Environmental Light Conditions Research Articles

A Multi-Step Image Pre-Enhancement Strategy for a Fish Feeding Behavior Analysis Using Efficientnet

To enhance the accuracy of lightweight CNN classification models in analyzing fish feeding behavior, this paper addresses the image quality issues caused by external environmental factors and lighting conditions, such as low contrast and uneven illumination, by proposing a Multi-step Image Pre-enhancement Strategy (MIPS). This strategy includes three critical steps: initially, images undergo a preliminary processing using the Multi-Scale Retinex with Color Restoration (MSRCR) algorithm, effectively reducing the impact of water surface reflections and enhancing the visual effect of the images; secondly, the Multi-Metric-Driven Contrast Limited Adaptive Histogram Equalization (mdc) technique is applied to further improve image contrast, especially in areas of low contrast, by adjusting the local contrast levels to enhance the clarity of the image details; finally, Unsharp Masking (UM) technology is employed to sharpen the images, emphasizing their edges to increase the clarity of the image details, thereby significantly improving the overall image quality. Experimental results on a custom dataset have confirmed that this pre-enhancement strategy significantly boosts the accuracy of various CNN-based classification models, particularly for lightweight CNN models, and drastically reduces the time required for model training compared to the use of advanced ResNet models. This research provides an effective technical route for improving the accuracy and efficiency of an image-based analysis of fish feeding behavior in complex environments.

Digest: How environmental light conditions shape the evolution of visual systems in birds.

How do varying environmental light conditions influence the evolution of avian visual systems? Fröhlich et al. (2024) demonstrate that nocturnal birds evolved broader corneas and slightly longer axial lengths than their diurnal counterparts, increasing light capture efficiency. Nocturnal species also tended to maintain or reduce the size of brain regions responsible for vision, i.e., the optic tectum and the visual wulst. These results highlight adaptive trends in nocturnal species, where evolutionary improvement in low-light performance of eyes may be accompanied by compromised brain function.

The function and consequences of fluorescence in tetrapods

Fluorescence, the optical phenomenon whereby short-wavelength light is absorbed and emitted at longer wavelengths, has been widely described in aquatic habitats, in both invertebrates and fish. Recent years have seen a stream of articles reporting fluorescence, ranging from frogs, platypus, to even fully terrestrial organisms such as flying squirrels, often explicitly or implicitly linking the presence of fluorescence with sexual selection and communication. However, many of these studies fail to consider the physiological requirements of evolutionary stable signaling systems, the environmental dependence of perception, or the possible adaptive role of fluorescent coloration in a noncommunicative context. More importantly, the idea that fluorescence may simply constitute an indirect by-product of selection on other traits is often not explored. This is especially true for terrestrial systems where environmental light conditions are often not amenable for fluorescent signaling in contrast to, for example, aquatic habitats in which spectral properties of water promote functional roles for fluorescence. Despite the appeal of previously unknown ways in which coloration may drive evolution, the investigation of a putative role of fluorescence in communication must be tempered by a realistic understanding of its limitations. Here, we not only highlight and discuss the key body of literature but also address the potential pitfalls when reporting fluorescence and how to solve them. In addition, we propose exciting different research avenues to advance the field of tetrapod fluorescence.

Usage factors influencing e-scooter energy consumption: An empirical investigation

Shared e-scooters are considered a sustainable urban travel solution, yet their environmental impact is notable, primarily due to a short lifespan and the use of Li-ion batteries. The objective of this paper is to explore the possible factors with an influence on e-scooter energy consumption. These influential factors include trip and rider attributes, built environment characteristics, road geometry, surface materials, light and meteorological conditions. This study empirically investigates factors influencing e-scooter battery energy consumption, utilizing real usage data from GPS-equipped free-floating e-scooters in four European cities at the individual trip level. GPS positions allowed for the specification of local road characteristics and ambient conditions. For this purpose Shuttle Radar Topography Mission, Open Street Maps and the Meteostat application were used. Energy consumption was explained with the use of linear regression models as a function of those parameters, while controlling user experience and battery usage intensity. An extensive dataset covering over 150,000 trips in Bordeaux, Hamburg, Malaga, and Paris and two months of observations was used to estimate the models. Results indicate that, while travel distance is the most influential factor, other usage aspects play a role. Cold weather, rain, wind, as well as stone-paved streets increase energy consumption. In addition there seems to be a battery age threshold beyond which energy consumption rises.

