Quantifying the Impact of Label Noise on Federated Learning

Federated Learning (FL) is a distributed machine learning paradigm where clients collaboratively train a model using their local (human-generated) datasets. While existing studies focus on FL algorithm development to tackle data heterogeneity across clients, the important issue of data quality (e.g., label noise) in FL is overlooked. This paper aims to fill this gap by providing a quantitative study on the impact of label noise on FL. We derive an upper bound for the generalization error that is linear in the clients' label noise level. Then we conduct experiments on MNIST and CIFAR-10 datasets using various FL algorithms. Our empirical results show that the global model accuracy linearly decreases as the noise level increases, which is consistent with our theoretical analysis. We further find that label noise slows down the convergence of FL training, and the global model tends to overfit when the noise level is high.Comment: Accepted by The AAAI 2023 Workshop on Representation Learning for Responsible Human-Centric A

Metastasis-on-a-chip mimicking the progression of kidney cancer in the liver for predicting treatment efficacy.

Metastasis is one of the most important factors that lead to poor prognosis in cancer patients, and effective suppression of the growth of primary cancer cells in a metastatic site is paramount in averting cancer progression. However, there is a lack of biomimetic three-dimensional (3D) in vitro models that can closely mimic the continuous growth of metastatic cancer cells in an organ-specific extracellular microenvironment (ECM) for assessing effective therapeutic strategies. Methods: In this metastatic tumor progression model, kidney cancer cells (Caki-1) and hepatocytes (i.e., HepLL cells) were co-cultured at an increasing ratio from 1:9 to 9:1 in a decellularized liver matrix (DLM)/gelatin methacryloyl (GelMA)-based biomimetic liver microtissue in a microfluidic device. Results:Via this model, we successfully demonstrated a linear anti-cancer relationship between the concentration of anti-cancer drug 5-Fluorouracil (5-FU) and the percentage of Caki-1 cells in the co-culture system (R2 = 0.89). Furthermore, the Poly(lactide-co-glycolide) (PLGA)-poly(ethylene glycol) (PEG)-based delivery system showed superior efficacy to free 5-FU in killing Caki-1 cells. Conclusions: In this study, we present a novel 3D metastasis-on-a-chip model mimicking the progression of kidney cancer cells metastasized to the liver for predicting treatment efficacy. Taken together, our study proved that the tumor progression model based on metastasis-on-a-chip with organ-specific ECM would provide a valuable tool for rapidly assessing treatment regimens and developing new chemotherapeutic agents

Long-chain polyunsaturated fatty acid metabolism in carnivorous marine teleosts: insight into the profile of endogenous biosynthesis in golden pompano Trachinotus ovatus

Golden pompano Trachinotus ovatus is an important farmed carnivorous marine teleost. Although some enzymes for long-chain polyunsaturated fatty acids (LC-PUFA) biosynthesis have been identified, the ability of T. ovatus for endogenous biosynthesis is unknown. Here, we evaluated in vivo LC-PUFA synthesis in a 56-day culture experiment using six diets (D1-D6) formulated with linseed and soybean oils to produce dietary linolenic/linoleic acid (ALA/LA) ratios ranging from 0.14 to 2.20. The control diet (D0) used fish oil as lipid source. The results showed that, compared with the corresponding indeces of fish fed D0, the weight gain rate and specific growth rate, as well as the contents of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in tissues (liver, muscle, brain and eye) of D1-D6 groups were significantly lower (P < 0.05). These data suggested that T. ovatus could not synthesize LC-PUFA from C18 PUFA or such ability was very low. However, tissue levels of 20:4n-3 in fish fed diets D1-D6 were higher than that of D0 fish (P < 0.05), and positively correlated with dietary ALA/LA ratio, while levels of EPA showed no difference among the D1-D6 groups. These results indicated that Δ5 desaturation, required for the conversion of 20:4n-3 to EPA, may be lacking or very low, suggesting incomplete LC-PUFA biosynthesis ability in T. ovatus

Effects of different dietary oil sources on growth performance, antioxidant capacity and lipid deposition of juvenile golden pompano Trachinotus ovatus

