荧光原位杂交技术对土壤石油降解菌的检测

从辽河油田样品中筛选出一株高效石油降解菌,经鉴定为地衣芽孢杆菌。针对其16SrRNA设计寡核苷酸探针。荧光原位杂交(FISH)技术利用寡核苷酸探针检测特定细胞内的互补核苷酸序列。通过对纯菌和泥浆中地衣芽孢杆菌的FISH进行优化,得到泥浆中地衣芽孢杆菌的荧光原位杂交实验条件:样品固定时间17h,杂交温度46℃,杂交时间3h,杂交液中去离子甲酰胺浓度35%,冲洗缓冲液中与去离子甲酰胺对应的NaCl的浓度88mmol.L-1。运用上述FISH技术监测生物泥浆反应器中地衣芽孢杆菌量的变化,并与泥浆中含油率的变化进行比较,二者的变化情况符合微生物降解石油的趋势,为监测含油污泥中微生物的变化提供了一种可行的技术。

Synthesis, characterization and crystal structures of dibenzo-18-crown-6 sodium isopolytungstates

Two novel dibenzo-18-crown-6 sodium isopolytungstates, [(DB18C6)(CH3OH)Na](2)W(6)O(19)(.)DB18C6(.)H(2)O 1 and [(DB18C6)(DMF)(2)Na](4)W(10)O(32)(.)2DMF(.)2H(2)O 2, have been synthesized in mixed methanol and acetonitrile solvents and characterized by elemental analysis, TGA, IR and single crystal X-ray diffraction. The compound 1 crystallizes in the monoclinic space group C2/c with a = 23.182(8), b = 19.527(2), c = 18.737(3) Angstrom, beta = 115.15(2)degrees, V = 7678(3) Angstrom(3), Z = 4, and R1(wR2) = 0.0611(0.1504). The compound 2 crystallizes in the monoclinic space group P21/n with a = 16.516(2), b = 22.325(6), c = 20.425(7) Angstrom, beta = 91.78(2)degrees, V = 7528(3) Angstrom(3), Z = 2, and R1(wR2) = 0.0397(0.0773). The compound 1 exhibits a novel organic-inorganic sandwich-type structure, in which the crown ether-sodium complexes are coordinated to the terminal oxygen atoms of W6O192-. In compound 2, all Na+ ions are thoroughly enveloped into the organic moieties of crown ether and DMF molecules and are connected with the 'naked' polyanions W10O324- via the electrostatic attraction.

