Microscopic age determination of human skeletons including an unknown but calculable variable

Histomorphometric semi-automatic image analysis of cross-sections of 101 femoral diaphyseal bone sections were performed to reconsider to what degree osteon remodelling in the outer cortex is affected by age. The data were analysed statistically using the generalized least squares method. The model estimation, which includes the covariance matrix of four single equation residuals, improves the accuracy of age determination. The standard deviation, however, of age prediction remains 12.58 years. An experimental split of the data was made in order to demonstrate that the use of subgroups gives a false impression of higher precision of age determination. The present study demonstrates that determination of age at death through microscopic bone morphometry is considerably less precise than generally stated in the literature.     

Hydrothermal fluid flow models of stratiform ore genesis in the McArthur Basin, Northern Territory, Australia

This paper explores the role of basin‐scale fluid migration in stratiform Pb–Zn ore formation in the southern McArthur Basin, Australia. Mathematical models are presented for coupled brine migration and heat transport in the basin. The models account for: (i) topographically driven flow (forced convection) during periods when parts of the McArthur Basin were subaerial and elevated above the central Batten Fault Zone; (ii) density‐driven flow (free convection) during periods when the basin was mostly submarine; and (iii) transient flows associated with fault rupture during periods of transpression. These hydrologic models help to compare and contrast a variety of hypotheses concerning deep fluid migration and the origin of base metal ores in the McArthur Basin. The numerical results exhibit a strong structural control on fluid flow caused by the north‐trending fault systems that characterize the Batten Fault Zone. As a result, fluids descend to depths of a few kilometers along the western side, migrate laterally to the east through the clastic and volcanic aquifers of the upper Tawallah and lowest McArthur Groups, and then ascend along the eastern side of the fault zone. This recharge–discharge pattern dominates all of the hydrogeologic models. The basin‐wide flow pattern suggests that Na–Ca–Cl brines acquired base metals in the deepest levels of the basin stratigraphy as the fluids migrated eastwards through the aquifer system. Upward flow was relatively rapid along the Emu Fault Zone, so much so that fluid temperatures likely approached 130°C in the muddy sediments near the sea floor due to upward flow and venting at the HYC (‘Here’s Your Chance'). Transient pulses of flow characterized periods of transpressional stress and subsequent faulting may have punctuated the basin history. Large‐scale free convection, however, characterized notably long periods of diagenesis and ore mineralization during the Proterozoic in the McArthur Basin.     

当代国外城市模型研究的进展与未来

由于城市的复杂性、系统性和不可逆性,对城市问题的诊断与解决也必须运用系统化、模型化的方法。本文综述了1980年代以来,城市模型研究在基础理论、模型方法、技术和研究内容上新的发展。认为当代城市模型研究存在的突出问题是:仍然沿用工业化城市的经济社会规律,研究已经被信息化和全球化所深刻影响的城市;复杂性科学理论的综合性不够;GIS与其它模型的集成度有待提高。未来城市模型的研究应着重关注新的城市变化,综合运用复杂性科学的理论与方法,强化以GIS为平台的计算机技术。     

School Choice as a Latent Variable: Estimating the “Complier Average Causal Effect” of Vouchers in Charlotte

Randomized field trials of school voucher policy interventions face major statistical hurdles in the measurement of a voucher effect on student achievement. Selection bias undermines the benefits of randomization when the treatment, a random offer of a voucher, is declined by participants who systematically differ from those who accept. This article argues that the complier average causal effect (CACE) is the parameter of interest in voucher evaluations. As an example, the CACE is estimated using data from a small, one‐year field trial of vouchers in Charlotte, NC. In this estimation, voucher impacts in Charlotte are positive, but appear to be moderated by the probability of compliance. For math achievement, maximum likelihood CACE estimates are smaller and insignificant compared to intention to treat and instrumental variable estimates of mean treatment effects.     

