University of San Carlos of Guatemala

Assessing conservation status and pursuing applicable management priorities for marine megafauna across multiple scales pose significant challenges. Because marine turtles exemplify these challenges, the IUCN Marine Turtle Specialist Group (MTSG) developed the ‘conservation priorities portfolio’ (CPP) framework in 2011 to evaluate population risk and threats for regional management units (RMUs). Here, the MTSG updated the 2011 CPP framework through an inclusive assessment process. Expert elicitation results involving 145 individuals from 50 countries suggested that marine turtle conservation status appears to be improving, but significant challenges remain. Since the previous assessment, long-term abundance trends increased on average, and threat impact scores improved for nearly twice as many RMUs (53%) as worsened (28%) (≥ 10% threshold for changes in numeric scores). While expert-assessed threat impacts have generally decreased, fisheries bycatch remains the highest scored threat across regions and species. Risk-Threat categories improved for most (54%) RMUs. Over 40% of RMUs were scored as Low Risk-Low Threats, eight of which were green turtles Chelonia mydas. Less than 20% of RMUs were scored as High Risk-High Threats, four of which were leatherback turtles Dermochelys coriacea. Most High Risk-High Threats RMUs were in the Pacific Ocean, while most Low Risk-Low Threats RMUs were in the Atlantic Ocean. Eleven RMUs were evaluated as critical data needs. Our results—also provided through an interactive data dashboard—underscore the importance of context-specific planning to effectively target limited conservation resources. Future assessments should further prioritize inclusion of under-represented topics, researchers, and regions to better address multi-faceted conservation challenges.

Decomposition of plant litter is a key ecological process in streams, whose contribution to the global carbon cycle is large relative to their extent on Earth. We examined the mechanisms underlying the temperature sensitivity (TS) of instream decomposition and forecast effects of climate warming on this process. Comparing data from 41 globally distributed sites, we assessed the TS of microbial and total decomposition using litter of nine plant species combined in six mixtures. Microbial decomposition conformed to the metabolic theory of ecology and its TS was consistently higher than that of total decomposition, which was higher than found previously. Litter quality influenced the difference between microbial and total decomposition, with total decomposition of more recalcitrant litter being more sensitive to temperature. Our projections suggest that (i) warming will enhance the microbial contribution to decomposition, increasing CO 2 outgassing and intensifying the warming trend, especially in colder regions; and (ii) riparian species composition will have a major influence on this process.

Background There is an international epidemic of chronic kidney disease of unknown cause (CKDu) in agricultural working populations. Particulate air pollution is a likely contributing factor in populations at risk for CKDu, but there is little personal breathing zone data for these workers. Methods We collected 1 to 3 personal breathing zone particulate matter <5 microns (PM5) gravimetric measurements in 143 male sugarcane harvesters over 2 seasons and concurrent ambient samples using personal sampling pumps and cyclone inlets as a sampling train. Due to very high concentrations observed during a pilot of these methods, personal breathing zone sampling duration was set to 4 h, beginning either at the start of a work shift (AM) or delayed for 4 h (PM). To obtain full-shift exposure concentrations we calculated 8-h time-weighted average (TWA, in µg/m3) estimates of each worker’s full-shift personal breathing zone PM5 exposure concentration by averaging their individual monitored concentration with the median concentration of the unmonitored AM or PM segment from all workers that day to obtain an 8-h TWA. Results Median full-shift personal TWA PM5 concentrations were 449 μg/m3 (range 20.5 to 1,930 μg/m3), which were much higher than ambient concentrations in these fields (median 136, range 22.5 to 2,360 μg/m3). These findings document very high personal breathing zone PM5 exposure in workers at risk for CKDu: median concentrations for all workers were 3.5 (range <1 to 33.6) times as high as concurrent ambient concentrations. Significance These findings suggest that ambient measurements of particulate matter are insufficient to estimate personal exposure in this population and that personal breathing zone monitoring should be used to fully explore air pollution as a risk factor for CKDu. Given that particulate matter from this source likely has multiple hazardous constituents, future research should focus on characterizing all constituents and explore associations with biomarkers of kidney injury.

