Optical Force and Torque on a Graphene-Coated Gold Nanosphere by a Vector Bessel Beam

In the framework of the generalized Lorenz–Mie theory (GLMT), the optical force and torque on a graphene-coated gold nanosphere by a vector Bessel beam are investigated. The core of the particle is gold, whose dielectric function is given by the Drude–Sommerfeld model, and the coating is multilayer graphene with layer number N, whose dielectric function is described by the Lorentz–Drude model. The axial optical force [Formula: see text] and torque [Formula: see text] are numerically analyzed, and the effects of the layer number N, wavelength [Formula: see text] , and beam parameters (half-cone angle [Formula: see text] , polarization, and order l) are mainly discussed. Numerical results show that the optical force and torque peaks can be adjusted by increasing the thickness of the graphene coating, and can not be adjusted by changing [Formula: see text] and l. However, [Formula: see text] and l can change the magnitude of the optical force and torque. The numerical results have potential applications involving the trapped graphene-coated gold nanosphere

Soil organic carbon stock and carbon efflux in deep soils of desert and oasis

An experiment was carried out in two soils of oasis farmland and the surrounding desert at the southern periphery of the Gurbantonggut Desert, in central Asia, to test the effects of land use on soil organic carbon (SOC) stock and carbon efflux in deep soil. The result showed that although SOC content in the topsoil (0-0.2 m) decreased by 27% after desert soil was cultivated, total carbon stock within the soil profile (0-2.5 m) increased by 57% due to the significant increase in carbon stock at 0.2- to 2.5-m depth, and carbon efflux also markedly increased at 0- to 0.6-m depth. In the topsoil, the carbon process of the oasis was mainly dominated by consumption; in the subsoil (0.2-0.6 m) it was likely to be co-dominated by storage and consumption, and the greatest difference in SOC stock between the two soils also lay in this layer; while in the deep layer (0.6-2.5 m) of the oasis, with a more stable carbon stock, there was carbon storage dominated. Moreover, carbon stocks in the deep layer of the two soils contributed about 65% of the total carbon stocks, and correspondingly, microbial activities contributed 71% to the total microbial activity in the entire soil profile, confirming the importance of carbon cycling in the deep layer. Desert cultivation in this area may produce unexpectedly high carbon stocks from the whole profile despite carbon loss in the topsoil

Genome-wide identification of new reference genes for RT-qPCR normalization in CGMMV-infected Lagenaria siceraria

Lagenaria siceraria is an economically important cucurbitaceous crop, but suitable reference genes (RGs) to use when the plants are infected by cucumber green mottle mosaic virus (CGMMV) have not been determined. Sixteen candidate RGs of both leaf and fruit and 18 candidate RGs mostly from separate RNA-Seq datasets of bottle gourd leaf or fruit were screened and assessed by RT-qPCR. The expression stability of these genes was determined and ranked using geNorm, NormFinder, BestKeeper and RefFinder. Comprehensive analysis resulted in the selection of LsCYP, LsH3, and LsTBP as the optimal RGs for bottle gourd leaves, and LsP4H, LsADP, and LsTBP for fruits. LsWD, LsGAPDH, and LsH3 were optimal for use in both leaves and fruits under the infection of CGMMV. Isopentenyl transferase (IPT) and DNA-directed RNA polymerase (DdRP) were used to validate the applicability of the most stable identified RGs from bottle gourd in response to CGMMV. All the candidate RGs performed in RT-qPCR consistently with the data from the transcriptome database. The results demonstrated that LsWD, LsGAPDH and LsH3 were the most suitable internal RGs for the leaf, and LsH3, LsGAPDH, LsP4H and LsCYP for the fruit

CT-based radiomics for predicting radio-chemotherapy response and overall survival in nonsurgical esophageal carcinoma

