Evaluating alternative gait strategies using evolutionary robotics

Evolutionary robitics is a branch of artificial intelligence concerned with the automatic generation of autonomous robots. Usually the form of the robit is predefined an various computational techniques are used to control the machine's behaviour. One aspect is the spontaneous generation of walking in legged robots and this can be used to investigate the mechanical requiements for efficient walking in bipeds. This paper demonstrates a bipedal simulator that spontaneously generates walking and running gaits. The model can be customized to represent a range of hominoid morphologies and used to predict performance paramets such as preferred speed and metabolic energy cost. Because it does not require any motion capture data it is particularly suitable for investigating locomotion in fossil animals. The predictoins for modern humans are highly accurate in terms of energy cost for a given speend and thus the values predicted for other bipeds are likely to be good estimates. To illustrate this the cost of transport is calculated for Australopithecus afarensis. The model allows the degree of maximum extension at the knee to be varied causing the model to adopt walking gaits varying from chimpanzee-like to human=like. The energy costs associated with these gait choices can thus be calculated and this information used to evaluate possible locomotor strategies in early hominids

Predicting the metabolic energy costs of bipedalism using evolutionary robotics

To understand the evolution of bipedalism among the homnoids in an ecological context we need to be able to estimate theenerrgetic cost of locomotion in fossil forms. Ideally such an estimate would be based entirely on morphology since, except for the rare instances where footprints are preserved, this is hte only primary source of evidence available. In this paper we use evolutionary robotics techniques (genetic algoritms, pattern generators and mechanical modeling) to produce a biomimentic simulation of bipedalism based on human body dimensions. The mechnaical simulation is a seven-segment, two-dimensional model with motive force provided by tension generators representing the major muscle groups acting around the lower-limb joints. Metabolic energy costs are calculated from the muscel model, and bipedal gait is generated using a finite-state pattern generator whose parameters are produced using a genetic algorithm with locomotor economy (maximum distance for a fixed energy cost) as the fitness criterion. The model is validated by comparing the values it generates with those for modern humans. The result (maximum efficiency of 200 J m-1) is within 15% of the experimentally derived value, which is very encouraging and suggests that this is a useful analytic technique for investigating the locomotor behaviour of fossil forms. Initial work suggests that in the future this technique could be used to estimate other locomotor parameters such as top speed. In addition, the animations produced by this technique are qualitatively very convincing, which suggests that this may also be a useful technique for visualizing bipedal locomotion.

Validity and reliability of a pictorial instrument for assessing perceived motor competence in Portuguese children

It is important to assess young children's perceived Fundamental Movement Skill (FMS) competence in order to examine the role of perceived FMS competence in motivation toward physical activity. Children's perceptions of motor competence may vary according to the culture/country of origin; therefore, it is also important to measure perceptions in different cultural contexts. The purpose was to assess the face validity, internal consistency, test–retest reliability and construct validity of the 12 FMS items in the Pictorial Scale for Perceived Movement Skill Competence for Young Children (PMSC) in a Portuguese sample. Methods Two hundred one Portuguese children (girls, n = 112), 5 to 10 years of age (7.6 ± 1.4), participated. All children completed the PMSC once. Ordinal alpha assessed internal consistency. A random subsamples (n = 47) were reassessed one week later to determine test–retest reliability with Bland–Altman method. Children were asked questions after the second administration to determine face validity. Construct validity was assessed on the whole sample with a Bayesian Structural Equation Modelling (BSEM) approach. The hypothesized theoretical model used the 12 items and two hypothesized factors: object control and locomotor skills. Results The majority of children correctly identified the skills and could understand most of the pictures. Test–retest reliability analysis was good, with an agreement ration between 0.99 and 1.02. Ordinal alpha values ranged from acceptable (object control 0.73, locomotor 0.68) to good (all FMS 0.81). The hypothesized BSEM model had an adequate fit. Conclusions The PMSC can be used to investigate perceptions of children's FMS competence. This instrument can also be satisfactorily used among Portuguese children.

