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Yiwang Zhou,1 Madeline R Horan,2 Samira Deshpande,1 Kirsten K Ness,2 Melissa M Hudson,3 I-Chan Huang,2,* Deokumar Srivastava1,* 1Department of Biostatistics, St. Jude Children’s Research Hospital, Memphis, TN, USA; 2Department of Epidemiology and Cancer Control, St. Jude Children’s Research Hospital, Memphis, TN, USA; 3Department of Oncology, St. Jude Children’s Research Hospital, Memphis, TN, USA*These authors contributed equally to this workCorrespondence: Yiwang Zhou, Department of Biostatistics, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Mail Stop 768, Memphis, Tennessee, TN 38105, USA, Tel +1 901-595-6736, Email yiwang.zhou@stjude.orgPurpose: Childhood cancer survivors experience interconnected symptoms, patterns of which can be elucidated by network analysis. However, current symptom networks are constructed based on the average survivors without considering individual heterogeneities. We propose to evaluate personal symptom network estimation using the Ising model with covariates through simulations and estimate personal symptom network for adult childhood cancer survivors.Patients and Methods: We adopted the Ising model with covariates to construct networks by employing logistic regressions for estimating associations between binary symptoms. Simulation experiments assessed the robustness of this method in constructing personal symptom network. Real-world data illustration included 1708 adult childhood cancer survivors from the St. Jude Lifetime Cohort Study (SJLIFE), a retrospective cohort study with prospective follow-up to characterize the etiology and late effects for childhood cancer survivors. Patients’ baseline symptoms in 10 domains (cardiac, pulmonary, sensation, nausea, movement, pain, memory, fatigue, anxiety, depression) and individual characteristics (age, sex, race/ethnicity, attained education, personal income, and marital status) were self-reported using survey. Treatment variables (any chemo or radiation therapy) were obtained from medical records. Personal symptom network of 10 domains was estimated using the Ising model, incorporating individual characteristics and treatment data.Results: Simulations confirmed the robustness of the Ising model with covariates in constructing personal symptom networks. Real-world data analysis identified age, sex, race/ethnicity, education, marital status, and treatment (any chemo and radiation therapy) as major factors influencing symptom co-occurrence. Older childhood cancer survivors showed stronger cardiac-fatigue associations. Survivors of racial/ethnic minorities had stronger pain-fatigue associations. Female survivors with above-college education demonstrated stronger pain-anxiety associations. Unmarried survivors who received radiation had stronger association between movement and memory problems.Conclusion: The Ising model with covariates accurately estimates personal symptom networks. Individual heterogeneities exist in symptom co-occurrence patterns for childhood cancer survivors. The estimated personal symptom network offers insights into interconnected symptom experiences.Keywords: bootstrap testing, individual heterogeneity, Ising model, network analysis, sociodemographic

Functional data analysis is ubiquitous in most areas of sciences and engineering. Several paradigms are proposed to deal with the dimensionality problem which is inherent to this type of data. Sparseness, penalization, thresholding, among other principles, have been used to tackle this issue. We discuss here a solution based on a finite-dimensional functional subspace. We employ wavelet representation of random functions to estimate this finite dimension and successfully model a time series of curves. The proposed method is shown to have nice asymptotic properties. Moreover, the wavelet representation permits the use of several bootstrap procedures, and it results in faster computing algorithms. Besides the theoretical and computational properties, some simulation studies and an application to real data are provided. [ABSTRACT FROM AUTHOR]

The test statistic proposed in this paper is an explicit Cramér–von Mises transformation of a certain weighted partial copula function. The regions of rejection are computed using a bootstrap procedure which mimics conditional independence by generating samples from the product measure of the estimated conditional marginals. Under certain (high-level) conditions (on the estimated conditional marginals), rates of convergence for the weighted partial copula process and the test statistic as well as the weak convergence under the null of the normalized test statistic are established. These high-level conditions on the estimated margins are shown to be valid in a variety of examples ranging from nonparametric kernel to linear quantile regression estimates. Finally, an experimental section demonstrates that the proposed test has competitive power compared to recent state-of-the-art methods such as kernel-based test. [ABSTRACT FROM AUTHOR]

