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Search Results: 1 - 10 of 8304 matches for " Victor Rodov "
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Rosmarinic Acid-Rich Extracts of Summer Savory (Satureja hortensis L.) Protect Jurkat T Cells against Oxidative Stress
Irakli Chkhikvishvili,Tamar Sanikidze,Nunu Gogia,Tamar Mchedlishvili,Maia Enukidze,Marine Machavariani,Yakov Vinokur,Victor Rodov
Oxidative Medicine and Cellular Longevity , 2013, DOI: 10.1155/2013/456253
Abstract: Summer savory (Satureja hortensis L., Lamiaceae) is used in several regions of the world as a spice and folk medicine. Anti-inflammatory and cytoprotective effects of S. hortensis and of its rosmarinic acid-rich phenolic fraction have been demonstrated in animal trials. However, previous studies of rosmarinic acid in cell models have yielded controversial results. In this study, we investigated the effects of summer savory extracts on H2O2-challenged human lymphoblastoid Jurkat T cells. LC-MS analysis confirmed the presence of rosmarinic acid and flavonoids such as hesperidin and naringin in the phenolic fraction. Adding 25 or 50?μM of H2O2 to the cell culture caused oxidative stress, manifested as generation of superoxide and peroxyl radicals, reduced cell viability, G0/G1 arrest, and enhanced apoptosis. This stress was significantly alleviated by the ethanolic and aqueous extracts of S. hortensis and by the partially purified rosmarinic acid fraction. The application of an aqueous S. hortensis extract doubled the activity of catalase and superoxide dismutase in the cells. The production of IL-2 and IL-10 interleukins was stimulated by H2O2 and was further enhanced by the addition of the S. hortensis extract or rosmarinic acid fraction. The H2O2-challenged Jurkat cells may serve as a model for investigating cellular mechanisms of cytoprotective phytonutrient effects. 1. Introduction Summer savory (Satureja hortensis L.) is an herb of the Lamiaceae family that is used in cooking and folk medicine in several regions of the world [1]. In Georgia, dried and ground summer savory (local name kondari) is one of the most popular spices, used either on its own or as an ingredient in spice blends. In addition, from ancient times, it has been known locally as an antimicrobial folk remedy for gastrointestinal problems [2]. Indigenous landraces of summer savory are cultivated in Georgia [3]. The leaves of summer savory are rich in phenolic compounds, particularly rosmarinic acid and flavonoids, which account for the high antioxidant capacity of these leaves [4, 5]. In our previous study of Georgian spices, we found that kondari had one of the highest total phenolic content levels and one of the highest hydrophilic antioxidant capacity levels [6]. Rosmarinic (α-O-caffeoyl-3,4-dihydroxy-phenyl lactic) acid was found to be the major compound in ethanolic extracts of summer savory and some other Lamiaceae herbs [4]. Rosmarinic acid is a phenylpropanoid derivative that is the second most common ester of caffeic acid in the plant kingdom. Animal studies have revealed
The Analysis of Accelerograms for the Earthquake Resistant Design of Structures  [PDF]
Victor Corchete
International Journal of Geosciences (IJG) , 2010, DOI: 10.4236/ijg.2010.11004
Abstract: In this paper, the analysis of ground motions (displacements, velocities and accelerations) has been performed focused to the seismic design. The relationships between the peak ground acceleration (PGA), the peak ground velocity (PGV), the peak ground displacement (PGD) and the bracketed duration, with the earthquake magnitude, are presented and their validity and applicability for seismic design is discussed. Finally, the dominant periods of the ground motions (displacement, velocity and acceleration) are obtained from their Fourier Spectrum. Their validity and applicability for the seismic design is discussed also. The results presented in this paper show that the relationships that exist between the important parameters: PGA, PGV, PGD and duration; and the earthquake magnitude, allow the prediction of the values for these parameters, in terms of the magnitude for future strong motions. These predictions can be very useful for seismic design. Particularly, the prediction of the magnitude associated to the critical acceleration, because the earthquakes with magnitude greater than this critical magnitude can produce serious damages in a structure (even its collapsing). The application of the relationships obtained in this paper must be very careful, because these equations are dependent on the source area, location and type of structure. The dominant periods of the ground motions (displacement, velocity and acceleration) that are computed and presented in this paper, are also important parameters for the seismic design, because recent studies have shown that the earthquake shaking is more destructive on structures having a natural period around some of these dominant periods. These parameters must also be handled with caution, because they show dependence with the source area, location and type of structure.
The SAFEX-JIBAR Market Models  [PDF]
Victor Gumbo
Journal of Mathematical Finance (JMF) , 2012, DOI: 10.4236/jmf.2012.24035
Abstract: It is possible to construct an arbitrage-free interest rate model in which the LIBOR rates follow a log-normal process leading to Black-type pricing formulae for caps and floors. The key to their approach is to start directly with modeling observed market rates, LIBOR rates in this case, instead of instantaneous spot rates or forward rates. This model is known as the LIBOR Market Model. We formulate the SAFEX-JIBAR market model based on the fact that the forward JIBAR rates follow a log-normal process. Formulae of the Black-type are deduced.
