Counts Per Minute Research Articles

ASSESSMENT OF BACKGROUND IONIZING RADIATION LEVEL OF SCRAP METAL DUMPSITES IN DUTSE TOWN, JIGAWA STATE, NIGERIA

The level of awareness of the radiation hazards from indiscriminate dumping of scrap metals isvery low in developing countries. In this study, the background ionizing radiation level of scrapmetal dumpsites in Dutse Town, Jigawa State, Nigeria was assessed. A hand-held RadiationAlert Inspector (RAI) was used and a total of Ten (10) scrap metal dumpsites were randomlyselected. Four readings were taken in Counts Per Minute (CPM) and micro Sievert perhour(µSv/hr) at four (4) different selected points on each of the dumpsites. The value ofexposure dose rate (in µSv/hr) was used to estimate the Absorbed Dose D (in nGy/hr), AnnualEffective Dose (in mSvy-1) and Excess Lifetime Cancer Risk respectively. The results show thatthe mean exposure dose rate range from 0.01225 to 0.02125 µSv/hr. All the values of exposuredose rate were found to be below the standard value of 0.133 μSv/h. The mean value of theAbsorbed Dose D varies from 12.25 to 21.25 nGy/hr respectively. The calculated mean AnnualEffective Dose was found to be in the range of 0.015023 to 0.026061 mSvy-1. These values arebelow 1.0 mSvy-1 dose limit recommended by the International Commission on RadiologicalProtection (ICRP). The mean Excess Lifetime Cancer Risk range from 0.052582 to 0.091214 andare lower than the world limit of 0.29 × 10-3. The study indicates that the people working andliving within the study area are safe and are not exposed to high doses of radiation as result ofactivities in the dumpsite. However, continuous monitoring of background radiation in thedumpsites is recommended.Keyword: Radiation, Excess lifetime cancer risk, Dumpsites, Absorbed Dose, Annual EffectiveDose

Particle Filter Based Range Search Approach for Localization of Radioactive Materials

Wireless Sensor Networks (WSNs) have recently become crucial in monitoring operations. The development of a Data Fusion Algorithm for radioactive source localization utilizing WSN based on the Particle Filter (PF) technique is presented. The localization of an unknown-intensity point radioactive source using sensor nodes measured intensities in Count per Minute (CPM) is considered. The surveillance area is covered by several sensors (radiation detectors) n. Instead of using four sensors, as described in previous research, two consecutive sensors are used in sequence (S1, S2), (S2, S3)……, (Sn-1, Sn) till reaching the last sensor available Sn. Apollonius circle calculated range guides a particle filter for estimating the source location using actual measurements. Compared with other approaches such as the Iterative Pruning Clustering algorithm, more accurate estimates in terms of the error between the estimated source position and ground truth are obtained. The comparison is conducted using the same real measurements data. The Particle Filter based algorithm is implemented in a Xilinx FPGA chip. The architecture is a two sequential steps implementation, where particle generation, weight calculation, and normalization are carried out in parallel during the first step, followed by a sequential or parallelized resampling in the second step. This architecture targets a balance between hardware resources and speed of operation. The future work plan includes security-related studies and complete WSN implementation using μC/FPGA devices.

A Non-Invasive Approach in the Assessment of Stress Phenomena and Impairment Values in Pea Seeds Caused by Pea Weevil.

Pea (Pisum sativum L.) is an important leguminous plant worldwide, in which pests trigger significant damage every year. One of the most important pest is pea weevil (Bruchus pisorum, L) which causes covert damage in crops. In the present study, our aim was to obtain precise information pertaining to the extent and the nature of damage in pea caused by B. pisorum by means of non-invasive imaging methods. The infested pea samples were analysed by an infrared thermometer and a bioluminescence plant imaging system as well as a computer tomograph under laboratory conditions. The calculated weight of organic matter destroyed by the developing larvae was 36.46%. The changing of RGB (red, blue, green) codes obtained through thermal imaging and the CPS (counts per second) values originating from bioluminescence imaging in infested samples were statistically verifiable. According to our CT assay, the damage caused by B. pisorum changed the tissue density, volume and shape of the pea seeds by the end of the development of the pest. The results of thermal and bioluminescence imaging contribute to a better understanding of the internal chemical processes and the CT analysis helps to understand the alteration trends of the inner structure of seeds caused by this pest.

