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Tumor immune escape refers to the inability of the immune system to clear tumor cells, which is one of the major obstacles in designing effective treatment schemes for cancer diseases. Although clinical studies have led to promising treatment outcomes, it is imperative to design theoretical models to investigate the long-term treatment effects. In this paper, we develop a mathematical model to study the interactions among tumor cells, immune escape tumor cells, and T lymphocyte. The chimeric antigen receptor (CAR) T-cell therapy is also described by the mathematical model. Bifurcation analysis shows that there exists backward bifurcation and saddle-node bifurcation when the immune intensity is used as the bifurcation parameter. The proposed model also exhibits bistability when its parameters are located between the saddle-node threshold and backward bifurcation threshold. Sensitivity analysis is performed to illustrate the effects of different mechanisms on the backward bifurcation threshold and basic immune reproduction number. Simulation studies confirm the bifurcation analysis results and predict various types of treatment outcomes using different CAR T-cell therapy strengths. Analysis and simulation results show that the immune intensity can be used to control the tumor size, but it has no effect on the control of the immune escape tumor size. The introduction of the CAR T-cell therapy will reduce the immune escape tumor size and the treatment effect depends on the CAR T-cell therapy strength. [ABSTRACT FROM AUTHOR]

Recent evidences show that individuals who recovered from COVID-19 can be reinfected. However, this phenomenon has rarely been studied using mathematical models. In this paper, we propose an SEIRE epidemic model to describe the spread of the epidemic with reinfection. We obtain the important thresholds R 0 (the basic reproduction number) and R c (a threshold less than one). Our investigations show that when R 0 > 1 , the system has an endemic equilibrium, which is globally asymptotically stable. When R c < R 0 < 1 , the epidemic system exhibits bistable dynamics. That is, the system has backward bifurcation and the disease cannot be eradicated. In order to eradicate the disease, we must ensure that the basic reproduction number R 0 is less than R c . The basic reinfection number is obtained to measure the reinfection force, which turns out to be a new tipping point for disease dynamics. We also give definition of robustness, a new concept to measure the difficulty of completely eliminating the disease for a bistable epidemic system. Numerical simulations are carried out to verify the conclusions. [ABSTRACT FROM AUTHOR]

In the process of landscaping or afforestation in challenging terrain, in order to improve the survival rate of transplanted seedlings, it is necessary to transplant seedlings with a mother soil ball attached. During transportation, the soil ball at the root of the seedlings is very susceptible to breakage due to compression, bumps, and collisions. In order to ensure the integrity of the soil ball of the transplanted seedlings and improve the survival rate of seedlings, a method of chemically enhancing the soil surface strength was employed. Specifically, a polymer-based soil consolidating agent was used to solidify the root balls of the seedlings. To examine the abrasion resistance performance of the soil balls formed by consolidating the surface with polymer adhesive during the transportation process, we utilized a polymer-based consolidating agent to prepare test soil columns and developed a method to simulate the damage resistance performance of seedling root balls during transportation using these soil columns. The method primarily encompasses two aspects of testing: compressive strength testing of the consolidated soil columns and resistance to transportation vibration testing. The first method for testing the resistance to transportation vibration of the consolidated soil columns is a combination test that includes three sets of tests: highway truck transportation vibration testing, combined wheel vehicle transportation vibration testing, and impact testing. Although the method is cumbersome, testing is more accurate. The second method for testing the resistance to transportation vibration of the consolidated soil columns involves simultaneously testing multiple consolidated soil columns using a simulated transportation vibration test platform. The testing method is concise and efficient, and the test results are more intuitive. The combined assessment of the resistance to transportation vibration and compressive strength testing of the consolidated soil columns allows for a comprehensive evaluation of the soil columns' resistance to damage during transportation. This study mainly provides a quick and effective method for detecting the damage resistance of consolidated soil columns/balls during transportation, providing technical support for the application of polymer-based consolidation agents in the field of seedling transplantation. [ABSTRACT FROM AUTHOR]

Gastric cancer (GC) is one of the major causes of cancer deaths with 5-year survival ratio of 20%. RNU12 is one of long noncoding RNAs (lncRNAs) regulating the tumor progression. However, how RNU12 affecting GC is not clear. qRT-PCR was utilized for determining the RNU12 expression in cell lines, 113 cases of paired gastric cancer (GC) and their adjacent normal gastric tissues. The biofunction alterations of RNU12 were assessed by its overexpression or knockdown in GC cells. MTT and cloning assay were assayed for the cell proliferation, the flow cytometry for the detection of cell cycle and the wound healing assay (WHA) and transwell invasion assay (TIA) for examining the migration and invasion of cells. The expressions of a set of genes related proliferation and migration were investigated with the Western Blotting (WB). RNA immunoprecipitation (RIP), biotinylated RNA pull-down and dual luciferase reporter tests were used to detect the interactions of RNU12 with miR-575/BLID. The in vivo proliferation and migration ability of RNU12 infected cells were determined in zebrafish system. This study revealed that RNU12 inhibited proliferation, invasion and metastasis by sponging of miR-575 and regulating the downstream BLID and modulated EMT of GC cells. The RNU12/miR-575/BLID axis is likely to be the prognosis biomarkers and drug targets of GC. [ABSTRACT FROM AUTHOR]

Purpose: Nasopharyngeal carcinoma (NPC) is ranked the top otorhinolaryngology malignant tumors in the world. However, the general prognosis of recurrent and metastatic (R/M) nasopharyngeal carcinomas (NPCs) remains poor, and current surgery and chemoradiotherapy do not generate satisfactory outcomes. Methods: As a new therapeutic choice, immunotherapy, especially with regard to the development of checkpoint inhibitors including PD-1 and CTLA-4 inhibitors have made considerable progress in recent years. As Epstein-Barr virus (EBV) infection is associated with increased risk of NPC, EBV-related immunotherapy may lead to a breakthrough in advanced NPCs. Results: In this review, we summarized the clinical characters of NPC, and several past and ongoing clinical trials of checkpoint inhibitors and EBV-CTLs (CTLs: cytotoxic T lymphocytes) in R/M NPC immunotherapy. Conclusion: We conclude that although the evaluated effects of new immunotherapy drugs have brought us hope on NPC treatment, further phase II-III trials with larger samples are still required to improve the proportion and scheme of drug collocation for better clinical outcomes and less drug-related safety. [ABSTRACT FROM AUTHOR]

