UHPLC-MS/MS Analysis of the Accumulation and Excretion of Steroidal Glycoalkaloids Consumed by Potato Tuber Moth (<i>Phthorimaea operculella</i>) Larvae under Different Feeding Treatments

Food poisoning caused by potato glycoside alkaloids (SGA) remains a critical factor that affects potato production safety. The potato tuber moth (Phthorimaea operculella) is a notorious pest that displays good adaptability to SGA in potato tissues. Studies that explore the mechanisms underlying SGA homeostasis in potato tuber moth larvae are urgently needed. In this study, ultra-high-performance liquid chromatography (UHPLC)-triple quadrupole mass spectrometry (MS/MS) was applied to detect the dominant SGA substances α-solanine and α-chaconine in potato leaves and PTM larval tissues. From the highest to lowest SGA concentrations, the potato cultivars studied were ranked as follows: DS47, LS6, DS23 and QS9. To exclude the influence of nutrients within different potato varieties, different SGA containing (0%, 0.1%, 0.2%, 0.3% and 0.4%) the artificial diet treatment groups were added. DS47 and 0.3% SGA-containing artificial diets presented the best conditions for PTM growth, development and reproduction compared to other potato cultivars and artificial diet controls. The potato tuber moth larva tissues were dissected and the SGA content within different tissues were detected using an UHPLC machine. The results showed that α-chaconine was dispersed in the feces, midgut, hindgut, head and cuticle, and α-solanine was distributed only in the feces and midgut. Antibiotic-treated insects exhibited higher concentrations of SGA than the normal microbiome group. Furthermore, the SGA concentrations of 100 newly-hatched PTM larvae and puparia were detected, with both of them found to contain small amounts of SGA. The results showed that ecdysis and the excretion process were effective approaches used by the potato tuber moth to equilibrate internal SGA accumulation. The microorganism-decreased SGA concentrations were excited in their gut. SGA may transfer from adults to the next generation, and SGAs in PTM are inheritable. In this study, we demonstrated that the potato tuber moth possessed an effective method to preliminarily decrease high SGA accumulation in potato

Establishment of an Enteric Inflammation Model in Broiler Chickens by Oral Administration with Dextran Sulfate Sodium

This study aimed to evaluate the effectiveness of oral gavage of dextran sodium sulfate (DSS) to establish an enteric inflammation model in broilers. Forty 1-day-old male, yellow-feathered broilers were randomly divided into 2 groups with 5 replicates of 4 birds each for a 42-day trial. The experiment design used 2 groups: (1) the control group (CT), normal broilers fed a basal diet, and (2) the DSS group, DSS-treated broilers fed a basal diet. The DSS group received 1 mL of 2.5% DSS solution once a day by oral gavage from 21 to 29 days of age. The results showed that compared with those in CT, DSS treatment significantly increased histological scores for enteritis and mucosal damage at 29 and 42 days of age (p p p < 0.01). DSS also caused gross lesions and histopathological damage in the jejunum of broilers, such as obvious hemorrhagic spots, loss of villus architecture, epithelial cell disruption, inflammatory cell infiltration, and decreased villus height. These results suggest that oral gavage of DSS is an effective method for inducing mild and non-necrotic enteric inflammation in broilers

A Prismatic Conformal Metasurface for Radar Cross-Section Reduction

A prismatic conformal metasurface, based on optimized multielement phase cancellation (OMEPC), is proposed for wideband radar cross-section (RCS) reduction. The metasurface is composed of 35 lattices located in 7 zones of a prismatic structure. The lattices in different zones are simulated under corresponding incident angles and taken into account the difference of wave path caused by the bending of the conformal structure. The interactions between multiple backscattered waves produced by the lattices are manipulated, and optimized simultaneously by the hybrid array pattern synthesis and particle swarm optimization (PSO) to achieve wideband destructive interference. The proposed metasurface can realize a 10 dB reduction in backscattered RCS under normal incidence for HH polarization from 9.6 to 10.6 GHz and 11.7 to 17.7 GHz with the fractional bandwidths of 9.9% and 40.8%, respectively. The theoretical analysis, simulated, and measured results are in a good agreement. The proposed approach verifies the innovation and effectiveness in achieving wideband RCS reduction for conformal metasurface

Effects of the combined application of biomaterial amendments and polyacrylamide on soil water and maize growth under deficit irrigation

