High-intensity intermittent exercise: effect on young people’s cardiometabolic health and cognition

With only a quarter of young people currently meeting physical activity guidelines, two key areas of concern are the effects of exercise on cardio-metabolic health and cognition. Despite the fact that physical activity in young people is typically high intensity and intermittent in nature; much of the literature examines traditional endurance type exercise. This review provides an update on the effects of high intensity intermittent exercise on young people’s cardio-metabolic health and cognition. High intensity intermittent exercise has acute beneficial effects on endothelial function and postprandial lipemia and chronic positive effects on weight management. In addition, there is emerging evidence regarding chronic benefits on blood lipid profile, blood pressure and pro- and anti-inflammatory cytokines. Furthermore, emerging evidence suggests beneficial acute and chronic effects of high intensity intermittent exercise on cognition. However, further research is required in both cardio-metabolic health and cognition, particularly regarding the impact of school-based interventions in adolescents

Topoisomer Differentiation of Molecular Knots by FTICR MS: Lessons from Class II Lasso Peptides

Lasso peptides constitute a class of bioactive peptides sharing a knotted structure where the C-terminal tail of the peptide is threaded through and trapped within an N-terminalmacrolactamring. The structural characterization of lasso structures and differentiation from their unthreaded topoisomers is not trivial and generally requires the use of complementary biochemical and spectroscopic methods. Here we investigated two antimicrobial peptides belonging to the class II lasso peptide family and their corresponding unthreaded topoisomers: microcin J25 (MccJ25), which is known to yield two-peptide product ions specific of the lasso structure under collisioninduced dissociation (CID), and capistruin, for which CID does not permit to unambiguously assign the lasso structure. The two pairs of topoisomers were analyzed by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR MS) upon CID, infrared multiple photon dissociation (IRMPD), and electron capture dissociation (ECD). CID and ECDspectra clearly permitted to differentiate MccJ25 from its non-lasso topoisomer MccJ25-Icm, while for capistruin, only ECD was informative and showed different extent of hydrogen migration (formation of c\bullet/z from c/z\bullet) for the threaded and unthreaded topoisomers. The ECD spectra of the triply-charged MccJ25 and MccJ25-lcm showed a series of radical b-type product ions {\eth}b0In{\TH}. We proposed that these ions are specific of cyclic-branched peptides and result from a dual c/z\bullet and y/b dissociation, in the ring and in the tail, respectively. This work shows the potentiality of ECD for structural characterization of peptide topoisomers, as well as the effect of conformation on hydrogen migration subsequent to electron capture

Interaction effects at crossings of spin-polarized one-dimensional subbands

We report conductance measurements of ballistic one-dimensional (1D) wires defined in GaAs/AlGaAs heterostructures in an in-plane magnetic field, B. When the Zeeman energy is equal to the 1D subband energy spacing, the spin-split subband Nup arrow intersects (N+1)down arrow, where N is the index of the spin-degenerate 1D subband. At the crossing of N=1up arrow and N=2down arrow subbands, there is a spontaneous splitting giving rise to an additional conductance structure evolving from the 1.5(2e(2)/h) plateau. With further increase in B, the structure develops into a plateau and lowers to 2e(2)/h. With increasing temperature and magnetic field the structure shows characteristics of the 0.7 structure. Our results suggest that at low densities a spontaneous spin splitting occurs whenever two 1D subbands of opposite spins cross

Sex differences in adolescents' glycaemic and insulinaemic responses to high and low glycaemic index breakfasts: a randomised control trial

During puberty young people undergo significant hormonal changes which affect metabolism and, subsequently, health. Evidence suggests there is a period of transient pubertal insulin resistance, with this effect greater in girls than boys. However, the response to everyday high and low glycaemic index (GI) meals remains unknown. Following ethical approval, forty adolescents consumed a high GI or low GI breakfast, in a randomised cross-over design. Capillary blood samples were taken during a 2-h postprandial period, examining the glycaemic and insulinaemic responses. Maturity offset and homoeostatic model assessment (HOMA) were also calculated. The glycaemic response to the breakfasts was similar between boys and girls, as shown by similar peak blood glucose concentrations and incremental AUC (IAUC) following both high and low GI breakfasts (all P> 0·05). Girls exhibited a higher peak plasma insulin concentration 30 min post-breakfast following both high GI (P=0·043, g=0·69) and low GI (P =0·010, g =0·84) breakfasts, as well as a greater IAUC following high GI (P=0·041, g =0·66) and low GI (P =0·041, g =0·66) breakfasts. HOMA was positively correlated with the insulinaemic responses (all P<0·0005) and maturity offset (P =0·037). The findings of the present study suggest that pubertal insulin resistance affects the postprandial insulinaemic responses to both high and low GI meals. Specifically, girls exhibit a greater insulinaemic response than boys to both meals, despite similar glycaemic responses. This study is the first to report the glycaemic and insulinaemic responses to everyday meals in boys and girls, supporting the recommendation for young people to base their diet on low GI carbohydrates

