157 research outputs found

    Draft Genome Sequence of Streptomyces incarnatus NRRL8089, which Produces the Nucleoside Antibiotic Sinefungin

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    A draft genome sequence of Streptomyces incarnatus NRRL8089, which produces the nucleoside antibiotic sinefungin, is described here. The genome contains 8,897,465 bp in 76 contigs and 8,266 predicted genes. Interestingly, the genome encodes an open reading frame for selenocysteine-containing formate dehydrogenase-O and the selenoprotein biosynthetic gene cluster selABCD

    Experimental Investigation of Static Channel Bonding Performance in Competitive Environment -Impact of Different MAC Procedures in 802.11ac-

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    Channel bonding technology, which bundles multiple adjacent channels for frame transmission, is one of the promising way for improving throughput performance in IEEE802.11ac wireless LANs. However, channel bonding technology leads to co-channel interference with other access points (APs) within the bonded channels. In our previous study, we investigated transmission performance of several commercially-available 802.11ac APs. As a result, we clarified three communication procedures from difference in method of implementation of Request To Send (RTS) / Clear To Send (CTS) or not. Furthermore, we investigated the impact of RTS/CTS on transmission performance by conducting experiments where two APs using RTS/CTS are competing in a bonded channels. However, we have not investigated transmission performance in the case that APs with different transmission procedures compete with each other in a bonded channels. Therefore, in this study, we conducted experiments using real WLAN products. Then, we compared and evaluated the communication performance in the case that two APs with different transmission procedures compete in the same channel. As a result, we showed that the AP employing CTS-to-self doesn’t set duration time in CTS frames, thereby the communication performance of the AP using RTS/CTS in channel bonding degrades due to frequent collisions in conflict channel. On the other hand, since AP not using RTS/CTS dynamically adjusts the number of data frames for each transmission opportunity to avoid frame collisions, we confirmed that the communication performance can be relatively maintained even under the competitive environment. / IEEE802.11ac規格の通信高速化技術の一つに、隣接する複数のチャネルをまとめて利用するチャネルボンディング機能がある。しかし、通信帯域が拡大するため他の無線LAN機器と競合しやすくなってしまう。先行研究では、競合しない環境の単一のAPの通信性能を調査し、オプション機能のRequest To Send (RTS) / Clear To Send (CTS)の実装方法の違いから3パターンの通信手順があることを明らかにしたうえで、RTS/CTS利用の有無が競合時に性能に与える影響を調査した。しかし、CTS-to-Selfによる競合時の影響は未だ明らかになっていない。そこで本研究では、実機を用いた実験を行い、CTS-to-Selfによる競合時の通信性能を調査するとともに、3パターンの通信手順の競合時における各通信性能の比較および評価を行った。その結果、CTS-to-selfによる通信手順ではNAV期間が確保できていないためフレーム衝突が起こりやすく、RTS/CTSを利用しチャネルボンディングさせていたAPに悪影響を与えていた。それに対して、RTS/CTSを利用しないAPは、送信機会毎のデータフレーム数を調節しながら通信していたためフレーム衝突が起こりにくく、お互いの通信性能への影響が低減されていることがわかった。電子情報通信学会 スマート無線研究会(SR), 2018年10月30日-31日, Bangkok, Thailan

    Deployment Design of Wireless Sensor Network for Simple Multi-Point Surveillance of a Moving Target

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    In this paper, we focus on the problem of tracking a moving target in a wireless sensor network (WSN), in which the capability of each sensor is relatively limited, to construct large-scale WSNs at a reasonable cost. We first propose two simple multi-point surveillance schemes for a moving target in a WSN and demonstrate that one of the schemes can achieve high tracking probability with low power consumption. In addition, we examine the relationship between tracking probability and sensor density through simulations, and then derive an approximate expression representing the relationship. As the results, we present guidelines for sensor density, tracking probability, and the number of monitoring sensors that satisfy a variety of application demands

    Experimental Evaluation of Publish/Subscribe-based Spatio-Temporal Contents Management on Geo-Centric Information Platform

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    Cross-domain data fusion is becoming a key driver to growth of the numerous and diverse applications in IoT era. Nevertheless, IoT data obtained by individual devices are blindly transmitted to cloud servers. We here focus on that the IoT data which are suitable for cross-domain data fusion, tend to be generated in the proximity, and thus propose a Geo-Centric Information Platform (GCIP) for the management of Spatio-Temporal Contents (STCs) generated through the cross-domain data fusion. GCIP enables to keep STCs near the users (at an edge server). In this paper, we practically examine the fundamental functions of the GCIP from two aspects: (1) Geo-location aware data collection and (2) Publish/Subscribe-based STC production. Furthermore, we implement a proof-of-concepts (PoC) of GCIP and conduct experiments on a real IPv6 network built on our campus network. In this experiment, we showed that multiple types of IoT data generated in the proximity can be collected on the edge server and then a STC can be produced by exploiting the collected IoT data. Moreover, we demonstrated that the Publish/Subscribe model has a potential to be effective for STC management.22nd International Conference on Network-Based Information Systems(NBiS 2019), September 5-7, 2019, Oita, Japa

