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1.
Grandjouan  G.  Cour  P.  Gros  R. 《Plant Ecology》2000,147(2):147-163
The relation between pollen and climate is commonly computed by regressing the climatical factor. The disadvantage of this method is that it does not respect the ordinal and intermittent nature of field data. This paper overcomes the artefacts created by this problem by using a probabilist calibration, that quantifies the ecological linkage between a taxon T and a factor with a general parameter, the probability PROX for an abundance A being confined near the rank F of the factor. Confining simulates the effect of the factor upon the concentration of presences and ordering of abundances, and calibrates the climatical behaviour of a taxon with the set of PROX for all possible pairs (A,F). It summarizes a behaviour with the probable position of each abundance A in the range of the factor. Calibration was applied to 130 pollen taxa observed in a network of 80 standardized annual aeropollinic spectra. Spectra were mostly from France, the rest being from a transect stretching from Sweden to Algeria. Spectra were characterized by the values of 10 climatic factors, as well as the presence and abundance of 130 pollen taxa. The influence of geographical climate differences upon pollen content in the atmosphere was quantified by comparing the spectra. Pairs from different localities but the same year were compared. The reliability of indicator taxa was tested by estimating the climate in the 80 spectra using calibration. For all the taxa observed in a spectrum, the envelope of confinings generally followed an unimodal gradient, whose mode was the probable position of the spectrum. Reliability of the estimate was measured by its accuracy, being the agreement between estimates and measures; and by its stability, being the agreement between two estimates from the same climate according to two different flora (the two halves of a spectrum for instance). Average accuracy was 72%, and average stability 87%.  相似文献   

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【目的】评价VITEK2 Compact全自动微生物分析系统对牛乳中葡萄球菌属细菌鉴定效果。【方法】对从西宁、白银、西安三地乳样中分离的52株葡萄球菌通过VITEK2 Compact全自动微生物分析系统进行鉴定,并与革兰氏染色、触酶试验、血浆凝固酶试验以及16S r RNA基因序列分析结果进行比对;通过对凝固酶阴性葡萄球菌和凝固酶阳性葡萄球菌在不同麦氏浓度的鉴定,评价该系统的稳定性。【结果】VITEK2 Compact全自动微生物分析系统对葡萄球菌在\"属\"水平的鉴定结果符合率达96.15%,与血浆凝固酶结果对比,凝固酶阴性葡萄球菌属细菌鉴定结果符合率为92.86%,对凝固酶阳性葡萄球菌属细菌鉴定结果符合率为50%,但对具体种鉴定时,结果符合率仅为44.23%。在稳定性检测的试验中,鉴定符合率为100%,鉴定结果可靠性不随菌液浓度变化而变化。【结论】该系统可用于牛乳中葡萄球菌在\"属\"水平的鉴定。  相似文献   

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Background

Human core body temperature is kept quasi-constant regardless of varying thermal environments. It is well known that physiological thermoregulatory systems are under the control of central and peripheral sensory organs that are sensitive to thermal energy. If these systems wrongly respond to non-thermal stimuli, it may disturb human homeostasis.

Methods

Fifteen participants viewed video images evoking hot or cold impressions in a thermally constant environment. Cardiovascular indices were recorded during the experiments. Correlations between the ‘hot-cold’ impression scores and cardiovascular indices were calculated.

Results

The changes of heart rate, cardiac output, and total peripheral resistance were significantly correlated with the ‘hot-cold’ impression scores, and the tendencies were similar to those in actual thermal environments corresponding to the impressions.

Conclusions

The present results suggest that visual information without any thermal energy can affect physiological thermoregulatory systems at least superficially. To avoid such ‘virtual’ environments disturbing human homeostasis, further study and more attention are needed.  相似文献   

5.
目的:寻找先天性肛门直肠畸形患儿直肠末端组织中异常表达的蛋白质。方法:通过二维凝胶电泳分离先天性肛门直肠畸形患儿直肠末端组织及正常新生儿直肠末端组织,用Image Master2D Platium6.0软件比较电泳图谱中的异常蛋白质点。结果:筛选出19个表达差异的蛋白质点,其中有12个蛋白质点表达上调,7个蛋白质点表达下调,差异具有统计学意义。结论:先天性肛门直肠畸形可以导致血清中多种蛋白的异常表达。这些差异表达的蛋白可以为先天性肛门直肠畸形的进一步研究提供了依据。  相似文献   

