Breastfeeding Infants with Phenylketonuria in the United States and Canada

Objective: This study described the prevalence and duration of mothers’ breastfeeding infants with phenylketonuria (PKU) and explored factors related to duration of breastfeeding as a surrogate for breastfeeding success. Subjects and Methods: Descriptive analysis as performed from an international Internet survey of mothers (n = 103) who met the inclusion criteria: (1) at least 21 years of age, (2) able to read and write in English, (3) child with PKU, and (4) living in the United States or Canada. Results: Of the 103 mothers, 89 (86%) initiated breastfeeding immediately following delivery, whereas 14 (14%) chose bottle feeding. In comparison to breastfeeding after delivery, significantly fewer mothers breastfed after diagnosis (McNemar’s v2 = 30.33, p \u3c 0.001; n = 72 vs. n = 89). Breastfeeding duration ranged from less than 1 month to 24 months with one modal duration category (n = 20, 22%) at less than 1 month. The timing of the addition of commercial infant formula to supplement breastfeeding or expressed mothers’ milk was associated with a shorter duration of breastfeeding among infants with PKU: v2 (42, n = 73) = 88.13, p \u3c 0.001. Conclusions: PKU is treated with phenylalanine (Phe) restriction. Breastfeeding infants with PKU is challenging in part because Phe intake is difficult to determine precisely. We studied breastfeeding duration in infants with PKU and factors associated with success. Further research should identify the unique needs of mothers’ breastfeeding infants with PKU to guide the development of interventions specific to these mothers to support their efforts to continue breastfeeding after the diagnosis of PKU

Commitment to Breastfeeding in the Context of Phenylketonuria

Objective: To describe the meaning and importance of breastfeeding to mothers of infants with phenylketonuria (PKU). Design: Qualitative description. Setting: Mothers from the United States and Canada were recruited from the PKU Listserv and interviewed by telephone. Participants: Ten breastfeeding mothers with infants who had PKU and were younger than age 36 months. Methods: Mothers’ thoughts, decisions, and experiences of breastfeeding their infants with PKU were collected through telephone interviews. Interviews were transcribed verbatim, and data were analyzed using thematic descriptive analysis in the context of PKU. Results: Participants felt that that breastfeeding an infant with PKU was the healthiest choice and was therefore worth the labor. These women believed that this was what a loving mother would choose. As they continued to breastfeed their infants after diagnosis, the views of the participants changed. Initially they saw PKU as a disorder and felt that their infants were ill; later they felt that their infants were healthy in spite of PKU. Normal could mean a breastfeeding infant with PKU. Conclusion: Findings demonstrate the importance mothers attribute to breastfeeding and their willingness to invest considerable effort to breastfeed. Health care providers working with these mothers should help them strategize for success

MBM 12: young protoplanetary discs at high galactic latitude

(abridged) We present Spitzer infrared observations to constrain disc and dust evolution in young T Tauri stars in MBM 12, a star-forming cloud at high latitude with an age of 2 Myr and a distance of 275 pc. The region contains 12 T Tauri systems, with primary spectral types between K3 and M6; 5 are weak-line and the rest classical T Tauri stars. We first use MIPS and literature photometry to compile spectral energy distributions for each of the 12 members in MBM 12, and derive their IR excesses. The IRS spectra are analysed with the newly developed two-layer temperature distribution (TLTD) spectral decomposition method. For the 7 T Tauri stars with a detected IR excess, we analyse their solid-state features to derive dust properties such as mass-averaged grain size, composition and crystallinity. We find a spatial gradient in the forsterite to enstatite range, with more enstatite present in the warmer regions. The fact that we see a radial dependence of the dust properties indicates that radial mixing is not very efficient in the discs of these young T Tauri stars. The SED analysis shows that the discs in MBM 12, in general, undergo rapid inner disc clearing, while the binary sources have faster discevolution. The dust grains seem to evolve independently from the stellar properties, but are mildly related to disc properties such as flaring and accretion rates.Comment: 14 pages, accepted by Astronomy and Astrophysic

Structural and compositional properties of brown dwarf disks: the case of 2MASS J04442713+2512164

In order to improve our understanding of substellar formation, we have performed a compositional and structural study of a brown dwarf disk. We present the result of photometric, spectroscopic and imaging observations of 2MASS J04442713+2512164, a young brown dwarf (M7.25) member of the Taurus association. Our dataset, combined with results from the literature, provides a complete coverage of the spectral energy distribution from the optical to the millimeter including the first photometric measurement of a brown dwarf disk at 3.7mm, and allows us to perform a detailed analysis of the disk properties. The target was known to have a disk. High resolution optical spectroscopy shows that it is intensely accreting, and powers a jet and an outflow. The disk structure is similar to that observed for more massive TTauri stars. Spectral decomposition models of Spitzer/IRS spectra suggest that the mid-infrared emission from the optically thin disk layers is dominated by grains with intermediate sizes (1.5micron). Crystalline silicates are significantly more abondant in the outer part and/or deeper layers of the disk, implying very efficient mixing and/or additional annealing processes. Sub-millimeter and millimeter data indicate that most of the disk mass is in large grains (>1mm)Comment: 17 pages, 10 figures, 7 tables, accepted for A&

