Feeding Method Research Articles

Influence of breastfeeding on the ontogenesis of mucosal immunity in children

The role of breastfeeding in the development of the cellular immune system, antimicrobial strategies of neutrophils, and local cytokine levels was evaluated in a single-center, prospective, open-label, uncontrolled study of healthy infants who were either naturally or artificially breastfed. The main group included practically healthy children who were exclusively breastfed for the first year of life. Thirty-six children were examined during the first stage and 25 from this group during the second stage. The comparison group included children who received an adapted cow’s milk formula during the first half-year of their lives and a different formula during the second half-year. Thirty-one children were examined during stage one and 27 from this group were examined during stage two. A comprehensive study of mucosal immunity was conducted, assessing the cytokine profile and cellular components using the method of smear prints from the nasal mucosa. The results showed that the nature of feeding during the first year of life influences the formation of mucosal immunity and programming the postnatal development of the child’s immunological reactivity. In the absence of the immunomodulatory effects of breast milk, there is an imbalance in the cytokine profile, with a physiological deviation of the immune response linked to the predominance of Th2 profiles. In contrast, breastfeeding promotes the optimal cellular composition of the upper respiratory mucosa and a cytomorphological neutrophil profile with minimal destructive changes. Breastfeeding programs the optimal functional profile of neutrophils, including the level of receptor activity, intracellular biocidal activity, cytotoxicity, ability to complete phagocytosis. This natural infant feeding method has a long-term protective effect, preventing neutrophil destruction under the influence of environmental factors and respiratory viral agents, and ensuring optimal mucosal immunity development in the respiratory tract.

Breastfeeding and Children's Cognitive Development up to the Age of 4 Years: The Japan Environment and Children's Study.

Objective: Breastfeeding, depending on its duration, has been suggested to benefit children's cognitive development. We aimed to examine this issue by using the Japan Environment and Children's Study, a nationwide prospective birth cohort study. Methods: We evaluated the relationship between feeding methods and cognitive development in 2- and 4-year-old children. We classified the children based on the following feeding method during the first 6 months postpartum: (1) exclusive breastfeeding group, solely breastfeeding; (2) partial breastfeeding group, solely breastfeeding for ≤5 months and combination of breastfeeding/formula for the rest of months; (3) formula-fed group, solely formula feeding for ≥4 months; and (4) others. Cognitive development was assessed by trained testers using the Kyoto Scale of Psychological Development 2001. Results: Data on 1,329 boys and 1,398 girls were analyzed. Multiple regression analysis was performed using the exclusive breastfeeding group as the reference. Boys of age 2 years in the formula-fed group had significantly lower developmental quotients (DQs) in the language-social developmental (L-S) area (partial regression coefficient [B]: -4.624, p = 0.01), whereas no significant difference was observed in those of age 4 years. Girls of age 2 and 4 years in the formula-fed group had significantly lower L-S area DQ (B: -3.637, p = 0.03 and B: -3.414, p = 0.03, respectively). In the partial breastfeeding group, no significant differences in the L-S area DQ were observed in 2- and 4-year-old boys and girls. Conclusions: Exclusive breastfeeding for the first 6 months postpartum may be more beneficial for verbal cognitive development in 4-year-old girls than solely formula feeding for ≥4 months. Furthermore, breastfeeding combined with formula for the first 6 months postpartum may not have a disadvantage on cognitive development in boys and girls of age ≥ 2 years, when compared with that observed with exclusive breastfeeding during the first 6 months postpartum.

PRÁTICAS DE ENSINO EM SALA DE AULA: IMPACTO DAS ATIVIDADES INTERATIVAS NO APRENDIZADO DE BIOLOGIA

This article investigates the impact of interactive activities proposed in the classroom on the biology learning of integrated high school students at the IFMT Várzea Grande campus. The methodology involved direct and indirect participant observation, with the aim of describing the behavior, feeding methods, reproduction and interactions of animals observed in the backyard of these students' homes. The results indicated an increase in engagement and understanding of the concepts studied in the classroom and that the backyard environment proved to be its own small ecosystem, adapted to the conditions and species that live there.

