nea Obstructive Sleep Apnea, a Risk Factor for Cardiovascular and Microvascular Disease in Patients With Type 2 Diabetes: Findings From a Population-Based Cohort Study By care.diabetesjournals.org Published On :: 2020-04-28T14:33:04-07:00 OBJECTIVETo determine the risk of cardiovascular disease (CVD), microvascular complications, and mortality in patients with type 2 diabetes who subsequently develop obstructive sleep apnea (OSA) compared with patients with type 2 diabetes without a diagnosis of OSA.RESEARCH DESIGN AND METHODSThis age-, sex-, BMI-, and diabetes duration–matched cohort study used data from a U.K. primary care database from 1 January 2005 to 17 January 2018. Participants aged ≥16 years with type 2 diabetes were included. Exposed participants were those who developed OSA after their diabetes diagnosis; unexposed participants were those without diagnosed OSA. Outcomes were composite CVD (ischemic heart disease [IHD], stroke/transient ischemic attack [TIA], heart failure [HF]), peripheral vascular disease (PVD), atrial fibrillation (AF), peripheral neuropathy (PN), diabetes-related foot disease (DFD), referable retinopathy, chronic kidney disease (CKD), and all-cause mortality. The same outcomes were explored in patients with preexisting OSA before a diagnosis of type 2 diabetes versus diabetes without diagnosed OSA.RESULTSA total of 3,667 exposed participants and 10,450 matched control participants were included. Adjusted hazard ratios for the outcomes were as follows: composite CVD 1.54 (95% CI 1.32, 1.79), IHD 1.55 (1.26, 1.90), HF 1.67 (1.35, 2.06), stroke/TIA 1.57 (1.27, 1.94), PVD 1.10 (0.91, 1.32), AF 1.53 (1.28, 1.83), PN 1.32 (1.14, 1.51), DFD 1.42 (1.16, 1.74), referable retinopathy 0.99 (0.82, 1.21), CKD (stage 3–5) 1.18 (1.02, 1.36), albuminuria 1.11 (1.01, 1.22), and all-cause mortality 1.24 (1.10, 1.40). In the prevalent OSA cohort, the results were similar, but some associations were not observed.CONCLUSIONSPatients with type 2 diabetes who develop OSA are at increased risk of CVD, AF, PN, DFD, CKD, and all-cause mortality compared with patients without diagnosed OSA. Patients with type 2 diabetes who develop OSA are a high-risk population, and strategies to detect OSA and prevent cardiovascular and microvascular complications should be implemented. Full Article
nea Continuous Positive Airway Pressure Treatment, Glycemia, and Diabetes Risk in Obstructive Sleep Apnea and Comorbid Cardiovascular Disease By care.diabetesjournals.org Published On :: 2020-05-07T07:52:43-07:00 OBJECTIVEDespite evidence of a relationship among obstructive sleep apnea (OSA), metabolic dysregulation, and diabetes, it is uncertain whether OSA treatment can improve metabolic parameters. We sought to determine effects of long-term continuous positive airway pressure (CPAP) treatment on glycemic control and diabetes risk in patients with cardiovascular disease (CVD) and OSA.RESEARCH DESIGN AND METHODSBlood, medical history, and personal data were collected in a substudy of 888 participants in the Sleep Apnea Cardiovascular End Points (SAVE) trial in which patients with OSA and stable CVD were randomized to receive CPAP plus usual care, or usual care alone. Serum glucose and glycated hemoglobin A1c (HbA1c) were measured at baseline, 6 months, and 2 and 4 years and incident diabetes diagnoses recorded.RESULTSMedian follow-up was 4.3 years. In those with preexisting diabetes (n = 274), there was no significant difference between the CPAP and usual care groups in serum glucose, HbA1c, or antidiabetic medications during follow-up. There were also no significant between-group differences in participants with prediabetes (n = 452) or in new diagnoses of diabetes. Interaction testing suggested that women with diabetes did poorly in the usual care group, while their counterparts on CPAP therapy remained stable.CONCLUSIONSAmong patients with established CVD and OSA, we found no evidence that CPAP therapy over several years affects glycemic control in those with diabetes or prediabetes or diabetes risk over standard-of-care treatment. The potential differential effect according to sex deserves further investigation. Full Article
nea Labor Dept.: U.S. economy lost 20.5M jobs in April, unemployment near 15% By www.upi.com Published On :: Fri, 08 May 2020 08:33:06 -0400 The United States economy shed more than 20 million jobs last month, the greatest month-to-month decline in history, the Labor Department said Friday in its monthly employment analysis. Full Article
nea DNA genealogy leads police to James E. Zastawnik in 1987 killing of Ohio teen Barbara Blatnik By www.upi.com Published On :: Fri, 08 May 2020 12:56:53 -0400 Cleveland police say they have used DNA research to solve the 33-year-old strangling of a teenage girl, and arrest her killer. Full Article
nea Neanderthals preferred bovine bones for leather-making tools By www.upi.com Published On :: Fri, 08 May 2020 16:14:58 -0400 When it came to selecting bones for leather-making tools, Neanderthals were surprisingly choosy. New archaeological analysis shows Neanderthals preferentially selected bovine rib bones to make a tool called a lissoir. Full Article
