Nanoscale LiZnN - Luminescent Half-Heusler Quantum Dots.

Colloidal semiconductor quantum dots are a well-established technology, with numerous materials available either commercially or through the vast body of literature. The prevalent materials are cadmium-based and are unlikely to find general acceptance in most applications. While the III-V family of materials is a likely substitute, issues remain about its long-term suitability, and other earth-abundant materials are being explored. In this report, we highlight a nanoscale half-Heusler semiconductor, LiZnN, composed of readily available elements as a potential alternative system to luminescent II-VI and III-V nanoparticle quantum dots.

A new genus and species of sand-hopper, Mauritiorchestia fayetta gen. nov., sp. nov. (Amphipoda, Talitridae) from Mauritius.

A new genus and species, Mauritiorchestia fayetta gen. nov., sp. nov., of talitrid amphipod is described from beaches in Mauritius. Mauritiorchestia differs significantly from the closely related genus Platorchestia in the maxilla 1 palp (absent in Mauritiorchestia, vestigial in Platorchestia) and in the dactylus of gnathopod 1 (simplidactylate in Mauritiorchestia, cuspidactylate in Platorchestia).

UK COVID-19 lockdown: 100 days of air pollution reduction?

On the 23 March 2020, a country-wide COVID-19 lockdown was imposed on the UK. The following 100 days saw anthropogenic movements quickly halt, before slowly easing back to a "new" normality. In this short communication, we use data from official UK air-quality sensors (DEFRA AURN) and the UK Met Office stations to show how lockdown measures affected air quality in the UK. We compare the 100 days post-lockdown (23 March to 30 June 2020) with the same period from the previous 7 years. We find, as shown in numerous studies of other countries, the nitrogen oxides levels across the country dropped substantially (∼ 50%). However, we also find the ozone levels increased (∼ 10%), and the levels of sulphur dioxide more than doubled across the country. These changes, driven by a complex balance in the air chemistry near the surface, may reflect the influence of low humidity as suggested by Met Office data, and potentially, the reduction of nitrogen oxides and their interactions with multiple pollutants.

Cardiac biomarkers of disordered eating as a function of diagnostic subtypes.

OBJECTIVE: The purpose of this study was to identify cardiac biomarkers of disordered eating as a function of diagnostic subtype as assessed via self-report inventory. METHOD: Mean heart rate (HR), systolic and diastolic blood pressure, mean R wave amplitude (mV), mean T wave amplitude (mV), QTc interval (sec), Tpeak-Tend interval prolongation (sec), QTc interval prolongation (sec), QRS prolongation (sec), and spectral indicators of cardiac dysfunction (LF/HF spectral ratio, HF spectral power) were assessed via electrocardiography among women with no eating disorder symptoms (n = 32), subclinical eating disorder symptoms (n = 92), anorexia nervosa (n = 7), bulimia nervosa (n = 89), binge eating disorder (BED: n = 20), and other specified feeding and eating disorders (OSFED: n = 19). RESULTS: MANOVA results showed statistically significant group differences. Follow-up tests revealed significantly decreased mean R wave amplitude among participants with self-indicated clinical (bulimia nervosa, binge eating disorder) and subclinical forms of disordered eating compared to asymptomatic controls. DISCUSSION: Results suggest decreased mean R wave amplitude is a promising cardiac biomarker of disordered eating.

Associations between food environment typologies and body mass index: Evidence from Yorkshire, England.

