PrivGraph: Differentially Private Graph Data Publication by Exploiting Community Information

Graph data is used in a wide range of applications, while analyzing graph data without protection is prone to privacy breach risks. To mitigate the privacy risks, we resort to the standard technique of differential privacy to publish a synthetic graph. However, existing differentially private graph synthesis approaches either introduce excessive noise by directly perturbing the adjacency matrix, or suffer significant information loss during the graph encoding process. In this paper, we propose an effective graph synthesis algorithm PrivGraph by exploiting the community information. Concretely, PrivGraph differentially privately partitions the private graph into communities, extracts intra-community and inter-community information, and reconstructs the graph from the extracted graph information. We validate the effectiveness of PrivGraph on six real-world graph datasets and seven commonly used graph metrics.Comment: To Appear in the 32nd USENIX Security Symposiu

ORL-AUDITOR: Dataset Auditing in Offline Deep Reinforcement Learning

Data is a critical asset in AI, as high-quality datasets can significantly improve the performance of machine learning models. In safety-critical domains such as autonomous vehicles, offline deep reinforcement learning (offline DRL) is frequently used to train models on pre-collected datasets, as opposed to training these models by interacting with the real-world environment as the online DRL. To support the development of these models, many institutions make datasets publicly available with opensource licenses, but these datasets are at risk of potential misuse or infringement. Injecting watermarks to the dataset may protect the intellectual property of the data, but it cannot handle datasets that have already been published and is infeasible to be altered afterward. Other existing solutions, such as dataset inference and membership inference, do not work well in the offline DRL scenario due to the diverse model behavior characteristics and offline setting constraints. In this paper, we advocate a new paradigm by leveraging the fact that cumulative rewards can act as a unique identifier that distinguishes DRL models trained on a specific dataset. To this end, we propose ORL-AUDITOR, which is the first trajectory-level dataset auditing mechanism for offline RL scenarios. Our experiments on multiple offline DRL models and tasks reveal the efficacy of ORL-AUDITOR, with auditing accuracy over 95% and false positive rates less than 2.88%. We also provide valuable insights into the practical implementation of ORL-AUDITOR by studying various parameter settings. Furthermore, we demonstrate the auditing capability of ORL-AUDITOR on open-source datasets from Google and DeepMind, highlighting its effectiveness in auditing published datasets. ORL-AUDITOR is open-sourced at https://github.com/link-zju/ORL-Auditor.Comment: To appear in the Network and Distributed System Security Symposium (NDSS) 2024, San Diego, CA, US

Regulation of gene expression by FSP27 in white and brown adipose tissue

<p>Abstract</p> <p>Background</p> <p>Brown and white adipose tissues (BAT and WAT) play critical roles in controlling energy homeostasis and in the development of obesity and diabetes. The mouse Fat-Specific protein 27 (FSP27), a member of the cell death-inducing DFF45-like effector (CIDE) family, is expressed in both BAT and WAT and is associated with lipid droplets. Over-expression of FSP27 promotes lipid storage, whereas <it>FSP27 </it>deficient mice have improved insulin sensitivity and are resistant to diet-induced obesity. In addition, <it>FSP27</it>-deficient white adipocytes have reduced lipid storage, smaller lipid droplets, increased mitochondrial activity and a higher expression of several BAT-selective genes. To elucidate the molecular mechanism by which FSP27 controls lipid storage and gene expression in WAT and BAT, we systematically analyzed the gene expression profile of <it>FSP27-</it>deficient WAT by microarray analysis and compared the expression levels of a specific set of genes in WAT and BAT by semi-quantitative real-time PCR analysis.</p> <p>Results</p> <p>BAT-selective genes were significantly up-regulated, whereas WAT-selective genes were down-regulated in the WAT of <it>FSP27-</it>deficient mice. The expression of the BAT-selective genes was also dramatically up-regulated in the WAT of <it>leptin/FSP27 </it>double deficient mice. In addition, the expression levels of genes involved in multiple metabolic pathways, including oxidative phosphorylation, the TCA cycle, fatty acid synthesis and fatty acid oxidation, were increased in the <it>FSP27-</it>deficient WAT. In contrast, the expression levels for genes involved in extracellular matrix remodeling, the classic complement pathway and TGF-β signaling were down-regulated in the <it>FSP27-</it>deficient WAT. Most importantly, the expression levels of regulatory factors that determine BAT identity, such as CEBPα/β, PRDM16 and major components of the cAMP pathway, were markedly up-regulated in the WAT of <it>FSP27-</it>deficient mice. The expression levels of these regulatory factors were also up-regulated in <it>leptin/FSP27 </it>double deficient mice. Interestingly, distinct gene expression profiles were observed in the BAT of <it>FSP27-</it>deficient mice. Taken together, these data suggest that the WAT of <it>FSP27-</it>deficient mice have a gene expression profile similar to that of BAT.</p> <p>Conclusions</p> <p>FSP27 acts as a molecular determinant that controls gene expression for a diversity of metabolic and signaling pathways and, in particular, the expression of regulatory factors, including CEBPα/β, PRDM16 and components of the cAMP signaling pathway, that control the identity of WAT and BAT.</p

