3,203 research outputs found
Pattern Transitions in Unstable Viscous Convective Medium
Convection in a thin layer of liquid (gas) with temperature dependent
viscosity between poorly heat conducting boundaries is studied within framework
of the Proctor-Sivashinsky model. This model is examined in order to study both
the flow pattern formation and the second-order structural phase transitions as
between patterns with translational invariance as well as between structures
with broken translational invariance but keeping a long-range order. The
spatial spectrum of arising patterns and estimation of their visual
defectiveness are analyzed. The relation between the density of pattern defects
and spectral characteristics of the pattern is found. We also discuss the noise
effects on the formation of pattern defects. The influence of temperature
dependence of viscosity on the process of pattern formation and structure
transformations is also discussed. It is shown that the temperature dependence
of viscosity inhibits structural transition from regular rolls to square cells
Epistemic Access to Abstract Objects: Analysis Strategy for Neural Representations
В работе рассмотрена возможность применения стратегии исследований нейронных репрезентаций абстрактного для работы с проблемой эпистемического доступа к абстрактным объектам. Приводятся примеры результатов нейронаучных исследований, которые имеют значимые следствия для анализа этой проблемы. Указывается, что понимание абстрактного в рамках нейронаук и в рамках философии отличается. Это означает, что для применения стратегии анализа нейронных репрезентаций нужны результаты нейроисследований абстрактного в философском значении этого понятия.I investigate the adoption of neural representations analysis strategy to deal with the problem of epistemic access to abstract objects. I present some data obtained by neuroscience researchers that may have significant philosophical implications for dealing with the problem. I argue that the neuroscientific meaning of the concept of abstract differs from the meaning this concept has gained in philosophy. It means that the neural representation analysis strategy will not be applied to the philosophical problem unless the neuroscientific data of what abstract means in the philosophical sense of this concept are obtained
Use of open electronic courses in educational activity
The use of open electronic courses is a relatively new tendency in education and it is not yet fully discovered by researchers. With its introduction a change in the structure of the educational system happens. Therefore, the article studies the specifics of the introduction of online courses, including requirements to them, as well as factors that slow down their active development. Due to it, the following methods of investigation were used as: analysis, synthesis, deduction, induction.
As an example, Kozma Minin Nizhny Novgorod State Pedagogical University - Minin University was used. Based on the study of the "Regulations on the use of open courses in the educational activities of Minin University", it was noted, in addition to the functions of the coordination group on open education, that for the trainee at the end of the course, in the case of unsatisfactory result, the possibility of the recalculation is established. This paragraph is used not by every university.
In the article we make a conclusion that open courses are a new qualitative step in the development of world education, but online courses would be much more effective as narrow-minded, adult-oriented, and deeply motivated for learning. Taken as the basis of research, Minin University showed that the university is ready for the implementation of online courses. It is one of the few universities that actively use open courses in Russia.peer-reviewe
Role of the HAMP Domain Region of Sensory Rhodopsin Transducers in Signal Transduction
International audienceArchaea are able to sense light via the complexes of sensory rhodopsins I and II and their corresponding chemoreceptor-like transducers HtrI and HtrII. Though generation of the signal has been studied in detail, the mechanism of its propagation to the cytoplasm remains obscured. The cytoplasmic part of the transducer consists of adaptation and kinase activity modulating regions, connected to transmembrane helices via two HAMP (histidine kinases, adenylyl cyclases, methyl-accepting chemotaxis proteins, phosphatases) domains. The inter-HAMP region of Natronomonas pharaonis HtrII (NpHtrII) was found to be α-helical [Hayashi, K., et al. (2007) Biochemistry 46, 14380−14390]. We studied the inter-HAMP regions of NpHtrII and other phototactic signal transducers by means of molecular dynamics. Their structure is found to be a bistable asymmetric coiled coil, in which the protomers are longitudinally shifted by 1.3 Å. The free energy penalty for the symmetric structure is estimated to be 1.2−1.5 kcal/mol depending on the molarity of the solvent. Both flanking HAMP domains are mechanistically coupled to the inter-HAMP region and are asymmetric. The longitudinal shift in the inter-HAMP region is coupled with the in-plane displacement of the cytoplasmic part by 8.6 Å relative to the transmembrane part. The established properties suggest that (1) the signal may be transduced through the inter-HAMP domain switching and (2) the inter-HAMP region may allow cytoplasmic parts of the transducers to come sufficiently close to each other to form oligomers
STATE FUNCTION IN UNSTABLE CONVECTIVE MEDIUM
Convection in a thin layer of liquid (gas) with temperature independent viscosity between poorly heat conducting boundaries is studied within framework of the Proctor-Sivashinsky model. We have shown by numerical simulation of the Proctor-Sivashinsky model that the state with certain topology can be described by the state function, which is the sum of squared mode of temperature spatial spectrum on the surface. The transitions between these states are characterized by splashes in time-derivative of this function and different meta-stable structures, corresponding to different values of the state function have different visually distinguishable topologies
A search for light dark matter in XENON10 data
We report results of a search for light (<10 GeV) particle dark matter with
the XENON10 detector. The event trigger was sensitive to a single electron,
with the analysis threshold of 5 electrons corresponding to 1.4 keV nuclear
recoil energy. Considering spin-independent dark matter-nucleon scattering, we
exclude cross sections \sigma_n>3.5x10^{-42} cm^2, for a dark matter particle
mass m_{\chi}=8 GeV. We find that our data strongly constrain recent elastic
dark matter interpretations of excess low-energy events observed by CoGeNT and
CRESST-II, as well as the DAMA annual modulation signal.Comment: Manuscript identical to v2 (published version) but also contains
erratum. Note v3==v2 but without \linenumber
Аллергия к латексу: текущее состояние проблемы
Latex allergy: current state of the problem.Аллергия к латексу: текущее состояние проблемы
Atomic frequency comb memory in an isotopically pure 143Nd3+:Y7LiF4 crystal
© 2016 Astro Ltd. We implemented the atomic frequency comb protocol for optical quantum memory in an isotopically pure crystal of Y7LiF4 doped by 143Nd3+ ions. Echo signals were observed on the 4I9/2(1)-4F3/2(1) transition, which had inhomogeneous broadening much smaller than the hyperfine splitting of the ground and excited states. We performed hole-burning spectroscopy measurements on several transitions, obtaining information about the hyperfine state lifetimes. An intrinsic hole structure was found on some of the transitions, which allowed us to prepare a comb structure with two clearly defined periods and to observe echo pulses with different time delays
Review of nature of love in different psychological theories
The article considers the ideas about the love of authors of various theories of psychoanalysis.В статье рассмотрены представления о любви авторов различных теорий психоанализа
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