21 research outputs found

    Synchronization of coupled nonidentical dynamical systems

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    We analyze the stability of synchronized state for coupled nearly identical dynamical systems on networks by deriving an approximate Master Stability Function (MSF). Using this MSF we treat the problem of designing a network having the best synchronizability properties. We find that the edges which connect nodes with a larger relative parameter mismatch are preferred and the nodes having values at one extreme of the parameter mismatch are preferred as hubs.Comment: 11 pages, 4 figure

    The effect of non-Gaussianity on error predictions for the Epoch of Reionization (EoR) 21-cm power spectrum

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    The Epoch of Reionization (EoR) 21-cm signal is expected to become increasingly non-Gaussian as reionization proceeds. We have used semi-numerical simulations to study how this affects the error predictions for the EoR 21-cm power spectrum. We expect SNR=NkSNR=\sqrt{N_k} for a Gaussian random field where NkN_k is the number of Fourier modes in each kk bin. We find that non-Gaussianity is important at high SNRSNR where it imposes an upper limit [SNR]l[SNR]_l. For a fixed volume VV, it is not possible to achieve SNR>[SNR]lSNR > [SNR]_l even if NkN_k is increased. The value of [SNR]l[SNR]_l falls as reionization proceeds, dropping from 500\sim 500 at xˉHI=0.80.9\bar{x}_{HI} = 0.8-0.9 to 10\sim 10 at xˉHI=0.15\bar{x}_{HI} = 0.15 for a [150.08Mpc]3[150.08\, {\rm Mpc}]^3 simulation. We show that it is possible to interpret [SNR]l[SNR]_l in terms of the trispectrum, and we expect [SNR]lV[SNR]_l \propto \sqrt{V} if the volume is increased. For SNR[SNR]lSNR \ll [SNR]_l we find SNR=Nk/ASNR = \sqrt{N_k}/A with A0.951.75A \sim 0.95 - 1.75, roughly consistent with the Gaussian prediction. We present a fitting formula for the SNRSNR as a function of NkN_k, with two parameters AA and [SNR]l[SNR]_l that have to be determined using simulations. Our results are relevant for predicting the sensitivity of different instruments to measure the EoR 21-cm power spectrum, which till date have been largely based on the Gaussian assumption.Comment: Accepted for publication in MNRAS Letters. The definitive version is available at http://mnrasl.oxfordjournals.org/content/449/1/L4

    Detection of Secondary Metabolites Using HPTLC and GC-MS Analysis and Assessment of Pharmacological Activities of Phoenix loureiroi Kunth (Arecaceae) Ethanolic Leaves Extract in the Management of Pyrexia, Pain and Inflammation

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    The present research work was carried out the High Performance Thin Layer Chromatography (HPTLC) and Gas Chromatography-Mass Spectrometry (GC-MS) analysis and assessment of pharmacological activities of Phoenix loureiroi Kunth (Arecaceae) ethanolic leaves extract at doses of 200, 400 and 600 mg/kg, body weight, per os. Preliminary phytochemical screening, HPTLC and GC-MS studies were carried out according to the standard methods. The acute toxicity studies were conducted on Swiss albino mice as per Organization for Economic Cooperation and Development (OECD) guidelines 420. For the screening of analgesic activity, writhing test was conducted for peripheral analgesic activity whereas tail immersion test was conducted for central analgesic activity. Antipyretic activity was performed by using the yeast induced hyperpyrexia method and for the screening of anti-inflammatory activity carrageenan-induced rat paw edema method was used. Preliminary phytochemical screening of the ethanol extract of Phoenix loureiroi leaves (EEPLL) contains sterols, flavonoids, saponins, proteins, reducing sugar, tannins, and phenolic compounds. The HPTLC analysis method employed in this work resulted in good peak shape and enabled good resolution of quercetin present in the extract and GC-MS analysis showed a total of 25 peaks and led to the identification of 22 different phytoconstituents in the ethanolic extract. Lethal Dose 50 (LD50) was above 2,000 mg/kg and no death was recorded. The prevailing study demonstrated that EEPLL possesses widespread analgesic, antipyretic and anti-inflammatory effects in dose dependent manner. It can be concluded that the ethanolic extract from Phoenix loureiroi leaves possesses promising analgesic, antipyretic and anti-inflammatory activities

    SYNTHESIS & IN-VITRO PROTEIN DENATURATION SCREENING OF 2-[(1, 5-DISUBSTITUTEDPHENYL-4,5-DIHYDRO-1H-PYRAZOL-3-YL)OXY]BENZOIC ACID DERIVATIVES

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    Abstract Novel 2-[(1,5-diphenyl-4,5-dihydro-1H-pyrazol-3-yl)oxy]benzoic acid (2a) & 2-[5-(2-hydroxyphenyl)-1-Phenyl-4,5-dihydro-1H-pyrazol-3-yl]benzoic acid (2b) were produced and examined for their in-vitro protein denaturation activities. It was discovered that compound 2b showed promise and had more potency than acetylsalicylic acid (NSAID) in inhibiting denaturation of bovine serum albumin. Docking research also supports this. The compound 2b has the highest docking scores with COX1(PDB ID 3N8Z), COX2 (PDB ID 4PH9), and TNF (PDB ID 2AZ5), respectively, of Etotal -233.75, -256.48, and -255.83. TLC and elemental tests were used to determine the compounds' purity. All of the generated molecules' analytical and spectral data (1H NMR, FTIR, and MS) were entirely consistent with the proposed structures

    Quantification of Alectinib in spiked rabbit plasma using liquid chromatography- electro spray ionization-tandem mass spectrophotometry: An application to pharmacokinetic study

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    The current technique was developed to estimate the amount of alectinib present in spiked rabbit plasma using liquid chromatographic mass spectrometry. The liquid-liquid extraction method was used, and chromatographic separation was carried out on a C18 (4.6mm id x 50mm) analytical column with a mobile phase consisting of acetonitrile and water with 0.1% formic acid at a volume ratio of 75:25. Alectinib's product m/z +483.2 (parent) 396.1 (product) and the internal standard m/z +447.5 (parent) 380.3 (product) were both obtained using positive ion mode. The calibration curve was linear from 0.5 to 600 ng/ml. The percentage extraction recovery (98.15% → 98.86%), demonstrated excellent matrix and analyte selectivity (% interference = 0), and satisfactory stability study results in all types (% nominal 94.94% → 99.63%). The intra and interday accuracy with % nominal 97 → 98.8%, precision % CV ≤ 2% in all quality control levels. The rabbit model's pharmacokinetic parameters were examined, and alectinib's area under the curve (AUC 0—∞) was 4269 ± 8.13 hr.ng/ml. The half-life of elimination (t1/2) is 8.52 ± 6.66 hours. The currently established approach was used in rabbit blood samples for pharmacokinetic investigations of commercial formulations since it was thought to be a novel, verified bioanalytical method based on experimental results
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