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目的:研发三维测量软件,使用该软件对下颌非游离端单颗磨牙缺失后缺牙区相关解剖数据进行三维测量分析并建立数据库,为临床及科研提供参考依据。方法:选择50名确诊为下颌非游离端单颗磨牙缺失的成年患者,拍摄锥形束CT并运用3D-DMTC软件进行测量分析,测量缺牙区相关解剖数据。对各项结果用SPSS 21.0软件进行统计分析,并建立下颌单颗磨牙缺失后相关解剖数据库。结果:成功研发三维测量软件3D-DMTC。测得缺牙区牙槽嵴顶到下颌神经管的最近距离平均值为:15.84±2.10 mm;下颌神经管距离下颌骨颊侧壁最近距离平均值为:5.83±1.56 mm;下颌神经管距离下颌骨舌侧最近距离平均值为:3.78±1.19 mm;相邻两牙间最短距离平均值为:10.08±1.58 mm;剩余牙槽骨体积平均值为:2674.94±775.67 mm3。建立下颌单颗磨牙缺失后相关解剖数据库ADSML。结论:通过使用自主开发的测量软件测量得到相关数据并建立数据库,可辅助临床医生深入对患者颌骨的解剖情况的认识,并为临床治疗及相关科研提供参考。  相似文献   

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Aminoacyl-tRNA (aa-tRNA) is delivered to the ribosome in a ternary complex with elongation factor Tu (EF-Tu) and GTP. The stepwise movement of aa-tRNA from EF-Tu into the ribosomal A site entails a number of intermediates. The ribosome recognizes aa-tRNA through shape discrimination of the codon-anticodon duplex and regulates the rates of GTP hydrolysis by EF-Tu and aa-tRNA accommodation in the A site by an induced fit mechanism. Recent results of kinetic measurements, ribosome crystallography, single molecule FRET measurements, and cryo-electron microscopy suggest the mechanism of tRNA recognition and selection.  相似文献   

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Background

To promote the clinical application of next-generation sequencing, it is important to obtain accurate and consistent variants of target genomic regions at low cost. Ion Proton, the latest updated semiconductor-based sequencing instrument from Life Technologies, is designed to provide investigators with an inexpensive platform for human whole exome sequencing that achieves a rapid turnaround time. However, few studies have comprehensively compared and evaluated the accuracy of variant calling between Ion Proton and Illumina sequencing platforms such as HiSeq 2000, which is the most popular sequencing platform for the human genome. The Ion Proton sequencer combined with the Ion TargetSeq™ Exome Enrichment Kit together make up TargetSeq-Proton, whereas SureSelect-Hiseq is based on the Agilent SureSelect Human All Exon v4 Kit and the HiSeq 2000 sequencer.

Results

Here, we sequenced exonic DNA from four human blood samples using both TargetSeq-Proton and SureSelect-HiSeq. We then called variants in the exonic regions that overlapped between the two exome capture kits (33.6 Mb). The rates of shared variant loci called by two sequencing platforms were from 68.0 to 75.3 % in four samples, whereas the concordance of co-detected variant loci reached 99 %. Sanger sequencing validation revealed that the validated rate of concordant single nucleotide polymorphisms (SNPs) (91.5 %) was higher than the SNPs specific to TargetSeq-Proton (60.0 %) or specific to SureSelect-HiSeq (88.3 %). With regard to 1-bp small insertions and deletions (InDels), the Sanger sequencing validated rates of concordant variants (100.0 %) and SureSelect-HiSeq-specific (89.6 %) were higher than those of TargetSeq-Proton-specific (15.8 %).

