WEATHER,GEOGRAPHY, AND VEHICLE‐RELATED HYPERTHERMIA IN CHILDREN*

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.     

Neighborhood and socioeconomic change in emerging megapolitan nodes: tracking shifting social geographies in three rapidly growing United States metropolitan areas, 1980–2010

This paper investigates the complex demographic and social changes that have occurred in the neighborhoods of fast-growing United States metropolitan areas emerging as nodes in megapolitan regions between 1980 and 2010. A neighborhood typology is created using k-means cluster analysis to examine the demographic and housing characteristics, and geographic distribution, of neighborhoods that have existed in rapidly growing metropolitan areas. A socioeconomic index is created using principal component analysis (PCA) to analyze socioeconomic conditions within neighborhoods. Using data from the metropolitan areas of Las Vegas, Nevada; Austin, Texas; and Raleigh, North Carolina, this study identifies five neighborhood types, each of which has distinctive geographic and socioeconomic trends. The geographic orientation of each metropolitan area within their larger megapolitan region appears to have a role in the geography of neighborhood change. The results are also discussed in relation to human ecology, immigration, and economic restructuring.     

The validity of the monocentric city model in a polycentric age: US metropolitan areas in 1990, 2000 and 2010

In this article, we use local indicators of spatial association (LISA) and other spatial analysis techniques to analyze the distribution of centers with high employment density within metropolitan areas. We examine the 359 metropolitan areas across the United States at three points in time (1990, 2000, and 2010) to provide a spatio-temporal panoramic of urban spatial structure. Our analysis highlights three key findings. (1) The monocentric structure persists in a majority of metropolitan areas: 56.5% in 1990, 64.1% in 2000, and 57.7% in 2010. (2) The pattern of employment centers remains stable for most metropolitan areas: the number of centers remained the same for 74.9% of metropolitan areas between 1990 and 2000 and for 85.2% between 2000 and 2010. (3) Compared with monocentric metropolitan areas, polycentric metros are larger and more dense, with higher per-capita incomes and lower poverty rates.     

MASCULINISM,POWER, AND DISCOURSES OF EXCLUSION IN BRIAN BERRY’S “SCIENTIFIC” GEOGRAPHY

This paper examines the impact of changes in industry mix, changes in technology, differential plant growth, plant entry and plant exit on metropolitan labor productivity growth between 1963 and 1997. Analysis is based upon unpublished plant-level data from the United States Bureau of the Census. We show that manufacturing productivity varies markedly between metropolitan areas in the United States. The most influential components of productivity growth are technological changes within incumbent plants and changes in industry mix. Significant differences in the relative contributions of these components of productivity change exist across metropolitan areas. Regional differences in rates of plant openings and plant closures also exert considerable impact on metropolitan productivity improvement.     

A total water management analysis of the Las Vegas Wash watershed,Nevada

Climate change, land-use change, and population growth are fundamental factors affecting future hydrologic conditions in streams, especially in arid regions with scarce water resources. Located in the arid southwest within the Las Vegas Wash watershed, Las Vegas is one of the fastest growing metropolitan areas of the country. In the past 30?years, because of climate and land-use changes, it has experienced a decrease in clean water supply but an increase in water demand. To alleviate some of these problems, large amounts of water have been pumped into the city from different sources, such as Lake Mead, and the urban wastewater is treated and returned back to the reservoir for water augmentation. However, in the face of continual global climate change and urbanization in the watershed, long-term planning for sustainable water management is critical. This research was designed to provide a comprehensive analysis incorporating hydrologic modeling, population projection, land-use change modeling, and water management policies to examine the total water balance and management options in this arid and rapidly urbanizing watershed under various scenarios of climate regime, population growth, land-use change, and total water management programs for the year 2050.     

