4,276 research outputs found
Impacts of farmer-based training in seed production in Vietnam
No full textKey words: farmer seed production school, farm-saved seed, formal seed sector, impact assessment, improved practice, local practice, rice (Oryza sativa), seed production, seed quality, Vietnam Rice (Oryza sativa) is the most important food and cash crop of Vietnam. It is cultivated in all provinces of the country since ancient times. Farm-saved seed is the most important seed source covering more than 80% of the farmers’ seed needs. However, farmers not always use the best techniques of producing and selecting seeds. Inadequate seed quality is an important yield limiting factor in rice production. To improve the farmers’ capacity to produce, process, store and use good rice seed, the farmer seed production school (FSPS) training programme was conducted in seven provinces of Vietnam during the period 2003−2007. The study reported in this thesis took place in four out of those seven provinces, i.e. Nam Dinh, Nghe An, Binh Dinh and Dong Thap. The objective was to assess to what extent farmers’ knowledge in seed production practices and seed quality management had increased and whether that knowledge increase was reflected in an increase in potential rice yields and profits, and in diffusion of retained practices after training to other farmers in communities. A long seed production training programme with the farmer field school approach was combined with field demonstrations including plots with either local practices or improved practices which were conducted in each FSPS. We recorded and analysed data on on-farm demonstrations at 429 FSPSs and on ex-ante and ex-post tests of knowledge at the FSPSs. Moreover, we carried out a survey among 240 rural households. Results of the study indicate that some rice varieties were better adopted in the farming systems than other varieties: well adopted ones were KD18 in both Nam Dinh and Nghe An province and OM1490, Ai32 and MO2718 in Binh Dinh and Dong Thap. With local practices in the farm-saved seed system of the transplanted rice crop, farmers used old seedlings, planted many seedlings per hill, planted too many or too few plants per unit area and applied unbalanced quantities of fertilizers; for the directly sown crop farmers used high seed rates in the traditional system. Rice yields showed larger differences between local practices and improved practices in the dry season than in the wet season all across Vietnam. With improved practices at the FSPSs, rice yields were 8.5% higher in the wet season and 13.6% higher in the dry season; additional profits associated with the improved practice in both the dry and wet seasons averaged 212 US$ ha-1. The majority of the FSPS-farmers moved from food production to seed production, reduced seed rates by about 50%, and used high quality seed to produce seeds with much better quality. More important is that the FSPS-farmers diffused improved practices (79%) and shared good seeds (57% of respondents) with other farmers in their communities to help other rice growers to improve their productivity. A large proportion of non-FSPS farmers learned and applied improved practices for rice production through neighbouring FSPS-farmers within the community. Besides, evaluation in acquired knowledge during training showed that FSPS-farmers with lower scores (<20%) in the ex-ante test realized an enormous improvement of 55.4% points in the ex-post test. There was a clear trend: the higher the scores in the ex-ante test, the smaller the increase in the score, suggesting that the tests provided insight into the knowledge gaps for improvement in training programmes. The FSPS is considered as a good training model for farmers. The FSPS-farmers well retained the acquired knowledge and applied the improved practices to enhance the farm-saved seed system in the project provinces. The community capacity was strengthened through establishing seed clubs by FSPS-farmers. It created a seed supply and production network to ensure seed security for small farmer’s seed needs in the rural areas. Thus, it promoted seed policies to strengthen the informal seed system in Vietnam. Impacts of farmer-based training programme in seed production illustrate that in a country like Vietnam where more than seventy percent of the population live in rural areas and depend on agricultural production, farmer education is a very effective way for agricultural development
Nguyen Quang, P., Vo Quang, Y. & Voisin, J.-F. — The White-nest Swiftlet and the Black-nest Swiftlet : a monograph. Editions Boubée, 9 rue de Savoie, 75006 Paris. 2002
No full textJouanin Christian. Nguyen Quang, P., Vo Quang, Y. & Voisin, J.-F. — The White-nest Swiftlet and the Black-nest Swiftlet : a monograph. Editions Boubée, 9 rue de Savoie, 75006 Paris. 2002. In: Revue d'Écologie (La Terre et La Vie), tome 58, n°2, 2003. pp. 251-252
Asymptomatic malaria cases in Dak Buk So, Dak Ngo and Quang Truc communes by RT-qPCR (1<sup>st</sup>/ 2<sup>nd</sup> cohorts) analysis.
No full textAsymptomatic malaria cases in Dak Buk So, Dak Ngo and Quang Truc communes by RT-qPCR (1st/ 2nd cohorts) analysis.</p
Characteristics of the study populations at Dak Buk So, Dak Ngo and Quang Truc communes, Tuy Duc district, Dak Nong province, Central Highlands of Vietnam.
