Weekly, seasonal and holiday body weight fluctuation patterns among individuals engaged in a European multi-centre behavioural weight loss maintenance intervention

Background: Technological advances in remote monitoring offer new opportunities to quantify body weight patterns in free-living populations. This paper describes body weight fluctuation patterns in response to weekly, holiday (Christmas) and seasonal time periods in a large group of individuals engaged in a weight loss maintenance intervention. Methods: Data was collected as part The NoHoW Project which was a pan-European weight loss maintenance trial. Three eligible groups were defined for weekly, holiday and seasonal analyses, resulting in inclusion of 1,421, 1,062 and 1,242 participants, respectively. Relative weight patterns were modelled on a time series following removal of trends and grouped by gender, country, BMI and age. Results: Within-week fluctuations of 0.35% were observed, characterised by weekend weight gain and weekday reduction which differed between all groups. Over the Christmas period, weight increased by a mean 1.35% and was not fully compensated for in following months, with some differences between countries observed. Seasonal patterns were primarily characterised by the effect of Christmas weight gain and generally not different between groups. Conclusions: This evidence may improve current understanding of regular body weight fluctuation patterns and help target future weight management interventions towards periods, and in groups, where weight gain is anticipated

Estimating physical activity and sedentary behaviour in a free-living environment: A comparative study between Fitbit Charge 2 and Actigraph GT3X

Background: Activity trackers such as the Fitbit Charge 2 enable users and researchers to monitor physical activity in daily life, which could be beneficial for changing behaviour. However, the accuracy of the Fitbit Charge 2 in a free-living environment is largely unknown. Objective: To investigate the agreement between Fitbit Charge 2 and ActiGraph GT3X for the estimation of steps, energy expenditure, time in sedentary behaviour, and light and moderate-to-vigorous physical activity under free-living conditions, and further examine to what extent placing the ActiGraph on the wrist as opposed to the hip would affect the findings. Methods: 41 adults (n = 10 males, n = 31 females) were asked to wear a Fitbit Charge 2 device and two ActiGraph GT3X devices (one on the hip and one on the wrist) for seven consecutive days and fill out a log of wear times. Agreement was assessed through Bland-Altman plots combined with multilevel analysis. Results: The Fitbit measured 1,492 steps/day more than the hip-worn ActiGraph (limits of agreement [LoA] = -2,250; 5,234), while for sedentary time, it measured 25 min/day less (LoA = -137; 87). Both Bland-Altman plots showed fixed bias. For time in light physical activity, the Fitbit measured 59 min/day more (LoA = -52;169). For time in moderate-to-vigorous physical activity, the Fitbit measured 31 min/day less (LoA = -132; 71) and for activity energy expenditure it measured 408 kcal/day more than the hip-worn ActiGraph (LoA = -385; 1,200). For the two latter outputs, the plots indicated proportional bias. Similar or more pronounced discrepancies, mostly in opposite direction, appeared when comparing to the wrist-worn ActiGraph. Conclusion: Moderate to substantial differences between devices were found for most outputs, which could be due to differences in algorithms. Caution should be taken if replacing one device with another and when comparing results

Neuromodulation and the role of electrodiagnostic techniques

Electrodiagnostic techniques have been utilized in surgery since the early 1960s. These techniques have been primarily used in neurosurgery; however, with the introduction of neuromodulation for voiding dysfunction, these techniques have now found their way into the field of female pelvic medicine. This article will review techniques applicable to evaluate pelvic floor function as it relates to neuromodulation. It will also review the literature describing how these techniques are used to help determine appropriate candidates as well as improve surgical outcomes. A PubMed search was conducted using the terms neuromodulation, Interstim, electrodiagnosis, electrodiagnostic techniques, electromyography with limits to the pelvic floor, and voiding dysfunction. Eight articles and three abstracts were found that directly related to the use of electrodiagnostic techniques as they apply to neuromodulation. Electrodiagnostic techniques may play a role in helping predict appropriate candidates for neuromodulation as well as improve surgical outcomes

