32 research outputs found

    Understanding smart contracts as a new option in transaction cost economics

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    Among different concepts associated with the term blockchain, smart contracts have been a prominent one, especially popularized by the Ethereum platform. In this study, we unpack this concept within the framework of Transaction Cost Economics (TCE). This institutional economics theory emphasizes the role of distinctive (private and public) contract law regimes in shaping firm boundaries. We propose that widespread adoption of the smart contract concept creates a new option in public contracting, which may give rise to a smart-contract-augmented contract law regime. We discuss tradeoffs involved in the attractiveness of the smart contract concept for firms and the resulting potential for change in firm boundaries. Based on our new conceptualization, we discuss potential roles the three branches of government – judicial, executive, and legislative – in enabling and using this new contract law regime. We conclude the paper by pointing out limitations of the TCE perspective and suggesting future research directions

    Understanding Smart Contracts as a New Option in Transaction Cost Economics

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    Among different concepts associated with the term blockchain, smart contracts have been a prominent one, especially popularized by the Ethereum platform. In this study, we unpack this concept within the framework of Transaction Cost Economics (TCE). This institutional economics theory emphasizes the role of distinctive (private and public) contract law regimes in shaping firm boundaries. We propose that widespread adoption of the smart contract concept creates a new option in public contracting, which may give rise to a smart-contract-augmented contract law regime. We discuss tradeoffs involved in the attractiveness of the smart contract concept for firms and the resulting potential for change in firm boundaries. Based on our new conceptualization, we discuss potential roles the three branches of government – judicial, executive, and legislative – in enabling and using this new contract law regime. We conclude the paper by pointing out limitations of the TCE perspective and suggesting future research directions

    Cross-Protective Shigella Whole-Cell Vaccine With a Truncated O-Polysaccharide Chain

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    Shigella is a highly prevalent bacterium causing acute diarrhea and dysentery in developing countries. Shigella infections are treated with antibiotics but Shigellae are increasingly resistant to these drugs. Vaccination can be a countermeasure against emerging antibiotic-resistant shigellosis. Because of the structural variability in Shigellae O-antigen polysaccharides (Oag), cross-protective Shigella vaccines cannot be derived from single serotype-specific Oag. We created an attenuated Shigella flexneri 2a strain with one rather than multiple Oag units by disrupting the Oag polymerase gene (Δwzy), which broadened protective immunogenicity by exposing conserved surface proteins. Inactivated Δwzy mutant cells combined with Escherichia coli double mutant LT(R192G/L211A) as adjuvant, induced potent antibody responses to outer membrane protein PSSP-1, and type III secretion system proteins IpaB and IpaC. Intranasal immunization with the vaccine preparation elicited cross-protective immunity against S. flexneri 2a, S. flexneri 3a, S. flexneri 6, and Shigella sonnei in a mouse pneumonia model. Thus, S. flexneri 2a Δwzy represents a promising candidate strain for a universal Shigella vaccine

    CCAT2, a novel noncoding RNA mapping to 8q24, underlies metastatic progression and chromosomal instability in colon cancer

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    The functional roles of SNPs within the 8q24 gene desert in the cancer phenotype are not yet well understood. Here, we report that CCAT2, a novel long noncoding RNA transcript (lncRNA) encompassing the rs6983267 SNP, is highly overexpressed in microsatellite-stable colorectal cancer and promotes tumor growth, metastasis, and chromosomal instability. We demonstrate that MYC, miR-17-5p, and miR-20a are up-regulated by CCAT2 through TCF7L2-mediated transcriptional regulation. We further identify the physical interaction between CCAT2 and TCF7L2 resulting in an enhancement of WNT signaling activity. We show that CCAT2 is itself a WNT downstream target, which suggests the existence of a feedback loop. Finally, we demonstrate that the SNP status affects CCAT2 expression and the risk allele G produces more CCAT2 transcript. Our results support a new mechanism of MYC and WNT regulation by the novel lncRNA CCAT2 in colorectal cancer pathogenesis, and provide an alternative explanation of the SNP-conferred cancer risk

    Modeling narrative structure and dynamics with networks, sentiment analysis, and topic modeling.

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    Human communication is invariably executed in the form of a narrative, an account of connected events comprising characters, actions, and settings. A coherent and well-structured narrative is therefore essential for effective communication, confusion caused by a haphazard attempt at storytelling being a common experience. This also suggests that a scientific understanding of how a narrative is formed and delivered is key to understanding human communication and dialog. Here we show that the definition of a narrative lends itself naturally to network-based modeling and analysis, and they can be further enriched by incorporating various text analysis methods from computational linguistics. We model the temporally unfolding nature of narrative as a dynamical growing network of nodes and edges representing characters and interactions, which allows us to characterize the story progression using the network growth pattern. We also introduce the concept of an interaction map between characters based on associated sentiments and topics identified from the text that characterize their relationships explicitly. We demonstrate the methods via application to Victor Hugo's Les Misérables. Going beyond simple, aggregate occurrence-based methods for narrative representation and analysis, our proposed methods show promise in uncovering its essential nature of a highly complex, dynamic system that reflects the rich structure of human interaction and communication

