应用土壤质地预测干旱区葡萄园土壤饱和导水率空间分布

田间表层土壤饱和导水率的空间变异性是影响灌溉水分入渗和土壤水分再分布的主要因素之一,研究土壤饱和导水率的空间变化规律,有助于定量估计土壤水分的空间分布和设计农田的精准灌溉管理制度。为了探究应用其他土壤性质如质地、容重、有机质预测土壤饱和导水率空间分布的可行性,试验在7.6 hm2的葡萄园内,采用均匀网格25 m×25 m与随机取样相结合的方式,测定了表层(0～10 cm)土壤饱和导水率、粘粒、粉粒、砂粒、容重和有机质含量,借助经典统计学和地统计学,分析了表层土壤饱和导水率的空间分布规律、与土壤属性的空间相关性,并对普通克里格法、回归法和回归克里格法预测土壤饱和导水率空间分布的结果进行了对比。结果表明:1)土壤饱和导水率具有较强的变异性,平均值为1.64 cm/d,变异系数为1.17;2)表层土壤饱和导水率60%的空间变化是由随机性或小于取样尺度的空间变异造成;3)土壤饱和导水率与粘粒、粉粒、砂粒和有机质含量具有一定空间相关性,而与土壤容重几乎没有空间相关性;4)在中值区以土壤属性辅助的回归克里格法对土壤饱和导水率的预测精度较好,在低值和高值区其与普通克里格法表现类似。研究结果将为更好地描述土壤饱和导水率空间变异结构及更准确地预测其空间分布提供参考。     

羊草对盐碱胁迫的生理生化响应特征

研究羊草对盐碱胁迫生理响应特征,旨在找出羊草耐盐碱范围及其对盐碱地改良的应用潜力。通过模拟5组不同盐碱梯度土壤胁迫试验(p H值为7.61、8.05、8.33、8.73、9.37,电导率为0.109、0.301、0.437、0.486、0.591 m S/cm),研究了羊草体内离子含量和运输能力、有机小分子渗透调节和保护酶活性变化。结果表明,盐碱胁迫由低到高,超氧化物歧化酶和甜菜碱在中度盐碱胁迫(p H值8.33,电导率0.437 m S/cm)积累最多,其他测定的耐盐碱物质,钠离子、脯氨酸、丙二醛、有机酸(草酸、柠檬酸、酒石酸)、过氧化物酶、过氧化氢酶、可溶性总糖、可溶性蛋白均呈直线增加。在盐碱胁迫条件下,羊草叶片中积累的钾离子、甜菜碱、有机酸、可溶性蛋白高于根茎,而脯氨酸、丙二醛、保护酶(超氧化物歧化酶、过氧化物酶、过氧化氢酶)、可溶性总糖叶片中含量低于根茎。根茎大量积累保护酶、脯氨酸及丙二醛有助于防止盐碱环境下根茎中膜过氧化,并保持根茎正常的渗透调节能力,从而有利于将K+等养分运送到叶片。在盐碱胁迫下,羊草叶片主要积累甜菜碱和有机酸进行渗透调节。该试验结果表明,羊草根茎和叶片在不同盐碱胁迫条件下各耐盐碱生理指标均产生一系列适应性反应,使其在盐碱环境正常生长,进而降低土壤盐碱性。该研究可为耐盐碱饲草选育及根茎型禾草改良盐碱化草地提供理论和实践依据。     

Nasopharyngeal tooth foreign body in a dog

An 8-year-old Shih-tzu dog was presented with a 2-week history of cough and nasal discharge. Upon presentation, the dog had constant open-mouth breathing with stertor and blood-tinged mucopurulent nasal discharge. Oral examination revealed a missing right mandibular second premolar tooth and severe periodontal disease. Computed tomography showed a radiodense, retropharyngeal foreign body. The foreign body was removed using caudal rhinoscopy. The foreign body was the right mandibular second premolar covered by thick calculus.     

Molecular epidemiology of rabies virus circulating in South Korea, 1998-2010

We analyzed the nucleotide sequences of the G-L (glycoprotein-large protein) intergenic non-coding region of 33 strains of the rabies virus (RABV) isolated in South Korea in 1998-2010 and compared the sequences with those of previously reported non-Korean strains. The similarities of the nucleotide sequences of the G-L region among all Korean RABV isolates ranged from 97.1 to 100%. Based on the phylogenetic analysis of the G-L region, the Korean RABV isolates were classified into three distinct subgroups with high similarity and were most closely related to the non-Korean NeiMeng1025C isolate, which was isolated from a rabid raccoon dog in eastern China, suggesting that the Korean RABV isolates originate from a rabid raccoon dog in northeastern Asia. Our results indicated that G-L region, as a useful phylogenetic indicator, is equivalent to the nucleoprotein (N) or glycoprotein (G) gene for study of RABV molecular epidemiology and that the Korean RABV isolates showing a few substitutions in the G-L region are continuously circulating in South Korea.     

