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Shrimp has been one of the most favorite seafood for years. It is essential to timely estimate the amount of feed left in the bait tray after feeding in shrimp aquaculture. Feeding strategies can also be adjusted to reduce the bait costs in recent years. The traditional detection of residual baits can rely on visual inspection by the shrimp farmers. Neural networks and deep learning have been introduced to detect and count the residual baits at present. However, large-scale neural networks cannot be successfully implemented on mobile devices, due mainly to the low recognition accuracy and large model computation. In this study, the improved model was proposed to estimate the density map of residual baits using a hybrid dilated convolution and attention multi-scale network (HAMNet). The high accuracy and low complexity were achieved in the detection models of residual bait. The HAMNet model was divided into three components: A low-level feature extractor (LLFE), a high-level feature extractor (HLFE), and a density map restorer and generator (DMRG). These components served as the front-end, the middle-end, and the back-end network of the improved model, respectively. Firstly, inspired by the multi-column convolutional neural network (MCNN), the parallel convolution block (PCB) was designed in the front-end network, in order to extract the feature information of residual bait at multiple scales within a single-column architecture; At the same time, the hybrid dilated convolution block (HDCB) was introduced into the mid-end network to expand the receptive field, in order to further learn the multi-scale features. Secondly, a channel attention mechanism (CAM) was embedded into the network to recalibrate the weights of useful feature information using the interdependence among channels, in order to highlight the difference between the target and background. Finally, the learnable transposed convolutional layers were applied in the back-end network to recover the detailed information from the feature maps. The quality of density maps was improved to reduce the counting errors. As such, the high-quality density map was then obtained during downsampling in the front-end network. In addition, the effectiveness of the improved model was validated using residual bait images under bait tray conditions. A comparison was also implemented with the classical networks of density map estimation. Comparative experiments showed that the HAMNet model was achieved in the minimum mean absolute error (MAE) of 2.0, the minimum root mean square error (RMSE) of 2.9, and the least floating point operations (FLOPs) at 6.55 G on the residual bait datasets, with a parameter count of only 0.52MB. The HAMNet model shared the higher counting accuracy and stability with the lower computational complexity. Compared with the baseline MCNN network, the improved model achieved a 44.4% reduction in MAE, a 40.8% reduction in RMSE, and a 13.7% reduction in FLOPs. Compared with the CMTL, SANet, and CSRNet, the optimal balance was obtained in all performance metrics. In summary, the HAMNet model outperformed the rest, in terms of overall performance, thus improving the counting accuracy with the low computational volume. The finding can provide a strong reference to rapidly quantify the residual baits in shrimp aquaculture. Novel ideas were also offered to deploy the detection models of residual bait on the platforms with limited computational power. [ABSTRACT FROM AUTHOR]

The wave load characteristics of a deep-water vertical breakwater with a posterior wave wall were summarized and analyzed, the wave pressure theory of the Chinese code, the modified Goda formula and the Sanflou simplified formula were used for calculate, the calculation is compared with the wave pressure test results of section physical models and local integral physical models, and the differences were analyzed. It is proposed that when the relative water depth is relatively large, using the recommended formula of Chinese code can more reasonably simulate the wave pressure curve, and suggestions are made for the selection of Chinese code wave pressure calculation methods. A new wave pressure calculation method is recommended for the wave pressure analysis of posterior wave walls. It is recommended to use this method when there are no wave crossing requirements at the top of the breakwater and the mooring stability of the harbour basin needs to be improved, which can improve the structural forces. [ABSTRACT FROM AUTHOR]

Baiting is an important part of shrimp pond culture, and obtaining the weight of the remaining bait is the key to achieving accurate baiting. In order to solve the problem of inaccurate weighing of the remaining bait caused by the environment, the system itself and other factors, an adaptive strong-tracking unscented Kalman filtering algorithm （SHFL-ASTUKF） for the dynamic weighing of the bait on baiting boats is proposed. Firstly, a second-order model of the weighing system was established and the measurement results were filtered. Then, based on the fast introduction of the asymptotic cancellation factor, the singular value decomposition was used to replace the Cholesky decomposition to deal with the error covariance problem. Meanwhile, the fuzzy control algorithm and Sage-Husa adaptive filtering were combined to adaptively update the measurement noise covariance and the system noise covariance, so as to suppress the divergence in the filtering process. Example data simulation and experimental validation of SHFL-ASTUKF show that, compared with the strong tracking unscented Kalman filter, the RMSE is improved by 14.9% in the example data simulation, and the RMSE is improved by an average of 15.15% in the experiments of the bait weighing of the remaining bait in the baiting boat and the MAE is improved by 17.27%. The proposed algorithm has higher dynamic measurement accuracy and better noise reduction effect. [ABSTRACT FROM AUTHOR]

