Discussion on the construction of food sampling team

Compared with the inspection， the sampling work directly faces the food producers and operators， which is more likely to be challenged and even raise objections in terms of standardization， representativeness， impartiality， randomness and timeliness. With the in-depth development of food safety sampling inspection， the requirements for the sampling team increased gradually. This paper discusses the construction of specialized and professional sampling team from the aspects of personnel， management， principle， reward and punishment in order to provide more ideas for relevant work. Through literature collection and comprehensive analysis， this paper combs the current situation and possible problems of China’s food safety sampling team， and proposes the targeted measures. Referring to the construction requirements of food inspection team， clarifying the qualification conditions， establishing the information base of sampling personnel， strengthening assessment and evaluation， and unifying supervision and management can effectively improve the professional skills， responsibility and professional pride of sampling team， and improve the quality and effectiveness of sampling work

RpoN (σ54) Is Required for Floc Formation but Not for Extracellular Polysaccharide Biosynthesis in a Floc-Forming Aquincola tertiaricarbonis Strain.

Some bacteria are capable of forming flocs, in which bacterial cells become self-flocculated by secreted extracellular polysaccharides and other biopolymers. The floc-forming bacteria play a central role in activated sludge, which has been widely utilized for the treatment of municipal sewage and industrial wastewater. Here, we use a floc-forming bacterium, Aquincolatertiaricarbonis RN12, as a model to explore the biosynthesis of extracellular polysaccharides and the regulation of floc formation. A large gene cluster for exopolysaccharide biosynthesis and a gene encoding the alternative sigma factor RpoN1, one of the four paralogues, have been identified in floc formation-deficient mutants generated by transposon mutagenesis, and the gene functions have been further confirmed by genetic complementation analyses. Interestingly, the biosynthesis of exopolysaccharides remained in the rpoN1-disrupted flocculation-defective mutants, but most of the exopolysaccharides were secreted and released rather than bound to the cells. Furthermore, the expression of exopolysaccharide biosynthesis genes seemed not to be regulated by RpoN1. Taken together, our results indicate that RpoN1 may play a role in regulating the expression of a certain gene(s) involved in the self-flocculation of bacterial cells but not in the biosynthesis and secretion of exopolysaccharides required for floc formation.IMPORTANCE Floc formation confers bacterial resistance to predation of protozoa and plays a central role in the widely used activated sludge process. In this study, we not only identified a large gene cluster for biosynthesis of extracellular polysaccharides but also identified four rpoN paralogues, one of which (rpoN1) is required for floc formation in A. tertiaricarbonis RN12. In addition, this RpoN sigma factor regulates the transcription of genes involved in biofilm formation and swarming motility, as previously shown in other bacteria. However, this RpoN paralogue is not required for the biosynthesis of exopolysaccharides, which are released and dissolved into culture broth by the rpoN1 mutant rather than remaining tightly bound to cells, as observed during the flocculation of the wild-type strain. These results indicate that floc formation is a regulated complex process, and other yet-to-be identified RpoN1-dependent factors are involved in self-flocculation of bacterial cells via exopolysaccharides and/or other biopolymers

Wear Characteristics of the Material Specimen and Method of Predicting Wear in Floating Spline Couplings of Aero-Engine

In order to reduce wear and design high-performance spline coupling, the friction coefficient, wear coefficient, and wear depth of 14 groups of material specimens were tested using multifunctional friction and wear tester. The effect of materials, loads, rotation speed, and surface treatment on friction coefficient, wear coefficient, and wear depth was investigated. A method using an Archard’s equation based on the finite element method to calculate the wear depth of 14 groups of material specimens was proposed, and the results were consistent with the experimental results. Then, the wear of a floating involute spline coupling of aero-engine was predicted using this method. It can be concluded that carburizing and silvering can decrease the friction coefficient. The wear and wear coefficient decreased after carburizing. So, it is necessary to take 18CrNi4A with carburization and 32Cr3MoVA with nitridation as the material of the spline coupling in aero-engine to minimize wear. Furthermore, the method presented to predicate the wear of spline coupling in this work provided a good fundament for the fatigue prediction methodology of spline coupling

A study of the factors influencing knowledge management within inter-organizational projects

