Repositorio Académico de la Universidad Católica del Maule
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Diversification dynamics of a common deep-sea octocoral family linked to the Paleocene-Eocene thermal maximum
No full textThe deep-sea has experienced dramatic changes in physical and chemical variables in the geological past.
However, little is known about how deep-sea species richness responded to such changes over time and space.
Here, we studied the diversification dynamics of one of the most diverse octocorallian families inhabiting deep
sea benthonic environments worldwide and sustaining highly diverse ecosystems, Primnoidae. A newly dated
species-level phylogeny was constructed to infer their ancestral geographic locations and dispersal rates initially.
Then, we tested whether their global and regional (the Southern Ocean) diversification dynamics were mediated by dispersal rate and abiotic factors as changes in ocean geochemistry. Finally, we tested whether primnoids showed changes in speciation and extinction at discrete time points. Our results suggested primnoids likely originated in the southwestern Pacific Ocean during the Lower Cretaceous ~112 Ma, with further dispersal after the physical separation of continental landmasses along the late Mesozoic and Cenozoic. Only the speciation rate of the Southern Ocean primnoids showed a significant correlation to ocean chemistry. Moreover, the PaleoceneEocene thermal maximum marked a significant increase in the diversification of primnoids at global and regional scales. Our results provide new perspectives on the macroevolutionary and biogeographic patterns of an ecologically important benthic organism typically found in deep-sea environments
Eco-epidemiological predator–prey models: a review of models in ordinary differential equations
No full textEco-epidemiology integrates ecological and epidemiological approaches to analyze both the impact of infectious diseases on ecological communities and how interspecific interactions can alter disease dynamics. With the aim of extracting general principles of eco-epidemiological dynamics, this article presents a review of the literature focusing on predator–prey type ordinary differential equation models with disease in one of the species. We included 81 articles that were categorized according to prey growth function, disease transmission function, epidemiological model compartments, and predator functional response. The findings reveal that these models share a common mathematical lineage, which in turn facilitates the construction of models based on the general assumptions identified in this study. The most prevalent models tend to assume logistic prey growth, a bilinear incidence rate for disease transmission, an epidemiological model of the Susceptible–Infected type, and a Holling Type II predator functional response
Targeting human glucocorticoid receptors in fear learning: A multiscale integrated approach to study functional connectivity
No full textFear extinction is a phenomenon that involves a gradual reduction in conditioned fear responses through repeated exposure to fear-inducing cues. Functional brain connectivity assessments, such as functional magnetic resonance imaging (fMRI), provide valuable insights into how brain regions communicate during these processes. Stress, a ubiquitous aspect of life, influences fear learning and extinction by changing the activity of the amygdala, prefrontal cortex, and hippocampus, leading to enhanced fear responses and/or impaired extinction. Glucocorticoid receptors (GRs) are key to the stress response and show a dual function in fear regulation: while they enhance the consolidation of fear memories, they also facilitate extinction. Accordingly, GR dysregulation is associated with anxiety and mood disorders. Recent advancements in cognitive neuroscience underscore the need for a comprehensive understanding that integrates perspectives from the molecular, cellular, and systems levels. In particular, neuropharmacology provides valuable insights into neurotransmitter and receptor systems, aiding the investigation of mechanisms underlying fear regulation and potential therapeutic targets. A notable player in this context is cortisol, a key stress hormone, which significantly influences both fear memory reconsolidation and extinction processes. Gaining a thorough understanding of these intricate interactions has implications in terms of addressing psychiatric disorders related to stress. This review sheds light on the complex interactions between cognitive processes, emotions, and their neural bases. In this endeavor, our aim is to reshape the comprehension of fear, stress, and their implications for emotional well-being, ultimately aiding in the development of therapeutic interventions
Epistemological beliefs and teaching practice: a systematic literature review 2011 to 2021
No full textTeachers’ actions are grounded on their theoretical and disciplinary knowledge; however, their belief system, and in particular their epistemological beliefs, may be influencing their teaching practices. This study analyzes the scientific production between 2011 and 2021 regarding teachers’ epistemological beliefs and their relationship with teaching practice. The methodological design consists of a systematic literature review, following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines in the Web of Science, Scopus, and ERIC databases. The sample considers 18 articles reviewed by thematic content analysis. The results report that this type of belief has a close relationship with teaching approaches, that there are certain inconsistencies with teaching practice, and that links have been established with other areas of study that enrich reflection. It seems prudent and necessary to observe this relationship from a broad, situated, and complex perspective, avoiding generalizing and polarizing the character of these beliefs, by noting that there are various factors involved between what teachers believe about knowledge and what they do in the classroom
Machine learning-based classifiers to predict metastasis in colorectal cancer patients
No full textBackground: The increasing prevalence of colorectal cancer (CRC) in Iran over the past three decades has made it a key public health burden. This study aimed to predict metastasis in CRC patients using machine learning (ML) approaches in terms of demographic and clinical factors.
