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Leaf photosynthesis models are used extensively in photosynthesis research and are embedded in many larger scale models. Typical photosynthesis models simplify light intensity as the integrated intensity over the 400-700 nm waveband (photosynthetic active radiation, PAR). However, far-red light (700-750 nm, FR) also drives photosynthesis when supplied in addition to light within the PAR spectrum. Currently, it is unknown how much far-red light contributes to carbon assimilation under various spectral light conditions. We developed a combined experimental and computational method to quantify FR stimulation. Gas-exchange parameters and incident light spectra were measured simultaneously and analysed with wavelength-dependent modelling of light harvesting. Hereto, separate excitation of Photosystem I and Photosystem II was calculated from incident light spectra. The effect of FR supplementation on photosynthesis was subsequently modelled and expressed as a single parameter ρ. We tested our method on Solanum dulcamara, Lactuca sativa and Phaseolus vulgaris under various light conditions. Results show consistent ρ-values across a range of FR levels. Our method provides an approach to consistently quantify the effect of FR stimulation on photosynthesis and harmonise the interpretation of photosynthesis measurements under different light regimes, for example in (experimental) setups with artificial FR supplementation or in canopies., (© 2024 The Author(s). Plant, Cell & Environment published by John Wiley & Sons Ltd.)

Purpose: Patients undergoing cardiothoracic surgery are at risk of developing perioperative stroke, but residual effects of anesthesia may hamper timely detection. This study aims to determine if there is an association between intraoperative regional cerebral oxygenation (ScO 2 ) monitoring using near-infrared spectroscopy (NIRS) and the occurrence of early perioperative stroke within three days after cardiothoracic surgery., Methods: We performed a single-center retrospective observational cohort study including all consecutive cardiothoracic surgery patients with routinely perioperative ScO 2 monitoring admitted postoperatively to the Intensive Care Unit (ICU) between 2008 and 2017. Patients with a confirmed stroke in the anterior cerebral circulation on brain imaging were included in the analysis. Intraoperative area under the curve (AUC), duration, and total ScO 2 excursions below predefined thresholds (< 50% ScO 2 or > 20% reduction below baseline) were calculated for each hemisphere. Stroke-affected and non-affected hemispheres were compared using logistic regression analyses to investigate a potential association between ScO 2 values and stroke., Results: Of the 2454 cardiothoracic surgery patients with perioperative ScO 2 monitoring, 39 had a anterior stroke on brain imaging. ScO 2 readings of 44 affected hemispheres were compared to 34 non-affected hemispheres. Only the duration of ScO 2  < 50% or a > 20% drop from baseline were significantly associated with global ischemia (OR 1.30 (0.95%CI; 1.09-2.30)) when comparing affected (72 [5 to 33] min.) versus non-affected (28 [4 to 44] min.) hemispheres., Conclusion: The duration of ScO 2 values < 50% or a drop > 20% from baseline were associated with the occurrence of early perioperative global cerebral ischemia within three days after cardiothoracic surgery., Competing Interests: Declarations. Conflict of interest: TWLS received research grants and honoraria from Edwards Lifesciences (Irvine, CA, USA) and Masimo Inc. (Irvine, CA, USA) for consulting and lecturing (all payments made to the institution). TWLS is currently working as Senior Medical Director for Edwards Lifesciences (Garching, Germany). Ethical approval: Ethical approval was obtained from the Medical Ethics Committee of the University Medical Center Groningen (METc 2014/154), Groningen, The Netherlands. The Medical Ethics Committee waived the need for written patient consent., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Plants growing at high densities can detect competitors through changes in the composition of light reflected by neighbours. In response to this far-red-enriched light, plants elicit adaptive shade avoidance responses for light capture, but these need to be balanced against other input signals, such as nutrient availability. Here, we investigated how Arabidopsis integrates shade and nitrate signalling. We unveiled that nitrate modulates shade avoidance via a previously unknown shade response pathway that involves root-derived trans-zeatin (tZ) signal and the BEE1 transcription factor as an integrator of light and cytokinin signalling. Under nitrate-sufficient conditions, tZ promotes hypocotyl elongation specifically in the presence of supplemental far-red light. This occurs via PIF transcription factors-dependent inhibition of type-A ARRs cytokinin response inhibitors. Our data thus reveal how plants co-regulate responses to shade cues with root-derived information about nutrient availability, and how they restrict responses to this information to specific light conditions in the shoot., (© 2024. The Author(s).)