Combined applications of mixing bio-materials amendments and polyacrylamide (MBAP) to maize in semiarid areas has the potential to improve soil physical properties such that improved crop performance may be obtained under deficient irrigation management. In this study, three MBAP applications were: C0 (conventional N fertilization application); C2 and C4 (MBAP applied at rates of 2 and 4 t ha-1, respectively); three irrigation levels were: W3 (nearly full irrigation, 85%–100% of field capacity), W2 (light deficit irrigation, 65%–75% of field capacity), W1 (medium deficit irrigation, 55%–65% of field capacity). Under the same irrigation level, the MBAP significantly decreased soil bulk densities and increased soil hydraulic conductivities and soil water contents. The effects of irrigation levels on soil bulk densities and soil saturated hydraulic conductivities were not significant. Consequently, MBAP improved soil conditions for maize growth and increased grain and biomass yields, especially at the two deficit irrigation levels. Compared with C0, grain yields for C2 and C4 were increased by 52.8 and 39.3% under W2, and by 23.5 and 13.7% under W1, respectively. MBAP and irrigation had significant interaction effects on ET during sowing to jointing, and on plant heights at 32 d after sowing. The incorporation of MBAP (2 t ha-1) and chemical fertilizer (111.8 kg N ha-1) resulted in the greatest yields under light deficit irrigation and seemed the best approach to improve soil physical properties and sustain maize productivity using limited water resources in dryland regions.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

A Prismatic Conformal Metasurface for Radar Cross-Section Reduction

A prismatic conformal metasurface, based on optimized multielement phase cancellation (OMEPC), is proposed for wideband radar cross-section (RCS) reduction. The metasurface is composed of 35 lattices located in 7 zones of a prismatic structure. The lattices in different zones are simulated under corresponding incident angles and taken into account the difference of wave path caused by the bending of the conformal structure. The interactions between multiple backscattered waves produced by the lattices are manipulated, and optimized simultaneously by the hybrid array pattern synthesis and particle swarm optimization (PSO) to achieve wideband destructive interference. The proposed metasurface can realize a 10 dB reduction in backscattered RCS under normal incidence for HH polarization from 9.6 to 10.6 GHz and 11.7 to 17.7 GHz with the fractional bandwidths of 9.9% and 40.8%, respectively. The theoretical analysis, simulated, and measured results are in a good agreement. The proposed approach verifies the innovation and effectiveness in achieving wideband RCS reduction for conformal metasurface.This is a manuscript of an article published as Wang, Yajin, Jianxun Su, Zengrui Li, Qingxin Guo, and Jiming Song. "A Prismatic Conformal Metasurface for Radar Cross-Section Reduction." IEEE Antennas and Wireless Propagation Letters (2020). DOI: 10.1109/LAWP.2020.2974018. Posted with permission.</p

iLibScope: Reliable Third-Party Library Detection for iOS Mobile Apps

Vetting security impacts introduced by third-party libraries in iOS apps requires a reliable library detection technique. Especially when a new vulnerability (or a privacy-invasive behavior) was discovered in a third-party library, there is a practical need to precisely identify the existence of libraries and their versions for iOS apps. However, few studies have been proposed to tackle this problem, and they all suffer from the code duplication problem in different libraries. In this paper, we focus on third-party library detection in iOS apps. Given an app, we aim to identify the integrated libraries and pinpoint their versions (or the version range).To this end, we first conduct an in-depth study on iOS third-party libraries to demystify the code duplication challenge. By doing so, we have two key observations: 1) even though two libraries can share classes, the shared classes cannot be integrated into an app simultaneously without causing a class name conflict; and 2) code duplication between multiple versions of two libraries can vary. Based on these findings, we propose a novel profile-based similarity comparison approach to perform the detection. Specifically, we build a library database consists of original library binaries with distinct versions. After extracting profiles for each library version and the target app, we conduct a similarity comparison to find the best matches. We implemented this approach in iLibScope. We built a benchmark consists of 5,807 apps with 10,495 library integrations and applied our tool to it. Our evaluation shows that iLibScope achieves a recall exceeds 99% and a precision exceeds 97% for library detection. We also applied iLibScope to detect the presence of well-known vulnerable third-party libraries in real-world iOS mobile apps to show the promising usage of our tool. It successfully identified 405 vulnerable library usage from 4,249 apps.Comment: 11 pages, 7 figure

Dating with Scambots:understanding the ecosystem of fraudulent dating applications

In this work, we are focusing on a new and yet uncovered way for malicious apps to gain profit. They claim to be dating apps. However, their sole purpose is to lure users into purchasing premium/VIP services to start conversations with other (likely fake female) accounts in the app. We call these apps as fraudulent dating apps. This paper performs a systematic study to understand the whole ecosystem of fraudulent dating apps. Specifically, we have proposed a three-phase method to detect them and subsequently comprehend their characteristics via analyzing the existing account profiles. Our observation reveals that most of the accounts are not managed by real persons, but by chatbots based on predefined conversation templates. We also analyze the business model of these apps and reveal that multiple parties are actually involved in the ecosystem, including producers who develop apps, publishers who publish apps to gain profit, and the distribution network that is responsible for distributing apps to end users. Finally, we analyze the impact of them to users (i.e., victims) and estimate the overall revenue. Our work is the first systematic study on fraudulent dating apps, and the results demonstrate the urge for a solution to protect users