Rachel S. Gross

Genetic structure of Atlantic sturgeon populations based on mitochondrial DNA control region sequences

Abstract The Atlantic sturgeon Acipenser oxyrinchus oxyrinchus has a latitudinally broad distribution along the east coast of North America, with extant populations occurring from the Saint Lawrence River to rivers in southern Georgia. This species once supported intensive caviar-based fisheries that resulted in overharvest and sharply reduced population abundances; presently, directed commercial fishing for Atlantic sturgeon is banned in U.S. waters. We sequenced a 203-base-pair section of the mitochondrial DNA (mtDNA) control region of 322 Atlantic sturgeon specimens from 11 river systems across their range to elucidate their stock structure. We found a pronounced latitudinal cline in the number of composite mtDNA haplotypes and in haplotypic diversity, which increased from north to south, from previously glaciated and subsequently recolonized systems to the portion of their range unglaciated during the Pleistocene. The observed number of haplotypes per population ranged from 1 haplotype in each of the ...

Population genetics of shortnose sturgeon Acipenser brevirostrum based on mitochondrial DNA control region sequences

Shortnose sturgeon is an anadromous North American acipenserid that since 1973 has been designated as federally endangered in US waters. Historically, shortnose sturgeon occurred in as many as 19 rivers from the St. John River, NB, to the St. Johns River, FL, and these populations ranged in census size from 101 to 104, but little is known of their population structure or levels of gene flow. We used the polymerase chain reaction (PCR) and direct sequence analysis of a 440 bp portion of the mitochondrial DNA (mtDNA) control region to address these issues and to compare haplotype diversity with population size. Twenty‐nine mtDNA nucleotide‐substitution haplotypes were revealed among 275 specimens from 11 rivers and estuaries. Additionally, mtDNA length variation (6 haplotypes) and heteroplasmy (2–5 haplotypes for some individuals) were found. Significant genetic differentiation (P < 0.05) of mtDNA nucleotide‐substitution haplotypes and length‐variant haplotypes was observed among populations from all rivers and estuaries surveyed with the exception of the Delaware River and Chesapeake Bay collections. Significant haplotype differentiation was even observed between samples from two rivers (Kennebec and Androscoggin) within the Kennebec River drainage. The absence of haplotype frequency differences between samples from the Delaware River and Chesapeake Bay reflects a probable current absence of spawning within the Chesapeake Bay system and immigration of fish from the adjoining Delaware River. Haplotypic diversity indices ranged between 0.817 and 0.641; no relationship (P > 0.05) was found between haplotype diversity and census size. Gene flow estimates among populations were often low (< 2.0), but were generally higher at the latitudinal extremes of their distribution. A moderate level of haplotype diversity and a high percentage (37.9%) of haplotypes unique to the northern, once‐glaciated region suggests that northern populations survived the Pleistocene in a northern refugium. Analysis of molecular variance best supported a five‐region hierarchical grouping of populations, but our results indicate that in almost all cases populations of shortnose sturgeon should be managed as separate units.

Food Insecurity and Obesogenic Maternal Infant Feeding Styles and Practices in Low-Income Families

OBJECTIVES: We explored the relationship between household food insecurity and maternal feeding styles, infant feeding practices, and perceptions and attitudes about infant weight in low-income mothers. METHODS: Mothers participating in the Special Supplemental Food Program for Women, Infants, and Children with infants aged between 2 weeks and 6 months were interviewed. By using regression analyses, the following relationships were examined between food insecurity and: (1) controlling feeding styles (restrictive and pressuring); (2) infant feeding practices, including breastfeeding, juice consumption, and adding cereal to the bottle; and (3) perceptions and attitudes about infant weight. Path analysis was used to determine if perceptions and attitudes about infant weight mediated the relationships between food insecurity and controlling feeding styles. RESULTS: The sample included 201 mother–infant pairs, with 35% reporting household food insecurity. Food-insecure mothers were more likely to exhibit restrictive (B [SE]: 0.18 [0.08]; 95% confidence interval [CI]: 0.02–0.34) and pressuring (B [SE]: 0.11 [0.06]; 95% CI: 0.001–0.22) feeding styles compared with food-secure mothers. No associations were found with feeding practices. Concern for their infant becoming overweight in the future was associated with food insecurity (adjusted odds ratio: 2.11 [95% CI: 1.02–4.38]). This concern mediated the relationship between food insecurity and both restrictive (P = .009) and pressuring (P = .01) feeding styles. CONCLUSIONS: Increased concern about future overweight and controlling feeding styles represent potential mechanisms by which food insecurity could be related to obesity. Obesity prevention should aim to decrease food insecurity and to reduce controlling feeding styles in families who remain food insecure.

