Distinct monoamine oxidase A and B populations in primate brain

Monoclonal antibodies specific for monoamine oxidase (MAO) A and MAO B, respectively, were used to localize these enzymes in primate brain. The reagents recognized different populations of neurons: those that recognized MAO A were located in cell groups containing catecholamines, including the substantia nigra, nucleus locus coeruleus, nucleus subcoeruleus, and the periventricular region of the hypothalamus, whereas those that recognized MAO B were observed in serotonin regions, including the nucleus raphe dorsalis and nucleus centralis superior. These data illustrate the physiological independence of MAO A and B and show that neurons may be specialized for their degradative as well as their synthetic functions.     

用cDNA微阵列分析水稻防卫反应及信号传导相关基因

应用cDNA微阵列技术分析了水稻受白叶枯菌侵染后一对近等基因系(中早14R、9S)的防卫信号传导途径.在mRNA 水平,对检测到的相关基因(如病程相关蛋白、信号传导、转录因子等)间相互作用及信号传导途径的分析结果表明:白叶枯菌侵染下,乙烯(ET)介导的信号传导途径在防卫反应中可能起着重要作用.核基因接受信号后改变了一些防卫反应相关基因的表达水平,来应答病原物的侵入.实验结果还提示,水稻的一些基因通过表达丰度的改变对乙烯信号途径产生反馈调节.     

稻褐飞虱对噻嗪酮抗性的检测技术

建立了适合于测定褐飞虱对噻嗪酮敏感性的稻茎浸渍法及相对敏感毒力基线。用该方法检测的结果表明：１９９６年安庆、江浦,１９９７年南宁种群对噻嗪酮为早期抗性（抗性倍数为３．０￣３．５）;１９９６年由南向北敏感性有下降趋势,而１９９７年该趋势不明显。还对抗性监测方法及抗生治理进行了讨论。     

新内标法在斑蝥素测定中的应用研究

研究了香兰素、正十六烷等物质和样品组分的气相色谱行为,观察这些物质与斑蝥素的分离情况以及样品组分对测定的干扰情况。结果表明,正十六烷与斑蝥素的分离十分理想（分离度〉2．5）;用正十六烷做内标的气相色谱法的线型（r=0．9991）和精密度（RSD=3．07％,n=6）较好;样品组分对测定无干扰。新内标法简便,结果准确。可作斑蝥及斑蝥素制品中斑蝥素含量的精确测定之用。     

Social components of fitness in primate groups

There is much interest in the evolutionary forces that favored the evolution of large brains in the primate order. The social brain hypothesis posits that selection has favored larger brains and more complex cognitive capacities as a means to cope with the challenges of social life. The hypothesis is supported by evidence that shows that group size is linked to various measures of brain size. But it has not been clear how cognitive complexity confers fitness advantages on individuals. Research in the field and laboratory shows that sophisticated social cognition underlies social behavior in primate groups. Moreover, a growing body of evidence suggests that the quality of social relationships has measurable fitness consequences for individuals.     

A functional protein chip for pathway optimization and in vitro metabolic engineering

Pathway optimization is difficult to achieve owing to complex, nonlinear, and largely unknown interactions of enzymes, regulators, and metabolites. We report a pathway reconstruction using RNA display-derived messenger RNA-enzyme fusion molecules. These chimeras are immobilized by hybridization of their messenger RNA end with homologous capture DNA spotted on a substrate surface. Enzymes thus immobilized retain activity proportional to the amount of capture DNA, allowing modulation of the relative activity of pathway enzymes. Entire pathways can thus be reconstructed and optimized in vitro from genomic information. We provide concept validation with the sequential reactions catalyzed by luciferase and nucleoside diphosphate kinase and further illustrate this method with the optimization of the five-step pathway for trehalose synthesis.     

Eye and head movements in peripheral vision: nature of compensatory eye movements

Simultaneous recordings of both eye and head movements in response to a peripheral signal indicated that the backward compensatory eye movement was initiated during the constant velocity of the head rotation. This compensatory movement began before the eyes had actually reached the peripheral signal.     

A plant based sensing method for nutrition stress monitoring

Due to economical and ecological reasons it is important to provide the necessary flexibility in fertilizer management to respond to differences in plant nutrients requirements. Plant-based sensors have potential to provide more accurate and on-line information regarding crop bio-responses to environmental stress and could overcome limitations of traditional methods which focus only on monitoring parameters of soil. Current research regarding on-line plant stress sensing techniques concentrates on spectroscopic and image processing methods. These techniques have many limitations connected with their sensitivity to environmental interferences. In recent years, impedance spectroscopy has become a well-known non-invasive tool for describing the electrical properties of many systems. The research hypothesis tested was that information provided by Electrical Impedance Spectroscopy is correlated with tomato plant stress caused by lack of mineral nutrients in the growth medium. The experiment was conducted with two sets of hydroponically-grown tomato plants (Lycopersicon esculentum Mill., cv. ‘Maliniak’). During the experiment the tomato plants were fed alternately with flow of necessary nutrients and with distilled water. The impedance spectra were measured by scanning frequencies from 100 Hz to 50 kHz to determine the most sensitive frequency. A Nutrition Index was proposed for indicating variability of mineral nutrition within plants, and its correlation with experimental plant data was tested. Data showed that the relation between the Nutrition Index and the stress caused by lack of mineral nutrients in the growing medium was a monotonic function in the case of study. The results presented in the paper support the concept that the electrical impedance spectroscopy is a non-destructive, economical and reliable measurement method, which can be utilised for plant nutrition stress monitoring.     

