抑制肠道气呼吸大鳞副泥鳅主要呼吸器官的组织病理

为了阐明肠道气呼吸对泥鳅的生理作用,本研究通过抑制大鳞副泥鳅肠道气呼吸,探究其主要呼吸器官的组织病理变化。结果显示,被抑制肠道气呼吸的大鳞副泥鳅通常在1周左右死亡。当被抑制肠道气呼吸的大鳞副泥鳅出现垂死时,采集对照组和实验组的鳃、皮肤、前肠、中肠、后肠以及直肠进行苏木素—伊红(H.E)染色、阿利新蓝—高碘酸雪夫氏(AB-PAS)染色组织切片观察和扫描电镜观察,主要的病理变化:①H.E染色结果显示实验组大鳞副泥鳅鳃丝末端充血,背部皮肤表皮层的毛细血管收缩并减少,且真皮层细胞呈畸形,前肠黏膜褶膨大,后肠浆膜层有血红细胞渗出,后肠、直肠结缔组织显著增厚;②AB-PAS染色结果显示,实验组大鳞副泥鳅鳃、背部皮肤、后肠、直肠组织中嗜酸性空泡细胞均增多,前肠和中肠固有层酸性黏蛋白含量增多,黏膜下层中性黏蛋白含量减少;③扫描电镜结果显示,实验组大鳞副泥鳅鳃丝鳃小片表面皱缩,表皮受损脱落,背部皮肤表面分泌孔增加,中肠内腔表面突起增多,后肠和直肠絮状颗粒增多。研究表明,抑制大鳞副泥鳅肠道气呼吸会引发其主要呼吸器官上皮组织出现黏液细胞增多、血红细胞溢出等病理变化,甚至导致机体死亡,由此可知,肠道气呼吸行为...     

An analysis of the persistence and potency of film‐coated seed protectant as influenced by various storage parameters

BACKGROUND: An efficient delivery system for seed‐protectant chemicals is needed in light of several disadvantages of conventional seed treatment methods. This study evaluates the efficacy of film‐coat application in maintaining the persistence and potency of imidacloprid on Lycopersicon esculentum (L.) Mill. seeds after simultaneous storage under ambient and regulated environment in paper and aluminium packages. RESULTS: High‐performance liquid chromatography (HPLC) revealed 0.135 mg kg^?1 of herbage material to be the threshold value beyond which absolute control was obtained, and with film coating the latter was achieved even with half‐dosage seed treatment, irrespective of the storage condition. The technique provided early protection to the crop and also nullified the deleterious effects of ambient storage on the persistence and potency of the pesticide. CONCLUSION: Film coating enabled superior pesticide dosage as well as higher biological efficacy to be achieved. Hence, in addition to being an ecofriendly alternative, the technique would be a more economically viable option for storage of treated seeds. Copyright © 2009 Society of Chemical Industry     

Indirect myosin immunocytochemistry for the identification of fibre types in equine skeletal muscle.

The histochemical ATPase method for muscle fibre typing was first described by Brooke and Kaiser in 1970. However, problems have been found with the subdivision of type II fibres using this technique. To determine whether indirect myosin immunocytochemistry using anti-slow (5-4D), anti-fast (1A10) and anti-fast red (5-2B) monoclonal antibodies with cross reactivity for type I, II and IIa fibres, respectively, in a number of species, could identify three fibre types in equine skeletal muscle, data on fibre type composition and fibre size obtained using the two different techniques were compared. Results indicate that different myosin heavy chains can coexist in single equine muscle fibres. Type I and type II fibres were identified by immunocytochemistry, but subdivision of type II fibres was not possible. Although the percentage of type I and type II fibres was not significantly different for the two techniques, a few fibres reacted with both the 1A10 and 5-4D antibodies.     

Comparative performance of four multi-purpose trees associated with four grass species in the humid regions of Southern India

The results of a field trial conducted at the Livestock Research Station, Thiruvazhamkunnu, Kerala to study the compatibility of different components in a silvo-pastoral system revealed that growth and yield of fodder species were significantly influenced by the tree components only after tree canopy formation. The fodder species such as Pennisetum purpureum Schum., Panicum maximum Jacq., Brachiaria ruziziensis Griseb. and Euchlaena mexicana Schrad. grown in association with Casuarina equisetifolia J. R. & G. Forst. and Ailanthus malabarica DC recorded comparatively higher forage yield even after canopy formation. However, forage crops grown in combination with Acacia auriculiformis A. Cunn. ex Benth. and Leucaena leucocephala (Lam.) de Wit. registered relatively lower values for growth and yield. Increased light infiltration into the understorey due to the cladophyllous canopy can be attributed as reason for the higher fodder productivity under Casuarina. Due to the combination of crown size and shape, tree height and spacing the amount of light intercepted by Ailanthus also was very low. Among the four multi-purpose trees used, Acacia recorded the maximum growth rate followed by Casuarina, Ailanthus and Leucaena. Forage productivity of the four species was in the order: Pennisetum purpureum > Panicum maximum > Brachiaria ruziziensis > Euchlaena mexicana. Casuarina with Pennisetum/ Panicm were found to be optimal tree — forage combinations for silvo-pastoral systems.     

