403 research outputs found

    Water metabolism regulating mechanisms in hypokinesia

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    The range of daily fluctuations of the proportion of the amount of consumed water and its content in the body was evaluated by means of a water metabolism regulation factor. This index constitutes a relative measure of fluctuations of the constant of tritium water elimination from the body per 24 hours. It is established that under conditions of long term hypokinesia regulation of water metabolism is disturbed both in humans and in animals. Still more marked changes are observed 2 to 3 weeks after restoration of motor activity. The shifts noted are evidence of general biological regularity of disturbance of regulation systems in long term restriction of motor activity and in the early restoration period

    Asymptotics for the number of n-quasigroups of order 4

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    The asymptotic form of the number of n-quasigroups of order 4 is 3n+122n+1(1+o(1))3^{n+1} 2^{2^n +1} (1+o(1)). Keywords: n-quasigroups, MDS codes, decomposability, reducibility.Comment: 15 p., 3 fi

    On unbalanced Boolean functions with best correlation immunity

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    It is known that the order of correlation immunity of a nonconstant unbalanced Boolean function in nn variables cannot exceed 2n/3−12n/3-1; moreover, it is 2n/3−12n/3-1 if and only if the function corresponds to an equitable 22-partition of the nn-cube with an eigenvalue −n/3-n/3 of the quotient matrix. The known series of such functions have proportion 1:31:3, 3:53:5, or 7:97:9 of the number of ones and zeros. We prove that if a nonconstant unbalanced Boolean function attains the correlation-immunity bound and has ratio C:BC:B of the number of ones and zeros, then CBCB is divisible by 33. In particular, this proves the nonexistence of equitable partitions for an infinite series of putative quotient matrices. We also establish that there are exactly 22 equivalence classes of the equitable partitions of the 1212-cube with quotient matrix [[3,9],[7,5]][[3,9],[7,5]] and 1616 classes, with [[0,12],[4,8]][[0,12],[4,8]]. These parameters correspond to the Boolean functions in 1212 variables with correlation immunity 77 and proportion 7:97:9 and 1:31:3, respectively (the case 3:53:5 remains unsolved). This also implies the characterization of the orthogonal arrays OA(1024,12,2,7)(1024,12,2,7) and OA(512,11,2,6)(512,11,2,6).Comment: v3: final; title changed; revised; OA(512,11,2,6) discusse

    On the structure of non-full-rank perfect codes

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    The Krotov combining construction of perfect 1-error-correcting binary codes from 2000 and a theorem of Heden saying that every non-full-rank perfect 1-error-correcting binary code can be constructed by this combining construction is generalized to the qq-ary case. Simply, every non-full-rank perfect code CC is the union of a well-defined family of μ\mu-components KμK_\mu, where μ\mu belongs to an "outer" perfect code C∗C^*, and these components are at distance three from each other. Components from distinct codes can thus freely be combined to obtain new perfect codes. The Phelps general product construction of perfect binary code from 1984 is generalized to obtain μ\mu-components, and new lower bounds on the number of perfect 1-error-correcting qq-ary codes are presented.Comment: 8 page

    Changes of some blood indices and myocardial electrolyte content during hypokinesia

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    Using special hypokinetic cages, the volume changes of circulating blood, its hematocrit and protein content, volume ratios between extra- and intracellular liquids in the body, as well as electrolyte content in the blood and myocardium during hypokinesia were investigated experimentally in rabbits

    Smooth optimal control with Floquet theory

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    This paper describes an approach to construct temporally shaped control pulses that drive a quantum system towards desired properties. A parametrization in terms of periodic functions with pre-defined frequencies permits to realize a smooth, typically simple shape of the pulses; their optimization can be performed based on a variational analysis with Floquet theory. As we show with selected specific examples, this approach permits to control the dynamics of interacting spins, such that gate operations and entanglement dynamics can be implemented with very high accuracy
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