EIA University

Abstract Life can be unstable. This is especially true for seedlings growing on erodible surfaces, such as newly exposed areas after glacier retreat. Here we used a space-for-time approach to study the role of biological soil crust (biocrust) as surface stabilizer and facilitator of ecological succession along a glacier forefield chronosequence at the retreating Conejeras glacier in the Tropical Andes. We used the point-intercept method to estimate surface cover of plants, biocrust, bare ground and rocks, as well as surface roughness; and a field soil aggregate kit to estimate soil stability. As hypothesized, following a bare-ground stage near the edge of the glacier, the successional trajectory involved the development of a biocrust belt, including bryophytes and lichens, followed by an increasing vascular plant cover in more advanced successional stages. The development of biocrust was accompanied by higher roughness and stability, which likely increased seed entrapment and seedling establishment. Our results suggest that the development of cyanobacterial-dominated biocrust at the forefield of the Conejeras glacier may favor the establishment of plants with large seeds, such as graminoids from the Festuca genus. Overall, our findings highlight the key role of biocrusts in the ecological dynamics that follow glacier melt in the Tropical Andes.

Penetrating traumatic brain injury (pTBI) is a severe subset of cranial trauma associated with high mortality and a substantial burden of intracranial infections. The pTBI infection rates have decreased from approximately 60% in the pre-war era to about 10% today, due to improvements in operative debridement, critical care, and widespread antibiotic availability; however, the independent effect of prophylactic antibiotics remains uncertain, and clinical practice is highly variable. This systematic review and meta-analysis aims to determine whether prophylactic antibiotics truly reduce intracranial infections in pTBI patients. A systematic review and meta-analysis were conducted following PRISMA guidelines. The PubMed, Scopus, and LILACS were rigorously searched. The primary effectiveness outcome analyzed was the risk of central nervous system infection. Secondary outcomes included antibiotic regimens and duration, mortality, and functional outcomes were assessed. Data were analyzed using a random-effects meta-analysis, and statistical heterogeneity was assessed. The study was registered with PROSPERO (CRD420251033854). Eight studies comprising 1372 patients (891 received antibiotic prophylaxis and 481 did not) were included. We found that the administration of prophylactic antibiotics did not significantly reduce the risk of suffering an intracranial infection OR 1.10 (95% CI 0.29-4.22 I2 = 48.8%). Furthermore, there was no statistically significant difference between monotherapy and multiple antibiotics, or shorter versus longer courses. Moreover, only one study employed a standardized antibiotic regimen. Prophylactic antibiotic administration in patients with penetrating traumatic brain injury was not associated with a statistically significant reduction in the risk of intracranial infections, as evidenced by substantial heterogeneity in the available literature. However, if prophylaxis is administered, it should be a short-course, monotherapy regimen. These findings highlight the urgent need for high-quality, standardized clinical trials to establish evidence-based guidelines for the use of prophylactic antibiotics in this high-risk population.

El factoring en PYMES se ha consolidado como un mecanismo financiero clave, al permitir la cesión de facturas a cambio de liquidez inmediata. Sin embargo, a pesar de su relevancia, persisten vacíos en la literatura que justifican un análisis bibliométrico riguroso. El objetivo de este estudio fue identificar las principales tendencias, referentes y brechas en la investigación sobre factoring en PYMES. Para ello, se aplicó la metodología PRISMA-2020 y se analizaron publicaciones indexadas en Scopus y Web of Science. Los resultados revelaron una evolución temática hacia tópicos como Cash Conversion Efficiency, Supply Chain Finance, Entrepreneurship, Resource Usage y Machine Learning, con referentes destacados como Demirguc-Kunt, A. y Beck, T., y publicaciones líderes en el Journal of Banking and Finance. Asimismo, el análisis de palabras clave evidenció la emergencia de conceptos como Mipymes, Gestión de Riesgos, Blockchain y Factoring Inverso. Se concluye que existen brechas relacionadas con innovación, sostenibilidad ambiental y adopción de tecnologías emergentes, además de la necesidad de explorar diferencias regionales. Estos hallazgos ofrecen una base sólida para orientar futuras investigaciones y aplicaciones prácticas en el financiamiento de PYMES.

