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The stars of the Milky Way carry the chemical history of our Galaxy in their atmospheres as they journey through its vast expanse. Like barcodes, we can extract the chemical fingerprints of stars from high-resolution spectroscopy. The fourth data release (DR4) of the Galactic Archaeology with HERMES (GALAH) Survey, based on a decade of observations, provides the chemical abundances of up to 32 elements for 917 588 stars that also have exquisite astrometric data from the Gaia satellite. For the first time, these elements include life-essential nitrogen to complement carbon, and oxygen as well as more measurements of rare-earth elements critical to modern-life electronics, offering unparalleled insights into the chemical composition of the Milky Way. For this release, we use neural networks to simultaneously fit stellar parameters and abundances across the whole wavelength range, leveraging synthetic grids computed with Spectroscopy Made Easy. These grids account for atomic line formation in non-local thermodynamic equilibrium for 14 elements. In a two-iteration process, we first fit stellar labels to all 1 085 520 spectra, then co-add repeated observations and refine these labels using astrometric data from Gaia and 2MASS photometry, improving the accuracy and precision of stellar parameters and abundances. Our validation thoroughly assesses the reliability of spectroscopic measurements and highlights key caveats. GALAH DR4 represents yet another milestone in Galactic archaeology, combining detailed chemical compositions from multiple nucleosynthetic channels with kinematic information and age estimates. The resulting dataset, covering nearly a million stars, opens new avenues for understanding not only the chemical and dynamical history of the Milky Way but also the broader questions of the origin of elements and the evolution of planets, stars, and galaxies.
Dense suspensions of solid particles in viscous liquid are ubiquitous in both industry and nature, and there is a clear need for efficient numerical routines to simulate their rheology and microstructure. Particles of micron size present a particular challenge: at low shear rates, colloidal interactions control their dynamics while at high rates, granular-like contacts dominate. While there are established particle-based simulation schemes for large-scale non-Brownian suspensions using only pairwise lubrication and contact forces, common schemes for colloidal suspensions generally are more computationally costly and thus restricted to relatively small system sizes. Here, we present a minimal particle-based numerical model for dense colloidal suspensions that incorporates Brownian forces in pairwise form alongside contact and lubrication forces. We show that this scheme reproduces key features of dense suspension rheology near the colloidal-to-granular transition, including both shear thinning due to entropic forces at low rates and shear thickening at high rates due to contact formation. This scheme is implemented in LAMMPS, a widely used open source code for parallelised particle-based simulations, with a runtime that scales linearly with the number of particles, making it amenable for large-scale simulations.
Menu labelling has been identified as a potential strategy to help individuals make healthier choices when eating out. Although adolescents eat out often, little research involving menu labelling has been conducted with this population. The objectives of the present study were to: (i) gather qualitative information from adolescents regarding use of menu labels when eating out; (ii) gather adolescents’ suggestions for optimal ways to design menu labels; and (iii) examine differences between adolescents living in communities of different socio-economic status.
Design
Qualitative. Five focus groups of five to ten participants.
Setting
Austin, TX, USA, 2012.
Subjects
Forty-one adolescents living in diverse communities recruited using a snowballing technique at public and private recreation centres (twenty-four females; twenty-two African American).
Results
Participants reported that menu labelling, in general, does not influence food selections when eating out. Among participants living in low-income communities, food purchases were based on price, taste and familiarity. Among participants living in high-income areas, food purchases were based on quality and ability to satiate (among boys). According to participants, effective ways to present menu labels are by matching calorie levels with physical activity equivalents or through simple graphics.
Conclusions
For adolescents, providing menu labels in their current format may not be an effective strategy to increase healthy food selection. Given that the current menu label format has been set by federal policy in the USA cannot be easily changed, research to determine how this format can be best presented or enhanced so that it can have an impact on all US sub-populations is warranted.
To determine the prospective relationship between changes in sugar-sweetened beverage (SSB) intake and central adiposity in older children.
Design
Dietary intakes of children were obtained by 3 d food records at ages 10 and 13 years. Waist circumference (WC) and weight and height to determine BMI were measured at 10 and 13 years and total body fat mass (TBFM) at 13 years by dual-energy X-ray absorptiometry. Analyses were conducted using multivariable linear regression. Reporting errors were measured and participants were categorized as under-, plausible and over-reporters of dietary intakes.