Antimicrobial activity of saponins from Acacia auriculiformis

Acaciaside A and B, two acylated bisglycoside saponins originally isolated from the funicles of Acacia auriculiformis, are known to have antihelminthic activity. Their antifungal and antibacterial activities were investigated. Complete inhibition of conidial germination of Aspergillus ochraceous and Curvularia lunata was recorded at 300 microg/ml or less whereas to inhibit the growth of Bacillus megaterium, Salmonella typhimurium and Pseudomonas aeruginosa 700 microg/ml or higher concentrations of the mixture was required. Two catabolic enzymes, phosphofructokinase and isocitrate dehydrogenase, responded differentially in fungi and bacteria against sublethal concentrations of the compound when assayed from their cell free extracts. An increased specific activity of the enzymes in bacteria and a decrease activity in fungi indicate a possible different mechanism of inhibition of saponins on the organisms tested.     

Doubled haploids in tropical maize: <Emphasis Type="SmallCaps">II</Emphasis>. Quantitative genetic parameters for testcross performance

Single crosses (SC) of elite inbreds and open-pollinated populations (OP) are suitable source germplasm for doubled haploid (DH) line development in hybrid maize breeding, given that they combine a high population mean ([`(x)] \overline{x} ) for testcross performance with adequate response to selection ( \Updelta G \Updelta G ). This is the first study reporting testcross grain yield (TCGY) and dry matter content (TCDMC) evaluations of 131 DH lines developed from ten tropical source germplasm comprising five OP (OP1–OP5) and five SC (SC1–SC5). Gene diversity (d) and the average number of alleles (a <sub>r</sub> ) per locus was estimated for DH lines based on 24 simple sequence repeat markers. Analysis across three environments revealed no significant differences between [`(x)] \overline{x} of OP- and SC-derived DH lines for TCGY and TCDMC. Significant genetic variance for both traits was only detected among OP-derived DH lines which may be explained by a larger number of segregating quantitative trait loci (QTL) as suggested by higher d and a _r values than in SC-derived DH lines. The usefulness criterion ( U = [`(x)] + \Updelta G U = \overline{x} + \Updelta G ) was higher for OP-derived DH lines for TCDMC, but higher for SC-derived DH lines for TCGY. DH lines from OP1, OP2, and OP3 showed high TCGY, suggesting that they may be useful in tropical hybrid breeding. We conclude that tropical OP represent a valuable source of untapped genetic variation that can efficiently be exploited with DH technology for hybrid maize breeding.     

Phytate and phytase in fish nutrition

Phytate formed during maturation of plant seeds and grains is a common constituent of plant-derived fish feed. Phytate-bound phosphorus (P) is not available to gastric or agastric fish. A major concern about the presence of phytate in the aquafeed is its negative effect on growth performance, nutrient and energy utilization, and mineral uptake. Bound phytate-P, can be effectively converted to available-P by phytase. During the last decade, phytase has been used by aqua feed industries to enhance the growth performance, nutrient utilization and bioavailability of macro and micro minerals in fish and also to reduce the P pollution into the aquatic environment. Phytase activity is highly dependent on the pH of the fish gut. Unlike mammals, fish are either gastric or agastric, and hence, the action of dietary phytase varies from species to species. In comparison to poultry and swine production, the use of phytase in fish feed is still in an unproven stage. This review discusses effects of phytate on fish, dephytinisation processes, phytase and pathway for phytate degradation, phytase production systems, mode of phytase application, bioefficacy of phytase, effects of phytase on growth performance, nutrient utilization and aquatic environment pollution, and optimum dosage of phytase in fish diets.     

Germany/Australia Index of Sperm Sex Sortability in Elephants and Rhinoceros

Flow cytometric sexing of spermatozoa followed by application in artificial insemination or in vitro fertilization provides a unique opportunity to predetermine the sex of offspring and might enhance the conservation management of endangered species in captivity such as the elephant and rhinoceros. To obtain an indication of the sortability of spermatozoa from these species, the relative DNA differences between X and Y chromosome bearing spermatozoa (fresh, frozen thawed, epididymal) from three rhinoceros species [white ( Ceratotherium simum ), black ( Diceros bicornis ), Indian ( Rhinoceros unicornis )] and both elephant species, the Asian and the African elephant ( Elephas maximus, Loxodonta Africana ), were determined through separation of spermatozoa into X and Y chromosome bearing populations, using a modified high speed flow cytometer. The head profile areas of spermatozoa from all five species were measured using light microscopy. By multiplying the relative DNA differences and the head profile areas, the sperm sorting indices were calculated to be 47, 48 and 51 for white, black and Indian rhinoceros respectively. The calculated sorting index for the Asian elephant was 66. In the African elephant, we determined the highest sorting index of 76. These results indicate the practicability of flow cytometric sex sorting of spermatozoa from the tested rhinoceros species and both elephant species. The lower sorting indices in rhinos indicate that sex sorting of spermatozoa from the rhinoceros will be more challenging than in elephants.     

Removal of Fatty Acids from Palm Oil Effluent by Combined Electro-Fenton and Biological Oxidation Process

The objective of this paper is to design a pilot plant electrochemical reactor and to prove the operational concept of the electrochemical production of ferrate in situ and its online application for sewage treatment. To that end, the first part of this paper focuses on the analysis of the main engineering aspects of the reactor and the electrochemical process that affect the ferrate production, using laboratory scale experiments such as the interelectrode gap, the space-time yield, the area/volume (A/V) ratio, the current efficiency, and the energy consumption. The second part focuses on the production of ferrate using a pilot plant scale to prove the operational concept of the electrochemical generation of ferrate in situ and its online application as a step towards its full scale application for water and wastewater treatment.