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Epidemiology studies relying on one address to assign exposures over time share common methodological limitations in failing to account for mobility that may introduce potential exposure misclassification. Using Texas birth certificate and cancer registry data, we identified predictors of residential mobility among mothers of children diagnosed with early childhood leukemia in Texas from 1995 to 2011. We used U.S. Environmental Protection Agency (EPA) National Air Toxics Assessment data to estimate residential levels of benzene and 1,3-butadiene based on addresses at birth and diagnosis and applied mixed-effects ordinal logistic regression models to evaluate differences in exposure classification between the two time periods. In total, 55% of children moved from time of birth to diagnosis, although they generally did not move far (median distance moved was 8 km). Predictors of mobility, at delivery, included younger age, being unmarried and living in neighborhoods with high benzene levels, and, at diagnosis, increasing child's age and living in neighborhoods with low poverty rates. We observed that the odds of being assigned to a higher exposure quartile at diagnosis relative to the time of birth decreased by 31% for 1,3-butadiene (OR = 0.69, 95% CI 0.59-0.82) and by 12% for benzene (OR = 0.88, 95% CI 0.75, 1.05).

"In this paper, [the authors] examine the effects of likely demographic changes on medical spending for the elderly. Standard forecasts highlight the potential for greater life expectancy to increase costs: medical costs generally increase with age, and greater life expectancy means that more of the elderly will be in the older age groups. Two factors work in the other direction, however. First, increases in life expectancy mean that a smaller share of the elderly will be in the last year of life, when medical costs generally are very high.... Second, disability rates among the surviving population have been declining in recent years by 0.5 to 1.5 percent annually.... Thus, changes in disability and mortality should, on net, reduce average medical spending on the elderly. However, these effects are not as large as the projected increase in medical spending stemming from increases in overall medical costs.", (excerpt)

"This paper employs a household approach to elderly migration analyses and compares it with the traditional individual approach. The first part of the paper develops some concepts about household mobility and relates them to individual mobility. It then compares the two mobility measurements in a case study using the Public Use Microdata Sample (PUMS) from the 1990 [U.S.] Census. The results show that the mean household size for the elderly moving together tends to be smaller than that for elderly stayers. It also demonstrates the utility of the household approach on profiling elderly movers' living arrangement choices. The second part of the paper calibrates a set of discrete choice models based on the household and individual approaches.", (excerpt)

"The relationship between migration and unemployment duration is examined. Standard job search predictors of spell length (replacement income, labor force experience, personal characteristics and economic conditions) are included as control variables alongside measures of migration in a Weibull hazard model. The model is estimated using data from the [U.S.] National Longitudinal Survey of Youth. Young adults who migrated while unemployed had longer durations of unemployment than those who did not migrate. The rate at which they found jobs was also linked to how long they had been unemployed, to being laid off, being African American, to going to college, having a mortgage and to national unemployment conditions.", (excerpt)

"This study investigates the impact of climate on [U.S.] metropolitan elderly migration rates. Factor analysis is used to identify six factors within a set of forty climatic variables. These six factors, along with eleven nonclimatic variables, are used to predict elderly in- and outmigration rates. Metropolitan areas with mild winters and low average incomes are attractive to elderly inmigrants, while those with high rents and clear, dry summers are likely to lose older residents through outmigration. These findings are consistent with the life course model of mobility, and with the distinction between conservative and innovating migrants.", (excerpt)

"The 1980 U.S. Census revealed a marked acceleration in the suburbanization of blacks during the 1970s. This paper provides a preliminary answer to whether that acceleration continued in the 1980s by examining the 1985 American Housing Survey (National and Metropolitan Samples). These data sets permit racial and socioeconomic status comparisons in overall suburbanization level and in the propensity of recent movers to choose suburban destinations. Blacks continue to exhibit low levels of suburbanization relative to whites, and only a small percentage of blacks originating in central cities move to suburban areas. However, once in the suburbs, blacks tend to remain there at the same rate as whites. Intrametropolitan racial segregation remains strong, although it shows signs of decreasing." This paper was originally presented at the 1990 Annual Meeting of the Population Association of America (see Population Index, Vol. 56, No. 3, Fall 1990, p. 431)., (excerpt)