Adrenal leiomyomas are rare, benign tumors originating in the adrenal glands. They have a varied age of presentation, occur with a slight female predominance, and are typically unilateral, although bilateral cases can occur. Symptoms typically include abdominal or flank pain. This report presents a rare case of an 11-year-old male with disseminated molluscum contagiosum, diagnosed with bilateral adrenal leiomyomas. Imaging revealed large, heterogeneous adrenal masses, and the patient underwent successful adrenalectomy. This case underscores the rarity of adrenal leiomyomas in the pediatric population and highlights the critical role of imaging and surgical intervention in their management.

This short communication synthesizes biodiversity records of urban green spaces in Guatemala City. The research was conducted in the “Cinturón Ecológico Municipal”, or “Municipal Ecological Green Belt”, which consists of ravines covered with natural vegetation within Guatemala City. Available information from digital biodiversity platforms, previous studies and a short biological survey resulted in a checklist of 1688 terrestrial species, classified in 112 families of invertebrates (463 spp.), 77 families of vertebrates (348 spp.), 29 families of fungi (90 spp.), and 132 families of plants (787 spp.). A total of 113 species (7%) have some degree of vulnerability according to international and national lists of threatened species. The ongoing degradation of urban ecosystems demands urgent attention to increase biological surveys to support biodiversity conservation efforts and stricter protection measures as well as restoration of damaged areas.

Varios algoritmos post-cuánticos utilizan multiplicaciones de polinomios en sus definiciones. Se desean métodos más rápidos para multiplicar polinomios al implementar hardware resistente a cuántica. Aunque varios métodos de multiplicación de polinomios pueden reemplazar un método tradicional (convencional), todavía tienen margen para ser optimizados. Un ejemplo de esto es el algoritmo de Karatsuba, que en ocasiones funciona mejor y otras veces funciona igual que el método tradicional. Esto abre la posibilidad de crear un enfoque optimizado. El algoritmo de Striding Karatsuba (una variante de Karatsuba) tiene un comportamiento similar al de Karatsuba, donde hay algunos casos en los que Karatsuba escalonado funciona mejor que el método tradicional, mientras que otras veces, funciona igual. En este trabajo, presentamos un algoritmo híbrido entre Karatsuba y Karatsuba escalonado basado en programación dinámica, que funciona mejor que el método tradicional en todos los casos. El algoritmo propuesto es fácilmente escalable, y se creó una implementación de prueba de concepto en la CPU ARM Cortex-A72. En los resultados experimentales, El método presentado tiene una mejora del 90% y del 20% en términos de conteo de ciclos de CPU y de tasegundos, respectivamente, en comparación con el método tradicional y el método de Karatsuba tradicional.

Echinococcus granulosus sensu lato is the causative agent of cystic echinococcosis (CE), a globally distributed zoonotic infection. In Guatemala, no new data have been reported for the past 80 years on CE. To address this gap, a cross-sectional study at the municipal slaughterhouse of Quetzaltenango was conducted from March to August 2022 to determine the presence of Echinococcus sp. in backyard pigs. Moreover, the species and haplotypes, fertility status of hydatid cysts, association of fertility of the cysts to the sex of the pig and the size of cysts were investigated. For this purpose, 117 pigs were examined post-mortem, and cysts were extracted from their organs. Species identification was performed using nested polymerase chain reaction targeting the cox1 gene, and a haplotype network was constructed. Generalized linear models (GLMs) were applied to assess correlation between cysts fertility, sex of the pig and diameter of the cyst. The study revealed a high prevalence of 38·46% of CE, and a minimum prevalence of Taenia hydatigena of 4·27%. Genetic characterization confirmed the presence of Echinococcus canadensis of the G7 haplogroup. Eight haplotypes unique to Guatemala were identified, along with one of global occurrence. Cysts from male pigs were 3·6 times more likely to be fertile than those from female pigs. A quadratic GLM determined that cysts with a diameter range of 2·09–4·20 cm had a higher probability of being fertile. The high prevalence of CE and the diversity of Guatemalan haplotypes confirm the endemicity of E. canadensis in this region.

Iodine(III) reagents have become a highly relevant tool in organic synthesis due to their great versatility as strong but green oxidants. Several transformations involving cyclizations as well as functionalization of different organic cores have been broadly described and reviewed. Herein, the participation of these reagents in photochemical transformations exclusively by direct irradition or in photoredox cycles using some transition metals, will be briefly described as well as some plausible further transformations that potentially can be developed.

