The relationship between neighbourhood built characteristics, physical activity, and health-related fitness in urban dwelling Canadian adults: A mediation analysis.

OBJECTIVE: Physical activity supportive environments have the potential to promote health-related fitness in adults. However, the extent to which neighbourhood built characteristics promote health-related fitness via physical activity has received little research attention. Therefore, our objective was to estimate the indirect and direct effects between neighbourhood built characteristics and health-related fitness mediated by physical activity. METHODS: Using cross-sectional data collected between 2014 and 2019, we merged neighbourhood built characteristics, physical activity, and health-related fitness variables, derived from two Canadian national databases. Using these data, we estimated sex-stratified covariate-adjusted path models (males: n = 983 to 2796 and females: n = 962 to 2835) to assess if accelerometer-measured light, moderate, and vigorous intensity physical activity mediated associations between objectively measured neighbourhood built characteristics (intersection density, dwelling density, points of interest, and transit density) and health-related fitness (grip strength, jump height, V̇O2max, and flexibility). Across 16 sex-specific models, we estimated 48 indirect and 16 direct effects. RESULTS: Concerning significant associations, for males we found that 16.6% of indirect and 18.8% of direct were negative and 4.2% of indirect and 0% of direct were positive. For females, we found that 12.5% of indirect and 0% of direct were negative and 0% of indirect and 25% of direct effects were positive. CONCLUSIONS: Individual Canadian Active Living Environment built characteristics are positively associated with moderate-intensity physical activity and negatively associated with light-intensity physical activity. Further, associations between activity friendly neighbourhood characteristics and health related-fitness may be distinct from physical activity.

Neighbourhood walkability and greenspace and their associations with health-related fitness in urban dwelling Canadian adults.

OBJECTIVE: Muscular strength and body composition are important components of health-related fitness (HRF). Grip strength and body fat percent, in particular, are associated with chronic disease and affected by health behaviours. Evidence suggests relationships between the neighbourhood built environment (BE) and HRF exist, however, few studies have focused on grip strength and body fat percent. Therefore, our study aimed to estimate the sex-specific associations between the neighbourhood BE, grip strength, and body fat percent among urban-dwelling Canadian adults. METHODS: We analyzed cross-sectional survey and HRF data collected in 2011-2015 from 4052 males and 7841 females (Alberta's Tomorrow Project, Canada). Grip strength and body fat percent were measured via handgrip dynamometry and bioelectrical impedance analysis, respectively. Walkability (Canadian Active Living Index) and greenness (Normalized Difference Vegetation Index) estimates were linked to participant data. Sex-stratified covariate-adjusted linear regression models estimated the associations between the BE and HRF variables. RESULTS: Walkability was negatively associated with grip strength and body fat percent in males (ß -0.21, 95%CI: -0.31 to -0.11 and ß -0.08, 95%CI: -0.15 to -0.02, respectively) and females (ß -0.06, 95%CI: -0.10 to -0.01 and ß -0.08, 95%CI: -0.14 to -0.02, respectively). Greenness was positively associated with grip strength in males (ß 6.99, 95%CI: 3.62 to 10.36) and females (ß 2.72, 95%CI: 1.22 to 4.22) but not with body fat percent. Controlling for physical activity and sitting did not attenuate these associations. CONCLUSION: Characteristics of the neighbourhood BE appear to be associated with muscular strength and body composition, independent of physical activity and sedentary behaviour.

Mediation analysis of the associations between neighbourhood walkability and greenness, accelerometer-measured physical activity, and health-related fitness in urban dwelling Canadians.

