WorldWideScience

Sample records for exploratory spatial analysis

  1. Using GIS for spatial exploratory analysis of borehole data: a ...

    African Journals Online (AJOL)

    Using GIS for spatial exploratory analysis of borehole data: a firsthand approach towards groundwater development. C. Gyamfi, J. M. Ndambuki, P. Y. Diabene, G. E. Kifanyi, C. R. Githuku, A. Alexander ...

  2. [Spatial exploratory analysis of road accidents in Ciudad Juarez, Mexico].

    Science.gov (United States)

    Hernández Hernández, Vladimir

    2012-05-01

    Prepare a tool for the exploratory study of road accidents in Ciudad Juarez, Chihuahua, Mexico, that exclusively applies the spatial geographical variable (location). Observational and cross-sectional study that uses a Geographic Information System to explore the spatial nature of 13 305 road accidents recorded during 2008 and 2009 in Ciudad Juarez. Indicators were constructed that approximated the transit flow and included two variables: indices of the level of urbanization and population density. The value of the global spatial autocorrelation was positive, indicating the presence of groupings that were identified through the spatial association indicators. There are road risk clusters located in areas with a high level of urbanization, low population density, and a high transit flow level. The exploratory analysis of spatial data is a phase that precedes the use of multivariate techniques with a broader scope. The application of exploratory analysis techniques in itself makes it possible to standardize spatial groupings, identify global autocorrelation, and indicate the direction of the variables under study.

  3. Exploratory analysis of spatial and temporal data a systematic approach

    CERN Document Server

    Andrienko, Natalia

    2006-01-01

    Exploratory data analysis (EDA) is about detecting and describing patterns, trends, and relations in data, motivated by certain purposes of investigation. As something relevant is detected in data, new questions arise, causing specific parts to be viewed in more detail. So EDA has a significant appeal: it involves hypothesis generation rather than mere hypothesis testing. The authors describe in detail and systemize approaches, techniques, and methods for exploring spatial and temporal data in particular. They start by developing a general view of data structures and characteristics and then build on top of this a general task typology, distinguishing between elementary and synoptic tasks. This typology is then applied to the description of existing approaches and technologies, resulting not just in recommendations for choosing methods but in a set of generic procedures for data exploration. Professionals practicing analysis will profit from tested solutions - illustrated in many examples - for reuse in the c...

  4. An exploratory spatial analysis of social vulnerability and smoke plum dispersion in the U.S

    Science.gov (United States)

    Cassandra Johnson Gaither; Scott Goodrick; Bryn Elise Murphy; Neelam Poudyal

    2015-01-01

    This study explores the spatial association between social vulnerability and smoke plume dispersion at the census block group level for the 13 southern states in the USDA Forest Service’s Region 8. Using environmental justice as a conceptual basis, we use Exploratory Spatial Data Analysis to identify clusters or “hot spots” for the incidence of both higher than average...

  5. GeoXp : An R Package for Exploratory Spatial Data Analysis

    Directory of Open Access Journals (Sweden)

    Thibault Laurent

    2012-04-01

    Full Text Available We present GeoXp, an R package implementing interactive graphics for exploratory spatial data analysis. We use a data set concerning public schools of the French MidiPyrenees region to illustrate the use of these exploratory techniques based on the coupling between a statistical graph and a map. Besides elementary plots like boxplots,histograms or simple scatterplots, GeoXp also couples maps with Moran scatterplots, variogram clouds, Lorenz curves and other graphical tools. In order to make the most of the multidimensionality of the data, GeoXp includes dimension reduction techniques such as principal components analysis and cluster analysis whose results are also linked to the map.

  6. Exploratory Analysis of Spatial-Temporal Patterns of Air Pollution in the City

    Science.gov (United States)

    Champendal, Alexandre; Kanevski, Mikhail; Huguenot, Pierre-Emmanuel; Golay, Jean

    2013-04-01

    Air pollution in the city is an important problem influencing environment, well-being of society, economy, management of urban zones, etc. The problem is extremely difficult due to a very complex distribution of the pollution sources, morphology of the city and dispersion processes leading to multivariate nature of the phenomena and high local spatial-temporal variability. The task of understanding, modelling and prediction of spatial-temporal patterns of air pollution in urban zones is an interesting and challenging topic having many research axes from science-based modelling to geostatistics and data mining. The present research mainly deals with a comprehensive exploratory analysis of spatial-temporal air pollution data using statistical, geostatistical and machine learning tools. This analysis helps to 1) understand and model spatial-temporal correlations using variography, 2) explore the temporal evolution of spatial correlation matrix; 3) analyse and visualize an interconnection between measurement stations using network science tools; 4) quantify the availability and predictability of structured patterns. The real data case study deals with spatial-temporal air pollution data of canton Geneva (2002-2011). Carbon dioxide (NO2) have caught our attention. It has effects on health: nitrogen dioxide can irritate the lungs, effects on plants; NO2 contributes to the phenomenon of acid rain. The negative effects of nitrogen dioxides on plants are reducing the growth, production and pesticide resistance. And finally the effects on materials: nitrogen dioxides increase the corrosion. Well-defined patterns of spatial-temporal correlations were detected. The analysis and visualization of spatial correlation matrix for 91 stations were carried out using the network science tools and high levels of clustering were revealed. Moving Window Correlation Matrix and Spatio-temporal variography methods were applied to define and explore the dynamic of our data. More than just

  7. Schools, Air Pollution, and Active Transportation: An Exploratory Spatial Analysis of Calgary, Canada.

    Science.gov (United States)

    Bertazzon, Stefania; Shahid, Rizwan

    2017-07-25

    An exploratory spatial analysis investigates the location of schools in Calgary (Canada) in relation to air pollution and active transportation options. Air pollution exhibits marked spatial variation throughout the city, along with distinct spatial patterns in summer and winter; however, all school locations lie within low to moderate pollution levels. Conversely, the study shows that almost half of the schools lie in low walkability locations; likewise, transitability is low for 60% of schools, and only bikability is widespread, with 93% of schools in very bikable locations. School locations are subsequently categorized by pollution exposure and active transportation options. This analysis identifies and maps schools according to two levels of concern: schools in car-dependent locations and relatively high pollution; and schools in locations conducive of active transportation, yet exposed to relatively high pollution. The findings can be mapped and effectively communicated to the public, health practitioners, and school boards. The study contributes with an explicitly spatial approach to the intra-urban public health literature. Developed for a moderately polluted city, the methods can be extended to more severely polluted environments, to assist in developing spatial public health policies to improve respiratory outcomes, neurodevelopment, and metabolic and attention disorders in school-aged children.

  8. Exploratory spatial data analysis for the identification of risk factors to birth defects

    Directory of Open Access Journals (Sweden)

    Song Xinming

    2004-06-01

    Full Text Available Abstract Background Birth defects, which are the major cause of infant mortality and a leading cause of disability, refer to "Any anomaly, functional or structural, that presents in infancy or later in life and is caused by events preceding birth, whether inherited, or acquired (ICBDMS". However, the risk factors associated with heredity and/or environment are very difficult to filter out accurately. This study selected an area with the highest ratio of neural-tube birth defect (NTBD occurrences worldwide to identify the scale of environmental risk factors for birth defects using exploratory spatial data analysis methods. Methods By birth defect registers based on hospital records and investigation in villages, the number of birth defects cases within a four-year period was acquired and classified by organ system. The neural-tube birth defect ratio was calculated according to the number of births planned for each village in the study area, as the family planning policy is strictly adhered to in China. The Bayesian modeling method was used to estimate the ratio in order to remove the dependence of variance caused by different populations in each village. A recently developed statistical spatial method for detecting hotspots, Getis's 7, was used to detect the high-risk regions for neural-tube birth defects in the study area. Results After the Bayesian modeling method was used to calculate the ratio of neural-tube birth defects occurrences, Getis's statistics method was used in different distance scales. Two typical clustering phenomena were present in the study area. One was related to socioeconomic activities, and the other was related to soil type distributions. Conclusion The fact that there were two typical hotspot clustering phenomena provides evidence that the risk for neural-tube birth defect exists on two different scales (a socioeconomic scale at 6.84 km and a soil type scale at 22.8 km for the area studied. Although our study has limited

  9. Exploratory spatial analysis of pilot fatality rates in general aviation crashes using geographic information systems.

    Science.gov (United States)

    Grabowski, Jurek G; Curriero, Frank C; Baker, Susan P; Li, Guohua

    2002-03-01

    Geographic information systems and exploratory spatial analysis were used to describe the geographic characteristics of pilot fatality rates in 1983-1998 general aviation crashes within the continental United States. The authors plotted crash sites on a digital map; rates were computed at regular grid intersections and then interpolated by using geographic information systems. A test for significance was performed by using Monte Carlo simulations. Further analysis compared low-, medium-, and high-rate areas in relation to pilot characteristics, aircraft type, and crash circumstance. Of the 14,051 general aviation crashes studied, 31% were fatal. Seventy-four geographic areas were categorized as having low fatality rates and 53 as having high fatality rates. High-fatality-rate areas tended to be mountainous, such as the Rocky Mountains and the Appalachian region, whereas low-rate areas were relatively flat, such as the Great Plains. Further analysis comparing low-, medium-, and high-fatality-rate areas revealed that crashes in high-fatality-rate areas were more likely than crashes in other areas to have occurred under instrument meteorologic conditions and to involve aircraft fire. This study demonstrates that geographic information systems are a valuable tool for injury prevention and aviation safety research.

  10. Distribution of regional income and regional funds in Europe 1989-1999: An exploratory spatial data analysis

    NARCIS (Netherlands)

    Dall'erba, S.D.

    2005-01-01

    The efforts of the European Commission to reduce regional inequalities over its territory continue to attract the attention of researchers. The purpose of this paper is to perform an exploratory investigation of the relationship between the spatial distribution of regional income and of regional

  11. Flood risk perceptions and spatial multi-criteria analysis: an exploratory research for hazard mitigation

    NARCIS (Netherlands)

    Raaijmakers, R.; Raaijmakers, Ruud; Krywkow, Jorg; van der Veen, A.

    2008-01-01

    The conventional method of risk analysis (with risk as a product of probability and consequences) does not allow for a pluralistic approach that includes the various risk perceptions of stakeholders or lay people within a given social system. This article introduces a methodology that combines the

  12. Bayesian Exploratory Factor Analysis

    DEFF Research Database (Denmark)

    Conti, Gabriella; Frühwirth-Schnatter, Sylvia; Heckman, James J.

    2014-01-01

    This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor, and the corr......This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor......, and the corresponding factor loadings. Classical identification criteria are applied and integrated into our Bayesian procedure to generate models that are stable and clearly interpretable. A Monte Carlo study confirms the validity of the approach. The method is used to produce interpretable low dimensional aggregates...

  13. Sparse Exploratory Factor Analysis.

    Science.gov (United States)

    Trendafilov, Nickolay T; Fontanella, Sara; Adachi, Kohei

    2017-07-13

    Sparse principal component analysis is a very active research area in the last decade. It produces component loadings with many zero entries which facilitates their interpretation and helps avoid redundant variables. The classic factor analysis is another popular dimension reduction technique which shares similar interpretation problems and could greatly benefit from sparse solutions. Unfortunately, there are very few works considering sparse versions of the classic factor analysis. Our goal is to contribute further in this direction. We revisit the most popular procedures for exploratory factor analysis, maximum likelihood and least squares. Sparse factor loadings are obtained for them by, first, adopting a special reparameterization and, second, by introducing additional [Formula: see text]-norm penalties into the standard factor analysis problems. As a result, we propose sparse versions of the major factor analysis procedures. We illustrate the developed algorithms on well-known psychometric problems. Our sparse solutions are critically compared to ones obtained by other existing methods.

  14. Bayesian Exploratory Factor Analysis

    Science.gov (United States)

    Conti, Gabriella; Frühwirth-Schnatter, Sylvia; Heckman, James J.; Piatek, Rémi

    2014-01-01

    This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor, and the corresponding factor loadings. Classical identification criteria are applied and integrated into our Bayesian procedure to generate models that are stable and clearly interpretable. A Monte Carlo study confirms the validity of the approach. The method is used to produce interpretable low dimensional aggregates from a high dimensional set of psychological measurements. PMID:25431517

  15. Exploratory Bi-Factor Analysis

    Science.gov (United States)

    Jennrich, Robert I.; Bentler, Peter M.

    2011-01-01

    Bi-factor analysis is a form of confirmatory factor analysis originally introduced by Holzinger. The bi-factor model has a general factor and a number of group factors. The purpose of this article is to introduce an exploratory form of bi-factor analysis. An advantage of using exploratory bi-factor analysis is that one need not provide a specific…

  16. Exploratory orbit analysis

    International Nuclear Information System (INIS)

    Michelotti, L.

    1989-03-01

    Unlike the other documents in these proceedings, this paper is neither a scientific nor a technical report. It is, rather, a short personal essay which attempts to describe an Exploratory Orbit Analysis (EOA) environment. Analyzing the behavior of a four or six dimensional nonlinear dynamical system is at least as difficult as analyzing events in high-energy collisions; the consequences of doing it badly, or slowly, would be at least as devastating; and yet the level of effort and expenditure invested in the latter, the very attention paid to it by physicists at large, must be two orders of magnitude greater than that given to the former. It is difficult to choose the model which best explains the behavior of a physical device if one does not first understand the behavior of the available models. The time is ripe for the development of a functioning EOA environment, which I will try to describe in this paper to help us achieve this goal

  17. Monitoring county-level chlamydia incidence in Texas, 2004 – 2005: application of empirical Bayesian smoothing and Exploratory Spatial Data Analysis (ESDA methods

    Directory of Open Access Journals (Sweden)

    Owens Chantelle J

    2009-02-01

    Full Text Available Abstract Background Chlamydia continues to be the most prevalent disease in the United States. Effective spatial monitoring of chlamydia incidence is important for successful implementation of control and prevention programs. The objective of this study is to apply Bayesian smoothing and exploratory spatial data analysis (ESDA methods to monitor Texas county-level chlamydia incidence rates by examining spatiotemporal patterns. We used county-level data on chlamydia incidence (for all ages, gender and races from the National Electronic Telecommunications System for Surveillance (NETSS for 2004 and 2005. Results Bayesian-smoothed chlamydia incidence rates were spatially dependent both in levels and in relative changes. Erath county had significantly (p 300 cases per 100,000 residents than its contiguous neighbors (195 or less in both years. Gaines county experienced the highest relative increase in smoothed rates (173% – 139 to 379. The relative change in smoothed chlamydia rates in Newton county was significantly (p Conclusion Bayesian smoothing and ESDA methods can assist programs in using chlamydia surveillance data to identify outliers, as well as relevant changes in chlamydia incidence in specific geographic units. Secondly, it may also indirectly help in assessing existing differences and changes in chlamydia surveillance systems over time.

  18. Exploratory Analysis in Learning Analytics

    Science.gov (United States)

    Gibson, David; de Freitas, Sara

    2016-01-01

    This article summarizes the methods, observations, challenges and implications for exploratory analysis drawn from two learning analytics research projects. The cases include an analysis of a games-based virtual performance assessment and an analysis of data from 52,000 students over a 5-year period at a large Australian university. The complex…

  19. Exploratory and spatial data analysis (EDA-SDA) for determining regional background levels and anomalies of potentially toxic elements in soils from Catorce-Matehuala, Mexico

    Science.gov (United States)

    Chiprés, J.A.; Castro-Larragoitia, J.; Monroy, M.G.

    2009-01-01

    The threshold between geochemical background and anomalies can be influenced by the methodology selected for its estimation. Environmental evaluations, particularly those conducted in mineralized areas, must consider this when trying to determinate the natural geochemical status of a study area, quantifying human impacts, or establishing soil restoration values for contaminated sites. Some methods in environmental geochemistry incorporate the premise that anomalies (natural or anthropogenic) and background data are characterized by their own probabilistic distributions. One of these methods uses exploratory data analysis (EDA) on regional geochemical data sets coupled with a geographic information system (GIS) to spatially understand the processes that influence the geochemical landscape in a technique that can be called a spatial data analysis (SDA). This EDA-SDA methodology was used to establish the regional background range from the area of Catorce-Matehuala in north-central Mexico. Probability plots of the data, particularly for those areas affected by human activities, show that the regional geochemical background population is composed of smaller subpopulations associated with factors such as soil type and parent material. This paper demonstrates that the EDA-SDA method offers more certainty in defining thresholds between geochemical background and anomaly than a numeric technique, making it a useful tool for regional geochemical landscape analysis and environmental geochemistry studies.

  20. Exploratory data analysis with Matlab

    CERN Document Server

    Martinez, Wendy L; Solka, Jeffrey

    2004-01-01

    Exploratory data analysis (EDA) was conceived at a time when computers were not widely used, and thus computational ability was rather limited. As computational sophistication has increased, EDA has become an even more powerful process for visualizing and summarizing data before making model assumptions to generate hypotheses, encompassing larger and more complex data sets. There are many resources for those interested in the theory of EDA, but this is the first book to use MATLAB to illustrate the computational aspects of this discipline.Exploratory Data Analysis with MATLAB presents the meth

  1. Wildland fire risk and social vulnerability in the Southeastern United States: An exploratory spatial data analysis approach

    Science.gov (United States)

    Cassandra Johnson Gaither; N.C. Poudyal; S. Goodrick; J.M. Bowker; S. Malone; J. Gan

    2011-01-01

    The southeastern U.S. is one of the more wildland fire prone areas of the country and also contains some of the poorest or most socially vulnerable rural communities. Our project addresses wildland fire risk in this part of the U.S and its intersection with social vulnerability. We examine spatial association between high wildland fire prone areas which also rank high...

  2. Spread of porcine circovirus associated disease (PCVAD in Ontario (Canada swine herds: Part I. Exploratory spatial analysis

    Directory of Open Access Journals (Sweden)

    Young Beth

    2010-12-01

    Full Text Available Abstract Background The systemic form of porcine circovirus associated disease (PCVAD, also known as postweaning multisystemic wasting syndrome (PMWS was initially detected in the early 1990s. Starting in 2004, the Canadian swine industry experienced considerable losses due to PCVAD, concurrent with a shift in genotype of porcine circovirus type 2 (PCV2. Objectives of the current study were to explore spatial characteristics of self-reported PCVAD distribution in Ontario between 2004 and 2008, and to investigate the existence and nature of local spread. Results The study included 278 swine herds from a large disease-monitoring project that included porcine reproductive and respiratory syndrome (PRRS virus-positive herds identified by the diagnostic laboratory, and PRRS virus-negative herds directly from the target population. Herds were included if they had growing pigs present on-site and available geographical coordinates for the sampling site. Furthermore, herds were defined as PCVAD-positive if a producer reported an outbreak of circovirus associated disease, or as PCVAD-negative if no outbreak was noted. Spatial trend was investigated using generalized additive models and time to PCVAD outbreak in a herd using Cox's proportional hazard model; spatial and spatio-temporal clustering was explored using K-functions; and location of most likely spatial and spatio-temporal clusters was investigated using scan statistics. Over the study period, the risk of reporting a PCVAD-positive herd tended to be higher in the eastern part of the province after adjustment for herd PRRS status (P = 0.05. This was partly confirmed for spread (Partial P P = 0.06 existence of spatio-temporal clustering of PCVAD and detection of a spatio-temporal cluster (P = 0.04. Conclusions In Ontario, PCVAD has shown a general trend, spreading from east-to-west. We interpret the existence of spatio-temporal clustering as evidence of spatio-temporal aggregation of PCVAD

  3. Videogames and Spatial Skills: An Exploratory Study.

    Science.gov (United States)

    Gagnon, Diana

    1985-01-01

    This study of undergraduate and graduate students examined the potential relationship between spatial aptitude and videogame use to: (1) determine relationship between scoring ability on videogames and spatial aptitude as defined by standardized tests; (2) explore potential gender differences; and (3) examine effects of videogames practice on…

  4. Sentiment Analysis for Exploratory Data Analysis

    Directory of Open Access Journals (Sweden)

    Zoë Wilkinson Saldaña

    2018-01-01

    Full Text Available In this lesson you will learn to conduct 'sentiment analysis' on texts and to interpret the results. This is a form of exploratory data analysis based on natural language processing. You will learn to install all appropriate software and to build a reusable program that can be applied to your own texts.

  5. Análisis exploratorio espacial de los accidentes de tránsito en Ciudad Juárez, México Spatial exploratory analysis of road accidents in Ciudad Juarez, Mexico

    Directory of Open Access Journals (Sweden)

    Vladimir Hernández Hernández

    2012-05-01

    located in areas with a high level of urbanization, low population density, and a high transit flow level. CONCLUSIONS: The exploratory analysis of spatial data is a phase that precedes the use of multivariate techniques with a broader scope. The application of exploratory analysis techniques in itself makes it possible to standardize spatial groupings, identify global autocorrelation, and indicate the direction of the variables under study.

  6. Exploratory multivariate analysis by example using R

    CERN Document Server

    Husson, Francois; Pages, Jerome

    2010-01-01

    Full of real-world case studies and practical advice, Exploratory Multivariate Analysis by Example Using R focuses on four fundamental methods of multivariate exploratory data analysis that are most suitable for applications. It covers principal component analysis (PCA) when variables are quantitative, correspondence analysis (CA) and multiple correspondence analysis (MCA) when variables are categorical, and hierarchical cluster analysis.The authors take a geometric point of view that provides a unified vision for exploring multivariate data tables. Within this framework, they present the prin

  7. Sociometric Indicators of Leadership: An Exploratory Analysis

    Science.gov (United States)

    2018-01-01

    as climate antecedents: A social network analysis . Journal of Applied Psychology, 93, 744- 754. ...Research Report 2015 Sociometric Indicators of Leadership: An Exploratory Analysis Elizabeth R. Uhl U.S. Army... Behavioral and Social Sciences Approved for public release; distribution is unlimited. U.S. Army Research Institute for the Behavioral and Social

  8. The Infinitesimal Jackknife with Exploratory Factor Analysis

    Science.gov (United States)

    Zhang, Guangjian; Preacher, Kristopher J.; Jennrich, Robert I.

    2012-01-01

    The infinitesimal jackknife, a nonparametric method for estimating standard errors, has been used to obtain standard error estimates in covariance structure analysis. In this article, we adapt it for obtaining standard errors for rotated factor loadings and factor correlations in exploratory factor analysis with sample correlation matrices. Both…

  9. What Is Rotating in Exploratory Factor Analysis?

    Science.gov (United States)

    Osborne, Jason W.

    2015-01-01

    Exploratory factor analysis (EFA) is one of the most commonly-reported quantitative methodology in the social sciences, yet much of the detail regarding what happens during an EFA remains unclear. The goal of this brief technical note is to explore what "rotation" is, what exactly is rotating, and why we use rotation when performing…

  10. Fundamentals of exploratory analysis of variance

    CERN Document Server

    Hoaglin, David C; Tukey, John W

    2009-01-01

    The analysis of variance is presented as an exploratory component of data analysis, while retaining the customary least squares fitting methods. Balanced data layouts are used to reveal key ideas and techniques for exploration. The approach emphasizes both the individual observations and the separate parts that the analysis produces. Most chapters include exercises and the appendices give selected percentage points of the Gaussian, t, F chi-squared and studentized range distributions.

  11. CADDIS Volume 4. Data Analysis: Exploratory Data Analysis

    Science.gov (United States)

    Intro to exploratory data analysis. Overview of variable distributions, scatter plots, correlation analysis, GIS datasets. Use of conditional probability to examine stressor levels and impairment. Exploring correlations among multiple stressors.

  12. Mapping mHealth (mobile health) and mobile penetrations in sub-Saharan Africa for strategic regional collaboration in mHealth scale-up: an application of exploratory spatial data analysis.

    Science.gov (United States)

    Lee, Seohyun; Cho, Yoon-Min; Kim, Sun-Young

    2017-08-22

    Mobile health (mHealth), a term used for healthcare delivery via mobile devices, has gained attention as an innovative technology for better access to healthcare and support for performance of health workers in the global health context. Despite large expansion of mHealth across sub-Saharan Africa, regional collaboration for scale-up has not made progress since last decade. As a groundwork for strategic planning for regional collaboration, the study attempted to identify spatial patterns of mHealth implementation in sub-Saharan Africa using an exploratory spatial data analysis. In order to obtain comprehensive data on the total number of mHelath programs implemented between 2006 and 2016 in each of the 48 sub-Saharan Africa countries, we performed a systematic data collection from various sources, including: the WHO eHealth Database, the World Bank Projects & Operations Database, and the USAID mHealth Database. Additional spatial analysis was performed for mobile cellular subscriptions per 100 people to suggest strategic regional collaboration for improving mobile penetration rates along with the mHealth initiative. Global Moran's I and Local Indicator of Spatial Association (LISA) were calculated for mHealth programs and mobile subscriptions per 100 population to investigate spatial autocorrelation, which indicates the presence of local clustering and spatial disparities. From our systematic data collection, the total number of mHealth programs implemented in sub-Saharan Africa between 2006 and 2016 was 487 (same programs implemented in multiple countries were counted separately). Of these, the eastern region with 17 countries and the western region with 16 countries had 287 and 145 mHealth programs, respectively. Despite low levels of global autocorrelation, LISA enabled us to detect meaningful local clusters. Overall, the eastern part of sub-Saharan Africa shows high-high association for mHealth programs. As for mobile subscription rates per 100 population, the

  13. Differential effects of aging on spatial learning through exploratory navigation and map reading.

    Science.gov (United States)

    Yamamoto, Naohide; Degirolamo, Gregory J

    2012-01-01

    It has been shown that abilities in spatial learning and memory are adversely affected by aging. The present study was conducted to investigate whether increasing age has equal consequences for all types of spatial learning or impacts certain types of spatial learning selectively. Specifically, two major types of spatial learning, exploratory navigation and map reading, were contrasted. By combining a neuroimaging finding that the medial temporal lobe (MTL) is especially important for exploratory navigation and a neurological finding that the MTL is susceptible to age-related atrophy, it was hypothesized that spatial learning through exploratory navigation would exhibit a greater decline in later life than spatial learning through map reading. In an experiment, young and senior participants learned locations of landmarks in virtual environments either by navigating in them in the first-person perspective or by seeing aerial views of the environments. Results showed that senior participants acquired less accurate memories of the layouts of landmarks than young participants when they navigated in the environments, but the two groups did not differ in spatial learning performance when they viewed the environments from the aerial perspective. These results suggest that spatial learning through exploratory navigation is particularly vulnerable to adverse effects of aging, whereas elderly adults may be able to maintain their map reading skills relatively well.

  14. A Review of CEFA Software: Comprehensive Exploratory Factor Analysis Program

    Science.gov (United States)

    Lee, Soon-Mook

    2010-01-01

    CEFA 3.02(Browne, Cudeck, Tateneni, & Mels, 2008) is a factor analysis computer program designed to perform exploratory factor analysis. It provides the main properties that are needed for exploratory factor analysis, namely a variety of factoring methods employing eight different discrepancy functions to be minimized to yield initial…

  15. Spatial Data Analysis.

    Science.gov (United States)

    Banerjee, Sudipto

    2016-01-01

    With increasing accessibility to geographic information systems (GIS) software, statisticians and data analysts routinely encounter scientific data sets with geocoded locations. This has generated considerable interest in statistical modeling for location-referenced spatial data. In public health, spatial data routinely arise as aggregates over regions, such as counts or rates over counties, census tracts, or some other administrative delineation. Such data are often referred to as areal data. This review article provides a brief overview of statistical models that account for spatial dependence in areal data. It does so in the context of two applications: disease mapping and spatial survival analysis. Disease maps are used to highlight geographic areas with high and low prevalence, incidence, or mortality rates of a specific disease and the variability of such rates over a spatial domain. They can also be used to detect hot spots or spatial clusters that may arise owing to common environmental, demographic, or cultural effects shared by neighboring regions. Spatial survival analysis refers to the modeling and analysis for geographically referenced time-to-event data, where a subject is followed up to an event (e.g., death or onset of a disease) or is censored, whichever comes first. Spatial survival analysis is used to analyze clustered survival data when the clustering arises from geographical regions or strata. Illustrations are provided in these application domains.

  16. Key Words and the Analysis of Exploratory Talk

    Science.gov (United States)

    Herrlitz-Biró, Linda; Elbers, Ed; de Haan, Mariëtte

    2013-01-01

    The count of key words indicating the quality of reasoning has been used as a method to observe exploratory talk. However, reasoning in talk does not necessarily contain key words. The analysis of key words leaves unattended other aspects of exploratory talk, such as collaborative processes. The question is: to what extent can the analysis of key…

  17. Exploratory Studies Facility Subsurface Fire Hazards Analysis

    International Nuclear Information System (INIS)

    Kubicek, J. L.

    2001-01-01

    The primary objective of this Fire Hazard Analysis (FHA) is to confirm the requirements for a comprehensive fire and related hazards protection program for the Exploratory Studies Facility (ESF) are sufficient to minimize the potential for: (1) The occurrence of a fire or related event. (2) A fire that causes an unacceptable on-site or off-site release of hazardous or radiological material that will threaten the health and safety of employees, the public or the environment. (3) Vital US. Department of Energy (DOE) programs suffering unacceptable interruptions as a result of fire and related hazards. (4) Property losses from a fire and related events exceeding limits established by DOE. (5) Critical process controls and safety class systems being damaged as a result of a fire and related events

  18. Exploratory Studies Facility Subsurface Fire Hazards Analysis

    International Nuclear Information System (INIS)

    Logan, Richard C.

    2002-01-01

    The primary objective of this Fire Hazard Analysis (FHA) is to confirm the requirements for a comprehensive fire and related hazards protection program for the Exploratory Studies Facility (ESF) are sufficient to minimize the potential for: The occurrence of a fire or related event; A fire that causes an unacceptable on-site or off-site release of hazardous or radiological material that will threaten the health and safety of employees, the public or the environment; Vital U.S. Department of Energy (DOE) programs suffering unacceptable interruptions as a result of fire and related hazards; Property losses from a fire and related events exceeding limits established by DOE; and Critical process controls and safety class systems being damaged as a result of a fire and related events

  19. Current exploratory and confirmatory issues in data analysis in psychology

    OpenAIRE

    Marmolejo-Ramos, Fernando; University of Adelaide - Universidad del Valle

    2015-01-01

    In 1968 John Tukey gave a speech at the American Psychological Association in San Francisco about the relevance of proper data analysis in Psychology (Tukey, 1969). His closing message was that “data analysis needs to be both exploratory and confirmatory” (p. 90). Exploratory data analysis (or EDA) is an approach to analysing data in order to formulate sound hypotheses, whereas confirmatory data analysis (CDA) is a method to test those hypotheses (a.k.a., statistical hypothesis testing). As T...

  20. Factors affecting construction performance: exploratory factor analysis

    Science.gov (United States)

    Soewin, E.; Chinda, T.

    2018-04-01

    The present work attempts to develop a multidimensional performance evaluation framework for a construction company by considering all relevant measures of performance. Based on the previous studies, this study hypothesizes nine key factors, with a total of 57 associated items. The hypothesized factors, with their associated items, are then used to develop questionnaire survey to gather data. The exploratory factor analysis (EFA) was applied to the collected data which gave rise 10 factors with 57 items affecting construction performance. The findings further reveal that the items constituting ten key performance factors (KPIs) namely; 1) Time, 2) Cost, 3) Quality, 4) Safety & Health, 5) Internal Stakeholder, 6) External Stakeholder, 7) Client Satisfaction, 8) Financial Performance, 9) Environment, and 10) Information, Technology & Innovation. The analysis helps to develop multi-dimensional performance evaluation framework for an effective measurement of the construction performance. The 10 key performance factors can be broadly categorized into economic aspect, social aspect, environmental aspect, and technology aspects. It is important to understand a multi-dimension performance evaluation framework by including all key factors affecting the construction performance of a company, so that the management level can effectively plan to implement an effective performance development plan to match with the mission and vision of the company.

  1. Exploratory, anxiety and spatial memory impairments are dissociated in mice lacking the LPA1 receptor

    Science.gov (United States)

    Castilla-Ortega, Estela; Sánchez-López, Jorge; Hoyo-Becerra, Carolina; Matas-Rico, Elisa; Zambrana-Infantes, Emma; Chun, Jerold; Fonseca, Fernando Rodríguez De; Pedraza, Carmen; Estivill-Torrús, Guillermo; Santin, Luis J.

    2013-01-01

    Lysophosphatidic acid (LPA) is a new, intercellular signalling molecule in the brain that has an important role in adult hippocampal plasticity. Mice lacking the LPA1 receptor exhibit motor, emotional and cognitive alterations. However, the potential relationship among these concomitant impairments was unclear. Wild-type and maLPA1-null mice were tested on the hole-board for habituation and spatial learning. MaLPA1-null mice exhibited reduced exploration in a novel context and a defective intersession habituation that also revealed increased anxiety-like behaviour throughout the hole-board testing. In regard to spatial memory, maLPA1 nulls failed to reach the controls’ performance at the end of the reference memory task. Moreover, their defective working memory on the first training day suggested a delayed acquisition of the task’s working memory rule, which is also a long term memory component. The temporal interval between trials and the task’s difficulty may explain some of the deficits found in these mice. Principal components analysis revealed that alterations found in each behavioural dimension were independent. Therefore, exploratory and emotional impairments did not account for the cognitive deficits that may be attributed to maLPA1 nulls’ hippocampal malfunction. PMID:20388543

  2. Psychobiological Correlates of Vaginismus: An Exploratory Analysis.

    Science.gov (United States)

    Maseroli, Elisa; Scavello, Irene; Cipriani, Sarah; Palma, Manuela; Fambrini, Massimiliano; Corona, Giovanni; Mannucci, Edoardo; Maggi, Mario; Vignozzi, Linda

    2017-11-01

    Evidence concerning the determinants of vaginismus (V), in particular medical conditions, is inconclusive. To investigate, in a cohort of subjects consulting for female sexual dysfunction, whether there is a difference in medical and psychosocial parameters between women with V and women with other sexual complaints. A series of 255 women attending our clinic for female sexual dysfunction was consecutively recruited. V was diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria. Lifelong and acquired V cases were included. Patients underwent a structured interview and physical, gynecologic, laboratory, and clitoral ultrasound examinations; they completed the Female Sexual Function Index (FSFI), the Middlesex Hospital Questionnaire, the Female Sexual Distress Scale-Revised (FSDS), and the Body Uneasiness Test. V was diagnosed in 20 patients (7.8%). Women with V were significantly younger than the rest of the sample (P pain and FSDS total scores, even after adjusting for age (P pain domain, and sex-related distress. A history of abuse, relational parameters, gynecologic diseases, and hormonal and metabolic alterations do not seem to play a role in the development of V. Maseroli E, Scavello I, Cipriani S, et al. Psychobiological Correlates of Vaginismus: An Exploratory Analysis. J Sex Med 2017;14:1392-1402. Copyright © 2017 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  3. EXPLORATORY FACTOR ANALYSIS (EFA IN CONSUMER BEHAVIOR AND MARKETING RESEARCH

    Directory of Open Access Journals (Sweden)

    Marcos Pascual Soler

    2012-06-01

    Full Text Available Exploratory Factor Analysis (EFA is one of the most widely used statistical procedures in social research. The main objective of this work is to describe the most common practices used by researchers in the consumer behavior and marketing area. Through a literature review methodology the practices of AFE in five consumer behavior and marketing journals(2000-2010 were analyzed. Then, the choices made by the researchers concerning factor model, retention criteria, rotation, factors interpretation and other relevant issues to factor analysis were analized. The results suggest that researchers routinely conduct analyses using such questionable methods. Suggestions for improving the use of factor analysis and the reporting of results are presented and a checklist (Exploratory Factor Analysis Checklist, EFAC is provided to help editors, reviewers, and authors improve reporting exploratory factor analysis.

  4. Exploratory factor analysis in Rehabilitation Psychology: a content analysis.

    Science.gov (United States)

    Roberson, Richard B; Elliott, Timothy R; Chang, Jessica E; Hill, Jessica N

    2014-11-01

    Our objective was to examine the use and quality of exploratory factor analysis (EFA) in articles published in Rehabilitation Psychology. Trained raters examined 66 separate exploratory factor analyses in 47 articles published between 1999 and April 2014. The raters recorded the aim of the EFAs, the distributional statistics, sample size, factor retention method(s), extraction and rotation method(s), and whether the pattern coefficients, structure coefficients, and the matrix of association were reported. The primary use of the EFAs was scale development, but the most widely used extraction and rotation method was principle component analysis, with varimax rotation. When determining how many factors to retain, multiple methods (e.g., scree plot, parallel analysis) were used most often. Many articles did not report enough information to allow for the duplication of their results. EFA relies on authors' choices (e.g., factor retention rules extraction, rotation methods), and few articles adhered to all of the best practices. The current findings are compared to other empirical investigations into the use of EFA in published research. Recommendations for improving EFA reporting practices in rehabilitation psychology research are provided.

  5. The Measurand Framework: Scaling Exploratory Data Analysis

    Science.gov (United States)

    Schneider, D.; MacLean, L. S.; Kappler, K. N.; Bleier, T.

    2017-12-01

    Since 2005 QuakeFinder (QF) has acquired a unique dataset with outstanding spatial and temporal sampling of earth's time varying magnetic field along several active fault systems. This QF network consists of 124 stations in California and 45 stations along fault zones in Greece, Taiwan, Peru, Chile and Indonesia. Each station is equipped with three feedback induction magnetometers, two ion sensors, a 4 Hz geophone, a temperature sensor, and a humidity sensor. Data are continuously recorded at 50 Hz with GPS timing and transmitted daily to the QF data center in California for analysis. QF is attempting to detect and characterize anomalous EM activity occurring ahead of earthquakes. In order to analyze this sizable dataset, QF has developed an analytical framework to support processing the time series input data and hypothesis testing to evaluate the statistical significance of potential precursory signals. The framework was developed with a need to support legacy, in-house processing but with an eye towards big-data processing with Apache Spark and other modern big data technologies. In this presentation, we describe our framework, which supports rapid experimentation and iteration of candidate signal processing techniques via modular data transformation stages, tracking of provenance, and automatic re-computation of downstream data when upstream data is updated. Furthermore, we discuss how the processing modules can be ported to big data platforms like Apache Spark and demonstrate a migration path from local, in-house processing to cloud-friendly processing.

  6. Exploratory Bi-Factor Analysis: The Oblique Case

    Science.gov (United States)

    Jennrich, Robert I.; Bentler, Peter M.

    2012-01-01

    Bi-factor analysis is a form of confirmatory factor analysis originally introduced by Holzinger and Swineford ("Psychometrika" 47:41-54, 1937). The bi-factor model has a general factor, a number of group factors, and an explicit bi-factor structure. Jennrich and Bentler ("Psychometrika" 76:537-549, 2011) introduced an exploratory form of bi-factor…

  7. Professional analysis in spatial planning

    Directory of Open Access Journals (Sweden)

    Andrej Černe

    2005-12-01

    Full Text Available Spatial analysis contributes to accomplishment of the three basic aims of spatial planning: it is basic element for setting spatial policies, concepts and strategies, gives basic information to inhabitants, land owners, investors, planners and helps in performing spatial policies, strategies, plans, programmes and projects. Analysis in planning are generally devoted to: understand current circumstances and emerging conditions within planning decisions; determine priorities of open questions and their solutions; formulate general principles for further development.

  8. Exploratory principal components analysis of growth traits in Red ...

    African Journals Online (AJOL)

    Exploratory principal components analysis of growth traits in Red Sokoto goats. ... Similar prediction pattern is obtained for CWT. ... similarity of intercepts of regression equations and those of average values for growth traits in this study indicated the possibility of improvement of goat stocks through the principal components.

  9. Likelihood-Based Confidence Intervals in Exploratory Factor Analysis

    NARCIS (Netherlands)

    Oort, Frans J.

    2011-01-01

    In exploratory or unrestricted factor analysis, all factor loadings are free to be estimated. In oblique solutions, the correlations between common factors are free to be estimated as well. The purpose of this article is to show how likelihood-based confidence intervals can be obtained for rotated

  10. Likelihood-based confidence intervals in exploratory factor analysis

    NARCIS (Netherlands)

    Oort, F.J.

    2011-01-01

    In exploratory or unrestricted factor analysis, all factor loadings are free to be estimated. In oblique solutions, the correlations between common factors are free to be estimated as well. The purpose of this article is to show how likelihood-based confidence intervals can be obtained for rotated

  11. Likelihood-Based Confidence Intervals in Exploratory Factor Analysis

    Science.gov (United States)

    Oort, Frans J.

    2011-01-01

    In exploratory or unrestricted factor analysis, all factor loadings are free to be estimated. In oblique solutions, the correlations between common factors are free to be estimated as well. The purpose of this article is to show how likelihood-based confidence intervals can be obtained for rotated factor loadings and factor correlations, by…

  12. Establishing Evidence for Internal Structure Using Exploratory Factor Analysis

    Science.gov (United States)

    Watson, Joshua C.

    2017-01-01

    Exploratory factor analysis (EFA) is a data reduction technique used to condense data into smaller sets of summary variables by identifying underlying factors potentially accounting for patterns of collinearity among said variables. Using an illustrative example, the 5 general steps of EFA are described with best practices for decision making…

  13. Progesterone regulates corticosterone elevation and alterations in spatial memory and exploratory behavior induced by stress in Wistar rats

    Directory of Open Access Journals (Sweden)

    Yolanda Diaz-Burke

    2010-02-01

    Full Text Available The hippocampus is sensitive to high levels of glucocorticoids during stress responses; it suffers biochemical and cellular changes that affect spatial memory and exploratory behavior, among others. We analyzed the influence of the neurosteroid progesterone (PROG on stress-induced changes in urinary corticosterone (CORT levels, spatial memory and exploratory behavior.Castrated adult male rats were implanted with PROG or vehicle (VEHI,and then exposed for ten days to chronic stress created by overcrowding or ultrasonic noise. PROG and CORT levels were assessed in urine using highperformanceliquid chromatography (HPLC. Implanted PROG inhibited the rise of stress-induced CORT, prevented spatial memory impairment in the Morris water maze, and eliminated increased exploratory behavior in the hole-board test. These results suggest a protective role of PROG, possibly mediated by its anxiolytic mechanisms, against corticosteroids elevation and the behavioral deficit generated by stressful situations.

  14. Presentation : Spatial Analysis and GEOmatics

    Directory of Open Access Journals (Sweden)

    Didier Josselin

    2006-10-01

    Full Text Available SAGEO is the annual International Conference on Spatial Analysis and GEOmatics. It aims to:  present recent and high quality research in the field of Geomatics and Spatial Analysis, bring together researchers from various disciplines, provide an exchange platform on research and development in Geomatics, on a national and international level, for public or private bodies. SAGEO is a good opportunity for two complementary research networks to meet and to discuss their points of view on spatial...

  15. Perspectives on spatial data analysis

    CERN Document Server

    Rey, Sergio

    2010-01-01

    This book takes both a retrospective and prospective view of the field of spatial analysis by combining selected reprints of classic articles by Arthur Getis with current observations by leading experts in the field. Four main aspects are highlighted, dealing with spatial analysis, pattern analysis, local statistics as well as illustrative empirical applications. Researchers and students will gain an appreciation of Getis' methodological contributions to spatial analysis and the broad impact of the methods he has helped pioneer on an impressively broad array of disciplines including spatial epidemiology, demography, economics, and ecology. The volume is a compilation of high impact original contributions, as evidenced by citations, and the latest thinking on the field by leading scholars. This makes the book ideal for advanced seminars and courses in spatial analysis as well as a key resource for researchers seeking a comprehensive overview of recent advances and future directions in the field.

  16. Exploratory Visual Analysis for Animal Movement Ecology

    NARCIS (Netherlands)

    Slingsby, A.; van Loon, E.

    2016-01-01

    Movement ecologists study animals' movement to help understand their behaviours and interactions with each other and the environment. Data from GPS loggers are increasingly important for this. These data need to be processed, segmented and summarised for further visual and statistical analysis,

  17. A decision analysis of an exploratory studies facility

    International Nuclear Information System (INIS)

    Merkhofer, M.W.; Gnirk, P.

    1991-01-01

    An Exploratory Studies Facility (ESF) is planned to support the characterization of a potential site for a high-level nuclear waste repository at Yucca Mountain, NV. The selection of a design for the ESF is a critical decision, because the ESF design may affect the accuracy of characterization testing and subsequent repository design. The assist the design process, a comparative evaluation was conducted to rank 34 alternative relied on techniques from formal decision analysis, including decision trees and multiattribute utility analysis (MUA). The results helped to identify favorable design features and convinced the Department of Energy to adopt the top-ranked option as the preferred ESF design

  18. Modeling and evaluating user behavior in exploratory visual analysis

    Energy Technology Data Exchange (ETDEWEB)

    Reda, Khairi; Johnson, Andrew E.; Papka, Michael E.; Leigh, Jason

    2016-07-25

    Empirical evaluation methods for visualizations have traditionally focused on assessing the outcome of the visual analytic process as opposed to characterizing how that process unfolds. There are only a handful of methods that can be used to systematically study how people use visualizations, making it difficult for researchers to capture and characterize the subtlety of cognitive and interaction behaviors users exhibit during visual analysis. To validate and improve visualization design, however, it is important for researchers to be able to assess and understand how users interact with visualization systems under realistic scenarios. This paper presents a methodology for modeling and evaluating the behavior of users in exploratory visual analysis. We model visual exploration using a Markov chain process comprising transitions between mental, interaction, and computational states. These states and the transitions between them can be deduced from a variety of sources, including verbal transcripts, videos and audio recordings, and log files. This model enables the evaluator to characterize the cognitive and computational processes that are essential to insight acquisition in exploratory visual analysis, and reconstruct the dynamics of interaction between the user and the visualization system. We illustrate this model with two exemplar user studies, and demonstrate the qualitative and quantitative analytical tools it affords.

  19. Exploratory wavelet analysis of dengue seasonal patterns in Colombia.

    Science.gov (United States)

    Fernández-Niño, Julián Alfredo; Cárdenas-Cárdenas, Luz Mery; Hernández-Ávila, Juan Eugenio; Palacio-Mejía, Lina Sofía; Castañeda-Orjuela, Carlos Andrés

    2015-12-04

    Dengue has a seasonal behavior associated with climatic changes, vector cycles, circulating serotypes, and population dynamics. The wavelet analysis makes it possible to separate a very long time series into calendar time and periods. This is the first time this technique is used in an exploratory manner to model the behavior of dengue in Colombia.  To explore the annual seasonal dengue patterns in Colombia and in its five most endemic municipalities for the period 2007 to 2012, and for roughly annual cycles between 1978 and 2013 at the national level.  We made an exploratory wavelet analysis using data from all incident cases of dengue per epidemiological week for the period 2007 to 2012, and per year for 1978 to 2013. We used a first-order autoregressive model as the null hypothesis.  The effect of the 2010 epidemic was evident in both the national time series and the series for the five municipalities. Differences in interannual seasonal patterns were observed among municipalities. In addition, we identified roughly annual cycles of 2 to 5 years since 2004 at a national level.  Wavelet analysis is useful to study a long time series containing changing seasonal patterns, as is the case of dengue in Colombia, and to identify differences among regions. These patterns need to be explored at smaller aggregate levels, and their relationships with different predictive variables need to be investigated.

  20. Circulating Lipids and Acute Pain Sensitization: An Exploratory Analysis.

    Science.gov (United States)

    Starkweather, Angela; Julian, Thomas; Ramesh, Divya; Heineman, Amy; Sturgill, Jamie; Dorsey, Susan G; Lyon, Debra E; Wijesinghe, Dayanjan Shanaka

    In individuals with low back pain, higher lipid levels have been documented and were associated with increased risk for chronic low back pain. The purpose of this research was to identify plasma lipids that discriminate participants with acute low back pain with or without pain sensitization as measured by quantitative sensory testing. This exploratory study was conducted as part of a larger parent randomized controlled trial. A cluster analysis of 30 participants with acute low back pain revealed two clusters: one with signs of peripheral and central sensitivity to mechanical and thermal stimuli and the other with an absence of peripheral and central sensitivity. Lipid levels were extracted from plasma and measured using mass spectroscopy. Triacylglycerol 50:2 was significantly higher in participants with peripheral and central sensitization compared to the nonsensitized cluster. The nonsensitized cluster had significantly higher levels of phosphoglyceride 34:2, plasmenyl phosphocholine 38:1, and phosphatidic acid 28:1 compared to participants with peripheral and central sensitization. Linear discriminant function analysis was conducted using the four statistically significant lipids to test their predictive power to classify those in the sensitization and no-sensitization clusters; the four lipids accurately predicted cluster classification 58% of the time (R = .58, -2 log likelihood = 14.59). The results of this exploratory study suggest a unique lipidomic signature in plasma of patients with acute low back pain based on the presence or absence of pain sensitization. Future work to replicate these preliminary findings is underway.

  1. Exploratory Factor Analysis With Small Samples and Missing Data.

    Science.gov (United States)

    McNeish, Daniel

    2017-01-01

    Exploratory factor analysis (EFA) is an extremely popular method for determining the underlying factor structure for a set of variables. Due to its exploratory nature, EFA is notorious for being conducted with small sample sizes, and recent reviews of psychological research have reported that between 40% and 60% of applied studies have 200 or fewer observations. Recent methodological studies have addressed small size requirements for EFA models; however, these models have only considered complete data, which are the exception rather than the rule in psychology. Furthermore, the extant literature on missing data techniques with small samples is scant, and nearly all existing studies focus on topics that are not of primary interest to EFA models. Therefore, this article presents a simulation to assess the performance of various missing data techniques for EFA models with both small samples and missing data. Results show that deletion methods do not extract the proper number of factors and estimate the factor loadings with severe bias, even when data are missing completely at random. Predictive mean matching is the best method overall when considering extracting the correct number of factors and estimating factor loadings without bias, although 2-stage estimation was a close second.

