397 research outputs found

    Threats and perspective for the Internet of Things

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    Il paradigma di ubiquitous computing sta lentamente entrando nella vita di tutti i giorni, gli utenti sono sempre connessi e una nuova esigenza di monitoraggio e controllo sta nascendo. Dispositivi di comunicazione intelligenti, le reti domestiche multimediali e l’automazione industriale sono alcune coniugazioni possibili del paradigma di ubiquitous computing che sono ora disponibili per l’utente finale. La diffusione di questi sistemi ù infatti destinata a crescere, spinta da entrambi i mondi accademico e industriale la quantità di lavoro di ricerca in questo campo ù in aumento, e diverse aziende hanno messo le proprie soluzioni sul mercato. Nella visione di molti, l’utente sarebbe poi in grado di godere dei vantaggi di un sistema intelligente e impercettibile che si adatta all’ambiente ed ai suoi bisogni e unisce tutte le applicazioni e i servizi in un unico sistema integrato e facile da controllare. In questo lavoro vengono valutate alcune delle sfide architettoniche di questo nuovo modo di interagire tra l’utente e il suo ambiente circostante. Vengono mostrate la progettazione e la realizzazione di un SIP-based Home Gateway per il controllo remoto di Smart Objects in un ambiente domotico. È presentata anche un’architettura basata sul protocollo SIP per realizzare un sistema di domotica capace di interagire con dispositivi eterogenei e con varie interfacce utente, l’architettura si basa sull’uso del protocollo SIP come piano di controllo comune ed ù centrata sul SIP Gateway Home. Per valutare le capacità del sistema descritto abbiamo effettuato anche una valutazione delle prestazioni, considerando i due problemi principali per questo tipo di dispositivi: scalabilita ad un elevato numero di richieste di servizio per secondo e l’interferenza/coesistenza di dispositivi appartenenti a diverse tecnologie/standard (ZigBee, Bluetooth, e Wi-Fi) presenti sullo stesso dispositivo. Sono stati valutati anche i problemi di sicurezza attraverso lo studio sperimentale di un Intrusion Detection System per attenuare tali problemi

    Experimental Evaluation of a SIP-Based Home Gateway with Multiple Wireless Interfaces for Domotics Systems

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    In modern houses, the presence of sensors and actuators is increasing, whilecommunication servicesandentertainment systemshad long since settled into everyday life. The utilization of wireless communication technologies, such as ZigBee, Wi-Fi, and Bluetooth, is attractive because of their short installation times and low costs. The research is moving towards the integration of the various home appliances and devices into a single domotics system, able to exploit the cooperation among the diverse subsystems and offer the end-user a single multiservice platform. In this scenario, the paper presents the experimental evaluation of a domotics framework centered on a SIP-based home gateway (SHG). While SIP is used to build a common control plane, the SHG is in charge of translating the user commands from and to the specific domotics languages. The analysis has been devoted to assess both the performance of the SHG software framework and the negative effects produced by the simultaneous interference among the three widespread wireless technologies

    The role of the Arabidopsis FUSCA3 transcription factor during inhibition of seed germination at high temperature

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    Abstract Background Imbibed seeds integrate environmental and endogenous signals to break dormancy and initiate growth under optimal conditions. Seed maturation plays an important role in determining the survival of germinating seeds, for example one of the roles of dormancy is to stagger germination to prevent mass growth under suboptimal conditions. The B3-domain transcription factor FUSCA3 (FUS3) is a master regulator of seed development and an important node in hormonal interaction networks in Arabidopsis thaliana. Its function has been mainly characterized during embryonic development, where FUS3 is highly expressed to promote seed maturation and dormancy by regulating ABA/GA levels. Results In this study, we present evidence for a role of FUS3 in delaying seed germination at supraoptimal temperatures that would be lethal for the developing seedlings. During seed imbibition at supraoptimal temperature, the FUS3 promoter is reactivated and induces de novo synthesis of FUS3 mRNA, followed by FUS3 protein accumulation. Genetic analysis shows that FUS3 contributes to the delay of seed germination at high temperature. Unlike WT, seeds overexpressing FUS3 (ML1:FUS3-GFP) during imbibition are hypersensitive to high temperature and do not germinate, however, they can fully germinate after recovery at control temperature reaching 90% seedling survival. ML1:FUS3-GFP hypersensitivity to high temperature can be partly recovered in the presence of fluridone, an inhibitor of ABA biosynthesis, suggesting this hypersensitivity is due in part to higher ABA level in this mutant. Transcriptomic analysis shows that WT seeds imbibed at supraoptimal temperature activate seed-specific genes and ABA biosynthetic and signaling genes, while inhibiting genes that promote germination and growth, such as GA biosynthetic and signaling genes. Conclusion In this study, we have uncovered a novel function for the master regulator of seed maturation, FUS3, in delaying germination at supraoptimal temperature. Physiologically, this is important since delaying germination has a protective role at high temperature. Transcriptomic analysis of seeds imbibed at supraoptimal temperature reveal that a complex program is in place, which involves not only the regulation of heat and dehydration response genes to adjust cellular functions, but also the activation of seed-specific programs and the inhibition of germination-promoting programs to delay germination

    The embryonic leaf identity gene FUSCA3 regulates vegetative phase transitions by negatively modulating ethylene-regulated gene expression in Arabidopsis