    Matching based content discovery method on Geo-Centric Information Platform

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    We have proposed a concept of new information platform, Geo-Centric information platform (GCIP), that enables IoT data fusion based on geolocation. GCIP produces new and dynamic contents by combining cross-domain data in each geographic area and provides them to users. In this environment, it is difficult to find appropriate contents requested by a user because the user cannot recognize what contents are created in each area beforehand. In this paper, we propose a content discovery method for GCIP. This method evaluates the relevancy between topics specified in user requests and topics representing IoT data used for creating contents, called matching, and presents the candidates for the desired contents based on the relevancy. Simulation results showed that appropriate contents can reliably be discovered in response to user’s request.12th International Workshop on Information Network Design (WIND-2020), in conjunction with 12th International Conference on Intelligent Networking and Collaborative Systems (INCoS-2020), August 31st - September 2nd, 2020, University of Victoria, Canada(新型コロナ感染拡大に伴い、現地開催中止

    Geolocation-centric Information Platform for Resilient Spatio-temporal Content Management

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    In IoT era, the growth of data variety is driven by cross-domain data fusion. In this paper, we advocate that “local production for local consumption (LPLC) paradigm” can be an innovative approach in cross-domain data fusion, and propose a new framework, geolocation-centric information platform (GCIP) that can produce and deliver diverse spatio-temporal content (STC). In the GCIP, (1) infrastructure-based geographic hierarchy edge network and (2) adhoc-based STC retention system are interplayed to provide both of geolocation-awareness and resiliency. Then, we discussed the concepts and the technical challenges of the GCIP. Finally, we implemented a proof-of-concepts of GCIP and demonstrated its efficacy through practical experiments on campus IPv6 network and simulation experiments

    Phase separation of an actin nucleator by junctional microtubules regulates epithelial function

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    Liquid-liquid phase separation (LLPS) is involved in various dynamic biological phenomena. In epithelial cells, dynamic regulation of junctional actin filaments tethered to the apical junctional complex (AJC) is critical for maintaining internal homeostasis against external perturbations; however, the role of LLPS in this process remains unknown. Here, after identifying a multifunctional actin nucleator, cordon bleu (Cobl), as an AJC-enriched microtubule-associated protein, we conducted comprehensive in vitro and in vivo analyses. We found that apical microtubules promoted LLPS of Cobl at the AJC, and Cobl actin assembly activity increased upon LLPS. Thus, microtubules spatiotemporally regulated junctional actin assembly for epithelial morphogenesis and paracellular barriers. Collectively, these findings established that LLPS of the actin nucleator Cobl mediated dynamic microtubule-actin cross-talk in junctions, which fine-tuned the epithelial barrier

    Recasting the cancer stem cell hypothesis: Unification using a continuum model of microenvironmental forces

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    Purpose of review Here, we identify shortcomings of standard compartment-based mathematical models of cancer stem-cells, and propose a continuous formalism which includes the tumor microenvironment. Recent findings Stem-cell models of tumor growth have provided explanations for various phenomena in oncology including, metastasis, drug- and radio-resistance, and functional heterogeneity in the face of genetic homogeneity. While some of the newer models allow for plasticity, or de-differentiation, there is no consensus on the mechanisms driving this. Recent experimental evidence suggests that tumor microenvironment factors like hypoxia, acidosis, and nutrient deprivation have causative roles. Summary To settle the dissonance between the mounting experimental evidence surrounding the effects of the microenvironment on tumor stemness, we propose a continuous mathematical model where we model microenvironmental perturbations like forces, which then shape the distribution of stemness within the tumor. We propose methods by which to systematically measure and characterize these forces, and show results of a simple experiment which support our claims

    The Quiescent Intracluster Medium in the Core of the Perseus Cluster

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    Clusters of galaxies are the most massive gravitationally-bound objects in the Universe and are still forming. They are thus important probes of cosmological parameters and a host of astrophysical processes. Knowledge of the dynamics of the pervasive hot gas, which dominates in mass over stars in a cluster, is a crucial missing ingredient. It can enable new insights into mechanical energy injection by the central supermassive black hole and the use of hydrostatic equilibrium for the determination of cluster masses. X-rays from the core of the Perseus cluster are emitted by the 50 million K diffuse hot plasma filling its gravitational potential well. The Active Galactic Nucleus of the central galaxy NGC1275 is pumping jetted energy into the surrounding intracluster medium, creating buoyant bubbles filled with relativistic plasma. These likely induce motions in the intracluster medium and heat the inner gas preventing runaway radiative cooling; a process known as Active Galactic Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus cluster core, which reveal a remarkably quiescent atmosphere where the gas has a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s is found across the 60 kpc image of the cluster core. Turbulent pressure support in the gas is 4% or less of the thermodynamic pressure, with large scale shear at most doubling that estimate. We infer that total cluster masses determined from hydrostatic equilibrium in the central regions need little correction for turbulent pressure.Comment: 31 pages, 11 Figs, published in Nature July
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