Sexual signal evolution and patterns of assortative mating across an intraspecific contact zone.

Contact zones provide important insights into the evolutionary processes that underlie lineage divergence and speciation. Here, we use a contact zone to ascertain speciation potential in the red-eyed treefrog (Agalychnis callidryas), a brightly coloured and polymorphic frog that exhibits unusually high levels of intraspecific variation. Populations of A. callidryas differ in a number of traits, several of which are known sexual signals that mediate premating reproductive isolation in allopatric populations. Along the Caribbean coast of Costa Rica, a ~100 km contact zone, situated between two phenotypically and genetically divergent parent populations, contains multiple colour pattern phenotypes and late-generation hybrids. This contact zone provides the opportunity to examine processes that are important in the earliest stages of lineage divergence. We performed analyses of colour pattern variation in five contact zone sites and six parental sites and found complex, continuous colour variation along the contact zone. We found discordance between the geographic distribution of colour pattern and previously described genomic population structure. We then used a parental site and contact zone site to measure assortative mating and directional selection from naturally-occurring amplectant mating pairs. We found assortative mating in a parental population, but no assortative mating in the contact zone. Furthermore, we uncovered evidence of directional preference towards the adjacent parental phenotype in the contact zone population, but no directional preference in the parent population. Combined, these data provide insights into potential dynamics at the contact zone borders and indicate that incipient speciation between parent populations will be slowed.

Parenting a Toddler in the Era of Pervasive Screens: Interviews with Low-Income Mexican American Parents.

Screen media use starts in early childhood, despite recommendations to limit use. This study explored low-income Mexican American mothers' and fathers' beliefs, parenting practices, and perceived contextual contributors related to toddler screen use. We conducted interviews with 32 low-income Mexican American parents. Transcripts of audio recordings were analyzed to identify themes. Parents perceived numerous benefits to screen use, including learning and enjoyment, as well as seeing it as a helpful tool for parents. Reported risks included harmful mental and physical effects and a risk of use being all-consuming. Parents managed screen use with a variety of practices, including giving close attention to content, monitoring duration, and engaging in co-use. They also used screens for behavior management and in specific situations, such as to prepare for sleep. Some differences in beliefs and parenting practices exist by screen device type. Parents also reported that contextual factors, such as weather and neighborhood safety, influenced screen use. This study extends the current literature regarding child screen use, with its focus on low-income Mexican American toddlers. The findings offer interventionists and providers insight into the management of screens in the lives of this population.

Screen-related discord and dismay in low-income Mexican American families with toddlers: A qualitative study.

PURPOSE: Understanding parental experiences with managing their toddler's screen use is important to inform the design of interventions addressing early childhood screen use, yet current evidence is limited. To enhance our understanding of the context of toddler screen use, this study characterizes the screen-related discord and dismay parents experience in families with toddlers. DESIGN AND METHODS: In-depth interviews were conducted to explore everyday experiences with screen use among low-income Mexican American caregivers of toddlers (21 mothers, 10 fathers, 1 grandmother). Transcripts were content analyzed to identify prominent themes. RESULTS: Three themes were identified. Experiences of screen-related discord and dismay arose (1) between parent and child, (2) between parents, and (3) surfaced as parental internal dissonance about toddler screen use. Parent-child discord resulted from parental limit setting and child reactions to parental screen use, which often included tantrums. Parent-partner discord included patterns of agreeing to disagree and direct disagreement between partners. Parents also reported their own feelings of ambivalence and dismay as they struggled to reconcile their preferences against their toddler's actual screen use, while living in a screen-saturated world. CONCLUSIONS: Findings offer insight into types of screen-related discord and dismay low-income Mexican American parents experience as they attempt to manage their toddler's screen use. PRACTICE IMPLICATIONS: Although discord in families is normal, the screen-specific discord reported by participants warrants consideration in efforts promoting healthy screen use in families. Providers can tailor their counseling to consider the range of screen-related discord families of toddlers may experience.

