Is social decision making for close others consistent across domains and within individuals?

Humans make decisions across a variety of social contexts. Though social decision-making research has blossomed in recent decades, surprisingly little is known about whether social decision-making preferences are consistent across different domains. We conducted an exploratory study in which participants made choices about 2 types of close others: parents and friends. To elicit decision making preferences, we pit the interests in parents and friends against one another. To assess the consistency of preferences for close others, decision making was assessed in three domains-risk taking, probabilistic learning, and self-other similarity judgments. We reasoned that if social decision-making preferences are consistent across domains, participants ought to exhibit the same preference in all three domains (i.e., a parent preference, based on prior work), and individual differences in preference magnitude ought to be conserved across domains within individuals. A combination of computational modeling, random coefficient regression, and traditional statistical tests revealed a robust parent-over-friend preference in the risk taking and probabilistic learning domains but not the self-other similarity domain. Preferences for parent-over-friend in the risk-taking domain were strongly associated with similar preferences in the probabilistic learning domain but not the self-other similarity domain. These results suggest that distinct and dissociable value-based and social-cognitive computations underlie social decision making. (PsycInfo Database Record (c) 2020 APA, all rights reserved)

Greater response variability in adolescents is associated with increased white matter development.

Adolescence is a period of learning, exploration, and continuous adaptation to fluctuating environments. Response variability during adolescence is an important, understudied, and developmentally appropriate behavior. The purpose of this study was to identify the association between performance on a dynamic risky decision making task and white matter microstructure in a sample of 48 adolescents (14-16 years). Individuals with the greatest response variability on the task obtained the widest range of experience with potential outcomes to risky choice. When compared with their more behaviorally consistent peers, adolescents with greater response variability rated real-world examples of risk taking behaviors as less risky via self-report. Tract-Based Spatial Statistics (TBSS) were used to examine fractional anisotropy (FA) and mean diffusivity (MD). Greater FA in long-range, late-maturing tracts was associated with higher response variability. Greater FA and lower MD were associated with lower riskiness ratings of real-world risky behaviors. Results suggest that response variability and lower perceived risk attitudes of real-world risk are supported by neural maturation in adolescents

