Institutional Repository Universidad San Sebastián
Not a member yet
9206 research outputs found
Sort by
Propiedades psicométricas de la Escala Factores que influyen en la elección de carreras de Educación Fit-Choice en estudiantes de Pedagogía chilenos
No full textIntroducción. Dada la preocupación global por la atracción de más y mejores candidatos a la carrera pedagógica, es importante contar con instrumentos que nos ayuden a identificar a esos potenciales candidatos. En Chile, existe escasa evidencia de los factores de motivación y percepción que influyen en la elección de estudios en Educación. El objetivo es estudiar las propiedades psicométricas de la escala FIT-Choice, en la población chilena. Esta escala fue desarrollada en Australia por Watt y Richardson, (2007) y traducida al español por Gratacós y López-Jurado, (2016) e identifica factores que influyen en la elección de carreras de Educación. Método. Se adoptó un diseño instrumental transversal. Participaron en el estudio 921 estudiantes de cuatro universidades chilenas (65% mujeres), que cursan quinto año de su formación inicial docente para Educación Inicial (9,1%), Primaria (17,1%) y diversas disciplinas de educación secundaria (73,8%). La estructura factorial del instrumento se evaluó mediante un análisis factorial confirmatorio con un estimador de máxima verosimilitud. Se obtuvieron evidencias de consistencia interna mediante Omega de McDonald (ω), obteniéndose buenos índices de fiabilidad. Resultados. Los resultados muestran que la versión de la escala es válida y fiable para ser empleada en el contexto chileno. Se comprueba la estructura factorial de la escala original, la cual se compone de dos subescalas y 18 factores. Los hallazgos son consistentes con la versión validada en otros países de habla hispana. Discusión y conclusiones. Se puede concluir que esta escala es válida y confiable y que su uso es adecuado para contextos hispanófonos como el chileno. Las características psicométricas evidencian que es posible utilizar este instrumento para sus fines específicos, pero, además, dada su validez intercultural, realizar investigación comparada con otros países en los que este instrumento ha sido validado
A preclinical mice model of multiple sclerosis based on the toxin-induced double-site demyelination of callosal and cerebellar fibers
No full textPublisher Copyright: © The Author(s) 2024.Background: Multiple sclerosis (MS) is an irreversible progressive CNS pathology characterized by the loss of myelin (i.e. demyelination). The lack of myelin is followed by a progressive neurodegeneration triggering symptoms as diverse as fatigue, motor, locomotor and sensory impairments and/or bladder, cardiac and respiratory dysfunction. Even though there are more than fourteen approved treatments for reducing MS progression, there are still no cure for the disease. Thus, MS research is a very active field and therefore we count with different experimental animal models for studying mechanisms of demyelination and myelin repair, however, we still lack a preclinical MS model assembling demyelination mechanisms with relevant clinical-like signs. Results: Here, by inducing the simultaneous demyelination of both callosal and cerebellar white matter fibers by the double-site injection of lysolecithin (LPC), we were able to reproduce CNS demyelination, astrocyte recruitment and increases levels of proinflammatory cytokines levels along with motor, locomotor and urinary impairment, as well as cardiac and respiratory dysfunction, in the same animal model. Single site LPC-injections either in corpus callosum or cerebellum only, fails in to reproduce such a complete range of MS-like signs. Conclusion: We here report that the double-site LPC injections treatment evoke a complex MS-like mice model. We hope that this experimental approach will help to deepen our knowledge about the mechanisms of demyelinated diseases such as MS
Framing fermionic Wilson loops in ABJ(M)
No full textPublisher Copyright: © The Author(s) 2024.Framing plays a central role in the evaluation of Wilson loops in theories with Chern-Simons actions. In pure Chern-Simons theory, it guarantees topological invariance, while in theories with matter like ABJ(M), our theory of interest, it is essential to enforce the cohomological equivalence of different BPS Wilson loops. This is the case for the 1/6 BPS bosonic and the 1/2 BPS fermionic Wilson loops, which have the same expectation value when computed as matrix model averages from localization. This equivalence holds at framing f = 1, which has so far been a challenge to implement in perturbative evaluations. In this paper, we compute the expectation value of the 1/2 BPS fermionic circle of ABJ(M) theory up to two loops in perturbation theory at generic framing. This is achieved by a careful analysis of fermionic Feynman diagrams, isolating their framing dependent contributions and evaluating them in point-splitting regularization using framed contours. Specializing our result to f = 1 we recover exactly the matrix model prediction, thus realizing for the first time a direct perturbative check of localization for this operator. We also generalize our computation to the case of a multiply wound circle, again matching the corresponding matrix model prediction
Calcitriol Treatment Decreases Cell Migration, Viability and β-Catenin Signaling in Oral Dysplasia
