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During the last fifteen years there has been a paradigm shift in the continuum modelling of granular materials; most notably with the development of rheological models, such as the $\mu (I)$-rheology (where $\mu$ is the friction and I is the inertial number), but also with significant advances in theories for particle segregation. This paper details theoretical and numerical frameworks (based on OpenFOAM) which unify these currently disconnected endeavours. Coupling the segregation with the flow, and vice versa, is not only vital for a complete theory of granular materials, but is also beneficial for developing numerical methods to handle evolving free surfaces. This general approach is based on the partially regularized incompressible $\mu (I)$-rheology, which is coupled to the gravity-driven segregation theory of Gray & Ancey (J. Fluid Mech., vol. 678, 2011, pp. 353–588). These advection–diffusion–segregation equations describe the evolving concentrations of the constituents, which then couple back to the variable viscosity in the incompressible Navier–Stokes equations. A novel feature of this approach is that any number of differently sized phases may be included, which may have disparate frictional properties. Further inclusion of an excess air phase, which segregates away from the granular material, then allows the complex evolution of the free surface to be captured simultaneously. Three primary coupling mechanisms are identified: (i) advection of the particle concentrations by the bulk velocity, (ii) feedback of the particle-size and/or frictional properties on the bulk flow field and (iii) influence of the shear rate, pressure, gravity, particle size and particle-size ratio on the locally evolving segregation and diffusion rates. The numerical method is extensively tested in one-way coupled computations, before the fully coupled model is compared with the discrete element method simulations of Tripathi & Khakhar (Phys. Fluids, vol. 23, 2011, 113302) and used to compute the petal-like segregation pattern that spontaneously develops in a square rotating drum.
To examine the association between mealtime media use and non-HDL-cholesterol as well as other markers of cardiometabolic risk (CMR) in children.
A repeated measures study design was used to examine the association between mealtime media use and CMR outcomes. Multivariable linear regression with generalised estimating equations was used to examine the association between mealtime media use and CMR outcomes. Analyses were stratified a priori by age groups (1–4 and 5–13 years).
The TARGet Kids! Practice-based research network in Toronto, Canada.
2117 children aged 1–13 years were included in the analysis.
After adjusting for covariates, there was no evidence that total mealtime media use was associated with non-HDL-cholesterol in 1–4 year olds (P = 0·10) or 5–13 year olds (P = 0·29). Each additional meal with media per week was associated with decreased HDL-cholesterol in 5–13 year olds (−0·006 mmol/l; 95 % CI −0·009, −0·002; P = 0·003) and log-TAG in 1–4 year olds (β = −0·004; 95 % CI −0·008, −0·00009; P = 0·04). Media use during breakfast was associated with decreased HDL-cholesterol in 5–13 year olds (−0·012 mmol/l; 95 % CI −0·02, −0·004; P = 0·002), while media during lunch was associated with decreased log-TAG (−0·01 mmol/l; 95 % CI −0·03, −0·002; P = 0·03) in children aged 1–4 years. Total mealtime media use was not associated with total cholesterol, glucose or insulin in either age group.
Mealtime media use may be associated with unfavourable lipid profiles through effects on HDL-cholesterol in school-aged children but likely not in pre-schoolers.
To evaluate the association between the age of cow milk introduction and childhood growth.
A secondary analysis of a prospective cohort study.
Healthy children <5 years of age enrolled in the TARGet Kids! practice-based research network. The primary exposure was the age of cow milk introduction. The primary outcome was height-for-age z-score. Secondary outcomes were volume of cow milk consumed (cups/d) and BMI z-score. Outcomes were measured at the last visit before 5 years of age. Multiple linear regression was used to examine these relationships.
Among 1981 children, introduction of cow milk at a younger age was associated with greater height by 3–5 years of age (P < 0·001). Each month earlier that cow milk was introduced was associated with 0·03 higher height-for-age z-score unit (95 % CI –0·05, –0·02) or 0·1 cm (95 % CI –0·15, –0·12 cm). At 4 years of age, the height difference between a child introduced to cow milk at 9 v. 12 months was 0·4 cm (95 % CI –0·45, –0·35 cm). There was no association between the timing of cow milk introduction and volume of cow milk consumed per day or BMI z-score.
