Energy, Hamiltonian, Noether Charge, and Black Holes

It is shown that in general the energy ${\cal E}$ and the Hamiltonian ${\cal H}$ of matter fields on the black hole exterior play different roles. ${\cal H}$ is a generator of the time evolution along the Killing time while ${\cal E}$ enters the first law of black hole thermodynamics. For non-minimally coupled fields the difference ${\cal H}-{\cal E}$ is not zero and is a Noether charge $Q$ analogous to that introduced by Wald to define the black hole entropy. If fields vanish at the spatial boundary, $Q$ is reduced to an integral over the horizon. The analysis is carried out and an explicit expression for $Q$ is found for general diffeomorphism invariant theories. As an extension of the results by Wald et al, the first law of black hole thermodynamics is derived for arbitrary weak matter fields.Comment: 20 pages, latex, no figure

Application of the Large-N_c limit to a Chiral Lagrangian with Resonances

It is shown that the implementation of the Large--$N_c$ approximation helps to get insight into the structure of, in principle, any QCD-like theory. As an example, we will compute the NLO corrections to $L_{10}$ in the chiral limit with a Lagrangian with Resonances.Comment: 9 pages, 1 figure. Talk given at the International School of Subnuclear Physics (Erice 2002). To be published in the Proceeding

Impact of Electrical Current on Single GaAs Nanowire Structure

The impact of electrical current on the structure of single free-standing Be-doped GaAs nanowires grown on a Si 111 substrate is investigated. Single nanowires have been structurally analyzed by X-ray nanodiffraction using synchrotron radiation before and after the application of an electrical current. The conductivity measurements on single nanowires in their as-grown geometry have been realized via W-probes installed inside a dual-beam focused ion beam/scanning electron microscopy chamber. Comparing reciprocal space maps of the 111 Bragg reflection, extracted perpendicular to the nanowire growth axis before and after the conductivity measurement, the structural impact of the electrical current is evidenced, including deformation of the hexagonal nanowire cross section, tilting, and bending with respect to the substrate normal. For electrical current densities below 30 A mm−2, the induced changes in the reciprocal space maps are negligible. However, for a current density of 347 A mm−2, the diffraction pattern is completely distorted. The mean cross section of the illuminated nanowire volume is reconstructed from the reciprocal space maps before and after the application of electrical current. Interestingly, the elongation of two pairs of opposing side facets accompanied by shrinkage of the third pair of facets is found. The variations in the nanowire diameter, as well as their tilt and bending, are confirmed by scanning electron microscopy. To explain these findings, material melting due to Joule heating during voltage/current application accompanied by anisotropic deformations induced by the W-probe is suggested

QCD Instantons and the Soft Pomeron

We study the role of semi-classical QCD vacuum solutions in high energy scattering by considering the instanton contribution to hadronic cross sections. We propose a new type of instanton-induced interactions (``instanton ladder'') that leads to the rising with energy hadronic cross section of Regge type (the Pomeron). We argue that this interaction may be responsible for the structure of the soft Pomeron. The intercept is calculated. It has a non-analytic dependence on the strong coupling constant, allowing a non-singular continuation into the non-perturbative region. We derive the Pomeron trajectory, which appears to be approximately linear in some range of (negative) momentum transfer t, but exhibits a curvature at small t. Possible role of instantons in multiparticle production is also discussed.Comment: 20 pages, 8 figures, ReVTe