International research linking food outlets and body mass index (BMI) is largely cross-sectional, yielding inconsistent findings. However, addressing the exposure of food outlets is increasingly considered as an important adult obesity prevention strategy. Our study investigates associations between baseline food environment types and change in BMI over time. Survey data were used from the Yorkshire Health Study (n=8,864; wave one: 2010-2012, wave two: 2013-2015) for adults aged 18-86. BMI was calculated using self-reported height (cm) and weight (kg). Restaurants, cafés, fast-food, speciality, convenience and large supermarkets were identified from the Ordnance Survey Point of Interest database within 1600m radial buffer of home postcodes. K-means cluster analysis developed food environment typologies based on food outlets and population density. Large supermarkets, restaurants, cafés, fast-food, speciality and convenience food outlets all clustered together to some extent. Three neighbourhood typologies were identified. However, multilevel models revealed that relative to cluster one all were unrelated to change in BMI (cluster 2, b= -0.146 [-0.274, 0.566]; cluster 3, b= 0.065 [-0.224, 0.356]). There was also little evidence of gender-based differences in these associations when examined in a three-way interaction. Policymakers may need to begin to consider multiple types of food outlet clusters, while further research is needed to confirm how these relate to changed BMI.

Fast-food outlet availability and obesity: Considering variation by age and methodological diversity in 22,889 Yorkshire Health Study participants.

This study investigated if the relationship between residential fast-food outlet availability and obesity varied due to methodological diversity or by age. Cross-sectional data (n = 22,889) from the Yorkshire Health Study, England were used. Obesity was defined using self-reported height and weight (BMI ≥ 30). Food outlets ("fast-food", "large supermarkets", and "convenience or other food retail outlets") were mapped using Ordnance Survey Points of Interest (PoI) database. Logistic regression was used for all analyses. Methodological diversity included adjustment for other food outlets as covariates and continuous count vs. quartile. The association between residential fast-food outlets and obesity was inconsistent and effects remained substantively the same when considering methodological diversity. This study contributes to evidence by proposing the use of a more comprehensive conceptual model adjusting for wider markers of the food environment. This study offers tentative evidence that the association between fast-food outlets and obesity varies by age.

Investigating the relationship between multimorbidity and dental attendance: a cross-sectional study of UK adults.

Introduction: Regular dental attendance is related to better oral health. However, long-standing health conditions (LSHCs) may be related to dental attendance and this relationship may vary by socioeconomic status. Method: Data were collected from wave two (2013­2015) of the Yorkshire Health Study (n= 7,654). Data included dental attendance, LSHC, age, gender, education-level, smoking, body mass index, and area-level deprivation. Logistic regression (attend or not) was used to analyse associations with LSHC and multimorbidity. Results: Overall, 63.1% (n = 4,826) of individuals attended the dentist. Of these, 37.8% (n =2894) had no LSHC, 26.0% (n = 1987) had one LSHC and 36.4% (n = 2784) had two or more LSHC. The presence of a singular LSHC was not associated with dental attendance(OR = 0.91 [0.81, 1.04]), however, those with two or more LSHCs were more likely to attend the dentist (OR = 0.81 [95% CI 0.72, 0.92]). Interactions between individual-level education, as a marker of socioeconomic status, and LSHC revealed few associations with dental attendance. Conclusion: Multimorbidity was associated with dental attendance such that those with multimorbidity were more likely to attend. These important findings highlight the increasing challenge of multimorbidity for global healthcare systems.

Common acoustic phonon lifetimes in inorganic and hybrid lead halide perovskites.

The acoustic phonons in the organic-inorganic lead halide perovskites have been reported to have anomalously short lifetimes over a large part of the Brillouin zone. The resulting shortened mean free paths of the phonons have been implicated as the origin of the low thermal conductivity. We apply neutron spectroscopy to show that the same acoustic phonon energy linewidth broadening (corresponding to shortened lifetimes) occurs in the fully inorganic CsPbBr3 by comparing the results on the organic-inorganic CH3NH3PbCl3. We investigate the critical dynamics near the three zone boundaries of the cubic P m 3 ¯ m Brillouin zone of CsPbBr3 and find energy and momentum broadened dynamics at momentum points where the Cs-site (A-site) motions contribute to the cross section. Neutron diffraction is used to confirm that both the Cs and Br sites have unusually large thermal displacements with an anisotropy that mirrors the low temperature structural distortions. The presence of an organic molecule is not necessary to disrupt the low-energy acoustic phonons at momentum transfers located away from the zone center in the lead halide perovskites and such damping may be driven by the large displacements or possibly disorder on the A site.

