Yearly comparisons of the martian polar caps: 1999-2003 Mars Orbiter Camera observations     

Jennifer L. Benson  Philip B. James 《Icarus》2005,174(2):513-523

The Mars Global Surveyor Mars Orbiter Camera wide-angle cameras were used to obtain images of the north and south seasonal and residual polar caps between 1999 and 2003. Wide-angle red camera images were used in assembling mosaics of the north and south polar recessions and regression rates were measured and compared. There are small variations in the north polar recession between 2000 and 2002, especially between LS=7° and LS=50°, however there is no evidence for the plateau in the recession curves that has been observed in some prior years. The south polar recession changes very little from year to year, and the 2001 dust storm had little if any effect on the average cap recession that year. Albedo values of the geographic north pole were measured using wide-angle red and blue camera images, and the residual south polar cap configuration was compared between the three years observed by MOC. The albedo of the geographic north pole generally varies between 0.5 and 0.6 as measured from MOC wide-angle red camera images. There were only minor variations near the edges of the residual south polar cap between the three years examined.  相似文献   

THE SOURCES OF REGIONAL ELDERLY POPULATION GROWTH: MIGRATION AND AGING-IN-PLACE *     

Andrei Rogers  Jennifer Woodward 《The Professional geographer》1988,40(4):450-459

A region's elderly population has two sources of growth: net migration and the net aging-in-place of its resident population. This paper outlines a method for identifying the projected relative contribution of these two sources of elderly population growth over time, and illustrates it with data for the states of Arizona, California, Florida, Illinois, and New York. The sources of elderly population growth differ between regions and over time.  相似文献   

“Progressive port Elizabeth”: Liberal politics,local economic development and the territorial basis of racial domination, 1923–1935     

Jennifer Robinson 《GeoJournal》1990,22(3):293-303

The growth of state capacity with respect to African people in South Africa's cities, while an ambition of many local and central state managers, was secured only in the face of conflicts within the state and between the state and the people. This paper examines some of the specific social processes which shaped the segregated form of African settlement and administration in Port Elizabeth between 1923–35. The aim is to interpret how the unique configuration of social and economic conditions in Port Elizabeth both fed into and depended upon an as yet imperfectly implemented strategy for the government and control of the city's African populace. Issues of concern include the nature of the administration in the New Brighton Location, the influence of liberal politics on Location strategy and the impact of the local council's efforts at place entrepreneurialism on residential development and urban government.  相似文献   

Political orientation and climate concern shape visual attention to climate change     

Jennifer C. Whitman  Jiaying Zhao  Kevin H. Roberts  Rebecca M. Todd 《Climatic change》2018,147(3-4):383-394

Despite the scientific consensus, there is widespread public controversy about climate change. Previous explanations focused on interpretations hampered by political bias or insufficient knowledge of climate facts. We propose that public views of climate change may also be related to an attentional bias at a more basic level of cognitive processing. We hypothesized that selective visual attention towards or away from climate-related information would be associated with climate concern. To test prioritization of climate-related stimuli under conditions of limited attention, we asked participants to identify climate-related and neutral words within a rapid stream of stimuli. Undergraduate students attended to climate-related words more readily than neutral words. This attentional prioritization correlated with self-rated climate concern. We then examined this relationship in a more diverse community sample. Principal component analysis of survey data in the community sample revealed a component indexing a relationship between climate concern and political orientation. That component was correlated with the degree of selective inattention to climate-related words. Our findings suggest that climate-related communications may be most effective if tailored in a manner accounting for how attentional priorities differ between audiences—particularly those with different political orientations.  相似文献   

From Soil Pollution to “Cadmium Rice” to Public Health Impacts: An Interdisciplinary Analysis of Influencing Factors and Possible Responses     

Jennifer HOLDAWAY  WANG Wuyi 《资源与生态学报(英文版)》2018,9(1):1-12

This article discusses the causes of the contamination of rice with cadmium in China and considers what we know about the severity of the problem. It argues that it is misleading to extrapolate simply from levels of cadmium in soil to health risks, because the uptake of cadmium by crops and the health impacts of the metal are affected by multiple factors. These include not only background levels of cadmium and pollution from mining and industry, but also soil quality, climatic conditions and the type and variety of crops grown. Social and cultural factors, including dietary habits, other exposure sources, nutritional quality and general health status will also affect the intake of cadmium and the severity of health impacts. For these reasons we argue that interdisciplinary analysis is crucial to a better understanding of patterns of risk to health from cadmium pollution, and to the design of effective responsive measures.  相似文献   

Coal combustion by-product quality at two stoker boilers: Coal source vs. fly ash collection system design     

Sarah M. Mardon  James C. Hower  Jennifer M.K. O'Keefe  Maria N. Marks  Daniel H. Hedges 《International Journal of Coal Geology》2008,75(4):248-254

