Three Dimensional Reconfigurable Optical Singularities in Bilayer Photonic Crystals

Metasurfaces and photonic crystals have revolutionized classical and quantum manipulation of light, and opened the door to studying various optical singularities related to phases and polarization states. However, traditional nanophotonic devices lack reconfigurability, hindering the dynamic switching and optimization of optical singularities. This paper delves into the underexplored concept of tunable bilayer photonic crystals (BPhCs), which offer rich interlayer coupling effects. Utilizing silicon nitride-based BPhCs, we demonstrate tunable bidirectional and unidirectional polarization singularities, along with spatiotemporal phase singularities. Leveraging these tunable singularities, we achieve dynamic modulation of bound-state-in-continuum states, unidirectional guided resonances, and both longitudinal and transverse orbital angular momentum. Our work paves the way for multidimensional control over polarization and phase, inspiring new directions in ultrafast optics, optoelectronics, and quantum optics

Insecticidal activity and underlying molecular mechanisms of a phytochemical plumbagin against Spodoptera frugiperda

IntroductionPlumbagin is an important phytochemical and has been reported to exhibit potent larvicidal activity against several insect pests, However, the insecticidal mechanism of plumbagin against pests is still poorly understood. This study aimed to investigate the insecticidal activities of plumbagin and the underlying molecular mechanisms against a devastating agricultural pest, the fall armyworm Spodoptera frugiperda.MethodsThe effects of plumbagin on S. frugiperda larval development and the activities of two detoxification enzymes were initially examined. Next, transcriptomic changes in S. frugiperda after plumbagin treatment were investigated. Furthermore, RNA-seq results were validated by qPCR.ResultsPlumbagin exhibited a high larvicidal activity against the second and third instar larvae of S. frugiperda with 72 h LC50 of 0.573 and 2.676 mg/g, respectively. The activities of the two detoxification enzymes carboxylesterase and P450 were significantly increased after 1.5 mg/g plumbagin treatment. Furthermore, RNA-seq analysis provided a comprehensive overview of complex transcriptomic changes in S. frugiperda larvae in response to 1.5 mg/g plumbagin exposure, and revealed that plumbagin treatment led to aberrant expression of a large number of genes related to nutrient and energy metabolism, humoral immune response, insect cuticle protein, chitin-binding proteins, chitin synthesis and degradation, insect hormone, and xenobiotic detoxification. The qPCR results further validated the reproducibility and reliability of the transcriptomic data.DiscussionOur findings provide a valuable insight into understanding the insecticidal mechanism of the phytochemical plumbagin

Traffic classification-based spam filter

Abstract We propose an unsupervised spam filter called Bulk Mail Traffic Classification (BMTC

Effects of Compound Chinese Herbal Medicine Additive on Growth Performance and Gut Microbiota Diversity of Zi Goose

This study investigated the effects of CCHMA on growth performance, slaughter performance, serum biochemical indicators, intestinal morphology and microbiota of Zi goose. Initially, it was determined the optimal addition concentration of CCHMA to be 3 g/kg by the first feeding experiment. Then, 78 Zi geese were divided into control and CCHMA supplemented groups. The results showed that the body weight (BW) and average daily gain (ADG) of the CCHMA supplemented group was significantly increased (p < 0.05), and the feed/gain (F/G) of the CCHMA supplemented group was significantly decreased (p < 0.05) compared with the control group. The dressed yield percentage in the CCHMA supplemented group significantly increased by 0.78% (p < 0.05). Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were significantly lower in the CCHMA fed birds than in the control group (p < 0.05). Further, 16S rDNA gene sequencing conducted for cecal flora composition found that 3 g/kg CCHMA significantly increased the abundance of beneficial bacteria (CHKCI001, Colidextribacter and Subdoligranulum) (p < 0.05; p < 0.01) and suppressing harmful bacteria (Bacteroidetes and Methanobrevibacter) (p < 0.05) in the cecum of Zi goose. In conclusion, adding 3 g/kg of CCHMA in the diet can improve the growth performance, slaughter performance of Zi goose, and optimize the cecum microflora

This is FAST: multivariate Full-permutAtion based Stochastic foresT method-improving the retrieval of fine-mode aerosol microphysical properties with multi-wavelength lidar

Despite the small size and ubiquitous presence, fine-mode aerosols play a vital role in climate change and human health, especially in highly populated regions. Hitherto, some studies have been carried out to retrieve fine-mode aerosol microphysical properties from multi-wavelength lidar measurements. However, there has been a dearth of lidar-based methods with quality retrieval and high time efficiency to adequately quantify the impacts of fine-mode aerosols on Earth's energy budget. The reasons for the gap involve the limitations in current approaches and the nature of the under-determined problem with insufficient information of three backscattering coefficients (β) and two extinction coefficients (α), typically known as the 3β + 2α configuration. Furthermore, the latest lidars, especially for spaceborne and airborne applications, are inherently difficult to perform routine diurnal 3β + 2α observations with high resolution and require high processing speed for massive data. To overcome these conundrums, we developed a novel unsupervised machine learning method—multivariate Full-permutAtion based Stochastic foresT method (dubbed the FAST method)—to improve the retrieval of fine-mode aerosol microphysical properties. To the best of knowledge, this work is the first time that machine learning algorithms are employed in attempts to retrieve the aerosol microphysical properties with stand-alone multi-wavelength lidar data. The major merits of the FAST method include 1) high accuracy of fine-mode aerosol products with the typical 3β + 2α configuration, 2) acceptable performances for fewer input optical channels, and 3) high processing speed for large volume data. Comprehensive simulations have been conducted to investigate the error characteristic of the FAST method under different conditions. We also applied the FAST method to the airborne lidar data acquired during the NASA DISCOVER-AQ field campaign. The retrievals of the FAST method provide high resolution time-height distributions of fine-mode aerosol microphysical properties at 20-s temporal resolution and 45-m vertical resolution. In situ measurements are compared with multi-wavelength lidar retrievals showing good agreements. We achieved 0.010, 0.014 and 0.016 in terms of mean absolute difference for retrieved 532-nm single-scattering albedo with 3β + 2α, 3β + 1α, and 2β + 1α configurations, respectively. The proposed method is expected to represent an important step toward improving microphysical retrievals from multi-wavelength lidar data, especially for airborne and sp