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 829 records · Page 46Linked to original sources
PubMed1986

Quantitative analysis of myocardial fibrosis in normals, hypertensive hearts, and hypertrophic cardiomyopathy.

The distribution of fibrosis was studied quantitatively in the entire left ventricular wall of a transverse slice of the heart from 10 necropsy cases of hypertrophic cardiomyopathy, 10 cases of hypertensive heart disease, and 20 normal adults. The percentage area (mean (SD)) of fibrosis in the left ventricular wall in hypertrophic cardiomyopathy (10.5 (4.3)%) was significantly greater than that in hypertensive heart disease (2.6 (1.5)%) or in normal hearts (1.1 (0.5)%). In hypertrophic cardiomyopathy the percentage area of fibrosis was greater (13.1 (4.8)%) in the ventricular septum than in the left ventricular free wall (7.7 (4.2)%) whereas in hypertensive heart disease and normal hearts values in these two areas were similar. The percentage area of fibrosis in the left ventricular free wall (where myocardial fibre disarray was not extensive even in hypertrophic cardiomyopathy) was greater in hypertrophic cardiomyopathy than in hypertensive heart disease. The percentage area of fibrosis correlated with heart weight in hypertensive heart disease, but not in hypertrophic cardiomyopathy. These results suggest that widespread fibrosis in hypertrophic cardiomyopathy cannot be explained by cardiac hypertrophy alone, and that disarray and other factors are also important in pathogenesis. The increase in the percentage area of fibrosis from the outer to the inner third of the left ventricular free wall in hypertrophic cardiomyopathy and in hypertension probably reflected transmural gradients of wall stress and myocardial fibre diameter. Although fibrosis is not specific to hypertrophic cardiomyopathy, its quantification and analysis of its regional distribution provide information that is useful in investigating the pathophysiology of the disorder.

Adolescent↗
PubMed1999

The "Let's Get Alarmed!" initiative: a smoke alarm giveaway programme.

OBJECTIVES: To reduce fires and fire related injuries by increasing the prevalence of functioning smoke alarms in high risk households. SETTING: The programme was delivered in an inner London area with above average material deprivation and below average smoke alarm ownership. The target population included low income and rental households and households with elderly persons or young children. METHODS: Forty wards, averaging 4000 households each, were randomised to intervention or control status. Free smoke alarms and fire safety information were distributed in intervention wards by community groups and workers as part of routine activities and by paid workers who visited target neighbourhoods. Recipients provided data on household age distribution and housing tenure. Programme costs were documented from a societal perspective. Data are being collected on smoke alarm ownership and function, and on fires and related injuries and their costs. RESULTS: Community and paid workers distributed 20,050 smoke alarms, potentially sufficient to increase smoke alarm ownership by 50% in intervention wards. Compared with the total study population, recipients included greater proportions of low income and rental households and households including children under 5 years or adults aged 65 and older. Total programme costs were 145,087 Pounds. CONCLUSIONS: It is possible to implement a large scale smoke alarm giveaway programme targeted to high risk households in a densely populated, multicultural, materially deprived community. The programme's effects on the prevalence of installed and functioning alarms and the incidence of fires and fire related injuries, and its cost effectiveness, are being evaluated as a randomized controlled trial.

Adolescent↗
PubMed1992

Safe sex and women.

OBJECTIVE: Sexual behaviour, condom use, HIV knowledge and anxiety for women were examined to understand the range of sexual behaviours, predictors of safer sex and the extent of relapse. DESIGN: A cross sectional sample of women STD clinic attenders completed interviews and questionnaires. SETTING: Central London STD Clinic. SUBJECTS: 153 women drawn from consecutive attenders at a sexually transmitted disease (STD) clinic in inner London. RESULTS: A quarter of the sample had never responded to safe sex and a further 14% had been unable to maintain it over time. Anxiety and knowledge did not differ between safe and relapsed groups, but self efficacy and cognitive variables did. Those who maintained safe sex had significantly less sex. Ten percent of the sample had unprotected anal intercourse. Most women saw themselves in longer term relationships, yet a quarter had sex outside of the relationship and a fifth stated that their partners also did. HIV information gathering was passive and 74% felt they could not protect themselves against infection. High concern over HIV was monitored. Condom uptake was low and non-existent for anal intercourse. 25% had undergone HIV testing. These women did not differ significantly in terms of their behaviour from the untested women. CONCLUSIONS: HIV risks for women are a source of anxiety and tailored intervention is needed to reduce risk and promote dialogue and negotiation.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Nutrition research with lactic acid bacteria: a retrospective view.

