59 research outputs found

    Molecular Cloning and Expression Analysis of the Endogenous Cellulase Gene MaCel1 in Monochamus alternatus

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    The purpose of this study was to characterize the endogenous cellulase gene MaCel1 of Monochamus alternatus, which is an important vector of Bursaphelenchus xylophilus, a pine wood nematode, which causes pine wilt disease (PWD). In this study, MaCel1 was cloned by rapid amplification of cDNA end (RACE), and its expression analyzed by RT-qPCR (real-time quantitative PCR detecting). A total of 1778 bp of cDNA was obtained. The encoding region of this gene was 1509 bp in length, encoding a protein containing 502 amino acids with a molecular weight of 58.66 kDa, and the isoelectric point of 5.46. Sequence similarity analysis showed that the amino acids sequence of MaCel1 had high similarity with the beta-Glucosinolate of Anoplophora glabripennis and slightly lower similarity with other insect cellulase genes (GH1). The beta-D-Glucosidase activity of MaCel1 was 256.02 +/- 43.14 U/L with no beta-Glucosinolate activity. MaCel1 gene was widely expressed in the intestine of M. alternatus. The expression level of MaCel1 gene in male (3.46) and female (3.51) adults was significantly higher than that in other developmental stages, and the lowest was in pupal stage (0.15). The results will help reveal the digestive mechanism of M. alternatus and lay the foundation for controlling PWD by controlling M. alternatus

    Gut Bacterial Communities of Lymantria xylina and Their Associations with Host Development and Diet

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    The gut microbiota of insects has a wide range of effects on host nutrition, physiology, and behavior. The structure of gut microbiota may also be shaped by their environment, causing them to adjust to their hosts; thus, the objective of this study was to examine variations in the morphological traits and gut microbiota of Lymantria xylina in response to natural and artificial diets using high-throughput sequencing. Regarding morphology, the head widths for larvae fed on a sterilized artificial diet were smaller than for larvae fed on a non-sterilized host-plant diet in the early instars. The gut microbiota diversity of L. xylina fed on different diets varied significantly, but did not change during different development periods. This seemed to indicate that vertical inheritance occurred in L. xylina mutualistic symbionts. Acinetobacter and Enterococcus were dominant in/on eggs. In the first instar larvae, Acinetobacter accounted for 33.52% of the sterilized artificial diet treatment, while Enterococcus (67.88%) was the predominant bacteria for the non-sterilized host-plant diet treatment. Gut microbe structures were adapted to both diets through vertical inheritance and self-regulation. This study clarified the impacts of microbial symbiosis on L. xylina and might provide new possibilities for improving the control of these bacteria

    Differences in Physicochemical and Nutritional Properties of Breast and Thigh Meat from Crossbred Chickens, Commercial Broilers, and Spent Hens

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    The objective of this study was to compare the physicochemical and nutritional properties of breast and thigh meat from commercial Chinese crossbred chickens (817 Crossbred chicken, 817C), imported commercial broilers (Arbor Acres broiler, AAB), and commercial spent hens (Hyline Brown, HLB). The crossbred chickens, commercial broilers and spent hens were slaughtered at their typical market ages of 45 d, 40 d, and 560 d, respectively. The results revealed that several different characteristic features for the three breeds. The meat of the 817C was darker than that of the other two genotypes. The 817C were also characterized by higher protein, lower intramuscular fat, and better texture attributes (cooking loss, pressing loss and Warner-Bratzler shear force [WBSF]) compared with AAB and HLB. The meat of the spent hens (i.e. HLB) was higher in WBSF and total collagen content than meat of the crossbred chickens and imported broilers. Furthermore, correlation analysis and principal component analysis revealed that there was a clear relationship among physicochemical properties of chicken meats. With regard to nutritional properties, it was found that 817C and HLB exhibited higher contents of essential amino acids and essential/non-essential amino acid ratios. In addition, 817C were noted to have highest content of microelements whereas AAB have highest content of potassium. Besides, 817C birds had particularly higher proportions of desirable fatty acids, essential fatty acids, polyunsaturated/saturated and (18:0+18:1)/16:0 ratios. The present study also revealed that there were significant differences on breast meat and thigh meat for the physicochemical and nutritional properties, regardless of chicken breeds. In conclusion, meat of crossbred chickens has some unique features and exhibited more advantages over commercial broilers and spent hens. Therefore, the current investigation would provide valuable information for the chicken meat product processing, and influence the consumption of different chicken meat

    ROBUSTNESS OF DEEP NEURAL NETWORKS TO ADVERSARIAL EXAMPLES

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    Deep neural networks have achieved state-of-the-art performance in many artificial intelligence areas, such as object recognition, speech recognition and machine translation. While the deep neural networks have high expression capabilities, they are prone to over fitting due to the high dimensionalities of the networks. Recently, deep neural networks are found to be unstable to adversarial perturbations, which are small but can maximize the network’s prediction error. This paper proposes a novel training algorithm to improve the robustness of the neural networks to adversarial examples

    Pathogenicity virulence of Beauveria spp. and biosafety of the BbMQ strain on adult ectoparasitic beetles, Dastarcus helophoroides Fairmaire (Coleoptera: Colydiidae)

