夏闲期轮耕对小麦田土壤水分及产量的影响

2007-2010年在宁南旱区研究了夏闲期免耕/深松/免耕(T1)、深松/免耕/深松(T2)、连年翻耕(CT)3种耕作方式对麦田土壤水分及产量的影响.结果表明:经过3年夏闲期T1和T2处理后,农田土壤蓄水效率平均分别较连年翻耕处理提高15.2％和26.5％;T1和T2处理的降水潜在利用率较高,分别达到37.8％和38.5％,降水生产效率平均分别较连年翻耕处理提高9.9％和10.7％.夏闲期轮耕能显著降低休闲期的土壤无效蒸发,有效保蓄小麦生长期的土壤水分.在冬小麦生长前期,T1和T2处理0～200 cm土层土壤水分平均分别较连年翻耕处理增加6.8％和9.4％;在拔节-抽穗-灌浆期,与连年翻耕处理相比,两处理可显著提高0 ～ 200 cm土层土壤蓄水量,对作物产量的贡献率较高.不同轮耕模式在增加作物耗水量的同时也提高了作物产量及水分利用效率,与CT处理相比,3年T1和T2处理作物耗水量平均分别提高5.2％和6.1％,产量分别增加9.9％和10.6％,作物水分生产效率分别提高4.5％和4.3％.相关分析表明,在干旱缺水的宁南地区,冬小麦播种期、拔节-抽穗-灌浆期的土壤蓄水量可显著影响产量,尤其抽穗期的土壤蓄水量对产量的影响更大.     

另一种生态旅游 幸福农庄

幸福农庄位于台北县淡水镇与三芝乡交界处,是由黎旭瀛、陈惠雯夫妇带领会员、志工一同建立的"人与自然共生的教育基地",以推广"秀明自然农法"和"健康饮食教育"理念为目的。秀明自然农法又称"无肥料栽培",是一种提倡自耕自足的生活方式,作物栽培不加任何肥料甚至畜牧粪便,讲究食物均取之天然。其原理来自大自然:森林中的树木或路边的野草无人施肥,仍能生生不息;而田间的蔬菜正是过度地依赖外力,才失去从土地获取养分的能力。在陈慧雯夫妇的辛苦操持之下,"幸福农庄"的规模渐渐扩大,目前农产品有100多种稻米、芭蕉是主要     

全球旅游伦理规范核心理念摘要

◇坚信通过不同文化和生活方式的人们之间产生的直接的、自发的和平等的接触,旅游是推进和平的重要力量和增进世界人民之间的友谊和理解的重要因素;◇也坚信如果能够遵循一些基本原则和一定规则,负责任的和可持续的旅游与支持旅游部门企业运行的服务贸易自由化环境并不矛盾。     

不同加热方式对嗜肺军团菌环介导等温扩增检测法的影响

目的:研究不同的加热方式对嗜肺军团菌环介导等温扩增检测法的影响方法:用已知的13株嗜肺军团菌样本,采用空气浴、水浴和PCR仪同时进行环介导等温扩增,观察沉淀反应、荧光反应以及产物电泳结果。结果:水浴和PCR仪加热LAMP反应的沉淀产物较多,荧光反应较强,电泳检测结果较为明显。空气浴的3种检测结果均较弱。结论:采用水浴和PCR仪进行环介导等温扩增反应的效果较好,从仪器设备的成本及实验条件考虑,采用水浴是环介导等温扩增反应首选的加热方式。     

♀天生不同♂

网络上流传过这样一个笑话：一对夫妻，当丈夫因为喜欢的球队输掉比赛而郁闷时，他的沉默却令妻子辗转反侧一整夜，思前想后，不知婚姻哪里出了问题。虽然这是一个玩笑，却生动地反应出男女两性的不同。迟钝与敏感，粗心与细腻，沉默与喧闹……两性之间的思维、沟通、认知和反应究竟有哪些差别？又是什么原因造成了这些差别？     

Biological activities of purified harpin(Xoo) and harpin(Xoo) detection in transgenic plants using its polyclonal antibody

Many harpins have been found in plant pathogen bacteria that can elicit disease and insect resistance in plants, and promote plant growth. In this work, we overexpressed and purified Xanthomonas oryzae pv. oryzae harpin, harpinxoo, in Escherichia coli BL21/pGEX-hpa1. Harpinxoo was fused to the Cterminus of glutathione S-transferase （GST） and purified using the Bulk GST purification module and thrombin cleavage capture kit. Purified harpinxoo protein was sensitive to protease K and stable to heat treatment, and could not induce a hypersensitive response after treatment with various plant metabolic inhibitors; these characteristics were similar to harpinEa of Erwinia amylovora. The purified harpinxoo showed a similar ability to induce tobacco mosaic virus resistance in tobacco as harpinEa. Its antibody worked well in detecting the purified harpinxoo, harpinxoo in the total protein of E. coli BL21/pGEX-hpa1 and an hpal transgenic rice.     

