University of Costa Rica
  • San José, Costa Rica
Recent publications
Long-life packaging is being used informally as an alternative to improve thermal insulation in single-family wooden houses. Its usage is backed by environmental concerns to reuse these solid residues as a radiant barrier for heat transmission. However, some published studies have only analyzed its thermal insulation efficiency, without considering the material performance in fire situations. Given this scenario, the objective of this research is to present the analysis and classification to a fire reaction of long-life packaging. In addition to the non-combustibility test, ignitability, radiant wall panel, optical smoke density and single burn item (SBI) tests were carried out. The results showed that the material is combustible and is classified as fire reaction class VI, according to the criteria for special materials. Thus, on the findings of this study, it can be concluded that long-life packaging should not be used as a lining for the internal surfaces of buildings.
This study aimed to automatically classify physical fitness and cardiometabolic risk in a Chilean adolescent using self-organizing maps. This cross-sectional study analysed a nationally representative database from the Physical Education Quality Measurement System (n = 7197). Physical fitness and cardiometabolic risk variables were derived from anthropometric indicators. Self-Organizing maps (SOM) were employed to identify participant profiles based on an unsupervised predictive model. After implementing and training the SOM, a detailed analysis of the generated maps was conducted to interpret the revealed relationships and clusters. The analysis resulted in three classification groups, categorizing the sample into low, moderate, and high-risk levels. Students with better physical fitness exhibited lower cardiometabolic risk levels and a lower body mass index. SOM, through an unsupervised model, is a reliable tool for classifying cardiometabolic risk and physical fitness in adolescents.
This article develops a phenomenological approach to examine the intersection of global migration and rising concerns about disinformation. Drawing on interviews with Venezuelans en route to the United States-Mexico border through Central America, the article analyzes how undocumented migrants live amid information precarity, how they relate to disinformation, and how disinformation affects their decisions. We demonstrate the centrality of information and communication practices in managing (dis)information during the migration experience. This includes distrusting traditional media, using various platforms like social media and messaging apps, and exchanging both information and disinformation with others. By adopting a phenomenological approach, the article demonstrates that migrants’ relationship with (dis)information is shaped by their conviction that each person has unique life experiences and a profoundly religious view of life and destiny. The article thus advocates for a deeper exploration of migrants’ sociocultural beliefs rather than focusing solely on issues such as information accuracy, accessibility, flows, and platforms when accounting for disinformation. In addition to valuable lessons for (dis)information studies, this approach could enrich communication interventions tailored to migrant communities in vulnerable conditions.
This chapter seeks to contribute to a better understanding of the variety and spatial unevenness of sustainability transitions by studying Chorotega’s regional transition from livestock farming to tourism, a process that has unfolded for over four decades. We argue that agency has been mobilised across actors in multiple scales. The national government and supranational organisations initiated the transformation through policies aligning economic growth with environmental conservation, while regional and local actors, including businesses and educational institutions, have been crucial to adapt the changes. To analyse the interplay of agency at various scales, the study employs sustainability transitions and economic geography frameworks to identify how macro- and micro-level agencies influenced the initiation, evolution, and establishment of an industry that has prompted a sustainability transition in the region. Despite the green and sustainable image of Costa Rica, this chapter highlights the contradictions and limitations that sustainability transitions can face. Indeed, economic vulnerability, social inequalities, and environmental challenges persist, suggesting a need for a vision that centres around environmental and social challenges.
