Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Networks”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
PubMed2000

Network architectures and circuit function: testing alternative hypotheses in multifunctional networks.

Understanding how species-typical movement patterns are organized in the nervous system is a central question in neurobiology. The current explanations involve 'alphabet' models in which an individual neuron may participate in the circuit for several behaviors but each behavior is specified by a specific neural circuit. However, not all of the well-studied model systems fit the 'alphabet' model. The 'equation' model provides an alternative possibility, whereby a system of parallel motor neurons, each with a unique (but overlapping) field of innervation, can account for the production of stereotyped behavior patterns by variable circuits. That is, it is possible for such patterns to arise as emergent properties of a generalized neural network in the absence of feedback, a simple version of a 'self-organizing' behavioral system. Comparison of systems of identified neurons suggest that the 'alphabet' model may account for most observations where CPGs act to organize motor patterns. Other well-known model systems, involving architectures corresponding to feed-forward neural networks with a hidden layer, may organize patterned behavior in a manner consistent with the 'equation' model. Such architectures are found in the Mauthner and reticulospinal circuits, 'escape' locomotion in cockroaches, CNS control of Aplysia gill, and may also be important in the coordination of sensory information and motor systems in insect mushroom bodies and the vertebrate hippocampus. The hidden layer of such networks may serve as an 'internal representation' of the behavioral state and/or body position of the animal, allowing the animal to fine-tune oriented, or particularly context-sensitive, movements to the prevalent conditions. Experiments designed to distinguish between the two models in cases where they make mutually exclusive predictions provide an opportunity to elucidate the neural mechanisms by which behavior is organized in vivo and in vitro.

Animals↗
PubMed1993

The Hamilton (McMaster) psychiatric network: the evolution of an integrated network of psychiatric services.

For 25 years, the Hamilton-Wentworth region has had a well integrated network of psychiatric services. The initial impetus for its establishment came from the founders of the Department of Psychiatry at McMaster University in 1967. They envisaged a regional network of services that integrated the resources of a community-focused university department with those of local community agencies and other mental health care professionals. Over the years, the evolution of the network has been shaped by changes in the size and composition of the faculty, the emergence of additional clinical services and community programs, new directions in the field of psychiatry and changing economic forces and social values.

Community Mental Health Services↗
PubMed2004

Networks of innovation or networks of opportunity? The making of the Spanish antibiotics industry.

The pharmaceutical industry is a typically research-intensive, first world-industry. This article seeks to explain why it has been so difficult for late industrialised nations to reproduce the networks of innovation on which the design and manufacturing of new drugs has historically based, and why alternative concepts are needed in order to understand the dynamics of science-based industries in emerging countries. The article analyses the development of the Spanish antibiotics industry, build after the World War II under the strong influence of the new international order and Spain's political framework, academic traditions and business groups. Focusing on the long-term relationships established between two Spanish companies (Antibióticos SA and Compañía Española de Penicilina y Antibióticos, CEPA), their American technological partners (Schenley and Merck), and their social and scientific environment, the article identifies networks of opportunity as the key institutional arrangement of this new industry in Spain. Opportunity (as opposed to innovation) networks are thus proposed to conceptualise the development of technologically complex industries in the European periphery.

Anti-Bacterial Agents↗
PubMed2003

Tensegrity II. How structural networks influence cellular information processing networks.

The major challenge in biology today is biocomplexity: the need to explain how cell and tissue behaviors emerge from collective interactions within complex molecular networks. Part I of this two-part article, described a mechanical model of cell structure based on tensegrity architecture that explains how the mechanical behavior of the cell emerges from physical interactions among the different molecular filament systems that form the cytoskeleton. Recent work shows that the cytoskeleton also orients much of the cell's metabolic and signal transduction machinery and that mechanical distortion of cells and the cytoskeleton through cell surface integrin receptors can profoundly affect cell behavior. In particular, gradual variations in this single physical control parameter (cell shape distortion) can switch cells between distinct gene programs (e.g. growth, differentiation and apoptosis), and this process can be viewed as a biological phase transition. Part II of this article covers how combined use of tensegrity and solid-state mechanochemistry by cells may mediate mechanotransduction and facilitate integration of chemical and physical signals that are responsible for control of cell behavior. In addition, it examines how cell structural networks affect gene and protein signaling networks to produce characteristic phenotypes and cell fate transitions during tissue development.