Laryngeal disease classification is a relatively hard task in medical image processing resulting from its complex structures and varying viewpoints in data collection. Some existing methods try to tackle this task via the convolutional neural network, but they more or less ignore the intrinsic difficulty differences among different input samples and suffer from high training complexity. In order to better resolve these problems, an end-to-end Hierarchical Dynamic Convolutional Network (HDCNet) is proposed, which can dynamically process the input samples based on their difficulty. For the easy-classified samples, the HDCNet processes them with a smaller resolution and a relatively small network, while the difficult samples are passed to a large network with a larger resolution for more accurate classification results. Furthermore, a Feature Reuse Module (FRM) is designed to transfer the features learned by the small network to the corresponding block in the deep network to enhance the overall performance of some rather complicated samples. To validate the effectiveness of the proposed HDCNet, comprehensive experiments are conducted on the public available laryngeal disease classification dataset and HDCNet provides superior performances compared with other current state-of-the-art methods. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated that immune impairment is an essential factor in viral infection for disease development and treatment. In this paper, we formulate an age-structured viral infection model with a nonmonotonic immune response and perform dynamical analysis to explore the effects of both immune impairment and virus control. The basic infection reproduction number is derived for a general viral production rate, which determines the global stability of the infection-free equilibrium. For the immune intensity, we get two important thresholds, the post-treatment control threshold and the elite control threshold. The interval between the two thresholds is a bistable interval, where there are two immune-present infected equilibria. When the immune intensity is greater than the elite control threshold, only one immune-present infected equilibrium exists and it is stable. By assuming the death rate and virus production rate of infected cells to be constants, with the immune intensity as a bifurcation parameter, the system exhibits saddle-node bifurcation, transcritical bifurcation, and backward/forward bifurcation. [ABSTRACT FROM AUTHOR]

Recently, bistable viral infection systems have attracted increased attention. In this paper, we study bistability and robustness for virus infection models with nonmonotonic immune responses in viral infection systems. The results show that the existing transcritical bifurcation undergoes backward or forward bifurcation in viral infection models with nonmonotonic immune responses. Our investigation demonstrates that the backward bifurcation threshold is the elite control threshold. When the immune intensity is greater than the elite control threshold, the virus will be under elite control; when the immune intensity is less than the elite control threshold, the virus may rebound. We also give a new definition of robustness to characterize bistable systems. [ABSTRACT FROM AUTHOR]

In order to improve the survival rate of transplanted seedlings and improve the efficiency of seedling transplantation, we developed an environmental friendly polymer konjac glucomannan (KGM)/chitosan (CA)/polyvinyl alcohol (PVA) ternary blend soil consolidation agent to consolidate the soil ball at the root of transplanted seedlings. In the previous research, we found that although the prepared KGM/CA/PVA ternary blend soil consolidation agent can consolidate the soil ball at the root of the seedling, the medium solid content of the adhesive was high, which affects its spraying at the root of the seedling. At the same time, the preparation temperature of the KGM/CA/PVA ternary blend was also high. Therefore, to reduce the energy consumption and the cost of the KGM/CA/PVA ternary blend soil consolidation agent in the preparation process, this paper studied the influence of preparation conditions on the application performance of the environmental friendly polymer soil consolidation agent. We aimed to reduce the highest value CA content and preparation temperature of the KGM/CA/PVA ternary blend adhesive on the premise of ensuring the consolidation performance of the KGM/CA/PVA ternary blend adhesive on soil balls. It was prepared for the popularization and application of the environmental friendly polymer KGM/CA/PVA ternary blend soil consolidation agent in seedling transplanting. Through this study, it was found that the film-forming performance of the adhesive was better when the KGM content was 4.5%, the CA content was in the range of 2–3%, the PVA content was in the range of 3–4%, and the preparation temperature was higher than 50 °C. The polymer soil consolidation agent prepared under this condition has a good application prospect in seedling transplanting. [ABSTRACT FROM AUTHOR]

Background: Anastomosis group 1 IA (AG1-IA) of Rhizoctonia solani is the major agent of banded leaf and sheath blight (BLSB) disease that causes severe yield loss in many worldwide crops. MicroRNAs (miRNAs) are ~ 22 nt non-coding RNAs that negatively regulate gene expression levels by mRNA degradation or translation inhibition. A better understanding of miRNA function during AG1-IA infection can expedite to elucidate the molecular mechanisms of fungi-host interactions. Results: In this study, we sequenced three small RNA libraries obtained from the mycelium of AG1-IA isolate, non-infected maize sheath and mixed maize sheath 3 days after inoculation. In total, 137 conserved and 34 novel microRNA-like small RNAs (milRNAs) were identified from the pathogen. Among these, one novel and 17 conserved milRNAs were identified as potential virulence-associated (VA) milRNAs. Subsequently, the prediction of target genes for these milRNAs was performed in both AG1-IA and maize, while functional annotation of these targets suggested a link to pathogenesis-related biological processes. Further, expression patterns of these virulence-associated milRNAs demonstrated that theyparticipate in the virulence of AG1-IA. Finally, regulation of one maize targeting gene, GRMZM2G412674 for Rhi-milRNA-9829-5p, was validated by dual-luciferase assay and identified to play a positive role in BLSB resistance in two maize mutants. These results suggest the global differentially expressed milRNAs of R. solani AG1-IA that participate in the regulation of target genes in both AG1-IA and maize to reinforce its pathogenicity. Conclusions: Our data have provided a comprehensive overview of the VA-milRNAs of R. solani and identified that they are probably the virulence factors by directly interfered in host targeting genes. These results offer new insights on the molecular mechanisms of R.solani-maize interactions during the process of infection. [ABSTRACT FROM AUTHOR]

