112 research outputs found
Energy Efficiency of Network Cooperation for Cellular Uplink Transmissions
There is a growing interest in energy efficient or so-called "green" wireless
communication to reduce the energy consumption in cellular networks. Since
today's wireless terminals are typically equipped with multiple network access
interfaces such as Bluetooth, Wi-Fi, and cellular networks, this paper
investigates user terminals cooperating with each other in transmitting their
data packets to a base station (BS) by exploiting the multiple network access
interfaces, referred to as inter-network cooperation, to improve the energy
efficiency in cellular uplink transmission. Given target outage probability and
data rate requirements, we develop a closed-form expression of energy
efficiency in Bits-per-Joule for the inter-network cooperation by taking into
account the path loss, fading, and thermal noise effects. Numerical results
show that when the cooperating users move towards to each other, the proposed
inter-network cooperation significantly improves the energy efficiency as
compared with the traditional non-cooperation and intra-network cooperation.
This implies that given a certain amount of bits to be transmitted, the
inter-network cooperation requires less energy than the traditional
non-cooperation and intra-network cooperation, showing the energy saving
benefit of inter-network cooperation.Comment: in Proceedings of the 2013 IEEE International Conference on
Communications (IEEE ICC 2013), Budapest, Hungary, June 201
Outage Analysis of Multi-Relay Selection for Cognitive Radio with Imperfect Spectrum Sensing
In this paper, we examine the outage performance of a cognitive relay
network, which is comprised of a secondary transmitter (ST), multiple
decode-and-forward (DF) relays and a secondary destination (SD). We propose a
multi-relay selection scheme for the cognitive relay network, where multiple
relays are selected and used to participate in forwarding the secondary
transmission from ST to SD. A closed-form expression of the outage probability
for the proposed multi-relay selection under imperfect spectrum sensing is
derived in Rayleigh fading environments. For comparison purposes, the
conventional direct transmission and the best-relay selection are also
considered as benchmarks. Numerical results show that as the spectrum sensing
performance improves with an increasing detection probability and/or a
decreasing false alarm probability, the outage probabilities of the proposed
multi-relay selection as well as the direct transmission and the best-relay
selection schemes all decrease accordingly. It is also demonstrated that the
proposed multi-relay selection significantly outperforms the conventional
approaches in terms of the outage probability.Comment: 5 page
Dichlorido[N′-(3,5-dichloro-2-hydroxyÂbenzylÂidene)pyridine-4-carbohydrazide-κN](1,10-phenanthroline-κ2 N,N′)cobalt(II) methanol monosolvate
In the title compound, [CoCl2(C13H9Cl2N3O2)2(C12H8N2)]·CH3OH, the CoII atom is octahedrally coordinated by two N atoms from the pyridyl rings of the tridentate N′-(3,5-dichloro-2-hydroxyÂbenzylÂidene)pyridine-4-carbohydrazide (H2
L) ligand, two N atoms from the 1,10-phenanthroline ligand and two chloride ions. The acylÂhydrazone groups are not involved into the coordination of the metal ion. In the crystal packing an extended three-dimensional network formed by N—H⋯Cl, N—H⋯O, O—H⋯N, O—H⋯N and O—H⋯Cl hydrogen bonds is observed
Optimal scheduling for multiple description video streams in wireless multihop networks
International audience— In this work, we investigate the optimal system scheduling for competing multiple description (MD) video streams in a resource-limited wireless multihop network. By joint optimization of MD, rate control and multipath routing, optimal joint rate control and routing algorithm is proposed to solve this problem with constraints that arise from the MD streams among multiple users via multiple paths. We design this joint algorithm in a distributed manner that is amenable to on-line implementation for wireless networks
Application of citrate as a tricarboxylic acid (TCA) cycle intermediate, prevents diabetic-induced heart damages in mice
Objective(s):Higher cellular reactive oxygen species (ROS) levels is important in reducing cellular energy charge (EC) by increasing the levels of key metabolic protein, and nitrosative modifications, and have been shown to damage the cardiac tissue of diabetic mice. However, the relation between energy production and heart function is unclear.
Materials and Methods:Streptozotocin (STZ, 150 mg/kg body weight) was injected intraperitoneally once to mice that had been fasted overnight for induction of diabetes. After diabetic induction, mice received citrate (5 µg/kg) through intraperitoneal injection every other day for 5 weeks. The caspase-3, plasminogen activator inhibitor 1 (PAI1), protein kinase B (PKB), commonly known as AKT and phosphorylated-AKT (p-AKT) proteins were examined to elucidate inflammation and apoptosis in the heart. For histological analysis, heart samples were fixed with 10% formalin and stained with hematoxylin-eosin (HE) and Sirius red to assess pathological changes and fibrosis. The expression levels[AGA1] of marker proteins, tyrosine nitration, activity of ATP synthase and succinyl-CoA:3-ketoacid coenzyme A transferase-1 (SCOT), and EC were measured.
Results:Intraperitoneal injection of citrate significantly reduced caspase-3 and PAI-1 protein levels and increased p-AKT level on the 5th week; EC in the heart was found to be increased as well. Further, the expression level, activity, and tyrosine nitration of ATP synthase and SCOT were not affected after induction of diabetes.
Conclusion: Results indicate that application of citrate, a tricarboxylic acid (TCA) cycle intermediate, might alleviate cardiac dysfunction by reducing cardiac inflammation, apoptosis, and increasing cardiac EC
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