1000 resultados para via enzimática


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• Premise of the study: Polymorphic microsatellite markers were developed in Vinca minor (Apocynaceae) to evaluate the level of clonality, population structure, and genetic diversity of the species within its native and introduced range. • Methods and Results: A total of 1371 microsatellites were found in 43,565 reads from 454 pyrosequencing of genomic V. minor DNA. Additional microsatellite loci were mined from publicly available cDNA sequences. After several rounds of screening, 18 primer pairs flanking di-, tri-, or tetranucleotide repeats were identified that revealed high levels of genetic diversity in two native Italian populations, with two to 11 alleles per locus. Clonal growth predominated in two populations from the introduced range in Germany. Five loci successfully cross-amplified in three additional Vinca species. • Conclusions: The novel polymorphic microsatellite markers are promising tools for studying clonality and population genetics of V. minor and for assessing the historical origin of Central European populations.

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As AI has begun to reach out beyond its symbolic, objectivist roots into the embodied, experientialist realm, many projects are exploring different aspects of creating machines which interact with and respond to the world as humans do. Techniques for visual processing, object recognition, emotional response, gesture production and recognition, etc., are necessary components of a complete humanoid robot. However, most projects invariably concentrate on developing a few of these individual components, neglecting the issue of how all of these pieces would eventually fit together. The focus of the work in this dissertation is on creating a framework into which such specific competencies can be embedded, in a way that they can interact with each other and build layers of new functionality. To be of any practical value, such a framework must satisfy the real-world constraints of functioning in real-time with noisy sensors and actuators. The humanoid robot Cog provides an unapologetically adequate platform from which to take on such a challenge. This work makes three contributions to embodied AI. First, it offers a general-purpose architecture for developing behavior-based systems distributed over networks of PC's. Second, it provides a motor-control system that simulates several biological features which impact the development of motor behavior. Third, it develops a framework for a system which enables a robot to learn new behaviors via interacting with itself and the outside world. A few basic functional modules are built into this framework, enough to demonstrate the robot learning some very simple behaviors taught by a human trainer. A primary motivation for this project is the notion that it is practically impossible to build an "intelligent" machine unless it is designed partly to build itself. This work is a proof-of-concept of such an approach to integrating multiple perceptual and motor systems into a complete learning agent.

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A fundamental question in visual neuroscience is how to represent image structure. The most common representational schemes rely on differential operators that compare adjacent image regions. While well-suited to encoding local relationships, such operators have significant drawbacks. Specifically, each filter's span is confounded with the size of its sub-fields, making it difficult to compare small regions across large distances. We find that such long-distance comparisons are more tolerant to common image transformations than purely local ones, suggesting they may provide a useful vocabulary for image encoding. . We introduce the "Dissociated Dipole," or "Sticks" operator, for encoding non-local image relationships. This operator de-couples filter span from sub-field size, enabling parametric movement between edge and region-based representation modes. We report on the perceptual plausibility of the operator, and the computational advantages of non-local encoding. Our results suggest that non-local encoding may be an effective scheme for representing image structure.

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We propose a nonparametric method for estimating derivative financial asset pricing formulae using learning networks. To demonstrate feasibility, we first simulate Black-Scholes option prices and show that learning networks can recover the Black-Scholes formula from a two-year training set of daily options prices, and that the resulting network formula can be used successfully to both price and delta-hedge options out-of-sample. For comparison, we estimate models using four popular methods: ordinary least squares, radial basis functions, multilayer perceptrons, and projection pursuit. To illustrate practical relevance, we also apply our approach to S&P 500 futures options data from 1987 to 1991.

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We enhance photographs shot in dark environments by combining a picture taken with the available light and one taken with the flash. We preserve the ambiance of the original lighting and insert the sharpness from the flash image. We use the bilateral filter to decompose the images into detail and large scale. We reconstruct the image using the large scale of the available lighting and the detail of the flash. We detect and correct flash shadows. This combines the advantages of available illumination and flash photography.

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Holes with different sizes from microscale to nanoscale were directly fabricated by focused ion beam (FIB) milling in this paper. Maximum aspect ratio of the fabricated holes can be 5:1 for the hole with large size with pure FIB milling, 10:1 for gas assistant etching, and 1:1 for the hole with size below 100 nm. A phenomenon of volume swell at the boundary of the hole was observed. The reason maybe due to the dose dependence of the effective sputter yield in low intensity Gaussian beam tail regions and redeposition. Different materials were used to investigate variation of the aspect ratio. The results show that for some special material, such as Ni-Be, the corresponding aspect ratio can reach 13.8:1 with Cl₂ assistant etching, but only 0.09:1 for Si(100) with single scan of the FIB.

