Economic feasibility of recirculating aquaculture systems in pangasius farming     

Pham Thi Anh Ngoc  Miranda P. M. Meuwissen  Le Cong Tru  Roel H. Bosma  Johan Verreth  Alfons Oude Lansink 《Aquaculture Economics & Management (Blackwell Science)》2016,20(2):185-200

This study aims to analyze the economic feasibility of recirculating aquaculture systems (RAS) in pangasius farming in Vietnam. The study uses a capital budgeting approach and accounts for uncertainty in key parameters. Stochastic simulation is used to simulate the economic performance of medium and large farms operating with a traditional system or RAS. Data are obtained through structured surveys and a workshop in the Mekong River Delta. Results show that for large farms, net present value increases from an average of 589,000 USD/ha to 916,000 USD/ha after implementing RAS. Overall, the probability that RAS is a profitable investment is found to be 99% for both farm sizes. With RAS, the crucial parameters determining profitability are price, yield, costs of fingerling, feed, and initial investment. Findings on the robustness of the economic performance of RAS are useful to support public and private decision making towards increasing the sustainability of pangasius production.  相似文献   

Development of a co-dominant SCAR marker linked to the Ph-3 gene for Phytophthora infestans resistance in tomato (Solanum lycopersicum)     

Hai Thi Hong Truong  Hung Ngoc Tran  Hak Soon Choi  Pue Hee Park  Hye Eun Lee 《European journal of plant pathology / European Foundation for Plant Pathology》2013,136(2):237-245

Random amplified polymorphism DNA (RAPD) and bulk segregant analysis (BSA) approaches were used to characterize the molecular marker linked to the Phytophthora infestans resistance gene Ph-3 in tomato. A total of 800 RAPD primers were screened. One RAPD marker UBC#602 was identified to be tightly linked to the Ph-3 gene. The marker was successfully converted into a co-dominant sequence characterized amplified region (SCAR) marker. The SCAR marker SCU602 was used to analyze 96 F₂ progenies and fitted the expected 1:2:1 Mendelian segregation ratio. Forty one tomato inbred lines were screened using the SCAR marker in comparison with a reference marker linked to the Ph-3 gene and both markers gave the same results. SCU602 was further validated for association to resistance and its potential in MAS in 72 tomato lines and cultivars. The marker identified three genotypes harbouring the resistance allele. This SCAR marker can be used in breeding programs for the selection of the Ph-3 gene for Phytophthora infestans resistance.  相似文献   

甜瓜属野生种Cucumis hystrix Chakr.胞质葡萄糖-6-磷酸脱氢酶基因的克隆与启动子结构分析     

曹明明  吴志明  娄群峰  阮氏清云  陈劲枫 《南京农业大学学报》2013,(2):25-30

根据植物葡萄糖-6-磷酸脱氢酶(G6PDH,EC1.1.1.49)氨基酸保守区域,设计简并引物,采用RT-PCR技术克隆得到甜瓜属野生种Cucumis hystrix Chakr.(2n=24)G6PDH基因cDNA片段;随后基于该序列设计特异引物,PCR方法筛选野生种BAC文库,获得2个BAC阳性单克隆。测序后获得了G6PDH基因全序列及其上游启动子序列,GenBank登录号:JQ771576。序列分析显示:G6PDH基因全长约6.5 kb,由15个外显子和14个内含子组成;内含子序列均符合5’-gt-ag-3’结构。外显子拼接后获得了G6PDH基因的开放阅读框(ORF)序列,序列全长1 551 bp,编码516个氨基酸,与黄瓜基因组网站公布的G6PDH基因核苷酸序列和氨基酸序列同源性分别为98.71%和99.03%。野生种G6PDH氨基酸序列N端缺少转运肽序列,确定为野生种胞质G6PDH。氨基酸序列与烟草、马铃薯、荷兰芹、猕猴桃、拟南芥、大豆、小麦、玉米、葡萄、杨树等植物胞质G6PDH同源性高达77%以上。系统发育树分析发现,甜瓜属胞质G6PDH与茄科植物最先聚类,植物胞质G6PDH在分子进化水平上与物种进化相符。启动子结构分析表明:序列含有启动子基本元件TATA-box、CAAT-box,还含有丰富的光响应元件,与环境胁迫响应相关的不同顺式作用元件,促进高水平转录的5UTR Py-rich stretch元件和提高表达的CAT-box元件等。  相似文献   

