Feeding Trajectories Research Articles

Breastfeeding trajectories for preterm infants over the first 6 months of life in England 2010–2020: surveys using large representative birth samples

BackgroundBreastmilk is the optimal source of nutrition for infants, particularly preterm infants. Preterm infants face unique feeding challenges and these change with the birth gestation of the infant. Preterm infants’...

Commercial milk formula marketing entry points: setting the course of infant and young child feeding trajectories

BackgroundThere is a limited understanding of the dynamic influences that shape infant and young child feeding (IYCF) decisions over time. We conducted an innovative qualitative study to reconstruct IYCF trajectories across early life course phases, in the context of the socioecological model (SEM) and the commercial determinants of IYCF.MethodsWomen of different socioeconomic status were interviewed in two large metropolitan areas in Mexico. Our specific goal was to allow us to better understand if and how the commercial milk formula (CMF) marketing influenced breastfeeding decisions in a complex dynamic way involving the individual, relational, community and societal levels.ResultsHospitals, health professionals, and interactions with social media were key category entry points throughout the prenatal, perinatal, early infancy period and beyond. The CMF industry interfered by engaging a wide array of actors across the different layers of the SEM, most prominently the health care system and the workplace. Through its marketing strategies the CMF operates subconsciously and its messages are most effective when health institutions, health care providers, workplace spaces and social norms are weak in their support for breastfeeding.ConclusionsThe cases in our study highlight how, together with a weak breastfeeding counseling system, and health professionals who lack training in breastfeeding and normal infant behavior, lead to the opportunity for CMF marketing to shape infant feeding, and ultimately to the decision to feed formulas that some mothers were not planning to use and cannot afford.

Correction method of servo feed trajectory in block divided EDM for diffusion shaped film cooling holes

Correction method of servo feed trajectory in block divided EDM for diffusion shaped film cooling holes

Oral feeding trajectories and neurodevelopmental outcomes at 12 and 24 month follow-up for preterm infants.

Few studies characterize feeding performance in the NICU when predicting neurodevelopmental outcomes. Our objective was to investigate the relationship between time to full oral feeds (FULL-PO) and neurodevelopmental and feeding outcomes in the first 2 years in preterm infants admitted to the NICU. This retrospective study included infants born between 01/01/2014-07/31/2017, gestational age < 32 weeks and/or birth weight < 1500 g. We examined feeding difficulties, cerebral palsy, and Bayley scores for those reaching FULL-PO at a post menstrual age (PMA)≤38.0 weeks (EARLY) vs.>38.0 weeks (LATE). Additionally, the oral feeding achieved at various timepoints between 36- and 42-weeks postmenstrual age (PMA) was measured to construct a timeline of oral feeding acquisition. Of 192 infants, 147(77%) achieved FULL-PO EARLY and 45(23%) LATE. Comorbidities and length of stay were higher and unadjusted Bayley scores were lower at 12 months corrected age (CA) and 24 months chronological age (CH) in the LATE group. Feeding difficulties were higher in the LATE group at 24 months CH. Infants born < 27-28 weeks GA were more likely to achieve oral feeding at a later PMA. Infants with bronchopulmonary dysplasia (BPD) had significant feeding and developmental delays. Establishing full oral feeds by 38.0 weeks PMA may be used as a predictor for feeding difficulties at 24 months CH. Infants born < 27-28 weeks GA and those with BPD are more likely to take extended amounts of time to achieve full oral feeding and need additional feeding support. Infants with BPD are high risk for neurodevelopmental delays.

Optimization of Feed Ration Size in Aquatic System According to the Optimal Control Approach: Implications of Using the von Bertalanffy Growth Model

Rationing aquaculture farming feed is challenging for producers due to high feed costs, representing 30%–60% of the total operating costs. Therefore, optimal timing of feeding could lead to improved economic returns from an aquatic system. An optimal dynamic feeding model has been determined considering the von Bertalanffy growth model. A bioeconomic model of tilapia production in Mexico for specific markets was used for numerical illustration. The von Bertalanffy growth model was parameterized with experimental data from tilapia (Oreochromis niloticus) fed four ration sizes (50%, 80%, 100%, and satiety), in order to determine different optimal rationing for different fish sizes (200, 300, and 400 g), market prices (Monterrey, Cancún, Mexico City, and On site), and optimal harvesting times (OHT), considering the time value of money. The results of the modeled optimal feeding trajectories show a continuous decrease from stocking to reach a minimum value and then slightly approaching the harvest size. This result contrasts with the recommendations of the feed suppliers and with those found when a potential growth model was used. The results in the case study showed that the Monterrey market presented the highest present value of the benefits in the OHT and the different market sizes. The implications of the Bertalanffy model for optimal rationing trajectories are presented in the discussion.

