Dynamic aperture limitation in e+e−e^+e^- colliders due to synchrotron radiation in quadrupoles

In a lepton storage ring of very high energy (e.g. in the $e^+e^-$ Higgs factory) synchrotron radiation from quadrupoles constrains transverse dynamic aperture even in the absence of any magnetic nonlinearities. This was observed in tracking for LEP and the Future Circular $e^+e^-$ Collider (FCC-ee). Here we describe a new mechanism of instability created by modulation of the particle energy at the double betatron frequency by synchrotron radiation in the quadrupoles. Energy modulation varies transverse focusing strength at the same frequency and creates a parametric resonance of the betatron oscillations with unusual properties. It occurs at arbitrary betatron frequency (the resonant detuning is always zero) and the magnitude of the parameter modulation of the betatron oscillation (strength of the resonance driving term) depends on the oscillation amplitude. Equilibrium between the radiation damping and the resonant excitation gives the boundary of the stable motion. Starting from 6d equations of motion we derive and solve the relevant differential equation describing the resonance, and show good agreement between analytical results and numerical simulation

Vibronic interaction in crystals with the Jahn-Teller centers in the elementary energy bands concept

The order-disorder type phase transition caused by the vibronic interaction (collective Jahn-Teller effect) in a monoclinic CuInP$_2$S$_6$ crystal is analyzed. For this purpose, a trigonal protostructure model of CuInP$_2$S$_6$ is created, through a slight change in the crystal lattice parameters of the CuInP$_2$S$_6$ paraelectric phase. In parallel to the group-theoretical analysis, the DFT-based {\it ab initio} band structure calculations of the CuInP$_2$S$_6$ protostructure, para-, and ferriphases are performed. Using the elementary energy bands concept, a part of the band structure from the vicinity of the forbidden energy gap, which is created by the $d$-electron states of copper, has been related with a certain Wyckoff position where the Jahn-Teller's centers are localized. A construction procedure of the vibronic potential energy matrix is generalized for the case of crystal using the elementary energy bands concept and the group theoretical method of invariants. The procedure is illustrated by the creation of the adiabatic potentials of the $\Gamma_5$-$\Gamma_5$ vibronic coupling for the protostructure and paraphase of the CuInP$_2$S$_6$ crystal. A structure of the obtained adiabatic potentials is analyzed, followed by conclusions on their transformation under a phase transition and the discussion on the possibility for the spontaneous polarization to arise in this crystal.Comment: 17 pages, 7 figure

Dynamic Aperture Studies in e+e−e^{+}e^{−} Factories with Crab Waist

Crab Waist collision scheme being applied to the electron-positron collider may limit a dynamic aperture essentially. In the paper we discuss some aspects of such limitation including low emittance lattice, strong crab sextupoles, crosstalk between beam-beam nonlinear force and lattice nonlinearities, and small multipole errors in the final focus quadrupoles

“Unsubscription” as a Violation of the Legislation of the Russian Federation on the Procedure for Considering Citizens’ Appeals: Problem Statement

The word “unsubscription” has long been firmly used by Russian citizens, but this social phenomenon has not yet been studied in practice in legal science. In this article, the Author tried to fill this gap and analyze the nature of the replies of modern Russian officials, classify them, and identify the causes and conditions that determine them.When preparing the article, we used methods of formal logic-comparison, description, classification, analysis, synthesis, etc., which allowed us to characterize the existing system of consideration of citizens from the position of its normative content. Among the private scientific methods, the formal-legal method used in the analysis of legal norms on consideration of appeals was used; logical-legal method, by which the content of legal norms in relation to the problem under consideration was studied; specifically, it is a sociological approach that was used in the analysis of statistical data related to the research problem.The Author offers a classification of unsubscriptions depending on their content, the motive for writing, the circle of subjects, and the degree of multiplicity. Separately, the article analyzes formal responses with little content, sent from higher and Supervisory authorities, if the applicant applies to them after receiving a response from another authority and disagrees with it. On the example of specific unsubscriptions, we analyze options for evading inspections by law enforcement officials related to violations of the rights of citizens-applicants.The author cites corporate rules of conduct, a desire to get rid of work, “defending the honor of the uniform”, excessive secrecy of activities, as well as the impunity of the official who prepared the response as reasons for the formal attitude to his responsibility for a comprehensive and objective review of appeals.Take measures to prevent violations of the rights of citizens in the sphere of consideration of their applications, in particular, the introduction to the Code of the Russian Federation on Administrative offenses of article 5.59, not removed the relevance of the problem. As a rule, punishments under this article occur due to violation of the terms of consideration of appeals or even from evasion of giving a response to appeals, but the completeness and semantic load of the response itself are not studied. The author makes some suggestions for improving the effectiveness of interaction between people and authorities

Особенности строения биомедицинских сплавов Ti-Nb, полученных электродуговой плавкой и селективным лазерным сплавлением

Выявлено, что при электродуговой плавке и селективном лазерном сплавлении в сплаве Ti-Nb имеет место ликвация компонентов. На участках, обогащенных Nb образуется [beta]-фаза, на участках, обедненных Nb - [alpha]''-фаза. Для устранения неоднородности фазового и элементного состава рекомендуется повысить содержание Nb в сплаве до 45 мас. %

Ursodeoxycholic acid prevents ventricular conduction slowing and arrhythmia by restoring T-type calcium current in fetuses during cholestasis

