Efficient Dropout-resilient Aggregation for Privacy-preserving Machine Learning

With the increasing adoption of data-hungry machine learning algorithms, personal data privacy has emerged as one of the key concerns that could hinder the success of digital transformation. As such, Privacy-Preserving Machine Learning (PPML) has received much attention from both academia and industry. However, organizations are faced with the dilemma that, on the one hand, they are encouraged to share data to enhance ML performance, but on the other hand, they could potentially be breaching the relevant data privacy regulations. Practical PPML typically allows multiple participants to individually train their ML models, which are then aggregated to construct a global model in a privacy-preserving manner, e.g., based on multi-party computation or homomorphic encryption. Nevertheless, in most important applications of large-scale PPML, e.g., by aggregating clients' gradients to update a global model for federated learning, such as consumer behavior modeling of mobile application services, some participants are inevitably resource-constrained mobile devices, which may drop out of the PPML system due to their mobility nature. Therefore, the resilience of privacy-preserving aggregation has become an important problem to be tackled. In this paper, we propose a scalable privacy-preserving aggregation scheme that can tolerate dropout by participants at any time, and is secure against both semi-honest and active malicious adversaries by setting proper system parameters. By replacing communication-intensive building blocks with a seed homomorphic pseudo-random generator, and relying on the additive homomorphic property of Shamir secret sharing scheme, our scheme outperforms state-of-the-art schemes by up to 6.37$\times$ in runtime and provides a stronger dropout-resilience. The simplicity of our scheme makes it attractive both for implementation and for further improvements.Comment: 16 pages, 5 figures. Accepted by IEEE Transactions on Information Forensics and Securit

Multifunctional imaging enabled by optical bound states in the continuum with broken symmetry

For photonic crystal slab (PCS) structures, bound states in the continuum (BICs) and circularly polarized states (dubbed C-points) are important topological polarization singularities in momentum-space and have attracted burgeoning attention due to their novel topological and optical properties. In our work, the evolution of polarization singularities from BICs to C-points is achieved by breaking the in-plane C2 symmetry of a PCS structure of a square lattice with C4v symmetry. Correspondingly, a BIC is split into two C-points with opposite chirality, incurring distinct optical transmission responses with the incidence of right or left circular polarization (RCP or LCP). Harnessing such chirality selectivity of the C-points, we propose a multifunctional imaging system by integrating the designed PCS into a conventional 4-f imaging system, to realize both the edge imaging and conventional bright-field imaging, determined by the circular polarization state of the light source. In addition to multifunctional imaging, our system also provides a vivid picture about the evolution of the PCS platforms' singularities.Comment: 11 pages, 4 figure

Effects of pore connectivity and water saturation on matrix permeability of deep gas shale

Shale matrix permeability is an important indicator for evaluating gas transport and production. However, the effects of pore connectivity and water saturation on the matrix permeability in deep gas shales have not been adequately studied. In this study, the permeability of deep shales in the Yichang area of the Middle Yangtze was characterized using three methods. These included the determination of apparent permeability in different directions via pulse-decay, also matrix permeability obtained via the Gas Research Institute method, and the connected pore network permeability via the mercury injection capillary pressure technique. The results revealed a significant difference between the horizontal and vertical permeability of deep shales. The smaller the size of the multiple connected pore network, the larger was the effective tortuosity and the lower the permeability. Comparison of the three permeabilities and combined microscopic observations revealed that microfractures and laminae were the dominant gas transport channels. Importantly, the matrix permeability decreased exponentially with increasing water saturation, with water vapor adsorption experiments revealing that water occupation of pores and pore-throat spaces smaller than 10 nm in diameter was the main reason for this decrease in matrix permeability. Collectively, proposed method of evaluating effective permeability with an index for shale gas reservoirs is significant for sweet spot selection and production prediction of shale gas reservoirs around the globe.Cited as: Zhao, J., Sun, M., Pan, Z., Liu, B., Ostadhassan, M., Hu, Q. Effects of pore connectivity and water saturation on matrix permeability of deep gas shale. Advances in Geo-Energy Research, 2022, 6(1): 54-68. https://doi.org/10.46690/ager.2022.01.0