软体动物线粒体基因组学及分子系统发生研究

本研究以双壳纲、翼形亚纲、珍珠贝目、扇贝超科的栉孔扇贝(Chlamys farreri )、海湾扇贝(Argopecten irradians)和牡蛎超科巨蛎属(Crassostrea)的长牡蛎(C. gigas)、葡萄牙牡蛎(C. angulata)、熊本牡蛎(C. sikamea)、香港巨牡蛎(C. hongkongensis)和近江牡蛎(C. ariakensis)5种牡蛎及异齿亚纲、帘蛤目、帘蛤科的紫斑文蛤(Meretrix pethechialis)为研究对象，系统的研究了以上物种的线粒体基因组全序列的特点。并以线粒体12个蛋白质编码基因的序列，在氨基酸和核苷酸水平上构建了软体动物的分子系统发生树。本研究旨在为利用线粒体基因组全序列全面构建软体动物分子系统发生树，为软体动物的系统发生和进化研究提供一种新的思路和前期基础工作，本研究主要内容分为以下三个部分： 一、栉孔扇贝和海湾扇贝线粒体基因组序列分析及分子系统发生研究 采用Long-PCR技术扩增了栉孔扇贝和海湾扇贝线粒体全基因组，利用步移法结合文库构建的测序策略获得了线粒体基因组的序列。海湾扇贝线粒体全基因组长度为16,211 bp，栉孔扇贝接近全序列长度为20,789 bp。两个基因组都编码35个基因，包括12个蛋白质编码基因，2个rRNA和21个tRNA。与典型的动物线粒体基因组相比，两个基因组都缺少一个蛋白质编码基因atp8和2个trnS, 在海湾扇贝基因组中有1个trnF的重复，而在栉孔扇贝基因组中有1个trnM的重复。基因排列比较显示，尽管海湾扇贝、栉孔扇贝和巨扇贝分类学上属于同一扇贝科，但是它们的线粒体基因排列非常不同。在四种扇贝中，虾夷扇贝与栉孔扇贝的基因排列顺序非常相似；即使排除tRNA的比较，栉孔扇贝和海湾扇贝基因组仅仅共享三个小的基因块；而海湾扇贝与巨扇贝仅有一个相同的基因块。在所有的系统发生分析中，四种扇贝稳定的系统发生关系得到强有力的支持，海湾扇贝较其他三种扇贝较早的分化出来；栉孔扇贝比其他两种扇贝与虾夷扇贝亲缘关系更近。贝叶斯法和最大似然法分析都支持扇贝超科的单系发生。 二、巨蛎属牡蛎线粒体基因组全序列分析及分子系统发生研究 采用Long-PCR扩增技术和步移法结合文库构建的技术策略获得了巨蛎属C. gigas、C. angulata、C. sikamea、C. hongkongensis和C. ariakensis 5种牡蛎线粒体全基因组序列，并于GenBank已公布的美洲牡蛎C.virginica序列进行比较研究。C. gigas、C. angulata、C. sikamea、C. hongkongensis和C. ariakensis线粒体全基因组长度分别为18,225 bp、18,225 bp、18,243 bp、18,622 bp和18,414 bp，都长于C. virginica基因组17,244 bp的长度。本研究的5种牡蛎线粒体基因组都编码39个基因，包括12个蛋白质编码基因，2个rRNA和25个tRNA。与典型的线粒体基因组相比，都缺少一个蛋白质编码基因atp8，有trnM、trnK和trnQ 3个tRNA基因的重复，更特别的是基因组中的rrnL分为两段，这在其它线粒体基因组中未见报道，有一个重复的rrnS；而C. virginica基因组编码37个基因，与其他牡蛎相比，没有trnK和trnQ重复，只有一个rrnS。基因排列比较显示，巨蛎属的5种牡蛎C. gigas、C. angulata、C. sikamea、C. hongkongensis和C. ariakensis基因排列完全一致，而与C. virginica的基因排列相比仍然有较大的差别，有多个tRNA发生易位。系统发生分析显示，C. gigas和C. angulata首先聚在一起，然后与C. sikamea聚为一支。C. hongkongensis和C. ariakensis聚成一支。C. virginica为单独的一支。系统树清楚的显示出C. gigas和C. angulata以及C. hongkongensis和C. ariakensis非常近的亲缘关系，这也是长期以来，牡蛎分类学上的经典问题，有学者认为C. gigas和C. angulata为同一物种，线粒体基因组的数据显示C. gigas和C. angulata可能达到不同物种的差异。传统分类上的“近江牡蛎”的“白蚝”和“赤蚝”，线粒体序列差别明显，完全支持两种牡蛎新种名的制定。 三、紫斑文蛤线粒体基因组全序列分析及分子系统发生研究 采用Long-PCR扩增技术和步移法结合文库构建的技术策略获得了紫斑文蛤线粒体基因组全序列。该基因组全长19,567 bp，编码36个基因，包括12个蛋白质编码基因，2个rRNA和22个tRNA。与典型的线粒体基因组相比，缺少一个蛋白质编码基因atp8和1个trnS, 有1个trnQ基因的重复。基因排列比较显示，双壳类的基因排列在低的分类阶元时相对保守。在帘蛤科中，紫斑文蛤M. petechialis和菲律宾蛤仔V. philippinarum共享四个完全一致的基因块，两个大的基因块是cox1-L1-nad1-nad2-nad4L-I 和 cox2-P-cob-rrnL-nad4-H-E-S2-atp6-nad3-nad5，另两个小基因块只包括tRNA基因。在以氨基酸序列构建的分子系统树中，帘蛤科紫斑文蛤与菲律宾蛤仔首先聚在一起，然后，它们与A. tuberculata形成一个进化枝。这一枝与H. arctica结合起来，支持异齿亚纲单系发生。

