THE EXTENT AND VALUE OF INFORMAL ECONOMIC ACTIVITY IN NON-METROPOLITAN WISCONSIN

Public Economics,

Step-based physical activity metrics and cardiometabolic risk: NHANES 2005-2006

Purpose: This study aimed to catalog the relationships between step-based accelerometer metrics indicative of physical activity volume (steps per day, adjusted to a pedometer scale), intensity (mean steps per minute from the highest, not necessarily consecutive, minutes in a day; peak 30-min cadence), and sedentary behavior (percent time at zero cadence relative to wear time; %TZC) and cardiometabolic risk factors. Methods: We analyzed data from 3388 participants, 20+ yr old, in the 2005-2006 National Health and Nutrition Examination Survey with >/=1 valid day of accelerometer data and at least some data on weight, body mass index, waist circumference, systolic and diastolic blood pressure, glucose, insulin, HDL cholesterol, triglycerides, and/or glycohemoglobin. Linear trends were evaluated for cardiometabolic variables, adjusted for age and race, across quintiles of steps per day, peak 30-min cadence, and %TZC. Results: Median steps per day ranged from 2247 to 12,334 steps per day for men and from 1755 to 9824 steps per day for women, and median peak 30-min cadence ranged from 48.1 to 96.0 steps per minute for men and from 40.8 to 96.2 steps per minute for women for the first and fifth quintiles, respectively. Linear trends were statistically significant (all P < 0.001), with increasing quintiles of steps per day and peak 30-min cadence inversely associated with waist circumference, weight, body mass index, and insulin for both men and women. Median %TZC ranged from 17.6% to 51.0% for men and from 19.9% to 47.6% for women for the first and fifth quintiles, respectively. Linear trends were statistically significant (all P < 0.05), with increasing quintiles of %TZC associated with increased waist circumference, weight and insulin for men, and insulin for women. Conclusions: This analysis identified strong linear relationships between step-based movement/nonmovement dimensions and cardiometabolic risk factors. These data offer a set of quantified access points for studying the potential dose-response effects of each of these dimensions separately or collectively in longitudinal observational or intervention study designs.Peer reviewedCommunity Health Sciences, Counseling and Counseling Psycholog

Hematopoietic Stem Cells Contribute to Lymphatic Endothelium

Although the lymphatic system arises as an extension of venous vessels in the embryo, little is known about the role of circulating progenitors in the maintenance or development of lymphatic endothelium. Here, we investigated whether hematopoietic stem cells (HSCs) have the potential to give rise to lymphatic endothelial cells (LEC). mice resulted in the incorporation of donor-derived LEC into the lymphatic vessels of spontaneously arising intestinal tumors.Our results indicate that HSCs can contribute to normal and tumor associated lymphatic endothelium. These findings suggest that the modification of HSCs may be a novel approach for targeting tumor metastasis and attenuating diseases of the lymphatic system

Cadence (steps/min) and intensity during ambulation in 6-20 year olds: The CADENCE-kids study

Background: Steps/day is widely utilized to estimate the total volume of ambulatory activity, but it does not directly reflect intensity, a central tenet of public health guidelines. Cadence (steps/min) represents an overlooked opportunity to describe the intensity of ambulatory activity. We sought to establish thresholds linking directly observed cadence with objectively measured intensity in 6-20 year olds.Methods: One hundred twenty participants completed multiple 5-min bouts on a treadmill, from 13.4 m/min (0.80 km/h) to 134.0 m/min (8.04 km/h). The protocol was terminated when participants naturally transitioned to running, or if they chose to not continue. Steps were visually counted and intensity was objectively measured using a portable metabolic system. Youth metabolic equivalents (METy) were calculated for 6-17 year olds, with moderate intensity defined as >/=4 and /=6 METy. Traditional METs were calculated for 18-20 year olds, with moderate intensity defined as >/=3 and /=6 METs. Optimal cadence thresholds for moderate and vigorous intensity were identified using segmented random coefficients models and receiver operating characteristic (ROC) curves.Result: Participants were on average (+/- SD) aged 13.1 +/- 4.3 years, weighed 55.8 +/- 22.3 kg, and had a BMI z-score of 0.58 +/- 1.21. Moderate intensity thresholds (from regression and ROC analyses) ranged from 128.4 steps/min among 6-8 year olds to 87.3 steps/min among 18-20 year olds. Comparable values for vigorous intensity ranged from 157.7 steps/min among 6-8 year olds to 119.3 steps/min among 18-20 year olds. Considering both regression and ROC approaches, heuristic cadence thresholds (i.e., evidence-based, practical, rounded) ranged from 125 to 90 steps/min for moderate intensity, and 155 to 125 steps/min for vigorous intensity, with higher cadences for younger age groups. Sensitivities and specificities for these heuristic thresholds ranged from 77.8 to 99.0%, indicating fair to excellent classification accuracy.Conclusions: These heuristic cadence thresholds may be used to prescribe physical activity intensity in public health recommendations. In the research and clinical context, these heuristic cadence thresholds have apparent value for accelerometer-based analytical approaches to determine the intensity of ambulatory activity.Peer reviewedCommunity Health Sciences, Counseling and Counseling Psycholog

Understanding the Local Unrecorded Economy: Informal Work and Home Production in Non-Metropolitan Wisconsin

Using a survey of 1,611 families in non-metropolitan Wisconsin, we assess the extent and importance of certain activities to make money, save money, or barter. Approximately 59% of families report involvement in the activities considered, with 122 median annual hours and median imputed value of $1368. Hours of such work are highly skewed. While some house-holds are extensively involved, most report only approximately 2-3 per week. Overall, while such work is common and some households engage in it extensively, substantial involvement in it appears too infrequent for it to serve as a major part of most households’ well-being

Additional file 2: of Cadence (steps/min) and intensity during ambulation in 6–20 year olds: the CADENCE-kids study

Table displaying final analytical data set in .xls format. (XLSX 115 kb

Additional file 1: of Cadence (steps/min) and intensity during ambulation in 6–20 year olds: the CADENCE-kids study

Table displaying miles/h and km/h conversions in .pdf format. (PDF 29 kb

Additional file 3: of Cadence (steps/min) and intensity during ambulation in 6–20 year olds: the CADENCE-kids study

Data dictionary in .xls format (XLSX 9 kb