Experiencing agricultural failure: Internal migration, tourism and local perceptions of regional change in the Yucatan     

Lindsey Carte  Erin Daley 《Geoforum》2010,41(5):700-710

In response to a growing body of literature encouraging geographers to present textured, regional case studies that demonstrate how neoliberalism functions at diverse scales, this article presents a nuanced account of neoliberalism in Mexico’s Yucatan peninsula. The study seeks to illustrate how neoliberal reforms to agriculture and ongoing neoliberal tourism development in the Yucatecan state of Quintana Roo intersect to create a unique regional context for migration between the state’s rural areas and Mexico’s largest planned tourism development zone in Cancun. The research presented is based on a series of in-depth qualitative interviews that took place in 2003 with rural residents and regional migrants working in Cancun. Through the employment of an experiential definition of neoliberalism, grounded in the lived experiences and perceptions of study participants, the article suggests that rural-urban tourist pole migration is the result of a complex negotiation of the region’s neoliberal landscape. The article argues that rural residents’ and migrants’ perceptions of the failure of agriculture as a livelihood is shaped relative to the perceived success of the tourism industry and better livelihood opportunities in Cancun. These widespread perceptions of agricultural failure in the Yucatan peninsula are constructed not solely in response to local conditions but rather in response to the overall regional outcome of neoliberal economic restructuring initiatives which have negatively affected traditional agriculture in the rural sphere while privileging tourism development in the urban sphere centered in Cancun.  相似文献   

A shallow subsurface controlled release facility in Bozeman, Montana, USA, for testing near surface CO2 detection techniques and transport models   总被引：1，自引：0，他引：1  

Lee H. Spangler  Laura M. Dobeck  Kevin S. Repasky  Amin R. Nehrir  Seth D. Humphries  Jamie L. Barr  Charlie J. Keith  Joseph A. Shaw  Joshua H. Rouse  Alfred B. Cunningham  Sally M. Benson  Curtis M. Oldenburg  Jennifer L. Lewicki  Arthur W. Wells  J. Rodney Diehl  Brian R. Strazisar  Julianna E. Fessenden  Thom A. Rahn  James E. Amonette  Jon L. Barr  William L. Pickles  James D. Jacobson  Eli A. Silver  Erin J. Male  Henry W. Rauch  Kadie S. Gullickson  Robert Trautz  Yousif Kharaka  Jens Birkholzer  Lucien Wielopolski 《Environmental Earth Sciences》2010,60(2):227-239

A controlled field pilot has been developed in Bozeman, Montana, USA, to study near surface CO₂ transport and detection technologies. A slotted horizontal well divided into six zones was installed in the shallow subsurface. The scale and CO₂ release rates were chosen to be relevant to developing monitoring strategies for geological carbon storage. The field site was characterized before injection, and CO₂ transport and concentrations in saturated soil and the vadose zone were modeled. Controlled releases of CO₂ from the horizontal well were performed in the summers of 2007 and 2008, and collaborators from six national labs, three universities, and the U.S. Geological Survey investigated movement of CO₂ through the soil, water, plants, and air with a wide range of near surface detection techniques. An overview of these results will be presented.  相似文献   

Experimental implementation and verification of multi‐degrees‐of‐freedom effective force testing          下载免费PDF全文

Narutoshi Nakata  Erin Krug  Aaron King 《地震工程与结构动力学》2014,43(3):413-428

This paper presents an experimental implementation and verification of multi‐degrees‐of‐freedom effective force testing (MDOF‐EFT). An experimental setup that consists of a two‐degrees‐of‐freedom structural system and two hydraulic actuators at the Johns Hopkins University was utilized in this study. First, experimental system identification was performed to develop compatible analytical models for the multi‐input and multi‐output systems. Dynamics of the control plant, that is, the valve‐to‐force relations, were modeled with a rational polynomial transfer function matrix and delay components. By using the analytical model, a centralized decoupling loop‐shaping force feedback controller was designed such that the forces are uncoupled and the loop transfer functions have desirable dynamic characteristics in the frequency domain. Then, a series of harmonic force and earthquake simulation tests were performed to assess capabilities and limitations of MDOF‐EFT. Experimental results showed that the dynamic forces in the two actuators were accurately controlled to provide tracking while the system was stable and robust for the entire period of the experiment. Furthermore, earthquake simulation tests with increased levels of the reference forces demonstrated the feasibility of MDOF‐EFT with highly nonlinear test structures. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

