2,033 research outputs found

    Food safety, food fraud and food defense: a fast evolving literature

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    Intentional food crime is plural in nature in terms of the types of crime and the differing levels of financial gain. Successful models of food crime are dependent on how well the crime has been executed and at what point, or even if, detection actually occurs. The aim of this paper is to undertake a literature review and critique the often contradictory definitions that can be found in the literature in order to compare and contrast existing food crime risk assessment tools and their application. Food safety, food defense, and food fraud risk assessments consider different criteria in order to determine the degree of situational risk for each criteria and the measures that need to be implemented to mitigate that risk. Further research is required to support the development of global countermeasures, that are of value in reducing overall risk even when the potential hazards may be largely unknown, and specific countermeasures that can act against unique risks

    Proximal Analysis and the Minimal Time Function of a Class of Semilinear Control Systems

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    The minimal time function of a class of semilinear control systems is considered in Banach spaces, with the target set being a closed ball. It is shown that the minimal time functions of the Yosida approximation equations converge to the minimal time function of the semilinear control system. Complete characterization is established for the subdifferential of the minimal time function satisfying the Hamilton–Jacobi–Bellman equation. These results extend the theory of finite dimensional linear control systems to infinite dimensional semilinear control systems

    Mathematically gifted and talented learners: Theory and practice

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    This is an Author's Accepted Manuscript of an article published in International Journal of Mathematical Education in Science and Technology, 40(2), 213-228, 2009, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/00207390802566907.There is growing recognition of the special needs of mathematically gifted learners. This article reviews policy developments and current research and theory on giftedness in mathematics. It includes a discussion of the nature of mathematical ability as well as the factors that make up giftedness in mathematics. The article is set in the context of current developments in Mathematics Education and Gifted Education in the UK and their implications for Science and Technology. It argues that early identification and appropriate provision for younger mathematically promising pupils capitalizes on an intellectual resource which could provide future mathematicans as well as specialists in Science or Technology. Drawing on a Vygotskian framework, it is suggested that the mathematically gifted require appropriate cognitive challenges as well as attitudinally and motivationally enhancing experiences. In the second half of this article we report on an initiative in which we worked with teachers to identify mathematically gifted pupils and to provide effective enrichment support for them, in a number of London Local Authorities. A number of significant issues are raised relating to the identification of mathematical talent, enrichment provision for students and teachers’ professional development

    Quasi steady state and dynamic hygrothermal performance of fibrous Hemp and Stone Wool insulations: Two innovative laboratory based investigations

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    Moisture and heat management properties of Hemp and Stone Wool insulations were studied by mounting them between a hot and a cold climate chamber. Both insulations were exposed to identical hygrothermal boundary conditions. Quasi steady state and dynamic tests were carried out at a range of relative humidity exposures. The likelihood of interstitial condensation was assessed and equivalent thermal conductivity values of the insulations were determined. The adsorption-desorption isotherms of the insulations were also determined in a dynamic vapour sorption (DVS) instrument. It was observed that the likelihood of condensation was higher in Stone Wool insulation than in Hemp insulation. Hemp insulation performed better in managing moisture due to its high hygric inertia and water absorption capacity. It was observed that the equivalent thermal conductivity of Stone Wool insulation was dependent on enthalpy flow and phase change of moisture. The equivalent thermal conductivity of Hemp insulation was close to its declared thermal conductivity in dynamic conditions when high relative humidity exposures were transient. In quasi steady state boundary conditions, when the insulation was allowed to reach the equilibrium moisture content at ranges of relative humidity, there was a moisture dependent increase of thermal conductivity in Hemp insulation

    The transcriptional repressor protein NsrR senses nitric oxide directly via a [2Fe-2S] cluster