Light conditions and the evolution of the visual system in birds.

Despite vision being an essential sense for many animals, the intuitively appealing notion that the visual system has been shaped by environmental light conditions is backed by insufficient evidence. Based on a comprehensive phylogenetic comparative analysis of birds, we investigate if exposure to different light conditions might have triggered evolutionary divergence in the visual system through pressures on light sensitivity, visual acuity, and neural processing capacity. Our analyses suggest that birds that have adopted nocturnal habits evolved eyes with larger corneal diameters and, to a lesser extent, longer axial length than diurnal species. However, we found no evidence that sensing and processing organs were selected together, as observed in diurnal birds. Rather than enlarging the processing centers, we found a tendency among nocturnal species to either reduce or maintain the size of the two main brain centers involved in vision-the optic tectum and the wulst. These results suggest a mosaic pattern of evolution, wherein optimization of the eye optics for efficient light capture in nocturnal species may have compromised visual acuity and central processing capacity.

Design of a Smart Lighting System Based on Sensor Integration and Automation

As a crucial application of modern technology, smart lighting systems are transforming our interaction with the living environment. The key lies in utilizing advanced sensor technology to maximize lighting efficiency and conserve energy. This paper focuses on designing a sensor-based lighting control system that integrates Passive Infrared and light intensity sensors for the automated management of environmental lighting. Our research has extensively explored the integrated application of PIR and light-intensity sensors. The design aims to automatically adjust indoor lighting based on environmental light conditions and the presence or absence of occupants to enhance comfort and energy efficiency. The sensor fusion algorithm was optimized through a series of experiments to improve detection accuracy and effective energy utilization. Based on the design analysis, the system can significantly enhance energy savings by reducing unnecessary lighting without compromising occupant comfort. The system’s design also considers rooms of varying sizes and layouts, demonstrating good adaptability and versatility. The significance of this research lies in providing innovative solutions for the smart lighting domain. By enhancing the intelligence and responsiveness of lighting systems in home and commercial environments, our design offers a more intuitive and energy-efficient lighting experience. It paves the way for future developments and innovations in lighting systems. This work highlights the immense potential of sensor-based systems in creating interactive and adaptive environments suitable for diverse settings such as homes, corridors, and underground garages.

High-Altitude Precision Landing by Smartphone Video Guidance Sensor and Sensor Fusion

This paper describes the deployment, integration, and demonstration of the Smartphone Video Guidance Sensor (SVGS) as novel technology for autonomous 6-DOF proximity maneuvers and high-altitude precision landing of UAVs via sensor fusion. The proposed approach uses a vision-based photogrammetric position and attitude sensor (SVGS) to support the precise automated landing of a UAV from an initial altitude above 100 m to ground, guided by an array of landing beacons. SVGS information is fused with other on-board sensors at the flight control unit to estimate the UAV’s position and attitude during landing relative to a ground coordinate system defined by the landing beacons. While the SVGS can provide mm-level absolute positioning accuracy depending on range and beacon dimensions, the proper operation of the SVGS requires a line of sight between the camera and the beacon, and readings can be disturbed by environmental lighting conditions and reflections. SVGS readings can therefore be intermittent, and their update rate is not deterministic since the SVGS runs on an Android device. The sensor fusion of the SVGS with on-board sensors enables an accurate and reliable update of the position and attitude estimates during landing, providing improved performance compared to state-of-art automated landing technology based on an infrared beacon, but its implementation must address the challenges mentioned above. The proposed technique also shows significant advantages compared with state-of-the-art sensors for High-Altitude Landing, such as those based on LIDAR.

Unstable environmental conditions constrain the fine-tune between opsin sensitivity and underwater light in an Amazon forest stream fish.

Visual adaptations can stem from variations in amino acid composition, chromophore utilization, and differential opsin gene expression levels, enabling individuals to adjust their light sensitivity to environmental lighting conditions. In stable environments, adaptations often involve amino acid substitutions, whereas in unstable conditions, differential gene expression may be a more relevant mechanism. Amazon forest streams present diverse underwater lighting conditions and experience short-term water colour fluctuations. In these environments, it is less likely for genetic and amino acid sequences to undergo modifications that tailor opsin proteins to the prevailing lighting conditions, particularly in species having several copies of the same gene. The sailfin tetra, Crenuchus spilurus, inhabits black and clear water Amazon forest streams. The long-wavelength sensitivity (LWS) is an important component for foraging and courtship. Here, we investigated LWS opsin genes in the sailfin tetra. Three copies of LWS1 and two copies of LWS2 genes were found. The maximum absorbance wavelength (λmax) estimated from the amino acid sequences of LWS1 genes exhibited variation among the different copies. In contrast, the copies of LWS2 genes showed identical expected λmax values. Although the amino acid positions affecting λmax varied among LWS genes, they remained consistent among populations living in different water colours. The relative expression levels of LWS genes differed between gene copies. While not formally tested, our results suggest that in fluctuating environments, visual adaptations may primarily stem from alterations in gene expression profiles and/or chromophore usage rather than precise genetic tuning of protein light sensitivity to environmental lighting conditions.