Transplanting trees with rhizospheric soil is an important way to facilitate tree survival in the process of landscaping and reforestation. Traditional way to prevent looseness of rhizospheric soil is forming soil balls around the roots with bags, boxes or rope wrapping, which is cumbersome, laborious and easy to break. This study is aimed to develop a new type of degradable environment-friendly polymer as soil consolidation agent to facilitate tree transplanting. In this paper, the KGM/CA/PVA ternary blending soil consolidation agent was prepared by using Konjac glucomannan (KGM), chitosan (CA) and polyvinyl alcohol (PVA) as raw materials. Through the verification and evaluation, the clay and sandy soil can be consolidated and formed into soil balls by the ternary blend adhesive, which was convenient for transportation. The preliminary application of the ternary blend adhesive in the transplanting process of sierra salvia, Japanese Spindle (Euonymus japonicus) and Juniperus sabina 'Tamaricifolia' confirmed that the application of soil consolidation agent can effectively solve the problem that the root ball of seedling is easily broken in the process of transplant. And the application of soil consolidation agent has no adverse effect on the growth of transplanted seedlings. The research and development of ternary blending soil consolidation agent and its preliminary application in seedling transplanting will provide a new solution to solve the problem of soil ball breakage in the process of seedling transplanting. This is an important stage in the development of new seedling transplanting technology. Therefore, the research and development of soil consolidation agent is of great significance. [ABSTRACT FROM AUTHOR]

In this paper, certain delayed virus dynamical models with cell-to-cell infection and density-dependent diffusion are investigated. For the viral model with a single strain, we have proved the well-posedness and studied the global stabilities of equilibria by defining the basic reproductive number R 0 and structuring proper Lyapunov functional. Moreover, we found that the infection-free equilibrium is globally asymptotically stable if R 0 < 1 , and the infection equilibrium is globally asymptotically stable if R 0 > 1. For the multi-strain model, we found that all viral strains coexist if the corresponding basic reproductive number R j 𝜖 > 1 , while virus will extinct if R j 𝜖 < 1. As a result, we found that delay and the density-dependent diffusion does not influence the global stability of the model with cell-to-cell infection and homogeneous Neumann boundary conditions. [ABSTRACT FROM AUTHOR]

In this paper, a prey–predator-top predator food chain model with nonmonotonic functional response in the predators is studied. With an emphasis on the nutrition conversion rate of predator to top predator, one can get two important thresholds: the top predator extinction threshold and the coexistence threshold. The top predator will die out if the nutrition conversion rate of predator to top predator is less than the top predator extinction threshold; the prey, predator and top predator will coexist if the rate is larger than the coexistence threshold. While between the two thresholds is a bistable interval. When the nutrition conversion rate of predator to top predator is in the bistable interval, the system will see the emergence of bistability. The bifurcation analysis of the system depending on parameters indicates that it exhibits saddle-node bifurcation and Hopf bifurcation phenomena. [ABSTRACT FROM AUTHOR]

In this paper, we construct a mathematical model to investigate the interaction between the tumor cells, the immune cells and the helper T cells (HTCs). We perform mathematical analysis to reveal the stability of the equilibria of the model. In our model, the HTCs are stimulated by the identification of the presence of tumor antigens. Our investigation implies that the presence of tumor antigens may inhibit the existence of high steady state of tumor cells, which leads to the elimination of the bistable behavior of the tumor-immune system, i.e. the equilibrium corresponding to the high steady state of tumor cells is destabilized. Choosing immune intensity c as bifurcation parameter, there exists saddle-node bifurcation. Besides, there exists a critical value c ∗ , at which a Hopf bifurcation occurs. The stability and direction of Hopf bifurcation are discussed. [ABSTRACT FROM AUTHOR]

Highlights • A general discharge formula (Eq. 16 and 18) of the improved subsurface drainage with ponded water in a homogeneous and isotropic soil was proposed, considering the saturated and unsaturated filter condition which may happen during the improved subsurface drainage working time, verified by three methods of laboratory experiment and field test and numerical simulation. • The turning condition to distinguish the saturated and unsaturated working condition of the improved subsurface drainage was discussed by simulation. That (b 0 + h 0)/ d equaled 0.6 could be regarded as the boundary between filter saturated and unsaturated working condition. • The condition that the drain spacing was three times of impermeable layer depth could be regarded as a critical condition to simplify the complete formula. • Additionally, when the impermeable layer depth is unknown, the formula to estimate the discharge of the improved subsurface drainage roughly was given. Abstract The improved subsurface drainage is a new drainage technique which has large discharge verified by experiments. It can be used to solve the problems of frequent floods and cultivated land shortage in South China. Considering large-scale applications, a general drainage formula of the improved subsurface drainage with ponded water in a homogeneous and isotropic soil was proposed based on Kirkham equation. Firstly, the drainage formulas based on different assumptions were deduced and verified by laboratory experiment and field test. Additionally, further validation and simplification were studied by numerical simulation in which the critical conditions to distinguish whether the filter was saturated or not were given. Results showed that the proposed formulas passed the validation by laboratory experiment and field test based on Method 1 and Method 2 in which the bottom of the simplified boundary overlapped with the bottom of the drain pipe and the center of simplified boundary located at the center of filter were assumed respectively. The numerical simulation results showed the formula based on Method 1 was more applicable than that based on Method 2. Moreover, for Method 1, that (b 0 + h 0)/ d equaled 0.6 could be regarded as the critical boundary between filter saturated and unsaturated working condition. Considering the ratio of drain distance and impermeable layer depth, a more simplified formula was given. In this simplified formula, that drain spacing was three times of impermeable layer depth was a critical condition. The research results could provide scientific basis for improved subsurface drainage design and lay a good foundation for its application. Meanwhile, it would be beneficial to enrich agricultural drainage technologies and promote development of agricultural drainage in China. [ABSTRACT FROM AUTHOR]

This paper considers the problem of predicting a supply chain cost for prefabricated building construction under an uncertain situation. Based on the Activity-Based Costing (ABC) method, we establish a computational model to estimate the total cost of the prefabricated supply chain. The model can assist in not only finding the critical areas for cost reduction of the whole supply chain but also analyzing other costs of prefabricated construction projects. Furthermore, we provide a numerical example of prefabricated building construction to validate the results. [ABSTRACT FROM AUTHOR]

This paper is concerned with a phytoplankton–zooplankton model with toxin delay. It is shown that the positive equilibrium of the system is stable when the toxin delay is not included. However, we find that the incorporation of a discrete toxin delay not only can destabilize the positive equilibrium of the system but also can cause a Hopf bifurcation at the positive equilibrium as it crosses some critical values. In particular, the normal form of the Hopf bifurcation arising in the system is determined to investigate the direction and the stability of periodic solutions bifurcating from these Hopf bifurcations. To verify the obtained conditions, a special numerical example is also included. These results in this work demonstrate that the toxin delay plays an important role on deriving the complex dynamics. [ABSTRACT FROM AUTHOR]

