Contrasting effects of elevated CO2 and water deficit on two native herbs

This study investigated the effects of carbon dioxide (CO)2 enrichment and soil water deficit on the water use efficiency (WUE) and growth of Sanguisorba minor Scop, (salad burnet I and Anthyllis vulneraria L. (kidney vetch), growing in controlled environments. Instantaneous WL E (IWUE) increased in both species in elevated CO2, with a higher average increase in unwatered (UW) A. vulneraria over the drying cycle. Total plant WUE of A. vulneraria increased in elevated CO, and under water deficit: the UW plants in elevated CO., had higher WUE and reduced water loss. By contrast, thee was only an effect of water supply on S. minor: total plant WUE increased and water loss decreased in the UV plants in both CO2, treatments. Total apparent root length (ARL) of both species increased with CO2, enrichment and in UW S. minor total ARL was increased. By contrast, for A. vulneraria, total ARL of UV plants increased in ambient CO2, but decreased in elevated CO2 as compared with well-watered (WW) plants. Shoot dry weight (SDW) and root dry weight increased in both species (WW and UW) with CO2. enrichment. For UW S. minor, SDW decreased relative to WW plants in both CO2 treatments. By contrast, ANOVA showed no significant effect of water supply on SDW of A. vulneraria. Leafier length increased in both species in elevated CO2, and decreased following drought. Cell wall tensiometric extensibility (%P) increased in expanding leaves of S. minor in elevated CO., and for both species %P decreased in the UW plants as compared with those WW. Leaf water potential (f) of both species was lower in growing leaves of WAV plants in elevated CO2 Water deficit reduced the ? of growing leaves in both CO2, treatments. The different responses of these species suggest that in a drier, enriched CO2, environment survival in a community might depend on their ability to maintain growth at the same time as conserving water

The Positive Outlook Study: A Randomised Controlled Trial Evaluating Online Self-Management for HIV Positive Gay Men

The aim of this paper was to evaluate the effectiveness of an online self-management program in improving health outcomes and well-being for gay men living with HIV in Australia. The online Positive Outlook Program was based on self-efficacy theory and used a self-management approach to enhance HIV-positive gay men’s skills, confidence and abilities to manage the psychosocial issues associated with HIV in daily life. The 7-week program was delivered in closed groups and comprised information modules, action-planning activities, moderated discussion boards, and weekly peer-facilitated ‘live chats’. A randomised controlled trial was conducted to establish the effectiveness of the Positive Outlook program compared to a ‘usual care’ control. Participants were HIV-positive gay men 18 years or older living in Australia. Primary outcomes were evaluated at three time-points (baseline, post-intervention and 12-week’s post-intervention follow-up) and included HIV-related quality of life (PROQOL-HIV), outcomes of health education (HeiQ) and HIV specific self-efficacy (Positive Outlook Self-Efficacy Scale). A total of 132 gay men with HIV in Australia were randomly allocated to the intervention (n = 68) or usual care control (n = 64) groups. Maximum likelihood marginal-linear modelling indicated significant improvement in the intervention group on the PROQOL-HIV subscales of body change (p = 0.036), social relationships (p = 0.035) and emotional distress (p = 0.031); the HeiQ subscales of health-directed activity (p = 0.048); constructive attitudes and approaches (p = 0.015); skill and technique acquisition (p = 0.046) and health service navigation (p = 0.008); and the Positive Outlook Self-Efficacy Scale on the subscales of relationships (p = 0.019); social participation (p = 0.006); and emotions (p = 0.041). Online delivery of self-management programs is feasible and has the potential to improve quality of life, self-management skills and domain specific self-efficacy for gay men with HIV