甘蔗中膜拱架冬育春移试验研究

本试验于1993年11月在本县枧头乡开展小面积甘蔗中膜拱架冬育春移试验研究，试验结果如下：（1）有效地提高膜内气温、土温和土壤湿度，出苗早；（2）基本苗足，有效茎多，延长了生长期，单茎重大；（3）增加了近2个月光温积数，使甘蔗提前早熟，并提高了蔗糖分，（4）有效地避开了甘蔗二点螟的为害；（5）降低生产成本，提高产出比，经济效益十分明显。

甘蔗中膜拱架冬育春移试验研究

小面积甘蔗中膜拱架冬育春移试验于１９９３年１１月在枧头乡进行。试验结果表明：采用甘蔗中膜拱架冬育春移有以下优点：能有效地提高膜内气温、土温和土壤湿度，出苗早；可保证基本苗足，有效茎多，延长了生长期，单茎重且大；增加了近２个月光温积数，提前成熟，糖份量增加；有效地错开了甘蔗二点螟虫危害则；成本低．效益明显。

甘蔗中膜拱架冬育春移试验研究

本试验于１９９３年１１月在本县枧头乡开展小而积甘蔗中膜拱架冬育春移试验研究，主要结果如下：（１）有效提高了膜内气温、土温和土壤湿度，出苗早；（２）基本苗足，有效茎多．延长了生长期．单茎重大；（３）增加了近２个月光温积数．提前早熟，蔗糖份增加；（４）有效地错开了甘蔗二点螟的危害；（５）降低生产成本，提高产出比，经济效益十分明显。

育冬雏鹅技术

育冬雏鹅,就是将春季孵化提前到“立冬”孵化,孵期提前4个月。由于冬季适宜雏鹅生长,冬孵的雏鹅疫病少,生长快,成活高,易饲养,效益好,种鹅利用率高等特点。冬鹅经过几十天的饲养育肥。春节前后就陆续上市,此时的肥仔鹅膘厚肉嫩,肌肉丰满,是春节市场的畅销货。 1.消毒。育雏室在进雏前要用甲醛和高锰酸钾液关闭门窗熏蒸消毒20～30分钟,然后再打开门窗通风换气。育雏室内用具用0.

Breeding of New Winter Wheat Variety Nongda No.399

The winter wheat variety Nongda No. 399 was developed by Agriculture and Biotechnology College of China Agricultural University and Hebei Jincheng Seed Corporation Ltd. with the characteristics of high yield, high-resistance and wide adaptation. The variety is suitable for direct seeding in the winter wheat planting area of the central and southern Hebei Province.

Evolution of 5S rRNA Genes in Ophiopogon xylorrhizus Wang et Dai and O. sylvicola Wang et Tang (Convallariaceae)

To reveal how a large gene family evolved in the highly organized genome, the present study sequenced 294 copies of 5S rRNA genes from six individuals of three populations of Ophiopogon xylorrhizus Wang et Dai, and 45 copies from its closest species, O. sylvicola Wang et Tang. Based on the sequences the gene-phylogeny was inferred through PAUP. The sequences were highly diversified. Of the 339 randomly cloned copies, only 13 pairs (3.8%) were identical, with length varied between 307 - 548 bp (average 438.6 bp). The sequence differentiation index (SDI) in O. xylorrhints was 0.078, in O. sylvicola was 0.032, and between these two species was 0.149. In the most parsimonious tree reconstructed, all of the 294 copies of O. xylorrhizus were grouped into one clade, and those of O. sylvicola were grouped into another clade with 100% bootstrap support. The result demonstrated that the copies of 5S rRNA genes originated from just one progenitor copy, 'founder copy', in both of the species respectively, followed by a series of proliferation, and little, if any, homogenization ever occurred in the copies. As the common ancestor of the two species must have home multiple copies of the genes, all the other copies were lost during or after the speciation. Additionally, the phylogeny clearly showed that the founder copy was proliferated continuously through time, not just once. O. xylorrhizus is an extremely endangered species in which high genetic diversity, selfing and depression on seedlings were observed previously. In our study the sequences from different populations or different individuals were mixed in the branches of the O. xylorrhizus clade, although they evolved independently. It is assumed that gene flow of the species happened much more frequently in the past, making the proliferated copies dispersed to different populations, and the species maintained an amount of genetic diversity. Therefore, the selfing and seedling depression would be the result of a recent event. We suggest that some changes in outer mechanisms, such as the pollinators or seed-dispersers, might cause the species selfed, depressed and, finally, endangered.

