Compliance contribution of a crack surrounded by microdefects: Is modeling of their effect by a homogenized material legitimate?

On computation of the compliance and stiffness contribution tensors of non ellipsoidal inhomogeneities

The problem of overnutrition and obesity tend to increase year by. Office employee are susceptible to physical inactivity and obesity. In context of current pandemic, exercising via online media, termed ‘tele-exercise’ may be an effective alternative intervention. However, the effect of compliance and timing of exercise on overall health-related output are still not often discussed. The purpose of the study is to compare the effect of tele-exercise done during working hours vs. after working hours on obese office employee’s weight loss and improvement of body fat percentage, as well as their relation to compliance level. The design of this study is quasi-experimental design, with obese office employee as participants, which then grouped into after work exercise (AW, n = 36, 1-hour duration) and mid-work exercise (DW, n = 21, 30-minute duration). Total sampling was used since the target population were under 100 people. Exercises were done 3 times/week for 12 weeks. Data collected were sample characteristics, bodyweight, and percentage of body fat. Both timing of intervention is effective on reducing body weight significantly (p<0.05). Significant reduction (p<0.05) on percentage of body fat is only occurring in DW group. Compliance level for AW and DW group are 63.75% and 61.23%, respectively, and being insignificant to each other (p>0.05). The contribution of compliance in shorter exercise/DW on body fat loss and weight loss is 23.1% and 20.9%, respectively; while the contribution of compliance in longer exercise/AW is 11.3% on body weight loss. A short, mid-working exercise have the similar or even better effect than 1-hour after-work exercise session on weight loss and body fat loss. We recommend tele-exercising during working hours for at least 30 minutes to achieve significant body weight and body fat loss.

Effective arterial elastance (Ea), an index of arterial load, increases with elevations in left ventricular elastance to maximize the efficiency of left ventricular stroke work during exercise. The arterial load is comprised of both systemic arterial compliance (C) and systemic vascular resistance (R)-to-cardiac cycle length (T) ratio (R/T) and is regulated by a reciprocal combination between C and R. Under resting condition, the relative contribution of 1/C to Ea is less than R/T (approximately one-third that of R/T). However, the contributions of C and R to Ea during exercise remain unclear. R markedly decreases during exercise, but Ea increases. We hypothesized that C during exercise (conditions of increased arterial load) becomes the predominant factor determining Ea. PURPOSE: This study was aimed to clarify whether the contribution of C to Ea increases during exercise to maintain a balance with left ventricular elastance, and this phenomenon is altered by different exercise intensity. METHODS: Ea (0.9 × systolic blood pressure/stroke volume), C (stroke volume/pulse pressure), R (mean blood pressure/cardiac output), and T were measured at rest and during exercise of 40, 60, and 80% maximal oxygen uptake (VO2max) using Doppler echocardiography and sphygmomanometry in 45 healthy young men. RESULTS: Ea did not differ between rest and 40%VO2max, but it was significantly greater at 60% and 80%VO max. 1/C significantly increased during exercise in an exercise intensity-dependent manner, whereas R/T significantly decreased at 40%VO2max and gradually increased at 60% and 80%VO2max. These results suggest that, under conditions of increased exertion, 1/C contributes to changes in Ea than R/T. Additionally, we performed multiple linear regression analysis to confirm relative contributions of C and R to Ea. Ea was highly related to 1 /C and R/T at all conditions (all r2=1.00). The contribution (the standardized regression coefficient) of 1/C to Ea at rest was lower than R/T, but this contribution elevated with increasing exercise intensity (Ratio of 1/C to R/T: rest, 0.45 vs. 40%VO2max, 0.64; 60%VO2max, 0.96; 80%VO2max, 0.89). CONCLUSION: This study demonstrated that the contribution of systemic arterial compliance to effective arterial elastance increases during exercise, and the peak contribution was observed at moderate exercise intensity (60%VO max). Therefore, we propose that the increased contribution of systemic arterial compliance to effective arterial elastance may participate in the regulation of the arterial load during exercise. Supported by grants from the Ministry of Education, Culture, Sports, Science and Technology of Japan (17700486).

Abstract

Compliance and resistivity contribution tensors of axisymmetric concave pores

Effective arterial elastance (Ea), an index of arterial load, increases with elevations in left ventricular elastance to maximize the efficiency of left ventricular stroke work during exercise. Systemic arterial compliance (C) and vascular resistance (R) are the primary components contributing to Ea, and R plays a greater role in determining Ea at rest. We hypothesized that the contribution of C to Ea increases during exercise to maintain an optimal balance between arterial load and ventricular elastance, and that the increase in Ea is due primarily to a reduction in C. The aim of this study was to investigate the contributions of C and R to Ea during exercise. Ea (0.9 x systolic blood pressure/stroke volume), C (stroke volume/pulse pressure), R (mean blood pressure/cardiac output), and cardiac cycle length (T) were measured at rest and during exercise of 40%, 60% and 80% maximal oxygen uptake (O(2max)) using Doppler echocardiography in 45 healthy men. Ea did not differ between rest and 40%O(2max), but it was greater at 60% and 80%O(2max). C markedly decreased during exercise in an exercise intensity-dependent manner. The changes in R/T during exercise were small, whereas it decreased at 40%O(2max) and gradually increased at 60% and 80%O(2max). The present results suggest that the contribution of systemic arterial compliance to effective arterial elastance increases during exercise. Therefore, we propose that the increase in arterial load during exercise is mainly driven by a reduction in systemic arterial compliance.