Setting
Community-based British cohort of children participating in the Avon Longitudinal Study of Parents and Children.
Results
Among 2455 older children, increased SSB consumption from ages 10 to 13 years was associated with higher WC (standardized β=0·020, P=0·19), BMI (β=0·028, P=0·03) and TBFM (β=0·017, P=0·20) at 13 years. Effects were strengthened among plausible dietary reporters (n 1059): WC (β=0·097, P<0·001), BMI (β=0·074, P<0·001) and TBFM (β=0·065, P=0·003). The association between change in SSB and WC was weakened, but remained statistically significant after accounting for BMI (β=0·042, P=0·02) and TBFM (β=0·048, P=0·01).
Conclusions
Higher consumption of SSB from ages 10 to 13 years was associated with a larger WC at age 13 years independent of differences in total adiposity. Accounting for dietary reporting errors strengthened associations. Our findings further support recommendations to limit intakes of SSB to reduce excess weight gain in children and suggest that SSB have an additional deleterious effect on central adiposity.
We study the stellar content of three galactic bulges with the high resolution gratings (R=7000) of the WiFeS integral field unit in order to better understand their formation and evolution. In all cases we find that at least 50% of the stellar mass already existed 12 Gyrs ago, more than currently predicted by simulations. A younger component (age between ∼1 to ∼8 Gyrs) is also prominent and its present day distribution seems to be much more affected by morphological structures, especially bars, than the older one. This in-depth analysis supports the notion of increasing complexity in bulges which cannot be achieved by mergers alone, but requires a non-negligible contribution from secular evolution.
For diagnostic purposes, the nine symptoms that compose the DSM-5 criteria for major depressive disorder (MDD) are assumed to be interchangeable indicators of one underlying disorder, implying that they should all have similar risk factors. The present study investigates this hypothesis, using a population cohort that shifts from low to elevated depression levels.
Method
We assessed the nine DSM-5 MDD criterion symptoms (using the Patient Health Questionnaire; PHQ-9) and seven depression risk factors (personal and family MDD history, sex, childhood stress, neuroticism, work hours, and stressful life events) in a longitudinal study of medical interns prior to and throughout internship (n = 1289). We tested whether risk factors varied across symptoms, and whether a latent disease model could account for heterogeneity between symptoms.
Results
All MDD symptoms increased significantly during residency training. Four risk factors predicted increases in unique subsets of PHQ-9 symptoms over time (depression history, childhood stress, sex, and stressful life events), whereas neuroticism and work hours predicted increases in all symptoms, albeit to varying magnitudes. MDD family history did not predict increases in any symptom. The strong heterogeneity of associations persisted after controlling for a latent depression factor.
Conclusions
The influence of risk factors varies substantially across DSM depression criterion symptoms. As symptoms are etiologically heterogeneous, considering individual symptoms in addition to depression diagnosis might offer important insights obfuscated by symptom sum scores.
Background: Little research has examined the diagnostic utility and factor structure of commonly used posttraumatic stress disorder (PTSD) assessment instruments in older persons.
Methods: A total of 206 adults aged 60 or older (mean age = 69 years; range = 60–92), who resided in the Galveston Bay area when Hurricane Ike struck in September 2008, completed a computer-assisted telephone interview two–five months after this disaster. Using the PTSD Checklist (PCL), PTSD symptoms were assessed related both to this disaster and to participants’ worst lifetime traumatic event. Total PCL scores were compared to PCL-based, Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV)-derived probable diagnoses of PTSD to determine optimal cut scores. Confirmatory factor analyses (CFAs) were conducted to evaluate PTSD symptom structure.
Results: Receiver operating characteristic analyses indicated that a PCL score of 39 achieved optimal sensitivity and specificity in assessing a PCL-based, algorithm-derived DSM-IV diagnosis of worst event-related PTSD; and that a score of 37 optimally assessed probable Ike-related PTSD. CFAs revealed that a recently proposed five-factor model – comprised of re-experiencing, avoidance, numbing, dysphoric arousal, and anxious arousal factors – provided a better fitting representation of both worst event- and disaster-related PTSD symptoms than alternative models. Current Ike-related anxious arousal symptoms demonstrated a significantly stronger association with current generalized anxiety than depressive symptoms, thereby supporting the construct validity of this five-factor model of PTSD symptomatology.
