National University of Costa Rica
  • Heredia, Provincia de Heredia, Costa Rica
Recent publications
Epidemiological surveillance systems for pathogens in wild species have been proposed as a preventive measure for epidemic events. These systems can minimize the detrimental effects of an outbreak, but most importantly, passive surveillance systems are the best adapted to countries with limited resources. Therefore, this research aimed to evaluate the technical and infrastructural feasibility of establishing this type of scheme in Costa Rica by implementing a pilot program targeting the detection of pathogens of zoonotic and conservation importance in wildlife. Between 2018 and 2020, 85 carcasses of free-ranging vertebrates were admitted for post-mortem and microbiology analysis. However, we encountered obstacles mainly related to the initial identification of cases and limited local logistics capacity. Nevertheless, this epidemiological surveillance scheme allowed us to estimate the general state of health of the country's wildlife by establishing the causes of death according to pathological findings. For instance, 60% (51/85) of the deaths were not directly associated with an infectious agent. Though in 37.6% (32/85) of these cases an infectious agent associated or not with disease was detected. In 27.1% (23/85) of the cases, death was directly related to infectious agents. Furthermore, 12.9% (11/85), the cause of death was not determined. Likewise, this wildlife health monitoring program allowed the detection of relevant pathogens such as Canine Distemper Virus, Klebsiella pneumoniae, Angiostrongylus spp., Baylisascaris spp., among others. Our research demonstrated that this passive surveillance scheme is cost-effective and feasible in countries with limited resources. This passive surveillance can be adapted to the infrastructure dedicated to monitoring diseases in productive animals according to the scope and objectives of monitoring PLOS ONE PLOS ONE |
We consider the zero-range process with long jumps and in contact with infinitely extended reservoirs in its non-equilibrium stationary state. We derive the hydrostatic limit and the Fick’s law, which are a consequence of a static relationship between the exclusion process and the zero-range process. We also obtain the large deviation principle for the empirical density, i.e. we compute the non-equilibrium free energy.
The literature describes cases of boid inclusion body disease (BIBD) in captive snakes since the 1970s, and in the 2010s, others and ourselves identified reptarenaviruses as the causative agent. BIBD affects captive snakes globally, but the origin and the natural host of reptarenaviruses remain unknown.
Arsenic is a concern for its ubiquity in the environment and its accumulative and toxic properties. Water is often contaminated with this chemical, so developing simple, scalable, and green water treatment technologies is urgently needed. We show here that the ability of the L-Cysteine biomolecule to form complexes with arsenic inspires its use as a natural bio-inspired sorbent to develop advanced functional materials. We establish for the first time a way to chemically anchor L-Cysteine (L-Cys) inside highly hydrophilic nanofibers to create a membrane capable of lowering As(V) concentration below the WHO limit of 10 μg/L. A homogeneous precursor mixture of an aqueous solution of PVA and L-Cys (5 wt% and 10 wt% of L-Cys with respect to PVA) was electrospun to obtain a nanofibrous membrane. Successful immobilization of L-Cys within PVA nanofibers is achieved during heat treatment at 190 °C. It occurs through esterification reactions between the hydroxyl group on the PVA chain and the carboxylic acid on L-Cys. Arsenic sorption (as As(V)) was assessed by batch experiments in aqueous media and at a controlled pH range. The maximum removal efficiency was achieved at pH 7, supporting the formation of thiolate complexes as the primary mechanism for arsenic sorption. We show that L-Cys confinement makes arsenic diffusion inside the nanofibers a rate-limiting process in adsorption kinetics, following the pseudo first order equation. Overall, this work establishes a novel arsenic remediation strategy and encourages the research of nature-mimicking adsorbents and biodegradable polymers to develop functional materials in water remediation.
