Full Repression of RNA Polymerase III Transcription Requires Interaction between Two Domains of Its Negative Regulator Maf1

Maf1, first identified in yeast Saccharomyces cerevisiae, is a general negative regulator of RNA polymerase III (Pol III). Transcription regulation by Maf1 is important under stress conditions and during the switch between fermentation and respiration. Maf1 is composed of two domains conserved during evolution. We report here that these two domains of human Maf1 are resistant to mild proteolysis and interact together as shown by pull-down and size-exclusion chromatography and that the comparable domains of yeast Maf1 interact in a two-hybrid assay. Additionally, in yeast, a mutation in the N-terminal domain is compensated by mutations in the C-terminal domain. Integrity of both domains and their direct interaction are necessary for Maf1 dephosphorylation and subsequent inhibition of Pol III transcription on a nonfermentable carbon source. These data relate Pol III transcription inhibition to Maf1 structural changes

Resonant Einstein-de Haas effect in a rubidium condensate

We numerically investigate a condensate of $^{87}$Rb atoms in an F=1 hyperfine state confined in an optical dipole trap. Assuming the magnetic moments of all atoms are initially aligned along the magnetic field we observe, after the field's direction is reversed, a transfer of atoms to other Zeeman states. Such transfer is allowed by the dipolar interaction which couples the spin and the orbital degrees of freedom. Therefore, the atoms in $m_F=0,-1$ states acquire an orbital angular momentum and start to circulate around the center of the trap. This is a realization of the Einstein-de Haas effect in systems of cold gases. We find resonances which amplify this phenomenon making it observable even in very weak dipolar systems. The resonances occur when the Zeeman energy on transfer of atoms to $m_F=0$ state is fully converted to the rotational kinetic energy.Comment: 4 pages, 5 figure

ІННОВАЦІЇ ЦЕ РУШІЙНА СИЛА? ОЦІНКА І КОНТРОЛЬ ДЛЯ ЄС, ПОЛЬЩІ ТА УКРАЇНИ

The aim of the article is to present condition of innovativeness for Poland as Moderate innovator and Ukraine as modest inovator. The essence and role of innovation was observed for contemporary world economy. The data assessment has been provided in the over last 7 years, it means in period from the year 2010 to 2017. Innovation of the Polish and Ukrainian economies was analyzed on the basis of 27 particular indicators. The method of comparative analysis was used to pursue the adopted aim. Performance for Ukraine and Poland was analyzed and controlled relative to European Union 2017 and 2010. The latest and the most reliable assessment tool, i.e. Innovation Scoreboard2018, a regular document prepared upon the request of Directorate-General for Enterprise and Industry, European Commission was used to conduct the analysis. The analysis of the dynamics was carried out and the main trends were revealed for innovation in composite indicators. Despite the fact the EU is the obvious leader, Poland which in fact is the part of it, in certain indexes approached EU’s performance. In those indexes as innovation-friendly environment, employment impacts and firm investments Poland being a part of the EU became almost equal to it.Ukraine is the best in Human resource index among all of them but has the worst intellectual assets index. The most significant rise was in the EU in innovation-friendly environment index. Assessment and recommendations for raising innovativeness were formed for the analyzed economies. As a result, reasons of significant difference between Ukraine and Poland were identified. Ukraine is in the ‘Modest Innovators’ group with the worst indicator. In contrast to Ukraine, Poland is one of the ‘Moderate innovators’ with almost twice as big as Ukrainian index. The complex approach to use innovation as driving force for economies must include: increase of the level and efficiency of education at schools and universities; research and development of modern technologies; increase of conditions of running economic activity, adequate building of capital for innovation as well as regular increase of expenditures on R&D move to the strategy of creation of own knowledge, creation of competitive advantage based on the latest innovative achievements thus launching original, own solutions and fresh knowledge on the global market.Цель статьи — представить состояние инноваций для Польши как умеренного новатора и Украины как скромного новатора. Сущность и роль инноваций была исследована для современной мировой экономики. Инновации экономики Польши и Украины были проанализированы на основе 27 конкретных показателей по отношению к Европейскому Союзу 2017 и 2010 гг. Проведен анализ динамики и выявлены основные тенденции инноваций в составных показателях. Оценка и рекомендации по повышению уровня инноваций были сформированы для проанализированных экономик.Мета статті — представити стан інноваційності для Польщі як помірного новатора і України як скромного новатора. Сутність і роль інновацій спостерігалась у сучасній світовій економіці. Оцінка даних була надана протягом останніх семи років, це означає період з 2010-го до 2017 року. Інновації польських та українських економік були проаналізовані на основі 27 конкретних показників із використанням методу порівняльного аналізу. Усі індикатори було проаналізовано для України і Польщі в порівняні до досягнень щодо Європейського Союзу 2017 і 2010 років. Для проведення оцінки було використано метадані, представлені в Інноваційній індикаційній панелі 2018 (регулярний документ, підготовлений на вимогу Генерального директорату з питань підприємництва та промисловості Європейської комісії). Проведено аналіз динаміки і виявлено основні тенденції інновації у складових показниках. Попри те, що ЄС є очевидним лідером, Польща в деяких показниках (інноваційно сприятливе середовище, вплив на зайнятість і реальні інвестиції) наближалася до результатів діяльності ЄС. Україна є найкращою за Індексу людських ресурсів, але має найгірший індекс інтелектуальної власності. Найбільше піднесення було в ЄС в інноваційному середовищі. Оцінка та рекомендації щодо підвищення інновацій були сформовані для аналізованих економік. У результаті були виявлені причини суттєвої різниці між Україною і Польщею. Україна перебуває у групі «Скромні новатори» і має найгірший показник. На відміну від України, Польща є однією з «Поміркованих новаторів», яка майже удвічі перевершує український показник. Як результат, обґрунтовано, що комплексний підхід до використання інновацій як рушійної сили для економіки повинен включати: підвищення рівня та ефективності освіти у школах та університетах; дослідження і розроблення сучасних технологій; збільшення умов ведення господарської діяльності, адекватне будівництво капіталу для інновацій, а також регулярне збільшення витрат на НДДКР, перейти до стратегії створення власних знань, створення конкурентної переваги на основі останніх інноваційних досягнень через запуск оригінальних рішень і «свіжих» знань на світовому ринку

