Objective To evaluate in-hospital formula supplementation among first time mothers who intended to exclusively breastfeed and determined if in-hospital formula supplementation shortens breastfeeding duration after adjusting for breastfeeding intention. Study design We assessed strength of breastfeeding intentions prenatally in a diverse cohort of expectant primiparae and followed infant feeding practices through day 60. Among mothers planning to exclusively breastfed their healthy term infants for ≥1 week, we determined predictors, reasons, and characteristics of in-hospital formula supplementation; and calculated the intention-adjusted relative risk (ARR) of not fully breastfeeding days 30–60 and breastfeeding cessation by day 60 with in-hospital formula supplementation (n=393). Results 210 (53%) infants exclusively breastfed during the maternity stay and 183 (47%) received in-hospital formula supplementation. The most prevalent reasons mothers cited for inhospital formula supplementation were: perceived insufficient milk supply (18%), signs of inadequate intake (16%), and poor latch or breastfeeding (14%). Prevalence of not fully breastfeeding days 30–60 was 67.8% vs 36.7%, ARR 1.8 [95% CI, 1.4–2.3], in-hospital formula supplementation vs exclusively breastfed groups respectively, and breastfeeding cessation by day 60 was 32.8% vs 10.5%, ARR 2.7 [95% CI,1.7–4.5]. Odds of both adverse outcomes increased with more in-hospital formula supplementation feeds (not fully breastfeeding days 30–60, P=.003 and breastfeeding cessation, P=.011). Conclusions Among women intending exclusively breastfed, in-hospital formula supplementation was associated with nearly 2-fold greater risk of not fully breastfeeding days 30–60 and nearly 3-fold risk of breastfeeding cessation by day 60, even after adjusting for strength of breastfeeding intentions. Strategies should be sought to avoid unnecessary in-hospital formula supplementation and to support breastfeeding when in-hospital formula supplementation is unavoidable.

WHAT'S KNOWN ON THIS SUBJECT: Although most US mothers initiate breastfeeding, half fail to achieve their breastfeeding intentions. In cross-sectional and retrospective surveys, early breastfeeding difficulties are often cited as reasons for stopping breastfeeding earlier than intended. WHAT THIS STUDY ADDS:We characterized 4179 breastfeeding concerns/problems as reported by primiparas interviewed prospectively. Concerns were highly prevalent and associated with up to ninefold greater risk of stopping breastfeeding earlier than intended. Concerns at 3 to 7 days posed the greatest risk.abstract OBJECTIVE: We characterized breastfeeding concerns from open-text maternal responses and determined their association with stopping breastfeeding by 60 days (stopping breastfeeding) and feeding any formula between 30 and 60 days (formula use). METHODS:We assessed breastfeeding support, intentions, and concerns in 532 expectant primiparas and conducted follow-up interviews at 0, 3, 7, 14, 30, and 60 days postpartum. We calculated adjusted relative risk (ARR) and adjusted population attributable risk (PAR) for feeding outcomes by concern category and day, adjusted for feeding intentions and education. RESULTS:In 2946 interviews, 4179 breastfeeding concerns were reported, comprising 49 subcategories and 9 main categories. Ninetytwo percent of participants reported $1 concern at day 3, with the most predominant being difficulty with infant feeding at breast (52%), breastfeeding pain (44%), and milk quantity (40%). Concerns at any postpartum interview were significantly associated with increased risk of stopping breastfeeding and formula use, with peak ARR at day 3 (eg, stopping breastfeeding ARR [95% confidence interval] = 9.2 [3.0-infinity]). The concerns yielding the largest adjusted PAR for stopping breastfeeding were day 7 "infant feeding difficulty" (adjusted PAR = 32%) and day 14 "milk quantity" (adjusted PAR = 23%).CONCLUSIONS: Breastfeeding concerns are highly prevalent and associated with stopping breastfeeding. Priority should be given to developing strategies for lowering the overall occurrence of breastfeeding concerns and resolving, in particular, infant feeding and milk quantity concerns occurring within the first 14 days postpartum. Pediatrics 2013;132:e865-e875 AUTHORS:

High-resolution water vapour measurements made by the Atmospheric Radiation Measurement (ARM) Raman lidar operated at the Southern Great Plains Climate Research Facility site near Lamont, Oklahoma, U.S.A. are presented. Using a 2-h measurement period for the convective boundary layer (CBL) on 13 September 2005, with temporal and spatial resolutions of 10 s and 75 m, respectively, spectral and autocovariance analyses of water vapour mixing ratio time series are performed. It is demonstrated that the major part of the inertial subrange was detected and that the integral scale was significantly larger than the time resolution. Consequently, the major part of the turbulent fluctuations was resolved. Different methods to retrieve noise error profiles yield consistent results and compare well with noise profiles estimated using Poisson statistics of the Raman lidar signals. Integral scale, mixing-ratio variance, skewness, and kurtosis profiles were determined including error bars with respect to statistical and sampling errors. The integral scale ranges between 70 and 130 s at the top of the CBL. Within the CBL, up to the third order, noise errors are significantly smaller than sampling errors and the absolute values of turbulent variables, respectively. The mixing-ratio variance profile rises monotonically from ≈0.07 to ≈3.7 g 2 kg −2 in the entrainment zone. The skewness is nearly zero up to 0.6 z/z i , becomes −1 around 0.7-0.8 z/z i , crosses zero at about 0.95 z/z i , and reaches about 1.7 at 1.1 z/z i (here, z is the height and z i is the CBL depth). The noise errors are too large to derive fourth-order moments with sufficient accuracy. Consequently, to the best of our knowledge, the ARM Raman lidar is the first water vapour Raman lidar with demonstrated capability to retrieve profiles of turbulent variables up to the third order during daytime throughout the atmospheric CBL.

ImportanceFor walking rehabilitation after stroke, training intensity and duration are critical dosing parameters that lack optimization.ObjectiveTo assess the optimal training intensity (vigorous vs moderate) and minimum training duration (4, 8, or 12 weeks) needed to maximize immediate improvement in walking capacity in patients with chronic stroke.Design, Setting, and ParticipantsThis multicenter randomized clinical trial using an intent-to-treat analysis was conducted from January 2019 to April 2022 at rehabilitation and exercise research laboratories. Survivors of a single stroke who were aged 40 to 80 years and had persistent walking limitations 6 months or more after the stroke were enrolled.InterventionsParticipants were randomized 1:1 to high-intensity interval training (HIIT) or moderate-intensity aerobic training (MAT), each involving 45 minutes of walking practice 3 times per week for 12 weeks. The HIIT protocol used repeated 30-second bursts of walking at maximum safe speed, alternated with 30- to 60-second rest periods, targeting a mean aerobic intensity above 60% of the heart rate reserve (HRR). The MAT protocol used continuous walking with speed adjusted to maintain an initial target of 40% of the HRR, progressing up to 60% of the HRR as tolerated.Main Outcomes and MeasuresThe main outcome was 6-minute walk test distance. Outcomes were assessed by blinded raters after 4, 8, and 12 weeks of training.ResultsOf 55 participants (mean [SD] age, 63 [10] years; 36 male [65.5%]), 27 were randomized to HIIT and 28 to MAT. The mean (SD) time since stroke was 2.5 (1.3) years, and mean (SD) 6-minute walk test distance at baseline was 239 (132) m. Participants attended 1675 of 1980 planned treatment visits (84.6%) and 197 of 220 planned testing visits (89.5%). No serious adverse events related to study procedures occurred. Groups had similar 6-minute walk test distance changes after 4 weeks (HIIT, 27 m [95% CI, 6-48 m]; MAT, 12 m [95% CI, −9 to 33 m]; mean difference, 15 m [95% CI, −13 to 42 m]; P = .28), but HIIT elicited greater gains after 8 weeks (58 m [95% CI, 39-76 m] vs 29 m [95% CI, 9-48 m]; mean difference, 29 m [95% CI, 5-54 m]; P = .02) and 12 weeks (71 m [95% CI, 49-94 m] vs 27 m [95% CI, 3-50 m]; mean difference, 44 m [95% CI, 14-74 m]; P = .005) of training; HIIT also showed greater improvements than MAT on some secondary measures of gait speed and fatigue.Conclusions and RelevanceThese findings show proof of concept that vigorous training intensity is a critical dosing parameter for walking rehabilitation. In patients with chronic stroke, vigorous walking exercise produced significant and meaningful gains in walking capacity with only 4 weeks of training, but at least 12 weeks were needed to maximize immediate gains.Trial RegistrationClinicalTrials.gov Identifier: NCT03760016

We report here that among exclusively breastfeeding mothers at day 7 postpartum, those with milk supply concerns were significantly more likely to exhibit biochemical evidence of less progress toward mature lactation (elevated milk Na:K). Furthermore, elevated milk Na:K was predictive of early weaning.