The paper presents the most comprehensive and large-scale global study to date on how higher education students perceived the use of ChatGPT in early 2024. With a sample of 23,218 students from 109 countries and territories, the study reveals that students primarily used ChatGPT for brainstorming, summarizing texts, and finding research articles, with a few using it for professional and creative writing. They found it useful for simplifying complex information and summarizing content, but less reliable for providing information and supporting classroom learning, though some considered its information clearer than that from peers and teachers. Moreover, students agreed on the need for AI regulations at all levels due to concerns about ChatGPT promoting cheating, plagiarism, and social isolation. However, they believed ChatGPT could potentially enhance their access to knowledge and improve their learning experience, study efficiency, and chances of achieving good grades. While ChatGPT was perceived as effective in potentially improving AI literacy, digital communication, and content creation skills, it was less useful for interpersonal communication, decision-making, numeracy, native language proficiency, and the development of critical thinking skills. Students also felt that ChatGPT would boost demand for AI-related skills and facilitate remote work without significantly impacting unemployment. Emotionally, students mostly felt positive using ChatGPT, with curiosity and calmness being the most common emotions. Further examinations reveal variations in students’ perceptions across different socio-demographic and geographic factors, with key factors influencing students’ use of ChatGPT also being identified. Higher education institutions’ managers and teachers may benefit from these findings while formulating the curricula and instructions/regulations for ChatGPT use, as well as when designing the teaching methods and assessment tools. Moreover, policymakers may also consider the findings when formulating strategies for secondary and higher education system development, especially in light of changing labor market needs and related digital skills development.

With the objective of applying remote sensing techniques for crop coefficient estimation and detection of changes in forest cover, in order to generate information that contributes to the sustainable management of agricultural and forestry resources, a study was conducted based on the theoretical foundations of agriculture 4.0, through the implementation of advanced technologies and intelligent data integration to optimize the entire agricultural production cycle. The methodology adopted includes the capture and processing of multispectral images from satellite platforms and unmanned aerial vehicles (UAVs), in order to obtain geometric and spectral information on various crops. Calculations of spectral indices (NDVI, NDMI, NDWI, Kc) and analysis of forest stand losses were performed using advanced software tools in GIS environment and the Google Earth Engine platform. The drone images made it possible to calculate the NDWI to classify soil moisture in high, moderate and low levels. Satellite images facilitated the identification of relationships between crop evaporation coefficient (Kc) and climatic parameters, as well as the detection of areas with forest losses in the Carrizal river basin. The results suggest strategies for the development of precision agriculture activities, promoting the substitution of conventional practices for sustainable development mechanisms based on geospatial technologies. This study contributes to the literature by demonstrating the application of advanced geospatial technologies to optimize agricultural production and sustainability.

Neotropical otters Lontra annectens (Carnivora, Mustelidae) are widely distributed in Central and South America. Studies on the behavior of this species are rare, resulting in the fact that its ethology is one of the lesser known among the mustelids. The Neotropical otter is considered solitary and territorial but not aggressive, and it generally shows a shy and elusive behavior. Here we described the first two documented cases of attack by Neotropical otters on humans. The first occurred in Sacatepéquez, Guatemala, and the second, in La Guajira, Colombia. Respectively, adult female and male humans were injured with differences in the severity of the wounds, clinical course, and outcomes. We recommend further research on the agonistic behavior of Neotropical otters. A protocol for attention to injuries caused by Neotropical otters is suggested.

Guatemala’s Pacific coastal plain, although largely dominated by agricultural land, still contains patches of diverse vegetation that could be vital for supporting bird diversity. Despite the country’s recognition for its rich avian biodiversity, updated data on species richness in this region are still lacking. Understanding the role of different vegetation types in maintaining bird diversity is essential for developing targeted conservation strategies that can both preserve and improve biodiversity in these fragmented landscapes. In this study, we compared species richness and the composition of bird communities across four distinct vegetation types along Guatemala’s Pacific coastal plain and analyzed species turnover and replacement to understand how these habitats contribute to maintaining overall bird diversity at the study site. The avian community consisted predominantly of species adapted to open habitats, with generalist bird species prevailing and only a limited representation of species typical of the understory in subtropical wet forests. Additionally, the observed species turnover value suggests a moderate level of species replacement among different vegetation types at the study site. The moderate nestedness, wherein species-poor communities are subsets of more diverse ones, further implies a decline in overall biodiversity. These findings suggest that the homogenization of the avian community indicates that our study focused on isolated areas that remain in this transformed environment. Our findings argue that protecting and restoring seminatural patches, even modestly sized patches, can be critical for safeguarding biodiversity in human-dominated landscapes and highlight the importance of landscape-level conservation, which enables connectivity between habitat patches to support species with different ecological requirements.