"This paper steps back from the current political debate [in the United States] over the social security trust fund and examines the more general question of how serious a macroeconomic problem aging is and how policy should respond to it. We focus primarily on issues relating to saving and capital accumulation. We do not consider the broader question of whether the current U.S. national saving rate is too high or too low, but focus on the effect of demographic changes on the optimal level of national saving. In addition, we consider the effects of demographic change on productivity growth and the optimal timing of tax collections. Our general conclusion is that demographic changes will improve American standards of living in the near future, but lower them slightly over the very long term. Other things being equal, the optimal policy response to recent and anticipated demographic changes is almost certainly a reduction rather than an increase in the national saving rate.", (excerpt)

In the context of todays ageing population, this paper uses the connectedness network model proposed by Diebold and Yilmaz in 2014 to analyse the directionality and degree of interaction between the population ageing index, life expectancy, per capita gross domestic product, and per capita health expenditure from a systematic perspective for China; then, these results from China are compared with the United States. A number of new findings can be identified, as follows: (1) for China and the United States, economic growth may promote the growth of health expenditure and increased life expectancy may cause an increase in the ageing population; (2) China's population age structure has already led to some constraints on economic growth, whereas the United StatesUS's population age structure has had a weak impact on its economic growth; and (3) the ageing population structure for China has a net impact on per capita health expenditure, whereas no such net directional impact was found in the United States. These findings support the idea that policy synergies should be strengthened in the economic, social, and health fields in order to promote both the quality of life of the ageing population and the sustainable development of the economy., (© 2019 John Wiley & Sons, Ltd.)

The present paper provides a meta-study of security and defence foresight documents by the Atlantic Alliance, European Union and various official bodies linked to the Defence Ministries of Canada, France, Germany, Italy, Spain, the United Kingdom and United States. It focuses on the political and social trends impacting on defence and military issues. In global terms, the following can be discerned: rivalry among major powers, with armed conflict between some not ruled out entirely; armed non-state actors strengthened by new technologies; global competition for natural resources; extensive demographic imbalances and migration flows; global risks associated with fragile states. In terms of European internal policy, the following trends are identified: population ageing and the challenges associated with immigrant integration; empowerment of interest-based and identity networks. The paper begins by familiarising readers with the characteristics of foresight documents and the methodologies used in their preparation. [ABSTRACT FROM AUTHOR]

With the accelerating pace of global change, it is imperative that we obtain rapid inventories of the status and distribution of wildlife for ecological inferences and conservation planning. To address this challenge, we launched the SNAPSHOT USA project, a collaborative survey of terrestrial wildlife populations using camera traps across the United States. For our first annual survey, we compiled data across all 50 states during a 14‐week period (17 August–24 November of 2019). We sampled wildlife at 1,509 camera trap sites from 110 camera trap arrays covering 12 different ecoregions across four development zones. This effort resulted in 166,036 unique detections of 83 species of mammals and 17 species of birds. All images were processed through the Smithsonian's eMammal camera trap data repository and included an expert review phase to ensure taxonomic accuracy of data, resulting in each picture being reviewed at least twice. The results represent a timely and standardized camera trap survey of the United States. All of the 2019 survey data are made available herein. We are currently repeating surveys in fall 2020, opening up the opportunity to other institutions and cooperators to expand coverage of all the urban–wild gradients and ecophysiographic regions of the country. Future data will be available as the database is updated at eMammal.si.edu/snapshot‐usa, as will future data paper submissions. These data will be useful for local and macroecological research including the examination of community assembly, effects of environmental and anthropogenic landscape variables, effects of fragmentation and extinction debt dynamics, as well as species‐specific population dynamics and conservation action plans. There are no copyright restrictions; please cite this paper when using the data for publication. [ABSTRACT FROM AUTHOR]

