1,296 research outputs found
A modest artist’s place in history: The legacy of Mikhail Gurevich in the Smolensk gallery
No full textThe article is a study conducted in the framework of the scientific interests of the author:
the study of the history and theory of the Russian avant-garde in the Smolensk region. The
purpose of this study is to draw attention to the problem of the low level of knowledge of the
avant-garde heritage in the Smolensk region through the analysis of current events in the museum
and exhibition environment. The article discusses the exhibition “MG /Humble Artist/”,
held in the Art Gallery of Smolensk in February-March 2020. M. G. are the initials of the artist
Mikhail Gurevich who was born in Smolensk. Gurevich was a student of the famous David
Shterenberg, one of his best graduates and a representative of the creative galaxy of artists —
graduates of the Higher Art and Technical Institute. In addition to the analysis of the features
of Gurevich’s work, the role of the artist’s work in the cultural process of the USSR in the 1930s
is evaluated. The author also provides clarifications concerning the artist’s biography. The heritage
of the Russian avant-garde is an important component of the cultural heritage of Russia
and has great potential in the tourism sector. The work of the avant-garde era in the regions is
often not given due attention, but fortunately, this trend has changed in the last few years. Research
of this type will make it possible in the future to expand the knowledge base on the history
of Russian art, as well as expand the scope of scientific research in museums by creating
new exhibits. Therefore, support for research on the work of regional artists of the avant-garde
era, and coverage of events and activities that are the results of these studies, is very important
Specific heat investigation in high magnetic field of the magnetic ordering of the rare-earth lattice in RFeAsO: The case of Sm
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The M-Machine Operating System
No full textThis document details the design and implementation of an operating system written specifically for the M-Machine, a multicomputer currently being designed at MIT. The operating system is designed to be lightweight and flexible, able to support a UNIXlike operating system layer interface to higher-level code, while at the same time exposing machine primitives to user programs in a safe and efficient manner. The operating system's central features are its support for fast and efficient thread creation and built-in memory-coherence to present the view of global virtual memory to userlevel programs as well as higher-level protected subsystems. Four core components are presented - the physical and virtual memory managers, the thread manager, and the memory-coherence manager. Thesis Supervisor: William J. Dally Title: Associate Professor Acknowledgments My participation in the M-Machine project has involved the most exciting and challenging work that I have so far undertaken. I would lik..
The computable kernel of Abstract State Machines
No full textAbstractAbstract State Machines (ASMs) were introduced as “a computation model that is more powerful and more universal than standard computation models”, by Yuri Gurevich in 1985. ASMs gained much attention as a specification method. It is extremely flexible because any mathematical structure may serve as a state. Gurevich characterized the expressive power of ASMs in terms of intuitively convincing postulates.The core result of this paper shows that the next-state function M of an Abstract State Machine M can be described on a symbolic level, notwithstanding the generality of the model: The successor state M(S) of a state S is fully specified by the equivalence ∼S induced by S on the terms over the signature of M. Consequently, M(S) is computable in case ∼S is decidable. Furthermore, this result implies a notion of computability for general structures, e.g. for algorithms operating on real numbers
An Assembler and Linker System for the M-Machine Software Project
No full textThis document details the design and implementation of an assembler and linker, and the specifications of their input and output languages. The assembler and linker are system tools for the M-Machine - a multi-node parallel computer being developed at the MIT AI Lab's Concurrent VLSI Architecture Group. The assembler is a derivative of the Multiflow Assembler - a system tool written for computers of similar design to the M-Machine. The assembler/linker system and included specification of the M-Machine assembly-language and M-Machine object file format, provide a solid software base for building other system tools and user programs targeted for the M-Machine. Thesis Supervisor: William J. Dally Title: Associate Professor Acknowledgments I have a great many people to thank. First, to the many teachers and instructors who have made learning exciting for me: Mrs. Crich, Mrs. Stintson, Mrs. Budnick, Mrs. Romero, Mrs. Most, Mr. Mossa, Mrs. Kronen, Mr. Weinberg, Mr. Pullano, Mr. Orenstein..
Flux flow of Abrikosov-Josephson vortices along grain boundaries in high-temperature superconductors
No full textLow-angle grain boundaries (GBs) in superconductors exhibit intermediate Abrikosov vortices with
Josephson cores, whose length l along GB is smaller than the London penetration depth, but larger than
the coherence length. We found an exact solution for a periodic vortex structure moving along GBs
in a magnetic field H and calculated the flux flow resistivity RFH, and the nonlinear voltage-current
characteristics. The predicted RFH dependence describes well our experimental data on 7± unirradiated
and irradiated YBa2Cu3O7 bicrystals, from which the core size lT, and the intrinsic depairing density
JbT on nanoscales of a few GB dislocations were measured for the first time. The observed J_bT=
J_b01 (T-Tc)^2 indicates a significant order parameter suppression on GB
Ferromagnetic glass-coated microwires for cell manipulation
No full textThe application of magnetic nanoparticles allows labeling the cell for its manipulation via the external magnetic field. In this work, it is proposed to use glass-coated magnetic microwires as a magnetic pin system to create a strong and well-localized magnetic field at the end of such microwires. Magnetic microwires manufactured by the Taylor − Ulitovsky method exhibit tunable magnetic properties correlated with their unique micromagnetic structure. The control of magnetic properties can be achieved by, for example, the chemical composition of the wire: Fe-based microwire shows bistable hysteresis and thus strong stray fields at the ends, while Co-based one demonstrates S-shaped hysteresis with almost zero remanent magnetization because of a closed domain structure. In this research, we discovered by theoretical calculation and experiments the usability of both kinds of microwires for different approaches of cell manipulations
G Protein-Coupled Receptor Signaling Cascade
No full textG protein-coupled receptors (GPCRs) are seven-transmembrane proteins expressed in virtually every human cell. GPCRs are activated by extracellular endogenous and exogenous ligands including ions, small molecules, neurotransmitters, peptides, proteins, and other sensory inputs. The binding of an agonist (a peptide displayed here in green) causes conformational changes in the GPCR (Rasmussen et al., 2011) (1) leading to activation and coupling to membrane-anchored heterotrimeric G proteins. Exchange of GDP to GTP leads (2) to Gα (brown) and Gβγ (red and cyan, respectively) subunit dissociation, which independently activates further downstream signaling by second messengers such as cAMP, IP1/3 and Ca2+ (3) (Senarath et al., 2018). The Gαβγ heterotrimer is then reassembled after hydrolysis of GTP to GDP. GPCR kinases phosphorylate the activated receptor and, thus, recruit arrestins (4) promoting desensitization and internalization, which leads to downregulation of receptor activity within minutes or hours (Smith et al., 2018). Arrestins can further trigger additional signaling pathways (Gurevich & Gurevich, 2019).
