杂交狼尾草对草鱼肉脂肪酸组成的影响

实验表明,在配合饲料和杂交狼尾草比例为11(干物质比例)条件下养殖的草鱼与全配合饲料养殖的草鱼在背肌脂肪酸组成的对比中,饲草鱼多不饱和脂肪酸(PUFA)的相对含量为(40.18±1.36)%,是饲料鱼(21.64±0.9g)%的1.86倍.饲草鱼n-3 PUFA的相对含量为(14.72±1.27)%,是饲料鱼(2.43±0.49)%的6.06倍.其中,最明显的是饲草鱼183n-3的相对含量(10.27±1.21)%是饲料鱼(1.01±0.02)%的10.17倍.实验也对比了杂交狼尾草叶片与饲料脂肪酸组成的差异.发现在杂交狼尾草(叶片)的脂肪酸组成中183n-3的含量高达(66.23±0.16)%.而在饲料中183n-3的含量仅为(4.34±0.03)%.杂交狼尾草和饲料中未检测到EPA和DHA.草鱼利用杂交狼尾草中丰富的183n-3生物转化生成了EPA和DHA,从而显著提高了饲草鱼鱼肉中n-3 PUFA的含量,促进草鱼生长发育、提高抗病能力,改善鱼肉品质.     

沿海城市耕地数量变化及其驱动力研究——以辽宁省葫芦岛市为例

介绍了1998～2007年中国10个主要沿海城市的耕地数量变化情况及其驱动力,认为经济发展和人口增长是导致沿海城市耕地减少的共同驱动力,其中经济发展是最主要的驱动因素。以辽宁省葫芦岛市为例,根据1998～2007年相关统计数据,运用主成分分析法研究了葫芦岛市耕地面积变化的驱动因子。结果表明,近10年来,葫芦岛市的耕地总量不减反增,耕地面积增加主要集中于1998～2002年;葫芦岛市耕地数量变化的驱动力可以归纳为经济发展、人口增长及农业科技进步三大类。基于此,提出了耕地保护的相关对策：控制人口数量,减轻耕地压力;加强耕地和基本农田保护,稳定耕地数量和质量;严格控制耕地非农化规模,提高土地节约和集约利用水平;加大土地整理、复垦和开发力度;加大农业科技投入,引导农业结构调整。     

中国沿海河口地区鳗苗的群体生态和群体结构

本报道了１９９２－１９９５年间对中国沿上代表性河口鳗苗的群体生态（包括溯河的生态条件，日龄生长、食性、对温度和盐度变化的适应力、耗氧率、室息点、耐铠力）和群体结构（全长、体重和日龄结构）的研究结果。     

黄山市“油蔬两用”油菜品种筛选

为筛选适宜黄山地区应用推广的“油蔬两用”油菜品种,对13个双低甘蓝型油菜品种的菜薹产量、菜籽产量、主要性状及经济效益进行比较分析。结果表明：‘皖油28’菜薹口感甜脆爽口、菜籽产量高,‘同油杂2号’菜薹产量与总产值高,二者可作为高产型“油蔬两用”油菜品种推广应用;‘蓉油16’与‘华油杂62’的菜薹、菜籽产量与总产值较高,可作为“油蔬两用”配套品种。     

Mathematical Medel for Heat Transfer on Solididing Ladle of Hot Metal

In this paper,solidifinG ladle of hot metal has been studied from the point ofview of heat transfer.A mathematical model,which is applied to predict the shape and the thicknessof solidifing layer,has been developed. The theoretical calculated results agree with the appliedresults in preduction. The effects of various paramenters,such as the circulating times, the inner-surface temporature of ladle and the different refractories,on the shape and the thickness ofsolidifing layer have been discussed.These are contributed to reduce the solidifing ladle of hot metal.     