北京石花洞滴水沉积的季节变化及影响因素

Because of the high resolution, stalagmite laminae can play an important role in the paleoclimate reconstructions. However, few investigations for the formation mechanisms of stalagmite lamilae have been done. Based on two-year observation on calcite growth rate at the drip sites, three-year monitoring of hydrodynamics, physics and chemistry of drip waters at different drip sites and the surrounding environments inside and outside the Beijing Shihua Cave, the seasonal variations of calcite growth rate are revealed and the results can be concluded as follows: 1. The drip waters inside the Cave are mostly sourced from the summer rain, and its minimal response-time to the atmospheric precipitation is less than one day. There are three types of response relationships between the precipitation and the drip rate variations: rapid response type, time-lag response type and stable response type. For rapid response type, the drip discharge is recharged through the flow routes along intensive fractures and interconnectivities; for time-lag response type, the drip discharge is recharged by double-porosity system composed of a high conductivity, low storage capability conduit network and a low-conductivity high-storage capability rock matrix under variable boundary conditions; for stable response type, the drip discharge is mainly recharged by seepage flow and base flow. 2. The observation shows that, inside the Cave, the growth rate of calcite is generally lower in rainy seasons and higher in dry seasons. During the rainy seasons, the drip water is characterized by a lower pH value, higher [Ca2+], [Mg2+], [SO42-] and electrical conductivity (EC) values. According to the calculations of saturation index of calcite (SIc), pCO2 of the drip water, as well as the synthetical analysis of other possible factors, the calcite growth rate is found to be principally influenced by the drip water saturation index of calcite (SIc). And the drip rate and pCO2 in the drip water and in the cave air play the secondly important roles in this process. The recharge mode of heavy rainfall events in the rainy seasons should probably be the main driving force that controls the physicochemical properties and calcite sediment of the drip waters. The abrupt decrease of sedimentary rate and the sharp peak of DOC in drip water in the rainy season probably forms the thin opaque (luminescent under ultraviolet radiation) layers observed in the stalagmites, whereas the relatively higher sedimentary rate in the dry seasons may be responsible for the thicker bright layers. The investigation elucidated here preliminarily reveals the formation mechanism of the stalagmite laminae in Beijing Shihua Cave.

Corporations and corporate governance: what do these concepts mean for multinational corporate power and social responsibility?

International Journal of Liability and Scientific Enquiry 2007 - Vol. 1, No.1/2 pp. 29 - 49 RAE2008

Behaviour and rationality in corporate governance

Marnet, Oliver, 'Behaviour and rationality in corporate governance', Journal of Economic Issues (2005) 39(3) pp.613-632 RAE2008

Impact of Islamic values on HRM practices: an empirical study of Jordanian universities

Purpose This study aims to present an in-depth theoretical and practical analysis of HRM practice in the light of Islamic values and principles. It looks at the four main HRM functions of recruitment and selection, training and development, performance appraisal, and rewards, from the Islamic perspective. Besides establishing a theoretical base for the influence of Islam on HRM, it analyses the key characteristics of HRM practice as applied in Jordanian universities and analyses the extent to which Islamic values are embedded in that practice. Design/methodology/approach The paper draws on a structured questionnaire distributed to 500 respondents working in four Jordanian universities which sought to elicit the respondents views on the influence of Islamic values within specific HR functions. Findings The findings indicate that there is a diffusion of Islamic values into HRM practice in the participating organisations. The extent of the diffusion varies between the organisations; there is a clear indication that explicitly Islamic values are being practiced, albeit to a limited extent. Originality/value The role of spirituality and/or religion in shaping the working of contemporary organisations is not sufficiently recognised in the literature. This paper is a response to the limited number of research studies assessing the extent of the absorption of religious values into the management of human resources. The study undertaken examines the current status of HRM practice in Jordanian universities and contributes to deepening the contemporary understanding of interactions between Islamic values and the core HR functions.

The mechanical and thermal structure of Mercury's early lithosphere

Cook, Anthony; Watters, T.R.; Schultz, R.A.; Robinson, M.S., (2002) 'The mechanical and thermal structure of Mercury's early lithosphere', Geophysical Research Letters 29(11) pp.1542 RAE2008

Discovering Clusters in Motion Time-Series Data

A new approach is proposed for clustering time-series data. The approach can be used to discover groupings of similar object motions that were observed in a video collection. A finite mixture of hidden Markov models (HMMs) is fitted to the motion data using the expectation-maximization (EM) framework. Previous approaches for HMM-based clustering employ a k-means formulation, where each sequence is assigned to only a single HMM. In contrast, the formulation presented in this paper allows each sequence to belong to more than a single HMM with some probability, and the hard decision about the sequence class membership can be deferred until a later time when such a decision is required. Experiments with simulated data demonstrate the benefit of using this EM-based approach when there is more "overlap" in the processes generating the data. Experiments with real data show the promising potential of HMM-based motion clustering in a number of applications.

