Homophily, selection, and choice in segregation models.

Schelling's 1971 work on the dynamics of segregation showed that even a small degree of homophily, the desire to live among like neighbors, can lead to a starkly segregated population. One of the driving factors for this result is that the notion of homophily used is based on group identities that are exogenous and immutable. In contrast, we consider a homophily that arises from the desire to be with neighbors who are behaviorally similar, not necessarily those who have the same group identity. The distinction matters because behaviors are neither exogenous nor immutable but choices that can change as individuals adapt to their neighborhoods. We show that in such an environment, integration rather than segregation is the typical outcome. However, the tendency toward adaptation and integration can be impeded when economic frictions in the form of income inequality and housing cost are present.

Subjective well-being in China's changing society.

There is now recognition that a population's overall level of well-being is defined not just by income and wealth. Where we live and who we interact with are likely to be equally important in our overall levels of satisfaction with our lives. This thinking has stimulated studies of subjective well-being, or happiness, at both national and local scales. These studies suggest that where you live does matter, although it is health and family status that have the most direct effects on well-being. In this study, we use a detailed dataset on well-being from the China Household Finance Survey to reexamine well-being across China, where profound socioeconomic changes are taking place. The study controls for self-reported health and examines subjective well-being across extensive and varied Chinese urban and rural environments. We find that the earlier pessimism about China's well-being, which emphasized declining happiness, may be misplaced. We make two contributions: first, we show a rising level of subjective well-being, and second, we show that there is a narrowing gap in well-being across different social indicators. Methodologically, we bring in the perspectives of both social capital and geographic context.

Segregation through the multiscalar lens.

We introduce a mathematical framework that allows one to carry out multiscalar and multigroup spatial exploratory analysis across urban regions. By producing coefficients that integrate information across all scales and that are normalized with respect to theoretical maximally segregated configurations, this framework provides a practical and powerful tool for the comparative empirical analysis of urban segregation. We illustrate our method with a study of ethnic mixing in the Los Angeles metropolitan area.

Prospect theory and the decision to move or stay.

Migration has always involved stress and risk. More risk-averse households are less likely to move, while less risk-averse households will seek out opportunities and migrate. We investigate how the theoretical contributions of prospect theory, and specifically the endowment effect, can provide new understanding about decisions whether to migrate or not. We test the hypothesis that risk aversion extends the length of stay in the dwelling and, by extension, in the local labor and housing markets. How long people remain in place is a function, we hypothesize, of their independently self-assessed propensity to take risks, after controlling for a range of demographic and socioeconomic characteristics. We use the theoretical insights of prospect theory and the endowment effect (the notion of the "use value" differing from the "exchange value") to explain the likelihood of staying after controlling for life-course events. The results confirm the explanatory power of self-assessed risk in the decision to migrate or stay and, equally important, confirm the role of the endowment effect.

Examining the life course sequence of intending to move and moving.

There is now a substantial body of research which examines the process of making decisions about moving. The questions of interest in that work and in this study using US data are, first, how do life course changes get translated into intentions to move, and second, to what extent are intentions realized or unrealized. This study extends previous work by considering a longer interval in the planning process, and by examining how life cycle changes create intentions, which in turn are translated, or not, into actual moves. We study the antecedents of the expressed intention to move and the outcomes which follow the expressed intention to move. We test the process of forming intentions and moving in the context of life course events and changes. We find that the subset of variables which create the intention to move vary subtly from the variables which create moves, though the triggering effects of family composition change are critical dimensions of both creating intentions and fulfilling those intentions by moving.

Place Attachment and Aging in Place: Preferences and Disruptions.

