Dim Conditions Research Articles

A-261 Outcome of a survey on dengue lateral flow immunoassay test kit reading and interpretation by medical laboratory staff in a hospital laboratory

Abstract Background Lateral flow immunoassay (LFIA) tests, first introduced in 1959, are now the mainstay of clinical laboratories. Khoo Teck Puat Hospital (KTPH) is a 795-bed acute care general hospital located in the north of Singapore. The Department of Laboratory Medicine has been using dengue LFIA test kits for the detection of dengue NS1 antigen, IgM antibodies and IgG antibodies. While kits are cost-effective, user-friendly and provide rapid results, there is subjectivity in reading and interpretation of results. Methods We conducted a survey to assess test reading and interpretation by medical laboratory staff. Six serum and plasma specimens were analysed using Bioline™ Dengue IgG/IgM WB test device. Test kits at the end-point of sample incubation were photographed in both well-lit and dim conditions. A survey questionnaire was prepared using an online form builder tool using the photographs. Staff were invited to participate in the survey. They were allowed to report the result as ‘Positive’, ‘Negative’ or ‘Equivocal’. Results A total of sixteen responses were received. Results were 100% concordant for all 6 specimens in both well-lit and dim conditions. For one case, under a well-lit condition, 15 staff reported the result as ‘Positive’ while one staff reported ‘Equivocal’. Most of the reported results for samples with no consensus is split between ‘Positive’ and ‘Equivocal’. Conclusions Dengue viruses of all 4 known serotypes are endemic in Singapore. Positive results are tracked on a national level to identify areas of high dengue infection for intensive environmental and vector control measures. Hence, accurate reporting and identification of patients with dengue infection is important. Our survey shows that lighting conditions do not affect the interpretation of LFIA results. Reading and interpretation of dengue LFIA test kits however, remain dependent on user interpretation and newer test kits with optical readers may be useful in mitigating this.

Bilateral fusion low‐light image enhancement with implicit information constraints

AbstractResearch on low‐light image enhancement focuses on improving image quality in dim conditions. Recently, deep learning has driven significant advancements, with many studies using neural networks to enhance low‐light images. However, most focus on complex network designs to increase nonlinearity, often neglecting the implicit information from local image transformations. This paper introduces an improved U‐net‐based method for low‐light enhancement, retaining the original encoding network and adding branch links in the decoding network. The method uses attention feature fusion to handle image noise and gradients separately, adjusting brightness through a gradient‐adaptive transform. This approach optimizes performance using loss functions like peak signal‐to‐noise ratio and colour consistency. Unlike previous methods, the approach emphasizes extracting implicit information from image gradients, achieving enhancement that aligns with the original brightness distribution. The result is enhanced images with high detail similarity to the original, achieved through end‐to‐end inference in experiments.

Feline eye-inspired artificial vision for enhanced camouflage breaking under diverse light conditions.

Biologically inspired artificial vision research has led to innovative robotic vision systems with low optical aberration, wide field of view, and compact form factor. However, challenges persist in object detection and recognition against complex backgrounds and varied lighting. Inspired by the feline eye, which features a vertically elongated pupil and tapetum lucidum, this study introduces an artificial vision system designed for superior object detection and recognition in a monocular framework. Using a slit-like elliptical aperture and a patterned metal reflector beneath a hemispherical silicon photodiode array, the system reduces excessive light and enhances photosensitivity. This design achieves clear focus under bright light and enhanced sensitivity in dim conditions. Theoretical and experimental analyses demonstrate the system's ability to filter redundant information and detect camouflaged objects in diverse lighting, representing a substantial advancement in monocular camera technology and the potential of biomimicry in optical innovations.

Decoding the Preparation Stage of Target Shooting under Audiovisual Restricted Conditions: Investigating Neural Mechanisms Using Microstate Analysis.