Exercise intensity and enjoyment response of selected traditional games in children

Background: Given that few children engage in the minimal requirement of moderate-to vigorous physical activity (MVPA), traditional games have been promoted as one of the strategies to improve MVPA levels to facilitate health enhancement, particularly in school settings. Nevertheless, little is known about the exercise intensity and enjoyment levels of traditional games in children. Methods: Participants (n = 600; 300 boys; age 10.1 ± 0.8) performed five selected traditional games (i.e. Bola Beracun, Baling Tin, Polis Sentri, Belalang Belatuk and Galah Panjang) for 20 min. Activity counts per minute (CPM), metabolic equivalent (METs) and activity time spent were recorded via accelerometer during all traditional games. Enjoyment responses were recorded before and after the traditional games. Results: No significant differences were observed across all traditional games for each variable (CPM, METs and enjoyment responses; p > 0.05). However, all selected traditional games played for 20 min elicited sufficient levels of MVPA based on CPM and METs thresholds (>500 CPM and >3 METs). The post-enjoyment score was significantly higher in all traditional games compared to pre-enjoyment (p < 0.01; effect size >0.47). Conclusions: Incorporating traditional games in a school setting for 20-min per session may facilitate sufficient levels of MVPA and augment enjoyment in children to promote multiple health benefits and future exercise engagement, respectively.

Transport of the Chemokines CCL5 and CCL2 Across the Mouse Blood‐Brain Barrier under Physiological and Inflammatory Conditions

Chemokines are important regulators of neuroinflammation and interact with brain endothelial cells that comprise the blood-brain barrier (BBB) to modulate their function and promote their interactions with leukocytes. Chemokines can also cross the intact BBB, which may contribute to their functions in the brain, but interactions of chemokines with the BBB in vivo are understudied. Here, we show that the chemokines C-C motif ligand 2 (CCL2) and C-C motif ligand 5 (CCL5), which have been well-studied in context of their neuroinflammatory functions, are amenable to labeling with 125I. This affords highly sensitive and quantitative detection of CCL2 and CCL5 in vivo, and allows for rapid assessment of the distribution of circulating chemokines. Multiple-time regression analysis was used to characterize chemokine transport across the mouse BBB. In untreated mice, we evaluated the brain uptake of CCL2 and CCL5 and characterized saturability of uptake and endothelial binding vs. transport. We then determined whether CCL2 and CCL5 interactions with the BBB are altered in mice treated with three doses of 3mg/kg lipopolysaccharide. Our results indicate that in addition to endothelial binding at the glycocalyx, there is uptake of both CCL5 and CCL2 into the mouse brain parenchyma. We found no significant difference in the rate of chemokine uptake in mice treated with LPS versus untreated mice. However, the 125I counts per minute (CPM) was significantly higher in the brains of LPS mice versus untreated mice brains, indicating that more radio-labelled chemokine had entered the brain after LPS-induced inflammation. In conclusion, we have found that chemokines interact with the intact BBB, and alterations in theses interactions with inflammation can be detected in vivo. As a future direction, this method can be utilized to evaluate pharmacological approaches to inhibiting BBB/chemokine interactions, which may protect against harmful neuroinflammation during neurological disease.

Accelerometer Calibration: The Importance of Considering Functionality.

To compare the accuracy and precision of a hip-worn accelerometer to predict energy cost during structured activities across motor performance and disease conditions. 118 adults self-identifying as healthy (n = 44) and those with arthritis (n = 23), multiple sclerosis (n = 18), Parkinson's disease (n = 17), and stroke (n =18) underwent measures of motor performance and were categorized into groups: Group 1, usual; Group 2, moderate impairment; and Group 3, severe impairment. The participants completed structured activities while wearing an accelerometer and a portable metabolic measurement system. Accelerometer-predicted energy cost (metabolic equivalent of tasks [METs]) were compared with measured METs and evaluated across functional impairment and disease conditions. Statistical significance was assessed using linear mixed effect models and Bayesian information criteria to assess model fit. All activities' accelerometer counts per minute (CPM) were 29.5-72.6% less for those with disease compared with those who were healthy. The predicted MET bias was similar across disease, -0.49 (-0.71, -0.27) for arthritis, -0.38 (-0.53, -0.22) for healthy, -0.44 (-0.68, -0.20) for MS, -0.34 (-0.58, -0.09) for Parkinson's, and -0.30 (-0.54, -0.06) for stroke. For functional impairment, there was a graded reduction in CPM for all activities: Group 1, 1,215 CPM (1,129, 1,301); Group 2, 789 CPM (695, 884); and Group 3, 343 CPM (220, 466). The predicted MET bias revealed similar results across the Group 1, -0.37 METs (-0.52, -0.23); Group 2, -0.44 METs (-0.60, -0.28); and Group 3, -0.33 METs (-0.55, -0.13). The Bayesian information criteria showed a better model fit for functional impairment compared with disease condition. Using functionality to improve accelerometer calibration could decrease variability and warrants further exploration to improve accelerometer prediction of physical activity.

