不同培养液对牛孤雌生殖胚胎和体细胞核移植胚胎体外发育的影响

采用体外成熟的牛卵母细胞 ,经 5 μmol/LIonomycin 5min和 2mmol/L 6 DMAP 5 μg/mLCCB 4h激活 ,分别在TALP M 199(TM ,1∶2 )、BMOC M 199(BM ,1∶2 )和CR1aa培养液内培养 ,2 4h和 3 6h各组卵母细胞的卵裂率分别为5 6.4%、5 5 .6%、5 3 .6%和 72 .0 %、75 .9%、79.0 % ,无显著差异 (P >0 .0 5 ) ;培养 8d后囊胚发育率分别为 18.2 %、2 1.4%和 2 9.3 % ,CR1aa内培养孤雌生殖胚的囊胚发育率显著高于TM (P <0 .0 1)。皮肤成纤维细胞构建的重组胚经同法激活后 ,分别在TM、BM和CR1aa内培养 ,2 4h和 3 6hBM和CR1aa内重组胚的卵裂率显著高于TM (4 9.7%、49.8%比 2 0 .5 % ;74.1%、73 .2 %比 5 0 .0 % ) (P <0 .0 1) ;虽然培养 8d后各组胚胎的囊胚发育率无显著差异 ,但CR1aa内重组胚的囊胚发育率稍高 (12 .3 %比 9.8%、11.5 % )。结果表明 ,CR1aa更适合孤雌生殖和体细胞核移植胚胎的体外培养。     

FSH对仔猪睾丸支持细胞增殖和GDNF表达的调节

以原代培养的仔猪睾丸支持细胞(SC)为试验模型,研究了FSH对SC胶质细胞源性神经营养因子(GDNF)表达及其增殖的影响。结果显示,外源性添加FSH可促进GDNF蛋白表达,而且这种促进作用具有浓度和时间依赖关系,GDNF蛋白水平随着FSH浓度的增加而升高,当FSH浓度为50 ng/mL时,GDNF水平达到最高,然后逐渐降低;FSH(50 ng/mL)作用30 min,可显著促进GDNF蛋白的表达(P<0.05),当FSH作用1 h时,GDNF蛋白水平达到最高,随后逐渐降低。FSH可以时间-剂量依赖性促进SC增殖细胞核抗原(PCNA)的表达,FSH(50 ng/mL)作用30 min时,PCNA的表达显著增加(P<0.05),作用1 h达极显著水平(P<0.01),至2 h时,PCNA蛋白的表达水平达到最高,随后逐渐降低。提示,FSH可在体外条件下通过刺激SC表达GDNF进而促进其增殖。     

POLICIES OF LAST RESORT FOR DEALING WITH NORTH KOREA’S NUCLEAR WEAPONS PROGRAMME

This paper analyzes the policy remedies for dealing with North Korea's nuclear weapons and missile programs. After six nuclear tests and three recent successful ICBM tests, North Korea is close to miniaturizing nuclear warheads and establishing a reliable delivery system, thus achieving a much-feared nuclear weapons capability. In defiance of the extraordinarily tough U.N. Security Council resolutions, Pyongyang persists in developing nuclear weapons. North Korea's nuclear weapons program already has exceeded the strategic patience, of the U.S.-ROK alliance. Harsher policy options to deal with the DPRK nuclear weapons are imperative. Several drastic options, including severe sanctions, preventive bombing, nuclear armament of South Korea, are evaluated in the final round of engagement policy on guaranteeing nonaggression and a peace agreement with Pyongyang.     

Unexpected Persistence Amidst Enlargement Stasis: Usages of Europe in Turkey’s Nuclear Energy Debate

Recent studies on European Union (EU) Enlargement have emphasised the importance of usages of ‘Europe’ by domestic actors as a necessary condition for the EU to have an impact on domestic politics. We study the usages of Europe in the critical case of Turkey’s nuclear energy policy. We analyse the narratives and actions of domestic actors in Turkey to identify if they use ‘Europe’ (the EU and the idea of Europe). We reach the counter-intuitive finding of usages by both state and non-state actors, which illustrates that usages of Europe can persist despite enlargement stasis in candidate states.     

