Revealing quantum chaos with machine learning

Understanding properties of quantum matter is an outstanding challenge in science. In this paper, we demonstrate how machine-learning methods can be successfully applied for the classification of various regimes in single-particle and many-body systems. We realize neural network algorithms that perform a classification between regular and chaotic behavior in quantum billiard models with remarkably high accuracy. We use the variational autoencoder for autosupervised classification of regular/chaotic wave functions, as well as demonstrating that variational autoencoders could be used as a tool for detection of anomalous quantum states, such as quantum scars. By taking this method further, we show that machine learning techniques allow us to pin down the transition from integrability to many-body quantum chaos in Heisenberg XXZ spin chains. For both cases, we confirm the existence of universal W shapes that characterize the transition. Our results pave the way for exploring the power of machine learning tools for revealing exotic phenomena in quantum many-body systems.Comment: 12 pages, 12 figure

Minimizing total flow time under uncertainty using optimality and stability boxes

The stability method to the scheduling problem under un- certain (interval) processing times is investigated. The applied stability approach combines a stability analysis, a multi-stage decision framework, and a solution concept of a minimal dominant set of the job permutations

The Trusted UHF Receiver for Radio Frequency Identification of Critical Infrastructure Objects

Results of designing the low-noise amplifier, quadrature demodulator, and baseband amplifier with an integrated low-pass filter for the UHF radio frequency identification receiver are presented. IP-blocks are designed for implementation in the domestic CMOS 180 nm technology process. The low-noise amplifier is implemented with integrated single pole double throw switches based on the MOSFETs which are needed for bypass mode realization at the RF input. The benefits of this approach are increased input linearity of the receiver by no less than 30 dB with an increase of a noise figure. The quadrature demodulator is realized according to a typical design based on the passive MOSFET mixer core. The programmable-gain baseband amplifier is implemented with an integrated low-pass filter based on Tow-Thomas biquad architecture. IP-blocks designed for use in an RFID reader transceiver VLSI IC with sensitivity value no more than -75 dBm and input linearity value not less than 10 dBm in a «Talk» mode. The trustiness of the receiver is provided by the full-cycle design procedure and verification under experimental investigation. The electric parameters values of the proposed receiver correspond to foreign VLSIs implemented in a CMOS process with the same technology nodes. Thus, it is important to design the domestic ISO 18000-6C reader equipment intended for critical infrastructure

A new design for a green calcium indicator with a smaller size and a reduced number of calcium-binding sites

Genetically encoded calcium indicators (GECIs) are mainly represented by two- or one-fluorophore-based sensors. One type of two-fluorophore-based sensor, carrying Opsanus troponin C (TnC) as the Ca2+-binding moiety, has two binding sites for calcium ions, providing a linear response to calcium ions. One-fluorophore-based sensors have four Ca2+-binding sites but are better suited for in vivo experiments. Herein, we describe a novel design for a one-fluorophore-based GECI with two Ca2+-binding sites. The engineered sensor, called NTnC, uses TnC as the Ca2+-binding moiety, inserted in the mNeonGreen fluorescent protein. Monomeric NTnC has higher brightness and pH-stability in vitro compared with the standard GECI GCaMP6s. In addition, NTnC shows an inverted fluorescence response to Ca2+. Using NTnC, we have visualized Ca2+ dynamics during spontaneous activity of neuronal cultures as confirmed by control NTnC and its mutant, in which the affinity to Ca2+ is eliminated. Using whole-cell patch clamp, we have demonstrated that NTnC dynamics in neurons are similar to those of GCaMP6s and allow robust detection of single action potentials. Finally, we have used NTnC to visualize Ca2+ neuronal activity in vivo in the V1 cortical area in awake and freely moving mice using two-photon microscopy or an nVista miniaturized microscope

Endovascular revascularisation of lower limbs in a patient with dextrocardia and polymorbidity

Dextrocardia and situs inversus totalis are rare anatomical anomalies. We report the case of a 54-year woman with critical chronic lower limb ischemia, successfully treated by percutaneous transluminal angioplasty.В статье приводится успешный случай эндоваскулярной реваскуляризации нижних конечностей у полиморбидной пациентки 54 лет с аномалиями расположения внутренних органов – декстрокардией и situs inversus totalis. Балонная ангиопластика под местной анестезией может являться методом выбора при наличии критической ишемии нижних конечностей и выраженной сопутствующей патологии, которая накладывает ограничения на анестезиологическое пособие

Методика выделения стромально-васкулярной фракции из жировой ткани

The rapid development of regenerative medicine and cell biology is opening up new therapeutic options that will be available in the near future. Stem cells are of great interest due to their potential for tissue and organ repair. The article describes a protocol for the isolation of the stromal-vascular fraction by a mechanical method.Стремительное развитие регенеративной медицины и клеточной биологии открывает новые терапевтические возможности, которые будут доступны в ближайшем будущем. Стволовые клетки вызывают высокий интерес благодаря своему потенциалу к восстановлению тканей и органов. В статье описан протокол по выделению стромально-васкулярной фракции механическим методом

Angiography imaging of giant extracranial internal carotid aneurysm

Giant extracranial aneurysms of internal carotid artery are rare anatomical anomalies of magistral vessels. We report about 64-year female with giant (32x39 mm) aneurysm. She refused operative treatment and was dischargedВ статье представлен случай ангиографического наблюдения гигантской (32х39 мм) аневризмы экстракраниального отдела внутренней сонной артерии у пациентки 64 лет. После проведения ангиографии пациентке было предложено оперативное лечение, от которого она отказалась. Случай интересен демонстрацией редкой сосудистой аномали

Single machine scheduling problem with interval processing times and total completion time objective

We consider a single machine scheduling problem with uncertain durations of the given jobs. The objective function is minimization of the sum of job completion times. We apply astability approach to this uncertain scheduling problem. The stability approach combines a stability analysis of schedules (job permutations) and constructing a job permutationwith the largest stability (optimality) box. We consider a relative perimeter of the optimality box of the job permutation as a stability measure for this permutation. We investigated properties of the optimality box and developed algorithms for finding permutations with the largest relative perimeters of their optimality boxes

Stability polyhedra of optimal permutation of jobs servicing

Consideration was given to minimization of the sum of weighted instants of completing servicing of n customers by a single server, provided that the duration of jobs servicing may assume any real value from a given numerical interval. An algorithm of complexity O(n) was developed to construct a polyhedron (parallelepiped) of the optimality of permutation of servicing of n jobs that is contained in the domain of stability of the same permutation and comprises the polyhedron of its stability

Sequencing jobs with uncertain processing times and minimizing the weighted total flow time

We consider an uncertain version of the scheduling problem to sequence set of jobs J on a single machine with minimizing the weighted total flow time, provided that processing time of a job can take on any real value from the given closed interval. It is assumed that job processing time is unknown random variable before the actual occurrence of this time, where probability distribution of such a variable between the given lower and upper bounds is unknown before scheduling. We develop the dominance relations on a set of jobs J. The necessary and sufficient conditions for a job domination may be tested in polynomial time of the number n=|J| of jobs. If there is no a domination within some subset of set J, heuristic procedure to minimize the weighted total flow time is used for sequencing the jobs from such a subset