Synthesis of Spherical 4R Mechanism for Path Generation using Differential Evolution

The problem of path generation for the spherical 4R mechanism is solved using the Differential Evolution algorithm (DE). Formulas for the spherical geodesics are employed in order to obtain the parametric equation for the generated trajectory. Direct optimization of the objective function gives the solution to the path generation task without prescribed timing. Therefore, there is no need to separate this task into two stages to make the optimization. Moreover, the order defect problem can be solved without difficulty by means of manipulations of the individuals in the DE algorithm. Two examples of optimum synthesis showing the simplicity and effectiveness of this approach are included.Comment: Submitted to Mechanism and Machine Theor

Aplicación de un programa de aquaeróbic de muy corta duración (4 semanas) para la mejora de la condición física saludable en mujeres jóvenes sanas

El objetivo de este estudio fue conocer la influencia sobre la condición física saludable de un programa de aquaerobic de muy corta duración en mujeres jóvenes sanas. Participaron en este trabajo 22 mujeres sin patologías aparentes (20,560,98 años), estudiantes de la licenciatura de Ciencias de la Actividad Física y el Deporte, que no practicaban ningún deporte. Los sujetos llevaron a cabo un programa de acondicionamiento físico en el medio acuático basado en el aquaerobic de muy corta duración (8 sesiones de 30 minutos). Se valoró la condición física saludable, inmediatamente antes y después de la actividad. Los resultados muestran una disminución del peso graso estimado y una mejora de la flexibilidad de tronco, fuerza de prensión manual, fuerza-resistencia abdominal, equilibrio y potencia aeróbica máxima estimada. Las conclusiones del presente trabajo fueron: a) un programa de acondicionamiento físico de muy corta duración en el medio acuático se muestra eficaz en la reducción de la masa grasa corporal y b) mediante dicho programa se consiguen mejoras en la mayoría de los parámetros de la condición física saludable en mujeres jóvenes sanas, en especial en los relacionados con la fuerza, la flexibilidad y el equilibrio

Trends in Tissue Regeneration: Bio-Nanomaterials

Tissue engineering requires functional platforms or scaffolds with specific properties concerning the morphology, chemistry of the surface and interconnectivity to promote cell adhesion and proliferation. These requisites are not only important for cellular migration but also to supply nutrients and expulsion of waste molecules. Cell type must be considered when designing a specific cellular grown system as a scaffold; for instance, if they are autologous, allogeneic or xenogeneic. The challenge in tissue engineering is to develop an organized three-dimensional architecture with functional characteristics that mimic the extracellular matrix. In this regard, with the advent of nanotechnology scaffolds are now being developed that meet most of the aforementioned requisites. In the present chapter, the use of biopolymers based nanostructures is addressed, including biomaterials and stem cells, bio-nanocomposites, and specific clinical cases where these systems were employed. We emphasize the future challenges and perspectives in the design of biocompatible and nontoxic nanocomposites with high efficiency as a promoter for tissue regeneration and many other biomedical applications

Multimodal sensory reliance in the nocturnal homing of the amblypygid \u3ci\u3ePhrynus pseudoparvulus\u3c/i\u3e (Class Arachnida, Order Amblypygi)?

Like many other nocturnal arthropods, the amblypygid Phrynus pseudoparvulus is capable of homing. The environment through which these predators navigate is a dense and heterogeneous tropical forest understory and the mechanism(s) underlying their putatively complex navigational abilities are presently unknown. This study explores the sensory inputs that might facilitate nocturnal navigation in the amblypygid P. pseudoparvulus. Specifically, we use sensory system manipulations in conjunction with field displacements to examine the potential involvement of multimodal—olfactory and visual—stimuli in P. pseudoparvulus’ homing behavior. In a first experiment, we deprived individuals of their olfactory capacity and displaced them to the opposite side of their home trees (\u3c5 m). We found that olfaction-intact individuals were more likely to be re-sighted in their home refuges than olfaction-deprived individuals. In a second experiment, we independently manipulated both olfactory and visual sensory capacities in conjunction with longer-distance displacements (8 m) from home trees. We found that sensory-intact individuals tended to be re-sighted on their home tree more often than sensory-deprived individuals, with a stronger effect of olfactory deprivation than visual deprivation. Comparing across sensory modality manipulations, olfaction-manipulated individuals took longer to return to their home trees than vision-manipulated individuals. Together, our results indicate that olfaction is important in the nocturnal navigation of P. pseudoparvulus and suggest that vision may also play a more minor role

