1,329 research outputs found

    PERCEPTION AND INTERPRETATION AT THE CORE OF COMMUNICATION

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    A theoretical-review approach to visually mediated communication is offered, and the emphasis is on how visual stimuli affect the subconscious mind and how they can influence an individual's reactions. The environment is constantly changing, and one of the factors for this is the constant exchange of visual information. That is why the assumption is made that visual intelligence is of particular importance in selection in the sea of information. In this context, the effectiveness of communication is largely measured by the emotional effect it evokes. Of particular importance is the filtering of the useful from the unnecessary, and it is important to assess the need for visual communication. The other assumption is that the essence of visual intelligence, in turn, is rooted in the awareness and management of a critical evaluation of perception (1)

    Von Bezold assimilation effect reverses in stereoscopic conditions

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    Lightness contrast and lightness assimilation are opposite phenomena: in contrast, grey targets appear darker when bordering bright surfaces (inducers) rather than dark ones; in assimilation, the opposite occurs. The question is: which visual process favours the occurrence of one phenomenon over the other? Researchers provided three answers to this question. The first asserts that both phenomena are caused by peripheral processes; the second attributes their occurrence to central processes; and the third claims that contrast involves central processes, whilst assimilation involves peripheral ones. To test these hypotheses, an experiment on an IT system equipped with goggles for stereo vision was run. Observers were asked to evaluate the lightness of a grey target, and two variables were systematically manipulated: (i) the apparent distance of the inducers; and (ii) brightness of the inducers. The retinal stimulation was kept constant throughout, so that the peripheral processes remained the same. The results show that the lightness of the target depends on both variables. As the retinal stimulation was kept constant, we conclude that central mechanisms are involved in both lightness contrast and lightness assimilation

    Digital Elevation Models: Terminology and Definitions

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    Digital elevation models (DEMs) provide fundamental depictions of the three-dimensional shape of the Earth’s surface and are useful to a wide range of disciplines. Ideally, DEMs record the interface between the atmosphere and the lithosphere using a discrete two-dimensional grid, with complexities introduced by the intervening hydrosphere, cryosphere, biosphere, and anthroposphere. The treatment of DEM surfaces, affected by these intervening spheres, depends on their intended use, and the characteristics of the sensors that were used to create them. DEM is a general term, and more specific terms such as digital surface model (DSM) or digital terrain model (DTM) record the treatment of the intermediate surfaces. Several global DEMs generated with optical (visible and near-infrared) sensors and synthetic aperture radar (SAR), as well as single/multi-beam sonars and products of satellite altimetry, share the common characteristic of a georectified, gridded storage structure. Nevertheless, not all DEMs share the same vertical datum, not all use the same convention for the area on the ground represented by each pixel in the DEM, and some of them have variable data spacings depending on the latitude. This paper highlights the importance of knowing, understanding and reflecting on the sensor and DEM characteristics and consolidates terminology and definitions of key concepts to facilitate a common understanding among the growing community of DEM users, who do not necessarily share the same backgroun

    A gap in the spectrum of the Neumann-Laplacian on a periodic waveguide

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    We will study the spectral problem related to the Laplace operator in a singularly perturbed periodic waveguide. The waveguide is a quasi-cylinder with contains periodic arrangement of inclusions. On the boundary of the waveguide we consider both Neumann and Dirichlet conditions. We will prove that provided the diameter of the inclusion is small enough in the spectrum of Laplacian opens spectral gaps, i.e. frequencies that does not propagate through the waveguide. The existence of the band gaps will verified using the asymptotic analysis of elliptic operators.Comment: 26 pages, 6 figure

    A specific scoliosis classification correlating with brace treatment: description and reliability

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    <p>Abstract</p> <p>Background</p> <p>Spinal classification systems for scoliosis which were developed to correlate with surgical treatment historically have been used in brace treatment as well. Previously, there had not been a scoliosis classification system developed specifically to correlate with brace design and treatment. The purpose of this study is to show the intra- and inter- observer reliability of a new scoliosis classification system correlating with brace treatment.</p> <p>Methods</p> <p>An original classification system ("Rigo Classification") was developed in order to define specific principles of correction required for efficacious brace design and fabrication. The classification includes radiological as well as clinical criteria. The radiological criteria are utilized to differentiate five basic types of curvatures including: (I) imbalanced thoracic (or three curves pattern), (II) true double (or four curve pattern), (III) balanced thoracic and false double (non 3 non 4), (IV) single lumbar and (V) single thoracolumbar. In addition to the radiological criteria, the Rigo Classification incorporates the curve pattern according to SRS terminology, the balance/imbalance at the transitional point, and L4-5 counter-tilting. To test the intra-and inter-observer reliability of the Rigo Classification, three observers (1 MD, 1 PT and 1 CPO) measured (and one of them, the MD, re-measured) 51 AP radiographs including all curvature types.</p> <p>Results</p> <p>The intra-observer Kappa value was 0.87 (acceptance >0.70). The inter-observer Kappa values fluctuated from 0.61 to 0.81 with an average of 0.71 (acceptance > 0.70).</p> <p>Conclusions</p> <p>A specific scoliosis classification which correlates with brace treatment has been proposed with an acceptable intra-and inter-observer reliability.</p