    Charity or Investment: Linguistic Features of Identifiable Victim Effect in Microlending

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    With the widespread adoption of crowdfunding, new questions arise concerning how individuals make funding decisions online where the role of texts as well as pictures and videos become particularly important. Our study used the text from Kiva which enables prosocial lending to small business and community groups located in emerging markets. Given that funders do exhibit prosocial motivation, we draw on the identifiable victim effect theory which postulates identifiability of a victim leads to greater charitable giving. We then develop nuanced linguistic features to operationalize the identifiable victim effect and test if operationalization has an impact on funding. Our work found that some of the hypotheses related to vividness and certainty are supported. This study has a potential to make a significant contribution to the growing body of prosocial lending studies by enriching the literature using identifiable victim effect theory and operationalizing nuanced linguistic features

    What does contact tracing really mean?: How governments and citizens contest the meaning of contact tracing to achieve societal resilience

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    During the COVID-19 pandemic, contact tracing has become a major government effort to slow down the spread of the infectious disease. As societies started implementing contact tracing technologies, they encountered tensions between conflicting values involved in protecting human rights (e.g., freedom of movement versus health security). These tensions sparked a contestation process over the meaning of contact tracing technologies. Our study investigates how two societies, South Korea and Singapore, grappled with the meaning of contact tracing technologies during the COVID-19 pandemic. We frame our inductive findings by drawing on category research to build a theoretical model of the contestation processes around new technologies. We contribute to category research by showing how a societal value system involving conflicting values is invoked in contesting the meaning of new technologies. We unpack how category contestation is shaped by and shapes technology design and use, which, in turn, is shaped by societal power structures

    Anticancer Activity of Pyrimethamine via Ubiquitin Mediated Degradation of AIMP2-DX2

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    While aminoacyl-tRNA synthetase-interacting multifunctional protein 2 (AIMP2) is a tumor suppressor, its exon 2-depleted splice variant (AIMP2-DX2 or shortly DX2) is highly expressed in human lung cancer, and the ratio of DX2 to AIMP2 increases according to the progression of lung cancer. In this study, pyrimethamine inhibited the level of DX2 (IC50 = 0.73 µM) in A549 cells expressing nanoluciferase-tagged DX2. In a panel of 5 lung cancer cell lines with various DX2 levels, pyrimethamine most potently suppressed the growth of H460 cells, which express high levels of DX2 (GI50 = 0.01 µM). An immunoblot assay in H460 cells showed that pyrimethamine decreased the DX2 level dose-dependently but did not affect the AIMP2 level. Further experiments confirmed that pyrimethamine resulted in ubiquitination-mediated DX2 degradation. In an in vivo mouse xenograft assay using H460 cells, intraperitoneal administration of pyrimethamine significantly reduced the tumor size and weight, comparable with the effects of taxol, without affecting body weight. Analysis of tumor tissue showed a considerably high concentration of pyrimethamine with a decreased levels of DX2. These results suggest that pyrimethamine, currently used as anti-parasite drug, could be repurposed to treat lung cancer patients expressing high level of DX2

    Multifunctional PDO Thread Coated with Mg(OH)<sub>2</sub>/ZnO Nanoparticles and Asiaticoside for Improved Facial Lifting

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    As interest in skin aesthetics increases, treatments to suppress aging are increasing. Among them, a facelift is the most effective procedure for improving wrinkles. However, side effects including inflammatory reactions occur due to the limitations of the PDO thread itself used during the procedure. In this paper, to improve the function of PDO thread, inorganic particles such as magnesium hydroxide (MH) and zinc oxide (ZO) and a biologically active agent, asiaticoside, were coated on the surface of PDO thread using ultrasonic coating technology. The coated thread exhibited excellent biocompatibility, promoted collagen synthesis, reduced inflammation, and stimulated angiogenesis in vitro and in vivo. The multifunctional PDO thread has shown promising potential for skin regeneration without inducing fibrosis. Such a practical coating system and the developed multifunctional PDO thread suggest new possibilities for developing safer and more effective materials in cosmetic and regenerative medicine to prevent aging and improve skin aesthetics

    Self-assembling β-glucan nanomedicine for the delivery of siRNA

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    We aimed to design and manufacture a transporter capable of delivering small interfering RNAs (siRNAs) into the skin without causing any damage. β-glucans are unique chiral polysaccharides with well-defined immunological properties and supramolecular wrapping ability. However, the chiral properties of these polymers have hardly been applied in drug delivery systems. In this study, β-glucan nanoparticles were designed and manufactured to deliver genetic material to the target cells. The β-glucan molecules were self-assembled with an siRNA into nanoparticles of 300–400 nm in diameter via a conformational transition process, in order to construct a gene delivery system. The assembled gene nanocarriers were associated with high gene-loading ability. The expression and efficiency of siRNA were verified after its delivery via β-glucan. Our results provide evidence that β-glucan nanoparticles can be effectively used to deliver siRNA into the cells.Published versio
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