57 research outputs found

    Fast Model Debias with Machine Unlearning

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    Recent discoveries have revealed that deep neural networks might behave in a biased manner in many real-world scenarios. For instance, deep networks trained on a large-scale face recognition dataset CelebA tend to predict blonde hair for females and black hair for males. Such biases not only jeopardize the robustness of models but also perpetuate and amplify social biases, which is especially concerning for automated decision-making processes in healthcare, recruitment, etc., as they could exacerbate unfair economic and social inequalities among different groups. Existing debiasing methods suffer from high costs in bias labeling or model re-training, while also exhibiting a deficiency in terms of elucidating the origins of biases within the model. To this respect, we propose a fast model debiasing framework (FMD) which offers an efficient approach to identify, evaluate and remove biases inherent in trained models. The FMD identifies biased attributes through an explicit counterfactual concept and quantifies the influence of data samples with influence functions. Moreover, we design a machine unlearning-based strategy to efficiently and effectively remove the bias in a trained model with a small counterfactual dataset. Experiments on the Colored MNIST, CelebA, and Adult Income datasets along with experiments with large language models demonstrate that our method achieves superior or competing accuracies compared with state-of-the-art methods while attaining significantly fewer biases and requiring much less debiasing cost. Notably, our method requires only a small external dataset and updating a minimal amount of model parameters, without the requirement of access to training data that may be too large or unavailable in practice

    5-Fluorouracil targets thymidylate synthase in the selective suppression of TH17 cell differentiation

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    While it is well established that treatment of cancer patients with 5-Fluorouracil (5-FU) can result in immune suppression, the exact function of 5-FU in the modulation of immune cells has not been fully established. We found that low dose 5-FU selectively suppresses TH17 and TH1 cell differentiation without apparent effect on Treg, TH2, and significantly suppresses thymidylate synthase (TS) expression in TH17 and TH1 cells but has a lesser effect in tumor cells and macrophages. Interestingly, the basal expression of TS varies significantly between T helper phenotypes and knockdown of TS significantly impairs TH17 and TH1 cell differentiation without affecting the differentiation of either Treg or TH2 cells. Finally, low dose 5-FU is effective in ameliorating colitis development by suppressing TH17 and TH1 cell development in a T cell transfer colitis model. Taken together, the results highlight the importance of the anti-inflammatory functions of low dose 5-FU by selectively suppressing TH17 and TH1 immune responses

    Geometry and singularities of spatial and spherical curves

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    Mode of access: World Wide Web.Thesis (Ph. D.)--University of Hawaii at Manoa, 2004.Includes bibliographical references (leaves 113-114).Electronic reproduction.Also available by subscription via World Wide Webvii, 114 leaves, bound ill. 29 cmIn the first part of this dissertation the spherical evolute, the spherical involute, the spherical orthotomic and the spherical antiorthotomic are investigated and their local diffeomorphic types are determined. The concept of the spherical conic is introduced. It is proven that the incident angle and reflection angle are equal for the spherical conic. The necessary and sufficient conditions for the spherical conic to be a circle are given. In the second part of this dissertation the ruled surfaces of normals and binormals of a regular space curve are locally classified under the left-right action according to the types of the curve. For this purpose some results are obtained on the relationship of the powers of terms in the Taylor series of an invertible function and its inverse

    Attribute-Based Privacy-Preserving Data Sharing for Dynamic Groups in Cloud Computing

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    Extensive Metabolite Profiling in the Unexploited Organs of Black Tiger for Their Potential Valorization in the Pharmaceutical Industry

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    Black tiger (Kadsura coccinea (Lem.)) has been reported to hold enormous pharmaceutical potential. The fruit and rhizome of black tiger are highly exploited in the pharmaceutical and other industries. However, the most important organs from the plant such as the leaf and stem are considered biowastes mainly because a comprehensive metabolite profile has not been reported in these organs. Knowledge of the metabolic landscape of the unexploited black tiger organs could help identify and isolate important compounds with pharmaceutical and nutritional values for a better valorization of the species. In this study, we used a widely targeted metabolomics approach to profile the metabolomes of the K. coccinea leaf (KL) and stem (KS) and compared them with the root (KR). We identified 642, 650 and 619 diverse metabolites in KL, KS and KR, respectively. A total of 555 metabolites were mutually detected among the three organs, indicating that the leaf and stem organs may also hold potential for medicinal, nutritional and industrial applications. Most of the differentially accumulated metabolites between organs were enriched in flavone and flavonol biosynthesis, phenylpropanoid biosynthesis, arginine and proline metabolism, arginine biosynthesis, tyrosine metabolism and 2-oxocarboxylic acid metabolism pathways. In addition, several important organ-specific metabolites were detected in K. coccinea. In conclusion, we provide extensive metabolic information to stimulate black tiger leaf and stem valorization in human healthcare and food

