Output spectrum of a detector measuring quantum oscillations

We consider a two-level quantum system (qubit) which is continuously measured by a detector and calculate the spectral density of the detector output. In the weakly coupled case the spectrum exhibits a moderate peak at the frequency of quantum oscillations and a Lorentzian-shape increase of the detector noise at low frequency. With increasing coupling the spectrum transforms into a single Lorentzian corresponding to random jumps between two states. We prove that the Bayesian formalism for the selective evolution of the density matrix gives the same spectrum as the conventional master equation approach, despite the significant difference in interpretation. The effects of the detector nonideality and the finite-temperature environment are also discussed.Comment: 8 pages, 6 figure

Primary accumulation in the Soviet transition

The Soviet background to the idea of primary socialist accumulation is presented. The mobilisation of labour power and of products into public sector investment from outside are shown to have been the two original forms of the concept. In Soviet primary accumulation the mobilisation of labour power was apparently more decisive than the mobilisation of products. The primary accumulation process had both intended and unintended results. Intended results included bringing most of the economy into the public sector, and industrialisation of the economy as a whole. Unintended results included substantial economic losses, and the proliferation of coercive institutions damaging to attainment of the ultimate goal - the building of a communist society

Study of KS KL Coupled Decays and KL -Be Interactions with the CMD-2 Detector at VEPP-2M Collider

The integrated luminosity about 4000 inverse nanobarn of around phi meson mass ( 5 millions of phi mesons) has been collected with the CMD-2 detector at the VEPP-2M collider. A latest analysis of the KS KL coupled decays based on 30 % of available data is presented in this paper. The KS KL pairs from phi meson decays were reconstructed in the drift chamber when both kaons decayed into two charged particles. From a sample of 1423 coupled decays a selection of candidates to the CP violating KL into pi+ pi- decay was performed. CP violating decays were not identified because of the domination of events with a KL regenerating at the Be beam pipe into KS and a background from KL semileptonic decays. The regeneration cross section of 110 MeV/c KL mesons was found to be 53 +- 17 mb in agreement with theoretical expectations. The angular distribution of KS mesons after regeneration and the total cross section of KL for Be have been measured.Comment: 14 pages, 8 figure

Selective quantum evolution of a qubit state due to continuous measurement

We consider a two-level quantum system (qubit) which is continuously measured by a detector. The information provided by the detector is taken into account to describe the evolution during a particular realization of measurement process. We discuss the Bayesian formalism for such ``selective'' evolution of an individual qubit and apply it to several solid-state setups. In particular, we show how to suppress the qubit decoherence using continuous measurement and the feedback loop.Comment: 15 pages (including 9 figures

The Unitary Gas and its Symmetry Properties

The physics of atomic quantum gases is currently taking advantage of a powerful tool, the possibility to fully adjust the interaction strength between atoms using a magnetically controlled Feshbach resonance. For fermions with two internal states, formally two opposite spin states, this allows to prepare long lived strongly interacting three-dimensional gases and to study the BEC-BCS crossover. Of particular interest along the BEC-BCS crossover is the so-called unitary gas, where the atomic interaction potential between the opposite spin states has virtually an infinite scattering length and a zero range. This unitary gas is the main subject of the present chapter: It has fascinating symmetry properties, from a simple scaling invariance, to a more subtle dynamical symmetry in an isotropic harmonic trap, which is linked to a separability of the N-body problem in hyperspherical coordinates. Other analytical results, valid over the whole BEC-BCS crossover, are presented, establishing a connection between three recently measured quantities, the tail of the momentum distribution, the short range part of the pair distribution function and the mean number of closed channel molecules.Comment: 63 pages, 8 figures. Contribution to the Springer Lecture Notes in Physics "BEC-BCS Crossover and the Unitary Fermi gas" edited by Wilhelm Zwerger. Revised version correcting a few typo

Special features of pulsed photon annealing of indium antimonide

Translated from Russian (Fiz. Khim. Obrab. Mater. 1988 v. 22(1) p. 34-38)Available from British Library Document Supply Centre- DSC:9023.19(Vr-Trans--4029)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Gastrointestinal tract in children with novel coronavirus infection and post-COVID-19 syndrome. The role of synbiotics for improving clinical symptoms, gut microbiota, and intestinal permeability

V.P. Novikova1, A.V. Polunina1, S.L. Bannova1, A.L. Balashov1,2, V.V. Dudurich3, L.G. Danilov3, A.E. Blinov1, O.N. Varlamova1 1St. Petersburg State Pediatric Medical University, St. Petersburg, Russian Federation 2City Polyclinics No. 56, St. Petersburg, Russian Federation 3CerbaLab Ltd, St. Petersburg, Russian Federation Background: studying the consequences of novel coronavirus infection is currently relevant. Many observations demonstrate that SARS-CoV-2 affects the gastrointestinal tract, gut microbiota composition, and intestinal permeability. Aim: to assess whether Maxilac® Baby synbiotic effects qualitative and quantitative composition of gut microbiota and intestinal permeability in children aged 3–14 with mild-to-moderate COVID-19. Patients and Methods: an open, observational, prospective, single-center study with minimal intervention was conducted. Group 1 included 16 children who received Maxilac® Baby 4 weeks after recovery. Group 2 children did not receive synbiotics after recovery. History and complaints were assessed, gut microbiome composition was determined, and fecal zonulin was measured at disease onset, time of recovery (day 14), and 4 weeks after recovery. Results: at disease onset, abdominal pain and diarrhea were reported in 16 children (50%), nausea in 8 children (25%), and vomiting in 1 child (3.1%). At the time of recovery, only abdominal pain was reported in both groups (4 patients each). Thirty days after recovery, re-appearance of intestinal symptoms was reported in group 2. No significant differences in the microbiome diversity profile at birth level were revealed between children with the COVID-19 at onset and healthy age-matched children. Taxa (species) whose predominance was typical for each group were identified. Conclusions: post-COVID-19 syndrome in children aged 3–14 diagnosed with mild-to-moderate disease who received Maxilac® Baby for 1 month after recovery is characterized by the lack of nausea, vomiting, and diarrhea, less abdominal pain, no changes in fecal zonulin levels, and biodiversity of gut microbiome, including those assessed by Shannon diversity index. Keywords: SARS-CoV-2, COVID-19, intestinal permeability, gut microbiome, 16s rRNA sequencing, zonulin, novel coronavirus infection, post-COVID-19 syndrome. For citation: Novikova V.P., Polunina A.V., Bannova S.L., Balashov A.L., Dudurich V.V., Danilov L.G., Blinov A.E., Varlamova O.N. Gastrointestinal tract in children with novel coronavirus infection and post-COVID-19 syndrome. The role of synbiotics for improving clinical symptoms, gut microbiota, and intestinal permeability. Russian Journal of Woman and Child Health. 2023;6(3):283–289 (in Russ.). DOI: 10.32364/2618-8430-2023-6-3-10. </p