nea [ Law & Ethics ] Open Question : If a relict population of Neandertals were found to be living in a certain cave, on a certain remote island, or in a certain house on? By answers.yahoo.com Published On :: Sat, 09 May 2020 17:19:55 +0000 Pennsylvania Avenue, would placing some of them in zoos be unethical? Would they be considered human enough to receive human rights? Full Article
nea Beyond Transactional Deals: Building Lasting Migration Partnerships in the Mediterranean By www.migrationpolicy.org Published On :: Mon, 13 Nov 2017 15:59:04 -0500 Since the 2015–16 refugee crisis, European policymakers have eagerly sought cooperation with origin and transit countries in the hopes of stemming unauthorized migration to Europe. This approach is neither new, nor without its limitations. By examining the evolution of two longstanding Mediterranean partnerships—between Spain and Morocco, and Italy and Tunisia—this report offers insights on what has and has not worked. Full Article
nea Sticky pineapple and macadamia upside-down cake By www.abc.net.au Published On :: Mon, 16 Nov 2015 12:47:00 +1100 This is what I think of as an honest cake - not tizzy, just homely, buttery and ever-so more-ish with its tender, nutty crumb and sweet, caramelised pineapple topping. I particularly love the way the sides, through some kind of magical alchemy of heat and sugar, become ever-so-slightly crunchy. There are a couple of little things I've noticed when I bake it - the first is that it cooks better and looks better when baked in a regular, not a non-stick, cake tin. And the second is that it's really important not to overload the tin with pineapple or it will release too much liquid and the centre of the cake will be soggy. Full Article ABC Local northcoast Lifestyle and Leisure:Food and Cooking:All Lifestyle and Leisure:Recipes:All Lifestyle and Leisure:Recipes:Main Australia:NSW:Lismore 2480
nea Mini Sneakers Chocolates By www.abc.net.au Published On :: Tue, 14 Feb 2017 10:04:00 +1100 Pana Barbounis, author of 'Pana Chocolate, The Recipes', shared this recipe on Foodie Tuesday, a weekly segment on ABC Radio Melbourne's Drive program at 3.30pm. Full Article ABC Local melbourne Lifestyle and Leisure:Recipes:All Australia:VIC:Melbourne 3000
nea Civics Tests as a Graduation Requirement: Coming Soon to a State Near You? By feedproxy.google.com Published On :: Mon, 17 Aug 2015 00:00:00 +0000 Eight states have passed laws requiring students to pass some version of a civics test so far in 2015. Full Article North_Dakota
nea After Nearly Three Decades in Office, N.D. Schools Chief to Step Down By feedproxy.google.com Published On :: Fri, 17 Feb 2012 00:00:00 +0000 Wayne Sanstead, who has been North Dakota's state schools superintendent for nearly three decades, has decided not to run for an eighth term this fall. Full Article North_Dakota
nea Colorado Voters to Decide Nearly 40 Ballot Questions to Support Education By feedproxy.google.com Published On :: Tue, 23 Oct 2018 00:00:00 +0000 Dozens of Colorado school districts are asking voters next month for more funding for education through bond issues, mill levy overrides, or renewal of a city sales tax. Full Article Colorado
nea Incoming California Governor to Seek Nearly $2 Billion in Early-Childhood Funding By feedproxy.google.com Published On :: Fri, 04 Jan 2019 00:00:00 +0000 Democrat Gavin Newsom, who takes office Jan. 7, plans to expand full-day kindergarten and child-care offerings in the state, according to media reports. Full Article California
nea Trust Local School Leaders, a State Chief Says as Optional Reopening Date Nears By feedproxy.google.com Published On :: Tue, 05 May 2020 00:00:00 +0000 Montana Superintendent Elsie Arntzen offers practical advice to schools that could open as early as May 7, even as she says "how they open schools and how learning takes place is up to them." Full Article Montana
nea Child-Care Challenges Cost Georgia Nearly $2 Billion Annually, Study Finds By feedproxy.google.com Published On :: Fri, 09 Nov 2018 00:00:00 +0000 A new study says that problems surrounding child-care hurt Georgia parents economically in many ways including in turned down promotions and having to cut back on work and school hours. Full Article Georgia
nea Pirates of romance / Asta Idonea.. By www.catalog.slsa.sa.gov.au Published On :: "Xander joins his local am-dram group in order to make friends. He certainly doesn't expect to fall for the group's playboy star. Graeme is confident and easygoing. He believes in fun without commitment. However, all that changes when Xander gets under his skin" -- Pub;isher info. Full Article
