Search

ImportanceMulti-organ impairment associated with Long COVID is a significant burden to individuals, populations and health systems, presenting challenges for diagnosis and care provision. Standardised assessment across multiple organs over time is lacking, particularly in non-hospitalised individuals.ObjectiveTo determine the prevalence of organ impairment in Long COVID patients at 6 and at 12 months after initial symptoms and to explore links to clinical presentation.DesignThis was a prospective, longitudinal study in individuals following recovery from acute COVID-19. We assessed symptoms, health status, and multi-organ tissue characterisation and function, using consensus definitions for single and multi-organ impairment. Physiological and biochemical investigations were performed at baseline on all individuals and those with organ impairment were reassessed, including multi-organ MRI, 6 months later.SettingTwo non-acute settings (Oxford and London).Participants536 individuals (mean 45 years, 73% female, 89% white, 32% healthcare workers, 13% acute COVID-19 hospitalisation) completed baseline assessment (median: 6 months post-COVID-19). 331 (62%) with organ impairment or incidental findings had follow up, with reduced symptom burden from baseline (median number of symptoms: 10 and 3, at 6 and 12 months).ExposureSARS-CoV-2 infection 6 months prior to first assessment.Main outcomePrevalence of single and multi-organ impairment at 6 and 12 months post-COVID-19.ResultsExtreme breathlessness (36% and 30%), cognitive dysfunction (50% and 38%) and poor health-related quality of life (EQ-5D-5LConclusion and RelevanceOrgan impairment was present in 59% of individuals at 6 months post-COVID-19, persisting in 59% of those followed up at 1 year, with implications for symptoms, quality of life and longer-term health, signalling need for prevention and integrated care of Long COVID.Trial RegistrationClinicalTrials.govIdentifier:NCT04369807Key pointsQuestion: What is the prevalence of organ impairment in Long COVID at 6- and 12-months post-COVID-19?Findings: In a prospective study of 536 mainly non-hospitalised individuals, symptom burden decreased, but single organ impairment persisted in 59% at 12 months post-COVID-19.Meaning: Organ impairment in Long COVID has implications for symptoms, quality of life and longer-term health, signalling need for prevention and integrated care of Long COVID.

Key message A total of 45 aquaporins was identified in Fagus sylvatica, 35 of which were differentially expressed in spring and summer in the leaves, phloem and xylem of 11-year-old trees. Abstract European beech (Fagus sylvatica) has been widely studied in terms of its water relations and local adaptation. However, to date, the underlying basis conferring adaptation to differences in water availability are unknown. Therefore, we examined the expression of aquaporins in trees of four different beech provenances representing the southern and northern range margins, as well as core populations, grown in a common garden. We sampled their xylem, phloem and leaf tissue, when leaves had fully expanded, and in late summer. A total of 45 aquaporin isoforms were identified in the beech genome, of which 35 were detected across all sampled tissues. In our phylogenetic analysis, beech aquaporins clustered into the five subfamilies found in other woody species. Members of the plasma membrane intrinsic protein subfamily generally displayed the highest levels of expression, followed by tonoplast intrinsic proteins. Isoforms of the remaining subfamilies, Noduline-26-like intrinsic proteins, small basic intrinsic proteins and uncharacterised intrinsic proteins, were expressed at very low to moderate levels. The expression of most isoforms was stable or declined from spring to summer. Leaves followed a different expression profile from that of vascular tissues, whereas both phloem and xylem were found to express the same FsMIPs. Tissue-specific aquaporin expression was very similar amongst the four beech provenances, indicating that there is no inherent difference in the capability of these provenances to regulate aquaporin activity. The general decrease in FsMIP expression toward the end of the growing period indicates that aquaporins are involved in tree water relations and growth.

Sunflecks are transient patches of direct radiation that provide a substantial proportion of the daily irradiance to leaves in the lower canopy. In this position, faster photosynthetic induction would allow for higher sunfleck-use efficiency, as is commonly reported in the literature. Yet, when sunflecks are too few and far between, it may be more beneficial for shade leaves to prioritize efficient photosynthesis under shade. We investigated the temporal dynamics of photosynthetic induction, recovery under shade, and stomatal movement during a sunfleck, in sun and shade leaves of Fagus sylvatica from three provenances of contrasting origin. We found that shade leaves complete full induction in a shorter time than sun leaves, but that sun leaves respond faster than shade leaves due to their much larger amplitude of induction. The core-range provenance achieved faster stomatal opening in shade leaves, which may allow for better sunfleck-use efficiency in denser canopies and lower canopy positions. Our findings represent a paradigm shift for future research into light fluctuations in canopies, drawing attention to the ubiquitous importance of sunflecks for photosynthesis, not only in lower-canopy leaves where shade is prevalent, but particularly in the upper canopy where longer sunflecks are more common due to canopy openness.

Societal Impact Statement The effective management of light is beneficial for growers of plants in greenhouses, polytunnels and under cloches. The materials and structures used to construct these environments often create light-limited conditions for crops and change the spectral composition of sunlight they receive. Combining practical measures, drawn from knowledge of plant photobiology, allows growers to monitor, forecast and optimise conditions in their growing environment according to its geographical location and the crop grown. Improved management of light through these measures could be expected to improve food quality and yield, and potentially reduce use of energy, water and pesticides. Horticultural production in greenhouses and in polytunnels expands the viable geographic range of many crop species and extends their productive growing season. These semi-controlled growing environments buffer natural fluctuations in heat, cold and light and hold potential to improve food security with a low environmental footprint. Over the last decade, technological advances in cladding materials, smart filters, photo-electric cells for energy production and LED lighting have created opportunities to improve the light environment within these structures. In parallel, there have been large advances in plant photobiology, underpinned by progress in identifying the mechanisms of photomorphogenesis and photoprotection, mediated by plant photoreceptors and their interactions, across regions of the spectrum. However, there remains unexploited potential to synthesise and transfer knowledge from these fields to horticulture, particularly with respect to tailoring the use of sunlight to specific locations and production systems. Here, we systematically explain (1) the value of modelling and monitoring patterns of sunlight to allow for informed design of the growth environment; (2) the means of optimising light conditions through selection of materials and structures; (3) the requirements of different crop plants in terms of the amount and spectral composition of light that will benefit yield and food quality; (4) the potential to combine this knowledge for effective management of the sunlight; and, finally, (5) the additional benefits these actions may bring to growers and society at large, beyond the crops themselves, in terms of water use and energy efficiency.