Shooting is a fine sport that is greatly influenced by mental state, and the neural activity of brain in the preparation stage of shooting has a direct influence on the level of shooting. In order to explore the brain neural mechanism in the preparation stage of pistol shooting under audiovisual restricted conditions, and to reveal the intrinsic relationship between brain activity and shooting behavior indicators, the electroencephalography (EEG) signals and seven shooting behaviors including shooting performance, gun holding stability, and firing stability, were experimentally captured from 30 shooters, these shooters performed pistol shooting under three conditions, normal, dim, and noisy. Using EEG microstates combined with standardized low-resolution brain electromagnetic tomography (sLORETA) traceability analysis method, we investigated the difference between the microstates characteristics under audiovisual restricted conditions and normal condition, the relationship between the microstates characteristics and the behavioral indicators during the shooting preparation stage under different conditions. The experimental results showed that microstate 1 corresponded to microstate A, microstate 2 corresponded to microstate B, and microstate 4 corresponded to microstate D; Microstate 3 was a unique template, which was localized in the occipital lobe, its function was to generate the "vision for action"; The dim condition significantly reduced the shooter's performance, whereas the noisy condition had less effect on the shooter's performance; In audiovisual restricted conditions, the microstate characteristics were significantly different from those in the normal condition. Microstate 4' parameters decreased significantly while microstate 3' parameters increased significantly under restricted visual and auditory conditions; Dim condition required more shooting skills from the shooter; There was a significant relationship between characteristics of microstates and indicators of shooting behavior; It was concluded that in order to obtain good shooting performance, shooters should improve attention and concentrate on the adjustment of collimator and target's center leveling relation, but the focus was slightly different in the three conditions; Microstates that are more important for accomplishing the task have less variation in their characteristics over time; Similar conclusions to previous studies were obtained at the same time, i.e., increased visual attention prior to shooting is detrimental to shooting performance, and there is a high positive correlation with microstate D for task completion. The experimental results further reveal the brain neural mechanism in the shooting preparation stage, and the extracted neural markers can be used as effective functional indicators for monitoring the brain state in the shooting preparation stage of pistols.

Are there effects of light exposure on daytime sleep for rotating shift nurses after night shift?: an EEG power analysis.

Night-shift workers often face various health issues stemming from circadian rhythm shift and the consequent poor sleep quality. We aimed to study nurses working night shifts, evaluate the electroencephalogram (EEG) pattern of daytime sleep, and explore possible pattern changes due to ambient light exposure (30 lux) compared to dim conditions (<5 lux) during daytime sleep. The study involved 31 participants who worked night shifts and 24 healthy adults who had never worked night shifts. The sleep macro and microstructures were analyzed, and electrophysiological activity was compared (1) between nighttime sleep and daytime sleep with dim light and (2) between daytime sleep with dim and 30 lux light conditions. The daytime sleep group showed lower slow or delta wave power during non-rapid eye movement (NREM) sleep than the nighttime sleep group. During daytime sleep, lower sigma wave power in N2 sleep was observed under light exposure compared to no light exposure. Moreover, during daytime sleep, lower slow wave power in N3 sleep in the last cycle was observed under light exposure compared to no light exposure. Our study demonstrated that night shift work and subsequent circadian misalignment strongly affect sleep quality and decrease slow and delta wave activities in NREM sleep. We also observed that light exposure during daytime sleep could additionally decrease N2 sleep spindle activity and N3 waves in the last sleep cycle.

Detection of Safety Signs Using Computer Vision Based on Deep Learning

Safety signs serve as an important information carrier for safety standards and rule constraints. Detecting safety signs in mines is essential for automatically early warning of unsafe behaviors and the wearing of protective equipment while using computer vision techniques to realize advanced safety in the AI and IoT era. This work aims to propose an improved YOLOV4-tiny safety signs detection model applying deep learning to detect safety signs in mines. The dataset employed in this study was derived from coal mines and analogous environments, comprising a total of ten types of safety signs. It was partitioned into training, validation, and test sets following a distribution ratio of (training set + validation set) to test set = 9:1, with the training set to validation set ratio also set at 9:1. Then the attention mechanism ECANet was introduced into the model, which strengthened the network’s learning of places that need attention. Moreover, the Soft-NMS algorithm was used to retain more correct prediction frames and optimize the detection model to further improve the detection accuracy. The Focal Loss function was introduced to alleviate the problem of category imbalance in one-stage safety signs detection. Experimental results indicate that the proposed model achieved a detection precision of 97.76%, which is 7.55% and 9.23% higher than the YOLOV4-tiny and Faster RCNN algorithms, respectively. Besides, the model performed better in the generalization because it avoided the over-fitting phenomenon that occurred in the YOLOV4-tiny and the Faster RCNN. Moreover, the advantages of the improved model were more prominent when detecting small target areas and targets under dim conditions in coal mines. This work is beneficial for the intelligent early warning system with surveillance cameras in coal mines.

