208 resultados para artefact, airbubble


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BACKGROUND Deep brain stimulation (DBS) is recognized as an effective treatment for movement disorders. We recently changed our technique, limiting the number of brain penetrations to three per side. OBJECTIVES The first aim was to evaluate the electrode precision on both sides of surgery since we implemented this surgical technique. The second aim was to analyse whether or not the electrode placement was improved with microrecording and macrostimulation. METHODS We retrospectively reviewed operation protocols and MRIs of 30 patients who underwent bilateral DBS. For microrecording and macrostimulation, we used three parallel channels of the 'Ben Gun' centred on the MRI-planned target. Pre- and post-operative MRIs were merged. The distance between the planned target and the centre of the implanted electrode artefact was measured. RESULTS There was no significant difference in targeting precision on both sides of surgery. There was more intra-operative adjustment of the second electrode positioning based on microrecording and macrostimulation, which allowed to significantly approach the MRI-planned target on the medial-lateral axis. CONCLUSION There was more electrode adjustment needed on the second side, possibly in relation with brain shift. We thus suggest performing a single central track with electrophysiological and clinical assessment, with multidirectional exploration on demand for suboptimal clinical responses.

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In this contribution, results from Nf = 2 lattice QCD simulations at one lattice spacing using twisted mass fermions with a clover term at the physical pion mass are presented. The mass splitting between charged and neutral pions (including the disconnected contribution) is shown to be around 20(20) MeV. Further, a first measurement using the clover twisted mass action of the average momentum fraction of the pion is given. Finally, an analysis of pseudoscalar meson masses and decay constants is presented involving linear interpolations in strange and charm quark masses. Matching to meson mass ratios allows the calculation of quark mass ratios: ms=ml = 27:63(13), mc=ml = 339:6(2:2) and mc=ms = 12:29(10). From this mass matching the quantities fK = 153:9(7:5) MeV, fD = 219(11) MeV, fDs = 255(12) MeV and MDs = 1894(93) MeV are determined without the application of finite volume or discretization artefact corrections and with errors dominated by a preliminary estimate of the lattice spacing.

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The objective of this research has been to study the molecular basis for chromosome aberration formation. Predicated on a variety of data, Mitomycin C (MMC)-induced DNA damage has been postulated to cause the formation of chromatid breaks (and gaps) by preventing the replication of regions of the genome prior to mitosis. The basic protocol for these experiments involved treating synchronized Hela cells in G(,1)-phase with a 1 (mu)g/ml dose of MMC for one hour. After removing the drug, cells were then allowed to progress to mitosis and were harvested for analysis by selective detachment. Utilizing the alkaline elution assay for DNA damage, evidence was obtained to support the conclusion that Hela cells can progress through S-phase into mitosis with intact DNA-DNA interstrand crosslinks. A higher level of crosslinking was observed in those cells remaining in interphase compared to those able to reach mitosis at the time of analysis. Dual radioisotope labeling experiments revealed that, at this dose, these crosslinks were associated to the same extent with both parental and newly replicated DNA. This finding was shown not to be the result of a two-step crosslink formation mechanism in which crosslink levels increase with time after drug treatment. It was also shown not to be an artefact of the double-labeling protocol. Using neutral CsCl density gradient ultracentrifugation of mitotic cells containing BrdU-labeled newly replicated DNA, control cells exhibited one major peak at a heavy/light density. However, MMC-treated cells had this same major peak at the heavy/light density, in addition to another minor peak at a density characteristic for light/light DNA. This was interpreted as indicating either: (1) that some parental DNA had not been replicated in the MMC treated sample or; (2) that a recombination repair mechanism was operational. To distinguish between these two possibilities, flow cytometric DNA fluorescence (i.e., DNA content) measurements of MMC-treated and control cells were made. These studies revealed that the mitotic cells that had been treated with MMC while in G(,1)-phase displayed a 10-20% lower DNA content than untreated control cells when measured under conditions that neutralize chromosome condensation effects (i.e., hypotonic treatment). These measurements were made under conditions in which the binding of the drug, MMC, was shown not to interfere with the stoichiometry of the ethidium bromide-mithramycin stain. At the chromosome level, differential staining techniques were used in an attempt to visualize unreplicated regions of the genome, but staining indicative of large unreplicated regions was not observed. These results are best explained by a recombinogenic mechanism. A model consistent with these results has been proposed.^

