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Abstract Here, we present the whole genome sequence of Bt S2160-1, a potential alternative to the mosquitocidal model strain, Bti. One chromosome genome and four mega-plasmids were contained in Bt S2160-1, and 13 predicted genes encoding predicted insecticidal crystal proteins were identified clustered on one plasmid pS2160-1p2 containing two pathogenic islands (PAIs) designed as PAI-1 (Cry54Ba, Cry30Ea4, Cry69Aa-like, Cry50Ba2-like, Cry4Ca1-like, Cry30Ga2, Cry71Aa-like, Cry72Aa-like, Cry70Aa-like, Cyt1Da2-like and Vpb4C1-like) and PAI-2 (Cyt1Aa-like, and Tpp80Aa1-like). The clusters appear to represent mosquitocidal toxin islands similar to pathogenicity islands. Transcription/translation of 10 of the 13 predicted genes was confirmed by whole-proteome analysis using LTQ-Orbitrap LC–MS/MS. In summary, the present study identified the existence of a mosquitocidal toxin island in Bacillus thuringiensis, and provides important genomic information for understanding the insecticidal mechanism of B. thuringiensis.

Accurately determining the attitude of non-cooperative spacecraft in on-orbit servicing (OOS) has posed a challenge in recent years. In point cloud-based spatial non-cooperative target attitude estimation schemes, high-precision point clouds, which are more robust to noise, can offer more accurate data input for three-dimensional registration. To enhance registration accuracy, we propose a noise filtering method based on moving least squares microplane projection (mpp-MLS). This method retains salient target feature points while eliminating redundant points, thereby enhancing registration accuracy. Higher accuracy in point clouds enables a more precise estimation of spatial target attitudes. For coarse registration, we employed the Random Sampling Consistency (RANSAC) algorithm to enhance accuracy and alleviate the adverse effects of point cloud mismatches. For fine registration, the J-ICP algorithm was utilized to estimate pose transformations and minimize spacecraft cumulative pose estimation errors during movement transformations. Semi-physical experimental results indicate that the proposed attitude parameter measurement method outperformed the classic ICP registration method. It yielded maximum translation and rotation errors of less than 1.57 mm and 0.071°, respectively, and reduced maximum translation and rotation errors by 56% and 65%, respectively, thereby significantly enhancing the attitude estimation accuracy of non-cooperative targets.

IntroductionThe emergence of multidrug-resistant (MDR) strains of Salmonella, which is a genus of important zoonotic pathogens, has aroused great public health concern worldwide.MethodsIn this study, 167 strains of Salmonella were isolated from 947 samples from broiler farms, slaughterhouses, and markets in Shandong Province. Antibiotic sensitivity testing was performed, and 70 strains of Salmonella were screened out by whole-genome sequencing (WGS) to evaluate serotypes, antimicrobial resistance genes (ARGs), the prevalence of class 1 integrons, the plasmid carriage rate, and phylogenetic characteristics and for multilocus sequence typing (MLST).ResultsThe results showed that the 167 isolates showed the highest resistance to ampicillin (AMP, 87.4%), sulfamethoxazole (SF, 87.4%), compound sulfamethoxazole (SXT, 81.4%), nalidixic acid (NAL, 80.2%), and amoxicillin/clavulanic acid (A/C, 77.8%). All the strains were sensitive to meropenem (MEM), and 91.0% of the isolates were MDR strains. We screened a total of 45 ARGs, with the highest detection rate observed for the tetracycline (TET) resistance gene tet (A) (81.4%). A total of 21 types of plasmid replicons were detected in Salmonella, of which IncX1 was the most common (74.3%), and 62.9% of the isolates carried a class 1 integron. In addition, a total of 11 different serotypes were detected, with S. enteritidis as the predominant serovar., followed by S. infantis and S. Newport. Twelve different sequence types (STs) were detected, among which ST11 was the main type. There was a strong correspondence between serotypes and STs. We also found that S. Indiana and S. Kentucky had extremely high rates of resistance to ciprofloxacin (CIP) and third-generation cephalosporins. System-wide genome analysis showed the occurrence of long-distance transmission across fields.ConclusionIn conclusion, the detection of multidrug resistance and isolates carrying multidrug resistance genes is the main problem, and emergency strategies should be implemented to address this issue.

Abstract Background Cyproflanilide is a novel chemical that is already undergoing insecticide registration in China and has been categorized as a member of group 30 by the IRAC. Since it was first detected in 2019, the fall armyworm (FAW), Spodoptera frugiperda, has become a serious pest in China. Our laboratory and field efficacy trials indicated that cyproflanilide exhibits high larvicidal activity against FAW. However, the effect of cyproflanilide against FAW remains unknown. And it is worth exploring further before the cyproflanilide becomes commercially available. Results We found larvae exposed to cyproflanilide had significantly shorter body length and higher death rates compared to control larvae. Additionally, we found surviving larvae had a significantly longer developmental period compared to control larvae. The potential molecular mechanisms of cyproflanilide against FAW were investigated using comparative transcriptomic analyses on larval samples subjected to three insecticide treatments, including cyproflanilide and two other commonly used insecticides against FAW in China, chlorantraniliprole and avermectin. We found that several subunits of the γ-aminobutyric acid receptor (GABAR), a possible target protein of cyproflanilide, were significantly up-regulated at the transcriptional level during cyproflanilide-induced stress. Additionally, between the control and cyproflanilide-treated samples, we identified 131 differentially expressed genes (DEGs) associated with detoxification metabolism. Of these, we found four P450 genes that were significantly up-regulated under cyproflanilide stress but were not DEGs when exposed to chlorantraniliprole and avermectin, or 23 other pesticides from previous reports. Furthermore, we discovered an interesting gene aggregation region for insect cuticle proteins (CPs) on the 18th chromosome, which is likely related to FAW cross-resistance to cyproflanilide and avermectin. Conclusions Our results contribute to a greater understanding of the mechanisms by which cyproflanilide affects FAW. Additionally, we identified the similarities and differences in transcriptomic profiling of FAW between the novel insecticide cyproflanilide and two other commonly used insecticides.

The construction of efficient electrocatalysts is key in harnessing the electrochemical CO2 reduction reaction (CRR) to produce high-value chemicals. Herein, a typical bacterium containing metal–nitrogen (M−N) groups and with a rich phosphorus content, Shewanella oneidensis MR-1, was used as a single precursor to produce atomically dispersed iron–nitrogen–phosphorus active sites (P–Fe/NC-1000) for converting CO2 to CO. Excellent CO selectivity of nearly 100% at 390 mV overpotential was achieved with good stability, and a rechargeable Zn–CO2 battery provides a maximum power density of 1.32 mW cm−2. Kinetic isotope effect measurements revealed that the presence of P atoms accelerates water dissociation and transfers a proton to Fe centers to promote protonation of intermediates and the overall CRR process. This synthesis strategy based on the intrinsic structure of a precursor may inspire the development of other high-performance catalysts for diverse electrochemical reactions beyond the CRR .

