Development of an ex vivo organ culture model using human gastro-intestinal tissue and Campylobacter jejuni.

Campylobacter jejuni is an important food-borne pathogen. However, relatively little is understood regarding its pathogenesis, and research is hampered by the lack of a suitable model. Recently, a number of groups have developed assays to study the pathogenic mechanisms of C. jejuni using cell culture models. Here, we report the development of an ex vivo organ culture model, allowing for the maintenance of intestinal mucosal tissue, to permit more complex host-bacterium interactions to be studied. Ex vivo organ culture highlights the propensity for C. jejuni to adhere to mucosal tissue via the flagellum, either as discrete colonies or as multicellular units.

Fundamento iusfilosófico de la privacidad y del derecho subjetivo de protección de datos personales

Resumen: Es habitual que en la fundamentación de derecho de la privacidad se acuda al valor de la dignidad humana, pero cuando los autores realizan esa vinculación suelen entender a la dignidad hu - mana como justificada en la mera autonomía del sujeto. Para este punto de vista que denominamos visión moderna, en el ámbito de los derechos fundamentales existe un amplio e indefinido campo de libertad, y esta libertad es o sería el derecho básico en sí mismo, o derecho fundamental por antonomasia. Esto significa la concepción del derecho entendido bajo su faz subjetiva. El derecho como un mero poder cuyo límite está en el poder o la facultad de otro, y el Estado como arbitrador de esos poderes subjetivos en pugna. Sin embargo, los derechos fundamentales entre los que se encuentran el derecho a la intimidad y a la privacidad, el derecho al resguardo del honor y de la imagen, encuentran su justificación en lo justo objetivo y en la dignidad humana. La dignidad como un valor que da sentido se justifica cuando es entendida con una apertura a la trascendencia de la persona, y a un fin objetivo al que dicha trascendencia se encamina.

Robot navigation in dense crowds : statistical models and experimental studies of human robot cooperation

This thesis explores the problem of mobile robot navigation in dense human crowds. We begin by considering a fundamental impediment to classical motion planning algorithms called the freezing robot problem: once the environment surpasses a certain level of complexity, the planner decides that all forward paths are unsafe, and the robot freezes in place (or performs unnecessary maneuvers) to avoid collisions. Since a feasible path typically exists, this behavior is suboptimal. Existing approaches have focused on reducing predictive uncertainty by employing higher fidelity individual dynamics models or heuristically limiting the individual predictive covariance to prevent overcautious navigation. We demonstrate that both the individual prediction and the individual predictive uncertainty have little to do with this undesirable navigation behavior. Additionally, we provide evidence that dynamic agents are able to navigate in dense crowds by engaging in joint collision avoidance, cooperatively making room to create feasible trajectories. We accordingly develop interacting Gaussian processes, a prediction density that captures cooperative collision avoidance, and a "multiple goal" extension that models the goal driven nature of human decision making. Navigation naturally emerges as a statistic of this distribution.

Most importantly, we empirically validate our models in the Chandler dining hall at Caltech during peak hours, and in the process, carry out the first extensive quantitative study of robot navigation in dense human crowds (collecting data on 488 runs). The multiple goal interacting Gaussian processes algorithm performs comparably with human teleoperators in crowd densities nearing 1 person/m², while a state of the art noncooperative planner exhibits unsafe behavior more than 3 times as often as the multiple goal extension, and twice as often as the basic interacting Gaussian process approach. Furthermore, a reactive planner based on the widely used dynamic window approach proves insufficient for crowd densities above 0.55 people/m². We also show that our noncooperative planner or our reactive planner capture the salient characteristics of nearly any dynamic navigation algorithm. For inclusive validation purposes, we show that either our non-interacting planner or our reactive planner captures the salient characteristics of nearly any existing dynamic navigation algorithm. Based on these experimental results and theoretical observations, we conclude that a cooperation model is critical for safe and efficient robot navigation in dense human crowds.

Finally, we produce a large database of ground truth pedestrian crowd data. We make this ground truth database publicly available for further scientific study of crowd prediction models, learning from demonstration algorithms, and human robot interaction models in general.

