lust Night Sounds, a mini chapbook about listening to nature in the city, with black line drawings. Tiny illustrated zine about nature. By search.wellcomelibrary.org Published On :: 2017 Full Article
lust Big brother to an angel / written by Holly Hunt ; illustrated by Jenny Duda. By search.wellcomelibrary.org Published On :: Howe Island, Canada : Pier 44 Press, [2017] Full Article
lust Silly Limbig : a tail of bravery / by Naomi Harvey ; illustrations by Daria Danilova. By search.wellcomelibrary.org Published On :: Great Britain : CreateSpace, 2017. Full Article
lust How babies and families are made : (there is more than one way) / by Patricia Schaffer ; illustrated by Suzanne Corbett. By search.wellcomelibrary.org Published On :: Berkeley, California : Tabor Sarah Books, 1988. Full Article
lust Sydney in 1848 : illustrated by copper-plate engravings of its principal streets, public buildings, churches, chapels, etc. / from drawings by Joseph Fowles. By feedproxy.google.com Published On :: 28/04/2016 12:00:00 AM Full Article
lust Model-based clustering with envelopes By projecteuclid.org Published On :: Thu, 23 Apr 2020 22:01 EDT Wenjing Wang, Xin Zhang, Qing Mai. Source: Electronic Journal of Statistics, Volume 14, Number 1, 82--109.Abstract: Clustering analysis is an important unsupervised learning technique in multivariate statistics and machine learning. In this paper, we propose a set of new mixture models called CLEMM (in short for Clustering with Envelope Mixture Models) that is based on the widely used Gaussian mixture model assumptions and the nascent research area of envelope methodology. Formulated mostly for regression models, envelope methodology aims for simultaneous dimension reduction and efficient parameter estimation, and includes a very recent formulation of envelope discriminant subspace for classification and discriminant analysis. Motivated by the envelope discriminant subspace pursuit in classification, we consider parsimonious probabilistic mixture models where the cluster analysis can be improved by projecting the data onto a latent lower-dimensional subspace. The proposed CLEMM framework and the associated envelope-EM algorithms thus provide foundations for envelope methods in unsupervised and semi-supervised learning problems. Numerical studies on simulated data and two benchmark data sets show significant improvement of our propose methods over the classical methods such as Gaussian mixture models, K-means and hierarchical clustering algorithms. An R package is available at https://github.com/kusakehan/CLEMM. Full Article
lust A Bayesian approach to disease clustering using restricted Chinese restaurant processes By projecteuclid.org Published On :: Wed, 08 Apr 2020 22:01 EDT Claudia Wehrhahn, Samuel Leonard, Abel Rodriguez, Tatiana Xifara. Source: Electronic Journal of Statistics, Volume 14, Number 1, 1449--1478.Abstract: Identifying disease clusters (areas with an unusually high incidence of a particular disease) is a common problem in epidemiology and public health. We describe a Bayesian nonparametric mixture model for disease clustering that constrains clusters to be made of adjacent areal units. This is achieved by modifying the exchangeable partition probability function associated with the Ewen’s sampling distribution. We call the resulting prior the Restricted Chinese Restaurant Process, as the associated full conditional distributions resemble those associated with the standard Chinese Restaurant Process. The model is illustrated using synthetic data sets and in an application to oral cancer mortality in Germany. Full Article
lust $k$-means clustering of extremes By projecteuclid.org Published On :: Mon, 02 Mar 2020 22:02 EST Anja Janßen, Phyllis Wan. Source: Electronic Journal of Statistics, Volume 14, Number 1, 1211--1233.Abstract: The $k$-means clustering algorithm and its variant, the spherical $k$-means clustering, are among the most important and popular methods in unsupervised learning and pattern detection. In this paper, we explore how the spherical $k$-means algorithm can be applied in the analysis of only the extremal observations from a data set. By making use of multivariate extreme value analysis we show how it can be adopted to find “prototypes” of extremal dependence and derive a consistency result for our suggested estimator. In the special case of max-linear models we show furthermore that our procedure provides an alternative way of statistical inference for this class of models. Finally, we provide data examples which show that our method is able to find relevant patterns in extremal observations and allows us to classify extremal events. Full Article
lust Modal clustering asymptotics with applications to bandwidth selection By projecteuclid.org Published On :: Fri, 07 Feb 2020 22:03 EST Alessandro Casa, José E. Chacón, Giovanna Menardi. Source: Electronic Journal of Statistics, Volume 14, Number 1, 835--856.Abstract: Density-based clustering relies on the idea of linking groups to some specific features of the probability distribution underlying the data. The reference to a true, yet unknown, population structure allows framing the clustering problem in a standard inferential setting, where the concept of ideal population clustering is defined as the partition induced by the true density function. The nonparametric formulation of this approach, known as modal clustering, draws a correspondence between the groups and the domains of attraction of the density modes. Operationally, a nonparametric density estimate is required and a proper selection of the amount of smoothing, governing the shape of the density and hence possibly the modal structure, is crucial to identify the final partition. In this work, we address the issue of density estimation for modal clustering from an asymptotic perspective. A natural and easy to interpret metric to measure the distance between density-based partitions is discussed, its asymptotic approximation explored, and employed to study the problem of bandwidth selection for nonparametric modal clustering. Full Article
