Objective vs. Self-Reported Physical Activity and Sedentary Time: Effects of Measurement Method on Relationships with Risk Biomarkers

<p><b>Purpose:</b> Imprecise measurement of physical activity variables might attenuate estimates of the beneficial effects of activity on health-related outcomes. We aimed to compare the cardiometabolic risk factor dose-response relationships for physical activity and sedentary behaviour between accelerometer- and questionnaire-based activity measures.</p> <p><b>Methods:</b> Physical activity and sedentary behaviour were assessed in 317 adults by 7-day accelerometry and International Physical Activity Questionnaire (IPAQ). Fasting blood was taken to determine insulin, glucose, triglyceride and total, LDL and HDL cholesterol concentrations and homeostasis model-estimated insulin resistance (HOMAIR). Waist circumference, BMI, body fat percentage and blood pressure were also measured.</p> <p><b>Results:</b> For both accelerometer-derived sedentary time (<100 counts.min−1) and IPAQ-reported sitting time significant positive (negative for HDL cholesterol) relationships were observed with all measured risk factors – i.e. increased sedentary behaviour was associated with increased risk (all p≤0.01). However, for HOMAIR and insulin the regression coefficients were >50% lower for the IPAQ-reported compared to the accelerometer-derived measure (p<0.0001 for both interactions). The relationships for moderate-to-vigorous physical activity (MVPA) and risk factors were less strong than those observed for sedentary behaviours, but significant negative relationships were observed for both accelerometer and IPAQ MVPA measures with glucose, and insulin and HOMAIR values (all p<0.05). For accelerometer-derived MVPA only, additional negative relationships were seen with triglyceride, total cholesterol and LDL cholesterol concentrations, BMI, waist circumference and percentage body fat, and a positive relationship was evident with HDL cholesterol (p = 0.0002). Regression coefficients for HOMAIR, insulin and triglyceride were 43–50% lower for the IPAQ-reported compared to the accelerometer-derived MVPA measure (all p≤0.01).</p> <p><b>Conclusion:</b> Using the IPAQ to determine sitting time and MVPA reveals some, but not all, relationships between these activity measures and metabolic and vascular disease risk factors. Using this self-report method to quantify activity can therefore underestimate the strength of some relationships with risk factors.</p&gt

Introducing EMMIE: An evidence rating scale to encourage mixed-method crime prevention synthesis reviews

Objectives This short report describes the need for, and the development of, a coding system to distil the quality and coverage of systematic reviews of the evidence relating to crime prevention interventions. The starting point for the coding system concerns the evidence needs of policymakers and practitioners. Methods The coding scheme (EMMIE) proposed builds on previous scales that have been developed to assess the probity, coverage and utility of evidence both in health and criminal justice. It also draws on the principles of realist synthesis and review. Results The proposed EMMIE scale identifies five dimensions to which systematic reviews intended to inform crime prevention should speak. These are the Effect of intervention, the identification of the causal Mechanism(s) through which interventions are intended to work, the factors that Moderate their impact, the articulation of practical Implementation issues, and the Economic costs of intervention

A Simple Iterative Model Accurately Captures Complex Trapline Formation by Bumblebees Across Spatial Scales and Flower Arrangements

PMCID: PMC3591286This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Temporal and Individual Variation in Offspring Provisioning by Tree Swallows: A New Method of Automated Nest Attendance Monitoring

Studies of the ecology and evolution of avian nesting behavior have been limited by the difficulty and expense of sampling nest attendance behavior across entire days or throughout a substantial portion of the nestling period. Direct observation of nesting birds using human observers and most automated devices requires sub-sampling of the nestling period, which does not allow for the quantification of the duration of chick-feeding by parents within a day, and may also inadequately capture temporal variation in the rate at which chicks are fed. Here I describe an inexpensive device, the Automated Perch Recorder (APR) system, which collects accurate, long-term data on hourly rates of nest visitation, the duration of a pair's workday, and the total number of visits the pair makes to their nest across the entire period for which it is deployed. I also describe methods for verifying the accuracy of the system in the field, and several examples of how these data can be used to explore the causes of variation in and tradeoffs between the rate at which birds feed their chicks and the total length of time birds spend feeding chicks in a day

