异色瓢虫不同光环境下的交配行为

ABSTRACTAspergillus oryzae is a safe filamentous fungus widely used in the food, medicine, and feed industries, but there is currently not enough research on the light response of A. oryzae. In this study, 12 different light conditions were set and A. oryzae GDMCC 3.31 was continuously irradiated for 72 h to investigate the effect of light on mycelial growth and conidium production. Specifically, each light condition was the combination of one light wavelength (475, 520, or 630 nm) and one light intensity (20, 40, 60, or 80 μmol photon m−2 s−1). The results show that mycelium growth was inhibited significantly by green light (wavelength of 520 nm and intensities of 20 and 60 μmol photon m−2 s−1) and blue light (wavelength of 475 nm and intensity of 80 μmol photon m−2 s−1). The production of conidia was suppressed only by blue light (wavelength of 475 nm and intensities of 40, 60, and 80 μmol photon m−2 s−1), and those levels of inhibition increased when the intensity of blue light increased. When the strain was irradiated by blue light (80 μmol photon m−2 s−1), the number of conidia was 57.4% less than that of the darkness group. However, within our set range of light intensities, A. oryzae GDMCC 3.31 was insensitive to red light (wavelength of 630 nm) in terms of mycelium growth and conidium production. Moreover, interaction effects between light wavelength and intensity were found to exist in terms of colony diameter and the number of conidia. This research investigated the light response of A. oryzae, which may provide a new method to regulate mixed strains in fermented foods by light.IMPORTANCE Studies on the monochromatic light response of Aspergillus nidulans and Neurospora crassa have gone deep into the molecular mechanism. However, research methods for the light response of A. oryzae remain in the use of white light sources. In this study, we first demonstrated that A. oryzae GDMCC 3.31 was sensitive to light wavelength and intensity. We have observed that blue light inhibited its growth and sporulation and the inhibitory effect increased with intensity. This research not only adds new content to the study of the photoreaction of Aspergillus but also brings new possibilities for the use of light to regulate mixed strains and ultimately improve the flavor quality of fermented foods.

ABSTRACTThe use of electronic devices with light-emitting screens has increased exponentially in the last decade. As a result, humans are almost continuously exposed to unintentional artificial light. We explored the independent and combined effects of two aspects of screen illumination, light wavelength, and intensity, on sleep, its biological regulation, and related functional outcomes. The 2 × 2 repeated-measure design included two independent variables: screen light intensity (low ([LI] versus high [HI]) and wavelength (short [SWL] versus long [LWL]). Nineteen participants (11F, 8M; mean age 24.3 [±2.8] years) underwent four light conditions, LI/SWL, HI/SWL, LI/LWL, and HI/LWL, in counterbalanced order. Each light exposure lasted for two hours (21:00–23:00), following which participants underwent an overnight polysomnography. On each experimental night, oral temperature and urine samples (for melatonin analysis) were collected at multiple time points. Each morning, participants filled out questionnaires and conducted a computerized attention task. Irrespective of light intensity, SWL illumination significantly disrupted sleep continuity and architecture and led to greater self-reported daytime sleepiness. SWL light also altered biological rhythms, subduing the normal nocturnal decline in body temperature and dampening nocturnal melatonin secretion. Light intensity seemed to independently affect sleep as well, but to a lesser degree. Both light intensity and wavelength negatively affected morning attention. In sum, light wavelength seems to have a greater influence than light intensity on sleep and a wide-range of biological and behavioral functions. Given the widespread use of electronic devices today, our findings suggest that screen light exposure at evening may have detrimental effects on human health and performance.