Characterization of the neural mechanisms supporting the implementation of cognitive control in human decision making

Humans are particularly adept at modifying their behavior in accordance with changing environmental demands. Through various mechanisms of cognitive control, individuals are able to tailor actions to fit complex short- and long-term goals. The research described in this thesis uses functional magnetic resonance imaging to characterize the neural correlates of cognitive control at two levels of complexity: response inhibition and self-control in intertemporal choice. First, we examined changes in neural response associated with increased experience and skill in response inhibition; successful response inhibition was associated with decreased neural response over time in the right ventrolateral prefrontal cortex, a region widely implicated in cognitive control, providing evidence for increased neural efficiency with learned automaticity. We also examined a more abstract form of cognitive control using intertemporal choice. In two experiments, we identified putative neural substrates for individual differences in temporal discounting, or the tendency to prefer immediate to delayed rewards. Using dynamic causal models, we characterized the neural circuit between ventromedial prefrontal cortex, an area involved in valuation, and dorsolateral prefrontal cortex, a region implicated in self-control in intertemporal and dietary choice, and found that connectivity from dorsolateral prefrontal cortex to ventromedial prefrontal cortex increases at the time of choice, particularly when delayed rewards are chosen. Moreover, estimates of the strength of connectivity predicted out-of-sample individual rates of temporal discounting, suggesting a neurocomputational mechanism for variation in the ability to delay gratification. Next, we interrogated the hypothesis that individual differences in temporal discounting are in part explained by the ability to imagine future reward outcomes. Using a novel paradigm, we imaged neural response during the imagining of primary rewards, and identified negative correlations between activity in regions associated the processing of both real and imagined rewards (lateral orbitofrontal cortex and ventromedial prefrontal cortex, respectively) and the individual temporal discounting parameters estimated in the previous experiment. These data suggest that individuals who are better able to represent reward outcomes neurally are less susceptible to temporal discounting. Together, these findings provide further insight into role of the prefrontal cortex in implementing cognitive control, and propose neurobiological substrates for individual variation.

Soberania e acumulação de capital: uma análise crítica de Hugo Grotius, Pasquale Mancini e Hans Kelsen

A soberania já foi conceituada de diversos modos ao longo da história. Apesar disso, não deixou de ser a categoria mais elementar do direito internacional; expressando o fundamento de atuação dos Estados, foi através da soberania que o direito internacional se desenvolveu do Século XVII até os dias de hoje. Isso evidencia uma distinção entre o conteúdo da soberania, quer dizer, o seu modo de manifestação, o seu conceito, que se altera em cada período histórico, de um lado, e, do outro, a forma jurídica internacional expressa pela soberania, que se mantém intacta e que existe independentemente do conteúdo que lhe é dado, quer dizer, o lugar que ela ocupa no direito internacional. Através da análise do conceito de soberania fornecido por três autores clássicos de diferentes períodos históricos Hugo Grotius, Pasquale Mancini e Hans Kelsen o presente trabalho tem por objetivo demonstrar o caráter ideológico de cada teoria e, conseqüentemente, sua inexatidão. Para fazê-lo, foi adotado o método materialista dialético, através do qual a produção de idéias por parte do homem deve ser observada nos limites das suas condições de existência e as idéias produzidas como um reflexo consciente do mundo real. Cuida-se, assim, de observar o direito de superioridade afirmado por Grotius nos limites das condições de existência humana que se alteravam com a transição do feudalismo para capitalismo, e extrai-se o seu sentido da luta entre a Igreja e os monarcas que iam centralizando sob si o poder. Da mesma forma, observa-se o direito de nacionalidade de Mancini sob as condições de existência propiciadas pelo amadurecimento das classes sociais do capitalismo na Europa Ocidental como fruto da Revolução Industrial, extraindo-se seu sentido das lutas revolucionárias por libertação nacional que ali se desenrolavam. O caráter essencialmente limitado da soberania de Kelsen, enfim, será observado no contexto da passagem do capitalismo para sua época imperialista, como um reflexo consciente dos desenvolvimentos experimentados pelo direito internacional no fim do Século XIX e início do Século XX, após a Primeira Guerra Mundial. Assim, além de demonstrar o caráter ideológico e a inexatidão dos conceitos mencionados, busca-se demonstrar que o conteúdo da soberania em cada período histórico analisado encontra sua razão de ser na correspondente fase de desenvolvimento do capitalismo e que a forma jurídica soberania, isto é, o lugar que ela ocupa no direito internacional, é determinado pela necessidade do capitalismo de um instrumento de força que assegure a acumulação de capital, o Estado soberano.

Information processing and higher psychological functions in the disconnected hemispheres of human commissurotomy patients

Several patients of P. J. Vogel who had undergone cerebral commissurotomy for the control of intractable epilepsy were tested on a variety of tasks to measure aspects of cerebral organization concerned with lateralization in hemispheric function. From tests involving identification of shapes it was inferred that in the absence of the neocortical commissures, the left hemisphere still has access to certain types of information from the ipsilateral field. The major hemisphere can still make crude differentiations between various left-field stimuli, but is unable to specify exact stimulus properties. Most of the time the major hemisphere, having access to some ipsilateral stimuli, dominated the minor hemisphere in control of the body.