Style of meal service and feeding practices among Mexican American fathers and mothers: An analysis of video-recorded children's evening mealtime at home.

The aim of this study was to examine video-recorded observations of evening family mealtime at home among Mexican American children to help elucidate style of meal service, fathers' and mothers' feeding practices and child's eating behavior. Consistent with guidelines for coding behaviors, we analyzed observational data of evening mealtimes of 71 Mexican American children aged eight to 10 years. Regarding style of meal service, in almost all cases (96%), parents plated the child's food, with more available on the table or counter in 40% of the observations. Mothers almost always served the child (94%). Regarding parental feeding practices, parents used positive involvement in meals (80%), pressure to eat (42%) and restriction of food (9%). Using food as a reward to control behavior was never used by either parent. The majority (75%) of children requested or negotiated to eat less food, or only eat certain items. In Mexican American families, both mothers and fathers play a role in family mealtimes and both use positive involvement in child's meals, and to a lesser extent pressure to eat, with their children aged eight to 10 years. To help reduce the obesity epidemic, intervention strategies are needed, which integrate the family, a plating style of meal and parental feeding practices that promote healthy eating in the home. To reduce obesity among Mexican American children, interventions that focus on parental positive involvement in child's meal and maintenance of home cooked meals could have a positive impact on the entire family.

Changes in the Prevalence of Symptoms of Depression, Loneliness, and Insomnia in U.S. Older Adults With Type 2 Diabetes During the COVID-19 Pandemic: The Look AHEAD Study.

OBJECTIVE: To evaluate changes in the prevalence of depressive symptoms, loneliness, and insomnia among older adults with type 2 diabetes from 2016 to 2020 and to assess risk factors for these conditions including demographics, multimorbidity, BMI, treatment group, and pre-coronavirus 2019 (COVID-19) measure scores. RESEARCH DESIGN AND METHODS: This was a prospective, observational study of participants from the Look AHEAD (Action for Health in Diabetes) cohort study. Data were from two assessments before COVID-19 (visit 1: April 2016-June 2018 and visit 2: February 2018-February 2020) and one assessment during COVID-19 (visit 3: July-December 2020). Surveys were administered to assess depressive symptoms, loneliness, and insomnia. RESULTS: The study included 2829 adults (63.2% female, 60.6% White, mean [SD] age 75.6 [6.0] years). The prevalence of mild or greater depressive symptoms did not change significantly between the two pre-pandemic visits (P = 0.88) but increased significantly from pre- to during COVID-19 (19.3% at V2 to 30.4% at V3; P < 0.001). Higher odds of mild or greater depressive symptoms at V3 were associated with being female (adjusted odds ratio [OR] 1.4 [95% CI 1.1-1.7]), identifying as non-Hispanic White (OR 1.4 [95% CI 1.1-1.7]), having obesity (OR 1.3 [95% CI 1.0-1.5]), and reporting mild or greater depressive symptoms at V1 (OR 4.0 [95% CI 2.9-5.4]), V2 (OR 4.4 [95% CI 3.2-5.9]), or both visits (OR 13.4 [95% CI 9.7-18.4]). The prevalence of loneliness increased from 12.3% at V1 to 22.1% at V3 (P < 0.001), while the prevalence of insomnia remained stable across visits at 31.5-33.3%. CONCLUSIONS: The prevalence of mild or greater depressive symptoms in older adults with diabetes was more than 1.6 times higher during COVID-19 than before the pandemic.

Updated distribution maps of predominant Culex mosquitoes across the Americas.