武隆喀斯特及其地壳抬升性质解读   总被引：5，自引：3，他引：2  

朱学稳  陈伟海  Erin Lynch 《中国岩溶》2007,26(2):119-125

在特定的地质结构及峡谷水文网分布条件下,武隆喀斯特以独立发育的诸多包气带喀斯特系统为主要特征,而且不同喀斯特系统间的结构与形态组成差异甚大。喀斯特系统的分析可解读相适应的地壳运动性质是: 自新近纪末期以来,地壳运动只有上升没有下降过程;前80～ 100万年为持续上升,即几乎没有相对稳定的经历;继后是间歇性抬升与相对稳定,似以后者占优;分布于深切峡谷相对高度150～ 300m间的大型成层性洞穴,主要发育于中更新世;晚更新世以来的上升与相对稳定彼此平分秋色。   相似文献   

Water Education for Sustainability: Criteria and Recommendations     

Kelli L. Larson  Erin N. Redman 《社会与自然资源》2014,27(11):1213-1222

This article applies behavioral theories, knowledge-to-action frameworks, and educational pedagogy to the case study of water education programs in metropolitan Phoenix, AZ. First, we describe three criteria for sustainable behavior change through education. Next, we demonstrate how water education programs in Phoenix have employed inadequate approaches to reduce resource consumption relative to the criteria. Finally, we offer recommendations to enhance the effectiveness of educational initiatives directed toward transformative change for sustainability. Central insights involve incorporating diverse knowledge domains, using interactive educational techniques, and tailoring programs to specific actions and relevant targeted populations.  相似文献   

Future makers or future takers? A scenario analysis of climate change and the Great Barrier Reef     

Erin Bohensky  James R.A. ButlerRobert Costanza  Iris BohnetAurélie Delisle  Katharina FabriciusMargaret Gooch  Ida KubiszewskiGeorge Lukacs  Petina PertEric Wolanski 《Global Environmental Change》2011,21(3):876-893

The extent to which nations and regions can actively shape the future or must passively respond to global forces is a topic of relevance to current discourses on climate change. In Australia, climate change has been identified as the greatest threat to the ecological resilience of the Great Barrier Reef, but is exacerbated by regional and local pressures. We undertook a scenario analysis to explore how two key uncertainties may influence these threats and their impact on the Great Barrier Reef and adjacent catchments in 2100: whether (1) global development and (2) Australian development is defined and pursued primarily in terms of economic growth or broader concepts of human well-being and environmental sustainability, and in turn, how climate change is managed and mitigated. We compared the implications of four scenarios for marine and terrestrial ecosystem services and human well-being. The results suggest that while regional actions can partially offset global inaction on climate change until about mid-century, there are probable threshold levels for marine ecosystems, beyond which the Great Barrier Reef will become a fundamentally different system by 2100 if climate change is not curtailed. Management that can respond to pressures at both global and regional scales will be needed to maintain the full range of ecosystem services. Modest improvements in human well-being appear possible even while ecosystem services decline, but only where regional management is strong. The future of the region depends largely on whether national and regional decision-makers choose to be active future ‘makers’ or passive future ‘takers’ in responding to global drivers of change. We conclude by discussing potential avenues for using these scenarios further with the Great Barrier Reef region's stakeholders.  相似文献   

黔西南卡林型金矿床与区域古油藏的关系:来自流体包裹体气相组成和沥青拉曼光谱特征的证据   总被引：2，自引：2，他引：0  

靳晓野  李建威  HOFSTRA Albert  MARSH Erin  刘建中  杨梧 《岩石学报》2016,32(11):3295-3311

黔西南地区是世界第二大卡林型金矿床集中区,同时也发育有大量古油藏,二者空间关系密切,但是否具有成因联系目前尚不清楚且存在较大争议。本文报道该区典型金矿床与成矿有关的热液矿物中流体包裹体的气相组成和高品位金矿石中沥青的激光拉曼光谱分析结果,以探讨含有机质流体与金成矿作用之间的关系。研究表明,虽然含砷富金黄铁矿、石英、方解石、萤石和雄黄等热液矿物形成于不同的成矿阶段,但其中流体包裹体的有机气相组分种类、含量及相对比例整体较为一致,表明成矿流体中的有机络离子团在成矿作用过程中没有发生明显的分解或重组,进而说明黔西南卡林型金矿成矿作用过程中有机质并未以有机络离子团的形式对金进行有效搬运或其搬运金的能力非常有限。在N2/Ar-CO2/CH4流体来源判别图解中,各蚀变矿物中的流体包裹体气相组成主要落在循环的大气降水区域,经大气水区域向岩浆流体区域延伸,整体上构成一条非常好的线性分布趋势,暗示成矿流体可能起源于深部岩浆但在演化过程中有大量循环大气水的加入。水银洞金矿床的1件石英样品偏离上述趋势线并向有机流体方向偏移,可能反映了流体迁移过程中有机质的加入。该区金矿床的矿石中均不同程度地发育浸染状沥青,不同矿床中沥青的激光拉曼光谱特征基本一致,说明该区金矿床中的沥青具有相同成因。根据沥青激光拉曼光谱特征地质温度计反演计算的成矿早阶段流体温度为317~336℃,明显高于区域古地温温度(160~250℃)以及区域古油藏的流体包裹体均一温度(73~175℃),说明该区卡林型金矿床的成矿热源与区域古地温无关。对区域地质及近年来地球物理与地球化学最新成果的综合分析表明,该区卡林型金矿床可能是叠加在区域古地温场之上的深部岩浆活动远端低温热液成矿作用的产物,与金矿床空间关系密切的有机质可能为来自先存古油藏并沿控矿构造发生逃逸的油气物质裂解产物,金成矿与区域古油藏之间不存在成因联系。  相似文献   