The distribution of nutrients in sediments is the result of multiple factors, including hydrological conditions and vegetation regulation, and in wetlands with complex hydrological conditions, this distribution is uncertain. In this study, the spatial distribution patterns of nitrogen and phosphorus in sediments were studied in the riverside and lakeside wetlands of Dongting Lake, a typical river-connected lake. The results showed that the nitrogen and phosphorus concentrations in the surface sediments were higher than those in the subsurface sediments in both the riverside and lakeside wetlands. In addition, the concentration of total nitrogen (TN) of lakeside wetlands in the surface sediments was higher than that of riverside wetlands, whereas the concentration of total phosphorus (TP) did not differ between the two wetland types. In the surface sediments, there were significant positive correlations between the TN and TP concentrations in the riverside wetlands ( p < 0.05), but no significant correlation in the lakeside wetlands ( p > 0.05). In riverside wetlands, the nitrogen and phosphorus concentrations showed strong spatial dependence. However, in the lakeside wetlands, the spatial dependence of NO _3 ^− -N was strong, that of NH _4 ^+ -N was moderate, and that of TN and TP was weak. This study shows that both hydrology and vegetation cause differences in the distribution of nutrients in the sediments. The results obtained from this investigation clarify the differences of sediment nitrogen and phosphorus distributions in the two types of wetlands and provide a technical reference for the management of different wetland types.

A chromosome-level genome assembly for the rice pest, Chlorops oryzae, pinpoints molecular pathways that might contribute toward increased outbreaks for this important crop pest.

IntroductionUsing black soldier fly larvae (BSFLs) to treat food waste is one of the most promising environmental protection technologies.MethodsWe used high-throughput sequencing to study the effects of different nutritional compositions on the intestinal microbiota and digestive enzymes of BSF.ResultsCompared with standard feed (CK), high-protein feed (CAS), high-fat feed (OIL) and high-starch feed (STA) had different effects on the BSF intestinal microbiota. CAS significantly reduced the bacterial and fungal diversity in the BSF intestinal tract. At the genus level, CAS, OIL and STA decreased the Enterococcus abundance compared with CK, CAS increased the Lysinibacillus abundance, and OIL increased the Klebsiella, Acinetobacter and Bacillus abundances. Diutina, Issatchenkia and Candida were the dominant fungal genera in the BSFL gut. The relative abundance of Diutina in the CAS group was the highest, and that of Issatchenkia and Candida in the OIL group increased, while STA decreased the abundance of Diutina and increased that of Issatchenkia. The digestive enzyme activities differed among the four groups. The α-amylase, pepsin and lipase activities in the CK group were the highest, and those in the CAS group were the lowest or the second lowest. Correlation analysis of environmental factors showed a significant correlation between the intestinal microbiota composition and digestive enzyme activity, especially α-amylase activity, which was highly correlated with bacteria and fungi with high relative abundances. Moreover, the mortality rate of the CAS group was the highest, and that of the OIL group was the lowest.DiscussionIn summary, different nutritional compositions significantly affected the community structure of bacteria and fungi in the BSFL intestinal tract, affected digestive enzyme activity, and ultimately affected larval mortality. The high oil diet gave the best results in terms of growth, survival and intestinal microbiota diversity, although the digestive enzymes activities were not the highest.

It is critical to identify and evaluate efficient phosphate-solubilizing bacteria (PSB) that enable P uptake from unavailable forms, and therefore improve the phosphorus (P) uptake efficiency of crops. The Enterobacter cloacae strain NG-33, belonging to PSB, was isolated and identified from calcareous rhizosphere soils in Nonggang National Reserve, Guangxi, China. The stain NG-33 could reduce the pH of the medium to below 5.6, and had the ability to release soluble phosphorus (P; 180.7 μg ml−1) during the culture in the National Botanical Research Institute’s Phosphate medium (NBRIP), and produced such organic acids as gluconic acid (4,881 mg L−1), acetic acid (346 mg L−1), and indole-3-acetic acid (20.4 μg ml−1). It could also convert inorganic P in AlPO4 (Al-P) and FePO4 (Fe-P) into soluble P, with conversion efficiencies of 19.2 μg ml−1 and 16.3 μg ml−1, respectively. Under pot experiments and when compared controls without inoculating NG-33, the shoot and root biomass of maize seedlings showed increases by 140% for shoot biomass and by 97% for root biomass in loamy soil (P sufficient) inoculated with NG-33. In sandy soil (P deficit) supplemented with tricalcium phosphate and inoculated with NG-33, the soluble P content was significantly higher, 58.6% in soil and 33.6% in roots, meanwhile, the biomass of shoots and roots increased by 14.9 and 24.9%, respectively. The growth-promoting effects coupled to the significant increase in leaf net photosynthetic rate and stomatal conductance of plants grown in NG-33-inoculated soil. Inoculating NG-33 could significantly improve the diversity and richness of bacterial population and altered the dominant bacterial population in soil.

The bacteria contained in air aerosols from poultry houses are closely connected to animal health and production. This study aimed to investigate the seasonal factors on microbial aerosol concentration, particle size and bacterial spectrum composition inside a closed-cage broiler house. Then, 16S rDNA sequencing technology was applied to analyze the characteristics of bacterial abundance and diversity. The results indicated that the concentration of bacterial aerosol in the broiler house varied significantly in different seasons, with a concentration range of 5.87–15.77 × 103 CFU/m3, and the highest and lowest concentrations in the summer and winter, respectively. Microbiological analysis showed that the proportion of Gram-negative bacteria in autumn was significantly higher than that in summer (P < 0.05). In addition, the floral structure of potential pathogenic bacterial genera also differed by season. Escherichia-Shigella, Streptococcus, Acinetobacter, Pseudomonas were identified in the bacterial aerosols. Importantly, the relative abundance of Firmicutes in spring and autumn was much higher. In contrast, the relative abundance of Proteobacteria in spring and autumn was lower than that in summer and winter. Altogether, results revealed the effects of seasonal factors on the diversity and abundance of bacteria and the distribution characteristics of major opportunistic pathogens in the air of closed-cage broiler houses. These results will provide important information for exploring the potential risk of aerosols from poultry houses all four seasons.

Plant non-harvest changes element circulation and has a marked effect on element sinks in the ecosystem. In this study, a field investigation was conducted on the fixation of nitrogen and phosphorus in Miscanthus lutarioriparius, the most dominant plant species in the Dongting Lake wetlands. Further, to quantitatively compare the difference in nitrogen and phosphorus sinks between harvest and non-harvest, an in situ experiment on the release of the two elements from two types of litters (leaves and stems) was studied. The nitrogen concentrations in the plant had no significant relationship with the environmental parameters. The phosphorus concentrations were positively related to the plot elevation, soil organic matter, and soil total potassium and were negatively related to the soil moisture. The leaves demonstrated a higher decomposition coefficient than that of the stems in the in situ experiment. The half decomposition time was 0.61 years for leaves and 1.12 years for stems, and the complete decomposition time was 2.83 years for leaves and 4.95 years for stems. Except for the nitrogen concentration in the leaves, all the concentrations increased during the flood period. All concentrations unsteadily changed in the backwater period. Similarly, except for the relative release index of nitrogen in the leaves, all the relative release indices decreased in the flood period. At the end of the in situ decomposition experiment, the relative release indices of both the nitrogen and phosphors were greater than zero, indicating that there was a net release of nitrogen and phosphorus. Under the harvest scenario, the aboveground parts of the plant were harvested and moved from the wetlands, thus increasing the nitrogen and phosphorus sinks linearly over time. The fixed nitrogen and phosphorus in the aboveground parts were released under the non-harvest scenario, gradually accumulating the nitrogen and phosphorus sinks from the first year to the fifth year after non-harvest, reaching a maximum value after the fifth year. This study showed that the nitrogen and phosphorus sinks greatly decreased after the non-harvest of M. lutarioriparius compared to that after harvest. It is recommended to continue harvesting the plant for enhancing the capacity of element sinks.

