Virtual Model Control of a Biped Walking Robot

The transformation from high level task specification to low level motion control is a fundamental issue in sensorimotor control in animals and robots. This thesis develops a control scheme called virtual model control which addresses this issue. Virtual model control is a motion control language which uses simulations of imagined mechanical components to create forces, which are applied through joint torques, thereby creating the illusion that the components are connected to the robot. Due to the intuitive nature of this technique, designing a virtual model controller requires the same skills as designing the mechanism itself. A high level control system can be cascaded with the low level virtual model controller to modulate the parameters of the virtual mechanisms. Discrete commands from the high level controller would then result in fluid motion. An extension of Gardner's Partitioned Actuator Set Control method is developed. This method allows for the specification of constraints on the generalized forces which each serial path of a parallel mechanism can apply. Virtual model control has been applied to a bipedal walking robot. A simple algorithm utilizing a simple set of virtual components has successfully compelled the robot to walk eight consecutive steps.

Dosis de carga de la desfibrilación en el manejo del paro cardiorrespiratorio del paciente pediátrico. Revisión sistemática de la literatura

Antecedentes El paro cardiarrespiratorio en el paciente pediátrico incluye, entre otros procedimientos, la aplicación de la desfibrilación. Sin embargo se desconoce la dosis óptima para realizarla. Objetivo Evaluar la evidencia disponible sobre las dosis de desfibrilación que deben ser empleadas en el paciente pediátrico durante la reanimación cerebro cardiopulmonar. Metodología Se realizó una revisión sistemática de la literatura con búsqueda a través de las bases de datos PUBMED, OVID, EMBASE y LILACS y el registro de ensayos clínicos de los Estados Unidos de cualquier tipo de diseño metodológico en animales o humanos que explorará las dosis de carga que deben emplearse en la desfibrilación. Se realizó un análisis cualitativo de la información y se extrajeron las medidas de resumen. Resultados Se encontraron tres estudios de cohortes y un modelo en animales que reportan resultados contradictorios. Con base en la evidencia disponible puede afirmarse que la dosis de carga inicial de 2 J/Kg utilizada en la actualidad reporta menores proporciones de eficacia que las históricas. Por otra parte no existe evidencia disponible que permita dar comprender cual es la dosis de carga óptima que deba utilizarse. Conclusión No existe evidencia sobre la dosis de carga óptima que deba ser utilizada en la desfibrilación del paciente pediátrico. Deben diseñarse y realizarse estudios observacionales y ensayos clínicos que permitan dar respuesta a esta pregunta. Palabras claves (MeSH): Desfibrilación, paro cardiaco, reanimación cardiopulmonar, revisión sistemática como tópico.

Potencialidades terapéuticas del juego de rol

Esta investigación cualitativa-cuantitativa tiene como objetivo explorar las potencialidades terapéuticas del Juego de Rol, las cuales no han sido objeto de estudio. Se realizó con cinco estudiantes de colegio y cuatro de universidad, aplicándoles las escalas 16PF, SASS, ocho sesiones de juego de rol (Dungeons and dragons) y Grupos de Discusión. Se concluyó que no hay diferencia entre la adaptación pre y post. Los estudiantes de Colegio tienen características de personalidad similares en escala de Autosuficiencia, Apertura al Cambio y Aprensión, los universitarios en Atrevimiento, Vigilancia, Abstracción y Aprensión y dimensión global de Ansiedad. El Juego de Rol mejora las relaciones interpersonales dentro y fuera del grupo de juego, la expresión de sentimientos repercute fuera del Juego, la principal diferencia entre la experiencia de juego y la Vida Real es la libertad para romper las normas sociales. El trabajo en Equipo es una enseñanza primordial, contribuye a la toma de decisiones, proyección como mecanismo de defensa, capacidad Imaginativa inherente, desarrollo de la empatía, socialización, potenciación de habilidades no explotadas, encuentro de intereses, toma de conciencia, responsabilidad y sublimación de aspectos reprimidos de la personalidad.

