bluuebunny/crossref_metadata_2025 huggingface dataset:
The Relationship of Normal and Abnormal Microstructural Proliferation to the Mitral Valve Closure Sound
Authors: Einstein Daniel R. , Kunzelman Karyn S. , Reinhall Per G. , Nicosia Mark A. , Cochran Richard P.
Published: March 2005

Background : Many diseases that affect the mitral valve are accompanied by the proliferation or degradation of tissue microstructure. The early acoustic detection of these changes may lead to the better management of mitral valve disease. In this study, we examine the nonstationary acoustic effects of perturbing material parameters that characterize mitral valve tissue in terms of its microstructural components. Specifically, we examine the influence of the volume fraction, stiffness and splay of collagen fibers as well as the stiffness of the nonlinear matrix in which they are embedded. Methods and Results: To model the transient vibrations of the mitral valve apparatus bathed in a blood medium, we have constructed a dynamic nonlinear fluid-coupled finite element model of the valve leaflets and chordae tendinae. The material behavior for the leaflets is based on an experimentally derived structural constitutive equation. The gross movement and small-scale acoustic vibrations of the valvular structures result from the application of physiologic pressure loads. Material changes that preserved the anisotropy of the valve leaflets were found to preserve valvular function. By contrast, material changes that altered the anisotropy of the valve were found to profoundly alter valvular function. These changes were manifest in the acoustic signatures of the valve closure sounds. Abnormally, stiffened valves closed more slowly and were accompanied by lower peak frequencies. Conclusion: The relationship between stiffness and frequency, though never documented in a native mitral valve, has been an axiom of heart sounds research. We find that the relationship is more subtle and that increases in stiffness may lead to either increases or decreases in peak frequency depending on their relationship to valvular function.
A push-me–pull-you water-driven wheeled vehicle
Authors: Rubčić A. , Baturić-Rubčić J.
Published: March 2005

A model rail vehicle driven by a flow of water has been constructed and investigated. Instead of railway sleepers, a channel with a water stream running between the rails is required. The ‘‘engine’’ of the vehicle is an ordinary water wheel, which draws energy from the water. Both upstream and downstream motions are possible. Theoretical and experimental characteristics of the vehicle are demonstrated.
The effect of spin on the flight of batted baseballs
Authors: Rex A. F.
Published: March 2005

Distances traveled by batted baseballs with various spin types and rates have been calculated using a computer. It is found that balls hit with backspin tend to travel farther than balls hit with little spin or topspin, particularly for lower trajectories. Two types of hits are considered specifically: the long fly ball of potential home run distance and the low line drive to the outfield.
Stroboscopic study of the inverted pendulum
Authors: Michaelis M. M.
Published: March 2005

A portable jigsaw is adapted to provide an inexpensive large-scale demonstration of the inverted pendulum experiment. Stroboscopic study reveals interesting features of the motion of the inclined pendulum, as well as the possibility that no pendulum is ever quite inverted. Kalmus [Am. J. Phys. 38, 874 (1970)] and Kapitza [Collected Papers by P. L. Kapitza, edited by D. TerHaar (Pergamon, London, 1965)] theories are used as analogs to study the behavior of the inverted and the partially inverted pendulum.
Phasemeters and their use in the undergraduate physics laboratory
Authors: van der Merwe J. P.
Published: March 2005

In introductory courses on alternating current circuits a discussion is normally included on the difference in phase between the voltage across a reactive circuit element and the current through it, or between the voltages across two circuit elements. For the experimental measurement of phase angles the dual-trace oscilloscope can be used profitably, but it may not always form part of the work station of first-year university or college laboratories. A discussion is given here of simple circuits which allow a phase angle to be displayed on digital or analog voltmeters or microammeters. The circuits each use a single integrated circuit, and are inexpensive to construct.
The principle of equivalence and a theory of gravitation
Authors: Shelupsky David
Published: March 2005

We examine a well-known thought experiment often used to explain why we should expect a ray of light to be bent by gravity; according to this the light bends downward in the gravitational field because this is just what an observer would see if there were no field and he were accelerating upward instead. We show that this description of the action of Newtonian gravity in a flat space-time corresponds to an old two-index symmetric tensor field theory of gravitation.
The Lorentz-invariant vacuum medium
Authors: Shupe Michael A.
Published: March 2005

In teaching courses on special relativity, we should take care to emphasize that experiments done to date are tests of Lorentz invariance up to the momenta accessible to modern equipment. Specifically, these experiments do not verify the two postulates of special relativity. There is still the possibility that space is permeated by a medium which supports the propagation of particles, and that this medium will eventually be detected.
Book authorship and the physics professoriate
Authors: Zebrowski Ernest , Weidman John C.
Published: March 2005

