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Brenner E.C.,University of California at Davis | Chomel B.B.,University of California at Davis | Singhasivanon O.-U.,University of California at Davis | Namekata D.Y.,University of California at Davis | And 7 more authors.
Epidemiology and Infection | Year: 2013

SUMMARY Dogs can be infected by a wide range of Bartonella spp., but limited studies have been conducted in tropical urban and rural dog populations. We aimed to determine Bartonella antibody prevalence in 455 domestic dogs from four tropical countries and detect Bartonella DNA in a subset of these dogs. Bartonella antibodies were detected in 38 (8·3%) dogs, including 26 (10·1%) from Colombia, nine (7·6%) from Brazil, three (5·1%) from Sri Lanka and none from Vietnam. DNA extraction was performed for 26 (63%) of the 41 seropositive and 10 seronegative dogs. Four seropositive dogs were PCR positive, including two Colombian dogs, infected with B. rochalimae and B. vinsonii subsp. berkhoffii, and two Sri Lankan dogs harbouring sequences identical to strain HMD described in dogs from Italy and Greece. This is the first detection of Bartonella infection in dogs from Colombia and Sri Lanka and identification of Bartonella strain HMD from Asia. Copyright © Cambridge University Press 2012.


Phong N.D.,International Rice Research Institute | Phong N.D.,Ho Chi Minh City University of Agriculture and Forestry | Hoanh C.T.,International Water Management Institute IWMI | Tuong T.P.,International Rice Research Institute | Malano H.,University of Melbourne
Journal of Environmental Management | Year: 2014

Acidic pollution can cause severe environmental consequences annually in coastal areas overlain with acid sulfate soils (ASS). A water quality model was used as an analytical tool for exploring the effects of water management options and other interventions on acidic pollution and salinity in Bac Lieu, a coastal province of the Mekong Delta. Fifty eight percent of the provincial area is covered by ASS, and more than three-fourths (approximately 175,000ha) are used for brackish-water shrimp culture. Simulations of acid water propagation in the canal network indicate that the combination of opening the two main sluices along the East Sea of the study area at high tide for one day every week in May and June and widening the canals that connect these sluices to the West Sea allows for adequate saline water intake and minimizes the acidic pollution in the study area. On the other hand, canal dredging in the freshwater ASS area should be done properly as it can create severe acidic pollution. © 2014 Elsevier Ltd.


Phong N.D.,International Rice Research Institute | Phong N.D.,Ho Chi Minh City University of Agriculture and Forestry | Hoanh C.T.,International Water Management Institute IWMI | Tuong T.P.,International Rice Research Institute | Wassmann R.,International Rice Research Institute
Proceedings - 7th International Congress on Environmental Modelling and Software: Bold Visions for Environmental Modeling, iEMSs 2014 | Year: 2014

Bac Lieu is a coastal province the Mekong River Delta (MRD), Vietnam. Aside from salinity intrusion from the sea, the province is strongly affected by acidic pollution as 58% of the area (250,000 ha) is overlaid with acid sulphate soil (ASS). Previous studies showed that the eminent sea level rise (SLR) would influence the hydrology and salinity of the canal networks in the province. This study, using the previously validated hydraulic and water quality model VRSAP-ACIDITY (Vietnam River Systems And Plains, coupled with ACIDITY Module), aimed at quantifying impacts of different SLR scenarios (SLR = 17, 30, 50, or 75 cm) on acidic pollution in the province. Under the present sea level, widespread acidic pollution (pH < 5) of surface water occurred at the start of the rainy season, due to leaching of acidity from canal embankments and fields in ASS. The acceleration of SLR reduced the area of acidic polluted water. The lessening in acidic pollution was attributed to (1) SLR that raised the water level in the Mekong River, increasing the amount of fresh water flowing into the study area; and (2) the amount of water drained out of the study area increased, bringing with its acidity. It concluded that SLR has a positive effect on acidic pollution in the ASS coastal area.


