A Riemannian Primal-dual Algorithm Based on Proximal Operator and its Application in Metric Learning

In this paper, we consider optimizing a smooth, convex, lower semicontinuous function in Riemannian space with constraints. To solve the problem, we first convert it to a dual problem and then propose a general primal-dual algorithm to optimize the primal and dual variables iteratively. In each optimization iteration, we employ a proximal operator to search optimal solution in the primal space. We prove convergence of the proposed algorithm and show its non-asymptotic convergence rate. By utilizing the proposed primal-dual optimization technique, we propose a novel metric learning algorithm which learns an optimal feature transformation matrix in the Riemannian space of positive definite matrices. Preliminary experimental results on an optimal fund selection problem in fund of funds (FOF) management for quantitative investment showed its efficacy.Comment: 8 pages, 2 figures, published as a conference paper in 2019 International Joint Conference on Neural Networks (IJCNN

Gene expression profiling of rat livers with Yin-deficiency-heat syndrome

AbstractObjectiveTo explore the nature of ”Yin internal heat caused by Yin-deficiency,” in terms of the theory of Traditional Chinese Medicine, by studying energy metabolism in rats with Yin-deficiency-heat syndrome and analyzing the gene expression profile of their livers.MethodsA Yin-deficiency-heat syndrome model was induced in rats using three Chinese medicinal herbs. Glycogen and triglycerides in blood plasma, and the enzyme activity of ATP in livers were measured colorimetrically. Triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone levels in blood plasma were also measured with enzyme linked immunosorbent assay. The gene expression profile of livers was detected with gene chip analysis. Differentially expressed genes were screened out and classified according to Gene Ontology. The accuracy of results were examined with reverse transcription-polymerase chain reaction.ResultsCompared with the control group, body weight (P<0.05) and hepatic glycogen (P<0.05) were significantly lower in the Yin-deficiency-heat syndrome group. Moreover, toe temperature (P< 0.01) and triglyceride (P<0.05), Na+−K+−ATPase (P< 0.01), Mg2+−ATPase (P<0.01), T3 (P<0.05), and T4 (P< 0.01) levels were significantly higher. There were 99 differentially expressed genes in livers from the Yin-deficiency-heat syndrome group. Genes were mainly related to sterol synthesis (Pc=0.0392), defense response (Pc=0.0448), and sterol metabolism (Pc=0.0533).ConclusionAbnormal expression genes in rats with Yin-deficiency-heat syndrome prompted the synthesis and metabolism of cholesterol, increased energy consumption, and reduced defense response. This gene expression might be the molecular mechanism underlying “internal heat caused by Yin-deficiency” in the rats with Yin-deficiency-heat syndrome

Enhanced fermentative performance under stresses of multiple lignocellulose-derived inhibitors by overexpression of a typical 2-Cys peroxiredoxin from Kluyveromyces marxianus

Additional file 1: Figure S1. Construction of overexpressing vector and subsequent verification. a) The schematic of overexpressing vector containing KmTPX1 gene and its own promoter. b) PCR and restriction enzyme digestion verification with a band of 1042 bp. c) Relative abundance of KmTPX1 overexpression in SC-His medium by real-time quantitative PCR technology

CIRS: Bursting Filter Bubbles by Counterfactual Interactive Recommender System

While personalization increases the utility of recommender systems, it also brings the issue of filter bubbles. E.g., if the system keeps exposing and recommending the items that the user is interested in, it may also make the user feel bored and less satisfied. Existing work studies filter bubbles in static recommendation, where the effect of overexposure is hard to capture. In contrast, we believe it is more meaningful to study the issue in interactive recommendation and optimize long-term user satisfaction. Nevertheless, it is unrealistic to train the model online due to the high cost. As such, we have to leverage offline training data and disentangle the causal effect on user satisfaction. To achieve this goal, we propose a counterfactual interactive recommender system (CIRS) that augments offline reinforcement learning (offline RL) with causal inference. The basic idea is to first learn a causal user model on historical data to capture the overexposure effect of items on user satisfaction. It then uses the learned causal user model to help the planning of the RL policy. To conduct evaluation offline, we innovatively create an authentic RL environment (KuaiEnv) based on a real-world fully observed user rating dataset. The experiments show the effectiveness of CIRS in bursting filter bubbles and achieving long-term success in interactive recommendation. The implementation of CIRS is available via https://github.com/chongminggao/CIRS-codes.Comment: 11 pages, 9 figure