Hong Kong International Airport (HKIA) is an important sea airdrome in China. The aim of this study is to evaluate the impacts of this reclamation on the water quality of the Northwestern Bay of Hong Kong (NWBHK). In all, 117 Landsat 5 TM and 44 Landsat 8 OLI images were preprocessed and matched with the marine water data of 18 in situ monitoring points, acquiring 458 and 119 sets of data, respectively. This study adopted BPNN Machine Learning methods to establish the retrieval algorithm. Based on the images, the construction of HKIA was divided into three stages: (1) the construction of the first and second runways from 1992 to 1995; (2) the construction of the Hong Kong Port from 2013 to 2016; and (3) the construction of the third runway from 2017 to 2020. The concentrations of suspended particulate matter, orthophosphate phosphorus, and dissolved inorganic nitrogen from 1986 to 2022 were retrieved. In this paper, it was found that (1) the construction activities led to an increase in SPM, PO4P, and DIN concentrations in adjacent water bodies; (2) the impact of the Tuen Mun River on the NWBHK increased, while the impact of the Tung Chung River on the NWBHK decreased; and (3) the interception impact of HKIA on the transportation of the Pearl River water became stronger.

Reconstructing chlorophyll-a (Chl-a) vertical profile is a promising approach for investigating the internal structure of marine ecosystem. Given that the process of profile classification in current process-oriented profile inversion methods are either too subjective or too complex, a novel Chl-a profile reconstruction method was proposed incorporating both a novel binary tree profile classification model and a profile inversion model in the Mediterranean Sea. The binary tree profile classification model was established based on a priori knowledge provided by clustering Chl-a profiles measured by BGC-Argo floats performed by the profile classification model (PCM), an advanced unsupervised machine learning clustering method. The profile inversion model contains the relationships between the shape-dependent parameters of the nonuniform Chl-a profile and the corresponding Chl-a surface concentration derived from satellite observations. According to quantitative evaluation, the proposed profile classification model reached an overall accuracy of 89%, and the mean absolute percent deviation (MAPD) of the proposed profile inversion model ranged from 12%–37% under different shape-dependent parameters. By generating monthly three dimensions Chl-a concentration from 2011 to 2018, the proposed process-oriented method exhibits great application potential in investigating the spatial and temporal characteristics of Chl-a profiles and even the water column total biomass throughout the Mediterranean Sea.

Cancer is the leading lethal disease worldwide. Natural products have contributed significantly to the development of approved therapeutic agents. Therefore, research into new bioactive naturally sourced metabolites with lead potential is urgently needed. It is well-known that marine microorganisms are by far one of the most notable and prolific sources of bioactive natural products. Among them, deep-sea-derived fungi are extraordinarily adapted and metabolically active under extreme environmental conditions, which enable them to produce a large number of novel secondary metabolites. Chemical examination of deep-sea-derived fungi has yielded enormous amounts of cytotoxic natural products and potential drug leads. This review summarizes a total of 229 cytotoxic compounds isolated from deep-sea-derived fungi from 2010 to 2021. The emphasis is on the unique chemical diversity of these metabolic products, together with their relevant cytotoxic properties. Among the isolated metabolites, 82 compounds have been found to possess moderate to potent cytotoxic activities. Meanwhile, we also highlight some compounds with potent cytotoxicities (namely “star molecules”) considering their high drug lead potential. This review reveals deep-sea-derived fungi as considerable resources for the development of new drugs and the potential of the newly discovered secondary metabolites as valuable antitumor lead compounds.

High concentrations of PM2.5 in enclosed broiler houses cause respiratory disorders in humans and animals. Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen that can induce severe respiratory disease in animals under stress or with abnormal immune functions. Alveolar macrophages are lung-resident immune cells that play important roles in lung host defence and immune balance. In this study, the mechanism by which PM2.5 synergizes with P. aeruginosa to damage alveolar macrophage function and induce inflammation was investigated. The results will provide a theoretical basis for improving the poultry breeding environment and preventing the recurrence of infection with P. aeruginosa. Alveolar macrophages were stimulated by PM2.5 collected in an enclosed broiler house and P. aeruginosa. Phagocytosis was determined by the neutral red test. The apoptosis rate and cytoskeleton changes were observed by flow cytometry assays and laser scanning confocal microscopy. Protein levels related to autophagy and the mTOR pathway were detected by Western blotting. The results indicated that PM2.5 in combination with P. aeruginosa could decrease phagocytosis, inhibit autophagy, increase apoptosis, and destroy the cytoskeleton in alveolar macrophages. In addition, alveolar macrophages had significantly increased expression of mTOR pathway-related proteins in response to the synergistic stimulation of PM2.5 and P. aeruginosa. The above results confirmed that PM2.5 in poultry houses synergized with P. aeruginosa to impede alveolar macrophage function and caused more severe respiratory system injuries through a process closely related to the activation of the mTOR signalling pathway.

Plant speciation in mountain systems is crucial for shaping plant biodiversity, particularly for those endemic species with small populations. The mountain-geobiodiversity hypothesis (MGH) is among the possible mechanisms underlying mountain biodiversity. To test the MGH, we selected three Rhododendron species occupying the Hengduan Mountains (HDM) as focal species and then genotyped 12 populations using Restriction-site Associated DNA sequencing (RAD-seq) to reveal their speciation and divergence history. We found that there was high interspecific differentiation, low gene flow, and a high genetic drift among three Rhododendron species, suggesting that founder effects might play a key role in their differentiation. Historical gene flow occurred from R. brachypodum to R. calophytum var. pauciflorum. The effective population size of three Rhododendron species declined about 1 Kya ago. Rhododendron brachypodum experienced a bottleneck event during the Last Glacial Maximum (15–20 Kya). Three Rhododendron species diverged between 15.5 Mya and 3.13 Mya, which might be associated with the uplift of the HDM. These findings suggest that the speciation of three Rhododendron may be partly attributable to geological processes and climate fluctuations, strongly supporting the MGH. Additionally, our results provide new insights into the speciation patterns of endemic species and the protection of narrow-ranged species in mountain systems.

Understanding the genetic structure and differentiation in endangered species is of significance in detecting their phylogenetic relationships and prioritizing conservation. Here we sampled five endangered Cycas species endemic to southwest China and genotyped genetic structure and differentiation among them using the genotyping-by-sequencing (GBS) method. C. hongheensis showed high genetic diversity, but the other four species showed low genetic diversity. The genetic diversity between wild and cultivated populations was similar for C. debaoensis and C. guizhouensis, respectively. Low genetic differentiation and high gene flow were found among C. debaoensis, C. guizhouensis, and C. fairylakea, and C. hongheensis differentiated from them at ~1.74 Mya. TreeMix results showed historic migration events from C. guizhouensis to C. hongheensis, showing southward migration pathways. C. hongheensis showed increased effective population size with time, while the other four species underwent bottleneck events at ~1–5 Mya when continuous cooling events occurred. Our results indicate that the migration, differentiation, and speciation of Cycas species are associated with historical cooling events.

DWARF17 (D17/HTD1) is a well-defined rice strigolactone (SL) biosynthesis gene that influences rice tiller development and the production of rice. To investigate whether SLs play a role in the regulation of rice’s defense against the white-backed planthopper (WBPH, Sogatella furcifera), we compared a SL-biosynthetic defective mutant (d17) with WT rice plants. Our olfactory bioassay results revealed that WBPHs are attracted to d17 plants, which may be attributed to changes in rice volatile substances. Hexanal, a volatile substance, was significantly reduced in the d17 plants, and it was demonstrated that it repelled WBPHs at a concentration of 100 μL/L. Compared to the WT plants, WBPH female adults preferred to oviposit on d17 plants, where the egg hatching rate was higher. The transcript level analysis of defense-associated genes in the JA and SA pathways showed that the expression of OsJAmyb, OsJAZ8, OsPR1a and OsWRKY62 were significantly reduced in d17 plants compared to WT plants following WBPH infection. These findings suggest that silencing the strigolactone biosynthesis gene D17 weakens defenses against S. furcifera in rice.