Examining longitudinal associations between the recreational physical activity environment, change in body mass index, and obesity by age in 8864 Yorkshire Health Study participants.

The environment may lead to lower body mass index (BMI) and obesity risk by providing opportunities to be physically active. However, while intuitively appealing, associations are often inconsistent in direction and small scale. This longitudinal study examined if change in BMI and obesity was associated with the availability of physical activity (PA) facilities and parks and explored if these associations differed by age. Longitudinal data (n = 8,864, aged 18-86 years) were provided at baseline (wave I: 2010-2012) and follow up (wave II: 2013-2015) of the Yorkshire Health Study. BMI was calculated using self-reported height (cm) and weight (kg) (obesity = BMI≥30.00). To define availability, home addresses were geocoded based on postcode zone centroids and neighbourhood was defined as a 2 km radial buffer. PA facilities were sourced from Ordnance Survey Points of Interest (PoI) and parks were sourced from OpenStreetMap. Environmental data temporally matched individual-level baseline data collection. PA facilities (b = -0.006 [-0.015, 0.003]) and parks (b = -0.001 [-0.015, 0.013]) at baseline were not associated with change in BMI. Change in obesity was unrelated to parks (OR = 0.994 [0.975, 1.015]) and while PA facilities were related (OR = 0.979 [0.965, 0.993]), effects were small. A combined measure of the recreational PA environment including parks and PA facilities was unrelated to change in BMI and obesity. Despite this, statistically significant interactions were found for both PA facilities, parks, and change in obesity by age. Based on the premise that an individual's mobility varies with age, and although effects were small, this offers tentative evidence which suggests it may be useful for policymakers in Public Health and Planning to consider the impact of environmental interventions across the life course.

A preliminary trial of an online dissonance-based eating disorder intervention.

OBJECTIVE: We conducted a controlled randomized preliminary trial of an expanded online version of the Body Project (n = 46) compared to an assessment-only control condition (n = 36) via a longitudinal design (baseline, postintervention, 2-month follow-up) in a community sample of women (N = 82) with clinical (n = 53) and subclinical (n = 29) eating disorder symptoms. METHOD: The traditional content of the Body Project was modified to include verbal, written, and behavioral exercises designed to dissuade objectification and maladaptive social comparison and adapted to an online format. Body dissatisfaction, self-esteem, self-objectification, thin-ideal internalization, maladaptive social comparison, trait anxiety, positive affect, negative affect, and eating disorder symptomatology were evaluated in the control and the online expanded Body Project condition at baseline, postintervention, and 2-month follow-up. RESULTS: A 2 (condition: online expanded Body Project, control) × 3 (time: baseline, postintervention, 2-month follow-up) mixed factorial multivariate analysis of variance (MANOVA) was conducted to examine statistically significant group differences. As predicted, results indicated a statistically significant condition × time interaction. CONCLUSIONS: Participants in the expanded online Body Project condition showed significant reductions in eating disorder symptoms and several associated psychological risk correlates from baseline to postintervention and follow-up; contrary to predictions, eating disorder symptoms and risk correlates were not significantly lower in the online expanded Body Project condition compared to the waitlist control condition at postintervention or 2-month follow-up.

Anharmonic Magnon Excitations in Noncollinear and Charge-Ordered RbFe

RbFe^{2+}Fe^{3+}F_{6} is an example of a charge ordered antiferromagnet where iron sites, with differing valences, are structurally separated into two interpenetrating sublattices. The low temperature magnetically ordered Fe^{2+} (S=2) and Fe^{3+} (S=5/2) moments form a noncollinear orthogonal structure with the Fe^{3+} site displaying a reduced static ordered moment. Neutron spectroscopy on single crystals finds two distinct spin wave branches with a dominant coupling along the Fe^{3+} chain axis (b axis). High resolution spectroscopic measurements find an intense energy and momentum broadened magnetic band of scattering bracketing a momentum-energy region where two magnon processes are kinematically allowed. These anharmonic excitations are enhanced in this noncollinear magnet owing to the orthogonal spin arrangement.