lust Profile likelihood biclustering By projecteuclid.org Published On :: Fri, 31 Jan 2020 04:01 EST Cheryl Flynn, Patrick Perry. Source: Electronic Journal of Statistics, Volume 14, Number 1, 731--768.Abstract: Biclustering, the process of simultaneously clustering the rows and columns of a data matrix, is a popular and effective tool for finding structure in a high-dimensional dataset. Many biclustering procedures appear to work well in practice, but most do not have associated consistency guarantees. To address this shortcoming, we propose a new biclustering procedure based on profile likelihood. The procedure applies to a broad range of data modalities, including binary, count, and continuous observations. We prove that the procedure recovers the true row and column classes when the dimensions of the data matrix tend to infinity, even if the functional form of the data distribution is misspecified. The procedure requires computing a combinatorial search, which can be expensive in practice. Rather than performing this search directly, we propose a new heuristic optimization procedure based on the Kernighan-Lin heuristic, which has nice computational properties and performs well in simulations. We demonstrate our procedure with applications to congressional voting records, and microarray analysis. Full Article
lust Path-Based Spectral Clustering: Guarantees, Robustness to Outliers, and Fast Algorithms By Published On :: 2020 We consider the problem of clustering with the longest-leg path distance (LLPD) metric, which is informative for elongated and irregularly shaped clusters. We prove finite-sample guarantees on the performance of clustering with respect to this metric when random samples are drawn from multiple intrinsically low-dimensional clusters in high-dimensional space, in the presence of a large number of high-dimensional outliers. By combining these results with spectral clustering with respect to LLPD, we provide conditions under which the Laplacian eigengap statistic correctly determines the number of clusters for a large class of data sets, and prove guarantees on the labeling accuracy of the proposed algorithm. Our methods are quite general and provide performance guarantees for spectral clustering with any ultrametric. We also introduce an efficient, easy to implement approximation algorithm for the LLPD based on a multiscale analysis of adjacency graphs, which allows for the runtime of LLPD spectral clustering to be quasilinear in the number of data points. Full Article
lust Connecting Spectral Clustering to Maximum Margins and Level Sets By Published On :: 2020 We study the connections between spectral clustering and the problems of maximum margin clustering, and estimation of the components of level sets of a density function. Specifically, we obtain bounds on the eigenvectors of graph Laplacian matrices in terms of the between cluster separation, and within cluster connectivity. These bounds ensure that the spectral clustering solution converges to the maximum margin clustering solution as the scaling parameter is reduced towards zero. The sensitivity of maximum margin clustering solutions to outlying points is well known, but can be mitigated by first removing such outliers, and applying maximum margin clustering to the remaining points. If outliers are identified using an estimate of the underlying probability density, then the remaining points may be seen as an estimate of a level set of this density function. We show that such an approach can be used to consistently estimate the components of the level sets of a density function under very mild assumptions. Full Article
lust Latent Simplex Position Model: High Dimensional Multi-view Clustering with Uncertainty Quantification By Published On :: 2020 High dimensional data often contain multiple facets, and several clustering patterns can co-exist under different variable subspaces, also known as the views. While multi-view clustering algorithms were proposed, the uncertainty quantification remains difficult --- a particular challenge is in the high complexity of estimating the cluster assignment probability under each view, and sharing information among views. In this article, we propose an approximate Bayes approach --- treating the similarity matrices generated over the views as rough first-stage estimates for the co-assignment probabilities; in its Kullback-Leibler neighborhood, we obtain a refined low-rank matrix, formed by the pairwise product of simplex coordinates. Interestingly, each simplex coordinate directly encodes the cluster assignment uncertainty. For multi-view clustering, we let each view draw a parameterization from a few candidates, leading to dimension reduction. With high model flexibility, the estimation can be efficiently carried out as a continuous optimization problem, hence enjoys gradient-based computation. The theory establishes the connection of this model to a random partition distribution under multiple views. Compared to single-view clustering approaches, substantially more interpretable results are obtained when clustering brains from a human traumatic brain injury study, using high-dimensional gene expression data. Full Article