Accelerometer-measured Sedentary Patterns Are Related To Poorer Inhibitory Control In Obese-middle-aged Adults

Self-reported sedentary behaviors have been negatively related to executive functions (EFs) in older adults. However, the relationship of objectively measured sedentary time (ST) to EFs in adults with overweight and obesity is poorly understood. PURPOSE: To assess the relationship between accelerometer-measured ST and inhibitory control in middle-aged adults with overweight and obesity. METHODS: Pre-intervention data from 87 subjects (60 (67%) females, Mage = 35.0 ± 5.9 yrs, BMI= 32.2 ± 5.4 kg/m2) participating in the Persea Americana for Total Health randomized controlled trial were analyzed. ST and physical activity were measured over 7 days with a hip-worn wGT3X-BT accelerometer. Valid wear time was defined as ≥ 4 days, ≥ 10 hrs/d. Daily ST (min/d), frequency, and time spent in sedentary bouts lasting ≥ 5, 10, 20 and 30 consecutive min were estimated using a < 100 counts per minute (CPM) cut point. Moderate-to-vigorous physical activity (MVPA) was defined using an NHANES cut point. Inhibitory control was expressed as accuracy (AC), reaction time (RT), and inverse efficiency (IE = AC/RT) on incongruent trials of a modified Eriksen flanker task; performance on congruent trials indexed controlled processes. Multiple hierarchical regression models controlling for age, sex, intelligence, % fat mass, MVPA and ST (for sedentary bouts) were used to assess relationships between ST, sedentary bouts, inhibitory control, and controlled processes. RESULTS: Frequency (bs ≤ -0.22, ts ≥ 2.11, Ps ≤ 0.04, Fs(6,86) ≥ 3.25, Ps ≤ 0.007) and time (bs ≤ -0.22, ts ≥ 2.01, Ps ≤ 0.047, Fs(6,86) ≥ 3.17, Ps ≤ 0.008) spent in sedentary bouts lasting ≥ 20 and 30 min were associated with lower AC during incongruent trials. While ST and time spent in sedentary bouts ≥ 20 min were related to faster RTs during congruent trials (bs ≤ -0.23, ts ≥ 2.08, Ps ≤ 0.04, Fs(6,86) ≥ 3.04, Ps ≤ 0.01), greater ST was related to lower IE on congruent and incongruent trials (bs ≤ -0.43, ts ≥ 2.33, Ps ≤ 0.023, Fs(7,86) ≥ 2.76, Ps ≤ 0.01). CONCLUSION: In adults with overweight and obesity, more prolonged ST was related to poorer inhibitory control and less efficient controlled processes as indicated by more impulsive responding. Our results reveal a novel relationship between sedentary patterns and an aspect of EFs that has been implicated in the maintenance of obesogenic behaviors.

Active play in ASP \u2013a matched-pair cluster-randomized trial investigating the effectiveness of an intervention in after-school programs for supporting children\u2019s physical activity

BackgroundInterventions directed at after school programs (ASPs) have the potential to support physical activity (PA) in young children. Research has indicated that interventions that emphasize competence building among the ASP staff can lead to increased PA among the children. The present study evaluates the effectiveness of the Active Play in ASP intervention—a program for ASP staff aimed at supporting physical activity among first graders in ASP.MethodsWe used a matched-pair cluster randomized design and included 456 first graders from 14 schools in Norway. From these, 7 ASPs received the intervention (N = 229), while 7 acted as controls (N = 227). Measurements were taken at baseline, immediately post intervention (7 month follow-up) and after a year (19 month follow-up). The primary outcome was moderate to vigorous physical activity (MVPA), which was estimated with predefined cut points of counts per minute (CPM) and expressed as minutes/hour. Secondary outcomes were vigorous and light intensity physical activity (VPA and LPA) and sedentary behavior. The analyses of intervention effects were based on between-group differences in outcome changes between the 3 measurement points and were conducted using a mixed-effects model for repeated measures using categorical time. In exploratory analyses, we investigated gender, baseline body mass index, and baseline CPM as potential effect modifiers.ResultsNo significant intervention effects was observed on MVPA (0.55 min/hour [99% CI -0.55:1.64]) or on the secondary outcomes, min/hour of LPA, VPA or sedentary behavior. Exploratory analyses indicated that among the 50% least physically active children at baseline, children in intervention ASPs reduced sedentary time from baseline to 19 months follow up by 1.67 min/hour (95% CI -3.12:-0.21) compared to the controls.ConclusionsAlthough the intervention did not significantly increase the mean MVPA among the children in the intervention ASPs compared to controls, it did seem to have a small effect by reducing sedentary behavior time among the least active children. An even stronger emphasis on how to identify less active children and support their activity may be needed in order to increase their PA and further reduce sedentary behavior time.Trial registrationClinicalTrials; NCT02954614, Registered 3 November 2016, −Retrospectively registered, first participant enrolled August 2016

