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PubMed1990

Between-register and within-register variability in event-finding and rates in the MONICA-France Project.

The 1985 and 1986 coronary event data from the three French MONICA Registers in Haute-Garonne (Toulouse), Bas-Rhin (Strasbourg) and the Urban Community of Lille (UCL) are used to compare the sources of information, the distribution of events in different diagnostic categories, and their possible effects on event rates. All three registers follow the MONICA protocol, and use the "cold pursuit" method, with data abstracted retrospectively from medical files or from the doctors establishing the causes of death. The health system and medical background are similar in the three centers. The distribution of the sources of information (in-hospital and out-of-hospital) and the distribution of events by diagnostic categories are different among centres. The possible effects of these differences on rates of definite myocardial infarction or possible coronary death are estimated between registers and within registers during a 2-year period. Cross-sectional comparisons are questionable, and possible false trends in event rates require special attention.

Adult↗
PubMed2003

[Study on the application of geographic information system in spatial distribution of hemorrhage fever with renal syndrome in China].

OBJECTIVE: To analyze the spatial distribution of hemorrhagic fever with renal syndrome (HFRS) in China by geographic information system, and to draw up a map on HRFS risk areas. METHODS: A set of database was set up using the information collected and linked to electronic maps of China in a software ArcGIS 8.01 from 41 HFRS surveillance sites during 1995 - 1998. A HFRS spatial distribution model was developed using inverse distance weighted interpolation of ArcGIS's spatial analysis method. The normalized difference vegetation index (NDVI) in each HFRS surveillance site was extracted from SPOT4 satellite vegetation imagery. Correlation analysis was performed through SPSS 10.0 to analyze the association between NDVI and HFRS incidence, HFRS risk areas were mapped under different colors. RESULTS: Spatial distribution model from HFRS surveillance sites showed that HFRS foci mainly presented in the Heilongjiang River drainage, the middle and lower reaches of the Yellow River, the middle and lower reaches of the Yangtze River, and the Jinghang grant Canal-Huaihe River drainage. It was consistent with HFRS distribution map derived from national infectious disease reporting system. Correlation analysis indicated that HFRS incidence rates were significantly associated with NDVI (r = 0.417, P < 0.01). The HFRS risk areas was mapped according to NDVI of each surveillance site. CONCLUSION: It is promising to apply GIS technology in predication of the distribution of HFRS by establishing this prediction model.

Animals↗
PubMed2003

Evaluation of informative materials on leishmaniasis distributed in Brazil: criteria and basis for the production and improvement of health education materials.

Based on categories related to structure, content, language, and illustrations, the present study provides an evaluation of the quality of educational materials on leishmaniasis available to health services in Brazil. The 18 publications evaluated consisted of four handbooks, four guided studies, four booklets, and six leaflets. Of the total publications assessed, nine were produced by the Brazilian National Health Foundation (FUNASA), five by State and Municipal Health Departments jointly with FUNASA, and one by the Pan-American Health Organization. The evaluations were also performed by three professionals: a physician specialized in leishmaniasis, a parasitologist, and an information/communications expert. The publications failed to specify key items such as target public, objective, and bibliography. The illustrations, especially in the booklets and leaflets, failed to clarify the text, portrayed biased concepts, and omitted credits and scale. According to this study, informative materials on leishmaniasis distributed in Brazil present major limitations which jeopardize the quality of information they contain.

Brazil↗
PubMed1985

Distributed memory and the representation of general and specific information.

We describe a distributed model of information processing and memory and apply it to the representation of general and specific information. The model consists of a large number of simple processing elements which send excitatory and inhibitory signals to each other via modifiable connections. Information processing is thought of as the process whereby patterns of activation are formed over the units in the model through their excitatory and inhibitory interactions. The memory trace of a processing event is the change or increment to the strengths of the interconnections that results from the processing event. The traces of separate events are superimposed on each other in the values of the connection strengths that result from the entire set of traces stored in the memory. The model is applied to a number of findings related to the question of whether we store abstract representations or an enumeration of specific experiences in memory. The model simulates the results of a number of important experiments which have been taken as evidence for the enumeration of specific experiences. At the same time, it shows how the functional equivalent of abstract representations--prototypes, logogens, and even rules--can emerge from the superposition of traces of specific experiences, when the conditions are right for this to happen. In essence, the model captures the structure present in a set of input patterns; thus, it behaves as though it had learned prototypes or rules, to the extent that the structure of the environment it has learned about can be captured by describing it in terms of these abstractions.

