推动林业科学发展确保实现“双增”目标——东北林业大学帽儿山实验林场实现“双增”目标的探讨

东北林业大学帽儿山实验林场依靠东北林业大学为科技支撑，建场以来，尤其是改革开放以来，科学研究有了长足发展，取得了一系列科研成果。通过科学经营，森林面积和林分蓄积量实现了双增长。帽儿山实验林场将以科学发展观为指导，以兴林富民为宗旨，坚持实事求是，依靠群众，科学采伐，把林场建设成为环保、文明、现代化的生态林场，真正实现林业的“双增”目标。     

The efficacy of valnemulin (Econor) in the control of disease caused by experimental infection of calves with Mycoplasma bovis

Mycoplasma bovis infection was experimentally induced in groups of six young calves. A further group was uninfected and served as a control. Ten days after infection, medication with either enrofloxacin (Baytril, Bayer) or valnemulin (Econor, Novartis) was instituted via the milk replacer for a further 10 days, after which all calves were killed. Infection resulted in depression, pyrexia, inappetance and prominent respiratory signs. Arthritis occurred in two animals and two (unmedicated) animals died. At post-mortem examination extensive lesions were present in the lungs and M. bovis was re-isolated from infected unmedicated calves' lungs. Medication with either enrofloxacin or valnemulin resulted in a rapid diminution of clinical signs, restoration of appetite and reversal of weight loss. Isolation of Pasteurella multocida from the calves' lungs was suppressed by both medicaments. Valnemulin resulted in a more rapid reduction of clinical scores and eliminated M. bovis from the lungs more effectively than enrofloxacin.     

Epidemic West Nile virus encephalomyelitis: a temperature-dependent, spatial model of disease dynamics

Since first being detected in New York in 1999, West Nile virus (WNV) has spread throughout the United States and more than 20,000 cases of equine WNV encephalomyelitis have been reported. A spatial model of disease occurrence was developed, using data from an outbreak of serologically confirmed disease in an unvaccinated population of horses at 108 locations in northern Indiana between 3 August and 17 October 2002. Daily maximum temperature data were recorded at meteorological stations surrounding the study area. The distribution of the total number of degree-days elapsing between July 4 and the date of diagnosis of each case was best described by a normal distribution (mean = 5243 °F, S.D. = 1047). The days on which the average risk was >25, >50 and >75% were predicted (versus observed) to occur on August 23 (August 9), August 31 (September 2) and September 9 (September 9). The epidemic was predicted to occur 3 days earlier, or 4 days later, than observed if temperatures in the study area were uniformly increased, or decreased, by 5 °F, respectively. Maps indicated that WNV encephalomyelitis risk always remained greater in the northwest quadrant of the study area. Since WNV might exist at a hypoendemic level of infection, and occasionally re-emerge as a cause of epidemics in equine populations, by identifying factors that contributed to this epidemic, the potential impact of future epidemics can be reduced. Such studies rely on a GIS framework, availability of meteorological and possibly remotely sensed data and information on host and landscape factors. An early-warning system for WNV transmission in equine populations could be developed.     

The function of Fas,FasL and Bcl-2 in the pathogenesis of autoimmune thyroid disorders

AIM: To investigate the expression and function of apoptosis-related protein, Fas, FasL, and Bcl-2 in the pathogenesis of autoimmune thyroiditis. METHODS: Immunohistochemical staining was performed on 20 Hashimoto's thyroiditis (HT), 20 Graves' disease (GD), and 20 thyroid follicular adenoma (TFA, as control).RESULTS: All the cases expressed Fas, mainly on the cell surface and cytoplasm. FasL was found in all except 3 of the TFA. Bcl-2 in 15 of HT, 19 of GD, 17 of TFA. In TFA follicular cells expressed moderate Fas and minimal or absent FasL. In HT, follicles adjacent to infiltrating lymphocytes showed a increased levels of Fas and FasL, but infiltrating lymphocytes exhibited weaker staining of Fas and FasL than thyrocytes. In GD, thyrocytes and lymphocytes showed nearly similar Fas with HT, but rather weaker for FasL than HT. Bcl-2 was nearly similar in GD and TFA, but follicular cells in vicinity of lymphocytes and lymphocytes located in germinal centers of HT tissues exhibited significantly weaker. CONCLUSION: The expression of Fas, FasL and Bcl-2 in Hashimoto's thyroiditis and Graves' disease was nearly similar. Strong FasL expression and weak Bcl-2 expression on the follicles in HT may induce apoptosis. These results provide further proof that the functions of Fas and its ligand and Bcl-2 may play an important part in the pathogenesis of autoimmune thyroid diseases. The lymphocytes do not seem to be directly engaged in the process with their own FasL, but they may provide some cytokines that , in turn , up-regulates Fas and/or FasL leading to apoptosis.     