Physical Activity and Enjoyment in Parent–Child Dyads During Shared Physical Activity

ABSTRACT Purpose: The purpose of this study was to compare objectively-measured physical activity (PA) and enjoyment of five shared PAs in parent-child dyads. Method: Thirty-one parent-child dyads (mean±SD; age, parents: 38.0 ± 6.6 years, children: 5.9 ± 1.7 years) completed separate PA sessions, which included five standardized PAs (brisk walking, jumping games, dancing, body-weight exercises, and tag games) in random order for each dyad. Parent and child moderate-to-vigorous PA (MVPA) and accelerometer counts per minute (CPM) were measured using Actigraph GT9X activity monitors. The Visual Analog Scale was used to assess enjoyment of children and parents. Repeated measures ANOVAs and paired t-tests determined differences in PA within and between children and parents for the activities, respectively. Friedman Tests with post hoc Wilcoxon signed-rank tests determined significant differences in enjoyment across the activities for children and parents and Wilcoxon signed-rank tests compared enjoyment between children and parents for each PA. Results: Jumping games resulted in the highest proportion of time spent in MVPA and highest overall CPM for children and parents (p < .05). Compared to parents, children spent proportionally more time in MVPA during jumping games, body-weight exercises, and tag games (all, p < .05). Tag games were the most enjoyable PA for children and parents (p < .05). Children enjoyed body-weight exercises more than parents (p < .05). Conclusions: Future indoor PA programs and research interventions that include parent-child dyads should consider implementing jumping games, body-weight exercises, and tag games during shared PA, which resulted in higher MVPA and enjoyment by both children and parents when compared to walking and dancing.

Depressive symptoms and objectively measured physical activity and sedentary behaviour throughout adolescence: a prospective cohort study

SummaryBackgroundIdentifying modifiable risk factors is essential to reduce the prevalence adolescent depression. Self-report data suggest that physical activity and sedentary behaviour might be associated with depressive symptoms in adolescents. We examined associations between depressive symptoms and objectively measured physical activity and sedentary behaviour in adolescents.MethodsFrom a population-based cohort of adolescents whose mothers were invited to participate in the Avon Longitudinal Study of Parents and Children (ALSPAC) study, we included participants with at least one accelerometer recording and a Clinical Interview Schedule-Revised (CIS-R) depression score at age 17·8 years (reported as age 18 years hereafter). Amounts of time spent in sedentary behaviour and physical activity (light or moderate-to-vigorous) were measured with accelerometers at around 12 years, 14 years, and 16 years of age. Total physical activity was also recorded as count per minute (CPM), with raw accelerometer counts averaged over 60 s epochs. Associations between the physical activity and sedentary behaviour variables and depression (CIS-R) scores at age 18 years were analysed with regression and group-based trajectory modelling.Findings4257 adolescents from the 14 901 enrolled in the ALSPAC study had a CIS-R depression score at age 18 years. Longitudinal analyses included 2486 participants at age 12 years, 1938 at age 14 years, and 1220 at age 16 years. Total follow-up time was 6 years. Total physical activity decreased between 12 years and 16 years of age, driven by decreasing durations of light activity (mean 325·66 min/day [SD 58·09] at 12 years; 244·94 min/day [55·08] at 16 years) and increasing sedentary behaviour (430·99 min/day [65·80]; 523·02 min/day [65·25]). Higher depression scores at 18 years were associated with a 60 min/day increase in sedentary behaviour at 12 years (incidence rate ratio [IRR] 1·111 [95% CI 1·051–1·176]), 14 years (1·080 [1·012–1·152]), and 16 years of age (1·107 [1·015–1·208]). Depression scores at 18 years were lower for every additional 60 min/day of light activity at 12 years (0·904 [0·850–0·961]), 14 years (0·922 [0·857–0·992]), and 16 years of age (0·889 [0·809–0·974]). Group-based trajectory modelling across 12–16 years of age identified three latent subgroups of sedentary behaviour and activity levels. Depression scores were higher in those with persistently high (IRR 1·282 [95% CI 1·061–1·548]) and persistently average (1·249 [1·078–1·446]) sedentary behaviour compared with those with persistently low sedentary behaviour, and were lower in those with persistently high levels of light activity (0·804 [0·652–0·990]) compared with those with persistently low levels of light activity. Moderate-to-vigorous physical activity (per 15 min/day increase) at age 12 years (0·910 [0·857–0·966]) and total physical activity (per 100 CPM increase) at ages 12 years (0·941 [0·910–0·972]) and 14 years (0·965 [0·932–0·999]), were negatively associated with depressive symptoms.InterpretationSedentary behaviour displaces light activity throughout adolescence, and is associated with a greater risk of depressive symptoms at 18 years of age. Increasing light activity and decreasing sedentary behaviour during adolescence could be an important target for public health interventions aimed at reducing the prevalence of depression.FundingDetails of funding are provided in the Acknowledgments.

