Large-scale environment mapping and immersive human-robot interaction for agricultural mobile robot teleoperation

Remote operation is a crucial solution to problems encountered in agricultural machinery operations. However, traditional video streaming control methods fall short in overcoming the challenges of single perspective views and the inability to obtain 3D information. In light of these issues, our research proposes a large-scale digital map reconstruction and immersive human-machine remote control framework for agricultural scenarios. In our methodology, a DJI unmanned aerial vehicle(UAV) was utilized for data collection, and a novel video segmentation approach based on feature points was introduced. To tackle texture richness variability, an enhanced Structure from Motion (SfM) using superpixel segmentation was implemented. This method integrates the open Multiple View Geometry (openMVG) framework along with Local Features from Transformers (LoFTR). The enhanced SfM results in a point cloud map, which is further processed through Multi-View Stereo (MVS) to generate a complete map model. For control, a closed-loop system utilizing TCP for VR control and positioning of agricultural machinery was introduced. Our system offers a fully visual-based immersive control method, where upon connection to the local area network, operators can utilize VR for immersive remote control. The proposed method enhances both the robustness and convenience of the reconstruction process, thereby significantly facilitating operators in acquiring more comprehensive on-site information and engaging in immersive remote control operations. The code is available at: https://github.com/LiuTao1126/Enhance-SF

Advanced Mapping of the Seafloor Using Sea Vehicle Mounted Sounding Technologies

A large proportion of the Earth’s surface is the deep sea. Numerous fields require access to seafloor topography and geomorphology. With the emergence of different types of underwater vehicles, especially the commercialization of near-seafloor micro-topographical mapping sonars, near-seafloor micro-topographical detection in the deep sea is possible. Near-seafloor micro-topographical exploration allows accurate detection of the seafloor using multibeam echosounder, side-scan sonar, and bathymetric side-scan sonar carried on-board various vehicles, including deep-tow, autonomous underwater vehicles, remotely operated vehicles, and human-occupied vehicles. Near-seafloor micro-topographical detection can obtain more accurate micro-topography and micro-geomorphology of the seafloor compared to full sea depth topographical detection. In this chapter, the basic principles of three types of near-seafloor micro-topographical mapping sonars are analyzed. Then, four types of underwater vehicles that are suitable for near-seafloor micro-topographical mapping are briefly discussed. Factors affecting mapping and detection results are presented using the Jiaolong human-occupied vehicle and its bathymetric side-scan sonar as an example. Next, the entire data processing and mapping methods are described. Finally, two typical detection results obtained by the Jiaolong bathymetric side-scan sonar in deep-sea are given

‘Relax and Repair’ to restrain aging

The maintenance of genomic integrity requires the precise identification and repair of DNA damage. Since DNA is packaged and condensed into higher order chromatin, the events associated with DNA damage recognition and repair are orchestrated within the layers of chromatin. Very similar to transcription, during DNA repair, chromatin remodelling events and histone modifications act in concert to ‘open’ and relax chromatin structure so that repair proteins can gain access to DNA damage sites. One such histone mark critical for maintaining chromatin structure is acetylated lysine 16 of histone H4 (AcH4K16), a modification that can disrupt higher order chromatin organization and convert it into a more ‘relaxed’ configuration. We have recently shown that impaired H4K16 acetylation delays the accumulation of repair proteins to double strand break (DSB) sites which results in defective genome maintenance and accelerated aging in a laminopathy-based premature aging mouse model. These results support the idea that epigenetic factors may directly contribute to genomic instability and aging by regulating the efficiency of DSB repair. In this article, the interplay between epigenetic misregulation, defective DNA repair and aging is discussed

Distribution and Abundance of Archaea in South China Sea Sponge Holoxea sp. and the Presence of Ammonia-Oxidizing Archaea in Sponge Cells

