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1.
Ibipo Johnston-Anumonwo 《The Professional geographer》1997,49(3):306-317
This study investigates whether women's short commutes should be interpreted as constrained or convenient work trips by examining how race, gender, travel mode, occupation, residential location, workplace location, and Inc.ome affect commuting time. The analysis is restricted to a sample of European American and African American male and female workers residing in Buffalo, New York, and the surrounding county using data drawn from the Public Use Microdata Samples of the 1990 U.S. census. Given the pervasive gender wage gap, women unsurprisingly have more compromised (short commutes to low-Inc.ome jobs) work trips than do men. Multivariate analysis reveals that among those who reverse commute to suburban locations, African American women have the longest work trips. 相似文献
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《The Professional geographer》2013,65(3):306-317
This study investigates whether women's short commutes should be interpreted as constrained or convenient work trips by examining how race, gender, travel mode, occupation, residential location, workplace location, and Inc.ome affect commuting time. The analysis is restricted to a sample of European American and African American male and female workers residing in Buffalo, New York, and the surrounding county using data drawn from the Public Use Microdata Samples of the 1990 U.S. census. Given the pervasive gender wage gap, women unsurprisingly have more compromised (short commutes to low-Inc.ome jobs) work trips than do men. Multivariate analysis reveals that among those who reverse commute to suburban locations, African American women have the longest work trips. 相似文献
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Spatial relationships among species, above-ground biomass, N, and P in degraded grasslands in Ordos Plateau, northwestern China 总被引：6，自引：0，他引：6
We chose five communities, representing a mild to severe gradient of grassland desertification in a semi-arid area of Ordos Plateau, northwestern China, to explore the spatial relationships among plant species, above-ground biomass (AGB), and plant nutrients (N and P). Community 1 (C1) was dominated by Stipa bungeana; Community 2 (C2) by a mix of S. bungeana and the shrub Artemisia ordosica; Community 3 (C3) by A. ordosica; Community 4 (C4) by a mix of Cynanchum komarovii and C. komorovii; and Community 5 (C5) by C. komorovii. Quantitative methods, including geostatistics, were used to compare community composition, structure, and indicators of ecosystem function (i.e. AGB, plant N and P) in five 16-m2 plots. The highest AGB, plant nitrogen (N) and plant phosphorus (P) were found in lightly degraded community C2. With increasing desertification effects from C3 to C5, the AGB, N, and P decreased significantly while plant density remained unchanged. The spatial variations of AGB were higher in shrub-dominated communities (C1 and C5) than in grass-dominated communities (C2–C4). Strong spatial relationships were detected within and among the communities, with stronger relationships between AGB and density than between AGB and species richness. Spatial patterns of plant N and P were different from those of AGB, reflecting different N and P contents of individual plants and different species that can redistribute soil resources in these communities. The AGB was positively correlated with soil nutrients (TOC, TN, TP, and IN), except for soil AP. We concluded that several specific aspects of ecosystem properties were directly associated with the conversion of the grass and shrub “functional types” in these degraded grasslands. 相似文献
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Ahmed M. El-Makky 《Natural Resources Research》2011,20(3):157-176