Phong N.D.,University of Melbourne | Phong N.D.,International Rice Research Institute | Phong N.D.,Ho Chi Minh City University of Agriculture and Forestry | Tuong T.P.,International Rice Research Institute | And 3 more authors.
Water, Air, and Soil Pollution | Year: 2013

The in-depth knowledge on management and reducing annual acidic pollution is important for improving the sustainable livelihood of people living in areas with acid sulphate soils (ASS). This study involved a long-term (2001-2006), large-scale canal water quality monitoring network (87 locations) and a field experiment at nine sites to quantify the dynamic variability of acidic pollution and its source in a coastal area with ASS in the Mekong River Delta of Vietnam. Widespread acidic pollution (pH <5) of surface water occurred at the beginning of the rainy season, while pH of the canal water remained high (7-8) at the end of the rainy season and during the dry season. The study identified canal embankment deposits, made of ASS spoils from canal dredging/excavation, as the main source of acidic pollution in the surrounding canal network. The findings suggested that there was a linkage between the amount of acidic loads into canal networks and the age of the embankment deposits. The most acute pollution (pH ~ 3) occurred in canals with sluggish tidal water flow, at 1-2 years after the deposition of excavated spoils onto the embankments in ASS. The amount of acidic loads transferred to the canal networks could be quantified from environmental parameters, including cumulative rainfall, soil type and age of embankment deposits. The study implied that dredging/excavation of canals in ASS areas must be carried out judiciously as these activities may increase the source of acidic pollution to the surrounding water bodies. © 2013 Springer Science+Business Media Dordrecht.


Lam V.,University of Veterinary and Animal Sciences | Wredle E.,Swedish University of Agricultural Sciences | Thao N.T.,University of Veterinary and Animal Sciences | van Man N.,Ho Chi Minh City University of Agriculture and Forestry | Svennersten-Sjaunja K.,Swedish University of Agricultural Sciences
African Journal of Agricultural Research | Year: 2010

The aim of this study was to investigate the prerequisites for dairy production at smallholder farms in Southern Vietnam and to identify the strengths and weaknesses in management at farm level. Data on milk production, management routines and heat stress were collected during farmer interviews and field observations on 120 smallholder dairy farms. Individual milk samples were taken from 360 cows. The average herd contained 12 animals (ranging from 2 to 17), dominated by lactating cows. The main dairy breeds were Holstein Friesian crossbreeds, mostly at F2, F3 and F4. The mean Temperature-Humidity Index was 81 (range 75 to 97) in the morning and 85 (range 72 to 104) in the afternoon and the mean respiration rates for cows were 54 (range 30 to 102) and 70 (range 35 to 116) breaths per minute, with mean rectal temperatures of 38.8°C (range 38 to 39) and 39.3°C (range 38.3 - 40.9). The milk somatic cell count (SCC) was high in all farms, averaging 1, 300, 000 cells/mL. The strength of the dairy producers was their willingness for further education, as 80% of the farmers attended training courses, while poor udder health and heat stress were the most pronounced problems. © 2010 Academic Journals.


Nguyen H.P.,University of Science | Tran T.D.,Ho Chi Minh City University of Agriculture and Forestry | Dinh Q.V.,Sungkyunkwan University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

In this paper, we propose a blocking-matching approach to the problem of correspondence in stereo matching. In blocking-matching methods, the correspondence or difference between pixels of a stereo pair is measured by a local window. Despite some area-based stereo matching algorithms have been developed and work well in a number of kinds of regions such as textureless or object boundary regions, their performance can debase once working in some sorts of radiometric conditions. Our proposed algorithm, in which non-parametric transform is used in the pre-processing step and an edge-preserving filter is used in the post-processing step, is an improved method of a shiftable window method and can work robustly in various radiometric conditions. Input images first are pre-processed by the census transform that makes our method robustly when the image pair is captured in various light sources or camera uncovering conditions. The window cost in our approach is calculated from the transformed images using in the Hamming distance, and the similarity is finally selected by a Winner-Takes-All strategy. The experimental results for the Middleburry images show that our proposed algorithm outperforms test local stereo algorithms in radiometrically dissimilarity images. © 2012 Springer-Verlag.