OBJECTIVE: To estimate sex-specific associations (total, direct, and indirect effects) between objectively measured neighbourhood walkability and greenness and objectively measured physical activity and health-related fitness including cardiorespiratory and muscular fitness in Canadian adults. METHODS: Neighbourhood walkability (Canadian Active Living Environment) and greenness (Normalized Difference Vegetation Index; NDVI) data were linked to cardiorespiratory (i.e., submaximal step test estimated V̇O2 max) and muscular fitness (i.e., handgrip strength) and accelerometer measured physical activity; Canadian Health Measures Survey). Covariate-adjusted sex-stratified path analyses was conducted to assess if physical activity (light: LPA; moderate: MPA, and; vigorous: VPA) mediated the associations between neighbourhood walkability, NDVI and health-related fitness. Model sample sizes ranged from 987 to 2796 for males and 989 to 2835 for females. RESULTS: Among males, we found indirect effects between neighbourhood walkability and cardiorespiratory fitness via LPA (negative) and VPA (positive). We also found a total effect (negative) between neighbourhood walkability and grip strength and indirect effects between neighbourhood walkability and handgrip strength via LPA (negative) and MPA (negative). Among females, we found a total effect (positive) and direct effect (positive) between neighbourhood walkability and cardiorespiratory fitness, and an indirect effect for neighbourhood walkability and cardiorespiratory fitness via LPA. We found no significant effects related to neighbourhood greenness. CONCLUSIONS: Residing in a neighbourhood with higher walkability may positively affect cardiorespiratory fitness but negatively affect muscular strength. The negative associations between neighbourhood walkability and LPA may offset potential positive associations between neighbourhood walkability and MPA and VPA and their subsequent influence on health-related fitness.

An exploration of parent perceptions of a take-home loose parts play kit intervention during the COVID-19 pandemic.

The restrictions introduced in response to the COVID-19 pandemic affected the regular routines of Canadians, including access to play and physical activity opportunities, while limiting social connections. In response to this, a recreation centre created take-home play kits that contained loose parts with the aim of facilitating unstructured play. Between August 2021 and January 2022, ten parents participated in semi-structured interviews via telephone or videoconferencing platforms that captured their experiences of the take-home play kits. Using Thematic Analysis, we identified themes and subthemes reflecting parent perceptions and experiences of the take-home play kit. Three themes emerged: (1 A forced renaissance of play; (2) Bringing unstructured play home, and; (3) Parenting is child's play. Parents shared how the pandemic resulted in decreased physical activity and social opportunities for their children. The parents described how the take-home play kits supported unstructured play as well as their perspectives on the importance of unstructured play. Parents in our study suggested that a take-home loose parts play kit could be a useful resource to help engage children in unstructured play in both indoor and outdoor environments.

The influence of skeletal muscle mitochondria and sex on critical torque and performance fatiguability in humans.

Critical torque (CT) represents the highest oxidative steady state for intermittent knee extensor exercise, but the extent to which it is influenced by skeletal muscle mitochondria and sex is unclear. Vastus lateralis muscle biopsy samples were collected from 12 females and 12 males -matched for relative maximal oxygen uptake normalized to fat-free mass (FFM) (F: 57.3 (7.5) ml (kg FFM)-1  min-1 ; M: 56.8 (7.6) ml (kg FFM)-1  min-1 ; P = 0.856) - prior to CT determination and performance fatiguability trials. Males had a lower proportion of myosin heavy chain (MHC) I isoform (40.6 (18.4)%) compared to females (59.5 (18.9)%; P = 0.021), but MHC IIa and IIx isoform distributions and protein markers of mitochondrial content were not different between sexes (P > 0.05). When normalized to maximum voluntary contraction (MVC), the relative CT (F: 42.9 (8.3)%; M: 37.9 (9.0)%; P = 0.172) and curvature constant, W' (F: 26.6 (11.0) N m s (N m)-1 ; M: 26.4 (6.5) N m s (N m)-1 ; P = 0.962) were not significantly different between sexes. All protein biomarkers of skeletal muscle mitochondrial content, as well as the proportion of MHC I isoform, positively correlated with relative CT (0.48 < r < 0.70; P < 0.05), and the proportion of MHC IIx isoform correlated positively with relative W' (r = 0.57; P = 0.007). Indices of performance fatiguability were not different between males and females for MVC- and CT-controlled trials (P > 0.05). Greater mitochondrial protein abundance was associated with attenuated declines in potentiated twitch torque for exercise at 60% MVC (P < 0.05); however, the influence of mitochondrial protein abundance on performance fatiguability was reduced when exercise was prescribed relative to CT. Whether these findings translate to whole-body exercise requires additional research. KEY POINTS: The quadriceps critical torque represents the highest intensity of intermittent knee extensor exercise for which an oxidative steady state is attainable, but its relationship with skeletal muscle mitochondrial protein abundance is unknown. Matching males and females for maximal oxygen uptake relative to fat-free mass facilitates investigations of sex differences in exercise physiology, but studies that have compared critical torque and performance fatiguability during intermittent knee extensor exercise have not ensured equal aerobic fitness between sexes. Skeletal muscle mitochondrial protein abundance was correlated with critical torque and fatigue resistance for exercise prescribed relative to maximum voluntary contraction but not for exercise performed relative to the critical torque. Differences between sexes in critical torque, skeletal muscle mitochondrial protein abundance and performance fatiguability were not statistically significant. Our results suggest that skeletal muscle mitochondrial protein abundance may contribute to fatigue resistance by influencing the critical intensity of exercise.