Hypnotic effects of melatonin depend on the environmental lighting conditions in the rat.

Acute effects of exogenous melatonin have been widely reported to promote sleep or induce drowsiness in human. However, testing of the hypnotic effects of melatonin in nocturnal rodents has yielded contradictory results. The latter may be associated with differences in concentration, lighting conditions, time of administration of melatonin, and possibly the type of analysis. In this study, electroencephalogram (EEG) and electromyogramwere recorded in pigmented male Brown Norway rats under both light-dark (LD) and constant dark (DD) conditions. Melatonin was administered intraperitoneally at a moderate dose of 3 mg/kg, at either 1 h after lights on under LD condition or 1 h after the activity offset under DD condition. The dosage is known to be able to entrain nocturnal rodents in DD conditions, but does not change sleep in rodents in LD. Only the rats under DD conditions showed a significant reduction in nonrapid eye movement (NREM) sleep latency, while the NREM sleep power spectrum remained unaffected. Under LD condition, melatonin did not alter NREM and rapid eye movement (REM) sleep latency, and had only minor effects on the NREM sleep EEG. Regardless of lighting conditions, melatonin administration resulted in less, but longer episodes for all vigilance states suggesting increased vigilance state consolidation. In the discussion, we compare our results with a summary of previously published data concerning the hypnotic effects of melatonin in polysomnographic/EEG-confirmedsleep in humans and nocturnal rodents. In conclusion, the hypnotic effect of exogenous melatonin in nocturnal rodents not only depends on the time of day, and concentration, but is also influenced by the lighting conditions. Regardless of inducing sleep or not, melatonin may consolidate sleep and through that enhance sleep quality.

Regulatory dynamics of the higher-plant PSI–LHCI supercomplex during state transitions

State transition is a fundamental light acclimation mechanism of photosynthetic organisms in response to the environmental light conditions. This process rebalances the excitation energy between photosystem I (PSI) and photosystem II through regulated reversible binding of the light-harvesting complex II (LHCII) to PSI. However, the structural reorganization of PSI–LHCI, the dynamic binding of LHCII, and the regulatory mechanisms underlying state transitions are less understood in higher plants. In this study, using cryoelectron microscopy we resolved the structures of PSI–LHCI in both state 1 (PSI–LHCI-ST1) and state 2 (PSI–LHCI–LHCII-ST2) from Arabidopsis thaliana. Combined genetic and functional analyses revealed novel contacts between Lhcb1 and PsaK that further enhanced the binding of the LHCII trimer to the PSI core with the known interactions between phosphorylated Lhcb2 and the PsaL/PsaH/PsaO subunits. Specifically, PsaO was absent in the PSI–LHCI-ST1 supercomplex but present in the PSI–LHCI–LHCII-ST2 supercomplex, in which the PsaL/PsaK/PsaA subunits undergo several conformational changes to strengthen the binding of PsaO in ST2. Furthermore, the PSI–LHCI module adopts a more compact configuration with shorter Mg-to-Mg distances between the chlorophylls, which may enhance the energy transfer efficiency from the peripheral antenna to the PSI core in ST2. Collectively, our work provides novel structural and functional insights into the mechanisms of light acclimation during state transitions in higher plants.

