1,023 research outputs found

    Factors driving enterprise adoption of blockchain technology

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    Amidst the rapidly evolving advancement of blockchain technology (BT), enterprises face notable challenges in leveraging its transformative potential, starting with a need to understand the technology and how it can be used for particular applications. Two challenges are that many BT trials have not been successful and large-scale implementations that have led to continued use are scarce. This research provides a comprehensive examination of factors that drive the successful adoption of BT for enterprise use cases. A dual-phased approach was employed. First, I introduce a taxonomy matrix correlating BT design characteristics with use case characteristics, offering a framework for BT design and benefits across different enterprise contexts. Second, I conducted case studies of five successful BT cases in large enterprises that led to the adoption in terms of continued use and contrasted them with one failure case. The data collection and analysis of the case studies encompassed technological, organizational, environmental, and inter-organizational variables that led to BT\u27s continued use. The cross-case analysis revealed that compatibility, relative advantage, and observability are primary technological factors contributing to continued use. Within the organizational dimension, organizational knowledge and internal characteristics emerged as crucial elements, while regulatory compliance came out to be a significant factor. Based on the cross-case analysis, I develop theoretical propositions about the factors that lead to the continued use of BT, which can be further validated and tested in future research

    Genetically induced production of secondary metabolites in Bacillus megaterium

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    Historically, the most important source of new antibiotic drug leads has been small organic compounds made by bacteria. Many antibiotics have been developed into pharmaceutical agents from these molecules (often called secondary metabolites) produced by soil bacteria. Bacillus species are soil bacteria known for producing various antimicrobials including gramicidin, bacitracin, surfactin, and others. Bacillus megaterium is a widely used model gram positive bacterium. Although there has been extensive research on this organism, little is known about its secondary metabolites. We hypothesized that the production of secondary metabolites in this organism could be induced by replacing promoters controlling the expression of genes within the identified clusters. In this study, gene clusters that are predicted to control the production of secondary metabolites were identified using the antiSMASH bioinformatics platform. Phenotypic changes in the secondary metabolite profile of B. megaterium were observed when culture conditions were varied indicating that target metabolites are accessible for chemical analysis. To increase production of targeted secondary metabolites, the native promoter of identified secondary metabolite gene clusters will be replaced by an inducible promoter using plasmid mediated chromosomal integration

    The Serum Concentration of the Calcium Binding Protein S100B is Positively Associated with Cognitive Performance in Older Adults

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    S100B is a calcium binding peptide produced predominantly by astroglial cells in the central nervous system. S100B paradoxically has neurotrophic and apoptotic effects, dependent on extracellular concentration. This study investigated the relationship between serum S100B levels and neuropsychological performance across a range of cognitive domains in healthy older aged adults. A cohort of 219 participants between the ages of 43 and 84 years (141 female) were recruited. Subjects provided a fasting blood sample for S100B measurement (Mean = 0.24 ng/mL, SD = 0.14) and completed a battery of neuropsychological tests. S100B concentrations (both with and without the covariates of age and sex) were positively associated with the following measures of cognitive performance: digit-symbol coding, Stroop test, and measures of verbal ability. The results from this study show that serum S100B is positively associated with better cognitive performance in healthy older adults

    Quantum quench spectroscopy of a Luttinger liquid: Ultrarelativistic density wave dynamics due to fractionalization in an XXZ chain

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    We compute the dynamics of localized excitations produced by a quantum quench in the spin 1/2 XXZ chain. Using numerics combining the density matrix renormalization group and exact time evolution, as well as analytical arguments, we show that fractionalization due to interactions in the pre-quench state gives rise to "ultrarelativistic" density waves that travel at the maximum band velocity. The system is initially prepared in the ground state of the chain within the gapless XY phase, which admits a Luttinger liquid (LL) description at low energies and long wavelengths. The Hamiltonian is then suddenly quenched to a band insulator, after which the chain evolves unitarily. Through the gapped dispersion of the insulator spectrum, the post-quench dynamics serve as a "velocity microscope," revealing initial state particle correlations via space time density propagation. We show that the ultrarelativistic wave production is tied to the particular way in which fractionalization evades Pauli-blocking in the zero-temperature initial LL state.Comment: 32 pages, 27 figures; v2: references update

    The pH dependency of the boron isotopic composition of diatom opal (Thalassiosira weissflogii)

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    The high-latitude oceans are key areas of carbon and heat exchange between the atmosphere and the ocean. As such, they are a focus of both modern oceanographic and palaeoclimate research. However, most palaeoclimate proxies that could provide a long-term perspective are based on calcareous organisms, such as foraminifera, that are scarce or entirely absent in deep-sea sediments south of 50∘ S in the Southern Ocean and north of 40∘ N in the North Pacific. As a result, proxies need to be developed for the opal-based organisms (e.g. diatoms) found at these high latitudes, which dominate the biogenic sediments recovered from these regions. Here we present a method for the analysis of the boron (B) content and isotopic composition (δ11B) of diatom opal. We apply it for the first time to evaluate the relationship between seawater pH, δ11B and B concentration ([B]) in the frustules of the diatom Thalassiosira weissflogii, cultured across a range of carbon dioxide partial pressure (pCO2) and pH values. In agreement with existing data, we find that the [B] of the cultured diatom frustules increases with increasing pH (Mejía et al., 2013). δ11B shows a relatively well defined negative trend with increasing pH, completely distinct from any other biomineral previously measured. This relationship not only has implications for the magnitude of the isotopic fractionation that occurs during boron incorporation into opal, but also allows us to explore the potential of the boron-based proxies for palaeo-pH and palaeo-CO2 reconstruction in high-latitude marine sediments that have, up until now, eluded study due to the lack of suitable carbonate material

    Mechanized Metatheory for the Masses: The \u3cb\u3ePOPLMARK\u3c/b\u3e Challenge

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    How close are we to a world where every paper on programming languages is accompanied by an electronic appendix with machinechecked proofs? We propose an initial set of benchmarks for measuring progress in this area. Based on the metatheory of System F, a typed lambda-calculus with second-order polymorphism, subtyping, and records, these benchmarks embody many aspects of programming languages that are challenging to formalize: variable binding at both the term and type levels, syntactic forms with variable numbers of components (including binders), and proofs demanding complex induction principles. We hope that these benchmarks will help clarify the current state of the art, provide a basis for comparing competing technologies, and motivate further research
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