Signal analysis of total internal reflection fluorescent speckle microscopy (TIR-FSM) and wide-field epi-fluorescence FSM of the actin cytoskeleton and focal adhesions in living cells

Fluorescent speckle microscopy (FSM) uses low levels of fluorescent proteins to create fluorescent speckles on cytoskeletal polymers in high‐resolution fluorescence images of living cells. The dynamics of speckles over time encode subunit turnover and motion of the cytoskeletal polymers. We sought to improve on current FSM technology by first expanding it to study the dynamics of a non‐polymeric macromolecular assembly, using focal adhesions as a test case, and second, to exploit for FSM the high contrast afforded by total internal reflection fluorescence microscopy (TIR‐FM). Here, we first demonstrate that low levels of expression of a green fluorescent protein (GFP) conjugate of the focal adhesion protein, vinculin, results in clusters of fluorescent vinculin speckles on the ventral cell surface, which by immunofluorescence labelling of total vinculin correspond to sparse labelling of dense focal adhesion structures. This demonstrates that the FSM principle can be applied to study focal adhesions. We then use both GFP‐vinculin expression and microinjected fluorescently labelled purified actin to compare quantitatively the speckle signal in FSM images of focal adhesions and the actin cytoskeleton in living cells by TIR‐FM and wide‐field epifluorescence microscopy. We use quantitative FSM image analysis software to define two new parameters for analysing FSM signal features that we can extract automatically: speckle modulation and speckle detectability. Our analysis shows that TIR‐FSM affords major improvements in these parameters compared with wide‐field epifluorescence FSM. Finally, we find that use of a crippled eukaryotic expression promoter for driving low‐level GFP‐fusion protein expression is a useful tool for FSM imaging. When used in time‐lapse mode, TIR‐FSM of actin and GFP‐conjugated focal adhesion proteins will allow quantification of molecular dynamics within interesting macromolecular assemblies at the ventral surface of living cells.     

水库淤积初步平衡问题

水库淤积平衡问题对于确定淤积危害程度、可持续利用标准等都非常重要。本文通过分析大量已建、在建和规划水库淤积情况,对水库淤积初步平衡后淤积变化趋势与设计淤积标准等问题进行了讨论和商榷。研究表明,水库淤积初步平衡后,兴利库容淤积发展仍然很快,库尾河床与水位抬升仍在继续,并未最终稳定。水库淤积平衡应该更加注重兴利库容淤积情况和库尾河床与水位抬升趋势,仅仅关注总淤积量变化情况是不够的。从区域长远利益考虑,大江大河上的水库设计淤积年限还应大大加长。     

便携式全站仪在钻采井架钢结构安装中的应用

文章介绍了一种由便携机和全站仪组成的便携式全站仪 ,阐述了该全站仪在钻采井架钢结构施工安装过程中的测量工作 ,对测点产生的误差采用伪逆自由网平差方法进行处理 ,控制点的精度可达到± 5mm ,该全站仪具有快速、灵活、准确的特点 ,不仅提高了生产效率 ,而且达到了对资料的计算机化管理。     

试论双点后方交会简便公式

根据双点后方交会的图形特点和已知条件，列出了方程组，推导出了双点后方交会直接计算座标的简便公式，同时求出了精度计算公式，以供测量人员参考     

Distributed memory systems for simulating artificial neural networks

In executing tasks involving intelligent information processing, the human brain performs better than the digital computer. The human brain derives its power from a large number [O(10¹¹)] of neurons which are interconnected by a dense interconnection network [O(10⁵) connections per neuron]. Artificial neural network (ANN) paradigms adopt the structure of the brain to try to emulate the intelligent information processing methods of the brain. ANN techniques are being employed to solve problems in areas such as pattern recognition, and robotic processing. Simulation of ANNs involves implementation of large number of neurons and a massive interconnection network. In this paper, we discuss various simulation models of ANNs and their implementation on distributed memory systems. Our investigations reveal that communication-efficient networks of distributed memory systems perform better than other topologies in implementing ANNs.     

免棱镜全站仪检测建筑缺陷

本文介绍免棱镜全站仪及免棱镜测距原理,结合一个实例阐述工程应用——检测建筑缺陷。最后对其它应用和需要注意的问题作了简要说明。     

发酵香肠发酵过程中菌落总数数学模型的建立

用SAS9．0中的响应曲面试验设计，研究了盐浓度、水分活度、发酵温度、发酵时间和糖浓度等环境因子对发酵香肠发酵过程中细菌总数变化的影响，建立科学的数学模型，此数学模型能够表达发酵香肠发酵过程中细菌总数的变化趋势。用建立的数学模型对发酵过程中的微生物进行了预测，结果可靠。细菌总数与实验测定数据进行比较，平均误差范围是-10．20％～8．43％。此数学模型为发酵香肠发酵过程的控制，提高发酵肉制品的安全性，缩短生产周期提供了依据，也是微生物预报的重要基础。     

测量机器人GeoCOM接口技术的开发与应用

介绍了测量机器人(TCA2003全站仪)的一些强大功能,分析了其自带的GeoCOM(地理数据通信)接口技术的高级模式,在此基础上利用visual Basic 6.0语言和Access数据库,通过GeoCOM接口对测量机器人进行了二次开发,并应用于某水利枢纽加密控制网的自动观测.最后,通过平差计算得出了一些参考性结论.     

Business programmes and information systems methodologies

Abstract. An Information Systems Methodology is usually presented as a sequential set of tasks — planning, analysis, design and construction — resulting in a new business application. This classical 'forward-engineering' approach must be adapted to changing business needs — business process redesign, quality management, process and systems templates, advanced technologies, application packages, the reuse of existing information systems resources, and rapid delivery cycles. Using the most general concept of a Business Programme, this paper describes a methodological approach incorporating these modern themes that is qualitatively and quantitatively different from the classical model. It provides a framework for the integration of otherwise independent methodologies, and shows how an entire programme can be formulated, planned and executed. An example is provided, and the approach is justified.     

DETERMINATION OF TOTAL NITROGEN IN BARLEY AND MALT BY COMBUSTION METHOD—COLLABORATIVE TRIAL

A combustion method, relying on the Dumas principle, for the determination of total nitrogen in barley and malt, has been collaboratively tested by the Analysis Committee of the European Brewery Convention. Repeatability, r₉₅, and reproducibility, R₉₅, values were 0.063 and 0.116% of dry matter, respectively, for samples with nitrogen contents in the range 1.23 to 1.86% N of dry matter. There was no significant difference between these values for barley and malt. The Analysis Committee approved the adoption of the combustion method for inclusion in Analytica EBC as an alternative method.