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At least 1,027 records · Page 57Linked to original sources
PubMed1997

Critique of the National Cancer Institute of Canada's framework for cancer control.

This paper offers a critique of the National Cancer Institute of Canada's (NCIC) framework for cancer control. The critique has been prepared by researchers who used the framework to review the literature in 5 substantive areas. These reviews, published in the current and previous issues of CPC, were designed to begin to outline a research agenda for the Sociobehavioural Cancer Research Network. In this paper, the authors reflect on the strengths and limitations of the framework. Perceived strengths are that the framework (a) facilitates systematic thinking about research options and priorities, (b) helps foster clear communication, (c) links science and practice, (d) may assist grant review panels to place proposed studies in context and (e) emphasizes important values. Perceived concerns include the following: (a) potential users are not familiar with the framework, (b) lack of clarity of definitions and classification criteria, (c) the utility of the framework is not immediately self-evident to potential users, (d) the framework lacks emphasis on environmental and policy interventions and (e) it is not clear how the values espoused are to be integrated with other dimensions of the framework. The concerns were seen as remediable. In short, the framework was seen to be valuable in its current form; refinement may enhance its value.

Canada↗
PubMed2006

Deterministic modelling and stochastic simulation of biochemical pathways using MATLAB.

The analysis of complex biochemical networks is conducted in two popular conceptual frameworks for modelling. The deterministic approach requires the solution of ordinary differential equations (ODEs, reaction rate equations) with concentrations as continuous state variables. The stochastic approach involves the simulation of differential-difference equations (chemical master equations, CMEs) with probabilities as variables. This is to generate counts of molecules for chemical species as realisations of random variables drawn from the probability distribution described by the CMEs. Although there are numerous tools available, many of them free, the modelling and simulation environment MATLAB is widely used in the physical and engineering sciences. We describe a collection of MATLAB functions to construct and solve ODEs for deterministic simulation and to implement realisations of CMEs for stochastic simulation using advanced MATLAB coding (Release 14). The program was successfully applied to pathway models from the literature for both cases. The results were compared to implementations using alternative tools for dynamic modelling and simulation of biochemical networks. The aim is to provide a concise set of MATLAB functions that encourage the experimentation with systems biology models. All the script files are available from www.sbi.uni-rostock.de/ publications_matlab-paper.html.

Biochemistry↗
PubMed2004

Searching for intellectual turning points: progressive knowledge domain visualization.

This article introduces a previously undescribed method progressively visualizing the evolution of a knowledge domain's cocitation network. The method first derives a sequence of cocitation networks from a series of equal-length time interval slices. These time-registered networks are merged and visualized in a panoramic view in such a way that intellectually significant articles can be identified based on their visually salient features. The method is applied to a cocitation study of the superstring field in theoretical physics. The study focuses on the search of articles that triggered two superstring revolutions. Visually salient nodes in the panoramic view are identified, and the nature of their intellectual contributions is validated by leading scientists in the field. The analysis has demonstrated that a search for intellectual turning points can be narrowed down to visually salient nodes in the visualized network. The method provides a promising way to simplify otherwise cognitively demanding tasks to a search for landmarks, pivots, and hubs.

Internet↗
PubMed1999

CME in primary care: the way forward.

The paper aims to describe the context for future continuing medical education (CME) in primary care. CME must develop the doctor's ability to look at diseases from a scientifically-based biomedical, psychological, and social perspective. It is a challenge for CME to bridge the gap between scientific evidence, and doctors' knowledge, attitude, and performance, but awareness on how to do this is scarce. CME must be better integrated with quality development, especially with the use of clinical guidelines. This is impeded by insufficient scientific evidence on the impact, advantages, and disadvantages of different CME methods, and by insufficient outcome measures of the effect of CME. Teaching the teachers should also be improved. It is concluded that the time is ripe for a scientific-based development in the conduction of CME. This may be done by establishing national research centres for CME, working together in an international network.

Certification↗
PubMed2002

Computationally intensive econometrics using a distributed matrix-programming language.

This paper reviews the need for powerful computing facilities in econometrics, focusing on concrete problems which arise in financial economics and in macroeconomics. We argue that the profession is being held back by the lack of easy-to-use generic software which is able to exploit the availability of cheap clusters of distributed computers. Our response is to extend, in a number of directions, the well-known matrix-programming interpreted language Ox developed by the first author. We note three possible levels of extensions: (i) Ox with parallelization explicit in the Ox code; (ii) Ox with a parallelized run-time library; and (iii) Ox with a parallelized interpreter. This paper studies and implements the first case, emphasizing the need for deterministic computing in science. We give examples in the context of financial economics and time-series modelling.

