Green Light Conditions Research Articles

Lignin-Derived Gold-Titanium Dioxide Nanophotocomposites as Potent Photoactivatable Probes for Microbial Inactivation.

The overuse of antibiotics has accelerated antibiotic resistance, and it is a significant global threat to public health. To combat the rising threat of drug-resistant microbes, antimicrobial photodynamic therapy (APDT) has emerged as a promising alternative therapeutic strategy. This study focuses on the synthesis of eco-friendly lignin-derived gold-titanium dioxide nanophotocomposites (L@Au-TiO2 NCs). Lignin was utilized as a sustainable precursor for the synthesis of L@Au-TiO2 NCs. The gold and TiO2 nanoparticles possess inherent photodynamic properties, and thus the developed L@Au-TiO2 NCs exhibit enhanced antimicrobial efficacy due to the synergistic combination of their attributes. The antimicrobial potential of the L@Au-TiO2 NCs was evaluated against various microbial strains (Escherichia coli, Bacillus megaterium, and Candida tropicalis) under dark and green light conditions. The outcome of this study highlights the promising potential of L@Au-TiO2 NCs for photodynamic antimicrobial applications. The L@Au-TiO2 nanophotocomposites could be explored in the fields of medicine and nanotechnology to introduce innovative ideas into the biomedical field.

Effects of different light qualities on embryonic development of Sepia pharaonis

To investigate the impact of different light qualities (red, blue, green, yellow, and white light) on the embryonic development of Sepia pharaonis, this experiment studied the effects of different light qualities on the timing of embryonic development, incubation period, hatching rate, malformation rate, weight of hatchlings, and survival rate on the 7th day after hatching. The findings demonstrated a significant influence of different light qualities on the embryonic development of S. pharaonis (P<0.05). Specifically, red and blue light led to increased occurrences of phenomena such as yolk surface cracking, cell autolysis, coagulation of cells in the animal pole, yolk sac edema, malformations in endoskeleton development, and decreased pigmentation and whitening of the body surface compared to the control group (white light). Conversely, green light showed a tendency to reduce these phenomena. The hatching rate and hatching cuttlefish weight were highest under green and yellow light conditions, with significantly greater survival rate on the 7th day after hatching compared to red, blue, and white light conditions. Furthermore, the malformation rate was notably lower under green light conditions compared to other light groups. Red and blue light conditions exhibited the shortest hatching periods, significantly outpacing other light groups. In conclusion, green light appears advantageous for enhancing hatching rate, the quality and health of hatched larvae, reducing malformation occurrences and embryonic mortality, and improving overall hatching quality.

Effects of visible light wavelength on development and demographic parameters of Phytoseiulus persimilis (Acari: Phytoseiidae)

Environmental factors, such as the wavelength of light, can have a crucial impact on mite development. Little is, however, known about the effect of visible light quality on demographic parameters of Phytoseiidae. We therefore conducted series of laboratory experiments in which development and reproduction of Phytoseiulus persimilis Athias-Henriot feeding on Tetranychus urticae Koch eggs was investigated under various light conditions (white, blue, green, yellow, and red light). The results revealed that different light wavelengths influenced each developmental stage, with the green light conditions promoting longest pre-adult development. The longevity of both male and female mites varied significantly across light wavelengths, with the shortest lifespan observed under red light. The highest mean total fecundity, 16 eggs per female, was observed under white light conditions. Population parameters (R0, r, and λ) were also highest under white light and decreased with increasing light wavelength. These findings suggest that light wavelength plays a significant role in development, survival, and reproduction of the predatory mite, with white light being identified as providing the best light conditions for commercial production of P. persimilis.

Effects of light quality and intensity on the juvenile physiological metabolism of Babylonia areolata