O030 GABAA Receptor Expression in the Suprachiasmatic Nucleus under Different Light Conditions

Abstract Our research group has made inroads investigating the phase shifting effects of general anaesthesia (GA) on the circadian clock. Most clinical anaesthetics function by potentiating the effect of GABA on the GABA type A receptor (GABAARs). While the precise role of GABA in the suprachiasmatic nucleus (SCN) is still not fully understood, it has been implicated in circadian functions including photic entrainment and clock coupling. However, we have discovered that the expression of GABAARs in the central circadian clock remains poorly understood. To address this gap in knowledge, we examined the expression of GABAAR subunits α1, α5, β3, and γ2 in male (n = 80) and female (n = 82) C57Bl/6 mice under light-dark (LD) and constant darkness (DD) conditions (male, n = 95). Analysis of GABAAR subunit expression in the SCN was quantified by immunohistochemical analysis. Additionally, we investigated the time-dependent effects of isoflurane GA and light on GABAAR subunit expression in the SCN (male, n = 60). Our findings revealed rhythmic expression of GABAAR subunits in the mouse SCN under LD conditions which differed by sex, suggesting environmental light conditions may regulate GABAAR expression in the circadian clock in a sex-specific manner. In the SCN, γ2 subunit expression was increased following light and GA treatment compared to light-alone, while α1 subunit expression was increased at times of large behavioural phase delays. We conclude that the expression of GABAAR’s in the SCN is phase-dependent and may contribute to the time-dependent relationship between light and GA on the clock.

Effect of light bias on male mating signal and female mate choice in a sexually dimorphic Amazon fish

Colourful signals are usually honest indicators of mate quality since they are energetically costly. However, how colours are perceived by choosers is highly affected by the environmental light condition. Amazon black waters are strongly red-biased while clear waters show no apparent colour bias. The sailfin tetra Crenuchus spilurus is a sexually dimorphic Amazon fish species; males have hyperallometric dorsal and anal fins conspicuously ornamented with red and yellow markings. The species has two main lineages, which inhabit black and clear waters. A comparison of the red colouration of the ornaments of males from different lineages indicates that red bias increases the perceived intensity of red colouration but decreases the perceived among-individual variation in red colour. In mate choice experiments, females from all lineages preferred males with larger ornaments. Clear water lineage females were more likely to accept males under red-biased lighting, which increases the apparent red colouration, suggesting the importance of the red colouration in their mate choice. On the other hand, male acceptance by females from black waters did not change under different light conditions, suggesting that signals other than the red colouration (e.g. size of ornaments) were more important in their mate choice.

Medium-Energy Proton Detector Onboard the FY-4B Satellite

This work introduces the instrument design of the medium-energy proton detector (MEPD, detection range: 30 keV–5 MeV) mounted on the Chinese Fengyun-4B (FY-4B) satellite. Compared to a similar detector on the Fengyun-3E (FY-3E) satellite, this instrument has undergone significant changes due to the different orbital radiation environment and solar lighting conditions. Based on the calculation of the radiation model AP8, the geometrical factor is reduced to 0.002 cm2sr, while that of the MEPD on the FY-3E satellite is 0.005 cm2sr. Another difference is that the sensors in some directions are exposed to direct sunlight for 80 min every day on this orbit, depending on the attitude angle of the satellite, which is much worse than that on the FY-3E satellite. According to the calculation results of transmittance of photons through different materials, a 100 nm thickness nickel film is added in front of the sensors to eliminate light pollution completely. The test using a solar simulator shows that the measure is effective and the detector has no error count when the solar irradiance coefficient is 1.0. In addition, the Geant4 software is applied to simulate the particle transportation process under complete machine condition to check the contamination of electrons in the sensors in all directions after magnetic deflection. The data obtained in orbit show that the instrument works properly, and the data are in good agreement with the AP8 model. The observations of the MEPD on board the FY-4B satellite can provide important support for the safety of spacecraft and theoretical research related to space weather.

Leaf and wood functional traits explain the strategies developed by Byrsonima sericea (Malpighiaceae) to survive in Atlantic Forest ecosystems under water and light variations

