63 research outputs found
Management Implications of Molt Migration by the Atlantic Flyway Resident Population of Canada Geese, Branta canadensis
We used satellite-tracked transmitters in 2001 and 2003 to document the timing, location, and extent of molt migrations by female Canada Geese (Branta canadensis) affiliated with the Atlantic Flyway Resident Population (AFRP) of Canada Geese that breed in the temperate region of eastern North America. Twenty-seven adult females were captured during the nesting period in late May and fitted with a satellite transmitter mounted either on a plastic neck collar or backpack harness. Nests of 24 birds were destroyed late in incubation to prevent renesting and ensure nest failure; three females did not have nests. Twelve of the 27 birds (44%) made a northward migration to molt in northern Quebec, Canada: seven to the eastern coast of Hudson Bay (58°12'N, 76°60'W), three to lowland areas east of James Bay (53°30'N, 79°02'W), and two to interior locations south of Ungava Bay (55°54'N, 68°24'W). Molt migrants were present in northern Quebec from June to September, a period that coincides with breeding ground aerial surveys and banding operations conducted for Atlantic Population (AP) Canada Geese that breed in this same region of northern Quebec. With >1 million AFRP geese estimated in the Atlantic Flyway, the potential exists for substantial numbers of yearling, sub-adult, and nest-failed or non-breeding adults to molt migrate to northern breeding areas and bias efforts to survey and mark AP geese. Within AFRP breeding areas, many local flocks have reached nuisance levels. We hypothesized that by inducing molt migration in breeding adults, through destruction of nests late in incubation, we would lessen recruitment, reduce numbers of summer resident adults with young, and increase adult mortality from hunting. However, molt migration behavior was not uniform throughout our study area. Molt migrants were from rural areas in New York, Pennsylvania, and Vermont, whereas marked birds that did not make molt migrations were from more coastal regions of the flyway. The 14 birds that did not make a molt migration remained within 60 km of their banding site. A genetic comparison of these two groups revealed no detectable differences. We conclude that failure to undergo a molt migration is likely attributed to the historical origin of captive-reared birds of mixed subspecies that comprise AFRP flocks in the eastern regions of the flyway and the availability of quality local habitat, distinct from brood-rearing areas, for molting
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Exploring racial disparity in obesity: A mediation analysis considering geo-coded environmental factors.
Research shows aconsistent racial disparity in obesity between white and black adults in the United States. Accounting for the disparity is a challenge given the variety of the contributing factors, the nature of the association, and the multilevel relationships among the factors. We used the multivariable mediation analysis (MMA) method to explore the racial disparity in obesity considering not only the individual behavior but also geospatially derived environmental risk factors. Results from generalized linear models (GLM) were compared with those from multiple additive regression trees (MART) which allow for hierarchical data structure, and fitting of nonlinear and complex interactive relationships. As results, both individual and geographically defined factors contributed to the racial disparity in obesity. MART performed better than GLM models in that MART explained a larger proportion of the racial disparity in obesity. However, there remained disparities that cannot be explained by factors collected in this study
Heavy episodic drinking on college campuses: Does changing the legal drinking age make a difference
ABSTRACT. Objective: This article extends the compartmental model previously developed by Scribner et al. in the context of college drinking to a mathematical model of the consequences of lowering the legal drinking age. Method: Using data available from 32 U.S. campuses, the analyses separate underage and legal age drinking groups into an eight-compartment model with different alcohol availability (wetness) for the underage and legal age groups. The model evaluates the likelihood that underage students will incorrectly perceive normative drinking levels to be higher than they actually are (i.e., misperception) and adjust their drinking accordingly by varying the interaction between underage students in social and heavy episodic drinking compartments. Results: The results evaluate the total heavy episodic drinker population and its dependence on the difference in misperception, as well as its dependence on underage wetness, legal age wetness, and drinking age. Conclusions: Results suggest that an unrealistically extreme combination of high wetness and low enforcement would be needed for the policies related to lowering the drinking age to be effective. (J. Stud. Alcohol Drugs, 72
Absence of Adolescent Obesity in Grenada: Is This a Generational Effect?
