We have developed a highly effective method for in vivo gene silencing in the spinal cord and dorsal root ganglia (DRG) by a cationic lipid facilitated delivery of synthetic, small interfering RNA (siRNA). A siRNA to the delta opioid receptor (DOR), or a mismatch RNA, was mixed with the transfection reagent, i-FectTM (vehicle), and delivered as repeated daily bolus doses (0.5 mug to 4 mug) via implanted intrathecal catheter to the lumbar spinal cord of rats. Twenty-four hours after the last injection, rats were tested for antinociception by the DOR selective agonist, D-Ala2, Glu4]deltorphin II (DELT), or the mu opioid receptor (MOR) selective agonist, D-Ala2, N-Me-Phe4, Gly-ol5]enkephalin (DAMGO). Pretreatment with the siRNA, but not the mismatch RNA or vehicle alone, blocked DELT antinociception dose-dependently. The latter was concomitant with a reduction in the spinal immunoreactivity and receptor density of DOR, and in DOR transcripts in the lumbar DRG and spinal dorsal horn. Neither siRNA nor mismatch RNA pretreatment altered spinal immunoreactivity of MOR or antinociception by spinal DAMGO, and had no effect on the baseline thermal nociceptive threshold. The inhibition of function and expression of DOR by siRNA was reversed by 72 hr after the last RNA injection. The uptake of fluorescence-tagged siRNA was detected in both DRG and spinal cord. The low effective dose of siRNA/i-FectTM complex reflects an efficient delivery of the siRNA to peripheral and spinal neurons, produced no behavioral signs of toxicity. This delivery method may be optimized for other gene targets.

Recently, cholesterol metabolism has been shown to modulate the infection of several viruses and there is growing evidence that inflammatory response to infection also modulates lipid metabolism. However little is known about the role of inflammatory processes in modulating lipid metabolism and their consequences for the viral infection. This study investigates host-lipid viral interaction pathways using mouse cytomegalovirus, a large double-stranded DNA genome, which represents one of the few models for a natural infection of its natural host. In this study, transcriptomic and lipidomic profiling of macrophages shows that there is a specific coordinated regulation of the sterol pathways upon viral infection or treatment with IFNγ or β (but not TNFα, IL1β or IL6) resulting in the decrease of free cellular cholesterol. Furthermore, we show that pharmacological and RNAi inhibition of the sterol pathway augments protection against infection in vitro and in vivo and we identified that the prenylation branch of the sterol metabolic network was involved in the protective response. Finally, we show that genetic knock out of IFNβ results in a partial reduction while genetic knock out of Ifnar1 completely abolishes the reduction of the sterol biosynthetic activity upon infection. Overall these results support a role for part of the sterol metabolic network in protective immunity and show that type 1 IFN signalling is both necessary and sufficient for reducing the sterol metabolic network upon infection; thereby linking the sterol pathway with IFN defence responses.

Security APIs are designed to enable the storage and processing of confidential data without that data becoming known to individuals who are not permitted to obtain it, and are central to the operation of Automated Teller Machines (ATM) networks, Electronic Point of Sale (EPOS) terminals, set-top boxes for subscription-based TV, pre-payment utility meters, and electronic ticketing for an increasing number of public transport systems (e.g., Oyster in London). However, since the early 2000s, it has become clear that many of the security APIs in widespread use contain subtle flaws which allow malicious individuals to subvert the security restrictions and obtain confidential data that should be protected. In this thesis, we attempt to address this problem by presenting a type system in which specific security properties are guaranteed to be enforced by security APIs that are well-typed. Since type-checking is a form of static analysis, it does not suffer from the scalability issues associated with approaches that simulate interactions between a security API and one or more malicious individuals. We also show how our type system can be used to model an existing security API and provide the same guarantees of security that the API authors proved it upholds. This result follows directly from producing a well-typed implementation of the API, and demonstrates how our type system provides security guarantees without requiring additional API-specific proofs.

ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / This paper describes the methodology and the results of the interferences analysis that the JASON3 spacecraft has to deal with, as part of the PROTEUS platform series, sharing frequencies, modulation schemes and ground network.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper will present measured data in an adjacent channel interference (ACI) environment for both filtered continuous phase frequency shift keying (CPFSK) and Feher’s patented quadrature phase shift keying (FQPSK-B) [1]. The quantity measured was bit error probability (BEP) versus signal energy per bit to noise power spectral density ratio (E(b)/N(o)). The interferers were either CPFSK or FQPSK-B signals. The results presented in this paper will be for bit rates of 5 Mb/s, one interferer 20 dB larger than desired signal, various channel spacings, and two different telemetry receivers. The ACI test effort will collect data sets at several bit rates and with one and two interferers. The results will be useful to system designers and range operators as they attempt to maximize the number of Mb/s that can be simultaneously transmitted in the telemetry bands.

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / Automatic spectrum management and monitoring systems are very useful to manage frequencies at test ranges and assure interference-free transmission of telemetry signals. Spectrum management systems assign telemetry frequencies using database information on available and occupied channels and analysis tools which can determine whether a data link will support telemetry. Modern, DSP-based spectrum monitoring systems, in fixed or mobile configurations, automate the process of performing spectrum occupancy to verify clear channels and identify and locate sources of interference; they are integrated with and utilize the management system database. Such systems are important to assure reliable communications channels for telemetry.

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / This paper presents a method for the management of mixed networks as envisioned in future iNET applications and develops a scheme for global optimal performance for features that include signal to Noise Ratio (SNR), Quality of service (QoS), and Interference. This scheme demonstrates potential for significant enhancement of performance for dense traffic environments envisioned in future telemetry applications. Previous research conducted at Morgan State University has proposed a cellular and Ad hoc mixed network for optimum capacity and coverage using two distance measures: QoS and SNR. This paper adds another performance improvement technique, interference, as a third distance measure using an analytical approach and using extensive simulation with MATLAB. This paper also addresses solutions where performance parameters are correlated and uncorrelated. The simulations show the optimization of mixed network nodes using distance, traffic and interference measures all at one time. This has great potential in mobile communication and iNET.