Phototactic behavior of live food rotifer Brachionus plicatilis species complex and its significance in larviculture: A review

MoS2 based photosensor detecting both light wavelength and intensity

BackgroundArtificial agriculture is promoted as an economically viable technology for developing plants under controlled conditions whereby light, water, and fertilizer intake are regulated in a controlled manner to produce maximum productivity with minimal resources. Artificial light has been used to produce high-quality vegetables because it can regulate plant growth and phytochemical production through light intensity, photoperiod, and spectrum modulation. This study aimed to compare the physiological and biochemical responses of Chinese cabbage (Brassica rapa var. chinensis) grown under artificial light with varying light intensities (75 and 150 µmol m−2 s−1), photoperiods (12:12 and 6:6:6:6 h), and wavelengths (blue, red, and magenta) to plants grown in a glasshouse under natural light. The novelty of this study lies in the manipulation of artificial LED lighting to achieve high-quality plant growth and phytochemical composition in B. rapa model vegetables for potential optimal productivity.ResultsThe analysis revealed that B. rapa grown under artificial lights produced more consistent biomass yield and had a higher chlorophyll content than B. rapa grown under natural light (control). Plants grown under artificial lights have also been shown to produce biochemical compositions derived primarily from fatty acids, whereas plants grown under natural light have a biochemical composition derived primarily from alkanes. Twenty compounds were found to be statistically different between light treatments out of a total of 31 compounds detected, indicating that they were synthesized in response to specific light conditions. Exposure to the full artificial light spectrum (white) resulted in the absence of compounds such as dodecane and 2,6,10-trimethyltridecane, which were present in B. rapa grown in natural light, whereas exposure to the blue spectrum specifically induced the production of tetracosane. Eicosane, neophytadiene, l-(+)-ascorbic acid 2,6-dihexadecanoate, and (Z,Z,Z)-9,12,15-octadecatrienoic acid were all prevalent compounds produced in B. rapa regardless of light conditions, and their absence may thus affect plant development and survival.ConclusionsThe results show that cultivation under artificial light produced consistent biomass, high chlorophyll content, and phytochemical content comparable to natural light conditions (control). These findings shed light on how artificial light could improve the production efficiency and organoleptic qualities of Chinese cabbage.Graphical

Phasic response of the photoperiodic clock to wavelength and intensity of light in the redheaded bunting, Emberiza bruniceps

We present a method for quantifying the growth advantage, if any, that results from the plasticity of plant traits in response to growth in high vs. low resource levels. The method, which uses two phenotypes and two resource levels, quantifies the average advantage that a phenotype has, in its own set of conditions, over the other phenotype. The method is applied to the growth of two phenotypes of Abutilon theophrasti, induced by high and low light intensity, in response to two levels of incident light intensity. We calculated the growth advantage first using relative growth rate, and second using whole-plant photosynthetic assimilation rate, as the response variable. Then we used the photosynthetic responses to changes in light intensity to calculate changes in growth rates of each phenotype when exposed to a change in light conditions. These three quantifications of growth advantage broadly agree with one another. Despite the great plasticity of its traits induced by growth in high vs. low light intensity, whole-plant plasticity did not allow Abutilon theophrasti to exhibit a significant growth advantage under these conditions. Indeed, the relative growth rate of the low light phenotype greatly exceeded that of the high light phenotype in high incident light conditions. This may have resulted from the higher leaf area ratio of the low light phenotype. Furthermore, the high light phenotype had significantly greater transpiration rate in both light conditions. For these reasons we suggest that light-induced plasticity of traits in Abutilon theophrasti may confer advantage in response to the variation in vapor pressure deficit that is associated with variation in light intensity. Light-induced plasticity may also be advantageous because under high incident light conditions the high-light phenotype has greater reproductive allocation than the low-light phenotype.

