Effect of water temperature on digestive enzyme activity and gut mass in sea cucumber Apostichopus japonicus (Selenka), with special reference to aestivation

The effect of water temperature on gut mass and digestive enzyme activity in sea cucumber Apostichopus japonicus, including relative gut mass (RGM), amylase, lipase, pepsin and trypsin activities were studied at temperatures of 7, 14, 21, and 28A degrees C over a period of 40 days. Results show that RGM significantly decreased after 40 days at 21A degrees C and markedly decreased over the whole experiment period at 28A degrees C; however, no significant effect of duration was observed at 7 or 14A degrees C. At 14A degrees C, trypsin activity significantly decreased over 10 and 20 days, then increased; amylase and trypsin activity significantly decreased after 40 days at 28A degrees C. However, no significant effect of duration was found on amylase, pepsin or trypsin activities in the other temperature treatment groups. At 28A degrees C, lipase activity peaked in 20 days and then markedly decreased to a minimum at the end of the experiment. On the other hand, pepsin activity at 28A degrees C continuously increased over the whole experimental period. Principle component analysis showed that sea cucumbers on day 40 in the 21A degrees C group and in the previous 20 days in the 28A degrees C group were in the prophase of aestivation. At 28A degrees C, sea cucumbers aestivated at 30-40 days after the start of the experiment. It is concluded that the effect of temperature on the digestion of A. japonicus is comparatively weak within a specific range of water temperatures and aestivation behavior is accompanied by significant changes in RGM and digestive enzyme activities.

Identification of Crassostrea ariakensis and related oysters by multiplex species-specific PCR

Genetic markers are needed for rapid and reliable identification of oysters. In this study, we developed multiplex genus- and species-specific PCR markers for the identification of oysters from China. We used the mitochondrial cytochrome oxidase I (COI) and nuclear 28S ribosomal RNA genes for marker development. DNA sequences from different species were obtained from GenBank or by direct sequencing. Sequences were aligned, and genus- and species-specific nucleotides were identified. Primers were designed for genus/species-specific amplification to generate fragments of different sizes. A multiplex set of genus- and species-specific primers from the 28S gene was able to separate C. ariakensis and C. hongkongensis from other species and assign oysters to four genera. A set of species-specific COI primers provided positive identification of all five Crassostrea species from China, C. ariakensis, C. hongkongensis, C. angulata, C. gigas, and C. sikamea in a single PCR. The multiplex PCR assays do not require fluorescence-labeling or post-PCR enzyme digestion, providing a simple, fast and reliable method for the identification of oysters from China.

Proteomic detection of changes in protein expression induced by cordycepin in human hepatocellular carcinoma BEL-7402 cells

The nucleoside analogue cordycepin (3'-deoxyodenosine, 3'-dA), one of the components of cordyceps militaris, has been shown to inhibit the growth of various tumor cells. However, the probable mechanism is still obscure. In this study, the inhibition of cell growth and changes in protein expression induced by cordycepin were investigated in BEL-7402 cells. Using the MTT assay and flow cytometry, we found that cordycepin inhibits cell viability and induces apoptosis in BEL 7402 cells. Additionally. the proteins were separated using two-dimensional polyacrylamide gel electrophoresis, and eight proteins were found to be significantly, affected by cordycepin compared to untreated control; among them, two were downregulated and six were upregulated. Of the eight proteins, six were identified with peptide mass fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) after in-gel trypsin digestion. These proteins are involved in various aspects of cellular metabolism. It is suggested that the effect of cordycepin on the growth of tumor cells is significantly related to the metabolism-associated protein expression induced by cordycepin. Copyright 2008 Prous Science, S.A.U. or its licensors. All rights reserved.

