High Illumination Research Articles

Super-Resolution Live Cell Imaging of Subcellular Structures.

There has long been a crucial tradeoff between spatial and temporal resolution in imaging. Imaging beyond the diffraction limit of light has traditionally been restricted to be used only on fixed samples or live cells outside of tissue labeled with strong fluorescent signal. Current super-resolution live cell imaging techniques require the use of special fluorescence probes, high illumination, multiple image acquisitions with post-acquisition processing, or often a combination of these processes. These prerequisites significantly limit the biological samples and contexts that this technique can be applied to. Here we describe a method to perform super-resolution (~140 nm XY-resolution) time-lapse fluorescence live cell imaging in situ. This technique is also compatible with low fluorescent intensity, for example, EGFP or mCherry endogenously tagged at lowly expressed genes. As a proof-of-principle, we have used this method to visualize multiple subcellular structures in the Drosophila testis. During tissue preparation, both the cellular structure and tissue morphology are maintained within the dissected testis. Here, we use this technique to image microtubule dynamics, the interactions between microtubules and the nuclear membrane, as well as the attachment of microtubules to centromeres. This technique requires special procedures in sample preparation, sample mounting and immobilizing of specimens. Additionally, the specimens must be maintained for several hours after dissection without compromising cellular function and activity. While we have optimized the conditions for live super-resolution imaging specifically in Drosophila male germline stem cells (GSCs) and progenitor germ cells in dissected testis tissue, this technique is broadly applicable to a variety of different cell types. The ability to observe cells under their physiological conditions without sacrificing either spatial or temporal resolution will serve as an invaluable tool to researchers seeking to address crucial questions in cell biology.

Change of transcription level of photoreceptor-specific CRX gene in the peripheral blood of the participants of an arctic world oceanic international flight

To reveal the dynamics of CRX expression level in humans after a prolonged temporary exposure to polar day conditions. The study included 6 pilots (males from 39 to 69 y.o.) who participated in the Arctic World Oceanic International Flight Sever Vash (West to East, from 62°N 74°E to 72°N 114°E). Samples of peripheral blood for RNA isolation were collected at the start and at the end of the flight. The level of mRNA in the samples was evaluated based on the data of quantitative real-time PCR of the CRX gene, as well as the b2M and TBP housekeeping genes (reference). Expression of the CRX gene in the studied group (p<0.01) was revealed; the total average level of mRNA was about 3 times higher prior to, and approximately 7 times higher after normalization to the b2M gene. Five pilots had increased expression of the CRX gene within the range of -1.53 to -3.07 (Z-score of <0 before the flight and >0 after the flight). In one pilot, the level of CRX expression was higher at the start, but it reduced by the end of the circumnavigation flight. The results confirm the hypothesis that the CRX gene is expressed after a prolonged temporary exposure to polar day conditions. It was also revealed that during rapid adaptation, equal changes in the illumination of retinal photoreceptors lead to different individual dynamics of CRX expression.

Underground Coal Mine Target Tracking via Multi-Feature Joint Sparse Representation

Single-feature methods are unable to effectively track a target in an underground coal mine video due to the high background noise, low and uneven illumination, and drastic light fluctuation in the video. In this study, we propose an underground coal mine personnel target tracking method using multi-feature joint sparse representation. First, with a particle filter framework, the global and local multiple features of the target template and candidate particles are extracted. Second, each of the candidate particles is sparsely represented by a dictionary template, and reconstruction is achieved after solving the sparse coefficient. Last, the particle with the lowest reconstruction error is deemed the tracking result. To validate the effectiveness of the proposed algorithm, we compare the proposed method with three commonly employed tracking algorithms. The results show that the proposed method is able to reliably track the target in various scenarios, such as occlusion and illumination change, which generates better tracking results and validates the feasibility and effectiveness of the proposed method.

