The leaves of plants are colonized by various microorganisms. In comparison to the rhizosphere, less is known about the characteristics and ecological functions of phyllosphere microorganisms. ...Phyllosphere microorganisms mainly originate from soil, air, and seeds. The composition of phyllosphere microorganisms is mainly affected by ecological and abiotic factors. Phyllosphere microorganisms execute multiple ecological functions by influencing leaf functions and longevity, seed mass, fruit development, and homeostasis of host growth. A plant can respond to phyllosphere microorganisms by secondary metabolite secretion and its immune system. Meanwhile, phyllosphere microorganisms play an important role in ecological stability and environmental safety assessment. However, as a result of the instability of the phyllosphere environment and the poor cultivability of phyllosphere microorganisms in the current research, there are still many limitations, such as the lack of insight into the mechanisms of plant–microorganism interactions, the roles of phyllosphere microorganisms in plant growth processes, the responses of phyllosphere microorganisms to plant metabolites, etc. This review summarizes the latest progress made in the research of the phyllosphere in recent years. This is beneficial for deepening our understanding of phyllosphere microorganisms and promoting the research of plant–atmosphere interactions, plant pathogens, and plant biological control.
Non-steroidal, anti-inflammatory drugs (NSAIDs) are widely used pharmaceutical products with analgesic and anti-inflammatory effects that are consistently detected in municipal wastewater systems and ...in municipal biosolids. Land application of biosolids and irrigation with reclaimed wastewater introduces these compounds into agricultural environments, which is an emerging issue of concern for ecosystem health. In this study, the sorption-desorption behaviour of four commonly consumed NSAIDs, including naproxen (NPX), ibuprofen (IBU), ketoprofen (KTF), and diclofenac (DCF), was examined in a loam textured soil exposed to either an individual-compound or a mixture of the four NSAIDs. The proportion of NSAIDs adsorbed to the soil in the mixture-compound system was 72%, 55%, 50% and 45%, for diclofenac, naproxen, ketoprofen, and ibuprofen, respectively, and differed slightly from the individual compound adsorption. Diclofenac displayed strong sorption and low desorption in both the individual-compound and mixture-compound systems. Naproxen and ibuprofen exhibited significant differences between the adsorption isotherms of the individual-compound and mixture-compound systems. Results of this study highlight differences in the sorption behaviour of NSAIDs, when present as mixtures, possibly through multilayer bonding effects or complexation with cationic metals or organo-clays from the soil. Soil organic matter (SOM) may have played a role in determining some of the interactions between the compounds but other factors associated with the mixture-compound system, such as cation bridging or multilayer cooperative adsorption. Desorption data suggests that the mechanisms involved in binding NSAIDs to the soil surface are also influence by the presence of other compounds in a mixture. A reduction in desorption was observed for all four NSAIDs in the mixture-compound system relative to the individual-compound system, but were greatest for naproxen and ibuprofen. The sorption-desorption hysteresis increased for naproxen and ibuprofen in the mixture-compound system. This study suggests that cooperative adsorption plays a role in the interaction of NSAIDs when present as mixtures rather than as individual compounds.
•A loam textured soil was exposed to four non-steroidal anti-inflammatory drugs in a mixture.•Sorption affinity to the soil followed the order: diclofenac > naproxen > ketoprofen > ibuprofen.•The four NSAIDs desorbed from the soil in the order: diclofenac > naproxen > ketoprofen > ibuprofen.•Results suggest that cooperative sorption-desorption of NSAIDs when present in mixtures.
The understanding of oxidation in forest atmospheres is being challenged by measurements of unexpectedly large amounts of hydroxyl (OH). A significant number of these OH measurements were made by ...laser-induced fluorescence in low-pressure detection chambers (called Fluorescence Assay with Gas Expansion (FAGE)) using the Penn State Ground-based Tropospheric Hydrogen Oxides Sensor (GTHOS). We deployed a new chemical removal method to measure OH in parallel with the traditional FAGE method in a California forest. The new method gives on average only 40-60% of the OH from the traditional method and this discrepancy is temperature dependent. Evidence indicates that the new method measures atmospheric OH while the traditional method is affected by internally generated OH, possibly from oxidation of biogenic volatile organic compounds. The improved agreement between OH measured by this new technique and modeled OH suggests that oxidation chemistry in at least one forest atmosphere is better understood than previously thought.
