Emily Dix, palaeobotanist – a promising career cut short     

Cynthia Burek 《Geology Today》2005,21(4):144-145

Emily Dix, the Coal Measures palaeobotanist, was born on 21 May 1904. She was one of four daughters in a family of five children brought up in Penclawdd – a South Welsh cockling port then surrounded by coal and copper smelting industries near Swansea. Emily was a bright and gregarious girl, gaining at the age of 18 the Central Welsh Board Higher Certificate in History, Botany and Geography with distinctions in history and botany. Her success was an indication of what was to come.  相似文献   

Intertidal distribution and feeding habits of the mud crab,Eurytium limosum     

Ronald T. Kneib  Cynthia A. Weeks 《Estuaries and Coasts》1990,13(4):462-468

Average summer densities of the xanthid crab,Eurytium limosum, in an intertidal salt marsh on Sapelo Island, Georgia were in the range of 7.5 to 80.0 individuals m^?2. Crab densities were lowest in wet, lowlying marsh and highest in well-drained creekbank and mussel mound habitats. An analysis of crab stomach contents indicated that feeding occurred mostly around high tide, especially at night. Although the diet included some plant material,Eurytium limosum is primarily predatory and consumed crabs, polychaetes, ostracods, bivalves, and snails. In the laboratory, under simulated low-tide field conditions, both small (11–15 mm carapace width) and large (20–37 mm CW)Eurytium could capture and consume young killifish (Fundulus heteroclitus). Large crabs consumed the entire size range (7–19 mm total length) of larval/juvenile fish offered, but small crabs did not prey upon fish >11.5 mm TL. The potential importance ofE. limosum as a predator on young killifish may not be realized in the field because alternative prey are available and the crabs feed primarily at high tide, when young killifish are dispersed in the water column and are less vulnerable to benthic predators.  相似文献   

Erratum:The Local Articulation of Policy Conflict: Land Use,Environment, and Amerindian Rights in Eastern Amazonia     

Cynthia S. Simmons 《The Professional geographer》2002,54(3):479-479

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Assessing Winter Wheat Responses to Climate Change Scenarios: A Simulation Study in the U.S. Great Plains   总被引：3，自引：0，他引：3  

Albert Weiss  Cynthia J. Hays  Jaepil Won 《Climatic change》2003,58(1-2):119-147

Hard red winter wheat (Triticum aestivum L.) is a major crop in the Great Plains region of the U.S. The goal of this assessment effort was to investigate the influence of two contrasting global climate change projections (U.K. Hadley Center for Climate Prediction and Research and Canadian Centre for Climate Modelling and Analysis) on the yield and percent kernel nitrogen content of winter wheat at three locations in Nebraska. These three locations represent sub-humid and semi arid areas and the transition between these areas and are also representative of major portions of the winter wheat growing areas of the central Great Plains. Climate scenarios based on each of the projections for each location were developed using the LARS-WG weather generator along with data from automated weather stations. CERES-Wheat was used to simulate the responses for two contrasting cultivars of wheat using two sowing dates. The first sowing date represented current sowing dates appropriate for each location. The second sowing date was later and represents the approximate date when the mean air temperature from the climate scenarios is the same as the mean air temperature from the actual climate data at the current sowing dates. The yield and percent kernel nitrogen content using the two climate scenarios generally decrease going from the sub-humid eastern to the semi arid western parts of Nebraska. Results from these simulations indicate that yield and percent kernel nitrogen content using the two climate scenarios could not both be maintained at levels currently simulated. Protein content (directly related to kernel nitrogen content) and end-use quality are the primary determinants for the use of hard red winter wheat in baked goods. Nitrogen management and new cultivars, which can enhance the uptake and translocation of nitrogen, will be proactive steps to meet the challenges of global climate change as represented by these climate scenarios.  相似文献   

Continental Rifts: Evolution, Structure and Tectonics     

Cynthia Ebinger 《Geophysical Journal International》1997,129(2):475-475

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Continental break-up: The East African perspective   总被引：1，自引：0，他引：1  

Cynthia Ebinger 《Astronomy& Geophysics》2005,46(2):2.16-2.21

Cynthia Ebinger discusses the evolution of continental rifts through the example of the East African Rift system, in the Bullerwell Lecture, given at the European Union of Geosciences meeting in Nice, April 2004.  相似文献   

