'We eat together; today she buys, tomorrow I will buy the food': adolescent best friends' food choices and dietary practices in Soweto, South Africa

Objective To explore if and how female adolescents engage in shared eating and joint food choices with best friends within the context of living in urban Soweto, South Africa. Design A qualitative, exploratory, multiple case study was conducted using semi-structured duo interviews of best friend pairs to ascertain their eating patterns, friendship and social interactions around dietary habits. Setting Participants were recruited from three high schools in the urban township of Soweto, South Africa. Subjects Fifty-eight female adolescents (twenty-nine friend pairs) still in high school (mean age of 18 years) were enrolled. Results Although overweight rates were high, no association between friends was found; neither did friends share dieting behaviours. Both at school and during visits to the shopping mall, foods were commonly shared and money pooled together by friends to make joint purchases. Some friends carefully planned expenditures together. Foods often bought at school were mostly unhealthy. Availability, price and quality were reported to affect choice of foods purchased at school. Preference shaped joint choices within the shopping mall environment. Conclusions Food sharing practices should be investigated in other settings so as to identify specific behaviours and contexts for targeted and tailored obesity prevention interventions. School-based interventions focusing on price and portion size should be considered. In the Sowetan context, larger portions of healthy food may improve dietary intake of fruit and vegetables where friends are likely to share portions. © 2012 The Authors

Impact of biological sex and gender-related factors on public engagement in protective health behaviours during the COVID-19 pandemic: cross-sectional analyses from a global survey

Objective Given the role of sociocultural gender in shaping human behaviours, the main objective of this study was to examine whether sex and gender-related factors were associated with the public’s adherence to COVID-19-recommended protective health behaviours. Design This was a retrospective analysis of the survey that captured data on people’s awareness, attitudes and behaviours as they relate to the COVID-19 policies. Setting Data from the International COVID-19 Awareness and Responses Evaluation survey collected between March 2020 and February 2021 from 175 countries. Participants Convenience sample around the world. Main outcome measures We examined the role of sex and gender-related factors in relation to non-adherence of protective health behaviours including: (1) hand washing; (2) mask wearing; and (3) physical distancing. Multivariable logistic regression was conducted to determine the factors associated with non-adherence to behaviours. Results Among 48 668 respondents (mean age: 43 years; 71% female), 98.3% adopted hand washing, 68.5% mask wearing and 76.9% physical distancing. Compared with males, females were more likely to adopt hand washing (OR=1.97, 95% CI: 1.71 to 2.28) and maintain physical distancing (OR=1.28, 95% CI: 1.22 to 1.34). However, in multivariable sex-stratified models, females in countries with higher Gender Inequality Indexes (GII) were less likely to report hand washing (adjusted OR (aOR)=0.47, 95% CI: 0.21 to 1.05). Females who reported being employed (aOR=0.22, 95% CI: 0.10 to 0.48) and in countries with low/medium GIIs (aOR=0.18, 95% CI 0.06 to 0.51) were less likely to report mask wearing. Females who reported being employed were less likely to report physical distancing (aOR=0.39, 95% CI: 0.32 to 0.49). Conclusion While females showed greater adherence to COVID-19 protective health behaviours, gender-related factors, including employment status and high country-wide gender inequality, were independently associated with non-adherence. These findings may inform public health and vaccination policies in current as well as future pandemics

Supermassive Binaries and Extragalactic Jets

Some quasars show Doppler shifted broad emission line peaks. I give new statistics of the occurrence of these peaks and show that, while the most spectacular cases are in quasars with strong radio jets inclined to the line of sight, they are also almost as common in radio-quiet quasars. Theories of the origin of the peaks are reviewed and it is argued that the displaced peaks are most likely produced by the supermassive binary model. The separations of the peaks in the 3C 390.3-type objects are consistent with orientation-dependent "unified models" of quasar activity. If the supermassive binary model is correct, all members of "the jet set" (astrophysical objects showing jets) could be binaries.Comment: 31 pages, PostScript, missing figure is in ApJ 464, L105 (see http://www.aas.org/ApJ/v464n2/5736/5736.html

Changes in postictal cerebral perfusion are related to the duration of electroconvulsive therapy-induced seizures

Objective: Postictal symptoms may result from cerebral hypoperfusion, which is possibly a consequence of seizure-induced vasoconstriction. Longer seizures have previously been shown to cause more severe postictal hypoperfusion in rats and epilepsy patients. We studied cerebral perfusion after generalized seizures elicited by electroconvulsive therapy (ECT) and its relation to seizure duration. Methods: Patients with a major depressive episode who underwent ECT were included. During treatment, 21-channel continuous electroencephalogram (EEG) was recorded. Arterial spin labeling magnetic resonance imaging scans were acquired before the ECT course (baseline) and approximately 1 h after an ECT-induced seizure (postictal) to quantify global and regional gray matter cerebral blood flow (CBF). Seizure duration was assessed from the period of epileptiform discharges on the EEG. Healthy controls were scanned twice to assess test–retest variability. We performed hypothesis-driven Bayesian analyses to study the relation between global and regional perfusion changes and seizure duration. Results: Twenty-four patients and 27 healthy controls were included. Changes in postictal global and regional CBF were correlated with seizure duration. In patients with longer seizure durations, global decrease in CBF reached values up to 28 mL/100 g/min. Regional reductions in CBF were most prominent in the inferior frontal gyrus, cingulate gyrus, and insula (up to 35 mL/100 g/min). In patients with shorter seizures, global and regional perfusion increased (up to 20 mL/100 g/min). These perfusion changes were larger than changes observed in healthy controls, with a maximum median global CBF increase of 12 mL/100 g/min and a maximum median global CBF decrease of 20 mL/100 g/min. Significance: Seizure duration is a key factor determining postictal perfusion changes. In future studies, seizure duration needs to be considered as a confounding factor due to its opposite effect on postictal perfusion.</p

