Requirements for identity management in next generation networks

Identity management will become crucial to the success of Next Generation Networks (NGN). However, until now very little research has been done in this fieid. This paper presents the requirements for identity management in NGN which are currently being investigated by our research group. Our analysis is based on the characteristics and requirements of NGN architectures, services, network operators, end users, identity management requirements for web services, recent standardization efforts by various bodies, etc

Modelling of spin decoherence in a Si hole qubit perturbed by a single charge fluctuator

Spin qubits in semiconductor quantum dots are one of the promizing devices to realize a quantum processor. A better knowledge of the noise sources affecting the coherence of such a qubit is therefore of prime importance. In this work, we study the effect of telegraphic noise induced by the fluctuation of a single electric charge. We simulate as realistically as possible a hole spin qubit in a quantum dot defined electrostatically by a set of gates along a silicon nanowire channel. Calculations combining Poisson and time-dependent Schr\"odinger equations allow to simulate the relaxation and the dephasing of the hole spin as a function of time for a classical random telegraph signal. We show that dephasing time $T_2$ is well given by a two-level model in a wide range of frequency. Remarkably, in the most realistic configuration of a low frequency fluctuator, the system has a non-Gaussian behavior in which the phase coherence is lost as soon as the fluctuator has changed state. The Gaussian description becomes valid only beyond a threshold frequency $\omega_{th}$, when the two-level system reacts to the statistical distribution of the fluctuator states. We show that the dephasing time $T_{2}(\omega_{th})$ at this threshold frequency can be considerably increased by playing on the orientation of the magnetic field and the gate potentials, by running the qubit along "sweet" lines. However, $T_{2}(\omega_{th})$ remains bounded due to dephasing induced by the non-diagonal terms of the stochastic perturbation Hamiltonian. Our simulations reveal that the spin relaxation cannot be described cleanly in the two-level model because the coupling to higher energy hole levels impacts very strongly the spin decoherence. This result suggests that multi-level simulations including the coupling to phonons should be necessary to describe the relaxation phenomenon in this type of qubit

Theoretical and experimental investigation of a Solar Free-Piston Stirling Engine (FPSE) using a flexible bellow for water pumping/power generation

Fossil fuels are the primary energy source globally and currently represent more than 80% of the overall energy consumption. Fossil fuels such as natural gas, oil and coal remain the principal fuels for supply and off-grid power generation in remote areas. Concerns over the negative environmental impact of greenhouse gases emission have shifted toward deploying and developing renewable and low carbon energy technologies. In the last decades, many sustainable and clean energy alternatives have been exploited to make energy and power generation clean and affordable to mitigate the negative impact of fossil fuels on the environment. The Stirling engine is considered one of the most promising solutions of sustainable power technologies to generate electricity from external heat sources. This research develops the computer model of a free-piston Stirling engine (FPSE) prototype operated by a solar simulator for small-scale power generation. The mathematical model was based on solving the working fluid's mass, energy and momentum conservation equations in different engine components. The engine's performance was evaluated based on the other three models: Schmidt, Adiabatic and Simple analysis. It is found that Simple analysis gave the most accurate result because the model considers the heat losses of the Stirling cycle. This research also investigated a novel design of a solar Free-piston Stirling engine for power generation and water pumping, which can be used in remote world regions. The design incorporates flexible bellows or diaphragm working as a power piston and two pre-compressed springs to support the displacer. This mechanical arrangement of the moving components in the engine reduces mechanical friction and air leakage. The experimentally testable FPSE was carried out, including a linear electric generator to develop and validate the theoretical simulation model. It was demonstrated the engine could operate successfully at an input heat temperature of 300C°, at 1 bar pressure and a frequency of 10 Hz. Moreover, a novel design is added to the engine to convert the linear motion to rotary motion. Overall, the engine's measured power and efficiency are low, and more tests of increasing the pressure of the engine for more than 1 bar are required to obtain better performance