Background: High and increasing expenses on pembrolizumab ask for more cost-effective and sustainable treatment strategies to improve affordability of healthcare. Therefore, a part of the Dutch hospitals implemented an alternative, partially lower, weight-based dosing protocol for pembrolizumab. This provided the unique opportunity to compare the overall survival (OS) of the alternative pembrolizumab dosing protocol to standard dosing using a nationwide registry in non-small cell lung cancer (NSCLC) patients., Methods: This is a retrospective cohort study with a non-inferiority primary objective. Forty hospitals in the Dutch Medication Audit and Dutch Lung Cancer Audit treated 1966 patients with NSCLC with first line pembrolizumab (mono- or combination therapy) between Jan 1st 2021, and Mar 31st, 2023. Alternative weight-based pembrolizumab dosing (100/150/200 mg Q3W or 200/300/400 mg Q6W) was administered to 604 patients, and 1362 patients received standard pembrolizumab dosing (200 mg Q3W or 400 mg Q6W). A Cox proportional hazard model with selected covariates was used to compare the OS between alternative and standard dosing protocols. The non-inferiority margin was set at a hazard ratio (HR) of 1.2 for OS. Non-inferiority is established by showing that the upper limit of the 95 % confidence interval (CI) of the HR of OS is smaller or equal to 1.2., Results: Distribution of age (66.7 years +/-9.4), sex (45 % female) and treatment combinations were similar for both groups, comorbidity score was higher in the standard group. Median daily dose in the alternative dosing group was 22 % lower compared to the standard dosing group, 7.14 mg/day (interquartile range (IQR):5.48-8.04 mg/day) vs. 9.15 mg/day (IQR:8.33-9.52 mg/day), respectively. Alternative dosing was non-inferior to standard dosing regarding overall survival (adjusted HR 0.83, 95 %CI:0.69-1.003)., Conclusion: This large, retrospective real-world analysis supports the hypothesis that the alternative, partially lower pembrolizumab dosing protocol in NSCLC maintains treatment effectiveness while reducing treatment costs., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Ruben Malmberg has received payment for lectures from BMS. Roelof van Leeuwen has received grants from BMS and Pfizer, consulting fees from BMS, MDS, Pfizer, Pierre Fabre, AstraZeneca, and Roche, and payment for presentations and attending meetings from AstraZeneca. Hans Smit is a member on the advisory board of BMS and MSD and is a member representative of the Dutch scientific committee for pulmonary disease (no payments involved). Juliëtte Zwaveling has received a grant from AstraZeneca. All other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper]., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

In this study, we explore the interplay between the plant hormones gibberellins (GA), brassinosteroids (BR), and Indole-3-Acetic Acid (IAA) in their collective impact on plant shade avoidance elongation under varying light conditions. We focus particularly on low Red:Far-red (R:FR) light conditions achieved by supplementing the background light with FR. We characterized the tomato internode response to low R:FR and, with RNA-seq analysis, we were able to identify some of the potential regulatory hormonal pathways. Through a series of exogenous pharmacological modulations of GA, IAA, and BR, we demonstrate that GA and BR are sufficient but also necessary for inducing stem elongation under low R:FR light conditions. Intriguingly, while IAA alone shows limited effects, its combination with GA yields significant elongation, suggesting a nuanced hormonal balance. Furthermore, we unveil the complex interplay of these hormones under light with low R:FR, where the suppression of one hormone's effect can be compensated by the others. This study provides insights into the hormonal mechanisms governing plant adaptation to light, highlighting the intricate and adaptable nature of plant growth responses. Our findings have far-reaching implications for agricultural practices, offering potential strategies for optimizing plant growth and productivity in various lighting environments., (© 2024 The Author(s). Physiologia Plantarum published by John Wiley & Sons Ltd on behalf of Scandinavian Plant Physiology Society.)

Plants use light as a resource and signal. Photons within the 400-700 nm waveband are considered photosynthetically active. Far-red photons (FR, 700-800 nm) are used by plants to detect nearby vegetation and elicit the shade avoidance syndrome. In addition, FR photons have also been shown to contribute to photosynthesis, but knowledge about these dual effects remains scarce. Here, we study shoot-architectural and photosynthetic responses to supplemental FR light during the photoperiod in several rice varieties. We observed that FR enrichment only mildly affected the rice transcriptome and shoot architecture as compared to established model species, whereas leaf formation, tillering and biomass accumulation were clearly promoted. Consistent with this growth promotion, we found that CO 2 -fixation in supplemental FR was strongly enhanced, especially in plants acclimated to FR-enriched conditions as compared to control conditions. This growth promotion dominates the effects of FR photons on shoot development and architecture. When substituting FR enrichment with an end-of-day FR pulse, this prevented photosynthesis-promoting effects and elicited shade avoidance responses. We conclude that FR photons can have a dual role, where effects depend on the environmental context: in addition to being an environmental signal, they are also a potent source of harvestable energy., (© 2024 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.)