This paper documents the book-writing and research activities of the Pennsylvania physics/astronomy professoriate and, by extrapolation, examines whether college physics textbooks are representative of the academic mainstream in the discipline.
Energy laboratory
Authors: Dart S. Leonard
Published: March 2005

As the next step beyond the laboratory exercises illustrating Newton’s laws of motion, a laboratory exercise has been developed based on potential energy functions. This exercise uses magnets in conjunction with an ordinary air track to form potential hills and wells of various shapes (such as an alpha potential). The properties of bound states and their natural frequencies can be studied and related to the particle in a box, simple harmonic motion, etc.
On return to thermal equilibrium for the excess charge distribution in semiconductors
Authors: Paranjape V. V.
Published: March 2005

The relaxation time for the return to thermal equilibrium for the excess charge distribution in metals and in semiconductors is shown to be longer than the relaxation time derived in many textbooks. In semiconductors the relaxation of charge is accompanied by an increase in temperature of the charged carriers. The time of decay τT for the temperature is considerably longer than the time of decay for the excess charge. Hence the overall relaxation time for attaining thermal equilibrium is determined by τT.
Mechanical model for a first-order phase transition
Authors: Sivardière Jean
Published: March 2005

The usual Alben mechanical model exhibits a second-order instability which corresponds to a spontaneous symmetry breaking. It is shown that an asymmetrical version of this model exhibits a first-order instability.
Physics-computing major
Authors: Smith P. A. , Seligmann P. F. , Spencer C. D.
Published: March 2005

A major composed of electronics, programming, and physics has been introduced at Ithaca College. The specific objective is to give students a background in hardware and software sufficient for them to apply microcomputers to a variety of on-line tasks. The broader objective is to prepare students for careers in the computer industry. Since the major was introduced, the number of upper-class students has passed 40 after averaging ten in previous years. The environment in which the major evolved is described; the curriculum is outlined; the resources required are listed; and the impact on students and the department is discussed.
Boltzmann temperature: An instructional experiment for the advanced laboratory
Authors: Knudsen Arthur W.
Published: March 2005

An experiment is described which, in a very fundamental way, introduces students at the advanced undergraduate level to the concept of temperature. The method involves analyzing the motions of electrons emitted from the hot cathode of a 6CG3 vacuum tube (the so-called ‘‘Boltzmann method’’ of temperature determination). In addition the student finds the cathode temperature by the more conventional method of optical pyrometry. Accuracy, objectivity, and simplicity in all phases of the work have been emphasized. Agreement between the two methods of temperature determination is possible to within a small fraction of one percent. The experiment is designed for use in the advanced undergraduate laboratory.
Systematic comparison of the quantization rules of hydrogenoid atoms in the Old Quantum, Schrödinger, Klein–Gordon, and Dirac theories, by means of a common set of three parameters
Authors: Levy A. A.
Published: March 2005

A set of three parameters λ, β, and δ related to energy E and angular momentum L were used to make the closest possible formal comparison between the five successive theories of the quantization of the energy levels of the hydrogenoid atoms. The expression of the quantization rules was made uniform and the differences between the theories were reduced to simple redefinitions of the parameters.
Scattering approach to Fresnel’s equations and Brewster’s law
Authors: Doyle William T.
Published: March 2005

A factored form of Fresnel’s equations for arbitrary transparent media is presented. The two factors separately express the scattering pattern of the individual dipoles and the coherent scattering function of the dipole array. The new form facilitates comparison with the scattering interpretation of reflection and refraction. It is used to develop a new scattering model of Brewster’s law.
Old quantum mechanics and perturbation theory
Authors: Sivardière Jean , Belorizky Elie
Published: March 2005

Two physical systems—the particle in a double rectangular well and the anharmonic oscillator—are treated in the Bohr–Sommerfeld–Wilson semiclassical theory. The results agree with the Van Vleck perturbation theory.
Negative energy states of an ‘‘inverted’’ delta potential: Influence of boundary conditions
Authors: Rabinovitch A.
Published: March 2005

Negative energy solutions are obtained for the one-dimensional Schrödinger equation with an inverted delta potential. Several boundary conditions are treated and the eigenvalues and eigenfunctions calculated. It is shown that there are either a single or at most two eigenvalues for each boundary condition. Consequently this example can be used as a device to compare different physical models.
Relationship between angular distribution of reflected particles and the second principle of thermodynamics in the presence of a magnetic field
Authors: Berger Jorge
Published: March 2005

The equivalence between the second principle of thermodynamics and the Lambert cosine law, which has for a long time been noticed for particles moving in straight trajectories, is shown to hold as well in the presence of a magnetic field. As a corollary, the cosine law is a necessary condition under which the absence of diamagnetism in classical statistics holds.
Effect of the boundary conditions on the accuracy of perturbation theory
Authors: Coronado M. , Domínguez N. , Flores J. , de la Portilla C.
Published: March 2005