Neuroscience. A critical issue for the brain

The notion that there is a "critical period" for learning in the first 3 years of life has cropped up widely in media reports recently. But although critical periods have been well documented for the development of sensory systems in the brain, especially vision, researchers differ over whether they exist for the development of the brain functions that underlie complex learning and thinking skills. Scientists do agree, however, that where critical periods do exist, they are not sharply defined, nor are they unique to the first 3 years of life, as has been conveyed in the media. The message should give hope to adults who may not learn with the ease of early childhood, but can still do it.     

Neural basis of orientation perception in primate vision

Orientational differences in human visual acuity can be related parametrically to the distribution of optimal orientations for the receptive fields of neurons in the striate cortex of the rhesus monkey. Both behavioral measures of acuity and the distribution of receptive fields exhibit maximums for stimuli horizontal or vertical relative to the retina; the effect diminishes with distance from the fovea. The anisotropy in the neuronal population and in visual acuity appear to be determined by postnatal visual experience.     

Methodological challenges in the study of primate cognition

Laboratory studies of primate cognition face the problem that captive populations of a species are not always comparable, and generalizations to natural populations are never certain. Studies of primate cognition in the field face the problem that replications are expensive and difficult, and again different populations are not always comparable. To help remedy these problems, we recommend the creation of data banks where primary data and videotapes may be deposited (perhaps as a requirement of publication) to facilitate cross-examination, replication, and, eventually, the pooling of data across investigators.     

A solar-powered wireless cell for dynamically monitoring soil water content

In various agricultural activities, such as irrigation scheduling, tillage operation and nutrient management, soil water content is regarded as an essential parameter. For the demand of monitoring soil water dynamics at field scale, this study presents a solar-powered wireless cell that contained a water content sensor, two temperature sensors, an optical sensor, a communication module and a data-logger. To evaluate its feasibility in the field, three cells were independently installed in a bare plot, a maize plot and a sugarbeet plot in the summer of 2008. By a heavy rain event (20 mm, 6 h) during the experimental period, different responses of soil water content sensors were dynamically recorded and then analyzed under each canopy condition. In addition, to explore the possibility of reducing the dimensions of the cell under the condition of sufficient energy supply, various sizes of the solar panel were tested. The experimental results showed that the cell is promising to become a node of wireless network in the field.     

玉米精播机排种监测报警装置

充分考虑田间作业条件，开发了基于数字集成电路的4行玉米精播机排种监测报警装置。从电路功能上解决了报警逻辑、时间选择、监测行设置等问题；考虑田间作业环境，设计了具有防雨性能的传感器外壳、传感器在排种通路的安装结构、与主机的连接方式以及整个装置的供电方案等。设计了具有突出抗尘性能的传感器。田间使用结果表明，该装置能够适应田间工作环境，可取代农机手实现可靠监测报警。     

A light-weight multi-spectral aerial imaging system for nitrogen crop monitoring

Image-based remote sensing is one promising technique for precision crop management. In this study, the use of an ultra light aircraft (ULA) equipped with broadband imaging sensors based on commercial digital cameras was investigated to characterize crop nitrogen status in cases of combined nitrogen and water stress. The acquisition system was composed of two Canon^? EOS 400D digital cameras: an original RGB camera measuring luminance in the Red, Green and Blue spectral bands, and a modified camera equipped with an external band-pass filter measuring luminance in the near-infrared. A 5?month experiment was conducted on a sugarcane (Saccharum officinarum) trial consisting of three replicates. In each replicate, two sugarcane cultivars were grown with two levels of water input (rainfed/irrigated) and three levels of nitrogen (0, 65 and 130?kg/ha). Six ULA flights, coupled with ground crop measurements, took place during the experiment. For nitrogen status characterisation, three indices were tested from the closed canopy: the normalised difference vegetation index (NDVI), the green normalised difference vegetation index (GNDVI), and a broadband version of the simple ratio pigment index (hereafter referred to as the SRPI_b), calculated from the ratio between blue and red bands of the digital camera. The indices were compared with two nitrogen crop variables: leaf nitrogen content (N_L) and canopy nitrogen content (N_C). SRPI_b showed the best correlation (R ²?=?0.7) with N_L, independently of the water and the N treatment. NDVI and GNDVI were best correlated with N_C values with correlation coefficients of 0.7 and 0.64 respectively, but the regression coefficients were dependent on the water and N treatment. These results showed that SRPI_b could characterise the nitrogen status of sugarcane crop, even in the case of combined stress, and that such acquisition systems are promising for crop nitrogen monitoring.     

Brain stem neurons in modified pathways for motor learning in the primate vestibulo-ocular reflex

The vestibulo-ocular reflex (VOR) stabilizes retinal images by generating smooth eye movements that are equal in amplitude and opposite in direction to head turns. Whenever image motion occurs persistently during head turns, the VOR undergoes motor learning; as a result image stability is gradually restored. A group of brain stem neurons that are in the modified pathways has now been described. The neurons express changes in firing in association with motor learning in the VOR and receive monosynaptic inhibition from the flocculus of the cerebellum. The changes in firing have an appropriate magnitude and are expressed at the correct latency to account for the altered VOR. The response properties of the neurons point to their brain stem vestibular inputs for further investigation of the site of motor learning.