1,753 research outputs found
Roger Zuckerman and Steven J. Sacher to Professor Silver, 18 December 1963
Professional correspondenc
Assessing the short-term outcomes of a community-based intervention for overweight and obese children: The MEND 5-7 programme
Objective The aim of this study was to report outcomes of the UK service level delivery of MEND (Mind,Exercise,Nutrition...Do it!) 5-7, a multicomponent, community-based, healthy lifestyle intervention designed for overweight and obese children aged 5–7 years and their families.
Design Repeated measures.
Setting Community venues at 37 locations across the UK.
Participants 440 overweight or obese children (42% boys; mean age 6.1 years; body mass index (BMI) z-score 2.86) and their parents/carers participated in the intervention.
Intervention MEND 5-7 is a 10-week, family-based, child weight-management intervention consisting of weekly group sessions. It includes positive parenting, active play, nutrition education and behaviour change strategies. The intervention is designed to be scalable and delivered by a range of health and social care professionals.
Primary and secondary outcome measures The primary outcome was BMI z-score. Secondary outcome measures included BMI, waist circumference, waist circumference z-score, children's psychological symptoms, parenting self-efficacy, physical activity and sedentary behaviours and the proportion of parents and children eating five or more portions of fruit and vegetables.
Results 274 (62%) children were measured preintervention and post-intervention (baseline; 10-weeks). Post-intervention, mean BMI and waist circumference decreased by 0.5 kg/m2 and 0.9 cm, while z-scores decreased by 0.20 and 0.20, respectively (p<0.0001). Improvements were found in children's psychological symptoms (−1.6 units, p<0.0001), parent self-efficacy (p<0.0001), physical activity (+2.9 h/week, p<0.01), sedentary activities (−4.1 h/week, p<0.0001) and the proportion of parents and children eating five or more portions of fruit and vegetables per day (both p<0.0001). Attendance at the 10 sessions was 73% with a 70% retention rate.
Conclusions Participation in the MEND 5-7 programme was associated with beneficial changes in physical, behavioural and psychological outcomes for children with complete sets of measurement data, when implemented in UK community settings under service level conditions. Further investigation is warranted to establish if these findings are replicable under controlled conditions
Calibrating rectangular interferometer meshes with external photodetectors
Multiport interferometer meshes can be used to implement unitary transformations on input vectors of light in both the classical and quantum domain. In practice, the phase-shifters in a mesh photonic circuit must be calibrated to compensate for phase errors due to fabrication variations. Calibration using photodetectors external to the mesh has been demonstrated for triangular meshes, but not rectangular meshes. Here, we propose an algorithm for the calibration of rectangular meshes using only external photodetectors and simulate it to evaluate its feasibility
Associations between anxiety, body mass index, and sex hormones in women
Background: Several studies have shown a positive association between anxiety and obesity, particularly in women. We aimed to study whether sex hormone alterations related to obesity might play a role in this association. Patients and methods: Data for this study were obtained from a population-based cohort study (the LIFE-Adult-Study). A total of 3,124 adult women (970 premenopausal and 2,154 postmenopausal) were included into the analyses. The anxiety symptomatology was assessed using the GAD-7 questionnaire (cut-off ≥ 10 points). Sex hormones were measured from fasting serum samples. Results: We did not find significant differences in anxiety prevalence in premenopausal obese women compared with normal-weight controls (4.8% vs. 5.5%). Both obesity and anxiety symptomatology were separately associated with the same sex hormone alteration in premenopausal women: higher total testosterone level (0.97 ± 0.50 in obese vs. 0.86 ± 0.49 nmol/L in normal-weight women, p = 0.026 and 1.04 ± 0.59 in women with vs. 0.88 ± 0.49 nmol/L in women without anxiety symptomatology, p = 0.023). However, women with anxiety symptomatology had non-significantly higher estradiol levels than women without anxiety symptomatology (548.0 ± 507.6 vs. 426.2 ± 474.0 pmol/L), whereas obesity was associated with lower estradiol levels compared with those in normal-weight group (332.7 ± 386.5 vs. 470.8 ± 616.0 pmol/L). Women with anxiety symptomatology had also significantly higher testosterone and estradiol composition (p = 0.006). No associations of sex hormone levels and BMI with anxiety symptomatology in postmenopausal women were found. Conclusions: Although both obesity and anxiety symptomatology were separately associated with higher testosterone level, there was an opposite impact of anxiety and obesity on estradiol levels in premenopausal women. We did not find an evidence that the sex hormone alterations related to obesity are playing a significant role in anxiety symptomatology in premenopausal women. This could be the explanation why we did not find an association between obesity and anxiety. In postmenopausal women, other mechanisms seem to work than in the premenopausal group
After the RCT: who comes to a family-based intervention for childhood overweight or obesity when it is implemented at scale in the community?