Consequences of Choosing Different Settings When Processing Hip-Based Accelerometry Data From Older Adults: A Practical Approach Using Baseline Data From the SITLESS Study

Accurately measuring older adults’ physical activity (PA) and sedentary behavior (SB) using accelerometers is essential, as both are important markers of health. This study aimed to highlight how steps taken during data processing may affect key hip-based accelerometry outcomes in older adults, using a selection of baseline accelerometry data (n = 658) from the SITLESS study. Different analytical parameters tested included wear-time algorithms, use of low-frequency extension (LFE) filter, epoch length, and minimum and maximum daily wear-time thresholds. These were compared against vertical axis counts per minute (CPM), vector magnitude (VM) CPM, SB, light PA, moderate-to-vigorous PA, step counts, and wear-time percentage. Differences in settings across the analytical parameters were assessed using paired sample t-tests and repeated measures ANOVAs using Bonferroni correction. Using the “Choi” versus “Troiano” wear-time algorithm resulted in a higher percentage wear-time. Most SB and PA outcomes were significantly different across wear-time algorithms (p &lt; .001). This was similar when using the LFE filter versus normal filter (p &lt; .001). Using 10-second epoch length increased daily SB time (between +75.7 and +79.2 minutes) compared to 60-second. Most SB and PA outcomes significantly changed comparing minimum-wear-time thresholds of 360, 480, 600, and 720 minutes per day (p &lt; .001). Applying a log-diary with a ≥1140-minute threshold had a significant impact on vertical axis CPM, VM CPM, SB, and light PA outcomes (p &lt; .001). This study demonstrates the potential variability in the number of participants being included in studies and reported SB and PA levels when processing older adults’ accelerometry data dependent on the analytical procedures utilized.

Abstract TMP23: Inflammasome-derived Caspase-1 is Elevated in the Cerebrospinal Fluid of Subarachnoid Hemorrhage Patients and Correlated to Outcome

Introduction: The role of neuroinflammation following aneurysmal subarachnoid hemorrhage (SAH) and its relationship to outcome is the subject of many ongoing studies. The proteolytic enzyme, caspase-1, activated by the inflammasome complex, is known to contribute to numerous downstream pro-inflammatory effects. In this study, we investigated caspase-1 activity in the cerebrospinal fluid (CSF) of SAH patients and its association to outcome. Methods: SAH patients were recruited from a regional stroke referral center. CSF samples from 18 SAH subjects were collected via an external ventricular drain and obtained within 72 hours of the onset of symptoms. For control subjects, we collected the CSF from 9 patients undergoing lumbar puncture with normal CSF and normal brain MRI. Caspase-1 activity was measured using commercially available luminescence assays. SAH subjects were categorized at hospital discharge into those with good outcomes (Glasgow Outcome Scale, GOS, of 4-5) and poor outcomes (GOS of 1-3). The levels of caspase-1 activity in various groups were analyzed using Mann-Whitney and Pearson correlation tests. Caspase-1 activity was also adjusted by initial severity of bleed using analysis of covariance (ANCOVA). Results: Caspase-1 levels from SAH patients were significantly higher than that measured from the control group (mean 1.06x10-2 vs 1.90x10-3 counts per second (CPS)/μl*min), p = 0.0002). Within the SAH group, 10 patients (55.6%) had good outcomes and 8 patients (44.4%) had poor outcomes. Caspase-1 activity was significantly higher in the poor outcome group (mean 1.54x10-2 vs 1.60x10-3 CPS/μl*min), p = 0.0012). Additionally, caspase-1 activity had a statistically significant correlation with GOS score (r = -0.60; p = 0.0100). When adjusted for initial severity of bleed, the difference in caspase-1 activity in good vs. poor outcome remained significant (adjusted mean 7.10x10-3 vs. 2.54x10-2 CPS/μl*min, p=0.004). Conclusions: The inflammasome-dependent protein caspase-1 is elevated in CSF early after SAH and higher in those with poor functional outcome. Inflammasome activity therefore may serve as a novel biomarker to predict outcome shortly after aneurysm rupture.

