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Background: In light of political discussions about minimum case volumes and certified lung cancer centers, this observational study investigates differences in therapy and survival between high vs. low patient volume hospitals (HPVH vs. LPVH).Methods: We identified 12,374 lung cancer patients treated in HPVH (>67 patients) and LPVH in 2013 from German health insurance claims. Stratified by metastasis status (no metastases, nodal metastases, systemic metastases), we compared HPVHs and LPVHs regarding likelihood of resection and systemic therapy, type of systemic therapy, and surgical outcomes, using multivariate logistic models. Three-year survival was modeled using Cox regression. We adjusted all regression models for age, gender, comorbidity, and residence area, and included a cluster variable for the hospital.Results: Around 24 % of patients were treated in HPVHs. Irrespective of stratum and subgroup, three-year survival was significantly better in HPVHs. In patients with systemic metastases (OR = 1.84, CI=[1.22,2.76]) and without metastases (OR = 3.28, CI=2.13, 5.04]), resection was more likely in HPVHs. Among patients with systemic therapy, the odds of receiving pemetrexed was higher in HPVHs, in patients with nodal metastases (OR = 1.57, CI=1.01,2.45]). In resected patients without metastases the odds ratio of receiving a thoracoscopic lobectomy was 2.28 (CI=1.04,4.99]) in HPVHs.Conclusion: Our data suggests that case volume is clinically relevant in resected and non-resected lung cancer patients, but optimal minimum case volumes may differ for subgroups. (C) 2020 Published by Elsevier B.V.

Ca2+ is a potent signalling molecule that regulates many cellular processes. In cyanobacteria, Ca2+ has been linked to cell growth, stress response and photosynthesis, and to the development of specialist heterocyst cells in certain nitrogen-fixing species. Despite this, the pathways of Ca2+ signal transduction in cyanobacteria are poorly understood, and very few protein components are known. The current study describes a previously unreported Ca2+-binding protein which was called the Ca2+ Sensor EF-hand (CSE), which is conserved in filamentous, nitrogen-fixing cyanobacteria. CSE is shown to bind Ca2+, which induces a conformational change in the protein structure. Poor growth of a strain of Anabaena sp. PCC 7120 overexpressing CSE was attributed to diminished photosynthetic performance. Transcriptomics, biophysics and proteomics analyses revealed modifications in the light-harvesting phycobilisome and photosynthetic reaction centre protein complexes.

Drought stress is one of the major stressors for plants under climate change, depressing growth through inhibition of photosynthesis and causing oxidative cell damage. It has been shown that plants can form a drought stress memory, improving their performance under recurring drought stress after they have been primed by drought before. Mechanisms underlying such a drought stress memory and possible cross-stress tolerance (improved performance to drought after plants have been stressed by other stressors) are currently unclear. We aimed to test whether previous waterlogging stress and drought stress leads to improved performance and changes in morphological, photosynthetic and anti-oxidative parameters under recurring drought. Therefore, we repeatedly subjected Alopecurus pratensis grass plants to waterlogging and drought over two years. In the third year, plants were well-watered for three weeks to recover and then subjected to drought stress for two weeks. Plants primed with drought before showed less tissue damage and higher levels of Rubisco content, anti-oxidative enzymes (POX, SOD) and chlorophyll b after the recovery and the drought period. We show for the first time a long-term drought stress memory in a grass species, lasting over several weeks. Our results indicate that drought priming enhances the activity of anti-oxidative enzymes, which is key for depressing oxidative damage and for improving tolerance to subsequent drought stress in A. pratensis.

Under climate change, not only the magnitude, but also the frequency of extreme weather events is predicted to increase. Such repeated climate stress events may cause fundamental shifts in species compositions or ecosystem functioning. Yet, few studies document such shifts. One reason for higher stability of ecosystems than previously expected may be ecological stress memory at the single plant level. Ecological stress memory is defined here as any response of a single plant after a stress experience that modifies the response of the plant towards future stress events including the mode of interaction with other ecological units. Ecological stress memory is assessed on a whole plant level in ecological relevant parameters. It is therefore one important aspect of the broader concept of ecological memory that refers to whole communities and ecosystems. Here, we present studies which indicate the existence of ecological stress memory within single plants after drought, frost or heat stress. Possible mechanisms underlying an ecological stress memory are the accumulation of proteins, transcription factors or protective metabolites, as well as epigenetic modifications or morphological changes. In order to evaluate the importance of stress memory for stabilizing whole ecosystems and communities in times of climate change, cooperation between ecologists and molecular biologists is urgently needed, as well as more studies investigating stress memory on a single plant level. Only then the potential of plant stress memory for stabilizing ecosystems in times of intensifying climatic extremes can be evaluated and taken into account for measures of mitigation and adaptation to climate change.

