Far-red light: A regulator of plant morphology and photosynthetic capacity

Plant photosynthetic capacity directly determines crop yield. Light quality regulates photosynthetic capacity. This review discusses plant responses to far-red light from the phenotypic to the molecular level, focusing specifically on the improvement of photosynthetic capacity by adjustment of photosynthetic electron transport and the path of light energy. Far-red light can also regulate leaf angle and increase plant height and leaf area, via expression of associated genes, to capture more light energy.Thus, far-red light regulates plant morphology and photosynthetic capacity. Identifying the mechanism of this regulation may lead to increased crop yields.

Overhead supplemental far-red light stimulates tomato growth under intra-canopy lighting with LEDs

Far-red(FR) light regulates phytochrome-mediated morphological and physiological plant responses.This study aims to investigate how greenhouse tomato morphology and production response to different durations of FR light during daytime and at the end of day(EOD).High-wire tomato plants were grown under intra-canopy lighting consisting of red(peak wavelength at 640 nm) and blue(peak wavelength at 450 nm) light-emitting diodes(LEDs) with photosynthetic photon flux density(PPFD) of 144 μmol m–2 s–1 at 10 cm away from the lamps,and combined with overhead supplemental FR light(peak wavelength at 735 nm) with PPFD of 43 μmol m–2 s–1 at 20 cm below the lamps.Plants were exposed to three durations of FR supplemental lighting including: 06:00–18:00(FR12),18:00–19:30(EOD-FR1.5),18:00–18:30(EOD-FR0.5),and control that without supplemental FR light.The results showed that supplemental FR light significantly stimulated stem elongation thereby resulting in longer plants compared with the control.Moreover,FR light altered leaf morphology toward higher leaf length/width ratio and larger leaf area.The altered plant architecture in FR supplemented plants led to a more homogeneous light distribution inside the canopy.Total plant biomass was increased by 9–16% under supplemental FR light in comparison with control,which led to 7–12% increase in ripe fruit yield.Soluble sugar content of the ripe tomato fruit was slightly decreased by longer exposure of the plants to FR light.Dry matter partitioning to different plant organs were not substantially affected by the FR light treatments.No significant differences were observed among the three FR light treatments in plant morphology as well as yield and biomass production.We conclude that under intra-canopy lighting,overhead supplemental FR light stimulates tomato growth and production.And supplementary of EOD-FR0.5 is more favorable,as it consumes less electricity but induces similar effects on plant morphology and yield.

<i>Pinus taeda</i>cDNA Microarray as a Tool for Candidate Gene Identification for Local Red/Far-Red Light Adaptive Response in <i>Pinus sylvestris</i>

Light quality response is a vital environmental cue regulating plant development. Conifers, like angiosperms, respond to the changes in light quality including the level of red (R) and far-red (FR) light, which follows a latitudinal cline. R and FR wavelengths form a significant component of the entire plant life cycle, including the initial developmental stages such as seed germination, cotyledon expansion and hypocotyl elongation. With an aim to identify differentially expressed candidate genes, which would provide a clue regarding genes involved in the local adaptive response in Scots pine (Pinus sylvestris) with reference to red/far-red light;we performed a global expression analysis of Scots pine hypocotyls grown under two light treatments, continuous R (cR) and continuous FR (cFR) light;using Pinus taeda cDNA microarrays on bulked hypocotyl tissues from different individuals, which represented different genotypes. This experiment was performed with the seeds collected from northern part of Sweden (Ylinen, 68?N). Interestingly, gene expression pattern with reference to cryptochrome1, a blue light photoreceptor, was relatively high under cFR as compared to cR light treatment. Additionally, the microarray data analysis also revealed expression of 405 genes which was enhanced under cR light treatment;while the expression of 239 genes was enhanced under the cFR light treatment. Differentially expressed genes were re-annotated using Blast2GO tool. These results indicated that cR light acts as promoting factor whereas cFR antagonises the effect in most of the processes like C/N metabolism, photosynthesis and cell wall metabolism which is in accordance with former findings in Arabidopsis. We propose cryptochrome1 as a strong candidate gene to study the adaptive cline response under R and FR light in Scots pine as it shows a differential expression under the two light conditions.