Quantum walks: a comprehensive review

Quantum walks, the quantum mechanical counterpart of classical random walks, is an advanced tool for building quantum algorithms that has been recently shown to constitute a universal model of quantum computation. Quantum walks is now a solid field of research of quantum computation full of exciting open problems for physicists, computer scientists, mathematicians and engineers. In this paper we review theoretical advances on the foundations of both discrete- and continuous-time quantum walks, together with the role that randomness plays in quantum walks, the connections between the mathematical models of coined discrete quantum walks and continuous quantum walks, the quantumness of quantum walks, a summary of papers published on discrete quantum walks and entanglement as well as a succinct review of experimental proposals and realizations of discrete-time quantum walks. Furthermore, we have reviewed several algorithms based on both discrete- and continuous-time quantum walks as well as a most important result: the computational universality of both continuous- and discrete- time quantum walks.Comment: Paper accepted for publication in Quantum Information Processing Journa

Dietary behaviours in the context of nutrition transition : a systematic review and meta-analyses in two African countries

Objective: To synthesise evidence of urban dietary behaviours (macronutrients, types of foods, dietary diversity and dietary practices) in two African countries in relation to postulated changes in the context of nutrition transition. Design: Systematic review and meta-analyses, including six online databases and grey literature, 1971–2018 (Protocol CRD42017067718). Setting: Urban Ghana and Kenya. Participants: Population-based studies of healthy adolescents and adults. Results: The forty-seven included studies encompassed 20 726 individuals plus 6526 households. Macronutrients were within WHO-recommended ranges: mean energy intake was 1867 kcal/d (95 % CI 1764, 1969) and the proportions of macronutrients were carbohydrate 61·2 % (58·4, 64·0), fat 25·3 % (22·8, 28·0) and protein 13·7 % (12·3, 15·1). The proportion of population consuming fruit and vegetables was 51·6 %; unhealthy foods, 29·4 %; and sugar-sweetened beverages (SSBs), 39·9 %. Two-thirds (68·8 %) consumed animal-source proteins. Dietary diversity scores were within the mid-range. Meal patterns were structured (typically three meals per day), with evidence lacking on snacking or eating out. Conclusions: Population-level diets fell within WHO macronutrient recommendations, were relatively diverse with structured meal patterns, but some indications of nutrition transition were apparent. The proportion of population consuming fruit and vegetables was low compared to healthy-eating recommendations, and consumption of SSBs was widespread. A paucity of evidence from 1971 to 2010 precluded a longitudinal analysis of nutrition transition. Evidence from these two countries indicates which aspects of dietary behaviours may be contributing to increasing overweight/obesity, namely a low proportion of population consuming fruit and vegetables and widespread consumption of SSBs. These are potential targets for promoting healthier diets

Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

Measuring decisional certainty among women seeking abortion

ObjectiveEvaluating decisional certainty is an important component of medical care, including preabortion care. However, minimal research has examined how to measure certainty with reliability and validity among women seeking abortion. We examine whether the Decisional Conflict Scale (DCS), a measure widely used in other health specialties and considered the gold standard for measuring this construct, and the Taft-Baker Scale (TBS), a measure developed by abortion counselors, are valid and reliable for use with women seeking abortion and predict the decision to continue the pregnancy.MethodsEligible women at four family planning facilities in Utah completed baseline demographic surveys and scales before their abortion information visit and follow-up interviews 3 weeks later. For each scale, we calculated mean scores and explored factors associated with high uncertainty. We evaluated internal reliability using Cronbach's alpha and assessed predictive validity by examining whether higher scale scores, indicative of decisional uncertainty or conflict, were associated with still being pregnant at follow-up.ResultsFive hundred women completed baseline surveys; two-thirds (63%) completed follow-up, at which time 11% were still pregnant. Mean scores on the DCS (15.5/100) and TBS (12.4/100) indicated low uncertainty, with acceptable reliability (α=.93 and .72, respectively). Higher scores on each scale were significantly and positively associated with still being pregnant at follow-up in both unadjusted and adjusted analyses.ConclusionThe DCS and TBS demonstrate acceptable reliability and validity among women seeking abortion care. Comparing scores on the DCS in this population to other studies of decision making suggests that the level of uncertainty in abortion decision making is comparable to or lower than other health decisions.ImplicationsThe high levels of decisional certainty found in this study challenge the narrative that abortion decision making is exceptional compared to other healthcare decisions and requires additional protection such as laws mandating waiting periods, counseling and ultrasound viewing