Differences in Socioeconomic, Dietary Choice, and Nutrition Environment Explanatory Variables for Food and Nutrition Security among Households with and without Children.

This study's purpose was to compare socioeconomic, dietary choice, and nutrition environment variables associated with food and nutrition security in USA households with and without children. Data were collected in 2021 and consisted of households at risk of or experiencing food insecurity. Multivariable logistic regression was used to identify significant explanatory variables for food and nutrition security by household type-with or without children (<18 years of age). Food insecurity rates were 74% and 64% in households with and without children, respectively. Nutrition insecurity rates were 38% and 30% in households with and without children, respectively. For both household types, greater dietary choice increased odds (4-15 times) of food and nutrition security. In households with children, more fast-food meals increased the odds (60%) of food security, while more processed meals and greater utilization barriers to healthful meals decreased the odds (40-50%). Greater utilization barriers also decreased the odds (20%) of food security in households without children. In households with children, higher income and greater healthfulness choice increased the odds (20% and 3 times) of nutrition security, while low (vs. high) perceived limited availability of foods doubled the odds in households without children. Dietary choice is an influential and crucial factor of food and nutrition security.

Direct and Indirect Effects of Food and Nutrition Security on Dietary Choice and Healthfulness of Food Choice: Causal Mediation Analysis.

Background: Links between diet and food security are well established, but less is known about how food and nutrition security affect a household's ability to decide what to consume. Objectives: This study's purpose was to quantify and compare causal pathways from 1) food and nutrition security to perceived dietary choice and 2) food and nutrition security to perceived healthfulness of food choice while testing for mediation by perceived limited availability of foods and utilization barriers to healthful meals. Methods: Causal mediation analysis was conducted using an observational data set. Exposures included food insecurity and nutrition insecurity; mediators included perceived limited availability and utilization barriers; outcomes included perceived dietary choice and healthfulness choice; covariates included income and education. Results: Dietary choice (range 0-4) was 0.9 to 1.1 points lower for participants with food/nutrition insecurity compared with participants with food/nutrition security (direct effects). Neither mediation nor moderation by perceived limited availability were present. Seventeen percent and 11 %, respectively, of the effects of food and nutrition security on dietary choice could be contributed to utilization barriers (mediation). Moderation by utilization barriers was present only for nutrition security (differences in dietary choice only present when barriers were low). Healthfulness choice (range 0-4) was 0.6 to 0.7 points lower for participants with food/nutrition insecurity compared with participants with food/nutrition security (direct effects). Mediation by perceived limited availability and utilization barriers was not present. Moderation was present only for nutrition security (differences in healthfulness choice only present when perceived limited availability was low; differences in healthfulness choice only present when barriers were low). Conclusions: Food and nutrition security affect food choices, with utilization barriers acting as an intermediary step. When environmental and household utilization barriers to healthful food purchasing and preparation are high, the ability to decide what to consume does not differ between households with nutrition security and those with nutrition insecurity.

Mississippi School Food Service Directors' Interest and Experience With Local Food Procurement and Farm to School Activities.

BACKGROUND.: The purpose of this study was to collect updated school food service purchasing practices from K-12 public school food service directors (SFSD) in Mississippi and to determine their current abilities, experiences, and desires to engage in Farm to School (F2S) activities. METHODS.: The online survey was created using questionnaire items from existing F2S surveys. The survey opened in October 2021 and closed in January 2022. Descriptive statistics were used to summarize the data. RESULTS.: Of the 173 SFSD sent email invitations, 122 (71%) completed the survey. The most common fresh fruit and vegetable purchasing practices included Department of Defense Fresh Program (65%) and produce vendor (64%). Forty-three percent of SFSD purchased at least one locally sourced fruit and 40% purchased at least one locally sourced vegetable, while 46% did not purchase any locally sourced foods. The most common challenges for purchasing from farmers included no relationship with farmers (50%) and food safety regulations (39%). Sixty-four percent of SFSD were interested in at least one F2S activity. CONCLUSIONS.: Most SFSD do not purchase local foods directly from farmers and almost half do not purchase any local foods regardless of source. Lack of connection with local farmers is a significant challenge to F2S. Recently proposed framework by USDA for shoring up the food supply chain and transforming the food system may help reduce or remove ongoing challenges to F2S participation.