Dynamic Optimisation of Fed-Batch Bioreactors for mAbs: Sensitivity Analysis of Feed Nutrient Manipulation Profiles

Successful cultivation of mammalian cells must consider careful formulation of culture media consisting of a variety of substrates and amino acids. A widely cited method for quantifying metabolic networks of mammalian cultures is dynamic flux balance modelling. Application of in-silico techniques allows researchers to circumvent time-consuming and costly in-vivo experimentation. Dynamic simulation and optimisation of reliable models allows for the visualization of opportunities to improve throughputs of target protein products, such as monoclonal antibodies (mAbs). This study presents a sensitivity analysis comparing dynamic optimisation results for industrial-scale fed-batch bioreactors, considering a variety of initial conditions. Optimized feeding trajectories are computed via Nonlinear Programming (NLP) model, employing the established IPOPT solver. Glucose, then glutamine, then asparagine, can lead to improved mAb yields and viable cell counts.

Dynamic Optimization for Monoclonal Antibody Production

This paper presents a dynamic optimization numerical case study for Monoclonal Antibody (mAb) production. The fermentation is conducted in a continuous perfusion reactor. We represent the existing model in terms of a general modeling methodology well-suited for simulation and optimization. The model consists of six ordinary differential equations (ODEs) for the non-constant volume and the five components in the reactor. We extend the model with a glucose inhibition term to make the model feasible for optimization case studies. We formulate an optimization problem in terms of an optimal control problem (OCP) and consider four different setups for optimization. Compared to the base case, the optimal operation of the perfusion reactor increases the mAb yield with 44% when samples are taken from the reactor and with 52% without sampling. Additionally, our results show that multiple optimal feeding trajectories exist and that full glucose utilization can be forced without loss of mAb formation.

Surface feature and material removal in ultrasonic vibration-assisted slot-milling of Ti–6Al–4 V titanium alloy

The continuous optimization of processing technology and evaluation methods is an important way to achieve high processing quality and processing efficiency for difficult-to-process materials. To solve the problem of frequent defects in the slot, the ultrasonic vibration-assisted slot-milling (UVASM) technology was developed for processing titanium alloy. Simultaneously, comparative experiments were carried out between UVASM and conventional slot milling (CSM), in terms of surface features of slot bottom and slot sidewall, cutting force, tool trajectory, chip morphology, and micro-hardness. The results show that uniform vibration micro-texture could significantly improve surface topography of slot bottom in UVASM, while numerous tool feed trajectories and observable machining defects detract from the surface quality in CSM. The UVASM can greatly reduce material spalling and edge breakage, thereby maintaining a smooth and regular edge profile of the slot sidewall. The tool tip trajectories of the two machining methods are highly corresponding to the machining textures of the slot sidewall surface. There is a high-frequency and small-amplitude force fluctuation signal on the axial force waveform in UVASM, which can reduce the instantaneous maximum milling force and milling force in the stable stage by 8.7 and 12.2%, respectively. The UVASM has a better chip breaking effect and surface anti-scratch effect, and the UVASM can obtain higher surface micro-hardness and deeper plastic deformation layer than those CSM. In summary, the multi-dimensional evaluation of slot processing status has been completed, and the processing quality of the slot has been improved.

Optimal Feeding Strategy in Fermentation of Docosahexaenoic Acid Production by Schizochytrium sp.

AbstractFed‐batch fermentation has the potential to increase the production of docosahexaenoic acid (DHA) in Schizochytrium sp. which can provide additional nutrients. The feeding strategy in fed‐batch fermentation is one of the important aspects that could help in improving the DHA yield. An enhanced scatter search (eSS) method and the control vector parametrization (CVP) approach were applied to generate the optimal feeding trajectory numerically. Three objective functions were considered, namely, maximizing the DHA concentration, minimizing the final time, and maximizing the economic function. The shortest time and maximum DHA could be determined simultaneously from the optimal feeding trajectory in maximizing the economic function.

