Phase distortions of attosecond pulses produced by resonance-enhanced high harmonic generation

Resonant enhancement of high harmonic generation can be obtained in plasmas containing ions with strong radiative transitions resonant with harmonic orders. The mechanism for this enhancement is still debated. We perform the first temporal characterization of the attosecond emission from a tin plasma under near-resonant conditions for two different resonance detunings. We show that the resonance considerably changes the relative phase of neighbouring harmonics. For very small detunings, their phase locking may even be lost, evidencing strong phase distortions in the emission process and a modified attosecond structure. These features are well reproduced by our simulations, allowing their interpretation in terms of the phase of the recombination dipole moment

The Comparative Analysis of the Identification of Parasitic Fungi Races Affecting the Soil and Cultivated Vegetable and Cucurbits Crops in the Astrakhan Region

The habitat of plant pathogens does not remain constant and undergoes significant changes. Therefore, the reasons have to be revealed: the emergence of fungal infectious matter in the soil; the infection source and rate, which may have epiphytotic character under environmental factors of the disease development and consequently lead to the reduction in the yield of vegetable and cucurbits crops. As a result, it is necessary to conduct monitoring and objective diagnosis of the phytosanitary condition of the planting of vegetables and melons. In this case, the identification of parasitic fungi races of the Astrakhan region remains relevant and timely

Does Giant Magnetoresistance Survive in Presence of Superconducting Contact?

The giant magnetoresistance (GMR) of ferromagnetic bilayers with a superconducting contact (F1/F2/S) is calculated in ballistic and diffusive regimes. As in spin-valve, it is assumed that the magnetization in the two ferromagnetic layers F1 and F2 can be changed from parallel to antiparallel. It is shown that the GMR defined as the change of conductance between the two magnetic configurations is an oscillatory function of the thickness of F2 layer and tends to an asymptotic positive value at large thickness. This is due to the formation of quantum well states in F2 induced by Andreev reflection at the F2/S interface and reflection at F1/F2 interface in antiparallel configuration. In the diffusive regime, if only spin-dependent scattering rates in the magnetic layers are considered (no difference in Fermi wave-vectors between spin up and down electrons) then the GMR is supressed due to the mixing of spin up and down electron-hole channels by Andreev reflection.Comment: 7 pages, 4 figures, submitted to Phys.Rev.Let

GRANIT project: a trap for gravitational quantum states of UCN

Previous studies of gravitationally bound states of ultracold neutrons showed the quantization of energy levels, and confirmed quantum mechanical predictions for the average size of the two lowest energy states wave functions. Improvements in position-like measurements can increase the accuracy by an order of magnitude only. We therefore develop another approach, consisting in accurate measurements of the energy levels. The GRANIT experiment is devoted to the study of resonant transitions between quantum states induced by an oscillating perturbation. According to Heisenberg's uncertainty relations, the accuracy of measurement of the energy levels is limited by the time available to perform the transitions. Thus, trapping quantum states will be necessary, and each source of losses has to be controlled in order to maximize the lifetime of the states. We discuss the general principles of transitions between quantum states, and consider the main systematical losses of neutrons in a trap.Comment: presented in ISINN 15 seminar, Dubn

К видовому разнообразию нематодофауны семейства Corvidae Vigors, 1825 в дельте реки Волги

