200 research outputs found
The cyclophilin A DIAGEOTROPICA gene affects auxin transport in both root and shoot to control lateral root formation
Cyclophilin A is a conserved peptidyl-prolyl cis-trans isomerase (PPIase) best known as the cellular receptor of the immunosuppressant cyclosporine A. Despite significant effort, evidence of developmental functions of cyclophilin A in non-plant systems has remained obscure. Mutations in a tomato (Solanum lycopersicum) cyclophilin A ortholog, DIAGEOTROPICA (DGT), have been shown to abolish the organogenesis of lateral roots; however, a mechanistic explanation of the phenotype is lacking. Here, we show that the dgt mutant lacks auxin maxima relevant to priming and specification of lateral root founder cells. DGT is expressed in shoot and root, and localizes to both the nucleus and cytoplasm during lateral root organogenesis. Mutation of ENTIRE/IAA9, a member of the auxin-responsive Aux/IAA protein family of transcriptional repressors, partially restores the inability of dgt to initiate lateral root primordia but not the primordia outgrowth. By comparison, grafting of a wild-type scion restores the process of lateral root formation, consistent with participation of a mobile signal. Antibodies do not detect movement of the DGT protein into the dgt rootstock; however, experiments with radiolabeled auxin and an auxin-specific microelectrode demonstrate abnormal auxin fluxes. Functional studies of DGT in heterologous yeast and tobacco-leaf auxin-transport systems demonstrate that DGT negatively regulates PIN-FORMED (PIN) auxin efflux transporters by affecting their plasma membrane localization. Studies in tomato support complex effects of the dgt mutation on PIN expression level, expression domain and plasma membrane localization. Our data demonstrate that DGT regulates auxin transport in lateral root formation
Arabidopsis ABCB21 is a Facultative Auxin Importer/Exporter Regulated by Cytoplasmic Auxin Concentration
The phytohormone auxin is critical for plant growth and many developmental processes. Members of the P-glycoprotein (PGP/ABCB) subfamily of ATP-binding cassette (ABC) transporters have been shown to function in the polar movement of auxin by transporting auxin over the plasma membrane in both monocots and dicots. Here, we characterize a new Arabidopsis member of the ABCB subfamily, ABCB21/PGP21, a close homolog of ABCB4, for which conflicting transport directionalities have been reported. ABCB21 is strongly expressed in the abaxial side of cotyledons and in junctions of lateral organs in the aerial part, whereas in roots it is specifically expressed in pericycle cells. Membrane fractionation by sucrose density gradient centrifugation followed by Western blot showed that ABCB21 is a plasma membrane-localized ABC transporter. A transport assay with Arabidopsis protoplasts suggested that ABCB21 was involved in IAA transport in an outward direction, while naphthalene acetic acid (NAA) was a less preferable substrate for ABCB21. Further functional analysis of ABCB21 using yeast import and export assays showed that ABCB21 mediates the 1-N-naphthylphthalamic acid (NPA)-sensitive translocation of auxin in an inward direction when the cytoplasmic IAA concentration is low, whereas this transporter mediates outward transport under high internal IAA. An increase in the cytoplasmic IAA concentration by pre-loading of IAA into yeast cells abolished the IAA uptake activity by ABCB21 as well as ABCB4. These findings suggest that ABCB21 functions as a facultative importer/exporter controlling auxin concentrations in plant cell
LaneSegNet: Map Learning with Lane Segment Perception for Autonomous Driving
A map, as crucial information for downstream applications of an autonomous
driving system, is usually represented in lanelines or centerlines. However,
existing literature on map learning primarily focuses on either detecting
geometry-based lanelines or perceiving topology relationships of centerlines.