lust Optimal Bipartite Network Clustering By Published On :: 2020 We study bipartite community detection in networks, or more generally the network biclustering problem. We present a fast two-stage procedure based on spectral initialization followed by the application of a pseudo-likelihood classifier twice. Under mild regularity conditions, we establish the weak consistency of the procedure (i.e., the convergence of the misclassification rate to zero) under a general bipartite stochastic block model. We show that the procedure is optimal in the sense that it achieves the optimal convergence rate that is achievable by a biclustering oracle, adaptively over the whole class, up to constants. This is further formalized by deriving a minimax lower bound over a class of biclustering problems. The optimal rate we obtain sharpens some of the existing results and generalizes others to a wide regime of average degree growth, from sparse networks with average degrees growing arbitrarily slowly to fairly dense networks with average degrees of order $sqrt{n}$. As a special case, we recover the known exact recovery threshold in the $log n$ regime of sparsity. To obtain the consistency result, as part of the provable version of the algorithm, we introduce a sub-block partitioning scheme that is also computationally attractive, allowing for distributed implementation of the algorithm without sacrificing optimality. The provable algorithm is derived from a general class of pseudo-likelihood biclustering algorithms that employ simple EM type updates. We show the effectiveness of this general class by numerical simulations. Full Article
lust High-Dimensional Inference for Cluster-Based Graphical Models By Published On :: 2020 Motivated by modern applications in which one constructs graphical models based on a very large number of features, this paper introduces a new class of cluster-based graphical models, in which variable clustering is applied as an initial step for reducing the dimension of the feature space. We employ model assisted clustering, in which the clusters contain features that are similar to the same unobserved latent variable. Two different cluster-based Gaussian graphical models are considered: the latent variable graph, corresponding to the graphical model associated with the unobserved latent variables, and the cluster-average graph, corresponding to the vector of features averaged over clusters. Our study reveals that likelihood based inference for the latent graph, not analyzed previously, is analytically intractable. Our main contribution is the development and analysis of alternative estimation and inference strategies, for the precision matrix of an unobservable latent vector Z. We replace the likelihood of the data by an appropriate class of empirical risk functions, that can be specialized to the latent graphical model and to the simpler, but under-analyzed, cluster-average graphical model. The estimators thus derived can be used for inference on the graph structure, for instance on edge strength or pattern recovery. Inference is based on the asymptotic limits of the entry-wise estimates of the precision matrices associated with the conditional independence graphs under consideration. While taking the uncertainty induced by the clustering step into account, we establish Berry-Esseen central limit theorems for the proposed estimators. It is noteworthy that, although the clusters are estimated adaptively from the data, the central limit theorems regarding the entries of the estimated graphs are proved under the same conditions one would use if the clusters were known in advance. As an illustration of the usage of these newly developed inferential tools, we show that they can be reliably used for recovery of the sparsity pattern of the graphs we study, under FDR control, which is verified via simulation studies and an fMRI data analysis. These experimental results confirm the theoretically established difference between the two graph structures. Furthermore, the data analysis suggests that the latent variable graph, corresponding to the unobserved cluster centers, can help provide more insight into the understanding of the brain connectivity networks relative to the simpler, average-based, graph. Full Article
lust Union of Low-Rank Tensor Spaces: Clustering and Completion By Published On :: 2020 We consider the problem of clustering and completing a set of tensors with missing data that are drawn from a union of low-rank tensor spaces. In the clustering problem, given a partially sampled tensor data that is composed of a number of subtensors, each chosen from one of a certain number of unknown tensor spaces, we need to group the subtensors that belong to the same tensor space. We provide a geometrical analysis on the sampling pattern and subsequently derive the sampling rate that guarantees the correct clustering under some assumptions with high probability. Moreover, we investigate the fundamental conditions for finite/unique completability for the union of tensor spaces completion problem. Both deterministic and probabilistic conditions on the sampling pattern to ensure finite/unique completability are obtained. For both the clustering and completion problems, our tensor analysis provides significantly better bound than the bound given by the matrix analysis applied to any unfolding of the tensor data. Full Article