Similarities and Dissimilarities in Diet Quality Differences by Acculturation Level between Mexican Americans and Other Hispanic Americans: National Health and Nutrition Examination Survey 2015-2018.

BACKGROUND: Evidence suggests dietary acculturation can increase obesity and chronic disease risks. However, acculturation effects on diet quality among subgroups of Hispanic Americans is not well studied. OBJECTIVES: Estimating percentages of Hispanic Americans with low, moderate, and high acculturation using 2 proxy measures with different language variables was the first objective. Identifying similarities and dissimilarities in diet quality differences by acculturation level between Mexican Americans and other Hispanic Americans was the second objective. METHODS: The study sample included 1733 Mexican American and 1191 other Hispanic participants aged ≥16 y from National Health and Nutrition Examination Survey 2015-2018. Proxy measures included in the 2 acculturation scales were nativity/United States residence length, immigration age, language spoken at home (home), and language of dietary recall (recall). Replicate 24-h dietary recalls were conducted, and diet quality was assessed using the 2015 Healthy Eating Index. Analyses included statistical methods for complex survey designs. RESULTS: For Mexican Americans, 8%, 35%, and 58% had low, moderate, and high acculturation on the home scale compared with 8%, 30%, and 62% on the recall scale. For other Hispanics, 17%, 39%, and 43% had low, moderate, and high acculturation on the home scale compared with 18%, 34%, and 48% on the recall scale. Similarities between ethnicities included higher acculturation associated with lower intakes of fruits, vegetables, total protein foods, seafood and plant proteins, and saturated fats and greater intake of sodium. Dissimilarities included higher acculturation associated with more whole grains and added sugars intakes and less refined grains intake (Mexican Americans), and less total dairy and fatty acids intakes (other Hispanic Americans). CONCLUSIONS: Higher acculturation is associated with worsening diet quality for fruits, vegetables, and protein foods in all Hispanic Americans. However, associations of higher acculturation with worsening diet quality for grains, added sugars, dairy, and fatty acids were present only in specific subgroups of Hispanic Americans.

Relationships among Acculturation Using 2 Different Language Variables, Diet Quality, and Accuracy of Diet Quality Assessment in Non-Hispanic Asians Residing in the United States.

BACKGROUND: Evidence suggests that acculturation can increase risks of poor diet, obesity, and chronic diseases. Yet questions remain regarding acculturation proxy measures and associations with diet quality in Asian Americans. OBJECTIVES: Primary objectives included estimating percentages of Asian Americans with low, moderate, and high acculturation using 2 proxy measures of acculturation based on different language variables and determining if diet quality differences existed among acculturation levels using the 2 proxy acculturation measures. METHODS: Study sample included 1275 Asian participants aged ≥16 y from National Health and Nutrition Examination Survey 2015-2018. Nativity/length of United States residence, immigration age, language spoken at home (home), and language of dietary recall (recall) were used as proxy measures for 2 acculturation scales. Replicate 24-h dietary recalls were conducted and diet quality was assessed using 2015 Healthy Eating Index. Statistical methods for complex survey designs were used for analysis. RESULTS: Using home and recall language, 26% compared with 9% of participants were classified with low, 50% compared with 63% with moderate, and 24% compared with 28% with high acculturation. On the home language scale, participants with low and/or moderate acculturation had higher scores (0.5-5.5 points) for vegetables, fruits, whole grains, seafood and plant protein, saturated fats, added sugars, and total 2015 Healthy Eating Index than participants with high acculturation; participants with low acculturation had lower refined grain score (1.2 points) than participants with high acculturation. Results were similar for the recall language scale, except differences between participants with moderate and high acculturation were also observed for fatty acids. CONCLUSIONS: Although percentages of Asian Americans classified with low, moderate, and high acculturation differed between the 2 proxy measures for acculturation, diet quality differences among acculturation groups were remarkably similar between the 2 proxy measures. Hence, use of either language variables may yield comparable results regarding the relationships between acculturation and diet in Asian Americans.

Mississippi Small Farm Product Amounts, Seasonality, and Proximity to K-12 Public Schools.