Fly ashes from two stoker boilers burning Pennsylvanian Eastern Kentucky high volatile A bituminous coal blends were examined for their petrology and chemistry. The source coals have similar trace element contents. One of the ash collection systems was retrofitted with a baghouse (fabric filter) system, collecting a finer fly ash at a cooler flue gas temperature than the plant that has not been reconfigured. The baghouse ash has a markedly higher trace element content than the coarser fly ash from the other plant. The enhanced trace element content is most notable in the As concentration, reaching nearly 9000 ppm (ash basis) for one of the collection units. Differences in the ash chemistry are not due to any substantial differences in the coal source, even though the coal sources were from different counties and from different coal beds, but rather to the improved pollution control system in the steam plant with the higher trace element contents.  相似文献   

Diurnal variations in,and influences on,concentrations of particulate and dissolved arsenic and metals in the mildly alkaline Wallkill River,New Jersey,USA     

Julia L. Barringer  Timothy P. Wilson  Zoltan Szabo  Jennifer L. Bonin  Jeffrey M. Fischer  Nicholas P. Smith 《Environmental Geology》2008,53(6):1183-1199

Diurnal variations in particulate and dissolved As and metal concentrations were observed in mildly alkaline water from a wetlands site on the Wallkill River in northwestern New Jersey. The site, underlain by glacial sediments over dolomite bedrock, is 10 km downstream from a mined area of the Franklin Marble, host to Zn ores, also As and Mn minerals. In mid-September 2005, maxima and minima in dissolved-oxygen-concentration and pH, typically caused by photosynthesis and respiration, occurred at 2000 and 0800 hours. Concentrations of dissolved As (1.52–1.95 μg/L) peaked at dusk (2000 hours), whereas dissolved Mn and Zn concentrations (76.5–96.9 and 8.55–12.8 μg/L, respectively) were lowest at dusk and peaked at 1000 hours. These opposing cycles probably reflect sorption and desorption of As (an anion), and Mn and Zn (cations) as pH varied throughout the 24-h period. Doubly-peaked cycles of B, Cl, SO₄, and nutrients also were observed; these may result from upstream discharges of septic-system effluent. Both recoverable amd particulate Al, Fe, Mn, and Zn concentrations peaked between 0200 and 0600 hours. The particulate metals cycle, with perturbations at 0400 hours, may be influenced by biological activity.  相似文献   

Geography of advice seeking     

A. Patel  N.J. Balmer  P. Pleasence 《Geoforum》2008,39(6):2084-2096

Despite limited research on access to advice services, it has long been assumed that access is related to geographic proximity [e.g. Blacksell, M., 1990. Social Justice and access to legal services: a geographic perspective. Geoforum 21 (4), 489–502]. The current study uses data from the English and Welsh Civil and Social Justice Survey, a large-scale nationally representative survey of respondents’ experience of and response to civil and social justice problems [Pleasence, P., 2006. Causes of Action: Civil Law and Social Justice, second ed. TSO, Norwich], to examine the impact of proximity to mainstream advice services on awareness and utilisation of services. In general, proximity of advice services had a relatively modest impact on both awareness and advice seeking. However, proximity did impact upon mode of contact and there was some evidence of difference in strategy (particularly more inaction) for isolated individuals without use of motorised transport. The suitability of different modes of advice provision for particular demographic groups are discussed, as well as implications for service delivery.  相似文献   

Intransigent LA     

Jennifer Wolch 《Geoforum》2008,39(2):543-545

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Local Governance for Social Sustainability: equity as a strategic response to neoliberal constraints in food security initiatives     

Christine Slade  Jennifer Carter 《The Australian geographer》2017,48(3):385-399

Scholarly literature recognises the importance of social sustainability as part of the wider sustainability agenda. A wide array of concepts such as equity, social justice, democratic government, social inclusion, social capital and quality of life are thought to constitute social sustainability. Local governments are charged with delivering social programs and services to their constituency, but market logics and performance-based institutional cultures, along with limited authority and funding, constrain their capacity to respond to new initiatives. We analyse two case studies in Victoria, Australia, to explore how elements of social sustainability are articulated and operationalised within local government. Each case study involved State-level and local government partnerships in health-promotion initiatives to improve food security. Analysis was conducted on 50 primary policy documents, 22 secondary data documents and 27 interviews. Findings reveal that a systems-based or integrated approach to social sustainability was not workable but not completely ineffective. Equity was prioritised by local government in both case studies, and well acknowledged as interconnected with other social goals. Although constrained in its capacity to deliver new initiatives, local government responded to neoliberalising ideologies, as well as its constituency, by strategically focusing on a particular goal, such as equity.  相似文献