lust A Bayesian sparse finite mixture model for clustering data from a heterogeneous population By projecteuclid.org Published On :: Mon, 04 May 2020 04:00 EDT Erlandson F. Saraiva, Adriano K. Suzuki, Luís A. Milan. Source: Brazilian Journal of Probability and Statistics, Volume 34, Number 2, 323--344.Abstract: In this paper, we introduce a Bayesian approach for clustering data using a sparse finite mixture model (SFMM). The SFMM is a finite mixture model with a large number of components $k$ previously fixed where many components can be empty. In this model, the number of components $k$ can be interpreted as the maximum number of distinct mixture components. Then, we explore the use of a prior distribution for the weights of the mixture model that take into account the possibility that the number of clusters $k_{mathbf{c}}$ (e.g., nonempty components) can be random and smaller than the number of components $k$ of the finite mixture model. In order to determine clusters we develop a MCMC algorithm denominated Split-Merge allocation sampler. In this algorithm, the split-merge strategy is data-driven and was inserted within the algorithm in order to increase the mixing of the Markov chain in relation to the number of clusters. The performance of the method is verified using simulated datasets and three real datasets. The first real data set is the benchmark galaxy data, while second and third are the publicly available data set on Enzyme and Acidity, respectively. Full Article
lust Variable selection methods for model-based clustering By projecteuclid.org Published On :: Thu, 26 Apr 2018 04:00 EDT Michael Fop, Thomas Brendan Murphy. Source: Statistics Surveys, Volume 12, 18--65.Abstract: Model-based clustering is a popular approach for clustering multivariate data which has seen applications in numerous fields. Nowadays, high-dimensional data are more and more common and the model-based clustering approach has adapted to deal with the increasing dimensionality. In particular, the development of variable selection techniques has received a lot of attention and research effort in recent years. Even for small size problems, variable selection has been advocated to facilitate the interpretation of the clustering results. This review provides a summary of the methods developed for variable selection in model-based clustering. Existing R packages implementing the different methods are indicated and illustrated in application to two data analysis examples. Full Article
lust Finite mixture models and model-based clustering By projecteuclid.org Published On :: Thu, 05 Aug 2010 15:41 EDT Volodymyr Melnykov, Ranjan MaitraSource: Statist. Surv., Volume 4, 80--116.Abstract: Finite mixture models have a long history in statistics, having been used to model population heterogeneity, generalize distributional assumptions, and lately, for providing a convenient yet formal framework for clustering and classification. This paper provides a detailed review into mixture models and model-based clustering. Recent trends as well as open problems in the area are also discussed. Full Article
lust Know Your Clients' behaviours: a cluster analysis of financial transactions. (arXiv:2005.03625v1 [econ.EM]) By arxiv.org Published On :: In Canada, financial advisors and dealers by provincial securities commissions, and those self-regulatory organizations charged with direct regulation over investment dealers and mutual fund dealers, respectively to collect and maintain Know Your Client (KYC) information, such as their age or risk tolerance, for investor accounts. With this information, investors, under their advisor's guidance, make decisions on their investments which are presumed to be beneficial to their investment goals. Our unique dataset is provided by a financial investment dealer with over 50,000 accounts for over 23,000 clients. We use a modified behavioural finance recency, frequency, monetary model for engineering features that quantify investor behaviours, and machine learning clustering algorithms to find groups of investors that behave similarly. We show that the KYC information collected does not explain client behaviours, whereas trade and transaction frequency and volume are most informative. We believe the results shown herein encourage financial regulators and advisors to use more advanced metrics to better understand and predict investor behaviours. Full Article
lust Predictive Modeling of ICU Healthcare-Associated Infections from Imbalanced Data. Using Ensembles and a Clustering-Based Undersampling Approach. (arXiv:2005.03582v1 [cs.LG]) By arxiv.org Published On :: Early detection of patients vulnerable to infections acquired in the hospital environment is a challenge in current health systems given the impact that such infections have on patient mortality and healthcare costs. This work is focused on both the identification of risk factors and the prediction of healthcare-associated infections in intensive-care units by means of machine-learning methods. The aim is to support decision making addressed at reducing the incidence rate of infections. In this field, it is necessary to deal with the problem of building reliable classifiers from imbalanced datasets. We propose a clustering-based undersampling strategy to be used in combination with ensemble classifiers. A comparative study with data from 4616 patients was conducted in order to validate our proposal. We applied several single and ensemble classifiers both to the original dataset and to data preprocessed by means of different resampling methods. The results were analyzed by means of classic and recent metrics specifically designed for imbalanced data classification. They revealed that the proposal is more efficient in comparison with other approaches. Full Article
