荧光原位杂交技术(FISH)及其在环境微生物学中的应用

微生物对整个生态系统具有重要的影响,了解和检测微生物的种类具有十分重要的意义。但是传统的培养方法又不能满足科学研究的需要,荧光原位杂交技术(ＦＩＳＨ)就是近年发展起来的一种快速准确检测微生物的方法。作者较全面地介绍了ＦＩＳＨ技术的优点、微生物的分离和固定方法,以及原位杂交过程,同时对ＦＩＳＨ技术在环境微生物学中的应用及其前景作了展望。

Empathy for pain involves the affective but not sensory components of pain.

Our ability to have an experience of another's pain is characteristic of empathy. Using functional imaging, we assessed brain activity while volunteers experienced a painful stimulus and compared it to that elicited when they observed a signal indicating that their loved one--present in the same room--was receiving a similar pain stimulus. Bilateral anterior insula (AI), rostral anterior cingulate cortex (ACC), brainstem, and cerebellum were activated when subjects received pain and also by a signal that a loved one experienced pain. AI and ACC activation correlated with individual empathy scores. Activity in the posterior insula/secondary somatosensory cortex, the sensorimotor cortex (SI/MI), and the caudal ACC was specific to receiving pain. Thus, a neural response in AI and rostral ACC, activated in common for "self" and "other" conditions, suggests that the neural substrate for empathic experience does not involve the entire "pain matrix." We conclude that only that part of the pain network associated with its affective qualities, but not its sensory qualities, mediates empathy.

Control of bimanual rhythmic movements: Trading efficiency for robustness depending on the context

This paper investigates how the efficiency and robustness of a skilled rhythmic task compete against each other in the control of a bimanual movement. Human subjects juggled a puck in 2D through impacts with two metallic arms, requiring rhythmic bimanual actuation. The arms kinematics were only constrained by the position, velocity and time of impacts while the rest of the trajectory did not influence the movement of the puck. In order to expose the task robustness, we manipulated the task context in two distinct manners: the task tempo was assigned at four different values (hence manipulating the time available to plan and execute each impact movement individually); and vision was withdrawn during half of the trials (hence reducing the sensory inflows). We show that when the tempo was fast, the actuation was rhythmic (no pause in the trajectory) while at slow tempo, the actuation was discrete (with pause intervals between individual movements). Moreover, the withdrawal of visual information encouraged the rhythmic behavior at the four tested tempi. The discrete versus rhythmic behavior give different answers to the efficiency/robustness trade-off: discrete movements result in energy efficient movements, while rhythmic movements impact the puck with negative acceleration, a property preserving robustness. Moreover, we report that in all conditions the impact velocity of the arms was negatively correlated with the energy of the puck. This correlation tended to stabilize the task and was influenced by vision, revealing again different control strategies. In conclusion, this task involves different modes of control that balance efficiency and robustness, depending on the context. © 2008 Springer-Verlag.

Delayed control of a Moore-Greitzer axial compressor model

Several feedback control laws have appeared in the literature concerning the stabilization of the nonlinear Moore-Greitzer axial compression model. Motivated by magnitude and rate limitations imposed by the physical implementation of the control law, Larsen et al. studied a dynamic implementation of the S-controller suggested by Sepulchre and Kokotović. They showed the potential benefit of implementing the S-controller through a first-order lag: while the location of the closed-loop equilibrium achieved with the static control law was sensitive to poorly known parameters, the dynamic implementation resulted in a small limit cycle at a very desirable location, insensitive to parameter variations. In this paper, we investigate the more general case when the control is applied with a time delay. This can be seen as an extension of the model with a first-order lag. The delay can either be a result of system constraints or be deliberately implemented to achieve better system behavior. The resulting closed-loop system is a set of parameter-dependent delay differential equations. Numerical bifurcation analysis is used to study this model and investigate whether the positive results obtained for the first-order model persist, even for larger values of the delay.

曝气-混凝一体法去除碱性废水中砷的研究

采用曝气－混凝一体法处理碱性含砷废水。氧化方式研究表明，以曝气替代混凝机械搅拌过程，既起到氧化作用，又完成了混合作用，同时具有较好的处理效果；采用该法结合二次混凝工艺处理高浓度碱性含砷废水（砷浓度达４１４．９４ｍｇ／Ｌ），聚合铁为絮凝剂，总Ｆｅ／Ａｓ＝３．０，砷去除率９９．９２％，出水中砷浓度０．３３ｍｇ／Ｌ；在所选用的三种混凝剂中，聚合铁处理效果最佳。

我国对虾暴发性流行病病因初探

我国对虾暴发性流行病病因初探江育林，张奇亚，刘荭，李彦，李正秋（中国科学院水生生物研究所武汉４３００７２）关键词杆状病毒、对虾病毒病、中国对虾、日本对虾ＳＴＵＤＹＯＮＣＡＵＳＥＯＦＩＮＦＥＣＴＩＯＮＳＤＩＳＥＡＥＳＯＦＰＥＮＡＥＩＤＳＨＲＩＭＰＩＮＣ...