Efecto de la microcina J25 en la cadena respiratoria de Escherichia coli

En la actualidad existe una marcada tendencia a la demanda de alimentos naturales con pocos procesamientos. Además, el uso indiscriminado de antibióticos de amplio espectro ha provocado el aumento de bacterias patógenas multiresistentes a los antibióticos existentes. Las bacteriocinas son consideradas como una posible solución ante esta problemática. En particular, la microcina J25 (MccJ25) es una bacteriocina muy estable activa frente a patógenos transmitidos por alimentos, entre ellos Escherichia coli, Salmonella y Shigella. Posee dos mecanismos de acción, inhibe la transcripción mediante la unión a la ARN polimerasa e inhibe la cadena respiratoria residente en la membrana plasmática.El objetivo de esta tesis fue profundizar el conocimiento del efecto de la MccJ25 sobre la cadena respiratoria de E. coli. A partir de resultados previos, se planteó la hipótesis de que el péptido actúa sobre los citocromos. En la cadena respiratoria de E. coli existen dos tipos de ubiquinol oxidasas, el citocromo bo3 y los citocromos bd (bdI y bdII). Se demostró, in vivo, que estos son fundamentales para la acción inhibitoria de la microcina, siendo las oxidasas más importante los citocromos bo3 y bdI. Empleando cepas de E. coli que tienen aumentada la entrada de la MccJ25 mediante el aumento de expresión de la proteína transportadora FhuA, se observó que las mutantes en los citocromos bo3 y bdI mostraron una marcada disminución de la sensibilidad frente al péptido con respecto a la cepa parental. Además, en ensayos llevados a cabo in vitro el péptido fue capaz de inhibir la actividad ubiquinol oxidasa y de inducir un aumento en la producción de especies reactivas del oxígeno cuando se utilizó el citocromo bdI purificado a partir de la membrana de E. coli. Esta inhibición es dosis dependiente y según las constantes cinéticas (Km y Vmax) sería de tipo no competitiva. Sin embargo, no se observó este mismo efecto cuando el ensayo fue realizado en presencia del citocromo bo3. Por otro lado, el análisis de la diferencia entre los espectros de la forma reducida y oxidada de los citocromos manifestó una reducción directa del citocromo bdI por parte de la MccJ25. Estos resultados indicarían que la MccJ25 podría inhibir de manera directa solo al citocromo bdI. Actualmente, el citocromo bdI es un potencial blanco de acción para antibióticos alternativos ya que solo se encuentra en células procariotas, entre ellas patógenos tales como E. coli, Mycobacterium tuberculosis y Klebsiella pneumonia. Dada la existencia de una relación estructural entre el citocromo bo3 y el complejo IV de la mitocondria se proyectan estudios más profundos para dilucidar el mecanismo de inhibición de la MccJ25 sobre los citocromos. Esto permitiría el desarrollo de estrategias para dirigir específicamente la actividad del péptido al citocromo bdI. De esta manera sería posible diseñar péptidos modificados más eficaces sobre este blanco de acción. La MccJ25 por su naturaleza y porsu capacidad de actuar sobre dos dianas diferentes, una a nivel intracelular y otra a nivel de la cadena respiratoria, es una alternativa prometedora para ser considerada como un nuevo antimicrobiano.At present there is a pronounced tendency to demand for minimally processed natural foods. Furthermore, misuse of broad-spectrum antibiotics has led to an increase in resistant pathogenic bacteria. Bacteriocins could be considered as a possible solution to this issue. Microcin J25 (MccJ25) is a very stable bacteriocin active against foodborne pathogens, including Escherichia coli, Salmonella and Shigella. This peptide has two targets, one of them is the RNA polymerase through the binding to its secondary channel and the other is the respiration that involves the inhibition of enzymes of respiratory chain. The aim of this thesis was to deepen the knowledge of the effect of MccJ25 on E. coli respiratory chain. From previous results, we hypothesized that the peptide acts on cytochromes. E. coli respiratory chain has two types of ubiquinol terminal oxidases, cytochrome bo3 and cytochromes bd (bdI and bdII). In this work, we demonstrated that these are essential for the peptide inhibitory effect, where cytochromes bo3 and bdI play a fundamental role. The entry of MccJ25 to the target cell was increased by over-expressing the transporter protein FhuA. The cytochromes bo3 and bdI mutants showed a marked decrease sensitivity to the peptide regarding the parental. Additionally, in vitro assays performed using purified cytochrome bdI from E. coli membrane, revealed that the peptide was able to inhibit its ubiquinol oxidase activity and induced an increase in the reactive oxygen species production. This inhibition is dose dependent and it would be a noncompetitive type inhibition according to its kinetic constants (Km and Vmax). However, this effect was not observed when assay was performed with cytochrome bo3. Furthermore, the analyses of reduced minus air-oxidized difference spectra of the purified cytochromes manifested a direct reduction of cytochrome bdI by MccJ25. These findings indicate that MccJ25 could just inhibit cytochrome bdI in a direct way. Cytochrome bdI is found only in prokaryotes, including pathogens such as E. coli, Mycobacterium tuberculosis and Klebsiella pneumonia. Currently, this cytochrome is a potential target for alternative antibiotic. There is a structural relationship between cytochrome bo3 and mitochondrial complex IV. It exist a growing need for deeper studies to elucidate MccJ25 mechanism of cytochromes inhibition. These would allow a development of strategies to specifically lead the peptide activity to the cytochrome bdI. Thereby it would be possible to design modified peptides that are more effective on this target. By its nature and its ability to act on two different cellular targets, one inside the cell and the other at the respiratory chain, MccJ25 is a promising alternative to be considered as a new potential antimicrobialsFil: Galván, Adriana Emilce. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentin

Diseño administrativo para la optimización del sistema de cobranza de Cediul S.A.

