Universidad Libre de Costa Rica

Welcome to the Global Bioethics Bulletin, a recurring series of concise, region-led dispatches on themes of global ethical importance.

The unique mutualism between male euglossine bees and the perfume flowers they pollinate in tropical America is one of the most iconic plant–pollinator associations, with a rich body of research incorporating chemical ecology, speciation, and natural history. Male bees collect species-specific blends of compounds from the environment to subsequently use during courtship display. As bees exhibit rapidly evolving olfactory preferences, divergence in floral scent causing visitation by different sets of bee species is thought to drive speciation of the plants via pollinator isolation. Here, we synthesize our current understanding of this specialized system, reviewing the extensive literature on chemical production and diversity in these plants with implications for speciation, and discuss broader patterns from biogeographic and macroevolutionary studies in the group. We highlight gaps in knowledge and propose promising future avenues of research.

ABSTRACTThe temporal distribution of rainfall is a key driver of flood response. Yet, flood estimation methods are frequently based on symmetrical design profiles. Recent research using sub‐hourly rainfall data from Great Britain indicates that a significant proportion of observed rainfall events are non‐symmetrical. This paper investigates how different rainfall profiles affect river flow hydrographs for a set of small, flash‐flooding catchments. Results show that rainfall profiles affect observed hydrograph peak flow and timing. Most importantly, back‐loaded rainfall profiles lead to higher peak flows than symmetrical or front‐loaded profiles. These observations are compared to current design practice, using the Revitalised Flood Hydrograph (ReFH2.3) model to simulate flows from different rainfall profiles. Simulated events reproduce the observed response of peak magnitude but differ for peak time. A comparison of modelled flows with catchment descriptors indicates that steep, low permeability, wet catchments are most sensitive to rainfall profile shape. These are also the most vulnerable catchments to flash flooding. We recommend that different rainfall profile shapes should be considered for flood risk assessments in rapid response catchments, particularly since global warming is increasing the number of intense, short‐duration downpours.

Acute ischemic stroke (AIS) is the most common neurological complication of infective endocarditis (IE), occurring in 20-40% of patients. In this context, while mechanical thrombectomy (MT) is the standard treatment for patients with AIS due to large-vessel occlusion (LVO), its efficacy and safety in patients with stroke secondary to IE remain unclear. Therefore, amore robust analysis of the efficacy and safety of MT in patients with AIS due to IE was conducted to address the gaps identified in previous studies. An extensive search of PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus databases was conducted from inception to December 2024. The endpoints of interest were: (1)favorable functional outcomes at 90days, (2)successful recanalization, (3)symptomatic intracranial hemorrhage (sICH), (4)any intracranial hemorrhage (aICH), and (5)overall mortality. The pooled proportion rates were employed with arandom effects model with 95% Confidence Intervals (CI) and risk ratios (RR) for binary outcomes with 95% CI. I2 statistics and CochranQ test were performed to verify the heterogeneity. Eight studies published between 2017 and 2024 enrolled 2037 patients (mean age 57.9 years, 62.3% women), of whom 1401 (69%) received mechanical or endovascular thrombectomy for Infective Endocarditis-Related Large Vessel Occlusion (IE-LVO) stroke. Apooled proportion of 29.0% for favorable functional outcomes (mRS 0-2) was reported (95% CI 14.0-43.0%; I2 = 65.7%). Successful recanalization (mTICI2b-3) was observed in 76.0% of patients (95% CI 68.0-84.0%; I2 = 23.6%). sICH was reported in 19.0% (95% CI 0.0-38.0%; I2 = 49.2%) and aICH in 30.0% of the patients (95% CI 23.0-38.0%; I2 = 78.3%). Apooled proportion of 33.0% for all-cause mortality was evidenced (95% CI 21.0-45.0%; I2 = 90.4%). Asignificantly lower incidence of favorable functional outcomes (mRS 0-2) was observed in patients with IE-LVO who underwent MT compared to non-IE-LVO patients (RR 0.48; 95% CI 0.31-0.75; I2 = 0.0%), and no significant difference in the incidence of aICH was found between patients with IE-LVO and those with non-IE-LVO who underwent MT (RR 1.38; 95% CI 0.96-1.98; I2 = 62.4%). High successful recanalization rates were achieved in this population through MT, demonstrating its potential as an effective treatment for IE-LVO. However, the clinical outcomes of patients with IE-LVO were significantly unfavorable compared with those of patients without IE-LVO.

Este estudio analiza cómo, desde la perspectiva del estudiantado, el Aprendizaje Basado en Proyectos (ABP) influye en el compromiso estudiantil y en el aprendizaje en ciencias naturales. Realizado durante el primer semestre de 2021, en una escuela internacional en Costa Rica, se adoptó un enfoque cualitativo con el método de Investigación Acción Participativa (IAP). Mediante observaciones, bitácoras, cuestionarios y entrevistas se recopilaron los datos de 39 estudiantes de 6.º a 8.º grado, se analizaron con codificación cualitativa y categorización temática, y se identificaron patrones relacionados con el compromiso cognitivo, emocional y conductual. Los resultados evidenciaron altos niveles de compromiso, se destaca un 87,5 % de estudiantes que participaron más activamente en discusiones científicas durante los proyectos, y un 85 % que reportó mayor comprensión de conceptos. El estudio concluyó que el ABP es una estrategia efectiva para fomentar un aprendizaje significativo y motivador, al permitirle al estudiantado conectar conceptos científicos con problemas reales. Además, su implementación reforzó habilidades como la autonomía y la colaboración. Sin embargo, se requiere una planificación más estructurada para superar los desafíos relacionados con la gestión del tiempo y la orientación inicial en este enfoque pedagógico.