Plan de empresa PS Smoothies

PS Smoothies es una empresa de sociedad anónima simplificada que se dedicará a la comercialización y producción de bebidas, específicamente batidos a base de frutas naturales, comenzando a realizar sus actividades en Junio 2015. Estos batidos se entregarán en un punto de venta semi-estacionario que se ubicará de la carrera 5 a la 11, y de la calle 18 a la 101 de la ciudad de Bogotá. La ambientación del lugar estará basada en el concepto de la fauna y flora colombiana. Para iniciar la empresa se requiere de una inversión inicial por valor de $ 29’535.790 millones de pesos, la cual se recupera al tercer año de actividad. El portafolio de productos manejará solo la línea de Smoothies, los cuales serán elaborados con materias primas e insumos de excelente calidad, naturales y nutritivos, que aportan al consumidor vitaminas esenciales para mantener una buena salud. Al cabo de cumplir el primer año de operación la empresa alcanzará su punto de equilibrio, el cual se fijó en $132’601.368 millones de pesos al año. En el primer año de operación se obtiene utilidad por $7’312.780 millones de pesos y una tasa interna de retorno (TIR) del 20,65% EA. Para el tercer año se espera un crecimiento en ventas respecto al segundo año de un 7,35% y una utilidad de 19’928.523 millones de pesos.

La cooperación internacional como instrumento para la construcción de paz en Colombia. Estudio de caso del proyecto “Fortalecimiento institucional para la atención a las víctimas del conflicto (FORVIC)” (2009-2014)

El presente estudio de caso pretende analizar los alcances de la cooperación internacional en materia de justicia transicional y construcción de paz tomando en consideración un proyecto de cooperación internacional emblemático denominado Fortalecimiento Institucional para la Atención a las Víctimas del Conflicto o FORVIC. Para conseguir esto, se analizarán primero los efectos generados por el Proyecto FORVIC en materia de fortalecimiento del Estado de Derecho y lucha contra la impunidad en Colombia, y a partir de los hallazgos se constituirán y se propondrán una serie de condiciones sobre las que puede pensarse la cooperación internacional como un instrumento genuino para la construcción de paz en Colombia.

Estudo de incidência de hipertiroidismo felino

O Hipertiroidismo Felino é uma endocrinopatia emergente em felinos geriátricos nos últimos 20 anos. É caracterizada pela elevada produção de hormonas tiróideias, originando sinais clínicos multisistémicos por vezes inespecíficos, tornando o seu diagnóstico um desafio. O diagnóstico é estabelecido maioritariamente com base no aumento da concentração sérica de tiroxina (T4) total e no quadro clínico. O tratamento pode ser realizado através de três modalidades distintas, o maneio médico, a tiroidectomia e a radioterapia. A sua etiologia permanece desconhecida, sendo considerada actualmente uma doença multifactorial, com elevada incidência e prevalência em diversos Países, como EUA, Reino Unido e Alemanha. A sua incidência em Portugal é desconhecida. Actualmente os factores de risco mais preponderantes são a idade geriátrica, e o contacto com químicos goitrogénicos presentes no alimento ou no ambiente. A raça europeu comum apresenta maior predisposição para o desenvolvimento da doença, as raças Himalaia e Siâmes apresentam menor risco. O presente estudo foi realizado com os objectivos de determinar a incidência de hipertiroidismo felino na região de Aveiro entre Outubro de 2010 e Janeiro de 2012 e os seus potenciais factores de risco. A incidência de hipertiroidismo em animais com idade ≥ 8 anos foi 7,69% e 9,84% em animais com idade ≥ 10 anos. Gatos mais geriátricos, assim como animais do sexo masculino apresentam maior predisposição ao desenvolvimento da doença.

Estudo restrospectivo de pancreatite canina em 41 casos

A pancreatite, apesar de relativamente comum na medicina canina, continua a constituir um desafio devido à sua elevada complexidade patogénica, sinais clínicos não patognomónicos, diagnóstico por vezes difícil e tratamento inespecífico. De forma a realizar um estudo retrospectivo foram avaliados registos médicos de 41 canídeos diagnosticados com pancreatite, apresentados à consulta entre 2007 e 2013, de forma a caracterizar o doente pancreático. As características do animal, história clinica, sinais clínicos apresentados, métodos de diagnóstico e tratamento instituído foram analisados. Como critérios de inclusão neste estudo encontram-se a medição de cPLI com resultados acima do valor de referência e a realização de ecografia abdominal. A ecografia demonstrou evidências de pancreatite em 81% dos casos, sendo este valor superior aos 68% encontrados na literatura. Os sinais clínicos apresentados mais comuns foram vómito (39), prostração (38), dor abdominal (36), perda de peso e anorexia (26), desidratação (25), diarreia (21) e febre (5). Todos os animais foram submetidos a tratamento médico, tendo sido apenas 4 deles sujeitos também a cirurgia. A taxa de sobrevivência nos animais com tratamento médico foi de 95% e de 50 % nos animais com tratamento médico e cirúrgico.