No full textCharacteristics of the study populations at Dak Buk So, Dak Ngo and Quang Truc communes, Tuy Duc district, Dak Nong province, Central Highlands of Vietnam.</p
Research Method for Assessing the Potential of Solar Power in Quang Ngai Province
No full textIn this paper, the author presents a research method for assessing the potential of solar power and applies it to Quang Ngai province. The method includes five steps: data acquisition, brief assessment of resources potential, the theoretical potential, the technique potential and the economic potential. Based on these assessments, the article identifies areas and location where solar power projects can be implemented to meet the local requirements and government regulations, and bring about socio-economic benefits. This research method can be adopted in other localities, contributing positively to the development of solar power, meeting the increasing demand for electricity in our country
Richard Dean Burns et Milton Leitenberg. The Wars in Vietnam, Cambodia and Laos (1945-1982). A Bibliographic Guide
No full textBui Xuan Quang. Richard Dean Burns et Milton Leitenberg. The Wars in Vietnam, Cambodia and Laos (1945-1982). A Bibliographic Guide. In: Politique étrangère, n°2 - 1984 - 49ᵉannée. p. 499
Richard Dean Burns et Milton Leitenberg. The Wars in Vietnam, Cambodia and Laos (1945-1982). A Bibliographic Guide
No full textBui Xuan Quang. Richard Dean Burns et Milton Leitenberg. The Wars in Vietnam, Cambodia and Laos (1945-1982). A Bibliographic Guide. In: Politique étrangère, n°2 - 1984 - 49ᵉannée. p. 499
THIẾT KẾ, TỔNG HỢP VÀ GIẢI THÍCH HUỲNH QUANG CỦA CHEMODOSIMETER TỪ DẪN XUẤT FLUORESCEIN BẰNG LÝ THUYẾT PHIẾM HÀM MẬT ĐỘ
No full textThis work presents the design and synthesis theories of chemodosimeter FS to determine Hg2+ based on lactam ring-opening reaction of fluorescein derivative using density-functional theory (DFT). All theoretical calculations including DFT, TD–DFT, and NBO were carried out with the B3LYP function Gaussian03 software. The comparison of geometric parameters (bond lengths, bond angle, and dihedral angles of atoms) of fluorescein optimized with two basis sets LanL2DZ and 6-311+G(d, p) by means of t–test pairs suggested that LanL2DZ not only reduced the computation time but also gave reliable results. Fluorescent properties of the chemodosimeter FS were explained through TD–DFT and NBO analysis. The results showed that FS was non-fluorescent because of π conjugated system interruption which was due to the existence of the lactam ring. In FG, a product of the reaction between FS and Hg2+, the lactam ring structure was disrupted, and 1,3,4-oxadiazole was formed, resulting in the existence of a conjugated π system from the fluorophore to the receptor, and therefore FG was fluorescent. Accordingly, FS is predicted as an OFF–ON chemodosimeter.Bài báo này, trình bày lý thuyết thiết kế và tổng hợp chemodosimeter FS để xác định Hg2+ dựa vào phản ứng mở vòng lactam của dẫn xuất fluorescein, bằng lý thuyết phiếm hàm mật độ (DFT). Tất cả các tính toán lý thuyết về DFT, TD-DFT, NBO trong bài báo này được thực hiện với hàm B3LYP bằng phần mềm Gaussian03. Đồng thời qua so sánh các thông số hình học (độ dài liên kết, góc liên kết, góc nhị diện của các nguyên tử) của fluorescein đã được tối ưu với hai bộ hàm cơ sở LanL2DZ và 6-311+G(d,p) bằng phương pháp t-test từng cặp, cho thấy có thể sử dụng bộ hàm cơ sở nhỏ LanL2DZ để giảm thời gian tính toán mà vẫn cho kết quả đáng tin cậy. Tính chất huỳnh quang của chemodosimeter FS được giải thích qua phân tích TD-DFT, NBO. Kết quả cho thấy FS không phát huỳnh quang, nguyên nhân là do trong FS tồn tại vòng lactam làm cho hệ liên hợp π trong fluorophore bị gián đoạn dẫn đến sự tắt huỳnh quang trong FS; trong FG ( sản phẩm của FS khi tác dụng với Hg2+) cấu trúc vòng lactam bị phá vỡ, đồng thời tạo vòng 1,3,4-oxadiazole, dẫn tới sự hình thành hệ liên hợp π từ fluorophore cho đến receptor, vì vậy phân tử FG phát huỳnh quang. Do đó, chemodosimeter FS được dự đoán hoặt động kiểu OFF-O
Leptomischus anisophyllus T. P. Anh, B. H. Quang, Nuraliev & L. Wu 2021, sp. nov.
No full textLeptomischus anisophyllus T.P.Anh, B.H.Quang, Nuraliev & L.Wu, sp. nov. (Figs. 1, 2) Diagnosis: —Similar to Leptomischus erianthus, L. funingensis, L. hiepii and L. parviflorus, differing from them and from the other species of Leptomischus by the following combination of morphological traits: stems terete, pubescent when young, leaves mostly strongly anisophyllous, flowers distylous, corolla tube 10–15 mm long. Type: — VIETNAM. Nghe An Province: Con Cuong District, Luc Da Commune, Pu Mat National Park, Kem waterfall area, 18°58’11.1’’N 104°48’01.9’’E, 261 m, 18 February 2017, H. Q . Bui 203 (holotype: HN; isotypes: CSFI, HN, LE, MW).Published as part of Anh, Tran Thi Phuong, Quang, Bui Hong, Nuraliev, Maxim S., Nguyen, Khang Sinh & Averyanov, Leonid V., 2021, Leptomischus anisophyllus (Argostemmateae: Rubiaceae), a new species from Vietnam, pp. 198-204 in Phytotaxa 507 (2) on page 199, DOI: 10.11646/phytotaxa.507.2.8, http://zenodo.org/record/542565
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