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

Topology Reasoning for Driving Scenes

Understanding the road genome is essential to realize autonomous driving. This highly intelligent problem contains two aspects - the connection relationship of lanes, and the assignment relationship between lanes and traffic elements, where a comprehensive topology reasoning method is vacant. On one hand, previous map learning techniques struggle in deriving lane connectivity with segmentation or laneline paradigms; or prior lane topology-oriented approaches focus on centerline detection and neglect the interaction modeling. On the other hand, the traffic element to lane assignment problem is limited in the image domain, leaving how to construct the correspondence from two views an unexplored challenge. To address these issues, we present TopoNet, the first end-to-end framework capable of abstracting traffic knowledge beyond conventional perception tasks. To capture the driving scene topology, we introduce three key designs: (1) an embedding module to incorporate semantic knowledge from 2D elements into a unified feature space; (2) a curated scene graph neural network to model relationships and enable feature interaction inside the network; (3) instead of transmitting messages arbitrarily, a scene knowledge graph is devised to differentiate prior knowledge from various types of the road genome. We evaluate TopoNet on the challenging scene understanding benchmark, OpenLane-V2, where our approach outperforms all previous works by a great margin on all perceptual and topological metrics. The code would be released soon

Sciences for The 2.5-meter Wide Field Survey Telescope (WFST)

The Wide Field Survey Telescope (WFST) is a dedicated photometric survey facility under construction jointly by the University of Science and Technology of China and Purple Mountain Observatory. It is equipped with a primary mirror of 2.5m in diameter, an active optical system, and a mosaic CCD camera of 0.73 Gpix on the main focus plane to achieve high-quality imaging over a field of view of 6.5 square degrees. The installation of WFST in the Lenghu observing site is planned to happen in the summer of 2023, and the operation is scheduled to commence within three months afterward. WFST will scan the northern sky in four optical bands (u, g, r, and i) at cadences from hourly/daily to semi-weekly in the deep high-cadence survey (DHS) and the wide field survey (WFS) programs, respectively. WFS reaches a depth of 22.27, 23.32, 22.84, and 22.31 in AB magnitudes in a nominal 30-second exposure in the four bands during a photometric night, respectively, enabling us to search tremendous amount of transients in the low-z universe and systematically investigate the variability of Galactic and extragalactic objects. Intranight 90s exposures as deep as 23 and 24 mag in u and g bands via DHS provide a unique opportunity to facilitate explorations of energetic transients in demand for high sensitivity, including the electromagnetic counterparts of gravitational-wave events detected by the second/third-generation GW detectors, supernovae within a few hours of their explosions, tidal disruption events and luminous fast optical transients even beyond a redshift of 1. Meanwhile, the final 6-year co-added images, anticipated to reach g about 25.5 mag in WFS or even deeper by 1.5 mag in DHS, will be of significant value to general Galactic and extragalactic sciences. The highly uniform legacy surveys of WFST will also serve as an indispensable complement to those of LSST which monitors the southern sky.Comment: 46 pages, submitted to SCMP

Effect of Different Types of Erosion on the Aerodynamic Performance of Wind Turbine Airfoils

Taking the S823 airfoil as the research object, this study investigates the influence of different types of leading-edge erosion on the aerodynamic performance of airfoil by using the computational fluid dynamics method. The effect of leading-edge erosion on the inception of stall vortex is also analysed. The results show that when the angle of attack (AoA) is greater than 5°, the leading-edge erosion results in a significant decrease in the lift coefficient and an increase in the drag coefficient. The deterioration in the drag coefficient of the airfoil caused by leading-edge erosion is much greater than that of the lift coefficient. Moreover, the maximum promotion rate of the drag coefficient can reach 357% at Re = 300,000. The exacerbation of the erosion level leads to a dramatic expansion of the stall vortex on the airfoil suction side at a large AoA and results in a reduction in the pressure difference between the pressure and suction sides of the airfoil. This is also the reason erosion causes the degradation of the aerodynamic performance of the wind turbine airfoil. This work is beneficial to establish the reasonable maintenance cycle of the wind turbine blades working in a sand blown environment

Recent Advances in Rapid Synthesis of Non-proteinogenic Amino Acids from Proteinogenic Amino Acids Derivatives via Direct Photo-Mediated C–H Functionalization

Non-proteinogenic amino acids have attracted tremendous interest for their essential applications in the realm of biology and chemistry. Recently, rising C–H functionalization has been considered an alternative powerful method for the direct synthesis of non-proteinogenic amino acids. Meanwhile, photochemistry has become popular for its predominant advantages of mild conditions and conservation of energy. Therefore, C–H functionalization and photochemistry have been merged to synthesize diverse non-proteinogenic amino acids in a mild and environmentally friendly way. In this review, the recent developments in the photo-mediated C–H functionalization of proteinogenic amino acids derivatives for the rapid synthesis of versatile non-proteinogenic amino acids are presented. Moreover, postulated mechanisms are also described wherever needed