Climate change, inter‐annual precipitation variability, recurrent droughts and flash flooding, coupled with increasing water needs, are shaping the co‐evolution of socioeconomic and cultural assemblages, water laws and regulations, and equitable drinking water access and allocation worldwide. Recognising the need for mitigation strategies for drinking water availability in urban areas, the Isotope Hydrology Section of the International Atomic Energy Agency (IAEA) coordinated a state‐of‐the‐art global assessment to evaluate water sources and distribution of drinking water supply in urban centres, an initiative entitled ‘Use of Isotope Techniques for the Evaluation of Water Sources for Domestic Supply in Urban Areas (2018–2023)’. Here, we report on (a) current research trends for studying urban drinking water systems during the last two decades and (b) the development, testing and integration of new methodologies, aiming for a better assessment, mapping and management of water resources used for drinking water supply in urban settings. Selected examples of water isotope applications (Canada, USA, Costa Rica, Ecuador, Morocco, Botswana, Romania, Slovenia, India and Nepal) provide context to the insights and recommendations reported and highlight the versatility of water isotopes to underpin seasonal and temporal variations across various environmental and climate scenarios. The study revealed that urban areas depend on a large spectrum of water recharge across mountain ranges, extensive local groundwater extraction and water transfer from nearby or distant river basins. The latter is reflected in the spatial isotope snapshot variability. High‐resolution monitoring (hourly and sub‐hourly) isotope sampling revealed large diurnal variations in the wet tropics (Costa Rica) (up to 1.5‰ in δ ¹⁸ O) and more uniform diurnal variations in urban centres fed by groundwater sources (0.08‰ in δ ¹⁸ O) (Ljubljana, Slovenia). Similarly, while d ‐excess was fairly close to the global mean value (+10‰) across all urban centres (10‰–15‰), reservoir‐based drinking water systems show lower values (up to ~ −20‰) (Arlington, TX, USA and Gaborone, Botswana), as a result of strong evapoconcentration processes. δ ¹⁸ O time series and depth‐integrated sampling highlighted the influence of the catchment damping ratio in the ultimate intake water composition. By introducing new, traceable spatial and temporal tools that span from the water source to the end‐user and are linked to the engineered and socio‐economic structure of the water distribution system, governmental, regional or community‐based water operators and practitioners could enhance drinking water treatment strategies (including more accurate surface water blending estimations) and improve urban water management and conservation plans in the light of global warming.
Relatively little is known about the unique needs and issues faced by transgender men and their self-care practices during gender transition. This study aimed to analyse self-care practices during gender transition through the life histories of a group of Costa Rican transgender men. A qualitative study with a sociohistorical design employing a thematic life history approach was conducted with fourteen participants between April and September 2022. Data were analysed using Content Analysis. Three categories were developed concerning self-care: (i) the shaping of self-care practices throughout different life stages; (ii) self-care practices related to masculinising the body; and (iii) self-care practices on the margins of a cisheteronormative society. The identified self-care practices took place with the goal of materialising men’s gender identity socially, legally and medically. While self-care plays a key role in supporting individuals throughout the transition process, it is limited in its capacity to ensure comprehensive well-being. The social prejudice and violence encountered by transgender men poses a challenge to achieving full well-being. External pressures and adversities limit the effectiveness of self-care practices, highlighting the need for broader systemic change to enhance the overall health and wellness of transgender men in Costa Rica.
Drought and tropical cyclones (TCs) are among the deadliest and costliest natural hazards, and they are expected to intensify in the twenty-rst century because of anthropogenic climate change. The Hurricane Region of the Americas (HRA), an area often impacted by TCs and drought of the Americas, hosts some of the most vulnerable countries to these hazards and climate change worldwide. While TCs and drought have been extensively studied separately, there is little research on their interplay in the HRA, especially in areas without quality, long climate data. Here, we analyze the effects of TCs on drought characteristics (e.g., severity and duration) in the HRA between 1985 and 2023 using high-resolution gridded climate data and an array of drought metrics. Our results yield the rst-of-its-kind estimate of the interplay between TCs and drought across the entire HRA. We nd that, while TCs contribute to 4-15% of annual and seasonal mean precipitation across the region, on average, they ameliorated or terminated drought (e.g., an improvement of at least one drought rank on each metric) at least once in ~ 60% of the HRA in a single month in 1985-2023 (averaged estimates from all drought metrics). We suggest an appropriate analysis of TC-drought interactions should consider several drought metrics, even if sophisticated land-surface models are used.
This study analyzed gender differences in the psychophysiological factors of stress and academic performance among university students. A cross-sectional design was employed with a sample of 601 university students (74.7% women) aged 15 to 47 years. Participants completed assessments on sleep quality, heart rate variability (HRV), personality traits, and psychological indicators such as anxiety, depression, and perceived stress. Results showed that women exhibited higher levels of neuroticism, anxiety, psychological inflexibility, and perceived stress compared to men, yet achieved better academic performance. Regression analysis revealed that sleep quality and HRV parameters, such as heart rate (HR) and the square root of the mean squared differences of successive NN intervals (rMSSD), were positively associated with academic achievement. Despite higher stress levels, female students seemed to employ more effective emotional regulation strategies, contributing to their academic success. These findings highlight the need for gender-sensitive approaches in stress management interventions to improve student well-being and academic outcomes. Future research should consider longitudinal designs to explore the temporal dynamics of stress and academic performance.