Exploring the Challenges and Promises of Automotive HUDs

INFORMATION DISPLAY LAST INCLUDED A special automotive display theme in its July/August 2020 issue. At the time, I and others from SID's Metro Detroit Chapter were organizing our 27th Annual Vehicle Displays and Interfaces Symposium (vehicledisplay.org), which, under the circumstances, of the coronavirus pandemic was reimagined as an online event. In this issue and the March/April 2021 issue, we revisit the symposium with an exploration of some of its most compelling points by Kyle Davis, a senior data analyst at IHS Markit, and two exciting articles on head-up displays (HUDs) that were selected as best papers by the symposium session chairs. The first, “Investigating Human Perception Studies for Head-Up Display Ghosting,” by Steve Pankratz, William Diepholz, and John Vanderlofske of 3M, covers a topic that is growing in importance because of the increase in vehicles with large multi-color (or full color) HUDs. SAE International most recently addressed ghosting in its automotive HUD standard SAE J1757-2, published in November 2018.1 The second article will appear in the March/April 2021 issue. “Holographic Optical Elements and Projector Design Considerations for Automotive Windshield Displays” by Sam Martin and Jason Thompson of Texas Instruments and Ian Redmond of Ceres Holographics offers a market overview of HOE automotive applications and performance and projector design considerations when illuminating holographic films. The specially designed films are inserted or attached to the windshield or combiner to allow information to be displayed. As long as vehicles are not fully automated (Level 5 of the six levels of driving automation SAE outlines in its J3016 standard), critical information needs to be legible and easy to comprehend so that the driver's attention remains fixed on the road. The windshield HUD (wHUD) or combiner HUD (cHUD), paired with advanced driver-assistance systems (ADAS), is a darling of the automotive safety world because it allows for quicker reaction times to visual information (see “Turning Automotive Windows into the Ultimate HMIs” in the July/August 2020 issue). However, that advantage comes with significant engineering disadvantages, including ghost images in the windshield, high ambient lighting and temperatures because of sun exposure, and the high cost of an HUD option. Nonetheless, because of the increase in the HUD's displayed image and, therefore, the increase in the field of view (FOV) from the evaluation points and multiple viewpoints as described in SAE J 1757-2 (see Fig. 1), ghosting and its challenges are the most important problems to solve. An overview of a computer-aided design with traditional eye boxes. Courtesy of the author The evaluation point for display performance cannot solely be the traditional centroid of the cyclopean eye ellipse. For wHUDs and some cHUDs, ghosting depends on view location and must be eliminated or rendered non-visible by the driver. (This can be even more complicated for taller or shorter drivers if the FOV variations set by automotive original equipment manufacturers [AOEMs] is not optimized for their viewing). Despite huge investments and technological improvements, Level 4 (in which an automated driving system [ADS] can do all the driving in certain circumstances) and Level 5 vehicles are still a long way off from production. Level 3 automation—conditional automation in which the driver must be ready to take over from autonomous mode at some points—is entering production,2 although many experts have safety concerns about it: Because it allows drivers to disengage, they may be slow to react if they need to resume control. For driver-in-control vehicles (SAE Levels 1 and 2 and sometimes Level 3), not only ghosting but also high ambient illumination is a significant engineering issue for any display operating outdoors. Military labs have developed standards and specifications for evaluation using costly integrated spheres and devices that are not affordable for consumers. The articles outlined here should lend some clarity to these important topics. Silviu Pala has been chairman of SID's Metro Detroit Chapter since 1998 and of the SAE Vehicle Flat Panel Display (VFPD) group since 1999. He is the co-general program chair of SID's Annual Symposium on Vehicle Displays and Interfaces. A former director of technology planning at DENSO International America, Pala holds 30 patents. He can be reached at.

高空间照明均匀度植物光源系统的设计

高空间照明均匀度植物光源系统的设计

Multimodal Testing Reveals Subclinical Neurovascular Dysfunction in Prediabetes, Challenging the Diagnostic Threshold of Diabetes

