Associations of recreational and non-recreational physical activity with coronary artery calcium density vs. volume and cardiovascular disease events: the Multi-Ethnic Study of Atherosclerosis.

AimsThe benefits of physical activity (PA) on cardiovascular disease (CVD) are well known. However, studies suggest PA is associated with coronary artery calcium (CAC), a subclinical marker of CVD. In this study, we evaluated the associations of self-reported recreational and non-recreational PA with CAC composition and incident CVD events. Prior studies suggest high CAC density may be protective for CVD events.Methods and resultsWe evaluated 3393 participants of the Multi-Ethnic Study of Atherosclerosis with prevalent CAC. After adjusting for demographics, the highest quintile of recreational PA was associated with 0.07 (95% confidence interval 0.01-0.13) units greater CAC density but was not associated with CAC volume. In contrast, the highest quintile of non-recreational PA was associated with 0.08 (0.02-0.14) units lower CAC density and a trend toward 0.13 (-0.01 to 0.27) log-units higher CAC volume. There were 520 CVD events over a 13.7-year median follow-up. Recreational PA was associated with lower CVD risk (hazard ratio 0.88, 0.79-0.98, per standard deviation), with an effect size that was not changed with adjustment for CAC composition or across levels of prevalent CAC.ConclusionRecreational PA may be associated with a higher density but not a higher volume of CAC. Non-recreational PA may be associated with lower CAC density, suggesting these forms of PA may not have equivalent associations with this subclinical marker of CVD. While PA may affect the composition of CAC, the associations of PA with CVD risk appear to be independent of CAC

Former teachers’ perceptions of post-teaching career job satisfaction : lessons for the profession

Teachers worldwide are rethinking their commitment to the profession and their traditional roles in schools and classroom teaching, evidenced by significant global rates of teacher attrition and subsequent teacher shortages. Research aimed at deepening our understanding of teachers’ decisions to leave the profession has primarily reported on teachers’ intentions to leave the profession, with limited insights from former teachers. In this paper, we report on the second phase of a national study in Australia that focused on understanding teacher attrition from the perspectives of former teachers and their post-teaching work experiences. Framed by the concept of work satisfaction, we draw on in-depth interviews with 25 former teachers from across the country to understand the motivating factors shaping their post-teaching work experiences. Using thematic analysis, the findings revealed the power of professional autonomy, trust, and care as enablers of work satisfaction. These findings have the potential to identify the necessary changes at the individual, school, and systemic levels that would encourage a return to teaching in schools and strategies aimed at enhancing retention. © 2025 Educational Review

‘I left the teaching profession … and this is what I am doing now’: a national study of teacher attrition

Current teacher attrition in Australia and globally has created an untenable situation for many schools, teachers and the profession. This paper reports on research that examined the critical issue of teacher attrition from the perspective of former classroom teachers and school leaders. Although there is extensive national and global research related to teacher shortages and intentions to leave the teaching profession, minimal research has sought insights from those who have left the profession in Australia, including ascertaining what they are doing now. Using an online survey, data were collected from 256 former teachers from all states and territories, sectors and career stages who had left the profession between 2016 and 2022. Using descriptive statistical and thematic analysis, this study highlights the potential loss to teaching and the education profession more broadly due to teacher attrition. For these participants, the reasons for leaving were often multifaceted and the process of leaving was often protracted. Many of these former teachers have maintained links to the education profession occupying various associated roles and positions. We call for a reconsideration of the ways that strategies to ameliorate teacher attrition are conceptualised and implemented. © The Author(s) 2024

Sitting Less and Moving More: Implications for Hypertension.

Through a hypertension lens, this review focuses on the serious health implications and potential counter-measures for the high volumes of uninterrupted sitting that characterises modern lifestyles. Reducing and breaking up sitting may represent a viable clinical and population health strategy to reduce blood pressure and related cardiovascular risk factors, which in contrast to moderate-vigorous physical activity, may have significant potential for widespread uptake. This review synthesises findings on the specific relationships of sedentary behaviour with BP - which primarily are from observational and acute experimental studies - including a discussion on the relevant cardiovascular mechanisms. It also considers what will need to be better understood as a basis for evidence-based recommendations on sedentary time in the context of BP control, and identify evidence gaps for future research

