Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Information Distribution”

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 685 records · Page 38Linked to original sources
PubMed1989

Evaluation of "your pregnancy"--a New Zealand health information booklet for pregnant women.

"Your Pregnancy" is a health information booklet distributed to all pregnant women in New Zealand free of charge. Evaluation of the accessibility, acceptability, and effectiveness of the booklet was undertaken. Two groups of women were surveyed 4-5 months after their first babies were born. The first group of women (n = 281) was surveyed before the booklet was introduced and the second group (n = 267) after its distribution. The overall response rate was 79 per cent. Accessibility of the booklet was assessed from the survey of the second group of women. The majority of women received the booklet eventually, but only 62 per cent in the first trimester. Of those women who received the booklet, 73 per cent passed it on to others. Evaluation of the booklet's acceptability was undertaken by calling for submissions from professional and lay groups (n = 41) on all aspects of the booklet and from analysis of responses to the second survey. The booklet was generally acceptable to women and health professionals. Effectiveness of the booklet was gauged by comparing the two groups of women on the extent to which their needs for information had been met, the ease with which they could question others about their pregnancy, locus of control, self-care and self-knowledge. The only variable which showed a change between the two surveys was an improvement in the extent to which women's needs for information had been met.

Consumer Behavior↗
PubMed1999

A simple way to estimate the median time and compare survival distributions in analgesic trials under informative censoring.

We discuss the problem of estimating the median time and comparison of survival curves when data are nonrandomly censored in analgesic trials. In these trials patients experience post-surgical pain at the time of randomization. Time to onset of analgesia is measured by patient-administered stopwatches. An effective analgesic is one for which the median time to onset is "short." The study design allows patients to remedicate if their pain persists, and this remedication prior to pain relief censors the time-to-onset measures. The time to onset for patients who remedicate is nonrandomly censored. Assuming noninformative censoring yields misleading results with the Kaplan-Meier method (for estimation of median time) and the log-rank test (for comparison of survival curves). This assumption can also obscure the superior effect of an effective analgesic over an ineffective one. We propose a simple and intuitive way to handle the nonrandomly censored data in analgesic trials in order to (a) estimate the median time to pain relief and (b) compare the survival distributions between treatments. The method proposed is applied to data collected from an acute pain clinical trial, and the results are discussed.

Analgesics↗
PubMed2000

Secure interoperability of patient data cards in health networks.

In the healthcare area, chip card based information systems occur in the shape of patient data cards providing informational self determination and mobility of the users as well as quality, integrity, accountability, and availability of the data stored on the card, thus improving the shared care of patients. Dealing with sensitive personal medical information, shared care information systems have to provide appropriate security services, only authorized users allowing restricted rights to the patients' data according to the "need to know" principle. The DIABCARD project aims the implementation and evaluation of a chip card based medical information system (CCMIS) for facilitating communication and co-operation between health professionals in different organisations or departments caring the same patient with Diabetes as an example. In co-operation with the EC-funded TrustHealth project, the communication and application security services needed are provided as strong authentication and the derived services like authorization, access control, accountability, confidentiality etc. The solution is based on Health Professional Cards and Trusted Third Party services. Besides the secure handling of the patient's chip cart in DIABCARD workstations, also the secure communication between these workstations and related departmental systems has been implemented. Finally, a few legal issues, future trends like the XML standard set and their implications for the solution presented as well as for distributed health information systems in general are shortly discussed.

Computer Communication Networks↗
PubMed1993

Quantitative localization of AMPA/kainate and kainate glutamate receptor subunit immunoreactivity in neurochemically identified subpopulations of neurons in the prefrontal cortex of the macaque monkey.