Mothers Falling Asleep During Infant Feeding.

Falling asleep while feeding (FAF) infants is common. Our primary objectives were to examine (1) maternally reported prevalence of FAF and if planned; (2) association between FAF and sociodemographic factors, feeding method, and sleep location; and (3) if receipt of education about safe sleep and bedsharing risks was associated with FAF. In the Social Media and Risk-reduction Training study, US mothers of newborns were randomized to educational messaging promoting infant safe sleep or breastfeeding. We analyzed data from 1259 mothers who responded to the postpartum survey (mean infant age, 11.2 weeks). We used generalized estimating equation logistic regression models to examine the extent that sociodemographic characteristics, feeding type, usual nighttime feeding location, and intervention group were associated with FAF. A total of 28.2% of mothers reported FAF usually or sometimes in the last 2 weeks, 83.4% of whom reported that FAF was unplanned. There were no differences in the odds of FAF by sociodemographic factors. Compared with mothers whose nighttime feeding location was their bed, mothers who reported feeding in a chair were less likely to FAF (33.6% versus 16.8%; adjusted odds ratio, 0.41; 95% confidence interval, 0.31-0.56). FAF was reported less frequently by mothers who received safe sleep interventions (15.6%), compared with mothers who received breastfeeding interventions (33.0%; adjusted odds ratio, 0.40; 95% confidence interval, 0.25-0.65). FAF is reported commonly among US mothers and is predominantly unplanned. Mothers who received safe sleep messaging were less likely to report FAF. New parents need guidance on planning for optimal safety during infant feeding.

Effect of different tube feeding methods on gastroesophageal reflux features in preterm infants: a pH-impedance monitoring study.

Continuous feeding and boluses may have a different impact on pH-MII GER features in symptomatic tube-fed preterm infants, whereas the permanence of the feeding tube across LES did not seem to worsen GER indexes. • Due to the functional and anatomical immaturity of the gastrointestinal tract, gastroesophageal reflux (GER) is common in preterm infants. • A stepwise therapeutical approach which firstly undertakes conservative strategies is the most advisable choice to avoid potentially harmful pharmacological overtreatments in the preterm population. • Continuous feeding and boluses may have a different impact on GER features assessed by pH-MII monitoring in tube-fed preterm infants. • The permanence of the feeding tube during or after the feeding period did not seem to worsen GER occurrence. • By reducing GER features, especially acid GER, continuous feeding may potentially contribute to limit the need for antiacid medications in this population.

Association between infant feeding behavior and maternal choice of breastfeeding type

Abstract Introduction Feeding in infants is a fundamental process influenced by the mother-child relationship during the early months of life. The regulation of feeding behavior, and hunger and satiety cues may be interpreted by the mother, potentially relating to the type of feeding chosen. Objectives To determine the association between infant feeding behavior and the type of breastfeeding chosen by the mother. Methods A cross-sectional and prospective study was conducted, including mothers with children aged between 6 and 18 months. Those with medical contraindications for immediate postpartum breastfeeding or with suspension of exclusive breastfeeding during the first 6 months of life due to medical prescription were excluded. The Baby Eating Behavior Questionnaire was used to evaluate the baby’s enjoyment of food, appetite response, eating speed, and satiety response. Results 108 mothers were included, with 87% in agreement with exclusive breastfeeding (EBF), 43.3% using breastfeeding as the primary feeding method, and only 33.3% practicing EBF during the first 6 months. Food response (FR) scored 19.6 (±4.3), enjoyment of food (EF) 17.6 (±2.1), satiety response (SR) 7.1 (±2.0), eating speed (ES) 8.8 (±2.3), and appetite (AP) 4.2 (±0.7). Comparing FR, EF, SR, ES, and AP scores between those who practiced EBF and those who did not showed p > 0.05. sociodemographic characteristics, perinatal factors, stance on EBF, number of hours per day with the child, feeding location, poor technique, breastfeeding pain and lack of medical guidance, all showed p > 0.05 when comparing between those who practiced EBF and those who did not; in contrast to perceiving that the baby wanted to breastfeed (2.5/1.0-6.2), having time to feed (3/1.2-7.2) and having no health problems (10/1.2-78.7) all with p-value <0.05. Conclusions The mother’s perception identifying the baby’s desire to breastfeed, having time to feed the baby and not having health problems favor exclusive breastfeeding. Key messages • Maternal perception plays an important role in deciding to give SCI, so it is the physician’s job to educate the mother so that she has additional arguments for choosing SCI. • The infant’s feeding behavior does not have a significant impact on the mother’s behavior in choosing SCI feeding.