    Hsp90 orchestrates transcriptional regulation by Hsf1 and cell wall remodelling by MAPK signalling during thermal adaptation in a pathogenic yeast

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    Acknowledgments We thank Rebecca Shapiro for creating CaLC1819, CaLC1855 and CaLC1875, Gillian Milne for help with EM, Aaron Mitchell for generously providing the transposon insertion mutant library, Jesus Pla for generously providing the hog1 hst7 mutant, and Cathy Collins for technical assistance.Peer reviewedPublisher PD

    Stoichiometry of Base Excision Repair Proteins Correlates with Increased Somatic CAG Instability in Striatum over Cerebellum in Huntington's Disease Transgenic Mice

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    Huntington's disease (HD) is a progressive neurodegenerative disorder caused by expansion of an unstable CAG repeat in the coding sequence of the Huntingtin (HTT) gene. Instability affects both germline and somatic cells. Somatic instability increases with age and is tissue-specific. In particular, the CAG repeat sequence in the striatum, the brain region that preferentially degenerates in HD, is highly unstable, whereas it is rather stable in the disease-spared cerebellum. The mechanisms underlying the age-dependence and tissue-specificity of somatic CAG instability remain obscure. Recent studies have suggested that DNA oxidation and OGG1, a glycosylase involved in the repair of 8-oxoguanine lesions, contribute to this process. We show that in HD mice oxidative DNA damage abnormally accumulates at CAG repeats in a length-dependent, but age- and tissue-independent manner, indicating that oxidative DNA damage alone is not sufficient to trigger somatic instability. Protein levels and activities of major base excision repair (BER) enzymes were compared between striatum and cerebellum of HD mice. Strikingly, 5′-flap endonuclease activity was much lower in the striatum than in the cerebellum of HD mice. Accordingly, Flap Endonuclease-1 (FEN1), the main enzyme responsible for 5′-flap endonuclease activity, and the BER cofactor HMGB1, both of which participate in long-patch BER (LP–BER), were also significantly lower in the striatum compared to the cerebellum. Finally, chromatin immunoprecipitation experiments revealed that POLβ was specifically enriched at CAG expansions in the striatum, but not in the cerebellum of HD mice. These in vivo data fit a model in which POLβ strand displacement activity during LP–BER promotes the formation of stable 5′-flap structures at CAG repeats representing pre-expanded intermediate structures, which are not efficiently removed when FEN1 activity is constitutively low. We propose that the stoichiometry of BER enzymes is one critical factor underlying the tissue selectivity of somatic CAG expansion

    Cellular pharmacology of multi- and duplex drugsconsisting of ethynylcytidine and 5-fluoro-2′-deoxyuridine

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    Prodrugs can have the advantage over parent drugs in increased activation and cellular uptake. The multidrug ETC-L-FdUrd and the duplex drug ETC-FdUrd are composed of two different monophosphate-nucleosides, 5-fluoro-2′deoxyuridine (FdUrd) and ethynylcytidine (ETC), coupled via a glycerolipid or phosphodiester, respectively. The aim of the study was to determine cytotoxicity levels and mode of drug cleavage. Moreover, we determined whether a liposomal formulation of ETC-L-FdUrd would improve cytotoxic activity and/or cleavage. Drug effects/cleavage were studied with standard radioactivity assays, HPLC and LC-MS/MS in FM3A/0 mammary cancer cells and their FdUrd resistant variants FM3A/TK−. ETC-FdUrd was active (IC50 of 2.2 and 79 nM) in FM3A/0 and TK− cells, respectively. ETC-L-FdUrd was less active (IC50: 7 nM in FM3A/0 vs 4500 nM in FM3A/TK−). Although the liposomal formulation was less active than ETC-L-FdUrd in FM3A/0 cells (IC50:19.3 nM), resistance due to thymidine kinase (TK) deficiency was greatly reduced. The prodrugs inhibited thymidylate synthase (TS) in FM3A/0 cells (80–90%), but to a lower extent in FM3A/TK− (10–50%). FdUMP was hardly detected in FM3A/TK− cells. Inhibition of the transporters and nucleotidases/phosphatases resulted in a reduction of cytotoxicity of ETC-FdUrd, indicating that this drug was cleaved outside the cells to the monophosphates, which was verified by the presence of FdUrd and ETC in the medium. ETC-L-FdUrd and the liposomal formulation were neither affected by transporter nor nucleotidase/phosphatase inhibition, indicating circumvention of active transporters. In vivo, ETC-FdUrd and ETC-L-FdURd were orally active. ETC nucleotides accumulated in both tumor and liver tissues. These formulations seem to be effective when a lipophilic linker is used combined with a liposomal formulation
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