Signs of Language: Embodied Sign Language Fingerspelling Acquisition from Demonstrations for Human-Robot Interaction

Learning fine-grained movements is a challenging topic in robotics, particularly in the context of robotic hands. One specific instance of this challenge is the acquisition of fingerspelling sign language in robots. In this paper, we propose an approach for learning dexterous motor imitation from video examples without additional information. To achieve this, we first build a URDF model of a robotic hand with a single actuator for each joint. We then leverage pre-trained deep vision models to extract the 3D pose of the hand from RGB videos. Next, using state-of-the-art reinforcement learning algorithms for motion imitation (namely, proximal policy optimization and soft actor-critic), we train a policy to reproduce the movement extracted from the demonstrations. We identify the optimal set of hyperparameters for imitation based on a reference motion. Finally, we demonstrate the generalizability of our approach by testing it on six different tasks, corresponding to fingerspelled letters. Our results show that our approach is able to successfully imitate these fine-grained movements without additional information, highlighting its potential for real-world applications in robotics

DNA Molecular Storage System: Transferring Digitally Encoded Information through Bacterial Nanonetworks

Since the birth of computer and networks, fuelled by pervasive computing and ubiquitous connectivity, the amount of data stored and transmitted has exponentially grown through the years. Due to this demand, new solutions for storing data are needed, and one promising media is the DNA. This storage solution provides numerous advantages, which includes the ability to store dense information while achieving long-term stability. However, the question as how the data can be retrieved from a DNA-based archive, still remains. In this paper, we aim to address this question by proposing a new storage solution that relies upon molecular communication, and in particular bacterial nanonetworks. Our solution allows digitally encoded information to be stored into non-motile bacteria, which compose an archival architecture of clusters, and to be later retrieved by engineered motile bacteria, whenever reading operations are needed. We conducted extensive simulations, in order to determine the reliability of data retrieval from non-motile storage clusters, placed at different locations. Aiming to assess the feasibility of our solution, we have also conducted wet lab experiments that show how bacteria nanonetworks can effectively retrieve a simple message, such as "Hello World", by conjugation with non-motile bacteria, and finally mobilize towards a final point.Comment: 22 pages, 13 figures; removed wrong venue references, reordered bibliography accordingly to ACM guideline

Diseño y construcción de una plataforma experimental de evaluación de sistemas híbridos basados en pilas de combustible

Este trabajo consiste en el estudio, diseño, construcción y validación experimental de una plataforma para la evaluación de Sistemas Híbridos de Generación de Energía (SHGE) a partir de pilas de combustible de hidrógeno. La herramienta desarrollada permitirá el diseño y propuesta de nuevas estrategias de control que optimicen la extracción de energía de los sistemas híbridos. En este contexto, el sistema propuesto se encuentra conformado principalmente por un convertidor electrónico de potencia de CC-CC conmutado y aislado, con topología tipo Puente Completo con modulación por Desplazamiento de Fase (PS-FBC por sus siglas en inglés); monitoreado mediante la medición de sus estados de tensión y corriente eléctrica, y controlado por una excitación de tipo PWM provista por un DSC (Digital Signal Controller) de alto rendimiento. La topología de convertidor bajo estudio permite adaptar la tensión variable que entrega cada pila de combustible, típicamente de bajo valor, a la tensión de salida fija de un bus común de 75V conectado al SHGE. De esta manera, a lo largo del trabajo se realiza el análisis de la plataforma desarrollada a partir de la descripción de los bloques fundamentales que la conforman. Una vez realizado el estudio y diseño de la plataforma propuesta, el sistema es desarrollado mediante la herramienta EDA KiCad de generación de circuitos eléctricos y enviada para su fabricación. Finalizado el proceso de construcción del módulo propuesto, se llevaron a cabo diferentes ensayos experimentales para la validación de su correcto funcionamiento.Facultad de Ingenierí

Effect of Daily Consumption of Lactobacillus reuteri CRL 1098 on Cholesterol Reduction in Hypercholesterolemic Subjects

The effect of daily consumption of a yogurt containing Lactobacillus reuteri CRL 1098 on the lipid profile of hypercholesterolemic subjects was evaluated by performing a prospective, randomized, double-blind, cross-over placebo controlled clinical study. Participants consumed daily a yogurt containing L. reuteri CRL 1098 or a placebo for four weeks, separated by a wash-out period. Total cholesterol, triacylglycerol, high-density (HDL) and low-density (LDL) lipoprotein levels were assessed at the beginning and at the end of each period. We found a statistically significant reduction of total (−7.86 g/dl) and LDL (−7.02 g/dl) cholesterol in absolute changes (before-after) as well as a decreasing trend in the group receiving the yogurt containing L. reuteri with respect to the placebo group, without detecting changes in HDL-cholesterol and triacylglycerol levels. Our results suggest that low amounts of yogurt (125 g/day) and low doses of the CRL 1098 strain (106 CFU) are sufficient to reduce total and LDL-cholesterol levels in hypercholesterolemic subjects.Facultad de Ciencias Médica

Biological control of invasive stink bugs: review of global state and future prospects

Invasive stink bugs (Hemiptera: Pentatomidae) are responsible for high economic losses to agriculture on a global scale. The most important species, dating from recent to old invasions, include Bagrada hilaris (Burmeister), Halyomorpha halys (St\ue5l), Piezodorus guildinii (Westwood), Nezara viridula (L.), and Murgantia histrionica (Hahn). Bagrada hilaris, H. halys, and N. viridula are now almost globally distributed. Biological control of these pests faces a complex set of challenges that must be addressed to maintain pest populations below the economic injury level. Several case studies of classical and conservation biological control of invasive stink bugs are reported here. The most common parasitoids in their geographical area of origin are egg parasitoids (Hymenoptera: Scelionidae, Encyrtidae, and Eupelmidae). Additionally, native parasitoids of adult stink bugs (Diptera: Tachinidae) have in some cases adapted to the novel hosts in the invaded area and native predators are known to prey on the various instars. Improving the efficacy of biocontrol agents is possible through conservation biological control techniques and exploitation of their chemical ecology. Moreover, integration of biological control with other techniques, such as behavioural manipulation of adult stink bugs and plant resistance, may be a sustainable pest control method within organic farming and integrated pest management programs. However, additional field studies are needed to verify the efficacy of these novel methods and transfer them from research to application