A medium-carbon low-alloy steel was prepared via the asymmetric rolling process with different ratios of upper and down roll velocities. Subsequently, the microstructure and mechanical properties were explored by using SEM, EBSD, TEM, tensile tests and nanoindentation. The results show that asymmetrical rolling (ASR) can significantly improve strength while retaining good ductility compared with conventional symmetrical rolling. The yield strength and tensile strength of the ASR-steel are 1292 ± 10 MPa and 1357 ± 10 MPa, respectively, which are higher than the values of 1113 ± 10 MPa and 1185 ± 10 MPa for the SR-steel. The ASR-steel retains good ductility of 16.5 ± 0.5%. The significant increase in strength is related to the joint actions of the ultrafine grains, dense dislocations and a large number of nanosized precipitates. This is mainly because of the introduction of extra shear stress on the edge under asymmetric rolling, which induces gradient structural changes hence increasing the density of geometrically necessary dislocations.

Chilo suppressalis is one of the most damaging rice pests in China’s rice-growing regions. Chemical pesticides are the primary method for pest control; the excessive use of insecticides has resulted in pesticide resistance. C. suppressalis is highly susceptible to cyproflanilide, a novel pesticide with high efficacy. However, the acute toxicity and detoxification mechanisms remain unclear. We carried out a bioassay experiment with C. suppressalis larvae and found that the LD10, LD30 and LD50 of cyproflanilide for 3rd instar larvae was 1.7 ng/per larvae, 6.62 ng/per larvae and 16.92 ng/per larvae, respectively. Moreover, our field trial results showed that cyproflanilide had a 91.24% control efficiency against C. suppressalis. We investigated the effect of cyproflanilide (LD30) treatment on the transcriptome profiles of C. suppressalis larvae and found that 483 genes were up-regulated and 305 genes were down-regulated in response to cyproflanilide exposure, with significantly higher CYP4G90 and CYP4AU10 expression in the treatment group. The RNA interference knockdown of CYP4G90 and CYP4AU10 increased mortality by 20% and 18%, respectively, compared to the control. Our results indicate that cyproflanilide has effective insecticidal toxicological activity, and that the CYP4G90 and CYP4AU10 genes are involved in detoxification metabolism. These findings provide an insight into the toxicological basis of cyproflanilide and the means to develop efficient resistance management tools for C. suppressalis.

Salmonella is a major zoonotic foodborne pathogen that persists on poultry farms worldwide. The present study aimed to survey the prevalence of Salmonella and antimicrobial resistance of Salmonella enterica serovar Enteritidis (S. Enteritidis) recovered from broiler chickens in Shandong Province, China. A total of 280 Salmonella isolates were identified from 923 broiler chicken samples between 2013 and 2018. Among the isolates, S. Enteritidis (n = 128, 45.7%) was the predominant serovar, and high antimicrobial resistance rates to piperacillin (PIP) (n = 123, 96.1%), ampicillin (AM) (n = 122, 95.3%), nitrofurantoin (FT) (n = 106, 96.1%), and tetracycline (TE) (n = 93, 72.7%) were observed in S. Enteritidis. A total of 96 (75.0%) S. Enteritidis isolates presented with multidrug resistance, the most frequent of which were the combination of AM, PIP, TE, and FT. Resistance to fluoroquinolone tended to increase during 2013 to 2018. Our findings provide important and updated information about the baseline antimicrobial-resistant data for food safety and a risk assessment of S. Enteritidis from broiler chickens in Shandong Province and will be helpful for future surveillance activities to ensure the safety of the chicken supply.

The distribution range of plants is usually related to their competitiveness. The competitive ability between common widespread, which are generally considered to be invasive, and common endemic species, is still not very clear. Five plant communities were monitored in the field to compare the competitive abilities of widespread species, Phragmites australis, and endemic species, Triarrhena lutarioriparia, in the Dongting Lake wetlands. The ratios of individual numbers of T. lutarioriparia to P. australis per square meter were found to be 9:0, 14:1, 10:5, 7:6, and 0:11 in the five respective communities. A manipulation experiment was then performed with five planting modes (T. lutarioriparia: P. australis was 4:0, 3:1, 2:2, 1:3, and 0:4, respectively). Results from field monitoring showed that the two plant species exhibited similar decreased survival percentages during flooding. P. australis had higher aboveground biomass before the flooding and a higher relative elongation rate, whereas T. lutarioriparia had higher aboveground biomass after flooding and a higher relative growth rate (RGR). P. australis had a higher competitive ability than T. lutarioriparia before and after the flooding. The manipulation experiment revealed that P. australis had a higher survival percentage than T. lutarioriparia, with no differences in plant biomass, RGR, and the relative elongation rate between the two species. P. australis was found to have a higher competitive ability than T. lutarioriparia in the early growing stage and a lower competitive ability in the middle and later stages. The relative yield total in the field monitoring and manipulation experiment was 1, indicating that T. lutarioriparia and P. australis occupied different niches in the experimental conditions. It was concluded that, compared with T. lutarioriparia, P. australis has a higher competitive ability in submerged habitats and a lower competitive ability in the non-submerged habitat. The niche differences between the two species enabled their coexistence in the Dongting Lake wetlands with seasonal flooding.

Abstract The currently spreading resistance of the malaria parasite Plasmodium falciparum to artemisinin‐based combination therapies makes an urgent need for new efficient drugs. Aiming to kill artemisinin‐resistant Plasmodium, a series of novel hybrid drugs named Atokels were synthesized and characterized. Atokels are based on an 8‐amino‐ or 8‐hydroxyquinoline entity covalently bound to a 1,4‐naphthoquinone through a polyamine linker. These drugs have been designed to target the parasite mitochondrion by their naphthoquinone moiety reminiscent of the antimalarial drug atovaquone, and to trigger a damaging oxidative stress due to their ability to chelate metal ions in order to generate redox active complexes in situ. The most effective Atokel drug shown a promising antimalarial activity (IC50=622 nm on an artemisinin‐resistant P. falciparum strain) and no cytotoxicity at 50 μm indicating a specific antiplasmodial mode of action.

Practical approaches for chemoselective mono-bromination, di-bromination, and tetra-bromination of terminal alkynes to generate 1-bromoalkynes, 1,2-dibromoalkenes, α,α-dibromoketones, and 1,1,2,2-tetrabromoalkanes based on efficient oxidative brominations mediated by a hypervalent iodine reagent have been developed. Chemoselective bromination can be realized under mild conditions by altering the bromine source. The tetrabutylammonium bromide (TBAB)/(diacetoxyiodo)benzene (PIDA) system is specific for mono-bromination to provide 1-bromoalkynes, while the NaBr/PIDA system is selective toward di-bromination to achieve 1,2-dibromoalkenes. When a certain amount of water was added to the NaBr/PIDA system, a different di-bromination product, α,α-dibromo ketones, was generated. Tetra-bromination of terminal alkynes provides an efficient protocol for the synthesis of 1,1,2,2-tetrabromoalkanes in a system with an excess loading of NaBr/PIDA in one pot. This bromination affords good yields (up to 99%) with excellent chemoselectivity (up to 100%). These methods can be applied to the efficient chemoselective synthesis of bromide derivatives, intermediates, and related biologically active compounds.