lust Fair Algorithms for Hierarchical Agglomerative Clustering. (arXiv:2005.03197v1 [cs.LG]) By arxiv.org Published On :: Hierarchical Agglomerative Clustering (HAC) algorithms are extensively utilized in modern data science and machine learning, and seek to partition the dataset into clusters while generating a hierarchical relationship between the data samples themselves. HAC algorithms are employed in a number of applications, such as biology, natural language processing, and recommender systems. Thus, it is imperative to ensure that these algorithms are fair-- even if the dataset contains biases against certain protected groups, the cluster outputs generated should not be discriminatory against samples from any of these groups. However, recent work in clustering fairness has mostly focused on center-based clustering algorithms, such as k-median and k-means clustering. Therefore, in this paper, we propose fair algorithms for performing HAC that enforce fairness constraints 1) irrespective of the distance linkage criteria used, 2) generalize to any natural measures of clustering fairness for HAC, 3) work for multiple protected groups, and 4) have competitive running times to vanilla HAC. To the best of our knowledge, this is the first work that studies fairness for HAC algorithms. We also propose an algorithm with lower asymptotic time complexity than HAC algorithms that can rectify existing HAC outputs and make them subsequently fair as a result. Moreover, we carry out extensive experiments on multiple real-world UCI datasets to demonstrate the working of our algorithms. Full Article
lust Model assisted variable clustering: Minimax-optimal recovery and algorithms By projecteuclid.org Published On :: Mon, 17 Feb 2020 04:02 EST Florentina Bunea, Christophe Giraud, Xi Luo, Martin Royer, Nicolas Verzelen. Source: The Annals of Statistics, Volume 48, Number 1, 111--137.Abstract: The problem of variable clustering is that of estimating groups of similar components of a $p$-dimensional vector $X=(X_{1},ldots ,X_{p})$ from $n$ independent copies of $X$. There exists a large number of algorithms that return data-dependent groups of variables, but their interpretation is limited to the algorithm that produced them. An alternative is model-based clustering, in which one begins by defining population level clusters relative to a model that embeds notions of similarity. Algorithms tailored to such models yield estimated clusters with a clear statistical interpretation. We take this view here and introduce the class of $G$-block covariance models as a background model for variable clustering. In such models, two variables in a cluster are deemed similar if they have similar associations will all other variables. This can arise, for instance, when groups of variables are noise corrupted versions of the same latent factor. We quantify the difficulty of clustering data generated from a $G$-block covariance model in terms of cluster proximity, measured with respect to two related, but different, cluster separation metrics. We derive minimax cluster separation thresholds, which are the metric values below which no algorithm can recover the model-defined clusters exactly, and show that they are different for the two metrics. We therefore develop two algorithms, COD and PECOK, tailored to $G$-block covariance models, and study their minimax-optimality with respect to each metric. Of independent interest is the fact that the analysis of the PECOK algorithm, which is based on a corrected convex relaxation of the popular $K$-means algorithm, provides the first statistical analysis of such algorithms for variable clustering. Additionally, we compare our methods with another popular clustering method, spectral clustering. Extensive simulation studies, as well as our data analyses, confirm the applicability of our approach. Full Article
lust Generalized cluster trees and singular measures By projecteuclid.org Published On :: Tue, 21 May 2019 04:00 EDT Yen-Chi Chen. Source: The Annals of Statistics, Volume 47, Number 4, 2174--2203.Abstract: In this paper we study the $alpha $-cluster tree ($alpha $-tree) under both singular and nonsingular measures. The $alpha $-tree uses probability contents within a set created by the ordering of points to construct a cluster tree so that it is well defined even for singular measures. We first derive the convergence rate for a density level set around critical points, which leads to the convergence rate for estimating an $alpha $-tree under nonsingular measures. For singular measures, we study how the kernel density estimator (KDE) behaves and prove that the KDE is not uniformly consistent but pointwise consistent after rescaling. We further prove that the estimated $alpha $-tree fails to converge in the $L_{infty }$ metric but is still consistent under the integrated distance. We also observe a new type of critical points—the dimensional critical points (DCPs)—of a singular measure. DCPs are points that contribute to cluster tree topology but cannot be defined using density gradient. Building on the analysis of the KDE and DCPs, we prove the topological consistency of an estimated $alpha $-tree. Full Article