The image of the Crimean Tatars in Jewish chronicles of the Khmelnytsky period

Introduction. The purpose of the article is a detailed analysis of the assessments contained in the Jewish historical chronicles of the Khmelnytsky uprising period and related to the characteristics of the Crimean Tatars who took an active part in the uprising of B.M. Khmelnitsky. Based on these assessments, we can reconstruct the image of the Muslim Tatars that developed in the historical consciousness of the Jewish late medieval society under the influence of the experienced catastrophe. Methods. Since the peculiarity of this study is the exceptional attention to the text of the source, methods based on text analysis and methods based on contextual analysis of speech and semantic constructions used by Jewish publicists and comparing them with the facts of biographies and historical events that could possibly affect the texts of chronicles were widely used. To solve the tasks set in the work, such concrete historical methods as historical-comparative and historicaltypological were also used. Results. On the basis of the work done, it can be concluded that for Jewish authors – creators of historical chronicles of the period of the «Khmelnichiny», the Muslim Tatars act, though evil, but much less than the evil that the Orthodox Ukrainians carried to the Jewish population. In the image of the Crimean Tatars, to some extent, one can even find positive assessments showing pity and concern for those Jews who surrendered to them. The same cannot be said about the image of the Orthodox population that has developed in Jewish chronicles under the impression of the horrors of the People's Liberation war in Ukraine in the middle of the XVII century. Conclusion. The Crimean Tatars who took part in the uprising of Bohdan Khmelnytsky were perceived by Jews as enemies, but with a certain shade of respect, which we absolutely will not find in the current image of the Orthodox population of Ukraine

Development of magnetically active scaffolds for bone regeneration

This work reports on the synthesis, with the thermally induced phase separation (TIPS) technique, of poly (L-lactide) (PLLA) scaffolds containing Fe-doped hydroxyapatite (FeHA) particles for bone regeneration. Magnetization curves and X-ray diffraction indicate two magnetic particle phases: FeHA and magnetite Fe3O4. Magnetic nanoparticles (MNPs) are approximately 30 ± 5 nm in width and 125 ± 25 nm in length, and show typical ferromagnetic properties, including coercivity and rapid saturation magnetization. Scanning electron microscopy (SEM) images of the magnetic scaffolds reveal their complex morphology changes with MNP concentration. Similarly, at compositions of approximately 20% MNPs, the phase separation changes, passing from solid–liquid to liquid–liquid as revealed by the hill-like structures, with low peaks that give the walls in the SEM images a surface pattern of micro-ruggedness typical of nucleation mechanisms and growth. In vitro degradation experiments, carried out for more than 28 weeks, demonstrated that the MNPs delay the scaffold degradation process. Cytotoxicity is appreciated for FeHA content above 20%.This work was supported by the University of The Basque Center and the Portuguese Foundation for Science and Technology (FCT) under the framework Strategic Funding UID/FIS/04650/ UID/BIA/04050/2013, and UID/BIO/04469. S.R. would like to the FCT for the SFRH/BD/111478/2015 grant. The authors acknowledge funding by the Spanish Ministry of Economy and Competitiveness (MINECO) under the project MAT2016-76039-C4-3-R (AEI/FEDER, UE)info:eu-repo/semantics/publishedVersio

Theoretical and experimental investigation of a Solar Free-Piston Stirling Engine (FPSE) using a flexible bellow for water pumping/power generation

Fossil fuels are the primary energy source globally and currently represent more than 80% of the overall energy consumption. Fossil fuels such as natural gas, oil and coal remain the principal fuels for supply and off-grid power generation in remote areas. Concerns over the negative environmental impact of greenhouse gases emission have shifted toward deploying and developing renewable and low carbon energy technologies. In the last decades, many sustainable and clean energy alternatives have been exploited to make energy and power generation clean and affordable to mitigate the negative impact of fossil fuels on the environment. The Stirling engine is considered one of the most promising solutions of sustainable power technologies to generate electricity from external heat sources. This research develops the computer model of a free-piston Stirling engine (FPSE) prototype operated by a solar simulator for small-scale power generation. The mathematical model was based on solving the working fluid's mass, energy and momentum conservation equations in different engine components. The engine's performance was evaluated based on the other three models: Schmidt, Adiabatic and Simple analysis. It is found that Simple analysis gave the most accurate result because the model considers the heat losses of the Stirling cycle. This research also investigated a novel design of a solar Free-piston Stirling engine for power generation and water pumping, which can be used in remote world regions. The design incorporates flexible bellows or diaphragm working as a power piston and two pre-compressed springs to support the displacer. This mechanical arrangement of the moving components in the engine reduces mechanical friction and air leakage. The experimentally testable FPSE was carried out, including a linear electric generator to develop and validate the theoretical simulation model. It was demonstrated the engine could operate successfully at an input heat temperature of 300C°, at 1 bar pressure and a frequency of 10 Hz. Moreover, a novel design is added to the engine to convert the linear motion to rotary motion. Overall, the engine's measured power and efficiency are low, and more tests of increasing the pressure of the engine for more than 1 bar are required to obtain better performance

