Procion brown: an intracellular dye for light and electron microscopy

Procion browvn has been used to inject lamprey giant interneutros. The dye is opaque to both light and electrons, and imparts a pink color to the neuron in situ during iontophoresis. It has the advantage over cobaltolus chloride that postinjection treatment with ammonium sulfide is eliminated and the integrity of the surrounding neuropil is ensured.     

Branching of central neurons: intracellular cobalt injection for light and electron microscopy

Cobalt chloride can be injected into an identified nerve cell body in an insect ganglion and reacted with ammonium sulfide to stain the soma and its branches with a black precipitate. The stained cell body and its branches throughout the neuropil are visible in both the light and electron microscope. In whole mount preparations, the resolution of neurites within the neuropil is of a quality that permits the comparison of branching patterns between cells and during various functional states.     

Microaggregations of oceanic plankton observed by towed video microscopy

Oceanic plankton have been hypothesized to occur in micropatches (<10 meters) that can have a large impact on marine ecosystem dynamics. Towed video microscopy was used to unobtrusively determine distributions of oceanic plankton over a continuum of scales from microns to hundreds of meters. Distinct, taxa-specific aggregations measuring less than 20 centimeters were found for copepods but not for nonmotile (cyanobacterial colonies) or asexual (doliolid phorozooids) forms, which suggests that these small patches are related to mating. Significant patchiness was also found on larger scales and was correlated among taxa, indicating physical control. These video observations provide new insights into basic plankton ecology by allowing quantitative assessment of individual plankton in their natural, undisturbed state.     

基于粒子群算法的LED植物光源最优光照区域确定

针对LED植物光源光照分布的不均匀问题,首先建立了红、蓝光LED组合分布的植物光源阵列光照度分布及光照均匀度模型。综合考虑照明区域的光照均匀性及面积大小2个因素,构建出光照区域优劣评价函数,以矩形结构的LED植物光源为例,应用粒子群算法确定出最优的光照区域。在光照均匀性与面积2个因素的影响比重为7∶3条件下,得到了最优区域是光照平面中央位置面积为21.5462cm×18.1cm的矩形区域,红、蓝光均匀度均达到了0.862 2。与采用传统方法模拟的光照度分布情况对比,结果表明:应用粒子群算法确定LED植物光源的最优光照区域的方法是有效可行的,并且能够自动实现寻优功能。该方法可为LED光源下植物最优培养区域的自动跟踪提供重要的技术支撑。     

光诱渔业中光强分布的理论研究及其应用

集鱼灯合理配置是光诱渔业中重要的研究课题之一,需要从理论和实践两个方面加以分析和研究,以探讨灯光配置包括种类、布局等是否合理。根据光学理论和集鱼灯的发光特点,使用面光源积分计算方法建立了集鱼灯光强计算的公式,该方法比以往的线光源以及点光源计算方法更为精确。通过理论数据和实测数据相比较,检验了方法的正确性,并且分析了产生理论数据和实测数据一定误差的原因。以此为依据,通过M athem atica4软件计算了8154鱿钓船在海面上的光强分布,研究了8154鱿钓船合适间距的问题,认为在适宜照度0.005 lx下的合适作业间距为0.64 nm.。     

Subdiffraction multicolor imaging of the nuclear periphery with 3D structured illumination microscopy

Fluorescence light microscopy allows multicolor visualization of cellular components with high specificity, but its utility has until recently been constrained by the intrinsic limit of spatial resolution. We applied three-dimensional structured illumination microscopy (3D-SIM) to circumvent this limit and to study the mammalian nucleus. By simultaneously imaging chromatin, nuclear lamina, and the nuclear pore complex (NPC), we observed several features that escape detection by conventional microscopy. We could resolve single NPCs that colocalized with channels in the lamin network and peripheral heterochromatin. We could differentially localize distinct NPC components and detect double-layered invaginations of the nuclear envelope in prophase as previously seen only by electron microscopy. Multicolor 3D-SIM opens new and facile possibilities to analyze subcellular structures beyond the diffraction limit of the emitted light.     

甘薯茎线虫的扫描电镜制样方法

以甘薯茎线虫为材料,对取样、固定、干燥等制样方法进行比较研究.结果表明,以活线虫为研究试样,采用戊二醛 -锇酸双固定及临界点干燥法(或叔丁醇干燥法 )制样效果好,能获得良好的微形态结构,侧线数目清晰,虫体不皱缩,不变形.     

Staining tissue for light and electron microscopy by bridging metals with multidentate ligands

"Osmium black," a pigment very useful for cytological staining in both light and electron microscopy, may be deposited selectively at the tissue-binding sites of other metal ions by bridging OsO(4) to the tissue bound metal ion through a multidentate ligand.     

