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Understanding how to defend against adversarial attacks is crucial for ensuring the safety and reliability of these systems in real-world applications. Various adversarial defense methods are proposed, which aim at improving the robustness of neural networks against adversarial attacks by changing the model structure, adding detection networks, and adversarial purification network. However, deploying adversarial defense methods in existing DNN accelerators or defensive accelerators leads to many key issues. To address these challenges, this article proposes sDNNGuard, an elastic heterogeneous DNN accelerator architecture that can efficiently orchestrate the simultaneous execution of original (target) DNN networks and the detect algorithm or network. It not only supports for dense DNN detect algorithms, but also allows for sparse DNN defense methods and other mixed dense-sparse (e.g., dense-dense and sparse-dense) workloads to fully exploit the benefits of sparsity. sDNNGuard with a CPU core also supports the non-DNN computing and allows the special layer of the neural network, and used for the conversion for sparse storage format for weights and activation values. To reduce off-chip traffic and improve resources utilization, a new hardware abstraction with elastic on-chip buffer/computing resource management is proposed to achieve dynamical resource scheduling mechanism. We propose an extended AI instruction set for neural networks synchronization, task scheduling and efficient data interaction. Experiment results show that sDNNGuard can effectively validate the legitimacy of the input samples in parallel with the target DNN model, achieving an average 1.42× speedup compared with the state-of-the-art accelerators. [ABSTRACT FROM AUTHOR]

Arcobacter (A.) butzleri is an emerging zoonotic pathogen associated with gastrointestinal diseases, such as abdominal cramps and diarrhea, and is widely detected in animals, showing a high prevalence in poultry and seafood. The survival and adaptation of A. butzleri to cold temperatures remains poorly studied, although it might be of interest for food safety considerations. To address this, growth patterns of eight A. butzleri isolates were determined at 8 °C for 28 days. A. butzleri isolates showed strain‐dependent behavior: six isolates were unculturable after day 18, one exhibited declining but detectable cell counts until day 28 and one grew to the stationary phase level. Out of 13 A. butzleri cold shock‐related genes homologous to Escherichia coli, 10 were up‐regulated in response to a temperature downshift to 8 °C, as demonstrated by reverse transcription‐quantitative PCR. Additionally, we compared these data with the cold‐shock response in E. coli. Overall, we provide a deeper insight into the environmental adaptation capacities of A. butzleri, which we find shares similarities with the E. coli cold‐shock response. [ABSTRACT FROM AUTHOR]

In the traditional control strategy for single-phase PWM converter applications, the proportional-integral (PI) controller has the role of voltage tracking in the outer loop voltage controller, which has limited capability to provide acceptable dynamic performance and disturbance rejection. With regard to this, this article proposes a voltage control strategy based on the active disturbance rejection control (ADRC) for single-phase cascaded H-bridge rectifiers, aiming at achieving satisfactory dynamic performance and strong robustness to the disturbances. First, the extended state observer is used for the state and disturbance estimations. Then, the nonlinear state error feedback deals with the system error and makes the dynamic compensation to the disturbances. More specifically, an improved continuous nonlinear function is adopted to mitigate the jitter behavior of the traditional ADRC and provide immunity to large disturbance errors. Furthermore, the performance and stability analysis of the proposed strategy are implemented. A parameter tuning guideline of the proposed strategy is detailed. The effectiveness of the proposed ADRC-based voltage control strategy is verified through extensive experimental tests and is compared to that of the conventional PI-based voltage control strategy. [ABSTRACT FROM AUTHOR]

Campylobacterjejuni is an important foodborne pathogen worldwide; however, there is a lack of information on the prevalence and antibiotic-resistant profile of C. jejuni in the People's Republic of China. We determined the prevalence and characteristics of C. jejuni on the retail level in Tianjin, one of the five national central cities in China. A total of 227 samples of chicken wings, legs, and breasts were collected from supermarkets and wet markets; 42 of these samples were confirmed to be positive for Campylobacter contamination. The contamination rates of C. jejuni and other Campylobacter species were 13.7% (31 of 227 samples) and 5.7% (13 of 227 samples), respectively. A group of 31 C. jejuni isolates was subjected to antimicrobial susceptibility testing. All (100%) the selected isolates were resistant to ciprofloxacin and nalidixic acid; 77.4% were resistant to tetracycline, 67.7% to doxycycline, 35.5% to gentamicin, 25.8% to clindamycin and florfenicol, 19.4% to chloramphenicol, and 12.9% to erythromycin and azithromycin. A remarkably high proportion (41.9%) of multidrug-resistant isolates was identified. Multilocus sequence typing was conducted to study the population structure of the C. jejuni strains and their relationship to human isolates. The correlation between antimicrobial resistance traits and certain sequence types (STs) or clonal complexes was determined as well. A great genetic diversity of poultry isolates was identified, with 11 STs belonging to 6 clonal complexes and 11 singleton STs. The novel STs accounted for 40.9% (n = 9) of the 22 STs. ST-21, ST-353, ST-354, ST-443, ST-607, and ST-828 complexes had been previously identified from human isolates. This study revealed an extensive level of antimicrobial resistance and genetic diversity in C. jejuni isolated from chicken products in Tianjin, highlighting the necessity of performing enforced interventions to reduce Campylobacter prevalence in China. [ABSTRACT FROM AUTHOR]

