Seedling Emergence of the Tree Legume Clathrotropis brunnea Amshoff, Endemic from a Colombian Tropical Rainforest

Seedling emergence is the main propagation method of forest species. Thus, we aimed to evaluate emergence aspects of the tree legume Clathrotropis brunnea Amshoff (sapán or blackheart sapán), a Fabaceae of high economic value endemic to the Colombian rainforest. We characterized the biometry of legumes and seeds and assessed seedling emergence in three experiments: (1) effect of fruit color and substrate, (2) seed conservation in storage, and (3) presoaking and seed position. Our results showed that seeds of green-yellow fruits have greater length and weight and a water content of up to 53%. Seedling emergence did not differ between green-yellow and dark-brown fruits but did differ with substrate type; nearly 80% of seedlings emerged in the sand substrate (S1), but only 62% emerged in the mixed substrate (S3). Fresh sapán seeds are nondormant, showing a recalcitrant behavior in which seedling emergence decreased after storage in all tested conditions. Both seed-sowing positions allowed an emergence of >80% with a small benefit of the hilum downward, regardless of presoaking treatments. However, these differences did not affect seedling height or biomass after emergence. Our results provide basic knowledge on production of tropical seedlings, seeking species conservation, and use in restoration projects. Study Implications Our study provides information on seedling emergence of a legume tree endemic to the Colombian rainforest, Clathrotropis brunnea Amshoff. Because the species has a high economic value, it has been overexploited in the Middle Magdalena Valley. We have found that C. brunnea seeds are not dormant, and thus fresh seeds could easily germinate and form seedlings in the nursery, but such seeds are sensitive to desiccation during storage (recalcitrant). Therefore, other factors such as deforestation and climatic changes may threaten its regeneration from seeds and propagation techniques are urgently needed for its conservation.

Pooled platelet concentrates provide a small benefit over single-donor platelets for patients with platelet refractoriness of any etiology

Background At our institution, patients with platelet refractoriness (of any etiology) are sometimes switched from apheresis platelets to pooled platelets before human leukocyte antigen (HLA)-matched units become available. Study design and methods Seven patients were analyzed. Platelet counts were available from 57 single-unit transfusions (26 pooled, 31 apheresis). A mixed linear effects model was used and significance was determined using a likelihood ratio test. Results When analyzed as the only fixed effect in the model, the use of pooled versus single-donor units and time from transfusion to post-transfusion blood sampling each showed a significant effect on platelet count increments. A mixed linear effect model including both factors showed that transfusing a pooled unit correlated with a 4500±2000/µL greater platelet count increment compared with a single-donor unit, and an increase in time from transfusion to post-transfusion blood sampling lowered the platelet count increment by 300±100/µL per hour. Conclusion A small but potentially clinically relevant benefit was observed in transfusing pooled random-donor platelets compared with single-donor units for patients with platelet refractoriness (of any etiology).

Probabilistic Risk Assessment of Prophylactic Surgery Before Extended-Duration Spaceflight

Introduction. Prophylactic surgery before spaceflight may eliminate the risk of appendicitis and cholecystitis in astronauts on deep space missions. However, even minimally invasive surgery increases the risk of small bowel obstruction (SBO). Probabilistic risk assessment (PRA) is a method that can be used to estimate the benefits and risks of prophylactic surgery. Methods. Risks of appendicitis and cholecystitis during a 2.5-year Mars mission are compared to the risk of SBO after laparoscopic removal of the appendix, gallbladder, or both. A PRA model using Monte Carlo methodology was used to forecast the risks. Results. Prophylactic appendectomy and cholecystectomy combined, conferred an increased probability of medical evacuation (pEVAC) due to SBO as compared to the no surgery group. A slightly higher probability for the loss of crew life (pLOCL) was found in the no surgery group when compared to the cases in which either prophylactic appendectomy alone, or appendectomy plus cholecystectomy are performed. Discussion. The need for medical evacuation can be viewed as a potential risk for death in the context of a space mission where evacuation is not possible. Because of the higher pEVAC due to SBO and relatively small benefit in the reduction of pLOCL in the prophylactic surgery groups, this analysis does not support the prophylactic removal of appendix and/or gallbladder for spaceflight. Future advances in surgical or medical technique or mission medical capabilities may change these results. This work demonstrates the utility of PRA in providing quantitative answers to “what if” questions where limited information is available.

Strengthening Pupils’ Physical Activity through Outdoor Education

The time pupils spend at school provides a very small benefit to pupils’ movement activity. At a time when many school-age children lack physical activity, it is necessary to think about how to integrate more movement into the period that the child spends at school. The paper is based on the assumption that outdoor education can contribute to the development of movement activity of pupils, and the paper aims to determine to what extent. For model pupils, the calorie count and metabolic discharge, including sedentary analysis, were recorded through an ActiGraph accelerometer during 4-hour lessons of different types of education days. The result is that outdoor education can serve as an appropriate complement to learning that contributes to the development of pupils’ knowledge and skills while working in a real environment but also acts as a mean of increasing the possibilities for movement for pupils during their schooling.

