How many independent bets are there?

The benefits of portfolio diversification is a central tenet implicit to modern financial theory and practice. Linked to diversification is the notion of breadth. Breadth is correctly thought of as the number of in- dependent bets available to an investor. Conventionally applications us- ing breadth frequently assume only the number of separate bets. There may be a large discrepancy between these two interpretations. We uti- lize a simple singular-value decomposition (SVD) and the Keiser-Gutman stopping criterion to select the integer-valued effective dimensionality of the correlation matrix of returns. In an emerging market such as South African we document an estimated breadth that is considerably lower than anticipated. This lack of diversification may be because of market concentration, exposure to the global commodity cycle and local currency volatility. We discuss some practical extensions to a more statistically correct interpretation of market breadth, and its theoretical implications for both global and domestic investors.Comment: Less technical rewrite. 12 Pages, 6 Figures (.eps

Inherited predisposition to spontaneous preterm delivery

Peer reviewedPreprin

Enabling Big Data Analytics at Manufacturing Fields of Farplas Automotive

Digitization and data-driven manufacturing process is needed for today's industry. The term Industry 4.0 stands for today industrial digitization which is defined as a new level of organization and control over the entire value chain of the life cycle of products; it is geared towards increasingly individualized customer's high-quality expectations. However, due to the increase in the number of connected devices and the variety of data, it has become difficult to store and analyze data with conventional systems. The motivation of this paper is to provide an overview of the understanding of the big data pipeline, providing a real-time on-premise data acquisition, data compression, data storage and processing with Apache Kafka and Apache Spark implementation on Apache Ha-doop cluster, and identifying the challenges and issues occurring with implementation the Farplas manufacturing company, which is one of the biggest Tier 1 automotive supplier in Turkey, to study the new trends and streams related to topics via Industry 4.0.Comment: 8 page

Correlation length scalings in fusion edge plasma turbulence computations

The effect of changes in plasma parameters, that are characteristic near or at an L-H transition in fusion edge plasmas, on fluctuation correlation lengths are analysed by means of drift-Alfven turbulence computations. Scalings by density gradient length, collisionality, plasma beta, and by an imposed shear flow are considered. It is found that strongly sheared flows lead to the appearence of long-range correlations in electrostatic potential fluctuations parallel and perpendicular to the magnetic field.Comment: Submitted to "Plasma Physics and Controlled Fusion