  2. Progress in spatial analysis methods and applications

    CERN Document Server

    Páez, Antonio; Buliung, Ron N; Dall'erba, Sandy

    2010-01-01

    This book brings together developments in spatial analysis techniques, including spatial statistics, econometrics, and spatial visualization, and applications to fields such as regional studies, transportation and land use, population and health.

  3. Using Horn's Parallel Analysis Method in Exploratory Factor Analysis for Determining the Number of Factors

    Science.gov (United States)

    Çokluk, Ömay; Koçak, Duygu

    2016-01-01

    In this study, the number of factors obtained from parallel analysis, a method used for determining the number of factors in exploratory factor analysis, was compared to that of the factors obtained from eigenvalue and scree plot--two traditional methods for determining the number of factors--in terms of consistency. Parallel analysis is based on…

  4. Atypical myopathy in grazing horses: a first exploratory data analysis.

    Science.gov (United States)

    Votion, Dominique-M; Linden, Annick; Delguste, Catherine; Amory, Hélène; Thiry, Etienne; Engels, Patrick; van Galen, Gaby; Navet, Rachel; Sluse, Francis; Serteyn, Didier; Saegerman, Claude

    2009-04-01

    Over the last decade, atypical myopathy (AM) in grazing horses has emerged in several European countries. An exploratory analysis was conducted to determine horse- and pasture-level indicators or factors associated with AM in Belgium. Belgian cases of AM confirmed by histology (n=57) were compared to their healthy co-grazing horses (n=77) and to pastured horses not involved with AM as controls (n=386). The pastures where confirmed cases were grazing (42 pastures; 38 sites; 44 incidences of AM) were compared with those of the controls (216 pastures; 96 sites; no incidence of AM). Statistically significant (Phorses (young age, inactivity, body condition poor to normal), management practices (permanent pasturing, spreading of manure) and pasture characteristics (humid, sloping pastures, accumulated dead leaves, presence of waterway) may increase the risk of AM. Specific interventions based on these factors might help to reduce the incidence of AM.

  5. Analysis of Twitter usage in an exploratory seminar setting

    Directory of Open Access Journals (Sweden)

    Wolfgang Reinhardt

    2013-03-01

    Full Text Available Despite the massive social and technological changes that have occurred due to the Web in the recent years, university courses often still emphasize time-honored teaching methods with classical learning tools and resources. During these courses students often acquire knowledge that is not up-to-date and detached from problem-based, realistic learning. The use of more recent tools and methods often remains out of student’s grasp. In this article we briefly report on an exploratory seminar setting at two German universities where the use of Social Media for communication and collaboration was firmly embedded in the educational setup. Furthermore, we illustrate the usage of Twitter during the seminar using techniques from Social Network Analysis.

  6. A Beginner’s Guide to Factor Analysis: Focusing on Exploratory Factor Analysis

    Directory of Open Access Journals (Sweden)

    An Gie Yong

    2013-10-01

    Full Text Available The following paper discusses exploratory factor analysis and gives an overview of the statistical technique and how it is used in various research designs and applications. A basic outline of how the technique works and its criteria, including its main assumptions are discussed as well as when it should be used. Mathematical theories are explored to enlighten students on how exploratory factor analysis works, an example of how to run an exploratory factor analysis on SPSS is given, and finally a section on how to write up the results is provided. This will allow readers to develop a better understanding of when to employ factor analysis and how to interpret the tables and graphs in the output.

  7. Stereological analysis of spatial structures

    DEFF Research Database (Denmark)

    Hansen, Linda Vadgård

    The thesis deals with stereological analysis of spatial structures. One area of focus has been to improve the precision of well-known stereological estimators by including information that is available via automatic image analysis. Furthermore, the thesis presents a stochastic model for star......-shaped three-dimensional objects using the radial function. It appears that the model is highly fleksiblel in the sense that it can be used to describe an object with arbitrary irregular surface. Results on the distribution of well-known local stereological volume estimators are provided....

  8. A new eigenfunction spatial analysis describing population genetic structure.

    Science.gov (United States)

    Diniz-Filho, José Alexandre Felizola; Diniz, João Vitor Barnez P L; Rangel, Thiago Fernando; Soares, Thannya Nascimento; Telles, Mariana Pires de Campos; Collevatti, Rosane Garcia; Bini, Luis Mauricio

    2013-12-01

    Several methods of spatial analyses have been proposed to infer the relative importance of evolutionary processes on genetic population structure. Here we show how a new eigenfunction spatial analysis can be used to model spatial patterns in genetic data. Considering a sample of n local populations, the method starts by modeling the response variable (allele frequencies or phenotypic variation) against the eigenvectors sequentially extracted from a geographic distance matrix (n × n). The relationship between the coefficient of determination (R(2)) of the models and the cumulative eigenvalues, which we named the spatial signal-representation (SSR) curve, can be more efficient than Moran's I correlograms in describing different patterns. The SSR curve was also applied to simulated data (under distinct scenarios of population differentiation) and to analyze spatial patterns in alleles from microsatellite data for 25 local populations of Dipteryx alata, a tree species endemic to the Brazilian Cerrado. The SSR curves are consistent with previous phylogeographical patterns of the species, revealing combined effects of isolation-by-distance and range expansion. Our analyses demonstrate that the SSR curve is a useful exploratory tool for describing spatial patterns of genetic variability and for selecting spatial eigenvectors for models aiming to explain spatial responses to environmental variables and landscape features.

  9. explorase: Multivariate Exploratory Analysis and Visualization for Systems Biology

    Directory of Open Access Journals (Sweden)

    Michael Lawrence

    2008-03-01

    Full Text Available The datasets being produced by high-throughput biological experiments, such as microarrays, have forced biologists to turn to sophisticated statistical analysis and visualization tools in order to understand their data. We address the particular need for an open-source exploratory data analysis tool that applies numerical methods in coordination with interactive graphics to the analysis of experimental data. The software package, known as explorase, provides a graphical user interface (GUI on top of the R platform for statistical computing and the GGobi software for multivariate interactive graphics. The GUI is designed for use by biologists, many of whom are unfamiliar with the R language. It displays metadata about experimental design and biological entities in tables that are sortable and filterable. There are menu shortcuts to the analysis methods implemented in R, including graphical interfaces to linear modeling tools. The GUI is linked to data plots in GGobi through a brush tool that simultaneously colors rows in the entity information table and points in the GGobi plots.

  10. An Exploratory Analysis of Educational Management for the Universities

    Directory of Open Access Journals (Sweden)

    Assist. Prof. Dr. Md. Mamun Habib

    2011-08-01

    Full Text Available This exploratory research addresses educational management model for the universities. Its applicability was successfully verified and validated through survey data from leading tertiary educational institutions around the world. The proposed model was developed based on the analysis of literature, past theoretical frameworks, interviews with stakeholders. Model constructs were identified and confirmed by 493 respondents, representing university administrators, faculty and staffs, employers, and graduates. The resulting model was subsequently evaluated for accuracy and validity by multiple linear regression (MLR analysis and the structural equation modeling (SEM technique. The study revealed education development, education assessment, research development, and research assessment as four main activities in educational management. Four aspects of each activity, namely programs establishment, university culture, faculty capabilities, and facilities were investigated at strategic, planning, and operating levels. The conceptual model for the universities provides a novel approach for prospective investors or current university administrators to review and appraise their performance toward fulfillment of ultimate goals, i.e. producing high-caliber graduates and high-impact research outcomes for the betterment of the society. The research model represents two contributions to the society including human resource contribution and research contribution.

  11. Workplace Innovation: Exploratory and Confirmatory Factor Analysis for Construct Validation

    Directory of Open Access Journals (Sweden)

    Wipulanusat Warit

    2017-06-01

    Full Text Available Workplace innovation enables the development and improvement of products, processes and services leading simultaneously to improvement in organisational performance. This study has the purpose of examining the factor structure of workplace innovation. Survey data, extracted from the 2014 APS employee census, comprising 3,125 engineering professionals in the Commonwealth of Australia’s departments were analysed using exploratory factor analysis (EFA and confirmatory factor analysis (CFA. EFA returned a two-factor structure explaining 69.1% of the variance of the construct. CFA revealed that a two-factor structure was indicated as a validated model (GFI = 0.98, AGFI = 0.95, RMSEA = 0.08, RMR = 0.02, IFI = 0.98, NFI = 0.98, CFI = 0.98, and TLI = 0.96. Both factors showed good reliability of the scale (Individual creativity: α = 0.83, CR = 0.86, and AVE = 0.62; Team Innovation: α = 0.82, CR = 0.88, and AVE = 0.61. These results confirm that the two factors extracted for characterising workplace innovation included individual creativity and team innovation.

  12. using gis for spatial exploratory analysis of borehole data

    African Journals Online (AJOL)

    PUBLICATIONS1

    to be an immeasurable tool that could be used in mapping aquifer characteristics that can serve as firsthand information for groundwater ... Journal of Science and Technology, Vol. 36, No. 1 (2016), pp 38-48 38. RESEARCH ..... mind the particular direction with a noticeable trend. A similar study conducted by Chen et al.,.

  13. Exploring leadership styles for innovation: an exploratory factor analysis

    Directory of Open Access Journals (Sweden)

    Wipulanusat Warit

    2017-03-01

    Full Text Available Leadership plays a vital role in building the process, structures, and climate for an organisation to become innovative and to motivate team expectations toward innovations. This study explores the leadership styles that engineers regard as significant for innovation in the public sector. Exploratory factor analysis (EFA was conducted to identify the principal leadership styles influencing innovation in the Australian Public Service (APS, using survey data extracted from the 2014 APS employee census comprising 3 125 engineering professionals in Commonwealth of Australia departments. EFA returned a two-factor structure explaining 77.6% of the variance of the leadership for innovation construct. In this study, the results from the EFA provided a clear estimation of the factor structure of the measures for leadership for innovation. From the results, the two factors extracted were transformational leadership and consideration leadership. In transformational leadership, a leader values organisational objectives, inspires subordinates to perform, and motivates followers beyond expected levels of work standards. Consideration leadership refers to the degree to which a leader shows concern and expressions of support for subordinates, takes care of their welfare, treats members as equals, and displays warmth and approachability. These findings highlight the role of leadership as the most critical predictor when considering the degree to which subordinates strive for creativity and innovation. Both transformational and consideration leadership styles are recommended to be incorporated into management training and development programs. This study also recommends that Commonwealth departments recruit supervisors who have both of these leadership styles before implementing innovative projects.

  14. Assessing emergency nurses' clinical competency: An exploratory factor analysis study

    Directory of Open Access Journals (Sweden)

    Atefeh Ghanbari

    2017-01-01

    Full Text Available Background: Nursing as a clinical discipline is developing in the emergency wards. Health care systems should continuously assess and prioritize indicators of clinical competency in these wards. The lack of clear standards of clinical competency indicators challenges evaluation. The purpose of this study was to determine clinical competency indicators and its priority based on nurses' views in educational and therapeutic centers in Guilan. Materials and Methods: The Q methodology was conducted in three phases, that is, phase I (determining the clinical competency indicators, phase II (classifying clinical competency indicators by an expert panel, and phase III (prioritizing clinical competency indicators. The subjects were selected by convenience sampling among nurses working in the emergency wards of teaching hospitals affiliated to Guilan in 2013. Finally, clinical competency indicators were prioritized using exploratory factor analysis. Results: In the prioritizing phase, data were collected from 710 nurses over two months. Five factors with 30 general competencies were found in three domains: communication, professional maturity, and personality characteristics. Six factors with 37 specific competencies were also found in two domains: scientific and technical capabilities and basic clinical skills that can provide a structured instrument for assessing clinical competence in emergency nurses. Conclusions: Achieved competencies can be used as a reference for nursing education and practice in emergency. Further research on health care system is needed in order to achieve a reliable and valid instrument.

  15. Transition Icons for Time-Series Visualization and Exploratory Analysis.

    Science.gov (United States)

    Nickerson, Paul V; Baharloo, Raheleh; Wanigatunga, Amal A; Manini, Todd M; Tighe, Patrick J; Rashidi, Parisa

    2018-03-01

    The modern healthcare landscape has seen the rapid emergence of techniques and devices that temporally monitor and record physiological signals. The prevalence of time-series data within the healthcare field necessitates the development of methods that can analyze the data in order to draw meaningful conclusions. Time-series behavior is notoriously difficult to intuitively understand due to its intrinsic high-dimensionality, which is compounded in the case of analyzing groups of time series collected from different patients. Our framework, which we call transition icons, renders common patterns in a visual format useful for understanding the shared behavior within groups of time series. Transition icons are adept at detecting and displaying subtle differences and similarities, e.g., between measurements taken from patients receiving different treatment strategies or stratified by demographics. We introduce various methods that collectively allow for exploratory analysis of groups of time series, while being free of distribution assumptions and including simple heuristics for parameter determination. Our technique extracts discrete transition patterns from symbolic aggregate approXimation representations, and compiles transition frequencies into a bag of patterns constructed for each group. These transition frequencies are normalized and aligned in icon form to intuitively display the underlying patterns. We demonstrate the transition icon technique for two time-series datasets-postoperative pain scores, and hip-worn accelerometer activity counts. We believe transition icons can be an important tool for researchers approaching time-series data, as they give rich and intuitive information about collective time-series behaviors.

  16. Spatial analysis statistics, visualization, and computational methods

    CERN Document Server

    Oyana, Tonny J

    2015-01-01

    An introductory text for the next generation of geospatial analysts and data scientists, Spatial Analysis: Statistics, Visualization, and Computational Methods focuses on the fundamentals of spatial analysis using traditional, contemporary, and computational methods. Outlining both non-spatial and spatial statistical concepts, the authors present practical applications of geospatial data tools, techniques, and strategies in geographic studies. They offer a problem-based learning (PBL) approach to spatial analysis-containing hands-on problem-sets that can be worked out in MS Excel or ArcGIS-as well as detailed illustrations and numerous case studies. The book enables readers to: Identify types and characterize non-spatial and spatial data Demonstrate their competence to explore, visualize, summarize, analyze, optimize, and clearly present statistical data and results Construct testable hypotheses that require inferential statistical analysis Process spatial data, extract explanatory variables, conduct statisti...

  17. Group-wise Principal Component Analysis for Exploratory Data Analysis

    NARCIS (Netherlands)

    Camacho, J.; Rodriquez-Gomez, Rafael A.; Saccenti, E.

    2017-01-01

    In this paper, we propose a new framework for matrix factorization based on Principal Component Analysis (PCA) where sparsity is imposed. The structure to impose sparsity is defined in terms of groups of correlated variables found in correlation matrices or maps. The framework is based on three new

  18. Spatial analysis and planning under imprecision

    CERN Document Server

    Leung, Y

    1988-01-01

    The book deals with complexity, imprecision, human valuation, and uncertainty in spatial analysis and planning, providing a systematic exposure of a new philosophical and theoretical foundation for spatial analysis and planning under imprecision. Regional concepts and regionalization, spatial preference-utility-choice structures, spatial optimization with single and multiple objectives, dynamic spatial systems and their controls are analyzed in sequence.The analytical framework is based on fuzzy set theory. Basic concepts of fuzzy set theory are first discussed. Many numerical examples and emp

  19. Application of computer intensive data analysis methods to the analysis of digital images and spatial data

    DEFF Research Database (Denmark)

    Windfeld, Kristian

    1992-01-01

    linear methods. Different strategies for selecting projections (linear combinations) of multivariate images are presented. An exploratory, iterative method for finding interesting projections originated in data analysis is compared to principal components. A method for introducing spatial context...... structural images for heavy minerals based on irregularly sampled geochemical data. This methodology has proven useful in producing images that reflect real geological structures with potential application in mineral exploration. A method for removing loboratory-produced map-sheet patterns in spatial data......Computer-intensive methods for data analysis in a traditional setting has developed rapidly in the last decade. The application of and adaption of some of these methods to the analysis of multivariate digital images and spatial data are explored, evaluated and compared to well established classical...

  20. Intra-urban disparities in the quality of life in the city of Porto: a spatial analysis contribution

    OpenAIRE

    Luis Delfim Santos; Isabel Martins

    2014-01-01

    Geographical Information Systems (GIS) are an essential tool to integrate and manage large amounts of data (statistical and graphical) and to visualise the modelling efforts of the contemporary city. The further use of spatial analysis methods, in particular the exploratory analysis of data and spatial econometric models, is a promising way forward to analyse urban reality. In this analysis, we used a conceptual model and a geographical database developed for the city of Porto (Portugal) unde...

  1. Improving Skill Development: An Exploratory Study Comparing a Philosophical and an Applied Ethical Analysis Technique

    Science.gov (United States)

    Al-Saggaf, Yeslam; Burmeister, Oliver K.

    2012-01-01

    This exploratory study compares and contrasts two types of critical thinking techniques; one is a philosophical and the other an applied ethical analysis technique. The two techniques analyse an ethically challenging situation involving ICT that a recent media article raised to demonstrate their ability to develop the ethical analysis skills of…

  2. Hierarchical modeling and analysis for spatial data

    CERN Document Server

    Banerjee, Sudipto; Gelfand, Alan E

    2003-01-01

    Among the many uses of hierarchical modeling, their application to the statistical analysis of spatial and spatio-temporal data from areas such as epidemiology And environmental science has proven particularly fruitful. Yet to date, the few books that address the subject have been either too narrowly focused on specific aspects of spatial analysis, or written at a level often inaccessible to those lacking a strong background in mathematical statistics.Hierarchical Modeling and Analysis for Spatial Data is the first accessible, self-contained treatment of hierarchical methods, modeling, and dat

  3. Rapid Benefit Indicators (RBI) Spatial Analysis Tools

    Science.gov (United States)

    The Rapid Benefit Indicators (RBI) approach consists of five steps and is outlined in Assessing the Benefits of Wetland Restoration - A Rapid Benefits Indicators Approach for Decision Makers. This spatial analysis tool is intended to be used to analyze existing spatial informatio...

  4. A DIMENSIONAL ANALYSIS OF DESTINATION IMAGE VARIABLESIN A SOUTH AFRICAN CONTEXT: AN EXPLORATORY STUDY

    Directory of Open Access Journals (Sweden)

    BA Mokoena

    2016-07-01

    Full Text Available It is generally accepted in tourismliterature that destination image (DI, theimportance of which is universally acknowledged, is often used as a significantelement for local tourists in the choice of a vacation destination. The purpose ofthis study was to identify the dimensions that influence tourists’ perceptions of adestination. A comprehensive literature study of DI was undertaken. In addition, aquestionnaire was developed to elicit information from a purposively selectedsample of 350 participants who had visited the city of Durban in the KwaZulu-Natal province of South Africa during the past eightmonths prior to the datacollection. Cronbach’s alpha coefficient was used to measure the reliability of themeasurement scale. Descriptive statistics wereused to describe the sample profile.Exploratory factor analysis was conducted to identify the dimensions influencingDI. Through this process seven dimensions, namely destination appreciation,weather and climate, tourism information, travel environment, shopping,community attitudeand spatial layout were identified. Based on the findings,recommendations are made to develop strategies to improve and maintain theimage of Durban so that tourists are attracted to the city. Implications for furtherresearch are also provided.

  5. Exploratory study of the relations between spatial ability and drawing from memory.

    Science.gov (United States)

    Czarnolewski, Mark Y; Eliot, John

    2012-04-01

    Test scores of 119 students, attending either a public four-year college or a technical school, were related to their proportionality and detail drawing scores on the Memory for Designs Test. In regression models, the ETS Maze Tracing, Eliot-Price Mental Rotations, and Bender-Gestalt tests were consistent predictors of proportionality scores, with the latter two tests uniquely related to these. The ETS Shapes Memory Test and the Form Board Test were the strongest predictors for detail accuracy scores. The Shapes test predicted proportionality when the CTY Visual Memory Test BB was excluded. The models then provided support for the hypothesis that drawing designs from memory, a critical skill in drawing, regardless of whether one focuses on accuracy for proportionality scores or for detail scores, is jointly related to the measures of recognition, production, and traditional spatial ability measures. This study identified multifaceted skills in drawing from memory.

  6. High-Dimensional Exploratory Item Factor Analysis by a Metropolis-Hastings Robbins-Monro Algorithm

    Science.gov (United States)

    Cai, Li

    2010-01-01

    A Metropolis-Hastings Robbins-Monro (MH-RM) algorithm for high-dimensional maximum marginal likelihood exploratory item factor analysis is proposed. The sequence of estimates from the MH-RM algorithm converges with probability one to the maximum likelihood solution. Details on the computer implementation of this algorithm are provided. The…

  7. Bootstrap Confidence Intervals for Ordinary Least Squares Factor Loadings and Correlations in Exploratory Factor Analysis

    Science.gov (United States)

    Zhang, Guangjian; Preacher, Kristopher J.; Luo, Shanhong

    2010-01-01

    This article is concerned with using the bootstrap to assign confidence intervals for rotated factor loadings and factor correlations in ordinary least squares exploratory factor analysis. Coverage performances of "SE"-based intervals, percentile intervals, bias-corrected percentile intervals, bias-corrected accelerated percentile…

  8. An Exploratory Analysis of a Middle School Science Curriculum: Implications for Students with Learning Disabilities

    Science.gov (United States)

    Taylor, Gregory S.; Hord, Casey

    2016-01-01

    An exploratory study of a middle school curriculum directly aligned with the Next Generation Science Standards was conducted with a focus on how the curriculum addresses the instructional needs of students with learning disabilities. A descriptive analysis of a lesson on speed and velocity was conducted and implications discussed for students with…

  9. The Relationship of Bureaucratic Structure to School Climate: An Exploratory Factor Analysis of Construct Validity

    Science.gov (United States)

    Lennon, Patricia A.

    2010-01-01

    This researcher examined the relationship of bureaucratic structure to school climate by means of an exploratory factor analysis of a measure of bureaucracy developed by Hoy and Sweetland (2000) and the four dimensional measure of climate developed by Hoy, Smith, and Sweetland (2002). Since there had been no other empirical studies whose authors…

  10. An Exploratory Factor Analysis of the Sexual Orientation Counselor Competency Scale: Examining the Variable of Experience

    Science.gov (United States)

    Ali, Shainna; Lambie, Glenn; Bloom, Zachary D.

    2017-01-01

    The Sexual Orientation Counselor Competency Scale (SOCCS), developed by Bidell in 2005, measures counselors' levels of skills, awareness, and knowledge in assisting lesbian, gay, or bisexual (LGB) clients. In an effort to gain an increased understanding of the construct validity of the SOCCS, researchers performed an exploratory factor analysis on…

  11. Development of an Instrument to Measure Student Use of Academic Success Skills: An Exploratory Factor Analysis

    Science.gov (United States)

    Carey, John; Brigman, Greg; Webb, Linda; Villares, Elizabeth; Harrington, Karen

    2014-01-01

    This article describes the development of the Student Engagement in School Success Skills instrument including item development and exploratory factor analysis. The instrument was developed to measure student use of the skills and strategies identified as most critical for long-term school success that are typically taught by school counselors.

  12. The School Counselor Leadership Survey: Instrument Development and Exploratory Factor Analysis

    Science.gov (United States)

    Young, Anita; Bryan, Julia

    2015-01-01

    This study examined the factor structure of the School Counselor Leadership Survey (SCLS). Survey development was a threefold process that resulted in a 39-item survey of 801 school counselors and school counselor supervisors. The exploratory factor analysis indicated a five-factor structure that revealed five key dimensions of school counselor…

  13. Mission Attachment and Job Satisfaction among Emergency Shelter and Transitional Housing Service Professionals: An Exploratory Analysis

    Science.gov (United States)

    Fermin, Caroline P.

    2017-01-01

    This research study was an exploratory analysis to determine if a relationship existed between mission attachment and job satisfaction of emergency nonprofit domestic violence shelter/transitional housing workers. The study examined if the perceptions, beliefs, and attitudes were different between entry-level, middle-level, and senior-level…

  14. Using Small Models for Big Issues : Exploratory System Dynamics Modelling and Analysis for Insightful Crisis Management

    NARCIS (Netherlands)

    Pruyt, E.

    2010-01-01

    The main goal of this paper is to explain and illustrate different exploratory uses of small System Dynamics models for analysis and decision support in case of dynamically complex issues that are deeply uncertain. The applied focuss of the paper is the field of inter/national safety and security.

  15. Spatial Analysis Methods of Road Traffic Collisions

    DEFF Research Database (Denmark)

    Loo, Becky P. Y.; Anderson, Tessa Kate

    outlines the key issues in identifying hazardous road locations (HRLs), considers current approaches used for reducing and preventing road traffic collisions, and outlines a strategy for improved road safety. The book covers spatial accuracy, validation, and other statistical issues, as well as link......Spatial Analysis Methods of Road Traffic Collisions centers on the geographical nature of road crashes, and uses spatial methods to provide a greater understanding of the patterns and processes that cause them. Written by internationally known experts in the field of transport geography, the book...

  16. Spatial Analysis Methods of Road Traffic Collisions

    DEFF Research Database (Denmark)

    Loo, Becky P. Y.; Anderson, Tessa Kate

    Spatial Analysis Methods of Road Traffic Collisions centers on the geographical nature of road crashes, and uses spatial methods to provide a greater understanding of the patterns and processes that cause them. Written by internationally known experts in the field of transport geography, the book...... outlines the key issues in identifying hazardous road locations (HRLs), considers current approaches used for reducing and preventing road traffic collisions, and outlines a strategy for improved road safety. The book covers spatial accuracy, validation, and other statistical issues, as well as link...

  17. Spatial analysis on human brucellosis incidence in mainland China: 2004–2010

    Science.gov (United States)

    Zhang, Junhui; Yin, Fei; Zhang, Tao; Yang, Chao; Zhang, Xingyu; Feng, Zijian; Li, Xiaosong

    2014-01-01

    Objectives China has experienced a sharply increasing rate of human brucellosis in recent years. Effective spatial monitoring of human brucellosis incidence is very important for successful implementation of control and prevention programmes. The purpose of this paper is to apply exploratory spatial data analysis (ESDA) methods and the empirical Bayes (EB) smoothing technique to monitor county-level incidence rates for human brucellosis in mainland China from 2004 to 2010 by examining spatial patterns. Methods ESDA methods were used to characterise spatial patterns of EB smoothed incidence rates for human brucellosis based on county-level data obtained from the China Information System for Disease Control and Prevention (CISDCP) in mainland China from 2004 to 2010. Results EB smoothed incidence rates for human brucellosis were spatially dependent during 2004–2010. The local Moran test identified significantly high-risk clusters of human brucellosis (all p values brucellosis incidence. PMID:24713215

  18. Exploratory regression analysis: a tool for selecting models and determining predictor importance.

    Science.gov (United States)

    Braun, Michael T; Oswald, Frederick L

    2011-06-01

    Linear regression analysis is one of the most important tools in a researcher's toolbox for creating and testing predictive models. Although linear regression analysis indicates how strongly a set of predictor variables, taken together, will predict a relevant criterion (i.e., the multiple R), the analysis cannot indicate which predictors are the most important. Although there is no definitive or unambiguous method for establishing predictor variable importance, there are several accepted methods. This article reviews those methods for establishing predictor importance and provides a program (in Excel) for implementing them (available for direct download at http://dl.dropbox.com/u/2480715/ERA.xlsm?dl=1) . The program investigates all 2(p) - 1 submodels and produces several indices of predictor importance. This exploratory approach to linear regression, similar to other exploratory data analysis techniques, has the potential to yield both theoretical and practical benefits.

  19. Geostatistics and spatial analysis in biological anthropology.

    Science.gov (United States)

    Relethford, John H

    2008-05-01

    A variety of methods have been used to make evolutionary inferences based on the spatial distribution of biological data, including reconstructing population history and detection of the geographic pattern of natural selection. This article provides an examination of geostatistical analysis, a method used widely in geology but which has not often been applied in biological anthropology. Geostatistical analysis begins with the examination of a variogram, a plot showing the relationship between a biological distance measure and the geographic distance between data points and which provides information on the extent and pattern of spatial correlation. The results of variogram analysis are used for interpolating values of unknown data points in order to construct a contour map, a process known as kriging. The methods of geostatistical analysis and discussion of potential problems are applied to a large data set of anthropometric measures for 197 populations in Ireland. The geostatistical analysis reveals two major sources of spatial variation. One pattern, seen for overall body and craniofacial size, shows an east-west cline most likely reflecting the combined effects of past population dispersal and settlement. The second pattern is seen for craniofacial height and shows an isolation by distance pattern reflecting rapid spatial changes in the midlands region of Ireland, perhaps attributable to the genetic impact of the Vikings. The correspondence of these results with other analyses of these data and the additional insights generated from variogram analysis and kriging illustrate the potential utility of geostatistical analysis in biological anthropology. (c) 2008 Wiley-Liss, Inc.

  20. Practical Considerations for Using Exploratory Factor Analysis in Educational Research

    Science.gov (United States)

    Beavers, Amy S.; Lounsbury, John W.; Richards, Jennifer K.; Huck, Schuyler W.; Skolits, Gary J.; Esquivel, Shelley L.

    2013-01-01

    The uses and methodology of factor analysis are widely debated and discussed, especially the issues of rotational use, methods of confirmatory factor analysis, and adequate sample size. The variety of perspectives and often conflicting opinions can lead to confusion among researchers about best practices for using factor analysis. The focus of the…

  1. Virtual Exploratories

    DEFF Research Database (Denmark)

    Jensen, Sisse Siggaard

    2006-01-01

    -systems, the paper introduces the designing strategy referred to as virtual exploratories. Some of the advanced virtual worlds may inspire the design of such provoking and challenging virtual exploratories, and especially the Massively Multi-User Online Role-Playing Games (MMORPGS). However, if we have to learn from...... the design and activity of the advanced virtual worlds and role-playing games, then the empirical research on the actors’ activity, while they are acting, is an important precondition to it. A step towards the conception of such a designing strategy for virtual exploratories is currently pursued......, the sense-making ontology and triangle (Dervin et al., 2003), the video-interaction analysis (Henderson & Jordan, 1994), and the method of videoviews (Jensen, 2001, 2005). Also the two analytical concepts ‘intermediaries’ and ‘mediators’ that come from the actor-network theory (Latour, 2005) are introduced...

  2. Exploratory social network analysis with Pajek. - 2nd ed.

    NARCIS (Netherlands)

    de Nooy, W.; Mrvar, A.; Batagelj, V.

    2011-01-01

    This is an extensively revised and expanded second edition of the successful textbook on social network analysis integrating theory, applications, and network analysis using Pajek. The main structural concepts and their applications in social research are introduced with exercises. Pajek software

  3. Exploratory Factor Analysis of a Force Concept Inventory Data Set

    Science.gov (United States)

    Scott, Terry F.; Schumayer, Daniel; Gray, Andrew R.

    2012-01-01

    We perform a factor analysis on a "Force Concept Inventory" (FCI) data set collected from 2109 respondents. We address two questions: the appearance of conceptual coherence in student responses to the FCI and some consequences of this factor analysis on the teaching of Newtonian mechanics. We will highlight the apparent conflation of Newton's…

  4. Preprocessing and exploratory analysis of chromatographic profiles of plant extracts

    NARCIS (Netherlands)

    Hendriks, M.M.W.B.; Cruz-Juarez, L.; Bont, de D.; Hall, R.D.

    2005-01-01

    The characterization of herbal extracts to compare samples from different origin is important for robust production and quality control strategies. This characterization is now mainly performed by analysis of selected marker compounds. Metabolic fingerprinting of full metabolite profiles of plant

  5. Exploratory factor analysis of a Force Concept Inventory data set

    Directory of Open Access Journals (Sweden)

    Terry F. Scott

    2012-07-01

    Full Text Available We perform a factor analysis on a “Force Concept Inventory” (FCI data set collected from 2109 respondents. We address two questions: the appearance of conceptual coherence in student responses to the FCI and some consequences of this factor analysis on the teaching of Newtonian mechanics. We will highlight the apparent conflation of Newton’s third law with Newton’s first law in one of the FCI questions and suggest an approach to teaching that may avoid this issue. We also note the absence of a distinct factor interpretable as relating specifically to kinematics. Furthermore, we identify and discuss some of the technical difficulties which may be encountered when performing factor analysis on categorical data sets, such as is the case with FCI data sets.

  6. EXPLORATORY ANALYSIS OF ORGANIZATIONAL CULTURE IN GALATI COUNTY BUSINESS ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Gabriela GHEORGHE

    2014-06-01

    Full Text Available Based on data collected as part of the COMOR Project, developed by The Scientific Society of Management from Romania, for the analysis of organizational culture in the Romanian business environment, we have initiated an exploration using Business Intelligence tools. The purpose of this analysis is to find relevant information about the organizational culture for Galati County, starting from the results obtained in this project, and, using data mining techniques, to investigate relationships and links between responses to different survey questions, in this "mine" data, gathered by the project team effort.

  7. Exploratory data analysis of the dependencies between skin permeability, molecular weight and log P.

    Science.gov (United States)

    Kilian, D; Lemmer, H J R; Gerber, M; du Preez, J L; du Plessis, J

    2016-06-01

    Molecular weight and log P remain the most frequently used physicochemical properties in models that predict skin permeability. However, several reports over the past two decades have suggested that predictions made by these models may not be sufficiently accurate. In this study, exploratory data analysis of the probabilistic dependencies between molecular weight, log P and log Kp was performed on a dataset constructed from the combination of several popular datasets. The results suggest that, in general, molecular weight and log P are poorly correlated to log Kp. However, after employing several exploratory data analysis techniques, regions within the dataset of statistically significant dependence were identified. As an example of the applicability of the information extracted from the exploratory data analyses, a multiple linear regression model was constructed, bounded by the ranges of dependence. This model gave reasonable approximations to log Kp values obtained from skin permeability studies of selected non-steroidal ant-inflammatory drugs (NSAIDs) administered from a buffer solution and a lipid-based drug delivery system. A method of testing whether a given drug falls within the regions of statistical dependence was also presented. Knowing the ranges within which molecular weight and log P are statistically related to log Kp can supplement existing methods of screening, risk analysis or early drug development decision making to add confidence to predictions made regarding skin permeability.

  8. Interactive exploratory data analysis tool in Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Diana Furcila

    2015-04-01

    Thus, MorExAn provide us the possibility to relate histopathological data with neuropsychological and clinical variables. The aid of this interactive visualization tool brings us the possibility to find unexpected conclusions beyond the insight provided by simple statistics analysis, as well as to improve neuroscientists’ productivity.

  9. Regional Convergence of Income: Spatial Analysis

    Directory of Open Access Journals (Sweden)

    Vera Ivanovna Ivanova

    2014-12-01

    Full Text Available Russia has a huge territory and a strong interregional heterogeneity, so we can assume that geographical factors have a significant impact on the pace of economic growth in Russian regions. Therefore the article is focused on the following issues: 1 correlation between comparative advantages of geographical location and differences in growth rates; 2 impact of more developed regions on their neighbors and 3 correlation between economic growth of regions and their spatial interaction. The article is devoted to the empirical analysis of regional per capita incomes from 1996 to 2012 and explores the dynamics of the spatial autocorrelation of regional development indicator. It is shown that there is a problem of measuring the intensity of spatial dependence: factor value of Moran’s index varies greatly depending on the choice of the matrix of distances. In addition, with the help of spatial econometrics the author tests the following hypotheses: 1 there is convergence between regions for a specified period; 2 the process of beta convergence is explained by the spatial arrangement of regions and 3 there is positive impact of market size on regional growth. The author empirically confirmed all three hypotheses

  10. Observations of radiographer communication: An exploratory study using Transactional Analysis

    International Nuclear Information System (INIS)

    Booth, Lisa A.; Manning, David J.

    2006-01-01

    Purpose: Communication in medical imaging is a neglected area of research, despite the necessity for good communication if optimum diagnostic images are to be achieved. Methods: The present study has investigated the styles of communication used in medical imaging, using an approach known as Transactional Analysis. This approach has been demonstrated previously as having reliability and validity, using observations and supporting interviews with medical imaging staff, along with inter-rater observations of radiographer-patient interactions. Results: The results indicate that Transactional Analysis can be used effectively for identifying and naming interaction events in diagnostic radiography, with diagnostic radiographers using five styles of communication. Conclusion: Radiographers tend to use Parental styles of communicating; these styles are commonly associated with a practitioner-centred approach to dealing with patients which often result in non-adherence

  11. Homogeneity and heterogeneousness in European food cultures: An exploratory analysis

    DEFF Research Database (Denmark)

    Askegaard, Søren; Madsen, Tage Koed

    One type pf boundaries rarely explored in international marketing but of potentially vital importance to international marketing are the cultural boundaries dividing Europe into regions with indidvidual cultural background and different consumptui patterns. This paper explores information about...... such cultural patterns of food consumption based on information from an existing database originating from a 1989 pan-European life style suvey questioning around 20,000 people in 16 European countri divided into 79 regions. A factor analysis reduced the number of variables from 138 to 41, discovering...... cultures which could be drawn from this material. A cluster solution with 12 cluste national, 4 transnational and 1 subnational cluster) was kept as the basis for further analysis. The clusters were portrayed according to their factor scores on each of the factor variables. Likewise, the degree...

  12. Exploratory market structure analysis. Topology-sensitive methodology.

    OpenAIRE

    Mazanec, Josef

    1999-01-01

    Given the recent abundance of brand choice data from scanner panels market researchers have neglected the measurement and analysis of perceptions. Heterogeneity of perceptions is still a largely unexplored issue in market structure and segmentation studies. Over the last decade various parametric approaches toward modelling segmented perception-preference structures such as combined MDS and Latent Class procedures have been introduced. These methods, however, are not taylored for qualitative ...

  13. Spatial analysis of the tuberculosis treatment dropout, Buenos Aires, Argentina

    Science.gov (United States)

    Herrero, María Belén; Arrossi, Silvina; Ramos, Silvina; Braga, Jose Ueleres

    2015-01-01

    OBJECTIVE Identify spatial distribution patterns of the proportion of nonadherence to tuberculosis treatment and its associated factors. METHODS We conducted an ecological study based on secondary and primary data from municipalities of the metropolitan area of Buenos Aires, Argentina. An exploratory analysis of the characteristics of the area and the distributions of the cases included in the sample (proportion of nonadherence) was also carried out along with a multifactor analysis by linear regression. The variables related to the characteristics of the population, residences and families were analyzed. RESULTS Areas with higher proportion of the population without social security benefits (p = 0.007) and of households with unsatisfied basic needs had a higher risk of nonadherence (p = 0.032). In addition, the proportion of nonadherence was higher in areas with the highest proportion of households with no public transportation within 300 meters (p = 0.070). CONCLUSIONS We found a risk area for the nonadherence to treatment characterized by a population living in poverty, with precarious jobs and difficult access to public transportation. PMID:26270011

  14. Sparse Superpixel Unmixing for Exploratory Analysis of CRISM Hyperspectral Images

    Science.gov (United States)

    Thompson, David R.; Castano, Rebecca; Gilmore, Martha S.

    2009-01-01

    Fast automated analysis of hyperspectral imagery can inform observation planning and tactical decisions during planetary exploration. Products such as mineralogical maps can focus analysts' attention on areas of interest and assist data mining in large hyperspectral catalogs. In this work, sparse spectral unmixing drafts mineral abundance maps with Compact Reconnaissance Imaging Spectrometer (CRISM) images from the Mars Reconnaissance Orbiter. We demonstrate a novel "superpixel" segmentation strategy enabling efficient unmixing in an interactive session. Tests correlate automatic unmixing results based on redundant spectral libraries against hand-tuned summary products currently in use by CRISM researchers.

  15. Spatially resolved X-ray energy analysis

    International Nuclear Information System (INIS)

    Aronson, M.; Horowitz, P.

    1981-01-01

    We have constructed a proton-induced X-ray emission (PIXE) analysis system that performs one- or two-dimensional scans of a sample and stores energy spectra at each point for later analysis. This system permits examination of the spectra or the spatial distribution of a selected element as data is being gathered, and allows versatile imaging and graphing analysis later. The boundaries of the region under study can easily be altered, both for one-dimensional line scans and two-dimensional rasters. Thy system includes provisions for beam-current normalization and baseline removal. (orig.)

  16. Exploratory analysis of fines for water pollution in Bangladesh

    Directory of Open Access Journals (Sweden)

    Nabil Haque

    2017-12-01

    Full Text Available As a consequence of rapid industrialization, the waterbodies of Bangladesh have transformed into seasonal dead zones from the ensuing pollution. Despite having environmental regulations to control industrial pollution, lack of effective enforcement has jeopardized environmental quality. Evaluation of enforcement mechanisms have not gained attention from researchers until recently. This qualitative and descriptive analysis illustrates the current enforcement regime for environmental compliance in Bangladesh focusing on fines levied on polluters. Although there are no official guidelines for fines based on type of violation, this paper identified that there are differences of fines among violation based on historical data. It was also found that textile factories are not penalized heavily compared to non-textile factories. Repeat offenders were found to be penalized at the same rate. This study can be used to design appropriate penalty structure based on violation types, and reform the enforcement system so that polluters pay principle is actually implemented.

  17. Effect of dietary fish oil supplementation on the exploratory activity, emotional status and spatial memory of the aged mouse lemur, a non-human primate.

    Science.gov (United States)

    Languille, Solène; Aujard, Fabienne; Pifferi, Fabien

    2012-12-01

    The data are inconsistent about the ability of dietary omega-3 fatty acids to prevent age-associated cognitive decline. Indeed, most clinical trials have failed to demonstrate a protective effect of omega-3 fatty acids against cognitive decline, and methodological issues are still under debate. In contrast to human studies, experiments performed in adult rodents clearly indicate that omega-3 fatty acids supplement can improve behavioural and cognitive functions. The inconsistent observations between human and rodent studies highlight the importance of the use of non-human primate models. The aim of the present study was to address the impact of omega-3 fatty acids (given in the form of dietary fish oil) on exploratory activity, emotional status and spatial reference memory in the aged mouse lemur, a non-human primate. Aged animals fed fish oil exhibited decreased exploratory activity, as manifested by an increase in the latency to move and a reduced distance travelled in an open-field. The fish oil-supplemented animals exhibited no change in the anxiety level, but they were more reactive to go into the dark arms of a light/dark plus-maze. In addition, we found that fish oil supplementation did not significantly improve the spatial memory performance in the Barnes maze task. This study demonstrated for the first time that a fish oil diet initiated late in life specifically modifies the exploratory behaviour without improving the spatial memory of aged non-human primates. Omega-3 fatty acid supplementation may be effective when started early in life but less effective when started at later ages. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Social support and outcome of alcoholism treatment: an exploratory analysis.

    Science.gov (United States)

    Booth, B M; Russell, D W; Soucek, S; Laughlin, P R

    1992-01-01

    Social support is becoming recognized as a positive influence on health and health maintenance. Forms of support which bolster the patient's sense of personal efficacy should enhance the alcoholic's ability to cope with a specific stressor (i.e., overcoming his or her addiction). Patients reporting higher levels of social support during alcoholism treatment, especially support that enhances his or her self-esteem, should therefore demonstrate improved outcome compared to patients with lower levels. Sixty-one consecutive admissions to an inpatient alcoholism treatment program at a rural midwestern medical center completed an assessment of six forms of social support (Guidance, Reliable Alliance, Reassurance of Worth, Opportunity for Nurturance, Attachment, and Social Integration) in terms of support obtained from family and friends and from the treatment environment. For each patient, additional information concerning age, marital status, financial support, and previous alcohol-related hospitalizations was also obtained. Outcome of treatment was measured by readmission for an alcohol-related diagnosis within 1 year of discharge. Survival analysis found that reassurance of worth from family and friends and number of previous hospitalizations were independent and significant predictors of time to readmission. Higher levels of reassurance of worth or esteem support significantly lengthened time to readmission, with the reverse relationship found for number of previous hospitalizations. These results suggest that specific sources (family and friends) and forms (reassurance of worth) of social support are important to the recovering alcoholic and that the effect of social support on treatment outcome is independent of the alcoholic's history of prior treatment failure. Interventions or program modifications should be designed specifically to bolster these facets of social support rather than addressing more general forms of support.

  19. Social media for public health: an exploratory policy analysis.

    Science.gov (United States)

    Fast, Ingrid; Sørensen, Kristine; Brand, Helmut; Suggs, L Suzanne

    2015-02-01

    To accomplish the aims of public health practice and policy today, new forms of communication and education are being applied. Social media are increasingly relevant for public health and used by various actors. Apart from benefits, there can also be risks in using social media, but policies regulating engagement in social media is not well researched. This study examined European public health-related organizations' social media policies and describes the main components of existing policies. This research used a mixed methods approach. A content analysis of social media policies from European institutions, non-government organizations (NGOs) and social media platforms was conducted. Next, individuals responsible for social media in their organization or projects completed a survey about their social media policy. Seventy-five per cent of institutions, NGOs and platforms had a social media policy available. The primary aspects covered within existing policies included data and privacy protection, intellectual property and copyright protection and regulations for the engagement in social media. Policies were intended to regulate staff use, to secure the liability of the institution and social responsibility. Respondents also stressed the importance of self-responsibility when using social media. This study of social media policies for public health in Europe provides a first snapshot of the existence and characteristics of social media policies among European health organizations. Policies tended to focus on legal aspects, rather than the health of the social media user. The effect of such policies on social media adoption and usage behaviour remains to be examined. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  20. Exploratory factor analysis and reliability analysis with missing data: A simple method for SPSS users

    Directory of Open Access Journals (Sweden)

    Bruce Weaver

    2014-09-01

    Full Text Available Missing data is a frequent problem for researchers conducting exploratory factor analysis (EFA or reliability analysis. The SPSS FACTOR procedure allows users to select listwise deletion, pairwise deletion or mean substitution as a method for dealing with missing data. The shortcomings of these methods are well-known. Graham (2009 argues that a much better way to deal with missing data in this context is to use a matrix of expectation maximization (EM covariances(or correlations as input for the analysis. SPSS users who have the Missing Values Analysis add-on module can obtain vectors ofEM means and standard deviations plus EM correlation and covariance matrices via the MVA procedure. But unfortunately, MVA has no /MATRIX subcommand, and therefore cannot write the EM correlations directly to a matrix dataset of the type needed as input to the FACTOR and RELIABILITY procedures. We describe two macros that (in conjunction with an intervening MVA command carry out the data management steps needed to create two matrix datasets, one containing EM correlations and the other EM covariances. Either of those matrix datasets can then be used asinput to the FACTOR procedure, and the EM correlations can also be used as input to RELIABILITY. We provide an example that illustrates the use of the two macros to generate the matrix datasets and how to use those datasets as input to the FACTOR and RELIABILITY procedures. We hope that this simple method for handling missing data will prove useful to both students andresearchers who are conducting EFA or reliability analysis.