A Lipidomic Study of the Effects of N-methyl-N＇-nitro-N-nitrosoguanidine on Sphingomyelin Metabolism

Systems biology is a new and rapidly developing research area in which, by quantitatively describing the interaction among all the individual components of a cell, a systems-level understanding of a biological response can be achieved. Therefore, it requires high-throughput measurement technologies for biological molecules, such as genomic and proteomic approaches for DNA/RNA and protein, respectively.Recently, a new concept, lipidomics, which utilizes the mass spectrometry （MS） method for lipid analysis,has been proposed. Using this lipidomic approach, the effects of N-methyl-N＇-nitro-N-nitrosoguanidine （MNNG） on sphingomyelin metabolism, a major class of sphingolipids, were evaluated. Sphingomyelin molecules were extracted from cells and analyzed by matrix-assisted laser desorption ionization-time of flight MS. It was found that MNNG induced profound changes in sphingomyelin metabolism, including the appearance of some new sphingomyelin species and the disappearance of some others, and the concentrations of several sphingomyelin species also changed. This was accompanied by the redistribution of acid sphingomyelinase （ASM）, a key player in sphingomyelin metabolism. On the other hand, imipramine, an inhibitor of ASM,caused the accumulation of sphingomyelin. It also prevented some of the effects of MNNG, as well as the redistribution of ASM. Taken together, these data suggested that the lipidomic approach is highly effective for the systematic analysis of cellular lipids metabolism.     

食物过敏婴儿和健康儿肠道菌群分析

目的检测食物过敏婴儿与健康婴儿的大便菌群,为食物过敏与肠道菌群关系的研究提供依据。方法以在重庆儿童医院体检的52例食物过敏婴儿和年龄、性别匹配的100例健康婴儿为研究对象,收集所有对象的新鲜粪便,采用直接快速涂片法分析肠道菌群。结果食物过敏婴儿革兰阳性杆菌比例降低,革兰阴性杆菌、革兰阳性球菌比例增高[(71.43±8.70)%vs(78.91±9.25)%,(15.69±6.26)%vs(11.85±6.66)%,(11.67±4.02)%vs(7.60±4.27)%,P均<0.001]。不同喂养方式下,食物过敏婴儿的大便菌群比例显示不同的改变,但革兰阳性杆菌比例降低是其共同的特点(P均<0.05)。结论食物过敏婴儿肠道菌群与健康婴儿的肠道菌群差异存在显著性。不同喂养方式的婴儿显示不同的大便菌群组成。肠道正常菌群的改变可能在食物过敏的发生中起一定作用。     

人体给药方式筛选药物是提高R＆D效率的最后王牌？

在药品的研究开发过程中,“0期临床试验”手法备受有关人士关注。欧洲已经完全解禁,美国FDA也于2005年4月份公布了有关指导方针（Guideline）的草案,日本也在解禁方面有了一些行动。[编者按]     

Nuclear Magnetic Resonance Studies on Huwentoxin-XI from the Chinese Bird Spider Ornithoctonus huwena： ^15N Labeling and Sequence-specific ^1H, ^15N Nuclear Magnetic Resonance Assignments

Huwentoxin-XI purified from the Chinese bird spider Ornithoctonus huwena is a toxin with both antiprotease activity and potassium channel blocking activity. To determine its solution structure, huwentoxin-XI was expressed in a yeast eukaryotic expression system and studied by NMR. The ^15N labeling strategy was used to facilitate the process of resonance assignments. The nearly complete sequence-specific assignments of proton and nitrogen resonances were obtained by analyzing a series of two-dimensional （2D） and three-dimensional （3D） spectra, including DQF-COSY, TOCSY, NOESY, ^15N-^1H HSQC, ^15N-^1H HNHA, ^15N-^1H HNHB, ^15N-^1H TOCSY-HSQC and ^15N-^1H NOESY-HSQC spectra. Secondary structure analysis of huwentoxin-XI showed that it mainly contains an N-terminal 310-helix from Thr3 to Arg5 and a C-terminal α-helix from Gln45 to Cys52, plus a triple-stranded antiparallel β-sheet of Glu18-Asn23, Thr26-Ile31 and Asn40-Lys41. These studies provide a solid basis for the final structure determination of huwentoxin-XI.