160 research outputs found

    An IoT and Blockchain-based Approach for Ensuring Transparency and Accountability in Regulatory Compliance

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    Regulatory compliance is an essential exercise in the modern societies confirming safety and prevention of harm to consumers. Despite many efforts from international and national quality control authorities, transparency and accountability in regulatory compliance remain a challenging technical-legal problem sitting atop a heavy reliance on trust. This paper presents a theoretical model of regulatory compliance aiming at improving accountability for systems and data audit and introduces a higher degree of transparency in management and quality control. It explores the technical aspects of two emerging technologies the Internet of Things (IoT) and Blockchain, and using a common use-case in practice shows how to better align these technologies with legal concerns and trust in regulatory compliance

    Cr Isotopic Abundances

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    We have developed techniques for the chemical separation and isotopic analysis of Cr in silicates and spinels. The purpose is to pursue the evidence for correlated isotopic effects in Ca-AI-rich inclusions (CAl) for elements in the vicinity of the Fe-abundance peak. Such a correlation is most striking for Ca and Ti for the FUN inclusions EK-1-4-1 and C-1 (Lee eta/., 1978; Niederer et al., 1980)

    Sm-Nd and Rb-Sr Systematics in Volcanics and Ultramafic Xenoliths From Malaita, Solomon Islands, and the Nature of the Ontong Java Plateau

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    A Rb-Sr and Sm-Nd study was carried out on five ultrabasic inclusions, three alnoite host rocks, and one sample of basalt from Malaita in an effort to determine the isotopic stratigraphy of the mantle in this area. The results of this study show the presence of relatively undepleted mantle segments underlying relatively older depleted upper mantle. The alnoite samples, three megacrysts and one Iherzolite inclusion, and the basalt are relatively uniform isotopically and yielded ε_(Nd) (T) ≈ +3.5 and ε_(Sr) (T) ≈ −6 to +17 (T = 100 m.y. for the basalt and Iherzolite and 34 m.y. for the rest of the samples). It is suggested that a mantle segment of that isotopic composition exists at a depth of more than 100 km. This mantle segment is relatively undepleted. A Iherzolite inclusion with ε_(Nd) (T) = 6.6 is included in the alnoite and indicates the location of a light rare earth element depleted layer overlying a less depleted mantle at a depth of approximately 100 km. The mantle source for the alnoite and basalt cannot be old, depleted oceanic mantle or subducted old continental crust but may come from a relatively young, slightly depleted mantle segment. The isotopic results are compatible with a mixture of about 99% depleted oceanic mantle homogenized with 1% continental crust possibly by metasomatic processes. Such a mixture is only slightly fractionated and has ƒ^(Sm/Nd) ≈ 0.13 and ƒ^(Rb/Sr) ≈ 0. Assuming that the basalt is characteristic of the Ontong Java Plateau, a volume greater than 108 km3 of mantle source with ε_(Nd) ∼ 3.5, ε_(Sr) ∼ 0 was involved. This corresponds to a block of continental crust of ∼ 10^6 km^3 which had to reach a depth greater than 100 km to produce the proposed nearly homogeneous isotopic mixture. Alternatively, the source of the Ontong Java Plateau may be a segment of a type of young continental crust with the appropriate isotopic signature which was subducted below 100 km. This would not require homogenization with a large volume of depleted mantle

    Orthogonal Block Structure and Uniformly Best Linear Unbiased Estimators

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    Models with orthogonal block structure, OBS, have variance covariance matrices that are linear combinations [...]info:eu-repo/semantics/publishedVersio

    Low-Energy 3He(α, γ)7Be Cross-Section Measurements

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    The cross section and branching ratio for 3He(α, γ)7Be have been measured from Ec.m.=165 to 1170 keV by counting prompt γ rays from a windowless, recirculating, 3He gas target. Absolute cross sections were also measured at Ec.m.=945 and 1250 keV by measuring the 7Be activity produced in a 3He gas cell with a Ni entrance foil. The inferred zero-energy intercept is S34(0)=0.52±0.03 keV b. The effect of this extrapolated value on the solar-neutrino problem is discussed