BackgroundOur aim was to determine the association between melanopsin gene polymorphism and pupillary light reflex under diverse photic conditions, including different intensities and wavelengths.MethodsA total of 195 visually corrected subjects volunteered for investigation of the melanopsin gene of single nucleotide polymorphism (SNP) of rs1079610 (I394T). The genotype groups were TT (n = 126), TC (n = 55), and CC (n = 8), and 75 of the subjects, including subjects with TT (n = 34), TC (n = 33), and CC (n = 8) participated in our experiment. Three monochromatic lights with peak wavelengths of 465 nm (blue), 536 nm (green), and 632 nm (red) were prepared, and each light was projected to the subjects with five intensities, 12, 13, 14, 14.5 and 15 log photons/(cm2 s), for one minute. The pupil size of the left eye was measured under each light condition after a 1-minute adaptation.ResultsThe pupils of the TC + CC genotypes (n = 38) were significantly smaller than those of the TT genotype (n = 31) under a blue (463 nm) light condition with 15 log photons/(cm2 s) (P < 0.05). In contrast, there were no significant differences under green (536 nm) and red (632 nm) light conditions. Conversely, relative pupil constrictions of the TC + CC genotypes were greater than those of the TT genotype under both blue and green conditions with high intensities (14.5 and 15 log photons/(cm2 s)). In contrast, there were no significant differences between genotype groups in pupil size and relative pupilloconstriction under the red light conditions.ConclusionsOur findings suggest that the melanopsin gene polymorphism (I394T) functionally interacts with pupillary light reflex, depending on light intensity and, particularly, wavelength, and that under a light condition fulfilling both high intensity and short wavelength, the pupillary light response of subjects with the C allele (TC + CC) is more sensitive to light than that of subjects with the TT genotype.

Degradation analyses of GaInP/GaAs/Ge solar cells irradiated by 70 keV and 150 keV protons by current-voltage curves under various intensities of light

Differences in dynamic behavior of single diatom cells caused by changing wavelengths

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Lighting is essential for broiler growth, maturation, and reproduction. Globally, broilers are reared under various production systems including outdoor enclosures that do not allow for extensive control over their environment. However, in the United States large homogenous houses with extensive control over environmental factors including light source, intensity, photoperiod, and wavelength are used for achieving productivity goals. Improving these management practices is essential to improving production efficiency in commercial operations since the sole means of lighting for broilers is artificial. Traditionally incandescent lighting has been used as the standard throughout the industry. However, these bulbs are inefficient and costly due to their short lifespan. Compact fluorescent lighting has also been used, but can be disruptive to broilers. Therefore, new LED has become available to be utilized in this commercial setting. Using this technology would cut cost for the producer and could also have some advantageous effects for the broiler. Previous research has shown increased growth and performance of broilers under different wavelengths of LED light but it is unclear which light source would be the most advantageous. Two floor pen trials were conducted to determine the effects of using a standard white LED technology to the traditional incandescent and fluorescent, as well as, wavelengths of blue, green, and red light. Lights were kept at a standard 16 hour light and 8 hour dark cycle. Treatments for the first trial consisted of an incandescent, fluorescent, white LED, blue LED, and green LED, and combination of green and blue LED light. Each were set at 10 lux intensity and reduced to 5 lux at 28 days. No statistical differences were observed between treatments for production parameters during the evaluated 17, 35, and 49 day periods. Therefore, it was concluded white LED could be used and produce the same results compared to traditional lighting options. A similar second trial was conducted to determine the effects of using a standard white LED in comparison to LED bulbs of blue, green, and red wavelengths. Treatments consisted of a white LED, blue LED, green LED, and red LED. Each were set at 10 lux intensity and reduced to 5 lux at 28 days. Lights were kept at a standard cycle of 16 hours light and 8 hours dark. While differences were overserved for carcass composition data at 50 days of age for minor breast and wing yield between the varying wavelengths of light, none of these wavelengths had a greater effect on performance when compared to the white LED. Therefore it is concluded that white LED lighting should be the standard across the broiler industry. Its utilization will allow producers to reduce their cost of production without cutting into their profits from production.

This study investigated the effects of the light conditions on the productivity of scenedesmus dimorphus in the continuous mass cultivation system. To compare the algal productivity according to the light conditions, S. dimorphus was cultivated continuously under the wide range of light intensity(200-600 PPFD) and various light wavelength(white light and red-blue mixed light). After 100 days of cultivation under the different light intensity, the productivity of S. dimorphus increased as light intensity decreased. So, the productivity was maximized as 100 mg/L/d when light intensity was 200 PPFD. In case of light wavelength, the productivity of S. dimorphus was enhanced about 20% with the white light compared to that of the red-blue mixed light. Consequently, the optimal light conditions for the continuous mass cultivation of S. dimorphus were 200 PPFD as light intensity and white light as light wavelength.