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The western warm pools of the Atlantic and Pacific oceans are a critical source of heat and moisture for the tropical climate system. Over the past five million years, global mean temperatures have cooled by 3-4 °C. Yet, current reconstructions of sea surface temperatures indicate that temperature in the warm pools has remained stable during this time. This stability has been used to suggest that tropical sea-surface temperatures are controlled by some sort of thermostat-like regulation. Here we reconstruct sea surface temperatures in the South China Sea, Caribbean Sea and western equatorial Pacific Ocean for the past five million years, using a combination of the Mg/Ca, TEXH86-and Uk'37 surface temperature proxies. Our data indicate that during the period of Pliocene warmth from about 5 to 2.6 million years ago, the western Pacific and western Atlantic warm pools were about 2 °C warmer than today. We suggest that the apparent lack of warming seen in the previous reconstructions was an artefact of low seawater Mg/Ca ratios in the Pliocene oceans. Taking this bias into account, our data indicate that tropical sea surface temperatures did change in conjunction with global mean temperatures. We therefore conclude that the temperature of the warm pools of the equatorial oceans during the Pliocene was not limited by a thermostat-like mechanism.

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The most direct method of investigating past variations of the atmospheric CO2 concentration before 1958, when continuous direct atmospheric CO2 measurements started, is the analysis of air extracted from suitable ice cores. Here we present a new detailed CO2 record from the Dronning Maud Land (DML) ice core, drilled in the framework of the European Project for Ice Coring in Antarctica (EPICA) and some new measurements on a previously drilled ice core from the South Pole. The DML CO2 record shows an increase from about 278 to 282 parts per million by volume (ppmv) between ad 1000 and ad 1200 and a fairly continuous decrease to a mean value of about 277 ppmv around ad 1700. While the new South Pole measurements agree well with DML at the minimum at ad 1700 they are on average about 2 ppmv lower during the period ad 1000-1500. Published measurements from the coastal high-accumulation site Law Dome are considered as very reliable because of the reproducibility of the measurements, high temporal resolution and an accurate time scale. Other Antarctic ice cores could not, or only partly, reproduce the pre-industrial measurements from Law Dome. A comparison of the trends of DML and Law Dome shows a general agreement. However we should be able to rule out co-variations caused by the same artefact. Two possible effects are discussed, first production of CO2 by chemical reactions and second diffusion of dissolved air through the ice matrix into the bubbles. While the first effect cannot be totally excluded, comparison of the Law Dome and DML record shows that dissolved air diffusing to bubbles cannot be responsible for the pre-industrial variation. Therefore, the new record is not a proof of the Law Dome results but the first very strong support from an ice core of the Antarctic plateau.

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En 1588, el inventor italiano Agostino Ramelli publicó el libro Le diverse et artificiose machine. Entre las muchas máquinas de ingeniería hidráulica y militar, un total de 195 aparatos, destaca un artilugio construido para facilitar la lectura de varios libros a la vez. Esta llamada "rueda de libros" se suele citar en publicaciones recientes como precursora del hipertexto ya que esta máquina para leer permite saltar de un texto a otro de la misma manera que nos movemos entre páginas WEB y módulos textuales. Se trata de una invención que los investigadores describen como reacción al desafío que plantea la enorme cantidad de saber libresco que circula gracias a otra invención que era la imprenta con letras móviles. Aunque muy posiblemente nunca hubiera llegado a construirse, se trata de un artefacto que funciona potencialmente como una máquina de producir textos o, dicho de otra manera, como dispositivo de impulsar un determinado tipo de escritura. Me propongo leer florilegios, obras enciclopédicas y polianteas como Lugares comunes de Juan de Aranda o la escritura enciclopédica en obras como el Guzmán de Alfarache, La pícara Justina o el Libro de todas las cosas como productos virtuales de la rueda de libros.