BACKGROUND: Estimates of the geographical distribution of Culex mosquitoes in the Americas have been limited to state and provincial levels in the United States and Canada and based on data from the 1980s. Since these estimates were made, there have been many more documented observations of mosquitoes and new methods have been developed for species distribution modeling. Moreover, mosquito distributions are affected by environmental conditions, which have changed since the 1980s. This calls for updated estimates of these distributions to understand the risk of emerging and re-emerging mosquito-borne diseases. METHODS: We used contemporary mosquito data, environmental drivers, and a machine learning ecological niche model to create updated estimates of the geographical range of seven predominant Culex species across North America and South America: Culex erraticus, Culex nigripalpus, Culex pipiens, Culex quinquefasciatus, Culex restuans, Culex salinarius, and Culex tarsalis. RESULTS: We found that Culex mosquito species differ in their geographical range. Each Culex species is sensitive to both natural and human-influenced environmental factors, especially climate and land cover type. Some prefer urban environments instead of rural ones, and some are limited to tropical or humid areas. Many are found throughout the Central Plains of the USA. CONCLUSIONS: Our updated contemporary Culex distribution maps may be used to assess mosquito-borne disease risk. It is critical to understand the current geographical distributions of these important disease vectors and the key environmental predictors structuring their distributions not only to assess current risk, but also to understand how they will respond to climate change. Since the environmental predictors structuring the geographical distribution of mosquito species varied, we hypothesize that each species may have a different response to climate change.

Increased TLR/MyD88 signaling in patients with obesity: is there a link to COVID-19 disease severity?

COVID-19 is a pandemic disease caused by a coronavirus, designed as SARS CoV-2, whose clinical presentation is widely variable, with most patients having mild or no symptoms, but others developing a malign disease with multi-organ failure and even death. Accumulating data from different populations have shown that obesity is a risk factor for a severe evolution of the disease, however, the mechanisms that explain this association are not clearly understood. An ominous evolution of COVID-19 has been attributed to an exacerbated inflammatory response, designed as "cytokine storm" with augmented production of cytokines/chemokines through the activation of toll-like receptors (TLR) by pathogen-associated molecular patterns, that triggers an inflammatory downstream response, mediated in part by the adaptor molecule, myeloid differentiation factor 88 (MyD88). Previous studies have reported an increased expression of MyD88 and TLRs in people with obesity, mainly in those with metabolic complications. Therefore, we hypothesize, that an underlying increased Myd88/TLR signaling may predispose to patients with obesity to develop an exaggerated and dangerous inflammatory reaction against SARS CoV-2 infection, explaining at least in part, the higher severity of COVID-19. In addition, MyD88/TLR signaling in people with obesity could have a role in the development of several chronic diseases.

Sex ratio of Western Bluebirds Sialia mexicana is mediated by phenology and clutch size.

Mothers may produce more of one sex to maximize their fitness if there are differences in the cost of producing each sex or there are differences in their relative reproductive value. Breeding date and clutch size are known to influence offspring sex ratios in birds through sex differences in dispersal, social behaviours, differential mortality, and available food resources. We tested if breeding date, clutch size and drought conditions influenced offspring sex ratios in a sexually size-monomorphic species, the Western Bluebird, by interrogating a 21-year dataset. After controlling for differential mortality, we found that hatch dates late in the breeding season were associated with the production of more females, suggesting that the value of producing males declines as the breeding season progresses. When clutch size was taken into account, small clutches yielded significantly more females late in the breeding season compared to the early and middle parts of the breeding season that produced significantly more males. Large clutches early in the season tended to produce more females, although this was not significant. Drought severity was not correlated with sex ratio adjustment. We propose and discuss several explanations for these patterns, including male offspring, but not female offspring, acting as helpers, increased female nestling provisioning late in the breeding season, differences in food abundance, and egg-laying order. Future work will help to uncover the mechanisms leading to these patterns. Identifying patterns and mechanisms of sex ratio skew from long-term datasets is important for informing predictions regarding life-history trade-offs in wildlife populations.

Chamomile Gel versus Urea Cream to Prevent Acute Radiation Dermatitis in Head and Neck Cancer Patients: Results from a Preliminary Clinical Trial.