The red/far-red light photoreceptor FvePhyB regulates tissue elongation and anthocyanin accumulation in woodland strawberry

Light is an important environmental signal that influences plant growth and development.Among the photoreceptors,phytochromes can sense red/far-red light to coordinate various biological processes.However,their functions in strawberry are not yet known.In this study,we identified an EMS mutant,named P8,in woodland strawberry(Fragaria vesca)that showed greatly increased plant height and reduced anthocyanin content.Mapping-by-sequencing revealed that the causal mutation in FvePhyB leads to premature termination of translation.The light treatment assay revealed that FvePhyB is a bona fide red/far-red light photoreceptor,as it specifically inhibits hypocotyl length under red light.Transcriptome analysis showed that the FvePhyB mutation affects the expression levels of genes involved in hormone synthesis and signaling and anthocyanin biosynthesis in petioles and fruits.The srl mutant with a longer internode is caused by a mutation in the DELLA gene FveRGA1(Repressor of GA1)in the gibberellin pathway.We found that the P8 srl double mutant has much longer internodes than srl,suggesting a synergistic role of FvePhyB and FveRGA1 in this process.Taken together,these results demonstrate the important role of FvePhyB in regulating plant architecture and anthocyanin content in woodland strawberry.

Low temperature-mediated repression and far-red light-mediated induction determine morning FLOWERING LOCUS T expression levels

In order to flower in the appropriate season,plants monitor light and temperature changes and alter downstream pathways that regulate florigen genes such as Arabidopsis(Arabidopsis thaliana)FLOWERING LOCUS T(FT).In Arabidopsis,FT messenger RNA levels peak in the morning and evening under natural long-day conditions(LDs).However,the regulatory mechanisms governing morning FT induction remain poorly understood.The morning FT peak is absent in typical laboratory LDs characterized by high red:far-red light(R:FR)ratios and constant temperatures.Here,we demonstrate that ZEITLUPE(ZTL)interacts with the FT repressors TARGET OF EATs(TOEs),thereby repressing morning FT expression in natural environments.Under LDs with simulated sunlight(R:FR=1.0)and daily temperature cycles,which are natural LD-mimicking environmental conditions,FT transcript levels in the ztl mutant were high specifically in the morning,a pattern that was mirrored in the toe1 toe2 double mutant.Low night-to-morning temperatures increased the inhibitory effect of ZTL on morning FT expression by increasing ZTL protein levels early in the morning.Far-red light counteracted ZTL activity by decreasing its abundance(possibly via phytochrome A(phyA))while increasing GIGANTEA(GI)levels and negatively affecting the formation of the ZTL-GI complex in the morning.Therefore,the phyA-mediated high-irradiance response and GI play pivotal roles in morning FT induction.Our findings suggest that the delicate balance between low temperature-mediated ZTL activity and the far-red light-mediated functions of phyA and GI offers plants flexibility in fine-tuning their flowering time by controlling FT expression in the morning.

Stress responsive gene CIPK14 is involved in phytochrome A-mediated far-red light inhibition of greening in Arabidopsis

In this study, we show that CIPK14,a stress responsive CBL-interacting protein kinase gene,is involved in phytochrome A-mediated far-red light inhibition of greening in Arabidopsis seedlings. The CIPK14-impairment mutant cipk14 grown in continuous far-red (FR) light did not show greening when exposed to white light illumination for 15 h. By contrast, the FR-grown phytochrome A null mutant phyA greened within 0.5 h of exposure to white light. Although greening of Col-4 (wild-type) was not completely abolished by FR, it exhibited a significantly decreased greening capacity compared with that of phyA. Further analyses demonstrated that the expression of protochlorophyllide reductase (POR) genes was correlated with the greening ability of the genotypes. In addition, CIPK14 appeared to be regulated by both the circadian clock and PhyA. Taken together, these results suggest that CIPK14 plays a role in PhyA-mediated FR inhibition of seedling greening, and that a Ca-related kinase may be involved in a previously undefined branch point in the phytochrome A signaling pathway.

