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1.
Gao  Hongyan  Huang  Rong  Liu  Jun  Gao  Zhimin  Zhao  Hansheng  Li  Xueping 《Journal of Plant Growth Regulation》2019,38(4):1616-1616
Journal of Plant Growth Regulation - The original version of this article unfortunately contained an error in Funding section. The authors would like to correct the error with this erratum.  相似文献   

2.
The error of measuring the section areas and perimeters of microvessels was estimated, which is due to a deviation of the section plane from the direction perpendicular to the longitudinal axis of microvessels. The estimates of the microvessel nonperpendicular sectioning error correspond to the case of three-dimensional isotropic distribution of microvessels without their own eccentricity. Only those microvessel profiles are selected for morphometry that meet the condition theta min < or = b/c < or = 1.00, where b is the minor and c is the major radii of microvessel profile on a section, and theta min is the tolerance for profile nonperpendicularity.  相似文献   

3.
Xu  Yuanchao  Jiao  Kailin  Zhong  Huichang  Wu  Shengshan  Ho  Shih-Hsin  Zeng  Xianhai  Li  Jinglong  Tang  Xing  Sun  Yong  Lin  Lu 《Bioprocess and biosystems engineering》2020,43(2):357-357
Bioprocess and Biosystems Engineering - The original version of the article unfortunately contained an error in Microalgae strain and culture medium section. Below is the corrected version.  相似文献   

4.
International Journal of Peptide Research and Therapeutics - The original version of this article unfortunately contained an error in the co-author name and also the Acknowledgement section was not...  相似文献   

5.
Unfortunately, upon publication of this article [1] it was noticed there was an error within the Discussion section. During proofing a request to edit the following paragraph was missed:  相似文献   

6.
7.
Synopsis At each of 11 localities a section of stream was closed off with nets and an electrofisher used to estimate the abundance of fishes in the section. Each section was fished from 5–7 times with each fishing equalling one unit of effort. Using the catch-effort methods of Leslie, DeLury and Ricker, separate estimates were made for each species. In several cases species were split into size groups and estimates made for each group. The fish remaining in each section after the fishings were collected using rotenone. Thus the estimates could be compared to the actual number of fish present. Estimates were considered to be either good, if the regressions used in the above methods were statistically significant or bad if they were not significant. Lower limits for the number of fish and mean weight of a fish for good estimates were identified.The Leslie and Ricker estimates, which did not differ significantly, were least in error. They tended to underestimate (–21.6% on the average for the Leslie method). Direct estimates of biomass did not differ significantly from those made using the estimates for numbers and the mean weight of fish caught. The interrelationships among variables such as mean weight, numbers, catchability, density, biomass, number of catches used, proportion of fish taken during the estimate, number of fish in the last catch and their relationships with the error of the estimates were examined using correlation and principal components analysis. Error was most closely related to the proportion of fish collected. The effects of other variables such as mean weight affected error through catchability and subsequently the proportion of fishes caught. It was not possible to predict a significant proportion of the error using variables which could be measured without a complete collection. The effects of locality, electrofisher, and species on error were examined. Each accounted for a significant proportion of the variability in error but primarily by affecting the proportion of fish caught.These results suggest that the most appropriate way of decreasing error would be to increase the total effort and consequently the proportion of fish collected. This would be best done by increasing the number of fishings used in the estimate.Catchability tended to decrease in successive fishings. The observed trends in changing catchability accounted for most of the error. Size-selectivity, which was evident as a change in mean weight in successive catches, was not significantly associated with changing catchability.  相似文献   

8.
The area of the section of presynaptic dense projections of the active zone of axondendritic synapses of the rat's cortex was measured using a television complex. Tissue specimens were contrasted with phosphotungstic acid. Morphometry was carried out in the regime of error correction in measurement, the errors arising in scanning process of image. The area of the section of mitochondria, lysosome, nucleoli, channels and tanks of the endoplasmic reticulum may be measured by the method suggested. Quantitative data, obtained by the morphometry of the synapse ultrastructure, may serve a basis for understanding the mechanism by which synapses are involved in information processes of the central nervous system.  相似文献   