Growing season ecosystem respirations and associated component fluxes in two alpine meadows on the Tibetan Plateau

From 30 June to 24 September in 2003 ecosystem respiration (Re) in two alpine meadows on the Tibetan Plateau were measured using static chamber- and gas chromatography- (GC) based techniques. Simultaneously, plant removal treatments were set to partition Re into plant autotrophic respiration (Ra) and microbial heterotrophic respiration (Rh). Results indicated that Re had clear diurnal and seasonal variation patterns in both of the meadows. The seasonal variability of Re at both meadow sites was caused mainly by changes in Ra, rather than Rh. Moreover, at the Kobresia humilis meadow site (K_site), Ra and Rh accounted for 54% and 46% of Re, respectively. While at the Potentilla fruticosa scrub meadow (P_site), the counterparts accounted for 61% and 39%, respectively. T test showed that there was significant difference in Re rates between the two meadows (t = 2.387, P = 0.022). However, no significant difference was found in Rh rates, whereas a significant difference was observed in Ra rates between the two meadows. Thus, the difference in Re rate between the two meadows was mainly attributed to plant autotrophic respirations. During the growing season, the two meadows showed relatively low Q(10) values, suggesting that Re, especially Rh was not sensitive to temperature variation in the growing season. Additionally, Re and Rh at the K_site, as well as Rh at the P_site was negatively correlated with soil moisture, indicating that soil moisture would also play an important role in respirations.

Competition between Stipa grandis and Cleistogenes squarrosa

Competitive strategy for resources between Cleistogenes squarrosa (Trin.) Keng which is a dominant species of grasslands degraded by moderate-heavy grazing, and Stipa grandis P. Smirnov, which is a dominant species of ungrazed communities, was studied using a replacement series method in a greenhouse. The knowledge would be helpful in managing grasslands and restoring the degraded C. squarrosa grassland. Although there was neither inter- nor intra-specific competition between the two species when no nutrients were added, intra-specific competition of C. squarrosa was observed and increased with increased nutrient availability and more sulfur (S) was allocated to the aboveground partition of the plant. Relative competitive ability of C. squarrosa was greater than that of S. grandis when nutrients were supplied regardless of S. There was no significant difference between shoot and root competition based on dry matter yields. However, root competition was significantly greater than that of shoot based on S uptake under all treatments. A significant interaction was not observed between shoot and root competition. Therefore, nutrients addition benefits the restoration of degraded grassland of C. squarrosa, which may not exclude S. grandis. Also productivity and forage quality of the community will be increased. (C) 2007 Elsevier Ltd. All rights reserved.

Effects of azadirachtin on hemolymph protein expression in Ostrinia furnacalis (Lepidoptera : Crambidae)

The botanical insecticide azadirachtin affects a variety of biological processes. Our early work indicated that protein level and type are significantly influenced by azadirachtin in pupae of Osttiniafumacalis (Guenee) (Lepidoptera: Crambidae) because a correlation exists between protein content and azadiraebtin concentration. By use of proteomic techniques, we analyzed changes in hemolymph protein expression of 48-h-old pupae in O. furnacalis induced by azadirachtin treatment. After feeding by third instars on an artificial diet containing 10 ppm azadirachtin until pupation, 48-b-old pupae were collected, and hemolymph protein samples were prepared. They were separated by two-dimensional polyacrylamide gel electrophoresis, and six proteins were significantly affected by azadiracbtin treatment compared with an untreated control. Two of these proteins were identified by database searching with peptide mass fingerprinting by using matrix-assisted laser desorption/ time-of-flight mass spectrometry after in-gel trypsin digestion. They belong to the insect apolipophorin-III and phospboribosyltransferase family, respectively. These two proteins may function on lipid metabolism in insect hemolymph. Furthermore, fat body is the center of synthesis and secretion of hemolymph proteins. We suggest that the azadirachtin exerts its insecticidal effects on the fat body of O. furnacalis by interfering with protein expression related to hemolymph lipid metabolism.

Digestibility, nutrient balance and urinary purine derivative excretion in dry yak cows fed oat hay at different levels of intake