Excitatory amino acid transmission has been proposed as the principal synaptic mechanism for distribution of information through corticocortical and thalamocortical pathways. The following study utilized a double labeling paradigm, using antibodies that recognize non-NMDA ionotropic glutamate receptor subunits and other neuronal markers, to further define, quantitatively, the subclasses of neurons that contain immunoreactivity for the AMPA/kainate and kainate receptor subunits in the monkey prefrontal cortex. Double labeling with an antibody that recognizes common epitopes in AMPA/kainate subunits GluR2 and GluR3 (GluR2/3) in combination with an antibody that recognizes the kainate receptor subunits GluR5, GluR6, and GluR7 (GluR5/6/7) demonstrated that immunoreactivity for these two receptor classes was highly colocalized in a great majority of the pyramidal neurons in this region but present in only a minority of neurochemically identified subclasses of GABAergic interneurons. Furthermore, GluR2/3 immunoreactivity had principally a somatic distribution whereas GluR5/6/7 labeling was predominately found in the perikarya and/or particular dendritic domains. In contrast, intense GluR1 labeling was observed in a small subpopulation of interneurons and low GluR1 immunoreactivity was present in many other cortical neurons. These results demonstrate that there is a high degree of specificity in the distribution of AMPA/kainate and kainate receptor-class proteins to subclasses of neurons within the neocortex. A neuron's combination of excitatory amino acid receptor subunits may regulate its response to excitatory inputs and further defines the role of identified subclasses of neurons in the complex circuitry of the cerebral cortex and may also indicate the basis for the apparent cellular selectivity of excitotoxic degenerative processes.

Alzheimer Disease↗
PubMed2006

Power and sample size for testing associations of haplotypes with complex traits.

Evaluation of the association of haplotypes with either quantitative traits or disease status is common practice, and under some situations provides greater power than the evaluation of individual marker loci. The focus on haplotype analyses will increase as more single nucleotide polymorphisms (SNPs) are discovered, either because of interest in candidate gene regions, or because of interest in genome-wide association studies. However, there is little guidance on the determination of the sample size needed to achieve the desired power for a study, particularly when linkage phase of the haplotypes is unknown, and when a subset of tag-SNP markers is measured. There is a growing wealth of information on the distribution of haplotypes in different populations, and it is not unusual for investigators to measure genetic markers in pilot studies in order to gain knowledge of the distribution of haplotypes in the target population. Starting with this basic information on the distribution of haplotypes, we derive analytic methods to determine sample size or power to test the association of haplotypes with either a quantitative trait or disease status (e.g., a case-control study design), assuming that all subjects are unrelated. Our derivations cover both phase-known and phase-unknown haplotypes, allowing evaluation of the loss of efficiency due to unknown phase. We also extend our methods to when a subset of tag-SNPs is chosen, allowing investigators to explore the impact of tag-SNPs on power. Simulations illustrate that the theoretical power predictions are quite accurate over a broad range of conditions. Our theoretical formulae should provide useful guidance when planning haplotype association studies.

Computer Simulation↗
PubMed1994

Changes in proteoglycans of ageing and osteoarthritic human articular cartilage: an electron microscopic study with polyethyleneimine.

BACKGROUND: Ageing and osteoarthritic (OA) cartilage show characteristic alterations in chondrocyte morphology and in the composition and content of matrix proteoglycans (PGs). Data concerning matrix components are mostly of biochemical nature. Ultrastructural histochemistry is needed to gain more information about distribution of these altered matrix components. METHODS: We used the cationic dye polyethyleneimine (PEI) to visualize at the EM level alterations in the distribution and dimensions of PGs of human healthy young, healthy aged, and OA articular cartilage. RESULTS: Young cartilage contained PEI-positive granules in the superficial layer and big winding PEI-positive structures in the deeper layers. In the healthy aged tissue, PEI-positive granules were observed throughout the matrix and smaller winding structures were present in the deeper layer. In OA cartilage both types of PEI-positive structures were absent in the superficial layer. Deeper in the matrix PEI-positive granules could be demonstrated. Moreover, PEI-positive angular structures were observed in the deeper zones. CONCLUSIONS: The differences in PEI-positive structures are a good reflection of the differences in PGs between young, ageing, and OA cartilage as demonstrated in biochemical studies. PEI, used at the EM level, gave more precise information concerning the localized changes in quality, quantity, and location of PGs in articular cartilage during ageing and disease.