Background: Low- and middle-income countries are affected disproportionately by the ongoing global obesity pandemic. Representing a middle income country, the high prevalence of obesity among Grenadian adults as compared to US adults is expected as part of global obesity trends. The objective of this study was to determine if Grenadian adolescents have a higher prevalence of overweight compared to their US counterparts, and if a disparity exists between urban and rural adolescents.Methods: Using a subcohort of participants in the Grenadian Nutrition Student Survey, diet quality and anthropometric measures were collected from 55% of the classrooms of first year secondary students in Grenada (n = 639). Rural or urban designations were given to each school. Body Mass Index (BMI) was calculated and categorized as overweight or obese for each student following CDC classification cutoffs. A standardized BMI (BMIz) was calculated for each school. Sex-specific BMI and overall BMIz were compared to a 1980s US cohort. Multilevel models, overall and stratified by sex, of students nested within schools were conducted to determine if BMIz differed by rural or urban locality, gender, and diet quality.Results: The mean age of this cohort was 12.7 (SD = 0.8) years with 83.8% of the cohort identifying as Afro-Caribbean. Females had nearly twice the prevalence of overweight when compared to males (22.7 vs. 12.2%) but a similar prevalence of obesity (8.2 vs. 6.8%). Grenadian adolescents had lower prevalence of overweight (females: 22.7 vs. 44.7%; males: 12.2 vs. 38.8%, respectively) as compared to US counterparts. Eating a traditional diet was negatively associated with BMIz score among females (ÎČ^ = â0.395; SE = 0.123) in a stratified, multilevel analysis. BMIz scores did not differ significantly by rural or urban school designation.Conclusions: Among Grenadian adolescents, this study identified a lower overweight prevalence compared to US counterparts and no difference in overweight prevalence by urban or rural location. We hypothesize that the late introduction of processed foods to Grenada protected this cohort from obesogenic promoters due to a lack of fetal overnutrition. However, further research in subsequent birth cohorts is needed to determine if adolescent obesity will increase due to a generational effect
Does Time Since Immigration Modify Neighborhood Deprivation Gradients in Preterm Birth? A Multilevel Analysis
Immigrantsâ health is jointly influenced by their pre- and post-migration exposures, but how these two influences operate with increasing duration of residence has not been well-researched. We aimed to examine how the influence of maternal country of birth and neighborhood deprivation effects, if any, change over time since migration and how neighborhood effects among immigrants compare with those observed in the Canadian-born population. Birth data from Ontario hospital records (2002â2007) were linked with an official Canadian immigration database (1985â2000). The outcome measure was preterm birth. Neighborhoods were ranked according to a neighborhood deprivation index developed for Canadian urban areas and collapsed into tertiles of approximately equal size. Time since immigration was measured from the date of arrival to Canada to the date of delivery, ranging from 1 to 22Â years. We used cross-classified random effect models to simultaneously account for the membership of births (Nâ=â83,233) to urban neighborhoods (Nâ=â1,801) and maternal countries of birth (Nâ=â168). There were no differences in preterm birth between neighborhood deprivation tertiles among immigrants with less than 15Â years of residence. Among immigrants with 15Â years of stay or more, the adjusted absolute risk difference (ARD%, 95% confidence interval) between high-deprived (tertile 3) and low-deprived (tertile 1) neighborhoods was 1.86 (0.68, 2.98), while the ARD% observed among the Canadian-born (Nâ=â314,237) was 1.34 (1.11, 1.57). Time since migration modifies the neighborhood deprivation gradient in preterm birth among immigrants living in Ontario cities. Immigrants reached the level of inequalities in preterm birth observed at the neighborhood level among the Canadian-born after 14Â years of stay, but neighborhoods did not influence preterm birth among more recent immigrants, for whom the maternal country of birth was more predictive of preterm birth
Neighbourhood alcohol availability and gonorrhea rates: impact of social capital
Social capital and income inequality have been proposed as important mediators of the relation between the
material environment and health outcomes. We determined whether indicators of social capital are (i) associated with
neighbourhood gonorrhea rates, and (ii) mediate the relation between alcohol outlet density and gonorrhea rate.
Longitudinal analyses of age- and sex-adjusted gonorrhea cases reported from 1990 to 1996 in the 445 census tracts
affected by the 1992 civil unrest in Los Angeles, California was conducted. The role of alcohol outlets was assessed
both as tracts with surrendered off-sale outlets due to the civil unrest and annual off-sale alcohol outlet density rates.
