11,557 research outputs found
Reduced, tame and exotic fusion systems
We define here two new classes of saturated fusion systems, reduced fusion
systems and tame fusion systems. These are motivated by our attempts to better
understand and search for exotic fusion systems: fusion systems which are not
the fusion systems of any finite group. Our main theorems say that every
saturated fusion system reduces to a reduced fusion system which is tame only
if the original one is realizable, and that every reduced fusion system which
is not tame is the reduction of some exotic (nonrealizable) fusion system
Developmental trajectories of bottle-feeding during infancy and their association with weight gain
Objective: To describe patterns of bottle-feeding across the first year postpartum and explore whether bottle-feeding trajectories are differentially associated with infant weight gain. Method: Data came from 1291 mothers who participated in the Infant Feeding Practices Study 2. Mothers completed a prenatal questionnaire and monthly surveys of infant feeding and growth between birth and 12 months. Group-based trajectory mixture modeling was used to describe developmental trajectories of bottle-feeding intensities across the first year. Growth curve modeling was used to explore associations between bottle-feeding intensity trajectory group membership and weight-for-age z-score (WAZ) trajectories from birth to 12 months. Results: Four qualitatively distinct trajectories of bottle-feeding were identified: (1) High-Stable: ∼100% of feeds from bottles across infancy; (2) Rapid-Increase:Gradual-Increase:Low-Stable:p \u3c .001). The association between bottle-feeding group membership and WAZ trajectories was not confounded by sociodemographic characteristics or the extent to which infants received breast milk. Conclusion: High-intensity bottle use during early infancy may place infants at higher risk for excess weight gain. Supports and policies that help mothers delay high-intensity bottle use until later infancy are warranted
Associations between Breastfeeding and Maternal Responsiveness: A Systematic Review of the Literature
Recent recommendations and prevention programs have focused on the promotion of responsive feeding during infancy, but more research is needed to understand best practices for fostering responsive feeding during early life. The objective of this systematic review was to synthesize the accumulating bodies of evidence aimed at understanding associations between mothers\u27 feeding experiences and responsive feeding in an attempt to clarify the nature of associations between feeding mode and responsive feeding. A literature search was conducted between January and October 2016; articles were collected from PsychINFO, Medline, and CINAHL, as well as from references in published research and reviews. Article inclusion criteria were as follows: 1) empirical research, 2) included a measure of infant feeding, 3) included a measure of maternal responsiveness, 4) study conducted in human participants, 5) available in English, and 6) study conducted in a developed and/or high-income country. Forty-three studies were identified. Cross-sectional observational studies consistently reported greater responsiveness among breastfeeding mothers than among formula-/bottle-feeding mothers. In addition, longitudinal studies showed that longer breastfeeding durations predicted lower use of nonresponsive feeding practices during later childhood, and some, but not all, found that breastfeeding mothers showed greater increases in responsiveness across infancy than did formula-/bottle-feeding mothers. However, a limited number of longitudinal studies also reported that greater responsiveness during early infancy predicted longer breastfeeding durations. A common limitation among these studies is the correlational nature of their designs and lack of prenatal measures of maternal responsiveness, which hinders our understanding of causal mechanisms. Although 2 randomized clinical trials aimed at promoting maternal responsiveness did not find effects of the intervention on breastfeeding outcomes, these findings were limited by the way in which breastfeeding outcomes were assessed. In sum, although there is consistent evidence for an association between breastfeeding and responsive feeding, more research is needed to better understand the mechanisms underlying this association
Does Breastfeeding Shape Food Preferences? Links to Obesity
The first 2 years of life have been recognized as a critical window for obesity prevention efforts. This period is characterized by rapid growth and development and, in a relatively short period of time, a child transitions from a purely milk-based diet to a more varied solid-food diet. Much learning about food and eating occurs during this critical window, and it is well-documented that early feeding and dietary exposures predict later food preferences, eating behaviors, and dietary patterns. The focus of this review will be on the earliest feeding experiences - breast- and formula-feeding - and the unique role of breastfeeding in shaping children\u27s food preferences. Epidemiological data illustrate that children who were breastfed have healthier dietary patterns compared to children who were formula-fed, even after controlling for relevant sociodemographic characteristics associated with healthier dietary and lifestyle patterns. These dietary differences are underlined, in part, by early differences in the opportunities for flavor learning and preference development afforded by breast- versus formula-feeding. In particular, the flavors of the mothers\u27 diet are transmitted from mother to child through the amniotic fluid and breastmilk. The flavors experienced in these mediums shape later food preferences and acceptance of the solid foods of the family and culture onto which the infant is weaned. All infants learn from flavor experiences in utero, but only breastfed infants receive the additional reinforcement and flavor learning provided by continued repeated exposure to a wide variety of flavors that occurs during breastfeeding. Given the numerous benefits of breastfeeding, promotion of breastfeeding during early infancy is an important focus for primary prevention efforts and should be combined with efforts to ensure that mothers consume healthy, varied diets during pregnancy and lactation, and expose their infants to a wide array of foods during weaning and solid-food feeding
Scattering by PT-symmetric non-local potentials
A general formalism is worked out for the description of one-dimensional
scattering by non-local separable potentials and constraints on transmission
and reflection coefficients are derived in the cases of P, T, or PT invariance
of the Hamiltonian. The case of a solvable Yamaguchi potential is discussed in
detail.Comment: 11 page
Early Influences on the Development of Food Preferences
The ability to perceive flavors begins in utero with the development and early functioning of the gustatory and olfactory systems. Because both amniotic fluid and breast milk contain molecules derived from the mother’s diet, learning about flavors in foods begins in the womb and during early infancy. This early experience serves as the foundation for the continuing development of food preferences across the lifespan, and is shaped by the interplay of biological, social, and environmental factors. Shortly after birth, young infants show characteristic taste preferences: sweet and umami elicit positive responses; bitter and sour elicit negative responses. These taste preferences may reflect a biological drive towards foods that are calorie- and protein-dense and an aversion to foods that are poisonous or toxic. Early likes and dislikes are influenced by these innate preferences, but are also modifiable. Repeated exposure to novel or disliked foods that occurs in a positive, supportive environment may promote the acceptance of and eventually a preference for those foods. Alternatively, children who are pressured to eat certain foods may show decreased preference for those foods later on. With increasing age, the influence of a number of factors, such as peers and food availability, continue to mold food preferences and eating behaviors
Maternal Distraction During Breast- and Bottle Feeding Among WIC and non-WIC Mothers
Objective: To explore the prevalence and correlates of maternal distraction during infant feeding within a sample of mothers enrolled or not in the Special Supplemental Nutrition Program for Woman, Infants, and Children (WIC).