Aged↗
PubMed1978

Cost-benefit and cost-effectiveness: methodologies for evaluating innovative pharmaceutical services.

Cost-benefit and cost-effectiveness analysis techniques which can be of assistance in the evaluation of innovative pharmaceutical services are reviewed. Process and outcome measures are considered, and suggested steps in a cost-benefit study are presented. Samples of pharmacy studies using these techniques are appraised. Possible measures for benefits and costs along with literature references for evaluations of innovative pharmaceutical services are presented. Areas of pharmaceutical service discussed are ambulatory patient consultation, unit dose drug distribution, drug information services, monitoring drug therapy in acute care and long-term care, parenteral admixture services, patient and therapy responsibilities, patient discharge interviews, patient drug histories and profiles, and personnel substitutions. Although there have been several encouraging reports on the cost-benefit of pharmaceutical services, more evaluative research is needed to develop programs which maximize the benefit-to-cost ratio to society.

Cost-Benefit Analysis↗
PubMed2004

Human papillomavirus in a rural community in Zimbabwe: the impact of HIV co-infection on HPV genotype distribution.

Cervical cancer is a leading cause of cancer-related deaths in developing countries, and the human papillomavirus (HPV) is linked etiologically to cervical cancer. Hence, a vaccine which prevents HPV-associated cervical cancer would have the most impact in developing countries, including the African continent. The type-specific immune response towards HPV virus-like particles, in combination with geographical variation in the prevalence of HPV, necessitates the presence of multiple HPV type antigens in a single vaccine cocktail in order to provide relevant protection. We aimed to investigate whether co-infection with HIV, which is highly prevalent in Africa, plays a role in HPV genotype distribution. After informed consent, HPV detection by GP5+/6+ PCR and HIV detection by serology was carried out on 236 women from the rural north-western part of Zimbabwe. The prevalence of HPV was higher in HIV positive women (54%) than in HIV negative women (27%). Certain HPV types (HPV types 11, 39, 43, 51, and 59, P-values ranging from 0.017 to 0.067) occurred more frequently in HIV positive women. Only high-risk HPV, and not HIV, was associated significantly with cervical intraepithelial neoplasia in multiple regression analysis. In conclusion, a high prevalence of HPV was found in a rural community, where regular Papanicolaou (Pap) smears would be a logistic and economic impossibility, but where free vaccination programmes against other infections are already established. The results suggest that HIV co-infection may have an impact on HPV genotype distribution.

Adolescent↗
PubMed2005

Characterization of marine aerosol for assessment of human exposure to brevetoxins.

Red tides in the Gulf of Mexico are commonly formed by the fish-killing dinoflagellate Karenia brevis, which produces nine potent polyether brevetoxins (PbTxs). Brevetoxins can be transferred from water to air in wind-powered white-capped waves. Inhalation exposure to marine aerosol containing brevetoxins causes respiratory symptoms. We describe detailed characterization of aerosols during an epidemiologic study of occupational exposure to Florida red tide aerosol in terms of its concentration, toxin profile, and particle size distribution. This information is essential in understanding its source, assessing exposure to people, and estimating dose of inhaled aerosols. Environmental sampling confirmed the presence of brevetoxins in water and air during a red tide exposure period (September 2001) and lack of significant toxin levels in the water and air during an unexposed period (May 2002). Water samples collected during a red tide bloom in 2001 showed moderate-to-high concentrations of K. brevis cells and PbTxs. The daily mean PbTx concentration in water samples ranged from 8 to 28 microg/L from 7 to 11 September 2001; the daily mean PbTx concentration in air samples ranged from 1.3 to 27 ng/m(3). The daily aerosol concentration on the beach can be related to PbTx concentration in water, wind speed, and wind direction. Personal samples confirmed human exposure to red tide aerosols. The particle size distribution showed a mean aerodynamic diameter in the size range of 6-12 microm, with deposits mainly in the upper airways. The deposition pattern correlated with the observed increase of upper airway symptoms in healthy lifeguards during the exposure periods.