9.
We examined the measurement error in inhaled and exhaled aerosol concentration resulting from the bolus delivery system when small volumes of monodisperse aerosols are inspired to different lung depths. A laser photometer that illuminated approximately 75% of the breathing path cross section recorded low inhaled bolus half-widths (42 ml) and negative deposition values for shallow bolus inhalation when the inhalation path of a 60-ml aerosol was straight and unobstructed. We attributed these results to incomplete mixing of the inhaled aerosol bolus over the breathing path cross section, on the basis of simultaneous recordings of the photometer with a particle-counter sampling from either the center or the edge of the breathing path. Inserting a 90 degrees bend into the inhaled bolus path increased the photometer measurement of inhaled bolus half-width to 57 ml and yielded positive deposition values. Dispersion, which is predominantly affected by exhaled bolus half-width, was not significantly altered by the 90 degrees bend. We conclude that aerosol bolus-delivery systems should ensure adequate mixing of the inhaled bolus to avoid error in measurement of bolus deposition.  相似文献   

10.
Response to     
We are responding to a Letter to the Editor addressing the Method section of our paper “Different measures of ‘genome-wide’ DNA methylation exhibit unique properties in placental and somatic tissues.” The letter raised concerns that the protocol for Epigentek’s MethylFlash kit was followed incorrectly based on the wording of an online publication of our article. We admittedly made an error in the language used to describe the MethylFlash protocol in our initial submission and thus this was corrected as soon as it was brought to our attention. However, the error was only in language and not procedure. We are confident that the protocol was followed as stated in the insert provided with the MethylFlashTM Methylated DNA Quantification kit (Colorimetric).  相似文献   

11.
湿地松林叶面积指数测算   总被引:5,自引:6,他引:5  
李轩然  刘琪璟  蔡哲  马泽清 《生态学报》2006,26(12):4099-4105
对湿地松(Pinus elliotii)当年生和多年生两针一束、三针一束叶片的长度、宽度、厚度和重量分别进行量测,据此探讨不同类型叶片的叶形和比叶面积差异,并结合样地调查数据对中科院千烟洲试验站湿地松人工林的叶面积指数进行计算。结果表明:湿地松三针一束叶片合拢后横切面基本呈圆形,当年生叶和多年生叶的平均直径分别为1.688mm和1.706mm;两针一束叶片合拢后从统计学上讲横切面不是圆形,而是椭圆形,叶片厚度方向直径大于宽度方向(当年生叶厚度和宽度方向直径分别为1.580ram和1.422mm,多年生叶分别为1.568mm和1.410mm),但如果把厚度和宽度方向直径的平均值近似成圆柱体直径计算时误差在3%以内;如果只用厚度或宽度方向直径代表平均直径计算结果会有2%。10%的误差;当年生叶和多年生叶、两针一束叶和三针一束叶之间比叶面积差别很大,计算的三种比叶面积(投影比叶面积、圆柱面比叶面积和比表面积)中,当年生叶的比叶面积明显大于多年生叶,三针一束叶片的投影比叶面积和比表面积都大于两针一束叶片,但圆柱面比叶面积恰好相反。湿地松林的叶面积指数若按投影叶面积算为3.61,按圆柱面的外表面算为5.12,按总表面积的一半算为4.52,比利用冠层分析仪测量的结果略大。  相似文献   

12.
The author has analytically expressed the relationship between the inaccessible for measurement total length of non-randomly oriented stretched objects and the sum of lengths of their projections on the longitudinal axis of the preparation (or another line). The sum of their projection lengths can be measured by means of a square-net ocular. The specific length of objects on a histological section is proportional to the number of their intersections with the transversal lines of the net and the value of its division and inversly proportional to the cosine of the average meaning of angles between the longitudinal axis of the preparation and the objects under study. Verification of the validity of the formula deduced was carried on in the histological section model prepared by the author. The proposed method ensures determination of the specific length of stretched histological preparations with a no more than 3% error.  相似文献   