Nitrogen Retention in Salt Marsh Systems Across Nutrient-Enrichment,Elevation, and Precipitation Regimes: a Multiple-Stressor Experiment     

Autumn Oczkowski  Cathleen Wigand  Alana Hanson  Erin Markham  Kenneth M. Miller  Roxanne Johnson 《Estuaries and Coasts》2016,39(1):68-81

  相似文献   

Crystal Size Distributions and Scaling Laws in the Quantification of Igneous Textures   总被引：7，自引：2，他引：5  

ZIEG  M. J.; MARSH  B. D. 《Journal of Petrology》2002,43(1):85-101

This study demonstrates the value of the combined use of scalinganalysis and crystal size distribution (CSD) measurements inthe interpretation of igneous textures and outlines applicationsof these methods to other fundamentally important problems.Theoretical calculations and measurements of natural samplesare used to characterize the relationship between igneous textureand cooling history. The total number (N_T) and mean length (  相似文献   

Isotopic and petrographic evidence for young Martian basalts     

Erin L. Walton  Simon P. Kelley 《Geochimica et cosmochimica acta》2008,72(23):5819-5837

Radiometric age data for shergottites yield ages of 4.0 Ga and 180-575 Ma; the interpretation of these ages has been, and remains, a subject of debate. Here, we present new ³⁹Ar-⁴⁰Ar laser probe data on lherzolitic shergottites Allan Hills (ALH) 77005 and Northwest Africa (NWA) 1950. These two meteorites are genetically related, but display very different degrees of shock damage. On a plot of ⁴⁰Ar/³⁶Ar versus ³⁹Ar/³⁶Ar, the more strongly shocked ALH 77005 (45-55 GPa) does not yield an array of values indicating an isochron, but the data are highly scattered with the shock melts yielding ⁴⁰Ar/³⁶Ar ratios of 1600-2026. Apparent ages calculated from these extractions range from 374-8183 Ma, with 50% of the data, particularly from the shock melts, yielding impossibly old ages (>4.567 Ga). On the same plot, extractions from igneous minerals in the less shocked NWA 1950 (30-44 GPa) yield a fitted age of 382 ± 36 Ma. Argon extractions from the shock melts are well distinguished from minerals, with the melts exhibiting the highest ⁴⁰Ar/³⁶Ar ratios (1260-1488) and the oldest apparent ages. Laser step heating was also performed on maskelynite separates from NWA 1950 yielding ages of 1000 Ma at the lowest release temperatures, and ages of 360 and 362 Ma at higher temperature steps. Stepped heating data from previous studies have yielded ages of 500 and 700 Ma to 1.7 Ga for ALH 77005 maskelynite separates. If the ages obtained from igneous minerals represent undegassed argon from an ancient (4.0 Ga) rock, then the ages are expected to anticorrelate with the degree of shock heating. The data do not support this inference. Our data support young crystallization ages for minerals and Martian atmosphere as the origin of excess ⁴⁰Ar in the shock melts.The shock features of shergottites are also reviewed in the context of what is known of the geologic history of the Martian surface through remote observation. The oldest, most heavily cratered surfaces of Mars are thought to be ?4.0 Ga; we contend that ancient rocks from Mars (Noachian >3.5 Ga) are likely to record multiple impact events reflecting megaregolith formation and the cumulative effects of erosion and aqueous alteration occurring during or since that era. Young rocks (Late Amazonian, <0.6 Ga) should record a relatively simple history of emplacement and ejection from the near surface. We show that although shergottites are strongly shocked, they are relatively pristine crystalline igneous rocks and not pervasively altered breccias. The petrography of shergottites is at odds with an ancient age interpretation. A model in which young coherent rocks are preferentially sampled by hypervelocity impact because of material strength is considered highly plausible.  相似文献