  1. Exploratory factor analysis of the Dizziness Handicap Inventory (German version).

    Science.gov (United States)

    Kurre, Annette; Bastiaenen, Caroline Hg; van Gool, Christel Jaw; Gloor-Juzi, Thomas; de Bruin, Eling D; Straumann, Dominik

    2010-03-15

    The Dizziness Handicap Inventory (DHI) is a validated, self-report questionnaire which is widely used as an outcome measure. Previous studies supported the multidimensionality of the DHI, but not the original subscale structure. The objectives of this survey were to explore the dimensions of the Dizziness Handicap Inventory - German version, and to investigate the associations of the retained factors with items assessing functional disability and the Hospital Anxiety and Depression Scale (HADS). Secondly we aimed to explore the retained factors according to the International Classification of Functioning, Disability and Health (ICF). Patients were recruited from a tertiary centre for vertigo, dizziness or balance disorders. They filled in two questionnaires: (1) The DHI assesses precipitating physical factors associated with dizziness/unsteadiness and functional/emotional consequences of symptoms. (2) The HADS assesses non-somatic symptoms of anxiety and depression. In addition, patients answered the third question of the University of California Los Angeles-Dizziness Questionnaire which covers the impact of dizziness and unsteadiness on everyday activities. Principal component analysis (PCA) was performed to explore the dimensions of the DHI. Associations were estimated by Spearman correlation coefficients. One hundred ninety-four patients with dizziness or unsteadiness associated with a vestibular disorder, mean age (standard deviation) of 50.6 (13.6) years, participated. Based on eigenvalues greater one respectively the scree plot we analysed diverse factor solutions. The 3-factor solution seems to be reliable, clinically relevant and can partly be explained with the ICF. It explains 49.2% of the variance. Factor 1 comprises the effect of dizziness and unsteadiness on emotion and participation, factor 2 informs about specific activities or effort provoking dizziness and unsteadiness, and factor 3 focuses on self-perceived walking ability in relation to

  2. Exploratory factor analysis of the Dizziness Handicap Inventory (German version

    Directory of Open Access Journals (Sweden)

    de Bruin Eling D

    2010-03-01

    Full Text Available Abstract Background The Dizziness Handicap Inventory (DHI is a validated, self-report questionnaire which is widely used as an outcome measure. Previous studies supported the multidimensionality of the DHI, but not the original subscale structure. The objectives of this survey were to explore the dimensions of the Dizziness Handicap Inventory - German version, and to investigate the associations of the retained factors with items assessing functional disability and the Hospital Anxiety and Depression Scale (HADS. Secondly we aimed to explore the retained factors according to the International Classification of Functioning, Disability and Health (ICF. Methods Patients were recruited from a tertiary centre for vertigo, dizziness or balance disorders. They filled in two questionnaires: (1 The DHI assesses precipitating physical factors associated with dizziness/unsteadiness and functional/emotional consequences of symptoms. (2 The HADS assesses non-somatic symptoms of anxiety and depression. In addition, patients answered the third question of the University of California Los Angeles-Dizziness Questionnaire which covers the impact of dizziness and unsteadiness on everyday activities. Principal component analysis (PCA was performed to explore the dimensions of the DHI. Associations were estimated by Spearman correlation coefficients. Results One hundred ninety-four patients with dizziness or unsteadiness associated with a vestibular disorder, mean age (standard deviation of 50.6 (13.6 years, participated. Based on eigenvalues greater one respectively the scree plot we analysed diverse factor solutions. The 3-factor solution seems to be reliable, clinically relevant and can partly be explained with the ICF. It explains 49.2% of the variance. Factor 1 comprises the effect of dizziness and unsteadiness on emotion and participation, factor 2 informs about specific activities or effort provoking dizziness and unsteadiness, and factor 3 focuses on self

  3. The development and exploratory analysis of the Back Pain Attitudes Questionnaire (Back-PAQ).

    Science.gov (United States)

    Darlow, Ben; Perry, Meredith; Mathieson, Fiona; Stanley, James; Melloh, Markus; Marsh, Reginald; Baxter, G David; Dowell, Anthony

    2014-05-23

    To develop an instrument to assess attitudes and underlying beliefs about back pain, and subsequently investigate its internal consistency and underlying structures. The instrument was developed by a multidisciplinary team of clinicians and researchers based on analysis of qualitative interviews with people experiencing acute and chronic back pain. Exploratory analysis was conducted using data from a population-based cross-sectional survey. Qualitative interviews with community-based participants and subsequent postal survey. Instrument development informed by interviews with 12 participants with acute back pain and 11 participants with chronic back pain. Data for exploratory analysis collected from New Zealand residents and citizens aged 18 years and above. 1000 participants were randomly selected from the New Zealand Electoral Roll. 602 valid responses were received. The 34-item Back Pain Attitudes Questionnaire (Back-PAQ) was developed. Internal consistency was evaluated by the Cronbach α coefficient. Exploratory analysis investigated the structure of the data using Principal Component Analysis. The 34-item long form of the scale had acceptable internal consistency (α=0.70; 95% CI 0.66 to 0.73). Exploratory analysis identified five two-item principal components which accounted for 74% of the variance in the reduced data set: 'vulnerability of the back'; 'relationship between back pain and injury'; 'activity participation while experiencing back pain'; 'prognosis of back pain' and 'psychological influences on recovery'. Internal consistency was acceptable for the reduced 10-item scale (α=0.61; 95% CI 0.56 to 0.66) and the identified components (α between 0.50 and 0.78). The 34-item long form of the scale may be appropriate for use in future cross-sectional studies. The 10-item short form may be appropriate for use as a screening tool, or an outcome assessment instrument. Further testing of the 10-item Back-PAQ's construct validity, reliability

  4. Non-linear mapping for exploratory data analysis in functional genomics

    Directory of Open Access Journals (Sweden)

    Chesneau Alban

    2005-01-01

    Full Text Available Abstract Background Several supervised and unsupervised learning tools are available to classify functional genomics data. However, relatively less attention has been given to exploratory, visualisation-driven approaches. Such approaches should satisfy the following factors: Support for intuitive cluster visualisation, user-friendly and robust application, computational efficiency and generation of biologically meaningful outcomes. This research assesses a relaxation method for non-linear mapping that addresses these concerns. Its applications to gene expression and protein-protein interaction data analyses are investigated Results Publicly available expression data originating from leukaemia, round blue-cell tumours and Parkinson disease studies were analysed. The method distinguished relevant clusters and critical analysis areas. The system does not require assumptions about the inherent class structure of the data, its mapping process is controlled by only one parameter and the resulting transformations offer intuitive, meaningful visual displays. Comparisons with traditional mapping models are presented. As a way of promoting potential, alternative applications of the methodology presented, an example of exploratory data analysis of interactome networks is illustrated. Data from the C. elegans interactome were analysed. Results suggest that this method might represent an effective solution for detecting key network hubs and for clustering biologically meaningful groups of proteins. Conclusion A relaxation method for non-linear mapping provided the basis for visualisation-driven analyses using different types of data. This study indicates that such a system may represent a user-friendly and robust approach to exploratory data analysis. It may allow users to gain better insights into the underlying data structure, detect potential outliers and assess assumptions about the cluster composition of the data.

  5. Spatially Resolved Analysis of Bragg Selectivity

    Directory of Open Access Journals (Sweden)

    Tina Sabel

    2015-11-01

    Full Text Available This paper targets an inherent control of optical shrinkage in photosensitive polymers, contributing by means of spatially resolved analysis of volume holographic phase gratings. Point by point scanning of the local material response to the Gaussian intensity distribution of the recording beams is accomplished. Derived information on the local grating period and grating slant is evaluated by mapping of optical shrinkage in the lateral plane as well as through the depth of the layer. The influence of recording intensity, exposure duration and the material viscosity on the Bragg selectivity is investigated.

  6. ANALYSIS OF PRO-POOR GROWTH AMONG THE MUNICIPAL DISTRICTS OF THE STATE OF CEARÁ - BRAZIL: SPATIAL APPROACH

    Directory of Open Access Journals (Sweden)

    Wellington Ribeiro Justo

    2014-04-01

    Full Text Available This article investigates the for-poor growth among the municipal districts of the State of Ceará in 2003. Initially it explores the recent literature of the theme as well as of the spatial econometric. Soon after it makes the spatial analysis of the variables through maps and in more robust way through the Exploratory Analysis of Given Spatial (AEDE being used the LISA methodology (Local Indicators of Spatial Association and the statistics I of Moran. Estimates the elasticity income-poverty and elasticity inequality-poverty. The tests indicated the need to incorporate variables in the estimates that learn the spatial externalities. The results suggest for-poor growth in the municipal districts from Ceará in agreement with results aggregate for the Ceará state appointed in recent literature.

  7. Development of exploratory approach for scenario analysis in the performance assessment of geological disposal

    International Nuclear Information System (INIS)

    Makino, Hitoshi; Ishiguro, Katsuhiko; Umeki, Hiroyuki; Oyamada, Kiyoshi; Takase, Hiroyasu; Grindrod, Peter

    1998-01-01

    It becomes difficult to apply the ordinary method for scenario analysis as number of the processes and complexity in their interrelations are increased. For this problem, an exploratory approach, that can perform scenario analysis on wider range of problems, was developed. The approach includes ensemble runs of a mass transport model, that was developed as a generic and flexible model and can cover effects of various processes on the mass transport, and analysis of sensitivity structure among the input and output space of the ensemble runs. The technique of clustering and principal component analysis were applied in the approach. As the result of its test application, applicability of the approach was confirmed to identify important processes from number of the processes in the systematic and objective manner. (author)

  8. Hearing health network: a spatial analysis

    Directory of Open Access Journals (Sweden)

    Camila Ferreira de Rezende

    2015-06-01

    Full Text Available INTRODUCTION: In order to meet the demands of the patient population with hearing impairment, the Hearing Health Care Network was created, consisting of primary care actions of medium and high complexity. Spatial analysis through geoprocessing is a way to understand the organization of such services. OBJECTIVE: To analyze the organization of the Hearing Health Care Network of the State of Minas Gerais. METHODS: Cross-sectional analytical study using geoprocessing techniques. The absolute frequency and the frequency per 1000 inhabitants of the following variables were analyzed: assessment and diagnosis, selection and adaptation of hearing aids, follow-up, and speech therapy. The spatial analysis unit was the health micro-region. RESULTS: The assessment and diagnosis, selection, and adaptation of hearing aids and follow-up had a higher absolute number in the micro-regions with hearing health services. The follow-up procedure showed the lowest occurrence. Speech therapy showed higher occurrence in the state, both in absolute numbers, as well as per population. CONCLUSION: The use of geoprocessing techniques allowed the identification of the care flow as a function of the procedure performance frequency, population concentration, and territory distribution. All procedures offered by the Hearing Health Care Network are performed for users of all micro-regions of the state.

  9. An Exploratory Factor Analysis and Reliability Analysis of the Student Online Learning Readiness (SOLR) Instrument

    Science.gov (United States)

    Yu, Taeho; Richardson, Jennifer C.

    2015-01-01

    The purpose of this study was to develop an effective instrument to measure student readiness in online learning with reliable predictors of online learning success factors such as learning outcomes and learner satisfaction. The validity and reliability of the Student Online Learning Readiness (SOLR) instrument were tested using exploratory factor…

  10. Application of exploratory factor analysis to assess fish consumption in a university community

    Directory of Open Access Journals (Sweden)

    Erika da Silva Maciel

    2013-03-01

    Full Text Available The objective of this research was to use the technique of Exploratory Factor Analysis (EFA for the adequacy of a tool for the assessment of fish consumption and the characteristics involved in this process. Data were collected during a campaign to encourage fish consumption in Brazil with the voluntarily participation of members of a university community. An assessment instrument consisting of multiple-choice questions and a five-point Likert scale was designed and used to measure the importance of certain attributes that influence the choice and consumption of fish. This study sample was composed of of 224 individuals, the majority were women (65.6%. With regard to the frequency of fish consumption, 37.67% of the volunteers interviewed said they consume the product two or three times a month, and 29.6% once a week. The Exploratory Factor Analysis (EFA was used to group the variables; the extraction was made using the principal components and the rotation using the Quartimax method. The results show clusters in two main constructs, quality and consumption with Cronbach Alpha coefficients of 0.75 and 0.69, respectively, indicating good internal consistency.

  11. Improving Genomic Prediction in Cassava Field Experiments Using Spatial Analysis

    Directory of Open Access Journals (Sweden)

    Ani A. Elias

    2018-01-01

    Full Text Available Cassava (Manihot esculenta Crantz is an important staple food in sub-Saharan Africa. Breeding experiments were conducted at the International Institute of Tropical Agriculture in cassava to select elite parents. Taking into account the heterogeneity in the field while evaluating these trials can increase the accuracy in estimation of breeding values. We used an exploratory approach using the parametric spatial kernels Power, Spherical, and Gaussian to determine the best kernel for a given scenario. The spatial kernel was fit simultaneously with a genomic kernel in a genomic selection model. Predictability of these models was tested through a 10-fold cross-validation method repeated five times. The best model was chosen as the one with the lowest prediction root mean squared error compared to that of the base model having no spatial kernel. Results from our real and simulated data studies indicated that predictability can be increased by accounting for spatial variation irrespective of the heritability of the trait. In real data scenarios we observed that the accuracy can be increased by a median value of 3.4%. Through simulations, we showed that a 21% increase in accuracy can be achieved. We also found that Range (row directional spatial kernels, mostly Gaussian, explained the spatial variance in 71% of the scenarios when spatial correlation was significant.

  12. Improving Genomic Prediction in Cassava Field Experiments Using Spatial Analysis.

    Science.gov (United States)

    Elias, Ani A; Rabbi, Ismail; Kulakow, Peter; Jannink, Jean-Luc

    2018-01-04

    Cassava ( Manihot esculenta Crantz) is an important staple food in sub-Saharan Africa. Breeding experiments were conducted at the International Institute of Tropical Agriculture in cassava to select elite parents. Taking into account the heterogeneity in the field while evaluating these trials can increase the accuracy in estimation of breeding values. We used an exploratory approach using the parametric spatial kernels Power, Spherical, and Gaussian to determine the best kernel for a given scenario. The spatial kernel was fit simultaneously with a genomic kernel in a genomic selection model. Predictability of these models was tested through a 10-fold cross-validation method repeated five times. The best model was chosen as the one with the lowest prediction root mean squared error compared to that of the base model having no spatial kernel. Results from our real and simulated data studies indicated that predictability can be increased by accounting for spatial variation irrespective of the heritability of the trait. In real data scenarios we observed that the accuracy can be increased by a median value of 3.4%. Through simulations, we showed that a 21% increase in accuracy can be achieved. We also found that Range (row) directional spatial kernels, mostly Gaussian, explained the spatial variance in 71% of the scenarios when spatial correlation was significant. Copyright © 2018 Elias et al.

  13. Cross-country Analysis of ICT and Education Indicators: An Exploratory Study

    Science.gov (United States)

    Pratama, Ahmad R.

    2017-03-01

    This paper explores the relationship between world ICT and education indicators by using the latest available data from World Bank and UNESCO in range of 2011-2014 with the help of different exploratory methods such as principal component analysis (PCA), factor analysis (FA), cluster analysis, and ordinary least square (OLS) regression. After dealing with all missing values, 119 countries were included in the final dataset. The findings show that most ICT and education indicators are highly associated with income of the respective country and therefore confirm the existence of digital divide in ICT utilization and participation gap in education between rich and poor countries. It also indicates that digital divide and participation gap is highly associated with each other. Finally, the findings also confirm reverse causality in ICT and education; higher participation rate in education increases technology utilization, which in turn helps promote better outcomes of education.

  14. Geospatial analysis platform: Supporting strategic spatial analysis and planning

    CSIR Research Space (South Africa)

    Naude, A

    2008-11-01

    Full Text Available Whilst there have been rapid advances in satellite imagery and related fine resolution mapping and web-based interfaces (e.g. Google Earth), the development of capabilities for strategic spatial analysis and planning support has lagged behind...

  15. Determining the Number of Factors to Retain in an Exploratory Factor Analysis Using Comparison Data of Known Factorial Structure

    Science.gov (United States)

    Ruscio, John; Roche, Brendan

    2012-01-01

    Exploratory factor analysis (EFA) is used routinely in the development and validation of assessment instruments. One of the most significant challenges when one is performing EFA is determining how many factors to retain. Parallel analysis (PA) is an effective stopping rule that compares the eigenvalues of randomly generated data with those for…

  16. Spectral Modelling for Spatial Network Analysis

    NARCIS (Netherlands)

    Nourian, P.; Rezvani, S.; Sariyildiz, I.S.; van der Hoeven, F.D.; Attar, Ramtin; Chronis, Angelos; Hanna, Sean; Turrin, Michela

    2016-01-01

    Spatial Networks represent the connectivity structure between units of space as a weighted graph whose links are weighted as to the strength of connections. In case of urban spatial networks, the units of space correspond closely to streets and in architectural spatial networks the units correspond

  17. Exploratory analysis of diffusion tensor imaging in children with attention deficit hyperactivity disorder: evidence of abnormal white matter structure.

    Science.gov (United States)

    Pastura, Giuseppe; Doering, Thomas; Gasparetto, Emerson Leandro; Mattos, Paulo; Araújo, Alexandra Prüfer

    2016-06-01

    Abnormalities in the white matter microstructure of the attentional system have been implicated in the aetiology of attention deficit hyperactivity disorder (ADHD). Diffusion tensor imaging (DTI) is a promising magnetic resonance imaging (MRI) technology that has increasingly been used in studies of white matter microstructure in the brain. The main objective of this work was to perform an exploratory analysis of white matter tracts in a sample of children with ADHD versus typically developing children (TDC). For this purpose, 13 drug-naive children with ADHD of both genders underwent MRI using DTI acquisition methodology and tract-based spatial statistics. The results were compared to those of a sample of 14 age- and gender-matched TDC. Lower fractional anisotropy was observed in the splenium of the corpus callosum, right superior longitudinal fasciculus, bilateral retrolenticular part of the internal capsule, bilateral inferior fronto-occipital fasciculus, left external capsule and posterior thalamic radiation (including right optic radiation). We conclude that white matter tracts in attentional and motor control systems exhibited signs of abnormal microstructure in this sample of drug-naive children with ADHD.

  18. Global innovation networks and university-firm interactions: an exploratory survey analysis

    Directory of Open Access Journals (Sweden)

    Gustavo Britto

    2015-02-01

    Full Text Available The literature on Global Innovation Networks has contributed to identify changes in the innovation activities of multinational corporations. Although university-firm interactions are seen as an important factor for the emergence of GINs, their role has received limited attention. This paper aims to fill this gap in two ways. First, it carries out an exploratory analysis of an original survey dataset, of firms in three industrial sectors from nine developed and developing countries. Second, the paper analyses whether the role of universities in global innovation networks is related to national systems of innovation with varying degrees of maturity. Multiple correspondence analysis and a Probit model are used to establish the relevance of key factors in driving GINs. The results identify distinctive profiles constructed mainly according to firm characteristics, but reflecting country specific patterns of association. The Probit model confirms that internationalization processes and the existence of local interactions substantially increase the probability of interactions with international institutions.

  19. Exploratory Analysis of Multivariate Data (Unsupervised Image Segmentation and Data Driven Linear and Nonlinear Decomposition)

    DEFF Research Database (Denmark)

    Hilger, Klaus Baggesen

    2002-01-01

    This work describes different methods that are useful in the analysis of multivariate single and multiset data. The thesis covers selected aspects of relevant data analysis techniques in this context. Methods dedicated to handling data of a spatial nature are of primary interest with focus on dat...

  20. Participative Spatial Scenario Analysis for Alpine Ecosystems.

    Science.gov (United States)

    Kohler, Marina; Stotten, Rike; Steinbacher, Melanie; Leitinger, Georg; Tasser, Erich; Schirpke, Uta; Tappeiner, Ulrike; Schermer, Markus

    2017-10-01

    Land use and land cover patterns are shaped by the interplay of human and ecological processes. Thus, heterogeneous cultural landscapes have developed, delivering multiple ecosystem services. To guarantee human well-being, the development of land use types has to be evaluated. Scenario development and land use and land cover change models are well-known tools for assessing future landscape changes. However, as social and ecological systems are inextricably linked, land use-related management decisions are difficult to identify. The concept of social-ecological resilience can thereby provide a framework for understanding complex interlinkages on multiple scales and from different disciplines. In our study site (Stubai Valley, Tyrol/Austria), we applied a sequence of steps including the characterization of the social-ecological system and identification of key drivers that influence farmers' management decisions. We then developed three scenarios, i.e., "trend", "positive" and "negative" future development of farming conditions and assessed respective future land use changes. Results indicate that within the "trend" and "positive" scenarios pluri-activity (various sources of income) prevents considerable changes in land use and land cover and promotes the resilience of farming systems. Contrarily, reductions in subsidies and changes in consumer behavior are the most important key drivers in the negative scenario and lead to distinct abandonment of grassland, predominantly in the sub-alpine zone of our study site. Our conceptual approach, i.e., the combination of social and ecological methods and the integration of local stakeholders' knowledge into spatial scenario analysis, resulted in highly detailed and spatially explicit results that can provide a basis for further community development recommendations.

  1. Participative Spatial Scenario Analysis for Alpine Ecosystems

    Science.gov (United States)

    Kohler, Marina; Stotten, Rike; Steinbacher, Melanie; Leitinger, Georg; Tasser, Erich; Schirpke, Uta; Tappeiner, Ulrike; Schermer, Markus

    2017-10-01

    Land use and land cover patterns are shaped by the interplay of human and ecological processes. Thus, heterogeneous cultural landscapes have developed, delivering multiple ecosystem services. To guarantee human well-being, the development of land use types has to be evaluated. Scenario development and land use and land cover change models are well-known tools for assessing future landscape changes. However, as social and ecological systems are inextricably linked, land use-related management decisions are difficult to identify. The concept of social-ecological resilience can thereby provide a framework for understanding complex interlinkages on multiple scales and from different disciplines. In our study site (Stubai Valley, Tyrol/Austria), we applied a sequence of steps including the characterization of the social-ecological system and identification of key drivers that influence farmers' management decisions. We then developed three scenarios, i.e., "trend", "positive" and "negative" future development of farming conditions and assessed respective future land use changes. Results indicate that within the "trend" and "positive" scenarios pluri-activity (various sources of income) prevents considerable changes in land use and land cover and promotes the resilience of farming systems. Contrarily, reductions in subsidies and changes in consumer behavior are the most important key drivers in the negative scenario and lead to distinct abandonment of grassland, predominantly in the sub-alpine zone of our study site. Our conceptual approach, i.e., the combination of social and ecological methods and the integration of local stakeholders' knowledge into spatial scenario analysis, resulted in highly detailed and spatially explicit results that can provide a basis for further community development recommendations.

  2. Spatial Uncertainty Analysis of Ecological Models

    Energy Technology Data Exchange (ETDEWEB)

    Jager, H.I.; Ashwood, T.L.; Jackson, B.L.; King, A.W.

    2000-09-02

    The authors evaluated the sensitivity of a habitat model and a source-sink population model to spatial uncertainty in landscapes with different statistical properties and for hypothetical species with different habitat requirements. Sequential indicator simulation generated alternative landscapes from a source map. Their results showed that spatial uncertainty was highest for landscapes in which suitable habitat was rare and spatially uncorrelated. Although, they were able to exert some control over the degree of spatial uncertainty by varying the sampling density drawn from the source map, intrinsic spatial properties (i.e., average frequency and degree of spatial autocorrelation) played a dominant role in determining variation among realized maps. To evaluate the ecological significance of landscape variation, they compared the variation in predictions from a simple habitat model to variation among landscapes for three species types. Spatial uncertainty in predictions of the amount of source habitat depended on both the spatial life history characteristics of the species and the statistical attributes of the synthetic landscapes. Species differences were greatest when the landscape contained a high proportion of suitable habitat. The predicted amount of source habitat was greater for edge-dependent (interior) species in landscapes with spatially uncorrelated(correlated) suitable habitat. A source-sink model demonstrated that, although variation among landscapes resulted in relatively little variation in overall population growth rate, this spatial uncertainty was sufficient in some situations, to produce qualitatively different predictions about population viability (i.e., population decline vs. increase).

  3. EXPLORATORY DATA ANALYSIS AND MULTIVARIATE STRATEGIES FOR REVEALING MULTIVARIATE STRUCTURES IN CLIMATE DATA

    Directory of Open Access Journals (Sweden)

    2016-12-01

    Full Text Available This paper is on data analysis strategy in a complex, multidimensional, and dynamic domain. The focus is on the use of data mining techniques to explore the importance of multivariate structures; using climate variables which influences climate change. Techniques involved in data mining exercise vary according to the data structures. The multivariate analysis strategy considered here involved choosing an appropriate tool to analyze a process. Factor analysis is introduced into data mining technique in order to reveal the influencing impacts of factors involved as well as solving for multicolinearity effect among the variables. The temporal nature and multidimensionality of the target variables is revealed in the model using multidimensional regression estimates. The strategy of integrating the method of several statistical techniques, using climate variables in Nigeria was employed. R2 of 0.518 was obtained from the ordinary least square regression analysis carried out and the test was not significant at 5% level of significance. However, factor analysis regression strategy gave a good fit with R2 of 0.811 and the test was significant at 5% level of significance. Based on this study, model building should go beyond the usual confirmatory data analysis (CDA, rather it should be complemented with exploratory data analysis (EDA in order to achieve a desired result.

  4. Analysis of supply chain management in a university restaurant through exploratory study

    Directory of Open Access Journals (Sweden)

    Anna Paula Galvão Scheidegger

    2015-02-01

    Full Text Available The service sector has been gaining increasing relevance in the Brazilian economy and society. However, the challenges faced by the enterprises, especially small and micro enterprises, are numerous when considering the competitiveness and the difficulties imposed by the Brazilian market structure. Thus, understanding the supply chain management of small business becomes extremely important, once it can contribute to their survival. Therefore, this study aims to conduct an assessment of the supply chain management process within the service sector. For this, it was adopted as object of study a university restaurant, which while face the usual challenges of micro enterprises, also has special characteristics that make the process even more complex. With exploratory character and using qualitative research, the work developed through mapping tools such as SIPOC and SWOT analysis, a better understanding of the context and identified some opportunities for further study, thus complying with the proposed objectives.

  5. Spatial Pattern Analysis of Heavy Metals in Beijing Agricultural Soils Based on Spatial Autocorrelation Statistics

    Science.gov (United States)

    Huo, Xiao-Ni; Zhang, Wei-Wei; Sun, Dan-Feng; Li, Hong; Zhou, Lian-Di; Li, Bao-Guo

    2011-01-01

    This study explored the spatial pattern of heavy metals in Beijing agricultural soils using Moran’s I statistic of spatial autocorrelation. The global Moran’s I result showed that the spatial dependence of Cr, Ni, Zn, and Hg changed with different spatial weight matrixes, and they had significant and positive global spatial correlations based on distance weight. The spatial dependence of the four metals was scale-dependent on distance, but these scale effects existed within a threshold distance of 13 km, 32 km, 50 km, and 29 km, respectively for Cr, Ni, Zn, and Hg. The maximal spatial positive correlation range was 57 km, 70 km, 57 km, and 55 km for Cr, Ni, Zn, and Hg, respectively and these were not affected by sampling density. Local spatial autocorrelation analysis detected the locations of spatial clusters and spatial outliers and revealed that the pollution of these four metals occurred in significant High-high spatial clusters, Low-high, or even High-low spatial outliers. Thus, three major areas were identified and should be receiving more attention: the first was the northeast region of Beijing, where Cr, Zn, Ni, and Hg had significant increases. The second was the southeast region of Beijing where wastewater irrigation had strongly changed the content of metals, particularly of Cr and Zn, in soils. The third area was the urban fringe around city, where Hg showed a significant increase. PMID:21776217

  6. Using exploratory factor analysis of FFQ data to identify dietary patterns among Yup'ik people.

    Science.gov (United States)

    Ryman, Tove K; Austin, Melissa A; Hopkins, Scarlett; Philip, Jacques; O'Brien, Diane; Thummel, Kenneth; Boyer, Bert B

    2014-03-01

    An FFQ developed by the Center for Alaska Native Health Research for studies in Yup'ik people includes market foods and subsistence foods such as moose, seal, waterfowl and salmon that may be related to disease risk. Because the FFQ contains >100 food items, we sought to characterize dietary patterns more simply for use in ongoing pharmacogenomics studies. Exploratory factor analysis was used to derive a small number of 'factors' that explain a substantial amount of the variation in the Yup'ik diet. We estimated factor scores and measured associations with demographic characteristics and biomarkers. South-west Alaska, USA. Yup'ik people (n 358) aged ≥18 years. We identified three factors that each accounted for ≥10 % of the common variance: the first characterized by 'processed foods' (e.g. salty snacks, sweetened cereals); the second by 'fruits and vegetables' (e.g. fresh citrus, potato salad); and the third by 'subsistence foods' (seal or walrus soup, non-oily fish). Participants from coastal communities had higher values for the 'subsistence' factor, whereas participants from inland communities had higher values for the 'fruits and vegetables' factor. A biomarker of marine intake, δ 15N, was correlated with the 'subsistence' factor, whereas a biomarker of corn- and sugarcane-based market food intake, δ 13C, was correlated with 'processed foods'. The exploratory factor analysis identified three factors that appeared to reflect dietary patterns among Yup'ik based on associations with participant characteristics and biomarkers. These factors will be useful for chronic disease studies in this population.

  7. An Exploratory Analysis of Work Engagement, Satisfaction, and Depression in Psychiatry Residents.

    Science.gov (United States)

    Agarwal, Gaurava; Karpouzian, Tatiana

    2016-02-01

    This exploratory study aims to measure work engagement levels in psychiatry residents at three psychiatry residency programs using the Utrecht Work Engagement Scale (UWES). In addition, the study investigates the relationship between total engagement and its subscales, resident satisfaction, and a depression screen. Recruitment of 53/79 residents from three psychiatry residency programs in Illinois was completed. The residents were administered a questionnaire consisting of the UWES, the Primary Care Evaluation of Mental Disorders (Prime-MD) depression screen, and a residency satisfaction scale. Statistical analysis using independent samples t test and a one-way analysis of variance was used to assess differences on engagement total score and subscales and satisfaction scale. A logistic regression was used with the engagement subscales and the satisfaction scale as predictors of belonging to the depressed or non-depressed group. Psychiatry residents scored in the high range for total engagement and all its subscales except for vigor which was in the moderate range. Residents who screened positive for depression reported lower total engagement than those who were negative on the depression screen. Vigor was the only significant predictor (p = .004) of being in the depressed group after logistic regression. Total engagement and the subscale of dedication significantly predicted overall residency satisfaction (β = .473, p = .016). Higher total UWES-15 and its subscales of vigor and dedication are correlated with a lower rate of screening positive for depression and higher residency satisfaction. This exploratory study lends support for further study of this psychological construct in medical training programs, but replication is needed.

  8. Challenges in covering health disparities in local news media: an exploratory analysis assessing views of journalists.

    Science.gov (United States)

    Wallington, Sherrie Flynt; Blake, Kelly D; Taylor-Clark, Kalahn; Viswanath, K

    2010-10-01

    News coverage of health topics influences knowledge, attitudes, and behaviors at the individual level, and agendas and actions at the institutional and policy levels. Because disparities in health often are the result of social inequalities that require community-level or policy-level solutions, news stories employing a health disparities news frame may contribute to agenda-setting among opinion leaders and policymakers and lead to policy efforts aimed at reducing health disparities. This study objective was to conduct an exploratory analysis to qualitatively describe barriers that health journalists face when covering health disparities in local media. Between June and October 2007, 18 journalists from television, print, and radio in Boston, Lawrence, and Worcester, Massachusetts, were recruited using a purposive sampling technique. In-depth, semi-structured interviews were conducted by telephone, and the crystallization/immersion method was used to conduct a qualitative analysis of interview transcripts. Our results revealed that journalists said that they consider several angles when developing health stories, including public impact and personal behavior change. Challenges to employing a health disparities frame included inability to translate how research findings may impact different socioeconomic groups, and difficulty understanding how findings may translate across racial/ethnic groups. Several journalists reported that disparities-focused stories are "less palatable" for some audiences. This exploratory study offers insights into the challenges that local news media face in using health disparities news frames in their routine coverage of health news. Public health practitioners may use these findings to inform communication efforts with local media in order to advance the public dialogue about health disparities.

  9. Costs of Quality: Exploratory Analysis of Hidden Elements and Prioritization using Analytic Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Sailaja A

    2015-02-01

    Full Text Available Cost of Quality analysis is emerged as an effective tool for the industrial managers for pinpointing the deficiencies in the system as well as for identifying the improvement areas by highlighting the cost reduction opportunities. However , this analysis will be fully effective only if it is further extended to identify the cost incurred in ensuring quality in all areas of the supply chain including the hidden costs and costs of missed out opportunities. Most of the hidden elements of quality costs are difficult to track and not accounted by the traditional accounting tools. An exploratory analysis is made in this research to identify the hidden elements of quality costs in manufacturing industry. Further, the identified cost elements are classified into various groups for better analysis and, finally, prioritized to identify the vital few among them. Analytic Hierarchy Process (AHP technique which is one of the most popular Multi Criteria Decision Method (MCDM and Pareto analysis were used in this study for prioritizing the hidden quality cost elements based on their degree of impact on overall cost of quality. By this analysis, the key cost elements which are to be addressed to reduce the overall cost of quality are identified.

  10. Spatial analysis of NDVI readings with difference sampling density

    Science.gov (United States)

    Advanced remote sensing technologies provide research an innovative way of collecting spatial data for use in precision agriculture. Sensor information and spatial analysis together allow for a complete understanding of the spatial complexity of a field and its crop. The objective of the study was...

  11. Spatial Econometric data analysis: moving beyond traditional models

    NARCIS (Netherlands)

    Florax, R.J.G.M.; Vlist, van der A.J.

    2003-01-01

    This article appraises recent advances in the spatial econometric literature. It serves as the introduction too collection of new papers on spatial econometric data analysis brought together in this special issue, dealing specifically with new extensions to the spatial econometric modeling

  12. A Demonstration of the Impact of Outliers on the Decisions about the Number of Factors in Exploratory Factor Analysis

    Science.gov (United States)

    Liu, Yan; Zumbo, Bruno D.; Wu, Amery D.

    2012-01-01

    Previous studies have rarely examined the impact of outliers on the decisions about the number of factors to extract in an exploratory factor analysis. The few studies that have investigated this issue have arrived at contradictory conclusions regarding whether outliers inflated or deflated the number of factors extracted. By systematically…

  13. Exploratory Two-Level Analysis of Individual- and School-Level Factors on Truant Youth Emotional/Psychological Functioning

    Science.gov (United States)

    Dembo, Richard; Wareham, Jennifer; Schmeidler, James; Winters, Ken C.

    2016-01-01

    Research on samples of truant adolescents is limited, with little known about mental health problems among truant youths. This study provided an exploratory, multilevel examination of mental health problems for a sample of 300 truant adolescents. Confirmatory factor analysis indicated a single factor of multiple mental health problems at the…

  14. Spatial Analysis Of Human Capital Structures

    Directory of Open Access Journals (Sweden)

    Gajdos Artur

    2014-12-01

    Full Text Available The main purpose of this paper is to analyse the interdependence between labour productivity and the occupational structure of human capital in a spatial cross-section. Research indicates (see Fischer 2009 the possibility to assess the impact of the quality of human capital (measured by means of the level of education on labour productivity in a spatial cross-section.

  15. Using exploratory factor analysis in personality research: Best-practice recommendations

    Directory of Open Access Journals (Sweden)

    Sumaya Laher

    2010-03-01

    Full Text Available Orientation: Exploratory factor analysis is the method of choice with objective personality instruments, particularly to establish the construct validity and construct equivalence of trait-based instruments.Research purpose: This article presents more objective methods to determine the number of factors, most notably parallel analysis and Velicer’s minimum average partial (MAP. The benefits of rotation are also discussed. The article argues for more consistent use of Procrustes rotation and congruence coefficients in factor analytic studies.Motivation for the study: Exploratory factor analysis is often criticised for not being rigorous and objective enough in terms of the methods used to determine the number of factors, the rotations to be used and ultimately the validity of the factor structure.Research design, approach and method: The article adopts a theoretical stance to discuss the best-practice recommendations for factor analytic research in the field of psychology. Following this, an example located within personality assessment and using the NEO-PI-R specifically is presented. A total of 425 students at the University of the Witwatersrand completed the NEO-PI-R. These responses were subjected to a principal components analysis using varimax rotation. The rotated solution was subjected to a Procrustes rotation with Costa and McCrae’s (1992 matrix as the target matrix. Congruence coefficients were also computed.Main findings: The example indicates the use of the methods recommended in the article and demonstrates an objective way of determining the number of factors. It also provides an example of Procrustes rotation with coefficients of agreement as an indication of how factor analytic results may be presented more rigorously in local research.Practical/managerial implications: It is hoped that the recommendations in this article will have best-practice implications for both researchers and practitioners in the field who employ factor

  16. Old and New Ideas for Data Screening and Assumption Testing for Exploratory and Confirmatory Factor Analysis

    Science.gov (United States)

    Flora, David B.; LaBrish, Cathy; Chalmers, R. Philip

    2011-01-01

    We provide a basic review of the data screening and assumption testing issues relevant to exploratory and confirmatory factor analysis along with practical advice for conducting analyses that are sensitive to these concerns. Historically, factor analysis was developed for explaining the relationships among many continuous test scores, which led to the expression of the common factor model as a multivariate linear regression model with observed, continuous variables serving as dependent variables, and unobserved factors as the independent, explanatory variables. Thus, we begin our paper with a review of the assumptions for the common factor model and data screening issues as they pertain to the factor analysis of continuous observed variables. In particular, we describe how principles from regression diagnostics also apply to factor analysis. Next, because modern applications of factor analysis frequently involve the analysis of the individual items from a single test or questionnaire, an important focus of this paper is the factor analysis of items. Although the traditional linear factor model is well-suited to the analysis of continuously distributed variables, commonly used item types, including Likert-type items, almost always produce dichotomous or ordered categorical variables. We describe how relationships among such items are often not well described by product-moment correlations, which has clear ramifications for the traditional linear factor analysis. An alternative, non-linear factor analysis using polychoric correlations has become more readily available to applied researchers and thus more popular. Consequently, we also review the assumptions and data-screening issues involved in this method. Throughout the paper, we demonstrate these procedures using an historic data set of nine cognitive ability variables. PMID:22403561

  17. Remote access methods for exploratory data analysis and statistical modelling: Privacy-Preserving Analytics.

    Science.gov (United States)

    Sparks, Ross; Carter, Chris; Donnelly, John B; O'Keefe, Christine M; Duncan, Jodie; Keighley, Tim; McAullay, Damien

    2008-09-01

    This paper is concerned with the challenge of enabling the use of confidential or private data for research and policy analysis, while protecting confidentiality and privacy by reducing the risk of disclosure of sensitive information. Traditional solutions to the problem of reducing disclosure risk include releasing de-identified data and modifying data before release. In this paper we discuss the alternative approach of using a remote analysis server which does not enable any data release, but instead is designed to deliver useful results of user-specified statistical analyses with a low risk of disclosure. The techniques described in this paper enable a user to conduct a wide range of methods in exploratory data analysis, regression and survival analysis, while at the same time reducing the risk that the user can read or infer any individual record attribute value. We illustrate our methods with examples from biostatistics using publicly available data. We have implemented our techniques into a software demonstrator called Privacy-Preserving Analytics (PPA), via a web-based interface to the R software. We believe that PPA may provide an effective balance between the competing goals of providing useful information and reducing disclosure risk in some situations.

  18. Visualized Exploratory Spatiotemporal Analysis of Hand-Foot-Mouth Disease in Southern China

    Science.gov (United States)

    Huang, Ji-Xia; Wang, Jin-Feng; Li, Zhong-Jie; Wang, Yan; Lai, Sheng-Jie; Yang, Wei-Zhong

    2015-01-01

    Objectives In epidemiological research, major studies have focused on theoretical models; however, few methods of visual analysis have been used to display the patterns of disease distribution. Design For this study, a method combining the space-time cube (STC) with space-time scan statistics (STSS) was used to analyze the pattern of incidence of hand-foot-mouth disease (HFMD) in Guangdong Province from May 2008 to March 2009. In this research, STC was used to display the spatiotemporal pattern of incidence of HFMD, and STSS were used to detect the local aggregations of the disease. Setting The hand-foot-mouth disease data were obtained from Guangdong Province from May 2008 to March 2009, with a total of 68,130 cases. Results The STC analysis revealed a differential pattern of HFMD incidence among different months and cities and also showed that the population density and average precipitation are correlated with the incidence of HFMD. The STSS analysis revealed that the most likely aggregation includes the Shenzhen, Foshan and Dongguan populations, which are the most developed regions in Guangdong Province. Conclusion Both STC and STSS are efficient tools for the exploratory data analysis of disease transmission. STC clearly displays the spatiotemporal patterns of disease. Using the maximum likelihood ratio, the STSS model precisely locates the most likely aggregation. PMID:26605919

  19. Recent developments in spatial analysis spatial statistics, behavioural modelling, and computational intelligence

    CERN Document Server

    Getis, Arthur

    1997-01-01

    In recent years, spatial analysis has become an increasingly active field, as evidenced by the establishment of educational and research programs at many universities. Its popularity is due mainly to new technologies and the development of spatial data infrastructures. This book illustrates some recent developments in spatial analysis, behavioural modelling, and computational intelligence. World renown spatial analysts explain and demonstrate their new and insightful models and methods. The applications are in areas of societal interest such as the spread of infectious diseases, migration behaviour, and retail and agricultural location strategies. In addition, there is emphasis on the uses of new technologoies for the analysis of spatial data through the application of neural network concepts.

  20. MethVisual - visualization and exploratory statistical analysis of DNA methylation profiles from bisulfite sequencing.

    Science.gov (United States)

    Zackay, Arie; Steinhoff, Christine

    2010-12-15

    Exploration of DNA methylation and its impact on various regulatory mechanisms has become a very active field of research. Simultaneously there is an arising need for tools to process and analyse the data together with statistical investigation and visualisation. MethVisual is a new application that enables exploratory analysis and intuitive visualization of DNA methylation data as is typically generated by bisulfite sequencing. The package allows the import of DNA methylation sequences, aligns them and performs quality control comparison. It comprises basic analysis steps as lollipop visualization, co-occurrence display of methylation of neighbouring and distant CpG sites, summary statistics on methylation status, clustering and correspondence analysis. The package has been developed for methylation data but can be also used for other data types for which binary coding can be inferred. The application of the package, as well as a comparison to existing DNA methylation analysis tools and its workflow based on two datasets is presented in this paper. The R package MethVisual offers various analysis procedures for data that can be binarized, in particular for bisulfite sequenced methylation data. R/Bioconductor has become one of the most important environments for statistical analysis of various types of biological and medical data. Therefore, any data analysis within R that allows the integration of various data types as provided from different technological platforms is convenient. It is the first and so far the only specific package for DNA methylation analysis, in particular for bisulfite sequenced data available in R/Bioconductor enviroment. The package is available for free at http://methvisual.molgen.mpg.de/ and from the Bioconductor Consortium http://www.bioconductor.org.

  1. Investigation of the Factor Structure of the Comprehensive Test of Nonverbal Intelligence-Second Edition (CTONI-2) Using Exploratory Factor Analysis

    Science.gov (United States)

    McGill, Ryan J.

    2016-01-01

    The present study examined the structure of the Comprehensive Test of Nonverbal Intelligence-Second Edition (CTONI-2) normative sample using exploratory factor analysis, multiple factor extraction criteria, and higher-order exploratory factor analytic techniques that were not reported in the in the CTONI-2 "Examiner's Manual". Results…

  2. Exploratory Analysis of Carbon Dioxide Levels and Ultrasound Measures of the Eye During ISS Missions

    Science.gov (United States)

    Schaefer, C.; Young, M.; Mason, S.; Coble, C.; Wear, M. L.; Sargsyan, A.; Garcia, K.; Law. J.; Alexander, D.; Ryder, V. Myers; hide

    2016-01-01

    Carbon dioxide (CO2) levels on ISS have typically averaged 2.3 to 5.3mm Hg, with large fluctuations occurring over periods of hours and days. CO2 has effects on cerebral vascular tone, resulting in vasodilation and alteration of cerebral blood flow(CBF). Increased CBF leads to elevated intracranial pressure(ICP), which is a factor leading to visual disturbance, headaches, and other central nervous system symptoms. Ultrasound of the optic nerve provides a surrogate measurement of ICP. Inflight ultrasounds were implemented as an enhanced screening tool for the Visual Impairment/Intracranial Pressure (VIIP) Syndrome. This analysis examines the relationships between ambient CO2 levels on ISS and ultrasound measures of the eye in an effort to understand how CO2 may be associated with VIIP and to inform future analysis of inflight VIIP data. Results as shown in Figure2, there was a large timeframe where CO2 readings were removed due to sensor fault errors(see Limitations), from June 2011 to January 2012. After extensive cleaning of the CO2 data, metrics for all of the data were calculated (Table2). Preliminary analyses showed possible associations between variability measures of CO2 and AP diameter (Figure3),and average CO2 exposure and ONSD(Figure4). Adjustments for multiple comparisons were not made due to the exploratory nature of the analysis.

  3. Exploratory Visual Analysis of Statistical Results from Microarray Experiments Comparing High and Low Grade Glioma

    Directory of Open Access Journals (Sweden)

    Jason H. Moore

    2007-01-01

    Full Text Available The biological interpretation of gene expression microarray results is a daunting challenge. For complex diseases such as cancer, wherein the body of published research is extensive, the incorporation of expert knowledge provides a useful analytical framework. We have previously developed the Exploratory Visual Analysis (EVA software for exploring data analysis results in the context of annotation information about each gene, as well as biologically relevant groups of genes. We present EVA as a fl exible combination of statistics and biological annotation that provides a straightforward visual interface for the interpretation of microarray analyses of gene expression in the most commonly occurring class of brain tumors, glioma. We demonstrate the utility of EVA for the biological interpretation of statistical results by analyzing publicly available gene expression profi les of two important glial tumors. The results of a statistical comparison between 21 malignant, high-grade glioblastoma multiforme (GBM tumors and 19 indolent, low-grade pilocytic astrocytomas were analyzed using EVA. By using EVA to examine the results of a relatively simple statistical analysis, we were able to identify tumor class-specifi c gene expression patterns having both statistical and biological signifi cance. Our interactive analysis highlighted the potential importance of genes involved in cell cycle progression, proliferation, signaling, adhesion, migration, motility, and structure, as well as candidate gene loci on a region of Chromosome 7 that has been implicated in glioma. Because EVA does not require statistical or computational expertise and has the fl exibility to accommodate any type of statistical analysis, we anticipate EVA will prove a useful addition to the repertoire of computational methods used for microarray data analysis. EVA is available at no charge to academic users and can be found at http://www.epistasis.org.

  4. Using exploratory factor analysis in personality research: Best-practice recommendations

    Directory of Open Access Journals (Sweden)

    Sumaya Laher

    2010-11-01

    Research purpose: This article presents more objective methods to determine the number of factors, most notably parallel analysis and Velicer’s minimum average partial (MAP. The benefits of rotation are also discussed. The article argues for more consistent use of Procrustes rotation and congruence coefficients in factor analytic studies. Motivation for the study: Exploratory factor analysis is often criticised for not being rigorous and objective enough in terms of the methods used to determine the number of factors, the rotations to be used and ultimately the validity of the factor structure. Research design, approach and method: The article adopts a theoretical stance to discuss the best-practice recommendations for factor analytic research in the field of psychology. Following this, an example located within personality assessment and using the NEO-PI-R specifically is presented. A total of 425 students at the University of the Witwatersrand completed the NEO-PI-R. These responses were subjected to a principal components analysis using varimax rotation. The rotated solution was subjected to a Procrustes rotation with Costa and McCrae’s (1992 matrix as the target matrix. Congruence coefficients were also computed. Main findings: The example indicates the use of the methods recommended in the article and demonstrates an objective way of determining the number of factors. It also provides an example of Procrustes rotation with coefficients of agreement as an indication of how factor analytic results may be presented more rigorously in local research. Practical/managerial implications: It is hoped that the recommendations in this article will have best-practice implications for both researchers and practitioners in the field who employ factor analysis regularly. Contribution/value-add: This article will prove useful to all researchers employing factor analysis and has the potential to set the trend for better use of factor analysis in the South African context.

  5. Spatial epidemiological techniques in cholera mapping and analysis towards a local scale predictive modelling

    International Nuclear Information System (INIS)

    Rasam, A R A; Ghazali, R; Noor, A M M; Mohd, W M N W; Hamid, J R A; Bazlan, M J; Ahmad, N

    2014-01-01

    Cholera spatial epidemiology is the study of the spread and control of the disease spatial pattern and epidemics. Previous studies have shown that multi-factorial causation such as human behaviour, ecology and other infectious risk factors influence the disease outbreaks. Thus, understanding spatial pattern and possible interrelationship factors of the outbreaks are crucial to be explored an in-depth study. This study focuses on the integration of geographical information system (GIS) and epidemiological techniques in exploratory analyzing the cholera spatial pattern and distribution in the selected district of Sabah. Spatial Statistic and Pattern tools in ArcGIS and Microsoft Excel software were utilized to map and analyze the reported cholera cases and other data used. Meanwhile, cohort study in epidemiological technique was applied to investigate multiple outcomes of the disease exposure. The general spatial pattern of cholera was highly clustered showed the disease spread easily at a place or person to others especially 1500 meters from the infected person and locations. Although the cholera outbreaks in the districts are not critical, it could be endemic at the crowded areas, unhygienic environment, and close to contaminated water. It was also strongly believed that the coastal water of the study areas has possible relationship with the cholera transmission and phytoplankton bloom since the areas recorded higher cases. GIS demonstrates a vital spatial epidemiological technique in determining the distribution pattern and elucidating the hypotheses generating of the disease. The next research would be applying some advanced geo-analysis methods and other disease risk factors for producing a significant a local scale predictive risk model of the disease in Malaysia

  6. Spatial epidemiological techniques in cholera mapping and analysis towards a local scale predictive modelling

    Science.gov (United States)

    Rasam, A. R. A.; Ghazali, R.; Noor, A. M. M.; Mohd, W. M. N. W.; Hamid, J. R. A.; Bazlan, M. J.; Ahmad, N.

    2014-02-01

    Cholera spatial epidemiology is the study of the spread and control of the disease spatial pattern and epidemics. Previous studies have shown that multi-factorial causation such as human behaviour, ecology and other infectious risk factors influence the disease outbreaks. Thus, understanding spatial pattern and possible interrelationship factors of the outbreaks are crucial to be explored an in-depth study. This study focuses on the integration of geographical information system (GIS) and epidemiological techniques in exploratory analyzing the cholera spatial pattern and distribution in the selected district of Sabah. Spatial Statistic and Pattern tools in ArcGIS and Microsoft Excel software were utilized to map and analyze the reported cholera cases and other data used. Meanwhile, cohort study in epidemiological technique was applied to investigate multiple outcomes of the disease exposure. The general spatial pattern of cholera was highly clustered showed the disease spread easily at a place or person to others especially 1500 meters from the infected person and locations. Although the cholera outbreaks in the districts are not critical, it could be endemic at the crowded areas, unhygienic environment, and close to contaminated water. It was also strongly believed that the coastal water of the study areas has possible relationship with the cholera transmission and phytoplankton bloom since the areas recorded higher cases. GIS demonstrates a vital spatial epidemiological technique in determining the distribution pattern and elucidating the hypotheses generating of the disease. The next research would be applying some advanced geo-analysis methods and other disease risk factors for producing a significant a local scale predictive risk model of the disease in Malaysia.

  7. Spatial-Temporal Analysis of the Economic and Environmental Coordination Development Degree in Liaoning Province

    Directory of Open Access Journals (Sweden)

    Hui Wang

    2013-01-01

    Full Text Available This study selects 20 indices of economic and environmental conditions over 15 years (1996–2010 for 14 cities in Liaoning province, China. We calculate the economic score and environmental score of each city by processing 4200 data points through SPSS 16.0 and establish synthesis functions between the economy and the environment. For the time dimension, we study the temporal evolution of the economic and environmental coordination development degree . Based on Exploratory Spatial Data Analysis (ESDA techniques and using GeoDa, we calculate Moran's index of local spatial autocorrelation and explore the spatial distribution character of in Liaoning province through a LISA cluster map. As we found in the temporal dimension, the results show that of the 14 cities has been rising for 15 years and that increases year by year, which indicates that the economic and environmental coordination development condition has been improving from disorder to highly coordinated. A smaller gap between economic strength and environmental carrying capacity in Liaoning province exists, which means that economic development and environmental protection remain synchronized. In the spatial dimension, the highly coordinated cities have changed from a scattering to a concentration in the middle-south region of Liaoning province. Poorly coordinated cities are scattered in the northwestern region of Liaoning province.

