Bone-specific master transcription factor Runx2 regulates signaling and metabolism related programs in osteoprogenitors

Aim. Runx2 (AML3) transcription factor is the key regulator of osteoblastic lineage progression and is indispensable for the formation of mineral bones. Runx2 expression increases during differentiation of osteoblasts to induce osteoblast-specific genes necessary for the production and deposition of bone mineral matrix. However, Runx2 is also expressed at a lower level in early osteoprogenitors, where its function is less understood. Here we study how Runx2 determines the early stages of osteoblastic commitment using the model system of Runx2 re-introduction in mouse calvaria cells with Runx2 null background. Method. Affymetrix analysis, Western blot analysis and quantitative real-time reverse transcriptase PCR (qRT-PCR) analysis were employed. Results. Gene expression profiling by Affymetrix microarrays revealed that along with the induction of extracellular matrix and bone mineral deposition related phenotypic markers, Runx2 regulates several cell programs related to signaling and metabolism in the early osteoprogenitors. Particularly, Runx2 regulates transcription of genes involved in G-protein coupled signaling network, FGF and BMP/TGF beta signaling pathways and in biogenesis and metabolism pathways of steroid hormones. Conclusion. The data indicate that the lineage specific program, regulated by the master regulatory transcription factor, includes the regulation of cellular signaling and metabolism which may allow the committed cell to react and behave differently in the same microenvironment.Транскрипційний фактор Runx2 (AML3) є важливим регулятором диференціації остеобластів, необхідним для формування кісток. Експресія гена Runx2 зростає в процесі диференціації остеобластів і призводить до активації остеобласт-специфічних генів, відповідальних за продукування мінерального матриксу. Мета роботи полягала у визначенні функції гена Runx2 у попередниках остеобластів, де він експресується на досить низькому рівні. Методи. Ми дослідили функцію гена Runx2 на ранніх стадіях розвитку остеобластів за допомогою модельної системи Runx2-нокаутних клітин скальпів мишей, яким вводили ген Runx2. Результати. При дослідженні експресії геному за допомогою чипів Affymetrix виявлено, що разом із індукцією фенотипових маркерів відкладання зовнішньоклітинного мінерального матриксу ген Runx2 регулює декілька генетичних програм, пов’язаних із сигналінгом і метаболізмом попередників остеобластів. Зокрема, Runx2 регулює гени сигнальної мережі, зчепленої з G-білками, сигнальні шляхи FGF, BMP/TGF, а також ферментативні системи біосинтезу і метаболізму стероїдних гормонів. Висновки. Отримані дані вказують на те, що частина програми спеціалізації, яку виконує ключовий транскрипційний фактор, складається з програмування сигнальних шляхів та метаболізму клітини, дозволяючи ранньоспеціалізованій клітині реагувати та функціонувати певним чином у мікросередовищі.Транскрипционный фактор Runx2 (AML3) является ключевым регулятором дифференциации остеобластов, необходимым для формирования костей. Экспресия гена Runx2 повышается в процессе дифференциации остеобластов, где он активирует остеобласт-специфические гены, необходимые для продукции минерального матрикса. Цель работы состояла в определении функции гена Runx2 в ранних предшественниках остеобластов, где он экспрессируется на достаточно низком уровне. Методы. Мы исследовали, как Runx2 функционирует на ранних стадиях специализации остеобластов с помощью модельной системы внедрения Runx2 в Runx2-нокаутные клетки скальпа мыши. Результаты. При изучении экспресии генома с помощью чипов Affymetrix обнаружено, что вместе с индукцией фенотипичных маркеров, отвечающих за продукцию внеклеточного матрикса, Runx2 регулирует несколько генетических программ, связанных с сигналингом и метаболизмом остеобластов. В частности, Runx2 регулирует гены сигнальной сети, сцепленной с G-белками, сигнальных путей FGF, BMP/TGF, а также системы биосинтеза и метаболизма стероидных гормонов. Выводы. Полученные данные указывают на то, что программа специализации, выполняемая ключевым транскрипционным фактором, включает программирование сигнальных путей и метаболизма клетки, позволяя раннедифференцированной клетке вести себя определенным образом в идентичной микросреде

Radar sounding of disperse streams

Atmospheric pollution by solid particles is a serious risk factor for human health. Moreover, it influences on climate change and can cause serious economical damage. More than 25% of the total air pollution comprise industrial emissions generated by fuel-burning power plants, metallurgical, and cement works. Therefore, particulate emission monitoring is an actual problem. The present dissertation is devoted to the development of remote sensing methods for estimating parameters of disperse streams (streams of solid particles which usually form particulate fraction of industrial emissions) utilizing radar technology. In order to estimate disperse stream parameters, such as mass loading, particle concentration, and particle size, theoretical methods of electromagnetic wave scattering by a spherical dielectric particle have been used; namely the approximate method of Rayleigh scattering, which is valid for particles that are much smaller than the operating wavelength of the radar, and the rigorous method – Mie theory, which allows calculating the radar cross-section (RCS) of particles in the whole range of wavelengths. Two methods of radar sounding are considered in the work: mono-frequency and double-frequency method. The mono-frequency method enables to estimate the mass loading and particle concentration, however, the method requires information about particle size and its distribution law. Applying an additional radar with a different operating frequency enables to use a concept of differential RCS which unambiguously depends on particle size for several special cases. This allows the double-frequency method to estimate the size of particles along with the mass loading and the particle concentration. For the experimental validation of the proposed measuring concepts, the mono-frequency and double-frequency radar-sensors with a bistatic antenna system have been developed and designed for operating in an air duct. Furthermore, the prototype of the mono-frequency radar with a quasioptical antenna system, which permits the transmitter and the receiver to operate with one common antenna in CW mode, has been constructed as well. Digital methods of radar signal processing, such as spectral and correlation analysis, as well as methods of statistical data processing have been utilized for the signals received by both systems. The conducted measurement results have shown that the mono-frequency method is only applicable in case of the fulfillment of the Rayleigh scattering conditions. The double-frequency method, which applies the rigorous Mie theory for estimating the RCS of particles, has shown a good reproducibility of the measurement results over a wide range of particle concentrations. The experimental study performed for the double-frequency method confirms its validity and efficiency for remote sensing of disperse streams with preliminary unknown particle size distribution law. The results shows that the developed methods of remote sensing of the disperse stream parameters by a radar can find their applications in industrial emission monitoring along with well-known optical and contact methods