Land use change threatens global biodiversity and compromises ecosystem functions, including pollination and food production. Reduced taxonomic α‐diversity is often reported under land use change, yet the impacts could be different at larger spatial scales (i.e., γ‐diversity), either due to reduced β‐diversity amplifying diversity loss or increased β‐diversity dampening diversity loss. Additionally, studies often focus on taxonomic diversity, while other important biodiversity components, including phylogenetic diversity, can exhibit differential responses. Here, we evaluated how agricultural and urban land use alters the taxonomic and phylogenetic α‐, β‐, and γ‐diversity of an important pollinator taxon—bees. Using a multicontinental dataset of 3117 bee assemblages from 157 studies, we found that taxonomic α‐diversity was reduced by 16%–18% in both agricultural and urban habitats relative to natural habitats. Phylogenetic α‐diversity was decreased by 11%–12% in agricultural and urban habitats. Compared with natural habitats, taxonomic and phylogenetic β‐diversity increased by 11% and 6% in urban habitats, respectively, but exhibited no systematic change in agricultural habitats. We detected a 22% decline in taxonomic γ‐diversity and a 17% decline in phylogenetic γ‐diversity in agricultural habitats, but γ‐diversity of urban habitats was not significantly different from natural habitats. These findings highlight the threat of agricultural expansions to large‐scale bee diversity due to systematic γ‐diversity decline. In addition, while both urbanization and agriculture lead to consistent declines in α‐diversity, their impacts on β‐ or γ‐diversity vary, highlighting the need to study the effects of land use change at multiple scales.

Advancements in modern electronics have enabled the sampling of signals with higher resolution, facilitating the application of new techniques for the determination of pulse arrival times at detectors. In this paper, we introduce a method for accurate and precise pulse arrival time estimation. This method is immune to offset and slow background variations as well as pulse pile-up effects, requiring a single parameter. The validation is performed through simulations and systematic comparisons with traditional methods, using synthetic pulses and experimental data collected from a particle physics detector. The presented results demonstrated superior accuracy and precision of the proposed method compared to widely used constant fraction discrimination and leading-edge discrimination methods. Moreover, this method is suitable for hardware implementation and can be applied to a wide range of pulse types across various experimental contexts, making it a versatile tool for arrival time estimation in diverse applications.

Abies guatemalensis Rehder, an endangered conifer endemic to Central American highlands, is ecologically vital in upper montane forests. It faces threats from habitat fragmentation, unsustainable logging, and illegal Christmas tree harvesting. While previous genetic studies on mature trees from eighteen populations showed high within-population diversity and limited among-population differentiation, the genetic impact of recent anthropogenic pressures on younger generations has yet to be discovered. Understanding these effects is crucial for developing effective conservation strategies for this vulnerable species. We sampled 170 young trees (< 15 years old) from seven populations across Guatemala. Seven microsatellite markers were used to analyse genetic diversity, population structure, and recent demographic history. Moderate levels of genetic diversity were observed within populations (mean Shannon diversity index = 4.97, mean Simpson’s index = 0.51, mean allelic richness = 11.59, mean observed heterozygosity = 0.59). Although genetic structure broadly aligned with mountain corridors, substantial admixture patterns suggest historical connectivity across all populations. Most populations showed evidence of recent bottlenecks (p < 0.05) and inbreeding. The results suggest a potential decline in genetic diversity and increased population structuring (ΦST = 0.274, p < 0.01) over the past decades compared to the previous study on old trees. The observed genetic patterns indicate ongoing impacts of habitat fragmentation and anthropogenic pressures on A. guatemalensis. Conservation efforts should prioritise expanding effective population sizes and facilitating gene flow, particularly for isolated populations. While restoration efforts may be logistically easier within mountain ranges, genetic evidence suggests that increasing overall population connectivity could benefit this species. Management strategies should implement systematic seed collection protocols to maintain genetic diversity in future populations. These findings highlight the urgent need for conservation measures to preserve remaining genetic diversity and promote connectivity among A. guatemalensis populations.

