Effects Of Different Light Conditions Research Articles

Effects of different light conditions on anatomical and histological features of galls in bacterial gall disease of Cerasus × yedoensis.

Cerasus × yedoensis (cherry 'Shomei-yoshino' Fujino) is affected by bacterial gall disease caused by Pseudomonas syringae pv. cerasicola (PSC). C. × yedoensis is often infected with PSC under weak light intensity which indicates that susceptibility of C. × yedoensis to PSC is affected by light. To evaluate the effects of white light intensity and different light qualities, white or blue, on bacterial gall disease development, we quantitatively assessed the anatomical and histological features of bacterial-inoculated sites on branches of two-year-old potted C. × yedoensis seedlings grown under different light intensities and qualities. The stronger the white light intensity, the less severe the gall symptoms. Gall formation was suppressed more by blue than white light of the same intensity. The validity of a simple gall index for assessing gall development with the naked eye, via quantitative evaluation of gall shape by measuring gall height, width and volume, showed that the gall index could be used as a practical method for on-site assessments of gall development. The ratio of degenerated area in the gall remained constant, suggesting the presence of some regulatory mechanism preventing PSC from affecting the entire gall exists within the plant. Microscopy showed that gall tissue is comprised primarily of callus cells and has voids containing gummy material that is exuded from cracks in the gall, and that the periderm develops at the gall foot but not at the gall apex, so that the cells at the gall apex were necrotic or collapsed.

Effects of different light conditions on transient expression and biomass in Nicotiana benthamiana leaves.

In the process of the production of recombinant proteins by using an Agrobacterium-mediated transient gene expression system, the effectiveness of the control of light conditions pre- and post-agroinfiltration on efficiency of transient expression is worth being evaluated. In this study, Nicotiana benthamiana plants were used as a bioreactor to investigate the effects of different light conditions pre- and post-agroinfiltration on the transient expression of green fluorescent protein (GFP). The results showed that the plants grown under light condition for 5 weeks had the highest level of transient expression among those grown for 4-8 weeks. In the pre-agroinfiltration, the level of transient expression of GFP was obviously decreased by the increase in light intensity or by the shortening of the photoperiod. Although the shortening of the photoperiod post-agroinfiltration also decreased the level of transient expression, moderate light intensity post-agroinfiltration was needed for higher level of transient expression efficiency. However, there was no strong correlation between the transient expression efficiency and plant growth. The results suggested that light condition was an important factor affecting the level of transient expression in plants. Hence, light conditions should be optimized to obtain higher productivity of recombinant protein from transient expression systems.

Stability of factors influencing walking-along-the-road pedestrian injury severity outcomes under different lighting conditions: A random parameters logit approach with heterogeneity in means and out-of-sample predictions

Pedestrians walking along the road’s edge are more exposed and vulnerable than those on designated crosswalks. Often, they remain oblivious to the imminent perils of potential collisions with vehicles, making crashes involving these pedestrians relatively unique compared to others. While previous research has recognized that the surrounding lighting conditions influence traffic crashes, the effect of different lighting conditions on walking-along-the-road pedestrian injury severity outcomes remains unexplored. This study examines the variations in the impact of risk factors on walking-along-the-road pedestrian-involved crash injury severity across various lighting conditions. Preliminary stability tests on the walking-along-the-road pedestrian-involved crash data obtained from Ghana revealed that the effect of most risk factors on injury severity outcomes is likely to differ under each lighting condition, warranting the estimation of separate models for each lighting condition. Thus, the data were grouped based on the lighting conditions, and different models were estimated employing the random parameter logit model with heterogeneity in the means approach to capture different levels of unobserved heterogeneity in the crash data. From the results, heavy vehicles, shoulder presence, and aged drivers were found to cause fatal pedestrian walking-along-the-road severity outcomes during daylight conditions, indicators for male pedestrians and speeding were identified to have stronger associations with fatalities on roads with no light at night, and crashes occurring on Tuesdays and Wednesdays were likely to be severe on lit roads at night. From the marginal effect estimates, although some explanatory variables showed consistent effects across various lighting conditions in pedestrian walking-along-the-road crashes, such as pedestrians aged < 25 years and between 25 and 44 years exhibited significant variations in their impact across different lighting conditions, supporting the finding that the effect of risk factors are unstable. Further, the out-of-sample simulations underscored the shifts in factor effects between different lighting conditions, highlighting that enhancing visibility could play a pivotal role in significantly reducing fatalities associated with pedestrians walking along the road. Targeted engineering, education, and enforcement countermeasures are proposed from the interesting insights drawn to improve pedestrian safety locally and internationally.