Investigação do efeito de analgésicos no pós-operatório de ratos WISTAR submetidos ao modelo de cirurgia esteriotáxica

A dor é um fenômeno que induz alterações fisiológicas que alteram e que podem até mesmo invalidar os resultados de um experimento. Nos protocolos de cirurgia estereotáxica (SS) em roedores não é comum a utilização de analgésicos no pósoperatório, sob o argumento de que os mesmos interferem nos resultados. Nosso objetivo foi investigar o efeito da administração de analgésicos no pós-operatório de ratos submetidos ao modelo de SS. Os parâmetros avaliados foram mudanças na ingestão de ração, no peso dos animais, possíveis alterações comportamentais e a astrogliose reativa. A cirurgia foi realizada nas coordenadas referentes ao estriado esquerdo. Foram utilizados ratos Wistar machos. O tramadol foi administrado a cada 12 h e o carprofeno a cada 24 h, ambos até os animais completarem 72 h de pós-operatório. O peso da ração mostra que todos os animais que sofreram cirurgia comeram significativamente menos do que os grupos Ctrl nos tempos 48 e 72 h após a SS. Quando o peso dos animais foi avaliado, os grupos SS+TM e SS+CP perderam significativamente mais peso do que os grupos Ctrl. Os testes comportamentais não apresentaram diferença estatística. Nosso estudo mostra que, para os parâmetros avaliados, não houve prejuízo aos animais que receberam analgesia após a cirurgia. Assim, concluímos que é possível o uso desses fármacos na rotina dos animais submetidos ao modelo de SS

Increase in Hippocampal Theta Oscillations during Spatial Decision Making

The processing of spatial and mnemonic information is believed to depend on hippocampal theta oscillations (5–12 Hz). However, in rats both the power and the frequency of the theta rhythm are modulated by locomotor activity, which is a major confounding factor when estimating its cognitive correlates. Previous studies have suggested that hippocampal theta oscillations support decision-making processes. In this study, we investigated to what extent spatial decision making modulates hippocampal theta oscillations when controlling for variations in locomotion speed. We recorded local field potentials from the CA1 region of rats while animals had to choose one arm to enter for reward (goal) in a four-arm radial maze. We observed prominent theta oscillations during the decision-making period of the task, which occurred in the center of the maze before animals deliberately ran through an arm toward goal location. In speed-controlled analyses, theta power and frequency were higher during the decision period when compared to either an intertrial delay period (also at the maze center), or to the period of running toward goal location. In addition, theta activity was higher during decision periods preceding correct choices than during decision periods preceding incorrect choices. Altogether, our data support a cognitive function for the hippocampal theta rhythm in spatial decision making

Reflexión sobre los problemas a la reincorporación laboral tras incapacidades médicas largas