Animals↗
PubMed1998

Planning and cost analysis of digital radiography services for a network of hospitals (the Veterans Integrated Service Network).

This study analysed the design and cost of a picture archiving and communications system (PACS), computerized radiography (CR) and a wide-area network for teleradiology. The Desert Pacific Healthcare Network comprises 10 facilities, including four tertiary medical centres and one small hospital. Data were collected on radiologists' workloads, and patient and image flow within and between these medical centres. These were used to estimate the size and cash flows associated with a system-wide implementation of PACS, CR and teleradiology services. A cost analysis model was used to estimate the potential cost savings in a filmless radiology environment. ATM technology was selected as the communications medium between the medical centres. A strategic plan and business plan were successfully developed. The cost model predicted the cost-effectiveness of the proposed PACS/CR configuration within four to six years, if the base costs were kept low. The experience gained in design and cost analysis of a PACS/teleradiology network will serve as a model for similar projects.

California↗
PubMed1994

A unique approach to multi-state networking: BHSL (Basic Health Sciences Network).

Development of a reciprocal multi-state shared resources network is described. The Basic Health Sciences Library Network (BHSL) is one the largest interlibrary loan networks free of direct charges to participants and any direct federal or state funding. Established in June 1986, BHSL started with 132 member libraries from three northeastern states. Current membership is 460 libraries in 10 states. Interlibrary loan activity for 1992 resulted in a collective cost savings of $592,672. This model of resource sharing can be applied to any group of libraries that access a common locator tool.

Cost Savings↗
PubMed1999

A System to Find Genetic Networks Using Weighted Network Model.

We are developing a system which finds a genetic network from data obtained by multiple gene disruptions and overexpressions. We deal with a genetic network as a weighted graph, where each weight represents the strength of activation from a gene to another gene. In this paper, we explain the overview of our system, and our strategy to visualize the weighted network. We also study the computational complexity related to the visualization.

Journal Article↗
PubMed2002

Estimation of genetic networks and functional structures between genes by using Bayesian networks and nonparametric regression.

We propose a new method for constructing genetic network from gene expression data by using Bayesian networks. We use nonparametric regression for capturing nonlinear relationships between genes and derive a new criterion for choosing the network in general situations. In a theoretical sense, our proposed theory and methodology include previous methods based on Bayes approach. We applied the proposed method to the S. cerevisiae cell cycle data and showed the effectiveness of our method by comparing with previous methods.

Bayes Theorem↗
PubMed2003

[HIV/AIDS Competence Network. An example for research networking in Germany].

Thanks to a nationwide network of specialized, clinic-associated outpatient facilities and competent registered physicians, the quality of care for HIV-infected patients in Germany is high. Although basic HIV research is also well advanced in several centers, in contrast Germany's clinical HIV research is barely discemable on an international level. This deficit is primarily due to a lack of clinical studies involving patients from across the country and the fact that no national patient cohort system exists which could provide a basis for such clinical studies. The competence network HIV/AIDS aims to overcome this shortcoming by serving as a comprehensive, nationwide research alliance. The established patient cohort is linked to 13 projects. The infrastructure required for communications and data exchange will be based on a telematics platform. There will also be various service facilities established within the network, creating an organizational structure to promote the horizontal exchange of information between centers, as well as establish the vertical exchange of knowledge between physicians, patients, public health policy makers, and the general public.

Academies and Institutes↗
PubMedDate not supplied

Overview of existing networks--is there a rationale for an Asian Cancer Registry Network?

Cancer registration is the base for our understanding of the burden of neoplastic disease in our populations at the local level. Comparability of data is essential for interpretation and this in turn depends on standardization of methodology and diagnostic and other criteria applied. If this is to be achieved across Asia, some form of international organization is clearly necessary. The question therefore should be whether the existing arrangement is adequate, and if this is not the case how a network in Asia might be established with due consideration of aims and attainable objectives. The present commentary focuses on the contributions made by the International Agency for Research on Cancer (IARC), the International Association of Cancer Registries (IACR), the European Network of Cancer Registries (ENCR), the North American Association of Central Cancer Registries (NAACCR) and individual country-based or region-based associations already active in Asia. An argument is presented here that there is a rationale for an Asian Network of Cancer Registries, working alongside and learning from the existing international organizations to promote effective cancer registration and disease prevention in Asia.