Advances in the use of white light on broccoli and kale postharvest shelf life

In this work, the effect of irradiation with three different intensities of white light-emitting diodes (LED) on the quality and senescence of refrigerated broccoli and green and red kale was studied. A high increase in weight loss was observed in samples exposed to high (80 μmol m−2 s−1) and low (10 μmol m−2 s−1) LED intensity. Samples stored under mid-intensity (30 μmol m−2 s−1) significantly reduced the change of total color (∆E), hue angle, and lightness (L*) values. Broccoli florets and green kale subjected to mid-intensity illumination retained higher chlorophyll levels than the other treatments (P < 0.05), and about 30% more compared to the dark stored samples. These differences were even more evident in red kale. Mid-intensity illumination also markedly reduced sugar losses and improved carotenoid contents. As a whole, results show that the selected intensity of white light used for postharvest illumination has a key influence on treatment efficacy. Industrial relevancePostharvest shelf life of green vegetables is very limited and there is a need to use environmentally friendly tools to extend it. The use of white light during storage has been proven to be a clean and non-chemical methodology to delay vegetable senescence, but the appropriate illumination conditions to maximize the quality of unprocessed vegetables are still unknown. In the present work, the effect of different lighting conditions on the visual and nutraceutical quality of refrigerated broccoli and green and purple kale was studied, and the best condition was defined. The selected light intensity may be considered for fresh market storage.

Light conditions during Atlantic salmon embryogenesis affect key neuropeptides in the melanocortin system during transition from endogenous to exogenous feeding.

During the first feeding period, fish will adapt to exogenous feeding as their endogenous source of nutrients is depleted. This requires the development of a functional physiological system to control active search for food, appetite, and food intake. The Atlantic salmon (Salmo salar) melanocortin system, a key player in appetite control, includes neuronal circuits expressing neuropeptide y (npya), agouti-related peptide (agrp1), cocaine- and amphetamine-regulated transcript (cart), and proopiomelanocortin (pomca). Little is known about the ontogeny and function of the melanocortin system during early developmental stages. Atlantic salmon [0-730 day degrees (dd)] were reared under three different light conditions (DD, continuous darkness; LD, 14:10 Light: Dark; LL, continuous light) before the light was switched to LD and the fish fed twice a day. We examined the effects of different light conditions (DD LD , LD LD , and LL LD ) on salmon growth, yolk utilization, and periprandial responses of the neuropeptides npya1, npya2, agrp1, cart2a, cart2b, cart4, pomca1, and pomca2. Fish were collected 1 week (alevins, 830 dd, still containing yolk sac) and 3 weeks (fry, 991 dd, yolk sac fully consumed) into the first feeding period and sampled before (-1 h) and after (0.5, 1.5, 3, and 6 h) the first meal of the day. Atlantic salmon reared under DD LD , LD LD , and LL LD had similar standard lengths and myotome heights at the onset of first feeding. However, salmon kept under a constant light condition during endogenous feeding (DD LD and LL LD ) had less yolk at first feeding. At 830 dd none of the neuropeptides analyzed displayed a periprandial response. But 2 weeks later, and with no yolk remaining, significant periprandial changes were observed for npya1, pomca1, and pomca2, but only in the LD LD fish. This suggests that these key neuropeptides serve an important role in controlling feeding once Atlantic salmon need to rely entirely on active search and ingestion of exogenous food. Moreover, light conditions during early development did not affect the size of salmon at first feeding but did affect the mRNA levels of npya1, pomca1, and pomca2 in the brain indicating that mimicking natural light conditions (LD LD ) better stimulates appetite control.

Luminous restriction and chemical control with glyphosate in integrated management of Urochloa brizantha L.

