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Aloe vera peel-derived nanovesicles display anti-inflammatory properties and prevent myofibroblast differentiation
(2024) Ramírez, Orlando; Pomareda, Florencia; Olivares, Belén; Huang, Ya-Lin; Zavala, Gabriela; Carrasco, Javiera; Álvarez, Simón; Leiva, Camila; Hidalgo, Valeria; Romo, Pablo; Sánchez, Matías; Vargas, Ayleen; Martínez, Jessica; Aguayo, Sebastian; Schuh, Christina
Background: Aloe vera (AV) is a medicinal plant, most known for its beneficial effects on a variety of skin conditions. Its known active compounds include carbohydrates and flavonoids such as quercetin and kaempferol, among others. In the past decade, plant nanovesicles (NVs) have gained considerable interest as interkingdom communicators, presenting an opportunity for clinical standardization of natural products. In this study, we aimed to assess the potential of AVpNVs for the treatment of burn wounds.
Methods: AVpNVs were isolated and characterized regarding vesicle yield (nanoparticle tracking analysis) and structure (transmission electron microscopy and atomic force microscopy), as well as their protein content with proteomics. We assessed key characteristics for treating burn wounds in vitro, such as the anti-inflammatory potential in LPS-stimulated macrophages and keratinocytes, and the effect of AVpNVs on myofibroblast differentiation and contraction.
Key findings: AVpNVs presented a homogenous NV population, vesicular shape, and NV-associated protein markers. AVpNVs significantly decreased the secretion of pro-inflammatory cytokines TNFα, IL-1β, and IL-6. Furthermore, AVpNVs inhibited myofibroblast differentiation and significantly decreased their contractile potential in collagen matrices. Observed effects were linked to proteins identified in the isolates through proteomics analysis.
Conclusion: AVpNVs displayed characteristics as an inflammatory modulator, while simultaneously diminishing myofibroblast differentiation and contraction. Novel strategies for burn wound treatment seek to decrease scarring on a cellular and molecular level in the early stages of wound healing, which makes AVpNVs a promising candidate for future plant-vesicle-based treatments.
The parietal cortex has a causal role in ambiguity computations in humans
(2024) Valdebenito-Oyarzo, Gabriela; Martínez-Molina, María Paz; Soto-Icaza, Patricia; Zamorano, Francisco; Figueroa-Vargas, Alejandra; Larraín-Valenzuela, Josefina; Stecher, Ximena; Salinas, César; Bastin, Julien; Valero-Cabré, Antoni; Polania, Rafael
Humans often face the challenge of making decisions between ambiguous options. The level of ambiguity in decision-making has been linked to activity in the parietal cortex, but its exact computational role remains elusive. To test the hypothesis that the parietal cortex plays a causal role in computing ambiguous probabilities, we conducted consecutive fMRI and TMS-EEG studies. We found that participants assigned unknown probabilities to objective probabilities, elevating the uncertainty of their decisions. Parietal cortex activity correlated with the objective degree of ambiguity and with a process that underestimates the uncertainty during decision-making. Conversely, the midcingulate cortex (MCC) encodes prediction errors and increases its connectivity with the parietal cortex during outcome processing. Disruption of the parietal activity increased the uncertainty evaluation of the options, decreasing cingulate cortex oscillations during outcome evaluation and lateral frontal oscillations related to value ambiguous probability. These results provide evidence for a causal role of the parietal cortex in computing uncertainty during ambiguous decisions made by humans.
Oscillatory activity underlying cognitive performance in children and adolescents with autism: a systematic review
(2024) Soto-Icaza, Patricia; Soto-Fernández, Patricio; Kausel, Leonie; Víctor Márquez-Rodríguez, Víctor; Carvajal-Paredes, Patricio; Martínez-Molina, María Paz; Figueroa-Vargas, Alejandra; Billeke, Pablo
Autism spectrum disorder (ASD) is a neurodevelopmental condition that exhibits a widely heterogeneous range of social and cognitive symptoms. This feature has challenged a broad comprehension of this neurodevelopmental disorder and therapeutic efforts to address its difficulties. Current therapeutic strategies have focused primarily on treating behavioral symptoms rather than on brain psychophysiology. During the past years, the emergence of non-invasive brain stimulation techniques (NIBS) has opened alternatives to the design of potential combined treatments focused on the NEurophysiopathology of neuropsychiatric disorders like ASD. Such interventions require identifying the key brain mechanisms underlying the symptomatology and cognitive features.
