A new adaptive Kalman filter-based subspace tracking algorithm and its application to DOA estimation

IEEE International Symposium on Circuits and Systems, Island of Kos, Greece, 21-24 May 2006This paper presents a new Kalman filter-based subspace tracking algorithm and its application to directions of arrival (DOA) estimation. An autoregressive (AR) process is used to describe the dynamics of the subspace and a new adaptive Kalman filter with variable measurements (KFYM) algorithm is developed to estimate the time-varying subspace recursively from the state-space model and the given observations. For stationary subspace, the proposed algorithm will switch to the conventional PAST to lower the computational complexity. Simulation results show that the adaptive subspace tracking method has a better performance than conventional algorithms in DOA estimation for a wide variety of experimental condition. © 2006 IEEE.published_or_final_versio

Sequence variation in TgROP7 gene among Toxoplasma gondii isolates from different hosts and geographical regions

Toxoplasma gondii can infect a wide range of hosts including mammals and birds, causing toxoplasmosis which is one of the most common parasitic zoonoses worldwide. The present study examined sequence variation in rhoptry 7 (ROP7) gene among different T. gondii isolates from different hosts and geographical localities. Phylogenetic analysis of the examined T. gondii isolates was conducted using the maximum likelihood (ML) method. Sequence analysis revealed that 60 nucleotide positions were variable in the ROP7 gene sequences among the 19 examined T. gondii isolates, corresponding to sequence variations of 0 to 1.7%, which occurred at the first, second and third codons. Phylogenetic analysis indicated that sequence variation in ROP7 gene was low among the examined T. gondii isolates from different hosts and geographical localities, and that the ROP7 sequence was not suitable as genetic marker for the differentiation of T. gondii isolates. The results of the present study suggest that ROP7 gene may be a suitable vaccine candidate.Key words: Sequence variation, rhoptry 7 (ROP7) gene, Toxoplasma gondii, toxoplasmosis, phylogenetic analysis

Liner Exchange Into A Well Fixed Acetabular Shell In Revision Total Hip Arthroplasty

OBJECTIVE To investigate clinical outcomes and complications of isolated polyethylene liner exchange for revision total hip arthroplasty. METHODS From April 1 995 to December 2007, 80 patients (93 hips) underwent revision total hip arthroplasty during which only polyethylene liner was exchanged with reservation of acetabular cup. There were 41 males and 39 females, aged from 27 to 82 years (average, 53.3 years). The duration from the primary THA to the revision surgery ranged from 0.3 to 18.4 years (average, 10.9 years). The reasons for liner exchange included: polyethylene wear with osteolysis (78 hips), polyethylene wear without osteolysis (5 hips), polyethylene wear with stem loosening (4 hips), recurrent dislocation (3 hips), infection (1 hip), periprosthetic fracture (1 hip) and liner dislodgement (1 hip). Forty-seven liners were fixed into the old cup using cement, and 46 were fixed with the original locking mechanism. Sixty cross-linked polyethylene liners and 33 conventional polyethylene liners were used. RESULTS All patients were followed up for 5 to 15 years (average, 7 years). The average Harris hip score improved from preoperative 86.0±16.9 to 89.4±11.6 at final follow-up. Complications included dislocation (10 hips), infection (2 hips), periprosthetic fracture (1 hip) and liner dislodgement (1 hip). Ten hips underwent rerevision due to different reasons: cup exchange (5 hips), conventional polyethylene wear (2 hips), infection (2 hips) and liner dislodgement (1 hip). Using component loosening as the end point, the 10-year survival rate was 100% in the cement fixation group and 84.8% in the original locking group. Using rerevision as the end point, the 10-year survival rate was 90.4% in the cement fixation group and 65.0% in the original locking group. CONCLUSION Liner exchange either with cement or original locking mechanism is a safe and successful method. Highly cross-linked polyethylene has a higher wear resistance, which can reduce incidence of osteolysis and improve survival rate of prosthesis.目的探討保留髖臼杯更換聚乙烯襯墊在全髖關節翻修術中的作用.方法1995年4月至2007年12月,80例(93髖)接受保留髖臼杯更換聚乙烯襯墊手術.男41例,女39例;年齡2782歲,平均53.3歲.初次置換與更換襯墊手術間隔0.318.4年,平均10.9年.翻修原因:聚乙烯磨損及骨溶解78髖,聚乙烯接近完全磨損但無骨溶解5髖,聚乙烯磨損及股骨柄假體鬆動4髖,復發性關節脫位3髖,感染1髖,假體周圍骨折1髖,襯墊脫位1髖.翻修襯墊採用高交聯聚乙烯60髖、普通聚乙烯33髖,以骨水泥固定47髖、原鎖定機制固定46髖.結果隨訪515年,平均7年.術前Harris髖關節評分(86.0±16.9)分,終末隨訪時(89.4±11.6)分.並發症包括脫位10髖,感染2髖,假體周圍骨折1髖,襯墊脫落1髖.10髖再次翻修:髖臼杯翻修5髖,普通聚乙烯磨損2髖,感染2髖,襯墊脫落1髖.普通聚乙烯組新發骨溶解12髖.以假體鬆動為終點,十年生存率骨水泥固定組100%、原鎖定機制固定組84.8 %;以再次翻修為終點,十年生存率分別為90.4%和65.0%.結論以骨水泥或原鎖定機制固定翻修襯墊均安全有效.高交聯聚乙烯耐磨性較好,能降低骨溶解風險,假體存活率更高

