Effects Of Different Light Sources Research Articles

Accuracy improvement of a multi-ring beam structured inner surface measurement: via novel calibration methodology and light source optimization

Parts with a large depth-to-diameter ratio play a critical role in the military, aerospace, and automotive industries. However, accurately measuring their inner surface profile remains challenging owing to the lack of adequate and accurate sensors. We developed a multi-ring structured light system to obtain three-dimensional data of inner contours, such as inner diameters, which are crucial for ensuring component performance and safety. In this study, we proposed three simple yet effective techniques to improve the multi-ring beam structured measurement system. First, we designed a distortion correction method to calibrate the imaging system. Second, a two-step calibration approach was used to calibrate the multi-ring projection. Meanwhile, we benchmarked the effects of different light sources on image speckles. The calibration results demonstrated that the coefficient of determination (R-2) used for line fitting exceeded 0.999. Moreover, the measurement experimental results show that the uncertainty of less than 10 µm and the smallest measurable pipe inner diameter can reach 15 mm, demonstrating that our methods are promising for improving the accuracy of structured light optical sensing systems. This system satisfies the measurement requirements and can be immediately utilized to meet the high demand for inner contour measurements in industrial applications.

Photostabilities and anti-tumor effects of curcumin and curcumin-loaded polydopamine nanoparticles.

Currently, the photostability of photosensitizer curcumin is the main bottleneck limiting their application, reducing the bioavailability of curcumin. Studying the effect of different light sources on the photostabilities of curcumin and loading it onto polydopamine nanocarriers with better biocompatibility will help improve its light utilization efficiency. In this study, we investigated the photostabilities of curcumin and a polydopamine-based nanoparticle (polydopamine-curcumin composite nanoparticles, PDA-Cur NPs) loaded with curcumin through in vitro and in vivo experiments to achieve better antitumor effects. The results demonstrated that curcumin has good photostability in dark, but with significant photodegradation rates in both red and blue light. Blue light has a faster effect on the photodegradation of curcumin, with a degradation rate of 42.1% after 10 minutes, which is about 1.7 times that of the red light. Our study successfully synthesized PDA-Cur NPs, demonstrating its ability to stably load and release curcumin, with a loading percentage of 65.7% after 2 hours and 41.9% release in 8 hours (pH 6.0). Compared with single curcumin treatments, the photodegradation rates of PDA-Cur NPs in red and blue light treatments were reduced by 46% and 50%, respectively. Meanwhile, PDA-Cur NPs exhibited remarkable antitumor efficacy due to PDT and promote apoptosis in cancer cells, which both better than that of single curcumin treatments. Moreover, in MCF-7 tumor-bearing mice, the PDA-Cur NPs led to significant tumor growth inhibition effects, without causing evident systemic damage in vivo. The findings highlight the potential of PDA-Cur NPs as anticancer photosensitizer with greatly increased utilization of curcumin in PDT.

In situ measurement of light transmission into wine bottles and calculation of shelf life

Wine exposed to UV-A and violet light (320–440 nm) can develop a light-struck flavour which deteriorates its quality. In a short introduction, we briefly describe the two most important photochemical pathways of this process and discuss conditions that facilitate the formation of undesired compounds. The main thrust of the study is to use a novel method to determine light transmission into real wine bottles, along with optical and photochemical modelling of wine damage. Calculation of light transmission into bottles and resulting photochemical damage is described in detail and compared to in situ measurements of transmitted light inside bottles. The effect of different light sources (sunlight, fluorescent bulbs and LED bulbs) is also discussed. It is found in in situ measurements that clear (flint) bottles transmit up to 35 % and bluish-green bottles up to 8 % of the harmful UV–violet light, while light amber bottles only up to 1.2 % and dark amber ones up to 0.2 %. Results of simple tasting experiments support the validity of shelf life calculations described here. According to these findings, white wine in flint (clear) and bluish-green bottles can survive only for a few days while displayed on shelves; light amber bottles conserve the quality for about a month and dark amber bottles for more than a year. Recommendations concerning the protection of shelf-displayed bottled wine from light exposure are also given.