A project is located in a relatively backward and isolated region of an island country in the Pacific Ocean and it is planned to build a fixed navigation aid structure. On the one hand, higher international standards are adopted for the design based on the stringent requirements of the consultants; on the other hand, the design scheme is restricted by various construction conditions such as lifting weight and length of components and excavation depth. After comparisons of multiple schemes, a high-strength steel pole + expanded concrete foundation scheme is innovatively adopted for the pile foundation of the navigation aids. For the first time, high-strength structural steel is applied to the foundation of port engineering navigation facilities, meeting the strict requirements of the consultants and the construction restrictions. At the same time, the traditional mechanical connection technology for steel structures is applied to the foundation structure of harbor engineering, providing reference for similar projects. [ABSTRACT FROM AUTHOR]

[Objective] Flower yellowing disease ( FYD) is one of the most significant diseases affecting Zanthoxylum sp. in recent years, leading to yield losses in susceptible Zanthoxylum spp. In the study, high-throughput sequencing technology was employed to analyze the potential pathogens responsible for FYD, aiming to provide a basis for pathogen identification and disease control. [ Method] The flower and leaf samples of four plants with FYD symptoms and two asymptomatic plants of Z. armatum var. yongqing 1 were collected for virome analysis. [Result] Sequencing data analysis indicated that a total of 484 contings from six samples matrched 15 virus species belonging to 12 different viral families. Among these six samples, four previously reported viruses were detected in Z. armatum var. novemfolius: Green Sichuan pepper-nepovirus ( GSPNe V), Green Sichuan pepper-idaeovirus ( GSPIV), Green Sichuan pepper-enamovirus ( GSPEV), Green Sichuan pepper-nucleorhabdovirus ( GSPNuV). Notably, previously unreported viruses in Zanthoxylum spp. included two novel RNA viruses tentatively named Yongqing green pepper-associated umhravirus and Yongqing green pepper-associated ssRNA negative-strand virus. Additionally, Potato virus Y (PVY) was detected in symptomatic D-2 and asymptomatic H-1 samples. Potato virus M (PVM), Potato virus H ( PVH), Potato virus S ( PVS), all belonging to the genus Carlavirus in the family Betaflexiviridae, were identified in FYD plant samples of D-2, D-3 and D4. Furthermore, the grapevine rubestris stem pitting associated virus (GRSPAV) of the genus Foveavirus was detected exclusively in the D-1 sample. [ Conclusion] All four reported viruses as well as two new unreported viruses were detected in the sequenced samples from Y ongqing 1, and the genus Carlavirus, which was only present in the symptomatic group, was detected, and it was inferred that the highly expressed viruses of the genus Carlavirus should be regarded as one of the factors that induced FYD. [ABSTRACT FROM AUTHOR]

In response to the current situation that most of the bait feeders in pond culture rely on manpower, which is labor-intensive, and it is difficult to feed the baiting boats on steep sloping banks, an energy-saving feeding truck without power discharging has been designed. The truck uses a rotating discharging valve for feeding, and a scissor lift platform for adjusting the height of feeding. Through the design of the spherical limit rotating connector located at the discharge port of the rotating discharging valve to adjust the inclination angle of the feeding tube to realize the non-powered discharging, a new type of telescopic feeding tube is designed based on cylindrical cam. The feeding truck can realize directional, fixed-distance and fixed-point feed addition through the movement of the truck body, the lifting and lowering of the scissor lift platform, and the adjustment of the inclination angle and length of the feeding tube. The prototype of the feeding truck was made, and the feeding test was carried out with the baiting boat and stationary baiting machine as the feeding target, and the test results show that the feeding truck has the universality for different specifications of feeds, and the telescopic length of 1.2 m and the lifting height of 1.5 m can satisfy the feeding needs of the baiting boat and stationary baiting machine, and the adjusting is flexible, and the rate of feeding is 6.2 kg/min. The designed feeding truck is flexible in use, and it can replace the manual feeding to the baiting boat and stationary baiting machine. It can replace manual feeding for baiting boat and fixed baiting machine, reduce manual labor intensity, improve the mechanization level of breeding process, and lay the foundation for further automation and intelligence. [ABSTRACT FROM AUTHOR]

