Luminescent Cavity Design for High Ambient Contrast Ratio, High Efficiency Displays

A key display characteristic is its efficiency (emitted light power divided by input power). While display efficiencies are being improved through emissive (e.g., quantum dot and organic light emitting display (OLED) designs1,2, which remove the highly inefficient color filters found in traditional liquid crystal displays (LCDs)3,4, polarization filters, which block about 50% of the light, remain required to inhibit ambient light reflection. We introduce a luminescent cavity design to replace both the color and polarization filters. Narrow-band, large Stokes shift, CdSe/CdS quantum dot emitters are embedded in a reflective cavity pixel element with a small top aperture. The remainder of the top surface is coated black reducing ambient light reflection. A single pixel demonstrates an extraction efficiency of 40.9% from a cavity with an 11% aperture opening. A simple proof-of-concept multi-pixel array is demonstrated.

Inter-eye Differences in Ocular Biometric Parameters of Concomitant Exotropia

Purpose: To evaluate the ocular biometric parameters in patients with constant and intermittent exotropia by the measurement of swept-source optical coherence tomography (SS-OCT) optical biometer OA-2000 and comparing it with the normal control subjects.Design: Cross-sectional case-control study.Participants: Fifty-five constant and 24 intermittent patients with exotropia with central fixation and 77 orthotropic normal control participants aged 4–18 years old.Methods: Non-contact and high-resolution optical biometric OA-2000 measurements were conducted under uniform ambient light conditions. The statistical analysis included intraclass correlation coefficient (ICC), Bland-Altman plot, and independent t-tests.Main Outcome Measures: Spherical equivalent (SE), ocular biological parameters such as pupil diameter (PD), anterior chamber depth (ACD), lens thickness (LT), and axial lengths (AL). The absolute values of inter-eye differences for SE, PD, ACD, LT, and AL were recorded as AnisoSE, AnisoPD, AnisoACD, AnisoLT, and AnisoAL, respectively.Results: AnisoSE (0.878 vs. 0.577, P = 0.019), AnisoAL (0.395 vs. 0.208, P = 0.001), AnisoACD (0.060 vs. 0.032, P < 0.001), AnisoLT (0.060 vs. 0.031, P = 0.002), and AnisoPD (0.557 vs. 0.340, P = 0.002) were significantly larger in concomitant patients with exotropia. The SE, AL, ACD, LT, and PD showed excellent binocular correlation with ICC values that ranged from 0.943 to 0.987 in control participants and from 0.767 to 0.955 in concomitant exotropia patients. Bland-Altman plots showed the wider range of agreement in patients with concomitant exotropia than the control participants (SE: 5.0288 vs. 3.3258; AL: 2.2146 vs. 1.3172; ACD:0.3243 vs. 0.1682; PD: 2.4691 vs. 1.9241; and LT:0.3723 vs 0.1858).Conclusion: Patients with concomitant exotropia showed larger inter-eye differences in SE, ACD, LT, PD, and AL. Advice should be given to suspicious children to avoid or delay the development of concomitant exotropia.

Photo-Oxidation of Therapeutic Protein Formulations: From Radical Formation to Analytical Techniques

UV and ambient light-induced modifications and related degradation of therapeutic proteins are observed during manufacturing and storage. Therefore, to ensure product quality, protein formulations need to be analyzed with respect to photo-degradation processes and eventually protected from light exposure. This task usually demands the application and combination of various analytical methods. This review addresses analytical aspects of investigating photo-oxidation products and related mediators such as reactive oxygen species generated via UV and ambient light with well-established and novel techniques.

PulseEdit: Editing Physiological Signal in Facial Videos for Privacy Protection

Recent studies have shown that physiological signals can be remotely captured from human faces using a portable color camera under ambient light. This technology, namely remote photoplethysmography (rPPG), can be used to collect users' physiological status who are sitting in front of a camera, which may raise physiological privacy issues. To avoid the privacy abuse of the rPPG technology, this paper develops PulseEdit, a novel and efficient algorithm that can edit the physiological signals in facial videos without affecting visual appearance to protect the user's physiological signal from disclosure. PulseEdit can either remove the trace of the physiological signal in a video or transform the video to contain a target physiological signal chosen by a user. Experimental results show that PulseEdit can effectively edit physiological signals in facial videos and prevent heart rate measurement based on rPPG. It is possible to utilize PulseEdit in adversarial scenarios against some rPPG-based visual security algorithms. We present analyses on the performance of PulseEdit against rPPG-based liveness detection and rPPG-based deepfake detection, and demonstrate its ability to circumvent these visual security algorithms.

Effect of TiO2 Nanoparticles on the Yield and Photophysiological Responses of Cherry Tomatoes during the Rainy Season

The rainy season occurs mainly from June to July in Korea, and this season causes insufficient ambient light intensity for the growth of cherry tomato in a greenhouse. Titanium dioxide (TiO2), as a photocatalyst, is known to affect photosynthesis in plants. This study was carried out to investigate the influence of TiO2 foliar spray application on the yield and photophysiological responses of cherry tomato under low ambient light intensity during the rainy season in a greenhouse. Cherry tomato plants were treated with 100 mg·L−1 TiO2 (T1) or 200 mg·L−1 TiO2 (T2) nanoparticle suspension on 26 June. The control group was not treated with TiO2. In the O–J phase of the OJIP transient under a cloudy day (2 July), the slope in the control and T1 groups rose more sharply than that in the T2 group. Conversely, on a clear day (10 July), the J–I phase of the T2 group sharply increased compared to that of the control and T1 groups. On a cloudy day with low ambient light intensity, the rate of electron transport flux from QA to QB per photosystem II reaction center (ET0/RC) and carbon dioxide (CO2) fixation of TiO2-treated plants were increased compared to those of the control. However, on a clear day of high light intensity, the ET0/RC and CO2 fixation of the T2 group were lower than those of the control and Tl groups. The yield of fruit was increased in the T1 group over that in other treatments. TiO2 treatment reduced the size of the fruit and delayed the ripening time, but greatly increased the fruit hardness. These results suggest that setting the concentration and supply amount of TiO2 nanoparticles suitable for various environmental conditions should be prioritized in order to improve the effect of TiO2 nanoparticles in tomato cultivation.

INVESTIGATING LIGHT AND CRIME USING AMBIENT LIGHT LEVEL

A recent study investigated the influence of lighting on crime by considering the effect of change in ambient light level on crimes recorded in three US cities for the ten-year period 2010 to 2019. The results suggested a significant increase in robbery after dark, but did not suggest significant change in for any other type of crime. The current study was conducted to validate this by considering crimes recorded in three different US cities. This analysis confirmed the statistically significant increase in robbery after dark. These data do not suggest that change in ambient light level has a practically relevant effect on overall crime counts: in other words, the potential benefit of lighting for crime reduction is limited.

Laboratory studies of suspended particle volume concentration in atmosphere using a smartphone

The article presents the results of laboratory studies of the effect of volume concentration of suspended particles in contrast to the luminous slits image obtained by smartphone cameras of SAMSUNG Galaxy A3 and Honor 8 Lite. Experimentally it was found that a pattern of change in contrast to the luminous slits image from the volumetric concentration of suspended particles appears under ambient light. The pattern of contrast change can be expressed by an exponential function. The correlation coefficient is 0.97. Cigarette smoke was used as suspended particles.