A feeding trial A as conducted at the farm of Qinghai Academy of Animal and Veterinary Science, Xining, China during 1996 - 1997 with three dry yak cows (initial body weight 163 - 197 kg, age 5 - 6 years) by using 3 x 3 Latin Square Design to determine the effect of levels of feed intake on digestion, nitrogen balance and purine derivative excretion in urine of yak cows. The animals were fed oat hay (nitrogen 13.5 g/kg dry matter (DM), metabolisable energy 8.3 MJ/kg DM), i.e., 0.3, 0.6 and 0.9 of voluntary intake (VI). Each intake treatment lasted for 17 days and the samples (feeds, faeces and urine) were collected during last 7 days of each period. The results indicate that digestibility of dietary DM, OM, NDF and ash declined when intake levels increased from 0.3 to 0.9 VI [DM, from 66.1% to 59.1% (P < 0.05); OM, from 68.1% to 59.9% (P < 0.05); NDF, from 62.1% to 54.3% (P < 0.05); and ash, from 33.9% to 11.8% (P < 0.05)]. Around 0.10 g N/kg W-0.75 was deficient daily in yak cows at 0.3 VI, and positive N balances were observed at 0.6 and 0.9 VI. Intake levels significantly (P < 0.05) affected total PD excretion in yak urine. The proportion of allantoin increased (P < 0.05) and uric acid decreased (P < 0.05) as intake level of feed increased. (C) 2004 Elsevier B.V. All rights reserved.

制造执行系统的边界划分方法研究

介绍了制造执行系统(MES)的含义和实现的核心功能,提出了目前信息化建设过程中存在的边界问题,针对出现的问题,给出了MES与其它系统的边界划分方法:功能边界与技术边界两种方法。并根据研究结果分析了MES与ERP、MES与PCS系统的边界划分。

改进的符号时间序列分析方法及其在电机故障诊断中的应用

提出了一种改进的基于符号时间序列分析的电机异常探测方法,该方法自适应地将符号序列中出现符号最多的符号区间重新划分为2个新的符号区间,使得数据密集区间可以分配到相对更多的符号,而数据稀疏区间则分配到较少的符号,提高了符号对于信号变化的灵敏度。电机转子断条故障的诊断实验结果表明:该方法较平均划分区间的方法对于电机异常诊断有着更高的灵敏度以及更好的鲁棒性和可靠性。

多机器人动态编队的强化学习算法研究

在人工智能领域中 ,强化学习理论由于其自学习性和自适应性的优点而得到了广泛关注 随着分布式人工智能中多智能体理论的不断发展 ,分布式强化学习算法逐渐成为研究的重点 首先介绍了强化学习的研究状况 ,然后以多机器人动态编队为研究模型 ,阐述应用分布式强化学习实现多机器人行为控制的方法 应用SOM神经网络对状态空间进行自主划分 ,以加快学习速度 ;应用BP神经网络实现强化学习 ,以增强系统的泛化能力 ;并且采用内、外两个强化信号兼顾机器人的个体利益及整体利益 为了明确控制任务 ,系统使用黑板通信方式进行分层控制 最后由仿真实验证明该方法的有效性

一种基于工艺特征的制造单元划分方法

在现代生产中,单元化生产是提高制造系统生产效率的一个重要手段。对于一个给定的制造系统,其中制造单元的划分并不是唯一的,人们提出了各种制造单元划分方法。这些方法的不足是只采用0和1两值来表示系统中的相似关系。本文提出了相似系数和隶属度的概念,进一步发展了一种完善的制造单元划分方法,最后以一个数值例子进行了验证。

混流汽车总装配线上的零部件优化配送方案研究

配送车每次配送的利用率大小是提高配送效率的主要因素,因此设计一种启发式算法使配送车一次装载的标准塑料周转箱尽可能多,提高配送车空间利用率。最后的仿真实验验证了上述配送方法的实用性,提出的零部件配送管理方法,只需使用较少的配送工人,同时降低了线旁库存,能为企业节省人力,降低生产成本。

可重构车间管理系统的关键设计技术研究

介绍了一个基于组件的可重构车间管理系统,分别从建模方法、体系结构和组件设计等角度描述了系统的设计思想,并阐述了系统涉及的组件分类、组件粒度划分及XML的应用等关键设计技术。开发的可重构车间管理系统已经用于沈阳第一机床厂两个不同类型生产车间的管理,应用效果良好。

