Bioprospection of Microalgae and Cyanobacteria as Biocontrol Agents Against Vibrio campbellii and Their Use in White Shrimp Litopenaeus vannamei Culture     

Oscar González‐Davis  Elizabeth Ponce‐Rivas  M. Del Pilar Sánchez‐Saavedra  María‐Enriqueta Muñoz‐Márquez  William H. Gerwick 《Journal of the World Aquaculture Society》2012,43(3):387-399

Vibrio spp. are the most common and harmful shrimp pathogenic bacteria; however, microalgae and cyanobacteria have the ability to produce antimicrobial substances against these species. In this study, the organic and aqueous extracts of 28 species of marine microalgae and cyanobacteria were screened against Vibrio campbellii M1. Two of these phytoplankton species with antibacterial activity in aqueous extracts (Dunaliella tertiolecta and Skeletonema costatum) and nontoxic to brine shrimp Artemia franciscana nauplii were used to evaluate their anti‐Vibrio effect when used as green‐water cultures in Vibrio‐challenged white shrimp Litopenaeus vannamei cultures. No differences in mortality of juvenile L. vannamei were observed between treatments tested, suggesting that the pathogenicity of V. campbellii could be related to the growth stage of shrimp. The proximal composition of D. tertiolecta and S. costatum was in the recommended range for penaeid shrimp nutrition, allowing shrimp supplemented with these microalgae to have significantly greater total length and weight than control shrimp. Shrimp supplemented with S. costatum presented the highest values of organic mass (11.48 mg/organism) and growth rate (0.31 mg/d) in comparison to D. tertiolecta. These results indicate that microalgae are not only capable of producing antibacterial compounds against Vibrio but can also help shrimp nutrition.  相似文献   

某连续刚构桥的施工阶段结构分析     

慕曦光 《林业科技情报》2012,(1):106-107

随着西部大开发的深入,贵州、广西等山岭地区的道路桥梁等交通建设进入了快速发展时期,而鉴于上述地区山高沟深的特点,高墩大跨连续刚构桥被广泛应用,本文结合工程实例对连续刚构桥的设计理论进行了探讨。  相似文献   

Efficiency of methods applied for goat estrous synchronization in subtropical monsoonal climate zone of Southwest China     

Yongju Zhao  Jiahua Zhang  Hong Wei  Xinming Sun  Biao Mu  Mingju Yu  Lingbing Wang 《Tropical animal health and production》2010,42(6):1257-1262

Two experiments were undertaken to select the efficient method applied for goat estrous synchronization. In experiment 1, a total of 120 does (Capra hircus) were divided into five groups with a randomized block design, and the does of treatment 1 were synchronized by intravaginal sponges impregnated with 30 mg Levonorgestrel inserted for 10 days. Does of treatments 2, 3, and 4 were treated with further injection of 25 IU follicle-stimulating hormone (FSH), 0.05 mg prostaglandin F2 alpha (PGF_2α), and 25 IU FSH + 0.05 mg PGF_2α at sponge withdrawal, respectively. The does in the control group (n = 40) without estrous synchronization treatment and natural estrous does were observed. In experiment 2, a total of 140 does in five goat farms in breeding and non-breeding seasons were treated with the selective efficient procedure. The results presented that all the employed treatments were capable of inducing and synchronizing estrous goats. According to estrous response and economy, the use of intravaginal sponges impregnated with 30 mg Levonorgestrel and 0.05 mg PGF_2α (treatment 3) is the first choice for estrous synchronization, and 95.0% of synchronized does demonstrated estrus, which was significantly higher than that of treatment 1 (P < 0.05) and control group (P < 0.01). The percentages of ovulating of treatments 3 and 4 were the same (95.0%), which were significantly higher than that of treatment 1 (P < 0.01). The ovulation rates among different groups were not significant (P > 0.05). When the selective procedure was applied to five goat farms, 85.7% (120/140) of does demonstrated estrus, and the kidding percentage, litter size, and prolificacy rate were 53.6%, 0.95, and 177%, respectively.  相似文献   

北京杨人工林及其环境系统水分运动,交换和贮存的生理生态学模型   总被引：1，自引：0，他引：1  

穆天民 《林业科学》1990,26(1):9-16

从土壤(S)-植物(P)-大气(A)连续系统的观点出发,在处理1986和1988两年实测数据,确定一批参数和函数关系并建立逻辑结构图的基础上,编制程序用微机对北京杨SPAC系统的水分吸收、贮存、水势和蒸腾等生理生态学指标和土壤含水量的短期(10天)变化做了逐时和逐日预测。结果表明,通过微机实现的短期预测结果能较好地反映实际,各项相对误差一般在8％以下,个别最大的也不超过15％。本模型除理论意义外,还可用于预测苗圃地10天内土壤水分的变化,有助于指导灌溉实践。  相似文献   

