From sensorimotor dependencies to perceptual practices: making enactivism social

Proponents of enactivism should be interested in exploring what notion of action best captures the type of action-perception link that the view proposes, such that it covers all the aspects in which our doings constitute and are constituted by our perceiving. This article proposes and defends the thesis that the notion of sensorimotor dependencies is insufficient to account for the reality of human perception, and that the central enactive notion should be that of perceptual practices. Sensorimotor enactivism is insufficient because it has no traction on socially dependent perceptions, which are essential to the role and significance of perception in our lives. Since the social dimension is a central desideratum in a theory of human perception, enactivism needs a notion that accounts for such an aspect. This article sketches the main features of the Wittgenstein-inspired notion of perceptual practices as the central notion to understand perception. Perception, I claim, is properly understood as woven into a type of social practices that includes food, dance, dress, music, etc. More specifically, perceptual practices are the enactment of culturally structured, normatively rich techniques of commerce of meaningful multi- and inter-modal perceptible material. I argue that perceptual practices explain three central features of socially dependent perception: attentional focus, aspects’ saliency, and modal-specific harmony-like relations

Aspectos sociales en tres poemas de Cantos de vida y esperanza, de Rubén Darío: «Salutación del optimista», «Los cisnes», N.º 1, y «A Roosevelt».

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Correlación simbólica en la estructura tripartita con el tono épico en Los de abajo, de Mariano Azuela.

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Structural Evaluation of Bamboo Bike Frames: Experimental and Numerical Analysis

Construction of bicycles with bamboo frames has become an alternative to improve the quality of life of some communities, be friendly with the environment and be ecologically sustainable. However, the production of bike frames is made in an artisanal way and there are few antecedents that have proven their reliability. This work presents the evaluation and simulation of the mechanical behavior of bike frames made in bamboo. Three-points bending tests were performed using bamboo bars with similar dimensions to bike frames, and an equivalent elasticity modulus was determined and used as the input datum of a finite element model. A linear model material and beam elements were used to model the bike frame. Tests were performed using bike frames of bamboo applying loads greater than 7000 N, and the displacements were measured. The experimental displacements were used to calibrate the model, which consisted of modifying the rigidity of the connections until the displacements of the model fit near to 90%. The calibrated model was used for a fatigue simulation in order to predict the lifespan of the bike frame. Some technical values of bamboo bike frames were obtained so that these will allow them to define the technical characteristics of the product and guarantee their operating conditions

Land use influences the spatiotemporal controls on nitrification and denitrification in headwater streams

N and C cycles in headwater streams are coupled, and land use can modify these cycles by increasing N availability and removing riparian vegetation. To increase our understanding of how land use modifies the controls on N cycling, we quantified rates of 2 microbial N transformations in a total of 18 agricultural and urban streams (with and without riparian buffers) for 3 y to examine how riparian vegetation and land use influence sediment nitrification and denitrification. Nitrification rates were highest in agricultural streams in late spring. Nitrification was not related to streamwater NH4+ concentrations but was positively related to sediment C content (linear regression, r2 = 0.72, p \u3c 0.001). This result suggests that benthic decomposition provided NH4+ (via mineralization) to increase sediment nitrification. Denitrification rates did not differ among landuse types but were positively related to sediment C content and streamwater NO3– concentration (multiple linear regression, R2 = 0.78, p \u3c 0.001). Sediment C content, the primary predictor of denitrification rates, did not differ among land uses, but streamwater NO3– concentration, the secondary predictor of denitrification rates, was highest in winter and in agricultural streams, indicating that land use and season were more important determinants of denitrification than coupled nitrification. Substrate availability (N and C) for N transformations generally did not differ between buffered and unbuffered streams within a similar landuse type, probably because of the confounding influence of tile drainage systems, which effectively decouple stream channels from their riparian zones. Land use influenced the delivery of the necessary substrates for N transformations but decreased the role of riparian zones in stream N cycling by simplifying the drainage network of headwater streams

Associations between physical fitness and adiposity among school-age children from Monteria, Colombia

