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Shallow lakes and ponds undergo frequent temporary thermal stratification. How this affects greenhouse gas (GHG) emissions is moot, with both increased and reduced GHG emissions hypothesised. Here, weekly estimations of GHG emissions, over the growing season from May to September, were combined with temperature and oxygen profiles of an 11 ha temperate shallow lake to investigate how thermal stratification shapes GHG emissions. There were three main stratification periods with profound anoxia occurring in the bottom waters upon isolation from the atmosphere. Average diffusive emissions of methane (CH 4) and nitrous oxide (N 2 O) were larger and more variable in the stratified phase, whereas carbon dioxide (CO 2) was on average lower, though these differences were not statistically significant. In contrast, there was a significant order of magnitude increase in CH 4 ebullition in the stratified phase. Furthermore, at the end of the period of stratification, there was a large efflux of CH 4 and CO 2 as the lake mixed. Two relatively isolated turnover events were estimated to have released the majority of the CH 4 emitted between May and September. These results demonstrate how stratification patterns can shape GHG emissions and highlight the role of turnover emissions and the need for high-frequency measurements of GHG emissions, which are required to accurately characterise emissions, particularly from temporarily stratifying lakes. [ABSTRACT FROM AUTHOR]

Aims and objectivesThis randomised controlled trial was conducted to estimate the cost-effectiveness of a nurse-led education and psychosocial support programme for patients with heart failure (HF) and their partners.BackgroundThere are few studies evaluating cost-effectiveness of interventions among HF patient-partner dyads.MethodsDyads randomised to the experimental group received nurse-led counselling, computer-based education and written materials aimed at developing problem-solving skills at two, six and 12 weeks after hospitalisation with HF exacerbation. The dyads in the control group received usual care. A cost-effectiveness analysis that included costs associated with staff time to deliver the intervention and travel costs was conducted at 12 months. Quality-adjusted life-year (QALY) weights for patients and partners were estimated by SF-6D.ResultsA total of 155 dyads were included. The intervention cost was €223 per patient. Participants in both groups showed improvements in QALY weights after 12 months. However, no significant difference in QALY weights was found between the patients in the two groups, nor among their partners.ConclusionThe intervention was not proven cost-effective, neither for patients nor for partners. The intervention, however, had trends (but not significant) effects on the patient-partner dyads, and by analysing the QALY gained from the dyad, a reasonable mean cost-effectiveness ratio was achieved.Relevance to clinical practiceThe study shows trends of a cost-effective education and psychosocial care of HF patient-partner dyads.

Objectives: To evaluate the cost‐effectiveness of root canal treatment (RCT) compared with a tooth extraction in a general dental practice setting, with reference to cost per quality‐adjusted life‐year (QALY) gained over 1 year. Material and Methods: This is a prospective controlled cohort study based on patients either starting RCT or undergoing extraction at one of six Public Dental Service clinics in the county of Västra Götaland, Sweden. From a total of 65 patients, 2 comparable groups were formed: 37 started RCT and 28 underwent extraction. A societal perspective was used for the cost calculations. QALYs were estimated, based on the EQ‐5D‐5L given to the patients at their first treatment appointment and then after 1, 6, and 12 months. Results: The total mean cost of RCT ($689.1) was higher than for extraction ($280.1). For those patients whose extracted tooth was replaced, the costs were even higher ($1245.5). There were no significant intergroup differences in QALYs, but a significant improvement in health state values in the tooth‐preserving group. Conclusions: In the short term, extraction was cost‐effective compared with preserving a tooth with RCT. However, the potential need for future replacement of the extracted tooth, by an implant, fixed prosthesis, or removable partial dentures, may change the calculation in favor of RCT. [ABSTRACT FROM AUTHOR]