Gene and genome duplication.

Genomic sequencing projects have revealed the productivity of processes duplicating genes or entire chromosome segments. Substantial proportions of the yeast, Arabidopsis and human gene complements are made up of duplicates. This has prompted much interest in the processes of duplication, functional divergence and loss of genes, has renewed the debate on whether an early vertebrate genome was tetraploid, and has inspired mathematical models and algorithms in computational biology.

Evidence of peripheral auditory activity modulation by the auditory cortex in humans.

At the auditory periphery, the medial olivocochlear system is assumed to be involved in complex sound processing and may be influenced by feedback from higher auditory nuclei. Indeed, the descending auditory pathway includes fibers coming from the auditory cortex that are anatomically well positioned to influence the superior olivary complex, and thus the medial efferent system. The aim of the present study was to verify the hypothesis of an implied influence of the auditory cortex on the peripheral auditory system.

[The overall nutritional quality of the diet is reflected in the growth of Nigerian children].

Childhood malnutrition is widespread in the Sahel region of Africa. In Niger, the 1992 Population and Health Survey found that 32% of children under the age of five years had stunted growth and 16% had muscle wasting. Vitamin A deficiency and anemia are major health problems and it is thought that the rate of zinc deficiency is also high.