The objective of the research was the proposed administrative design optimization collection system CEDIUL S.A. The work represents a study in the form of feasible project, supported by field research descriptive. In the proposed diagnostic support, identified the weaknesses and failures in the development of business activities, specifically in the area of Accounts Receivable and therefore in the area and Collections, so that observations could be made or fundamental assumptions based on one of the phases of the administrative process as is the control, giving as recommendations, implement policies, standards and procedures proposed and promote the appropriate use of different financial indicators, to ensure adequate liquidity and efficient management improving business transactions existing problems.El objetivo de la investigación fue la propuesta de un diseño administrativo para la optimización del sistema de cobranza de CEDIUL S.A. El trabajo, representa un estudio bajo la modalidad de proyecto factible, apoyado en una investigación de campo de carácter descriptivo. En el diagnóstico que sustento la propuesta, se determinaron las debilidades y fallas en el desarrollo de las actividades de la empresa, específicamente en el área de Cuentas por Cobrar y por consiguiente en el área de y Cobranzas, por lo que se pudo realizar las observaciones o premisas fundamentales basadas en una de las fases del proceso administrativo como lo es el control, dando como recomendaciones, aplicar las políticas, normas y procedimientos propuestos y promover el uso adecuado de los diferentes indicadores financieros, para asegurar una adecuada liquidez y una gestión eficiente de las transacciones empresariales mejorando la problemática existente

New insights into enterocin CRL35: mechanism of action and immunity revealed by heterologous expression in Escherichia coli

The role of the class IIa bacteriocin membrane receptor protein remains unclear, and the following two different mechanisms have been proposed: the bacteriocin could interact with the receptor changing it to an open conformation or the receptor might act as an anchor allowing subsequent bacteriocin insertion and membrane disruption. Bacteriocin-producing cells synthesize an immunity protein that forms an inactive bacteriocin–receptor–immunity complex. To better understand the molecular mechanism of enterocin CRL35, the peptide was expressed as the suicidal probe EtpM-enterocin CRL35 in Escherichia coli, a naturally insensitive microorganism since it does not express the receptor. When the bacteriocin is anchored to the periplasmic face of the plasma membrane through the bitopic membrane protein, EtpM, E. coli cells depolarize and die. Moreover, co-expression of the immunity protein prevents the deleterious effect of EtpM-enterocin CRL35. The binding and anchoring of the bacteriocin to the membrane has demonstrated to be a sufficient condition for its membrane insertion. The final step of membrane disruption by EtpM-enterocin CRL35 is independent from the receptor, which means that the mannose PTS might not be involved in the pore structure. In addition, the immunity protein can protect even in the absence of the receptor.Fil: Barraza, Daniela Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Ríos Colombo, Natalia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Galván, Adriana Emilce. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Acuña, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Minahk, Carlos Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Bellomio, Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Chalon, Miriam Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentin

Ventral striatum activation to prosocial rewards predicts longitudinal declines in adolescent risk taking

AbstractAdolescence is a period of intensified emotions and an increase in motivated behaviors and passions. Evidence from developmental neuroscience suggests that this heightened emotionality occurs, in part, due to a peak in functional reactivity to rewarding stimuli, which renders adolescents more oriented toward reward-seeking behaviors. Most prior work has focused on how reward sensitivity may create vulnerabilities, leading to increases in risk taking. Here, we test whether heightened reward sensitivity may potentially be an asset for adolescents when engaged in prosocial activities. Thirty-two adolescents were followed over a one-year period to examine whether ventral striatum activation to prosocial rewards predicts decreases in risk taking over a year. Results show that heightened ventral striatum activation to prosocial stimuli relates to longitudinal declines in risk taking. Therefore, the very same neural region that has conferred vulnerability for adolescent risk taking may also be protective against risk taking

Implementación de Reliability Centred Maintenance para reducir los fallos en la catenaria rígida de la empresa Sifel Rail – Lima, 2021

