Moulin (1986) characterizes the pivotal mechanisms under the assumption of the full domain of quasi-linear preferences. In this paper, we provide properties of restricted domains that are necessary ...and sufficient for Moulin’s (1986) strategy-proof characterizations to hold. We also provide simple economic conditions that imply these properties.
•This paper studies Moulin’s (1986) characterizations of the pivotal mechanisms.•We provide properties of domains necessary and sufficient for his characterizations.•We also provide simple economic conditions that imply these properties.
Moulin (J Public Econ 31:53–78, 1986; Theorem 4) characterizes the pivotal mechanisms without imposing
strategy-proofness
under the assumption of the full domain. In this paper, we provide a domain ...property that is necessary and sufficient for Moulin’s characterization without strategy-proofness to hold. We also provide examples of domains that do (not) satisfy our domain property.
Due to the rapid penetration of the Internet of Things (IoT) into human life, illegal access to IoT resources (e.g., data and actuators) has greatly threatened our safety. Access control, which ...specifies who (i.e., subjects) can access what resources (i.e., objects) under what conditions, has been recognized as an effective solution to address this issue. To cope with the distributed and trust-less nature of IoT systems, we propose a decentralized and trustworthy Capability-Based Access Control (CapBAC) scheme by using the Ethereum smart contract technology. In this scheme, a smart contract is created for each object to store and manage the capability tokens (i.e., data structures recording granted access rights) assigned to the related subjects, and also to verify the ownership and validity of the tokens for access control. Different from previous schemes which manage the tokens in units of subjects, i.e., one token per subject, our scheme manages the tokens in units of access rights or actions, i.e., one token per action. Such novel management achieves more fine-grained and flexible capability delegation and also ensures the consistency between the delegation information and the information stored in the tokens. We implemented the proposed CapBAC scheme in a locally constructed Ethereum blockchain network to demonstrate its feasibility. In addition, we measured the monetary cost of our scheme in terms of gas consumption to compare our scheme with the existing Blockchain-Enabled Decentralized Capability-Based Access Control (BlendCAC) scheme proposed by other researchers. The experimental results show that the proposed scheme outperforms the BlendCAC scheme in terms of the flexibility, granularity, and consistency of capability delegation at almost the same monetary cost.
Abstract
Knapsack problem (KP) is a representative combinatorial optimization problem that aims to maximize the total profit by selecting a subset of items under given constraints on the total ...weights. In this study, we analyze a generalized version of KP, which is termed the generalized multidimensional knapsack problem (GMDKP). As opposed to the basic KP, GMDKP allows multiple choices per item type under multiple weight constraints. Although several efficient algorithms are known and the properties of their solutions have been examined to a significant extent for basic KPs, there is a paucity of known algorithms and studies on the solution properties of GMDKP. To gain insight into the problem, we assess the typical achievable limit of the total profit for a random ensemble of GMDKP using the replica method. Our findings are summarized as follows: (1) when the profits of item types are normally distributed, the total profit grows in the leading order with respect to the number of item types as the maximum number of choices per item type
x
max
increases while it depends on
x
max
only in a sub-leading order if the profits are constant among the item types. (2) A greedy-type heuristic can find a nearly optimal solution whose total profit is lower than the optimal value only by a sub-leading order with a low computational cost. (3) The sub-leading difference from the optimal total profit can be improved by a heuristic algorithm based on the cavity method. Extensive numerical experiments support these findings.
Regarding crystalline film growth on large lattice-mismatched substrates, there are two primary modes by which thin films grow on a crystal surface or interface. They are Volmer-Weber (VW: island ...formation) mode and Stranski-Krastanov (SK: layer-plus-island) mode. Since both growth modes end up in the formation of three-dimensional (3D) islands, fabrication of single crystalline films on lattice-mismatched substrates has been challenging. Here, we demonstrate another growth mode, where a buffer layer consisting of 3D islands initially forms and a relaxed two-dimensional (2D) layer subsequently grows on the buffer layer. This 3D-2D mode transition has been realized using impurities. We observed the 3D-2D mode transition for the case of ZnO film growth on 18%-lattice-mismatched sapphire substrates. First, nano-sized 3D islands grow with the help of nitrogen impurities. Then, the islands coalesce to form a 2D layer after cessation of the nitrogen supply, whereupon an increase in the surface energy may provide a driving force for the coalescence. Finally, the films grow in 2D mode, forming atomically flat terraces. We believe that our findings will offer new opportunities for high-quality film growth of a wide variety of materials that have no lattice-matched substrates.
We propose a model of incomplete twofold multiprior preferences, in which an act f is ranked above an act g only when f provides higher utility in a worst-case scenario than what g provides in a ...best-case scenario. The model explains failures of contingent reasoning, captured through a weakening of the state-by-state monotonicity (or dominance) axiom. Our model gives rise to rich comparative statics results, as well as extension exercises, and connections to choice theory. We present an application to second-price auctions.
