7,356 research outputs found

    A 3D Reconstruction Algorithm for the Location of Foundations in Demolished Buildings

    Get PDF
    The location of foundations in a demolished building can be accomplished by undertaking a Ground Penetrating Radar (GPR) survey and then to use the GPR data to generate 3D isosurfaces of what was beneath the soil surface using image reconstruction. The SIMCA ('SIMulated Correlation Algorithm') algorithm is a technique based on a comparison between the trace that would be returned by an ideal point reflector in the soil conditions at the site and the actual trace. During an initialization phase, SIMCA carries out radar simulation using the design parameters of the radar and the soil properties. The trace which would be returned by a target under these conditions is then used to form a kernel. Then SIMCA takes the raw data as the radar is scanned over the ground and removes clutter using a clutter removal technique. The system correlates the kernel with the data by carrying out volume correlation and produces 3D images of the surface of subterranean objects detected. The 3D isosurfaces are generated using MATLAB software. The validation of the algorithm has been accomplished by comparing the 3D isosurfaces produced by the SIMCA algorithm, Scheers algorithm and REFLEXW commercial software. Then the depth and the position in the x and y directions as obtained using MATLAB software for each of the cases are compared with the corresponding values approximately obtained from original Architect's drawings of the buildings

    Neglected Dimensions of Global Security: The Global Health Risk Framework Commission

    Get PDF
    The world has experienced global health crises ranging from novel influenzas (H5N1 and H1N1) and coronaviruses (SARS and MERS) to the Ebola and Zika viruses. In each case, governments and international organizations seemed unable to react quickly and decisively. Health crises have unmasked critical vulnerabilities— weak health systems, failures of leadership, and political overreaction and underreaction. The Global Health Risk Framework Commission, for which the National Academy of Medicine served as the secretariat, recently set out a comprehensive strategy to safeguard human and economic security from pandemic threats

    On local Fourier analysis of multigrid methods for PDEs with jumping and random coefficients

    Get PDF
    In this paper, we propose a novel non-standard Local Fourier Analysis (LFA) variant for accurately predicting the multigrid convergence of problems with random and jumping coefficients. This LFA method is based on a specific basis of the Fourier space rather than the commonly used Fourier modes. To show the utility of this analysis, we consider, as an example, a simple cell-centered multigrid method for solving a steady-state single phase flow problem in a random porous medium. We successfully demonstrate the prediction capability of the proposed LFA using a number of challenging benchmark problems. The information provided by this analysis helps us to estimate a-priori the time needed for solving certain uncertainty quantification problems by means of a multigrid multilevel Monte Carlo method

    Cis-regulatory control of the SM50 gene, an early marker of skeletogenic lineage specification in the sea urchin embryo

    Get PDF
    The SM50 gene encodes a minor matrix protein of the sea urchin embryo spicule. We carried out a detailed functional analysis of a cis-regulatory region of this gene, extending 440 bp upstream and 120 bp downstream of the transcription start site, that had been shown earlier to confer accurate skeletogenic expression of an injected expression vector. The distal portion of this fragment contains elements controlling amplitude of expression, while the region from −200 to +105 contains spatial control elements that position expression accurately in the skeletogenic lineages of the embryo. A systematic mutagenesis analysis of this region revealed four adjacent regulatory elements, viz two copies of a positively acting sequence (element D) that are positioned just upstream of the transcription start site; an indispensable spatial control element (element C) that is positioned downstream of the start site; and further downstream, a second positively acting sequence (element A). We then constructed a series of synthetic expression constructs. These contained oligonucleotides representing normal and mutated versions of elements D, C, and A, in various combinations. We also changed the promoter of the SM50 gene from a TATA-less to a canonical TATA box form, without any effect on function. Perfect spatial regulation was also produced by a final series of constructs that consisted entirely of heterologous enhancers from the CyIIIa gene, the SV40 early promoter, and synthetic D, C, and A elements. We demonstrate that element C exercises the primary spatial control function of the region we analyzed. We term this a ‘locator’ element. This differs from conventional ‘tissue-specific enhancers’ in that while it is essential for expression, it has no transcriptional activity on its own, and it requires other, separable, positive regulatory elements for activity. In the normal configuration these ancillary positive functions are mediated by elements A and D. Only positively acting control elements were observed in the SM50 regulatory domain throughout this analysis

