Luminance Levels Research Articles

Blind quality index for tone-mapped images based on luminance partition

Tone-mapping operators (TMOs), which are designed to convert high dynamic range (HDR) images to standard low dynamic range (LDR) images for displaying on conventional devices, have gained extensive attention recently. The quality of tone-mapped images generated by different TMOs varies significantly, which depend upon the image contents and the parameter settings. A quality index that can accurately evaluate the performances of TMOs is thus highly needed. With this motivation, this paper presents a blind quality index based on luminance partition for tone-mapped images. It is based on the fact that the Human Visual System (HVS) has different sensitivities to image regions with different luminance levels. Specifically, two adaptive thresholds are first employed to segment an image into the dark, bright and normal areas. Then, we calculate the quality-aware features from different luminance areas: 1) local entropy feature is extracted from the dark and bright areas to measure the information loss due to the overexposure or underexposure during the tone mapping process; 2) local colorfulness feature is extracted from the normal area to evaluate the reproduction of colors. With the consideration that the perception of image quality depends on the combined effects of the salient local distortion and global quality degradation, the global contrast feature is also calculated and integrated for better evaluation performance. Moreover, to take advantage of the hierarchical characteristic of the HVS, all features are calculated under a multi-resolution framework. Eventually, the extracted features are mapped into an objective quality score based on the random forest regression. The proposed metric is shown to outperform those state-of-the-art metrics according to extensive experiments conducted on two publicly available databases.

The effects of physical luminance on colour discrimination in dogs: A cautionary tale

Due to the composition of the cone photoreceptors in the retina of dogs, it has been proposed they might demonstrate human-like red/green colour blindness. However, some assessments have shown that dogs may still be able to distinguish between red and green. This suggests that dogs may be differentiating between the two colours on the basis of their brightness. To further explore this issue, the present investigation tested dogs’ abilities to differentiate between two colours at different physical luminance levels. Seven dogs were trained on a simultaneous size discrimination task in which two circles were presented on a monitor. The colours of the circles were then varied such that dogs would choose one stimulus if they could discriminate between two colours and a different stimulus if they could not. Four experiments were conducted. The first presented dogs with yellow, blue, green, and red stimuli at their maximum red, green, and blue (RGB) values. All seven dogs were equally proficient at discriminating between red and green, yellow and blue, and black and white stimuli as no difference in performance was observed (p = 0.52). In Experiments 2–4, the four colours were presented with equal physical luminance across three different intensities. All seven dogs successfully discriminated between all four colours when the colours were isoluminant at 34.6 cd/m2 as no differences in performance was observed (p = 0.10). When presented with isoluminant stimuli at 41.9 cd/m2, a difference was observed between conditions, with the dogs failing to detect red stimuli presented on a green background compared to the achromatic controls (p = 0.03). When presented with stimuli at 49.3 cd/m2, a difference was again observed between conditions, but this time the dogs were unable to detect blue stimuli presented on a yellow background compared to the achromatic controls (p < 0.01). These findings demonstrate that luminance levels of stimuli can affect colour discrimination and what dogs are able to see on computer screens. These results have important implications in how cognition is studied in dogs through the use of presenting stimuli on monitors.

A Designer Synbiotic Attenuates Chronic-Binge Ethanol-Induced Gut-Liver Injury in Mice.

Gut dysbiosis and altered short-chain fatty acids are associated with ethanol-induced liver injury. SCFA are fermentation byproducts of the gut microbiota known to have many beneficial biological effects. We tested if a designer synbiotic could protect against ethanol-induced gut-liver injury. C57BL/6 female mice were exposed to chronic-binge ethanol feeding consisting of ethanol (5% vol/vol) for 10 days, followed by a single gavage (5 g/kg body weight) 6 h before euthanasia. A group of mice also received oral supplementation daily with a designer synbiotic, and another group received fecal slurry (FS); control animals received saline. Control mice were isocalorically substituted maltose dextran for ethanol over the entire exposure period. Ethanol exposure reduced expression of tight junction proteins in the proximal colon and induced hepatocyte injury and steatosis. Synbiotic supplementation not only mitigated losses in tight junction protein expression, but also prevented ethanol-induced steatosis and hepatocyte injury. Ethanol exposure also increased hepatic inflammation and oxidative stress, which was also attenuated by synbiotic supplementation. Mice receiving FS were not protected from ethanol-induced liver injury or steatosis. Results were associated with luminal SCFA levels and SCFA transporter expression in the proximal colon and liver. These results indicate supplementation with a designer synbiotic is effective in attenuating chronic-binge ethanol-induced gut-liver injury and steatosis in mice, and highlight the beneficial effects of the gut microbial fermentation byproducts.