The Atlantic Forest is a heterogeneous biome comprised of different phytophysiognomies with contrasting microclimatic and edaphic characteristics, such as sandbanks and forests. Sandbanks are ecosystems with low water availability and high irradiance, requiring leaf and wood specific adjustments from species to survive. On the other hand, tropical rain forests lack a pronounced dry season, providing enough resources to allow competition from light-demanding trees and sustaining a spectrum of shade tolerance for understory species. To better understand how functional traits are determined, it is necessary to evaluate variables that are site-specific, i.e. that are displayed within an organism in different environments. We aimed to assess how does variation in the functional traits of the leaf and wood of Byrsonima sericea influence the survival abilities of this species to thrive under contrasting scenarios of light and water availability. Also, which set of morpho-anatomical and physiological traits are considered to be site-specific responses that are affecting positively the capacity of the species to adapt in these contrasting scenarios of the Atlantic Forest? The high irradiance in sandbank shaped functional traits of B. sericea leaves that allowed an allocation strategy of the available resources, with investment in leaf mass rather than in trunk biomechanics and hydraulic efficiency. The higher leaf density through smaller and numerous cells along with higher stomatal density and area, facilitating CO2 diffusion, were associated with a greater photosynthetic capacity and greater intrinsic water use efficiency. As in the forest, light is a limiting factor for species to grow, the fluctuating light over a short timescale can influence whole plant performance, thus requiring an investment in trunk biomechanics. Additionally, a set of wood traits in the forest was related to water availability favoring wider vessel elements with thicker walls, increasing the theoretical hydraulic conductivity, even though it implicated a higher vulnerability to cavitation. Our study has demonstrated that variation of traits of different plant structures, such as the leaf and wood, within a species has direct implications in the survival strategies at each environmental conditions of light and water availability. It is also stated that there are different sets of functional traits which are responsible for allocation strategies, leading to specific trade-offs that allow the species to display site-specific responses in order to survive.

Acute Circadian Disruption Due to Constant Light Promotes Caspase 1 Activation in the Mouse Hippocampus.

In mammals, the circadian system controls various physiological processes to maintain metabolism, behavior, and immune function during a daily 24 h cycle. Although driven by a cell-autonomous core clock in the hypothalamus, rhythmic activities are entrained to external cues, such as environmental lighting conditions. Exposure to artificial light at night (ALAN) can cause circadian disruption and thus is linked to an increased occurrence of civilization diseases in modern society. Moreover, alterations of circadian rhythms and dysregulation of immune responses, including inflammasome activation, are common attributes of neurodegenerative diseases, including Alzheimer', Parkinson's, and Huntington's disease. Although there is evidence that the inflammasome in the hippocampus is activated by stress, the direct effect of circadian disruption on inflammasome activation remains poorly understood. In the present study, we aimed to analyze whether exposure to constant light (LL) affects inflammasome activation in the mouse hippocampus. In addition to decreased circadian power and reduced locomotor activity, we found cleaved caspase 1 significantly elevated in the hippocampus of mice exposed to LL. However, we did not find hallmarks of inflammasome priming or cleavage of pro-interleukins. These findings suggest that acute circadian disruption leads to an assembled "ready to start" inflammasome, which may turn the brain more vulnerable to additional aversive stimuli.

Drivers of contrasting boreal understory vegetation in coniferous and broadleaf deciduous alternative states

AbstractAlternative states defined by tree‐canopy dominance result in different ecosystem functioning and shape habitat conditions for the understory vegetation. One example in the boreal forest is the alternation between broadleaf deciduous and coniferous forests. Disturbances related to natural fires and human land uses have produced changes in tree‐canopy dominance in the boreal region where coniferous forests change to broadleaved forests, affecting understory community dynamics and their related ecosystem processes and functions. To analyze the factors driving changes in understory vegetation and the resistance of its vegetation to shifts between alternative states, we compared the effects of changes in the system between two contrasting boreal forest types (black spruce vs. trembling aspen) in adjacent stands with similar topoedaphic conditions. We performed a 5‐year in situ experiment using alternative states as a theoretical framework including two approaches: (1) the ecosystem approach, manipulating environmental conditions of light, litter, and nutrients in each forest type to determine the main mechanisms associated with tree‐canopy dominance that affect the diversity and composition of understory communities; and (2) the community approach, physically exchanging understory communities between alternative states, to determine their resistance under a new tree‐canopy dominance through time, as well as the resilience of the forest understory after a small‐scale disturbance. Results indicate that the understory vegetation of trembling aspen forests were resistant through time both after changes in local conditions in the ecosystem approach and in the new black spruce‐dominated alternative state in the community approach. In contrast, mosses and ericaceous plants that typically dominate the forest floor of black spruce forests were negatively affected by the physical effect of broadleaf litter addition in our ecosystem approach and they were not resistant when transplanted to trembling aspen forests in the community approach, as they decreased in abundance and were invaded by aspen understory community species over time. The understory vegetation is a key forest ecosystem driver that can contribute to maintain the resilience of the boreal system and help to preserve their ecosystem services, which is a key aspect to consider in forest management faced with the effects of climate change.

Agreement between Two Devices for Measuring Pupil Diameter in Patients Implanted with Multifocal Intraocular Lenses.