Computer Communication Networks↗
PubMed1995

Building and maintaining a library Gopher: traditional skills applied to emerging resources.

Gopher software has emerged rapidly as a powerful tool for providing library users with organized access to Internet resources. Building and maintaining Gophers is one way in which librarians' traditional knowledge and skills are being applied in a nontraditional area. In March 1992, the University of Michigan's ULibrary Gopher was created, mainly as a means of providing access to U.S. Census data and the U.S. Department of Commerce's Economic Bulletin Board. In an effort to broaden the scope of the Gopher, librarians were asked to submit ideas for new resources to access. The result was the ULibrary Gopher Working Group, a team of eighteen librarians from six libraries on campus. The Alfred Taubman Medical Library staff drafted a menu design for life sciences resources and received basic UNIX training. In March 1993, the life sciences section of ULibrary became fully operational and now is maintained by the Taubman staff. This paper describes the history of the ULibrary Gopher and the working group, the creation and ongoing maintenance of the life sciences area of the Gopher, staffing issues, and the relationship of Gopher building to traditional collection development.

Computer Communication Networks↗
PubMed1996

Characterization of a Class of Sigmoid Functions with Applications to Neural Networks.

We study two classes of sigmoids: the simple sigmoids, defined to be odd, asymptotically bounded, completely monotone functions in one variable, and the hyperbolic sigmoids, a proper subset of simple sigmoids and a natural generalization of the hyperbolic tangent. We obtain a complete characterization for the inverses of hyperbolic sigmoids using Euler's incomplete beta functions, and describe composition rules that illustrate how such functions may be synthesized from others. These results are applied to two problems. First we show that with respect to simple sigmoids the continuous Cohen-Grossberg-Hopfield model can be reduced to the (associated) Legendre differential equations. Second, we show that the effect of using simple sigmoids as node transfer functions in a one-hidden layer feedforward network with one summing output may be interpreted as representing the output function as a Fourier series sine transform evaluated at the hidden layer node inputs, thus extending and complementing earlier results in this area. Copyright 1996 Elsevier Science Ltd

Journal Article↗
PubMed2005

Bacteriophage endolysins--current state of research and applications.

Endolysins are phage-encoded enzymes that break down bacterial peptidoglycan at the terminal stage of the phage reproduction cycle. Their action is tightly regulated by holins, by membrane arrest, and by conversion from their inactive to active state. Recent research has not only revealed the unexpected diversity of these highly specific hydrolases but has also yielded insights into their modular organization and their three-dimensional structures. Their N-terminal catalytic domains are able to target almost every possible bond in the peptidoglycan network, and their corresponding C-terminal cell wall binding domains target the enzymes to their substrate. Owing to their specificity and high activity, endolysins have been employed for various in vitro and in vivo aims, in food science, in microbial diagnostics, and for treatment of experimental infections. Clearly, phage endolysins represent great tools for use in molecular biology, biotechnology and in medicine, and we are just beginning to tap this potential.

Bacteriolysis↗
PubMed1996

Order of Search in Fuzzy ART and Fuzzy ARTMAP: Effect of the Choice Parameter.

This paper focuses on two ART architectures, the Fuzzy ART and the Fuzzy ARTMAP. Fuzzy ART is a pattern clustering machine, while Fuzzy ARTMAP is a pattern classification machine. Our study concentrates on the order according to which categories in Fuzzy ART, or the ART(a) model of Fuzzy ARTMAP are chosen. Our work provides a geometrical, and clearer understanding of why, and in what order, these categories are chosen for various ranges of the choice parameter of the Fuzzy ART module. This understanding serves as a powerful tool in developing properties of learning pertaining to these neural network architectures; to strengthen this argument, it is worth mentioning that the order according to which categories are chosen in ART 1 and ARTMAP provided a valuable tool in proving important properties about these architectures. Copyright 1996 Elsevier Science Ltd.

Journal Article↗
PubMed1997

SCAN: A Scalable Model of Attentional Selection.

