Search

Deck motion prediction and compensation are critical technologies for carrier-based aircraft automatic landing. Traditional deck motion prediction methods rely on precision of motion models and parameter adjustments, facing challenges in adaptability to complex sea conditions, different types of carriers, changes in flight conditions, and limitations in prediction duration, as well as reliability issues. This paper proposes a deck motion prediction method based on the neural kernel network Gaussian process regression (NKN-GPR) model. The NKN-GPR model can utilize a neural kernel network (NKN) to automatically construct the Gaussian process regression (GPR) model′s composite kernel, effectively addressing the limitations of the automated kernel search (ACKS) algorithm, which heavily depends on manual prior knowledge. Simulation data is generated using a combination of sine wave and power spectrum models, and the NKN-GPR model is compared with an autoregressive (AR) model based on least squares in a simulated validation. The simulation results demonstrate that the NKN-GPR model exhibits significant advantages in motion prediction accuracy, smoothness, and prediction duration, which confirms the effectiveness of the proposed algorithm. This study provides theoretical support for safe automatic landing of carrier-based aircraft.

Abstract Next-generation sequencing allows for fine-scale studies of microbial communities. Herein, 16S ribosomal RNA high-throughput sequencing was used to identify, classify, and predict the functions of the bacterial communities in the eggs and ovaries of Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae), which is a pest that infests a variety of cucurbit fruits at different developmental stages. Taxonomic analyses indicate that bacteria associated with B. cucurbitae represent 19 phyla, which were spread across different developmental stages. Specifically, the egg microbiota had a higher alpha diversity than those of microbiota in the primary and mature ovaries. Significant differences were not observed between the primary and mature ovaries in terms of their microbiota’s alpha diversities. Pseudomonadota, Deinococcota, Bacteroidota, Bacillota, and Actinomycetota were the dominant phyla in all three developmental stages of B. cucurbitae, and Pseudomonadaceae and Enterobacteriaceae were the most abundant families. Owing to the unique physiological environment of the ovaries, the diversity of their bacterial community was significantly lower than that in the eggs. This study provides new insights into the structure and abundance of the microbiota in B. cucurbitae at different developmental stages and contributes to forming management strategies for this pest.

This paper presented a mechanics-based method to address the typical lateral stability issue of railway trains. A Base Electric Multiple Unit (Base EMU) and an upgraded EMU were used as the research objects. Mechanics-based models were developed for both systems; the Base EMU model was validated using actual test data. Different wheel-rail equivalent conicity values and suspension parameters were investigated. The results showed that inadequate wheel-rail guiding capacity under low conicity can led to the occurrence of lateral stability issues. When the train is pushed by motor cars, coupler lateral forces aggravate stability issues. Altering the yaw damper's angle and damping properties can significantly reduce lateral swaying and improve the ride index. This represents a low-cost and favored solution. Decreasing the stiffness of the axle box pull rod is also effective in mitigating low-frequency lateral swaying. [ABSTRACT FROM AUTHOR]

The cotton bollworm causes severe mechanical damage to plants during feeding and leaves oral secretions (OSs) at the mechanical wounds. The role these OSs play in the invasion of plants is still largely unknown. Here, a novel H. armigera effector peptidyl prolyl trans‐isomerase 5 (PPI5) was isolated and characterized. PPI5 induces the programmed cell death (PCD) due to the unfolded protein response (UPR) in tobacco leaf. We reveal that PPI5 is important for the growth and development of cotton bollworm on plants, as it renders plants more susceptible to feeding. The GhFKBP17‐2, was identified as a host target for PPI5 with peptidyl‐prolyl isomerase (PPIase) activity. CRISPR/Cas9 knock‐out cotton mutant (CR‐GhFKBP17‐1/3), VIGS (TRV: GhFKBP17‐2) and overexpression lines (OE‐GhFKBP17‐1/3) were created and the data indicate that GhFKBP17‐2 positively regulates endoplasmic reticulum (ER) stress‐mediated plant immunity in response to cotton bollworm infestation. We further confirm that PPI5 represses JA and SA levels by downregulating the expression of JA‐ and SA‐associated genes, including JAZ3/9, MYC2/3, JAR4, PR4, LSD1, PAD4, ICS1 and PR1/5. Taken together, our results reveal that PPI5 reduces plant defense responses and makes plants more susceptible to cotton bollworm infection by targeting and suppressing GhFKBP17‐2 ‐mediated plant immunity. [ABSTRACT FROM AUTHOR]

The wheel wear of heavy-duty locomotives is more complicated than that of other vehicles when it affects tractive force and adhesion control. The purpose of this article is to calculate wheel wear on a curved track using a co-simulation dynamic model of a heavy-duty locomotive with adhesion control. Additionally, the effect of creep threshold, decline slope, curve radius, and passing speed on wheel wear is further investigated. The findings demonstrate that wheel wear can be successfully decreased by adjusting the creep threshold and decline slope of adhesion control parameters. The wheel-rail stick-slip vibration behavior on the curve track can be eliminated by increasing the curve's radius and passing speed, but the vertical wear at the left wheel's flange will rise sharply with the increase of passing speed on right hand curve. [ABSTRACT FROM AUTHOR]

Insulin receptors (InR) are an integral component of the insulin/insulin‐like growth factor signaling pathway, which plays a vital role in insect development, lifespan, reproduction, and olfactory sensitivity. However, whether InR participate in the peripheral olfactory system of insects remains unclear. Recently, we found that 2‐heptanone (2‐HT) affects AcerInR expression, the gene for an InR protein, in Apis cerana cerana. We then examined the spatiotemporal expression profile of the gene in A. cerana cerana. The mRNA of AcerInR was primarily expressed in the antennae, wings, and legs of forager bees, which are probable chemosensory tissues. The results of fluorescence competitive binding assays, combined with site‐directed mutagenesis, demonstrated that AcerOBP6 and AcerOBP14 exhibit strong binding affinities to 2‐HT. Furthermore, after foragers were fed with double‐stranded AcerInR, the expression levels of AcerOBP6 and AcerOBP14 decreased significantly, as did the electroantennogram responsiveness to 2‐HT and some other odorants. In conclusion, our findings provide a foundation for understanding the involvement of AcerInR in the odor perception of A. cerana cerana. Moreover, they offer novel insights into the olfactory recognition mechanism in insects. [ABSTRACT FROM AUTHOR]