Fluorescent Light Exposure Research Articles

Light-induced fading effects on TL and OSL signals and feasibility of dose re-assessment with PTTL signals in BeO dosimeters

Abstract This study aims to investigate both light-induced fading effects on thermoluminescence (TL) and optically stimulated luminescence (OSL) signals under three different light sources (fluorescent, UV-254 and daylight) and dose reassessment with phototransferred TL (PTTL) signals in Beryllium oxide dosimeters. TL and OSL signals were deconvoluted for each light source. Accordingly, variations in the maximum peak temperature, activation energy, peak area value for the TL signal, and intensity and lifetime values for the OSL signal were monitored. Each peak, OSL component, and total area value exhibited different behaviors depending on the light source. Considering the total area condition, the TL intensity decreased by ∼90%, ∼80%, and ∼70% in UV-254, daylight, and fluorescent light exposure, respectively, at the end of the 120 min. On the other hand, the OSL total area intensity faded quickly for both UV-254 and daylight, while it decreased by ∼45% for fluorescent light. According to these results, regardless of TL and OSL measurements, the dosimeters should be kept primarily away from daylight and fluorescent light after irradiation, instead of UV-254, which is rarely encountered in daily life. The feasibility of dose reassessment using PTTL signals under UV-254 light was investigated within a wide dose range from 0.1 to 128 Gy. It is feasible to reassess doses between 0.5 and 32 Gy considering the total area intensity of PTTL signals. In conclusion, PTTL signals can be easily used in fields of the order of Gy, such as in reevaluating doses in radiotherapy applications.

Light-Induced Antioxidant Phenolic Changes among the Sprouts of Lentil Cultivar.

Lentil is a leguminous crop with a high content of health-beneficial polyphenols. Lentil sprouts are popularly consumed in fresh vegetable markets, although their phytochemical qualities are not well understood. In this study, we investigated the accumulation of phenolics in lentil sprouts in response to photosynthetic and stress light qualities, including fluorescent light (FL), red LED (RL), blue LED (BL), ultraviolet A (UV-A), and ultraviolet B (UV-B). Three lentil cultivars, Lentil Green (LG), French Green (FG), and Lentil Red (LR), were used to evaluate sprouts grown under each light condition. The adequate light intensities for enhancing the antioxidant activity of lentil sprouts were found to be 11 W/m2 under photosynthetic lights (FL, RL, BL), and 1 W/m2 under stress lights (UV-A, UV-B). Subsequently, HPLC-ESI/Q-TOF MS analysis was conducted for the quantitative analysis of the individual phenolics that were accumulated in response to light quality. Four main phenolic compounds were identified: ferulic acid, tricetin, luteolin, and kaempferol. Notably, tricetin accumulation was significantly enhanced under BL across all three lentil cultivars examined. Furthermore, the study revealed that the other phenolic compounds were highly dependent on FL, BL, or UV-B exposure, exhibiting cultivar-specific variations. Additionally, the antioxidant activities of lentil extracts indicated that BL was most effective for LG and FG cultivars, whereas FL was most effective for enhancing antioxidant activity of LR cultivars as the sprouts grew.

Reappraisal of serum retinol-binding protein as a surrogate marker for retinol and discovery of a novel retinol estimation formula

Background & AimsSerum retinol (ROH) is commonly used for population level assessment of vitamin A status. High-performance liquid chromatography (HPLC) is considered most accurate method for measuring ROH. However, with the technical difficulty of using HPLC for routine assays, serum retinol-binding protein (RBP) measured by immunological assays is expected to be a surrogate marker for ROH, with reports of a close correlation between serum RBP and ROH. Nevertheless, RBP is not commonly tested to assess vitamin A status with concerns over RBP alterations under various physiopathological conditions. Thus, we reappraised the extent to which RBP could be used as a surrogate marker in representative disorders that alter serum RBP levels. As a related marker, diagnostic utility of transthyretin (TTR) was also evaluated. MethodsTo evaluate the reliability of ROH and RBP assays, specimen stability was assessed in terms of (1) storage at 25, 4, −20, and −80 ºC for 1−28 days, (2) five-cycle freeze-thawing, and (3) fluorescent light exposure for 1−14 days. Sources of variation (sex, age, body mass index [BMI], and drinking habits) and reference intervals for ROH, RBP, and TTR were determined in 617 well-defined healthy individuals. To investigate the influence of disorders that affect serum RBP, patients with five diagnostic groups were enrolled: 26 with chronic kidney disease (CKD); 13 with various malignancies in advanced stages (AdM), 12 with acute bacterial infections (ABI), 6 with liver cirrhosis (LC), and 26 with simple obesity (BMI ≥ 27 kg/m2). ResultsThe stability of RBP and ROH in serum was confirmed under all conditions. In healthy individuals, serum ROH, RBP, and TTR were appreciably high in males with a slight increase in proportion to age and BMI. The major-axis regression line between RBP (x) and ROH (y) in healthy individuals was y = x, with a correlation coefficient of 0.986. In the LC, AdM, and ABI groups, similar strong correlations were observed; however, the regression lines were shifted slightly rightward from the healthy group line, indicating a positive bias in estimating ROH. Interestingly, the same analyses between TTR and ROH revealed similar strong linear relationships in all groups; however, the regression line of each group showed a leftward (opposite) shift from the healthy group line. Based on these observations, we developed a novel regression model composed of RBP and TTR, which proved to be accurate in estimating ROH, even under these pathological conditions. ConclusionsThe perfect RBP-ROH correlation in healthy individuals indicates the utility of RPB as a surrogate marker for ROH. Nevertheless, under RBP-altered conditions, a slight overestimation of ROH is inevitable. However, when the TTR was tested together, the bias can be corrected almost perfectly using the novel ROH estimation formula comprising RBP and TTR.

ENHANCING WHITE OYSTER MUSHROOM CULTIVATION THROUGH LIGHT STIMULATION USING WHITE LED

This study aims to investigate the impact of different illumination durations on the yield of white oyster mushrooms cultivated in a controlled environment mushroom chamber, with a focus on the advantages of LED lighting over conventional lighting methods. The experiment considered various time exposures: 3, 6, 9, 12, 15, and 24 hours per day, while fluorescent light exposure for 12 hours per day served as the control group. Parameters such as mushroom weight, pileus diameter, stipe diameter, and stipe length were measured. Results indicated that the most significant fruiting bodies in terms of pileus diameter (105.76 mm) and stipe diameter (15.26 mm) were observed with a 15-hour illumination exposure. Conversely, the 12-hour exposure using fluorescent lamps resulted in the smallest pileus diameter, averaging 79.70 mm. Notably, a 3-hour exposure demonstrated the most substantial impact on yield, resulting in 182.4 g over two harvest cycles. In conclusion, treating white oyster mushrooms with white LED lighting can enhance productivity. This is primarily due to the excessive heat and higher light intensity generated by fluorescent lights, which can inhibit growth during the fruiting development stage. Therefore, adopting white LED lighting systems offers greater control over the ideal light intensity required for optimal mushroom growth.

Effect of light, food additives and heat on the stability of sorghum 3‐deoxyanthocyanins in model beverages

AbstractThis work aimed to evaluate the stability of sorghum 3‐deoxyanthocyanins (DXA) in model beverages (pH 3.5) elaborated with crude sorghum phenolic extract, containing ascorbic acid and sulphite, under fluorescent light exposure and subjected to heat treatment. There was no significant difference in the DXA degradation during storage under light exposure (24.16%) and absence of light (20.72%). DXA degradation did not differ in the presence of ascorbic acid during storage under light exposure (23.99–25.38%) and absence of light (19.87–21.74%). The addition of sulphite caused an initial bleaching reaction, but as a reversible reaction, the anthocyanin content was higher on the last day of storage compared to the first day. There were no significant differences in total anthocyanin content of all treatments subjected to the heat treatment (80 °C for 5 and 25 min). Thus, crude DXA are very stable under light, additives and heat, and may be useful as natural food colourants.

Interactions between abiotic factors and the bioactivity of biodynamic horn manure on the growth of garden cress (Lepidium sativum L.) in a bioassay

BackgroundThe use of biostimulants like humic substances is a promising innovative approach in agriculture to activate and sustain physiological plant processes. The development of specific bioassays is required to study their bioactivity in laboratory conditions. In previous investigations, a soil-less bioassay with cress seedlings (Lepidium sativum L.) was developed for a biostimulant used in the biodynamic agriculture, the horn-manure preparation (HMP), a fermented cow manure sprayed at low concentrations onto fields. Objectives of the present study were to refine the bioassay by investigating the interactions between the HMP bioactivity and the test factors (i) water volume, (ii) gravistimulation, and (iii) exposure to fluorescent light.ResultsThe interactions between the test factors and the HMP treatment were significant in all series (p < 0.05, Wald F-test). Water overdose and gravitropic stress reduced root growth (down to − 24.2% and − 19.9%, respectively, p < 0.0001, Tukey–Kramer test). The HMP treatment partly compensated these effects by enhancing root growth by (i) water overdose (up to + 4.3%, p = 0.048, n = 4), and (ii) gravitropic stress (up to + 9.5%, p = 0.0004, n = 8). (iii) Furthermore, under the combined stress factors, fluorescent light exposure enhanced the HMP enhancing effect (up to + 12.3%, p = 0.007, n = 6).ConclusionsThe HMP bioactivity appeared to consist of a compensatory mode of action regarding the stress factors water overdose and gravistimulation, and a synergetic interaction with fluorescent light exposure. The HMP seems to interact with the plant sensory systems, likely stimulating the plant’s adaptability to its environment by increasing self-regulating processes. The bioassay sensitivity was successfully increased by integrating these interactions in the experimental set-up and adjusting the growth environment. This approach can be used to adjust the bioassay to other biostimulants.

Tea catechin role in decreasing the oxidation of dairy beverages containing linseed oil.

Dairy beverages containing emulsified linseed oil is a suitable vehicle for delivering polyunsaturated fatty acids to consumers. However, these beverages are prone to oxidation. The purpose of this study was to evaluate the effect of adding various concentrations (0, 0.001, 0.01 and 0.1% (w/w)) of green tea extract (GTE) to dairy beverages (DB) containing linseed oil (2.0%, w/w), in order to inhibit lipid oxidation during storage at high temperature (50°C) or under fluorescent light exposure. During storage, the concentration of catechin (C), epicatechin (EC) and epicatechin gallate (ECG) were significantly reduced (P ≤ 0.05) and degradation rate was greater when the DB were exposed to light (C 35%, EC 74% and ECG 68%) as compared to high temperature (C 34%, EC 45% and ECG 49%). In DB without GTE, the conjugated dienes (CD) hydroperoxides concentration increased significantly (P ≤ 0.05) from 23 mmol kg-1 fat to 243 mmol kg-1 fat under 6-day-light exposition, and to 83 mmol kg-1 fat under 6-day-heat temperature. The addition of GTE significantly increased the antioxidant capacity of DB and reduced the formation of CD, propanal and hexanal, induced by light exposure or high temperature. GTE at 0.10% completely inhibited CD formation during the storage period and reduced propanal and hexanal concentrations below the threshold.

Deconvoluting Wavelengths Leading to Fluorescent Light Induced Inflammation and Cellular Stress in Zebrafish (Danio rerio)

Fluorescent light (FL) has been shown to induce a cellular immune and inflammatory response that is conserved over 450 MY of evolutionary divergence and among vertebrates having drastically different lifestyles such as Mus musculus, Danio rerio, Oryzias latipes and Xiphophorus maculatus. This surprising finding of an inflammation and immune response to FL not only holds for direct light receiving organs (skin) but is also observed within internal organs (brain and liver). Light responsive genetic circuitry initiated by the IL1B regulator induces a highly conserved acute phase response in each organ assessed for all of biological models surveyed to date; however, the specific light wavelengths triggering this response have yet to be determined so investigation of mechanisms and/or light specific molecule(s) leading to this response are difficult to assess. To understand how specific light wavelengths are received in both external and internal organs, zebrafish were exposed to specific 50 nm light wavebands spanning the visible spectrum from 300–600 nm and the genetic responses to each waveband exposure were assessed. Surprisingly, the induced cellular stress response previously observed following FL exposure is not triggered by the lower “damaging” wavelengths of light (UVB and UVA from 300–400 nm) but instead is maximally induced by higher wavelengths ranging from 450–500 nm in skin to 500–600 nm in both brain and liver).

The Role of Curcumin on Reduced Leukocyte and Platelet Counts in Rats After Exposure to Ultraviolet Light from Compact Fluorescent Lamps: A Morphological Study

Background: Compact fluorescent lamps (CFLs) could be a source of ultraviolet (UV) radiation with potential harmful effects. Objectives: We assessed the effects of ultraviolet radiation on leukocyte and platelet counts in rats and also investigated the preservative effects of curcumin on hematologic disorders caused by UV radiation. Methods: We randomly divided 48 male Sprague-Dawley rats into six groups (n = 8). Two control groups received ethyl oleate (0.2 mL, IP) for 10 (group I) and 30 days (group II), without exposure to fluorescent light. Two fluorescent groups treated daily with 12 hours fluorescent light exposure for 10 (group III) and 30 days (group IV). Group V and VI received curcumin (20 µmol, IP) and 12 hours fluorescent light exposure for 10 and 30 days, respectively. The blood samples were collected and the leukocyte indexes were measured by cell counter and blood smears were obtained. Results: The number of leukocytes was significantly lower in groups III (8.36 ± 0.23 × 103/µL) and IV (7.85 ± 0.18 × 103/µL) compared with groups I (8.78 ± 0.14 × 103/µL) and II (8.50 ± 0.20 × 103/µL). (P value III:I = 0.004, IV:II < 0.0001). The number of leukocytes insignificantly increased to normal levels of 8.85 ± 0.29 × 103/µL and 8.30 ± 0.16 × 103/µL in groups V and VI, respectively (P value V:I = 0.79, VI:II = 0.09). The number of platelets (PLTs) was significantly lower in the groups IV and VI in comparison with the group II (750 ± 6.52 × 103/µL, 808 ± 2.13 × 103/µL and 846 ± 2.73 × 103/µL, respectively (P value IV:II < 0.0001, VI:II < 0.0001). In the morphological pattern of leukocytes, the CFLs lead to atopic cells, bond cells, and cell lysis, however, administration of curcumin prevented this disturbance. Conclusions: Curcumin has a protective role in reducing complications caused by CFLs in reduced leukocyte and platelet counts, which is probably due to its antioxidant agent.

INHIBITORY EFFECT OF ASCORBIC ACID MICROEMULSION ON PHOTO-OXIDIZED VIRGIN COCONUT OIL

The effect of water-in-oil (w/o) microemulsion containing ascorbic acid on photo-oxidative stability of virgin coconut oil (VCO) was investigated. To optimize the formulation, w/o microemulsions were prepared using hydrophilic lipophilic balance (HLB) concept, consisted of ternary nonionic surfactants having low, medium, and high HLB values. From this optimum HLB number, the ratio of water, surfactant and oil was determined to obtain microemulsion areas. After optimization of the microemulsion system, the storage at room temperature, and the extreme condition were conducted for testing the microemulsion stability. Then, the stable formulas were used for delivering ascorbic acid. The solubility and photo-oxidative stability of ascorbic acid microemulsion were evaluated. The optimum formula of ascorbic acid microemulsion was applied into VCO at various concentrations (0, 1, 5, and 10% w/w). Samples were subjected to photo-oxidation under fluorescent light exposure of 4000 lux for up to 8 hours. Peroxide values (PVs) and p-anisidine values (p-AnVs) of the samples were measured at 1 hour interval. The results indicated that w/o microemulsion could be formed on the HLB number of 7. W/o microemulsion containing 75% oils need surfactant concentrations of ≥ 4.5 part of water, and if containing 77.78% oils, the surfactant concentration must ≥ 5.5 part of water. These microemulsions remained stable during storage at room temperature, even after centrifugation, but did not tolerate at high temperature. The maximum solubility of ascorbic acid in w/o microemulsion was 1%. Ascorbic acid microemulsion resistant to photo-oxidation and effective inhibits that reaction in VCO. This study confirmed that w/o microemulsion can act as ascorbic acid delivery system to disperse into VCO for inhibiting its’ quality deterioration due to photo-oxidation.

INHIBITORY EFFECT OF ASCORBIC ACID MICROEMULSION ON PHOTO-OXIDIZED VIRGIN COCONUT OIL

The effect of water-in-oil (w/o) microemulsion containing ascorbic acid on photo-oxidative stability of virgin coconut oil (VCO) was investigated. To optimize the formulation, w/o microemulsions were prepared using hydrophilic lipophilic balance (HLB) concept, consisted of ternary nonionic surfactants having low, medium, and high HLB values. From this optimum HLB number, the ratio of water, surfactant and oil was determined to obtain microemulsion areas. After optimization of the microemulsion system, the storage at room temperature, and the extreme condition were conducted for testing the microemulsion stability. Then, the stable formulas were used for delivering ascorbic acid. The solubility and photo-oxidative stability of ascorbic acid microemulsion were evaluated. The optimum formula of ascorbic acid microemulsion was applied into VCO at various concentrations (0, 1, 5, and 10% w/w). Samples were subjected to photo-oxidation under fluorescent light exposure of 4000 lux for up to 8 hours. Peroxide values (PVs) and p-anisidine values (p-AnVs) of the samples were measured at 1 hour interval. The results indicated that w/o microemulsion could be formed on the HLB number of 7. W/o microemulsion containing 75% oils need surfactant concentrations of ≥ 4.5 part of water, and if containing 77.78% oils, the surfactant concentration must ≥ 5.5 part of water. These microemulsions remained stable during storage at room temperature, even after centrifugation, but did not tolerate at high temperature. The maximum solubility of ascorbic acid in w/o microemulsion was 1%. Ascorbic acid microemulsion resistant to photo-oxidation and effective inhibits that reaction in VCO. This study confirmed that w/o microemulsion can act as ascorbic acid delivery system to disperse into VCO for inhibiting its’ quality deterioration due to photo-oxidation.

Mesenchymal stem cells as a possible therapy in experimentally induced retinal damage in Albino rat: Histological study

ABSTRACTIntroduction: Retinal degeneration had been increased as a common cause of blindness nowadays. Stem cells could be apromising therapy for treating retinal degeneration.Aim of the work: To investigate the possible role of BMSCs on the damaged retina resulting from continuous fluorescentlight exposure.Materials and Methods: Twenty- five albino rats (80- 100) gm were used in this study. Of which, 5 rats were used forpreparation of the BMSCs. The other twenty adult rats were divided into three groups. Rats of the control group were kept in12 hrs light/ 12 hrs dark. Rats of group II (fluorescent light exposure group) were exposed to two 20W white fluorescent lamps60 cm length continuously for 2 weeks at an illumination of 500 Lux. Group II rats were examined 8 weeks after fluorescentlight exposure. Group III animals were injected once by PKH 26–labeled BMSCs into the vitreous cavity of the eye at the endof the second week of fluorescent light exposure and kept for 8 weeks. Retinal specimens were prepared for light (LM) andelectron microscopic (EM) examination. Morphometric and statistical study was performed.Results: Sections of group II showed thinning and disorganization of outer segments. There were spaces and disorganizationof the cells of the outer and inner nuclear layers. Most ganglion cells had vacuolated cytoplasm and some appeared with densenuclei. Most of retinal cells had distorted organelles. Immunohistochemical reaction revealed significant increase in GFAPimmune reaction. Statistical analysis revealed a significant decrease in the thickness of most retinal layers. Meanwhile, groupIII retinas showed restoration of most of the histological structure.Conclusion: BMSCs could ameliorate retinal degeneration resulted from continuous fluorescent light exposure.

Exposure to excessive blue LED light damages retinal pigment epithelium and photoreceptors of pigmented mice

To determine the characteristics of the damages of the retinal pigment epithelium (RPE) and photoreceptors of pigmented mice induced by exposure to blue light emitting diode (LED) light, and to determine the mechanisms causing the damages. Exposure to blue LED light for 3 days induced retinal damage, and the characteristics of the damage differed from that induced by white fluorescent light exposure. Ophthalmoscopy showed that blue LED exposure for 3 days induced white spots on the retina, and histological examinations showed materials accumulated at the IS/OS junction of the photoreceptors. The accumulated materials were stained by ionized calcium binding adapter molecule-1 (Iba-1), a marker for macrophages. The debris was also positive for periodic acid-Schiff (PAS). An enlarging the area of RPE was detected just after the blue LED exposure especially around the optic nerve, and this led to a secondary degeneration of the photoreceptors. Exposure of pigmented mice to 3 consecutive days of blue LED light will cause RPE and photoreceptor damage. The damage led to an accumulation of macrophages and drusen-like materials around the outer segments of the photoreceptors. This blue light exposed model may be useful for investigating the pathogenesis of non-exudative age-related macular degeneration.

Waveband specific transcriptional control of select genetic pathways in vertebrate skin (Xiphophorus maculatus)

BackgroundEvolution occurred exclusively under the full spectrum of sunlight. Conscription of narrow regions of the solar spectrum by specific photoreceptors suggests a common strategy for regulation of genetic pathways. Fluorescent light (FL) does not possess the complexity of the solar spectrum and has only been in service for about 60 years. If vertebrates evolved specific genetic responses regulated by light wavelengths representing the entire solar spectrum, there may be genetic consequences to reducing the spectral complexity of light.ResultsWe utilized RNA-Seq to assess changes in the transcriptional profiles of Xiphophorus maculatus skin after exposure to FL (“cool white”), or narrow wavelength regions of light between 350 and 600 nm (i.e., 50 nm or 10 nm regions, herein termed “wavebands”). Exposure to each 50 nm waveband identified sets of genes representing discrete pathways that showed waveband specific transcriptional modulation. For example, 350–400 or 450–500 nm waveband exposures resulted in opposite regulation of gene sets marking necrosis and apoptosis (i.e., 350–400 nm; necrosis suppression, apoptosis activation, while 450–500 nm; apoptosis suppression, necrosis activation).Further investigation of specific transcriptional modulation employing successive 10 nm waveband exposures between 500 and 550 nm showed; (a) greater numbers of genes may be transcriptionally modulated after 10 nm exposures, than observed for 50 nm or FL exposures, (b) the 10 nm wavebands induced gene sets showing greater functional specificity than 50 nm or FL exposures, and (c) the genetic effects of FL are primarily due to 30 nm between 500 and 530 nm.Interestingly, many genetic pathways exhibited completely opposite transcriptional effects after different waveband exposures. For example, the epidermal growth factor (EGF) pathway exhibits transcriptional suppression after FL exposure, becomes highly active after 450–500 nm waveband exposure, and again, exhibits strong transcriptional suppression after exposure to the 520–530 nm waveband.ConclusionsCollectively, these results suggest one may manipulate transcription of specific genetic pathways in skin by exposure of the intact animal to specific wavebands of light. In addition, we identify genes transcriptionally modulated in a predictable manner by specific waveband exposures. Such genes, and their regulatory elements, may represent valuable tools for genetic engineering and gene therapy protocols.

Exploring Conditions for Ultrafine Particle Formation from Oxidation of Cigarette Smoke in Indoor Environments.

Cigarette smoke is an important source of particles and gases in the indoor environment. In this work, aging of side-stream cigarette smoke was studied in an environmental chamber via exposure to ozone (O3), hydroxyl radicals (OH) and indoor fluorescent lights. Aerosol mass concentrations increased by 13-18% upon exposure to 15 ppb O3 and by 8-42% upon exposure to 0.45 ppt OH. Ultrafine particle (UFP) formation was observed during all ozone experiments, regardless of the primary smoke aerosol concentration (185-1950 μg m-3). During OH oxidation, however, UFP formed only when the primary particle concentration was relatively low (<130 μg m-3) and the OH concentration was high (∼1.1 × 107 molecules cm-3). Online aerosol composition measurements show that oxygen- and nitrogen- containing species were formed during oxidation. Gas phase oxidation of NO to NO2 occurred during fluorescent light exposure, but neither primary particle growth nor UFP formation were observed. Overall, exposure of cigarette smoke to ozone will likely lead to UFP formation in indoor environments. On the other hand, UPF formation via OH oxidation will only occur when OH concentrations are high (∼107 molecules cm-3), and is therefore less likely to have an impact on indoor aerosol associated with cigarette smoke.

The transcriptional response of skin to fluorescent light exposure in viviparous (Xiphophorus) and oviparous (Danio, Oryzias) fishes

Differences in light sources are common in animal facilities and potentially can impact experimental results. Here, the potential impact of lighting differences on skin transcriptomes has been tested in three aquatic animal models commonly utilized in biomedical research, (Xiphophorus maculatus (platyfish), Oryzias latipes (medaka) and Danio rerio (zebrafish). Analysis of replicate comparative RNA-Seq data showed the transcriptional response to commonly utilized 4100K or “cool white” fluorescent light (FL) is much greater in platyfish and medaka than in zebrafish. FL induces genes associated with inflammatory and immune responses in both medaka and zebrafish; however, the platyfish exhibit suppression of genes involved with immune/inflammation, as well as genes associated with cell cycle progression. Furthermore, comparative analyses of gene expression data from platyfish UVB exposures, with medaka and zebrafish after exposure to 4100K FL, show comparable effects on the same stress pathways. We suggest the response to light is conserved, but that long-term adaptation to species specific environmental niches has resulted in a shifting of the wavelengths required to incite similar “genetic” responses in skin. We forward the hypothesis that the “genetic perception” of light may have evolved differently than ocular perception and suggest that light type (i.e., wavelengths emitted) is an important parameter to consider in experimental design.

Exposure to 4100 K fluorescent light elicits sex specific transcriptional responses in Xiphophorus maculatus skin

It has been reported that exposure to artificial light may affect oxygen intake, heart rate, absorption of vitamins and minerals, and behavioral responses in humans. We have reported specific gene expression responses in the skin of Xiphophorus fish after exposure to ultraviolet light (UV), as well as, both broad spectrum and narrow waveband visible light. In regard to fluorescent light (FL), we have shown that male X. maculatus exposed to 4100K FL (i.e. “cool white”) rapidly suppress transcription of many genes involved with DNA replication and repair, chromosomal segregation, and cell cycle progression in skin. We have also detailed sex specific transcriptional responses of Xiphophorus skin after exposure to UVB. However, investigation of gender differences in global gene expression response after exposure to 4100K FL has not been reported, despite common use of this FL source for residential, commercial, and animal facility illumination.Here, we compare RNA-Seq results analyzed to assess changes in the global transcription profiles of female and male X. maculatus skin in response to 4100K FL exposure. Our results suggest 4100K FL exposure incites a sex-biased genetic response including up-modulation of inflammation in females and down modulation of DNA repair/replication in males. In addition, we identify clusters of genes that become oppositely modulated in males and females after FL exposure that are principally involved in cell death and cell proliferation.

Vitamin Fortification of Fluid Milk.

Vitamin concentrates with vitamins A and D are used for fortification of fluid milk. Although many of the degradation components of vitamins A and D have an important role in flavor/fragrance applications, they may also be source(s) of off-flavor(s) in vitamin fortified milk due to their heat, oxygen, and the light sensitivity. It is very important for the dairy industry to understand how vitamin concentrates can impact flavor and flavor stability of fluid milk. Currently, little research on vitamin degradation products can be found with respect to flavor contributions. In this review, the history, regulations, processing, and storage stability of vitamins in fluid milk are addressed along with some hypotheses for the role of vitamin A and D fortification on flavor and stability of fluid milk.

Nitrate Content in Minimally Processed Lettuce (Lactuca sativa L.) as Affected by Fluorescent Light Exposure During Storage

Butter head lettuce (Lactuca sativa L.), a leafy vegetable commonly used in salads is characterized by its ability to accumulate high level of nitrate. Accumulation of nitrate in the edible part of the plant causes nitrate toxicity. Indeed, use of artificial light during storage, exploring new approach to prevent accumulation of nitrate. The objective of this study was to determine how light exposure during storage prevents accumulation of nitrate in butter head lettuce. Minimally processed lettuce in the form of leaf discs were stored in the dark and under fluorescent light at 5, 10 and 15 μmol m-2s-1 at 10°C (95% RH) for 14 days. The light treatments were provided for 12 hour’s photo period. Light exposure during storage significantly prevented nitrate accumulation, delayed degradation of chlorophylls and extends shelf life. In contrast in the darkness, nitrate content was accumulated while chlorophyll level was degraded. The delayed accumulation of nitrate under light can be because of the higher accumulation of soluble sugars, as changes in nitrate level and soluble sugar were found reverse. In conclusion, light exposure in the level applied successfully prevented nitrate accumulation, increasing the level of soluble sugars and delayed loss of chlorophyll pigment.

Retail lighting and packaging influence consumer acceptance of fluid milk

Little is known about the effect of retail light-emitting diode (LED) exposure on consumer acceptance of milk. The study objective was to determine effects of fluorescent and LED lighting under retail storage conditions on consumer acceptance of milk. Consumer acceptance of milk stored under retail conditions was determined through sensory evaluation (2 studies; n=150+ each) and analytical measures (dissolved oxygen, secondary oxidation products, riboflavin retention). Study 1 evaluated milk stored in high-density polyethylene (HDPE) packages for 4h under LED light (960 lx). Commercially available HDPE package treatments included translucent HDPE (most commonly used), white HDPE [low concentration (1.3%) TiO2], and yellow HDPE; in addition, HDPE with a higher TiO2 concentration (high white; 4.9% TiO2) and a foil-wrapped translucent HDPE (control) were tested. Translucent and control packages also were tested under fluorescent light. Study 2 evaluated polyethylene terephthalate (PET) packages for 4h under fluorescent and LED light (1,460 lx). The PET packaging included 2 treatments (medium, 4.0% TiO2; high, 6.6% TiO2) as well as translucent HDPE (exposed to fluorescent), clear PET (fluorescent and LED), and light-protected control. Overall mean acceptability of milk ranged from “like slightly” to “like moderately” with significantly lower acceptability for milk exposed to fluorescent light. Milk in HDPE and PET packages had comparable overall acceptability scores when exposed to LED light. Only the fluorescent light condition (both PET and HDPE) diminished overall acceptability. Fluorescent light exposure negatively influenced flavor with significant penalty (2.0–2.5 integers) to overall acceptability of milk in translucent HDPE and clear PET. The LED also diminished aftertaste of milk packaged in translucent HDPE. Changes in dissolved oxygen content, as an indication of oxidation, supported the observed differences in consumer acceptance of milk stored under fluorescent and LED light. Consumers like the flavor of fresh milk, which can be protected by selecting appropriate packaging that blocks detrimental light wavelengths.