944 resultados para human artificial chromosome


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[EN]Can automatic vision systems for pedestrian detection be improved by training them on perceptually-defined ROIs?

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[EN]Enabling natural human-robot interaction using computer vision based applications requires fast and accurate hand detection. However, previous works in this field assume different constraints, like a limitation in the number of detected gestures, because hands are highly complex objects difficult to locate. This paper presents an approach which integrates temporal coherence cues and hand detection based on wrists using a cascade classifier. With this approach, we introduce three main contributions: (1) a transparent initialization mechanism without user participation for segmenting hands independently of their gesture, (2) a larger number of detected gestures as well as a faster training phase than previous cascade classifier based methods and (3) near real-time performance for hand pose detection in video streams.

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Une caractéristique intéressante de la protéine Bcl-xL est la présence d'un domaine en boucle non-structurée entre les hélices α1 and α2 de la protéine. Ce domaine protéique n'est pas essentiel pour sa fonction anti-apoptotique et absent chez CED-9, la protéine orthologue chez Caenorhabditis elegans. A l'intérieur de ce domaine, Bcl-xL subit une phosphorylation et déphosphorylation dynamique sur les résidus Ser49 et Ser62 en phase G2 du cycle cellulaire et lors de la mitose. Lorsque ces résidus sont mutés et les protéines exprimées dans des cellules cancéreuses, les cellules démontrent plusieurs défauts mitotiques liés à l'instabilité chromosomique. Pour analyser les effets de Bcl-xL Ser49 et Ser62 dans les cellules normales, les présentes études ont été réalisées dans des cellules diploïdes humaines normales, et in vivo chez Caenorhabditis elegans. Dans une première étude, nous avons utilisé la lignée cellulaire de cellules fibroblastiques diploïdes humaines normales BJ, exprimant Bcl-xL (type sauvage), (S49A), (S49D), (S62A), (S62D) et les double (S49/62A) et (S49/62D) mutants. Les cellules exprimant les mutants de phosphorylation ont montré des cinétiques de doublement de la population cellulaire réduites. Ces effets sur la cinétique de doublement de la population cellulaire corrèle avec l'apparition de la sénescence cellulaire, sans impact sur les taux de mort cellulaire. Ces cellules sénescentes affichent des phénotypes typiques de sénescence associés notamment à haut niveau de l'activité β-galactosidase associée à la sénescence, la sécrétion d' interleukine-6, l'activation de p53 et de p21WAF1/ Cip1, un inhibiteur des complexes kinase cycline-dépendant, ainsi que la formation de foyers de chromatine nucléaire associés à γH2A.X. Les analyses de fluorescence par hybridation in situ et des caryotypes par coloration au Giemsa ont révélé que l'expression des mutants de phosphorylation de Bcl-xL provoquent de l'instabilité chromosomique et l'aneuploïdie. Ces résultats suggèrent que les cycles de phosphorylation et déphosphorylation dynamiques de Bcl-xL Ser49 et Ser62 sont importants dans le maintien de l'intégrité des chromosomes lors de la mitose dans les cellules normales. Dans une deuxième étude, nous avons entrepris des expériences chez Caenorhabditis elegans pour comprendre l'importance des résidus Ser49 et Ser62 de Bcl-xL in vivo. Les vers transgéniques portant les mutations de Bcl-xL (S49A, S62A, S49D, S62D et S49/62A) ont été générés et leurs effets ont été analysés sur les cellules germinales des jeunes vers adultes. Les vers portant les mutations de Bcl-xL ont montré une diminution de ponte et d'éclosion des oeufs, des variations de la longueur de leurs régions mitotiques et des zones de transition, des anomalies chromosomiques à leur stade de diplotène, et une augmentation de l'apoptose des cellules germinales. Certaines de ces souches transgéniques, en particulier les variants Ser/Ala, ont également montré des variations de durée de vie par rapport aux vers témoins. Ces observations in vivo ont confirmé l'importance de Ser49 et Ser62 à l'intérieur du domaine à boucle de Bcl-xL pour le maintien de la stabilité chromosomique. Ces études auront une incidence sur les futures stratégies visant à développer et à identifier des composés qui pourraient cibler non seulement le domaine anti-apoptotique de la protéine Bcl-xL, mais aussi son domaine mitotique pour la thérapie du cancer.

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This work presents a study about a the Baars-Franklin architecture, which defines a model of computational consciousness, and use it in a mobile robot navigation task. The insertion of mobile robots in dynamic environments carries a high complexity in navigation tasks, in order to deal with the constant environment changes, it is essential that the robot can adapt to this dynamism. The approach utilized in this work is to make the execution of these tasks closer to how human beings react to the same conditions by means of a model of computational consci-ousness. The LIDA architecture (Learning Intelligent Distribution Agent) is a cognitive system that seeks tomodel some of the human cognitive aspects, from low-level perceptions to decision making, as well as attention mechanism and episodic memory. In the present work, a computa-tional implementation of the LIDA architecture was evaluated by means of a case study, aiming to evaluate the capabilities of a cognitive approach to navigation of a mobile robot in dynamic and unknown environments, using experiments both with virtual environments (simulation) and a real robot in a realistic environment. This study concluded that it is possible to obtain benefits by using conscious cognitive models in mobile robot navigation tasks, presenting the positive and negative aspects of this approach.