lust A hierarchical Bayesian model for single-cell clustering using RNA-sequencing data By projecteuclid.org Published On :: Wed, 16 Oct 2019 22:03 EDT Yiyi Liu, Joshua L. Warren, Hongyu Zhao. Source: The Annals of Applied Statistics, Volume 13, Number 3, 1733--1752.Abstract: Understanding the heterogeneity of cells is an important biological question. The development of single-cell RNA-sequencing (scRNA-seq) technology provides high resolution data for such inquiry. A key challenge in scRNA-seq analysis is the high variability of measured RNA expression levels and frequent dropouts (missing values) due to limited input RNA compared to bulk RNA-seq measurement. Existing clustering methods do not perform well for these noisy and zero-inflated scRNA-seq data. In this manuscript we propose a Bayesian hierarchical model, called BasClu, to appropriately characterize important features of scRNA-seq data in order to more accurately cluster cells. We demonstrate the effectiveness of our method with extensive simulation studies and applications to three real scRNA-seq datasets. Full Article
lust Reliable clustering of Bernoulli mixture models By projecteuclid.org Published On :: Fri, 31 Jan 2020 04:06 EST Amir Najafi, Seyed Abolfazl Motahari, Hamid R. Rabiee. Source: Bernoulli, Volume 26, Number 2, 1535--1559.Abstract: A Bernoulli Mixture Model (BMM) is a finite mixture of random binary vectors with independent dimensions. The problem of clustering BMM data arises in a variety of real-world applications, ranging from population genetics to activity analysis in social networks. In this paper, we analyze the clusterability of BMMs from a theoretical perspective, when the number of clusters is unknown. In particular, we stipulate a set of conditions on the sample complexity and dimension of the model in order to guarantee the Probably Approximately Correct (PAC)-clusterability of a dataset. To the best of our knowledge, these findings are the first non-asymptotic bounds on the sample complexity of learning or clustering BMMs. Full Article
lust Box 3: Children's book illustrations by various artists, Peg Maltby and Dorothy Wall, , ca. 1932-1975 By feedproxy.google.com Published On :: 8/05/2015 2:13:13 PM Full Article
lust Box 4: Children's book illustrations by various artists, Dorothy Wall, ca. 1932 By feedproxy.google.com Published On :: 8/05/2015 2:26:30 PM Full Article
lust Box 6: Children's book illustrations by various artists, Dorothy Wall and Noela Young, ca. 1932-1964 By feedproxy.google.com Published On :: 8/05/2015 2:37:07 PM Full Article
lust Sydney in 1848 : illustrated by copper-plate engravings of its principal streets, public buildings, churches, chapels, etc. / from drawings by Joseph Fowles. By feedproxy.google.com Published On :: 28/04/2016 12:00:00 AM Full Article
lust Comment: “Models as Approximations I: Consequences Illustrated with Linear Regression” by A. Buja, R. Berk, L. Brown, E. George, E. Pitkin, L. Zhan and K. Zhang By projecteuclid.org Published On :: Wed, 08 Jan 2020 04:00 EST Roderick J. Little. Source: Statistical Science, Volume 34, Number 4, 580--583. Full Article
lust Models as Approximations I: Consequences Illustrated with Linear Regression By projecteuclid.org Published On :: Wed, 08 Jan 2020 04:00 EST Andreas Buja, Lawrence Brown, Richard Berk, Edward George, Emil Pitkin, Mikhail Traskin, Kai Zhang, Linda Zhao. Source: Statistical Science, Volume 34, Number 4, 523--544.Abstract: In the early 1980s, Halbert White inaugurated a “model-robust” form of statistical inference based on the “sandwich estimator” of standard error. This estimator is known to be “heteroskedasticity-consistent,” but it is less well known to be “nonlinearity-consistent” as well. Nonlinearity, however, raises fundamental issues because in its presence regressors are not ancillary, hence cannot be treated as fixed. The consequences are deep: (1) population slopes need to be reinterpreted as statistical functionals obtained from OLS fits to largely arbitrary joint ${x extrm{-}y}$ distributions; (2) the meaning of slope parameters needs to be rethought; (3) the regressor distribution affects the slope parameters; (4) randomness of the regressors becomes a source of sampling variability in slope estimates of order $1/sqrt{N}$; (5) inference needs to be based on model-robust standard errors, including sandwich estimators or the ${x extrm{-}y}$ bootstrap. In theory, model-robust and model-trusting standard errors can deviate by arbitrary magnitudes either way. In practice, significant deviations between them can be detected with a diagnostic test. Full Article
lust The Importance of Being Clustered: Uncluttering the Trends of Statistics from 1970 to 2015 By projecteuclid.org Published On :: Thu, 18 Jul 2019 22:01 EDT Laura Anderlucci, Angela Montanari, Cinzia Viroli. Source: Statistical Science, Volume 34, Number 2, 280--300.Abstract: In this paper, we retrace the recent history of statistics by analyzing all the papers published in five prestigious statistical journals since 1970, namely: The Annals of Statistics , Biometrika , Journal of the American Statistical Association , Journal of the Royal Statistical Society, Series B and Statistical Science . The aim is to construct a kind of “taxonomy” of the statistical papers by organizing and clustering them in main themes. In this sense being identified in a cluster means being important enough to be uncluttered in the vast and interconnected world of the statistical research. Since the main statistical research topics naturally born, evolve or die during time, we will also develop a dynamic clustering strategy, where a group in a time period is allowed to migrate or to merge into different groups in the following one. Results show that statistics is a very dynamic and evolving science, stimulated by the rise of new research questions and types of data. Full Article