BackgroundTo predict treatment response and 2 years overall survival (OS) of radio-chemotherapy in patients with esophageal cancer (EC) by radiomics based on the computed tomography (CT) images.MethodsThis study retrospectively collected 171 nonsurgical EC patients treated with radio-chemotherapy from Jan 2010 to Jan 2019. 80 patients were randomly divided into training (n=64) and validation (n=16) cohorts to predict the radiochemotherapy response. The models predicting treatment response were established by Lasso and logistic regression. A total of 156 patients were allocated into the training cohort (n=110), validation cohort (n=23) and test set (n=23) to predict 2-year OS. The Lasso Cox model and Cox proportional hazards model established the models predicting 2-year OS.ResultsTo predict the radiochemotherapy response, WFK as a radiomics feature, and clinical stages and clinical M stages (cM) as clinical features were selected to construct the clinical-radiomics model, achieving 0.78 and 0.75 AUC (area under the curve) in the training and validation sets, respectively. Furthermore, radiomics features called WFI and WGI combined with clinical features (smoking index, pathological types, cM) were the optimal predictors to predict 2-year OS. The AUC values of the clinical-radiomics model were 0.71 and 0.70 in the training set and validation set, respectively.ConclusionsThis study demonstrated that planning CT-based radiomics showed the predictability of the radiochemotherapy response and 2-year OS in nonsurgical esophageal carcinoma. The predictive results prior to treatment have the potential to assist physicians in choosing the optimal therapeutic strategy to prolong overall survival

A metabolomic- and transcriptomic-level investigation of ant brains infected with the lancet liver fluke Dicrocoelium dendriticum

Parasites often manipulate host phenotypes to facilitate their own transmission. Wood ants, Formica aserva, infected with larvae of the lancet liver fluke, Dicrocoelium dendriticum, leave their nests during the cool hours of the day to ascend and attached to a plant, where they remain overnight, and detach the next morning when temperatures rise returning to their nest. They repeat this bizarre attachment and detachment sequence for the rest of the summer. My thesis seeks to understand the molecular mechanisms that underlie this complex manipulation of host behaviour that is ‘on-then-off’ through metabolomics and transcriptomics approaches. I first characterized changes in the metabolite concentrations in ant brains collected from a site of D. dendriticum emergence in southern Alberta, Canada. Within the laboratory, I recreated the manipulation cycle to mimic pre-attached, attached, and post-attached stages, and sampled infected and uninfected ant brains from each stage. Mean brain concentration of neurotransmitters tyramine and serotonin were reduced in infected ants compared to uninfected during detachment phases by 22% and 17%, respectively. These reductions paralleled a 40% reduction in overall host activity in infected versus uninfected ants during the detachment phase. I then compared the gene expression pattern of brains from infected and uninfected ants at the same samples stages as above. I found that 13,556 genes were differentially expressed, including those involved in environmental sensing and the production of biogenic monoamines. I found genes involved in odorant and vision were downregulated in attached infected ants. Vision genes were upregulated in post-attached infected ants compared to uninfected controls. Genes involved in serotonin synthesis were also downregulated during the post-attached stages in infected ants. These results support that the regulation of biogenic monoamines in the brains of infected ants plays a role in this complex manipulation of host behaviour. Overall, this study helps us better understand how D. dendriticum manipulates their ant host behaviour. My findings show that the mechanisms driving reversible manipulations is more complex than the parasite-induced control of ‘on-then-off’ triggers. In the D. dendriticum-ant system, different mechanisms are involved at different stages of the manipulation

Soil microbial community shifts explain habitat heterogeneity in two Haloxylon species from a nutrient perspective

