211 resultados para Localization. eng


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Language deficits are frequently reported in studies of patients with schizophrenia. The present study sought to test the hypothesis that such deficits are related to callosal function in this group. The FAS test of verbal fluency and Perin's Spoonerisms test of phonological processing were the tests of language. Callosal function was assessed using a Crossed Finger Localisation Test (CFLT), which is a measure of the interhemispheric transfer of somatosensory information. Patients with schizophrenia performed less well than controls on measures of language function. as well as on the CFLT. Significant positive correlations between CFLT performance and language function were present in the patient group, but not the control group. These findings extend on previous studies that report functional abnormalities of the corpus callosum in schizophrenia and are consistent with the hypothesis that language deficits in schizophrenia are related to impaired callosal functioning in this group. However, other explanations cannot be ruled Out.

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We report that subwavelength localization of light in the near-field of a double-periodic photonic metamaterial may be efficiently controlled by the polarization and wavelength of the incident radiation. A dramatic variation in the periodic near-field landscapes, including a transition from a pattern of isolated subwavelength plasmon hot-spots to a blurred, low contrast pattern, accompanied by a change in the pattern's symmetry has been observed in the proximity of an aluminum nanowire "fish-scale" nanostructure. Hot-spots as small as 0.23 lambda have been achieved and their position has been controlled by tuning the wavelength of incident light across the dipole absorption resonance of the metamaterial. A simple switch of the polarization state can lead to a spatial period doubling in the landscape pattern.

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A series of monoclonal antibodies was prepared against tegumental and internal antigens of Fasciola hepatica by immunizing mice with whole adult-fluke homogenates prior to harvesting the splenic lymphocytes for fusion. Preliminary screening by the Indirect Fluorescent Antibody technique indicated the occurrence of discrete groups of monoclonals differing from one another in tissue-specificity but within which IFA labelling patterns were fairly consistent. Representative hybridomas for 5 of these groups were stabilized and used to produce ascites fluid in mice. By application of an immunogold labelling technique it was possible to map the distribution of antigens for which each monoclonal antibody had affinity throughout the tissues of 4-week and 12-week flukes. Several monoclonals specifically labelled antigenic determinants on the important tegumental antigen T1. However the distribution of gold colloid labelling suggested that epitopes other than that normally exposed to the infected host were recognized; and several monoclonals specifically attached to T1 antigen in the tegument of juvenile worms only. The glycocalyx of the gut and excretory system of flukes shared T1 antigenicity with the tegument. Monoclonal antibodies were produced against an internal immunogen associated with ribosomes and heterochromatin in active protein-producing cells, and against interstitial material of adult flukes. Monoclonals against antigens in parenchymal cell cytoplasm and in mature vitelline cells were recognized but the corresponding hybridomas were not stabilized.

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The localisation and distribution of the cytoskeletal protein tubulin in the adult liver fluke Fasciola hepatica have been determined by an indirect immunofluorescence technique using a monoclonal antibody raised against beta-tubulin. Tubulin was demonstrated in the tegumental syncytium and in the tegumental cell bodies and their cytoplasmic connections with the surface syncytium. Immunostaining was also evident in the nerve fibres innervating sensory receptors in the tegument, in the nerve plexus innervating the sub-tegumental musculature and in the cytoplasmic extensions of the nurse cells within the vitelline follicle. Immunoblotting of whole fluke fractions produced a single band corresponding to a molecule of approximately 54 kDa in size. This figure corresponds with previous data obtained on tubulin from other helminth and eukaryotic sources.

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Research into localization has produced a wealth of algorithms and techniques to estimate the location of wireless network nodes, however the majority of these schemes do not explicitly account for non-line of sight conditions. Disregarding this common situation reduces their accuracy and their potential for exploitation in real world applications. This is a particular problem for personnel tracking where the user's body itself will inherently cause time-varying blocking according to their movements. Using empirical data, this paper demonstrates that, by accounting for non-line of sight conditions and using received signal strength based Monte Carlo localization, meter scale accuracy can be achieved for a wrist-worn personnel tracking tag in a 120 m indoor office environment. © 2012 IEEE.

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Processing of the 'CaaX' motif found on the C-termini of many proteins, including the proto-oncogene Ras, requires the ER (endoplasmic reticulum)-resident protease RCE1 (Ras-converting enzyme 1) and is necessary for the proper localization and function of many of these 'CaaX' proteins. In the present paper, we report that several mammalian species have a novel isoform (isoform 2) of RCE1 resulting from an alternate splice site and producing an N-terminally truncated protein. We demonstrate that both RCE1 isoform 1 and the newly identified isoform 2 are required to reinstate proper H-Ras processing and thus plasma membrane localization in RCE1-null cells. In addition, we show that the deubiquitinating enzyme USP17 (ubiquitin-specific protease 17), previously shown to modulate RCE1 activity, can regulate the abundance and localization of isoform 2. Furthermore, we show that isoform 2 is ubiquitinated on Lys43 and deubiquitinated by USP17. Collectively, the findings of the present study indicate that RCE1 isoform 2 is required for proper 'CaaX' processing and that USP17 can regulate this via its modulation of RCE1 isoform 2 ubiquitination.