Tran T.D.,Ho Chi Minh City University of Agriculture and Forestry | Nguyen H.P.,University of Science | Dinh Q.V.,Sungkyunkwan University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

In this paper, we proposed two window-based methods, spatial weight shiftable window and spatial weight multiple window, for correspondence problem in stereo matching. The spatial weight shiftable window is an improvement of a shiftable window method while the spatial weight multiple window is an enhancement of a multiple window method. They combine spatial weighted window for each support window, and they hence can work well in the regions of disparity discontinuity or object boundaries. The window costs in our approaches is calculated by deploying spatial weighted window for each support window, and the similarity is finally selected by a Winner-Takes-All strategy. The experimental results for the Middleburry images illustrated that the proposed algorithms outperform test local stereo algorithms. © 2012 Springer-Verlag.


Da C.T.,Swedish University of Agricultural Sciences | Hung L.T.,Ho Chi Minh City University of Agriculture and Forestry | Berg H.,Swedish University of Agricultural Sciences | Lindberg J.E.,Swedish University of Agricultural Sciences | Lundh T.,Swedish University of Agricultural Sciences
Aquaculture Research | Year: 2013

A technical and socio-economic survey was conducted in Dong Thap, Can Tho and An Giang, provinces of Vietnam in 2009. The results showed that most of the small scale farmers of striped catfish (Pangasius hypothalamus) carry out fish pond culture, developed and operated by self-learned experience and from neighbours knowledge. The mean pond depth varied from 3.5 to 4.0 m, ranging from 2 to 6 m. Most of the fish farms have extremely high stocking density, with an average of about 40 fish m-2, in some cases up to 70 fish per m2. The average yields and net income of small-scales pond farming is about 21-27 kg per m2 crop-1 and US$ 0.184-0.329 kg-1 crop-1 respectively. These figures are not significantly different compared with large-scale pond farming. About 75%, 86% and 80% of fish farmers in Dong Thap, Can Tho and An Giang province, respectively, received positive net returns. Farm-made feed is still playing an important role because of higher net profit compared with commercial pellet feeds. Rice bran and trash fish are the main feed ingredients for farm-made feed formulations. Striped catfish farmers are now actively searching for locally produced plant protein sources as alternatives to marine trash fish or fish meal. © 2011 Blackwell Publishing Ltd.


The D.T.,Vietnam Atomic Energy Institute | Khanh N.T.,Vietnam Atomic Energy Institute | Lang V.T.K.,Vietnam Atomic Energy Institute | van Chung C.,Vietnam Atomic Energy Institute | And 2 more authors.
Radiation Physics and Chemistry | Year: 2012

Utilization of phytosanitary irradiation as a potential treatment to disinfest agricultural commodities in trade has expanded rapidly in the recent years. Cobalt-60 gamma ray target doses of 100, 150, 200 and 250 Gy were used to irradiate immatures and adults of Dysmicoccus neobrevipes (Beardsley) (Hemiptera: Pseudococcidae) infesting dragon fruits to find the most tolerant stage and the most optimal dose range for quarantine treatment. In general, irradiation affected significantly all life stages of D. neobrevipes mortality and adult reproduction. The pattern of tolerance to irradiation in D. neobrevipes was 1st instars<2nd instars<3rd instars


Van Xuan N.,Ho Chi Minh City University of Agriculture and Forestry
Zootaxa | Year: 2012

A new species of the genus Macrobrachium, M. hungi was collected in the Tonlé Sap Great Lake of Cambodia. The adult males of this species show a close resemblance to Macrobrachium saigonense Xuân 2006, but they are larger, the rostrum is longer, distally directed upwards or not, with more numerous dorsal and ventral teeth; the tubercles on both sides of the cutting edge on the distal portion of the movable finger are vestigial or crescent shape and less prominent than those of M. saigonense. Notes on economic importance and its habitat which differs from M. saigonense are briefly provided. Copyright © 2012 Magnolia Press.

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