Vegetable oils (VO) that are used to substitute fish oil in aquafeeds may affect, not only the fatty acid composition, but also lipid metabolism and distribution. The present study was designed to investigate this issue in juvenile golden pompano Trachinotus ovatus fed eight diets formulated with typical VO with widely varying fatty acid compositions including coconut oil (CO), palm oil (PO), oil-tea camellia seed oil (OTO), olive oil (OO), canola oil (CNO), peanut oil (PNO), linseed oil (LO) and perilla oil (PFO), in comparison with fish fed fish oil (FO). After the 8-week feeding trial, fish fed the CO diet had the highest growth performance, and higher general antioxidant capacities in serum and liver than in fish fed the other VO. The crude lipid content in whole body and expression levels of fas were lower in fish fed the FO, PFO and LO diets, while lipid contents and expression levels of scd were higher in fish fed the OTO and PNO diets. Other than fish fed the PFO diet, the total lipid contents of liver in other fish fed the other VO diets were higher than that in fish fed the FO diet, with the highest contents in fish fed the OTO and OO diets. The expression levels of genes involved in fatty acid catabolism and transport, namely pparα, cpt1 and apoB100, were higher in fish fed diet PFO than in fish fed the other diets. Comparing the fatty acid compositions of tissues and diets showed that 18:1n-9, 18:3n-3 (ALA) and 22:6n-3 (DHA) were preferentially deposited in tissues of pompano, with DHA preferentially deposited in polar lipids rather than neutral lipids. However, excessive dietary ALA in PFO did not lead to increased deposition of ALA, but increased liver lipid content. The present study showed that dietary lipid sources had significant influences on growth performance and antioxidant capacity, as well as on lipid deposition. Low dietary 18:1n-9, high n-3 long-chain polyunsaturated fatty acids and an appropriate ratio of ALA/LNA (18,2n-6) could reduce lipid deposition in pompano tissues, especially liver

Development and preliminary verification of a 1D–3D coupled flow and heat transfer model of OTSG

Introduction: A simulation model was developed by coupling a one-dimensional (1D) system code and 3D CFD software, to analyze the three-dimensional (3D) flow and heat transfer characteristics of the once-through steam generator (OTSG).Methods: The shell side of the OTSG was simulated by FLUENT, and the tube side was simulated by the system code LOCUST. Through spatial mapping, the 1D and 3D simulations were coupled along the outer wall of the OTSG's helically coiled tubes.Results and Discussion: This coupling method enabled the acquisition of high-resolution flow and heat transfer characteristics of the OTSG, and the error of heat flux calculation result by the coupled model is within 15%. Through coupling simulation analysis of the prototype OTSG, it was found that the inlet and outlet temperature difference reached as high as 150°C. The unevenness of the radial temperature distribution increased along the flow direction, and the wake swing effect caused by the sweeping flow of the tube bundle at the exit position was evident. The results of this study provide reference and a coupled simulation method for the engineering design and thermal-hydraulic characteristics analysis of OTSG

Porcine reproductive and respiratory syndrome virus inhibits MARC-145 proliferation via inducing apoptosis and G2/M arrest by activation of Chk/Cdc25C and p53/p21 pathway

Abstract Porcine reproductive and respiratory syndrome virus(PRRSV) is an important immunosuppressive virus which can suppresses infected cells proliferation. In this work, we examined PRRSV ability to manipulate cell cycle progression of MARC-145 cells and explored the potential molecular mechanisms. The results showed that PRRSV infection imposed a growth-inhibitory effect on MARC-145 cells by inducing cell cycle arrest at G2/M phase. This arrest was due to the significant decrease of Cdc2-cyclinB1 complex activity in PRRSV-infected cells and the activity reduction was a result of Cdc2 Tyr15 phosphorylation and the accumulation of Cdc2 and cyclinB1 in the nucleus. Not only elevated Wee1 and Myt1 expression and inactivated Cdc25C, but also increase of p21 and 14–3-3σ in a p53-dependent manner caused the inhibitory Tyr15 phosphorylation of Cdc2. PRRSV infection also activated Chk1. Our data suggest PRRSV infection induces G2/M arrest via various molecular regulatory mechanisms. These results provide a new insights for PRRSV pathogenesis