Earlier introduction of cow milk was associated with greater height but not with weight status in children aged 3–5 years. Further research is needed to understand the casual relationship between earlier cow milk consumption and childhood height. These findings may be important for paediatricians and parents when considering when to introduce cow milk.
In a RCT of family psychoeducation, 47 carers of 34 patients were allocated to one of three groups; Multifamily Group Psychoeducation, Solution Focussed Group Therapy or Treatment as Usual. Carers in both the MFGP intervention and the SFGP arm demonstrated greater knowledge and reduction in burden than those in the TAU arm.
There are no evidence-based treatments for severe and enduring anorexia nervosa.
To evaluate the relative efficacy of Cognitive Behavioral Therapy (CBT) and Specialist Supportive Clinical Management (SSCM) for adults with severe and enduring anorexia nervosa.
Randomised controlled trial.
Sixty-three participants aged 18 and over (range 20-62) with a DSM-IV diagnosis of anorexia nervosa with at least a seven year illness history.
Thirty outpatient visits over 8 months. Participants were assessed at baseline, end of treatment (EOT), and 6-month and 12-month post-treatment follow-up. At EOP and follow-up, both groups improved significantly on the majority of outcome measures. However, there were no differences between treatment groups at EOT. At 6- and 12-month follow-up, analyses indicate greater improvement for those in CBT compared to SSCM. At 6-month follow-up, CBT participants had higher scores on the social adjustment scale (p = .038), and at 12-month they reported lower eating disorder examination global score (p = .004), and higher readiness for recovery (p = .013) compared to SSCM.
Patients with severe and enduring anorexia nervosa can make significant and meaningful improvements with therapy. CBT shows significant advantage over SSCM in terms of social adjustment, core eating pathology, and readiness for change over time.
Nutritional rehabilitation in anorexia nervosa (AN) is impeded by fear of food, eating and change leading to treatment resistance. Oxytocin exerts prosocial effects on anxiolysis, fear modulation, trust and brain plasticity.
A placebo-controlled RCT examined the effects of self-administered intranasal oxytocin (IN-OT) in AN patients.
To ascertain whether single and repeated doses of IN-OT enhance treatment in AN.
Female AN patients self-administered twice daily 18IU IN-OT (n = 21) or placebo (n = 21) for 4–6 weeks during hospital treatment. Weight and BMI were measured at baseline and after treatment. The Eating Disorders Examination (EDE) was the primary outcome measure. Cognitive rigidity was compared between groups after four weeks repeated dosing. The effects of the first and last doses of IN-OT versus placebo, on salivary cortisol before a high-energy afternoon snack, were compared.
Weight gain was similar in IN-OT and placebo groups. Only the EDE eating concern subscale score was significantly lower after 4–6 weeks (mean 35 days) of IN-OT (p = 0.006). Anticipatory levels of salivary cortisol fell from baseline after the initial dose in contrast to the placebo group where levels increased. After four weeks IN-OT, salivary cortisol was significantly lower (p = 0.023) overall with little anticipatory increase compared to placebo. There were no differences in anxiety scores. Cognitive rigidity was significantly lower in the IN-OT group (p= 0.043)
Self-administered IN-OT might enhance nutritional rehabilitation in AN by reducing eating concern and cognitive rigidity. Lower salivary cortisol before a high-energy snack, suggests reduction of fear rather than anxiety.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
Consensus guidelines recommend that children consume reduced-fat (0·1–2 %) cow’s milk at age 2 years to reduce the risk of obesity. Behaviours and perspectives of parents and physicians about cow’s milk fat for children are unknown. Objectives were to: (i) understand what cow’s milk fat recommendations physicians provide to 2-year-old children; (ii) assess the acceptability of reduced-fat v. whole cow’s milk in children’s diets by parents and physicians; and (iii) explore attitudes and perceptions about cow’s milk fat for children.
Online questionnaires and individual interviews were conducted. Questionnaire data were analysed using descriptive statistics. Interview transcripts were analysed using a general inductive approach and thematic analysis.
The TARGet Kids! practice-based research network in Toronto, Canada.
