183 research outputs found

    Application of GPR in urban utility detection ranging and characterization

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    Keeping track of underground utilities through maps or real physical signs is essential for their maintenance and quick repairs, whenever required, without causing much obstruction to day to day life. It is not uncommon that maps are misplaced or real physical signs are destroyed. In such situations, digging and excavation becomes unavoidable during repair works. Ground penetrating radar (GPR) is one of the non invasive methods which now are being applied for detection, ranging and characterization of subsurface buried objects. GPR employs radar pulses, sends them into ground, then get back scattered energy from dielectric discontinuities in the subsurface. Frequency of antennae determine their capacity to detect and resolve the buried objects (depth of penetration is worth a mention). Hence, 400MHz and 200MHz frequency antennae are generally used for utility mapping at shallow depths up to 4 to 5 meters. GPR response to buried objects is very much dependent upon buried object locations, their constituents, their surroundings and antennae properties. It is very crucial to have a database of GPR responses corresponding to various influencing factors over their ranges of variability either by experimental or simulation studies. In the present work, an attempt has been made to generate data so as to know the dependence of GPR responses on changes in the influencing factors. Simulations have been carried out by using exclusive GPR simulation software called GPRMax. Several typical ground scenarios have been simulated and effects of various object, medium and antennae parameters on response of GPR have been studied and relationships have been established between them using response surface method (RSM). Finally, real GPR data has been compared with simulated data and interpreted

    A Web GIS Based Simulation Tool For Coastal Urban Flood Prediction

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    Flooding in urban areas due to heavy rainfall coupled with high tides is a major concern affecting development of coastal cities all over the world. There is a spectrum of models such as 2D distributed flood models to simplified storage cell models using analytical expressions. All such models demand a high level of skill to handle geospatial data making it difficult for decision makers. Thus development of web GIS based hydrological application becomes essential. Traditionally, most web GIS based applications have used conceptual model because of low data requirements and parameter calibrations. In this paper web GIS based integrated flood model has been presented. Both the web GIS server and the associated hydrological model have been indigenously built. The web GIS server has been built using Java, Java Servlet Page, JQuery, HTML and XML technologies while the associated hydrological model has been built in MATLAB language and both are stored on the server side. The data input to the model is from the client-side through web browser. The model is capable of simulation 1D overland flow using mass balance approach, 1D diffusion wave based channel flow model and quasi 2D raster based floodplain model. The study presents a web GIS based urban flood simulation tool for a coastal urban catchment of Navi Mumbai, India. The three main outputs from the tool are a) generation discharge and stage hydrographs at any point along the channel; b) Water level profile plot at any hour of the simulation and c) Flood map animation in case of flooding in channel. The results of the model application indicate that the model can be used as an effective coastal urban flood simulation tool

    Boundary work: becoming middle class in suburban Dar es Salaam

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    Suburban space provides a useful window onto contemporary class practices in Africa, where it is difficult to identify social classes on the basis of income or occupation. In this article I argue that the middle classes and the suburbs are mutually constitutive in the Tanzanian city of Dar es Salaam. Using interviews with residents and local government officials in the city's northern suburbs, I discuss the material and representational practices of middle-class boundary work in relation to land and landscape. If the middle classes do not presently constitute a coherent political-economic force, they are nevertheless transforming the city's former northern peri-urban zones into desirable suburban residential neighbourhoods

    Progress in Alternative Strategies to Combat Antimicrobial Resistance: Focus on Antibiotics

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    Antibiotic resistance, and, in a broader perspective, antimicrobial resistance (AMR), continues to evolve and spread beyond all boundaries. As a result, infectious diseases have become more challenging or even impossible to treat, leading to an increase in morbidity and mortality. Despite the failure of conventional, traditional antimicrobial therapy, in the past two decades, no novel class of antibiotics has been introduced. Consequently, several novel alternative strategies to combat these (multi-) drug-resistant infectious microorganisms have been identified. The purpose of this review is to gather and consider the strategies that are being applied or proposed as potential alternatives to traditional antibiotics. These strategies include combination therapy, techniques that target the enzymes or proteins responsible for antimicrobial resistance, resistant bacteria, drug delivery systems, physicochemical methods, and unconventional techniques, including the CRISPR-Cas system. These alternative strategies may have the potential to change the treatment of multi-drug-resistant pathogens in human clinical settings

    Performance of novel VUV-sensitive Silicon Photo-Multipliers for nEXO

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    Liquid xenon time projection chambers are promising detectors to search for neutrinoless double beta decay (0νββ\nu \beta \beta), due to their response uniformity, monolithic sensitive volume, scalability to large target masses, and suitability for extremely low background operations. The nEXO collaboration has designed a tonne-scale time projection chamber that aims to search for 0νββ\nu \beta \beta of \ce{^{136}Xe} with projected half-life sensitivity of 1.35×10281.35\times 10^{28}~yr. To reach this sensitivity, the design goal for nEXO is \leq1\% energy resolution at the decay QQ-value (2458.07±0.312458.07\pm 0.31~keV). Reaching this resolution requires the efficient collection of both the ionization and scintillation produced in the detector. The nEXO design employs Silicon Photo-Multipliers (SiPMs) to detect the vacuum ultra-violet, 175 nm scintillation light of liquid xenon. This paper reports on the characterization of the newest vacuum ultra-violet sensitive Fondazione Bruno Kessler VUVHD3 SiPMs specifically designed for nEXO, as well as new measurements on new test samples of previously characterised Hamamatsu VUV4 Multi Pixel Photon Counters (MPPCs). Various SiPM and MPPC parameters, such as dark noise, gain, direct crosstalk, correlated avalanches and photon detection efficiency were measured as a function of the applied over voltage and wavelength at liquid xenon temperature (163~K). The results from this study are used to provide updated estimates of the achievable energy resolution at the decay QQ-value for the nEXO design

    Associations of autozygosity with a broad range of human phenotypes

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    In many species, the offspring of related parents suffer reduced reproductive success, a phenomenon known as inbreeding depression. In humans, the importance of this effect has remained unclear, partly because reproduction between close relatives is both rare and frequently associated with confounding social factors. Here, using genomic inbreeding coefficients (F-ROH) for >1.4 million individuals, we show that F-ROH is significantly associated (p <0.0005) with apparently deleterious changes in 32 out of 100 traits analysed. These changes are associated with runs of homozygosity (ROH), but not with common variant homozygosity, suggesting that genetic variants associated with inbreeding depression are predominantly rare. The effect on fertility is striking: F-ROH equivalent to the offspring of first cousins is associated with a 55% decrease [95% CI 44-66%] in the odds of having children. Finally, the effects of F-ROH are confirmed within full-sibling pairs, where the variation in F-ROH is independent of all environmental confounding.Peer reviewe

    Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: A systematic analysis for the Global Burden of Disease Study 2015

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    Background: The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods: We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings: Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation: Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding: Bill & Melinda Gates Foundation
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