Objectively-measured sedentary time and physical activity in a bi-ethnic sample of young children: variation by socio-demographic, temporal and perinatal factors

BackgroundEvidence suggests that South Asian school-aged children and adults are less active compared to the white British population. It is unknown if this generalises to young children. We aimed to describe variability in levels of physical activity and sedentary time in a bi-ethnic sample of young children from a deprived location.MethodsThis observational study included 202 South Asian and 140 white British children aged 1.5 to 5y, who provided 3181 valid days of triaxial accelerometry (Actigraph GT3X+). Variability in sedentary time and physical activity levels were analysed by linear multilevel modelling. Logistic multilevel regression was used to identify factors associated with physical inactivity (failing to perform ≥180 min of total physical activity including ≥60 min moderate-to-vigorous physical activity (MVPA) per day).ResultsThere were no significant ethnic differences in the overall levels of behaviours; South Asian and white British children spent half of daily time sedentary, just over 40% in light physical activity, and the remaining 7.5 to 8% of time in MVPA. Sedentary time was lower and physical activity levels were higher in older children, and levels of MVPA and vector magnitude counts per minute (CPM) were higher on weekends compared to weekdays. In South Asian children, sedentary time was lower on weekends. Sedentary time was lower and physical activity levels were higher in spring compared to winter in white British children, and in all seasons compared to winter in South Asian children. South Asian children born at high birth weight performed more MVPA, and in both ethnicities there was some evidence that children with older mothers were more sedentary and less active. Sedentary time was higher and light physical activity was lower in South Asian children in the highest compared to the lowest income families. South Asian girls performed less MVPA, registered fewer vector magnitude CPM, and were 3.5 times more likely to be physically inactive than South Asian boys.ConclusionsSedentary time and physical activity levels vary by socio-demographic, temporal and perinatal characteristics in young children from a deprived location. South Asian girls have the most to gain from efforts to increase physical activity levels.Trial registrationThe Pre-schoolers in the Playground (PiP) pilot randomized controlled trial is registered with the ISRCTN (ISRCTN54165860; http://www.isrctn.com).

Accelerometer-assessed outdoor physical activity is associated with meteorological conditions among older adults: Cross-sectional results from the OUTDOOR ACTIVE study.

Meteorological conditions are potential determinants of physical activity (PA). A profound understanding of the determinants of PA behaviour is required for PA promotion. This study examined the association between accelerometer-assessed PA and meteorological conditions among older adults. This cross-sectional study included data of 577 adults aged 65-75 years living in Bremen, Germany (52% female; 3278 days). PA was measured with accelerometers for seven consecutive days (10/15-08/16). A threshold of 240 lx was used to differentiate between outdoor physical activity (OPA) and indoor physical activity (IPA). Linear mixed models estimated the association between PA (daily accelerometer counts per minute (CPM)) and meteorological factors (temperature, cloud cover, wind, and no precipitation) derived by principal component analysis. The analyses showed associations between PA in CPM and the meteorological factors temperature (93.7; 95%-CL: 64.9, 122.5) and no precipitation (48.4; 95%-CL: 19.8, 77.0) in women and wind (-40.3; 95%-CL: -59.7, -20.8) and no precipitation (30.1; 95%-CL: 5.6, 54.6) in men. After distinguishing in OPA and IPA for a subsample of 128 participants (473 days), the sex differences were no longer present. OPA in CPM was associated with temperature (women: 174.5; 95%-CL: 81.3, 267.6; men: 183.3; 95%-CL: 81.2, 285.4), cloud cover (women: -153.0; 95%-CL: -200.3, -105.7; men: -123.2; 95%-CL: -174.7, -71.7), and wind (women: -118.6; 95%-CL: -189.6; -47.7; men: -96.9; 95%-CL: -177.0, -16.7). No association between OPA and no precipitation was found (women: 2.9; 95%-CL: -89.0, 94.8; men: -17.1; 95%-CL: -116.7, 82.4). The results of this study emphasize the importance of meteorological conditions as environmental determinants of PA among older adults. Meteorological conditions should be accounted for in the unbiased assessment of habitual PA and the development of PA promotion programs. Future research should focus on the associations of OPA and IPA with meteorological conditions in different climatic regions.

Intensidades de actividad física en juegos estructurados y activos en niños entre 6 y 12 años

