Impact of accelerometer data processing decisions on the sample size, wear time and physical activity level of a large cohort study

Background: Accelerometers objectively assess physical activity (PA) and are currently used in several large-scale epidemiological studies, but there is no consensus for processing the data. This study compared the impact of wear-time assessment methods and using either vertical (V)-axis or vector magnitude (VM) cut-points on accelerometer output. Methods: Participants (7,650 women, mean age 71.4 y) were mailed an accelerometer (ActiGraph GT3X+), instructed to wear it for 7 days, record dates and times the monitor was worn on a log, and return the monitor and log via mail. Data were processed using three wear-time methods (logs, Troiano or Choi algorithms) and V-axis or VM cut-points. Results: Using algorithms alone resulted in "mail-days" incorrectly identified as "wear-days" (27-79% of subjects had >7-days of valid data). Using only dates from the log and the Choi algorithm yielded: 1) larger samples with valid data than using log dates and times, 2) similar wear-times as using log dates and times, 3) more wear-time (V, 48.1 min more; VM, 29.5 min more) than only log dates and Troiano algorithm. Wear-time algorithm impacted sedentary time (~30-60 min lower for Troiano vs. Choi) but not moderate-to-vigorous (MV) PA time. Using V-axis cut-points yielded ~60 min more sedentary time and ~10 min less MVPA time than using VM cut-points. Conclusions: Combining log-dates and the Choi algorithm was optimal, minimizing missing data and researcher burden. Estimates of time in physical activity and sedentary behavior are not directly comparable between V-axis and VM cut-points. These findings will inform consensus development for accelerometer data processing in ongoing epidemiologic studies. Electronic supplementary material The online version of this article (doi:10.1186/1471-2458-14-1210) contains supplementary material, which is available to authorized users

Ripley Valley – an application of GIS based runoff modelling to strategic stormwater harvesting assessment

Stormwater management broadly has been well accepted as necessary for both flood avoidance and importantly also the prevention of aquatic ecosystem degradation within and around cities. Harvesting stormwater to provide diversification of water supplies offers a way of avoiding flooding and ecosystem degradation as well as acting to improve the climate resilience of cities. With Australia's population overwhelmingly urban in character, and the climate well known to oscillate between droughts and flooding rains, the opportunities represented by stormwater harvesting are significant, for both greenfield and brownfield developments

Sacrificial Adhesive Bonding: A Powerful Method For Fabrication Of Glass Microchips.

A new protocol for fabrication of glass microchips is addressed in this research paper. Initially, the method involves the use of an uncured SU-8 intermediate to seal two glass slides irreversibly as in conventional adhesive bonding-based approaches. Subsequently, an additional step removes the adhesive layer from the channels. This step relies on a selective development to remove the SU-8 only inside the microchannel, generating glass-like surface properties as demonstrated by specific tests. Named sacrificial adhesive layer (SAB), the protocol meets the requirements of an ideal microfabrication technique such as throughput, relatively low cost, feasibility for ultra large-scale integration (ULSI), and high adhesion strength, supporting pressures on the order of 5 MPa. Furthermore, SAB eliminates the use of high temperature, pressure, or potential, enabling the deposition of thin films for electrical or electrochemical experiments. Finally, the SAB protocol is an improvement on SU-8-based bondings described in the literature. Aspects such as substrate/resist adherence, formation of bubbles, and thermal stress were effectively solved by using simple and inexpensive alternatives.51327

Classification and processing of 24-hour wrist accelerometer data

Background: An important step in accelerometer data analysis is the classification of continuous, 24-hour data into sleep, wake, and non-wear time. We compared classification times and physical activity metrics across different data processing and classification methods. Methods: Participants (n = 576) from the Finnish Retirement and Aging Study (FIREA) wore an accelerometer on their non-dominant wrist for seven days and nights and filled in daily logs with sleep and waking times. Accelerometer data were first classified as sleep or wake time by log, and Tudor-Locke, Tracy, and ActiGraph algorithms. Then, wake periods were classified as wear or non-wear by log, Choi algorithm, and wear sensor. We compared time classification (sleep, wake, and wake wear time) as well as physical activity measures (total activity volume and sedentary time) across these classification methods. Results: M (SD) nightly sleep time was 467 (49) minutes by log and 419 (88), 522 (86), and 453 (74) minutes by Tudor-Locke, Tracy, and ActiGraph algorithms, respectively. Wake wear time did not differ substantially when comparing Choi algorithm and the log. The wear sensor did not work properly in about 29% of the participants. Daily sedentary time varied by 8−81 minutes after excluding sleep by different methods and by 1−18 minutes after excluding non-wear time by different methods. Total activity volume did not substantially differ across the methods. Conclusion: The differences in wear and sedentary time were larger than differences in total activity volume. Methods for defining sleep periods had larger impact on outcomes than methods for defining wear time.</p