The purpose of this study was to evaluate the agreement between three methods for measuring pupil size in patients implanted with multifocal intraocular lenses (MIOLs): Keratograph 5M (K5M), Pentacam AXL Wave (PW), and a simple hand ruler. Sixty-nine subjects implanted with MIOLs and measured at the three-month follow-up visit were included in this retrospective analysis. K5M and PW were used to measure the photopic (PP) and mesopic (MP) pupil sizes, and a hand ruler was used to measure the pupil under environmental light conditions (135 lux). The Bland-Altman method with its limits (LoAs) was used to assess the agreement. The median PP was 2.8, 2.95, and 3 mm for K5M, PW, and the ruler, respectively (p < 0.05). Differences in PP were statistically significant for all paired comparisons (p < 0.0005) except between PW and the ruler (p = 0.44). The LoAs for the difference in PP between K5M and PW was 0.63 mm. The mean difference for MP between K5M and PW was 0.04 mm (p = 0.34) with LoAs of 0.72 mm. MP measured with K5M and PW could be considered interchangeable, although a correction of -0.3 mm (IC95%: -0.23 to -0.39) should be applied to PP measured with PW to attain the K5M mean.

The Interplay between Different Stimuli in a 4D Printed Photo-, Thermal-, and Water-Responsive Liquid Crystal Elastomer Actuator.

Multi-stimuli responsivity in 3D-printed objects is receiving much attention. However, the simultaneous interplay between different environmental stimuli is largely unexplored. In this work, we demonstrate direct ink writing of an oligomeric ink containing an azobenzene photo-switch with an accessible hydrogen bond allowing triple responsivity to light, heat, and water. The resulting printed liquid crystal elastomer performs multiple actuations, the specific response depending on the environmental conditions. Bilayer films formed by printing on a static substrate can rapidly change shape, bending almost 80 degrees if irradiated in air or undergoing a shrinkage of about 50 % of its length when heated. The bilayer film assumes dramatically different shapes in water depending on combined environmental temperature and lighting conditions.

Physiological Effect of Extended Photoperiod and Green Wavelength on the Pituitary Hormone, Sex Hormone and Stress Response in Chub Mackerel, Scomber japonicus

Chub mackerel, Scomber japonicus, is heavily farmed and harvested due to its demand as a high-quality protein source rich in fatty acids. However, the effects of environmental cues on sexual maturation of the fish remain understudied. We aim to elucidate the effect of light manipulation on the hormones related to reproduction and on the stress response in the species. Mackerel were exposed to different photoperiods (12 h light:12 h dark or 14 h light:10 h dark) and light wavelengths (provided by white fluorescent bulbs or green LEDs). Total RNA extracted from the brain was assayed with quantitative polymerase chain reaction (a powerful technique for advancing functional genomics) and blood plasma was analyzed via immunoassay using ELISA kits. The mRNA expression of gene-encoding gonadotropin-releasing hormone, gonadotropin hormone, follicle-stimulating hormone, and luteinizing hormone were significantly increased through the use of an extended photoperiod and green wavelength, which also increased testosterone and 17β-estradiol plasma levels. Plasma levels of cortisol and glucose, which are indicators of a stress response, were significantly decreased through green LED exposure. Our results indicate that environmental light conditions affect the production of pituitary and sex hormones, and reduce the stress response in S. japonicus.

Defining the scope for altering rice leaf anatomy to improve photosynthesis: a modelling approach.

Leaf structure plays an important role in photosynthesis. However, the causal relationship and the quantitative importance of any single structural parameter to the overall photosynthetic performance of a leaf remains open to debate. In this paper, we report on a mechanistic model, eLeaf, which successfully captures rice leaf photosynthetic performance under varying environmental conditions of light and CO2 . We developed a 3D reaction-diffusion model for leaf photosynthesis parameterised using a range of imaging data and biochemical measurements from plants grown under ambient and elevated CO2 and then interrogated the model to quantify the importance of these elements. The model successfully captured leaf-level photosynthetic performance in rice. Photosynthetic metabolism underpinned the majority of the increased carbon assimilation rate observed under elevated CO2 levels, with a range of structural elements making positive and negative contributions. Mesophyll porosity could be varied without any major outcome on photosynthetic performance, providing a theoretical underpinning for experimental data. eLeaf allows quantitative analysis of the influence of morphological and biochemical properties on leaf photosynthesis. The analysis highlights a degree of leaf structural plasticity with respect to photosynthesis of significance in the context of attempts to improve crop photosynthesis.