Favourable water quality is the basis of pond healthy aquaculture. In order to realize the automation of monitoring and sampling, an integrated unmanned water quality monitoring and sampling boat was designed and its performance test was carried out. Considering the requirements of water quality monitoring and sampling, the hull structure was designed, and the layout of the functional areas of water quality sensor, sampling system, power supply, control box, and water sample collection bottles in the cabin was designed considering the load bearing and stability. The autonomous cruise control system was developed based on the differential twin-propellers driven model and the integration of GPS and attitude sensor. The water sampling control system and water quality monitoring data platform were integrated with Internet of Things technology. The comprehensive test results showed that the trajectory of unmanned boat was accurate, the maximum deviation of monitoring point was 1.49 m, the minimum deviation was 0.39 m, and the average deviation was 1.003 m. The water quality monitoring and sampling function was stable, and the pH value, water temperature and dissolved oxygen of water could be returned in real time. Six 500 mL water sampling bottles could collect water samples of underwater 50 cm accurately, which is in line with national standards. The results provide a low-cost and reliable implementation scheme for the whole surface water quality monitoring of aquaculture. [ABSTRACT FROM AUTHOR]

[ Objective] Tomato spotted wilt orthotospovirus ( TSWV) had occurred worldwide and caused seriously economic losses on many crops. It was one of the efficient path via screening of natural products with high inhibited activity to prevention and control of the diseases caused by TSWV. Our previous study indicated that kaurenic acid ( AHK) extracted from Wedelia trilobata has a high effect against TSWV infection. In this study, we want to prove up the mechanism of AHK inhibition. [ Method] Detected the activities of defense enzymes and the expression of systemic acquired resistance ( SAR)-related genes by RT-qPCR from the tobacco plants before and post inoculated TSWV and treatment AHK, and analyzed the mechanism of inhibited by AHK. [Result] AHK induced superoxide dismutase (SOD) activity rised and inhibited TSWV infection. Meanwhile, AHK induced the increasing of MYC2 and NAC expression levels which were important transcription factors of Jasmonic Acid ( JA) pathway. [ Conclusion]AHK mainly induced the increasing of SOD activity and JA signaling pathway to enhance host SAR for inhibiting TSWV infection, and AHK had potential for the research and development of botanical pesticides for bases of prevention and contrl the diseases caused by TSWV. [ABSTRACT FROM AUTHOR]

[Objective] (Tob acco mosaic virus (TMV) infects tobacco，tomato，pepper and other cash crops and causes huge economic losses to agricultiaral production，antiviral lead compounds and theoretical basis were provided for controlling TMV virias disease by using low toxici¬ ty and high eficiency botanical agents. [Method( Lesion counting was used to detect the activities of TMVafter treating with 11 sesquiterpe- noids from CH!。*— 【Result】11 sesquiterpenoids (100 "g/mL) were sprayed after being inoculated with TMVfor 24 hours，the inhibition rate of Euphorblin E (HZ-7) was 67. 54 '，which was higher than that of the control Ningnanmycin (52. 89 '); inoculated with TMVafter rprayed 11 sesquiterpenoids for 6 hours，the inhibition rate of Euphorblin E (HZ-7) was 72. 29 '，which was higher than that of the control Ningnanmycin (58 . 21 ') .【Conclusion 】The compound Euphorblin E from could be used as a lead compound for the development of environment friendly pesticides against TMV. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to investigate occurrence and distribution of Potato virus A(PVA), and analyze genetic variation of PVA in Yunnan Province. [Method] Using DAS-ELISA, 389 potato samples from 19 potato-growing regions of Yunnan Province were tested.Using RT-PCR, P3 protein genes of PVA from 5 positive potato samples were amplified, cloned and sequenced.P3 protein gene sequences of 5 PVA isolates from different regions of Yunnan Province and other 13 PVA isolates were analyzed by DNAMAN and DNAStar, and phylogenetic tree was constructed by Neighbor-joining(NJ) method of MEGA6.0. [Result] The positive sample detertion rates of PVA were 20.82 % among 389 samples. The DNA fragments of 1041 bp were amplified from 5 positive samples of PVA from different regions of Yunnan Province by RT-PCR with the specific primers for P3 protein gene. The sequence analysis results showed that there were higher amino acid sequence identities 98.8 %-99.7 % and 97.6%-100.0 % of P3 and PIPO proteins between 5 Yunnan PVA isolates than amino acid sequence identities 90.8 %-99.1 % and 90.5 %-100.0 % of P3 and PIPO proteins between Yunnan 5 PVA isolates and other 13 PVA isolates.Phylogenetic tree results showed that genetic relationship was the most close between 5 Yunnan isolates andthe Hunan isolate of PVA(KF977085).Contrastly, genetic relationship was most far between PVAisolates from potato and those from tamarillo. [Conclusion] PVA was prevalent in Yunnan province. There was genetic variation between PVA isolates in Yunnan Province. The phylogenetic tree analysis showed that PVA isolates had host adaptability. [ABSTRACT FROM AUTHOR]