The objective was to evaluate the effect of different light conditions in the cultivation environment on the control of U. brizantha by glyphosate. The experimental design was in a plot scheme divided into randomized blocks with five replications. In the plots, environments with light conditions were allocated: full sun, intermittent shading with 3 hours of sun/day, and continuous shading. In the subplots, the herbicide doses: 0, 480, 960, and 1440 g. a. e. glyphosate ha-1 applied to U. brizantha plants. The control of U. brizantha by the herbicide glyphosate was more efficient in shaded environments, either with continuous or intermittent shading, in relation to full sun, indicating that the conditions of light influenced the action of the herbicide. At 35 DAA, control values of U. brizantha above 80% were observed from the 765 g. a. e ha-1 dose of glyphosate for treatments with shading. Already in conditions of full sun, 65% of control values were reached in the highest dose, which is considered unsatisfactory for the management of this species. U. brizantha submitted to light restriction had the content of epicuticular wax, starch, soluble and total sugar reduced; however, the leaf area was larger in these environments compared to full sun. The reserve content, epicuticular wax, and leaf area variables are affected by shading with a direct relationship with the greater control of U. brizantha by glyphosate in this cultivation condition.

Artificial light affects the foraging behavior in greater white‐toothed shrews (CROCIDURA RUSSULA)

AbstractLight pollution is one of the forms by which human‐induced alterations are changing natural environments. Artificial light at night (ALAN) has been increasing over the past decades and it is already known that ALAN can have a major influence on the ecology, behavior, and physiology of different taxa. Nocturnal small mammals are particularly vulnerable, as ALAN can increase their predation risk while foraging. The aim of this study was to investigate foraging strategies under different light conditions in a nocturnal small insectivore, the greater white‐toothed shrew (Crocidura russula). Compared with rodents, shrews have a higher metabolic rate and thus present a good model for a foraging study. In three laboratory experiments with wild‐caught shrews we tested (i) food preference under dark conditions as well as the effect of different light conditions on (ii) foraging strategies and (iii) food choice. The results showed that shrews had a clear food preference under dark conditions. They also preferred to forage under dark over light conditions when presented with the same food in both conditions. However, when presented with the choice of foraging their preferred food under illuminated conditions or a lower food quality in the dark, the food preference of shrews overruled their preference for feeding in the dark. It seems that food preference, rather than risk perception, is the main driver determining the foraging strategy of the greater white‐toothed shrews. This study suggests that ALAN does not necessarily prevent high‐metabolic nocturnal insectivores from achieving their energetic needs, which might help explain their persistence in urban environments.

Investigating Search Among Physical and Virtual Objects Under Different Lighting Conditions.

By situating computer-generated content in the physical world, mobile augmented reality (AR) can support many tasks that involve effective search and inspection of physical environments. Currently, there is limited information regarding the viability of using AR in realistic wide-area outdoor environments and how AR experiences affect human behavior in these environments. Here, we conducted a wide-area outdoor AR user study ($n=48$) using a commercially available AR headset (Microsoft Hololens 2) to compare (1) user interactions with physical and virtual objects in the environment (2) the effects of different lighting conditions on user behavior and AR experience and (3) the impact of varying cognitive load on AR task performance. Participants engaged in a treasure hunt task where they searched for and classified virtual target items (green "gems") in an augmented outdoor courtyard scene populated with physical and virtual objects. Cognitive load was manipulated so that in half the search trials users were required to monitor an audio stream and respond to specific target sounds. Walking paths, head orientation and eye gaze information were measured, and users were queried about their memory of encountered objects and provided feedback on the experience. Key findings included (1) Participants self-reported significantly lower comfort in the ambient natural light condition, with virtual objects more visible and participants more likely to walk into physical objects at night; (2) recall for physical objects was worse than for virtual objects, (3) participants discovered more gems hidden behind virtual objects than physical objects, implying higher attention on virtual objects and (4) dual-tasking modified search behavior. These results suggest there are important technical, perceptual and cognitive factors that must be considered if the full potential of "anywhere and anytime mobile AR" is to be realized.

Effects of LED Light Quality on the Growth of Pepper (Capsicum spp.) Seedlings and the Development after Transplanting

In this study, the effects of different light conditions on the growth of pepper seedlings and the development of these pepper seedlings after transplanting were explored. Based on the control light, pepper seedlings were grown under radiation with different proportions of added blue, UV-A, and far-red light for 18 days. Compared with the control, supplementation with UV-A and far-red light increased the seedling height whereas blue light decreased. Blue and UV-A treatments increased seedling compactness and the seedling index while far-red light treatments have obvious inhibitory effects. The chlorophyll content of the UV-A treated seedlings was significantly increased, but far-red light reduced the carotenoid content. Far-red light increased the activities of SOD and CAT and decreased the MDA content of seedlings. After transplanting, there was no obvious difference in the flowering time of all treated pepper plants. An increase in pepper yield was discovered when pepper seedlings were supplemented with blue and UV-A light. Overall, our results demonstrated that proper supplementation of UV-A and blue light at the seedling stage positively produces strong and healthy pepper seedlings, and could increase the yield of pepper plants after transplanting.