Rotational feeding combined with shift feeding in the electrochemical trepanning of a blisk

The structure of the blades on a blisk is generally characterized by spatial distortion and spatial bending. Electrochemical trepanning (ECTr) is an effective roughing method in blisk manufacturing. To improve the structural characteristics and the allowance distribution uniformity manufactured by ECTr, a new feeding strategy, in which the relative motion of the cathode and the workpiece is due to simultaneous rotational feeding (RF) and shift feeding (SF), is proposed. The approach is called the rotational feeding combined with shift feeding (RF-SF) strategy. A parametric model and an optimized method for calculating the feeding trajectory (FT) under the RF-SF strategy are presented. To assess the effectiveness of the proposed method, the FTs for a twisted blade with variable cross section and a degree of bending were calculated and simulated for the RF and RF-SF strategies. Compared with the RF strategy, the uniformity of the allowance distribution under the RF-SF strategy was improved by 60.4% and 50.3% at the concave and convex parts, respectively. A blade was machined with RF-SF ECTr. The deviations between the experimental and simulated results were 7.1% and 8.1%, respectively, thereby verifying the effectiveness of the proposed method.

107. Understanding the Lived Experience, Barriers, and Facilitators of Infant Feeding for Adolescent Mothers

Data indicates that while 60% of adolescent mothers will initiate breastfeeding, only 20% continue to do so at 6 months. However, there is limited literature exploring the unique social determinants and distinct facilitators and barriers that influence adolescent mothers’ infant feeding practices. This study aims to explore the infant feeding trajectories of adolescent mothers, and to identify facilitators and barriers that may impact breastfeeding initiation and continuation. Additionally, this study seeks to examine adolescent mothers’ experiences with healthcare providers and their preferences with regards to education and support around infant feeding practices.

Gestational Age-Related Associations between Early-Life Feeding Trajectories and Growth Outcomes at Term Equivalent Age in Very Preterm Infants.

Establishing the different feeding trajectories based on daily enteral feeding data in preterm infants at different gestational ages (GAs), may help to identify the risks and extrauterine growth restriction (EUGR) outcomes associated with the adverse feeding pattern. In a single center, we retrospectively included 625 infants born at 23–30 weeks of gestation who survived to term-equivalent age (TEA) from 2009 to 2020. The infants were designated into three GA groups: 23–26, 27–28, and 29–30 weeks. The daily enteral feeding amounts in the first 56 postnatal days were analyzed to determine the feeding trajectories. The primary outcomes were EUGR in body weight and head circumference calculated, respectively, by the changes between birth and TEA. Clustering analysis identified two feeding trajectories, namely the improving and adverse patterns in each GA group. The adverse feeding pattern that occurred in 49%, 20%, and 17% of GA 23–26, 27–28, and 29–30 weeks, respectively, was differentiated from the improving feeding pattern as early as day 7 in infants at GA 23–26 and 27–28 weeks, in contrast to day 21 in infants at GA 29–30 weeks. The adverse feeding patterns were associated with sepsis, respiratory, and gastrointestinal morbidities at GA 23–26 weeks; sepsis, hemodynamic and gastrointestinal morbidities at GA 27–28 weeks; and preeclampsia, respiratory, and gastrointestinal morbidities at GA 29–30 weeks. Using the improving feeding group as a reference, the adverse feeding group showed significantly higher adjusted odds ratios of EUGR in body weight and head circumference in infants at GA 23–26 and 27–28 weeks. Identifying the early-life adverse feeding trajectories may help recognize the related EUGR outcomes of preterm infants in a GA-related manner.

Feeding in the first six months of life is associated with the probability of having bronchiolitis: a cohort study in Spain

BackgroundBreastfeeding is associated with lower incidence and severity of lower respiratory tract disease. However, little is known about the relationship between feeding type and breastfeeding duration with bronchiolitis in a child’s first year.MethodsA prospective cohort study of 969 newborn babies were followed-up for 12 months to determine breastfeeding duration, feeding type, feeding trajectory, and bronchiolitis episodes at Marqués de Valdecilla University Hospital, Spain in 2018. Type of feeding was recorded by interviewing mothers at the time of hospital discharge and at 2, 4, 6, 9 and 12 months of life, in three categories: breastfeeding, mixed feeding and infant formula. Type of feeding at hospital discharge refers to feeding from birth to discharge. In any other times studied, it refers to feeding in the last 24 h. The association between the feeding type and bronchiolitis was analysed using logistic regression. Poisson regression was used to evaluate the association between feeding type and the number of bronchiolitis episodes with Kaplan-Meier estimators presenting the cumulative probability of suffering bronchiolitis. The results were adjusted for mother and child characteristics.ResultsOur data shows exclusive breastfeeding and mixed breastfeeding reduce the number of episodes of bronchiolitis. Regarding feeding at 4 months, exclusive breastfeeding reduced by 41% the number of episodes of bronchiolitis (adjusted incidence Ratio (aIR) 0.59, 95% CI 0.46, 0.76) and mixed feeding by 37% (aIR 0.63, 95% CI 0.47, 0.86). Moreover, changing from exclusive breastfeeding to mixed feeding increased the incidence of bronchiolitis compared with continuing exclusive breastfeeding. An early swap to mixed breastfeeding before months 2 or 4, was associated with a reduced the number of episodes of bronchiolitis, (aIR 0.53, 95% CI 0.39, 0.73 if introduction of mixed breastfeeding before month 2, and aIR 0.61, 95% CI 0.45, 0.83 if introduction of mixed breastfeeding before month 4), when compared with infant formula alone.ConclusionsAny breastfeeding was associated with lower incidence of bronchiolitis and number of episodes of bronchiolitis in the first year of life. Consequently, promoting programmes facilitating exclusive or mixed breastfeeding would be a relevant measure in the prevention of bronchiolitis.

