A comparison of the pathogenicity of two strains of hog cholera virus: 1. Clinical and pathological studies

The virulence of a strain of hog cholera virus isolated during an outbreak of mild disease in pigs in New South Wales in 1960/61 (the NSW strain) was compared over 11 days with that of a virulent strain by inoculating 8 pigs with each virus and comparing the ensuing clinical signs and pathology. Both viruses caused persistent pyrexia and leukopenia, the NSW strain 4 to 5 days and the virulent strain 3 days, after inoculation. Few other clinical signs were observed in the pigs inoculated with the NSW strain. In contrast, all pigs inoculated with the virulent strain became progressively depressed and incoordinated, and were killed between days 6 and 9. Bronchopneumonia and swollen, reddened lymph nodes were observed in pigs inoculated with both viruses. Few other gross lesions were observed with the NSW strain, but some pigs receiving the virulent strain had pustules in the tonsil and the anterior oesophagus, petechial haemorrhages in the kidney, and small infarcts at the margins of the spleen. There were marked differences in the histopathology, both in the variety of organs affected and the severity of lesions in individual organs. Suppurative bronchopneumonia occurred in both groups. Other changes in the pigs affected with the NSW strain were colitis, mild cerebral vasculitis, necrosis, haemorrhage and neutrophil infiltration in some lymph nodes and spleens. In pigs infected with virulent virus the cerebral vasculitis was so severe that there was necrosis of cells within the vessel walls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of the residual virulence of Newcastle disease vaccine strains V4, Hitchner Bl and La Sota

The clinical response of 7-day-old chickens to Newcastle disease vaccine strains V4, B1 and La Sota administered by the aerosol method was used to study the residual virulence of the strains. Parameters used to assess the severity of the clinical response were the number of sneezes recorded and the weight gain of chickens in the 10 day test period. The demeanour of the chickens was also observed.
Strain V4 was less pathogenic for chickens than strain B1 which was less virulent than strain La Sota. Statistically significent differences were recorded in weight gain and the number of sneezes detected in each group. An unexpected mild respiratory disease recorded in chickens dosed with strain V4 may have been associated with administration of virus as a fine particle aerosol. Aust. vet. J. 61: 47–49     

Susceptibility of cats to equine morbillivirus

Objective To assess the susceptibility of cats to equine morbillivirus (EMV) by direct administration of the virus by subcutaneous, intra-nasal or oral routes, and following exposure to infected cats.
Design A disease transmission study, with controls, using ten cats.
Procedure Groups of cats were given the virus by the designated methods and assessed for evidence of infection by clinical examination, plus pathological and virological tests.
Results All cats administered the virus by subcutaneous, intra-nasal or oral routes became infected and developed the disease within 4 to 8 days. One of two cats in contact with affected cats also developed the disease, but two cats kept near to affected cats did not become infected. The virus was isolated from a range of tissues collected from the infected cats, and the lesions observed in affected cats were similar to those previously observed in horses naturally and experimentally infected with the virus.
Conclusion This is the first demonstration that animals can be infected with EMV by non-parenteral means, that the virus can transmit naturally between animals and confirms other reports of the similarity of EMV disease in horses and cats.     

草坪草种(品种)的筛选及利用

以绿色期、质量、抗逆性及建植效率为指标 ,对国内外的优良草坪草进行了引种筛选工作。筛选出了适宜内蒙古气候条件的 9个品种 ,培育出了冷季型草坪草品种—大青山草地早熟禾。同时对优良的地被植物进行了引种驯化     

烷基锡酸催化松香酯化反应的研究

以松香树脂酸的酯化反应为例，研究了烷基锡酸为酸化反应的催化作用，系统的探讨了影响反应的各种因素，研究表明烷其锡酸具有很高的催化活性，可以高效地催化合成系列松香酯，大大缩短了反应时间。     

都市型薄皮甜瓜品种比较试验

为筛选出适宜在北京种植的优质都市型薄皮甜瓜品种,选取8个品种的薄皮甜瓜为试验材料,对比分析其田间长势及果实品质。结果表明:8个参试品种田间长势及果实品质均有显著差异,其中梨形瓜中丘比特果实大,外观好,果肉最厚,心糖最高,综合果实品质最优秀;长筒形瓜中博洋9号果实外观及品质较优秀,单果质量最大,果形指数好,心糖最高。综合看来,丘比特和博洋9号这2个品种可在北京地区进一步推广种植。     

富含硒钴锌的苜蓿青干草在牛羊饲喂中的效果

通过在荷斯坦奶牛和杜泊羊日粮中添加5%高硒型、高硒钴型、高硒钴锌苜蓿青干草,研究3种苜蓿青干草对牛羊饲料转化和生产特点的影响。结果表明,功能型苜蓿青干草能够显著提高牛羊的饲料转化率,其中高硒钴和高硒钴锌苜蓿青干草有利于提高羊和牛的日增重,而高硒型青干草有利于提高荷斯坦奶牛的产奶量。     

Frequency Hydraulic Aperture about Fracture Seepage in Rock Mass

The frequency aperture given in this paper is a new method that describes the fracture aperture composition. The aperture curve plays a role in describing the aperture distribution and uniformity. In particular, the frequency hydraulic aperture is of great importance in seepage analysis. It overcomes limitations of hydraulic aperture and mean aperture. Based on existing information, the result of example calculation shows that the hydraulic aperture e h equals to the median aperture e 50 . This paper also obtains that the frequency hydraulic aperture e sh equals to e 48 through finite element numerical modeling for various type of random fracture.     

Connect Technique of Laminated Object Manufacturing Using Metallic Materials as Modeling Materials

To solve some key problems existed in the manufacturing of metallic functional part via Laminated Object Manufacturing (LOM), a new technique using vacuum solid-state pressure diffusion weld technique to connect the metallic slice sheets is presented in this paper. The following conclusions can be draw from the experiments introduced specially: the size in the stack direction shrink at the rate of less than 1% and the shrinking is owed to regularly error, the atom-diffusion between two combined interface occurred clearly and new crystallites shaped meanwhile, shearing intension of well connected diffusion section is more than 100 MPa and micro hardness of well-knit portion is the same to matrix's. It can be proved from the result above that the vacuum solid-state pressure diffusion technique weld is a perfect technique for connecting metallic slice sheets used in the manufacturing of metallic functional part via LOM.     

糖水龙葵果罐头制作工艺研究

通过单因素多水平、多因素多水平的正交实验对龙葵果实罐藏工艺进行研究,结果表明,加工条件为烫漂温度60℃,烫漂时间10min,糖水浓度60%,排气温度40℃,排气时间15min.在此条件下罐头产品感官与品质最佳.