Gaomiaozi (GMZ) bentonite is regarded as the favorable candidate backfilling material for a potential repository in China. It is important to understand the diffusion behavior of I in GMZ bentonite and compare the diffusion behavior in GMZ and other types of bentonite like MX-80, Avonlea, etc. Therefore, through- and out-diffusion experiments were conducted to obtain the effective diffusion coefficient ( D) and distribution coefficient ( K). A computer code named Fitting for diffusion coefficient (FDP) was used for the experimental data processing and theoretical modeling. At the dry density of GMZ bentonite from 1600-2000 kg/m, the D values of I were (2.4-20.4) ¢ 10 m/s and K values were constants. At dry density above 1800 kg/m, the diffusion behaviors were almost the same, indicating that the anion exclusion was ineffective. Out-diffusion results showed that the species of I may be changed during the diffusion processing. It was probably caused by some organic matters or reducing substances in GMZ bentonite. Since the main composition of bentonite is montmorillonite, similar diffusion parameters were obtained in GMZ and other types of bentonite. The relationship of D and accessible porosity ( ɛ) could be described by Archie's law with exponent n = 1.2-2.8 for I diffusion in bentonite, whereas n = 2.0 in GMZ bentonite. Furthermore, bentonite with the dry density of 1800 kg/m was proposed as the backfilling materials used in the construction of high level radioactivity waste repository. [ABSTRACT FROM AUTHOR]

Flagellation is one of the major virulence factors of Campylobacter jejuni (C. jejuni), enabling bacterial cells to swarm in rather high viscous fluids. The aim of this study was to determine the impact of the surrounding viscosity on the expression of motility related genes of C. jejuni. Therefore, bacterial RNA was extracted from liquid cultures as well as from bacterial cells recovered from the edge and the center of a swarming halo from high viscous media. The expression pattern of selected flagellar and chemotaxis related genes was investigated by RT-PCR. Higher mRNA levels of class 1 and lower levels of class 2 and 3 flagellar assembly genes were detected in cells derived from the edge of a swarming halo than in cells from the center. This indicates different growth states at both locations within the swarming halo. Furthermore, higher mRNA levels for energy taxis and motor complex monomer genes were detected in high viscous media compared to liquid culture, indicating higher demand of energy if C. jejuni cells were cultivated in high viscous media. The impact of the surrounding viscosity should be considered in future studies regarding motility related questions.

Even though Campylobacter spp. are known to be fastidious organisms, they can survive within the natural environment. One mechanism to withstand unfavourable conditions is the formation of biofilms, a multicellular structure composed of different bacterial and other microbial species which are embedded in an extracellular matrix. High oxygen levels, low substrate concentrations and the presence of external DNA stimulate the biofilm formation by C. jejuni. These external factors trigger internal adaptation processes, e.g. via regulating the expression of genes encoding proteins required for surface structure formation, as well as motility, stress response and antimicrobial resistance. Known genes impacting biofilm formation will be summarized in this review. The formation of biofilms as well as the expression of virulence genes is often regulated in a cell density depending manner by quorum sensing, which is mediated via small signalling molecules termed autoinducers. Even though quorum sensing mechanisms of other bacteria are well understood, knowledge on the role of these mechanisms in C. jejuni biofilm formation is still scarce. The LuxS enzyme involved in generation of autoinducer-2 is present in C. jejuni, but autoinducer receptors have not been identified so far. Phenotypes of C. jejuni strains lacking a functional luxS like reduced growth, motility, oxygen stress tolerance, biofilm formation, adhesion, invasion and colonization are also summarized within this chapter. However, these phenotypes are highly variable in distinct C. jejuni strains and depend on the culture conditions applied.

The aim of the study was to investigate the molecular epidemiologic of Staphylococcus aureus isolated from seven staphylococcal food-poisoning (SFP) outbreaks between 2006 and 2013 in Xi'an, northwest China. A total of seven S. aureus isolates associated with seven SFP outbreaks were obtained and characterized by determining the multilocus sequence typing, spa typing, pulsed-field gel electrophoresis (PFGE), antimicrobial susceptibility, toxin and resistant genes. The results showed that S. aureus ST6-t701 (71.4%) was the most predominant clone, followed by ST5-t002 and ST59-t172 (each 14.3%). Seven different PFGE patterns were obtained. Moreover, resistance was most frequently observed to trimethoprim and penicillin (each 71.4%), followed by erythromycin (28.6%), ampicillin, clindamycin, and tetracycline (each 14.3%). All strains were susceptible to chloramphenicol, cefoxitin, oxacillin, amikacin, and vancomycin. Three of seven strains displayed resistance to three or more antimicrobials. Resistance genes were found as follows: linA/linA' (100%), blaZ (85.7%), tet(K), ermC, ermT, and ermB (each 14.3%). Other resistant genes were not detected. In addition, the most frequently identified exotoxin genes were seu, lukED, hla, hlb, hld (each 100%), followed by hlg and hlgv (each 85.7%), lukPV (71.4%), sea (57.1%), see (42.9%), etd (28.6%), and seb, sec, sed, sej, and sek (each 14.3%). The results indicated that S. aureus ST6-t701, with a high prevalence in the northwest of China, exhibited multidrug resistance and harbored multiple toxin and resistance genes. Therefore, strict hygienic and preventative measures should be taken in order to avoid the contamination of food by S. aureus and toxin production in foods.