nea Guinea Pig in White Wine Sauce. By www.catalog.slsa.sa.gov.au Published On :: Alan Rochford was living the dream when he started Stone Cottage, an idyllic French restaurant nestled in the Adelaide Hills. He had everything going for him apart from experience, money, and the first idea about what he was doing. After two years and one divorce, he began to see the funny side, fed on an endless diet of characters and occurrences so crazy that you couldn't make them up. Australia's answer to Basil Fawlty, Alan serves up a degustation of lip-smacking anecdotes, from his side-line in snail trading across the French countryside, to the time two customers got a touch too 'intimate' in the middle of his dining room. Guinea Pig in White Wine Sauce is the tale of one man trying to keep his head in the certifiably insane world of fine dining. Full Article
nea The DASH diet Mediterranean solution : the best eating plan to control your weight and improve your health for life / Marla Heller, MS, RD. By www.catalog.slsa.sa.gov.au Published On :: Hypertension -- Diet therapy -- Recipes. Full Article
nea Scottish genealogy / Bruce Durie. By www.catalog.slsa.sa.gov.au Published On :: Scotland -- Genealogy. Full Article
nea The Family Tree Polish, Czech & Slovak genealogy guide : how to trace your family tree in Eastern Europe / Lisa A. Alzo. By www.catalog.slsa.sa.gov.au Published On :: Polish people -- Genealogy. Full Article
nea Genealogy / by Matthew L. Helm and April Leigh Helm. By www.catalog.slsa.sa.gov.au Published On :: Genealogy -- Handbooks, manuals, etc. Full Article
nea Understanding documents for genealogy & local history / Bruce Durie. By www.catalog.slsa.sa.gov.au Published On :: Archival materials -- Handbooks, manuals, etc. Full Article
nea War for Peace : genealogies of a violent ideal in Western and Islamic thought / Murad Idris. By www.catalog.slsa.sa.gov.au Published On :: Peace (Philosophy) Full Article
nea Des methodes generales d'operation de la cataracte et en particulier de l'extraction lineaire composee / par Paul Hyades. By feedproxy.google.com Published On :: Paris : J.-B. Baillière, 1870. Full Article
nea Die Drainirung der Peritonealhohle : chirurgische Studien, nebst einem Bericht uber sieben Nierenexstirpationen / von Dr. Bardenheuer. By feedproxy.google.com Published On :: Stuttgart : F. Enke, 1881. Full Article
nea Dissertatio medica, inauguralis, de mutatione febrium e tempore Sydenhami, et curatione earum idonea / Jacobus Hutchinson. By feedproxy.google.com Published On :: Edinburgi : Apud Balfour et Smellie, 1782. Full Article
nea Du passage de quelques médicaments dans les urines : modifications qu'ils y apportent, transformations qu'ils subissent dans l'organisme / par Léopold Bruneau. By feedproxy.google.com Published On :: Paris : V.A. Delahaye, 1880. Full Article
nea The School District Where the Shutdown Hit Nearly Everyone By feedproxy.google.com Published On :: Fri, 25 Jan 2019 00:00:00 +0000 In Kodiak, Alaska, a school district with deep ties to the U.S. Coast Guard has been walloped by the government shutdown with hundreds of families going without paychecks. And news of a deal to temporarily reopen the government was doing little to allay the community's anxieties. Full Article Alaska
nea Aeneas carrying his father Anchises on his shoulders as he, his son Ascanius and his wife Creusa flee from the sack of Troy. Engraving by R. Guidi after Agostino Carracci after F. Barocci. By feedproxy.google.com Published On :: Full Article
nea Estimation of linear projections of non-sparse coefficients in high-dimensional regression By projecteuclid.org Published On :: Mon, 27 Apr 2020 22:02 EDT David Azriel, Armin Schwartzman. Source: Electronic Journal of Statistics, Volume 14, Number 1, 174--206.Abstract: In this work we study estimation of signals when the number of parameters is much larger than the number of observations. A large body of literature assumes for these kind of problems a sparse structure where most of the parameters are zero or close to zero. When this assumption does not hold, one can focus on low-dimensional functions of the parameter vector. In this work we study one-dimensional linear projections. Specifically, in the context of high-dimensional linear regression, the parameter of interest is ${oldsymbol{eta}}$ and we study estimation of $mathbf{a}^{T}{oldsymbol{eta}}$. We show that $mathbf{a}^{T}hat{oldsymbol{eta}}$, where $hat{oldsymbol{eta}}$ is the least squares estimator, using pseudo-inverse when $p>n$, is minimax and admissible. Thus, for linear projections no regularization or shrinkage is needed. This estimator is easy to analyze and confidence intervals can be constructed. We study a high-dimensional dataset from brain imaging where it is shown that the signal is weak, non-sparse and significantly different from zero. Full Article