Plant organs move throughout the diurnal cycle, changing leaf and petiole positions to balance light capture, leaf temperature, and water loss under dynamic environmental conditions. Upward movement of the petiole, called hyponasty, is one of several traits of the shade avoidance syndrome (SAS). SAS traits are elicited upon perception of vegetation shade signals such as far-red light (FR) and improve light capture in dense vegetation. Monitoring plant movement at a high temporal resolution allows studying functionality and molecular regulation of hyponasty. However, high temporal resolution imaging solutions are often very expensive, making this unavailable to many researchers. Here, we present a modular and low-cost imaging setup, based on small Raspberry Pi computers that can track leaf movements and elongation growth with high temporal resolution. We also developed an open-source, semiautomated image analysis pipeline. Using this setup, we followed responses to FR enrichment, light intensity, and their interactions. Tracking both elongation and the angle of the petiole, lamina, and entire leaf in Arabidopsis (Arabidopsis thaliana) revealed insight into R:FR sensitivities of leaf growth and movement dynamics and the interactions of R:FR with background light intensity. The detailed imaging options of this system allowed us to identify spatially separate bending points for petiole and lamina positioning of the leaf., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists.)

Plants growing in dense vegetation stands need to flexibly position their photosynthetic organs to ensure optimal light capture in a competitive environment. They do so through a suite of developmental responses referred to as the shade avoidance syndrome. Belowground, root development is also adjusted in response to aboveground neighbour proximity. Canopies are dynamic and complex environments with heterogenous light cues in the far-red, red, blue and UV spectrum, which can be perceived with photoreceptors by spatially separated plant tissues. Molecular regulation of plant architecture adjustment via PHYTOCHROME-INTERACTING FACTOR (PIF) transcription factors and growth-related hormones such as auxin, gibberellic acid, brassinosteroids and abscisic acid were historically studied without much attention to spatial or tissue-specific context. Recent developments and technologies have, however, sparked strong interest in spatially explicit understanding of shade avoidance regulation. Other environmental factors such as temperature and nutrient availability interact with the molecular shade avoidance regulation network, often depending on the spatial location of the signals, and the responding organs. Here, we aim to review recent advances in how plants respond to heterogenous light cues and integrate these with other environmental signals., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology.)

Plants detect their neighbors via various cues, including reflected light and touching of leaf tips, which elicit upward leaf movement (hyponasty). It is currently unknown how touch is sensed and how the signal is transferred from the leaf tip to the petiole base that drives hyponasty. Here, we show that touch-induced hyponasty involves a signal transduction pathway that is distinct from light-mediated hyponasty. We found that mechanostimulation of the leaf tip upon touching causes cytosolic calcium ([Ca 2+ ] cyt induction in leaf tip trichomes that spreads towards the petiole. Both perturbation of the calcium response and the absence of trichomes reduce touch-induced hyponasty. Finally, using plant competition assays, we show that touch-induced hyponasty is adaptive in dense stands of Arabidopsis. We thus establish a novel, adaptive mechanism regulating hyponastic leaf movement in response to mechanostimulation by neighbors in dense vegetation., (© 2023. Springer Nature Limited.)

A new study draws attention to photosynthetically produced sucrose as a major shoot-derived and auxin-dependent regulator of root growth and development in plants., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Stroke is a feared complication after cardiothoracic surgery, with an incidence of around 2 to 3%. Anaesthesia and postoperative sedation may obscure clinical symptoms of stroke and thus delay diagnosis and timely intervention., Objectives: The objective was to assess the value of intra-operative neuromonitoring and blood pressure monitoring for predicting the occurrence of peri-operative stroke within 3 days after cardiothoracic surgery., Design: Single-centre retrospective observational cohort study., Setting: Academic tertiary care medical centre., Patients: All consecutive patients with cardiothoracic surgery and intra-operative neuromonitoring admitted postoperatively to the Intensive Care Unit (ICU) between 2008 and 2017., Main Outcome Measures: The primary endpoint was the occurrence of any stroke confirmed by brain imaging within 3 days postcardiothoracic surgery. Areas under the curve (AUC) of intra-operative mean arterial pressure (MAP), cerebral oxygen saturation (ScO 2 ) and bispectral index (BIS) below predefined thresholds were calculated, and the association with early stroke was tested using logistic regression analyses., Results: A total of 2454 patients admitted to the ICU after cardiothoracic surgery had complete intra-operative data for ScO 2 , BIS and MAP and were included in the analysis. In 58 patients (2.4%), a stroke was confirmed. In univariate analysis, a larger AUC MAP<60 mmHg [odds ratio (OR) 1.43; 95% confidence interval (CI), 1.21 to 1.68) and larger AUC BIS<25 (OR 1.51; 95% CI, 1.24 to 1.83) were associated with the occurrence of postoperative stroke while ScO 2 less than 50% or greater than 20% reduction from individual baseline was not (OR 0.91; 95% CI, 0.50 to 1.67). After multivariable analysis, AUC BIS<25 (OR 1.45; 95% CI, 1.12 to 1.87) and longer duration of MAP less than 60 mmHg (OR 1.52; 95% CI, 1.02 to 2.27) remained independently associated with stroke occurrence., Conclusion: Cumulative intra-operative BIS values below 25 and longer duration of MAP below 60 mmHg were associated with the occurrence of peri-operative stroke within 3 days after cardiothoracic surgery. Prospective studies are warranted to evaluate a causal relationship between low BIS and stroke to establish whether avoiding intra-operative BIS values below 25 might reduce the incidence of peri-operative stroke., (Copyright © 2023 European Society of Anaesthesiology and Intensive Care. Unauthorized reproduction of this article is prohibited.)