Babylonia areolata lives in bottom sediments during the day and emerges at night to forage. This study examined how different light qualities (blue, white, green, and red light) and intensities (0 and 2–32 μmol·m s−1) influence the growth and physiological activity of B. areolate juveniles. Changes in the activity of digestive enzymes, such as pepsin (PPS), lipase (LPS), and amylase (AMS), as well as energy metabolic enzymes, such as hexokinase (HK), pyruvate kinase (PK), lactic dehydrogenase (LDH) and succinic dehydrogenase (SDH), were also studied. The result showed that juveniles exhibited substantial variations under different light conditions. Specifically, the maximum bodyweight specific growth rates (SGR) under green, blue, red, and white light conditions were 3.56 ± 0.45 %·d−1, 3.03 ± 0.68 %·d−1, 3.01 ± 0.72 %·d−1 and 2.99 ± 0.73 %·d−1 at light intensities of 2 μmol·m−2·s−1, 4 μmol·m−2·s−1, 8 μmol·m−2·s−1 and 2 μmol·m−2·s−1, respectively. The shell length SGR, shell width SGR and body weight SGR in the dark group were not statistically different from those in the red light group at 2 μmol·m−2·s−1 (p > 0.05), while the body weight SGR of the dark group was significantly lower than that in other groups (p < 0.05). At the light intensity of 2 μmol·m−2·s−1, the activity of PPS in green and blue light was significantly higher than in red light (p < 0.05). The activity of HK in green light was considerably higher than that in darkness (p < 0.05), and there was no significant difference in the activity of LDH between the dark group and the red light group (p > 0.05), although the results of both groups were significantly higher than those of the blue and white light (p < 0.05). In addition, the activity of PPS, AMS, HK, PK, and LDH was considerably higher in darkness than in other light qualities (p < 0.05). Under different light qualities, the activity of all enzymes at the low light intensity was significantly higher than that at the high light intensity (p < 0.05), which coincided with growth characteristics. Therefore, blue and green light promoted the growth of juveniles at low light intensity (2 μmol·m−2·s−1), but darkness inhibited their growth. The findings of this study could be used as a foundation for optimizing lighting conditions and figuring out the optimum conditions for the growth and survival of B. areolata. Furthermore, this study could help explain how to control lighting conditions in real-world breeding situations.

Physiological Performance of Mimosa pudica L. under Different Light Quality and Photoperiods

In the present study, we examined the light quality and photoperiod-dependent physiological performance of Mimosa pudica. Plants were grown in pots under white, blue, green and red-light compositions under 12 h per day (12/12 h) and 24 h per day (24/0 h) for 12 days. After 12 days, the physiological parameters’ morphology, fresh weight, chlorophyll fluorescence and biochemical analyses, which include antioxidants, lipid peroxidation, pigment content and carbohydrate content were also measured. Necrosis was found in red, blue and green light and the plant was senesced at the end of the experiment. The blue 24-h light period showed the highest pigment and antioxidant content, whereas the lowest was observed in green light conditions. The OJIP curve was complete in white light, hence it was not completely formed in red, blue and green light. The phenomenological parameters also fluctuated in different light conditions. Photosynthesis ultimately results in starch content, which was highest in blue light and lowest in red light. Different monochromatic light qualities inhibited plant growth by reducing the activity of photosynthetic apparatus in plants. White light was more effective in driving photosynthesis and promoting the plant growth, while green and red light showed a suppressive effect on plants’ growth. The 24 h photoperiod was also accompanied by various spectra to reduce the plants’ growth. The results clearly indicate that the photoperiod and light spectrum must be considered before growing plants in a greenhouse.

Effect of different mixing modes on the abundance of Microcystis in Lake Taihu under green light.

Light and hydrodynamic force are important physical factors affecting growth of Microcystis. The most recent study found that green light has good effect in inhibiting growth of Microcystis. To understand the effect of mixing modes on Microcystis under the green light, we investigated the effects of continuous mixing and intermittent mixing on the abundance of Microcystis in Taihu Lake under field conditions. The study results found that abundance of Microcystis in control, intermittent mixing group, and continuous mixing group decreased 76.62%, 40.36%, and 95.18% on day 7 compared with that on day 1 in this experiment. At the end of the experiment, abundance percentages of diatoms and green algae to total phytoplankton abundance were 1.57% and 0.48% in control, 2.32% and 0.67% in intermittent mixing group, and 22.47% and 20.27% in continuous mixing group. The results indicated that continuous mixing favored the removal of Microcystis under green light conditions and was helpful for the growth of green algae and diatoms. The results provide a new approach for the control of Microcystis blooms.