论苏联解体后的“核遗产”及核扩散危机

苏联解体后其庞大的核武库也一分为四,在核武器系统、核材料、核科学家及核技术等三个层次都出现了失控的核扩散危机。以美国为首的国际社会从各个方面给予了大力援助,使前苏联庞大的"核遗产"得到了妥善的处理。因苏联解体而一度出现的核国家增多的问题得以解决,核扩散危机也基本得到消除。这不仅有效地捍卫了国际核不扩散体制,而且在实践上也是对国际核不扩散机制的补充和发展,对人类社会的和平与安全也是重大的贡献。当朝鲜和伊朗核问题屡成危机而长期困扰国际社会时,我们重温这段历史,也具有深刻的现实意义。     

中国在朝鲜半岛的地缘安全战略分析

朝鲜半岛地处东北亚核心地带,是我国重要的战略侧翼。作为与中国山水相连、唇齿相依的邻邦,朝鲜半岛在中国的地缘安全战略中一直具有极其重要的意义。冷战结束以来,朝鲜半岛的地缘政治环境发生了重大变化,原来由美苏主导的两极格局趋向多极化,在某种程度上形成了大国相互竞争的局面,处于较弱地位的朝韩两国也不由自主地被纳入了周边大国的战略轨道,半岛形势空前复杂化。而两次朝核危机的爆发更使朝鲜半岛局势的发展跌宕起伏,波折不断。面对错综复杂的半岛形势,中国从"维护朝鲜半岛的和平与稳定"这一战略目标出发,确立了以"对话和合作"为基本特征的安全战略,并积极推动朝核问题的和平解决,为缓和半岛紧张局势,维护东北亚地区和平与稳定发挥了不可替代的作用。     

构建中美核战略稳定性框架:非对称性战略平衡的视角

权力转移导致中美战略竞争加剧,维护中美战略稳定成为攸关中美关系发展以及世界和平与稳定的重大问题。构建中美核战略稳定性框架是实现中美战略稳定的基石。传统战略稳定理论主要基于美苏两大对称性阵营的敌对关系,对于不对称性和动态权力转移背景下的中美核战略稳定性的理论解释力和实践指导性不足。基于非对称战略平衡视角,中美核战略稳定性框架应以保证中国第二次核打击能力为基础。在机制层面,中美要加强交流、协商和谈判以建立相关机制,逐渐形成中美核战略关系的共识,推动达成稳定中美核战略关系的协议、条约等法律性承诺,从而构建稳定中美核战略关系的政治框架。在结构层面,中国无需谋求与美国对等的核力量。统筹考虑军事效用和政治效果,构筑包括核实力、核威慑决心和核威慑信息传递的完备核威慑战略,确保处于弱势的中国拥有对美国进行核反击造成美不可承受损失的能力,是实现中美核战略稳定的关键。     

Critical Misunderstandings: Ineffective International Governance and the UK Nuclear Industry

In 2017, significant media and political interest was sparked by the UK decision to leave Euratom, the European Atomic Energy Community. While such interest in nuclear matters has to be welcomed, the apparent lack of knowledge displayed in the regulatory governance of the UK nuclear industry is disquieting. This article therefore offers an overview of the publicly funded UK nuclear industry and its regulatory governance including its links with European and global nuclear agencies to inform the debate and to identify critical issues in need of resolution.     

Germany’s Renewable Energy Shift: Addressing Climate Change

This essay considers how the state can be used successfully to initiate and support an energy shift from nuclear energy to renewable energy, as demonstrated by Germany’s Renewable Energy Act from 2000 and its previous Electricity Feed-in-Law (1991). As a result of these nationwide policies, Germany has reduced levels of greenhouse gas emissions, has a higher level of both energy security and employment in the renewable energy industry than the US. Germany is a global leader in this industry and provides a model for other nations in this regard.     

Arguing deep ideational change

ABSTRACT

How do actors come to contest previously uncontested background ideas? This is a difficult question to ask. On the one hand, deep backgrounds seem to be too foundational for actors to transform. Their political efficacy appears to end where ideas constitute their efficacy in the first place. On the other hand, ideas must not be reified. Even deeply taken-for-granted ideas do not always stay the same, and agents have a lot to do with these changes. In order to answer this question, we draw from social theory and rhetorical studies. We conceptualize the deep background as nomos, and the more easily accessible background as endoxa. We then proceed to identify three sets of conditions that make nomic change possible. These relate to opportunity, message, and messenger. Nomic change becomes possible when the need for something new has become widely established and a supply of new nomic ideas is easily available (opportunity); new nomic ideas are ‘smuggled’ into more orthodox and widely resonating arguments (message) as well as rhetorical encounters in which these arguments are made; and advocates are widely recognized as interlocutors (messenger). A plausibility probe of nomic contestation about nuclear governance provides evidence for this framework.