An improved understanding of reclassification as a sociodemographic component of urban growth is important for urban planning and sustainable development. However, empirical assessments of the effect of reclassification on urban population dynamics are lacking, especially in countries in the later stage of the urban transition. Using recently available data on spatial reclassification of rural and urban land areas and population, and adopting multiregional demographic methods, we explicitly examine the effects of reclassification, natural growth and rural–urban migration on urban growth in the United States for the intercensal periods of 1990–2000 and 2000–2010. Results suggest that reclassification played a significant role in U.S. urban population change but its magnitude depends on assumptions about the timing of reclassification. The net effect of reclassification on urban change is the largest when reclassification is assumed to occur at the end, and the smallest when assumed to occur at the beginning, of the decennial census periods. While the impact of natural growth on U.S. urban population change is relatively stable, there is significant uncertainty in the effects of reclassification and rural–urban migration. Additionally, international migration is a key source of urban growth in the United States. We find that the places reclassified from rural to urban or from urban to rural experienced the largest changes in population sizes and age composition. [ABSTRACT FROM AUTHOR]

Between 1950 and 1990, the aggregate population of central cities in the United States declined by 17 percent despite population growth of 72 percent in metropolitan areas as a whole. This paper assesses the extent to which the construction of new limited access highways has contributed to central city population decline. Using planned portions of the interstate highway system as a source of exogenous variation, empirical estimates indicate that one new highway passing through a central city reduces its population by about 18 percent. Estimates imply that aggregate central city population would have grown by about 8 percent had the interstate highway system not been built. [ABSTRACT FROM AUTHOR]

While migrants are widely believed to be positively selected on health, there has been very little empirical exploration of the actual health differential between migrants and non-migrants. This paper explored: 1) the extent of health selection by comparing US immigrants from 19 sending countries to their non-migrating counterparts still residing in the countries of origin; 2) country-level correlates of health selection; and 3) whether country-level health selection accounted for differences in self-rated health between immigrants and US-born Whites. We combined nationally-representative international data with data from US immigrants from the 2003-2007 Current Population Survey. The health selectivity measure was the Net Difference Index (NDI), which compares the distribution of self-rated health between migrants and non-migrants. We calculated Spearman correlation and bivariate regression coefficients between the NDI and economic, health, distance, and migration characteristics of the sending countries. We used generalized estimating equation models to examine the association between country-level health selection and immigrants' current self-rated health. We found immigrants from South America to show the most positive health selection. Health selection was significantly correlated with visa mode of entry, where family networks decrease, but work-related networks increase health selection. There was little evidence that country-level health selection explained differences in the self-rated health of US immigrants relative to US-born Whites. Our findings do not support the idea that country-level health selection underlies the "healthy immigrant effect"., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

In this paper, an entropy-based method is proposed to forecast the demographical changes of countries. We formulate the estimation of future demographical profiles as a constrained optimization problem, anchored on the empirically validated assumption that the entropy of age distribution is increasing in time. The procedure of the proposed method involves three stages, namely: 1) Prediction of the age distribution of a country's population based on an "age-structured population model"; 2) Estimation the age distribution of each individual household size with an entropy-based formulation based on an "individual household size model"; and 3) Estimation the number of each household size based on a "total household size model". The last stage is achieved by projecting the age distribution of the country's population (obtained in stage 1) onto the age distributions of individual household sizes (obtained in stage 2). The effectiveness of the proposed method is demonstrated by feeding real world data, and it is general and versatile enough to be extended to other time dependent demographic variables.

The paper deals with an approach to the description of the age and temporal dynamics of cancer, based on the model describing the dynamics of the age of cancer as a second order phase transition. This approach is widely used for studying physical systems. This model of cancer development as second order phase transitions is in a good agreement with medical statistics. The cancer incidence dynamics is described only with two free parameters, easily verified according to statistics and well interpreted. The applicability of the second order phase transition model for description of a non-physical system defines the universal nature of the processes occurring during phase transitions.

Many theories of geographic mobility assume that the change-of-residence process includes a substantial degree of choice. This paper classifies stated reasons for moving from the 1973 through 1977 Annual Housing Survey into forced, imposed, and preference-dominated categories. About 25 percent of residential mobility and 40 percent of migration occurred under conditions of substantial constraint. Mobility was most often constrained by family dynamics; for migration, occupational relocations frequently imposed the decision-to-move process and determined destinations. The volume of constrained movement indicates that its impact upon individuals, population dynamics, and voluntaristic theories of mobility deserves greater consideration. [ABSTRACT FROM AUTHOR]

