NEW RECORDS FOR THE FAUNA AND ZOOGEOGRAPHY OF CUCKOO WASPS (HYMENOPTERA: CHRYSIDIDAE) IN THE LOWER VOLGA REGION

The fauna and zoogeography of chrysidids in the steppe and forest biocenoses of the Lower Volga region in the Saratov region were studied, which include 92 species and 2 subspecies from 17 genera: Cleptes – 2 species; Colpopyga – 1; Elampus – 8; Haba – 1; Hedychridium – 6; Hedychrum – 5; Holopyga – 11; Omalus – 2; Philoctetes – 3; Pseudomalus – 5; Chrysidea – 1; Chrysis – 41; Chrysura – 3; Spinolia – 1; Stilbum – 2; Trichrysis – 1 and Parnopes – 1, among which 69 species are presented for the Saratov region for the first time. Two species, Chrysis corusca Valkeila, 1971 and Chrysis vanlithi Linsenmaier, 1959, and one subspecies Chrysis frivaldszkyi sparsepunctata du Buysson, 1895, are new records for the Russian fauna. The obtained data broaden the understanding of the fauna and diversity of Chrysididae in the Saratov region and the Lower Volga region and supplement the fauna list of the Chrysididae of Russian fauna

In situ X-ray diffraction investigation of nitride coatings at high-temperature oxidation

Structural and phase researches of the multicomponent nanocrystalline coatings synthesized by plasma-assisted vacuum arc method at high-temperature influence by method of X-ray diffraction with the use of synchrotron radiation in situ have been carried out. The main features of these coatings are the superhardness (39 - 45 GPa) and nanocrystalline structure (5 - 20 nm). The analysis of results of structural and phase researches, physical and mechanical characteristics after oxidation of multicomponent nitride coatings at high-temperature heating in open air is presented

QED radiative corrections to impact factors

We consider the radiative corrections to the impact factors of electron and photon. According to a generalized eikonal representation the e\bar e scattering amplitude at high energies and fixed momentum transfers is proportional to the electron form factor. But we show that this representation is violated due to the presence of non-planar diagrams. One loop correction to the photon impact factor for small virtualities of the exchanged photon is obtained using the known results for the cross section of the e\bar e production at photon-nuclei interactions.Comment: 8 pp, plain LaTe

CEREBRAL REVASCULIZATION IN PATIENTS OF 70 YEARS AND OLDER

The aim of the work was to evaluate the perioperative management of aged patients after elective surgical cerebral revascularization. We analyzed the outcomes of 813 patients of 70 years and older who had surgery for stenosis of the internal carotid artery [ІСА]. There were two groups: 392 patients who had carotid endarterectomy [CEA] and 421 patients who had the stenting. Age of the patients, severity of disease and comorbidity were similar in both groups In aged patients, the incidence of acute disorders of cerebral circulation (stroke] after CEA was significantly lower than the one after stenting (p = 0,04]. Frequency of perioperative myocardial infarction [MI] was 3 times higher in cases with CEA (p = 0,03]. in patients of 70 years and older, CEA shown lower incidence of stroke, however, there is increase of perioperative MI while using this method. Endovascular treatment could be chosen in patients with severe cardiac disease according to atherosclerotic plaques with no risk of embolism. In addition, the individual approach and assessment of social aspect are necessary

FEATURES OF POSTOPERATIVE PERIOD IN PATIENTS AFTER BRAIN REVASCULARIZATION

The aim of the research was to compare incidence of small complications after carotid endarterectomy (CEA) versus carotid artery stenting, as well as to evaluate its application in specific clinical situations. The outcomes of1826 patients who underwent surgery for stenosis of the internal carotid artery (ICA) were analyzed. There were two groups: 1018 patients who underwent CEA and 808 patients who carried the stenting. Age of patients was greater and coronary heart disease, diabetes, chronic obstructive pulmonary disease occurs more often in group with endovascular treatment, and they had rife stroke anamnesis. The mortality rate, uncontrolled hypertension and transient ischemic attacks were similar in early postoperative period. Stroke frequency was higher in patients with carotid artery stenting (35 (4,3 %) versus 27 patients (2,6 %) with CEA (p = 0,02)), and myocardial infarction took place more often after CEA (38 (3,7 %) versus 13 (1,6 %) patients with endovascular treatment (p = 0,008)). There was no statistically significant difference in security between CEA and stenting. However, treatment of carotid stenosis should be chosen according to individual characteristics, including individual anatomy