CONSUMIDORES DE BAIXA RENDA E COMPRAS ON-LINE: RECEIOS EM CONSUMIR PELA INTERNET

The growth in access of low income consumers to the internet has taken them to use the net in search of entertainment, education and relationships. However, consuming online is still an activity surrounded by distrust. The present study aims to discuss the reasons why low income consumers have apprehension in consuming through the internet. For this, in depth interviews were conducted with 23 low income consumers. The collected data shows that the internet is still seen by the interviewees as being, mainly, for leisure and entertainment. Online shopping still is a task they fear, because of different motives. Initially, one can point the preference to consume in physical stores, since the consumers can touch the desired product, enjoy the trip to the store as a moment of pleasure and the possibility of interacting with salesmen, who help them in their choice. The apprehensions in buying online are also influenced by the perception that sites are not safe, because they offer threats, such as viruses or theft of personal information. Furthermore, interviewees believe that online stores are not compromised with their customers, since they permit problems to occur in the delivery of merchandise, are not clear about the shopping process, and create difficulties in payment method. Another reason for them not to buy online is the perception that if a negative consuming episode of online shopping happened to someone they know, it is also bound to happen with them. Despite this reasoning, these consumers point the importance of help from a third party in their reference group as main incentive for them to face the obstacles to consuming through the internet. In conclusion, it is possible to consider that low income consumers have apprehensions that are similar to their higher income peers, but, also, show different feelings, which are seldom discussed in the literature about online shopping.El mayor acceso de consumidores de baja renta a Internet los lleva a utilizar la red virtual para buscar entretenimiento, educación y relaciones sociales. El consumo on-line, entretanto, todavía presenta desconfianzas. El presente trabajo tiene como objetivo analizar los motivos por los cuales la población de baja renta siente temor al realizar compras on-line. Para eso, entrevistas en profundidad fueron realizadas con 23 consumidores de baja renta. A partir de los datos recolectados, se percibe que Internet es un medio visto por los entrevistados como siendo, especialmente, de ocio y entretenimiento. Comprar on-line todavía es una tarea que temen por diferentes motivos. Inicialmente, se puede apuntar la preferencia por consumir en tiendas físicas, pues en ellas los consumidores pueden tocar los productos deseados, aprovechar la ida a la tienda como un momento de placer e interactuar con vendedores, que los ayudan a elegir los productos. Los temores al comprar por Internet también son influenciados por la visión de los entrevistados de que sites no son seguros, pues ofrecen amenazas, tales como virus o robo de informaciones personales. Además, creen que tiendas en Internet no tienen compromiso con sus clientes, pues permiten que ocurran problemas en la entrega de mercaderías, no dejan claras las informaciones sobre el proceso de compra y no facilitan las formas de pago. Otro motivo para no adquirir en Internet es la percepción de que, si un episodio negativo de consumo por Internet ocurrió con algún conocido, lo mismo le ocurrirá al entrevistado. A pesar de tal temor, esos consumidores apuntan la importancia de la ayuda de un tercero en sus grupos de referencia como principal incentivo para que ellos enfrenten las barreras ante el consumo por Internet. De esa forma, es posible considerar que consumidores de baja renta poseen temores similares a los de sus pares de niveles de renta más elevados, mas, también, presentan sentimientos que son diferentes, poco discutidos por la literatura sobre consumo en InternetO maior acesso de consumidores de baixa renda à internet os leva a utilizar a rede virtual para buscar entretenimento, educação e relacionamentos. O consumo on-line, entretanto, ainda é envolto de desconfianças. O presente trabalho tem como objetivo analisar os motivos pelos quais a população de baixa renda tem receios em realizar compras on-line. Para isso, entrevistas em profundidade foram realizadas com 23 consumidores de baixa renda. A partir dos dados coletados, percebe-se que a internet é um meio visto pelos entrevistados como sendo, especialmente, de lazer e entretenimento. Comprar on-line ainda é uma tarefa que receiam, por diferentes motivos. Inicialmente, pode-se apontar a preferência por consumir em lojas físicas, pois nelas os consumidores podem tocar nos produtos desejados, aproveitar a ida à loja como um momento de prazer e interagir com vendedores, que os ajudam em suas escolhas. Os receios em comprar pela internet também são influenciados pela visão dos entrevistados de que sites não são seguros, pois oferecem ameaças, tais como vírus ou roubo de informações pessoais. Além disso, acreditam que lojas na internet não são compromissadas com seus clientes, pois permitem que ocorram problemas na entrega de mercadorias, não deixam claras as informações a respeito do processo de compras e dificultam as formas de pagamento. Outro motivo para não comprarem na internet é a percepção de que, se um episódio negativo de consumo pela internet ocorreu com algum conhecido, o mesmo também ocorrerá com eles. Apesar de tal receio, esses consumidores apontam a importância da ajuda de um terceiro em seus grupos de referência como principal incentivo para que eles enfrentem as barreiras ao consumo pela internet. Dessa forma, é possível considerar que consumidores de baixa renda possuem receios similares aos de seus pares de níveis de renda mais elevados, mas também apresentam sentimentos que são diferentes, pouco discutidos pela literatura sobre consumo na internet

Statistical analysis plan for the COMPARE trial: a 3-arm randomised controlled trial comparing the effectiveness of Constraint-induced Aphasia Therapy Plus and Multi-modality Aphasia Therapy to usual care in chronic post-stroke aphasia (COMPARE)