Effect of exercise duration on postprandial glycaemic and insulinaemic responses in adolescents

High-intensity intermittent exercise (HIIE) is a potential intervention to manage hyperglycaemia and insulin resistance in adolescents. The aim of this study was to determine the optimum duration of HIIE to reduce postprandial glycaemic and insulinaemic responses in adolescents and the longevity of the response. Thirty-nine participants (12.4 ± 0.4 year) completed a 30- and 60-min exercise trial (Loughborough Intermittent Shuttle Test) and a rested control trial in a randomised crossover design. Capillary blood samples were taken at baseline, immediately and 1-h post-exercise; and 30, 60 and 120 min following a standardised lunch (day one) and a standardised breakfast 24-h post-exercise. Plasma insulin total area under the curve (tAUC) following lunch was lower following 60-min HIIE (21,754 ± 16,861 pmol·L−1 × 120 min, p = 0.032) and tended to be lower following 30-min HIIE (24,273 ± 16,131 pmol·L−1 × 120 min, p = 0.080), when compared with the resting condition (26,931 ± 21,634 pmol·L−1 × 120 min). Blood glucose concentration was lower 1-h post-exercise following 30-min HIIE (3.6 ± 0.6 mmol·L−1) when compared to resting (4.1 ± 0.9 mmol·L−1, p = 0.001). Blood glucose and plasma insulin concentration did not differ across trials on day two. Shorter bouts of HIIE (30-min), as well as a 60-min bout, reduced the postprandial insulinaemic response to lunch, an ecologically valid marker of insulin sensitivity. As the beneficial effects of HIIE were limited to 3 h post-exercise, adolescents are recommended to engage daily HIIE to enhance metabolic health

Exploring how family carers of a person with dementia manage pre-death grief: A mixed methods study

Objectives Many family carers of a person with dementia experience pre-death grief. We aimed to identify strategies that help carers manage pre-death grief. We hypothesised that emotion and problem focussed styles would be associated with lower, and dysfunctional coping with higher grief intensity. Methods Mixed methods observational study using structured and semi-structured interviews with 150 family carers of people with dementia living at home or in a care home. Most participants were female (77%), caring for a parent (48%) or partner/spouse (47%) with mild (25%), moderate (43%) or severe (32%) dementia. They completed the Marwit-Meuser Caregiver Grief Inventory Short Form and the Brief Coping Orientation to Problems Experienced (Brief-COPE) questionnaire. We asked carers to identify strategies used for managing grief. We recorded field notes for 150 interviews and audio-recorded additional interviews with a sub-sample of 16 participants. Results Correlations indicated that emotion-oriented coping was associated with lower grief (R = −0.341), and dysfunctional coping with higher grief (R = 0.435), with a small association with problem-focused strategies (R = −0.109), partly supporting our hypothesis. Our qualitative themes broadly match the three Brief-COPE styles. Unhelpful strategies of denial and avoidance align with dysfunctional coping strategies. Psychological strategies (including acceptance and humour) and seeking support were consistent with emotion-focused strategies, but we did not identify a theme relating to problem-focused strategies. Conclusion Most carers identified multiple strategies for processing grief. Carers could readily identify supports and services that they found helpful for managing pre-death grief, yet current services appear under-resourced to meet growing demand. (ClinicalTrials.gov ID: NCT03332979)

Predictors of postprandial glycaemia, insulinaemia and insulin resistance in adolescents

