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At least 685 records · Page 38Linked to original sources
PubMed1996

[An international exchange and dissemination of chemical safety information on the Internet].

An information system for chemical safety has been developed on the National Institute of Health Sciences (NIHS) Information and Computing Infrastructure. The system is based on client server systems on the local area network (LAN) connected to the Internet. A wide range of safety information for chemicals including foods, food additives, household goods, industrial chemicals and environmental pollutants were collected and put on the World Wide Web (WWW) server and the database management system, Sybase. In addition to original information contents, the System has links to many useful Web sites so that it functions as a global hub for chemical safety information.

Agrochemicals↗
PubMed1997

[Observations on social medicine in public health transition].

In spite of the growing criticism of the social welfare principles, the social health insurance model is remarkably stable in Europe. Key features of this model are even implemented in more market oriented models (as in Switzerland) and in national health systems as in the United Kingdom. In Germany, however, the discussion is almost solely centred around the argument of globalisation of capital and labour and, subsequently, the high additional costs on labour. This endangers social security which is financed through wages. If the social welfare system in Germany would be abolished de facto and not intelligently adapted, this would be a dramatic signal against social principles all over Europe. Consequences for social medicine as a scientific discipline are: Social medicine as a public health discipline with the goal of equality in health care must get involved in health politics. Social medicine as an empirical science has to evaluate- and refute, if necessary-existing myths and prejudices. Social medicine needs a stable network for research, teaching and practice-this is the growing field of "public health".

Cost Control↗
PubMed2004

Pivotal role of Gly 121 in dihydrofolate reductase from Escherichia coli: the altered structure of a mutant enzyme may form the basis of its diminished catalytic performance.

The structure and folding of dihydrofolate reductase (DHFR) from Escherichia coli and the mutant G121V-DHFR, in which glycine 121 in the exterior FG loop was replaced with valine, were studied by molecular dynamics simulations and CD and fluorescence spectroscopy. The importance of residue 121 for the chemical step during DHFR catalysis had been demonstrated previously. High-temperature MD simulations indicated that while DHFR and G121V-DHFR followed similar unfolding pathways, the strong contacts between the M20 loop and the FG loop in DHFR were less stable in the mutant. These contacts have been proposed to be involved in a coupled network of interactions that influence the protein dynamics and promote catalysis [Benkovic, S. J., and Hammes-Schiffer, S. (2003) Science 301, 1196-1202]. CD spectroscopy of DHFR and G121V-DHFR indicated that the two proteins existed in different conformations at room temperature. While the thermally induced unfolding of DHFR was highly cooperative with a midpoint at 51.6 +/- 0.7 degrees C, G121V-DHFR exhibited a gradual decrease in its level of secondary structure without a clear melting temperature. Temperature-induced unfolding and renaturation from the urea-denatured state revealed that both proteins folded via highly fluorescent intermediates. The formation of these intermediates occurred with relaxation times of 149 +/- 4.5 and 256 +/- 13 ms for DHFR and G121V-DHFR, respectively. The fluorescence intensity for the intermediates formed during refolding of G121V-DHFR was approximately twice that of the wild-type. While the fluorescence intensity then slowly decayed for DHFR toward a state representing the native protein, G121V-DHFR appeared to be trapped in a highly fluorescent state. These results suggest that the reduced catalytic activity of G121V-DHFR is the consequence of nonlocal structural effects that may result in a perturbation of the network of promoting motions.

Catalysis↗
PubMed2001

Glistening formation in an AcrySof lens initiated by spinodal decomposition of the polymer network by temperature change.

PURPOSE: To examine the effect of temperature change on the structural alteration and glistening formation in an AcrySof intraocular lens (IOL). SETTING: Department of Chemical Science and Engineering, Faculty of Engineering, Kobe University, Kobe, Japan. METHODS: The equilibrium water content of a Wagon-Wheel-packaged AcrySof IOL was determined at various temperatures by the gravimetrical method. Alterations in the microscopic structure of the lens were analyzed in situ with a reflecting microscope without staining, while the temperature of the lens was changed at different rates. RESULTS: Microvacuoles of 1.0 to 20.0 microm formed in the bulk of a swollen AcrySof IOL as the temperature decreased. The morphology of the vacuoles was similar to that of glistening particles observed in vivo. The size and density of the glistening-like vacuoles varied depending on the magnitude and rate of the temperature decrease. The glistening-like vacuoles were imprinted in the bulk of the IOL during the preceding cooling process in aqueous humor. CONCLUSIONS: Glistenings formed in the bulk of an AcrySof IOL as the medium temperature decreased. The mechanism may involve spinodal decomposition of the swollen polymer network, which initiates the formation of microvacuoles consisting of water and loosely packed network chains.

