Missing Features Reconstruction Using a Wasserstein Generative Adversarial Imputation Network

Missing data is one of the most common preprocessing problems. In this paper, we experimentally research the use of generative and non-generative models for feature reconstruction. Variational Autoencoder with Arbitrary Conditioning (VAEAC) and Generative Adversarial Imputation Network (GAIN) were researched as representatives of generative models, while the denoising autoencoder (DAE) represented non-generative models. Performance of the models is compared to traditional methods k-nearest neighbors (k-NN) and Multiple Imputation by Chained Equations (MICE). Moreover, we introduce WGAIN as the Wasserstein modification of GAIN, which turns out to be the best imputation model when the degree of missingness is less than or equal to 30%. Experiments were performed on real-world and artificial datasets with continuous features where different percentages of features, varying from 10% to 50%, were missing. Evaluation of algorithms was done by measuring the accuracy of the classification model previously trained on the uncorrupted dataset. The results show that GAIN and especially WGAIN are the best imputers regardless of the conditions. In general, they outperform or are comparative to MICE, k-NN, DAE, and VAEAC.Comment: Preprint of the conference paper (ICCS 2020), part of the Lecture Notes in Computer Scienc

Multiple Imputation Ensembles (MIE) for dealing with missing data

Missing data is a significant issue in many real-world datasets, yet there are no robust methods for dealing with it appropriately. In this paper, we propose a robust approach to dealing with missing data in classification problems: Multiple Imputation Ensembles (MIE). Our method integrates two approaches: multiple imputation and ensemble methods and compares two types of ensembles: bagging and stacking. We also propose a robust experimental set-up using 20 benchmark datasets from the UCI machine learning repository. For each dataset, we introduce increasing amounts of data Missing Completely at Random. Firstly, we use a number of single/multiple imputation methods to recover the missing values and then ensemble a number of different classifiers built on the imputed data. We assess the quality of the imputation by using dissimilarity measures. We also evaluate the MIE performance by comparing classification accuracy on the complete and imputed data. Furthermore, we use the accuracy of simple imputation as a benchmark for comparison. We find that our proposed approach combining multiple imputation with ensemble techniques outperform others, particularly as missing data increases

Results of a randomized, double blind, placebo controlled, crossover trial of melatonin for treatment of Nocturia in adults with multiple sclerosis (MeNiMS)

© 2018 The Author(s). Background: Nocturia is a common urinary symptom of multiple sclerosis (MS) which can affect quality of life (QoL) adversely. Melatonin is a hormone known to regulate circadian rhythm and reduce smooth muscle activity such as in the bladder. There is limited evidence supporting use of melatonin to alleviate urinary frequency at night in the treatment of nocturia. The aim of this study was to evaluate the effect of melatonin on the mean number of nocturia episodes per night in patients with MS. Methods: A randomized, double blind, placebo controlled crossover trial was conducted. 34 patients with nocturia secondary to multiple sclerosis underwent a 4-day pre-treatment monitoring phase. The patients were randomized to receive either 2 mg per night (taken at bedtime) of capsulated sustained-release melatonin (Circadin®) or 1 placebo capsule for 6 weeks followed by a crossover to the other regimen for an additional 6 weeks after a 1-month washout period. Results: From the 26 patients who completed the study, there was no significant difference observed in the signs or symptoms of nocturia when taking 2 mg melatonin compared to placebo. The primary outcome measure, mean number of nocturia episodes on bladder diaries, was 1.8/night at baseline, and 1.4/night on melatonin, compared with 1.6 for placebo (Medians 1.70, 1.50, and 1.30 respectively, p = 0.85). There was also no significant difference seen in LUTS, QoL and sleep quality when taking melatonin. No significant safety concerns arose. Conclusions: This small study suggests that a low dose of melatonin taken at bedtime may be ineffective therapy for nocturia in MS. Trial registration: (EudraCT reference) 2012-00418321 registered: 25/01/13. ISRCTN Registry: ISRCTN38687869

Smoking, Alcohol, Diabetes, Obesity, Socioeconomic Status, and the Risk of Colorectal Cancer in a Population-Based Case–Control Study

Purpose: Although previous research has identified factors that may determine willingness to participate in research, relatively few studies have attempted to quantify the impact non-participation may have on exposure–disease associations. The aims of this study were to (a) investigate the associations between smoking, alcohol, diabetes, obesity, and socioeconomic status and the risk of colorectal cancer in a case–control study (59.7 and 47.2 % response fractions among cases and controls, respectively); and (b) perform sensitivity analyses to examine the possible influence of non-participation. Methods: Logistic regression was used to estimate the exposure–disease associations. We then investigated the associations between various demographic and health factors and the likelihood that an individual would participate in the case–control study and then performed two sensitivity analyses (sampling weights and multiple imputation) to examine whether non-participation bias may have influenced the exposure–disease associations. Results: The exposures alcohol, smoking, and diabetes were associated with an increased risk of colorectal cancer. We found some differences between cases and controls when examining the factors associated with the participation in the study, and in the sensitivity analyses, the exposure–disease associations were slightly attenuated when compared with those from the original analysis. Conclusion: Non-participation may have biased the risk estimates away from the null, but generally not enough to change the conclusions of the study

Physical activity for antenatal and postnatal depression in women attempting to quit smoking: randomised controlled trial

Background: Antenatal depression is associated with harmful consequences for both the mother and child. One intervention that might be effective is participation in regular physical activity although data on this question in pregnant smokers is currently lacking. Methods: Women were randomised to six-weekly sessions of smoking cessation behavioural-support, or to the same support plus 14 sessions combining treadmill exercise and physical activity consultations. Results: Among 784 participants (mean gestation 16-weeks), EPDS was significantly higher in the physical activity group versus usual care at end-of-pregnancy (mean group difference (95% confidence intervals (CIs)): 0.95 (0.08 to 1.83). There was no significant difference at six-months postpartum. Conclusion: A pragmatic intervention to increase physical activity in pregnant smokers did not prevent depression at end-of-pregnancy or at six-months postpartum. More effective physical activity interventions are needed in this population. Trial registration: Current Controlled Trials ISRCTN48600346. The trial was prospectively registered on 21/07/2008

Voice, Representation and Trust in Parliament

The procedural justice literature argues that providing individuals voice in institutional processes facilitates trust in that institution. For democratic institutions, voice is provided to the citizenry via political representation. In this article, I apply the procedural justice argument to trust in parliament, equating representation with voice: if individuals believe they are represented in parliament, they will trust parliament more than if they believe otherwise. Analyses of data from three of four countries find support for this argument: those individuals who believe that a party with at least one seat in parliament represents their views trust parliament more than those who do not. This relationship holds even when accounting for political self-interest. For those who wish to promote trust in parliament, a suggested normative good with a host of politically important consequences, one potential pathway is to facilitate individuals’ belief that there is a party in parliament that represents them