Quantitative Assessment of Factors Affecting Visual Acuity by Changing the Luminance

In today's deregulated, the world continues its voyage towards modernization, and there is a great demand for inventive in product and services development, Visual acuity measurement has become one of the most successful clinical tests of visual function, Visual Acuity (V. A) Commonly refers to the clarity of vision, in another dimension, although V. A. is an estimate of the visual system's ability to resolve the details. However, the estimates of Visual acuity are taken by evaluating and measuring the eye's ability to realize and resolve varying sizes of letters and shapes in Snellen's chart. More recently attention has focused on the luminance of the visual acuity chart while it is essential to consider the overall room illumination during visual acuity measuring. It has commonly been assumed that the rise in ambient room illumination decreases the size of the pupil. A smaller pupil increases the depth of focus furthermore reductions the peripheral light rays that entering into the eye. Thus, the reduced pupil diameter great less spherical deviation and other higher order aberration, such as coma aberration. A clinician may achieve an artificially better estimate of visual acuity in a brightly-lit examination room. The aims of this study is to determine the factors affecting Visual Acuity by changing the luminance. Fourteen patients aged 19 to 24 years were chosen. Monocular visual acuity patients were assessed under five different luminance levels (different colors), and V. A was measured in the patients with each room color. The results showed that there is a clear difference in the measurement of V. A when the light was changed from color to another. The visual acuity of patients was assessed using the five different levels of illumination.

The Case for Further Advancing the Performance of Displays

Timo Kunkel Robert Wanat If there is one word to describe the difference between displays today and at the turn of the last century, it’s ubiquity. Modern consumers are surrounded by displays in their everyday lives, from the mobile devices we use when on the move to the TVs we enjoy at home for entertainment to the cinema screens we watch while socializing. It has become difficult to spend a day without once looking at a display. At the same time, expectations regarding the performance of these screens have steadily increased. This motivates display manufacturers to improve the capabilities of their devices and increasingly accommodate the challenges that changing viewing environments impose. Despite those complex challenges, amazing progress has been made in the last few decades in understanding how human visual perception works and how to use that information to create displays with improved image rendering consistency, accuracy, and overall capability. Though there is still a ways to go, the viewer experience today is more compelling than it has ever been. In this edition of Information Display, we pay close attention to high-performance displays, particularly in the Frontline Technology section. The articles there are centered around high dynamic range (HDR) imaging, which is currently one of the most prominent technological subfields. We believe that the lessons about the development of HDR pipelines that are explored in this issue will also benefit other high-performance display trends, such as AR/;VR, folding displays, 8K (see page 17 for an in-depth look at this trend), and very high framerate displays. The articles also focus on cutting-edge display technologies for home entertainment and automotive applications. Both of these contexts present different and sometimes unique challenges that have to be approached with a focus on how the visual system performs within the framework of the specific environment. One example discussed in the pages ahead is the effect of screen reflections and surround light, which are major challenges for image display and therefore need to be addressed as such. We can be even more specific with this illustration: Rendering accurate colors at very low ambient luminance levels is not as important for a TV display that is observed at high peak ambient illuminance levels–for example, a living room during the daytime—as colors rendered at very low luminance levels are likely less perceivable under this condition. Rather, in this case, the benefit from ambient compensation approaches that retarget those colors to improve their visibility exceeds that of having chromatic accuracy in the low luminances. However, accurate color rendering in low luminance levels becomes crucial in dark ambient environments, such as a living room at night or in a cinema. For automotive displays, accurate low-luminance appearance becomes even more important as there is a safety factor: Information must be communicated to drivers without distracting them while they’re in traffic. Many more concepts and examples are discussed in further detail. Ultimately, each article tells a part of the story and showcases how our industry is actively working on not only improving the status quo but also seamlessly rendering more accurate image quality, regardless of how consumers want to view their content. Timo Kunkel is a senior color and imaging researcher in the CTO office of Dolby Laboratories, Inc. His main areas of interest are advanced display and imaging technologies and exploring how we can continue to bring them closer to human perception. Kunkel can be reached at Timo.Kunkel@dolby.com. Robert Wanat is a senior color scientist for Dolby Laboratories, Inc. His work revolves around creating models of the human visual system that simulate visual perception and how it is affected by changing viewing conditions. Wanat can be reached at Robert.Wanat@dolby.com.