Study on electrochemical properties of FeS2 in room temperature molten salt

In this paper, FeS2 electrodes have been prepared by using reactive codeposition methods. The electrochemical performances of FeS2 were studied in LiCl buffer Lewis neutral 1-methyl-3-ethylimidazolium chloride (MeEtImCl)/AlCl3 (room temperature molten salt) melts. The results show that FeS2 electrodes possess reversible Li ion intercalation and deintercalation behavior in the first step two electron processes.published_or_final_versio

Phylogeny of Prokaryotes and Chloroplasts Revealed by a Simple Composition Approach on All Protein Sequences from Complete Genomes Without Sequence Alignment

The complete genomes of living organisms have provided much information on their phylogenetic relationships. Similarly, the complete genomes of chloroplasts have helped to resolve the evolution of this organelle in photosynthetic eukaryotes. In this paper we propose an alternative method of phylogenetic analysis using compositional statistics for all protein sequences from complete genomes. This new method is conceptually simpler than and computationally as fast as the one proposed by Qi et al. (2004b) and Chu et al. (2004). The same data sets used in Qi et al. (2004b) and Chu et al. (2004) are analyzed using the new method. Our distance-based phylogenic tree of the 109 prokaryotes and eukaryotes agrees with the biologists tree of life based on 16S rRNA comparison in a predominant majority of basic branching and most lower taxa. Our phylogenetic analysis also shows that the chloroplast genomes are separated to two major clades corresponding to chlorophytes s.l. and rhodophytes s.l. The interrelationships among the chloroplasts are largely in agreement with the current understanding on chloroplast evolution

Genetic diversity among Toxoplasma gondii isolates from different hosts and geographical locations revealed by analysis of ROP13 gene sequences

Toxoplasma gondii can infect almost all the warm-blooded animals and human beings, causing serious public health problems and economic losses worldwide. Rhoptry protein 13 (ROP13) plays some roles in the invasion process of T. gondii. In this study, sequence variation in ROP13 gene among 14 T. gondii isolates from different geographical locations and hosts was examined. The ROP13 gene was amplified from individual isolates and sequenced. Results show that the length of the ROP13 sequences was 1203 bp. In total, there were 44 variable nucleotide positions in the ROP13 sequences, and sequence variations were 0.1 to 2.0% among the 14 examined T. gondii isolates, representing higher rate in transversion than in transition. Intra-specific nucleotide variations were mainly at the second codon positions. Phylogenetic analysis of the 14 examined T. gondii isolates indicate that the ROP13 sequence was not a suitable genetic marker to differentiate T. gondii isolates of different genotypes from different hosts and geographical regions. Low variation in ROP13 gene sequence may suggest that ROP13 gene could represent a good vaccine candidate against toxoplasmosis.Key words: Toxoplasma gondii, toxoplasmosis, rhpotry protein 13 (ROP13), sequence variation, phylogenetic analysis

Photoluminescence study on coarsening of self-assembled InAlAs quantum dots on GaAs (001)

Red-emission at similar to 640 nm from self-assembled In0.55Al0.45As/Al0.5Ga0.5As quantum dots grown on GaAs substrate by molecular beam epitaxy (MBE) has been demonstrated. We obtained a double-peak structure of photoluminescence (PL) spectra from quantum dots. An atomic force micrograph (AFM) image for uncapped sample also shows a bimodal distribution of dot sizes. From the temperature and excitation intensity dependence of PL spectra, we found that the double-peak structure of PL spectra from quantum dots was strongly correlated to the two predominant quantum dot families. Taking into account quantum-size effect on the peak energy, we propose that the high (low) energy peak results from a smaller (larger) dot family, and this result is identical with the statistical distribution of dot lateral size from the AFM image

Microwave-induced plasma boosted microsecond-pulse glow discharge optical emission spectrometry

A microsecond-pulse (mu s-pulse) glow discharge (GD) source boosted by a microwave-induced plasma (MIP) has been developed and studied for optical emission spectrometry (OES), The excitation processes of the tandem GD source were investigated, The analytical characteristics of the GD-OES source in the presence and absence of the MIP were compared, including the operating parameters, signal-to-background ratios (S/B) and relative standard deviation (RSD), The results show that under a relatively low discharge pressure (<180 Pa), the mu s-pulse GD can couple fairly well with the MIP and emit intense analytical lines, When the GD source is operated under a pressure higher than 200 Pa, tao emission peaks appear, independent in time, for a given resonance atomic line, because sample atoms are independently structurally excited, first by the mu s-pulse GD and then by the MIP. The time interval between the tao peaks for Zn I 213.8 nm is longer than that for Cu I 324.7 nm, which is believed to be due to the faster diffusing velocity of copper atoms, When the mu s-pulse GD lamp is operated under a gas pressure higher than 220 Pa, the ion population is so high that Cu II ionic line at 224.7 nm 'becomes' two peaks because of a possible self-absorption. The results show that the supplementary nse of an MIP can eliminate the self-absorption of ionic and atomic lines, When the mu s-pulse GD source is coupled with the MTP, S/Bs are improved by a factor of more than one order of magnitude for several analytical lines. A short-term RSD of 0.2% is achieved for the 'mu s-pulse GD+MIP' configuration compared with that of 1.0% for 'mu s-pulse GD only' mode. The experimental results show that the MIP boosted mu s-pulse GD is a promising technique for solid sample and surface analysis