Background Increased maternal serum bile acid concentrations in intrahepatic cholestasis of pregnancy (ICP) are associated with fetal cardiac arrhythmias. Ursodeoxycholic acid (UDCA) has been shown to demonstrate anti-arrhythmic properties via preventing ICP-associated cardiac conduction slowing and development of reentrant arrhythmias, although the cellular mechanism is still being elucidated. Methods High-resolution fluorescent optical mapping of electrical activity and electrocardiogram measurements were used to characterize effects of UDCA on one-day-old neonatal and adult female Langendorff-perfused rat hearts. ICP was modelled by perfusion of taurocholic acid (TC, 400μM). Whole-cell calcium currents were recorded from neonatal rat and human fetal cardiomyocytes. Results TC significantly prolonged the PR interval by 11.0±3.5% (P<0.05) and slowed ventricular conduction velocity (CV) by 38.9±5.1% (P<0.05) exclusively in neonatal and not in maternal hearts. A similar CV decline was observed with the selective T-type calcium current (ICa,T) blocker mibefradil 1μM (23.0±6.2%, P<0.05), but not with the L-type calcium current (ICa,L) blocker nifedipine 1μM (6.9±6.6%, NS). The sodium channel blocker lidocaine (30μM) reduced CV by 60.4±4.5% (P<0.05). UDCA co-treatment was protective against CV slowing induced by TC and mibefradil, but not against lidocaine. UDCA prevented the TC-induced reduction in the ICa,T density in both isolated human fetal (−10.2±1.5 versus −5.5±0.9 pA/pF, P<0.05) and neonatal rat ventricular myocytes (−22.3±1.1 versus −9.6±0.8 pA/pF, P<0.0001), whereas UDCA had limited efficacy on the ICa,L. Conclusion Our findings demonstrate that ICa,T plays a significant role in ICP-associated fetal cardiac conduction slowing and arrhythmogenesis, and is an important component of the fetus-specific anti-arrhythmic activity of UDCA

Изолированная резекция вены в хирургическом лечении протоковой карциномы поджелудочной железы как фактор резектабельности

Background. Pancreatic ductal carcinoma (PDC) with involvement of the superior mesenteric vein (SMV) or/ and portal vein (PV) remains a discussible subject. We have evaluated vein invasion as a criterion of borderline resectability and long-term outcome. Material and methods. In our center, 68 patients underwent either 65 standard pancreatoduodenal resections or 3 pancreatoduodenectomies for PDC. Resection of SMV/PV was performed in 18 cases (26.5 %). Three patients received neoadjuvant chemotherapy (NACT), and adjuvant chemotherapy (ACT) was assigned to 37 patients (54.4 %). Results. Morbidity (42.0 vs 50.0 %, р=0.590) and mortality rates (4.0 vs 16.7 %, р=0.111) had no significant differences in groups of standard and angioplasty operations respectively. ACT was completed in 10 (16.7 %) patients only. There was true vein invasion in 12 of 18 patients with vein resection. рN+ (р=0.012) and angioplasty by itself (р&lt;0.001) were found out as independent predictors of overall survival (OS). the median OS was 9.4 mo in patients with vein resection. in the group of standard operations, the median OS was 26.9 mo (р&lt;0.001). The median OS in patients with vein resection and complete chemotherapy was 17.7 mo in contrast to 8.9 mo in those who did not receive chemotherapy (р=0.439). Conclusions. PDR with vein resection and incomplete chemotherapy cannot be regarded as a reasonable procedure. PDR with vein resection may be appropriate after efficient NACT.Лечение протоковой карциномы поджелудочной железы (ПКПЖ) с вовлечением верхней брыжеечной и/или воротной вены остается предметом дискуссий. Мы оценили венозную инвазию как критерий пограничной резектабельности и отдаленного прогноза заболевания. Материал и методы. В нашем центре 68 пациентов оперированы в объеме стандартной панкреатодуоденальной резекции (n=65) или панкреатодуоденэктомии (n=3) по поводу ПКПЖ. В 18 (26,5 %) наблюдениях выполнена резекция верхней брыжеечной и/или воротной вены. Неоадъювантную химиотерапию (НАХТ) получили 3 пациента, адъювантная химиотерапия (АХТ) начата у 37 (54,4 %) пациентов. Результаты. Частота послеоперационных осложнений в группе стандартных операций и ангиопластических операций (42,0 против 50,0 %, р=0,590), частота летальных исходов (4 против 16,7 %, р=0,111) значимо не отличались. АХТ закончена полностью у 10 (16,7 %) пациентов. Истинная инвазия опухоли отмечена у 12 из 18 пациентов с резекцией вены. Независимыми предикторами общей выживаемости (ОВ) были рN+ (р=0,012) и наличие ангиопластики (р=0,000). У пациентов с резекцией вены медиана ОВ составила 9,4 мес. В группе стандартных ПДР медиана ОВ была 26,9 мес (р=0,000). У пациентов с резекцией вены медиана ОВ при законченной химиотерапии составила 17,7 мес, без химиотерапии – 8,9 мес (р=0,439). Заключение. ПДР с резекцией вены и отсутствием или незавершенной химиотерапией может рассматриваться как неоправданная операция. Данную операцию целесообразно выполнять после эффективной НАХТ

Альтернативный вариант реорганизации структуры воздушного пространства в московском узловом диспетчерском районе

The variant of Moscow TMA restructuration with ATM efficiency increasing justification is presented.Предлагается вариант реорганизации структуры воздушного пространства московского узлового диспетчерского района с обоснованием повышения эффективности организации воздушного движения (ОВД)