Using a new dataset of environmental, social, and corporate governance company ratings for the European market, this article examines whether socially responsible stock selection adds or destroys value in terms of portfolio performance. From 2004 to 2012, we find the following: (i) Negative screens excluding unrated stocks from a representative European stock universe allow investors to significantly outperform a passive investment in a diversified European stock benchmark portfolio. (ii) Additional negative screens based on environmental and social scores neither add nor destroy portfolio value, when cut-off rates are not too high. In contrast, governance screens can significantly increase portfolio performance under similar conditions. Thus, investors in the European stock market can do (financially) well while doing (socially) good. (iii) Because of a loss of diversification, positive screens can cause portfolios to underperform the benchmark. This implies that investors should concentrate on eliminating the worst firms. (iv) Our results are robust along several dimensions, namely, choice of performance measure, time, test parametrisation, portfolio weighting scheme, approximation of the risk-free rate, and consideration of transaction costs. [ABSTRACT FROM AUTHOR]

In this article, we analyse the relation of a new measure for evaluating the importance of soccer players, recently proposed by Hiller (2015), to classic metrics of player performance. Using state-of-the-art bootstrap correlation testing and a data set of teams for the German soccer league (Bundesliga), we find evidence that even though this new game-theoretical approach has no significant correlation to a large number of performance measures, it is significantly related to some of the most important measures typically used in academic research (e.g. the player scores published by sports magazines and the number of played matches). These results indicate that the theoretically appealing new measure can be considered an interesting variable in pay–performance regressions and should be used accordingly in future research. [ABSTRACT FROM AUTHOR]

Abstract: It is said that even the longest journey begins with the first step. This is also true for application software. When the power is switched on, computer systems execute an initial set of operations that usually perform memory tests and load the final runtime environment. This paper describes the Single Event Effects (SEEs) requirements verification of the boot software that will run in the Instrument Control Unit (ICU) of the Energetic Particle Detector (EPD) on-board Solar Orbiter. Since in the booting stage there are no software services at all, it is difficult to achieve a complete software verification on real hardware. To shortcut this issue the Space Research Group (SRG) of the University of Alcalá has developed a LEON2 Virtual Platform (Leon2ViP) based on SystemC with fault injection capabilities. This way it is possible to run the exact same target binary software as if were run on the physical system, but in a controlled and deterministic environment, thus allowing a stricter requirements verification. The use of Leon2ViP has meant a significant improvement, in both time and cost, in the development and verification processes of the ICU's boot software. [Copyright &y& Elsevier]

We increasingly calculate P-values using randomization approaches., Often, it is not possible to consider full evaluation of all possible samples (e.g. permutations or bootstraps) in order to get an exact P-value, so an approximate P-value is calculated across a random sample of these possible samples., We provide methods that allow the uncertainty introduced by this approximation to be compactly and clearly presented., If the recommendations proposed here are adopted, then reviewers and readers of the increasing number of publications using these approaches will be better informed. [ABSTRACT FROM AUTHOR]

Measures of distributional symmetry based on quantiles, L-moments, and trimmed L-moments are briefly reviewed, and (asymptotic) sampling properties of commonly used estimators considered. Standard errors are estimated using both analytical and computer-intensive methods. Simulation is used to assess results when sampling from some known distributions; bootstrapping is used on sample data to estimate standard errors, construct confidence intervals, and test a hypothesis of distributional symmetry. Symmetry measures based on 2- or 3-trimmed L-moments have some advantages over other measures in terms of their existence. Their estimators are generally well behaved, even in relatively small samples. [ABSTRACT FROM AUTHOR]

The problem of identifying the number of modal groups manifested in a sample of data is of continuing interest and importance in statistical practice. In this paper, we combine features of two current approaches to the mode‐testing problem with some new ideas, to produce a method that provides the data analyst with a powerful and flexible way of exploring modality in univariate data. This approach also provides what appears to be the first satisfactory test of modality for samples of circular data. [ABSTRACT FROM PUBLISHER]