78 research outputs found
Normalizers of maximal tori and real forms of Lie groups
For a complex reductive Lie group Tits defined an extension of
the corresponding Weyl group . The extended group is supplied with an
embedding into the normalizer of the maximal torus such
that together with generate . We give an interpretation of
the Tits classical construction in terms of the maximal split real form
, leading to a simple topological
description of . We also propose a different extension of the
Weyl group associated with the compact real form . This results into a presentation of the normalizer of maximal
torus of the group extension by the
Galois group . We also describe explicitly
the adjoint action of and on the Lie algebra of .Comment: 17 page
Dynamic Path Planning for a 7-DOF Robot Arm
Klanke S, Lebedev DV, Haschke R, Steil JJ, Ritter H. Dynamic Path Planning for a 7-DOF Robot Arm. In: Int. Conf. Intelligent Robots and Systems. IEEE; 2006: 3879-3884
Collection and processing of environmental information in oil and gas production areas and solving other applied problems using active search methods (Review article)
The methods of monitoring the environmental situation as well as the problems of solving related applied environmental
and resource problems in hard-to-reach areas of oil and gas production and also in other sectors of the national economy
using unmanned aerial vehicles, are investigated. The methods of studying the types and thicknesses of the layers of
the underlying surface by probing them with electromagnetic pulses of the radiofrequency range and gamma radiation
are considered. Based on the existing theoretical dependencies of the interaction of electromagnetic radiation with the
Earth’s surface, diagrams of the passage of electromagnetic waves in the decimeter and centimeter ranges through various
landscape structures (snow-ice-water-frozen soil) are presented. It is shown that the use of gamma radiation makes it
possible to solve the problem of determining the effective altitude of an aircraft during environmental monitoring due
to the high energy of photon radiation and albedo from various surfaces including snow cover. A method for calculating
the pollutant content on the underlying surface with a given probability of its reliable detection is presented. It is noted
that the reliability of the readings of measuring instruments is significantly influenced by their geometric location on
the transport platform. It is shown that the proposed solution is advisable to implement using two unmanned aerial
vehicles or as mall-sized unmanned airship. Based on the review, the composition of the technical means of the complex
for recognizing the types and thicknesses of layers of contamination of the underlying surface is proposed. A possible
methodology for assessing the environmental situation is presented. The results of the work can be used in conducting
environmental exploration of infrastructure used for transporting oil and gas resources in conditions of difficult access
to it as well as for solving similar military-applied and engineering-construction tasks. At the same time, for the first
time, the joint use of the radio frequency range of electromagnetic waves and gamma radiation was proposed. The radio
frequency range makes it possible to study the structure of the landscape, and gamma radiation from backscattered
ionizing radiation is a type of pollutant, as well as to ensure high accuracy in measuring the distance from the module
to the upper layer of the underlying surface
Problems of personnel irradiation in modern medical technologies
BACKGROUND: The widespread use of radiation sources in medical practice (cardio-endovascular surgery, endoscopy, traumatology, urology, neurosurgery, dentistry, and radioisotope diagnostics departments) leads to irradiation of the lens of the eye and the skin of the hands. The introduction of new recommendations by the IAEA to reduce the limit of the annual equivalent dose to the lens (20 mSv) has led to an inaccurate dose assessment based on the effective dose.
AIM: To analyze approaches and assess equivalent doses of irradiation of the lens of the eye and skin of the hands of medical personnel during various diagnostic studies under the influence of X-rays and radiopharmaceuticals studies and to compare the results obtained with previously published data.
MATERIALS AND METHODS: Thermo-luminescent dosimetry was used. Dose assessment was performed by cardio-endovascular surgery, endoscopy, isotope diagnostics, dentistry, and urology personnel.
RESULTS: The estimated annual equivalent doses to the lens of the eye for doctors of cardio-endovascular surgery departments, in most cases, ranging 3590 mSv, 619 mSv for the average medical staff (in some cases, the doctor [225 mSv] and the nurse [180 mSv]) and 4.59 mSv for the staff of the department of radioisotope diagnostics. The annual calculated equivalent doses to the skin of the hands for cardio-endovascular surgery personnel were 17100 and 24220 mSv for the staff working with radiopharmaceuticals. It is shown that the use of an estimate of the average dose per operation by cardio-endovascular surgery doctors, as a rule, inevitably leads to an excess of the equivalent dose to the lens of the eye after a certain number of operations.