Simulator assessment of innovative intersection designs on driver speeds and trajectories

Intersections are over-represented in crash statistics internationally, suggesting that treatments targeting intersections could substantially improve road safety. Aligning with a Safe Systems approach, several innovative intersection configurations have been proposed. We evaluated the effectiveness of five designs on reducing speed and modifying conflict angles using a driving simulator. The designs were 1) cut-through, 2) modified restricted squircle, 3) unrestricted squircle, 4) raised approach, and 5) raised intersection. For the higher speed green light condition, speed reductions for vehicles travelling straight through the intersection were seen for all five innovative designs on approach to the intersection and at critical conflict points within the intersection. Within the intersection specifically, speed reductions ranged from 1) 7–8 km/h for the modified restricted squircle, 2) 12.5–16.5 km/h for the unrestricted squircle, raised approach, and raised intersection, and 3) 15–19 km/h for the cut-through. In contrast, speeds for drivers turning right were either not substantially reduced (modified restricted squircle, unrestricted squircle, and raised intersection) or were increased (raised approach and cut-through). Beneficial modification of conflict angles were also observed at conflict points for three of the five designs: cut-through, and two variations of the squircle design. Innovative intersection designs may be effective in reducing intersection crash risk by reducing speeds and conflict angles.

The effects of different light storage conditions on volatile flavor compounds and sensory properties of melon fruit

Light can be invoked as a signal for improving metabolism and physiological state during plant storage. However, little is known about the effects of light on volatile flavor compounds and sensory properties during melon fruit storage, especially for different types of visible light. Fifty typical volatile flavor compounds, including 28 esters, 7 alcohols, 7 aldehydes, 4 ketones, 2 furans, 1 ether, and 1 pyrazine, were identified by gas chromatography–ion mobility spectrometry in melon fruit under blue light, black, green light, red light, and white light storage conditions. The total peak values of the flavor compounds were significantly higher in white light storage condition but significantly lower in black storage condition compared with the controls. A 5-day continuous sensory property study involving color, appearance, freshness, odor, and mouthfeel was performed. Total sensory scores were high in white light storage conditions but low in black storage conditions. The results were consistent with the previous detection results, and white light was found to be more conducive to melon storage. This study provides useful insights into the effects of light on flavor and sensory properties of melon fruit, as well as a possible way to extend melon fruit shelf life by visible light irradiation.

Monochromatic blue light not green light exposure is associated with continuous light-induced hepatic steatosis in high fat diet fed-mice via oxidative stress

Irregular light exposure is a newly identified environmental factor for the progression of lipid metabolism; however, the specific effect of light color exposure on lipid homeostasis remains unknown. Herein, 4-week-old male C57BL/6 J mice (n = 12) fed a high-fat diet (HFD) were exposed to a standard 12-h light: 12-h dark cycle (LD-WF) and a 24-h continuous monochromatic blue light (LL-BF), green light (LL-GF), or white light (LL-WF) condition for 12 weeks. LL-BF interfered with the expression of circadian genes in the hypothalamus and upregulated the plasma corticosterone (CORT) levels (p < 0.05) compared with LD-WF. Along with elevation of the CORT level, LL-BF enhanced glucocorticoid receptor synthesis, increased the Hsp90 mRNA level, reduced the antioxidant capacity, increased the production of ROS and MDA, and reduced the Pgc-1α mRNA level in the liver (p < 0.05). Furthermore, LL-BF disrupted the hepatic expression levels of genes involved in lipid metabolism, Acc and Hl, which further aggravated the hepatic steatosis status and significantly increased the liver pathological scores, TG, TC, IL-6, and TNF-α levels (p < 0.05). LL-BF consistently increased the body weight and incidence of dyslipidemia and lipid deposition. However, no difference was observed between LL-BF and LL-WF (p > 0.05). Surprisingly, LL-GF did not show any changes induced by LL-BF and LL-WF, and contrary to LL-BF, LL-GF and LD-WF showed no significantly differing changes (p > 0.05). Taken together, exposure to monochromatic blue light but not green light is associated with continuous light-aggravated hepatic steatosis in HFD-fed mice. The effect of continuous blue light exposure may be attributed to the disturbance of biological rhythm, increase in CORT secretion, induction of oxidative stress, and interference of the Acc and Hl levels in the liver.

Psychotherapeutic approach for the treatment of generalized anxiety disorder (GAD) improves outcome when delivered under specific (narrow band) green light condition. (P5-12.004)

Psychotherapeutic approach for the treatment of generalized anxiety disorder (GAD) improves outcome when delivered under specific (narrow band) green light condition. (P5-12.004)

Effects of zinc and iron on the abundance of Microcystis in Lake Taihu under green light and turbulence conditions.