Background: There is growing evidence that small nerve fibre and retinal neurovascular damage occur in prediabetes before the onset of type 2 diabetes. Methods: Participants with normoglycaemia, prediabetes or type 2 diabetes underwent corneal confocal microscopy (CCM), electrochemical skin conductance (ESC), optical coherence tomography angiography (OCT-A), and handheld electroretinography (ERG) measurements. Findings: Seventy-five participants with normoglycaemia (n=20), prediabetes (n=29) and type 2 diabetes (n=26) were studied. Compared with normoglycaemia, mean peak ERG amplitudes of retinal responses at low (16 Td·s: 4·05 µV, 95% confidence interval (CI) 0·96-7·13) and high (32 Td·s: 5·20 µV, 95% CI 1·54-8·86) retinal illuminance were lower in prediabetes, as were OCT-A parafoveal vessel densities in superficial (0.051 pixels/mm2, 95% CI 0·005-0·095) and deep (0·048 pixels/mm2, 95% CI 0·003-0·093) retinal layers. There were no differences in CCM or ESC measurements between these two groups. Correlations between HbA1c and peak ERG amplitude at 32 Td·s (r=-0.256, p=0·028), implicit time at 32 Td·s (r=0·422, p=0·0002) and 16 Td·s (r=0·327, p=0·005), OCT parafoveal vessel density in the superficial (r=-0·238, p=0·049) and deep (r=-0·3, p=0·017) retinal layers, corneal nerve fibre length (CNFL) (r=-0·293, p=0·017), and hand ESC (r=-0·244, p=0·035) were observed. HOMA-IR was a predictor of CNFD (β=-0·94, 95% CI -1·66 to -0·21, p=0·012) and CNBD (β=-5·02, 95% CI -10·01 to -0·05, p=0·048). Interpretation: The diagnosis of diabetes is based on historical data showing emergent retinopathy on fundus examination; newer tests reveal abnormal retinal neurovascular structure (OCT-A) and function (ERG) occurring before retinopathy. Funding: This research received no funding support. Declaration of Interests: None of the authors have any relevant financial disclosures to declare. LKC Technologies Inc. and Impeto Medical Inc. provided free use of the RETeval and SUDOSCAN devices, respectively, for this study. CB is part-funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at The Royal Marsden NHS Foundation Trust and the Institute of Cancer Research, London. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. Ethics Approval Statement: This study adhered to the Declaration of Helsinki (2008) and was approved by an independent National Health Service Research Ethics Committee in November 2018 (REC ID: 18/LO/2126). Written informed consent was obtained from all participants.

高空间照明均匀度植物光源系统的设计

高空间照明均匀度植物光源系统的设计

Stable bright perovskite nanoparticle thin porous films for color enhancement in modern liquid crystal displays

Cesium-lead halide perovskite nanoparticles are a promising class of luminescent materials for color and efficient displays. However, material stability is the key issue to solve before we can use these materials in modern displays. Encapsulation is one of the most efficient methods that can markedly improve the stability of perovskite nanoparticles against moisture, heat, oxygen, and light. Thus, we urgently need a low-cost, reliable, and device-compatible encapsulation method for the integration of nanomaterials into display devices. Here, we propose a facile encapsulation method to stabilize perovskite nanoparticles in thin polymer porous films. Using porous polymer films, we achieved good photoluminescence stability in the harsh environment of high temperature, high humidity and strong UV illumination. The good UV stability benefitted from the unique optical properties of the porous film. Besides, we observed photoluminescence enhancement of CsPbBr3 nanoparticle films in a high humidity environment. The stable CsPbBr3 nanoparticle thin porous film provides high brightness (236 nits) and great color enhancement for LCDs and is characterized by simple fabrication with easy scalability, thus it is very suitable for modern LCDs.

Wireless Sensor Acquisition of Human Motion Parameters Based on Blockchain

With the rapid development of intelligent technology, people’s lives have gradually entered the era of information and intelligence. Traditional vision‐based and sensor‐based human motion detection methods have shortcomings such as high illumination requirements, difficulty in preserving privacy, and poor portability. The wireless sensor detection method based on a wireless network can overcome the shortcomings of these methods, so it has become a hot research direction. Human motion parameters are very important data. If leaked, it may cause unimaginable harm to individuals. Blockchain technology is an emerging technology in the field of information technology. Its decentralized nature, distributed storage, and data is not easy. The modification provides a feasible solution for us to realize the data upload. Combining the advantages of wireless sensing and blockchain technology, this paper proposes a method of wireless sensing collection of human motion parameters based on blockchain, and designs a human motion recognition system. The experiment found that under the experiments given in this article, the traditional accuracy rate of sensor data collection is 71.82%, and the accuracy rate of the wireless sensing collection method of human motion parameters based on the blockchain in this article has reached 95.31%, which verifies the effectiveness and superiority of the system designed in this article.