  8. Application of exploratory data analysis methods for interpretation and classification of mass spectra

    International Nuclear Information System (INIS)

    Werther, W.

    1993-05-01

    Methods for computer-assisted elucidation of spectrum-structure relationships and classification in mass spectrometry have been developed. The core of these procedures are mapping methods from the field of multivariate exploratory data analysis. Mappings enable human visual exploration and interpretation of clustering and class separation. Spectral features derived by using spectral knowledge are applied instead of the peak heights in a mass spectrum. Comparison of the results of 11 different types of supervised and unsupervised mappings revealed three linear mappings to be well fitted for the task: the principal component mapping (PCA), the optimal discriminant plane and a variant of the partial-least-squares mapping (PLS). The common advantages of these mappings are twofold: they are all applied as orthogonal rotations and the mass spectral reasons for clustering of objects and separation of classes can be detected by interpretation of the factor loadings. PCA mappings are sometimes dominated by parts of the spectral data structure, which have no structural meaning. Therefore a PLS-substructure-mapping based on binary structural descriptors as dependent variables has been developed, which is advantageous for the investigation of spectrum-structure-relationships. A statistical substructure analysis is applied to recognize regions in the mapping, which contain similar chemical structures. A FORTRAN program (EDAS-MS) has been implemented on a VAX computer for the application of the methods. (author)

  9. Types of avoidance in hair-pulling disorder (trichotillomania): An exploratory and confirmatory analysis.

    Science.gov (United States)

    Slikboer, Reneta; Castle, David J; Nedeljkovic, Maja; Rossell, Susan L

    2018-03-01

    Hair-pulling disorder (HPD) or Trichotillomania is a complex disorder with frequent relapses. Avoidance has been highlighted as an important behavioural feature in HPD. To improve our understanding of avoidance, two studies were conducted to identify the types of avoidance that may be experienced by those who pull hair. Internet questionnaires were used to collect data. Data from study one was split into two subsets. An exploratory factor analysis was conducted to identify the different types of avoidance experienced by those reporting symptoms of hair pulling (subset one, n = 278), followed by a confirmatory factor analysis (subset two, n = 295). In study two a MANOVA was conducted (n = 300) to examine whether levels of avoidance differed between controls and those with hair pulling symptoms. Participants with hair pulling symptoms had greater levels of avoidance on each of the five types: 'Avoidance of non-social goals', 'Self-concealment', 'Behavioural social avoidance', 'Avoidance of relationship problem solving' and 'Avoidance of thinking about the future'. These data expand on the current literature, which has predominantly focused on experiential avoidance. Future research will need to validate these findings in a clinical group. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Seizure Self-Efficacy Scale for Children with Epilepsy: Confirmatory and Exploratory Factor Analysis

    Directory of Open Access Journals (Sweden)

    Şerife Tutar Güven

    2017-12-01

    Full Text Available Aim: In the past few years, the concept of self-efficacy in children with epilepsy has become increasingly important. This study aimed to analyze the psychometric aspects of the Turkish version of the Seizure Self-Efficacy Scale for Children. Materials and Methods: This is a cross-sectional survey. The study data were collected using the Seizure Self-Efficacy Scale for Children and Child Introduction Form. The study sample included 166 children who were between 9 and 17 years of age. The authors assessed the reliability and construct validity of the study data using exploratory and confirmatory factor analyses (CFA. Results: The original model was not confirmed by the CFA. The analysis tool included 15 items in two factors. Reliability analysis showed that the two factors were acceptable and valid. The tool was valid and reliable for measuring the self-efficacy of epileptic children. The factor structure was derived from and confirmed by the original tool. It was found that the Turkish version of the modified Seizure Self-Efficacy Scale for Children had excellent satisfactory psychometric aspects for a Turkish population. Conclusion: Health professionals can present a more effective drug process and nursing care by identifying and assessing seizure self-efficacy levels in children with epilepsy, and they can make a positive contribution to disease management and the way the child deals with the disease.

  11. Ingredient classification according to the digestible amino acid profile: an exploratory analysis

    Directory of Open Access Journals (Sweden)

    DE Faria Filho

    2005-09-01

    Full Text Available This study aimed: 1 to classify ingredients according to the digestible amino acid (AA profile; 2 to determine ingredients with AA profile closer to the ideal for broiler chickens; and 3 to compare digestible AA profiles from simulated diets with the ideal protein profile. The digestible AA levels of 30 ingredients were compiled from the literature and presented as percentages of lysine according to the ideal protein concept. Cluster and principal component analyses (exploratory analyses were used to compose and describe groups of ingredients according to AA profiles. Four ingredient groups were identified by cluster analysis, and the classification of the ingredients within each of these groups was obtained from a principal component analysis, showing 11 classes of ingredients with similar digestible AA profiles. The ingredients with AA profiles closer to the ideal protein were meat and bone meal 45, fish meal 60 and wheat germ meal, all of them constituting Class 1; the ingredients from the other classes gradually diverged from the ideal protein. Soybean meal, which is the main protein source for poultry, showed good AA balance since it was included in Class 3. On the contrary, corn, which is the main energy source in poultry diets, was classified in Class 8. Dietary AA profiles were improved when corn and/or soybean meal were partially or totally replaced in the simulations by ingredients with better AA balance.

  12. Strategic Decision-Making: Research Mapping from Exploratory Factor Analysis and Multidimensional Scaling

    Directory of Open Access Journals (Sweden)

    Ivano Ribeiro

    2017-04-01

    Full Text Available To understand the connection between authors, concepts and theories that address strategic decision-making, in this article the citations and co-citations of works published up to 2014 were analyzed. The sample consists of 489 articles published in international periodicals included in the Web of Science-ISI Web of Knowledge database. The search was conducted using key words that enabled the identification of the highest possible number of articles on the subject in question. Through Multidimensional Scaling (MDS and Exploratory Factor Analysis (EFA, the conceptual and theoretical relationships involved in these studies were identified. The results show that from 1980 to 2014 three different factors are highlighted: the first has to do with studies on conflict; the second factor is the Top Management Team (TMT and decision-making; and the third is related to processes. More recently (2013-2014, studies on strategic decision-making are converging towards analysis of conflict and process, composition and control, with Upper Echelon Theory being maintained as the central theory in these studies. This finding is the main contribution of this article.

  13. Residual analysis for spatial point processes

    DEFF Research Database (Denmark)

    Baddeley, A.; Turner, R.; Møller, Jesper

    process. Residuals are ascribed to locations in the empty background, as well as to data points of the point pattern. We obtain variance formulae, and study standardised residuals. There is also an analogy between our spatial residuals and the usual residuals for (non-spatial) generalised linear models...... or covariate effects. Q-Q plots of the residuals are effective in diagnosing interpoint interaction. Some existing ad hoc statistics of point patterns (quadrat counts, scan statistic, kernel smoothed intensity, Berman's diagnostic) are recovered as special cases....

  14. Mutation-related differences in exploratory, spatial and depressive-like behavior in pcd and Lurcher cerebellar mutant mice

    Directory of Open Access Journals (Sweden)

    Jan eTuma

    2015-05-01

    Full Text Available The cerebellum is not only essential for motor coordination but is also involved in cognitive and affective processes. These functions of the cerebellum and mechanisms of their disorders in cerebellar injury are not completely understood. There is a wide spectrum of cerebellar mutant mice which are used as models of hereditary cerebellar degenerations. Nevertheless, they differ in pathogenesis of manifestation of the particular mutation and also in the strain background. The aim of this work was to compare spatial navigation, learning and memory in pcd and Lurcher mice, two of the most frequently used cerebellar mutants. The mice were tested in the open field for exploration behavior, in the Morris water maze with visible as well as reversal hidden platform tasks and in the forced swimming test for motivation assessment. Lurcher mice showed different space exploration activity in the open field and a lower tendency to depressive-like behavior in the forced swimming test compared with pcd mice. Severe deficit of spatial navigation was shown in both cerebellar mutants. However, the overall performance of Lurcher mice was better than that of pcd mutants. Lurcher mice showed the ability of visual guidance despite difficulties with the direct swim towards a goal. In the probe trial test, Lurcher mice preferred the visible platform rather than the more recent localization of the hidden goal.

  15. Exploratory factor analysis of the Research and Development Culture Index among qualified nurses.

    Science.gov (United States)

    Watson, Bill; Clarke, Charlotte; Swallow, Vera; Forster, Stewart

    2005-10-01

    This paper presents the exploratory factor analysis of a rating instrument for assessing the strength of organizational Research and Development (R&D) culture. Despite nursing's limited research capacity, the discipline is capitalizing upon opportunities to become involved in research and is making strong progress. Within the context of the debate on nursing research capacity, the R&D Culture Index was developed as a means of appraising R&D culture within health care organizations. Factor analysis was carried out on data collected from 485 nursing staff. The method of extraction was Principal Components Analysis with oblique rotation. The Index was developed from the findings of qualitative research conducted with NHS staff. Eighteen items, encompassing the main themes from the data, were initially included in the Index. This pilot instrument was distributed to nursing staff within three different types of NHS Trust. Factor analysis resulted in rejection of two items and the analysis was repeated using the remaining 16 items. Three latent factors were extracted accounting for 58.0% of the variance in the data. The factors were: R&D Support, describing the perceived support within the working environment for R&D activity; Personal R&D Skills and Aptitude, describing an individual's perception of their ability towards R&D activity; and Personal R&D Intention, describing an individual's willingness to engage in R&D activity. Each factor had good internal reliability, as did the overall index. The R&D Culture Index provides an efficient means of assessing the strength of an organization's R&D culture in a way that captures the role of the individual practitioner and the organizational environment. These findings suggest that the continuing promotion of R&D within health care organizations is dependent upon a multi-faceted approach that addresses the learning needs of the organization as well as those of the individual practitioners.

  16. Research progress and hotspot analysis of spatial interpolation

    Science.gov (United States)

    Jia, Li-juan; Zheng, Xin-qi; Miao, Jin-li

    2018-02-01

    In this paper, the literatures related to spatial interpolation between 1982 and 2017, which are included in the Web of Science core database, are used as data sources, and the visualization analysis is carried out according to the co-country network, co-category network, co-citation network, keywords co-occurrence network. It is found that spatial interpolation has experienced three stages: slow development, steady development and rapid development; The cross effect between 11 clustering groups, the main convergence of spatial interpolation theory research, the practical application and case study of spatial interpolation and research on the accuracy and efficiency of spatial interpolation. Finding the optimal spatial interpolation is the frontier and hot spot of the research. Spatial interpolation research has formed a theoretical basis and research system framework, interdisciplinary strong, is widely used in various fields.

  17. Second order analysis for spatial Hawkes processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Torrisi, Giovanni Luca

    We derive summary statistics for stationary Hawkes processes which can be considered as spatial versions of classical Hawkes processes. Particularly, we derive the intensity, the pair correlation function and the Bartlett spectrum. Our results for Gaussian fertility rates and the extension...... to marked Hawkes processes are discussed....

  18. Spatial information analysis of chemotactic trajectories.

    Science.gov (United States)

    Hoh, Jan H; Heinz, William F; Werbin, Jeffrey L

    2012-03-01

    During bacterial chemotaxis, a cell acquires information about its environment by sampling changes in the local concentration of a chemoattractant, and then uses that information to bias its motion relative to the source of the chemoattractant. The trajectory of a chemotaxing bacteria is thus a spatial manifestation of the information gathered by the cell. Here we show that a recently developed approach for computing spatial information using Fourier coefficient probabilities, the k-space information (kSI), can be used to quantify the information in such trajectories. The kSI is shown to capture expected responses to gradients of a chemoattractant. We then extend the k-space approach by developing an experimental probability distribution (EPD) that is computed from chemotactic trajectories collected under a reference condition. The EPD accounts for connectivity and other constraints that the nature of the trajectories imposes on the k-space computation. The EPD is used to compute the spatial information from any trajectory of interest, relative to the reference condition. The EPD-based spatial information also captures the expected responses to gradients of a chemoattractant, although the results differ in significant ways from the original kSI computation. In addition, the entropy calculated from the EPD provides a useful measure of trajectory space. The methods developed are highly general, and can be applied to a wide range of other trajectory types as well as non-trajectory data.

  19. Visuo-spatial orienting during active exploratory behavior: Processing of task-related and stimulus-related signals.

    Science.gov (United States)

    Macaluso, Emiliano; Ogawa, Akitoshi

    2017-09-05

    Functional imaging studies have associated dorsal and ventral fronto-parietal regions with the control of visuo-spatial attention. Previous studies demonstrated that the activity of both the dorsal and the ventral attention systems can be modulated by many different factors, related both to the stimuli and the task. However, the vast majority of this work utilized stereotyped paradigms with simple and repeated stimuli. This is at odd with any real life situation that instead involve complex combinations of different types of co-occurring signals, thus raising the question of the ecological significance of the previous findings. Here we investigated how the brain responds to task-related and stimulus-related signals using an innovative approach that involved active exploration of a virtual environment. This enabled us to study visuo-spatial orienting in conditions entailing a dynamic and coherent flow of visual signals, to some extent analogous to real life situations. The environment comprised colored/textured spheres and cubes, which allowed us to implement a standard feature-conjunction search task (task-related signals), and included one physically salient object that served to track the processing of stimulus-related signals. The imaging analyses showed that the posterior parietal cortex (PPC) activated when the participants' gaze was directed towards the salient-objects. By contrast, the right inferior partial cortex was associated with the processing of the target-objects and of distractors that shared the target-color and shape, consistent with goal-directed template-matching operations. The study highlights the possibility of combining measures of gaze orienting and functional imaging to investigate the processing of different types of signals during active behavior in complex environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Aging Chart: a community resource for rapid exploratory pathway analysis of age-related processes.

    Science.gov (United States)

    Moskalev, Alexey; Zhikrivetskaya, Svetlana; Shaposhnikov, Mikhail; Dobrovolskaya, Evgenia; Gurinovich, Roman; Kuryan, Oleg; Pashuk, Aleksandr; Jellen, Leslie C; Aliper, Alex; Peregudov, Alex; Zhavoronkov, Alex

    2016-01-04

    Aging research is a multi-disciplinary field encompassing knowledge from many areas of basic, applied and clinical research. Age-related processes occur on molecular, cellular, tissue, organ, system, organismal and even psychological levels, trigger the onset of multiple debilitating diseases and lead to a loss of function, and there is a need for a unified knowledge repository designed to track, analyze and visualize the cause and effect relationships and interactions between the many elements and processes on all levels. Aging Chart (http://agingchart.org/) is a new, community-curated collection of aging pathways and knowledge that provides a platform for rapid exploratory analysis. Building on an initial content base constructed by a team of experts from peer-reviewed literature, users can integrate new data into biological pathway diagrams for a visible, intuitive, top-down framework of aging processes that fosters knowledge-building and collaboration. As the body of knowledge in aging research is rapidly increasing, an open visual encyclopedia of aging processes will be useful to both the new entrants and experts in the field. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  1. Exploratory analysis of spatiotemporal patterns of cellular automata by clustering compressibility

    Science.gov (United States)

    Emmert-Streib, Frank

    2010-02-01

    In this paper we study the classification of spatiotemporal pattern of one-dimensional cellular automata (CA) whereas the classification comprises CA rules including their initial conditions. We propose an exploratory analysis method based on the normalized compression distance (NCD) of spatiotemporal patterns which is used as dissimilarity measure for a hierarchical clustering. Our approach is different with respect to the following points. First, the classification of spatiotemporal pattern is comparative because the NCD evaluates explicitly the difference of compressibility among two objects, e.g., strings corresponding to spatiotemporal patterns. This is in contrast to all other measures applied so far in a similar context because they are essentially univariate. Second, Kolmogorov complexity, which underlies the NCD, was used in the classification of CA with respect to their spatiotemporal pattern. Third, our method is semiautomatic allowing us to investigate hundreds or thousands of CA rules or initial conditions simultaneously to gain insights into their organizational structure. Our numerical results are not only plausible confirming previous classification attempts but also shed light on the intricate influence of random initial conditions on the classification results.

  2. Global Search Trends of Oral Problems using Google Trends from 2004 to 2016: An Exploratory Analysis.

    Science.gov (United States)

    Patthi, Basavaraj; Kumar, Jishnu Krishna; Singla, Ashish; Gupta, Ritu; Prasad, Monika; Ali, Irfan; Dhama, Kuldeep; Niraj, Lav Kumar

    2017-09-01

    Oral diseases are pandemic cause of morbidity with widespread geographic distribution. This technology based era has brought about easy knowledge transfer than traditional dependency on information obtained from family doctors. Hence, harvesting this system of trends can aid in oral disease quantification. To conduct an exploratory analysis of the changes in internet search volumes of oral diseases by using Google Trends © (GT © ). GT © were utilized to provide real world facts based on search terms related to categories, interest by region and interest over time. Time period chosen was from January 2004 to December 2016. Five different search terms were explored and compared based on the highest relative search volumes along with comma separated value files to obtain an insight into highest search traffic. The search volume measured over the time span noted the term "Dental caries" to be the most searched in Japan, "Gingivitis" in Jordan, "Oral Cancer" in Taiwan, "No Teeth" in Australia, "HIV symptoms" in Zimbabwe, "Broken Teeth" in United Kingdom, "Cleft palate" in Philippines, "Toothache" in Indonesia and the comparison of top five searched terms provided the "Gingivitis" with highest search volume. The results from the present study offers an insight into a competent tool that can analyse and compare oral diseases over time. The trend research platform can be used on emerging diseases and their drift in geographic population with great acumen. This tool can be utilized in forecasting, modulating marketing strategies and planning disability limitation techniques.

  3. Explaining cross-national variations in tax morality in the European Union: an exploratory analysis

    Directory of Open Access Journals (Sweden)

    Colin C. Williams

    2014-06-01

    Full Text Available The aim of this paper is to conduct an exploratory analysis of factors that might explain the cross-national variations in the level tax morality across the European Union. In order to do this, three competing explanations for the cross-national variations in tax morality will be evaluated which variously view lower levels of tax morality to be a result of either: under-development (a modernisation explanation; high taxes, state corruption and too much state interference (a neo-liberal explanation, or too little state redistribution and intervention to protect citizens (a structuralist explanation. Evaluating the cross-national variations in tax morality reported in a 2007 Eurobarometer survey using multilevel econometric techniques, the finding is that the tax morality of a baseline European citizen is higher in more developed and less corrupt nations and in countries with higher levels of taxation, social protection and redistribution. The outcome is a call for a synthesis of the three explanations in the form of a new neo-modernisation explanation which, contrary to neo-liberal discourse, argues that developed nations with higher levels of taxation, greater levels of social protection and higher levels of redistribution have higher levels of tax morality. The tentative policy implications are then discussed.

  4. Exploratory factor analysis for differentiating sensory and mechanical variables related to muscle-tendon unit elongation

    Directory of Open Access Journals (Sweden)

    Mauro H. Chagas

    2016-01-01

    Full Text Available ABSTRACT Background Stretching exercises are able to promote adaptations in the muscle-tendon unit (MTU, which can be tested through physiological and biomechanical variables. Identifying the key variables in MTU adaptations is crucial to improvements in training. Objective To perform an exploratory factor analysis (EFA involving the variables often used to evaluate the response of the MTU to stretching exercises. Method Maximum joint range of motion (ROMMAX, ROM at first sensation of stretching (FSTROM, peak torque (torqueMAX, passive stiffness, normalized stiffness, passive energy, and normalized energy were investigated in 36 participants during passive knee extension on an isokinetic dynamometer. Stiffness and energy values were normalized by the muscle cross-sectional area and their passive mode assured by monitoring the EMG activity. Results EFA revealed two major factors that explained 89.68% of the total variance: 53.13% was explained by the variables torqueMAX, passive stiffness, normalized stiffness, passive energy, and normalized energy, whereas the remaining 36.55% was explained by the variables ROMMAX and FSTROM. Conclusion This result supports the literature wherein two main hypotheses (mechanical and sensory theories have been suggested to describe the adaptations of the MTU to stretching exercises. Contrary to some studies, in the present investigation torqueMAX was significantly correlated with the variables of the mechanical theory rather than those of the sensory theory. Therefore, a new approach was proposed to explain the behavior of the torqueMAX during stretching exercises.

  5. Improving Your Exploratory Factor Analysis for Ordinal Data: A Demonstration Using FACTOR

    Directory of Open Access Journals (Sweden)

    James Baglin

    2014-06-01

    Full Text Available Exploratory factor analysis (EFA methods are used extensively in the field of assessment and evaluation. Due to EFA's widespread use, common methods and practices have come under close scrutiny. A substantial body of literature has been compiled highlighting problems with many of the methods and practices used in EFA, and, in response, many guidelines have been proposed with the aim to improve application. Unfortunately, implementing recommended EFA practices has been restricted by the range of options available in commercial statistical packages and, perhaps, due to an absence of clear, practical - how-to' demonstrations. Consequently, this article describes the application of methods recommended to get the most out of your EFA. The article focuses on dealing with the common situation of analysing ordinal data as derived from Likert-type scales. These methods are demonstrated using the free, stand-alone, easy-to-use and powerful EFA package FACTOR (http://psico.fcep.urv.es/utilitats/factor/, Lorenzo-Seva & Ferrando, 2006. The demonstration applies the recommended techniques using an accompanying dataset, based on the Big 5 personality test. The outcomes obtained by the EFA using the recommended procedures through FACTOR are compared to the default techniques currently available in SPSS.

  6. Spatial analysis of various multiplex cinema types

    Directory of Open Access Journals (Sweden)

    Young-Seo Park

    2016-03-01

    Full Text Available This study identifies the spatial characteristics and relationships of each used space according to the multiplex type. In this study, multiplexes are classified according to screen rooms and circulation systems, and each used space is quantitatively analyzed. The multiplex type based on screen rooms and moving line systems influences the relationship and characteristics of each used space in various ways. In particular, the structure of the used space of multiplexes has a significant effect on profit generation and audience convenience.

  7. The development of an evaluation tool to measure nursing core curriculum teaching effectiveness: an exploratory factor analysis.

    Science.gov (United States)

    Chang, Shu-Fang

    2012-09-01

    There have been few evidence-based assessments of nursing education core curricula. To conduct such assessments effectively, researchers need an objective professional tool that addresses the principal competencies of the nursing profession. The aim of this study was to develop a preliminary assessment tool to improve teaching effectiveness in nursing core curricula. This study was divided into four stages: (a) initial questionnaire content proposal, (b) expert validation, (c) random sampling, and (d) item and exploratory factor analysis. We used exploratory factor analysis to analyze three factors, namely (a) learning preparation, (b) advancement of competence, and (c) learning evaluation. These three factors explained, respectively, 43.1%, 12.9%, and 7.5% of total variance; the three together explained 63.5% of total variance. Overall questionnaire reliability was .904. All correlation coefficients displayed moderately positive relationships among subscales. The assessment tool developed in this study showed reliability and validity in the evaluation of teaching outcomes for nursing core curricula.

  8. Exploratory graph analysis: A new approach for estimating the number of dimensions in psychological research.

    Science.gov (United States)

    Golino, Hudson F; Epskamp, Sacha

    2017-01-01

    The estimation of the correct number of dimensions is a long-standing problem in psychometrics. Several methods have been proposed, such as parallel analysis (PA), Kaiser-Guttman's eigenvalue-greater-than-one rule, multiple average partial procedure (MAP), the maximum-likelihood approaches that use fit indexes as BIC and EBIC and the less used and studied approach called very simple structure (VSS). In the present paper a new approach to estimate the number of dimensions will be introduced and compared via simulation to the traditional techniques pointed above. The approach proposed in the current paper is called exploratory graph analysis (EGA), since it is based on the graphical lasso with the regularization parameter specified using EBIC. The number of dimensions is verified using the walktrap, a random walk algorithm used to identify communities in networks. In total, 32,000 data sets were simulated to fit known factor structures, with the data sets varying across different criteria: number of factors (2 and 4), number of items (5 and 10), sample size (100, 500, 1000 and 5000) and correlation between factors (orthogonal, .20, .50 and .70), resulting in 64 different conditions. For each condition, 500 data sets were simulated using lavaan. The result shows that the EGA performs comparable to parallel analysis, EBIC, eBIC and to Kaiser-Guttman rule in a number of situations, especially when the number of factors was two. However, EGA was the only technique able to correctly estimate the number of dimensions in the four-factor structure when the correlation between factors were .7, showing an accuracy of 100% for a sample size of 5,000 observations. Finally, the EGA was used to estimate the number of factors in a real dataset, in order to compare its performance with the other six techniques tested in the simulation study.

  9. Exploratory analysis of chromatographic fingerprints to distinguish rhizoma Chuanxiong and rhizoma Ligustici.

    Science.gov (United States)

    Alaerts, G; Merino-Arévalo, M; Dumarey, M; Dejaegher, B; Noppe, N; Matthijs, N; Smeyers-Verbeke, J; Vander Heyden, Y

    2010-12-03

    Identification and quality control of products of natural origin, used for preventive and therapeutical goals, is required by regulating authorities, as the World Health Organization. This study focuses on the identification and distinction of the rhizomes from two Chinese herbs, rhizoma Chuanxiong (from Ligusticum chuanxiong Hort.) and rhizoma Ligustici (from Ligusticum jeholense Nakai et Kitag), by chromatographic fingerprints. A second goal is using the fingerprints to assay ferulic acid, as its concentration provides an additional differentiation feature. Several extraction methods were tested, to obtain the highest number of peaks in the fingerprints. The best results were found using 76:19:5 (v/v/v) methanol/water/formic acid as solvent and extracting the pulverized material on a shaking bath for 15 min. Then fingerprint optimization was done. Most information about the herbs, i.e. the highest number of peaks, was observed on a Hypersil ODS column (250 mm × 4.6 mm ID, 5 μm), 1.0% acetic acid in the mobile phase and employing within 50 min linear gradient elution from 5:95 (v/v) to 95:5 (v/v) acetonitrile/water. The final fingerprints were able to distinguish rhizoma Chuanxiong and Ligustici, based on correlation coefficients combined with exploratory data analysis. The distinction was visualized using Principal Component Analysis, Projection Pursuit and Hierarchical Clustering Analysis techniques. Quantification of ferulic acid was possible in the fingerprints of both rhizomes. The time-different intermediate precisions of the fingerprints and of the ferulic acid quantification were shown to be acceptable. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. Spatial Analysis of Health Facilities in Suleja, Niger State, Nigeria ...

    African Journals Online (AJOL)

    Spatial Analysis of Health Facilities in Suleja, Niger State, Nigeria. ... Ethiopian Journal of Environmental Studies and Management ... Despite government policies on the provision and delivery of healthcare to all, the spatial distribution of such health facilities are subject to a number of social and commercial influences that ...

  11. Rapid Benefit Indicators (RBI) Spatial Analysis Tools - Manual

    Science.gov (United States)

    The Rapid Benefit Indicators (RBI) approach consists of five steps and is outlined in Assessing the Benefits of Wetland Restoration - A Rapid Benefits Indicators Approach for Decision Makers. This spatial analysis tool is intended to be used to analyze existing spatial informatio...

  12. Spatial analysis of the electrical energy demand in Greece

    International Nuclear Information System (INIS)

    Tyralis, Hristos; Mamassis, Nikos; Photis, Yorgos N.

    2017-01-01

    The Electrical Energy Demand (EED) of the agricultural, commercial and industrial sector in Greece, as well as its use for domestic activities, public and municipal authorities and street lighting are analysed spatially using Geographical Information System and spatial statistical methods. The analysis is performed on data which span from 2008 to 2012 and have annual temporal resolution and spatial resolution down to the NUTS (Nomenclature of Territorial Units for Statistics) level 3. The aim is to identify spatial patterns of the EED and its transformations such as the ratios of the EED to socioeconomic variables, i.e. the population, the total area, the population density and the Gross Domestic Product (GDP). Based on the analysis, Greece is divided in five regions, each one with a different development model, i.e. Attica and Thessaloniki which are two heavily populated major poles, Thessaly and Central Greece which form a connected geographical region with important agricultural and industrial sector, the islands and some coastal areas which are characterized by an important commercial sector and the rest Greek areas. The spatial patterns can provide additional information for policy decision about the electrical energy management and better representation of the regional socioeconomic conditions. - Highlights: • We visualize spatially the Electrical Energy Demand (EED) in Greece. • We apply spatial analysis methods to the EED data. • Spatial patterns of the EED are identified. • Greece is classified in five distinct groups, based on the analysis. • The results can be used for optimal planning of the electric system.

  13. Modifying the Autism Spectrum Rating Scale (6?18?years) to a Chinese Context: An Exploratory Factor Analysis

    OpenAIRE

    Zhou, Hao; Zhang, Lili; Luo, Xuerong; Wu, Lijie; Zou, Xiaobing; Xia, Kun; Wang, Yimin; Xu, Xiu; Ge, Xiaoling; Jiang, Yong-Hui; Fombonne, Eric; Yan, Weili; Wang, Yi

    2017-01-01

    The purpose of this study was to explore the psychometric properties of the Chinese version of the autism spectrum rating scale (ASRS). We recruited 1,625 community-based children and 211 autism spectrum disorder (ASD) cases from 4 sites, and the parents of all participants completed the Chinese version of the ASRS. A robust weighted least squares means and variance adjusted estimator was used for exploratory factor analysis. The 3-factor structure included 59 items suitable for the current s...

  14. Spatial analysis of hemorrhagic fever with renal syndrome in China

    Directory of Open Access Journals (Sweden)

    Yang Hong

    2006-04-01

    Full Text Available Abstract Background Hemorrhagic fever with renal syndrome (HFRS is endemic in many provinces with high incidence in mainland China, although integrated intervention measures including rodent control, environment management and vaccination have been implemented for over ten years. In this study, we conducted a geographic information system (GIS-based spatial analysis on distribution of HFRS cases for the whole country with an objective to inform priority areas for public health planning and resource allocation. Methods Annualized average incidence at a county level was calculated using HFRS cases reported during 1994–1998 in mainland China. GIS-based spatial analyses were conducted to detect spatial autocorrelation and clusters of HFRS incidence at the county level throughout the country. Results Spatial distribution of HFRS cases in mainland China from 1994 to 1998 was mapped at county level in the aspects of crude incidence, excess hazard and spatial smoothed incidence. The spatial distribution of HFRS cases was nonrandom and clustered with a Moran's I = 0.5044 (p = 0.001. Spatial cluster analyses suggested that 26 and 39 areas were at increased risks of HFRS (p Conclusion The application of GIS, together with spatial statistical techniques, provide a means to quantify explicit HFRS risks and to further identify environmental factors responsible for the increasing disease risks. We demonstrate a new perspective of integrating such spatial analysis tools into the epidemiologic study and risk assessment of HFRS.

  15. Exploratory Use of Decision Tree Analysis in Classification of Outcome in Hypoxic–Ischemic Brain Injury

    Directory of Open Access Journals (Sweden)

    Thanh G. Phan

    2018-03-01

    Full Text Available BackgroundPrognostication following hypoxic ischemic encephalopathy (brain injury is important for clinical management. The aim of this exploratory study is to use a decision tree model to find clinical and MRI associates of severe disability and death in this condition. We evaluate clinical model and then the added value of MRI data.MethodThe inclusion criteria were as follows: age ≥17 years, cardio-respiratory arrest, and coma on admission (2003–2011. Decision tree analysis was used to find clinical [Glasgow Coma Score (GCS, features about cardiac arrest, therapeutic hypothermia, age, and sex] and MRI (infarct volume associates of severe disability and death. We used the area under the ROC (auROC to determine accuracy of model. There were 41 (63.7% males patients having MRI imaging with the average age 51.5 ± 18.9 years old. The decision trees showed that infarct volume and age were important factors for discrimination between mild to moderate disability and severe disability and death at day 0 and day 2. The auROC for this model was 0.94 (95% CI 0.82–1.00. At day 7, GCS value was the only predictor; the auROC was 0.96 (95% CI 0.86–1.00.ConclusionOur findings provide proof of concept for further exploration of the role of MR imaging and decision tree analysis in the early prognostication of hypoxic ischemic brain injury.

  16. System Learning via Exploratory Data Analysis: Seeing Both the Forest and the Trees

    Science.gov (United States)

    Habash Krause, L.

    2014-12-01

    As the amount of observational Earth and Space Science data grows, so does the need for learning and employing data analysis techniques that can extract meaningful information from those data. Space-based and ground-based data sources from all over the world are used to inform Earth and Space environment models. However, with such a large amount of data comes a need to organize those data in a way such that trends within the data are easily discernible. This can be tricky due to the interaction between physical processes that lead to partial correlation of variables or multiple interacting sources of causality. With the suite of Exploratory Data Analysis (EDA) data mining codes available at MSFC, we have the capability to analyze large, complex data sets and quantitatively identify fundamentally independent effects from consequential or derived effects. We have used these techniques to examine the accuracy of ionospheric climate models with respect to trends in ionospheric parameters and space weather effects. In particular, these codes have been used to 1) Provide summary "at-a-glance" surveys of large data sets through categorization and/or evolution over time to identify trends, distribution shapes, and outliers, 2) Discern the underlying "latent" variables which share common sources of causality, and 3) Establish a new set of basis vectors by computing Empirical Orthogonal Functions (EOFs) which represent the maximum amount of variance for each principal component. Some of these techniques are easily implemented in the classroom using standard MATLAB functions, some of the more advanced applications require the statistical toolbox, and applications to unique situations require more sophisiticated levels of programming. This paper will present an overview of the range of tools available and how they might be used for a variety of time series Earth and Space Science data sets. Examples of feature recognition from both 1D and 2D (e.g. imagery) time series data

  17. The In-Out dispositional affective style questionnaire (IN-OUT DASQ: an exploratory factorial analysis

    Directory of Open Access Journals (Sweden)

    Viridiana eMazzola

    2014-09-01

    Full Text Available The issue of individual differences has always been an important area of research in psychology and, more recently, neuroimaging. A major source of interindividual variability stems from differences in basic affective dispositions. In order to make a contribution to this field of research, we have developed a new type of assessment - the In-Out Dispositional Affective Style Questionnaire (IN-OUT DASQ - to measure the proneness between two different ways of feeling situated: a predominantly body-bound one in the case of the inward tendency and an externally anchored one in the case of the outward tendency (Arciero and Bondolfi, 2009. The IN-OUT DASQ contains 2 scales of 7 items each, Self-centric engagement (SCE and Other-centric engagement (OCE, as a disposition index for inwardness and outwardness respectively. The exploratory factor analysis in sample 1 (n= 292 confirmed a two-factor solution. Confirmatory factor analysis in sample 2 (n= 300 showed the good fit of this two-factor model. Next, we examined construct validity also investigating the correlations between the IN-OUT DASQ, the Big Five Questionnaire and the Positive and Negative Affect Schedule in sample 3 (n=153. The SCE and OCE scales had robust internal consistency and reliability, and therefore the capacity to discriminate higher inward and outward participants was stronger in SCE. Although further validation research is required, the present study suggests the IN-OUT DASQ has the potential to be a measurement tool for detecting individual differences in social behavior and social affective neuroscience.

  18. An exploratory wastewater analysis study of drug use in Auckland, New Zealand.

    Science.gov (United States)

    Lai, Foon Yin; Wilkins, Chris; Thai, Phong; Mueller, Jochen F

    2017-09-01

    New Zealand is considered to have unusual drug use patterns by international standards. However, this understanding has largely been obtained from social surveys where respondents self-report use. The aim of this paper is to conduct the first wastewater study of drug use in Auckland. Wastewater sampling was completed from 2 May to 18 July 2014 at 2 Auckland wastewater treatment plants which service 1.3 million people. Samples were analysed for 17 drug residues by using liquid chromatography-tandem mass spectrometry. Consumption of methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), cocaine, codeine and methadone (mg/day/1000 people) was estimated by using a back-calculation formula. Methamphetamine, codeine, morphine and methadone were detected with high frequency (80-100%), followed by amphetamine (~60%), MDMA (~7%, i.e. 8 occasions) and methylone (3 occasions). An overall mean of 360 mg of methamphetamine and 60 mg of MDMA was estimated to have been consumed per day per 1000 people. Methamphetamine consumption was found at similar levels in both catchments (377 and 351 mg/day/1000 people). Cocaine was only detected in 1 catchment and on only 8 occasions. JWH-018 was detected in 1 catchment and only on 1 occasion. Methamphetamine, codeine and other opioids were detected at a consistent level throughout the week. 3,4-Methylenedioxymethamphetamine and methylone were detected only during the weekends. Wastewater analysis confirms that methamphetamine was one of the most commonly detected illegal drugs in Auckland and was detected consistently throughout the week. In contrast, cocaine and MDMA were rarely detected, with detection limited to weekends. [Lai FY, Wilkins C, Thai P, Mueller JF. An exploratory wastewater analysis study of drug use in Auckland, New Zealand. Drug Alcohol Rev 2017;00:000-000]. © 2017 Australasian Professional Society on Alcohol and other Drugs.

  19. Googling Stroke ASPECTS to Determine Disability: Exploratory Analysis from VISTA-Acute Collaboration.

    Directory of Open Access Journals (Sweden)

    Richard Beare

    Full Text Available The summed Alberta Stroke Program Early CT Score (ASPECTS is useful for predicting stroke outcome. The anatomical information in the CT template is rarely used for this purpose because traditional regression methods are not adept at handling collinearity (relatedness among brain regions. While penalized logistic regression (PLR can handle collinearity, it does not provide an intuitive understanding of the interaction among network structures in a way that eigenvector method such as PageRank can (used in Google search engine. In this exploratory analysis we applied graph theoretical analysis to explore the relationship among ASPECTS regions with respect to disability outcome. The Virtual International Stroke Trials Archive (VISTA was searched for patients who had infarct in at least one ASPECTS region (ASPECTS ≤ 9, ASPECTS = 10 were excluded, and disability (modified Rankin score/mRS. A directed graph was created from a cross correlation matrix (thresholded at false discovery rate of 0.01 of the ASPECTS regions and demographic variables and disability (mRS > 2. We estimated the network-based importance of each ASPECTS region by comparing PageRank and node strength measures. These results were compared with those from PLR. There were 185 subjects, average age 67.5 ± 12.8 years (55% Males. Model 1: demographic variables having no direct connection with disability, the highest PageRank was M2 (0.225, bootstrap 95% CI 0.215-0.347. Model 2: demographic variables having direct connection with disability, the highest PageRank were M2 (0.205, bootstrap 95% CI 0.194-0.367 and M5 (0.125, bootstrap 95% CI 0.096-0.204. Both models illustrate the importance of M2 region to disability. The PageRank method reveals complex interaction among ASPECTS regions with respects to disability. This approach may help to understand the infarcted brain network involved in stroke disability.

  20. Googling Stroke ASPECTS to Determine Disability: Exploratory Analysis from VISTA-Acute Collaboration.

    Science.gov (United States)

    Beare, Richard; Chen, Jian; Phan, Thanh G

    2015-01-01

    The summed Alberta Stroke Program Early CT Score (ASPECTS) is useful for predicting stroke outcome. The anatomical information in the CT template is rarely used for this purpose because traditional regression methods are not adept at handling collinearity (relatedness) among brain regions. While penalized logistic regression (PLR) can handle collinearity, it does not provide an intuitive understanding of the interaction among network structures in a way that eigenvector method such as PageRank can (used in Google search engine). In this exploratory analysis we applied graph theoretical analysis to explore the relationship among ASPECTS regions with respect to disability outcome. The Virtual International Stroke Trials Archive (VISTA) was searched for patients who had infarct in at least one ASPECTS region (ASPECTS ≤ 9, ASPECTS = 10 were excluded), and disability (modified Rankin score/mRS). A directed graph was created from a cross correlation matrix (thresholded at false discovery rate of 0.01) of the ASPECTS regions and demographic variables and disability (mRS > 2). We estimated the network-based importance of each ASPECTS region by comparing PageRank and node strength measures. These results were compared with those from PLR. There were 185 subjects, average age 67.5 ± 12.8 years (55% Males). Model 1: demographic variables having no direct connection with disability, the highest PageRank was M2 (0.225, bootstrap 95% CI 0.215-0.347). Model 2: demographic variables having direct connection with disability, the highest PageRank were M2 (0.205, bootstrap 95% CI 0.194-0.367) and M5 (0.125, bootstrap 95% CI 0.096-0.204). Both models illustrate the importance of M2 region to disability. The PageRank method reveals complex interaction among ASPECTS regions with respects to disability. This approach may help to understand the infarcted brain network involved in stroke disability.

  1. Local spatial frequency analysis for computer vision

    Science.gov (United States)

    Krumm, John; Shafer, Steven A.

    1990-01-01

    A sense of vision is a prerequisite for a robot to function in an unstructured environment. However, real-world scenes contain many interacting phenomena that lead to complex images which are difficult to interpret automatically. Typical computer vision research proceeds by analyzing various effects in isolation (e.g., shading, texture, stereo, defocus), usually on images devoid of realistic complicating factors. This leads to specialized algorithms which fail on real-world images. Part of this failure is due to the dichotomy of useful representations for these phenomena. Some effects are best described in the spatial domain, while others are more naturally expressed in frequency. In order to resolve this dichotomy, we present the combined space/frequency representation which, for each point in an image, shows the spatial frequencies at that point. Within this common representation, we develop a set of simple, natural theories describing phenomena such as texture, shape, aliasing and lens parameters. We show these theories lead to algorithms for shape from texture and for dealiasing image data. The space/frequency representation should be a key aid in untangling the complex interaction of phenomena in images, allowing automatic understanding of real-world scenes.

  2. Stellwagen Bank National Marine Sanctuary - Internal Wave Analysis Spatial Extent

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This feature class contains the spatial extent of the internal wave analysis. This area of interest was defined in interests of time. A cusory review of the 66 SAR...

  3. Robotic arm-assistedversusconventional unicompartmental knee arthroplasty: Exploratory secondary analysis of a randomised controlled trial.

    Science.gov (United States)

    Blyth, M J G; Anthony, I; Rowe, P; Banger, M S; MacLean, A; Jones, B

    2017-11-01

    This study reports on a secondary exploratory analysis of the early clinical outcomes of a randomised clinical trial comparing robotic arm-assisted unicompartmental knee arthroplasty (UKA) for medial compartment osteoarthritis of the knee with manual UKA performed using traditional surgical jigs. This follows reporting of the primary outcomes of implant accuracy and gait analysis that showed significant advantages in the robotic arm-assisted group. A total of 139 patients were recruited from a single centre. Patients were randomised to receive either a manual UKA implanted with the aid of traditional surgical jigs, or a UKA implanted with the aid of a tactile guided robotic arm-assisted system. Outcome measures included the American Knee Society Score (AKSS), Oxford Knee Score (OKS), Forgotten Joint Score, Hospital Anxiety Depression Scale, University of California at Los Angeles (UCLA) activity scale, Short Form-12, Pain Catastrophising Scale, somatic disease (Primary Care Evaluation of Mental Disorders Score), Pain visual analogue scale, analgesic use, patient satisfaction, complications relating to surgery, 90-day pain diaries and the requirement for revision surgery. From the first post-operative day through to week 8 post-operatively, the median pain scores for the robotic arm-assisted group were 55.4% lower than those observed in the manual surgery group (p = 0.040).At three months post-operatively, the robotic arm-assisted group had better AKSS (robotic median 164, interquartile range (IQR) 131 to 178, manual median 143, IQR 132 to 166), although no difference was noted with the OKS.At one year post-operatively, the observed differences with the AKSS had narrowed from a median of 21 points to a median of seven points (p = 0.106) (robotic median 171, IQR 153 to 179; manual median 164, IQR 144 to 182). No difference was observed with the OKS, and almost half of each group reached the ceiling limit of the score (OKS > 43). A greater proportion of patients

  4. Asymptotic analysis of spatial discretizations in implicit Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Densmore, Jeffery D [Los Alamos National Laboratory

    2009-01-01

    We perform an asymptotic analysis of spatial discretizations in Implicit Monte Carlo (IMC). We consider two asymptotic scalings: one that represents a time step that resolves the mean-free time, and one that corresponds to a fixed, optically large time step. We show that only the latter scaling results in a valid spatial discretization of the proper diffusion equation, and thus we conclude that IMC only yields accurate solutions when using optically large spatial cells if time steps are also optically large. We demonstrate the validity of our analysis with a set of numerical examples.

  5. Asymptotic analysis of spatial discretizations in implicit Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Densmore, Jeffery D [Los Alamos National Laboratory

    2008-01-01

    We perform an asymptotic analysis of spatial discretizations in Implicit Monte Carlo (IMC). We consider two asymptotic scalings: one that represents a time step that resolves the mean-free time, and one that corresponds to a fixed, optically large time step. We show that only the latter scaling results in a valid spatial discretization of the proper diffusion equation, and thus we conclude that IMC only yields accurate solutions when using optically large spatial cells if time steps are also optically large, We demonstrate the validity of our analysis with a set of numerical examples.

  6. Parsing the heterogeneity of depression: An exploratory factor analysis across commonly used depression rating scales.

    Science.gov (United States)

    Ballard, Elizabeth D; Yarrington, Julia S; Farmer, Cristan A; Lener, Marc S; Kadriu, Bashkim; Lally, Níall; Williams, Deonte; Machado-Vieira, Rodrigo; Niciu, Mark J; Park, Lawrence; Zarate, Carlos A

    2018-04-15

    Due to the heterogeneity of depressive symptoms-which can include depressed mood, anhedonia, negative cognitive biases, and altered activity levels-researchers often use a combination of depression rating scales to assess symptoms. This study sought to identify unidimensional constructs measured across rating scales for depression and to evaluate these constructs across clinical trials of a rapid-acting antidepressant (ketamine). Exploratory factor analysis (EFA) was conducted on baseline ratings from the Beck Depression Inventory (BDI), the Hamilton Depression Rating Scale (HAM-D), the Montgomery-Asberg Depression Rating Scale (MADRS), and the Snaith-Hamilton Pleasure Rating Scale (SHAPS). Inpatients with major depressive disorder (n = 76) or bipolar depression (n = 43) were participating in clinical ketamine trials. The trajectories of the resulting unidimensional scores were evaluated in 41 subjects with bipolar depression who participated in clinical ketamine trials. The best solution, which exhibited excellent fit to the data, comprised eight factors: Depressed Mood, Tension, Negative Cognition, Impaired Sleep, Suicidal Thoughts, Reduced Appetite, Anhedonia, and Amotivation. Various response patterns were observed across the clinical trial data, both in treatment effect (ketamine versus placebo) and in degree of placebo response, suggesting that use of these unidimensional constructs may reveal patterns not observed with traditional scoring of individual instruments. Limitations include: 1) small sample (and related inability to confirm measurement invariance); 2) absence of an independent sample for confirmation of factor structure; and 3) the treatment-resistant nature of the population, which may limit generalizability. The empirical identification of unidimensional constructs creates more refined scores that may elucidate the connection between specific symptoms and underlying pathophysiology. Published by Elsevier B.V.

  7. Chalcones and N-acylhydrazones: direct analogues? Exploratory data analysis applied to potential novel antileishmanial agents

    Directory of Open Access Journals (Sweden)

    Daniela Gonçalves Rando

    2010-06-01

    Full Text Available Leishmaniasis is an important health and social problem for which there is limited effective therapy. Chalcones and N-acylhydrazones have been studied as promising antileishmanial agents in enzymatic inhibition and in vitro assays. Since these chemical classes of compounds also resemble each other structurally, it would be useful to investigate whether they share direct analogy. Exploratory data analysis was applied to a library of chalcones and nitrated N-acylhydrazones assayed against Leishmania donovani to investigate their similarity. Under the conditions applied in the present study, the two classes did not present functional or structural analogy.As leishmanioses são importantes problemas sociais e de saúde pública para os quais a terapia farmacológica atual é, ainda, limitada. Chalconas e N-acilidrazonas têm sido estudadas como promissores agentes leishmanicidas tanto em ensaios in vitro quanto em ensaios de inibição de cisteíno-proteases importantes para o parasito. Uma vez que estas classes de compostos apresentam similaridade bidimensional, seria interessante estudar se estes compostos guardariam relação de analogia direta entre si. Análise exploratória de dados foi aplicada, então, à biblioteca de chalconas e N-acilidrazonas nitradas ensaiadas contra Leishmania donovani para investigar suas relações de similaridade. Os resultados mostraram que, ao menos sob as condições consideradas neste estudo, as duas classes de compostos não apresentam analogia estrutural e funcional simultaneamente, embora elas apresentem alguma similaridade estrutural.

  8. Effects of laboratory housing on exploratory behaviour, novelty discrimination and spatial reference memory in a subterranean, solitary rodent, the Cape mole-rat (Georychus capensis.