Different crop rotation systems as drivers of change in soil bacterial community structure and yield of rice, <Emphasis Type="Italic">Oryza sativa</Emphasis>     

Do?Thi?XuanEmail author  Vo?Thi?Guong  Anna?Rosling  Sadhna?Alstr?m  Benli?Chai  Nils?H?gberg 《Biology and Fertility of Soils》2012,48(2):217-225

Intensive cropping, especially of rice, is considered to contribute to negative effects not only on soil chemical and biological properties but also on long-term grain yield. Appropriate crop rotation is often practiced as an alternative strategy to overcome the negative side effects of intensive cropping. Although soil microbial diversity and community structure have been shown to respond differently to altered agricultural management practices, little is known about possible links between crop rotation and grain yield on bacterial communities in rice paddy soil. In this study, we investigated the impact of specific rotational crops and compared it with intensive rice cultivation. The main crop rice (Oryza sativa) was rotated with maize (Zea mays) and mungbean (Phaseolus aureus) in different combinations in a system cultivating three crops per year. Soil bacterial communities were studied in two different cropping periods using pyrosequencing of the variable V4 region of the 16S rRNA. Our results showed that rotation with alternative crops increased rice yield by 24–46% depending on rotation structure and that bacterial community structure was altered in the presence of mungbean and/or maize compared to that in rice monoculture. In the crop rotation systems, composition, abundance, and diversity of soil bacterial communities were significantly different and higher than those in rice monoculture. Our results show that effects of crop rotation relate to changes in soil bacterial community structure suggesting that appropriate crop rotations provide a feasible practice to maintain the equilibrium in soil microbial environment for sustainable rice cultivation.  相似文献   

竹集成材高频热压过程中板坯内温度的变化趋势     

NGUYEN Thi Huong Giang  张齐生 《浙江农林大学学报》2015,(2):167-172

以毛竹Phyllostachys edulis集成材为研究对象,在不同条件下进行高频热压,通过对竹集成材板坯高频热压过程中芯层温度变化的统计分析,得到了竹集成材高频热压过程中板坯温度的变化规律。结果表明:在试验条件范围内,随着板坯含水率从6%增加到18%,涂胶量从200 g·m-2增加到300 g·m-2,板坯的温度明显升高。升温过程可以分为快速升温和慢速升温2个阶段。在快速升温阶段板坯内的温度随板坯初含水率、涂胶量及加热时间的提高而递增;在慢速升温阶段板坯初含水率及涂胶量对板坯内的温度的影响很小,板坯芯层升温速度随加热时间的增加而减少。通过试验数据分析,得出较优的高频热压胶合工艺条件为:涂胶量300 g·m-2,竹条含水率12%,高频热压时间7 min。  相似文献   

基于SRTM_DEM的泾河流域特征信息提取研究   总被引：2，自引：0，他引：2  

王峥  Nguyen Thi Tinh  马孝义  尹京川  胡杰华 《中国农村水利水电》2011,(11)

流域特征信息的提取对于水文地理信息分析、模拟技术和水文模型建立具有重要意义。基于STRM_DEM数据,在ArcGIS9．3环境下,提取泾河流域坡度、坡向等地形特征,以及河网、流域边界和面积等水文要素,并划分子流域。分析表明,当闽值取5000（40．5km^2）时,生成的流域河网能够较好地反映该地区水系。根据河网分级、低级集水区域生成结果和流域地形特征,可划分为32个子流域,为流域分布式水文模型的构建提供了基础地理信息。SRTM_DEM提取泾河和部分支流流域面积误差均较小,说明提取结果与实际非常接近。结果表明,SRTM_DEM数据和ArcGIS9．3提取流域特征信息方便快捷,具有较高的精度和准确性,应用前景广阔。  相似文献   