Effect of Sow Intestinal Flora on the Formation of Endometritis

Endometritis is the main cause of decreased reproductive performance of sows, while one of the most important factors in the etiology of sow endometritis is an aberration of birth canal microbiota. Therefore, people began to pay attention to the microbiota structure and composition of the birth canal of sows with endometritis. Interestingly, we found that the risk of endometritis was increased in the sows with constipation in clinical practice, which may imply that the intestinal flora is related to the occurrence of endometritis. Therefore, understanding the relationship between birth canal microbiota and intestinal microbiota of the host has become exceptionally crucial. In this study, the microbiota of birth canal secretions and fresh feces of four healthy and four endometritis sows were analyzed via sequencing the V3 + V4 region of bacterial 16S ribosomal (rDNA) gene. The results showed a significant difference between endometritis and healthy sows birth canal flora in composition and abundance. Firmicutes (74.36%) and Proteobacteria were the most dominant phyla in birth canal microbiota of healthy sows. However, the majority of beneficial bacteria that belonging to Firmicutes phylum (e.g., Lactobacillus and Enterococcus) declined in endometritis sow. The abundance of Porphyromonas, Clostridium sensu stricto 1, Streptococcus, Fusobacterium, Actinobacillus, and Bacteroides increased significantly in the birth canal microbiota of endometritis sows. Escherichia–Shigella and Bacteroides were the common genera in the birth canal and intestinal flora of endometritis sows. The abundance of Escherichia–Shigella and Bacteroides in the intestines of sows suffering from endometritis were significantly increased than the intestinal microbiota of the healthy sows. We speculated that some intestinal bacteria (such as Escherichia–Shigella and Bacteroides) might be bound up with the onset of sow endometritis based on intestinal microbiota analysis in sows with endometritis and healthy sows. The above results can supply a theoretical basis to research the pathogenesis of endometritis and help others understand the relationship with the microbiota of sow's birth canal and gut

AHEAD: Adaptive Hierarchical Decomposition for Range Query under Local Differential Privacy

For protecting users' private data, local differential privacy (LDP) has been leveraged to provide the privacy-preserving range query, thus supporting further statistical analysis. However, existing LDP-based range query approaches are limited by their properties, i.e., collecting user data according to a pre-defined structure. These static frameworks would incur excessive noise added to the aggregated data especially in the low privacy budget setting. In this work, we propose an Adaptive Hierarchical Decomposition (AHEAD) protocol, which adaptively and dynamically controls the built tree structure, so that the injected noise is well controlled for maintaining high utility. Furthermore, we derive a guideline for properly choosing parameters for AHEAD so that the overall utility can be consistently competitive while rigorously satisfying LDP. Leveraging multiple real and synthetic datasets, we extensively show the effectiveness of AHEAD in both low and high dimensional range query scenarios, as well as its advantages over the state-of-the-art methods. In addition, we provide a series of useful observations for deploying AHEAD in practice

Tip60-mediated lipin 1 acetylation and ER translocation determine triacylglycerol synthesis rate

