Multivariate data analysis based on the ωkn-criteria and multilayer perceptron

AbstractA comparative study of multidimensional classifiers based on the goodness-of-fit criteria ωkn and multilayer perceptrons (MLP) has been carried out. It is shown that MLP exhibits the “instantaneous” learning effect and improves the quality of recognition in the case of input data represented in the form of variational series. The reasons are analyzed that underlie these effects. Recommendations for joint usage of the ωkn criteria and of MLPs are given

Conformations of ribonucleoside uridine in the low temperature Ar matrices

The conformational equilibrium of the ribonucleoside uridine molecules in the low temperature Ar matrices was investigated by the FTIR matrix isolation spectroscopy and quantum-chemical calculations at the DFT and MP2 levels of theory. It was established that conformers with the carbonyl group C2O which takes part in the intramolecular hydrogen bonds dominate in the low temperature matrices. Populations of syn- and anticonformers with intramolecular hydrogen bonds O5’H–O2 and O2’–O2, respectively, are equal practically. Unlike 2’-deoxyuridine, the syn-conformers of Ur with C3’-endo structure of the ribose ring (South) have been found in Ar matrices. At the same time the conformations of C2’-endo (North) ribose ring prevail both in antiand syn-conformers

FTIR spectra and conformations of 2`-deoxyuridine in Kr matrices

The Fourier transform infrared spectra in the range 4000–200 cm⁻¹ of pyrimidine nucleoside 2'-deoxyuridine (dU) have been obtained in the low temperature inert Kr matrices. For the first time, instead of a usual flat mirror, a low temperature one-coordinate retroreflector was used as the matrix substrate. Owing to this, the matrix setup is insensitive to dip angle vibrations of the cryostat and is favourable to work with thinner matrix layers. Of two syn-conformers with dU_s1 and dU_s2 (stabilized by the intramolecular hydrogen bond O5'H…O2), only dT_s2 conformer with C2'-endo structure of the ribose ring was uniquely quenched. The height of the interconversion barrier of the minor syn-conformer dU_s1 was estimated to be below 0.7 kcal/mole. It was shown that the energy relaxation of impurities in Kr is slower than in Ar matrices

Molecular structures of thymidine isomers isolated in low-temperature inert matrices

The Fourier transform infrared spectra of 2`-deoxyribonucleoside — thymidine (dT) in low-temperature Ar matrices are obtained in the range 4000–1300 cm–¹. It is determined that anti-conformers of thymidine are dominant. The ribose rings of the main anti-conformers dT_a0, dT_a1 are in the C2`-endo conformation, but the ribose rings of minor anti-conformers dT_a2, dT_a3 have the C3`-endo conformation, stabilized by intramolecular hydrogen bonds O3`H…O5` and O5`H…O3`, respectively. The main syn-conformer dT_s2 is stabilized by the intramolecular hydrogen bond O5`H…O2 and has C2`-endo conformation of the ribose ring

Solitons in isotropic antiferromagnets: beyond a sigma model

Isotropic antiferromagnets shows a reach variety of magnetic solitons with nontrivial static and dynamic properties. One-dimensional soliton elementary excitations have a periodic dispersion law. For two-dimensional case, planar antiferromagnetic vortices having nonsingular macroscopic core with the saturated magnetic moment are present. The dynamic properties of these planar antiferromagnetic vorteces are characterized by presence of a gyroforce

The semileptonic decays of the B_c meson

We study the semileptonic transitions B_c to \eta_c, J/\psi, D, D^*, B, B^*, B_s, B_s^* in the framework of a relativistic constituent quark model. We use experimental data on leptonic J/\psi decay, lattice and QCD sum rule results on leptonic B_c decay, and on radiative \eta_c transitions to adjust the quark model parameters. We compute all form factors of the above semileptonic B_c-transitions and give predictions for various semileptonic B_c decay modes including their \tau-modes when they are kinematically accessible. The implications of heavy quark symmetry for the semileptonic decays are discussed and are shown to be manifest in our explicit relativistic quark model calculation. A comparison of our results with the results of other calculations is performed.Comment: 31 pages Latex (uses epsf, revtex). Section II expanded, typos corrected. This version will appear in Phys. Rev.