Los niveles bajos de condición física se han asociado con adiposidad elevada. Ambas condiciones pueden predecir alteraciones cardiovasculares y metabólicas. El objetivo fue analizar la relación entre la condición física y los indicadores antropométricos de adiposidad. Estudio transversal, en 534 escolares de 6 a 12 años de edad del municipio de Montería. Se midió la condición cardiorrespiratoria (CCR), flexibilidad, fuerza explosiva de miembros inferiores (FEMI), fuerza resistencia abdominal (FRA), Índice de Masa Corporal (IMC), masa adiposa (PMA), y perímetro abdominal (PA). Las asociaciones entre adiposidad y la condición física se analizaron con modelos de regresión logística. Se encontró que el sobrepeso está asociado a baja CCR (ORa = 2,7, p<0,0001); el PA elevado está asociado a baja FRA (ORa = 2,2, p<0,02), y a baja CCR (ORa = 3,3, p<0,001); el PMA elevado está asociado a baja CCR (ORa = 2,7, p<0,0001). Conclusión, la condición física está asociada a la adiposidadLow physical fitness levels have been associated with elevated adiposity. Both conditions may predict cardiovascular and metabolic alterations. The objective was to analyze the associations between health-related physical fitness and adipose. A cross-sectional study in 534 school-age children aged 6-12 in Monteria, Colombia. Measurements included cardiorespiratory fitness (CCR), flexibility, explosive strength of lower limbs (FEMI), abdominal strength endurance (ASE), body mass index (BMI), percentage of adipose mass (PAM), and waist circumference (WC). The associations between adiposity and physical fitness were calculated by logistic regression models. Results indicate that overweight is associated with low CCR (aOR = 2.7, p<0.0001). Elevated PA was associated with low ASE (aOR = 2.2, p<0.02), and with low CCR (aOR = 3.3, p<0.001). Elevated PMA was associated with low CCR (aOR=2.7, p<0.0001). In conclusion, physical fitness is associated with adiposity

Gender, Personality, and Cognitive Resilience Against Early-Life Disadvantage

Objectives: Early-life disadvantage (ELD) relates to lower late-life cognition. However, personality factors, including having an internal locus of control (LOC) or a conscientious personality, relate to resilience and effective stress coping. We explore whether personality factors convey resilience against the negative effects of ELD on cognition, by gender, in Mexico. Methods: Using the 2015 Mexican Health and Aging Study, we estimated expected cognition using multiple ELD markers to identify a subsample in the lowest quartile of expected cognition given ELD (n = 2,086). In this subsample, we estimated cross-sectional associations between personality and having above-median observed cognitive ability (n = 522) using logistic regression. Results: Among those in the lowest quartile of expected cognition, a more internal LOC (β = 0.32 [men] and β = 0.44 [women]) and conscientious personality (β = 0.39 [men] and β = 0.17 [women]) were significantly associated with having above-median cognitive ability in models adjusted for demographic confounders. Larger benefits of conscientiousness were observed for men than women. Associations between personality and having above-median cognitive ability remained statistically significant after further adjustment for health, stress, and cognitive stimulation variables, regardless of gender. Discussion: Personality factors may convey resilience among individuals who experienced ELD, potentially breaking the link between ELD and worse late-life cognition. Structural factors and gender roles may affect how much women benefit from personality factors

Ubiquity of optical activity in planar metamaterial scatterers

Recently it was discovered that periodic lattices of metamaterial scatterers show optical activity, even if the scatterers or lattice show no 2D or 3D chirality, if the illumination breaks symmetry. In this Letter we demonstrate that such `pseudo-chirality' is intrinsic to any single planar metamaterial scatterer and in fact has a well-defined value at a universal bound. We argue that in any circuit model, a nonzero electric and magnetic polarizability derived from a single resonance automatically imply strong bianisotropy, i.e., magneto-electric cross polarizability at the universal bound set by energy conservation. We confirm our claim by extracting polarizability tensors and cross sections for handed excitation from transmission measurements on near-infrared split ring arrays, and electrodynamic simulations for diverse metamaterial scatterers.Comment: 5 pages, 4 figure

Abundance and size of birds determine the position of the species in plant-frugivore interaction networks in fragmented forests

Abstract The relationships between frugivorous animals and plants are of vital importance particularly in tropical forests. The way species interact and how they are organized within interaction networks could be determined by their ecological and morphological characteristics. This study evaluates the hypothesis that the topological position of species within an interaction network is determined by their degree of frugivory, body size, and abundance. Thus, we constructed the frugivory network between birds and plants in a rainforest fragment in northwestern Colombia. The position of the species within the network was calculated based on three centrality measures (degree, betweenness, and closeness), and its association with relative abundance, degree of frugivory, and body size of each bird species was evaluated by means of a generalized linear model. We found that the species that were most abundant and had the smallest body size had central positions in the interaction network. This pattern is contrary to what has been observed in pristine forests, where species with large body size are more important for network stability. Our results suggest that forest fragmentation modifies the roles of species within the network structure, in part, due to changes in the makeup of the original frugivore community. The information presented may be useful to evaluate the effects of the loss of species as a result of anthropic actions, with the aim of generating ecosystem restoration strategies