Giant molecular clouds as regions of particle acceleration

One of the most interesting results of investigations carried out on the satellites SAS-II and COS-B is the discovery of unidentified discrete gamma sources. Possibly a considerable part of them may well be giant molecular clouds. Gamma emission from clouds is caused by the processes with participation of cosmic rays. The estimation of the cosmic ray density in clouds has shown that for the energy E approx. = I GeV their density can 10 to 1000 times exceed the one in intercloud space. We have made an attempt to determine the mechanism which could lead to the increase in the cosmic ray density in clouds

Circular dichroism at equal energy sharing in photo-double-ionization of He

Interference between dipole and quadrupole transition amplitudes in photo-double-ionization of He by an elliptically polarized vuv photon is shown to induce circular dichroism in the case of equal energy sharing. The magnitude of this retardation-induced dichroic effect is estimated and its impact on the nondipole asymmetries of the triply differential cross section is demonstrated

Does Pulsar B1757--24 Have a Fallback Disk?

Radio pulsars are thought to spin-down primarily due to torque from magnetic dipole radiation (MDR) emitted by the time-varying stellar magnetic field as the star rotates. This assumption yields a `characteristic age' for a pulsar which has generally been assumed to be comparable to the actual age. Recent observational limits on the proper motion of pulsar B1757-24, however, revealed that the actual age (>39 kyr) of this pulsar is much greater than its MDR characteristic age (16 kyr) - calling into question the assumption of pure MDR spin-down for this and other pulsars. To explore the possible cause of this discrepancy, we consider a scenario in which the pulsar acquired an accretion disk from supernova ejecta, and the subsequent spin-down occurred under the combined action of MDR and accretion torques. A simplified model of the accretion torque involving a constant mass inflow rate at the pulsar magnetosphere can explain the age and period derivative of the pulsar for reasonable values of the pulsar magnetic field and inflow rate. We discuss testable predictions of this model.Comment: Accepted by ApJ Letters. 15 pages with 1 figur

Transnational policy networks and change through internationalization (The Record of Project 5-100)

This article considers the ideational and political contexts in which Project 5-100, the Russian excellence in higher education initiative emerged, as well as the specificities of its organisational and behavioural model. While Project 5-100 has been studied in the academic literature as regards its efficiency and how it affected the performance and inner workings of the participating universities, the question of how the project came about and the characteristic traits of its internal set-up still remain largely overlooked. The study focuses on the involvement of local and international players, arguing that their successful and organic cooperation influenced both the architecture and the implementation of the project. This paper contributes to the literature on policy networks by showing that transnational actors do not necessarily undermine or challenge state power and can on the contrary help governments implement systemic change. Inspired by the international experience of establishing world-class universities, Project 5-100 was conceived and lobbied by a small but influential group of visionaries pushing for change who – acting in a concerted and purposive manner – acquired a novel and powerful capacity to use international expertise for the development of a key national project, capable of deeply transforming the country’s higher educational system

The Duck Redux: An Improved Proper Motion Upper Limit for the Pulsar B1757-24 Near the Supernova Remnant G5.4-1.2

"The Duck" is a complicated non-thermal radio system, consisting of the energetic radio pulsar B1757-24, its surrounding pulsar wind nebula G5.27-0.90 and the adjacent supernova remnant (SNR) G5.4-1.2. PSR B1757-24 was originally claimed to be a young (~15 000 yr) and extreme velocity (>~1500 km/s) pulsar which had penetrated and emerged from the shell of the associated SNR G5.4-1.2, but recent upper limits on the pulsar's motion have raised serious difficulties with this interpretation. We here present 8.5 GHz interferometric observations of the nebula G5.27-0.90 over a 12-year baseline, doubling the time-span of previous measurements. These data correspondingly allow us to halve the previous upper limit on the nebula's westward motion to 14 milliarcseconds/yr (5-sigma), allowing a substantive reevaluation of this puzzling object. We rule out the possibility that the pulsar and SNR were formed from a common supernova explosion ~15 000 yrs ago as implied by the pulsar's characteristic age, but conclude that an old (>~70 000 yr) pulsar / SNR association, or a situation in which the pulsar and SNR are physically unrelated, are both still viable explanations.Comment: 9 pages, including 1 color and 1 B/W figure. Minor changes following referee's report. ApJ, in pres

The effect of hypoxia on photocytotoxicity of tics tricaebocyanine dye in vitro

To evaluate the effect of cell oxygenation on photocytotoxicity of a novel tricarbocyanine indolenine dye covalently bound to glucose (TICS). Methods: HeLa cells were incubated with 5 µM TICS, 2 h later irradiated by laser at 740 nm with a light dose of 10 J/cm2, delivered at a power density of 10, 20, 25 or 30 mW/cm2, in air or in argon atmosphere, and then scored for viability. Results: The photocytotoxicity of TICS increased dramatically as the power density was reduced. Under hypoxia TICS-photosensitized cell death was determined but its value was lowered, compared to photoirradiation in the air. Conclusion: Photosensitizing effect of TICS is only partially dependent on the oxygenation of tumor cells

Immediate results of surgical treatment of gastric cancer with the presence of free tumor cells in the peritoneal fluid with intraoperative hyperthermic intraperitoneal chemical perfusion

Short-term results ot radical surgical treatment ot a carcinoma ot the stomach at 142 patients by whom the cytologic analysis of washouts from a peritoneum intraoperative. Positive there were 58 cases that has compounded 40.8 %. In the same bunch to 20 patients radical surgical treatment is added hyperthermic intraperitoneal intraoperative chemotherapy. A postoperative mortality it is noted, postoperative morbidity have compounded 7 %.Проанализированы непосредственные результаты радикального хирургического лечения рака желудка у 142 больных, которым проведен цитологический анализ смывов с брюшины интраоперационно. Положительными оказались 58 случаев, что составило 40.8%. В зтой же группе 20 пациентам радикальное хирургическое лечение дополнено интраоперационной внутрибрюшной гипертермической химиоперфузией. Послеоперационной летальности не отмечено, послеоперационные осложнения составили 7%