The problems of a square well in quantum mechanics, a slab reactor in neutron diffusion theory, and a planar dielectric waveguide imply solving the same second-order differential equation but with different boundary conditions. In order to study the influence of different boundary conditions on the accuracy of first- and second-order perturbation theory, the above problems are solved both exactly and by perturbation methods for the case of three slabs. A numerical comparison shows that the simpler the boundary conditions are, the more accurate the results of perturbation theory become.
How not to focus a small source with a single lens
Authors: Heaps William S.
Published: March 2005

It has been observed that when focusing a small finite source onto a fixed image plane with a single lens, the focus position does not necessarily correspond to the minimum imaged spot size. A simple analysis of this situation illuminates conditions under which it may arise.
The appropriate use of microcomputers in undergraduate physics labs
Authors: Briotta D. A. , Seligman P. F. , Smith P. A. , Spencer C. D.
Published: March 2005

In undergraduate physics lab courses, microcomputers can provide a powerful increase in measurement capabilities over traditional physics instrumentation. However, the implementation of computerized labs must be carefully designed to prevent the machines from obscuring the physics of the experiment. When appropriately used, the power of the computer can help to illuminate the physics of an experiment rather than merely to automate data collection and analysis. Guidelines are presented, along with several experiments, to show the appropriate use of microcomputers in a teaching environment.
The Bezold–Brücke phenomenon and Goethe’s rejection of Newton’s O
p
t
i
c
k
s
Authors: Duck Michael
Published: March 2005

It is beyond dispute that the main objective of the polemical part of Goethe’s Farbenlehre, namely, the refutation of Newton’s Opticks, was a misguided one. Many consider it to be inexplicable that a man of Goethe’s intellectual standing should have behaved in such an apparently irrational manner. It so happens, however, that the characteristics of the subjective spectrum are more akin to Goethe’s model than to Newton’s. It is true that Goethe put an incorrect interpretation upon what he saw—and was the first to see—but a careful scrutiny of his scientific method reveals that his reasoning was far from irrational.
Order-of-magnitude ‘‘theory’’ of stellar structure
Authors: Greenstein George
Published: March 2005

A rough order-of-magnitude analysis is made of the equations of stellar structure. Analytic formulas are derived for the luminosity, radius, and mass as functions of the temperature. These formulas, while highly approximate, provide a simple, analytically tractable model of a star.
Production of real-time holographic interferograms
Authors: Lubell Keith , Prigo Robert
Published: March 2005

The equipment and procedure needed to produce, view, and record good quality real-time holographic interferograms in the undergraduate laboratory are described in step-by-step detail. Major concerns in the production, processing, and viewing are discussed further. Some investigations are suggested.
Stabilization parachutes: A rigid body treatment
Authors: Jones D. F. , Desmier P. E.
Published: March 2005

Rigid body dynamics are used to describe the motion of parachute-payload systems released from aircraft. Two models are developed to describe the transitional and rotational degrees of freedom using the dynamical equations of Newton and Lagrange. The latter mechanics treats the parachute and payload as two rigid bodies in contact, while the former mechanics treats the entire system as a single rigid body. Finally, the equations of motion deduced from the Newtonian approach are numerically solved for a stabilization parachute to show the effects of wind and of suspension line length on damping.
Ground trajectories of geosynchronous satellites and the analemma
Authors: Chalmers Joseph S.
Published: March 2005

The mathematics describing the appearance of the ground trajectories of geosynchronous satellites is given in terms of vector geometry and orbital mechanics in a form familiar to physics students. The dependence of the trajectories on orbit inclination, eccentricity, and location of perigee is shown. The formalism is also seen to apply to the description of the analemma and to permit prediction of the appearance of the analemma in future epochs.
Quantum and classical electrons in a potential well with uniform electric field
Authors: Nguyen D. , Odagaki T.
Published: March 2005

We calculate the polarization of the quantum and classical electrons confined in a one-dimensional infinite potential well in the presence of a static electric field. As the external field is increased, the polarization always increases for a quantum electron in the ground state, but the polarization of an electron in any excited state decreases for a weak field and increases after passing a minimum. The polarization of a classical electron with nonzero initial kinetic energy is similar to the response of a quantum electron in excited states. The polarization determined by the diffusion equation is similar to the polarization of a quantum electron in the ground state.
An investigation of student understanding of the real image formed by a converging lens or concave mirror
Authors: Goldberg Fred M. , McDermott Lillian C.
Published: March 2005