Acoustically penetrable sonic crystals based on fluid-like scatterers

We propose a periodic structure that behaves as a fluid fluid composite for sound waves, where the building blocks are clusters of rigid scatterers. Such building-blocks are penetrable for acoustic waves, and their properties can be tuned by selecting the filling fraction. The equivalence with a fluid fluid system of such a doubly periodic composite is tested analytical and experimentally. Because of the fluid-like character of the scatterers, sound structure interaction is negligible, and the propagation can be described by scalar models, analogous to those used in electromagnetics. As an example, the case of focusing of evanescent waves and the guided propagation of acoustic waves along an array of penetrable elements is discussed in detail. The proposed structure may be a real alternative to design a low contrast and acoustically penetrable medium where new properties as those shown in this work could be experimentally realized.We acknowledge financial support by Spanish Ministerio de Economia y Competitividad and European Union FEDER through project FIS2011-29731-C02-01 and -02. VRG is grateful for the financial support of the post-doctoral grant from the "Pays de la Loire". ACR is grateful for the support of the Programa de Ayudas e Iniciativas de Investigacin (PAID) of the UPV.Cebrecos Ruiz, A.; Romero García, V.; Picó Vila, R.; Sánchez Morcillo, VJ.; Botey, M.; Herrero, R.; Cheng, YC.... (2015). Acoustically penetrable sonic crystals based on fluid-like scatterers. Journal of Physics D-Applied Physics. 48(2):25501-25510. https://doi.org/10.1088/0022-3727/48/2/025501S255012551048

Estimación de la madurez ósea en canales de bovino por fluorescencia diferencial

At present, carcass grading is dependent to a great degree on age of the animal. However, in México standards are vague on this matter, because the only requirement is stating if the animal is younger or older than 30 mo. This vagueness is the source of a need of developing objective systems for determining physiological maturity. Therefore, the purpose of the present study was estimating with great accuracy ossification of the cartilage in the 12th rib, as an indicator of bone ossification in bovine carcasses, by means of an electronic pattern obtained through artificial vision. In the model developed to this end, better use of fluorescence generated by the cartilage is made, in comparison to both bone and fat, and as a result the cartilage area stands out clearly, and by developing image processing algorithms for analyzing it, ossification percentage can be estimated with accuracy, and consequently, carcass physiological age. The artificial vision system developed in the present study allows evaluating bone maturity in a carcass in less than one second and data obtained is used for establishing carcass electronic grading in less than five seconds.Actualmente, el análisis de clasificación de calidad de la canal depende en gran medida de la edad del animal, sin embargo, el patrón en México es demasiado impreciso, pues sólo requiere identificar si éste es menor o mayor a 30 meses. Esta falta de precisión genera la necesidad de sistemas objetivos para medir la madurez fisiológica. El propósito de esta investigación fue estimar de manera precisa el porcentaje de osificación del cartílago en la 12ava costilla, como un indicador de madurez ósea en canales de bovino, utilizando un esquema electrónico por visión artificial. En el esquema desarrollado se aprovecha la mayor fluorescencia que genera el cartílago, en comparación con la del hueso y la grasa, sobresaliendo claramente la región del cartílago, desarrollando algoritmos de procesamiento de imágenes para analizar esta región, y estimar de manera precisa el porcentaje de osificación, y por tanto la edad fisiológica de la canal. El sistema de visión artificial desarrollado permitió evaluar la madurez ósea de una canal en menos de un segundo, y la información obtenida fue utilizada para establecer la clasificación electrónica de la canal en menos de cinco segundos