兰科植物内生真菌对其宿主植物生理效应研究

本文主要论述兰科植物内生真菌及其内生真菌对宿主植物的入侵生理生态效应，包括促进宿主植物生长，提高宿主植物的抗逆性以及诱导子效应和微生态效应，并探讨内生真菌在兰科植物生产应用和科学研究的方向。     

特早熟扁豆新品种‘湘扁豆1号’

 ‘湘扁豆1 号’为特早熟扁豆新品种, 鲜荚上市比常规品种早95 d 以上, 商品性好, 质脆嫩, 品质优; 植株生长势强, 能密植高产, 产量高达42 000 kg/ hm² ; 抗病性强, 较耐寒, 适宜长江中、下游及以南地区作特早熟品种栽培。     

南方地区杨树胶合板材定向培育技术的研究

随着工业技术的发展,工业生产对木材和其它林产品提出了更高、更新的要求,要求各类用材实行定向培育,这是世界人工林发展出现的战略变化１）。杨树具有生长快、成材早、产量高和易于更新的特点,为最适的短轮伐期工业用材林经营树种（方升佐等,１９９３）。所谓定向培育,是指按最终用途所确定的对木材原料的要求,采用集约经营等科学管理措施,生产出种类、质量、规格都大致相同,价格具竞争力的大批木材原料。本文简要总结了南方地区杨树胶合板材定向培育技术中关于无性系选择、立地控制、密度控制、栽植材料选择及优化栽培模式等研究…     

HSP90 gene expression induced by aspirin is associated with damage remission in a chicken myocardial cell culture exposed to heat stress

1. To understand the potential protection of heat shock protein 90 (HSP90) induced by aspirin against heat stress damage in chicken myocardial cells, enzyme activities related to stress damage, cytopathological changes, the expression and distribution of HSP90, and HSP90 mRNA levels in the myocardial cells exposed to heat stress (42°C) for different durations with or without aspirin administration (1 mg/ml, 2 h prior) in vitro were investigated.

2. Significant increase of enzyme levels in the supernatant of heat-stressed myocardial cells and cellular lesions characterised by acute degeneration, karyopyknosis and karyorrhexis were observed, compared to non-treated cells. However, the lesions of cells treated with aspirin were milder, characterised by earlier recovery of enzyme levels to the control levels and no obvious heat stress-related cellular necrosis.

3. Stronger positive signals in the cytoplasm and longer retention of HSP90 signal in nuclei were observed in aspirin-treated myocardial cells than those of only heat-stressed cells. HSP90 level in the aspirin-treated myocardial cells was 11.1-fold higher than that in non-treated cells, and remained at a high level at the early stage of heat stress, whereas it was just 4.1-fold higher in only heat-stressed cells and returned rapidly to a low level.

4. Overexpression of HSP90 mRNA in aspirin-treated cells was observed throughout the experiment, whereas HSP90 mRNA decreased significantly only in heat-stressed cells.

5. The early higher HSP90 expression induced by aspirin during heat stress was accompanied by decreased heat stress damage, suggesting that aspirin might play an important role in preventing myocardial cells from heat stress damage in vitro.

     

Free choice feeding of whole grains in meat-type pigeons: 1. effect on performance,carcass traits and organ development

1. The effects of 5 different feeding systems on the performance, carcass traits and organ development were studied in pigeon squabs.

2. The 5 treatments were (1) whole grains of maize, pea and wheat plus concentrate feed; (2)whole grains of maize and wheat plus concentrate feed (CWC); (3) whole grains of maize and pea plus concentrate feed; (4)whole grain of maize plus concentrate feed (CC); and (5) compound feed (CF).

3. Feed intake of parent pigeons increased significantly from 0 to 21 d and it was higher in the CF treatment. Body weight of squabs in the CWC treatment was the highest among the 5 treatments in 4 weeks. Body weight losses of parental pigeons during the rearing period were not significantly different among the 5 treatments.

4. Protein intake in CC and CWC treatments was lower than that of the other three treatments. The CWC treatment had the highest daily weight gain and the lowest feed conversion ratio. Treatments were statistically similar in the relative weight of carcass, breast and thigh. CF had the lower relative weight of abdominal fat.

5. Relative weight of gizzard in the CF treatment was significantly lower than that of CWC.

6. It was concluded that the application of free choice feeding of whole grains of maize and wheat plus concentrate feed increased the body weight of 28-d-old pigeon squabs and decreased the feed conversion rate of parent pigeons. This feeding strategy could be commercially interesting in meat-type pigeon production.