In this paper, we investigate an impaired or immunosuppressive HIV infection model. By analyzing the model, we obtain two thresholds R 0 and R c . It is shown that R 0 determines whether the virus dies out. We also obtain the post-treatment control threshold and the elite control threshold. There exists a bistable interval between these two thresholds. When R 0 > R c , immune intensity is in the bistable interval, which implies that the system has bistable behavior and as such the virus is under post-treatment control. On the other hand, when the immune intensity is greater than the elite immune control threshold, virus will be under elite control. Our investigation shows that when antiviral therapy cannot completely clear the virus, introducing immunotherapy is an optimal choice. [ABSTRACT FROM AUTHOR]

New requirements are put forward for agricultural drainage system due to frequent floods and cultivated land shortage in Huaibei plain, China. The improved subsurface drainage is a more efficient drainage system by laying high permeability materials as filter above the drains based on conventional subsurface drainage whose function is limited by soil hydraulic conductivity. Field experiments was used to evaluate the performance of the improved subsurface drainage preliminarily and numerical experiments was used to explore the capacity of the improved subsurface drainage deeply. Based on calibration and validation by field experiment data, HYDRUS model was used to evaluate the impacts of design parameters of filter hydraulic conductivity, filter width and height, drain spacing and depth on improved subsurface drainage discharge with constant ponding depth. Then, water table depths at different distances from the pipe drain for improved and conventional subsurface drainage were simulated under initial conditions of saturated soil and no surface ponding. Besides, the daily water balance under improved subsurface drainage had been also studied. The result of field experiment showed that the discharge of improved subsurface drainage was about 1.9 times of the conventional subsurface drainage discharge under conditions of same surface ponding depths. The results of numerical experiments indicated that the improved subsurface drainage had a real-time drainage function for the reason that cumulative outflow increased by about 87% than conventional subsurface drainage within 12 h after beginning draining. The improved subsurface drainage lowered water table to an appropriate depth faster than conventional ones, which could provide a more favourable soil moisture condition for crop growth. Furthermore, through daily water balance analysis of improved and conventional subsurface drainage with different rainfalls and initial water table depths, the results showed that subsurface drainage could reduce surface runoff effectively, especially for improved subsurface drainage. Good drainability of the improved subsurface drainage was beneficial to decrease the amount of soil water storage after rainfall and helpful to shorten subsequent draining time of water table drawdown. The research results could provide scientific basis for improved subsurface drainage design and lay a good foundation for its application. Meanwhile, it would be beneficial to enrich agricultural drainage technologies and promote development of agricultural drainage in China. [ABSTRACT FROM AUTHOR]

Some HIV-infected patients (the so-called post-treatment controllers) can control the virus after cessation of antiretroviral therapy. A small fraction of patients can even naturally maintain undetectable viral load without therapy (they are called elite controllers). The immune response may play an important role in viral control in these patients. In this paper, we analyze a within-host model including immune response to study the virus dynamics in HIV-infected patients. We derived two threshold values for the immune cell proliferation parameter. Below the lower immune proliferation rate, the model has a stable immune-free steady state, which predicts that patients have a high viral load. Above the higher immune proliferation rate, the model has a stable low infected steady state, which indicates that patients are under elite control. Between the two immune thresholds, the model exhibits the dynamic behavior of bistability, which suggests that patients either undergo viral rebound after treatment termination or achieve the post-treatment control. These results may explain the different virus dynamics in HIV-infected patients. [ABSTRACT FROM AUTHOR]

Density-dependent diffusion plays an important role in the process of viral infection. In this paper, we construct mathematical models to investigate the dynamics of the viruses and their control. Single strain and multi-strain viral infections are both considered in this work. Using the method proposed by Pao and Ruan (2013), we prove the well-posedness of the models. By constructing appropriate Lyapunov functions, we proved the global asymptotical stabilities of the models. For the multi-strain model, we show that when the basic reproduction number for each strain is greater than one, all viral strains coexist. Since the effect of different treatments may result in competitive exclusion, it is essential to employ the treatment with combined therapy. We find with surprise that the density-dependent diffusion of the virus does not influence the global stabilities of the model with homogeneous Neumann boundary conditions. [ABSTRACT FROM AUTHOR]

In this work, we integrate both density-dependent diffusion process and Beddington-DeAngelis functional response into virus infection models to consider their combined effects on viral infection and its control. We perform global analysis by constructing Lyapunov functions and prove that the system is well posed. We investigated the viral dynamics for scenarios of single-strain and multi-strain viruses and find that, for the multi-strain model, if the basic reproduction number for all viral strains is greater than 1, then each strain persists in the host. Our investigation indicates that treating a patient using only a single type of therapy may cause competitive exclusion, which is disadvantageous to the patient's health. For patients infected with several viral strains, the combination of several therapies is a better choice. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Agricultural subsurface drainage is necessary for crop production in humid, poorly drained regions with frequent rainfall. Flooding and waterlogging have become more widespread and frequent in recent years, and effective measures should be adopted to increase the subsurface drainage capacity and alleviate flooding and waterlogging disasters after short-term heavy rainfall. However, subsurface drainage focused on the layout parameters (drain depth, drain spacing, etc.) in previous studies, and these measures were limited and cumbersome in the improvement of the flow rate of subsurface drainage. Thus, we aimed to alleviate the flooding and waterlogging threats to farmland and innovatively proposed a new method to increase the flow rate of subsurface drainage, namely siphon-type subsurface drainage. The paper evaluated the performance of the siphon-type subsurface drainage by the indoor sand tank test and the HYDRUS-2D model. Three factors were considered during the experiments: conventional and improved subsurface drainage; shallow, medium, and deep drain depth; and the outlet elevation, including the outlet elevation of the drain pipe under the non-siphon drainage and the outlet elevation of the siphon pipe under the siphon drainage. The results indicated that the siphon-type subsurface drainage performed better under the conditions of steady-state ponding and ponding subsided. The flow rate of the siphon-type subsurface drainage was 27.1–45.7%, 41.8–89.8%, and 39.3–50.5% higher than that of conventional, thin-improved, and thick-improved subsurface drainage with non-siphon drainage under steady-state ponding, respectively. It also had a significant advantage when the outlet elevation was the same. The siphon-type subsurface drainage could increase the flow rate during ponding subsided and reduce the flow rate attenuation degree before the ponding disappears. The flooding removal effect of the siphon-type subsurface drainage was significantly better than that of non-siphon subsurface drainage. The water head and flow rate were used to calibrate and validate the HYDRUS-2D model. The results indicated that the simulated values of flow rate matched well with the measured ones and the relative errors were less than 10%. The influence range and absolute values of the negative water head increased with the decrease of outlet elevation, and the increase effect of flow rate increased with the decrease of the water head. The siphon-type subsurface drainage has more control distance than the non-siphon. The advantages of siphon-type subsurface drainage are not only prominent in quart sand but also applicable to field soil. The results of this study could provide technical support for the application of flooding and waterlogging removal in areas where waterlogging is prone to occur and could improve the ability of agricultural production to address waterlogging disasters. • A siphon-type subsurface drainage to improve the subsurface drainage capacity is proposed. • The drainage rule of the siphon-type subsurface drainage is studied. • Effect of flooding and waterlogging removal of siphon-type subsurface drainage is revealed. • The flow rate attenuation degree of a siphon is assessed. • The performance of siphon-type subsurface drainage is validated by HYDRUS-2D model. [ABSTRACT FROM AUTHOR]