Multi-Centered Black Hole Flows

We describe the systematical construction of the first order formalism for multi-centered black holes with flat three dimensional base-space, within the so-called $T^{3}$ model of N=2, D=4 ungauged Maxwell-Einstein supergravity. The three possible flow classes (BPS, composite non-BPS and almost-BPS) are analyzed in detail, and various solutions, such as single-centered (static or under-rotating) and all known multi-centered black holes, are recovered in this unified framework. We also consider the possibility of obtaining new solutions. The almost-BPS class is proved to split into two general sub-classes, corresponding to a positive or negative value of the duality-invariant polynomial for the total charge; the well known almost BPS system is shown to be a particular solution of the second sub-class.Comment: 17 pages,no figure

Impact of calcium on salivary α-amylase activity, starch paste apparent viscosity and thickness perception

Thickness perception of starch-thickened products during eating has been linked to starch viscosity and salivary amylase activity. Calcium is an essential cofactor for α-amylase and there is anecdotal evidence that adding extra calcium affects amylase activity in processes like mashing of beer. The aims of this paper were to (1) investigate the role of salivary calcium on α-amylase activity and (2) to measure the effect of calcium concentration on apparent viscosity and thickness perception when interacting with salivary α-amylase in starch-based samples. α-Amylase activity in saliva samples from 28 people was assessed using a typical starch pasting cycle (up to 95 °C). The activity of the enzyme (as measured by the change in starch apparent viscosity) was maintained by the presence of calcium, probably by protecting the enzyme from heat denaturation. Enhancement of α-amylase activity by calcium at 37 °C was also observed although to a smaller extent. Sensory analysis showed a general trend of decreased thickness perception in the presence of calcium, but the result was only significant for one pair of samples, suggesting a limited impact of calcium enhanced enzyme activity on perceived thickness

Data imputation and body weight variability calculation using linear and non-linear methods in data collected from digital smart scales: a simulation and validation study

Background: Body weight variability (BWV) is common in the general population and may act as a risk factor for obesity or diseases. The correct identification of these patterns may have prognostic or predictive value in clinical and research settings. With advancements in technology allowing for the frequent collection of body weight data from electronic smart scales, new opportunities to analyze and identify patterns in body weight data are available. Objective: This study aims to compare multiple methods of data imputation and BWV calculation using linear and nonlinear approaches Methods: In total, 50 participants from an ongoing weight loss maintenance study (the NoHoW study) were selected to develop the procedure. We addressed the following aspects of data analysis: cleaning, imputation, detrending, and calculation of total and local BWV. To test imputation, missing data were simulated at random and using real patterns of missingness. A total of 10 imputation strategies were tested. Next, BWV was calculated using linear and nonlinear approaches, and the effects of missing data and data imputation on these estimates were investigated. Results: Body weight imputation using structural modeling with Kalman smoothing or an exponentially weighted moving average provided the best agreement with observed values (root mean square error range 0.62%-0.64%). Imputation performance decreased with missingness and was similar between random and nonrandom simulations. Errors in BWV estimations from missing simulated data sets were low (2%-7% with 80% missing data or a mean of 67, SD 40.1 available body weights) compared with that of imputation strategies where errors were significantly greater, varying by imputation method. Conclusions: The decision to impute body weight data depends on the purpose of the analysis. Directions for the best performing imputation methods are provided. For the purpose of estimating BWV, data imputation should not be conducted. Linear and nonlinear methods of estimating BWV provide reasonably accurate estimates under high proportions (80%) of missing data

Mother Positivity and Family Adjustment in Households with Children with a Serious Disability