Haloxylon ammodendron and Haloxylon persicum (as sister taxa) are dominant shrubs in the Gurbantunggut Desert. The former grows in inter-dune lowlands while the latter in sand dunes. However, little information is available regarding the possible role of soil microorganisms in their habitat heterogeneity from a nutrient perspective in deserts. Rhizosphere is the interface of plant-microbe-soil interactions and fertile islands usually occur around the roots of desert shrubs. Given this, we applied quantitative real-time PCR combined with MiSeq amplicon sequencing to compare their rhizosphere effects on microbial abundance and community structures at three soil depths (0–20, 20–40, and 40–60 cm). The rhizosphere effects on microbial activity (respiration) and soil properties had also been estimated. The rhizospheres of both shrubs exerted significant positive effects on microbial activity and abundance (e.g. eukarya, bacteria and nitrogen-fixing microbes). The rhizosphere effect of H. ammodendron on microbial activity and abundance of bacteria and nitrogen-fixing microbes was greater than that of H. persicum. However, the fertile island effect of H. ammodendron was weaker than that of H. persicum. Moreover, there existed distinct differences in microbial community structure between the two rhizosphere soils. Soil-available nitrogen, especially nitrate nitrogen was shown to be a driver of microbial community differentiation among rhizosphere and non-rhizosphere soils in the desert. In general, the rhizosphere of H. ammodendron recruited more copiotrophs (e.g. Firmicutes, Bacteroidetes and Proteobacteria), nitrogen-fixing microbes and ammonia-oxidizing bacteria, and with stronger microbial activities. This helps it maintain a competitive advantage in relatively nutrient-rich lowlands. H. persicum relied more on fungi, actinomycetes, archaea (including ammonia-oxidizing archaea) and eukarya, with higher nutrient use efficiency, which help it adapt to the harsher dune crests. This study provides insights into the microbial mechanisms of habitat heterogeneity in two Haloxylon species in the poor desert soil.Funding provided by: Science & Technology Department of Xinjiang Uygur Autonomous RegionCrossref Funder Registry ID: http://dx.doi.org/10.13039/100016079Award Number: 2022E01011Funding provided by: National Natural Science Foundation of ChinaCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001809Award Number: 32171874Funding provided by: National Natural Science Foundation of ChinaCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001809Award Number: 42171068This study focuses on the rhizosphere soils (0–60 cm) of H. ammodendron and H. persicum and their corresponding soil environments in the Gurbantunggut Desert. Given that N is the most crucial limiting nutrient factor for plant growth in arid area, we applied quantitative real-time PCR (qPCR) to evaluate the variations in the abundance of bacteria, eukarya, archaea and N-transforming microorganisms (N-fixing microbes, ammonia-oxidizing bacteria and ammonia-oxidizing archaea), as affected by the habitat and rhizosphere. Meanwhile, the study also evaluated compositional shifts in bacterial and eukaryal communities using MiSeq amplicon sequencing. On this basis, we compared rhizosphere effects between these two shrubs in term of microbial activity (i.e., respiration), abundance and community structure, as well as for soil properties

MASPC_Transform: A Plant Point Cloud Segmentation Network Based on Multi-Head Attention Separation and Position Code

Plant point cloud segmentation is an important step in 3D plant phenotype research. Because the stems, leaves, flowers, and other organs of plants are often intertwined and small in size, this makes plant point cloud segmentation more challenging than other segmentation tasks. In this paper, we propose MASPC_Transform, a novel plant point cloud segmentation network base on multi-head attention separation and position code. The proposed MASPC_Transform establishes connections for similar point clouds scattered in different areas of the point cloud space through multiple attention heads. In order to avoid the aggregation of multiple attention heads, we propose a multi-head attention separation loss based on spatial similarity, so that the attention positions of different attention heads can be dispersed as much as possible. In order to reduce the impact of point cloud disorder and irregularity on feature extraction, we propose a new point cloud position coding method, and use the position coding network based on this method in the local and global feature extraction modules of MASPC_Transform. We evaluate our MASPC_Transform on the ROSE_X dataset. Compared with the state-of-the-art approaches, the proposed MASPC_Transform achieved better segmentation results

Periodic solutions and circuit design of chaos in a unified stretch-twist-fold flow

Based on the original stretch-twist-fold flow, we propose a unified stretch–twist–fold (USTF) flow. We explore the conditions that zero-Hopf bifurcation occurs at the origin. Using the first-order averaging theorem, a periodic solution produced from the zero-Hopf equilibrium is derived. In addition, we obtain the conclusion that for parameter $$\alpha$$ large enough, the periodic orbit of USTF flow exists as well unstable. Finally, circuit design has been built for implementing the new system, showing a good agreement between computer simulations and experimental observations

Characterizing the complete chloroplast genome of the Impatiens davidii (Balsaminaceae)

Impatiens davidii Franch, 1886 is a rare ornamental flower used in gardens and has high economic value. In this study, we characterized the chloroplast genome of I. davidii and analyzed its phylogenetic relationship with other Impatiens species. The length of the complete chloroplast genome sequence of I. davidii is 152,214 bp, with a GC content of 36.9%. The chloroplast genome shows a typical quadripartite structure with a pair of inverted repeats (IRs) of 25,634 bp, separated by one large single copy (LSC) region of 83,128 bp and one small single copy (SSC) region of 17,818 bp. We annotated 125 genes, of which there were 85 protein-coding genes, 32 tRNA genes, and 8 rRNA genes. The Bayesian phylogenetic tree strongly supports that I. davidii has a close phylogenetic relationship with a group including I. piufanensis and I. alpicola