From a philosophical and socio-political perspective, mathematics education is traversed by political concern within which aspects such as mathematics, philosophical and social education are linked, in their relative incorporation with the concept of power. The philosophical and the political as an awareness of the existence of power, associated with the concept of mathematics, constitute vital knowledge in today's society, which gives relevance to the improvement of access and quality in the management of knowledge of subjects in mathematics education. This is how scenarios are created where this association is made explicit as soon as mathematical developments are justified as part of their competence as coherent and ethical citizens. This research is anchored to the postulate about the relationship between mathematics, philosophical and sociopolitical education, and identifies that mathematics education tends to the development of citizenship competencies, generating an intricate relationship between education, mathematics, and power, in which a mode that denotes efficiency in the administration of the subject is outlined. In conclusion, the apprehension of mathematics is a political act grounded in philosophy with a social impact that is understood in line with the context in which it is inscribed. This production of knowledge and research as technical processes conceive as a goal to explain how to recognize the performance of the subject in the construction of his or her reality within the framework of philosophy, the social and the political.

Introducción. La ruptura esplénica espontánea es un evento infrecuente y potencialmente mortal, generalmente asociado con patologías subyacentes. Su diagnóstico representa un desafío, ya que suele presentarse con síntomas inespecíficos, lo que retrasa su identificación y el tratamiento oportuno, aspectos fundamentales para reducir la morbimortalidad. Caso clínico. Se reporta el caso de una mujer de 30 años con artritis reumatoide seronegativa, quien consultó con fiebre y artralgia de varios meses de evolución. Durante su hospitalización, presentó un deterioro abrupto con dolor abdominal súbito, taquicardia e hipotensión, sin relación con traumatismos. Resultados. Los estudios imagenológicos mostraron hemoperitoneo severo y laceración esplénica. Tras una evaluación exhaustiva, se descartaron etiologías infecciosas, neoplásicas y hematológicas, diagnosticándose una ruptura esplénica espontánea. Se realizó arteriografía con embolización, logrando la estabilización clínica. Conclusión. Este caso enfatiza la importancia de considerar la ruptura esplénica espontánea dentro del diagnóstico diferencial en pacientes con inestabilidad hemodinámica sin causa aparente. Su reconocimiento temprano y manejo oportuno son determinantes en la evolución clínica y el pronóstico del paciente.

This study investigates the thermal performance of solar chimneys through a combined numerical and experimental approach, aiming to enhance natural ventilation in enclosed spaces. A high-fidelity Computational Fluid Dynamics (CFD) model was developed and rigorously validated against experimental data, demonstrating strong agreement with an average deviation of 3.7%. This validated model served as a robust tool for assessing the impact of key geometric and operational parameters on overall ventilation performance. The study focused on the influence of chimney inclination angle and vertical height, which were systematically varied to determine their effects on mass flow rate and airflow characteristics. The results reveal that both solar radiation intensity and the chimney's inclination angle are critical factors influencing thermally driven ventilation. Specifically, the most favorable airflow rates were recorded when the inclination angle ranged between 60° and 75°, indicating this interval as optimal for maximizing chimney performance. Additionally, increasing chimney height was shown to enhance airflow by enlarging the solar absorbing surface area and amplifying the stack effect, thereby promoting more efficient vertical air displacement. The study emphasizes the importance of achieving an optimal balance between the temperature differential across the chimney and the aerodynamic resistance within the flow domain. This balance is essential for maximizing the mass flow rate without introducing excessive pressure drops that could hinder performance. The findings provide valuable insights for the design and optimization of solar chimney systems aimed at improving energy efficient natural ventilation in buildings