Complete Low-Energy Effective action in N=4 SYM: a Direct N=2 Supergraph Calculation

Using the covariant N=2 harmonic supergraph techniques we calculate the one-loop low-energy effective action of N=4 super-Yang-Mills theory in Coulomb branch with gauge group SU(2) spontaneously broken down to U(1). The full dependence of the low-energy effective action on both the hypermultiplet and gauge fields is determined. The direct quantum calculation confirms the correctness of the exact N=4 SYM low-energy effective action derived in hep-th/0111062 on the purely algebraic ground by invoking a hidden N=2 supersymmetry which completes the manifest N=2 one to N=4. Our results provide an exhaustive solution to the problem of finding out the exact completely N=4 supersymmetric low-energy effective action for the theory under consideration.Comment: LaTeX, 21 pages; minor correction

Experimental research on plasma destruction of bone tissue

The main condition in achieving a favorable outcome is surgical treatment of patients with tumor-like diseases and benign bone tumors erosion of neoplasm within the healthy tissues. To reduce the number of recurrences the various chemical and physical methods on resection areas have been performed. The authors have proposed a new method of low temperature plasma treatment of bone tissue with the temperature of 20000°C. Exposing the plasma flow on bone tissue leads to loss of all cellular elements including neoplastic elements with preservation of the mineral bone structure. The direct correlation between the capacity of the plasma flow and intensity of bone destruction has been defined. This allows a differentiated use of plasma destruction in skeletal bones according to anatomy, size and type of bone tissue (spongy or cortical) as well as patient's individual condition of the tissu

Morphofunctional state of spleening under light desynchronosis in the experiment

&nbsp;Aim: to study the effects of light desynchronosis on the morphofunctional state of the spleen of white male rats. Material and Methods. The study of light desynchronosis was carried out on 48 male rats using the Light Light model with an illumination power of 300 Ix in the daylight and 500 Ix in the dark. The laboratory animals in the experiment were divided into four groups: the control and three experimental ones, in which they were exposed to light for 1 day, 10 days, 21 days respectively. In the course of morphometry of histological sections of the spleen, the following parameters were assessed: the area of white pulp lymphoid follicles, B- and T-clependent zones of white pulp, the number of germinative centers and immunoblasts in B- and T-zones. Results. On day 1 of the experiment, an increase in the area of the lymphoid follicle, periarterial and B-dependent zones, an increase in the number of immunoblasts and reproduction centers was registered. By the 10th day there was a partial restoration of these indicators relative to the control values. On the 21st day of the experiment, a decrease in the growth dynamics of all the morphometric parameters of the spleen was observed. Conclusion. Light desynchronosis induces by the Light Light model leads to the development of the pathology of the immune system with an extensive shift of all measurable indicators. Key words: morphofunctional state of the spleen, morphometric criteria, light desynchronosis, immunity.</p

Fermi resonance in Ne, Ar and Kr-matrix infrared spectra of 5-bromouracil

Low-temperature matrix isolation Fourier-transform infrared spectroscopy and quantum-chemical calcula-tions with DFT/B3LYP and MP2 methods were used for investigation of isolated 5-bromouracil (BrU) mole-cules. Only one tautomeric form of BrU was dominated in the low-temperature Ne, Ar, and Kr matrices. It was revealed that population of minor hydroxy-tautomers did not exceed 0.2%. Appearance of additional absorption bands in the region of stretching vibrations CO (about 1710 cm⁻¹) as well as of deformation ones (1297, 1093, 901 cm⁻¹) was explained by Fermi resonance. In Ne matrices the peak intensities of absorption bands assigned to the out-of-plane vibrations of the ring and exocyclic atoms were decreased sharply. For the first time, least square method with the using of polynomial was proposed for the corrective scaling of calculated frequencies of vibrations. It is shown that the correction of calculated frequencies with the polynomial of degree two permits to decrease the root-mean-square discrepancy between the calculated and experimental ones to 4–5 cm⁻¹ in the re-gion of 1500–500 cm⁻¹. The same polynomial may be applied for the correction of spectra of molecules with a similar structure