Lactobacillus plantarum can interact with macrophages against bacterial enteropathy due to its potential ability to modulate macrophage polarization. However, this mechanism is not completely understood. TLR2 can recognize microbial components and trigger macrophage cytokine responses to different gram-positive strains. The aim of this study was to investigate whether probiotic Lactobacillus plantarum RS-09 can induce macrophage polarization against Salmonella Typhimurium infection via TLR2 signalling. BALB/c mice were preadministered RS-09 continuously for 7 days and then infected with Salmonella Typhimurium ATCC14028. Mouse RAW264.7 mononuclear macrophages were stimulated with RS-09 and coincubated with ATCC14028 or PBS controls. The results of the in vivo study indicated that RS-09 could relieve S. Typhimurium-induced splenomegaly, body weight loss and death rate. RS-09 also limited the colonization and translocation of S. Typhimurium in the gastrointestinal tract and thereby protected against infection. We also observed that RS-09 upregulated the production of M1 macrophage characteristics (e.g., CD11c and IL-6) against S. Typhimurium. Furthermore, RS-09 induced the expression of TLR2 in macrophages. In an in vitro study, treatment of RAW264.7 cells with RS-09 either concurrently with or before S. Typhimurium challenge enhanced the secretion of Reactive oxygen species and Nitric oxide. This effect was related to TLR2 and NF-κB activation. Based on these findings, Lactobacillus plantarum RS-09 was shown to modulate M1 macrophage polarization and induce TLR2-linked NF-κB signalling activity in the innate immune response to S. Typhimurium infection.

BackgroundArma custos Fallou (Hemiptera: Asopinae) is an important predatory insect native to China, South Korea, and Mongolia. It is important to understand the evolution of egg cannibalism in A. custos to evaluate the biocontrol potential of this species. However, few reports have suggested egg cannibalism in A. custos, and whether hungry adult A. custos males and females prey on their eggs remains unknown. Here, we investigated the effects of the parental sex of A. custos adults on egg cannibalism of parental and non-parental eggs (kinship) under no-choice and free-choice conditions, along with the effects of predator and egg density on egg cannibalism under starvation conditions.ResultsFemales frequently visited and cannibalized a higher proportion of eggs, whereas males almost did not participate in egg cannibalism (less than 17% males showed egg cannibalism behavior). Moreover, regardless of their relationship with the egg, neither male nor female adults consumed all available eggs even in the absence of an alternative food source, and >70% of eggs remained unconsumed. In contrast, cannibalistic males and females did not discriminate between parental and non-parental egg types. Meanwhile, cannibalism rates were similar when adults were offered 30 eggs or more. However, when offered fewer than 30 eggs, cannibalism rates declined disproportionally, suggesting that limited egg availability reduced cannibalism. Additionally, the lifespan of A. custos adult females increased significantly with increasing number of consumed eggs (p < 0.05).ConclusionArma custos females exhibit a higher tendency for egg cannibalism than males. Neither male or female A. custos discriminated between parental and non-parental egg types. Cannibalism enhances survival in that a starved individual who predates on eggs survives similarly to a well-fed individual. These findings provide a model to study the evolution and biological significance of egg cannibalism in A. custos and also contribute to the efficient mass rearing and realization of A. custos for biological control.

The beneficial effects of the probiotic strain Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) are based on its adherence and colonization ability in the gut. However, little is known about the migration and long-term gut colonization of the strain. This study evaluated the gut colonization modes of Lactiplantibacillus plantarum RS-09 to identify the strain with long-term gut colonization potential. We established CFDA/SE-labeled RS-09 to study the temporal and spatial distribution of RS-09 in the intestine as well as to analyze its persistence in different parts of the intestine by flow cytometry. This study has shown that the RS-09 strain maintains strong adhesion abilities under acid (pH 2.5) and base (pH 8.5) conditions. In addition, CFDA/SE can be used as an indicator for the labeling of L. plantarum RS-09 in the intestinal tract in vivo. We established a growth kinetics model of RS-09 to elucidate its persistence in the intestine. In vivo persistence experiments showed that the persistence rate of RS-09 was the highest in the cecum (69.5%) and the lowest in the duodenum (12.8%) at 96 h. After 20 days, RS-09 was predominantly localized in the cecum and colon steadily. These studies provide new insights into the long-term persistence of L. plantarum in the gastrointestinal tract. The CFDA/SE label system may be used to study the in vivo colonization dynamics of other probiotic strains.

Abstract Background Chlorops oryzae is an important pest of rice crops. There have been frequent outbreaks of this pest in recent years and it has become the main rice pest in some regions. To elucidate the molecular mechanism of frequent C. oryzae outbreaks, we estimated the genetic diversity and genetic differentiation of 20 geographical populations based on a dataset of ISSR markers and COI sequences. Results ISSR data revealed a high level of genetic diversity among the 20 populations as measured by Shannon’s information index (I), Nei’s gene diversity (H), and the percentage of polymorphic bands (PPB). The mean coefficient of gene differentiation (Gst) was 0.0997, which indicates that only 9.97% genetic variation is between populations. The estimated gene flow (Nm) value was 4.5165, indicating a high level of gene flow and low, or medium, genetic differentiation among some populations. The results of a Mantel test revealed no significant correlation between genetic and geographic distance among populations, which means there is no evidence of significant genetic isolation by distance. An UPGMA (unweighted pair-group method with arithmetic averages) dendrogram based on genetic identity, did not indicate any major geographic structure for the 20 populations examined. mtDNA COI data indicates low nucleotide (0.0007) and haplotype diversity (0.36) in all populations. Fst values suggest that the 20 populations have low, or medium, levels of genetic differentiation. And the topology of a Neighbor-Joining tree suggests that there are no independent groups among the populations examined. Conclusions Our results suggest that C. oryzae populations have high genetic diversity at the species level. There is evidence of frequent gene flow and low, or medium, levels of genetic differentiation among some populations. There is no significant correlation between genetic and geographic distance among C. oryzae populations, and therefore no significant isolation by distance. All results are consistent with frequent gene exchange between populations, which could increase the genetic diversity, and hence, adaptability of C. oryzae, thereby promoting frequent outbreaks of this pest. Such knowledge may provide a scientific basis for predicting future outbreaks.

Fungal aerosols in broiler houses are important factors that can harm the health of human beings and broiler. To determine the composite characteristics and changes in fungal aerosols in broiler houses during different broiler growth stages in summer. We analyzed the species, concentration and particle diameter distribution characteristics of the aerosols in poultry houses using an Andersen sampler and internal transcribed spacer 1 (ITS1) high-throughput sequencing technology. The concentration of fungal aerosols in the poultry houses increased as the ages of the broiler increased, which was also accompanied by gradual increases in the variety and diversity indices of the fungal communities in the air of the poultry houses. During the entire broiler growth period, the dominant genera in the fungal aerosols in the poultry houses included Trichosporon, Candida, Aspergillus, Cladosporium and Alternaria. These fungi may be harmful to the health of poultry and human beings, so permanent monitoring of microbial air quality in chicken houses is necessary.

Familial focal epilepsy with variable foci is an autosomal dominant disorder characterized by partial epilepsy with variable foci. In this study, we report a six-generation with segregation of the mutation present in four generations Chinese family presenting with focal epilepsy with variable foci. Whole exome sequencing confirms a novel pathogenic mutation in the NPRL3 gene (c316C>T; p. Q106*). PCR, Western blotting, and immunohistochemistry were conducted to analyze the gene transcription, protein expression, and subcellular localization of NPRL3 and related signaling molecules in peripheral blood cells from family members. As compared with healthy family members, both mRNA level and protein expression of NPRL3 are decreased in peripheral blood cells of the mutation carrier. In addition, the expression of downstream molecular Phospho-p70 S6 kinase (P-s6k) are increased consequently. Our findings expand the genotypic and phenotypic spectrum of the NPRL3-associated epilepsy and reveal the mechanisms of mTOR pathway signaling and GATOR1 pathogenesis in focal epilepsies, providing exciting potential for future diagnostic and therapeutic interventions. However, further in vitro and animal experiments are still needed to evaluate the role of NPRL3 loss-of-function mutation in epileptogensis.