Effects of different light conditions on growth, muscle nutrients content, and clock gene circadian expression of Takifugu rubripes

Basic knowledge about the effect of light on fish in needed to improve their development, survival, and growth to increase aquaculture efficiency. In this study, the effects of light photoperiods (light (L): dark (D) = 12:12 and 16:8) and spectrum (full spectrum (W), blue (B) and yellow (Y)) on Takifugu rubripes larvaes were assessed from 20 to 80 days after hatching (dah). At 50 dah, the body length of larvae exposed to Y16:8 and B16:8 was significantly higher than that in the W16:8 group (P < 0.05). The wet weight of larvae reared under B16:8 was significantly higher than that under B12:12 (P < 0.05). The wet weight of larvae exposed to B12:12 was significantly higher than that in the W12:12, and the wet weight of larvae exposed to B16:8 was significantly higher than that of larvae exposed to W16:8 and Y16:8 (P < 0.05). At 80 dah, the body length and wet weight of larvae reared under 12:12 were significantly higher than those of larvae reared under 16:8 in the white and yellow LEDs groups (P < 0.05). Additionally, the biochemical composition of muscle were affected, the levels of DHA and EPA+DHA were significantly higher in the W16:8 and B16:8 groups, compared to the W12:12 and B12:12 groups, respectively (P < 0.05). Since light is the predominant signal for the entrainment of circadian oscillators and controls growth as a zeitgeber, the expression of arylalkylamine N-acetyltransferase 2 (annat2), crytochrome 2 (cry2), peroid1 (per1) and per3 in the brain were also been measured. The long photoperiod 16:8 delayed the acrophases of annat2, and blue light decreased the expression of cry2 and per3. These results provide the theoretical basis for using LED lights in aquaculture production of T. rubripes larvae.

Simulating the effect of different lighting conditions on left-turn driving behavior using a scenario-based anger method

Anger is a key factor affecting drivers' subjective judgment and driving skills. The influence of anger on driving behavior has been widely studied, but there is a lack of comparative research under different lighting conditions. Through a driving simulation experiment, this paper studies the influence of anger on left-turn driving behavior under two light conditions day and night. In the experiment, 32 licensed participants were divided into two groups, one in emotional neutrality and the other in anger. Among them, the emotional state of anger is induced by a traffic-related video. The results showed that compared with daytime participants, participants at night had higher anger intensity, shorter gap acceptance, and post encroachment time (PET) when left-turn driving. In addition, compared with neutral emotion participants, angry participants tended to accept shorter gap acceptance and PET when turning left. This indicates that participants failed to respond correctly to left-turn driving behavior in a state of anger. However, the response of gender differences to situational driving anger was not affected by light conditions. The anger intensity of male participants during the day and night was higher than that of female participants, and the gap between acceptance and PETs during left-turn was shorter than that of female participants. This shows that male participants are more likely to produce high-intensity anger and are more likely to make dangerous driving decisions in a state of anger. This paper puts forward some suggestions on identifying anger and preventing angry driving.

Effects of Different Lighting Conditions on Growth, Yield and Nutrient Content of White Oyster Mushroom in Vertical Farm

The world population is continuously growing at a rapid rate, so a great challenge for this time is to ensure the security of food and nutrition for this increased population seeking for new crop as a source of food and nutrition. In such state mushrooms, a great source of protein, can be a favor that can be cultivated by landless people using agricultural waste material. The research work was about to analyze the effect of three lighting conditions namely dark condition (C1), medium lighting condition (C2), and sunlight (C3) on growth, yield, and nutrient content of pleurotus ostreatus (white oyster mushroom). Vertical farming technology was applied in mushroom production in order to minimize the land use. Three vertical structures each of three layers were used. This study also encompassed the effects of different layers (bottom later L1, middle layer L2, top layer L3) on the growth and yield of mushroom. The findings of this investigation revealed that there were significant differences in growth and yield at different conditions and structural layers. The highest average growth and yield (stalk height 3.87 cm, cap size 11.89 cm, stipe size 2.65 cm, crops per bag 15.78, fresh weight 60.03 g, and dry weight 17.03 g) was observed in dark condition (C1). On the other hand, lowest growth, and yield (stalk height 1.59 cm, cap size 3.67 cm, stipe size 1.51 cm, crops per bag 4.22, fresh weight 18.38 g, and dry weight 4.47 g) was found in sunlight (C3). Oyster mushroom cultivated in dark condition C1 also have high nutrient content. The study suggested that maintaining the absolute darkness is capable of producing high-quality white oyster mushroom.