Postprandial glycaemia and insulinaemia are important risk factors for type 2 diabetes. The prevalence of insulin resistance in adolescents is increasing, but it is unknown how adolescent participant characteristics such as BMI, waist circumference, fitness and maturity offset may explain responses to a standard meal. The aim of the present study was to examine how such participant characteristics affect the postprandial glycaemic and insulinaemic responses to an ecologically valid mixed meal. Data from the control trials of three separate randomised, crossover experiments were pooled, resulting in a total of 108 participants (52 boys, 56 girls; age: 12.5±0.6 y; BMI: 19.05±2.66 kg·m-2). A fasting blood sample was taken for the calculation of fasting insulin resistance, using the HOMA-IR model. Further capillary blood samples were taken before and 30-, 60- and 120-min after a standardised lunch, providing 1.5 g.kg-1 body mass of carbohydrate, for the quantification of blood glucose and plasma insulin total area under the curve (tAUC). Hierarchical multiple linear regression demonstrated significant predictors for plasma insulin tAUC were waist circumference, physical fitness and HOMA-IR (F(3, 98)=36.78, p<.001, Adj. R2=.515). The variance in blood glucose tAUC was not significantly explained by the predictors used (F(7, 94)=1.44, p=.198). Significant predictors for HOMA-IR were BMI and maturity offset (F(2, 102)=14.06, p<.001, Adj. R2=.021). In summary, the key findings of the study are that waist circumference, followed by physical fitness, best explained the insulinemic response to an ecologically valid standardised meal in adolescents. This has important behavioural consequences because these variables can be modified

Is preparation for end of life associated with pre-death grief in caregivers of people with dementia?

OBJECTIVES: Family caregivers of people with dementia can experience loss and grief before death. We hypothesized that modifiable factors indicating preparation for end of life are associated with lower pre-death grief in caregivers. DESIGN: Cross-sectional. SETTING: Caregivers of people with dementia living at home or in a care home. PARTICIPANTS: In total, 150 caregivers, 77% female, mean age 63.0 (SD = 12.1). Participants cared for people with mild (25%), moderate (43%), or severe dementia (32%). MEASUREMENTS: Primary outcome: Marwit-Meuser Caregiver Grief Inventory Short Form (MMCGI-SF). We included five factors reflecting preparation for end of life: (1) knowledge of dementia, (2) social support, (3) feeling supported by healthcare providers, (4) formalized end of life documents, and (5) end-of-life discussions with the person with dementia. We used multiple regression to assess associations between pre-death grief and preparation for end of life while controlling for confounders. We repeated this analysis with MMCGI-SF subscales ("personal sacrifice burden"; "heartfelt sadness"; "worry and felt isolation"). RESULTS: Only one hypothesized factor (reduced social support) was strongly associated with higher grief intensity along with the confounders of female gender, spouse, or adult child relationship type and reduced relationship closeness. In exploratory analyses of MMCGI-SF subscales, one additional hypothesized factor was statistically significant; higher dementia knowledge was associated with lower "heartfelt sadness." CONCLUSION: We found limited support for our hypothesis. Future research may benefit from exploring strategies for enhancing caregivers' social support and networks as well as the effectiveness of educational interventions about the progression of dementia (ClinicalTrials.gov ID: NCT03332979)

Effect of football activity and physical fitness on information processing, inhibitory control and working memory in adolescents

Background: Whilst an acute bout of exercise has been shown to enhance subsequent cognition, including in adolescents, the effects of team games (of which Football is the most popular) has received little attention. Therefore, this study examined: the effect of an acute bout of outdoor Football activity on information processing, inhibitory control, working memory and circulating brain-derived neurotrophic factor (BDNF) in adolescents; the effect of physical fitness on cognition and; the moderating effect of physical fitness on the acute exercise responses. Methods: Following familiarisation, 36 adolescents (16 girls) took part in two trials (60-min Football and 60-min seated rest) separated by 7-d in a counterbalanced, crossover design. Information processing and inhibitory control (Stroop Test), and working memory (Sternberg Paradigm) were assessed 30-min before exercise/rest and immediately, 45- and 90-min post-exercise/rest. Capillary blood samples were obtained before exercise/rest and up to 120-min post-exercise/rest. The median split of distance covered on the MSFT was used to divide the group into high- and low-fit groups. Results: Performance on the cognitive function tasks was similar between Football and seated rest (trial*time interactions; all p > .05). However, the high-fit group had overall quicker response times on both levels of the Stroop Task and all three levels of the Sternberg Paradigm (main effect of fitness; all p  .05). Conclusion: The present study shows that higher levels of physical fitness are beneficial for cognitive function and provides novel evidence that an ecologically valid, and popular, form of exercise is beneficial for working memory following exercise, in high-fit participants only

A synthetic electric force acting on neutral atoms

Electromagnetism is a simple example of a gauge theory where the underlying potentials -- the vector and scalar potentials -- are defined only up to a gauge choice. The vector potential generates magnetic fields through its spatial variation and electric fields through its time-dependence. We experimentally produce a synthetic gauge field that emerges only at low energy in a rubidium Bose-Einstein condensate: the neutral atoms behave as charged particles do in the presence of a homogeneous effective vector potential. We have generated a synthetic electric field through the time dependence of an effective vector potential, a physical consequence even though the vector potential is spatially uniform