Radiocarbon reservoir effects in human bone collagen from northern Iceland

Human bone collagen from a series of Icelandic human pagan graves was radiocarbon (¹⁴C) dated to aid understanding of early settlement (landnám) chronologies in northern Iceland. These individuals potentially consumed marine protein. The ¹⁴C age of samples containing marine carbon requires a correction for the marine ¹⁴C reservoir effect. The proportion of non-terrestrial sample carbon was quantified via measurement of carbon stable isotopes (δ¹³C) using a simple mixing model, based on δ¹³C measurements of archaeofaunal samples. Non-terrestrial carbon was also quantified in six pig bones from the archaeofaunal dataset. Assuming all non-terrestrial carbon in human and pig bone collagen was marine-derived, calibrated age ranges calculated using a mixed IntCal09/Marine09 calibration curve were consistent with an early settlement date close to landnám, but several samples returned pre-landnám age ranges. Measurements of nitrogen stable isotopes (δ¹⁵N) strongly suggest that many of the human bone collagen samples contain freshwater diet-derived carbon. Icelandic freshwater systems frequently display large freshwater ¹⁴C reservoir effects, of the order of 10,000 ¹⁴C years, and we suggest that the presence of freshwater carbon is responsible for the anomalously early ages within our dataset. In pig samples, the majority of non-terrestrial carbon is freshwater in origin, but in human samples the proportion of freshwater carbon is within the error of the marine component (±10%). This presents a major obstacle to assessing temporal patterns in the ages of human remains from sampled graves, although the majority of grave ages are within the same, broad, calibrated range.     

Variability in the marine radiocarbon reservoir effect in Muscat (Sultanate of Oman) during the 4th millennium BC: reflection of taphonomy or environment?

Radiocarbon (¹⁴C) dating of archaeological coastal sites in arid areas is challenging because of the relative rarity of datable terrestrial artefacts. Marine artefacts provide an abundant source of carbon, which is technically easy to date but radiocarbon dates need to be corrected for local variations from the global average marine ¹⁴C reservoir age (ΔR). In archaeological sites, this is usually done by the comparison of the ¹⁴C age measured between coeval pairs of terrestrial and marine samples that have no inbuilt age. Here, we present the results of a study that aims to determine the local ¹⁴C marine reservoir effect (MRE) along the Eastern coast of the Arabic Peninsula during the 4th millennium BC, a period of important cultural, demographic and social changes in this region. Previous estimates of the MRE based on associated shells and charcoal vary by about 400 ¹⁴C yr and this is a serious limitation to the establishment of a precise chronology in the area based on marine material. In order to maximize the chances to obtain contemporaneous terrestrial–marine pairs for a new assessment of the MRE in this region we dated charcoal, shells, fish and turtle bones as well as human bones found in three recently and carefully excavated graves from Ra’s al-Hamra RH5. A large variability was found between charcoals (up to 240 ¹⁴C yr) and marine specimens (up to 785 ¹⁴C yr) present in the same grave. This variability was attributed to inbuilt ages, diagenesis and possibly environmental factors although taphonomic processes cannot be excluded. We discarded the oldest charcoals and used the ¹⁴C ages obtained on human apatite as a cut-off value to remove the marine outliers. Two out of the three graves provided terrestrial and marine assemblages which did not differ statistically and were used to calculate an average MRE of 645 ± 40 ¹⁴C yr (ΔR = 255 ± 55 ¹⁴C yr). This value is consistent with previous estimates based on the ¹⁴C dating of marine sediments off Pakistan and suggests stability of the MRE in the Arabian Sea since the 4^th millennium BC.     

Household Incomes in Central Asia: The Case of Post-Soviet Kazakhstan

Two European geographers present the findings of a sizeable survey (n = 7,515) providing a detailed geographical analysis of household incomes and reliance on personal subsidiary garden plots across Kazakhstan. The authors focus on assessing the extent to which Kazakhstan's rising GDP during the post-Soviet period has coincided with an increase in the general population's personal income and ability to secure adequate food supplies for personal consumption. The fine geographical scale of analysis of the survey data (significantly less coarse than oblast-level data) enabled them to identify regions characterized by "trickle-down" income, largely centered on the country's two main urban centers and areas of resource exploitation. The patterns revealed in the paper have relevance to the debate concerning the uneven distribution of benefits from resource exploitation (notably oil and gas) to Kazakhstan's population. Journal of Economic Literature, Classification Numbers: D100, D310, I300, Q120, R290. 2 figures, 6 tables, 51 references.     