This dissertation investigates how to optimize flow-level performance in interference dominated wireless networks serving dynamic traffic loads. The schemes presented in this dissertation adapt to long-term (hours) spatial load variations, and the main metrics of interest are the file transfer delay or average flow throughput and the mean power expended by the transmitters. The first part presents a system level approach to interference management in an infrastructure based wireless network with full frequency reuse. The key idea is to use loose base station coordination that is tailored to the spatial load distribution and the propagation environment to exploit the diversity in a user population's sensitivity to interference. System architecture and abstractions to enable such coordination are developed for both the downlink and the uplink cases, which present differing interference characteristics. The basis for the approach is clustering and aggregation of traffic loads into classes of users with similar interference sensitivities that enable coarse grained information exchange among base stations with greatly reduced communication overheads. The dissertation explores ways to model and optimize the system under dynamic traffic loads where users come and go resulting in interference induced performance coupling across base stations. Based on extensive system-level simulations, I demonstrate load-dependent reductions in file transfer delay ranging from 20-80% as compared to a simple baseline not unlike systems used in the field today, while simultaneously providing more uniform coverage. Average savings in user power consumption of up to 75% are achieved. Performance results under heterogeneous spatial loads illustrate the importance of being traffic and environment aware. The second part studies the impact of policies to associate users with base stations/access points on flow-level performance in interference limited wireless networks. Most research in this area has used static interference models (i.e., neighboring base stations are always active) and resorted to intuitive objectives such as load balancing. In this dissertation, it is shown that this can be counter productive, and that asymmetries in load can lead to significantly better performance in the presence of dynamic interference which couples the transmission rates experienced by users at various base stations. A methodology that can be used to optimize the performance of a class of coupled systems is proposed, and applied to study the user association problem. It is demonstrated that by properly inducing load asymmetries, substantial performance gains can be achieved relative to a load balancing policy (e.g., 15 times reduction in mean delay). A novel measurement based, interference-aware association policy is presented that infers the degree of interference induced coupling and adapts to it. Systematic simulations establish that both the optimized static and interference-sensitive, adaptive association policies substantially outperform various proposed dynamic policies and that these results are robust to changes in file size distributions, channel parameters, and spatial load distributions. / text

Multiple-Input Multiple-Output (MIMO) communication uses multiple transmit and receive antennas to improve the throughput in wireless channels. In cellular networks, self-interference greatly degrades MIMO's potential gain, especially in multiuser MIMO systems where multiple users in each cell share the spatial channel in order to maximize the total throughput. In a multiuser MIMO downlink, the two main causes of this self-interference are residual inter-user interference due to imperfect spatial separation between the users and other-cell interference due to cochannel transmissions in other cells. This dissertation develops adaptive transmission strategies to deal with both residual inter-user interference and other-cell interference in cellular MIMO networks. For the residual inter-user interference caused by imperfect channel state information at the transmitter, we explicitly characterize the impact of channel quantization and feedback delay. Achievable ergodic rates for both single-user and multiuser MIMO systems with different channel state information are derived. Adaptive switching between single-user and multiuser MIMO modes is proposed to improve the throughput, based on the accuracy of the available channel information. It is then extended to a multi-mode transmission strategy which adaptively adjusts the number of active users to control residual interference and provide additional array gain. To adaptively minimize the other-cell interference, two practical base station coordination strategies are proposed. The first is a cluster based coordination algorithm with different coordination strategies for cluster interior and cluster edge users. It performs full intra-cluster coordination for enhancing the sum throughput and limited inter-cluster coordination for reducing the interference for cluster edge users. A multi-cell linear precoder is designed to perform the coordination. The second is an adaptive intercell interference cancellation strategy, where multiple base stations jointly select transmission techniques based on user locations to maximize the sum throughput. Spatial interference cancellation is applied to suppress other-cell interference. Closed-form expressions are derived for the achievable throughput, and the proposed adaptive strategy is shown to provide significant average and edge throughput gain. The feedback design to assist the interference cancellation is also discussed. / text

在無線區域網路的範疇，IEEE 802.11是一個主要的媒介存取控制協定。然而在隨意式多跳接的網路中，IEEE 802.11面臨更嚴重的hidden terminal和exposed terminal problems，而這些問題主因都源自於過大的訊號干擾範圍與過大的訊號感應範圍。在這篇論文裡，我們提出一個可調式的媒介存取控制協定，針對IEEE 802.11 RTS/CTS handshake機制做簡單地修改，使得IEEE 802.11 devices可以依據週遭的傳收狀態動態調整自身的傳送和接收行為。實驗結果顯示我們的方法使原來的 802.11 減少了互相干擾的情形並且提升了系統的效能。 / The IEEE 802.11 standard is the most popular Medium Access Control (MAC) protocol for wireless local area networks. However, in multihop wireless ad hoc networks, the IEEE 802.11 MAC protocol will suffer from more serious hidden terminal and exposed terminal problems than those in single hop WLANs. More specifically, it is due to the large interference range and the large carrier sensing range. In this thesis, we propose an adaptive IEEE 802.11 MAC (AMAC) that makes two simple modifications of IEEE 802.11 RTS/CTS handshake to dynamically adjust the transmission and reception according to the shared medium status near transmitter and receiver, respectively. Simulation results show that our method can lessen interferences and increase system throughput as compared with IEEE 802.11 MAC.