Polarized triplet production by circularly polarized photons

A process of the pair production by a circularly polarized photon in the field of unpolarized atomic electron has been considered in the Weizaecker-Williams approximation. The degree of longitudinal polarization of positron and electron has been calculated. An exclusive cross-section as well as a spectral distribution are obtained. We estimate the accuracy of our calculations at the level of a few percent. We show the identity of the positron polarization for considered process and for process of pair production in the screened Coulomb field of nucleus.Comment: 9 pages, 3 picture

Possible Method for Measuring the Proton Form Factors in Processes with and without Proton Spin Flip

The ratio of the squares of the electric and magnetic proton form factors is shown to be proportional to the ratio of the cross sections for the elastic scattering of an unpolarized electron on a partially polarized proton with and without proton spin flip. The initial proton at rest should be polarized along the direction of the motion of the final proton. Similar results are valid for both radiative $ep$ scattering and the photoproduction of pairs on a proton in the Bethe--Heitler kinematics. When the initial proton is fully polarized in the direction of the motion of the final proton, the cross section for the $ep \to ep$ process, as well as for the $ep \to ep \gamma$ and $\gamma p \to e \bar e p$ processes, without (with) proton spin flip is expressed only in terms of the square of the electric (magnetic) proton form factor. Such an experiment on the measurement of the cross sections without and with proton spin flip would make it possible to acquire new independent data on the behavior of $G_E^2(Q^2)$ and $G_M^2(Q^2)$, which are necessary for resolving the contradictions appearing after the experiment of the JLab collaboration on the measurement of the proton form factors with the method of polarization transfer from the initial electron to the final proton.Comment: 7 pages, revtex

SCIENTIFIC AND METHODICAL APPROACHES TO INCREASE PROSPECTING EFFICIENCY OF THE RUSSIAN ARCTIC SHELF STATE GEOLOGICAL MAPPING

A rationale for the set of theoretical and methodological techniques of mapping and deep modeling in the Russian Arctic shelf and adjacent sedimentary basins in continental Russia is based on the materials for the Barents and Kara Seas region. This article provides the factual basis of the research and shows how to apply zonal-block model of the crust and generalized models of geodynamic settings in terms of the different geophysical data inconsistency. The necessity and approach for global and regional paleo-reconstructions are also discussed. It is shown that localization of the principal structural and compositional units of the lithosphere being a consequence of geodynamic processes at the boundaries of lithospheric plates, form at the basis of sedimentary cover and crystalline basement layered maps as well as cross-sections of the continental crust. The identified parameters of the deep structure and milestones of the regional tectonic history open new opportunities to explore the regularities of ore deposits distribution. The shown example of the forecast and metallogeny problems solution within Western Siberia and Khatanga-Vilyui petroleum provinces is made using the parameters of known industrial oil and gas fields for training the pattern recognition system

An integral equation based computer code for high-gain free-electron lasers

A computer code for gain optimization of high-gain free-electron lasers (FELs) is described. The electron motion is along precalculated period-averaged trajectories, and the finite-emittance electron beam is represented by a set of thin partial beams. The radiation field amplitudes are calculated at these thin beams only. The system of linear integral equations for these field amplitudes and the Fourier harmonics of the current of each thin beam is solved numerically. The code is aimed for design optimization of high-gain short-wavelength FELs with nonideal magnetic systems (breaks between undulators with quadrupoles and magnetic bunchers; field and steering errors). Both self-amplified spontaneous emission (SASE) and external input signal options can be treated. A typical run for a UV FEL, several gain lengths long, takes only one minute on a Pentium II personal computer (333 MHz) which makes it possible to run the code in optimization loops. Results for the Advanced Photon Source FEL project are presented