Trace element is one of the important factors affecting the growth of Microcystis. The effects of zinc (0.4mg/L) and iron (2mg/L) on the abundance of Microcystis in Lake Taihu were investigated under continuous turbulence and green light conditions in a microcosm experiment. The study results showed that the abundance of Microcystis in the zinc treatment and the iron treatment group was 8.30% and 214% of that in the control group at the end of the experiment, respectively. The proportion of Cyanobacteria in the total phytoplankton biomass in the control, iron treatment, and zinc treatment group decreased from 99.99% at the beginning of the experiment to 13%, 18%, and 1% at the end of the experiment, respectively. At the end of the microcosm experiment, the phytoplankton community was dominated by Bacillariophyta in the control group, accounting for 63%, but it was dominated by Chlorophyta in the zinc treatment and the iron treatment group, accounting for 89% and 42%, respectively. The study results showed that under green light and turbulence, 0.4mg/L zinc remarkably decreased the abundance of Microcystis, but 2mg/L iron effectively increased the number of Microcystis and other algae. This research results provided a new idea for controlling Microcystis blooms.

Psychotherapeutic Approach for the Treatment of Generalized Anxiety Disorder (GAD): Within-Session Improved Outcome When Conducted Under Specific Narrow Band Green Light Conditions

Psychotherapeutic Approach for the Treatment of Generalized Anxiety Disorder (GAD): Within-Session Improved Outcome When Conducted Under Specific Narrow Band Green Light Conditions

Short-Term Exposure to Blue Light Shows an Inhibitory Effect on Axial Elongation in Human Eyes Independent of Defocus.

PurposeGiven the potential role of light and its wavelength on ocular growth, we investigated the effect of short-term exposure to the red, green, and blue light on ocular biometry in the presence and absence of lens-induced defocus in humans.MethodsTwenty-five young adults were exposed to blue (460 nm), green (521 nm), red (623 nm), and white light conditions for 1-hour each on 4 separate experimental sessions conducted on 4 different days. In each light condition, hyperopic defocus (3D) was induced to the right eye with the fellow eye experiencing no defocus. Axial length and choroidal thickness were measured before and immediately after the light exposure with a non-contact biometer.ResultsAxial length increased from baseline after red light (mean difference ± standard error in the defocussed eye and non-defocussed eye = 11.2 ± 2 µm and 6.4 ± 2.3 µm, P < 0.001 and P < 0.01, respectively) and green light exposure (9.2 ± 3 µm and 7.0 ± 2.5 µm, P < 0.001 and P < 0.001) with a significant decrease in choroidal thickness (P < 0.05, both red and green light) after 1-hour of exposure. Blue light exposure resulted in a reduction in axial length in both the eyes (−8.0 ± 3 µm, P < 0.001 in the defocussed eye and −6.0 ± 3 µm, P = 0.11 in the non-defocused eye) with no significant changes in the choroidal thickness.ConclusionsExposure to red and green light resulted in axial elongation, and blue light resulted in inhibition of axial elongation in human eyes. Impact of such specific wavelength exposure on children and its application in myopia control need to be explored.

Blue LED lighting improves the postharvest quality of tomato (Solanum lycopersicum L. cv. Zahide F1) fruits

Objective: The objective of this study was to investigate the effects of different wavelengths of LED lighting on the postharvest quality of tomatoes (Solanum lycopersicum L. cv. Zahide) during breaker harvest stages..&#x0D; Material and Methods: Harvested tomato fruits were placed on 500 g polystyrene foam dishes and wrapped with stretch film. They then were stored in 4±1ºC temperature and 85-90% relative humidity for 42 days under the red (R), blue (B), green (G) and white (W) LED light conditions. The fruits stored in the dark were used as control (C). &#x0D; Results: R and W LED treatments increased hue angle value, yellowness index value, and fruit firmness of tomatoes Blue LED lighting, also decreased electrolyte leakage that indicates delaying senescence. It was also found that blue and red LED lighting delayed fruit decay.&#x0D; Conclusion: As a conclusion, it could be satated that the blue LED lighting was found to be more effective than the red, white and green LED light in maintaining the quality of the tomatoes harvested at the breaking stage.