The study's purpose was to determine small farm product amounts and seasonality and examine spatial relationships between small farms and K-12 public schools in Mississippi. Online survey participation invitations were sent via email to farmers and school food service directors from October 2021 to January 2022. Data were summarized using descriptive statistics and proximities between farms (n = 29) and schools (n = 122) determined using spatial analysis. Median yearly amounts for both fresh fruits and vegetables ranged from 1-50 to 201-500 pounds while other product amounts ranged from 1-50 to >1000 pounds. Fresh fruits, fresh vegetables, and other product seasonality ranged from 1 to 6 months, 1 to 12 months, and 3 to 12 months, respectively. In total, 8 out of 12 fresh fruits, 24 out of 25 fresh vegetables, and all other products were harvested during the academic school year. Fifty percent of the schools were within a 20-mile radius of at least one small farm, while 98% were within a 50-mile radius. While many product amounts were small (1-50 pounds), most were harvested during the school year and in close proximity to at least one school. Contracting directly with farmers may be more attractive to school food authorities given current supply chain disruptions and decreasing product availability for school meal programs.

Can United States Adults Accurately Assess Their Diet Quality?

PURPOSE: To estimate the percentage of United States adults who accurately assessed their diet quality (DQ). DESIGN: Observational, cross-sectional, nationally representative. SETTING: National Health and Nutrition Examination Survey, 2015-2018. SAMPLE: 9757 (86%) of 11 288 adults aged ≥20 years. MEASURES: Perceived DQ was assessed by asking participants, how healthy is your diet? The five responses included excellent, very good, good, fair, and poor. Measured DQ was assessed using 24-hours dietary recalls scored with 2015 Healthy Eating Index; scores were categorized using a 10-point grading scale. ANALYSIS: Matches between perceived and measured DQ that were classified as accurate included: excellent = A, very good = A or B, good = B or C, fair = C or D, and poor = D or F. All others were classified as inaccurate. Analyses included descriptive statistics and multivariable logistic regression for complex survey designs. RESULTS: 63% of adults perceived their DQ as very good or good while 70% scored DQ grades of F. Overall, 15% of adults accurately assessed their DQ with 96% accuracy in the poor perception group and <23% in the other 4 groups. Overall, 75% of adults overrated their DQ. Females, adults with lower educational attainment, and those with low food security were more likely to accurately assess their DQ. CONCLUSION: Adults cannot accurately assess their DQ except for those perceiving their DQ as poor, and the majority overrate their DQ.

Mississippi Farmers' Interest in and Experience with Farm to School.

The study's purpose was to collect demographic and farm characteristics from Mississippi small farmers and to determine their abilities, experiences, and desires to engage in Farm to School (F2S) activities. The online survey was created using items taken from existing F2S surveys. Invitations to participate were sent via email to farmers beginning in October 2021 and ending in January 2022. Descriptive statistics were used to summarize the data. Of the 258 individuals with valid email addresses, 43 (17%) completed the online survey, and 38 fit the definition of small farm (

Lung volume distribution in preterm infants on non-invasive high-frequency ventilation.

INTRODUCTION: Non-invasive high-frequency oscillatory ventilation (nHFOV) is an extension of nasal continuous positive airway pressure (nCPAP) support in neonates. We aimed to compare global and regional distribution of lung volumes during nHFOV versus nCPAP. METHODS: In 30 preterm infants enrolled in a randomised crossover trial comparing nHFOV with nCPAP, electrical impedance tomography data were recorded in prone position. For each mode of respiratory support, four episodes of artefact-free tidal ventilation, each comprising 30 consecutive breaths, were extracted. Tidal volumes (VT) in 36 horizontal slices, indicators of ventilation homogeneity and end-expiratory lung impedance (EELI) for the whole lung and for four horizontal regions of interest (non-gravity-dependent to gravity-dependent; EELINGD, EELImidNGD, EELImidGD, EELIGD) were compared between nHFOV and nCPAP. Aeration homogeneity ratio (AHR) was determined by dividing aeration in non-gravity-dependent parts of the lung through gravity-dependent regions. MAIN RESULTS: Overall, 228 recordings were analysed. Relative VT was greater in all but the six most gravity-dependent lung slices during nCPAP (all p<0.05). Indicators of ventilation homogeneity were similar between nHFOV and nCPAP (all p>0.05). Aeration was increased during nHFOV (mean difference (95% CI)=0.4 (0.2 to 0.6) arbitrary units per kilogram (AU/kg), p=0.013), mainly due to an increase in non-gravity-dependent regions of the lung (∆EELINGD=6.9 (0.0 to 13.8) AU/kg, p=0.028; ∆EELImidNGD=6.8 (1.2 to 12.4) AU/kg, p=0.009). Aeration was more homogeneous during nHFOV compared with nCPAP (mean difference (95% CI) in AHR=0.01 (0.00 to 0.02), p=0.0014). CONCLUSION: Although regional ventilation was similar between nHFOV and nCPAP, end-expiratory lung volume was higher and aeration homogeneity was slightly improved during nHFOV. The aeration difference was greatest in non-gravity dependent regions, possibly due to the oscillatory pressure waveform. The clinical importance of these findings is still unclear.