    A Structural Equation Model of the Factors Influencing British Consumers’ Behaviour towards Animal Welfare

    Get PDF
    Results of national and pan-European consumer surveys and the growth in the demand for so-called “animal friendly” food products suggest that consumers within the European Union show a high level of concern for the welfare of farm animals. This paper analyses the determinants of British consumers’ behaviour towards animal welfare using structural equation models (SEM) with observed and latent variables. SEM is a statistical technique for testing and estimating relationships amongst variables, using a combination of statistical data and qualitative causal assumptions. We used a data set collected in 2005 through face-to-face interviews of 654 consumers in England. We analysed the range of statements in existing literature on consumers’ behaviour towards animal welfare and then used SEM to test and estimate these a priori determinants of behaviour. The models include observed and latent variables representing behaviour (stated purchases of free-range and organic chicken meat) and its underlying determinants (attitudes towards animal welfare and socio-economic factors). The models have an adequate overall fit to the data. The significance tests for the structural equation model on free-range chicken meat purchasing behaviour show socioeconomic group, education, attitudes towards animal welfare, reasons for buying chicken meat, access to information on animal welfare issues, number of children and price as significant determinants. All of these (with the exception of reasons for buying chicken meat) were found significant also in the model on organic chicken meat purchasing behaviour.animal welfare, consumers’ behaviour, structural equation models., Agricultural and Food Policy,

    SpZ12-1, a negative regulator required for spatial control of the territory-specific CyIIIa gene in the sea urchin embryo

    Get PDF
    The CyIIIa cytoskeletal actin gene of the sea urchin Strongylocentrotus purpuratus is activated in late cleavage and expressed exclusively in the aboral ectoderm territory of the embryo. Previous gene transfer studies defined a 2.3 kb cis-regulatory region that is necessary and sufficient for correct temporal and spatial expression of a CyIIIa. CAT fusion gene. In this paper, a negative regulatory element within this region was identified that is required for repression of the CyIIIa gene in skeletogenic mesenchyme cells. The repression mediated by this regulatory element takes place after initial territorial specification. A cDNA clone encoding a DNA-binding protein with twelve Zn fingers (SpZ12-1) was isolated by probing an expression library with this cis-element. Deletion analysis of the SpZ12-1 protein confirmed that a DNA-binding domain is located within the Zn finger region. SpZ12-1 is the only DNA-binding protein in embryo nuclear extract that interacts with the specific cis-target sites required for repression of CyIIIa.CAT in skeletogenic mesenchyme and is likely to be the trans factor that mediates this repression

    Association of Mindful Parenting Dimensions, Positive Parenting, Child Reactivity, and Parent Stress

    Get PDF
    The quality of caregiver-child interactions influences child, parent, and family wellness. Although the existing body of literature links mindfulness to positive outcomes within the family, little is known about how specific dimensions of mindful parenting are associated with parenting practices or child behavior reactivity. Based on a mindful parenting model and differential susceptibility model, this quantitative study used an online survey method to examine how specific dimensions of mindful parenting are associated with parenting practices and child behavior reactivity among a sample of 152 parents of elementary-age children. This study also explored how parent life stress modifies the relationship between mindful parenting dimensions and parenting practices and child reactivity. A model estimation was calculated using least squares regression-based path analysis to test the strength and direction of the association between the 5 dimensions of mindfulness and child behavioral reactivity through mediation and moderated mediation models. Results revealed that the mindful parenting dimensions of acceptance and attention had significant positive associations with child behavior reactivity. Emotional awareness and attention were mediated by positive parenting; however, no moderated mediation of any dimension of mindfulness and child behavior reactivity was found. The results from this study may be used to promote positive social change by helping service providers develop effective parenting programs and properly identify parents who might benefit from mindfulness interventions and stress reduction techniques

    Assessing Economic and Environmental Impacts of Ethanol Production on Fertilizer Use in Corn Production

    Get PDF
    The share of corn used in ethanol production has been growing rapidly. USDA predicts that more than 30 percent of the corn crop will be used for ethanol production in 2009/2010. Expanded corn acreage contributes to the application of more fertilizer and is likely to introduce a larger volume of nutrients into the environment. This study found that an increase in ethanol production is consistent with a significant increase in quality-adjusted fertilizer use in selected corn states.quality-adjusted fertilizer, corn production, ethanol, excess nutrients, Crop Production/Industries, Environmental Economics and Policy,
    corecore