Methods: This study focuses on 1,127 CRC patients who underwent appropriate treatments at Taleghani Hospital, a tertiary care facility. The patients were divided into training and test datasets in an 80:20 ratio. Various ML methods, including Naive Bayes (NB), random rorest (RF), support vector machine (SVM), neural network (NN), decision tree (DT), and logistic regression (LR), were used for predicting metastasis in CRC patients. Model performance was evaluated using 5-fold cross-validation, reporting sensitivity, specificity, the area under the curve (AUC), and other indexes.
Results: Among the 1,127 patients, 183 (16%) had experienced metastasis. In the predictionof metastasis, both the NN and RF algorithms had the highest AUC, while SVM ranked third in both the original and balanced datasets. The NN and RF algorithms achieved the highest AUC (100%), sensitivity (100% and 100%, respectively), and accuracy (99.2% and 99.3%, respectively) on the balanced dataset, followed by the SVM with an AUC of 98.8%, a sensitivity of 97.5%, and an accuracy of 97%. Moreover, lower false negative rate (FNR), false positive rate (FPR), and higher negative predictive value (NPV) can be confirmed by these two methods. The results also showed that all methods exhibited good performance in the test datasets, and the balanced dataset improved the performance of most ML methods. The most important variables for predicting metastasis were the tumor stage, the number of involved lymph nodes, and the treatment type. In a separate analysis of patients with tumor stages I–III, it was identified that tumor grade, tumor size, and tumor stage are the most important features.
Conclusion: This study indicated that NN and RF were the best among ML-based approaches for predicting metastasis in CRC patients. Both the tumor stage and the number of involved lymph nodes were considered the most important features
Demographics and tenure of the Chilean urban dog population. A mathematical model
No full textBackground
Irresponsible dog ownership in urban areas is a public health concern with significant implications for human, animal, and environmental welfare. Factors such as abandonment, variations in adoption, insufficient supervision, emerging identification initiatives, and collective feeding impact the growth of stray dog populations and the transmission of diseases. Developing a modeling tool to understand the dynamics of canine population growth and the effect of human behavior on this phenomenon is essential.
Methods
An ordinary differential equation model was developed to depict the growth dynamics and movements of urban dog populations, distinguishing between those with owners (restricted and semi-restricted) and those without (stray and community dogs). Two equilibrium states of the system were analyzed: with and without the presence of individually owned dogs. An increase rate for the population of individually owned dogs was calculated, and a local sensitivity analysis was conducted to assess the impact of parameters on the reduction of this population. Additionally, two global sensitivity analysis methods were used to evaluate the simultaneous influence of the parameters.
Results
Findings indicate that system equilibrium depends on various dog categories. Although total eradication of stray and community dogs is unlikely, equilibrium levels are directly related to subpopulation growth rates, responsible ownership practices, and adoption and abandonment rates. The growth rates of the population of dogs without individual owners have a direct and proportional influence on their regulation, while adoption rates have an inverse and proportional effect.
The study, through global sensitivity analysis, identifies key parameters for each dog subpopulation. For restricted dogs, environmental carrying capacity is the most variable factor; for semi-restricted dogs, awareness of responsible ownership is crucial. The abandonment of restricted dogs significantly impacts stray dog dynamics, while the transition from stray to community status is an important variable factor for community dogs.
Conclusion
Addressing the situation of unowned dogs requires a collective effort to reduce risks associated with the spread of zoonotic diseases, environmental pollution, and biodiversity loss, thus contributing to public health and environmental conservation
Design and validation of a questionnaire to assess satisfaction among university students
No full textEvaluar la satisfacción de los estudiantes se ha vuelto relevante para las instituciones de educación superior entendiendo que son los receptores principales del servicio educativo. Su relevancia en educación superior se relaciona a que el cumplimiento de expectativas y buenos índices de satisfacción se ha relacionado a problemáticas como la deserción, rendimiento académico o competitividad de las instituciones. Este trabajo tiene por objetivo diseñar un cuestionario de medición sobre satisfacción estudiantil en universitarios. Se utiliza un enfoque de índices nacionales que incorpora las dimensiones de imagen, expectativas, calidad percibida, valor percibido, satisfacción y compromiso. Una muestra de 927 estudiantes participó el proceso de validación a través de la aplicación del cuestionario construido mediante un sistema de encuestas en línea. Se utiliza las técnicas estadísticas de análisis factorial confirmatorio e invarianza factorial para validar el constructo del instrumento propuesto. Como resultado, se obtiene que el constructo es adecuado para medir la satisfacción estudiantil con adecuados indicadores de validez (χ2/df = 1.463; RMSEA = 0.022 [0.020 – 0.025], SRMR = 0.048; CFI = 0.997; TLI = 0.996; NFI = 0.990). Como conclusión, se indica la utilidad práctica del instrumento construido
considerando su aporte en la gestión y en lo relacionado al monitoreo sistemático de grupos de interés
Psychometric properties of the Heteronormative Attitudes and Beliefs Scale (HABS) in spanish: two studies with chilean university samples
No full textEl objetivo de esta investigación fue comprobar las propiedades psicométricas de la Escala de Actitudes y
Creencias Heteronormativas (HABS) en español, a través de dos estudios con muestras universitarias del
centro-sur de Chile. En el estudio 1, 552 estudiantes universitarios de Temuco respondieron la HABS en línea.
