民生视域下的青少年体育贫困问题探讨

青少年体质严重下降是当今社会面临的一项严重问题,青少年体育贫困是造成青少年体质下降的根本原因.把青少年体育贫困问题提升为民生问题,有助于我们增强青少年体质建设问题的紧迫感,有助于加深对青少年体育贫困问题重要性的认识.基于民生的视角,通过对青少年体育贫困现状的审视,认为他者剥夺是造成青少年体育贫困的直接推进剂,自我剥夺使青少年体育贫困进一步加剧.依据青少年体育贫困的原因提出相应的解决对策,以期丰富青少年体育贫困的理论研究,为加快青少年体质建设提供一些理论参考.     

英语语言环境模式的构建

在一些地方缺少真实英语语境的情况下，为英语学习者构建良好的英语学习环境是当今外语教学急需解决的问题。我们的立足点应放在课堂上师生之间、学生之间、电化手段的运用与学生之间的互动作用上，以教师为主导、学生为主体，最大限度地发挥学生的自主创新能力。开辟第二课堂，用丰富多彩的课外活动做补充，构建课上课下、课内课外、多层次、多形式的外语学习环境。     

Embryonic acetylcholine receptors guarantee spontaneous contractions in rat developing muscle

Many proteins are expressed in distinct embryonic and adult forms. However, in most cases we do not know why the embryonic form of proteins is required. This question can be readily addressed for the acetylcholine receptor (AChR) because developmentally specified modifications of this ligand-gated ion channel can be directly related to changes in membrane currents. In developing rat soleus muscle, spontaneous transmitter release causes miniature end-plate currents (m.e.p.cs) to flow into the muscle cell. We show here that these m.e.p.cs in neonatal soleus trigger spontaneous contractions. By injecting m.e.p.cs into young fibres, we showed that only embryonic m.e.p.cs can trigger such contractions; adult m.e.p.cs do not last long enough. Developing muscle fibres must be active for synapse and muscle differentiation. Our experiments indicate that the embryonic form of the AChR is essential for spontaneous contractile activity and may therefore be required for normal neuromuscular development.     

FPGA设计中的时序收敛与时钟切换

FPGA作为最为广泛使用的可编程器件,已经广泛存在于我们的数字电路设计工作中。但是如果对FPGA缺乏深入了解,将严重影响FPGA实际工作的可靠性。本文介绍了FPGA设计中需要着重考虑的两个问题及解决方法。     

利率市场化条件下农村信用社的困难与应对

从分析利率市场化条件下农村信用社面临的问题人手，剖析问题存在的原因，提出：为保证我国农村信用社利率市场化的顺利进行，必须认真总结农村信用社利率试点的经验和教训，在信用社产权改制、金融产品定价、建立利率风险管理机制等方面作一些探索。     

The common biology of cancer and ageing

At first glance, cancer and ageing would seem to be unlikely bedfellows. Yet the origins for this improbable union can actually be traced back to a sequence of tragic--and some say unethical--events that unfolded more than half a century ago. Here we review the series of key observations that has led to a complex but growing convergence between our understanding of the biology of ageing and the mechanisms that underlie cancer.     

Species diversity can drive speciation

A fundamental question in evolutionary ecology and conservation biology is: why do some areas contain greater species diversity than others? Island biogeographic theory has identified the roles of immigration and extinction in relation to area size and proximity to source areas, and the role of speciation is also recognized as an important factor. However, one as yet unexplored possibility is that species diversity itself might help to promote speciation, and indeed the central tenets of island biogeographic theory support such a prediction. Here we use data for plants and arthropods of the volcanic archipelagos of the Canary and Hawaiian Islands to address whether there is a positive relationship between species diversity and rate of diversification. Our index of diversification for each island is the proportion of species that are endemic, and we test our prediction that this increases with increasing species number. We show that even after controlling for several important physical features of islands, diversification is strongly related to species number.     

中国建筑师的社会地位与责任

针对目前存在的我国建筑师社会地位低的说法,分析了其产生的原因,指出建筑师在要求提高社会地位的同时必须首先尽到对业主应尽的责任.     

对媒体娱乐化倾向的反思

当前媒体的娱乐化发展愈演愈烈,我们的媒介似乎患上了＂娱乐综合征＂,娱乐有演变成媒体最主要功能的倾向。这种发展倾向带给大众娱乐的同时,也会给我们的社会和个人带来诸多困惑。     

Recapitulation of premature ageing with iPSCs from Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is a rare and fatal human premature ageing disease, characterized by premature arteriosclerosis and degeneration of vascular smooth muscle cells (SMCs). HGPS is caused by a single point mutation in the lamin A (LMNA) gene, resulting in the generation of progerin, a truncated splicing mutant of lamin A. Accumulation of progerin leads to various ageing-associated nuclear defects including disorganization of nuclear lamina and loss of heterochromatin. Here we report the generation of induced pluripotent stem cells (iPSCs) from fibroblasts obtained from patients with HGPS. HGPS-iPSCs show absence of progerin, and more importantly, lack the nuclear envelope and epigenetic alterations normally associated with premature ageing. Upon differentiation of HGPS-iPSCs, progerin and its ageing-associated phenotypic consequences are restored. Specifically, directed differentiation of HGPS-iPSCs to SMCs leads to the appearance of premature senescence phenotypes associated with vascular ageing. Additionally, our studies identify DNA-dependent protein kinase catalytic subunit (DNAPKcs, also known as PRKDC) as a downstream target of progerin. The absence of nuclear DNAPK holoenzyme correlates with premature as well as physiological ageing. Because progerin also accumulates during physiological ageing, our results provide an in vitro iPSC-based model to study the pathogenesis of human premature and physiological vascular ageing.     