Las dolencias lumbares, la patología psiquiátrica y el cáncer de mama son las tres principales causas de incapacidad médica prolongada. Las incapacidades laborales largas suponen ante todo elevados costes en "capital humano" y costes en "capital salud" del trabajador de graves consecuencias; las incapacidades médicas largas son un tema de salud pública con enormes repercusiones en el sistema económico y de prestaciones del sistema público de salud y de prestaciones de la seguridad social. Es urgente la elaboración de un Mapa de la Incapacidad en España, para conocer población de riesgo, marcadores de riesgo, factores de riesgo y evolución de las incapacidades médicas de larga duración, es decir el propio riesgo protegido. Si conocemos el impacto incapacitante de la pérdida de salud en la población trabajadora se procederá a una mejor gestión y adecuación de recursos públicos destinados a la atención, promoción, prevención, reintegración, y prestaciones en torno a la incapacidad temporal y permanente. Entre los riesgos derivados de las incapacidades médicas prolongadas se encuentran el riesgo de pérdida de trabajo, aumento del riesgo de incapacidad permanente, disminución de calidad de vida, riesgos en la salud, deterioro de la vida familiar y de relación, gastos en apoyo a su situación, gastos sanitarios no públicos y una situación de precariedad y conflicto para la vuelta al trabajo. La mejor prevención es conocer por qué enfermamos y la mejor protección social es saber en qué gastamos. Para evitar los problemas a la reincorporación laboral tras larga incapacidad es preciso conocer cuántos factores la causan, así como las circunstancias personales, laborales, sociales y demográficas que la modulan y conocer la evolución de las situaciones incapacitantes tanto temporales como permanentes, más allá del gasto, para conocer realmente el estado de la salud laboral en cada momento y poder adoptar políticas de mejora. Y es preciso adecuación de los procesos de incapacidad, facultar la reincorporación parcial, conocimiento compartido de limitaciones y evolución del proceso y capacidades que requiere el trabajo. Conclusiones: Es urgente la elaboración de un mapa de la incapacidad en España, para conocer la población de riesgo, conocer no sólo el cuánto (el coste o su número) sino las causas de las incapacidades prolongadas. Adopción de medidas para evitar o paliar los problemas al retorno laboral tras incapacidades médicas laborales largas. Dentro de las bajas de larga duración, las que ocasionan de verdad problemas a la reincorporación laboral son las que duran más de 6 meses, o se prolongan hasta el período máximo del año, o las que están en fase de prórroga o a las incapacidades permanentes revisadas. Para acortar las incapacidades largas, primero y principal, que la baja corresponda a situación indicada o adecuada, tanto en el inicio como en su final, que no se amparen situaciones de refugio protegido. Que la atención sanitaria se preste en tiempo y forma, sin listas de espera. Protocolizar unidades de atención temprana, sobre todo en patologías psíquicas o del aparato locomotor. Es imprescindible una mayor comunicación, coordinación y cooperación entre el ámbito médico sanitario (prestación y atención sanitaria), el ámbito médico evaluador (prestaciones económicas) y el ámbito médico laboral (atención, prevención y vigilancia salud laboral), creando un flujo de información entre estas tres áreas, propiciando acceso a la historia clínica y al conocimiento de las capacidades que requiere el trabajo mediante el uso de fichas de valoración ocupacional para trabajadores en incapacidad temporal. Hay que favorecer la adecuación de las situaciones de incapacidad médica larga y la adaptación en el retorno al trabajo, así como posibilitar la reintegración paulatina del trabajador" con "altas parciales" que faciliten el reingreso al trabajo y prevengan recaídas.

Le rôle des acides gras oméga-3 sur la balance énergétique, la régulation de l’appétit, l’état émotionnel et l’implication du récepteur GPR120