    The Stringent Response and Cell Cycle Arrest in Escherichia coli

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    The bacterial stringent response, triggered by nutritional deprivation, causes an accumulation of the signaling nucleotides pppGpp and ppGpp. We characterize the replication arrest that occurs during the stringent response in Escherichia coli. Wild type cells undergo a RelA-dependent arrest after treatment with serine hydroxamate to contain an integer number of chromosomes and a replication origin-to-terminus ratio of 1. The growth rate prior to starvation determines the number of chromosomes upon arrest. Nucleoids of these cells are decondensed; in the absence of the ability to synthesize ppGpp, nucleoids become highly condensed, similar to that seen after treatment with the translational inhibitor chloramphenicol. After induction of the stringent response, while regions corresponding to the origins of replication segregate, the termini remain colocalized in wild-type cells. In contrast, cells arrested by rifampicin and cephalexin do not show colocalized termini, suggesting that the stringent response arrests chromosome segregation at a specific point. Release from starvation causes rapid nucleoid reorganization, chromosome segregation, and resumption of replication. Arrest of replication and inhibition of colony formation by ppGpp accumulation is relieved in seqA and dam mutants, although other aspects of the stringent response appear to be intact. We propose that DNA methylation and SeqA binding to non-origin loci is necessary to enforce a full stringent arrest, affecting both initiation of replication and chromosome segregation. This is the first indication that bacterial chromosome segregation, whose mechanism is not understood, is a step that may be regulated in response to environmental conditions

    Broken replication forks trigger heritable DNA breaks in the terminus of a circular chromosome

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    <p><u>(A) Circular map of the <i>E</i>. <i>coli</i> chromosome</u>: <i>oriC</i>, <i>dif</i> and <i>terD</i> to <i>terB</i> sites are indicated. Numbers refer to the chromosome coordinates (in kb) of MG1655. (<u>B) Linear map of the terminus region:</u> chromosome coordinates are shown increasing from left to right, as in the marker frequency panels (see Figure 1C for example), therefore in the opposite direction to the circular map. In addition to <i>dif</i> and <i>ter</i> sites, the positions of the <i>parS</i><sub>pMT1</sub> sites used for microscopy experiments are indicated. (<u>C) MFA analysis of terminus DNA loss in the <i>recB</i> mutant</u>: sequence read frequencies of exponential phase cells normalized to the total number of reads were calculated for each strain. Ratios of normalized reads in isogenic wild-type and <i>recB</i> mutant are plotted against chromosomal coordinates (in kb). The profile ratio of the terminus region is enlarged and the profile of the corresponding entire chromosomes is shown in inset. Original normalized profiles used to calculate ratios are shown in <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007256#pgen.1007256.s005" target="_blank">S1 Fig</a>. The position of <i>dif</i> is indicated by a red arrow. The <i>ter</i> sites that arrest clockwise forks (<i>terC</i>, <i>terB</i>, green arrow) and counter-clockwise forks (<i>terA</i>, <i>terD</i>, blue arrow) are shown. <u>(D) Schematic representation of focus loss in the <i>recB</i> mutant:</u> Time-lapse microscopy experiments showed that loss of a focus in the <i>recB</i> mutant occurs concomitantly with cell division in one of two daughter cells, and that the cell that keeps the focus then generates a focus-less cell at each generation. The percentage of initial events was calculated as the percentage of cell divisions that generate a focus-less cell, not counting the following generations. In this schematic representation, two initial events occurred (generations #2 and #7) out of 9 generations, and focus loss at generation #2 is heritable. Panels shown in this figure were previously published in [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007256#pgen.1007256.ref019" target="_blank">19</a>] and are reproduced here to introduce the phenomenon.</p

    Autoantibodies targeting GPCRs and RAS-related molecules associate with COVID-19 severity

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    COVID-19 shares the feature of autoantibody production with systemic autoimmune diseases. In order to understand the role of these immune globulins in the pathogenesis of the disease, it is important to explore the autoantibody spectra. Here we show, by a cross-sectional study of 246 individuals, that autoantibodies targeting G protein-coupled receptors (GPCR) and RAS-related molecules associate with the clinical severity of COVID-19. Patients with moderate and severe disease are characterized by higher autoantibody levels than healthy controls and those with mild COVID-19 disease. Among the anti-GPCR autoantibodies, machine learning classification identifies the chemokine receptor CXCR3 and the RAS-related molecule AGTR1 as targets for antibodies with the strongest association to disease severity. Besides antibody levels, autoantibody network signatures are also changing in patients with intermediate or high disease severity. Although our current and previous studies identify anti-GPCR antibodies as natural components of human biology, their production is deregulated in COVID-19 and their level and pattern alterations might predict COVID-19 disease severity

    Synthesis of the elements in stars: forty years of progress

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