Establishing a Gold Standard for Quantitative Menstrual Cycle Monitoring.

Background and Objectives: The Quantum Menstrual Health Monitoring Study will measure four key reproductive hormones in the urine (follicle-stimulating hormone, FSH; estrone-3-glucuronide, E13G; luteinizing hormone, LH; and pregnanediol glucuronide, PDG) to characterize patterns that predict and confirm ovulation, referenced to serum hormones and the gold standard of the ultrasound day of ovulation in participants with regular cycles. These normal cycles will provide a reference for comparison to irregular cycles in subjects with polycystic ovarian syndrome (PCOS) and athletes. Materials and Methods: Participants will track their menstrual cycles for 3 months and be provided with an at-home urine hormone monitor (Mira monitor) to predict ovulation. The day of ovulation will be confirmed with serial ultrasounds completed in a community clinic. Urine results will be compared to serum hormone values. Other markers of menstrual health, such as bleeding patterns and temperature changes, will be determined using a customized app. Three groups will be recruited. Group 1 will include those with consistent regular cycle lengths (between 24-38 days), and will be compared to two groups with irregular cycle lengths (with increased cycle length variability and longer cycles). Group 2 will include those with polycystic ovarian syndrome (PCOS) with irregular cycles and Group 3 will include individuals participating in high levels of exercise with irregular cycles. Hypothesis: The Mira monitor quantitative urine hormone pattern will accurately correlate with serum hormonal levels and will predict (with LH) and confirm (with PDG) the ultrasound day of ovulation in those with regular cycles as well as those with irregular cycles. Rationale: Once the ultrasound validation is complete, tools like the Mira monitor with a customized app may become a new standard for at-home and remote clinical monitoring of the menstrual cycle without having to use labor-intensive follicular-tracking ultrasound or follow serum hormone changes. Conclusions: Precision monitoring of the menstrual cycle is expected to impact individuals who want to increase their menstrual health literacy and guide decisions about fertility.

Spread of Makoyoh'sokoi (Wolf Trail): a community led, physical activity-based, holistic wellness program for Indigenous women in Canada.

Globally, Indigenous populations have been impacted by colonization. Populations who have endured colonization are at higher risk of developing chronic diseases. Canada's Truth and Reconciliation Commission emphasizes reducing barriers to participation in physical activity and recommends the creation of culturally relevant and supportive policies and programing. Physical activity is a cornerstone in health promotion and public health to combat chronic diseases; however, in Canada, Indigenous developed physical activity programing is sparse, and those targeting women are non-existent in some regions. Makoyoh'sokoi (The Wolf Trail Program) is an 18-week long, holistic wellness program that was created by and for Indigenous women. Makoyoh'sokoi was developed by communities following extensive consultation and cultural oversight. Makoyoh'sokoi's core program consists of 12 weeks of weekly physical activity programing and health education, followed by another 6 weeks of weekly health education. Notably, communities have control over the program to modify based on individual needs and challenges. Programs commence and conclude with a ceremony with Elders giving a blessing and opening each other to connection. The goals of Makoyoh'sokoi are to empower women, improve health outcomes, and to implement a sustainable program by training a network of community members in their respective communities to facilitate delivery.

Physical activity for children with autism spectrum disorder during COVID-19 pandemic.

