How to analyse plant phenotypic plasticity in response to a changing climate

Plant biology is experiencing a renewed interest in the mechanistic underpinnings and evolution of phenotypic plasticity that calls for a re‐evaluation of how we analyse phenotypic responses to a rapidly changing climate. We suggest that dissecting plant plasticity in response to increasing temperature needs an approach that can represent plasticity over multiple environments, and considers both population‐level responses and the variation between genotypes in their response. Here, we outline how a random regression mixed model framework can be applied to plastic traits that show linear or nonlinear responses to temperature. Random regressions provide a powerful and efficient means of characterising plasticity and its variation. Although they have been used widely in other fields, they have only recently been implemented in plant evolutionary ecology. We outline their structure and provide an example tutorial of their implementation.This research was supported by the Australian Research Council (DP170101681)

Wolbachia-mediated antiviral protection in Drosophila larvae and adults following oral infection

Understanding viral dynamics in arthropods is of great importance when designing models to describe how viral spread can influence arthropod populations. The endosymbiotic bacterium Wolbachia spp., which is present in up to 40% of all insect species, has the ability to alter viral dynamics in both Drosophila spp. and mosquitoes, a feature that in mosquitoes may be utilized to limit spread of important arboviruses. To understand the potential effect of Wolbachia on viral dynamics in nature, it is important to consider the impact of natural routes of virus infection on Wolbachia antiviral effects. Using adult Drosophila strains, we show here that Drosophila-Wolbachia associations that have previously been shown to confer antiviral protection following systemic viral infection also confer protection against virus-induced mortality following oral exposure to Drosophila C virus in adults. Interestingly, a different pattern was observed when the same fly lines were challenged with the virus when still larvae. Analysis of the four Drosophila-Wolbachia associations that were protective in adults indicated that only the w1118-wMelPop association conferred protection in larvae following oral delivery of the virus. Analysis of Wolbachia density using quantitative PCR (qPCR) showed that a high Wolbachia density was congruent with antiviral protection in both adults and larvae. This study indicates that Wolbachia-mediated protection may vary between larval and adult stages of a given Wolbachia-host combination and that the variations in susceptibility by life stage correspond with Wolbachia density. The differences in the outcome of virus infection are likely to influence viral dynamics in Wolbachia-infected insect populations in nature and could also have important implications for the transmission of arboviruses in mosquito populations

Effects of warming temperatures on germination responses and trade-offs between seed traits in an alpine plant