nea A fast and consistent variable selection method for high-dimensional multivariate linear regression with a large number of explanatory variables By projecteuclid.org Published On :: Fri, 27 Mar 2020 22:00 EDT Ryoya Oda, Hirokazu Yanagihara. Source: Electronic Journal of Statistics, Volume 14, Number 1, 1386--1412.Abstract: We put forward a variable selection method for selecting explanatory variables in a normality-assumed multivariate linear regression. It is cumbersome to calculate variable selection criteria for all subsets of explanatory variables when the number of explanatory variables is large. Therefore, we propose a fast and consistent variable selection method based on a generalized $C_{p}$ criterion. The consistency of the method is provided by a high-dimensional asymptotic framework such that the sample size and the sum of the dimensions of response vectors and explanatory vectors divided by the sample size tend to infinity and some positive constant which are less than one, respectively. Through numerical simulations, it is shown that the proposed method has a high probability of selecting the true subset of explanatory variables and is fast under a moderate sample size even when the number of dimensions is large. Full Article
nea Derivative-Free Methods for Policy Optimization: Guarantees for Linear Quadratic Systems By Published On :: 2020 We study derivative-free methods for policy optimization over the class of linear policies. We focus on characterizing the convergence rate of these methods when applied to linear-quadratic systems, and study various settings of driving noise and reward feedback. Our main theoretical result provides an explicit bound on the sample or evaluation complexity: we show that these methods are guaranteed to converge to within any pre-specified tolerance of the optimal policy with a number of zero-order evaluations that is an explicit polynomial of the error tolerance, dimension, and curvature properties of the problem. Our analysis reveals some interesting differences between the settings of additive driving noise and random initialization, as well as the settings of one-point and two-point reward feedback. Our theory is corroborated by simulations of derivative-free methods in application to these systems. Along the way, we derive convergence rates for stochastic zero-order optimization algorithms when applied to a certain class of non-convex problems. Full Article
nea Learning Linear Non-Gaussian Causal Models in the Presence of Latent Variables By Published On :: 2020 We consider the problem of learning causal models from observational data generated by linear non-Gaussian acyclic causal models with latent variables. Without considering the effect of latent variables, the inferred causal relationships among the observed variables are often wrong. Under faithfulness assumption, we propose a method to check whether there exists a causal path between any two observed variables. From this information, we can obtain the causal order among the observed variables. The next question is whether the causal effects can be uniquely identified as well. We show that causal effects among observed variables cannot be identified uniquely under mere assumptions of faithfulness and non-Gaussianity of exogenous noises. However, we are able to propose an efficient method that identifies the set of all possible causal effects that are compatible with the observational data. We present additional structural conditions on the causal graph under which causal effects among observed variables can be determined uniquely. Furthermore, we provide necessary and sufficient graphical conditions for unique identification of the number of variables in the system. Experiments on synthetic data and real-world data show the effectiveness of our proposed algorithm for learning causal models. Full Article
nea Branch and Bound for Piecewise Linear Neural Network Verification By Published On :: 2020 The success of Deep Learning and its potential use in many safety-critical applicationshas motivated research on formal verification of Neural Network (NN) models. In thiscontext, verification involves proving or disproving that an NN model satisfies certaininput-output properties. Despite the reputation of learned NN models as black boxes,and the theoretical hardness of proving useful properties about them, researchers havebeen successful in verifying some classes of models by exploiting their piecewise linearstructure and taking insights from formal methods such as Satisifiability Modulo Theory.However, these methods are still far from scaling to realistic neural networks. To facilitateprogress on this crucial area, we exploit the Mixed Integer Linear Programming (MIP) formulation of verification to propose a family of algorithms based on Branch-and-Bound (BaB). We show that our family contains previous verification methods as special cases.With the help of the BaB framework, we make three key contributions. Firstly, we identifynew methods that combine the strengths of multiple existing approaches, accomplishingsignificant performance improvements over previous state of the art. Secondly, we introducean effective branching strategy on ReLU non-linearities. This branching strategy allows usto efficiently and successfully deal with high input dimensional problems with convolutionalnetwork architecture, on which previous methods fail frequently. Finally, we proposecomprehensive test data sets and benchmarks which includes a collection of previouslyreleased testcases. We use the data sets to conduct a thorough experimental comparison ofexisting and new algorithms and to provide an inclusive analysis of the factors impactingthe hardness of verification problems. Full Article
