1,103 research outputs found
The acute effect of ābreaking-upā prolonged sitting on cardiovascular risk factors in overweight/obese adults
Session - Physical activity and cardiovascular disease in adults: paper no. 562This journal suppl. entitled: Be Avtive 2012INTRODUCTION: We have recently shown in a controlled laboratory setting that regularly ābreaking upā prolonged sitting with frequent short bouts of light-or moderate-intensity walking activity acutely lowers postprandial blood glucose and insulin concentrations. However, we are yet to report the effect of interrupting sitting time on secondary outcomes relating to cardiovascular disease. Consequently, we compared the effect of a single prolonged (7-hour) bout of sitting with a similar duration of sitting combined with intermittent bouts of light-intensity or moderate-intensity activity on blood pressure, blood lipids and CRP. METHODS: Overweight/obese adults (n=19; age range 45ā65 yrs) were recruited for a randomized three-week, three-treatment acute cross-over trial: 1) uninterrupted sitting; 2) seated with 2-minute bouts of light-intensity walking at 3.2 km/hr every 20 minutes; and 3) seated with 2-minute bouts of moderate-intensity walking at between 5.8ā6.4 km/hr every 20 minutes. Following the completion of baseline measurements and an initial 2 hour steady-state period, participants consumed a standard test meal (75 g glucose, 50 g fat). Serum triglycerides were assessed hourly to calculate the incremental area under the curve (iAUC) and high sensitivity C-reactive protein (hsCRP) was assessed at baseline and 7 hours. Seated brachial artery blood pressure was also measured every hour as a single measurement, 5 mins prior to each activity bout, with an automated oscillometric blood pressure monitor (Philips SureSigns VS3 Monitor). GEE models were adjusted for sex, age, BMI, fasting blood pressure and treatment order. RESULTS: Systolic blood pressure decreased similarly and significantly during the light and moderate-intensity activity conditions [light: 120Ā±4mmHg (hourly meanĀ±SEM), p=0.002; moderate: 120Ā±3mmHg, p=0.02] compared to uninterrupted sitting (125Ā±4mmHg). Diastolic blood pressure was also significantly reduced with both activity conditions (light: 78Ā±3mmHg, p=0.006; moderate: 78Ā±3mmHg, p=0.03) compared to uninterrupted sitting (79Ā±3mmHg). No significant group differences were observed in triglyceride iAUC, hsCRP and the hourly measurement of heart rate. DISCUSSION: These findings indicate that breaking up prolonged sitting with frequent short breaks of either light or moderate-intensity physical activity may have favourable effects on seated blood pressure. Further studies are needed to evaluate the chronic effects of breaking up sedentary time on cardiovascular disease risk factors and the feasibility of such strategies in the general community
Physical Activity/Exercise and Diabetes: A Position Statement of the American Diabetes Association
The adoption and maintenance of physical activity are critical foci for blood glucose management and overall health in individuals with diabetes and prediabetes. Recommendations and precautions vary depending on individual characteristics and health status. In this Position Statement, we provide a clinically oriented review and evidence-based recommendations regarding physical activity and exercise in people with type 1 diabetes, type 2 diabetes, gestational diabetes mellitus, and prediabetes. Physical activity includes all movement that increases energy use, whereas exercise is planned, structured physical activity. Exercise improves blood glucose control in type 2 diabetes, reduces cardiovascular risk factors, contributes to weight loss, and improves well-being (1,2). Regular exercise may prevent or delay type 2 diabetes development (3). Regular exercise also has considerable health benefits for people with type 1 diabetes (e.g., improved cardiovascular fitness, muscle strength, insulin sensitivity, etc.) (4). The challenges related to blood glucose management vary with diabetes type, activity type, and presence of diabetes-related complications (5,6). Physical activity and exercise recommendations, therefore, should be tailored to meet the specific needs of each individual
Theoretical investigations of a highly mismatched interface: the case of SiC/Si(001)
Using first principles, classical potentials, and elasticity theory, we
investigated the structure of a semiconductor/semiconductor interface with a
high lattice mismatch, SiC/Si(001). Among several tested possible
configurations, a heterostructure with (i) a misfit dislocation network pinned
at the interface and (ii) reconstructed dislocation cores with a carbon
substoichiometry is found to be the most stable one. The importance of the slab
approximation in first-principles calculations is discussed and estimated by
combining classical potential techniques and elasticity theory. For the most
stable configuration, an estimate of the interface energy is given. Finally,
the electronic structure is investigated and discussed in relation with the
dislocation array structure. Interface states, localized in the heterostructure
gap and located on dislocation cores, are identified
Explanation of the Colour Change in Alexandrites.