Student understanding of the real images produced by converging lenses and concave mirrors was investigated both before and after instruction in geometrical optics. The primary data were gathered through interviews in which undergraduates taking introductory physics were asked to perform a set of prescribed tasks based on a simple demonstration. The criterion used to assess understanding was the ability to apply appropriate concepts and principles, including ray diagrams, to predict and explain image formation by an actual lens or mirror. Performance on the tasks, especially by students who had not had college instruction in geometrical optics, suggested the presence of certain naive conceptions. Students who had just completed the study of geometrical optics in their physics courses were frequently unable to relate the concepts, principles, and ray-tracing techniques that had been taught in class to an actual physical system consisting of an object, a lens or a mirror, and a screen. Many students did not seem to understand the function of the lens, mirror, or screen, nor the uniqueness of the relationship among the components of the optical system. Difficulties in drawing and interpreting ray diagrams indicated inadequate understanding of the concept of a light ray and its graphical representation.
Electromechanical implications of Faraday’s law: A problem collection
Authors: Saslow W. M.
Published: March 2005

A collection of problems illustrating the electromechanical implications of Faraday’s law is presented. They are appropriate for well-prepared freshmen and all undergraduate physics majors. A number of interesting examples are worked out analytically, including Thomson’s jumping ring demonstration. They are of interest in part because they include the effects of inductance and capacitance more fully than in the usual textbook treatments.
Does mass really depend on velocity, dad?
Authors: Adler Carl G.
Published: March 2005

Relativistic mass is discussed in both a pedagogical and historical context. It is pointed out that its introduction into the theory of special relativity was much in the way of a historical accident. Gaining widespread use initially in instruction, the use of relativistic mass is showing signs of progressive disfavor. An analysis and criticism of the various ways relativistic mass is used in relativity is detailed and special attention is given to the frequent misuse of relativistic mass as an inertia.
An undergraduate experiment on statistics and errors using a radioactive source and a microcomputer
Authors: McFarland Ernie , MacKenzie Innes , Stone Robert
Published: March 2005

An experiment has been developed for the intermediate physics laboratory in which the students use a microcomputer to investigate statistics and errors. A multichannel scaler is used to collect distributions of events per unit time from a radioactive source, and the data are stored on computer diskettes. Students write programs to calculate properties such as the mean and standard deviation of each distribution, and combine data sets in various ways in order to investigate how errors (standard deviations) are propagated.
Dim1p Is Required for Efficient Splicing and Export of mRNA Encoding Lid1p, a Component of the Fission Yeast Anaphase-Promoting Complex
Authors: Carnahan Robert H. , Feoktistova Anna , Ren Liping , Niessen Sherry , Yates John R. , Gould Kathleen L.
Published: March 2005

Schizosaccharomyces
pombe
Dim1p is required for maintaining the steady-state level of
the anaphase-promoting complex or cyclosome (APC/C) component Lid1p and
thus for maintaining the steady-state level and activity of the APC/C.
To gain further insight into Dim1p function, we have investigated the
mechanism whereby Dim1p influences Lid1p levels. We show that
S.
pombe
cells lacking Dim1p or
Saccharomyces cerevisiae
cells lacking its ortholog, Dib1p, are defective in generalized
pre-mRNA splicing in vivo, a result consistent with the identification
of Dim1p as a component of the purified yeast U4/U6.U5 tri-snRNP
complex. Moreover, we find that Dim1p is part of a complex with the
splicing factor Prp1p. However, although Dim1p is required for
efficient splicing of
lid1

+

pre-mRNA, circumventing the necessity for this particular function of
Dim1p is insufficient for restoring normal Lid1p levels. Finally, we
provide evidence that Dim1p also participates in the nuclear export of
lid1

+

mRNA and that it is likely
the combined loss of both of these two Dim1p functions which
compromises Lid1p levels in the absence of proper Dim1p function. These
data indicate that a mechanism acting at the level of mRNA impacts the
functioning of the APC/C, a critical complex in controlling mitotic
progression.
Interleukin-6 acts as insulin sensitizer on glycogen synthesis in human skeletal muscle cells by phosphorylation of Ser473 of Akt
Authors: Weigert Cora , Hennige Anita M. , Brodbeck Katrin , Häring Hans U. , Schleicher Erwin D.
Published: March 2005

Previous studies showed an insulin-“desensitizing” action of IL-6 on glycogen synthesis in hepatocytes. We recently found no inhibition of the proximal steps of the insulin signal cascade in human skeletal muscle cells. Because these data indicate a possible tissue-specific effect of IL-6, we investigated the influence of IL-6 on insulin-stimulated glycogen synthesis in these cells. At first, we found that incubation of the cells with 20 ng/ml IL-6 alone induced phosphorylation of Ser473 of Akt, but not of Thr308 time dependently and we observed that IL-6 augments insulin-induced Ser473 and Thr308 phosphorylation in the low nanomolar range of insulin. Moreover, IL-6 increased insulin-stimulated phosphorylation of glycogen synthase kinase-3. Accordingly, IL-6 enhanced glycogen synthesis in the presence of 3 and 10 nM insulin, whereas IL-6 alone had only a marginal effect. IL-6 treatment of C57Bl/6 mice readily stimulated phosphorylation of Ser473 in skeletal muscle. Our result that IL-6 did not induce Ser473 phosphorylation in the liver of these mice suggests a tissue-specific effect. Together, our data demonstrate a novel insulin-sensitizing function of IL-6 on glycogen synthesis in skeletal muscle cells and indicate that IL-6 exerts cell/tissue-specific effects on insulin action.
Embodiment and identity in contemporary society: Femina and the ‘new’ Indian woman
Authors: Thapan Meenakshi
Published: March 2005