Study on Visual Acuity according to the Illuminance in Presbyopes Wearing Center-Near Multifocal Contact Lenses

Purpose : We investigated the changes in visual acuity and visual acuity according to illuminance in presbyopes wearing multifocal contact lenses.Methods : The subjects were 28 presbyopes (55.39±4.25 years) with a corrected visual acuity of 0.8 or more and astigmatism of less than 0.75 D. The Center-Near Multifocal contact lenses were worn in the period of 2 weeks for adaptation. The illuminance of test room was set to 1,000, 100, and 10 lx. The pupil size was measured at 3 m, and 40 cm with a pupil ruler when wearing multifocal contact lens (MFCL). Visual acuity at far and near was measured with high and low contrast ETDRS (Early Treatment Diabetic Retinopathy Study) chart.Results : When wearing MFCLs, high and low contrast visual acuity significantly increased as the illuminance increases at far and near distance (p 0.050), near visual acuities at 100 and 10 lx were significantly decreased (p<0.050) compared with spectacles. In 10 lx of low indoor illuminance with additional lamp, both near high and low contrast visual acuities were improved significantly (p<0.050).Conclusion : When wearing MFCLs, visual acuity was greatly affected by the illuminance, and the visual acuity in high illuminance condition was not different with spectacles. It was revealed that the additional near lamp could improve the visual acuity in dark indoor condition.

The lichen genus Lepraria Ach. (Stereocaulaceae, lichenized Ascomycota) in Romania

Introduction. The genus Lepraria includes diffuse or indefinitely delimited species, always sterile, Lendemer (1) naming it „the most unusual member of the sterile lichen crusts”. According to Tonsberg (2), the leprarioid state appeared as an adaptation to a substrate characterized by dry surfaces, in sites with high humidity and low illumination. The thallus is leprose with an entirely sorediate surface. The lack of fruiting bodies has made the lichens from this group among the least known and studied for a long time. The increase in the number of studies on sterile crustose lichens in recent period has led to an increase in the number of accepted species of the genus Lepraria. The information on the genus Lepraria is not uniformly distributed, the current checklist describes only two species, L. caesioalba and L. finkii in Romania. The recent appearance of several studies that indicate the presence in Romania of other species of the genus mentioned, created the motivation of this study. &#x0D; Material and methods. This study is based on material from the Babes-Bolyai University (CL) herbaria in Cluj-Napoca, Romania and literature data. For 13 species, specimens have been examined.&#x0D; Results. The key for the species of genus Lepraria is proposed, adapted from Wirth (3). The species distribution maps in Romania are given.&#x0D; Conclusions. Fifteen Romanian species are revised, Lepraria eburnea, L. ecorticata, L. umbricola were reported from two locations, L. neglecta was found only in one location. Most widely distributed species in Romania seems to be L. finkii and L. membranacea.

Assessing the Performance of RGB-D Sensors for 3D Fruit Crop Canopy Characterization under Different Operating and Lighting Conditions.

The use of 3D sensors combined with appropriate data processing and analysis has provided tools to optimise agricultural management through the application of precision agriculture. The recent development of low-cost RGB-Depth cameras has presented an opportunity to introduce 3D sensors into the agricultural community. However, due to the sensitivity of these sensors to highly illuminated environments, it is necessary to know under which conditions RGB-D sensors are capable of operating. This work presents a methodology to evaluate the performance of RGB-D sensors under different lighting and distance conditions, considering both geometrical and spectral (colour and NIR) features. The methodology was applied to evaluate the performance of the Microsoft Kinect v2 sensor in an apple orchard. The results show that sensor resolution and precision decreased significantly under middle to high ambient illuminance (>2000 lx). However, this effect was minimised when measurements were conducted closer to the target. In contrast, illuminance levels below 50 lx affected the quality of colour data and may require the use of artificial lighting. The methodology was useful for characterizing sensor performance throughout the full range of ambient conditions in commercial orchards. Although Kinect v2 was originally developed for indoor conditions, it performed well under a range of outdoor conditions.