Neonatal Feeding Trajectories in Mothers With Bipolar Disorder Taking Lithium: Pharmacokinetic Data.

Purpose: Women who take lithium during pregnancy and continue after delivery may choose to breastfeed, formula feed, or mix these options. The aim of the study was to evaluate the neonatal lithium serum concentrations based on these three feeding trajectories.Methods: We followed 24 women with bipolar disorder treated with lithium monotherapy during late pregnancy and postpartum (8 per trajectory). Lithium serum concentrations were determined by an AVL 9180 electrolyte analyser with a 0.10 mEq/L detection limit and a 0.20 mEq/L limit of quantification (LoQ).Results: There was complete lithium placental passage at delivery, with a mean ratio of lithium concentration in the umbilical cord to maternal serum of 1.12 ± 0.17. The median times to LoQ were 6–8, 7–8, and 53–60 days for formula, mixed, and exclusive breastfeeding respectively. The generalized log-rank testing indicated that the median times to LoQ differ according to feeding trajectory (p = 0.037). According to the multivariate analysis-adjusted lithium serum concentrations at birth, times to LoQ are, on average, longer under exclusive breastfeeding (formula, p = 0.015; mixed, p = 0.012). No lithium accumulation was observed in infants under either exclusive or mixed breastfeeding. During the lactation follow-up, there was no acute growth or developmental delays in any neonate or infant. Indeed, lithium concentrations in the three trajectories declined in all cases. However, the time needed to reach the LoQ was much longer for those breastfeeding exclusively.Conclusions: In breastfeed infant no sustained accumulation of lithium and no adverse effects on development or growth were observed.

Model-based reinforcement learning and predictive control for two-stage optimal control of fed-batch bioreactor

In this study, we propose a two-stage optimal control framework for a fed-batch bioreactor. The high-level controller aims to obtain the optimal feed trajectory that maximizes the final time productivity and yield using a nominal model. By contrast, the low-level controller maintains the high-level performance in the presence of the model-plant mismatch and real-time disturbances. This two-stage decomposition can perform the closed-loop operation with less online recomputation. To solve the high-level optimization, differential dynamic programming (DDP), a model-based reinforcement learning that employs the derivatives of the model is applied. Three types of low-level controllers are proposed: DDP controller, a model predictive control (MPC) that tracks the high-level trajectory, and an economic MPC. We first validate that DDP yields as good result as the direct method. Second, we compare the three low-level controllers and verify the necessity of the two-stage decomposition through the studies on a bioreactor.

Infant exposure to lithium through breast milk

IntroductionWomen who take lithium during pregnancy and continue after delivery may opt to breastfeed, formula feed, or mix these options.ObjectivesTo evaluate the neonatal lithium plasma concentrations and nursing infant outcomes based on these three feeding trajectories.MethodsWe followed 24 women with bipolar disorder on lithium monotherapy during late pregnancy and postpartum (8 per trajectory). Lithium serum concentrations were determined by an AVL 9180 electrolyte analyser with a 0.10 mEq/L detection limit and a 0.20 mEq/L limit of quantification (LoQ).ResultsThe mean ratio of lithium concentration in the umbilical cord to maternal serum being 1.12 (0.17). We used the Turnbull estimator for interval-censored data to estimate the probability that the LoQ was reached as a function of time. The median times to LoQ was 6–8, 7–8, and 53–60 days for formula, mixed, and breastfeeding, respectively. Generalised log-rank testing indicated that the median times to LoQ differed by feeding trajectory (p = 0.037). Multivariate analysis confirmed that the differences remained after adjusting for serum lithium concentrations at birth (formula, p = 0.015; mixed, p = 0.012). We did not found any acute observable growth or developmental delays in any of the neonates/infants.ConclusionsLithium did not accumulate in the infant under either exclusive or mixed-breastfeeding. Lithium concentrations declined in all trayectories. The time needed to reach the LoQ was much longer for those breastfeeding exclusively. Lithium transfer via breastmilk is much less than via the placenta. We did not found any acute observable growth or developmental delays in any infant during follow-up.DisclosureNo significant relationships.

