University of Los Andes

About: University of Los Andes is a education organization based out in Bogotá, Colombia. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 17616 authors who have published 25555 publications receiving 413463 citations.

The benefits of exercise for patients with haemophilia and recommendations for safe and effective physical activity

Abstract: Most health care professionals involved in the management of people with haemophilia (PWH) believe that exercise is beneficial and its practice is widely encouraged. This article aims to demonstrate that appropriate exercise (adapted to the special needs of the individual PWH) may be beneficial for all PWH through improved physical, psychosocial and medical status. Based on evidence gathered from the literature, many PWH, particularly those using long-term prophylaxis or exhibiting a mild/moderate bleeding phenotype, are as active as their healthy peers. PWH experience the same benefits of exercise as the general population, being physically healthier than if sedentary and enjoying a higher quality of life (QoL) through social inclusion and higher self-esteem. PWH can also gain physically from increased muscle strength, joint health, balance and flexibility achieved through physiotherapy, physical activity, exercise and sport. Conversely, very little data exist on activity levels of PWH in countries with limited resources. However, regarding specific exercise recommendations in PWH, there is a lack of randomized clinical trials, and consequently formal, evidence-based guidelines have not been produced. Based on published evidence from this review of the literature, together with the clinical experience of the authors, a series of recommendations for the safe participation of PWH in regular physical activities, exercises and sport are now proposed. In summary, we believe that appropriately modified programmes can potentially allow all PWH to experience the physical and psychosocial benefits of being physically active which may ultimately lead to an improved QoL.

Occupational exposure to organophosphate and carbamate pesticides affects sperm chromatin integrity and reproductive hormone levels among Venezuelan farm workers.

Abstract: Objectives Several reports suggest that chronic pesticide exposure may affect semen quality and male fertility in humans. The objective of this study was to evaluate the association between occupational exposure to organophosphate (OP) and carbamate (CB) pesticides and semen quality, as well as levels of reproductive and thyroid hormones of Venezuelan farm workers. Methods Thirty-five healthy men (unexposed group) and 64 male agricultural workers (exposed group) were recruited for clinical evaluation of fertility status. Fresh semen samples were evaluated for sperm quality and analyzed for DNA fragmentation index (DFI) by flow cytometry. Pesticide exposure was assessed by measuring erythrocyte acetylcholinesterase (AChE) and plasma butyrylcholinesterase (BuChE) with a Test-mate ChE field kit. Serum levels of total testosterone (Tt), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), thyroid stimulating hormone (TSH) and free thyroxine (FT4) were analyzed using enzyme immunoassay kits. Results Evidence of pesticide exposure was found in 87.5% of farmers based on AChE and BuChE inhibition. Significant increments were observed in sperm DFI with significant decreases in some semen parameters. DFI was negatively correlated with BuChE, sperm concentration, morphology and vitality in these workers. The levels of Tt, PRL, FT4 and TSH appeared to be normal; however, there was a tendency for increased LH and FSH levels in exposed workers. Conclusions Our results confirm the potential impact of chronic occupational exposure to OP/CB pesticides on male reproductive function, which may cause damage to sperm chromatin, decrease semen quality and produce alterations in reproductive hormones, leading to adverse reproductive health outcomes.

Branch xylem density variations across the Amazon Basin

Abstract: Xylem density is a physical property of wood that varies between individuals, species and environments. It reflects the physiological strategies of trees that lead to growth, survival and reproduction. Measurements of branch xylem density, ρx, were made for 1653 trees representing 598 species, sampled from 87 sites across the Amazon basin. Measured values ranged from 218 kg m−3 for a Cordia sagotii (Boraginaceae) from Mountagne de Tortue, French Guiana to 1130 kg m−3 for an Aiouea sp. (Lauraceae) from Caxiuana, Central Para, Brazil. Analysis of variance showed significant differences in average ρx across regions and sampled plots as well as significant differences between families, genera and species. A partitioning of the total variance in the dataset showed that species identity (family, genera and species) accounted for 33% with environment (geographic location and plot) accounting for an additional 26%; the remaining "residual" variance accounted for 41% of the total variance. Variations in plot means, were, however, not only accountable by differences in species composition because xylem density of the most widely distributed species in our dataset varied systematically from plot to plot. Thus, as well as having a genetic component, branch xylem density is a plastic trait that, for any given species, varies according to where the tree is growing in a predictable manner. Within the analysed taxa, exceptions to this general rule seem to be pioneer species belonging for example to the Urticaceae whose branch xylem density is more constrained than most species sampled in this study. These patterns of variation of branch xylem density across Amazonia suggest a large functional diversity amongst Amazonian trees which is not well understood.

Software documentation issues unveiled

Abstract: (Good) Software documentation provides developers and users with a description of what a software system does, how it operates, and how it should be used. For example, technical documentation (e.g., an API reference guide) aids developers during evolution/maintenance activities, while a user manual explains how users are to interact with a system. Despite its intrinsic value, the creation and the maintenance of documentation is often neglected, negatively impacting its quality and usefulness, ultimately leading to a generally unfavourable take on documentation. Previous studies investigating documentation issues have been based on surveying developers, which naturally leads to a somewhat biased view of problems affecting documentation. We present a large scale empirical study, where we mined, analyzed, and categorized 878 documentation-related artifacts stemming from four different sources, namely mailing lists, Stack Overflow discussions, issue repositories, and pull requests. The result is a detailed taxonomy of documentation issues from which we infer a series of actionable proposals both for researchers and practitioners.