880 resultados para noninertial frames


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Paracoccidioides brasiliensis causes paracoccidioidomycosis (PCM), a systemic mycosis presenting clinical manifestations ranging from mild to severe forms. A P. brasiliensis cDNA expression library was produced and screened with pooled sera from PCM patients adsorbed against antigens derived from in vitro-grown P. brasiliensis yeast cells. Sequencing DNA inserts from clones reactive with PCM patients sera indicated 35 open reading frames presenting homology to genes involved in metabolic pathways, transport, among other predicted functions. The complete cDNAs encoding aromatic-L-amino-acid decarboxylase (Pbddc), lumazine synthase (Pbls) and a homologue of the high affinity copper transporter (Pbctr3) were obtained. Recombinant proteins PbDDC and PbLS were obtained; a peptide was synthesized for PbCTR3. The proteins and the synthetic peptide were recognized by sera of patients with confirmed PCM and not by sera of healthy patients. Using the in vivo-induced antigen technology (IVIAT), we identified immunogenic proteins expressed at high levels during infection. Quantitative real time RTPCR demonstrated high transcript levels of Pbddc, Pbls and Pbctr3 in yeast cells infecting macrophages. Transcripts in yeast cells derived from spleen and liver of infected mice were also measured by qRT-PCR. Our results suggest a putative role for the immunogenic proteins in the infectious process of P. brasiliensis. (C) 2009 Elsevier Masson SAS. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The literature reports research efforts allowing the editing of interactive TV multimedia documents by end-users. In this article we propose complementary contributions relative to end-user generated interactive video, video tagging, and collaboration. In earlier work we proposed the watch-and-comment (WaC) paradigm as the seamless capture of an individual`s comments so that corresponding annotated interactive videos be automatically generated. As a proof of concept, we implemented a prototype application, the WACTOOL, that supports the capture of digital ink and voice comments over individual frames and segments of the video, producing a declarative document that specifies both: different media stream structure and synchronization. In this article, we extend the WaC paradigm in two ways. First, user-video interactions are associated with edit commands and digital ink operations. Second, focusing on collaboration and distribution issues, we employ annotations as simple containers for context information by using them as tags in order to organize, store and distribute information in a P2P-based multimedia capture platform. We highlight the design principles of the watch-and-comment paradigm, and demonstrate related results including the current version of the WACTOOL and its architecture. We also illustrate how an interactive video produced by the WACTOOL can be rendered in an interactive video environment, the Ginga-NCL player, and include results from a preliminary evaluation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper proposes a parallel hardware architecture for image feature detection based on the Scale Invariant Feature Transform algorithm and applied to the Simultaneous Localization And Mapping problem. The work also proposes specific hardware optimizations considered fundamental to embed such a robotic control system on-a-chip. The proposed architecture is completely stand-alone; it reads the input data directly from a CMOS image sensor and provides the results via a field-programmable gate array coupled to an embedded processor. The results may either be used directly in an on-chip application or accessed through an Ethernet connection. The system is able to detect features up to 30 frames per second (320 x 240 pixels) and has accuracy similar to a PC-based implementation. The achieved system performance is at least one order of magnitude better than a PC-based solution, a result achieved by investigating the impact of several hardware-orientated optimizations oil performance, area and accuracy.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We propose an approach to the quantum-mechanical description of relativistic orientable objects. It generalizes Wigner`s ideas concerning the treatment of nonrelativistic orientable objects (in particular, a nonrelativistic rotator) with the help of two reference frames (space-fixed and body-fixed). A technical realization of this generalization (for instance, in 3+1 dimensions) amounts to introducing wave functions that depend on elements of the Poincar, group G. A complete set of transformations that test the symmetries of an orientable object and of the embedding space belongs to the group I =GxG. All such transformations can be studied by considering a generalized regular representation of G in the space of scalar functions on the group, f(x,z), that depend on the Minkowski space points xaG/Spin(3,1) as well as on the orientation variables given by the elements z of a matrix ZaSpin(3,1). In particular, the field f(x,z) is a generating function of the usual spin-tensor multi-component fields. In the theory under consideration, there are four different types of spinors, and an orientable object is characterized by ten quantum numbers. We study the corresponding relativistic wave equations and their symmetry properties.