97 research outputs found

    On the Finiteness Problem for Automaton (Semi)groups

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    This paper addresses a decision problem highlighted by Grigorchuk, Nekrashevich, and Sushchanskii, namely the finiteness problem for automaton (semi)groups. For semigroups, we give an effective sufficient but not necessary condition for finiteness and, for groups, an effective necessary but not sufficient condition. The efficiency of the new criteria is demonstrated by testing all Mealy automata with small stateset and alphabet. Finally, for groups, we provide a necessary and sufficient condition that does not directly lead to a decision procedure

    Разработка механизма адаптивной маршрутизации трафика в программно-конфигурируемых сетях

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    The purpose of this work is to develop a unitary mechanism of adaptive routing of different kinds, basing on the current requirements on the quality of service. The software configuration of a network is the technology of the future. The trend in communication systems constantly confirms this fact. However, the application of this technology in its current form is justified only in large networks of technology giants and telecom operators. Today we have a large number of dynamic routing protocols to route big volume traffic in communication networks. Our task is to create the solution that can use the opportunities of each node to make a decision on the transmission of information by all possible means for each type of traffic. Achieving this goal is possible by solving the problem of the development of generalized metrics, which details the links between devices in the network, and the problem of establishing a framework of adaptive logical network topology (route management) to ensure the quality of the whole network in order to meet the current requirements on the quality of a particular type service.Цель данной работы – разработать единый механизм адаптивной маршрутизации трафика различного рода, опираясь на текущие требования к качеству предоставления сервисов.Программное конфигурирование сети – это технологии будущего. Современная тенденция развития систем связи постоянно подтверждает этот факт. Однако на сегодняшний день применение этой технологии в ее текущем виде оправдано лишь в больших сетях технологических гигантов и операторов связи. К настоящему времени создано большое количество динамических протоколов маршрутизации трафика в сетях связи. Наша задача создать такое решение, которое сможет использовать возможности каждого узла принимать решение о передаче информации всеми возможными способами для каждого типа трафика. Достижение поставленной цели возможно путем решения задачи разработки обобщенной метрики, подробно характеризующей каналы связи между устройствами в сети, и задачи разработки механизма адаптивного перестроения логической топологии сети (управления маршрутами) для обеспечения качественной работы всей сети в целях удовлетворения текущим требованиям к качеству предоставления того или иного вида сервиса

    Use of horseradish peroxidase for gene-directed enzyme prodrug therapy with paracetamol

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    Gene therapy is a potential method of treating cancer with a greater degree of targeting than conventional therapies. In addition, therapy can be directed towards cells within the tumour population that are traditionally resistant to current treatment schedules. Horseradish peroxidase (HRP) can oxidise paracetamol to N-acetyl-p-benzoquinoneimine via a one-electron pathway. Incubation of human cells expressing HRP with 0.5–10 mm paracetamol reduced clonogenic survival, but had little effect on control cells. A small increase in apoptosis was seen and a decrease in the number of cells undergoing mitosis, consistent with reports in hepatocytes using higher paracetamol concentrations. The cytotoxicity was also seen under conditions of severe hypoxia (catalyst induced anoxia), indicating that the HRP/paracetamol combination may be suitable for hypoxia-targeted gene therapy

    Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

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    We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

    Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

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    Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

    Spatial interrelations in the placement of woody plants in the middle taiga virgin spruce forests of the upper reaches of the Pechora river

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    Investigation was carried out in virgin spruce forests in the upper reaches of the Pechora river in middle taiga condition. It was show that spruce forests of different types are characterized by common features of the structure of stands and undergrowth. There was a large variability of trees in volume of stem and undergrowth height. Investigated stands formed a cyclical-multi-age type of age structure. The calculated data obtained using spatial statistics and analyses of point processes were presented. It was found that in spruce forests is expressed regardless of forest types, the group distribution of young individuals of woody plants, which passes into random distribution at more late stages of generation. The spatial relationships between woody plants tested using the cross-correlation function gij(r) show that the undergrowth is attracted to each other at distances of up to 1 meter. There were no spatial interrelation between the undergrowth and the trees. Trees demonstrated independent from each other placement in the area. The density of trees in the area and their phytosocial status are determining the intensity of competitive relations between woody plants in the indigenous spruce communities of the upper reaches of the Pechora River
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