A prospective lithochemical survey (scale 1:50,000) was carried out at the Um Garayat gold mine area within the central wadi Allaqi shear zone. The metavolcanic samples were analyzed for Ti, P, Zr, Nb, Y, La, Nd, and Ce. The background and threshold values were determined using histograms, box-plots, and Q-mode cluster analysis. Discriminant analysis classifies the samples into four groups: Group 1 (Au mineralization) characterizes Phase III of the hydrothermal stage; Group 2 (Cu?CAu mineralization) characterizes Phases I and II; Groups 3 and 4 comprise the least altered samples. Cubic trend surface and residual maps display groups of elements: (P, Ti, Zr), (Nb, Y), and (La, Nd, Ce) each group has similar areal distribution pattern. R-mode factor analysis, using the cubic residuals, produces a model with three factors. Factors 1 (P, Ti, Zr) and 2 (Nb, Y) are referred to the magmatic minerals of the least altered volcanic rocks. In addition, Factor 1 associates with the Au-rich site at the shafts area, whereas Factor 2 is referred to albitization western to the shafts area with high contents of Nb and Y. In Factors 1 and 2, major P and Ti with traces Nb and Y are attributed to the accessories rutile, sphene, anatase, and calcite that were developed during propylitization as well as apatite and calcite-accompanying Phase I of the hydrothermal stage. Phosphorous could be considered as an indicator element for the Au mineralization at the study area. The principal elements of Factor 3 (La, Nd, Ce) associate with the Cu?CAu-rich site at the southern adits area, and attributed to the secondary Ca-bearing accessories calcite, sphene, and apatite. In general, these elements associate with the regional propylitization and the three phases of hydrothermal stage in zones of alkali metasomatism. In these alteration zones, La, Nd, and Ce could be used as indicators during geochemical exploration at the study area. In general, the secondary accessory minerals calcite, apatite, rutile, sphene, and anatase associating with zones of alkali metasomatism are significant carriers for the investigated elements. These accessories are possible indicators during geochemical exploration in the adjacent similar mineralizations of the central Allaqi shear zone area. 相似文献
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DIANA K DAVIS 《The Geographical journal》2006,172(2):88-105
Neoliberal restructuring in Morocco has been taking place for over twenty years. Beginning with a decade of structural adjustment, from the early 1980s to the early 1990s, parts of the public sector have been privatized, state services such as health care and education reduced, tariffs lowered and exports heavily promoted. In the dryland agricultural areas, a declensionist colonial environmental narrative has been appropriated to help justify and implement the neoliberal goals of land privatization and the intensification of agricultural production in the name of environmental protection. This paper contributes to areas of growing interest for geographers through an analysis of the underexplored relationship between neoliberalism and environmentalism, in the form of questionable environmental narratives, in Morocco. Land degradation in the dryland agricultural areas of Morocco is commonly blamed on overgrazing by local pastoralists despite existing documentation that suggests instead that ploughing of marginal lands and over-irrigation are the primary drivers of land degradation in the region. The deployment of this colonial environmental narrative of 'native improvidence' has facilitated an expansion of state power over collective rangelands under neoliberalism at the same time that government involvement has decreased in other sectors. The effects of neoliberalism in Morocco have been complex and thus the paper argues that current neoliberal reforms such as the Morocco–US free trade agreement need to be scrutinized carefully to prevent a further exacerbation of poverty as well as to prevent further land degradation in these areas. 相似文献
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This study examines the experiences of geography graduates who work in business, government, and nonprofit organizations. We analyzed 352 logs from eighty-two professionals detailing professional activities, challenges, and opportunities during one work week each month, over a period of six months. Our analysis explores interpersonal relationships and working conditions affecting participants’ progress toward work goals, workplace climate, and professional identity. Geographic information systems and technology accounted for more than half of the geographic skills respondents reported using on the job, and administrative and leadership factors were the most commonly cited types of transferable skills. Professional geographers value collaborative workplaces as well as opportunities to work independently with the confidence of their supervisors, and their sense of a professional identity is enhanced when they feel valued and are recognized for their work. Professional development activities are important because they