212 research outputs found

    VENTRILOCATION

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    Mobile phones can locate users' location through multiple methods. Even through privacy-conscious users can disable location services such as GPS and Wi-Fi access points, they are not able to prevent the leakage of location information through cellular based positioning. In this paper, Ventrilocation is presented. It is an RF dongle that provides location-spoofing service for LTE-enabled devices while preserving full voice and data functionality. Specifically, it affects the raw data and results of a standard multilateration positioning method in LTE networks, known as observed time difference of arrival (OTDOA). OTDOA measures the difference between the arrival time of signals from different base stations to obtain the relative location of the user equipment (UE) to the base stations. Ventrilocation changes the time difference of arrival (TDOA) by introducing different delays to signals from different base stations. It consists of directional antennas to isolate signals and a circuit to delay the downlink signals. The surface acoustic wave (SAW) technology allows a chip-size delay line component to generate a significant amount of delay in the LTE frequency bands. The first prototype of Ventrilocation uses SAW delay lines with fixed delay, but with programmable SAW delay lines, the spoofed location can be designed to follow certain routes to achieve more reliable spoofing results.Ope

    Effects of 1-methylcyclopropene on superficial scald and related metabolism in ‘Wujiuxiang’ pears during cold storage

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    ‘Wujiuxiang’ (Pyrus bretschneideri R. × Pyrus communis L.) pears often suffer from superficial scald after long-term cold storage. In this study, harvested ‘Wujiuxiang’ pear fruits were fumigated with 1-MCP at concentrations of 0.5 μL/L and 1.0 μL/L and subsequently stored at low temperature (0 °C). The superficial scald index; flesh firmness; total soluble solids (TSS) content; respiration and ethylene production rates; relative membrane permeability; concentrations of α-farnesene, conjugated trienols (CTols), and hydrogen peroxide (H2O2); and activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and lipoxygenase (LOX) of the peel were investigated. The results showed that compared with control, 1-MCP reduced the index of superficial scald; maintained a higher firmness and a lower TSS content; inhibited the accumulation of H2O2, α-farnesene and conjugated trienols and the increase in cell membrane permeability; and maintained a higher activity of APX, SOD and CAT and a lower activity of LOX. These findings indicate that 1-MCP regulates the activities of H2O2-scavenging enzymes to inhibit the accumulation of H2O2 and thereby reduces cell membrane damage and inhibits the accumulation of conjugated trienols. Thus, 1-MCP could decrease the incidence of superficial scald in ‘Wujiuxiang’ pears

    The involvement of phenolic metabolism in superficial scald development in ‘Wujiuxiang’ pear

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    Superficial scald often occurs after a long term of cold storage in apples and pears. In this study, the superficial scald index, the contents of major phenolic compounds, polyphenol oxidase (PPO) activity and its related genes expression in peel was investigated during cold storage period and at shelf life in ‘Wujiuxiang’ pear (Pyrus communis L. cv. Wujiuxiang) with or without 1-MCP treatment. It showed that arbutin, chlorogenic acid, catechin and epi-catechin were the main phenolic compounds in the peel, and 1-MCP treatment significantly inhibited scald development while altering the composition of phenolic compounds, inhibited PPO activity and the expression of phenylalanine ammonia ligase (PAL1, PAL2), cinnamate 4-hydroxylase (C4H1, C4H2) and PPO (PPO1, PPO5) and up-regulated the expression of hydroxycinnamoyl-CoA shikimate/quinate hydroycinnamoyltransferase (HCT1), p-coumarate-3-hydro-xylase (C3H) and PPO (PPO4 and PPO6) in the peel. These results suggested that the phenolic metabolism is closely related to the scald development, and several genes related to phenolic metabolism were involved in scald development

    The consumption-based black carbon emissions of China's megacities

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    A growing body of literature discusses the CO2 emissions of cities. Still, little is known about black carbon (BC), a short-lived warming agent. Identifying the drivers of urban BC emissions is crucial for targeting cleanup efforts. A consumption-based approach enables all emissions to be allocated along the production chain to the product and place of final consumption, whereas a production approach attributes emissions to the place where goods and services are produced. In this study, we calculate the production-based and consumption-based emissions in 2012 in four Chinese megacities: Beijing, Shanghai, Tianjin and Chongqing. The results show that capital formation is the largest contributor, accounting for 37%–69% of consumption-based emissions. Approximately 44% of BC emissions related to goods consumed in Chongqing and more than 60% for Beijing, Shanghai and Tianjin occur outside of the city boundary. The large gap between consumption and production-based emissions can be attributed to the great difference in embodied emission intensities. Therefore, collaborative efforts to reduce emission intensity can be effective in mitigating climate change for megacities as either producers or consumers

    Different response to 1-methylcyclopropene in two cultivars of Chinese pear fruit with contrasting softening characteristics

