T2FRF Filter: An Effective Algorithm for the Restoration of Fingerprint Images

Images captured in dim light are hardly satisfactory and increasing the International Organization for Standardization (ISO) for a short duration of exposure makes them noisy. The image restoration methods have a wide range of applications in the field of medical imaging, computer vision, remote sensing, and graphic design. Although the use of flash improves the lighting, it changed the image tone besides developing unnecessary highlight and shadow. Thus, these drawbacks are overcome using the image restoration methods that recovered the image with high quality from the degraded observation. The main challenge in the image restoration approach is recovering the degraded image contaminated with the noise. In this research, an effective algorithm, named T2FRF filter, is developed for the restoration of the image. The noisy pixel is identified from the input fingerprint image using Deep Convolutional Neural Network (Deep CNN), which is trained using the neighboring pixels. The Rider Optimization Algorithm (ROA) is used for the removal of the noisy pixel in the image. The enhancement of the pixel is performed using the type II fuzzy system. The developed T2FRF filter is measured using the metrics, such as correlation coefficient and Peak Signal to Noise Ratio (PSNR) for evaluating the performance. When compared with the existing image restoration method, the developed method obtained a maximum correlation coefficient of 0.7504 and a maximum PSNR of 28.2467dB, respectively.

Glow on Sharks: State of the Art on Bioluminescence Research

This review presents a synthesis of shark bioluminescence knowledge. Up to date, bioluminescent sharks are found only in Squaliformes, and specifically in Etmopteridae, Dalatiidae and Somniosidae families. The state-of-the-art knowledge about the evolution, ecological functions, histological structure, the associated squamation and physiological control of the photogenic organs of these elusive deep-sea sharks is presented. Special focus is given to their unique and singular hormonal luminescence control mechanism. In this context, the implication of the photophore-associated extraocular photoreception—which complements the visual adaptations of bioluminescent sharks to perceive residual downwelling light and luminescence in dim light environment—in the hormonally based luminescence control is depicted in detail. Similarities and differences between shark families are highlighted and support the hypothesis of an evolutionary unique ancestral appearance of luminescence in elasmobranchs. Finally, potential areas for future research on shark luminescence are presented.

Temporal Dynamics of Subjective and Objective Alertness During Exposure to Bright Light in the Afternoon for 5 h

Light can induce an alertness response in humans. The effects of exposure to bright light vs. dim light on the levels of alertness during the day, especially in the afternoon, as reported in the literature, are inconsistent. This study employed a multiple measurement strategy to explore the temporal variations in the effects of exposure to bright light vs. regular office light (1,200 lx vs. 200 lx at eye level, 6,500 K) on the alertness of participants for 5 h in the afternoon. In this study, 20 healthy adults (11 female; mean age 23.25 ± 2.3 years) underwent the Karolinska sleepiness scale (KSS), the auditory psychomotor vigilance test (PVT), and the waking electroencephalogram (EEG) test for two levels of light intervention. The results yielded a relatively lower relative delta power and a relatively higher beta power for the 1,200 lx condition in comparison with the 200 lx condition. However, the light conditions elicited no statistically significant differences in the KSS scores and performance with respect to the PVT. The results suggested that exposure to bright light for 5 h in the afternoon could enhance physiological arousal while exerting insignificant effects on subjective feelings and performance abilities relating to the alertness of the participants.

Low-Light Image Enhancement Based on Generative Adversarial Network

Image enhancement is considered to be one of the complex tasks in image processing. When the images are captured under dim light, the quality of the images degrades due to low visibility degenerating the vision-based algorithms’ performance that is built for very good quality images with better visibility. After the emergence of a deep neural network number of methods has been put forward to improve images captured under low light. But, the results shown by existing low-light enhancement methods are not satisfactory because of the lack of effective network structures. A low-light image enhancement technique (LIMET) with a fine-tuned conditional generative adversarial network is presented in this paper. The proposed approach employs two discriminators to acquire a semantic meaning that imposes the obtained results to be realistic and natural. Finally, the proposed approach is evaluated with benchmark datasets. The experimental results highlight that the presented approach attains state-of-the-performance when compared to existing methods. The models’ performance is assessed using Visual Information Fidelitysse, which assesses the generated image’s quality over the degraded input. VIF obtained for different datasets using the proposed approach are 0.709123 for LIME dataset, 0.849982 for DICM dataset, 0.619342 for MEF dataset.

Snowball Earth, population bottleneck and Prochlorococcus evolution

Prochlorococcus are the most abundant photosynthetic organisms in the modern ocean. A massive DNA loss event occurred in their early evolutionary history, leading to highly reduced genomes in nearly all lineages, as well as enhanced efficiency in both nutrient uptake and light absorption. The environmental landscape that shaped this ancient genome reduction, however, remained unknown. Through careful molecular clock analyses, we established that this Prochlorococcus genome reduction occurred during the Neoproterozoic Snowball Earth climate catastrophe. The lethally low temperature and exceedingly dim light during the Snowball Earth event would have inhibited Prochlorococcus growth and proliferation, and caused severe population bottlenecks. These bottlenecks are recorded as an excess of deleterious mutations accumulated across genomic regions and inherited by descendant lineages. Prochlorococcus adaptation to extreme environmental conditions during Snowball Earth intervals can be inferred by tracing the evolutionary paths of genes that encode key metabolic potential. Key metabolic innovation includes modified lipopolysaccharide structure, strengthened peptidoglycan biosynthesis, the replacement of a sophisticated circadian clock with an hourglass-like mechanism that resets daily for dim light adaption and the adoption of ammonia diffusion as an efficient membrane transporter-independent mode of nitrogen acquisition. In this way, the Neoproterozoic Snowball Earth event may have altered the physiological characters of Prochlorococcus , shaping their ecologically vital role as the most abundant primary producers in the modern oceans.