lust Children's Book Author and Illustrator Tomie dePaola Dies at 85 By www.smithsonianmag.com Published On :: Wed, 01 Apr 2020 14:12:18 +0000 Over his five-decade-plus career, the "Strega Nona" author contributed to more than 270 books Full Article
lust 1 new case of COVID-19 in Manitoba connected with Brandon trucking company cluster By www.cbc.ca Published On :: Fri, 8 May 2020 13:23:40 EDT Eight COVID-19 cases are now connected to that workplace, including six employees. Full Article News/Canada/Manitoba
lust An Illustrated Letter for Mother’s Day By blogs.loc.gov Published On :: Thu, 07 May 2020 13:55:34 +0000 While traveling in Israel in 1948, Leonard Bernstein wrote a letter to his mother with beautiful illustrations by artist Jossi Stern. In anticipation of Mother's Day weekend, "In the Muse" highlights that digitized letter from the Leonard Bernstein Collection and encourages readers to send illustrated letters of their own. Full Article Collections Holidays
lust 'X-ray teardown' of iPad Pro Magic Keyboard illustrates complex engineering By appleinsider.com Published On :: Thu, 07 May 2020 13:08:24 -0400 Repair site iFixit has shared x-ray photographs of the new Magic Keyboard for iPad Pro, and they reveal an accessory more complicated than it might appear from the outside. Full Article iPadOS
lust Clustering of Risk Factors: A Simple Method of Detecting Cardiovascular Disease in Youth By pediatrics.aappublications.org Published On :: 2011-01-17T04:01:37-08:00 Cardiovascular risk factors predict the development of premature atherosclerosis. As the number of risk factors increases, so does the extent of these lesions. Assessment of cardiovascular risk factors is an accepted practice in adults but is not used in pediatrics. In this study, the authors discuss how the presence of ≥2 cardiovascular risk factors is associated with vascular changes in adolescents. The findings were compared with the Patholobiological Determinants of Atherosclerosis in Youth risk score to demonstrate that a simple method of clustering is a reliable tool to use in clinical practice. (Read the full article) Full Article
lust Peer-led Education for Adolescents With Asthma in Jordan: A Cluster-Randomized Controlled Trial By pediatrics.aappublications.org Published On :: 2011-12-12T00:08:59-08:00 The prevalence of asthma and smoking among adolescents in Jordan is high. Well-designed, school-based, peer-led education programs can have a positive impact on asthma self-management in adolescents. Student peer leaders can be useful and responsible partners in health promotion programs.A peer-led asthma education program —Adolescent Asthma Action—for adolescents developed in Australia was adapted to suit non–English-speaking cultures in the Middle East. Peer-led education led to improved self-management of asthma and motivated students to avoid smoking. (Read the full article) Full Article
lust Identifying and Treating a Substandard Housing Cluster Using a Medical-Legal Partnership By pediatrics.aappublications.org Published On :: 2012-10-22T00:07:40-07:00 Social and environmental risks related to substandard housing contribute to adverse health outcomes. Partnerships between the health care and legal systems can help families address such risks and help clinicians understand the legal context of health.A medical-legal partnership colocated in a pediatric primary care setting identified and treated a large cluster of poor quality, substandard housing. Housing improvements were possible because of strong collaboration between clinicians, attorneys, community partners, and families. (Read the full article) Full Article
lust Near-Infrared Imaging in Intravenous Cannulation in Children: A Cluster Randomized Clinical Trial By pediatrics.aappublications.org Published On :: 2012-12-10T00:07:59-08:00 Gaining intravenous access in children can be difficult. Recently, several near-infrared devices have been introduced attempting to support intravenous cannulation by visualizing veins underneath skin. Only one of those devices has been evaluated systemically thus far and results are inconclusive.Although it was possible to visualize veins with near-infrared in most patients, the VascuLuminator did not improve the success of cannulation. An explanation is that the main problem is probably not localization of the vein but insertion of the cannula. (Read the full article) Full Article
lust Chlorhexidine Cleansing of the Umbilical Cord and Separation Time: A Cluster-Randomized Trial By pediatrics.aappublications.org Published On :: 2013-03-18T00:07:05-07:00 Chlorhexidine cleansing of the cord can reduce mortality in high-risk settings. Time to separation may increase with topical applications of chlorhexidine; 1 previous community trial quantified this increase and did not measure whether caretakers perceived the delay.Single and multiple cleansing of the umbilical cord increases time to separation by ~50%, or an average of 2 to 2.5 days. Caretakers were able to detect this difference and expressed dissatisfaction, while still accepting the intervention. (Read the full article) Full Article