We assessed safety and potential efficacy of a chamomile gel compared with urea cream to prevent acute radiation dermatitis in head and neck cancer patients. We assessed safety and potential efficacy of the chamomile gel in escalating concentrations of 2.50%, 5.00% and 8.35% of chamomile. Concentration of 8.35% was chosen for a randomized trial comparing chamomile gel (8.35%) with urea cream (n = 24 per group), for potential efficacy to delay or prevent radiation dermatitis in these patients. Preliminary results demonstrate a delayed onset of dermatitis, with onset of Grade 2 dermatitis at 5.1 (1.3) weeks in the chamomile group and 4.5 (1.3) weeks in the urea group (effect size of 0.46). Itching, burning and hyperpigmentation were more frequently reported in the urea group. Results indicates a potential efficacy of the chamomile gel. Further studies are needed to confirm the effect of the chamomile gel in reducing or delaying the occurrence of radiation dermatitis.

Genetic Diversity in Invasive Populations of Argentine Stem Weevil Associated with Adaptation to Biocontrol.

Modified, agricultural landscapes are susceptible to damage by insect pests. Biological control of pests is typically successful once a control agent has established, but this depends on the agent's capacity to co-evolve with the host. Theoretical studies have shown that different levels of genetic variation between the host and the control agent will lead to rapid evolution of resistance in the host. Although this has been reported in one instance, the underlying genetics have not been studied. To address this, we measured the genetic variation in New Zealand populations of the pasture pest, Argentine stem weevil (Listronotus bonariensis), which is controlled with declining effectiveness by a parasitoid wasp, Microctonus hyperodae. We constructed a draft reference genome of the weevil, collected samples from a geographical survey of 10 sites around New Zealand, and genotyped them using a modified genotyping-by-sequencing approach. New Zealand populations of Argentine stem weevil have high levels of heterozygosity and low population structure, consistent with a large effective population size and frequent gene flow. This implies that Argentine stem weevils were able to evolve more rapidly than their biocontrol agent, which reproduces asexually. These findings show that monitoring genetic diversity in biocontrol agents and their targets is critical for long-term success of biological control.

An Exploratory Study Demonstrating the Health Information Management Profession as a STEM Discipline.

It is time to make the case for health information management (HIM) to be included in science, technology, engineering, and math (STEM) education. A careful review of the HIM competencies approved by the American Health Information Management Association (AHIMA) illustrates the role of HIM professionals in informatics, data analytics, and data use. More precisely, the competency subdomains clearly align with content in the STEM disciplines of science, math, and technology, and the individual competencies or tasks in each subdomain solidify the assertion that HIM should be considered part of the STEM disciplines. Evaluation of AHIMA membership data showed that, at the education and work setting levels, AHIMA members are employed in many areas that are common to both HIM and STEM.

Sleep duration in Mexican American children: Do mothers' and fathers' parenting and family practices play a role?

This study examined parenting styles, parenting practices and family practices that may be associated with weeknight sleep duration among 8- to 10-year-old Mexican American (MA) children. This cross-sectional study of MA children used baseline data from a 2-year cohort study of mother-child pairs (n = 308) with additional data on fathers (n = 166). Children's weeknight sleep duration was accelerometer estimated and averaged for 2 weeknights. Parents reported on their parenting styles and practices regarding food and family food-related practices. Multivariable linear regression analysis was used to examine sleep duration with parenting styles and practices, and family practices, and adjusting for child gender and body mass index. Model 1 included mothers' parenting styles and practices; Model 2 included both mothers' and fathers' parenting styles and practices. Children's average sleep duration was 9.5 (SD = 0.8) hr. Mothers who used pressure to encourage their children to eat and those who used food to control behavior had children with longer sleep duration (ß = 0.21, p < 0.01; ß = 0.15, p = 0.03, respectively). Mothers who reported their children ate dinner with the TV on and those who valued eating dinner as a family had children with shorter sleep duration (ß = -0.16, p = 0.01; ß = -0.18, p = 0.01, respectively). Fathers who restricted the amount of food their children ate had children with shorter sleep duration (ß = -0.27, p = 0.01). Mothers' and fathers' feeding practices, the child's eating dinner with the TV on, and valuing family dinners, played a role in children's weeknight sleep duration among Mexican American families. Parental feeding practices and family mealtime contexts may have an effect on children's weeknight sleep duration.