Railroad traffic light sensors to anticipate jams at junctions based on ATMega8

Traffic congestion is a problem that has long occurred in Indonesia, especially in big cities. Traffic congestion that occurs can cause various losses, one of which is time loss because it can only run at a very low speed. Then it will create a waste of energy, because going at low speed will require more fuel. Congestion is also able to increase the saturation of other road users, not only that traffic jams also have a bad impact on nature which causes air pollution. And there are many more impacts of traffic jams that can make traveling very uncomfortable. One of the locations of traffic jams often occurs on roads located around railroad crossings. Therefore, In this study, it is proposed to make a traffic light sensor adjacent to the train track to anticipate long traffic jams based on atmega8 and infrared sensors, with the stages of collecting data, recording transportation activities at the location of the jam, then designing a sensor device. The system built is to read the volume of vehicles on the road and prioritize the road with the highest volume of vehicles to get the green traffic light condition. Based on the results of the manufacture of infrared sensors and atmega8 can be tested to reduce the level of congestion at crossroads adjacent to the railroad.

The Role of Dopamine in Emmetropization Modulated by Wavelength and Temporal Frequency in Guinea Pigs.

PurposeWavelength and temporal frequency have been found to influence refractive development. This study investigated whether retinal dopamine (DA) plays a role in these processes.MethodsGuinea pigs were randomly divided into nine groups that received different lighting conditions for 4 weeks, as follows: white, green, or blue light at 0, 0.5, or 20.0 Hz. Refractions and axial lengths were measured using streak retinoscopy and A-scan ultrasound imaging. DA and its metabolites were measured by high-pressure liquid chromatography-electrochemical detection.ResultsAt 0 Hz, green and blue light produced myopic and hyperopic shifts compared with that of white light. At 0.5 Hz, no significant changes were observed compared with those of green or blue light at 0 Hz, whereas white light at 0.5 Hz induced a myopic shift compared with white light at 0 or 20 Hz. At 20 Hz, green and blue light acted like white light. Among all levels of DA and its metabolites, only vitreous 3, 4-dihydroxyphenylacetic acid (DOPAC) levels and retinal DOPAC/DA ratios were dependent on wavelength, frequency, and their interaction. Specifically, retinal DOPAC/DA ratios were positively correlated with refractions in white and green light conditions. However, blue light (0, 0.5, and 20.0 Hz) produced hyperopic shifts but decreased vitreous DOPAC levels and retinal DOPAC/DA ratios.ConclusionsThe retinal DOPAC/DA ratio, indicating the metabolic efficiency of DA, is correlated with ocular growth. It may underlie myopic shifts from light exposure with a long wavelength and low temporal frequency. However, different biochemical pathways may contribute to the hyperopic shifts from short wavelength light.

Effect of light quality and quantity on productivity and phycoerythrin concentration in the cryptophyte Rhodomonas sp.

The cryptophyte Rhodomonas sp. is a potential feed source for aquaculture live feed and resource for phycoerythrin (PE) production. This research investigates the influence of light, both quality and quantity, on the biomass productivity, composition and growth rate of Rhodomonas sp. The incident light intensity used in the experiments was 50 μmolphotons m−2 s−1, irrespective of the colour of the light, and cultivation took place in lab-scale flat-panel photobioreactors in turbidostat mode. The highest productivity in volumetric biomass (0.20 gdry weight L−1 day−1), measured under continuous illumination, was observed under green light conditions. Blue and red light illumination resulted in lower productivities, 0.11 gdry weight L−1 day−1 and 0.02 g L−1 day−1 respectively. The differences in production are ascribed to increased absorption of green and blue wavelength by phycoerythrin, chlorophyll and carotenoids, causing higher photosynthetically usable radiation (PUR) from equal photosynthetically absorbed irradiance (PAR). Moreover, phycoerythrin concentration (281.16 mg gDW−1) was stimulated under red light illumination. Because photosystem II (PSII) absorbs poorly red light, the algae had to induce more pigments in order to negate the lower absorption per unit pigment of the incident available photons. The results of this study indicate that green light can be used in the initial growth of Rhodomonas sp. to produce more biomass and, at a later stage, red light could be implemented to stimulate the synthesis of PE. Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated a significant difference between the cells under different light quality, with higher contents of proteins for samples of Rhodomonas sp. cultivated under green light conditions. In comparison, higher carbohydrate contents were observed for cells that were grown under red and blue light.