Modulating LiFi for dual operation in the visible and infrared spectra

Light-Fidelity (LiFi) has emerged in the last few years as a promising technology for alleviating the stringent demand for wireless data services. Prior works have considered LiFi operating either in the visible light or infrared spectrum. Each spectrum band has its own advantages: visible light allows leveraging existing infrastructure for communication, while infrared is not affected by light dimming. In this work, we propose a modulation scheme that retains the benefits of both bands, introducing a simple, low-cost, yet efficient dimming solution for LiFi networks. We compare the performance of the proposed dimming scheme with both the digital and analog dimming techniques traditionally used in LiFi systems. Simulation results show that our dimming solution offers better communication and illumination performance than previous proposals, providing larger signal-to-noise ratio, spectral efficiency, and a full and fine-grained dimming range. Finally, we prototype our solution by designing an extended version of the OpenVLC 1.3 platform, and we experimentally show its robust communication performance under different dimming conditions. We make the implemented system publicly available to the research community.

Navigational Competency is Mediated by Foraging Experience and Light Conditions in the Nocturnal Bull Ant Myrmecia midas

The nocturnal bull ants of the genus Myrmecia, Myrmecia midas travel in both bright and dim settings on the ground and also vertically up on trees navigating towards targets. It is known that foragers retain multiple panoramic memories of terrestrial landmarks as well as celestial cues along their foraging route. It is likely that they can compare these stored views with their current visual input to return to their nest. Here we examined whether nocturnal M. midas foragers’ navigational efficiency and success at view-based navigation suffer at low light levels (night time) compared with daylight levels of brightness. When exposed to panoramic cues in dim conditions, which had dimmer light levels than their peak foraging period, they were less well oriented and less likely to find the nest, with the catchment area smaller at night than during the day. At different displacement distances from the nest, initial navigational behaviours differed. Foragers displayed more scanning near the starting point at shorter distances, while with increasing distance they switched more to loops of systematic searching or heading off in some direction without scans. In the dim conditions, landmark guidance became less effective, perhaps explaining why foragers limit their navigational activities mostly to the twilight hours, when light levels are still adequate, and mostly forage in a tree through the night.

A Dual-Stream-Modulated Learning Framework for Illuminating and Super-Resolving Ultra-Dark Images.

Enhancement of image resolution for scenes captured under extremely dim conditions represents a practical yet challenging problem that has received little attention. In such low-light scenarios, the limited lighting and minimal signal clarity tend to intensify issues such as diminished detail visibility and altered color accuracy, which are often more severe during the image enhancement process than in scenarios with adequate lighting. Consequently, standard methods for enhancing low-light images or improving their resolution, whether implemented independently or through a combined approach, generally face challenges in effectively restoring luminance, preserving color integrity, and detailing intricate features. To conquer these issues, this article introduces an innovative dual-stream (DS) modulated learning framework designed to tackle the real-world coupled degradation issues in super-resolution (SR) under low-light conditions. Leveraging natural image color characteristics, we introduce a self-regularized luminance constraint to specifically target uneven illumination. We develop illumination-semantic dual modulator (ISDM), a refinement middleware embedded in the decoding stage to bridge illumination and semantic features concurrently, aimed at safeguarding the integrity of lighting and color details at the feature level. Our approach replaces simple upsampling methods with the resolution-sensitive merging upsampler (RSMU) module, which integrates diverse sampling techniques to effectively reduce artifacts and halo effects. Comprehensive experiments on three benchmarks showcase the applicability and generalizability of our approach to diverse and challenging ultra-poorly lit settings, outperforming state-of-the-art methods with a notable improvement. The code and benchmark are publicly available at https://github.com/moriyaya/UltraIS.