In December 2019, Coronavirus disease (COVID-19) emerged in Wuhan, China that culminated in a serious pandemic condition. Physical distancing restrictions were a significant component of the public health emergency response to the COVID-19 pandemic. For children and youth, these restrictions included safety measures that impacted daily activities related to physical activity (PA) participation worldwide. Preliminary evidence suggests that in children with special needs such as Autism Spectrum Disorder (ASD), COVID-19 restrictions may have disproportionally led to reduced levels of PA. The aim of this study was to review the benefits of PA for children with ASD and suggest Home PA Program examples for Children with ASD during COVID-19 pandemic and the quarantine time.

An Observational Study on Play and Physical Activity Associated with a Recreational Facility-Led Park-Based "Loose Parts" Play Intervention during the COVID-19 Pandemic.

Play is a human right, yet opportunities for unstructured play are declining. The COVID-19 pandemic further reduced children's play opportunities. We conducted an observational study of a novel community-based intervention (play hubs) that facilitated unstructured play by offering loose parts in parks (Calgary, Canada) during the pandemic. Our descriptive study included systematic observation using the System for Observing Children's Activity and Relationships During Play (SOCARP) and Tool for Observing Play Outdoors (TOPO) to capture physical activity, play, and social and environment interactions among children participating in the play hubs for 10-weeks in 2021 (n = 160) and 2022 (n = 147). Play hub attendance was low. Most children observed were aged 5 to 12 years (2021: 93% and 2022 98%), with boys and girls represented (2021: 58% male/42% female and 2022: 52% male/48% female). Standing, sitting, and moderate activity were common activities. Physical, exploratory, and expressive play were common, while digital, bio, and rule-based play were less common. Children typically played alone or in small groups and engaged with loose parts or played in the open spaces. The play hubs encouraged unstructured play and promoted positive social interactions among children, despite the challenges of implementing a community-based intervention under pandemic public health restrictions.

Validity and Reliability of the Pre-Adolescent Dance Injury and Participation Questionnaire (PADIP-Q).

INTRODUCTION: Dancers generally begin training in a variety of styles at a young age. Across ages and levels of participation, dancers are at high risk for injury. Most available injury surveillance tools, however, have been developed for adult populations. Valid, reliable tools that monitor injury and exposure of pre-adolescent dance populations are limited. Therefore, the purpose of this study was to determine the validity and reliability of a dance injury and participation questionnaire specifically for pre-adolescent private studio dancers. METHODS: Four stages of validity and reliability testing assessed a novel questionnaire: initial design based on previous literature, expert panel review, cognitive interviews, and test-retest reliability. The target population was 8 to 12-year-olds who participate in at least 1 class/week at a private studio. Feedback from a panel review and cognitive interviews was incorporated. Test-retest analyses included Cohen's kappa coefficients and percent agreement for categorical variables, and intraclass correlation coefficients [ICCs (3,1)], absolute mean difference (md) and Pearson's correlation coefficients (r) for numerical data. RESULTS: The final questionnaire was comprised of 4 sections: demographics, dance training history, current dance participation (previous 1-year and 4-months), and dance-related injury history (previous 1-year and 4-months). Items with categorical responses estimated kappa coefficients from 0.32 to 1.00, and percent agreement between 81% and 100%. For items with numeric responses, ICC estimates ranged between .14 and 1.00, r values between .14 and 1.00, and the largest absolute md was 0.46. The 4-month recall sections revealed higher agreement than the 1-year sections. CONCLUSION: This valid pre-adolescent dance injury and participation questionnaire demonstrates good to excellent reliability across all items. To support participant completions, assistance from a parent/guardian is suggested. To move dance epidemiology research forward among private studio dancers aged 8 to 12 years, employment of this questionnaire is therefore recommended.

Early breast cancer survival of black and white American women with equal diagnostic and therapeutic management.