P–188 Ambient light intensity and wavelength in the IVF laboratory does not affect life birth rates

Abstract Study question Do different wavelengths and intensities in ambient lighting affect clinical outcomes? Summary answer Variations on ambient lighting intensity and wavelength do not affect life birth rates. What is known already Light is one of the factors to consider when designing an IVF laboratory. Most IVF clinics work under reduced illumination, trying to mimic uterine conditions as much as possible. Nevertheless, it has been described that 95% of the light that affects an embryo comes from the microscope, not ambient lighting. It is well accepted that exposure to extreme lighting conditions affects embryos through photo-oxidation and the creation of reactive oxygen species. Still, there is no study that documents the effect of different wavelengths on human embryos. Study design, size, duration Prospective study performed between january 2019 and february 2020. Every 60 days we changed ambient illumination conditions using the LED lighting installed throughout the IVF laboratory. Six different groups were created: Cyan (470nm), Green (550nm), Yellow (600nm), Orange (625nm), intense white (WH), and low intensity white (WL) as control group. Participants/materials, setting, methods A total of 572 egg donation cicles with 355 fresh single embryo transfers were included in the study. In all cycles ICSI and Time-lapse culture was performed (Embryoscope, Vitrolife). PGT and testicular biopsy/aspiration treatments were excluded. Eggs and embryos were exposed to ambient illumination during pick-up, denudation, ICSI, and embryo transfer procedures. Main results and the role of chance Light exposure during embryo/gamete manipulation is inevitable. Hence, we analyzed parameters linked to the success of an IVF cycle to assess the effect of different lighting conditions concluding that neither light color nor intensity affect IVF success rates. No differences were found between groups regarding maternal age, age of the recipient, diagnostic, or number of eggs received (p &amp;gt; 0.05). Fertilization rates were similar between groups (C = 77.04%; G = 73.72%; Y = 75.64%; O = 78.1%; WL = 76.4%; WH = 75.2%; p = 0.216) as well as good quality blastocyst rates (C = 57.35%; G = 57.37%; Y = 62.30%; O = 59.75%; WL = 63.28%; WH = 60.55%; p = 0.234). Regarding clinical outcomes both implantation and miscarriage rates were found to be equal between groups (C = 61.67%; G = 52.89%; Y = 55.10%; O = 66.18%; WL = 66.00%; WH = 53.55%; p = 0.194, and C = 24.32%; G = 19.15%; Y = 11.11%; O = 24.44%; WL = 15.15%; WH = 8.11%; p = 0.301). The main outcome for this study was live birth rates and no differences were found (C = 51.85%; G = 50.00%; Y = 52.17%; O = 53.97%; WL = 57.14%; WH = 50.75%; p = 0.168). Limitations, reasons for caution We must take into account that embryos were cultured inside a time-lapse incubator, diminishing the effect of ambient light. Wider implications of the findings: This study demonstrates that, with advances in culture technology, neither light intensity nor light wavelength affecting gametes/embryos during manipulation influence clinical outcomes. Trial registration number Not applicable

Ecophysiology and production of red pitaya under different light conditions

In commercial orchards of red pitaya fruit, yellowish cladodes frequently occur, mainly in the warmest months of the year. The measurement of probable interferences on the ecophysiology and production of red pitaya and their correlations are unprecedented and may present a basis for commercial producers. This study aimed to analyze the effect of different light conditions on growth, anatomy, photosynthetic pigments, gas exchanges, and the production of red pitaya in Fortaleza (CE). The experimental design was carried out in randomized blocks (RDB), with five treatments, five replications, and two plants per plot. The treatments consisted of five levels of luminosity: full sunlight, 35, 50, 65, and 80% shading, with the use of PVC shade screens. At 365 days, morphological, biochemical, physiological, and anatomical characters were analyzed. The fruit production was estimated from the first fruit emission, which occurred 186 days after the experiment installation. It is concluded that the luminosity conditions interfere with a variably in the growth, anatomical structures, photosynthetic pigments, gas exchanges, and production, as well as on their correlations. The crop presented high phenotypic plasticity and adequately acclimated to cultivation in full sunlight, obtaining the highest production. Moreover, this study recommended cultivating in full sunlight and at 35% shading, which showed the greatest performances in terms of ecophysiological variables and productive yield.

