9,200 research outputs found
High-Efficient Parallel CAVLC Encoders on Heterogeneous Multicore Architectures
This article presents two high-efficient parallel realizations of the context-based adaptive variable length coding (CAVLC) based on heterogeneous multicore processors. By optimizing the architecture of the CAVLC encoder, three kinds of dependences are eliminated or weaken, including the context-based data dependence, the memory accessing dependence and the control dependence. The CAVLC pipeline is divided into three stages: two scans, coding, and lag packing, and be implemented on two typical heterogeneous multicore architectures. One is a block-based SIMD parallel CAVLC encoder on multicore stream processor STORM. The other is a component-oriented SIMT parallel encoder on massively parallel architecture GPU. Both of them exploited rich data-level parallelism. Experiments results show that compared with the CPU version, more than 70 times of speedup can be obtained for STORM and over 50 times for GPU. The implementation of encoder on STORM can make a real-time processing for 1080p @30fps and GPU-based version can satisfy the requirements for 720p real-time encoding. The throughput of the presented CAVLC encoders is more than 10 times higher than that of published software encoders on DSP and multicore platforms
Evaluation of antimicrobial efficacy of antibiotics and calcium hydroxide against enterococcus faecalis biofilm in dentine
The objective of this study was to investigate the antimicrobial efficacy of erythromycin, oxytetracycline and calcium hydroxide [Ca(OH)2] against Enterococcus faecalis biofilm in dentine. E. faecalis ATCC 29212 (American type culture collection) was inoculated into standard tooth sections and incubated in aerobic atmosphere at 37°C for 21 days. The infected tooth sections were then exposed to the test agents for 5 and 10 min. The colony forming units (CFU) after the exposure periods at three different depths <100 μm, 100-350 μm and 350-500 μm were enumerated. After 5 min of exposure, both antibiotics had significantly lower CFU count than Ca(OH)2 solution at three dentinal depths. Comparing with the oxytetracycline, the CFU count of the erythromycin was significantly (p<0.05) lower at the depth of 100-500 μm. Similarly, after 10 min of exposure, erythromycin had significantly lower CFU count (p<0.05) at three dentinal depths. Oxytetracycline showed significantly lower CFU count than Ca(OH)2 at 100 μm depth. Comparing with the two exposure times, the erythromycin and Ca(OH)2 groups showed significant lower CFU counts after 10 min of exposure in the antimicrobial agents to 5 min. In conclusion, both antibiotics show better antimicrobial activity than Ca(OH)2 in removing the E. faecalis biofilm in dentine
Kinetic Monte Carlo Simulations of Crystal Growth in Ferroelectric Alloys
The growth rates and chemical ordering of ferroelectric alloys are studied
with kinetic Monte Carlo (KMC) simulations using an electrostatic model with
long-range Coulomb interactions, as a function of temperature, chemical
composition, and substrate orientation. Crystal growth is characterized by
thermodynamic processes involving adsorption and evaporation, with
solid-on-solid restrictions and excluding diffusion. A KMC algorithm is
formulated to simulate this model efficiently in the presence of long-range
interactions. Simulations were carried out on Ba(Mg_{1/3}Nb_{2/3})O_3 (BMN)
type materials. Compared to the simple rocksalt ordered structures, ordered BMN
grows only at very low temperatures and only under finely tuned conditions. For
materials with tetravalent compositions, such as (1-x)Ba(Mg_{1/3}Nb_{2/3})O_3 +
xBaZrO_3 (BMN-BZ), the model does not incorporate tetravalent ions at
low-temperature, exhibiting a phase-separated ground state instead. At higher
temperatures, tetravalent ions can be incorporated, but the resulting crystals
show no chemical ordering in the absence of diffusive mechanisms.Comment: 13 pages, 16 postscript figures, submitted to Physics Review B
Journa
The effects of escitalopram on myocardial apoptosis and the expression of Bax and Bcl-2 during myocardial ischemia/reperfusion in a model of rats with depression
BackgroundMajor depressive disorder (MDD) is an independent risk factor for coronary heart disease (CHD), and influences the occurrence and prognosis of cardiovascular events. Although there is evidence that antidepressants may be cardioprotective after acute myocardial infarction (AMI) comorbid with MDD, the operative pathophysiological mechanisms remain unclear. Our aim was therefore to explore the molecular mechanisms of escitalopram on myocardial apoptosis and the expression of Bax and Bcl-2 in a rat model of depression during myocardial ischemia/reperfusion (I/R).MethodsRats were divided randomly into 3 groups (n = 8): D group (depression), DI/R group (depression with myocardial I/R) and escitalopram + DI/R group. The rats in all three groups underwent the same chronic mild stress and separation for 21 days, at the same time, in the escitalopram + DI/R group, rats were administered escitalopram by gavage (10 mg/kg/day). Ligation of the rat¿s left anterior descending branch was done in the myocardial I/R model. Following which behavioral tests were done. The size of the myocardial infarction was detected using 1.5% TTC dye. The Tunel method was used to detect apoptotic myocardial cells, and both the Rt-PCR method and immunohistochemical techniques were used to detect the expression of Bcl¿2 and Bax.ResultsCompared with the D and DI/R groups, rats in Escitalopram + DI/R group showed significantly increased movements and sucrose consumption (P < .01). Compared with the DI/R group, the myocardial infarct size in the escitalopram + DI/R group was significantly decreased (P < .01). Compared with the D group, there were significantly increased apoptotic myocardial cells in the DI/R and escitalopram + DI/R groups (P < .01); however compared with the DI/R group, apoptotic myocardial cell numbers in the escitalopram + DI/R group were significantly decreased (P < .01). Compared with the DI/R group, there was a down-regulated Bax:Bcl-2 ratio in the escitalopram + DI/R group (P < .01).ConclusionsThese results suggest that in patients with AMI comorbid with MDD, there is an increase in pro-apoptotic pathways that is reversed by escitalopram. This suggests that clinically escitalopram may have a direct cardioprotective after acute myocardial infarction