PURPOSE: Breast cancer (BC) survival favors White versus Black Americans despite advances in screening and treatment. We hypothesized that these differences were dependent upon quality of care by analyzing long-term outcomes of 3139 early BC patients at our quaternary care center where uniform access and management of BC is provided to women irrespective of race. METHODS: Prospectively collected data for clinical stage I-II BC patients from our quaternary care cancer center were analyzed, focusing on disease-specific survival (DSS). Subgroup analyses included the overall cohort, triple-negative BC (TNBC), non-TNBC and HER2/neu positive patients. Multivariable analyses to evaluate associations of variables with DSS were performed for each subgroup. RESULTS: The overall cohort consisted of 3139 BC patients (1159 Black, 1980 White). Black and White patients did not differ by most baseline variables. Black patients had higher rates of TNBC (18% versus 10%, p < 0.0001). Kaplan-Meier analysis of all subgroups (overall, TNBC, non-TNBC, HER2/neu positive) did not reveal DSS differences between Black and White patients. Multivariable analysis of subgroups also did not find race to be associated with DSS. CONCLUSION: In this large, carefully controlled, long term, single-institution prospective cohort study DSS in Black and White early BC patients with equal access to high quality care, did not differ. While BC patients with adverse molecular markers did slightly worse than those with more favorable markers, there is no observable difference between Black and White women with the same markers. These observations support the conclusion that equal access to, and quality, of BC care abolishes racial disparities in DSS.

The neighbourhood built environment and health-related fitness: a narrative systematic review.

BACKGROUND: There is increasing evidence demonstrating the importance of the neighbourhood built environment in supporting physical activity. Physical activity provides numerous health benefits including improvements in health-related fitness (i.e., muscular, cardiorespiratory, motor, and morphological fitness). Emerging evidence also suggests that the neighbourhood built environment is associated with health-related fitness. Our aim was to summarize evidence on the associations between the neighbourhood built environment and components of health-related fitness in adults. METHODS: We undertook a systematic review following PRISMA guidelines. Our data sources included electronic searches in MEDLINE, Embase, CINAHL, Web of Science, SPORTDiscus, Environment Complete, ProQuest Dissertations and Theses, and Transport Research International Documentation from inception to March 2021. Our eligibility criteria consisted of observational and experimental studies estimating associations between the neighbourhood built environment and health-related fitness among healthy adults (age ≥ 18 years). Eligible studies included objective or self-reported measures of the neighbourhood built environment and included either objective or self-reported measures of health-related fitness. Data extraction included study design, sample characteristics, measured neighbourhood built environment characteristics, and measured components of health-related fitness. We used individual Joanna Briggs Institute study checklists based on identified study designs. Our primary outcome measure was components of health-related fitness (muscular; cardiorespiratory; motor, and morphological fitness). RESULTS: Twenty-seven studies (sample sizes = 28 to 419,562; 2002 to 2020) met the eligibility criteria. Neighbourhood destinations were the most consistent built environment correlate across all components of health-related fitness. The greatest number of significant associations was found between the neighbourhood built environment and morphological fitness while the lowest number of associations was found for motor fitness. The neighbourhood built environment was consistently associated with health-related fitness in studies that adjusted for physical activity. CONCLUSION: The neighbourhood built environment is associated with health-related fitness in adults and these associations may be independent of physical activity. Longitudinal studies that adjust for physical activity (including resistance training) and sedentary behaviour, and residential self-selection are needed to obtain rigorous causal evidence for the link between the neighbourhood built environment and health-related fitness. TRIAL REGISTRATION: Protocol registration: PROSPERO number CRD42020179807.

Effectiveness of an 8-Week Physical Activity Intervention Involving Wearable Activity Trackers and an eHealth App: Mixed Methods Study.

