1,973 research outputs found

    Visual units and confusion modelling for automatic lip-reading

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    Automatic lip-reading (ALR) is a challenging task because the visual speech signal is known to be missing some important information, such as voicing. We propose an approach to ALR that acknowledges that this information is missing but assumes that it is substituted or deleted in a systematic way that can be modelled. We describe a system that learns such a model and then incorporates it into decoding, which is realised as a cascade of weighted finite-state transducers. Our results show a small but statistically significant improvement in recognition accuracy. We also investigate the issue of suitable visual units for ALR, and show that visemes are sub-optimal, not but because they introduce lexical ambiguity, but because the reduction in modelling units entailed by their use reduces accuracy

    The cell cycle program of polypeptide labeling in Chlamydomonas reinhardtii

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    The cell cycle program of polypeptide labeling in syndhronous cultures of wild-type Chlamydomonas reinhardtii was analyzed by pulse-labeling cells with 35SO4 = or [3H]arginine at different cell cycle stages. Nearly 100 labeled membrane and soluble polypeptides were resolved and studied using one-dimensional sodium dodecyl sulfate (SDS)- polyacrylamide gel electrophoresis. The labeling experiments produced the following results. (a) Total 35SO4 = and [3H]arginine incorporation rates varied independently throughout the cell cycle. 35SO4 = incorporation was highest in the mid-light phase, while [3H]arginine incorporation peaked in the dark phase just before cell division. (b) The relative labeling rate for 20 of 100 polypeptides showed significant fluctuations (3-12 fold) during the cell cycle. The remaining polypeptides were labeled at a rate commensurate with total 35SO4 = or [3H]arginine incorporation. The polypeptides that showed significant fluctuations in relative labeling rates served as markers to identify cell cycle stages. (c) The effects of illumination conditions on the apparent cell cycle stage-specific labeling of polypeptides were tested. Shifting light-grown asynchronous cells to the dark had an immediate and pronounced effect on the pattern of polypeptide labeling, but shifting dark-phase syndhronous cells to the light had little effect. The apparent cell cycle variations in the labeling of ribulose 1,5-biphosphate (RUBP)-carboxylase were strongly influenced by illumination effects. (d) Pulse-chase experiments with light-grown asynchronous cells revealed little turnover or inter- conversion of labeled polypeptides within one cell generation, meaning that major polypeptides, whether labeled in a stage-specific manner or not, do not appear transiently in the cell cycle of actively dividing, light-grown cells. The cell cycle program of labeling was used to analyze effects of a temperature-sensitive cycle blocked (cb) mutant. A synchronous culture of ts10001 was shifted to restrictive temperature before its block point to prevent it from dividing. The mutant continued its cell cycle program of polypeptide labeling for over a cell generation, despite its inability to divide

    Seasonal Patterns of Flight and Attack of Maple Saplings by the Ambrosia Beetle \u3ci\u3eCorthylus Punctatissimus\u3c/i\u3e (Coleoptera: Scolytidae) in Central Michigan

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    Window traps with ethanol were used to observe seasonal flight patterns of Corthylus punctatissimus in central Michigan. Flights peaked in early July with a second peak seven weeks later in late August. Similarly, wilting of attacked maple (Acer) saplings began to appear a week after initial Corthylus flights, and showed twopeaks, one in mid-July and again with another peak, seven weeks later, in early September. The second peak of activity is presumably from reemerged adults, and not a second generation

    An investigation into determining head pose for gaze estimation on unmodified mobile devices

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    Traditionally, devices which are able to determine a users gaze are large, expensive and often restrictive. We investigate the prospect of using common webcams and mobile devices such as laptops, tablets and phones without modification as an alternative means for obtaining a users gaze. A person’s gaze can be fundamentally determined by the pose of the head as well as the orientation of the eyes. This initial work investigates the first of these factors - an estimate of the 3D head pose (and subsequently the positions of the eye centres) relative to a camera device. Specifically, we seek a low cost algorithm that requires only a one-time calibration for an individual user, that can run in real-time on the aforementioned mobile devices with noisy camera data. We use our head tracker to estimate the 4 eye corners of a user over a 10 second video. We present the results at several different frames per second (fps) to analyse the impact on the tracker with lower quality cameras. We show that our algorithm is efficient enough to run at 75fps on a common laptop, but struggles with tracking loss when the fps is lower than 10fps