13.
针对光声图像重建过程中存在的原始光声信号信噪比差、重建图像对比度低、分辨率不足等问题,提出了基于Renyi熵的光声图像重建滤波算法.该算法首先根据原始光声信号的Renyi熵分布情况,确定分割阈值,并滤除杂波信号;再利用滤波后的光声数据进行延时叠加光声图像重建.利用该滤波算法分别处理铅笔芯横截面(零维)、头发丝(一维)以及小鼠大脑皮层血管(二维)等不同维度样本的光声信号,实验结果表明:相比Renyi熵处理之前,重建图像对比度平均增强了32.45%,分辨率平均提高了30.78%,信噪比提高了47.66%,均方误差降低了35.01%;相比典型的滤波处理算法(模极大值法和阈值去噪法),本研究中图像的对比度、分辨率和信噪比分别提高了25.94%/10.60%、27.90%/19.48%、35.21%/10.60%,均方误差减小了28.57%/16.66%.因此,选择利用Renyi熵滤波算法处理光声信号,从而使光声图像重建质量得到大幅改善.  相似文献   

14.
The purpose of this paper is to justify an asymptotic method developed for the study of peristaltic transport in a tube of arbitrary cross section. Within the framework of long wave approximation, the three-dimensional nonlinear Navier-Stokes equations are reduced to a sequence of two-dimensional linear boundary value problems of Laplace and biharmonic operators. It is shown that, if a Reynolds number is less than some constant, the solution of the approximate equations is indeed an asymptotic approximation to the exact solution of the problem as the ratio of the maximum radius of the tube to the wave length of the peristaltic motion of the wall tends to zero, and the error estimates are expressed inL 2 norms. Furthermore, under the same condition the exact solution is shown to be unique and stable under arbitrary perturbation of spatially periodic disturbance. Application of the stability condition to peristaltic transport in a tube of circular cross section is given.  相似文献   

15.
内循环颗粒污泥床硝化反应器流动模型研究   总被引:3,自引:0,他引:3  
卢刚  郑平 《生物工程学报》2003,19(6):754-757
采用脉冲刺激响应技术,对稳态内循环颗粒污泥床硝化反应器进行了示踪试验。根据试验结果,分别运用轴向扩散模型和多釜全混流反应器串联模型,对反应器沉淀区和循环区的流态进行了分析和判断。结果表明,反应器沉淀区的分散数D/uL为0.00148,该区域的流态接近于平推流反应器(PFR);反应器循环区的串联级数为1.021,该区域的流态接近于全混流反应器(CSTR)。稳态时,反应器的理论水力停留时间为360min,实际水力停留时间为341.2min,反应器中死区所占的体积百分比为5.22%,其中生物体死区为0.75%,水力死区为4.47%,表明反应器结构性能良好。根据试验和分析结果,建立了内循环颗粒污泥床硝化反应器的流动模型,即全混流和平推流的串联组合模型。由流动模型所得的理论停留时间分布曲线与由试验所得的实际停留时间分布曲线吻合良好,两者的平均相对误差为8.56%,表明所建模型具有较高的准确性。  相似文献   

16.
Estimation of age at death from second metacarpals.   总被引:2,自引:0,他引:2  
This study examined the estimation of age at death from the second metacarpal in 227 individuals aged 30-98 years. Variables ascertained from each bone were: cortical thickness and microdensitometric cortical bone density measured on radiographs of the bone and total osteon count and density recorded on microradiographs of the complete cross section at its midshaft. Based on the latter two variables, two age groups were formed; a middle age group representing those individuals aged 30-65 years, and an older group aged 65+. Stepwise regression analysis of the four variables produced a series of regression equations for age estimation for the middle, old and combined age groups for each sex and sexes combined. Sex-specific equations provided better results than nonspecific ones, especially in females. Total osteon density and combined cortical thickness were found to be the most useful estimators in the middle and the old age group, respectively. The standard error of estimate was 6.71 and 6.90 years in each age group for the sexes combined. In the combined age group, age could be estimated accurately from total osteon count, cortical thickness and MD cortical bone density with the standard error of estimate of 11.10 years. The relative error of estimate ranged within +/- 30% in almost all individuals aged above 60 years.  相似文献   