ATLANTA IN THE TELECOMMUNICATIONS AGE: THE FIBER-OPTIC INFORMATION NETWORK

This paper addresses the role of the Atlanta metropolitan area as a telecommunications center based on the use of fiber optics. The major focus is on the intrametropolitan layout of this network, including fiber-optic access points, downtown and suburban fiber loops, and the location of data service and teleservice centers. The aim is to identify congruence between high-technology firms and fiber-optic lines that produce clustering within the metropolitan region. Atlanta has a dense fiber-optic infrastructure in place in the CBD-Midtown area and in several corporate clusters in the suburbs. A number of fiber-optic carriers compete in the Atlanta market—including BellSouth, with approximately 400,000 miles of fiber-optic cable—giving Atlanta more miles of optic fiber than any other metropolitan area in the United States. This extensive fiber network bestows fresh advantages to old downtown property and businesses and creates burgeoning opportunities in the suburbs as it literally undergirds the growth of edge cities at such locations as Perimeter Center and Cumberland-Galleria. Long-established Atlanta firms such as Coca-Cola have drawn fiber sites to themselves, whereas sites on fiber-optic loops attract new businesses seeking ready backbone and broadband access to other metropolitan areas in the United States and cities around the globe. This study also focuses on Atlanta's position within the U.S. intermetropolitan telecommunications hierarchy, where the metropolitan area ranks sixth in total number of backbone connections with other U.S. Metropolitan areas. [Key words: Atlanta, fiber optics, telecommunications.]     

THE INTRAMETROPOLITAN LOCATION OF SERVICES IN THE UNITED STATES

In metropolitan areas, firms trade-off land and information costs. Firms that gain the most from access to the knowledge and know-how of other firms in the same sector are willing and able to pay for expensive central city land. We found that legal services, advertising, and accounting and auditing services are the most centralized services in the 74 largest metropolitan areas of the United States. Maps of seven fast-growing business and professional services in Phoenix, Arizona, show that central city services are mainly located in the CBD. Using a logarithmic function, we found that service jobs are more decentralized in the larger metropolitan areas and in metropolitan areas outside the Northeast. Analysis of disaggregate service sectors shows significant intersectoral variation in this relationship.     

The suburbanization of poverty? An alternative perspective

A popular and powerful narrative focuses on a crisis of suburban decline in the United States. However, a consensus regarding the scope and scale of one dimension of suburban decline—poverty—is hindered by the use of contradictory definitions of suburban space. This research presents an alternative approach to measuring suburban poverty that is less computationally intensive yet capable of capturing complex shifts in the spatial distribution of poverty within metropolitan areas. An analysis of the distribution of poverty in the largest 100 metropolitan areas between 1990 and 2007–11 concludes that while poverty is increasing in the low-density suburbs of a handful of large metropolitan areas, the more general trend in most other metropolitan areas is an increase in poverty in moderately dense residential areas. Implicated in these trends are long-term trends in metropolitan area economic growth, a secular decline in inner-ring suburbs, and the impact of gentrification on housing opportunities for at-risk populations in large cities.     

Evolving United States metropolitan land use patterns

We investigate spatial patterns of residential and nonresidential land use for 257 United States metropolitan areas in 1990 and 2000, measured with 14 empirical indices. We find that metropolitan areas became denser during the 1990s but developed in more sprawl-like patterns across all other dimensions, on average. By far, the largest changes in our land use metrics occurred in the realm of employment, which became more prevalent per unit of geographic area, but less spatially concentrated and farther from the historical urban core, on average. Our exploratory factor analyses reveal that four factors summarize land use patterns in both years, and remained relatively stable across the two years: intensity, compactness, mixing, and core-dominance. Mean factor scores vary by metropolitan population, water proximity, type, and Census region. Improved measurement of metropolitan land use patterns can facilitate policy and planning decisions intended to minimize the most egregious aspects of urban sprawl.     