Optimization of in vitro embryo production and zygote vitrification for the indigenous Vietnamese Ban pig: The effects of different in vitro oocyte maturation systems     

Nhung Thi Nguyen  Nguyen Xuan Bui  Viet Linh Nguyen  Van Khanh Nguyen  Kazuhiro Kikuchi  Hiep Thi Nguyen  Hong Thi Nguyen  Hoang Thinh Nguyen  Quyen Van Dong  Hoang Ha Chu  Ngo Thi Kim Cuc  Tamas Somfai 《Animal Science Journal》2020,91(1)

The Vietnamese Ban pig is a precious genetic resource that needs to be preserved. In vitro embryo production from in vitro matured (IVM) oocytes is an important tool for the utilization of cryopreserved porcine sperm. The aim of this study was to compare two media for the IVM of Ban pig oocytes. Immature oocytes were subjected to IVM either in a non‐defined (TCM‐199 + pig follicular fluid) or in a defined base medium (POM + epidermal growth factor). At the end of IVM, the oocytes were in vitro fertilized (IVF) with frozen Ban sperm. Ten hours after IVF, the oocytes were either subjected to orcein staining to check fertilization and maturation status or cultured in vitro for 7 days. There was no difference between the two IVM media in terms of percentages of oocyte maturation and blastocyst production. However, the percentage of male pronuclear formation after IVF and the total cell numbers in blastocysts were higher with the defined system. Zygotes obtained by the two IVM systems survived vitrification at similar rates. In conclusion, the two IVM systems were both effective for the production of Ban pig embryos; however, better embryo quality was achieved with the defined one.  相似文献   

Mapping the pork value chain in Vietnam: a systematic review     

Nguyen Thi Thuy  Man  Dorny  Pierre  Lebailly  Philippe  Le Thi Minh  Chau  Nguyen Thi Thu  Huyen  Dermauw  Veronique 《Tropical animal health and production》2020,52(6):2799-2808

Tropical Animal Health and Production - In Vietnam, pork is the most commonly consumed type of meat, and the demand is expected to rise even further. Nevertheless, food safety is a major concern,...  相似文献   

New Deoxyisoaustamide Derivatives from the Coral-Derived Fungus Penicillium dimorphosporum KMM 4689     

Olesya I. Zhuravleva  Alexandr S. Antonov  Vo Thi Dieu Trang  Mikhail V. Pivkin  Yuliya V. Khudyakova  Vladimir A. Denisenko  Roman S. Popov  Natalya Y. Kim  Ekaterina A. Yurchenko  Andrey V. Gerasimenko  Anatoly A. Udovenko  Gunhild von Amsberg  Sergey A. Dyshlovoy  Shamil S. Afiyatullov 《Marine drugs》2021,19(1)

Seven new deoxyisoaustamide derivatives (1–7) together with known compounds (8–10) were isolated from the coral-derived fungus Penicillium dimorphosporum KMM 4689. Their structures were established using spectroscopic methods, X-ray diffraction analysis and by comparison with related known compounds. The absolute configurations of some alkaloids were determined based on CD and NOESY data as well as biogenetic considerations. The cytotoxic and neuroprotective activities of some of the isolated compounds were examined and structure-activity relationships were pointed out. New deoxyisoaustamides 4–6 at concentration of 1 µM revealed a statistical increase of PQ(paraquat)-treated Neuro-2a cell viability by 30–39%.  相似文献   

Local and landscape effects of agricultural intensification on Carabid community structure and weed seed predation in a perennial cropping system     

Adrien Rusch  Delphine Binet  Lionel Delbac  Denis Thiéry 《Landscape Ecology》2016,31(9):2163-2174

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