人LIGHT和HSV-TK-EGFP基因共转染的MSCs抗肿瘤免疫的体内研究

目的研究与单纯疱疹病毒的糖蛋白D竞争结合单纯疱疹病毒进入介导物(herpes virus entry mediator,HVEM)的淋巴毒素类似物(homologous to lymphotoxins,exhibits inducible expression,and competes with HSV glycoprotein D for HVEM,a receptor expressed by T lymphocytes,LIGHT)基因和单纯疱疹病毒胸苷激酶(herpes simplex virus thymidine kinase,HSV-TK)基因共转染的骨髓间充质干细胞(mesenchymal stem cells,MSCs)在体内的抗肿瘤免疫功能。方法将pIRES2-LIGHT基因和HSV-TK-EGFP基因共转染小鼠骨髓间充质干细胞(MSCs/LT组),以转染空载体和转染HSV-TK-EGFP基因的骨髓间充质干细胞作对照。流式细胞仪检测LIGHT分子和HSV-TK-EGFP分子在稳定转染的骨髓间充质干细胞上的表达。体内迁移实验观察MSCs/LT在小鼠体内迁移情况。观察更昔洛韦注射前后MSCs/LT对荷瘤小鼠体内肿瘤的治疗作用。ELISA法检测小鼠肿瘤组织中IFN-γ,IL-2和IL-10的水平。结果流式细胞仪检测发现,MSCs/LT能稳定高表达LIGHT分子。MSCs/LT有特异地向肿瘤组织趋化的特性。MSCs/LT和MSCs/T有较好的抑制肿瘤生长的能力,但在更昔洛韦诱导后,MSCs/LT的抗肿瘤效应下降甚至消失。同时,MSCs/LT可促使T细胞进入肿瘤组织,并促进T细胞分泌IL-2、IFN-γ,抑制IL-10分泌(P<0.05)。结论共转染人LIGHT和HSV-TK-EGFP基因的骨髓间充质干细胞能稳定高表达LIGHT分子,能特异性地向荷瘤小鼠体内肿瘤组织趋化并抑制肿瘤的生长,这种体内抗肿瘤功能可能与促进T淋巴细胞IL-2、IFN-γ等细胞因子的分泌,改善局部免疫抑制环境有关。

Novel Cr^(3+)-activated far-red emitting phosphors withβ-Ca_(3)(PO_(4))_(2)-type structure for indoor plant cultivation

Cr^(3+)-activated far-red and near-infrared phosphors have drawn considerable attention owing to their adjustable emission wavelengths and wide applications.Herein,we reported a series of Cr^(3+)-doped phosphors withβ-Ca_(3)(PO_(4))_(2)-type structure,of which Ca_(9)Ga(PO_(4))_(7):Cr^(3+) possessed the highest far-red emission intensity.At an excitation of 440 nm,the Ca_(9)Ga(PO_(4))_(7):Cr^(3+) phosphors exhibited a broad emission band ranging from 650 to 850 nm and peaking at 735 nm,and the broadband superimposed two sharp lines centering at 690 and 698 nm.The optimal sample Ca_(9)Ga_(0.97)(PO_(4))_(7):0.03 Cr^(3+) had an internal quantum efficiency of 55.7%.The luminescence intensity of the Ca_(9)Ga_(0.97)(PO_(4))_(7):0.03 Cr^(3+) phosphor obtained at 423 K could maintain 68.5%of that at room temperature,demonstrating its outstanding luminescence thermal stability.A phosphor-conversion light-emitting diode was fabricated,indicating that the Ca_(9)Ga(PO_(4))_(7):Cr^(3+) phosphor has potential applications in indoor plant cultivation.