Effect of light condition on the growth performance and biochemical compositions of post-mating female mud crab (Scylla paramamosain)

Understanding factors affecting the reproductive performance of mud crab (Scylla paramamosain) is important for the optimization of the culture conditions. There are some indications that complete darkness could enhance and accelerate the spawning in female decapods, but sometimes it may lead to low larval quality. Therefore, the present study was carried out to clarify the effect of different light conditions on female S. paramamosain during the post-mating period. To accomplish this, proximate compositions, total carotenoid content, amino acid and fatty acid profiles were investigated in female S. paramamosain cultured under two different light conditions: complete darkness (0 ± 0 lx; 0 h light: 24 h dark) and normal light condition (7.00 ± 1.50 lx; 12 h light: 12 h dark; this light condition is regular in S. paramamosain hatcheries). Further, weight gain ratio (WGR), specific growth rate (SGR), gonado-somatic index (GSI), and hepatosomatic index (HSI) were also investigated. Different light conditions affected carotenoid, protein, amino acid, and fatty acid contents, but not growth parameters. Female S. paramamosain cultured under complete darkness had lower amino acids and protein contents in the muscle in comparison with those under the normal light condition. Moreover, complete darkness decreased the ovarian protein and carotenoid. The changes in fatty acids profiles were variable under the two light conditions. These results indicated that the lowering of carotenoid and protein contents in the ovary under complete darkness could be the potential limiting factors affecting the reproductive performance of post-mating female S. paramamosain.

Relative Effects of Varying Light Conditions on the Growth of Toxic and Non-Toxic Strains of &amp;lt;i&amp;gt;Microcystis aeruginosa&amp;lt;/i&amp;gt;

Harmful algae bloom constitutes a major problem facing water bodies particularly fresh and marine water system. Microcystis aeruginosa represents a major causative organism found in the water. Light plays a major role in the growth and variation of M. aeruginosa in water. What is still inadequate, is the data on the effects of different light conditions on the growth of Microcystis aeruginosa. In this study, two strains of Microcystis aeruginosa PCC 7806 (toxic strain) and PCC 7005 (non-toxic strain) were exposed to varying light intensities at 0, 30, 60, 120, 300, 350 μMol photon m-2·S-1 to measure their growth and pigmentation. This study observed similarities in growth and pigmentation between toxic strain (PCC 7806) and non-toxic (PCC 7005) strain. Also, at short exposure to light, Toxic strain was seen to be better tolerant of light than non-toxic strain, with non-toxic strain showing better ability to recover from light stress after twenty days of culture. These findings suggest that Toxic strain (PCC 7806) and Non-toxic strain (PCC 7005) of M. aeruginosa respond similarly with respect to growth but differ in their light retention capacity over time and this could be useful in predicting the possible conditions of algal bloom.

Effects of Light on Saccharide Wastewater Treatment and Resource Recovery by Proteiniphilum acetatigenes PSB-W

Photosynthetic bacteria (PSB) wastewater treatment is a new method with great resource recovery potential. In order to improve the biomass and valuable resources of bacteria in the wastewater treatment of photosynthetic bacteria, the effects of different light conditions on the efficiency of Proteiniphilum acetatigenes PSB-W in the treatment of sugar wastewater and the production of bacteria and carotenoids in the wastewater were analyzed from three aspects of light source, light intensity and light period. Under the principle of priority of pollutant removal efficiency, the red LED light was selected with the light intensity of 4000 Lux, 16L (light):8D (dark) for light cycle, and the best efficiency of wastewater removal and bacterial yield were obtained when the culture time was 3d, Chemical oxygen demand (COD) removal rate was 80.9%, bacterial OD600 was 0.907 ± 0.023, carotenoid yield was 7.83 ± 0.27 mg/L, respectively. These results show that PSB-W strains can provide more biomass and valuable substances in suitable environment. It provides a theoretical basis for the realization of wastewater recycling.

