Simplifying robotic locomotion by escaping traps via an active tail

Legged systems offer the ability to negotiate and climb heterogeneous terrains, more so than their wheeled counterparts \cite{freedberg_2012}. However, in certain complex environments, these systems are susceptible to failure conditions. These scenarios are caused by the interplay between the locomotor's kinematic state and the local terrain configuration, thus making them challenging to predict and overcome. These failures can cause catastrophic damage to the system and thus, methods to avoid such scenarios have been developed. These strategies typically take the form of environmental sensing or passive mechanical elements that adapt to the terrain. Such methods come at an increased control and mechanical design complexity for the system, often still being susceptible to imperceptible hazards. In this study, we investigated whether a tail could serve to offload this complexity by acting as a mechanism to generate new terradynamic interactions and mitigate failure via substrate contact. To do so, we developed a quadrupedal C-leg robophysical model (length and width = 27 cm, limb radius = 8 cm) capable of walking over rough terrain with an attachable actuated tail (length = 17 cm). We investigated three distinct tail strategies: static pose, periodic tapping, and load-triggered (power) tapping, while varying the angle of the tail relative to the body. We challenged the system to traverse a terrain (length = 160 cm, width = 80 cm) of randomized blocks (length and width = 10 cm, height = 0 to 12 cm) whose dimensions were scaled to the robot. Over this terrain, the robot exhibited trapping failures independent of gait pattern. Using the tail, the robot could free itself from trapping with a probability of 0 to 0.5, with the load-driven behaviors having comparable performance to low frequency periodic tapping across all tested tail angles. Along with increasing this likelihood of freeing, the robot displayed a longer survival distance over the rough terrain with these tail behaviors. In summary, we present the beginning of a framework that leverages mechanics via tail-ground interactions to offload limb control and design complexity to mitigate failure and improve legged system performance in heterogeneous environments.M.S

Out of many, más : imagining a U.S. Latino political audience

textU.S. Latino political integration is a theme that has entered the public agenda in recent years, advanced by both professionals and scholars. However, most political actors have ignored the tremendous racial and socio-economic differences in American Latino communities. Many political actors have made fundamental assumptions about what constitutes the American Latino experience, including overemphasizing the language and other cultural similarities of these populations while disregarding their different experiences of race and class. This thesis analyzes how political actors, including American Presidents, Latino civic organizations, Spanish media and Latino youth, have constructed Latino pan-ethnicism through their rhetoric. To investigate this question, a multi-method analysis of rhetoric and political communication directed towards or about U.S. Latinos was conducted. Data indicates that official participants in U.S. Latino racial formation, Presidents and Civic Organizations, are rapidly constructing pan-ethnic rhetoric while other non-official participants challenge and deconstruct pan-ethnic rhetoric. The normative value of this thesis represents a contribution to the question of Latino inclusion in the United States, as well as complicating traditional notions of assimilation and political acculturation. Finally, this work challenges American Latinos to critically reflect on their own identity formation, and how they may begin to reclaim it.Radio-Television-Fil

Bases para la traducción-recreación al español de poemas escritos en francés

El objetivo de este artículo, de corte eminentemente didáctico, es el de proponer al estudiante de traducción literaria una práctica serie de bases encaminadas al desarrollo de estrategias que le ayuden a superar, gracias a la traductología, a los estudios literarios y a la métrica, algunos de los problemas que suele plantear la práctica de la traducción poética al español de poemas escritos en francés. Para ello se reflexiona sobre las implicaciones teóricas más significativas de la traducción poética en la combinación francés-español y se presentan, con el fin de ilustrarlas, dos ejemplos de traducción poética.G.I. HUM 767 (ayudas a Grupos de Investigación de la Junta de Andalucía) / Editorial Comares (colección interlingua

Synaptic remodeling of neuronal circuits in early retinal degeneration

Photoreceptor degenerations are a major cause of blindness and among the most common forms of neurodegeneration in humans. Studies of mouse models revealed that synaptic dysfunction often precedes photoreceptor degeneration, and that abnormal synaptic input from photoreceptors to bipolar cells causes circuits in the inner retina to become hyperactive. Here, we provide a brief overview of frequently used mouse models of photoreceptor degenerations. We then discuss insights into circuit remodeling triggered by early synaptic dysfunction in the outer and hyperactivity in the inner retina. We discuss these insights in the context of other experimental manipulations of synaptic function and activity. Knowledge of the plasticity and early remodeling of retinal circuits will be critical for the design of successful vision rescue strategies

One-Year Effects of Project EX in Spain: A Classroom-Based Smoking Prevention and Cessation Intervention Program.