nea Stein characterizations for linear combinations of gamma random variables By projecteuclid.org Published On :: Mon, 04 May 2020 04:00 EDT Benjamin Arras, Ehsan Azmoodeh, Guillaume Poly, Yvik Swan. Source: Brazilian Journal of Probability and Statistics, Volume 34, Number 2, 394--413.Abstract: In this paper we propose a new, simple and explicit mechanism allowing to derive Stein operators for random variables whose characteristic function satisfies a simple ODE. We apply this to study random variables which can be represented as linear combinations of (not necessarily independent) gamma distributed random variables. The connection with Malliavin calculus for random variables in the second Wiener chaos is detailed. An application to McKay Type I random variables is also outlined. Full Article
nea Robust Bayesian model selection for heavy-tailed linear regression using finite mixtures By projecteuclid.org Published On :: Mon, 03 Feb 2020 04:00 EST Flávio B. Gonçalves, Marcos O. Prates, Victor Hugo Lachos. Source: Brazilian Journal of Probability and Statistics, Volume 34, Number 1, 51--70.Abstract: In this paper, we present a novel methodology to perform Bayesian model selection in linear models with heavy-tailed distributions. We consider a finite mixture of distributions to model a latent variable where each component of the mixture corresponds to one possible model within the symmetrical class of normal independent distributions. Naturally, the Gaussian model is one of the possibilities. This allows for a simultaneous analysis based on the posterior probability of each model. Inference is performed via Markov chain Monte Carlo—a Gibbs sampler with Metropolis–Hastings steps for a class of parameters. Simulated examples highlight the advantages of this approach compared to a segregated analysis based on arbitrarily chosen model selection criteria. Examples with real data are presented and an extension to censored linear regression is introduced and discussed. Full Article
nea A new log-linear bimodal Birnbaum–Saunders regression model with application to survival data By projecteuclid.org Published On :: Mon, 04 Mar 2019 04:00 EST Francisco Cribari-Neto, Rodney V. Fonseca. Source: Brazilian Journal of Probability and Statistics, Volume 33, Number 2, 329--355.Abstract: The log-linear Birnbaum–Saunders model has been widely used in empirical applications. We introduce an extension of this model based on a recently proposed version of the Birnbaum–Saunders distribution which is more flexible than the standard Birnbaum–Saunders law since its density may assume both unimodal and bimodal shapes. We show how to perform point estimation, interval estimation and hypothesis testing inferences on the parameters that index the regression model we propose. We also present a number of diagnostic tools, such as residual analysis, local influence, generalized leverage, generalized Cook’s distance and model misspecification tests. We investigate the usefulness of model selection criteria and the accuracy of prediction intervals for the proposed model. Results of Monte Carlo simulations are presented. Finally, we also present and discuss an empirical application. Full Article
nea Bayesian robustness to outliers in linear regression and ratio estimation By projecteuclid.org Published On :: Mon, 04 Mar 2019 04:00 EST Alain Desgagné, Philippe Gagnon. Source: Brazilian Journal of Probability and Statistics, Volume 33, Number 2, 205--221.Abstract: Whole robustness is a nice property to have for statistical models. It implies that the impact of outliers gradually vanishes as they approach plus or minus infinity. So far, the Bayesian literature provides results that ensure whole robustness for the location-scale model. In this paper, we make two contributions. First, we generalise the results to attain whole robustness in simple linear regression through the origin, which is a necessary step towards results for general linear regression models. We allow the variance of the error term to depend on the explanatory variable. This flexibility leads to the second contribution: we provide a simple Bayesian approach to robustly estimate finite population means and ratios. The strategy to attain whole robustness is simple since it lies in replacing the traditional normal assumption on the error term by a super heavy-tailed distribution assumption. As a result, users can estimate the parameters as usual, using the posterior distribution. Full Article
nea lmSubsets: Exact Variable-Subset Selection in Linear Regression for R By www.jstatsoft.org Published On :: Tue, 28 Apr 2020 00:00:00 +0000 An R package for computing the all-subsets regression problem is presented. The proposed algorithms are based on computational strategies recently developed. A novel algorithm for the best-subset regression problem selects subset models based on a predetermined criterion. The package user can choose from exact and from approximation algorithms. The core of the package is written in C++ and provides an efficient implementation of all the underlying numerical computations. A case study and benchmark results illustrate the usage and the computational efficiency of the package. Full Article
