“Tie Calorimetry” as a Tool for Determination of Thermodynamic Parameters of Macromolecules

Determination of free energy of double helix formation from two single-stranded polynucleotides and estimation of energetics of different low-molecular compounds binding to nucleic acids provide valuable tools for understanding of mechanisms that govern noncovalent binding of ligands to their receptor targets. In order to completely understand the molecular forces that drive and stabilize double helix formation and its complexes with ligands, thermodynamic studies are needed to complement the structural data. Structural characterization of a number of DNA-ligand complexes by X-ray and high-resolution NMR method provides key insight relating to the properties of complex formation, but structural data alone, even when coupled with the most sophisticated current computational methods, cannot fully define the driving forces for binding inte-ractions (or interac-tions) or even accurately predict their binding affinities. Thermodynamics provides quantitative data of use in elucidating these driving forces and for evaluating and understanding at a deeper level the effects of substituent changes on binding affinity

Increase in temperature induces the Z to B transition of poly[d(G-C)] in water-ethanol solution

AbstractAn increase in temperature from 20 to 50° C results in the complete transition from the Z to B form of poly(d(G-C)], dissolved in a 55% ethanol-water solution. The transition is fully reversible and displays a slow kinetics. The transition profiles for the free polynucleotide and for that in the presence of ethidium bromide, which is known to stabilize the B form, are obtained by circular dichroism. Based on these data the enthalpy value for the B-Z transition in our conditions is estimated to be ΔHBZ = −0.7 kcalmol

Measurements of energy spectra of relativistic electrons and gamma-rays from avalanches developed in the thunderous atmosphere with Aragats Solar Neutron Telescope

Aragats solar neutron telescope (ASNT) is a unique instrument allowing to measure the energy spectra of electrons accelerated and multiplied in the strong electric fields of the atmosphere. We describe the instrument setup, its operation condition, software, and hardware triggers. We present energy spectra of a very large thunderstorm ground enhancement (TGE) event observed on 6 October 2021. The detector response function, algorithm to recover energy spectra from the energy release histograms also are presented. The spectra recovery procedure is verified by simulation of the response function of the SEVAN detector, operating nearby ASNT. SEVAN is a stacked 3 layered detector, interlayered by lead filters registering both charged and neutral species of cosmic rays. The simulated and measured count rates of all 3 layers of the SEVAN detector show good agreement within 20%

Satellite downlink scheduling problem: A case study

The synthetic aperture radar (SAR) technology enables satellites to efficiently acquire high quality images of the Earth surface. This generates significant communication traffic from the satellite to the ground stations, and, thus, image downlinking often becomes the bottleneck in the efficiency of the whole system. In this paper we address the downlink scheduling problem for Canada's Earth observing SAR satellite, RADARSAT-2. Being an applied problem, downlink scheduling is characterised with a number of constraints that make it difficult not only to optimise the schedule but even to produce a feasible solution. We propose a fast schedule generation procedure that abstracts the problem specific constraints and provides a simple interface to optimisation algorithms. By comparing empirically several standard meta-heuristics applied to the problem, we select the most suitable one and show that it is clearly superior to the approach currently in use.Comment: 23 page

КОМПЛЕКСНІ БІЗНЕС-РІШЕННЯ З ОЦІНКИ ТА УПРАВЛІННЯ РИЗИКОМ У РИТЕЙЛІ

Retail companies are largely addicted to the risk of economic activity due to their industry specifics, which requires them to focus on a comprehensive study of the problem of risk. The purpose of the article is to investigate the operational and financial leverage in terms of using its capabilities to manage the risks of the retail company. The task, the decision of which is aimed at researching this article, is to improve the methodical tools of integrated assessment and risk management in the economic cycle of retail companies in the process of asset conversion. The research of the conditions for the formation of operational and financial leverage in retail companies showed that the calculation of analytical indicators for their assessment has methodological features, due to the structure and nature of used material and financial resources, as well as the formation of effective indicators of economic activity. Under research, it was confirmed the hypothesis of the possibility of comprehensive assessment and risk management of retail companies on the basis of analysis of the variability of profit and the impact on the process of its risks’ generating associated with the use efficiency of assets and capital of the enterprise by calculating the combined effect of the operational and financial leverage. For the reasoned adoption of effective business decisions and ensuring the comprehensiveness of risk assessment and risk management in retail, the proposed methodological approach, which involves the calculation of the cumulative effect of operational and financial leverage, as well as its components, adapted to the specifics of the retail. The research of combined operational and financial risk using the proposed scientific methodological approach has confirmed its effectiveness and correctness of the hypothesis about the need to reflect in the analytical calculations of use in the trade and technological process of retail companies operating lease objects and the value of trade payables.В статье обоснован научно-методический подход к комплексной оценке и управлению риском с использованием методического инструментария расчета совокупного эффекта операционно-финансового левериджа. Определены особенности формирования совокупного эффекта операционно-финансового левериджа в ритейле и предложена адаптированная модель его расчета с учетом отраслевой специфики. Подтверждена эффективность предложеного научно-методического подхода и правильность выдвинутой гипотезы относительно необходимости отражения в аналитических расчетах использования в торгово-технологическом процессе предприятий ритейла объектов оперативной аренды и стоимости кредиторской задолженности товарного характера.Підприємства рітейлу значною мірою схильні до ризику господарської діяльності в силу галузевої специфіки, яка вимагає від них зосередження уваги на всебічному вивченні проблеми ризику. Мета статті полягає в дослідженні операційно-фінансового левериджу з точки зору використання його можливостей для управління ризиками підприємства рітейлу. Завдання, на вирішення якого спрямовано дослідження даної статті полягає у вдосконаленні методичного інструментарію комплексної оцінки та управління ризиком в господарському циклі підприємств рітейлу в процесі конверсії активів. Дослідження умов формування операційного і фінансового левериджів в підприємствах рітейлу показало, що розрахунок аналітичних показників для їх оцінки має методичні особливості, обумовлені складом та характером використовуваних матеріальних і фінансових ресурсів, а також формуванням результативних показників господарської діяльності. У процесі досліджень була підтверджена гіпотеза можливості комплексної оцінки й управління ризиком підприємств рітейлу на основі аналізу варіабельності прибутку та впливу на процес його генерування ризиків, пов'язаних з ефективністю використання активів і капіталу підприємства шляхом розрахунку сполученого ефекту операційно-фінансового левериджу. Для обґрунтованого прийняття ефективних бізнес-рішень і забезпечення комплексності оцінки та управління ризиком в ритейлі запропонований науково-методичний підхід, який передбачає розрахунок сукупного ефекту операційного та фінансового левериджу, а також його складових, адаптований до специфіки рітейлу. Дослідження сукупного операційно-фінансового ризику з використанням запропонованого науково-методичного підходу підтвердило його ефективність і правильність висунутої гіпотези щодо необхідності відображення в аналітичних розрахунках використання в торгово-технологічному процесі підприємств рітейлу об'єктів оперативної оренди та вартості кредиторської заборгованості товарного характеру