Proteomic approach to oxidative stress in Daphnia magna

The keystone aquatic organism Daphnia magna is extensively used to assess the toxicity of chemicals. This has recently lead to an increase in the omics literature focusing on daphnids, an increase fuelled by the sequencing of the Daphnia pulex genome. Yet, no omics study has looked directly at oxidative stress (OS) in daphnids, even though OS is of primary importance in the response of aquatic organisms to their changing environment and is often induced by anthropogenic xenobiotics. This thesis thus focuses on the application of redox-proteomics, the study of the oxidative modification of proteins, to D. magna Specifically, daphnids were exposed to copper or paraquat, two well studied prooxidants, and protein carbonyls were labelled with fluorescein-5-thiosemicarbazide prior to twodimensional electrophoresis (2DE). This showed clearly that both compounds affect a different portion of the proteome. The identified proteins indicated that energy metabolism was affected by paraquat, while copper induced a reduction of the heat shock response (heat shock proteins, proteases and chaperones) a counterintuitive result which may be adaptative to metal toxicity in arthropods. The same approach was then applied to the study of the toxicity mechanism of silver nanoparticles (AgNP), an increasingly utilised form of silver with expected environmental toxicity, and its comparison to silver nitrate. The results demonstrate that, although less toxic than silver ions, AgNP toxicity functions through a different mechanism. AgNP toxicity is thus not a product of silver dissolution and increased protein carbonylation indicates that AgNP cause OS. Interestingly three of the four tested compounds altered vitellogenin levels and oxidation. Vitellogenins could thus represent an interesting subproteome for the detection of stress in daphnids. Finally, an experiment with oxidised BSA demonstrates the applicability of solid phase hydrazide in the enrichment of undigested carbonylated proteins.

Plate-specific gain map correction for the improvement of detective quantum efficiency in computed radiography.

PURPOSE: The purpose of this work is to improve the noise power spectrum (NPS), and thus the detective quantum efficiency (DQE), of computed radiography (CR) images by correcting for spatial gain variations specific to individual imaging plates. CR devices have not traditionally employed gain-map corrections, unlike the case with flat-panel detectors, because of the multiplicity of plates used with each reader. The lack of gain-map correction has limited the DQE(f) at higher exposures with CR. This current work describes a feasible solution to generating plate-specific gain maps. METHODS: Ten high-exposure open field images were taken with an RQA5 spectrum, using a sixth generation CR plate suspended in air without a cassette. Image values were converted to exposure, the plates registered using fiducial dots on the plate, the ten images averaged, and then high-pass filtered to remove low frequency contributions from field inhomogeneity. A gain-map was then produced by converting all pixel values in the average into fractions with mean of one. The resultant gain-map of the plate was used to normalize subsequent single images to correct for spatial gain fluctuation. To validate performance, the normalized NPS (NNPS) for all images was calculated both with and without the gain-map correction. Variations in the quality of correction due to exposure levels, beam voltage/spectrum, CR reader used, and registration were investigated. RESULTS: The NNPS with plate-specific gain-map correction showed improvement over the noncorrected case over the range of frequencies from 0.15 to 2.5 mm(-1). At high exposure (40 mR), NNPS was 50%-90% better with gain-map correction than without. A small further improvement in NNPS was seen from carefully registering the gain-map with subsequent images using small fiducial dots, because of slight misregistration during scanning. Further improvement was seen in the NNPS from scaling the gain map about the mean to account for different beam spectra. CONCLUSIONS: This study demonstrates that a simple gain-map can be used to correct for the fixed-pattern noise in a given plate and thus improve the DQE of CR imaging. Such a method could easily be implemented by manufacturers because each plate has a unique bar code and the gain-map for all plates associated with a reader could be stored for future retrieval. These experiments indicated that an improvement in NPS (and hence, DQE) is possible, depending on exposure level, over a wide range of frequencies with this technique.

Liquid metal induction heating modelling for cold crucible applications

The time dependent numerical model of cold crucible melting is based on the coupled electromagnetic, temperature and turbulent velocity field calculation accounting for the magnetically confined liquid metal shape continuous change. The model is applied to investigate the process energy efficiency dependence on the critical choice of AC power supply frequency and an optional addition of a DC magnetic field. Test cases of the metal load up to 50 kg are considered. The behaviour of the numerical model at high AC frequencies is instructively validated by the use of the electromagnetic analytical solution for a sphere and temperature measurements in a commercial size cold crucible furnace