Evergreen plants growing at high latitudes or high elevations may experience freezing events in their photosynthetic tissues. Freezing events can have physical and physiological effects on the leaves which alter leaf optical properties affecting remote and proximal sensing parameters. We froze leaves of six alpine plant species (Soldanella alpina, Ranunculus kuepferi, Luzula nutans, Gentiana acaulis, Geum montanum, and Centaurea uniflora) and three evergreen forest understorey species (Hepatica nobilis, Fragaria vesca and Oxalis acetosella), and assessed their spectral transmittance and optically measured pigments, as well as photochemical efficiency of photosystem II (PSII) as an indicator of freezing damage. Upon freezing, leaves of all the species transmitted more photosynthetically active radiation (PAR) and some species had increased ultraviolet-A (UV-A) transmittance. These differences were less pronounced in alpine than in understorey species, which may be related to higher chlorophyll degradation, visible as reduced leaf chlorophyll content upon freezing in the latter species. Among these understorey forbs, the thin leaves of O. acetosella displayed the largest reduction in chlorophyll (−79%). This study provides insights into how freezing changes the leaf optical properties of wild plants which could be used to set a baseline for upscaling optical reflectance data from remote sensing. Changes in leaf transmittance may also serve to indicate photosynthetic sufficiency and physiological tolerance of freezing events, but experimental research is required to establish this functional association. Graphical abstract

Adoptive T cell therapy aims to achieve lasting tumour clearance, requiring enhanced engraftment and survival of the immune cells. Cytokines are paramount modulators of T cell survival and proliferation. Cytokine receptors signal via ligand-induced dimerization, and this principle has been hijacked utilising non-native dimerization domains. A major limitation of current technologies resides in the absence of a module that recapitulates the natural cytokine receptor heterodimeric pairing. To circumvent this, we created a new engineered cytokine receptor able to constitutively recreate receptor-heterodimer utilising the heterodimerization domain derived from the IgG1 antibody (dFab_CCR). We found that the signal delivered by the dFab_CCR-IL2 proficiently mimics the cytokine receptor heterodimerization, with transcriptomic signatures similar to that obtained by the activation of IL2 native receptor. Importantly, we found that this dimerization structure is agnostic, efficiently activating signaling through four cytokine receptor families.Using a combination ofin vivoandin vitroscreening approaches, we characterized a library of 18 dFab_CCRs co-expressed with a clinically relevant solid tumor-specific GD2 CAR. Based on this characterization we suggest that the co-expression of either the common β-chain GMCSF or the IL18 dFab_CCRs is optimal to improve CAR T cell expansion, engraftment, and efficacy.Our results demonstrate how the Fab dimerization is efficient and versatile in recapitulating a cytokine receptor heterodimerization signal. This module could be applied for the enhancement of adoptive T cell therapies, and therapies based on other immune cell types. Furthermore, these results provide a choice of cytokine signal to incorporate with adoptive T cells therapies.

Leaf fall in the autumn opens the forest canopy, allowing more solar radiation to be transmitted to the forest floor. Those understorey species that remain physiologically active may benefit from the sunlight received by assimilating additional carbon while conditions remain favourable. We monitored water and leaf pigment content, as well as photosynthetic capacity in six understorey species growing in three adjacent stands differing in their canopy tree species. Leaf fall, transmitted light and microclimate were followed in each stand. We found that leaf fall started earlier in the Betula pendula, than in the Quercus robur stand, and light transmission changed accordingly. Concurrently, understorey leaf senescence was generally earlier in the birch than in the oak stand, itself earlier than in the evergreen Picea abies stand. Neither atmospheric CO , humidity, nor temperature differed between stands. A change in light quality and/or increase in quantity following leaf fall drove the difference in the timing of senescence in the understorey. Species with later senescence were more able to use the increased light after leaf fall. Together these findings help provides a mechanistic foundation to predict how ecosystem functioning and carbon balance will be impacted by phenological shifts in response to global changes.