Aerosols↗
PubMed2005

A note on comparing exposure data to a regulatory limit in the presence of unexposed and a limit of detection.

In some occupational health studies, observations occur in both exposed and unexposed individuals. If the levels of all exposed individuals have been detected, a two-part zero-inflated log-normal model is usually recommended, which assumes that the data has a probability mass at zero for unexposed individuals and a continuous response for values greater than zero for exposed individuals. However, many quantitative exposure measurements are subject to left censoring due to values falling below assay detection limits. A zero-inflated log-normal mixture model is suggested in this situation since unexposed zeros are not distinguishable from those exposed with values below detection limits. In the context of this mixture distribution, the information contributed by values falling below a fixed detection limit is used only to estimate the probability of unexposed. We consider sample size and statistical power calculation when comparing the median of exposed measurements to a regulatory limit. We calculate the required sample size for the data presented in a recent paper comparing the benzene TWA exposure data to a regulatory occupational exposure limit. A simulation study is conducted to investigate the performance of the proposed sample size calculation methods.

Algorithms↗
PubMed2000

Data discretization for novel resource discovery in large medical data sets.

This paper is motivated by the problems of dealing with large data sets in information retrieval. The authors suggest an information retrieval framework based on mathematical principles to organize and permit end-user manipulation of a retrieval set. By adjusting through the interface the weights and types of relationships between query and set members, it is possible to expose unanticipated, novel relationships between the query/document pair. The retrieval set as a whole is parsed into discrete concept-oriented subsets (based on within-set similarity measures) and displayed on screen as interactive "graphic nodes" in an information space, distributed at first based on the vector model (similarity measure of set to query). The result is a visualized map wherein it is possible to identify main concept regions and multiple sub-regions as dimensions of the same data. Users may examine the membership within sub-regions. Based on this framework, a data visualization user interface was designed to encourage users to work with the data on multiple levels to find novel relationships between the query and retrieval set members. Space constraints prohibit addressing all aspects of this project.

Computer Graphics↗
PubMed2001

Assessment of impact of information booklets on use of healthcare services: randomised controlled trial.

OBJECTIVES: To investigate the effect of patient information booklets on overall use of health services, on particular types of use, and on possible interactions between use, deprivation category of the area in which respondents live, and age. To investigate the possibility of a differential effect on health service use between two information booklets. DESIGN: Randomised controlled trial of two patient information booklets (covering the management and treatment of minor illness). SETTING: 20 general practices in Lothian, Scotland. PARTICIPANTS: Random sample of patients from the community health index (n=4878) and of those contacting out of hours services (n=4530) in the previous 12 months in each of the study general practices. INTERVENTION: Booklets were posted to participants in intervention groups (3288 were sent What Should I Do?; 3127 were sent Health Care Manual). Patients randomised to control group (2993) did not receive a booklet. MAIN OUTCOME MEASURES: Use of health services audited from patients' general practice notes in 12 months after receipt of booklet. RESULTS: Receipt of either booklet had no significant effect on health service use compared with a control group. However, nine out of ten matched practices allocated to receive Health Care Manual had reduced consultation rates compared with matched practices allocated to What Should I Do? CONCLUSION: Widespread distribution of information booklets about the management of minor illness is unlikely to reduce demand for health services.

Family Practice↗
PubMed1996

Rapid distribution of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to embryonic tissues in C57BL/6N mice and correlation with palatal uptake in vitro.