Conclusions: A PCL score of 37 to 39 may help identify probable PTSD in older persons. The expression of PTSD symptoms in older adults may be best characterized by a recently proposed five-factor model with distinct dysphoric arousal and anxious arousal clusters.
To examine the associations between maternal education level and diet in 10-year-old children.
Design
Three-day diet diaries (child completed with parental help) were collected. Height and weight were measured in research clinics. Maternal education level was derived from a questionnaire completed during pregnancy and classified into low, medium or high. One-way ANOVA was undertaken to compare maternal education groups for nutrient intakes and the Kruskal–Wallis test used for food consumption.
Setting
Avon Longitudinal Study of Parents and Children (ALSPAC), Bristol, UK.
Subjects
Children (n 7474) who provided dietary data at age 10 years.
Results
A large proportion (60 %) of the sample was classified as plausible reporters, with under-reporting accounting for 36 %. No clear differences were found for intakes of energy or macronutrients between maternal education groups for plausible reporters. However, there were marked differences in micronutrient intakes especially for vitamin C, retinol equivalents and folate, highlighting lower diet quality with lower maternal education level. Intakes of fruit and vegetables showed a positive gradient with increasing maternal education (57 % v. 79 % consumed fresh fruit in low and high educational groups, respectively). A trend towards higher intake in the lower educated group was shown for less healthy foods (meat pies P < 0·001; sausages, burgers and kebabs P < 0·001).
Conclusions
The quality of children's diet at 10 years was related to maternal education level. Lower maternal education was associated with less healthy food choices that could be detrimental to health. Further research is needed to establish if these associations can be explained by other socio-economic factors.
Previous research suggests that n-3 PUFA may play a role in bone health. The present analysis aimed to investigate the impact of n-3 PUFA supplementation on bone resorption in adult men and women. Serum samples from 113 mild–moderately depressed individuals (twenty-six males and eighty-seven females, aged 18–67 years) randomised to receive 1·48 g EPA+DHA/d (n 53) or placebo (n 60) for 12 weeks as part of a large recent randomised controlled trial were assayed for n-3 PUFA status and a bone resorption marker, C-terminal cross-linking telopeptide of type 1 collagen (β-CTX). Regression analyses revealed that n-3 PUFA status following supplementation was associated with randomisation (placebo/n-3 PUFA) (B = 3·25, 95 % CI 2·60, 3·91, P < 0·01). However, β-CTX status following supplementation was not associated with randomisation (B = − 0·01, 95 % CI − 0·03, 0·04). Change in β-CTX status was also not associated with change in n-3 PUFA status (B = − 0·002, 95 % CI − 0·01, 0·01). These findings provide no evidence for an association between n-3 PUFA supplementation (1·48 g EPA+DHA/d) for 12 weeks and bone resorption in humans assessed by β-CTX, and suggest that n-3 PUFA supplementation may be unlikely to be of benefit in preventing bone loss.
To investigate associations between dietary intakes throughout childhood and age at menarche, a possible indicator of future risk of disease, in a contemporary cohort of British girls.
Design
Diet was assessed by FFQ at 3 and 7 years of age, and by a 3 d unweighed food diary at 10 years. Age at menarche was categorised as before or after 12 years 8 months, a point close to the median age in this cohort.
Setting
Bristol, South-West England.
Subjects
Girls (n 3298) participating in the Avon Longitudinal Study of Parents and Children.
Results
Higher energy intakes at 10 years were positively associated with the early occurrence of menarche, but this association was removed on adjusting for body size. Total and animal protein intakes at 3 and 7 years were positively associated with age at menarche ≤12 years 8 months (adjusted OR for a 1 sd increase in protein at 7 years: 1·14 (95 % CI 1·04, 1·26)). Higher PUFA intakes at 3 and 7 years were also positively associated with early occurrence of menarche. Meat intake at 3 and 7 years was strongly positively associated with reaching menarche by 12 years 8 months (OR for menarche in the highest v. lowest category of meat consumption at 7 years: 1·75 (95 % CI 1·25, 2·44)).