Climate change is driving many mountain plant species to higher elevations and northern plant species to higher latitudes. However, various biotic or abiotic constraints may restrict any range shift, and one relevant factor for migration to higher elevations could be species’ ability to tolerate high UV-doses. Flavonoids are engaged in photoprotection, but also serve multiple ecological roles. We compared plant optical leaf trait responses of a large set of taxa growing in two botanical gardens (French Alps and southern Finland), considering potential constraints imposed by the relatedness of taxa and the legacy of climatic conditions at plants’ original collection sites. The segregation of optically measured leaf traits along the phylogeny was studied using a published mega-tree GBOTB.extended.tre for vascular plants as a backbone. For a subset of taxa, we investigated the relationship between climatic conditions (namely solar radiation, temperature and precipitation at a coarse scale) at the plants’ original collection site and current trait values. Upon testing the phylogenetic signal (Pagel’s λ), we found a significant difference but intermediate lambda values overall for flavonol or flavone index (Iflav) and anthocyanin index (Iant), indicating that phylogenetic relatedness alone failed to explain the changes in trait values under a Brownian motion model of trait evolution. The local analysis (local indicator of phylogenetic association) indicated mostly positive autocorrelations for Iflav i.e. similarities in optically measured leaf traits, often among species from the same genus. We found significant relationships between climatic variables and leaf chlorophyll index (Ichl), but not Iflav, particularly for annual solar radiation. Changes in plants’ Iflav across microhabitats differing in UV irradiance and predominately high Fv/Fm indicated that most plants studied had sufficient flexibility in photoprotection, conferred by Iflav, to acclimate to contemporary UV irradiances in their environment. While not explaining the mechanisms behind observed trait values, our findings do suggest that some high-elevation taxa display similar leaf flavonoid accumulation responses. These may be phylogenetically constrained and hence moderate plants’ capacity to adjust to new combinations of environmental conditions resulting from climate change.

Remote sensing methods enable detection of solar-induced chlorophyll a fluorescence. However, to unleash the full potential of this signal, intensive cross-disciplinary work is required to harmonize biophysical and ecophysiological studies. For decades, the dynamic nature of chlorophyll a fluorescence (ChlaF) has provided insight into the biophysics and ecophysiology of the light reactions of photosynthesis from the subcellular to leaf scales. Recent advances in remote sensing methods enable detection of ChlaF induced by sunlight across a range of larger scales, from using instruments mounted on towers above plant canopies to Earth-orbiting satellites. This signal is referred to as solar-induced fluorescence (SIF) and its application promises to overcome spatial constraints on studies of photosynthesis, opening new research directions and opportunities in ecology, ecophysiology, biogeochemistry, agriculture and forestry. However, to unleash the full potential of SIF, intensive cross-disciplinary work is required to harmonize these new advances with the rich history of biophysical and ecophysiological studies of ChlaF, fostering the development of next-generation plant physiological and Earth-system models. Here, we introduce the scale-dependent link between SIF and photosynthesis, with an emphasis on seven remaining scientific challenges, and present a roadmap to facilitate future collaborative research towards new applications of SIF.

Background The permeability of plasma membrane aquaporins (PIPs) to small solutes other than water greatly diversifies their potential functions in plant development and metabolic processes. One such process is stress signalling in which hydrogen peroxide (H2O2) plays a major role. Based on transport assays carried out in yeast, there are differences in the degree to which PIPs of Arabidopsis thaliana, are permeable to H2O2 and thus they may differentially facilitate transmembrane diffusion. Here, we test whether specific PIPs aid in the transmembrane diffusion of H2O2 to such an extent that knocking-out PIPs affects plant phenotype. We examined changes in growth and morphology, including biomass accumulation, root system architecture and relative water content, as well as gas exchange, across two H2O2 treatments in knockout mutants of A. thaliana. Results We could infer that PIP-type aquaporins are permeable to H2O2in planta and that this permeability is physiologically relevant in a plant’s response to oxidative stress. In particular, the lack of functional PIP2;3 confers resistance to exogenously applied H2O2 indicating that it facilitates H2O2 entry into root cells. Additionally, PIP1;1 and PIP2;6 were found to facilitate H2O2 diffusion, while PIP2;2 is required for proper root growth under controlled conditions. Main findings We conclude that PIPs are physiologically relevant conduits for H2O2 diffusion in the A. thaliana roots and participate in the regulation of stress responses.

Plasma membrane aquaporin AtPIP2;5 is permeable to CO2 and contributes to mesophyll conductance of CO2 in leaves., The roles of different plasma membrane aquaporins (PIPs) in leaf-level gas exchange of Arabidopsis thaliana were examined using knockout mutants. Since multiple Arabidopsis PIPs are implicated in CO2 transport across cell membranes, we focused on identifying the effects of the knockout mutations on photosynthesis, and whether they are mediated through the control of stomatal conductance of water vapour (gs), mesophyll conductance of CO2 (gm), or both. We grew Arabidopsis plants in low and high humidity environments and found that the contribution of PIPs to gs was larger under low air humidity when the evaporative demand was high, whereas any effect of a lack of PIP function was minimal under higher humidity. The pip2;4 knockout mutant had 44% higher gs than wild-type plants under low humidity, which in turn resulted in an increased net photosynthetic rate (Anet). We also observed a 23% increase in whole-plant transpiration (E) for this knockout mutant. The lack of functional plasma membrane aquaporin AtPIP2;5 did not affect gs or E, but resulted in homeostasis of gm despite changes in humidity, indicating a possible role in regulating CO2 membrane permeability. CO2 transport measurements in yeast expressing AtPIP2;5 confirmed that this aquaporin is indeed permeable to CO2.

Snowmelt in alpine ecosystems brings ample water, and together with above-freezing temperatures, initiates plant growth. In this scenario, rapid activation of photosynthesis is essential for a successful life-history strategy. But, strong solar radiation in late spring enhances the risk of photodamage, particularly before photosynthesis is fully functional. We compared the photoprotective strategy of five alpine forbs: one geophyte not particularly specialised in subnival life (Crocus albiflorus) and four wintergreens differing in their degree of adaptation to subnival life, from least to most specialised: Gentiana acaulis, Geum montanum, Homogyne alpina and Soldanella alpina. We used distance to the edge of snow patches as a proxy to study time-dependent changes after melting. We postulated that the photoprotective response of snowbed specialists would be stronger than of more-generalist alpine meadow species. F-v/F-m was relatively low across wintergreens and even lower in the geophyte C. albiflorus. This species also had the largest xanthophyll-cycle pool and lowest tocopherol and flavonoid glycoside contents. After snow melting, all the species progressively activated ETR, but particularly the intermediate snowbed species G. acaulis and G. montanum. The photoprotective responses after snowmelt were idiosyncratic: G. montanum rapidly accumulated xanthophyll-cycle pigments, tocopherol and flavonoid glycosides; while S. alpina showed the largest increase in plastochromanol-8 and chlorophyll contents and the greatest changes in optical properties. Climate warming scenarios might shift the snowmelt date and consequently alter the effectiveness of photoprotection mechanisms, potentially changing the fitness outcome of the different strategies adopted by alpine forbs.

