Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Medical Informatics Computing”

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 451 records · Page 25Linked to original sources
PubMed2004

Beyond the gadgets.

Explore the source record for details and available documents.

Attitude to Computers↗
PubMed2000

Two applications of information extraction to biological science journal articles: enzyme interactions and protein structures.

Information extraction technology, as defined and developed through the U.S. DARPA Message Understanding Conferences (MUCs), has proved successful at extracting information primarily from newswire texts and primarily in domains concerned with human activity. In this paper we consider the application of this technology to the extraction of information from scientific journal papers in the area of molecular biology. In particular, we describe how an information extraction system designed to participate in the MUC exercises has been modified for two bioinformatics applications: EMPathIE, concerned with enzyme and metabolic pathways; and PASTA, concerned with protein structure. Progress to date provides convincing grounds for believing that IE techniques will deliver novel and effective ways for scientists to make use of the core literature which defines their disciplines.

Binding Sites↗
PubMed2000

Information dynamics of in vitro selection-amplification systems.

Selection-amplifications systems provide a means of engineering biomacromolecules with new properties. The combination of stringent functional selection with the ability to amplify single molecules confers great specificity on the evolving population. Yet such systems like many complicated chemical kinetic mechanisms can show a range of unstable and metastable behavior. These instabilities can be investigated using the Shannon entropy of the evolving population. It is shown that the Shannon entropy provides a Lyapounov function for exploring dynamic stability. A simple model of in vitro evolution is presented and stability conditions are established. It is seen that fairly simple directed evolution models can exhibit a range of dynamical behavior.

Directed Molecular Evolution↗
PubMed2000

An analytic solution to single nucleotide polymorphism error-detection rates in nuclear families: implications for study design.

Recently, there has been increased interest in using Single Nucleotide Polymorphisms (SNPs) as a method for detecting genes for complex traits. SNPs are diallelic markers that have the potential to be inexpensively produced using chip technology. It has been suggested that SNPs will be beneficial in study designs that utilize trio data (father, mother, child). In our previous work, we calculated the probability of detecting Mendelian errors at a SNP locus for a trio randomly selected from a population in Hardy-Weinberg equilibrium. The highest error-detection rate was 30%. Here we investigate the error-detection rate when additional sibs are genotyped. We define an error to be a change from a 1 allele to a 2 allele, or vice versa. Typing one additional sib increases the detection rate on average by 10-13%. Typing two additional sibs increases the detection rate on average by 14-19%. The increase in the detection rate is dependent on the allele frequencies. Equal allele frequencies produce the lowest detection rates, independent of true error rates and number of offspring genotyped. Typing additional siblings not only improves error-detection rates, but can also provide additional linkage information. In order to increase linkage information and error-detection rates, at least two additional siblings should be ascertained when available.

Alleles↗
PubMed2000

The haplotype linkage disequilibrium test for genome-wide screens: its power and study design.

The focus of human genetics continues to shift toward the dissection of complex phenotypes. Integral to these endeavors is the development of powerful analytical tools. To this end, we propose a novel method designated the haplotype linkage disequibrium (LD) test for identifying diseases genes. The basic structure of the haplotype test statistic is a chi-square in which haplotypes, as opposed to individual marker data, are compared between cases and controls. Specifically, we performed power calculations and demonstrate that the use of haplotypes improves the power of mapping disease genes. We show that this approach can be used for initial genome-wide screens in mapping disease genes. Furthermore, we investigated the factors influencing statistical power of the method and discussed basic principals underlying study design. Published data from the Hereditary Hemochromatosis region was used to illustrate the utility of the haplotype test. Also discussed is its relationship with linkage disequibrium.

Alleles↗
PubMed1997

Data mining of inputs: analysing magnitude and functional measures.

