Spatial Interference Cancelation for Mobile Ad Hoc Networks: Perfect CSI

Interference between nodes directly limits the capacity of mobile ad hoc networks. This paper focuses on spatial interference cancelation with perfect channel state information (CSI), and analyzes the corresponding network capacity. Specifically, by using multiple antennas, zero-forcing beamforming is applied at each receiver for canceling the strongest interferers. Given spatial interference cancelation, the network transmission capacity is analyzed in this paper, which is defined as the maximum transmitting node density under constraints on outage and the signal-to-interference-noise ratio. Assuming the Poisson distribution for the locations of network nodes and spatially i.i.d. Rayleigh fading channels, mathematical tools from stochastic geometry are applied for deriving scaling laws for transmission capacity. Specifically, for small target outage probability, transmission capacity is proved to increase following a power law, where the exponent is the inverse of the size of antenna array or larger depending on the pass loss exponent. As shown by simulations, spatial interference cancelation increases transmission capacity by an order of magnitude or more even if only one extra antenna is added to each node.Comment: 6 pages; submitted to IEEE Globecom 200

Inhibition of vascular endothelial growth factor with a sequence-specific hypoxia response element antagonist

Vascular endothelial growth factor (VEGF) and its receptors have been implicated as key factors in tumor angiogenesis that are up-regulated by hypoxia. We evaluated the effects of DNA-binding small molecules on hypoxia-inducible transcription of VEGF. A synthetic pyrrole-imidazole polyamide designed to bind the hypoxia response element (HRE) was found to disrupt hypoxia-inducible factor (HIF) binding to HIRE. In cultured HeLa cells, this resulted in a reduction of VEGF mRNA and secreted protein levels. The observed effects were polyamide-specific and dose-dependent. Analysis of genome-wide effects of the HIRE-specific polyamide revealed that a number of hypoxia-inducible genes were down-regulated. Pathway-based regulation of hypoxia-inducible gene expression with DNA-binding small molecules may represent a new approach for targeting angiogenesis

Shot noise limited detection of OH using the technique of laser induced fluorescence

Nearly shot-noise limited detection of OH using the technique of laser-induced fluorescence is reported. A LIDAR configuration is used to excite fluorescence in a large volume and a narrow-bandwidth interference filter provides spectral discrimination. This arrangement alleviates the effect of ozone interference and facilitates image processing at relatively close distances. The detection limit is determined mainly by the shot-noise of the solar background. Ground-based measurements in Dearborn indicate a detection limit of better than 1 x 10 to the 6th power OH/cubic cm over a forty-minute acquisition period. Under favorable conditions, a comparable detection limit was also observed for airborne measurements

Laboratory and Field Tests of Multiple Corrosion Protection Systems for Reinforced Concrete Bridge Components and 2205 Pickled Stainless Steel