This paper examines the links between place attachment and older persons' preferences to age in place, and factors that disrupt these preferences. We use data from the 2001-2021 Household, Income and Labour Dynamics in Australia Survey and panel-data modelling to confirm strong associations between several place attachment dimensions and aging-in-place preferences. Strong ties to children, strong social capital, residence in social housing, homeownership status, housing wealth, and home and neighborhood satisfaction are all positively linked to a stronger preference to age in place. Our findings reveal important differences between older homeowners and older non-owners. For owners, closeness to children is a strong predictor of aging-in-place preferences, although mortgage debt can trigger involuntary moves. For non-owners, tenure security achieved through longer durations at one's address of residence is linked to stronger aging-in-place preferences. However, private renters are more often exposed to involuntary moves. We discuss the policy implications of these disruptions.

What Affects Perceived Health Risk Attitude During the Pandemic: Evidence From Migration and Dining Behavior in China.

The COVID-19 pandemic changed behaviors, at least temporarily, and possibly more permanently, with implications for both work and leisure activities. Some of those behavioral changes, such as dining in restaurants, have significant ripple effects on businesses and employment. We investigate the response to health risks in China with a study of decisions about eating out during the pandemic. We find that compared to a traditional measure of financial risk attitude, dining out behavior better captures individuals' attitude toward the health risk posed by the pandemic and is more significant in predicting their expected total consumption during the recovery phase of the pandemic. In addition, we find that the effect of domestic in-migration is positive with respect to dining out, a signifier of confidence in the government response to the safety of internal flows. In contrast, international migration and port city of entry status are strongly negative with respect to dining out. The risk from the virus is perceived to be much stronger in such contexts. From a policy perspective establishing border controls was critical in re-creating a robust economy. Additional city and household level characteristics that affect dining-out behavior are also identified.

Residential mobility and mental health.

We examine the extent to which residential relocation within and between tenure types is associated with changes in mental health. We focus on four types of housing transition - rent-to-own, own-to-rent, own-to-own, and rent-to-rent - using Australian and UK panel data sets from 2001 to 2017. In both countries, transitions into homeownership and moves away from the mortgaged edges toward the unburdened mainstream of outright ownership are positively associated with mental health. On the other hand, shifts by mortgagors towards more precarious positions on the edges of ownership precipitate dips in mental health when there is exposure to high levels of payment and investment risks. Clearly, residential moves can both alleviate and introduce different kinds of risks that affect affordability. Moreover, tenure transitions have impacts on mental health beyond the impacts of payment and investment risks. However, we observe some cross-national differences in findings. In Australia, loss of homeownership has a negative impact on mental health that outweighs the mental health impacts of attaining ownership. In the UK, these findings are reversed. Acute housing affordability problems following moves in Australia, but not in the UK, are a significant driver of mental health outcomes. These differences have institutional explanations.

Evaluation of right ventricular diastolic function, systolic function, and circulating galectin-3 concentrations in dogs with pulmonary stenosis.

BACKGROUND: Cardiovascular diseases with increased right ventricular (RV) afterload induce RV diastolic and systolic dysfunction, and myocardial fibrosis in humans. Studies in dogs with pulmonary stenosis (PS) evaluating RV diastolic function and markers of myocardial fibrosis are lacking. HYPOTHESIS/OBJECTIVES: Dogs with PS have echocardiographic evidence of RV diastolic and systolic dysfunction and increased serum concentrations of galectin-3 (Gal-3), a surrogate biomarker for myocardial fibrosis. ANIMALS: Forty client-owned dogs (10 controls, 30 with PS). METHODS: Prospective study. All dogs had systemic blood pressure measurement, serum biochemical analysis, echocardiography, and measurement of serum Gal-3 concentration performed. RESULTS: Variables of RV diastolic function were obtained in 39/40 dogs. Trans-tricuspid flow velocity in early diastole to trans-tricuspid flow velocity in late diastole ratios (RV E/A) were lower (P < .001) in dogs with PS (median, 0.94; range, 0.62-2.04) compared to controls (1.78; 1.17-2.35). Trans-tricuspid flow velocity in early diastole to tricuspid annular myocardial velocity in early diastole ratios (RV E/e') were higher (P < .001) in dogs with PS (11.55; 4.69-28) compared to control (6.21; 5.16-7.21). Variables of RV systolic function were lower in dogs with PS (P = <.001). Serum Gal-3 concentration was higher (P = .002) in dogs with PS (285.1 pg/mL; 94.71-406.97) compared to control dogs (162.83 pg/mL; 52.3-232.82). CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs with PS have RV diastolic and systolic dysfunction, and increased Gal-3 concentrations. These findings suggest the presence of RV myocardial fibrosis in dogs with PS, which could impact clinical management.