Climate change is likely to alter decomposition rates through direct effects on soil biotic activity and indirect effects on litter quality with possible impacts on the global carbon budget and nutrient cycling. Currently, there is a need to study the combined effects of climatic drivers and agricultural practises on decomposition. In an in situ litter bag experiment, we studied the effects of rainfall variability (including drought combined with heavy rain pulses as well as regular irrigation) interacting with winter warming and increased winter precipitation and with changes in cutting frequency, on decomposition in a temperate grassland. Litter bags contained mixed and species-specific litter of all different climate and land-use manipulations and were placed within the plots of litter origin. Moreover, we aimed to disentangle the causes of changes in decomposition by investigating two further approaches: Firstly, we studied the effects of changes in leaf chemicals as a result of the manipulations by removing litter from the experiment that has been pre-exposed to the manipulations before placing it on an untreated standard plot outside the experiment. Secondly, we assessed the effects of changes in soil faunal activity by investigating the decomposition of standard material under differing rainfall variability. As a result, decomposition was reduced when litter bags were exposed to drought for six weeks within an 11 months period. Neither additional winter rain nor winter warming had an effect on decomposition, likely because winter warming reduced snow cover and increased variability of surface temperatures. Climate manipulations did not change litter quality. Furthermore, decomposition on the untreated standard plot was not affected by the climate manipulations that the litter was previously exposed to. Thus, reduced decomposition under extreme rainfall variability and drought may mainly be caused by a decrease in soil biotic activity, as indicated by reduced decomposition of standard material during drought. More frequent cutting strongly stimulated decomposition, however, this stimulating effect was absent under extreme rainfall variability including drought. The stimulation of decomposition under more frequent cutting was attributed to changes in litter quality, namely a decrease in C/N ratio. Accordingly, litter from more frequently cut communities decomposed faster on the untreated control plot outside the experiment. Projected increases in drought frequency and increased rainfall variability under climate change may inhibit decomposition and alter nutrient and carbon cycling along with soil quality. Especially decomposition in frequently cut grassland appears vulnerable towards drought.

The proton-pumping NADH:ubiquinone oxidoreductase, respiratory complex I, couples the electron transfer from NADH to ubiquinone with the translocation of protons across the membrane. In Escherichia coli the complex is made up of 13 different subunits encoded by the so-called nuo-genes. Mutants, in which each of the nuo-genes was individually disrupted by the insertion of a resistance cartridge were unable to assemble a functional complex I. Each disruption resulted in the loss of complex I-mediated activity and the failure to extract a structurally intact complex. Thus, all nuo-genes are required either for the assembly or the stability of a functional E. coli complex I. The three subunits comprising the soluble NADH dehydrogenase fragment of the complex were detected in the cytoplasm of several nuo-mutants as one distinct band after BN-PAGE. It is discussed that the fully assembled NADH dehydrogenase fragment represents an assembly intermediate of the E. coli complex I. A partially assembled complex I bound to the membrane was detected in the nuoK and nuoL mutants, respectively. Overproduction of the ΔNuoL variant resulted in the accumulation of two populations of a partially assembled complex in the cytoplasmic membranes. Both populations are devoid of NuoL. One population is enzymatically active, while the other is not. The inactive population is missing cluster N2 and is tightly associated with the inducible lysine decarboxylase. This article is part of a Special Issue entitled: Biogenesis/Assembly of Respiratory Enzyme Complexes.

Climate models indicate that global warming will stimulate atmospheric exchange processes and increase rainfall variability, leading to longer dry periods and more intense rainfall events. Recent studies suggest that both the magnitude of the rainfall events and their frequency may be as important for temperate grassland productivity as the annual sum. However, until now interactive effects between land management practice, such as mowing frequency, and rainfall variability on productivity and forage quality have not been studied in detail. Here, we present the data from a field experiment (EVENT II) in which a Central-European grassland was subjected to increased spring rainfall variability (low, intermediate and extreme rainfall variability without any change to the rainfall amount) and increased mowing frequency (four times compared to twice a year). We assessed biomass production, forage quality parameters, root-length and shoot–root ratio. Enhanced spring rainfall variability reduced midsummer productivity and the leaf N and protein concentrations of a target species, but did not exert any long-term effects on biomass production and forage quality in late summer. However, the increased spring rainfall variability reduced aboveground net primary productivity by 15%. More frequent mowing increased productivity in the first year of the study, but decreased productivity at the end of the second year, showing a decline in the potential for overcompensation after a history of more intense mowing. Generally, more frequent mowing decreased the shoot–root ratio and increased the concentration of leaf N. Increased mowing frequency neither buffered, nor amplified the adverse effects of rainfall variability on productivity, but made leaf N concentrations in early summer more responsive to altered rainfall patterns. These results highlight the fact that even relatively small and short-term alterations to rainfall distribution can reduce production and forage quality, with little buffering capacity of altered mowing frequency. Comparisons with productivity data from the first year of the study, in which both, rainfall distribution and rainfall amount were modified, demonstrate the crucial role of sufficient moisture (annual rainfall amount) for grassland resilience: in this first year, negative effects of extreme rainfall variability lasted until the end of the year. To conclude, increased rainfall variability under climate change will likely affect agricultural yield in temperate meadows. Management strategies to buffer these effects have yet to be developed.

The frequency of extreme drought events is projected to increase under global climate change, causing damage to plants and crop yield despite potential acclimation. We investigated whether grasses remain acclimated to drought even after a harvest and remember early summer drought exposure over a whole vegetation period. For this, we compared the response of Arrhenatherum elatius plants under a second, late, drought (they were pre-exposed to an early drought before), to plants exposed to a single, only late, extreme drought. Surprisingly, the percentage of living biomass after a late drought increased for plants that were exposed to drought earlier in the growing season compared to single-stressed plants, even after harvest and resprouting after the first drought. Relative leaf water content did not differ between the two treatments. Net photosynthesis was non-significantly reduced by 25% in recurrent drought treatment. Maximum quantum efficiency ( F v / F m ) and maximum fluorescence ( F m ) were reduced in plants that were exposed to recurrent drought. These findings indicated improved photoprotection in double-stressed plants. Our results provide first hints towards a “drought memory” over an entire vegetation period, even after harvest and resprouting. However, the advantage of improved photoprotection might also cause reductions in photosynthesis that could have adverse effects on crop yield under more severe or longer droughts.