Correlation between Transient Pupillary Light Reflex and Retinal Function Impairment in Patients with Retinitis Pigmentosa.

Purpose To investigate the relationship between transient pupillary light reflex (PLR) and visual function in patients with retinitis pigmentosa (RP). Methods A retrospective study was performed with 137 eyes of 73 patients with RP. Transient pupillary light reflex was measured by the vision monitor system (MonColor; Metrovision, France). Dark-adapted transient PLRs were elicited by four specific levels of stimulus luminance (−5, −3, −1, and 0 log cd/m2, blue or white light). Best-corrected visual acuity (BCVA) was recorded based on Early Treatment Diabetic Retinopathy Study (ETDRS) acuity charts. Fixation stability and retinal sensitivity of radial 10° areas were measured with microperimetry. The retinal sensitivity (RS) was divided into central RS (fovea and radial 1° areas) and peripheral RS (radial 3° and 5° areas from the fovea). The patients were further classified into 2 groups (P1 > 75% and P1 < 75%) according to fixation stability. Spearman's correlation was performed to identify significant associations between BCVA, fixation stability, RS, and PLR. Results Under the stimuli of the same color light, relative pupillary constriction (RPC), latency, or velocity of constriction in the same patients was statistically different in multiple luminance, respectively. Under the same luminance, blue light induced greater RPC and velocity (except for −3 log cd/m2) than white light. Most patients showed varying degrees of threshold elevation and visual function deficiency. Besides, there was a statistically significant difference in the distribution of BCVA, MRS, or fixation stability under different thresholds. The correlation between pupillary constrictive area (PCA) and retinal sensitivity was mainly determined by the peripheral region. Moreover, patients with stable fixation showed a greater correlation between PCA and RS. Conclusion PLR induced by specific colors and luminance may serve as a promising clinical approach for assessing and monitoring rod function in advanced RP patients.

Design and Realization of White Quantum Dot Light-Emitting Electrochemical Cell Hybrid Devices.

The simple device architecture as well as the solution-based processing makes light-emitting electrochemical cells (LECs) a promising device concept for large-area flexible lighting solutions. The lack of deep-blue emitters, which are, at the same time, efficient, bright, and long-term stable, complementary to the wide variety of yellow-orange-emitting LECs, hampers the creation of white LECs. We present a hybrid device concept for the realization of white light emission by combining blue colloidal quantum dots (QDs) and an Ir-based ionic transition-metal complex (iTMC) LEC in a new type of white QD-LEC hybrid device (QLEC). By careful arrangement of the active layers, we yield light emission from both the blue QDs and the yellow iTMC emitter already at voltages below 3 V. The QLEC devices show homogeneous white light emission with high color rendering index (up to 80), luminance levels above 850 cd m-2, and a maximum external quantum efficiency greater than 0.2%.

Genetic characterization of aflap1 null mutation in Arabidopsis npq4 and pgr5 plants suggests that the regulatory role of FLAP1 involves the control of proton homeostasis in chloroplasts.

