21,170 research outputs found

    Dynamics of tilt-based browsing on mobile devices

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    A tilt-controlled photo browsing method for small mobile devices is presented. The implementation uses continuous inputs from an accelerometer, and a multimodal (visual, audio and vibrotactile) display coupled with the states of this model. The model is based on a simple physical model, with its characteristics shaped to enhance usability. We show how the dynamics of the physical model can be shaped to make the handling qualities of the mobile device fit the browsing task. We implemented the proposed algorithm on Samsung MITs PDA with tri-axis accelerometer and a vibrotactile motor. The experiment used seven novice users browsing from 100 photos. We compare a tilt-based interaction method with a button-based browser and an iPod wheel. We discuss the usability performance and contrast this with subjective experience from the users. The iPod wheel has significantly poorer performance than button pushing or tilt interaction, despite its commercial popularity

    Pregnancy influences the selection of appropriate reference genes in mouse tissue: Determination of appropriate reference genes for quantitative reverse transcription PCR studies in tissues from the female mouse reproductive axis.

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    Selecting stably expressed reference genes which are not affected by physiological or pathophysiological conditions is crucial for reliable quantification in gene expression studies. This study examined the expression stability of a panel of twelve reference genes in tissues from the female mouse reproductive axis and the uterus. Gene expression studies were carried out using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). cDNA was synthesised from RNA extracted from hypothalami, pituitaries, ovaries and uteri of female mice at ages representing weaning, puberty and adulthood as well as pregnancy (13 ± 1 days post-coitus) (n = a minimum of 3 at each age and at pregnancy). The reference genes examined included 18 s, Actb, Atp5b, B2m, Canx, Cyc1, Eif4a2, Gapdh, Rpl13a, Sdha, Ubc and Ywhaz. The RT-qPCR raw data were imported into the qBASE+ software to analyse the expression stability using GeNorm. These data were also subsequently analysed using other software packages (Delta CT, Normfinder, BestKeeper). A comprehensive ranking was conducted considering all stability rankings generated from the different software analyses. B2m and Eif4a2 deviated from the acceptable range for amplification efficiency and therefore were excluded from the further analyses. The stability of the reference genes is influenced by the software used for the analysis with BestKeeper providing markedly different results than the other analyses. GeNorm analysis of tissues taken at different ages but not including pregnant animals, indicated that the expression of the reference genes is tissue specific with the most stable genes being: in the hypothalamus, Canx and Actb; in the pituitary, Sdha and Cyc1; in the ovary, 18s, Sdha and Ubc; and in the uterus, Ywhaz, Cyc1, Atp5b, 18s and Rpl13a. The optimal number of reference genes to be used was determined to be 2 in the first three tissues while in the uterus, the V-score generated by the GeNorm analysis was higher than 0.15 suggesting that 3 or more genes should be used for normalisation. Inclusion of tissues from pregnant mice changed the reference genes identified as being the most stable: Ubc and Sdha were the most stable genes in the hypothalamus, pituitary and the ovary. The addition of pregnant tissue had no effect on the stability of the genes in uterus (Ywhaz, Cyc1, Atp5b, 18s and Rpl13a). Identification of these stable reference genes will be of use to those interested in studying female fertility and researchers should be alert to the effects of pregnancy on reference gene stability. This study also signifies the importance of re-examining reference gene stability if the experimental conditions are changed, as shown with the introduction of pregnancy as a new factor in this research. [Abstract copyright: Crown Copyright © 2021. Published by Elsevier B.V. All rights reserved.