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    In this study, the change in softening and its related genes expression under influence of 500 nl L-1 1-methylcyclopropene (1-MCP) was assessed in the two Chinese pear fruit, ‘Jingbaili’ (Pyrus ussuriensis Maxim) and ‘Yali’ (Pyrus bretschneideri Rehd), which exhibit different softening characteristics. ‘Jingbaili’ pear fruit softened rapidly after harvest, and was strongly inhibited by 1-MCP. In contrast, there was no obvious change of firmness compared to the control after 1-MCP treatment in ‘Yali’ pear fruit. The respiration and ethylene production rates were reduced by 1-MCP at early storage in both two cultivars. ‘Jingbaili’ pear fruit exhibited dramatically increased expression levels of the softening-related genes, i.e., polygalacturonase1 (PG1), polygalacturonase2 (PG2), β-Galactosidase4 (GAL4), α-arabinofuranosidase1 (ARF1) and α-arabinofuranosidase2 (ARF2), and these genes’ expression levels were significantly decreased by 1-MCP treatment. In contrast, ‘Yali’ pear fruit showed lower expression levels of the above-mentioned genes, as well as a relatively smaller inhibition effect by 1-MCP treatment before day 27. These results suggest that ‘Jingbaili’ pear fruit are more sensitive to 1-MCP/ethylene than ‘Yali’ pear fruit during ripening

    The influence of 1-MCP on the fruit quality and flesh browning of ‘Red Fuji’ apple after long-term cold storage

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    This study assessed the influence of 1-MCP treatment on the fruit quality and flesh browning of ‘Red Fuji’ apple at shelf life after long-term cold storage. The ‘Red Fuji’ fruit were stored at 0±0.5 °C for 270 days after treating with 1.0 μL L-1 1-methylcyclopropylene (1-MCP). Fruit quality, browning rate of stem-end flesh, chlorogenic acid content, polyphenol oxidase (PPO) activity were analyzed at shelf-life under 20±0.5 °C, the expression profile of ethylene receptors (MdERS1), phenylalnine ammonia lyase genes (MdPA L1, MdPA L2), quinate hydroxycinnamoyl/hydrxycinnamoyl CoA shi-kimate gene (MdHCT3), polyphenol oxidase genes (MdPPO1, MdPPO5)and lipoxygenase gene (MdLOX) were measured by real-time quantitative PCR. 1-MCP treatment improved the fruit storage quality, decreased stem-end flesh tissue browning, and fruit decay. In addition, the fruit respiration rate and ethylene production rate increased at shelf-life, but this increase could be inhibited by 1-MCP. The same rule was observed in the changes of chlorogenic acid content and PPO activity, the expression of MdERS1, MdPA L1, MdPPO1 and MdLOX were inhibited by 1-MCP as well in the stem-end flesh. Thus, 1-MCP treatment improves the fruit quality of ‘Red Fuji’ apple at shelf-life after long-term cold storage, and inhibits the browning of stem-end flesh by decreasing the chlorogenic acid content and PPO activity. MdPA L1, MdHCT3, MdPPO1 and MdLOX participate in the flesh browning progress

    Internet Of Rights(IOR) In Role Based Block Chain

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    A large amount of data has been accumulated. with the development of the Internet industry. Many problems have been exposed with data explosion: 1. The contradiction between data privacy and data collaborations; 2. The contradiction between data ownership and the right of data usage; 3. The legality of data collection and data usage; 4. The relationship between the governance of data and the governance of rules; 5. Traceability of evidence chain. In order to face such a complicated situation, many algorithms were proposed and developed. This article tries to build a model from the perspective of blockchain to make some breakthroughs.Internet Of Rights(IOR) model uses multi-chain technology to logically break down the consensus mechanism into layers, including storage consensus, permission consensus, role consensus, transaction consensus etc. thus to build a new infrastructure, which enables data sources with complex organizational structures and interactions to collaborate smoothly on the premise of protecting data privacy. With blockchain's nature of decentralization, openness, autonomy, immutability, and controllable anonymity, Internet Of Rights(IOR) model registers the ownership of data, enables applications to build ecosystem based on responsibilities and rights. It also provides cross-domain processing with privacy protection, as well as the separation of data governance and rule governance. With the processing capabilities of artificial intelligence and big data technology, as well as the ubiquitous data collection capabilities of the Internet of Things, Internet Of Rights(IOR) model may provide a new infrastructure concept for realizing swarm intelligence and building a new paradigm of the Internet, i.e. intelligent governance

    Globalization and pollution: tele-connecting local primary PM_(2.5) emissions to global consumption

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    Globalization pushes production and consumption to geographically diverse locations and generates a variety of sizeable opportunities and challenges. The distribution and associated effects of short-lived primary fine particulate matter (PM_(2.5)), a representative of local pollution, are significantly affected by the consumption through global supply chain. Tele-connection is used here to represent the link between production and consumption activity at large distances. In this study, we develop a global consumption-based primary PM_(2.5) emission inventory to track primary PM_(2.5) emissions embodied in the supply chain and evaluate the extent to which local PM2.5 emissions are triggered by international trade. We further adopt consumption-based accounting and identify the global original source that produced the emissions. We find that anthropogenic PM_(2.5) emissions from industrial sectors accounted for 24 Tg globally in 2007; approximately 30% (7.2 Tg) of these emissions were embodied in export of products principally from Brazil, South Africa, India and China (3.8 Tg) to developed countries. Large differences (up to 10 times) in the embodied emissions intensity between net importers and exporters greatly increased total global PM_(2.5) emissions. Tele-connecting production and consumption activity provides valuable insights with respect to mitigating long-range transboundary air pollution and prompts concerted efforts aiming at more environmentally conscious globalization
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