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 1,369 records · Page 76Linked to original sources
PubMed2004

Impact of a program to provide patients with comparative information about providers of durable medical equipment for home respiratory care.

BACKGROUND: How patients are informed regarding their choices of durable medical equipment (DME) providers for home-going respiratory equipment may affect their decisions about which vendor to use. When a new enhanced information program to inform home-going patients about all available respiratory DME providers was implemented, we hypothesized that patients' utilization of providers would change and that satisfaction with service would be enhanced. METHODS: The enhanced information program consisted of offering detailed descriptions of the many available providers to home-going patients. To characterize available providers, we administered a questionnaire to all respiratory DME providers listed in our area. We assembled information about the scope of services, the number and types of providers, the geographic range of service, and the providers' contact information, on a 1-page information sheet about the DME providers, which was given to all home-going patients. Case managers, who routinely help patients make such DME arrangements, were oriented about the questionnaire and given the information sheets to distribute. The study compared responses from Medicare insurees prescribed to receive home-going respiratory care equipment on discharge from The Cleveland Clinic Hospital during the periods before and after implementing the enhanced information program. Consecutive eligible patients in the before and after groups were called by two of the study investigators (ERH, DAM), at least 2 weeks after discharge, and, on their granting consent, were asked to complete a telephone survey. RESULTS: Responses were available from 75 patients in each group. Both before and after implementing the enhanced information program, patients' satisfaction with their respiratory DME service providers' services was high. The number of providers selected increased after the program from 12 to 18, and though the differences between the before and after scores were not statistically significant, there was a trend toward prompter visits to patients in their homes by DME-provider respiratory therapists. CONCLUSIONS: The enhanced information program was associated with a larger number of DME providers being selected, with preservation of a high level of patient satisfaction with DME services. The trend toward prompter respiratory therapists' visits to the home and better availability of oxygen canisters for at-home patients suggested benefits from the enhanced information program.

Aged↗
PubMed1976

Multielement and automated radiochemical separation procedures for activation analysis.

In recent years the demand for information about the distribution of elements at trace concentration levels in high purity materials and in biological, environmental and geological specimens has increased greatly. Neutron activation analysis can play an important role in obtaining the required information. Radiochemical separations are required in many of the applications mentioned. A critical review of the progress made over the last 15 years in the development and application of radiochemical separation schemes for multielement activation analysis and in their automation is presented. About 80 radiochemical separation schemes are reviewed. Advantages and disadvantages of the automation of radiochemical separations are critically analysed. The various machines developed are illustrated and technical suggestions for the development of automated machines are given.

Activation Analysis↗
PubMedDate not supplied

Chemical descriptors with distinct levels of information content and varying sensitivity to differences between selected compound databases identified by SE-DSE analysis.

Analysis of the variability of molecular descriptors in large compound databases has recently been carried out using both the Shannon entropy (SE) and differential Shannon entropy (DSE) concepts that reduce descriptor distributions to their information content (SE analysis) and detect intrinsic differences between descriptor settings in compound databases (DSE analysis). Here it is shown that a combination of SE and DSE calculations, termed SE-DSE analysis, makes it possible to identify molecular descriptors most sensitive to systematic differences in databases consisting of synthetic, drug-like, and natural molecules. Descriptors with consistently high information content are detected, and database-specific differences are quantified. Different sets of only very few descriptors were found to be most responsive to principal differences between synthetic, natural, and drug-like molecules. Descriptors with DSE values furthest away from zero are likely to best distinguish between compounds with different characteristics. SE-DSE analysis also reveals that a number of descriptors are not sensitive to compound class-specific features, despite their complexity and consistently high information content.

Journal Article↗
PubMed2006

Anatomic characterization of human ultra-weak photon emission with a moveable photomultiplier and CCD imaging.

