Introducing nuclear spin-noise spectroscopy

International audienceNMR spectra are usually obtained by exciting, through a rf field, the nuclear magnetization and then by monitoring the induction, it creates. An alternative approach, named spin noise, exists: it consists in searching for correlations in the noise signal at the probe detection output, a concept up to now used for only a single spin species. Here, we report its extension for looking to small signals in the presence of a major one and show that this technique allows sensitivity enhancement for their detection, in particular when the temperature of detection coil is lower than that of the sample. Signals resulting from small species appear as bumps, superimposed on the dip which results from the main component contribution. For the description and the processing of the experimental spectra, a new analytical equation is introduced. Its derivation is based on fluctuating rf fields due to the preamplifier and coil resistances and magnetization fluctuations and coherent rf field due to the feedback field (radiation damping). Its generality allows analytical explanation of the difference of tuning conditions and the treatment of static magnetic field inhomogeneity, which has an enhanced spectral signature in spin-noise spectra and provides a chemical shift reference. We have combined all these aspects and proved the enhanced detection capability of the nuclear spin-noise approach for characterizing secondary isotopic effect, proving the opening of a new "spin-noise" spectroscopy. Perspectives of this work in terms of classical NMR in the presence of radiation damping but also in terms of unconventional detection scheme will be discussed

"Tomography" of the cluster structure of light nuclei via relativistic dissociation

These lecture notes present the capabilities of relativistic nuclear physics for the development of the physics of nuclear clusters. Nuclear track emulsion continues to be an effective technique for pilot studies that allows one, in particular, to study the cluster dissociation of a wide variety of light relativistic nuclei within a common approach. Despite the fact that the capabilities of the relativistic fragmentation for the study of nuclear clustering were recognized quite a long time ago, electronic experiments have not been able to come closer to an integrated analysis of ensembles of relativistic fragments. The continued pause in the investigation of the "fine" structure of relativistic fragmentation has led to resumption of regular exposures of nuclear emulsions in beams of light nuclei produced for the first time at the Nuclotron of the Joint Institute for Nuclear Research (JINR, Dubna). To date, an analysis of the peripheral interactions of relativistic isotopes of beryllium, boron, carbon and nitrogen, including radioactive ones, with nuclei of the emulsion composition, has been performed, which allows the clustering pattern to be presented for a whole family of light nuclei.Comment: ISBN 978-3-319-01076-2. 55 pages, 28 figure

Pre-trial agreement and plea bargain: pragmatism without conflict with morality?

A comparative legal analysis of plea bargain in the continental Europe, England and the USA is conducted. The history of the plea bargain emergence in common law is examined, its features are shown. Such agreements to plead guilty are often reached after bringing a charge. The freedom of agreement is guaranteed by the powers of police, court and public prosecutor to decide on the severity of the charge, its change or dismissal (partial or complete). An obvious “conflict of interests” is shown: the economic benefit of plea agreement is complicated by ignoring the public morality principles. It doesn’t allow to use the same form of plea bargain in the Russian realities: the essence of the pre-trial agreement institute doesn’t imply that the defendant pleads guilty, but contributes to solving a crime (disclosure of information about accomplices, compensation for damage). The proposals to improve the regulation of the Russian pre-trial cooperation agreement are made. The foreign models of plea bargain are studied: German, French, Spanish, Italian and Portuguese. Their comparison allows to conclude that such deal can be used in different national legal systems and in various models of criminal procedure. It’s argued that the institution of pre-trial agreement is the objective response of the Russian law enforcement bodies to modern challenges. American model of plea bargain can be considered optimal despite its shortcomings. Other states don’t accept it unchanged. Russia also has to transform the western model of plea bargain, taking into account the requirements of the domestic legal culture

Yeast red pigment modifies Amyloid beta growth in Alzheimer disease models in both Saccharomyces cerevisiae and Drosophila melanogaster

The effect of yeast red pigment on amyloid-β (Aβ) aggregation and fibril growth was studied in yeasts, fruit flies and in vitro. Yeast strains accumulating red pigment (red strains) contained less amyloid and had better survival rates compared to isogenic strains without red pigment accumulation (white strains). Confocal and fluorescent microscopy was used to visualise fluorescent Aβ-GFP aggregates. Yeast cells containing less red pigment had more Aβ-GFP aggregates despite the lower level of overall GFP fluorescence. Western blot analysis with anti-GFP, anti-Aβ and A11 antibodies also revealed that red cells contained a considerably lower amount of Aβ GFP aggregates as compared to white cells. Similar results were obtained with exogenous red pigment that was able to penetrate yeast cells. In vitro experiments with thioflavine and TEM showed that red pigment effectively decreased Aβ fibril growth. Transgenic flies expressing Aβ were cultivated on medium containing red and white isogenic yeast strains. Flies cultivated on red strains had a significant decrease in Aβ accumulation levels and brain neurodegeneration. They also demonstrated better memory and learning indexes and higher locomotor abilit

Application of the Temetos software platform to electromagnetic accelerator simulation environment development

Abstract: The advance in the architecture of software platform Temetos for computing experiment supply is presented. The basic module of the platform and the system of subject libraries are described. The main principles of the platform development providing its painless growth and flexibility in adapting to various problems of mathematical modeling are presented. The experience of using the platform to develope a software environment for simulating an electromagnetic accelerator is described. An example of a calculation prepared using the developed software environment is given.Note: Research direction:Mathematical modelling in actual problems of science and technic