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En 1588, el inventor italiano Agostino Ramelli publicó el libro Le diverse et artificiose machine. Entre las muchas máquinas de ingeniería hidráulica y militar, un total de 195 aparatos, destaca un artilugio construido para facilitar la lectura de varios libros a la vez. Esta llamada "rueda de libros" se suele citar en publicaciones recientes como precursora del hipertexto ya que esta máquina para leer permite saltar de un texto a otro de la misma manera que nos movemos entre páginas WEB y módulos textuales. Se trata de una invención que los investigadores describen como reacción al desafío que plantea la enorme cantidad de saber libresco que circula gracias a otra invención que era la imprenta con letras móviles. Aunque muy posiblemente nunca hubiera llegado a construirse, se trata de un artefacto que funciona potencialmente como una máquina de producir textos o, dicho de otra manera, como dispositivo de impulsar un determinado tipo de escritura. Me propongo leer florilegios, obras enciclopédicas y polianteas como Lugares comunes de Juan de Aranda o la escritura enciclopédica en obras como el Guzmán de Alfarache, La pícara Justina o el Libro de todas las cosas como productos virtuales de la rueda de libros.

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En 1588, el inventor italiano Agostino Ramelli publicó el libro Le diverse et artificiose machine. Entre las muchas máquinas de ingeniería hidráulica y militar, un total de 195 aparatos, destaca un artilugio construido para facilitar la lectura de varios libros a la vez. Esta llamada "rueda de libros" se suele citar en publicaciones recientes como precursora del hipertexto ya que esta máquina para leer permite saltar de un texto a otro de la misma manera que nos movemos entre páginas WEB y módulos textuales. Se trata de una invención que los investigadores describen como reacción al desafío que plantea la enorme cantidad de saber libresco que circula gracias a otra invención que era la imprenta con letras móviles. Aunque muy posiblemente nunca hubiera llegado a construirse, se trata de un artefacto que funciona potencialmente como una máquina de producir textos o, dicho de otra manera, como dispositivo de impulsar un determinado tipo de escritura. Me propongo leer florilegios, obras enciclopédicas y polianteas como Lugares comunes de Juan de Aranda o la escritura enciclopédica en obras como el Guzmán de Alfarache, La pícara Justina o el Libro de todas las cosas como productos virtuales de la rueda de libros.

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Lichens, symbiotic associations of fungi (mycobionts) and green algae or cyanobacteria (photobionts), are poikilohydric organisms that are particularly well adapted to withstand adverse environmental conditions. Terrestrial ecosystems of the Antarctic are therefore largely dominated by lichens. The effects of global climate change are especially pronounced in the maritime Antarctic and it may be assumed that the lichen vegetation will profoundly change in the future. The genetic diversity of populations is closely correlated to their ability to adapt to changing environmental conditions and to their future evolutionary potential. In this study, we present evidence for low genetic diversity in Antarctic mycobiont and photobiont populations of the widespread lichen Cetraria aculeata. We compared between 110 and 219 DNA sequences from each of three gene loci for each symbiont. A total of 222 individuals from three Antarctic and nine antiboreal, temperate and Arctic populations were investigated. The mycobiont diversity is highest in Arctic populations, while the photobionts are most diverse in temperate regions. Photobiont diversity decreases significantly towards the Antarctic but less markedly towards the Arctic, indicating that ecological factors play a minor role in determining the diversity of Antarctic photobiont populations. Richness estimators calculated for the four geographical regions suggest that the low genetic diversity of Antarctic populations is not a sampling artefact. Cetraria aculeata appears to have diversified in the Arctic and subsequently expanded its range into the Southern Hemisphere. The reduced genetic diversity in the Antarctic is most likely due to founder effects during long-distance colonization.