Acrylic Resins↗
PubMed1993

The need to protect patients' rights.

This article addresses the need to protect patients' rights against the backdrop of the influence of institutions of health, the industry of diagnostic and therapeutic weapons, advances in science and the interests of third parties in the patient's state of health. What is required is setting up and sorting out a health care providers' network, regulating the relations concerning the economic activities of health care providers and determining the participation of health care providers in primary prevention and curative care.

Health Services Accessibility↗
PubMed2005

[The sciences and education in museums at the close of the nineteenth century].

In the closing decades of the nineteenth century, natural history museums established solid communication networks, and their different audiences formed what became known as the 'museum movement'. It was within this context of exchange that William H. Flower made his 1889 speech on the roles natural history museums should play. The article analyzes his influence on Argentina's Museo da La Plata, a member of this then-expanding circuit of museums.

Argentina↗
PubMed1981

Computer-assisted instruction in a health sciences library: an experimental project.

The Leon S. McGoogan Library of Medicine at the University of Nebraska received a grant from the University of Nebraska Computer Network to study management aspects of providing computer-assisted instruction (CAI) resources. The library wished to determine: (1) faculty and student receptiveness to CAI as a library resource and (2) user response to CAI library services. A user questionnaire was designed to ascertain the appropriateness of initial management decisions regarding CAI access. The methodology employed in implementing this pilot project, the results of the questionnaire, and the future of CAI at the University of Nebraska are addressed in this paper.

Computer-Assisted Instruction↗
PubMed2005

European plant science: a field of opportunities.

Plants have a pivotal role in eco- and agricultural systems. Genomics is driving a rapid expansion of our understanding of how genes, individually and in networks, determine plant function. Technological developments in breeding and genomics are providing strategies to translate this knowledge into crop improvement. The possibilities range from improvement of existing crops and the systematic use of natural diversity through to the domestication of completely new species. As examples of possible goals, it is discussed how profiling of composition will integrate plant breeding and agronomic practice with emerging knowledge about nutrition and health, how improved and novel crops will contribute to the creation of new bio-based economies revolving around plant products, and how advances in our knowledge about plant-environment and plant-pathogen interactions will provide novel strategies to stabilize agricultural yield in a fluctuating environment and contribute to integrated approaches in which modern agriculture is carried out in concert with the environment. In addition, knowledge generated by plant science will be needed to monitor, understand, and cope with climate change and its impact on agriculture and ecosystems. Realization of these goals will require close interactions with related disciplines including agronomy and ecology. Further, it will be important to continue and deepen open support for research in the developing world.

Agriculture↗
PubMed1996

First use of cognitive algorithms in investigations under compensated gravity.

In the present paper the use of cognitive algorithms for solving a wide spectrum of problems which often arise in investigations under compensated gravity is suggested. Applying such algorithms in the preparation and performance of experiments provides a substantial assistance to the experimentator as the behaviour of complex processes can be described and predicted correctly even when unexpected perturbations occur. Furthermore, an essential advantage of cognitive computing consists in the fact that the description and optimisation of the processes considered are possible also in such cases in which the corresponding basic equations are not known or not treatable practically. For convenience, the basic ideas of cognitive algorithms are discussed here. Due to their special relevance for investigations under compensated gravity algorithms based on fuzzy logic (FL) and artificial neuronal networks (ANN) are elucidated more in detail. In order to illustrate some advantages of cognitive computing exemplary results for the flow field induced by coaxial rotating disks are given. This represents the first attempt to use the benefits provided by cognitive algorithms in investigations under compensated gravity. The flow field between rotating disks plays an important role not only in experiments under compensated gravity but also in a wide range of terrestrial applications. A comparison of the results found by solving the Navier-Stokes equations and those from the prediction performed by ANN adequately trained shows an excellent agreement. However, the calculation times needed by the ANN are significantly smaller than that of the direct numerical simulation. Therefore, the real time prediction of the results from a running experiment seems to be possible.

Algorithms↗
PubMed2001

Emerging paradigms in mind-body medicine.