Mg2Mo3O8 was synthesized by a solid-phase method in a high vacuum atmosphere. According to the combination of ICP-AES technique and Rietveld analysis for synchrotron X-ray and neutron diffraction ...patterns, the structure and composition of the synthesized material was identified as single phase of the layered Mg2Mo3O8 of P63mc space-group. Charge and discharge cycle tests showed that Mg2Mo3O8 with carbon composite exhibited 18 and 89 mAh g−1 of initial charge and discharge capacities at 90 °C. Reversible charge/discharge behavior was confirmed up to 5 cycles. Electrochemical demagnesiation using Li anode showed deintercalation of 0.45 Mg2+ pfu. The valence of the Mo in synthesized material was determined by XAFS, whose spectrum at the Mo K-edge confirmed the reductive synthesis of Mg2Mo3O8 because of not hexavalent but reduced tetravalent Mo. Since the Mo K-edge XANES spectrum after first charge was oxidized from tetravalent, it was revealed that the Mg2Mo3O8 could electrochemically demagnesiate in the present cell-condition using Mg(G4)TFSA2/PYR13TFSA electrolyte. The PDF data from synchrotron X-ray total scattering was used to analyze the local structure. The local structure leads to the Mg hopping route in Mg2Mo3O8, where tetrahedrally coordinated Mg hops via octahedral site.
•Single phase Mg2Mo3O8 was firstly synthesized by reductive calcination.•Stable electrolyte and carbon composite induced electrochemically active•PDF analysis supported a Mg diffusion path using from tetrahedral to octahedral route.
Von Willebrand Factor and ABO Blood Group Matsui, Taei; Nakamura, Yuta
Trends in Glycoscience and Glycotechnology,
2020/09/25, Letnik:
32, Številka:
189
Journal Article
Recenzirano
Odprti dostop
Although ABO blood group antigens are widely distributed on the surface of red blood cells and epithelial cells, and in secreted body fluids, the biological function of these antigens is not clearly ...elucidated. Von Willebrand factor (VWF), the molecular glue between platelets and injured vessels essential for the formation of thrombotic plugs, may shed a light on their function. VWF is a unique plasma protein carrying ABO blood group antigens. Blood group influences the plasma concentration of VWF, and its level in those of blood group O is about 25% less than in non-O groups. Blood group O individuals are less sensitive to thrombotic disorders such as cardiovascular disease than non-O individuals. However, among those of blood group O, there is a significant association with high mortality in severe trauma patients. The sensitivity of VWF toward ADAMTS13, a physiological VWF-cleaving proteinase in plasma, is higher in those of blood group O, suggesting the protective role of blood group sugar chains. Although the capping sialic acid residue of plasma glycoprotein has been considered as a negatively charged barrier to hydrolyzing enzymes such as proteinase, and the penultimate galactose residue, once exposed, functions as a clearance marker for asialo-glycoprotein receptor, ABO blood group sugar chains on VWF may function as a neutral sugar chain barrier protecting the glycoprotein.
The dorsal axial muscles, or epaxial muscles, are a fundamental structure covering the spinal cord and vertebrae, as well as mobilizing the vertebrate trunk. To date, mechanisms underlying the ...morphogenetic process shaping the epaxial myotome are largely unknown. To address this, we used the medaka
-enhancer mutant
(
), which exhibits ventralized dorsal trunk structures resulting in impaired epaxial myotome morphology and incomplete coverage over the neural tube. In wild type, dorsal dermomyotome (DM) cells reduce their proliferative activity after somitogenesis. Subsequently, a subset of DM cells, which does not differentiate into the myotome population, begins to form unique large protrusions extending dorsally to guide the epaxial myotome dorsally. In
, by contrast, DM cells maintain the high proliferative activity and mainly form small protrusions. By combining RNA- and ChIP-sequencing analyses, we revealed direct targets of Zic1, which are specifically expressed in dorsal somites and involved in various aspects of development, such as cell migration, extracellular matrix organization, and cell-cell communication. Among these, we identified
as a crucial factor regulating both cell proliferation and protrusive activity of DM cells. We propose that dorsal extension of the epaxial myotome is guided by a non-myogenic subpopulation of DM cells and that
empowers the DM cells to drive the coverage of the neural tube by the epaxial myotome.
Clinical use of human pluripotent stem cells (hPSCs) is hampered by the technical limitations of their expansion. Here, we developed a chemically synthetic culture substrate for human pluripotent ...stem cell attachment and maintenance. The substrate comprises a hydrophobic polyvinyl butyral-based polymer (PVB) and a short peptide that enables easy and uniform coating of various types of cell culture ware. The coated ware exhibited thermotolerance, underwater stability and could be stored at room temperature. The substrate supported hPSC expansion in combination with most commercial culture media with an efficiency similar to that of commercial substrates. It supported not only the long-term expansion of examined iPS and ES cell lines with normal karyotypes during their undifferentiated state but also directed differentiation of three germ layers. This substrate resolves major concerns associated with currently used recombinant protein substrates and could be applied in large-scale automated manufacturing; it is suitable for affordable and stable production of clinical-grade hPSCs and hPSC-derived products.
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