Protein for Life: Towards a focussed dietary framework for healthy ageing.

'Ageing well' has been highlighted as an important research area by the World Health Organization. In the UK, healthy ageing has been identified as a priority research area by multiple Research Councils and is a key NHS priority. Sarcopaenia, the decline of muscle mass/strength and a key component of healthy ageing, can have a major impact on quality of life and is associated with premature mortality. Increasing protein intake at all stages of the life course may help to reduce the rate of muscle decline and the onset of associated health conditions. However, there is a lack of understanding of the social, demographic and psychological drivers of food choices surrounding protein intake. This report describes the multidisciplinary approach that has been adopted by the Protein for Life project to create a framework for the development of palatable, cost-effective higher-protein foods suitable for an ageing population.

Associations between the combined physical activity environment, socioeconomic status, and obesity: a cross-sectional study.

AIMS: This study investigates associations between the combined physical activity environment and obesity and explores any sub-group effects by individual-level socioeconomic status. METHODS: In a large cross-sectional cohort ( n = 22,889) from the Yorkshire Health Study, body mass index was calculated using self-reported height and weight and obesity was defined as a body mass index ≥ 30. The physical activity environment was split into 'unfavourable physical activity', 'moderately favourable physical activity' and 'favourable physical activity' environments. This was based on the count of parks and physical activity facilities within a 2 km radial buffer centred on home addresses. A favourable physical activity environment was defined as having ≥1 physical activity facility and ≥1 park, unfavourable as having no physical activity facility and park and any other combinations defined as moderately favourable. Logistic regression (odds ratios) identified associations with obesity. RESULTS: Relative to 'unfavourable physical activity environments', individuals within favourable physical activity environments were less likely to be obese (odds ratio = 0.90; 95% confidence interval = 0.82-0.97), and there was no effect for moderately favourable environment. Furthermore, once stratified by education level, this relationship was only present for those of higher education. CONCLUSION: Our findings provide novel UK evidence and is one of the first papers internationally that highlights the importance of considering the interplay of individual-level socioeconomic factors when investigating associations between the physical activity environment and obesity.

Neighbourhood typologies and associations with body mass index and obesity: A cross-sectional study.

Little research has investigated associations between a combined measure of the food and physical activity (PA) environment, BMI (body-mass-index) and obesity. Cross-sectional data (n=22,889, age 18-86years) from the Yorkshire Health Study were used [2010-2013]. BMI was calculated using self-reported height and weight; obesity=BMI≥30. Neighbourhood was defined as a 2km radial buffer. Food outlets and PA facilities were sourced from Ordnance Survey Points of Interest (PoI) and categorised into 'fast-food', 'large supermarkets', 'convenience and other food retail outlets' and 'physical activity facilities'. Parks were sourced from Open Street Map. Latent class analysis was conducted on these five environmental variables and availability was defined by quartiles of exposure. Linear and logistic regressions were then conducted for BMI and obesity respectively for different neighbourhood types. Models adjusted for age, gender, ethnicity, area-level deprivation, and rural/urban classification. A five-class solution demonstrated best fit and was interpretable. Neighbourhood typologies were defined as; 'low availability', 'moderate availability', 'moderate PA, limited food', 'saturated' and 'moderate PA, ample food'. Compared to low availability, one typology demonstrated lower BMI (saturated, b=-0.50, [95% CI=-0.76, -0.23]), while three showed higher BMI (moderate availability, b=0.49 [0.27, 0.72]; moderate PA, limited food, b=0.30 [0.01, 0.59]; moderate PA, ample food, b=0.32 [0.08, 0.57]). Furthermore, compared to the low availability, saturated neighbourhoods showed lower odds of obesity (OR=0.86 [0.75, 0.99]) while moderate availability showed greater odds of obesity (OR=1.18 [1.05, 1.32]). This study supports population-level approaches to tackling obesity however neighbourhoods contained features that were health-promoting and -constraining.

