1,875 research outputs found
Simplified method of linking raster image points of Earth remote sensing satellites to geographical coordinates
In article the simplified method of definition of a binding pixels raster picture to geographical coordinates in multichannel satellite imageries of the remote sensing (RS) of Earth is described. It is assumed that the picture is a rectangular raster with dimensions of the coating area on the surface of the Earth within the limits of the first hundred kilometers, obtained when the direction of shooting is deviated from nadir within the limits of the first degrees. At the same time the corner points of the screen have reference to geographical coordinates of sufficient accuracy. It is required to bind each raster pixel to a point on the Earth's surface, that is, to constrain the column and row of the raster pixel to the geographical latitude and longitude of the corresponding point. This paper proposes a simplified universal method, without some of the disadvantages inherent in standard methods of solving the problem. It is based on considering the geometric features raster and the area of the Earth surface covers it
The Bose-Einstein correlation function from a Quantum Field Theory point of view
We show that a recently proposed derivation of Bose-Einstein correlations
(BEC) by means of a specific version of thermal Quantum Field Theory (QFT),
supplemented by operator-field evolution of the Langevin type, allows for a
deeper understanding of the possible coherent behaviour of the emitting source
and a clear identification of the origin of the observed shape of the BEC
function . Previous conjectures in this matter obtained by other
approaches are confirmed and have received complementary explanation.Comment: Some misprints corrected. To be publishe in Phys. Rev.
Intrinsically Disordered C-Terminal Tails of \u3cem\u3eE. coli\u3c/em\u3e Single-Stranded DNA Binding Protein Regulate Cooperative Binding to Single-Stranded DNA
The homotetrameric Escherichia coli single-stranded DNA binding protein (SSB) plays a central role in DNA replication, repair and recombination. E. coli SSB can bind to long single-stranded DNA (ssDNA) in multiple binding modes using all four subunits [(SSB)65 mode] or only two subunits [(SSB)35 binding mode], with the binding mode preference regulated by salt concentration and SSB binding density. These binding modes display very different ssDNA binding properties with the (SSB)35 mode displaying highly cooperative binding to ssDNA. SSB tetramers also bind an array of partner proteins, recruiting them to their sites of action. This is achieved through interactions with the last 9 amino acids (acidic tip) of the intrinsically disordered linkers (IDLs) within the four C-terminal tails connected to the ssDNA binding domains. Here, we show that the amino acid composition and length of the IDL affects the ssDNA binding mode preferences of SSB protein. Surprisingly, the number of IDLs and the lengths of individual IDLs together with the acidic tip contribute to highly cooperative binding in the (SSB)35 binding mode. Hydrodynamic studies and atomistic simulations suggest that the E. coli SSB IDLs show a preference for forming an ensemble of globular conformations, whereas the IDL from Plasmodium falciparum SSB forms an ensemble of more extended random coils. The more globular conformations correlate with cooperative binding
Propagation and interaction of ultrashort electromagnetic pulses in nonlinear media with a quadratic-cubic nonlinearity
Propagation of extremely short unipolar pulses of electromagnetic field
("videopulses") is considered in the framework of a model in which the material
medium is represented by anharmonic oscillators (approximating bound electrons)
with quadratic and cubic nonlinearities. Two families of exact analytical
solutions (with positive or negative polarity) are found for the moving
solitary pulses. Direct simulations demonstrate that the pulses are very robust
against perturbations. Two unipolar pulses collide nearly elastically, while
collisions between pulses with opposite polarities and a small relative
velocity are inelastic, leading to emission of radiation and generation of a
small-amplitude additional pulse.Comment: 12 pages, 10 figure
Development Liquid Rocket Engine of Small Thrust With Combustion Chamber from Carbon - Ceramic Composite Material
Synthesis of silymarin−selenium nanoparticle conjugate and examination of its biological activity in vitro
Silymarin (Sil) was conjugated to selenium nanoparticles (SeNPs) to increase Sil bioavailability. The conjugates were monodisperse; the average diameter of the native SeNPs was ~ 20-50 ± 1.5 nm, whereas that of the conjugates was 30-50 ± 0.5 nm. The use of SeNPs to increase the bioavailability of Sil was examined with the MH-22a, EPNT-5, HeLa, Hep-2, and SPEV-2 cell lines. The EPNT-5 (glioblastoma) cells were the most sensitive to the conjugates compared to the conjugate-free control. The conjugates increased the activity of cellular dehydrogenases and promoted the penetration of Sil into the intracellular space. Possibly, SeNPs play the main part in Sil penetration of cells and Sil penetration is not associated with phagocytosis. Thus, SeNPs are promising for use as a Sil carrier and as protective antigens
- …