Background and aim Wherever sunlight reaches litter, there is potential for photodegradation to contribute to decomposition. Although recent studies have weighed the contribution of short wavelength visible and ultraviolet (UV) radiation as drivers of photodegradation, the relative importance of each spectral region across biomes and plant communities remains uncertain. Methods We performed a systematic meta-analysis of studies that assessed photodegradation through spectrally selective attenuation of solar radiation, by synthesizing 30 published studies using field incubations of leaf litter from 110 plant species under ambient sunlight. Results Globally, the full spectrum of sunlight significantly increased litter mass loss by 15.3% ± 1% across all studies compared to darkness. Blue light alone was responsible for most of this increase in mass loss (13.8% ± 1%), whereas neither UV radiation nor its individual constituents UV-B and UV-A radiation had significant effects at the global scale, being only important in specific environments. These waveband-dependent effects were modulated by climate and ecosystem type. Among initial litter traits, carbon content, lignin content, lignin to nitrogen ratio and SLA positively correlated with the rate of photodegradation. Global coverage of biomes and spectral regions was uneven across the meta-analysis potentially biasing the results, but also indicating where research in lacking. Conclusions Across studies attenuating spectral regions of sunlight, our meta-analysis confirms that photodegradation is a significant driver of decomposition, but this effect is highly dependent on the spectral region considered. Blue light was the predominant driver of photodegradation across biomes rather than UV radiation.

Improving public engagement in ecological research improves the visibility of science and educates a wider audience about the value of ecology and its study. To this end, we assess the success of two simple activities, designed to track forest cover and understorey conditions, implemented at Lammi Biological Station Science Trail, Finland, in terms of effective public participation and useability of the data generated. We consider how best to engage participants in the activities, and we validate the data obtained by comparison of its reliability and useability against standard ecological approaches. It is also increasingly timely for researchers to utilise the large datasets that can be generated through effective public engagement. If experiments are effectively designed, these data can provide information at a larger scale than is attainable with the resources typically available to individual research projects. Consequently, given high enough uptake, such activities hold the potential for upscaling or generalisation from their findings. Both activities proved useful to collect more intensive data than would otherwise have been feasible. The quadrat vegetation survey (Activity 1) provided useable data to determine species phenology but not species composition. The canopy disk observations (Activity 2) reliably tracked seasonal changes in canopy cover when calibrated against baseline data. Training in these activities fostered engagement in how climate change affects forest ecology, improving the quality of data collected, and engaging participants eager to learn about and contribute to research into these processes.

Litter decomposition determines carbon (C) backflow to the atmosphere and ecosystem nutrient cycling. Although sunlight provides the indispensable energy for terrestrial biogeochemical processes, the role of photodegradation in decomposition has been relatively neglected in productive mesic ecosystems. To quantify the effects of this variation, we conducted a factorial experiment in the understorey of a temperate deciduous forest and an adjacent gap, using spectral-attenuation-filter treatments. Exposure to the full spectrum of sunlight increased decay rates by nearly 120% and the effect of blue light contributed 75% of this increase. Scaled-up to the whole forest ecosystem, this translates to 13% loss of leaf-litter C through photodegradation over the year of our study for a scenario of 20% gap. Irrespective of the spectral composition, herbaceous and shrub litter lost mass faster than tree litter, with photodegradation contributing the most to surface litter decomposition in forest canopy gaps. Across species, the initial litter lignin and polyphenolic contents predicted photodegradation by blue light and ultraviolet B (UV-B) radiation, respectively. We concluded that photodegradation, modulated by litter quality, is an important driver of decomposition, not just in arid areas, but also in mesic ecosystems such as temperate deciduous forests following gap opening.

Understory plant species take on different functional strategies, whereby some exploit periods of available light in springtime before the canopy closes, and others also benefit from sunlight later in autumn when the canopy opens again. These strategies involve understory species coordinating phenological events to pre-empt canopy leaf out and to extend their growing season beyond canopy leaf senescence, meanwhile accumulating photo-protective pigments which mitigate periods of high-light exposure. Canopy closure brings shade to the understory, but also causes drastic changes in light quality. Whilst many experiments manipulating spectral quality have revealed understory plant responses to the changing R:FR ratio in shade, effect of the blue and UV regions have been examined very little. We installed filters attenuating short wavelength regions of the solar spectrum in a forest understory in southern Finland, creating the following treatments: a transparent control filter, and filters attenuating UV radiation < 350 nm, all UV radiation, and both UV and blue light. In eight understory species, representing different plant functional types, we repeatedly assessed leaf optical properties to obtain epidermal flavonol and anthocyanin contents from leaf emergence in spring to leaf senescence in autumn, during both 2017 and 2018. Flavonols responded more to seasonal changes in light quality in relatively light-demanding species than in shade-tolerant and wintergreen species; and were particularly responsive to blue light. However, anthocyanins were largely unaffected by our filter treatments, suggesting that other cues such as cold temperatures govern their seasonal variation. UV radiation only accelerated leaf senescence in Acer platanoides seedlings, but blue light accelerated leaf senescence in all species measured apart from Quercus robur. In summary, seasonal changes in understory solar radiation in the blue and UV regions affected leaf pigments and leaf phenology; particularly for more light-demanding species. An increase in canopy duration under climate change will extend the period of shade in the understory, with consequences for the spectral cues available to understory plants. The resultant reduction in blue and UV radiation in shade, could delay leaf senescence in the understory even further.