In 1971, Schelling introduced a model in which families move if they have too many neighbors of the opposite type. In this paper, we will consider a metapopulation version of the model in which a city is divided into N neighborhoods, each of which has L houses. There are ρNL red families and ρNL blue families for some ρ < 1/2. Families are happy if there are ≤ ρ(c)L families of the opposite type in their neighborhood and unhappy otherwise. Each family moves to each vacant house at rates that depend on their happiness at their current location and that of their destination. Our main result is that if neighborhoods are large, then there are critical values ρ(b) < ρ(d) < ρ(c), so that for ρ < ρ(b), the two types are distributed randomly in equilibrium. When ρ > ρ(b), a new segregated equilibrium appears; for ρ(b) < ρ < ρ(d), there is bistability, but when ρ increases past ρ(d) the random state is no longer stable. When ρ(c) is small enough, the random state will again be the stationary distribution when ρ is close to 1/2. If so, this is preceded by a region of bistability.

Many scholars have offered structural and ideational explanations for the fertility changes occurring around the world. This paper focuses on the influence of developmental idealism-a schema or set of beliefs endorsing development, fertility change, and causal connections between development and fertility. Developmental idealism is argued to be an important force affecting both population policy and the fertility behavior of ordinary people. We present new survey data from ordinary people in six countries-Argentina, China, Egypt, Iran, Nepal, and the United States-about the extent to which developmental idealism is known and believed. We ask individuals if they believe that fertility and development are correlated, that development is a causal force in changing fertility levels, and that fertility declines enhance the standard of living and intergenerational relations. We also ask people about their expectations concerning future trends in fertility in their countries and whether they approve or disapprove of the trends they expect. The data show widespread linkage in the minds of ordinary people between fertility and development. Large fractions of people in these six settings believe that fertility and development are correlated, that development reduces fertility, and that declines in fertility foster development. Many also expect and endorse future declines in fertility.

This paper examines the relationship between migration and marriage by describing how the distributions of marital statuses and assortative mating patterns vary by individual and community experiences of migration. In Mexico, migrants and those living in areas with high levels of out-migration are more likely to be in heterogamous unions. This is because migration increases the relative attractiveness of single return migrants while disproportionately reducing the number of marriageable men in local marriage markets. In the United States, the odds of homogamy are lower for migrants compared with nonmigrants; however, they do not vary depending on the volume of migration in communities. Migrants are more likely than nonmigrants to "marry up" educationally because the relatively small size of this group compels them to expand their pool of potential spouses to include nonmigrants, who tend to be better educated than they are. Among migrants, the odds of marrying outside of one's education group increase the most among the least educated. In Mexican communities with high rates of out-migration, the odds of marrying outside of one's education group are highest among those with the highest level of education. These findings suggest that migration disrupts preferences and opportunities for homogamy by changing social arrangements and normative climates.

According to the Census, racial/ethnic minority populations are growing at such a fast rate that by 2050 more than 50% of the population will belong to a minority group (US Census, 2001). The increasing diversity of the U.S. population is one of the many changes that health-care delivery organizations need to proactively address in order to better serve their community and improve their performance. In this paper, we argue that cultural competency not only is important from a societal perspective, i.e., reducing health disparities, but can also be a strategy for health-care organizations to improve quality, lower cost, and attract customers. We provide detailed recommendations for health-care leaders and managers to adopt in order to successfully serve a diverse patient population.

Mutualism is a biological association for a mutual benefit between two different species. In this paper, firstly, we examine the history and signification of mutualism in relation to symbiosis. Then, we consider the link between concepts and models of mutualism. Models of mutualism depend on different concepts we use: If mutualism is situated at populations' level, it will be expressed by Lotka-Volterra models, concerning exclusively populations' size. If mutualism is considered as a resources' exchange or a biological market increasing the fitness of these organisms, it will be described at an individual level by a cost-benefit model. Our analysis will be limited to the history and epistemology of Lotka-Volterra models and we hypothesize that these models are adapted at first to translate dynamic evolutions of mutualism. They render stability or variations of size and assume that there are clear distinctions and a state of equilibrium between populations of different species. Italian mathematician Vito Volterra demonstrated that biological associations consist in a constant relation between some species. In 1931 and 1935, Volterra described the general form of antagonistic or mutualistic biological associations by the same differential equations. We recognize that these equations have been more used to model competition or prey-predator interactions, but a simple sign change allows describing mutualism. The epistemological problem is the following: Volterra's equations help us to conceptualize a global phenomenon. However, mutualistic interactions may have stronger effects away from equilibrium and these effects may be better understood at individual level. We conclude that, between 1985 and 2000, some researchers carried on working and converting Lotka-Volterra models but this description appeared as insufficient. So, other researchers adopted an economical viewpoint, considering mutualism as a biological market.