Precise control of the proton concentration gradient across thylakoid membranes (ΔpH) is essential for photosynthesis and its regulation because the gradient contributes to the generation of the proton motive force used for ATP synthesis and also for the fast and reversible induction of non-photochemical quenching (NPQ) to avoid photoinhibition and photodamage. However, the regulatory mechanism(s) controlling ΔpH in response to fluctuating light has not been fully elucidated. We previously described a new NPQ-regulatory chloroplastic protein, Fluctuating-Light-Acclimation Protein1 (FLAP1), which is important for plant growth and modulation of ΔpH under fluctuating light conditions. For this report, we further characterized FLAP1 activity by individually crossing an Arabidopsis flap1 mutant with npq4 and pgr5 plants; npq4 is defective in PsbS-dependent NPQ, and pgr5 is defective in induction of steady-state proton motive force (pmf) and energy-dependent quenching (qE). Both npq4 and npq4 flap1 exhibited similar NPQ kinetics and other photosynthetic parameters under constant or fluctuating actinic light. Conversely, pgr5 flap1 had recovered NPQ, photosystem II quantum yield and growth under fluctuating light, each of which was impaired in pgr5. Together with other data, we propose that FLAP1 activity controls proton homeostasis under steady-state photosynthesis to manipulate luminal acidification levels appropriately to balance photoprotection and photochemical processes.

The Choosing of Control Mode in Tunnel Lighting Intelligent Control System

Nowadays, more and more tunnel lighting intelligent control systems are applied into reality. For most control systems, there are five control modes. In this paper, the workings of the five control modes are expounded, and the conditions of adjusting the luminance level are obtained. Further, the luminance level and the power consumption of those control modes are compared. In order to choose the more suitable control mode, equipment cost, tunnel length and traffic volume are all considered for meeting equipment-lifetime and energy-saving. Combined lighting mode and automatic lighting mode are more suitable for most tunnels. Furthermore, the formula to forecast the lighting time using the minimum level and the difference of power-saving between combined lighting mode and automatic lighting mode are acquired. In the end, the options of the controls mode are listed for choosing.

Effects of pupillary responses to luminance and attention on visual spatial discrimination.

The optic quality of the eyes is, at least in part, determined by pupil size. Large pupils let more light enter the eyes, but degrade the point spread function, and thus the spatial resolution that can be achieved (Campbell & Gregory, 1960). In natural conditions, the pupil is mainly driven by the luminance (and possibly the color and contrast) at the gazed location, but is also modulated by attention and cognitive factors. Whether changes in eyes' optics related to pupil size modulation by luminance and attention impacts visual processing was assessed in two experiments. In Experiment 1, we measured pupil size using a constantly visible display made of four disks with different luminance levels, with no other task than fixating the disks in succession. The results confirmed that pupil size depends on the luminance of the gazed stimulus. Experiment 2, using similar settings as Experiment 1, used a two-interval forced-choice design to test whether discriminating high spatial frequencies that requires covert attention to parafoveal stimuli is better during the fixation of bright disks that entails a small pupil size, and hence better eyes' optics, as compared to fixating dark disks that entails a large pupil size, and hence poorer eyes' optics. As in Experiment 1, we observed large modulations of pupil size depending on the luminance of the gazed stimulus, but pupil dynamics was more variable, with marked pupil dilation during stimulus encoding, presumably because the demanding spatial frequency discrimination task engaged attention. However, discrimination performance and mean pupil size were not correlated. Despite this lack of correlation, the slopes of pupil dilation during stimulus encoding were correlated to performance, while the slopes of pupil dilation during decision-making were not. We discuss these results regarding the possible functional roles of pupil size modulations.

A new approach for medical image enhancement based on luminance-level modulation and gradient modulation

Abstract Medical images play a significant role in modern diagnosis but often suffer from non-uniformity and low-luminance, which always affects the results of diagnosis and even leads to misdiagnosis in real applications. To obtain a clear and accurate view of the medical images, a new method based on luminance-level modulation and gradient modulation (LM&GM) is proposed in this paper. LM&GM is a two-stage approach that, first, increases the visual perception using the luminance-level modulation (LM) operation by compressing the range of luminance levels of the input image, and second, uses the gradient modulation (GM) operation to enhance the details of the previous step result. Experimental results on CT images, X-ray images and MRI images from medical image datasets and quantitative analyses by structural similarity index measurement (SSIM), average gradient (AG), relative enhancement in contrast (REC) and information entropy (IE) demonstrate that the results of the proposed method are competitive and overwhelm those of the existing methods.