Background: Drug resistance in Helicobacter pylori severely affects the efficacy of eradication therapy, and a number of studies have been conducted on this issue. The aim of this study was to assess the progress in this field using a bibliometric approach. Materials and Methods: Publications related to H. pylori resistance from 2002 to 2022 were retrieved from the Web of Science database. Relevant information including titles, authors, countries, and keywords was extracted, and the data were processed using Excel, VOSviewer, and CiteSpace software for co‐authorship, co‐citation, and co‐occurrence analysis. Results: From 2002 to 2022 (as of 09/24/2022), the field of H. pylori–resistance research produced a total of 2677 publications with a total of 75217 citations, with an overall upward trend in the annual number of articles published, reaching a peak of 204 in 2019. Articles were mainly published in Q1 or Q2 journals, with Helicobacter (TP = 261) publishing the most literature, Baylor College of Medicine (TP = 68) and Deng‐chyang wu (TP = 38) being the most prolific institutions and authors, respectively. China and the United States were the locations of most of the articles, accounting for 35.08% of the global publication volume. Keyword co‐occurrence analysis divided H. pylori‐resistance research into four clusters: "Therapeutic Strategies," "Diseases," "Mechanism Research and Epidemiology," and "Drug Research." "Drug research" and burst detection indicate that the current research hotspot involves the selection and analysis of treatment strategies. Conclusions: H. pylori–resistance research has become a popular research field, and although there are significant contributions from Europe, the United States, and East Asia, there are significant imbalances between regions that cannot be ignored. In addition, the exploration of treatment strategies remains a key issue for research at the current stage. [ABSTRACT FROM AUTHOR]

Control of Bemisia tabaci has depended primarily and heavily on insecticides, especially neonicotinoids. The novel sulfoximine insecticide sulfoxaflor exhibits high potency against a broad range of sap-feeding insect species, including those resistant to neonicotinoids. The resistance levels of Q-biotype B. tabaci field strains collected from 8 locations in eastern China to neonicotinoids and sulfoxaflor were investigated, and single nucleotide polymorphisms (SNPs) of nicotinic acetylcholine receptor β1 subunit gene ( Btβ1 ) were detected. Compared with the reference strain, the field strains had developed low to moderate levels of resistance to imidacloprid and nitenpyram with the resistance ratios (RR) ranging between 4.07 and 21.75-fold and 3.37 and 16.14-fold, respectively. While YZ strain exhibited high resistance (RF 40.38) to thiamethoxam, only low levels of resistance to thiamethoxam (RF 3.50–8.58) was observed in other strains. All strains were relatively susceptible to both dinotefuran (RF 0.50–2.55) and sulfoxaflor (RF 0.40–3.07). Sequence analysis of Btβ1 cDNA fragments revealed 23 SNPs representing 19 amino acid replacements in these strains. Notably, a 45 bp fragment deletion was detected in JY strain, which encodes 15 amino acid residues (positions 66–80) containing arginine at position 79 (R79) corresponding to the R81T mutation in Loop D of nAChR β1 subunit in Myzus persicae resistant to neonicotinoids. The lack of cross-resistance indicates that both dinotefuran and sulfoxaflor could play an important role in the control of B. tabaci already resistant to the first and second generation neonicotinoids. [ABSTRACT FROM AUTHOR]

Based on a multi-scale view, in this paper, we study an age-structured within-host model with Crowley-Martin functional response for the control of viral infections. By means of semigroup and Lyapunov function, the global asymptotical property of infected steady state of the model is obtained. The results show that when the basic reproductive number falls below unity, the infection dies out. However, when the basic reproductive number exceeds unity, there exists a unique positive equilibrium which is globally asymptotically stable. This model can be deduced to different viral models with or without time delay. [ABSTRACT FROM AUTHOR]

An improved subsurface drainage with characteristics of less land occupied and reasonable flow rate drained was presented to overcome the disadvantage of small flow rate of conventional subsurface pipe drainage and adapt to the new challenge of agricultural drainage. Based on soil column experiment, the performance of improved subsurface drainage was discussed in saturated and unsaturated soil. During the experiment, five factors of filter width, soil medium, surface ponding depth, outflow condition and groundwater depth were considered. Then, drainage equation for improved subsurface drainage flow rate under conditions of surface ponding and homogeneous saturated soil was first proposed. The results indicated that improved subsurface drainage performed better in both saturated and unsaturated soil with surface ponding. Flow rates of improved subsurface drainage equaled to 2–3 times of that in conventional subsurface pipe drainage when filter width varied from 2 cm to 6 cm in completely saturated fine-sand medium. In addition, the greater the hydraulic conductivity gaps between filter and soil in a specific range, the more effective the improved subsurface drainage is. Besides, in case of large groundwater depth, improved subsurface drainage was still effective. When groundwater depth was 2 times of drain depth, improved subsurface drainage flow rate was comparable to 2 times of that in conventional subsurface pipe drainage in saturated fine-sand medium. The calculated flow rates matched well with the observed ones. The research results can provide technical support to the application of improved subsurface drainage. Meanwhile, it will be beneficial to enrich agricultural drainage technologies in China, which is of practical significance to ensure food safety and promote sustainable development of irrigated areas. [ABSTRACT FROM AUTHOR]