Diel surface temperature range scales with lake size

Ecological and biogeochemical processes in lakes are strongly dependent upon water temperature. Long-term surface warming of many lakes is unequivocal, but little is known about the comparative magnitude of temperature variation at diel timescales, due to a lack of appropriately resolved data. Here we quantify the pattern and magnitude of diel temperature variability of surface waters using high-frequency data from 100 lakes. We show that the near-surface diel temperature range can be substantial in summer relative to long-term change and, for lakes smaller than 3 km2, increases sharply and predictably with decreasing lake area. Most small lakes included in this study experience average summer diel ranges in their near-surface temperatures of between 4 and 7°C. Large diel temperature fluctuations in the majority of lakes undoubtedly influence their structure, function and role in biogeochemical cycles, but the full implications remain largely unexplored

The Development of Facial Bristles in Tawny Frogmouths (Podargus strigoides)

Facial bristles are present in many avian species, although their morphology and function are still not well understood. Previous studies have suggested that rictal bristles are tactile and may play a role in nocturnal foraging, although how they develop and are used is unclear. We study here the facial bristles of the tawny frogmouth (Podargus strigoides). We describe the development of rictal bristles, alongside other developmental milestones, such as plumage and eye-opening. We note four clear stages of plumage and eye-opening and three stages of rictal bristle emergence. Chicks were born without facial bristles, and rictal bristles emerged after the eyes matured. They were fully developed only after the chick had fledged and engaged in independent feeding. This supports the suggestion that rictal bristles may play a role in independent foraging and feeding

The evolutionary origin of avian facial bristles and the likely role of rictal bristles in feeding ecology

Facial bristles are one of the least described feather types and have not yet been systematically studied across phylogenetically diverse avian species. Consequently, little is known about their form, function and evolutionary history. Here we address this knowledge gap by characterising the evolution of facial bristles for the first time. We especially focus on rictal bristle presence and their associations with foraging behaviour, diet and habitat preferences in 1022 avian species, representing 91 families in 29 orders. Results reveal that upper rictal, lower rictal and interramal bristles were likely to be present in the most recent common ancestor of this avian phylogeny, whereas narial bristles were likely to be absent. Rictal bristle presence, length and shape varied both within and between avian orders, families and genera. Rictal bristles were gained or lost multiple times throughout evolution, which suggest that the different morphologies observed within species might not be homologous. Phylogenetic relatedness is also not likely to be the only driver of rictal bristle presence and morphology. Rictal bristle presence and length were associated with species-specific ecological traits, especially nocturnality. Our findings suggest that species foraging in low-light conditions are likely to have longer rictal bristles, and that rictal bristles are likely to have evolved in early birds

Benefits for Type 2 Diabetes of Interrupting Prolonged Sitting With Brief Bouts of Light Walking or Simple Resistance Activities

OBJECTIVE To determine whether interrupting prolonged sitting with brief bouts of light-intensity walking (LW) or simple resistance activities (SRA) improves postprandial cardiometabolic risk markers in adults with type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS In a randomized crossover trial, 24 inactive overweight/obese adults with T2D (14 men 62 ± 6 years old) underwent the following 8-h conditions on three separate days (with 6–14 days washout): uninterrupted sitting (control) (SIT), sitting plus 3-min bouts of LW (3.2 km · h−1) every 30 min, and sitting plus 3-min bouts of SRA (half-squats, calf raises, gluteal contractions, and knee raises) every 30 min. Standardized meals were consumed during each condition. Incremental areas under the curve (iAUCs) for glucose, insulin, C-peptide, and triglycerides were compared between conditions. RESULTS Compared with SIT, both activity-break conditions significantly attenuated iAUCs for glucose (SIT mean 24.2 mmol · h · L−1 [95% CI 20.4–28.0] vs. LW 14.8 [11.0–18.6] and SRA 14.7 [10.9–18.5]), insulin (SIT 3,293 pmol · h · L−1 [2,887–3,700] vs. LW 2,104 [1,696–2,511] and SRA 2,066 [1,660–2,473]), and C-peptide (SIT 15,641 pmol · h · L−1 [14,353–16,929] vs. LW 11,504 [10,209–12,799] and SRA 11,012 [9,723–12,301]) (all P < 0.001). The iAUC for triglycerides was significantly attenuated for SRA (P < 0.001) but not for LW (SIT 4.8 mmol · h · L−1 [3.6–6.0] vs. LW 4.0 [2.8–5.1] and SRA 2.9 [1.7–4.1]). CONCLUSIONS Interrupting prolonged sitting with brief bouts of LW or SRA attenuates acute postprandial glucose, insulin, C-peptide, and triglyceride responses in adults with T2D. With poor adherence to structured exercise, this approach is potentially beneficial and practical

Acute effects of breaking up prolonged sitting on fatigue and cognition: a pilot study.