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    <p>Abstract</p> <p>Background</p> <p>The embryonic temporal regulator <it>FUSCA3 </it>(<it>FUS3</it>) plays major roles in the establishment of embryonic leaf identity and the regulation of developmental timing. Loss-of-function mutations of this B3 domain transcription factor result in replacement of cotyledons with leaves and precocious germination, whereas constitutive misexpression causes the conversion of leaves into cotyledon-like organs and delays vegetative and reproductive phase transitions.</p> <p>Results</p> <p>Herein we show that activation of FUS3 after germination dampens the expression of genes involved in the biosynthesis and response to the plant hormone ethylene, whereas a loss-of-function <it>fus3 </it>mutant shows many phenotypes consistent with increased ethylene signaling. This <it>FUS3</it>-dependent regulation of ethylene signaling also impinges on timing functions outside embryogenesis. Loss of <it>FUS3 </it>function results in accelerated vegetative phase change, and this is again partially dependent on functional ethylene signaling. This alteration in vegetative phase transition is dependent on both embryonic and vegetative <it>FUS3 </it>function, suggesting that this important transcriptional regulator controls both embryonic and vegetative developmental timing.</p> <p>Conclusion</p> <p>The results of this study indicate that the embryonic regulator <it>FUS3 </it>not only controls the embryonic-to-vegetative phase transition through hormonal (ABA/GA) regulation but also functions postembryonically to delay vegetative phase transitions by negatively modulating ethylene-regulated gene expression.</p

    Fast and slow gating are inherent properties of the pore module of the K+ channel Kcv

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    Kcv from the chlorella virus PBCV-1 is a viral protein that forms a tetrameric, functional K+ channel in heterologous systems. Kcv can serve as a model system to study and manipulate basic properties of the K+ channel pore because its minimalistic structure (94 amino acids) produces basic features of ion channels, such as selectivity, gating, and sensitivity to blockers. We present a characterization of Kcv properties at the single-channel level. In symmetric 100 mM K+, single-channel conductance is 114 ± 11 pS. Two different voltage-dependent mechanisms are responsible for the gating of Kcv. “Fast” gating, analyzed by ÎČ distributions, is responsible for the negative slope conductance in the single-channel current–voltage curve at extreme potentials, like in MaxiK potassium channels, and can be explained by depletion-aggravated instability of the filter region. The presence of a “slow” gating is revealed by the very low (in the order of 1–4%) mean open probability that is voltage dependent and underlies the time-dependent component of the macroscopic current

    Ethylene and the regulation of plant development

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    Often considered an 'aging' hormone due to its role in accelerating such developmental processes as ripening, senescence, and abscission, the plant hormone ethylene also regulates many aspects of growth and development throughout the life cycle of the plant. Multiple mechanisms have been identified by which transcriptional output from the ethylene signaling pathway can be tailored to meet the needs of particular developmental pathways. Of special interest is the report by Lumba et al. in BMC Biology on how vegetative transitions are regulated through the effect of the transcription factor FUSCA3 on ethylene-controlled gene expression, providing an elegant example of how hormonal control can be integrated into a developmental pathway

    AUTOMATED FREQUENCY COORDINATION (AFC) FOR OPEN PIT MINING

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    The techniques are described herein to facilitate the use of 6GHz frequencies in deployments, such as strip mines, where Access Point (AP) locations change, while still complying with Automated Frequency Coordination (AFC) requirements

    MOVING/ROTATING ANTENNAS FOR WIRELESS ACCESS POINTS

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    Conventionally, the position and orientation of antennas for wireless access points depends on the position in which a wireless access point is oriented during installation and typically does not change unless the positioning of the wireless access point is changed. Thus, wireless antenna position/orientation typically remains static once an access point is installed. Techniques proposed herein introduce a sensor fusion approach for controlling the direction/orientation of wireless access point antennas in order to improve wireless communications for wireless networks

    Phycodnavirus Potassium Ion Channel Proteins Question the Virus Molecular Piracy Hypothesis

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    Phycodnaviruses are large dsDNA, algal-infecting viruses that encode many genes with homologs in prokaryotes and eukaryotes. Among the viral gene products are the smallest proteins known to form functional K+ channels. To determine if these viral K+ channels are the product of molecular piracy from their hosts, we compared the sequences of the K+ channel pore modules from seven phycodnaviruses to the K+ channels from Chlorella variabilis and Ectocarpus siliculosus, whose genomes have recently been sequenced. C. variabilis is the host for two of the viruses PBCV-1 and NY-2A and E. siliculosus is the host for the virus EsV-1. Systematic phylogenetic analyses consistently indicate that the viral K+ channels are not related to any lineage of the host channel homologs and that they are more closely related to each other than to their host homologs. A consensus sequence of the viral channels resembles a protein of unknown function from a proteobacterium. However, the bacterial protein lacks the consensus motif of all K+ channels and it does not form a functional channel in yeast, suggesting that the viral channels did not come from a proteobacterium. Collectively, our results indicate that the viruses did not acquire their K+ channel-encoding genes from their current algal hosts by gene transfer; thus alternative explanations are required. One possibility is that the viral genes arose from ancient organisms, which served as their hosts before the viruses developed their current host specificity. Alternatively the viral proteins could be the origin of K+ channels in algae and perhaps even all cellular organisms

    New polycyclic dual inhibitors of the wild type and the V27A mutant M2 channel of the influenza A virus with unexpected binding mode

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    Two new polycyclic scaffolds were synthesized and evaluated as anti-influenza A compounds. The 5-azapentacyclo[6.4.0.02,10.03,7.09,11]dodecane derivatives were only active against the wild-type M2 channel in the low-micromolar range. However, some of the 14-azaheptacyclo[8.6.1.02,5.03,11.04,9.06,17.012,16]heptadecane derivatives were dual inhibitors of the wild-type and the V27A mutant M2 channels. The antiviral activity of these molecules was confirmed by cell culture assays. Their binding mode was analysed through molecular dynamics simulations, which showed the existence of distinct binding modes in the wild type M2 channel and its V27A variant
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