nea Domestic Gag Rule Reduces Contraceptive Access For Nearly 370,000... By www.prweb.com Published On :: According to data released by Power to Decide, an estimated 369,960 New Jersey women of reproductive age (13-44) in need of publicly funded contraception live in counties impacted by the...(PRWeb April 09, 2020)Read the full story at https://www.prweb.com/releases/domestic_gag_rule_reduces_contraceptive_access_for_nearly_370_000_women_living_in_new_jersey/prweb17040987.htm Full Article
nea Asymptotic genealogies of interacting particle systems with an application to sequential Monte Carlo By projecteuclid.org Published On :: Mon, 17 Feb 2020 04:02 EST Jere Koskela, Paul A. Jenkins, Adam M. Johansen, Dario Spanò. Source: The Annals of Statistics, Volume 48, Number 1, 560--583.Abstract: We study weighted particle systems in which new generations are resampled from current particles with probabilities proportional to their weights. This covers a broad class of sequential Monte Carlo (SMC) methods, widely-used in applied statistics and cognate disciplines. We consider the genealogical tree embedded into such particle systems, and identify conditions, as well as an appropriate time-scaling, under which they converge to the Kingman $n$-coalescent in the infinite system size limit in the sense of finite-dimensional distributions. Thus, the tractable $n$-coalescent can be used to predict the shape and size of SMC genealogies, as we illustrate by characterising the limiting mean and variance of the tree height. SMC genealogies are known to be connected to algorithm performance, so that our results are likely to have applications in the design of new methods as well. Our conditions for convergence are strong, but we show by simulation that they do not appear to be necessary. Full Article
nea Optimal prediction in the linearly transformed spiked model By projecteuclid.org Published On :: Mon, 17 Feb 2020 04:02 EST Edgar Dobriban, William Leeb, Amit Singer. Source: The Annals of Statistics, Volume 48, Number 1, 491--513.Abstract: We consider the linearly transformed spiked model , where the observations $Y_{i}$ are noisy linear transforms of unobserved signals of interest $X_{i}$: egin{equation*}Y_{i}=A_{i}X_{i}+varepsilon_{i},end{equation*} for $i=1,ldots ,n$. The transform matrices $A_{i}$ are also observed. We model the unobserved signals (or regression coefficients) $X_{i}$ as vectors lying on an unknown low-dimensional space. Given only $Y_{i}$ and $A_{i}$ how should we predict or recover their values? The naive approach of performing regression for each observation separately is inaccurate due to the large noise level. Instead, we develop optimal methods for predicting $X_{i}$ by “borrowing strength” across the different samples. Our linear empirical Bayes methods scale to large datasets and rely on weak moment assumptions. We show that this model has wide-ranging applications in signal processing, deconvolution, cryo-electron microscopy, and missing data with noise. For missing data, we show in simulations that our methods are more robust to noise and to unequal sampling than well-known matrix completion methods. Full Article
nea Efficient estimation of linear functionals of principal components By projecteuclid.org Published On :: Mon, 17 Feb 2020 04:02 EST Vladimir Koltchinskii, Matthias Löffler, Richard Nickl. Source: The Annals of Statistics, Volume 48, Number 1, 464--490.Abstract: We study principal component analysis (PCA) for mean zero i.i.d. Gaussian observations $X_{1},dots,X_{n}$ in a separable Hilbert space $mathbb{H}$ with unknown covariance operator $Sigma $. The complexity of the problem is characterized by its effective rank $mathbf{r}(Sigma):=frac{operatorname{tr}(Sigma)}{|Sigma |}$, where $mathrm{tr}(Sigma)$ denotes the trace of $Sigma $ and $|Sigma|$ denotes its operator norm. We develop a method of bias reduction in the problem of estimation of linear functionals of eigenvectors of $Sigma $. Under the assumption that $mathbf{r}(Sigma)=o(n)$, we establish the asymptotic normality and asymptotic properties of the risk of the resulting estimators and prove matching minimax lower bounds, showing their semiparametric optimality. Full Article
