Effect of poling in Polymers Containing Azobenzene Push–Pull Chromophores on nonlinear optic of second and third order

International audienc

Influence of roughness on ZDDP tribofilm formation in boundary lubricated fretting

Influence of initial surface topography on tribofilm formation in ZDDP lubricated contact was analysed. A small displacement fretting tests with sinusoidal motion were carried out in classical sphere/plane configuration. A range of surfaces with different initial roughness were prepared by milling and grinding processes. Tests were carried out using variable displacement method where amplitude of imposed displacement was gradually increased after every 1000 cycles from 2 to 30 µm. The surfaces after tribological tests were measured by interferometric profiler. Main findings confirm that initial roughness has a significant influence on antiwear tribofilm formation in boundary lubricated contact. Tribofilm form faster and require less energy to activate in case of rough surface obtained by milling process than in case of smooth grinded surface. However, in contact lubricated by ZDDP additive a significant transfer of material occurred from plane to sphere specimen

Gauge Formalism for General Relativity and Fermionic Matter

A new formalism for spinors on curved spaces is developed in the framework of variational calculus on fibre bundles. The theory has the same structure of a gauge theory and describes the interaction between the gravitational field and spinors. An appropriate gauge structure is also given to General Relativity, replacing the metric field with spin frames. Finally, conserved quantities and superpotentials are calculated under a general covariant form.Comment: 18 pages, Plain TEX, revision, explicit expression for superpotential has been adde

Pension assets as an investment in economic growth: The case of post-socialist countries and Ukraine

Pension assets as an investment in economic growth: The case of post-socialist countries and Ukraine / O. Kolodiziev, H. Telnova, I. Krupka, M. Kulchytskyy, I. S. Sybirtseva // Investment Management and Financial Innovations. – 2021. – № 18 (3). – Р. 166-174. – DOI: https://doi.org/10.21511/imfi.18(3).2021.15Стаття має на меті встановити вплив пенсійних активів на економічне зростання на прикладі постсоціалістичних країн (Угорщина, Словаччина, Словенія, Польща, Чехія). Використання методів кореляційно-регресійного аналізу дозволяє визначити тип залежності (лінійна, експоненційна, поступова та логарифмічна) показників економічного зростання країн від пенсійних активів та закономірностей їх інвестування (депозити, цінні папери державного та приватного секторів). Отримані показники економічного зростання постсоціалістичних країн, що вивчаються, демонструють сильну логарифмічну залежність від розміру пенсійних активів: валове накопичення основного капіталу залежить від зміни суми пенсійних активів на 76,44% і ВВП на 71,01%. На економічне зростання постсоціалістичних країн, що вивчаються, найбільш істотний вплив мають пенсійні активи, вкладені в депозити. Інвестування пенсійних накопичень у цінні папери державного та приватного секторів менш ефективне. Обґрунтовані положення визначають доцільність переходу від переважаючої розподільної пенсійної системи до накопичувальної пенсійної системи, що переважає для України. Така трансформація вимагає стабільної та ефективної побудови банківської системи країни, виробленої політики реформування пенсійної системи з урахуванням критеріїв внутрішньої демографічної, соціальної та фінансової ситуації.The paper aims to establish the impact of pension assets on economic growth using the example of postsocialist countries (Hungary, the Slovak Republic, Slovenia, Poland, and the Czech Republic). Te use of methods of correlation and regression analysis allows determining the type of dependence (linear, exponential, gradual, and logarithmic) of countries’ economic growth indicators on pension assets and patterns for their investment (deposits, securities of public and private sectors). Te obtained economic growth indicators of the studied post-socialist countries show a strong logarithmic dependence on the size of pension assets: Gross fxed capital formation depends on changes in the pension asset amount by 76.44% and GDP by 71.01%. Te economic growth of the studied post-socialist countries is most signifcantly influenced by pension assets invested in deposits. Investing pension savings in public and private sector securities is less effective. Te proved provisions determine the expediency of moving from the predominant pay-as-you-earn pension scheme to the predominant fully funded pension system for Ukraine. Such a transformation requires a stable and efcient construction of the country’s banking system, a developed policy for reforming the pension system while considering the criteria of the internal demographic, social, and fnancial situation.В статье ставится задача установить влияние пенсионных активов на экономический рост на примере постсоциалистических стран (Венгрия, Словакия, Словения, Польша, Чехия). Использование методов корреляционно-регрессионного анализа позволяет определить тип зависимости (линейная, экспоненциальная, постепенная и логарифмическая) показателей экономического роста стран от пенсионных активов и закономерностей их инвестирования (депозиты, ценные бумаги государственного и частного секторов). Полученные показатели экономического роста изучаемых постсоциалистических стран демонстрируют сильную логарифмическую зависимость от размера пенсионных активов: валовое накопление основного капитала зависит от изменения суммы пенсионных активов на 76,44% и ВВП на 71,01%. На экономический рост изучаемых постсоциалистических стран наиболее существенное влияние оказывают пенсионные активы, вложенные в депозиты. Инвестирование пенсионных накоплений в ценные бумаги государственного и частного секторов менее эффективно. Обоснованные положения определяют целесообразность перехода от преобладающей распределительной пенсионной системы к преобладающей для Украины накопительной пенсионной системе. Такая трансформация требует стабильного и эффективного построения банковской системы страны, выработанной политики реформирования пенсионной системы с учетом критериев внутренней демографической, социальной и финансовой ситуации