BACKGROUND: Health-promotion interventions incorporating wearable technology or eHealth apps can encourage participants to self-monitor and modify their physical activity and sedentary behavior. In 2020, a Calgary (Alberta, Canada) recreational facility developed and implemented a health-promotion intervention (Vivo Play Scientist program) that provided a commercially available wearable activity tracker and a customized eHealth dashboard to participants free of cost. OBJECTIVE: The aim of this study was to independently evaluate the effectiveness of the Vivo Play Scientist program for modifying physical activity and sedentary behavior during the initial 8 weeks of the piloted intervention. METHODS: Our concurrent mixed methods study included a single-arm repeated-measures quasiexperiment and semistructured interviews. Among the 318 eligible participants (≥18 years of age) registered for the program, 87 completed three self-administered online surveys (baseline, T0; 4 weeks, T1; and 8 weeks, T2). The survey captured physical activity, sedentary behavior, use of wearable technology and eHealth apps, and sociodemographic characteristics. Twenty-three participants were recruited using maximal-variation sampling and completed telephone-administered semistructured interviews regarding their program experiences. Self-reported physical activity and sedentary behavior outcomes were statistically compared among the three time points using Friedman tests. Thematic analysis was used to analyze the interview data. RESULTS: The mean age of participants was 39.8 (SD 7.4) years and 75% (65/87) were women. Approximately half of all participants had previously used wearable technology (40/87, 46%) or an eHealth app (43/87, 49%) prior to the intervention. On average, participants reported wearing the activity tracker (Garmin Vivofit4) for 6.4 (SD 1.7) days in the past week at T1 and for 6.0 (SD 2.2) days in the past week at T2. On average, participants reported using the dashboard for 1.6 (SD 2.1) days in the past week at T1 and for 1.0 (SD 1.8) day in the past week at T2. The mean time spent walking at 8 weeks was significantly higher compared with that at baseline (T0 180.34 vs T2 253.79 minutes/week, P=.005), with no significant differences for other physical activity outcomes. Compared to that at baseline, the mean time spent sitting was significantly lower at 4 weeks (T0 334.26 vs T1 260.46 minutes/day, P<.001) and 8 weeks (T0 334.26 vs T2 267.13 minutes/day, P<.001). Significant differences in physical activity and sitting between time points were found among subgroups based on the household composition, history of wearable technology use, and history of eHealth app use. Participants described how wearing the Vivofit4 device was beneficial in helping them to modify physical activity and sedentary behavior. The social support, as a result of multiple members of the same household participating in the program, motivated changes in physical activity. Participants experienced improvements in their mental, physical, and social health. CONCLUSIONS: Providing individuals with free-of-cost commercially available wearable technology and an eHealth app has the potential to support increases in physical activity and reduce sedentary behavior in the short term, even under COVID-19 public health restrictions.

Does a history of youth sport-related knee injury still impact accelerometer-measured levels of physical activity after 3-12 years?

OBJECTIVES: To examine accelerometer-measured physical activity (PA) in individuals with a knee injury history and controls and the association of moderate to vigorous PA (MVPA) with self-reported and performance measures of knee function. DESIGN: Historical cohort. PARTICIPANTS: Participants with a 3-12 year history of youth sport-related knee injury and matched controls. MAIN OUTCOME MEASURES: MVPA (Actigraph GT3x-BT), Knee Injury and Osteoarthritis Outcome Score (KOOS), Triple Single-Leg Hop, Y-Balance and isometric knee strength was measured. Regression analyses examined differences in PA and the association between MVPA and knee function, adjusted for injury history, sex and time since injury. RESULTS: Participants (42 injured, 43 controls) had a median age of 23.4 (range 16-29) years. The previously injured group spent less daily adjusted minutes in MVPA [-13.5 (95% CI -25.6, -1.4)] than controls, and females had 10.8 min (95% CI -20.2, -1.4) less MVPA than males. Higher MVPA was associated with better KOOS sport and recreation [ß = 0.05, 95% CI (0.01, 0.09)] adjusted for injury history. No other associations were observed. CONCLUSION: Previously injured youth participated in less MVPA compared to controls 3-12 years later. Lower MVPA is associated with poorer self-reported sport and recreation knee function which may have long-term negative health consequences.

The PshX subunit of the photochemical reaction center from Heliobacterium modesticaldum acts as a low-energy antenna.

The anoxygenic phototrophic bacterium Heliobacterium modesticaldum contains a photochemical reaction center protein complex (called the HbRC) consisting of a homodimer of the PshA polypeptide and two copies of a newly discovered polypeptide called PshX, which is a single transmembrane helix that binds two bacteriochlorophyll g molecules. To assess the function of PshX, we produced a ∆pshX strain of Hbt. modesticaldum by leveraging the endogenous Hbt. modesticaldum Type I-A CRISPR-Cas system to aid in mutant selection. We optimized this system by separating the homologous recombination and CRISPR-based selection steps into two plasmid transformations, allowing for markerless gene replacement. Fluorescence and low-temperature absorbance of the purified HbRC from the wild-type and ∆pshX strains showed that the bacteriochlorophylls bound by PshX have the lowest site energies in the entire HbRC. This indicates that PshX acts as a low-energy antenna subunit, participating in entropy-assisted uphill energy transfer toward the P800 special bacteriochlorophyll g pair. We further discuss the role that PshX may play in stability of the HbRC, its conservation in other heliobacterial species, and the evolutionary pressure to produce and maintain single-TMH subunits in similar locations in other reaction centers.