Researchers use system dynamics models to capture the mean behavior of groups of indistinguishable population elements (e.g. people) aggregated in stock variables. Yet many modeling problems require capturing the heterogeneity across elements with respect to some attribute(s) (e.g. body weight). This paper presents a new method to connect the micro-level dynamics associated with elements in a population with the macro-level population distribution along an attribute of interest without the need to explicitly model every element. We apply the proposed method to model the distribution of body mass index and its changes over time in a sample population of American women obtained from the U.S. National Health and Nutrition Examination Survey. Comparing the results with those obtained from an individual-based model that captures the same phenomena shows that our proposed method delivers accurate results with less computation than the individual-based model. Copyright © 2014 System Dynamics Society [ABSTRACT FROM AUTHOR]

This paper examines the effect of migration and residential mobility on union dissolution among married and cohabiting couples. Moving is a stressful life event, and a large, multidisciplinary literature has shown that family migration often benefits one partner (usually the man) more than the other Even so, no study to date has examined the possible impact of within-nation geographical mobility on union dissolution. We base our longitudinal analysis on retrospective event-history data from Austria. Our results show that couples who move frequently have a significantly higher risk of union dissolution, and we suggest a variety of mechanisms that may explain this.

This paper reports on residential mobility among patients treated in the Veterans Affairs (VA) health system. We examine mobility in relation to patients' psychiatric disorders, and we assess the impact of mobility on health system geographic accessibility and continuity of care following inpatient discharge. Subjects included 534,002 patients with schizophrenia, bipolar disorder, depression, or with none of these conditions, who received VA services in both FY 01 and FY 02. We report the frequency and predictors of residential moves; we examine distance moved and changes in the proximity of VA providers; and we evaluate associations with timely receipt of outpatient care following inpatient discharges. Approximately 25% of patients with bipolar disorder, 20% with schizophrenia, 16% with depression, and 9% of patients without these conditions completed a residential move in FY 2002. When relocating, patients with schizophrenia and bipolar disorder were more likely to move closer to providers, suggesting greater sensitivity to accessibility barriers.

Although malignant tumors occur at all ages, cancer disproportionately strikes individuals in the age group 65 years and older. Data from the National Cancer Institute Surveillance, Epidemiology, and End Results Program for the most recent five-year period, 1998-2002, reveal that 56% of all newly diagnosed cancer patients and 71% of cancer deaths are in this age group. Median ages of cancer patients at death for the major tumors common to both males and females, all races (lung, colorectal, lymphoma, leukemia, pancreas, stomach, urinary bladder) range from 71 to 77 years. The median age for prostate cancer is 79 years; for ovarian and female breast cancer, the median age is 71 for each tumor. These cancer statistics when cast against the demographic changes occurring in the U.S. population take on urgency and importance for cancer treatment and care in our nation's health care system. The U.S. Census Bureau demographic projections indicate that the number of persons 65 years and older in the United States will double from the current estimate of 35 million persons to a projected 70 million by 2030. Barring any cancer prevention breakthroughs, the expansion of the aged population will likely increase the absolute number of older individuals diagnosed and treated for cancer in coming decades. The United States is not unique as an aging developed industrial nation with a high proportion of the cancer burden in the elderly. Other developed industrial countries have a potentiality for increased cancer incidence and mortality as their populations grow older. This paper, using U.S. Bureau of Census demographic projections and current age standardized death rates per 100,000 population (from Worldwide Cancer Mortality Statistics, Cancer Mondial, WHO, and the International Association for Research on Cancer) compares cancer in the elderly in Italy and the United States. Italy is demographically ranked as the oldest nation in the world. Dimensions of the cancer burden challenge ahead are inferred in the context of two countries with aging populations to underscore the possible increase that demographic factors may have on the magnitude of the cancer problem for older persons in the next 25 years.