Questionnaire respondents included fifty parents and fifteen physicians; individual interviews were conducted with with fourteen parents and twelve physicians.
Physicians provided various milk fat recommendations for 2-year-old children. Parents also provided different cow’s milks: eighteen (36 %) provided whole milk and twenty-nine (58 %) provided reduced-fat milk. Analysis of qualitative interviews revealed three themes: (i) healthy eating behaviours, (ii) trustworthy nutrition information and (iii) importance of dietary fat for children.
Parents provide, and physicians recommend, a variety of cow’s milks for children and hold mixed interpretations of the role of cow’s milk fat in children’s diets. Clarity about its effect on child adiposity is needed to help make informed decisions about cow’s milk fat for children.
Upper respiratory tract infections (URTI) are the most common and costly condition of childhood. Low vitamin D levels have been hypothesized as a risk factor for URTI. The primary objective was to determine if serum vitamin D levels were associated with health-service utilization (HSU) for URTI including hospital admission, emergency department visits and outpatient sick visits. The secondary objectives were to determine whether oral vitamin D supplementation in pregnancy or childhood was associated with HSU for URTI.
Cohort study. HSU was determined by linking each child’s provincial health insurance number to health administrative databases. Multivariable quasi Poisson regression was used to evaluate the association between 25-hydroxyvitamin D, vitamin D supplementation and HSU for URTI.
Children participating in the TARGet Kids! network between 2008 and 2013.
Healthy children aged 0–5 years (n 4962) were included; 52 % were male and mean 25-hydroxyvitamin D was 84 nmol/l (range 11–355 nmol/l). There were 105 (2 %), 721 (15 %) and 3218 (65 %) children with at least one hospital admission, emergency department visit or outpatient sick visit for URTI, respectively. There were no statistically significant associations between 25-hydroxyvitamin D or vitamin D supplementation and HSU for URTI.
A clinically meaningful association between vitamin D (continuously and dichotomized at <50 and <75 nmol/l) and HSU for URTI was not identified. While vitamin D may have other benefits for health, reducing HSU for URTI does not appear to be one of them.
Timely recruitment of population controls in infectious disease outbreak investigations is challenging. We evaluated the timeliness and cost of using a market research panel as a sampling frame for recruiting controls in a case-control study during an outbreak of Salmonella Mikawasima in the UK in 2013. We deployed a web-survey by email to targeted members of a market research panel (panel controls) in parallel to the outbreak control team interviewing randomly selected public health staff by telephone and completing paper-based questionnaires (staff controls). Recruitment and completion of exposure history web-surveys for panel controls (n = 123) took 14 h compared to 15 days for staff controls (n = 82). The average staff-time cost per questionnaire for staff controls was £13·13 compared to an invoiced cost of £3·60 per panel control. Differences in the distribution of some exposures existed between these control groups but case-control studies using each group found that illness was associated with consumption of chicken outside of the home and chicken from local butchers. Recruiting market research panel controls offers time and resource savings. More rapid investigations would enable more prompt implementation of control measures. We recommend that this method of recruiting controls is considered in future investigations and assessed further to better understand strengths and limitations.
Fe-deficiency anaemia (IDA) occurs in 1–2 % of infants in developed countries, peaks at 1–3 years of age and is associated with later cognitive deficits. The objectives of the present study were to describe the characteristics of young children with severe IDA and examine modifiable risk factors in a developed-country setting.
Two prospective samples: a national surveillance programme sample and a regional longitudinal study sample.
Two samples of young children recruited from community-based health-care practices: a national sample with severe anaemia (Hb<80 g/l) due to Fe deficiency and a regional sample with non-anaemic Fe sufficiency.
Children with severe IDA (n 201, mean Hb 55·1 g/l) experienced substantial morbidity (including developmental delay, heart failure, cerebral thrombosis) and health-care utilization (including a 42 % hospitalization rate). Compared with children with Fe sufficiency (n 597, mean Hb 122·4 g/l), children with severe IDA consumed a larger volume of cow’s milk daily (median 1065 ml v. 500 ml, P<0·001) and were more likely to be using a bottle during the day (78 % v. 43 %, OR=6·0; 95 % CI 4·0, 8·9) and also in bed (60 % v. 21 %, OR=6·5; 95 % CI 4·4, 9·5).