The purpose of the research is to systematize the long-term data on study of nematode fauna of Corvidae family birds of Volga river delta. Materials and methods. Data of helminthological researches carried out during the period from 1936 to 2017 in different landscape zones of Volga river delta are included into the project. The study of the species composition of the nematode fauna was carried out based on analysis of own and literature data received during helminthological autopsy of the Corvidae family birds belonging to 3 species: hooded crow (Corvus cornix Linnaeus, 1758), rook (Corvus frugilegus Linnaeus, 1758), magpie (Picapica Linnaeus, 1758). Traditional methods were used during collection and handling of helminthological material (Skryabin, 1928; Dubinina, 1955). Nematodes have been fixed by the mixture made from equal parts of 70% alcohol, lactic acid and 50% glycerol, 4% formalin solution or in Barbagallo liquid. Nematodes have been identified by famous indicators. Results and discussion. 480 specimen of Corvidae family birds, 170 specimen of which had been infested by nematode worms, were investigated in order to study helminthofauna at Volga river delta from 1936 to nowadays. Having summarized the literature data with the results from own study of Corvidae family parasitophauna we have made a taxonomical list including 17 species of nematodes. During the period from 1976 to 2017 we have been discovering 3 species of nematodes for the first time: Microtetrameres helix (Cram, 1927) - in a rook, Oxyspirura sygmoidea (Molin, 1860) - in a rook, a magpie and a hooded crow, Pseudaprocta decorata (Li, 1933) - in a magpie. 2 species of nematodes have been registered in Corvidae family as in new hosts in the studied region too. Baruscapillaria corvorum (Rudolphi, 1819) - in a hooded crow, a magpie and Diplotriaena tricuspis (Fedtschenko, 1874) - in a hooded crow.Цель исследований: систематизировать многолетние данные по изучению нематодофауны врановых птиц дельты реки Волги. Материалы и методы. В работу включены сведения гельминтологических исследований, проводившихся в период с 1936 до 2017 гг. в различных ландшафтных зонах дельты реки Волги. Изучение видового состава нематодофауны проводили на основе анализа собственных и литературных данных, полученных при проведении гельминтологических вскрытий птиц семейства врановые, принадлежащих к 3 видам: ворона серая (Corvus cornix Linnaeus, 1758), грач (Corvus frugilegus Linnaeus, 1758), сорока (Pica pica Linnaeus, 1758). При сборе и обработке гельминтологического материала использованы традиционные методики (Скрябин, 1928; Дубинина, 1955). Нематод фиксировали смесью из равных частей 70%-ного спирта, молочной кислоты и 50%-ного глицерина, 4%-ным раствором формалина, или в жидкости Барбагалло. Нематод идентифицировали по известным определителям. Результаты и обсуждение. С 1936 г. по настоящее время в целях изучения гельминтофауны в дельте реки Волги исследовано 480 экз. врановых птиц, 170 из которых были инвазированы круглыми червями. Обобщив литературные данные с результатами собственных исследований паразитофауны врановых, нами составлен таксономический список, включающий 17 видов нематод. В период с 1976 до 2017 гг. у врановых нами впервые в регионе обнаружено 3 вида нематод: Microtetrameres helix (Cram, 1927) - у грача, Oxyspirura sygmoidea (Molin, 1860) - у грача, сороки и серой вороны, Pseudaprocta decorata (Li, 1933) - у сороки. Также, в исследуемом регионе 2 вида нематод зарегистрированы у врановых как у новых хозяев: Baruscapillaria corvorum (Rudolphi, 1819) - у серой вороны и сороки и Diplotriaena tricuspis (Fedtschenko, 1874) - у серой вороны

UCN anomalous losses and the UCN capture cross-section on material defects

Experimental data shows anomalously large Ultra Cold Neutrons (UCN) reflection losses and that the process of UCN reflection is not completely coherent. UCN anomalous losses under reflection cannot be explained in the context of neutron optics calculations. UCN losses by means of incoherent scattering on material defects are considered and cross-section values calculated. The UCN capture cross-section on material defects is enhanced by a factor of 10^4 due to localization of UCN around defects. This phenomenon can explain anomalous losses of UCN.Comment: 13 pages, 4 figure

SYNZIP Protein Interaction Toolbox: in Vitro and in Vivo Specifications of Heterospecific Coiled-Coil Interaction Domains