人类遗传学家James V. Neel在1962年首次提出了“节俭基因”这一概念，认为现今人类导致包括肥胖症、糖尿病和高血压等代谢障碍的基因是因为生理系统为了适应远古环境食物富足和食物缺乏的周期性改变而筛选出的，可以让远古人类在食物富足的短暂时期中快速增肥，以应对随时将到来的食物缺乏时期。这类基因在当时环境下有很大的优越性，但对于当今食物富足的社会则截然相反。这篇论文中林圣彩教授团队揭示了乙酰转移酶TIP60通过乙酰化脂肪合成途径的代谢酶lipin 1并促进其向内质网转运，从而提高脂肪合成速率，揭示了TIP60作为一个“节俭基因”的功能和作用机制。该研究阐明了脂肪合成途径中首个受蛋白质乙酰化修饰调控的途径，揭示了TIP60作为经典转录调控因子之外的又一重要生物学功能，为开发防治肥胖症及其相关代谢紊乱疾病提供了新的药物作用靶点。博士后李阳、博士生宋林涛和硕士生孙玉是该论文的共同第一作者。【Abstract】Obesity is characterized by excessive fatty acid conversion to triacylglycerols (TAGs) in adipose tissues. However, how signaling networks sense fatty acids and connect to the stimulation of lipid synthesis remains elusive. Here, we show that homozygous knock-in mice carrying a point mutation at the Ser86 phosphorylation site of acetyltransferase Tip60 (Tip60SA/SA) display remarkably reduced body fat mass, and Tip60SA/SA females fail to nurture pups to adulthood due to severely reduced milk TAGs. Mechanistically, fatty acids stimulate Tip60-dependent acetylation and endoplasmic reticulum translocation of phosphatidic acid phosphatase lipin 1 to generate diacylglycerol for TAG synthesis, which is repressed by deacetylase Sirt1. Inhibition of Tip60 activity strongly blocks fatty acid-induced TAG synthesis while Sirt1 suppression leads to increased adiposity. Genetic analysis of loss-of-function mutants in Saccharomyces cerevisiae reveals a requirement of ESA1, yeast ortholog of Tip60, in TAG accumulation. These findings uncover a conserved mechanism linking fatty acid sensing to fat synthesis.This work was supported by grants from the National Natural Science Foundation of China (#31690101, #31430094, #31600961 and #31571214) and National Key Research and Development Project of China (2016YFA0502001). 该研究受到了国家自然科学基金和中国国家重点研发计划项目的资助

Metagenomics of Wastewater Influent from Wastewater Treatment Facilities across Ontario in the Era of Emerging SARS-CoV-2 Variants of Concern

We report metagenomic sequencing analyses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in composite wastewater influent from 10 regions in Ontario, Canada, during the transition between Delta and Omicron variants of concern. The Delta and Omicron BA.1/BA.1.1 and BA.2-defining mutations occurring in various frequencies were reported in the consensus and subconsensus sequences of the composite samples

Sonosensitive Phase-Changeable Nanoparticle Mediated Enhanced Chemotherapy in Prostate Cancer by Low-Intensity Focused Ultrasound

Prostate cancer (PCa) is one of the most common cancer types. Early detection of PC offers the best chance of successful treatment. A noninvasive, image-guided therapy mediated by targeted nanoparticles (NPs) has the potential to improve the efficacy and safety of cancer therapies. Herein, we report a sonosensitive nanoparticle modified with anti-PSMA (prostate-specific membrane antigen) antibodies to activate target prostate tumors. These nanoparticles (PFP@IR780@PTX@liposome NPs) were co-loaded with the chemotherapeutic agent docetaxel and the sonosensitizer IR780, as well as phase-changeable perfluorocarbon (PFC) liquids. The liquid–gas phase change could be induced by low-intensity focused ultrasound (LIFU) in vitro. We found that the PFP@IR780@PTX@liposome NPs can specifically accumulate in prostate tumors after LIFU irradiation, as monitored by ultrasound and photoacoustic imaging. Meanwhile, docetaxel was controllably released from the nanoparticles to achieve enhanced chemotherapeutic therapy in vivo. These sonosensitive phase-changeable NPs can visually treat prostate cancers effectively and have a clinical potential

AHEAD: Adaptive Hierarchical Decomposition for Range Query under Local Differential Privacy

For protecting users' private data, local differential privacy (LDP) has been leveraged to provide the privacy-preserving range query, thus supporting further statistical analysis. However, existing LDP-based range query approaches are limited by their properties, i.e., collecting user data according to a pre-defined structure. These static frameworks would incur excessive noise added to the aggregated data especially in the low privacy budget setting. In this work, we propose an Adaptive Hierarchical Decomposition (AHEAD) protocol, which adaptively and dynamically controls the built tree structure, so that the injected noise is well controlled for maintaining high utility. Furthermore, we derive a guideline for properly choosing parameters for AHEAD so that the overall utility can be consistently competitive while rigorously satisfying LDP. Leveraging multiple real and synthetic datasets, we extensively show the effectiveness of AHEAD in both low and high dimensional range query scenarios, as well as its advantages over the state-of-the-art methods. In addition, we provide a series of useful observations for deploying AHEAD in practice