CONCLUSION: When a certain number of operations are exceeded (100200), equivalent doses to the eyes lens in cardio-endovascular surgery doctors above 20 mSv per year can be formed. At current radiation levels, a lesion of the eyes lens was found in a cardio-endovascular surgery doctor. The results indicate the need for further dosimetric measurements and epidemiological studies, based on which recommendations for radiation protection of the eyes lens and the skin of the hands of medical personnel working in low-intensity, scattered, gamma X-ray radiation can be developed
Желудочковая экстрасистолия у детей
The article presents updated data on the problem of premature ventricular contractions in children based on the clinical guidelines of the Russian Society of Cardiology and the Union of Pediatricians of Russia for the diagnosis, treatment and management of pediatric patients with premature ventricular contraction. The issues of diagnosis and treatment based on the principles of evidence-based medicine as well as important aspects of prevention of exacerbations and follow-up have been clarified in detail. The criteria for assessing the quality of care for patients with premature ventricular contractions have been presented.CONFLICT OF INTEREST. Not declared.В статье изложены обновленные данные о проблеме желудочковых экстрасистолий у детей, основанные на клинических рекомендациях Ассоциации детских кардиологов России и Союза педиатров России по диагностике, лечению и ведению пациентов детского возраста с желудочковой экстрасистолией. Подробно освещены вопросы диагностики, лечения, основанные на принципах доказательной медицины, а также важные аспекты профилактики обострений болезни и диспансерного наблюдения. Отображены критерии оценки качества медицинской помощи пациентам с желудочковыми экстрасистолиями.Публикация является обновленным вариантом клинических рекомендаций Ассоциации детских кардиологов России и Союза педиатров России по диагностике, лечению и ведению пациентов детского возраста с желудочковой экстрасистолией, опубликованных на сайте https://medi.ru/klinicheskie-rekomendatsii/zheludochkovaya-ekstrasistoliya-u-detej_14366/Авторы подтверждают отсутствие конфликта интересов, который необходимо обнародовать
Electric dipole moments and the search for new physics
Static electric dipole moments of nondegenerate systems probe mass scales for
physics beyond the Standard Model well beyond those reached directly at high
energy colliders. Discrimination between different physics models, however,
requires complementary searches in atomic-molecular-and-optical, nuclear and
particle physics. In this report, we discuss the current status and prospects
in the near future for a compelling suite of such experiments, along with
developments needed in the encompassing theoretical framework.Comment: Contribution to Snowmass 2021; updated with community edits and
endorsement
Transversal Stiffness and Young's Modulus of Single Fibers from Rat Soleus Muscle Probed by Atomic Force Microscopy
The structural integrity of striated muscle is determined by extra-sarcomere cytoskeleton that includes structures that connect the Z-disks and M-bands of a sarcomere to sarcomeres of neighbor myofibrils or to sarcolemma. Mechanical properties of these structures are not well characterized. The surface structure and transversal stiffness of single fibers from soleus muscle of the rat were studied with atomic force microscopy in liquid. We identified surface regions that correspond to projections of the Z-disks, M-bands, and structures between them. Transversal stiffness of the fibers was measured in each of these three regions. The stiffness was higher in the Z-disk regions, minimal between the Z-disks and the M-bands, and intermediate in the M-band regions. The stiffness increased twofold when relaxed fibers were maximally activated with calcium and threefold when they were transferred to rigor (ATP-free) solution. Transversal stiffness of fibers heavily treated with Triton X-100 was about twice higher than that of the permeabilized ones, however, its regional difference and the dependence on physiological state of the fiber remained the same. The data may be useful for understanding mechanics of muscle fibers when it is subjected to both axial and transversal strain and stress
The dynamic wave expansion neural network model for robot motion planning in time-varying environments
Lebedev DV, Steil JJ, Ritter H. The dynamic wave expansion neural network model for robot motion planning in time-varying environments. Neural Networks. 2005;18(3):267-285
A Neural Network Model that Calculates Dynamic Distance Transform for Path Planning and Exploration in a Changing Environment
Lebedev DV, Steil JJ, Ritter H. A Neural Network Model that Calculates Dynamic Distance Transform for Path Planning and Exploration in a Changing Environment. In: Proc. IEEE Int. Conf. on Robotics and Automation. 2003: 4209-4214
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