107 research outputs found

    A test-bed simulator for gps and gis integrated navigation and positioning research: - bus positioning, using gps observations, odometer readings and map matching

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    A test-bed application, called Map Matched GPS (MMGPS) processes raw GPS output data, from RINEX files, or GPS derived coordi nates. This developed method uses absolute GPS positioning, map matched, to locate the vehicle on a road centre-line, when GPS is known to be sufficiently accurate. MMGPS software has now been adapted to incorporate positioning based on odometer derived dist ances (OMMGPS), when GPS positions are not available. Relative GPS positions are used to calibrate the odometer observations. In OMMGPS, GPS pseudorange observations are combined with DTM height information and odometer positions to provide a vehicle position at one second epochs. Generally, odometer positioning is used much more often, to position the vehicle, than GPS. Typically the ratio is 7:3 odometer positions to GPS pos itions. In total, over 15,000 vehicle positions were computed using OMMGPS. The described experiment used GPS observations taken on a bus on a predefined route, hence the correct road is always known. Ther efore, map matching techniques are used to improve the GPS positioning accuracy, and to identify grossly inaccurate GPS positions. Calibrated odometer corrections are made using odometer count at the current epoch and relative GPS distance travelled. If a GPS position is detected to be inaccurate, it is not used for positioning the bus, or for calibrating the odometer correction factor. In general the position quality provided by GPS alone was extremely poor, due to multipath effects caused by the urban canyons of central London. In the case of one particular trip, OMMGPS provides a mean error of position of 8.8 metres compared with 53.7 metres for raw GPS alone

    Teen, Parent, and Clinician Expectations About Obesity and Related Conditions During the Annual Well-Child Visit

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    Purpose: This study aimed to examine family (patient, parent/guardian) and clinician preferences for identification and management of obesity and obesity-related conditions during the well-child visit. Methods: Four focus groups with teen patients (n = 16), four focus groups with parents (n = 15) and one focus group with providers (n = 12) were conducted using a structured moderator guide tailored to each population. Eligible patients had a well-child visit during the past 12 months and a diagnosis of overweight, obesity, hyperlipidemia or elevated blood pressure. Parents who attended their child’s well-child visit and whose child met the diagnostic criteria were eligible. Teen focus groups were divided by gender (male/female) and age (14–15/16–17 years). Focus group transcripts were coded for concepts and themes using qualitative data and thematic analysis. Analysis was performed across groups to determine common themes and domains of intersect. Results: Teens and parents expect weight to be discussed at well-child visits and prefer discussions to come from a trusted clinician who uses serious, consistent language. Teens did not recognize the health implications from excess weight, and both parents and teens express the need for more information on strategies to change behavior. Providers recognize several challenges and barriers to discussing weight management in the well-child visit. Conclusions: A clinician-teen-family relationship built on trust, longevity, teamwork, support and encouragement can create a positive atmosphere and may improve understanding for weight-related messages for teens and families during a well-child visit

    Optimising large scale public transport network design problems using mixed-mode parallel multi-objective evolutionary algorithms

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    In this paper we present a novel tool, using both OpenMP and MPI protocols, for optimising the efficiency of Urban Transportation Systems within a defined catchment, town or city. We build on a previously presented model which uses a Genetic Algorithm with novel genetic operators to optimise route sets and provide a transport network for a given problem set. This model is then implemented within a Parallel Multi-Objective Genetic Algorithm and demonstrated to be scalable to within the scope of real world, [city-wide], problems. This paper compares and contrasts three methods of parallel distribution of the Genetic Algorithm's computational workload: a job farming algorithm and two variations on an ‘Islands’ approach. Results are presented in the paper from both single and mixed mode strategies. The results presented are from a range of previously published academic problem sets. Additionally a real world inspired problem set is evaluated and a visualisation of the optimised output is given

    Location-specific immunodetection of cocaine on banknotes

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    A novel in-gel bioanalytical immunodetection method has been developed to determine both the presence and the location of cocaine on the surface of banknotes. The cocaine was ‘fixed’ to the surface of the banknote via a coating of a polyacrylamide gel matrix. Immunostaining of the immobilised cocaine on the banknote surface was performed using an anti-cocaine primary antibody, either pre-labelled with horse radish peroxidase (HRP) or in conjunction with a HRP-labelled secondary antibody. Visualisation of the location of the cocaine was achieved through chemiluminescence imaging of the banknote following application of a chemiluminescent substrate. The novel method was applied to the detection of cocaine on partial and whole banknote samples obtained from general circulation. Newly minted banknotes, with or without spiked cocaine, were used as positive and negative controls, respectively. The results obtained, for the first time, demonstrate the successful location-specific immunostaining of cocaine on banknotes. A preliminary analysis of six UK banknotes, obtained from general circulation, suggests that cocaine can be present at variable locations across the whole of the banknote

    River ecosystem conceptual models and non‐perennial rivers: A critical review

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    Conceptual models underpin river ecosystem research. However, current models focus on continuously flowing rivers and few explicitly address characteristics such as flow cessation and drying. The applicability of existing conceptual models to nonperennial rivers that cease to flow (intermittent rivers and ephemeral streams, IRES) has not been evaluated. We reviewed 18 models, finding that they collectively describe main drivers of biogeochemical and ecological patterns and processes longitudinally (upstream-downstream), laterally (channel-riparian-floodplain), vertically (surface water-groundwater), and temporally across local and landscape scales. However, perennial rivers are longitudinally continuous while IRES are longitudinally discontinuous. Whereas perennial rivers have bidirectional lateral connections between aquatic and terrestrial ecosystems, in IRES, this connection is unidirectional for much of the time, from terrestrial-to-aquatic only. Vertical connectivity between surface and subsurface water occurs bidirectionally and is temporally consistent in perennial rivers. However, in IRES, this exchange is temporally variable, and can become unidirectional during drying or rewetting phases. Finally, drying adds another dimension of flow variation to be considered across temporal and spatial scales in IRES, much as flooding is considered as a temporally and spatially dynamic process in perennial rivers. Here, we focus on ways in which existing models could be modified to accommodate drying as a fundamental process that can alter these patterns and processes across spatial and temporal dimensions in streams. This perspective is needed to support river science and management in our era of rapid global change, including increasing duration, frequency, and occurrence of drying.info:eu-repo/semantics/publishedVersio