Conclusions

In the sequencing of exonic regions, a combination of using of two sequencing strategies (SureSelect-HiSeq and TargetSeq-Proton) increased the variant calling specificity for concordant variant loci and the sensitivity for variant loci called by any one platform. However, for the sequencing of platform-specific variants, the accuracy of variant calling by HiSeq 2000 was higher than that of Ion Proton, specifically for the InDel detection. Moreover, the variant calling software also influences the detection of SNPs and, specifically, InDels in Ion Proton exome sequencing.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1796-6) contains supplementary material, which is available to authorized users.  相似文献   

9.
Two studies were performed to evaluate early pregnancy diagnosis by transrectal ultrasonography (TRUS), using a 7.5-MHz transducer in ewes. In the first study, the objectives were to determine the earliest date that a reliable pregnancy diagnosis could be made (percentage of ewes detected pregnant between days 15 and 20 after mating). In the second study, the objective was to confirm the findings of the first study using a randomized controlled trial. In both studies, the ewes were restrained in dorsal recumbency, using a special chute that maintained the pelvis at an angle of 30–35° lower than the head. In the first study, 30 Suffolk ewes were synchronized and maintained with 2 rams for 5 days. Each ewe was subjected to the first TRUS on day 15 after mating and daily thereafter until day 20 (estrus = day 0). Pregnancy was defined as the presence of an embryo or extra-embryonic membranes. The percentage of ewes detected pregnant at days 15, 16, 17, 18, 19 and 20 were 0% (0/30), 26.7% (8/30), 86% (24/30), 90% (27/30), 96.7% (29/30) and 100% (30/30), respectively (P < 0.001). In the second study, 390 TRUS examinations (TRUS-1) were performed on ewes from 10 to 50 days after mating in a breeding program (group mating, hand mating, cervical and intrauterine AI; breeding group; n = 270) or with vasectomized rams (vasectomized group; n = 120). The breeding date and the status of breeding were unknown to the operator. Thirty of these ewes were mated with vasectomized rams and used repetitively four times as the non-pregnant control group. All females had a subsequent TRUS (TRUS-2) between 7 and 30 days after the TRUS-1 examination. The second TRUS was used as the standard test against which the performance of the TRUS-1 was compared. The percentage of ewes correctly diagnosed at day 15 or less, days 16, 17, 18, and 19 in the breeding group were 0% (0/29), 31.3% (5/16), 40% (8/20), 70% (7/10), and 100% (14/14), respectively (P < 0.001). All the diagnoses of ewes more than 20 days following mating in the breeding group, were correctly predicted (n = 181), as well as all ewes from the vasectomized group (n = 120). It could thus be concluded that the earliest pregnancy diagnosis using a 7.5-MHz transducer by transrectal route based on the presence of positive signs of pregnancy is at day 16 and the maximum sensitivity and negative predictive value was reached at day 20 following breeding.  相似文献   

10.
The accuracy of digital Roentgen stereophotogrammetric analysis (RSA) was compared to the accuracy of a manually operated RSA system. For this purpose, we used radiographs of a phantom and radiographs of patients. The radiographs of the patients consisted of double examinations of 12 patients that had a tibial osteotomy and of double examinations of 12 patients that received a total hip prosthesis. First, the radiographs were measured manually with an accurate measurement table. Subsequently, the images were digitized by a film scanner at 150 DPI and 300 DPI resolutions and analyzed with the RSA-CMS software. In the phantom experiment, the manually operated system produced significantly better results than the digital system, although the maximum difference between the median values of the manually operated system and the digital system was as low as 0.013 mm for translations and 0.033° for rotations. In the radiographs of the patients, the manually operated system and the digital system produced equally accurate results: no significant differences in translations and rotations were found. We conclude that digital RSA is an accurate, fast, and user friendly alternative for manually operated RSA. Currently, digital RSA systems are being used in a growing number of clinical RSA-studies.  相似文献   

11.
Triangulation by radiotelemetry is a method commonly used to estimate locations of wildlife. Despite the importance of the accuracy of resulting location estimates, there has been little development and comparison of alternative methods for point-location estimation for 25 years. Most methods assume that signal transmissions as they are received are consistent, but signal heterogeneity and fluxing is common. Using data from a beacon study, we determined that a subjective ranking of confidence in the accuracy of a signal was correlated with absolute bearing error. Using this factor and the distance from a telemetry station to the error triangle incenter, we developed an algorithm to place a weighted point-location estimate in relative proximity to each error triangle leg. We have termed this the weighted-incenter method. Despite previous findings that the major confidence ellipse axis of Lenth’s maximum likelihood estimator (MLE) correlated best to linear distance error, our beacon test data indicated that total bearing angle difference was the best single predictor of linear error with an optimal total angle of about 100°. The new and intuitive weighted-incenter method offered some improvement over previous methods such as the MLE estimator, but only with suboptimal angle bearings that may be common in field studies. By using a MATLAB function to produce data for site-specific regression analyses, one can determine which method should produce the more accurate point-location estimate for each triangulation observation. Further significance of this study for field biologists is discussed.  相似文献   