This paper describes the SCAN (Signal Channelling Attentional Network) model, a scalable neural network model for attentional scanning. The building block of SCAN is a gating lattice, a sparsely-connected neural network defined as a special case of the Ising lattice from statistical mechanics. The process of spatial selection through covert attention is interpreted as a biological solution to the problem of translation-invariant pattern processing. In SCAN, a sequence of pattern translations combines active selection with translation-invariant processing. Selected patterns are channelled through a gating network, formed by a hierarchical fractal structure of gating lattices, and mapped onto an output window. We show how the incorporation of an expectation-generating classifier network (e.g. Carpenter and Grossberg's ART network) into SCAN allows attentional selection to be driven by expectation. Simulation studies show the SCAN model to be capable of attending and identifying object patterns that are part of a realistically sized natural image. Copyright 1997 Elsevier Science Ltd.

Journal Article↗
PubMed1999

[Information technology in medical education].

The role of information technology in educational models of under-graduate and post-graduate medical education is growing in 1980's influenced by PC's break-in in medical practice and creating relevant data basis, and, particularly, in 1990's by integration of information technology on international level, development of international network, Internet, Telemedicin, etc. The development of new educational information technology is evident, proving that information in transfer of medical knowledge, medical informatics and communication systems represent the base of medical practice, medical education and research in medical sciences. In relation to the traditional approaches in concept, contents and techniques of medical education, new models of education in training of health professionals, using new information technology, offer a number of benefits, such as: decentralization and access to relevant data sources, collecting and updating of data, multidisciplinary approach in solving problems and effective decision-making, and affirmation of team work within medical and non-medical disciplines. Without regard to the dynamics of change and progressive reform orientation within health sector, the development of modern medical education is inevitable for all systems a in which information technology and available data basis, as a base of effective and scientifically based medical education of health care providers, give guarantees for efficient health care and improvement of health of population.

Bosnia and Herzegovina↗
PubMed2005

Trends in academic health sciences libraries and their emergence as the "knowledge nexus" for their academic health centers.

OBJECTIVES: The objective of this study was to identify trends in academic health sciences libraries (AHSLs) as they adapt to the shift from a print knowledgebase to an increasingly digital knowledgebase. This research was funded by the 2003 David A. Kronick Traveling Fellowship. METHODS: The author spent a day and a half interviewing professional staff at each library. The questionnaire used was sent to the directors of each library in advance of the visit, and the directors picked the staff to be interviewed and set up the schedule. RESULTS: Seven significant trends were identified. These trends are part of the shift of AHSLs from being facility and print oriented with a primary focus on their role as repositories of a print-based knowledgebase to a new focus on their role as the center or "nexus" for the organization, access, and use of an increasingly digital-based knowledgebase. CONCLUSION: This paper calls for a national effort to develop a new model or structure for health sciences libraries to more effectively respond to the challenges of access and use of a digital knowledgebase, much the same way the National Library of Medicine did in the 1960s and 1970s in developing and implementing the National Network of Libraries of Medicine. The paper then concludes with some examples or ideas for research to assist in this process.

Academic Medical Centers↗
PubMedDate not supplied

Help for health decision challenges.

Medical care is becoming more technically challenging and community-based. The majority of patients and family health gatekeepers (the family member who regulates health care services for the family unit) are female, while the majority of physicians are male. Therefore, differences in female versus male methods of decision making add to the difficulty in making health choices. The female patient and family health gatekeeper may need new knowledge, skills and time to help them deal with difficult medical choices. They may benefit from a multidisciplinary, unbiased group of experts in the form of a Community Healthcare Committee. Trained to be responsible for the general health of the community, the primary care practitioner is ideal to take a leadership role in developing such a committee. A Community Healthcare Committee that understands different methods of health decision making could serve as a resource by providing community health education and private case reviews intended to help individuals with health care decisions.

Choice Behavior↗
PubMed1992

Tissue engineering science: consequences of cell traction force.

