1,160 research outputs found

    An early Anglo-Saxon bridle-fitting from South Leckaway, Forfar, Angus, Scotland

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    [FIRST PARAGRAPH] In February 2003 the Kinnettles Heritage Group made a quite unexpected find during field-walking at South Leckaway farm near Forfar, Angus (NGR NO 4379 4810): the most northerly example in Britain — by about 150 miles — of an Anglo- Saxon object decorated in Salin’s Style I. It lay isolated and face down on the surface. A follow-up field-walk at the end of the month confirmed, partly with the aid of a metal detector, that there were no readily apparent additional pieces of metalwork, associated structures or burial evidence. The find was reported under the Scottish Treasure Trove legislation, duly claimed and allocated in June 2003 to the Meffan Institute, Forfar (part of Angus Cultural Services)

    Accumulation and melt dynamics of snowpack from a multiresolution regional climate model in the central Sierra Nevada, California

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    The depth and timing of snowpack in the Sierra Nevada Mountains are of fundamental importance to California water resource availability, and recent studies indicate a shift toward earlier snowmelt consistent with projected impacts of anthropogenic climate change. In order for future studies to assess snowpack variability on seasonal to centennial time scales, physically based models of snowpack evolution at high spatial resolution must be improved. Here we evaluate modeled snowpack accuracy for the central Sierra Nevada in the Weather Research and Forecasting regional climate model coupled to the Noah land surface model. A simulation with nested domains at 27, 9, and 3 km grid spacings is presented for November 2001 to July 2002. Model outputs are compared with daily snowpack observations at 41 locations, air temperature at 31 locations, and precipitation at 10 locations. Comparison of snowpack at different resolutions suggests that 27 km simulations substantially underestimate snowpack, while 9 and 3 km simulations are closer to observations. Regional snowpack accumulation is accurately simulated at these high resolutions, but model snowmelt occurs an average of 22-25 days early. Some error can be traced to differences in elevation and observation scale between point-based measurements and model grid cells, but these factors cannot explain the persistent bias toward early snowmelt. A high correlation between snowmelt and error in modeled surface air temperature is found, with melt coinciding systematically with excessively cold air temperatures. One possible source of bias is an imbalance in turbulent heat fluxes, erroneously warming the snowpack while cooling the surface atmosphere

    On Convergence Properties of Shannon Entropy

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    Convergence properties of Shannon Entropy are studied. In the differential setting, it is shown that weak convergence of probability measures, or convergence in distribution, is not enough for convergence of the associated differential entropies. A general result for the desired differential entropy convergence is provided, taking into account both compactly and uncompactly supported densities. Convergence of differential entropy is also characterized in terms of the Kullback-Liebler discriminant for densities with fairly general supports, and it is shown that convergence in variation of probability measures guarantees such convergence under an appropriate boundedness condition on the densities involved. Results for the discrete setting are also provided, allowing for infinitely supported probability measures, by taking advantage of the equivalence between weak convergence and convergence in variation in this setting.Comment: Submitted to IEEE Transactions on Information Theor

    Lepton polarization and CP-violating effects in "B -> K^* tau^+ tau^-" decay in standard and two Higgs doublet models

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    The most general model independent expressions for the CP-violating asymmetry, longitudinal, transversal and normal polarizations of leptons are derived. Application of these general results to the concrete models such as Standard model and three different types of two Higgs doublet model is discussed.Comment: 18 pages, 8 postscripted figure

    Quantum gates with neutral atoms: Controlling collisional interactions in time dependent traps

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    We theoretically study specific schemes for performing a fundamental two-qubit quantum gate via controlled atomic collisions by switching microscopic potentials. In particular we calculate the fidelity of a gate operation for a configuration where a potential barrier between two atoms is instantaneously removed and restored after a certain time. Possible implementations could be based on microtraps created by magnetic and electric fields, or potentials induced by laser light.Comment: 10 pages, 3 figure

    Generalizability of EMG decoding using local field potentials

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    Diffuse emission of organic trace gases from the flank and crater of a quiescent active volcano (Vulcano, Aeolian Islands, Italy)

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    Volcanoes discharge a range of inorganic major gas species (e.g., H2O, CO2, SO2, and CO) not only during eruptions but also during quiescent phases through fumarolic and diffuse degassing in their craters and on their flanks. The emission of organic trace gases from volcanoes is similarly not expected to be restricted to discrete fumarolic gas discharges alone. To test this hypothesis, we have sampled soil gas emissions for organic compounds and determined CO2 fluxes along a profile extending from the vegetated base of the active La Fossa cone (Vulcano Island, Italy) over the unvegetated volcanic flank and up into the crater rim and base and then continuing over fumarolic areas. The results indicate that the majority of volatile organic compounds in the soil gas show significant increases in concentration toward the crater and fumaroles and that diffuse emissions contribute significantly to the volcanic halocarbon source strength. Emissions of the halocarbon CFC-11 (CCl3F) correlate well with soil CO2 fluxes measured on site (R2 = 0.89, slope = 1.42 ± 0.1) and both increase toward the crater and fumaroles. Other ozone-depleting substances were found in concentrations significantly above those found in field and system blanks, including CH3Br, CH3Cl, CH3I, C2H5Br, and chlorinated benzenes. Abundances ranged from upper pptv to ppmv; for example, the maximum observed CFC-11 concentrations were 1200 pptv in diffuse emissions and 3700 pptv in dry fumarolic gas (average dry air is 268 pptv). On the basis of these results the natural volcanic source strength of halocarbon emissions to the atmosphere requires reevaluation, and in some cases, correction to higher values. Global average fumarolic and diffuse halocarbon source strengths were estimated and scaled to known global volcanic fumarolic and diffuse CO2 flux data. Among these were CFC-11 (8.56 ± 4.7 × 10-6 Tg y-1), CH3Br (0.98 ± 0.47 × 10-6 Tg y-1) CHCl3 (94.9 ± 27.6 × 10-6 Tg y-1), and CC14 (3.41 ± 1.0 × 10-6 Tg y-1). Copyright 2004 by the American Geophysical Union.Florian M. Schwandner, Terry M. Seward, Andrew P. Gize, P. Anthony Hall, and Volker J. Dietric