Breastfeeding Success among Infants with Phenylketonuria

Breast milk is the nutrition of choice for human infants (American Academy of Pediatrics, 2005; American Association of Family Physicians, 2008; Association of Women’s Health Obstetric and Neonatal Nurses, 2005; Canadian Paediatric Society, 2005; U.S. Preventive Services Task Force, 2008; World Health Organization, 2009). The literature on the benefits of breast milk and breastfeeding for infants and mothers has established multiple positive outcomes for infants (Hoddinott, Tappin, & Wright, 2008; Horta, Bahl, Martines, & Victora, 2007; Ip et al., 2007). Breast milk has advantages for infants that distinguish it from standard commercial infant formulas. These advantages include growth factors, hormones, immunological factors, and long-chain polyunsaturated fatty acids. For infants with phenylketonuria (PKU), breast milk has additional advantages over any standard commercial infant formula, such as a lower concentration of protein and a lower content of the amino acid, phenylalanine. Despite these benefits, some clinics encourage mothers of infants with PKU to breastfeed whereas others present breastfeeding as an unacceptable option. Although the possible risks and benefits of breastfeeding infants with PKU have been discussed, there is limited research and practice describing breastfeeding infants with PKU. As a result, breastfeeding infants with PKU is based more upon limited clinical experiences rather than upon evidence based practice that aims to apply the best scientific evidence gained from research to clinical decision making

Spitzer spectra of evolved stars in omega Centauri and their low-metallicity dust production

Dust production is explored around 14 metal-poor ([Fe/H] = -1.91 to -0.98) giant stars in the Galactic globular cluster omega Centauri using new Spitzer IRS spectra. This sample includes the cluster's post-AGB and carbon stars and is thus the first representative spectral study of dust production in a metal-poor ([Fe/H] < -1) population. Only the more metal rich stars V6 and V17 ([Fe/H] = -1.08, -1.06) exhibit silicate emission, while the five other stars with mid-infrared excess show only a featureless continuum which we argue is caused by metallic iron dust grains. We examine the metallicity of V42, and find it is likely part of the metal-rich population ([Fe/H] ~ -0.8). Aside from the post-AGB star V1, we find no star from the cluster's bulk, metal-poor ([Fe/H] < -1.5) population - including the carbon stars - to be producing detectable amounts of dust. We compare the dust production to the stars' H-alpha line profiles obtained at the Magellan/Clay telescope at Las Campanas Observatory, finding pulsation shocking in the strongest pulsators (V6, V17 and V42), but evidence of outflow in all other stars. We conclude that the onset of dust production does not signify a fundamental change in the material leaving the star. Our data add to a growing body of evidence that metallic iron dominates dust production in metal-poor, oxygen-rich stars, but that dust is probably not the primary accelerant of winds in this mass-metallicity regime.Comment: 13 pages, 10 figures, accepted MNRA

The Long-Lived Disks in the Eta Chamaeleontis Cluster

We present IRS spectra and revised MIPS photometry for the 18 members of the Eta Chamaeleontis cluster. Aged 8 Myr, the Eta Cha cluster is one of the few nearby regions within the 5-10 Myr age range, during which the disk fraction decreases dramatically and giant planet formation must come to an end. For the 15 low-mass members, we measure a disk fraction ~50%, high for their 8 Myr age, and 4 of the 8 disks lack near-IR excesses, consistent with the empirical definition of "transition'' disks. Most of the disks are comparable to geometrically flat disks. The comparison with regions of different ages suggests that at least some of the "transition" disks may represent the normal type of disk around low-mass stars. Therefore, their flattened structure and inner holes may be related to other factors (initial masses of the disk and the star, environment, binarity), rather than to pure time evolution. We analyze the silicate dust in the disk atmosphere, finding moderate crystalline fractions (~10-30%) and typical grain sizes ~1-3 micron, without any characteristic trend in the composition. These results are common to other regions of different ages, suggesting that the initial grain processing occurs very early in the disk lifetime (<1 Myr). Large grain sizes in the disk atmosphere cannot be used as a proxy for age, but are likely related to higher disk turbulence. The dust mineralogy varies between the 8-12micron and the 20-30 micron features, suggesting high temperature dust processing and little radial mixing. Finally, the analysis of IR and optical data on the B9 star Eta Cha reveals that it is probably surrounded by a young debris disk with a large inner hole, instead of being a classical Be star.Comment: 35 pages, 6 tables, 8 figures; Accepted by Ap

Work-Life Integration Issues for Parents Raising Children with ADHD. Community, Work and Family

PDF version of a presentation given at Community, Work and Family: IV International Conference Actors, Structures, and Theories. Tampere, Finland, May 2011