Stress levels in university/college female students at the start of the academic year.

Objectives: To investigate stress levels among Canadian female university students and determine cutoff scores for low, moderate, and high stress in this population. PARTICIPANTS: Hundred female undergraduates, mean age of 20.3 (SD = 1.8) years. METHODS: A cross-sectional design was employed and students were approached in hallways at the start of the 2018 academic year and asked to complete a Student-life Stress Inventory (SSI). RESULTS: Mean stress score was 138.2 (SD = 28.9) out of 255; 53% reported high exposure to stress with 80% reporting low behavioral response to stress. CONCLUSION: Self-report exposure to stress was high in many at the semester start but manageable and stress scores were similar to other campuses that administered the SSI. A study design that uses qualitative data to enhance the survey findings while longitudinal tracking over the academic year may better inform the extent of student stress exposure and how students effectively cope with this exposure.

Effect of Intensity on Changes in Cardiac Autonomic Control of Heart Rate and Arterial Stiffness After Equated Continuous Running Training Programs.

Background: It is well known that exercise training has positive effects on both cardiac autonomic function and arterial stiffness (AS). However, it is not clear that which exercise training variables, intensity or volume, or both, play a crucial role in this regard. This study investigates the chronic effects of high-volume moderate-intensity training (HVMIT) and low-volume high-intensity training (LVHIT) on heart rate variability (HRV) and AS in sedentary adult men. Materials and Methods: Notably, 45 males (age: 42 ± 5.7 years) were randomly assigned to a control (n = 15), HVMIT (n = 15), or LVHIT (n = 15). The HVMIT group ran three times per week on a treadmill at 50-60% of VO2max for 45-60 min, while the LVHIT trained at 70-85% of VO2max for 25-40 min. Both training protocols were equated by caloric expenditure. HRV, pulse wave velocity (PWV), hemodynamic variables, and body composition were measured before and after 12 weeks. Results: Both protocols (i.e., HVMIT and LVHIT) significantly increased the SD of normal sinus beat intervals (SDNN) and high-frequency (HF) bands (p < 0.05) after 12 weeks. Whereas the low-frequency (LF)-HF ratio decreased significantly in both training protocols (p < 0.05); however, these changes were significantly greater in the LVHIT protocol (p < 0.05). Furthermore, the root mean square of successive RR interval differences (RMSSD) significantly increased only in the LVHIT (p < 0.05). Moreover, a significant decrease in LF and PWV was only observed following the LVHIT protocol (p < 0.05). Some measures of HRV and PWV were significantly correlated (r = 0.275-0.559; p < 0.05). Conclusion: These results show that the LVHIT protocol was more efficient for improving HRV variables and PWV than the HVMIT protocol after 12 weeks of continuous running training. Interestingly, changes in some HRV parameters were related to changes in PWV. Further studies should elaborate on the link between central and peripheral cardiovascular adaptations after continuous and intermittent training regimens differing in intensity.

Stroke and Athletes: A Scoping Review.

Stroke (i.e., cerebrovascular accident) affects one in 10,000 people between the ages of 14 and 45; however, very little is known about the frequency and type of stroke that occurs in athletes. The risk of injury to the neurovascular structures may depend on the type of sport involvement, although, sport-specific incidence rates are not known. Therefore, the goal of our scoping review was to provide some guidance to better inform the development of a context-fit stroke model by summarizing studies on a broad research topic related to stroke or cerebrovascular accident in sport based on a strict athlete definition. We used the guidance of Arksey and O'Malley's five-stage-process for a scoping review. Databases included MEDLINE(R) Epub Ahead of Print, In-Process & Other Non- Indexed Citations, Ovid MEDLINE(R) Daily and Ovid MEDLINE(R), and Embase (OVID databases); CINAHL Plus with Full Text, SportDiscus with Full Text (Ebsco databases); and Scopus. Publication dates were from 1979-2020 across nine different countries resulting in 39 individual cases of stroke with an athlete age range of 14-56 years (95% male). The major inciting event(s) prior to stroke onset were headaches (38.4%), head trauma (30.7%), and neck injury and/or vertebral artery dissection (20.5%). Several sporting activities were represented with American football as the most prevalent (30.7%). In summary, we found that sports with an aspect of impact, collision, or microtrauma can lead to subsequent stroke. These sport-related traumatic events were often difficult to diagnose because of the longer interval before ischemia occurred. Therefore, health care providers should be particularly attuned to the possibility of stroke when evaluating athletes presenting with or without neurological deficit.