OBJECTIVES: To compare the acute effects of uninterrupted sitting with sitting interrupted by brief bouts of light-intensity walking on self-reported fatigue, cognition, neuroendocrine biomarkers and cardiometabolic risk markers in overweight/obese adults. DESIGN: Randomised two-condition crossover trial. SETTING: Laboratory study conducted in Melbourne, Australia. PARTICIPANTS: 19 overweight/obese adults (45-75 years). INTERVENTIONS: After an initial 2 h period seated, participants consumed a meal-replacement beverage and completed (on 2 days separated by a 6-day washout period) each condition over the next 5 h: uninterrupted sitting (sedentary condition) or sitting with 3 min bouts of light-intensity walking every 30 min (active condition). PRIMARY OUTCOME MEASURES: Self-reported fatigue, executive function and episodic memory at 0 h, 4 h and 7 h. SECONDARY OUTCOME MEASURES: Neuroendocrine biomarkers and cardiometabolic risk markers (blood collections at 0 h, 4 h and 7 h, blood pressure and heart rate measured hourly and interstitial glucose measured using a continuous glucose monitoring system). RESULTS: During the active condition, fatigue levels were lower at 4 h (-13.32 (95% CI -23.48 to -3.16)) and at 7 h (-10.73 (95% CI -20.89 to -0.58)) compared to the sedentary condition. Heart rate was higher at 4 h (4.47 (95% CI 8.37 to 0.58)) and at 7 h (4.32 (95% CI 8.21 to 0.42)) during the active condition compared to the sedentary condition. There were no significant differences between conditions by time for other variables. In the sedentary condition, changes in fatigue scores over time correlated with a decrease in heart rate and plasma dihydroxyphenylalanine (DOPA) and an increase in plasma dihydroxyphenylglycol (DHPG). CONCLUSIONS: Interrupting prolonged sitting with light-intensity walking breaks may be an effective fatigue countermeasure acutely. Fatigue levels corresponded with the heart rate and neuroendocrine biomarker changes in uninterrupted sitting in this pilot study. Further research is needed to identify potential implications, particularly for the occupational health context. TRIAL REGISTRATION NUMBER: ACTRN12613000137796; Results

Interrupting prolonged sitting with brief bouts of light walking or simple resistance activities reduces resting blood pressure and plasma noradrenaline in type 2 diabetes.

OBJECTIVE: Prolonged sitting is increasingly recognized as a ubiquitous cardiometabolic risk factor, possibly distinct from lack of physical exercise. We examined whether interrupting prolonged sitting with brief bouts of light-intensity activity reduced blood pressure (BP) and plasma noradrenaline in type 2 diabetes (T2D). METHODS: In a randomized crossover trial, 24 inactive overweight/obese adults with T2D (14 men; mean ± SD; 62 ± 6 years) consumed standardized meals during 3 × 8 h conditions: uninterrupted sitting (SIT); sitting + half-hourly bouts of walking (3.2 km/h for 3-min) (light-intensity walking); and sitting + half-hourly bouts of simple resistance activities for 3 min (SRAs), each separated by 6-14 days washout. Resting seated BP was measured hourly (mean of three recordings, ≥20-min postactivity). Plasma noradrenaline was measured at 30-min intervals for the first hour after meals and hourly thereafter. RESULTS: Compared with SIT, mean resting SBP and DBP were significantly reduced (P < 0.001) for both light-intensity walking (mean ± SEM; -14 ± 1/-8 ± 1 mmHg) and SRA (-16 ± 1/-10 ± 1 mmHg), with a more pronounced effect for SRA (P < 0.05 versus light-intensity walking). Similarly, mean plasma noradrenaline was significantly reduced for both light-intensity walking (-0.3 ± 0.1 nmol/l) and SRA (-0.6 ± 0.1 nmol/l) versus SIT, with SRA lower than light-intensity walking (P < 0.05). Mean resting heart rate was lowered by light-intensity walking (-3 ± 1 bpm; P < 0.05), but not SRA (-1 ± 1 bpm). CONCLUSION: Interrupting prolonged sitting with brief bouts of light-intensity walking or SRA reduces resting BP and plasma noradrenaline in adults with T2D, with SRA being more effective. Given the ubiquity of sedentary behaviors and poor adherence to structured exercise, this approach may have important implications for BP management in patients with T2D