雷公藤多苷片对IgA肾病大鼠LIGHT-HVEM/LTβR通路的影响

目的 基于炎症相关通路探讨雷公藤多苷片对IgA肾病大鼠肾脏的作用机制。方法 雄性SPF级SD大鼠,随机分为空白组、造模组。造模组采用联合“牛血清白蛋白+四氯化碳+脂多糖”建立IgA肾病大鼠模型。造模成功的大鼠随机分为模型组、泼尼松组、雷公藤多苷片组,于第13周开始治疗组灌胃给药,给药4周后留取大鼠24 h尿液、血液、肾组织并检测尿红细胞数、24 h-UTP、BUN、Scr;ELISA检测血清IL-1β、TNF-α水平;HE染色观察各组大鼠肾组织病理学变化;Western blot及RT-PCR检测大鼠肾组织LIGHT、HVEM、LTβR蛋白及其mRNA的表达。结果 雷公藤多苷片明显降低IgA肾病大鼠尿红细胞数、24 h-UTP、BUN、Scr水平,改善肾组织病理,降低血清炎症因子IL-1β、TNF-α水平,降低肾组织中LIGHT、HVEM、LTβR蛋白及其mRNA表达水平。结论 雷公藤多苷片可能通过下调LIGHT-HVEM/LTβR信号通路,抑制免疫反应,减少炎症因子释放,从而减轻炎症反应,降低尿红细胞及尿蛋白,改善肾脏病理损伤,保护肾功能。

基于改进GWO-LightGBM的磨煤机故障预警方法研究

为提高燃煤电厂磨煤机运维效率、降低运维成本,对磨煤机故障预警进行了研究。创新性地提出一种基于改进灰狼优化(GWO)算法的轻量级梯度提升机(LightGBM)故障预警方法。通过建立LightGBM轴承温度预测模型获取磨煤机轴承温度阈值,并引入改进GWO算法优化模型超参数,以提高算法效率和性能。试验结果表明,改进GWO-LightGBM算法相比支持向量机(SVM)等传统算法具有更高的精度和更优的泛化能力。通过实际故障案例证明,该方法能够提前2 h对磨煤机进行早期故障预警。该方法对燃煤电厂磨煤机安全运维具有指导意义。

基于CEEMDAN-VMD-TCN-lightGBM模型的水质预测研究

针对目前水质预测模型中因为数据本身的复杂性、在信号处理过程中存在的噪声干扰以及分解深度不够导致单一分解难以全面捕捉信号非线性特征的问题,提出了一种基于二次分解的水质预测模型。该模型采用完全自适应噪声集合经验模态分解(CEEMDAN)对原始数据进行分解,再利用变分模态分解(VMD)对熵值最高的模态分量进行二次分解,最终将处理后的时间序列输入到TCN-lightGBM多特征预测模型中。同时,采用麻雀算法(SSA)对预测模型进行优化。以山东省玉符河水质为例,本模型的均方根误差(RMSE)是0.1053,平均绝对误差(MAE)是0.0815,决定系数(R2)是0.9471,与GRU、LSTM、LightGBM、TCN等当下较为流行的模型的预测指标进行比较。结果显示,在R2上本模型提升了53.04%、70.41%、66.07%、65.20%等,在RMSE上减少了62.76%、65.50%、64.93%、64.80%等,在MAE上降低了62.76%、66.24%、63.80%、65.24%等。由此可知,基于CEEMDAN-VMD-TCN-lightGBM的模型具有更好的预测性能、泛化能力和捕捉信号非线性特征的能力。

Public health importance of light intensity physical activity

1.Light intensity physical activity(PA)benefits health PA guidelines worldwide recommend that adults accumulate 150 min of moderate intensity or 75 min of vigorous intensity PA(moderate-to-vigorous PA(MVPA))weekly to achieve health benefits.1-3 Absent from these guidelines are recommendations for light intensity PA(LPA,e.g.,walking at a leisurely pace of 3 km/h or less,equivalent to 1.5-2.9 metabolic equivalents).

Effects of thinning on the understory light environment of different stands and the photosynthetic performance and growth of the reforestation species Phoebe bournei

Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in south China(a Cryptomeria japonica plantation,a Quercus acutissima plantation,and a mixed stand of both)and three thinning intensities to determine the best understory light environ-ment for 3-year-old Phoebe bournei seedlings.The canopy structure,understory light environment,and photosynthe-sis and growth indicators were assessed following thin-ning.Thinning improved canopy structure and understory light availability of each stand;species composition was the reason for differences in the understory light environ-ment.Under the same thinning intensity,the mixed stand had the greatest light radiation and most balanced spectral composition.P.bournei photosynthesis and growth were closely related to the light environment;all three stands required heavy thinning to create an effective and sustained understory light environment.In a suitable understory light environment,the efficiency of light interception,absorption,and use by seedlings was enhanced,resulting in a higher carbon assimilation the main limiting factor was stomatal conductance.As a shade-avoidance signal,red/far-red radia-tion is a critical factor driving changes in photosynthesis and growth of P.bournei seedlings,and a reduction increased light absorption and use capacity and height:diameter ratios.The growth advantage transformed from diameter to height,enabling seedlings to access more light.Our findings suggest that the regeneration of shade-tolerant species such as P.bournei could be enhanced if a targeted approach to thinning based on stand type was adopted.

