4,812 research outputs found

    Interspecific differences in the larval performance of Pieris butterflies (Lepidoptera: Pieridae) are associated with differences in the glucosinolate profiles of host plants

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    The tremendous diversity of plants and herbivores has arisen from a coevolutionary relationship characterized by plant defense and herbivore counter adaptation. Pierid butterfly species feed on Brassicales plants that produce glucosinolates as a chemical deterrent against herbivory. In turn, the larvae of pierids have nitrile specifier proteins (NSPs) that are expressed in their gut and disarm glucosinolates. Pierid butterflies are known to have diversified in response to glucosinolate diversification in Brassicales. Therefore, each pierid species is expected to have a spectrum of host plants characterized by specific glucosinolate profiles. In this study, we tested whether the larval performance of different Pieris species, a genus in Pieridae (Lepidoptera: Pieridae), was associated with plant defense traits of putative host plants. We conducted feeding assays using larvae of three Pieris species and 10 species of the Brassicaceae family possessing different leaf physical traits and glucosinolate profile measurements. The larvae of Pieris rapae responded differently in the feeding assays compared with the other two Pieris species. This difference was associated with differences in glucosinolate profiles but not with variations in physical traits of the host plants. This result suggests that individual Pieris species are adapted to a subset of glucosinolate profiles within the Brassicaceae. Our results support the idea that the host ranges of Pieris species depend on larval responses to glucosinolate diversification in the host species, supporting the hypothesis of coevolution between butterflies and host plants mediated by the chemical arms race

    Room temperature ferromagnetic behavior in the hollandite-type titanium oxide

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    A hollandite-type K(x)Ti(8)O(16) polycrystalline sample has been prepared and studied by magnetization, resistivity and x-ray photoelectron spectroscopy (XPS). Room temperature ferromagnetic behavior is observed in the magnetic hysteresis measurement. The sample shows a semiconductive temperature dependence in the resistivity measurement. Analysis of the Ti 2p(3/2) core-level XPS spectrum indicates that the titanium ions have a mixed valence of Ti(4+) and Ti(3+). In addition, the valence band spectrum reveals that the 3d electrons tend to localize on Ti(3+) ions in the hollandite-type TiO(2) lattice. Also, analysis of the valence band spectrum shows that the prepared sample is a wide-gap oxide with a band gap of 3.6 eV. These results indicate that the present hollandite-type K(x)Ti(8)O(16) sample can be classified as a TiO(2)-based wide-gap semiconductor with Curie temperature above room temperature. Room temperature ferromagnetism (RTFM) decreases in the sample prepared under a strong reducing gas atmosphere, accompanied with the decrease in the resistivity. The results imply that the localized 3d electrons are responsible for the RTFM of the K(x)Ti(8)O(16) sample

    Hybrid ECAL: Optimization and Related Developments

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    Hybrid ECAL is a cost-conscious option of electromagnetic calorimeter (ECAL) for particle flow calorimetry to be used in a detector of International Linear Collider (ILC). It is a combination of silicon-tungsten ECAL, which realizes high granularity and robust measurement of electromagnetic shower, and scintillator-tungsten ECAL, which gives affordable cost with similar performance to silicon. Optimization and a data acquisition trial in a test bench for the hybrid ECAL are described in this article.Comment: 7 pages, 4 figures, Talk presented at the International Workshop on Future Linear Colliders (LCWS14), Belgrade, Serbia, 6-10 October 201

    A Semantic Framework for the Security Analysis of Ethereum smart contracts

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    Smart contracts are programs running on cryptocurrency (e.g., Ethereum) blockchains, whose popularity stem from the possibility to perform financial transactions, such as payments and auctions, in a distributed environment without need for any trusted third party. Given their financial nature, bugs or vulnerabilities in these programs may lead to catastrophic consequences, as witnessed by recent attacks. Unfortunately, programming smart contracts is a delicate task that requires strong expertise: Ethereum smart contracts are written in Solidity, a dedicated language resembling JavaScript, and shipped over the blockchain in the EVM bytecode format. In order to rigorously verify the security of smart contracts, it is of paramount importance to formalize their semantics as well as the security properties of interest, in particular at the level of the bytecode being executed. In this paper, we present the first complete small-step semantics of EVM bytecode, which we formalize in the F* proof assistant, obtaining executable code that we successfully validate against the official Ethereum test suite. Furthermore, we formally define for the first time a number of central security properties for smart contracts, such as call integrity, atomicity, and independence from miner controlled parameters. This formalization relies on a combination of hyper- and safety properties. Along this work, we identified various mistakes and imprecisions in existing semantics and verification tools for Ethereum smart contracts, thereby demonstrating once more the importance of rigorous semantic foundations for the design of security verification techniques.Comment: The EAPLS Best Paper Award at ETAP