reinforce geographers’ sense of positively contributing to their organizations, enhance interpersonal interactions, facilitate work on specific projects, and expand individuals’ knowledge and skills. Moreover, our findings suggest that nearly half of the reported workplace difficulties could potentially be reduced or eliminated as a result of more and better professional development. Nonetheless, many employers do not consistently provide opportunities for professional development to their employees. Based on our analysis, we contend that professional development is a beneficial investment for lifelong learning, from undergraduate and graduate education throughout the entire course of a professional career. 相似文献
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The recent (1950–1996) varve record from the proximal sediments in Nicolay Lake, Cornwall Island, Nunavut, Canada (77°46′ N,
94°40′ W) contains distinct subannual rhythmites. Deposition of these subannual rhythmites is due primarily to nival snow
melt, with additional sedimentary units resulting from major summer precipitation and subaqueous mass wasting events. In order
to evaluate the potential hydroclimatic signal contained in the varves from the unglacierized catchment, the nival deposition
record was estimated by delineating the initial subannual rhythmite within each varve. When the record is split into temporal
segments based on two phases that exhibit different sediment deposition patterns in the lake, the nival rhythmites are significantly
correlated to annual cumulative melting degree days (MDD) from the nearest weather station Isachsen (78°47′ N, 103°32′ W)
(1950–1962 AD and 1963–1977 AD with r = 0.55 and r = 0.82, respectively). A similar analysis with data from Resolute (74°43′ N,
94°59′ W) yields slightly weaker correlations (1950–1962 AD, r = 0.60; 1963–1994, r = 0.59). The strong positive correlation
with both the Isachsen and Resolute thermal records suggests that the paleoclimatic signal in the sediments reflects regional
climate conditions. Notably, the signal is strongest when the entire melt season is considered; weaker correlations with instrumental
weather records are associated with comparisons limited to the peak melt or early season melt periods. We attribute this to
the ongoing supply of snowmelt through the season in this polar region and the availability of sediment for transport throughout
the melt season. These results indicate that a high resolution hydroclimatic signal is present in the sediments from Nicolay
Lake and can be used for paleoclimate reconstruction provided sedimentary depositional controls are taken into account. 相似文献
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Johanna Hautala Maria Höyssä 《Norsk geografisk tidsskrift. Norwegian journal of geography》2017,71(5):269-287
The article presents a systematic review of 152 articles in which the concept of knowledge is applied and that are published in international human geography journals. As the importance of knowledge in society is increasing, especially economic geography has taken up the task of reviewing the concept or role of knowledge in geography. However, there is a need for a more nuanced understanding of knowledge in economic geography, drawing more broadly on human geographical research. The authors analyse how the concept of knowledge is understood and applied in contemporary human geography. Their results demonstrate four knowledge rationales: economic, policy, empowerment, and methodological. Each rationale and their combinations display a particular role and purpose for knowledge, as well as a distinct approach to space. Separately, each rationale provides several insights into a more nuanced understanding of specific aspects of knowledge. When combined, the four rationales offer a holistic overview of the field. The authors conclude that the empowerment rationale offers novel methodological choices towards a more nuanced understanding of knowledge in economic geography. 相似文献
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基于2007年中国已经开通地铁的六个城市的统计数据,选取影响城市内部地铁建设的因素,运用SPSS统计分析软件进行主成分分析,提取中国城市地铁建设的主要因子,在此基础上分析六个城市地铁建设影响因子的空间差异。结果表明:①中国城市地铁建设影响因素可归为三个主要因子,即城市建成区规模、政策支持和灵活、便捷的交通因子;城市现有的交通和二、三产业的发展状况;城市的经济实力和公路客运交通状况。②六个城市地铁建设的影响因素具有空间差异,按其驱动因子的个数,又可分为单因子驱动型,如北京、上海、广州和深圳,多因子驱动型,如天津和南京。 相似文献