From the above discussion, it is apparent that one or another of the lactic acid bacteria requires each of the B vitamins required by animals and that assay methods developed during study of nutrition of bacteria and yeasts have played a large role in the initial or independent discovery, isolation, and characterization of vitamins, vitamin derivatives, and functionally similar substances. Clear examples include biotin, biocytin, lipoic acid, nicotinic acid, pantothenic acid, pantetheine, folic acid and tetrahydrofolic acid (and their derivatives), pyridoxal, pyridoxamine, and pyridoxamine phosphate. Improved assay methods that use these organisms also have provided much of the currently available information concerning distribution and stability of the vitamins in natural products, while quantitative inconsistencies between assays, when traced to their origin, have frequently revealed previously unknown metabolic precursors, products, or functions of the vitamins and have provided explanations of the mechanisms by which certain peptide growth factors act. Extension of such studies to organisms that cannot yet be grown in media of known composition should provide additional insights into currently obscure areas of nutrition.

Lactobacillus↗
PubMed1994

Effect of myocardial fiber direction on epicardial potentials.

BACKGROUND: Understanding the relations between the architecture of myocardial fibers, the spread of excitation, and the associated ECG signals is necessary for addressing the forward problem of electrocardiography, that is, predicting intracardiac and extracardiac ECGs from known intracardiac activity. So far, these relations have been studied experimentally only in small myocardial areas. In this study, we tested the hypothesis that potential distributions measured over extensive epicardial regions during paced beats reflect the direction of superficial and intramural fibers through which excitation is spreading in both the initial and later stages of ventricular excitation. We also tried to establish whether the features of the epicardial potential distribution that correlate with fiber direction vary as a function of pacing site, intramural pacing depth, and time elapsed after the stimulus. An additional purpose was to compare measured epicardial potentials with recently published numerical simulations depicting the three-dimensional spread of excitation in the heart muscle and the associated potential fields. METHODS AND RESULTS: The hearts of 18 mongrel dogs were exposed and 182 to 744 unipolar electrograms were recorded from epicardial electrode arrays (2.3 x 3.0 to 6.5 x 6.5 cm). Hearts were paced at various intramural depths through an intramural needle. The overall number of pacing sites in 18 dogs was 241. Epicardial potential distributions, electrographic waveforms, and excitation time maps were displayed, and fiber directions in the ventricular wall underlying the electrodes were determined histologically. During the early stages of ventricular excitation, the position of the epicardial maxima and minima revealed the orientation of myocardial fibers near the pacing site in all cases of epicardial and intramural pacing and in 60% of cases of endocardial or subendocardial pacing. During later stages of propagation, the rotation and expansion of the positive areas correlated with the helical spread of excitation through intramurally rotating fibers. Marked asymmetry of potential patterns probably reflected epicardial-endocardial obliqueness of intramural fibers. Multiple maxima appeared in the expanding positive areas. CONCLUSIONS: For 93% of pacing sites, results verified our hypothesis that epicardial potential patterns elicited by ventricular pacing reflect the direction of fibers through which excitation is spreading during both the initial and later stages of propagation. Epicardial potential distributions provided information on the site of origin and subsequent helical spread of excitation in an epicardial-endocardial, endocardial-epicardial, or double direction. Results were in agreement with previously published numerical simulations except for the asymmetry and fragmentation of the positive areas.

Animals↗
PubMed2000

The representation of objects in the human occipital and temporal cortex.