Effects of different light conditions on ammonium removal in a consortium of microalgae and partial nitrifying granules

Ammonium removal by a coupling process of microalgae (Chlorella sorokiniana) with partial nitrifying granules was evaluated in batch reactors illuminated in a wide range of light intensities (0, 100, 450, and 1600 μmol photons m−2 s−1). Ammonium oxidation performance for different light exposure time showed that the granules had a light stress tolerance at 1600 μmol photons m−2 s−1 for up to 12 h, but continuous illumination induced severe inhibition on nitrifying bacteria thereafter. Ammonium removal efficiencies at the end of tests were 66%, 62%, 5%, and −10% (due to ammonification) for 0, 100, 450, and 1600 μmol photons m−2 s−1, respectively. The nitrogen mass balance shows co-occurrence of microalgal growth taking up 24% of fed ammonium and nitrifying bacteria oxidizing 38% of fed ammonium at 100 μmol photons m−2 s−1, while both nitrification and microalgal growth are inhibited at light intensity above 450 μmol photons m−2 s−1. In comparing results from this study with previous results, it was found that the ammonium removal pathway, i.e., nitrification or microalgal uptake, is regulated more strongly by daily average light intensity than by instantaneous light intensity. Empirical model equations to estimate the oxygen balance in consortium reactors categorized the effect of daily average light intensities on process performance as follows: (i) below 27 μmol photons m−2 s−1: insufficient oxygen for nitrification; (ii) 27 to 35: sufficient oxygen for nitrification via nitrite; (iii) 35 to 180: sufficient oxygen for nitrification via nitrate; (iv) above approximately 200–300: oversaturated dissolved oxygen, excess free ammonia and/or intensive light inhibitions.

Effects of different light conditions on the retinal microstructure and ultrastructure of Dicentrarchus labrax larvae.

Light is a key environmental parameter known to influence fish throughout various stages of their life, from embryonic development to sexually mature adults. In a recent study, the effects of different light conditions on the growth of Dicentrarchus labrax larvae were investigated using light-emitting diodes (LEDs) as a light source. Here, pathological examinations were carried out to assess whether variations in light affected the visual system of the larvae, including any negative impacts on the retina or the growth rate. Although light did not affect the total thickness (TT) of the retina, the thickness of the retinal pigment epithelium layer (PRE), photoreceptor layer (PRos/is), outer nuclear layer (ONL), and inner nuclear layer (INL), and the PRE/TT and ONL/TT ratios were all significantly higher in larvae exposed to blue light than in larvae exposed to white light. Additionally, the thickness of PRE and the outer nuclear layer and the RPE/TT and ONL/TT ratios of larvae exposed to 2.0 W m-2 were significantly lower than in larvae exposed to 0.3 W m-2. By contrast, the INL/TT ratio in larvae exposed to 2.0 W m-2 was significantly higher than in larvae exposed to 0.3 W m-2. Additionally, the INL and ganglion cell layer nuclei density of larvae exposed to 2.0 W m-2 were significantly higher than in those exposed to 0.3 W m-2 (p < 0.05). Transmission electron microscopy revealed different levels of abnormalities in the photoreceptor layers in all treatment groups. Considering the growth of the larvae, the results of the study suggest that continuous LED exposure induced damage to photoreceptor cells but was not relevant to the growth performance of D. labrax larvae. Moreover, the results obtained here also support the high plasticity of retinal development in response to altered environmental light conditions.

Effects of different light conditions to the structure and biomass of Emmenopterys henryi seedlings

Emmenopterys henryi is a unique genus of Rubiaceae in China. It belongs to the national precious tree species announced by the Ministry of Forestry. Shading net was used to set 20%, 40%, 60%, 80% shading and natural light (full light) respectively to measure the structure and biomass changes of E. henryi seedlings under different shading conditions. The results showed that the length, dry weight, wet weight and diameter of trunk decreased linearly with the increase of shading degree, and the difference was significant under different light conditions (p < 0.05). With the increase of shading degree, the length, dry weight and wet weight of the first branch of the main trunk of E. henryi seedlings increased first and then decreased. The diameter of the first branch of the main trunk of E. henryi seedlings decreased linearly, and the difference was significant under different light conditions (p < 0.05). With the increase of shading degree, the length and diameter of the main roots of E. henryi showed a linear downward trend, while the dry weight and wet weight showed a wavy trend of first decreasing, then rising and then decreasing, with significant differences under different light environments (p < 0.05). In general, with the decrease of light intensity, the biomass increment of E. henryi seedlings decreased significantly. The result implies that light affects the morphological composition and biomass synthesis of E. henryi seedlings.