lust Cluster (School) RCT of ParentCorps: Impact on Kindergarten Academic Achievement By pediatrics.aappublications.org Published On :: 2013-04-15T00:06:42-07:00 At least half of the achievement gap for low-income, minority children is present at kindergarten entry; however, there are no population-level early childhood interventions that effectively engage and support families and teachers to ameliorate the impact of adversity on achievement.This study evaluated ParentCorps, a family-centered, school-based intervention to promote self-regulation and learning for all children entering school in disadvantaged, urban neighborhoods. ParentCorps results in higher kindergarten achievement among low-income, minority children. (Read the full article) Full Article
lust Comorbidity Clusters in Autism Spectrum Disorders: An Electronic Health Record Time-Series Analysis By pediatrics.aappublications.org Published On :: 2013-12-09T00:06:36-08:00 Individuals with autism spectrum disorders have a higher comorbidity burden than the general pediatric population, including higher rates of seizures, psychiatric illness, and gastrointestinal disorders.Comorbidities do not occur evenly. Our clustering analysis reveals subgroups characterized by seizure, psychiatric disorders, and complex multisystem disorders including auditory and gastrointestinal disorders. Correlations between seizure, psychiatric disorders, and gastrointestinal disorders are validated on a sample from a second hospital. (Read the full article) Full Article
lust Collaborative Care Outcomes for Pediatric Behavioral Health Problems: A Cluster Randomized Trial By pediatrics.aappublications.org Published On :: 2014-03-24T00:06:20-07:00 Integrated or collaborative care intervention models have revealed gains in provider care processes and outcomes in adult, child, and adolescent populations with mental health disorders. However optimistic, conclusions are not definitive due to methodologic limitations and a dearth of studies.This randomized trial provides further evidence for the efficacy of an on-site intervention (Doctor Office Collaborative Care) coordinated by care managers for children's behavior problems. The findings provide support for integrated behavioral health care using novel provider and caregiver outcomes. (Read the full article) Full Article
lust Strength Capacity and Cardiometabolic Risk Clustering in Adolescents By pediatrics.aappublications.org Published On :: 2014-03-31T00:06:59-07:00 Resistance exercise is known to have a robust effect on glycemic control and cardiometabolic health among children and adolescents, even in the absence of weight loss.Normalized strength capacity is associated with lower cardiometabolic risk clustering in boys and girls, even after adjustment for cardiorespiratory fitness, level of physical activity, and BMI. (Read the full article) Full Article
lust Adoption of Cardiovascular Risk Reduction Guidelines: A Cluster-Randomized Trial By pediatrics.aappublications.org Published On :: 2014-08-25T00:07:25-07:00 Cardiovascular risk begins in childhood. New clinical guidelines established a care strategy for lowering risks. Incorporation of guidelines into routine practice lags due to barriers related to knowledge and attitudes about guidelines, as well as behaviors of practitioners, patients, and clinical systems.This study demonstrated that a multifaceted approach including tools, education, and support for changes in practice systems can accelerate the adoption of guidelines during routine pediatric well-child visits, compared with dissemination of the guidelines alone. (Read the full article) Full Article
lust A School Health Center Intervention for Abusive Adolescent Relationships: A Cluster RCT By pediatrics.aappublications.org Published On :: 2014-12-22T00:06:48-08:00 Adolescent relationship abuse (ARA) is prevalent in confidential clinic settings such as school health centers (SHCs) and is associated with poor health outcomes. No evidence-based interventions target reduction of ARA in the SHC setting.This study provides the first evidence of the potential benefits of a brief provider-delivered universal education and counseling intervention in SHCs to address and prevent a major public health problem: ARA. (Read the full article) Full Article
lust Registry-Linked Electronic Influenza Vaccine Provider Reminders: A Cluster-Crossover Trial By pediatrics.aappublications.org Published On :: 2014-12-29T00:06:46-08:00 Frequency of influenza vaccination is low, partially because of missed opportunities to vaccinate. Barriers to implementing successful influenza vaccination reminders in the electronic health record include alert fatigue and incomplete vaccination information due to scattered records.A noninterruptive, immunization information system–linked influenza vaccination reminder can increase vaccination late in the winter when fewer vaccine doses are usually administered. Tailoring the reminder to clinicians’ needs can increase its use. (Read the full article) Full Article
lust Addressing Social Determinants of Health at Well Child Care Visits: A Cluster RCT By pediatrics.aappublications.org Published On :: 2015-01-05T00:06:55-08:00 Although pediatric professional guidelines emphasize addressing a child’s social environment in the context of well child care, it remains unclear whether screening for unmet basic needs at visits increases low-income families’ receipt of community-based resources.This study demonstrates that systematically screening and referring for social determinants of health during primary care can lead to the receipt of more community resources for families. (Read the full article) Full Article