2,3,7,8-Tetracholoridbenzo-p-dioxin (TCDD) is a developmentally toxic environmental contaminant capable of inducing cleft palate and hydronephrosis in embryonic C57BL/6N mice. In this study, the disposition of TCDD was determined in pregnant C57BL/6N mice in the 24 hr immediately following oral administration on Gestation Day (GD) 12. TCDD was detected in maternal blood, liver, and fat and in the placenta, embryonic liver, and palate within 30 min after dosing on GD 12. The levels peaked in blood and placenta at 3 hr and in the other tissues at 8 hr. Levels of TCDD decreased slightly after 8 hr in embryonic liver and palate. In vitro systems were used to study the mechanisms of action of TCDD and in these models exposure is typically reported as concentration of TCDD in the culture medium. The present study is the first to allow a direct comparison of the level of TCDD in embryonic tissue after in vivo and in vitro exposures. Uptake of TCDD was determined in embryonic palatal organ culture and tissue levels were then expressed in comparable units for both in vivo and in vitro exposures. The data provide new information on distribution in the pregnant mouse and the embryo and also show that the palatal organ culture model provides a reasonable dosimetric representation of in utero exposure.

Administration, Oral↗
PubMed1986

A time-comparison circuit in the electric fish midbrain. II. Functional morphology.

The weakly electric fish Eigenmannia is able to detect temporal disparities as small as 400 nsec between two signals from different parts of the body surface (Carr et al., 1986). The elements of this time-comparison circuit have been identified by EM reconstruction of its component cells. Information about the timing of the zero-crossing of signals on each area of the body surface is coded in phase-coder receptors, a subset of tuberous electroreceptors. Electroreceptors on the body surface are innervated by primary afferents with their central termination on the spherical cells of the medullary electrosensory lateral line lobe. These cells project to lamina VI of the midbrain torus, a structure similar to the inferior colliculus. Afferents entering lamina VI form a very restricted terminal arbor in which they synapse on the three cell types of this lamina. Each afferent makes gap-junction synapses on one or two giant cell somata and morphologically mixed synapses on the distal dendrites of two types of small cell. The afferent terminals thus encode the timing of the electric signal on a local patch of the body surface, forming a somatotopic map of the body surface in lamina VI. The giant cells are adendritic and their axonal arbor is such as to distribute timing information originating from one part of the body surface throughout lamina VI, so that each region of lamina VI receives information about the timing of zero-crossings from the entire body surface from giant cells, as well as information from a local portion of the body surface from the afferent terminals. The giant cells terminate exclusively on the cell bodies of the small cells of lamina VI, shown to be sensitive to small temporal disparities by Heiligenberg and Rose (1985). Thus, each small cell receives a single synapse on its soma from a giant cell that conveys phase-coding information from some portion of the body surface and receives local phase-coding input onto its dendrites from spherical cell afferents. The sensitivity of the small cells to temporal disparities appears to be conferred by their segregation of inputs from two different parts of the body surface onto dendrites and soma, respectively. We propose that the dendritic input acts as a delay line, and the small cell fires maximally when the inputs from the dendrites and the giant cell input onto the soma coincide.

Animals↗
PubMed2006

Experimental purification of two-atom entanglement.

Entanglement is a necessary resource for quantum applications--entanglement established between quantum systems at different locations enables private communication and quantum teleportation, and facilitates quantum information processing. Distributed entanglement is established by preparing an entangled pair of quantum particles in one location, and transporting one member of the pair to another location. However, decoherence during transport reduces the quality (fidelity) of the entanglement. A protocol to achieve entanglement 'purification' has been proposed to improve the fidelity after transport. This protocol uses separate quantum operations at each location and classical communication to distil high-fidelity entangled pairs from lower-fidelity pairs. Proof-of-principle experiments distilling entangled photon pairs have been carried out. However, these experiments obtained distilled pairs with a low probability of success and required destruction of the entangled pairs, rendering them unavailable for further processing. Here we report efficient and non-destructive entanglement purification with atomic quantum bits. Two noisy entangled pairs were created and distilled into one higher-fidelity pair available for further use. Success probabilities were above 35 per cent. The many applications of entanglement purification make it one of the most important techniques in quantum information processing.

Journal Article↗
PubMed2002

The micro-macro spectrum of medical informatics challenges: from molecular medicine to transforming health care in a globalizing society.

