Modulation of Circumstellar Extinction in a Young Binary System with a Low-Mass Companion in a Noncoplanar Orbit

The cyclic activity model of a young star with the low-mass secondary component (q = M2/M1 <= 0.1) accreting a matter from circumbinary disk is considered. It is assumed that the orbit is circular and the disk and orbital planes are non-coplanar. Sets of hydrodynamics models of such a system have been calculated by the SPH method and then the variations of the circumstellar extinction and phase light curves were determined. The calculations showed that depending on the model parameters and orientation of the system in regards to an observer the different in shape and amplitude light curves can be observed. An important property of the considered models is also the dependence of the mass accretion rate onto the components on the phase of the orbital period. The results of the calculation can be used for analysis of the cyclic activity of UX Ori stars and young stars with the long-lasting eclipses.Comment: 14 pages, 7 figure

APPLICATION FEATURES OF FUZZY CONTROLLERS ON EXAMPLE OF DC MOTOR SPEED CONTROL

A prerequisite for the use of intelligent control methods, including algorithms of fuzzy logic, is increasing complexity in all industries, especially when parameters of technical systems while in operation vary in wide range. The paper provides comparative analysis of the basic types of common fuzzy direct action controllers on the example of speed control system in the DC motor drive. Design features of these types of fuzzy controllers are shown. Their comparison with traditional PI controller is carried out through the use of simulation, including the conditions of uncertainty expressed in changing of equivalent moment of inertia of the motor shaft. As a result, the conclusion about the feasibility of fuzzy PID-type controller application is made. The features of fuzzy controllers outlined in the paper can be summarized to more complex motor drive systems and to other non-linear systems that require the maintenance of any parameter within a given range

Escherichia coli Strain – Super-Producer of Vibrio cholerae Hemolysin

Objective of this work was the cloning of Vibrio cholerae hlyA gene in a plasmid vector providing expression of foreign genes under the control of T5 promoter, and construction of E. coli strain – super-producer of Vibrio cholerae recombinant hemolysin. Materials and methods. V. cholerae о1 strain served as a DNA donor, pQE30 – as a vector plasmid. The gene was PCR-amplified, cloning was carried out by means of conventional methods, productivity of recombinants and localization of the required protein was determined based on the results of electrophoresis of cell lysates. Results and conclusions. A recombinant plasmid pHlyA, expressing the cloned hlyA gene of Vibrio cholerae El Tor under the control of T5 promoter after IPTG induction, has been constructed. Carrying this plasmid strain E. coli M15[pREP4]pHlyA is the super-producer of hemolysin: the content of the product in whole cell lysates is up to 13 %, and in inclusion bodies – up to 17 % of the total cell proteins. The product of the cloned gene, in spite of the absence of proteolytic processing and presence of the hexahistidine block (6His-tag) at its N-terminus, possesses hemolytic activity towards sheep erythrocytes. 6His-tag will provide for obtaining a purified preparation on specific sorbents with a view to create diagnosticums as well as to study the significance of hemolysin as a pathogenicity/persistence factor. The advantages of this producer are the high output of the required protein, inability of synthesis of any accessory biologically active substances, short-term period of biomass growing (4–6 h including induction) and possibility of culturing without sticking to the guidelines for work with the agents of particularly dangerous infections

Actinic reticuloid: case report

This article is about the case of actinic reticuloid — the rare dermatosis which clinical presentation is similar to atopic dermatitis, T-cell lymphoma. Good treatment effect was obtained by long cycles (2 cycles for 3 months) of hydroxychloroquine and sun protective therapy included sunscreens SPF 50, nicotinic acid, sun-safe clothes which blocked ultraviolet radiation without any glucocorticosteroid drugs and cytostatic treatment

The first result of the neutrino magnetic moment measurement in the GEMMA experiment