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Dissolved barium has been shown to have the potential to distinguish Eurasian from North American (NA) river runoff. As part of the ARK-XXII/2 Polarstern expedition in summer 2007, Ba was analyzed in the Barents, Kara, Laptev seas, and the Eurasian Basins as well as the Makarov Basin up to the Alpha and Mendeleyev Ridges. By combining salinity, d18O and initial phosphate corrected for mineralization with oxygen (PO4*) or N/P ratios we identified the water mass fractions of meteoric water, sea ice meltwater, and marine waters of Atlantic as well as Pacific origin in the upper water column. In all basins inside the lower halocline layer and the Arctic intermediate waters we find Ba concentrations close to those of the Fram Strait branch of the lower halocline (41-45 nM), reflecting the composition of the incoming Atlantic water. A layer of upper halocline water (UHW) with higher Ba concentrations (45-55 nM) is identified in the Makarov Basin. Atop of the UHW, the Surface Mixed Layer (SML), including the summer and winter mixed layers, has high concentrations of Ba (58-67 nM). In the SML of the investigated area of the central Arctic the meteoric fraction can be identified by assuming a conservative behavior of Ba to be primarily of Eurasian river origin. However, in productive coastal regions biological removal compromises the use of Ba to distinguish between Eurasian and NA rivers. As a consequence, the NA river water fraction is underestimated in productive surface waters or waters that have passed a productive region, whereas this fraction is overestimated in subsurface waters containing remineralised Ba, particularly when these waters have passed productive shelf regions. Especially in the Laptev Sea and small regions in the Barents Sea, Ba concentrations are low in surface waters. In the Laptev Sea exceptionally high Ba concentrations in shelf bottom waters indicate that Ba is removed from surface waters to deep waters by biological activity enhanced by increasing ice-free conditions as well as by scavenging by organic matter of terrestrial origin. We interpret high Ba concentrations in the UHW of the Makarov Basin to result from enrichment by remineralisation in bottom waters on the shelf of the Chukchi Sea and therefore the calculated NA runoff is an artefact. We conclude that no NA runoff can be demonstrated unequivocally anywhere during our expedition with the set of tracers considered here. Small contributions of NA runoff may have been masked by Ba depletion and could only be resolved by supportive tracers on the uptake history. We thus suggest that Ba has to be used with care as it can put limits but not yield quantitative water mass distributions. Only if the extra Ba inputs exceed the cumulative biological uptake the signal can be unequivocally attributed to NA runoff.

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A large number of later Neolithic sites (3900–3500BC) in Switzerland, Southern Germany and Eastern France offer outstandingly well preserved archaeological materials from cultural layers. Due to the wide use of dendrochronology, settlement remains and artefact assemblages can now be placed into a precise and fixed chronological framework, thus presenting a unique case within prehistoric archaeology. In earlier research, chronological and regional units were constructed on the basis of pottery. These spacial and temporal units of typical pottery sets were understood as Neolithic cultures, as culturally more or less homogenous entities connected with (ethnic) identities. Today, with a larger data corpus of excavated settlements at hand, we can begin to understand that this period of the past was in fact characterised by a multitude of cultural entanglements and transformations. This is indicated by the occurrence of local and non-local pottery styles in one and the same settlement: for example typically local Cortaillod pottery is found together with NMB-styled pottery in settlements at Lake Neuchâtel or Michelsberg pottery is regularly occurring in settlements at Lake Constance where Pfyn pottery style is the typical local one. These and many more examples show that there must have been complex entanglements of social ties expanding between Eastern France, Southern Germany and the Swiss Plateau. Given these circumstances the former notions of Neolithic culture should be critically revised. Therefore, in late 2014, the Prehistoric Archaeology Department at the Archaeological Institute of University of Berne started a four-year research project funded by Swiss National Science Foundation in late 2014: ‘Mobilities, Entanglements and Transformations in Neolithic Societies of the Swiss Plateau (3900-3500 BC)’. It’s objective is to address the topic sketched above by adopting a mixed methods research (MMR)-design combining qualitative and quantitative approaches from archaeology and archaeometry. The approach is theoretically based on Pierre Bourdieu’s reflexive sociology and his concept of habitus but includes further concepts of practice theories. By shifting the focus to the movement of people, ideas and things – to pottery production practices in contexts of mobility – a deeper understanding of the transformative capacities of encounters can be achieved. This opens the path for new insights of Neolithic societies including social, cultural and economic dynamics that were underestimated in former research.

