The Effects of Respiratory Sinus Arrhythmia Biofeedback on Heart Rate Variability and Posttraumatic Stress Disorder Symptoms: A Pilot Study

Recent studies have found a significant association between PTSD and low heart rate variability (HRV), a biomarker of autonomic dysregulation. Research indicates that respiratory sinus arrhythmia (RSA) biofeedback increases HRV while reducing related pathological symptoms. This controlled pilot study compared RSA biofeedback to progressive muscle relaxation (PMR) as adjunctive interventions for 38 persons with PTSD symptoms in a residential treatment facility for a substance use disorder. Both groups were assessed at pre-intervention and 4-week post-intervention. Group × time interactions revealed significantly greater reductions in depressive symptoms and increases in HRV indices for the RSA group. Both groups significantly reduced PTSD and insomnia symptoms and a statistical trend was observed for reduced substance craving for the RSA group. Increases in HRV were significantly associated with PTSD symptom reduction. Overall, these results provide preliminary support for the efficacy of RSA biofeedback in improving physiological and psychological health for individuals with PTSD.     

Earth observation: overlooked potential to support species reintroduction programmes

Habitat evaluation is considered an essential step for assessing the potential for an area to support a viable reintroduced population. Remote sensing techniques can support such investigations, by greatly enhancing the temporal and spatial coverage of habitat assessments. This study makes use of freely available earth observation data to evaluate the suitability of the Ouadi Rimé–Ouadi Achim Game Reserve in central Chad for the reintroduction of the Scimitar‐horned Oryx. The reserve was the last stronghold of the species within its historical range, prior to extinction in the wild in the 1980s, providing a basis for reintroduction. Results show that since the 1980s, there has been a steady increase in average annual precipitation and satellite‐derived estimates of primary production. The spatial downscaling of the average trend in primary production showed that the north of the protected area exhibited a drying trend over the period 1982–2008, while the south was associated with intense greening. As a result, the subdesert transition zone preferred by oryx is currently narrowing. If this is correct, this implies a potential reduction of favourable habitat for the oryx, which could have detrimental effects on the success of establishing a self‐sustaining reintroduced population.