This article argues that the identity of the ‘new’ Indian woman in the rapidly altering cultural and social imaginary of India is constructed, shaped and redefined in the everyday experiences of women as they both contest and submit to the images and constructs that impinge on their senses, emotions, and material and social conditions. In this context, the article examines samples of advertisements, fashion photography and selected textual material from the Indian women’s magazine Femina to understand how body images serve to construct embodiment and womanhood through the medium of visual representation and textual discourse. The focus in the magazine is on the desirability of woman’s body, not only as a glamorous, well-groomed product, but also as a commercialised product for consumption in an international marketplace, thus affirming that India has arrived in the world of beauty and glamour, and legitimising the recolonisation of Indian woman’s embodiment in the global economy.
Transformation of Enterprises in Russia1
Authors: C. Samal Kishor
Published: March 2005

There have been dramatic changes in the world since 1990. Among all the changes, the transition from a command economy to a market economy has been one of the most important peace events of the 1990s. The developments after the fall of the Berlin Wall in 1989 and the dissolution of the Soviet Union in 1991 sharply accelerated this process of transition. The three important aspects of economic reform in transition economies (i.e., former socialist countries including Russia) are: (a) liberalisation, (b) privatisation and (c) globalisation. Privatisation remains a key step in the policies of transition economies to form a viable market-oriented economy. There are various methods of privatisation such as restitution, direct sales, equity offerings, management-employee buyouts and mass/voucher privatisation. This process of reform and privatisation has brought about a certain transformation of enterprises in Russia. Therefore, the coverage of our study is Russia, and the field study on informal sector was carried out in Moscow, its capital city. The study reported here examines the impact of economic reform, particularly privatisation, on enterprises in Russia, and draws lessons for India from the experience of Russia.
Women and Gender in the Study of Tribes in India
Authors: Xaxa Virginius
Published: March 2005

Concern for a focus on women in tribal studies has been very recent. It emerged out of general interest and concern with women’s issues the world over. The value system governing larger Indian society has been in the process of change. With this there has been a shift in the image of tribal women who are thus invariably portrayed as enjoying a better social status than their counterparts in the larger Indian society. Tribal society in the post-Independence era has been witness to unprecedented change, which has been most marked in respect of culture, modes of making a living and social differentiation. Their bearing on women’s status in society and gender relations has been far-reaching. The article attempts to highlight the issues involved on the basis of existing ethnographic accounts.
Women Workers in the Brick Kiln Industry in Haryana, India
Authors: D.P. Singh
Published: March 2005

A vast majority of the country’s workforce is in the unorganised sector, and consequently unprotected. In the absence of economic opportunities where they live, many migrate across the states of India to seek casual employment. Brick production depends almost entirely on migrant workers, half of whom are women. This paper looks into the socio-economic status of women workers in the brick industry of Haryana and underlines the fact that these workers have a very tough life. While bearing and rearing children remains their primary responsibility, they are invariably involved in economic activities for survival, thus playing roles in both production and reproduction.
Building Technological Capabilities in Latecomer Firms: A Review Essay
Authors: Dutrénit Gabriela
Published: March 2005

The literature on the building up of technological capabilities in industrial latecomer firms has focused on analysing the gradual building of a minimum base of technological knowledge to be able to carry out innovative activities. The literature on strategic management focuses on maintaining, nurturing and renewing core capabilities/competencies by the most innovative firms. This paper argues that there is no simple linear progression from the early stage of accumulation of the minimum levels of innovative capability to the management of knowledge as a strategic asset and the deployment of core capabilities. On the contrary, the transition process is complex and while firms make that transition, they have to build deeper and broader stocks of knowledge and develop new types of knowledge management. This paper reviews those bodies of literature, discusses the lack of attention to the characteristics, problems and strategies of the building up of technological capabilities of large firms that compete close to, but still below, the technological frontier, particularly in the Latin American context, and proposes an analytical framework to analyse firms at this stage of accumulation.
Post-TRIPs Technological Behaviour of the Pharmaceutical Industry in India
Authors: Abrol Dinesh
Published: March 2005