Competition for control of the body between the hemispheres is seen most clearly in tests of minor hemisphere language competency, in which it was determined that though the minor hemisphere does possess some minimal ability to express language, the major hemisphere prevented its expression much of the time. The right hemisphere was superior to the left in tests of perceptual visualization, and the two hemispheres appeared to use different strategies in attempting to solve the problems, namely, analysis for the left hemisphere and synthesis for the right hemisphere.

Analysis of the patients' verbal and performance I.Q.'s, as well as observations made throughout testing, suggest that the corpus callosum plays a critical role in activities that involve functions in which the minor hemisphere normally excels, that the motor expression of these functions may normally come through the major hemisphere by way of the corpus callosum.

Lateral specialization is thought to be an evolutionary adaptation which overcame problems of a functional antagonism between the abilities normally associated with the two hemispheres. The tests of perception suggested that this function lateralized into the mute hemisphere because of an active counteraction by language. This latter idea was confirmed by the finding that left-handers, in whom there is likely to be bilateral language centers, are greatly deficient on tests of perception.

Control mechanisms in the human binocular oculomotor system

A study of human eye movements was made in order to elucidate the nature of the control mechanism in the binocular oculomotor system.

We first examined spontaneous eye movements during monocular and binocular fixation in order to determine the corrective roles of flicks and drifts. It was found that both types of motion correct fixational errors, although flicks are somewhat more active in this respect. Vergence error is a stimulus for correction by drifts but not by flicks, while binocular vertical discrepancy of the visual axes does not trigger corrective movements.

Second, we investigated the non-linearities of the oculomotor system by examining the eye movement responses to point targets moving in two dimensions in a subjectively unpredictable manner. Such motions consisted of hand-limited Gaussian random motion and also of the sum of several non-integrally related sinusoids. We found that there is no direct relationship between the phase and the gain of the oculomotor system. Delay of eye movements relative to target motion is determined by the necessity of generating a minimum afferent (input) signal at the retina in order to trigger corrective eye movements. The amplitude of the response is a function of the biological constraints of the efferent (output) portion of the system: for target motions of narrow bandwidth, the system responds preferentially to the highest frequency; for large bandwidth motions, the system distributes the available energy equally over all frequencies. Third, the power spectra of spontaneous eye movements were compared with the spectra of tracking eye movements for Gaussian random target motions of varying bandwidths. It was found that there is essentially no difference among the various curves. The oculomotor system tracks a target, not by increasing the mean rate of impulses along the motoneurons of the extra-ocular muscles, but rather by coordinating those spontaneous impulses which propagate along the motoneurons during stationary fixation. Thus, the system operates at full output at all times.

Fourth, we examined the relative magnitude and phase of motions of the left and the right visual axes during monocular and binocular viewing. We found that the two visual axes move vertically in perfect synchronization at all frequencies for any viewing condition. This is not true for horizontal motions: the amount of vergence noise is highest for stationary fixation and diminishes for tracking tasks as the bandwidth of the target motion increases. Furthermore, movements of the occluded eye are larger than those of the seeing eye in monocular viewing. This effect is more pronounced for horizontal motions, for stationary fixation, and for lower frequencies.

Finally, we have related our findings to previously known facts about the pertinent nerve pathways in order to postulate a model for the neurological binocular control of the visual axes.

Integralidade no cuidado à saúde da mulher: refletindo sobre a atuação dos profissionais em unidades básicas de saúde do município de Toledo PR

