Active Inference and Learning in the Cerebellum

This letter offers a computational account of Pavlovian conditioning in the cerebellum based on active inference and predictive coding. Using eyeblink conditioning as a canonical paradigm, we formulate a minimal generative model that can account for spontaneous blinking, startle responses, and (delay or trace) conditioning. We then establish the face validity of the model using simulated responses to unconditioned and conditioned stimuli to reproduce the sorts of behavior that are observed empirically. The scheme’s anatomical validity is then addressed by associating variables in the predictive coding scheme with nuclei and neuronal populations to match the (extrinsic and intrinsic) connectivity of the cerebellar (eyeblink conditioning) system. Finally, we try to establish predictive validity by reproducing selective failures of delay conditioning, trace conditioning, and extinction using (simulated and reversible) focal lesions. Although rather metaphorical, the ensuing scheme can account for a remarkable range of anatomical and neurophysiological aspects of cerebellar circuitry—and the specificity of lesion-deficit mappings that have been established experimentally. From a computational perspective, this work shows how conditioning or learning can be formulated in terms of minimizing variational free energy (or maximizing Bayesian model evidence) using exactly the same principles that underlie predictive coding in perception

Rigid body motion in viscous flows using the Finite Element Method

A new model for the numerical simulation of a rigid body moving in a viscous fluid flow using FEM is presented. One of the most interesting features of this approach is the small computational effort required to solve the motion of the rigid body, comparable to a pure fluid solver. The model is based on the idea of extending the fluid velocity inside the rigid body and solving the flow equations with a penalization term to enforce rigid motion inside the solid. In order to get the velocity field in the fluid domain the Navier-Stokes equations for an incompressible viscous flow are solved using a fractional-step procedure combined with the two-step Taylor-Galerkin for the fractional linear momentum. Once the velocity field in the fluid domain is computed, calculation of the rigid motion is obtained by averaging translation and angular velocities over the solid. One of the main challenges when dealing with the fluid-solid interaction is the proper modelling of the interface which separates the solid moving mass from the viscous fluid. In this work the combination of the level set technique and the two-step Taylor-Galerkin algorithm for tracking the fluid-solid interface is proposed. The good properties exhibited by the two-step Taylor-Galerkin, minimizing oscillations and numerical diffusion, make this method suitable to accurately advect the solid domain avoiding distortions at its boundaries, and thus preserving the initial size and shape of the rigid body. The proposed model has been validated against empirical solutions, experimental data and numerical simulations found in the literature. In all tested cases, the numerical results have shown to be accurate, proving the potential of the proposed model as a valuable tool for the numerical analysis of the fluid-solid interaction.Comment: Research article; 41 pages, 40 figures, 5 tables, 91 reference

A broken socioeconomic promotion: Palma del Río and the case of the morisco Alonso de Almerique

Aunque todavía sabemos poco acerca de los moriscos granadinos que fueron expulsados a Castilla entre 1570 y 1610, algo que empieza a quedar claro es la existencia de una fuerte estructuración interna, tema ignorado hasta hace pocos años. Este artículo se centra en la figura del morisco Alonso Fernández de Almerique, asentado en la villa cordobesa de Palma del Río, quien no sólo consiguió enriquecerse gracias a muy diversas actividades económicas, sino que casi logró hacer olvidar su condición originaria.We still do not know much about the moriscos who were expelled from Granada to Castile between 1570 and 1610, something that is becoming clear, though, is the existence of a strong internal structure, an unkown issue until recent years. This paper focuses on Alonso Fernández de Almerique, a morisco settled in the cordovan town of Palma del Río, who not only got rich thanks to various economic activities, but even nearly managed to make forget his origins

Validation of a gas chromatography-mass spectrometry method for the analysis of sterol oxidation products in serum

A validated gas chromatography-mass spectrometry (GC-MS) detection method for the quantitative analysis of sterol oxidation products (SOPs) in serum is described. After a lipid extraction procedure with chloroform-methanol, a cold saponification and purification by solid phase extraction, oxysterols were derivatized to form trimethyl-sylil-ethers which were subjected to GC-MS analysis. Calibration curves for cholesterol oxidation products showed determination coefficient (R(2)) of 1.0, with low values for the coefficient of variation of the response factors (< 1%). Detection and quantification limits were below 5 ng/mL and 10 ng/mL, respectively. Recovery data were between 77.65% and 110.29% (CV < 10% for all compounds). Good results were obtained for within- and between-day repeatability, with values below 10%. In conclusion, the method performed is suitable for the determination and quantification of SOPs in serum

Discriminación por obesidad en el ámbito laboral

Este trabajo parte de la existencia de discriminación por obesidad en diferentes ámbitos de la vida, como el laboral o el acceso a ciertos bienes y servicios, y precisamente en sus primeras páginas se describen algunos supuestos de esa posible discriminación que han sido juzgados por los tribunales. El propio legislador español también parece considerar dicha forma de discriminación al prohibirla expresamente en la Ley 17/2011, de 5 de julio, de seguridad alimentaria y nutrición, aun cuando se trate de una prohibición un tanto singular y de dudosa eficacia. Bajo esta premisa, el objeto principal del trabajo es analizar qué mecanismos jurídicos de protección se pueden arbitrar frente a supuestos de discriminación por obesidad. En este sentido, analizamos en primer lugar si este tipo de discriminación supone una lesión del derecho fundamental a la propia imagen. Contemplamos también la obesidad como una enfermedad y, en tanto que tal, valoramos si estamos antes una discriminación por enfermedad. Y nos preguntamos igualmente si la obesidad es un motivo de discapacidad, con la subsiguiente discriminación por discapacidad. Por último, analizamos la importante sentencia del Tribunal de Justicia de la Unión Europea, de 18 desde diciembre de 2014 (C-354/13), que precisamente arroja luz sobre el objeto de este estudio.This work affirms the existence of obesity discrimination in different areas of life, such as employment or access to certain goods and services, and precisely in its first pages some assumptions of this possible discrimination that have been tried by the courts are described.. The Spanish legislator himself also seems to consider this form of discrimination by expressly prohibiting it in Law 17/2011, of July 5, on food security and nutrition, even if it is a somewhat unique and doubtful prohibition.Under this premise, the main purpose of the work is to analyze what legal protection mechanisms are possible against cases of discrimination based on obesity. We analyze first of all, if this type of discrimination implies an injury to the fundamental right. Next, we contemplate obesity as a disease and, as such, we assess whether we are before a disease discrimination. And we also wonder if obesity is a reason for disability, with subsequent disability discrimination. Finally, we analyze the important ruling of the Court of Justice of the European Union, dated 18 December 2014 (C-354/13), which precisely sheds light on the object of this study.2020-2