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Gurevich, V. V., & Gurevich, E. V. (2019). GPCR Signaling Regulation: The Role of GRKs and Arrestins. Frontiers in Pharmacology, 10, 125. https://doi.org/10.3389/fphar.2019.00125
Rasmussen, S. G. F., DeVree, B. T., Zou, Y., Kruse, A. C., Chung, K. Y., Kobilka, T. S., Thian, F. S., Chae, P. S., Pardon, E., Calinski, D., Mathiesen, J. M., Shah, S. T. A., Lyons, J. A., Caffrey, M., Gellman, S. H., Steyaert, J., Skiniotis, G., Weis, W. I., Sunahara, R. K., & Kobilka, B. K. (2011). Crystal structure of the β2 adrenergic receptor-Gs protein complex. Nature, 477(7366), 549–555. https://doi.org/10.1038/nature10361
Senarath, K., Kankanamge, D., Samaradivakara, S., Ratnayake, K., Tennakoon, M., & Karunarathne, A. (2018). Regulation of G Protein βγ Signaling. International Review of Cell and Molecular Biology, 339, 133–191. https://doi.org/10.1016/BS.IRCMB.2018.02.008
Smith, J. S., Lefkowitz, R. J., & Rajagopal, S. (2018). Biased signalling: from simple switches to allosteric microprocessors. Nature Reviews Drug Discovery, 17(4), 243–260. https://doi.org/10.1038/nrd.2017.22
A Reactive Environment for Dynamic Volume Control
Get PDFEl-Shimy D, Hermann T, Cooperstock J. A Reactive Environment for Dynamic Volume Control. In: Essl GE, Gillespie B, Gurevich M, O'Modhrain S, eds. Proceedings of the International Conference on New Interfaces for Musical Expression (NIME). Ann Arbor, Michigan: University of Michigan; 2012.In this paper, we discuss the design and testing of a reactive envi- ronment for musical performance. Driven by the interpersonal interactions amongst musicians, our system gives users, i.e., several musicians playing together in a band, real-time control over certain aspects of their performance, enabling them to change volume levels dynamically simply by moving around. It differs most notably from the majority of ventures into the design of novel musical interfaces and installations in its multidisciplinary approach, drawing on techniques from Human-Computer Interaction, social sciences and ludology. Our User-Centered Design methodology was central to producing an interactive environment that enhances traditional performance with novel functionalities. During a formal experiment, musicians reported finding our system exciting and enjoyable. We also introduce some additional interactions that can further enhance the interactivity of our reactive environment. In describing the particular challenges of working with such a unique and creative user as the musician, we hope that our approach can be of guidance to interface developers working on applications of a creative nature
Ionospheric electron heating, optical emissions, and striations induced by powerful HF radio waves at high latitudes: Aspect angle dependence
Get PDFIn recent years, large electron temperature increases of 300% (3000 K above background) caused by powerful HF-radio wave injection have been observed during nighttime using the EISCAT incoherent scatter radar near Tromsø in northern Norway. In a case study we examine the spatial structure of the modified region. The electron heating is accompanied by ion heating of about 100 degrees and magnetic field-aligned measurements show ion outflows increasing with height up to 300 m s−1 at 582 km. The electron density decreases by up to 20%. When the radar antenna was scanned between three elevations from near field-aligned to vertical, the strongest heating effects were always obtained in the field-aligned position. When the HF-pump beam was scanned between the same three positions, the heating was still almost always strongest in the field-aligned direction. Simultaneous images of the 630 nm O(1D) line in the radio-induced aurora showed that the enhancement caused by the HF radio waves also remained localized near the field-aligned position. Coherent HF radar backscatter also appeared strongest when the pump beam was pointed field-aligned. These results are similar to some Langmuir turbulence phenomena which also show a strong preference for excitation by HF rays launched in the field-aligned direction. The correlation of the position of largest temperature enhancement with the position of the radio-induced aurora suggests that a common mechanism, upper-hybrid wave turbulence, is responsible for both effects. Why the strongest heating effects occur for HF rays directed along the magnetic field is still unclear, but self-focusing on field-aligned striations is a candidate mechanism, and possibly ionospheric tilts may be important
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