Naphthyl substituted triphenylamine derivatives as hole transporting materials for efficient red PhOLEDs

Naphthyl substituted triphenylamine and its derivatives with bromine atoms were synthesized and investigated. The respective glass transition temperatures of the materials were estimated to be in a range 65–137 °C, which can provide morphologically-stable amorphous films for applications in organic light emitting diodes. The compounds possess adequate ionization potentials (5.5–5.75 eV), high hole drift mobilities (>10−3 cm2/V·s) and suitable triplet energies (∼2.4 eV), which make them suitable hole transporting materials for use in red phosphorescent organic light-emitting diodes. A superior peak efficiency of 17.9% (31.4 cd/A and 26.9 lm/W) was achieved in a device having hole transporting layer of tris[4-(1-naphthyl)phenyl]amine. Furthermore, the device gave efficiencies of 17.7% and 16.6% recorded at luminance levels of 102 and 103 cd/m2. The efficiency drop from the maximum to the value recorded at the luminance of 103 cd/m2 for the device was only 7%.

Techniques for evaluating exposure in digital cameras

In this study we concentrate only on the techniques of evaluating the exposure in digital cameras, how to read and interpret each technique, and we will not touch the techniques of measuring light, incident or reflected and will not touch the factors of exposure control: aperture, Shutter speed, shutter angle, frame rate, neutral density, or iso sensitivity.Statement of the problem:The misreading of any of the exposure assessment techniques offered by digital cameras causes many problems that affect the quality of the final image and hinder the achievement of the objective of the image. These problems can be summarized in (1) Loss of detail in high light areas or shadows areas of the image. (2) Some parts of the image appear at a higher or lower brightness than the photographer / director of photography wants.Objectives:The aim of this study is to study the techniques of the exposure assessment offered by digital cameras to find out how to read and interpret each technique, so that we can judge accurately the levels of luminance produced by the digital camera of different parts of the image. Thus, the exposure or ratio of lighting contrast between the different parts of the scene being photographed can be changed to obtain the final result that achieves the objective of this photographic, cinematic or television picture.Methodology:the analytical descriptive method by studying how each of the techniques used by digital cameras to evaluate exposure in the digital image, so as to judge the actual levels of brightness produced by the camera for different parts of the scene.Conclusions: (1)All techniques used by digital cameras to assess exposure cannot be viewed separately from the scene being filmed, but must be checked during filming, compared to the original brightness levels of different parts of the scene. For example, the histogram may be clustered to the right, i.e., most pixels produce high levels of brightness. This diagram may reflect a correct exposure if most parts of the original scene are high-luminance, and the same scheme may express an over exposed image if the parts are high luminance from the original scene is a few and not predominant. In this case, the overall exposure to the image must be adjusted by shooting again: either by using a narrower lens aperture, or by reducing the intensity of the light falling on certain parts of the image. (2)For accurate photographing the parts of the scene being shot without loss of detail in both high light areas or low light areas, be careful to control the intensity of the light falling on each part of the scene so that the high lighting areas do not exceed the maximum level of assessment techniques, and low-light areas do not exceed the minimum level of any valuation techniques. (3) Since the missing details cannot be restored in the high-light areas of the scenes, while the details can be greatly improved in the shadows areas during post-processing. If the photographer / director of photography has any doubt about the validity of the exposure, try to reduce the exposure slightly to ensure that the details of the scene are preserved without any loss

Neural basis of location-specific pupil luminance modulation

Spatial attention enables us to focus visual processing toward specific locations or stimuli before the next fixation. Recent evidence has suggested that local luminance at the spatial locus of attention or saccade preparation influences pupil size independent of global luminance levels. However, it remains to be determined which neural pathways produce this location-specific modulation of pupil size. The intermediate layers of the midbrain superior colliculus (SC) form part of the network of brain areas involved in spatial attention and modulation of pupil size. Here, we demonstrated that pupil size was altered according to local luminance level at the spatial location corresponding to a microstimulated location in the intermediate SC (SCi) map of monkeys. Moreover, local SCi inactivation through injection of lidocaine reversed this local luminance modulation. Our findings reveal a causal role of the SCi in preparing pupil size for local luminance conditions at the next saccadic goal.