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We provide a characterization of the Clifford Torus in S(3) via moving frames and contact structure equations. More precisely, we prove that minimal surfaces in S(3) with constant contact angle must be the Clifford Torus. Some applications of this result are then given, and some examples are discussed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Transcription factors (TFs) are major players in gene regulatory networks and interactions between TFs and their target genes furnish spatiotemporal patterns of gene expression. Establishing the architecture of regulatory networks requires gathering information on TFs, their targets in the genome, and the corresponding binding sites. We have developed GRASSIUS (Grass Regulatory Information Services) as a knowledge-based Web resource that integrates information on TFs and gene promoters across the grasses. In its initial implementation, GRASSIUS consists of two separate, yet linked, databases. GrassTFDB holds information on TFs from maize (Zea mays), sorghum (Sorghum bicolor), sugarcane (Saccharum spp.), and rice (Oryza sativa). TFs are classified into families and phylogenetic relationships begin to uncover orthologous relationships among the participating species. This database also provides a centralized clearinghouse for TF synonyms in the grasses. GrassTFDB is linked to the grass TFome collection, which provides clones in recombination-based vectors corresponding to full-length open reading frames for a growing number of grass TFs. GrassPROMDB contains promoter and cis-regulatory element information for those grass species and genes for which enough data are available. The integration of GrassTFDB and GrassPROMDB will be accomplished through GrassRegNet as a first step in representing the architecture of grass regulatory networks. GRASSIUS can be accessed from www.grassius.org.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Incomplete and/or sluggish maltotriose fermentation causes both quality and economic problems in the ale-brewing industry. Although it has been proposed previously that the sugar uptake must be responsible for these undesirable phenotypes, there have been conflicting reports on whether all the known alpha-glucoside transporters in Saccharomyces cerevisiae (MALx1, AGT1, and MPH2 and MPH3 transporters) allow efficient maltotriose utilization by yeast cells. We characterized the kinetics of yeast cell growth, sugar consumption, and ethanol production during maltose or maltotriose utilization by several S. cerevisiae yeast strains (both MAL constitutive and AM inducible) and by their isogenic counterparts with specific deletions of the AGT1 gene. Our results clearly showed that yeast strains carrying functional permeases encoded by the MAL21, MAL31, and/or MAL41 gene in their plasma membranes were unable to utilize maltotriose. While both high-and low-affinity transport activities were responsible for maltose uptake from the medium, in the case of maltotriose, the only low-affinity (K-m, 36 +/- 2 mM) transport activity was mediated by the AGT1 permease. In conclusion, the AGT1 transporter is required for efficient maltotriose fermentation by S. cerevisiae yeasts, highlighting the importance of this permease for breeding and/or selection programs aimed at improving sluggish maltotriose fermentations.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This master’s thesis deals with the cultural diversity policies of Denmark and Sweden within the cultural sector. It attempts at explaining why these two “most-similar” scandinavian countries having in common the same cultural model, “the architect model”, opted for different policies when it came to cultural diversity: Assimilationism for Denmark and multiculturalism for Sweden. I show that though institutional and power-interest factors had an impact, ideas as “programmatic beliefs” (Sheri E. Berman 2001) or “frames” (Erik Bleich 2003) played the ultimate role. I evaluate their relative importance by analyzing the anthropological dimension of the countries cultural policies since 1969. The study confirms that at least in the cultural sector, Danish policies have been assimilationist and Swedish ones multiculturalist and proposes a new classification of terms.By investigating immigrants cultures, it fills a gap left by previous researchers working on a common Nordic cultural model.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Literacy Practices in Upper Secondary School. The Writing of Construction and Health CarePupilsThe aim of the dissertation is to demonstrate and explain the place and function writing has in allsubjects in two vocational classes in a Swedish upper secondary school. The material has beencollected through ethnographic field studies in construction and health care classes over one schoolyear. The material consists of literacy events, where pupils write, and the context of situation andtext are noted.In theoretical terms the study takes a discourse analysis perspective, where writing is seen fromwithin different frames. Writing is analysed based on an ideological view of literacy inspired byNew Literacy Studies using the context of situation and text with the aim of describing differentliteracy practices in both classes.The material was classified into three different situation types, two school-initiated and one nonschool-initiated. The first school-initiated situation type is orally-governed, the second writinggoverned,while it is less clear how the non-school-initiated type is inspired.In the writing situations we investigate the writing activities that are used, while texts areanalysed based on text acitivites. Writing and text activities are used together to explain the writingcompetences that are used in the writing situations.The conclusions are that writing gets little space and attention in both classes. The healthcare class writes in more situations and also writes longer texts than the construction class.Literacy practices differ between the classes. The health care class demonstrates one schoolgovernedwriting practice, while the construction class moves between two different schoolgovernedpractices. The literacy practices in the construction class are similar to the writing usagethat can be found at a building site. Writing is used in both classes mainly to structure and storeknowledge.The non-school-governed material also shows differences between the classes. Here too morewriting takes place in the health care class. The function of the non-school-governed writing is tocommunicate and inform through writing.