Territorializing land conflict: Space,place, and contentious politics in the Brazilian Amazon     

Cynthia S. Simmons 《GeoJournal》2005,64(4):307-317

Brazil possesses a long history of violent struggle for land, and its most recent phase is occurring predominantly in the Amazon Basin. Consequently, this paper attempts to territorialize land conflict in the Brazilian Amazon, and in so doing, to illuminate the place-specific intersection of historic social, political, and economic circumstance that created a violent landscape in the so-called “South of Pará.” The paper’s premise is that such conflict can be best viewed as resulting from a dialectic between general social processes operating across spatial scales, which create necessary conditions for conflict, and place-specific historical circumstances that transform necessary into sufficient conditions. The paper presents a framework integrating the theory of contentious politics and literatures addressing violence associated with the Amazonian frontier and with resource scarcity (and abundance). The discussion and theoretical application deconstruct the environmental, cognitive, and relational mechanisms that created violence in the South of Pará, and set the stage for the Eldorado dos Carajás massacre in April of 1996.  相似文献   

Bound and mobile soil water isotope ratios are affected by soil texture and mineralogy,whereas extraction method influences their measurement     

Rachel E. Adams  Ayumi Hyodo  Toby SantaMaria  Cynthia L. Wright  Thomas W. Boutton  Jason B. West 《水文研究》2020,34(4):991-1003

Questions persist about interpreting isotope ratios of bound and mobile soil water pools, particularly relative to clay content and extraction conditions. Interactions between pools and resulting extracted water isotope composition are presumably related to soil texture, yet few studies have manipulated the bound pool to understand its influence on soil water processes. Using a series of drying and spiking experiments, we effectively labelled bound and mobile water pools in soils with varying clay content. Soils were first vacuum dried to remove residual water, which was then replaced with heavy isotope-enriched water prior to oven drying and spiking with heavy isotope-depleted water. Water was extracted via centrifugation or cryogenic vacuum distillation (at four temperatures) and analysed for oxygen and hydrogen isotope ratios via isotope ratio mass spectrometry. Water from centrifuged samples fell along a mixing line between the two added waters but was more enriched in heavy isotopes than the depleted label, demonstrating that despite oven drying, a residual pool remains and mixes with the mobile water. Soils with higher clay + silt content appeared to have a larger bound pool. Water from vacuum distillation samples have a significant temperature effect, with high temperature extractions yielding progressively more heavy isotope-enriched values, suggesting that Rayleigh fractionation occurred at low temperatures in the vacuum line. By distinctly labelling bound and mobile soil water pools, we detected interactions between the two that were dependent on soil texture. Although neither extraction method appeared to completely extract the combined bound and mobile (total water) pool, centrifugation and high temperature cryogenic vacuum distillations were comparable for both δ²H and δ¹⁸O of soil water isotope ratios.  相似文献   

Aeromagnetic interpretation in the south-central Zimbabwe Craton: (reappraisal of) crustal structure and tectonic implications     

Rubeni T. Ranganai  Kathryn A. Whaler  Cynthia J. Ebinger 《International Journal of Earth Sciences》2016,105(8):2175-2201

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A reassessment of the economic effects of global climate change on U.S. agriculture     

Richard M. Adams  Ronald A. Fleming  Ching-Chang Chang  Bruce A. McCarl  Cynthia Rosenzweig 《Climatic change》1995,30(2):147-167

This study uses recent GCM forecasts, improved plant science and water supply data and refined economic modeling capabilities to reassess the economic consequences of long-term climate change on U.S. agriculture. Changes in crop yields, crop water demand and irrigation water arising from climate change result in changes in economic welfare. Economic consequences of the three GCM scenarios are mixed; GISS and GFDL-QFlux result in aggregate economic gains, UKMO implies losses. As in previous studies, the yield enhancing effects of atmospheric CO₂ are an important determinant of potential economic consequences. Inclusion of changes in world food production and associated export changes generally have a positive affect on U.S. agriculture. As with previous studies, the magnitude of economic effects estimated here are a small percentage of U.S. agricultural value.  相似文献