BackgroundTobacco use prevalence rates are high among Spanish adolescents. Programming to counteract tobacco use is needed.Methods and findingsThe current study provides a one-year follow-up outcome evaluation of Project EX, an eight-session classroom-based curriculum. The intervention was tested using a randomized controlled trial with 1,546 Spanish students, involving three program and three control schools. Compared to the control condition, the program condition revealed a greater reduction in nicotine dependence (p < .05) and CO ppm levels (p < .001), and lower consumption of cigarettes at last month (p = .03).ConclusionsLong-term outcomes of the Project EX classroom-based program are promising for adolescent prevention and possibly cessation in Spain

Nanocomposites with shape memory behavior based on a segmented polyurethane and magnetic nanostructures

Shape-memory composites based on a commercial segmented polyurethane and magnetite (Fe⁠3O⁠4) nanoparticles(NPs) were prepared by a simple suspension casting method. The properties of the resulting nanocomposites,containing 1 to 10 nominal wt.% magnetic particles, were evaluated by thermogravimetric tests, contact anglemeasurements, differential scanning calorimetry, infrared and X-ray spectroscopy, static and thermal cyclic tensiletests, dynamic mechanical analysis and experiments of alternating-magnetic-field heating. It was found thatmost of the suspended NPs could be successfully incorporated into the polyurethane matrix, and thus compositesamples with up to 7 wt.% actual concentration were obtained. On the other hand, the incorporation of magnetitenanoparticles to the shape memory polyurethane did not significantly affect most of the matrix properties,including its shape memory behavior, while added magnetic response to the nanocomposites. Thus, nanocompositeswere able to increase their temperature when exposed to an alternating magnetic field, which allowedthem to recover their original shape quickly by an indirect triggering method.Fil: Soto, Guillermo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Meiorin, Cintia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Actis, Daniel Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Mendoza Zélis, Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Mosiewicki, Mirna Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Marcovich, Norma Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

How do Latin American migrants in the U.S. stand on schooling premium? What does it reveal about education quality in their home countries?

Indicators for quality of schooling are not only relatively new in the world but also unavailable for a sizable share of the world’s population. In their absence, some proxy measures have been devised. One simple but powerful idea has been to use the schooling premium for migrant workers in the U.S. (Bratsberg and Terrell 2002). In this paper we extend this idea and compute measures for the schooling premium of immigrant workers in the U.S over a span of five decades. Focusing on those who graduated from either secondary or tertiary education in Latin American countries, we present comparative estimates of the evolution of such premia for both schooling levels. The results show that the schooling premia in Latin America have been steadily low throughout the whole period of analysis. The results stand after controlling for selective migration in different ways. This contradicts the popular belief in policy circles that the education quality of the region has deteriorated in recent years. In contrast, schooling premium in India shows an impressive improvement in recent decades, especially at the tertiary level.Los indicadores de la calidad de la escolaridad no solo son relativamente nuevos en el mundo, sino que tampoco están disponibles para una proporción considerable de la población mundial. En su ausencia, se han ideado algunas medidas proxy. Una idea simple, pero poderosa, ha sido la de utilizar los premios a la escolaridad - entendidos como el ingreso adicional que los trabajadores son capaces de generar por cada año adicional de estudios - para los trabajadores migrantes en los Estados Unidos (Bratsberg y Terrell 2002). En este trabajo, los autores amplían esta idea y calculan medidas para los premios a la escolaridad de trabajadores inmigrantes en los Estados Unidos a lo largo de cinco décadas. Enfocándose en los egresados de la educación secundaria o terciaria en países de América Latina, los investigadores presentan estimaciones comparativas de la evolución de tales premios para ambos niveles de escolaridad. Los hallazgos muestran que los premios a la escolaridad en América Latina han sido constantemente bajos durante todo el periodo de análisis. Los resultados se mantienen luego de controlar la migración selectiva de distintas maneras. Esto contradice la creencia popular en los círculos de política de que la calidad de la educación de la región se ha deteriorado en los años recientes. Por el contrario, los premios a la escolaridad en la India muestran una mejora impresionante en las últimas décadas, en especial en el nivel terciario

An excitatory amacrine cell detects object motion and provides feature-selective input to ganglion cells in the mouse retina

Retinal circuits detect salient features of the visual world and report them to the brain through spike trains of retinal ganglion cells. The most abundant ganglion cell type in mice, the so-called W3 ganglion cell, selectively responds to movements of small objects. Where and how object motion sensitivity arises in the retina is incompletely understood. In this study, we use 2-photon-guided patch-clamp recordings to characterize responses of vesicular glutamate transporter 3 (VGluT3)-expressing amacrine cells (ACs) to a broad set of visual stimuli. We find that these ACs are object motion sensitive and analyze the synaptic mechanisms underlying this computation. Anatomical circuit reconstructions suggest that VGluT3-expressing ACs form glutamatergic synapses with W3 ganglion cells, and targeted recordings show that the tuning of W3 ganglion cells' excitatory input matches that of VGluT3-expressing ACs' responses. Synaptic excitation of W3 ganglion cells is diminished, and responses to object motion are suppressed in mice lacking VGluT3. Object motion, thus, is first detected by VGluT3-expressing ACs, which provide feature-selective excitatory input to W3 ganglion cells. DOI: http://dx.doi.org/10.7554/eLife.08025.00