Hybrid additive manufacturing of ceramic/aluminum-titanium gradient composites via arc and laser cladding eutectic pools

ABSTRACT There is a great deal of interest in improving the efficiency of arc-directed energy deposition (Arc-DED) of aluminium matrix composites and the uniform introduction of reinforcing particles. In this work, ceramic/aluminum-titanium gradient composites were manufactured by hybrid additive manufacturing with arc and laser cladding eutectic pools. The results show that the laser cladding powder feed method can have a higher powder capture rate compared to bypass feeding. Coupling the laser and powder changed the pulsed base-arc characteristics and increased the peak arc length. After the addition of the powder mixture, the aluminium matrix formed an Al3Ti reinforced phase, which evolved from needles to rods as the amount of powder increased. As the content of ceramic particles and the Al3Ti phase increased, the average hardness of the AMC components increased from 55.5–126 HV0.1 and the wear rate decreased from 6.16 × 10−3–1.25 × 10.−3 mm3·N−1·m−1.

Percutaneous endoscopic gastrostomy helped to normalise feeding problems and gastrointestinal symptoms in Silver-Russell syndrome.

This study evaluated feeding problems and gastrointestinal symptoms in children with Silver-Russell syndrome (SRS), which is a rare epigenetic disorder. It also compared the symptoms experienced during different feeding methods, including percutaneous endoscopic gastrostomy (PEG). The national expert team for children with SRS at Queen Silvia Children's Hospital, Gothenburg, studied 46 referrals (63% male) who were born with SRS in Sweden from 1984 to 2018. Patient data were extracted from the Paediatric National Growth Hormone Registry. The medical records covered a median of 68% of the time of the patients' childhood, with a median follow-up of 9 years. Their symptoms were most prevalent during infancy and decreased when they were toddlers. Feeding problems and gastrointestinal symptoms were reported in 91% of the 46 patients, with vomiting in 57% and constipation in 46%. There were 19 children who relied on enteral feeding for their nutrition and 13 of those received PEG. Their body mass index (BMI) increased significantly 2 years after PEG started (p = 0.005). Feeding problems and gastrointestinal symptoms were very common in children with SRS, but partly disappeared during childhood. Providing treatment, such as PEG, normalised the BMIs of children with SRS and reduced their symptoms.

Development of gross motor skills in children under the age of 3 years: a decision tree approach.

The early years of life are critical for gross motor development (GMD). This study utilized decision tree modeling to examine the influences on gross motor development in children under the age of 3 years and to rank the key factors affecting their development. Based on randomized stratified sampling, 9,507 children aged 0-3 years in Shenzhen were included in this study. The Ages and Stages Questionnaires (ASQ) were utilized for the assessment of gross motor development. The chi-square test was used to compare groups, and variables were screened using univariable and multivariable regression analyses. Decision tree modeling was employed to rank the importance of statistically significant variables. The research found a prevalence of gross motor developmental delay of 1.41% among the respondents. The accuracy of the decision tree model is 70.96%. The results demonstrated a strong correlation between seven variables affecting the gross motor development of children, which were ranked based on importance: age, whether to provide supplementary food, average time spent interacting with children, family type, feeding method, mode of delivery, and birth order. The risk of gross motor developmental delay increases with age. Furthermore, supplementary food and interacting with other children are critical factors in improving children's GMD delay. It is therefore imperative to enhance the monitoring of children's gross motor skills through regular developmental assessments that detect potential GMD delays. Moreover, family type, feeding method, mode of delivery, and birth order were also predictive factors of GMD delay.