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The structure of hCx26 derived from the X-ray analysis was used to generate a homology model for hCx46. Interacting connexin molecules were used as starting model for the molecular dynamics (MD) simulation using NAMD and allowed us to predict the dynamic behavior of hCx46wt and the cataract related mutant hCx46N188T as well as two artificial mutants hCx46N188Q and hCx46N188D. Within the 50 ns simulation time the docked complex composed of the mutants dissociate while hCx46wt remains stable. The data indicates that one hCx46 molecule forms 5-7 hydrogen bonds (HBs) with the counterpart connexin of the opposing connexon. These HBs appear essential for a stable docking of the connexons as shown by the simulation of an entire gap junction channel and were lost for all the tested mutants. The data described here are related to the research article entitled "The cataract related mutation N188T in human connexin46 (hCx46) revealed a critical role for residue N188 in the docking process of gap junction channels" (Schadzek et al., 2015) [1].

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The natural compliance and force generation properties of pneumatic artificial muscles (PAMs) allow them to operate like human muscles in anthropomorphic robotic manipulators. Traditionally, manipulators use a single PAM or multiple PAMs actuated in unison in place of a human muscle. However, these manipulators experience efficiency losses when operated outside their target performance ranges. The unidirectional actuation behavior of a miniature PAM bundle and bidirectional actuation behavior of an antagonistic pair of miniature PAM bundles are characterized and modeled. The results are used to motivate the application of a variable recruitment control strategy to a parallel bundle of miniature PAMs as an attempt to mimic the selective recruitment of motor units in a human muscle to improve the operating efficiency of the actuator. Additionally, the fabrication and quasi-static testing results for PAMs assembled from candidate space qualified bladder and braided sleeve materials for use in space robotics are assessed.

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Dissertação (mestrado)—Universidade de Brasília, Faculdade Gama, Programa de Pós-Graduação em Engenharia Biomédica, 2015.

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Une caractéristique intéressante de la protéine Bcl-xL est la présence d'un domaine en boucle non-structurée entre les hélices α1 and α2 de la protéine. Ce domaine protéique n'est pas essentiel pour sa fonction anti-apoptotique et absent chez CED-9, la protéine orthologue chez Caenorhabditis elegans. A l'intérieur de ce domaine, Bcl-xL subit une phosphorylation et déphosphorylation dynamique sur les résidus Ser49 et Ser62 en phase G2 du cycle cellulaire et lors de la mitose. Lorsque ces résidus sont mutés et les protéines exprimées dans des cellules cancéreuses, les cellules démontrent plusieurs défauts mitotiques liés à l'instabilité chromosomique. Pour analyser les effets de Bcl-xL Ser49 et Ser62 dans les cellules normales, les présentes études ont été réalisées dans des cellules diploïdes humaines normales, et in vivo chez Caenorhabditis elegans. Dans une première étude, nous avons utilisé la lignée cellulaire de cellules fibroblastiques diploïdes humaines normales BJ, exprimant Bcl-xL (type sauvage), (S49A), (S49D), (S62A), (S62D) et les double (S49/62A) et (S49/62D) mutants. Les cellules exprimant les mutants de phosphorylation ont montré des cinétiques de doublement de la population cellulaire réduites. Ces effets sur la cinétique de doublement de la population cellulaire corrèle avec l'apparition de la sénescence cellulaire, sans impact sur les taux de mort cellulaire. Ces cellules sénescentes affichent des phénotypes typiques de sénescence associés notamment à haut niveau de l'activité β-galactosidase associée à la sénescence, la sécrétion d' interleukine-6, l'activation de p53 et de p21WAF1/ Cip1, un inhibiteur des complexes kinase cycline-dépendant, ainsi que la formation de foyers de chromatine nucléaire associés à γH2A.X. Les analyses de fluorescence par hybridation in situ et des caryotypes par coloration au Giemsa ont révélé que l'expression des mutants de phosphorylation de Bcl-xL provoquent de l'instabilité chromosomique et l'aneuploïdie. Ces résultats suggèrent que les cycles de phosphorylation et déphosphorylation dynamiques de Bcl-xL Ser49 et Ser62 sont importants dans le maintien de l'intégrité des chromosomes lors de la mitose dans les cellules normales. Dans une deuxième étude, nous avons entrepris des expériences chez Caenorhabditis elegans pour comprendre l'importance des résidus Ser49 et Ser62 de Bcl-xL in vivo. Les vers transgéniques portant les mutations de Bcl-xL (S49A, S62A, S49D, S62D et S49/62A) ont été générés et leurs effets ont été analysés sur les cellules germinales des jeunes vers adultes. Les vers portant les mutations de Bcl-xL ont montré une diminution de ponte et d'éclosion des oeufs, des variations de la longueur de leurs régions mitotiques et des zones de transition, des anomalies chromosomiques à leur stade de diplotène, et une augmentation de l'apoptose des cellules germinales. Certaines de ces souches transgéniques, en particulier les variants Ser/Ala, ont également montré des variations de durée de vie par rapport aux vers témoins. Ces observations in vivo ont confirmé l'importance de Ser49 et Ser62 à l'intérieur du domaine à boucle de Bcl-xL pour le maintien de la stabilité chromosomique. Ces études auront une incidence sur les futures stratégies visant à développer et à identifier des composés qui pourraient cibler non seulement le domaine anti-apoptotique de la protéine Bcl-xL, mais aussi son domaine mitotique pour la thérapie du cancer.