Recently, we identified, using fMRI, three bilateral regions in the ventral temporal cortex that responded preferentially to faces, houses, and chairs [Ishai, A., Ungerleider, L. G., Martin, A., Schouten, J. L., & Haxby, J. V. (1999). Distributed representation of objects in the human ventral visual pathway. Proceedings of the National Academy of Sciences, U.S.A., 96, 9379--9384]. Here, we report differential patterns of activation, similar to those seen in the ventral temporal cortex, in bilateral regions of the ventral occipital cortex. We also found category-related responses in the dorsal occipital cortex and in the superior temporal sulcus. Moreover, rather than activating discrete, segregated areas, each category was associated with its own differential pattern of response across a broad expanse of cortex. The distributed patterns of response were similar across tasks (passive viewing, delayed matching) and presentation formats (photographs, line drawings). We propose that the representation of objects in the ventral visual pathway, including both occipital and temporal regions, is not restricted to small, highly selective patches of cortex but, instead, is a distributed representation of information about object form. Within this distributed system, the representation of faces appears to be less extensive as compared to the representations of nonface objects.

Adult↗
PubMed1998

A Potts Neuron Approach to Communication Routing.

A feedback neural network approach to communication routing problems is developed, with emphasis on multiple shortest path problems, with several requests for transmissions between distinct start and end nodes. The basic ingredients are a set of Potts neurons for each request, with interactions designed to minimize path lengths and prevent overloading of network arcs. The topological nature of the problem is conveniently handled using a propagator matrix approach. Although the constraints are global, the algorithmic steps are based entirely on local information, facilitating distributed implementations. In the polynomially solvable single-request case, the approach reduces to a fuzzy version of the Bellman-Ford algorithm. The method is evaluated for synthetic problems of varying sizes and load levels, by comparing to exact solutions from a branch-and-bound method, or to approximate solutions from a simple heuristic. With very few exceptions, the Potts approach gives high-quality legal solutions. The computational demand scales merely as the product of the numbers of requests, nodes, and arcs.

Journal Article↗
PubMed1997

Quantitative international migration data for Thailand: an overview.

"This paper reviews the main characteristics of migration data for movements into and out of Thailand. It considers only international migration and it covers the following areas: (1) who collects and disseminates international migration data for Thailand; (2) what sorts of data are available; and (3) what are the major characteristics of these data. It is designed as a guide for persons using Thai migration data to help them interpret these data more clearly.... The paper concludes with some brief suggestions about how to improve migration data collection and dissemination in Thailand."

Asia↗
PubMed2000

Evaluation of a drama-in-education programme to increase AIDS awareness in South African high schools: a randomized community intervention trial.

A community intervention trial was undertaken in KwaZulu Natal, South Africa to evaluate the effectiveness of a high school drama-in-education programme. Seven pairs of secondary schools were randomized to receive either written information about HIV/AIDS or the drama programme. Questionnaire surveys of knowledge, attitude and behaviour were compared before and 6 months after the interventions. One thousand and eighty students participated in the first survey and 699 in the second. Improvements in knowledge (P=0.0002) and attitudes (P < 0.00001) about HIV/AIDS were demonstrated in pupils at schools receiving the drama programme when compared to pupils receiving written information alone. These changes were independent of age, gender, school or previous sexual experience. In schools receiving the drama programme, sexually active pupils reported an increase in condom use (P < 0.01). It is important to provide resources to sustain such programmes and to obtain stronger evidence of effect on behaviour by measuring changes in HIV incidence.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Early individualization of tricyclic antidepressant dosing using a Bayesian pharmacokinetic model.

