A Step toward Molecular Evolution of RNA: Ribose Binds to Prebiotic Fatty Acid Membranes,and Nucleosides Bind Better than Individual Bases Do

A major challenge in understanding how biological cells arose on the early Earth is explaining how RNA and membranes originally colocalized. We propose that the building blocks of RNA (nucleobases and ribose) bound to self-assembled prebiotic membranes. We have previously demonstrated that the bases bind to membranes composed of a prebiotic fatty acid, but evidence for the binding of sugars has remained a technical challenge. Here, we used pulsed-field gradient NMR spectroscopy to demonstrate that ribose and other sugars bind to membranes of decanoic acid. Moreover, the binding of some bases is strongly enhanced when they are linked to ribose to form a nucleoside or – with the addition of phosphate – a nucleotide. This enhanced binding could have played a role in the molecular evolution leading to the production of RNA.     

2020年国内外宏观经济形势分析及预判

2020年,预计全球贸易进展局势出现缓和,世界经济增长小幅回升至2.6%左右,主要经济体面临的贸易政策、货币政策和地缘政治局势等不确定性因素仍较多,世界经济增长面临的下行风险仍较大。2019年中国经济总体平稳,GDP增长6.1%。2020年我国经济将继续保持增长稳健、结构优化、动能转换的发展态势,预计将实现6.0%的增长。     

Social licence: power imbalances and levels of consciousness – two case studies

ABSTRACT

Social licence to operate (SLO) is a term that is finding increasing acceptance in a number of industries. Like all new terms, its precise meaning and implications are still being investigated. Using data from previous studies, this paper offers an analysis of the SLO of two case studies with each study being viewed separately through the grid of a distinct theoretical framework. Case study 1 looks at the development of differential social licence negotiated in the Hamlet of Cambridge Bay, Nunavut, as a result of an impact and benefit agreement negotiated between Tahera Diamond Corp. and the Kitikmeot Inuit Organisation in 2004. The study demonstrates that general acceptance of resource development can be uneven and reflect an unequal distribution of decision-making power. In case study 2, stakeholders of a failed mineral development project were queried across time about the specifics of the proposed mine development and were queried about resource development across different levels of consciousness. Perhaps, SLO is variable across different levels of consciousness. The paper concludes with observations about the variable nature of SLO acceptance across populations and across levels of consciousness within individuals. Perhaps, the concept of SLO is, in fact, complex, difficult to define and measure and, at this point, of limited utility as a measure of resource development acceptance.     

Self‐similarity analysis of vehicle driver's electrodermal activity

This paper characterizes stress levels via a self‐similarity analysis of the electrodermal activity (EDA) collected in a real‐world driving context. To characterize the EDA richness over scales, the fractional Brownian motion (FBM) process and its corresponding exponent H, estimated via a wavelet‐based approach, are used. Specifically, an automatic scale range selection is proposed in order to detect the linearity in a log scale diagram. The procedure is applied to the EDA signals, from the open database drivedb, originally captured on the foot and the hand of the drivers during a real‐world driving experiment, designed to evoke different levels of arousal and stress. The estimated Hurst exponent H offers a distinction in stress levels when driving in highway versus city, with a reference to restful state of minimal stress level. Specifically, the estimated H values tend to decrease when the driving environmental complexity increases. In addition, the estimated H values on the foot EDA signals allow a better characterization of the driving task than that of hand EDA. The self‐similarity analysis was applied to various physiological signals in literature but not to the EDA so far, a signal which was found to correlate most with human affect. The proposed analysis could be useful in real‐time monitoring of stress levels in urban driving spaces, among other applications.     

澳门融入粤港澳大湾区世界机场群路向研究

粤港澳大湾区世界城市群与世界机场群相伴而生、联动发展.建设世界级机场群，需要5大机场错位发展和良性互动.澳门国际机场是澳门融入粤港澳大湾区重要一极，但机场发展存在与澳门定位、香港珠海空域空运矛盾、澳门土地和环境现状等相关的问题.因此，澳门国际机场今后发展需在葡语国家航线、珠澳密切合作、公务机产业方面努力实现跨越式发展.然而，澳门国际机场改扩建问题争议不断，本文就原址扩建、填海区新建、飞地黄茅岛新建3种模式进行比较分析，探索符合澳门长远利益之方案.     

TBS分选机在王家岭选煤厂的应用

阐述了TBS分选机的工作原理和技术参数。分析了两种TBS分选机入料及产物的粒度和密度组成,对比了两种TBS分选机的分选精度。结果表明:两种TBS分选机的入料粒度组成类似,0.2~1.0 mm质量分数大于60%,属主导粒级,适合采用TBS分选机分选,其精煤灰分均小于10%,尾煤灰分均高于57%,分选效果较好。当精煤灰分为9.50%时,两种TBS分选机的入料煤样均属易选煤。两种TBS分选机的Ep值分别为0.178和0.183,I值分别为0.239和0.246,分选效果基本相同,均达到较高水平,分选下限达到0.2 mm。     

高层小康住宅设计及住宅发展预测

根据我国经济发展趋势 ,城市人口爆炸 ,造成住宅紧缺这一实际情况 ,提出了高层小康住宅的设计构想 ,充分体现我国 2 1世纪初叶的居住水平。     

ORDER视角下的西方建筑设计

"ORDER"一般常解释为柱式,并称其为西方古典建筑的标志。自工业革命以来,柱式似乎渐已退出历史舞台,代之以放映工业时代精神的新建筑艺术形式。然而,ORDER不仅指柱式,她还蕴含了秩序、等级、层次、序列、法则、关系等诸多意义,并直指现代建筑之精髓。试从对ORDER的解读入手,阐明西方建筑发展的内在关联性,以及古典与现代建筑间的精神传承。     

小中见大-谈南京市29中教学综合楼建筑设计

通过对南京市29中教学综合楼工程的介绍,分析在尺地寸金的地块中,合理布置功能复杂建筑,巧妙结合异形地块优化设计,充分利用秦淮河风光带,重视整体环境的和谐;塑造具有独特性、省地性、文化性的校园建筑.