Plasma protein C levels in immunocompromised septic patients are significantly lower than immunocompetent septic patients: a prospective cohort study

Introduction: Activated Protein C [APC] improves outcome in immunocompetent patients with severe sepsis particularly in those who are perceived to have high mortality risk. Before embarking on a trial of APC administration in immunocompromised septic patients, a preliminary study on plasma levels of protein C in this cohort is essential

Insulin Resistance in Chileans of European and Indigenous Descent: Evidence for an Ethnicity x Environment Interaction

<p><b>Background:</b> Effects of urbanisation on diabetes risk appear to be greater in indigenous populations worldwide than in populations of European origin, but the reasons are unclear. This cross-sectional study aimed to determine whether the effects of environment (Rural vs. Urban), adiposity, fitness and lifestyle variables on insulin resistance differed between individuals of indigenous Mapuche origin compared to those of European origin in Chile.</p> <p><b>Methodology/Principal Findings:</b> 123 Rural Mapuche, 124 Urban Mapuche, 91 Rural European and 134 Urban European Chilean adults had blood taken for determination of HOMA-estimated insulin resistance (HOMA(IR)) and underwent assessment of physical activity/sedentary behaviour (using accelerometry), cardiorespiratory fitness, dietary intake and body composition. General linear models were used to determine interactions with ethnicity for key variables. There was a significant "ethnicity x environment" interaction for HOMA(IR) (Mean +/- SD; Rural Mapuche: 1.65 +/- 2.03, Urban Mapuche: 4.90 +/- 3.05, Rural European: 0.82 +/- 0.61, Urban European: 1.55 +/- 1.34, p((interaction)) = 0.0003), such that the effect of urbanisation on HOMA(IR) was greater in Mapuches than Europeans. In addition, there were significant interactions (all p<0.004) with ethnicity for effects of adiposity, sedentary time and physical activity on HOMA(IR), with greater effects seen in Mapuches compared to Europeans, an observation that persisted after adjustment for potential confounders.</p> <p><b>Conclusions/Significance:</b> Urbanisation, adiposity, physical activity and sedentary behaviour influence insulin resistance to a greater extent in Chilean Mapuches than Chileans of European descent. These findings have implications for the design and implementation of lifestyle strategies to reduce metabolic risk in different ethnic groups, and for understanding of the mechanisms underpinning human insulin resistance.</p&gt

Differential effects of natural palm oil, chemically- and enzymatically-modified palm oil on weight gain, blood lipid metabolites and fat deposition in a pediatric pig model

<p>Abstract</p> <p>Background</p> <p>Increasing prevalence of obesity and overweight in the Western world, continue to be a major health threat and is responsible for increased health care costs. Dietary intervention studies show a strong positive association between saturated fat intake and the development of obesity and cardiovascular disease. This study investigated the effect of positional distribution of palmitic acid (Sn-1, 2 & 3) of palm oil on cardiovascular health and development of obesity, using weaner pigs as a model for young children.</p> <p>Methods</p> <p>Male and female weaner piglets were randomly allocated to 4 dietary treatment groups: 1) pork lard (LRD); 2) natural palm olein (NPO); 3) chemically inter-esterified PO (CPO) and 4) enzymatically inter-esterified PO (EnPO) as the fat source. Diets were formulated with 11% lard or with palm olein in order to provide 31% of digestible energy from fat in the diet and were balanced for cholesterol, protein and energy across treatments.</p> <p>Results</p> <p>From 8 weeks onwards, pigs on EnPO diet gained (P < 0.05) more weight than all other groups. Feed conversion efficiency (feed to gain) over the 12 week experimental period did not vary between treatment groups. Plasma LDL-C content and LDL-C/HDL-C ratio in pigs fed natural PO tended to be lower compared to all other diets. The natural PO lowered (P < 0.02) the plasma triglyceride (TG) content relative to the lard or EnPO diets, but was not different from the CPO diet. The natural PO diet was associated with lower (P < 0.05) saturated fat levels in subcutaneous adipose tissue than the CPO and EnPO diets that had lower saturated fat levels than the lard diet. Female pigs had lower lean and higher fat and fat:lean ratio in the body compared with male pigs. No difference in weight gain or blood lipid parameters was observed between sexes.</p> <p>Conclusions</p> <p>The observations on plasma TG, muscle and adipose tissue saturated fatty acid contents and back fat (subcutaneous) thickness suggest that natural palm oil may reduce deposition of body fat. In addition, dietary supplementation with natural palm oil containing palmitic acid at different positions in meat producing animals may lead to the production of meat and meat products with lower saturated fats. An increase in fat content and a decrease in lean content in female pigs resulted in an increased body fat:lean ratio but gender had no effect on blood lipid parameters or insulin concentrations.</p