Peripheral T cell lymphomas are typically aggressive with a poor prognosis. Unlike other hematologic malignancies, the lack of target antigens to discriminate healthy from malignant cells has limited the efficacy of immunotherapeutic approaches. The T cell receptor expresses one of two highly homologous chains [T cell receptor β-chain constant (TRBC) domains 1 and 2] in a mutually exclusive manner, making it a promising target. We previously described an antibody with unique TRBC1 specificity (Jovi-1). Here we demonstrate specificity redirection by rational design using structure-guided computational biology to generate a TRBC2-specific antibody (KFN). This permitted the generation of paired reagents (chimeric antigen receptor-T cell) specific for TRBC1 and TRBC2, with preclinical evidence to support their efficacy in T cell malignancies.

Methane production in plant foliage under aerobic conditions remains a cryptic and poorly constrained component of the global methane cycle. While several in-vitro studies reported light-dependent production of methane from plant biomolecules, thus far no studies have investigated methane fluxes at plant shoots during diel cycles. Here, we show that methane emissions from Scots pine shoots follow a distinct diurnal pattern and we demonstrate how these cycles allow estimating an upper limit of shoot methane emissions from ecosystem-atmosphere methane fluxes measured by the eddy covariance method. We present data from three measurement campaigns in forest, garden, and greenhouse settings that quantified methane fluxes of the shoots of Scots pine saplings and adult trees using manual and automated shoot chamber flux measurements systems, two distinct of trace gas analysers (Los Gatos Research UGGA, Picarro G2301). Despite the methodological differences, all campaigns found average methane flux rates between 0.05 and 0.20 nmol g-1 foliar dry weight h-1 in all campaigns. In the garden and greenhouse campaigns, where 24-hour measurement campaigns were possible, shoot methane fluxes exhibited pronounced diurnal cycles with a strong light dependent emission during daytime and low fluxes (mostly below the detection limit) during nighttime. Based on these strong light-dependent diurnal cycles, we were able to calculate an upper limit for shoot methane emissions at the ecosystem level. For this, we quantified the light-dependent and light-independent components of ecosystem-atmosphere methane fluxes measured by eddy covariance, with the light-dependent component tentatively indicating shoot-level methane fluxes. The monthly averages of the so-quantified light-dependent component accounted for 0.0-0.4 nmol methane m-2 sec-1 (range of monthly averages), which corresponds to ~0-1 nmol methane g-1 foliar dry weight h-1. This component is approximately 10-fold higher than shoot-level fluxes, indicating that other processes beside shoot emissions may contribute to light-dependent methane emissions. Nevertheless, even this higher estimate of shoot methane emissions correspond with the low end of the range reported by Keppler et al. (2006; 0.75–55 nmol g-1 d.w. h-1) and fall within the range reported by Fraser et al. (2015; 0.03–2 nmol g-1 d.w. h-1). Taken together, our results show how combining shoot and ecosystem level measurements can help constraining shoot emissions sufficiently for incorporating these fluxes in regional and global methane budgets. Taken together, our results show how combining shoot and ecosystem level measurements can help constraining shoot emissions sufficiently for incorporating these fluxes in regional and global methane budgets.References:Keppler, F., Hamilton, J., Braß, M. et al. Methane emissions from terrestrial plants under aerobic conditions. Nature 439, 187–191 (2006). https://doi.org/10.1038/nature04420Fraser, W. T., Blei, E., Fry, S. C., et al.. Emission of methane, carbon monoxide, carbon dioxide and short-chain hydrocarbons from vegetation foliage under ultraviolet irradiation. Plant, cell & environment, 38(5), 980–989 (2015). https://doi.org/10.1111/pce.12489

Background and aim: Wherever sunlight reaches litter there is potential for photodegradation to contribute to decomposition. Although recent studies have weighted the contribute of the short-wavelength visible spectrum and ultraviolet (UV) radiation as drivers of photodegradation, the relative importance of each spectral region across biomes and plant communities remains uncertain.Methods: We performed a systematic meta-analysis of studies that assessed photodegradation through spectrally selective attenuation of solar radiation, by synthesizing 30 published studies using field incubations of leaf litter from 110 plant species under ambient sunlight.Results: Globally, the full spectrum of sunlight significantly increased litter mass loss by 15.3% ± 1% across all studies compared to darkness. Blue light alone was responsible for most of this increase in mass loss (13.8% ± 1%), whereas neither UV radiation nor its individual constituents UV-B and UV-A radiation had significant effects at the global scale, being only important in specific environments. These waveband-dependent effects were modulated by climate and ecosystem type. Among initial litter traits, carbon content, lignin content, lignin to nitrogen ratio and SLA positively correlated with the rate of photodegradation. Global coverage of biomes and spectral regions was uneven across the meta-analysis potentially biasing the results, but also indicating where research in lacking.Conclusions: Across studies attenuating spectral regions of sunlight, our meta-analysis confirms that photodegradation is a significant driver of decomposition, but this effect is highly dependent on the spectral region considered. Blue light was the predominant driver of photodegradation across biomes rather than UV radiation.