In this paper, we analyze a few opinion formation or election game dynamics models. For a simple model with two subpopulations with opposing opinions A and B , if the fraction of committed believers of opinion A (“ A zealots”) is less than a critical value, then the system has two bistable equilibrium points. When the fraction is equal to the critical value, the system undergoes a saddle-node bifurcation. When the fraction is larger than the critical value, a boundary equilibrium point is globally asymptotically stable, suggesting that the entire population reaches a consensus on A . We find a similar bistability property in the model in which both opinions have their own zealots. We also extend the model to include multiple competitors and show the dynamical behavior of multistability. The more competitors subpopulation A has, the fewer zealots opinion A needs to obtain consensus. [ABSTRACT FROM AUTHOR]

In this paper, we are concerned with the Cauchy problem to the multi-dimensional ( $N\geq4$) chemotaxis model. We prove the optimal convergence rates of the strong solutions to the system for initial data close to a stable equilibrium state in critical Besov spaces. Our main ideas are based on the low-high frequency decomposition and the smooth effect of dissipative operator. [ABSTRACT FROM AUTHOR]

Background: Hepatitis C virus (HCV) can be transmitted by blood transfusion. The aim of this meta‐analysis is to estimate the anti‐HCV reactive rate and to define the demographic characteristics of blood donors who have potential threats to blood safety in mainland China for nearly 30 years, in order to provide a safe reference for blood transfusion and corresponding guidance for policymakers to increase blood safety. Materials and Methods: Literature reporting the anti‐HCV screening reactive rate in Chinese blood donors was identified by systematic searching of four electronic databases from 1991 to 2017. The Preferred Reporting of Items for Systematic Reviews and Meta‐Analyses guidelines were strictly followed, and data manipulation and statistical analysis were performed by Stata 15.0. Results: Our results showed that the post‐donation anti‐HCV reactive rate was 0.53% (95% confidence interval [CI], 0.51%–0.55%) with a significant variation from 1.58% (95% CI, 1.13%–2.03%) before 1998 to 0.51% (95% CI, 0.48%–0.53%) after 1998 when the Blood Donation Law was implemented in China. In addition, anti‐HCV screening reactive rate for family or replacement donors was significantly higher than that in individual voluntary blood donors. Conclusion: Our results indicated that blood centres in China should convert more eligible first‐time donors into repeat donors and turn the 'real family or replacement donors' into individual voluntary blood donors to reduce the risk of transfusion‐transmitted HCV. In the meantime, large surveys should be carried out among volunteer donors from high‐risk populations. [ABSTRACT FROM AUTHOR]

Bifenthrin is a broad-spectrum insecticide and acaricide that is widely used in China. We evaluated the effects of sublethal concentrations (LC10 and LC25) of bifenthrin on the eggs and adult females of the two-spotted spider mite, Tetranychus urticae, in the laboratory at 26±1°C, 80% RH, and a 16 h: 8 h (L: D) photoperiod. The sublethal doses of bifenthrin decreased the intrinsic and finite rate of increase, net reproductive rate, survival rate, and reproductive value. The sublethal doses also increased the mean generation time, total pre-ovipositional period, and duration of the larval and nymphal stages. The intrinsic rate of increase dropped from 0.252/day in the control to 0.222 and 0.208/day in response to LC10 and LC25 treatments, respectively. Following LC10 and LC25 treatments, the net reproductive rate dropped from 60.65 offspring/individual in the control to 45.19 and 40.81, respectively. These laboratory results indicate that sublethal concentrations of bifenthrin may decrease the developmental rate of T. urticae, are unlikely to result in the resurgence of T. urtciae populations, and might therefore be useful in the integrated management of this pest. [ABSTRACT FROM AUTHOR]

A series of 2-(1-(2,4-bis((di(4-fluorophenyl)methyl)-6-methylphenylimino)ethyl)-6-(1-(aryl­imino)ethyl)pyridines is synthesized and used to form their corresponding iron(II) and cobalt(II) chloride complexes thereof. All the organic compounds are fully characterized by elemental analysis, and IR and 1H/13C NMR spectroscopy, whereas the corresponding iron and cobalt complexes are characterized by elemental analysis and IR spectroscopy, as well as single-crystal crystallography for the Fe2, Co1, and Co2 complexes, revealing a distorted trigonal bipyramidal structure. Upon activation with either methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), all the iron complexes exhibit high activities toward ethylene polymerization at 60 °C; meanwhile, all the cobalt analogs demonstrate slightly lower activities at the optimized temperatures of 60 °C (MAO as cocatalyst) or 70 °C (MMAO as cocatalyst). All the polyethylenes obtained from cobalt precatalysts possess narrow polydispersity and lower molecular weights than those from their iron analogs. [ABSTRACT FROM AUTHOR]

Abstract: Recent progress on nickel-based complex pre-catalysts is reviewed herein. The ethylene oligo-/polymerization behaviour is discussed in terms of the variation of the complex models bearing different kinds of ligand sets. These discussions focus mainly on the influence that the different substituents present have on the observed catalytic activity, the results of which can guide the design of new target structures possessing high ethylene activity. [Copyright &y& Elsevier]

Abstract: Soil salinization has random characteristics because of the influences of natural and anthropogenic factors. Therefore, a study on the dynamic prediction model of soil salinity is important for irrigation water management in salinization irrigation districts. In the present paper, the theory of supporting vector machine was introduced in the dynamic prediction of soil electrical conductivity (EC) values. Based on groundwater depth, irrigation water volume, and evaporation data from 1991 to 2010 in the Shahaoqu subdistrict of the Hetao irrigation district in Inner Mongolia, a dynamic prediction model of soil EC value was developed. The results show that the fitted values, tested values and the predicted values of the model have little difference from the real values. The absolute value of the fitting mean relative error is 2.14%, that of the testing mean relative error is 3.48%, and that of the predicting mean relative error is 6.37%. Compared with the Artificial Neural Network (ANN) model, the results show that SVM predictors perform better in forecasting soil EC values than the ANN model. The feasibility of the application of SVMs to soil salinity forecasting was demonstrated and their performance in soil salinity data analysis was proven. [Copyright &y& Elsevier]