The aim of this chapter is to follow a path through interstices and intersections, in which communities can be problematized as territories in dispute and transformation, woven from daily actions that account for the meaning of community life, and considering affections, resistances, conflicts, psychosocial damage, collective suffering, and marginalization processes. All this within a context marked by neoliberalism and the prioritization of capital accumulation. We understand Decolonial Community Psychology as a praxis of continuities and struggles, which questions forms of domination and extraction, that brings depth to the liberatory effort, that empowers popular virtues, commits to the capacity for transformation and recovers the current forms of struggle to resist domination and exclusion.
Tomato spotted wilt virus (TSWV) is an orthotospovirus that infects both plants and insect vectors. Understanding the protein localization and interactions is crucial for unraveling the infection cycle and host-virus interactions. We investigated and compared the localization of TSWV proteins. A change in localization over time was associated with the viral proteins that did not contain signal peptides and transmembrane domains such as N, NSs and NSm, however, this only occurred in the plant cells, not in the insect cells. The localization between plants and insects otherwise was consistent indicating a similar mechanism is utilized by the virus in both types of cells. We also tested the localization of the proteins during an active plant infection using free RFP as a marker to highlight the nucleus and cytoplasm. Voids in the cytoplasm were shown only during infection and N, NSs, NSm and to lesser extent, G N and G C , were surrounding these areas suggesting it may be a site of replication or morphogenesis. Furthermore, we tested the interactions of viral proteins using both bimolecular fluorescence complementation (BiFC) and membrane-based yeast two-hybrid (MbY2H) assays. These revealed self-interactions of NSm, N, G N , G C , and NSs. We also identified interactions between different TSWV proteins, indicating their roles and host interactions, such as between NSs and G C and N and G C which may be necessary during the replication and assembly processes respectively. This research expands our knowledge of TSWV infection and elaborates on the intricate relationships between viral proteins, cellular dynamics, and host responses.
Identification of the geographic origin of invasive species can be critical to effective management and amelioration of negative impacts in the introduced range. Liriomyza huidobrensis is a polyphagous leafmining fly that is a devastating pest of many vegetable and floriculture crops around the world. Considered native to South and possibly Central America, L. huidobrensis became invasive in the 1980s and has since spread to at least 30 countries on five continents. We used phylogeographic analysis of over 2 kb of mitochondrial cytochrome oxidase I and II sequence data from 403 field‐collected specimens from both native and introduced populations to investigate the geographic origins of invasive L. huidobrensis worldwide. Within South America, there was substantial genetic variation, as well as the strong phylogeographic structure typical of a native range. In contrast, leafminers from the introduced range and Central America all contained little genetic variation and shared the same small set of haplotypes. These haplotypes trace to Peru as the ultimate geographic origin of invasive populations. Central America is rejected as part of the original geographic range of L. huidobrensis. Within Peru, the primary export region of Lima shared an extremely similar pattern of reduced haplotype variation to the invasive populations. An additional 18 specimens collected at US ports of entry did not share the same haplotype profile as contemporary invasive populations, raising perplexing questions on global pathways and establishment success in this species.
This study examines the relationship between subjective well-being in the workplace and organizational productivity through a systematic review of relevant scientific articles. A systematic review was conducted on 310 articles, employing inclusion and exclusion criteria to narrow it down to 36 pertinent articles. The review identified several factors affecting both subjective well-being and productivity, such as the company’s willingness to implement programs to improve well-being prioritizing friendly working conditions, fair compensation, flexible schedules, a respectful work environment, promotion of professional development, and emotional and economic incentives. Keywords: subjective well-being; labor productivity; organizations; quality of life; job satisfaction.
