383 research outputs found

    Selective rendering for efficient ray traced stereoscopic images

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    Depth-related visual effects are a key feature of many virtual environments. In stereo-based systems, the depth effect can be produced by delivering frames of disparate image pairs, while in monocular environments, the viewer has to extract this depth information from a single image by examining details such as perspective and shadows. This paper investigates via a number of psychophysical experiments, whether we can reduce computational effort and still achieve perceptually high-quality rendering for stereo imagery. We examined selectively rendering the image pairs by exploiting the fusing capability and depth perception underlying human stereo vision. In ray-tracing-based global illumination systems, a higher image resolution introduces more computation to the rendering process since many more rays need to be traced. We first investigated whether we could utilise the human binocular fusing ability and significantly reduce the resolution of one of the image pairs and yet retain a high perceptual quality under stereo viewing condition. Secondly, we evaluated subjects' performance on a specific visual task that required accurate depth perception. We found that subjects required far fewer rendered depth cues in the stereo viewing environment to perform the task well. Avoiding rendering these detailed cues saved significant computational time. In fact it was possible to achieve a better task performance in the stereo viewing condition at a combined rendering time for the image pairs less than that required for the single monocular image. The outcome of this study suggests that we can produce more efficient stereo images for depth-related visual tasks by selective rendering and exploiting inherent features of human stereo vision

    Home-Based Care for People with Alzheimer's Disease and Related Dementias (ADRD) during COVID-19 Pandemic: From Challenges to Solutions.

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    There has been supporting evidence that older adults with underlying health conditions form the majority of the fatal cases in the current novel coronavirus disease (COVID-19) pandemic. While the impact of COVID-19 is affecting the general public, it is clear that these distressful experiences will be magnified in older adults, particularly people living with Alzheimer's disease and related dementia (ADRD), making them the most vulnerable group during this time. People with differing degrees of ADRD are especially susceptible to the virus, not only because of their difficulties in assessing the threat or remembering the safety measures, but also because of the likelihood to be subject to other risk factors, such as lack of proper care and psychological issues. Therefore, in this article, we will discuss the challenges related to home-based care for people with ADRD during a pandemic and propose a formulation of systematic solutions to address these challenges and to alleviate the social and economic impact resulting from the crisis

    Integrin-mediated membrane blebbing is dependent on the NHE1 and NCX1 activities.

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    Integrin-mediated signal transduction and membrane blebbing have been well studied to modulate cell adhesion, spreading and migration^1-6^. However, the relationship between membrane blebbing and integrin signaling has not been explored. Here we show that integrin-ligand interaction induces membrane blebbing and membrane permeability change. We found that sodium-proton exchanger 1 (NHE1) and sodium-calcium exchanger 1 (NCX1) are located in the membrane blebbing sites and inhibition of NHE1 disrupts membrane blebbing and decreases membrane permeability change. However, inhibition of NCX1 enhances cell blebbing to cause cell swelling which is correlated with an intracellular sodium accumulation induced by NHE17. These data suggest that sodium influx induced by NHE1 is a driving force for membrane blebbing growth, while sodium efflux induced by NCX1 in a reverse mode causes membrane blebbing retraction. Together, these data reveal a novel function of NHE1 and NCX1 in membrane permeability change and blebbing and provide the link for integrin signaling and membrane blebbing

    Study of sponge gourd ascorbate peroxidase and winter squash superoxide dismutase under respective flooding and chilling stresses

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    AbstractThe objectives of this work were to study the responses of ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), and physiological parameters of bitter melon (BM), sponge gourd (SG), and winter squash (WS) under waterlogged and low temperature conditions. The BM and SG plants were subjected to 0–72h flooding treatments. Moreover, BM and WS plants were exposed to chilling at 12/7°C (day/night) for 0–72h. The results show that different genotypes responded differently to environmental stress according to their various antioxidant enzymes and physiological parameters. The activity of APX in roots and leaves of SG plants significantly higher than that of BM plants during continuous flooding. Significant increases in SOD activity in leaves of WS plants were also observed throughout the entire chilling duration compared to BM plants. On the basis of our observations, we conclude that increased APX and SOD activities provide SG and WS plants with increased waterlogging and chilling stress tolerance, respectively. Both APX and SOD activities can be used for selecting BM lines with the best tolerances to water logging and chilling stresses

    Levels and values of circulating endothelial progenitor cells, soluble angiogenic factors, and mononuclear cell apoptosis in liver cirrhosis patients

