National Autonomous University of Nicaragua

About: National Autonomous University of Nicaragua is a education organization based out in Managua, Nicaragua. It is known for research contribution in the topics: Population & Public health. The organization has 775 authors who have published 715 publications receiving 9791 citations.

Investigating pesticide transport in the León-Chinandega aquifer, Nicaragua

Abstract: Nicaragua's Leon-Chinandega aquifer has seen extensive contamination by persistent organochlorine pesti- cides applied over decades of intensive agricultural activity. Models of flow and transport of a 330 km 2 sub-region of the aquifer were developed to test conceptual models of contaminant transport, to constrain the value of certain key transport parameters, and to investigate contamination- related concerns raised in past studies. To support these models, a variety of hydrogeologic and geochemical data were collected. It was concluded that the organochlorine pesticides seen in groundwater originate in soils, and are transported to the water table through widespread preferential flow, through shortcutting around wells, or through wind-blown particles delivered to poorly protected hand-dug wells. The distribution coefficient (Kd )o f these pesticides is estimated to be between 0.1 and 100 ml/g and the concentration of pesticides being delivered to the water table is estimated to be between 10 2 and 10 5 ng/L. It was found that the distribution and concentration of pesticides in the aquifer would be affected by an increase in groundwater abstraction within the region. Resume L'aquifere du Leon-Chinandega au Nicaragua a ete soumis a des contaminations etendues par des pesticides organochlores persistants qui ont ete repandus pendant des dizaines d'annees d'agriculture intensive. Des modeles d'ecoulement et de transport d'une sous- region de 330 km 2 de l'aquifere ont ete construits pour

Litterfall and nutrient dynamics shift in tropical forest restoration sites after a decade of recovery

Abstract: Author(s): Lanuza, Oscar; Casanoves, Fernando; Zahawi, Rakan A; Celentano, Danielle; Delgado, Diego; Holl, Karen D

Characterization of the gut microbiota of Nicaraguan children in a water insecure context

Abstract: OBJECTIVES The gut microbiota varies across human populations. The first years of life are a critical period in its development. While delivery mode and diet contribute to observed variation, the additional contribution of specific environmental factors remains poorly understood. One factor is waterborne enteric pathogen exposure. In this pilot study, we explore the relationship between household water security and the gut microbiota of children. METHODS From Nicaraguan households (n = 39), we collected drinking water samples, as well as fecal samples from children aged one month to 5.99 years (n = 53). We tested water samples for total coliforms (CFU/mL) and the presence of common enteric pathogens. Composition and diversity of the gut microbiota were characterized by 16S rRNA sequencing. Households were classified as having drinking water that was "low" (<29 CFU/mL) or "high" (≥29 CFU/mL) in coliforms. We used permutational analyses of variance and Mann-Whitney U-tests to identify differences in the composition and diversity of the gut microbiota of children living in these two home types. RESULTS Insecure access led households to store drinking water and 85% tested positive for coliforms. High concentrations of Salmonella and Campylobacter were found in water and fecal samples. Controlling for age, the gut microbiota of children from high coliform homes were compositionally different and less diverse than those from low coliform homes. CONCLUSIONS Results indicate that research exploring the ways water insecurity affects human biology should consider the gut microbiome and that investigations of inter-population variation in the gut microbial community of children should consider pathogen exposure and infection.

Leaf litter stoichiometry affects decomposition rates and nutrient dynamics in tropical forests under restoration in Costa Rica

Abstract: Active restoration strategies increase the production of leaf litter in tropical forests, but little is known about their effect on litter decomposition and subsequent nutrient release. We quantified changes in leaf litter stoichiometry during decomposition in former pasture sites under contrasting restoration strategies (natural regeneration, applied nucleation/islands tree planting and plantation), as well as in nearby primary forest. Litterbags were employed to evaluate decomposition. We used a leaf mixture of either the four planted tree species in the plantation and island treatments or the nearby primary forest and compared them under a factorial design. Decomposition rates were similar between restoration treatments (p > 0.5), but leaves decomposed faster in the forest mixture than in the plantation mixture (p < 0.01). The content of Ca, Mg, K, P, and the C:N ratio were higher in the forest mixture at the beginning and during decomposition (p < 0.05); the N content in the plantation mixture was higher at the beginning but lower during decomposition (p < 0.05), which meant greater mobilization of nitrogen per unit of carbon lost. K and P had a strong initial release, while Mg was released more gradually. N and Ca had an irregular pattern of initial fast release, immobilization, and re‐release in the later stages. We conclude that the differences in rates of decomposition and nutrient release in these systems under restoration were at least partly determined by the floristic heterogeneity and chemical quality of the leaf litter that reaches the soil.

First Identification and Description of Rickettsioses and Q Fever as Causes of Acute Febrile Illness in Nicaragua.

Abstract: Background Rickettsial infections and Q fever present similarly to other acute febrile illnesses, but are infrequently diagnosed because of limited diagnostic tools. Despite sporadic reports, rickettsial infections and Q fever have not been prospectively studied in Central America. Methodology/Principal Findings We enrolled consecutive patients presenting with undifferentiated fever in western Nicaragua and collected epidemiologic and clinical data and acute and convalescent sera. We used ELISA for screening and paired sera to confirm acute (≥4-fold rise in titer) spotted fever and typhus group rickettsial infections and Q fever as well as past (stable titer) infections. Characteristics associated with both acute and past infection were assessed. Conclusions/Significance We enrolled 825 patients and identified acute rickettsial infections and acute Q fever in 0.9% and 1.3%, respectively. Clinical features were non-specific and neither rickettsial infections nor Q fever were considered or treated. Further study is warranted to define the burden of these infections in Central America.