Alexandrites are remarkable and rare gemstones. They display an extraordinary colour change according to the ambient lighting, from emerald green in daylight to ruby red in incandescent light from tungsten lamps or candles. While this colour change has been correctly attributed to chromium impurities and their absorption band in the yellow region of the visible light spectrum, no adequate explanation of the mechanism has been given. Here, the alexandrite effect is fully explained by considering the von Kries model of the human colour constancy mechanism. This implies that our colour constancy mechanism is real (objective) and primarily attuned to correct for the colour temperature of black-body illuminants
Effects of dietary eicosapentaenoic acid on growth, survival, pigmentation and fatty acid composition in Senegal sole (Solea senegalensis) larvae during the Artemia feeding period
We examined the effect of dietary eicosapentaenoic acid (20:5n-3, EPA) on growth, survival, pigmentation and fatty acid composition of Senegal sole larvae using a dose-response design. From 3 to 40 days post hatch (dph), larvae were fed live food that had been enriched using one of four experimental emulsions containing graduated concentrations of EPA and constant docosahexaenoic acid (22:6n-3, DHA) and arachidonic acid (20:4n-6, ARA). Proportions of EPA in the enriched Artemia nauplii were described as ānilā (EPA-N, 0.5% total fatty acids, TFA), ālowā (EPA-L, 10.7% TFA), āmediumā (EPA-M, 20.3% TFA) or āhighā (EPA-H, 29.5% TFA). Significant differences among dietary treatments in larval length were observed at 25, 30 and 40 dph, and in dry weight at 30 and 40 dph, although no significant correlation could be found between dietary EPA content and growth. The stage of eye migration at 17 and 25 dph was significantly affected by dietary levels of EPA. Significantly lower survival was observed in fish fed EPA-H enriched nauplii. A significantly lower percentage of fish fed EPA-N (82.7%) and EPA-L (82.9%) diets were normally pigmented compared to the fish fed EPA-M (98.1%) and EPA-H (99.4%) enriched nauplii. Tissue fatty acid concentrations reflected the corresponding dietary composition. Arachidonic and docosahexaenoic acid levels in all the tissues examined were inversely related to dietary EPA. There was an increase in the proportion of docosapentaenoic acid (22:5n-3, DPA) in the tissues relative to the diet, which is indicative of chain elongation of EPA. This work concluded that Senegal sole larvae have a very low EPA requirement during the live feeding period
Courtship behavior, nesting microhabitat, and assortative mating in sympatric stickleback species pairs
Ā© 2021 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. The maintenance of reproductive isolation in the face of gene flow is a particularly contentious topic, but differences in reproductive behavior may provide the key to explaining this phenomenon. However, we do not yet fully understand how behavior contributes to maintaining species boundaries. How important are behavioral differences during reproduction? To what extent does assortative mating maintain reproductive isolation in recently diverged populations and how important are āmagic traitsā? Assortative mating can arise as a by-product of accumulated differences between divergent populations as well as an adaptive response to contact between those populations, but this is often overlooked. Here we address these questions using recently described species pairs of three-spined stickleback (Gasterosteus aculeatus), from two separate locations and a phenotypically intermediate allopatric population on the island of North Uist, Scottish Western Isles. We identified stark differences in the preferred nesting substrate and courtship behavior of species pair males. We showed that all males selectively court females of their own ecotype and all females prefer males of the same ecotype, regardless of whether they are from species pairs or allopatric populations. We also showed that mate choice does not appear to be driven by body size differences (a potential āmagic traitā). By explicitly comparing the strength of these mating preferences between species pairs and single-ecotype locations, we were able to show that present levels of assortative mating due to direct mate choice are likely a by-product of other adaptations between ecotypes, and not subject to obvious selection in species pairs. Our results suggest that ecological divergence in mating characteristics, particularly nesting microhabitat may be more important than direct mate choice in maintaining reproductive isolation in stickleback species pairs
