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31.
Recently, there have been a lot of research efforts on peer-to-peer (P2P) live streaming services. P2P systems can be easily deployed since a participating peer’s resources (i.e., upload link bandwidth) can be exploited to distribute contents. However, how to adapt to leaving peers and how to encourage peers to contribute resources voluntarily are still challenging issues. In this paper, we propose Climber, an adaptive P2P live streaming system with incentives for resilience. Climber is based on the hybrid structure of a tree and a mesh, so as to achieve self-improvement and adaptation to users’ dynamic joining and leaving. Moreover, Climber substantiates an incentive mechanism that provides better resilience for peers with more upload bandwidth allocated. Simulation results reveal that Climber significantly reduces the topology maintenance cost compared to SplitStream and NICE-PRM. Also, simulation and analytical results verify that Climber can bound the level of disruption by dynamically adapting to the user churning rate. 相似文献
32.
Effects of leukotriene D on the airways in asthma 总被引:2,自引:0,他引:2
M Griffin JW Weiss AG Leitch ER McFadden EJ Corey KF Austen JM Drazen 《Canadian Metallurgical Quarterly》1983,308(8):436-439
33.
A group of public health scientists from the United States and The Netherlands met at a Bicentennial Round Table Conference December 1-2, 1982, to discuss the latest developments in immunization against infectious diseases, focusing on pertussis, poliomyelitis, measles, and rubella. The major differences in immunization practices in the two countries are: (a) In The Netherlands, inactivated polio vaccine is used exclusively; in the United States, the oral polio vaccine is used. Polio-myelitis has virtually disappeared from both countries. (b) In The Netherlands, the pertussis component of DTP (diphtheria, tetanus, pertussis) is not given to children over the age of 1 year, whereas in the United States, it is given to children up to their seventh birthday. (c) Rubella vaccine is given only to girls at ages 11-12 years in The Netherlands, but to all children at ages 12-15 months in the United States. (d) Mumps vaccine is not administered to children in The Netherlands, but in the United States it is given routinely to children at 12-15 months (in combination with measles and rubella vaccine). The participants concluded that both the United States and The Netherlands have effective immunization programs that have significantly reduced the impact of these diseases. 相似文献
34.
The versatility and resolving power of countercurrent chromatography (CCC) has been demonstrated with a newly developed analytical high-speed planet centrifuge system. Interfacing countercurrent chromatography with mass spectrometry (MS) provides a new analytical methodology that integrates the advantages of countercurrent chromatography with the low detection limit and identification capability of mass spectrometry. In this paper the capability of thermospray CCC/MS is demonstrated in identifying and validating the bioactive and structurally known lignans from a crude extract of Schisandra rubriflora Rhed et Wils, a traditional Chinese herbal medicine for treatment of hepatitis. 相似文献
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PURPOSE: We determine the presence of an open bladder neck during video urodynamic studies and relate that finding to the presence of stress urinary incontinence. MATERIALS AND METHODS: Patients presenting with urinary incontinence, voiding dysfunction or pelvic floor prolapse underwent video urodynamics. With the patient upright and after 200 ml. contrast material had been instilled into the bladder the bladder neck was viewed to determine if it was open or closed. At that point the abdominal leak point pressure was measured. RESULTS: Of 102 women, average age 56.5 years (range 31 to 82), 13% had an open bladder neck and demonstrable stress incontinence on video urodynamics with an average abdominal leak point pressure of 45 cm. water (range 26 to 90). Of those with stress incontinence on urodynamics 23% had an open bladder neck. No continent patient had an open bladder neck. CONCLUSIONS: The presence of an open bladder neck with the bladder filled to 200 ml. correlates strongly with the presence of stress incontinence. 相似文献
37.
EJ Pappert CG Goetz FG Niederman R Raman S Leurgans 《Canadian Metallurgical Quarterly》1999,14(1):117-121
Middle ear effusion has been considered the most common cause of vestibular disturbance in children. However, there have been only a few studies on vestibular disturbance in children with otitis media with effusion. We studied the vestibular systems of 30 children with otitis media with effusion aged 8 to 13 years and compared the results with 15 age- and sex-matched controls. A questionnaire relating to vestibular disturbance was given to patients and their parents. Spontaneous nystagmus and positional nystagmus were recorded by electronystagmography as diagnostic tests of the vestibular system. Romberg's and past-pointing tests were performed on children with otitis media with effusion and controls. After vestibular tests were completed, myringotomy was performed, and a ventilation tube was inserted. The questionnaire and the vestibular tests were repeated after the operation and during the first month after surgery. Our study showed that there was a history of vestibular disturbance in 33% of children with otitis media with effusion. Electronystagmography and Romberg's test findings demonstrated that 33% of the children had vestibular dysfunction (p < 0.05). After myringotomy with ventilation tube insertion, vestibular test results returned to normal, and symptoms related to vestibular disturbance improved. These findings confirm the assumption that middle ear effusion may affect the vestibular system, which can be resolved after myringotomy with ventilation tube insertion. 相似文献
38.
Our study describes a newly designed stapedotomy prosthesis which consists of two components: (1) a platinum ribbon, and (2) a Teflon shaft. The first innovation is a flattened 'tab' on the posterior aspect of the platinum ribbon. The second innovation concerns the dual diameter cylinder-like shaft. Our prosthesis was implanted into 25 individuals, who underwent stapedotomy for stapes fixation, and the results are shown and discussed. Our innovations offer a proper and safe insertion of the prosthesis into the oval window associated with excellent manipulation and handling. At the same time, maximum visualization of the surgical field is achieved, while the stepped-down design of the shaft prevents the prosthesis protruding into the vestibule. 相似文献
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40.
B Pal EJ Nash B Oppenheim S Maxwell L McFarlane 《Canadian Metallurgical Quarterly》1997,36(10):1116-1117
An estimated third of rheumatologists send aspirated synovial fluid samples for culture routinely during the course of management of their patients irrespective of the underlying diagnosis. This is done apparently even when sepsis is not suspected. This audit of 507 synovial fluid culture requests revealed that positive bacterial growth was rare even when sepsis was queried on the request forms but none was positive in any of the routine samples. Our findings throw doubt on the value of routine synovial fluid culture. We recommend that such cultures are undertaken when infection is a possibility and in immuno-compromised patients. An average health district would save pounds 3000 per annum if such a policy was adopted, but across the National Health Service as a whole the total expenditure saved on this unnecessary investigation would be considerable. 相似文献