Presented at the GLOBELICS 6th International Conference 2008 22-24 September, Mexico City, Mexico.Modern management theories agree that the effective use of knowledge management (KM) is one of the key determinants in the performance of a business organization. KM permits a firm to accurately measure its adaptability and competencies and predict its survival in the market place. There are two types of KM: one that focuses upon measuring the performance of a single organization (known as "internal KM") and another that measures performance across organizational boundaries (known as "cross-organizational KM"). This research deals only with cross-organizational KM, a topic that has received scant attention in prior studies. The research focuses upon the factors that are measured to produce a statistical analysis of performance in cross-organizational collaborations. The study concludes that four clusters of factors have the greatest influence on the success of interorganizational projects. These clusters relate to: knowledge reserve, corporate culture/institution, communication and cooperation, and the characteristics of the specific project

Generation of a synthetic aperture radar deception jamming signal based on a deep echo inversion network

Abstract Existing methods for generating synthetic aperture radar (SAR) deception jamming signals have slow speed, low imaging quality, and insufficient intelligence in complex electromagnetic environments. This paper proposes a deep learning‐based SAR deception jamming signal generation method based on deep echo inversion Unet (DEIUnet). This method has high speed and provides high‐image quality of the interference signal. A Swin Next (SN) block is proposed to combine local and non‐local information in the image and echo data. The Unet structure consists of SN blocks, and a residual connection is used as the jump connection to fuse the multi‐scale feature information from the echo and image data. PixelShuffle is utilised for up‐sampling to generate high‐quality echo data. The experimental results on MSTAR and Sentinel‐1 data sets verify the effectiveness and superiority of DEIUnet for echo inversion. The imaging results of the SAR deception jamming signal generated by DEIUnet on an MSTAR scene confirm the effectiveness of the proposed method

Genome-wide association studies (GWAS) and post-GWAS analyses of impulsivity: A systematic review

Impulsivity is related to a host of mental and behavioral problems. It is a complex construct with many different manifestations, most of which are heritable. The genetic compositions of these impulsivity manifestations, however, remain unclear. A number of genome-wide association studies (GWAS) and post-GWAS analyses have tried to address this issue. We conducted a systematic review of all GWAS and post-GWAS analyses of impulsivity published up to December 2023. Available data suggest that single nucleotide polymorphisms (SNPs) in more than a dozen of genes (e.g., CADM2, CTNNA2, GPM6B) are associated with different measures of impulsivity at genome-wide significant levels. Post-GWAS analyses further show that different measures of impulsivity are subject to different degrees of genetic influence, share few genetic variants, and have divergent genetic overlap with basic personality traits such as extroversion and neuroticism, cognitive ability, psychiatric disorders, substance use, and obesity. These findings shed light on controversies in the conceptualization and measurement of impulsivity, while providing new insights on the underlying mechanisms that yoke impulsivity to psychopathology

Modulation Model of High Frequency Band Radar Backscatter by the Internal Wave Based on the Third-Order Statistics

Modulation model of radar backscatters is an important topic in the remote sensing of oceanic internal wave by synthetic aperture radar (SAR). Previous studies related with the modulation models were analyzed mainly based on the hypothesis that ocean surface waves are Gaussian distributed. However, this is not always true for the complicated ocean environment. Research has showed that the measurements are usually larger than the values predicted by modulation models for the high frequency radars (X-band and above). In this paper, a new modulation model was proposed which takes the third-order statistics of the ocean surface into account. It takes the situation into consideration that the surface waves are Non-Gaussian distributed under some conditions. The model can explain the discrepancy between the measurements and the values calculated by the traditional models in theory. Furthermore, it can accurately predict the modulation for the higher frequency band. The model was verified by the experimental measurements recorded in a wind wave tank. Further discussion was made about applicability of this model that it performs better in the prediction of radar backscatter modulation compared with the traditional modulation model for the high frequency band radar or under lager wind speeds

Quality predictive models for bovine liver during storage and changes in volatile flavors

Protein and fat oxidation are important factors that influence the quality of bovine liver. The objectives of this study were to investigate the degree of oxidation changes in bovine livers during 90d at different temperatures (−20°C, −10°C, 0°C, 10°C, and 20°C), and to develop Arrhenius models to predict its degree of oxidation.Carbonyl, thiobarbituric acid (TBA), peroxide value (POV) as oxidation attributes of bovine liver during storage were measured at different time and the changes were kinetically modeled using the Arrhenius equation. The activation energies of carbonyl, (TBA) and (POV) were 27.48, 55.48, and 58.94 KJ/mol, respectively. The determination coefficients (R2) were above 0.97 for all. In addition, volatile compounds in bovine liver and consumer acceptance of bovine liver pate with bovine liver as the final product were also measured. Among the volatile compounds, The content of aldehydes and ketones in bovine livers stored at different temperatures increased significantly (p < 0.05). Consumer acceptance of bovine liver indicates that consumers prefer bovine liver paste made from bovine liver stored at lower temperatures (below 0°C)