Existing methods to prospectively dose tricyclic antidepressants (TCAs) require either specific test doses, precisely timed serum sampling, or both. We prospectively tested a new pharmacokinetic model that allows flexible dosing and sampling to determine maintenance requirements in patients receiving TCAs. Thirty-four patients entered the study. Drug concentrations were measured on the third day after starting TCA therapy. These values were analyzed using a Bayesian pharmacokinetic model to determine drug clearance and volume of distribution. This information was then used to predict the serum concentration resulting from a maintenance dose chosen by the psychiatrist. In phase I (n = 17), patients received imipramine without specific starting doses. Phase II (n = 17) was performed to provide a preliminary evaluation of the method in the usual clinical environment. In this phase, patients received either amitriptyline, imipramine, desipramine, doxepin (75 mg on day 1,100 mg on day 2), or nortriptyline (50 mg on day 1, 75 mg on day 2). Lower doses were allowed if clinically indicated. The predictability of future serum concentrations was then compared between the two phases. The mean prediction errors (model bias) in phases I and II were -15.5 +/- 27.3 and -12.3 +/- 21.8 ng/mL and were not different (p greater than 0.05). The absolute prediction errors (model precision) were 18.5 +/- 25.1 and 18.8 +/- 16.0 ng/mL and were not different (p greater than 0.05). Two slow metabolizers were identified (clearance less than 0.10 L/kg/h). This new method allows the determination of maintenance dose requirements early in therapy without standard test doses or specifically timed serum sampling.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Ghana social mobilization analysis.

In order to increase communication channels for child survival and development, the government and UNICEF Ghana undertook a "social mobilization analysis." This analysis included three studies that aimed to identify individuals and existing organizations with the potential to serve as health communicators and to determine the type of assistance that they needed to maximize their effectiveness in this role. The first study surveyed governmental institutions, trade unions, revolutionary organizations, traditional leaders, and others and found a largely untapped reservoir of capacities to promote child health, with varying levels of current involvement. The primary need identified was for information and training materials. The second study focused on the mass media and revealed a low coverage of maternal and child health topics and the need for better cooperation between journalists and health professionals. The third study assessed sources of health information for parents and found several sources, such as religious organizations, women's groups, and school teachers that could be mobilized to promote child health. Recommendations are made for the use of the findings.

Attitude to Health↗
PubMed1996

Analysis of the double occlusion which provides four pressure gradients.

The arterial, double and venous occlusions are used to partition pulmonary vascular resistance into four segments. In this study, we tested whether the same can be accomplished from one double occlusion. In an isolated canine lung left lower lobe perfused with blood (flow rate = 500 mL.min-1), the pulmonary arterial and venous pressures (Pa and Pv, respectively) were measured directly. Arterial, double, and venous occlusions were performed and analysed as usual (Method 1) to measure pressures in small arteries and small veins (Pa' and Pv', respectively) and capillary pressure (Pc). Alternatively, one double occlusion was analysed (Method 2), not only for Pa, Pv and Pc, but also as independent arterial and venous occlusions to measure Pa' and Pv'. Method 1 yielded Pa, Pa', Pc, Pv', and Pv (Baseline) of 14.2 +/- 1.7, 10.8 +/- 1.6, 8.9 +/- 1.9, 7.3 +/- 1.5 and 1.3 +/- 0.6 mmHg, respectively (1 mmHg = 0.133 kPa). Method 2 yielded values for the same five pressures equal to 14.7 +/- 2.1, 11.0 +/- 2.2, 8.9 +/- 1.9, 7.3 +/- 1.3 and 1.3 +/- 0.6 mmHg, respectively. There was no significant difference in the pressure profile obtained using the two methods, nor were there differences during hypoxia and angiotensin infusion. These results suggest that a more thorough analysis of the double occlusion can provide the same information about distribution of vascular resistance as provided by a combination of the three occlusions. The advantage of the new approach is that fewer occlusions are needed and resistance distribution can be assessed during a transient response. Because all pressures are derived from one occlusion, the pressures would be more accurate relative to each other.

Animals↗
PubMed2005

Targeted oligonucleotide-mediated microsatellite identification (TOMMI) from large-insert library clones.