Asia↗
PubMed1997

Assessing the impact of community health information networks: a multisite field study of the Wisconsin Health Information Network.

Community health information networks (CHINs) have emerged as a promising new technology to generate cost reductions and support change in the health care industry. The proliferation of CHINs has been thwarted, however, by a conspicuous lack of evidence to support the claims of enhanced efficiency and effectiveness from CHIN participation. A recent study of the Wisconsin Health Information Network, the nation's first fully functioning CHIN, documents the benefits of this emerging technology. The findings reveal the potential for significant cost savings via electronic transmission of patient clinical and administrative information as well as enhancement of the quality of patient care.

Community Networks↗
PubMed2006

Online prediction of onsets of seizure-like events in hippocampal neural networks using wavelet artificial neural networks.

It has been previously shown that wavelet artificial neural networks (WANNs) are able to classify the different states of epileptiform activity and predict the onsets of seizure-like events (SLEs) by offline processing (Ann. Biomed. Eng. 33(6):798-810, 2005) of the electrical data from the in-vitro hippocampal slice model of recurrent spontaneous SLEs. The WANN design entailed the assumption that time-varying frequency information from the biological recordings can be used to estimate the times at which onsets of SLEs would most likely occur in the future. Progressions of different frequency components were captured by the artificial neural network (ANN) using selective frequency inputs from the initial wavelet transform of the biological data. The training of the WANN had been established using 184 SLE episodes in 34 slices from 21 rats offline. Nine of these rats also exhibited periods of interictal bursts (IBs). These IBs were included as part of the training to help distinguish the difference in dynamics of bursting activities between the preictal- and interictal type. In this paper, we present the results of an online processing using WANN on 23 in-vitro rat hippocampal slices from 9 rats having 93 spontaneous SLE episodes generated under low magnesium conditions. Over the test cases, three of the nine rats exhibited over 30 min of IB activities. We demonstrated that the WANN was able to classify the different states, namely, interictal, preictal, ictal, and IB activities with an accuracy of 86.6, 72.6, 84.5, and 69.1%, respectively. Prediction of state transitions into ictal events was achieved using regression of initial "normalized time-to-onset" estimates. The SLE onsets can be estimated up to 36.4 s ahead of their actual occurrences, with a mean error of 14.3 +/- 27.0 s. The prediction errors decreased progressively as the actual time-to-onset decreased and more initial "normalized time-to-onset" estimates were used for the regression procedure.

Action Potentials↗
PubMed2003

Use of algorithms as determinants for individual patient decision making: national comprehensive cancer network versus artificial neural networks.

The National Comprehensive Cancer Network (NCCN) developed a series of algorithms based on expert opinion to guide the treatment of patients with prostate cancer. These algorithms define acceptable treatment options according to the risk of disease recurrence and the life expectancy of the patient. However, practicing clinicians are expected to use medical judgment when making actual treatment decisions. Many clinical and pathologic variables affect patient prognosis, which, in turn, influences the treatment and surveillance of patients. Artificial neural networks (ANNs) offer promise for improving the predictive value of traditional statistical modeling. ANN models have been designed that predict risk of lymph node spread and capsular involvement during disease staging, risk of disease recurrence after prostatectomy, and overall and cause-specific survival. This article provides a review of guidelines, such as NCCN and ANN, used for the management of prostate cancer and suggests that group-level recommendations based on these algorithms or other decision trees may misrepresent individual patient preferences for treatment. Patients and their clinicians need to consider available prognostic information, including clinical status, pathologic variables, and comorbidities, and then select a reasonable treatment approach that maximizes outcome and quality of life according to the preferences of each patient.

Algorithms↗
PubMed2002

Connecting for change: networks as a vehicle for regional health reform the early experiences of the Child Health Network for the Greater Toronto Area.