Positive Deviance in Nutritional Practices for Two-Year-Olds in Poor Fisherman Families in the Belawan Health Center Area, 2022

The problem of malnutrition is still the main problem faced in human resource development. The problem of growth and development of Baduta is a serious problem because at this age the process of physical and intellectual growth and development is critical. Malnutrition problems mostly occur in poor families but are not caused by poor families who have well-nourished children. The Belawan Community Health Center working area is one of the community health centers with the highest number of cases of malnutrition in Medan City. To overcome this, a program is needed that is believed to be effective and sustainable. One of the existing programs to overcome the problem of malnutrition and malnutrition is positive deviation. This research aims to identify positive behavior in feeding (type of food, processing of food ingredients, mealtimes and method of feeding) of toddlers who are well-nourished in poor fishing families in the Belawan Community Health Center Working Area in 2022. This research method is qualitative research with a narrative approach. Researchers studied individual lives by asking one or several individuals to tell stories about their lives related to positive behavior in feeding well-nourished animals. This information is then retold by the researcher in a narrative chronology. The findings of this research indicate that addressing nutritional challenges in children can be effectively achieved by leveraging the potential and resources within the community. This is done through the identification of positive deviant behaviors, particularly those related to beneficial feeding practices. These practices encompass aspects such as the types of food provided, the methods of food preparation, the timing of meals, and the approach to food administration. Keep up the great work! The way you’re thinking about integrating community strengths is spot-on for creating sustainable solutions.

Evaluating the Effect of Maggot Flour Protein as a Substitute for Fishmeal on the Growth Performance and Survival Rate of Common Carp (Cyprinus carpio)

This research aims to know the role of maggot flour protein as a fishmeal protein source replacement on growth performance and survival of common carp (Cyprinus carpio) and the optimum dose from artificial maggot flour feed. This research take a place at Aquaculture Laboratorium of Diponegoro University in 23 January – 6 March 2023. The experimental method using complete randomized design (RAL) consisting of 4 treatments 3 repetitions. The treatment is applied with percentage maggot flour substitution 0%, 10%, 20%, and 30% per gram of feed. The substitution set according to carp protein sufficient (30 – 35%), so that carp does not having excess protein that can effect on growth performance. The test fish used was common carp with an average size of 4.54 ± 0.23 cm with an average weight of 0.75 ± 0.03 gr/head. The experimental containers using a aquarium tank with size of 45cm x 30cm x 22.5cm. Stocking density per aquarium is 0.5 fish/liter with a maintenance period of 42 days. The experimental using feeding methods 5% of biomass with a frequency 3 times/day. The experimental results showing that substitution of artificial maggot flour feed for common carp is significantly influential (P<0.05) on specific growth rate (SGR), feed conversion ratio (FCR), and survival rate (SR) of common carp. Based on experimental, the best dose substitution artificial maggot flour feed has been shown in treatments C (20%) and D (30%). Treatment C produced SGR 1.93 ± 0.04 and FCR 2.41 ± 0.07 and treatment D produced SGR 1.97 ± 0.09% and FCR 2.34 ± 0.12. The results of observations during the research showed that common carp fed with the experimental feed (substitution of maggot flour for artificial feed 0%, 10%, 20%, 30%) had a high survival rate with an average survival rate above 90%.

