История и современность кафедры ботаники, физиологии растений и агробиотехнологии

The article presents the formation and development history, modern educational and scientific activity of the Chair of botany, plant physiology and agrobiotechnology - the oldest chair of the Agrarian faculty of PFUR.В статье представлена история становления и развития, а также современная образовательная и научная деятельность кафедры ботаники, физиологии растений и агробиотехнологии - старейшей кафедры аграрного факультета РУДН

Оценка антиоксидантного потенциала лекарственных растений при действии Уф-B-облучения

The UV-B irradiation action (6 -36,9 dg/m2) on medical plants Artemisia lerchiana L., Nigella sativa L., Ocimum basilicum L., grown in water culture, was studying. In plant leaves and roots the content of malondialdehyde, pigments, phenols, flavonoids, proline, and activities of antioxidant enzymes were determined. Investigated plants were able to resist to action of UV-B-irradiation (low and middle dose) without any power input for increasing of biosynthesis of low and high molecular component of antioxidant defense system. The damage level under stress conditions was low. At first hours plants used the constitutive level of antioxidants and after 24 h it was needed the antioxidant pool refilling. Carotinoids, flavonoids and proline were used by plants in 4 h after irradiation, the antocian synthesis increased after 12 h.В статье рассматривается методика изучения действия УФ-B-облучения (6,0, 12,3 и 36,9 Дж/кв. м) на лекарственные растения: полынь Artemisia lerchiana L., чернушку Nigella sativa L., базилик Ocimum basilicum L., выращенные в водной культуре в условиях фитотрона. Исследованные растения способны адаптироваться к действию низкой и средней доз УФ-B-радиации без значительных энергозатрат на усиление биосинтеза как низкомолекулярных компонентов антиоксидантной защиты, так и высокомолекулярных. Степень повреждения растений при действии данного стрессора незначительна. В первые часы растения в основном использовали конститутивный уровень антиоксидантов, и лишь через 24 часа требовалось пополнение их пула. Каротиноиды, флавоноиды и пролин используются растениями уже через 4 часа после облучения, синтез антоцианов усиливается через 12 ч

Участие антиоксидантной защитной системы базилика в кросс-адаптации при комплексном действии УФ-В и засоления

The 10 min UV-B irradiation (12 dj/m2) and 100mM NaCl action on medical plants Ocimum basilicum L., grown in water culture, was studying. The plants treated by UV-B irradiation were more resistent to salinity. There were two groups of compounds. One - proline, carotinoids, phenols are accumulated under salinity conditions. Second group - pigments - antocyans and flavones. Its biosynthesis is stimulated by UV-B irradiation. Under complex stressor action pigments were increased and this increasing helped plants to overcome the high salinity. The antioxidant enzyme superoxid dismutase did not play essential role in adaptive response. The low molecular weight antioxidants were more effective for formation of adaptation response. The peroxidase activity had not correlation with superoxid dismutase activity and we supposed that H2O2 could be result of other process and served as signal molecul.На основании полученных данных можно сделать главный вывод о том, что обработка УФ-В в течение 10 мин. способствовала адаптации растений базилика к действию 100 мМ NaCl. Улучшение адаптационной способности базилика при совместном действии УФ-В и засоления и связано со стимулированием биосинтеза пигментов и низкомолекулярных антиоксидантов УФ-В облучением

Hidden attractors in fundamental problems and engineering models

Recently a concept of self-excited and hidden attractors was suggested: an attractor is called a self-excited attractor if its basin of attraction overlaps with neighborhood of an equilibrium, otherwise it is called a hidden attractor. For example, hidden attractors are attractors in systems with no equilibria or with only one stable equilibrium (a special case of multistability and coexistence of attractors). While coexisting self-excited attractors can be found using the standard computational procedure, there is no standard way of predicting the existence or coexistence of hidden attractors in a system. In this plenary survey lecture the concept of self-excited and hidden attractors is discussed, and various corresponding examples of self-excited and hidden attractors are considered

An Extreme Solar Event of 20 January 2005: Properties of the Flare and the Origin of Energetic Particles

The extreme solar and SEP event of 20 January 2005 is analyzed from two perspectives. Firstly, we study features of the main phase of the flare, when the strongest emissions from microwaves up to 200 MeV gamma-rays were observed. Secondly, we relate our results to a long-standing controversy on the origin of SEPs arriving at Earth, i.e., acceleration in flares, or shocks ahead of CMEs. All emissions from microwaves up to 2.22 MeV line gamma-rays during the main flare phase originated within a compact structure located just above sunspot umbrae. A huge radio burst with a frequency maximum at 30 GHz was observed, indicating the presence of a large number of energetic electrons in strong magnetic fields. Thus, protons and electrons responsible for flare emissions during its main phase were accelerated within the magnetic field of the active region. The leading, impulsive parts of the GLE, and highest-energy gamma-rays identified with pi^0-decay emission, are similar and correspond in time. The origin of the pi^0-decay gamma-rays is argued to be the same as that of lower energy emissions. We estimate the sky-plane speed of the CME to be 2000-2600 km/s, i.e., high, but of the same order as preceding non-GLE-related CMEs from the same active region. Hence, the flare itself rather than the CME appears to determine the extreme nature of this event. We conclude that the acceleration, at least, to sub-relativistic energies, of electrons and protons, responsible for both the flare emissions and the leading spike of SEP/GLE by 07 UT, are likely to have occurred simultaneously within the flare region. We do not rule out a probable contribution from particles accelerated in the CME-driven shock for the leading GLE spike, which seemed to dominate later on.Comment: 34 pages, 14 Postscript figures. Solar Physics, accepted. A typo corrected. The original publication is available at http://www.springerlink.co

Radio Observations of the January 20, 2005 X-Class Event

We present a multi-frequency and multi-instrument study of the 20 January 2005 event. We focus mainly on the complex radio signatures and their association with the active phenomena taking place: flares, CMEs, particle acceleration and magnetic restructuring. As a variety of energetic particle accelerators and sources of radio bursts are present, in the flare-ejecta combination, we investigate their relative importance in the progress of this event. The dynamic spectra of {Artemis-IV-Wind/Waves-Hiras with 2000 MHz-20 kHz frequency coverage, were used to track the evolution of the event from the low corona to the interplanetary space; these were supplemented with SXR, HXR and gamma-ray recordings. The observations were compared with the expected radio signatures and energetic-particle populations envisaged by the {Standard Flare--CME model and the reconnection outflow termination shock model. A proper combination of these mechanisms seems to provide an adequate model for the interpretation of the observational data.Comment: Accepted for publication in Solar Physic

Photoproduction of mesons off nuclei

Recent results for the photoproduction of mesons off nuclei are reviewed. These experiments have been performed for two major lines of research related to the properties of the strong interaction. The investigation of nucleon resonances requires light nuclei as targets for the extraction of the isospin composition of the electromagnetic excitations. This is done with quasi-free meson photoproduction off the bound neutron and supplemented with the measurement of coherent photoproduction reactions, serving as spin and/or isospin filters. Furthermore, photoproduction from light and heavy nuclei is a very efficient tool for the study of the interactions of mesons with nuclear matter and the in-medium properties of hadrons. Experiments are currently rapidly developing due to the combination of high quality tagged (and polarized) photon beams with state-of-the-art 4pi detectors and polarized targets