Nucleon Resonances and Quark Structure

A pedagogical review of the past 50 years of study of resonances, leading to our understanding of the quark content of baryons and mesons. The level of this review is intended for undergraduates or first-year graduate students. Topics covered include: the quark structure of the proton as revealed through deep inelastic scattering; structure functions and what they reveal about proton structure; and prospects for further studies with new and upgraded facilities, particularly a proposed electron-ion collider.Comment: 21 pages, 15 figure

Improved approximation algorithm for k-level UFL with penalties, a simplistic view on randomizing the scaling parameter

The state of the art in approximation algorithms for facility location problems are complicated combinations of various techniques. In particular, the currently best 1.488-approximation algorithm for the uncapacitated facility location (UFL) problem by Shi Li is presented as a result of a non-trivial randomization of a certain scaling parameter in the LP-rounding algorithm by Chudak and Shmoys combined with a primal-dual algorithm of Jain et al. In this paper we first give a simple interpretation of this randomization process in terms of solving an aux- iliary (factor revealing) LP. Then, armed with this simple view point, Abstract. we exercise the randomization on a more complicated algorithm for the k-level version of the problem with penalties in which the planner has the option to pay a penalty instead of connecting chosen clients, which results in an improved approximation algorithm

Scanning Probe Techniques for Characterization of Vertically Aligned Carbon Nanotubes

This chapter presents the results of experimental studies of the electrical, mechanical and geometric parameters of vertically aligned carbon nanotubes (VA CNTs) using scanning probe microscopy (SPM). This chapter also presents the features and difficulties of characterization of VA CNTs in different scanning modes of the SPM. Advanced techniques for VA CNT characterization (the height, Young’s modulus, resistivity, adhesion and piezoelectric response) taking into account the features of the SPM modes are described. The proposed techniques allow to overcome the difficulties associated with the vertical orientation and high aspect ratio of nanotubes in determining the electrical and mechanical parameters of the VA CNTs by standard methods. The results can be used in the development of diagnostic methods as well as in nanoelectronics and nanosystem devices based on vertically aligned carbon nanotubes (memory elements, adhesive structures, nanoelectromechanical switches, emission structures, etc.)

A new approach to calculate the gluon polarization

We derive the Leading-Order master equation to extract the polarized gluon distribution G(x;Q^2) = x \deltag(x;Q^2) from polarized proton structure function, g1p(x;Q^2). By using a Laplace-transform technique, we solve the master equation and derive the polarized gluon distribution inside the proton. The test of accuracy which are based on our calculations with two different methods confirms that we achieve to the correct solution for the polarized gluon distribution. We show that accurate experimental knowledge of g1p(x;Q^2) in a region of Bjorken x and Q^2, is all that is needed to determine the polarized gluon distribution in that region. Therefore, to determine the gluon polarization \deltag /g,we only need to have accurate experimental data on un-polarized and polarized structure functions (F2p (x;Q^2) and g1p(x;Q^2)).Comment: 12 pages, 5 figure

SURGICAL CORRECTION OF INSUFFICIENCY OF CEREBRAL BLOOD FLOW AT THE ATHEROSCLEROSIS OF EXTRACEREBRAL ARTERIES

There is more than 1 million people who have had a stroke in Russia; the third part of these people are of working age, and only every fourth patient returned to job. This article discusses one of the most effective methods of stroke prevention - the procedure of carotid endarterectomy. We performed 468 reconstructive operations in 448 patients. 65 % (305) of surgeries were open carotid endarterectomies. In other cases, operations of prosthetics or blood flow switching between extracerebral arteries (ECA) (163) were carried out. Short-term results of reconstructive operations showed that 96 % of outcomes were positive. Perioperative mortality at operations made 1.06 %. The general complications made 4.5 %, minor complications were observed in 21 patients (4.4 %). The five years survival rate of patients operated on ECA made 86 %, the main cause of death in recent follow-up period was a cardiac pathology (58 %), brain disorders made 15 %. Among dominating risk factors are coronary heart disease, previous transient ischemic attacks and residual neurologic impairment

MODELING THE PROCESSES OF MOISTURE SEPARATION IN THE PGV‑1000M STEAM GENERATOR OF A VVER‑1000 REACTOR

The paper considers the process of modeling moisture separation in the PGV‑1000M steam generator, and the possibility of using this model in the development and research of NPP steam generators.В работе рассмотрен процесс моделирования сепарации влаги в парогенераторе ПГВ‑1000 М и возможность применения настоящей модели при разработке парогенераторов АЭС и исследовании происходящих в них процессов

Exploring the polarization of gluons in the nucleon

We give an overview of the current status of investigations of the polarization of gluons in the nucleon. We describe some of the physics of the spin-dependent gluon parton distribution and its phenomenology in high-energy polarized hadronic scattering. We also review the recent experimental results.Comment: 10 pages, 13 figures. Talk presented at the "Second Meeting of the APS Topical Group on Hadronic Physics", Nashville, Tennessee, October 22-24, 2006. Reference adde

Dijet production as a centrality trigger for p-p collisions at CERN LHC

We demonstrate that a trigger on hard dijet production at small rapidities allows to establish a quantitative distinction between central and peripheral collisions in pbar-p and p-p collisions at Tevatron and LHC energies. Such a trigger strongly reduces the effective impact parameters as compared to minimum bias events. This happens because the transverse spatial distribution of hard partons (x >~ 10^{-2}) in the proton is considerably narrower than that of soft partons, whose collisions dominate the total cross section. In the central collisions selected by the trigger, most of the partons with x >~ 10^{-2} interact with a gluon field whose strength rapidly increases with energy. At LHC (and to some extent already at Tevatron) energies the strength of this interaction approaches the unitarity ('black-body') limit. This leads to specific modifications of the final state, such as a higher probability of multijet events at small rapidities, a strong increase of the transverse momenta and depletion of the longitudinal momenta at large rapidities, and the appearance of long-range correlations in rapidity between the forward/backward fragmentation regions. The same pattern is expected for events with production of new heavy particles (Higgs, SUSY). Studies of these phenomena would be feasible with the CMS-TOTEM detector setup, and would have considerable impact on the exploration of the physics of strong gluon fields in QCD, as well as the search for new particles at LHC.Comment: 17 pages, Revtex 4, 14 EPS figures. Expanded discussion of some points, added 3 new figures and new references. Included comment on connection with cosmic ray physics near the GZK cutoff. To appear in Phys Rev

Potential of valsartan+sacubitril therapy in hypertensive heart disease

The course of hypertension is often complicated by left ventricular hypertrophy (or hypertensive heart disease, HHD). The main “corridor” of natural HHD is development of heart failure with preserved ejection fraction (HFpEF). With HFpEF, the bioavailability of natriuretic peptides (NP) is significantly reduced, as a result of which the activity of cGMP-PKG signaling pathway, which plays a key role in maintaining normal diastolic function, weakens. It is possible to increase the activity of this pathway using the neprilysin inhibitor sacubitril. In case of HFpEF, the greatest efficacy from valsartan+sacubitril therapy should be expected in patients with severe concentric LVH, who have the most pronounced natriuretic peptide deficiency. Valsartan+sacubitril therapy has a clear hypotensive effect, causes a reversal of left ventricular hypertrophy and fibrosis. Since no effective treatment has yet been found for HFpEF, the main way for HHD treatment should be to prevent the diastolic dysfunction progression, which justifies valsartan+sacubitril therapy starting from the early/ asymptomatic stages