The first result of the neutrino magnetic moment measurement at the Kalininskaya Nuclear Power Plant (KNPP) with the GEMMA spectrometer is presented. An antineutrino-electron scattering is investigated. A high-purity germanium detector of 1.5 kg placed 13.9 m away from the 3 GW reactor core is used in the spectrometer. The antineutrino flux is $2.73\times 10^{13} \nu_e / cm^2 / s$. The differential method is used to extract the $\nu$-e electromagnetic scattering events. The scattered electron spectra taken in 6200 and 2064 hours for the reactor ON and OFF periods are compared. The upper limit for the neutrino magnetic moment $\mu_\nu < 5.8\times 10^{-11}$ Bohr magnetons at 90{%} CL is derived from the data processing.Comment: 9 pages, 10 figures, 2 table

Bimodal Brightness Oscillations in Models of Young Binary Systems

We consider a model for the cyclic activity of young binary stars that accrete matter from the remnants of a protostellar cloud. If the orbit of such a binary system is inclined at a small angle to the line of sight, then the streams of matter and the density waves excited in the circumbinary disk can screen the primary component of the binary from the observer. To study these phenomena by the SPH (smoothed particle hydrodynamics) method, we have computed grids of hydrodynamic models for binary systems based on which we have constructed the light curves as a function of the orbital phase.The main emphasis is on investigating the properties of the brightness oscillations. Therefore, the model parameters were varied within the following ranges: the component mass ratio q = M2 : M1 = 0.2 - 0.5 and the eccentricity e = 0 - 0.7. The parameter that defined the binary viscosity was also varied. We adopted optical grain characteristics typical of circumstellar dust. Our computations have shown that bimodal oscillations are excited in binaries with eccentric orbits, provided that the binary components do not differ too much in mass. In this case, the ratios of the periods and amplitudes of the bimodal oscillations and their shape depend strongly on the inclination of the binary plane and its orientation relative to the observer. Our analysis shows that the computed light curves can be used in interpreting the cyclic activity of UX Ori stars.Comment: 14 pages, 5 figures, 1 tabl

Recombinant Escherichia coli Strain with Enhanced Production of Vibrio cholerae Neuraminidase

Objective of this work was cloning of the Vibrio cholerae nanH gene as part of a plasmid vector, providing expression of foreign genes under the control of T5 promoter, and construction of a E. coli strain – producer of V. cholerae recombinant neuraminidase.Materials and methods. V. cholerae о1 strain served as a DNA donor, pQE30 – as a vector plasmid. The gene was PCR-amplifi ed, the cloning was carried out by means of conventional methods, performance of recombinants and localization of the required protein was determined based on the results of electrophoresis of cell lysates. Neuraminidase activity was identifi ed by fl uorescence in ultraviolet light after incubation with specifi c substrate (4-methylumbelliferyl-N-acetylneuraminic acid).Results and discussion. Recombinant plasmid pNanH, containing the cloned gene nanH V. cholerae, has been constructed. The gene is inserted into BamHI-PstI sites of the polylinker of pQE30. Expression of the cloned gene in the producer strain E. coli JM103pNanH occurs under the control of T5 promoter after isopropyl-1-thio-β-D-galactopyranoside (IPTG) induction. The strain shows neuraminidase activity. The recombinant NanH protein is accumulated in the producer’s cells in two forms. The fi rst form, with molecular mass (MM) of 89.5 kDa, is an unprocessed protein with the hexahistidine block (6His-tag) at its N-terminus, it is located in inclusion bodies. Its percentage is 5.6–6.6 % of the total cell proteins. The second one, with MM of 83 kDa, is found in the periplasmic space and corresponds to the mature NanH, its percentage being 3.4–3.8 %. The total percentage of both forms is 9–10 % of total cell proteins, which allows to consider the strain E. coli JM103pNanH to be a super-producer of the required protein. The strain may be used for purifi cation of NanH preparations for construction of specifi c diagnostic, therapeutic and pharmaceutical preparations as well as for investigation of the protein as a virulence/persistence factor of the pathogen

Прогнозирование эффективности терапии метотрексатом по базальной экспрессии гена АМР-активируемой протеинкиназы в крови больных ревматоидным артритом