Design: Mothers kept diaries of their infants’ feeding patterns.
Participants: Mothers (n = 75) with infants aged ≤6 months.
Main Outcome Measures: Within the diaries, mothers recorded what else, if anything, they did during the feeding. Mothers also completed questionnaires on demographics, feeding styles, and infant temperament and eating behaviors.
Analysis: Mothers’ responses were coded into thematic categories. Feedings were classified as distracted when the mothers reported doing something other than feeding and/or interacting with the infant. Logistic regression was used to explore whether mothers exhibited different levels of distraction when breastfeeding (BF) vs bottle feeding. The researchers used multiple stepwise regression to explore associations between distracted feeding and characteristics of mothers and infants.
Results: Distractions were reported during 43% of feedings; 26% involved technological distractors. Mothers who were multiparous and perceived that their infants had greater appetites reported greater levels of any distraction during feeding. Mothers who were of racial/ethnic minorities, adhered to laissez faire feeding style, had younger infants, and perceived their infants to have lower food responsiveness and greater appetite reported greater levels of technological distraction. Being enrolled inWIC was not associated with mothers’ levels of distracted feeding.
Conclusions and Implications: Mothers reported a wide variety of distractions during both BF and bottle feeding; higher levels of distraction were associated with characteristics of both mothers and infants. Further research is needed to understand whether and how maternal distraction affects feeding outcomes. Awareness of such distractions and their potential impact would be useful to practitioners working with pregnant and postpartum women
Effects of Opaque, Weighted Bottles on Maternal Sensitivity and Infant Intake
Caregivers\u27 abilities to assess how much is in the bottle may lead to encouragement of infant bottle emptying and overfeeding. The present study assessed whether use of opaque, weighted bottles (as compared with conventional, clear bottles) improves feeding outcomes. Mothers with infants \u3c32 weeks of age (n = 76) were assessed on two separate days. Mothers fed their infants from an opaque, weighted bottle on 1 day and a clear bottle on the other; conditions were counterbalanced. Blinded raters certified in the Nursing Child Assessment Feeding Scale scored all videos to determine maternal sensitivity. Infant intake was assessed by weighing the bottle before and after each feeding, and feeding outcomes included infant intake (mL), intake per kilogram body weight (mL/kg), meal duration (min), and feed rate (mL/ min). Mothers exhibited significantly greater sensitivity (p = 0.041), fed their infants fewer millilitres per kilogram body weight (p = 0.049), and fed their infants at a significantly slower rate (p = 0.009) when using opaque compared with clear bottles. Infant clarity of cues was a significant moderator of effects of bottle type on intake per kilogram body weight (p = 0.028): Infants who exhibited greater clarity of cues were fed less during the opaque versus clear conditions whereas infants who exhibited poorer clarity of cues were fed similar amounts during both conditions. Effects of bottle type were not moderated by bottle contents (expressed breast milk vs. formula). In sum, promotion of opaque, weighted bottles for infant feeding may be a pragmatic approach to improve the quality and outcome of bottle‐feeding interactions
Real rank boundaries and loci of forms
In this article we study forbidden loci and typical ranks of forms with
respect to the embeddings of given by the line
bundles . We introduce the Ranestad-Schreyer locus corresponding to
supports of non-reduced apolar schemes. We show that, in those cases, this is
contained in the forbidden locus. Furthermore, for these embeddings, we give a
component of the real rank boundary, the hypersurface dividing the minimal
typical rank from higher ones. These results generalize to a class of
embeddings of . Finally, in connection with real
rank boundaries, we give a new interpretation of the
hyperdeterminant.Comment: 17 p
Spectroscopy and Imaging Performance of the Liquid Xenon Gamma-Ray Imaging Telescope (LXeGRIT)
LXeGRIT is a balloon-borne Compton telescope based on a liquid xenon time
projection chamber (LXeTPC) for imaging cosmic \g-rays in the energy band of
0.2-20 MeV. The detector, with 400 cm area and 7 cm drift gap, is filled
with high purity LXe. Both ionization and scintillation light signals are
detected to measure the energy deposits and the three spatial coordinates of
individual \g -ray interactions within the sensitive volume. The TPC has been
characterized with repeated measurements of its spectral and Compton imaging
response to \g -rays from radioactive sources such as \na, \cs, \yt and Am-Be.
The detector shows a linear response to \g -rays in the energy range 511 keV
-4.4 MeV, with an energy resolution (FWHM) of \Delta E/E=8.8% \: \sqrt{1\MeV
/E}. Compton imaging of \yt \g -ray events with two detected interactions is
consistent with an angular resolution of 3 degrees (RMS) at 1.8 MeV.Comment: To appear in: Hard X-Ray, Gamma-Ray and Neutron Detector Physics XI,
2000; Proc. SPIE, vol. 4140; K.A. Flanagan & O.H. Siegmund, ed
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