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701.
Evaluation of the water-quality dynamics in a eutrophic agricultural pond by using a one-box ecosystem model considering several algal groups 总被引:1,自引:1,他引:0
The Okubo pond is an agricultural pond located in the Itoshima area of Fukuoka Prefecture, Japan. It was constructed for irrigating
a nearby cultivated area. A monitoring program from August 11 to November 26, 2008, suggested the risk of eutrophication in
the water body. The high total nitrogen concentration (1.34 mg/l), high total phosphorus concentration (0.06 mg/l) and extreme
oxygen depletion (2 mg/l on 5 November 2008) exceeded the Japanese standards for paddy irrigation water. Furthermore, luxuriant
algal blooming in October indicated a hypereutrophic status according to the OECD (1982) criteria. In this study, a one-box ecosystem model was developed to obtain an insight into the seasonal variations in the
algal concentrations and chemical components of the Okubo pond with the aims of protecting its aquatic ecosystem and maintaining
its water quality. The model was based on a completely mixed system and included 12 water-quality indices: green algae, blue-green
algae, diatoms and dinoflagellates, cryptophytes, zooplankton, particulate organic matter, dissolved organic matter, phosphate–phosphorus,
ammonia–nitrogen, nitrite–nitrogen, nitrate–nitrogen, and dissolved oxygen. The monitoring data were used to verify the model
simulation. Model evaluation suggested good agreement between the predicted and the observed data for the seasonal variations
in the algal, nutrient, and dissolved oxygen concentrations. To determine the sensitivity of the model parameters, a sensitivity
analysis was conducted leading to the conclusion that the optimal temperature, growth rate, and respiratory rate of the four
algal groups, especially the ideal temperature for blue-green and green algae are the most influential factors determining
the variability affecting the model inference. From the model simulation, the water temperature and nutrient concentration
were considered to be the key limiting factors controlling alternative algal blooms in this period. 相似文献
702.
703.
Teck C. LOH Nguyen T. THANH Hooi L. FOO Mohd HAIR‐BEJO Bin K. AZHAR 《Animal Science Journal》2010,81(2):205-214
The effects of feeding different dosages of metabolite combination of L. plantarum RS5, RI11, RG14 and RG11 strains (Com3456) on the performance of broiler chickens was studied. A total of 504 male Ross broilers were grouped into 7 treatments and offered different diets: (i) standard corn‐soybean based diet (negative control); (ii) standard corn‐soybean based diet +100 ppm neomycin and oxytetracycline (positive control); (iii) standard corn‐soybean based diet + 0.1% metabolite combination of L. plantarum RS5, RI11, RG14 and RG11 strains (Com3456); (iv) standard corn‐soybean based diet + 0.2% of Com3456; (v) standard corn‐soybean based diet + 0.3% of Com3456 (vi) standard corn‐soybean based diet + 0.4% of Com3456 and (vii) standard corn‐soybean based diet + 0.5% of Com3456. Supplementation of Com3456 with different dosages improved growth performance, reduced Enterobacteriaceae and increased lactic acid bacteria count, and increased villi height of small intestine and fecal volatile fatty acid concentration. Treatment with 0.4% and 0.2% Com3456 had the best results, especially in terms of growth performance, feed conversion ratio and villi height among other dosages. However, the dosage of 0.2% was recommended due to its lower concentration yielding a similar effect as 0.4% supplementation. These results indicate that 0.2% is an optimum level to be included in the diets of broiler in order to replace antibiotic growth promoters. 相似文献
704.
Kim Anh Thi Nguyen Chuong N.P.T. Bui Trang T. H. Le 《Aquaculture Economics & Management (Blackwell Science)》2016,20(1):82-108
Research results on the effects of aquaculture on poverty alleviation have been mixed. We use Tobit, simulation models and cross sectional survey data of 285 households, in Ben Tre Province, Vietnam, to evaluate the effects of aquaculture involvement on poverty, measured using per capita consumption of less than $1.25 USD, $1.50, and $2.00 per day. The results show for per capita consumption of less than $1.25 per day that households’ aquaculture participation or productivity had no or little effect on the living standard. For income levels above $1.25 per capita per day aquaculture participation or productivity influenced the standard of living. 相似文献
705.
706.
This field trial was conducted to determine whether 40 or 75 mg/kg of praziquantel is suitable for treatment of fishborne zoonotic trematodes (FZT) in naturally infected dogs (n=10) and cats (n=11). Three days after treatment all animals at either dose were negative for small trematode eggs. In two cats and one dog treated with 75 mg/kg, however, a few damaged eggs were found 3 days post-treatment; no small trematode eggs were seen in these animals at day 14 post-treatment. In addition, at the 75 mg dose, two cats and two dogs experienced vomiting or diminished appetite. Therefore a praziquantel dose of 40 mg/kg is suggested for treatment of FZT in dogs and cats. 相似文献
707.
