Spectroscopic Studies of the Interaction of Eu(III) with the Roots of Water Hyacinth

The water hyacinth is a plant currentlybeing used throughout the world, including siteswithin 1 km of the Chernobyl nuclear accident, for theremoval of toxic metals from water. We have recentlyshown that the roots of water hyacinth will removelarge quantities of Eu(III) from water. In this studywe were able to determine that carboxylic acids areresponsible for binding the intracellular proportionof Eu(III) in the roots of water hyacinth using thetechniques of Nuclear Magnetic Resonance (NMR) andInfrared (IR) spectroscopies.     

A comparison of the interferon gamma assay with the absorbed ELISA for the diagnosis of Johne''s disease in cattle

Two interferon gamma (IFN-gamma) assays, the IFN-gamma enzyme immunoassay (EIA) and the IFN-gamma bioassay and an absorbed ELISA were used to screen 6 cattle herds for Johne's disease. Each herd had a history of Johne's disease but the majority of infected animals did not show clinical signs. The disease status of the cattle, which were removed from the herds, was confirmed by bacteriological culture of faeces or histopathological examination and culture of tissues collected at necropsy. The sensitivities of the IFN-gamma assays and the absorbed ELISA were determined using test results from infected animals. The sensitivity of the IFN-gamma EIA in detecting subclinical (71.8 to 93.3%) and clinical animals (100%) was not significantly different. However, the IFN-gamma bioassay and the absorbed ELISA were more sensitive in detecting cattle with advanced infections (80%) than those that were subclinically affected (16.7 to 33.3%).     

Responses of the reproductive vascular system during the egg‐formation cycle of unanaesthetised laying hens

1. Vascular adjustments to the process of egg formation were examined in the unanaesthetised laying hen, by the radioactive microspheres method.

2. Three‐ to four‐fold increases in blood flow were found in segments surrounding the egg during its passage along the oviduct, possibly due to an enhanced metabolic activity in the muscle layer of the oviduct.

3. Shell‐gland blood flow was minimal in the absence of an egg and increased gradually to a maximum (5‐fold) about 5 h after entrance of the egg into the shell gland. This parallels the rate of calcification of the egg shell.

4. Changes in blood flow in the ovarian follicles and other parts of the oviduct were small while the egg was in the shell gland. This might be typical for the reproductive system of the fowl, which undergoes little structural alteration during egg formation.     

The thermoneutral temperature zone and seasonal acclimatisation in the hen

1. Oxygen consumption, body temperature, respiratory frequency and respiratory water loss of White Leghorn x Rhode Island hens were measured for short periods at six air temperatures between 2 and 32 °C. The hens were kept between tests in an open shed. The experiments were carried out over 3 years.

2. The upper critical temperature (Tcu) was estimated by the air temperature at which: 1, respiratory frequency increased above 60 respirations/min and 2, body temperature increased by 0.3 °C above that at the lower critical temperature. These responses to the test temperatures were examined as a function of the. acclimatisation temperature (Ta) represented by the mean daily temperature during experimental periods.

3. A seasonal change in Tcu was observed, which correlated with Ta(r = 0.836). The seasonal 10 °C change in the Ta brought about a 3 °C change in Tcu, compared with an 8.5 °C change in the lower critical temperature.

4. Thermoneutral temperature zone decreased with increasing Ta; the two critical temperatures tended to merge at a Ta of 32 °C. The latter probably represents an upper limit for acclimatisation to heat.     

大豆遗传资源保护的法律法规及其可专利性

大豆起源于中国,中国是世界上大豆遗传资源最为丰富的国家,也曾经是世界上最主要的大豆生产国和出口国。半个多世纪以来,科学技术的进步带动了一些美洲国家大豆产业的迅猛发展,中国的大豆生产量由世界首位降到美国、巴西之后,从大豆出口国变为大豆净进口国,大豆成为中国农产品贸易中最令国际社会关心的贸易作物。随着农业生物技术的快速发展,知识产权保护的法律法规的国际化,尤其是我国加入WTO以后,大豆研究、开发、生产领域遇到了来自比其他作物前所未有的挑战。作为我国最重要的植物蛋白、食用油及动物饲料来源的大豆作物,有效地利用有关的法律法规保护我国大豆种质资源及新品种已经迫在眉睫。本文着重介绍了与大豆遗传资源、新品种保护相关的我国法律法规,进行了大豆保护的可专利性分析,并对大豆研发过程中的知识产权保护问题作了初步探讨,以促进对大豆新品种的申请保护,提高我国应对来自国外竞争的抗衡能力。     

Development of a robotic detection system for greenhouse pepper plant diseases

Automation of disease detection and monitoring can facilitate targeted and timely disease control, which can lead to increased yield, improved crop quality and reduction in the quantity of applied pesticides. Further advantages are reduced production costs, reduced exposure to pesticides for farm workers and inspectors and increased sustainability. Symptoms are unique for each disease and crop, and each plant may suffer from multiple threats. Thus, a dedicated integrated disease-detection system and algorithms are required. The development of such a robotic detection system for two major threats of bell pepper plants: powdery mildew (PM) and Tomato spotted wilt virus (TSWV), is presented. Detection algorithms were developed based on principal component analysis using RGB and multispectral NIR-R-G sensors. High accuracy was obtained for pixel classification as diseased or healthy, for both diseases, using RGB imagery (PM: 95%, TSWV: 90%). NIR-R-G multispectral imagery yielded low classification accuracy (PM: 80%, TSWV: 61%). Accordingly, the final sensing apparatus was composed of a RGB sensor and a single-laser-beam distance sensor. A relatively fast cycle time (average 26.7 s per plant) operation cycle for detection of the two diseases was developed and tested. The cycle time was mainly influenced by sub-tasks requiring motion of the manipulator. Among these tasks, the most demanding were the determination of the required detection position and orientation. The time for task completion may be reduced by increasing the robotic work volume and by improving the algorithm for determining position and orientation.