Assessment of insecticidal effects and selectivity of CAPA‐PK peptide analogues against the peach‐potato aphid and four beneficial insects following topical exposure     

Shun‐Hua Gui  Clauvis NT Taning  Kristof De Schutter  Qun Yang  Pengyu Chen  Mohamad Hamshou  Ronald J Nachman  Aniruddha A Pandit  Julian AT Dow  Shireen Davies  Guy Smagghe 《Pest management science》2020,76(10):3451-3458

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Comparative energy and economic analyses of conventional and System of Rice Intensification (SRI) methods of rice production in Thai Nguyen Province,Vietnam     

Tuyet Thi Anh Truong  John Fry  Phu Van Hoang  Hoang Huy Ha 《Paddy and Water Environment》2017,15(4):931-941

The consumption of energy inputs in agricultural production has been increasing rapidly during the past decades. However, given the limitations and costs of non-renewable energy, increasing production while using the least energy possible has become a major concern of most nations. Prompted by this concern, we conducted a face-to-face survey of 90 farming households in Thai Nguyen Province, Vietnam, to find out how energy is being used in agriculture and, specifically, in their rice production. Through analysis of energy input–output balances, combined with economic efficiency analysis, a comparison was made of conventional and SRI methods of rice production. The study found that applying the SRI method can save around 23% of energy inputs, while increasing energy outputs by 11%. Economic benefits per hectare also rise by more than 8 million dong (USD 364) compared to those under the conventional cultivation system. The study also showed conflicts between the energy and economic balances for manual compared with machine ploughing operations. This study contributes to providing an overview of energy consumption in rice cultivation at the household level. Its findings can help stakeholders to assess current policies and make better decisions on the uses of energy in agricultural production. In addition, the comprehensive approach taken here to analysing energy use and efficiency could expand the analysis and comparison of energy uses at sectoral or activity level—still a new field in Vietnam and many other countries.  相似文献   

中越水稻迁飞性害虫稻飞虱、稻纵卷叶螟发生关系分析   总被引：3，自引：0，他引：3  

陆明红  刘万才  胡高  翟保平  Hoang Anh Tuan  Do Hong Khanh 《植物保护》2018,44(3):31-36

中越两国同属东亚季风区,水稻病虫害在发生危害上为一个整体。每年水稻稻飞虱、稻纵卷叶螟(以下简称"两迁"害虫)随着季节和气温变化,在两国间往返迁飞,发生为害,相互影响。研究两国水稻迁飞性害虫发生的关系和影响规律,对于提高监测预警的早期预见性和防控工作的主动性,有效控制其危害具有重要意义。2010年以来,中越两国实施了中越水稻迁飞性害虫监测与防治合作项目,通过连续多年开展交流合作,初步明确了越南"两迁"害虫发生规律。本文简要分析了影响越南"两迁"害虫发生的主要因素,探讨了中越两国水稻"两迁"害虫发生规律的相关性,对提高中国"两迁"害虫中、长期预报能力和综合治理水平发挥了积极作用。  相似文献   

Evaluation of the microbiological safety and quality of Vietnamese <Emphasis Type="Italic">Pangasius hypophthalmus</Emphasis> during processing by a microbial assessment scheme in combination with a self-assessment questionnaire     

Anh?Ngoc?Tong Thi  Liesbeth?Jacxsens  Bert?Noseda  Simbarashe?Samapundo  Binh?Ly?Nguyen  Marc?Heyndrickx  Frank?DevlieghereEmail author 《Fisheries Science》2014,80(5):1117-1128

Pangasius hypophthalmus (referred to as Pangasius or tra fish in Vietnam) has become highly appreciated by consumers in the European Union, USA, Japan, etc. and is of worldwide economic importance. Therefore, the microbial quality and safety of Pangasius fish processed for export was assessed by means of a microbial assessment scheme throughout the entire production process. A total of 144 samples were collected from various processing steps and analyzed. It was determined that the microbial safety and quality of the products was not guaranteed as the contamination levels remained high throughout processing. Escherichia coli, Staphylococcus aureus and Vibrio cholerae were present on the hands of food operators, particularly those in the packaging area. Moreover, the presence of Listeria monocytogenes (1 positive out of 9 samples) and V. cholerae (4/9) on the final products was likely a result of inadequate hygiene practices in the processing environment. Also discussed in this paper are the results of a self-assessment questionnaire, which provide insight into the performance of the food safety management system currently implemented at the company. These data are of major importance in order to contribute valuable information to the local and international trade point of view in general and to the intended customers in particular.  相似文献   

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   

Heterologous expression and characterization of an N-acetyl-β-D-hexosaminidase from Lactococcus lactis ssp. lactis IL1403     