Evaluación de la conducta activa: el Registro Semanal de Actividad Física (RSAF)

The aim of this study was to propose the Weekly Physical Activity Log (RSAF in Spanish) to assess physical activity behaviour in adults. To this end, 132 adults (mean = 28.53 years; SD = 11.20) completed the RSAF. The energy expenditure (METs) of daily physical activities was obtained for a week and the percentile scores were calculated in terms of gender and age. The energy expenditure data were compared with the physical activity level and measures of fitness. The results show that active participants tend to have higher energy expenditure level than non-active participants, and the correlation between aerobic fitness and average weekly energy consumption is significant. These results show that the RSAF is useful and suitable for assessing daily physical activity and fitness in adults

Boulder exhumation and segregation by impacts on rubble-pile asteroids

Small asteroids are often considered to be rubble-pile objects, and such asteroids may be the most likely type of Near Earth Objects (NEOs) to pose a threat to Earth. However, impact cratering on such bodies is complex and not yet understood. We perform three low-velocity (≈ 400 m/s) impact experiments in granular targets with and without projectile-size boulders. We conducted SPH simulations that closely reproduced the impact experiments. Our results suggest that cratering on heterogeneous targets displaces and ejects boulders, rather than fragmenting them, unless directly hit. We also see indications that as long as the energy required to disrupt the boulder is small compared to the kinetic energy of the impact, the disruption of boulders directly hit by the projectile may have minimal effect on the crater size. The presence of boulders within the target causes ejecta curtains with higher ejection angles compared to homogeneous targets. At the same time, there is a segregation of the fine ejecta from the boulders, resulting in boulders landing at larger distances than the surrounding fine grained material. However, boulders located in the target near the maximum extent of the expanding excavation cavity are merely exhumed and distributed radially around the crater rim, forming ring patterns similar to the ones observed on asteroids Itokawa, Ryugu and Bennu. Altogether, on rubble-pile asteroids this process will redistribute boulders and finer-grained material heterogeneously, both areally around the crater and vertically in the regolith. In the context of a kinetic impactor on a rubble-pile asteroid and the DART mission, our results indicate that the presence of boulders will reduce the momentum transfer compared to a homogeneous, fine-grained target

Colonoscopy versus fecal immunochemical testing in colorectal-cancer screening

Colonoscopy and fecal immunochemical testing (FIT) are accepted strategies for colorectal-cancer screening in the average-risk population. METHODS: In this randomized, controlled trial involving asymptomatic adults 50 to 69 years of age, we compared one-time colonoscopy in 26,703 subjects with FIT every 2 years in 26,599 subjects. The primary outcome was the rate of death from colorectal cancer at 10 years. This interim report describes rates of participation, diagnostic findings, and occurrence of major complications at completion of the baseline screening. Study outcomes were analyzed in both intention-to-screen and as-screened populations. RESULTS: The rate of participation was higher in the FIT group than in the colonoscopy group (34.2% vs. 24.6%, P<0.001). Colorectal cancer was found in 30 subjects (0.1%) in the colonoscopy group and 33 subjects (0.1%) in the FIT group (odds ratio, 0.99; 95% confidence interval [CI], 0.61 to 1.64; P=0.99). Advanced adenomas were detected in 514 subjects (1.9%) in the colonoscopy group and 231 subjects (0.9%) in the FIT group (odds ratio, 2.30; 95% CI, 1.97 to 2.69; P<0.001), and nonadvanced adenomas were detected in 1109 subjects (4.2%) in the colonoscopy group and 119 subjects (0.4%) in the FIT group (odds ratio, 9.80; 95% CI, 8.10 to 11.85; P<0.001). CONCLUSIONS: Subjects in the FIT group were more likely to participate in screening than were those in the colonoscopy group. On the baseline screening examination, the numbers of subjects in whom colorectal cancer was detected were similar in the two study groups, but more adenomas were identified in the colonoscopy groupSupported by grants from Asociación Española contra el Cáncer (Fundación Científica and Junta de Barcelona), Instituto de Salud Carlos III (PI08/90717), FEDER funds, and Agència de Gestió d’Ajuts Universitaris i de Recerca (2009SGR849). Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) is funded by Instituto de Salud Carlos III. In the Basque Country, the study received additional grants from Obra Social de Kutxa, Diputación Foral de Gipuzkoa (DFG 07/5), Departamento de Sanidad del Gobierno Vasco, EITB-Maratoia (BIO 07/ CA/19), and Acción Transversal contra el Cáncer del CIBERehd (2008). In Galicia, this work was supported by Dirección Xeral de Innovación e Xestión da Saúde Pública, Conselleria de Sanidade, and Xunta de Galicia. Eiken Chemical of Japan and its Spanish representatives, Palex Medical and Biogen Diagnóstica, donated supplies and automated analyzers used for FI