years ago, and they are already present in the foetus. Homeobox genes, which also control the differentiation of testes and ovaries, are involved in finger conformation, which is subjected to the influence of testosterone and estrogen levels. In general, women show larger 2D:4D digit ratios, although differences between sexes are subjected to ethnic variations. This study was performed in order to analyse the absolute values of several digit ratios (2D:4D; 4D:3D; 2D:3D) among 164 young adults of Tenerife (101 women). Finger lengths were directly measured dorsally using a calliper with an accuracy level of 0.01 mm. Dorsal digit lengths were defined as the distance between the fingertip and the dorsal base of the proximal phalanx, in a position in which fingers and palms formed an angle of 90º. We found that 2D:4D of both hands (for instance, women=0.9631 ± 0.02647; men= 0.9535 ± 0.02507 for the left 2D:4D ratios), the left 2D:3D (0.9063 ± 0.02216 in women; 0.8980 ± 0.01931 among men) and the right 4D:3D ratios (0.9377 ± 0.03625 among women vs 0.9471 ± 0.02138 among men) were significantly different among men and women. The magnitude of the difference among sexes is similar to that reported for other populations, and they allow for the elaboration of a discriminant function with an accuracy of 60.4%, that reaches 86% if stature is also included. We applied this discriminant function to a test group composed of 36 randomly selected women and 24 men, obtaining an accuracy of 58.33% and 81.67%, respectively
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Subject(s)
Humans , Male , Female , Adolescent , Young Adult , Adult , Radio , Sex Characteristics , Body Mass Index , Fingers/anatomy & histology , Body Weights and Measures , Fingers/growth & development , Sex Determination by Skeleton , Weight by Height/physiology , Spine/physiology , Multivariate Analysis , Fingers/physiology , Logistic Models , Anthropometry , Sex Determination by Skeleton/methodsABSTRACT
Sex estimation based on tibial measurements can be achieved using discriminant functions combining several parameters. However, functions differ from one population to another, because sexual dimorphism may be more or less marked among different ancestry or ethnic groups. Calculation of one of these functions with the dimensions of populations other than that from which the function was obtained may misclassify a different proportion of males or females than when calculated with the dimensions of the original population. By dividing the proportions of correctly classified individuals when the function was applied to the population from which it derived and that of El Hierro (Canary Islands), we can calculate an index of male trait expression and an index of female trait expression, and, by addition of both indices, an index of sexual dimorphism. Therefore, it is possible to compare the degree of sexual dimorphism among several populations, at least regarding those measurements included in the function. Based on this fact we have calculated several functions (reported in the scientific literature), obtained from tibiae of modern black, white, and Japanese populations, and from medieval Croatians and prehispanic inhabitants of Gran Canaria (ap. 1000 BP), with the dimensions of the prehispanic population of El Hierro, genetically sexed, also with an antiquity of ap. 1000 BP. Despite the different antiquity, the population of El Hierro was more dimorphic that the modern Japanese one, but less dimorphic than most of the other groups with which it was compared, especially when functions including distal epiphyseal breadth and minimum shaft perimeter (near the distal end of the tibiae) were calculated: in these cases, dimorphism was lower for the population of El Hierro, due to the fact that, although male trait expression index was higher, many females of El Hierro were misclassified as males because of the abnormally thick distal diaphyseal and epiphyseal breadths of El Hierro inhabitants
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Subject(s)
Humans , Sex Characteristics , Sex Differentiation , Tibia/anatomy & histology , Forensic Anthropology/methods , Ethnicity , Osteology/methods , Sex Determination by Skeleton/methodsABSTRACT
Hydrocephalus is an accumulation of cerebrospinal fluid (CSF) with dilatation of brain ventricles which can be either communicating or non-communicating. Multiple pathophysiological mechanisms underlie the appearance of hydrocephalus, which has many different causes including birth defects, brain hemorrhage, infection, meningitis, tumor, or head injury. The choroid plexuses (ChP) are circumventricular structures closely related to the above-mentioned pathophysiological mechanisms of the CSF, and aquaporin-1 (AQP1) is the water channel directly implicated in CSF production. Our studies with hydrocephalic rats revealed an increase and redistribution of AQP1 in the ChP, with AQP1 being expressed not only in the cell apical pole, but also in the cell basal pole and in the stroma. The immunohistochemical changes observed in both communicating and non-communicating hydrocephalus suggest a variation in the efficiency of the cells of the ChP, where AQP1 could perform both CSF production and reabsorption in order to delay ventricular dilatation
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