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DynaLearn (http://www.DynaLearn.eu) develops a cognitive artefact that engages learners in an active learning by modelling process to develop conceptual system knowledge. Learners create external representations using diagrams. The diagrams capture conceptual knowledge using the Garp3 Qualitative Reasoning (QR) formalism [2]. The expressions can be simulated, confronting learners with the logical consequences thereof. To further aid learners, DynaLearn employs a sequence of knowledge representations (Learning Spaces, LS), with increasing complexity in terms of the modelling ingredients a learner can use [1]. An online repository contains QR models created by experts/teachers and learners. The server runs semantic services [4] to generate feedback at the request of learners via the workbench. The feedback is communicated to the learner via a set of virtual characters, each having its own competence [3]. A specific feedback thus incorporates three aspects: content, character appearance, and a didactic setting (e.g. Quiz mode). In the interactive event we will demonstrate the latest achievements of the DynaLearn project. First, the 6 learning spaces for learners to work with. Second, the generation of feedback relevant to the individual needs of a learner using Semantic Web technology. Third, the verbalization of the feedback via different animated virtual characters, notably: Basic help, Critic, Recommender, Quizmaster & Teachable agen

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¿Qué son los TRAJES ESPACIALES? El término Trajes Espaciales da nombre al “equipo de inmersión” 1 necesario para garantizar las condiciones de habitabilidad en determinados entornos o circunstancias. En diferentes coyunturas sociales, políticas o ambientales el formato convencional de la arquitectura se vuelve limitado o poco eficaz. Determinadas configuraciones de “vida a la intemperie” 2, asociadas a necesidades de protección, energía, comunicación, socialización…, en situaciones de alta emancipación e itinerancia, solicitan una reflexión sobre la posible portabilidad, o más concretamente, sobre la idoneidad del uso 3 de las condiciones arquitectónicas. La tesis pretende acotar o definir un no reconocido ámbito de los recursos proyectuales del arquitecto dirigido a la confección de las más cercanas envolventes corporales entendidas como elementos arquitectónicos. Casa y vestimenta, citando a Marshall McLuhan, se identifican en un discurso que entiende ambas esferas como “extensiones de la piel” 4 que garantizan el control energético y la definición social del sujeto que las habita. En determinados momentos el arquitecto ha tenido que desestimar como principal herramienta de trabajo la construcción de edificios, para abordar ciertas demandas sociales. La tesis pretende demostrar cómo el diseño de trajes ha sido en ocasiones una estrategia proyectual del repertorio de la arquitectura. Su aportación es la de abordar el mundo de la vestimenta más allá del simple ejercicio estilístico, defendiendo estas construcciones como un elemento capaz de hacer habitable un determinado entorno. Este acercamiento ha permitido a los arquitectos ensayar en los trajes lo que posteriormente desarrollarían en sus edificios. Temas tratados por la arquitectura como higienismo, ornamento, estandarización, pliegue… han encontrado en la escala de la vestimenta su expresión más pura. El diseño de estos trajes, su pertinencia y su confección como parte del proyecto arquitectónico, conformará el hilo conductor de esta tesis. ABSTRACT The term spacesuits tries to define the “diving equipment” 5 necessary to ensure the living conditions in certain environments or circumstances. In specific social, political or environmental circumstances, the architectural standard format becomes limited or ineffective. Some configurations of “life outdoor” 6, associated with protection, energy, communication and socialization needs, in situations of high emancipation and roaming, seek a reflection on the possible portability, or more specifically, on the appropriateness of wearing the architectural features. The thesis aims to limit or define an unrecognized field from the resources of the architect focused on body emvelopes as architectural elements. House and clothing, quoting Marshall McLuhan, are matched in a speech that understand both spheres as “extensions of the skins” 7, to ensure energy control and social definition of the subject who inhabit them. At times, the architect has had to dismiss the construction of buildings as the main tool for working, to address certain social demands. The thesis aims to demonstrate how the costume design is sometimes a projectual strategy in the repertoire of architecture. Its contribution splits with Fashion as a mere stylistic exercise, defending the dress as an artefact capable of making livable a certain environment. This approach has allowed architects to explore at costumes what they develope in their buildings later. Topics covered by the architecture as hygienism, ornament, standardization, folding... have found in the scale of the dress its purest expression. The design of these suits, their techniques and their relevance as part of the architectural project, will form the core of this thesis.

