316 research outputs found
Spectrum Sharing between Cooperative Relay and Ad-hoc Networks: Dynamic Transmissions under Computation and Signaling Limitations
This paper studies a spectrum sharing scenario between a cooperative relay
network (CRN) and a nearby ad-hoc network. In particular, we consider a dynamic
spectrum access and resource allocation problem of the CRN. Based on sensing
and predicting the ad-hoc transmission behaviors, the ergodic traffic collision
time between the CRN and ad-hoc network is minimized subject to an ergodic
uplink throughput requirement for the CRN. We focus on real-time implementation
of spectrum sharing policy under practical computation and signaling
limitations. In our spectrum sharing policy, most computation tasks are
accomplished off-line. Hence, little real-time calculation is required which
fits the requirement of practical applications. Moreover, the signaling
procedure and computation process are designed carefully to reduce the time
delay between spectrum sensing and data transmission, which is crucial for
enhancing the accuracy of traffic prediction and improving the performance of
interference mitigation. The benefits of spectrum sensing and cooperative relay
techniques are demonstrated by our numerical experiments.Comment: 5 pages, 3 figures, to appear in IEEE International Conference on
Communications (ICC 2011
Protective effects of Zhuifeng tougu on collagen-induced arthritis in DBA/1 mice
Purpose: To investigate the protective effects of Zhuifengtougu (ZFTG) on rheumatoid arthritis (RA) using collagen-induced arthritis (CIA) mouse modelMethods: DBA/1 mice were randomly divided into 7 treatment groups (n = 8): normal, positive control (CIA mice), CIA mice + total glucosides of peony (TGP), CIA mice + cyclophosphamide (CPA), CIA mice + 100 mg/kg ZFTG, CIA mice + 200 mg/kg ZFTG, and CIA mice + 400 mg/kg ZFTG. The serum levels of interleukin (IL)-1β, IL-6, IL-10, IL-17 and tumor necrosis factor (TNF)-αwere measured by enzyme-linked immunosorbent assay (ELISA). Western blot was used to determine the protein expression of B-cell lymphoma 2 (BCL-2), p53 and first apoptosis signal receptor (Fas).Results: Following drug administration, the arthritic index in CIA mice administered low-dose, mediumdose, or high-dose ZFTG (1.53 – 1.87), TGP (1.75 ± 0.42), or CPA (1.52 ± 0.36) was reduced significantly (p < 0.05), compared with positive control group (5.66 ± 0.73; p < 0.01). Levels of IL-1β, IL-6, IL-17 and TNF-α in serum and expression of Bcl-2, p53, and Fas were also significantly decreased (p < 0.05) in CIA mice administered ZFTG, TGP, or CPA, whereas IL-10 levels increased.Conclusion: These results suggest that ZFTG exhibit anti-rheumatic activity in CIA mice via modulation of inflammatory cytokines (IL-1β, IL-6, IL-10, IL-17 and TNF-α) and downregulation of the expressions of Bcl-2, p53, and Fas. Thus, ZFTG is a potential candidate drug for the treatment of RA.Keywords: Zhuifengtougu pill, Rheumatoid arthritis, Cytokines, Bcl-2, Fas, p5
Optimal Distributed Resource Allocation for Decode-and-Forward Relay Networks
This paper presents a distributed resource allocation algorithm to jointly
optimize the power allocation, channel allocation and relay selection for
decode-and-forward (DF) relay networks with a large number of sources, relays,
and destinations. The well-known dual decomposition technique cannot directly
be applied to resolve this problem, because the achievable data rate of DF
relaying is not strictly concave, and thus the local resource allocation
subproblem may have non-unique solutions. We resolve this non-strict concavity
problem by using the idea of the proximal point method, which adds quadratic
terms to make the objective function strictly concave. However, the proximal
solution adds an extra layer of iterations over typical duality based
approaches, which can significantly slow down the speed of convergence. To
address this key weakness, we devise a fast algorithm without the need for this
additional layer of iterations, which converges to the optimal solution. Our
algorithm only needs local information exchange, and can easily adapt to
variations of network size and topology. We prove that our distributed resource
allocation algorithm converges to the optimal solution. A channel resource
adjustment method is further developed to provide more channel resources to the
bottleneck links and realize traffic load balance. Numerical results are
provided to illustrate the benefits of our algorithm
Optimal Real-time Spectrum Sharing between Cooperative Relay and Ad-hoc Networks
Optimization based spectrum sharing strategies have been widely studied.
However, these strategies usually require a great amount of real-time
computation and significant signaling delay, and thus are hard to be fulfilled
in practical scenarios. This paper investigates optimal real-time spectrum
sharing between a cooperative relay network (CRN) and a nearby ad-hoc network.
Specifically, we optimize the spectrum access and resource allocation
strategies of the CRN so that the average traffic collision time between the
two networks can be minimized while maintaining a required throughput for the
CRN. The development is first for a frame-level setting, and then is extended
to an ergodic setting. For the latter setting, we propose an appealing optimal
real-time spectrum sharing strategy via Lagrangian dual optimization. The
proposed method only involves a small amount of real-time computation and
negligible control delay, and thus is suitable for practical implementations.