Both of these methods ignore the intrinsic relationship of lanelines and
centerlines, that lanelines bind centerlines. While simply predicting both
types of lane in one model is mutually excluded in learning objective, we
advocate lane segment as a new representation that seamlessly incorporates both
geometry and topology information. Thus, we introduce LaneSegNet, the first
end-to-end mapping network generating lane segments to obtain a complete
representation of the road structure. Our algorithm features two key
modifications. One is a lane attention module to capture pivotal region details
within the long-range feature space. Another is an identical initialization
strategy for reference points, which enhances the learning of positional priors
for lane attention. On the OpenLane-V2 dataset, LaneSegNet outperforms previous
counterparts by a substantial gain across three tasks, \textit{i.e.}, map
element detection (+4.8 mAP), centerline perception (+6.9 DET), and the
newly defined one, lane segment perception (+5.6 mAP). Furthermore, it obtains
a real-time inference speed of 14.7 FPS. Code is accessible at
https://github.com/OpenDriveLab/LaneSegNet.Comment: Accepted in ICLR 202
Pilot Investigation of Coal Chemical Wastewater Containing Phenol by Pervaporation Process
Coal chemical wastewater contains a large number of industrial raw materials, such as phenol, resulting in difficulty as target to be treated and the resource waste as industrial raw materials. A pilot pervaporation process is investigated to separate and recycle phenols from coal chemical wastewater to reduce the follow-up biochemical processing load. Operation parameters which affect removing and recovering efficiency are studied, such as temperature, flow rate and downstream pressure. Phenol removal efficiency could reach 50% under the conditions of 70o C, 210 L/h and 3000 Pa. The system could continuously run for 20 cycles. Furthermore, the pervaporation procedure could be enhanced when pumped with gas which made the removal efficiency up to 66%
OpenLane-V2: A Topology Reasoning Benchmark for Unified 3D HD Mapping
Accurately depicting the complex traffic scene is a vital component for
autonomous vehicles to execute correct judgments. However, existing benchmarks
tend to oversimplify the scene by solely focusing on lane perception tasks.
Observing that human drivers rely on both lanes and traffic signals to operate
their vehicles safely, we present OpenLane-V2, the first dataset on topology
reasoning for traffic scene structure. The objective of the presented dataset
is to advance research in understanding the structure of road scenes by
examining the relationship between perceived entities, such as traffic elements
and lanes. Leveraging existing datasets, OpenLane-V2 consists of 2,000
annotated road scenes that describe traffic elements and their correlation to
the lanes. It comprises three primary sub-tasks, including the 3D lane
detection inherited from OpenLane, accompanied by corresponding metrics to
evaluate the model's performance. We evaluate various state-of-the-art methods,
and present their quantitative and qualitative results on OpenLane-V2 to
indicate future avenues for investigating topology reasoning in traffic scenes.Comment: Accepted by NeurIPS 2023 Track on Datasets and Benchmarks |
OpenLane-V2 Dataset: https://github.com/OpenDriveLab/OpenLane-V
Levels and related factors of occupational stress among nurses: hospital-based evidence from China, 2023
BackgroundChina’s birth rate continues to decline, reaching only 6.39% in 2023. In light of this trend, hospitals may need to reassess their allocation of resources, including funding, staffing, and facilities. Nurses may face job insecurity and uncertainty regarding their roles, which could prompt some to consider transitioning to different specialties. This study aimed to investigate the levels of occupational stress among nurses in the context of low fertility in China in 2023 and to identify the factors contributing to this stress. In addition, the study sought to explore the relationship between family dysfunction, low fertility rates, and occupational stress levels.MethodsThis descriptive cross-sectional study involved 270 nurses working in hospitals, who were recruited between December 2023 and January 2024 through a Chinese free web-based platform (Sojump) to complete online questionnaires. In addition to demographic information, the Nursing Job Stressors Scale (NJSS) and the Family APGAR Index were utilized for data collection. The data were analyzed using descriptive and inferential statistics, including correlation and multiple linear regression analysis. For continuous variables, the mean, standard deviation (SD), median, and interquartile range were reported, while counts and percentages were used for categorical variables. The independent t-test and one-way analysis of variance were employed for univariate analysis. Multiple linear regression was utilized for multivariate analysis. A p-value of less than 0.05 was considered statistically significant.ResultsThe participants’ average scores for the NJSS and Family APGAR Index were 1.76 ± 0.58 and 6.35 ± 3.30 points, respectively. In addition, workload and time pressure were rated highest among the sub-scales of the NJSS. The top five job stressors for nurses were Q3 (Wages and other benefits are low), Q1 (The social status of nursing is too low), Q5 (Frequent shift work), Q12 (Too much useless paperwork), and Q16 (Fear of mistakes and accidents at work). The score of the Family APGAR Index demonstrated a negative correlation with occupational stress (r = −0.19, p < 0.001). The results of the multiple linear regression analysis showed that a high level of worry about losing one’s job (SE = 0.044, β = 0.152, t = 2.567, p = 0.011) and poorer family APGAR scores (SE = 0.035, β = −0.202, t = −3.406, p < 0.001) were associated with higher NJSS scores.ConclusionThe nurses reported experiencing a moderate level of occupational stress in the context of low fertility in China. The key predictors of occupational stress among the nurses included concerns about job security and the Family APGAR classification. Implementing fair compensation and providing more effective family-oriented support programs are essential for reducing occupational stress among nurses