Screen-Related Parenting Practices in Low-Income Mexican American Families.

OBJECTIVES: To (1) examine whether the Information-Motivation-Behavioral Skills Model predicts maternal screen-related parenting practices and (2) evaluate the relationship of American Academy of Pediatrics (AAP)-recommended parenting practices with child television (TV) use behaviors. METHODS: In this cross-sectional study, 312 Spanish-speaking and/or English-speaking female primary caregivers of Mexican descent with a child 3 to 5 years of age were recruited from safety-net pediatric clinics. Participants completed a phone interview and screen media diary. Measures included maternal screen-related beliefs, self-efficacy, parenting practices (time restriction, TV in the child's bedroom, allowing viewing while eating meals and while eating snacks), and child viewing behaviors (amount of TV viewing, frequency of eating while viewing). Two path analytic models were estimated. RESULTS: Positive general beliefs about TV viewing and positive functional beliefs were negatively associated with maternal self-efficacy to restrict TV time (ß = -0.14, P < .05; ß = -0.27, P < .001). Greater self-efficacy to restrict time was associated with more maternal restriction of time (ß = 0.29, P < .001). Greater positive functional beliefs were associated with less self-efficacy to restrict TV viewing with snacks (odds ratio = 0.56; 95% confidence interval, 0.38-0.81). High self-efficacy to restrict viewing with snacks was associated with less allowing of viewing while snacking (ß = -0.16, P < .01). Time restriction, TV in the child's bedroom, and allowing viewing while snacking were associated with child TV viewing behaviors. CONCLUSIONS: Providers should consider maternal beliefs, including beliefs regarding the functional use of screens, and self-efficacy to engage in AAP-recommended parenting practices, when counseling on screen use in this population.

Beliefs About Child TV Viewing in Low-Income Mexican American Parents of Preschoolers: Development of the Beliefs About Child TV Viewing Scale (B-TV).

Objectives Parental beliefs about child television viewing may affect the way parents regulate child television viewing. Despite this, little research has focused on the development of measures of parental beliefs about child television viewing, particularly among ethnic minority parents and parents of young children. This study's objective was to develop and test a culturally-based measure of parental beliefs about television viewing in low-income Mexican American mothers of preschoolers. Methods Using a cross-sectional study design, 22 items reflecting parental beliefs about influences of TV on children were developed and assessed for psychometric properties in a sample of 312 low-income Mexican American mothers of preschoolers. Results Using exploratory factor analysis, we identified four factors reflecting four domains of parental beliefs: positive general beliefs, positive sleep-related beliefs, positive functional beliefs, and negative general beliefs. Internal reliabilities were acceptable (Cronbach's alpha = 0.70-0.89) for all factors except negative general beliefs (Cronbach's alpha = 0.61). Positive sleep-related beliefs and Positive Functional Beliefs were correlated with children's average daily hours of TV (r = 0.16, p < .01; r = 0.22, p < .001, respectively) and with mother's average daily hours of TV (r = 0.14, p < .05; r = 0.22, p < .001, respectively), providing initial support for construct validity. Conclusions for Practice The Beliefs about Child TV viewing scale measures four domains of parental beliefs regarding child TV viewing, and has good initial reliability and validity for three factors. Future use will allow investigators to conduct more in-depth evaluations on the influence of parental beliefs on the way parents shape their child's use of the TV.

Fathers' feeding practices and children's weight status in Mexican American families.