温度对圆尾肖蛸实验种群增长的影响

本文根据圆尾肖蛸(Tetragnatha vermi formis Okuma 1982)在六种恒温条件下的发育历期,幼蛛存活率、成蛛产卵率、产卵量和孵化率,组建了圆尾肖蛸在不同温度条件下的实验种群生命表。结果表明,在29℃的恒温条件下,圆尾肖蛸的种群增长指数最大,为51.71;高温35℃种群增长指数最小为11.70。温度与种群增长指数的关系可用以下方程表述:y=443.2383-36.5959x~2+0.7970x~2(20≤x≤29)。y=1275.3143-71.6280x+1.0150x~2(29≤x≤35)。(x=温度,y=种群增长指数)     

Experimental tuberculosis in the European badger (Meles meles) after endobronchial inoculation with Mycobacterium bovis: II. Progression of infection

The aim of the study was to describe, over a period of 24 weeks, the pathological and bacteriological changes in badgers experimentally infected with Mycobacterium bovis. The badgers were infected by endobronchial instillation of 2.5 × 10⁴ colony forming units (cfu) M. bovis. After infection, the badgers were examined at 3 weekly intervals when blood and tracheal aspirates were collected. At 6, 12, 18 and 24 weeks post-infection (pi) three animals were euthanized and a detailed pathological and bacteriological examination was performed to assess the nature of the experimental disease. During the course of the study only one badger developed clinical signs of disease: a subcutaneous swelling on its head, first observed at 18 weeks pi. At post-mortem examination gross and histological lesions of tuberculosis were observed and M. bovis was recovered from all, except one badger. In the majority of badgers the endobronchial route of inoculation resulted in the establishment of infection that over 24 weeks was non-progressive with limited dissemination of infection from the thoracic cavity, mainly to the hepatic and mesenteric lymph nodes. However, in one of the badgers examined at 18 weeks pi and one at 24 weeks pi, infection was widely disseminated. The disease induced by the endobronchial inoculation displayed the characteristics of disease observed in naturally infected badgers.     

草原放牧系统持续管理试验研究:试验设计及放牧率对草-畜系统影响分析

在内蒙古典型草原区中国科学院草原生态定位站研究不同放牧率、放牧方式和放牧季节对草原植物和家畜生产的影响。结果表明,地上现存量随着放牧率的增加而降低,但达到峰值的日期提前了。地上生物量与放牧率无明显趋向性变化。家畜增重随着放牧率的增大而下降,公顷总增重与放牧率成二次曲线关系。将放牧率对草原生产力的动态确定为可持续放牧率和改良放牧率。     

农学专业实验实践教学改革的探索与实施——以延边大学农学院为例

本文以延边大学农学院农学专业为例,对相关实验实践教学现状进行分析的基础上,指出了存在的问题,总结了实验实践教学改革的实施与效果。通过改革实践,取得了良好的效果,极大地提高了实验教学的质量与水平。     

黄蔷薇嫩枝扦插育苗技术试验研究

黄蔷薇嫩枝扦插育苗的成活率受很多因素的影响。通过试验研究表明,在以蛭石为扦插基质,用IAA、IBA、NAA处理插穗时,以IBA30mg/L,NAA20mg/L的浓度成活率较高,扦插后,加强扦插苗的水分、光照、温度、病害和施肥管理,可以进一步促进插穗的生根和生长。     

食品工艺学导论课程的教学改革与实践

从食品工艺学导论课程的教学条件、理论教学方法和实验教学模式等方面进行了教学改革。结果表明,修订的教学大纲、自编的实验教程和省级重点实验室的使用改善了教学条件,保证了教学活动更好地开展;理论教学的改革增加了学生的积极性和参与度,学生的食品安全意识和职业道德得到加强,生产实习环节提高了学生理论联系实际的能力;以"学生为主导"的实验教学模式同时锻炼了学生基本技能和综合实验设计的能力,使独立完成实验任务的学生比例从50%提高到了80%。改革后的课程教学使学生能更好地掌握课程内容,为学生后续课程的学习奠定了基础,新的课程教学方式可以为其他高等院校在食品加工、保藏方向的教学模式提供参考。