Jellyfish uses jet propulsion to achieve a diversity of propulsion modes in the water. In this article, a miniature jellyfish-inspired swimming robot is designed and built, which is capable of executing horizontal and vertical propulsion and maneuvers. In order to imitate the jellyfish in terms of morphology and kinematics, the robotic jellyfish is designed to be comprised of a streamlined head, a cavity shell, four separate drive units with bevel gears, and a soft outer skin encasing the drive units. A combination of four six-bar linkage mechanisms that are centrally symmetric is adopted as the driver to regulate the phases of contraction and relaxation of the bell-shaped body. Furthermore, a triangle wave generator is incorporated to generate rhythmic drive signals, which is implemented on the microcontroller. Through independent and coordinated control of the four drive units, the robotic jellyfish is able to replicate various propulsion modes similar to real jellyfish. Aquatic tests on the actual robot verify the effectiveness of the formed design scheme along with the proposed control methods.

Bio-inspired robotic fish hold strong promise for underwater missions. This paper deals with the design and control issues of a miniature free-swimming robotic fish with multiple sensors. Specifically, a synthesized mechanical design scheme mainly relying on a two-link serial mechanism and a pair of mechanical pectoral fins is first presented. Next, a bio-inspired Central Pattern Generator (CPG) based control method aided by feedback information from multiple sensors of various types to achieve three-dimensional swimming is proposed. Finally, experimental results on the 35-centimetre-long robotic fish verify the efficacy of the proposed mechatronic design and control methods. It is found that the CPG control combined with sensory information greatly contributes to swimming ability and intelligence of the robotic fish.

This paper addresses the system design and locomotion control for a versatile amphibious robot, AmphiRobot-II, inspired by various amphibian principles in the animal kingdom. In terms of the propulsion features of existing amphibians, a novel hybrid propulsive mechanism coupled with wheel-propeller-fin movements is proposed that integrates fish- or dolphin-like swimming and wheel-based crawling. The robot is able not only to implement flexible wheel-based movements on land, but also to perform steady and efficient fish- or dolphin-like swimming under water and can further switch between these two patterns via a specialized swivel device. To achieve multimodal motions, a body deformation steering approach is proposed for the turning locomotion on land with minimum turning radius obtained accordingly. A central pattern generator inspired underwater locomotion control is also implemented and tested on the physical robot. Based on the aforementioned design, the AmphiRobot-II prototype has been built and has successfully demonstrated to confirm the effectiveness of the hybrid propulsive scheme and the amphibious control approaches.

The alteration of ultrastructure in Pisum sativum and Vicia faba leaf cells infected with B935 isolate of BBWV 2 were investigated by electron microscopy, immunogold-labeling technique. The results showed that the membranous proliferation, virus-formed crystals and tubular structures were found in leaf cells of two hosts. At early stages of infection, the tubules containing virus-like particles associate with plasmodesmata in mesophyll cell. Immunogold particles anti-BBWV 2 were localized to the plasmodesmata modified by tubules passing through them. The membranous proliferation and virus-formed tubules were also found in the parenchyma cells, companion cells and transfer cells of vascular bundle. Some virus-like particles located within sieve tube can be labeled immunogold particles anti-BBWV 2. These suggest that BBWV 2, similar CPMV, produce tubules extending into the plasmodesmata. Virions assembled in the cytoplasm are escorted to the tubular structures through interactions with their MP and are then transported to the adjacent cell. Many 160 nm in diameter virus-formed tubules in the cytoplasm, as a special aggregate, not directly relate to cell-to-cell movement; Intact virions are long-distance sustemic transported possibly through sieve elements.

Cellular localization of Rubisco and Rubisco activase(RCA) in pea (Pisum sativum L.) and broad (Vicia faba L.) leaves were investigated by immunogold-labeling electron microscopy. The results showed that the leaf anatomy and the chloroplast ultrastructure were extremely similar between pea and broad. Their mesophyll chloroplasts had well-developed grana and the stroma was densely labeled with immunogold particles for Rubisco and for RCA. The two photosynthetic enzymes were mainly located in chloroplasts of mesophyll and guard cell of stomatal apparatus. In contrast, there was no specific binding of gold particles detected in the cytoplasm, vacuole, mitochondria and other organelles. These results showed that the structure and function of chloroplasts are similar in C_3 plants.

<正>植物病毒侵入寄主后在细胞中复制增殖,通过胞间连丝短距离胞间运动和维管束长距离转运到达植株各个部位,形成系统性侵染。以烟草花叶病毒(TMV)为代表的运动蛋白MP/RNA结合体形式和以豇豆花叶病毒(CPMV)为代表的管状结构形式是2种最主要的胞间运动形式。有关蚕豆萎焉病毒2(Broad bean wilt virus 2,BBMV 2)所在蚕豆病毒属(Fabavirus)的胞间运动机理迄今尚不明了。对BBWV 2中国分离物B935侵染的豌豆和蚕豆进行了详细的超微结构观察,得到了一些涉及病毒胞间运动和长距离转运的超微结构证据。

蚕豆萎蔫病毒2(Broad bean wilt virus 2,BBWV2)是侵染我国豆科作物、蔬菜作物、花卉、烟草、中草药及一些木本植物的重要病毒病原,我们在研究该病毒侵染寄主的分子细胞学特征及病毒胞间运动过程中发现,BBWV 2中国分离物B935侵染的豌豆叶细胞中线粒体大量增生聚集、形状改变、产生类结晶包涵体等异常变化,从病毒的体内复制过程与线粒体变化动态来分析,可能与病毒的组装有关.