Quantifying the habitat and zoogeomorphic capabilities of spawning European barbel Barbus barbus, a lithophilous cyprinid

Suitable gravel availability is critical for the spawning success of lithophilous fishes, including redd builders. Redd construction during spawning can alter substrate characteristics, thereby influencing hydraulic conditions and sediment transport, highlighting the importance of spawning as a zoogeomorphic activity. Here, interactions between redd‐building fish and their spawning environment were investigated for European barbel Barbus barbus with a comparative approach across three English rivers: Teme (western), Great Ouse (eastern) and Idle (central). Sediment characteristics of spawning habitats were similar across the rivers, including subsurface fine sediment (<2 mm) content (≈20% dry weight), but elevated subsurface silt content and coarser surface sediments were found in the river Teme. Water velocities were similar at spawning sites despite differences in channel width and depth. Redds were characterized by a pit and tailspill, with no differences in surface grain‐size characteristics between these and the surrounding riverbed, but with topographic alteration (dimensions and tailspill amplitude) in line with those of salmonids. Estimates of the fraction of the bed that spawning barbel were capable of moving exceeded 97% in all rivers. Estimated reproductive potential varied significantly between the rivers Idle and Teme (3,098 to 9,715 eggs/m2), which was largely due to differences in barbel lengths affecting fecundity. Larger barbel, capable of producing and depositing more eggs, but in more spatially extensive redds, meaning fewer redds per given surface area of riverbed. Predictions of barbel egg mortality based on sand content were low across both rivers. The effects of silt on barbel egg and larvae development are unknown, but the levels detected here would significantly impact salmon egg mortality. Similarities in fish length to redd area and the size of moveable grains by spawning barbel and salmon suggest they have similar geomorphic effects on sediments, although fine sediment tolerance is highly divergent

Magnetic Properties in Non-centrosymmetric Superconductors with and without Antiferromagnetic Order

The paramagnetic properties in non-centrosymmetric superconductors with and without antiferromagnetic (AFM) order are investigated with focus on the heavy Fermion superconductors, CePt_3Si, CeRhSi_3 and CeIrSi_3. First, we investigate the spin susceptibility in the linear response regime and elucidate the role of AFM order. The spin susceptibility at T=0 is independent of the pairing symmetry and increases in the AFM state. Second, the non-linear response to the magnetic field are investigated on the basis of an effective model for CePt_3Si which may be also applicable to CeRhSi_3 and CeIrSi_3. The role of antisymmetric spin-orbit coupling (ASOC), helical superconductivity, anisotropic Fermi surfaces and AFM order are examined in the dominantly s-, p- and d-wave states. We emphasize the qualitatively important role of the mixing of superconducting (SC) order parameters in the p-wave state which enhances the spin susceptibility and suppresses paramagnetic depairing effect in a significant way. Therefore, the dominantly p-wave superconductivity admixed with the s-wave order parameter is consistent with the paramagnetic properties of CePt_3Si at ambient pressure. We propose some experiments which can elucidate the novel pairing states in CePt_3Si as well as CeRhSi_3 and CeIrSi_3.Comment: To appear in J. Phys. Soc. Jpn. (2007) No.1

Negative assimilation:how immigrants experience economic mobility in Japan

This paper examines the economic mobility of foreign migrants in Japan. In a country that is largely regarded as homogeneous and closed to outsiders, how and to what extent do immigrants achieve economic success? A survey conducted by the authors revealed that the conventional assimilationist perspective does not fully explain immigrants’ economic success in Japan. Migrants from the West experience what Chiswick and Miller (2011) refer to as “negative assimilation.” That is, their earnings decline over time in Japan. While negative assimilation was not clearly observed among immigrants from neighboring Asian countries, wages among them did not increase with the length of their stay in Japan. For both groups, the skills they brought from abroad were found to be largely accountable for their economic success, while locally specific human capital, such as education acquired in the host society, did not contribute to their earnings