This article discusses Costa Rica’s policies and institutions created by the state to redistribute land during the 1960s and 1970s, when Latin American was implementing agrarian reforms. The paper also addresses the creation of the national parks system and forest conservation state policy supported by different scientific organisations during the same period. Within this context, this research seeks to explore the interface between the agrarian question (surrounding land and agrarian reform) and the ecological question (related to forest, national parks and conservation policies). The study examines how the transformations in land tenure and forest conservation have led to the structuring of a ‘new agrarian question’, which encompasses the concentration of land as well as the concentration of payments for environmental services.
Tropical wet forest plants experience relatively stable temperatures throughout the year. However, tropical forests represent a mosaic of habitats characterized by different temperatures. Heat tolerances are expected to be adapted to temperatures specific to their habitats. Although heat tolerance of species sharing similar environments are expected to be similar, it is also possible that heat tolerance is constrained by evolutionary history because closely related species usually display similar physiologies. When exotic species are introduced to novel communities, colonization may be facilitated by their previous adaptation to high temperatures and other physiological, genetic, and demographic traits, which may grant them some competitive advantage. Increasing temperatures may represent a strong environmental filter affecting community assembly, and higher heat tolerances could facilitate the persistence of exotic species in novel environments. Using a community of 32 native and 7 exotic Zingiberales species from different tropical habitats in Costa Rica, Central America, we aim to answer the following questions: a) does evolutionary history constrain heat tolerance? b) do plants in the same habitat display similar heat tolerances? c) do the heat tolerances of exotic species differ from those of native species? We measured temperature‐dependent changes in photosynthetic fluorescence to determine the temperature at which the first sign of damage to photosystem II is observed (T15), and the temperature at which the fluorescence of photosystem II is reduced by 50% (T50). Using a community phylogeny, we tested for phylogenetic signal in T15 and T50. In addition, we tested for differences in heat tolerance among Zingiberales from old growth, secondary forests, and open areas, as well as between native and exotic species. Our results support a) a significant phylogenetic signal (Pagel’s λ) for both T15 and T50, b) communities from open areas displayed similar photosynthetic heat tolerance compared to species from old growth and secondary forests, c) exotic Zingiberales are marginally tolerant to high temperatures than native species, but only for T15. Our results suggest that evolutionary history constraints heat responses of native and exotic Zingiberales in a warming world.
Mosquitoes are vectors of several arboviruses belonging to the genus Alphavirus and Flavivirus . Costa Rica is endemic for several arboviruses. To described and analyze the community structure of vectors in the country, a sampling was performed in two different coastal locations with evidence of arboviral activity during rainy and dry seasons. Encephalitis vector surveillance Traps, CDC Female Gravid Traps and ovitraps were used. Viral detection for several arbovirus was attempted. Blood-meal identification was also performed. A total of 1802 adult mosquitoes belonging to 55 species were captured. Culex quinquefasciatus was the most captured. species The Normalized Difference Vegetation Index (NDVI) was estimated for each area during rainy and dry season. The higher difference between seasonal regional NDVI yield lower values of Chao- Sørensen Similarity Index. Chao2 values and Shannon Index for species diversity were also estimated. There was no viral detection for VEEV, WNV, Madariaga. Dengue virus and Zika virus were detected in two separate Culex quinquefasciatus . The main sources of bloodmeal chickens (60%) and humans (27.5%). Both sampled areas have different seasonal dynamics and population turnover reflected in the Chao2 species richness estimation values and Shannon diversity Index. NDVI influence the mosquito diversity at a regional scale more than at a local scale. However, yearlong continuous sampling is required for a better understanding of local dynamics.
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3,805 members
Roberto A. Cordero
  • Escuela de Ciencias Biológicas
Marino Protti
  • Observatorio Vulcanológico y Sismológico de Costa Rica (OVSICORI)
Jorge Camacho
  • Posgrado Regional en Ciencias Verterinarias Tropicales
Bernal Morera
  • Escuela de Ciencias Biológicas
Maria Martinez Cruz
  • Observatorio Vulcanológico y Sismológico de Costa Rica (OVSICORI)
Calle 9, Avenidas 0 y 1, 3000, Heredia, Provincia de Heredia, Costa Rica
Head of institution
MEd. Francisco González Alvarado