BackgroundWhile high-quality meta-analyses have confirmed the effectiveness of aphasia therapy after stroke, there is limited evidence for the comparative effectiveness of different aphasia interventions. Two commonly used interventions, Constraint-induced Aphasia Therapy Plus (CIAT Plus) and Multi-modality Aphasia Therapy (M-MAT), are hypothesised to rely on diverse underlying neural mechanisms for recovery and may be differentially responsive to aphasia severity. COMPARE is a prospective randomised open-blinded end-point trial designed to determine whether, in people with chronic post-stroke aphasia living in the community, CIAT Plus and M-MAT provide greater therapeutic benefit compared to usual care, are differentially effective according to aphasia severity, and are cost-effective. This paper details the statistical analysis plan for the COMPARE trial developed prior to data analysis.MethodsParticipants (n = 216) are randomised to one of three arms, CIAT Plus, M-MAT or usual care, and undertake therapy with a study trained speech pathologist in groups of three participants stratified by aphasia severity. Therapy occurs for 3 h blocks per day for 10 days across 2 weeks. The primary clinical outcome is aphasia severity as measured by the Western Aphasia Battery-Revised Aphasia Quotient (WAB-R-AQ) immediately post intervention. Secondary outcomes include WAB-R-AQ at 12-week follow-up, and functional communication, discourse efficiency, multimodal communication, and health-related quality of life immediately post intervention and at 12-week follow-up.ResultsLinear mixed models (LMMs) will be used to analyse differences between M-MAT and UC, and CIAT-Plus and UC on each outcome measure immediately and at 12 weeks post-intervention. The LMM for WAB-R-AQ will assess the differences in efficacy between M-MAT and CIAT-Plus. All analyses will control for baseline aphasia severity (fixed effect) and for the clustering effect of treatment groups (random effect).DiscussionThis trial will provide relative effectiveness data for two common interventions for people with chronic post-stroke aphasia, and highlight possible differential effects based on aphasia severity. Together with the health economic analysis data, the results will enable more informed personalised prescription for aphasia therapy after stroke.Trial registrationAustralian New Zealand Clinical Trials Registry: ACTRN 12615000618550 . Registered on 15 June 2016

Parental education and the risk of cerebral palsy for children:an evaluation of causality

Aim To explore whether increasing parental education has a causal effect on risk of cerebral palsy (CP) in the child, or whether unobserved confounding is a more likely explanation. Method We used data from Norwegian registries on approximately 1.5 million children born between 1967 and 2011. We compared results from a traditional cohort design with results from a family‐based matched case–control design, in which children with CP were matched to their first cousins without CP. In addition, we performed a simulation study to assess the role of unobserved confounding. Results In the cohort design, the odds of CP were reduced in children of mothers and fathers with higher education (adjusted odds ratio [OR] 0.67, 95% confidence interval [CI] 0.60–0.75 for maternal education, and adjusted OR 0.75, 95% CI 0.67–0.85 for paternal education). In the family‐based case–control design, only an association for maternal education remained (adjusted OR 0.80, 95% CI 0.64–0.99). Results from a simulation study suggested that this association could be explained by unobserved confounding. Interpretation A causal effect of obtaining higher education on risk of CP in the child is unlikely. Results stress the importance of continued research on the role of genetic and environmental risk factors that vary by parents’ educational level.publishedVersio