European mountain grasslands are increasingly affected by land-use changes and climate, which have been suggested to exert important controls on grassland carbon (C) and nitrogen (N) pools. However, so far there has been no synthetic study on whether and how land-use changes and climate interactively affect the partitioning of these pools amongst the different grassland compartments. We analyzed the partitioning of C and N pools of 36 European mountain grasslands differing in land-use and climate with respect to above- and belowground phytomass, litter and topsoil (top 23 cm). We found that a reduction of management intensity and the abandonment of hay meadows and pastures increased above-ground phytomass, root mass and litter as well as their respective C and N pools, concurrently decreasing the fractional contribution of the topsoil to the total organic carbon pool. These changes were strongly driven by the cessation of cutting and grazing, a shift in plant functional groups and a related reduction in litter quality. Across all grasslands studied, variation in the impact of land management on the topsoil N pool and C/N-ratio were mainly explained by soil clay content combined with pH. Across the grasslands, below-ground phytomass as well as phytomass- and litter C concentrations were inversely related to the mean annual temperature; furthermore, C/N- ratios of phytomass and litter increased with decreasing mean annual precipitation. Within the topsoil compartment, C concentrations decreased from colder to warmer sites, and increased with increasing precipitation. Climate generally influenced effects of land use on C and N pools mainly through mean annual temperature and less through mean an- nual precipitation. We conclude that site-specific conditions need to be considered for understanding the effects of land use and of current and future climate changes on grassland C and N pools.

The sunlight received by plants is affected by cloudiness and pollution. Future changes in cloud cover will differ among regions, while aerosol concentrations are expected to continue increasing globally as a result of wildfires, fossil fuel combustion, and industrial pollution. Clouds and aerosols increase the diffuse fraction and modify the spectral composition of incident solar radiation, and both will affect photosynthesis and terrestrial ecosystem productivity. Thus, an assessment of how canopy and leaf-level processes respond to these changes is needed as part of accurately forecasting future global carbon assimilation. To review these processes and their implications: first, we discuss the physical basis of the effect of clouds and aerosols on solar radiation as it penetrates the atmosphere; second, we consider how direct and diffuse radiation are absorbed and transmitted by plant canopies and their leaves; and finally, we assess the consequences for photosynthesis at the canopy and ecosystem levels. Photobiology will be affected at the atmospheric level by a shift in spectral composition toward shorter or longer wavelengths under clouds or aerosols, respectively, due to different scattering. Changes in the microclimate and spectral composition of radiation due to an enhanced diffuse fraction also depend on the acclimation of canopy architectural and physiological traits, such as leaf area index, orientation, and clumping. Together with an enhancement of light-use efficiency, this makes the effect of diffuse solar radiation on canopy photosynthesis a multilayered phenomenon, requiring experimental testing to capture those complex interactions that will determine whether it produces the persistent enhancement in carbon assimilation that land-surface models currently predict.

Under field conditions, plants are subject to wind-induced movement which creates fluctuations of light intensity and spectral quality reaching the leaves, defined here as windflecks. Within this study, irradiance within two contrasting wheat (Triticum aestivum) canopies during full sun conditions was measured using a spectroradiometer to determine the frequency, duration and magnitude of low- to high-light events plus the spectral composition during wind-induced movement. Similarly, a static canopy was modelled using three-dimensional reconstruction and ray tracing to determine fleck characteristics without the presence of wind. Corresponding architectural traits were measured manually and in silico including plant height, leaf area and angle plus biomechanical properties. Light intensity can differ up to 40% during a windfleck, with changes occurring on a sub-second scale compared to similar to 5 min in canopies not subject to wind. Features such as a shorter height, more erect leaf stature and having an open structure led to an increased frequency and reduced time interval of light flecks in the CMH79A canopy compared to Paragon. This finding illustrates the potential for architectural traits to be selected to improve the canopy light environment and provides the foundation to further explore the links between plant form and function in crop canopies.

The plant area index (PAI) is a structural trait that succinctly parametrizes the foliage distribution of a canopy and is usually estimated using indirect optical techniques such as digital hemispherical photography. Critically, on-the-ground photographic measurements forgo the vertical variation of canopy structure which regulates the local light environment. Hence new approaches are sought for vertical sampling of traits. We present an uncrewed aircraft system (UAS) spherical photographic method to obtain structural traits throughout the depth of tree canopies. Our method explained 89% of the variation in PAI when compared with ground-based hemispherical photography. When comparing UAS vertical trait profiles with airborne laser scanning data, we found highest agreement in an open birch (Betula pendula/pubescens) canopy. Minor disagreement was found in dense spruce (Picea abies) stands, especially in the lower canopy. Our new method enables easy estimation of the vertical dimension of canopy structural traits in previously inaccessible spaces. The method is affordable and safe and therefore readily usable by plant scientists.

The Montreal Protocol and its Amendments have been highly effective in protecting the stratospheric ozone layer, preventing global increases in solar ultraviolet-B radiation (UV-B; 280-315 nm) at Earth's surface, and reducing global warming. While ongoing and projected changes in UV-B radiation and climate still pose a threat to human health, food security, air and water quality, terrestrial and aquatic ecosystems, and construction materials and fabrics, the Montreal Protocol continues to play a critical role in protecting Earth's inhabitants and ecosystems by addressing many of the United Nations Sustainable Development Goals.