Evidence has shown alterations in oscillatory features of the neural ensembles associated with cognitive functions in ASD. In this line, we elaborated a
systematic revision of the evidence of alterations in brain oscillations that underlie key cognitive processes that have been shown to be affected in ASD
during childhood and adolescence, namely, social cognition, attention, working memory, inhibitory control, and cognitive flexibility. This knowledge could
contribute to developing therapies based on NIBS to improve these processes in populations with ASD
Theta and alpha oscillations may underlie improved attention and working memory in musically trained children
(2024) Kausel, Leonie; Zamorano, Francisco; Billeke, Pablo; Sutherland, M.E.; Alliende, M. I.; Larrain-Valenzuela, J.; Soto-Icaza, Patricia; Aboitiz, F.
Introduction: Attention and working memory are key cognitive functions that allow us to select and maintain information in our mind for a short time, being essential for our daily life and, in particular, for learning and academic performance. It has been shown that musical training can improve working memory performance, but it is still unclear if and how the neural mechanisms of working memory and particularly attention are implicated in this process. In this work, we aimed to identify the oscillatory signature of bimodal attention and working memory that contributes to improved working memory in musically trained children.
Materials and methods: We recruited children with and without musical training and asked them to complete a bimodal (auditory/visual) attention and working memory task, whereas their brain activity was measured using electroencephalography.
Behavioral, time–frequency, and source reconstruction analyses were made.
Results: Results showed that, overall, musically trained children performed better on the task than children without musical training. When comparing musically trained children with children without musical training, we found modulations in the alpha band pre-stimuli onset and the beginning of stimuli onset in the frontal and parietal regions. These correlated with correct responses to the attended modality. Moreover, during the end phase of stimuli presentation, we found modulations correlating with correct responses independent of attention condition in the theta and alpha bands, in the left frontal and right parietal regions.
Conclusions: These results suggest that musically trained children have improved neu ronal mechanisms for both attention allocation and memory encoding. Our results can be important for developing interventions for people with attention and working memory difficulties.
A multimodal interface for speech perception: the role of the left superior temporal sulcus in social cognition and autism
(2024) Kausel, Leonie; Michon, Maëva; Soto-Icaza, Patricia; Aboitiz, Francisco
Multimodal integration is crucial for human interaction, in particular for social communication, which relies on integrating information from various sensory modalities. Recently a third visual pathway specialized in social perception was proposed, which includes the right superior temporal sulcus (STS) playing a key role in processing socially relevant cues and high-level social perception. Importantly, it has also recently been proposed that the left STS contributes to audiovisual integration of speech processing. In this article, we propose that brain areas along the right STS that support multimodal integration for social perception and cognition can be considered homologs to those in the left, language-dominant hemisphere, sustaining multimodal integration of speech and semantic concepts fundamental for social communication. Emphasizing the significance of the left STS in multimodal integration and associated processes such as multimodal attention to socially relevant stimuli, we underscore its potential relevance in comprehending neurodevelopmental conditions characterized by challenges in social communication such as autism spectrum disorder (ASD). Further research into this left lateral processing stream holds the promise of enhancing our understanding of social communication in both typical development and ASD, which may lead to more effective interventions that could improve the quality of life for individuals with atypical neurodevelopment.
Explorando la autopercepción de competencias mediáticas en profesores de periodismo: Validación de instrumento en universidad chilena
(2024) Sibrian Díaz, Nairbis Desiree; Maureira, Paulina Loreto
La transformación digital plantea un escenario desafiante para la educación en periodismo.