Ultra-weak photon emission of a living system has received scientific attention because of its potential for monitoring oxidative metabolism and oxidative damage to tissues. Heretofore, most studies have focused only on the emission from hands. The data regarding emission from other anatomic locations are limited. A previous multi-anatomic site recording of four subjects quantitatively demonstrated that the emission from several corresponding anatomic locations could differ by as much as a factor of 4. The data also suggested a "common" anatomic emission percentage distribution pattern. This information raised the question whether such a typical anatomic percentage emission exists. The objective of the present paper is to systematically replicate the emission from identical anatomic locations to document whether the anatomic percentage distribution pattern is generic. Part 1 includes the recording of ultra-weak photon emission from one sample subject over the torso, head and upper extremities with a highly sensitive charge-coupled device (CCD). Part 2 includes the analysis of that data to select a series of anatomic locations that were subsequently studied with a group of 20 subjects utilizing a highly sensitive, cooled and moveable (in three directions) photomultiplier system. Total sum emission of all recorded anatomic locations per subject fluctuates in this study almost 5-fold between subjects. However, the contribution of each anatomic location to the total emission from each subject was approximately the same percentage for each subject and similar to the sample CCD subject. The deviation of the anatomic percentage contribution for each subject was also established. The study presents evidence that there is a "common" anatomic percentage distribution pattern of ultra-weak photon emission for corresponding locations from each subject.

Adult↗
PubMed2005

Estimating the probability of freedom of classical swine fever virus of the East-Belgium wild-boar population.

A report of the Scientific Committee on Animal Health and Animal Welfare of the European Commission (CEC, 1999.) includes recommendations for setting up monitoring programmes for classical swine fever (CSF) infection in a wild-boar population, based on the assumption that one would detect at least 5% prevalence in a CSF-infected wild-boar population. This assumption, however, is not science based. We propose an alternative method to provide evidence for a wild-boar population being free of CSF and evaluate the efficiency of a surveillance programme that was implemented in Belgium in 1998. In our study, the probability of freedom of CSF-virus was estimated based on 789 samples; these were collected from wild-boars within the surveillance programme (within the three provinces which include 95% of the Belgian wild-boar population) and examined by three diagnostics methods (antibody detection, virus detection and virus RNA detection). A Bayesian framework was used for the estimation, accounting for the diagnostic test characteristics without the assumption of the presence of a gold standard. The median probability of freedom of CSF-virus was estimated at 0.970, with a 95% credibility interval of 0.149-1.000. Independent on the choice of the prior information, the posterior distributions for the probability of freedom of CSF-virus were always skewed close to the upper boundary of 1. This represents a big gain of knowledge since we did not use any prior information for the probability of freedom of CSF-virus and took the uncertainty about the accuracy of the diagnostic methods into account.

Animals↗
PubMed2003

Redundancy of phase-space distribution functions in complex field recovery problems.

Shows that the amplitude and phase of an optical field can be recovered from only a section of phase-space distribution functions, the information contained in other sections being redundant. Experimental implications of this result are discussed, and a physical interpretation of it is offered. In particular the sampling problem in tomography is solved for any field distribution.

Journal Article↗
PubMed2006

Photon counting statistics for blinking CdSe-ZnS quantum dots: a Lévy walk process.

We analyze photon statistics of blinking CdSe-ZnS nanocrystals interacting with a continuous wave laser field, showing that the process is described by a ballistic Lévy walk. In particular, we show that Mandel's Q parameter, describing the fluctuations of the photon counts, is increasing with time even in the limit of long time. This behavior is in agreement with the theory of Silbey and co-workers (Jung et al. Chem. Phys. 2002, 284, 181), and in contrast to all existing examples where Q approaches a constant, independent of time in the long time limit. We then analyze the distribution of the time averaged intensities, showing that they exhibit a nonergodic behavior, namely, the time averages remain random even in the limit of a long measurement time. In particular, the distribution of occupation times in the on-state compares favorably to a theory of weak ergodicity breaking of blinking nanocrystals. We show how our data analysis yields information on the amplitudes of power-law decaying on and off time distributions, information not available using standard data analysis of on and off time histograms. Photon statistics reveals fluctuations in the intensity of the bright state indicating that it is composed of several states. Photon statistics exhibits a Lévy walk behavior also when an ensemble of 100 dots is investigated, indicating that the strange kinetics can be observed already at the level of small ensembles.

Journal Article↗
PubMed2001

Securing interoperability between chip card based medical information systems and health networks.