Do women delay family formation in expensive housing markets?

BACKGROUND: Recent research by demographers and economists has examined the link between living costs and fertility outcomes. The literature has provided some evidence that high rents, or high housing costs, discourage fertility. OBJECTIVE: I re-examine the hypothesis that delayed fertility (age at first birth) is related to the costs of housing measured either as rents or sales prices. METHODS: I use data from the American Community Survey for 2006-2008 to construct mean age at first birth for women in a sample of 25 US metropolitan areas stratified by rents and sales prices. The sales prices for those metropolitan areas were from the National Association of Realtors. I use models of both aggregate relationships of mean age at first birth and metropolitan housing cost level measures and individual analyses of mean age and measures of ethnicity, education and labor force participation. RESULTS: The effect of being in an expensive housing market is a delay of first births by three to four years, after controlling for education, ethnicity and labor market participation. However, the relatively modest fit of individual models suggest that while the housing market may play a role it is also clear that there is a complex structure to the decision- making around fertility, labor force participation and housing market entry. Overall completed fertility does not appear to be changed.

Utility of cardiac MRI to diagnose myocardial ischemia and fibrosis in dogs with cardiomegaly secondary to myxomatous mitral valve disease.

OBJECTIVE: To assess whether cardiac MRI or various biomarkers can be used to detect myocardial ischemia and fibrosis in dogs with cardiomegaly secondary to myxomatous mitral valve disease (MMVD). ANIMALS: 6 dogs with cardiomegaly secondary to naturally occurring stage B2 MMVD being treated only with pimobendan with or without enalapril and 6 control dogs with no cardiac disease. All dogs were ≥ 5 years old with no systemic illness. PROCEDURES: Serum cardiac troponin I and concentrations were measured, and dogs were anesthetized for cardiac MRI with ECG-triggered acquisition of native T1- and T2-weighted images. Gadolinium contrast was administered to evaluate myocardial perfusion and late gadolinium enhancement (LGE). Mean T1 and T2 values and regions of LGE were measured with dedicated software. Extracellular volume (ECV) was estimated on the basis of Hct and T1 values of myocardium and surrounding blood. Subjective analysis for myocardial perfusion deficits was performed. RESULTS: Dogs with MMVD had significantly (P = .013) higher cardiac troponin I concentrations than control dogs, but galectin-3 concentrations did not differ (P = .08) between groups. Myocardial fibrosis was detected in 4 dogs with MMVD and 3 control dogs; no dogs had obvious myocardial perfusion deficits. Native T1 and T2 values, postcontrast T1 values, and ECV values were not significantly different between groups (all P > .3). CLINICAL RELEVANCE: Results suggest that some dogs with cardiomegaly secondary to MMVD may not have clinically relevant myocardial fibrosis.

Understanding the social context of the Schelling segregation model.

A recent article [Vinkovic D, Kirman A (2006) Proc Natl Acad Sci USA 103:19261-19265] showing that the Schelling model has a physical analogue extends our understanding of the model. However, prior research has already outlined a mathematical basis for the Schelling model and simulations based on it have already enhanced our understanding of the social dynamics that underlie the model, something that the physical analogue does not address. Research in social science has provided a formal basis for the segregative outcomes resulting from the residential selection process and simulations have replicated relevant spatial outcomes under different specifications of the residential dynamics. New and increasingly detailed survey data on preferences demonstrates the embeddedness of the Schelling selection process in the social behaviors of choosing alternative residential compositions. It also demonstrates that, in the multicultural context, seemingly mild preferences for living with similar neighbors carry the potential to be strong determinants for own race selectivity and residential segregation.

