Universidad de Costa Rica

Vocalizations shape roost defence outcomes in a solitary bat

Individuals commonly compete with others that share their ecological niche, both within and among species. To avoid physical confrontations, individuals can use various types of signals to demonstrate their dominance, including vocalizations. Kerivoula hardwickii is a solitary ba...

First records of benthic resting behaviour in the Pacific eagle ray Aetobatus laticeps from the eastern Pacific Ocean

Species can still surprise us with behaviours not previously documented. The Pacific eagle ray (Aetobatus laticeps) had not been seen exhibiting resting behaviour before, but recently, recreational divers in Costa Rica and Mexico documented three individuals remaining stationary...

Almost Congruent Triangles: Geometry, Arithmetic, and Generalizations

We characterize pairs of noncongruent triangles having the same three angle measures and twoequal, noncorresponding side lengths, and study their primitive integer parametrizations, finite chains,and asymptotic counting laws. The golden ratio governs the admissible geometric rang...

Plasmidomics: studying plasmids as ecological entities beyond their hosts

Plasmids are mobile genetic elements with autonomous replication, whose ecology extends beyond individual bacterial hosts. As molecular symbionts, they have the potential to traverse bacterial taxa and environments, disseminating adaptive genes and shaping microbial community str...

Beta-Logistic Weil Kernels, Spectral Localization, and Signed Short-Interval Reductions

We study beta-logistic test kernels for the Weil explicit formula, focusing on uniform localization, signed arithmetic errors, and their relationship to zeros of the Riemann zeta function. We distinguish classical positivity and one-sided Laplace principles from kernel-specific c...

Body weight perception and body self-esteem in adolescents with overweight or obesity in Costa Rica: challenges for public health policy

ABSTRACT Objective: This study estimates the prevalence of weight misperception among Costa Rican adolescents in general and examines its association with body esteem and weight-control behaviors to inform public health policy. Methods: The authors analyzed cross-sectional data c...

A family of small proteins links c-di-GMP riboswitch signaling with sporulation in Clostridioides difficile

Abstract Cyclic diguanosine monophosphate (c-di-GMP) is a second messenger that coordinates lifestyle transitions, virulence, and developmental processes in bacteria. In Clostridioides difficile , elevated c-di-GMP levels inhibit sporulation, but the underlying mechanism remained...

No constituency for universal basic income? Evidence from seven Latin American countries

Abstract Despite the expansion of non-contributory cash transfer programmes in Latin America – especially during the COVID-19 pandemic – public support for a universal basic income (UBI) remains remarkably low. Using original survey data from seven countries, we find that fewer t...

Lack of Natural Seagrass Recovery at a Site in the Eastern Tropical Pacific Reveals the Need for Active Ecological Restoration

Seagrass meadows provide many ecosystem services, but by virtue of anthropogenic pressures, they are also highly threatened habitats. In the Eastern Tropical Pacific, a seagrass meadow disappeared in 1996 following a severe storm at Bahía Culebra, northern Pacific coast of Costa...

Implementation of NIRS Spectroscopy in Predictive Models for Organic Matter Fractionation in Volcanic Soils

The fractionation of soil organic matter (SOM) and labile carbon (LC) plays a crucial role in soil health, agricultural productivity, and climate change mitigation. Nevertheless, most research has focused primarily on the quantification of total organic carbon (TOC), without adeq...

A new species of planthopper in the genus Bothriocera (Hemiptera: Auchenorrhyncha: Cixiidae) from Osa peninsula, Costa Rica on palms (Arecaceae)

Recent survey efforts on palms (Arecaceae) in Costa Rica have resulted in the discovery of many new species of cixiid planthoppers. A recent expedition resulted in the discovery of a new species, Bothriocera aurea sp. nov., from palms on the Osa peninsula. Herein, the novel taxon...

Microbiome Dynamics During Translocation of the Critically Endangered Frog Craugastor ranoides

ABSTRACT Amphibian populations are declining, and species are going extinct due to habitat loss, climate change, and emerging infectious disease, prompting the increasing use of translocations as a conservation tool. Skin‐associated bacterial communities play a key role in amphib...

PREDICTION, SELECTION, AND STIGMA: ETHICAL TENSIONS IN PSYCHIATRIC GENETICS

Overall Abstract Within the past year, the field of psychiatric genetics has continued to advance innovative efforts to understand and improve public health. Several areas raise complex ethical issues, including research on pediatric neurodivergence and neurodiverse populations,...

Frogs have layers: a comparative histological study of colour polymorphism in Oophaga poison frogs

Background Colour polymorphism in aposematic species is often associated with ecological divergence and predator selection. In amphibians, colouration is achieved through the chromatophore unit, a layered structure of pigment-containing cells (xanthophores, melanophores) and stru...

Genetic and behavioural repertoires support olfactory communication in wild capuchin monkeys

Olfaction is a key sense for many mammals, but its role in the social lives of anthropoid primates (monkeys, apes, humans) is poorly understood. Studies of chemosensory receptor genes and olfactory behaviours can provide insight into the evolution and function of olfaction across...

Socioeconomic drivers and historical patterns of disasters at the municipal scale in El Salvador

El Salvador’s geographic location, combined with socioeconomic inequalities and limited disaster risk reduction measures, renders it highly vulnerable to disasters. This study examines historical disaster occurrences at the national and municipal scale, leveraging data from the E...

Professional identity formation and the limits of intelligibility in medical education: a queer reframing

Abstract Professional identity formation (PIF) has become a central tenet of medical education, yet its dominant assumptions leave a constitutive question underexamined: under what conditions can diverse configurations of knowledge, body, affect, and authority be recognized as le...

Learning from model failure: insights from an AI/SHAP-based temporal error decomposition of tracer-aided ecohydrological modelling

Abstract. Process-based models (PBM) have served as testing grounds for hypotheses, being falsified and refined through model evaluation based on temporally complex PBM errors. Yet, conventional evaluation practices (e.g., performance metrics, visual inspection across time series...

Physicochemical characterization, bioactive compounds, and antioxidant activities of tomato hybrids with resistance to Tomato yellow leaf curl virus (TYLCV)

A breeding program at the University of Costa Rica developed three tomato hybrids carrying tolerance to bacterial wilt and resistance genes (Ty) to Tomato yellow leaf curl virus (TYLCV). This study aimed to evaluate the physicochemical properties, carotenoid composition (HPLC-DAD...

Genome assembly and annotation of two clinical Naegleria fowleri isolates from Costa Rica

ABSTRACT Here, we report the genome assembly and annotation of two clinical isolates of Naegleria fowleri from primary amebic meningoencephalitis cases in Costa Rica in 2020 using Illumina sequencing. Each assembly comprised 37 reference-guided scaffolds, with genome sizes of app...