Occurrence and genetic mechanism of pyrite in the No. 9 coal seam in magmatic erosion area of the Handan coalfield
The No. 9 coal of Yunjialing Coal Mine in Handan Coalfield, which is subject to obvious magmatic intrusion, is taken as the research object. Optical microscope observation, electron probe energy spectrometry (EPMA-EDS), X-ray diffractometer (XRD), X-ray fluorescence spectrometry (XRF) and other analytical tests were used to analyze the enrichment characteristics of whole sulfur, sulfur forms and minerals, to study the occurrence of sulfur and pyrite in the coals, and to explore the sources of different types of pyrite. The results show that the No. 9 coal of Yunjialing Coal Mine in Handan Coalfield is a high-sulfur coal (0.61%~7.12%), sulfide sulfur is the main form of sulfur in the coal (1.18%~4.90%), followed by organic sulfur (0.56%~2.16%) with a little sulphate sulfur (0.01%~0.06%). The No. 9 coal of Yunhailing coal mine was deposited in the transitional environment of sea and land phases, and seawater intrusion provided abundant sulfur source for the No. 9 coal seam, the gas-liquid materials brought about by neutral magmatism during the Yanshan period elevate the total sulfur content in the No. 9 coal of the Yunjialing Caol Mine, especially the total sulfur content of the upper coal plies are significantly higher than the total sulfur content of the whole coal seam. The microscopic occurrence of pyrite in the No. 9 coal mainly includes massive pyrite, disseminated pyrite and fissure-filled pyrite, and is characterized by multi-stage evolution. Massive pyrite is mainly formed in the early diagenetic stage, the high temperature and gas-liquid materials brought about by neutral magmatism during the Yanshan period modified the morphology of pyrite in the coal, resulting in the activation and recrystallization of pyrite in the coal into a massive fraction. Inorganic sulfur from the high-temperature-affected portion of the pyrite diffused into the surrounding coal body and sequestered as organic sulfur, increasing the organic sulfur content of the upper coal plies
FTIR characteristics of charcoal with different combustion degrees as an indication of the genesis by and their significances for formation of fusinite in coal
Fourier transform infrared spectroscopy (FTIR), as a non-destructive method, is widely used for the identification of compounds and the characterization of molecular structures. In order to characterize the changes in the chemical structure of charcoal under different combustion temperatures, and thus to provide a theoretical basis for the formation of fusinite in coal, plant samples (charcoal) from modern wildfires with different degrees of combustion were selected to quantify their chemical structures using FTIR. The results shown that the sample reflectance was positively proportional to the combustion temperature. The sample No. 1 with maximum combustion temperature had the highest degree of combustion, which was measured to reach 518 ℃. The aromatic structure was dominated by tri-substituted benzene rings in all samples except the highest combustion sample No. 1, but dehydrocondensation occurred with increasing combustion temperature, resulting in a reduction of tri-substituted content of benzene rings to 20.5%. The tetra-substituted content was elevated due to dehydroaromatization of the naphthenic structure, while the change in the penta-substituted content was related to the cyclization of aliphatic chain and the decarboxylation of benzene ring. With the increase of combustion temperature, the CC content gradually increased due to the formation of aromatic hydrocarbons or the shedding of molecular side chains after dehydrogenation of cycloalkanes, reached 32% in the sample No. 1. The content of C-O first decreased and then increased. In the sample No. 1, the content of alkyl ether and aryl ether was the lowest, and the content of phenolic hydroxyl group was the highest, which may be the generation of phenolic substances by thermal breakage of ether bond under high temperature combustion. The CO content increased and then decreased to as low as 5.6% in the sample No. 1, which was due to the poor stability of the bond. Due to the influence of combustion temperature, the content of fatty substances varied greatly, with an overall gradual increase in methylene content, a decrease in methyl group, and an increase in branching degree. There were five types of hydrogen bonds in the samples, with ether-oxygen hydrogen bonds predominating in samples affected by low temperature (>55%). Cyclic hydrogen bonds and hydroxyl-N hydrogen bonds appeared in sample No. 1, while the content of ether-oxygen hydrogen bonds decreased significantly to 13.2%, which was attributed to the reduction of oxygen-containing functional groups caused by the increasing temperature. Comparison of reflectance and FTIR characteristics of fusinite in coal revealed that the characteristics of fusinite (semifusinite) in coal were very similar to those of charcoal, which might be produced mainly by wildfires. These changes indicated the effect of combustion temperature on the chemical structure in charcoal, reflecting the process of organic molecular structure changed with temperature in charcoal, and providing a theoretical basis for the evolution of organic matter and the formation of fusinite in coal
Export of Salicylic Acid from the Chloroplast Requires the Multidrug and Toxin Extrusion-Like Transporter EDS5
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