Background: Egg cannibalism is common in nature. In China, Arma custos (Hemiptera: Asopinae) has been widely used as a natural enemy to control agricultural and forestry pests. A previous study showed that adult A. custos devour their eggs. However, no research has investigated the interaction between A. custos cannibalism and egg development. Clarifying the mechanisms involved in egg cannibalism by A. custos improves our understanding of the evolutionary relationships to enable more efficient mass rearing and biological control systems.Results: Virgin females showed a lower egg cannibalism inclination than gravid females. Both virgin and mated females showed a higher egg cannibalism inclination than virgin and mated males. The first and second instar nymphs did not devour eggs. The third, fourth, and fifth instar nymphs devoured eggs. Younger eggs were more readily eaten than older eggs. Neither A. custos nymphs nor female adults consumed all the available eggs, allowing an emergence ratio of >70%.Conclusion:Arma custos females exhibit a higher tendency for egg cannibalism than males. Egg cannibalism varies not only with the developmental stage of the eggs and nymphs but also with sex and reproductive status of A. custos females. These findings help us to better understand the evolutionary relationships in egg cannibalism by A. custos and contribute to the efficient mass rearing and realization of A. custos in biological control systems.

The successful invasion of Ambrosia artemisiifolia is largely due to allelopathy. As an invasive alien plant, A. artemisiifolia has spread rapidly in Asia and Europe. Studies have shown that sesquiterpenoids play an important role in plant allelopathy. However, it is unclear whether the inflorescence of A. artemisiifolia also contains allelopathic components. In this paper, our phytochemical research focuses on the inflorescence of A. artemisiifolia. Twenty sesquiterpenoids, including four new ones (1–4) were isolated through successive chromatographic columns and identified by spectroscopic methods. At a concentration of 200 μg/mL, all the compounds tested were evaluated for their allelopathic activities on seedling growth of wheat. Our results indicate that nine compounds inhibited both the root and shoot growth of seedlings. Compounds 14, 15, 17, and 20 significantly inhibited root length, which was more than 50% shorter than the control. This study identified the chemical profile of the sesquiterpenoids occurring in the inflorescence of A. artemisiifolia. The bioactivity screening results provide further understanding of the chemical basis of allelopathy in A. artemisiifolia.

The growth, survival, and non-structural carbohydrate metabolism in Salix triandroides cuttings, cultivated under no flooding, incomplete submergence, or complete submergence conditions (0, 25, and 50 cm of water above the soil surface, respectively), were measured after 50, 80, 110, and 140 days. Both submergence conditions decreased the biomass of the leaf, stem, and root, plant height, root length, and root number. As the duration of the treatments increased, these growth parameters gradually increased for the control and incompletely submerged conditions, but remained relatively constant for the completely submerged condition. The survival ratio was 100% across the experimental period for plants under the control and incompletely submerged conditions; however for plants under the completely submerged condition, it was 100% after 50 and 80 days but decreased to 91.7 and 33.3% after 110 and 140 days, respectively. Compared with the plants under control and incomplete submergence conditions, the completely submerged plants had significantly lower concentrations of soluble sugars and starch. As the concentration of soluble sugars in the completely submerged plants fell to 19.2%, and that of starch to 23.5% of that in the control plants, their survival ratio decreased to 33.3%. The results indicated that the survival of the S. triandroides cuttings grown in complete submergence conditions was associated with non-structural carbohydrate metabolism.

Abstract Background Chemosensory proteins are a family of insect-specific chemical sensors that sense specific chemical cues and regulate insect behavior. Chemosensory proteins have been identified and analyzed in many insect species, such as Drosophila melanogaster, Bactrocera dorsalis and Calliphora stygia. This research has revealed that these proteins play a crucial role in insect orientation, predation and oviposition. However, little is known about the chemosensory proteins of Chlorops oryzae, a major pest of rice crops throughout Asia. Results Comparative transcription analysis of the genes of Chlorops oryzae larvae, pupae and adults identified a total of 104 chemosensory genes, including 25 odorant receptors (ORs), 26 odorant-binding proteins (OBPs), 19 ionotropic receptors (IRs), 23 gustatory receptors (GRs) and 11 sensory neuron membrane proteins (SNMPs). The sequences of these candidate chemosensory genes were confirmed and used to construct phylogenetic trees. Quantitative real-time PCR (qRT-PCR) confirmed that the expression of candidate OR genes in different developmental stages was consistent with the fragments per kilobase per million fragments (FPKM) values of differentially expressed genes (DEGs). Conclusions The identification of chemosensory genes in C. oryzae provides a foundation for the investigation of the function of chemosensory proteins in this species, which, in turn, could allow the development of new, improved methods of controlling this pest.

Although antibiotics have played a certain positive role in the prevention and treatment of poultry diseases, as well as the promotion of poultry growth, some farmers use antibiotics in an incorrect way in the breeding process, resulting in antibiotic residues in poultry tissues, organs and edible products. Residual antibiotics enter the human body through the food chain and accumulate, which not only causes poisoning and allergic reactions, but also drug resistance of pathogenic microorganisms, thus endangering the health of consumers. In this investigation, the residues of 24 antibiotics, including fluoroquinolones, sulfonamides, macrolides, tetracyclines, antivirals, lincomycin and florfenicol, were analyzed in 1211 poultry egg samples in Shandong, China, from 2018 to 2020. Then, based on the per capita intake of poultry eggs recommended in the dietary guidelines of Chinese residents, the maximum residue limit of veterinary drugs specified in Chinese regulations and the average weight of males and females aged 18 and over in 2020, the risk of residual antibiotics was evaluated by International Food Safety indices (IFS). The detection results showed that 104 of 1211 samples were detected with antibiotic residues, with a detection rate of 8.58%. Among them, the main residues were enrofloxacin, sulfonamides and florfenicol. The IFS calculation results showed that the IFS of residual antibiotics ranged from 1.44 × 10−7 to 0.102. Therefore, although enrofloxacin, sarafloxacin, danofloxacin, sulfonamides, tilmicosin, doxycycline, florfenicol, which are banned during egg laying, were detected in poultry eggs in Shandong, these residues did not pose a threat to the health of Chinese adult consumers, according to the daily dietary habits of Chinese people. However, it is strongly suggested that Shandong should strengthen the monitoring of antibiotic use during egg laying.