Resumo Morar em um lar sempre foi uma necessidade do ser humano. Nele, se desenvolvem os microuniversos do ser e da sua sociabilidade, portanto, colocar em risco esse confortável habitat é ferir o bem-estar físico, mental e social das pessoas que o habitam. A pandemia disseminada mundialmente pelo vírus SARS-CoV-2, conhecido como covid-19, reflete as necessidades e desigualdades pré-existentes nos níveis social, econômico, político e cultural de todos os países do mundo. Essa situação de crise sanitária é a motivação para rever e refletir sobre o espaço habitado, reconhecendo os aspetos que envolvem a utilização da habitação, a adaptação e os impactos da habitabilidade devido à pandemia no estado de saúde dos indivíduos que nela vivem. A discussão exploratória se desenvolve no marco do seminário de habitação pós-pandemia no contexto colombiano da pandemia de covid-19 e suas implicações nos modos de vida da habitação e da cidade nos permite refletir e apresentar as várias abordagens e conclusões tiradas de pesquisas recentes que expõe a importância da relação do morador com sua casa em termos de saúde pública e habitabilidade, que se configura de acordo com as condições sociais impostas pela atual crise sanitária.
This study investigates the adsorption of methylene blue (MB) and methyl orange (MO) dyes from aqueous solutions using purified Moroccan bentonite, being mainly composed of silica and alumina, in the form of quartz and cristobalite. The temperature controls the adsorption capacity for the kinetics, increasing 5.08% (from 295.1 to 310.1 mg/g) for the MB and 55.47% (from 86.8 to 134.9 mg/g) for the MO. It was discovered that the pseudo-second-order model, with a low Bayesian criterion indicator of 12.72 and R²adj > 0.996, was the best suitable for explaining both systems. The adsorption isotherm, experimental data indicate that both systems follow the Langmuir isotherm. At lower temperatures, 298.15 K 1.22 molecules are adsorbed per site. However, at a higher temperature of 328.15 K, the number of molecules is less than a unit of 0.68. As for MO, the number of molecules remains above 1.4 per site for all the temperatures studied. The endothermic nature of the system is indicated by the observation that the adsorption energy tends to grow for both systems: for the MB, it increases from 18.85 to 21.26 kJ/mol, and for the MO, it increases from 14.83 to 19.01 kJ/mol. Last, thermodynamic functions indicate that maximum entropy is reached around the half-concentration saturation at 25 and 124 mg/L, which is the maximum energetic concentration of the system. The same results were obtained for Gibbs free energy, where the maximum energy found was − 5.39 × 10⁻¹⁸ kJ/mol for the MB and − 1.99 × 10⁻¹⁸ kJ/mol for the MO at 328.15 K.
In this work, starch-based porous cryogels with controlled mechanical and electrical properties were prepared for tissue engineering applications. The starch cryogels were formulated using κ-carrageenan, poly(vinyl alcohol) (PVA), and styrylpyridinium-substituted PVA (SbQ) into the composite. A conductive cryogel was polymerized by chemical oxidation of 3,4-ethylenedioxythiophene (EDOT) using iron(III) p-toluenesulfonate as a strategy to control the electrical properties. The physical, thermal, and mechanical properties were evaluated for the obtained composites. Macro- and nanoscale results confirmed the capability of tuning the mechanical properties of the material by the addition of biopolymers in different contents. The presence of κ-carrageenan significantly increased the storage modulus and decreased the damping effect in the formulations. The presence of PVA showed a plasticizing effect in the formulations, confirmed by the buffering effect and an increase in storage modulus. PVA-SBQ improved the mechanical properties by cross-linking. The addition of PEDOT increased the mechanical and electrical properties of the obtained materials.
Studies for the preservation of seagrass beds biotopes have met difficulties in establishing appropriate methods assessing their health. We tested the efficiency of space occupation by seagrasses scattered worldwide (dgrass index), which proved to be dependent on clonal growth form and morphometric plasticity. dgrass correlated with the above-ground to below-ground biomass ratio. However, the latter was misleading when high ratios resulted from low below-ground biomass. Nutrient Posphate-limitations were revealed in situations of theoretical Nitrogen-limitation. Enhanced nutrient supply benefitted seagrasses only up to a threshold after which it became detrimental. Better nurtured, healthier meadows with denser canopies increased the organic matter in the sediment and had associated greater abundances of benthic macrofauna. Hence, seagrass biotopes could benefit from moderate anthropogenic nutrient additions. However, organic matter above ≈6% and/or reduced riverine discharges (dams upstream and climate-change-related droughts) were detrimental to healthy meadows, jeopardizing ecosystem services such as macrofauna abundances and carbon sinks.