Se realizó un análisis factorial exploratorio y confirmatorio, y un análisis de validez de constructo por grupos
diferenciados por género y orientación sexual. En el estudio 2 participaron 374 estudiantes universitarios de
Talca, Rancagua, Valparaíso y Santiago, y se replicaron los análisis factorial confirmatorio y de validez de
constructo. Ambos estudios evidencian la estructura bidimensional de la HABS en español dividida en ocho
ítems. Los puntajes de heteronormatividad variaron según género y orientación sexual. La HABS-8 muestra
confiabilidad y validez aceptable para medir la heteronormatividad en adultos jóvenes. Se sugieren estudios
para fortalecer esta escala y la investigación sobre heteronormatividad
Gills de novo assembly reveals oxidative stress, unfolded protein, and immune response on red cusk-eel (Genypterus chilensis) under thermal stress
No full textThe heat waves on the South Pacific coast could lead to thermal stress in native fish. The red cusk-eel (Genypterus chilensis) is relevant for Chilean artisanal fisheries and aquaculture diversification. This study examined the effect of high-temperature stress in the gills of G. chilensis in control (14 °C) and high-temperature stress (19 °C) conditions. High-temperature stress induces a significant increase in gills cortisol levels. Additionally, oxidative damage was observed in gills (protein carbonylation and lipoperoxidation). RNA-seq data was used to build the first transcriptome assembly of gills in this species (23,656 annotated transcripts). A total of 1138 down-regulated and 1531 up-regulated transcripts were observed in response to high-temperature stress in gills. The enrichment analysis showed immune response and replication enriched processes (on down-regulated transcripts), and processes related to the folding of proteins, endoplasmic reticulum, and transporter activity (on up-regulated transcripts). The present study showed how gills could be affected by high-temperature stress
Validation of the EORTC QLQ-CR29 questionnaire for the evaluation of health-related quality of life in adults with colorectal cancer in Chile
No full textIntroducción: Personas con cáncer colorrectal (CCR) pueden presentar efectos adversos, perjudicando la calidad de vida relacionada a la salud (CVRS).
Objetivo: Validar el módulo QLQ CR2-9 para evaluación de la CVRS, en Chile.
Materiales y método: Estudio transversal que incluyó 170 personas con CCR. Se analizaron la consistencia interna y validez de constructo del instrumento con test de hipótesis.
Resultados: 117 personas (68,8%) fueron evaluadas antes de la cirugía y 53 (31,2%) después de la cirugía. La consistencia interna del QLQ CR-29 fue α=0,838. Fueron comprobadas las hipótesis planteadas: Los pacientes evaluados antes de la cirugía se quejaron más de “sangre/mucosidad en las heces”, “dolor abdominal”, “pérdida de cabello” e “hinchazón abdominal”, mientras que los pacientes evaluados después presentaron más “incontinencia fecal” (p<0,05). Antes de la cirugía, los pacientes con CCR presentaron mayores valores de “frecuencia urinaria”, “frecuencia de deposiciones”, “dolor en las nalgas”, “problemas con el gusto” y “vergüenza”; mientras que aquellos con cáncer de colon que se quejaban más de “sangre/mucosidad en las heces” (p<0,05). Después de la cirugía, los pacientes con cáncer de recto tenían mayor “frecuencia de deposiciones”, “eliminación de gases” y “vergüenza” (p=0,004) en comparación con los con cáncer de colon (p<0,05). Los pacientes ostomizados presentaron más “incontinencia fecal” y “vergüenza” (p<0,001). Fueron observadas correlaciones positivas y negativas bajas entre la mayoría de las dimensiones del QLQ C-29 con las dimensiones del QLQ C-30.
Conclusión: La versión chilena del módulo QLQ CR-29 es adecuada para evaluar la CVRS en personas con CCR