Instantons in the Saturation Environment

We show that instanton calculations in QCD become theoretically well defined in the gluon saturation environment which suppresses large size instantons. The effective cutoff scale is determined by the inverse of the saturation scale. We concentrate on two most important cases: the small-x tail of a gluon distribution of a high energy hadron or a large nucleus and the central rapidity region in a high energy hadronic or heavy ion collision. In the saturation regime the gluon density in a single large ultrarelativistic nucleus is high and gluonic fields are given by the classical solutions of the equations of motion. We show that these strong classical fields do not affect the density of instantons in the nuclear wave function compared to the instanton density in the vacuum. A classical solution with non-trivial topological charge is found for the gluon field of a single nucleus at the lowest order in the instanton perturbation theory. In the case of ultrarelativistic heavy ion collisions a strong classical gluonic field is produced in the central rapidity region. We demonstrate that this field introduces a suppression factor of exp{-c \rho^4 Q_s^4 / [8 \alpha^2 N_c (Q_s \tau)^2]} in the instanton size distribution, where Q_s is the saturation scale of both (identical) nuclei, \tau is the proper time and c = 1 is the gluon liberation coefficient. This factor suggests that gluonic saturation effects at the early stages of nuclear collisions regulate the instanton size distribution in the infrared region and make the instanton density finite by suppressing large size instantons.Comment: 20 pages, 8 figures, REVTeX, some discussion added including a possible scenario for unitarization of the soft pomero

Иммунологические эффекты адалимумаба при ревматоидном артрите: результаты Российского национального исследования

A reduction in immunological parameters during therapy for rheumatoid arthritis (RA) can yield new data on the mechanisms of anti-inflammatory action and be of great practical importance since this allows judgment of the depth of impact on the immunological process and therefore may be regarded as one of the components of improvement and remission. Objective: to study the effect of the tumor necrosis factor-a (TNF-а) inhibitor adalimumab (ADA) on a number of key immunological parameters in RA. Subjects and methods. The study included 100 patients (11 men and 89 women) diagnosed with RA from 5 research centers. The patients were observed to have high RA activity: at baseline, DAS28 6.22+0.84 scores; C-reactive protein (CRP) 37.1+34.7 mg/l. The mean number of disease-modifying antirheumatic drugs (DMARDs) used by a patient in the history was 2.1. During 24-week treatment, the patients took ADA in a subcutaneous dose of 40 mg every 2 weeks both alone and in combination with DMARDs. The time course of changes in the serum levels of CRP, IGM rheumatoid factor (RF) and in the concentration of anti-cyclic citrullinated peptide 2 (anti-CCP2) antibodies was determined by enzyme immunoassay (EIA) using the Axis-Shield Diagnostics commercial kits (United Kingdom). The levels of TNF-a, interleukin (IL) 6, 12, matrix metalloproteinase 3 (MMP3) were measured in pg/ml by EIA using the Bender MedSystems commercial kits (USA) according to the manufacturer's directions. Results. During ADA therapy, there was a rapid reduction in the level of CRP from 34.3 to 11.317.2 mg/l following 2 weeks (p<0.001), which thereafter remained low (11.9 mg/l), with some fluctuations, until week 24 of the study. There was a significant reduction in blood RF levels from 169.24 to 111.97 at 24 weeks (p<0.001). After 12 weeks of ADA treatment, there was virtually a two-fold decrease in IL-6 content from 8.87 to 4.87 pg/ml and later on to 4.03 pg/ml at week 24 (p>0,05). The mean levels of anti-CCP2 antibodies, IL-12, VEGF, and MMP3 remained unchanged. Conclusion. The time course of changes in immunological parameters during ADA treatment demonstrates the rapid and deep effect of TNF-a inhibitors on the different components of the pathogenesis of RA.Снижение иммунологических показателей на фоне терапии ревматоидного артрита (РА) позволяет получить новые данные о механизмах противовоспалительного действия и имеет важное практическое значение, поскольку позволяет судить о глубине воздействия на иммунопатологический процесс и поэтому может оцениваться как один из компонентов улучшения и ремиссии. Цель исследования — изучение влияния ингибитора фактора некроза опухоли α (ФНОα) адалимумаба (АДА) на ряд ключевых иммунологических показателей при РА. Материал и методы. В исследование включено 100 пациентов из 5 исследовательских центров с диагнозом РА (11 мужчин и 89 женщин). У пациентов наблюдалась высокая активность РА: исходно индекс DAS28 — 6,22±0,84 балла, уровень С-реактивного белка (СРБ) — 37,1+34,7мг/л. Среднее число базисных противовоспалительных препаратов (БПВП) в анамнезе, применявшихся одним пациентом, составило 2,1. За время лечения (24 нед) пациенты получали АДА в дозе 40 мг каждые 2 нед подкожно как в комбинации с БПВП, так и в монотерапии. Определяли в динамике сывороточные уровни СРБ, IgM ревматоидного фактора (РФ), концентрацию антител к циклическому цитруллинированному пептиду 2 (АЦЦП2) изучали иммуноферментным методом (ИФМ) с помощью коммерческих наборов Axis-Shield Diagnostics (Великобритания). Содержание ФНОа, интерлейкина (ИЛ) 6, 12, матриксной металлопротеиназы 3 (ММР3) определяли ИФМ (в пг/мл) с использованием коммерческих наборов Bender MedSystems (США) согласно инструкциям фирмы-изготовителя. Результаты исследования. На фоне терапии АДА наблюдалось быстрое снижение уровня СРБ с 34,3 до 11,3+17,2 мг/л через 2 нед (p<0,001), который в дальнейшем с некоторыми колебаниями оставался низким (11,9 мг/л) до 24-й недели исследования. Наблюдалось достоверное снижение уровня РФ в крови с 169,24 до 111,97на 24-й неделе (p<0,001). Через 12 нед после начала лечения АДА отмечалось практически 2-кратное снижение содержания ИЛ6 с 8,87 до 4,87 пг/мл и в дальнейшем, к 24-й неделе, — до 4,03 пг/мл (p>0,05). Средние уровни АЦЦП, ИЛ12, фактора роста эндотелия сосудов (VEGF), ММП3 не изменились. Выводы. Динамика иммунологических параметров при лечении АДА демонстрирует быстрое и глубокое действие ингибиторов ФНОа на различные звенья патогенеза РА

