Distributional extensions of Carollia castanea and Micronycteris minuta from Guatemala, Central America

Field expeditions in 2011 that inventoried the terrestrial vertebrate fauna of two wildlife protected areas in the tropical Caribbean of Guatemala have produced the first confirmed records of two bats for the country: the white-bellied big-eared bat, Micronycteris (Schizonycteris) minuta (Gervais 1856) and the Chesnut short-tailed bat Carollia castanea H. Allen, 1890, both of neotropical distribution and with their current northern limit at Lancetilla, Honduras. The record of M. minuta at Sierra de Caral, Guatemala extends the range of this species 137 km to the west, and the record of C. castanea at Cerro San Gil extends its range 147 km to the west

Desarrollo de un modelo predictivo para motores de encendido provocado operando con gasolina, con el fin de predecir potencia de salida, torque y consumo específico

El trabajo desarrollado en la presente tesis de maestría, está encaminado a la formulación de un modelo predictivo de motores de combustión interna de encendido provocado, alimentados con gasolina con inyección indirecta en estado estacionario. Para ello, se posee el desarrollo previo de modelos de diagnóstico de la combustión y predicción de presión en cámara de combustión de diversos autores y distintos tipos de motores. Con base en ese desarrollo, previo a las consideraciones de deformaciones en cámara, fueron añadidos modelos de deformación que consideran efectos térmicos sobre el pistón y la biela, además de desplazamientos de las uniones entre los componentes del mecanismo manivela-biela-pistón, así como la consideración del fenómeno de transferencia de calor a través de las paredes. A su vez, en el modelo se empleó una formulación de dos zonas al interior de la cámara de combustión y también cuenta con la capacidad de predecir ensayos de combustión intermedios a los ya predichos. Durante el desarrollo de este trabajo se obtuvo que, con un determinado número de datos, puede hacerse una caracterización global de motores de combustión interna, con el fin de predecir estadísticamente parámetros operacionales parametrizables, tales como la relación de compresión real, y constantes asociadas a los sub-modelos de deformaciones y transferencia de calor. El modelo presenta un alto nivel de desempeño a la hora de predecir tanto variables termodinámicas al interior de la cámara de combustión, como de parámetros operacionales indicados a la hora de evaluar el desempeño de un motor.MaestríaMagister en Ingeniería Mecánic

First-generation college students’ motives to start university education:An investment in self- development, one’s economic prospects or to become a role model?

In this article, we engage with the emerging literature that studies the increased enrolment of first-generation college students (FGCS), that is, students from households where neither parent has obtained a bachelor’s /master’s degree. Our article answers two research questions. First, data from 2,338 first-year students are used to investigate the extent to which FGCS differ from continuing-generation college students (CGCS) concerning the reason why one enrols in university education. Second, to what degree do these motives explain differences in study choice? Our results show that FCGS, compared to CGCS, more strongly endorsed the economic investment motive and what we call the social investment motive, that is, the motivation to become a role model for one’s community. In addition, our findings reveal that the choice for more economically rewarding fields of study is related to these motives to start a university education. In the conclusion, we discuss the implications of our findings

Metabolic modelling in a dynamic evolutionary framework predicts adaptive diversification of bacteria in a long-term evolution experiment

Background: Predicting adaptive trajectories is a major goal of evolutionary biology and useful for practical applications. Systems biology has enabled the development of genome-scale metabolic models. However, analysing these models via flux balance analysis (FBA) cannot predict many evolutionary outcomes including adaptive diversification, whereby an ancestral lineage diverges to fill multiple niches. Here we combine in silico evolution with FBA and apply this modelling framework, evoFBA, to a long-term evolution experiment with Escherichia coli. Results: Simulations predicted the adaptive diversification that occurred in one experimental population and generated hypotheses about the mechanisms that promoted coexistence of the diverged lineages. We experimentally tested and, on balance, verified these mechanisms, showing that diversification involved niche construction and character displacement through differential nutrient uptake and altered metabolic regulation. Conclusion: The evoFBA framework represents a promising new way to model biochemical evolution, one that can generate testable predictions about evolutionary and ecosystem-level outcomes

Temporal and spatial instability in neutral and adaptive (MHC) genetic variation in marginal salmon populations

The role of marginal populations for the long-term maintenance of species’ genetic diversity and evolutionary potential is particularly timely in view of the range shifts caused by climate change. The Centre-Periphery hypothesis predicts that marginal populations should bear reduced genetic diversity and have low evolutionary potential. We analysed temporal stability at neutral microsatellite and adaptive MHC genetic variation over five decades in four marginal Atlantic salmon populations located at the southern limit of the species’ distribution with a complicated demographic history, which includes stocking with foreign and native salmon for at least 2 decades. We found a temporal increase in neutral genetic variation, as well as temporal instability in population structuring, highlighting the importance of temporal analyses in studies that examine the genetic diversity of peripheral populations at the margins of the species’ range, particularly in face of climate change