Nguyen HA  Nguyen TH  Křen V  Eijsink VG  Haltrich D  Peterbauer CK 《Journal of agricultural and food chemistry》2012,60(12):3275-3281

The lnbA gene of Lactococcus lactis ssp. lactis IL1403 encodes a polypeptide with similarity to lacto-N-biosidases and N-acetyl-β-D-hexosaminidases. The gene was cloned into the expression vector pET-21d and overexpressed in Escherichia coli BL21* (DE3). The recombinant purified enzyme (LnbA) was a monomer with a molecular weight of approximately 37 kDa. Studies with chromogenic substrates including p-nitrophenyl N-acetyl-β-D-glucosamine (pNP-GlcNAc) and p-nitrophenyl N-acetyl-β-D-galactosamine (pNP-GalNAc) showed that the enzyme had both N-acetyl-β-D-glucosaminidase and N-acetyl-β-D-galactosaminidase activity, thus indicating that the enzyme is an N-acetyl-β-D-hexosaminidase. K(m) and k(cat) for pNP-GlcNAc were 2.56 mM and 26.7 s(-1), respectively, whereas kinetic parameters for pNP-GalNAc could not be determined due to the K(m) being very high (>10 mM). The optimal temperature and pH of the enzyme were 37 °C and 5.5, respectively, for both substrates. The half-life of activity at 37 °C and pH 6.0 was 53 h, but activity was completely abolished after 30 min at 50 °C, meaning that the enzyme has relatively low temperature stability. The enzyme was stable in the pH 5.5-8 range and was unstable at pH below 5.5. Studies with natural substrates showed hydrolytic activity on chito-oligosaccharides but not on colloidal chitin or chitosan. Transglycosylation products were not detected. In all, the data suggest that LnbA's role may be to degrade chito-oligosaccharides that are produced by the previously described chitinolytic system of L. lactis.  相似文献   

Technological Advances to Address Current Issues in Entomology: 2020 Student Debates     

Lina Bernaola  Molly Darlington  Kadie Britt  Patricia Prade  Morgan Roth  Adrian Pekarcik  Michelle Boone  Dylan Ricke  Anh Tran  Joanie King  Kelly Carruthers  Morgan Thompson  John J Ternest  Sarah E Anderson  Scott W Gula  Kayleigh C Hauri  Jacob R Pecenka  Sajjan Grover  Heena Puri  Surabhi Gupta Vakil 《Journal of insect science (Online)》2021,21(2)

The 2020 Student Debates of the Entomological Society of America (ESA) were live-streamed during the Virtual Annual Meeting to debate current, prominent entomological issues of interest to members. The Student Debates Subcommittee of the National ESA Student Affairs Committee coordinated the student efforts throughout the year and hosted the live event. This year, four unbiased introductory speakers provided background for each debate topic while four multi-university teams were each assigned a debate topic under the theme ‘Technological Advances to Address Current Issues in Entomology’. The two debate topics selected were as follows: 1) What is the best taxonomic approach to identify and classify insects? and 2) What is the best current technology to address the locust swarms worldwide? Unbiased introduction speakers and debate teams began preparing approximately six months before the live event. During the live event, teams shared their critical thinking and practiced communication skills by defending their positions on either taxonomical identification and classification of insects or managing the damaging outbreaks of locusts in crops.  相似文献   

Quantitative methods for estimating foliar uptake of zinc from suspension‐based Zn chemicals     

Dang T Vu  Longbin Huang  Anh V Nguyen  Yumei Du  Zhiping Xu  Marc A Hampton  Peng Li  Victor Rudolph 《植物养料与土壤学杂志》2013,176(5):764-775

The present study developed methods for quantifying foliar Zn uptake from suspension‐based Zn chemicals of low solubility, which were ZnO (particle size: 0.15^–1.34 μm) and a newly synthesized Zn hydroxide nitrate crystal (Zn‐HNC) (50^–100 nm thickness and 0.2^–1 μm lateral dimension). Recently matured leaves of citrus (Citrus aurantium L. cv. Valencia), capsicum (Capsicum annume L. cv. Giant Bell), and/or tomato (Solanum lycopersicum L. cv. Roma) were in vitro–treated with microdroplets (5 μL per droplet) of Zn‐HNC‐ and ZnO‐suspension solutions on the adaxial surface and incubated under controlled conditions for up to 72 h. Leaf‐washing protocols were compared, including: dilute ethanol (3%), dilute nitric acid (2%), and their combination. The methods for quantifying Zn uptake were: (1) whole‐leaf loading by which droplets of the Zn suspension solutions were loaded onto central regions of both left and right sides of leaf blades and (2) half‐leaf loading by which soluble‐Zn (ZnSO₄) droplets were loaded onto only one side of leaf blades while the other was used as the background Zn control. Foliar‐surface characteristics of the plant species affected the effectiveness of the washing methods. The dilute nitric acid (2%; ± 3% ethanol) was required to remove residue particles of the ZnO and Zn‐HNC suspensions from foliar surfaces of capsicum and tomato (highly trichomatic), but the residue Zn chemicals on citrus leaves (nontrichomatic and highly waxy) were similarly and effectively removed by the three washing methods. For quantifying Zn uptake by the leaves, the half‐leaf loading method showed its advantages over the whole‐leaf loading method, because it did not stringently require similar background Zn concentrations in the control and treated leaves at the start and had little risks of secondary absorption of soluble Zn in the washing solution.  相似文献   