Blood and tissue cells mechanically interact with soft tissues and tissue-equivalent reconstituted collagen gels in a variety of situations relevant to biomedicine and biotechnology. A key phenomenon in these interactions is the exertion of traction force by cells on local collagen fibers which typically constitute the solid network of these tissues and gels and impart gross mechanical integrity. Two important consequences of cells exerting traction on such collagen networks are first, when the cells co-ordinate their traction, resulting in cell migration, and second, when their traction is sufficient to deform the network. Such cell-collagen network interactions are coupled in a number of ways. Network deformation, for example, can result in net alignment of collagen fibers, eliciting contact guidance, wherein cells move with bidirectional bias along an axis of fiber alignment, potentially leading to a nonuniform cell distribution. This may govern cell accumulation in wounds and be exploited to control cell infiltration of bioartificial tissues and organs. Another consequence of cell traction is the resultant stress and strain in the network which modulate cell protein and DNA synthesis and differentiation. We summarize, here, relevant mathematical theories which we have used to describe the inherent coupling of cell dynamics and tissue mechanics in cell-populated collagen gels via traction. The development of appropriate models based on these theories, in an effort to understand how events in wound healing govern the rate and extent of wound contraction, and to measure cell traction forces in vitro, are described. Relevant observations and speculation from cell biology and medicine that motivate or serve to critique the assumptions made in the theories and models are also summarized.

Biomechanical Phenomena↗
PubMed1993

Application of neural networks to pharmacodynamics.

Neural networks (NN) are computational systems implemented in software or hardware that attempt to simulate the neurological processing abilities of biological systems. A synopsis is presented of the operational characteristics, structures, and applications of NN. The NN technology has primarily been aimed at recognition science (e.g., handwriting, voice, signal, picture, image, pattern, etc.). It is pointed out that NN may also be particularly suitable to deal with pharmacokinetic (PK) and pharmacodynamic (PD) systems, especially in cases such as multivariate PK/PD population kinetics when the systems are so complex that modeling by a conventional structured model building technique is very troublesome. The main practical advantage of NN is the intrinsic ability to closely emulate virtually any multivariate system, including nonlinear systems, independently of structural/physiologic relevance. Thus, NN are most suitable to model the behavior of complex kinetic systems and unsuitable to model the structure. In a practical sense, this structure limitation may be inconsequential because NN in its multivariate formulation may consider any physiologic, clinical, or population variable that may influence the kinetic behavior. The application of NN in PD is demonstrated in terms of the ability of an NN to predict, by extrapolation, the central nervous system (CNS) activity of alfentanil. The drug was infused by a complex computer-controlled infusion scheme over 180 min with simultaneous recording of the CNS effect quantified by a fast Fourier transform power spectrum analysis. The NN was trained to recognize (emulate) the drug input-drug effect behavior of the PD system with the input-effect data for the 180 min as a training set.(ABSTRACT TRUNCATED AT 250 WORDS)

Alfentanil↗
PubMed2003

Symptom experiences of children and adolescents with cancer.

This paper examines nursing research focused on the symptom experiences of children and adolescents with cancer, and the extent to which the perspective and methods of developmental science have been used in this research. CINALH, MEDLINE, and PSYCHLIT were searched for publications between 1990 and 2002. The researcher or research team had to include a nurse or developmentally oriented researchers from other disciplines. Studies focused exclusively on pain were excluded because of recent published reviews. While nurse researchers have contributed influential knowledge related to symptom experiences and symptom distress in children and adolescents with cancer, this research is still in a formative but exciting stage. Two nurse researchers and their teams laid the foundation for this research through their individual studies and collaborative multisite studies. In general, children and adolescents from 10 through 18 years of age were primarily studied; few studies focused on preschool children. Given the fact that these are rare populations, sample sizes were generally small, limiting power and generalizability. Gender, ethnicity, and socioeconomic status were rarely considered in analyses. Most studies used cross-sectional designs, although several included short-term longitudinal or repeated measure designs. To date, longitudinal designs focused on long-term outcomes have not been conducted. There were only a few qualitative studies. There was limited use of conceptual models or theories, and inadequate attention was paid to broader ecological perspectives in the children's lives. Studies included a focus on global symptoms and on individual symptoms, particularly pain and fatigue. Few focused on nausea and vomiting. Operationalization of symptom distress generally involved adapting instruments designed for adults. A more explicit employment of a developmental science perspective in future studies would call for more longitudinal designs that conceptualize the symptom experience from the perspective of the child and that view their responses as complex and multidimensional in nature. This would necessitate measuring clusters of symptoms at multiple levels (e.g., emotional, behavioral, and biophysiological) using developmental data collection methods. Furthermore, attention needs to be paid in conceptualizing studies to ecological factors related to families, social networks, communities, and ethnicity, as well as to the ecology of the health care system, which likely influences the symptom experience of children.

Adolescent↗