BACKGROUND: In the last few years, microsatellites have become the most popular molecular marker system and have intensively been applied in genome mapping, biodiversity and phylogeny studies of livestock. Compared to single nucleotide polymorphism (SNP) as another popular marker system, microsatellites reveal obvious advantages. They are multi-allelic, possibly more polymorphic and cheaper to genotype. Calculations showed that a multi-allelic marker system always has more power to detect Linkage Disequilibrium (LD) than does a di-allelic marker system. Traditional isolation methods using partial genomic libraries are time-consuming and cost-intensive. In order to directly generate microsatellites from large-insert libraries a sequencing approach with repeat-containing oligonucleotides is introduced. RESULTS: Seventeen porcine microsatellite markers were isolated from eleven PAC clones by targeted oligonucleotide-mediated microsatellite identification (TOMMI), an improved efficient and rapid flanking sequence-based approach for the isolation of STS-markers. With the application of TOMMI, an average of 1.55 (CA/GT) microsatellites per PAC clone was identified. The number of alleles, allele size distribution, polymorphism information content (PIC), average heterozygosity (HT), and effective allele number (NE) for the STS-markers were calculated using a sampling of 336 unrelated animals representing fifteen pig breeds (nine European and six Chinese breeds). Sixteen of the microsatellite markers proved to be polymorphic (2 to 22 alleles) in this heterogeneous sampling. Most of the publicly available (porcine) microsatellite amplicons range from approximately 80 bp to 200 bp. Here, we attempted to utilize as much sequence information as possible to develop STS-markers with larger amplicons. Indeed, fourteen of the seventeen STS-marker amplicons have minimal allele sizes of at least 200 bp. Thus, most of the generated STS-markers can easily be integrated into multilocus assays covering a broader separation spectrum. Linkage mapping results of the markers indicate their potential immediate use in QTL studies to further dissect trait associated chromosomal regions. CONCLUSION: The sequencing strategy described in this study provides a targeted, inexpensive and fast method to develop microsatellites from large-insert libraries. It is well suited to generate polymorphic markers for selected chromosomal regions, contigs of overlapping clones and yields sufficient high quality sequence data to develop amplicons greater than 250 bases.

Alleles↗
PubMed2004

APC: the toll road to continued high quality communication.

In this article we briefly review the reasons and advantages that underly our publisher's decision to introduce article-processing charges (APC) for manuscripts submitted to Cell Communication and Signaling. The charge is an attempt to develop a new business model for distributing biomedical information and has been accepted in a number of other journals. APCs will enable BioMed Central to continue to provide their excellent service and will help to establish our journal.

Journal Article↗
PubMed2025

Climatic data sources and limitations of ecological niche models impact the estimations of historical ranges and niche overlaps in distantly related Korean salamanders.

BACKGROUND: Ecological niche models (ENMs) and analyses of niche overlap/divergence have become popular methods in ecology and evolutionary biology. These analyses rely on environmental data available from several databases. However, the influence of data sources on these analyses is rarely tested. Here, we test the impact of climatic data choice on the prediction of current and Plio-Pleistocene suitable habitats for two distantly related, but broadly sympatric, salamanders endemic to the Korean Peninsula. We ran MaxEnt separately on WorldClim and CHELSA climate data. We then hindcasted ENMs to five time periods of the Plio-Pleistocene, bracketing the estimated intraspecific divergence times for these species. We then quantified the differences in predictions between WorldClim- and CHELSA-based models. Also, given the sympatry and similar habitat requirements of the two species, we tested for niche overlaps using niche identity and background tests and tested the sensitivity of the results to climatic data choice. RESULTS: The ENMs successfully predicted contemporary suitable habitats for the two species. However, the predictions were highly sensitive to climatic data choice as well as variable combinations. The hindcasted ENMs produced contrasting predictions depending on the choice of climatic dataset and failed to predict suitable habitats for some Pleistocene time periods regardless of the climatic data choice. The niche analyses were also sensitive to climatic data choice, with results suggesting either niche overlaps or divergence depending on the climatic dataset used for the analyses. CONCLUSIONS: Our study highlights the influence of climatic data choice on the outcomes of ENMs and niche analyses. Our results also underscore the limitations of macroclimate-based ENMs, especially when the species is likely buffered from macroclimatic changes by microhabitat. We argue for the need for additional ecological, ecophysiological, and population genomic studies to better understand the range formation of these enigmatic species.

Animals↗