WS2 Gas Sensor Based on Photothermocatalytic Effect for Ammonia Detection With High Response

In this article, four different light sources are utilized to enhance the WS2-based gas sensors properties, and the improvement effects of different light sources on the sensitive characteristics of the sensors are systematically analyzed. First, the WS2 nanomaterials are synthesized by hydrothermal method. In addition, the nanostructures and morphologies are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Finally, the effect of different temperatures and different ammonia concentrations on the sensor response is examined, including darkness, various light illumination (365, 532, 650, and 980 nm). Under dark conditions, the sensor response time is 46 s and recovery time is 55 s in 100-ppm ammonia gas, while the sensor has excellent selectivity for ammonia with a response of up to 81.84 times and only weak response for other gases. The results reveal that the four types of light are capable of reducing the operating temperature where the response value reach the peak. Meanwhile, the maximum response value is effectively increased, from a maximum value of 27 in the dark to a maximum value of 57 under light illumination. The 650-nm light illumination and the 980-nm light illumination exhibit the best effect on improving the response value. Therefore the 180 °C measured by the sensor response curve under 650-nm light conditions is defined as the optimal temperature. At the same time, light illumination can degrade the detection limit of the sensor. Under dark conditions, the ammonia detection limit of the sensor is 100 ppm, while under light illumination conditions, the ammonia detection limit of the sensor is 20 ppm.

Bright as day and dark as night: light-dependant energy for lipid biosynthesis and production in microalgae.

Microalgae are photosynthetic organisms functioning as the green bio-factories for various pharmaceutical and biofuel products. To date, numerous attempts have been carried out to manipulate culture conditions to maximize the production of the desired metabolites. Because light is the energy source of microalgae for their growth and metabolites biosynthesis, it has been one of the most investigated variables emphasized on the deep understanding of how microalgae respond towards light changes as an external stimulus. This review discusses the effects of different light sources, light intensities, light wavelengths and length of photoperiod on various microalgae species, especially in terms of biomass and lipid productivity. Additionally, the relationship between photoregulation processes and lipid productivity of microalgae are also deliberated. The current available approaches of microalgae mass cultivation, including different types of open and closed systems are recapitulated with the intention to highlight the significant insights for the design of future photoreactors.

Influences of yellow and green lights on the visual response of western flower thrips and field verification

This study aimed to determine the effects of spectral light characteristics on the visual response of the western flower thrips, the strengthening mechanism of thrips response behavior regulated by light, and thrips response characteristics to contrast light. Light with combined and single wavelength were tested by using a self-made behavior response device for thrips. Light sources for trapping thrips were made to verify the trapping effect on thrips in a greenhouse, and the reasons for changes in thrips behavior were analyzed to characterize the mechanism of their phototactic response. The results showed that the light mode (single, contrast, combined light) affected the thrips visual response and approach response, whereas in contrast light, the effects were optimal. Combination light inhibited the thrips visual response, and when the illumination increased, the thrips visual response to single and combination light intensified, and the thrips approach sensitivity to green light increased in contrast and combination light. However, the light mode did not affect the thrips visual response and sensitivity to spectral light characteristics. The degree of thrips visual response to yellow light was stronger than that to green light, while the degree of thrips visual response to green light was stronger than that to yellow light, indicating that the photo-induced mechanism of the thrips visual response differed from that of the thrips approach response. Moreover, in the greenhouse, the trapping effect of different light sources on thrips was positively correlated with temperature. The trapping effect of green light was optimal, followed by a yellow light source, while the difference of light intensity (illumination, illumination energy) and its photo-thermal intensity between yellow and green light was the reason for the differences in the degree of visual trends and the trapping effects of thrips. However, the sensitivity of thrips responding to different light depended on the difference in the heterogeneous stimulation intensity of different spectral light. Thus, light brightness and photo-thermal effects were the causes of thrips visual responses, while bio-photoelectric reaction effects caused thrips to produce a visual response and affected the degree of the thrips visual response. The results reveal the underlying causes of pest control by light, and provide a theoretical basis for the research and development of pest induction equipment and light arrangements. Keywords: pest control, western flower thrips, yellow and green light, visual response, field verification, light mode DOI: 10.25165/j.ijabe.20221504.6432 Citation: Liu Q H, Zhao M Q, Miao J, Fu G C, Wu Y Q. Influences of yellow and green lights on the visual response of western flower thrips and field verification. Int J Agric & Biol Eng, 2022; 15(4): 49–56.