Oncocytic carcinoma of the parotid gland with late cervical lymph node metastases: a case report

<p>Abstract</p> <p>Introduction</p> <p>Oncocytic carcinoma is a rare proliferation of cytomorphologically malignant oncocytes mainly found in glandular tissue, accounting for 0.5% of all epithelial salivary gland malignancies and 0.18% of all epithelial salivary gland tumors.</p> <p>Case presentation</p> <p>We report a case of oncocytic carcinoma arising in the parotid gland of a 65-year-old Caucasian man. Our patient initially underwent left superficial parotidectomy, including the removal of the mass. A close follow-up was made, and four years after first surgery cervical lymph node metastases were confirmed. Therefore, a complete parotidectomy and radical neck dissections were performed. There were no complications and no sign of recurrence after six months of follow-up.</p> <p>Conclusion</p> <p>Oncocytic carcinoma is an extremely rare malignancy in the salivary glands. Prophylactic neck dissection may be indicated for tumors larger than 2 cm in diameter (our patient's tumor was 2.5 cm at its greatest diameter). The clinical course of our patient, with the appearance of cervical lymph node metastases after four years of follow-up, supports this approach. Further investigation of the prognosis and correct treatment of patients with oncocytic carcinoma are required as more cases are reported.</p

Manipulation of the unfolded protein response: A pharmacological strategy against coronavirus infection.

Coronavirus infection induces the unfolded protein response (UPR), a cellular signalling pathway composed of three branches, triggered by unfolded proteins in the endoplasmic reticulum (ER) due to high ER load. We have used RNA sequencing and ribosome profiling to investigate holistically the transcriptional and translational response to cellular infection by murine hepatitis virus (MHV), often used as a model for the Betacoronavirus genus to which the recently emerged SARS-CoV-2 also belongs. We found the UPR to be amongst the most significantly up-regulated pathways in response to MHV infection. To confirm and extend these observations, we show experimentally the induction of all three branches of the UPR in both MHV- and SARS-CoV-2-infected cells. Over-expression of the SARS-CoV-2 ORF8 or S proteins alone is itself sufficient to induce the UPR. Remarkably, pharmacological inhibition of the UPR greatly reduced the replication of both MHV and SARS-CoV-2, revealing the importance of this pathway for successful coronavirus replication. This was particularly striking when both IRE1α and ATF6 branches of the UPR were inhibited, reducing SARS-CoV-2 virion release (~1,000-fold). Together, these data highlight the UPR as a promising antiviral target to combat coronavirus infection

Intoxicaciones exógenas agudas, aspectos clínicos y epidemiológicos

A retrospective descriptive study was conducted with the aim of describing the clinical and epidemiological aspects in children and adolescents who were admitted with a diagnosis of acute exogenous poisoning to the José Luis Miranda Provincial Pediatric University Hospital in Santa Clara during 2006. The universe was made up of 400 patients. The sample was formed by 115 patients from Villa Clara province who were admitted with the diagnosis of accidental poisoning, iatrogenic poisoning or suicide. Variables such as age, sex, etiologic agent, cause of intoxication, and patient’s outcome were studied. These data were collected on a form, and were processed in the version 11 of the SPSS. Drug poisonings predominated, followed by suicide attempts. The evolution was satisfactory for most patients and minimal the consequences. There was no report of death in this study.Se realizó un estudio descriptivo retrospectivo con el objetivo de describir los aspectos clínicos y epidemiológicos en los niños y adolescentes con diagnóstico de intoxicaciones exógenas agudas que ingresaron en el Hospital Pediátrico Provincial Universitario “José Luis Miranda” de Santa Clara en el año 2006. El universo lo conformaron 400 pacientes, la muestra estuvo representada por 115 enfermos que ingresaron con el diagnóstico de intoxicación accidental, iatrogénica o suicida pertenecientes a la Provincia de Villa Clara. Se estudiaron variables como la edad, el sexo, el agente etiológico, la causa de la intoxicación y la evolución del paciente; todos estos datos se recogieron en un formulario y se procesaron en la  versión 11 del SPSS. Predominaron las intoxicaciones por medicamentos seguidas por los intentos suicidas, la evolución fue satisfactoria para la mayoría de los pacientes y las secuelas mínimas; no se informó ningún fallecido en este estudio