Diurnal differences in urine flow in healthy young men in a light-controlled environment: a randomized crossover design

BackgroundOlder men often experience nocturnal urination difficulties, reflected by diurnal differences in maximum urine flow (Qmax). Since lower urinary tract symptoms and pathological comorbidities are frequent in older men, it remains unclear whether this diurnal variation is a physiological or pathological phenomenon. Our aim was to quantify the diurnal variability of Qmax in healthy young participants under varying daylight conditions in a stable environment to discern potential underlying causes of nocturnal urination difficulties.MethodsTwenty-one healthy young men were recruited in a 4-day study utilizing daytime (08:00–18:00) exposure with two light conditions in randomized order: dim (< 50 lx) or bright (~2500 lx). Day 1 was for acclimation, and urine flow was assessed from day 2. The participants urinated ad libitum during day 2 and then at fixed 3–4-h intervals thereafter (days 3–4). Regular urination Qmax at late night (04:00) on day 4 was compared with the nearest voided volume during daytime of day 3 (mDay).ResultsMorning Qmax scores (after bed—11:00) on day 2 were significantly lower than evening (17:00—before pre-sleep) in bright conditions and those of daytime (11:00–17:00), evening (17:00—before pre-sleep), and pre-sleep in dim conditions. Pre-sleep Qmax during the ad libitum period was significantly higher in dim than bright conditions. Late-night Qmax values (04:00) on day 4 were significantly lower than Qmax scores of mDay on day 3 in both light conditions.ConclusionsHealthy young men had a clear diurnal Qmax difference that decreased during late night and morning. In addition, the pre-sleep Qmax values in dim daylight were significantly higher than in bright daylight. Taken together, we conclude that late-night and morning decreases in Qmax are an instinctive physiological phenomenon in humans, and the diurnal difference of Qmax can be influenced by daylight conditions.

P052 Is Circadian Adaptation to Night Work Affected by the Intensity of Ambient Lighting?

Abstract Introduction The aim of this study was to examine whether the intensity of ambient lighting affects the rate at which the human circadian system adapts to working at night. Methods. The whole study will include 60 participants (50:50, F:M; aged 28–35yr; good sleep/health) randomised to one of three conditions. In each condition, participants work 14 x 12-hr simulated night shifts (19:00–07:00h) while living 24h/day in an accommodation suite. The only difference between conditions is in the light intensity during night shifts – dim (5–10lx), moderate (50–100lx), normal (300–350lx). Circadian adaptation is being assessed using the hourly rate of 6-sulphatoxymelatonin (aMT6s) production during sleep. Results The project is in progress, so these results are for the first 6–12 participants in each condition. For each day, circadian adaptation is assessed by expressing the rate of aMT6s excreted during the daytime sleep period as a percentage of the rate of aMT6s excreted during the night-time baseline sleep period (for an adaption score of 0–100%). On average, participants in the dim condition are adapted by 26%,37%,32% after nights 1,7,14; participants in the moderate condition are adapted by 23%,37%,60% after nights 1,7,14; and participants in the normal condition are adapted by 27%,117%,103% after nights 1,7,14. Discussion These data indicate that the rate, and degree, of circadian adaptation to night work is substantially affected by the intensity of ambient lighting. Therefore, lighting conditions should be incorporated into OHS guidelines related to managing the fatigue risks associated with night work.

Inhibition of the interaction between Hippo/YAP and Akt signaling with ursolic acid and 3'3-diindolylmethane suppresses esophageal cancer tumorigenesis.

