36,701 research outputs found

    Hurst parameter analysis of radio pulsar timing noise

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    We present an analysis of timing residual (noise) of 54 pulsars obtained from 25-m radio telescope at Urumqi Observatory with a time span of 5~8 years, dealing with statistics of the Hurst parameter. The majority of these pulsars were selected to have timing noise that look like white noise rather than smooth curves. The results are compared with artificial series of different constant pairwise covariances. Despite the noise like appearance, many timing residual series showed Hurst parameters significantly deviated from that of independent series. We concluded that Hurst parameter may be capable of detecting dependence in timing residual and of distinguishing chaotic behavior from random processes.Comment: 7 pages, 3 figures, 2 tables, Submitted to MNRA

    Molecular mechanisms underlying anti-tumor promoting activities of heat-processed Panax ginseng C.A. Meyer.

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    Recently, there have been considerable efforts to search for naturally occurring substances that can inhibit, reverse, or retard the multi-stage carcinogenesis. A wide array of phenolic substances derived from edible and medicinal plants have been reported to possess anticarcinogenic and antimutagenic activities and in many cases, the chemopreventive activities of phytochemicals are associated with their anti-inflammatory and/or antioxidative properties. Panax ginseng C.A. Meyer cultivated in Korea has been widely used in traditional herbal medicine for the treatment of various diseases. Certain fractions or purified ingredients of ginseng have been shown to exert anticarcinogenic and antimutagenic activities. Our previous studies have revealed that the methanol extract of heat-processed Panax ginseng C.A. Meyer attenuates the lipid peroxidation in rat brain homogenates and is also capable of scavenging superoxide generated by xanthine- xanthine oxidase or by 12-O-tetradecanoylphorbol-13-acetate (TPA) in differentiated human promyelocytic leukemia (HL-60) cells. Topical application of the same extract onto shaven backs of female ICR mice also suppressed TPA-induced skin tumor promotion. Likewise, topical application of ginsenoside Rg3, one of the constituents of heat-treated ginseng, significantly inhibited TPA-induced mouse epidermal ornithine decarboxylase activity and skin tumor promotion. Expression of cyclooxygenase-2 (COX-2) in TPA-stimulated mouse skin was markedly suppressed by Rg3 pretreatment. In addition, Rg3 inhibited TPA-stimulated activation of NF-kappaB and extracellular-regulated protein kinase (ERK), one of the mitogen-activated protein (MAP) kinase in mouse skin and also in cultured human breast epithelial cells (MCF-10A)

    Similarity Solutions for Boundary Layer Flows on a Moving Surface in Non-Newtonian Power-Law Fluids

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    A similarity analysis of the boundary layer flow caused by the motion of a semi-infinite flat sulface in a non-Newtonian power-law fluid at rest is made in this paper. These similar solutions fall into two categories: similarity solutions corresponding to steady boundary layers over moving surfaces and similarity solutions corresponding to unsteady boundary layers past moving flat surfaces, respectively. Except in the special case n = 1/2 (pseudoplastic) and n = 1 (Newtonian) fluids, solutions of the first category problems must be obtainednumerically. However, for the second category analytical solutions are possible for a large class of pseudoplasticfluids (n < 1), including the case of a Newtonianfluid (n = 1)

    Verifying Policy Enforcers

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    Policy enforcers are sophisticated runtime components that can prevent failures by enforcing the correct behavior of the software. While a single enforcer can be easily designed focusing only on the behavior of the application that must be monitored, the effect of multiple enforcers that enforce different policies might be hard to predict. So far, mechanisms to resolve interferences between enforcers have been based on priority mechanisms and heuristics. Although these methods provide a mechanism to take decisions when multiple enforcers try to affect the execution at a same time, they do not guarantee the lack of interference on the global behavior of the system. In this paper we present a verification strategy that can be exploited to discover interferences between sets of enforcers and thus safely identify a-priori the enforcers that can co-exist at run-time. In our evaluation, we experimented our verification method with several policy enforcers for Android and discovered some incompatibilities.Comment: Oliviero Riganelli, Daniela Micucci, Leonardo Mariani, and Yli\`es Falcone. Verifying Policy Enforcers. Proceedings of 17th International Conference on Runtime Verification (RV), 2017. (to appear

    Twisted Masses and Enhanced Symmetries: the A&D Series

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    We study new symmetries between A and D type quiver gauge theories with different numbers of colors. We realize these gauge theories with twisted masses via a brane construction that reproduces all the parameters of the Gauge/Bethe correspondence.Comment: 14 pages, 5 figure

    Pre-weaning growth of lambs under village management system in Konni Local Government Area of Tahoua State in Niger Republic

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    This study evaluated the pre-weaning growth performance of a total of 144 lambs from 118 dams selected purposively from cooperating farmers’ flocks in Gabastawa and Gumbi villages in Konni Local Government Area of Tahoua State in Niger Republic. Body weight of the lambs was assessed weekly, using the hanging type weight-balance, for a period of 12 weeks. Prior to the weekly weighing, each of the lambs was identified, using plastic number tags, on the bases of breed, sex, birth type, location of flock, nutritional status and parity of dam which were recorded on the lambs’ record card. Data collected was analyzed using SPSS software package (SPSS, 1995); and student's t-­‐test as well as Duncan’s new multiple range tests were used for mean separations. Results of the study revealed that mean bodyweight of lambs increased from 2.56±0.75 kg at one week after birth to 10.25±1.80 kg at 12 weeks after birth. Mean body weight gain of the lambs was 641 g week-­‐1 (or 91.5 g day-­­‐1). The lambs’ pre-­‐weaning body weight changes produced a linear regression equation; Y = 0.598x + 3.518; and R2 = 93%. Of the various factors considered, only nutritional status of dam showed significant (P < 0.05) effect on the lambs’ pre-weaning body weights. Lambs from dams that had adequate nutrition weighed significantly (P < 0.05) heavier from week 2 (5.99±2.5 kg) to week 12 (13.14±2.2 kg); followed by those lambs from dams that had moderately adequate nutrition from week 6 to 12 and than those from the dams that had inadequate nutrition from week 2 (3.55±1.9 kg) to week 12 (8.83±2.0). It can be concluded that the pre-weaning growth performance of lambs in this study was comparable to those obtained under on-­‐stationand the results underscore the importance of adequate nutrition as a major factor that influences lambs pre-­‐weaning growth performance under the village production system. Hence, adequate nutrition of dams should be ensured to improve the pre-weaning growth of the lambs and overall productivity of sheep in the study area.Key words: Pre-weaning growth, Lambs, Traditional management system, Niger Republi

    Azimuthal distributions of radial momentum and velocity in relativistic heavy ion collisions

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    Azimuthal distributions of radial (transverse) momentum, mean radial momentum, and mean radial velocity of final state particles are suggested for relativistic heavy ion collisions. Using transport model AMPT with string melting, these distributions for Au + Au collisions at 200 GeV are presented and studied. It is demonstrated that the distribution of total radial momentum is more sensitive to the anisotropic expansion, as the anisotropies of final state particles and their associated transverse momentums are both counted in the measure. The mean radial velocity distribution is compared with the radial {\deg}ow velocity. The thermal motion contributes an isotropic constant to mean radial velocity
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