The attitudes of Greeks towards second-hand smoke and the anti-tobacco legislation

Greece had according to Eurobarometer 2017 the highest rates of secondhand smoke exposure in the European Union (87%). The main aim of this study was to understand the reasons for the non-enforcement of the anti-tobacco legislation. To do this, we created two different questionnaires, one for smokers and one for non-smokers, and we collected epidemiological data, data about the attitudes of Greeks towards smoking, second-hand smoke, and the smoke-free legislation, as well as data about some relevant behavioural patterns. In total 597 non-smoker questionnaires and 366 smoker questionnaires were collected, with the mean age of the participants being 40 years old. The majority of people claimed that smoke disturbs them and, interestingly, smokers responded that they consider disturbing others with their smoke, and especially when children are present. Additionally, smokers said they would slightly reduce going out if the smoke-free legislation was strictly enforced, while non-smokers would respectively slightly increase going out. Based on this observation and given the higher proportion of non-smokers than smokers, we can assume that there will be no negative impact to the eating and drinking establishments, as many people were speculating, but to the opposite, there might even be a small benefit from the implementation of smoke-free measures. Since 2019 the relevant legislation has been enforced, but due to the COVID-19 pandemic, the long-term implementation and the true outcomes of the relevant legislation are more difficult to study.

Comparison of Arthroscopic Partial Meniscectomy to Physical Therapy following Degenerative Meniscus Tears: A Systematic Review and Meta-analysis

Objective. To compare the effectiveness of arthroscopic partial meniscectomy (APM) and physical therapy (PT) for degenerative meniscus tears. Method. We conducted a literature search through PubMed, Embase, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov. Randomized controlled trials in adults with degenerative meniscal tears without symptoms of locking were considered for inclusion. Two researchers independently performed the literature search, assessed the risk of bias, and selected eligible studies. The primary outcome was function at different follow-up time points and the secondary outcome was pain at different follow-up time points. Results. We included 6 randomized controlled trials, with a total of 1006 participants, among which 495 were in the APM group and 511 were in the PT group. We found a small benefit in functional outcomes in the APM group until the 12 months follow-up time point (SMD=0.20; 95%CI=0.0‐0.33; p=0.002; I2=34%), but no significant differences in function between groups at the 24-month follow-up time point (SMD=0.12; 95%CI=−0.04−0.28;p=0.14; I2=28%). There was also small benefit in the APM group until the 12 months follow-up time point for pain (SMD=0.14; 95%CI=0.01−027; p=0.03; I2=36%), but no significant difference in pain between groups at 24 months (SMD=0.11; 95%CI=−0.05−0.28; p=0.18; I2=0%). Conclusion. In the treatment of degenerative meniscus tears, APM yielded better functional and pain outcomes compared with physical therapy in the short term until 12 months, but there were comparable results for pain and functional outcomes between the groups at the 24 months follow-up time point.

The Evolution of Mass Cell Suicide in Bacterial Warfare

SUMMARYBehaviours that reliably cause the death of an actor are typically strongly disfavoured by natural selection, and yet many bacteria undergo cell lysis to release anti-competitor toxins [1–4]. This behaviour is most easily explained if only a few cells die to release toxins and help their clonemates, but the number of cells that actually lyse during bacterial warfare is unknown. The challenge is that one cannot distinguish cells that have undergone programmed suicide from those that were simply killed by a competitor’s toxin. We developed a two-colour fluorescence reporter assay in Escherichia coli to overcome this problem. Surprisingly, this revealed conditions where nearly all cells undergo programmed lysis. Adding a DNA-damaging toxin (DNase colicin) to a focal strain causes it to engage in mass cell suicide where around 85% of cells lyse to release their own toxin. Time-lapse 3D confocal microscopy revealed that self-lysis occurs at even higher frequencies (~94%) at the interface between competing colonies. We sought to understand how such high levels of cell suicide could be favoured by natural selection. Exposing E. coli that do not perform lysis to the DNase colicin revealed that mass lysis only occurs when cells are going to die anyway from toxin exposure. From an evolutionary perspective, this renders the behaviour cost-free as these cells have zero reproductive potential. This explains how mass cell suicide can evolve, as any small benefit to surviving clonemates can lead to the strategy being favoured by natural selection. Our findings have strong parallels to the suicidal attacks of social insects [5–8], which are also performed by individuals with low reproductive potential, suggesting convergent evolution in these very different organisms.HIGHLIGHTSA novel assay can detect Escherichia coli undergoing cell suicide to release toxinsWe quantified the frequency of suicidal self-lysis during competitionsUnder some conditions, nearly all cells will self-lyse to release toxinsSelf-lysis makes evolutionary sense as cells will die anyway from competitors’ toxins

COVID-19 and economic recovery in compliance with climate targets

Non-technical summary A small benefit of the disastrous COVID-19 pandemic has been the temporary reduction in greenhouse gas emissions. Therefore, this paper asks: what strategies can return people to work without returning to the old high-emissions economy? How can we modify the old economic system to reduce environmental impacts while rebuilding employment? Technological change, such as replacing fossil fuels with renewable energy (RE), is necessary but, in an economy that's growing, unlikely to be sufficiently rapid to avoid dangerous climate change. Degrowth in physical consumption, especially by the ‘rich’ 10%, towards a steady-state economy, is needed as well as low-carbon jobs.