| 1 | Ecoregional variations of aboveground biomass and stand structure in evergreen broadleaved forests显示文摘Biotic and abiotic factors control aboveground biomass(AGB)and the structure of forest ecosystems.This study analyses the variation of AGB and stand structure of evergreen broadleaved forests among six ecoregions of Vietnam.A data set of 1731-ha plots from 52 locations in undisturbed old-growth forests was developed.The results indicate that basal area and AGB are closely correlated with annual precipitation,but not with annual temperature,evaporation or hours of sunshine.Basal area and AGB are positively correlated with trees>30 cm DBH.Most areas surveyed(52.6%)in these old-growth forests had AGB of 100–200 Mg ha^-1;5.2%had AGB of 400–500 Mg ha^-1,and 0.6%had AGB of>800 Mg ha^-1.Seventy percent of the areas surveyed had stand densities of 300–600 ind.ha^-1,and 64%had basal areas of 20–40 m^2 ha^-1.Precipitation is an important factor influencing the AGB of old-growth,evergreen broadleaved forests in Vietnam.Disturbances causing the loss of large-diameter trees(e.g.,>100 cm DBH)affects AGB but may not seriously affect stand density. | Tran Van Do Mamoru Yamamoto Osamu Kozan Vo Dai Hai Phung Dinh Trung Nguyen Toan Thang Lai Thanh Hai Vu Thanh Nam Trieu Thai Hung Hoang Van Thang Tran Duc Manh Cao Chi Khiem Vu Tien Lam Nguyen Quang Hung Tran Hoang Quy Pham Quang Tuyen Trinh Ngoc Bon Nguyen Thi Thu Phuong Ninh Viet Khuong Nguyen Van Tuan Dang Thi Hai Ha Tran Hai Long Dang Van Thuyet Dang Thinh Trieu Nguyen Van Thinh Tran Anh Hai Duong Quang Trung Nguyen Van Bich Dinh Hai Dang Pham Tien Dung Nguyen Huy Hoang Le Thi Hanh Phan Minh Quang Nguyen Thi Thuy Huong Hoang Thanh Son Nguyen Thanh Son Nguyen Thi Van Anh Nguyen Thi Hoai Anh Pham Dinh Sam Hoang Thi Nhung Hoang Van Thanh Nguyen Huu Thinh Tran Hong Van Ho Trung Luong Bui Kieu Hung | 2020 | Journal of Forestry Research2020，31，5： | 1 |
| 2 | Ecological and behavioural risk factors of scrub typhus in central Vietnam:a case-control study显示文摘Background The risk factors for scrub typhus in Vietnam remain unknown.Scrub typhus caused by Orientia tsutsugamushi often presents as an undifferentiated febrile illness and remains under appreciated due to the limited availability of diagnostic tests.This tropical rickettsial illness is increasingly recognized as an important cause of non-malaria acute undifferentiated fever in Asia.This study aimed to investigate behavioural and ecological related risk factors of scrub typhus to prevent this potentially life-threatening disease in Vietnam.Methods We conducted a clinical hospital-based active surveillance study,and a retrospective residence-enrolment date-age-matched case–control study in Khanh Hoa province,Vietnam,from August 2018 to March 2020.Clinical examinations,polymerase chain reaction and enzyme-linked immunosorbent assay IgM tests were applied to define cases and controls.All enrolled participants filled out a questionnaire including demographic socio-economic status,personal behaviors/protective equipment,habitat connections,land use,and possible exposure to the vector.Multivariable conditional logistic regression was used to define the scrub typhus associated risk factors.Results We identified 44 confirmed cases and matched them with 152 controls.Among cases and controls,the largest age group was the 41–50 years old and males accounted for 61.4%and 42.8%,respectively.There were similarities in demographic characteristics between the two groups,with the exception of occupation.Several factors were significantly associated with acquisition of scrub typhus,including sitting/laying directly on household floor[adjusted OR(aOR)=4.9,95%CI:1.6–15.1,P=0.006],household with poor sanitation/conditions(aOR=7.9,95%CI:1.9–32.9,P=0.005),workplace environment with risk(aOR=3.0,95%CI:1.2–7.6,P=0.020),always observing mice around home(aOR=3.7,95%CI:1.4–9.9,P=0.008),and use of personal protective equipment in the field(aOR=0.4,95%CI:0.1–1.1,P=0.076).Conclusions Ecological and household hygiene-related factors were more associated with scrub typhus infection,than individual-level exposure activities in the hyper-endemic area.These findings support local education and allow people to protect themselves from scrub typhus,especially in areas with limitations in diagnostic capacity. | Hanh Thi Duc Tran Jan Hattendorf Hung Manh Do Thanh Tien Hoang Hang Thi Hai Hoang Hoa Ngoc Lam Mai Kim Huynh Lan Thi Hoang Vu Jakob Zinsstag Daniel Henry Paris Esther Schelling | 2021 | Infectious Diseases of Poverty2021，10，4： | 1 |
| 3 | Marker-Assisted Selection of Xa21 Conferring Resistance to Bacterial Leaf Blight in indica Rice Cultivar LT2显示文摘Bacterial leaf blight of rice (BLB), caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient parent.IRBB21, which carries the Xa21 gene, was used as the donor parent. The resistance gene Xa21 was introduced into LT2 by marker-assisted backcrossing. Three Xoo races were used to inoculate the improved lines following the clipping method. Eleven BC_3F_3 lines carrying Xa21 were obtained based on molecular markers and agronomic performance. The 11 lines were then inoculated with the three Xoo races. All the 11 improved lines showed better resistance to BLB than the recipient parent LT2. Based on the level of resistance to BLB and their agronomic performance, five lines (BC_3F_3 5.1.5.1, BC_3F_3 5.1.5.12, BC_3F_3 8.5.6.44, BC_3F_3 9.5.4.1 and BC_3F_3 9.5.4.23) were selected as the most promising for commercial release. These improved lines could contribute to rice production in terms of food security. | Hue Thi NGUYEN Quang Hong VU Tan Van MAI Thu Thi NGUYEN Lam Duc VU Tung Thanh NGUYEN Long Viet NGUYEN Hien Thu Thi VU Hue Thi NONG Trung Nguyen DINH Nakano TOSHITSUGU Liet Van VU | 2018 | Rice science2018，25，1： | 0 |
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