L’obésité est un facteur de risque lié à des problèmes physiques, émotionnels et comportementaux. Aujourd’hui, l’alimentation est composée d’un régime typiquement occidental «Western diet» qui est riche en acides gras saturés (AGS) et pauvre en acides gras polyinsaturés (AGPI) tel que les oméga-3 (N-3) et occasionnant un déséquilibre du ratio alimentaire N-6/N-3. Ce déséquilibre est une des causes de la prévalence des maladies mentales y compris celles des troubles de l'humeur et de l’anxiété. L’acide docosahexaénoïque (ADH, 22: 6 n-3) est l’acide gras (AG) le plus abondant dans le cerveau et son accumulation est particulièrement élevée pendant la période périnatale. Il joue un rôle important dans le développement neuronal et d'autres fonctions du cerveau tel l'apprentissage et la mémoire. Des perturbations de l’environnement périnatal peuvent influencer à très long terme l’avenir de la descendance en la rendant plus susceptible de développer des problèmes d’obésité dans un contexte nutritionnel riche. On ignore cependant si le déficit alimentaire chez la mère et particulièrement en ADH aura un impact sur la motivation alimentaire de la progéniture. L’objectif principal de cette thèse est d’étudier le rôle potentiel des N-3 sur la balance énergétique, la motivation alimentaire, la dépression et le niveau d’anxiété des descendants de souris mâles adultes assujetties à une alimentation riche en gras. Nos données ont démontré qu‘un régime maternel déficitaire en ADH durant la période périnatale incitait la descendance à fournir plus d’effort afin d’obtenir un aliment palatable. Ceci entraînerait un dérèglement de l’homéostasie énergétique en augmentant le gain de poids et en diminuant l’activité locomotrice tout en exacerbant le comportement de type anxieux dès que les souris sont exposées à un milieu obésogène. Les acides gras libres (AGL) sont des nutriments essentiels fonctionnant comme des molécules de signalisation dans le cerveau en ayant des récepteurs qui jouent un rôle important dans le contrôle du métabolisme énergétique. Parmi eux, on distingue un récepteur couplé à la protéine G (GPCR), le GPR120. Ce récepteur activé par les AGPI ω-3 intervient dans les mécanismes anti-inflammatoires et insulino-résistants via les N-3. Une mutation dans le gène GPR120 occasionnée par une réduction de l’activité de signalisation du gène est liée à l’obésité humaine. L'objectif premier de cette deuxième étude était d’évaluer l'impact de la stimulation pharmacologique de GPR120 dans le système nerveux central (SNC) sur l'alimentation, les dépenses d'énergie, le comportement de type anxieux et la récompense alimentaire. Nos résultats démontrent qu’une injection centrale aiguë d'agoniste GPR120 III réduit la prise alimentaire ad libitum et la motivation alimentaire pour un aliment riche en gras et en sucre; ainsi que les comportements de type anxieux. L’injection centrale chronique (21 jours) de ce même agoniste GPR120 III transmis par une pompe osmotique a démontré que les souris placées sous diète hypercalorique (HFD n’ont présenté aucune modification lors de la prise alimentaire ni de gain de poids mais qu’il y avait comparativement au groupe de véhicule, une réduction du comportement de type anxieux, que ce soit dans le labyrinthe en croix surélevé (LCS) ou dans le test à champ ouvert (OFT). L’ADH est reconnu pour ses propriétés anorexigènes au niveau central. De plus, la stimulation des récepteurs de GPR120 au niveau du cerveau avec un agoniste synthétique peut produire un effet intense intervenir sur le comportement lié à l'alimentation des rongeurs. Trouver une approche visant à contrôler à la fois la neuroinflammation, la récompense alimentaire et les troubles émotionnels aiderait assurément au traitement de l'obésité et du diabète de type 2.

Behavioural studies on the ethanol leaf extract of Grewia carpinifolia in Wistar rats.

Background: Grewia carpinifolia is a plant commonly used in the tropics to manage various central nervous system (CNS) disorders. However, despite its widespread use no scientific work has been reported to validate these claims. Objectives: To evaluate the activity of G. carpinifolia as it affects behaviour using animal model. Methods: Twenty five adult Wistar rats were randomly divided into five groups (A-E). Group A served as control (given only distilled water), Groups B,C, D and E were administered with single oral dose of ethanol extract of G. carpinifolia leaf at 100, 200, 400 and 800 mg/kg body weight respectively for twenty eight days consecutively. Subsequently, open field test, negative geotaxis and hanging wire test were performed. Body and brain weights were measured and histological examination of the brain was also performed. Results: At the tested doses, the extract significantly increased the time spent on the hanging wire and decreased locomotor activity at 800 mg/kg. No significant difference was observed in body and brain weights of extract treated groups when compared with the control. No visible histological lesion was also observed. Conclusion: The plant extract may improve muscular strength at tested doses and possess CNS depressant activity at 800 mg/ kg.