中国家庭出游决策现状及旅游市场营销建议研究——以北京为例

根据旅游决策划分的三个阶段,通过在北京居民区及学校进行问卷调查的方法,分析了核心家庭、夫妻二人家庭和三代同堂家庭的决策模式与家庭成员的决策内容。研究表明,在北京夫妻共同主导型决策模式占比例最大,其次为妻子主导型决策模式。但不同结构的家庭旅游决策模式不同,且不同的家庭成员决定着不同方面的出游决策内容。最后针对中国家庭出游决策模式及家庭成员出游决策内容为旅游目的地市场营销提出了相关建议。     

旅游目的地竞争力定量评价综述

近年来目的地旅游竞争力正逐渐成为国内外研究的热点领域。本文目的是通过梳理与回顾相关研究文献,对旅游目的地竞争力主要评价模型、变量选择、模型应用、优势与限制以及对未来研究趋向进行深入探讨。     

Beyond the carrot and stick: the political economy of US military aid to China, 1945–1951

By applying the rent-seeking assumption and sifting through both the archival materials and published historical documents, this article revisits the US–China relationship during the Chinese Civil War (1946–1949) and the early Cold War period, when the United States was caught in the conundrum of aiding the Chinese Nationalists led by Chiang Kai-shek. As military aid is usually regarded as an important representation of broader economic aid, this research mainly concentrates on the US military assistance to postwar Nationalist China. This topic is important, as it signifies a direct American involvement in the Chinese Civil War, when the influence of the United States in postwar world politics was overwhelmingly predominant. As a result, postwar Chinese history might be reevaluated in a broader global postwar context. In addition, this article also tells the story about rent-seeking behaviors in the complicated US–China military relations during the early Cold War period at both micro and macro levels. When it came to US military assistance to China, the formulation of policy was perennially in the name of one's best interest.     

当代加拿大华人精英参政模型分析

论文将当代加拿大华人精英的参政情况概括为五种模型：选举型和委任型、全国型和地方型、象征型和实在型、主流政党型和华人政党型及华人选票型和非华人选票型,并运用这五种参政模型对当代加拿大华人精英的参政情况进行归纳与分析。认为华人精英无论采取何种模型参与加拿大政治,只要能成功进入主流社会,对改善华人在加拿大社会的公共政治形象,提高他们的社会政治地位和维护他们的合法权利都十分有益,对华裔新生代未来参与政治的热情也是一个激励。     

Baseline Models for Two‐Mode Social Network Data

Baseline models have been used in the analysis of social networks as a way to understand how empirical networks differ from “random” ones. For the purposes of social network analysis, a “random” network is one chosen—at random—from a population of possible graphs derived from a given generating function. Although these principled hypothesis tests have a long history, many of their properties and extensions to multiple data structures—here, specifically two‐mode data—have been overlooked. This article focused on applications of different baseline models to two data sets: donations and voting of the 111th U.S. Congress, and organizations involved in forums on watershed policy in San Francisco, USA. Tests using each data set, but with different baseline reference distributions, will illustrate the range of possible questions baseline models can address and the differences between them. The ability to apply different models and generate a constellation of results provides a deeper understanding of the structure of the system.     

Path dependence in the evolution of resort governance models in China

Governance models have attracted growing academic interest in the recent literature on resort development. In transitional China, resort governance models have been evolving in step with the country's marketization and modernization. This paper reports on a case study of the governance models relating to the Yalong Bay National Tourist Resort (YBNTR), one of China's most famous resort destinations. Two approaches to data collection were used in this study: secondary data from local governmental agencies and companies, and in-depth interviews with 18 key personnel involved with the resort. This study, by reviewing the evolution of YBNTR governance models, shows that a path-dependence context impacted on its evolution. By integrating the ‘road juncture’ approach to understanding path dependence with elements of Institutional Costs Theory, a proposition for the formative mechanism of path dependence in the evolution of the YBNTR governance model was formulated and tested. It is demonstrated that, at the key time junctures for decisions on YBNTR governance models, influential actors (e.g. local government, the developers, and nearby communities) were theoretically provided with multiple choices. However, the existence of institutional costs structured the potential options of the actors in two ways: on the one hand, the opportunity costs of giving up the previous governance model had to be calculated and taken into account; and on the other, the potential additional costs of adopting a new governance model also had to be calculated and considered. Additionally, institutional legacy and interest group (the main developer, nearby villagers) bargaining capacities also influenced institutional costs and returns in different directions and to varying extents. These also conditioned the future directions and trajectories in the evolution of appropriate governance models. This study expands previous theories of path dependence in institutional change, and thus contributes to the understanding of institutional changes in Hainan and transitional China.