A parallel open-label trial to evaluate microbial cellulose wound dressing in the treatment of diabetic foot ulcers.

The purpose of this study was to compare the rate of wound healing in diabetic foot ulcers (DFU) using either a microbial cellulose (MC) wound dressing or Xeroform™ Petrolatum gauze. In a parallel, open-label trial in which the primary outcome was the rate of wound healing and the time to wound closure, 15 ulcers in type II diabetic patients received an MC dressing. Wounds in 19 control patients with type II diabetes were treated with a Xeroform gauze dressing. All wounds were non infected, Wagner stage II or III and received standard care including debridement, non weight bearing limb support and weekly wound evaluation. The mean time to heal in the MC (±SE) treated group was 32 days ± 2.5 and for controls it was 48 days ± 4.7 (P < 0.01). The rate of weekly wound closure (mean ± SE) was 1.7 times faster in the MC-treated group (cellulose treated, -5.04% per week ± 0.38 versus control, -2.93% per week ± 0.19), (P < 0.001). Among covariants tested by univariate regression, only the original wound area correlated with the time to wound closure (P < 0.001). In conclusion, with the provision of current standards of care, the application of an MC dressing to a diabetic ulcer may enhance the rate of wound healing and shorten the time course of epithelisation.

Microbial cellulose wound dressing in the treatment of nonhealing lower extremity ulcers.

Following standard care, nonhealing lower extremity (LE) ulcers were managed with a bacterial cellulose (BC) wound dressing, Dermafill™, (AMD/Ritmed, Tonawanda, NY), derived from Acetobacter xylinum. The time to 75% reduction in wound size was compared in 11 chronic wounds before and after the application of BC. The mean period of observation before the application of BC was 315 days; (95% CI: 239-392 days). With the application of BC to these chronic wounds, the mean time to 75% epithelization was reduced to 81 days (95% CI: 50-111 days) with a median of 79 days. The rate of wound closure with BC was significantly faster than with standard care (P < 0.001). When applied to nonhealing LE ulcers, a BC wound dressing shortens the time to wound closure over standard care.

Microstructural studies of 35 degrees C copper Ni-Ti orthodontic wire and TEM confirmation of low-temperature martensite transformation.

BACKGROUND: Previous temperature-modulated differential scanning calorimetry (TMDSC) study of nickel-titanium orthodontic wires revealed a large exothermic low-temperature peak that was attributed to transformation within martensitic NiTi. PURPOSE: The purpose of this study was to use transmission electron microscopy (TEM) to verify this phase transformation in a clinically popular nickel-titanium wire, identify its mechanism and confirm other phase transformations found by TMDSC, and to provide detailed information about the microstructure of this wire. METHODS: The 35 degrees C Copper nickel-titanium wire (Ormco) with cross-section dimensions of 0.016 in. x 0.022 in. used in the earlier TMDSC investigation was selected. Foils were prepared for TEM analyses by mechanical grinding, polishing, dimpling, ion milling and plasma cleaning. Standard bright-field and dark-field TEM images were obtained, along with convergent-beam electron diffraction patterns. A cryo-stage with the electron microscope (Phillips CM 200) permitted the specimen to be observed at -187, -45, and 50 degrees C, as well as at room temperature. Microstructures were also observed with an optical microscope and a scanning electron microscope. RESULTS: Room temperature microstructures had randomly oriented, elongated grains that were twinned. Electron diffraction patterns confirmed that phase transformations took place over temperature ranges previously found by TMDSC. TEM observations revealed a high dislocation density and fine-scale oxide particles, and that twinning is the mechanism for the low-temperature transformation in martensitic NiTi. CONCLUSIONS: TEM confirmed the low-temperature peak and other phase transformations observed by TMDSC, and revealed that twinning in martensite is the mechanism for the low-temperature peak. The high dislocation density and fine-scale oxide particles in the microstructure are the result of the wire manufacturing process.