Hippo/YAP signaling hinders cancer progression. Inactivation of this pathway contributes to the development of esophageal cancer by activation of Akt. However, the possible interaction between Akt and Hippo/YAP pathways in esophageal cancer progression is unclear. In this study, we found that ursolic acid (UA) plus 3'3-diindolylmethane (DIM) efficiently suppressed the oncogenic Akt/Gsk-3β signaling pathway while activating the Hippo tumor suppressor pathway in esophageal cancer cells. Moreover, the addition of the Akt inhibitor LY294002 and the PI3K inhibitor 3-methyladenine enhanced the inhibitory effects of UA plus DIM on Akt pathway activation and further stimulated the Hippo pathway, including the suppression of YAP nuclear translocation in esophageal cancer cells. Silencing YAP under UA plus DIM conditions significantly increased the activation of the tumor suppressor PTEN in esophageal cancer cells, while decreasing p-Akt activation, indicating that the Akt signaling pathway could be down-regulated in esophageal cancer cells by targeting PTEN. Furthermore, in a xenograft nude mice model, UA plus DIM treatment effectively diminished esophageal tumors by inactivating the Akt pathway and stimulating the Hippo signaling pathway. Thus, our study highlights a feedback loop between the PI3K/Akt and Hippo signaling pathways in esophageal cancer cells, implying that a low dose of UA plus DIM could serve as a promising chemotherapeutic combination strategy in the treatment of esophageal cancer.

Research on the Improvement of Semi-Global Matching Algorithm for Binocular Vision Based on Lunar Surface Environment.

The low light conditions, abundant dust, and rocky terrain on the lunar surface pose challenges for scientific research. To effectively perceive the surrounding environment, lunar rovers are equipped with binocular cameras. In this paper, with the aim of accurately detect obstacles on the lunar surface under complex conditions, an Improved Semi-Global Matching (I-SGM) algorithm for the binocular cameras is proposed. The proposed method first carries out a cost calculation based on the improved Census transform and an adaptive window based on a connected component. Then, cost aggregation is performed using cross-based cost aggregation in the AD-Census algorithm and the initial disparity of the image is calculated via the Winner-Takes-All (WTA) strategy. Finally, disparity optimization is performed using left-right consistency detection and disparity padding. Utilizing standard test image pairs provided by the Middleburry website, the results of the test reveal that the algorithm can effectively improve the matching accuracy of the SGM algorithm, while reducing the running time of the program and enhancing noise immunity. Furthermore, when applying the I-SGM algorithm to the simulated lunar environment, the results show that the I-SGM algorithm is applicable in dim conditions on the lunar surface and can better help a lunar rover to detect obstacles during its travel.

Comparison of current paediatric contrast sensitivity assessments using simulated reduced contrast thresholds

ABSTRACT Purpose There are limited tests of contrast sensitivity (CS) for use in children. The Hiding Heidi (HH) is suitable for all cognitive abilities, but has a ceiling effect. The Double Happy (DH) test has comparable thresholds to the Pelli Robson (PR), however the ability to detect changes in contrast has not been established. This study aims to compare contrast thresholds and agreement between HH and the DH, comparing to the PR chart in normal conditions and under reduced visual and lighting conditions. Methods Tests were repeated under different conditions to reduce the contrast. Room illumination was 20,900{plus minus}2% lux in bright conditions and 2,000{plus minus}2% lux in dim conditions, both conditions were repeated with the addition of simulation spectacles to reduce the clarity of vision. Participants’ CS was measured uniocularly using the PR, HH and DH tests. Results 50 participants, age 18–62 years (mean{plus minus}standard deviation: 24.5{plus minus}7.98), were assessed. On HH 94% (n = 47) reached the maximum score, with the DH it was 18% (n = 9). The difference in reduction between conditions was smaller with HH in comparison to PR and DH, but significantly different from baseline conditions. Under dim conditions the reduction in PR and DH was −0.21 logCS units, but only −0.04 logCS for HH. Conclusion The DH test has better agreement with PR than HH and is better at detecting CS changes, highlighting the advantages of use in clinical practice.

The snow alga Chloromonas kaweckae sp. nov. (Volvocales, Chlorophyta) causes green surface blooms in the high tatras (Slovakia) and tolerates high irradiance.