Efficient donor-acceptor-donor borylated compounds with extremely small ΔEST for thermally activated delayed fluorescence OLEDs

Borane-based complexes have attracted considerable attention as thermally activated delayed fluorescence (TADF) emitters because of their thermal stability, high fluorescence efficiency, and favourable carrier mobility. In this work, we provide a facile way for borylated compounds to enable the spatially adjacent electron donor and acceptor groups to form a near-orthogonal configuration, generating an extremely small energy gap between triplet and singlet excited states (ΔEST, ∼30 meV). We demonstrate here a new series of donor-acceptor-donor borylated compounds using functional acridan derivatives as the electron donors and dimesitylborane as the acceptor moieties, which easily generates an intramolecular charge transfer upon excitation. All compounds achieved strong TADF emission and were used as dopants to fabricate TADF OLEDs. Yellow-emitting devices A and B yielded maximum efficiencies of 7.6% (22.2 cd/A) and 10.1% (32.2 cd/A), respectively. Moreover, the green-emitting device C achieved a maximum efficiency of 19.3% (56.8 cd/A) and subsequently dropped to 18.2% (53.6 cd/A) at luminance levels of 102 cd/m2. Overall, the high electroluminescent (EL) efficiencies, together with mitigated efficiency roll-off, illustrate that these compounds have a high potential for EL applications.

Test-retest Variability of a Standardized Low Vision Lighting Assessment.

SIGNIFICANCESystematic lighting assessments should be part of low vision evaluations. The LuxIQ has gained popularity as an assessment tool, but its reliability has not been examined independently and is necessary for evidence-based vision rehabilitation.PURPOSEBesides magnification, improved lighting levels are a common intervention in reading rehabilitation for individuals with low vision. Determining the appropriate lighting can be a complex and time-consuming task. The LuxIQ is a portable lighting assessment tool that can be used to systematically measure lighting preferences; however, there is little independent evidence to support its reliability in low vision rehabilitation.METHODSOne hundred nine control subjects (age, 18 to 85 years) and 64 individuals with low vision (age, 27 to 99 years) adjusted both the luminance and color temperature parameters on the LuxIQ while viewing a sentence on the MNREAD at their preferred print size for continuous reading. After 30 minutes, they were asked to repeat the same measurements.RESULTSUsing Bland-Altman plots, test-retest variability was calculated using the limits of agreement (LOAs). For illuminance, the LOA width was 2806 lux for control subjects and 2657 lux for visually impaired participants. For color temperature, the LOA width was 2807 K for control subjects and 2364 K for those with a visual impairment. Difference scores were centered near zero, indicating overall accuracy.CONCLUSIONSThe measurement of lighting preference lacks the precision necessary for clinical utility, given that the LOA for luminance ranged more than 2600 lux, with normally sighted and low vision participants. Such variability translates into a range of approximately ±40 or 50 W in an incandescent light bulb, depending on the luminance level, making it clinically difficult to narrow down the options for evidence-based lighting recommendations. Next steps are to examine whether the reading behavior of low vision clients is positively affected by interventions that are based on LuxIQ recommendations.

Oral consumption of cinnamon enhances the expression of immunity and lipid absorption genes in the small intestinal epithelium and alters the gut microbiota in normal mice

Because cinnamon is orally ingested, its biological activity is likely to influence the small intestinal epithelium and the microbiota along the intestinal tract. We investigated small intestinal epithelial gene expression associated with immunity and lipid metabolism and measured IgA level in the small intestines and sera of mice fed cinnamon. We also analyzed microbial changes in the small and large intestines and feces using pyrosequencing of the 16 s rRNA gene. Cinnamon increased the gene expression of Muc2, RegIIIγ, and Pigr, which are necessary for defense against gut bacteria. It also increased the gene expression of GATA4 and Slc27a2, which are implicated in lipid absorption. Cinnamon increased luminal IgA level but not serum IgA and decreased the class Gammaproteobacteria (classified within the phylum Proteobacteria), particularly the genus Pseudomonas, in the large intestine. Cinnamon thus affected immunity and lipid absorption in the small intestinal epithelium and microbial composition in the intestines.