Wave Equation Simulation Using a Compressed Modeler  [PDF]
Victor Pereyra
American Journal of Computational Mathematics (AJCM) , 2013, DOI: 10.4236/ajcm.2013.33033

Repeated simulations of large scale wave propagation problems are prevalent in many fields. In oil exploration earth imaging problems, the use of full wave simulations is becoming routine and it is only hampered by the extreme computational resources required. In this contribution, we explore the feasibility of employing reduced-order modeling techniques in an attempt to significantly decrease the cost of these calculations. We consider the acoustic wave equation in two-dimensions for simplicity, but the extension to three-dimensions and to elastic or even anysotropic problems is clear. We use the proper orthogonal decomposition approach to model order reduction and describe two algorithms: the traditional one using the SVD of the matrix of snapshots and a more economical and flexible one using a progressive QR decomposition. We include also two a posteriori error estimation procedures and extensive testing and validation is presented that indicates the promise of the approach.

A Fractal Space-Time Structure of Nonequilibrium Living Systems Is Essential Property and Fractal Property of Dynamics Systems on Cosmic Scales Is Foundation for the Origin of the Living Systems  [PDF]
Victor Gusev
Open Journal of Biophysics (OJBIPHY) , 2014, DOI: 10.4236/ojbiphy.2014.42007
The experimental data represented in the bibliography are theoretically analyzed to construct an adequate model for dynamics of an open nonequilibrium living system. It is shown that the viable microorganisms are capable of forming the fractal structure, whose dimensionality is certainly non-integral. In addition, we have attempted to provide a generalized description of the properties of living and nonliving matter (in the addition to that described in work [1]). Relevant published data were used to demonstrate a fractal structure of the space in the vicinity of centrally gravitating bodies with satellites revolving around them along closed trajectories and serving as a kind of testers of the neighboring space. A local violation of its discontinuity is likely to be a necessary (yet not sufficient!) dynamic characteristic of the spatiotemporal continuum for self-organization of molecules into a living, i.e., self-replicating, system.
Teachers’ Perceptions about the Use of Play to Facilitate Development and Teach Prosocial Skills  [PDF]
Michelle Haney, Victor Bissonnette
Creative Education (CE) , 2011, DOI: 10.4236/ce.2011.21006
Abstract: The purpose of this study was to investigate teachers’ perceptions about the use of play to promote social, emotional, and cognitive skills to support planning for a school program aimed at increasing inclusive play for young children. This research was inspired by Vivian Gussin Paley’s book, You Can’t Say You Can’t Play (1992). Participants included undergraduate students and graduate education students in the Teacher Education Program at a small liberal arts college, as well as practicing elementary school teachers. The results indicated that graduate students and practicing teachers had a more accurate understanding about the developmental benefits of incorporating play into the classroom and a greater willingness to embrace the “you can’t say you can’t play” rule to promote inclusive play and acceptance. Implications for designing a preventative program for inclusive play in young children are discussed.
Semantic model and optimization of creative processes at mathematical knowledge formation  [PDF]
Victor Egorovitch Firstov
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.28113
Abstract: The aim of this work is mathematical education through the knowledge system and mathematical modeling. A net model of formation of mathematical knowledge as a deductive theory is suggested here. Within this model the formation of deductive theory is represented as the development of a certain informational space, the elements of which are structured in the form of the orientated semantic net. This net is properly metrized and characterized by a certain system of coverings. It allows injecting net optimization parameters, regulating qualitative aspects of knowledge system under consideration. To regulate the creative processes of the formation and realization of mathematical know- edge, stochastic model of formation deductive theory is suggested here in the form of branching Markovian process, which is realized in the corresponding informational space as a semantic net. According to this stochastic model we can get correct foundation of criterion of optimization creative processes that leads to “great main points” strategy (GMP-strategy) in the process of realization of the effective control in the research work in the sphere of mathematics and its applications.
Barriers to Placement of Spirometers in Clinics Affiliated with an Academic Medical Center  [PDF]
Victor O. Kolade
International Journal of Clinical Medicine (IJCM) , 2012, DOI: 10.4236/ijcm.2012.31006
Abstract: United States physician office visits for asthma have increased since 1989, and most of these visits are to primary care physicians. The National Institutes of Health has published guidelines for asthma diagnosis and management, implementation of which is expected to result in improved care and reduced costs. Compliance with asthma guidelines has been suboptimal, especially with spirometry recommendations, and more so in primary care clinics than in specialist clinics. Noncompliance has largely been attributed to physician and patient factors. This paper describes an experience with navigation of health system barriers to implementation of spirometry encountered at three primary care clinics affiliated with an internal medicine residency program. Included are perspectives and priorities of key individuals, systems issues related to institutions, and technical issues pertaining to spirometers. Navigation of ACGME core competencies is discussed.
Multidimensional Laplace Transforms over Quaternions, Octonions and Cayley-Dickson Algebras, Their Applications to PDE  [PDF]
Sergey Victor Ludkovsky
Advances in Pure Mathematics (APM) , 2012, DOI: 10.4236/apm.2012.22013
Abstract: Multidimensional noncommutative Laplace transforms over octonions are studied. Theorems about direct and inverse transforms and other properties of the Laplace transforms over the Cayley-Dickson algebras are proved. Applications to partial differential equations including that of elliptic, parabolic and hyperbolic type are investigated. Moreover, partial differential equations of higher order with real and complex coefficients and with variable coefficients with or without boundary conditions are considered.
Optimality Conditions and Algorithms for Direct Optimizing the Partial Differential Equations  [PDF]
Victor K. Tolstykh
Engineering (ENG) , 2012, DOI: 10.4236/eng.2012.47051
Abstract: New form of necessary conditions for optimality (NCO) is considered. They can be useful for design the direct infinite- dimensional optimization algorithms for systems described by partial differential equations (PDE). Appropriate algo-rithms for unconstrained minimizing a functional are considered and tested. To construct the algorithms, new form of NCO is used. Such approach demonstrates fast uniform convergence at optimal solution in infinite-dimensional space.
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