0171 The Impact of Short-Term Bright Green Light Exposure in Partially Sleep-Deprived Persons

Abstract Introduction Many workers and students experience regular sleep deprivation and daytime sleepiness when they are expected to be performing at their best. The purpose of the current research was to investigate the potential effect of short-term bright green light exposure on daytime performance and sleepiness in partially sleep-deprived persons. Methods Participants were 30 students (19.4±0.89 years; 20 females). On Day 1, participants were loaned a Fitbit to provide an objective measure of activity/sleep and were instructed to sleep no more than 5 hours that night. On Day 2, participants provided information on their sleep time for the previous night and were randomly assigned to a bright light condition (bright green light, 381 Lux) or a standard light condition (control condition, indoor florescent light, 139 Lux). They completed a simple reaction time task, the Arrow Flankers task to measure cognitive inhibition, and the Stanford Sleepiness Scale during three testing periods (baseline, after 20 minutes of light exposure, and after 60 minutes of light exposure). Between the testing periods, participants read a non-fiction book while exposed to their respective light condition. At the end of the study, participants returned their FitBit. Results The Fitbit and self-report sleep data indicated that participants slept 4.9 hours the night between Day 1 and Day 2. Mixed 2 (light condition) x 3 (testing period) ANOVAs indicated that the bright green light condition resulted in a significant decrease in reaction time on the Flankers task but had no significant effect on simple reaction time or subjective sleepiness. Conclusion The current findings suggest that 60 minutes of bright green light exposure could improve performance on a cognitive inhibition task. This suggests that bright green light exposure could be a useful countermeasure for cognitive performance decrements in settings where sleep deprivation is common. Support None to report.

Light-regulated synthesis of extra- and intracellular enzymes related to wood degradation by the white rot fungus Cerrena unicolor during solid-state fermentation on ash sawdust-based medium.

The light-dependent metabolism of the white rot basidiomycete Cerrena unicolor FCL139 has already been demonstrated using transcriptomic and Biolog-based approaches. To further analyze the influence of light on C. unicolor wood degradation, we measured the activity of an array of CAZymes (carbohydrate-active enzymes) and enzymes involved in the redox system of fungal cells associated with lignolysis. Extra- and intracellular enzymatic extracts were obtained from solid-state ash sawdust C. unicolor cultures cultivated for 14 days under red, blue, green, or white light conditions, or in the dark. Light greatly influenced the synthesis of MnP, total cellulases, endo-1,4-β-glucanase, endo-1,4-β-xylanase, catalase, and superoxide dismutase. The production of MnP and catalase was evidently stimulated by white light. It is also worth noticing that blue light caused a gradual increase in the activity of total cellulases throughout the entire period of C. unicolor growth. Moreover, endo-1,4-β-glucanase showed the highest activity on day 13 of fungus cultivation and the production of laccase and β-glucosidase appeared to be the least influenced by light. However, the strongest activity of the endo-1,4-β-xylanase was observed in the dark. It seemed that light not only influenced the regulation of the synthesis of the wood-degrading enzymes at different levels, but also acted indirectly by affecting production of enzymes managing harmful lignin by-products causing oxidative stress. The ability of the fungus to decompose woody plant material is clearly influenced by environmental factors.

Effect of Body Coloration on Male-Male Competition in a Cyprinid Fish Puntius titteya.

In some species, male traits are more exaggerated than female traits. To understand the evolution and maintenance of such male traits, it is important to clarify their function in contexts of both intra- and intersexual selection. However, information about the function of specific male traits in both male-male competition and female mate choice remains limited. Male Puntius titteya assume a bright red, carotenoid-based coloration over the whole body. A previous study revealed that females in this species prefer to mate with redder males. In the present study, we examined the function of male coloration in male-male competition under both white and green light conditions. Under white light, in which males could perceive red coloration, males with higher color saturation compared to their opponents became dominant. On the other hand, under green light, in which males could not accurately perceive red coloration, the effect of male coloration on male-male competition disappeared, and only male body size significantly influenced intermale competition, i.e., larger males were dominant. These results indicate that, under environments in which red coloration can be assessed by males, body coloration affects male-male competition. These findings suggest that carotenoid-based coloration in P. titteya males plays a key role in both intra- and intersexual selection.