The effects of fear of missing out on social media posting preferences

Purpose: Fear of missing out (FOMO) has become a common phenomenon on social media. This study aims to examine how FOMO influences consumer preferences for posting about identity-relevant products on social media. Design/methodology/approach: In this research, three studies were conducted to explore the effects of FOMO in different real-life situations. Study 1 was conducted in a laboratory setting in China. Study 2 includes two experiments, one that was conducted in China and one in the USA. Study 3 was conducted in a workplace setting in China. Findings: The results of Study 1 indicate that when consumers experience FOMO, they prefer to post about identity-relevant (vs functional) products to a greater extent than usual. Study 2 examines the role of self-esteem and identifies self-presentation and the avoidance of social attention as underlying mechanisms. Thus, consumers with high (or low) self-esteem tend to be more motivated to present themselves positively (or to avoid social attention) when experiencing FOMO. Furthermore, Study 3 reveals the moderating role of supportive interactions; that is, the interaction between FOMO and consumer self-esteem is most likely to exert an effect when consumers receive many supportive interactions. Research limitations/implications: This research demonstrates that posting identity-relevant content on social media is a coping strategy that individuals may adopt when experiencing FOMO. Moreover, self-esteem can predict how individuals cope with FOMO by identifying self-presentation and avoidance of social attention as the mechanisms underlying effects. Although this research attempts to avoid interference from other factors between in the relationship FOMO and the control conditions, it seems possible that more socially relevant information may be presented in the FOMO condition. Practical implications: Because FOMO can be manipulated and posting types can be predicted, this research provides important implications for brands on how to create or post content to better engage consumers. Originality/value: This research supports the role of FOMO as a driver of on consumer posting preferences on social media.Peer reviewe

Establishment and phenotype verification of mouse oviductal epithelial organoids

Objective·To establish a culture system of oviductal epithelial organoids from wild type (WT) mice and miR-34b/c-/- and miR-449-/- double knockout (dKO) mice, and verify the phenotypes.Methods·The oviduct epithelial cells of WT mice and dKO mice were isolated and purified by enzyme digestion and differential adhesion method, and the purity of the isolated oviduct epithelial cells was identified by immunofluorescence staining. The numbers, growth rates and sizes of oviductal epithelial organoids between WT mice and dKO mice were compared by counting and diameter measurement. Hematoxylin-eosin (H-E) staining and transmission electron microscope (TEM) were used to observe the morphology and structure of the oviductal epithelial organoids. The proportions of ciliated cells and secretory cells in the oviductal epithelial organoids from WT mice and dKO mice were observed and counted by immunofluorescence staining. Immunohistochemistry (IHC), real-time quantitative PCR (RT-qPCR) and Western blotting were used to observe the expression levels of marker genes of ciliated cells and secretory cells in the oviductal epithelial organoids.Results·The purity of the isolated and purified oviduct epithelial cells was high. Compared with the organoids from WT mice, the oviductal epithelial organoids from dKO mice grew faster and larger, and were more in number. But they developed more slowly than those from WT mice, as the invaginations of the dKO mice organoids appeared on the 28th day of culture, while the WT mice organoids exhibited the same structures on the 16th day. The oviductal epithelial organoids showed similar structures as those of the oviduct in vivo under hematoxylin-eosin (H-E) staining and TEM. Immunofluorescence staining showed that the ciliated cells of oviductal epithelial organoids from dKO mice were significantly reduced and the secretory cells were significantly increased (both P<0.05). IHC showed that the molecular expression patterns of the oviductal epithelial organoids were consistent with those of the oviducts in vivo, i.e. the expression levels of ciliated cell markers acetylated α-tubulin (Ac-α-tubulin) and forkhead box J1 (FOXJ1) decreased, and the expression level of the secretory cell marker paired box 8 (PAX8) increased. RT-qPCR showed that the mRNA levels of Foxj1 and tubulin β class Ⅳa (Tubb4a) decreased (both P<0.05), while Pax8 increased in the oviductal epithelial organoids of dKO mice (P<0.05). Western blotting results showed that the protein expression level of FOXJ1 in the organoids of dKO mice significantly decreased, while the expression of PAX8 significantly increased (both P<0.05).Conclusion·The culture system of oviductal epithelial organoids of WT mice and dKO mice are successfully constructed, which can simulate the phenotypes of mouse oviduct in vivo