Screening for Social Determinants of Health Among Children and Families Living in Poverty: A Guide for Clinicians

Approximately 20% of all children in the United States live in poverty, which exists in rural, urban, and suburban areas. Thus, all child health clinicians need to be familiar with the effects of poverty on health and to understand associated, preventable, and modifiable social factors that impact health. Social determinants of health are identifiable root causes of medical problems. For children living in poverty, social determinants of health for which clinicians may play a role include the following: child maltreatment, child care and education, family financial support, physical environment, family social support, intimate partner violence, maternal depression and family mental illness, household substance abuse, firearm exposure, and parental health literacy. Children, particularly those living in poverty, exposed to adverse childhood experiences are susceptible to toxic stress and a variety of child and adult health problems, including developmental delay, asthma and heart disease. Despite the detrimental effects of social determinants on health, few child health clinicians routinely address the unmet social and psychosocial factors impacting children and their families during routine primary care visits. Clinicians need tools to screen for social determinants of health and to be familiar with available local and national resources to address these issues. These guidelines provide an overview of social determinants of health impacting children living in poverty and provide clinicians with practical screening tools and resources.

Phthalates and the diets of US children and adolescents

BACKGROUND Di-2-ethylhexylphthalate (DEHP) is an ester of phthalic acid commonly found in processed foods. DEHP may contribute to obesity and insulin resistance in children and adolescents, yet dietary exposures have been not been studied in this vulnerable subpopulation. OBJECTIVE To assess diet and its relation to urinary phthalates in a nationally representative sample of US children and adolescents. DESIGN Cross-sectional analysis of 24-h dietary recall and urinary phthalate metabolites from 2743 6-19 year olds participating in the 2003-8 National Health and Nutrition Examination Surveys. Regression analyses examined relationships of food consumption with log-transformed metabolite concentrations, examined as low-molecular weight, high molecular weight and di-2-ethylhexylphthalate categories, controlling for urinary creatinine, age group, body mass index category, race/ethnicity, caloric intake and gender. RESULTS We identified a -0.04% (95% CI: -0.08, -0.01) increment in di-2-ethylhexylphthalate metabolite concentration/additional gram fruit consumption, a +0.01% increment/additional calorie dietary intake (95% CI: +0.003, +0.02), and a +0.09% (95% CI: +0.02, +0.17) increment/additional gram meat/poultry/fish consumption. Soy consumption (-0.40% increment/additional gram consumed, 95% CI: -0.66, -0.14) was inversely associated with di-2-ethylhexylphthalate, while poultry (+0.23% increment/additional gram consumed, 95% CI: +0.12, +0.35) was positively associated. Findings were robust to examination of metabolite concentrations per unit body mass index and weight, and inclusion of fasting time. CONCLUSIONS Diet contributes to urinary phthalate concentrations in children and adolescents. Further study is needed to examine the implications of di-2-ethylhexylphthalate exposure, especially earlier in life, when more permanent metabolic changes may occur.

Redesigning Health Care Practices to Address Childhood Poverty

Child poverty in the United States is widespread and has serious negative effects on the health and well-being of children throughout their life course. Child health providers are considering ways to redesign their practices in order to mitigate the negative effects of poverty on children and support the efforts of families to lift themselves out of poverty. To do so, practices need to adopt effective methods to identify poverty-related social determinants of health and provide effective interventions to address them. Identification of needs can be accomplished with a variety of established screening tools. Interventions may include resource directories, best maintained in collaboration with local/regional public health, community, and/or professional organizations; programs embedded in the practice (eg, Reach Out and Read, Healthy Steps for Young Children, Medical-Legal Partnership, Health Leads); and collaboration with home visiting programs. Changes to health care financing are needed to support the delivery of these enhanced services, and active advocacy by child health providers continues to be important in effecting change. We highlight the ongoing work of the Health Care Delivery Subcommittee of the Academic Pediatric Association Task Force on Child Poverty in defining the ways in which child health care practice can be adapted to improve the approach to addressing child poverty.