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The complexity of learning implies that learning seldom is about just one thing. It can be said that learning processes are interdisciplinary. Within educational contexts, learning is not limited to constructed school subjects. In drama education, learning is simultaneously about drama as aesthetic expression and content because drama always is about something. The mainly focus can be on form, content or social aspects. The different aspects are always present, but may be more or less foreground or the background depending on the purpose of education. How do development concerning understanding of form, content, and social interaction, interact in a learning process in drama? My research is based on the view that learning at the same time takes place as an individual, internal process and a socially situated, inter-subjective process. Can learning in drama imply learning that can be transferred between different situations, a transformative learning and if so, how? Transformative learning includes cognitive, affective and corporal and social action aspects and means that the individual's frames of reference are transformed, evolved, to become more insightful and flexible which implies a change of personality. It leads to an integrated knowledge that can be applied in different contexts.   In the paper that will be presented at the conference, theories about how we learn in drama will be discussed in relation to my empirical research concerning drama and learning.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: Previous assessment methods for PG recognition used sensor mechanisms for PG that may cause discomfort. In order to avoid stress of applying wearable sensors, computer vision (CV) based diagnostic systems for PG recognition have been proposed. Main constraints in these methods are the laboratory setup procedures: Novel colored dresses for the patients were specifically designed to segment the test body from a specific colored background. Objective: To develop an image processing tool for home-assessment of Parkinson Gait(PG) by analyzing motion cues extracted during the gait cycles. Methods: The system is based on the idea that a normal body attains equilibrium during the gait by aligning the body posture with the axis of gravity. Due to the rigidity in muscular tone, persons with PD fail to align their bodies with the axis of gravity. The leaned posture of PD patients appears to fall forward. Whereas a normal posture exhibits a constant erect posture throughout the gait. Patients with PD walk with shortened stride angle (less than 15 degrees on average) with high variability in the stride frequency. Whereas a normal gait exhibits a constant stride frequency with an average stride angle of 45 degrees. In order to analyze PG, levodopa-responsive patients and normal controls were videotaped with several gait cycles. First, the test body is segmented in each frame of the gait video based on the pixel contrast from the background to form a silhouette. Next, the center of gravity of this silhouette is calculated. This silhouette is further skeletonized from the video frames to extract the motion cues. Two motion cues were stride frequency based on the cyclic leg motion and the lean frequency based on the angle between the leaned torso tangent and the axis of gravity. The differences in the peaks in stride and lean frequencies between PG and normal gait are calculated using Cosine Similarity measurements. Results: High cosine dissimilarity was observed in the stride and lean frequencies between PG and normal gait. High variations are found in the stride intervals of PG whereas constant stride intervals are found in the normal gait. Conclusions: We propose an algorithm as a source to eliminate laboratory constraints and discomfort during PG analysis. Installing this tool in a home computer with a webcam allows assessment of gait in the home environment.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

En deskriptiv visuell innehållsanalys genomfördes med en korpus bestående av vetenskapliga artiklar från 30 topprankade tidskrifter jämnt fördelade på de tre disciplinerna matematik, medicin och utbildningsvetenskap, med syfte att undersöka om det fanns ett samband mellan tidskrifternas disciplintillhörighet och den grafiska formgivningen. Kartläggningen omfattade layout (bl.a. sidformat, spalter, marginalstorlek, användning av grafiska element, placering av tabeller, figurer och pagina) och typografiskt utseende hos titel, rubriker, brödtext och abstrakt (t.ex. teckenstorlek, textjustering, teckengrovlek, typsnitt, färg och radavstånd). Resultaten visar att disciplinerna använde olika men även gemensamma konventioner i sitt grafiska utseende. Matematik uppvisade enkelspaltig layout med liten typografisk variation, genomgående användning av typsnitt från familjen Transitional eller Transitional/Didone för hela dokumentet, avsaknad av kulört färg och sällan användning av grafiska element. Medicin uppvisade större variation med användning av kulört färg, icke-centrerad typografi med både sansseriff- och seriff-typsnitt, grafiska element och ramar som förstärker det ofta använda dubbelspaltiga gridsystemet. Utbildningsvetenskap uppvisade en grafisk design som återfanns i båda disciplinerna, men påminde mest om matematik till utseendet. Kodbok ingår i sin helhet som bilaga. Uppsatsen i sig är delvis formgiven med utgångspunkt i de erhållna resultaten.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Wooden railway sleeper inspections in Sweden are currently performed manually by a human operator; such inspections are based on visual analysis. Machine vision based approach has been done to emulate the visual abilities of human operator to enable automation of the process. Through this process bad sleepers are identified, and a spot is marked on it with specific color (blue in the current case) on the rail so that the maintenance operators are able to identify the spot and replace the sleeper. The motive of this thesis is to help the operators to identify those sleepers which are marked by color (spots), using an “Intelligent Vehicle” which is capable of running on the track. Capturing video while running on the track and segmenting the object of interest (spot) through this vehicle; we can automate this work and minimize the human intuitions. The video acquisition process depends on camera position and source light to obtain fine brightness in acquisition, we