For deep excavations in residual soils that are underlain by highly fissured or fractured rocks, it is common to observe the drawdown of the groundwater table behind the excavation, resulting in ...seepage-induced ground settlement. In this study, finite element analyses are firstly performed to assess the critical parameters that influence the ground settlement performance in residual soil deposits subjected to groundwater drawdown. The critical parameters that influence the ground settlement performance were identified as the excavation width, the excavation depth, the depth of groundwater drawdown, the thickness of the residual soil, the average SPT
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value of the residual soil, the location of the moderately weathered rock, and the wall system stiffness. Subsequently, an artificial neural network (ANN) model was developed to provide estimates of the maximum ground settlement. Validation of the performance of ANN model was carried out using additional data derived from finite element analyses as well as with measured data from a number of excavation sites.
In this Letter we try to search for signals generated by ultraheavy dark matter at the Large High Altitude Air Shower Observatory (LHAASO) data. We look for possible γ rays by dark matter ...annihilation or decay from 16 dwarf spheroidal galaxies in the field of view of the LHAASO. Dwarf spheroidal galaxies are among the most promising targets for indirect detection of dark matter that have low fluxes of astrophysical γ-ray background while having large amount of dark matter. By analyzing more than 700 days of observational data at LHAASO, no significant dark matter signal from 1 TeV to 1 EeV is detected. Accordingly we derive the most stringent constraints on the ultraheavy dark matter annihilation cross section up to EeV. The constraints on the lifetime of dark matter in decay mode are also derived.In this Letter we try to search for signals generated by ultraheavy dark matter at the Large High Altitude Air Shower Observatory (LHAASO) data. We look for possible γ rays by dark matter annihilation or decay from 16 dwarf spheroidal galaxies in the field of view of the LHAASO. Dwarf spheroidal galaxies are among the most promising targets for indirect detection of dark matter that have low fluxes of astrophysical γ-ray background while having large amount of dark matter. By analyzing more than 700 days of observational data at LHAASO, no significant dark matter signal from 1 TeV to 1 EeV is detected. Accordingly we derive the most stringent constraints on the ultraheavy dark matter annihilation cross section up to EeV. The constraints on the lifetime of dark matter in decay mode are also derived.
To understand how genomic heterogeneity of glioblastoma (GBM) contributes to poor therapy response, we performed DNA and RNA sequencing on GBM samples and the neurospheres and orthotopic xenograft ...models derived from them. We used the resulting dataset to show that somatic driver alterations including single-nucleotide variants, focal DNA alterations and oncogene amplification on extrachromosomal DNA (ecDNA) elements were in majority propagated from tumor to model systems. In several instances, ecDNAs and chromosomal alterations demonstrated divergent inheritance patterns and clonal selection dynamics during cell culture and xenografting. We infer that ecDNA was unevenly inherited by offspring cells, a characteristic that affects the oncogenic potential of cells with more or fewer ecDNAs. Longitudinal patient tumor profiling found that oncogenic ecDNAs are frequently retained throughout the course of disease. Our analysis shows that extrachromosomal elements allow rapid increase of genomic heterogeneity during GBM evolution, independently of chromosomal DNA alterations.
