55 research outputs found

    The Causal Learning of Retail Delinquency

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    This paper focuses on the expected difference in borrower's repayment when there is a change in the lender's credit decisions. Classical estimators overlook the confounding effects and hence the estimation error can be magnificent. As such, we propose another approach to construct the estimators such that the error can be greatly reduced. The proposed estimators are shown to be unbiased, consistent, and robust through a combination of theoretical analysis and numerical testing. Moreover, we compare the power of estimating the causal quantities between the classical estimators and the proposed estimators. The comparison is tested across a wide range of models, including linear regression models, tree-based models, and neural network-based models, under different simulated datasets that exhibit different levels of causality, different degrees of nonlinearity, and different distributional properties. Most importantly, we apply our approaches to a large observational dataset provided by a global technology firm that operates in both the e-commerce and the lending business. We find that the relative reduction of estimation error is strikingly substantial if the causal effects are accounted for correctly.Comment: This paper was accepted and will be published in the Thirty-Fifth AAAI Conference on Artificial Intelligence (AAAI-21

    Clinicopathological significance of non-small cell lung cancer with high prevalence of Oct-4 tumor cells

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    <p>Abstract</p> <p>Background</p> <p>Expression of the stem cell marker octamer 4 (Oct-4) in various neoplasms has been previously reported, but very little is currently known about the potential function of Oct-4 in this setting. The purpose of this study was to assess the prognostic value of Oct-4 expression after surgery in primary non-small cell lung cancer (NSCLC) and investigate its possible molecular mechanism.</p> <p>Methods</p> <p>We measured Oct-4 expression in 113 NSCLC tissue samples and three cell lines by immunohistochemical staining and RT-PCR. The association of Oct-4 expression with demographic characteristics, proliferative marker Ki67, microvessel density (MVD), and expression of vascular endothelial growth factor (VEGF) were assessed.</p> <p>Results</p> <p>Oct-4 expression was detected in 90.3% of samples and was positively correlated with poor differentiation and adenocarcinoma histology, and Oct-4 mRNA was found in each cell lines detected. Overexpression of Oct-4 had a strong association with cells proliferation in all cases, MVD-negative, and VEGF-negative subsets. A Kaplan-Meier analysis showed that overexpression of Oct-4 was associated with shorter overall survival in all cases, adenocarcinoma, squamous cell carcinoma, MVD-negative, and VEGF-negative subsets. A multivariate analysis demonstrated that Oct-4 level in tumor tissue was an independent prognostic factor for overall survival in all cases, MVD-negative, and VEGF-negative subsets.</p> <p>Conclusion</p> <p>Our findings suggest that, even in the context of vulnerable MVD status and VEGF expression, overexpression of Oct-4 in tumor tissue represents a prognostic factor in primary NSCLC patients. Oct-4 may maintain NSCLC cells in a poorly differentiated state through a mechanism that depends on promoting cell proliferation.</p

    Molecular characteristics of rice chimeras containing gene mutations induced by carbon ion beam radiation

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    Chimeras are universal phenomena in the M1-generation plants obtained following radiation-induced mutagenesis; however, the mutational effects and variant inheritance mechanisms of related rice chimeras have yet to be sufficiently clarified. In this study, we used target capture-seq technology to obtain OsNramp5 mutant chimeras via carbon ion beam irradiation, and used a 10 kb liquid chip to determine the SNP/InDel mutational occurrence and genetic isolation characteristics of the chimeric M1 generation and mutational M2 genomes. The results revealed that the mutation detected in the OsNramp5 gene of M1 chimeric rice was not inherited by the M2 generation; that is, the mutation detected in somatic cells of the M1 population was not passed to the subsequent generation via the germ cells. In addition, conversion was established to be twice as common as transversion among the M1 genomic mutation types, although more than half of the variant sites were inherited by the M2 generation. However, these sites were rarely located within the functional coding regions of genes. Our findings in this study revealed the genomic variation characteristics of somatic M1-generation chimeras induced by carbon ion beam irradiation and their genetic characteristics in the M2 generation. These findings will provide a reference for further studies that seek to elucidate the mechanisms underlying chimeric mutation effects and for selecting appropriate procedures for mutagenesis breeding following carbon ion beam irradiation

    Association between inflammatory bowel disease and pancreatic cancer: results from the two-sample Mendelian randomization study