    Directory of Open Access Journals (Sweden)

    Maria Kathleen Oosthuizen

    Full Text Available A large number of laboratory and field based studies are being carried out on mole-rats, both in our research group and others. Several studies have highlighted the development of adverse behaviours in laboratory animals and have emphasised the importance of enrichment for captive animals. Hence we were interested in evaluating how laboratory housing would affect behavioural performance in mole-rats. We investigated exploratory behaviour, the ability to discriminate between novel and familiar environments and reference memory in the solitary Cape mole-rat (Georychus capensis. Our data showed that both wild and captive animals readily explore open spaces and tunnels. Wild animals were however more active than their captive counterparts. In the Y maze two trial discrimination task, wild animals failed to discriminate between novel and familiar environments, while laboratory housed mole-rats showed preferential spatial discrimination in terms of the length of time spent in the novel arm. The performance of the laboratory and wild animals were similar when tested for reference memory in the Y maze, both groups showed a significant improvement compared to the first day, from the 3rd day onwards. Wild animals made more mistakes whereas laboratory animals were slower in completing the task. The difference in performance between wild and laboratory animals in the Y-maze may be as a result of the lower activity of the laboratory animals. Laboratory maintained Cape mole-rats show classic behaviours resulting from a lack of stimulation such as reduced activity and increased aggression. However, they do display an improved novelty discrimination compared to the wild animals. Slower locomotion rate of the laboratory animals may increase the integration time of stimuli, hence result in a more thorough inspection of the surroundings. Unlike the captive animals, wild animals show flexibility in their responses to unpredictable events, which is an important

  9. Exploratory Factor Analysis and Psychometric Evaluation of the Teacher Reporting Attitude Scale for Child Sexual Abuse

    Science.gov (United States)

    Walsh, Kerryann; Rassafiani, Mehdi; Mathews, Ben; Farrell, Ann; Butler, Des

    2012-01-01

    This paper presents an evaluation of an instrument to measure teachers' attitudes toward reporting child sexual abuse and discusses the instrument's merit for research into reporting practice. Based on responses from 444 Australian teachers, the Teachers' Reporting Attitude Scale for Child Sexual Abuse was evaluated using exploratory factor…

  10. Are Review Skills and Academic Writing Skills Related? An Exploratory Analysis via Multi Source Feedback Tools

    Science.gov (United States)

    Razi, Salim

    2016-01-01

    Because students learn from each other as well as lecturers, it is important to create opportunities for collaboration in writing classes. Teachers now benefit from access to plagiarism detectors that can also provide feedback. This exploratory study considers the role of four review types, open and anonymous, involving the students themselves,…

  11. Resource materials for a GIS spatial analysis course

    Science.gov (United States)

    Raines, Gary L.

    2001-01-01

    This report consists of materials prepared for a GIS spatial analysis course offered as part of the Geography curriculum at the University of Nevada, Reno and the University of California at Santa Barbara in the spring of 2000. The report is intended to share information with instructors preparing spatial-modeling training and scientists with advanced GIS expertise. The students taking this class had completed each universities GIS curriculum and had a foundation in statistics as part of a science major. This report is organized into chapters that contain the following: Slides used during lectures, Guidance on the use of Arcview, Introduction to filtering in Arcview, Conventional and spatial correlation in Arcview, Tools for fuzzification in Arcview, Data and instructions for creating using ArcSDM for simple weights-of-evidence, fuzzy logic, and neural network models for Carlin-type gold deposits in central Nevada, Reading list on spatial modeling, and Selected student spatial-modeling posters from the laboratory exercises.

  12. Exploratory Nuclear Reactor Safety Analysis and Visualization via Integrated Topological and Geometric Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Maljovec, Dan [Univ. of Utah, Salt Lake City, UT (United States); Wang, Bei [Univ. of Utah, Salt Lake City, UT (United States); Pascucci, Valerio [Univ. of Utah, Salt Lake City, UT (United States); Bremer, Peer-Timo [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Pernice, Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Nourgaliev, Robert [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2013-10-01

    and 2) topology-based methodologies to interactively visualize multidimensional data and extract risk-informed insights. Regarding item 1) we employ learning algorithms that aim to infer/predict simulation outcome and decide the coordinate in the input space of the next sample that maximize the amount of information that can be gained from it. Such methodologies can be used to both explore and exploit the input space. The later one is especially used for safety analysis scopes to focus samples along the limit surface, i.e. the boundaries in the input space between system failure and system success. Regarding item 2) we present a software tool that is designed to analyze multi-dimensional data. We model a large-scale nuclear simulation dataset as a high-dimensional scalar function defined over a discrete sample of the domain. First, we provide structural analysis of such a function at multiple scales and provide insight into the relationship between the input parameters and the output. Second, we enable exploratory analysis for users, where we help the users to differentiate features from noise through multi-scale analysis on an interactive platform, based on domain knowledge and data characterization. Our analysis is performed by exploiting the topological and geometric properties of the domain, building statistical models based on its topological segmentations and providing interactive visual interfaces to facilitate such explorations.

  13. Spatial Assessment of Road Traffic Injuries in the Greater Toronto Area (GTA: Spatial Analysis Framework

    Directory of Open Access Journals (Sweden)

    Sina Tehranchi

    2017-03-01

    Full Text Available This research presents a Geographic Information Systems (GIS and spatial analysis approach based on the global spatial autocorrelation of road traffic injuries for identifying spatial patterns. A locational spatial autocorrelation was also used for identifying traffic injury at spatial level. Data for this research study were acquired from Canadian Institute for Health Information (CIHI based on 2004 and 2011. Moran’s I statistics were used to examine spatial patterns of road traffic injuries in the Greater Toronto Area (GTA. An assessment of Getis-Ord Gi* statistic was followed as to identify hot spots and cold spots within the study area. The results revealed that Peel and Durham have the highest collision rate for other motor vehicle with motor vehicle. Geographic weighted regression (GWR technique was conducted to test the relationships between the dependent variable, number of road traffic injury incidents and independent variables such as number of seniors, low education, unemployed, vulnerable groups, people smoking and drinking, urban density and average median income. The result of this model suggested that number of seniors and low education have a very strong correlation with the number of road traffic injury incidents.

  14. Assessment of tuberculosis spatial hotspot areas in Antananarivo, Madagascar, by combining spatial analysis and genotyping.

    Science.gov (United States)

    Ratovonirina, Noël Harijaona; Rakotosamimanana, Niaina; Razafimahatratra, Solohery Lalaina; Raherison, Mamy Serge; Refrégier, Guislaine; Sola, Christophe; Rakotomanana, Fanjasoa; Rasolofo Razanamparany, Voahangy

    2017-08-14

    Tuberculosis (TB) remains a public health problem in Madagascar. A crucial element of TB control is the development of an easy and rapid method for the orientation of TB control strategies in the country. Our main objective was to develop a TB spatial hotspot identification method by combining spatial analysis and TB genotyping method in Antananarivo. Sputa of new pulmonary TB cases from 20 TB diagnosis and treatment centers (DTCs) in Antananarivo were collected from August 2013 to May 2014 for culture. Mycobacterium tuberculosis complex (MTBC) clinical isolates were typed by spoligotyping on a Luminex® 200 platform. All TB patients were respectively localized according to their neighborhood residence and the spatial distribution of all pulmonary TB patients and patients with genotypic clustered isolates were scanned respectively by the Kulldorff spatial scanning method for identification of significant spatial clustering. Areas exhibiting spatial clustering of patients with genotypic clustered isolates were considered as hotspot TB areas for transmission. Overall, 467 new cases were included in the study, and 394 spoligotypes were obtained (84.4%). New TB cases were distributed in 133 of the 192 Fokontany (administrative neighborhoods) of Antananarivo (1 to 15 clinical patients per Fokontany) and patients with genotypic clustered isolates were distributed in 127 of the 192 Fokontany (1 to 13 per Fokontany). A single spatial focal point of epidemics was detected when ignoring genotypic data (p = 0.039). One Fokontany of this focal point and three additional ones were detected to be spatially clustered when taking genotypes into account (p Madagascar and will allow better TB control strategies by public health authorities.

  15. Spatially explicit spectral analysis of point clouds and geospatial data

    Science.gov (United States)

    Buscombe, Daniel D.

    2015-01-01

    The increasing use of spatially explicit analyses of high-resolution spatially distributed data (imagery and point clouds) for the purposes of characterising spatial heterogeneity in geophysical phenomena necessitates the development of custom analytical and computational tools. In recent years, such analyses have become the basis of, for example, automated texture characterisation and segmentation, roughness and grain size calculation, and feature detection and classification, from a variety of data types. In this work, much use has been made of statistical descriptors of localised spatial variations in amplitude variance (roughness), however the horizontal scale (wavelength) and spacing of roughness elements is rarely considered. This is despite the fact that the ratio of characteristic vertical to horizontal scales is not constant and can yield important information about physical scaling relationships. Spectral analysis is a hitherto under-utilised but powerful means to acquire statistical information about relevant amplitude and wavelength scales, simultaneously and with computational efficiency. Further, quantifying spatially distributed data in the frequency domain lends itself to the development of stochastic models for probing the underlying mechanisms which govern the spatial distribution of geological and geophysical phenomena. The software packagePySESA (Python program for Spatially Explicit Spectral Analysis) has been developed for generic analyses of spatially distributed data in both the spatial and frequency domains. Developed predominantly in Python, it accesses libraries written in Cython and C++ for efficiency. It is open source and modular, therefore readily incorporated into, and combined with, other data analysis tools and frameworks with particular utility for supporting research in the fields of geomorphology, geophysics, hydrography, photogrammetry and remote sensing. The analytical and computational structure of the toolbox is

  16. Spatially explicit spectral analysis of point clouds and geospatial data

    Science.gov (United States)

    Buscombe, Daniel

    2016-01-01

    The increasing use of spatially explicit analyses of high-resolution spatially distributed data (imagery and point clouds) for the purposes of characterising spatial heterogeneity in geophysical phenomena necessitates the development of custom analytical and computational tools. In recent years, such analyses have become the basis of, for example, automated texture characterisation and segmentation, roughness and grain size calculation, and feature detection and classification, from a variety of data types. In this work, much use has been made of statistical descriptors of localised spatial variations in amplitude variance (roughness), however the horizontal scale (wavelength) and spacing of roughness elements is rarely considered. This is despite the fact that the ratio of characteristic vertical to horizontal scales is not constant and can yield important information about physical scaling relationships. Spectral analysis is a hitherto under-utilised but powerful means to acquire statistical information about relevant amplitude and wavelength scales, simultaneously and with computational efficiency. Further, quantifying spatially distributed data in the frequency domain lends itself to the development of stochastic models for probing the underlying mechanisms which govern the spatial distribution of geological and geophysical phenomena. The software package PySESA (Python program for Spatially Explicit Spectral Analysis) has been developed for generic analyses of spatially distributed data in both the spatial and frequency domains. Developed predominantly in Python, it accesses libraries written in Cython and C++ for efficiency. It is open source and modular, therefore readily incorporated into, and combined with, other data analysis tools and frameworks with particular utility for supporting research in the fields of geomorphology, geophysics, hydrography, photogrammetry and remote sensing. The analytical and computational structure of the toolbox is described

  17. Application of Fourier analysis to multispectral/spatial recognition

    Science.gov (United States)

    Hornung, R. J.; Smith, J. A.

    1973-01-01

    One approach for investigating spectral response from materials is to consider spatial features of the response. This might be accomplished by considering the Fourier spectrum of the spatial response. The Fourier Transform may be used in a one-dimensional to multidimensional analysis of more than one channel of data. The two-dimensional transform represents the Fraunhofer diffraction pattern of the image in optics and has certain invariant features. Physically the diffraction pattern contains spatial features which are possibly unique to a given configuration or classification type. Different sampling strategies may be used to either enhance geometrical differences or extract additional features.

  18. A kernel version of spatial factor analysis

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg

    2009-01-01

    Based on work by Pearson in 1901, Hotelling in 1933 introduced principal component analysis (PCA). PCA is often used for general feature generation and linear orthogonalization or compression by dimensionality reduction of correlated multivariate data, see Jolliffe for a comprehensive description...

  19. Collaborative spatial analysis and modelling in a research environment

    CSIR Research Space (South Africa)

    Naudé, A

    2006-02-01

    Full Text Available of an open-source geoportal and geospatial content management framework (adapted for low-bandwidth environments), customisable spatial analysis workbenches (providing guidance and tools for geoprocesses such as spatial disaggregation) and the formulation... resources and processes. In these two sections, the concept of a knowledge geoportal is introduced. A knowledge geoportal includes the notion of customisable workbenches, aimed at addressing the other key problems seen in Figure 1. Further...

  20. Graph Wavelets for Spatial Traffic Analysis

    Science.gov (United States)

    2002-07-15

    Proceedings of ACM SIGCOMM ’95, 1995, pp. 100–113. [5] J. Levy-Vehel and R. Riedi, “Fractional Brownian motion and data traffic modeling: the other end of...similarity and long-range dependence, [3, 4]; and multifractality and local scaling [5, 6]. Many of the key results in traffic time scaling analysis have...as cascades: Investigating the multifractal nature of Internet WAN traffic,” in Proceedings of SIGCOMM ’98, October 1998, pp. 42–55. [7] P. Abry and

  1. Mathematical Analysis of Urban Spatial Networks

    CERN Document Server

    Blanchard, Philippe

    2009-01-01

    Cities can be considered to be among the largest and most complex artificial networks created by human beings. Due to the numerous and diverse human-driven activities, urban network topology and dynamics can differ quite substantially from that of natural networks and so call for an alternative method of analysis. The intent of the present monograph is to lay down the theoretical foundations for studying the topology of compact urban patterns, using methods from spectral graph theory and statistical physics. These methods are demonstrated as tools to investigate the structure of a number of real cities with widely differing properties: medieval German cities, the webs of city canals in Amsterdam and Venice, and a modern urban structure such as found in Manhattan. Last but not least, the book concludes by providing a brief overview of possible applications that will eventually lead to a useful body of knowledge for architects, urban planners and civil engineers.

  2. Application of the exploratory analysis of data in the geographical discrimination of okra of Rio Grande do Norte and Pernambuco

    Directory of Open Access Journals (Sweden)

    Francisco Santos Panero

    2009-11-01

    Full Text Available The contents of Cu, Zn, Na, Fe, K, Ca, Mn, Mg, PO43-, Cl- and SO42- were determined in samples of okra of the municipal districts of Caruaru and Vitória de Santo Antão, in Pernambuco, as well as in the municipal districts of Ceará-Mirim, Macaíba and Extremoz in the state of Rio Grande do Norte. The objective of this work is the application of two methods of  exploratory analysis of data: Principal Component Analysis - PCA and Hierarquical Cluster Analysis - HCA in the geographical discrimination of okra originating in the states of Rio Grande do Norte and Pernambuco. The results showed that Cl- and Na were the main elements for the differentiation of the samples of Rio Grande do Norte and, the samples of Pernambuco presented the largest amount of Fe, Cu, Mn, Mg, Ca, Zn, K, PO43-, and SO42-. Boths the methods of exploratory analysis of data investigated are efficient for geographical discrimination of okra originating in Rio Grande do Norte and Pernambuco.

  3. Bacterial identification of the vaginal microbiota in Ecuadorian pregnant teenagers: an exploratory analysis.

    Science.gov (United States)

    Salinas, Ana María; Osorio, Verónica Gabriela; Endara, Pablo Francisco; Salazar, Eduardo Ramiro; Vasco, Gabriela Piedad; Vivero, Sandra Guadalupe; Machado, Antonio

    2018-01-01

    Bacterial vaginosis (BV) is a microbial imbalance (i.e., dysbiosis) that can produce serious medical effects in women at childbearing age. Little is known, however, about the incidence of BV or vaginal microbiota dysbiosis in pregnant teenagers in low and middle-income countries such as Ecuador. The scope of this exploratory analysis was to study the relationship between epidemiologic and microbial risk factors. Among the microbiology risk factors this study investigated five Lactobacillus species, two of them know in preview studies as microbiology risk factors for BV development ( Lactobacillus acidophilus and Lactobacillus iners ), and the last three known for being associated with a healthy vaginal tract ( Lactobacillus crispatus , Lactobacillus gasseri and Lactobacillus jensenii ). In addition, fastidious anaerobes known to be microbial risk factors for BV development in pregnant teenagers were searched as well, more exactly, Gardnerella vaginalis , Atopobium vaginae and Mobiluncus mulieris . Ninety-five healthy adolescent pregnant women, visiting a secondary level hospital in Quito, Ecuador, were enrolled into the study in 2015. The enrolled patients were between 10 to 13 weeks of pregnancy. Four epidemiological risk factors were collected in a survey: age, civil status, sexual partners and condom use. Also, vaginal pH was measured as a health risk factor. DNA was extracted from endocervical and exocervical epithelia from all the patients' samples. PCR analysis was performed in order to characterize the presence of the eight bacterial species known as risk factors for BV development, targeting three anaerobes and five Lactobacillus species. Univariate and multivariate analysis were performed to identify associated factors for the presence of anaerobic species using logistic regression. The 95 vaginal microflora samples of these teenagers were analyzed. Two of the bacterial species known to cause BV: A. vaginae (100%) and G. vaginalis (93.7%) were found in

  4. Development and psychometric properties rating scale of "clinical competency evaluation in mental health nurses": Exploratory factor analysis.

    Science.gov (United States)

    Moskoei, Sara; Mohtashami, Jamileh; Ghalenoeei, Mahdie; Nasiri, Maliheh; Tafreshi, Mansoreh Zaghari

    2017-04-01

    Evaluation of clinical competency in nurses has a distinct importance in healthcare due to its significant impact on improving the quality of patient care and creation of opportunities for professional promotion. This is a psychometric study for development of the "Clinical Competency of Mental Health Nursing"(CCMHN) rating scale. In this methodological research that was conducted in 2015, in Tehran, Iran, the main items were developed after literature review and the validity and reliability of the tool were identified. The face, content (content validity ratio and content validity index) and construct validities were calculated. For face and content validity, experts' comments were used. Exploratory factor analysis was used to determine the construct validity. The reliability of scale was determined by the internal consistency and inter-rater correlation. The collected data were analyzed by SPSS version 16, using descriptive statistical analysis. A scale with 45 items in two parts including Emotional/Moral and Specific Care competencies was developed. Content validity ratio and content validity index were 0.88, 0.97 respectively. Exploratory factor analysis indicated two factors: The first factor with 23.93 eigenvalue and second factor with eigenvalue 2.58. Cronbach's alpha coefficient for determination of internal consistency was 0.98 and the ICC for confirmation inter-rater correlation was 0.98. A scale with 45 items and two areas was developed with appropriate validity and reliability. This scale can be used to assess the clinical competency in nursing students and mental health nurses.

  5. Spectral Knowledge (SK-UTALCA): Software for Exploratory Analysis of High-Resolution Spectral Reflectance Data on Plant Breeding.

    Science.gov (United States)

    Lobos, Gustavo A; Poblete-Echeverría, Carlos

    2016-01-01

    This article describes public, free software that provides efficient exploratory analysis of high-resolution spectral reflectance data. Spectral reflectance data can suffer from problems such as poor signal to noise ratios in various wavebands or invalid measurements due to changes in incoming solar radiation or operator fatigue leading to poor orientation of sensors. Thus, exploratory data analysis is essential to identify appropriate data for further analyses. This software overcomes the problem that analysis tools such as Excel are cumbersome to use for the high number of wavelengths and samples typically acquired in these studies. The software, Spectral Knowledge (SK-UTALCA), was initially developed for plant breeding, but it is also suitable for other studies such as precision agriculture, crop protection, ecophysiology plant nutrition, and soil fertility. Various spectral reflectance indices (SRIs) are often used to relate crop characteristics to spectral data and the software is loaded with 255 SRIs which can be applied quickly to the data. This article describes the architecture and functions of SK-UTALCA and the features of the data that led to the development of each of its modules.

  6. Overweight and obesity in India: policy issues from an exploratory multi-level analysis.

    Science.gov (United States)

    Siddiqui, Md Zakaria; Donato, Ronald

    2016-06-01

    This article analyses a nationally representative household dataset-the National Family Health Survey (NFHS-3) conducted in 2005 to 2006-to examine factors influencing the prevalence of overweight/obesity in India. The dataset was disaggregated into four sub-population groups-urban and rural females and males-and multi-level logit regression models were used to estimate the impact of particular covariates on the likelihood of overweight/obesity. The multi-level modelling approach aimed to identify individual and macro-level contextual factors influencing this health outcome. In contrast to most studies on low-income developing countries, the findings reveal that education for females beyond a particular level of educational attainment exhibits a negative relationship with the likelihood of overweight/obesity. This relationship was not observed for males. Muslim females and all Sikh sub-populations have a higher likelihood of overweight/obesity suggesting the importance of socio-cultural influences. The results also show that the relationship between wealth and the probability of overweight/obesity is stronger for males than females highlighting the differential impact of increasing socio-economic status on gender. Multi-level analysis reveals that states exerted an independent influence on the likelihood of overweight/obesity beyond individual-level covariates, reflecting the importance of spatially related contextual factors on overweight/obesity. While this study does not disentangle macro-level 'obesogenic' environmental factors from socio-cultural network influences, the results highlight the need to refrain from adopting a 'one size fits all' policy approach in addressing the overweight/obesity epidemic facing India. Instead, policy implementation requires a more nuanced and targeted approach to incorporate the growing recognition of socio-cultural and spatial contextual factors impacting on healthy behaviours. © The Author 2015. Published by Oxford

  7. Spatial regression analysis of traffic crashes in Seoul.

    Science.gov (United States)

    Rhee, Kyoung-Ah; Kim, Joon-Ki; Lee, Young-ihn; Ulfarsson, Gudmundur F

    2016-06-01

    Traffic crashes can be spatially correlated events and the analysis of the distribution of traffic crash frequency requires evaluation of parameters that reflect spatial properties and correlation. Typically this spatial aspect of crash data is not used in everyday practice by planning agencies and this contributes to a gap between research and practice. A database of traffic crashes in Seoul, Korea, in 2010 was developed at the traffic analysis zone (TAZ) level with a number of GIS developed spatial variables. Practical spatial models using available software were estimated. The spatial error model was determined to be better than the spatial lag model and an ordinary least squares baseline regression. A geographically weighted regression model provided useful insights about localization of effects. The results found that an increased length of roads with speed limit below 30 km/h and a higher ratio of residents below age of 15 were correlated with lower traffic crash frequency, while a higher ratio of residents who moved to the TAZ, more vehicle-kilometers traveled, and a greater number of access points with speed limit difference between side roads and mainline above 30 km/h all increased the number of traffic crashes. This suggests, for example, that better control or design for merging lower speed roads with higher speed roads is important. A key result is that the length of bus-only center lanes had the largest effect on increasing traffic crashes. This is important as bus-only center lanes with bus stop islands have been increasingly used to improve transit times. Hence the potential negative safety impacts of such systems need to be studied further and mitigated through improved design of pedestrian access to center bus stop islands. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Multi-spatial analysis of aeolian dune-field patterns

    Science.gov (United States)

    Ewing, Ryan C.; McDonald, George D.; Hayes, Alex G.

    2015-07-01

    Aeolian dune-fields are composed of different spatial scales of bedform patterns that respond to changes in environmental boundary conditions over a wide range of time scales. This study examines how variations in spatial scales of dune and ripple patterns found within dune fields are used in environmental reconstructions on Earth, Mars and Titan. Within a single bedform type, different spatial scales of bedforms emerge as a pattern evolves from an initial state into a well-organized pattern, such as with the transition from protodunes to dunes. Additionally, different types of bedforms, such as ripples, coarse-grained ripples and dunes, coexist at different spatial scales within a dune-field. Analysis of dune-field patterns at the intersection of different scales and types of bedforms at different stages of development provides a more comprehensive record of sediment supply and wind regime than analysis of a single scale and type of bedform. Interpretations of environmental conditions from any scale of bedform, however, are limited to environmental signals associated with the response time of that bedform. Large-scale dune-field patterns integrate signals over long-term climate cycles and reveal little about short-term variations in wind or sediment supply. Wind ripples respond instantly to changing conditions, but reveal little about longer-term variations in wind or sediment supply. Recognizing the response time scales across different spatial scales of bedforms maximizes environmental interpretations from dune-field patterns.

  9. Tuberculosis and living conditions in Salvador, Brazil: a spatial analysis.

    Science.gov (United States)

    Erazo, Carlos; Pereira, Susan M; Costa, Maria da Conceição N; Evangelista-Filho, Delsuc; Braga, José Ueleres; Barreto, Mauricio L

    2014-07-01

    To investigate spatial tuberculosis (TB) distribution patterns and the association between living conditions and incidence of the disease in Salvador, Bahia, Brazil. An ecological study with neighborhood as the unit of analysis. Data was collected from the Notifiable Diseases Information System (Sistema de Informação de Agravos de Notificação, SINAN) and the Brazilian Institute of Geography and Statistics (Instituto Brasileiro de Geografia e Estatística, IBGE). Rates of TB incidence were transformed and smoothed. Spatial analysis was applied to identify spatial auto-correlation and "hotspot" areas of high and low risk. The relationship between TB and living conditions was confirmed by spatial linear regression. The incidence of TB in Salvador displayed heterogeneous patterns, with higher rates occurring in neighborhoods with poor living conditions in 1995 - 1996. Over the study period, disease occurrence declined, particularly in less-privileged strata. In 2004 - 2005, the association between living conditions and TB was no longer observed. The heterogeneous spatial distribution of TB in Salvador previously reflected inequalities related to living conditions. Improvements in such conditions and health care for the less privileged may have contributed to observed changes.

  10. The adolescent body image satisfaction scale for males: exploratory factor analysis and implications for strength and conditioning professionals.

    Science.gov (United States)

    Leone, James E; Mullin, Elizabeth M; Maurer-Starks, Suanne S; Rovito, Michael J

    2014-09-01

    The purpose of this study was to determine whether there is evidence of reliability and validity for the Adolescent Body Image Satisfaction Scale (ABISS), an instrument previously developed to measure adolescent body image. A sample (N = 330) of adolescent males, aged 14-19 years, completed the ABISS to determine current body image satisfaction. Data were analyzed for measures of instrument composite reliability and initial content and construct validity. Exploratory factor analysis supported a 3-factor solution (16 total items), which explained 42.7% of variance in the model. Composite reliability for the subscales, body competence, body inadequacy, and internal conflict ranged from 0.64 to 0.82. Exploratory factor analysis of the ABISS provides initial psychometric support for a valid and reliable measure for assessing adolescent male body image, which also can be used as a needs assessment tool. Strength and conditioning professionals should be aware of their athlete and client psychological attributes, many of whom are adolescents. Understanding how adolescents view their bodies and their body image will assist professionals in designing appropriate, health-promotive strength programs, while at the same time monitoring for signs of body image dissatisfaction. Assessing body image can help heighten awareness and possibly encourage preventative programming to help avert negative health practices (e.g., performance-enhancing drug use, exercise addictions, disordered eating). The ABISS seems to have preliminary psychometric support to be a valid and reliable instrument that helps gauge at-risk populations.

  11. Spatial statistical analysis of dissatisfaction with the performance of ...

    African Journals Online (AJOL)

    The analysis reveals spatial clustering in the level of dissatisfaction with the performance of local government. It also reveals percentage of respondents dissatisfied with dwelling, mean sense of safety index, and percentage agree the country is going in the wrong direction, as significant predictors of the level of local ...

  12. Visuo-Spatial Performance in Autism: A Meta-Analysis

    Science.gov (United States)

    Muth, Anne; Hönekopp, Johannes; Falter, Christine M.

    2014-01-01

    Visuo-spatial skills are believed to be enhanced in autism spectrum disorders (ASDs). This meta-analysis tests the current state of evidence for Figure Disembedding, Block Design, Mental Rotation and Navon tasks in ASD and neurotypicals. Block Design (d = 0.32) and Figure Disembedding (d = 0.26) showed superior performance for ASD with large…

  13. Spatial analysis of fluoride concentrations in drinking water and ...

    African Journals Online (AJOL)

    Namibia, the driest country in sub-Saharan Africa, is largely reliant on groundwater for its potable water demand and groundwater is a major source of naturally-occurring fluoride. This study assessed the spatial distribution of fluoride in potable water and appraised the population at risk for high fluoride intake. Analysis of ...

  14. Spatial Analysis of Political Capital Citation Using Remote Sensing ...

    African Journals Online (AJOL)

    Spatial Analysis of Political Capital Citation Using Remote Sensing and GIS; A Case Study of Lokoja. ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more information about how to print, save, ...

  15. Spatial and temporal analysis of mass movement using dendrochronology

    NARCIS (Netherlands)

    Braam, R.R.; Weiss, E.E.J.; Burrough, P.A.

    1987-01-01

    Tree growth and inclination on sloping land is affected by mass movement. Suitable analysis of tree growth and tree form can therefore provide considerable information on mass movement activity. This paper reports a new, automated method for studying the temporal and spatial aspects of mass

  16. Spatial and temporal expression analysis of D- myo -inositol 3 ...

    African Journals Online (AJOL)

    1á (eukaryotic elongation factor 1-alpha) using SYBER-Green. The qRT-PCR data analysis indicated that the expression of the four highly conserved MIPS genes is both temporally and spatially regulated, information much needed for reverse ...

  17. Spatial Analysis of Soil Erosion in Swaziland | Manyatsi | UNISWA ...

    African Journals Online (AJOL)

    In this paper a spatial analysis was undertaken to identify the impact of the factors controlling soil erosion: land management systems, stocking pressure, soil erodibility, average slope of the land, and mean annual rainfall. A binary classification was applied to a broad land cover classes map produced from image ...

  18. Analysis of spatial pattern of settlements in the federal capital ...

    African Journals Online (AJOL)

    Human settlements are important, seemingly static but dynamic, features of the cultural landscape that have attracted several studies due to the important role they play in human life. This paper examined the spatial distribution of settlements in the Federal Capital Territory (FCT) of Nigeria. The analysis uses vector based ...

  19. Variability of Soil Temperature: A Spatial and Temporal Analysis.

    Science.gov (United States)

    Walsh, Stephen J.; And Others

    1991-01-01

    Discusses an analysis of the relationship of soil temperatures at 3 depths to various climatic variables along a 200-kilometer transect in west-central Oklahoma. Reports that temperature readings increased from east to west. Concludes that temperature variations were explained by a combination of spatial, temporal, and biophysical factors. (SG)

  20. A Scheme for Initial Exploratory Data Analysis of Multivariate Image Data

    DEFF Research Database (Denmark)

    Hilger, Klaus Baggesen; Nielsen, Allan Aasbjerg; Larsen, Rasmus

    2001-01-01

    A new scheme is proposed for handling initial exploratory analyses of multivariate image data. The method is invariant to linear transformations of the original data and is useful for data fusion of multisource measurements. The scheme includes dimensionality reduction followed by unsupervised...... clustering of the data. A transformation is proposed which maximizes autocorrelation by projection onto subspaces with signal-to-noise ratio dependent variance. We apply the traditional fuzzy c-means algorithm and introduce two additional memberships enhancing the textural awareness of the algorithm. Cluster...

  1. From bed to bench: bridging from informatics practice to theory: an exploratory analysis.

    Science.gov (United States)

    Haux, R; Lehmann, C U

    2014-01-01

    In 2009, Applied Clinical Informatics (ACI)--focused on applications in clinical informatics--was launched as a companion journal to Methods of Information in Medicine (MIM). Both journals are official journals of the International Medical Informatics Association. To explore which congruencies and interdependencies exist in publications from theory to practice and from practice to theory and to determine existing gaps. Major topics discussed in ACI and MIM were analyzed. We explored if the intention of publishing companion journals to provide an information bridge from informatics theory to informatics practice and vice versa could be supported by this model. In this manuscript we will report on congruencies and interdependences from practice to theory and on major topics in MIM. Retrospective, prolective observational study on recent publications of ACI and MIM. All publications of the years 2012 and 2013 were indexed and analyzed. Hundred and ninety-six publications were analyzed (ACI 87, MIM 109). In MIM publications, modelling aspects as well as methodological and evaluation approaches for the analysis of data, information, and knowledge in biomedicine and health care were frequently raised - and often discussed from an interdisciplinary point of view. Important themes were ambient-assisted living, anatomic spatial relations, biomedical informatics as scientific discipline, boosting, coding, computerized physician order entry, data analysis, grid and cloud computing, health care systems and services, health-enabling technologies, health information search, health information systems, imaging, knowledge-based decision support, patient records, signal analysis, and web science. Congruencies between journals could be found in themes, but with a different focus on content. Interdependencies from practice to theory, found in these publications, were only limited. Bridging from informatics theory to practice and vice versa remains a major component of successful

  2. Image Chunking: Defining Spatial Building Blocks for Scene Analysis.

    Science.gov (United States)

    1987-04-01

    mumgs0.USmusa 7.AUWOJO 4. CIUTAC Rm6ANT Wuugme*j James V/. Mlahoney DACA? 6-85-C-00 10 NOQ 1 4-85-K-O 124 Artificial Inteligence Laboratory US USS 545...0197 672 IMAGE CHUWING: DEINING SPATIAL UILDING PLOCKS FOR 142 SCENE ANRLYSIS(U) MASSACHUSETTS INST OF TECH CAIIAIDGE ARTIFICIAL INTELLIGENCE LAO J...Technical Report 980 F-Image Chunking: Defining Spatial Building Blocks for Scene DTm -Analysis S ELECTED James V. Mahoney’ MIT Artificial Intelligence

  3. Hierarchical Spatial Analysis of Extreme Precipitation in Urban Areas

    Science.gov (United States)

    Rajulapati, C. R.; Mujumdar, P.

    2015-12-01

    Quantification of extreme precipitation is important for hydrologic designs. Due to lack of availability of extreme precipitation data for sufficiently large number of years, estimating the probability of extreme events is difficult and extrapolating the distributions to locations where observations are not available is challenging. In an urban setting, the spatial variation of precipitation can be high; the precipitation amounts and patterns often vary within short distances of less than 10 km. Therefore it is crucial to study the uncertainties in the spatial variation of precipitation in urban areas. In this work, the extreme precipitation is modeled spatially using the Bayesian hierarchical spatial analysis and the spatial variation of return levels is studied. The analysis is carried out with both the Peak over Threshold (PoT) and the Block Maxima approaches for defining the extreme precipitation. The study area is Bangalore city, India. Daily data for seventeen stations in and around Bangalore city are considered in the study. The threshold exceedences are modeled using a Generalized Pareto (GP) distribution and the block maxima are modeled using Generalized Extreme Value (GEV) distribution. In the hierarchical analysis, the statistical model is specified in three layers. The data layer models the data (either block maxima or the threshold exceedences) at each station. In the process layer, the latent spatial process characterized by geographical and climatological covariates (lat-lon, elevation, mean temperature etc.) which drives the extreme precipitation is modeled and in the prior level, the prior distributions that govern the latent process are modeled. Markov Chain Monte Carlo (MCMC) algorithm is used to obtain the samples of parameters from the posterior distribution of parameters. The spatial maps of return levels for specified return periods, along with the associated uncertainties, are obtained. The results show that there is significant variation in

  4. Analysis of exploratory wells in the Cerro Prieto Field and the Mexicali Valley

    Energy Technology Data Exchange (ETDEWEB)

    Cobo R., J.M.; Bermejo M., F.J.

    1982-08-10

    Agricultural development in the Mexicali Valley and in the high cost of electric power required to operate the irrigation wells in the Valley prompted the Mexican government to investigate the possibility of taking advantage of thermal manifestations in the area located 28 km southeast of the city of Mexicali to generate electric power and thereby partially decrease the flight of foreign exchange. In 1958, a geologic study of the southern and southeastern zone of Mexicali was conducted to identify the possibilities of tapping geothermal resources. The purpose of this study was to gain knowledge of the geologic conditions in this area and, if possible, to establish the location of exploratory and production wells and, on the basis of the results of the former, examine the geologic history in order to gain knowledge and understanding of the structural control of the steam. On the basis of this study, it was recommended that 3 exploratory wells should be drilled in order to locate weak zones that would easily allow for steam flow.

  5. Spatially adaptive mixture modeling for analysis of FMRI time series.

    Science.gov (United States)

    Vincent, Thomas; Risser, Laurent; Ciuciu, Philippe

    2010-04-01

    Within-subject analysis in fMRI essentially addresses two problems, the detection of brain regions eliciting evoked activity and the estimation of the underlying dynamics. In Makni et aL, 2005 and Makni et aL, 2008, a detection-estimation framework has been proposed to tackle these problems jointly, since they are connected to one another. In the Bayesian formalism, detection is achieved by modeling activating and nonactivating voxels through independent mixture models (IMM) within each region while hemodynamic response estimation is performed at a regional scale in a nonparametric way. Instead of IMMs, in this paper we take advantage of spatial mixture models (SMM) for their nonlinear spatial regularizing properties. The proposed method is unsupervised and spatially adaptive in the sense that the amount of spatial correlation is automatically tuned from the data and this setting automatically varies across brain regions. In addition, the level of regularization is specific to each experimental condition since both the signal-to-noise ratio and the activation pattern may vary across stimulus types in a given brain region. These aspects require the precise estimation of multiple partition functions of underlying Ising fields. This is addressed efficiently using first path sampling for a small subset of fields and then using a recently developed fast extrapolation technique for the large remaining set. Simulation results emphasize that detection relying on supervised SMM outperforms its IMM counterpart and that unsupervised spatial mixture models achieve similar results without any hand-tuning of the correlation parameter. On real datasets, the gain is illustrated in a localizer fMRI experiment: brain activations appear more spatially resolved using SMM in comparison with classical general linear model (GLM)-based approaches, while estimating a specific parcel-based HRF shape. Our approach therefore validates the treatment of unsmoothed fMRI data without fixed GLM

  6. Quantitative analysis of spatial variability of geotechnical parameters

    Science.gov (United States)

    Fang, Xing

    2018-04-01

    Geotechnical parameters are the basic parameters of geotechnical engineering design, while the geotechnical parameters have strong regional characteristics. At the same time, the spatial variability of geotechnical parameters has been recognized. It is gradually introduced into the reliability analysis of geotechnical engineering. Based on the statistical theory of geostatistical spatial information, the spatial variability of geotechnical parameters is quantitatively analyzed. At the same time, the evaluation of geotechnical parameters and the correlation coefficient between geotechnical parameters are calculated. A residential district of Tianjin Survey Institute was selected as the research object. There are 68 boreholes in this area and 9 layers of mechanical stratification. The parameters are water content, natural gravity, void ratio, liquid limit, plasticity index, liquidity index, compressibility coefficient, compressive modulus, internal friction angle, cohesion and SP index. According to the principle of statistical correlation, the correlation coefficient of geotechnical parameters is calculated. According to the correlation coefficient, the law of geotechnical parameters is obtained.

  7. Data Science Programs in U.S. Higher Education: An Exploratory Content Analysis of Program Description, Curriculum Structure, and Course Focus

    Science.gov (United States)

    Tang, Rong; Sae-Lim, Watinee

    2016-01-01

    In this study, an exploratory content analysis of 30 randomly selected Data Science (DS) programs from eight disciplines revealed significant gaps in current DS education in the United States. The analysis centers on linguistic patterns of program descriptions, curriculum requirements, and DS course focus as pertaining to key skills and domain…

  8. Analysis and System Design Framework for Infrared Spatial Heterodyne Spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, B.J.; Smith, B.W.; Laubscher, B.E.; Villeneuve, P.V.; Briles, S.D.

    1999-04-05

    The authors present a preliminary analysis and design framework developed for the evaluation and optimization of infrared, Imaging Spatial Heterodyne Spectrometer (SHS) electro-optic systems. Commensurate with conventional interferometric spectrometers, SHS modeling requires an integrated analysis environment for rigorous evaluation of system error propagation due to detection process, detection noise, system motion, retrieval algorithm and calibration algorithm. The analysis tools provide for optimization of critical system parameters and components including : (1) optical aperture, f-number, and spectral transmission, (2) SHS interferometer grating and Littrow parameters, and (3) image plane requirements as well as cold shield, optical filtering, and focal-plane dimensions, pixel dimensions and quantum efficiency, (4) SHS spatial and temporal sampling parameters, and (5) retrieval and calibration algorithm issues.

  9. Socio-Spatial Intelligence: social media and spatial cognition for territorial behavioral analysis.

    Science.gov (United States)

    Luini, Lorenzo P; Cardellicchio, Davide; Felletti, Fulvia; Marucci, Francesco S

    2015-09-01

    Investigative analysts gather data from different sources, especially from social media (SM), in order to shed light on cognitive factors that may explain criminal spatial behavior. A former research shows how tweets can be used to estimate private points of interest. Authors' aim was to demonstrate, as they extend the analysis to a wider statistical base, how social maps and Web applications could be used in investigative analysis and spatial cognition research. A total of 100 Twitter accounts with approximately 250 tweets each were submitted to common geographical techniques (measures such as Convex-Hull, Mean-Center, Median-Center, Standard-Deviation-Ellipse) in order to test the hypothesis that user areas of activity are predictable. Predictions were tested through a set of specific information: clear reference to areas of activity and clear reference about user's residence. Simple algorithms and procedures demonstrated that they could be used to predict where SM users live, giving positive results in about 4/5 cases and giving indications about their home location. In fact, all home positions were found in the Convex-Hull and most of them in the Standard-Deviation-Ellipse. Furthermore, in up to 80% of cases, houses were found within a buffer zone of 1.500 m with Median-Center as centrum (70% using Median-Center as centrum) with a minimum effectiveness threshold of 12-13 tweets. SM may help in studying people mobility and their cognition of space and, moreover, where they live, or their traveling behavior. The processing of geographical data in conjunction with the SM analysis may facilitate the construction of models describing specific behavior of people. The use of geographical information system tools and SM analysis represents an effective approach in order to acquire spatial and territorial information, referred to social relationship. The results may be used successfully in the understanding of social dynamics and for the prevention of criminal behavior.

  10. Validation of the Malay Version of the Parental Bonding Instrument among Malaysian Youths Using Exploratory Factor Analysis

    Science.gov (United States)

    MUHAMMAD, Noor Azimah; SHAMSUDDIN, Khadijah; OMAR, Khairani; SHAH, Shamsul Azhar; MOHD AMIN, Rahmah

    2014-01-01

    Background: Parenting behaviour is culturally sensitive. The aims of this study were (1) to translate the Parental Bonding Instrument into Malay (PBI-M) and (2) to determine its factorial structure and validity among the Malaysian population. Methods: The PBI-M was generated from a standard translation process and comprehension testing. The validation study of the PBI-M was administered to 248 college students aged 18 to 22 years. Results: Participants in the comprehension testing had difficulty understanding negative items. Five translated double negative items were replaced with five positive items with similar meanings. Exploratory factor analysis showed a three-factor model for the PBI-M with acceptable reliability. Four negative items (items 3, 4, 8, and 16) and item 19 were omitted from the final PBI-M list because of incorrect placement or low factor loading (parenting style. Confirmatory factor analysis may further support this finding. Keywords: Malaysia, parenting, questionnaire, validity PMID:25977634

  11. Higher Education End-of-Course Evaluations: Assessing the Psychometric Properties Utilizing Exploratory Factor Analysis and Rasch Modeling Approaches

    Directory of Open Access Journals (Sweden)

    Kelly D. Bradley

    2016-07-01

    Full Text Available This paper offers a critical assessment of the psychometric properties of a standard higher education end-of-course evaluation. Using both exploratory factor analysis (EFA and Rasch modeling, the authors investigate the (a an overall assessment of dimensionality using EFA, (b a secondary assessment of dimensionality using a principal components analysis (PCA of the residuals when the items are fit to the Rasch model, and (c an assessment of item-level properties using item-level statistics provided when the items are fit to the Rasch model. The results support the usage of the scale as a supplement to high-stakes decision making such as tenure. However, the lack of precise targeting of item difficulty to person ability combined with the low person separation index renders rank-ordering professors according to minuscule differences in overall subscale scores a highly questionable practice.

  12. Capacity analysis of spectrum sharing spatial multiplexing MIMO systems

    KAUST Repository

    Yang, Liang

    2014-12-01

    This paper considers a spectrum sharing (SS) multiple-input multiple-output (MIMO) system operating in a Rayleigh fading environment. First the capacity of a single-user SS spatial multiplexing system is investigated in two scenarios that assume different receivers. To explicitly show the capacity scaling law of SS MIMO systems, some approximate capacity expressions for the two scenarios are derived. Next, we extend our analysis to a multiple user system with zero-forcing receivers (ZF) under spatially-independent scheduling and analyze the sum-rate. Furthermore, we provide an asymptotic sum-rate analysis to investigate the effects of different parameters on the multiuser diversity gain. Our results show that the secondary system with a smaller number of transmit antennas Nt and a larger number of receive antennas Nr can achieve higher capacity at lower interference temperature Q, but at high Q the capacity follows the scaling law of the conventional MIMO systems. However, for a ZF SS spatial multiplexing system, the secondary system with small Nt and large Nr can achieve the highest capacity throughout the entire region of Q. For a ZF SS spatial multiplexing system with scheduling, the asymptotic sum-rate scales like Ntlog2(Q(KNtNp-1)/Nt), where Np denotes the number of antennas of the primary receiver and K represents the number of secondary transmitters.

  13. Violence in public transportation: an approach based on spatial analysis.

    Science.gov (United States)

    Sousa, Daiane Castro Bittencourt de; Pitombo, Cira Souza; Rocha, Samille Santos; Salgueiro, Ana Rita; Delgado, Juan Pedro Moreno

    2017-12-11

    To carry out a spatial analysis of the occurrence of acts of violence (specifically robberies) in public transportation, identifying the regions of greater incidence, using geostatistics, and possible causes with the aid of a multicriteria analysis in the Geographic Information System. The unit of analysis is the traffic analysis zone of the survey named Origem-Destino, carried out in Salvador, state of Bahia, in 2013. The robberies recorded by the Department of Public Security of Bahia in 2013 were located and made compatible with the limits of the traffic analysis zones and, later, associated with the respective centroids. After determining the regions with the highest probability of robbery, we carried out a geographic analysis of the possible causes in the region with the highest robbery potential, considering the factors analyzed using a multicriteria analysis in a Geographic Information System environment. The execution of the two steps of this study allowed us to identify areas corresponding to the greater probability of occurrence of robberies in public transportation. In addition, the three most vulnerable road sections (Estrada da Liberdade, Rua Pero Vaz, and Avenida General San Martin) were identified in these areas. In these sections, the factors that most contribute with the potential for robbery in buses are: F1 - proximity to places that facilitate escape, F3 - great movement of persons, and F2 - absence of policing, respectively. Indicator Kriging (geostatistical estimation) can be used to construct a spatial probability surface, which can be a useful tool for the implementation of public policies. The multicriteria analysis in the Geographic Information System environment allowed us to understand the spatial factors related to the phenomenon under analysis.

  14. Psychosocial Problems Among Truant Youth: A Multi-Group, Exploratory Structural Equation Modeling Analysis.

    Science.gov (United States)

    Dembo, Richard; Briones-Robinson, Rhissa; Barrett, Kimberly; Winters, Ken C; Ungaro, Rocio; Karas, Lora; Wareham, Jennifer; Belenko, Steven

    2012-01-01

    Truant youth represent a critical group needing problem-oriented research and involvement in effective services. The limited number of studies on the psychosocial functioning of truant youths have focused on one or a few problem areas, rather than examining co-morbid problem behaviors. The present study addresses the need to examine the interrelationships of multiple domains of psychosocial functioning, including substance involvement, mental health, and delinquency, among truant youth. Exploratory structural equation modeling on baseline data collected on 219 truant youths identified two major factors reflecting psychosocial functioning, and found the factor structure was similar across major sociodemographic subgroups. Further analyses supported the validity of the factor structure. The research and service delivery implications of the findings are discussed.

  15. Fourier mode analysis of source iteration in spatially periodic media

    International Nuclear Information System (INIS)

    Zika, M.R.; Larsen, E.W.

    1998-01-01

    The standard Fourier mode analysis is an indispensable tool when designing acceleration techniques for transport iterations; however, it requires the assumption of a homogeneous infinite medium. For problems of practical interest, material heterogeneities may significantly impact iterative performance. Recent work has applied a Fourier analysis to the discretized two-dimensional transport operator with heterogeneous material properties. The results of these analyses may be difficult to interpret because the heterogeneity effects are inherently coupled to the discretization effects. Here, the authors describe a Fourier analysis of source iteration (SI) that allows the calculation of the eigenvalue spectrum for the one-dimensional continuous transport operator with spatially periodic heterogeneous media

  16. Development and psychometric properties rating scale of “clinical competency evaluation in mental health nurses”: Exploratory factor analysis

    Science.gov (United States)

    Moskoei, Sara; Mohtashami, Jamileh; Ghalenoeei, Mahdie; Nasiri, Maliheh; Tafreshi, Mansoreh Zaghari

    2017-01-01

    Introduction Evaluation of clinical competency in nurses has a distinct importance in healthcare due to its significant impact on improving the quality of patient care and creation of opportunities for professional promotion. This is a psychometric study for development of the “Clinical Competency of Mental Health Nursing”(CCMHN) rating scale. Methods In this methodological research that was conducted in 2015, in Tehran, Iran, the main items were developed after literature review and the validity and reliability of the tool were identified. The face, content (content validity ratio and content validity index) and construct validities were calculated. For face and content validity, experts’ comments were used. Exploratory factor analysis was used to determine the construct validity. The reliability of scale was determined by the internal consistency and inter-rater correlation. The collected data were analyzed by SPSS version 16, using descriptive statistical analysis. Results A scale with 45 items in two parts including Emotional/Moral and Specific Care competencies was developed. Content validity ratio and content validity index were 0.88, 0.97 respectively. Exploratory factor analysis indicated two factors: The first factor with 23.93 eigenvalue and second factor with eigenvalue 2.58. Cronbach’s alpha coefficient for determination of internal consistency was 0.98 and the ICC for confirmation inter-rater correlation was 0.98. Conclusion A scale with 45 items and two areas was developed with appropriate validity and reliability. This scale can be used to assess the clinical competency in nursing students and mental health nurses. PMID:28607650

  17. Mapping the geogenic radon potential: methodology and spatial analysis for central Hungary

    International Nuclear Information System (INIS)

    Szabó, Katalin Zsuzsanna; Jordan, Gyozo; Horváth, Ákos; Szabó, Csaba

    2014-01-01

    A detailed geogenic radon potential (GRP) mapping based on field soil gas radon and soil gas permeability measurements was carried out in this study. A conventional continuous variable approach was used in this study for GRP determination and to test its applicability to the selected area of Hungary. Spatial pattern of soil gas radon concentration, soil permeability and GRP and the relationship between geological formations and these parameters were studied by performing detailed spatial analysis. Exploratory data analysis revealed that higher soil gas radon activity concentration and GRP characterizes the mountains and hills than the plains. The highest values were found in the proluvial–deluvial sediments, rock debris on the downhill slopes eroded from hills. Among the Quaternary sediments, which characterize the study area, the fluvial sediment has the highest values, which are also located in the hilly areas. The lowest values were found in the plain areas covered by drift sand, fluvioeolic sand, fluvial sand and loess. As a conclusion, radon is related to the sediment cycle in the study area. A geogenic radon risk map was created, which assists human health risk assessment and risk reduction since it indicates the potential of the source of indoor radon. The map shows that low and medium geogenic radon potential characterizes the study area in central Hungary. High risk occurs only locally. The results reveal that Quaternary sediments are inhomogeneous from a radon point of view, fluvial sediment has medium GRP, whereas the other rock formations such as drift sand, fluioeolic sand, fluvial sand and loess, found in the study area, have low GRP. - Highlights: • First geogenic radon potential map in Hungary. • Low and medium GRP characterizes the study area (Middle Hungary). • Mainly quaternary sediments characterizes the study area. • Radon is related to the erosion and deposition of the sediment cycle

  18. Spatial Analysis of Depots for Advanced Biomass Processing

    Energy Technology Data Exchange (ETDEWEB)

    Hilliard, Michael R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Brandt, Craig C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Webb, Erin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sokhansanj, Shahabaddine [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Eaton, Laurence M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Martinez Gonzalez, Maria I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-09-01

    The objective of this work was to perform a spatial analysis of the total feedstock cost at the conversion reactor for biomass supplied by a conventional system and an advanced system with depots to densify biomass into pellets. From these cost estimates, the conditions (feedstock cost and availability) for which advanced processing depots make it possible to achieve cost and volume targets can be identified.