Porcine reproductive and respiratory syndrome virus inhibits MARC-145 proliferation via inducing apoptosis and G2/M arrest by activation of Chk/Cdc25C and p53/p21 pathway

Abstract Porcine reproductive and respiratory syndrome virus(PRRSV) is an important immunosuppressive virus which can suppresses infected cells proliferation. In this work, we examined PRRSV ability to manipulate cell cycle progression of MARC-145 cells and explored the potential molecular mechanisms. The results showed that PRRSV infection imposed a growth-inhibitory effect on MARC-145 cells by inducing cell cycle arrest at G2/M phase. This arrest was due to the significant decrease of Cdc2-cyclinB1 complex activity in PRRSV-infected cells and the activity reduction was a result of Cdc2 Tyr15 phosphorylation and the accumulation of Cdc2 and cyclinB1 in the nucleus. Not only elevated Wee1 and Myt1 expression and inactivated Cdc25C, but also increase of p21 and 14–3-3σ in a p53-dependent manner caused the inhibitory Tyr15 phosphorylation of Cdc2. PRRSV infection also activated Chk1. Our data suggest PRRSV infection induces G2/M arrest via various molecular regulatory mechanisms. These results provide a new insights for PRRSV pathogenesis

Leakage current simulations of Low Gain Avalanche Diode with improved Radiation Damage Modeling

We report precise TCAD simulations of IHEP-IME-v1 Low Gain Avalanche Diode (LGAD) calibrated by secondary ion mass spectroscopy (SIMS). Our setup allows us to evaluate the leakage current, capacitance, and breakdown voltage of LGAD, which agree with measurements' results before irradiation. And we propose an improved LGAD Radiation Damage Model (LRDM) which combines local acceptor removal with global deep energy levels. The LRDM is applied to the IHEP-IME-v1 LGAD and able to predict the leakage current well at -30 $^{\circ}$C after an irradiation fluence of $\Phi_{eq}=2.5 \times 10^{15} ~n_{eq}/cm^{2}$. The charge collection efficiency (CCE) is under development

Study of the Spatio-Temporal Variation of Agricultural Sustainability at National and Provincial Levels in China

As an important pillar of human civilization, the development of agriculture has gradually become the focus of the international community to solve the development dilemma and promote the implementation of the global Sustainable Development Goals (SDGs). Agricultural sustainability issues are widely addressed in scientific literature and various reports by international organizations. However, there are some problems in the existing studies, such as the design of agricultural sustainable development evaluation indicators does not consider the differences in development stages and data statistical capacity of various countries, and the research depth of spatial and temporal change of agricultural sustainable development is insufficient. Agriculture has become a bottleneck for the world and China to achieve the SDGs. Based on the global indicator framework of the Sustainable Development Goals and comprehensive consideration of agricultural development common problems and regional characteristics, this work has established a basic index library consisting of 86 indicators to evaluate the agricultural sustainable development in China and provide the basis for the assessment in different regions. In the indicator optimization process, having considered the development stage of China, the basic characteristics of agriculture, data availability, and reliability, we determined an evaluation index system of China’s agricultural sustainable development that includes 25 specific indicators. The constant elasticity of substitution (CES) model was used to assess the temporal and spatial changes in agricultural sustainability in China at the national, regional, and provincial levels. The results showed that China’s Agricultural Sustainable Development Index (ASDI) score increased from 44.76 in 2011 to 59.22 in 2021, and the ASDI scores of all agricultural regions and provinces also increased to varying degrees. In terms of goal scores, SDG2, SDG6, SDG7, SDG8, SDG9, and SDG12 all exhibited an overall upward trend, in which SDG6 performed the best, and SDG2 performed the worst, scoring 84.76 and 43.05 in 2021, respectively. This paper will provide a basis for systematically evaluating the progress of agricultural sustainable development goals and accurately identifying unsustainable problems in agricultural development to help China implement the 2030 Agenda for Sustainable Development