The alteration of mitochondrion in Pisum sativum leaf cells infected with B935,isolates of BBWV 2, were investigated by electron microscopy, immunogold-labeling technique and stereologic quantity. The results showed that mitochondria were hyperplastic and aggregated nearby the membranous proliferation in cytoplasm. Many mitochondria were enlarged and distorted. There are some square paracrystalline inclusions within abnormal mitochondria. The difference between infected and healthy leaf cells at mitochondrion was observed to reveal significances in volume density (V(V)), surface density (S(V)), numerical density (Nv)(P < 0.01), but it was varied in form factor (PE), circumference index (CI), ratio of surface to volume (R(SV)). Some immunogold particles were localized to the crystal substance between the mitochondria. A high density of immunogold particles were localized to the crystalline aggregates and tubules composed of virus particles. This indicated that hyperplasia and aggregation of mitochondrion related to the assembly of virion in infection cells. BBWV 2 particles were assembled at the position of adherent mitochondria. The paracrystalline inclusions within mitochondria could represent the accumulation of a certain protein.

The cellular localizations of Rubisco and Rubisco activase (RCA) in Chinese cabbage (Brassica chinensis L. cv. Suzhou) leaves were investigated by immunogold-labeling electron microscopy. The results showed that Rubisco and RCA were mainly located in chloroplasts of mesophyll, guard cell of stomatal apparatus and parenchyma of vascular bundle. A high density of gold particles were localized preferentially to the chloroplast stroma. In contrast, there were no specific binding of gold particles detected in the cytoplasm, vacuole, mitochondria and other organelles. As infected by turnip mosaic virus, the density of gold particles decreased lightly in the abnormal chloroplasts and dropped by much lower (58.44% and 64.67% as that in the health chloroplasts respectively) in swollen chloroplasts. This indicated that virus infection caused the decreases of Rubisco and RCA in host plant, which then affected plant photosynthesis.

Cellular localization of Rubisco and Rubisco activase (RCA) in the C(3) plant barley (Hordeum vulgare L.) and the C(4) plant maize (Zea mays L.) leaves was investigated using immunogold-labeling electron microscopy. The results showed that the leaf anatomy and the immunolocalization of the two photosynthetic enzymes were markedly different between barley and maize. In barley, the mesophyll chloroplasts had well-developed grana and their stroma was densely labeled with immunogold particles for Rubisco and for RCA. In maize, the mesophyll chloroplasts had well-developed grana but their stroma was scarcely labeled with immunogold particles, indicating a low Rubisco content. But the chloroplasts of the bundle sheath cells had only few rudimentary grana and their stroma was densely labeled with immunogold particles for Rubisco. A higher density of immunogold particles for RCA was located both in chloroplast stroma of the bundle sheath cells and the mesophyll cells. These results showed that the structure and function of chloroplasts are different between C(3) plants and C(4) plants.

Rubisco(1,5-二磷酸核酮糖羧化酶/加氧酶)是植物进行光合碳同化的关键酶,它参与了光合作用碳固定和光呼吸碳氧化过程,调节两者之间的相对比例,其含量和活性与光合速率密切相关.RCA(Rubisco活化酶)是近年发现的一种可以调节Rubisco活性的酶,能使Rubisco在植株体内条件下达到最大活化程度.有关这两个酶的性质、结构及生理功能已有不少研究,但细胞学定位的报道十分有限,尤其是RCA的细胞定位无论是在低等植物还是高等植物中都很少见.我们运用免疫金标记电镜技术,对几种C3和C4植物进行了Rubisco和RCA细胞学定位研究,明确了C3和C4植物中两种酶在叶绿体内的分布.

The ultrastructural alterations of maize leaves infected with SrMV and SCMV, respectively, were examined under transmission electron microscope. A large number of filamentous SrMV and SCMV particles were observed to be present as scattered or in more or less dense bundles in the cytoplasm of infected cells. Three types of cylindrical inclusions (CIs)-pinwheels, scrolls and laminated aggregates-located in the SCMV-infected cytoplasm, and the similar CIs occurred in the SrMV-infected cytoplasm except for the absence of laminated aggregates. According to Edwardson, SrMV and SCMV were placed in subdivisionⅠand Ⅲ. In this paper, not only cytopathological alterations of maize leaves infected with SrMV and SCMV were compared with each other, but also some cytopathological structures suggestive of cell-to-cell movement were analyzed.