    Supersymmetric effects on Forward Backward asymmetries of BK+B \to K \ell^+ \ell^-

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    Leptonic and semi-leptonic rare decays of B-mesons are very clean (both theoretically and experimentally) signatures of any new physics beyond the Standard Model (SM). More specifically the decay \btokll has been theoretically observed to be very sensitive to new physics as the Forward Backward (FB) asymmetry in this decay mode vanishes in the SM. Supersymmetry, however, predicts a non-vanishing value of this asymmetry. In this work we will study the polarized lepton pair FB asymmetry, i.e. the FB asymmetry of the lepton when one (or both) final state lepton(s) are polarized. We will study these asymmetries both within the SM and for Supersymmetric corrections to the SM.Comment: 18 pages, RevTeX file including 21 eps figures; version accepted for publication in Phys. Rev. D. Some references adde

    Chemotherapy-induced CDA expression renders resistant non-small cell lung cancer cells sensitive to 5'-deoxy-5-fluorocytidine (5'-DFCR).

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    Pemetrexed (MTA) plus cisplatin combination therapy is considered the standard of care for patients with advanced non-small-cell lung cancer (NSCLC). However, in advanced NSCLC, the 5-year survival rate is below 10%, mainly due to resistance to therapy. We have previously shown that the fraction of mesenchymal-like, chemotherapy-resistant paraclone cells increased after MTA and cisplatin combination therapy in the NSCLC cell line A549. Cytidine deaminase (CDA) and thymidine phosphorylase (TYMP) are key enzymes of the pyrimidine salvage pathway. 5'-deoxy-5-fluorocytidine (5'-DFCR) is a cytidine analogue (metabolite of capecitabine), which is converted by CDA and subsequently by TYMP into 5-fluorouracil, a chemotherapeutic agent frequently used to treat solid tumors. The aim of this study was to identify and exploit chemotherapy-induced metabolic adaptations to target resistant cancer cells. Cell viability and colony formation assays were used to quantify the efficacy of MTA and cisplatin treatment in combination with schedule-dependent addition of 5'-DFCR on growth and survival of A549 paraclone cells and NSCLC cell lines. CDA and TYMP protein expression were monitored by Western blot. Finally, flow cytometry was used to analyze the EMT phenotype, DNA damage response activation and cell cycle distribution over time after treatment. CDA expression was measured by immunohistochemistry in tumor tissues of patients before and after neoadjuvant chemotherapy. We performed a small-scale screen of mitochondrial metabolism inhibitors, which revealed that 5'-DFCR selectively targets chemotherapy-resistant A549 paraclone cells characterized by high CDA and TYMP expression. In the cell line A549, CDA and TYMP expression was further increased by chemotherapy in a time-dependent manner, which was also observed in the KRAS-addicted NSCLC cell lines H358 and H411. The addition of 5'-DFCR on the second day after MTA and cisplatin combination therapy was the most efficient treatment to eradicate chemotherapy-resistant NSCLC cells. Moreover, recovery from treatment-induced DNA damage was delayed and accompanied by senescence induction and acquisition of a hybrid-EMT phenotype. In a subset of patient tumors, CDA expression was also increased after treatment with neoadjuvant chemotherapy. Chemotherapy increases CDA and TYMP expression thereby rendering resistant lung cancer cells susceptible to subsequent 5'-DFCR treatment

    CP violation in Bd,sl+lB_{d,s} \to l^+l^- in the model III 2HDM

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    We have calculated the Wilson coefficients C10,CQiC_{10}, C_{Q_i} (i=1,2) in the MSˉ\bar{MS} renormalization scheme in the model III 2HDM. Using the obtained Wilson coefficients, we have analyzed the CP violation in decays Bq0l+lB^0_q\to l^+l^- (q=d,s) in the model. The CP asymmetry, ACPA_{CP}, depends on the parameters of models and ACPA_{CP} in Bdl+lB_d\to l^+l^- can be as large as 40% and 35% for l=τl=\tau and l=μl=\mu respectively. It can reach 4% for Bs0B^0_s decays. Because in SM CP violation is smaller than or equal to O(10310^{-3}) which is unobservably small, an observation of CP asymmetry in the decays Bq0l+l(q=d,s)B^0_q \to l^+l^- (q=d,s) would unambiguously signal the existence of new physics.Comment: revtex4, 16 pages, 7 figure
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