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    IntroductionBeauveria spp. and Dastarcus helophoroides Fairmaire adults were simultaneously released to attack elder larvae or pupae of Monochamus alternatus in pine forests in China. However, little is known about the pathogenicity virulence and biosafety of Beauveria spp. on beneficial adults of D. helophoroides, and specific Beauveria bassiana (Bb) strains should be selected for synthetic release together with D. helophoroides.MethodsA total of 17 strains of Beauveria spp. were collected, isolated, and purified, and then their mortality, cadaver rate, LT50, spore production, spore germination rate, and growth rate of D. helophoroide adults were calculated based on 0–20 days data after spore suspension and powder contact.Results and discussionThe lethality rate of BbMQ, BbFD, and BbMH-03 strains to D. helophoroides exceeded 50%, and the cadaver rate reached 70.6%, among which the mortality rate (82.22%), cadaver rate (47.78%), spore production (1.32 × 109 spores/ml), spore germination rate (94.71%), colony dimension (49.15 mm2), and LT50 (10.62 d) of the BbMQ strain were significantly higher than those of other strains (P < 0.01), and the mortality of D. helophoroides adults increased significantly with increased spore suspension concentration, with the highest mortality reaching 92.22%. This strain was identified as Beauveria bassiana by morphological and molecular methods, while the BbWYS strain had a minimum lethality of only 5.56%, which was safer compared to other strains of adult D. helophoroide. Consequently, the biological characteristics and pathogenicity of different Beauveria bassiana strains varied significantly in their effects on D. helophoroide adults, and the safety of different strains should be assessed when they are released or sprayed to control multiple pests in the forest. The BbMQ strain should not be simultaneously sprayed with releasing D. helophoroide adults in the same forest, while the BbWYS strain can be used in concert with D. helophoroide to synergize their effect

    The complete mitochondrial genome of Epicauta ruficeps (Coleoptera: Meloidae)

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    Epicauta ruficeps is widely distributed in China and some countries in Southeast Asia, and plays an important role in medicine and biological control. The complete mitochondria genome of E. ruficeps was 15,813 bp in length, with 37 genes, including 13 PCGs, 22 tRNA genes (tRNAs), and two rRNA genes (rRNAs). The positions and sequences of genes were consistent with those of known Meloidae species. The nucleotide composition was highly A + T biased, accounting for ∼65% of the whole mitogenome. The complete mitogenome of E. ruficeps would help understand Meloidae evolution

    An Exploration of a Synthetic Construction Land Use Quality Evaluation Based on Economic-Social-Ecological Coupling Perspective: A Case Study in Major Chinese Cities

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    Recently, with the rapid increase of urban population and industrial agglomeration, the price of construction land has increased, and construction land has become increasingly scarce. Therefore, how to improve the construction land use quality (CLUQ) becomes more and more important. The purpose of the study is to evaluate CLUQ in China’s major cities and to analyze the dominant obstacle factors for quality improvement in order to provide policy advice for construction land management. This study adapts the data from 2014 to 2016 and constructs the evaluation framework of CLUQ involving economic quality, social quality, and ecological quality of construction land to evaluate and analyze CLUQ with the synthetic evaluation model, coupling evaluation model, and obstacle diagnosis model (ECO model). This study shows that the synthetic CLUQ of 23 cities out of 36 major cities in China shows a general increasing state. The economic quality of 26 cities out of 36 major cities in China has increased, while the social and ecological quality of 20 out of 36 major cities in China has decreased. In terms of spatial characteristics, the synthetic quality in the east and southwest of China is relatively high; in terms of spatial trend, the synthetic quality in longitude increases from west to east, and it shows an inverted U-shaped state in latitude. Moreover, economic development is the main obstacle factor for the improvement of CLUQ in Hohhot, Lanzhou, Urumqi, and Changchun. Social development results in the CLUQ lagging in Beijing, Guiyang, Shanghai, Xining, and Chongqing. Ecological development has a negative impact in that of Harbin, Qingdao, and Wuhan. Furthermore. The improvement of CLUQ lies in the coupling and coordinated development of economic, social, and ecological quality. For those with a low coupling degree, the targeted suggestions are given for different types based on city’s quadrant distribution

    A survey on pupae parasitoid species of Dendrolimus houi (Lajonquiere) (Lepidoptera, Lasiocampidae) in China

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    Cryptomeria japonica var. sinensis Miquel in south China is currently overwhelmingly infested by a native caterpillar species, Dendrolimus houi (Lepidoptera), which is causing severe economic losses and ecological disasters in both planted and natural forests. Our results include report of five parasitoid species and eight parasitoid flies within D. houi and a dominant endoparasitoid species Kriechbaumerella dendrolimi, which attacks pupae of D. houi with a high parasitism rate. This result might be helpful to improve better identification and application in the future for potential biological control of D. houi in the forests of east Asia

    An approach to pilot air-combat behavior assessment

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    Comparative Transcriptome Analysis of Two Populations of <i>Dastarcus helophoroides</i> (Fairmaire) under High Temperature Stress

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    The differentially expressed genes (DEGs), key genes and metabolic pathways of the parasitic beetle, Dastarcus helophoroides (Fairmaire), were compared between the fiftieth commercially reared population and the first natural population to reveal the adaptive mechanism in response to high temperature stress. The high-throughput sequencing technique was employed for transcriptome sequencing of two populations of D. helophoroides. In total, 47,763 non-redundant transcripts with the average length of 989.31 bp and the N50 of 1607 bp were obtained. Under high temperature stress, 1108 DEGs were found in the commercial population; while there were 3946 DEGs in the natural population, which were higher than those in the commercial population (3.56 times). High temperature stress of D. helophoroides promoted the expression of heat shock proteins (HSPs) and metabolism-related genes in both populations, but metabolism synthesis and hydrolysis of natural population was much higher, allowing them to produce more resistant substances (such as HSPs, superoxide dismutase (SOD), peroxiredoxin (Prx), etc.). Therefore, HSPs may play a major role in the high temperature adaptation of a commercial population, while the natural population probably respond to heat stress with more resistant substances (such as HSPs, SOD, Prx, etc.). These results provide a reference to select and domesticate a specific ecotype with stronger adaptability to the high temperature weather in the forest and further improve the efficiency of D. helophoroides as a bio-control factor
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