The aim of this investigation was to evaluate the effect of etching protocols on bond strength, surface roughness, and mechanical properties of a zirconia-reinforced lithium silicate (ZLS) CAD/CAM-ceramic. In total, 100 bars (ISO 6872), 75 plaques, and 25 cubes were cut from ZLS blocks(Vita Suprinity®). The surfaces were standardized, crystallized and divided into five groups: 1. control (no/treatment-C), 2. 5%-Hydrofluoric-acid (HF)/20 s (HF5%20s), 3.HF5%60s, 4.HF10%20s, and 5.HF10%60s. Flexural strength (FS) (three-point bending test, 1 mm/min), roughness (Pa), and micro-shear bond-strength (µSBS) tests were performed. The data were statistically analyzed with one-way ANOVA, Tukey’s test (p ˂ 0.05) and Weibull (FS data). C showed higher Pa (1.176 ± 0.370 µm) than HF10%60s (0.627 ± 0.236 µm) and all other groups. Groups C and 20 s showed the most irregular surface patterns. The FS results were not influenced by etching protocols, while the Weibull modulus was, with the 5%HF groups being the most reliable (m: 5.63/6.70), while C and HF10%60s (m: 2.78/2.73) were the least reliable. All fractures originated from surface defects on the treated side of specimens. The 5%HF groups showed higher µSBS (20 s: 21.35 ± 4.70 MPa; 60 s: 23.50 ± 4.27 MPa) than the 10%HF groups (20 s: 14.51 ± 2.47 MPa; 60 s: 16.54 ± 3.12 MPa) and C (6.46 ± 2.71 MPa). The most prevalent failure pattern was “mixed” for etched groups, and “adhesive” for C. Etching protocols affect the evaluated properties by roughening materials’ surface and, in some cases, regularizing surface defects. The best overall outcomes were achieved when applying 5%HF.
Marine turtles are a group of imperiled marine megafauna particularly vulnerable to anthropogenic stressors. Most long‐term studies of marine turtles are based on nesting surveys which focus on numbers of eggs, hatchlings, and nesting females. However, we know less about long‐term abundance trends of immature and adult turtles in the marine environment. To address this data gap, we examined records from 35,000 underwater visual census (UVC) dives (1993–2019) and short‐term in‐water turtle survey data (2009–2014) at Cocos Island, Costa Rica. During UVCs, trained divemasters from UnderSea Hunter recorded observations of two species of marine turtles—green Chelonia mydas and hawksbill Eretmochelys imbricata. Our short‐term in‐water surveys revealed that most turtles at Cocos are greens, but both immature and mature greens occur at Cocos. We analyzed long‐term UVC data using a hierarchical modeling approach and we modeled a 26% decrease in the relative abundance of turtles observed on dives each year. Our model also revealed potential interactions between tiger sharks and turtles, finding that for each additional tiger shark present during a dive, the predicted relative abundance of turtles decreased by 43%. Lastly, our model suggested the influence of environmental variation on marine turtle relative abundance; a 1°C increase in sea surface temperature (SST) decreased the predicted relative abundance of turtles by 7%. Our results suggest that marine turtles are sensitive to long‐term environmental and oceanographic changes, and potentially avoid certain areas to reduce exposure to tiger sharks. Given our study area is already protected, there needs to be more focus on protecting adult turtles during their movements across the Eastern Tropical Pacific. Our work also highlights the importance of long‐term underwater surveys to monitor adult turtles.
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14,388 members
Mariangela Vargas
  • Instituto Clodomiro Picado (ICP)
Alejandra M. Rojas González
  • Escuela de Ingeniería de Biosistemas
Alejandro Chacon
  • Estación Experimental de Ganado Lechero Alfredo Volio Mata (EEAVM)
Ricardo Radulovich
  • Department of Biosystems Engineering
Daniel Chavarria-Bolaños
  • Departamento de Ciencias Diagnósticas y Quirúrgicas
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San José, Costa Rica
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Carlos Araya Leandro