Health information systems supporting shared care are going to be distributed and interoperable. Dealing with sensitive personal medical information, such information systems have to provide appropriate security services, allowing only authorised users restricted access rights to the patients' data according to the 'need to know' principle. Especially in healthcare, 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. The DIABCARD project aims at 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(2) project, communication and application security services needed are provided like strong authentication as well as the derived services such as authorisation, access control, accountability, confidentiality, etc. The solution is based on Health Professional Cards and Trusted Third Party services. In addition to the secure handling of the patient's chip card and data in DIABCARD workstations, the secure communication between these workstations and related departmental systems has been implemented. Based on the results of this feasibility study, an enhanced security services specification for the DIABCARD example of a CCMIS is provided which will be implemented in the framework of a health network being established in the German federal state Bavaria. Beside the preferred solution of a combination of Patient Identification Card and Patient Data Card, lower level alternatives using card-verifiable certificates are explained in some details. 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 Security↗
PubMed2006

Movement of foraging Tundra Swans explained by spatial pattern in cryptic food densities.

We tested whether Tundra Swans use information on the spatial distribution of cryptic food items (below ground Sago pondweed tubers) to shape their movement paths. In a continuous environment, swans create their own food patches by digging craters, which they exploit in several feeding bouts. Series of short (<1 m) intra-patch movements alternate with longer inter-patch movements (>1 m). Tuber biomass densities showed a positive spatial auto-correlation at a short distance (<3 m), but not at a larger distance (3-8 m). Based on the spatial pattern of the food distribution (which is assumed to be pre-harvest information for the swan) and the energy costs and benefits for different food densities at various distances, we calculated the optimal length of an inter-patch movement. A swan that moves to the patch with the highest gain rate was predicted to move to the adjacent patch (at 1 m) if the food density in the current patch had been high (>25 g/m2) and to a more distant patch (at 7-8 m) if the food density in the current patch had been low (<25 g/m2). This prediction was tested by measuring the response of swans to manipulated tuber densities. In accordance with our predictions, swans moved a long distance (>3 m) from a low-density patch and a short distance (<3 m) from a high-density patch. The quantitative agreement between prediction and observation was greater for swans feeding in pairs than for solitary swans. The result of this movement strategy is that swans visit high-density patches at a higher frequency than on offer and, consequently, achieve a 38% higher long-term gain rate. Swans also take advantage of spatial variance in food abundance by regulating the time in patches, staying longer and consuming more food from rich than from poor patches. We can conclude that the shape of the foraging path is a reflection of the spatial pattern in the distribution of tuber densities and can be understood from an optimal foraging perspective.

Analysis of Variance↗
PubMed1996

Glucagon-like peptide-1 receptor (GLP1-R) mRNA in the rat hypothalamus.

GLP-1 has been shown to dramatically reduce food intake in fasted rats and is thought to exert its effects by modulating neuronal function in the hypothalamus. To date, little is known about the distribution of GLP1-R and its mRNA in the rodent hypothalamus. The purpose of the present study was to utilize in situ hybridization histochemistry to determine the anatomical distribution of GLP1-R mRNA in the rat hypothalamus. The results of these studies revealed an extensive distribution of GLP1-R mRNA throughout the rostral-caudal extent of the hypothalamus; with a dense accumulation of labeled cells in the supraoptic, paraventricular, and arcuate nuclei. Additional labeled cells were also detected in medial and lateral preoptic areas, periventricular nucleus, ventral division of the bed nucleus of the stria terminalis, lateral hypothalamus, and dorsomedial nucleus. The results of these in situ hybridization histochemical studies have provided detailed and novel information about the distribution of GLP1-R mRNA in the rat hypothalamus. In addition, this morphological data provides important information about the neuronal systems modulated by GLP-1 and their potential role in feeding behavior.

Animals↗
PubMed1994

Distribution of the vesicular acetylcholine transporter (VAChT) in the central and peripheral nervous systems of the rat.

Expression of the acetylcholine biosynthetic enzyme choline acetyltransferase (ChAT), the vesicular acetylcholine transporter (VAChT), and the high-affinity plasma membrane choline transporter uniquely defines the cholinergic phenotype in the mammalian central (CNS) and peripheral (PNS) nervous systems. The distribution of cells expressing the messenger RNA encoding the recently cloned VAChT in the rat CNS and PNS is described here. The pattern of expression of VAChT mRNA is consistent with anatomical, pharmacological, and histochemical information on the distribution of functional cholinergic neurons in the brain and peripheral tissues of the rat. VAChT mRNA-containing cells are present in brain areas, including neocortex and hypothalamus, in which the existence of cholinergic neurons has been the subject of debate. The demonstration that VAChT is a completely adequate marker for cholinergic neurons should allow the systematic delineation of cholinergic synapses in the rat nervous system when antibodies directed to this protein are available.

Animals↗
PubMed1997

Distribution of insulin/insulin-like growth factor-I hybrid receptors in human tissues.