SAMHD1通过调控p27表达抑制肝细胞癌细胞增殖的研究

背景与目的:不育α基序结构域和组氨酸/天冬氨酸残基双联体结构域包涵蛋白1(sterile alpha motif and histidine/aspartic acid domain-containing protein 1,SAMHD1)具有抑制多种肿瘤细胞生长的作用,但其调节肝细胞癌(hepatocellular carcinoma,HCC)细胞增殖的作用及机制尚未见报道。探究SAMHD1调控p27的表达对HCC细胞Huh7的增殖、凋亡和细胞周期的影响。方法:首先通过蛋白质印迹法(Western blot)检测正常肝细胞和不同类型HCC细胞中SAMHD1的表达情况。利用基因修饰技术构建过表达SAMHD1、dNTP酶活性位点突变体(SAMHD1-D207N)和磷酸化位点突变体(SAMHD1-T592E)的重组质粒,然后利用四甲基偶氮唑蓝(methyl thiazolyl tetrazolium,MTT)法检测过表达SAMHD1及其突变体或siRNA干扰沉默SAMHD1对HCC细胞增殖的影响,采用流式细胞术检测细胞周期与细胞凋亡情况。在癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据库中分析SAMHD1和p27表达的相关性。结果:HCC细胞中SAMHD1表达上调,过表达SAMHD1、SAMHD1-D207N和SAMHD1-T592E可以抑制Huh7细胞增殖,细胞周期停滞在G1/G0期;相反,干扰SAMHD1后细胞增殖加快,细胞周期停滞在G2/M期。机制研究表明,SAMHD1上调细胞周期蛋白激酶抑制因子p27的表达。在HCC组织中,p27的表达与SAMHD1表达呈正相关。结论:过表达SAMHD1可以上调p27的表达,导致细胞周期停滞在G1/G0期,从而抑制HCC细胞增殖,这种抑制作用不依赖于其dNTP酶活性和磷酸化修饰。

Effects of temperature and salinity on the development of the amphipod crustacean Eogammarus sinensis

The amphipod crustacean Eogammarus sinensis has useful features that make it suitable for use in the aquaculture of fish and large decapod crustaceans.In this study,we investigated the effects of temperature and salinity on the development,fecundity,survival,and growth rate of E.sinensis.The results show that temperature significantly affected E.sinensis development,but salinity.As temperature increased,the duration of E.sinensis embryonic development decreased.Fecundity was affected significantly by temperature and the combination of temperature and salinity,but by salinity alone.In addition,high temperatures accelerated E.sinensis juvenile growth rates,whereas high salinity reduced it.Therefore,our data suggest that E.sinensis tolerates a wide range of salinities and that temperature has more significant effects than salinity on the embryonic development,fecundity,and growth of E.sinensis.Our results shall be useful for mass production of this species for use in aquaculture.

Yielding of Winter Triticale Varieties in Different Protection Levels in Two Sequence Systems

Five-year trials （2011-2015） were accomplished in a continuous field experiment conducted at the Production and Research Station in Balcyny. The experiment was set up on a luvisol medium soil, derived from light loam with the objective of evaluating the response of two winter triticale varieties （Pigmej and Cyrkon） to cultivation without protection （O）, chemical weed control （H） and combined protection against weeds and fungi （HF）. Comparisons were made in two crop sequence systems： cultivation of winter triticale varieties in a 6-field crop rotation and cultivation in a 19-23-year-long monoculture. The results showed that the plant sequence system significantly differentiated the response of winter triticale varieties to the applied levels of field protection. Significantly higher grain yield gains of the winter triticale varieties in response to the application of herbicides or herbicides with fungicides were obtained in the monoculture than in the crop rotation. In the crop rotation, a higher increase in yields induced by the applied plant protection treatments was achieved by the variety Cyrkon. In the monoculture, the response of both varieties to the herbicides applied was nearly identical, while the combined application of herbicides and fungicides raised the yields of var. Pigmej higher than those of var. Cyrkon. Overall for the plant protection levels, var. Cyrkon yielded higher than var. Pigmej by 18.1% more in the crop rotation and by 26.9% in the monoculture. At the same time, var. Cyrkon demonstrated a weaker response to being grown in the monoculture than var. Pigmej did. The average yield of the former was reduced by 21.1%, whereas the latter yielded 26.6% less grain.

A Pre-game Evaluation of the Tourism Legacy of the Beijing 2022 Winter Olympic Games

The role of tourism in social and economic development and stabilizing the Olympic legacy has been widely discussed.Beijing is the first“Dual-Olympic City”.For the first time,the Beijing Winter Olympics has adopted a model of three competition areas,which has attracted much attention to the study of its tourism legacy.In the legacy plan,the construction of the“Beijing-Zhangjiakou Sports Culture and Tourism Belt”was proposed.The development of ice and snow tourism and the cultivation of the ice and snow tourism market is also reflected in many policy documents and government actions.The scientific planning before the competition laid a good foundation for the sustainable development of its ice and snow tourism heritage.This research combines Olympic legacy research with tourism destination theory,and focuses on ice and snow tourism directly related to the Winter Olympics and the significance of pre-event planning for legacy protection.At the same time,the improvement of the quality of ice and snow tourism destinations is embedded in the pre-Olympic legacy,and opinions and suggestions on how to ensure the stability of the legacy after the games are given.This study uses the literature review method and the second-hand materials survey research method,then through establishing a tourism legacy pre-game evaluation model and the use of geographic information,government reports,policies,publicly released statistics and news reports,etc..It explores the legacy of the Beijing 2022 Winter Olympics and Paralympics,aiming to lay the foundation for preserving the continuous value of the ice and snow tourism legacy during and after the Olympics.The results indicate that the Beijing Winter Olympics has made relatively complete plans and reliable progress in both tangible and intangible legacy.Complete tourism infrastructure,an optimistic sport and cultural atmosphere,and the improvement of residents’health concept and sports awareness have become boosters for the development of ice and snow tourism in the Beijing-Zhangjiakou region.