Introducción: muchos niños no alcanzan las recomendaciones internacionales respecto a los niveles de actividad física (AF) relacionados con la salud. El juego estructurado y activo sería una gran estrategia para incrementar la AF. El objetivo fue describir intensidades de af alcanzadas en juegos estructurados seleccionados, y su relación con la recomendación de af para niños. Materiales y métodos: participaron 30 niños normopeso (20 varones y 10 mujeres), de estos grupos etarios: 6-7, 8-9 y 10-12 años. Realizaron 32 juegos de 6 min 50 s (± 1 min 42 s) de duración cada uno, en seis sesiones, y con pausas de 5-6 min interjuegos. La intensidad de af fue determinada por observación sistemática (SOFIT) y acelerometría, categorizando la intensidad de AF según puntos de corte en cuentas por minuto (CPM). Se calcularon medias y ds para variables de acelerometría, CPM y SOFIT. Se realizaron contrastes entre sexos y grupos etarios, considerando el grupo total y por cada juego. Se correlacionaron variables de acelerometría con las de sofit. La significancia fue p &lt;0,05. Resultados: diez juegos pertenecen a af moderada y 22, al límite superior de ligera. Hubo diferencias significativas, para CPM, entre 8-9 y 6-7 años, y entre sexos, en cinco juegos. Se correlacionó af moderada y vigorosa y CMP (r = 0,36; p = 0,04). Conclusiones: estos juegos, respecto a intensidad de af (10 en categoría moderada y 22 en límite superior de ligera), revelan un aporte sustantivo a las recomendaciones de AF para niños.

Gamma Dose Rate Measurement Using RadFET

Radiation-sensitive field-effect transistors (RadFET) are generally known for the measurement of total ionizing dose (TID) from gamma radiations. The use of an RadFET as a TID sensor is indispensable because of its characteristic dose rate-independent response. The only drawback with the RadFET, which we consider to be important, was its inability to measure the dose rate. We report here a novel methodology to extract an instantaneous dose rate information from the indigenous RadFET, which has been designed to measure an integral dose in the range from 10 mGy to 10 Gy. The methodology has enabled us to achieve a dose rate measurement sensitivity of 1838±9 counts per second (CPS) at 1±0.05 Gy/h for 60Co irradiation. The minimum dose rate that could be determined using the indigenous RadFET is 0.5 mGy/h, which is approximately three orders of magnitude better than reported to date using an RadFET dosimeter.

Physical activity and sedentary behaviour in children with spina bifida.

To describe active and sedentary time in children with spina bifida and to compare their physical activity on weekdays versus weekends. In this exploratory cross-sectional study, data from 13 Canadian and 22 Dutch children with spina bifida (14 females, 21 males; mean age 10y 11mo, standard deviation [SD] 3y 6mo, range 5y 6mo-18y; Hoffer classification distribution: community [n=28], household [n=3], non-functional [n=3], and non-ambulator [n=1]) were analysed. Objective measures of physical activity and sedentary behaviour were obtained by using ActiGraph or Actiheart activity monitors. Data for the participants wearing the ActiGraph were compared with age- and sex-matched controls that were developing typically using independent-samples t-tests. Activity data collected on weekdays was compared to those on weekends. ActiGraph data demonstrated children with spina bifida spent more time sedentary (mean [SD] 49.5min/h [5.78]) and less time in moderate to vigorous physical activity (mean [SD] 2.33min/h [1.61]) compared with the typically developing group (mean [SD] 41.0min/h [5.76] and 5.46min/h [2.13], p=0.001 and p<0.001 respectively). For both ActiGraph- and Actiheart-derived data, physical activity and sedentary time were not significantly different between weekdays and weekends. Children with spina bifida have reduced levels of physical activity and increased sedentary behaviour, with no statistical differences seen between weekdays and weekends. Several methodological issues related to activity monitoring warrant consideration when choosing the appropriate method to quantify physical activity and sedentary behaviour. Reduced levels of physical activity and sedentary time were quantified in children with spina bifida. Objective quantification of physical behaviour in ambulatory and non-ambulatory school-aged children with spina bifida is possible.

Revisiting the MotionWatch8©: Calibrating Cut-Points for Measuring Physical Activity and Sedentary Behavior Among Adults With Stroke.

Reduced moderate-to-vigorous physical activity (MVPA) and increased sedentary behavior (SB) are common following stroke, which can limit stroke recovery and contribute to greater cognitive decline. Hence, the MVPA and SB of adults with stroke should be measured concurrently using objective methods. One currently available method for objectively measuring MVPA and SB is the MotionWatch8© (MW8). However, adults with stroke can have significant mobility restrictions (depending on stroke severity) and thus it is important to determine separate MVPA and SB cut-points for adults with stroke, as well as validate separate cut-points: (1) when the MW8 is worn on the stroke affected side compared to the non-affected side; and (2) for adults with mild stroke versus adults with moderate-to-severe stroke. In the current study, we concurrently measured MW8 actigraphy (worn on both the stroke affected side and the non-affected side) and indirect calorimetry during 10 different activities of daily living for 43 adults with stroke (aged 55–87 years). Using intra-class correlations (ICC), we first investigated the agreement of the MW8 when placed on the affected side as compared to the non-affected side for: (1) all participants irrespective of stroke severity; (2) participants with mild stroke, classified as a Fugl Meyer motor score of ≥79/100; and (3) participants with moderate-to-severe stroke (i.e., Fugl Meyer < 79/100). We then determined cut-points for all participants—as well as separate cut-points based on stroke severity—on both the stroke affected side and non-affected side for SB and MVPA using receiver operating characteristic curves. The results of our analyses indicate that the agreement in MW8 output between the stroke affected and non-affected sides was moderate across all participants (ICC = 0.67), as well as for each sub-group (mild stroke: ICC = 0.64; moderate-to-severe stroke: ICC = 0.77). Additionally, the results of our cut-point analyses support using different cut-points for different levels of stroke severity and also for the stroke affected side. We determined the following cut-points: (1) for the affected side, adults with mild stroke have cut-points of SB ≤134 counts per minute (CPM) and MVPA ≥704 CPM, while adults with moderate-to-severe stroke have cut-points of SB ≤281 CPM and MVPA ≥468 CPM; and (2) the non-affected side, adults with mild stroke have cut-points of SB ≤162 CPM and MVPA ≥661 CPM, while adults with moderate-to-severe stroke have cut-points of SB ≤281 CPM and MVPA ≥738 CPM. Hence, these data provide a new measure for concurrently examining the dynamic relationships between MVPA and SB among adults with stroke.