Conclusions
These data suggest that higher intakes of protein and meat in early to mid-childhood may lead to earlier menarche. This may have implications for the lifetime risk of breast cancer and osteoporosis.
Associations between diet and physical activity may identify behaviours that could be changed together to prevent childhood obesity. The present study examines associations between physical activity and obesogenic dietary behaviours in a large UK adolescent cohort.
Design
Cross-sectional analysis of a UK cohort. Adolescents aged 10–11 years completed three 1 d diet diaries. Average daily energy consumption, percentage energy from fat and carbohydrate, energy density and grams of fruit and vegetables were estimated. To assess physical activity participants wore an accelerometer for three or more days. Regression models were run by sex to examine the extent to which dietary variables predicted physical activity before and after controlling for pubertal status, maternal education and adiposity.
Setting
The Avon Longitudinal Study of Parents and Children (ALSPAC), south-west England.
Subjects
Adolescents who provided diet data at age 10 years and physical activity data at age 11 years.
Results
Among boys, percentage energy from fat was consistently negatively associated with accelerometer-determined indicators of physical activity (standardized beta (β) = −0·055 to −0·101, P < 0·05) while total energy (β = 0·066 to 0·091, P < 0·05) and percentage energy from carbohydrate (β = 0·054 to 0·106, P < 0·05) were positively associated before and after adjustment for confounders. For girls fruit and vegetable intake was consistently positively associated with physical activity (β = 0·056 to 0·074, P < 0·005). However all associations were weak. Associations were broadly comparable when participants with non-plausible dietary reports were included or excluded from the analyses.
Conclusions
Obesogenic diet and physical activity behaviours were weakly associated, suggesting that interventions should focus on implementing strategies that are independently successful at changing diet or physical activity behaviours either separately or in combination.
Selected biochemical evidence suggests a potential role for n-3 long-chain PUFA (n-3PUFA) in the regulation of mood and behaviour. The present paper reviews the relevant evidence, to date, from epidemiological studies, clinical studies and intervention trials. Most evidence is available investigating a role for n-3PUFA in depression, depressive illness and suicidal behaviour, but work is also available on anxiety and anxiety-related disorders, fatigue and fatigue-related disorders, aggression, hostility and anti-social behaviour, inattention, impulsivity and attention deficit hyperactivity disorder and schizophrenic disorders. For all these aspects of mood and behaviour, the evidence available is currently limited and highly inconsistent, both in terms of study methodology and study findings. There is a clear need for further work in this area.
Low dietary intakes of the n-3 long-chain PUFA (LCPUFA) EPA and DHA are thought to be associated with increased risk for a variety of adverse outcomes, including some psychiatric disorders. Evidence from observational and intervention studies for a role of n-3 LCPUFA in depression is mixed, with some support for a benefit of EPA and/or DHA in major depressive illness. The present study was a double-blind randomised controlled trial that evaluated the effects of EPA+DHA supplementation (1·5 g/d) on mood and cognitive function in mild to moderately depressed individuals. Of 218 participants who entered the trial, 190 completed the planned 12 weeks intervention. Compliance, confirmed by plasma fatty acid concentrations, was good, but there was no evidence of a difference between supplemented and placebo groups in the primary outcome – namely, the depression subscale of the Depression Anxiety and Stress Scales at 12 weeks. Mean depression score was 8·4 for the EPA+DHA group and 9·6 for the placebo group, with an adjusted difference of − 1·0 (95 % CI − 2·8, 0·8; P = 0·27). Other measures of mood, mental health and cognitive function, including Beck Depression Inventory score and attentional bias toward threat words, were similarly little affected by the intervention. In conclusion, substantially increasing EPA+DHA intake for 3 months was found not to have beneficial or harmful effects on mood in mild to moderate depression. Adding the present result to a meta-analysis of previous relevant randomised controlled trial results confirmed an overall negligible benefit of n-3 LCPUFA supplementation for depressed mood.