Severe IDA is associated with substantial morbidity and may be preventable. Three potentially modifiable feeding practices are associated with IDA: (i) cow’s milk consumption greater than 500 ml/d; (ii) daytime bottle use beyond 12 months of age; and (iii) bottle use in bed. These feeding practices should be highlighted in future recommendations for public health and primary-care practitioners.
The association between vitamin D and wheezing in early childhood is unclear. The primary objective of this study was to evaluate the association between vitamin D exposure, during both pregnancy and childhood, and early childhood wheezing. Secondary objectives were to evaluate the associations between vitamin D exposures and asthma and wheezing severity. We conducted a cohort study of children (0–5 years) recruited from 2008 to 2013 through the TARGet Kids! primary-care research network. Vitamin D exposures included maternal vitamin D supplement use during pregnancy, child vitamin D supplementation and children’s 25-hydroxyvitamin D (25(OH)D) concentrations. The outcomes measured were parent-reported childhood wheezing, diagnosed asthma and wheezing severity. Vitamin D supplement and wheezing data were available for 2478 children, and blood samples were available for 1275 children. Adjusted odds ratios (aOR) were estimated using logistic regression adjusted for age, sex, ethnicity, body mass index, birth weight, outdoor play, breastfeeding duration, daycare status, parental smoking and family history of asthma. Vitamin D supplementation during pregnancy was associated with lower odds of childhood wheezing (aOR=0.65; 95% CI: 0.46–0.93). In early childhood, neither 25(OH)D (aOR per 10 nmol/l=1.01; 95% CI: 0.96–1.06) nor vitamin D supplementation (aOR=1.00; 95% CI: 0.81–1.23) was associated with wheezing. No significant associations were observed with diagnosed asthma or wheezing severity. Vitamin D supplementation during pregnancy was associated with reduced odds of wheezing, but child vitamin D supplementation and childhood 25(OH)D were not associated with reduced wheezing. The timing of exposure may be important in understanding the association between vitamin D and childhood wheezing.
To determine if children aged 1–6 years from non-Western immigrant families have lower serum 25-hydroxyvitamin D (25(OH)D) levels than children from Western-born families and examine which factors influence this relationship.
Healthy children (n 1540) recruited through the TARGet Kids! practice-based research network. Serum 25(OH)D concentrations of non-Western immigrants were compared with those of children from Western-born families. Children from non-Western immigrant families were defined as those born, or their parents were born, outside a Western country. Univariate and multiple linear regression analyses were used to identify factors which might influence this relationship.
Median age was 36 months, 51 % were male, 86 % had ‘light’ skin pigmentation, 55 % took vitamin D supplements, mean cow's milk intake was 1·8 cups/d and 27 % were non-Western immigrants. Median serum 25(OH)D concentration was 83 nmol/l, with 5 % having 25(OH)D < 50 nmol/l. Univariable analysis revealed that non-Western immigrant children had serum 25(OH)D lower by 4 (95 % CI 1·3, 8·0) nmol/l (P = 0·006) and increased odds of 25(OH)D < 50 nmol/l (OR = 1·9; 95 % CI 1·3, 2·9). After adjustment for known vitamin D determinants the observed difference attenuated to 0·04 (95 % CI −4·8, 4·8) nmol/l (P = 0·99), with higher cow's milk intake (P < 0·0001), vitamin D supplementation (P < 0·0001), summer season (P = 0·008) and increased age (P = 0·04) being statistically significant covariates. Vitamin D supplementation was the strongest explanatory factor of the observed difference.
There is an association between non-Western immigration and lower 25(OH)D in early childhood. This difference appears related to known vitamin D determinants, primarily vitamin D supplementation, representing opportunities for intervention.
There are no evidence-based treatments for severe and enduring anorexia nervosa (SE-AN). This study evaluated the relative efficacy of cognitive behavioral therapy (CBT-AN) and specialist supportive clinical management (SSCM) for adults with SE-AN.
