A Standardized Protocol for Measuring Bioelectrical Impedance in Green Turtles (Chelonia mydas).

AbstractBioelectrical impedance analysis (BIA) is gaining popularity in wildlife studies as a portable technology for immediate and nondestructive predictions of body composition components, such as fat-free and fat masses. Successful application of BIA for field-based research requires the identification and control of potential sources of error, as well as the creation of and adherence to a standardized protocol for measurement. The aim of our study was to determine sources of error and to provide a standardization protocol to improve measurement precision of BIA on juvenile green turtles (Chelonia mydas; n=35). We assessed the effects of altered environmental temperature (20°C-30°C), postprandial state (2-72 h), and time out of the water (2 h) on five impedance parameters (resistance at infinite frequency [Rinf], resistance at zero frequency [R0], resistance at 50 kHz [R50], phase angle at 50 kHz [PhA50], and intracellular resistance [Ri]) using a bioimpedance spectroscopy device. Technical reproducibility of measurements and interanimal variability were also assessed. We found an inverse exponential relationship between change in environmental temperature and impedance parameters Rinf, R0, and R50. Postprandial state significantly increased Rinf and Ri 72 h after feeding. BIA measurements were reproducible within individual juvenile green turtles at temperatures from 20°C to 30°C. Significant variation in impedance values was found between animals at all temperatures, sampling times, and postprandial states, but the relative differences (%) were small in magnitude. Our study suggests that measurement precision is improved by measuring animals at consistent environmental temperatures close to their preferred thermal range. We propose a standardized protocol of measurement conditions to facilitate laboratory and field use of BIA for body composition assessment studies in turtles.

Efficacy of a brief web-based intervention with and without SMS to enhance healthy eating behaviors among university students.

BACKGROUND: Healthy eating, such as the regular inclusion of fruits and vegetables in one's diet, is essential for maintaining optimal weight, maximizing brain and immune system functioning, and reducing the risk for disease. Despite its importance, few students meet recommended guidelines for healthy dietary behavior. The current study was designed to test the efficacy of two ehealth intervention approaches for increasing healthy eating behaviors among university students. METHODS: Student volunteers from an introductory psychology class at a northeastern US university participated for class credit (n=154). Students were randomized to either an assessment only (AO), web-based nutrition intervention only (WBO), or web-intervention with daily text-messaging condition (WB+M). Participants completed measures of vegetable and fruit consumption and frequency of meals with designated healthy food selections at baseline and one-month follow-up. RESULTS: Only the WB+M intervention significantly increased the likelihood of attaining vegetable consumption standards and increased the frequency of designated healthy food choice options guidelines at follow-up compared to the AO condition. CONCLUSIONS: Findings suggest that delivering a brief web-based intervention with daily text messages about personal nutrition and fitness goals may support healthier eating patterns among students.

Web-based screening and brief intervention for student marijuana use in a university health center: pilot study to examine the implementation of eCHECKUP TO GO in different contexts.

This pilot study sought to test the feasibility of procedures to screen students for marijuana use in Student Health Services (SHS) and test the efficacy of a web-based intervention designed to reduce marijuana use and consequences. Students were asked to participate in voluntary screening of health behaviors upon arrival at SHS. One hundred and twenty-three students who used marijuana at least monthly completed assessments and were randomized to one of four intervention conditions in a 2 (intervention: Marijuana eCHECKUP TO GO vs. control)×2 (site of intervention: on-site vs. off-site) between-groups design. Follow-up assessments were conducted online at 3 and 6 months. Latent growth modeling was used to provide effect size estimates for the influence of intervention on outcomes. One thousand and eighty undergraduate students completed screening. The intervention did not influence marijuana use frequency. However, there was evidence of a small overall intervention effect on marijuana-related consequences and a medium effect in stratified analyses in the on-site condition. Analyses of psychological variables showed that the intervention significantly reduced perceived norms regarding peer marijuana use. These findings demonstrate that it is feasible to identify marijuana users in SHS and deliver an automated web-based intervention to these students in different contexts. Effect size estimates suggest that the intervention has some promise as a means of correcting misperceptions of marijuana use norms and reducing marijuana-related consequences. Future work should test the efficacy of this intervention in a full scale randomized controlled trial.