Biped robot design powered by antagonistic pneumatic actuators for multi-modal locomotion

The respective contribution of systemic vascular resistance (R) and total arterial compliance (C) to the arterial load remains to be established in humans. Effective arterial elastance (Ea), i.e., the left ventricular end-systolic pressure (LVESP)-over-stroke volume ratio, is a reliable estimate of arterial load. It is widely accepted that Ea mainly relates to mean aortic pressure (MAP) and thus to the R-to-T ratio (R/T ratio), where T is cycle length. We tested the contribution of R/T and 1/C to Ea in 20 normotensive and 46 hypertensive subjects (MAP range: 84-160 mmHg). The multilinear model applied (Ea = 1.00R/T + 0.42/C - 0.04; r2 = 0.97). The sensitivity of Ea to a change in R/T was 2.5 times higher than to a similar change in 1/C in both normotensive and hypertensive adults. The LVESP was more strongly related to systolic aortic pressure (SAP; r2 = 0.94) than to MAP (r2 = 0.83), and LVESP matched 90% SAP (bias = 0 +/- 5mmHg). An alternative model of Ea is proposed, in which Ea is proportional to the heart rate x SAP product-over-cardiac index ratio whatever the MAP.

This study estimated compliance with American Academy of Pediatrics (AAP) guidelines for well-child care and the association between compliance and age at diagnosis in a national sample of Medicaid-enrolled children with autism (N=1,475). Mixed effects linear regression was used to assess the relationship between compliance and age at diagnosis. Mean age at diagnosis was 37.4 (SD 8.4) months, and mean compliance was 55% (SD 33%). Children whose care was compliant with AAP guidelines were diagnosed 1.6months earlier than children who received no well-child care. Findings support that the timely receipt of well-child care may contribute to earlier detection. Additional research on the contribution of compliance, well-child visit components and provider characteristics on the timely diagnosis of autism is needed.

To determine the importance and contribution of compliance in a pelvic muscle exercise program as a factor in reducing the severity of urinary stress incontinence amongst Chinese women. Two hundred fourteen women presenting with urinary stress incontinence who agreed to undertake a program of pelvic muscle exercises were recruited into the study. Incontinence (wetting episodes), pelvic muscle strength, exercises compliance, correctness of pelvic muscle exercise technique, duration of stress incontinence, and previous history of pelvic surgery were recorded on four occasions: baseline (first clinic session) and second to fourth clinic sessions. Demographic data were also collected at baseline. Stepwise multiple regression analyses were used to determine the relative importance of compliance to exercise regime in predicting the severity of incontinence. Path analysis was used to provide a summary description of the influence of compliance on the outcomes over the four visits. The pelvic muscle training program appears to be able to reduce the overall urinary incontinence episodes by 85.2% and achieved a 73.1% increase in pelvic muscle strength. Although the number of wetting episodes in any visit are causally linked to that recorded in previous visit, those who were more compliant had a greater reduction. Age, mode of delivery, menopausal status, history of pelvic surgery, and duration of incontinence did not appear to contribute significantly to predicting incontinence. Compliance with pelvic muscle exercises significantly contributed to a reduction in urinary stress incontinence.

Nonulcer Dyspepsia: A Look Into the Future

Being tax compliant generates costs and these costs affect small business tax compliance behaviour and contribution. This study uses multiple regression analyses to investigate the key drivers of small business’s internal tax compliance costs (hours spent internally on tax compliance activities). This will assist Revenue Services in understanding what factors (determinants) could increase a small business’s internal tax compliance costs and might assist in managing tax compliance behaviour and contribution. The results expose the significant determinants per tax type, enabling a comparison to be made across the different tax types. Overall, turnover is the variable that had the most significant influence on internal tax compliance costs (time) (as opposed to the number of employees, which had a significant effect only on the internal time spent on employees’ tax). The analysis confirmed that there is a higher proportional burden for smaller businesses in respect of internal income tax and employees’ compliance activities.

A unified methodology for calculation of compliance and stiffness contribution tensors of inhomogeneities of arbitrary 2D and 3D shapes embedded in isotropic matrix – open access software.

Increasingly tighter enforcement of environmental and worker health and safety regulations is underlined with compliance a necessary way of life, resulting benefits are identified The contributions to improvements in production and cost savings are listed.

A circular hole with two symmetric rectilinear radial cracks initiated at its boundary is analyzed from the point of view of its elastic compliance (contribution to the overall elastic properties of a representative volume). Results are obtained using Rice’s connection between stress intensity factor and effect of a crack on the elastic properties of a material. We compare our result with that for a combine contribution of noninteracting circular pore and a rectilinear crack to show when this combination can be used for approximation of the elastic compliance contribution.