In silico screening of dyes for enhanced silk coloring using the feeding approach

Reducing redundant dyes in the production of colored silk is essential for environmental sustainability. This study aims to innovate silk dyeing processes by employing molecular docking techniques to screen a library of dyes with specific physical properties. For the first time, we identified Acid Blue 25 (Chemical Identifier, CID 22916) and Metanil Yellow (CID 11490) as cost-effective blue and yellow dyes, respectively, that enable the production of intrinsically colored silk by feeding dye-modified mulberry leaves to silkworms. Both dyes demonstrated high selective binding to silk fibroin and retained excellent color performance after degumming. Secondary structural analysis revealed that Acid Blue 25 enhanced mechanical properties by increasing β-sheet content, whereas Metanil Yellow did not. Furthermore, fluorescence spectroscopy indicated that Acid Blue 25 and Metanil Yellow effectively quenched the intrinsic fluorescence of silk fibroin primarily through static quenching, with Acid Blue 25 exhibiting a higher binding constant and more negative binding free energy. Classic molecular dynamic (cMD) simulations revealed that the extensive interaction network of Acid Blue 25, compared to Metanil Yellow, creates a thermodynamically favorable environment for dye-complex binding and stability. Overall, the combined application of virtual screening and the feeding method supports a highly cost-effective and environmentally friendly silk dyeing strategy, with the potential for scaling up in industrial applications.

Design of A Rectangular Patch Microstrip Array Antenna with Proximity Coupled On ADS-B Receiver

One of the observation facilities available in Indonesia was Automatic Dependent Surveillance-Broadcast (ADS-B), a surveillance technology similar to Radio Detection and Ranging for monitoring air traffic. This system only received information transmissions from aircraft, broadcast on a frequency of 1090 MHz using a monopole antenna with large dimensions, ranging from 85 centimeters to 3,5 meters, and weighing between 1,5 kilograms to 26 kilograms. As an alternative, a microstrip antenna was chosen to reduce the large size and weight of the monopole antenna. This research aimed to design a 2x1 rectangular patch microstrip array antenna with a proximity coupled feeding method at a frequency of 1090 MHz. The antenna was designed using Antenna Design Software and fabricated using Epoxy substrate material with a copper ground plane. The simulation results showed a Return Loss of -28,87 decibels, VSWR 1,07, Bandwidth 28,87 MHz, Impedance 52,4 Ω, and Gain 8,49 decibels. The measurement results showed a Return Loss of -30,87 decibels, VSWR 1,07, Bandwidth 28 MHz, Impedance 48,91 Ω, and Gain 6,4 decibels. The test results demonstrated that the antenna successfully received signals from 32 aircraft, with the longest reception distance reaching 172,5 Nautical Miles (319.4 kilometer) at a maximum altitude of 36,950 feet.

Chronic oral toxicity protocol for adult solitary bees (Osmia bicornis L.): Reduced survival under long-term exposure to a “bee-safe” insecticide

Pollinators are essential for crop productivity. Yet, in agricultural areas, they may be threatened by pesticide exposure. Current pesticide risk assessments predominantly focus on honey bees, with a lack of standardized protocols for solitary bees. This study addresses this gap by developing a long-term oral exposure protocol tailored for O. bicornis. We conducted initial trials to determine optimal container sizes and feeding methods, ensuring high survival rates and accurate syrup consumption measurements. A validation test involving five laboratories was then conducted with the insecticide Flupyradifurone (FPF). Control mortality thresholds were set at ≤ 15% at 10 days. Three laboratories achieved ≤10%, demonstrating the protocol's effectiveness in maintaining healthy test populations. The seasonal timing of experiments influenced control mortality, underscoring the importance of aligning tests with the natural flight period of the population used. Our findings revealed dose-dependent effects of FPF on syrup consumption, showing stimulatory effects at lower concentrations and inhibitory effects at higher ones. The 10-day median lethal daily dose (LDD50) of FPF for O. bicornis (531.92 ng/bee/day) was 3.4-fold lower than that reported for Apis mellifera (1830 ng/bee/day), indicating Osmia's higher susceptibility. Unlike other insecticides, FPF did not exhibit time-reinforced toxicity. This study introduces a robust protocol for chronic pesticide exposure in solitary bees, addressing a critical gap in current risk assessment. Based on its low risk to honey bees and bumblebees, FPF is approved for application during flowering. However, our results suggest that it may threaten Osmia populations under realistic field conditions. Our findings underscore the need for comparative toxicity studies to ensure comprehensive protection of all pollinators and the importance of accounting for long term exposure scenarios in risk assessment. By enhancing our understanding of chronic pesticide effects in solitary bees, our study should contribute to the development of more effective conservation strategies and sustainable agricultural practices.