Association Learning↗
PubMed2003

The distribution of online healthcare information: a case study on melanoma.

To understand the difficulties users face when retrieving comprehensive healthcare information, this paper analyzes how facts related to a widely available healthcare topic are distributed across high-quality webpages. An inter-rater experiment with two skin-cancer physicians helped identify 14 facts necessary for a comprehensive understanding of melanoma risk and prevention. A second inter-rater experiment analyzed how those facts were distributed across 189 relevant webpages from high-quality sites. The analysis revealed that the distribution of facts is highly skewed, where few pages have many facts, many pages have a few facts, and no single page or site provides all the facts. A more detailed analysis suggests that the distribution is being caused by a trade-off between depth and breadth, leading to the existence of general, specialized, and sparse pages. Furthermore, the analyses reveal patterns and complexities in the relationships between facts, pages, and websites. These distribution results pinpoint the difficulties faced by searchers, and provide insights for the design of future systems that guide users in retrieving comprehensive healthcare information.

Delivery of Health Care↗
PubMedDate not supplied

Quantitative estimates of porous media wettability from proton NMR measurements.

Nuclear magnetic resonance (NMR) relaxation time distributions provide information on the abundance and distribution of two immiscible fluids in the pores of fine-grain chalk samples. A model based on relative shifts of the water-relaxation component as a function of saturation results in a wettability index that is strongly correlated with independent dynamic measurements of wettability. Scales of wetting-phase film thickness for NMR and dynamic measurements explain differences in results between the two methods.

Calcium Carbonate↗
PubMed1985

Limited information, medical entitlements and distributive justice.

This paper asks the question of how much should society spend on diagnosis as opposed to medical treatments and compensation when implementing its goals of distributive justice in health policy through publicly-funded medical entitlement programs in a world of limited information? A model is presented in which social planners seek to maximize expected social welfare by allocating medical goods, including diagnostic tests among medically dissimilar individuals when there is imperfect information about the medical condition of an individual, subject to the resource constraints of a medical entitlement fund. The goals of distributive justice underlying the social welfare function is governed by a parameter representing society's aversion to inequality. It is argued that society, given its aversion to inequality, need not always entitle the medically more fortunate individual to less treatment and compensation. Moreover, in most cases, it is socially desirable to spend a finite and equal amount on diagnostic tests for each individual, even though there is some probability of misdiagnosis. In some unusual cases, zero expenditures on diagnostic tests will be socially optimal.

Canada↗
PubMed2000

Three-dimensional matching by use of phase-only holographic information and the Wigner distribution.

Matching of three-dimensional (3-D) objects is achieved by Wigner analysis of the correlation pattern between the phase-only holographic information of a reference object and that of a target object. First, holographic information on the reference object and on the target object is extracted by use of optical scanning holography as a form of electrical signal. This electrical information is then stored in a computer for digital processing. In the digital computer, the correlation between the phase-only information of the hologram of the reference object and that of the target object is calculated and analyzed by use of a Wigner distribution. The Wigner distribution yields a space-frequency map of the correlation pattern that indicates whether the 3-D image of the target object matches that of the reference object. When the 3-D image of the target object matches that of the reference object, the Wigner distribution gives a well-defined line that directly indicates the 3-D location of the matched target object. Optical experiments with digital processing are described to demonstrate the proposed matching technique.

Journal Article↗
PubMed1987

Accents, focus distribution, and the perceived distribution of given and new information: An experiment.

