Search

The 51st meeting of the Commission Internationale pour L'Etude et L'Amelioration de L'Ensignment des Mathematiques (CIEAEM) was held July, 1999 at Chichester, UK and facilitated the collaboration of delegates from over 30 countries providing a variety of perspectives on the theme OCultural Diversity in Mathematics Education'. The papers in this book concern the relevance and significance of mathematics in art, culture, and the humanities in the modern world. After first recalling knowledge of early mathematical development in Egypt, Babylonia, China and India, the book assesses present-day consequences of the availability of cheap modern technology from computers, hand-held calculators, and the Internet. It focuses on the variety of beliefs, both religious and cultural, and perceptual differences and practices among mathematicians and mathematics educators internationally, and on the vocational aspects in business, commerce, science, and everyday life. There is coverage of student diversity and interest and their varying abilities, aptitudes, and backgrounds with regard to teaching strategies at all levels of mathematics instruction. The contents focus on five major themes of the conference: (1) "Looking Back, Moving Forward"; (2) "Effective Cooperation between Mathematicians, Mathematics Educators, and Uses of Mathematics"; (3) "Coping with Diversity of Student Interest, Abilities, Aptitudes and Background"; (4) "Mathematics Cultures Across Different Sectors of Education"; and (5) "Beliefs and Practices in Mathematics and Mathematics Education". (KHR)

Measurement of O2 consumption, conjugated dienes, and decomposition products of lipid hydroperoxide (LHP) such as malondialdehyde have been extensively used as markers of lipid peroxidation (1). Glutathione (GSH) and glutathione disulfide (GSSG) are biologically important intracellular thiols, and alterations in the GSH/GSSG ratio are often used to assess exposure of cells to oxidative stress. GSH plays an important role in scavenging free radicals and protects cells against several toxic oxygen-derived chemical species. A constant supply of reduced glutathione is necessary to repair the effects of spontaneous oxidation of sulfhydryl groups, which results in cell-membrane damage. [ABSTRACT FROM AUTHOR]

Glutamate is an excitatory transmitter released from neurons. It communicates information rapidly by activating receptors in other neurons (1). Physiologic concentrations of glutamate are 1 μM extracellularly and several millimolar intracellularly. Higher extracellular levels lead to cytotoxicity in the neurons (2). Glutamate exerts its excitatory action via ligand-gated ion channels to enhance Na+/Ca++conductance. There are two types of glutamate receptors: ionotropic and metabotropic. The ionotropic receptors are comprised of three families with intrinsic cation permeable channels (Na+and K+): N-methyl-D-aspartate (NMDA), 2-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA), and kainate. The latter two families are known as the nonNMDA receptors (3,4). The metabotropic receptors, on the other hand, are G protein-coupled subunits, which release secondary messengers in the cytoplasm or influence ion channels through the release of G-protein subunits within the membrane (4). Vesicles in presynaptic terminals release glutamate via a calcium-dependent mechanism. Glutamate released from pre-synaptic structures is not enzymatically degraded. Instead, it is taken up by transporters, which directly regulate extracellular glutamate concentrations and limit excitotoxicity (5,6). [ABSTRACT FROM AUTHOR]

"Satellite Communication is one of the most impressive spin-offs from the space programmes and has made a major contribution to, indeed totally altered, the patterns of International communication. Communication by satellite evolved from the simple technology of "Early Bird" to the highly sophisticated present-day satellites" [1]. The potential of the outer space as a communication hub is great and at the heart of this is the satellite. This paper aims at developing a micro-satellite, which can be used for educational purposes as well as a stepping stone for further complex developments. Data from this satellite will be formatted on the basis of the CCSDS (Consultative Committee for Space Data Systems) standards before transmission. We will also highlight one of the simplest designs of the micro satellite CanSat (Satellite in a can) at university level with most cheaply and easily available resources ever highlighted for the Space Education in Asia. [ABSTRACT FROM AUTHOR]