Criteria for Selecting Volleyball Team Captain on the Signs of their Leader Behavior

Objective of the study was to experimentally substantiate the dependence of the cohesion of sports teams, the success of their performances, as well as the development of the personality of young volleyball players, on the degree of severity of the captains of these teams' propensity for various leadership options

Leucine-zipper motif is responsible for self-association of translation elongation factor 1Bβ

Translation elongation factor 1Bβ (eEF1Bβ) is a metazoan-specific protein catalyzing the guanine nucleotide exchange on translation elongation factor 1A (eEF1A). eEF1Bβ was reported to form oligomers. Aim. To define the structural region of human eEF1Bβ that mediates its self-association. In addition, the various truncated forms of this protein were tested in the guanine nucleotide exchange assay with two isoforms of mammalian eEF1A. Methods. The truncated forms of eEF1Bβ were generated by PCR, cloned, expressed in Escherichia coli and purified to homogeneity. Their apparent molecular masses were determined by analytical gel filtration and their guanine nucleotide exchange activities were assessed by filter binding assay. Results. Complete deletion of the N-terminal domain of eEF1Bβ does not affect its oligomerization propensity while deletion of the leucine-zipper motif drastically decreases the apparent molecular mass of the truncated form compared to the full-length protein. Also, the leucine-zipper motif of eEF1Bβ fused to glutathione S-transferase causes oligomerization of the chimeric protein. It was demonstrated that all N-terminally truncated forms of eEF1Bβ displayed similar catalytic activity to that of the full-length protein. Weak inhibitory effect on the catalytic activity was observed only for the truncated form with partially deleted central acidic region. Conclusions. The leucine-zipper motif facilitates oligomerization of recombinant eEF1Bβ. Stepwise deletion of the eEF1Bβ N-terminal domain does not significantly affect the guanine nucleotide exchange activity of the truncated proteins.Фактор елонгації трансляції 1Bβ(eEF1Bβ) – це білок, наявний лише у багатоклітинних організмів. Він каталізує обмін гуанінових нуклеотидів на факторі елонгації трансляції 1A (eEF1A). Відомо, що eEF1Bβ утворює олігомери. Мета. Визначити структурний домен eEF1Bβ людини, який опосередковує його олігомеризацію. Для встановлення ймовірного впливу N-кінцевої ділянки eEF1Bβ на каталітичну активність цього білка, було перевірено здатність різних вкорочених форм eEF1Bβ каталізувати обмін гуанінових нуклеотидів на обох ізоформах eEF1A ссавців. Методи. Фрагменти кДНК, які кодують вкорочені форми, eEF1Bβ отримували шляхом ПЛР ампліфікації, потім клонували у відповідні вектори, які експресували в клітинах Escherichia coli. Рекомбінантні білки очищали і їхні молекулярні маси визначали аналітичною гель-фільтрацією. Активність вкорочених форм eEF1Bβ перевіряли в реакції обміну гуанінових нуклеотидів. Результати. Видалення N-кінцевого домену eEF1Bβ не вплинуло на його олігомерізацію, в той час як видалення мотиву типу «лейцинова застібка» значно зменшувало молекулярну масу вкороченої форми білка в порівнянні з повнорозмірною. Також, амінокислотний мотив eEF1Bβ типу «лейцинова застібка» злитий з глутатіон S-трансферазою спричиняв олігомерізацію цього химерного білка. Показано, що всі вкорочені з N-кінця форми eEF1Bβ проявляли каталітичну активність, подібну до повнорозмірного білка. Інгібіторний ефект на каталітичну активність спостерігався лише для вкороченої форми білка, в якої була відсутня частина центрального негативно зарядженого регіону. Висновки. Амінокислотний мотив типу «лейцинова застібка» сприяє олігомерізації рекомбінантного eEF1Bβ. Поступове вкорочення N-кінцевого домену не має значного впливу на каталітичну активність eEF1Bβ.Фактор элонгации трансляции 1Bβ (eEF1Bβ) – белок, присутствующий только в многоклеточных организмах. Он катализирует обмен гуаниновых нуклеотидов на факторе элонгации трансляции 1A (eEF1A). Известно, что eEF1Bβ образует олигомеры. Цель. Определить структурный домен eEF1Bβ человека, который вызывает его олигомеризацию. Для исследования возможного влияния N-концевого участка eEF1Bβ на каталитическую активность этого белка, мы проверили способность различных укороченных форм eEF1Bβ катализировать обмен гуаниновых нуклеотидов на обеих изоформах eEF1A млекопитающих. Методы. Фрагменты кДНК, кодирующие укороченные формы eEF1Bβ, получали при помощи ПЦР амплификации, потом клонировали в соответствующие вектора, которые экспрессировали в клетках Escherichia coli. Рекомбинантные белки очищали и их молекулярные массы определяли аналитической гель-фильтрацией. Активность укороченных форм eEF1Bβ проверяли в реакции обмена гуаниновых нуклеотидов. Результаты. Полное удаление N-концевого домена не влияло на олигомеризацию eEF1Bβ, однако удаление мотива типа «лейцинова застёжка» значительно уменьшало молекулярную массу укороченной формы белка по сравнению с полноразмерной. Также, присоединение аминокислотного мотива eEF1Bβ типа «лейциновая застёжка» к глутатион S-трансферазе вызвало олигомеризацию этого химерного белка. Показано, что все укороченные с N-конца формы eEF1Bβ проявляли такую же каталитическую активность, как и полноразмерный белок. Слабый ингибирующий эффект на каталитическую активность наблюдался лишь для укороченной формы белка с отсутствующей частью центрального негативно заряженного региона. Выводы. Аминокислотный мотив типа «лейциновая застёжка» способствует олигомеризации рекомбинантного eEF1Bβ. Постепенное укорочение N-концевого домена не оказывает значительного влияния на каталитическую активность eEF1Bβ