    Classification of (2,2)-stable unfoldings of map germs with codimensions ≤ 4

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    Altered Amplitude of Low-Frequency Fluctuations and Degree Centrality in Patients with Acute Subjective Tinnitus: A Resting-State Functional Magnetic Resonance Imaging Study

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    Background: The difference in spontaneous brain activity between acute subjective tinnitus patients (with or without hearing loss) and control participants was explored using the amplitude of low-frequency fluctuations and degree centrality methods through resting-state functional magnetic resonance imaging. The study aimed to provide an objective basis for clinical diagnosis and pathogenesis of patients with acute subjective tinnitus. Methods: Fourteen acute subjective tinnitus (AST) patients with hearing loss (AST-HL), 6 AST patients with no hearing loss (AST-NHL), and 14 healthy controls (HCs) with age, sex, and education status matched were recruited for this study. Resting-state functional magnetic resonance imaging (fMRI) examinations were performed in a resting state and the amplitude of low-frequency fluctuations (ALFF) and degree centrality (DC) values of each group were acquired. Statistical analysis was performed to assess the ALFF and DC values of different brain areas of the participants (AST-HL and AST-NHL were compared with HCs, but AST-HL and AST-NHL were not). Results: Patients with acute subjective tinnitus and hearing loss showed a significantly increased amplitude of low-frequency fluctuation values in the left middle temporal gyrus and bilateral frontal gyrus/marginal lobe/cingulate gyrus but a decreased amplitude of low-frequency fluctuations values in the bilateral superior temporal gyrus/anterior cerebellar lobe in comparison with healthy controls. The amplitude of low-frequency fluctuation values of patients with acute subjective tinnitus and hearing loss in the right posterior lobe of the cerebellum, bilateral temporal gyrus, bilateral lenticular nucleus, bilateral frontal gyrus, right inferior occipital gyrus, were higher, but were significantly lower in the bilateral anterior lobe of cerebellum/superior temporal gyrus and left posterior cerebellar lobe as compared with those of healthy controls. Degree centrality values in the healthy controls group were increased in the right superior marginal gyrus and decreased in the right thalamus in patients with acute subjective tinnitus and hearing loss, while patients with acute subjective tinnitus with no hearing loss presented significantly higher degree centrality values in the left frontal lobe and lower degree centrality values in the left center rear return. Conclusions: Aberrant amplitude of low-frequency fluctuations and values exist in various brain regions, indicating abnormal spontaneous brain activity in both acute subjective tinnitus and hearing loss and acute subjective tinnitus no hearing loss patients. The pathogenesis of acute subjective tinnitus may be related to abnormalities in both the auditory cortex and nonauditory cortex. These findings provide more evidence to help clarify the neuronal symptoms of acute subjective tinnitus patients

    Experimental study on the acoustic wave propagation characteristics of bedding shales under changes in temperature and pressure

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    To determine the acoustic wave propagation characteristics of bedded shales under different confining pressures and temperatures, shales from the Longmaxi Formation in the Sichuan Basin are taken as research objects. Based on ultrasonic experiments, the acoustic wave propagation properties of shales with different bedding angles are investigated. The effects of the confining pressure, temperature, and bedding angle on the acoustic velocity, attenuation coefficient, and acoustic anisotropy coefficient are analyzed. Based on the results, an acoustic velocity prediction model for bedded shales considering the confining pressure, temperature, and bedding angle is established. The experiments show that, for confining pressures from 0 to 50 MPa and temperatures from 20 to 100 °C, the acoustic velocity of the shales increases with increasing confining pressure and decreases with increasing temperature and bedding angle. The attenuation coefficient of the shales exhibits a decreasing trend with increasing confining pressure, but increases with increasing temperature and bedding angle. The acoustic anisotropy coefficient of shale gradually decreases with increasing confining pressure, but increases with increasing temperature and bedding angle. The acoustic velocity prediction model for in-situ bedded shales established in this study has a high level of accuracy. The relationship between the acoustic anisotropy coefficient and the bedding angle is satisfied by a binomial equation. The relationship between the acoustic anisotropy coefficient and the confining pressure and temperature follows a binary linear logarithmic equation
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