Only limited attention has been given to parent coping resources in the positive adjustment of families of children with a disability. This study is the first to explore maternal positivity as a psychological coping resource related to family adjustment in these families. Consistent with broaden-and-build theory and prior positivity research, positivity was operationalized through a ratio of positive to negative affect scores. We employed longitudinal tracking over a 1 year interval. Children’s diagnostic categories included developmental conditions or impairments, mental health disorders, complex health conditions, physical/motor conditions or impairments, sensory impairments, and provisionally diagnosed conditions or impairments. We used a computer assisted telephone survey to gather psychological, family, and demographic information from 152 mothers in Alberta, Canada. Hierarchical regression analysis indicated mothers’ level of positivity and age, when controlled for family adjustment at Time 1, accounted for 46% of the variance in family adjustment at Time 2. That is, older mothers with higher positivity scores were found to live in households with higher levels of family adjustment after 1 year. These findings provide promising support for broaden-and-build theory, which posits that positive experienced emotions can offset and diminish the negative health and relationship impacts of chronic stress. Study findings support the salience of mothers’ positivity as a psychological coping resource, which is related to enhanced family adjustment in situations of childhood disability

Genetic analysis of a major international collection of cultivated apple varieties reveals previously unknown historic heteroploid and inbred relationships

Domesticated apple (Malus x domestica Borkh.) is a major global crop and the genetic diversity held within the pool of cultivated varieties is important for the development of future cultivars. The aim of this study was to investigate the diversity held within the domesticated form, through the analysis of a major international germplasm collection of cultivated varieties, the UK National Fruit Collection, consisting of over 2,000 selections of named cultivars and seedling varieties. We utilised Diversity Array Technology (DArT) markers to assess the genetic diversity within the collection. Clustering attempts, using the software STRUCTURE revealed that the accessions formed a complex and historically admixed group for which clear clustering was challenging. Comparison of accessions using the Jaccard similarity coefficient allowed us to identify clonal and duplicate material as well as revealing pairs and groups that appeared more closely related than a standard parent-offspring or full-sibling relations. From further investigation, we were able to propose a number of new pedigrees, which revealed that some historically important cultivars were more closely related than previously documented and that some of them were partially inbred. We were also able to elucidate a number of parent-offspring relationships that had resulted in a number of important polyploid cultivars. This included reuniting polyploid cultivars that in some cases dated as far back as the 18th century, with diploid parents that potentially date back as far as the 13th century

The validity of two widely used commercial and research-grade activity monitors, during resting, household and activity behaviours

Wearable devices are increasingly prevalent in research environments for the estimation of energy expenditure (EE) and heart rate (HR). The aim of this study was to validate the HR and EE estimates of the Fitbit charge 2 (FC2), and the EE estimates of the Sensewear armband mini (SWA). We recruited 59 healthy adults to participate in walking, running, cycling, sedentary and household tasks. Estimates of HR from the FC2 were compared to a HR chest strap (Polar) and EE to a stationary metabolic cart (Vyntus CPX). The SWA overestimated overall EE by 0.03 kcal/min−1 and was statistically equivalent to the criterion measure, with a mean absolute percentage error (MAPE) of 29%. In contrast, the FC2 was not equivalent overall (MAPE = 44%). In household tasks, MAPE values of 93% and 83% were observed for the FC2 and SWA, respectively. The FC2 HR estimates were equivalent to the criterion measure overall. The SWA is more accurate than the commercial-grade FC2. Neither device is consistently accurate across the range of activities used in this study. The HR data obtained from the FC2 is more accurate than its EE estimates and future research may focus more on this variable

Increasing condom use in heterosexual men: development of a theory-based interactive digital intervention

Increasing condom use to prevent sexually transmitted infections is a key public health goal. Interventions are more likely to be effective if they are theory- and evidence-based. The Behaviour Change Wheel (BCW) provides a framework for intervention development. To provide an example of how the BCW was used to develop an intervention to increase condom use in heterosexual men (the MenSS website), the steps of the BCW intervention development process were followed, incorporating evidence from the research literature and views of experts and the target population. Capability (e.g. knowledge) and motivation (e.g. beliefs about pleasure) were identified as important targets of the intervention. We devised ways to address each intervention target, including selecting interactive features and behaviour change techniques. The BCW provides a useful framework for integrating sources of evidence to inform intervention content and deciding which influences on behaviour to target