arXiv subjects

Joan Nieves

Publications and source records attributed to Joan Nieves.

3 recordsLinked to original sources

arXiv2026

Face morphometric profiles of groups as early markers for certain diseases?

Background: Face morphometry has been shown to work as a diagnosis tool in a set of syndromes. Face similarities are usually indications of more complete genetic similarities. Purpose: To show preliminary results on the face morphometry profile of the Cuban population and to argue that it could be used to define early markers for diseases, like Alzheimer. Methods: A dataset composed of photos of 200000 men is processed. Facial landmarks are extracted by means of the DLIB library and distances between them are computed. By clustering samples with similar facial traits, groups are formed and their densities inside the population are computed. Results: The face morphometry profiles for two age cohorts are obtained, showing the population dynamics. Genes involved in facial development are shown to be related to Alzheimer's disease. Conclusions: Late multifactorial diseases develop against the genetic background of each individual, which is expressed by its face morphometry. The latter can be thus considered a risk marker.

q-bio.PE↗

arXiv2023

Average fold-change of genetic pathways in biological transitions

A biological transition from a state N to a state T is characterized by a rearrangement of the gene expression profile in the system, quantitatively measured through the differential expression of genes. In contrast, changes in genetic pathways are usually evaluated by means of hypothesis testing schemes. We introduce a quantitative measure in order to evaluate the average fold-change of genetic pathways in biological transitions and applied it to characterize in general grounds the transition from a normal tissue to a tumor. Additionally, we study the transformation from primary to metastatic melanoma. Gene expression data from the TCGA portal for 16 tumors and the Reactome compilation of pathways are used for this purpose.

q-bio.TO↗

arXiv2020

Gene expression rearrangements denoting changes in the biological state

In many situations, the gene expression signature is a unique marker of the biological state. We study the modification of the gene expression distribution function when the biological state of a system experiences a change. This change may be the result of a selective pressure, as in the Long Term Evolution Experiment with E. Coli populations, or the progression to Alzheimer disease in aged brains, or the progression from a normal tissue to the cancer state. The first two cases seem to belong to a class of transitions, where the initial and final states are relatively close to each other, and the distribution function for the differential expressions is short ranged, with a tail of only a few dozens of strongly varying genes. In the latter case, cancer, the initial and final states are far apart and separated by a low-fitness barrier. The distribution function shows a very heavy tail, with thousands of silenced and over-expressed genes. We characterize the biological states by means of their principal component representations, and the expression distribution functions by their maximal and minimal differential expression values and the exponents of the Pareto laws describing the tails.

q-bio.QM↗