Research indicates that phenolic compounds (e.g. para-coumaric acid) found within pollen grains may be useful as a proxy to reconstruct the UV-B radiation received at the Earth's surface in the geological past. However, application of this method to the plant-fossil record currently relies on a series of untested assumptions surrounding the ecological factors driving the response of pollen grains in the contemporary environment. Here, we investigate the relationship of Pinus spp. pollen to UV-B radiation using individuals of five populations sampled from three elevation gradients across Europe. We develop a novel radiation-modelling approach, which allows us to estimate the UV-B radiation dose of individual trees, weighted by different UV-B action spectra. We then use linear mixed-effects modelling to investigate: (a) whether the variations in UV-B-absorbing compounds in Pinus pollen are best described by models using coarser (subgenus) or finer (population) taxonomic levels; and (b) the duration of the period of accumulation of UV-B-absorbing compounds in pollen, ranging from 8 to 28 days. Our results demonstrate an overall positive relationship between para-coumaric acid and UV-B radiation, best described by applying a UV-B-accumulation period spanning 12–19 days. However, we also show clear evidence for population-level factors influencing this relationship across the study locations. Synthesis. Our multidisciplinary approach, which combines expertise from palaeoecology, plant physiology and atmospheric physics, provides clear evidence that pollen-grain chemistry is subject to population-level variations. We suggest that quantitative reconstructions of long-term changes in springtime UV-B radiation are still achievable using fossil reconstructions, but only with careful consideration of the factors leading to pollen representation in sediments. Future improvements are dependent on mechanistic understanding of the local factors which mediate the UV-B response across different populations, and on upscaling knowledge at the plant level to incorporate longer-term chemical variations represented within sediment samples. publishedVersion

The complexities which beset any attempts to ascribe a foundational ethic to matters of a political stripe are well known, and continue to provoke fierce debate within studies of international rela...

Sunlight is strongly attenuated by the snowpack, causing irradiance to decrease exponentially with depth. The strength of attenuation is wavelength dependent across the spectrum. Changes in received irradiance and its spectral composition are used by plants as cues for the timing of phenology, and it is known that at shallow depths in the snowpack there is sufficient light for plants to photosynthesize if conditions are otherwise favourable. The spectral composition of solar radiation under snow in the visible region was already determined in the 1970s using scanning spectroradiometers, but spectral attenuation within the ultraviolet region (UV-B 280-315 nm, UV-A 315-400 nm) has not been well characterised because it is difficult to measure. We measured vertical transects of spectral irradiance (290-900 nm) transmitted through a settled seasonal snowpack. The peak transmission of radiation was in the UV-A region in the upper centimetres of the snowpack and transmittance generally declined at longer wavelengths. Given the known action spectra of plant photoreceptors, these results illustrate the possibility that changing UV-A:visible and red:far-red radiation ratios under the snowpack may serve as spectral cues for plants; potentially priming plants for the less stable environment they experience following snowmelt. Array spectrometers open opportunities for rapid and continuous measurement of irradiance in challenging environments, e.g. beneath the snowpack, and capturing changing light conditions for plants. Future research is needed to couple the spectral transmittance of snowpacks differing in their longevity and crystal structure with measurements of the perception and response to radiation by plants under snow.

Changes in stratospheric ozone and climate over the past 40-plus years have altered the solar ultraviolet (UV) radiation conditions at the Earth’s surface. Ozone depletion has also contributed to climate change across the Southern Hemisphere. These changes are interacting in complex ways to affect human health, food and water security, and ecosystem services. Many adverse effects of high UV exposure have been avoided thanks to the Montreal Protocol with its Amendments and Adjustments, which have effectively controlled the production and use of ozone-depleting substances. This international treaty has also played an important role in mitigating climate change. Climate change is modifying UV exposure and affecting how people and ecosystems respond to UV; these effects will become more pronounced in the future. The interactions between stratospheric ozone, climate and UV radiation will therefore shift over time; however, the Montreal Protocol will continue to have far-reaching benefits for human well-being and environmental sustainability.

Several recent reviews highlight the molecular mechanisms that underpin phenological responses to temperature and photoperiod; however, these have mostly overlooked the influence of solar radiation and its spectral composition on these processes. For instance, solar radiation in the blue and ultraviolet (UV) regions of the spectrum, as well as the red/far-red (R:FR) ratio, can influence spring and autumn phenology. Solar radiation reaching the Earth changes diurnally and seasonally; however, rising global temperatures, latitudinal range shifts and light pollution are likely to produce novel combinations of phenological cues for tree species. Here, we review the literature on phenological responses to spectral composition. Our objective was to explore the natural variation in spectral composition using radiative transfer models and to reveal any species-specific or ecotype-specific responses relating to latitudinal origin. These responses are likely to be most pronounced at high latitudes where spectral composition varies most throughout the year. For instance, trees from high latitudes tend to be more sensitive to changes in R:FR than those from low latitudes. The effects of blue light and UV radiation on phenology have not been studied as much as those of R:FR, but the limited results available suggest both could be candidate cues affecting autumn leaf colouration and senescence. Failure of more–southern species and ecotypes to adapt and use spectral cues during northwards range shifts could result in mistimed phenology, potentially resulting in frost damage, reduced fitness and limited range expansion. Future areas for research should look to establish how consistently different functional types of tree respond to spectral cues and identify photoreceptor-mediated mechanisms that allow plants to combine information from multiple light cues to coordinate the timing of phenological events. It should then be feasible to consider the synchronous or sequential action of light cues within a hierarchy of environmental factors regulating phenology.