Unpacking the behavioural components and delivery features of early childhood obesity prevention interventions in the TOPCHILD Collaboration: a systematic review and intervention coding protocol.

INTRODUCTION: Little is known about how early (eg, commencing antenatally or in the first 12 months after birth) obesity prevention interventions seek to change behaviour and which components are or are not effective. This study aims to (1) characterise early obesity prevention interventions in terms of target behaviours, delivery features and behaviour change techniques (BCTs), (2) explore similarities and differences in BCTs used to target behaviours and (3) explore effectiveness of intervention components in preventing childhood obesity. METHODS AND ANALYSIS: Annual comprehensive systematic searches will be performed in Epub Ahead of Print/MEDLINE, Embase, Cochrane (CENTRAL), CINAHL, PsycINFO, as well as clinical trial registries. Eligible randomised controlled trials of behavioural interventions to prevent childhood obesity commencing antenatally or in the first year after birth will be invited to join the Transforming Obesity in CHILDren Collaboration. Standard ontologies will be used to code target behaviours, delivery features and BCTs in both published and unpublished intervention materials provided by trialists. Narrative syntheses will be performed to summarise intervention components and compare applied BCTs by types of target behaviours. Exploratory analyses will be undertaken to assess effectiveness of intervention components. ETHICS AND DISSEMINATION: The study has been approved by The University of Sydney Human Research Ethics Committee (project no. 2020/273) and Flinders University Social and Behavioural Research Ethics Committee (project no. HREC CIA2133-1). The study's findings will be disseminated through peer-reviewed publications, conference presentations and targeted communication with key stakeholders. PROSPERO REGISTRATION NUMBER: CRD42020177408.

Transforming Obesity Prevention for CHILDren (TOPCHILD) Collaboration: protocol for a systematic review with individual participant data meta-analysis of behavioural interventions for the prevention of early childhood obesity.

INTRODUCTION: Behavioural interventions in early life appear to show some effect in reducing childhood overweight and obesity. However, uncertainty remains regarding their overall effectiveness, and whether effectiveness differs among key subgroups. These evidence gaps have prompted an increase in very early childhood obesity prevention trials worldwide. Combining the individual participant data (IPD) from these trials will enhance statistical power to determine overall effectiveness and enable examination of individual and trial-level subgroups. We present a protocol for a systematic review with IPD meta-analysis to evaluate the effectiveness of obesity prevention interventions commencing antenatally or in the first year after birth, and to explore whether there are differential effects among key subgroups. METHODS AND ANALYSIS: Systematic searches of Medline, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycInfo and trial registries for all ongoing and completed randomised controlled trials evaluating behavioural interventions for the prevention of early childhood obesity have been completed up to March 2021 and will be updated annually to include additional trials. Eligible trialists will be asked to share their IPD; if unavailable, aggregate data will be used where possible. An IPD meta-analysis and a nested prospective meta-analysis will be performed using methodologies recommended by the Cochrane Collaboration. The primary outcome will be body mass index z-score at age 24±6 months using WHO Growth Standards, and effect differences will be explored among prespecified individual and trial-level subgroups. Secondary outcomes include other child weight-related measures, infant feeding, dietary intake, physical activity, sedentary behaviours, sleep, parenting measures and adverse events. ETHICS AND DISSEMINATION: Approved by The University of Sydney Human Research Ethics Committee (2020/273) and Flinders University Social and Behavioural Research Ethics Committee (HREC CIA2133-1). Results will be relevant to clinicians, child health services, researchers, policy-makers and families, and will be disseminated via publications, presentations and media releases. PROSPERO REGISTRATION NUMBER: CRD42020177408.