Structural and optical properties of III-V nanowires and nanowire heterostructures grown by metalorganic chemical vapour deposition

We have investigated the structural and optical properties of III-V nanowires grown by metalorganic chemical vapour deposition. Binary GaAs, InAs and InP nanowires, and ternary InGaAs and AlGaAs nanowires, have been fabricated and characterised. A variety of axial and radial heterostructures have also been fabricated, including GaAs/AlGaAs core-multishell and GaAs/InGaAs superlattice nanowires. GaAs/AlGaAs core-shell nanowires exhibit strong photoluminescence as the AlGaAs shell passivates the GaAs nanowire surface reducing the surface nonradiative recombination. © 2007 IEEE.

水质酸化和模拟酸雨对浮游动物影响的研究

在水质酸化和模拟酸雨试验中,共出现浮游动物17种,其中包括轮虫9种、枝角类6种和桡足类2种。在pH5.0—8.3各试验组出现种类数(10—13种)和个体数(223.0—334.5个·L~(-1))较多,而在pH3.0和4.5试验组出现种类数(5—9种)和个体数(16.8—182.0个·L~(-1))较少,表明pH5.0以下对浮游动物群落有明显的影响。从不同类群出现所占比例看,在pH5.5以下,随着pH的下降,存在着轮虫逐渐取代桡足类的趋势。

复合四倍体异育银鲫产生的细胞学机制

<正> 银鲫是行天然雌核发育生殖的鱼类。以往对其繁殖生物学的研究一般都认为:异源父本的性状不能或仅能少量地在子代群体中得到表达。但桂建芳等(1991)在人工繁育的异育银鲫群体中发现了具有一整套父本染色体组的复合四倍体鱼,其出现率为0.2％左右。此外,Kobayasi

关于分布类型各检验方法的讨论

<正> 在现代生物数学中,常常需要对数据的分布类型作正态性检验。然而,在常用的分布类型检验方法中,由于各方法的侧重点不同,应用条件也不尽相同,因而对于某一类具体问题,各检验方法的检验效率也不同。因此,有必要对常用的几种分布类型检验方法的检验效率和应用条件进行讨论,以便能在实际应用中有选择地使用这些方法。

武汉地区胆石症患者胆石与胆汁中微量元素的分析

采用武汉地区胆石症患者胆囊或胆管中的胆石、胆汁及对照组的胆汁,通过原子吸收光谱等方法测定其中18种微量元素的含量。结果发现不同部位结石中的这些微量元素平均含量除铬外均无显著性差异,结石中12种微量元素的含量高于其胆汁中的含量;7种微量元素(铅、钙、砷。、铬、锰、铁、铝)高于对照组中的含量(P均<0.05)。胆石症患者胆汁中钠、钾、铜、铝、镁的平均含量均低于对照组(P<0.05),其它微量元素平均含量与对照组比较差异无显著性意义,本结果对进一步研究结石形成机理与防治措施提供了依据。

鱼类肠肾虫一新种

<正> 1986年6月,作者在四川涪陵的中华倒刺鲃(Barbodes sinensis Bleeker)后肠检获一种纤毛虫,根据虫体的特征及前人的分类方法,鉴定为斜口科(Plagiotomidae),肠肾虫属(Nyctotherus)一新种,定名为长江肠肾虫(Nyctotherus changjiangensis sp.nov.) 寄生虫的形态研究,除活体观察外,均采用纤毛虫常规涂片染色方法观察。测量了10个以上标本,测量单位为微米。模式标本保存于中国科学院水生生物研究所鱼病室。长江肠肾虫(新种)Nyct

白鱀豚饲养池水质状况的研究

<正> 白鱀豚是我国特有的稀珍水生哺乳动物。仅分布于长江的中、下游干流之中。关于如何饲养白鱀豚没有可借鉴的资料。在没有水净化装置和流水系统的条件下,为了既能节省人力和财力,又能保证豚体的健康,我们对白鱀豚饲养池的理化和微生物因子进行了系统、全面的测定和研究。

兴修水利枢纽后汉江产漂流性卵鱼类的繁殖生态

1.汉江产漂流性卵的鱼类至少有25种,其中经济鱼类有草鱼、青鱼、鲢、鳙、鯮、鳤、鳡、长春鳊、赤眼鳟、铜鱼、吻鮈、鳜以及三种红鲌属鱼类。2.产漂流性卵鱼类开始产卵的水温分别在16—20℃之间,经济鱼类多在18℃上下。产卵时需要有江河的涨水过程。在河流涨水的诸水文要素中,流速的增大,对促使产卵起着主要作用。不同的鱼类产卵时对流水的要求是有差异的。鱼类的产卵规模与江水的流速增大紧密相关。3.丹江水库建成后,上游的产卵场有前房、天河口和安康等10处。中游有钟祥和马良等7处,支流唐河、白河也有产卵场。就总产卵量来看

武汉东湖湖泊地质(第四纪)研究——有关东湖成因和古云梦泽问题的讨论

<正> 东湖位于武汉市武昌区东北,形若一斜放的等腰三角形,面积在水位20.5米时为27.899平方公里,平均水深2.21米,流域面积187平方公里。东湖是长江中下游的一个中型浅水湖泊。 湖之南,两列东西向残丘(以瑜家山最高,151.84米),互相平行,断续相连。这两列残丘皆为泥盆系石英砂岩所组成的向斜山,它们之间为志留系页岩所组成的背斜谷地,表