Illumination correction via support vector regression based on improved whale optimization algorithm

AbstractVariations in illumination lead to serious errors in the evaluation of chromatic aberration. We propose an illumination correction model based on the opposition‐based learning improved whale optimization algorithm for support vector regression optimization, named "OBL‐IWOA‐SVR." Because the initial population quality of the whale optimization algorithm has a significant impact on the solution speed and accuracy, the Opposition‐based learning strategy is adopted in this article to mix the original population and its opposite individuals and select the best as the new population, replacing the random initialization to generate a more suitable initial population. This increases the diversity of the population and thus overcomes the impact of the quality of the initial population on the algorithm performance. Secondly, the proposed algorithm adopts the adaptive weight and the convergence factor based on the variation of the cosine law to balance the algorithm's global exploration ability and local development ability and enhance the convergence accuracy. Finally, the algorithm utilizes good global searching ability to optimize the penalty factor and nuclear parameters and obtains the optimal support vector machine parameter combination to construct the illumination correction model OBL‐IWOA‐SVR accurately and robustly. Experimental results show that the illumination correction model proposed in this article is found superior to other models in significance analysis: the root mean square error of the proposed model is 0.0173, the smallest of all illumination correction models. Furthermore, the model exhibits good stability and high illumination estimation accuracy.

CAMP-Dependent Regulation of the Phototransduction Cascade in Cones

Retinal photoreceptors – cones and rods – are able to undergo light adaptation over a wide range of illumination levels due to a complex of regulatory mechanisms. Among these, the best studied are calcium feedback circuits, which can explain about 50% of the actual regulation of light sensitivity. There are other regulatory mechanisms also able to adjust photoreceptor light responses depending on the illumination level, in particular regulation of the phototransduction cascade through the diurnal rhythm. During the dark phase of the diurnal cycle, cAMP levels in photoreceptors increase and rod sensitivity increases, which can be regarded as an adaptive action. In the case of cones, which operate at high illumination levels and make virtually no contribution to vision in twilight conditions, the increase in sensitivity in the dark phase may not have adaptive value. We report here our studies of how changes in [cAMP]in affect the operation of the phototransduction cascade in carp cones. Increases in [cAMP]in were obtained by incubating cells with the adenylate cyclase activator forskolin. Forskolin was found to slow both phases – the rise phase and the descending phase – of the light response in cones. As a result, cones, in contrast to rods, did not respond to forskolin with increases in light sensitivity but showed an almost two-fold reduction in the dark current. Thus, the reaction of the cone phototransduction cascade to increases in [cAMP]in was significantly different from the reaction in rods. This effect of [cAMP]in in cones may also have adaptive value – not in the form of increased sensitivity but as a reduction in the metabolic load on cells not functioning in the dark phase.

Land cover mapping with ultra‐high‐resolution aerial imagery

Land cover mapping with ultra‐high‐resolution aerial imagery

The effect of light attractor color in pelagic longline fisheries

Improving the selectivity of the fishing gear is one of the most promising methods to mitigate deleterious impacts of longline fisheries upon bycatch species. Light lures have recently become widespread in epipelagic longline fisheries since they increase the catch rates of valuable target species such as swordfish and tunas. Yet, little is known about their effect upon the incidence of bycatch. Here, we compared the catchability of target and bycatch species in a pelagic longline fishery targeting swordfish and tunas equipped with light attractors with three different colors to ascertain if any of the light attractor colors would enhance the selectivity of the fishing gear. A total of 3488 individuals were caught across 57 fishing sets. The proportion of target species to bycatch species was high (58–65 %) in each color treatment. Overall, green attractors (peak wavelength at 525 nm) exhibited the highest catch rates of target species, but they were also responsible for the highest incidence of bycatch, rendering 73 % and 82 % of the blue shark and sea turtle catch, respectively. Blue (peak wavelength at 465 nm) and white attractors caught significantly less individuals of both target and bycatch species. Further, significant interactions between light attractor color and the intensity of lunar illumination were observed for most species analyzed. Differences in the catchability of bycatch such as blue sharks and white marlins across attractor color treatments were more conspicuous at high lunar illumination levels (i.e. full moon periods), when white attractors rendered the lowest catch of these taxa. In contrast, the catchability of target species such as swordfish, yellowfin tuna and albacore showed greater differences between treatments at low illumination levels (i.e. new moon periods). The observed differences in the performance of the three light attractor colors across the lunar cycle might provide an opportunity to mitigate bycatch incidence in longline fisheries. Yet, further research is required to fully understand the combined effects of light lures and lunar illumination on the behavioral responses of pelagic species.