Osteosarcoma (OS) is the most common primary malignancy of bone. There is a critical need to identify the events that lead to the poorly understood mechanism of OS development and metastasis. The ...goal of this investigation is to identify and characterize a novel marker of OS progression. We have established and characterized a highly metastatic OS subline that is derived from the less metastatic human MG63 line through serial passages in nude mice via intratibial injections. Microarray analysis of the parental MG63, the highly metastatic MG63.2 subline, as well as the corresponding primary tumors and pulmonary metastases revealed insulin-like growth factor binding protein 5 (IGFBP5) to be one of the significantly downregulated genes in the metastatic subline. Confirmatory quantitative RT-PCR on 20 genes of interest demonstrated IGFBP5 to be the most differentially expressed and was therefore chosen to be one of the genes for further investigation. Adenoviral mediated overexpression and knockdown of IGFBP5 in the MG63 and MG63.2 cell lines, as well as other OS lines (143B and MNNG/HOS) that are independent of our MG63 lines, were employed to examine the role of IGFBP5. We found that overexpression of IGFBP5 inhibited in vitro cell proliferation, migration and invasion of OS cells. Additionally, IGFBP5 overexpression promoted apoptosis and cell cycle arrest in the G1 phase. In an orthotopic xenograft animal model, overexpression of IGFBP5 inhibited OS tumor growth and pulmonary metastases. Conversely, siRNA-mediated knockdown of IGFBP5 promoted OS tumor growth and pulmonary metastases in vivo. Immunohistochemical staining of patient-matched primary and metastatic OS samples demonstrated decreased IGFBP5 expression in the metastases. These results suggest 1) a role for IGFBP5 as a novel marker that has an important role in the pathogenesis of OS, and 2) that the loss of IGFBP5 function may contribute to more metastatic phenotypes in OS.
Soil liquefaction during earthquakes can result in ground movements that cause damage to buildings and lifelines. Lateral spreading is one form of earthquake-induced ground movements that have caused ...extensive damage in previous earthquakes. The lateral displacement is dependent on many factors including the earthquake magnitude, thickness and particle size of the liquefiable subsoils and the depth of the groundwater. A number of analytical and empirical methods have been proposed to predict the magnitude of the lateral displacement. One common empirical method is the MLR model which is based on multiple linear regression (MLR) analysis of a database of observed case histories. It is proposed in this paper to use a nonparametric regression procedure known as multivariate adaptive regression splines (MARS), as an improvement to the current MLR model to predict the liquefaction induced lateral displacement. First the basis of the MARS method and its associated procedures are explained in detail. Results are then presented to show the accuracy of the proposed approach, in comparison to the commonly used multiple regression approach. Analysis of observed case histories indicated that the MARS outperforms MLR in terms of predictive accuracy. MARS automatically models non-linearities and interactions between variables without making any specific assumptions. Furthermore, it is able to provide the relative importance of the input variables and give insights of where significant changes in the data may occur.
•Liquefaction-induced lateral spread database was analyzed.•A method called multivariate adaptive regression splines (MARS) was used.•MARS was found to perform better than multiple linear regression.•MARS was found to be computationally efficient.
We present a multi‐objective, multi‐stage stochastic programming with recourse model for reservoir management and operation, where we use utility theory to select the best compromise solution from ...the Pareto front. A multi‐stage streamflow scenario tree is generated first by the neural gas method. Then the Pareto front at each stage is produced by a modified constrained NSGA‐II. A single best compromise solution on the Pareto front must be selected for the immediate stage and the model moves forward one stage and is re‐optimized over a moving planning horizon of fixed duration. A key contribution of this study is the selection of the best compromise solution, which is achieved by a proposed linear spline utility function allied with regression. Our proposed utility function has the following advantages: (a) It satisfies the law of diminishing marginal rate of substitution, (b) it does not rely on the pre‐specified weight or goal, and (c) it selects the best compromise solution that is likely to fall in the “knee regions” of the Pareto front. We apply the proposed optimization model to the Three Gorges Reservoir in China. The two conflicting objectives are (a) maximizing the total expected energy output in the planning horizon, and (b) maximizing the average expected ecological benefits in the planning horizon. The results show that the proposed model produces the optimal water release policy successfully under different hydrological scenarios, considering both the inflow uncertainty and the tradeoff between the two conflicting objectives.
Key Points
Presents a multi‐objective, multi‐stage stochastic programming with recourse model for reservoir operations
Develops a linear spline utility function for selecting the most preferred solution on the Pareto front
Evaluates the performance of the proposed optimization framework with a real‐world case study
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