Simulation results are presented to demonstrate the efficiency of the proposed
strategies.Comment: One typo in the caption of Figure 5 is correcte
8-Cl-Adenosine enhances 1,25-dihydroxyvitamin D(3)-induced growth inhibition without affecting 1,25-dihydroxyvitamin D(3)-stimulated differentiation of primary mouse epidermal keratinocytes
BACKGROUND: Epidermal keratinocytes continuously proliferate and differentiate to form the mechanical and water permeability barrier that makes terrestrial life possible. In certain skin diseases, these processes become dysregulated, resulting in abnormal barrier formation. In particular, skin diseases such as psoriasis, actinic keratosis and basal and squamous cell carcinomas are characterized by hyperproliferation and aberrant or absent differentiation of epidermal keratinocytes. We previously demonstrated that 8-Cl-adenosine (8-Cl-Ado) can induce keratinocyte growth arrest without inducing differentiation. RESULTS: To determine if this agent might be useful in treating hyperproliferative skin disorders, we investigated whether 8-Cl-Ado could enhance the ability of 1,25-dihydroxyvitamin D(3 )[1,25(OH)(2)D(3)], a known keratinocyte differentiating agent and a clinical treatment for psoriasis, to inhibit keratinocyte growth. We found that low concentrations of 8-Cl-Ado and 1,25(OH)(2)D(3 )appeared to act additively to reduce proliferation of primary mouse epidermal keratinocytes. However, another agent (transforming growth factor-beta) that triggers growth arrest without inducing differentiation also coincidentally inhibits differentiation elicited by other agents; inhibition of differentiation is suboptimal for treating skin disorders, as differentiation is often already reduced. Thus, we determined whether 8-Cl-Ado also decreased keratinocyte differentiation induced by 1,25(OH)(2)D(3), as measured using the early and late differentiation markers, keratin 1 protein levels and transglutaminase activity, respectively. 8-Cl-Ado did not affect 1,25(OH)(2)D(3)-stimulated keratin 1 protein expression or transglutaminase activity. CONCLUSIONS: Our results suggest that 8-Cl-Ado might be useful in combination with differentiating agents for the treatment of hyperproliferative disorders of the skin
Recommendation Scheme Based on Converging Properties for Contents Broadcasting
Popular videos are often clicked by a mount of users in a short period. With
content recommendation, the popular contents could be broadcast to the
potential users in wireless network, to save huge transmitting resource. In
this paper, the contents propagation model is analyzed due to users' historical
behavior, location, and the converging properties in wireless data
transmission, with the users' communication log in the Chinese commercial
cellular network. And a recommendation scheme is proposed to achieve high
energy efficiency.Comment: 6 pages. This work is present at 2015 International Workshop on
Networking Issues in Multimedia Entertainment (NIME'15
A Unified Approach to Optimal Opportunistic Spectrum Access under Collision Probability Constraint in Cognitive Radio Systems
We consider a cognitive radio system with one primary channel and one secondary user, and then we introduce a channel-usage pattern model and a fundamental access scheme in this system. Based on this model and fundamental access scheme, we study optimal opportunistic spectrum access problem and formulate it as an optimization problem that the secondary user maximizes spectrum holes utilization under the constraint of collision tolerable level. And then we propose a unified approach to solve this optimization problem. According to the solution of the optimization problem, we analyze and present optimal opportunistic spectrum access algorithms in several cases that the idle period follows uniform distribution, exponential distribution, and Pareto or generalized Pareto distribution. Theoretical analysis and simulation results both show that the optimal opportunistic spectrum access algorithms can maximize spectrum holes utilization under the constraint that the collision probability is bounded below collision tolerable level. The impact of sensing error is also analyzed by simulation
KINEMATICAL RESEARCH ON HURDLE CLEARANCE TECHNIQUES OF ELITE CHINESE ATHLETE IN 100M HURDLES
INTRODUCTION: Although Jing Liu was the champion of women’s 100m Hurdle in 2007 Asian Games, the performance did not get the level of the world elite athletes. This investigation was conducted to find the technique defects and thus to serve athletic training through kinematical analysis to hurdle clearance techniques of Jing Liu
The Regenerating Gene Iα Is Overexpressed in Atrophic Gastritis Rats with Hypergastrinemia
The role of gastrin on the development of atrophic gastritis (AG) and its relationship with the expression of RegIα in vivo remain unclear. We established experimental AG in rats by combination administration with sodium salicylate, alcohol, and deoxycholate sodium. The mean score of inflammation in gastric antrum in AG rats was significantly elevated (P < 0.05), while the number of glands dramatically decreased (P < 0.05). In addition, the cell proliferation in gastric glands was increased in experimental AG rats, as determined by immunohistochemistry staining of PCNA and GS II. The level of serum gastrin in AG rats was significantly elevated relative to that of normal rats (P < 0.01). Moreover, the expression of RegIα protein and its receptor mRNA was increased in gastric tissues in AG rats (P < 0.05). Taken together, we demonstrated that the overexpression of Reglα is related with hypergastrinemia in AG rats
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