nea Hypothesis testing on linear structures of high-dimensional covariance matrix By projecteuclid.org Published On :: Wed, 30 Oct 2019 22:03 EDT Shurong Zheng, Zhao Chen, Hengjian Cui, Runze Li. Source: The Annals of Statistics, Volume 47, Number 6, 3300--3334.Abstract: This paper is concerned with test of significance on high-dimensional covariance structures, and aims to develop a unified framework for testing commonly used linear covariance structures. We first construct a consistent estimator for parameters involved in the linear covariance structure, and then develop two tests for the linear covariance structures based on entropy loss and quadratic loss used for covariance matrix estimation. To study the asymptotic properties of the proposed tests, we study related high-dimensional random matrix theory, and establish several highly useful asymptotic results. With the aid of these asymptotic results, we derive the limiting distributions of these two tests under the null and alternative hypotheses. We further show that the quadratic loss based test is asymptotically unbiased. We conduct Monte Carlo simulation study to examine the finite sample performance of the two tests. Our simulation results show that the limiting null distributions approximate their null distributions quite well, and the corresponding asymptotic critical values keep Type I error rate very well. Our numerical comparison implies that the proposed tests outperform existing ones in terms of controlling Type I error rate and power. Our simulation indicates that the test based on quadratic loss seems to have better power than the test based on entropy loss. Full Article
nea Projected spline estimation of the nonparametric function in high-dimensional partially linear models for massive data By projecteuclid.org Published On :: Fri, 02 Aug 2019 22:04 EDT Heng Lian, Kaifeng Zhao, Shaogao Lv. Source: The Annals of Statistics, Volume 47, Number 5, 2922--2949.Abstract: In this paper, we consider the local asymptotics of the nonparametric function in a partially linear model, within the framework of the divide-and-conquer estimation. Unlike the fixed-dimensional setting in which the parametric part does not affect the nonparametric part, the high-dimensional setting makes the issue more complicated. In particular, when a sparsity-inducing penalty such as lasso is used to make the estimation of the linear part feasible, the bias introduced will propagate to the nonparametric part. We propose a novel approach for estimation of the nonparametric function and establish the local asymptotics of the estimator. The result is useful for massive data with possibly different linear coefficients in each subpopulation but common nonparametric function. Some numerical illustrations are also presented. Full Article
nea Linear hypothesis testing for high dimensional generalized linear models By projecteuclid.org Published On :: Fri, 02 Aug 2019 22:04 EDT Chengchun Shi, Rui Song, Zhao Chen, Runze Li. Source: The Annals of Statistics, Volume 47, Number 5, 2671--2703.Abstract: This paper is concerned with testing linear hypotheses in high dimensional generalized linear models. To deal with linear hypotheses, we first propose the constrained partial regularization method and study its statistical properties. We further introduce an algorithm for solving regularization problems with folded-concave penalty functions and linear constraints. To test linear hypotheses, we propose a partial penalized likelihood ratio test, a partial penalized score test and a partial penalized Wald test. We show that the limiting null distributions of these three test statistics are $chi^{2}$ distribution with the same degrees of freedom, and under local alternatives, they asymptotically follow noncentral $chi^{2}$ distributions with the same degrees of freedom and noncentral parameter, provided the number of parameters involved in the test hypothesis grows to $infty$ at a certain rate. Simulation studies are conducted to examine the finite sample performance of the proposed tests. Empirical analysis of a real data example is used to illustrate the proposed testing procedures. Full Article
nea Modeling wildfire ignition origins in southern California using linear network point processes By projecteuclid.org Published On :: Wed, 15 Apr 2020 22:05 EDT Medha Uppala, Mark S. Handcock. Source: The Annals of Applied Statistics, Volume 14, Number 1, 339--356.Abstract: This paper focuses on spatial and temporal modeling of point processes on linear networks. Point processes on linear networks can simply be defined as point events occurring on or near line segment network structures embedded in a certain space. A separable modeling framework is introduced that posits separate formation and dissolution models of point processes on linear networks over time. While the model was inspired by spider web building activity in brick mortar lines, the focus is on modeling wildfire ignition origins near road networks over a span of 14 years. As most wildfires in California have human-related origins, modeling the origin locations with respect to the road network provides insight into how human, vehicular and structural densities affect ignition occurrence. Model results show that roads that traverse different types of regions such as residential, interface and wildland regions have higher ignition intensities compared to roads that only exist in each of the mentioned region types. Full Article