    EPR Steering Inequalities from Entropic Uncertainty Relations

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    We use entropic uncertainty relations to formulate inequalities that witness Einstein-Podolsky-Rosen (EPR) steering correlations in diverse quantum systems. We then use these inequalities to formulate symmetric EPR-steering inequalities using the mutual information. We explore the differing natures of the correlations captured by one-way and symmetric steering inequalities, and examine the possibility of exclusive one-way steerability in two-qubit states. Furthermore, we show that steering inequalities can be extended to generalized positive operator valued measures (POVMs), and we also derive hybrid-steering inequalities between alternate degrees of freedom.Comment: 10 pages, 2 figure

    Regulation of Cisplatin Cytotoxicity by Cu Influx Transporters

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    Platinum drugs are an important class of cancer chemotherapeutics. However, the use of these drugs is limited by the development of resistance during treatment with decreased accumulation being a common mechanism. Both Cu transporters CTR1 and CTR2 influence the uptake and cytotoxicity of cisplatin. Although it is structurally similar to CTR1, CTR2 functions in a manner opposite to that of CTR1 with respect to Pt drug uptake. Whereas knockout of CTR1 reduces Pt drug uptake, knockdown of CTR2 enhances cisplatin uptake and cytotoxicity. CTR2 is subject to transcriptional and posttranscriptional regulation by both Cu and cisplatin; this regulation is partly dependent on the Cu chaperone ATOX1. Insight into the mechanisms by which CTR1 and CTR2 regulate sensitivity to the Pt-containing drugs has served as the basis for novel pharmacologic strategies for improving their efficacy

    Aspartame in conjunction with carbohydrate reduces insulin levels during endurance exercise

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    Gold OAAs most sport drinks contain some form of non-nutritive sweetener (e.g. aspartame), and with the variation in blood glucose regulation and insulin secretion reportedly associated with aspartame, a further understanding of the effects on insulin and blood glucose regulation during exercise is warranted. Therefore, the aim of this preliminary study was to profile the insulin and blood glucose responses in healthy individuals after aspartame and carbohydrate ingestion during rest and exercise. Each participant completed four trials under the same conditions (45 min rest + 60 min self-paced intense exercise) differing only in their fluid intake: 1) carbohydrate (2% maltodextrin and 5% sucrose (C)); 2) 0.04% aspartame with 2% maltodextrin and 5% sucrose (CA)); 3) water (W); and 4) aspartame (0.04% aspartame with 2% maltodextrin (A)). Insulin levels dropped significantly for CA versus C alone (43%) between pre-exercise and 30 min, while W and A insulin levels did not differ between these time points. Aspartame with carbohydrate significantly lowered insulin levels during exercise versus carbohydrate alone.Peer Reviewe

    ZmbZIP60 mRNA is spliced in maize in response to ER stress

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    <p>Abstract</p> <p>Background</p> <p>Adverse environmental conditions produce ER stress and elicit the unfolded protein response (UPR) in plants. Plants are reported to have two "arms" of the ER stress signaling pathway-one arm involving membrane-bound transcription factors and the other involving a membrane-associated RNA splicing factor, IRE1. IRE1 in yeast to mammals recognizes a conserved twin loop structure in the target RNA.</p> <p>Results</p> <p>A segment of the mRNA encoding ZmbZIP60 in maize can be folded into a twin loop structure, and in response to ER stress this mRNA is spliced, excising a 20b intron. Splicing converts the predicted protein from a membrane-associated transcription factor to one that is targeted to the nucleus. Splicing of ZmbZIP60 can be elicited in maize seedlings by ER stress agents such as dithiothreitol (DTT) or tunicamycin (TM) or by heat treatment. Younger, rather than older seedlings display a more robust splicing response as do younger parts of leaf, along a developmental gradient in a leaf. The molecular signature of an ER stress response in plants includes the upregulation of Binding Protein (BIP) genes. Maize has numerous BIP-like genes, and ER stress was found to upregulate one of these, ZmBIPb.</p> <p>Conclusions</p> <p>The splicing of ZmbZIP60 mRNA is an indicator of ER stress in maize seedlings resulting from adverse environmental conditions such as heat stress. ZmbZIP60 mRNA splicing in maize leads predictively to the formation of active bZIP transcription factor targeted to the nucleus to upregulate stress response genes. Among the genes upregulated by ER stress in maize is one of 22 BIP-like genes, ZmBIPb.</p
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