A series of 2-[1-(4,6-dimethyl-2-benzhydrylphenylimino)ethyl]-6-[1-(arylimino)ethyl]pyridines was synthesized and used to prepare the iron(ii) and cobalt(ii) chloride complexes thereof. All organic compounds were fully characterized by elemental analysis, IR and NMR (1H/13C) spectroscopy, whilst the metal complexes were characterized by elemental analysis and IR spectroscopy as well as by single-crystal X-ray diffraction studies (for two representative cobalt complexes), which revealed that the geometry at the metal was either pseudo-square-pyramidal or trigonal bipyramidal. Upon activation with either methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), all metal complex pre-catalysts exhibited high activities for ethylene polymerization. The iron pre-catalysts show much higher activity than did their cobalt analogues; however, the iron catalytic systems generally produced polyethylene of wide molecular weight polydispersity. At elevated reaction temperature, the polyethylene was of lower molecular weight, but revealed narrow polydispersity. [ABSTRACT FROM AUTHOR]

Abstract: A series of 2-(1-{2,6-bis[bis(4-fluorophenyl)methyl]-4-methylphenyl-imino}ethyl)-6-[1-(arylimino)ethyl]pyridylcobalt(II) chloride complexes (Co1–Co5) was synthesized and characterized by FT-IR spectroscopy and elemental analysis. The molecular structures of the representative cobalt complexes Co1 (R1 = Me, R2 = H), Co4 (R1 = Me, R2 = Me) and Co5 (R1 = Et, R2 = Me) were determined by single crystal X-ray diffraction, and revealed a pseudo-square-pyramidal geometry at cobalt. Upon activation with either MMAO or MAO, all cobalt complex pre-catalysts exhibited high activities [up to the range of 107 g of PE (mol of Co)−1 h−1] toward ethylene polymerization. The influence of reaction parameters and the nature of the ligands were investigated in detail on the catalytic activities of the corresponding complexes and properties of the resultant polyethylene. The cobalt system revealed single-site behavior and produced polyethylene with narrow molecular distribution. Compared to the use of MAO, the use of MMAO produced polyethylene of higher molecular weight. [Copyright &y& Elsevier]

Abstract: In this paper, the dynamical behavior of a delayed viral infection model with immune impairment is studied. It is shown that if the basic reproductive number of the virus is less than one, then the uninfected equilibrium is globally asymptotically stable for both ODE and DDE model. And the effect of time delay on stabilities of the equilibria of the DDE model has been studied. By theoretical analysis and numerical simulations, we show that the immune impairment rate has no effect on the stability of the ODE model, while it has a dramatic effect on the infected equilibrium of the DDE model. [Copyright &y& Elsevier]

In this paper, we link the depth-based weighted empirical likelihood (WEL) with general estimating equations to produce a robust estimation of parameters for contaminated data with auxiliary information about the parameters. Such auxiliary information can be expressed through a group of functionally independent general estimating equations. Under general conditions, asymptotic properties of the WEL estimator are established. Furthermore, we prove that the WEL ratio statistic is asymptotically chi-squared distributed. Simulation studies are conducted to test the robustness of the WEL estimator. Finally, we apply the proposed method to analyse the gilgai survey data. [ABSTRACT FROM AUTHOR]

Abstract: A class of more general delayed viral infection model with lytic immune response is proposed based on some important biological meanings. The effect of time delay on stabilities of the equilibria is given. The sufficient criteria for local and global asymptotic stabilities of the viral free equilibrium and the local asymptotic stabilities of the no-immune response equilibrium are given. We also get the sufficient criteria for stability switch of the positive equilibrium. Numerical simulations are carried out to explain the mathematical conclusions. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we obtain the strong consistency and asymptotic distribution of the Theil–Sen estimator in simple linear regression models with arbitrary error distributions. We show that the Theil–Sen estimator is super-efficient when the error distribution is discontinuous and that its asymptotic distribution may or may not be normal when the error distribution is continuous. We give an example in which the Theil–Sen estimator is not asymptotically normal. A small simulation study is conducted to confirm the super-efficiency and the non-normality of the asymptotic distribution. [Copyright &y& Elsevier]

Abstract: The Methoprene-tolerant (Met) gene of Drosophila melanogaster is involved in both juvenile hormone (JH) action and resistance to JH insecticides, such as methoprene. Although the consequences of Met mutations on development and methoprene resistance are known, no studies have examined Met + overexpression. Met + was overexpressed in transgenic lines with various promoters that drive overexpression to different levels. Flies expressing either genomic or cDNA Met + transgenes showed higher susceptibility to both the morphogenetic and toxic effects of methoprene, consistent with the hormone-binding property of MET. Both the sensitive period and lethal period were the same as seen for non-overexpressing Met + flies. However, continual exposure of high-overexpressing Met + larvae to borderline-toxic or higher methoprene doses advanced the sensitive period from prepupae to first instar and the lethal period from pharate adults to larvae and early pupae. When expression of transgenic UAS-Met + was driven to high levels by either an actin-GAL4 or tubulin-GAL4 promoter, larvae showed high mortality in the absence of methoprene, indicating that high MET titer is lethal, perhaps resulting from expression in an inappropriate tissue. Adults overexpressing Met + did not show enhanced oogenesis, ruling out MET as a limiting factor for this hormone-driven physiology. [Copyright &y& Elsevier]

Abstract: The Methoprene-tolerant (Met) gene in Drosophila melanogaster has been shown to function in juvenile hormone (JH) action. Met homologs were isolated from three mosquito species, Culex pipiens, Aedes aegypti and Anopheles gambiae. Sequence similarity was found to be high in bHLH and PAS conserved domains, and the majority of the 7–9 introns in AaMet and AgMet are located in either identical or similar positions, indicating evolutionary relatedness. Sequence comparison with Met and the similar germ-cell expressed (gce) gene in D. melanogaster showed that the mosquito genes are more similar to gce than to Met. Moreover, the multiple introns in AgMet and AaMet are more similar in number with the 7 introns in Dmgce than to the single intron in DmMet; in fact, six intron positions in AaMet and AgMet are similar to those in Dmgce. Efforts to identify a second homologous gene in mosquitoes were unsuccessful, suggesting a single gene in lower Diptera, consistent with the single gene uncovered in genomic sequencing of Ae. aegypti and An. gambiae. These results suggest that a gene duplication occurred during the evolution of higher Diptera, resulting in Met and gce. [Copyright &y& Elsevier]

