Efficient carbon recycling between calcification and photosynthesis in red coralline algae.

Red coralline algae create abundant, spatially vast, reef ecosystems throughout our coastal oceans with significant ecosystem service provision, but our understanding of their basic physiology is lacking. In particular, the balance and linkages between carbon-producing and carbon-sequestering processes remain poorly constrained, with significant implications for understanding their role in carbon sequestration and storage. Using dual radioisotope tracing, we provide evidence for coupling between photosynthesis (which requires CO2) and calcification (which releases CO2) in the red coralline alga Boreolithothamnion soriferum (previously Lithothamnion soriferum)-a marine ecosystem engineer widely distributed across Atlantic mid-high latitudes. Of the sequestered HCO3 -, 38 ± 22% was deposited as carbonate skeleton while 39 ± 14% was incorporated into organic matter via photosynthesis. Only 38 ± 2% of the sequestered HCO3 - was transformed into CO2, and almost 40% of that was internally recycled as photosynthetic substrate, reducing the net release of carbon to 23 ± 3% of the total uptake. The calcification rate was strongly dependent on photosynthetic substrate production, supporting the presence of photosynthetically enhanced calcification. The efficient carbon-recycling physiology reported here suggests that calcifying algae may not contribute as much to marine CO2 release as is currently assumed, supporting a reassessment of their role in blue carbon accounting.

Military and demographic predictors of mental ill-health and socioeconomic hardship among UK veterans.

BACKGROUND: Around 8% of the UK Armed Forces leave in any given year, and must navigate unfamiliar civilian systems to acquire employment, healthcare, and other necessities. This paper determines longer-term prevalences of mental ill health and socioeconomic outcomes in UK Service leavers, and how they are related to demographic factors, military history, and pre-enlistment adversity. METHODS: This study utilised data from a longitudinal sample of a cohort study UK Armed Forces personnel since 2003. A range of self-reported military and sociodemographic factors were analysed as predictors of probable Post-Traumatic Stress Disorder, common mental disorders, alcohol misuse, unemployment and financial hardship. Prevalences and odds ratios of associations between predictors and outcomes were estimated for regular veterans in this cohort. RESULTS: Veteran hardship was mostly associated with factors linked to socio-economic status: age, education, and childhood adversity. Few military-specific factors predicted mental health or socio-economic hardship, except method of leaving (where those leaving due to medical or unplanned discharge were more likely to encounter most forms of hardship as veterans), and rank which is itself related to socioeconomic status. CONCLUSION: Transition and resettlement provisions become increasingly generous with longer service, yet this paper shows the need for those services becomes progressively less necessary as personnel acquire seniority and skills, and instead could be best targeted at unplanned leavers, taking socioeconomic status into consideration. Many will agree that longer service should be more rewarded, but the opposite is true if provision instead reflects need rather than length of service. This is a social, political and ethical dilemma.

Service evaluation of a Human Givens Therapy service for veterans.

BACKGROUND: PTSD Resolution is a charitable provider of mental health support and treatment via Human Givens Therapy to members of the Armed Forces Community. This study utilized data from their client database to evaluate outcomes of their services. AIMS: To determine whether treatment by the service resulted in improvements in mental health; to the extent possible, compare these outcomes with those of NHS IAPT (National Health Service - Improving Access to Psychological Therapies) services; and to evaluate how other factors, notable reported stress levels and prior treatment, impacted outcomes. METHODS: Administratively collected data from the service provider collected between 2014 and 2016 were utilized. Clients still undergoing services were excluded. The CORE-10 (10-item Clinical Outcomes in Routine Evaluation) measure was used as the outcome measure. Demographic factors examined included age, sex, employment, accommodation, relationship status, distress at the time of presentation and prior treatment history. The effect of the factors was analysed using χ2 test as well as linear regression and Poisson regression analyses according to the nature of the variable. RESULTS: PTSD Resolution clients appeared to show a similar degree of improvement as IAPT patients. Job-seekers and those who are living alone benefited less from the treatment. Despite high levels of distress and prior treatment among this client group, these factors did not seem to affect treatment outcomes. CONCLUSIONS: The services of this provider appear to be an acceptable alternative for IAPT treatment, to the degree such a comparison can be made given differences in measures and client groups.

Do Junior Entrants to the UK Armed Forces have worse outcomes than Standard Entrants?

INTRODUCTION: The UK is the only permanent member of the UN Security Council that has a policy of recruiting 16 and 17 year old individuals into its regular Armed Forces. Little is known about the consequences of enlisting as a Junior Entrant (JE), although concerns have been expressed. We compare the mental health, deployment history, and pre-enlistment and post-enlistment experiences of personnel who had enlisted as JEs with personnel who joined as Standard Entrants (SEs). METHOD: Participants from a large UK military cohort study completed a self-report questionnaire between 2014 and 2016 that included symptoms of probable post-traumatic stress disorder (PTSD), common mental disorders, alcohol consumption, physical symptoms and lifetime self-harm. Data from regular non-officer participants (n=4447) from all service branches were used in the analysis. JEs were defined as having enlisted before the age of 17.5 years. A subgroup analysis of participants who had joined or commenced adult service after April 2003 was carried out. RESULTS: JEs were not more likely to deploy to Iraq or Afghanistan but were more likely to hold a combat role when they did (OR 1.25, 95% CI 1.00 to 1.56). There was no evidence of an increase in symptoms of common mental disorders, PTSD, multiple somatic symptoms (MSS), alcohol misuse or self-harm in JEs in the full sample, but there was an increase in alcohol misuse (OR 1.84, 95% CI 1.18 to 2.87), MSS (OR 1.51, 95% CI 1.04 to 2.20) and self-harm (OR 2.13, 95% CI 1.15 to 3.95) in JEs who had commenced adult service after April 2003. JEs remain in adult service for longer and do not have more difficulties when they leave service. CONCLUSIONS: JEs do not have worse mental health than SEs, but there is uncertainty in relation to alcohol misuse, MSS and self-harm in more recent joiners. Monitoring these concerns is advisable.