Académicos y estudiantes requieren destrezas para desenvolverse en contextos tecnológicos, así como actitud crítica frente a los medios de comunicación. No obstante, la alfabetización mediática del profesorado universitario de periodismo ha sido poco indagada, aún más su percepción. El objetivo es explorar la autopercepción de competencias mediáticas en docentes de periodismo a través de un instrumento fiable. Por tanto, se presenta el diseño y validación de un cuestionario que explora tales competencias en docentes de una universidad chilena, en las ciudades de Santiago y Concepción. A través del método Delphi, se identifican dimensiones e indicadores y se establece la validez del instrumento con un Alfa de Cronbach de 0.912. El cuestionario tiene 37 ítems y ocho dimensiones: a-) autopercepción inicial, b-) usos de medios y web, c-) tecnología, d-) procesos de interacción, e-) procesos de producción y difusión, f-) lenguaje, g-) ideología y valores, h-) autopercepción final, aplicado a una muestra piloto de
87 docentes. Entre los hallazgos obtenidos destaca que, aunque la mayoría de los docentes se percibe con un alto nivel de competencia mediática (59%), un 60% a veces se informa de manera incidental, un 69% confía en lo que lee en plataformas multimedia y redes sociales y solo un 22% utiliza métodos de verificación para chequear la información en el entorno digital.
Se advierte la necesidad de una competencia mediática más crítica y con un mayor nivel de producción y difusión de contenidos.
La vinculación entre el concepto y la prueba del daño moral. Un análisis jurisprudencial
(2023) Cristián Eduardo Aedo Barrena; Munita Marambio, Renzo Esteban
El análisis del daño moral permite reflexionar en torno a lo que debemos entender conceptualmente por él sea desde una perspectiva subjetiva como objetiva. En el primero de los ámbitos la doctrina en general ha tratado el daño moral bajo la perspectiva de perturbaciones extrapatrimoniales de bienes, cosas o derechos; en circunstancias que, desde el segundo, se refleja un esfuerzo por analizarlo desde el prisma de la afectación a intereses,
postura que defendemos. A su turno, la aproximación conceptual repercute en estándar probatorio de los presupuestos que lo configuran, aspecto que debiera incidir en la cuantificación del agravio. Así, el daño moral subjetivo supone mayor relajo en el estándar, mientras que el daño moral objetivo o anclado en el interés, exige un reforzamiento en el mismo.
Ambos aspectos si bien son susceptibles de distinguirse tanto en el plano contractual como en el extracontractual, se constriñen en el primero básicamente por razones de régimen, el cual exige la identificación de interés protegido dentro del ámbito del contrato
El dies a quo de la prescripción extintiva en el contexto de daños derivados de productos sanitarios defectuosos: una aproximación comparada
(2024) Munita Marambio, Renzo Esteban
La prescripción extintiva de la acción indemnizatoria en el marco de daños ocasionados por productos sanitarios defectuosos se caracteriza por la
complejidad que supone determinar el momento desde que comienza a contabilizarse el plazo. Este problema nos invita a reflexionar en orden a si
el cómputo del término extintivo iniciará a partir del consumo del fármaco o, bien, desde que se manifieste el daño. Para abordarlo proponemos realizar
una exposición comparada de la materia revisando nuestro ordenamiento jurídico, el francés y el español.
Il principio di offensività dei beni giuridici dovrebbe essere riconosciuto esplicitamente dalla costituzione?
(2023) Serra Cruz. Diva; Marcazzolo Awad, Ximena
El comiso sin condena previa en la Ley N°21577 que fortalece la persecución de los delitos de delincuencia organizada y su compatibilidad con el debido proceso
(2023) Serra Cruz, Diva Francesca; Marcazzolo Awad, Ximena
El presente trabajo tiene por objetivo responder la pregunta acerca de si el nuevo procedimiento regulado en el título III bis del Código Procesal Penal, relativo a la imposición del comiso sin condena previa, resulta o no compatible con algunas de las exigencias del debido proceso. Concretamente el estudio se refiere a la presunción de inocencia y el derecho a defensa. Para ello, se realiza una sistematización de la nueva regulación del comiso en el Código Penal, luego de la reforma operada por la Ley 21.577, concluyéndose que el comiso -aun sin condena previa- tiene carácter punitivo, a la luz de una serie de argumentos tanto sustantivos como procesales.
Earthquake-induced landslides coupled to fluvial incision in Andean Patagonia: inferring their effects on landscape at geological time scales
(2022) Morales, Bastian; Lizama, Elizabet; Somos-Valenzuela, Marcelo; Rivera, Diego; Ningshen, Chen
Earthquakes can deeply erode the mountainous landscape through co-seismic landslides, generating large amounts of sediment and debris that are then
transported and distributed by rivers, controlling the landscape evolution.