Compared with bacterial symbionts, little is known about archaea in sponges especially about their spatial distribution and abundance. Understanding the distribution and abundance of ammonia-oxidizing archaea will help greatly in elucidating the potential function of symbionts in nitrogen cycling in sponges. In this study, gene libraries of 16S rRNA gene and ammonia monooxygenase subunit A (amoA) genes and quantitative real-time PCR were used to study the spatial distribution and abundance of archaea in the South China Sea sponge Holoxea sp. As a result, Holoxea sp. specific AOA, mainly group C1a (marine group I: Crenarchaeota) were identified. The presence of ammonia-oxidizing crenarchaea was observed for the first time within sponge cells. This study suggested a close relationship between sponge host and its archaeal symbionts as well as the archaeal potential contribution to sponge host in the ammonia-oxidizing process of nitrification

A Dynamic Linear Hashing Method for Redundancy Management in Train Ethernet Consist Network

Massive transportation systems like trains are considered critical systems because they use the communication network to control essential subsystems on board. Critical system requires zero recovery time when a failure occurs in a communication network. The newly published IEC62439-3 defines the high-availability seamless redundancy protocol, which fulfills this requirement and ensures no frame loss in the presence of an error. This paper adopts these for train Ethernet consist network. The challenge is management of the circulating frames, capable of dealing with real-time processing requirements, fast switching times, high throughout, and deterministic behavior. The main contribution of this paper is the in-depth analysis it makes of network parameters imposed by the application of the protocols to train control and monitoring system (TCMS) and the redundant circulating frames discarding method based on a dynamic linear hashing, using the fastest method in order to resolve all the issues that are dealt with

Characteristics of multiple‐year nitrous oxide emissions from conventional vegetable fields in southeastern China

The annual and interannual characteristics of nitrous oxide (N2O) emissions from conventional vegetable fields are poorly understood. We carried out 4 year measurements of N2O fluxes from a conventional vegetable cultivation area in the Yangtze River delta. Under fertilized conditions subject to farming practices, approximately 86% of the annual total N2O release occurred following fertilization events. The direct emission factors (EFd) of the 12 individual vegetable seasons investigated ranged from 0.06 to 14.20%, with a mean of 3.09% and a coefficient of variation (CV) of 142%. The annual EFd varied from 0.59 to 4.98%, with a mean of 2.88% and an interannual CV of 74%. The mean value is much larger than the latest default value (1.00%) of the Intergovernmental Panel on Climate Change. Occasional application of lagoon‐stored manure slurry coupled with other nitrogen fertilizers, or basal nitrogen addition immediately followed by heavy rainfall, accounted for a substantial portion of the large EFds observed in warm seasons. The large CVs suggest that the emission factors obtained from short‐term observations that poorly represent seasonality and/or interannual variability will inevitably yield large uncertainties in inventory estimation. The results of this study indicate that conventional vegetable fields associated with intensive nitrogen addition, as well as occasional applications of manure slurry, may substantially account for regional N2O emissions. However, this conclusion needs to be further confirmed through studies at multiple field sites. Moreover, further experimental studies are needed to test the mitigation options suggested by this study for N2O emissions from open vegetable fields

Radical Scavenging Activity of Black Currant (\u3ci\u3eRibes nigrum\u3c/i\u3e L.) Extract and Its Inhibitory Effect on Gastric Cancer Cell Proliferation via Induction of Apoptosis

A black currant extract (BCE) was prepared and its antiproliferative activity against gastric cancer SGC-7901 cells was investigated. Strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical scavenging activities and a high reducing power were confirmed with BCE. BCE inhibited the proliferation of SGC-7901 cells in a dose- and time-dependent manner, and the IC50 were 12.7, 10.2 and 9.0 mg/mL for 12, 24 and 48 h, respectively. Morphologic observations with inverted and fluorescence microscopes yielded vivid evidence of cell shrinkage, formation of cytoplasmic filaments, condensation of nuclear chromatin, and cell apoptosis in the presence of BCE. Flow cytometric analysis also showed that BCE treatment at concentrations of 10–20 mg/mL resulted in marked reductions of viable cells. The high concentration of phenolic compounds present in the BCE (12.2 mg/mL), including six prominent anthocyanins identified by HPLC–ESI-MS2, appeared to be responsible for BCE’s antiradical activity and anticancer effects. These findings of inhibition of SGC-7901 cells and induction of apoptosis suggest that black currant may contribute to the reduction in gastric cancer risk