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A technique for optimizing the efficiency of the sub-map method for large-scale simultaneous localization and mapping (SLAM) is proposed. It optimizes the benefits of the sub-map technique to improve the accuracy and consistency of an extended Kalman filter (EKF)-based SLAM. Error models were developed and engaged to investigate some of the outstanding issues in employing the sub-map technique in SLAM. Such issues include the size (distance) of an optimal sub-map, the acceptable error effect caused by the process noise covariance on the predictions and estimations made within a sub-map, when to terminate an existing sub-map and start a new one and the magnitude of the process noise covariance that could produce such an effect. Numerical results obtained from the study and an error-correcting process were engaged to optimize the accuracy and convergence of the Invariant Information Local Sub-map Filter previously proposed. Applying this technique to the EKF-based SLAM algorithm (a) reduces the computational burden of maintaining the global map estimates and (b) simplifies transformation complexities and data association ambiguities usually experienced in fusing sub-maps together. A Monte Carlo analysis of the system is presented as a means of demonstrating the consistency and efficacy of the proposed technique.

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In existing WiFi-based localization methods, smart mobile devices consume quite a lot of power as WiFi interfaces need to be used for frequent AP scanning during the localization process. In this work, we design an energy-efficient indoor localization system called ZigBee assisted indoor localization (ZIL) based on WiFi fingerprints via ZigBee interference signatures. ZIL uses ZigBee interfaces to collect mixed WiFi signals, which include non-periodic WiFi data and periodic beacon signals. However, WiFi APs cannot be identified from these WiFi signals by ZigBee interfaces directly. To address this issue, we propose a method for detecting WiFi APs to form WiFi fingerprints from the signals collected by ZigBee interfaces. We propose a novel fingerprint matching algorithm to align a pair of fingerprints effectively. To improve the localization accuracy, we design the K-nearest neighbor (KNN) method with three different weighted distances and find that the KNN algorithm with the Manhattan distance performs best. Experiments show that ZIL can achieve the localization accuracy of 87%, which is competitive compared to state-of-the-art WiFi fingerprint-based approaches, and save energy by 68% on average compared to the approach based on WiFi interface.

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A field and market basket study (similar to 1300 samples) of locally grown fruits and vegetables from historically mined regions of southwest (SW) England (Cornwall and Devon), and as reference, a market basket study of similarly locally grown produce from the northeast (NE) of Scotland (Aberdeenshire) was conducted to determine the concentration of total and inorganic arsenic present in produce from these two geogenically different areas of the U.K. On average 98.5% of the total arsenic found was present in the inorganic form. For both the market basket and the field survey, the highest total arsenic was present in open leaf structure produce (i.e., kale, chard, lettuce, greens, and spinach) being most likely to soil/dust contamination of the open leaf structure. The concentration of total arsenic in potatoes, swedes, and carrots was lower in peeled produce compared to unpeeled produce. For baked potatoes, the concentration of total arsenic in the skin was higher compared to the total arsenic concentration of the potato flesh, this difference in localization being confirmed by laser ablation inductively coupled plasma mass spectroscopy (LA-ICP-MS). For all above ground produce (e.g., apples), peeling did not have a significant effect on the concentration of total arsenic present.

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Ceria (CeO2) and ceria-based composite materials, especially Ce1-xZrxO2 solid solutions, possess a wide range of applications in many important catalytic processes, such as three-way catalysts, owing to their excellent oxygen storage capacity (OSC) through the oxygen vacancy formation and refilling. Much of this activity has focused on the understanding of the electronic and structural properties of defective CeO2 with and without doping, and comprehending the determining factor for oxygen vacancy formation and the rule to tune the formation energy by doping has constituted a central issue in material chemistry related to ceria. However, the calculation on electronic structures and the corresponding relaxation patterns in defective CeO2-x oxides remains at present a challenge in the DFT framework. A pragmatic approach based on density functional theory with the inclusion of on-site Coulomb correction, i.e. the so-called DFT + U technique, has been extensively applied in the majority of recent theoretical investigations. Firstly, we review briefly the latest electronic structure calculations of defective CeO2(111), focusing on the phenomenon of multiple configurations of the localized 4f electrons, as well as the discussions of its formation mechanism and the catalytic role in activating the O-2 molecule. Secondly, aiming at shedding light on the doping effect on tuning the oxygen vacancy formation in ceria-based solid solutions, we summarize the recent theoretical results of Ce1-xZrxO2 solid solutions in terms of the effect of dopant concentrations and crystal phases. A general model on O vacancy formation is also discussed; it consists of electrostatic and structural relaxation terms, and the vital role of the later is emphasized. Particularly, we discuss the crucial role of the localized structural relaxation patterns in determining the superb oxygen storage capacity in kappa-phase Ce1-xZr1-xO2. Thirdly, we briefly discuss some interesting findings for the oxygen vacancy formation in pure ceria nanoparticles (NPs) uncovered by DFT calculations and compare those with the bulk or extended surfaces of ceria as well as different particle sizes, emphasizing the role of the electrostatic field in determining the O vacancy formation.

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Indoor personnel localization research has generated a range of potential techniques and algorithms. However, these typically do not account for the influence of the user's body upon the radio channel. In this paper an active RFID based patient tracking system is demonstrated and three localization algorithms are used to estimate the location of a user within a modern office building. It is shown that disregarding body effects reduces the accuracy of the algorithms' location estimates and that body shadowing effects create a systematic position error that estimates the user's location as closer to the RFID reader that the active tag has line of sight to.