用SSR标记提高水稻分子连锁图谱密度

本课题组利用圭630／台湾粳的DH群体，建立了一个水稻RFLP连锁图。该图谱含175个标记，总长1224．6cM，相邻标记间平均距离为7．0cM。但该图标记分布不够均匀，存在较多空白区，且在第4和第8染色体上分别存在一个断点。本研究试图在原有RFLP图谱的基础上，添加一些SSR标记，以使该图谱标记更加密集和均匀，并消除两个断点。共筛选了361对RM引物，获得了183对多态标记，在12条染色体上共整合了57个RM标记，染色体连锁图总长度为1811．2cM，比原图谱增长了47．9％，相邻标记间平均距离为7．8cM，与原图谱相近。不过，两条染色体上的两个断点仍无法消除，暗示这两个断点区域多态性较低或重组率较高。     

一张含有227个SSR标记的大豆遗传连锁图

利用由大豆主栽种晋豆23和农家种灰布支(ZDD2315)杂交培育的F10代大豆重组自交系群体Jinf,共474个家系作为作图群体。依据1999年Cregan等发表的大豆“公共图谱”,选用441对SSR引物,建成了含有227个SSR座位的大豆SSR连锁图,该图覆盖大豆基因组1900cM,两个相邻标记的平均间距为8．3cM,归属于20个大豆连锁群,与Song等2004年发表的公共图谱相比,所有标记都被定位于相同的连锁群,且排列顺序大致相同,具有很好的线性关系。     

Subthalamic GAD gene therapy in a Parkinson's disease rat model

The motor abnormalities of Parkinson's disease (PD) are caused by alterations in basal ganglia network activity, including disinhibition of the subthalamic nucleus (STN), and excessive activity of the major output nuclei. Using adeno-associated viral vector-mediated somatic cell gene transfer, we expressed glutamic acid decarboxylase (GAD), the enzyme that catalyzes synthesis of the neurotransmitter GABA, in excitatory glutamatergic neurons of the STN in rats. The transduced neurons, when driven by electrical stimulation, produced mixed inhibitory responses associated with GABA release. This phenotypic shift resulted in strong neuroprotection of nigral dopamine neurons and rescue of the parkinsonian behavioral phenotype. This strategy suggests that there is plasticity between excitatory and inhibitory neurotransmission in the mammalian brain that could be exploited for therapeutic benefit.     

节理对黄土破坏形态和力学性质的影响研究

黄土是一种具有多孔性和含有节理的土,节理的存在肯定会影响其力学性质。利用颗粒流软件,在Q3马兰黄土颗粒分析试验和物理力学实验结果的基础上,实现了黄土虚拟单轴压缩试验。在此基础上,设计了无节理和含30°、40°、50°、60°、70°、80°、90°节理等8种计算方案,经计算,分析了节理对黄土的破裂形态、裂纹数量、能量演化和应力应变曲线的影响,发现：节理角度接近黄土的剪切破裂角时,优势破裂面最明显,裂纹数量相对较低。破坏所需应变能较低,破坏最容易发生,此时承载性能最低。在实际工程中要避免黄土工程的坡面与剪切破裂角、节理面倾向成顺坡向夹角。     

New indicator for classification of agroclimatic conditions for the cultivation of catch crops

The realization of the benefits of stubble catch crops (CC) cultivated after the harvest of the main crop requires the ability to produce substantial amounts of biomass before the onset of winter. The growth and biomass production of CC is primarily determined by the time period of sowing and weather conditions of the site. The construction of a new indicator of agroclimatic conditions for the cultivation of CC is described. This indicator includes the possible time period for CC sowing according to the harvest time of the preceding main crop, temperature, and water conditions for emergence and growth. The termination of growth due to low temperatures is considered. The assumptions used for the construction of the indicator, and the relationships to CC biomass were validated with data from field experiments. The resulting maps of regions in the Czech Republic with similar indicator values for three groups of CC differing in temperature demands are shown.     