Abstract: Freezing and thawing cycles in soil can have a significant effect on field hydrology, which, in turn, can have a major influence on the fate and transport of agricultural chemicals. This study was conducted to evaluate the hydrological performance and NO3 −-N movement of the DRAINMOD 5.1 model with respect to freezing/thawing conditions. Measurements made in the years 1999 and 2000 at an experimental site in Truro, Nova Scotia, Canada on four test plots receiving inorganic fertilizer were used to test the model. Monthly subsurface drainage outflows, simulated using the original and DRAINMOD 5.1, were compared with the observed values. The results showed that the original DRAINMOD overestimated drain outflows during the colder months. The average difference between the monthly drainage outflows, simulated with DRAINMOD 5.1, and the observed values ranged from −0.35 to −1.42mm. Since the new model predicted the timing and magnitude of drainage events quite well and also did a much better job of simulating the hydrology of a colder region, as compared to the original model, it was used to simulate fate and transport of nitrogen compounds. The model was calibrated with the data from two test plots, and validated with the data from the remaining two plots. The difference between the simulated and observed total NO3 −-N losses over a period of 2 years were, respectively, 1.32 and 1.40kgN/ha for the calibration plots. For validation plots, they were −1.64 and 0.97kgN/ha, respectively. These results indicate that the DRAINMOD 5.1 model, performed satisfactorily, and may be used to estimate NO3 −-N losses through drainage outflow in colder regions. [Copyright &y& Elsevier]

Abstract: The Methoprene-tolerant (Met) bHLH-PAS gene is involved in juvenile hormone (JH) action in Drosophila melanogaster as a likely component of a JH receptor. We expressed Met in Drosophila S2 cells and explored for MET partners using pull-down assays. MET-MET interaction was found to occur. The germ-cell expressed (gce) gene is another D. melanogaster bHLH-PAS gene with high homology to Met, and GCE formed heterodimers with MET. In the presence of JH or either of two JH agonists, MET-MET and MET-GCE formation was drastically reduced. Interaction between GCE and MET having N- or C-terminus truncations, bHLH or PAS-A domain deletions, or a point mutation in the PAS-B domain failed to occur. However, JH-dependent interaction occurred between GCE and MET having point mutations in bHLH or PAS-A. During development, changes in JH titer may alter partner binding by MET and result in different gene expression patterns. [Copyright &y& Elsevier]

Application of chemical pesticides is currently the main effective method to control tobacco whitefly (Bemisa tabaci) in tomato in China. The B. tabaci control efficacy of three systemic insecticides (thiamethoxam, sulfoxaflor and cyantraniliprole) by pre-transplant soil drenching with anti-insect nets throughout the tomato growth period was evaluated in two tomato greenhouses in the suburbs of Beijing, China, in 2018 and 2019. In two greenhouse trials, thiamethoxam 25% water dispersible granules (WDG) at a field rate of 21 g a.i./hm2, sulfoxaflor 22% aqueous suspension (AS) at 18 g a.i./hm2 or cyantraniliprole 10% oil-based suspension concentrate (OD) at 18 g a.i./hm2 applied via soil drenching before seedling transplanting in combination with white anti-insect nets (50 mesh) all effectively controlled the damage to B. tabaci and resulted in a low density of adults and eggs during the entire growing season, which was significantly lower than application of thiamethoxam, sulfoxaflor or cyantraniliprole via soil drenching before seedling transplanting without anti-insect net treatments or anti-insect nets alone (P < 0.05). All of the above treatments provided significantly better results than the untreated control (P < 0.05). All chemically treated tomato fruits had acceptable insecticide residuals that were lower than the corresponding maximum residue limits. The results suggest that application of thiamethoxam 25% WDG at a field rate of 21 g a.i./hm2, sulfoxaflor 22% AS at 18 g a.i./hm2 or cyantraniliprole 10% OD at 18 g a.i./hm2 by pre-transplant soil drenching combined with anti-insect nets could be recommended to control B. tabaci throughout the tomato growth period as part of integrated pest management programs in China. [ABSTRACT FROM AUTHOR]

This study proposes an optimisation approach to improve multiple-criteria aspiration-level public transportation performance by combining public transport criteria matrix analytic hierarchy process (PTCM-AHP) models and multi-aspiration-level goal programming. The approach uses the PTCM-AHP to calculate the system weights. Based on the weight values, the approach combines the multi-aspiration goal-level selection process in three different ways. The proposed approach was used to optimise public transportation networks in Bayswater, Cockburn, and Stonnington, Australia, to demonstrate the public transportation network performance optimisation process. By controlling the criteria goal value interval, this new approach combines decision-making plans and strategies to optimise various scenarios. The optimisation outcomes can be applied to provide guidelines for improving the performance of public transportation networks. [ABSTRACT FROM AUTHOR]

For sufficient smooth nearly integrable Hamiltonian systems, an open dense set of perturbations has been constructed. And for a perturbation in this set the existence for families of lower-dimensional tori of hyperbolic, elliptic and mixed types has been proved. [ABSTRACT FROM AUTHOR]

Abstract: The Ca2BO3Cl:Eu2+ phosphor was synthesized by the general high temperature solid-state reaction and an efficient yellow emission under near-ultraviolet and blue excitation was observed. The emission spectrum shows a single intense broad emission band centered at 573 nm, which corresponds to the allowed f–d transition of Eu2+. The excitation spectrum is very broad extending from 350 to 500 nm, which is coupled well with the emission of UV LED (350–410 nm) and blue LED (450–470 nm). The measured emission of In–GaN-based Ca2BO3Cl:Eu2+ LED shows white light to the naked eye with a chromatic coordinate of (0.33, 0.36). The Ca2BO3Cl:Eu2+ is a very appropriate yellow-emitting phosphor for white LEDs. [Copyright &y& Elsevier]

Polyunsaturated fatty acids (PUFAs) are essential nutrients for all living organisms. PUFA synthesis is mediated by Δ12 desaturases in plants and microorganisms, whereas animals usually obtain PUFAs through their diet. The whitefly Bemisia tabaci is an extremely polyphagous agricultural pest that feeds on phloem sap of many plants that do not always provide them with sufficient PUFAs. Here, a plant‐derived Δ12 desaturase gene family BtFAD2 is characterized in B. tabaci and it shows that the BtFAD2‐9 gene enables the pest to synthesize PUFAs, thereby significantly enhancing its fecundity. The role of BtFAD2‐9 in reproduction is further confirmed by transferring the gene to Drosophila melanogaster, which also increases the fruit fly's reproduction. These findings reveal an extraordinary evolutionary scenario whereby a phytophagous insect acquired a family of plant genes that enables it to synthesize essential nutrients, thereby lessening its nutritional dependency and allowing it to feed and reproduce on many host plants. [ABSTRACT FROM AUTHOR]