996 resultados para Complex Signals
Resumo:
There are many known examples of multiple semi-independent associations at individual loci; such associations might arise either because of true allelic heterogeneity or because of imperfect tagging of an unobserved causal variant. This phenomenon is of great importance in monogenic traits but has not yet been systematically investigated and quantified in complex-trait genome-wide association studies (GWASs). Here, we describe a multi-SNP association method that estimates the effect of loci harboring multiple association signals by using GWAS summary statistics. Applying the method to a large anthropometric GWAS meta-analysis (from the Genetic Investigation of Anthropometric Traits consortium study), we show that for height, body mass index (BMI), and waist-to-hip ratio (WHR), 3%, 2%, and 1%, respectively, of additional phenotypic variance can be explained on top of the previously reported 10% (height), 1.5% (BMI), and 1% (WHR). The method also permitted a substantial increase (by up to 50%) in the number of loci that replicate in a discovery-validation design. Specifically, we identified 74 loci at which the multi-SNP, a linear combination of SNPs, explains significantly more variance than does the best individual SNP. A detailed analysis of multi-SNPs shows that most of the additional variability explained is derived from SNPs that are not in linkage disequilibrium with the lead SNP, suggesting a major contribution of allelic heterogeneity to the missing heritability.
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OBJECTIVE: To emphasize that complex regional pain syndrome (CRPS), a disabling disorder with the implication of aberrant inflammation, vasomotor dysfunction, and maladaptive neuroplasticity, might be treated with a high dose of intravenous immunoglobulin infusions (IVIG). METHODS: We describe a patient who presented with CRPS in the acute phase of the disease. RESULTS: The CRPS developed secondary to sciatic compression in a young patient and was treated within 10 days by high-dose IVIG (2 g/kg). It resolved completely within days after infusions. DISCUSSION: This observational study emphasizes that high-dose IVIG may be a treatment option in the acute phase of CRPS.
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Background: oscillatory activity, which can be separated in background and oscillatory burst pattern activities, is supposed to be representative of local synchronies of neural assemblies. Oscillatory burst events should consequently play a specific functional role, distinct from background EEG activity – especially for cognitive tasks (e.g. working memory tasks), binding mechanisms and perceptual dynamics (e.g. visual binding), or in clinical contexts (e.g. effects of brain disorders). However extracting oscillatory events in single trials, with a reliable and consistent method, is not a simple task. Results: in this work we propose a user-friendly stand-alone toolbox, which models in a reasonable time a bump time-frequency model from the wavelet representations of a set of signals. The software is provided with a Matlab toolbox which can compute wavelet representations before calling automatically the stand-alone application. Conclusion: The tool is publicly available as a freeware at the address: http:// www.bsp.brain.riken.jp/bumptoolbox/toolbox_home.html
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The Learning Affect Monitor (LAM) is a new computer-based assessment system integrating basic dimensional evaluation and discrete description of affective states in daily life, based on an autonomous adapting system. Subjects evaluate their affective states according to a tridimensional space (valence and activation circumplex as well as global intensity) and then qualify it using up to 30 adjective descriptors chosen from a list. The system gradually adapts to the user, enabling the affect descriptors it presents to be increasingly relevant. An initial study with 51 subjects, using a 1 week time-sampling with 8 to 10 randomized signals per day, produced n = 2,813 records with good reliability measures (e.g., response rate of 88.8%, mean split-half reliability of .86), user acceptance, and usability. Multilevel analyses show circadian and hebdomadal patterns, and significant individual and situational variance components of the basic dimension evaluations. Validity analyses indicate sound assignment of qualitative affect descriptors in the bidimensional semantic space according to the circumplex model of basic affect dimensions. The LAM assessment module can be implemented on different platforms (palm, desk, mobile phone) and provides very rapid and meaningful data collection, preserving complex and interindividually comparable information in the domain of emotion and well-being.
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Intrathymic T-cell maturation critically depends on the selective expansion of thymocytes expressing a functionally rearranged T-cell receptor (TCR) beta chain. In addition, TCR-independent signals also contribute to normal T-cell development. It is unclear whether and how signals from the 2 types of pathways are integrated. Here, we show that T-cell factor-1 (TCF-1), a nuclear effector of the canonical wingless/int (wnt)/catenin signaling pathway, ensures the survival of proliferating, pre-TCR(+) thymocytes. The survival of pre-TCR(+) thymocytes requires the presence of the N-terminal catenin-binding domain in TCF-1. This domain can bind the transcriptional coactivator beta-catenin and may also bind gamma-catenin (plakoglobin). However, in the absence of gamma-catenin, T-cell development is normal, supporting a role for beta-catenin. Signaling competent beta-catenin is present prior to and thus arises independently from pre-TCR signaling and does not substantially increase on pre-TCR signaling. In contrast, pre-TCR signaling significantly induces TCF-1 expression. This coincides with the activation of a wnt/catenin/TCF reporter transgene in vivo. Collectively, these data suggest that efficient TCF-dependent transcription requires that pre-TCR signaling induces TCF-1 expression, whereas wnt signals may provide the coactivator such as beta-catenin. The 2 pathways thus have to cooperate to ensure thymocyte survival at the pre-TCR stage.
