Planeación de trayectorias en vuelo de un manipulador industrial para el Laboratorio Fábrica Experimental UN

El presente trabajo de investigación se enfoca en la planeación de trayectorias para un sistema robótico industrial de ocho articulaciones utilizando la plataforma ROS para el desarrollo de un modelo virtual que permita comandar movimientos hacia el robot y sus ejes externos. Este sistema incluye una configuración única que no ha sido explorada previamente a través de herramientas de software similares. Para la validación del modelo virtual y de comunicación desarrollado se plantea la exploración experimental del sistema en aplicaciones de manufactura y de interacción básica con robots móviles. En el primer caso se aborda la generación de trayectorias utilizando 7 y 8 DOF para el mecanizado de superficies con forma libre o definición paramétrica. Las pruebas correspondientes se realizan sobre materiales blandos, adaptando una herramienta motorizada al manipulador industrial Motoman MH6 y usando una fresa cilíndrica de punta plana. Durante la trayectoria se lleva a cabo la interpolación de todos los ejes involucrados para alcanzar una orientación normal de la herramienta con respecto a cada punto de la superficie, proporcionando resultados satisfactorios en la calidad de la pieza. Igualmente se efectúan mediciones de velocidad y torque a los que se encuentran sometidos cada articulación, así como mediciones de precisión en el mecanizado de probetas fabricadas para validar las condiciones operativas del proceso. Por otra parte, en las pruebas básicas de interacción con un robot móvil (AGV) que se desplaza de manera autónoma de acuerdo a su algoritmo de navegación, se realiza una planeación continua de la trayectoria para mover el robot industrial hacia un objetivo dinámico correspondiente a la posición del AGV en cada instante. Esta situación evidencia un efecto de seguimiento en los robots definiendo una distancia de separación entre ellos.Abstract: This research focuses on path planning for an industrial robotic system with eight joints using ROS in order to develop a virtual model to command the robot and its external axes movements. This system has a particular setup which has not been explored with similar software tools. For virtual and communication models validation it is proposed an experimental exploration of the system in manufacturing applications and basic interaction with mobile robots. In the first case, the trajectories generation with 7 and 8 DOF is approached for machining of free- shaped or parametric surfaces. The corresponding tests are performed on soft materials, with adapting a mototool to Motoman MH6 industrial manipulator and using a flat-cylindrical milling tool. All joints interpolate along the trajectory to achieve normal tool orientation for every point in the surface. It provides suitable results for part quality. Further, speed and torque measurements for each joint are registered, as well as machining precision measure- ments over test pieces to verify operating conditions in the process. Additionally, in the basic tests for interaction with a mobile robot (AGV) which moves autonomously according with its navigation algorithm a path is planned to move the industrial robot toward a dynamic target defined by the AGV’s instant position. This situation shows a tracking effect among the robots with a fixed distance between them.Maestrí

Lactoferrin in the Battle against Intestinal Parasites: A Review

Lactoferrin is an iron-binding glycoprotein of the innate immune system, which is present in some mammalian fluids and secreted into the mucosae; it is also produced by the secondary granules of the polymorphonuclear neutrophils and secreted at infection sites. Lactoferricins (Lfcins) are peptides derived from the N-terminus of Lf. Lf avoids the iron availability to parasites in the body fluids due to its high avidity for iron, maintaining together with transferrin the free-iron concentration in about 10−18 M, which is too low to support the pathogenic invader survival. Intestinal parasitic diseases affect people worldwide, mainly in developing countries with poor hygienic conditions; for example, parasites such as Entamoeba histolytica, Giardia intestinalis, and Cryptosporidium parvum infect the human intestine when are orally ingested as cysts. Human and bovine Lf have been found parasiticidal in experiments in vitro and in animal models. Interestingly, Lf synergizes with metronidazole, the main drug used against E. histolytica and G. intestinalis. The aim of this chapter is to show the benefits of using Lf and Lfcins against intestinal parasitic diseases

A New Parasiticidal Compound inT. soliumCysticercosis

The effect of 16α-bromoepiandrosterone (EpiBr), a dehydroepiandrosterone (DHEA) analogue, was tested on the cysticerci of Taenia solium, both in vitro and in vivo. In vitro treatment of T. solium cultures with EpiBr reduced scolex evagination, growth, motility, and viability in dose- and time-dependent fashions. Administration of EpiBr prior to infection with T. solium cysticerci in hamsters reduced the number and size of developed taenias in the intestine, compared with controls. These effects were associated to an increase in splenocyte proliferation in infected hamsters. These results leave open the possibility of assessing the potential of this hormonal analogue as a possible antiparasite drug, particularly in cysticercosis and taeniosis

Indicadores del impacto del cambio climático en la agricultura familiar andina colombiana

Los modelos de evaluación de los impactos del cambio climático utilizados en la agricultura colombiana  se han enfocado en cultivos tecnificados, sembrados en grandes superficies, obviando que el 67% de la producción nacional de alimentos provienen de pequeñas extensiones de policultivos cultivados, en su mayor parte, en suelos de ladera de la cordillera andina, por 3,5 millones de agricultores y que aportan el 57% del empleo rural. El presente artículo se deriva de un análisis de la metodología empleada por los autores en el proyecto de investigación denominado “Impactos económicos, ambientales y sociales del cambio climático en el sector agropecuario del Municipio Bochalema, Departamento Norte de Santander, Colombia, financiado por la Universidad de Santander (UDES) y que abarca el período comprendido entre enero de 2017 y mayo de 2018. Después de analizar diferentes modelos de evaluación de impactos ambientales se seleccionó el modelo de Presión, Estado, Respuesta (PER) de la OCDE, previa adaptación a las características específicas de pequeñas unidades de producción agrícola de subsistencia. Se evidenció la multidimensionalidad y complejidad de los factores relacionados con el clima, la producción, los recursos, las tecnologías, las familias y las políticas públicas, que obligan a la construcción de indicadores contextualizados a la agricultura familiar andina