No full textPublisher Copyright: © 2024 by the authors.Nearly 90% of oral cancers are characterized as oral squamous cell carcinoma (OSCC), representing the sixth most common type of cancer. OSCC usually evolves from oral potentially malignant disorders that, in some cases, are histologically consistent with a oral dysplasia. The levels of 1α,25 dihydroxyvitamin D3 (1,25-(OH)2D3; calcitriol), the active form of vitamin D3, have been shown to be decreased in patients with oral dysplasia and OSCC. Moreover, treatment with 1,25-(OH)2D3 has been proven beneficial in OSCC by inhibiting the Wnt/β-catenin pathway, a signaling route that promotes cell migration, proliferation, and viability. However, whether this inhibition mechanism occurs in oral dysplasia is unknown. To approach this question, we used dysplastic oral keratinocyte cultures and oral explants (ex vivo model of oral dysplasia) treated with 1,25-(OH)2D3 for 48 h. Following treatment with 1,25-(OH)2D3, both in vitro and ex vivo models of oral dysplasia showed decreased levels of nuclear β-catenin by immunofluorescence (IF) and immunohistochemistry (IHC). Consistently, reduced protein and mRNA levels of the Wnt/β-catenin target gene survivin were observed after treatment with 1,25-(OH)2D3. Moreover, 1,25-(OH)2D3 promoted membranous localization of E-cadherin and nuclear localization of vitamin D receptor (VDR). Functionally, DOK cells treated with 1,25-(OH)2D3 displayed diminished cell migration and viability in vitro
Living with voracious roommates: Factors that explain isotopic niche variation in a mixed colony of insectivorous bats
No full textPublisher Copyright: © 2024 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.Theory predicts that in resource-limited environments, coexisting species may overlap their niche dimensions but must differ in at least one to avoid competitive exclusion. Specifically, it has been suggested that the coexistence of competing species within a guild, could be sustained with mechanisms of resource partitioning, such as segregation along a trophic dimension. Among the most gregarious mammals are bats, which present diversification in their diet based on habitat choice and body size. Despite differences that could explain specialization in prey selection, there are insufficient studies that explore food overlap in mixed bat colonies and the factors that determine the selection of prey, both at intra- and inter-specific levels. To fill this gap, we analyzed the isotope signal (δ13C and δ15N) in feces collected in a mixed colony of Tadarida brasiliensis and Myotis chiloensis. To understand how several factors could influence these isotopic signals, intrinsic explanatory variables were analyzed, including body mass, body length, age, and sex. Also, extrinsic variables were analyzed, including monthly temporality and moonlight intensity. Our findings support age-dependent specialization in M. chiloensis, with a significant role of moonlight intensity and sex on δ15N. In T. brasiliensis, we identified a significant effect of size, sex, and ear length on δ15N. Our analysis indicates that both species of bats experience diverse degrees of overlap through austral summer months, affected by several factors that explain the variability in their fecal isotopic signals
Incidence and risk factors of post-extubation dysphagia in non-neurological critically ill patients
No full textPublisher Copyright: © 2024 Universidad de Castilla la Mancha. All rights reserved.La disfagia post extubación (DPE) es una complicación frecuente en pacientes sometidos a intubación orotraqueal (IOT). Actualmente, existe gran heterogeneidad en los reportes de su incidencia, fluctuando entre un 3 y un 81%. Tampoco existe consenso en relación con sus factores de riesgo. El objetivo del presente estudio fue determinar la incidencia y los factores de riesgo de DPE en pacientes adultos no neurológicos. Se realizó un estudio longitudinal retrospectivo. Se revisaron registros clínicos de pacientes sometidos a IOT en un hospital público de Chile entre junio del 2018 y junio del 2019. Se estimó la incidencia acumulada y se estimaron modelos de regresión logística univariados y multivariados para determinar los factores de riesgo. Se consideró la presencia/ausencia de DPE como variable respuesta, y edad, sexo, días de IOT, tiempo de la evaluación y diagnóstico de ingreso a UPC como variables predictoras. Se recopiló información de 141 pacientes, 72 hombres y 69 mujeres, con una edad promedio de 59 años. De los pacientes, el 73,05% presentó DPE. Tanto la edad como los días de IOT evidenciaron ser factores de riesgo de DPE. El sexo, el tiempo transcurrido hasta la evaluación y la causa de ingreso a la UPC no se asociaron a la presencia de DPE. En el periodo estudiado, se obtuvo una incidencia de un 73,05% de DPE. El principal factor de riesgo para DPE fue el tiempo de IOT, seguido por la edad. El resto de las variables estudiadas no evidenciaron ser factores de riesgo
Targeting the immunoproteasome in hypothalamic neurons as a novel therapeutic strategy for high-fat diet-induced obesity and metabolic dysregulation