Seasonally slowly melting mountain snowfields are populated by extremophilic microalgae. In alpine habitats, high-light sensitive, green phytoflagellates are usually observed in subsurface layers deeper in the snowpack under dim conditions, while robust orange to reddish cyst stages can be seen exposed on the surface. In this study, uncommon surface green snow was investigated in the High Tatra Mountains (Slovakia). The monospecific community found in the green surface bloom consisted of vegetative Chloromonas cells (Volvocales, Chlorophyta). Molecular data demonstrated that the field sample and the strain isolated and established from the bloom were conspecific, and they represent a new species, Chloromonas kaweckae sp. nov., which is described based on the morphology of the vegetative cells and asexual reproduction and on molecular analyses of the strain. Cells of C. kaweckae accumulated approximately 50% polyunsaturated fatty acids, which is advantageous at low temperatures. In addition, this new species performed active photosynthesis at temperatures close to the freezing point showed a light compensation point of 126 ± 22 μmol photons·m-2 ·s-1 and some signs of photoinhibition at irradiances greater than 600 μmol photons·m-2 ·s-1 . These data indicate that the photosynthetic apparatus of C. kaweckae could be regarded as adapted to relatively high light intensities, otherwise unusual for most flagellate stages of snow algae.

Dark Adaptation in Urban Environments: An Innovative Design Framework for Pedestrian Lighting

Outdoor lighting has mainly been approached as an engineering subject throughout its history. The current urban lighting requirements are established upon factors which mainly refer to motorised traffic dynamics. As a consequence, excessive lighting levels are found in the city environments with a negative impact on the human as well as the environmental sphere. By synthesising scientific knowledge on human visual system and outdoor lighting theories, this research seeks to formulate strong arguments to point at the lack of human scale in the contemporary practice and to question the adequacy of the standard requirements for human vision in nighttime settings. The knowledge gained from scientific studies and ongoing research shows how the nighttime visual experience of pedestrians is still an untapped dimension, unveiling the lack of defined guidelines and methods to approach the design of urban lighting through the lens of this target. With a focus on soft mobility, the aim of the study is to address dark adaptation as a human factor in the design of urban lighting and to provide evidence on the human eye’s ability to perform in dim conditions. Important findings from the literature review were used as requirements to formulate a methodology to approach the design of pedestrian lighting in urban environments. Strong conclusions could be drawn on the figure of dark adaptation and important lighting requirements were identified to facilitate this process in the condition of soft mobility. Even though further research and experimentation are required to implement dark adaptation in the design of urban lighting, this paper’s goal is to open up new perspectives in the field, shaping the vision for the future of cities with reduced urban illumination.

Visual Comfort and Acute Alerting Effects of Diurnal Intermittent Bright Light

ABSTRACT Intermittent bright light during the night has shown to be able to generate circadian phase-shifting effects, suppress melatonin and induce alertness, but little attention has been devoted to the effects of diurnal intermittent bright light. Following a night of sleep restriction, forty participants were exposed in a counterbalanced within-subject design to an intermittent (100 lux – 1000 lux), a continuous dim (100 lux) and a continuous bright light condition (1000 lux) each lasting 90 min. Repeated assessments of self-reported sleepiness, cognitive performance and physiological arousal as well as subjective visual comfort were taken during each light condition. Results showed that alertness-related parameters were not significantly affected by the light conditions: neither the intermittent nor the bright condition improved alertness compared to the dim condition. Visual comfort was highest in the dim condition, followed by the intermittent and bright conditions respectively, even though the visualizations showed marked decreases in visual comfort during the bright light phases in the intermittent condition. The results illustrate the diversity in mechanisms underlying these visual experiences and neurobehavioral responses.