Insulin receptors (IR) and type 1 IGF receptors (IGF-IR) have been shown to form insulin/IGF-I hybrid receptors in tissues expressing both molecules. The biological function of hybrid receptors is still undefined. To date there is no information about the distribution of hybrid receptors in human tissues. We have applied two microwell-based immunoassays which are capable of quantitating hybrid receptors in small samples of human tissues and cells. Results demonstrated that the proportion of total IGF-IR assembled as hybrids varied between 40 and 60%, thus indicating that hybrid receptors account for a large fraction of total IGF-I binding in human tissues. A significant fraction of total IR was assembled as hybrids in the tissues examined, varying from 37% in placenta to 45% in hepatoma, with the exception of adipose tissue where the fraction of insulin receptors forming hybrids was 17%. Because hybrid receptors bind IGF-I, but not insulin, with high affinity, it is likely that in human tissues hybrid receptors may be primarily activated by IGF-I rather than insulin under physiological conditions. Therefore, differences in hybrid receptors distribution may contribute to regulate tissue sensitivity to insulin and IGF-I by sequestering insulin receptor alphabeta-heterodimer in an IGF-I responsive form.

Female↗
PubMed2002

Recovery of radial PO(2) profiles from phosphorescence quenching measurements in microvessels.

Work by previous investigators has indicated that a substantial amount of oxygen diffuses from the precapillary circulation. These losses imply that there should be radial gradients of oxygen tension (PO(2)) in arterioles, leading to a non-uniform distribution of oxygen within these microvessels. We have employed the phosphorescence quenching method to measure oxygen, allowing us to evaluate the heterogeneity of PO(2) inside short segments of microvessels. The phosphorescence decay curve contains information about the distribution of oxygen within the excited volume and the distribution can be represented as a histogram, by decomposing the decay curve into several components with weights proportional to the volume fraction of plasma with different PO(2), under the condition of a high signal-to-noise ratio. Furthermore, the histogram can be converted into a radial profile of PO(2), based on the assumptions of a circular vascular lumen, axisymmetric distribution of oxygen and monotonic PO(2) profile. Albumin-bound Pd-porphyrin phosphor was infused into the circulation of hamsters and excited by flash illumination at 10 Hz, with a square region of excitation light just covering the entire lumen, (i.e. width of region equaled luminal diameter) of microvessels in the hamster mesentery. A set of 50 curves (5 s of data) was averaged to obtain a decay curve with low noise. Curves were analyzed with the above histogram procedure, and this analysis allowed us to distinguish between PO(2) values originating from intra and extravascular subvolumes. The intravascular PO(2) in these microvessels was very heterogeneous, which could be explained by the existence of significant radial PO(2) gradients. The radial PO(2) gradients were estimated to be approximately 1 mmHg/microm.

Animals↗
PubMed2006

Unintentional injuries among primary and middle school students in Maanshan City, eastern China.

AIM: To describe the rates and patterns of unintentional injuries among primary and middle school students in China. METHODS: A cross-sectional survey was conducted in Maanshan City of the Anhui Province in eastern China. All students attending six primary and four middle schools, selected randomly, were asked to report unintentional injuries occurring in the 12-mo period before the survey. The occurrence of unintentional injuries that resulted in medical attendance was summarized by study grade, sex, month and external causes. RESULTS: The annual event-based injury rate per 100 students was higher among boys (21.7) than girls (17.6). Only 1.9% of the episodes resulted in hospitalization, and 17.8% resulted in missing school. The most frequent injuries were falls (38.2%) and transportation-related injuries (19.6%). The risk of injury was lower in middle schools than primary schools. Distribution by month of occurrence showed two peaks in boys during spring and autumn, but no clear peak was observed in girls. CONCLUSION: The descriptive epidemiology of unintentional injuries among students in China provides useful information on the distributions in person, place and time, which in turn provide hints for the further exploration of possible risk factors that are important in planning strategies for future prevention.

Accidents↗
PubMed1999

An evaluation of the impact of health worker and patient education on the care and compliance of patients with epilepsy in Zimbabwe.