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25 patients with acute myocardial infarction pain lasting more than 20 minutes which was not relieved by nitrates, whose ECGs showed ST segment elevations of 1 mm or more in 2 or more ECG leads, and who presented less than 3 hours after onset of their symptoms were randomly assigned to one of 2 thrombolytic treatment groups: a single intravenous bolus of anisoylated plasminogen streptokinase activator complex (APSAC) 30U in 5 minutes or an intravenous infusion of streptokinase 1,500,000U over 60 minutes. 3 to 4 hours after the administration of the thrombolytic agent, all patients received intravenous heparin at full dosage for 24 hours. The patency of the infarct-related coronary vessels was assessed by angiography 1 to 4 hours after administration of the thrombolytic agent. Clinical signs, ECGs, pulse, blood pressure and temperature were monitored regularly for 24 hours after treatment or as clinically appropriate. APSAC seemed to be at least as effective as streptokinase in terms of patency of the infarct-related vessel (92% vs 63%, respectively). The adverse events were similar and none was life-threatening. APSAC and streptokinase caused similar falls in blood fibrinogen levels. APSAC, given as a bolus injection over 5 minutes, was easier to administer than streptokinase, which was given as an infusion during 60 minutes.
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When dealing with nonlinear blind processing algorithms (deconvolution or post-nonlinear source separation), complex mathematical estimations must be done giving as a result very slow algorithms. This is the case, for example, in speech processing, spike signals deconvolution or microarray data analysis. In this paper, we propose a simple method to reduce computational time for the inversion of Wiener systems or the separation of post-nonlinear mixtures, by using a linear approximation in a minimum mutual information algorithm. Simulation results demonstrate that linear spline interpolation is fast and accurate, obtaining very good results (similar to those obtained without approximation) while computational time is dramatically decreased. On the other hand, cubic spline interpolation also obtains similar good results, but due to its intrinsic complexity, the global algorithm is much more slow and hence not useful for our purpose.
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In this paper we present a method for blind deconvolution of linear channels based on source separation techniques, for real word signals. This technique applied to blind deconvolution problems is based in exploiting not the spatial independence between signals but the temporal independence between samples of the signal. Our objective is to minimize the mutual information between samples of the output in order to retrieve the original signal. In order to make use of use this idea the input signal must be a non-Gaussian i.i.d. signal. Because most real world signals do not have this i.i.d. nature, we will need to preprocess the original signal before the transmission into the channel. Likewise we should assure that the transmitted signal has non-Gaussian statistics in order to achieve the correct function of the algorithm. The strategy used for this preprocessing will be presented in this paper. If the receiver has the inverse of the preprocess, the original signal can be reconstructed without the convolutive distortion.
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In this paper we present a quantitative comparisons of different independent component analysis (ICA) algorithms in order to investigate their potential use in preprocessing (such as noise reduction and feature extraction) the electroencephalogram (EEG) data for early detection of Alzhemier disease (AD) or discrimination between AD (or mild cognitive impairment, MCI) and age-match control subjects.
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It has been suggested that determination of the neutrophil elastase alpha1-proteinase inhibitor complex (E-alpha1PI) improves the diagnosis of bacterial infection in newborns. We evaluated the use of E-alpha1PI measurements in 143 newborns, consecutively admitted to a tertiary intensive care unit, employing a new random access assay and a sampling procedure that minimises post-collection artefacts. The 95% range for noninfected newborns was 20-110 microg/l up to the 5th day of life and 20-85 microg/l thereafter. The sensitivity as to the diagnosis of culture-proven bloodstream infection was 80% for E-alpha1PI, 86% for the immature to total neutrophil ratio, 64% for C-reactive protein and 37% for the total white blood cell count. The corresponding specificity amounted to 97%, 85%, 85% and 86%, respectively. E-alpha1PI increases preceded elevations of C-reactive protein by 18 h. Like C-reactive protein, E-alpha1PI levels did not distinguish between bloodstream infection and non-bacterial inflammatory responses. Results of E-alpha1PI became available within 1 h of collection and usually 2-3 h before manual leucocyte counts. CONCLUSION: Determination of neutrophil elastase alpha1-proteinase inhibitor levels yields diagnostic advantages comparable to those of manual differential counts but provide faster turnaround times.
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The orchestration of collaborative learning processes in face-to-facephysical settings, such as classrooms, requires teachers to coordinate students indicating them who belong to each group, which collaboration areas areassigned to each group, and how they should distribute the resources or roles within the group. In this paper we present an Orchestration Signal system,composed of wearable Personal Signal devices and an Orchestration Signal manager. Teachers can configure color signals in the manager so that they are transmitted to the wearable devices to indicate different orchestration aspects.In particular, the paper describes how the system has been used to carry out a Jigsaw collaborative learning flow in a classroom where students received signals indicating which documents they should read, in which group they were and in which area of the classroom they were expected to collaborate. The evaluation results show that the proposed system facilitates a dynamic, visual and flexible orchestration.