Cue combination for 3D location judgements

Cue combination rules have often been applied to the perception of surface shape but not to judgements of object location. Here, we used immersive virtual reality to explore the relationship between different cues to distance. Participants viewed a virtual scene and judged the change in distance of an object presented in two intervals, where the scene changed in size between intervals (by a factor of between 0.25 and 4). We measured thresholds for detecting a change in object distance when there were only 'physical' (stereo and motion parallax) or 'texture-based' cues (independent of the scale of the scene) and used these to predict biases in a distance matching task. Under a range of conditions, in which the viewing distance and position of the tarte relative to other objects was varied, the ration of 'physical' to 'texture-based' thresholds was a good predictor of biases in the distance matching task. The cue combination approach, which successfully accounts for our data, relies on quite different principles from those underlying geometric reconstruction.

Organizational effects of fetal testosterone on human corpus callosum size and asymmetry

Previous theory and research in animals has identified the critical role that fetal testosterone (FT) plays in organizing sexually dimorphic brain development. However, to date there are no studies in humans directly testing the organizational effects of FT on structural brain development. In the current study we investigated the effects of FT on corpus callosum size and asymmetry. High-resolution structural magnetic resonance images (MRI) of the brain were obtained on 28 8-11-year-old boys whose exposure to FT had been previously measured in utero via amniocentesis conducted during the second trimester. Although there was no relationship between FT and midsaggital corpus callosum size, increasing FT was significantly related to increasing rightward asymmetry (e.g., Right>Left) of a posterior subsection of the callosum, the isthmus, that projects mainly to parietal and superior temporal areas. This potential organizational effect of FT on rightward callosal asymmetry may be working through enhancing the neuroprotective effects of FT and result in an asymmetric distribution of callosal axons. We suggest that this possible organizational effect of FT on callosal asymmetry may also play a role in shaping sexual dimorphism in functional and structural brain development, cognition, and behavior.

Genesis and expansion of metazoan transcription factor gene classes

We know little about the genomic events that led to the advent of a multicellular grade of organization in animals, one of the most dramatic transitions in evolution. Metazoan multicellularity is correlated with the evolution of embryogenesis, which presumably was underpinned by a gene regulatory network reliant on the differential activation of signaling pathways and transcription factors. Many transcription factor genes that play critical roles in bilaterian development largely appear to have evolved before the divergence of cnidarian and bilaterian lineages. In contrast, sponges seem to have a more limited suite of transcription factors, suggesting that the developmental regulatory gene repertoire changed markedly during early metazoan evolution. Using whole- genome information from the sponge Amphimedon queenslandica, a range of eumetazoans, and the choanoflagellate Monosiga brevicollis, we investigate the genesis and expansion of homeobox, Sox, T- box, and Fox transcription factor genes. Comparative analyses reveal that novel transcription factor domains ( such as Paired, POU, and T- box) arose very early in metazoan evolution, prior to the separation of extant metazoan phyla but after the divergence of choanoflagellate and metazoan lineages. Phylogenetic analyses indicate that transcription factor classes then gradually expanded at the base of Metazoa before the bilaterian radiation, with each class following a different evolutionary trajectory. Based on the limited number of transcription factors in the Amphimedon genome, we infer that the genome of the metazoan last common ancestor included fewer gene members in each class than are present in extant eumetazoans. Transcription factor orthologues present in sponge, cnidarian, and bilaterian genomes may represent part of the core metazoan regulatory network underlying the origin of animal development and multicellularity.

The potential for genetic adaptations to language

We suggest there is somewhat more potential than Christiansen & Chater (C&C) allow for genetic adaptations specific to language. Our uniquely cooperative social system requires sophisticated language skills. Learning and performance of some culturally transmitted elements in animals is genetically based, and we give examples of features of human language that evolve slowly enough that genetic adaptations to them may arise.