Patterns of Screen Time Parenting Practices among Parent-Adolescent Dyads Who Participated in a Cross-Sectional Internet-Based Study.

Background: Little is known about the simultaneous use of screen time (ST) parenting practices in children. Hence, study objectives were to determine patterns of ST parenting practices and associations with demographic, anthropometric, and sedentary behavior measures in parents and their adolescent children (12-17 years). Methods: Dyadic survey data from Family Life, Activity, Sun, Health, and Eating, a cross-sectional, internet-based study, conducted in 2014 were analyzed using latent class analysis on six ST parenting practices-permissive, rules/limits, monitoring, modeling, accessibility, and negotiated rules. Self-report model covariates included adolescent age and parent and adolescent sex, body weight category, and sedentary behavior. Results: Based on 1200 parent-adolescent dyads, five latent classes were identified representing a continuum of practice use (high to low)-Complete Influencers (16%, reference class), Disagreeing Influencers (18%), Positive Influencers (24%), Negative Influencers (23%), and Indifferent Influencers (20%). Disagreeing, Indifferent, and Negative Influencers were 50%-81% and 45%-49% less likely to contain younger adolescent dyads and male adolescent dyads, respectively. Dyads with adolescent overweight/obesity had twice the odds of belonging to one of the other four classes. Odds of belonging to one of the other four classes were 3%-9% lower for every 1 minute/day increase in adolescent sedentary behavior. Conclusions: Parents utilize distinct patterns of ST practices, which are differentially associated with adolescent age, sex, weight, and sedentary behavior. Advocating for parental use of combinations of practices, like rules/limits and monitoring, to decrease their adolescents' ST may prove more beneficial than no practice use.

Patterns of physical activity parenting practices among parent-adolescent dyads who participated in a cross-sectional internet-based study.

BACKGROUND: While research exploring relationships between individual parenting practices and child physical activity (PA) exists, little is known about simultaneous use of practices. Hence, study objectives were to determine patterns of PA parenting practices and their associations with demographic, anthropometric, and PA measures in a large sample of parents and their adolescent children (12-17 years). METHODS: Dyadic survey data from Family Life, Activity, Sun, Health, and Eating (FLASHE), a cross-sectional, internet-based study, conducted in 2014 were analyzed using latent class analysis on 5 PA parenting practices - pressuring, guided choice, expectations, facilitation, and modeling. Self-report model covariates included adolescent age and parent and adolescent sex, body mass index category (based on height and weight), legitimacy of parental authority regarding PA (PA-LPA), and moderate-to-vigorous PA (MVPA). RESULTS: Based on 1166 parent-adolescent dyads, four latent classes were identified representing a continuum of practice use (high to low) - Complete Influencers (26%), Facilitating-Modeling Influencers (23%), Pressuring-Expecting Influencers (25%), and Indifferent Influencers (27%). Compared to dyads with parent underweight/healthy weight, dyads with parent overweight/obesity had 84% higher odds of belonging to Indifferent Influencers. Compared to dyads with adolescent underweight/healthy weight, dyads with adolescent overweight/obesity had 50 and 46% lower odds of belonging to Facilitating-Modeling and Indifferent Influencers. Odds of belonging to Pressuring-Expecting and Indifferent Influencers were less than 1% lower for every 1 min/day increase in parent MVPA and 2 and 4% lower for every 1 min/day increase in adolescent MVPA. Compared to dyads with high parental and adolescent agreement with PA-LPA, dyads with low agreement had between 3 and 21 times the odds of belonging to Facilitating-Modeling, Pressuring-Expecting, or Indifferent Influencers. CONCLUSIONS: Findings suggest that parents utilize distinct patterns of PA practices ranging from use of many, use of some, to low use of any practice and these patterns are differentially associated with parent and adolescent PA. When planning PA interventions, a counseling or intervening approach with parents to use combinations of practices, like facilitation and modeling, to positively influence their adolescents' and possibly their own participation in PA may prove more efficacious than parental pressuring or lack of practice use.