Parametric study of EEG sensitivity to phase noise during face processing

<b>Background: </b> The present paper examines the visual processing speed of complex objects, here faces, by mapping the relationship between object physical properties and single-trial brain responses. Measuring visual processing speed is challenging because uncontrolled physical differences that co-vary with object categories might affect brain measurements, thus biasing our speed estimates. Recently, we demonstrated that early event-related potential (ERP) differences between faces and objects are preserved even when images differ only in phase information, and amplitude spectra are equated across image categories. Here, we use a parametric design to study how early ERP to faces are shaped by phase information. Subjects performed a two-alternative force choice discrimination between two faces (Experiment 1) or textures (two control experiments). All stimuli had the same amplitude spectrum and were presented at 11 phase noise levels, varying from 0% to 100% in 10% increments, using a linear phase interpolation technique. Single-trial ERP data from each subject were analysed using a multiple linear regression model. <b>Results: </b> Our results show that sensitivity to phase noise in faces emerges progressively in a short time window between the P1 and the N170 ERP visual components. The sensitivity to phase noise starts at about 120–130 ms after stimulus onset and continues for another 25–40 ms. This result was robust both within and across subjects. A control experiment using pink noise textures, which had the same second-order statistics as the faces used in Experiment 1, demonstrated that the sensitivity to phase noise observed for faces cannot be explained by the presence of global image structure alone. A second control experiment used wavelet textures that were matched to the face stimuli in terms of second- and higher-order image statistics. Results from this experiment suggest that higher-order statistics of faces are necessary but not sufficient to obtain the sensitivity to phase noise function observed in response to faces. <b>Conclusion: </b> Our results constitute the first quantitative assessment of the time course of phase information processing by the human visual brain. We interpret our results in a framework that focuses on image statistics and single-trial analyses

Theoretical and Experimental Study of the Vibration of Axisymmetric Viscous Liquid Bridges

n this paper the dynamics of axisymmetric liquid columns held by capillary forces between two circular, concentric, solid disks is considered. The problem has been solved by using a one‐dimensional model known in the literature as the Cosserat model, which includes viscosity effects, where the axial velocity is considered constant in each section of the liquid bridge. The dynamic response of the bridge to an excitation consisting of a small‐amplitude vibration of the supporting disks has been solved by linearizing the Cosserat model. It has been assumed that such excitation is harmonic so that the analysis has been performed in the frequency domain. The particular case of a cylindrical liquid bridge has been analytically studied and the transfer function has been calculated in the cases of oscillation of both disks (either in phase or in counterphase) or only of one of them. The resolution of the general formulation for a noncylindrical liquid bridge has been numerically made by using an implicit finite difference method. In this case, the influence of the volume of the liquid column and of the residual gravity level on the first resonance has been studied, and the results compared, for the inviscid case, with other potential models, both one and three dimensional. To demonstrate the usefulness of this theoretical model in predicting the vibrational behavior of axisymmetric viscous liquid bridges, some experiments have been performed by using the neutral buoyancy technique (also known as the Plateau technique) to simulate reduced gravity conditions, with good agreement between the results of the model and experiments

Integrated Ecosystem Assessment: Lake Ontario Water Management

BACKGROUND: Ecosystem management requires organizing, synthesizing, and projecting information at a large scale while simultaneously addressing public interests, dynamic ecological properties, and a continuum of physicochemical conditions. We compared the impacts of seven water level management plans for Lake Ontario on a set of environmental attributes of public relevance. METHODOLOGY AND FINDINGS: Our assessment method was developed with a set of established impact assessment tools (checklists, classifications, matrices, simulations, representative taxa, and performance relations) and the concept of archetypal geomorphic shoreline classes. We considered each environmental attribute and shoreline class in its typical and essential form and predicted how water level change would interact with defining properties. The analysis indicated that about half the shoreline of Lake Ontario is potentially sensitive to water level change with a small portion being highly sensitive. The current water management plan may be best for maintaining the environmental resources. In contrast, a natural water regime plan designed for greatest environmental benefits most often had adverse impacts, impacted most shoreline classes, and the largest portion of the lake coast. Plans that balanced multiple objectives and avoided hydrologic extremes were found to be similar relative to the environment, low on adverse impacts, and had many minor impacts across many shoreline classes. SIGNIFICANCE: The Lake Ontario ecosystem assessment provided information that can inform decisions about water management and the environment. No approach and set of methods will perfectly and unarguably accomplish integrated ecosystem assessment. For managing water levels in Lake Ontario, we found that there are no uniformly good and bad options for environmental conservation. The scientific challenge was selecting a set of tools and practices to present broad, relevant, unbiased, and accessible information to guide decision-making on a set of management options