The problem of data encoding and feature selection for training back-propagation neural networks is well known. The basic principles are to avoid encrypting the underlying structure of the data, and to avoid using irrelevant inputs. This is not easy in the real world, where we often receive data which has been processed by at least one previous user. The data may contain too many instances of some class, and too few instances of other classes. Real data sets often include many irrelevant or redundant input fields. This paper examines the use of weight matrix analysis techniques and functional measures using two real (and hence noisy) data sets. The first part of this paper examines the use of the weight matrix of the trained neural network itself to determine which inputs are significant. A new technique is introduced and compared with two other techniques from the literature. We present our experience and results on some satellite data augmented by a terrain model. The task was to predict the forest supra-type based on the available information. A brute force technique eliminating randomly selected inputs was used to validate our approach. The second part of this paper examines the use of measures to determine the functional contribution of inputs to outputs. Inputs which include minor but unique information to the network are more significant than inputs with higher magnitude contribution but providing redundant information, which is also provided by another input. A comparison is made to sensitivity analysis, where the sensitivity of outputs to input perturbation is used as a measure of the significance of inputs. This paper presents a novel functional analysis of the weight matrix based on a technique developed for determining the behavioral significance of hidden neurons. This is compared with the application of the same technique to the training and test data. Finally, a novel aggregation technique is introduced.

Algorithms↗
PubMedDate not supplied

Principal component analysis for content-based image retrieval.

Most picture archiving and communication systems provide image search capabilities that support queries based on patient demographics and study descriptions. In a preliminary study, principal component analysis was used to represent and retrieve images on the basis of content. Principal component analysis reduces the dimensionality of the search to a basis set of prototype images that best describes the images. Each image is described by its projection on the basis set; a match to a query image is determined by comparing its projection vector on the basis set with that of the images in the database. The training image database consisted of 100 axial brain images from a three-dimensional T1-weighted magnetic resonance imaging study. The algorithm was evaluated by using 96 axial images from eight patients. Image retrieval was considered accurate if the automated algorithm returned the match section to within 3 mm of an expert-selected section; the retrieval accuracy was 83% when the images were preprocessed for uniformity in intensity and geometry. Principal component analysis can be applied to content-based retrieval of medical images. The algorithm is designed to be part of an automated image selection module that filters relevant images from an imaging study.

Algorithms↗
PubMed2000

Managing the 'fit' of information and communication technology in community health: a framework for decision making.

The 'fit' of information and communication technologies (ICT) in community health is important in meeting the needs of patients, carers, staff and organizations in the delivery of services. A good fit leads to greater efficiencies and effectiveness in ICT use. A multi-step research project was conducted to look not only at the role of ICT but at how to manage ICT and make a good ICT fit to enhance community health services. Telehealth was identified as the application of ICT to enhance population health, health promotion and health-service delivery. A participatory process was identified as critical to determining needs and potential uses as well as to the successful design and implementation of ICT in health. There was additional value in ensuring a diversity of desired outcomes which balance costs and benefits while fostering capacity and technical sustainability.

Canada↗
PubMed1998

Primary pulmonary hypertension: insights into pathogenesis from epidemiology.

Primary pulmonary hypertension (PPH) is a rare disease that affects young people predominantly of female gender. Early epidemiologic studies have shown that the diagnosis is usually made 1 to 2 years after symptoms onset, and the mean survival is reduced to 2 to 3 years thereafter. New insights into the pathogenesis of PPH by epidemiologic studies may be obtained through the utilization of informatic technologies coupled to a clear definition of the disease. Early stages of precapillary pulmonary hypertension could be identified through screening tests like echocardiography in populations with higher incidence, such as familial PPH and the conditions associated with pulmonary hypertension. These latter conditions are hemodynamically and pathologically similar to the primary form, and they can give insight into several possible aspects of the pathogenesis of PPH. Prospective registries are very useful in coordinating the collection of epidemiologic data, and new technologies, such as informatics, may improve the management and the continuous updating of the databases.

Adult↗
PubMed1988

An application of the Markov process for quantitative prediction of labor progress.

To quantitatively predict the progress of labor, we devised a mathematical model suitable for the Markov process. Included were 625 primiparas who went into spontaneous labor between 37 and 41 weeks of gestation with a cephalic presentation. When applying the Markov process, the sequence of labor was divided into eight categories from 4 cm cervical dilatation to delivery of the baby. Based on all data collected, a transition matrix was calculated, using a microcomputer system, in which the value in each element showed the percent of probability of progression in labor from one given state to another over a 30-minute period. This matrix was found to be available for evaluating the course of labor in clinical practise with a good predictive value and therefore the Markov process could be confirmed to be actually applicable as an analytical model.

Female↗