Este estudo tem como objetivo entender como as práticas de saúde das mulheres são desenvolvidas pelos profissionais de saúde, frente ao princípio de integralidade, em unidades básicas de saúde de um município do Estado do Paraná. O estudo teve como suporte teórico a integralidade da atenção, não só como princípio do SUS, mas também como exercício de boas práticas de produção de cuidado que devem estar presentes no atendimento das necessidades de saúde das mulheres, em busca da conquista de uma saúde mais digna e solidária para todos. O Sistema Único de Saúde deve estar orientado e capacitado para a atenção integral à saúde da mulher, numa perspectiva que contempla a promoção da saúde, a proteção e a prevenção às necessidades de saúde da população feminina, o controle de patologias mais prevalentes nesse grupo e a garantia do direito à saúde. Por esta razão, a humanização e a qualidade da atenção implicam promoção, reconhecimento e respeito aos direitos humanos, garantindo a saúde integral e seu bem-estar. A metodologia envolveu uma abordagem qualitativa realizada em duas unidades básicas de saúde do município de Toledo-PR. Utilizou-se como técnica de coleta de dados a observação a 15 atendimentos médicos a mulheres em ginecologia e clínico geral e entrevista com 10 mulheres freqüentadoras de duas unidades de saúde. A análise do material produzido foi organizada em torno de certos aspectos-chave de certas categorias. Identificamos, nos atendimentos observados, que há uma cordialidade desintegral dos profissionais que atendem às mulheres com certa gentileza, mas que ao mesmo tempo são desatentos a certos aspectos fundamentais de um atendimento integral. Deixam a desejar do ponto de vista técnico, comprometendo a integralidade do atendimento, focando sua atenção na queixa principal trazida pela mulher, com atendimentos restritos somente na conversa, ou exame clínico centrado na queixa principal, não explorando aspectos para a prevenção. Tornam, assim, o atendimento seletivo e centralizado, mas cercado por uma cordialidade junto às mulheres, que classificam tal cordialidade como uma sensação de bom atendimento, satisfação ilusória do ponto de vista técnico, em que a atenção clínica não responde a suas necessidades. Estas mulheres não reconhecem esta má prática, relatando uma resolutividade no atendimento diante da resolução da queixa imediata, como o acesso a alguns exames, medicamentos. Identificamos também que algumas mulheres sonham com um atendimento integral, e em alguns atendimentos se percebe a tentativa do profissional de buscar uma atenção que vá além da queixa principal, buscando entender com se dá o modo de andar a vida de certas mulheres. Concluímos que desafios ainda são colocados quando olhamos para a organização dos serviços de saúde na perspectiva da atenção integral. Considera-se fundamental a organização dos serviços de saúde para estarem pautados em cuidados efetivos à saúde da mulher, em busca da produção da integralidade que será traduzida em mais saúde para as mulheres.

Tutela penal ambiental: necessidade, adequação e viabilidade

O presente trabalho apresenta um estudo da tutela jurídica do meio ambiente, especificamente pela utilização do ramo penal. Como a natureza é um bem jurídico importante para a viabilidade da vida dos seres humanos e a perpetuação da espécie, resta clara a relevância da proteção normativa deste valor constitucionalmente protegido. Uma vez previsto na Constituição da República Federativa do Brasil de 1988, há uma ordem constitucional para o meio ambiente ser objeto de tutela pelos ramos civil, administrativo e penal. Contudo, a coexistência destas esferas para a mesma finalidade encontra certos problemas de ordem prática e técnica. Depois de uma abordagem histórica, política, social e filosófica da proteção ambiental, a dissertação discorre sobre os diversos âmbitos jurídicos que asseguram a perpetuação do verde para as futuras gerações e sua manutenção para os cidadãos da atualidade. Depois de um estudo sobre os diversos elementos do direito administrativo e civil, o penal é analisado especificamente. Esta abordagem abrange tanto doutrinas nacionais, como internacionais. O estudo de Direito Comparado apresenta todas as formas e possibilidades de proteção ambiental pelo direito penal, verificando sua necessidade, adequação e viabilidade para tanto.

Workspace comparisons of setup configurations for human-robot interaction

In virtual assembly verification or remote maintenance tasks, bimanual haptic interfaces play a crucial role in successful task completion. This paper proposes a method for objectively comparing how well a haptic interface covers the reachable workspace of human arms. Two system configurations are analyzed for a recently introduced haptic device that is based on two DLR-KUKA light weight robots: the standard configuration, where the device is opposite the human operator, and the ergonomic configuration, where the haptic device is mounted behind the human operator. The human operator directly controls the robotic arms using handles. The analysis is performed using a representation of the robot arm workspace. The merits of restricting the comparisons to the most significant regions of the human workspace are discussed. Using this method, a greater workspace correspondence for the ergonomic configuration was shown. ©2010 IEEE.

Hepatocyte growth factor enhances the generation of high-purity oligodendrocytes from human embryonic stem cells

Generation of homogeneous oligodendrocytes as donor cells is essential for human embryonic stem cell (hESC)-based cell therapy for demylinating diseases. Herein we present a novel method for efficiently obtaining mature oligodendrocytes from hESCs with high purity (79.7 +/- 6.9%), using hepatocyte growth factor (HGF) and G5 supplement(containing insulin, transferrin, selenite, biotin, hydrocortisone, basic fibroblast growth factor and epidermal growth factor) in a four-step method. We induced hESCs into neural progenitors (NP) with HGF (5 ng/ml) and G5 (1 x) supplemented medium in an adherent differentiation system. The purified NPs were amplified in suspension as neurospheres for 1 month, and terminal oligodendrocyte differentiation was then induced by G5 supplement withdrawal and HGF treatment (20 ng/ml). The cells generated displayed typical morphologies of mature oligodendrocytes and expressed oligodendrocyte markers O4 and myelin basic protein (MBP). Our result revealed that HGF significantly enhanced the proliferation of hESC-derived NPs and promoted the differentiation as well as the maturation of oligodendrocytes from NPs. Further studies suggest that HGF/c-Met signaling pathway might play an important role in oligodendrocyte differentiation in our system. Our studies provide a means for generating the clinically relevant cell type and a platform for deciphering the molecular mechanisms that control oligodendrocyte differentiation. (C) 2009 International Society of Differentiation. Published by Elsevier Ltd. All rights reserved.