La presente investigación tiene como objetivo implementar la metodología del Reliability Centred Maintenance (RCM) en el sistema de la cantería rígida de la empresa Sifel Rail con el fin de poder tener una reducción de fallos, costos y tiempos de reparación. La investigación tiene siete capítulos. En el primer capítulo, se desarrolla la situación actual de la empresa Sifel Rail y la problemática de los fallos que se presentan en la catenaria rígida, también se definen los objetivos y las hipótesis. El segundo capítulo abarca el marco teórico donde se encuentran los antecedentes de anteriores investigaciones donde se haya aplicado exitosamente el RCM. En el tercer capítulo refiere a la metodología de la investigación y la implementación del Reliability Centred Maintenance que cuenta con cinco fases. En el cuarto capítulo se explica los principales resultados que se encontraron en la investigación para ello se da uso al SPSS. En el quinto capítulo se enfoca en la discusión la cual se compara los resultados de la investigación con investigaciones de otros autores. En el sexto y séptimo capítulo se presentan las conclusiones y recomendaciones que se obtuvo de la presente investigación

Flocculation of Cellulose Microfiber and Nanofiber Induced by Chitosan–Xylan Complexes

This study aims to provide a comprehensive understanding of the key factors influencing the rheological behavior and the mechanisms of natural polyelectrolyte complexes (PECs) as flocculation agents for cellulose microfibers (CMFs) and nanofibers (CNFs). PECs were formed by combining two polyelectrolytes: xylan (Xyl) and chitosan (Ch), at different Xyl/Ch mass ratios: 60/40, 70/30, and 80/20. First, Xyl, Ch, and PEC solutions were characterized by measuring viscosity, critical concentration (c*), rheological parameter, ζ-potential, and hydrodynamic size. Then, the flocculation mechanisms of CMF and CNF suspensions with PECs under dynamic conditions were studied by measuring viscosity, while the flocculation under static conditions was examined through gel point measurements, floc average size determination, and ζ-potential analysis. The findings reveal that PEC solutions formed with a lower xylan mass ratio showed higher intrinsic viscosity, higher hydrodynamic size, higher z-potential, and a lower c*. This is due to the high molecular weight, charge, and gel-forming ability. All the analyzed solutions behave as a typical non-Newtonian shear-thinning fluid. The flocculation mechanisms under dynamic conditions showed that a very low dosage of PEC (between 2 and 6 mg PEC/g of fiber) was sufficient to produce flocculation. Under dynamic conditions, an increase in viscosity indicates flocculation at this low PEC dosage. Finally, under static conditions, maximum floc sizes were observed at the same PEC dosage where minimum gel points were reached. Higher PEC doses were required for CNF suspensions than for CMF suspensions.Fil: Bastida, Gabriela Adriana. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología Celulósica; ArgentinaFil: Tarrés, Quim. Universidad de Girona; EspañaFil: Aguado, Roberto. Universidad de Girona; EspañaFil: Delgado Aguilar, Marc. Universidad de Girona; EspañaFil: Zanuttini, Miguel Angel Mario. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología Celulósica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Galván, María Verónica. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología Celulósica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

At risk of being risky: The relationship between "brain age" under emotional states and risk preference.

Developmental differences regarding decision making are often reported in the absence of emotional stimuli and without context, failing to explain why some individuals are more likely to have a greater inclination toward risk. The current study (N=212; 10-25y) examined the influence of emotional context on underlying functional brain connectivity over development and its impact on risk preference. Using functional imaging data in a neutral brain-state we first identify the "brain age" of a given individual then validate it with an independent measure of cortical thickness. We then show, on average, that "brain age" across the group during the teen years has the propensity to look younger in emotional contexts. Further, we show this phenotype (i.e. a younger brain age in emotional contexts) relates to a group mean difference in risk perception - a pattern exemplified greatest in young-adults (ages 18-21). The results are suggestive of a specified functional brain phenotype that relates to being at "risk to be risky.