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    BackgroundThe nuanced relationship between inflammatory bowel disease (IBD) and pancreatic cancer is noticed in recent years. However, the underlying causal effects of these two diseases are still unclear.MethodsThe two-sample mendelian randomization (MR) was conducted to explore the causal effect of IBD condition on pancreatic cancer. Methods of Wald ratio, inverse variance weighted (IVW), MR-Egger, weighted median, and weighted mode were used to investigate the causal relationship between IBD and pancreatic cancer. Besides, Cochrane’s Q test, MR-Egger, and leave-one-out method were further conducted to detect heterogeneity, stability, and pleiotropy of MR results.ResultsIn the MR analysis, we found Crohn’s disease had a significant causal effect on pancreatic cancer. Specifically, Crohn’s disease would increase 11.1% the risk of pancreatic cancer by the IVW method (p= 0.022), 33.8% by MR Egger (p= 0.015), by 35.3% by the Weighted model (p= 0.005). Regarding ulcerative colitis, there was no statistically significant causal effect observed on pancreatic cancer (p&gt;0.05). Additionally, the pleiotropic test and Leave-one-out analysis both proved the validity and reliability of the present two-sample MR analyses.ConclusionThis study indicates that IBD, particularly Crohn’s disease, is causality associated with increased risk of pancreatic cancer. Our results may help public health managers to make better follow-up surveillance of IBD patients

    Development and internal validation of a nine-lncRNA prognostic signature for prediction of overall survival in colorectal cancer patients

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    Background Colorectal cancer remains a serious public health problem due to the poor prognosis. In the present study, we attempted to develop and validate a prognostic signature to predict the individual mortality risk in colorectal cancer patients. Materials and Methods The original study datasets were downloaded from The Cancer Genome Atlas database. The present study finally included 424 colorectal cancer patients with wholly gene expression information and overall survival information. Results A nine-lncRNA prognostic signature was built through univariate and multivariate Cox proportional regression model. Time-dependent receiver operating characteristic curves in model cohort demonstrated that the Harrell’s concordance indexes of nine-lncRNA prognostic signature were 0.768 (95% CI [0.717–0.819]), 0.778 (95% CI [0.727–0.829]) and 0.870 (95% CI [0.819–0.921]) for 1-year, 3-year and 5-year overall survival respectively. In validation cohort, the Harrell’s concordance indexes of nine-lncRNA prognostic signature were 0.761 (95% CI [0.710–0.812]), 0.801 (95% CI [0.750–0.852]) and 0.883 (95% CI [0.832–0.934]) for 1-year, 3-year and 5-year overall survival respectively. According to the median of nine-lncRNA prognostic signature score in model cohort, 424 CRC patients could be stratified into high risk group (n = 212) and low risk group (n = 212). Kaplan–Meier survival curves showed that the overall survival rate of high risk group was significantly lower than that of low risk group (P < 0.001). Discussion The present study developed and validated a nine-lncRNA prognostic signature for individual mortality risk assessment in colorectal cancer patients. This nine-lncRNA prognostic signature is helpful to evaluate the individual mortality risk and to improve the decision making of individualized treatments in colorectal cancer patients

    Assessing the role of lipid-lowering therapy on multi-cancer prevention: A mendelian randomization study

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    Background: Statin use for cancer prevention has raised wide attention but the conclusions are still controversial. Whether statins use have exact causal effects on cancer prevention remains unclear.Methods: Based on the Genome-Wide Association Studies (GWAS) datasets from the large prospective UK Biobank and other consortium databases, two-sample mendelian randomization (MR) analysis was conducted to explore the causal effects of statins use on varied site-specific cancer risks. Five MR methods were applied to investigate the causality. The stability, heterogeneity, and pleiotropy of MR results were also evaluated.Results: The atorvastatin use could increase the risk of colorectal cancer (odd ratio (OR) = 1.041, p = 0.035 by fixed-effects inverse variance weighted (IVW) method (IVWFE), OR = 1.086, p = 0.005 by weighted median; OR = 1.101, p = 0.048 by weighted mode, respectively). According to the weighted median and weighted mode, atorvastatin could modestly decrease the risk of liver cell cancer (OR = 0.989, p = 0.049, and OR = 0.984, p = 0.004, respectively) and head and neck cancer (OR = 0.972, p = 0.020). Besides, rosuvastatin use could reduce the bile duct cancer risk by 5.2% via IVWEF method (OR = 0.948, p = 0.031). No significant causality was determined in simvastatin use and pan-cancers via the IVWFE or multiplicative random-effects IVW (IVWMRE) method if applicable (p &gt; 0.05). There was no horizontal pleiotropy observed in the MR analysis and the leave-one-out analysis proved the stability of the results.Conclusion: The causalities between statin use and cancer risk were only observed in colorectal cancer and bile duct cancer in the European ancestry population. Future works are warranted to provide more robust evidence for supporting statin repurposing for cancer prevention

    Strain-dielectric response of dielectrics as foundation for electrostriction stresses

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