Charge Measurement of Cosmic Ray Nuclei with the Plastic Scintillator Detector of DAMPE

One of the main purposes of the DArk Matter Particle Explorer (DAMPE) is to measure the cosmic ray nuclei up to several tens of TeV or beyond, whose origin and propagation remains a hot topic in astrophysics. The Plastic Scintillator Detector (PSD) on top of DAMPE is designed to measure the charges of cosmic ray nuclei from H to Fe and serves as a veto detector for discriminating gamma-rays from charged particles. We propose in this paper a charge reconstruction procedure to optimize the PSD performance in charge measurement. Essentials of our approach, including track finding, alignment of PSD, light attenuation correction, quenching and equalization correction are described detailedly in this paper after a brief description of the structure and operational principle of the PSD. Our results show that the PSD works very well and almost all the elements in cosmic rays from H to Fe are clearly identified in the charge spectrum.Comment: 20 pages, 4 figure

Sex Differences in Primary and Secondary Prevention of Cardiovascular Disease in China

Background: Despite improvements in diagnostic and therapeutic interventions to combat cardiovascular disease (CVD) in recent decades, there are significant ongoing access gaps and sex disparities in prevention that have not been adequately quantified in China. Methods: A representative, cross-sectional, community-based survey of adults (aged ≥45 years) was conducted in 7 geographic regions of China between 2014 and 2016. Logistic regression models were used to determine sex differences in primary and secondary CVD prevention, and any interaction by age, education level, and area of residence. Data are presented as adjusted odds ratios (ORs) and 95% CIs. Results: Of 47 841 participants (61.3% women), 5454 (57.2% women) had established CVD and 9532 (70.5% women) had a high estimated 10-year CVD risk (≥10%). Only 48.5% and 48.6% of women and 39.3% and 59.8% of men were on any kind of blood pressure (BP)-lowering medication, lipid-lowering medication, or antiplatelet therapy for primary and secondary prevention, respectively. Women with established CVD were significantly less likely than men to receive BP-lowering medications (OR, 0.79 [95% CI, 0.65-0.95]), lipid-lowering medications (OR, 0.69 [95% CI, 0.56-0.84]), antiplatelets (OR, 0.53 [95% CI, 0.45-0.62]), or any CVD prevention medication (OR, 0.62 [95% CI, 0.52-0.73]). Women with established CVD, however, had better BP control (OR, 1.31 [95% CI, 1.14-1.50]) but less well-controlled low-density lipoprotein cholesterol (OR, 0.66 [95% CI, 0.57-0.76]), and were less likely to smoke (OR, 13.89 [95% CI, 11.24-17.15]) and achieve physical activity targets (OR, 1.92 [95% CI, 1.61-2.29]). Conversely, women with high CVD risk were less likely than men to have their BP, low-density lipoprotein cholesterol, and bodyweight controlled (OR, 0.46 [95% CI, 0.38-0.55]; OR, 0.60 [95% CI, 0.52-0.69]; OR, 0.55 [95% CI, 0.48-0.63], respectively), despite a higher use of BP-lowering medications (OR, 1.21 [95% CI, 1.01-1.45]). Younger patients (<65 years) with established CVD were less likely to be taking CVD preventive medications, but there were no sex differences by area of residence or education level. Conclusions: Large and variable gaps in primary and secondary CVD prevention exist in China, particularly for women. Effective CVD prevention requires an improved overall nationwide strategy and a special emphasis on women with established CVD, who have the greatest disparity and the most to benefit