Biomedical subjects

A Tessari

Publications and source records attributed to A Tessari.

3 recordsLinked to original sources

PubMed2002

[Alteration of spermatogenesis and Y chromosome microdelations. Analysis of the DAZ gene family].

The Y chromosome has a fundamental role in sex determination and regulation of spermatogenesis. Three regions (designated as AZFa, b, and c) on the long arm of this chromosome exist, deletions of which result in severe damage to spermatogenesis with azoospermia or severe oligozoospermia. Recent progresses in molecular biology and extraordinary development of assisted reproduction techniques contributed to the research on this chromosome and the genes involved in spermatogenesis. About 10-15% of subjects affected by azoospermia or severe oligozoospermia carry a deletion in one or more AZF regions, 60% of which involves AZFc. The genes responsible for the testicular phenotype observed in these subjects are DBY and USP9Y for AZFa, RBMY1 for AZFb, and DAZ for AZFc. In this article, the current knowledge on biology and genetics of the Y chromosome are reported with particular interest to deletions found in infertile subjects. Furthermore, the more recent advances on DAZ gene and its role in spermatogenesis and male infertility are discussed.

Animals↗

PubMed2001

Hemispheric specialization in quantification processes.

Three experiments were carried out to study hemispheric specialization for subitizing (the rapid enumeration of small patterns) and counting (the serial quantification process based on some formal principles). The experiments consist of numerosity identification of dot patterns presented in one visual field, with a tachistoscopic technique, or eye movements monitored through glasses, and comparison between centrally presented dot patterns and lateralized tachistoscopically presented digits. Our experiments show left visual field advantage in the identification and comparison tasks in the subitizing range, whereas right visual field advantage has been found in the comparison task for the counting range.

Adult↗

PubMed1995

Remembering spatial locations: effects of material and intelligence.

The aim of the present work was to test some of the criteria for automaticity of spatial-location coding claimed by Hasher and Zacks, particularly individual differences (as intelligence invariance) and effortful encoding strategies. Two groups of subjects, 15 with mental retardation (Down Syndrome, mean chronological age, 20.9 yr.; mean mental age, 11.6 yr.) and 15 normal children (mean age, 11.5 yr.), were administered four kinds of stimuli (pictures, concrete words, nonsense pictures, and abstract words) at one location on a card. Subsequently, subjects were presented the items on the card's centre and were required to place the items in their original locations. Analysis indicated that those with Down Syndrome scored lower than normal children on the four tasks and that stimuli were better or worse remembered according to their characteristics, e.g., their imaginability. Results do not support some of the conditions claimed to be necessary criteria for automaticity in the recall of spatial locations as stated by Hasher and Zacks.

Adolescent↗