A marine biogenic source of atmospheric ice-nucleating particles.

The amount of ice present in clouds can affect cloud lifetime, precipitation and radiative properties. The formation of ice in clouds is facilitated by the presence of airborne ice-nucleating particles. Sea spray is one of the major global sources of atmospheric particles, but it is unclear to what extent these particles are capable of nucleating ice. Sea-spray aerosol contains large amounts of organic material that is ejected into the atmosphere during bubble bursting at the organically enriched sea-air interface or sea surface microlayer. Here we show that organic material in the sea surface microlayer nucleates ice under conditions relevant for mixed-phase cloud and high-altitude ice cloud formation. The ice-nucleating material is probably biogenic and less than approximately 0.2 micrometres in size. We find that exudates separated from cells of the marine diatom Thalassiosira pseudonana nucleate ice, and propose that organic material associated with phytoplankton cell exudates is a likely candidate for the observed ice-nucleating ability of the microlayer samples. Global model simulations of marine organic aerosol, in combination with our measurements, suggest that marine organic material may be an important source of ice-nucleating particles in remote marine environments such as the Southern Ocean, North Pacific Ocean and North Atlantic Ocean.

Rapid carbon accumulation at a saltmarsh restored by managed realignment exceeded carbon emitted in direct site construction.

Increasing attention is being paid to the carbon sequestration and storage services provided by coastal blue carbon ecosystems such as saltmarshes. Sites restored by managed realignment, where existing sea walls are breached to reinstate tidal inundation to the land behind, have considerable potential to accumulate carbon through deposition of sediment brought in by the tide and burial of vegetation in the site. While this potential has been recognised, it is not yet a common motivating factor for saltmarsh restoration, partly due to uncertainties about the rate of carbon accumulation and how this balances against the greenhouse gases emitted during site construction. We use a combination of field measurements over four years and remote sensing to quantify carbon accumulation at a large managed realignment site, Steart Marshes, UK. Sediment accumulated rapidly at Steart Marshes (mean of 75 mm yr-1) and had a high carbon content (4.4% total carbon, 2.2% total organic carbon), resulting in carbon accumulation of 36.6 t ha-1 yr-1 total carbon (19.4 t ha-1 yr-1 total organic carbon). This rate of carbon accumulation is an order of magnitude higher than reported in many other restored saltmarshes, and is somewhat higher than values previously reported from another hypertidal system (Bay of Fundy, Canada). The estimated carbon emissions associated with the construction of the site were ~2-4% of the observed carbon accumulation during the study period, supporting the view that managed realignment projects in such settings may have significant carbon accumulation benefits. However, uncertainties such as the origin of carbon (allochthonous or autochthonous) and changes in gas fluxes need to be resolved to move towards a full carbon budget for saltmarsh restoration.

Evaluating an online support package delivered within a disability unemployment service: study protocol for a randomised controlled feasibility study.

BACKGROUND: Mental health problems such as anxiety and depression are known to be higher in those who are unemployed. Cognitive behavioural therapy (CBT) is a recognised support for people with such problems and can improve the ability of people to get back to work. METHODS/DESIGN: Participants with symptoms of low mood will be recruited from the disability employment service, Remploy. Participants will receive either immediate or delayed access to an online CBT-based life skills intervention, the "Living Life" package. The primary end point will be at 3 months when the delayed group will be offered the intervention. This feasibility study will test the trial design and assess recruitment, retention, acceptability and adherence, as well as providing efficacy data. DISCUSSION: The study will inform the design and sample size for a future full randomised controlled trial (RCT) which will be carried out to determine the effectiveness of the online package in improving mood and employment status. TRIAL REGISTRATION: Current Controlled Trials ISRCTN10316077.

Electroconvulsive therapy for patients with major depression and probable Lewy body dementia.

Patients with dementia and depression are commonly encountered in ECT practice. A large body of case reports and case series in demented patients attests to the utility of ECT in treating concomitant depression in this population. However, there are no reported cases of patients with suspected Lewy Body dementia and depression treated with ECT. We describe our experience in treating seven such patients. All of them enjoyed substantial relief from depression with ECT, which they tolerated well. It is concluded that ECT can be effective in treating depression associated with probable Lewy Body dementia.