nea Optimal asset allocation with multivariate Bayesian dynamic linear models By projecteuclid.org Published On :: Wed, 15 Apr 2020 22:05 EDT Jared D. Fisher, Davide Pettenuzzo, Carlos M. Carvalho. Source: The Annals of Applied Statistics, Volume 14, Number 1, 299--338.Abstract: We introduce a fast, closed-form, simulation-free method to model and forecast multiple asset returns and employ it to investigate the optimal ensemble of features to include when jointly predicting monthly stock and bond excess returns. Our approach builds on the Bayesian dynamic linear models of West and Harrison ( Bayesian Forecasting and Dynamic Models (1997) Springer), and it can objectively determine, through a fully automated procedure, both the optimal set of regressors to include in the predictive system and the degree to which the model coefficients, volatilities and covariances should vary over time. When applied to a portfolio of five stock and bond returns, we find that our method leads to large forecast gains, both in statistical and economic terms. In particular, we find that relative to a standard no-predictability benchmark, the optimal combination of predictors, stochastic volatility and time-varying covariances increases the annualized certainty equivalent returns of a leverage-constrained power utility investor by more than 500 basis points. Full Article
nea Joint model of accelerated failure time and mechanistic nonlinear model for censored covariates, with application in HIV/AIDS By projecteuclid.org Published On :: Wed, 27 Nov 2019 22:01 EST Hongbin Zhang, Lang Wu. Source: The Annals of Applied Statistics, Volume 13, Number 4, 2140--2157.Abstract: For a time-to-event outcome with censored time-varying covariates, a joint Cox model with a linear mixed effects model is the standard modeling approach. In some applications such as AIDS studies, mechanistic nonlinear models are available for some covariate process such as viral load during anti-HIV treatments, derived from the underlying data-generation mechanisms and disease progression. Such a mechanistic nonlinear covariate model may provide better-predicted values when the covariates are left censored or mismeasured. When the focus is on the impact of the time-varying covariate process on the survival outcome, an accelerated failure time (AFT) model provides an excellent alternative to the Cox proportional hazard model since an AFT model is formulated to allow the influence of the outcome by the entire covariate process. In this article, we consider a nonlinear mixed effects model for the censored covariates in an AFT model, implemented using a Monte Carlo EM algorithm, under the framework of a joint model for simultaneous inference. We apply the joint model to an HIV/AIDS data to gain insights for assessing the association between viral load and immunological restoration during antiretroviral therapy. Simulation is conducted to compare model performance when the covariate model and the survival model are misspecified. Full Article
nea Statistical inference for partially observed branching processes with application to cell lineage tracking of in vivo hematopoiesis By projecteuclid.org Published On :: Wed, 27 Nov 2019 22:01 EST Jason Xu, Samson Koelle, Peter Guttorp, Chuanfeng Wu, Cynthia Dunbar, Janis L. Abkowitz, Vladimir N. Minin. Source: The Annals of Applied Statistics, Volume 13, Number 4, 2091--2119.Abstract: Single-cell lineage tracking strategies enabled by recent experimental technologies have produced significant insights into cell fate decisions, but lack the quantitative framework necessary for rigorous statistical analysis of mechanistic models describing cell division and differentiation. In this paper, we develop such a framework with corresponding moment-based parameter estimation techniques for continuous-time, multi-type branching processes. Such processes provide a probabilistic model of how cells divide and differentiate, and we apply our method to study hematopoiesis , the mechanism of blood cell production. We derive closed-form expressions for higher moments in a general class of such models. These analytical results allow us to efficiently estimate parameters of much richer statistical models of hematopoiesis than those used in previous statistical studies. To our knowledge, the method provides the first rate inference procedure for fitting such models to time series data generated from cellular barcoding experiments. After validating the methodology in simulation studies, we apply our estimator to hematopoietic lineage tracking data from rhesus macaques. Our analysis provides a more complete understanding of cell fate decisions during hematopoiesis in nonhuman primates, which may be more relevant to human biology and clinical strategies than previous findings from murine studies. For example, in addition to previously estimated hematopoietic stem cell self-renewal rate, we are able to estimate fate decision probabilities and to compare structurally distinct models of hematopoiesis using cross validation. These estimates of fate decision probabilities and our model selection results should help biologists compare competing hypotheses about how progenitor cells differentiate. The methodology is transferrable to a large class of stochastic compartmental and multi-type branching models, commonly used in studies of cancer progression, epidemiology and many other fields. Full Article