1. Climate warming may affect multiple aspects of plant life history, including important factors such as germination responses and the key trade-off between offspring size and number. As a case study to address these concepts, we used an alpine plant (waxy bluebell, Wahlenbergia ceracea; Campanulaceae) that shows plasticity to warming in seed traits and in which seed dormancy status regulates germination. We chose an alpine species because alpine environments are ecosystems particularly under threat by climate change. 2. We conducted germination assays under cool and warm temperatures using seeds produced by individuals that were grown under historical (cooler) and future (warmer) temperature scenarios. We assessed the presence of a seed size vs number trade-off, and then examined the effects of seed number and size on germination percentage, the fractions of dormant and viable seeds, and germination velocity. Further, we examined whether warming during parental growth and during germination affected these relationships. 3. We found evidence for a seed size vs number trade-off only under historical parental temperatures. Indeed, under future growth temperatures, parental plants produced fewer and smaller seeds and there was no evidence of a trade-off. However, the reductions in both seed traits under warming did not affect germination, despite correlations of seed size and number with germination traits. Warming increased germination, particularly of larger seeds, but overall it resulted in more than fourfold reductions in parental fitness. 4. Synthesis. Our study shows the importance of growth conditions when evaluating the seed size vs number trade-off. Stressful conditions, such as warmer temperatures, can restrain the ability of plants to reach optimal investment in reproduction, masking the trade-off. By analysing responses across the whole life cycle, we show here an overall detrimental effect of warming, highlighting the potential risk of climate change for W. ceracea, and, potentially, for alpine plant communities more widely.Files can be opened using Excel and analysed using R.Funding provided by: Australian Research CouncilCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100000923Award Number: DP170101681Experiments were conducted using the plant species Wahlnebrgia ceracea (waxy bluebells). Two datasets were used in this manuscript. 1) Seed size vs number trade-off: Parental individuals from a total of 30 lines ('Line') were grown in growth chambers for 191 days under temperature conditions of a historical/cooler (1960–1970) or a projected future/warmer (2090–2100) climate ('Parental_Temperature'). The parental individuals were randomly assigned to one of three blocks, which corresponded to positions inside the chambers, and each block was equivalent in all chambers ('Block'). Day and night temperatures during the experiment were changed every 15 days to mimic seasonality, with the maximum day temperatures during the peak of summer being 24°C and 29°C for the historical and future parental temperatures, respectively. After 100 days since the imposition of the temperature treatments (during the peak of the summer), half of the plants were moved for 5 days to new chambers, where the temperature was 5°C above the respective treatments, i.e., 29°C and 34°C ('Heatwave'). After this time, the parental individuals were moved back to their respective historical or future temperature treatments. We collected the seeds throughout the 191 days of parental growth, and we stored them in desiccators for at least 11 weeks. After this time, we calculated seed size ('Seed_Size') as the average mass of three lots of 50 seeds divided by 50. We calculated seed number ('Seed_Number') as the ratio between the cumulative mass of the seeds produced by each parental individual and seed size. The 30 lines of the parental individuals were obtained by crossing plants that originated from seeds that were collected at the same elevation, either high or low elevation ('Elevation') in sites within Kosciuszko National Park, NSW, Australia. Therefore, 14 lines originated from high elevations and 14 lines from low elevations. 2) Germination responses - seed traits correlations: The seeds were harvested from the parental individuals grown under historical/cooler or projected future/warmer temperatures ('Parental_Temperature') (see above) from a subset of 14 lines ('Line'). These seeds were used in germination assays in the glasshouse under cool (25°C) or warm temperatures (30°C) ('Germination_Temperature'). We measured seed size ('Seed_Size') as the average mass of three lots of 50 seeds; then these seeds were sowed in agar dishes (25 seeds per dish, 2 dishes per temperature treatment from each parental individual). Seed number ('Seed_Number') was the same as above. Dishes were left under temperature treatments for 4 weeks to allow germination of the non-dormant fraction of the seeds ('Not_Dormant_Seeds') and germination was checked once per week. Then, all the dishes were moved to a cold room at 4–5°C in the dark for 4 weeks to allow cold stratification. After this time, dishes were moved back to the glasshouse under the same temperature treatments as before to allow germination of the dormant seeds. We considered seeds to be dormant ('Dormant_seeds') if they germinated during or after cold stratification or if they did not germinate at all but were still determined to be viable at the end of the experiment. We considered seed to be viable ('Viable_Seeds') if they germinated ('Germinated_Seeds') as well as the seeds that contained an endosperm but still did not germinate ('Not_Germinated_Seeds'), while we considered empty seeds as non-viable ('Not_Viable_Seeds'). Germinated and not germinated seeds (as above) were used to calculate the germination percentage. We calculated germination velocity ('Germination_Velocity') as the reciprocal of the mean germination time (germination velocity (germination (%) week-1) GV = (G1 + G2 +…+ Gn) / (G1 x T1 + G2 x T2 +…+ Gn x Tn), where Gn is the number of new germinating seeds at each sampling point, and Tn is the time between each sampling point (= one week). The files provided present the datasets in their first sheet and keys with the definitions of each term in the second sheet

Tolerance of warmer temperatures does not confer resilience to heatwaves in an Alpine herb