Altitudinal Ranging of Black-Crested Gibbons at Mt. Wuliang, Yunnan: Effects of Food Distribution, Temperature and Human Disturbance

We studied the altitudinal ranging of one habituated group of black-crested gibbons (Nomascus concolor) at Dazhaizi, Mt. Wuliang, Yunnan, China, between March 2005 and April 2006. The group ranged from 1,900 to 2,680 m above sea level. Food distribution was the driving force behind the altitudinal ranging patterns of the study group. They spent 83.2% of their time ranging between 2,100 and 2,400 m, where 75.8% of important food patches occurred. They avoided using the area above 2,500 m despite a lack of human disturbance there, apparently because there were few food resources. Temperature had a limited effect on seasonal altitudinal ranging but probably explained the diel altitudinal ranging of the group, which tended to use the lower zone in the cold morning and the higher zone in the warm afternoon. Grazing goats, the main disturbance, were limited to below 2,100 m, which was defined as the high-disturbance area (HDA). Gibbons spent less time in the HDA and, when ranging there, spent more time feeding and travelling and less time resting and singing. Human activities directly influenced gibbon behaviour, might cause forest degradation and create dispersal barriers between populations. Copyright (C) 2010 S. Karger AG, Basel

Maintenance of Multifemale Social Organization in a Group of Nomascus concolor at Wuliang Mountain, Yunnan, China

Many short-term studies have reported groups of black crested gibbons containing >= 2 adult females (Nomascus concolor). We report the stability of multifemale groups in this species over a period of 6 yr. Our focal group and 2 neighboring groups included 2 breeding females between March 2003 and June 2009. We also habituated 1 multifemale group to observers and present detailed information concerning their social relationships over a 9-mo observation period. We investigated interindividual distances and agonistic behavior among the 5 group members. The spatial relationship between the 3 adult members (1 male, 2 females) formed an equilateral triangle. A subadult male was peripheral to the focal group, while a juvenile male maintained a closer spatial relationship with the adult members. We observed little agonistic behavior among the adult members. The close spatial relationship and lack of high rates of agonistic behavior among females suggest that the benefits of living in a multifemale group were equal to or greater than the costs for both females, given their ecological and social circumstances. The focal group occupied a large home range that was likely to provide sufficient food sources for the 2 females and their offspring. Between March 2003 and June 2009, 1 adult female gave 2 births and the other one gave 1 birth. All individuals in the focal group survived to June 2009. A long-term comparative study focused on females living in multifemale groups and females living in pair-living groups would provide insight into understanding the evolutionary mechanisms of the social system in gibbons.

Molecular modeling on human CCR5 receptors and complex with CD4 antigens and HIV-1 envelope glycoprotein gp120

AIM: To investigate the interaction between human CCR5 receptors (CCR5) and HIV-1 envelope glycoprotein gp120 (HIV-1 gp120) and HIV-1 receptor CD4 antigens (CD4). METHODS: The structurally con served regions (SCR) of human CCR5 was built by the SYBYL/Biopolymer module using the corresponding transmembrane (TM) domain of bacteriorhodopsin (bR) as the template. The coordinates for amino-ter minal residue sequence, and carboxyl-terminal residue sequence, extracellular and cytoplasmic loops were generated using LOOP SEARCH algorithm. Subsequently the structural model was merged into the complex with HIV-1 gp120 and CD4. RESULTS: Human CCR5 interacted with both an HIV-1 gp120 and CD4. The N-terminal residues (especially Met1 and Gln4) of human CCR5, contacted with CD4 residues, mainly 7Nith one span (56 - 59) of CD4 in electrostatic interaction and hydrogen-bonds. The binding sites of human CCR5 were buried in a hydrophobic center surrounded by a highly basic periphery. On the other hand, direct interatomic contacts were made between ? CCR5 residues and 6 gp120 amino-acid residues, which included van der Waals contacts, hydrophobic interaction, and hydrogen bonds. CONCLUSION: The interaction model should be helpful for rational design of novel anti-HIV drugs.