2,236 research outputs found
RIBFIND: a web server for identifying rigid bodies in protein structures and to aid flexible fitting into cryo EM maps
Motivation: To better analyze low-resolution cryo electron microscopy maps of macromolecular assemblies, component atomic structures frequently have to be flexibly fitted into them. Reaching an optimal fit and preventing the fitting process from getting trapped in local minima can be significantly improved by identifying appropriate rigid bodies in the fitted component.
Results: Here we present the RIBFIND server, a tool for identifying rigid bodies in protein structures. The server identifies rigid bodies in proteins by calculating spatial proximity between their secondary structural elements.
Availability: The RIBFIND web server and its standalone program are available at http://ribfind.ismb.lon.ac.uk
Peculiarities in produced particles emission in 208Pb + Ag(Br) interactions at 158 A GeV/c
The angular structures of particles produced in 208Pb induced collisions with
Ag(Br) nuclei in an emulsion detector at 158 A GeV/c have been investigated.
Nonstatistical ring-like substructures in azimuthal plane of the collision have
been found and their parameters have been determined. The indication on the
formation of the ring-like substructures from two symmetrical emission cones -
one in the forward and other in the backward direction in the center-of mass
system have been obtained. The ring-like substructures parameters have been
determined. The experimental results are in an agreement with I.M. Dremin idea,
that mechanism of the ring-like substructures formation in nuclear collisions
is similar to that of Cherenkov electromagnetic radiation.Comment: 10 pages, 7 figures, Report at the HADRON STRUCTURE'04 Conference,
Smolenice, Slovakia, 30.8.-3.9.200
Structure Analysis of Ice-Embedded Single Particles
The conventional negative-stain preparation method for electron microscopy, in which biological macromolecules are contrasted using heavy metal salts (such as uranyl-acetate), is a simple and fast technique which has helped visualize hundreds of different molecular structures. Computer analysis of such negatively stained images of individual (i.e., non-crystalline) macromolecules using statistical pattern-recognition techniques has revealed considerable new structural information. Negative staining, however, has some disadvantages: the specimens are often severely flattened (as much as 25%-75%), they often exhibit strong preferential attachment of the molecules to the supporting carbon foil, and the molecular images may be difficult to interpret due to the relatively complex nature of the interaction between molecules and stain. Embedding biological macromolecules in a layer of vitreous ice (actually: vitreous water ) represents an attractive alternative preparation method which mimics the natural environment of these molecules. The processing of ice-images often requires special computational approaches such as: multivariate statistical classification of aligned images or of invariant functions derived from the unaligned images; alignment of images belonging to a specific class of images, determination of the spatial orientations of the projection images relative to each other ( angular reconstitution ). In this paper, we discuss our own overall single-particle structure analysis approach and highlight some new methodological developments in this context
Determination of the Absorption Coefficient and Cloudiness Multiplicity Attenuation During the Gamma-Radiation Passage
The paper presents background value equivalent dose of gamma-radiation investigation in different weather: clear cloudy and overcast. The change of the dose rate of gamma radiation, depending on the weather and the ability cloudiness to shield gamma rays is shown. A new method for eliminating the consequences of accidents at nuclear power plants or plants using radioactive elements is proposed. A calculation method of cloudiness coefficient absorption and cloudiness gamma-radiation multiplicity attenuation is developed. The gamma- radiation multiplicity attenuation and the absorption coefficient of gamma radiation were calculated
Propagation of Magnetic Fields from Electrical Domestic Appliances
The article presents a research into propagation of magnetic fields from electrical domestic devices. A safe distance at which magnetic induction does not exceed the background level is determined for each type of devices. It is proved that there are two stages of increasing magnetic induction as the distance from the source increases. At the first stage magnetic induction rises and electromagnetic field is formed. At the second stage exponential decrease of magnetic field induction takes place. Mathematical regularities of propagation of magnetic field from electrical domestic devices are experimentally educed
Current Situation of the Ethical Principles of Social Advertising in Ukraine
Ґенеза формування та сучасний стан етичних принципів соціальної реклами в Україні розкривають основні проблеми функціонування на вітчизняних теренах комунікацій, що є носіями моральних норм гуманізму у суспільстві. Origin of creation and current situation of the ethical principles of social advertising in Ukraine brings about functioning issues of communication within the national landscape that is a carrier of moral norms of humanity in the society
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