This article reports on an experiment examining some perceptual consequences of correspondences between accent patterns, the distribution of plus and minus focus, and the distribution of new and given information in Dutch spoken sentences. "Accent patterns" refer here to the distribution of intonational accents over spoken sentences. Each accent marks a sentence constituent as plus focus, i.e., as highlighted by the speaker. Constituents not so marked are called minus focus. The main questions examined here are to what extent are plus focus constituents generally perceived as conveying new information, and minus focus constituents as conveying earlier introduced or given information. The linguistic material for the experiment was formed by brief radio news items, each two sentences long. Leading sentences determined the distribution of new and given information in target sentences. The accent patterns and, hence, the possible focus distributions in the target utterances were varied systematically by manipulating their synthetic pitch contours according to the rules for Dutch intonation. Subjects were asked to rate on a scale from 1-10 the acceptability of each possible combination of a leading with a target utterance. Results showed that the most preferred or acceptable distributions of new and given information closely match the distributions of plus and minus focus. It was also found that new information can hardly ever acceptably be associated with minus focus, but given information can rather often, although not always, acceptably be associated with plus focus. This appears to be limited to certain conditions, defined by a combination of syntactic and focus structure of the sentence. In these conditions, plus focus cannot be perceived only as signaling new information, but also as highlighting thematic relations with the context. These results are related to work on text-to-speech systems.

Female↗
PubMed2004

Optimal information storage and the distribution of synaptic weights: perceptron versus Purkinje cell.

It is widely believed that synaptic modifications underlie learning and memory. However, few studies have examined what can be deduced about the learning process from the distribution of synaptic weights. We analyze the perceptron, a prototypical feedforward neural network, and obtain the optimal synaptic weight distribution for a perceptron with excitatory synapses. It contains more than 50% silent synapses, and this fraction increases with storage reliability: silent synapses are therefore a necessary byproduct of optimizing learning and reliability. Exploiting the classical analogy between the perceptron and the cerebellar Purkinje cell, we fitted the optimal weight distribution to that measured for granule cell-Purkinje cell synapses. The two distributions agreed well, suggesting that the Purkinje cell can learn up to 5 kilobytes of information, in the form of 40,000 input-output associations.

Afferent Pathways↗
PubMed1980

The distribution of mutant alleles in a subdivided population.

The results are presented from a simulation study of the spatial distribution of mutant alleles in a subdivided population. Statistical measures of the spatial pattern are defined in such a way that the same quantities could be measured in a geographic survey of allele frequencies in natural populations. Two types of quantities are discussed in this paper: (1) the occupancy distribution provides information on the presence or absence of the mutant in different numbers of demes; and (2) the conditional frequency distribution provides information about the extent of local differentiation when the mutant is present in different numbers of demes. Properties of these distributions are found for different types of natural selection acting on the mutant. Some results are presented for the same statistical measures based on samples of individuals from a fraction of the total number of demes. The simulation results for intermediate levels of the migration rates are compared with analytic results obtained on the limits of high and low migration rates. The main conclusion is that these measures of the spatial distribution of mutants in a subdivided population have simple properties that could provide a new perspective on data from natural populations.

Alleles↗
PubMed2006

Bayesian sample size calculations in phase II clinical trials using a mixture of informative priors.

A number of researchers have discussed phase II clinical trials from a Bayesian perspective. A recent article by Mayo and Gajewski focuses on sample size calculations, which they determine by specifying an informative prior distribution and then calculating a posterior probability that the true response will exceed a prespecified target. In this article, we extend these sample size calculations to include a mixture of informative prior distributions. The mixture comes from several sources of information. For example consider information from two (or more) clinicians. The first clinician is pessimistic about the drug and the second clinician is optimistic. We tabulate the results for sample size design using the fact that the simple mixture of Betas is a conjugate family for the Beta- Binomial model. We discuss the theoretical framework for these types of Bayesian designs and show that the Bayesian designs in this paper approximate this theoretical framework.

Algorithms↗
PubMedDate not supplied

Distributions of distances in information strings.

Distances between identical symbols in information strings (biological, language, computer programs (*.exe files) are described with a different precision with four distributions: exponential, Weibull, log-normal and negative binomial. The correlations are sometimes highly significant.

Amino Acid Sequence↗
PubMed2001

Simulating canopy stomatal conductance of winter wheat and its distribution using remote sensing information.