have tested 4 different types of combinations (camera position and source light) here to record the video and test the validity of proposed method. A sequence of real time rail frames are extracted from these videos and further processing (depending upon the data acquisition process) is done to identify the spots. After identification of spot each frame is divided in to 9 regions to know the particular region where the spot lies to avoid overlapping with noise, and so on. The proposed method will generate the information regarding in which region the spot lies, based on nine regions in each frame. From the generated results we have made some classification regarding data collection techniques, efficiency, time and speed. In this report, extensive experiments using image sequences from particular camera are reported and the experiments were done using intelligent vehicle as well as test vehicle and the results shows that we have achieved 95% success in identifying the spots when we use video as it is, in other method were we can skip some frames in pre-processing to increase the speed of video but the segmentation results we reduced to 85% and the time was very less compared to previous one. This shows the validity of proposed method in identification of spots lying on wooden railway sleepers where we can compromise between time and efficiency to get the desired result.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This licentiate thesis sets out to analyse how a retail price decision frame can be understood. It is argued that it is possible to view price determination within retailing by determining the level of rationality and using behavioural theories. In this way, it is possible to use assumptions derived from economics and marketing to establish a decision frame. By taking a management perspective, it is possible to take into consideration how it is assumed that the retailer should strategically manage price decisions, which decisions might be assumed to be price decisions, and which decisions can be assumed to be under the control of the retailer. Theoretically, this licentiate thesis has its foundations in different assumptions about decision frames regarding the level of information collected, the goal of the decisions, and the outcomes of the decisions. Since the concepts that are to be analysed within this thesis are price decisions, the latter part of the theory discusses price decision in specific: sequential price decisions, at the point of the decision, and trade-offs when making a decision. Here, it is evident that a conceptual decision frame that is intended to illustrate price decisions includes several aspects: several decision alternatives and what assumptions of rationality that can be made in relation to the decision frame. A semi-structured literature review was conducted. As a result, it became apparent that two important things in the decision frame were unclear: time assumptions regarding the decisions and the amount of information that is assumed in relation to the different decision alternatives. By using the same articles that were used to adjust the decision frame, a topical study was made in order to determine the time specific assumptions, as well as the analytical level based on the assumed information necessary for individual decision alternatives. This, together with an experimental study, was necessary to be able to discuss the consequences of the rationality assumption. When the retail literature is analysed for the level of rationality and consequences of assuming certain assumptions of rationality, three main things becomes apparent. First, the level of rationality or the assumptions of rationality are seldom made or accounted for in the literature. In fact, there are indications that perfect and bounded rationality assumptions are used simultaneously within studies. Second, although bounded rationality is a recognised theoretical perspective, very few articles seem to use these assumptions. Third, since the outcome of a price decision seems to provide no incremental sale, it is questionable which assumptions of rationality that should be used. It might even be the case that no assumptions of rationality at all should be used. In a broader perspective, the findings from this licentiate thesis show that the assumptions of rationality within retail research is unclear. There is an imbalance between the perspectives used, where the main assumptions seem to be concentrated to perfect rationality. However, it is suggested that by clarifying which assumptions of rationality that is used and using bounded rationality assumptions within research would result in a clearer picture of the multifaceted price decisions that could be assumed within retailing. The theoretical contribution of this thesis mainly surround the identification of how the level of rationality provides limiting assumptions within retail research. Furthermore, since indications show that learning might not occur within this specific context it is questioned whether the basic learning assumption within bounded rationality should be used in this context.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A main purpose of this paper is to propose to policy makers, building professionals, and other non-social scientists a way to make energy interventions more culturally informed and, thereby, more effective. The case study on house purchasers gives an ample illustration of the richer results that can be achieved by paying attention to three aspects of energy efficiency initiatives: the contexts and situations of choice in each particular case, the interaction among relevant social actors, and the culture-specific preconditions for choice. Research on how purchasers of new pre-fabricated houses in Sweden choose their heating system show how such decisions tend to fall between two stools. Furthermore, the organizational structure of housing companies frames house purchasers' decision making. An important result is that energy saving or conversion measures must be promoted at an early stage amongst those who plan and construct buildings (rather than later amongst dwellers and energy end users).