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A significant number of environmental microorganisms can cause serious, even fatal, acute and chronic infections in humans. The severity and outcome of each type of infection depends on the expression of specific bacterial phenotypes controlled by complex regulatory networks that sense and respond to the host environment. Although bacterial signals that contribute to a successful acute infection have been identified in a number of pathogens, the signals that mediate the onset and establishment of chronic infections have yet to be discovered. We identified a volatile, low molecular weight molecule, 2-amino acetophenone (2-AA), produced by the opportunistic human pathogen Pseudomonas aeruginosa that reduces bacterial virulence in vivo in flies and in an acute mouse infection model. 2-AA modulates the activity of the virulence regulator MvfR (multiple virulence factor regulator) via a negative feedback loop and it promotes the emergence of P. aeruginosa phenotypes that likely promote chronic lung infections, including accumulation of lasR mutants, long-term survival at stationary phase, and persistence in a Drosophila infection model. We report for the first time the existence of a quorum sensing (QS) regulated volatile molecule that induces bistability phenotype by stochastically silencing acute virulence functions in P. aeruginosa. We propose that 2-AA mediates changes in a subpopulation of cells that facilitate the exploitation of dynamic host environments and promote gene expression changes that favor chronic infections.
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Les basíliques paleocristianes del suburbi occidental de Tarraco. El temple septentrional i el complex martirial de Sant Fructuós és el resultat de 10 anys d’investigació desenvolupada al voltant del sector septentrional del Conjunt Paleocristià del Francolí, originada arran de les excavacions efectuades entre els anys 1994 i 1997 a la zona on actualment s’ubica el Parc Central. L’extraordinària importància del jaciment va despertar de seguida l’interès de l’autor, Jordi López, i de la comunitat científica, tant pel valor mateix de les restes com per la seva relació amb l’extensa necròpolis paleocristiana que al llarg de diverses campanyes havia excavat el Dr. Mn. Joan Serra i Vilaró. Es tracta d’una presentació de les últimes investigacions desenvolupades a l’ampli conjunt funerari i cristià del Francolí, al suburbium occidental de Tarraco. Consta de dos volums. El primer està estructurat en tres grans parts. Primerament, la presentació dels resultats dels treballs d’excavació duts a terme entre els anys 1994 i 1997 al sector septentrional del centre de culte cristià del Francolí, que inclou un estudi arquitectònic exhaustiu de la nova basílica excavada. En segon lloc, una revisió de les diferents intervencions desenvolupades en el sector meridional a principi de segle XX per Mn. Serra Vilaró i dels treballs dels anys 70 de M. D. del Amo, amb la proposta d’una nova interpretació arquitectònica de l’antiga basílica i de l’edifici situat al sud d’aquesta. I, finalment, una exposició general de l’evolució d’aquest sector occidental del suburbium de la ciutat, que reflecteix un especial dinamisme entre els segles IV i V dC, moment de màxima expansió de les grans àrees funeràries del segle III dC i de la monumentalització d’un gran centre de culte martirial al Francolí. El text està il·lustrat amb una àmplia documentació gràfica (plantes, seccions, fotografia, reconstruccions tridimensionals). A més, inclou 22 pàgines de conclusions amb la corresponent traducció a l’anglès. El segon volum conté set annexos específics: la relació d’unitats estratigràfiques, un inventari de materials, la descripció dels sepulcres, l’estudi osteoarqueològic i paleopatològic de les restes humanes, una anàlisi epigràfica, una de numismàtica i una última d’escultòrica.
Resumo:
PURPOSE: The aim of this study was to develop models based on kernel regression and probability estimation in order to predict and map IRC in Switzerland by taking into account all of the following: architectural factors, spatial relationships between the measurements, as well as geological information. METHODS: We looked at about 240,000 IRC measurements carried out in about 150,000 houses. As predictor variables we included: building type, foundation type, year of construction, detector type, geographical coordinates, altitude, temperature and lithology into the kernel estimation models. We developed predictive maps as well as a map of the local probability to exceed 300 Bq/m(3). Additionally, we developed a map of a confidence index in order to estimate the reliability of the probability map. RESULTS: Our models were able to explain 28% of the variations of IRC data. All variables added information to the model. The model estimation revealed a bandwidth for each variable, making it possible to characterize the influence of each variable on the IRC estimation. Furthermore, we assessed the mapping characteristics of kernel estimation overall as well as by municipality. Overall, our model reproduces spatial IRC patterns which were already obtained earlier. On the municipal level, we could show that our model accounts well for IRC trends within municipal boundaries. Finally, we found that different building characteristics result in different IRC maps. Maps corresponding to detached houses with concrete foundations indicate systematically smaller IRC than maps corresponding to farms with earth foundation. CONCLUSIONS: IRC mapping based on kernel estimation is a powerful tool to predict and analyze IRC on a large-scale as well as on a local level. This approach enables to develop tailor-made maps for different architectural elements and measurement conditions and to account at the same time for geological information and spatial relations between IRC measurements.