Background: When implemented at scale, the impact on health and health inequalities of public health interventions depends on who receives them in addition to intervention effectiveness.
Methods: The MEND 7–13 (Mind, Exercise, Nutrition…Do it!) programme is a family-based weight management intervention for childhood overweight and obesity implemented at scale in the community. We compare the characteristics of children referred to the MEND programme (N=18 289 referred to 1940 programmes) with those of the population eligible for the intervention, and assess what predicts completion of the intervention.
Results: Compared to the MEND-eligible population, proportionally more children who started MEND were: obese rather than overweight excluding obese; girls; Asian; from families with a lone parent; living in less favourable socioeconomic circumstances; and living in urban rather than rural or suburban areas. Having started the programme, children were relatively less likely to complete it if they: reported ‘abnormal’ compared to ‘normal’ levels of psychological distress; were boys; were from lone parent families; lived in less favourable socioeconomic circumstances; and had participated in a relatively large MEND programme group; or where managers had run more programmes.
Conclusions: The provision and/or uptake of MEND did not appear to compromise and, if anything, promoted participation of those from disadvantaged circumstances and ethnic minority groups. However, this tendency was diminished because programme completion was less likely for those living in less favourable socioeconomic circumstances. Further research should explore how completion rates of this intervention could be improved for particular groups
Association of postpartum maternal mood with infant speech perception at 2 and 6.5 months of age
Importance: Language development builds on speech perception, with early disruptions increasing the risk for later language difficulties. Although a major postpartum depressive episode is associated with language development, this association has not been investigated among infants of mothers experiencing a depressed mood at subclinical levels after birth, even though such a mood is frequently present in the first weeks after birth. Understanding whether subclinical depressed maternal mood after birth is associated with early language development is important given opportunities of coping strategies for subclinical depressed mood.Objective: To examine whether depressed maternal mood at subclinical levels 2 months after birth is associated with infant speech perception trajectories from ages 2 to 6.5 months.Design, setting, and participants: In this longitudinal cohort study conducted between January 1, 2018, and October 31, 2019, 46 healthy, monolingual German mother-infant dyads were tested. The sample was recruited from the infants database of the Max Planck Institute for Human Cognitive and Brain Sciences. Initial statistical analysis was performed between January 1 and March 31, 2021; the moderation analysis (results reported herein) was conducted between July 1 and July 31, 2022.Exposures: Mothers reported postpartum mood via the German version of the Edinburgh Postnatal Depression Scale (higher scores indicated higher levels of depressed mood, with a cutoff of 13 points indicating a high probability of clinical depression) when their infants were 2 months old.Main outcomes and measures: Electrophysiological correlates of infant speech perception (mismatch response to speech stimuli) were tested when the infants were aged 2 months (initial assessment) and 6.5 months (follow-up).Results: A total of 46 mothers (mean [SD] age, 32.1 [3.8] years) and their 2-month-old children (mean [SD] age, 9.6 [1.2] weeks; 23 girls and 23 boys) participated at the initial assessment, and 36 mothers (mean [SD] age, 32.2 [4.1] years) and their then 6.5-month-old children (mean [SD] age, 28.4 [1.5 weeks; 18 girls and 18 boys) participated at follow-up. Moderation analyses revealed that more depressed maternal subclinical postpartum mood (mean [SD] Edinburgh Postnatal Depression Scale score, 4.8 [3.6]) was associated with weaker longitudinal changes of infants' electrophysiological brain responses to syllable pitch speech information from ages 2 to 6.5 months (coefficient: 0.68; 95% CI, 0.03-1.33; P = .04).Conclusions and relevance: The results of this cohort study suggest that infant speech perception trajectories are correlated with subclinical depressed mood in postpartum mothers. This finding lays the groundwork for future research on early support for caregivers experiencing depressed mood to have a positive association with children's language development
