春季人为干扰活动对扎龙湿地鸟类群落结构影响的初步研究

根据扎龙湿地实际情况,将其划分为3种人为干扰强度地区,并进行了鸟类群落结构调查.统计3种干扰地区的物种丰富度,用Shannon-Winener指数计算物种多样性指数,用Pielou指数式计算物种均匀度指数,并用数量数据的β多样性测度公式分析人为干扰强度对扎龙湿地鸟类群落结构的影响.结果表明扎龙湿地鸟类的物种丰富度、物种多样性和物种均匀度与人为干扰强度成紧密的负相关关系.     

Attenuated Salmonella choleraesuis-mediated RNAi targeted to conserved regions against foot-and-mouth disease virus in guinea pigs and swine

In this study, specific sequences within three genes (3D, VP4 and 2B) of the foot-and-mouth disease virus (FMDV) genome were determined to be effective RNAi targets. These sequences are highly conserved among different serotype viruses based on sequence analysis. Small interfering RNA (siRNA)-expressing plasmids (p3D-NT19, p3D-NT56, pVP4-NT19, pVP4-NT65 and p2B-NT25) were constructed to express siRNA targeting 3D, VP4 and 2B, respectively. The antiviral potential of these siRNA for various FMDV isolates was investigated in baby hamster kidney (BHK-21) cells and suckling mice. The results show that these siRNA inhibited virus yield 10- to 300-fold for different FMDV isolates of serotype O and serotype Asia I at 48 h post infection in BHK-21 cells compared to control cells. In suckling mice, p3D-NT56 and p2B-NT25 delayed the death of mice. Twenty percent to 40% of the animals that received a single siRNA dose survived 5 days post infection with serotype O or serotype Asia I. We used an attenuated Salmonella choleraesuis (C500) vaccine strain, to carry the plasmid that expresses siRNA directed against the polymerase gene 3D (p3D-NT56) of FMDV. We used guinea pigs to evaluate the inhibitory effects of recombinant S. cho (p3D-NT56/S. cho) on FMDV infection. The results show that 80% of guinea pigs inoculated with 10⁹ CFU of p3D-NT56/S. cho and challenged 36 h later with 50 ID₅₀ of homologous FMDV were protected. We also measured the antiviral activity of p3D-NT56/S. cho in swine. The results indicate that 100% of the animals treated with 5 × 10⁹ CFU of p3D-NT56/S. cho were protected in 9 days.     

竹炭生产工艺的现状与建议

从生产竹炭的原料、设备、烧制工艺等方面分析入手，介绍了用竹材生产竹炭的整个生产工艺，并对生产中的一些问题提出自己的看法，为竹炭产品深度开发起到积极作用。     

基于GIS的扎龙保护区春季观鸟路线设计

2003年和2004年春季,在对扎龙保护区观鸟路线鸟类资源调查的基础上,运用GIS技术分析比较了3条观鸟路线的春季水鸟组成,有选择地对各种信息进行了采集、提供和分析,运用地理信息系统绘制了扎龙保护区观鸟路线图,并在3条观鸟路线上设置了最佳观测点。     

Characterization of 18 polymorphic microsatellite loci in the red‐crowned crane (Grus japonensis), an endangered bird

Red‐crowned cranes (Grus japonensis) were classified as an endangered species by the International Union for Conservation of Nature, but recently, their population has decreased dramatically. For the purpose of conserving this endangered species, 18 microsatellite markers were developed, including 12 newly isolated ones from a genomic library and 6 modified from another crane species. The markers were characterized in 26 red‐crowned cranes. As a result, these markers displayed 3–13 alleles, and the observed and expected heterozygosities ranged from 0.462 to 1.000 and from 0.483 to 0.884, respectively. The marker suite averaged 6.390 alleles per locus with an average polymorphic information content of 0.631. The combined exclusion probability (PE‐1) was 0.9985, and the combined exclusion probability (PE‐2) was 0.9999. Three of the 18 microsatellite loci presented significant deviations from Hardy–Weinberg Equilibrium (P < 0.05), likely due to sampling bias and unknown founder relatedness in a semi‐free population. Our results show that microsatellite loci can provide a standard protocol for genetic information in red‐crowned crane populations upon which strategies for effective conservation and management may be based.     

Prediction of the suitable distribution of Eucalyptus grandis in China and its responses to climate change

New Forests - Assessment of potentially suitable geographic areas in China and their response to climate change can provide a reference for sustainable development of Eucalyptus grandis...     

酶法提取制备烟草浸膏工艺优化

为了提高烟草浸膏中的还原糖和氨基酸含量,以红大碎片为原料,以还原糖得率和氨基酸得率为指标,在单因素试验的基础上采用L9(34)正交试验法对酶法提取制备烟草浸膏工艺进行优化。结果表明,酶法提取制备烟草浸膏较优工艺为:同时各添加原料质量0.2%的Viscozyme L复合水解酶、淀粉酶和风味蛋白酶,在40℃下水浴酶解4.0 h后,微沸提取0.5 h。采用该工艺制备得到的红大烟叶浸膏得率较常规提取增加了11.84个百分点,还原糖含量增加了36.46%,氨基酸含量增加了8.08%,致香成分总量增加了8.08%,其中含量增加较明显的美拉德反应产物是2-糠醛缩二乙醇、糠醛、5-甲基糠醛和吡咯,分别增加了204.07%、108.21%、92.28%和42.67%。     

城市野生动物与生态城市建设

城市发展过程中面临的困境引发了生态意识的觉醒,生态城市已成为现代国际城市发展的目标。“生态城市”建设模式的提出体现了人与自然和谐发展的科学发展观。城市野生动物是指生活在城区及其周边地区,并对人类活动产生了适应的野生动物。城市野生动物可以指示城市生态系统的健康状况,野生动物产业对城市社会经济的发展具有巨大的推动作用,同时城市中存在的野生动物也可以唤醒城市居民的生态意识,提高社会伦理道德水平。生态城市概念的提出将人与自然的关系提高到了一个新高度,同时也为城市野生动物的研究、管理工作提供了一个前所未有的发展机会。生态城市善待环境,崇尚自然的理念有助于提高人们的动物保护意识,从而提高城市野生动物管理水平。     

我国市售学生乳粉营养素含量分析

分析市售不同品牌学生乳粉的营养强化情况和能量及营养素含量分布。根据包装标示的营养成分表和食用方法计算出各产品每日可提供能量和营养素的量,与中国居民膳食营养素参考摄入量中学龄儿童人群的推荐量进行比较。结果表明：不同品牌学生乳粉VC、VE、VB6、叶酸、二十二碳六烯酸、膳食纤维和亚油酸含量差异较大,VA、VD、VC、牛磺酸和矿物质钙、铁、锌的强化比例超过2/3;以学生乳粉产品营养素含量的中位数计算,以7～10 岁男性学龄儿童为例,学生乳粉提供了需要量约12%的能量,约30%的蛋白质、VC、VD和铁,约40%的VB6、钙和锌以及近50%的VA和VB2。学生乳粉作为一种方便、易获得的乳制品,总体上有其营养优势。