The canopy stomatal movement, a plant physiological process, generally occurs within leaves but its influence on exchange of CO2, water vapor, and sensible heat fluxes between atmosphere and terrestrial ecosystem. Many studies have documented that the interaction between leaf photosynthesis and canopy stomatal conductance is obvious. Thus, information on stomatal conductance is valuable in climate and ecosystem models. In current study, a newly developed model was adopted to calculate canopy stomatal conductance of winter wheat in Huang-Huai-Hai (H-H-H) Plain of China (31.5-42.7 degrees N, 110.0-123.0 degrees E). The remote sensing information from NOAA-AVHRR and meteorological observed data were used to estimate regional scale stomatal conductance distribution. Canopy stomatal conductance distribution pattern of winter wheat on March 18, 1997 was also presented. The developed canopy stomatal conductance model might be used to estimate canopy stomatal conductance in land surface schemes and seems can be acted as a boundary condition in regional climatic model runs.

Carbon Dioxide↗
PubMed2004

Medical information asymmetry in the cyberworld of manuel castells.

Before 1997, the Internet was strongly associated with universities and higher education, including medical research. There were only small virtual communities at that time, but all their members had equal access to the entire body of information placed on the net. Each networking participant was able not only to retrieve but also to create and distribute medical information. This state was a symmetry, of sorts, between passive and active Internet usage. Since that time, however, significant commercialization of the Internet (including the medical domain) has been increasing its asymmetry. We currently observe a division into providers, serving and distributing medical information on the net, and consumers, who receive pre-prepared "products". This brings new challenges for both academic and practicing e-health physicians. First, while all large-scale initiatives to certify medical portals have so far failed, the public must be educated to chose valuable, high quality medical information themselves. Secondly, this imbalance favors abusive commercial behavior, such as spam, spreading viruses and advertising without content-related information. Stimulating a restoration of the previous idea of the Internet for non-profit activities seems to be best way to avoid the continuation of Internet "degeneration". Manuel Castells has defined future industrial and postindustrial progress of humanity as activity in global virtual communities, interchanging ideas, knowledge and information. The role of medical professionals seems to be to educate patients and their families on how to search for quality medical information and to stimulate other medical professionals, researchers as well as patients' supportive groups to be active themselves. Reducing the medical information asymmetry will provide a positive influence on the progress of e-health in the future. Open source software may help reduce costs by creating adequate resources.

Humans↗
PubMed2003

Workflow-enabled distributed component-based information architecture for digital medical imaging enterprises.

Few information systems today offer a flexible means to define and manage the automated part of radiology processes, which provide clinical imaging services for the entire healthcare organization. Even fewer of them provide a coherent architecture that can easily cope with heterogeneity and inevitable local adaptation of applications and can integrate clinical and administrative information to aid better clinical, operational, and business decisions. We describe an innovative enterprise architecture of image information management systems to fill the needs. Such a system is based on the interplay of production workflow management, distributed object computing, Java and Web techniques, and in-depth domain knowledge in radiology operations. Our design adapts the approach of "4+1" architectural view. In this new architecture, PACS and RIS become one while the user interaction can be automated by customized workflow process. Clinical service applications are implemented as active components. They can be reasonably substituted by applications of local adaptations and can be multiplied for fault tolerance and load balancing. Furthermore, the workflow-enabled digital radiology system would provide powerful query and statistical functions for managing resources and improving productivity. This paper will potentially lead to a new direction of image information management. We illustrate the innovative design with examples taken from an implemented system.

Computer Communication Networks↗
PubMed1979

Actinobacillus seminis infection in sheep in the Republic of South Africa. II. Incidence and geographical distribution.

To obtain information on the incidence and distribution of Actinobacillus seminis infection in the Republic of South Africa, a clinical and serological survey was carried out on 409 farms situated in 29 districts. All rams submitted for certification to the Regional Laboratory from 1/1/69 to 31/1/74 were included in a separate investigation. These particular rams represented different breeds and originated from farms in over 48 districts. Examinations were also carried out on all rams on 11 stud farms in the Middelburg and adjacent districts with a high incidence of epididymitis, despite regular immunization with Elberg Rev. 1 vaccine. These investigations confirmed that genital infection of rams still presents a major problem in the main sheep breeds and the main sheep farming areas of South Africa. A high incidence of infection with A. seminis, an organism which appear to be the most important one associated with genital infection in this country, was also established. Genital infection due to A. seminis is geographically also very widespread.

Actinobacillus Infections↗