239 research outputs found

    Effects of gaze on vection from jittering, oscillating, and purely radial optic flow

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    In this study, we examined the effects of different gaze types (stationary fixation, directed looking, or gaze shifting) and gaze eccentricities (central or peripheral) on the vection induced by jittering, oscillating, and purely radial optic flow. Contrary to proposals of eccentricity independence for vection (e.g., Post, 1988), we found that peripheral directed looking improved vection and peripheral stationary fixation impaired vection induced by purely radial flow (relative to central gaze). Adding simulated horizontal or vertical viewpoint oscillation to radial flow always improved vection, irrespective of whether instructions were to fixate, or look at, the center or periphery of the self-motion display. However, adding simulated high-frequency horizontal or vertical viewpoint jitter was found to increase vection only when central gaze was maintained. In a second experiment, we showed that alternating gaze between the center and periphery of the display also improved vection (relative to stable central gaze), with greater benefits observed for purely radial flow than for horizontally or vertically oscillating radial flow. These results suggest that retinal slip plays an important role in determining the time course and strength of vection. We conclude that how and where one looks in a self-motion display can significantly alter vection by changing the degree of retinal slip

    El triple desarrollo de Segismundo: ontogenia, filogenia y determinismo social

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    Este artículo utiliza conceptos neurocientíficos para mostrar una evolución de Segismundo en La vida es sueño con más dimensiones que la meramente social o individual, acercándonos a la propia historia de la especie en su uso de los diferentes atributos que va confiriendo a su personaje a lo largo de la obra. Segismundo no sólo es un prisionero que acaba ocupando su puesto como príncipe, sino que también es el ejemplo del proceso ideal de maduración del hombre y, al mismo tiempo, de la evolución que va de la bestia al ser humano, poniendo especial énfasis en la capacidad analítico-racional como cualidad propia e imprescindible del hombre ideal. Para ello se estudia el modelo del cerebro triuno, identificando las distintas partes del cerebro (cerebro reptil, sistema límbico y neocórtex) y relacionando su evolución temporal y en áreas de especialización con las diferentes etapas de Segismundo en esta triple vertiente, para converger en el hombre ideal propuesto por Calderón. // This paper uses neuroscientific concepts to show an evolution of Segismundo in La vida es sueño in more dimensions than the social or individual ones, linking it to our species’ own history in the way he uses the different attributes he confers to his character during the play. Segismundo is not only a prisoner who ends up taking up his position as prince, but also an example of the ideal process of Man’s development and, at the same time, of the evolution that takes place from the animal to the human being, with special emphasis on the rational and analytical capacity as fundamental and irreplaceable feature of the ideal man.To exemplify this I will use the model of the triune brain, identifying the different parts of the brain (reptilian brain, the limbic system and the neocortex) and relating their different evolution along time and areas of specialization with the three different stages of Segismundo’s evolution, thus converging in the model of the ideal man suggested by Calderón

    Dynamo in Weakly Collisional Nonmagnetized Plasmas Impeded by Landau Damping of Magnetic Fields

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    We perform fully kinetic simulations of flows known to produce dynamo in magnetohydrodynamics (MHD), considering scenarios with low Reynolds number and high magnetic Prandtl number, relevant for galaxy cluster scale fluctuation dynamos. We find that Landau damping on the electrons leads to a rapid decay of magnetic perturbations, impeding the dynamo. This collisionless damping process operates on spatial scales where electrons are nonmagnetized, reducing the range of scales where the magnetic field grows in high magnetic Prandtl number fluctuation dynamos. When electrons are not magnetized down to the resistive scale, the magnetic energy spectrum is expected to be limited by the scale corresponding to magnetic Landau damping or, if smaller, the electron gyroradius scale, instead of the resistive scale. In simulations we thus observe decaying magnetic fields where resistive MHD would predict a dynamo

    State-Level Policy Environments, Discrimination, and Victimization among Sexual and Gender Minority People

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    Legislation has been passed in some states to reduce discrimination and victimization toward sexual and gender minority people (SGM; people who are not solely heterosexual and/or whose gender identity is not equal to what is socially associated with sex assigned at birth). The purpose of these analyses is to test whether state-level policy environments are associated with past-year discrimination and victimization among SGM people. Cross-sectional data from The Population Research in Identity and Disparities for Equality (PRIDE) Study annual questionnaire (collected 2018–2019), a national study of the health of SGM adults in the USA, were used for these analyses. Measures included related to discrimination, victimization, and demographic characteristics. State-level policy environments were measured using data from the Movement Advancement Project. Logistic regression analyses evaluated state-level policy environment scores and past-year discrimination and victimization among gender identity categories. In this sample, 7044 people (gender minority n = 2530) were included. Cisgender sexual minority (odds ratio [OR] = 1.007, p = 0.041) and the gender expansive subgroup of gender minority people (OR = 1.010, p = 0.047) in states with more protective policy environments had greater odds of discrimination. The gender expansive subgroup was found to have greater odds of victimization in states with more protective policy environments (OR = 1.003, p \u3c 0.05). There was no relationship between state-level policy environments and victimization among any other study groups. SGM people may experience increased risk for discrimination and victimization despite legislative protections, posing continued risks for poor health outcomes and marginalization. Evaluation of factors (e.g., implementation strategies, systems of accountability) that influence the effectiveness of state-level polices on the reported experiences of discrimination and victimization among SGM people is needed

    Gut epithelial barrier damage caused by dishwasher detergents and rinse aids

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    Background: The increased prevalence of many chronic inflammatory diseases linked to gut epithelial barrier leakiness has prompted us to investigate the role of extensive use of dishwasher detergents, among other factors. Objective: We sought to investigate the effects of professional and household dishwashers, and rinse agents, on cytotoxicity, barrier function, transcriptome, and protein expression in gastrointestinal epithelial cells. Methods: Enterocytic liquid-liquid interfaces were established on permeable supports, and direct cellular cytotoxicity, transepithelial electrical resistance, paracellular flux, immunofluorescence staining, RNA-sequencing transcriptome, and targeted proteomics were performed. Results: The observed detergent toxicity was attributed to exposure to rinse aid in a dose-dependent manner up to 1:20,000 v/v dilution. A disrupted epithelial barrier, particularly by rinse aid, was observed in liquid-liquid interface cultures, organoids, and gut-on-a-chip, demonstrating decreased transepithelial electrical resistance, increased paracellular flux, and irregular and heterogeneous tight junction immunostaining. When individual components of the rinse aid were investigated separately, alcohol ethoxylates elicited a strong toxic and barrier-damaging effect. RNA-sequencing transcriptome and proteomics data revealed upregulation in cell death, signaling and communication, development, metabolism, proliferation, and immune and inflammatory responses of epithelial cells. Interestingly, detergent residue from professional dishwashers demonstrated the remnant of a significant amount of cytotoxic and epithelial barrier-damaging rinse aid remaining on washed and ready-to-use dishware. Conclusions: The expression of genes involved in cell survival, epithelial barrier, cytokine signaling, and metabolism was altered by rinse aid in concentrations used in professional dishwashers. The alcohol ethoxylates present in the rinse aid were identified as the culprit component causing the epithelial inflammation and barrier damage. Keywords: Alcohol ethoxylates; Caco-2; cytotoxicity; dishwasher detergents; epithelial barrier; inflammation; rinse aid
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