The synthetic biology toolkit contains a growing number of parts for regulating transcription and translation, but very few that can be used to control protein association. Here we report characterization of 22 previously published heterospecific synthetic coiled-coil peptides called SYNZIPs. We present biophysical analysis of the oligomerization states, helix orientations, and affinities of 27 SYNZIP pairs. SYNZIP pairs were also tested for interaction in two cell-based assays. In a yeast two-hybrid screen, >85% of 253 comparable interactions were consistent with prior in vitro measurements made using coiled-coil microarrays. In a yeast-signaling assay controlled by coiled-coil mediated scaffolding, 12 SYNZIP pairs were successfully used to down-regulate the expression of a reporter gene following treatment with α-factor. Characterization of these interaction modules dramatically increases the number of available protein interaction parts for synthetic biology and should facilitate a wide range of molecular engineering applications. Summary characteristics of 27 SYNZIP peptide pairs are reported in specification sheets available in the Supporting Information and at the SYNZIP Web site [http://keatingweb.mit.edu/SYNZIP/].National Science Foundation (U.S.) (NSF award MCB 0950233)National Institutes of Health (U.S.) (grant RO1 GM55040)National Institutes of Health (U.S.) (grant PN2 EY016546)National Institutes of Health (U.S.) (grant P50 GMO81879)National Science Foundation (U.S.). Synthetic Biology Engineering Research CenterHoward Hughes Medical Institut

“Hot standards” for the thermoacidophilic archaeon Sulfolobus solfataricus

Within the archaea, the thermoacidophilic crenarchaeote Sulfolobus solfataricus has become an important model organism for physiology and biochemistry, comparative and functional genomics, as well as, more recently also for systems biology approaches. Within the Sulfolobus Systems Biology (“SulfoSYS”)-project the effect of changing growth temperatures on a metabolic network is investigated at the systems level by integrating genomic, transcriptomic, proteomic, metabolomic and enzymatic information for production of a silicon cell-model. The network under investigation is the central carbohydrate metabolism. The generation of high-quality quantitative data, which is critical for the investigation of biological systems and the successful integration of the different datasets, derived for example from high-throughput approaches (e.g., transcriptome or proteome analyses), requires the application and compliance of uniform standard protocols, e.g., for growth and handling of the organism as well as the “–omics” approaches. Here, we report on the establishment and implementation of standard operating procedures for the different wet-lab and in silico techniques that are applied within the SulfoSYS-project and that we believe can be useful for future projects on Sulfolobus or (hyper)thermophiles in general. Beside established techniques, it includes new methodologies like strain surveillance, the improved identification of membrane proteins and the application of crenarchaeal metabolomics

The Regulation of Skeletal Muscle Protein Turnover during the Progression of Cancer Cachexia in the ApcMin/+ Mouse

Muscle wasting that occurs with cancer cachexia is caused by an imbalance in the rates of muscle protein synthesis and degradation. The ApcMin/+ mouse is a model of colorectal cancer that develops cachexia that is dependent on circulating IL-6. However, the IL-6 regulation of muscle protein turnover during the initiation and progression of cachexia in the ApcMin/+ mouse is not known. Cachexia progression was studied in ApcMin/+ mice that were either weight stable (WS) or had initial (≤5%), intermediate (6–19%), or extreme (≥20%) body weight loss. The initiation of cachexia reduced %MPS 19% and a further ∼50% with additional weight loss. Muscle IGF-1 mRNA expression and mTOR targets were suppressed with the progression of body weight loss, while muscle AMPK phosphorylation (Thr 172), AMPK activity, and raptor phosphorylation (Ser 792) were not increased with the initiation of weight loss, but were induced as cachexia progressed. ATP dependent protein degradation increased during the initiation and progression of cachexia. However, ATP independent protein degradation was not increased until cachexia had progressed beyond the initial phase. IL-6 receptor antibody administration prevented body weight loss and suppressed muscle protein degradation, without any effect on muscle %MPS or IGF-1 associated signaling. In summary, the %MPS reduction during the initiation of cachexia is associated with IGF-1/mTOR signaling repression, while muscle AMPK activation and activation of ATP independent protein degradation occur later in the progression of cachexia. IL-6 receptor antibody treatment blocked cachexia progression through the suppression of muscle protein degradation, while not rescuing the suppression of muscle protein synthesis. Attenuation of IL-6 signaling was effective in blocking the progression of cachexia, but not sufficient to reverse the process