Sixty-three participants with a diagnosis of AN, who had at least a 7-year illness history, were treated in a multi-site randomized controlled trial (RCT). During 30 out-patient visits spread over 8 months, they received either CBT-AN or SSCM, both modified for SE-AN. Participants were assessed at baseline, end of treatment (EOT), and at 6- and 12-month post-treatment follow-ups. The main outcome measures were quality of life, mood disorder symptoms and social adjustment. Weight, eating disorder (ED) psychopathology, motivation for change and health-care burden were secondary outcomes.
Thirty-one participants were randomized to CBT-AN and 32 to SSCM with a retention rate of 85% achieved at the end of the study. At EOT and follow-up, both groups showed significant improvement. There were no differences between treatment groups at EOT. At the 6-month follow-up, CBT-AN participants had higher scores on the Weissman Social Adjustment Scale (WSAS; p = 0.038) and at 12 months they had lower Eating Disorder Examination (EDE) global scores (p = 0.004) and higher readiness for recovery (p = 0.013) compared to SSCM.
Patients with SE-AN can make meaningful improvements with both therapies. Both treatments were acceptable and high retention rates at follow-up were achieved. Between-group differences at follow-up were consistent with the nature of the treatments given.
Two different atmospheric pressure microplasma systems are discussed and used for the synthesis and surface engineering of a range of nanomaterials. Specifically a gas-phase approach from vaporized tetramethylsilane has been used to synthesize silicon carbide nanoparticles with diameters below 10 nm. A different microplasma system that interfaces with a liquid solution has then been used for the synthesis of surfactant-free electrically stabilized gold nanoparticles with varying size. A similar microplasma-liquid system has been finally successfully used to tailor surface properties of silicon nanoparticles and to reduce graphene oxide into graphene. The synthesis and surface engineering mechanisms are also discussed.
To identify child and parental factors associated with screen time in 3-year-old children.
Participants were recruited from a large primary-care paediatric group practice in Toronto, Canada.
Healthy 3-year-old children were included. A questionnaire was completed by their parents on screen time. Descriptive statistics and linear regression models were used to assess associations between child screen time and selected factors. Multivariable models included factors from the univariate analysis with P < 0·1. Estimated effects and 95 % CI are reported.
A total of 157 children were enrolled (91 % recruitment). The mean screen time per weekday was 104 min (similar for weekend day). In all, 10 % of children had a television (TV) in their bedroom; 59 % consumed at least one meal while watching TV; and 81 % of parents had household rules about screen time. Controlling for maternal education and age, eating lunch and dinner in front of the screen and mother being employed were associated with an increase in child weekday screen time of 96 (95 % CI 30, 192), 42 (95 % CI 12, 90) and 36 (95 % CI 6, 72) min/d, respectively. Eating lunch in front of the screen and an increase of 1 h of parental screen time were associated with an increase of 78 (95 % CI 36, 132) and 12 (95 % CI 6, 18) min/d in child weekend screen time. Family rules decreased child weekend screen time by 30 (95 % CI 6, 54) min/d.
Interventions that include these important parental factors should be evaluated for their effectiveness in reducing screen time.
Artificial chick shelters might improve productivity of beach-nesting birds threatened by anthropogenic disturbance. We investigated the efficacy of three different chick shelter designs against four criteria: accessibility to chicks over time, thermal insulation, conspicuousness to beach-goers, and practicality (cost and ease of transport). One design (‘A-frame’) was selected because it offered the greatest thermal insulation, was the least conspicuous, most cost effective, and performed equally well in terms of accessibility. We deployed these artificial shelters on Hooded Plover Thinornis rubricollis territories where broods were present (n = 11), and compared the behaviour and survival rate of chicks to that at control sites (n = 10). We were unable to discern any difference in the behaviour of broods when artificial shelters were available. However, the survival rate of chicks to fledging was 71.8% higher where an artificial shelter was provided (n = 21 broods). This was validated by analysing data from a larger sample of broods monitored as part of an active volunteer-based management programme; shelters conferred a 42.8% increase in survival to fledging (n = 81 broods). Thus, artificial shelters have the potential to increase survival rates of threatened shorebird chicks, though the mechanisms through which survival is increased require further investigation.