Multiple corrosion protection systems for reinforcing steel in concrete and the laboratory and field test methods used to compare these systems are evaluated. The systems include conventional steel, epoxy-coated reinforcement (ECR), ECR with a primer containing microencapsulated calcium nitrite, multiple coated reinforcement with a zinc layer underlying DuPont 8-2739 epoxy, ECR with a chromate pretreatment to improve adhesion between the epoxy and the steel, two types of ECR with high adhesion coatings produced by DuPont and Valspar, 2205 pickled stainless steel, concrete with water-cement ratios of 0.45 and 0.35, and three corrosion inhibitors (DCI-S, Rheocrete 222+, and Hycrete). The rapid macrocell test, three bench-scale tests (Southern Exposure, cracked beam, and ASTM G 109 tests), and a field test are used to evaluate the corrosion protection systems. The linear polarization resistance test is used to determine microcell corrosion activity. An economic analysis is performed to find the most cost-effective corrosion protection system. Corrosion performance of 2205 pickled stainless steel is evaluated for two bridges, the Doniphan County Bridge and Mission Creek Bridge in Kansas. The degree of correlation between results obtained with the Southern Exposure, cracked beam, and rapid macrocell tests is determined based on the results from a study by Balma et al. (2005). In uncracked mortar and concrete containing corrosion inhibitors, total corrosion losses are lower than observed at the same water-cement ratios in concrete with no inhibitors. In cracked concrete, however, the presence of corrosion inhibitors provides no or, at best, very limited protection to reinforcing steel. In uncracked concrete with a water-cement ratio of 0.35, corrosion losses are generally lower than observed at a watercement ratio of 0.45. In cracked concrete, a lower water-cement ratio provides only limited or no additional corrosion protection. Compared to conventional ECR, ECR with a primer containing microencapsulated calcium nitrite shows improvement in corrosion resistance in uncracked concrete with a w/c ratio of 0.35. At a higher w/c ratio (0.45), however, the primer provides corrosion protection for only a limited time. The three types of ECR with increased adhesion show no consistent improvement in corrosion resistance when compared to conventional ECR. The multiple coated reinforcement exhibits total corrosion losses between 1.09 and 14.5 times of the losses for conventional ECR. Corrosion potentials, however, show that the zinc provides protection to the underlying steel. A full evaluation of the system must await the end of the tests when the bars can be examined. Microcell corrosion losses measured with the linear polarization resistance test shows good correlation with macrocell corrosion losses obtained with the Southern Exposure and cracked beam tests. An economic analysis shows that, for the systems evaluated in the laboratory, the lowest cost option is provided by a 230-mm concrete deck reinforced with the following steels (all have the same cost): conventional ECR, ECR with a primer containing calcium nitrite, multiple coated reinforcement, or any of the three types of ECR with increased adhesion. Corrosion potential mapping results show that no corrosion activity is observed for either bridge deck. To date, the 2205p stainless steel has exhibited excellent corrosion performance. Total corrosion losses in the Southern Exposure and cracked beam tests at either 70 or 96 weeks are appropriate to evaluate the corrosion performance of corrosion protection systems. For the current comparisons, the rapid macrocell test was better at identifying differences between corrosion protection systems than either of the bench-scale tests

Framework for a Perceptive Mobile Network using Joint Communication and Radar Sensing

In this paper, we develop a framework for a novel perceptive mobile/cellular network that integrates radar sensing function into the mobile communication network. We propose a unified system platform that enables downlink and uplink sensing, sharing the same transmitted signals with communications. We aim to tackle the fundamental sensing parameter estimation problem in perceptive mobile networks, by addressing two key challenges associated with sophisticated mobile signals and rich multipath in mobile networks. To extract sensing parameters from orthogonal frequency division multiple access (OFDMA) and spatial division multiple access (SDMA) communication signals, we propose two approaches to formulate it to problems that can be solved by compressive sensing techniques. Most sensing algorithms have limits on the number of multipath signals for their inputs. To reduce the multipath signals, as well as removing unwanted clutter signals, we propose a background subtraction method based on simple recursive computation, and provide a closed-form expression for performance characterization. The effectiveness of these methods is validated in simulations.Comment: 14 pages, 12 figures, Journal pape

Phosphorylation and activation of protamine kinase by two forms of a myelin basic protein kinase from extracts of bovine kidney cortex

Two myelin basic protein kinases designated MBPK-1 and MBPK-2 were purified to apparent homogeneity from extracts of bovine kidney cortex. The purified preparations exhibited an apparent M(r) ≃ 40,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and ~42,000 (MBPK-1) and 45,000 (MBPK-2) by gel permeation chromatography. Up to 0.4 and 1.8 mol of phosphoryl groups were incorporated per mol of MBPK-1 and MBPK-2, respectively, on threonines following incubation with ATP. Autophosphorylation, incubation with protein phosphatase 2A2 (PP2A2), CD45, or T-cell protein tyrosine phosphatase did not affect MBPK-1 activity. Autophosphorylation increased by about 3-fold MBPK-2 activity. This autophosphorylation and activation was reversed by PP2A2 but not by CD45 or T-cell protein tyrosine phosphatase. MBPK-1 and MBPK-2 displayed a positive reaction with an antibody to mitogen-activated protein kinase. Purified preparations of protamine kinase were activated by about 1.5-6-fold and, after inactivation with PP2A2, were reactivated by about 30% by MBPK-1 and MBPK-2. Activation and reactivation correlated with the incorporation, respectively, of 0.1-0.5 and 0.5 mol of phosphoryl groups/mol of the protamine kinase on serines. The results show that MBPK-1 and MBPK-2 are protamine kinase-activating kinases and suggest that MBPK-1 and MBPK-2 may be related to mitogen-activated protein kinase