Mode locking using a type II multiple-quantum-well structure as a fast saturable absorber
We demonstrate the application of a type II AlGal-.xAs/AlAs multiple quantum well as a fast saturable absorber in a hybridly mode-locked dye laser. Type II multiple quantum wells are promising for this application because of the fast recovery of the saturated absorption with picosecond or even subpicosecond time constants. We obtain almost transform-limited pulses as short as 0.9 psec for a type II sample with a recovery time of 2.3 psec. Passive or hybrid (active-passive) mode locking requires saturable absorbers with recovery times Ta that are short in comparison with the recovery time rg of the saturable gain.1 2 Generally, suitable dyes are used in passive or hybrid mode-locked dye laser systems, such as DODCI in combination with Rhodamine 6G in the colliding-pulse mode-locked laser. Semiconductor materials are also attractive for saturable absorbers because of the large optical nonlinearities that can be obtained, particularly in quantum-well structures. 3 However, in high-quality materials the recovery time of the saturated absorption is quite slow owing to the long carrier recombination time constants, which are in the nanosecond range for materials such as GaAs or InP, related alloys, and quantumwell structures. Thus applications as saturable absorbers for mode locking at high repetition rates as well as applications in optical processing, where fast switching at high bit rates is required, are not always possible. To overcome this the recombination lifetime can be reduced by creation of defects, e.g., by ion bombardment, which results in an increased concentration of nonradiative centers. 2 In fact, mode locking of a GaAs semiconductor laser at a repetition rate of 2 GHz with a proton-bombarded quantum-well saturable absorber has been reported, and pulses of 1.6 psec have been achieved. 2 Much shorter pulses, down to 120 fsec, have been obtained by passive mode locking of color-center lasers with HgCdTe multiple-quantum-well (MQW) saturable absorbers. 7 The nonlinearity responsible for saturable absorption in semiconductors is due to exciton bleaching. In semiconductor quantum wells like GaAs/AlGaAs electronic states are confined in one dimension, which results in an increase of exciton binding energy and oscillator strength compared with that of bulk material. In the normal, so-called type I structures, the upper valence band and lowest conduction band states are spatially located in the material with the smaller band gap, i.e., electrons and holes are confined in the same slab, e.g., in GaAs if the type I GaAs/AlGaAs structures are considered. The recovery time of the optical nonlinearity in these type I structures is generally determined by the recombination lifetime, which is of the order of 1 nsec at room temperature. Type II structures, in contrast, are characterized by a spatial separation within the different slabs of the quantumwell structure of the upper valence band and the lowest conduction band states. The lowest-lying electronic conduction band states of type II AlxGal-,As/ AlAs MQW structures originate from X-conduction band states of the indirect-gap AlAs material 8 and thus are basically confined in the AlAs barrier material. The upper valence band states with r symmetry, however, are confined to the AlGaAs well. The absorption spectrum in these type II samples is governed by the direct optical transitions at higher energies, involving the r valence band and the X-conduction band states of Al.Gal~-As, since the oscillator strength for the indirect r-X transition is smaller by orders of magnitude. 8 Optical pump and probe experiments at the resonance peak of the lowest-lying direct heavy-hole excitonic transition reveal a partial recovery of the bleached absorption with a picosecond or even subpicosecond time constant 7 that is much 0146-9592/91/040241-03$5.00/
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