The Murid Herpesvirus-4 gH/gL Binds to Glycosaminoglycans

The first contact a virus makes with cells is an important determinant of its tropism. Murid Herpesvirus-4 (MuHV-4) is highly dependent on glycosaminoglycans (GAGs) for cell binding. Its first contact is therefore likely to involve a GAG-binding virion glycoprotein. We have previously identified two such proteins, gp70 and gp150. Gp70 binds strongly to GAGs. However, deleting it makes little difference to MuHV-4 cell binding or GAG-dependence. Deleting gp150, by contrast, frees MuHV-4 from GAG dependence. This implies that GAGs normally displace gp150 to allow GAG-independent cell binding. But the gp150 GAG interaction is weak, and so would seem unlikely to make an effective first contact. Since neither gp70 nor gp150 matches the expected profile of a first contact glycoprotein, our understanding of MuHV-4 GAG interactions must be incomplete. Here we relate the seemingly disconnected gp70 and gp150 GAG interactions by showing that the MuHV-4 gH/gL also binds to GAGs. gH/gL-blocking and gp70-blocking antibodies individually had little effect on cell binding, but together were strongly inhibitory. Thus, there was redundancy in GAG binding between gp70 and gH/gL. Gp150-deficient MuHV-4 largely resisted blocks to gp70 and gH/gL binding, consistent with its GAG independence. The failure of wild-type MuHV-4 to do the same argues that gp150 is normally engaged only down-stream of gp70 or gH/gL. MuHV-4 GAG dependence is consequently two-fold: gp70 or gH/gL binding provides virions with a vital first foothold, and gp150 is then engaged to reveal GAG-independent binding

English Language Proficiency and Geographical Proximity to a Safety Net Clinic as a Predictor of Health Care Access

Studies suggest that proximity to a safety net clinic (SNC) promotes access to care among the uninsured. Distance-based barriers to care may be greater for people with limited English proficiency (LEP), compared to those who are English proficient (EP), but this has not been explored. We assessed the relationship between distance to the nearest SNC and access in non-rural uninsured adults in California, and examined whether this relationship differs by language proficiency. Using the 2005 California Health Interview Survey and a list we compiled of California’s SNCs, we calculated distance between uninsured interviewee residence and the exact address of the nearest SNC. Using multivariate regression to adjust for other relevant characteristics, we examined associations between this distance and interviewee’s probability of having a usual source of health care (USOC) and having visited a physician in the prior 12 months. To examine differences by language proficiency, we included interactions between distance and language proficiency. Uninsured LEP adults living within 2 miles of a SNC were 9.3% less likely than their EP counterparts to have a USOC (P = 0.046). Further, distance to the nearest SNC was inversely associated with the probability of having a USOC among LEP, but not among EP; consequently, the difference between LEP and EP in the probability of having a USOC widened with increasing distance to the nearest SNC. There was no difference between LEP and EP adults living within 2 miles of a SNC in likelihood of having a physician visit; however, as with USOC, distance to the nearest SNC was inversely associated with the probability of having a physician visit among LEP but not EP. The effect sizes diminished, but remained significant, when we included county fixed effects in the models. Having LEP is a barrier to health care access, which compounds when combined with increased distance to the nearest SNC, among uninsured adults. Future studies should explore potential mechanisms so that appropriate interventions can be implemented

Effect of root age on the biomechanics of seminal and nodal roots of barley (<i>Hordeum vulgare L.</i>) in contrasting soil environments

Acknowledgments The James Hutton Institute receives funding from the Scottish Government. The authors would also like to thank Jim McNicol from Biomathematics and Statistics Scotland for his advice on statistical analysis.Peer reviewedPostprin