The Child Health Network (CHN) for the Greater Toronto Area (GTA) is a partnership of hospital, rehabilitation and community providers committed to developing a regional system to deliver high quality, accessible, family-centred care for mothers, newborns, children and youth. This article reviews the history and model of the CHN, assesses its achievements, and provides insights into the challenges and lessons learned by the network. Stemming from the CHN's commitment to quality, accessibility and efficiency, regionalization of maternal, newborn and children's services is emerging as a success story.

Canada↗
PubMed1997

Partnerships between self-help networks and health care facilities: the case of the Bayview Support Network.

This article discusses the role of patients and their families as peer support providers to other patients, and as decision makers within organizations. We use as a model the Bayview Support Network, a self-help network at the Toronto-Sunnybrook Regional Cancer Centre. We review the benefits of partnership, costs, limitations and risks. A list of features that contribute to effective partnership is also provided.

Cancer Care Facilities↗
PubMed2002

An intelligent sales forecasting system through integration of artificial neural networks and fuzzy neural networks with fuzzy weight elimination.

Sales forecasting plays a very prominent role in business strategy. Numerous investigations addressing this problem have generally employed statistical methods, such as regression or autoregressive and moving average (ARMA). However, sales forecasting is very complicated owing to influence by internal and external environments. Recently, artificial neural networks (ANNs) have also been applied in sales forecasting since their promising performances in the areas of control and pattern recognition. However, further improvement is still necessary since unique circumstances, e.g. promotion, cause a sudden change in the sales pattern. Thus, this study utilizes a proposed fuzzy neural network (FNN), which is able to eliminate the unimportant weights, for the sake of learning fuzzy IF-THEN rules obtained from the marketing experts with respect to promotion. The result from FNN is further integrated with the time series data through an ANN. Both the simulated and real-world problem results show that FNN with weight elimination can have lower training error compared with the regular FNN. Besides, real-world problem results also indicate that the proposed estimation system outperforms the conventional statistical method and single ANN in accuracy.

Algorithms↗
PubMed2006

[Three years of vertical networking in the German Network of Competence on Viral Hepatitis: what can we learn from the usage of different information tools?].

Treatment of patients with viral hepatitis is time-consuming and sometimes complicated. Several sources of information have been established as internet sites, however systematic analyses of the need and use of these information platforms are lacking. The Competence Network on Viral Hepatitis (Hep-Net) was established in 2002 and offers a telephone hotline, an e-mail service and a home page with frequently asked questions (FAQs). On the internet pages "FAQs" 38 125 hits have been registered on single "question-answer-units" within three years. In a half of the cases the question are associated with modes of transmission. In contrast, patient's questions in e-mail and the telephone hotline are mainly dealing with the treatment of hepatitis C. More than 46 % of the physician's questions referred to unclearness in indications for treatment. Questions on specific medical problems of individual patients and, in e-mail, also on legal issues played a major part. Many of these questions have not been addressed in the actual guidelines in Germany. In summary, the Hep-Net vertical networking tools represent a fast, quality-assured endorsement to the daily management of patients with viral hepatitis. The combination of internet, e-mail service and telephone hotline gives consideration to individual necessities of patients and physicians. However, the detailed analysis of usage also shows limitations of current guidelines which should be considered during updating.

Community Networks↗
PubMed2006

Quantitative structure-toxicity relationships (QSTRs): a comparative study of various non linear methods. General regression neural network, radial basis function neural network and support vector machine in predicting toxicity of nitro- and cyano- aromatics to Tetrahymena pyriformis.

Prediction of toxicity of 203 nitro- and cyano-aromatic chemicals to Tetrahymena pyriformis was carried out by radial basis function neural network, general regression neural network and support vector machine, in non-linear response surface methodology. Toxicity was predicted from hydrophobicity parameter (log Kow) and maximum superdelocalizability (Amax). Special attention was drawn to prediction ability and robustness of the models, investigated both in a leave-one-out and 10-fold cross validation (CV) processes. The influence that the corresponding changes in the learning sets during these CV processes could have on a common external test set including 41 compounds was also examined. This allowed us to establish the stability of the models. The non linear results slightly outperform (as expected) multilinear relationships (MLR) and also favourably compete with various other non linear approaches recently proposed by Ren (J. Chem. Inf. Comput. Sci., 43 1679 (2003)).

Animals↗