Short-term and diurnal patterns of salt secretion by Tamarix ramosissima and their relationships with climatic factors

Tamarisk (Tamarix spp.) is an invasive shrub or tree species in the United States. Glands within Tamarix leaves secrete salt that may increase surface soil salinity and consequently result in an unviable ecosystem for native riparian tree species. To increase our understanding of the effects of invasive Tamarix on the ecosystem and its native riparian vegetation, we investigated salt secretion of a stand of Tamarix ramosissima in the Las Vegas Wash, Nevada. Short-term and diurnal salt secretion rates were monitored in the stand from September to October 2009. Soil samples were collected beneath the canopy so that water and salinity conditions could be determined. We used weather data from a Las Vegas database in conjunction with soil temperature data collected for this study. The major cation secreted by salt glands was sodium. Diurnal variation in the salt secretion rate had a maximum during the day, suggesting that salt secretion is dependent on salt transportation to leaves. Variations in the salt secretion rates were mostly influenced by solar radiation, suggesting that salt secretion in T. ramosissima would be enhanced by light in natural conditions.     

Changing Patterns of Population Density in the United States

Changing population density is often ignored in studies of population growth and population transfer in the United States. We show that there is a complex relationship between patterns of population growth and density increase by state. The largest gains in density are in the states of the northeastern megalopolis, California, and Florida. Analysis of the 150 counties with the greatest increases in density between 1980 and 1990 shows that they are well distributed across the United States including the larger metropolitan areas of the “Rustbelt.” In general, the most densely populated states and places are becoming more densely populated, a concept we refer to as densification.     

Changing Patterns of Population Density in the United States

Changing population density is often ignored in studies of population growth and population transfer in the United States. We show that there is a complex relationship between patterns of population growth and density increase by state. The largest gains in density are in the states of the northeastern megalopolis, California, and Florida. Analysis of the 150 counties with the greatest increases in density between 1980 and 1990 shows that they are well distributed across the United States including the larger metropolitan areas of the “Rustbelt.” In general, the most densely populated states and places are becoming more densely populated, a concept we refer to as densification.     

The Shape of Mobility: Measuring the Distance Decay Function of Household Mobility

A well-known challenge to studies examining the distance of residential mobility patterns is that the estimates are often constrained to patterns only within a particular metro area or between metro areas. Thus, studies are unable to estimate the entire distance decay functional form. Using a unique data set on the distance of the most recent move for a large sample of households in twenty-three metropolitan areas in the United States over three waves, we flexibly estimate the distance decay function for the entire sample, as well as for a series of subpopulations based on key demographic information.     

FOREIGN DIRECT INVESTMENT IN U.S. METROPOLITAN AREAS, 1979-1983

Ordinary least-squares multiple regression is used to construct a path diagram showing the direct and indirect effects of corporate location factors on the share of foreign direct investment (FDI) in the 44 largest metropolitan areas in the United States during the period 1979-1983. The results show that the metropolitan areas with the most rapid population growth over the period 1970-1980 correspond to the centers with greater shares of FDI. The growth in Fortune measure, an indicator of the market dynamics of the metropolitan areas, has a direct effect on the level of investment. The growth of employment in manufacturing and in finance, insurance, and real estate, used as indexes of labor supply and of producer services, have indirect effects on FDI. The results show that foreign direct investors tend to concentrate in centers offering strong markets and strong bases of producer services, regardless of their regional locations.     

Declining Union Contract Coverage and Increasing Income Inequality in U.S. Metropolitan Areas

We focus on the association between the institutional factor of union contract coverage rates among workers and the variation in income inequality across a set of sixty-four metropolitan areas of the United States for the years 1990, 2000, and 2010. We use market variables of relative skills and relative education and demographic variables of race and gender as controls in our regression models. We also specify a set of models that substitute right-to-work status for union contract coverage rates. Our primary finding is that union contract coverage rates are temporally consistent and significant negative covariates of income inequality, as measured by Gini coefficients, across the metropolitan areas. Further, metropolitan areas in right-to-work states have consistently and significantly higher levels of inequality than expected given the control variable effects. Our interpretation of the primary finding is that issues of labor power and class play a clearly important role in contributing to income inequality in the set of metropolitan areas used in the analysis.     