This paper analyses the post-TRIPs behaviour of domestic and foreign pharmaceutical firms in respect of technology acquisition, knowledge transfer and domestic R&D in India. It evaluates the prospects of development of capabilities by domestic firms in a scenario where they have also chosen to enter the markets for generics in developed countries and build relations of subcontracting with multinational corporations in the sphere of R&D and production activities. It suggests that due to the introduction of strong IPRs, pharmaceutical multinationals are now advantageously placed to control knowledge diffusion and integrate the local capabilities of a country like India into their own myopic and narrowly benefiting innovation strategies. Evidence available from the experience of developing countries like India on the diffusion of knowledge contradicts the claim of TRIPs advocates that its adverse effect on prices of patented medicines would be adequately compensated by the benefits of technology transfer and domestic R&D. The domestic industry is told to utilise emerging market opportunities for contract manufacture and R&D in a selective way. The government is asked to intervene with the aim to make the domestic industry undertake technological activities that would allow the Indian pharmaceutical sector to upgrade itself for the benefit of development of therapies for the needs of Indian people in particular and developing countries in general.
Bleeding Hosts and their Contact Relics in Late Medieval Northern Germany
Authors: Bynum Caroline W.
Published: March 2005

About 100 cases of bleeding host miracles have been reported for Germany between 1300 and 1550. Received opinion asserts that these are Bavarian and overwhelmingly anti-Semitic. In fact there are a number of northern German cases, not all of them anti-Jewish libels. In several of these cases not only the miraculous hosts but also objects associated with them were displayed in churches, and some of the associated objects (cooking pots, nails, etc.) survived the Reformation, during which the hosts themselves were destroyed. Exploring several cases in which such associated objects figured prominently, this article suggests a number of reasons why they survived, and argues that their survival sheds light on the late medieval desire for, and ambivalence about, ‘holy matter.’
Salient Features of Chinese Historical Thinking
Authors: Huang Chun-chieh
Published: March 2005

In this article I argue that history occupies pivotal position in the world-view and philosophy of life in the Chinese tradition. Chinese civilisation is deeply imbued with historical consciousness and its people are homo historiens in every sense. Historical thinking in traditional China is infused with a moral meaning. The notion of dao, that is, heavenly principle and human norm, stands at the centre of this consciousness. In view of its practical operation, Chinese historical thinking is on one hand concrete, and on the other, analogical; it enables communication with the past and extrapolation of meanings from history. In this way, historical experience in China becomes a library where contemporary readers may engage in creative dialogues with the past.
‘Divine Semen’ and the Alchemical Conversion of Iramatevar
Authors: Natarajan Kanchana
Published: March 2005

This article is a biographical study of the alchemist and tantrik siddha Iramatevar alias Yakoppu based on his original work in medieval Tamil. In the arduous process of knowledge acquisition and production Yakoppu took the remarkable step of visiting Mecca and converting to Islam. He was a prolific writer and in many works describes the imperative and mechanism of the realigning of his personal identity in fascinating detail. The intrepid persona of Iramatevar or Yakoppu is not a simple juxta-position of two traditions, Hinduism and Islam, but a veritable alchemical symbiosis.
Social and Dietary Changes Associated with Obesity and Breast Cancer Risk
Authors: Selvan Mano S. , Wilkinson Anna V. , Chamberlain Robert , Bondy Melissa L.
Published: March 2005

Women’s dietary behaviour and physical activity have changed as they have entered the workplace in developed and developing countries around the world. Women now manage dual roles, one at work and one at home, resulting in less time for traditional meal preparation and housekeeping, and hence less physical activity. Technological innovations such as kitchen gadgets and other labour-saving devices have also eliminated much of the strenuous physical activity associated with performing household chores. As a result of these social changes, there has been a transition in dietary behaviour and physical activity. Specifically, many women now lead more sedentary lifestyles and eat higher calorie diets than ever before, which in turn is fuelling the obesity epidemic—one of the risk factors for many diseases, such as diabetes and probably breast cancer, now one of the most prevalent cancers among women. This paper describes the epidemiology of breast cancer and the probable role of physical inactivity, diet and obesity in its development.
The Role of International Trade Policy in Economic Growth: A Case of Tanzania
Authors: Harris Curt J. , Kulkarni Kishore G.
Published: March 2005

While the benefits from international trade are well documented in economic literature, application of a prudent trade policy may need a political acumen as well as economic insight. Tanzania has been a classic example of how a strategic trade policy can affect economic growth in a positive way. This paper analyzes the economic effects of tariff policy and by discussing the background of Tanzania economy it applies the theoretical principles to this specific case.
A Scalable Strategy for the Parallelization of Multiphysics Unstructured Mesh-Iterative Codes on Distributed-Memory Systems
Authors: McManus Kevin , Cross Mark , Walshaw Chris , Johnson Steve , Leggett Peter
Published: March 2005