The subjective utility of early psychosocial interventions following combat deployment.

BACKGROUND: Third Location Decompression (TLD) is the process through which personnel, returning from combat operations, begin to psychologically 'unwind'. Decompression comprises welfare activities, such as contacting home, beach events, social events, psycho-educational briefings and controlled re-introduction to alcohol. AIMS: To assess the subjective utility of decompression by surveying all British troops transiting the TLD facility in Cyprus, during 2008. METHODS: Analysis of distributed surveys completed by personnel who had deployed either to Iraq or Afghanistan. The main outcome was the subjective utility of the decompression process, with operational exposures, stigma, early post-traumatic stress (PTS) symptoms and adjustment concerns also measured. RESULTS: Response rate was 87% (11,304 returned surveys). Eighty per cent of respondents reported being ambivalent or not wanting to go through TLD before decompression; however, on completion, 91% reported finding it useful. The desire to participate was the strongest predictor of perceived helpfulness. Troops who found the TLD less helpful included those who had been through the process before, combat troops and non-commissioned officers. Twelve per cent reported substantial concerns about re-establishing relationships or settling down to 'normal life'; those reporting more adjustment concerns were more likely to perceive TLD as helpful. Six per cent reported significant PTS symptoms and 27% of troops reported substantial levels of stigma related to mental health and barriers to care. CONCLUSIONS: TLD was well received by troops following combat deployment. However, TLD does not appear to be equally acceptable to all and alterations to the TLD programme for certain subgroups might be required.

Species-specific impact of microplastics on coral physiology.

There is evidence that microplastic (MP) pollution can negatively influence coral health; however, mechanisms are unknown and most studies have used MP exposure concentrations that are considerably higher than current environmental conditions. Furthermore, whether MP exposure influences coral susceptibility to other stressors such as ocean warming is unknown. Our objective was to determine the physiology response of corals exposed to MP concentrations that have been observed in-situ at ambient and elevated temperature that replicates ocean warming. Here, two sets of short-term experiments were conducted at ambient and elevated temperature, exposing the corals Acroporasp. and Seriatopora hystrix to microspheres and microfibres. Throughout the experiments, gross photosynthesis and net respiration was quantified using a 4-chamber coral respirometer, and photosynthetic yields of photosystem II were measured using Pulse-Amplitude Modulated (PAM) fluorometry. Results indicate the effect of MP exposure is dependent on MP type, coral species, and temperature. MP fibres (but not spheres) reduced photosynthetic capability of Acropora sp., with a 41% decrease in photochemical efficiency at ambient temperature over 12 days. No additional stress response was observed at elevated temperature; photosynthetic performance significantly increased in Seriatopora hystrix exposed to MP spheres. These findings show that a disruption to coral photosynthetic ability can occur at MP concentrations that have been observed in the marine environment and that MP pollution impact on corals remains an important aspect for further research.

The potential for coral reef establishment through free-living stabilization.

Corals thrive in a variety of environments, from low wave and tidal energy lagoons, to high energy tidal reef flats, but remain dependent upon suitable substrate. Herein we reviewed the phenomenon of free-living corals (coralliths), examined whether they have the capacity to create their own stable habitat in otherwise uninhabitable, poor substrate environments through 'free-living stabilization', and explore their potential ecological role on coral reefs. This stabilization could be achieved by coral settlement and survival on mobile substrate, with subsequent growth into free-living coralliths until a critical mass is reached that prevents further movement. This allows for secondary reef colonization by other coral species. To preliminarily test this hypothesis we provide evidence that the potential to support secondary coral colonisation increases with corallith size. Due to the limited diversity of corallith species observed here and in the literature, and the lack of physiological differences exhibited by coralliths here to static controls, it seems likely that only a small selection of coral species have the ability to form coralliths, and the potential to create their own stable habitat.

Evidence for phosphonate usage in the coral holobiont.

Phosphonates are characterized by a stable carbon-phosphorus bond and commonly occur as lipid conjugates in invertebrate cell membranes. Phosphonoacetate hydrolase encoded by the phnA gene, catalyses the cleavage of phosphonoacetate to acetate and phosphate. In this study, we demonstrate the unusually high phnA diversity in coral-associated bacteria. The holobiont of eight coral species tested positive when screened for phnA using degenerate primers. In two soft coral species, Sinularia and Discosoma, sequencing of the phnA gene showed 13 distinct groups on the basis of 90% sequence identity across 100% of the sequence. A total of 16 bacterial taxa capable of using phosphonoacetate as the sole carbon and phosphorus source were isolated; 8 of which had a phnA+ genotype. This study enhances our understanding of the wide taxonomic and environmental distribution of phnA, and highlights the importance of phosphonates in marine ecosystems.