Dimethylnitrosamine-induced liver fibrosis and recovery in NOD/SCID mice

There is a need for a new liver fibrosis model of immunodeficient mice to study the effects of cell therapy on liver disease because there are not many animal models available to study the effects of cell therapy. In this study, we induced liver fibrosis using dimethylnitrosamine (DMN) in NOD/SCID mice to create an animal model for liver disease. DMN (5 mg/kg, i.p.) was injected intraperitoneally for three consecutive days per week for 6 or 8 weeks, and the mice were sacrificed at weeks 0, 4 and 8 after the last DMN injection. The 6-week DMN-treated group gradually recovered from serum biochemical changes, histopathological toxic effects and lesions in the liver at weeks 4 and 8 after the last DMN injection. However, the progression of liver fibrosis and toxic levels were maintained in the 8-week DMN-treated group at week 4 after the last DMN injection. The increases in iron and extracellular matrix (collagen) in the DMN-treated group were confirmed by Prussian blue (PB) and Masson's trichrome (MT) staining, respectively. Additionally, activation of hepatic stellate cells was observed by alpha smooth muscle actin (α-SMA) immunostaining and western blot. In conclusion, treatment of NOD/SCID mice with 5 mg/kg of DMN for 8 weeks can be used to induce an appropriate animal model of disease for liver fibrosis. This model may be useful for evaluation of the efficacy and safety of cell therapies such as human mesenchymal stem cell therapy.     

发酵床养猪微生物降解系统调控研究

利用发酵床养猪,通过对圈舍垫料接种后的温度、湿度、各种酶活性、有机酸、无机氮、碳氮比（C/N比）各项指标的随时检测,并对发酵床进行日常管理,摸索出发酵床系统运转的规律,确定维持发酵床系统高效运转的评价指标,制定出其微生物降解系统的调控方法。     

A simple and efficient method for isolation of a single Eimeria oocyst from poultry litter using a micromanipulator

The chicken, which is the host for seven species of Eimeria, typically is infected simultaneously by multiple Eimeria species and the oocysts of coccidia are excreted in the feces. A prerequisite for investigation of individual Eimeria species is to isolate a single oocyst from fecal samples. A novel method for isolating a single Eimeria oocyst from poultry litter using a micromanipulator was developed. This simple method is fast and reliable, and provides direct isolation of a single sporulated oocyst from fecal samples harboring multiple Eimeria species or samples contaminated by other species of parasite.     

Expression of myeloperoxidase in swine influenza virus (SIV)-infected neutrophils in lungs from pigs experimentally infected with SIV subtype H1N2

The expression of myeloperoxidase (MPO) was examined in the swine influenza virus (SIV)-infected neutrophils in the lungs of pigs experimentally infected with swine influenza virus (SIV) subtype H1N2 by immunohistochemistry. Five pigs each from the infected and non-infected group were euthanized 1, 3, 5, 7, and 10?days post-inoculation (dpi). Immunohistochemical reactivity was mainly seen in neutrophils. The score for pulmonary histopathological lesions correlated with the score for MPO immunohistochemical reactivity (r ( s )?=?0.962, P?相似文献   

Reassortment among bovine, porcine and human rotavirus strains results in G8P[7] and G6P[7] strains isolated from cattle in South Korea

Group A rotaviruses (GARVs) cause severe acute gastroenteritis in children and young animals. Although zoonotic infections with bovine-like G6 and G8 GARVs have been reported in many countries, there is little evidence for reassortment between bovine GARVs and GARVs from heterologous species. The finding of bovine GARVs with the G6 and G8 genotypes in combination with the typical porcine P[7] prompted us to characterize all 11 genes of 30 bovine GARVs isolated from clinically infected calves. By the comparison of the full-length ORF of VP7 and NSP1-5, and the partial VP1-4 and VP6 nucleotide sequences between the 30 Korean and other known strains, three different genome constellations were found. Twenty seven strains showed the G8-P[7]-I5-R1-C1-M2-A1-N1-T1-E1-H1 genotypes, a single strain possessed the G6-P[7]-I2-R2-C1-M2-A1-N2-T1-E2-H1 genotype constellation and 2 strains the G6-P[7]-I2-R2-C2-M2-A3-N2-T6-E2-H3 genotype constellation. The complete genome of a single reference strains for each of these three genotype constellations (KJ25, KJ9-1 and KJ19-2) was determined and analyzed. A detailed phylogenetic analysis revealed a complicated picture, with several reassortments among bovine-like, porcine-like and human-like GARV strains, resulting in several different reassortant strains successfully infecting cattle.