Intestinal P-glycoprotein exports endocannabinoids to prevent inflammation and maintain homeostasis.

Neutrophil influx into the intestinal lumen is a critical response to infectious agents, but is also associated with severe intestinal damage observed in idiopathic inflammatory bowel disease. The chemoattractant hepoxilin A3, an eicosanoid secreted from intestinal epithelial cells by the apically restricted efflux pump multidrug resistance protein 2 (MRP2), mediates this neutrophil influx. Information about a possible counterbalance pathway that could signal the lack of or resolution of an apical inflammatory signal, however, has yet to be described. We now report a system with such hallmarks. Specifically, we identify endocannabinoids as the first known endogenous substrates of the apically restricted multidrug resistance transporter P-glycoprotein (P-gp) and reveal a mechanism, which we believe is novel, for endocannabinoid secretion into the intestinal lumen. Knockdown or inhibition of P-gp reduced luminal secretion levels of N-acyl ethanolamine-type endocannabinoids, which correlated with increased neutrophil transmigration in vitro and in vivo. Additionally, loss of CB2, the peripheral cannabinoid receptor, led to increased pathology and neutrophil influx in models of acute intestinal inflammation. These results define a key role for epithelial cells in balancing the constitutive secretion of antiinflammatory lipids with the stimulated secretion of proinflammatory lipids via surface efflux pumps in order to control neutrophil infiltration into the intestinal lumen and maintain homeostasis in the healthy intestine.

The size of the attentional window when measured by the pupillary response to light

This study measured the size of the attentional window when attention is narrowly focused, using attentional modulation of the pupillary light response – pupillary constriction when covertly attending a brighter than darker area. This allowed us to avoid confounds and biases involved in relying on observers’ response (e.g., RT), which contaminated previous measurements of this window. We presented letters to the right and left of fixation, each surrounded by task-irrelevant disks with varying distances. The disks were bright on one side and dark on the other. A central cue indicated which letter to attend. Luminance levels were identical across trials. We found that pupil size was modulated by the disks’ luminance when they were 1° away from the attended letter, but not when this distance was larger. This suggests that the diameter of the attentional window is at least 2°, which is twice as large as that established with behavioral measurements.

Inner and Outer Retinal Contributions to Pupillary Light Response: Correlation to Functional and Morphologic Parameters in Glaucoma.

To evaluate in patients with primary open-angle glaucoma (POAG) the contribution of the inner and outer retinal photoreceptors to the pupillary light responses (PLRs) correlated with both functional (color vision and visual field perimetry) and morphologic (optical coherence tomography) parameters. In total, 45 patients with POAG and 25 healthy control participants were evaluated. The PLR was measured as pupil diameter with an eye tracker; stimuli were presented in a Ganzfeld. Pupil responses were measured monocularly, to 1 second blue (470 nm) and red (640 nm) flashes with -3, -2, -1, 0, 1, 2, and 2.4 log cd/m luminance levels. Color vision was evaluated with the Cambridge Color Test, visual field was measured by standard automatic perimetry, and retinal nerve fiber layer thickness was evaluated by optical coherence tomography. Patients with moderate and severe POAG have a significantly decreased PLR that depends on the severity of POAG, for both the 470 and 640 nm stimuli, revealing the reduction of the contributions of the rods, cones, and intrinsically photosensitive retinal ganglion cells to PLR. A significant loss of color discrimination along the blue-yellow axis was observed in all stages of POAG. Correlations among standard automatic perimetry, retinal nerve fiber layer thickness, Cambridge Color Test, PLR, and melanopsin parameters were found. The results provide evidence that in moderate and severe stages of POAG, both the inner and outer retinal contributions to PLR are affected. Also, a worsening in color vision was correlated with reduced PLR responses at high-intensity stimuli. These findings may enhance the clinical management of POAG patients.