Maternal Depressive Symptoms and Child Obesity in Low-Income Urban Families

OBJECTIVE To characterize the relationship between maternal depressive symptoms and child weight status, obesity-promoting feeding practices, and activity-related behaviors in low-income urban families. METHODS We conducted a cross-sectional survey of mothers with 5-year-old children receiving pediatric care at a federally qualified community health center. We used regression analyses to examine the relationship between maternal depressive symptoms (trichotomized: none, mild, moderate to severe) and 1) child weight status; 2) obesity-promoting feeding practices, including mealtime practices and feeding styles; and 3) activity-related behaviors, including sleep time, screen time, and outdoor playtime. RESULTS The sample included 401 mother-child pairs (78.3% response rate), with 23.4% of mothers reporting depressive symptoms (15.7% mild, 7.7% moderate to severe). Mothers with moderate to severe depressive symptoms were more likely to have overweight and obese children than mothers without depressive symptoms (adjusted odds ratio 2.62; 95% confidence interval 1.02-6.70). Children of mildly depressed mothers were more likely to consume sweetened drinks and to eat out at restaurants and were less likely to eat breakfast than children of nondepressed mothers. Mothers with depressive symptoms were less likely to set limits, to use food as a reward, to restrict their childs intake, and to model healthy eating than nondepressed mothers. Children with depressed mothers had less sleep and outdoor playtime per day than children of nondepressed mothers. CONCLUSIONS Maternal depressive symptoms are associated with child overweight and obese status and with several obesity-promoting practices. These results support the need for maternal depression screening in pediatric obesity prevention programs. Further research should explore how to incorporate needed mental health support.

Maternal Controlling Feeding Styles During Early Infancy

This study sought to determine the relationship between maternal controlling feeding styles and maternal perception of their infant’s ability to regulate feeding and infant weight. A cross-sectional survey of 208 mothers with infants between 2 weeks and 6 months old was performed in a private pediatric office. The authors assessed the relationship between restrictive and pressuring feeding styles with (a) maternal perception of the infant’s ability to regulate feeding and (b) infant weight (both actual and perceived). Restrictive feeding style was associated with the perception that infants could not recognize their own hunger or satiety and with concern that the infant would become overweight in the future. Pressuring feeding style was associated with the perception that the baby’s appetite is less than other babies and with concern that the infant would become underweight in the future. Maternal perceptions of infant feeding and weight should be incorporated into early obesity prevention strategies.

Maternal Infant Feeding Behaviors and Disparities in Early Child Obesity

BACKGROUND Although disparities in child obesity exist during infancy, the underlying mechanisms are unclear. Assessing dissimilarities in feeding practices, styles, and beliefs may provide a better understanding of these mechanisms. This study sought to identify modifiable maternal-infant feeding behaviors that may contribute to disparities in early child obesity. METHODS This study is a cross-sectional analysis comparing mothers with infants (2 weeks to 6 months old) in a low-risk group of high-income white mothers to a high-risk group of low-income Hispanic mothers. Regression analysis was used to explore relationships between each group and (1) infant feeding practices, including breastfeeding, giving juice, and adding cereal to bottles, (2) controlling feeding styles, (3) beliefs about infant hunger and satiety, and (4) infant weight status. RESULTS The sample included 412 mothers (low-risk group, n = 208; high-risk group, n = 204). The high-risk group was less likely to exclusively breastfeed (adjusted odds ratio [AOR], 0.43; 95% confidence interval [CI], 0.22-0.83), more likely to introduce juice (AOR, 12.25; 95% CI, 3.44-43.62), and add cereal to the bottle (AOR, 10.61; 95% CI, 2.74-41.0). The high-risk group exhibited greater restrictive and pressuring feeding styles and was more likely to believe that mothers can recognize infant hunger and satiety and less likely to believe that infants know their own hunger and satiety. High-risk infants were more likely to have a weight-for-length percentile >85th percentile (AOR, 2.66; 95% CI, 1.10-6.45). CONCLUSIONS Differences in infant feeding behaviors may contribute to disparities in early child obesity. Longitudinal studies are needed to determine the effect of these differences on child obesity.

Randomized controlled trial of an early child obesity prevention intervention: Impacts on infant tummy time

To describe infant activity at 3 months old and to test the efficacy of a primary care‐based child obesity prevention intervention on promoting infant activity in low‐income Hispanic families.