  19. An Exploratory Factor Analysis of Coping Styles and Relationship to Depression Among a Sample of Homeless Youth.

    Science.gov (United States)

    Brown, Samantha M; Begun, Stephanie; Bender, Kimberly; Ferguson, Kristin M; Thompson, Sanna J

    2015-10-01

    The extent to which measures of coping adequately capture the ways that homeless youth cope with challenges, and the influence these coping styles have on mental health outcomes, is largely absent from the literature. This study tests the factor structure of the Coping Scale using Exploratory Factor Analysis (EFA) and then investigates the relationship between coping styles and depression using hierarchical logistic regression with data from 201 homeless youth. Results of the EFA indicate a 3-factor structure of coping, which includes active, avoidant, and social coping styles. Results of the hierarchical logistic regression show that homeless youth who engage in greater avoidant coping are at increased risk of meeting criteria for major depressive disorder. Findings provide insight into the utility of a preliminary tool for assessing homeless youths' coping styles. Such assessment may identify malleable risk factors that could be addressed by service providers to help prevent mental health problems.

  20. Using exploratory factor analysis to explore personal attitudes influencing the people-plant relationship in Danish workplaces

    DEFF Research Database (Denmark)

    Thomsen, Jane Dyrhauge; Müller, Renate; Sønderstrup-Andersen, Hans H. K.

    2012-01-01

    was 0.79 and 0.93 for the second factor. These two factors form an interesting platform from which the question of how personal attitudes are influencing the people-plant relationship at Danish workplaces can be investigated further. However, it should be noted that the results reported here......In this paper we present the results of an exploratory factor analysis (EFA) investigating the attitudes of 37 Danish employees towards ornamental plants at their workplace. The material used was collected as part of a larger qualitative case study exploring people-plant relationships in Danish....... All the items were formulated as statements to which the respondents had to state the extent to which they agreed. The possible answers were built around a 5-point Likert scale in the range from “not at all” to “to a very high extent”. By an EFA it was analysed how many factors the scale actually...

  1. Using Exploratory Factor Analysis to Explore Personal Attitudes Influencing the People-Plant Relationship in Danish Workplaces

    DEFF Research Database (Denmark)

    Sønderstrup-Andersen, Hans H. K.; Thomsen, Jane Dyrhauge; Müller, Renate

    2012-01-01

    office workplaces. A paper-pencil questionnaire was developed in order to collect demographical information about the employees at the workplaces under investigation. A scale composed of 13 items regarding the attitudes towards ornamental plants at the workplace was also included in the questionnaire......In this paper we present the results of an exploratory factor analysis (EFA) investigating the attitudes of 37 Danish employees towards ornamental plants at their workplace. The material used was collected as part of a larger qualitative case study exploring people-plant relationships in Danish...... was 0.79 and 0.93 for the second factor. These two factors form an interesting platform from which the question of how personal attitudes are influencing the people-plant relationship at Danish workplaces can be investigated further. However, it should be noted that the results reported here...

  2. Using exploratory factor analysis to explore personal attitudes influencing the people-plant relationship in Danish workplaces

    DEFF Research Database (Denmark)

    Thomsen, Jane Dyrhauge; Müller, Renate; Sønderstrup-Andersen, Hans H. K.

    2012-01-01

    In this paper we present the results of an exploratory factor analysis (EFA) investigating the attitudes of 37 Danish employees towards ornamental plants at their workplace. The material used was collected as part of a larger qualitative case study exploring people-plant relationships in Danish....... All the items were formulated as statements to which the respondents had to state the extent to which they agreed. The possible answers were built around a 5-point Likert scale in the range from “not at all” to “to a very high extent”. By an EFA it was analysed how many factors the scale actually...... measured. The result identified two factors: one regarding whether ornamental plants were wanted in the workplace or not; and one regarding whether ornamental plants were perceived as beneficial in relation to general well-being at the workplace or not. The Cronbach alpha coefficient for the first factor...

  3. Using Exploratory Factor Analysis to Explore Personal Attitudes Influencing the People-Plant Relationship in Danish Workplaces

    DEFF Research Database (Denmark)

    Sønderstrup-Andersen, Hans H. K.; Thomsen, Jane Dyrhauge; Müller, Renate

    2012-01-01

    In this paper we present the results of an exploratory factor analysis (EFA) investigating the attitudes of 37 Danish employees towards ornamental plants at their workplace. The material used was collected as part of a larger qualitative case study exploring people-plant relationships in Danish....... All the items were formulated as statements to which the respondents had to state the extent to which they agreed. The possible answers were built around a 5-point Likert scale in the range from “not at all” to “to a very high extent”. By an EFA it was analysed how many factors the scale actually...... measured. The result identified two factors: one regarding whether ornamental plants were wanted in the workplace or not; and one regarding whether ornamental plants were perceived as beneficial in relation to general well-being at the workplace or not. The Cronbach alpha coefficient for the first factor...

  4. Spatial Factor Analysis for Aerosol Optical Depth in Metropolises in China with Regard to Spatial Heterogeneity

    Directory of Open Access Journals (Sweden)

    Hui Shi

    2018-04-01

    Full Text Available A substantial number of studies have analyzed how driving factors impact aerosols, but they have been little concerned with the spatial heterogeneity of aerosols and the factors that impact aerosols. The spatial distributions of the aerosol optical depth (AOD retrieved by Moderate Resolution Imaging Spectrometer (MODIS data at 550-nm and 3-km resolution for three highly developed metropolises, the Beijing-Tianjin-Hebei (BTH region, the Yangtze River Delta (YRD, and the Pearl River Delta (PRD, in China during 2015 were analyzed. Different degrees of spatial heterogeneity of the AOD were found, which were indexed by Moran’s I index giving values of 0.940, 0.715, and 0.680 in BTH, YRD, and PRD, respectively. For the spatial heterogeneity, geographically weighted regression (GWR was employed to carry out a spatial factor analysis, where terrain, climate condition, urban development, and vegetation coverage were taken as the potential driving factors. The results of the GWR imply varying relationships between the AOD and the factors. The results were generally consistent with existing studies, but the results suggest the following: (1 Elevation increase would more likely lead to a strong negative impact on aerosols (with most of the coefficients ranging from −1.5~0 in the BTH, −1.5~0 in the YRD, and −1~0 in the PRD in the places with greater elevations where the R-squared values are always larger than 0.5. However, the variation of elevations cannot explain the variation of aerosols in the places with relatively low elevations (with R-squared values approximately 0.1, ranging from 0 to 0.3, and approximately 0.1 in the BTH, YRD, and PRD, such as urban areas in the BTH and YRD. (2 The density of the built-up areas made a strong and positive impact on aerosols in the urban areas of the BTH (R-squared larger than 0.5, while the R-squared dropped to 0.1 in the places far away from the urban areas. (3 The vegetation coverage led to a stronger

  5. Using exploratory factor analysis of food frequency questionnaires to identify dietary patterns among Yup’ik People

    Science.gov (United States)

    Ryman, Tove K.; Austin, Melissa A.; Hopkins, Scarlett; Philip, Jacques; O’Brien, Diane; Thummel, Kenneth; Boyer, Bert B.

    2012-01-01

    Objective A food frequency questionnaire (FFQ) developed by the Center for Alaska Native Health Research for studies in Yup’ik people includes market foods and subsistence foods such as moose, seal, waterfowl and salmon that may be related to disease risk. Because the FFQ contains >100 food items, we sought to characterize dietary patterns more simply for use in ongoing pharmacogenomics studies. Design Exploratory factor analysis was used to derive a small number of “factors” that explain a substantial amount of the variation in the Yup’ik diet. We estimated factor scores and measured associations with demographic characteristics and biomarkers. Setting Southwest Alaska, US Subjects 358 Yup’ik people, ≥ 18 years Results We identified 3 factors that each accounted for ≥10% of the common variance: the first characterized by “processed foods” (e.g., salty snacks, sweetened cereals); the second by “fruits and vegetables” (e.g., fresh citrus, potato salad); and the third by “subsistence foods” (seal or walrus soup, non-oily fish). Participants from coastal communities had higher values for the “subsistence” factor, whereas participants from inland communities had higher values for the “fruits and vegetables” factor. A biomarker of marine intake, δ 15N, was correlated with the “subsistence” factor, whereas a biomarker of corn and sugar-cane based market food intake, δ 13C, was correlated with “processed foods”. Conclusions This exploratory factor analysis identified 3 factors that appear to reflect dietary patterns among Yup’ik based on associations with participant characteristics and biomarkers. These factors will be useful for chronic disease studies in this population. PMID:23290469

  6. Spatial energy market risk analysis using the semivariance risk measure

    International Nuclear Information System (INIS)

    Yu, Zuwei

    2007-01-01

    The paper concentrates on the analysis of semivariance (SV) as a market risk measure for market risk analysis of mean-semivariance (MSV) portfolios. The advantage of MSV over variance as a risk measure is that MSV provides a more logical measure of risk than the MV method. In addition, the relationship of the SV with the lower partial movements is discussed. A spatial risk model is proposed as a basis of risk assessment for short-term energy markets. Transaction costs and other practical constraints are also included. A case study is provided to show the successful application of the model. (author)

  7. Spectral theory and nonlinear analysis with applications to spatial ecology

    CERN Document Server

    Cano-Casanova, S; Mora-Corral , C

    2005-01-01

    This volume details some of the latest advances in spectral theory and nonlinear analysis through various cutting-edge theories on algebraic multiplicities, global bifurcation theory, non-linear Schrödinger equations, non-linear boundary value problems, large solutions, metasolutions, dynamical systems, and applications to spatial ecology. The main scope of the book is bringing together a series of topics that have evolved separately during the last decades around the common denominator of spectral theory and nonlinear analysis - from the most abstract developments up to the most concrete applications to population dynamics and socio-biology - in an effort to fill the existing gaps between these fields.

  8. An exploratory analysis of the relationship between ambient ozone and particulate matter concentrations during early pregnancy and selected birth defects in Texas

    Science.gov (United States)

    Background: Associations between ozone (O3) and fine particulate matter (PM2.5) concentrations and birth outcomes have been previously demonstrated. We perform an exploratory analysis of O3 and PM2.5 concentrations during early pregnancy and multiple types of birth defects. Met...

  9. Airborne electromagnetics data interactive visualisation and exploratory data analysis using Cloud technologies

    Science.gov (United States)

    Golodoniuc, P.; Davis, A. C.; Klump, J. F.

    2017-12-01

    Electromagnetic exploration techniques are extensively used for remote detection and measurement of subsurface electrical conductivity structures for a variety of geophysical applications such as mineral exploration and groundwater detection. The Electromagnetic Applications group in the Mineral Resources business unit of CSIRO heavily relies upon the use of airborne electromagnetic (AEM) data for the development of new exploration methods. AEM data, which are often originally acquired for green- or brown-fields exploration for minerals, can be re-used for groundwater resource detection in the near-surface. This makes AEM data potentially useful beyond their initial purpose for decades into the future. Increasingly, AEM data are also used as a primary mapping tool for groundwater resources. With surveys ranging from under 1000 km to tens of thousands of km in total length, AEM data are spatially and temporally dense. Sounding stations are often sampled every 0.2 seconds, with about 30-50 measurements taken at each site, resulting in a spacing of measurements along the flight lines of approximately 20­-50 metres. This means that typical AEM surveys can easily have on the order of millions of individual stations, with tens of millions of measurements. AEM data needs to be examined for data quality before it can be inverted into conductivity-depth information. Data, which is gathered in survey transects or lines, is examined both along the line, in a plan view and for the transient decay of the electromagnetic signal of individual stations before noise artefacts can be removed. The complexity of the data, its size and dimensionality require efficient tools that support interactive visual data analysis and allows easy navigation through the dataset. A suite of numerical algorithms for data quality assurance facilitates this process through efficient visualisations and data quality metrics. The extensible architecture of the toolkit allows application of custom

  10. Analysis of the spatial distribution of dengue cases in the city of Rio de Janeiro, 2011 and 2012

    Directory of Open Access Journals (Sweden)

    Silvia Carvalho

    2017-08-01

    Full Text Available ABSTRACT OBJECTIVE Analyze the spatial distribution of classical dengue and severe dengue cases in the city of Rio de Janeiro. METHODS Exploratory study, considering cases of classical dengue and severe dengue with laboratory confirmation of the infection in the city of Rio de Janeiro during the years 2011/2012. The georeferencing technique was applied for the cases notified in the Notification Increase Information System in the period of 2011 and 2012. For this process, the fields “street” and “number” were used. The ArcGis10 program’s Geocoding tool’s automatic process was performed. The spatial analysis was done through the kernel density estimator. RESULTS Kernel density pointed out hotspots for classic dengue that did not coincide geographically with severe dengue and were in or near favelas. The kernel ratio did not show a notable change in the spatial distribution pattern observed in the kernel density analysis. The georeferencing process showed a loss of 41% of classic dengue registries and 17% of severe dengue registries due to the address in the Notification Increase Information System form. CONCLUSIONS The hotspots near the favelas suggest that the social vulnerability of these localities can be an influencing factor for the occurrence of this aggravation since there is a deficiency of the supply and access to essential goods and services for the population. To reduce this vulnerability, interventions must be related to macroeconomic policies.

  11. Personal Belief Exemptions to Vaccination in California: A Spatial Analysis.

    Science.gov (United States)

    Carrel, Margaret; Bitterman, Patrick

    2015-07-01

    School vaccination rates in California have fallen as more parents opt for personal belief exemptions (PBEs) for their children. Our goals were to (1) spatially analyze PBE patterns over time, (2) determine correlates of PBEs, and (3) examine their spatial overlap with personal medical exemptions (PMEs). PBE and PME data for California kindergarten classes from the 2001/2002 to 2013/2014 school years were matched to the locations of schools. Nonspatial clustering algorithms were implemented to group 5147 schools according to their trends in PBE percentages among kindergartners. Cluster assignments were mapped and hotspot analysis was performed to find areas in California where schools sharing trends in PBEs over time were colocated. Schools were further associated both with school-level data on minority enrollment and free and reduced price lunch participation and with charter/private and rural/urban status. Spatial regression was implemented to determine which school-level variables were correlated with PBE rates in the 2013/2014 school year. Distinct spatial patterns are observed in California when PBE cluster assignments are mapped. Results indicate that schools belonging to the "high PBE" cluster are spatially buffered from those in "low PBE" areas by "medium PBE" schools. Further, PBE rates are positively associated with the percentage of white students, charter status, and private schools. Hotspots of high PBE schools are in some cases colocated with schools that have elevated PME rates, prompting concern that herd immunity is diminished for school populations where students have no choice but to remain unvaccinated. Copyright © 2015 by the American Academy of Pediatrics.

  12. Spatial heterogeneity analysis of brain activation in fMRI

    Directory of Open Access Journals (Sweden)

    Lalit Gupta

    2014-01-01

    Full Text Available In many brain diseases it can be qualitatively observed that spatial patterns in blood oxygenation level dependent (BOLD activation maps appear more (diffusively distributed than in healthy controls. However, measures that can quantitatively characterize this spatial distributiveness in individual subjects are lacking. In this study, we propose a number of spatial heterogeneity measures to characterize brain activation maps. The proposed methods focus on different aspects of heterogeneity, including the shape (compactness, complexity in the distribution of activated regions (fractal dimension and co-occurrence matrix, and gappiness between activated regions (lacunarity. To this end, functional MRI derived activation maps of a language and a motor task were obtained in language impaired children with (Rolandic epilepsy and compared to age-matched healthy controls. Group analysis of the activation maps revealed no significant differences between patients and controls for both tasks. However, for the language task the activation maps in patients appeared more heterogeneous than in controls. Lacunarity was the best measure to discriminate activation patterns of patients from controls (sensitivity 74%, specificity 70% and illustrates the increased irregularity of gaps between activated regions in patients. The combination of heterogeneity measures and a support vector machine approach yielded further increase in sensitivity and specificity to 78% and 80%, respectively. This illustrates that activation distributions in impaired brains can be complex and more heterogeneous than in normal brains and cannot be captured fully by a single quantity. In conclusion, heterogeneity analysis has potential to robustly characterize the increased distributiveness of brain activation in individual patients.

  13. Innovation and adoption of energy efficient technologies: An exploratory analysis of Italian primary metal manufacturing SMEs

    International Nuclear Information System (INIS)

    Trianni, Andrea; Cagno, Enrico; Worrell, Ernst

    2013-01-01

    Additional efforts will be needed by European countries to improve the energy efficiency, as with current trends the 20% objective will be missed. Small and medium-sized enterprises (SMEs) manufacturing sector is a promising field, as SMEs are less energy-efficient than larger enterprises. Several studies investigated the barriers to the diffusion of technologies and practices for industrial energy efficiency, but little attention has been paid to understand the factors affecting the perception of such barriers by SMEs. In this multiple case-study, we have investigated 20 Primary Metal manufacturing SMEs in Northern Italy. Economic and information barriers are perceived as the major issues. Interestingly, firm's size, innovativeness of the market in which enterprises operate, as well as product and process innovation are factors affecting barriers to energy efficiency. Differences have been observed within SMEs, especially for information and competence-related barriers. In particular, a more innovative external context in which enterprises operate and a greater production process complexity seem to reduce barriers. Moreover, more product innovative enterprises seem to have a lower perception of behavioral and technology-related barriers. The results of this exploratory investigation provide useful suggestions for policy design and further research on industrial energy efficiency. - highlights: • Economic and Information emerge as the most relevant barriers to energy efficiency. • Market, product and process innovation seem relevant factors affecting barriers. • Firm's size is a factor affecting barriers' perception

  14. Adolescent athletic participation and nonmedical Adderall use: an exploratory analysis of a performance-enhancing drug.

    Science.gov (United States)

    Veliz, Philip; Boyd, Carol; McCabe, Sean Esteban

    2013-09-01

    A primary motive for adolescents and young adults to nonmedically use prescription stimulants is to help them study. Adolescents and young adults are using prescription stimulants, such as Adderall (amphetamine aspartate, amphetamine sulfate, dextroamphetamine saccharate, dextroamphetamine sulfate), as performance enhancers in certain social domains, including academics and sports. The purpose of this exploratory study was to examine the nonmedical use of Adderall (a commonly prescribed stimulant used nonmedically) among adolescents who participate in competitive sports. The Monitoring the Future survey for 2010 and 2011, a representative sample of 8th- and 10th-grade students, surveyed involvement in competitive sports and nonmedical Adderall use among 21,137 adolescents. Past-year nonmedical use of Adderall served as the main outcome measure. Logistic regression analyses were run to examine whether sports participation in general and involvement in different types of competitive sports participation were associated with past-year nonmedical use of Adderall among males and females. The odds of past-year nonmedical use of Adderall among males were higher for male respondents who participated in lacrosse (adjusted odds ratio [AOR] = 2.52, 95% CI [1.20, 5.29]) and wrestling (AOR = 1.74, 95% CI [1.01, 2.98]). However, no particular sport among females was found to be associated with past-year nonmedical use of Adderall. Certain extracurricular activities, such as high-contact sports, may influence male participants to misuse prescription stimulants as performance enhancers either on or off the playing field.

  15. LDSScanner: Exploratory Analysis of Low-Dimensional Structures in High-Dimensional Datasets.

    Science.gov (United States)

    Xia, Jiazhi; Ye, Fenjin; Chen, Wei; Wang, Yusi; Chen, Weifeng; Ma, Yuxin; Tung, Anthony K H

    2018-01-01

    Many approaches for analyzing a high-dimensional dataset assume that the dataset contains specific structures, e.g., clusters in linear subspaces or non-linear manifolds. This yields a trial-and-error process to verify the appropriate model and parameters. This paper contributes an exploratory interface that supports visual identification of low-dimensional structures in a high-dimensional dataset, and facilitates the optimized selection of data models and configurations. Our key idea is to abstract a set of global and local feature descriptors from the neighborhood graph-based representation of the latent low-dimensional structure, such as pairwise geodesic distance (GD) among points and pairwise local tangent space divergence (LTSD) among pointwise local tangent spaces (LTS). We propose a new LTSD-GD view, which is constructed by mapping LTSD and GD to the axis and axis using 1D multidimensional scaling, respectively. Unlike traditional dimensionality reduction methods that preserve various kinds of distances among points, the LTSD-GD view presents the distribution of pointwise LTS ( axis) and the variation of LTS in structures (the combination of axis and axis). We design and implement a suite of visual tools for navigating and reasoning about intrinsic structures of a high-dimensional dataset. Three case studies verify the effectiveness of our approach.

  16. Spatial analysis to identify disparities in Philippine public school facilities

    Directory of Open Access Journals (Sweden)

    Ligaya Leah Figueroa

    2016-01-01

    Full Text Available This paper addresses the issues that affect school building conditions as a case study of the Philippines. Geographic information systems were utilized to investigate the allocation of public school resources and the extent of disparity in education facilities among 75 Philippine provinces. Four clusters of the provinces were identified by applying spatial statistics and regionalization techniques to the public school data. Overall, the building conditions are of high quality in the northern provinces. The greater region of the capital is overcrowded but well maintained. The eastern seaboard region and the southern provinces have poor conditions due to frequent natural calamities and the prolonged civil unrest, respectively. Since the spatial analysis result shows that the school building requirements are largely unmet, some recommendations are proposed so that they can be implemented by the government in order to improve the school facilities and mitigate the existing disparities among the four clusters of the Philippines.

  17. Spatially resolved fish population analysis for designing MPAs

    DEFF Research Database (Denmark)

    Christensen, Asbjørn; Mosegaard, Henrik; Jensen, Henrik

    2009-01-01

    The sandeel population analysis model (SPAM) is presented as a simulation tool for exploring the efficiency of Marine Protected Areas (MPAs) for sandeel stocks. SPAM simulates spatially resolved sandeel population distributions, based on a high-resolution map of all fishery-established sandbank....... The SPAM framework was tested using ICES statistical rectangle 37F2 as an MPA, and the impact on sandeel populations within the MPA and neighbouring habitats was investigated. Increased larval spillover compensated for lost catches inside the MPA. The temporal and spatial scales of stock response to MPAs...... demonstrated that ecosystem self-regulation must be included when modelling the efficiency of MPAs, and for lesser sandeel, that self-regulation partially counteracts the benefits of a fishing sanctuary. The use of realistic habitat connectivity is critical for both qualitative and quantitative MPA assessment...

  18. Graduated driver licensing and motor vehicle crashes involving teenage drivers: an exploratory age-stratified meta-analysis.

    Science.gov (United States)

    Zhu, Motao; Cummings, Peter; Chu, Haitao; Coben, Jeffrey H; Li, Guohua

    2013-02-01

    Graduated Driver Licensing (GDL) has been implemented in Australia, Canada, New Zealand, USA and Israel. We conducted an exploratory summary of available data to estimate whether GDL effects varied with age. We searched MEDLINE and other sources from 1991-2011. GDL evaluation studies with crashes resulting in injuries or deaths were eligible. They had to provide age-specific incidence rate ratios with CI or information for calculating these quantities. We included studies from individual states or provinces, but excluded national studies. We examined rates based on person-years, not license-years. Of 1397 papers, 144 were screened by abstract and 47 were reviewed. Twelve studies from 11 US states and one Canadian province were selected for meta-analysis for age 16, eight were selected for age 17, and four for age 18. Adjusted rate ratios were pooled using random effects models. The pooled adjusted rate ratios for the association of GDL presence with crash rates was 0.78 (95% CI 0.72 to 0.84) for age 16 years, 0.94 (95% CI 0.93 to 0.96) for 17 and 1.00 (95% CI 0.95 to 1.04) for 18. The difference between these three rate ratios was statistically significant: p<0.001. GDL policies were associated with a 22% reduction in crash rates among 16-year-old drivers, but only a 6% reduction for 17-year-old drivers. GDL showed no association with crashes among 18-year-old drivers. Because we had few studies to summarise, particularly for older adolescents, our findings should be considered exploratory.

  19. SPATIAL ANALYSIS TO SUPPORT GEOGRAPHIC TARGETING OF GENOTYPES TO ENVIRONMENTS

    Directory of Open Access Journals (Sweden)

    Glenn eHyman

    2013-03-01

    Full Text Available Crop improvement efforts have benefited greatly from advances in available data, computing technology and methods for targeting genotypes to environments. These advances support the analysis of genotype by environment interactions to understand how well a genotype adapts to environmental conditions. This paper reviews the use of spatial analysis to support crop improvement research aimed at matching genotypes to their most appropriate environmental niches. Better data sets are now available on soils, weather and climate, elevation, vegetation, crop distribution and local conditions where genotypes are tested in experimental trial sites. The improved data are now combined with spatial analysis methods to compare environmental conditions across sites, create agro-ecological region maps and assess environment change. Climate, elevation and vegetation data sets are now widely available, supporting analyses that were much more difficult even five or ten years ago. While detailed soil data for many parts of the world remains difficult to acquire for crop improvement studies, new advances in digital soil mapping are likely to improve our capacity. Site analysis and matching and regional targeting methods have advanced in parallel to data and technology improvements. All these developments have increased our capacity to link genotype to phenotype and point to a vast potential to improve crop adaptation efforts.

  20. An exploratory analysis of fear of recurrence among African-American breast cancer survivors.

    Science.gov (United States)

    Taylor, Teletia R; Huntley, Edward D; Sween, Jennifer; Makambi, Kepher; Mellman, Thomas A; Williams, Carla D; Carter-Nolan, Pamela; Frederick, Wayne

    2012-09-01

    Fear of recurrence (FOR) is a psychological concern that has been studied extensively in cancer survivors but has not been adequately examined in African-American breast cancer survivors. This exploratory study describes the extent and nature of FOR in African-American breast cancer survivors. FOR is examined in relation to socio-demographic characteristics, treatment-related characteristics, psychological distress, and quality of life (QOL). Participants completed questionnaires assessing FOR, psychological distress, QOL, and demographic and treatment characteristics. Pearson r correlations, t tests, and ANOVAs were used to determine the association between FOR and demographic and treatment-related characteristics. Hierarchical multiple regression models were performed to investigate the degree to which FOR dimensions account for the variance in QOL and psychological distress. Fifty-one African-American breast cancer survivors participated in this study. The mean age of participants was 64.24 (SD = 12.3). Overall fears as well as concerns about death and health were rated as low to moderate. Role worries and womanhood worries were very low. Inverse relationships were observed between age and FOR dimensions. FOR was positively correlated with measures of psychological distress and negatively correlated with QOL. FOR significantly accounted for a portion of the variance in QOL and distress after controlling for other variables. This study suggests that African-American women in this sample demonstrated some degree of FOR. Results indicate that FOR among African-American breast cancer survivors decreases with age and time since diagnosis and co-occurs with psychological distress as well as diminished quality of life.

  1. Measuring Practicing Clinicians' Information Literacy. An Exploratory Analysis in the Context of Panel Management.

    Science.gov (United States)

    Dixon, Brian E; Barboza, Katherine; Jensen, Ashley E; Bennett, Katelyn J; Sherman, Scott E; Schwartz, Mark D

    2017-02-15

    As healthcare moves towards technology-driven population health management, clinicians must adopt complex digital platforms to access health information and document care. This study explored information literacy, a set of skills required to effectively navigate population health information systems, among primary care providers in one Veterans' Affairs (VA) medical center. Information literacy was assessed during an 8-month randomized trial that tested a population health (panel) management intervention. Providers were asked about their use and comfort with two VA digital tools for panel management at baseline, 16 weeks, and post-intervention. An 8-item scale (range 0-40) was used to measure information literacy (Cronbach's α=0.84). Scores between study arms and provider types were compared using paired t-tests and ANOVAs. Associations between self-reported digital tool use and information literacy were measured via Pearson's correlations. Providers showed moderate levels of information literacy (M= 27.4, SD 6.5). There were no significant differences in mean information literacy between physicians (M=26.4, SD 6.7) and nurses (M=30.5, SD 5.2, p=0.57 for difference), or between intervention (M=28.4, SD 6.5) and control groups (M=25.1, SD 6.2, p=0.12 for difference). Information literacy was correlated with higher rates of self-reported information system usage (r=0.547, p=0.001). Clinicians identified data access, accuracy, and interpretability as potential information literacy barriers. While exploratory in nature, cautioning generalizability, the study suggests that measuring and improving clinicians' information literacy may play a significant role in the implementation and use of digital information tools, as these tools are rapidly being deployed to enhance communication among care teams, improve health care outcomes, and reduce overall costs.

  2. Sex Life Satisfaction in Sub-Saharan Africa: A Descriptive and Exploratory Analysis.

    Science.gov (United States)

    Cranney, Stephen

    2017-10-01

    Nearly all of the sex life satisfaction literature has dealt with developed-country settings, and nothing has been published on sex life satisfaction in sub-Saharan Africa. Not only is sub-Saharan African a substantively relevant area in its own right, but it also provides a useful point of comparison for patterns and relations found in developed-world contexts. A brief descriptive and exploratory study of sex life satisfaction in sub-Saharan Africa was conducted using the World Gallup Poll, a dataset with representative sex life satisfaction data for 31 countries and 25,483 cases. In general, there was little variation in weighted averages across countries, and most of the samples surveyed were satisfied with their sex lives, with the modal score being a perfect 10. Furthermore, what variation did exist could not be attributed to level of economic development or gender inequality. Within countries, sociodemographic associations generally comported with patterns found in other contexts: income, education, and being partnered were generally associated with sex life satisfaction, and for two of the four UN subregions (West Africa and East Africa), males were significantly more satisfied with their sex lives than women. The relationship with age demonstrated a curvilinear relationship, with the peak age of sexual satisfaction in the late 20s to early 30s depending on the geographic region. The age pattern was not due to health differences, but combining estimators after a seemingly unrelated regression suggests that 4-12% of the effect of income on sex life satisfaction was attributable to better health. In general, religiosity and perceived gravity of the HIV/AIDS problem in one's country were not significantly related to sexual satisfaction.

  3. Online illegal drug use information: an exploratory analysis of drug-related website viewing by adolescents.

    Science.gov (United States)

    Belenko, Steven; Dugosh, Karen L; Lynch, Kevin; Mericle, Amy A; Pich, Michele; Forman, Robert F

    2009-01-01

    Given the uncertain effects of antidrug media campaigns, and the ease of finding online illegal drug information, research is needed on the Internet role in disseminating drug information to youths. This exploratory study analyzes National Survey of Parents and Youth (NSPY) data on drug website viewing among 12-18 year olds (N = 7,145). Approximately 10.4% reported drug-related website exposure: 5.4% viewed only websites that communicated how to avoid drugs or bad things about drugs (antidrug websites); 1.7% only viewed websites that communicated how to use drugs and good things about drugs (prodrug websites); and 3.2% viewed both types of websites. The low rates of viewing antidrug websites occurred despite efforts in the National Youth Antidrug Media Campaign (NYAMC) to encourage youths to visit such websites. Prodrug website viewers had used inhalants and been offered marijuana, perceived little risk in trying marijuana, intended to use marijuana, had close friends who used drugs, reported low parental monitoring, and had been exposed to antidrug media messages. Viewing antidrug websites was related to gender, income, likelihood of using marijuana in the next 12 months, having close friends who use drugs and talking to friends about avoiding drugs, parental monitoring, and drug prevention exposure. Prior prevention exposure increased drug website viewing overall, perhaps by increasing general curiosity about drugs. Because adolescents increasingly seek health information online, research is needed on how they use the Internet as a drug information source, the temporal relationships of prevention exposure and drug website viewing, and the effects of viewing prodrug websites on drug risk.

  4. Spatial Dependence and Heterogeneity in Bayesian Factor Analysis : A Cross-National Investigation of Schwartz Values

    NARCIS (Netherlands)

    Stakhovych, Stanislav; Bijmolt, Tammo H. A.; Wedel, Michel

    2012-01-01

    In this article, we present a Bayesian spatial factor analysis model. We extend previous work on confirmatory factor analysis by including geographically distributed latent variables and accounting for heterogeneity and spatial autocorrelation. The simulation study shows excellent recovery of the

  5. An analysis of spatial representativeness of air temperature monitoring stations

    Science.gov (United States)

    Liu, Suhua; Su, Hongbo; Tian, Jing; Wang, Weizhen

    2018-05-01

    Surface air temperature is an essential variable for monitoring the atmosphere, and it is generally acquired at meteorological stations that can provide information about only a small area within an r m radius ( r-neighborhood) of the station, which is called the representable radius. In studies on a local scale, ground-based observations of surface air temperatures obtained from scattered stations are usually interpolated using a variety of methods without ascertaining their effectiveness. Thus, it is necessary to evaluate the spatial representativeness of ground-based observations of surface air temperature before conducting studies on a local scale. The present study used remote sensing data to estimate the spatial distribution of surface air temperature using the advection-energy balance for air temperature (ADEBAT) model. Two target stations in the study area were selected to conduct an analysis of spatial representativeness. The results showed that one station (AWS 7) had a representable radius of about 400 m with a possible error of less than 1 K, while the other station (AWS 16) had the radius of about 250 m. The representable radius was large when the heterogeneity of land cover around the station was small.

  6. Spatial Analysis Along Networks Statistical and Computational Methods

    CERN Document Server

    Okabe, Atsuyuki

    2012-01-01

    In the real world, there are numerous and various events that occur on and alongside networks, including the occurrence of traffic accidents on highways, the location of stores alongside roads, the incidence of crime on streets and the contamination along rivers. In order to carry out analyses of those events, the researcher needs to be familiar with a range of specific techniques. Spatial Analysis Along Networks provides a practical guide to the necessary statistical techniques and their computational implementation. Each chapter illustrates a specific technique, from Stochastic Point Process

  7. An exploratory digital analysis of the early years of G. Stanley Hall's American Journal of Psychology and Pedagogical Seminary.

    Science.gov (United States)

    Young, Jacy L; Green, Christopher D

    2013-11-01

    In this article, we present the results of an exploratory digital analysis of the contents of the two journals founded in the late 19th century by American psychologist G. Stanley Hall. Using the methods of the increasingly popular digital humanities, some key attributes of the American Journal of Psychology (AJP) and the Pedagogical Seminary (PS) are identified. Our analysis reaffirms some of Hall's explicit aims for the two periodicals, while also revealing a number of other features of the journals, as well as of the people who published within their pages, the methodologies they employed, and the institutions at which they worked. Notably, despite Hall's intent that his psychological journal be strictly an outlet for scientific research, the journal-like its sister pedagogically focused publication-included an array of methodologically diverse research. The multiplicity of research styles that characterize the content of Hall's journals in their initial years is, in part, a consequence of individual researchers at times crossing methodological lines and producing a diverse body of research. Along with such variety within each periodical, it is evident that the line between content appropriate to one periodical rather than the other was fluid rather than absolute. The full results of this digitally informed analysis of Hall's two journals suggest a number of novel avenues for future research and demonstrate the utility of digital methods as applied to the history of psychology. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

  8. Modifying the Autism Spectrum Rating Scale (6-18 years) to a Chinese Context: An Exploratory Factor Analysis.

    Science.gov (United States)

    Zhou, Hao; Zhang, Lili; Luo, Xuerong; Wu, Lijie; Zou, Xiaobing; Xia, Kun; Wang, Yimin; Xu, Xiu; Ge, Xiaoling; Jiang, Yong-Hui; Fombonne, Eric; Yan, Weili; Wang, Yi

    2017-04-01

    The purpose of this study was to explore the psychometric properties of the Chinese version of the autism spectrum rating scale (ASRS). We recruited 1,625 community-based children and 211 autism spectrum disorder (ASD) cases from 4 sites, and the parents of all participants completed the Chinese version of the ASRS. A robust weighted least squares means and variance adjusted estimator was used for exploratory factor analysis. The 3-factor structure included 59 items suitable for the current sample. The item reliability for the modified Chinese version of the ASRS (MC-ASRS) was excellent. Moreover, with 60 as the cut-off point, receiver operating characteristic analysis showed that the MC-ASRS had excellent discriminate validity, comparable to that of the unmodified Chinese version (UC-ASRS), with area under the curve values of 0.952 (95% CI: 0.936-0.967) and 0.948 (95% CI: 0.930-0.965), respectively. Meanwhile, the confirm factor analysis revealed that MC-ASRS had a better construct validity than UC-ASRS based on the above factor solution in another children sample. In conclusion, the MC-ASRS shows better efficacy in epidemiological screening for ASD in Chinese children.

  9. Development of the Spatial Ability Test for Middle School Students

    Science.gov (United States)

    Yildiz, Sevda Göktepe; Özdemir, Ahmet Sükrü

    2017-01-01

    The purpose of this study was to develop a test to determine spatial ability of middle school students. The participants were 704 middle school students (6th, 7th and 8th grade) who were studying at different schools from Istanbul. Item analysis, exploratory and confirmatory factor analysis, reliability analysis were used to analyse the data.…

  10. Developing educational competencies for dissemination and implementation research training programs: an exploratory analysis using card sorts.

    Science.gov (United States)

    Padek, Margaret; Colditz, Graham; Dobbins, Maureen; Koscielniak, Nikolas; Proctor, Enola K; Sales, Anne E; Brownson, Ross C

    2015-08-12

    With demand increasing for dissemination and implementation (D&I) training programs in the USA and other countries, more structured, competency-based, and tested curricula are needed to guide training programs. There are many benefits to the use of competencies in practice-based education such as the establishment of rigorous standards as well as providing an additional metrics for development and growth. As the first aim of a D&I training grant, an exploratory study was conducted to establish a new set of D&I competencies to guide training in D&I research. Based upon existing D&I training literature, the leadership team compiled an initial list of competencies. The research team then engaged 16 additional colleagues in the area of D&I science to provide suggestions to the initial list. The competency list was then additionally narrowed to 43 unique competencies following feedback elicited from these D&I researchers. Three hundred additional D&I researchers were then invited via email to complete a card sort in which the list of competencies were sorted into three categories of experience levels. Participants had previous first-hand experience with D&I or knowledge translation training programs in the past. Participants reported their self-identified D&I expertise level as well as the country in which their home institution is located. A mean score was calculated for each competency based on their experience level categorization. From these mean scores, beginner-, intermediate-, and advanced-level tertiles were created for the competencies. The card sort request achieved a 41 % response rate (n = 124). The list of 43 competencies was organized into four broad domains and sorted based on their experience level score. Eleven competencies were classified into the "Beginner" category, 27 into "Intermediate," and 5 into "Advanced." Education and training developers can use this competency list to formalize future trainings in D&I research, create more evidence

  11. A Spatial Analysis of Tourism Activity in Romania

    Directory of Open Access Journals (Sweden)

    Daniela Luminita Constantin

    2018-02-01

    Full Text Available Location is a key concept in tourism sector analysis, given the dependence of this activity on the natural, built, cultural and social characteristics of a certain territory. As a result, the tourist zoning is an important instrument for delimiting tourist areas in accordance with multiple criteria, so as to lay the foundations for finding the most suitable solutions of turning to good account the resources in this field. The modern approaches proposed in this paper use a series of analytical tools that combine GIS and spatial agglomeration analysis based techniques. They can be also employed in order to examine and explain the differences between tourist zones (and sub-zones in terms of economic and social results and thus to suggest realistic ways to improve the efficiency and effectiveness of tourist activities in various geographical areas. In the described context this paper proposes an interdisciplinary perspective (spatial statistics and Geographical Information Systems for analysing the tourism activity in Romania, mainly aiming to identify the agglomerations of companies acting in this industry and assess their performance and contribution to the economic development of the corresponding regions. It also intends to contribute to a better understanding of the way in which tourism related business activities develop, in order to enhance appropriate support networks. Territorial and spatial statistics, as well as GIS based analyses are applied, using data about all companies acting in tourism industry in Romania provided by the National Authority for Tourism as well as data from the Environmental Systems Research Institute (ESRI.

  12. On exploratory factor analysis: a review of recent evidence, an assessment of current practice, and recommendations for future use.

    Science.gov (United States)

    Gaskin, Cadeyrn J; Happell, Brenda

    2014-03-01

    Exploratory factor analysis (hereafter, factor analysis) is a complex statistical method that is integral to many fields of research. Using factor analysis requires researchers to make several decisions, each of which affects the solutions generated. In this paper, we focus on five major decisions that are made in conducting factor analysis: (i) establishing how large the sample needs to be, (ii) choosing between factor analysis and principal components analysis, (iii) determining the number of factors to retain, (iv) selecting a method of data extraction, and (v) deciding upon the methods of factor rotation. The purpose of this paper is threefold: (i) to review the literature with respect to these five decisions, (ii) to assess current practices in nursing research, and (iii) to offer recommendations for future use. The literature reviews illustrate that factor analysis remains a dynamic field of study, with recent research having practical implications for those who use this statistical method. The assessment was conducted on 54 factor analysis (and principal components analysis) solutions presented in the results sections of 28 papers published in the 2012 volumes of the 10 highest ranked nursing journals, based on their 5-year impact factors. The main findings from the assessment were that researchers commonly used (a) participants-to-items ratios for determining sample sizes (used for 43% of solutions), (b) principal components analysis (61%) rather than factor analysis (39%), (c) the eigenvalues greater than one rule and screen tests to decide upon the numbers of factors/components to retain (61% and 46%, respectively), (d) principal components analysis and unweighted least squares as methods of data extraction (61% and 19%, respectively), and (e) the Varimax method of rotation (44%). In general, well-established, but out-dated, heuristics and practices informed decision making with respect to the performance of factor analysis in nursing studies. Based on

  13. Spatially explicit analysis of gastropod biodiversity in ancient Lake Ohrid

    Directory of Open Access Journals (Sweden)

    T. Hauffe

    2011-01-01

    Full Text Available The quality of spatial analyses of biodiversity is improved by (i utilizing study areas with well defined physiogeographical boundaries, (ii limiting the impact of widespread species, and (iii using taxa with heterogeneous distributions. These conditions are typically met by ecosystems such as oceanic islands or ancient lakes and their biota. While research on ancient lakes has contributed significantly to our understanding of evolutionary processes, statistically sound studies of spatial variation of extant biodiversity have been hampered by the frequently vast size of ancient lakes, their limited accessibility, and the lack of scientific infrastructure. The European ancient Lake Ohrid provides a rare opportunity for such a reliable spatial study. The comprehensive horizontal and vertical sampling of a species-rich taxon, the Gastropoda, presented here, revealed interesting patterns of biodiversity, which, in part, have not been shown before for other ancient lakes.

    In a total of 284 samples from 224 different locations throughout the Ohrid Basin, 68 gastropod species, with 50 of them (= 73.5% being endemic, could be reported. The spatial distribution of these species shows the following characteristics: (i within Lake Ohrid, the most frequent species are endemic taxa with a wide depth range, (ii widespread species (i.e. those occurring throughout the Balkans or beyond are rare and mainly occur in the upper layer of the lake, (iii while the total number of species decreases with water depth, the proportion of endemics increases, and (iv the deeper layers of Lake Ohrid appear to have a higher spatial homogeneity of biodiversity. Moreover, gastropod communities of Lake Ohrid and its feeder springs are both distinct from each other and from the surrounding waters. The analysis also shows that community similarity of Lake Ohrid is mainly driven by niche processes (e.g. environmental factors, but also by neutral processes (e.g. dispersal

  14. The Association of Academic Health Sciences Libraries Annual Statistics: an exploratory twenty-five-year trend analysis.

    Science.gov (United States)

    Byrd, Gary D; Shedlock, James

    2003-04-01

    This paper presents an exploratory trend analysis of the statistics published over the past twenty-four editions of the Annual Statistics of Medical School Libraries in the United States and Canada. The analysis focuses on the small subset of nineteen consistently collected data variables (out of 656 variables collected during the history of the survey) to provide a general picture of the growth and changing dimensions of services and resources provided by academic health sciences libraries over those two and one-half decades. The paper also analyzes survey response patterns for U.S. and Canadian medical school libraries, as well as osteopathic medical school libraries surveyed since 1987. The trends show steady, but not dramatic, increases in annual means for total volumes collected, expenditures for staff, collections and other operating costs, personnel numbers and salaries, interlibrary lending and borrowing, reference questions, and service hours. However, when controlled for inflation, most categories of expenditure have just managed to stay level. The exceptions have been expenditures for staff development and travel and for collections, which have both outpaced inflation. The fill rate for interlibrary lending requests has remained steady at about 75%, but the mean ratio of items lent to items borrowed has decreased by nearly 50%.

  15. Prenatal stress, fearfulness, and the epigenome: Exploratory analysis of sex differences in DNA methylation of the glucocorticoid receptor gene.

    Directory of Open Access Journals (Sweden)

    Brendan Dale Ostlund

    2016-07-01

    Full Text Available Exposure to stress in utero is a risk factor for the development of problem behavior in the offspring, though precise pathways are unknown. We examined whether DNA methylation of the glucocorticoid receptor gene, NR3C1, was associated with experiences of stress by an expectant mother and fearfulness in her infant. Mothers reported on prenatal stress and infant temperament when infants were 5 months old (n = 68. Buccal cells for methylation analysis were collected from each infant. Prenatal stress was not related to infant fearfulness or NR3C1 methylation in the sample as a whole. Exploratory sex-specific analysis revealed a trend-level association between prenatal stress and increased methylation of NR3C1 exon 1F for female, but not male, infants. In addition, increased methylation was significantly associated with greater fearfulness for females. Results suggest an experience-dependent pathway to fearfulness for female infants via epigenetic modification of the glucocorticoid receptor gene. Future studies should examine prenatal stress in a comprehensive fashion while considering sex differences in epigenetic processes underlying infant temperament.

  16. Determining the number of factors to retain in an exploratory factor analysis using comparison data of known factorial structure.

    Science.gov (United States)

    Ruscio, John; Roche, Brendan

    2012-06-01

    Exploratory factor analysis (EFA) is used routinely in the development and validation of assessment instruments. One of the most significant challenges when one is performing EFA is determining how many factors to retain. Parallel analysis (PA) is an effective stopping rule that compares the eigenvalues of randomly generated data with those for the actual data. PA takes into account sampling error, and at present it is widely considered the best available method. We introduce a variant of PA that goes even further by reproducing the observed correlation matrix rather than generating random data. Comparison data (CD) with known factorial structure are first generated using 1 factor, and then the number of factors is increased until the reproduction of the observed eigenvalues fails to improve significantly. We evaluated the performance of PA, CD with known factorial structure, and 7 other techniques in a simulation study spanning a wide range of challenging data conditions. In terms of accuracy and robustness across data conditions, the CD technique outperformed all other methods, including a nontrivial superiority to PA. We provide program code to implement the CD technique, which requires no more specialized knowledge or skills than performing PA. (c) 2012 APA, all rights reserved

  17. Internal versus external preference analysis : an exploratory study on end-user evaluation

    NARCIS (Netherlands)

    Kleef, van E.; Trijp, van H.C.M.; Luning, P.A.

    2006-01-01

    Internal and external preference analysis emphasise fundamentally different perspectives on the same data. We extend the literature on comparisons between internal and external preference analysis by incorporating the perspective of the end user of the preference analysis results. From a conceptual

  18. An Introduction to Macro- Level Spatial Nonstationarity: a Geographically Weighted Regression Analysis of Diabetes and Poverty.

    Science.gov (United States)

    Siordia, Carlos; Saenz, Joseph; Tom, Sarah E

    2012-01-01

    Type II diabetes is a growing health problem in the United States. Understanding geographic variation in diabetes prevalence will inform where resources for management and prevention should be allocated. Investigations of the correlates of diabetes prevalence have largely ignored how spatial nonstationarity might play a role in the macro-level distribution of diabetes. This paper introduces the reader to the concept of spatial nonstationarity-variance in statistical relationships as a function of geographical location. Since spatial nonstationarity means different predictors can have varying effects on model outcomes, we make use of a geographically weighed regression to calculate correlates of diabetes as a function of geographic location. By doing so, we demonstrate an exploratory example in which the diabetes-poverty macro-level statistical relationship varies as a function of location. In particular, we provide evidence that when predicting macro-level diabetes prevalence, poverty is not always positively associated with diabetes.