Velocity planning in multi-axis EDM based on a coder-player architecture

With a higher requirement on machining accuracy in electrical discharging machining (EDM), there is a drastically increased number of multi-axis line segments for machining complex workpieces. High speed jumping is needed for a conducive discharge gap status. The increased number of line segments, however, makes the implementation of high-speed jumping difficult. To alleviate the online computational burden for velocity planning, this paper proposes a multi-axis velocity planning based on a coder-player architecture. Under this architecture, a multi-axis feeding trajectory is represented by a series of double non-uniform rational B-spline (NURBS) curves, which are then interpolated by the unit arc length increment interpolation (UALII) method. Based on the interpolation points with a resolution of a basic length unit (BLU), a velocity limit curve is generated by considering simultaneously the constraints on chord error, acceleration and jerk. The velocity planning is implemented under a coder-player architecture. As a trajectory represented by a double-NURBS curve has C2 continuity, velocity losses can be avoided at junctions between line segments, thus smoothing of line segments at junctions is unnecessary in jumping. Machining tests showed that by the use of the velocity planning based on double-NURBS curves, the machining time for one channel of a shrouded blisk can be decreased by 29.38%.

Feeding strategy optimization for a blisk with twisted blades in electrochemical trepanning

Blisk manufacturing generally involves two steps in electrochemical machining, namely roughing and finishing, with the aim of the former being to form the blade blank with an allowance that is as uniform as possible. This paper focuses on improving the allowance uniformity in the roughing stage of blisk. Electrochemical trepanning (ECTr) is an effective roughing method. To homogenize the allowance distribution of twisted blades on a blisk in ECTr, this paper proposes a cathode-rotating feeding strategy that involves both a constant rotation rate and a variable one. To examine how those two modes differ, kinematic simulations are performed. To determine the optimal rotation feeding trajectories, under the established parametric model, an evaluation criterion based on the minimum value among the maximum allowance differences (MADs) is proposed and adaptive particle swarm optimization intelligent algorithm is adopted. For a twisted blade with varying cross section, the feeding trajectories of the two modes are calculated and simulated. Under constant-rotation-rate feeding, the values of the MAD for the predicted blade are 1.478 mm and 1.432 mm at the concave and convex parts, respectively. The values of MAD are reduced to 0.849 mm and 0.961 mm, respectively, under variable-rotation-rate feeding, and the uniformities of the allowance distributions are improved by 42.6 % and 32.9 %, respectively. The experiment of cathode-rotating feeding ECTr with variable rotation rate was performed. For the machined blade, the values of MAD at the concave and convex parts are 0.955 mm and 0.786 mm, respectively. The deviations between the experiments and simulations are 11.1 % and 18.2 %, respectively, thereby showing the optimization method to be effective.

Optimal Feed Trajectories for Fedbatch Fermentation with Substrate Inhibition Kinetics

Abstract We provide optimal feed trajectories for fedbatch fermentation of microorganisms with substrate inhibition kinetics. We demonstrate that the optimal trajectories are non-unique and provide analytical procedures for solving the optimal control problem. Since, the optimal trajectories are non-unique this is essential for practical operations as a numerical solution could be any of the feasible non-unique optimal solutions. In addition, we investigate the sensitivity of the optimal trajectories and demonstrate that a bang-bang solution is optimal from a sensitivity point of view. This insight is relevant for model predictive control of fedbatch fermentation.

Robot-assisted feeding: A technical application that combines learning from demonstration and visual interaction.

The traditional meal assistance robots use human-computer interaction such as buttons, voice, and EEG. However, most of them rely on excellent programming technology for development, in parallelism with exhibiting inconvenient interaction or unsatisfactory recognition rates in most cases. To develop a convenient human-computer interaction mode with a high recognition rate, which allows users to make the robot show excellent adaptability in the new environment without programming ability. A visual interaction method based on deep learning was used to develop the feeding robot: when the camera detects that the user's mouth is open for 2 seconds, the feeding command is turned on, and the feeding is temporarily conducted when the eyes are closed for 2 seconds. A programming method of learning from the demonstration, which is simple and has strong adaptability to different environments, was employed to generate a feeding trajectory. The user is able to eat independently through convenient visual interaction, and it only requires the caregiver to drag and teach the robotic arm once in the face of a new eating environment.