Escherichia coli strains causing edema disease in northern Vietnam share an identical verotoxin 2e 总被引:1,自引:1,他引:0
Oanh Thi Kim Nguyen Nguyen Viet Khong Do Thuy Ngoc Goddeeris Bruno Maria De Greve Henri 《Tropical animal health and production》2010,42(8):1797-1804
Edema disease (ED) is a common fatal disease in newly weaned piglets. To develop an effective control program for ED, we carried
out a study to better understand the incidence and spread of the disease and the characteristics of the causative agent. In
our study, 69 Escherichia coli strains, isolated from 92 piglets showing clinical signs of ED from 13 provinces in northern Vietnam, were positive for both
the VT2e toxin and the F18 major fimbrial subunit gene fedA. Of these, 40 strains (58%) were positive for AIDA and 16 isolates carried one or more enterotoxins. Forty-six (67%) of the
69 VT2e+/F18+
E. coli isolates belonged to classical serotypes (O139:K82, O141: K85, O138:K81, and O149:K91) while the remaining strains did not
belong to the common serotypes in pig. Seropathotype 0139:K82+/VT2e+/F18+/AIDA+ (21 isolates) was the most frequently detected ED-causing E. coli strain. High prevalence of resistance was observed to the common drugs of tetracycline, streptomycin, trimethoprim/sulfamethoxazole,
amoxicillin/clavulanic acid, and spectinomycin. Multiple resistances were widely distributed with 84% of isolates resistant
to five antibiotics. Sequence analysis demonstrated that the VT2e toxin is identical among E. coli strains causing ED in pig. 相似文献
708.
S. Avendano D. A. Emmerson W. M. Muir T. Nguyen W. J. Kuenzel A. Jurkevich P. B. Thompson 《中国家禽》2010,32(5)
<正>1遗传育种与家禽福利的关系腿畸形、骨骼缺陷、代谢失调等动物福利性状是育种工作者长期以来重点考虑的问题。这些问题由于其较低的遗传力以及与肉鸡生产性状的负相关性是育种工作的一大挑战。安伟捷公司自20世纪90年代早期就将福利性状囊括在育种目标之内,在骨骼和代谢方面取得了较大的进展。将福 相似文献
709.
Phuong Thi Hang Nguyen Olga Vinnere Pettersson Peter Olsson Erland Liljeroth 《European journal of plant pathology / European Foundation for Plant Pathology》2010,127(1):73-87
Twenty-three isolates of Colletotrichum gloeosporioides, five isolates of C. acutatum, two isolates of C. capsici and six isolates of C. boninense associated with anthracnose disease on coffee (Coffea spp.) in Vietnam were identified based on morphology and DNA analysis. Phylogenetic analysis of DNA sequences from the internal
transcribed spacer region of nuclear rDNA and a portion of mitochondrial small subunit rRNA were concordant and allowed good
separation of the taxa. We found several Colletotrichum isolates of unknown species and their taxonomic position remains unresolved. The majority of Vietnamese isolates belonged
to C. gloeosporioides and they grouped together with the coffee berry disease (CBD) fungus, C. kahawae. However, C. kahawae could be distinguished from the Vietnamese C. gloeosporioides isolates based on ammonium tartrate utilization, growth rate and pathogenicity. C. gloeosporioides isolates were more pathogenic on detached green berries than isolates of the other species, i.e. C. acutatum, C capsici and C. boninense. Some of the C. gloeosporioides isolates produced slightly sunken lesions on green berries resembling CBD symptoms but it did not destroy the bean. We did
not find any evidence of the presence of C. kahawae in Vietnam. 相似文献
710.
Nguyen VT Darbour N Bayet C Doreau A Raad I Phung BH Dumontet C Di Pietro A Dijoux-Franca MG Guilet D 《Fitoterapia》2009,80(1):39-42
Bio-guided fractionation of the roots of Paris polyphylla (Trilliaceae), based on inhibition of P-glycoprotein-mediated daunorubicin efflux in K562/R7 cell line, led to isolation and identification of the three saponins 3-O-Rha(1-->2)[Ara(1-->4)]Glc-pennogenine, gracillin and polyphyllin D, and the two ecdysteroids 20-hydroxyecdysone and pinnatasterone. These compounds were tested for multidrug reversion on P-glycoprotein (ABCB1) with both drug-selected and transfected cell lines, and also on Breast Cancer Resistance Protein (BCRP/ABCG2). By contrast to a weak efficiency on BCRP, the three saponins displayed significant effects as inhibitors of P-glycoprotein-mediated drug efflux. 相似文献