    Music and Man in Art : The Future of Media and Technology

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    Music can provide psychological benefit, and music therapy has been accepted for many people across the world. Iso-principle has been known as an important concept in music therapy. Art is roughly divided into two categories, which are visual arts and reproducing arts. An attempt to overlap these categories would be a method of recording and playing back music. Historically, human could come to experience polyphonic music like the instrument of Carillon, to listen to reproducing music by music score and phonograph, and to be enjoy music anytime by use of media and technology. Recent music environment includes the voice synthesis technology "VOCALOID", a video distribution site on the internet. In the future, music will make people happier if new technologies are widely recognized and personalized use is widespread

    Enrichment of Strontium in Dwarf Galaxies

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    Light trans-iron elements such as Sr serve as the key to understanding the astrophysical sites of heavy elements. Spectroscopic studies of metal-poor stars have revealed large star-to-star scatters in the ratios of [Sr/Ba], which indicates that there are multiple sites for the production of Sr. Here we present the enrichment history of Sr by a series of the NN-body/smoothed particle hydrodynamics simulations of a dwarf galaxy with a stellar mass of 3 ×\times 106^{6} M⊙M_{\odot}. We show that binary neutron star mergers (NSMs) and asymptotic giant branch (AGB) stars contribute to the enrichment of Sr in the metallicity ranges [Fe/H] ≳\gtrsim −-3 and [Fe/H] ≳\gtrsim −-1, respectively. It appears insufficient, however, to explain the overall observational trends of Sr by considering only these sites. We find that the models including electron-capture supernovae (ECSNe) and rotating massive stars (RMSs), in addition to NSMs and AGBs, reasonably reproduce the enrichment histories of Sr in dwarf galaxies. The contributions of both ECSNe and NSMs make scatters of ≈\approx 0.2 dex in [Sr/Fe], [Sr/Ba], and [Sr/Zn] as can be seen for observed stars in the metallicity range [Fe/H] << −2-2. We also find that the mass range of ECSN progenitors should be substantially smaller than 1 M⊙1\, M_\odot (e.g., 0.1-0.2 M⊙0.2\, M_\odot) to avoid over-prediction of [Sr/Ba] and [Sr/Zn] ratios. Our results demonstrate that NSMs, AGBs, ECSNe, and RMSs all play roles in the enrichment histories of Local Group dwarf galaxies, although more observational data are required to disentangle the relative contributions of these sources

    Designing Secure Ethereum Smart Contracts: A Finite State Machine Based Approach

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    The adoption of blockchain-based distributed computation platforms is growing fast. Some of these platforms, such as Ethereum, provide support for implementing smart contracts, which are envisioned to have novel applications in a broad range of areas, including finance and Internet-of-Things. However, a significant number of smart contracts deployed in practice suffer from security vulnerabilities, which enable malicious users to steal assets from a contract or to cause damage. Vulnerabilities present a serious issue since contracts may handle financial assets of considerable value, and contract bugs are non-fixable by design. To help developers create more secure smart contracts, we introduce FSolidM, a framework rooted in rigorous semantics for designing con- tracts as Finite State Machines (FSM). We present a tool for creating FSM on an easy-to-use graphical interface and for automatically generating Ethereum contracts. Further, we introduce a set of design patterns, which we implement as plugins that developers can easily add to their contracts to enhance security and functionality

    Analysis of Reaction Forces and Posture of a Bunch of Crop Stalks During Reel Operations of a Combine Harvester

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    Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a Technical Paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 4 (2002): Y. Hirai, E. Inoue, K. Mori, and K. Hashiguchi. Analysis of Reaction Forces and Posture of a Bunch of Crop Stalks During Reel Operations of a Combine Harvester. Vol. IV. October 2002
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