580 research outputs found

    Mining Novel Multivariate Relationships in Time Series Data Using Correlation Networks

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    In many domains, there is significant interest in capturing novel relationships between time series that represent activities recorded at different nodes of a highly complex system. In this paper, we introduce multipoles, a novel class of linear relationships between more than two time series. A multipole is a set of time series that have strong linear dependence among themselves, with the requirement that each time series makes a significant contribution to the linear dependence. We demonstrate that most interesting multipoles can be identified as cliques of negative correlations in a correlation network. Such cliques are typically rare in a real-world correlation network, which allows us to find almost all multipoles efficiently using a clique-enumeration approach. Using our proposed framework, we demonstrate the utility of multipoles in discovering new physical phenomena in two scientific domains: climate science and neuroscience. In particular, we discovered several multipole relationships that are reproducible in multiple other independent datasets and lead to novel domain insights.Comment: This is the accepted version of article submitted to IEEE Transactions on Knowledge and Data Engineering 201

    Structural and magnetic phenomena in Ni53Mn25Al22 thin film prepared by rf magnetron sputtering

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    Magnetic and structural properties of Ni–Mn–Al thin films are investigated. It is demonstrated that the annealed film shows L21 phase at room temperature. Magnetometry measurements reveal that the annealed film is ferromagnetic and a first order transition in magnetization versus temperature measurement confirms that the martensite to austenite transition occurs around room temperature. Transmission electron microscopy measurements confirm that this structural change occurs just below room temperature. The splitting of Mn 2p3/2 level in x-ray photoelectron spectroscopy core level spectra of the annealed Ni–Mn–Al film, confirms that the origin of magnetism is definitely correlated with the local magnetic moment at the Mn atoms

    P2X7 Receptor as a Key Player in Oxidative Stress-Driven Cell Fate in Nonalcoholic Steatohepatitis

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    Incidences of nonalcoholic fatty liver disease parallels increase in the global obesity epidemic. NAFLD has been shown to be associated with risks of cardiometabolic disorders and kidney disturbances. It is accompanied by insulin and leptin resistance that complicate the diagnosis and treatment of this public health menace. Though significant research is underway for understanding the molecular mechanisms of NAFLD and its subsequent inflammatory and fibrotic manifestations like nonalcoholic steatohepatitis, the role of purinergic receptors has been unclear. It is increasingly being recognized that damage associated molecular patterns like NAD and ATP that are released from injured cells via hepatocellular injury either by oxidative stress or lipotoxicity from steatosis activate the purinergic receptor. Based on evidence from inflammatory responses in the airways and vasculature and autoimmune complications in humans and rodents, it is beyond doubt that hepatocellular inflammation such as that seen in NASH can result from the activation of purinergic receptors. This event can result in the formation of inflammasomes and can be an important pathway for the progression of NASH. The present review evaluates the current knowledge of the role of oxidative stress and its signaling via P2X7 receptors in hepatocellular injury that might contribute to the NASH pathophysiology

    Mempelajari Sifat Fisika Sol Karet Cetak Dengan Filler Cangkang Telur Ayam

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    Tujuan penelitian adalah untuk menpelajari sifat fisika sol karet cetak dengan filler cangkang telur ayam. Sifat fisika yang dipelajari meliputi kekerasan, tegangan putus, ketahanan sobek dan ketahanan kikis. Penelitian dilakukan dengan 4 tahap yaitu pembuatan filler cangkang telur ayam, pembuatan sol karet cetak, pengujian sifat fisika dan penilaian secara visual. Perlakuan terdiri dari penggunaan cangkang telur ayam menggantikan filer karbon hitam meliputi perlakuan tanpa penggunaan cangkang telur ayam (A1), penggunaan filler cangkang telur ayam 15 Phr (B1), penggunaan filer cangkang telur ayam 30 Phr (C1) dan penggunaan filler cangkang telur ayam 45 Phr (D1). Hasil penelitian menunjukkan bahwa cangkang telur ayam dapat digunakan sebagai filler pada pembuatan sol karet cetak. Penggunaan filler cangkang telur ayam yang semakin meningkat menghasilkan sol karet cetak dengan kekerasan yang cenderung semakin menurun, tegangan putus yang semakin menurun, ketahanan sobek yang semakin menurun dan ketahanan kikis yang semakin meningkat. Secara fisual sol karet cetak yang dihasilkan dari filler cangkang telur ayam menghasilkan sol karet cetak yang baik (tidak cacat berupa sobek, lubang, lepuh, retak dan goresan)

    An Investigation on Super-and Sub-Terminal Drops in Two Different Rain Categories and Climate Regimes

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    The pressing need for accurate and reliable precipitation measurements and forecasting poses theoretical and technological problems. Remote-sensing instruments with increased coverage and sensitivity (such as space-borne and ground-based radar) are available; however, their full exploitation requires physical calibration and validation based on a deep knowledge of precipitation microphysics. This study reports a detailed analysis of the evidence of non-terminal velocities in a mid-latitude (Bologna, Italy) and a tropical location (Kolkata, India). The data from two identical disdrometers OTT-Parsivel2 were analyzed to shed light on the nature of the raindrops that fall at a velocity that is significantly higher (i.e., super-terminal drops) or lower (sub-terminal drops) than the terminal velocity expected for the raindrop sizes. The results show a significant fraction of super- and sub-terminal drops in both locations. The percentages of both super- and sub-terminal drops were higher in Kolkata. However, the difference was more notable for convective rain. The percentages of both super- and sub-terminal drops were found to be high within a drop diameter of 1 mm. The number of sub-terminal drops seemed to increase with an increase in diameter for drops larger than ~2.5 mm. The natural rain in Bologna showed stronger evidence of drop break-up in correspondence with the evolution of non-terminal velocities. Moreover, this study once again pointed toward the fact that the process of break-up cannot be neglected in natural rain of tropical or mid-latitude locations. We found that 7% and 10% of rain samples in Bologna and Kolkata seemed to be subjected to drop break-up. The results indicate that radar measurements of rain in the tropics or mid-latitude regions, relying on the Gunn–Kinzer relationship between velocity and diameter, should be verified by observations of disdrometers for a high precision QPE
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