    Perceptual adaptation by normally hearing listeners to a simulated "hole" in hearing

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    Simulations of cochlear implants have demonstrated that the deleterious effects of a frequency misalignment between analysis bands and characteristic frequencies at basally shifted simulated electrode locations are significantly reduced with training. However, a distortion of frequency-to-place mapping may also arise due to a region of dysfunctional neurons that creates a "hole" in the tonotopic representation. This study simulated a 10 mm hole in the mid-frequency region. Noise-band processors were created with six output bands (three apical and three basal to the hole). The spectral information that would have been represented in the hole was either dropped or reassigned to bands on either side. Such reassignment preserves information but warps the place code, which may in itself impair performance. Normally hearing subjects received three hours of training in two reassignment conditions. Speech recognition improved considerably with training. Scores were much lower in a baseline (untrained) condition where information from the hole region was dropped. A second group of subjects trained in this dropped condition did show some improvement; however, scores after training were significantly lower than in the reassignment conditions. These results are consistent with the view that speech processors should present the most informative frequency range irrespective of frequency misalignment. 0 2006 Acoustical Society of America

    An Extended Double Row Layout Problem

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    The double row layout problem (DRLP) seeks to determine optimal machine locations on either side of an aisle, where the objective has been defined as the minimization of material ow cost among ma- chines while meeting machine clearance constraints. In this paper, we extend existing DRLP formulations in two respects. First, we consider the minimization of layout area besides the usual material ow cost objective. Second, we present a mixed integer linear programming formulation that permits non-zero aisle widths. This new formulation also includes new constraints that eliminate layout \mirroring, thus reducing the solution space significantly and thus solution times. Although small-scale problems may be solved optimally by commercial integer programming solvers, solution times are highly sensitive to the number of machines in a layout. A tabu search heuristic is shown to work well for moderately-sized problems. Numerical examples demonstrating the impact of both ow and area objectives, as well as aisle widths, are included

    The effects of Chern-Simons gravity on bodies orbiting the Earth

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    One of the possible low-energy consequences of string theory is the addition of a Chern-Simons term to the standard Einstein-Hilbert action of general relativity. It can be argued that the quintessence field should couple to this Chern-Simons term, and if so, it drives in the linearized theory a parity-violating interaction between the gravito-electric and gravitomagnetic fields. In this paper, the linearized spacetime for Chern-Simons gravity around a massive spinning body is found to include new modifications to the gravitomagnetic field that have not appeared in previous work. The orbits of test bodies and the precession of gyroscopes in this spacetime are calculated, leading to new constraints on the Chern-Simons parameter space due to current satellite experiments.Comment: 9 pages, 2 figures; minor corrections made; to appear in PR

    Combining brain-computer interfaces and assistive technologies: state-of-the-art and challenges

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    In recent years, new research has brought the field of EEG-based Brain-Computer Interfacing (BCI) out of its infancy and into a phase of relative maturity through many demonstrated prototypes such as brain-controlled wheelchairs, keyboards, and computer games. With this proof-of-concept phase in the past, the time is now ripe to focus on the development of practical BCI technologies that can be brought out of the lab and into real-world applications. In particular, we focus on the prospect of improving the lives of countless disabled individuals through a combination of BCI technology with existing assistive technologies (AT). In pursuit of more practical BCIs for use outside of the lab, in this paper, we identify four application areas where disabled individuals could greatly benefit from advancements in BCI technology, namely,“Communication and Control”, “Motor Substitution”, “Entertainment”, and “Motor Recovery”. We review the current state of the art and possible future developments, while discussing the main research issues in these four areas. In particular, we expect the most progress in the development of technologies such as hybrid BCI architectures, user-machine adaptation algorithms, the exploitation of users’ mental states for BCI reliability and confidence measures, the incorporation of principles in human-computer interaction (HCI) to improve BCI usability, and the development of novel BCI technology including better EEG devices

    Syndromic surveillance to assess the potential public health impact of the Icelandic volcanic ash plume across the United Kingdom, April 2010

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    The Eyjafjallajökull volcano in Iceland erupted on 14 April 2010 emitting a volcanic ash plume that spread across the United Kingdom and mainland Europe. The Health Protection Agency and Health Protection Scotland used existing syndromic surveillance systems to monitor community health during the incident: there were no particularly unusual increases in any of the monitored conditions. This incident has again demonstrated the use of syndromic surveillance systems for monitoring community health in real time
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