Realizing scalable performance on high performance computing systems is not straightforward for single-phenomenon codes (such as computational fluid dynamics [CFD]). This task is magnified considerably when the target software involves the interactions of a range of phenomena that have distinctive solution procedures involving different discretization methods. The problems of addressing the key issues of retaining data integrity and the ordering of the calculation procedures are significant. A strategy for parallelizing this multiphysics family of codes is described for software exploiting finite-volume discretization methods on unstructured meshes using iterative solution procedures. A mesh partitioning-based SPMD approach is used. However, since different variables use distinct discretization schemes, this means that distinct partitions are required; techniques for addressing this issue are described using the mesh-partitioning tool, JOSTLE. In this contribution, the strategy is tested for a variety of test cases under a wide range of conditions (e.g., problem size, number of processors, asynchronous/synchronous communications, etc.) using a variety of strategies for mapping the mesh partition onto the processor topology.
Pace—A Toolset for the Performance Prediction of Parallel and Distributed Systems
Authors: Nudd G. R. , Kerbyson D. J. , Papaefstathiou E. , Perry S. C. , Harper J. S. , Wilcox D. V.
Published: March 2005

This paper describes a methodology that provides detailed predictive performance information throughout the software design and implementation cycles. It is structured around a hierarchy of performance models that describe the computing system in terms of its software, parallelization, and hardware components. The methodology is illustrated with an implementation, the performance analysis and characterization environment (PACE) system, which provides information concerning execution time, scalability, and resource use. A principal aim of the work is to provide a capability for rapid calculation of relevant performance numbers without sacrificing accuracy. The predictive nature of the approach provides both pre and post implementation analyses and allows implementation alternatives to be explored prior to the commitment of an application to a system. Because of the relatively fast analysis times, these techniques can be used at runtime to assist in application steering and scheduling with reference to dynamically changing systems and metacomputing.
Ligature: Component Architecture for High Performance Applications
Authors: Keahey Katarzyna , Beckman Peter , Ahrens James
Published: March 2005

The increasing feasibility of developing applications spanning nationwide supercomputing resources makes possible the creation of simulations composed of multiple interdisciplinary components and capable of modeling natural and social phenomena of national importance with unprecedented speed and accuracy. However, the potential offered by hardware technology often fails to be fully realized due to the lack of software environments supporting such efforts. Furthermore, the complexity of combining within one application components with different performance characteristics often prevents such applications from achieving required performance levels. The Ligature project at Los Alamos National Laboratory addresses the issue of designing a software infrastructure enabling fast and efficient development of multicomponent applications and that of providing performance guidance to the programmer using this infrastructure. Ligature allows the programmer to define component interfaces specifying how heterogeneous, distributed components can interact within a larger system and provides a reusable infrastructure capable of connecting these components. These interfaces, as well as information about component performance, are accessible through a database. Within this framework, we are trying to understand how information about the performance of individual components and information about performance of the framework can be combined to develop a performance-aware multicomponent application.
The Dynamics of Performance Collapse in Large-Scale Networks and Computers
Authors: Gunther Neil J.
Published: March 2005

Failures in communication networks have become all too familiar. The AT&T phone system was brought to its knees in 1990 and their frame-relay network shut down west coast bank ATMs in 1998. These were hard network failures. Less obvious is the congestive failure of packet networks even without hard errors. This spontaneous collapse in performance is observed as orders-of-magnitude drop in packets/second delivered or increased packet delay. Such effects were seen on the Internet in 1986 and led to the implementation of the TCP/IP “slow-start” congestion avoidance algorithm. That same algorithm is now responsible for latency overhead in HTTP traffic on the World Wide Web. This paper outlines an approach developed by the author based on the surprising observation that the degree of instability in computer networks is logically equivalent to estimating the rate of decay in an unstable (radioactive) atom and suggests the application of the Feynman path integral from quantum mechanics. The advantage of this approach is threefold: (a) it makes the dynamics of large transients intuitively clear, (b) it furnishes an estimator for the mean time to collapse, and (c) it provides corrections to other estimators (e.g., Catastrophe Theory and the Theory of Large Deviations).
New Software Technologies for the Development and Runtime Support of Complex Applications
Authors: Darema Frederica
Published: March 2005

This paper discusses new research directions leading to novel software technologies for the development and runtime support of complex applications executing on dynamic and adaptive computing platforms. The two key technology areas discussed here are new compiling technology and new application composition technology, which will enable applications to effectively exploit such platforms. In the new compiling system advocated here, a tight interaction loop is enabled between the compiler and the underlying system resource managers, as well as performance descriptors of the applications and the underlying hardware and software systems. This kind of new compiling system will have the ability to adaptively optimize the mapping of applications on the underlying dynamic platform assembly. In addition, the paper discusses the need for new technology for knowledge-based, compiler-invoked application components’ dynamic assembly. Together with such advances, new programming models that can aid the new compiling system in the tasks above are also necessary. The paper also addresses the need for integration of these technologies into application support environments and demonstration of the technologies on important production-class applications.
High-Performance Computational Chemistry: Hartree-Fock Electronic Structure Calculations on Massively Parallel Processors
Authors: Tilson Jeffrey L. , Minkoff Mike , Wagner Albert F. , Shepard Ron , Sutton Paul , Harrison Robert J. , Kendall Ricky A. , Wong Adrian T.
Published: March 2005

