A Determination of the Initial Level of the Brillouin Frequency Shift in Optical Fibers of Different Kinds

A dependence of the hyper-acoustic wave velocity on characteristics of the optical fiber core is analyzed in this paper. The values of Brillouin frequency shifts for various types of optical fibers at room temperature and without longitudinal tensile force are presented. Having database of profiles of the Mandelstam – Brillouin backscattering spectrums for fibers of different kinds and manufacturers allow to classify the optical fibers in the optical cables and detect damaged sections of fiber optical communication line. Keywords: optical fiber, strain, Brillouin frequency shift, Brillouin reflectometry, hyper-acoustic wave

COMPETENCY CONCEPTS ANALYSIS IN THE SYSTEM OF COMPUTER MODELING OF EDUCATIONAL TASKS

The article discusses the necessity of creating competency based tasks for computer educational models. This requires clarification of competency concept as well as the methods of its measurement. Several approaches to understanding competency and its definition have been analyzed. It is obvious that the majority of those do not describe development of measurement instruments for competency levels. Some of the discussed approaches make it possible to split the competency into separate components and consider the activities leading to upgraded competencies. The author provides definitions of competency and competency level. Competency is a mental construct which is a certain unity of a person’s skills required within definite context of activity for a definite set of possible tasks. Competency always describes “unity of two” – 1) set of tasks in the context; 2) the performer. Competency level is an index, characterizing the probability of successful performing of the task (on the given level) out of a definite set (variety) of tasks in the defined context by the definite performer. The experimental and indirect methods of competency measurement have been described. It is possible to view the construction of the competency from two different points: which parts (ingredients) and which components it includes. Parts (ingredients) are knowledge, skills, behaviours, attitudes, etc. Components are minor competencies aimed to solve minor auxiliary tasks. Thus, in order to solve a competency task it is necessary to solve a few easier tasks which would complete some zones of competency. The proposed approach describes the theory of competency level and structure measurement being a basis for competencies forming management. The mentioned approach requires more detailed development which is viewed as the matter of further research and publications

Inhibition of p70 S6 Kinase (S6K1) Activity by A77 1726 and Its Effect on Cell Proliferation and Cell Cycle Progress

AbstractLeflunomide is a novel immunomodulatory drug prescribed for treating rheumatoid arthritis. It inhibits the activity of protein tyrosine kinases and dihydroorotate dehydrogenase, a rate-limiting enzyme in the pyrimidine nucleotide synthesis pathway. Here, we report that A77 1726, the active metabolite of leflunomide, inhibited the phosphorylation of ribosomal protein S6 and two other substrates of S6K1, insulin receptor substrate-1 and carbamoyl phosphate synthetase 2, in an A375 melanoma cell line. A77 1726 increased the phosphorylation of AKT, p70 S6 (S6K1), ERK1/2, and MEK through the feedback activation of the IGF-1 receptor–mediated signaling pathway. In vitro kinase assay revealed that leflunomide and A77 1726 inhibited S6K1 activity with IC50 values of approximately 55 and 80 μM, respectively. Exogenous uridine partially blocked A77 1726–induced inhibition of A375 cell proliferation. S6K1 knockdown led to the inhibition of A375 cell proliferation but did not potentiate the antiproliferative effect of A77 1726. A77 1726 stimulated bromodeoxyuridine incorporation in A375 cells but arrested the cell cycle in the S phase, which was reversed by addition of exogenous uridine or by MAP kinase pathway inhibitors but not by rapamycin and LY294002 (a phosphoinositide 3-kinase inhibitor). These observations suggest that A77 1726 accelerates cell cycle entry into the S phase through MAP kinase activation and that pyrimidine nucleotide depletion halts the completion of the cell cycle. Our study identified a novel molecular target of A77 1726 and showed that the inhibition of S6K1 activity was in part responsible for its antiproliferative activity. Our study also provides a novel mechanistic insight into A77 1726–induced cell cycle arrest in the S phase

СИСТЕМОУТВОРЮВАЛЬНІ ФАКТОРИ СИСТЕМИ ДИСТАНЦІЙНОГО НАВЧАННЯ У ЗАГАЛЬНООСВІТНІХ НАВЧАЛЬНИХ ЗАКЛАДАХ: ОГЛЯД

Ефективне проектування й упровадження систем дистанційного навчання (СДН) потребує застосування відповідного системного аналізу таких систем. На основі аналізу теоретичних й експериментальних досліджень систем дистанційного навчання у статті визначено системоутворювальні фактори існування і функціонування цих систем на різних етапах життєвого циклу. Розглянуто підходи до формування переліку системоутворювальних факторів, визначення ієрархії і взаємозв’язків цих факторів, експериментального визначення кількісних значень впливу окремих факторів на результативність системи дистанційного навчання. Зазначається, що врахування системоутворювальних факторів сприятиме створенню ефективних систем дистанційного навчання. Пропонується створення адаптивних середовищ дистанційного навчання, які самомодифікуються відповідно до встановлених цілей

METHOD OF WEBINAR ORIENTED PLATFORMS APPLICATION IN HIGH SCHOOL LEARNING PROCESS OF COMPUTER SCIENCE

This article explores some components of method of webinar oriented platforms application in computer science of high school. The webinar’s forms and methods of computer science teaching are analyzed. The classification of teaching methods of computer science in virtual environment based on information and communication technologies is developed