论绿色植物在环境保护中的作用

本文对绿色植物的富集作用，分解转化毒物以及吸附灰尘等作用进行了详细阐述，介绍了绿色植物（尤其是森林）在环保中占有十分重要的地位。     

“抑武”“扬武”与传统武术的传承和发展

运用文献资料法和逻辑推理法等研究方法对我国历史上的"抑武"和"扬武"现象进行了探索,并与传统武术的传承和发展紧密地联系在一起, 对当前传统武术发展低靡的原因进行了剖析,指出传统武术只有在政府的大力倡导和推广下,通过大力挖掘传统武术的技击精华;精选教学内容;培养学生们的学习兴趣;积极举办各种赛事;提高获胜者的社会地位等办法,使学习传统武术成为一种时尚,传统武术才能走出低谷,从而达到通过继承和发展传统武术等优秀文化遗产、发扬民族精神、增强民族凝聚力的目的.     

我国政府投资项目招标投标活动监督机制的改革

招标是政府投资项目控制成本的重要手段，但由于政府投资项目的业主没有产权约束，因此政府必须对招投标活动加强监督，否则将会产生大量的违规行为。分析了我国政府投资项目招投标活动监督现状，指出应该构建内外有机结合的监督机制，并就此提出了几点具体的建议。     

Mutation and sex in a competitive world

How do deleterious mutations interact to affect fitness? The answer to this question has substantial implications for a variety of important problems in population biology, including the evolution of sex, the rate of adaptation and the conservation of small populations. Here we analyse a mathematical model of competition for food in which deleterious mutations affect competitive ability. We show that, if individuals usually compete in small groups, then competition can easily lead to a type of genetic interaction known as synergistic epistasis. This means that a deleterious mutation is most damaging in a genome that already has many other deleterious mutations. We also show that competition in small groups can produce a large advantage for sexual populations, both in mean fitness and in ability to resist invasion by asexual lineages. One implication of our findings is that experimental efforts to demonstrate synergistic epistasis may not succeed unless the experiments are redesigned to make them much more naturalistic.     

中国传统文化的“后发优势”

谈论中国的文化传统,常常使人陷入一个悖论环境。但是若对这个问题加以变焦处理,可以看出不同侧面：从虚实分,西方文化其用在“实”,中国文化其用在“虚”;在某个历史阶段,西方文化其优在“先”,中国文化其优在“后”;从“段位”看,西方文化段位在“中端”,中国文化段位在“高低两端”。在中国国力日渐强大的今天,物质进步与我们的精神气质显得有些不相称,这是我们追讨传统的一个最重要的理由。     

环境考古学刍议

人类文化和自然界相互依存,决定了只有结合古环境来研究古文化,才能认识古文化,才能认识人类迁徙的真正原因。环境考古学主要研究古文化及其与自然环境、社会环境间的关系。我国历史和自然环境条件优越,只要我们抓住考古学和环境科学向新阶段迈进的契机,我国环境考古学必将迅速发展,并一定会在认识古人类历史、行为和生活方式方面发挥更重要的作用。     

Neuronal basis of age-related working memory decline

Many of the cognitive deficits of normal ageing (forgetfulness, distractibility, inflexibility and impaired executive functions) involve prefrontal cortex (PFC) dysfunction. The PFC guides behaviour and thought using working memory, which are essential functions in the information age. Many PFC neurons hold information in working memory through excitatory networks that can maintain persistent neuronal firing in the absence of external stimulation. This fragile process is highly dependent on the neurochemical environment. For example, elevated cyclic-AMP signalling reduces persistent firing by opening HCN and KCNQ potassium channels. It is not known if molecular changes associated with normal ageing alter the physiological properties of PFC neurons during working memory, as there have been no in vivo recordings, to our knowledge, from PFC neurons of aged monkeys. Here we characterize the first recordings of this kind, revealing a marked loss of PFC persistent firing with advancing age that can be rescued by restoring an optimal neurochemical environment. Recordings showed an age-related decline in the firing rate of DELAY neurons, whereas the firing of CUE neurons remained unchanged with age. The memory-related firing of aged DELAY neurons was partially restored to more youthful levels by inhibiting cAMP signalling, or by blocking HCN or KCNQ channels. These findings reveal the cellular basis of age-related cognitive decline in dorsolateral PFC, and demonstrate that physiological integrity can be rescued by addressing the molecular needs of PFC circuits.     

论刺激需求与创造有效供给

经济主体是需求与供给的统一 ,不能离开供给谈需求。目前国内有效需求不足制约经济增长的根源在于无效供给过剩 ,有效供给不足。解决这个问题的根本出路是调整产业结构 ,促进技术和制度创新 ,以启动和创造有效供给 ,同时完善市场机制 ,创造良好的市场环境     

马克思主义哲学深层转型的基本思路

改革开放引起了我国社会的转型,即从计划经济向市场经济的转型。在意识形态领域里作为我国根本指导思想的马克思主义哲学随着改革开放的深入也应相应地转型,即从批判性、革命性到建设性、建构性的转型。要实现这一深层转型要做到"三个必须":必须凸显马克思主义理论的隐性话语体系即建设性与建构性、必须立足于当代社会主义实践、必须实现马克思主义哲学与当代西方哲学的相互批判与对话。     

试论非体院大学运动队的基础

分析指出,非体育院校大学要办好运动队,必须在政策允许的前提下,做好选材的基础工作;必须结合区域体育运动的发展特长,以使运动队具备吸收新鲜血液的源泉;必须在校内形成代表队运动项目的大众爱好氛围,以保证运动队发展壮大的群众基础.