We can observe this influence in the Liqui˜ne Ofqui Fault System (LOFS), an active intra-arc fault system extending hundreds of kilometers through
the Andes in Chilean Patagonia. For example, on April 21, 2007, a 6.2 Mw earthquake in the Ays´en Fjord triggered over 500 landslides with volumes
reaching 12-20 Mm3. Although there is a well-defined seismic cycle, no study has focused on the effects of co-seismic landslides and sedimentary
dynamics on the evolution of this mountainous landscape. In this research, we seek to improve the long-term understanding of the interaction between
landslides and fluvial incisions in this segment of the Andes. For this reason, we implemented the Landlab-HyLands landscape evolution model (LEM),
a hybrid landscape evolution model that allows modeling landslide activity coupled to fluvial incision. We consider the landslides that occurred during
the 2007 earthquake as a precedent and simulate nine scenarios of ten seismic cycles over 21,000 years based on the 2100-year seismic cycle of the Holocene documented in this region. We further used multiple uplift rates, sediment erodibility, and m/n constant ratios associated with the current power law to assess this parameterization’s impact on the landscape. According to our results, landslides are a fundamental mechanism in the landscape’s evolution in this region. Deposits derived from landslides can create transitory landscape forms that can intervene in fluvial dynamics. According to our simulations, a significant part of the landslide sediment can remain on the slopes for thousands of years. We identified that parameterization considerably impacts the evolutionary response of the landscape in the evaluated time scale. Low m/n ratios can generate a different evolutionary response than other scenarios because the slopes are constantly driven towards their threshold angle, intensifying the interaction between landslides and fluvial incisions. Based on our analysis and considering the historical record of the Aysen Fjord, we can explain a critical primary control of the LOFS on landscape erosion and sediment production because of the surface seismic cycle. In our study, we demonstrate how the implementation of hybrid LEM can help to infer the contribution of sediments associated with large earthquakes and to improve the understanding of the role of landslides in the evolutionary history of Andean Patagonia. However, we stress that it is essential to advance in capturing erodibility and incision parameters of the current power law in the Andes and local geomechanical information. Finally, we believe the LEM can help to deepen the knowledge of these processes in other Andean basins exposed to these geomorphological processes.
¿Siempre tratar desigual a los desiguales?
(2022) Jenkins Peña y Lillo, Gaspar
Las modificaciones introducidas por la Ley 20.720 a la regla del artículo 1496 número 1 del Código Civil y su operatoria en los procedimientos concursales
(2023) Goic, Pedro
Este artículo aborda las significativas modificaciones que la Ley 20.720 ha introducido a la regla de vencimiento anticipado del plazo en el artículo 1496 del Código Civil. Nuestro propósito es desentrañar la estructura delineada por el legislador, tanto en el ámbito civil como en el concursal, explorando cómo esta regla opera en diversos procedimientos concursales. Además, examinamos la reciente modificación de la Ley 21.563, que moderniza los procedimientos concursales según la Ley de Reorganización y Liquidación de Empresas y Personas. Este estudio se guía por un enfoque jurídico normativo, dogmático y jurisprudencial para fundar las posiciones relativas a la necesidad de la insolvencia como presupuesto de los procedimientos concursales y estos, a su vez, como requisitos para el vencimiento anticipado. Al comparar los casos, buscamos respaldar la idea previa mediante la confirmación de nuestra hipótesis de trabajo: la facultad de exigibilidad inmediata se determina por la afectación a un concurso, considerado hoy equivalente a una situación de notoria insolvencia.
Pannexin-1 expression in tumor cells correlates with colon cancer progression and survival
(2024) Fierro, Aaron; Landskron, Glauben; Camhi, Ilan; Basterrechea, Benjamín; Parada, Daniela; Lobos, Lorena; Dubois, Karen; Araneda, Catalina; Romero, Camila; Domínguez, Antonia; Vásquez, Gonzalo; López, Francisco; Alvarez, Karin; González, Carlos; Hager, Carolina; Balboa, Elisa; Eugenin, Eliseo; Hermoso, Marcela; De la Fuente, Marjorie
Aims: Pannexin-1 (PANX1) is a hemichannel that releases ATP upon opening, initiating inflammation, cell proliferation, and migration. However, the role of PANX1 channels in colon cancer remains poorly understood, thus constituting the focus of this study.