Rumen-protected arginine alters blood flow parameters and luteinizing hormone concentration in cyclic beef cows consuming toxic endophyte-infected tall fescue seed.

The objective of this study was to determine the effect of rumen-protected arginine on median caudal artery blood flow and LH dynamics in cows fed toxic endophyte-infected tall fescue seed. Four ruminally cannulated nonlactating beef cows (539 ± 30 kg) were used in a 2 × 2 factorial arrangement of treatments utilizing a 4 × 4 Latin square design with 4 periods of 31 d each. Each cow was assigned to individual pens and fed orchardgrass hay (10.3% CP and 85% NDF; OM basis) during a 10-d adaptation period, followed by a 21-d collection period in which each cow was assigned 1 of 4 treatments: 1) rumen-protected Arg (180 mg/kg of BW) and 1.0 kg/d of toxic endophyte-infected fescue seed (AE+), 2) rumen-protected Arg (180 mg/kg of BW) and 1.0 kg/d of endophyte-free fescue seed (AE-), 3) 1.0 kg/d of toxic endophyte-infected fescue seed (E+) alone, or 4) 1.0 kg/d of endophyte-free fescue seed (E-) alone. In each period, Doppler ultrasound measurements for blood flow parameters were quantified on d 1, 5, 10, 15, and 20. On d 20 of each period, blood samples were collected every 10 min for 6 h and then once every hour for 12 h for LH response following exogenous GnRH. There was an Arg × fescue seed type interaction ( = 0.05) for median caudal artery blood flow due to an increase in blood flow in cows fed rumen-protected Arg with endophyte-free fescue seed. In addition, mean blood flow velocity in the artery was greater ( = 0.01) with the inclusion of rumen-protected Arg in the diet. Median caudal artery area ( = 0.03) and diameter ( = 0.01) were decreased in cows consuming E+ compared to those consuming E- with no effect ( ≥ 0.38) by Arg inclusion. Circulating nitric oxide (NO) concentrations tended to be influenced ( = 0.09) by the interaction of Arg × fescue seed type with E+ alone decreasing NO concentrations. Circulating NO concentrations were unaffected by rumen-protected Arg ( = 0.48). Mean serum LH concentration exhibited ( = 0.02) an Arg × fescue seed type interaction. Cows consuming E+ had decreased ( < 0.05) LH concentrations compared to all other treatments. However, cows consuming AE+ had ( ≥ 0.67) LH concentrations similar to those of cows consuming AE- and E-. Thus, supplementing rumen-protected Arg to cows consuming toxic endophyte-infected fescue seed has the potential to increase reproductive performance and peripheral blood flow.

Structure and interstitial iodide migration in hybrid perovskite methylammonium lead iodide.

Hybrid perovskites form an emerging family of exceptional light harvesting compounds. However, the mechanism underpinning their photovoltaic effect is still far from understood, which is impeded by a lack of clarity on their structures. Here we show that iodide ions in the methylammonium lead iodide migrate via interstitial sites at temperatures above 280 K. This coincides with temperature dependent static distortions resulting in pseudocubic local symmetry. Based on bond distance analysis, the migrating and distorted iodines are at lengths consistent with the formation of I2 molecules, suggesting a 2I-→I2+2e- redox couple. The actual formula of this compound is thus (CH3NH3)PbI3-2x(I2)x where x∼0.007 at room temperature. A crucial feature of the tetragonal structure is that the methylammonium ions do not sit centrally in the A-site cavity, but disordered around two off-centre orientations that facilitate the interstitial ion migration via a gate opening mechanism.

A Controlled Randomized Preliminary Trial of a Modified Dissonance-Based Eating Disorder Intervention Program.