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    The regulatory protein NsrR, a member of the Rrf2 family of transcription repressors, is specifically dedicated to sensing nitric oxide (NO) in a variety of pathogenic and non-pathogenic bacteria. It has been proposed that NO directly modulates NsrR activity by interacting with a predicted [Fe-S] cluster in the NsrR protein, but no experimental evidence has been published to support this hypothesis. Here we report the purification of NsrR from the obligate aerobe Streptomyces coelicolor. We demonstrate using UV-visible, near UV CD and EPR spectroscopy that the protein contains an NO-sensitive [2Fe-2S] cluster when purified from E. coli. Upon exposure of NsrR to NO, the cluster is nitrosylated, which results in the loss of DNA binding activity as detected by bandshift assays. Removal of the [2Fe-2S] cluster to generate apo-NsrR also resulted in loss of DNA binding activity. This is the first demonstration that NsrR contains an NO-sensitive [2Fe-2S] cluster that is required for DNA binding activity

    Mouse Model of Mutated in Colorectal Cancer Gene Deletion Reveals Novel Pathways in Inflammation and Cancer

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    © 2019 The Authors Background & Aims: The early events by which inflammation promotes cancer are still not fully defined. The MCC gene is silenced by promoter methylation in colitis-associated and sporadic colon tumors, but its functional significance in precancerous lesions or polyps is not known. Here, we aimed to determine the impact of Mcc deletion on the cellular pathways and carcinogenesis associated with inflammation in the mouse proximal colon. Methods: We generated knockout mice with deletion of Mcc in the colonic/intestinal epithelial cells (MccΔIEC) or in the whole body (MccΔ/Δ). Drug-induced lesions were analyzed by transcriptome profiling (at 10 weeks) and histopathology (at 20 weeks). Cell-cycle phases and DNA damage proteins were analyzed by flow cytometry and Western blot of hydrogen peroxide–treated mouse embryo fibroblasts. Results: Transcriptome profiling of the lesions showed a strong response to colon barrier destruction, such as up-regulation of key inflammation and cancer-associated genes as well as 28 interferon γ–induced guanosine triphosphatase genes, including the homologs of Crohn's disease susceptibility gene IRGM. These features were shared by both Mcc-expressing and Mcc-deficient mice and many of the altered gene expression pathways were similar to the mesenchymal colorectal cancer subtype known as consensus molecular subtype 4 (CMS4). However, Mcc deletion was required for increased carcinogenesis in the lesions, with adenocarcinoma in 59% of MccΔIEC compared with 19% of Mcc-expressing mice (P =.002). This was not accompanied by hyperactivation of β-catenin, but Mcc deletion caused down-regulation of DNA repair genes and a disruption of DNA damage signaling. Conclusions: Loss of Mcc may promote cancer through a failure to repair inflammation-induced DNA damage. We provide a comprehensive transcriptome data set of early colorectal lesions and evidence for the in vivo significance of MCC silencing in colorectal cancer

    On a Convex Set with Nondifferentiable Metric Projection

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    A remarkable example of a nonempty closed convex set in the Euclidean plane for which the directional derivative of the metric projection mapping fails to exist was constructed by A. Shapiro. In this paper, we revisit and modify that construction to obtain a convex set with smooth boundary which possesses the same property

    Remote physiological monitoring: Clinical, financial, and behavioral outcomes in a heart failure population

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    This article reports on the outcomes associated with remote physiological monitoring (RPM) conducted as part of a heart failure disease management program. Claims data, medical records, data transmission records, and survey results for 91 individuals ages 50–92 (mean 74 years) successfully completing a heart failure RPM program were analyzed for time periods before, during, and after the monitoring intervention. The program was associated with significant reductions in per member per month costs and emergency room and hospital utilization. More detailed analyses were performed for specific gender and age subgroups. Participant surveys indicated high levels of satisfaction, and improvements in self-perceived health status, self-efficacy, and self-management behaviors. This study is the first to assess the impact of a RPM program following removal of the monitoring equipment. The results indicate that RPM, as a component of a traditional disease management program, has a sustained, beneficial effect on participants’ lifestyles after the monitoring period has ended
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