Mothers' feeding practices are associated with their children's weight status, but little is known about the associations between fathers' feeding practices and children's weight status. Moreover, there is a dearth of research on Latino fathers' feeding practices and children's weight status, even though Latino children suffer some of the highest obesity rates in the U.S. We examined the associations between fathers' feeding practices and child weight status, conditional on mothers' feeding practices, within 174 Mexican American families with children aged 8-10 years. Parents completed the Parental Feeding Practices Questionnaire, which consists of four subscales: positive involvement in child eating, pressure to eat, use of food to control behavior, and restriction of amount of food. To assess child weight status, body mass index (BMI) was calculated and converted to age- and gender-specific percentile scores (BMI z-score). We fit four sets of regression models, one set for each of the four parental feeding practices subscales, with child BMI z-score as the outcome variable. Fathers' pressure to eat (b = -0.20, p = 0.04; 95% CI: -0.39, -0.01) and use of food to control behavior (b = -0.36, p = 0.02; 95% CI: -0.65, -0.07) were associated with lower child BMI z-score, and restriction of amount of food (b = 0.56, p < 0.001; 95% CI: 0.27, 0.84) was associated with higher child BMI z-score, after accounting for mothers' feeding practices. Fathers' positive involvement in child eating was not associated with child BMI z-score. These findings provide empirical evidence that fathers' feeding practices are independently associated with children's weight status, even when mothers' feeding practices are taken into account, and suggest that fathers' feeding practices also matter in regard to children's weight status.

Low and High Birth Weights Are Risk Factors for Nonalcoholic Fatty Liver Disease in Children.

OBJECTIVES: To examine the distribution of birth weight in children with nonalcoholic fatty liver disease (NAFLD) compared with the general US population, and to investigate the relationship between birth weight and severity of NAFLD. STUDY DESIGN: A multicenter, cross-sectional study of children with biopsy-proven NAFLD enrolled in the Nonalcoholic Steatohepatitis Clinical Research Network Database. Birth weight was categorized as low birth weight (LBW), normal birth weight (NBW), or high birth weight (HBW) and compared with the birth weight distribution in the general US population. The severity of liver histology was assessed by birth weight category. RESULTS: Children with NAFLD (n = 538) had overrepresentation of both LBW and HBW compared with the general US population (LBW, 9.3%; NBW, 75.8%; HBW, 14.9% vs LBW, 6.1%; NBW, 83.5%; HBW 10.5%; P < .0001). Children with HBW had significantly greater odds of having more severe steatosis (OR, 1.82, 95% CI. 1.15-2.88) and nonalcoholic steatohepatitis (OR, 2.03; 95% CI, 1.21-3.40) compared with children with NBW. In addition, children with NAFLD and LBW had significantly greater odds of having advanced fibrosis (OR, 2.23; 95% CI, 1.08-4.62). CONCLUSION: Birth weight involves maternal and in utero factors that may have long-lasting consequences. Children with both LBW and HBW may be at increased risk for developing NAFLD. Among children with NAFLD, those with LBW or HBW appear to be at increased risk for more severe disease.

Short Sleep Duration Is Associated With Eating More Carbohydrates and Less Dietary Fat in Mexican American Children.