Differential circRNA Screening and Identification of Subcutaneous Fat Tissue in Plateau-type Yaks under Different Feeding Methods

Background: In order to explore the differential expression of circular RNA (circRNA) in the subcutaneous fat tissue of Qinghai yaks under different feeding methods during the dry grass period and its regulatory mechanism. Methods: The present study adopted Illumina sequencing technology to sequence the transcriptome of subcutaneous fat tissue of Qinghai yaks naturally grazed and fattened by housed feeding during the dry grass period and used bioinformatics software to screen out the differentially expressed. The circRNAs were screened for differential expression using bioinformatics software. circRNAs related to fat metabolism were screened by GO function and KEGG pathway enrichment analysis of their source genes and three differentially expressed circRNAs were randomly screened and the expression of the circRNAs was verified by real-time fluorescence quantitative PCR (qRT-PCR). Result: Transcriptome sequencing results showed that a total of 628 differentially expressed circRNAs were obtained, of which 219 were up-regulated and 409 were down-regulated. GO functional enrichment analysis showed that the circRNAs in the free-grazing group originated from genes for major molecular constructs, cellular parts, organs, bioregulation and cellular processes, etc. KEGG pathway enrichment analysis showed that the circRNAs could be participate in signaling pathways such as phagosomes, protein digestion and absorption. qRT-PCR results showed that the expression levels of the three circRNAs were consistent with the sequencing results and the sequencing results were accurate and reliable. This experiment provides a molecular basis for further understanding of fat metabolism in yaks.

Residual transmission of HIV infection from mother to child in the Atlantic and littoral departments in Benin

BackgroundThe implementation of the WHO’s 2015 recommendations in Benin, requires an assessment of the progress made over time in preventing the transmission of the infection to exposed-infants, and the identification of its determinants.MethodsThis was a retrospective study of HIV-1 exposed-infants who underwent PCR between the 6th and 8th weeks of life. Early diagnostic tests were performed using the Abbott m2000 RealTime platform. Comparison of proportions tests (analysis of the significance of the difference in prevalence) with an error threshold of 5% were used to assess the determinants of the transmission. Statistical analysis was performed using R statistical software, version 4.1.3.0.ResultsA total of 5,312 infants benefited from early diagnosis by PCR between 2016 and 2021. Among them, 52% are males, tritherapy before pregnancy was the majority treatment used by mothers (30.6%) and monotherapy that of newborns (70%). Mixed breastfeeding is the feeding method with the highest prevalence. The overall transmission rate was 3.4% over the six years. The highest prevalence was achieved in 2018 (4.2%) and the lowest in 2021 (2.7%). The prevalence was lower when mothers were on tritherapy before pregnancy. The determinants of transmission were: mixed breastfeeding, lack of treatment in mothers (22.4%), lack of treatment in infants (19.7%), undefined treatments or absence of treatment in the mother-child pair.ConclusionThis study shows the contribution over time of the PMTCT program to reducing HIV transmission among exposed-infants and also underlines the need for proper conduct of treatment in any women of childbearing age.

Genotype distribution and allele frequency of thioester-containing protein 1(Tep1) and its effect on development of Plasmodium oocyst in populations of Anopheles arabiensis in Ethiopia.