Perceived anxiety and physical activity behaviour changes during the early stages of COVID-19 restrictions in community-dwelling adults in Canada: a cross-sectional study.

OBJECTIVES: The COVID-19 pandemic changed daily routines, including physical activity, which could influence physical and mental health. In our study, we describe physical activity and sedentary behaviour patterns in relation to the pandemic and estimate associations between anxiety and physical activity and sedentary behaviour in community-dwelling adults. DESIGN: Cross-sectional study. SETTING: Calgary, Alberta, Canada. PARTICIPANTS: Between April and June 2020, a random sample of 1124 adults (≥18 years) completed an online questionnaire. PRIMARY AND SECONDARY OUTCOMES: The online questionnaire captured current walking, moderate intensity, vigorous intensity and total physical activity and sedentary behaviour (ie, sitting and leisure-based screen time), perceived relative changes in physical activity, sedentary and social behaviours since the pandemic, perceived seriousness and anxiety related to COVID-19, and sociodemographic characteristics. Differences in sociodemographic characteristics, perceived relative change in behaviour and current physical activity and sedentary behaviour were compared between adults with low and high anxiety. RESULTS: Our sample (n=1047) included more females (60.3%) and fewer older adults (19.2%). Most participants (88.4%) considered COVID-19 as extremely or very serious and one-third (32.9%) felt extremely or very anxious. We found no differences (p>0.05) in current physical activity or sedentary behaviour by anxiety level. The largest perceived change in behaviours included social distancing, driving motor vehicles, use of screen-based devices, watching television and interactions with neighbours. We found anxiety-related differences (p<0.05) in perceived changes in various behaviours. CONCLUSIONS: Changes in physical activity, sedentary behaviour and social behaviour occurred soon after the COVID-19 pandemic was declared, and some of these changes differed among those with low and high anxiety.

Deletion of the cytochrome bc complex from Heliobacterium modesticaldum results in viable but non-phototrophic cells.

The heliobacteria, a family of anoxygenic phototrophs, possess the simplest known photosynthetic apparatus. Although they are photoheterotrophs in the light, the heliobacteria can also grow chemotrophically via pyruvate metabolism in the dark. In the heliobacteria, the cytochrome bc complex is responsible for oxidizing menaquinol and reducing cytochrome c553 in the electron flow cycle used for phototrophy. However, there is no known electron acceptor for the mobile cytochrome c553 other than the photochemical reaction center. We have, therefore, hypothesized that the cytochrome bc complex is necessary for phototrophy, but unnecessary for chemotrophic growth in the dark. We used a two-step method for CRISPR-based genome editing in Heliobacterium modesticaldum to delete the genes encoding the four major subunits of the cytochrome bc complex. Genotypic analysis verified the deletion of the petCBDA gene cluster encoding the catalytic components of the complex. Spectroscopic studies revealed that re-reduction of cytochrome c553 after flash-induced photo-oxidation was over 100 times slower in the ∆petCBDA mutant compared to the wild-type. Steady-state levels of oxidized P800 (the primary donor of the photochemical reaction center) were much higher in the ∆petCBDA mutant at every light level, consistent with a limitation in electron flow to the reaction center. The ∆petCBDA mutant was unable to grow phototrophically on acetate plus CO2 but could grow chemotrophically on pyruvate as a carbon source similar to the wild-type strain in the dark. The mutants could be complemented by reintroduction of the petCBDA gene cluster on a plasmid expressed from the clostridial eno promoter.