The influence of maternal body mass index and physical activity on select cardiovascular risk factors of preadolescent Hispanic children.

BACKGROUND: Maternal obesity and physical inactivity have been identified as correlates of overweight and obesity and physical inactivity in older preadolescents; however, no study has explored this relationship in Hispanic preadolescents. Furthermore, the relation between maternal physical activity (PA) and blood pressure (BP) in Hispanic preadolescents has not been examined. PURPOSE: This study aimed to assess the associations between Hispanic mothers' PA and body mass index (BMI) and their preadolescents' PA, screen time, BP, and BMI. METHODS: Data of 118 mother-child (aged 2-10 years) dyads enrolled in a cross-sectional study of metabolic syndrome in Hispanic preadolescents at a community health center in Johnson City, TN were used. Parent and child questionnaires were used to ascertain mothers' BMI and PA and preadolescents' PA and screen time. Preadolescents' height, weight, and BP were measured. Multiple logistic regression was used to examine the association between child and maternal variables, adjusting for mother's education and the child's sex and age. RESULTS: Pradolescents of obese mothers were more likely than preadolescents of mothers with normal weight to engage in less than three days of at least 60 min of vigorous PA per week (OR: 6.47, 95% CI [1.61-26.0]). Preadolescents whose mothers did not engage in moderate PA were more likely to engage in less than three days of at least 60 min of vigorous PA per week (OR: 2.92, CI [1.18-7.24]); and have elevated BP (OR: 2.50, 95% CI [1.02-4.53]) than preadolescents whose mothers engaged in moderate PA. DISCUSSION: Our results show a negative relationship between maternal obesity and preadolescent PA, and a positive relationship between lower maternal PA and elevated BP and lower PA in Hispanic preadolescents. This suggests that interventions aimed at improving Hispanic preadolescents' PA and BP may use maternal PA and maternal BMI (for preadolescent PA) as a modification strategy to improve health in Hispanic preadolescents.

Histomorphometric analysis of fracture healing cascade in acute osteoporotic vertebral body fractures.

BACKGROUND: While fracture healing has been well characterised in long bones, there is scant data relating to this process in acute vertebral body fractures. AIM: To characterise the histological process of fracture healing in acute osteoporotic vertebral body fractures using qualitative and quantitative bone histomorphometry. SUBJECTS AND METHODS: Transpedicular bone biopsy was performed in patients undergoing percutaneous vertebroplasty. Undecalcified biopsy specimens were prepared from cores of cancellous bone harvested from vertebral bodies with MRI evidence of bone marrow oedema. These were analysed by light microscopy using grid analysis and defined using bone histomorphometry criteria. Normative data obtained from 5 age-matched volunteers without evidence of metabolic bone disease or osteoporosis was used for comparison. RESULTS: Adequate biopsy specimens were obtained in 72 of 90 patients (15 men and 57 women), mean age 75.6 years. All biopsies confirmed severe osteoporosis with reduced cancellous bone volume (mean of 13.5%; P<0.001 compared to controls). The timing of biopsies varied from 1 to 24 weeks (median of 6 weeks) after the fracture event. There were 4 stages of fracture callus healing observed: Stage I in 17 (24%) patients, Stage II in 16 (22%), Stage III in 22 (30%) and Stage IV in 17 (24%). An overlap between the various stages was evident with 55 (76%) patients demonstrating at least 2 or more of the stages of fracture healing in the same biopsy specimen. The time interval since fracture event was the most important predictor of the stage of the fracture callus (R=0.32; P<0.001). CONCLUSION: Our data demonstrates a mixed fracture callus with overlapping of the various stages of fracture healing. This suggests that individual vertebra may be susceptible to multiple fractures over the course of the healing process.