The horizontal profile of the atmospheric electric fields as measured during thunderstorms by the network of NaI spectrometers located on the slopes of Mt. Aragats

The International School for Advanced Studies (SISSA), find out more paper The horizontal profile of the atmospheric electric fields as measured during thunderstorms by the network of NaI spectrometers located on the slopes of Mt. Aragats A. Chilingarian1, G. Hovsepyan1, T. Karapetyan1, L. Kozliner1, S. Chilingaryan1, D. Pokhsraryan1 and B. Sargsyan1 Published 6 October 2022 • © 2022 IOP Publishing Ltd and Sissa Medialab Journal of Instrumentation, Volume 17, October 2022 Citation A. Chilingarian et al 2022 JINST 17 P10011 DOI 10.1088/1748-0221/17/10/P10011 Download Article PDF References 21 Total downloads Article has an altmetric score of 1 Turn on MathJax Get permission to re-use this article Share this article Share this content via email Share on Facebook (opens new window) Share on Twitter (opens new window) Share on Mendeley (opens new window) Article information Abstract The shape and evolution of the energy spectra of the thunderstorm ground enhancement (TGE) electrons and gamma rays shed light on the origin of TGEs, on the relationship between modification of the cosmic ray electron energy spectra (MOS) and relativistic runaway electron avalanche (RREA) processes, on the energy of the seed electrons, and on the strength and elongation of an atmospheric electric field. The network of large NaI spectrometers on slopes of Mt. Aragats 24/7 monitored secondary particle fluxes from 2013 until now, highly contributed to the understanding of the ways how RREAs are developed in the atmosphere. In 2022 we enlarge the NaI network with 2 remote detectors located at altitudes 2000 and 1700 m, and 13 and 16 km apart from the Aragats station to investigate the horizontal profile of the atmospheric electric field. We found, that the previously estimated values of the regions in the atmosphere, where RREA emerges, were highly underestimated. In the present report, we describe the NaI particle detector\u27s network and present the first results of the experiment demonstrating that the particle fluxes from the atmospheric electron accelerators can cover large areas on the earth\u27s (up to tens of km$^{2}$)

Multi-messenger observations of thunderstorm-related bursts of cosmic rays

We present the facilities of the Aragats Space Environmental Center in Armenia used during multi-year observations of the thunderstorm ground enhancements (TGEs) and corresponding environmental parameters. We analyze the characteristics of the scintillation detectors, operated on Aragats, and describe the coordinated detection of TGEs by the network of scintillation detectors, field meters, and environmental parameters. By using a fast synchronized data acquisition system we reveal correlations of the multivariate data on time scales from second to nanosecond which allow us to gain insight into the TGE and lightning origin and their interrelations

Quantum theory of resonantly enhanced four-wave mixing: mean-field and exact numerical solutions

We present a full quantum analysis of resonant forward four-wave mixing based on electromagnetically induced transparency (EIT). In particular, we study the regime of efficient nonlinear conversion with low-intensity fields that has been predicted from a semiclassical analysis. We derive an effective nonlinear interaction Hamiltonian in the adiabatic limit. In contrast to conventional nonlinear optics this Hamiltonian does not have a power expansion in the fields and the conversion length increases with the input power. We analyze the stationary wave-mixing process in the forward scattering configuration using an exact numerical analysis for up to $10^3$ input photons and compare the results with a mean-field approach. Due to quantum effects, complete conversion from the two pump fields into the signal and idler modes is achieved only asymptotically for large coherent pump intensities or for pump fields in few-photon Fock states. The signal and idler fields are perfectly quantum correlated which has potential applications in quantum communication schemes. We also discuss the implementation of a single-photon phase gate for continuous quantum computation.Comment: 10 pages, 11 figure

Dynamics of the Tippe Top -- properties of numerical solutions versus the dynamical equations

We study the relationship between numerical solutions for inverting Tippe Top and the structure of the dynamical equations. The numerical solutions confirm oscillatory behaviour of the inclination angle $\theta(t)$ for the symmetry axis of the Tippe Top. They also reveal further fine features of the dynamics of inverting solutions defining the time of inversion. These features are partially understood on the basis of the underlying dynamical equations