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Vehicle-related hyperthermia is an unfortunate tragedy that leads to the accidental deaths of children each year. This research utilizes the most extensive dataset of child vehicle-related hyperthermia deaths in the United States, including 414 deaths between 1998 and 2008. Deaths follow a seasonal pattern, with a peak in July and no deaths in December or January. Also, deaths occurred over a wide range of temperature and radiation levels and across virtually all regions, although most of them took place across the southern United States. In particular, the Phoenix, Houston, Dallas, and Las Vegas metropolitan areas had the greatest number of deaths. We utilize our vehicle hyperthermia index (vhi) to compare expected deaths versus actual deaths in a metropolitan area, based on the number of children in the area who are under the age of five and on the frequency of hot days in the area. The vhi indicates that the Memphis, West Palm Beach-Boca Raton, and Las Vegas metropolitan areas are the most dangerous places for vehicle-related hyperthermia. We conclude by discussing several recommendations with public health policy implications. 相似文献
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Peter Hovingh 《Journal of Paleolimnology》1993,9(1):41-54
The artesian springs of Tule Valley are similar to those of adjacent Snake Valley and Fish Springs Flat based on conductivity and temperature. All three valleys support Ranidae amphibians and the leechErpobdella punctata. The artesian springs in Snake Valley and Fish Springs Flat contain six and two species of fish and contained up to 18 and 12 species of mollusk respectively, whereas Tule Valley artesian springs contain neither fish nor mollusks. The leechesHelobdella stagnalis, Glossiphonia complanata, andHaemopis grandis were found in Snake Valley whereasHelobdella triserialis, Theromyzon rude, andHaemopis marmorata were found in Tule Valley. These springs which were covered by Lake Bonneville to a depth of several hundred meters, 16 000 BP., became isolated after the paleolake desiccated 13 000 years BP. The marsh snailCatinella is found above the paleolake level in Snake and Tule Valley and has not penetrated to the valley floor habitats once covered by the paleolake, whereas another marsh snailOxyloma has penetrated into these habitats in Snake Valley. The leech and molluscan distributions in Tule, Snake and Fish Springs Valleys suggest that the paleolake did not allow for much movement among the valleys, and successful passive aerial transport has not occurred after the paleolake desiccation 13 000 years BP. Paleozoological models are proposed to explain the presence and absence of these species in Tule Valley. Both lateral movement (along paleolake shorelines) and vertical movement (to new habitats formed after the desiccation of the paleolake) by amphibians, mollusks and leeches is restricted in large terminal lakes and is species dependent in both spatial and temporal scales of the hydrological cycle. 相似文献
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陕西五里铺黄土微量元素组成与全新世气候不稳定性研究 总被引：22，自引：8，他引：14
通过对岐山黄土剖面Pb、Cu、Zn、Cd、Mn元素含量、磁化率及粒度的研究表明,这些元素含量变化实质是气候变化的直接结果,其含量高指示风化成壤作用强烈的湿润环境,含量低指示寒冷的干旱环境。揭示出黄土高原南部全新世气候在总体温暖的情况下有明显波动变化,在5000~6000 a BP出现一次明显气候干旱期,使全新世"大暖期"分裂形成两个主要的成壤期S01和S02。在S01、S02成壤时期仍存在次一级的气候变化事件。全新世时期该地区经历了黄土沉积(Lt)→古土壤发育(S02)→黄土覆盖(L02)→土壤再度发育(S01)→黄土堆积及现代表土(L10)的发展演化阶段。 相似文献
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China's rapid growth and structural change since the reform in the late 1970s have generated many intriguing issues for scholarly research. This paper notices the drastic rise of China in foreign investment, export, and ICT production. Through a comprehensive review of the literature on globalization, industrial restructuring and regional development, this paper holds that the research on China is embedded in China's reform process, as well as theoretical development in economic geography. It highlights the important role of institutions and global-local interactions in industrial and regional development. 相似文献
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lintroductionPopulahondistribuhonisaSynthesizedindicatorofthephysical,socialandeconomicsituation,whichalsoexertSsiofcantimpactonsocio-economicdotlopment.AnhonalPOpulationdistributionhasbecomeamajorgoalofPOpulahonanddevelopmentregulationin~deVelopingcountriesinland1983).ChinaisavaStandPOpulouscountly.ItSvariousregionshaVedifferentphysical,economicandhistoricalcondihonsaswellascurrentPOpulationchacteristjcs.Populationdistribuhonvallesfromregiontoregion.RahonalPOpulahondistribuhonisanimPO… 相似文献