The economic geography of institutional investment in the United States, 2010

The economic geography of United States’ institutional investments as of December 2010 is presented. With a self-declared value of almost $13 trillion, it is the largest class of equity investors. Included are all investors who file Securities Exchange Commission (SEC) form 13f, meaning they manage at least $100 million. Analysis is undertaken at both the firm and metropolitan levels. The largest firms and targets of investment are determined. Geographic concentrations of both investors and their major stock holdings occur in a small subset (the top 10 largest metropolitan areas). The rates of returns on investments are shown to differ by metropolitan area of investment and by urban rank in the urban hierarchy. Intra-metropolitan investment provides worse rates of returns, countering suggestions of informational advantages for local investment. The network of interurban investments shows a clear hierarchical structure, with New York City being the dominant investment centre.     

IDENTITY AND ASSIMILATION AMONG YOUNG ETHIOPIAN IMMIGRANTS IN METROPOLITAN WASHINGTON*

ABSTRACT. Ethiopians are a recent immigrant group in the United States, having entered the country in significant numbers during the 1980s and 1990s. This preliminary study examines the ethnic and racial identities of children of first‐generation Ethiopian immigrants living in the Washington, D.C. metropolitan area. The results of twenty in‐depth interviews demonstrate that race is a much more fluid and contested form of identification than is ethnicity to the young immigrants, who equate the latter unilaterally with their Ethiopian heritage. Immigrants also adopt different subject identities in various locales, favoring those that are most in accordance with their needs and sense of self.     

NEW APPROACHES TO DELINEATING METROPOLITAN AND NONMETROPOLITAN SETTLEMENT: GEOGRAPHERS DRAWING THE LINE

The federal government's Office of Management and Budget, with staff support from the Census Bureau's Population Division, is responsible for maintaining the statistical standard that provides criteria used to define metropolitan settlement and that delineates individual metropolitan areas for use in federal statistics. Review of the current standard, which dates from 1990, is now under way in conjunction with the 2000 census. Reviews of the emergence of the metropolitan form of settlement in the United States and of previous geospatial units representing metropolitan settlement are provided. A framework of geospatial units to represent the various elements of settlement at the close of the 20th century, including metropolitan and nonmetropolitan forms, is offered. Three papers that provide new approaches to delineating metropolitan and nonmetropolitan settlement in the United States are introduced. [Keywords: metropolitan and nonmetropolitan settlement, geospatial units of analysis, federal government, statistics.]     

CHEMICAL HAZARDS IN URBAN AMERICA

This paper examines the spatial distribution of airborne releases of acutely toxic materials in 3 17 metropolitan areas in the United States. There were 1,362 incidents in urban areas between 1980 and 1989.One-third of the urban areas had no recorded releases during the decade, while 1 I% had at least one per year. Metropolitan areas were classified into high, medium, and low hazard areas based on incident frequency. A discriminant analysis was used to help differentiate these places using measures of risk and mitigation. The analysis correctly classified 81% of the metropolitan areas and found that five variables were the most important indicators of hazard: number of chemical services; number of railroad track miles; number of nondurable agricultural suppliers; population density; and number of railroad yards. Four of these variables stress the importance of risk indicators (industrial infrastructure) within a city that contribute to the potential for disaster. While we can begin to understand the hazards of place, many issues, such as the human consequences of these hazards, the sociospatial inequities in the distribution of risks and mitigation responses, and the scale and complexity of industrial facilities in contributing to the chemical hazardscape, require further exploration.     

新奥尔良飓风灾难与华南沿海台风暴潮

分析了新奥尔良的地理环境,概述了卡特里娜飓风与丽塔飓风及其对新奥尔良的影响.简述了华南沿海的台风暴潮灾害情况,提出了新奥尔良飓风灾难对华南沿海的几点警示:(1)加强提高防御台风暴潮灾害的认识;(2)保护好沿海抗御台风暴潮的"前沿阵地;(3)加强和完善防台风暴潮应急预案;(4)应对台风暴潮要充分考虑全球环境变化.