孤岛油田曲流河微相单砂体储层建筑结构及挖潜方向研究

In the intermediary and later stage of oil field development, remaining oil disperses fiercely, the contradiction in the layer has become the main problem and the distribution of remaining oil is transforming to the difference of single sand-body. So, the fine description research of reservoir is becoming a tendency and the methods of remaining oil research need new developments. In the research of “The Single-sand-body Architectural Element and Potentiality Analysis Research of Meandering River, GuDao Oil Field”, the research principle is analytical hierarchy process and schema prescription what are reservoir fine description methods under the condition of dense well pattern. The knowledge of regional sedimentary system and sedimentary facies is the foundation of this research. According to the 3D distribution model of the microfacies sand-body of fluvial facies, stratigraphic unit classification & coenocorrelation of 154 wells are completed in the research of meandering river sand-body in Ng3-4. In this research, the 3D distribution of microfacies sand-body in the main layers are settled. The architectural element model of Ng4 point bar is analysed using the drill core and FMI data. According to the overgrow model of point bar, the surfaces of lateral accretion is traced and the architectural element model of point bar is settled. In the research, the control of micro-facies sand-body of meandering river to the distribution of remaining oil is analysed and the potential area is proposed. All these will play an important role in the development of GuDao oil field. In this research, abundant of logging data, drill core data and production performance data are used to analyse the contributing factor of single sand-body in the Ng3-4 meandering river. Using the technology of geological modeling, all that are researched including the 3D distribution scales of meandering river point bar, the control affection of inner lateral accretion layer to the distribution of oil & gas and remaining. Then, the way of remaining oil development in the sand-body of meandering river is improved. The innovation of the research technology includes (1) the presentation of the conception and research methods of micro-facies sand-body (2) enriching the content of reservoir architectural element research and (3) to renew the research method of remaining oil analysis. The research has practiced with obvious effect.(1)It is deepened into understand the river facies reservoir construction of Gudao oil field, By Building the reservoir construction and studying the effect of diffent deposit or geological interface to fluid partition and to the distribution of the remaining oil, we improved the understanding to the distribution of the remaining oil；(2)By building the distribution mod of the remaining oil in the reservoir construction and making the remaining oil description detailed,the development direction of old oil field is more clear；(3)Expanded the application scales of the horizontal well and enhanced the application effects of the horizontal well technique , we designed and drilled 23 ports horizontal wells in all , the cumulative hydrocarbon production is 10.6*104 t；(4) According to the findings of the internal building structure in reservoir of the fluvial facies in the region of interest, and uniting the injection/production corresponding states、the producing history and the dynamic monitoring documents of the oil/water wells in the flooding units , we researched the residual oil distribution in the point bar , and found the distribution regular patterns of the remaining oil, and comprehended the distribution of the remaining oil . In base of that , we proceeded the optimizing designs of the oil well potentialities , and advanced the effect of the treatment potentials . It is proved that , it was very important that internal building structure research of the single sand body of reservoir for guiding the high efficiency potentialities of the remaining oil in the high water cut stage .

徐家围子断陷连片叠前时间偏移处理方法研究

In this paper, the detailed analysis of fundamental seismic data and theoretical method are given, and the tests of some new technologies are performed. For seismic data processing assembly, some key technologies are developed and applied, such as global static correction, amplitude consistency processing, wavelet consistency shaping, fine velocity model establishing and prestack time migration. These technologies can efficiently settle the problems during the course of multiple- block– jointed prestack time migration processing, and it is highly significant for holding the oil output of 40,000,000 tons for Daqing oilfield. Through the research of this dissertation, the following important contributions are shown: (1) The combination of near-surface model method and refraction static correction method is developed, and is applied to solve global static correction for the whole merging area. (2) Prestack amplitude normalization processing method based on fold is developed. The method eliminates the effects of fold on amplitude uniformity, and solves the problem of energy uniformity for tie-area prestack migration processing. (3) Wavelet consistency is investigated. For multiple survey blocks existing in the area, the optimum method of wavelet shaping is developed, which removes the waveform variance between two adjacent blocks. (4) Controlled velocity inversion (CVI) technique is used to establish migration velocity field. It can largely shorten the period of velocity modeling, and improve velocity analysis precision. (5) Float datum level technique is employed, and is able to guarantee prestack migration results of subsurface shallow layers. (6) The static partition of seismic data volume relating to migration aperture is firstly developed. And the precious imaging for huge data volume by prestack time migration is realized. (7) The numerical forward simulation and prestack migration processing is primarily combined to discuss the migration technique for a complex geology structure from practical field information. The combination of numerical simulation and prestack migration is a feasible way to solve the fine imaging of complex volcanic structure. And the combination approach can help to select appropriate migration parameters.