Microbial synthesis of poly(3-hydroxybutyrate-co-4- hydroxybutyrate) copolymer by Cupriavidus sp.USMAA2-4 through a two step cultivation process
A Gram negative bacterium, Cupriavidus sp. USMAA2-4 was isolated from a soil sample in Northern Peninsular of Malaysia and was able to synthesize polyhydroxyalkanoate containing 4-hydroxybutyrate unit when grown on g-butyrolactone as the sole carbon source. The polyester was purified from freezedried cells and analyzed by nuclear magnetic resonance (NMR) spectroscopy. 1H and 13C NMR results confirmed the presence of 3HB and 4HB monomers. The isolated strain has the ability to synthesize poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] in a two step cultivation process on a medium containing g-butyrolactone as the carbon source. A high fraction of 4HB monomer unit was obtained by manipulating the cell concentration, types of carbon sources and carbon source concentration in the cultivated medium. On the basis of the PHA composition, we suggest that carbon sources such as 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol and 1,12-dodecanediol resulted in a skewed PHA composition. On the other hand, the molar fraction of 4HB in P(3HB-co-4HB) was increased significantly from 25 – 51 mol % by the higher concentration of g-butyrolactone as the sole carbon source in the medium. The molecular weight and thermal properties of P(3HB-co-4HB) were revealed by gel permeation chromatography (GPC) and differential scanning calorimeter (DSC), respectively. We found that this bacterium is able to produce wide range copolymer with the numberaverage molecular weights (Mn) of copolymers ranging from 17 x 103 to 412 x 103 Dalton. Increase in the concentration of g-butyrolactone lowered the molecular weight of these copolymers. Higher concentration of g-butyrolactone also resulted in more branched polymer and consequently gave lower values for both the glass transition temperature (Tg) as well as melting temperature, Tm
EEG emotion recognition using reduced channel wavelet entropy and average wavelet coefficient features with normal Mutual Information method
© 2017 IEEE. Recognizing emotion from EEG signals is a complicated task that requires complex features and a substantial number of EEG channels. Simple algorithms to analyse the feature and reduce the EEG channel number will give an indispensable advantages. Therefore, this study explores a combination of wavelet entropy and average wavelet coefficient (WEAVE) as a potential EEG-emotion feature to classify valence and arousal emotions with the advantage of the ability to identify the occurrence of a pattern while at the same time identify the shape of a pattern in EEG emotion signal. The complexity of the feature was reduced using the Normalized Mutual Information (NMI) method to obtain a reduced number of channels. Classification with the WEAVE feature achieved 76.8% accuracy for valence and 74.3% for arousal emotion, respectively. The analysis with NMI shows that the WEAVE feature has linear characteristics and offers possibilities to reduce the EEG channels to a certain number. Further analysis also reveals that detection of valence emotion with reduced EEG channels has a different combination of EEG channels compared to arousal emotion
Some numerical methods and comparisons for solving mathematical model of surface decontamination by disinfectant solution
A mathematical model is considered to determine the effectiveness of disinfectant solution for surface decontamination. The decontamination process involved the diffusion of bacteria into disinfectant solution and the reaction of the disinfectant killing effect. The mathematical model is a reaction-diffusion type. Finite difference method and method of lines with fourth-order Runge-Kutta method are utilized to solve the model numerically. To obtain stable solutions, von Neumann stability analysis is employed to evaluate the stability of finite difference method. For stiff problem, Dormand-Prince method is applied as the estimated error of fourth-order Runge-Kutta method. MATLAB programming is selected for the computation of numerical solutions. From the results obtained, fourth-order Runge-Kutta method has a larger stability region and better accuracy of solutions compared to finite difference method when solving the disinfectant solution model. Moreover, a numerical simulation is carried out to investigate the effect of different thickness of disinfectant solution on bacteria reduction. Results show that thick disinfectant solution is able to reduce the dimensionless bacteria concentration more effectively
Active RIS Versus Passive RIS: Which Is Superior with the Same Power Budget?
This letter theoretically compares the active reconfigurable intelligent surface (RIS)-aided system with the passive RIS-aided system. For a fair comparison, we consider that these two systems have the same overall power budget that can be used at both the base station (BS) and the RIS. For active RIS, we first derive the optimal power splitting between the BS’s transmit signal power and RIS’s output signal power. We also analyze the impact of various system parameters on the optimal power splitting ratio. Then, we theoretically and numerically compare the performance between the active RIS and the passive RIS, which demonstrates that the active RIS would be superior if the power budget is not very small and the number of RIS elements is not very large
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