Frontogenesis and Frontolysis of a Cold Filament Driven by the Cross-Filament Wind and Wave Fields Simulated by a Large Eddy Simulation

The variations of the frontogenetic trend of a cold filament induced by the cross-filament wind and wave fields are studied by a non-hydrostatic large eddy simulation. Five cases with different strengths of wind and wave fields are studied.The results show that the intense wind and wave fields further break the symmetries of submesoscale flow fields and suppress the levels of filament frontogenesis. The changes of secondary circulation directions—that is, the conversion between the convergence and divergence of the surface cross-filament currents with the downwelling and upwelling jets in the filament center—are associated with the inertial oscillation. The filament frontogenesis and frontolysis caused by the changes of secondary circulation directions may periodically sharpen and smooth the gradient of submesoscale flow fields.The lifecycle of the cold filament may include multiple stages of filament frontogenesis and frontolysis.

High-Throughput physiology-based stress response phenotyping:Advantages,applications and prospective in horticultural plants

Phenomics is a new branch of science that provides high-throughput quantification of plant and animal traits at systems level.The last decade has witnessed great successes in high-throughput phenotyping of numerous morphological traits,yet major challenges still exist in precise phenotyping of physiological traits such as transpiration and photosynthesis.Due to the highly dynamic nature of physiological traits in responses to the environment,appropriate selection criteria and efficient screening systems at the physiological level for abiotic stress tolerance have been largely absent in plants.In this review,the current status of phenomics techniques was briefly summarized in horticultural plants.Specifically,the emerging field of high-throughput physiology-based phenotyping,which is referred to as“physiolomics”,for drought stress responseswas highlighted.In addition to analyzing the advantages of physiology-based phenotyping overmorphology-based approaches,recent examples that applied high-throughput physiological phenotyping to model and non-model horticultural plants were revisited and discussed.Based on the collective findings,we propose that high-throughput,non-destructive,and automatic physiological assays can and should be used as routine methods for phenotyping stress response traits in horticultural plants.

A universal pipeline for mobile mRNA detection and insights into heterografting advantages under chilling stress

Heterografting has long been used to enhance the chilling tolerance of temperature-sensitive crops,including watermelon,whose mechanism is known to involve bidirectional long-distance mRNA movements.Despite several studies reporting on mobile mRNA(mb-mRNA)profiles in plants,accurate identification of mb-mRNAs is challenging owing to an array of technical problems.Here,we developed a bioinformatical pipeline that took most of the known technical concerns into consideration and is considered to be a universal tool for mb-mRNA detection in heterografts.By applying this pipeline to a commercial watermelon–bottle gourd heterografting system,we detected 130 and 1144 mb-mRNAs upwardly and 167 and 1051 mb-mRNAs downwardly transmitted under normal and chilling-stress conditions,respectively.Quantitative real-time PCR indicated a high accuracy rate(88.2%)of mb-mRNA prediction with our pipeline.We further revealed that the mobility of mRNAs was not associated with their abundance.Functional annotation and classification implied that scions may convey the stress signal to the rootstock,subsequently triggering energy metabolism reprogramming and abscisic acid-mediated stress responses by upward movement of effective mRNAs,ultimately leading to enhanced chilling tolerance.This study provides a universal tool for mb-mRNA detection in plant heterografting systems and novel insights into heterografting advantages under chilling stress.

Influence of Coriolis Parameter Variation on Langmuir Turbulence in the Ocean Upper Mixed Layer with Large Eddy Simulation

Langmuir turbulence is a complex turbulent process in the ocean upper mixed layer.The Coriolis parameter has an important effect on Langmuir turbulence through the Coriolis-Stokes force and Ekman effect,however,this effect on Langmuir turbulence has not been systematically investigated.Here,the impact of the Coriolis parameter on Langmuir turbulence with a change of latitude(LAT)from 20°N to 80°N is studied using a non-hydrostatic large eddy simulation model under an ideal condition.The results show that the ratio of the upper mixed layer depth to Ekman depth scale(RME)RME=0.266(LAT=50°N)is a key value(latitude)for the modulation effect of the Coriolis parameter on the mean and turbulent statistics of Langmuir turbulence.It is found that the rate of change of the sea surface temperature,upper mixed layer depth,entrainment flux,crosswind velocity,downwind vertical momentum flux,and turbulent kinetic energy budget terms associated with Langmuir turbulence are more evident at RME≤0.266(LAT≤50°N)than at RME≥0.266(LAT≥50°N).However,the rate of change of the depth-averaged crosswind vertical momentum flux does not have a clear variation between RME≤0.266 and RME≥0.266.The complex changes of both Langmuir turbulence characteristics and influence of Langmuir turbulence on the upper mixed layer with latitude presented here may provide more information for further improving Langmuir turbulence parameterization.

Correction to:A universal pipeline for mobile mRNA detection and insights into heterografting advantages under chilling stress

After the publication of this article1,the authors became aware that there was an error in Fig.2b that“Ref2-M”(below“Bowtie2”)on the right panel was mistakenly written as“Ref1-M”.The correct version is shown below.