An assessment of the methodological quality of published network meta-analyses: a systematic review

Objective To assess the methodological quality of published network meta-analysis. Design Systematic review. Methods We searched the medical literature for network meta-analyses of pharmaceuticals. We assessed general study characteristics, study transparency and reproducibility, methodological approach, and reporting of findings. We compared studies published in journals with lower impact factors with those published in journals with higher impact factors, studies published prior to January 1st, 2013 with those published after that date, and studies supported financially by industry with those supported by non-profit institutions or that received no support. Results The systematic literature search identified 854 citations. Three hundred and eighteen studies met our inclusion criteria. The number of network meta-analyses has grown rapidly, with 48% of studies published since January 2013. The majority of network meta-analyses were supported by a non-profit institution or received no support (68%). We found considerable inconsistencies among reviewed studies. Eighty percent reported search terms, 61% a network diagram, 65% sufficient data to replicate the analysis, and 90% the characteristics of included trials. Seventy percent performed a risk of bias assessment of included trials, 40% an assessment of model fit, and 56% a sensitivity analysis. Among studies with a closed loop, 69% examined the consistency of direct and indirect evidence. Sixty-four percent of studies presented the full matrix of head-to-head treatment comparisons. For Bayesian studies, 41% reported the probability that each treatment was best, 31% reported treatment ranking, and 16% included the model code or referenced publicly-available code. Network meta-analyses published in higher impact factors journals and those that did not receive industry support performed better across the assessment criteria. We found few differences between older and newer studies. Conclusions There is substantial variation in the network meta-analysis literature. Consensus among guidelines is needed improve the methodological quality, transparency, and consistency of study conduct and reporting