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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2016.

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The human immune system has numerous properties that make it ripe for exploitation in the computational domain, such as robustness and fault tolerance, and many different algorithms, collectively termed Artificial Immune Systems (AIS), have been inspired by it. Two generations of AIS are currently in use, with the first generation relying on simplified immune models and the second generation utilising interdisciplinary collaboration to develop a deeper understanding of the immune system and hence produce more complex models. Both generations of algorithms have been successfully applied to a variety of problems, including anomaly detection, pattern recognition, optimisation and robotics. In this chapter an overview of AIS is presented, its evolution is discussed, and it is shown that the diversification of the field is linked to the diversity of the immune system itself, leading to a number of algorithms as opposed to one archetypal system. Two case studies are also presented to help provide insight into the mechanisms of AIS; these are the idiotypic network approach and the Dendritic Cell Algorithm.

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From their early days, Electrical Submergible Pumping (ESP) units have excelled in lifting much greater liquid rates than most of the other types of artificial lift and developed by good performance in wells with high BSW, in onshore and offshore environments. For all artificial lift system, the lifetime and frequency of interventions are of paramount importance, given the high costs of rigs and equipment, plus the losses coming from a halt in production. In search of a better life of the system comes the need to work with the same efficiency and security within the limits of their equipment, this implies the need for periodic adjustments, monitoring and control. How is increasing the prospect of minimizing direct human actions, these adjustments should be made increasingly via automation. The automated system not only provides a longer life, but also greater control over the production of the well. The controller is the brain of most automation systems, it is inserted the logic and strategies in the work process in order to get you to work efficiently. So great is the importance of controlling for any automation system is expected that, with better understanding of ESP system and the development of research, many controllers will be proposed for this method of artificial lift. Once a controller is proposed, it must be tested and validated before they take it as efficient and functional. The use of a producing well or a test well could favor the completion of testing, but with the serious risk that flaws in the design of the controller were to cause damage to oil well equipment, many of them expensive. Given this reality, the main objective of the present work is to present an environment for evaluation of fuzzy controllers for wells equipped with ESP system, using a computer simulator representing a virtual oil well, a software design fuzzy controllers and a PLC. The use of the proposed environment will enable a reduction in time required for testing and adjustments to the controller and evaluated a rapid diagnosis of their efficiency and effectiveness. The control algorithms are implemented in both high-level language, through the controller design software, such as specific language for programming PLCs, Ladder Diagram language.

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Planning, navigation, and search are fundamental human cognitive abilities central to spatial problem solving in search and rescue, law enforcement, and military operations. Despite a wealth of literature concerning naturalistic spatial problem solving in animals, literature on naturalistic spatial problem solving in humans is comparatively lacking and generally conducted by separate camps among which there is little crosstalk. Addressing this deficiency will allow us to predict spatial decision making in operational environments, and understand the factors leading to those decisions. The present dissertation is comprised of two related efforts, (1) a set of empirical research studies intended to identify characteristics of planning, execution, and memory in naturalistic spatial problem solving tasks, and (2) a computational modeling effort to develop a model of naturalistic spatial problem solving. The results of the behavioral studies indicate that problem space hierarchical representations are linear in shape, and that human solutions are produced according to multiple optimization criteria. The Mixed Criteria Model presented in this dissertation accounts for global and local human performance in a traditional and naturalistic Traveling Salesman Problem. The results of the empirical and modeling efforts hold implications for basic and applied science in domains such as problem solving, operations research, human-computer interaction, and artificial intelligence.

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A link between patterns of pelvic growth and human life history is supported by the finding that, cross-culturally, variation in maturation rates of female pelvis are correlated with variation in ages of menarche and first reproduction, i.e., it is well known that the human dimensions of the pelvic bones depend on the gender and vary with the age. Indeed, one feature in which humans appear to be unique is the prolonged growth of the pelvis after the age of sexual maturity. Both the total superoinferior length and mediolateral breadth of the pelvis continues to grow markedly after puberty, and do not reach adult proportions until the late teens years. This continuation of growth is accomplished by relatively late fusion of the separate centers of ossification that form the bones of the pelvis. Hence, in this work we will focus on the development of an intelligent decision support system to predict individual’s age based on a pelvis' dimensions criteria. Some basic image processing techniques were applied in order to extract the relevant features from pelvic X-rays, being the computational framework built on top of a Logic Programming approach to Knowledge Representation and Reasoning that caters for the handling of incomplete, unknown, or even self-contradictory information, complemented with a Case Base approach to computing.