一种两阶段彩色图像分割方法的原木识别

针对原木图像存在年轮、锯痕以及原木之间紧密接触的问题,提出两阶段分割方法,即依据原木目标和背景的颜色差异应用K均值算法进行聚类得到相互紧密接触的原木目标分割结果;然后应用分水岭分割算法将粘连的原木目标加以分离．结果表明：与直接用分水岭算法和K均值算法相比,本方法能够有效地分割出原木目标．     

静态数字图像的信息隐藏与水印方法

数字图像的信息隐藏技术是数字图像处理领域中最具挑战性、最为活跃的研究课题之一。图像信息隐藏与水印技术主要用于数字产品的知识产权保护等。本文分别从时域替换方法和变换域方法讨论了信息隐藏的基本方法,并分别以BMP和JPEG数字图像格式为例实现了基于时域和频域的典型水印算法LSB和DCT变换域的水印过程。     

一种基于神经网络的扇贝图像识别方法

为了满足计算机视觉辅助下应用机器人进行扇贝自动分拣的实时性和鲁棒性要求,提出了一种基于神经网络的扇贝识别和分级方法.首先对图像进行灰度化处理,并用canny算子检测目标边界,然后用8-连通邻域追踪算法提取目标边界像素坐标,最后计算目标边界到中心点的平均距离及其绝对平均误差,并作为特征信息训练BP神经网络,实现对扇贝图像识别和分类.实验结果表明,该方法可以快速实现扇贝的自动识别和分级工作.     

方格法与数字图像法测定盐碱化草地植被盖度的比较

盖度是衡量植物群落结构的一个重要数量指标。试验以样方尺度下草地植被盖度为研究对象,通过精度评价和实际测定,比较了数字图像法与传统方格法之间的优劣。结果表明,与传统方格法相比,数字图像法具有误差小、准确性较高和操作简便的优点,可应用于草地植被盖度的样方测量。     

Reconstruction of zebrafish early embryonic development by scanned light sheet microscopy

A long-standing goal of biology is to map the behavior of all cells during vertebrate embryogenesis. We developed digital scanned laser light sheet fluorescence microscopy and recorded nuclei localization and movement in entire wild-type and mutant zebrafish embryos over the first 24 hours of development. Multiview in vivo imaging at 1.5 billion voxels per minute provides "digital embryos," that is, comprehensive databases of cell positions, divisions, and migratory tracks. Our analysis of global cell division patterns reveals a maternally defined initial morphodynamic symmetry break, which identifies the embryonic body axis. We further derive a model of germ layer formation and show that the mesendoderm forms from one-third of the embryo's cells in a single event. Our digital embryos, with 55 million nucleus entries, are provided as a resource.     

New method for the detection of light deflection by solar gravity

The prediction of Einstein's theory of general relativity that light will be deflected by the sun may be tested by sending radio waves from the earth to Venus or Mercury when either passes behind the sun and detecting the echoes with a radar interferometer.     

弱光照射及保鲜剂对芦笋冷藏品质的影响

采用在普通冷藏环境下引入弱光照射和化学保鲜剂6-BA、壳聚糖处理来延长芦笋的货架期,并考察弱光照射与化学保鲜剂对芦笋冷藏效果的协同作用.弱光光源使用红色发光二极管,6-BA浓度为10 mg/L,壳聚糖浓度为1.5%,定期检测芦笋的感官、失重率、Vc含量、叶绿素含量、可溶性固形物和纤维素含量6个指标.实验结果表明将弱光照射引入到普通冷藏环境,可以较好地改善芦笋的贮藏品质,在贮藏前期还可以增加芦笋的Vc含量、阻止叶绿素的降解、推迟并延长芦笋的后熟期,减缓纤维素含量的增加,但在控制芦笋失水率方面作用不大;6-BA处理和壳聚糖涂膜对芦笋贮藏品质的改善也有积极的作用.本实验期望把弱光照射和化学保鲜剂引入普通冷藏能成为一种新的芦笋保鲜工艺.     

Plasma protein synthesis in the liver: method for measurement of albumin formation in vivo

l-Arginine labeled with carbon-14 at the guanido group was injected into rabbits, and the ratio of the rates of entry of radioactivity into the protein and urea was determined. This ratio, multiplied by the rate of arginine utilization in urea synthesis and by the ratio of protein to protein arginine weights, gives the rate of protein synthesis. The method applies to albumin and should apply to any plasma protein synthesized in those liver cells which also synthesize urea.     

Goldfish retina: organization for simultaneous color contrast

The majority of ganglion cells in the retina of goldfish have receptive fields organized so that the cells respond particularly to simultaneous contrasts of color. The receptive fields are concentrically arranged. If the cell is excited by red light in the center, then it will also be excited by green light in the periphery, and inhibited by green light in the center or red light in the periphery. The occurrence of this arrangement and the reverse is about equal. The receptive field is much larger than had previously been thought.     

矢量中值滤波彩色图像增强算法研究

矢量中值作为基于排序的非线性滤波方法,在消除彩色图像的噪声和保证图像边缘与细节上均有较好的稳健性.但是,由于其算法与窗口象素数的平方成正比,因而计算量很大.本研究提出一种改进的矢量中值滤波的彩色图像增强方法,该方法既可以提高其图像处理的运算速度,又能保证图像质量,其算法具有实用价值.     

Carotenoid cation formation and the regulation of photosynthetic light harvesting

Photosynthetic light harvesting in excess light is regulated by a process known as feedback deexcitation. Femtosecond transient absorption measurements on thylakoid membranes show selective formation of a carotenoid radical cation upon excitation of chlorophyll under conditions of maximum, steady-state feedback deexcitation. Studies on transgenic Arabidopsis thaliana plants confirmed that this carotenoid radical cation formation is correlated with feedback deexcitation and requires the presence of zeaxanthin, the specific carotenoid synthesized during high light exposure. These results indicate that energy transfer from chlorophyll molecules to a chlorophyllzeaxanthin heterodimer, which then undergoes charge separation, is the mechanism for excess energy dissipation during feedback deexcitation.