Large punctuational contribution of speciation to evolutionary divergence at the molecular level

A long-standing debate in evolutionary biology concerns whether species diverge gradually through time or by punctuational episodes at the time of speciation. We found that approximately 22% of substitutional changes at the DNA level can be attributed to punctuational evolution, and the remainder accumulates from background gradual divergence. Punctuational effects occur at more than twice the rate in plants and fungi than in animals, but the proportion of total divergence attributable to punctuational change does not vary among these groups. Punctuational changes cause departures from a clock-like tempo of evolution, suggesting that they should be accounted for in deriving dates from phylogenies. Punctuational episodes of evolution may play a larger role in promoting evolutionary divergence than has previously been appreciated.

Bioactive peptides from food proteins: new opportunities and challenges

Food proteins such as milk and soy are a rich source of bioactive peptides. In the last decade, research into this area has intensified and new bioactive peptide sequences have been discovered with a range of apparent biological functions; for example, antihypertensive, antioxidant, and antimicrobial effects and opiate-like qualities have been reported. These peptides could therefore lead to the development of important functional food products and ingredients for the prevention and even treatment of chronic diseases such as cardiovascular disease and cancer. Peptides can be produced by fermentation with dairy starters for instance, and by enzymatic hydrolysis with pancreatic and microbial enzymes. Further purification is typically carried out by membrane filtration and/or chromatographic methods. The production of novel bioactive peptides and their incorporation into functional food products poses several technological challenges as well as regulatory and marketing issues. Proof of efficacy is of paramount importance; this should be verified by conducting appropriate tests in vivo in animals and in humans. In addition, tests for cytotoxicity and allergenicity must be conducted. Despite all of these hurdles, scientific evidence is increasingly demonstrating the health benefits of diet-based disease prevention, and therefore new developments in this area are likely to continue both at the research and the commercialisation level.

Rat neurosphere cells protect axotomized rat retinal ganglion cells and facilitate their regeneration

We investigated the ability of a population of rat neural stem and precursor cells derived from rat embryonic spinal cord to protect injured neurons in the rat central nervous system (CNS). The neonatal rat optic pathway was used as a model of CNS injury, whereby retinal ganglion cells (RGCs) were axotomized by lesion of the lateral geniculate nucleus one day after birth. Neural stem and precursor cells derived from expanded neurospheres (NS) were transplanted into the lesion site at the time of injury. Application of Fast Blue tracer dye to the lesion site demonstrated that significant numbers of RGCs survived at 4 and 8 weeks in animals that received a transplant, with an average of 28% survival, though in some individual cases survival was greater than 50%. No RGCs survived in animals that received a lesion alone. Furthermore, labeled RGCs were also observed when Fast Blue was applied to the superior colliculus (SC) at 4 weeks, suggesting that neurosphere cells also facilitated RGC to regenerate to their normal target. Transplanted cells did not migrate or express neural markers after transplantation, and secreted several neurotrophic factors in vitro. We conclude that NS cells can protect injured CNS neurons and promote their regeneration. These effects are not attributable to cell replacement, and may be mediated via secretion of neurotrophic factors. Thus, neuroprotection by stem cell populations may be a more viable approach for treatment of CNS disorders than cell replacement therapy.

Inulin and oligofructose: effects on lipid metabolism from human studies

Although convincing lipid-lowering effects of the fructo-oligosaccharide, inulin, have been demonstrated in animals, attempts to reproduce similar effects in man have produced conflicting findings. This may be because of the much lower doses which can be used due to the adverse gastrointestinal symptoms exhibited by most subjects consuming in excess of 15 g/d. There are nine studies reported in the literature which have investigated the response of blood lipids (usually total and LDL-cholesterol and triacylglycerol) to inulin or oligofructose supplementation in human volunteers. Three have observed no effects of inulin or oligofructose on blood levels of cholesterol or triacylglycerol, three have shown significant reductions in triacylglycerol, whilst four have shown modest reductions in total and LDL-cholesterol. Studies have been conducted in both normo- and moderately hyperlipidaemic subjects. Differences in study outcomes do not appear to be due to differences in the type or dose of oligosaccharides used nor the duration of the studies. Because animal studies have identified inhibition of hepatic fatty acid synthesis as the major site of action for the triacylglycerol lowering effects of inulin and oligofructose, and because this pathway is relatively inactive in man unless a high carbohydrate diet is fed, variability in response may be a reflection of differences in background diet or the experimental foods used.