17.
We are responding to a Letter to the Editor addressing the Method section of our paper “Different measures of ‘genome-wide’ DNA methylation exhibit unique properties in placental and somatic tissues.” The letter raised concerns that the protocol for Epigentek’s MethylFlash kit was followed incorrectly based on the wording of an online publication of our article. We admittedly made an error in the language used to describe the MethylFlash protocol in our initial submission and thus this was corrected as soon as it was brought to our attention. However, the error was only in language and not procedure. We are confident that the protocol was followed as stated in the insert provided with the MethylFlashTM Methylated DNA Quantification kit (Colorimetric).We are responding to a Letter to the Editor addressing the Method section of our paper “Different measures of ‘genome-wide’ DNA methylation exhibit unique properties in placental and somatic tissues” (Price ME, Cotton AM, PeÒaherrera MS, McFadden DE, Kobor MS, Robinson WP. Different measures of “genome-wide” DNA methylation exhibit unique properties in placental and somatic tissues. Epigenetics 2012; 7: 652–63; PMID: 22531475; 10.4161/epi.20221). The letter raised concerns that the protocol for Epigentek’s MethylFlash kit was followed incorrectly based on the wording of an online publication of our article. We admittedly made an error in the language used to describe the MethylFlash protocol in our initial submission and thus this was corrected as soon as it was brought to our attention. However, the error was only in language and not procedure. We are confident that the protocol was followed as stated in the insert provided with the MethylFlashTM Methylated DNA Quantification kit (Colorimetric).  相似文献   

18.
Summary Dictyosome ultrastructure changes during the cell cycle in onion root meristematic cells. Changes were mainly related to cisternae and intercisternal spaces morphology. Taking each dictyosome to be composed of three different regions (CIS, medial, and TRANS), several quantitative changes were detected in some of the compartments. Many of the planimetric parameters evaluated showed higher values in medical cisternae, while CIS and TRANS remained nearly constant. We have also found an increased activity of dictyosomes, as indicated by increase in the volume fraction of vesicular attached structures. This reaches maximum values at ana-telophase in coincidence with the onset and progression of cytokinesis.Abbreviations A anaphase - Ac mean area occupied by cisternae per stack section - C CIS - CCS cell cycle stage - DA mean total dictyosome area - ISA mean area occupied by intercisternal spaces per stack section - M metaphase - N mean number of cisternae per stack - P prophase - S.E. standard error - T telophase - T TRANS - Vv volume density  相似文献   

19.
The estimation of numbers of nerve fibers in cross sections of peripheral nerves containing both fine and large fiber components can be accomplished by using an ocular grid and selectively counting a known area. With the use of a projecting apparatus and planimeter, the total cross section area is determined.

The following proportion expresses the principle involved:

total number of fibers in the nerve area of ass section of entire nerve number counted in the sample area area of sample

I f the planimeter calibration and the magnification of the tracing remain the same, a constant factor may be used for successive estimates. This factor is equal to the value of the planimeter reading of 1.000 divided by the area of the grid times the magnification squared. The final calculations are made by multiplying the number of fibers counted times the planimeter reading times the constant and dividing by the number of grid squares counted.

Counts of some nerves, using high magnification in enumerating the sample areas, can be finished in less than an hour after the preparation of slides. In comparing numbers obtained by complete counts with estimated numbers, the error was determined to be approximately ± 5%  相似文献   

20.
Ring width of a given year can be highly variable throughout the cross section of a stem. This is especially true for roots. Therefore, the entire circumference of tree rings is often needed for studies focusing on specific reactions of individual trees on certain environmental conditions. Also, ring reconstructions are of interest for biomass calculations estimated by the cross-sectional area. The aim of the study is thus to reconstruct tree rings of cross sections within a 3D root-surface model, which will be the basis for an upcoming 3D root-development model. A FARO ScanArm was used for the acquisition of the 3D root structure (Technologies Inc., 2010). Afterwards ring-width data was measured along 4 radii per cross section and the resulting ring boundaries were integrated into the 3D root model. A weighted interpolation algorithm was used to reconstruct entire ring-width profiles of the cross sections. The algorithm considered the ring-width variations of the adjacent radii as well as the outer shape of the cross section. Hence, the intention was to estimate ring width around the root circumference using ring widths measured along 4 radii and the surface dimensions of roots. Interpolated ring-width data was compared to the measured tree-ring data as a control for the developed interpolation algorithm. Comparisons between modelled and empirical values showed a mean absolute error of about 0.06 mm deviation, and with a few exceptions the growth patterns could be accurately simulated. This has permitted additional radii measurements to be replaced by model interpolations.  相似文献   

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