Prevalencia de anticuerpos a Neospora caninum en hatos de bovinos lecheros en tres parroquias del cantón Cuenca, Ecuador

La actividad ganadera es una de las principales fuentes de trabajo en nuestro país y particularmente en nuestra provincia, actividad donde la reproducción es uno de los pilares que sostienen la productividad y eficiencia. Estas se ven disminuidas por enfermedades como la neosporosis que, al causar abortos, muerte embrionaria, nacimiento de terneros con ataxia y problemas neuromusculares, etc., produce pérdidas económicas. En el año 2005 no existían en el país datos epidemiológicos de este agente, por lo que se planteó el estudio como para diagnosticar con alta sensibilidad y especificidad, la presencia de anticuerpos a Neospora caninum en hatos lecheros de las parroquias con mayor producción lechera. Los objetivos que se plantearon en el estudio fueron: Determinar la existencia de anticuerpos contra Neospora caninum, mediante la prueba de ELISA, en hembras bovinas de las parroquias de Tarqui, Cumbe y Victoria del Portete Determinar la prevalencia a Neospora caninum en función de la procedencia, la edad, la raza de los animales y los antecedentes de abortos.

A novel mutation of AFG3L2 might cause dominant optic atrophy in patients with mild intellectual disability

International audience

Granulocyte-colony stimulating factor in experimental stroke and its effects on infarct size and functional outcome: a systematic review

Background Granulocyte-colony stimulating factor (G-CSF) shows promise as a treatment for stroke. This systematic review assesses G-CSF in experimental ischaemic stroke. Methods Relevant studies were identified with searches of Medline, Embase and PubMed. Data were extracted on stroke lesion size, neurological outcome and quality, and analysed using Cochrane Review Manager using random effects models; results are expressed as standardised mean difference (SMD) and odds ratio (OR). Results Data were included from 19 publications incorporating 666 animals. G-CSF reduced lesion size significantly in transient (SMD -1.63, p<0.00001) but not permanent (SMD -1.56, p=0.11) focal models of ischaemia. Lesion size was reduced at all doses and with treatment commenced within 4 hours of transient ischaemia. Neurological deficit (SMD -1.37, p=0.0004) and limb placement (SMD -1.88, p=0.003) improved with G-CSF; however, locomotor activity (>4 weeks post ischaemia) was not (SMD 0.76, p=0.35). Death (OR 0.27, p<0.0001) was reduced with G-CSF. Median study quality was 4 (range 0-7/8); Egger’s test suggested significant publication bias (p=0.001). Conclusions G-CSF significantly reduced lesion size in transient but not permanent models of ischaemic stroke. Motor impairment and death were also reduced. Further studies assessing dose-response, administration time, length of ischaemia and long-term functional recovery are needed.

Informe de práctica rotatoria: manejo clínico de la enfermedad articular degenerativa en felinos

Tesis (Médico Veterinario). -- Universidad de La Salle. Facultad de Ciencias Agropecuarias. Programa de Medicina Veterinaria, 2014

Capacidad resolutiva del primer nivel de atención: experiencia de la Unidad Docente-Asistencial de Medicina Familiar y Comunitaria de Paysandú (2014)