SummaryIn the first paper of this series it was shown that Lolium perenne material required hardening periods involving low, but above freezing, temperatures before frost tolerance was achieved. The present experiments show that the light conditions during the hardening and prehardening periods are also important. At both stages a reduction in total light energy reduced subsequent cold tolerance but the relative effects of light intensity and photoperiod differed between the prehardening and hardening treatments. Thus low light input during the hardening period at 2 CC reduced cold tolerance most when given at higher intensities over shorter days (8 h) while during the prehardening growing period at 20 °C the reduction was greatest when the lower light input was given at low intensity over longer days (16 h).Varieties of different climatic origins reacted differentially to the treatments. The Mediterranean variety Fano was particularly adversely affected by low light intensities during hardening and also benefited from higher temperatures during the prehardening growing period. With higher light intensities and higher growth temperatures this Mediterranean variety approached the more northern material in cold tolerance; but as a corollary it was clear that the N. European variety Veja was able to harden under lower light conditions, and lower growing temperatures. The varieties Melle and S. 321 from intermediate latitudes, were intermediate in response.Although water soluble carbohydrate content was increased during the hardening period, except at the lowest light intensity (2·9 W/m2), no simple relationship between the WSC content and the cold tolerance of the different varieties could be detected.The results provide a useful guide to the pre-treatments necessary to discriminate between varieties for cold tolerance in such a way that the results can be correlated with field performance.

Light modulation of volatile organic compounds from petunia flowers and select fruits

Changes in isoenzyme profiles of antioxidative enzymes, superoxide dismutase, peroxidase and catalase, in leaves of Impatiens flanaganiae Hemsl. subjected to different light conditions were investigated. Unbranched plantlets of I. flanaganiae propagated from tubers were exposed to three light regimes: 55 μmol m− 2 sec− 1, 280 μmol m− 2 sec− 1 and 30 μmol m− 2 sec− 1 (variants I, II and III respectively) for a period of seven weeks. Isoenzymes of superoxide dismutase, peroxidase and catalase and their differential responses to light variations were studied in plant extracts prepared from leaves of all three variants at weekly intervals. The activity of most SOD isoenzymes from plants subjected to low light intensity (variants I and II) remained relatively constant except for one Cu/Zn-SOD that increased gradually during the course of development. Little or no change in catalase activity was observed during the initial stage development of plants from these variants. A profound enhancement of catalase level was detected only from the fifth week onward, especially in variant III. The induction of some SODs and CAT in plants from these variants could be related to possible oxidative stress associated with plant aging. In contrast to CAT, the activity of some of the peroxidase isoenzymes in variant III decreased from the second week onward and was lower than in the plants from the other two variants during the initial stages of development. Plants from variants I and III also showed a steady increase in activity of most isoperoxidases (low and high mobility) with time, which suggests their indirect involvement in the regulation of plant growth and development. A rapid increase in the activity of superoxide dismutase and catalase during the experimental period was observed in plants exposed to relatively high light intensity (variant II). The activities of both Mn, and some of the Cu/Zn- containing SODs increased sharply from the second week onward under high light intensity as compared to the other two variants subjected to low light intensity. The Mn-SOD activity remained high throughout the experimental period, while the light-induced Cu/Zn- SODs showed a reduction in activity after the third week. This light-induced response could be an attempt to protect plants from the harmful radicals generated due to photo-oxidative stress under high light. The low activity of some isoperoxidase observed under these conditions is considered to be compensated by high catalase activity as the active oxygen species, hydrogen peroxide, is removed by catalase and/or peroxidase. These metal containing enzymes seem to respond differentially to variations in light and could be suitable as a marker for the evaluation of light-induced oxidative stress in Impatiens flanaganiae plants.