The magnetic properties of electrical pulses delivered by deep-brain stimulation systems

The aim of this article is to analyze the magnetic field properties for both the monopolar and bipolar electrode configurations of deep-brain stimulation electrodes using 3-D magnetic field measurements and to investigate if the magnetic measurements enable a localization of the electrode as a proof of concept. Therefore, a simplified head phantom with an integrated deep-brain stimulation electrode was created to measure the magnetic flux densities in all the three dimensions with a fluxgate magnetometer over a sensor trajectory of measuring points inside the magnetically shielded chamber. The magnitude of the magnetic flux density for monopolar stimulation and bipolar stimulation is in the nT and pT ranges for the frequency 160 Hz, depending on the stimulation amplitude and on the distance between the sensor and the electrode. The field distributions show a linear decline in the magnetic field for the monopolar and a quadratic decline for the bipolar stimulation. We were able to reconstruct the magnetic field using multiple recording sites. As the magnetic field of deep-brain stimulation can be measured and its field strength can be reconstructed, it is feasible to estimate the strength of the field within the limits of programmable stimulation parameters and distance between the sensor and the electrode. The presented results are intended as preliminary work for the further development of electrode localization methods using magnetic measurements. As an example of the feasibility of electrode localization, this article presents a bipolar measurement that creates a more focused spatial field distribution and results in an accurate localization

Models and approaches to attack surface analysis for fuzz testing of the Linux kernel

The purpose of the study was to analyze possible methods for determining the attack surface in relation to solving the problem of fuzzing testing the kernel of operating systems of the Linux family and selecting the most suitable one. To evaluate and compare various models and practical approaches to attack surface analysis, as well as assess the possibility of combining them, theoretical research methods such as analysis, comparison, and deduction were used. Existing models and approaches to analyzing the attack surface of the Linux kernel are assessed and compared. A solution is proposed for the practical determination of the attack surface for effective testing of the kernel using the fuzzing method, which combines the studied approaches. The results of the study can be used to practically construct an attack surface, which will allow us to more accurately determine the goals of fuzz testing of the Linux kernel

Observation of time quasicrystal and its transition to superfluid time crystal

We report experimental realization of a quantum time quasicrystal, and its transformation to a quantum time crystal. We study Bose-Einstein condensation of magnons, associated with coherent spin precession, created in a flexible trap in superfluid $^3$He-B. Under a periodic drive with an oscillating magnetic field, the coherent spin precession is stabilized at a frequency smaller than that of the drive, demonstrating spontaneous breaking of discrete time translation symmetry. The induced precession frequency is incommensurate with the drive, and hence the obtained state is a time quasicrystal. When the drive is turned off, the self-sustained coherent precession lives a macroscopically-long time, now representing a time crystal with broken symmetry with respect to continuous time translations. Additionally, the magnon condensate manifests spin superfluidity, justifying calling the obtained state a time supersolid or a time super-crystal

Distribution of Larvae and Pupae of Blackflies (Diptera, Simuliidae) is Dependency upon Speed of Stream

У межах Волинського Полісся преімагінальні фази мошок населяють водойми зі швидкістю течії від 0,20 м/с. Залежно від швидкості течії при якій розвиваються личинки та лялечки, виділено три групи. Установлено, що оптимальною для розвитку преімагінальних фаз Simuliidae є швидкість течії 0,60–0,79 м/с. Within the limits of Volyn Polissya the immature stages of blackflies are inhabited by reservoirs at a speed of stream from a 0,20 meter/second. Depending on speed of stream at which larvae and pupae develop 3 groups are selected. It is set that optimum for development of immature stages of Simuliidae is speed of stream 0,60–0,79 meter/second.Роботу виконано на кафедрі зоології ВНУ ім. Лесі Українк

Exchange biased delta-E effect enables the detection of low frequency pT magnetic fields with simultaneous localization

Delta-E effect sensors are based on magnetoelectric resonators that detune in a magnetic field due to the delta-E effect of the magnetostrictive material. In recent years, such sensors have shown the potential to detect small amplitude and low-frequency magnetic fields. Yet, they all require external magnetic bias fields for optimal operation, which is highly detrimental to their application. Here, we solve this problem by combining the delta-E effect with exchange biased multilayers and operate the resonator in a low-loss torsion mode. It is comprehensively analyzed experimentally and theoretically using various kinds of models. Due to the exchange bias, no external magnetic bias fields are required, but still low detection limits down to [Formula: see text] at 25 Hz are achieved. The potential of this concept is demonstrated with a new operating scheme that permits simultaneous measurement and localization, which is especially desirable for typical biomedical inverse solution problems. The sensor is localized with a minimum spatial resolution of 1 cm while measuring a low-frequency magnetic test signal that can be well reconstructed. Overall, we demonstrate that this class of magnetic field sensors is a significant step towards first biomedical applications and compact large number sensor arrays