Comparative Effects of Different Light Sources on the Production of Key Secondary Metabolites in Plants In Vitro Cultures.

Plant secondary metabolites are known to have a variety of biological activities beneficial to human health. They are becoming more popular as a result of their unique features and account for a major portion of the pharmacological industry. However, obtaining secondary metabolites directly from wild plants has substantial drawbacks, such as taking a long time, posing a risk of species extinction owing to over-exploitation, and producing a limited quantity. Thus, there is a paradigm shift towards the employment of plant tissue culture techniques for the production of key secondary metabolites in vitro. Elicitation appears to be a viable method for increasing phytochemical content and improving the quality of medicinal plants and fruits and vegetables. In vitro culture elicitation activates the plant’s defense response and increases the synthesis of secondary metabolites in larger proportions, which are helpful for therapeutic purposes. In this respect, light has emerged as a unique and efficient elicitor for enhancing the in vitro production of pharmacologically important secondary metabolites. Various types of light (UV, fluorescent, and LEDs) have been found as elicitors of secondary metabolites, which are described in this review.

Influence of yellow and green light on the visual response of western flower thrips and its field verification

This study aimed to determine the effects of spectral light characteristics on the visual response of the western flower thrips, the strengthening mechanism of thrips response behavior regulated by light, and thrips response characteristics to contrast light. Combination light and single light were tested by use of a self-made behavior response device for thrips. Light sources for trapping thrips were made to verify the trapping effect on thrips in a greenhouse, and the reasons for changes in thrips behavior were analyzed to characterize the mechanism of their phototactic response. The results showed that the light mode affected the thrips visual response and approach response, whereas in contrast light, the effects were optimal. Combination light inhibited the thrips visual response, and when the illumination increased, the thrips visual response to single and combination light intensified, and the thrips approach sensitivity to green light increased in contrast and combination light. However, the light mode did not affect the thrips visual response and sensitivity to spectral light characteristics. The degree of thrips visual response to yellow light was stronger than that to green light, while the degree of thrips visual response to green light was stronger than that to yellow light, indicating that the photo-induced mechanism of the thrips visual response differed from that of the thrips approach response. Moreover, in the greenhouse, the trapping effect of different light sources on thrips was positively correlated with temperature. The trapping effect of green light was optimal, followed by a yellow light source, while the difference of light intensity (illumination, illumination energy) and its photo-thermal intensity between yellow and green light was the reason for the differences in the degree of visual trends and the trapping effects of thrips. However, the sensitivity of thrips responding to different light depended on the difference in the heterogeneous stimulation intensity of different spectral light. Thus, light brightness and photo-thermal effects were the causes of thrips visual responses, while bio-photoelectric reaction effects caused thrips to produce a visual response and affected the degree of the thrips visual response. The results reveal the underlying causes of pest control by light, and provide a theoretical basis for the research and development of pest induction equipment and light arrangements.

Effects of Different LED Light Recipes and NPK Fertilizers on Basil Cultivation for Automated and Integrated Horticulture Methods

This study aims to optimize the conditions for “Genovese” basil (Ocimum Basilicum) germination and growth in an indoor environment suitable for horticulture through a synergic effect of light and fertilizers addition. In fact, several studies determined that specific light conditions are capable of enhancing basil growth, but this effect is highly dependent on the environmental conditions. In this study, the effect of different light sources was determined employing a soil with a negligible amount of fertilizer, demonstrating substantial improvement when light-emitting diode (LED) lights (hyper red and deep blue in different combinations) were applied with respect to daylight (Plants height: +30%, Total fresh mass: +50%). Thereafter, a design of experiment approach has been implemented to calculate the specific combination of LED lights and fertilizer useful to optimize the basil growth. A controlled-release fertilizer based on nitrogen, phosphorus, and potassium (NPK) derived from agro-residues was compared with a soil enriched in macronutrients. The results demonstrate significant improvements for the growth parameters with the employment of the controlled-release NPK with respect to enriched soil combined with a ratio of hyper red and deep blue LED light equal to 1:3 (Total fresh mass: +100%, Leaves number: +20%).