The international collaboration network Food Systems Innovation to Nurture Equity and Resilience Globally (Food SINERGY) unites food system experts concerned with the confluence of environmental, geopolitical, economic, and public health stressors that weaken food systems and increase inequalities. In March 2023, Food SINERGY participants from universities, research institutes, food policy advocacy groups, Indigenous networks, farmers’ associations, consumer organizations, social enterprises, and non-governmental organizations from around the world met in Mont Orford, Québec, for a forum to revisit food system structures across local-to-global scales and to identify key junctures for transformation. This article summarizes the network's discussions in the context of the existing literature. Key knowledge contributions include the importance of diversification throughout the food system for cultivating resilience; the value of food sovereignty in promoting equity across scales; the reconciliation between food sovereignty and equitable trade; the need for consonance between policy environments at different scales to enable positive societal actions; the pioneering role of food system innovations that challenge conventional political and economic structures, with emphasis on agroecology; and the need for critical self-reflection around knowledge production and knowledge use to better serve equitable food systems. These discussion outcomes provide insights for actors seeking to transform food systems in support of equity and resilience.

Background Physical function assessment is key for the management of knee musculoskeletal conditions. There are a wide variety of self-reported outcome measures (SROMs) and performance-based outcome measures (PBOMs) to assess physical function of individuals with knee conditions. However, the content of these measures has not been explored. Objective To explore the range and frequency of physical functions assessed by lower limb PBOMs and SROMs for people with knee osteoarthritis (OA), anterior cruciate ligament (ACL) injuries, and patellofemoral pain (PFP). Methods A scoping review was conducted. We included development or measurement properties studies of knee functional outcome measures for populations with knee OA, ACL injuries, and PFP. We extracted the physical functions assessed in each measure. Each identified physical function was linked to a code from the International Classification of Functioning, Disability and Health (ICF) framework. Results 4146 articles were screened. A total of 143 articles were included. The median number of physical functions assessed was nine for SROMs and one for PBOMs. The three most assessed physical functions were climbing stairs, walking short distances, and standing up from sitting. Climbing stairs was the most assessed physical function in measures for knee OA and PFP populations, whereas jumping was in measures for the ACL-injured population. Conclusion SROMs assess a broader range of physical functions, whereas PBOMs focus on discrete activities. ACL and PFP measures evaluated more challenging physical functions than knee OA measures. Current physical function outcome measures are not well suited to assess performance in knee OA populations with mild or diverse levels of impairment.

Tropical hydroclimate in monsoonal regions has been largely understood according to the orbital monsoon hypothesis, in which rainfall exhibits strong covariation with local summer insolation on precessional (~21,000 years) time scales, as exemplified in the Asian and South American monsoon stalagmite records. However, paleo-rainfall variations in some tropical regions are poorly explained by the orbital hypothesis, suggesting alternative forcing mechanisms of regional monsoon changes. Here, we show a 140,000-year record of Central American rainfall from oxygen-isotope (δ¹⁸O) time series of precisely dated stalagmites which reveals two dominant thermally-controlled monsoon regimes in which the Atlantic Ocean thermal state linked to the meridional overturning circulation (AMOC) is the primary driver, and local orbital summer insolation control is limited. Our reconstruction, supported by isotope-enabled climate model simulations, pinpoints the potential impacts of future AMOC weakening on the Central American and Caribbean climate.

Infantile hemangiomas are the most common type of vascular tumors, affecting ~5% of infants within the first weeks of life. In rare instances, these tumors can lead to Kasabach–Merritt phenomenon (KMP), a life-threatening consumptive coagulopathy characterized by thrombocytopenia, microangiopathic hemolytic anemia, and hypofibrinogenemia. In the present case, a 20-month-old patient is diagnosed with KMP. This case report highlights the challenges in diagnosis and management, reinforcing the importance of multidisciplinary approach.