Influence of the upper mixed layer depth on Langmuir turbulence characteristics

The upper mixed layer depth(h)has a significant seasonal variation in the real ocean and the low-order statistics of Langmuir turbulence are dramatically influenced by the upper mixed layer depth.To explore the influence of the upper mixed layer depth on Langmuir turbulence under the condition of the wind and wave equilibrium,the changes of Langmuir turbulence characteristics with the idealized variation of the upper mixed layer depth from very shallow(h=5 m)to deep enough(h=40 m)are studied using a non-hydrostatic large eddy simulation model.The simulation results show that there is a direct entrainment depth induced by Langmuir turbulence(h_(LT))within the thermocline.The normalized depthaveraged vertical velocity variance is smaller and larger than the downwind velocity variance for the ratio of the upper mixed layer to a direct entrainment depth induced by Langmuir turbulence h/h_(LT)<1 and h/h_(LT)>1,respectively,indicating that turbulence characteristics have the essential change(i.e.,depth-averaged vertical velocity variance(DAVV)DADV for Langmuir turbulence)between h/h_(LT)<1 and h/h_(LT)>1.The rate of change of the normalized depth-averaged low-order statistics for h/h_(LT)<1 is much larger than that for h/h_(LT)>1.The reason is that the downward pressure perturbation induced by Langmuir cells is strongly inhibited by the upward reactive force of the strong stratified thermocline for h/h_(LT)<1 and the eff ect of upward reactive force on the downward pressure perturbation becomes weak for h/h_(LT)>1.Hence,the upper mixed layer depth has significant influences on Langmuir turbulence characteristics.

A novel BODIPY-based nano-photosensitizer with aggregation-induced emission for cancer photodynamic therapy

The discovery of aggregation induced enmission(AIE)effect provides opportunities for the rapid development of fuorescence imaging-guided photodynamic therapy(PDT).In this work,a boron dipyrromethene(BODIPY)-based photosensitizer(ET-BDP-O)with AIE characteristics was developed,in which the two linear arms of BODIPY group were linked with triphenylamine to form an electron Donor-Acceptor-Donor(D-A-D)architecture while side chain was equipped with triethylene glycol group.ET-BDP-O was able to directly self-assemble into nanoparticles(NPs)without supplement of any other matrices or stabilizers due to its amphiphilic property.The as-prepared ET-BDP-O NPs had an excellent colloid stability with the size of 125 nm.Benefiting from the AIE property,ET-BDP-O NPs could generate strong fluorescence and reactive oxygen species under light-emitting diode light rradiation(60mW/cm^(2)).After inter-nalized in cancer cells,ET-BDP-O NPs were able to emit bright red fuorescence signal for bioimaging.In addition,the cell viability assay demonstrated that the ET-BDP-O NPs exhibited excellent photocytotoxicity against cancer cells,while negligible cytotoicity under dark envi-ronment.Thus,ET-BDP-O NPs might be regarded as a promising photosensitizer for fluores-cence imaging-guided PDT in future.

MtROP8 is involved in root hair development and the establishment of symbiotic interaction between Medicago truncatula and Sinorhizobium meliloti

Emerging evidence has demonstrated that ROP GTPases play important roles in symbiosis,but the molecular mechanisms on their regulation in symbiosis are largely unknown.In this study,we showed that MtROP8 is involved in the symbiotic interaction between Medicago truncatula and Sinorhizobium meliloti.Expression analyses showed that MtROP8 was down-regulated in the early infected roots,but significantly up-regulated in nodules compared to the roots.Phenotypic analysis of RNA interference(RNAi)-mediated silencing of MtROP8 revealed that knock-down of MtROP8 expression resulted in various developmental defects of root hairs,including branched hairs,short bulbous root hairs,and even root hairs with apparent swollen bases,which were caused by the modification of the distribution and the levels of reactive oxygen species(ROS).Moreover,infection events were increased in transgenic roots harboring the MtROP8 RNAi construct in response to S.meliloti inoculation,concomitant with enhanced nodulation.These results indicate that MtROP8participates in root hair development and the establishmentof the symbiotic interaction by regulating ROS production and distribution.

Impact of anthropogenic heat emissions on meteorological parameters and air quality in Beijing using a high-resolution model simulation

Anthropogenic heat emissions(AHE)play an important role in modulating the atmospheric thermodynamic and kinetic properties within the urban planetary boundary layer,particularly in densely populated megacities like Beijing.In this study,we estimate the AHE by using a Large-scale Urban Consumption of energY(LUCY)model and further couple LUCY with a high-resolution regional chemical transport model to evaluate the impact of AHE on atmospheric environment in Beijing.In areas with high AHE,the 2-m temperature(T_(2))increased to varying degrees and showed distinct diurnal and seasonal variations with maxima in night and winter.The increase in 10-m wind speed(WS_(10))and planetary boundary layer height(PBLH)exhibited slight diurnal variations but showed significant seasonal variations.Further,the systematic continuous precipitation increased by 2.1 mm due to the increase in PBLH and water vapor in upper air.In contrast,the precipitation in local thermal convective showers increased little because of the limited water vapor.Meanwhile,the PM_(2.5) reduced in areas with high AHE because of the increase in WS_(10) and PBLH and continued to reduce as the pollution levels increased.In contrast,in areas where prevailing wind direction was opposite to that of thermal circulation caused by AHE,the WS_(10) reduced,leading to increased PM_(2.5).The changes of PM_(2.5) illustrated that a reasonable AHE scheme might be an effective means to improve the performance of PM_(2.5) simulation.Besides,high AHE aggravated the O_(3) pollution in urban areas due to the reduction in NO_(x).