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Conte per a infants guanyador del concurs literari organitzat a la Facultat per celebrar la Diada de St. Jordi 2005 amb el lema "Sentir paraules"

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El braç robot es va crear com a resposta a una necessitat de fabricació d’elements mitjançant la producció en cadena i en tasques que necessiten precisió. Hi ha, però, altres tipus de tasques les quals no són repetitives, ni poden ésser programades, que necessiten però ser controlades en tot moment per un ésser humà. Són activitats que han d’estar realitzades per un ésser humà, però que requereixen molta precisió, és per això que es creu necessari el disseny d’un prototipus de control d’un braç robot estàndard, que permeti a una persona el control total sobre aquest en temps real per a la realització d’una tasca no repetitiva i no programable prèviament. Pretenem, en el present projecte, dissenyar i construir un braç robot de 5 graus de llibertat, controlat des d’un PC mitjançant un microcontrolador PIC amb comunicació a través d’un bus USB. El robot serà governat des d’un PC a través d’un software de control específic

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La Facultat de Lletres de la UdG ha posat en marxa aquest curs 2009-2010 el nou grau en Comunicació Cultural. La proposta innovadora ha tingut com a recompensa el fet que s’han cobert les quaranta places que s’oferien

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The scientific community has been suffering from peer review for decades. This process (also called refereeing) subjects an author's scientific work or ideas to the scrutiny of one or more experts in the field. Publishers use it to select and screen manuscript submissions, and funding agencies use it to award research funds. The goal is to get authors to meet their discipline's standards and thus achieve scientific objectivity. Publications and awards that haven't undergone peer review are often regarded with suspicion by scholars and professionals in many fields. However, peer review, although universally used, has many drawbacks. We propose replacing peer review with an auction-based approach: the better the submitted paper, the more scientific currency the author likely bid to have it published. If the bid correctly reflects the paper's quality, the author is rewarded in this new scientific currency; otherwise, the author loses this currency. We argue that citations are an appropriate currency for all scientists. We believe that citation auctions encourage scientists to better control their submissions' quality. It also inspire them to prepare more exciting talks for accepted papers and to invite discussion of their results at congresses and conferences and among their colleagues. In the long run, citation auctions could have the power to greatly improve scientific research

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La finalitat de la investigació que es presenta és la de millorar el disseny de contextos educatius afavoridors del desenvolupament en l'alumnat de models de pensament, acció i comunicació coincidents amb els principis de la complexitat. Prenent com a focus la comunicació, ens centrem en l'ús del llenguatge i especialment en l'argumentació perquè és a partir d'aquesta que els membres de la ciutadania comparteixen estratègies, negocien punts de vista i defineixen accions per a posicionar-se davant del repte d'afrontar la sostenibilitat (Izquierdo et al., 2004)

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There is a wealth of open educational content in audio and video formats available via iTunes U, one of the services offered especially for education via iTunes. There are details of how to get started as well as an informative video to help you. Details of how to get started with sharing content can be found for developers.

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Introducción: la luxación típica de la cadera es una patología con alta incidencia, de ahí la necesidad de métodos efectivos para lograr una reducción de esta. Han surgido varios métodos de reducción, uno de estos métodos es la reducción abierta por vía interna. Metodología Estudió descriptivo retrospectivo, incluyo los casos operados de reducción abierta por vía interna en el Instituto de Ortopedia Infantil Roosevelt y Clínica Jorge Piñeros Corpas por uno de los tutores, desde enero de 2006 hasta junio de 2011, valorando estas caderas según los criterios de Salter de necrosis avascular (NAV), con un seguimiento mínimo de 18 meses. Se evaluó la concordancia interobservador para la clasificación de Salter en tres ortopedistas infantiles. Resultados Se evaluaron 20 caderas en 16 pacientes a los que se realizo reducción abierta de luxación típica de cadera por vía interna. El 40 % de las caderas presentaron NAV, el 75% de estas caderas presentan NAV tipo I según la clasificación de Kalamchi. El índice Kappa para la clasificación de Salter en tres ortopedistas infantiles fue 0.6. Discusión El abordaje por vía interna para la reducción de luxación de cadera típica en niños menores de 18 meses es una alternativa más para el manejo de estos pacientes, que puede producir NAV en la cadera, pero esta NAV es tipo I de Kalamchi en la mayoría de casos. La reproducibilidad de la radiografía para la evaluación de NAV, realizada por personas expertas es buena, medida con índice kappa de 0.6.

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Se centra en las posibilidades del transporte en bicicleta como sistema para conseguir una movilidad sostenible. El cd-rom se estructura en cuatro apartados: Cómo te desplazas (problemas del tránsito motorizado); El sueño posible (la bicicleta, medio de transporte ecológico y sostenible); Utiliza la bicicleta; Qué sabes de la bicicleta (información práctica).

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En este cuento, Joan, un niño de siete años y medio, explica que su abuela, que vive con él, tiene una enfermedad que se llama Alzheimer, cosa que hace que sea una abuela diferente a las otras. Necesita que alguien esté con ella todo el día.