柑桔多胺代谢及其对生长结果调控的研究Ⅱ.果实成熟期多胺与水杨酸含量变化及其对耐贮性的影响

以Ｐｅｎｇ柑果实为试材,就果实成熟期及贮藏期内源多胺和水杨酸含量变化以及用多胺和水杨酸浸果的保鲜防腐效果进行了研究。结果表明,果实成熟期及贮藏的较高的多胺和水杨酸含量有利于采后贮藏保鲜;果实采后用１００ｍｇ／ｋｇ的腐胺、亚精胺、精胺或４００ｍｇ水处理处理,贮藏３个月后,腐烂率和失重率仅为对照的１／６￣１／２,其防腐保鲜效果以水杨酸和精胺最佳,其次为亚精胺和腐胺。     

Computed tomographical (CT) anatomy of the thoracoabdominal cavity of the male turkey (Meleagris gallopavo)

In the present work, our goal was to match high-resolution computed tomography (CT) scans with cross-sectional anatomical pictures of the turkey (Meleagris gallopavo). Two male BUT 6 (a commercial line) turkeys were used. CT scans with 1 mm slice thickness were performed. The images covered the trunk from the level of the 9th cervical vertebra to the end of the coccyx. The anatomical sections and the CT scans were matched, and the important structures were identified and labelled on the corresponding pictures. The aim of this study was to create a reference for evaluating CT scans of avian species.     

Variability in mixing efficiency and laboratory analyses of a common diet mixed at 25 experiment stations

An experiment involving 25 experiment stations in the North Central and Southern regions (NCR-42 and S-288, respectively) was conducted to assess the degree of uniformity of diet mixing among stations and to assess the variability among station laboratories in chemical analysis of mixed diets. A fortified corn-soybean meal diet was mixed at each station using a common diet formula (except for vitamin and trace-mineral additions). The diet was calculated to contain 14% crude protein (CP), 0.65% Ca, 0.50% P, and 125 ppm Zn (based on 100 ppm added Zn). After mixing, samples were collected from the initial 5% of feed discharged from the mixer, after 25, 50, and 75% was discharged, and from the final 5% of discharged feed. The five samples were sent to the University of Kentucky, finely ground, and divided into subsamples. Each set of five subsamples from each station was distributed to three randomly selected stations for analysis of CP, Ca, P, and Zn (i.e., each station analyzed five diet sub-samples from three other stations). In addition, two commercial and two station laboratories analyzed composites of the five subsamples from each of the 25 mixed diets. Based on the laboratories that analyzed all diets, means were 13.5, 0.65, and 0.52%, and 115 ppm for CP, Ca, P, and Zn, respectively. Ranges of 11.8 to 14.6% CP, 0.52 to 0.85% Ca, 0.47 to 0.58% P, and 71 to 182 ppm of Zn were found among the 25 diet mixes. The coefficients of variation among the 25 diet samples for CP, Ca, P, and Zn were 4.3, 9.3, 4.1, and 17.4%, and among the 25 laboratories were 3.6, 12.5, 10.7, and 11.1%, respectively. Overall analyses of the five sub samples were, respectively, CP: 13.4, 13.6, 13.4, 13.5, and 13.4% (P < 0.06); Ca: 0.66, 0.67, 0.67, 0.66, and 0.67%; P: 0.50,0.51,0.51,0.50, and 0.50%; and Zn: 115, 116, 112, 113, and 120 ppm (P < 0.001). Diets were not uniformly mixed at all stations (station x sample No. was P < 0.08 for Ca and P < 0.01 for CP, P, and Zn). Among stations, the range of the five samples, expressed as a percentage of the mean and averaged for CP, Ca, P, and Zn, varied from +/- 1.1% (i.e., 98.9 to 101.0%) to +/- 12.9% (84.6 to 110.4%), with an overall average of +/- 5.2%. Neither type nor volume of mixers was related to mixing uniformity. The results suggest that uniformity of diet mixes varies among experiment stations, that some stations miss their targeted levels of nutrients (especially Zn), and that the variability among experiment station laboratories in analysis of dietary Ca, P, and Zn in mixed diets is quite large.