Tract level voting rates were used as one indicator of social capital, while neighbourhood structure conducive to social
organization was used as another. Neighbourhoods with greater voting over time and greater endogenous social organization
experienced 1.9 and 67.2 fewer gonorrhea cases per 100,000. Results also reveal a partial mediating role of
social capital on the relationship between alcohol outlet density and gonorrhea rate. The alcohol environment may have
a direct or partially mediated role in infectious disease outcomes such as gonorrhea. Our findings support the importance
of continuing controls and limits on off-premise alcohol outlet density, as a potential means of reducing gonorrhea
rates and increasing social capital
Alcohol outlet density and alcohol consumption in Los Angeles county and southern Louisiana
The objective of this study was to assess the relationship between alcohol availability, as measured by the density
of off-premise alcohol outlets, and alcohol consumption in Los Angeles county and southern Louisiana, USA.
Consumption information was collected through a telephone survey of 2,881 households in Los Angeles county and
pre-Katrina southern Louisiana, nested within 220 census tracts. Respondentsâ addresses were geo-coded and both
neighbourhood (census tracts and buffers of varying sizes) and individual (network distance to the closest alcohol outlet)
estimates of off-sale alcohol outlet density were computed. Alcohol outlet density was not associated with the percentage
of people who were drinkers in either site. Alcohol outlet density was associated with the quantity of consumption
among drinkers in Louisiana but not in Los Angeles. Outlet density within a one-mile buffer of the respondentâs
home was more strongly associated with alcohol consumption than outlet density in the respondentâs census
tract. The conclusion is that the relationship between neighbourhood alcohol outlet density and alcohol consumption
is complex and may vary due to differences in neighbourhood design and travel patterns
Fast Food, Race/Ethnicity, and Income: A Geographic Analysis
Background: Environmental factors may contribute to the increasing prevalence of obesity, especially in black and low-income populations. In this paper, the geographic distribution of fast food restaurants is examined relative to neighborhood sociodemographics. Methods: Using geographic information system software, all fast-food restaurants within the city limits of New Orleans, Louisiana, in 2001 were mapped. Buffers around census tracts were generated to simulate 1-mile and 0.5-mile âshopping areasâ around and including each tract, and fast food restaurant density (number of restaurants per square mile) was calculated for each area. Using multiple regression, the geographic association between fast food restaurant density and black and low-income neighborhoods was assessed, while controlling for environmental confounders that might also influence the placement of restaurants (commercial activity, presence of major highways, and median home values). Results: In 156 census tracts, a total of 155 fast food restaurants were identified. In the regression analysis that included the environmental confounders, fast-food restaurant density in shopping areas with 1-mile buffers was independently correlated with median household income and percent of black residents in the census tract. Similar results were found for shopping areas with 0.5-mile buffers. Predominantly black neighborhoods have 2.4 fast-food restaurants per square mile compared to 1.5 restaurants in predominantly white neighborhoods. Conclusions: The link between fast food restaurants and black and low-income neighborhoods may contribute to the understanding of environmental causes of the obesity epidemic in these populations
Neighborhood Physical Conditions and Health
Objectives. We explored the relationship between boarded-up housing and rates of gonorrhea and premature mortality. Methods. In this ecological study of 107 US cities, we developed several models predicting rates of gonorrhea and premature death before age 65 from all causes and from specific causes. We controlled for race, poverty, education, population change, and health insurance coverage. Results. Boarded-up housing remained a predictor of gonorrhea rates, all-cause premature mortality, and premature mortality due to malignant neoplasms, diabetes, homicide, and suicide after control for sociodemographic factors. Conclusions. Boarded-up housing may be related to mortality risk because of its potential adverse impact on social relationships and opportunities to engage in healthful behaviors. Neighborhood physical conditions deserve further consideration as a potential global factor influencing health and well-being
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Neighborhood Physical Conditions and Health
Objectives. We explored the relationship between boarded-up housing and rates of gonorrhea and premature mortality.Methods. In this ecological study of 107 US cities, we developed several models predicting rates of gonorrhea and premature death before age 65 from all causes and from specific causes. We controlled for race, poverty, education, population change, and health insurance coverage.Results. Boarded-up housing remained a predictor of gonorrhea rates, all-cause premature mortality, and premature mortality due to malignant neoplasms, diabetes, homicide, and suicide after control for sociodemographic factors.Conclusions. Boarded-up housing may be related to mortality risk because of its potential adverse impact on social relationships and opportunities to engage in healthful behaviors. Neighborhood physical conditions deserve further consideration as a potential global factor influencing health and well-being
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