Pressure Treatment of Polytene Chromosomes and Computer Vision Techniques for High Resolution Cytogenetic Studies

48 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008.The exceptional cytology provided by the interphase chromatin organization in polytene chromosomes has made Drosophila the premier model organism for analysis of chromosome structure and behavior. A major impediment to full exploitation of polytene chromosome cytology has been the difficulty in producing high quality chromosome spreads. This is particularly true for applications requiring prior formaldehyde fixation. Individual chromosome bands are seldom resolved in typical preparations, with many appearing fused. Here we describe a new procedure for preparing polytene chromosome spreads which exploits high pressure, together with other modifications, to produce high quality chromosome spreads whose light microscopy images reproducibly show comparable detail to electron microscopy images of conventionally prepared spreads. We illustrate results obtained with this procedure from typical cytological applications, including immunofluorescence and fluorescence in situ hybridization (FISH). Description of optimized downstream staining procedures for light and electron microscopy is included. Development of computer vision applications for automated recognition and structural analysis of polytene chromosomes are discussed. Prospective and collaborative studies are described.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Theta and alpha band modulations reflect error-related adjustments in the auditory condensation task

Error commission leads to adaptive adjustments in a number of brain networks that subserve goal-directed behavior, resulting in either enhanced stimulus processing or increased motor threshold depending on the nature of errors committed. Here, we studied these adjustments by analyzing post-error modulations of alpha and theta band activity in the auditory version of the two-choice condensation task, which is highly demanding for sustained attention while involves no inhibition of prepotent responses. Errors were followed by increased frontal midline theta (FMT) activity, as well as by enhanced alpha band suppression in the parietal and the left central regions; parietal alpha suppression correlated with the task performance, left central alpha suppression correlated with the post-error slowing, and FMT increase correlated with both behavioral measures. On post-error correct trials, left-central alpha band suppression started earlier before the response, and the response was followed by weaker FMT activity, as well as by enhanced alpha band suppression distributed over the entire scalp. These findings indicate that several separate neuronal networks are involved in post-error adjustments, including the midfrontal performance monitoring network, the parietal attentional network, and the sensorimotor network. Supposedly, activity within these networks is rapidly modulated after errors, resulting in optimization of their functional state on the subsequent trials, with corresponding changes in behavioral measures