Biomass growth of red spinach in plant-factory system under three kinds of LED light sources

The research is trying to observe the effect of different light sources on red spinach (Amaranthus Tricolor L) plant. Plant-factories were installed and divided into three compartments. Each compartment was given three light sources: Red-Blue LED (R-B), Multi-Color LED (M-C), and White LED (W). The energy of each light sources R-B, M-C, and W were 192 Watt, 92 Watt, and 8 Watt, respectively. The research took place on March 2018 in the Agriculture Technology Laboratory, Jenderal Soedirman University, Indonesia. The growth parameters measured were plant height, biomass, and number of leaves. Results showed that there was significant difference of growth parameters of treatment R-B compared to treatment M-C, and W. Shierary Model were used to study the mechanism of growth parameter difference. The model used the input of radiation energy of light sources that were affected by leaves development, that called the intercepted radiation. The result of the model showed that the intercepted radiation influenced the growth parameters. Treatment R-B, which generates commonly used light wave for photosynthetic, caused better plant growth. The influence of the heat emerged from the light sources were seemed to create better micro-climate for photosynthesis.

Light sources on the germination and initial in vitro establishment of Schomburgkia crispa Lindl., a species of the Brazilian Cerrado

ABSTRACT: Light is one of the factors that influence the germination and initial establishment of orchids under in vitro cultivation. This study evaluated the effect of different light sources on these stages in in vitro cultivation of Schomburgkia crispa Lindl. After sowing in an aseptic environment, we stored the cultures in a screened greenhouse (natural light) or in a growth room with the following light sources: 3,000 K yellow LED; 6,500 K white LED [1]; 6,500 K white LED [2]; or 6,500 K white fluorescent lamp (control). We assessed germination percentage and initial seedling establishment at 45 and 90 days after sowing. Light did not influence the germination of S. crispa. However, the use of 3,000 K LED provided a faster initial establishment of S. crispa when compared to the other light sources, also presenting lower seedling mortality. Thus, the light source 3,000 K LED is a potential substitute for the 6,500 K fluorescent lamps and LEDs used in growth rooms in in vitro culture laboratories.

Effects of different light sources used for dental operating microscope illumination on the visual function of operators

ObjectivesAdvances in dental operative microscopes (DOMs) enable examination of root canal morphology or detection of root fractures otherwise not visible to the naked eye. However, dental therapy involving prolonged use of DOMs requires precision within a limited visual field, resulting in eye strain among users. This study examined the effects of halogen and light-emitting diode (LED) light sources on asthenopia and visual function following use of DOMs. MethodsThe study used halogen and LED light sources in DOMs. The first experiment was conducted on 6 participants with corrected visual acuity without any organic eye disease. General visual function test (calculation ability test, hand grip strength test, and ophthalmic examination) and subjective symptom questionnaire were used to evaluate the degree of fatigue before and after DOM use. The second experiment was conducted on 9 participants with spherical equivalents within ±4 diopters (D) and astigmatism of 1 D or less. Accommodative function tests (precise test for asthenopia) and a subjective symptom questionnaire (asthenopia) were used before and after use of DOM. ResultsNo significant changes were noted in the degree of fatigue and ophthalmological parameters before and after the procedure with either light source or in between light sources. The tear firm breakup time was shortened after therapy, and a tendency toward dry eyes was observed while using the LED light source. ConclusionsThe halogen and LED light sources used for DOM therapy had similar effects on asthenopia of the operators, with no significant changes in visual function.

Effect of Light Sources on Bond Strength of Different Composite Resins Repaired with Bulk-Fill Composite

The aim of this study was to evaluate and compare the effects of different light sources on shear bond strength when bulk-fill composite was used for the repair of different composite resins. A total of 126 samples made from six resin composites with different properties were aged (thermal-cycling with 5000 cycle), exposed to the same surface treatments and adhesive procedure. Then, they were repaired with a bulk-fill composite. At the polymerization step, each group was divided into three subgroups (n=7) and light cured with a QTH light source for 40s and two different LED light sources for 20s. Subsequently, the specimens were aged in distilled water at 37 ºC for 4 weeks and then subjected to shear bond strength test. Then, the specimens were examined under a stereomicroscope to identify modes of failure and visualized by Scanning Electron Microscope. Data obtained from the study were analyzed using ANOVA and Tukey HSD Test (α=0.05). In all groups, the light curing units had an impact on shear bond strength (p<0.05). Among the study groups, the greatest bond strength values were observed in the specimens repaired using the LED and the specimens repaired with the QTH light curing unit had the lowest bond strength values. It was concluded that the content of composite resins and light curing units may influence bond strength of different composites repaired with the bulk-fill composite.

Effects of different light sources on tooth shade selection.

Differences in lighting conditions can make matching the shade of a single porcelain tooth to the natural adjacent teeth very challenging. The purpose of the study was to examine visual shade selection under 3 different light sources - natural daylight, a dental operating light and a color-corrected light. The visual assessment was based on a comparison between a shade guide and the target tooth. One observer with normal color vision was asked to visually match the color of the maxillary central right incisor and the maxillary right canine in a group of 100 subjects, aged 22-40 years. Two shade guides were used - VITA Vitapan Classical® and VITA 3D Master® - in natural daylight as well as under an operating light and a handheld light (Demetron Shade Light®). The VITA Easyshade® spectrophotometer was used to evaluate the results of the visual shade selection method. Significant differences were found between the effects of using the shade guide systems (p < 0.05) and light sources (p < 0.05). Overall, the use of the Vitapan Classical shade guide significantly improved the correlation between visual matching and the spectrophotometer readings. Within the limitations of this study, the Vitapan Classical shade guide demonstrated superior agreement in shade selection as compared to the 3D Master shade guide. The Demetron Shade Light was proven to be a useful device for the color matching of artificial teeth in prosthodontic treatment. Visual tooth color matching is a subjective method and it produces the best results under a color-matching light.

58 Effect of different light sources on the developmental capacity of bovine embryos produced invitro

Under natural conditions, mammalian oocytes and zygotes are never exposed to daylight or artificial light. During assisted reproductive procedures such as invitro production (IVP), oocytes and pre-implantation embryos are exposed to light from time to time before being transferred to recipients. The detrimental effect of visible light is not directly related to the intensity and exposure time, but is also a function of the spectral composition of the light. Recently, a green pass light filter was used during all steps of bovine IVP. Results indicated the protective effect of the filter against harmful blue and infrared regions of the light (Korhonen et al. 2009 Hum Reprod. 24, 308-314; https://doi.org/10.1093/humrep/den432). Data regarding either blue or infrared light are missing. Therefore, the effect of environmental light will be examined on the developmental capacity of bovine oocytes and pre-implantation embryos produced invitro. Three different experimental conditions were set during all IVP steps: (i) light from the microscope filtered with a red pass filter, no artificial light, and no daylight, (ii) artificial light without day light, light from the microscope without a filter, and (iii) artificial and daylight, light from the microscope without a filter, as normally used in the laboratory (control). Bovine cumulus-oocyte complexes were recovered from abattoir-derived ovaries by the slicing method. After 24h of maturation, fertilisation was realised and after 19h of co-culture of cumulus-oocyte complexes and sperm, presumptive zygotes were cultured in SOFaa for 8 days. Cleavage and developmental rates were recorded at Day 3 and Day 7/8 (Day 0=IVF, 10 IVP runs). Blastocysts from all groups were individually stored at −80°C until analyses. Then RT-qPCR (at least 12 replicates) was performed as described previously (Stinshoff et al. 2014 Reprod. Fertil. Dev. 26, 502-510; https://doi.org/10.1071/RD12372) for gene transcripts related to cellular stress (BAX, BCL2L1, HSPA1A, SOD1) and embryo developmental capacity (SLC2A3). The morphological quality of expanded blastocyst was assessed via a differential staining procedure (with propidium iodide and Hoechst, 4 replicates) to determine the number of inner cell masses (ICM), trophectoderms (TE), and total cells and to calculate the ICM/TE ratio. Data were analysed by analysis of variance followed by a Tukey test. Cleavage and developmental rates were similar in all groups of embryos (P&amp;gt;0.05). The relative abundance of all analysed gene transcripts was significantly increased (P ≤ 0.05) in blastocysts stemming from settings (i) and (ii) compared with those from the control group. Blastocysts generated using only artificial light or artificial and daylight did show a significantly increased number of ICM and total cells (86.3±3.2, 56.3±1.4; 183.6±4.0, 161.8±2.8) compared with embryos produced under filtered microscope light without any other light (35.3±0.8; 133.8±1.4; P ≤ 0.05). The number of TE cells was similar (P&amp;gt;0.05) in blastocysts of all groups (i: 98.5±1.3; ii: 97.3±2.6; iii (control): 105.5±2.4). These data suggest that day light exposure might influence bovine embryos at the molecular level, whereas the morphological quality seems to be unaffected when compared with embryos exposed to only artificial light.

Effects of Different Light Sources on Neural Activity of the Paraventricular Nucleus in the Hypothalamus.

Background and Objectives: Physical function is influenced by light irradiation, and interest in the influence of light irradiation on health is high. Light signals are transmitted from the retina to the suprachiasmatic nucleus (SCN) via the retinal hypothalamic tract as non-image vision. Additionally, the SCN projects a nerve to the paraventricular nucleus (PVN) which acts as a stress center. This study examined the influences of three different light sources on neural activity in the PVN region using two different color temperatures. Materials and Methods: Experiments were conducted using twenty-eight Institute of Cancer Research (ICR) mice (10 week old males). Three light sources were used: (1) organic light-emitting diode (OLED) lighting, (2) LED lighting, and (3) fluorescent lighting. We examined the effects of light irradiation from the three light sources using two different color temperatures (2800 K and 4000 K). Perfusion was done 60 min after light irradiation, and then the brain was removed from the mouse for an immunohistochemistry analysis. c-Fos was immunohistochemically visualized as a marker of neural activity in the PVN region. Results: The number of c-Fos-positive cells was found to be significantly lower under OLED lighting and LED lighting conditions than under fluorescent lighting at a color temperature of 2800 K, and significantly lower under OLED lighting than LED lighting conditions at a color temperature of 4000 K. Conclusions: This study reveals that different light sources and color temperatures alter the neural activity of the PVN region. These results suggest that differences in the light source or color temperature may affect the stress response.

Effect of the red light on the photosynthesis and phenolic accumulation in leaves of Hedyotis corymbosa (L.) Lam

Hedyotis corymbosa (L.) Lam a native herbaceous species containing many phenolic compounds is used in traditional medicine and medicinal technology. Phenolic acid, as well as many other secondary metabolites are photosynthetic-derived products. In this research, red LEDs (660 nm) and white fluorescent light were used to investigate the effects of different light sources on the photosynthesis and leaf phenolic compound accumulation of in vitro and ex vitro plants. Red LED (50 umol/m2/sec) promoted the stem elongation without changing plant biomass of in vitro plants. Increasing red LED intensities (from 50 to 100 or 150 umol/m2/sec) decrease maximum photochemical quantum yield of PS II (Fv/Fm) and coefficient of photochemical fluorescence quenching (qP), but stabilized electron transfer (ETR) and coefficient of non-photochemical fluorescence quenching (qN) of in vitro leaves. Under 100 umol/m2/sec of red LED, ex vitro leaf area, carotenoid contents, isolated chloroplast. Hill reaction and total sugar content were significantly reduced in comparison to those parameters from control plants under white light. Ex vitro plants' total carbohydrate contents were not statistically different the total leaf phenolic content of ex vitro plants under red LED light exposure was much higher than that the of control.&#x0D;

Effect of blue light on growth and exopolysaccharides production in phototrophic Rhodobacter sp. BT18 isolated from brackish water.

Rhodobacter sp. BT18, a phototrophic salt-resistant bacterium, was isolated from brackish water and screened for the production of exopolysaccharides (EPS). The effect of different light sources on the growth of Rhodobacter sp. BT18 was investigated. The effect on the growth order was found to be blue > white > green > red > yellow > dark. Based on Box-Behnken design, the studied variables (pH 7.0, 35 °C, and 30% of sucrose concentration under 60 h of incubation with blue light illumination) were found to be ideal for the maximum production of EPS (582.5 mg/L). Scanning electron microscopy images revealed the porous nature of EPS. Fourier transform spectroscopy and X-ray diffraction were applied to study the functional groups and the crystalline nature of the EPS, respectively. The emulsification index of the EPS was >75% and the maximum flocculating activity was about 75.4% at 30 mg/L concentration of EPS. In addition, EPS showed effective arsenic (64%) and lead (51%) chelating activities in liquid solutions. The multiple environmental applications of the EPS produced by Rhodobacter sp. BT18 make it be a promising alternative for emulsification, flocculation and metal removal in various industries.

Proteomic profile and polyamine contents are modulated by light source to promote in vitro shoot development in Cariniana legalis (Martius) O. Kuntze (Lecythidaceae)

The effect of different light sources on in vitro shoot development in Cariniana legalis, an endangered species from the Atlantic Forest, was evaluated. Cotyledonary and apical nodal explants were subjected to light-emitting diode (LED) lamps with different spectral combinations and fluorescent lamps (control). Shoot growth, endogenous contents of free polyamines (PAs) and proteomic profiles were analyzed at 60 days of development. Treatments consisting of white, low-blue and deep-red, with (W/lB/dR/fR) and without (W/lB/dR) far-red spectra, resulted in greater elongation of shoots from cotyledonary nodal explants, and the low-blue and deep-red spectral combination appeared to be a positive factor stimulating shade-avoidance responses. Shoots grown under the W/lB/dR LED exhibited greater elongation and higher contents of free putrescine, spermidine and total free PAs compared to those grown under the fluorescent lamp. Comparative proteomic analysis revealed 15 up- and 41 down-regulated proteins in shoots grown under the W/lB/dR LED lamp when compared to the control. The differentially up-regulated proteins in shoots grown under the LED lamp are related to cell organization and composition, as well as biological regulation processes, whereas proteins related to stress processes were down-regulated. The LED lamp consisting of white, low-blue and deep-red spectra increased shoot elongation in C. legalis, in association with differential accumulation of proteins and PAs, suggesting the relevance of source light on in vitro shoot development in this species. A light source combining low-blue and deep-red spectra enhanced shoot elongation, differential protein accumulation and polyamine contents during in vitro shoot development in C. legalis.

Evaluation of the Impact of Light Source on Reproductive Parameters in Laying Hens Housed in Individual Cages.

Higher light wavelengths have been shown to stimulate extra-retinal photoreceptors more efficiently than lower wavelengths to promote reproduction in poultry. We developed a light emitting diode (LED) bulb that emits 60% of its light in the red spectrum (LED-R), and evaluated the effects of different light sources on growth and reproduction in commercial layer hens. Three rooms equipped with either 100W incandescent, 15W compact fluorescent (CFL), or 10W LED-R bulbs were populated with 96 Lohmann LSL-Lite layers housed in individual cages from 14 to 69 weeks of age (woa). Pullets were initially maintained on a 10-h photoperiod, then photostimulated at 18 woa. Surprisingly, regardless of the light source, plasma levels of estradiol peaked at 16 woa, 2 weeks before photostimulation, and egg-laying was initiated at 19 woa. As a direct correlation between age at first egg and body weight was identified, metabolic cues most likely served as a primary trigger to initiate sexual maturation prior to photostimulation. Overall egg production and cumulative egg numbers were similar among treatments. Interestingly, a second increase in estradiol was observed at 52 woa under all treatments, suggesting an additional ovarian stimulation, possibly associated with an additional follicular recruitment at that age. Overall, changes in estradiol concentrations were more pronounced in hens maintained under LED-R light than in hens exposed to incandescent and CFL, especially for the second increase, suggesting that a higher amount of red light leads to stronger ovarian activity. Maintaining hens under LED-R bulbs also resulted in lower feed consumption, which combined with the lower energy consumption of LED-bulbs (LED-R: 306 kW; incandescent: 2,514 kW; CFL: 422 kW) could reduce the production cost.