PURPOSE: The use of primary health care personnel to identify cases of epilepsy and initiate simple treatment protocols has been advocated as a solution to the numeric inadequacy and uneven distribution of medical manpower available for the management of epilepsy in developing countries. This study sought to evaluate the effectiveness of primary health care nurses in the diagnosis and management of epilepsy, as well as the impact of patient-information pamphlets on drug compliance and clinic attendance of patients with epilepsy. METHODS: Primary health care workers from 24 clinics in the Zvimba district in Zimbabwe attended a workshop to improving their knowledge in the diagnosis and management of generalized tonic-clonic seizures. Half of these clinics (experimental group) subsequently received patient-information pamphlets for distribution to patients and relatives, whereas the other half (control group) did not. Frequency of clinic attendance, mean seizure frequencies, and mean serum levels of phenobarbitone were compared at baseline and at 6 months after intervention in patients within each group, and at 6 months after intervention between both groups. RESULTS: Community health worker education led to a 74% increase in patient recruitment as well as a marked improvement in patient drug compliance over the 6-month study period. The use of patient-information pamphlets led to a marked reduction in patient default from clinic follow-up, but did not appear to influence drug compliance or seizure frequency. CONCLUSIONS: The benefits of these simple and inexpensive interventions make a strong case for their widespread implementation for improved epilepsy care not only in Zimbabwe, but also in other developing countries.

Adult↗
PubMed1992

Distribution of Alu and L1 repeats in human YAC recombinants.

Evidence is accumulating that the two major families of interspersed repeated human DNA sequences, Alu and L1, are not randomly distributed. However, only limited information is available on their relative long-range distribution. We have analyzed a set of randomly selected, human Chromosome (Chr) 11-specific YAC recombinants constituting a total length of about 2 Mbp for the local and global distribution of Alu and L1 repeats: the data show a strong asymmetry in the distribution of these two repeat classes and give weight, at the long-range molecular level, to previous studies indicating their partition in the human genome; they also suggest a strong tendency for L1 repeats to cluster, with a higher proportion of full-length elements than expected.

Base Sequence↗
PubMed1997

Heterogeneous blood flow response in the foot on dependency, assessed by laser Doppler perfusion imaging.

The exact nature of the decrease in foot skin blood flow seen after a change in posture remains unsettled. This mechanism has previously been examined by non-invasive techniques such as the laser Doppler perfusion monitor (laser Doppler flowmetry). Taking into account the shortcomings of laser Doppler perfusion monitoring when applied to the determination of skin blood flow, which normally shows substantial heterogeneity, we have applied an emerging technology, the laser Doppler perfusion imager (LDPI). This technique provides a more comprehensive picture of the blood flow distribution in the skin, as it maps skin blood flow over a surface area (120 x 120 mm, 4096 measurement sites). It was used to examine if the reduction in tissue perfusion or the alterations in flow distributions seen after a change in posture (supine to dependency) could be fully explained by an increase in venous pressure (venous stasis of 50 mmHg) or if the data suggest a complementary mechanism. Skin blood flow of the forefoot decreased from 0.60 V (volt) (median) during rest to 0.40 and 0.38 V during venous stasis and dependency, respectively. Although almost identical median values were obtained during stasis and dependency, the flow distributions were different with a loss of high flow values during venous stasis. Biological zero was 0.24 V. As the LDPI technique readily records skin perfusion during variations in venous stasis and posture, as well as information on flow distribution changes. It appears promising for future application in stimuli-response studies of skin blood flow. The difference in flow distribution seen between increased venous pressure and dependency suggests an additive regulatory mechanism to the veni-vasomotor reflex during a change in posture.

Adult↗
PubMed2005

Distributions of scatter-to-primary and signal-to-noise ratios per pixel in digital chest imaging.

The aim of this work was to calculate distributions of scatter-to-primary ratios (epsilon(s)/epsilon(p)) and signal-to-noise ratios per pixel (SNRp) in chest images. Such distributions may provide useful information on how physical image quality (contrast, SNR) is distributed over the posterior/anterior (PA) chest image. A Monte Carlo computer program was used for the calculations, including a model of both the patient (voxel phantom) and the imaging system (X-ray tube, anti-scatter grid and image detector). The calculations were performed for three PA thicknesses 20, 24 and 28 cm. For a 24 cm patient, the epsilon(s)/epsilon(p) varies between 0.5 in the lung to 2.5 behind the spine and heart. The corresponding variation of the SNRp is a factor of 3, with the highest values in the lung. Increasing the patient thickness from 20 to 28 cm increases the epsilon(s)/epsilon(p) by a factor of 2.2 behind the spine and heart.

Computers↗