Privacy-Preserving Aggregation in Federated Learning: A Survey

Over the recent years, with the increasing adoption of Federated Learning (FL) algorithms and growing concerns over personal data privacy, Privacy-Preserving Federated Learning (PPFL) has attracted tremendous attention from both academia and industry. Practical PPFL typically allows multiple participants to individually train their machine learning models, which are then aggregated to construct a global model in a privacy-preserving manner. As such, Privacy-Preserving Aggregation (PPAgg) as the key protocol in PPFL has received substantial research interest. This survey aims to fill the gap between a large number of studies on PPFL, where PPAgg is adopted to provide a privacy guarantee, and the lack of a comprehensive survey on the PPAgg protocols applied in FL systems. In this survey, we review the PPAgg protocols proposed to address privacy and security issues in FL systems. The focus is placed on the construction of PPAgg protocols with an extensive analysis of the advantages and disadvantages of these selected PPAgg protocols and solutions. Additionally, we discuss the open-source FL frameworks that support PPAgg. Finally, we highlight important challenges and future research directions for applying PPAgg to FL systems and the combination of PPAgg with other technologies for further security improvement.Comment: 20 pages, 10 figure

Comprehensive summary of solid oxide fuel cell control : a state-of-the-art review

Hydrogen energy is a promising renewable resource for the sustainable development of society. As a key member of the fuel cell (FC) family, the solid oxide fuel cell (SOFC) has attracted a lot of attention because of characteristics such as having various sources as fuel and high energy conversion efficiency, and being pollution-free. SOFC is a highly coupled, nonlinear, and multivariable complex system, and thus it is very important to design an appropriate control strategy for an SOFC system to ensure its safe, reliable, and efficient operation. This paper undertakes a comprehensive review and detailed summary of the state-of-the-art control approaches of SOFC. These approaches are divided into eight categories of control: proportional integral differential (PID), adaptive (APC), robust, model predictive (MPC), fuzzy logic (FLC), fault-tolerant (FTC), intelligent and observer-based. The SOFC control approaches are carefully evaluated in terms of objective, design, application/scenario, robustness, complexity, and accuracy. Finally, five perspectives are proposed for future research directions

Mechanisms of traditional Chinese medicine overcoming of radiotherapy resistance in breast cancer

Breast cancer stands as the most prevalent malignancy among women, with radiotherapy serving as a primary treatment modality. Despite radiotherapy, a subset of breast cancer patients experiences local recurrence, attributed to the intrinsic resistance of tumors to radiation. Therefore, there is a compelling need to explore novel approaches that can enhance cytotoxic effects through alternative mechanisms. Traditional Chinese Medicine (TCM) and its active constituents exhibit diverse pharmacological actions, including anti-tumor effects, offering extensive possibilities to identify effective components capable of overcoming radiotherapy resistance. This review delineates the mechanisms underlying radiotherapy resistance in breast cancer, along with potential candidate Chinese herbal medicines that may sensitize breast cancer cells to radiotherapy. The exploration of such herbal interventions holds promise for improving therapeutic outcomes in the context of breast cancer radiotherapy resistance

Defense Responses to Short-term Hypoxia and Seawater Acidification in the Thick Shell Mussel Mytilus coruscus

The rising anthropogenic atmospheric CO2 results in the reduction of seawater pH, namely ocean acidification (OA). In East China Sea, the largest coastal hypoxic zone was observed in the world. This region is also strongly impacted by ocean acidification as receiving much nutrient from Changjiang and Qiantangjiang, and organisms can experience great short-term natural variability of DO and pH in this area. In order to evaluate the defense responses of marine mussels under this scenario, the thick shell mussel Mytilus coruscus were exposed to three pH/pCO2 levels (7.3/2800 μatm, 7.7/1020 μatm, 8.1/376 μatm) at two dissolved oxygen concentrations (DO, 2.0, 6.0 mg L−1) for 72 h. Results showed that byssus thread parameters, such as the number, diameter, attachment strength and plaque area were reduced by low DO, and shell-closing strength was significantly weaker under both hypoxia and low pH conditions. Expression patterns of genes related to mussel byssus protein (MBP) were affected by hypoxia. Generally, hypoxia reduced MBP1 and MBP7 expressions, but increased MBP13 expression. In conclusion, both hypoxia and low pH induced negative effects on mussel defense responses, with hypoxia being the main driver of change. In addition, significant interactive effects between pH and DO were observed on shell-closing strength. Therefore, the adverse effects induced by hypoxia on the defense of mussels may be aggravated by low pH in the natural environments