Identification of psychoactive alkaloids in ancient Andean human hair by gas chromatography/mass spectrometry

Various ethnographic sources have demonstrated the symbolic and ritualistic importance of psychoactive plants in Native American societies. The social milieu of these mind- altering plants appears to be ancient. Archaeological evidence during the Tiwanaku empire expansion along the Atacama Desert of Chile, circa 500–1000 A.D., shows the presence of highly decorated snuffing tablets and tubes as grave goods. The preservation of mummified human bodies in the Azapa Valley, northern Chile, provided an opportunity to test the exact nature of the psychoactive plants used in this region. Using gas chromatography/mass spectrometry (GC–MS), here we show that ancient Andean populations from northern Chile consumed Banisteriopsis, a vine that contains harmine. This is the first direct archaeological evidence of hallucinogenic and medicinal ethnographic practices. Interestingly enough, this rainforest plant does not grow along the Atacama coast, thus our findings suggest extensive plant trade networks in antiquity as far as the Amazon.     

基于国际酒店集团布局的中国城市网络连接度研究

截至2013年5月,世界酒店业300强中在中国形成网络化经营的20家国际酒店集团已在我国221个城市有布局。不同于以泰勒为代表的基于跨国生产性服务企业布局的城市连接度研究,本文以消费性服务企业中的国际酒店业在华布局为研究切入点,通过城市网络连接度测度发现:第一,我国酒店业城市网络已形成以上海、北京、杭州、西安为中心的层级体系,上海已具备成为国际酒店业首位城市和世界级旅居城市的条件;第二,在环渤海、长三角和珠三角三大经济区域中,基于国际酒店集团服务价值判定的区内和区际城市连接度水平存在较大差异,其中长三角地区连接度总和与均值最高;第三,在酒店业的全球生产网络中,中国城市的酒店业布局具有品牌层次的低端锁定特征,中心性和总部经济效应有待提高。     

Microeconomic Formulation and Estimation of a Residential Location Choice Model: Implications for the Value of Time

Abstract We formulate a microeconomic model of residential location choice behavior as an aggregate of the individual behaviors of household members, subject to individual time constraints and a common income budget. A simplified version of the model is estimated from stated preference rank‐order data, yielding a function that may be interpretated as a conditional indirect utility function. We consider Box‐Tukey transformations, segmentation by income class, and a consistent treatment of data at different rank depths using the simultaneous mixed‐estimation method. Measures of the household's willingness‐to‐pay (through rents) for reducing travel times to work and study in the short run, are interpreted as subjective values of time and compared with such values derived from mode choice models. Our results are plausible, and consistent with recent findings showing that the short‐run benefits of transport projects derived by transport models are larger than benefits measured at the land use system.     

陕西韩城普照寺彩绘泥塑制作材料与工艺研究

普照寺位于陕西省韩城市,寺内现存有五尊精美绝伦的元代彩绘泥塑。为了解普照寺彩绘泥塑制作材料与工艺,采用光学显微镜、X射线衍射仪、显微红外光谱仪、显微拉曼光谱仪、扫描电镜-能谱仪和X光照相等技术手段进行科学分析。结果表明,普照寺彩绘泥塑内部结构为十字型交叉木骨架,粗泥层和细泥层塑土矿物成分基本一致,具有强度高、抗风化能力强和可塑性好的特点;粗泥加筋材料为麦秸秆和麦粒壳,细泥加筋材料为棉和麻;颜料层显色成分除蓝色外均为古代壁画常见的矿物颜料,存在重层重彩情况。研究结果将为普照寺彩绘泥塑的后续保护修复提供科学依据,并为陕西地区元代彩绘泥塑传统工艺的研究补充科学信息。     

东牌楼汉简《素上言盗取文书案卷》的缀合与考释

作者对新近公布的《长沙东牌楼东汉简牍》作了缀合与考释,尝试新释和重新标点、断句,加深了我们对秦汉盗取文书案件的认识。     

人工神经网络：一种新的旅游市场需求预测系统

本探究了人工神经网络(ANN)作为一种新型的预测系统在旅游市场需求研究中的重要性,并指出：在对旅游需求进行预测时,人工神经网络较之多元回归分析方法适用范围更广,显性更强。     

中国省域旅游业竞争力综合定量评价

旅游业竞争力是包括现实竞争力、潜在竞争力、支持竞争力在内的综合概念。本文在总结前人研究成果的基础上,结合省域旅游业发展实际,构建出省域旅游业竞争力综合评价指标体系,运用层次分析法计算出省域旅游业竞争力分值,进而结合聚类分析,探讨了我国省域旅游业竞争力的类型,客观分析了各省、市、区旅游业竞争优势与劣势,并就提升省域旅游业竞争力进行了思考。     

COVID-19 and employment relief programs: A tale of spatially blind policies for a spatially driven pandemic

We use the case of Chile to analyze the effectiveness of a spatially blind employment relief program (hereafter referred to as the LPE program) established by the Chilean government and implemented during the COVID-19 pandemic. Chile is an interesting case because on the one hand its nonpharmaceutical interventions were spatially driven by health indicators based on small geographical areas; hence, producing sizeable regional and temporal variation of the local conditions induced by the COVID-19 pandemic. On the other hand, the LPE program was designed and implemented nationally without distinction of local labor market or pandemic conditions, and each firm could decide whether to enroll in the program. By exploiting the spatial-temporal variation of exogenously imposed lockdowns and using a difference-in-differences panel data framework, we find that the LPE program was only effective for a group of regions in the country but, more importantly, that the LPE program was less effective during lockdowns. Moreover, the requirements of the LPE program were vague and did not target specific populations or entities. Consequently, our results suggest that women, informal and small firm workers, and most economic sectors throughout the country were less able to take advantage of the benefits of this program.