Study Objective: Short sleep duration is a risk factor for childhood obesity. Mechanisms are unclear, but may involve selection of high carbohydrate foods. This study examined the association between estimated sleep duration and macronutrient intake as percentages of total energy among Mexican American (MA) 9-11 year olds. Methods: This cross-sectional study measured diet using two 24-hour recalls and estimated sleep duration using hip-worn accelerometry in MA children (n = 247) who were part of a cohort study. Child and maternal anthropometry were obtained; mothers reported on demographic information. Using linear regression, we examined the relationship of sleep duration with energy intake, sugar intake, and the percentage of energy intake from carbohydrates, fat, and protein. Results: Children were 47% male; mean age was 10 (SD = 0.9) years. Mean sleep duration was 9.6 (SD = 0.8) hours; 53% were overweight/obese, with a mean energy intake of 1759 (SD = 514) calories. Longer sleep duration was independently associated with a lower percentage of energy intake from carbohydrates (ß = -0.22, p < .01) and a higher percentage of energy from fat (ß = 0.19, p < .01), driven by the percentage of energy from polyunsaturated fatty acids (PUFA; ß = 0.17, p < .05). No association was found with the intake of energy or total sugars, or the percent of calories from protein. Conclusions: MA children who slept longer consumed diets with a lower percentage of calories from carbohydrates and a higher percentage from fat, especially from PUFA. Short sleep duration may be a risk factor for food cravings that are high in carbohydrate content and may displace heart-healthy dietary fat, and thereby increase obesity risk among children.

Expression of MYD88 in Adipose Tissue of Obese People: Is There Some Role in the Development of Metabolic Syndrome?

BACKGROUND: The mechanism leading to the development of metabolic complications in obese individuals is not fully understood. Thus, the objective of this study was to examine differences in insulin resistance, inflammation, cytokine and adipokine levels, and expression of selected genes across obese individuals with different number of metabolic syndrome (MetS) components. METHODS: Forty obese individuals who underwent bariatric surgery, divided in three groups based on the number of components of MetS, in addition to abdominal obesity (0, 1, and 2-3 additional components), were studied. Levels of inflammatory proteins, insulin resistance, cytokines, adipokines, and gene expression in subcutaneous (SAT) and visceral adipose tissue (VAT) were compared. RESULTS: There was a significantly higher expression of MYD88 in SAT among those with more components of MetS (P = 0.008). In SAT, but not in VAT, MYD88 expression was significantly correlated with toll-like receptor 4 expression (r = 0.7, P < 0.05). Expression of adipsin in SAT was also associated with the presence of more components of MetS, but with borderline statistical significance (P = 0.05). There were no significant differences in insulin resistance, inflammation, and cytokine and adipokine levels by the number of components of MetS. CONCLUSIONS: Our study suggests that MYD88 expression in SAT of obese subjects could be associated with the development of components of MetS.

Parenting and Preschooler TV Viewing in Low-Income Mexican Americans: Development of the Parenting Practices Regarding TV Viewing (PPRTV) Scale.

OBJECTIVE: To develop and test a comprehensive, culturally based measure of parenting practices regarding television (TV) viewing in low-income Mexican-American mothers of preschoolers. METHOD: Low-income Mexican-American female primary caregivers of preschoolers were recruited in urban safety-net pediatric clinics during the 2013 to 2014 academic year. Items on parenting practices regarding TV viewing were developed from a prior scale, review of the literature, and results from semistructured interviews. Items were administered by phone, and analyses included evaluation of the factor structure and psychometric properties of a 40-item measure of parenting practices regarding TV viewing (PPRTV). RESULTS: Using exploratory factor analysis, a 7-factor model emerged as the best fit for the data representing the following domains of parenting practices: time restriction, behavioral control, instructive practices, coviewing, planful restriction, reactive content restriction, and commercial endorsement. Internal reliabilities were acceptable (Cronbach's alpha >.75). Correlations among the resulting subscales were small to moderate (rs = 0.01-0.43). Subscales were correlated with child TV viewing amounts: time restriction (-0.14, p < .05); behavioral control (0.27, p < .001); coviewing (0.16, p < .01); planful restriction (-0.20, p < .001); and commercial endorsement (0.11, p < .05), which provides support for construct validity. CONCLUSION: The PPRTV scale measures 7 domains of parenting practices and has good initial reliability and validity. It allows investigators to conduct more in-depth evaluations of the role parents play in socializing young children on TV use. Results of such work will be important to informing the design of interventions aiming to ensure healthy screen media habits in young children.