Moderation by Neighborhood Food Outlets on Relationships between Meal Sources and Diet.

Objectives: In this study, we tested for moderation by neighborhood food outlet presence on relationships between food outlet shopping or meal sources and dietary intake. Methods: We used generalized linear models to analyze parent-adolescent (12-17 years) dyad data from the 2014 Family Life, Activity, Sun, Health and Eating. Questions included food outlet presence in home (parent) and school (adolescent) neighborhoods (yes or no), shopping at food outlets (parent) (never, rarely, sometimes, often or always), and sources of food consumed away from and at home (weekly frequency). We captured food and beverage intakes via a dietary screener. Results: Relationships between adolescent added sugar intake and scratch cooked evening meals and meals away from home were found only when grocery stores and fast food restaurants, respectively, were present in adolescents' school neighborhoods. Shopping at fruit and vegetable (FV) markets and scratch cooked evening meals were associated with the largest increases in parent and adolescent FV intakes, respectively. Meals away from home at convenience stores were associated with the largest increases in parent and adolescent intakes of added sugars. Conclusions: Neighborhood grocery store and fast food restaurant presence moderated relationships between meal sources and dietary intake only in adolescents.

Imaging the Respiratory Transition at Birth: Unraveling the Complexities of the First Breaths of Life.

Rationale: The transition to air breathing at birth is a seminal respiratory event common to all humans, but the intrathoracic processes remain poorly understood. Objectives: The objectives of this prospective, observational study were to describe the spatiotemporal gas flow, aeration, and ventilation patterns within the lung in term neonates undergoing successful respiratory transition. Methods: Electrical impedance tomography was used to image intrathoracic volume patterns for every breath until 6 minutes from birth in neonates born by elective cesearean section and not needing resuscitation. Breaths were classified by video data, and measures of lung aeration, tidal flow conditions, and intrathoracic volume distribution calculated for each inflation. Measurements and Main Results: A total of 1,401 breaths from 17 neonates met all eligibility and data analysis criteria. Stable FRC was obtained by median (interquartile range) 43 (21-77) breaths. Breathing patterns changed from predominantly crying (80.9% first min) to tidal breathing (65.3% sixth min). From birth, tidal ventilation was not uniform within the lung, favoring the right and nondependent regions; P < 0.001 versus left and dependent regions (mixed-effects model). Initial crying created a unique volumetric pattern with delayed midexpiratory gas flow associated with intrathoracic volume redistribution (pendelluft flow) within the lung. This preserved FRC, especially within the dorsal and right regions. Conclusions: The commencement of air breathing at birth generates unique flow and volume states associated with marked spatiotemporal ventilation inhomogeneity not seen elsewhere in respiratory physiology. At birth, neonates innately brake expiratory flow to defend FRC gains and redistribute gas to less aerated regions.

Synchronized Inflations Generate Greater Gravity-Dependent Lung Ventilation in Neonates.

OBJECTIVE: To describe the regional distribution patterns of tidal ventilation within the lung during mechanical ventilation that is synchronous or asynchronous with an infant's own breathing effort. STUDY DESIGN: Intubated infants receiving synchronized mechanical ventilation at The Royal Children's Hospital neonatal intensive care unit were studied. During four 10-minute periods of routine care, regional distribution of tidal volume (VT; electrical impedance tomography), delivered pressure, and airway flow (Florian Respiratory Monitor) were measured for every inflation. Post hoc, each inflation was then classified as synchronous or asynchronous from video data of the ventilator screen, and the distribution of absolute VT and delivered ventilation characteristics determined. RESULTS: In total, 2749 inflations (2462 synchronous) were analyzed in 19 infants; mean (SD) age 28 (30) days, gestational age 35 (5) weeks. Synchronous inflations were associated with a shorter respiratory cycle (P = .004) and more homogenous VT (center of ventilation) along the right (0%) to left (100%) lung plane; 45.3 (8.6)% vs 48.8 (9.4)% (uniform ventilation 46%). The gravity-dependent center of ventilation was a mean (95% CI) 2.1 (-0.5, 4.6)% toward the dependent lung during synchronous inflations. Tidal ventilation relative to anatomical lung size was more homogenous during synchronized inflations in the dependent lung. CONCLUSIONS: Synchronous mechanical ventilator lung inflations generate more gravity-dependent lung ventilation and more uniform right-to-left ventilation than asynchronous inflations.