    Association of genetic variation with systolic and diastolic blood pressure among African Americans: the Candidate Gene Association Resource study

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    The prevalence of hypertension in African Americans (AAs) is higher than in other US groups; yet, few have performed genome-wide association studies (GWASs) in AA. Among people of European descent, GWASs have identified genetic variants at 13 loci that are associated with blood pressure. It is unknown if these variants confer susceptibility in people of African ancestry. Here, we examined genome-wide and candidate gene associations with systolic blood pressure (SBP) and diastolic blood pressure (DBP) using the Candidate Gene Association Resource (CARe) consortium consisting of 8591 AAs. Genotypes included genome-wide single-nucleotide polymorphism (SNP) data utilizing the Affymetrix 6.0 array with imputation to 2.5 million HapMap SNPs and candidate gene SNP data utilizing a 50K cardiovascular gene-centric array (ITMAT-Broad-CARe [IBC] array). For Affymetrix data, the strongest signal for DBP was rs10474346 (P= 3.6 × 10−8) located near GPR98 and ARRDC3. For SBP, the strongest signal was rs2258119 in C21orf91 (P= 4.7 × 10−8). The top IBC association for SBP was rs2012318 (P= 6.4 × 10−6) near SLC25A42 and for DBP was rs2523586 (P= 1.3 × 10−6) near HLA-B. None of the top variants replicated in additional AA (n = 11 882) or European-American (n = 69 899) cohorts. We replicated previously reported European-American blood pressure SNPs in our AA samples (SH2B3, P= 0.009; TBX3-TBX5, P= 0.03; and CSK-ULK3, P= 0.0004). These genetic loci represent the best evidence of genetic influences on SBP and DBP in AAs to date. More broadly, this work supports that notion that blood pressure among AAs is a trait with genetic underpinnings but also with significant complexit

    A Meta-analysis of Gene Expression Signatures of Blood Pressure and Hypertension

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    Genome-wide association studies (GWAS) have uncovered numerous genetic variants (SNPs) that are associated with blood pressure (BP). Genetic variants may lead to BP changes by acting on intermediate molecular phenotypes such as coded protein sequence or gene expression, which in turn affect BP variability. Therefore, characterizing genes whose expression is associated with BP may reveal cellular processes involved in BP regulation and uncover how transcripts mediate genetic and environmental effects on BP variability. A meta-analysis of results from six studies of global gene expression profiles of BP and hypertension in whole blood was performed in 7017 individuals who were not receiving antihypertensive drug treatment. We identified 34 genes that were differentially expressed in relation to BP (Bonferroni-corrected p<0.05). Among these genes, FOS and PTGS2 have been previously reported to be involved in BP-related processes; the others are novel. The top BP signature genes in aggregate explain 5%–9% of inter-individual variance in BP. Of note, rs3184504 in SH2B3, which was also reported in GWAS to be associated with BP, was found to be a trans regulator of the expression of 6 of the transcripts we found to be associated with BP (FOS, MYADM, PP1R15A, TAGAP, S100A10, and FGBP2). Gene set enrichment analysis suggested that the BP-related global gene expression changes include genes involved in inflammatory response and apoptosis pathways. Our study provides new insights into molecular mechanisms underlying BP regulation, and suggests novel transcriptomic markers for the treatment and prevention of hypertension

    Integration of genome-wide association studies with biological knowledge identifies six novel genes related to kidney function

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    In conducting genome-wide association studies (GWAS), analytical approaches leveraging biological information may further understanding of the pathophysiology of clinical traits. To discover novel associations with estimated glomerular filtration rate (eGFR), a measure of kidney function, we developed a strategy for integrating prior biological knowledge into the existing GWAS data for eGFR from the CKDGen Consortium. Our strategy focuses on single nucleotide polymorphism (SNPs) in genes that are connected by functional evidence, determined by literature mining and gene ontology (GO) hierarchies, to genes near previously validated eGFR associations. It then requires association thresholds consistent with multiple testing, and finally evaluates novel candidates by independent replication. Among the samples of European ancestry, we identified a genome-wide significant SNP in FBXL20 (P = 5.6 × 10−9) in meta-analysis of all available data, and additional SNPs at the INHBC, LRP2, PLEKHA1, SLC3A2 and SLC7A6 genes meeting multiple-testing corrected significance for replication and overall P-values of 4.5 × 10−4-2.2 × 10−7. Neither the novel PLEKHA1 nor FBXL20 associations, both further supported by association with eGFR among African Americans and with transcript abundance, would have been implicated by eGFR candidate gene approaches. LRP2, encoding the megalin receptor, was identified through connection with the previously known eGFR gene DAB2 and extends understanding of the megalin system in kidney function. These findings highlight integration of existing genome-wide association data with independent biological knowledge to uncover novel candidate eGFR associations, including candidates lacking known connections to kidney-specific pathways. The strategy may also be applicable to other clinical phenotypes, although more testing will be needed to assess its potential for discovery in genera
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