The emerging paradigms in medicine can be seen through mind-body interactions. Observations in many meditative traditions suggest a series of objective indicators of health beyond absence of disease. Several of the physical signs have been confirmed by research or are consistent with modern science. Further correlation with long term health outcome is needed. Integration of meditation with conventional therapy has enriched psychotherapy with parallels drawn between the Nine Step Qigong and Freudian developmental psychology. A unified theory of the chakra system and the meridian system widely used in traditional mind-body interventions and acupuncture is presented in terms of modern science based on the morphogenetic singularity theory. Acupuncture points originate from the organizing centers in morphogenesis. Meridians and chakras are related to the underdifferentiated, interconnected cellular network that regulates growth and physiology. This theory explains the distribution and nonspecific activation of organizing centers and acupuncture points; the high electric conductance of the meridian system; the polarity effect of electroacupuncture; the side-effect profile of acupuncture; and the ontogeny, phylogeny, and physiologic function of the meridian system and chakra system. It also successfully predicted several findings in conventional biomedical science. These advances have implications in many disciplines of medicine.

Breathing Exercises↗
PubMedDate not supplied

A trajectory-preserving synchronization method for collaborative visualization.

In the past decade, a lot of research work has been conducted to support collaborative visualization among remote users over the networks, allowing them to visualize and manipulate shared data for problem solving. There are many applications of collaborative visualization, such as oceanography, meteorology and medical science. To facilitate user interaction, a critical system requirement for collaborative visualization is to ensure that remote users will perceive a synchronized view of the shared data. Failing this requirement, the user's ability in performing the desirable collaborative tasks will be affected. In this paper, we propose a synchronization method to support collaborative visualization. It considers how interaction with dynamic objects is perceived by application participants under the existence of network latency, and remedies the motion trajectory of the dynamic objects. It also handles the false positive and false negative collision detection problems. The new method is particularly well designed for handling content changes due to unpredictable user interventions or object collisions. We demonstrate the effectiveness of our method through a number of experiments.

Journal Article↗
PubMed2003

Rethinking Big Science. Modest, mezzo, grand science and the development of the Bevalac, 1971-1993.

Historians of science have tended to focus exclusively on scale in investigations of largescale research, perhaps because it has been easy to assume that comprehending a phenomenon dubbed "Big Science" hinges on an understanding of bigness. A close look at Lawrence Berkeley Laboratory's Bevalac, a medium-scale "mezzo science" project formed by uniting two preexisting machines--the modest SuperHILAC and the grand Bevatron--shows what can be gained by overcoming this preoccupation with bigness. The Bevalac story reveals how interconnections, connections, and disconnections ultimately led to the development of a new kind of science that transformed the landscape of large-scale research in the United States. Important lessons in historiography also emerge: the value of framing discussions in terms of networks, the necessity of constantly expanding and refining methodology, and the importance of avoiding the rhetoric of participants and instead finding words to tell our own stories.

California↗
PubMed2005

Modelling biological complexity: a physical scientist's perspective.

We discuss the modern approaches of complexity and self-organization to understanding dynamical systems and how these concepts can inform current interest in systems biology. From the perspective of a physical scientist, it is especially interesting to examine how the differing weights given to philosophies of science in the physical and biological sciences impact the application of the study of complexity. We briefly describe how the dynamics of the heart and circadian rhythms, canonical examples of systems biology, are modelled by sets of nonlinear coupled differential equations, which have to be solved numerically. A major difficulty with this approach is that all the parameters within these equations are not usually known. Coupled models that include biomolecular detail could help solve this problem. Coupling models across large ranges of length- and time-scales is central to describing complex systems and therefore to biology. Such coupling may be performed in at least two different ways, which we refer to as hierarchical and hybrid multiscale modelling. While limited progress has been made in the former case, the latter is only beginning to be addressed systematically. These modelling methods are expected to bring numerous benefits to biology, for example, the properties of a system could be studied over a wider range of length- and time-scales, a key aim of systems biology. Multiscale models couple behaviour at the molecular biological level to that at the cellular level, thereby providing a route for calculating many unknown parameters as well as investigating the effects at, for example, the cellular level, of small changes at the biomolecular level, such as a genetic mutation or the presence of a drug. The modelling and simulation of biomolecular systems is itself very computationally intensive; we describe a recently developed hybrid continuum-molecular model, HybridMD, and its associated molecular insertion algorithm, which point the way towards the integration of molecular and more coarse-grained representations of matter. The scope of such integrative approaches to complex systems research is circumscribed by the computational resources available. Computational grids should provide a step jump in the scale of these resources; we describe the tools that RealityGrid, a major UK e-Science project, has developed together with our experience of deploying complex models on nascent grids. We also discuss the prospects for mathematical approaches to reducing the dimensionality of complex networks in the search for universal systems-level properties, illustrating our approach with a description of the origin of life according to the RNA world view.