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Las metodologías de desarrollo ágiles han sufrido un gran auge en entornos industriales durante los últimos años debido a la rapidez y fiabilidad de los procesos de desarrollo que proponen. La filosofía DevOps y específicamente las metodologías derivadas de ella como Continuous Delivery o Continuous Deployment promueven la gestión completamente automatizada del ciclo de vida de las aplicaciones, desde el código fuente a las aplicaciones ejecutándose en entornos de producción. La automatización se ve como un medio para producir procesos repetibles, fiables y rápidos. Sin embargo, no todas las partes de las metodologías Continuous están completamente automatizadas. En particular, la gestión de la configuración de los parámetros de ejecución es un problema que ha sido acrecentado por la elasticidad y escalabilidad que proporcionan las tecnologías de computación en la nube. La mayoría de las herramientas de despliegue actuales pueden automatizar el despliegue de la configuración de parámetros de ejecución, pero no ofrecen soporte a la hora de fijar esos parámetros o de validar los ficheros que despliegan, principalmente debido al gran abanico de opciones de configuración y el hecho de que el valor de muchos de esos parámetros es fijado en base a preferencias expresadas por el usuario. Esto hecho hace que pueda parecer que cualquier solución al problema debe estar ajustada a una aplicación específica en lugar de ofrecer una solución general. Con el objetivo de solucionar este problema, propongo un modelo de configuración que puede ser inferido a partir de instancias de configuración existentes y que puede reflejar las preferencias de los usuarios para ser usado para facilitar los procesos de configuración. El modelo de configuración puede ser usado como la base de un proceso de configuración interactivo capaz de guiar a un operador humano a través de la configuración de una aplicación para su despliegue en un entorno determinado o para detectar cambios de configuración automáticamente y producir una configuración válida que se ajuste a esos cambios. Además, el modelo de configuración debería ser gestionado como si se tratase de cualquier otro artefacto software y debería ser incorporado a las prácticas de gestión habituales. Por eso también propongo un modelo de gestión de servicios que incluya información relativa a la configuración de parámetros de ejecución y que además es capaz de describir y gestionar propuestas arquitectónicas actuales tales como los arquitecturas de microservicios. ABSTRACT Agile development methodologies have risen in popularity within the industry in recent years due to the speed and reliability of the processes they propose. The DevOps philosophy and specifically the methodologies derived from it such as Continuous Delivery and Continuous Deployment push for a totally automated management of the application lifecycle, from the source code to the software running in production environment. Automation in this regard is used as a means to produce repeatable, reliable and fast processes. However, not all parts of the Continuous methodologies are completely automatized. In particular, management of runtime parameter configuration is a problem that has increased its impact in deployment process due to the scalability and elasticity provided by cloud technologies. Most deployment tools nowadays can automate the deployment of runtime parameter configuration, but they offer no support for parameter setting o configuration validation, as the range of different configuration options and the fact that the value of many of those parameters is based on user preference seems to imply that any solution to the problem will have to be tailored to a specific application. With the aim to solve this problem I propose a configuration model that can be inferred from existing configurations and reflect user preferences in order to ease the configuration process. The configuration model can be used as the base of an interactive configuration process capable of guiding a human operator through the configuration of an application for its deployment in a specific environment or to automatically detect configuration changes and produce valid runtime parameter configurations that take into account those changes. Additionally, the configuration model should be managed as any other software artefact and should be incorporated into current management practices. I also propose a service management model that includes the configuration information and that is able to describe and manage current architectural practices such as the microservices architecture.