Non-standard Hubbard models in optical lattices: a review

Originally, the Hubbard model has been derived for describing the behaviour of strongly-correlated electrons in solids. However, since over a decade now, variations of it are also routinely being implemented with ultracold atoms in optical lattices. We review some of the rich literature on this subject, with a focus on more recent non-standard forms of the Hubbard model. After an introduction to standard (fermionic and bosonic) Hubbard models, we discuss briefly common models for mixtures, as well as the so called extended Bose-Hubbard models, that include interactions between neighboring sites, next-neighboring sites, and so on. The main part of the review discusses the importance of additional terms appearing when refining the tight-binding approximation on the original physical Hamiltonian. Even when restricting the models to the lowest Bloch band is justified, the standard approach neglects the density-induced tunneling (which has the same origin as the usual on-site interaction). The importance of these contributions is discussed for both contact and dipolar interactions. For sufficiently strong interactions, also the effects related to higher Bloch bands become important even for deep optical lattices. Different approaches that aim at incorporating these effects, mainly via dressing the basis Wannier functions with interactions, leading to effective, density-dependent Hubbard-type models, are reviewed. We discuss also examples of Hubbard-like models that explicitly involve higher $p$-orbitals, as well as models that couple dynamically spin and orbital degrees of freedom. Finally, we review mean-field nonlinear-Schr\"odinger models of the Salerno type that share with the non-standard Hubbard models the nonlinear coupling between the adjacent sites. In that part, discrete solitons are the main subject of the consideration. We conclude by listing some future open problems.Comment: expanded version 47pp, accepted in Rep. Prog. Phy

Adventures of a tidally induced bar

Using N-body simulations, we study the properties of a bar induced in a discy dwarf galaxy as a result of tidal interaction with the Milky Way. The bar forms at the first pericentre passage and survives until the end of the evolution at 10 Gyr. Fourier decomposition of the bar reveals that only even modes are significant and preserve a hierarchy so that the bar mode is always the strongest. They show a characteristic profile with a maximum, similar to simulated bars forming in isolated galaxies and observed bars in real galaxies. We adopt the maximum of the bar mode as a measure of the bar strength and we estimate the bar length by comparing the density profiles along the bar and perpendicular to it. The bar strength and the bar length decrease with time, mainly at pericentres, as a result of tidal torques acting at those times and not to secular evolution. The pattern speed of the bar varies significantly on a time-scale of 1 Gyr and is controlled by the orientation of the tidal torque from the Milky Way. The bar is never tidally locked, but we discover a hint of a 5/2 orbital resonance between the third and fourth pericentre passage. The speed of the bar decreases in the long run so that the bar changes from initially rather fast to slow in the later stages. The boxy/peanut shape is present for some time and its occurrence is preceded by a short period of buckling instability

Mimics of Small Ribozymes Utilizing a Supramolecular Scaffold

For elucidating the mechanism of the general acid/base catalysis of the hydrolysis of RNA phosphodiester bonds, a number of cleaving agents having two cyclen moieties tethered to a 1,3,5-triazine core have been prepared and their ability to bind and cleave UpU studied over a wide pH range. Around neutral pH, the cleaving agents form a highly stable ternary complex with UpU and ZnII through coordination of the uracil N3 and the cyclen nitrogen atoms to the ZnII ions. Under conditions where the triazine core exists in the deprotonated neutral form, hydrolysis of UpU, but not of ApA, is accelerated by approximately two orders of magnitude in the presence of the cleaving agents, suggesting general base rather than metal ion catalysis. The probable mechanism of the observed catalysis and implications to understanding the general acid/base-catalyzed phosphodiester hydrolysis by ribozymes are discussed