关于新疆1∶100万农业地貌区划问题的讨论     

乔木  陈模 《干旱区研究》1995,12(2):54-57

根据新疆同一地貌区域形态成因，水热及农业发展方向和改造利用条件的相似性或不同地貌区间的差异性原则，建立起构造、新构造运动、外力作用，地貌形态等农业区划樗，以及农业地貌各级区域标志。  相似文献   

中华通草蛉雄性生殖系统的解剖学研究     

陈天业  牟吉元 《昆虫天敌》1995,17(4):165-166

本文报道中华通草蛉雄性生殖系统的解剖学特征,并与其它种类作了比较。  相似文献   

狗尾草某些生物学特性的研究简报   总被引：1，自引：0，他引：1  

付迎春  朴亨三  穆瑞娜 《植物保护学报》1986,13(3):186-186,200

狗尾草Setaria viridis(L.)Beauv.是黑龙江省杂草中仅次于稗草(Echinochloa erusgalli)的危害种群。据调查狗尾草发生频率为49％,危害指数16,以小麦,谷子、大豆、玉米田为多。  相似文献   

Development of a functional scoring system in dogs with acute spinal cord injuries     

Olby NJ  De Risio L  Muñana KR  Wosar MA  Skeen TM  Sharp NJ  Keene BW 《American journal of veterinary research》2001,62(10):1624-1628

OBJECTIVES: To develop and compare the reliability of 2 methods of scoring pelvic limb gait in dogs recovering from thoracolumbar spinal cord injuries and to use this scoring system to determine the rate and level of functional recovery of dogs with acute thoracolumbar intervertebral disk herniations. ANIMALS: 46 dogs with spinal cord injuries resulting from intervertebral disk herniations. PROCEDURE: Dogs' gaits were videotaped at different time intervals after injury. In phase 1 of the study, the stages of recovery of pelvic limb function were identified, and a numeric scoring system was devised to reflect that recovery. In phase 2, pelvic limb gait was scored by different observers, using a numeric and a visual analog scale. Intra- and interobserver coefficients of variability of both methods were compared. In phase 3, pelvic limb function was scored, using the numeric scale at various intervals after acute thoracolumbar disk herniations. RESULTS: The numeric scale was significantly more reliable than the visual analog scale when both intra- and interobserver coefficients of variability were evaluated. Dogs that were paraplegic with no deep pain sensation recovered at different rates during the first 3 months, whereas dogs that were paraplegic with deep pain sensation typically recovered within 1 month of injury. CONCLUSIONS: Pelvic limb gait of dogs recovering from thoracolumbar spinal cord injuries can be reliably quantified, using a numeric scale. This scale will facilitate the performance of clinical trials aimed at improving the outcome of acute spinal cord injuries.  相似文献   

An in vitro study of hematopoietic progenitor cells from peripheral blood of rabbits          下载免费PDF全文

Pablo Gómez-Ochoa  Francisco Javier Miana-Mena  María Jesús Mu?oz  Encarna Cativiela    Francisco Gómez 《Canadian journal of veterinary research》2005,69(4):309-312

The purpose of this study was to isolate and cultivate a subpopulation of pluripotent stem cells (PSCs) from the peripheral blood of rabbits, which are frequently used in veterinary research as an animal model. Pluripotent stem cells, as described in human beings, are fibroblast-like cells that exhibit a CD34 marker, specific from other hematopoietic stem cells. Commonly used human commercial media has been researched for culturing rabbit PSCs. These findings allow us to contemplate the direct application of this simple and standardized methodology in several areas of study, such as of the pharmacological effect of many drugs on hematopoietic cells, veterinary practice, and even the study of new strategies in cellular therapy for some human diseases.  相似文献   

4种棉蚜抗药性种群的生命力及繁殖力   总被引：6，自引：0，他引：6  

于金凤  慕立义  王开运 《植物保护学报》1996,23(1):73-78

用4种杀虫剂以浸渍法分别累代处理敏感棉蚜,以选育抗药性。每选育4代进行1次毒力测定及生命力和繁殖力的观察。选育至12代,棉蚜对溴氰菊酯的抗性倍数达4031.4倍,对久效磷、灭多威及硫丹的抗性倍数分别仅为6.3、6.1及4.0倍。棉蚜对溴氰菊酯抗性水平较低时,其生命力及繁殖力略低于敏感品系,随着抗性水平的提高,其生命力和繁殖力也随之增强,RF_(8)接近敏感品系的水平,RF_(12)及RF_(16)则明显超过。灭多威及硫丹抗性种群随抗性水平的提高,其生命力及繁殖力表现不同程度的降低。久效磷抗性种群,各抗性水平下其生命力和繁殖力与敏感品系相比无显著差异。  相似文献