Popular culture is irrevocably implicated in the political constitution of borders, geographical space and identity. Whether this takes the form of re-affirming, or challenging the borders and identities that have reached a hegemonic status will depend, amongst other things, on power, knowledge, subjectivity and ethics. Recently, a monumental struggle has been taking place in the UK over precisely these questions, with a view to deciding the nation-state's future as either situated within or outside the European Union. This article seeks to contribute to the themes briefly outlined here by analysing how the ‘Mac’ cartoons in the Daily Mail newspaper have approached the issue of (im)migration. A central focus will be placed on the ostensible use of metaphor and irony in these cultural items, which are used to constitute contingent concepts as literal and as ‘real’: for instance the UK border, the British identity and the (im)migrant Other identity. Yet more than that, this article seeks to contribute to existing studies on editorial cartoons by drawing attention to how ‘Mac’ not only denigrates the (im)migrant Other identity, but concurrently constitutes the British Self as ‘complacent,’ ‘passive’ ‘ignorant’ and even ‘foolish.’ This is carried out as ‘Mac’ puts forward his case for stronger UK border controls.

Ultraviolet-B radiation (UV-B, 280–315 nm) constitutes less than 1% of the total solar radiation that reaches the Earth's surface but has a disproportional impact on biological and ecological processes from the individual to the ecosystem level. Absorption of UV-B by ozone is also one of the primary heat sources to the stratosphere, so variations in UV-B have important relationships to the Earth's radiation budget. Yet despite its importance for understanding atmospheric and ecological processes, there is limited understanding about the changes in UV-B radiation in the geological past. This is because systematic measurements of total ozone and surface UV-B only exist since the 1970s, so biological or geochemical proxies from sediment archives are needed to reconstruct UV-B irradiance received at the Earth surface beyond the experimental record. Recent developments have shown that the quantification of UV-B-absorbing compounds in pollen and spores have the potential to provide a continuous record of the solar-ultraviolet radiation received by plants. There is increasing interest in developing this proxy in palaeoclimatic and palaeoecological research. However, differences in interpretation exist between palaeoecologists, who are beginning to apply the proxy under various geological settings, and UV-B ecologists, who question whether a causal dose–response relationship of pollen and spore chemistry to UV-B irradiance has really been established. Here, we use a proxy-system modelling approach to systematically assess components of the pollen- and spore-based UV-B-irradiance proxy to ask how these differences can be resolved. We identify key unknowns and uncertainties in making inferences about past UV-B irradiance, from the pollen sensor, the sedimentary archive, and through the laboratory and experimental procedures in order to target priority areas of future work. We argue that an interdisciplinary approach, modifying methods used by plant ecologists studying contemporary responses to solar-UV-B radiation specifically to suit the needs of palaeoecological analyses, provides a way forward in developing the most reliable reconstructions for the UV-B irradiance received by plants across a range of timescales. acceptedVersion

The connection between solar-induced fluorescence (SIF) and vegetation gross primary productivity is being widely investigated across spatial, temporal, and biological scales, including: a) studies at the leaf [1], [2], plant canopy [2]–[4] or satellite pixel scale [5], [6], b) temporally with studies spanning from diurnal [7] to seasonal scales [1], [3], [5], and b) biologically with studies covering various plant functional types (PFTs), e.g., crops [4], [7], deciduous [8] or evergreen forests [1], [3], in response to different sources of stress.

Leaf mass per area (LMA) is a key leaf functional trait correlated with plant strategies dictating morphology, physiology, and biochemistry. Although sunlight is generally accepted as a dominant factor driving LMA, the contribution of each spectral region of sunlight in shaping LMA is poorly understood. In the present study, we grew 11 widespread forb species in a common garden and dissected the traits underpinning differences in LMA, such as its morphological components (leaf density (LD), and leaf thickness (LT)), macroelement and metabolite composition under five spectral-attenuation treatments: (1) transmitting c. 95% of the whole solar spectrum (>?280 nm), (2) attenuating ultraviolet-B radiation (UV-B), (3) attenuating both UV-A and UV-B radiation, (4) attenuating UV radiation and blue light, (5) attenuating UV radiation, blue, and green light. We found that LMA, LD, and chemical traits varied significantly across species depending on spectral treatments. LMA was significantly increased by UV-B radiation and green light, while LD was increased by UV-A but decreased by blue light. LMA positively correlated with LD across treatments but was only weakly related to LT, suggesting that LD was a better determinate of LMA for this specific treatment. Regarding leaf elemental and metabolite composition, carbon, nitrogen, and total phenolics were all positively correlated with LMA, whereas lignin, non-structural carbohydrates, and soluble sugars had negative relationships with LMA. These trends imply a tradeoff between biomass allocation to structural and metabolically functional components. In conclusion, sunlight can spectrally drive LMA mainly through modifying functional and structural support.

BACKGROUND Implementing task specific training is a commonly reported challenge for less experienced therapists. A potential method to improve the ability of recent graduate and student therapists is to upskill regarding task specific training via an online education resource. PURPOSE To evaluate the use and acceptability of the TRAIN program as an online learning resource for physiotherapists. METHODS Data from Google Analytics was sourced to determine use of the program and details about the users. Users of the TRAIN program were also invited to complete two surveys; prior to beginning and upon completion of the program. The surveys collected information about the demographics of the users, perceptions of usefulness of the online resource and overall sentiment. RESULTS Almost 6000 new users interacted with the TRAIN modules during the 15-months study period. The surveys indicated a high level of usability (mean score 9/10, SD 1.5) and clinical utility (mean score 8.8/10, SD 1.6) of the TRAIN program. Perceived knowledge and user confidence in implementing task-specific training was higher for those users completing the post compared to those completing the pre-module survey (knowledge 1.9 and confidence 1.7 out of 10 points higher). Recurring comments in the open-ended feedback pertained to the usefulness, clarity, and ease of use of the TRAIN program. DISCUSSION AND CONCLUSION This study provides preliminary evidence supporting the use and acceptability of the TRAIN program as an online learning resource for physiotherapists. This further contributes to the growing body of literature indicating online learning is generally a well-received teaching tool for physiotherapists.