  19. Alternate assessment use with students who are deaf or hard of hearing: an exploratory mixed-methods analysis of portfolio, checklists, and out-of-level test formats.

    Science.gov (United States)

    Cawthon, Stephanie W; Wurtz, Keith A

    2009-01-01

    The purpose of this paper is to present findings on alternate assessments for students who are deaf or hard of hearing (SDHH). Drawn from the results of the "Second National Survey of Assessments and Accommodations for Students Who Are Deaf or Hard of Hearing," this study investigated three alternate assessment formats: portfolio, checklists, and out-of-level testing. Analysis includes descriptive data of alternate assessment use across all three formats, qualitative analyses of teacher perspectives, and an exploratory logistic regression analysis on predictors of alternate assessment use. This exploratory analysis looks at predictors such as state policy, educational setting, grades served, language of instruction, and participant perspectives. Results indicate that predictors at the student, teacher, and system level may influence alternate assessment use for SDHH.

  20. Scratching the surface: Exploratory analysis of key opinion leaders on rate limiting factors in novel adjuvanted-vaccine

    NARCIS (Netherlands)

    Pronker, E.S.; Claassen, E.; Weenen, T; Commandeur, H; Osterhaus, A.D.M.E.

    2015-01-01

    This exploratory qualitative article analyzes the potentially rate-limiting factors affecting value chain dynamics during adjuvanted-vaccine development. Adjuvants are considered immunostimulating substances that can be added to a vaccine. Although adjuvants have the potential to elicit adverse

  1. The relationship between language and spatial ability an analysis of spatial language for reconstructing the solving of spatial tasks

    CERN Document Server

    Mizzi, Angel

    2017-01-01

    This work investigates how different fifth-grade students solve spatial-verbal tasks and the role of language in this process. Based on a synthesis of theoretical foundations and methodological issues for supporting the relationship between spatial ability and language, this present study examines and classifies strategies used by students as well as the obstacles they encounter when solving spatial tasks in the reconstruction method. Contents Theoretical Framework Design and Implementation Results and Discussion from the Inductive Data Analyses Target Groups Scholars and students of mathematics education Teachers of mathematics in primary and secondary schools About the Author Angel Mizzi works as a research assistant and lecturer at the University of Duisburg-Essen, where he has successfully completed his PhD studies in mathematics education.

  2. The R-package GenomicTools for multifactor dimensionality reduction and the analysis of (exploratory) Quantitative Trait Loci.

    Science.gov (United States)

    Fischer, Daniel

    2017-11-01

    We introduce the R-package GenomicTools to perform, among others, a Multifactor Dimensionality Reduction (MDR) for the identification of SNP-SNP interactions. The package further provides a new class of tests for an (exploratory) Quantitative Trait Loci analysis that overcomes some of the limitations of other popular (e)QTL approaches. Popular (e)QTL approaches that use linear models or ANOVA are often based on over-simplified models that have weak statistical properties and which are not robust against outlying observations. The algorithm to calculate the MDR is well established. To speed up its calculation in R, we implemented it in C++. Further, our implementation also supports the combination of several MDR results to an MDR ensemble classifier. The (e)QTL test procedure is based on a generalized Mann-Whitney test that is tailored for directional alternatives, as they are present in an (e)QTL analysis. Our package GenomicTools provides functions to determine SNP combinations that have the highest accuracy for a MDR classification problem. It also provides functions to combine the best MDR results to a joined ensemble classifier for improved classification results. Further, the (e)QTL analysis is based on a solid statistical theory. In addition, informative visualizations of the results are provided. The here presented new class of tests and methods have an easy to apply syntax, so that also researchers inexperienced in R are able to apply our proposed methods and implementations. The package creates publication ready Figures and hence could be a valuable tool for genomic data analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Web 2.0 in the Professional LIS Literature: An Exploratory Analysis

    Science.gov (United States)

    Aharony, Noa

    2011-01-01

    This paper presents a statistical descriptive analysis and a thorough content analysis of descriptors and journal titles extracted from the Library and Information Science Abstracts (LISA) database, focusing on the subject of Web 2.0 and its main applications: blog, wiki, social network and tags.The primary research questions include: whether the…

  4. Parallel Factor Analysis as an exploratory tool for wavelet transformed event-related EEG

    DEFF Research Database (Denmark)

    Mørup, Morten; Hansen, Lars Kai; Hermann, Cristoph S.

    2006-01-01

    In the decomposition of multi-channel EEG signals, principal component analysis (PCA) and independent component analysis (ICA) have widely been used. However, as both methods are based on handling two-way data, i.e. two-dimensional matrices, multi-way methods might improve the interpretation of f...

  5. Multivariate analysis of spatial-temporal scales in melanoma prevalence.

    Science.gov (United States)

    Valachovic, Edward; Zurbenko, Igor

    2017-07-01

    Melanoma is a particularly deadly form of skin cancer arising from diverse biological and physical origins, making the characterization and quantification of relationships with recognized risk factors very complex. Melanoma has known associations with ultraviolet light exposure. Natural variations in solar electromagnetic irradiation, length of exposure, and intensity operate on different and therefore uncorrelated time scale frequencies. It is necessary to separate and investigate the principal components, such as the annual and solar cycle components, free from confounding influences. Kolmogorov-Zurbenko spatial filters applied to melanoma prevalence and environmental factors affecting solar irradiation exposure are able to identify and separate the independent space and time scale components of melanoma. Multidimensional analysis in space and time produces significantly improved model fit of what is in effect a linear regression of maps, or motion picture, in different time scales between melanoma rates and prominent factors. The resulting multivariate model coefficients of influence for each unique spatial-temporal melanoma component help quantify the relationships and are valuable to future research and prevention.

  6. Defensible Spaces in Philadelphia: Exploring Neighborhood Boundaries Through Spatial Analysis

    Directory of Open Access Journals (Sweden)

    Rory Kramer

    2017-02-01

    Full Text Available Few spatial scales are as important to individual outcomes as the neighborhood. However, it is nearly impossible to define neighborhoods in a generalizable way. This article proposes that by shifting the focus to measuring neighborhood boundaries rather than neighborhoods, scholars can avoid the problem of the indefinable neighborhood and better approach questions of what predicts racial segregation across areas. By quantifying an externality space theory of neighborhood boundaries, this article introduces a novel form of spatial analysis to test where potential physical markers of neighborhood boundaries (major roads, rivers, railroads, and the like are associated with persistent racial boundaries between 1990 and 2010. Using Philadelphia as a case study, the paper identifies neighborhoods with persistent racial boundaries. It theorizes that local histories of white reactions to black in-migration explain which boundaries persistently resisted racial turnover, unlike the majority of Philadelphia’s neighborhoods, and that those racial boundaries shape the location, progress, and reaction to new residential development in those neighborhoods.

  7. Spatial Analysis of Stomach Cancer Incidence in Iran.

    Science.gov (United States)

    Pakzad, Reza; Khani, Yousef; Pakzad, Iraj; Momenimovahed, Zohre; Mohammadian-Hashejani, Abdollah; Salehiniya, Hamid; Towhidi, Farhad; Makhsosi, Behnam Reza

    2016-01-01

    Stomach cancer, the fourth most common cancer and the second leading cause of cancer-related death through the world, is very common in parts of Iran. Geographic variation in the incidence of stomach cancer is due to many different factors. The aim of this study was to assess the geographical and spatial distribution of stomach cancer in Iran using data from the cancer registry program in Iran for the year 2009. The reported incidences of stomach cancer for different provinces were standardized to the world population structure. ArcGIS software was used to analyse the data. Hot spots and high risk areas were determined using spatial analysis (Getis-Ord Gi). Hot and cold spots were determined as more than or less than 2 standard deviations from the national average, respectively. A significance level of 0.10 was used for statistical judgment. In 2009, a total of 6,886 cases of stomach cancers were reported of which 4,891 were in men and 1,995 in women (standardized incidence rates of 19.2 and 10.0, respectively, per 100,000 population). The results showed that stomach cancer was concentrated mainly in northwest of the country in both men and women. In women, northwest provinces such as Ardebil, East Azerbaijan, West Azerbaijan, Gilan, and Qazvin were identified as hot spots (pstomach cancer is clustered in the northwest of the country, further epidemiological studies are needed to identify factors contributing to this concentration.

  8. Single Particle Differentiation through 2D Optical Fiber Trapping and Back-Scattered Signal Statistical Analysis: An Exploratory Approach.

    Science.gov (United States)

    Paiva, Joana S; Ribeiro, Rita S R; Cunha, João P S; Rosa, Carla C; Jorge, Pedro A S

    2018-02-27

    Recent trends on microbiology point out the urge to develop optical micro-tools with multifunctionalities such as simultaneous manipulation and sensing. Considering that miniaturization has been recognized as one of the most important paradigms of emerging sensing biotechnologies, optical fiber tools, including Optical Fiber Tweezers (OFTs), are suitable candidates for developing multifunctional small sensors for Medicine and Biology. OFTs are flexible and versatile optotools based on fibers with one extremity patterned to form a micro-lens. These are able to focus laser beams and exert forces onto microparticles strong enough (piconewtons) to trap and manipulate them. In this paper, through an exploratory analysis of a 45 features set, including time and frequency-domain parameters of the back-scattered signal of particles trapped by a polymeric lens, we created a novel single feature able to differentiate synthetic particles (PMMA and Polystyrene) from living yeasts cells. This single statistical feature can be useful for the development of label-free hybrid optical fiber sensors with applications in infectious diseases detection or cells sorting. It can also contribute, by revealing the most significant information that can be extracted from the scattered signal, to the development of a simpler method for particles characterization (in terms of composition, heterogeneity degree) than existent technologies.

  9. Relative controls of natural and socio-economic drivers on water availability over India: an exploratory modelling analysis

    Science.gov (United States)

    Deshmukh, A.; Singh, R.; Kumar, R.

    2017-12-01

    India, a water stressed nation with an estimated per capita water availability of 1500m3/year/person, is projected to surpass China in population to become the most populous country by 2022. This increasing population will further exacerbate the water stress, which will also vary due to climate and land use change. Here, we quantify the relative controls on per capita water availability from climatic, non-climatic and socio-economic factors. We achieve this by using several definitions of per capita water availability and accounting for virtual water trade transfer. Our exploratory analysis employs the recently developed probabilistic Budyko framework modified to account for inter-regional virtual water trade. We find that the Indo-Gangetic plains and Southeastern parts of India emerge as vulnerable regions where a growing population will lead to a drastic reduction in per capita water availability. The proposed framework can serve as a prototype for understanding the relative importance of socio-economic interventions versus water infrastructure or demand reduction investments.

  10. What does cancer treatment look like in consumer cancer magazines? An exploratory analysis of photographic content in consumer cancer magazines.

    Science.gov (United States)

    Phillips, Selene G; Della, Lindsay J; Sohn, Steve H

    2011-04-01

    In an exploratory analysis of several highly circulated consumer cancer magazines, the authors evaluated congruency between visual images of cancer patients and target audience risk profile. The authors assessed 413 images of cancer patients/potential patients for demographic variables such as age, gender, and ethnicity/race. They compared this profile with actual risk statistics. The images in the magazines are considerably younger, more female, and more White than what is indicated by U.S. cancer risk statistics. The authors also assessed images for visual signs of cancer testing/diagnosis and treatment. Few individuals show obvious signs of cancer treatment (e.g., head scarves, skin/nail abnormalities, thin body types). Most images feature healthier looking people, some actively engaged in construction work, bicycling, and yoga. In contrast, a scan of the editorial content showed that nearly two thirds of the articles focus on treatment issues. To explicate the implications of this imagery-text discontinuity on readers' attention and cognitive processing, the authors used constructs from information processing and social identity theories. On the basis of these models/theories, the authors provide recommendations for consumer cancer magazines, suggesting that the imagery be adjusted to reflect cancer diagnosis realities for enhanced message attention and comprehension.

  11. Dynamic Optimization of Ecosystem Services: A Comparative Analysis of Non-Spatial and Spatially-Explicit Models

    OpenAIRE

    Yun, Seong Do; Gramig, Benjamin M.

    2014-01-01

    This study develops and solves a stochastic, multi-year, discrete space-time model that allows the comparative analysis between non-spatial and spatially explicit models. The solution to this model implies the Stochastic Space-Time Natural Enemy-adjusted Economic Threshold (SST-NEET) to guide the choice of the optimal level of a pest that warrants management intervention. Using numerical simulation experiments over a generated synthetic geography, we derive three major conclusions. First, a u...

  12. Exploratory analysis of social cognition and neurocognition in individuals at clinical high risk for psychosis.

    Science.gov (United States)

    Yong, Emma; Barbato, Mariapaola; Penn, David L; Keefe, Richard S E; Woods, Scott W; Perkins, Diana O; Addington, Jean

    2014-08-15

    Neurocognition and social cognition are separate but related constructs known to be impaired in schizophrenia. The aim of this study was to extend the current knowledge of the relationship between social cognition and neurocognition in individuals at clinical high risk (CHR) of developing psychosis by examining, in a large sample, the associations between a wide range of neurocognitive tasks and social cognition. Participants included 136 young people at CHR. Specific domains within neurocognition and social cognition were compared using Spearman correlations. Results showed that poor theory of mind correlated with low ratings on a wide range of neurocognitive tasks. Facial affect was more often associated with low ratings on spatial working memory and attention. These results support a link between neurocognition and social cognition even at this early stage of potential psychosis, with indication that poorer performance on social cognition may be associated with deficits in attention and working memory. Understanding these early associations may have implications for early intervention. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. Community crosstalk: An exploratory analysis of destination and festival eWOM on Twitter

    OpenAIRE

    Williams, Nigel; Inversini, Alessandro; Buhalis, Dimitrios; Ferdinand, Nicole

    2015-01-01

    Research suggests that festivals can promote a destination via online word-of-mouth (eWOM) on socialmedia, even though the nature of this effect is not yet fully understood. Using a combination of Social Network Analysis and text analysis (qualitative and quantitative), this article examines eWOM at a tourism destination (Bournemouth) when a festival (Bournemouth Air Show 2013) is staged. The Communities of Interest of eWOM interactions on Twitter were captured and analysed to understand the ...

  14. Psychometric analysis of five measures of spatial ability.

    Science.gov (United States)

    Hogan, Thomas P

    2012-02-01

    This study analyzed psychometric properties of five measures of spatial ability on 96 young adults, with supplementary analysis for three of the measures on another sample of 71 young adults. Two measures were taken from the widely cited Kit of Factor-Referenced Cognitive Tests and three other measures were taken from a relatively new source originally intended as laboratory demonstrations. Previous research provided limited information on the psychometric properties of the measures. All five measures yielded adequate reliability and loaded on a single factor. Three measures yielded markedly skewed distributions. Two measures showed clear sex differences with men scoring higher but this difference seemed contaminated by a speed factor; three measures did not show a sex difference. Recommendations for use of the measures in future studies are provided.

  15. Spatial analysis of Crimean Congo hemorrhagic fever in Iran.

    Science.gov (United States)

    Mostafavi, Ehsan; Haghdoost, AliAkbar; Khakifirouz, Sahar; Chinikar, Sadegh

    2013-12-01

    Crimean Congo hemorrhagic fever (CCHF) is a viral zoonotic disease. During 1999-2011, 871 human cases of CCHF were diagnosed in Iran. A history of serologic conversion for CCHF virus was seen in 58.7% of 2,447 sheep samples, 25.0% of 1,091 cattle samples and 24.8% of 987 goat samples from different parts of Iran. Spatial analysis showed that the main foci of this disease in humans during these years were in eastern Iran (P < 0.01) and the second most common foci were in northeastern and central Iran. Two livestock foci were detected in the northeastern northwestern Iran. On the basis of the results of this study, infection likely entered Iran from eastern and western neighboring countries.

  16. A novel exploratory chemometric approach to environmental monitorring by combining block clustering with Partial Least Square (PLS) analysis.

    Science.gov (United States)

    Nica, Dragos V; Bordean, Despina Maria; Pet, Ioan; Pet, Elena; Alda, Simion; Gergen, Iosif

    2013-08-30

    Given the serious threats posed to terrestrial ecosystems by industrial contamination, environmental monitoring is a standard procedure used for assessing the current status of an environment or trends in environmental parameters. Measurement of metal concentrations at different trophic levels followed by their statistical analysis using exploratory multivariate methods can provide meaningful information on the status of environmental quality. In this context, the present paper proposes a novel chemometric approach to standard statistical methods by combining the Block clustering with Partial least square (PLS) analysis to investigate the accumulation patterns of metals in anthropized terrestrial ecosystems. The present study focused on copper, zinc, manganese, iron, cobalt, cadmium, nickel, and lead transfer along a soil-plant-snai food chain, and the hepatopancreas of the Roman snail (Helix pomatia) was used as a biological end-point of metal accumulation. Block clustering deliniates between the areas exposed to industrial and vehicular contamination. The toxic metals have similar distributions in the nettle leaves and snail hepatopancreas. PLS analysis showed that (1) zinc and copper concentrations at the lower trophic levels are the most important latent factors that contribute to metal accumulation in land snails; (2) cadmium and lead are the main determinants of pollution pattern in areas exposed to industrial contamination; (3) at the sites located near roads lead is the most threatfull metal for terrestrial ecosystems. There were three major benefits by applying block clustering with PLS for processing the obtained data: firstly, it helped in grouping sites depending on the type of contamination. Secondly, it was valuable for identifying the latent factors that contribute the most to metal accumulation in land snails. Finally, it optimized the number and type of data that are best for monitoring the status of metallic contamination in terrestrial ecosystems

  17. Integrating the statistical analysis of spatial data in ecology

    Science.gov (United States)

    A. M. Liebhold; J. Gurevitch

    2002-01-01

    In many areas of ecology there is an increasing emphasis on spatial relationships. Often ecologists are interested in new ways of analyzing data with the objective of quantifying spatial patterns, and in designing surveys and experiments in light of the recognition that there may be underlying spatial pattern in biotic responses. In doing so, ecologists have adopted a...

  18. Exploratory analysis of excitation-emission matrix fluorescence spectra with self-organizing maps as a basis for determination of organic matter removal efficiency at water treatment works

    OpenAIRE

    Bieroza, Magdalena; Baker, Andy; Bridgeman, John

    2009-01-01

    In the paper, the self-organizing map (SOM) was employed for the exploratory analysis of fluorescence excitation-emission data characterising organic matter removal efficiency at 16 water treatment works in the UK. Fluorescence spectroscopy was used to assess organic matter removal efficiency between raw and partially-treated (clarified) water to provide an indication of the potential for disinfection by-products (DBPs) formation. Fluorescence spectroscopy was utilized to evaluate quantitativ...

  19. Cluster analysis in severe emphysema subjects using phenotype and genotype data: an exploratory investigation

    Directory of Open Access Journals (Sweden)

    Martinez Fernando J

    2010-03-01

    Full Text Available Abstract Background Numerous studies have demonstrated associations between genetic markers and COPD, but results have been inconsistent. One reason may be heterogeneity in disease definition. Unsupervised learning approaches may assist in understanding disease heterogeneity. Methods We selected 31 phenotypic variables and 12 SNPs from five candidate genes in 308 subjects in the National Emphysema Treatment Trial (NETT Genetics Ancillary Study cohort. We used factor analysis to select a subset of phenotypic variables, and then used cluster analysis to identify subtypes of severe emphysema. We examined the phenotypic and genotypic characteristics of each cluster. Results We identified six factors accounting for 75% of the shared variability among our initial phenotypic variables. We selected four phenotypic variables from these factors for cluster analysis: 1 post-bronchodilator FEV1 percent predicted, 2 percent bronchodilator responsiveness, and quantitative CT measurements of 3 apical emphysema and 4 airway wall thickness. K-means cluster analysis revealed four clusters, though separation between clusters was modest: 1 emphysema predominant, 2 bronchodilator responsive, with higher FEV1; 3 discordant, with a lower FEV1 despite less severe emphysema and lower airway wall thickness, and 4 airway predominant. Of the genotypes examined, membership in cluster 1 (emphysema-predominant was associated with TGFB1 SNP rs1800470. Conclusions Cluster analysis may identify meaningful disease subtypes and/or groups of related phenotypic variables even in a highly selected group of severe emphysema subjects, and may be useful for genetic association studies.

  20. Species distribution of kobs (Kobus kob) in the Shai Hills Resource Reserve: an exploratory analysis.

    Science.gov (United States)

    Antwi, Raymond Agyepong; Owusu, Erasmus Henaku; Attuquayefio, Daniel Korley

    2018-02-01

    The well-being of a species fundamentally rests on understanding its biology, home range, and distribution. The highly seasonal distribution of kobs poses conservation and management difficulties, particularly because of the capricious nature of the ever-changing ecological and vegetation dynamics of the ecosystem. Assessing the distribution of kobs and their associated vegetation provides insight into the vulnerability and conservation status of the species. Species distribution and habitat suitability maps were developed and created respectively for the management of kobs in the Shai Hills Resource Reserve. Kob presence data collected was analyzed using the spatial analyst and Hawth's tool in the ArcGIS software where the gradients of kob distribution within the protected area landscape were plotted and mapped. Seven environmental variables including location, land cover/use, slope/elevation, nearness to dams and rivers, temperature, and rainfall were considered to have effect on kob distribution pattern and as such used in the development of species distribution and habitat suitability maps. The results indicated that kobs in the Shai Hills Resource Reserve (SHRR) assume a clumped or contagious distribution pattern where individual kobs are aggregated in patches. Rainfall, temperature, nearness to dams and rivers, slope/elevation, and land cover/use had influence in kob distribution. Of all the cataloged habitats, 86, 13, and 1% were moderately suitable, suitable, and unsuitable, respectively. Long-term survival of species depends on adequately large areas of suitable habitats and opportunities for home range activities between such areas. As such, it is recommended that suitable habitats for kobs be dedicated and designated as conservation areas, especially areas along the western boundary.

  1. Visualization and exploratory analysis of epidemiologic data using a novel space time information system

    Directory of Open Access Journals (Sweden)

    Kaufmann Andrew M

    2004-11-01

    Full Text Available Abstract Background Recent years have seen an expansion in the use of Geographic Information Systems (GIS in environmental health research. In this field GIS can be used to detect disease clustering, to analyze access to hospital emergency care, to predict environmental outbreaks, and to estimate exposure to toxic compounds. Despite these advances the inability of GIS to properly handle temporal information is increasingly recognised as a significant constraint. The effective representation and visualization of both spatial and temporal dimensions therefore is expected to significantly enhance our ability to undertake environmental health research using time-referenced geospatial data. Especially for diseases with long latency periods (such as cancer the ability to represent, quantify and model individual exposure through time is a critical component of risk estimation. In response to this need a STIS – a Space Time Information System has been developed to visualize and analyze objects simultaneously through space and time. Results In this paper we present a "first use" of a STIS in a case-control study of the relationship between arsenic exposure and bladder cancer in south eastern Michigan. Individual arsenic exposure is reconstructed by incorporating spatiotemporal data including residential mobility and drinking water habits. The unique contribution of the STIS is its ability to visualize and analyze residential histories over different temporal scales. Participant information is viewed and statistically analyzed using dynamic views in which values of an attribute change through time. These views include tables, graphs (such as histograms and scatterplots, and maps. In addition, these views can be linked and synchronized for complex data exploration using cartographic brushing, statistical brushing, and animation. Conclusion The STIS provides new and powerful ways to visualize and analyze how individual exposure and associated

  2. Visualization and exploratory analysis of epidemiologic data using a novel space time information system

    Science.gov (United States)

    AvRuskin, Gillian A; Jacquez, Geoffrey M; Meliker, Jaymie R; Slotnick, Melissa J; Kaufmann, Andrew M; Nriagu, Jerome O

    2004-01-01

    Background Recent years have seen an expansion in the use of Geographic Information Systems (GIS) in environmental health research. In this field GIS can be used to detect disease clustering, to analyze access to hospital emergency care, to predict environmental outbreaks, and to estimate exposure to toxic compounds. Despite these advances the inability of GIS to properly handle temporal information is increasingly recognised as a significant constraint. The effective representation and visualization of both spatial and temporal dimensions therefore is expected to significantly enhance our ability to undertake environmental health research using time-referenced geospatial data. Especially for diseases with long latency periods (such as cancer) the ability to represent, quantify and model individual exposure through time is a critical component of risk estimation. In response to this need a STIS – a Space Time Information System has been developed to visualize and analyze objects simultaneously through space and time. Results In this paper we present a "first use" of a STIS in a case-control study of the relationship between arsenic exposure and bladder cancer in south eastern Michigan. Individual arsenic exposure is reconstructed by incorporating spatiotemporal data including residential mobility and drinking water habits. The unique contribution of the STIS is its ability to visualize and analyze residential histories over different temporal scales. Participant information is viewed and statistically analyzed using dynamic views in which values of an attribute change through time. These views include tables, graphs (such as histograms and scatterplots), and maps. In addition, these views can be linked and synchronized for complex data exploration using cartographic brushing, statistical brushing, and animation. Conclusion The STIS provides new and powerful ways to visualize and analyze how individual exposure and associated environmental variables change through

  3. Multitemporal spatial pattern analysis of Tulum's tropical coastal landscape

    Science.gov (United States)

    Ramírez-Forero, Sandra Carolina; López-Caloca, Alejandra; Silván-Cárdenas, José Luis

    2011-11-01

    The tropical coastal landscape of Tulum in Quintana Roo, Mexico has a high ecological, economical, social and cultural value, it provides environmental and tourism services at global, national, regional and local levels. The landscape of the area is heterogeneous and presents random fragmentation patterns. In recent years, tourist services of the region has been increased promoting an accelerate expansion of hotels, transportation and recreation infrastructure altering the complex landscape. It is important to understand the environmental dynamics through temporal changes on the spatial patterns and to propose a better management of this ecological area to the authorities. This paper addresses a multi-temporal analysis of land cover changes from 1993 to 2000 in Tulum using Thematic Mapper data acquired by Landsat-5. Two independent methodologies were applied for the analysis of changes in the landscape and for the definition of fragmentation patterns. First, an Iteratively Multivariate Alteration Detection (IR-MAD) algorithm was used to detect and localize land cover change/no-change areas. Second, the post-classification change detection evaluated using the Support Vector Machine (SVM) algorithm. Landscape metrics were calculated from the results of IR-MAD and SVM. The analysis of the metrics indicated, among other things, a higher fragmentation pattern along roadways.

  4. Emotional/psychological and related problems among truant youths: An exploratory latent class analysis.

    Science.gov (United States)

    Dembo, Richard; Briones-Robinson, Rhissa; Ungaro, Rocio; Gulledge, Laura; Karas, Lora; Winters, Ken C; Belenko, Steven; Greenbaum, Paul E

    2012-09-01

    Latent class analysis was conducted on the psychosocial problems experienced by truant youths. Data were obtained from baseline interviews completed on 131 youths and their parents/guardians involved in a NIDA-funded, Brief Intervention Project. Results identified two classes of youths: Class 1(n=94): youths with low levels of delinquency, mental health and substance abuse issues, Class 2(n=37): youths with high levels of these problems. Comparison of these two classes on their urine analysis test results and parent/guardian reports of traumatic events found significant (p<.05) differences between them that were consistent with their problem group classification. Our results have important implications for research and practice.

  5. Exploratory analysis for the identification of false banknotes using portable X-ray Fluorescence spectrometer.

    Science.gov (United States)

    Zamalloa Jara, M A; Luízar Obregón, C; Araujo Del Castillo, C

    2018-05-01

    The aim of this study was to verify if a portable X-ray fluorescence (pXRF) spectrometer can recognize the security features in banknotes that are reproducible by counterfeiters. Peruvian Nuevo Sol banknotes were studied: 4 genuine and 3 fake ones, in 11 points of analysis for each one, at all 77 data set. The correlation analysis of spectra among original notes was 1.0, and there was no correlation with fake banknotes. pXRF prove that two security features were reproducible for counterfeiters. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Exploratory space-time analysis of reported dengue cases during an outbreak in Florida, Puerto Rico, 1991-1992.

    Science.gov (United States)

    Morrison, A C; Getis, A; Santiago, M; Rigau-Perez, J G; Reiter, P

    1998-03-01

    The spatial and temporal distributions of dengue cases reported during a 1991-1992 outbreak in Florida, Puerto Rico (population = 8,689), were studied by using a Geographic Information System. A total of 377 dengue cases were identified from a laboratory-based dengue surveillance system and georeferenced by their residential addresses on digital zoning and U.S. Geological Survey topographic maps. Weekly case maps were generated for the period between June and December 1991, when 94.2% of the dengue cases were reported. The temporal evolution of the epidemic was rapid, affecting a wide geographic area within seven weeks of the first reported cases of the season. Dengue cases were reported in 217 houses; of these 56 (25.8%) had between two and six reported cases. K-function analysis was used to characterize the spatial clustering patterns for all reported dengue cases (laboratory-positive and indeterminate) and laboratory-positive cases alone, while the Barton and David and Knox tests were used to characterize spatio-temporal attributes of dengue cases reported during the 1991-1992 outbreak. For both sets of data significant case clustering was identified within individual households over short periods of time (three days or less), but in general, the cases had spatial pattern characteristics much like the population pattern as a whole. The rapid temporal and spatial progress of the disease within the community suggests that control measures should be applied to the entire municipality, rather than to the areas immediately surrounding houses of reported cases. The potential for incorporating Geographic Information System technologies into a dengue surveillance system and the limitations of using surveillance data for spatial studies are discussed.

  7. Spatial variability of residual nitrate-nitrogen under two tillage systems in central Iowa: A composite three-dimensional resistant and exploratory approach

    Science.gov (United States)

    Mohanty, B. P.; Kanwar, R. S.

    1994-02-01

    Soil nitrate-nitrogen (NO3-N) data arranged on a three-dimensional grid were analyzed to compare tillage effect on the spatial distribution of residual NO3-N in the soil profile of agricultural plots drained by subsurface tiles. A three-dimensional median-based resistant (to outlier(s)) approach was developed to polish the spatially located data on soil NO3-N affected by directional trends (nonstationarity in the mean) in three major directions (row, column, and depth) and along the horizontal diagonal directions of the grid. Effect of preferential or nonpreferential path of transport of NO3-N in the vertical direction defined as sample hole effect was also removed to make the data trend-free across holes. Composite three-dimensional semivariogram models (along horizontal and vertical directions) were used to describe the spatial structure of residual soil nitrate distribution. Two plots in the same field, one under each tillage system (conventional tillage and no tillage), were studied. In each plot, soil samples were collected at five depths (30, 60, 90, 120, and 150 cm) from 35 sites (holes) arranged on a 7×5 regular grid of 7.6×7.6 m. In the conventional tillage plot, residual NO3-N concentrations decreased gradually to a depth of 90 cm and increased beyond this depth. The coefficient of variation, however, became gradually smaller, showing more uniform distribution for greater depths. In the no-tillage plot, trends were similar to those in the conventional tillage system, but were spatially more stable across the profile. Structural analyses indicated that under conventional tillage, the semivariogram of residual soil nitrate distribution was linear in the horizontal and vertical directions. In contrast, the semivariograms for no-tillage showed nugget-type behavior, indicating a lack of spatial structure in the residual soil nitrate.

  8. Assessing Model Fit: Caveats and Recommendations for Confirmatory Factor Analysis and Exploratory Structural Equation Modeling

    Science.gov (United States)

    Perry, John L.; Nicholls, Adam R.; Clough, Peter J.; Crust, Lee

    2015-01-01

    Despite the limitations of overgeneralizing cutoff values for confirmatory factor analysis (CFA; e.g., Marsh, Hau, & Wen, 2004), they are still often employed as golden rules for assessing factorial validity in sport and exercise psychology. The purpose of this study was to investigate the appropriateness of using the CFA approach with these…

  9. Effect of Internet-Based Learning in Public Health Training: An Exploratory Meta-Analysis

    Science.gov (United States)

    Peng, Ying; Yan, Weirong

    2017-01-01

    Internet-based learning is increasingly applied in medical education, but its effect in the field of public health training is still unclear. This meta-analysis was undertaken to explore the impact of Internet-based learning on students'/professionals' knowledge of public health compared with no intervention and with traditional face-to-face (FTF)…

  10. Understanding Older Adults' Perceptions of Internet Use: An Exploratory Factor Analysis

    Science.gov (United States)

    Zheng, Robert; Spears, Jeffrey; Luptak, Marilyn; Wilby, Frances

    2015-01-01

    The current study examined factors related to older adults' perceptions of Internet use. Three hundred ninety five older adults participated in the study. The factor analysis revealed four factors perceived by older adults as critical to their Internet use: social connection, self-efficacy, the need to seek financial information, and the need to…

  11. Emotional Psychological and Related Problems among Truant Youths: An Exploratory Latent Class Analysis

    Science.gov (United States)

    Dembo, Richard; Briones-Robinson, Rhissa; Ungaro, Rocio Aracelis; Gulledge, Laura M.; Karas, Lora M.; Winters, Ken C.; Belenko, Steven; Greenbaum, Paul E.

    2012-01-01

    Intervention Project. Results identified two classes of youths: Class 1(n=9) - youths with low levels of delinquency, mental health and substance abuse issues; and Class 2(n=37) - youths with high levels of these problems. Comparison of these two classes on their urine analysis test results and parent/guardian reports of traumatic events found…

  12. Toward exploratory analysis of diversity unified across fields of study: an information visualization approach

    Science.gov (United States)

    Tuan Pham; Julia Jones; Ronald Metoyer; Frederick Colwell

    2014-01-01

    The study of the diversity of multivariate objects shares common characteristics and goals across disciplines, including ecology and organizational management. Nevertheless, subject-matter experts have adopted somewhat separate diversity concepts and analysis techniques, limiting the potential for sharing and comparing across disciplines. Moreover, while large and...

  13. Exploratory Factor Analysis as a Construct Validation Tool: (Mis)applications in Applied Linguistics Research

    Science.gov (United States)

    Karami, Hossein

    2015-01-01

    Factor analysis has been frequently exploited in applied research to provide evidence about the underlying factors in various measurement instruments. A close inspection of a large number of studies published in leading applied linguistic journals shows that there is a misconception among applied linguists as to the relative merits of exploratory…

  14. Representations of Childcare in the Australian Print Media: An Exploratory Corpus-Assisted Discourse Analysis

    Science.gov (United States)

    Fenech, Marianne; Wilkins, David P.

    2017-01-01

    While an increasing body of Australian and international research has explored the relationship between media and education, few studies have examined this relationship in the context of early childhood education. This paper contributes to this research gap by reporting on a corpus-assisted discourse analysis of how childcare is represented in 801…

  15. Off-Pump Coronary Artery Bypass Grafting and Stroke-Exploratory Analysis of the GOPCABE Trial and Methodological Considerations.

    Science.gov (United States)

    Reents, Wilko; Zacher, Michael; Boergermann, Jochen; Kappert, Utz; Hilker, Michael; Färber, Gloria; Albert, Marc; Holzhey, David; Conradi, Lenard; Riess, Friedrich Christian; Veeckman, Philippe; Strauch, Justus T; Diegeler, Anno; Böning, Andreas

    2018-03-22

     Coronary artery bypass grafting (CABG) without cardiopulmonary bypass (off-pump CABG) may reduce severe adverse events including stroke.  In the German Off-Pump Coronary Artery Bypass Grafting in Elderly patients trial, the rate of major adverse cardiovascular events was compared in 2,394 elderly (≥ 75 years) patients undergoing CABG with (on-pump) or without (off-pump) cardiopulmonary bypass. This exploratory post-hoc analysis investigated the impact of surgical aortic manipulation on the rate of stroke.  There was no significant difference in the rate of stroke within 30 days after surgery between both groups (off-pump: 2.2%; on-pump: 2.7%; odds ratio [OR]: 0.83 [0.5-1.38]; p  = 0.47). Within the off-pump group, different degrees of aortic manipulation did not lead to significant different stroke rates (tangential clamping: 2.3%; OR 0.86 [0.46-1.60]; clampless device: 1.8%; OR 0.67 [0.26-1.75]; no aortic manipulation: 2.4%; OR 0.88 [0.37-2.14]). An aggregate analysis including more than 10,000 patients out of the four recent major trials also yielded comparable stroke rates for on- and off-pump CABG (off-pump: 1.4%; on-pump: 1.7%; OR 0.87 [0.64-1.20]).  Within recent prospective randomized multicenter trials off-pump CABG did not result in lower stroke rates. The possible intrinsic benefit of off-pump CABG may be offset by the complexity of the operative therapy as well as the multiple pathomechanisms involved in perioperative stroke. Georg Thieme Verlag KG Stuttgart · New York.

  16. Fall in homicides in the city of São Paulo: an exploratory analysis of possible determinants.

    Science.gov (United States)

    Peres, Maria Fernanda Tourinho; de Almeida, Juliana Feliciano; Vicentin, Diego; Cerda, Magdalena; Cardia, Nancy; Adorno, Sérgio

    2011-12-01

    Throughout the first decade of the 2000s the homicide mortality rate (HMR) showed a significant reduction in the state and the city of São Paulo (MSP). The aim of this study is to describe the trend of HMR, socio-demographic indicators, and the investment in social and public security, and to analyze the correlation between HMR and independent variables in the MSP between 1996 and 2008. An exploratory time series ecological study was conducted. The following variables were included: HMR per 100,000 inhabitants, socio-demographic indicators, and investments in social and public security. The moving-averages for all variables were calculated and trends were analyzed through Simple Linear Regression models. Annual percentage changes, the average annual change and periodic percentage changes were calculated for all variables, and the associations between annual percentage changes were tested by Spearman's correlation analysis. Correlations were found for the proportion of youth in the population (r = 0.69), unemployment rate (r = 0.60), State budget for education and culture (r = 0.87) and health and sanitation (r = 0.56), municipal (r = 0.68) and State (r = 0.53) budget for Public Security, firearms seized (r = 0.69) and the incarceration rate (r = 0.71). The results allow us to support the hypothesis that demographic changes, acceleration of the economy, in particular the fall in unemployment, investment in social policies and changes in public security policies act synergistically to reduce HMR in São Paulo. Complex models of analysis, incorporating the joint action of different potential explanatory variables, should be developed.

  17. Exploratory and confirmatory factor analysis of the Adolescent Motivation to Cook Questionnaire: A Self-Determination Theory instrument.

    Science.gov (United States)

    Miketinas, Derek; Cater, Melissa; Bailey, Ariana; Craft, Brittany; Tuuri, Georgianna

    2016-10-01

    Increasing adolescents' motivation and competence to cook may improve diet quality and reduce the risk for obesity and chronic diseases. The objective of this study was to develop an instrument to measure adolescents' intrinsic motivation to prepare healthy foods and the four psychological needs that facilitate motivation identified by the Self Determination Theory (SDT). Five hundred ninety-three high school students (62.7% female) were recruited to complete the survey. Participants indicated to what extent they agreed or disagreed with 25 statements pertaining to intrinsic motivation and perceived competence to cook, and their perceived autonomy support, autonomy, and relatedness to teachers and classmates. Data were analyzed using exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and internal consistency reliability. EFA returned a five-factor structure explaining 65.3% of the variance; and CFA revealed that the best model fit was a five-factor structure (χ2 = 524.97 (265); Comparative Fit Index = 0.93; RMSEA = 0.056; and SRMR = 0.04). The sub-scales showed good internal consistency (Intrinsic Motivation: α = 0.94; Perceived Competence: α = 0.92; Autonomy Support: α = 0.94; Relatedness: α = 0.90; and Autonomy: α = 0.85). These results support the application of the Adolescent Motivation to Cook Questionnaire to measure adolescents' motivation and perceived competence to cook, autonomy support by their instructor, autonomy in the classroom, and relatedness to peers. Further studies are needed to investigate whether this instrument can measure change in cooking intervention programs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Haemodynamic response to crystalloids or colloids in shock: an exploratory subgroup analysis of a randomised controlled trial.

    Science.gov (United States)

    Heming, Nicholas; Elatrous, Souheil; Jaber, Samir; Dumenil, Anne Sylvie; Cousson, Joël; Forceville, Xavier; Kimmoun, Antoine; Trouillet, Jean Louis; Fichet, Jérôme; Anguel, Nadia; Darmon, Michael; Martin, Claude; Chevret, Sylvie; Annane, Djillali

    2017-10-06

    To compare the haemodynamic effect of crystalloids and colloids during acute severe hypovolaemic shock. Exploratory subgroup analysis of a multicentre randomised controlled trial (Colloids Versus Crystalloids for the Resuscitation of the Critically Ill, CRISTAL, ClinicalTrials.gov NCT00318942). CRISTAL was conducted in intensive care units in Europe, North Africa and Canada. Current analysis included all patients who had a pulmonary artery catheter in place at randomisation. 220 patients (117 received crystalloids vs 103 colloids) underwent pulmonary artery catheterisation. Crystalloids versus colloids for fluid resuscitation in hypovolaemic shock. Haemodynamic data were collected at the time of randomisation and subsequently on days 1, 2, 3, 4, 5, 6 and 7. Median cumulative volume of fluid administered during the first 7 days was higher in the crystalloids group than in the colloids group (3500 (2000-6000) vs 2500 (1000-4000) mL, p=0.01). Patients in the colloids arm exhibited a lower heart rate over time compared with those allocated to the crystalloids arm (p=0.014). There was no significant difference in Cardiac Index (p=0.053), mean blood pressure (p=0.4), arterial lactates (p=0.9) or global Sequential Organ Failure Assessment score (p=0.3) over time between arms. During acute severe hypovolaemic shock, patients monitored by a pulmonary artery catheter achieved broadly similar haemodynamic outcomes, using lower volumes of colloids than crystalloids. The heart rate was lower in the colloids arm. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  19. Dimensions of insight in schizophrenia: Exploratory factor analysis of items from multiple self- and interviewer-rated measures of insight.

    Science.gov (United States)

    Konsztowicz, Susanna; Schmitz, Norbert; Lepage, Martin

    2018-03-10

    Insight in schizophrenia is regarded as a multidimensional construct that comprises aspects such as awareness of the disorder and recognition of the need for treatment. The proposed number of underlying dimensions of insight is variable in the literature. In an effort to identify a range of existing dimensions of insight, we conducted a factor analysis on combined items from multiple measures of insight. We recruited 165 participants with enduring schizophrenia (treated for >3years). Exploratory factor analysis was conducted on itemized scores from two interviewer-rated measures of insight: the Schedule for the Assessment of Insight-Expanded and the abbreviated Scale to assess Unawareness of Mental Disorder; and two self-report measures: the Birchwood Insight Scale and the Beck Cognitive Insight Scale. A five-factor solution was selected as the best-fitting model, with the following dimensions of insight: 1) awareness of illness and the need for treatment; 2) awareness and attribution of symptoms and consequences; 3) self-certainty; 4) self-reflectiveness for objectivity and fallibility; and 5) self-reflectiveness for errors in reasoning and openness to feedback. Insight in schizophrenia is a multidimensional construct comprised of distinct clinical and cognitive domains of awareness. Multiple measures of insight, both clinician- and self-rated, are needed to capture all of the existing dimensions of insight. Future exploration of associations between the various dimensions and their potential determinants will facilitate the development of clinically useful models of insight and effective interventions to improve outcome. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. The structure of the symptoms of major depression: exploratory and confirmatory factor analysis in depressed Han Chinese women.

    Science.gov (United States)

    Li, Y; Aggen, S; Shi, S; Gao, J; Li, Y; Tao, M; Zhang, K; Wang, X; Gao, C; Yang, L; Liu, Y; Li, K; Shi, J; Wang, G; Liu, L; Zhang, J; Du, B; Jiang, G; Shen, J; Zhang, Z; Liang, W; Sun, J; Hu, J; Liu, T; Wang, X; Miao, G; Meng, H; Li, Y; Hu, C; Li, Y; Huang, G; Li, G; Ha, B; Deng, H; Mei, Q; Zhong, H; Gao, S; Sang, H; Zhang, Y; Fang, X; Yu, F; Yang, D; Liu, T; Chen, Y; Hong, X; Wu, W; Chen, G; Cai, M; Song, Y; Pan, J; Dong, J; Pan, R; Zhang, W; Shen, Z; Liu, Z; Gu, D; Wang, X; Liu, X; Zhang, Q; Flint, J; Kendler, K S

    2014-05-01

    The symptoms of major depression (MD) are clinically diverse. Do they form coherent factors that might clarify the underlying nature of this important psychiatric syndrome? Symptoms at lifetime worst depressive episode were assessed at structured psychiatric interview in 6008 women of Han Chinese descent, age ⩾30 years with recurrent DSM-IV MD. Exploratory factor analysis (EFA) and confirmatoryfactor analysis (CFA) were performed in Mplus in random split-half samples. The preliminary EFA results were consistently supported by the findings from CFA. Analyses of the nine DSM-IV MD symptomatic A criteria revealed two factors loading on: (i) general depressive symptoms; and (ii) guilt/suicidal ideation. Examining 14 disaggregated DSM-IV criteria revealed three factors reflecting: (i) weight/appetite disturbance; (ii) general depressive symptoms; and (iii) sleep disturbance. Using all symptoms (n = 27), we identified five factors that reflected: (i) weight/appetite symptoms; (ii) general retarded depressive symptoms; (iii) atypical vegetative symptoms; (iv) suicidality/hopelessness; and (v) symptoms of agitation and anxiety. MD is a clinically complex syndrome with several underlying correlated symptom dimensions. In addition to a general depressive symptom factor, a complete picture must include factors reflecting typical/atypical vegetative symptoms, cognitive symptoms (hopelessness/suicidal ideation), and an agitated symptom factor characterized by anxiety, guilt, helplessness and irritability. Prior cross-cultural studies, factor analyses of MD in Western populations and empirical findings in this sample showing risk factor profiles similar to those seen in Western populations suggest that our results are likely to be broadly representative of the human depressive syndrome.

  1. Exploratory data mining analysis identifying subgroups of patients with depression who are at high risk for suicide.

    Science.gov (United States)

    Ilgen, Mark A; Downing, Karen; Zivin, Kara; Hoggatt, Katherine J; Kim, H Myra; Ganoczy, Dara; Austin, Karen L; McCarthy, John F; Patel, Jignesh M; Valenstein, Marcia

    2009-11-01

    Although prior research has identified a number of separate risk factors for suicide among patients with depression, little is known about how these factors may interact to modify suicide risk. Using an empirically based decision tree analysis for a large national sample of Veterans Affairs (VA) health system patients treated for depression, we identified subgroups with particularly high or low rates of suicide. We identified 887,859 VA patients treated for depression between April 1, 1999, and September 30, 2004. Randomly splitting the data into 2 samples (primary and replication samples), we developed a decision tree for the primary sample using recursive partitioning. We then tested whether the groups developed within the primary sample were associated with increased suicide risk in the replication sample. The exploratory data analysis produced a decision tree with subgroups of patients at differing levels of risk for suicide. These were identified by a combination of factors including a co-occurring substance use disorder diagnosis, male sex, African American race, and psychiatric hospitalization in the past year. The groups developed as part of the decision tree accurately discriminated between those with and without suicide in the replication sample. The patients at highest risk for suicide were those with a substance use disorder who were non-African American and had an inpatient psychiatric stay within the past 12 months. Study findings suggest that the identification of depressed patients at increased risk for suicide is improved through the examination of higher order interactions between potential risk factors. Copyright 2009 Physicians Postgraduate Press, Inc.

  2. An Exploratory Energy Analysis of Electrochromic Windows in Small and Medium Office Buildings - Simulated Results Using EnergyPlus

    Energy Technology Data Exchange (ETDEWEB)

    Belzer, David B.

    2010-08-01

    The Department of Energy’s (DOE) Building Technologies Program (BTP) has had an active research program in supporting the development of electrochromic (EC) windows. Electrochromic glazings used in these windows have the capability of varying the transmittance of light and heat in response to an applied voltage. This dynamic property allows these windows to reduce lighting, cooling, and heating energy in buildings where they are employed. The exploratory analysis described in this report examined three different variants of EC glazings, characterized by the amount of visible light and solar heat gain (as measured by the solar heat gain coefficients [SHGC] in their “clear” or transparent states). For these EC glazings, the dynamic range of the SHGC’s between their “dark” (or tinted) state and the clear state were: (0.22 - 0.70, termed “high” SHGC); (0.16 - 0.39, termed “low” SHGC); and (0.13 - 0.19; termed “very low” SHGC). These glazings are compared to conventional (static) glazing that meets the ASHRAE Standard 90.1-2004 energy standard for five different locations in the U.S. All analysis used the EnergyPlus building energy simulation program for modeling EC windows and alternative control strategies. The simulations were conducted for a small and a medium office building, where engineering specifications were taken from the set of Commercial Building Benchmark building models developed by BTP. On the basis of these simulations, total source-level savings in these buildings were estimated to range between 2 to 7%, depending on the amount of window area and building location.

  3. Taking Advertising Literacy to a Higher Level: An Exploratory Multilevel Analysis of Children's Advertising Literacy

    OpenAIRE

    De Pauw, Pieter; Cauberghe, Veroline; Hudders, Liselot

    2017-01-01

    As few studies focus on how children’s coping with advertising is affected by their environment, the present study uses multilevel analysis to explore the role of both primary (i.e. parents) and secondary socializing agents (i.e. classmates, teachers) in children’s advertising literacy. The results show that children’s cognitive advertising literacy and attitudes toward advertising are to a large extent determined by class-level processes. Their moral advertising literacy is a more individual...