In this paper we analyze irregular clocking in stream ciphers against algebraic attacks. Algebraic attacks and fast algebraic attacks are a very strong development in the cryptanalysis of stream ciphers with linear feed back. A recent research has shown clock-controlled stream ciphers also vulnerable to algebraic attacks. We have found that if all the registers involved in a key-stream generator are irregularly clocked then it is resistant against algebraic attacks. A5 key-stream generator also having all the irregularly clocked LFSRs is analyzed as an illustration. We have developed algebraic equations for A5 generator using algebraic normal form of its majority function. But increase in the degree of the equations with each clock makes this attack infeasible for this type of clock-controlling. [ABSTRACT FROM AUTHOR]

Stream ciphers play an especially important role in cryptographic practices-both diplomatic and military. One of main approaches used in stream ciphers and key stream generators construction is to develop a design which is resistant to all known attacks. In this paper we have compared the 34 submissions of the on-going stream cipher project: e-STREAM, on the basis of cryptanalytic attacks mounted on them so far. An analysis of these attacks reveals not only the weakness found in the ciphers but also highlights the ways to make that design stronger than before. Study of the newly proposed ciphers with proposed attacks on them also gave an insight into the recent trends in the design and security criteria of stream ciphers. [ABSTRACT FROM AUTHOR]

The 3D scans of human bodies contain over hundreds of thousand grid points. To be used effectively for analysis, indexing, searching, clustering and retrieval, these human bodies requires a compact shape representation. We have developed compact representations based on human body shape based on lengths mostly between joints of single large bones and in the second method silhouettes of the human body are created and then encoded as Fourier shape descriptors. We also have developed two such compact representations based on human head shape by applying Principal Component Analysis on the facial surface and in the second method the whole head is transformed to a spherical coordinate system expanded in a basis of Spherical Harmonics. [ABSTRACT FROM AUTHOR]

In this paper, we consider the design of a morphing airfoil for improved aileron effectiveness using the spectral level set methodology. This methodology is a framework to formulate topology optimization of interfaces based on the level set methods, which represent the interface as the zero level set of a function. As this function evolves, during the optimization process, topological changes of the interface are easily described. According to our formulation, the Fourier coefficients of the level set function are the design variables of the optimization problem. An advantage of the proposed methodology, for a sufficiently smooth interface, is to admit an error asymptotically smaller than the one for non-adaptive spacial discretizations of the level set function. In this case, the methodology could lead to a reduction of the design space dimension. Another advantage is the nucleation of holes in the interior of the interface. As an application, we consider an airfoil with a system of actuators distributed along its chord. This system provides morphing capability to the airfoil by operating on its camber to increase lift generation. The optimization problem consists in determining the camber profile that minimizes the actuation power while improving the airfoil effectiveness. The sign of the level set function determines which actuators are activated. [ABSTRACT FROM AUTHOR]

We present NPP - a new framework for online routing of bandwidth guaranteed paths with local restoration. NPP relies on the propagation of only aggregate link usage information [2,9] through routing protocols. The key advantage of NPP is that it delivers the bandwidth sharing performance achieved by propagating complete per path link usage information [9], while incurring significantly reduced routing protocol overhead. We specify precise implementation models for the restoration routing frameworks presented in [1] and [2] and compare their traffic placement characteristics with those of NPP. Simulation results show that NPP performs significantly better in terms of number of LSPs accepted and total bandwidth placed on the network. For 1000 randomly selected LSP requests on a 20-node homogenous ISP network [8], NPP accepts 775 requests on average compared to 573 requests accepted by the framework of [2] and 693 requests accepted by the framework of [1]. Experiments with different sets of LSP requests and on other networks indicate that NPP results in similar performance gains. [ABSTRACT FROM AUTHOR]

Herbal medicine is gaining rapid acceptance all over the world. Our earliest knowledge of herbal medicine, also termed as &quote;naturomedicine,&quote; dates back to about 3000 bc when Chinese, Islamic-tibb, and Ayurvedic medicine in India were widely practiced. It is possible to trace back written records as well as unwritten knowledge of the rural people of herbal medicine and its use in the treatment of many physiological disorders. Thus in Mesopotamia, the cradle of Western culture, Sumerian tablets record 1000 medicinal plants. Egyptian, Greek, Roman, and Persian civilizations have been particularly rich in herbal medicine. [ABSTRACT FROM AUTHOR]

The development of controlled-release drug-delivery systems that can achieve an effective concentration for a specific period has been investigated using various drug carriers (1). [ABSTRACT FROM AUTHOR]