Nonalbuminuric Renal Impairment in Type 2 Diabetic Patients and in the General Population (National Evaluation of the Frequency of Renal Impairment cO-existing with NIDDM [NEFRON] 11)
OBJECTIVE Most diabetic patients with impaired renal function have a urinary albumin excretion rate in the normal range. In these patients, the etiology of renal impairment is unclear, and it is also unclear whether this nonalbumunuric renal impairment is unique to diabetes. RESEARCH DESIGN AND METHODS In this study, we examined the frequency and predictors of nonalbumunuric renal impairment (estimated glomerular filtration rate [eGFR] <60 ml/min per 1.73 m(2)) in a nationally representative cohort of 3,893 patients with type 2 diabetes and compared our findings with rates observed in the general population from the Australian Diabetes, Obesity and Lifestyle Study (AusDiab) survey (n = 11,247). RESULTS Of the 23.1% of individuals with type 2 diabetes who had eGFR <60 ml/min per 1.73 m(2) (95% CI 21.8-24.5%), more than half (55%) had a urinary albumin excretion rate that was persistently in the normal range. This rate of renal impairment was predictably higher than that observed in the general population (adjusted odds ratio 1.3, 95% CI 1.1-1.5, P < 0.01) but was solely due to chronic kidney disease associated with albuminuria. In contrast, renal impairment in the absence of albuminuria was less common in those with diabetes than in the general population, independent of sex, ethnicity, and duration of diabetes (0.6, 0.5-0.7, P < 0.001). CONCLUSIONS Nonalbuminuric renal impairment is not more common in those with diabetes. However, its impact may be more significant. New studies are required to address the pathogenesis, prevention, and treatment of nonalbuminuric renal disease
No association between FCgammaR3B copy number variation and susceptibility to biopsy-proven giant cell arteritis
Objective. To determine the relationship between FCGR3B gene copy number variation (CNV) and biopsy proven giant cell arteritis (GCA). Methods. FCGR3B CNV was determined in 139 Australian biopsy proven GCA patients and 162 population matched controls, using a duplex qPCR assay and RNase P as the reference gene. Copy number was determined using Copy Caller software (v.1.0, Applied Biosystems, USA). CNV genotypes were classified into 3 groups (<2, 2, 3+) for analysis purposes, and analysis was performed using logistic regression. Results. All GCA patients had a positive temporal artery biopsy, and the most common presenting symptoms were visual disturbance and temporal headache. The mean age of patients at biopsy was 74 years (range 51-94) and 88/139 (63%) were female. The frequency of low (<2) FCGR3B copy number was comparable between GCA patients (9/139 = 6.5%) and controls (10/162 = 6.2%), as was the frequency of high (3+) FCGR3B copy number (15/130 (10.8%) in GCA patients versus 13/162 (8.0%) in controls). Overall there was no evidence that FCGR3B CNV frequencies differed between GCA patients and controls (Ļ (2) = 0.75, df = 2, P = 0.69). Conclusion. FCGR3B CNV is not associated with GCA; however, replicate studies are required.Emma Dunstan, Sue Lester, Rachel Black, Maureen Rischmueller, Helen Chan, Alex W. Hewitt, and Catherine L. Hil
Patient-related outcomes in patients referred to a respiratory clinic with persisting symptoms following non-hospitalised COVID-19
Survivors of COVID-19 can present with varied and persisting symptoms, regardless of hospitalisation. We describe the ongoing symptoms, quality of life and return to work status in a cohort of non-hospitalised COVID-19 survivors with persisting respiratory symptoms presenting to clinic, who consented and completed patient-reported outcome measures. We identified fatigue, reduced quality of life and dysregulated breathing alongside the breathlessness. Those with co-existent fatigue had worse mood and quality of life and were less likely to have returned to normal working arrangements compared to those without fatigue. For non-hospitalised people with persisting symptoms following COVID-19 referred to a respiratory assessment clinic, there was a need for a wider holistic assessment, including return to work strategies
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