Effects of Night Illumination on Behavior, Body Mass and Learning in Male Zebra Finches

An increase in artificial night lighting has blurred the boundaries of day and night and transformed the natural day-night environment with alteration in the temporal niche of the animals. Male zebra finches were exposed to a dim light at night (dLAN) protocol (Light: dLAN, 12L = 200 lux: 12dLAN = 5 lux) with controls on darkness at night (Light: dark, 12L = 200 lux: 12D = 0 lux) for six weeks. We assayed sleep-wake, daily behaviors, mood, and cognition, as well as changes in physiological parameters. Dim light at night increased sleep frequency, delayed sleep onset, advanced awakening latency, and caused a reduction in total sleep duration. dLAN birds did not associate (physical association) with novel object and birds spent significantly lesser time on perch with novel object as compared to LD. In colour learning task, night illuminated birds took more time to learn and made more error, compared to LD. dLAN significantly altered the 24-h daily behavioral rhythm (amplitude and acrophase) of feeding, drinking, preening, and perch-hopping behavior. In particular, birds extended their feeding hours in the nighttime under dLAN, with no difference in total food intake. Birds under dLAN increased fattening and hence significantly increased body mass. Our results show that dim light at night altered feeding rhythm, caused decrease in sleep behavior, and negatively affected learning and memory performance in male zebra finches.

The Effect of Cognitive Behaviour Therapy on Sleep and Circadian Rhythm in Young College Students

The present study is to study the effect of cognitive behaviour therapy on various sleep parameters and circadian phase rhythmic in young college going adults. Fifty young college going adults were chosen from the MBBS and BDS students of King George's Medical University Lucknow, their polysomnography was conducted along with it salivary melatonin estimation was conducted to find the time of Dim light melatonin onset (DLMO), the subjects were administered cognitive behaviour therapy (CBT),after completing the sessions of cognitive behaviour therapy another Polysomnographic study and DLMO estimation was conducted, various sleep parameters were compared before and after the CBT. The study showed an improvement in the steep quality, a decrease in daytime sleepiness along with this total sleep time significantly increased, sleep efficiency also improved and there was a decrease in the REM sleep latency. The Dim light melatonin onset advanced for the subjects and the chronotype showed an inclination towards an earlier timings.

The endogenous circadian system worsens asthma at night independent of sleep and other daily behavioral or environmental cycles

Asthma often worsens at night. To determine if the endogenous circadian system contributes to the nocturnal worsening of asthma, independent of sleep and other behavioral and environmental day/night cycles, we studied patients with asthma (without steroid use) over 3 wk in an ambulatory setting (with combined circadian, environmental, and behavioral effects) and across the circadian cycle in two complementary laboratory protocols performed in dim light, which separated circadian from environmental and behavioral effects: 1) a 38-h “constant routine,” with continuous wakefulness, constant posture, 2-hourly isocaloric snacks, and 2) a 196-h “forced desynchrony” incorporating seven identical recurring 28-h sleep/wake cycles with all behaviors evenly scheduled across the circadian cycle. Indices of pulmonary function varied across the day in the ambulatory setting, and both laboratory protocols revealed significant circadian rhythms, with lowest function during the biological night, around 4:00 AM, uncovering a nocturnal exacerbation of asthma usually unnoticed or hidden by the presence of sleep. We also discovered a circadian rhythm in symptom-based rescue bronchodilator use (β2-adrenergic agonist inhaler) whereby inhaler use was four times more likely during the circadian night than day. There were additive influences on asthma from the circadian system plus sleep and other behavioral or environmental effects. Individuals with the lowest average pulmonary function tended to have the largest daily circadian variations and the largest behavioral cycle effects on asthma. When sleep was modeled to occur at night, the summed circadian, behavioral/environmental cycle effects almost perfectly matched the ambulatory data. Thus, the circadian system contributes to the common nocturnal worsening of asthma, implying that internal biological time should be considered for optimal therapy.

If You’re Happy and You Know it Stay Alert: The Effects of Lighting on Vigilance Performance and Affective State

Vigilance, or sustained attention tasks involve detecting critical signals, embedded amid more frequent neutral signals, over an extended period of time. A decline in performance, engagement, and arousal over time, as well as high workload and stress, are common outcomes of such tasks. Exposure to broad-spectrum or short wavelength bright light has been found to positively impact alertness, speed of information processing, and mood, but has not been extensively explored in the vigilance domain. The present study explored whether a light therapy lamp could mitigate the negative vigilance outcomes found in both performance and affective state. Results indicated that the therapy light did not prevent a decline in detection of critical signals over time, nor significantly impact workload, sleepiness, or subjective stress state compared to a dim light condition. However, mood questionnaire results suggest that lighting may impact separate constructs of arousal and tiredness, warranting further research.