Light-induced reversal of ion segregation in mixed-halide perovskites.

Bandgap instability due to light-induced phase segregation in mixed-halide perovskites presents a major challenge for their future commercial use. Here we demonstrate that photoinduced halide-ion segregation can be completely reversed at sufficiently high illumination intensities, enabling control of the optical bandgap of a mixed-halide perovskite single crystal by optimizing the input photogenerated carrier density. We develop a polaron-based two-dimensional lattice model that rationalizes the experimentally observed phenomena by assuming that the driving force for photoinduced halide segregation is dependent on carrier-induced strain gradients that vanish at high carrier densities. Using illumination sources with different excitation intensities, we demonstrate write-read-erase experiments showing that it is possible to store information in the form of latent images over several minutes. The ability to control the local halide-ion composition with light intensity opens opportunities for the use of mixed-halide perovskites in concentrator and tandem solar cells, as well as in high-power light-emissive devices and optical memory applications.

Effect of membrane blocking on attached cultivation of microalgae

Membrane blocking is of great importance to nutrients transfer and illumination in attached cultivation of algae, which subsequently affects the biomass and nutrients production of algal biofilm. Accordingly, a vertical-algal-biofilm (VAB) with cellulose acetate (CA) membranes with pore size of 0.45, 1.2, 2.0, and 3.0 μm is settled to study the effect of membrane blocking on attached cultivation of microalgae. According to the results, the algae production is independent of the roughness, hydrophilicity, and surface free energy of membranes because the VAB is inoculated via filtration-on method in this work. Nevertheless, the algae productivity of first-cultivation on VABs increases to 5.02 g/m2. day when the pore size of CA membrane increases to1.2 μm, while it decreases to 4.5 g/m2. day on VABs with CA-3.0 due to the complete blocking of CA membranes by algae cells. The growth rates of first-cultivation and re-cultivation are well fitted by a logistic model and a linear model, respectively. The total lipids contents of microalgae on different CA membranes are affected by pore size due to the variations of nutrients transfer resistance and light intensity under different membrane blocking models. A maximum total lipids content of algae biomass cultivated on VABs with CA-1.2 is about 23.74% due to the nitrogen starvation and high illumination intensity under intermediate blocking model. Therefore, the attached cultivation of algae on VABs under intermediate blocking model is much favorable for algal biomass and lipid production.

A high performance integrated readout circuit for wavefront sensors

This work presents an integrated pixel topology that promises to offer superior performance in a Hartmann–Shack Wavefront Sensor (WFS) with an orthogonal array of Quad Cells serving as Position-Sensitive Detectors. The readout integrated circuit for each photodiode is fully compliant to any standard CMOS microelectronics technology and is advantageously tolerant to high background illumination levels whereas maintaining both high linearity and high sensitivity. To assess the operation of this pixel on the focal-plane array of the WFS, we developed a computational platform encompassing a full detection chain comprising wavefront sampling, photodetection, electronic circuitry and wavefront reconstruction. It couples an algorithm written in C to SPICE (Simulated Program with Integrated Circuits Emphasis). The platform is technology agnostic and flexible, enabling easy modification to represent different detection or reconstruction methods. The results obtained with the proposed pixel have been compared to those obtained with a conventional pixel in CMOS image sensor.

Femtosecond electronic structure response to high intensity XFEL pulses probed by iron X-ray emission spectroscopy

We report the time-resolved femtosecond evolution of the K-shell X-ray emission spectra of iron during high intensity illumination of X-rays in a micron-sized focused hard X-ray free electron laser (XFEL) beam. Detailed pulse length dependent measurements revealed that rapid spectral energy shift and broadening started within the first 10 fs of the X-ray illumination at intensity levels between 1017 and 1018 W cm-2. We attribute these spectral changes to the rapid evolution of high-density photoelectron mediated secondary collisional ionization processes upon the absorption of the incident XFEL radiation. These fast electronic processes, occurring at timescales well within the typical XFEL pulse durations (i.e., tens of fs), set the boundary conditions of the pulse intensity and sample parameters where the widely-accepted ‘probe-before-destroy’ measurement strategy can be adopted for electronic-structure related XFEL experiments.