The parallel performance of the NWChem version 1.2α parallel direct-SCF code has been characterized on five massively parallel supercomputers (IBM SP, Kendall Square KSR-2, CRAY T3D and T3E, and Intel Touchstone DELTA) using single-point energy calculations on seven molecules of varying size (up to 389 atoms) and composition (first-row atoms, halogens, and transition metals). The authors compare the performance using both replicated-data and distributed-data algorithms and the original McMurchie-Davidson and recently incorporated TEXAS integrals packages.
Examining Delinquent Nongang Members and Delinquent Gang Members
Authors: Schram Pamela J. , Gaines Larry K.
Published: March 2005

This study examines differences between juvenile gang and nongang members participating in a juvenile probation program designed to identify and intervene with youth considered to be high risk for subsequent criminal and delinquent activity. After participating in the Multidisciplinary Team Program, both gang and nongang members significantly improved their grade point average, lowered the number of classes missed, and reduced the number of suspensions. Both groups also improved on family functioning and a decrease in reported alcohol and substance abuse. There were also improvements for gang and nongang members concerning subsequent delinquent activity. The results suggest that at some levels, gang affiliation is not an impediment to treatment programming. A limitation to the study was that gang membership was based on self-report and law enforcement identification, which results in false positive and false negative designations. Additionally, the nongang group may have included youths who escaped being identified as gang members.
Could flies explain the elusive epidemiology of campylobacteriosis?
Authors: Ekdahl Karl , Normann Bengt , Andersson Yvonne
Published: March 2005

Background

Unlike salmonellosis with well-known routes of transmission, the epidemiology of campylobacteriosis is still largely unclear. Known risk factors such as ingestion of contaminated food and water, direct contact with infected animals and outdoor swimming could at most only explain half the recorded cases.

Discussion

We put forward the hypothesis that flies play a more important role in the transmission of the bacteria, than has previously been recognized. Factors supporting this hypothesis are: 1) the low infective dose of Campylobacter; 2) the ability of flies to function as mechanical vectors; 3) a ubiquitous presence of the bacteria in the environment; 4) a seasonality of the disease with summer peaks in temperate regions and a more evenly distribution over the year in the tropics; 5) an age pattern for campylobacteriosis in western travellers to the tropics suggesting other routes of transmission than food or water; and finally 6) very few family clusters.

All the evidence in favour of the fly hypothesis is circumstantial and there may be alternative explanations to each of the findings supporting the hypothesis. However, in the absence of alternative explanations that could give better clues to the evasive epidemiology of Campylobacter infection, we believe it would be unwise to rule out flies as important mechanical vectors also of this disease.
Duration of streptozotocin-induced diabetes differentially affects p38-mitogen-activated protein kinase (MAPK) phosphorylation in renal and vascular dysfunction
Authors: Chen Hongmei , Brahmbhatt Sachin , Gupta Akanksha , Sharma Avadhesh C
Published: March 2005

Background

In the present study we tested the hypothesis that progression of streptozotocin (STZ)-induced diabetes (14-days to 28-days) would produce renal and vascular dysfunction that correlate with altered p38- mitogen-activated protein kinase (p38-MAPK) phosphorylation in kidneys and thoracic aorta.

Methods

Male Sprague Dawley rats (350–400 g) were randomized into three groups: sham (N = 6), 14-days diabetic (N = 6) and 28-days diabetic rats (N = 6). Diabetes was induced using a single tail vein injection of STZ (60 mg/kg, I.V.) on the first day. Rats were monitored for 28 days and food, water intake and plasma glucose levels were noted. At both 14-days and 28-days post diabetes blood samples were collected and kidney cortex, medulla and aorta were harvested from each rat.

Results

The diabetic rats lost body weight at both 14-days (-10%) and 28-days (-13%) more significantly as compared to sham (+10%) group. Glucose levels were significantly elevated in the diabetic rats at both 14-days and 28-days post-STZ administration. Renal dysfunction as evidenced by renal hypertrophy, increased plasma creatinine concentration and reduced renal blood flow was observed in 14-days and 28-days diabetes. Vascular dysfunction as evidenced by decreased carotid blood flow was observed in 14-days and 28-days diabetes. We observed an up-regulation of inducible nitric oxide synthase (iNOS), prepro endothelin-1 (preproET-1) and phosphorylated p38-MAPK in thoracic aorta and kidney cortex but not in kidney medulla in 28-days diabetes group.

Conclusion

The study provides evidence that diabetes produces vascular and renal dysfunction with a profound effect on signaling mechanisms at later stage of diabetes.