Locally Non-centrosymmetric Superconductivity in Multilayer Systems

Although multilayer systems possess global inversion symmetry, some of the layers lack local inversion symmetry because no global inversion centers are present on such layers. Such locally non-centrosymmetric systems exhibit spatially modulated Rashba spin-orbit coupling. In this study, the superconductivity in multilayer models exhibiting inhomogeneous Rashba spin-orbit coupling is investigated. We study the electronic structure, superconducting gap, and spin susceptibility in the superconducting state with mixed parity order parameters. We show the enhancement of the spin susceptibility by Rashba spin-orbit coupling and interpret it on the basis of the crossover from a centrosymmetric superconductor to a non-centrosymmetric superconductor. It is also shown that the spin susceptibility is determined by the phase difference of the order parameter between layers and is nearly independent of the parity mixing of order parameters. An intuitive understanding is given on the basis of the analytic expression of superconducting order parameters in the band basis. The results indicate that not only a broken global inversion symmetry but also a broken local inversion symmetry leads to unique properties of superconductivity. We discuss the superconductivity in artificial superlattices involving CeCoIn5 and multilayer high-Tc cuprates.Comment: 11 pages, 13 figures, final version for publication in J. Phys. Soc. Jp

Tau-Mediated Nuclear Depletion and Cytoplasmic Accumulation of SFPQ in Alzheimer's and Pick's Disease

Tau dysfunction characterizes neurodegenerative diseases such as Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD). Here, we performed an unbiased SAGE (serial analysis of gene expression) of differentially expressed mRNAs in the amygdala of transgenic pR5 mice that express human tau carrying the P301L mutation previously identified in familial cases of FTLD. SAGE identified 29 deregulated transcripts including Sfpq that encodes a nuclear factor implicated in the splicing and regulation of gene expression. To assess the relevance for human disease we analyzed brains from AD, Pick's disease (PiD, a form of FTLD), and control cases. Strikingly, in AD and PiD, both dementias with a tau pathology, affected brain areas showed a virtually complete nuclear depletion of SFPQ in both neurons and astrocytes, along with cytoplasmic accumulation. Accordingly, neurons harboring either AD tangles or Pick bodies were also depleted of SFPQ. Immunoblot analysis of human entorhinal cortex samples revealed reduced SFPQ levels with advanced Braak stages suggesting that the SFPQ pathology may progress together with the tau pathology in AD. To determine a causal role for tau, we stably expressed both wild-type and P301L human tau in human SH-SY5Y neuroblastoma cells, an established cell culture model of tau pathology. The cells were differentiated by two independent methods, mitomycin C-mediated cell cycle arrest or neuronal differentiation with retinoic acid. Confocal microscopy revealed that SFPQ was confined to nuclei in non-transfected wild-type cells, whereas in wild-type and P301L tau over-expressing cells, irrespective of the differentiation method, it formed aggregates in the cytoplasm, suggesting that pathogenic tau drives SFPQ pathology in post-mitotic cells. Our findings add SFPQ to a growing list of transcription factors with an altered nucleo-cytoplasmic distribution under neurodegenerative conditions

Cytoplasmic Accumulation and Aggregation of TDP-43 upon Proteasome Inhibition in Cultured Neurons

Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are characterized by intraneuronal deposition of the nuclear TAR DNA-binding protein 43 (TDP-43) caused by unknown mechanisms. Here, we studied TDP-43 in primary neurons under different stress conditions and found that only proteasome inhibition by MG-132 or lactacystin could induce significant cytoplasmic accumulation of TDP-43, a histopathological hallmark in disease. This cytoplasmic accumulation was accompanied by phosphorylation, ubiquitination and aggregation of TDP-43, recapitulating major features of disease. Proteasome inhibition produced similar effects in both hippocampal and cortical neurons, as well as in immortalized motor neurons. To determine the contribution of TDP-43 to cell death, we reduced TDP-43 expression using small interfering RNA (siRNA), and found that reduced levels of TDP-43 dose-dependently rendered neurons more vulnerable to MG-132. Taken together, our data suggests a role for the proteasome in subcellular localization of TDP-43, and possibly in disease