Systematic literature review of determinants of sedentary behaviour in older adults:a DEDIPAC study

BACKGROUND: Older adults are the most sedentary segment of society and high sedentary time is associated with poor health and wellbeing outcomes in this population. Identifying determinants of sedentary behaviour is a necessary step to develop interventions to reduce sedentary time. METHODS: A systematic literature review was conducted to identify factors associated with sedentary behaviour in older adults. Pubmed, Embase, CINAHL, PsycINFO and Web of Science were searched for articles published between 2000 and May 2014. The search strategy was based on four key elements: (a) sedentary behaviour and its synonyms; (b) determinants and its synonyms (e.g. correlates, factors); (c) types of sedentary behaviour (e.g. TV viewing, sitting, gaming) and (d) types of determinants (e.g. environmental, behavioural). Articles were included in the review if specific information about sedentary behaviour in older adults was reported. Studies on samples identified by disease were excluded. Study quality was rated by means of QUALSYST. The full review protocol is available from PROSPERO (PROSPERO 2014: CRD42014009823). The analysis was guided by the socio-ecological model framework. RESULTS: Twenty-two original studies were identified out of 4472 returned by the systematic search. These included 19 cross-sectional, 2 longitudinal and 1 qualitative studies, all published after 2011. Half of the studies were European. The study quality was generally high with a median of 82 % (IQR 69-96 %) using Qualsyst tool. Personal factors were the most frequently investigated with consistent positive association for age, negative for retirement, obesity and health status. Only four studies considered environmental determinants suggesting possible association with mode of transport, type of housing, cultural opportunities and neighbourhood safety and availability of places to rest. Only two studies investigated mediating factors. Very limited information was available on contexts and sub-domains of sedentary behaviours. CONCLUSION: Few studies have investigated determinants of sedentary behaviour in older adults and these have to date mostly focussed on personal factors, and qualitative studies were mostly lacking. More longitudinal studies are needed as well as inclusion of a broader range of personal and contextual potential determinants towards a systems-based approach, and future studies should be more informed by qualitative work

An unusual case of hypothermia associated with therapeutic doses of olanzapine: a case report

<p>Abstract</p> <p>Introduction</p> <p>We report a case of a 42-year-old man who had symptomatic hypothermia as a result of taking olanzapine for paranoid schizophrenia. According to published data, only a few cases of hypothermia associated with olanzapine have been reported since its introduction into clinical use.</p> <p>Case presentation</p> <p>A 42-year-old Sri Lankan man with schizophrenia who was being treated with a therapeutic dose of olanzapine presented with reduced level of consciousness. He had a core temperature of 32°C and was bradycardic. At the time of admission, the electrocardiogram showed sinus bradycardia with J waves. He did not have any risk factors for developing hypothermia except the use of olanzapine. There was improvement in his clinical condition with reversal of electrocardiogram changes following gradual rewarming and the omission of olanzapine.</p> <p>Conclusion</p> <p>Hypothermia induced by antipsychotic medications is not uncommon, but olanzapine-induced hypothermia is rare and occurrence has been reported during initiation or increasing the dose. But here the patient developed hypothermia without dose adjustment.</p

TRITIUM, HYDROGEN AND OXYGEN ISOTOPE COMPOSITIONS IN MONTHLY PRECIPITATION SAMPLES COLLECTED AT TOKI, JAPAN

Monthly precipitation samples have been collected at Toki, Japan, from November 2013 to March 2017. In this report, selected data were analysed to identify the regional hydrogen and oxygen isotope compositions. Tritium (3H) concentration in the precipitation ranged from 0.10 to 0.61 Bq L−1 and higher 3H concentrations were observed in spring rather than in other seasons. This range was similar to values reported in Chiba City, Japan. 3H concentration and the ratio d-excess, and δD values were roughly clustered according to each separate season. These regional hydrogen and oxygen isotope compositions will be used for environmental assessments of effects of the deuterium plasma experiments of the large fusion test device