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71.
Araabi BN Kehtarnavaz N McKinney T Hillman G Würsig B 《Annals of biomedical engineering》2000,28(10):1269-1279
This paper presents a syntactic/semantic string representation scheme as well as a string matching method as part of a computer-assisted system to identify dolphins from photographs of their dorsal fins. A low-level string representation is constructed from the curvature function of a dolphin's fin trailing edge, consisting of positive and negative curvature primitives. A high-level string representation is then built over the low-level string via merging appropriate groupings of primitives in order to have a less sensitive representation to curvature fluctuations or noise. A family of syntactic/semantic distance measures between two strings is introduced. A composite distance measure is then defined and used as a dissimilarity measure for database search, highlighting both the syntax (structure or sequence) and semantic (attribute or feature) differences. The syntax consists of an ordered sequence of significant protrusions and intrusions on the edge, while the semantics consist of seven attributes extracted from the edge and its curvature function. The matching results are reported for a database of 624 images corresponding to 164 individual dolphins. The identification results indicate that the developed string matching method performs better than the previous matching methods including dorsal ratio, curvature, and curve matching. The developed computer-assisted system can help marine mammalogists in their identification of dolphins, since it allows them to examine only a handful of candidate images instead of the currently used manual searching of the entire database. © 2000 Biomedical Engineering Society.
PAC00: 8780Tq, 4230Sy, 0705Pj 相似文献
72.
人嗜铬细胞瘤细胞的原代培养及鉴定 总被引:2,自引:2,他引:2
本研究拟建立人嗜铬细胞瘤细胞的原代培养方法。采用连续分次胶原酶消化法分离培养人嗜铬细胞瘤细胞,采用细胞培养液中儿茶酚胺水平检测、多聚甲醛诱发荧光及细胞嗜铬粒蛋白A(CgA)和神经元特异性烯醇化酶(NSE)的免疫组化染色等方法进行细胞性质和功能鉴定,并用噻唑兰(MTT)法观察原代培养的人嗜铬细胞瘤细胞的生长状况。结果表明,人嗜铬细胞瘤细胞在培养3~7天时生长较快,7天后细胞开始分化。经检测细胞培养液中的儿茶酚胺浓度、多聚甲醛诱发荧光等,证明该细胞有合成和分泌儿茶酚胺的功能。并且培养的细胞CgA和NSE免疫组化染色阳性。因此,本研究成功建立了人嗜铬细胞瘤细胞的原代培养方法,并鉴定其具有嗜铬细胞瘤的分泌和表达功能,国内尚未见报告。 相似文献
73.
74.
Peak Identification in Visual Evoked Potentials 总被引:2,自引:0,他引:2
Robert A. Hall Maurice Rappaport H. Kenneth Hopkins Ralph B. Griffin 《Psychophysiology》1973,10(1):52-60
Waveform patterns evoked by 4 intensities of flash in normal subjects were studied in relation to intersubject variability. Time-frequency distribution curves of all peaks occurring between 11 and 280 msec after flash onset and meeting minimal criteria were obtained from 46 males. These distributions closely corresponded to similar data reported by others for single intensity stimulation. An algorithm was developed which identified in 67 to 100% of instances a single “peak event’ within the time ranges of each of 6 peak distributions. Many peak events appeared and disappeared within the 4 intensity sets of individuals. Latencies were obtained for these peak events. Application of the algorithm to a replicate sample of 29 Ss, which included 8 females, indicated generalizability. Test-retest data on 15 Ss showed its reliability. The data suggest that methodology significantly contributes to the variability of peak identification among subjects. This may be reduced by employing multiple intensities of stimulation. 相似文献
75.
Automatic identification of landmarks in cephalometry is very important and useful for orthognathic surgery. A computerised
automatic cephalometric analysis system (CACAS), based on image processing, is presented. For an original X-ray image, median
filtering and histogram equalisation are used to improve image quality. The edge of an X-ray image is detected by a wavelet
transform and Canny filter. Seventeen landmarks in cephalometry are successfully identified by knowledge-based edge tracing
and changeable templates. Seventy-three measurements based on distances, angles and ratios between landmarks are computed
automatically. The reliability of the landmarks and the validity of the measurements are compared for automatic and manual
operation. The values of measurements obtained by CACAS are more precise and reliable: the mean error for linear measurements
is less than 0.9 mm; the mean error for angular measurements is less than 1.2°. The rate of validity is over 80%, even if
the image quality is poor. For an image with a high signal-to-noise ratio, the rate of validity of landmarking and measurements
using the CACAS system is over 90%. 相似文献
76.