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目的:探讨血栓弹力图评估胃癌患者围手术期凝血状态的临床应用价值。方法:选择2013年8月至2016年8月在我院进行治疗的胃癌患者80例作为观察组,同时选择同期在我院治疗的胃部良性疾病患者80例作为对照组。采用TEG评估两组患者的凝血功能,并且与常规凝血检查比较,分析两种凝血评估方法的准确率。结果:Ⅰ期胃癌患者的TEG各指标与对照组相比差异无统计学意义(P0.05),Ⅱ期胃癌患者的R值、K值、MA值以及CI值与对照组比较差异显著,具有统计学意义(P0.05),Ⅲ和Ⅳ胃癌患者的TEG各指标与对照组相比差异显著,具有统计学意义(P0.05);发生淋巴结转移的胃癌患者TEG各指标与对照组相比差异显著,具有统计学意义(P0.05),而没有发生淋巴结转移的患者与对照组相比差异无统计学意义(P0.05);进展期胃癌患者的TEG各指标与对照组比较差异显著,具有统计学意义(P0.05),而早期胃癌的TEG各指标与对照组差异不显著(P0.05);观察组患者治疗后,TEG检测血液发生低凝状态的检出率77.23%,常规检出率是46.15%;54例非出血患者中,TEG检出血液非凝状态的检出率为94.44%,常规检出率为77.78%。两种检测方法的检出率比较差异具有统计学意义(P0.05)。结论:胃癌患者的血液处于高凝状态,且高凝状态与病情发展的恶性程度呈正相关,TEG评估胃癌患者围术期的凝血状态较常规凝血检验更准确。  相似文献   

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目的:研究Buserelin原料药的性质在温度、湿度、光线等条件的影响下随时间变化的规律,为该原料药的生产、包装、储存、运输及有效期的制定提供依据。方法:根据中国药典2005版二部附录XIX C药物稳定性试验指导原则及化学药物稳定性研究技术指导原则进行强光照射、高温(60℃、40℃)、高湿(RH92.5%±5%、RH75%±5%)影响因素试验,加速试验(40℃±2℃、RH75%±5%;25℃±2℃、RH60%±10%);按Buserelin原料药标准规定的质量指标及相关的检验方法对产品在试验条件下的主要质量指标进行检测。结果:强光照射、高温、高湿等影响因素对Buserelin的稳定性有明显影响,故应密封、于干燥、阴凉处保存。在加速试验中,Buserelin原料药的各项质量指标发生了小的变化,但均在质量标准规定的范围内。结论:强光照射、高温、高湿等影响因素对Buserelin的稳定性有明显影响,应在阴凉干燥处避光密封保存和运输。加速试验结果证明:在此条件下,它的各项质量指标变化均在质量标准范围内,符合Buserelin原料药质量标准规定的要求;故将其保质期暂定为两年。  相似文献   

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本研究通过MTT法检测bFGF的活性,研究了不同温度下四种制剂中bFGF的稳定性。结果得到,bFGF在2.0mol/L NaCl,0.05mol/L PB溶液(pH7.2)中,-20℃下贮藏6个月活性没有明显的下降;bFGF水剂贮藏在4℃下,bFGF活性随贮藏时间延长逐步下降,单位活性bFGF用量由0.4ng/mL下降为0.9ng/mL,室温下bFGF的活性丧失快于4℃下贮藏,3个月后bFGF单位活性用量由0.4ng/mL下降为1.0ng/mL。而乳霜剂和胶束剂中的bFGF在两种温度下贮藏一个月后,均检测不到对细胞生长的刺激作用。说明低温有利于制剂中bFGF的稳定,乳霜剂和胶束剂中的bFGF稳定性不好。  相似文献   