Generation of structured light beams with polarization variation along arbitrary spatial trajectories using tri-layer metasurfaces

Conventionally,the spatially structured light beams produced by metasurfaces primarily highlight the polarization modulation of the beams propagating along the optical axis or the beams'spatial transmission trajectory.In particular,along the optical axis,the polarization state is either constant or varies continuously in each output plane.Here,we develop innovative spatially structured light beams with continually changing polarization along any arbitrary spatial transmission trajectories.With tri-layer metallic metasurfaces,the geometric characteristics of each layer structure can be adjusted to modulate the phase and polarization state of the incident terahertz(THz)wave.The beam will converge to the predefined trajectory along several paths to generate a Bessel-like beam with longitudinal polarization changes.We demonstrate the versatility of the approach by designing two THz-band structured light beams with varying polarization states along the spatial helical transmission trajectory.Continuous linear polarization changes and linear polarization to right circular polarization(RCP)and back to linear polarization changes are realized respectively.The experimental results are basically consistent with the simulated results.Our proposal for arbitrary trajectory structured light beams with longitudinally varying polarization offers a practical method for continuously regulating the characteristics of spatial structured light beams with non-axial transmission.This technique has potential uses in optical encryption,particle manipulation,and biomedical imaging.

Model prediction of inactivation of Aeromonas salmonicida grown on poultry in situ by intense pulsed light

The aim of this study was to evaluate the factors influencing the inactivation effect of intense pulsed light(IPL)on Aeromonas salmonicida grown on chicken meat and skin,and to further develop prediction models of inactivation.In this work,chicken meat and skin inoculated with meat-borne A.salmonicida isolates were subjected to IPL treatments under different conditions.The results showed that IPL had obvious bactericidal effect in the chicken skin and thickness groups when the treatment voltage and time were 7 V combined with 5 s.In addition,the lethality curves of A.salmonicida were fitted under IPL conditions of 3.5-7.5 V.The comparison of statistical parameters revealed that the Weibull model could best fit the mortality curves and could accurately predict the mortality dynamic of A.salmonicida grown on chicken skin.And further a secondary model between the scale factor b and the treatment voltage in Weibull model was established using linear equations,which determined that the secondary model could accurately predict the inactivation of A.salmonicida.This study provides a theoretical basis for future prediction models of Aeromonas,and also provides new ideas for sterilization approaches of meat-borne Aeromonas.

基于LightGBM的智能可穿戴设备用户行为预测

智能可穿戴设备产生的大量数据是人类宝贵的数字资源。使用开放数据集和主流数据分析工具,如可进行快速模型开发的PyCaret模块,有助于人们进行数据挖掘工作,且不被细节所困扰。作为Kaggle竞赛爱好者的常用工具,LightGBM分类器对用户行为的预测表现优异,对此文中的研究结果也得到验证。

CAEFusion: A New Convolutional Autoencoder-Based Infrared and Visible Light Image Fusion Algorithm

To address the issues of incomplete information,blurred details,loss of details,and insufficient contrast in infrared and visible image fusion,an image fusion algorithm based on a convolutional autoencoder is proposed.The region attention module is meant to extract the background feature map based on the distinct properties of the background feature map and the detail feature map.A multi-scale convolution attention module is suggested to enhance the communication of feature information.At the same time,the feature transformation module is introduced to learn more robust feature representations,aiming to preserve the integrity of image information.This study uses three available datasets from TNO,FLIR,and NIR to perform thorough quantitative and qualitative trials with five additional algorithms.The methods are assessed based on four indicators:information entropy(EN),standard deviation(SD),spatial frequency(SF),and average gradient(AG).Object detection experiments were done on the M3FD dataset to further verify the algorithm’s performance in comparison with five other algorithms.The algorithm’s accuracy was evaluated using the mean average precision at a threshold of 0.5(mAP@0.5)index.Comprehensive experimental findings show that CAEFusion performs well in subjective visual and objective evaluation criteria and has promising potential in downstream object detection tasks.