Thioester-containing protein 1 (TEP1) is a crucial component of mosquitoes' natural resistance to parasites. To effectively combat malaria, there is a need to better understand how TEP1 polymorphism affects phenotypic traits during infections. Therefore, the purpose of this study was to determine the Tep1 genotype frequency in malaria vector populations from south-western Ethiopia and investigate its effect on Plasmodium oocyst development in Anopheles arabiensis populations. Using standard dippers, Anopheles mosquito larvae were collected from aquatic habitats in Asendabo, Arjo Dedessa, and Gambella in 2019 and 2020. Collected larvae were reared to adults and identified morphologically. Female An. gambiae s.l. were allowed to feed on infected blood containing the same number of gametocytes obtained from P. falciparum and P. vivax gametocyte-positive individuals using indirect membrane feeding methods. Polymerase Chain Reaction (PCR) was used to identify An. gambiae s.l. sibling species. Three hundred thirty An. gambiae s.l. were genotyped using Restricted Fragment Length Polymorphism (RFLP) PCR and sub samples were sequenced to validate the TEP1 genotyping. Among the 330 samples genotyped, two TEP1 alleles, TEP1*S1 (82% frequency) and TEP1*R1 (18% frequency), were identified. Three equivalent genotypes, TEP1*S1/S1, TEP1*R1/R1, and TEP1*S1/R1, had mean frequencies of 65.15%, 2.12%, and 32.73%, respectively. The nucleotide diversity was ranging from 0.36554 to 0. 46751 while haplotype diversity ranged from 0.48871 to 0.63161, across all loci. All sample sites had positive Tajima's D and Fu's Fs values. There was a significant difference in the TEP1 allele frequency and genotype frequency among mosquito populations (p < 0.05), except populations of Anopheles arabiensis from Asendabo and Gambella (p > 0.05). In addition, mosquitoes with the TEP1 *RR genotype were susceptible and produced fewer Plasmodium oocysts than mosquitoes with the TEP1 *SR and TEP1 *SS genotypes. The alleles identified in populations of An. arabiensis were TEP1*R1 and TEP1*S1. There was no significant variation in TEP1*R1 allele frequency between the high and low transmission areas. Furthermore, An. arabiensis carrying the TEP1*R1 allele was susceptible to Plasmodium infection. Further studies on vector-parasite interactions, particularly on the TEP1 gene, are required for vector control techniques.

8548 Breast Development in Infant Girls: Does Endogenous Estrogen Production During Minipuberty Play a Role?

Abstract Disclosure: M. Goldberg: None. S. Zhao: None. A. Kelly: None. V.A. Stallings: None. D.M. Umbach: None. W.J. Rogan: None. N. Shaw: None. D.P. Sandler: None. Background: Breast tissue, present at birth in most term infants, regresses during infancy but persists longer in girls than boys. In girls, this persistence is thought to be due in part to stimulation by estradiol (E2) produced during minipuberty, the postnatal activation of the hypothalamic-pituitary-gonadal axis. Empirical data are sparse, however. Because E2 concentrations in infant girls fluctuate, repeated E2 measures may be necessary to adequately characterize production across minipuberty and to detect effects on estrogen-sensitive breast tissue. Hypothesis: Higher average exposure to E2 during minipuberty is associated with larger breast bud diameter in late infancy in term females. Methods: We leveraged data from 136 girls from the Infant Feeding and Early Development (IFED) Study, a prospective cohort of reproductive development in term infants enrolled during 2010-2013 from the Philadelphia area. We measured E2 in serum samples collected at study visits every 2-4 weeks from age 2-32 weeks. We assessed breast bud diameter via ultrasound at the 32-week visit. For data analysis, we log2-transformed both E2 and breast bud diameter. For E2 concentrations below the limit of detection (2.99 pg/mL, 35% of samples), we applied multiple imputation. We first calculated the intraclass correlation coefficient (ICC) of repeated E2 to understand the relative magnitude of total variation from within subjects. We then calculated subject-specific mean of E2 across time and estimated associations with breast bud diameter at the 32-week visit using both age- and multivariable-adjusted linear regression models. We present results as percent change in breast bud diameter per doubling in average E2 concentration ([2β-1] x 100%). Results: Most infants were Black (71%) and formula-fed (76%). The median number of E2 measures per girl was 9 (range: 5-10). Most of the variation in E2 concentrations was due to within-individual variation (ICC=0.27). The geometric mean E2 concentration from 2-32 weeks of age was 5.1 pg/mL (95% confidence interval [CI]: 4.7-5.4). The median breast bud diameter at the 32-week visit was 13.7mm (range: 4.4-30.5). A doubling in average E2 concentration across minipuberty was associated with a 26% larger breast bud diameter (95% CI 10-43%). This association was similar after adjustment for feeding method, race, gestational age, neonatal weight, and breast bud diameter at the neonatal visit (percent change: 28%, 95% CI: 12-46%). Conclusions: Our results suggest that endogenous estrogen production in females during minipuberty stimulates the infant breast bud. More research is needed to investigate the potential biologic relevance of this hormonal stimulation of infant breast tissue to later breast development and risk of malignant and benign breast disorders. Presentation: 6/1/2024

