RESUMEN
BACKGROUND: Behavioral weight loss interventions promote clinically significant weight loss over 12 months, but weight regain remains problematic and a substantial proportion of participants do not achieve long-term weight loss maintenance. Novel methods are needed that instill habit strength for sustaining weight control behaviors long term. Virtual reality (VR) has the potential to provide opportunities within behavioral treatment for patients to practice desired weight control behaviors in the frequency and magnitude necessary to build durable habits. A pilot randomized trial was done to test the feasibility integrating virtual reality (VR) into standard behavioral weight loss treatment. METHODS: Participants were 15 adults (43 years; 46.7% Hispanic), with overweight or obesity who were randomly assigned to a 4-week Standard Behavioral Weight Loss plus Non-Weight-Related VR app (i.e., Control Group) or Standard Behavioral Weight Loss plus Weight-Related VR app (i.e., Intervention Group). The Intervention's VR tool was designed to enable practice of behavioral skills taught in weekly group meetings, including managing social and home environmental cues for eating and activity. RESULTS: Participants were recruited over 3 months, and retention at the final assessment visit was high (86.6%). The VR footage and resulting app were rated as highly realistic (6.7 on a 10-point scale), and the VR program overall was rated as highly satisfactory (3.6 on a 4-point scale). Adverse effects of eye strain and motion sickness were minimal (~ 2 on a 7-point scale). As expected, the intervention and control groups both lost weight and unadjusted means (SD) averaged 3.4% (2.7) and 2.3% (3.6), respectively, over the 4 weeks. Overall, participants reported preferring a VR approach above traditional weight loss programs (rating of 5 on a 7-point scale). CONCLUSIONS: Future research is needed to develop and test the feasibility of using VR for other weight control skills with a larger sample size and longer evaluation period to determine if VR can improve standard behavioral weight loss outcomes by intensifying practice opportunities and building habit strength for weight loss maintenance. TRIAL REGISTRATION: NCT04534088 ; date of registration: 09/01/2020, retrospectively registered.
RESUMEN
Full-spectrum, ultraviolet (UV), and visible broadband apparent quantum yields (AQYs) for carbon monoxide (CO) photoproduction from chromophoric dissolved organic matter (CDOM) and particulate organic matter (POM) were determined in the Delaware Estuary in two hydrologically contrasting seasons in 2012: an unusually low flow in August and a storm-driven high flow in November. Average AQYs for CDOM and POM in November were 10 and 16 times the corresponding AQYs in August. Maximum AQYs in November occurred in a midestuary particle absorption maximum zone. Although POM AQYs were generally smaller than CDOM AQYs, the ratio of the former to the latter increased substantially from the UV to the visible. In both seasons, UV solar radiation was the primary driver for CO photoproduction from CDOM whereas visible light was the principal contributor to POM-based CO photoproduction. CDOM dominated CO photoproduction in the uppermost water layer while POM prevailed at deeper depths. On a depth-integrated basis, the Delaware Estuary shifted from a CDOM-dominated system in August to a POM-dominated system in November with respect to CO photoproduction. This study reveals that flood events may enhance photochemical cycling of terrigenous organic matter and switch the primary photochemical driver from CDOM to POM.