The predatory insect Arma chinensis (Hemiptera: Pentatomidae) is widely distributed in China, where it is also used to control many agricultural and forest pests. The chemosensory genes expressed in its antennae play crucial roles in food-seeking and mating behaviors. To better understand the olfaction of A. chinensis antennae, we identified the genes related to food-seeking and mating. Sequencing of the antennal transcriptomes of full and hungry male and female A. chinensis revealed 38 odorant-binding proteins (OBPs), 1 chemosensory protein (CSP), 1 Niemann–Pick C2 protein (NPC2), 3 odorant receptors (ORs), 12 ionotropic receptors (IRs), 2 gustatory receptors (GRs), and 3 sensory neuron membrane proteins (SNMPs). These results were used to construct phylogenetic trees. A quantitative real-time PCR (qRT-PCR) analysis showed that the relative transcript levels of AchiGR1, AchiGR2, and AchiOBP28 were higher in female than in male antennae in both full and hungry insects, but that the expression of AchiOBP13 and AchiOBP16 was higher only in full A. chinensis females. Thus, the latter genes may encode proteins involved in oviposition selection behavior. AchiGRs (1 and 2), AchiIR6, and AchiOBPs (6–8, 12, 20–22, 28, and 34) were highly expressed only in the antennae of full males, indicating the participation of these genes in mate-searching or male pheromone recognition. The expression of AchiOBP31 in the antennae of starved males, AchiOBPs (15, 18, and 29) in the antennae of starved females, and AchiOBPs (3, 4, and 24) in the antennae of starved males and females suggested that these genes encode food-seeking functions. Our identification of chemosensory genes in A. chinensis antennae and their differential expression in full and hungry insects provides the basis for further functional studies on the chemoreception system of A. chinensis and the sex hormones of predatory insects.

Heat shock proteins are molecular chaperones that are involved in numerous normal cellular processes and stress responses, and heat shock factors are transcriptional activators of heat shock proteins. Heat shock factors and heat shock proteins are coordinated in various biological processes. The regulatory function of heat shock factors in the expression of genes encoding heat shock proteins (Hsps) has been documented in some model insects, however, the role of transcription factors in modulating Hsps in other insects is still limited. In this study, one heat shock factor gene (AhHsf) was isolated and its two potential target genes (AhHsp70 and AhsHsp21) were confirmed from Agasicles hygrophila. AhHsf sequence analysis indicated that it belongs to the Hsfs gene family. RT-qPCR showed that expression levels of heat shock factors and of two heat shock proteins significantly increased under heat stress. Injection with double-stranded Hsf RNA in freshly emerged adult beetles significantly inhibited expression of AhHsp70 and AhsHsp21, shortened the adult survival, drastically reduced egg production, and ultimately led to a decrease in fecundity. RNA interference (RNAi)-mediated suppression of AhHsp70 or AhsHsp21 expression also significantly affected expression of AhHsf. Our findings revealed a potential transcriptional function of AhHsf to regulate expression of AhHsp70 and AhsHsp21, which may play a key role in A. hygrophila thermotolerance. Our results improve our understanding of the molecular mechanisms of the AhHsf - AhHsps signaling pathway in A. hygrophila.

This study collected past sampling data on total concentrations of 12 heavy metals (Cd, Pb, Cr, Hg, Zn, Cu, Ni, Al, Fe, Mn, As, and Co) in surface water bodies, i.e., 168 rivers and 71 lakes, from 1972 to 2017. The intent was to investigate the levels and sources of heavy metal pollution across five decades and five continents. Mean heavy metal concentrations in global river and lake water, and the number of heavy metals with concentrations greater than the published threshold limits as per the standards of both the World Health Organization (WHO) and the United States Environmental Protection Agency (USEPA) were generally lower in the 1970s and 1980s than in the 1990s, 2000s, and 2010s. Over time, heavy metal pollution in surface water has changed from single metal pollution to mixed metal pollution. Heavy metal concentrations in water, and the number of heavy metals with concentrations above the threshold limits for both WHO and USEPA standards were lower in the developed countries of Europe and North America, and higher in the developing countries of Africa, Asia, and South America. Over time, the main sources of metal pollution have changed from mining and manufacturing to rock weathering and waste discharge. The main metal sources differed across the five continents, with fertilizer and pesticide use, along with rock weathering, being dominant in Africa. Mining and manufacturing, along with rock weathering, were dominant in Asia and Europe. Mining and manufacturing, along with fertilizer and pesticide use, were dominant sources in North America, while four sources (mining and manufacturing, fertilizer and pesticide use, rock weathering, and waste discharge) were responsible for the majority of heavy metal pollution in the river and lake water bodies of South America. Additionally, implementing rigorous standards on metal emissions and recycling metals from wastewater are effective for controlling heavy metal source pollution.

Based on the wetland areas recorded in the First National Inventory of Wetland Resources (FNIWR; 1999–2001) and the Second National Inventory of Wetland Resources (SNIWR; 2009–2011), as well as regional environmental parameters including meteorological conditions and land-use structure, the driving forces of changes in China’s wetland area from the FNIWR to the SNIWR were investigated. The total area of China’s wetlands larger than 1 km2 decreased from 384.8 × 103 km2 in the FNIWR to 350.8 × 103 km2 in the SNIWR. Natural wetland areas, including marshes, rivers, lakes, and coastal wetlands, decreased by 33.8 × 103 km2 over the study period, accounting for 99.4% of the decrease in the wetland area. Regions with decreased marsh and reservoir wetland areas were located mainly in Central and Eastern China, and those with increased river and lake wetland areas were located in Western China. There were no significant regression coefficients between the percentages of change in marsh and lake wetland areas and environmental parameters. However, changes in river wetland areas were positively regressed with changes in forest areas, mean annual temperature, and extreme minimum temperature, and changes in reservoir wetland areas were positively regressed with changes in city construction areas and mean annual temperature. Therefore, it seems that increased forest area and regional temperature alleviated the degradation of river wetland areas, while increased city construction areas and regional temperature alleviated the degradation of reservoir areas. Keywords: Marsh, River, Lake, Reservoir, Forest land, Regional temperature

The endoparasitoid body size hypothesis suggests that the size of larvae that develop in a single host should be subject to a trade-off: larger size could lead to increase overall fitness but could simultaneously increase the risk of resource depletion and starvation, resulting in a body size just below the host holding capacity. However, this hypothesis has not been rigorously tested using mathematical models thus far. The camellia weevil, C.styracis (Coleoptera: Curculionidae), is a notorious pest attacking fruits of Camellia oleifera Abel. and C. meiocarpa Hu., in which the larvae develop within a single fruit and larval development is limited by the available food resources. We developed a feasible method to test this hypothesis. First, five models were used to describe the relationship between larval mass and host size. Then, the minimum fruit threshold that had to be met for ad libitum larval development and the corresponding larval size (Wa) of this threshold were calculated based on the characteristics of the optimal model. Finally, the difference between the measured larval size and the predicted larval size (Wa) was determined. The results showed that (1) the data were better described by a logistic function than any other equation; (2) larval size in both host plants increased with increasing fruit size until leveling off when the fruits were large enough to allow unconstrained larval development; (3) larval size remained just below the host-fruit holding capacity, as there was no difference between the measured and predicted larval sizes (Wa); and (4) larvae developed in host plant with larger fruits had a larger size. These results confirmed the endoparasitoid body size hypothesis.

The yolk protein precursor, vitellogenin (Vg), provides nutrition for embryonic development whereas the vitellogenin receptor (VgR) is responsible for the uptake of yolk protein by maturing oocytes. These two proteins are key reproduction-related proteins in insects. We cloned and characterized Vg and VgR genes in Sogatella furcifera, and investigated their function in oocyte maturation. Cloned SfVg and SfVgR have open reading frames of 6,114 and 5,796 bp, encoding 2,037 and 1,931 amino acid residues, respectively. Structural analysis indicates that SfVg has the three conserved LPD_N, DUF1943, and VWFD domains, SfVgR contains all conservative motifs of the LDLR superfamily. Both genes were highly expressed in adult females; SfVg was most highly expressed in the fat body whereas SfVgR was mainly expressed in the ovary. Knockdown of either gene reduced yolk protein deposition in oocytes and arrested oocyte maturation. However, silencing one of these two genes did not affect the transcript level of the other. These results demonstrate the role of SfVgR in transporting SfVg into oocytes. Both SfVg and SfVgR are essential for oocyte maturation in S. furcifera and both genes could potentially be targeted as means of controlling this pest.