Simulation Research on the Control Method of Bow-Collapse in Gear Cold Roll-Beating

Bow-collapse is a type of geometric defect in the gear cold roll-beating process. In order to effectively control bow-collapse and improve material utilization, this paper calculates the cross-section radius of the blank according to the volume invariance principle of metal plastic deformation, and then performs FE simulation of the cold roll-beating process by using the cyclic beating of adjacent tooth spaces and intermittent blank feeding method. The flow state of metal particles is investigated, revealing that the movement of metal particles along the axial direction of the blank is the main reason for the formation of bow-collapse. This paper proposes a method to correct the cross-section radius of the blank and thus control for bow-collapse, where the loss coefficient K characterizes the state of metal particle loss in an infinitesimal thickness region on the cross-section. The analytical equation for calculating the corrected value of the cross-section radius is derived, and the corrected value is calculated. Conducted on the modified blank, cold roll-beating FE simulation results show that bow-collapse is effectively controlled, and the loss coefficient K correctly reflects the loss state of metal particles on the cross-section. The simulation results also show that after cold roll-beating, the gear teeth with standard face width and tooth depth can be obtained after two turning end faces and turning tip circle processes. The bow-collapse control method proposed in this paper effectively improves material utilization.

Father support breastfeeding self-efficacy positively affects exclusive breastfeeding at 6 weeks postpartum and its influencing factors in Southeast China: a multi-centre, cross-sectional study

BackgroundThe exclusive breastfeeding condition in China is not optimism now. Maternal breastfeeding self-efficacy stands as a pivotal factor influencing exclusive breastfeeding. Interestingly, studies have suggested that father support breastfeeding self-efficacy is a pivotal mediator in infant breastfeeding. Thus, the current research aimed to investigate the association between father support breastfeeding self-efficacy and exclusive breastfeeding at six weeks postpartum, and the influencing factors of father support breastfeeding self-efficacy.MethodsThis research was structured as a multi-centre cross-sectional study, involving 328 fathers, whose partners were six weeks postpartum, and recruited from two public hospitals in Southeast China. Self-designed demographic questionnaires, namely, Father Support Breastfeeding Self-Efficacy Scale-Short Form, Breastfeeding Knowledge Questionnaire, Positive Affect Scale and the 14-item Fatigue Scale, were applied. Descriptive statistics, Chi-square test, logistic regression univariate analysis and multiple linear regression were used to analyse data.ResultsResults indicate a significant difference between the infant feeding methods at six weeks postpartum and fathers with different levels of support breastfeeding self-efficacy (p < 0.05). Particularly, father support breastfeeding self-efficacy positively affected exclusive breastfeeding at six weeks postpartum after adjusting all the demographic characteristics of fathers (OR: 2.407; 95% CI: 1.017–4.121). Moreover, results show that the significant influencing factors of father support breastfeeding self-efficacy include breastfeeding knowledge, fatigue, positive affect, successfully experienced helping mothers to breastfeed, spousal relationships and companionship time.ConclusionsHigh-level father support breastfeeding self-efficacy effectively increased exclusive breastfeeding rate at six weeks postpartum. To enhance the exclusive breastfeeding rate, nurses or midwives can endeavour to design educational programmes or take supportive interventions customised for fathers, such as enhancing their breastfeeding knowledge education, reducing fatigue and mobilising positive emotions, thereby bolstering paternal self-efficacy in breastfeeding.