Electrically-driven ultrafast out-of-equilibrium light emission from hot electrons in suspended graphene/hBN heterostructures

Nanoscale light sources with high speed of electrical modulation and low energy consumption are key components for nanophotonics and optoelectronics.The record-high carrier mobility and ultrafast carrier dynamics of graphene make it promising as an atomically thin light emitter which can be further integrated into arbitrary platforms by van der Waals forces.However,due to the zero bandgap,graphene is difficult to emit light through the interband recombination of carriers like conventional semiconductors.Here,we demonstrate ultrafast thermal light emitters based on suspended graphene/hexagonal boron nitride(Gr/hBN)heterostructures.Electrons in biased graphene are significantly heated up to 2800 K at modest electric fields,emitting bright photons from the near-infrared to the visible spectral range.By eliminating the heat dissipation channel of the substrate,the radiation efficiency of the suspended Gr/hBN device is about two orders of magnitude greater than that of graphene devices supported on SiO2or hBN.Wefurther demonstrate that hot electrons and low-energy acoustic phonons in graphene are weakly coupled to each other and are not in full thermal equilibrium.Direct cooling ofhigh-temperature hot electrons to low-temperature acoustic phonons is enabled by the significant near-field heat transfer at the highly localized Gr/hBN interface,resulting in ultrafast thermal emission with up to 1 GHz bandwidth under electrical excitation.It is found thatsuspending the Gr/hBN heterostructures on the SiO2trenches significantly modifies the light emission due to the formation of the optical cavity and showed a~440%enhancement inintensity at the peak wavelength of 940 nm compared to the black-body thermal radiation.The demonstration of electrically driven ultrafast light emission from suspended Gr/hBNheterostructures sheds the light on applications of graphene heterostructures in photonicintegrated circuits,such as broadband light sources and ultrafast thermo-optic phase modulators.

Miscibility of light oil and flue gas under thermal action

The miscibility of flue gas and different types of light oils is investigated through slender-tube miscible displacement experiment at high temperature and high pressure.Under the conditions of high temperature and high pressure,the miscible displacement of flue gas and light oil is possible.At the same temperature,there is a linear relationship between oil displacement efficiency and pressure.At the same pressure,the oil displacement efficiency increases gently and then rapidly to more than 90% to achieve miscible displacement with the increase of temperature.The rapid increase of oil displacement efficiency is closely related to the process that the light components of oil transit in phase state due to distillation with the rise of temperature.Moreover,at the same pressure,the lighter the oil,the lower the minimum miscibility temperature between flue gas and oil,which allows easier miscibility and ultimately better performance of thermal miscible flooding by air injection.The miscibility between flue gas and light oil at high temperature and high pressure is more typically characterized by phase transition at high temperature in supercritical state,and it is different from the contact extraction miscibility of CO_(2) under conventional high pressure conditions.

An Investigation of Lighting Levels and Sleep Quality

Sleep quality in young adults is compromised. Instead of the recommended 7 hours, young adults’ schedule interruptions disturb sleep to a typical six and a half hours, with common disturbances in falling asleep and staying asleep. Recent literature has identified an association between academic performance, negative mood state and low activity level in young adults with sleep disturbances. Young adulthood is a time for the installation of sleep health. Both individual and schedule impositions to the young adults’ sleep schedule are to be modified to obtain Sleep Health. Recent research has identified daytime light effects on sleep such as blue light from electronics as alerting and low level light for relaxation. The aim of this study was to identify sleep quality effects with varying light exposures. It was hypothesized that bright (>450 lux) light conditions would be considered focusing and low light (<220 lux) would be considered calming. We hypothesized that sleep quality would improve by 5% with the introduction of a calm light condition. Undergraduates from a small midwestern university were invited to participate in the study in exchange for a gift card. Six participants completed the study, two males, four females all between 21 - 24 years old. Both hypotheses were supported by qualitative analysis.