Climate change is generating both sustained trends in average temperatures and higher frequency and intensity of extreme events. This poses a serious threat to biodiversity, especially in vulnerable environments, like alpine systems. Phenotypic plasticity is considered to be an adaptive mechanism to cope with climate change in situ, yet studies of the plastic responses of alpine plants to high temperature stress are scarce. Future weather extremes will occur against a background of warmer temperatures, but we do not know whether acclimation to warmer average temperatures confers tolerance to extreme heatwaves. Nor do we know whether populations on an elevational gradient differ in their tolerance or plasticity in response to warming and heatwave events. We investigated the responses of a suite of functional traits of an endemic Australian alpine herb, Wahlenbergia ceracea, to combinations of predicted future (warmer) temperatures and (relative) heatwaves. We also tested whether responses differed between high- vs. low-elevation populations. When grown under warmer temperatures, W. ceracea plants showed signs of acclimation by means of higher thermal tolerance (Tcrit, T50, and Tmax). They also invested more in flower production, despite showing a concurrent reduction in photosynthetic efficiency (Fv/Fm) and suppression of seed production. Heatwaves reduced both photosynthetic efficiency and longevity. However, we found no evidence that acclimation to warmer temperatures conferred tolerance of the photosynthetic machinery to heatwaves. Instead, when exposed to heatwaves following warmer growth temperatures, plants had lower photosynthetic efficiency and underwent a severe reduction in seed production. High- and low-elevation populations and families exhibited limited genetic variation in trait means and plasticity in response to temperature. We conclude that W. ceracea shows some capacity to acclimate to warming conditions but there is no evidence that tolerance of warmer temperatures confers any resilience to heatwaves.This research was supported by the Australian Research Council (DP170101681), an International Ph.D. Scholarship to RN and an ARC Future Fellowship FT110100453 to LK. Research grants funded all research related costs (such as renting growth chambers or buying equipment), while the scholarship paid a stipend to RN

学習塾の原点を見つめ直す : 学習塾の存在意義とは

Background: Biosimilars are medicinal products that are similar to a biopharmaceutical that has already been authorised. As biopharmaceuticals are expected to dominate the best-selling pharmaceuticals worldwide by 2016, the emergence of biosimilars imposes an important challenge for governments. At this moment, the uptake of biosimilars in Belgium is limited, with market shares close to 0 %. Objective: This study aimed to identify the barriers that impede the uptake of biosimilars in Belgium. Methods: Semi-structured interviews were conducted to investigate in depth the barriers to the uptake of biosimilars in Belgium. Respondents were selected through selective sampling so that all different stakeholders were represented (authorities, physicians, pharmacists, patients, academics and industry). Respondents were contacted by e-mail and letter with a request for participation. A thematic framework was used to analyze the data. Results: Three main barriers to the uptake of biosimilars in the Belgian market were identified: a lack of confidence towards biosimilars by some stakeholders; uncertaint

Body Image and Cosmesis after Percutaneous Transforaminal Endoscopic Discectomy versus Conventional Open Microdiscectomy for Sciatica

Study Design: Randomized controlled trial Objective: Percutaneous transforaminal endoscopic discectomy (PTED) was introduced as a less invasive procedure to treat sciatica. Even though the PTED has a small scar size, it is unknown if PTED also leads to better scar-related patient-reported outcomes. Therefore, we aimed to compare scar-related outcomes between patients undergoing PTED vs open microdiscectomy. Methods: Patients with at least 6 weeks of radiating leg pain were randomized in a 1:1 ratio to PTED or open microdiscectomy. Scar-related patient-reported outcomes were measured using the Body Image Score (BIS), Cosmesis Scale (CS) and a 0-10 numeric rating scale (NRS) on scar esthetic. Results: Of the 530 included patients, 286 patients underwent PTED and 244 underwent open microdiscectomy as allocated. At 12 months of follow-up, 95% of the patients had data available. At 12 months, the BIS was 6.2 ± 1.7 in the PTED-group and 6.6 ± 1.9 in the open microdiscectomy group (between-group difference.4, 95% CI.2 to.7). CS was 21.3 ± 3.0 in the PTED-group and 18.6 ± 3.4 in the open microdiscectomy group (between-group difference −2.7, 95% CI −3.1 to −2.3). Average NRS for scar esthetic was 9.2 ± 1.3 and 7.8 ± 1.6 in the PTED and open microdiscectomy groups, respectively (between-group difference −1.4, 95% CI −1.6 to −1.2) Conclusions: PTED leads to a higher self-rated scar esthetic as compared to open microdiscectomy, while self-reported body image seems to be comparable between both groups. Therefore, from an esthetic point, PTED seems to be the preferred technique to treat sciatica.</p