BACKGROUND: Medical informatics has always encompassed a very broad spectrum of techniques for clinical and biomedical research, education and practice. There has been a concomitant variety of depth of specialization, ranging from the routine application of information processing methods to cutting-edge research on fundamental problems of computer-based systems and their relations to cognition and perception in biomedicine. OBJECTIVES: Challenges for the field can be placed in perspective by considering the scale of each--from the highly detailed scientific problems in bioinformatics and emerging molecular medicine to the broad and complex social problems of introducing medical informatics into web-related global settings. METHODS: The scale of an informatics problem is not only determined by the inherent physical space in which it exists, but also by the conceptual complexity that it involves, reinforcing the need to investigate the semantic web within which medical informatics is defined. RESULTS AND CONCLUSION: Bioinformatics, biomedical imaging and language understanding provide examples that anchor research and practice in biomedical informatics at the detailed, scientific end of the spectrum. Traditional concerns of medical informatics in the clinical arena make up the broad mid-range of the spectrum, while novel social interaction models of competition and cooperation will be needed to understand the implications of distributed health information technology for individual and societal change in an increasingly interconnected world.

Databases, Factual↗
PubMed1994

The location of the third cleavage plane of Xenopus embryos partitions morphogenetic information in animal quartets.

Analysis of the developmental potential of animal quartets (the set of four animal blastomeres isolated from the 8-cell stage Xenopus embryo) provided insight into the manner in which morphogenetic information is distributed along the animal-vegetal axis. Gravity treatments were employed to alter the partitioning plane. Animal quartets isolated from embryos exposed to simulated weightlessness had larger animal blastomeres, and they formed structures such as a groove and a protrusion more often than 1g-control animal quartets. Animal quartets with an unusual non-horizontal third cleavage plane were also found to have a higher frequency of protrusion formation than animal quartets with a typical horizontal cleavage plane. The increase in the frequency seen in simulated weightlessness animal quartets was not due to their increased size. Fusing two animal quartets isolated from hypergravity (3g) exposed embryos (small blastomeres and low incidence of protrusions) did not affect the frequency of protrusion formation. Molecular analyses revealed that a partial induction was associated with the protrusion formation. Transcripts of the dorsal lip specific homeobox gene, goosecoid, and alpha-cardiac actin were detectable by PCR amplification in the animal quartet with a protrusion, and alpha-cardiac actin mRNA was found by whole-mount in situ hybridization to be localized in the protrusion. Taken together, all these results are consistent with the notion that both animal and vegetal information is necessary for normal development and the partitioning of morphogenetic information into animal quartets results in gravity-dependent differential morphogenesis and gene regulation.

Actins↗
PubMed2001

Finite element tension analysis of the supporting tissues of a maxillary canine.

INTRODUCTION: The distribution of masticatory load on the teeth and the arising force tensions in them are factors that determine the origine of destructive processes in their periodontium. The development of mathematical models and application of new computer technologies make possible their precise study. They are still not thoroughly studied. PURPOSE: To study the tensions, originating in the periodontium of a canine tooth during occlusal load by the modern method of finite elements (MFE). MATERIALS AND METHODS: A three-dimensional model of a maxillary canine is built by MFE containing 304 finite elements with six varieties of geometrical form, linked in 1409 nodes. It is supposed that the tooth is fixed firmly to the outer surface of the periodontal membrane to the alveolar bone and is loaded in the lingual wall by a force perpendicular to its longitudinal axis and directed from the lingual to the vestibular wall. RESULTS: As a result of the calculations according to MFE the tension state of dental tissues is calculated for diferent degrees of destruction of the alveolar bone. It was established that with the increase of destruction of the alveolar bone for one and the same masticatory load, the tensions in the periodontal membrane also increase. The maximal tensions act in the apex of the root and around the clinical neck of the teeth. CONCLUSION: The results obtained provide precise information of distribution of force tensions in the periodontium of maxillary canines during occlusal load. They serve as a serious theoretical base for future investigations.

Cuspid↗