Indicadores del impacto del cambio climático en la agricultura familiar andina colombiana

Los modelos de evaluación de los impactos del cambio climático utilizados en la agricultura colombiana se han enfocado en cultivos tecnificados, sembrados en grandes superficies, obviando que el 67% de la producción nacional de alimentos provienen de pequeñas extensiones de policultivos cultivados, en su mayor parte, en suelos de ladera de la cordillera andina, por 3,5 millones de agricultores y que aportan el 57% del empleo rural. El presente artículo se deriva de un análisis de la metodología empleada por los autores en el proyecto de investigación denominado “Impactos económicos, ambientales y sociales del cambio climático en el sector agropecuario del Municipio Bochalema, Departamento Norte de Santander, Colombia, financiado por la Universidad de Santander (UDES) y que abarca el período comprendido entre enero de 2017 y mayo de 2018. Después de analizar diferentes modelos de evaluación de impactos ambientales se seleccionó el modelo de Presión, Estado, Respuesta (PER) de la OCDE, previa adaptación a las características específicas de pequeñas unidades de producción agrícola de subsistencia. Se evidenció la multidimensionalidad y complejidad de los factores relacionados con el clima, la producción, los recursos, las tecnologías, las familias y las políticas públicas, que obligan a la construcción de indicadores contextualizados a la agricultura familiar andina

Field study of parasitic contamination of fruits, vegetables and leafy greens in the Ecuadorian Andes [version 1; peer review: 2 approved, 1 approved with reservations]

Background: Raw vegetables have been considered vehicles of enteroparasites. South American countries are among the most important exporters of fresh vegetables; Ecuador has tropical climates and soils rich in organic matter that allow it to harvest throughout the year for sale to different countries. The aim of the study was to assess the occurrence of the parasitic contamination of fruits, vegetables and leafy greens grown in an agricultural area of the Ecuadorian Andes. Methods: A field study, cross-sectional, snowball sampling was conducted on 1,416 samples (516 fruits, 488 vegetables, and 412 leafy greens). Each sample were washed with water, and the resulting solution after removing the vegetables, was subjected to 24-hour sedimentation. The concentrated sediment underwent microscopic analysis. Results: Parasites were detected in 63.4% of the samples, leafy greens were the most contaminated (76.9%) (P<0.0001), (vegetables 67.8% and fruit 48.4%), of these, cabbage (100%), onions (84%) and strawberries (60.2%) were the most contaminated. Protozoa were more frequent (49.6%) than helminths (15.5%) (P<0.0001). Blastocystis sp. (33.5%) was the highest, followed by Eimeria spp. (26.3%), Entamoeba spp. (10.3%), Giardia spp. (8.3%), Balantidium spp. (6.9%); Cryptosporidium spp. (6.6%), Cyclospora spp. (4.4%), Cystoisospora spp. (0.5%); Strongylida (15.5%) and Ascaris spp. (0.4%). Conclusion: The consumption of fruits, vegetables, and leafy greens from these crops is a possible source of infection to humans and animals in this area or in nonendemic areas where these products are marketed. This study establishes the need for strict hygienic measures in growing; this will be properly achieved by the treatment of the soil, manure and water used for cultivation

Regulation of Intestinal Immune Response by Selective Removal of the Anterior, Posterior, or Entire Pituitary Gland in Trichinella spiralis Infected Golden Hamsters

The influence of anterior pituitary hormones on the gastrointestinal tract of humans and animals has been previously reported. Hypophysectomy (HYPOX) in the rat causes atrophy of the intestinal mucosa, and reduction of gastric secretion and intestinal absorption, as well as increased susceptibility to bacterial and viral infections. However, to our knowledge, no findings have been published concerning the immune response following HYPOX during worm infection, particularly that which is caused by the nematode Trichinella spiralis. The aim of this work was to analyze the effects of total or partial HYPOX on colonization of T. spiralis in the intestinal lumen, together with duodenal and splenic cytokine expression. Our results indicate that 5 days post infection, only neurointermediate pituitary lobectomy (NIL) reduces the number of intestinally recovered T. spiralis larvae. Using semiquantitative inmunofluorescent laser confocal microscopy, we observed that the mean intensity of all tested Th1 cytokines was markedly diminished, even in the duodenum of infected controls. In contrast, a high level of expression of these cytokines was noted in the NIL infected hamsters. Likewise, a significant decrease in the fluorescence intensity of Th2 cytokines (with the exception of IL-4) was apparent in the duodenum of control and sham infected hamsters, compared to animals with NIL surgeries, which showed an increase in the expression of IL-5 and IL-13. Histology of duodenal mucosa from NIL hamsters showed an exacerbated inflammatory infiltrate located along the lamina propria, which was related to the presence of the parasite. We conclude that hormones from each pituitary lobe affect the gastrointestinal immune responses to T. spiralis through various mechanisms

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R$^{2}$ = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R$^{2}$ = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

AimAmazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous tree lineages, including some ancient ones (&gt;66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions