Full Light Research Articles

Tapered Coaxial Arrays for Photon- and Plasmon-Enhanced Light Harvesting in Perovskite Solar Cells: A Theoretical Investigation Using the Finite Element Method.

Although there have been reports of separate studies of photon-enhanced and plasmon-enhanced light harvesting to improve perovskite solar cell (PSC) efficiency, there are none that have achieved simultaneous enhancement in both photonic and plasmonic effects in PSCs. In this work, we designed a layer of tapered coaxial humps (TCHs) to harvest both in PSCs. The light absorption behavior of the textured perovskite layer in PSCs was systematically investigated through the finite element method (FEM). The calculation results show that the TCH-textured perovskite layer absorbs 67.6 % of visible light under AM 1.5G solar irradiation, a 21.8 % increase relative to the planar reference cell without TCHs. Using this design, a perovskite thickness of only 106 nm is needed to realize the full light absorption that normally requires 300-nm-thick perovskite without TCHs. To reveal the mechanism of light absorption enhancement, the specific field distributions were studied. We demonstrated that different photonic modes and plasmonic modes collectively result in remarkable light absorption enhancement in the 500-800 nm wavelength range. The textured PSCs reported herein provide an effective method to decrease Pb-based perovskite consumption and realize angle-insensitive and ultrathin PSCs.

Highly-efficient and salt-resistant CsxWO3@g-C3N4/PVDF fiber membranes for interfacial water evaporation, desalination, and sewage treatment

In this work, cesium tungsten oxide/graphitic carbon nitride (Cs0.32WO3@g-C3N4) hybrids were successfully synthesized using a facile solvothermal method. The hybrids were incorporated into PVDF and electrospun into Cs0.32WO3@g-C3N4/PVDF fiber membranes. Water evaporation, desalination, and sewage treatment were studied using the photothermal fiber membranes. The experimental results showed that the highest photothermal conversion could be achieved for a fiber membrane composed of 10 wt% of Cs0.32WO3@g-C3N4. The highest temperature elevations measured were 85 °C and 90 °C under NIR and full solar light, respectively. The membranes exhibited excellent anti-salt fouling behavior while also demonstrating superior water evaporation efficiency and salt rejection 95.4% and 99.9%, respectively. Furthermore, the electrospun fiber membranes showed excellent efficiencies for removing organic dyes, 4-nitro phenol and tetracycline. These superior properties are attributed to the hydrophobicity of PVDF, which enables an air gap to form between the water and the fiber membrane. This air gap selectively admits water vapor into the fiber membrane while salt and organic pollutants diffuse back to bulk water, which is critical for the successful of desalination. This study opens the door to design new multi-functional fiber membranes for sewage treatment, especially for desalination.

Influence of light, water motion, and stocking density on the growth and pigment content of Halymenia durvillei (Rhodophyceae) under laboratory conditions

The tropical red seaweed Halymenia durvillei Bory de Saint Vincent is a potential source of the high-value pigments, r-phycoerythrin (RPE) and r-phycocyanin (RPC). The unique properties of these pigments find many applications—from food to cosmetics, pharmaceuticals, and biomedical research. This study aimed to improve the land-based culture technology of H. durvillei by determining the appropriate combination of light, water motion, and stocking density that would result in high growth performance and high RPE and RPC content. Combinations of two light levels (full light, 100% and reduced light, 67%), two water motion levels (low and moderate), and three stocking densities (50, 100, and 200 g) were studied using 64.5-L glass tanks with flow-through seawater and aeration systems at the outdoor land-based seaweed nursery in Bolinao, Pangasinan, Philippines. After 6 weeks of culture, growth performance (growth rate and productivity) of H. durvillei and phycobiliprotein content were best under a combination of full light (100%), moderate water motion, and 50-g stocking density. The generally low light regime during the experimental period, which coincided with the cold, dry season characterized by shorter days and overcast skies, may have influenced H. durvillei to maximize the use of available resources such as light and possible increased nutrient availability from water motion to promote growth and phycobiliprotein synthesis. Treatments with low stocking densities generally showed satisfactory growth and phycobiliprotein content. This study provides groundwork for future research into mechanisms by which these and other factors affect the growth and physiology of H. durvillei in culture.

Compressive spectral image fusion via a single aperture high throughput imaging system

Spectral image fusion techniques combine the detailed spatial information of a multispectral (MS) image and the rich spectral information of a hyperspectral (HS) image into a high-spatial and high-spectral resolution image. Due to the data deluge entailed by such images, new imaging modalities have exploited their intrinsic correlations in such a way that, a computational algorithm can fuse them from few multiplexed linear projections. The latter has been coined compressive spectral image fusion. State-of-the-art research work have focused mainly on the algorithmic part, simulating instrumentation characteristics and assuming independently registered sensors to conduct compressed MS and HS imaging. In this manuscript, we report on the construction of a unified computational imaging framework that includes a proof-of-concept optical testbed to simultaneously acquire MS and HS compressed projections, and an alternating direction method of multipliers algorithm to reconstruct high-spatial and high-spectral resolution images from the fused compressed measurements. The testbed employs a digital micro-mirror device (DMD) to encode and split the input light towards two compressive imaging arms, which collect MS and HS measurements, respectively. This strategy entails full light throughput sensing since no light is thrown away by the coding process. Further, different resolutions can be dynamically tested by binning the DMD and sensors pixels. Real spectral responses and optical characteristics of the employed equipment are obtained through a per-pixel point spread function calibration approach to enable accurate compressed image fusion performance. The proposed framework is demonstrated through real experiments within the visible spectral range using as few as 5% of the data.

Physiological and transcriptomic responses of Mikania micrantha stem to shading yield novel insights into its invasiveness

The rapid stem elongation of the invasive weed Mikania micrantha in the forest understory is of vital significance for its successful invasion. To understand the physiological and molecular mechanisms for this process, here we comparatively investigated the physiological characteristics and transcriptome patterns of M. micrantha stem under low light (30%) and full light (100%) conditions. The results showed that M. micrantha stem had photosynthetic capacity, which was highly plastic to light intensities, constituting an indispensable part of the plastic response of M. micrantha to shading. M. micrantha had longer internodes, epidermal cells, and consequently longer stems under low light than full light conditions, which could proximally be attributed to phytohormone production and reduction of photoprotective substances as potential metabolic trade-off, as observed here under shading treatment. The transcriptome sequencing and qPCR verified the results from physiological investigation, and showed that under low light condition the expression levels of genes involved in photosynthesis (e.g. MmPsaA, MmPsbO1 and MmFd3) were generally down-regulated in comparison to full light condition, as were genes related to the photoprotective substances synthesis (e.g. MmCHS, and MmF3H1) and the negative regulators of phytohormone (e.g. MmAUX1, MmRR1 and MmGAI). It was concluded that the regulation of phytohormones and photoprotective substances are important material basis for the rapid elongation of M. micrantha stems with high plasticity, which facilitates the vine's invasiveness in the forest understory.

Daily full spectrum light exposure prevents food allergy-like allergic diarrhea by modulating vitamin D3 and microbiota composition

The importance of sun exposure on human health is well recognized, and a recent trend in the avoidance of sun exposure has led to the risk of missing the beneficial effects such as vitamin D3 biogenesis. Vitamin D3 insufficiency is one of the risk factors for the development of food allergies (FAs), and vitamin D3 status controls gut homeostasis by modulating the microbiota. This study aimed to explore the impact of daily full spectrum light exposure (phototherapy) on the pathogenesis of FAs. Phototherapy ameliorated allergic diarrhea and improved FA-associated vitamin D3 insufficiency and dysbiosis. Fecal microbiota transplantation (FMT) of FA donor feces induced allergic diarrhea with OVA-specific IgE elevation in naïve mice. In contrast, FMT of naïve donor feces ameliorated allergic diarrhea in established FA mice, suggesting the involvement of the microbiota composition in FA. Phototherapy is an alternative approach for the prevention of FA-like allergic diarrhea through the modulation of vitamin D3 status and microbiota composition.

Protective effects of aqueous extracts from Sedum sarmentosum growing under different light intensity on CCl_4-induced damage in HepG2 cells

To explore the effect of light intensity in cultivating environment on the hepetoprotective activity of Sedum sarmentosum, S. sarmentosum were planted under five water treatments for 60 days, namely 100% full sunlight(G1), 77% full sunlight(G2), 60% full sunlight(G3), 38% full sunlight(G4), and 16% full sunlight(G5) and CCl_4 drug-induced liver injury model in vitro was used. Cell viability, cell cycle, and cell apoptosis were individually detected by MTT, PI single staining, and Annexin-V FITC/PI double staining assays. Additionally, ALT, AST and antioxidant index in supernatant were determined by colorimetry. And the relationship among the protective effects, chemical composition and antioxidant activity were also analyzed. The results showed that S. sarmentosum aqueous extract could significantly improve the HepG2 cell viability. Among the five S. sarmentosum groups, the cell viability of G1(100% full sunlight) treatment was the highest, and the cell apoptosis was the least. Meanwhile, the level of ALT, AST, and MDA in G1 was the lowest, but it achieved the highest level of SOD and GSH. Moderate light shading(60% full light) also improved the effect of protecting liver and reducing the enzyme. It was found that cell viability was positively correlated with ferricion reducing capacity. ALT activity was positively correlated with isorhamnetin content. Taken together, different light intensity had great influence on hepatoprotective effect of S. sarmentosum, which may be related to its antioxidant capacity. From the perspective of hepetoprotective activity, S. sarmentosum should be planted under full light.

Apple tree adaptation to shade in agroforestry: an architectural approach.

The expression of shade adaptation traits is expected to be stronger in low light and can be detrimental to flowering and yield. Our study focused on the expression of shade adaptation traits of apple trees (Malus domestica Borkh. 'Dalinette') in an agroforestry system. The architecture of 45 apple trees in their third and fourth year was extensively described and analyzed at the tree scale and compared depending on the light quantity received during the growing season. Flower cluster phenology and the relation between leaf area and floral initiation were also investigated. The number of growing shoots and the leaf area were reduced by shade even if specific leaf area increased with increasing shade. Shade did not modify primary growth but did decrease secondary growth, so that apple tree shoots in shade were slender, with a lower taper and reduced number and proportion of flower clusters. The correlation between floral initiation and leaf area was high both in full and moderate light but not for apple trees in low light. Shade did not impact the date of bud burst and the early phenological stages of flower clusters, but it reduced the number of days at full bloom. Our results suggest that while the architecture of apple trees is modified by a reduction in light intensity, it is not until a reduction of 65% that the capability to produce fruit is impeded. These results could help optimize the design of apple-tree-based agroforestry systems.

Aurivillius compound Bi5Ti3CrO15 as a visible-light-active photocatalyst for hydrogen production from water

Layered Aurivillius compound Bi5Ti3CrO15 has been synthesized by a hydrothermal method for the application as a photocatalyst to liberate hydrogen from water. Bi5Ti3CrO15 owns a narrow band gap (Eg ~2.46 eV) and shows stable photocatalytic activity under both full range (λ ≥250 nm) and visible light illumination (λ ≥420 nm). A short hydrothermal reaction time is critical to achieve high photocatalytic activity as defects such as Cr6+ and Bi5+ can be avoided. An AQE as high as 3.66% at 420 nm ± 20 nm has been recorded, warranting promising application in the field of solar energy conversions. DFT calculation reveals the important role of Cr3+cations for visible light sensitivity of Bi5Ti3CrO15.

Band structure engineering enables to UV-Visible-NIR photocatalytic disinfection: Mechanism, pathways and DFT calculation

Photocatalytic disinfection has been regarded as a promising strategy in terms of significantly reducing microbial contamination, in which the activity of photocatalyst mainly depends on UV or visible light, however the effect of full spectrum solar light for photocatalytic disinfection has been rarely considered. Herein, we report a UV-Visible-NIR responsive photocatalyst based on vanadate quantum dots (AgVO3 QDs) interspersed on vacancy-rich BiO2-X (AgVO3/BiO2-X) and achieve highly efficient photocatalytic disinfection for Methicillin-resistant Staphylococcus aureus (MRSA). With our approach, we achieved a 7-log inactivation of bacterial concentration within 30 min, with only a small amount of material (200 μg mL−1) under UV, visible and near-infrared light. The maximum absorption edge of AgVO3/BiO2-X red-shifts from 880 nm to 930 nm, which can be attributed to the inner defective structure and formation of heterostructures, resulting in abundant production of reactive oxygen species (ROS) for bacterial inactivation. DFT calculations confirm the intimate interface contact between BiO2-X and AgVO3, which benefit to the up-conversion photoluminescence properties of AgVO3 QDs and fast interfacial electron transport through the electron tunneling mechanism. In vitro results illustrated that ROS can severely damage the cell wall of bacteria and inhibit its virulence factors, which eventually leading to the death of MRSA. Notably, assessment of wound infection showed that the material was very effective for promoting cell proliferation and differentiation, by phosphorylation of protein kinase B (Akt) signalling pathway in bacterial infection, which shows great potential as a safe, low-cost and efficient multimodal heterostructured photocatalyst in eliminating the microbial contaminated water.

New insights into sub-barrier fusion of 28Si + 100Mo

Fusion cross sections of the 28Si + 100Mo system have been measured near and below the Coulomb barrier by detecting the evaporation residues at forward angles. The excitation function has an overall smoother trend than what obtained in a previous experiment, and a large discrepancy is found for the lowest-energy region, where we observe a tendency of the S factor to develop a maximum, which would be a clear indication of hindrance. The results have been compared with the theoretical prediction of coupled-channels calculations using a Woods–Saxon nuclear potential, and including the low-energy excitation modes of both nuclei. Good agreement with data is found by including, in the coupling scheme, the three lowest members of the ground state rotational band of the oblate deformed 28Si, and two-phonons of the strong quadrupole vibration of 100Mo. The additional coupling, in a schematic way, of the two-neutron pick-up between ground states (Q-value = +4.86 MeV) has a minor effect on calculated cross sections, and does not essentially improve the data fit. The excitation function of 28Si + 100Mo has been compared with that of (1) the heavier system 60Ni + 100Mo having analogous features, and (2) several near-by 28Si, 32S + Zr, Mo systems with various nuclear structures and transfer Q-values. The role of quadrupole and octupole excitation modes, as well as of transfer channels, in affecting the fusion dynamics, are clarified to some extent. Systematic measurements of fusion barrier distributions and CC calculations properly including transfer couplings, are necessary, in order to shed full light on the influence of the various coupled channels on the fusion cross sections.

Photo-thermal synergy for boosting photo-Fenton activity with rGO-ZnFe2O4: Novel photo-activation process and mechanism toward environment remediation

Full light photo-Fenton and photo-thermal effect are of great importance but deserve attentions far insufficient in advanced oxidation progresses for extensive environmental remediation. Herein, ultraviolet-visible-near infrared (UV–vis-NIR) light absorbance and photo-thermal conversion were induced into H2O2 activation towards refractory antibiotics elimination from wastewater through green recyclable rGO-ZnFe2O4 developed via ultrasonic method. Interestingly, photo-thermal synergy presents much superior performance than that of solely photo-Fenton or thermal-Fenton process. Multiple light reflection inner ZnFe2O4 microsphere strengthens UV–vis capture and thermal conversion in degradation reaction. Orbital hybridization and electron rearrangement endow rGO-ZnFe2O4 wide NIR absorbency, fast thermal transfer and photo-generated electrons-holes separation for photo-thermal Fenton progress. Degradation rate of ciprofloxacin on rGO-ZnFe2O4 is found 3 times of ZnFe2O4 under full light exposure which can heat solution from room temperature to 70 °C, while 4 times under NIR irradiation where solution is heated to 46 °C. The great differences are mainly originated from photo-induced thermal energy, which in-situ heating active sites to lower H2O2 activation barrier, accelerate Fe2+/Fe3+ cycle and facilitate spread of radicals. Radicals contribute in OH > h+ > O2− under full light irradiation, while perform in h+ > O2− >OH when taking away photo-generated heat. Results based on systematic experiments and theory calculation imply the strong potential of photo-thermal Fenton in pollutants control, which proposes novel strategy in Fenton reaction for environmental remediation with effective utilization of solar energy.

Photometric studies of the short-period eclipsing binary V1094 Her and MT Cas

We obtained three new full BVRI light curves for two eclipsing binaries V1094 Her and MT Cas on nine nights from 2015 to 2018 using two optical telescopes. We analysed the orbital period variations using all available light curve minima, seven of which were from our work. For V1094 Her, we found that there is a cyclic variation overlaying a continuous period decrease. The cyclic variation of V1094 Her may be caused by the light-time effect by a third body of $$P_{3}=13.2(\pm 1.2)$$ yr or magnetic activity cycle with $$T=15.1(\pm 0.8)$$ yr. The decreasing period of V1094 Her can be explained by either mass exchange $${\dot{M}}_{2}=-2.20\times 10^{-7}\; M_{\odot }$$ /yr for a third body or $${\dot{M}}_{2}=-2.03\times 10^{-7}\; M_{\odot }$$ /yr for magnetic activity cycle. We confirmed there exist a period increase for MT Cas. For MT Cas, the secular decrease of period can be explained by the mass exchange $${\dot{M}}_{1}=-1.09\times 10^{-8}\; M_{\odot }$$ /yr (including angular momentum loss of $${\dot{M}}=-5.99\times 10^{-11}\; M_{\odot }$$ /yr). We obtained the orbital parameters for V1094 Her using the Wilson & Devinney program for the first time. For MT Cas, we updated their orbital parameters, which are similar to the results from previous work. We concluded that V1094 Her and MT Cas are contact eclipsing binaries with low contact factors and period variations.

Effects of clonal integration on allelopathy of invasive plantWedelia trilobataunder heterogeneous light conditions

AbstractPlant invasion is one of the most serious threats to ecosystems worldwide. When invasive plants with the ability of clonal growth invading or colonizing in new habitat, their interconnected ramets may suffer from heterogeneous light. Effects of clonal integration on allelopathy of invasive plants are poorly understood under heterogeneous light conditions. To investigate the effects of clonal integration on allelopathy of invasive plant Wedelia trilobata under heterogeneous light conditions, a pot experiment was conducted by using its clonal fragments with two successive ramets. The older ramets were exposed to full light, whereas the younger ones were subjected to 20% full light. The younger ramets of each clonal fragment were adjacently grown with a target plant (one tomato seedling) in a pot. Stolon between two successive ramets was either severed or retained intact. In addition, two tomato seedlings (one as target plant) were adjacently grown in a pot as contrast. Compared with severing stolon, biomass accumulation, foliar chlorophyll and nitrogen contents, chlorophyll fluorescence parameters and net photosynthetic rates of the target plants as well as their root length and activity, were significantly decreased when stolon between interconnected ramets of W. trilobata retained intact. Under heterogeneous light conditions, transportation or sharing of carbohydrate between two successive ramets enhanced allelopathy of the young ramets subjected to 20% full light treatment. It is suggested that clonal integration may be important for invasion or colonization of invasive plants with ability of clonal growth under heterogeneous light conditions.

Genotypic features of photosynthetic activity of leaves of spring wheat plants in connection with the selection of new types of varieties

The article is devoted to the results of research on species and genotypic features of photosynthetic activity in spring wheat plants in connection with the creation of varieties that form a high, stable, high-quality and environmentally safe crop due to the effective use of renewable natural energy of the sun by photosynthesis. It was found that the intensity of leaf photosynthesis in a culture significantly depends on the hereditary characteristics of plants, the growth phase, location, time of day, and lighting conditions. The range of genotypic changes in the trait in 2017 was 9.65-16.35, in 2018 – 9.55 – 21.42, in 2019 – 8.73 – 17.15 ?mol CO2/m2s. In the phase of tillering and milk ripeness in crop varieties, the most significant manifestation of CO2 gas exchange activity by leaves is noted. In the tillering phase, varieties with high photosynthesis intensity were 30% superior, and in the milk ripeness phase, varieties with low photosynthesis intensity were 31% superior. The most active is the absorption of CO2 molecules from the air by the flag leaf of plants. During the period of grain formation, the intensity of photosynthesis exceeded the pre – flagged leaf by an average of 1.6 times, and the lower-lying leaf by 2.8 times. This shows a high dependence of the intensity of leaf photosynthesis on the light regime. When the light intensity increased from 300 to 1000 ?mol/m2s, the photosynthesis intensity of the flag leaf of spring wheat plants increased by an average of 102 %, and above 1000 ?mol/m2sby 14 %. Of the studied varieties, the most responsive to the conditions of insolation is Volnodonskaya, Lyubava, Chernozem-Uralskaya, in which the full light saturation of photosynthesis was observed at 1800 ?mol/m2s. The correlation coefficient between the intensity of photosynthesis and illumination was 0.93.

Light Intensity Influence on Growth and Photosynthetic Characteristics of Horsfieldia hainanensis

Due to both anthropogenic and natural causes, the number of Horsfieldia hainanensis has been decreasing each year in the Tongza Branch nursery (109.534 525°E, 18.763 516°N) of the Hainan Academy of Forestry, China. Consequently, the protection of H. hainanensis is urgent, as is that of most rare tree species. To develop a more comprehensive understanding of the H. hainanensis growth environment, we took 3-year-old H. hainanensis saplings as the research object. We controlled the light intensity by setting different shade amounts to explore the growth and photosynthetic characteristics of H. hainanensis under different light intensities. We found that shade can promote growth and increase the contents of certain substances. Light transmittance of 44.41% can increase plant height (by 29.545%) and biomass (by 66.676%). Light transmittance of 16.19% can increase the pigment content; Chl increased by 40.864%, Chl a increased by 38.031%, and Chl b increased by 48.412%. Light transmittance of 7.30% can increase the soil plant analysis development (SPAD) value of each part of the leaf; the leaf base increased by 41.000%, the leaf margin increased by 32.574%, the blade tip increased by 49.003%, and the leaf average increased by 40.466%. The specific leaf area can reduce the specific leaf weight. We also found that compared to full light, reducing the light transmittance can increase the total chlorophyll (Chl), chlorophyll A (Chl a), and chlorophyll B (Chl b) contents, and the Chl-SPAD-leaf base, leaf edge, leaf tip, average content, and light-saturated net photosynthetic rate. This can in turn reduce the apparent quantum efficiency (AQY), light compensation point (LCP), and dark respiration rate (Rd). In addition, we found a strong correlation between seven of the photosynthetic pigment indicators (Chl, Chla, Chl b, Chl-SPAD-leaf base, leaf margin, leaf tip, and mean) and the three photosynthesis physiological parameters (AQY, LCP, and Rd). The light transmittance of 44.41% (one layer of shading net) treatment group was conducive to the growth of H. hainanensis and photosynthetic characteristic improvement. Therefore, our light transmittance selection of approximately 44.4% is significant for the natural return of H. hainanensis.

Selectively recombining the photoinduced charges in bandgap-broken Ag3PO4/GdCrO3 with a plasmonic Ag bridge for efficient photothermocatalytic VOCs degradation and CO2 reduction

State-of-the-art heterojunctions, such as Type II and Z-scheme, require overlap of the bandgaps between semiconductors, which induces trade-off among light response range, charge carrier separation efficiency and redox potentials of the photothermocatalyst, leading to the difficulty in finding suitable semiconductor candidates and improving sustainably the performance. Herein, we provide a strategy to activate the bandgap-broken Ag3PO4/GdCrO3 heterojunction with small band gaps, very negative conduction band, and high valence band value for constructing a robust photothermocatalyst through inserting plasmonic metal Ag nanoparticles at Ag3PO4-GdCrO3 interface as a bridge for selective capture and interband transfer of the photothermal induced charges. The as-developed Ag3PO4/Ag/GdCrO3 heterojunction simultaneously exhibits full visible light response, efficient carriers separation, and high redox potentials. Thereby, Ag3PO4/Ag/GdCrO3 exhibits 22 times higher photothermocatalytic toluene degradation rate than Ag3PO4/GdCrO3, and ranges among the best of the state-of-the-art photocatalytic or photothermocatalytic performance in both VOCs oxidation and CO2 reduction.

A Multi–Observing Technique Study of the Dynamical Evolution of the Viscous Disk around the Be Star ω CMa

Abstract The observed emission lines of Be stars originate from a circumstellar Keplerian disk, which is generally well explained by the viscous decretion disk model. In an earlier work we performed modeling of the full light curve of the bright Be star ω CMa with the 1D time-dependent hydrodynamic code SINGLEBE and the Monte Carlo radiative transfer code HDUST. We used a V-band light curve that probes the inner disk through four disk formation and dissipation cycles. This new study compares predictions of the same set of model parameters with time-resolved photometry from the near-UV through the mid-IR, comprehensive series of optical spectra, and optical broadband polarimetry, which overall represent a larger volume of the disk. Qualitatively, the models reproduce the trends in the observed data due to the growth and decay of the disk. However, quantitative differences exist, e.g., an overprediction of flux increasing with wavelength, too slow decreases in Balmer emission line strength during disk dissipation, and a discrepancy between the range of polarimetric data and the model. We find that a larger value of the viscosity parameter alone or a disk truncated by a companion star reduces these discrepancies by increasing the dissipation rate in the outer regions of the disk.

Interpretation of the difference in shade tolerance of two subtropical forest tree species of different successional stages at the transcriptome and physiological levels.

Differences in plant shade tolerance constitute a major mechanism driving the succession of forest communities in subtropical forests. However, the indirect effects of differences in light requirements on the growth of mid- and late-successional tree species are unclear, and this potential growth effect has not been explained at the transcriptome level. Here, a typical mid-successional dominant tree species, Schima superba Gardn. et Champ, and a typical late-successional dominant tree species, Cryptocarya concinna Hance were used as materials and planted under 100% full light (FL) and 30% FL (low light, LL) to explore the responses of tree species in different successional stages of subtropical forests to different light environments. Transcriptome sequencing was used to analyze the expression changes in genes related to growth and photoprotection under different light environments. The young leaves of S. superba accumulated more malondialdehyde (MDA) and superoxide radicals (${\mathrm{O}}_2^{{{}^{\bullet}}^{-}}$) under LL. A lower hormone content (auxin, cytokinin, gibberellin) in the young leaves, a weaker photosynthetic capacity in the mature leaves and significant downregulation of related gene expression were also found under LL, which resulted in the total biomass of S. superba under LL being lower than that under FL. The young leaves of C. concinna had less MDA and ${\mathrm{O}}_2^{{{}^{\bullet}}^{-}}$, and a higher hormone contents under LL than those under FL. There was no significant difference in photosynthetic capacity between mature leaves in contrasting light environments. Although the biomass of C. concinna under LL was less than that under FL, the height of C. concinna under LL was higher than that under FL, indicating that C. concinna could grow well under the two light environments. Our results describing the acclimatization of light at the physiological, molecular and transcriptome levels are important for a complete understanding of successional mechanisms.

The effects of bright white light therapy on obese frailty in older men with prostate cancer on hormonal therapy: A pilot randomized control trial.

75 Background: Exposure to bright white light (BWL) has been shown to improve outcomes including fatigue, depression, and sleep disturbances among the general older population but the benefit has not been demonstrated as yet in prostate cancer. Older men with prostate cancer on androgen deprivation therapy (ADT) are at risk for obese frailty (components: fatigue, weakness, poor mood, slowness and obesity). In this pilot study, we aimed to determine if BWL, compared to dim white wight (DWL), reduces obese frailty in older prostate cancer patients starting anti-androgens. Methods: Men age ≥ 65 with prostate cancer initiating ADT were randomly assigned to either the BWL (exposure to full spectrum light, 500-1500 lux) or DWL cohort (exposure to low dose white light (<50 lux)) and were blinded to assignment. Men received daily 30-minute morning light session from special glasses (Luminette) for 3 months. Participants were assessed at the beginning of treatment and 3 months later with the Short Physical Performance Battery (SPPB) - including timed 4m walk, tandem balance, and timed chair stands (range: 0 to 12) - energy levels (self-reported 5-point Likert scale), waist circumference (measured via tape (mm)), and muscle strength (handgrip: assessed via dynamometer (kg)). Pre-post outcomes (means differences) were evaluated using paired t-tests with a p-value of 0.05 considered significant. Results: 18 patients (9 per cohort) were recruited. Patients in the BWL arm showed a statistically significant improvement in muscle strength (BWL p=0.012 versus in DWL p=0.22). Compared with DWL, BWL arm showed no decline in energy levels, (BWL p=0.28 vs. DWL p=0.035) nor gain in waist circumference (BWL p=0.51, DWL p=0.046). There were no statistically significant differences in either arm on the SPPB (BWL p=0.44, and in DWL p=0.09). Conclusions: BWL may offset negative effects of ADT for older men with prostate cancer, through improved muscle strength, maintained energy levels, and no waist circumference gain. While a small pilot study, the intervention warrants further research in a larger sample.