Plant volatiles play an important role in regulating insect behavior. Odorant binding proteins (OBPs) are involved in the first step of the olfactory signal transduction pathway and plant volatiles recognition. Sogatella furcifera is one of the most destructive pests of rice crops. Understanding the functions of S. furcifera OBPs (SfurOBPs) in the host plant location and the behavioral responses of S. furcifera to rice plant volatiles could lead to improved, more environmentally-friendly, methods for controlling this pest. We found that SfurOBP1 displayed only weak binding with all the tested volatiles. SfurOBP2, SfurOBP3 and SfurOBP11 had different binding affinities to β-ionone. SfurOBP2 and SfurOBP11 had strong binding affinities to β-caryophyllene (Ki = 2.23 µM) and plant alcohol (Ki = 2.98 µM), respectively. The results of Y-olfactometer experiments indicate that S. furcifera was significantly repelled by octanal and n-octane but strongly attracted by (+)-limonene, acetophenone, 2-heptanone, n-hendecane, α-farnesene and β-ionone. Furthermore, the dsRNA-mediated gene silencing of SfurOBP2, SfurOBP3 and SfurOBP11 shifted the olfactory behavior of S. furcifera for β-ionone, α-farnesene and plant alcohol, respectively. These results suggest that the SfurOBPs are involved in the recognition of rice plant volatiles, and several potential repellants and lures for controlling this pest.

Artificial freezing ground method has been widely used in tunnels, metro and other projects, in the connecting passage in metro, the artificial frozen soil wall, which is formed by artificial freezing method, is often used as temporary support. The artificial frozen soil wall is in the joint action of pressure and bending moment, for it takes the upper pressure and lateral earth pressure at same time, so there may be tensile stress in the profile, which may cause brittle failure. At present, some scholars have carried out researches on the tensile strength with different test methods, but they are insufficiency and have a certain difference in stress state between the specimen and the actual support structure. A bending test instrument was designed and manufacture, which satisfies the code’s requirements, and reduces the error caused by poor contact between the specimen and loading device. Bending test on artificially frozen soils was launched using this instrument, and the test on influence law of moisture content and freezing temperature on artificially frozen soils’ strength was also launched. The conclusions can provide a reference for design and construction.

To better understand the effect of different disinfectants on the types and quantities of microorganisms in a broiler chicken house, five different types of disinfectants, including ozone, available chlorine, quaternary ammonium salt, glutaraldehyde, and mixed disinfectant, were used. The broiler house microbial communities were analyzed by high-throughput sequencing combined with air sampling. The results showed that the concentrations of airborne aerobic bacteria in the empty broiler houses after application of different disinfectants were significantly reduced compared to a house untreated with disinfectant (P < 0.05 or P < 0.01), and the number of inhalable particles of airborne aerobic bacteria sharply decreased after disinfection. Of the five disinfectants, the mixed disinfectant had the best disinfection efficacy on the total microbial communities (P < 0.05). A total of 508,143 high-quality sequences were obtained by high-throughput sequencing, which identified 1995 operational taxonomic units. In total, 42 phyla and 312 genera were identified. The structures of airborne microbial communities in the broiler houses after the different disinfectants were applied differed. In the house treated with the mixed disinfectant, the microbial communities containing opportunistic pathogens, such as Escherichia-Shigella, Bacillus, and Pseudomonas, had the lowest abundance, with a significant decrease compared to the house untreated with disinfectant. The alpha diversity index showed low diversity of the microbial communities in the house treated with mixed disinfectant. In contrast to the other four disinfectants, only a small amount of bacteria was detected in the air sample in the house treated with the mixed disinfectant; specifically, only four phyla were found (Proteobacteria, Bacteroidetes, Actinobacteria, and Firmicutes). The mixed disinfectant produced a positive effect on disinfection for four phyla; however, it didn’t thoroughly eliminate them. At genus level, Bacillus, Arenimonas, and Shinella could not be detected in the house treated with the mixed disinfectant, but were detected in houses treated with other disinfectants. The high-throughput sequencing results revealed that the combination of multiple disinfectants exhibited a good disinfection efficacy and that this technique could disinfect the air of broiler houses. These results will help guide the development of a reasonable program for broiler house disinfection.

A new pseudoguaianolide 1 and two new guaiane-type sesquiterpene glucosides 2 and 3, were isolated from the aerial parts of Ambrosia artemisiifolia L together with two known sesquiterpene dilactones 4 and 5. The new compounds were determined on the basis of spectroscopic and chemical methods to be 3β-acetoxy-4β-hydroxy-1α,7α, 10β,11αH-pseudoguaia-12,8β-olide (1), 1β,7β,9β,10β,13αH-guaia-4(5)-en-12,6β-olide 9-O-β-d-glucoside (2) and 4β-hydroxy-1α,5α,7α,9αH-guaia-10(14),11(13)-dien-12-acid 9-O-β-d-glucoside (3). The isolated compounds were evaluated for cytotoxicity against human promyelocytic leukemia HL-60 cell lines in vitro, but were all inactive.

ADP-glucose pyrophosphorylase (AGPase) is an important enzyme in the starch synthesis pathway. Its enzyme activity can determine the efficiency of starch biosynthesis. Cassava (Manihot esculenta Crantz) is the main staple crop worldwide and has a high starch content in its storage root. However, the inner regulatory mechanism of AGPase gene family is unclear. MePHD1; a plant homeodomain transcription factor; was isolated through a yeast one-hybrid screening using the promoter of ADP-glucose pyrophosphorylase small subunit1a (MeAGPS1a) as bait, and cassava storage root cDNA library as prey. This factor could bind to the MeAGPS1a promoter in vitro and in vivo, and its predicted binding region ranged from −400 bp to −201 bp, at the translation initiation site. The transcript level of MePHD1 could be induced by five plant hormones, and a temperature of 42 °C. This was down-regulated during the maturation process of the storage root. MePHD1 protein could repress the promoter activity of MeAGPS1a gene by a dual-luciferase assay; which indicated that MePHD1 is a negative regulator for the transcript level of MeAGPS1a gene.

Two new clerodane-type diterpenes, tinosporins C (1) and tinosporins D (2) were isolated from the stems of Tinospora sagittata (Oliv.), together with three known ones, columbin (3), tinophylloloside (4), and tinospinoside D (5). The structures of these compounds were determined on the basis of spectroscopic data interpretation, with that of the absolute configuration of compound 1 was assigned by experimental and calculated ECD spectra. The cytotoxicity and α-glucosidase inhibitory activities of isolated compounds were evaluated in vitro.

Three new 30-noroleanane triterpenoid saponins, akebonoic acid 28-O-β-d-glucopyranosyl-(1′′→6′)-β-d-glucopyranosyl ester (1), akebonoic acid 28-O-(6′′-O-caffeoyl)-β-d-glucopyranosyl-(1′′→6′)-β-d-glucopyranosyl ester (Holboelliside A, 2) and 3β,20α,24-trihydroxy-29-norolean-12-en-28-oic acid 3-O-(6′-O-caffeoyl)-β-d-glucopyranoside (Holboelliside B, 3) were isolated from the stems of Holboellia coriacea Diels, together with five known compounds, eupteleasaponin VIII (4), 3α-akebonoic acid (5), quinatic acid (6), 3β-hydroxy-30-norhederagenin (7) and quinatoside A (8). The structures of these compounds were determined on the basis of spectral and chemical evidence. Compounds 1–5 were evaluated for their inhibitory activity against three human tumors HepG2, HCT116 and SGC-7901 cell lines in vitro.