OBJECTIVE: We conducted a controlled randomized preliminary trial of a modified dissonance-based eating disorder program (n = 24) compared to an assessment-only control condition (n = 23) via a longitudinal design (baseline, postintervention, 2-month follow-up) in a community sample of women (N = 47) with clinical (n = 22) and subclinical (n = 25) eating disorder symptoms. METHOD: The traditional content of the Body Project, a dissonance-based eating disorder prevention program, was modified to include verbal, written, and behavioral exercises designed to dissuade self-objectification and maladaptive social comparison. Women with clinical and subclinical symptoms were included in the target audience to investigate both the treatment and the indicated prevention utility of the modified dissonance program. Body dissatisfaction, self-esteem, self-objectification, thin-ideal internalization, maladaptive social comparison, trait anxiety, and eating disorder symptoms were evaluated in the control and the modified dissonance condition at baseline, postintervention, and 2-month follow-up. RESULTS: We predicted a statistically significant 2 (condition: control, modified dissonance) x 3 (time: baseline, postintervention, 2-month follow-up) interaction in the mixed factorial multivariate analyses of variance results. Results confirmed this hypothesis. Eating disorder risk factors and symptoms decreased significantly among participants in the modified dissonance condition at postintervention and 2-month follow-up compared to baseline; symptom improvement was greater among participants in the modified compared to the control condition. A secondary analysis indicated symptom improvement did not vary as a function of symptom status (clinical, subclinical), suggesting the program is efficacious in both indicated prevention and treatment applications. CONCLUSION: Results provide preliminary support for the modified dissonance program.

Orphan Spins in the S=5/2 Antiferromagnet CaFe_{2}O_{4}.

CaFe_{2}O_{4} is an anisotropic S=5/2 antiferromagnet with two competing A (↑↑↓↓) and B (↑↓↑↓) magnetic order parameters separated by static antiphase boundaries at low temperatures. Neutron diffraction and bulk susceptibility measurements, show that the spins near these boundaries are weakly correlated and a carry an uncompensated ferromagnetic moment that can be tuned with a magnetic field. Spectroscopic measurements find these spins are bound with excitation energies less than the bulk magnetic spin waves and resemble the spectra from isolated spin clusters. Localized bound orphaned spins separate the two competing magnetic order parameters in CaFe_{2}O_{4}.

Solitary Magnons in the S=5/2 Antiferromagnet CaFe_{2}O_{4}.

CaFe_{2}O_{4} is a S=5/2 anisotropic antiferromagnet based upon zig-zag chains having two competing magnetic structures, denoted as the A (↑↑↓↓) and B (↑↓↑↓) phases, which differ by the c-axis stacking of ferromagnetic stripes. We apply neutron scattering to demonstrate that the competing A and B phase order parameters result in magnetic antiphase boundaries along c which freeze on the time scale of ∼1 ns at the onset of magnetic order at 200 K. Using high resolution neutron spectroscopy, we find quantized spin wave levels and measure 9 such excitations localized in regions ∼1-2 c-axis lattice constants in size. We discuss these in the context of solitary magnons predicted to exist in anisotropic systems. The magnetic anisotropy affords both competing A+B orders as well as localization of spin excitations in a classical magnet.

Population-level trends in the distribution of body mass index in England, 1992-2013.

BACKGROUND: Changes over time of mean body weight or prevalence of overweight and obesity have been well documented. Less consideration has been given to describing the distribution to these changes particularly by socioeconomic status and sex. METHODS: We use data from the Health Survey for England for the years 1992-2013 to calculate the median, 5th and 95th centiles, and SD of body mass index (BMI). We tested differences using analysis of variance and quantile regression. Analyses were stratified by sex and level of education. RESULTS: There have been increases in the SD of BMI values over the period. While median BMI has increased, there has been a larger increase of the 95th centile. These trends were consistent by sex and level of education, although significant differences were observed in values. CONCLUSIONS: Our results demonstrate that changes in median BMI over time do not reflect changes in the distribution of BMI. Failing to understand the distribution of body weight in the population will hamper our projections of future patterns, as well as our ability to design effective public health strategies.