Changes in fineroot growth dynamics in response to phosphorus application in an Acacia mangium plantation in Vietnam     

Thang  Nguyen Toan  Lam  Vu Tien  Son  Nguyen Huy  Van Do  Tran  Van Thuyet  Dang  Trung  Phung Dinh  Sam  Pham Dinh  Quy  Tran Hoang  Phuong  Nguyen Thi Thu  Huyen  Ly Thi Thanh  Thinh  Nguyen Huu  Van Tuan  Nguyen  Duc  Dao Trung  Ha  Dang Thi Hai  Trung  Duong Quang  Luong  Ho Trung  Anh  Nguyen Thi Hoai 《New Forests》2020,51(5):835-847

Fineroots (≤ 2 mm diameter) are dynamic components of the forest ecosystems and play important role in water and nutrient acquisition in forests. These roots are sensitive to forest fertilization and therefore, the response of fineroots to nutrient application would provide better understanding of the forest carbon and nutrient dynamics that will be helpful in sustainable forest management plans. Two fertilization treatments, including (1) F400: 400 g P₂O₅ (16.5%)/tree and (2) F600: 600 g P₂O₅ /tree, and F0: control (without fertilization), were applied in an Acacia mangium plantation with a planting density of 1100 trees/ha (3 m?×?3 m). The evaluation of fineroot growth across seasons showed that fertilization significantly increased production and subsequent mortality and decomposition. The total decomposition associated with F600 application was 7.95 tons ha^?1 year^?1, equaling 121% of F400 and 160% of the control. Mortality in F600 was 8.75 tons ha^?1 year^?1, equaling 111% of F400 and 198% of F0, while production in F600 was 10.40 tons ha^?1 year^?1, equaling 127% of F400 and 143% of F0. Fineroot production, mortality, and decomposition are seasonally dependent, with higher values measured in the rainy season than in the dry season. Stand basal area increment was significantly correlated with fineroot production (R²?=?0.75), mortality (R²?=?0.44), and decomposition (R²?=?0.48). This study showed that fertilization could facilitate fineroot production, which can then lead to a higher turnover of carbon and nutrients through the decomposition of the greater mass of the fineroots.

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Relationship among ovarian follicular status,developmental competence of oocytes,and anti‐Müllerian hormone levels: A comparative study in Japanese wild boar crossbred gilts and Large White gilts     

Fuminori Tanihara  Maki Hirata  Satoru Iizuka  Shinya Sairiki  Masahiro Nii  Nhien Thi Nguyen  Quynh Anh Le  Takayuki Hirano  Takeshige Otoi 《Animal Science Journal》2019,90(6):712-718

The aim of this study was to investigate the ovarian follicular development, developmental competence of oocytes, and plasma anti‐Müllerian hormone (AMH) levels of Japanese wild boar crossbred (wild hybrid) gilts, whose litter size is inferior to that of European breeds. Ovary and plasma samples were collected from two different breeds of gilts (wild hybrid and Large White breeds). The ovaries from the wild hybrid gilts had a lower average numbers of secondary follicles and vesicular follicles in ovarian cross‐sections and of good quality oocytes collected from ovarian follicles as compared with those from Large White gilts (p < 0.05). The development rate to the blastocyst stage of good quality oocytes after in vitro maturation, fertilization and culture was also lower (p < 0.05) in wild hybrid gilts than in Large White gilts. Plasma AMH levels with >0.16 ng/ml were detected in 8.3% of the examined wild hybrid gilts and 33% of the Large White gilts. These results indicate that the low reproductive performance of wild hybrid breed may result in part from low numbers of vesicular follicles and good quality oocytes, and low developmental competence of oocytes. Moreover, plasma AMH levels may support low number of vesicular follicles in ovaries of wild hybrid gilts.  相似文献