Highly Reversible Zn Anodes through a Hydrophobic Interface Formed by Electrolyte Additive

Hydrogen evolution reaction and dendrite growth seriously break the Zn plating/stripping process at the electrolyte/electrode interface, causing the instability of the Zn anode of aqueous zinc ion batteries. To improve the Zn anode stability and reversibility, we report a new electrolyte additive of aqueous electrolyte with the hydrophobic group. This interfacial hydrophobicity maximises the exclusion of free water from the Zn anode surface, which blocks water erosion and reduces interfacial side reactions. Thus, in an optimal 2 M ZnSO4 electrolyte with 2 g·L−1 Tween-85, the hydrogen evolution reaction and other water-induced undesired reactions can be suppressed, which greatly improves the cycling stability and Coulombic efficiency (CE) of Zn plating/stripping process. The stable cycle time of the Zn//Zn symmetric battery reaches over 1300 h, especially at a high current density and a high areal capacity (more than 650 h at 5 mA·cm−2, 5 mAh·cm−2). The average Coulomb efficiency (CE) of Zn//Ti asymmetric cell achieves 98.11% after 300 cycles. The capacity retention rate of Zn//MnO2 full battery is up to 88.6% after 1000 cycles

SOX2 enhances the migration and invasion of ovarian cancer cells via Src kinase.

Ovarian cancer is the leading cause of death among gynecologic cancers and is the fifth leading cause of all cancer-related deaths among women. The development of novel molecular targets is therefore important to many patients. Recently, the SRY-related transcription factor SOX2 has been widely reported to be involved in multiple pathophysiological diseases, including maintenance of stem cell characteristics and carcinogenesis. Up to now, SOX2 has been mainly shown to promote the development of cancer, although its inhibitory roles in cancer have also been reported. However, the role of SOX2 in ovarian cancer is largely unknown. In the present study, we detected the expression of SOX2 in 64 human serous ovarian carcinoma (SOC) tissues and paired corresponding metastatic specimens using immunohistochemistry. The results showed that the expression of SOX2 in primary tumors is much lower than that in the corresponding metastatic lesions. We further found that SOX2 overexpression promotes proliferation, migration and invasion, while inhibiting adhesion abilities of SOC cells. Finally, we found that SOX2 targets Src kinase, a non-receptor tyrosine kinase that regulates cell migration, invasion and adhesion in SOC cells. Together, these results suggested that Src kinase is a key molecule in SOX2-mediated migration and invasion of SOC cells

Structural analysis of an anthrol reductase inspires enantioselective synthesis of enantiopure hydroxycycloketones and β-halohydrins

Asymmetric reduction of prochiral ketones is challenging. Here, the authors identify and solve the structure of anthrol reductase CbAR, whose variant H162F can convert 1,3-cyclodiketones and α-haloacetophenones to the corresponding chiral alcohols

Transmission of ST45 and ST2407 extended-spectrum β-lactamase-producing Klebsiella pneumoniae in neonatal intensive care units, associated with contaminated environments

ABSTRACT: Objectives: Given the increasing frequency of infections due to extended-spectrum β-lactamase (EBSL)-producing Klebsiella pneumoniae in humans over recent decades, infection control against this pathogen is of high importance. Methods: In this study, the transmission mode of ESBL-producing K. pneumoniae in neonatal intensive care units (NICU) was investigated. We collected K. pneumoniae isolates from patients admitted to the NICU and performed environmental screening of the NICU and nearby obstetrics department. All isolates were analysed using antimicrobial susceptibility testing, whole-genome sequencing, molecular typing, and antimicrobial and virulence determinant screening. The phylogenetic relationships of all the isolates were analysed using core-genome multi-locus sequence type and single-nucleotide polymorphism-based analysis, and their plasmids harbouring antimicrobial resistance genes in ST2407 were compared. Results: Eighteen K. pneumoniae isolates were collected, of which 10 isolates from patients belonged to ST45 and ST2407, and eight isolates from the environment belonged to various other clones. Although 80% and 100% of isolates from patients were ESBL-positive (blaCTX-M-14 and blaCTX-M-55) and possessed siderophores, respectively; fewer environmental isolates harboured antimicrobial resistance and virulence genes. For both ST45 and ST2407 isolates, the phylogenetic assessment revealed a close relationship between clinical and environmental isolates, indicating that bloodstream infections were associated with the contaminated environments. Conclusions: Based on these results, the environmental prevalence of K. pneumoniae should be considered given its pathogenicity in humans. Early and active infection control measures could decrease the spread of multidrug-resistant K. pneumoniae