Estimating Sedentary Time from a Hip- and Wrist-Worn Accelerometer.

This study aimed to determine the validity of existing methods to estimate sedentary behavior (SB) under free-living conditions using ActiGraph GT3X+ accelerometers (AG). Forty-eight young (18-25 yr) adults wore an AG on the right hip and nondominant wrist and were video recorded during four 1-h sessions in free-living settings (home, community, school, and exercise). Direct observation videos were coded for postural orientation, activity type (e.g., walking), and METs derived from the Compendium of Physical Activities, which served as the criterion measure of SB (sitting or lying posture, <1.5 METs). Thirteen methods using cut points from vertical counts per minute (CPM), counts per 15-s (CP15s), and vector magnitude (VM) counts (e.g., CPM1853VM), raw acceleration and arm angle (sedentary sphere), Euclidean norm minus one (ENMO) corrected for gravity (mg) thresholds, uni- or triaxial sojourn hybrid machine learning models (Soj1x and Soj3x), random forest (RF), and decision tree (TR) models were used to estimate SB minutes from AG data. Method bias, mean absolute percent error, and their 95% confidence intervals were estimated using repeated-measures linear mixed models. On average, participants spent 34.1 min per session in SB. CPM100, CPM150, Soj1x, and Soj3x were the only methods to accurately estimate SB from the hip. Sedentary sphere and ENMO44.8 overestimated SB by 3.9 and 6.1 min, respectively, whereas the remaining wrist methods underestimated SB (range, 9.5-2.5 min). In general, mean absolute percent error was lower using hip methods compared with wrist methods. Accurate group-level estimates of SB from a hip-worn AG can be achieved using either simpler count-based approaches (CPM100 and CPM150) or machine learning models (Soj1x and Soj3x). Wrist methods did not provide accurate or precise estimates of SB. The development of large open-source free-living calibration data sets may lead to improvements in SB estimates.

Accelerometer-determined Sedentary Time And Physical Activity Across Standard Occupational Categories In CARDIA

PURPOSE High accumulated sedentary time with inadequate physical activity is a common behavioral profile in the United States. Examining differences in activity patterns across occupational categories can distinguish target populations for intervention. METHODS This cross-sectional analysis of Year 20 CARDIA data (2005-6) included participants who had valid accelerometry data (≥4 days with ≥10 hours), reported job and job duties, and were not currently a student (n=2,050). Uniaxial accelerometry data (ActiGraph 7164), including leisure and occupational time, were expressed in 60 second epochs and summarized as: average counts per minute (CPM) and time spent (hours/day) in total sedentary behavior (SED), light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) using Freedson cutpoints. Self-reported job and job duties were categorized into the 23 major groups of 2010 Standard Occupational Classification (SOC) using Occucoder v2.7 followed by adjudication by a trained researcher. Military and forestry categories were excluded because <5 participants reported jobs in those categories. Omnibus group differences were analyzed using ANCOVA adjusted for sex, race, age, education, wear time, center, and BMI. RESULTS Table 1 shows the least and most favorable three SOC groups in each activity category with mean (standard error) reported. P-values represent overall group difference across occupational categories. Building/grounds maintenance had the highest CPM while office and admin support had the lowest. Architecture/engineering had the highest SED while food preparation had the lowest. Food preparation had the most LPA and legal had the least. Construction had the highest MVPA while healthcare support had the lowest. CONCLUSION Activity patterns have large variation across occupational categories, justifying occupation as an important determinant of activity and the workplace as a potential intervention setting.Table 1: Occupational Categories with the Least and Most Favorable CPM, SED, LPA, and MVPA