SEISMIC DESIGN REGULATION CODES: CONTRIBUTION OF K-NET DATA TO SITE EFFECT EVALUATION

The purpose of this study is to compare the site effect section of building codes (EC8 and UBC97) with the set of data provided by the Kyoshin network. In order to obtain a set of site coefficients and spectral shapes, we have first deduced an attenuation law for both horizontal and vertical motion. Site conditions are represented by the shear velocity averaged over the upper 30 m (V _s ³⁰). Our site classification (4 categories similar to those proposed in the new ECS and the UBC97) is based on borehole investigations at every station. This classification has permitted to distinguish clearly four response spectra which demonstrates the efficiency of V _s ³⁰ as characterising site conditions. Our law is then used to test site coefficients and spectral shapes of building codes ECS and UBC97. Concerning spectral shapes and site coefficients, our results are found to be in good agreement with EC8 and UBC97 only if category B (400<V _s ³⁰<800 m/s) is taken as reference. We also conclude that a site which is characterised as “rock” on geological criteria can not generally be classified in category A (V _s ³⁰>800 m/s). This suggests that classification in category A should be based only on field measurements. Concerning vertical motion, our analysis of the K-NET data shows that the ratio av/ah (vertical peak ground acceleration over horizontal peak ground acceleration) is between 0.50 and 0.68.     

Household economic resilience to catastrophic rainstorms and flooding in a Chinese megacity

Megacities situated on flood plains face escalating risks of waterlogging and inundation. Tianjin is one of these megacities in China where residents are exposed to these risks and not well prepared for their consequences. Government policies should support the most vulnerable and less resilient groups. This study can inform policy‐making by identifying the socio‐economic characteristics of those who are financially better prepared for the consequences of catastrophic rainstorms and flooding. A structured questionnaire survey was administered to 332 Tianjin residents. Results confirm that financial conditions crucially determine household resilience to these natural hazards. Lower‐income and less educated urban residents have lower resilient capacity. Weak engagement in the community, including residential committees and other organisations, is related to lower capacity to cope with the economic consequences of extreme weather events. Less resilient groups are therefore those who are subject to urban poverty and have limited social capital. Tianjin and other cities in the developing world require resilience strategies that attend to this segment of urban population.     

高速铁路的社会经济影响与空间效应的研究进展——基于国际SCI和SSCI期刊论文的分析

高速铁路正在重塑区域空间格局,并对社会经济发展产生深刻影响。本文以检索获得的347篇高速铁路社会经济影响与空间效应研究相关的国际SCI和SSCI期刊论文为研究对象,从文献来源、发文量年际变化、作者和机构、载文期刊、研究主题等方面对全球高速铁路社会经济效益研究的趋势和特征进行了系统分析;并从高速铁路的空间效益、经济影响以及社会影响等三个方面对研究内容和主题开展了系统综述;最后从研究趋势和研究内容等方面归纳了主要结论,提出未来研究的趋势与方向。结果表明,在高速铁路快速发展推动下,全球高速铁路效应研究呈现快速增长的态势,并在高速铁路的空间效应、社会经济效应等方面取得了较为丰硕的成果。中国大陆学者在高速铁路效应研究上异军突起,成为近年来国际发表论文最多的国家,但在研究深度和广度以及研究成果影响力上与西班牙等欧美国家仍有较大的差距。     

元明清北京的能源供应及其生态效应

元明清三朝定都北京以后,城市能源中的木柴、木炭主要来源于周边地区的森林。林木的过度砍伐,对太行山北段、燕山南麓山区造成了显著的生态破坏,在明清时期表现得尤为突出。煤炭在能源构成中的地位越来越重要,但采煤对西山一带的地表形态、植被覆盖、河流水源等所造成的危害也不容忽视。文献和碑刻资料,证实了北京能源供应的发展过程及其连带的生态效应。     

日本的节能措施、成效与启示

以能源资源在全社会的最优配置和能源利用效率的提高为主要目标,日本实施了以节能技术创新为核心的“规范-服务-鼓励”三位一体的节能措施体系,成效显著。日本节能的做法,对当前我国做好节能减排工作很有借鉴意义。     

2008年奥运旅游效应与中国奥运旅游圈构想

举办奥运会最大的经济受益点是旅游业,中国旅游业应充分抓住奥运给旅游业带来的各种效应,充分利用良好的区位条件,合理确定和设计旅游区位,确立"一个核心、多中转辐射地、五圈共享"的"中国奥运旅游圈"区位开发模式,构建北部历史古迹都市文化核心旅游圈、东部东方文化现代都市旅游圈、南部经济特区热带风情都市旅游圈、中西南奇山丽水民族风情旅游圈、西部神奇景观旅游圈,实施整体形象设计与促销战略、多等级多系列产品战略、网络化大交通战略、信息化战略、区域协作战略、规模化战略、可持续发展战略,把握机遇,发挥奥运旅游的最大效应。     

增强高校思想政治教育实效性的对策探析

思想政治教育是目标十分明确的实践活动。思想政治教育的实效性是其生命力的根本所在,而其实效性的关键在于做到知与行的统一。本文对高校思想政治教育知行不一、知行脱节的具体表现进行了分析,并提出了通过强化知行统一而提高思想政治教育实效性的具体对策。