Regional ventilation characteristics during non-invasive respiratory support in preterm infants.

OBJECTIVES: To determine the regional ventilation characteristics during non-invasive ventilation (NIV) in stable preterm infants. The secondary aim was to explore the relationship between indicators of ventilation homogeneity and other clinical measures of respiratory status. DESIGN: Prospective observational study. SETTING: Two tertiary neonatal intensive care units. PATIENTS: Forty stable preterm infants born <30 weeks of gestation receiving either continuous positive airway pressure (n=32) or high-flow nasal cannulae (n=8) at least 24 hours after extubation at time of study. INTERVENTIONS: Continuous electrical impedance tomography imaging of regional ventilation during 60 min of quiet breathing on clinician-determined non-invasive settings. MAIN OUTCOME MEASURES: Gravity-dependent and right-left centre of ventilation (CoV), percentage of whole lung tidal volume (VT) by lung region and percentage of lung unventilated were determined for 120 artefact-free breaths/infant (4770 breaths included). Oxygen saturation, heart and respiratory rates were also measured. RESULTS: Ventilation was greater in the right lung (mean 69.1 (SD 14.9)%) total VT and the gravity-non-dependent (ND) lung; ideal-actual CoV 1.4 (4.5)%. The central third of the lung received the most VT, followed by the non-dependent and dependent regions (p<0.0001 repeated-measure analysis of variance). Ventilation inhomogeneity was associated with worse peripheral capillary oxygen saturation (SpO2)/fraction of inspired oxygen (FiO2) (p=0.031, r2 0.12; linear regression). In those infants that later developed bronchopulmonary dysplasia (n=25), SpO2/FiO2 was worse and non-dependent ventilation inhomogeneity was greater than in those that did not (both p<0.05, t-test Welch correction). CONCLUSIONS: There is high breath-by-breath variability in regional ventilation patterns during NIV in preterm infants. Ventilation favoured the ND lung, with ventilation inhomogeneity associated with worse oxygenation.

Transmission of Oscillatory Volumes into the Preterm Lung during Noninvasive High-Frequency Ventilation.

Rationale: There is increasing evidence for a clinical benefit of noninvasive high-frequency oscillatory ventilation (nHFOV) in preterm infants. However, it is still unknown whether the generated oscillations are effectively transmitted to the alveoli.Objectives: To assess magnitude and regional distribution of oscillatory volumes (VOsc) at the lung level.Methods: In 30 prone preterm infants enrolled in a randomized crossover trial comparing nHFOV with nasal continuous positive airway pressure, electrical impedance tomography recordings were performed. During nHFOV, the smallest amplitude to achieve visible chest wall vibration was used, and the frequency was set at 8 hertz.Measurements and Main Results: Thirty consecutive breaths during artifact-free tidal ventilation were extracted for each of the 228 electrical impedance tomography recordings. After application of corresponding frequency filters, Vt and VOsc were calculated. There was a signal at 8 and 16 Hz during nHFOV, which was not detectable during nasal continuous positive airway pressure, corresponding to the set oscillatory frequency and its second harmonic. During nHFOV, the mean (SD) VOsc/Vt ratio was 0.20 (0.13). Oscillations were more likely to be transmitted to the non-gravity-dependent (mean difference [95% confidence interval], 0.041 [0.025-0.058]; P < 0.001) and right-sided lung (mean difference [95% confidence interval], 0.040 [0.019-0.061]; P < 0.001) when compared with spontaneous Vt.Conclusions: In preterm infants, VOsc during nHFOV are transmitted to the lung. Compared with the regional distribution of tidal breaths, oscillations preferentially reach the right and non-gravity-dependent lung. These data increase our understanding of the physiological processes underpinning nHFOV and may lead to further refinement of this novel technique.