Objective: to search for an association between basal expression of the AMP-activated protein kinase (adenosine monophosphate-activated protein kinase, AMPK) gene in the blood of patients with rheumatoid arthritis (RA) and disease activity, as well as joint destruction before and after 24 months of methotrexate (MT) therapy.Patients and methods. The study included 40 patients with RA who met the 1987 ACR classification criteria, with a disease duration of not more than 2 years, with a mean age of 47.5±15.5 years. All patients received 15 mg/week of MT. The number of swollen joints (SJC) out of 44, the number of tender joints (TSC) out of 53, the duration of morning stiffness (in minutes) and RA activity were assessed using the DAS28 index. The concentration of CRP and IgM rheumatoid factor (RF), antibodies to cyclic citrullinated peptide (ACCP) were assessed. To evaluate the radiological progression of RA, the Sharp method modified by van der Heijde was used. Gene expression in peripheral blood cells was determined by reverse transcriptase reaction and real-time polymerase chain reaction.Results and discussion. During MT therapy, there was a decrease in disease activity by DAS28 index, CRP level, duration of morning stiffness, SJC and TJC. After 2 years, there were no statistically significant changes in the number of erosions, while the number of joints with narrowing of the joint space increased by the end of the study (p=0.004). Treatment with MT resulted in a decrease in AMPK expression. At the same time, patients who achieved remission had the highest level of AMPK before therapy, as did seronegative patients compared to seropositive ones. Based on the ROC analysis, the threshold value of AMPK gene expression was determined, which makes it possible to predict a high probability of a positive effect of MT therapy.Conclusion. AMPK gene expression is associated with disease activity. Its high initial blood level in RA patients is associated with greater efficiency of MT and, possibly, plays a protective role. With an AMPK gene expression index greater than 3.83, the probability of a positive response to MT is high.Цель исследования – поиск ассоциации между базальной экспрессией гена АМР-активируемой протеинкиназы (adenosine monophosphate-activated protein kinase, АМРК) в крови больных ревматоидным артритом (РА) и активностью заболевания, а также деструкцией суставов до и после 24 мес терапии метотрексатом (МТ).Пациенты и методы. В исследование включено 40 пациентов с РА, удовлетворявших классификационным критериям АCR 1987 г., с длительностью заболевания не более 2 лет, средний возраст которых составил 47,5±15,5 года. Все пациенты получали МТ в дозе 15 мг/нед. Оценивали число припухших суставов (ЧПС) из 44, число болезненных суставов (ЧБС) из 53, продолжительность утренней скованности (в минутах) и активность РА с помощью индекса DAS28. Исследовали концентрацию СРБ и IgM ревматоидного фактора (РФ), антител к циклическому цитруллинированному пептиду (АЦЦП). Для оценки рентгенологического прогрессирования РА использовали метод Sharp в модификации van der Heijde. Экспрессию генов в клетках периферической крови определяли посредством обратно-транскриптазной реакции и полимеразной цепной реакции в режиме реального времени.Результаты и обсуждение. На фоне терапии МТ отмечено снижение активности заболевания по индексу DAS28, уровня СРБ, длительности утренней скованности, ЧБС и ЧПС. Через 2 года статистически значимых изменений числа эрозий не выявлено, тогда как число суставов с сужением суставной щели к концу исследования увеличилось (р=0,004). Лечение МТ приводило к уменьшению экспрессии АМРК. При этом больные, достигшие ремиссии, имели наибольший уровень АМРК до терапии, как и серонегативные пациенты, по сравнению с серопозитивными. На основании ROC-анализа определено пороговое значение экспрессии гена АМРК, позволяющее прогнозировать высокую вероятность положительного эффекта терапии МТ.Заключение. Экспрессия гена АМРК связана с активностью заболевания. Его высокий начальный уровень в крови больных РА ассоциируется с большей эффективностью МТ и, возможно, играет протективную роль. При показателе экспрессии гена АМРК, превышающем 3,83, высока вероятность положительного ответа на МТ