Introducción: la resolutividad del primer nivel de atención (PNA) es una cualidad fundamental de los sistemas de salud porque repercute en el funcionamiento de los otros niveles y en los servicios de urgencia. En nuestro país se ha insistido sobre la necesidad de contar con un PNA resolutivo, sustentado en la sobrecarga asistencial que soportan los servicios del segundo nivel de atención (SNA) y las puertas de emergencia de los hospitales o sanatorios, atribuida, entre otros aspectos, a la baja resolutividad del PNA. Objetivos: evaluar las consultas que requirieron traslado a los servicios de emergencia de la Administración de los Servicios de Salud del Estado (ASSE) o de la Corporación Médica de Paysandú (COMEPA), y las referencias realizadas a especialistas del SNA por la Unidad Docente - Asistencial (UDA) N°74 de Paysandú durante 2014. Método: estudio observacional, descriptivo y de corte realizado en cinco servicios del PNA de Paysandú, usando instrumentos de registro específicos. Resultados: de un total de 8.265 consultas realizadas,75 requirieron traslado al servicio de emergencia (0,9%), predominando en adultos jóvenes, en meses de junio y setiembre, debido principalmente a patologías respiratorias, y requiriendo ambulancia en el 49% de los casos. El 5% (n=415) del total de consultas realizadas fueron derivadas al SNA, predominando en adultos mayores de 45 años, y debido a patologías de ojos y anexos, aparato circulatorio y locomotor. Conclusiones: la resolutividad de la UDA de Medicina Familiar y Comunitaria de Paysandú es alta; se valora especialmente las competencias de dicha disciplina en ese sentido, y es posible mejorarla dotando de mayores recursos materiales al PNA (por ejemplo, oftalmoscopio).

Clinical Signs and Symptoms and Laboratory Findings of Methadone Poisoning in Children

Background: Poisoning accounts for about 7% of all accidents in children under 5 years and is implicated in over 5% of all childhood deaths in developing countries. Objectives: Due to the potential risks of methadone poisoning in children and increased cases of methadone poisoning among Iranian children, this study was conducted to investigate the clinical signs and symptoms and laboratory findings of methadone toxicity in children. Patients and Methods: The present retrospective, descriptive, cross-sectional study describes the clinical symptoms and signs and laboratory findings of methadone poisoning in children under 12 years old in Shahid Beheshti Hospital, Kashan, during the years 2009 to 2013. Results: Of 58 patients, 33 (56.9%) were male and 25 (43.1%) female (P = 0.294). The mean age of patients was 5.2 ± 1.0 years. All the cases of poisoning happened with methadone syrup, due to unsafe keeping of methadone in mineral water bottles and containers of other drugs. Signs and symptoms included drowsiness (91.4 %), miosis (75.9%), vomiting (69.0%), ineffective breathing (any kind of breathing problem except apnea) (62.1%), apnea (53.4%), cyanosis (43.1%), seizure (8.6%), ataxia (6.9%) and delirium (3.4%). Conclusions: Keeping methadone in appropriate containers and warning methadone consumers about the dangerous side effects of its consumption and the symptoms of methadone poisoning in children may minimize the occurrence of this form of poisoning and its complications in children.

Different Kinds of Paraneoplastic Syndromes in Childhood Neuroblastoma

Background: Clinical presentations of paraneoplastic syndromes in neuroblastoma may multiply. Review of the clinical data and the literature on this syndrome may help in the diagnosis of neuroblastoma. Objectives: In order to make more accurate diagnosis, we reviewed the clinical data and the literature on this syndrome. Patients and Methods: Between April 2007 and April 2012, 68 children were diagnosed with neuroblastoma or ganglioneuroblastoma in our institution, 9 of which presented exclusively with paraneoplastic syndromes and were not treated with chemotherapy prior to diagnosis. After the diagnosis, all patients received chemotherapy and operation on NB97 protocol. Results: Among 68 pediatric patients with neuroblastoma or ganglioneuroblastoma, 4 (5.9%) patients suffered from neurological complications at diagnosis, 2 (2.9%) patients had digestive tract disorders, 2 (2.9%) patients had immune diseases, and 1 (1.5%) suffered from hematological disorder (without bone marrow involvement). All paraneoplastic syndrome patients achieved complete remission on paraneoplastic syndrome before completion of chemotherapy. Conclusions: Neuroblastoma may present with a range of non-specific neurologic symptoms in addition to the well-known opsoclonus-myoclonus syndrome and cerebellar ataxia. In any case, the presence of unexplained neurologic manifestations and other common clinical presentations such as rash, constipation, diarrhea, and especially immune disorders in an otherwise healthy child had raised the possibility of paraneoplastic syndrome due to the presence of an undiagnosed tumor.