Cantaloupe Facilitates Salmonella Typhimurium Survival Within and Transmission Among Adult House Flies (Musca domestica L.).

Salmonella enterica serovar Typhimurium is a pathogen harbored by livestock and shed in their feces, which serves as an acquisition source for adult house flies. This study used a green fluorescent protein (GFP) expressing strain of Salmonella Typhimurium to assess its acquisition by and survival within house flies, and transmission from and between flies in the presence or absence of cantaloupe. Female house flies were exposed to manure inoculated with either sterile phosphate-buffered saline or GFP-Salmonella Typhimurium for 12 h, then used in four experiments each performed over 24 h. Experiment 1 assessed the survival of GFP-Salmonella Typhimurium within inoculated flies. Experiment 2 determined transmission of GFP-Salmonella Typhimurium from inoculated flies to cantaloupe. Experiment 3 assessed fly acquisition of GFP-Salmonella Typhimurium from inoculated cantaloupe. Experiment 4 evaluated transmission of GFP-Salmonella Typhimurium between inoculated flies and uninoculated flies in the presence and absence of cantaloupe. GFP-Salmonella Typhimurium survived in inoculated flies but bacterial abundance decreased between 0 and 6 h without cantaloupe present and between 0 and 6 h and 6 and 24 h with cantaloupe present. Uninoculated flies acquired GFP-Salmonella Typhimurium from inoculated cantaloupe and bacterial abundance increased in cantaloupe and flies from 6 to 24 h. More uninoculated flies exposed to inoculated flies acquired GFP-Salmonella Typhimurium when cantaloupe was present than when absent. We infer that the presence of a shared food source facilitated the transfer of GFP-Salmonella Typhimurium from inoculated to uninoculated flies. Our study demonstrated that house flies acquired, harbored, and excreted viable GFP-Salmonella Typhimurium and transferred bacteria to food and each other. Understanding the dynamics of bacterial acquisition and transmission of bacteria between flies and food helps in assessing the risk flies pose to food safety and human health.

Patterns of food parenting practices regarding junk food and sugary drinks among parent-child dyads.

BACKGROUND: Children's food preference and intake patterns are affected by parental child feeding practices. The objective was to determine patterns of food parenting practices regarding junk food and sugary drinks (JS) and investigate their associations with demographic characteristics and dietary intake in a large cohort of parents and their children (12-17 years). METHODS: Dyadic survey data from the cross-sectional, internet-based Family Life, Activity, Sun, Health, and Eating Study, conducted in 2014, were analyzed using latent class analysis to identify patterns of use for six JS parenting practices - negative emotions, restriction, monitoring, availability, modeling, and child involvement - based on parent and child report. Model covariates included self-reported parent and child sex, age (child only), body mass index category (based on height and weight), added sugars intake, and legitimacy of parental authority. RESULTS: Based on 1657 parent-child dyads, five parenting practice patterns were identified representing different levels of practice use - Complete Influencers (28%; reference class), Indifferent Influencers (21%), Negative Influencers (20%), Minimal Influencers (18%), and Disagreeing Influencers (13%). Compared to older child dyads, younger child dyads were less likely to belong to Indifferent and Minimal Influencers (79 and 63% lower odds, respectively). Greater parent added sugars intake increased the odds of belonging to Indifferent and Negative Influencers (4 and 5% higher for every teaspoon increase, respectively) while greater child added sugars intake decreased the odds of belonging to Minimal Influencers (6% lower for every teaspoon increase). Compared to dyads with high scores, dyads with low child scores for legitimacy of parental authority regarding JS were 18 times as likely to belong to Disagreeing Influencers. CONCLUSIONS: The study findings suggest that parents utilize distinct patterns of feeding practices regarding JS ranging from use of many practices, use of some practices, to low use of any practice, with differential associations with parent and child intakes of added sugars. Counseling or intervening with parents to use a mix of structure practices, such as availability and modeling, to positively influence their child's and possibly their own intake of sugary snacks and drinks may prove more efficacious than use of coercive control practices, such as negative emotions.