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    BACKGROUND: The roles of circulating endothelial progenitor cell (EPC) and mononuclear cell apoptosis (MCA) in liver cirrhosis (LC) patients are unknown. Moreover, vascular endothelial growth factor (VEGF) and stromal cell-derived factor (SDF)-1α are powerful endogenous substances enhancing EPC migration into circulation. We assessed the level and function of EPCs [CD31/CD34 (E(1)), KDR/CD34 (E(2)), CXCR4/CD34 (E(3))], levels of MCA, VEGF and SDF-1α in circulation of LC patients. METHODS: Blood sample was prospectively collected once for assessing EPC level and function, MCA, and plasma levels of VEGF and SDF-1α using flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively, in 78 LC patients and 25 age- and gender-matched healthy controls. RESULTS: Number of EPCs (E(1), E(2), E(3)) was lower (all p < 0.0001), whereas SDF-1α level and MCA were higher (p < 0.001) in study patients compared with healthy controls. Number of EPCs (E(2), E(3)) was higher but MCA was lower (all p < 0.05) in Child's class A compared with Child's class B and C patients, although no difference in VEGF and SDF-1α levels were noted among these patients. Chronic hepatitis B and esophageal varices bleeding were independently, whereas chronic hepatitis C, elevated aspartate aminotransferase (AST), and decompensated LC were inversely and independently correlated with circulating EPC level (all p < 0.03). Additionally, angiogenesis and transwell migratory ability of EPCs were reduced in LC patients than in controls (all p < 0.001). CONCLUSION: The results of this study demonstrated that level, angiogenic capacity, and function of circulating EPCs were significantly reduced, whereas plasma levels of SDF-1α and circulating MCA were substantially enhanced in cirrhotic patients

    (Benzophenone imine-κN)­chlorido(hydrido­tripyrazolyl­borato)­(triphenyl­phosphine)ruthenium(II) diethyl ether solvate

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    The reaction of RuCl(Tp)(Ph3P)2, where Tp is [(CH)3N2]3BH, with benzophenone imine leads to the formation of the title compound, [Ru(C9H10BN6)Cl(C13H11N)(C18H15P)]·C4H10O. The environment about the Ru atom corresponds to a slightly distorted octa­hedron and the bite angle of the Tp ligand produces an average N—Ru—N angle of 86.3 (9)°. The three Ru—N(Tp) bond lengths [2.117 (2), 2.079 (2) and 2.084 (2) Å] are slightly longer than the average distance (2.038 Å) in other ruthenium–Tp complexes

    Serum Bone Resorption Markers after Parathyroidectomy for Renal Hyperparathyroidism: Correlation Analyses for the Cross-Linked N-telopeptide of Collagen I and Tartrate-Resistant Acid Phosphatase

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    Patients on long-term dialysis may develop secondary hyperparathyroidism (SHPT) with increased serum concentrations of bone resorption markers such as the cross-linked N-telopeptide of type I collagen (NTX) and type-5b tartrate-resistant acid phosphatase (TRAP). When SHPT proves refractory to treatment, parathyroidectomy (PTX) may be needed. Renal patients on maintenance HD who received PTX for refractory SHPT (n=23) or who did not develop refractory SHPT (control subjects; n=25) were followed prospectively for 4 weeks. Serum intact parathyroid hormone (iPTH), NTX, TRAP, and bone alkaline phosphatase (BAP) concentrations were measured serially and correlation analyses were performed. iPTH values decreased rapidly and dramatically. BAP values increased progressively with peak increases observed at 2 weeks after surgery. NTX and TRAP values decreased concurrently and progressively through 4 weeks following PTX. A significant correlation between TRAP and NTX values was observed before PTX but not at 4 weeks after PTX. Additionally, the fractional changes in serum TRAP were larger than those in serum NTX at all times examined after PTX. Serum iPTH, TRAP, and NTX values declined rapidly following PTX for SHPT. Serum TRAP values declined to greater degrees than serum NTX values throughout the 4-week period following PTX

    Review—a conceptual analysis on ceramic materials used for dental practices : manufacturing techniques and microstructure

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    In the era of biomaterials evolution, ceramic materials are playing a notable role in dental practices. Ceramics have been used in dental applications for several decades because of its important properties such as suitable biological incorporation into human body, surface colouration, enhanced surface morphology, mechanical characteristics, physiochemical integration, durability and lifespan. There are numerous complications in the fabrication and production of ceramics by manufacturers. Therefore, many research and development has been performed to further improve and understand the manufacturing mechanism that occurs on the ceramic materials. These efforts are not only able to improve the fundamental understanding of the material but also help to meet the customer satisfaction and quality of production. This review article mainly provides an insight of various ceramic materials with a focus on their properties including stability, strength, and heat resistance. It is corroborated with a detailed account of various ceramic fabrication processing techniques with their applications that include sol-gel casting, hot pressing and phase inversion methods. In summary, some critical suggestions as well as detailed scope of future aspects and frontiers have been outlined to provide robust improvements for research and development platforms
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