Although plants are immobile, many of their organs are flexible to move in response to environmental cues. In dense vegetation, plants detect neighbors through far-red light perception with their leaf tip. They respond remotely, with asymmetrical growth between the abaxial and adaxial sides of the leafstalk, the petiole. This results in upward movement that brings the leaf blades into better lit zones of the canopy. The plant hormone auxin is required for this response, but it is not understood how non-differential leaf tip-derived auxin can remotely regulate movement. Here, we show that remote signaling of far-red light promotes auxin accumulation in the abaxial petiole. This local auxin accumulation is facilitated by reinforcing an intrinsic directionality of the auxin transport protein PIN3 on the petiole endodermis, as visualized with a PIN3-GFP line. Using an auxin biosensor, we show that auxin accumulates in all cell layers from endodermis to epidermis in the abaxial petiole, upon far-red light signaling in the remote leaf tip. In the petiole, auxin elicits a response to both auxin itself as well as a second growth promoter; gibberellin. We show that this dual regulation is necessary for hyponastic leaf movement in response to light. Our data indicate that gibberellin is required to permit cell growth, whereas differential auxin accumulation determines which cells can grow. Our results reveal how plants can spatially relay information about neighbor proximity from their sensory leaf tips to the petiole base, thus driving adaptive growth., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Blood service organizations employ various ways to ensure transfusion blood safety, including the testing of all donations for transfusion-transmissible infections (TTI) and the exclusion of donors who are at increased risk of a recent infection. As some TTIs are more common among men who have sex with men (MSM), many jurisdictions (temporarily) defer the donation of blood by sexually active MSM. This boils down to a categorical exclusion of a large group solely on the basis of their sexual orientation, which is seen as unduly discriminatory and stigmatizing. Blood service organizations in the U.K. and the Netherlands have recently changed their deferral policies for MSM. The problem of the MSM deferral involves a conflict between fundamental rights: the right of MSM to equal treatment and the right to health of the recipients of blood and blood products. We distinguish and discuss three broad alternative options to the current categorical deferral of MSM donations: (1) completely abandoning donor selection on the basis of sexual behavior, (2) individual risk assessment of the sexual activities of each potential donor, and (3) individual risk assessment of the sexual activities of MSM only. The new U.K. policy falls within the second category, and the new Dutch policy is in the third category. We argue that each approach comes with moral costs but that the most reasonable option is different from the policies of both the U.K. and the Netherlands., (© 2022 The Authors. Bioethics published by John Wiley & Sons Ltd.)

Objective: The authors aimed to study the association between postoperative atrial fibrillation (POAF) and thromboembolic stroke and to determine risk factors for thromboembolic stroke after cardiac surgery., Design: The authors performed a secondary analysis from a randomized controlled trial (GRIP-COMPASS). The patients with thromboembolic stroke were compared with those without thromboembolic stroke, and the difference in the incidence of POAF between these groups was assessed. Odds ratios (OR) were calculated using logistic regression analyses. Brain imaging was studied for the occurrence of thromboembolic stroke during hospital admission, and POAF was monitored for seven days. To assess which characteristics were associated with occurrence of thromboembolic stroke, stepwise backward regression analysis was performed., Participants: All adult consecutive cardiac surgery patients admitted postoperatively to the intensive care unit., Setting: Academic tertiary care medical center., Interventions: None., Measurements and Main Results: Of the 910 patients included in this study, 26 patients (2.9%) had a thromboembolic stroke during hospital admission. The incidence of POAF during the first seven days after cardiac surgery in those with thromboembolic stroke was 65%, compared with 39% in those without thromboembolic stroke: adjusted OR 3.01 (95% confidence interval, 1.13-8.00). POAF, a history of peripheral vascular disease, a higher EuroSCORE, and a longer duration of surgery were associated with thromboembolic stroke., Conclusions: POAF within seven days after cardiac surgery was associated with a three-fold increased risk for a thromboembolic stroke during hospital admission. Expeditious treatment of POAF may, therefore, reduce early stroke risk after cardiac surgery., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)