Lack of local adaptation of feeding and calling behaviours by Yponomeuta cagnagellus moths in response to artificial light at night

Artificial light at night (ALAN) is one of the suggested drivers of the global decline in insects, including moths. ALAN strongly affects moth physiology and behaviour, but it remains unknown whether ALAN is a selective pressure that drives adaptation and evolution in moths. We assess whether feeding and calling behaviours of Yponomeuta cagnagellus moths are locally adapted to ALAN. Collected from locations that were either illuminated or dark at night-time for several decades, moths were exposed to different light intensities in a laboratory experiment. Male moths, but not female moths, fed less frequently in bright light than in dark or dim conditions. Female calling was less frequent in dimly or brightly lit conditions than in the dark treatment. Individuals from illuminated source populations showed increased feeding behaviour by males and marginally decreased calling behaviour by females. Our study suggests that ALAN affects the phenotypical calling behaviour by females and feeding behaviour by male moths of Y. cagnagellus but has not resulted in adaptation. Long-term ALAN conditions also affected feeding and marginally affected calling frequency. Reduced calling in lit conditions, perhaps driven by a reduced need for such behaviour because of an increase in visual cues or through the proximity of individuals in lit conditions, may result in long-term adaptation. Studies into more moth species are required to determine the extent to which a lack of adaptation to ALAN may contribute to current global declines in moth populations.

Central Zone Size Dependence of Peripheral Dimming Technique Under Wide Field of View Environment

Peripheral dimming technique based on gaze tracking was proposed to reduce the power consumption of emissive displays adopted in headset. This technique divides an image into two zones: a central zone which is a circular area centered on the gaze point, and a peripheral zone which is the outer area of the central zone. This technique achieves power savings by gradually reducing the brightness in the peripheral zone while maintaining the brightness of the central zone. This paper investigates effects of central zone size (CZS) on the technique under a wide field of view (FoV) environment. Psychophysical experiments are conducted to determine the threshold dimming conditions for the CZSs of 10°, 25°, and 40°. The results showed that the individual variations and the mean value of threshold dimming condition increased in proportion to CZS. Interestingly, in contrast, the power-saving efficiency depending on the CZS was not significantly different. The technique can reduce power consumption of display panel by approximately 12% on average, up to 15%. It is demonstrated that the technique is feasible even in a wide FoV environment, and the CZS can be flexibly determined depending on the application or image content.

Effects of insemination and blood-feeding on locomotor activity of wild-derived females of the malaria mosquito Anopheles coluzzii

BackgroundBehavioural shifts in the canonical location and timing of biting have been reported in natural populations of anopheline malaria vectors following the implementation of insecticide-based indoor vector control interventions. These modifications increase the likelihood of human-vector contact and allow mosquitoes to avoid insecticides, both conditions being favourable to residual transmission of the malarial parasites. The biting behaviour of mosquitoes follows rhythms that are under the control of biological clocks and environmental conditions, modulated by physiological states. In this work we explore modifications of spontaneous locomotor activity expressed by mosquitoes in different physiological states to highlight phenotypic variability associated to circadian control that may contribute to explain residual transmission in the field.MethodsThe F10 generation progeny of field-collected Anopheles coluzzii from southwestern Burkina Faso was tested using an automated recording apparatus (Locomotor Activity Monitor, TriKinetics Inc.) under LD 12:12 or DD light regimens in laboratory-controlled conditions. Activity recordings of each test were carried out for a week with 6-day-old females belonging to four experimental treatments, representing factorial combinations of two physiological variables: insemination status (virgin vs inseminated) and gonotrophic status (glucose fed vs blood fed). Chronobiological features of rhythmicity in locomotor activity were explored using periodograms, diversity indices, and generalized linear mixed modelling.ResultsThe average strength of activity, onset of activity, and acrophase were modulated by both nutritional and insemination status as well as by the light regimen. Inseminated females showed a significant excess of arrhythmic activity under DD. When rhythmicity was observed in DD, females displayed sustained activity also during the subjective day.ConclusionsInsemination and gonotrophic status influence the underlying light and circadian control of chronobiological features of locomotor activity. Overrepresentation of arrhythmic chronotypes as well as the sustained activity of inseminated females during the subjective day under DD conditions suggests potential activity of natural populations of A. coluzzii during daytime under dim conditions, with implications for residual transmission of malarial parasites.Graphical abstract