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将批号4003、5002、5009的纯化疫苗室温(20℃)放置2周后,在不同间隔时间免疫家兔,分年度以ELISA检测免疫抗体及PRNT检测中和抗体,直至检测到第三年。结果证实,该型疫苗具有较好的室温稳定性。  相似文献   

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Animals of different sizes tend to move in a dynamically similar manner when travelling at speeds corresponding to equal values of a dimensionless parameter (DP) called the Froude number. Consequently, the Froude number has been widely used for defining equivalent speeds and predicting speeds of locomotion by extinct species and on other planets. However, experiments using simulated reduced gravity have demonstrated that equality of the Froude number does not guarantee dynamic similarity. This has cast doubt upon the usefulness of the Froude number in locomotion research. Here we use dimensional analysis of the planar spring-mass model, combined with Buckingham's Pi-Theorem, to demonstrate that four DPs must be equal for dynamic similarity in bouncing gaits such as trotting, hopping and bipedal running. This can be reduced to three DPs by applying the constraint of maintaining a constant average speed of locomotion. Sensitivity analysis indicates that all of these DPs are important for predicting dynamic similarity. We show that the reason humans do not run in a dynamically similar manner at equal Froude number in different levels of simulated reduced gravity is that dimensionless leg stiffness decreases as gravity increases. The reason that the Froude number can predict dynamic similarity in Earth gravity is that dimensionless leg stiffness and dimensionless vertical landing speed are both independent of size. In conclusion, although equal Froude number is not sufficient for dynamic similarity, it is a necessary condition. Therefore, to detect fundamental differences in locomotion, animals of different sizes should be compared at equal Froude number, so that they can be as close to dynamic similarity as possible. More generally, the concept of dynamic similarity provides a powerful framework within which similarities and differences in locomotion can be interpreted.  相似文献   

17.

Aim

To analyze intrafraction movement in patients undergoing frameless robotic radiosurgery and evaluate the influence of image acquisition frequency on global accuracy.

Background

Stereotactic radiosurgery requires high spatial accuracy in dose delivery. In conventional radiosurgery, a rigid frame is used to guarantee a correct target alignment and no subsequent movement. Frameless radiosurgery with thermoplastic mask for immobilization cannot completely eliminate intrafraction patient movement. In such cases, it is necessary to evaluate its influence on global treatment accuracy.

Materials and methods

We analyzed the intrafraction motion of the first 15 patients undergoing intracranial radiosurgery (39 fractions) with the CyberKnife VSI system at our institution. Patient position was measured at a 15–90-s interval and was used to estimate intrafraction patient movement.

Results

With our acquisition image protocol and immobilization device, the 99% displacement error was lower than 0.85 mm. The systematic movement components were lower than 0.05 mm and the random component was lower than 0.3 mm in the 3 translational axes. Clear linear time dependence was found in the random component.

Conclusions

Selection of the X-ray image acquisition time is necessary to meet the accuracy required for radiosurgery procedures with the CyberKnife VSI system. We verified that our image acquisition protocol met the 1-mm criterion.  相似文献   

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Inaccurate protein synthesis produces unstable -galactosidase, whose activity is rapidly lost at high temperature. Erythromycin, lincomycin, clindamycin, and celesticetin were shown to counteract the error-inducing effects of streptomycin on -galactosidase synthesized in the antibiotic-hypersensitive Escherichia coli strain DB-11 Met . Newly synthesized -galactosidase was more easily inactivated by high temperatures when synthesized by bacteria partially starved for arginine, threonine, or methionine. Simultaneous treatment with erythromycin or linocomycin yielded -galactosidase that was inactivated by high temperatures less easily than during starvation alone, an effect attributed to stimulation of ribosome editing. When synthesized in the presence of canavanine, -galactosidase was inactivated by high temperature more easily but this effect could not be reversed by erythromycin. The first arginine in -galactosidase occurs at residue 13, so the effect of erythromycin during arginine starvation is probably to stimulate dissociation of erroneous peptidyl-tRNAs of at least that length. Correction of errors induced by methionine starvation is probably due to stimulation of dissociation of erroneous peptidyl-tRNAs bearing peptides at least 92 residues in length. All the effects of erythromycin or the tested lincosamides on protein synthesis are probably the result of stimulating the dissociation from ribosomes of peptidyl-tRNAs that are erroneous or short.  相似文献   

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