Use of a multiplex PCR-based reverse line blot (mPCR/RLB) hybridisation assay for the rapid identification of bacterial pathogens. 总被引:1,自引:0,他引:1
Y Wang F Kong G L Gilbert M Brown W Gao S Yu Y Yang 《Clinical microbiology and infection》2008,14(2):155-160
The aim of this study was to develop a sensitive and reliable method for the molecular identification of pathogenic bacteria. A multiplex PCR-based reverse line blot (mPCR/RLB) hybridisation assay was developed and evaluated for the rapid identification of 24 systemic and respiratory bacterial pathogens in routine diagnosis. All species-specific probes designed for the RLB hybridised with amplified DNA only from the corresponding species. Sensitivity limits of the mPCR/RLB assay varied among the 24 target organisms from 0.05 pg to 0.5 ng of genomic DNA. The sensitivity of the assay was 2 x 10(2) CFU/mL for Streptococcus pneumoniae and 6 x 10(2) CFU/mL for Escherichia coli. The specificity of each probe was tested against 24 species. There were no cross-reactions among any of the 43 probes. The mPCR/RLB assay appeared to be a useful alternative tool for the molecular identification of common pathogens. 相似文献
77.
C. Potel M. Álvarez P. Álvarez I. Otero E. Fluiters 《Clinical microbiology and infection》2007,13(7):728-730
Antimicrobial resistance profiles, restriction fragment length polymorphism of the coagulase gene and repetitive element sequence-based PCR were used to classify 210 methicillin-resistant Staphylococcus aureus isolates recovered between 1997 and 2005 in two hospitals in Vigo, north-west Spain. Representative isolates belonging to the epidemic clones were analysed by spa typing and multilocus sequence typing, and the staphylococcal chromosomal cassette (SCC)mec type was determined for all isolates. The New York/Japan clone (t002-ST5-II) was detected in Spain for the first time. However, the New York/Japan and the Brazilian (t037-ST239-IIIA) clones were replaced by EMRSA-16 (t018-ST36-II), which at present is the predominant clone. 相似文献
78.
Puttemans ML Dryon L Massart DL 《Journal of pharmaceutical and biomedical analysis》1985,3(6):503-510
Synthetic dyes were extracted from syrups, oral suspensions, tablets, gelatin capsules, suppositories and granules by ion-pair formation with tri-n-octylamine (TnOA) and back-extracted with perchlorate ions. Identification was performed by TLC on cellulose layers and by reversed phase ion-pair HPLC. 相似文献
79.
Dr. Zsolt Szabó Henning Vosberg Charles A. Sondhaus Ludwig E. Feinendegen 《European journal of nuclear medicine and molecular imaging》1985,11(6-7):265-274
Examination of the input-output events in functioning organs by the use of the impulse-response function (IRF) for a radioactive tracer is gaining more and more ground in nuclear medicine. This study summarizes the development of deconvolution analysis, laying special stress on the model-free approach. System linearity and time invariance are discussed, and means of eliminating noise in IRFs originating from the input and organ-time-activity curves are outlined. Typical IRFs are illustrated by flow diagrams, time-domain curves, and their representation by Laplace transforms. The cases of nondiffusible and diffusible tracers as well as parenchymally extracted and transported substances are discussed. Methods for the derivation of models and for the calculation of physiologically important parameters from theIRFs are suggested.At present, a guest scientist at the Institute for Medicine, Nuclear Research Center Jülich, Jülich, Federal Republic of Germany 相似文献
80.
目的:鉴定并研究半夏AP2/ERF转录因子的功能,为推进半夏品种的遗传改良提供理论依据。方法:该文基于半夏三代转录组数据鉴定了半夏中AP2/ERF家族成员,并对其进行系统的生物信息学分析,同时利用实时荧光定量聚合酶链式反应(Real-time PCR)检测半夏AP2/ERF在不同组织及不同胁迫条件下的表达情况。结果:通过转录组数据共筛选出8个全长AP2/ERF转录因子家族成员,归为AP2、ERF和DREB 3个亚家族;半夏AP2/ERF的氨基酸数目为251~512个,等电点为5.29~11.72,不稳定指数为45.90~82.41,且主要定位于细胞核中;半夏AP2/ERF基因的结构域和Motifs相对保守。组织特异性表达模式分析显示,半夏AP2/ERF基因在不同组织部位中具有不同的表达模式,且主要在叶中表达。逆境胁迫应答分析表明,PtERF1主要响应NaCl的胁迫诱导;PtERF2和PtERF4在低温和聚乙二醇(PEG)胁迫下表达量均有较大幅度的上调;PtERF3同时响应低温和NaCl两种逆境的诱导;PtERF5同时响应高温、低温、NaCl、PEG胁迫诱导;PtERF7在高温胁迫下表达... 相似文献