Animals↗
PubMed1991

Prevention of stroke--a report from collaboration project between Zagreb and Barcelona.

Cerebrovascular disease (CVD) is the main killer in the modern society and the most frequent cause of death and disability. According to the experiences of highly developed Western countries, especially of the U.S.A., the incidence of stroke can be reduced by the development and introduction of preventive actions and change of life style. Incidence of cerebrovascular disease is high in Croatia as well as in Spain (46% in the 46-59 age range) with an increasing tendency in younger population. As prevention is the only way of CVD incidence reduction, it is indispensable to organize an integral preventive neurologic network. Within the W.H.O. project "Health for All by the Year 2000 and the project "Zagreb"--Healthy City" a preventive action under the slogan 'With perfect brain and veins--enjoy the healthy days', has been organized with the aim to reduce the incidence of stroke for 20% during the following 10-year period. A standardized work of preventive network in Zagreb has also been established in Barcelona as a joint work. Using the interdisciplinary counselling approach, medical teams are still making examinations. In Zagreb Center for Neurological Sciences and Brain Research, data of risk factor distributions and trends of stroke incidence changes have been collected and the results have been analyzed. The Zagreb Center has also become a center for continuous evaluation and further planning. In this article functions of preventive centers, the preventive standardized protocol and structural and functional preventive network are introduced. The results of preventive action in Zagreb are also briefly presented.

Aged↗
PubMed1999

Attractor neural network models of spatial maps in hippocampus.

Hippocampal pyramidal neurons in rats are selectively activated at specific locations in an environment (O'Keefe and Dostrovsky, Brain Res 1971;34:171-175). Different cells are active in different places, therefore providing a faithful representation of the environment in which every spatial location is mapped to a particular population state of activity of place cells (Wilson and McNaughton, Science 1993;261:1055-1058; Zhang et al., J Neurosci 1998;79:1017-1044). We describe a theory of the hippocampus, according to which the map results from the cooperative dynamics of network, in which the strength of synaptic interaction between the neurons depends on the distance between their place fields. This synaptic structure guarantees that the network possesses a quasi-continuous set of stable states (attractors) that are localized in the space of neuronal variables reflecting their synaptic interactions, rather than their physical location in the hippocampus. As a consequence of the stable states, the network can exhibit place selective activity even without relying on input from external sensory cues.

Animals↗
PubMed1994

Global information infrastructure.

The High Performance Computing and Communications Program (HPCC) is a multiagency federal initiative under the leadership of the White House Office of Science and Technology Policy, established by the High Performance Computing Act of 1991. It has been assigned a critical role in supporting the international collaboration essential to science and to health care. Goals of the HPCC are to extend USA leadership in high performance computing and networking technologies; to improve technology transfer for economic competitiveness, education, and national security; and to provide a key part of the foundation for the National Information Infrastructure. The first component of the National Institutes of Health to participate in the HPCC, the National Library of Medicine (NLM), recently issued a solicitation for proposals to address a range of issues, from privacy to 'testbed' networks, 'virtual reality,' and more. These efforts will build upon the NLM's extensive outreach program and other initiatives, including the Unified Medical Language System (UMLS), MEDLARS, and Grateful Med. New Internet search tools are emerging, such as Gopher and 'Knowbots'. Medicine will succeed in developing future intelligent agents to assist in utilizing computer networks. Our ability to serve patients is so often restricted by lack of information and knowledge at the time and place of medical decision-making. The new technologies, properly employed, will also greatly enhance our ability to serve the patient.

Computer Communication Networks↗
PubMed1997

Simplex Memory Neural Networks.

The biological neural network-simplex memory neural network-is proposed to describe the mechanisms of pattern memory in the brain. A mathematical model of the simplex memory neural network is constructed to memorize any binary pattern with content-addressable memory function. Under Hebbian learning rule, the new network has some important functions in accord with the learning and memory behaviors of the brain. Copyright 1996 Elsevier Science Ltd.

Journal Article↗