No full textPublisher Copyright: © The Author(s) 2024.Objective: Obesity represents a significant global health challenge characterized by chronic low-grade inflammation and metabolic dysregulation. The hypothalamus, a key regulator of energy homeostasis, is particularly susceptible to obesity’s deleterious effects. This study investigated the role of the immunoproteasome, a specialized proteasomal complex implicated in inflammation and cellular homeostasis, during metabolic diseases. Methods: The levels of the immunoproteasome β5i subunit were analyzed by immunostaining, western blotting, and proteasome activity assay in mice fed with either a high-fat diet (HFD) or a regular diet (CHOW). We also characterized the impact of autophagy inhibition on the levels of the immunoproteasome β5i subunit and the activation of the AKT pathway. Finally, through confocal microscopy, we analyzed the contribution of β5i subunit inhibition on mitochondrial function by flow cytometry and mitophagy assay. Results: Using an HFD-fed obese mouse model, we found increased immunoproteasome levels in hypothalamic POMC neurons. Furthermore, we observed that palmitic acid (PA), a major component of saturated fats found in HFD, increased the levels of the β5i subunit of the immunoproteasome in hypothalamic neuronal cells. Notably, the increase in immunoproteasome expression was associated with decreased autophagy, a critical cellular process in maintaining homeostasis and suppressing inflammation. Functionally, PA disrupted the insulin-glucose axis, leading to reduced AKT phosphorylation and increased intracellular glucose levels in response to insulin due to the upregulation of the immunoproteasome. Mechanistically, we identified that the protein PTEN, a key regulator of insulin signaling, was reduced in an immunoproteasome-dependent manner. To further investigate the potential therapeutic implications of these findings, we used ONX-0914, a specific immunoproteasome inhibitor. We demonstrated that this inhibitor prevents PA-induced insulin-glucose axis imbalance. Given the interplay between mitochondrial dysfunction and metabolic disturbances, we explored the impact of ONX-0914 on mitochondrial function. Notably, ONX-0914 preserved mitochondrial membrane potential and attenuated mitochondrial ROS production in the presence of PA. Moreover, we found that ONX-0914 reduced mitophagy in the presence of PA. Conclusions: Our findings strongly support the pathogenic involvement of the immunoproteasome in hypothalamic neurons in the context of HFD-induced obesity and metabolic disturbances. Targeting the immunoproteasome highlights a promising therapeutic strategy to mitigate the detrimental effects of obesity on the insulin-glucose axis and cellular homeostasis. This study provides valuable insights into the mechanisms driving obesity-related metabolic diseases and offers potential avenues for developing novel therapeutic interventions
Estimation of discrete choice models with error in variables : An application to revealed preference data with aggregate service level variables
No full textPublisher Copyright: © 2024 Elsevier LtdThis article proposes a method to estimate disaggregated discrete choice models with errors in the variables. The objective is to estimate the discrete choice models' coefficients to compute the value of time and use it for cost-benefit analysis in transportation planning. The method is general, as it only requires a validation sample to estimate the conditional density of the error-free variables given the mismeasured variables. More specifically, we assume that the attributes of the chosen alternative are reported without error in revealed preference surveys, and we use this information as the validation sample. The mismeasured variables may be spatially aggregate service levels from mobility surveys or transportation network models. Monte Carlo simulations show that the proposed method substantially reduces bias in parameters. We validate the technique with two real data sets from Santiago, Chile
Conflict in the use of treated wastewater in the Maipo-Mapocho basin: : a water scarcity perspective. La conflictividad en el uso de las aguas servidas tratadas en la cuenca del Maipo-Mapocho: una perspectiva desde la escasez hídrica.
No full textHow did European countries set health priorities in response to the COVID-19 threat? A comparative document analysis of 24 pandemic preparedness plans across the EURO region
No full textPublisher Copyright: © 2024The COVID-19 pandemic has forced governments across the world to consider how to prioritise the allocation of scarce resources. There are many tools and frameworks that have been designed to assist with the challenges of priority setting in health care. The purpose of this study was to examine the extent to which formal priority setting was evident in the pandemic plans produced by countries in the World Health Organisation's EURO region, during the first wave of the COVID-19 pandemic. This compliments analysis of similar plans produced in other regions of the world. Twenty four pandemic preparedness plans were obtained that had been published between March and September 2020. For data extraction, we applied a framework for identifying and assessing the elements of good priority setting to each plan, before conducting comparative analysis across the sample. Our findings suggest that while some pre-requisites for effective priority setting were present in many cases – including political commitment and a recognition of the need for allocation decisions – many other hallmarks were less evident, such as explicit ethical criteria, decision making frameworks, and engagement processes. This study provides a unique insight into the role of priority setting in the European response to the onset of the COVID-19 pandemic