118 research outputs found

    Correlating matched-filter model for analysis and optimisation of neural networks

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    A new formalism is described for modelling neural networks by means of which a clear physical understanding of the network behaviour can be gained. In essence, the neural net is represented by an equivalent network of matched filters which is then analysed by standard correlation techniques. The procedure is demonstrated on the synchronous Little-Hopfield network. It is shown how the ability of this network to discriminate between stored binary, bipolar codes is optimised if the stored codes are chosen to be orthogonal. However, such a choice will not often be possible and so a new neural network architecture is proposed which enables the same discrimination to be obtained for arbitrary stored codes. The most efficient convergence of the synchronous Little-Hopfield net is obtained when the neurons are connected to themselves with a weight equal to the number of stored codes. The processing gain is presented for this case. The paper goes on to show how this modelling technique can be extended to analyse the behaviour of both hard and soft neural threshold responses and a novel time-dependent threshold response is described

    Aerosolized Amiloride for the Treatment of Lung Disease in Cystic Fibrosis

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    To the Editor: The April 26 issue of the Journal presented encouraging results by Knowles et al. regarding the beneficial effects of aerosolized amiloride in the treatment of cystic fibrosis.1 The introduction and discussion sections of this article described the function of amiloride as an inhibitor of sodium transport in the airway epithelium, and the authors suggested that the beneficial effects observed were exerted “at least in part by increasing the clearance of secretions.” Although the results of this investigation were promising in terms of the improvement in the decline of forced vital capacity in patients with cystic fibrosis, this

    Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays

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    Average charged multiplicities have been measured separately in bb, cc and light quark (u,d,su,d,s) events from Z0Z^0 decays measured in the SLD experiment. Impact parameters of charged tracks were used to select enriched samples of bb and light quark events, and reconstructed charmed mesons were used to select cc quark events. We measured the charged multiplicities: nˉuds=20.21±0.10(stat.)±0.22(syst.)\bar{n}_{uds} = 20.21 \pm 0.10 (\rm{stat.})\pm 0.22(\rm{syst.}), nˉc=21.28±0.46(stat.)0.36+0.41(syst.)\bar{n}_{c} = 21.28 \pm 0.46(\rm{stat.}) ^{+0.41}_{-0.36}(\rm{syst.}) nˉb=23.14±0.10(stat.)0.37+0.38(syst.)\bar{n}_{b} = 23.14 \pm 0.10(\rm{stat.}) ^{+0.38}_{-0.37}(\rm{syst.}), from which we derived the differences between the total average charged multiplicities of cc or bb quark events and light quark events: Δnˉc=1.07±0.47(stat.)0.30+0.36(syst.)\Delta \bar{n}_c = 1.07 \pm 0.47(\rm{stat.})^{+0.36}_{-0.30}(\rm{syst.}) and Δnˉb=2.93±0.14(stat.)0.29+0.30(syst.)\Delta \bar{n}_b = 2.93 \pm 0.14(\rm{stat.})^{+0.30}_{-0.29}(\rm{syst.}). We compared these measurements with those at lower center-of-mass energies and with perturbative QCD predictions. These combined results are in agreement with the QCD expectations and disfavor the hypothesis of flavor-independent fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters

    Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF

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    The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at the Fermilab Long-Baseline Neutrino Facility (LBNF) is described

    A Pilot Study of Aerosolized Amiloride for the Treatment of Lung Disease in Cystic Fibrosis

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    Excessive active absorption of sodium is a unique abnormality of the airway epithelium in patients with cystic fibrosis. This defect is associated with thickened mucus and poor clearance of airway secretions and may contribute to the pulmonary disease in these patients. To study whether the inhibition of excessive absorption of sodium might affect the course of lung disease in cystic fibrosis, we performed a double-blind, crossover trial comparing aerosolized amiloride (5 mmol per liter; 3.5 ml four times daily), a sodium-channel blocker, with vehicle alone. Fourteen of the 18 adult patients initially enrolled in the study completed the one-year trial (25 weeks for each treatment). The mean (±SEM) loss of forced vital capacity (FVC) was reduced from 3.39±1.13 ml per day during treatment with vehicle alone to 1.44±0.67 ml per day during treatment with amiloride (P<0.04). A measured index of sputum viscosity and elasticity was abnormal during treatment with vehicle alone and improved during treatment with amiloride. Calculated indexes of mucociliary and cough clearance also improved during amiloride treatment. No systemic, respiratory, or subjective toxic effects of amiloride were noted. We conclude from this preliminary study that aerosolized amiloride can be safely administered to adults with cystic fibrosis. The slowing of the loss of FVC and the improvement in sputum viscosity and elasticity suggest a beneficial clinical effect. Aerosolized amiloride deserves further evaluation in the treatment of lung disease in patients with cystic fibrosis
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