Main methods: PANX1 mRNA expression was analyzed using multiple cancer databases. PANX1 protein expression and distribution were evaluated by immunohistochemistry on primary tumor tissue and non-tumor colonic mucosa from colon cancer patients. PANX1 inhibitors (probenecid or 10Panx) were used to assess colon cancer cell lines viability. To study the role of PANX1 in vivo, a subcutaneous xenograft model using HCT116 cells was performed in BALB/c NOD/SCID immunodeficient mice to evaluate tumor growth under PANX1 inhibition using probenecid.
Key findings: PANX1 mRNA was upregulated in colon cancer tissue compared to non-tumor colonic mucosa. Elevated PANX1 mRNA expression in tumors correlated with worse disease-free survival. PANX1 protein abundance was increased on tumor cells compared to epithelial cells in paired samples, in a cancer stage-dependent manner. In vitro and in vivo experiments indicated that blocking PANX1 reduced cell viability and tumor growth.
Significance: PANX1 can be used as a biomarker of colon cancer progression and blocking PANX1 channel opening could be used as a potential therapeutic strategy against this disease.
Levels of dialogicity and narrativity in teacher discourse and its relationship with student learning among high school students in a language class
(2024) Villarroel-Henríquez, Verónica; Bruna, Daniela
This study sought to ascertain the relationship between the varying levels of dialogicity and narrativity found in the discourse of different teachers when teaching, as well as their students’ learning of the same curricular content. A multilevel, correlational quantitative design was used, with the data collection technique of classroom teacher observation, to determine the teachers’ levels of dialogicity and narrativity. Questionnaires were also administered to students to assess their learning and the quality of their recall of the content taught in the classes. The participants were 13 teachers with proven pedagogical excellence in language and communication who taught classes in 13 Chilean schools, as well as their 350 students in their last year of high school education. Using a linear hierarchical model, we concluded that there is a positive, significant relationship between the narrativity of the teacher discourse and student learning. We also found that males learned better with more narrative teachers, while females learned better with more dialogic teachers.
Unveiling the Shadow: Theorizing the Impact of Narcissistic Leadership on Sales Teams
(2024) Bullemore, Jorge
This study investigates the dual nature of narcissistic leadership within sales teams, revealing its potential to both inspire ambitious goals and undermine
team cohesion and performance. By integrating a comprehensive literature review, the research outlines the characteristic behaviors of narcissistic leaders, such as arrogance and a lack of empathy, and their impact on team dynamics, including reduced cohesion, increased conflict, and impaired team performance. The paper proposes strategies to mitigate these negative effects, such as leadership development programs, team-based performance evaluations, and fostering a culture of empathy. It highlights the importance of understanding and addressing the complexities of narcissistic leadership to cultivate healthier, more productive team environments. The findings call for further research into the long-term effects of narcissistic leadership and the development of effective management strategies
Effect of corruption and crime on growth‑oriented informal firms
(2023) Heredia, Walter; Lecuna, Antonio; Heredia, Jorge; Geldes, Cristian; Flores, Alejandro
Traditionally, informal firms have been perceived to be unproductive, lacking skills, and static by necessity, while low institutional quality has been shown to increase their prevalence. However, this research draws on institutional theory to explain the effect of corruption and crime on growth-oriented informal firms that emerge due to opportunities and make decisions voluntarily rather than out of necessity. We construct a logistic regression model using a unique representative dataset of informal firms from the 2019 Zambia Informal Sector Business Survey (ISBS). We find that growth-oriented informal firms pay bribes to remain unregistered (i.e., engage in corruption) and that crime decreases the number of these firms. Our research suggests that policymakers consider the particularities of growth-oriented informal firms when designing policies for entrepreneurs. Growth-oriented informal firms are more likely to consider formalization if they perceive the benefits of formality, and policymakers should be aware that crime could push these firms to subsistence or surveillance, thereby increasing inequality among all firms. Furthermore, researchers should explore the development process of these growth-oriented informal firms, managers in legal firms should consider collaborating with these firms, and the government should support such collaboration.