  4. Method for exploratory cluster analysis and visualisation of single-trial ERP ensembles.

    Science.gov (United States)

    Williams, N J; Nasuto, S J; Saddy, J D

    2015-07-30

    The validity of ensemble averaging on event-related potential (ERP) data has been questioned, due to its assumption that the ERP is identical across trials. Thus, there is a need for preliminary testing for cluster structure in the data. We propose a complete pipeline for the cluster analysis of ERP data. To increase the signal-to-noise (SNR) ratio of the raw single-trials, we used a denoising method based on Empirical Mode Decomposition (EMD). Next, we used a bootstrap-based method to determine the number of clusters, through a measure called the Stability Index (SI). We then used a clustering algorithm based on a Genetic Algorithm (GA) to define initial cluster centroids for subsequent k-means clustering. Finally, we visualised the clustering results through a scheme based on Principal Component Analysis (PCA). After validating the pipeline on simulated data, we tested it on data from two experiments - a P300 speller paradigm on a single subject and a language processing study on 25 subjects. Results revealed evidence for the existence of 6 clusters in one experimental condition from the language processing study. Further, a two-way chi-square test revealed an influence of subject on cluster membership. Our analysis operates on denoised single-trials, the number of clusters are determined in a principled manner and the results are presented through an intuitive visualisation. Given the cluster structure in some experimental conditions, we suggest application of cluster analysis as a preliminary step before ensemble averaging. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Exploratory Factor Analysis of Self-Reported Symptoms in a Large, Population-Based Military Cohort

    Science.gov (United States)

    2010-10-15

    dreams of past experiences” also had loadings of at least 0.80 for this factor. 2. Chest pain, short breath, etc (5.7 percent of total variance...analysis suggests that it could be a manifestation of it or another condition associated with anxiety such as fibromyalgia [33]. Factor 3...military population. However, general muscle pain can accompany many other illnesses, such as infectious diseases, autoimmune disorders, fibromyalgia

  6. Impact of additive manufacturing on supply chain network structures –an exploratory case study analysis

    OpenAIRE

    Oettmeier, Katrin

    2016-01-01

    Purpose: This paper demonstrates that additive manufacturing (AM), as a technological driver, has the potential to change the structural composition of entire supply chains. The research comprises a first, systematic analysis about the impact of AM on the network structures in engineer-to-order supply chains. Research Approach: The paper pursues an inductive research approach. Building on contingency theory as well as on general systems theory, and using extensive case studies from the...

  7. Signs and Symptoms of Acoustic Neuroma at Initial Presentation: An Exploratory Analysis.

    Science.gov (United States)

    Foley, Robert W; Shirazi, Shahram; Maweni, Robert M; Walsh, Kay; McConn Walsh, Rory; Javadpour, Mohsen; Rawluk, Daniel

    2017-11-15

    Introduction The objective of this study was to describe the most common clinical features associated with an acoustic neuroma diagnosis and to identify those features associated with larger tumour size at initial diagnosis. Methods The clinical information of 945 consecutive patients diagnosed with acoustic neuroma at a single centre between 1992 and 2015 was analysed. Clinical features were examined and the relationship between these features and tumour size (>2.5 cm) was analysed using descriptive statistics and logistic regression analysis. Statistical analysis was performed in R version 3.1.1. Results The most common presenting symptom was a unilateral hearing loss in 752 patients (80%), with a progressive pattern in 90% of these cases. The second most common presenting symptom was unilateral tinnitus, accounting for 6.3%, while ataxia, vertigo and headache accounted for 3.8%, 3.4% and 2%, respectively. The diagnosis of acoustic neuroma was an incidental finding in 20 patients (2.1%). Temporal analysis demonstrated a downward trend in the number of patients presenting with hearing loss and an increased proportion of patients presenting with other symptoms. On multivariate analysis, larger tumour size was associated with abnormal tandem gait (odds ratio 8.9, p=0.02), subjective facial weakness (odds ratio 5.3, ppresent with the classic, progressive, unilateral hearing loss. However, the pattern of presentation in acoustic neuroma patients is changing. Features in the history indicative of a larger tumour are headaches and subjective facial weakness, whilst concerning features on examination are abnormal tandem gait and altered facial sensation.

  8. An exploratory game-theoretic analysis of biomass electricity generation supply chain

    International Nuclear Information System (INIS)

    Nasiri, Fuzhan; Zaccour, Georges

    2009-01-01

    This study proposes a game-theoretic approach to model and analyze the process of utilizing biomass for power generation considering three players: distributor, facility developer, and participating farmer. We characterize the Nash equilibrium of the sequential game and discuss its features. A special attention is devoted to the analysis of the impact of incentives and initial target on the equilibrium, in which the biomass is part of electricity production.

  9. SOMFlow: Guided Exploratory Cluster Analysis with Self-Organizing Maps and Analytic Provenance.

    Science.gov (United States)

    Sacha, Dominik; Kraus, Matthias; Bernard, Jurgen; Behrisch, Michael; Schreck, Tobias; Asano, Yuki; Keim, Daniel A

    2018-01-01

    Clustering is a core building block for data analysis, aiming to extract otherwise hidden structures and relations from raw datasets, such as particular groups that can be effectively related, compared, and interpreted. A plethora of visual-interactive cluster analysis techniques has been proposed to date, however, arriving at useful clusterings often requires several rounds of user interactions to fine-tune the data preprocessing and algorithms. We present a multi-stage Visual Analytics (VA) approach for iterative cluster refinement together with an implementation (SOMFlow) that uses Self-Organizing Maps (SOM) to analyze time series data. It supports exploration by offering the analyst a visual platform to analyze intermediate results, adapt the underlying computations, iteratively partition the data, and to reflect previous analytical activities. The history of previous decisions is explicitly visualized within a flow graph, allowing to compare earlier cluster refinements and to explore relations. We further leverage quality and interestingness measures to guide the analyst in the discovery of useful patterns, relations, and data partitions. We conducted two pair analytics experiments together with a subject matter expert in speech intonation research to demonstrate that the approach is effective for interactive data analysis, supporting enhanced understanding of clustering results as well as the interactive process itself.

  10. Device for high spatial resolution chemical analysis of a sample and method of high spatial resolution chemical analysis

    Science.gov (United States)

    Van Berkel, Gary J.

    2015-10-06

    A system and method for analyzing a chemical composition of a specimen are described. The system can include at least one pin; a sampling device configured to contact a liquid with a specimen on the at least one pin to form a testing solution; and a stepper mechanism configured to move the at least one pin and the sampling device relative to one another. The system can also include an analytical instrument for determining a chemical composition of the specimen from the testing solution. In particular, the systems and methods described herein enable chemical analysis of specimens, such as tissue, to be evaluated in a manner that the spatial-resolution is limited by the size of the pins used to obtain tissue samples, not the size of the sampling device used to solubilize the samples coupled to the pins.

  11. Landscape Change Index as a Tool for Spatial Analysis

    Science.gov (United States)

    Krajewski, Piotr; Solecka, Iga; Barbara-Mastalska-Cetera

    2017-10-01

    This study analysed spatial and temporal changes in protected landscape of Ślęża Landscape Park in Poland, covering an area of 7724 ha. The main objective was to determine level of landscape change of the research area after Polish accession to European Union by comparing land-cover maps from 2004, 2009 and 2014. With the use of prepared land cover maps, we developed a database of the surface of the main elements constituting the background landscape of the research area. The data obtained made it feasible to assess the level of change in two different periods of time (2004 - 2009 and 2009 - 2014) by means of the landscape change index (LCI). This indicator is described by one value which is the result of all the change types taking place in the background landscape in a given period of time. Comparing the index of different parts of Ślęża Landscape Park helped to identify areas where the landscape changes were the highest and areas where the changes were hardly noticeable. The results show that when we take into account whole research area landscape changes are much more intense in the second of the analysed periods of time (2009 - 2014) (LCI=1,91) then in years 2004 - 2009 (LCI=0,71). The same analysis was done for each part of municipalities located within the Park. This made it possible to determine which part of the park is the most threatened by spatial transformations. In this context, it should be emphasized that the highest rates of landscape changes were recorded in the municipalities where the largest new residential area was located – in the municipalities Sobótka and Łagiewniki. Whereas municipality Dzierżoniów with a high percentage of forests inside the Park and unchanging area of arable land have the lowest landscape change index.

  12. Study of academic achievements using spatial analysis tools

    Science.gov (United States)

    González, C.; Velilla, C.; Sánchez-Girón, V.

    2012-04-01

    In the 2010/12 academic year the College of Agricultural Engineering of the Technical University of Madrid implemented three new degrees all of them adapted to the European Space for Higher Education. These degrees are namely: Graduate in Agricultural Engineering and Science, Graduate in Food Engineering and Graduate in Agro-Environmental Engineering. A total of 382 new incoming students were finally registered and a survey study was carried out with these students about their academic achievement with the aim of finding the level of dependence among the following variables: the final mark in their secondary studies, the option followed in the secondary studies (Art, Science and Technology, and Humanities and Social Sciences), the mark obtained in the entering examination to the university and in which of the two opportunities per year this examination takes place the latter mark was obtained. Similarly, another group of 77 students were evaluated independently to the former group. These students were those entering the College in the previous academic year (2009/10) and decided to change their curricula to the new ones. Subsequently, using the tools of spatial analysis of geographic information systems, we analyzed the possible relationship between the success or failure at school and the socioeconomic profile of new students in a grade. For this purpose every student was referenced assigning UTM coordinates to their postal addresses. Furthermore, all students' secondary schools were geographically coded considering their typology (public, private, and private subsidized) and fares. Each student was represented by its average geometric point in order to be correlated to their respective record. Following this procedure a map of the performance of each student could be drawn. This map can be used as a reference system, as it includes variables as the distance from the student home to the College, that can be used as a tool to calculate the probability of success or

  13. Tucker Tensor analysis of Matern functions in spatial statistics

    KAUST Repository

    Litvinenko, Alexander

    2018-03-09

    In this work, we describe advanced numerical tools for working with multivariate functions and for the analysis of large data sets. These tools will drastically reduce the required computing time and the storage cost, and, therefore, will allow us to consider much larger data sets or finer meshes. Covariance matrices are crucial in spatio-temporal statistical tasks, but are often very expensive to compute and store, especially in 3D. Therefore, we approximate covariance functions by cheap surrogates in a low-rank tensor format. We apply the Tucker and canonical tensor decompositions to a family of Matern- and Slater-type functions with varying parameters and demonstrate numerically that their approximations exhibit exponentially fast convergence. We prove the exponential convergence of the Tucker and canonical approximations in tensor rank parameters. Several statistical operations are performed in this low-rank tensor format, including evaluating the conditional covariance matrix, spatially averaged estimation variance, computing a quadratic form, determinant, trace, loglikelihood, inverse, and Cholesky decomposition of a large covariance matrix. Low-rank tensor approximations reduce the computing and storage costs essentially. For example, the storage cost is reduced from an exponential O(n^d) to a linear scaling O(drn), where d is the spatial dimension, n is the number of mesh points in one direction, and r is the tensor rank. Prerequisites for applicability of the proposed techniques are the assumptions that the data, locations, and measurements lie on a tensor (axes-parallel) grid and that the covariance function depends on a distance, ||x-y||.

  14. An Object-Based Image Analysis Approach for Detecting Penguin Guano in very High Spatial Resolution Satellite Images

    Directory of Open Access Journals (Sweden)

    Chandi Witharana

    2016-04-01

    Full Text Available The logistical challenges of Antarctic field work and the increasing availability of very high resolution commercial imagery have driven an interest in more efficient search and classification of remotely sensed imagery. This exploratory study employed geographic object-based analysis (GEOBIA methods to classify guano stains, indicative of chinstrap and Adélie penguin breeding areas, from very high spatial resolution (VHSR satellite imagery and closely examined the transferability of knowledge-based GEOBIA rules across different study sites focusing on the same semantic class. We systematically gauged the segmentation quality, classification accuracy, and the reproducibility of fuzzy rules. A master ruleset was developed based on one study site and it was re-tasked “without adaptation” and “with adaptation” on candidate image scenes comprising guano stains. Our results suggest that object-based methods incorporating the spectral, textural, spatial, and contextual characteristics of guano are capable of successfully detecting guano stains. Reapplication of the master ruleset on candidate scenes without modifications produced inferior classification results, while adapted rules produced comparable or superior results compared to the reference image. This work provides a road map to an operational “image-to-assessment pipeline” that will enable Antarctic wildlife researchers to seamlessly integrate VHSR imagery into on-demand penguin population census.

  15. French fair trade coffee buyers' purchasing motives: An exploratory study using means-end chains analysis

    DEFF Research Database (Denmark)

    de Ferran, Florence; Grunert, Klaus G.

    2007-01-01

    . In this paper, we examine the motives and the values underlying this purchase through a laddering methodology with 54 French fair trade coffee purchasers. A quantitative analysis of the ladders allows us to define several groups of motives that are socially and individually oriented. Moreover, our results......Considering the growth of fair trade product consumption in European countries and the expansion of its distribution to different kinds of distribution networks in reply to increasing consumer sensitivity to the ethical characteristics of a product, it becomes important to understand it better...

  16. Persistent solar signatures in cloud cover: spatial and temporal analysis

    International Nuclear Information System (INIS)

    Voiculescu, M; Usoskin, I

    2012-01-01

    A consensus regarding the impact of solar variability on cloud cover is far from being reached. Moreover, the impact of cloud cover on climate is among the least understood of all climate components. This motivated us to analyze the persistence of solar signals in cloud cover for the time interval 1984–2009, covering two full solar cycles. A spatial and temporal investigation of the response of low, middle and high cloud data to cosmic ray induced ionization (CRII) and UV irradiance (UVI) is performed in terms of coherence analysis of the two signals. For some key geographical regions the response of clouds to UVI and CRII is persistent over the entire time interval indicating a real link. In other regions, however, the relation is not consistent, being intermittent or out of phase, suggesting that some correlations are spurious. The constant in phase or anti-phase relationship between clouds and solar proxies over some regions, especially for low clouds with UVI and CRII, middle clouds with UVI and high clouds with CRII, definitely requires more study. Our results show that solar signatures in cloud cover persist in some key climate-defining regions for the entire time period and supports the idea that, if existing, solar effects are not visible at the global level and any analysis of solar effects on cloud cover (and, consequently, on climate) should be done at the regional level. (letter)

  17. Signal Adaptive System for Space/Spatial-Frequency Analysis

    Directory of Open Access Journals (Sweden)

    Veselin N. Ivanović

    2009-01-01

    Full Text Available This paper outlines the development of a multiple-clock-cycle implementation (MCI of a signal adaptive two-dimensional (2D system for space/spatial-frequency (S/SF signal analysis. The design is based on a method for improved S/SF representation of the analyzed 2D signals, also proposed here. The proposed MCI design optimizes critical design performances related to hardware complexity, making it a suitable system for real time implementation on an integrated chip. Additionally, the design allows the implemented system to take a variable number of clock cycles (CLKs (the only necessary ones regarding desirable—2D Wigner distribution-presentation of autoterms in different frequency-frequency points during the execution. This ability represents a major advantage of the proposed design which helps to optimize the time required for execution and produce an improved, cross-terms-free S/SF signal representation. The design has been verified by a field-programmable gate array (FPGA circuit design, capable of performing S/SF analysis of 2D signals in real time.

  18. SDSS Log Viewer: visual exploratory analysis of large-volume SQL log data

    Science.gov (United States)

    Zhang, Jian; Chen, Chaomei; Vogeley, Michael S.; Pan, Danny; Thakar, Ani; Raddick, Jordan

    2012-01-01

    User-generated Structured Query Language (SQL) queries are a rich source of information for database analysts, information scientists, and the end users of databases. In this study a group of scientists in astronomy and computer and information scientists work together to analyze a large volume of SQL log data generated by users of the Sloan Digital Sky Survey (SDSS) data archive in order to better understand users' data seeking behavior. While statistical analysis of such logs is useful at aggregated levels, efficiently exploring specific patterns of queries is often a challenging task due to the typically large volume of the data, multivariate features, and data requirements specified in SQL queries. To enable and facilitate effective and efficient exploration of the SDSS log data, we designed an interactive visualization tool, called the SDSS Log Viewer, which integrates time series visualization, text visualization, and dynamic query techniques. We describe two analysis scenarios of visual exploration of SDSS log data, including understanding unusually high daily query traffic and modeling the types of data seeking behaviors of massive query generators. The two scenarios demonstrate that the SDSS Log Viewer provides a novel and potentially valuable approach to support these targeted tasks.

  19. Nutrition Care after Discharge from Hospital: An Exploratory Analysis from the More-2-Eat Study.

    Science.gov (United States)

    Laur, Celia; Curtis, Lori; Dubin, Joel; McNicholl, Tara; Valaitis, Renata; Douglas, Pauline; Bell, Jack; Bernier, Paule; Keller, Heather

    2018-01-20

    Many patients leave hospital in poor nutritional states, yet little is known about the post-discharge nutrition care in which patients are engaged. This study describes the nutrition-care activities 30-days post-discharge reported by patients and what covariates are associated with these activities. Quasi-randomly selected patients recruited from 5 medical units across Canada ( n = 513) consented to 30-days post-discharge data collection with 48.5% ( n = 249) completing the telephone interview. Use of nutrition care post-discharge was reported and bivariate analysis completed with relevant covariates for the two most frequently reported activities, following recommendations post-discharge or use of oral nutritional supplements (ONS). A total of 42% ( n = 110) received nutrition recommendations at hospital discharge, with 65% ( n = 71/110) of these participants following those recommendations; 26.5% ( n = 66) were taking ONS after hospitalization. Participants who followed recommendations were more likely to report following a special diet ( p = 0.002), different from before their hospitalization ( p = 0.008), compared to those who received recommendations, but reported not following them. Patients taking ONS were more likely to be at nutrition risk ( p eating enough to meet their body's needs ( p = 0.005). This analysis provides new insights on nutrition-care post-discharge.

  20. DataHub - Science data management in support of interactive exploratory analysis

    Science.gov (United States)

    Handley, Thomas H., Jr.; Rubin, Mark R.

    1993-01-01

    DataHub addresses four areas of significant need: scientific visualization and analysis; science data management; interactions in a distributed, heterogeneous environment; and knowledge-based assistance for these functions. The fundamental innovation embedded within the DataHub is the integration of three technologies, viz. knowledge-based expert systems, science visualization, and science data management. This integration is based on a concept called the DataHub. With the DataHub concept, science investigators are able to apply a more complete solution to all nodes of a distributed system. Both computational nodes and interactive nodes are able to effectively and efficiently use the data services (access, retrieval, update, etc.) in a distributed, interdisciplinary information system in a uniform and standard way. This allows the science investigators to concentrate on their scientific endeavors, rather than to involve themselves in the intricate technical details of the systems and tools required to accomplish their work. Thus, science investigators need not be programmers. The emphasis is on the definition and prototyping of system elements with sufficient detail to enable data analysis and interpretation leading to information. The DataHub includes all the required end-to-end components and interfaces to demonstrate the complete concept.

  1. DataHub: Science data management in support of interactive exploratory analysis

    Science.gov (United States)

    Handley, Thomas H., Jr.; Rubin, Mark R.

    1993-01-01

    The DataHub addresses four areas of significant needs: scientific visualization and analysis; science data management; interactions in a distributed, heterogeneous environment; and knowledge-based assistance for these functions. The fundamental innovation embedded within the DataHub is the integration of three technologies, viz. knowledge-based expert systems, science visualization, and science data management. This integration is based on a concept called the DataHub. With the DataHub concept, science investigators are able to apply a more complete solution to all nodes of a distributed system. Both computational nodes and interactives nodes are able to effectively and efficiently use the data services (access, retrieval, update, etc), in a distributed, interdisciplinary information system in a uniform and standard way. This allows the science investigators to concentrate on their scientific endeavors, rather than to involve themselves in the intricate technical details of the systems and tools required to accomplish their work. Thus, science investigators need not be programmers. The emphasis on the definition and prototyping of system elements with sufficient detail to enable data analysis and interpretation leading to information. The DataHub includes all the required end-to-end components and interfaces to demonstrate the complete concept.

  2. An exploratory analysis for Lean and Six Sigma implementation in hospitals: Together is better?

    Science.gov (United States)

    Lee, Jung Young; McFadden, Kathleen L; Gowen, Charles R

    2016-12-22

    Despite the increasing interest for Lean and Six Sigma implementations in hospitals, there has been little empirical evidence that goes beyond descriptive case studies to address the current status and the effectiveness of the implementations. The aim of this study was to explore existing patterns of Lean and Six Sigma implementation in U.S. hospitals and compare the performance of the different patterns. We collected data from 215 U.S. hospitals via a survey that includes measurement items developed from related literature. Using the cross-sectional data, we conducted a cluster analysis, followed by t tests, chi-square tests, and regression analyses for cluster verification. The cluster analysis identifies two clusters, a Moderate Six Sigma group and a Lean Six Sigma group. Results show that the Lean Six Sigma group outperforms the Moderate Six Sigma group across many performance dimensions: responsiveness capability, patient safety, and possibly cost saving. In addition, the Lean Six Sigma group tends to be composed of larger, private teaching hospitals located in more urban areas, and they employ more resources for quality improvement. Our research contributes to the quality management literature by supporting the possible complementary relationship between Lean and Six Sigma in hospitals. Our study encourages practitioners and managers to pay more attention to Lean implementation. Although Lean seems to be conducted in a limited fashion in many hospitals, it should be expanded and combined with Six Sigma for better results.

  3. An exploratory data analysis of electroencephalograms using the functional boxplots approach

    KAUST Repository

    Ngo, Duy

    2015-08-19

    Many model-based methods have been developed over the last several decades for analysis of electroencephalograms (EEGs) in order to understand electrical neural data. In this work, we propose to use the functional boxplot (FBP) to analyze log periodograms of EEG time series data in the spectral domain. The functional bloxplot approach produces a median curve—which is not equivalent to connecting medians obtained from frequency-specific boxplots. In addition, this approach identifies a functional median, summarizes variability, and detects potential outliers. By extending FBPs analysis from one-dimensional curves to surfaces, surface boxplots are also used to explore the variation of the spectral power for the alpha (8–12 Hz) and beta (16–32 Hz) frequency bands across the brain cortical surface. By using rank-based nonparametric tests, we also investigate the stationarity of EEG traces across an exam acquired during resting-state by comparing the spectrum during the early vs. late phases of a single resting-state EEG exam.

  4. Efficiency in Health Care Sector in Tamil Nadu (India: An Exploratory Analysis

    Directory of Open Access Journals (Sweden)

    Purohit BC

    2016-05-01

    Full Text Available Keeping in view the importance of efficiency in resource utilization in healthcare sector, we focus on efficiency of health care system at sub-state level (i.e., district level in India using Tamil Nadu state and its district level data for 2012-13. It being an economically advanced state, in terms of Infant Mortality Rate (IMR the state ranks second lowest among the Indian states. We explore the reasons for relative performance of different districts with Data Envelopment Analysis. We used IMR as output variables. Using Principal component analysis we tried a sub-set of variables which had low correlations. Thus three components with an Eigen value greater than one were used. These related to Total beds in ESI (Employees state Insurance scheme hospitals, Population per doctor of PHPM (Public Health and Preventive Medicine and Full Vaccination. The factor scores for these components were used for Data Envelopment Analysis (DEA. We have focused on CCR scores (or constant returns to scale technical efficiency, CRST score and efficiency rankings based on these are discussed. Thus our results pertaining to district level health system efficiency for Tamil Nadu state indicate that some of the districts have low efficiency in utilization of inputs like doctors and beds. There are also other districts which need more of these inputs which may enhance their output and efficiency. Thus it suggests that that the lowest performance of Kancheepuram district, for instance, is mainly owing to low availability of these health inputs as well as partly due to less efficient utilisation of inputs. It is also inferred that higher efficiency of Chennai is due to better availability of hospital beds and doctors per population. Among the factors external to health system, the statistical significance of an improved source of drinking water indicates that supportive input of better potable water supply helps to improve in general health status and thus reduce inter

  5. Polycystic ovary syndrome and mental disorders: a systematic review and exploratory meta-analysis

    Directory of Open Access Journals (Sweden)

    Blay SL

    2016-11-01

    Full Text Available Sergio Luís Blay,1 João Vicente Augusto Aguiar,2 Ives Cavalcante Passos3 1Department of Psychiatry, Federal University of São Paulo (Escola Paulista de Medicina – UNIFESP, São Paulo, SP, Brazil; 2Department of Psychiatry, Fortaleza University, Fortaleza, Ceará, Brazil; 3Laboratory of Molecular Psychiatry and Department of Psychiatry, Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil Background: The association between depression, anxiety, and polycystic ovary syndrome (PCOS is still unclear. Therefore, a systematic review and meta-analysis was conducted to assess the rates of comorbid psychiatric disorders among women with PCOS compared to women without it. Methods: PubMed/MEDLINE, Embase, PsycINFO, and Web of Science databases were searched from inception to November 27, 2015. Studies were eligible for inclusion if they were original reports in which the rates of mood (bipolar disorder, dysthymia, or major depressive disorder, obsessive–compulsive spectrum disorders, trauma- and stressor-related disorders, anxiety disorders or psychotic disorders, somatic symptom and related disorders, or eating disorders had been investigated among women with an established diagnosis of PCOS and compared with women without PCOS. Psychiatric diagnosis should have been established by means of a structured diagnostic interview or through a validated screening tool. Data were extracted and pooled using random effects models. Results: Six studies were included in the meta-analysis; of these, five reported the rates of anxiety and six provided data on the rates of depression. The rate of subjects with anxiety symptoms was higher in patients with PCOS compared to women without PCOS (odds ratio (OR =2.76; 95% confidence interval (CI 1.26 to 6.02; Log OR =1.013; P=0.011. The rate of subjects with depressive symptoms was higher in patients with PCOS compared to women without PCOS (OR =3.51; 95% CI 1.97 to 6.24; Log OR =1.255; P<0

  6. The impact of Australian ETS news on wholesale spot electricity prices: An exploratory analysis

    International Nuclear Information System (INIS)

    Chevallier, Julien

    2010-01-01

    This article investigates the impact of news concerning the development of emissions trading in Australia (such as the Carbon Pollution Reduction Scheme (CPRS)) on wholesale electricity spot prices, by using a database of 117 news announcements from December 1, 1998 to July 1, 2009. As power producers constitute the bulk of the participants of the proposed Australian emissions trading scheme, regulatory changes (about allocation, banking, coverage, targets) are indeed likely to affect the five interconnected electricity markets in New South Wales, Queensland, South Australia, Victoria, and Tasmania. We assess these effects with an ARMA(1,1)-GARCH(1,1) model, where daily electricity spot prices are regressed against exogenous variables in the mean and variance equations. This article constitutes the first empirical analysis of Australian ETS news effects on electricity wholesale spot prices. Our results show two asymmetric types of news effects, depending on their information content.

  7. An Exploratory Analysis of Sound Field Characteristics using the Impulse Response in a Car Cabin

    Directory of Open Access Journals (Sweden)

    Yoshiharu Soeta

    2018-03-01

    Full Text Available Sound environments in cars are becoming quieter and receiving attention because of the prevalence of low-noise engines such as hybrid and electric engines and the manifestation of automated driving. Although the car cabin has potential as a listening space, its acoustic quality has not been examined in detail. The present study investigated sound field characteristics in the car cabin using acoustic parameters obtained by impulse response analysis. In particular, effects of the passenger position, open windows and the use of an air conditioner on acoustic parameters were investigated. The passenger position affected the sound strength at low frequencies. Rear seats, except for the rear central seat, had lower interaural correlation than the front seats, suggesting that rear seats have more diffused sound fields. The opening of windows and use of air conditioners attenuated the ratio of early- and late-arriving energy at high frequencies, suggesting a loss of clarity for music.

  8. How safe is adventure tourism in New Zealand? An exploratory analysis.

    Science.gov (United States)

    Bentley, T; Page, S; Meyer, D; Chalmers, D; Laird, I

    2001-08-01

    The paper reports findings from a multidisciplinary programme of research, the major aims of which were to determine the nature and extent of the New Zealand adventure tourism injury problem. Analysis of hospital discharge and mortality data for a 15-year period identified adventure tourism-related activities as contributing to approximately 20% of overseas visitor injuries, and 22% of fatalities. Activities that commonly involve independent-unguided adventure tourism, notably mountaineering, skiing and tramping, contributed most to injury and fatality incidence. Horse riding and cycling activities were identified from hospital discharge data and adventure tourism operators' reported client injury-incidence, as the commercial adventure tourism activities most frequently involved in client injuries. Falls were the most common injury events, and a range of client, equipment, environmental and organisational risk factors were identified. Possible interventions to reduce injury risk among overseas and domestic adventure tourists are discussed.

  9. Exploratory Analysis of Dengue Fever Niche Variables within the Río Magdalena Watershed

    Directory of Open Access Journals (Sweden)

    Austin Stanforth

    2016-09-01

    Full Text Available Previous research on Dengue Fever have involved laboratory tests or study areas with less diverse temperature and elevation ranges than is found in Colombia; therefore, preliminary research was needed to identify location specific attributes of Dengue Fever transmission. Environmental variables derived from the Moderate Resolution Imaging Spectroradiometer (MODIS and Tropical Rainfall Measuring Mission (TRMM satellites were combined with population variables to be statistically compared against reported cases of Dengue Fever in the Río Magdalena watershed, Colombia. Three-factor analysis models were investigated to analyze variable patterns, including a population, population density, and empirical Bayesian estimation model. Results identified varying levels of Dengue Fever transmission risk, and environmental characteristics which support, and advance, the research literature. Multiple temperature metrics, elevation, and vegetation composition were among the more contributory variables found to identify future potential outbreak locations.

  10. The economic impacts of noxious facilities on wages and property values: An exploratory analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, L.A.; Hemphill, R.C.; Clark, D.E.

    1991-05-01

    Recent assessments of socioeconomic impacts resulting from the location of potentially hazardous facilities have concentrated on the issue of negative public perceptions and their resulting economic consequences. This report presents an analysis designed to answer the question: Can economic impacts resulting from negative perceptions of noxious facilities'' be identified and measured To identify the impacts of negative perceptions, data on noxious facilities sited throughout the United States were compiled, and secondary economic and demographic data sufficient to analyze the economic impacts on the surrounding study areas were assembled. This study uses wage rate and property value differentials to measure impacts on social welfare so that the extent to which noxious facilities and their associated activities have affected surrounding areas can be determined.

  11. The economic impacts of noxious facilities on wages and property values: An exploratory analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, L.A.; Hemphill, R.C.; Clark, D.E.

    1991-05-01

    Recent assessments of socioeconomic impacts resulting from the location of potentially hazardous facilities have concentrated on the issue of negative public perceptions and their resulting economic consequences. This report presents an analysis designed to answer the question: Can economic impacts resulting from negative perceptions of ``noxious facilities`` be identified and measured? To identify the impacts of negative perceptions, data on noxious facilities sited throughout the United States were compiled, and secondary economic and demographic data sufficient to analyze the economic impacts on the surrounding study areas were assembled. This study uses wage rate and property value differentials to measure impacts on social welfare so that the extent to which noxious facilities and their associated activities have affected surrounding areas can be determined.

  12. Sexual Risk Behavior among Male and Female Truant Youths: Exploratory, Multi-Group Latent Class Analysis.

    Science.gov (United States)

    Dembo, Richard; Wareham, Jennifer; Krupa, Julie; Winters, Ken C

    2015-12-01

    Little is known of sexual risk behaviors among truant youths across gender. This study utilized latent class analysis to examined heterogeneity of sexual risk behaviors across gender among a sample of 300 truant adolescents. Results revealed two latent subgroups within gender: low vs. high sexual risk behaviors. There were gender differences in baseline covariates of sexual risk behaviors, with male truants in higher risk group experiencing ADHD (attention deficit hyperactivity disorder) problems, and female truants in higher risk group experienced marijuana use and depression symptoms. African-American race was a significant covariate for high sexual risk behaviors for both genders. Service and practice implications of sexual risk issues of truant youth are discussed.

  13. Exploratory trend and pattern analysis of Caorso plant through the Tenda program

    International Nuclear Information System (INIS)

    Barsanti, P.; Tabellini, M.

    1990-01-01

    The eleven years of operating experience of Caorso NPP supply a consistent and homogeneous data set of events involving safety-related systems and components. The above data, periodically transmitted to the Italian regulatory body (ENEA/DISP) by the utility (ENEL), as required by the italian rules and regulations, are collected into a computerised Data Bank (SEME). A PC software package (TENDA), which uses, as input, the codes from the SEME Data Bank, was set-up inside ENEA/DISP, with the aim to perform automatic Trend and pattern Analysis. Graphic software was also utilized for a more self-explaining presentation of the results. They are being utilized as input for subsequent studies related to other plants (e.g. PRA and living PRA as well). Plans for the utilization of the TENDA program for new plants and in the conventional area are now under consideration

  14. Eating patterns in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil: an exploratory analysis

    Directory of Open Access Journals (Sweden)

    Letícia de Oliveira Cardoso

    2016-01-01

    Full Text Available Abstract: The food consumption of 15,071 public employees was analyzed in six Brazilian cities participating in the baseline for Brazilian Longitudinal Study of Adult Health (ELSA-Brasil, 2008-2010 with the aim of identifying eating patterns and their relationship to socio-demographic variables. Multiple correspondence and cluster analysis were applied. Four patterns were identified, with their respective frequencies: "traditional" (48%; "fruits and vegetables" (25%; "pastry shop" (24%; and "diet/light" (5% The "traditional" and "pastry shop" patterns were more frequent among men, younger individuals, and those with less schooling. "Fruits and vegetables" and "diet/light" were more frequent in women, older individuals, and those with more schooling. Our findings show the inclusion of new items in the "traditional" pattern and the appearance of the "low sugar/low fat" pattern among the eating habits of Brazilian workers, and signal socio-demographic and regional differences.

  15. Eating patterns in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil): an exploratory analysis.

    Science.gov (United States)

    Cardoso, Letícia de Oliveira; Carvalho, Marilia Sá; Cruz, Oswaldo Gonçalves; Melere, Cristiane; Luft, Vivian Cristine; Molina, Maria Del Carmen Bisi; Faria, Carolina Perim de; Benseñor, Isabela M; Matos, Sheila Maria Alvim; Fonseca, Maria de Jesus Mendes da; Griep, Rosane Harter; Chor, Dóra

    2016-01-01

    The food consumption of 15,071 public employees was analyzed in six Brazilian cities participating in the baseline for Brazilian Longitudinal Study of Adult Health (ELSA-Brasil, 2008-2010) with the aim of identifying eating patterns and their relationship to socio-demographic variables. Multiple correspondence and cluster analysis were applied. Four patterns were identified, with their respective frequencies: "traditional" (48%); "fruits and vegetables" (25%); "pastry shop" (24%); and "diet/light" (5%) The "traditional" and "pastry shop" patterns were more frequent among men, younger individuals, and those with less schooling. "Fruits and vegetables" and "diet/light" were more frequent in women, older individuals, and those with more schooling. Our findings show the inclusion of new items in the "traditional" pattern and the appearance of the "low sugar/low fat" pattern among the eating habits of Brazilian workers, and signal socio-demographic and regional differences.

  16. Nutrition Care after Discharge from Hospital: An Exploratory Analysis from the More-2-Eat Study

    Directory of Open Access Journals (Sweden)

    Celia Laur

    2018-01-01

    Full Text Available Many patients leave hospital in poor nutritional states, yet little is known about the post-discharge nutrition care in which patients are engaged. This study describes the nutrition-care activities 30-days post-discharge reported by patients and what covariates are associated with these activities. Quasi-randomly selected patients recruited from 5 medical units across Canada (n = 513 consented to 30-days post-discharge data collection with 48.5% (n = 249 completing the telephone interview. Use of nutrition care post-discharge was reported and bivariate analysis completed with relevant covariates for the two most frequently reported activities, following recommendations post-discharge or use of oral nutritional supplements (ONS. A total of 42% (n = 110 received nutrition recommendations at hospital discharge, with 65% (n = 71/110 of these participants following those recommendations; 26.5% (n = 66 were taking ONS after hospitalization. Participants who followed recommendations were more likely to report following a special diet (p = 0.002, different from before their hospitalization (p = 0.008, compared to those who received recommendations, but reported not following them. Patients taking ONS were more likely to be at nutrition risk (p < 0.0001, malnourished (p = 0.0006, taking ONS in hospital (p = 0.01, had a lower HGS (p = 0.0013; males only, and less likely to believe they were eating enough to meet their body’s needs (p = 0.005. This analysis provides new insights on nutrition-care post-discharge.

  17. Healthcare sector efficiency in Gujarat (India: an exploratory study using data envelopment analysis

    Directory of Open Access Journals (Sweden)

    Brijesh C. Purohit

    2016-06-01

    Full Text Available The importance of efficiency in resource utilization in healthcare sector has been recognized globally. In this paper we focus on efficiency of healthcare system at sub-state level (i.e., district level in India using Gujarat state and its district level data for 2012-13. In spite of being an economically advanced state, in terms of infant mortality rate (IMR the state is not the lowest. We explore the reasons for relative performance of different districts with data envelopment analysis (DEA. We used IMR as output variables. Using principal component analysis we tried a sub-set of variables, which had low correlations. Thus, four factor scores relating to medical officer, lady medical officer, Ayurveda, Yoga and Naturopathy, Unani, Siddha and Homoeopathy doctor, pharmacist, were used for DEA. We have focused on Charnes, Cooper, and Rhodes scores (or constant returns to scale technical efficiency score, and discussed efficiency rankings based on these. Thus, our results pertaining to district level health system efficiency in Gujarat State indicate that some of the districts have low efficiency in utilization of inputs like doctors, beds and workload per health institutions. There are also other districts, which need more of these inputs, which may enhance their output and efficiency. Thus, it is suggested that the efficiency in Valsad needs an improvement much more than other districts, whereas districts like Ahmadabad and Surat need more of both medical manpower and facilities. Even in case of Vadodara and Rajkot, the ranking in terms of most of medical manpower and facilities is low and thus these districts may also be benefitted by additional inputs. Hence, there is a mix of both inefficiency and inadequacy of inputs, which is reflected in our results.

  18. Exploratory factor analysis of the reintegration to normal living index in a stroke population.

    Science.gov (United States)

    Merz, Zachary C; Van Patten, Ryan; Mulhauser, Kyler; Fucetola, Robert

    2017-03-01

    The reintegration to normal living index (RNLI) is a global assessment of patient quality of life often utilized in stroke populations. Previous studies in various general disability samples have consistently reported a two-factor solution for the RNLI. Despite its common use with stroke patients, the RNLI has not been psychometrically evaluated in an exclusively stroke sample. This study is believed to represent the first factor analysis of the RNLI using a sample comprised exclusively of individuals who have survived cerebral infarct. The aim of this study is to evaluate the psychometric properties of the RNLI in assessing quality of life of stroke survivors. We retrospectively examined RNLI scores of 928 adults with strokes of varying severities as part of a multidisciplinary, interinstitutional collaboration across an academic medical center, acute care hospital, and rehabilitation center. We utilized a principal component factor analysis to evaluate the factor structure of the RNLI. Mean RNLI scores ±SD for the sample were 75.26 ± 19.85, ranging between 20 and 100. The Cronbach α was .94. A scree test for factor retention strongly suggested a single factor solution, explaining 64.50% of the total variance. Previous factor analyses on the RNLI utilizing general disability samples commonly report a two-factor solution. Our data support the presence of a single factor solution across the RNLI within a large sample comprised exclusively of stroke survivors. This suggests that the RNLI acts as more of a unitary measure of quality of life within a stroke sample relative to other disabled samples.

  19. Evidence assessing the diagnostic performance of medical smartphone apps: a systematic review and exploratory meta-analysis.

    Science.gov (United States)

    Buechi, Rahel; Faes, Livia; Bachmann, Lucas M; Thiel, Michael A; Bodmer, Nicolas S; Schmid, Martin K; Job, Oliver; Lienhard, Kenny R

    2017-12-14

    The number of mobile applications addressing health topics is increasing. Whether these apps underwent scientific evaluation is unclear. We comprehensively assessed papers investigating the diagnostic value of available diagnostic health applications using inbuilt smartphone sensors. Systematic Review-MEDLINE, Scopus, Web of Science inclusive Medical Informatics and Business Source Premier (by citation of reference) were searched from inception until 15 December 2016. Checking of reference lists of review articles and of included articles complemented electronic searches. We included all studies investigating a health application that used inbuilt sensors of a smartphone for diagnosis of disease. The methodological quality of 11 studies used in an exploratory meta-analysis was assessed with the Quality Assessment of Diagnostic Accuracy Studies 2 tool and the reporting quality with the 'STAndards for the Reporting of Diagnostic accuracy studies' (STARD) statement. Sensitivity and specificity of studies reporting two-by-two tables were calculated and summarised. We screened 3296 references for eligibility. Eleven studies, most of them assessing melanoma screening apps, reported 17 two-by-two tables. Quality assessment revealed high risk of bias in all studies. Included papers studied 1048 subjects (758 with the target conditions and 290 healthy volunteers). Overall, the summary estimate for sensitivity was 0.82 (95 % CI 0.56 to 0.94) and 0.89 (95 %CI 0.70 to 0.97) for specificity. The diagnostic evidence of available health apps on Apple's and Google's app stores is scarce. Consumers and healthcare professionals should be aware of this when using or recommending them. 42016033049. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  20. The hidden societal cost of antibiotic resistance per antibiotic prescribed in the United States: an exploratory analysis.

    Science.gov (United States)

    Michaelidis, Constantinos I; Fine, Michael J; Lin, Chyongchiou Jeng; Linder, Jeffrey A; Nowalk, Mary Patricia; Shields, Ryan K; Zimmerman, Richard K; Smith, Kenneth J

    2016-11-08

    Ambulatory antibiotic prescribing contributes to the development of antibiotic resistance and increases societal costs. Here, we estimate the hidden societal cost of antibiotic resistance per antibiotic prescribed in the United States. In an exploratory analysis, we used published data to develop point and range estimates for the hidden societal cost of antibiotic resistance (SCAR) attributable to each ambulatory antibiotic prescription in the United States. We developed four estimation methods that focused on the antibiotic-resistance attributable costs of hospitalization, second-line inpatient antibiotic use, second-line outpatient antibiotic use, and antibiotic stewardship, then summed the estimates across all methods. The total SCAR attributable to each ambulatory antibiotic prescription was estimated to be $13 (range: $3-$95). The greatest contributor to the total SCAR was the cost of hospitalization ($9; 69 % of the total SCAR). The costs of second-line inpatient antibiotic use ($1; 8 % of the total SCAR), second-line outpatient antibiotic use ($2; 15 % of the total SCAR) and antibiotic stewardship ($1; 8 %). This apperars to be an error.; of the total SCAR) were modest contributors to the total SCAR. Assuming an average antibiotic cost of $20, the total SCAR attributable to each ambulatory antibiotic prescription would increase antibiotic costs by 65 % (range: 15-475 %) if incorporated into antibiotic costs paid by patients or payers. Each ambulatory antibiotic prescription is associated with a hidden SCAR that substantially increases the cost of an antibiotic prescription in the United States. This finding raises concerns regarding the magnitude of misalignment between individual and societal antibiotic costs.

  1. An Exploratory Factor Analysis of the Scale Structure of the Patient Care Monitor Version 2.0.

    Science.gov (United States)

    Samsa, Gregory P; Wolf, Steven; LeBlanc, Thomas W; Abernethy, Amy P

    2016-04-01

    The Patient Care Monitor (PCM), version 2.0, is an electronic patient-reported outcomes instrument designed to be embedded into oncology practices. One key psychometric component of an instrument is its factor structure. To validate the factor structure of the PCM. The PCM was administered within various oncology clinics at our institution from 2006 to 2011 as part of standard of care, yielding a large (n = 5624) and diverse data set. An exploratory factor analysis was performed. The PCM performed well in terms of missing values and floor and ceiling effects. The three scales postulated by the PCM developers exhibited high internal consistency (Cronbach alpha 0.94-0.95); the six subscales exhibited good internal consistency (Cronbach alpha 0.80-0.95). A three-factor model approximated simple structure and was consistent with the constructs of emotional function, physical function, and physical symptoms suggested by the PCM developers. However, a six-factor model did not support the division of these three constructs into subscales of despair, distress, ambulation, impaired performance, treatment side effects, and general physical symptoms. Instead, we observed an emotional factor, a physical functioning factor, a factor including many of the treatment side effects, and three factors consisting of various clusters of physical symptoms. Although six subscales postulated by its developers perform reasonably, allocation of the PCM items to three constructs is more accurate and likely more consistent with how symptoms and concerns are conceptualized by patients. Copyright © 2016 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

  2. A book review of Spatial data analysis in ecology and agriculture using R

    Science.gov (United States)

    Spatial Data Analysis in Ecology and Agriculture Using R is a valuable resource to assist agricultural and ecological researchers with spatial data analyses using the R statistical software(www.r-project.org). Special emphasis is on spatial data sets; how-ever, the text also provides ample guidance ...

  3. Exploratory analysis of user-generated photos and indicators that influence their appeal

    Directory of Open Access Journals (Sweden)

    Urban Sedlar

    2014-07-01

    Full Text Available In this paper we analyze if simple indicators related to photo quality (brightness, sharpness, color palette and established content detection techniques (face detection can predict the success of photos in obtaining more “likes” from other users of photo-sharing social networks. This provides a unique look into the habits of users of such networks. The analysis was performed on 394.000 images downloaded from the social photo-sharing site Instagram, paired with a de-identified dataset of user liking activity, provided by a seller of a social-media mobile app. Two user groups were analyzed: all users in a two month period (N = 122.260 and a highly selective group (N = 3.982 of users that only like <10% of what they view. No correlation was found with any of the indicators using the whole (non-selective population, likely due to their bias towards earning virtual currency in exchange for liking. However, in selective group, small positive correlation was found between like ratio and image sharpness (r=0.09, p<0.0001 and small negative correlation between like ratio and the number of faces (r=-0.10, p<0.0001.

  4. HEALTH INSURANCE INFORMATION-SEEKING BEHAVIORS AMONG INTERNET USERS: AN EXPLORATORY ANALYSIS TO INFORM POLICIES.

    Science.gov (United States)

    Erlyana, Erlyana; Acosta-Deprez, Veronica; O'Lawrence, Henry; Sinay, Tony; Ramirez, Jeremy; Jacot, Emmanuel C; Shim, Kyuyoung

    2015-01-01

    The purpose of this study was to explore characteristics of Internet users who seek health insurance information online, as well as factors affecting their behaviors in seeking health insurance information. Secondary data analysis was conducted using data from the 2012 Pew Internet Health Tracking Survey. Of 2,305 Internet user adults, only 29% were seeking health insurance information online. Bivariate analyses were conducted to test differences in characteristics of those who seek health insurance information online and those who do not. A logistic regression model was used to determine significant predictors of health insurance information-seeking behavior online. Findings suggested that factors such as being a single parent, having a high school education or less, and being uninsured were significant and those individuals were less likely to seek health insurance information online. Being a family caregiver of an adult and those who bought private health insurance or were entitled to Medicare were more likely to seek health insurance information online than non-caregivers and the uninsured. The findings suggested the need to provide quality health insurance information online is critical for both the insured and uninsured population.

  5. Person-job fit: an exploratory cross-sectional analysis of hospitalists.

    Science.gov (United States)

    Hinami, Keiki; Whelan, Chad T; Miller, Joseph A; Wolosin, Robert J; Wetterneck, Tosha B

    2013-02-01

    Person-job fit is an organizational construct shown to impact the entry, performance, and retention of workers. Even as a growing number of physicians work under employed situations, little is known about how physicians select, develop, and perform in organizational settings. Our objective was to validate in the hospitalist physician workforce features of person-job fit observed in workers of other industries. The design was a secondary survey data analysis from a national stratified sample of practicing US hospitalists. The measures were person-job fit; likelihood of leaving practice or reducing workload; organizational climate; relationships with colleagues, staff, and patients; participation in suboptimal patient care activities. Responses to the Hospital Medicine Physician Worklife Survey by 816 (sample response rate 26%) practicing hospitalists were analyzed. Job attrition and reselection improved job fit among hospitalists entering the job market. Better job fit was achieved through hospitalists engaging a variety of personal skills and abilities in their jobs. Job fit increased with time together with socialization and internalization of organizational values. Hospitalists with higher job fit felt they performed better in their jobs. Features of person-job fit for hospitalists conformed to what have been observed in nonphysician workforces. Person-job fit may be a useful complementary survey measure related to job satisfaction but with a greater focus on function. Copyright © 2012 Society of Hospital Medicine.

  6. Approaches to automatic parameter fitting in a microscopy image segmentation pipeline: An exploratory parameter space analysis

    Directory of Open Access Journals (Sweden)

    Christian Held

    2013-01-01

    Full Text Available Introduction: Research and diagnosis in medicine and biology often require the assessment of a large amount of microscopy image data. Although on the one hand, digital pathology and new bioimaging technologies find their way into clinical practice and pharmaceutical research, some general methodological issues in automated image analysis are still open. Methods: In this study, we address the problem of fitting the parameters in a microscopy image segmentation pipeline. We propose to fit the parameters of the pipeline′s modules with optimization algorithms, such as, genetic algorithms or coordinate descents, and show how visual exploration of the parameter space can help to identify sub-optimal parameter settings that need to be avoided. Results: This is of significant help in the design of our automatic parameter fitting framework, which enables us to tune the pipeline for large sets of micrographs. Conclusion: The underlying parameter spaces pose a challenge for manual as well as automated parameter optimization, as the parameter spaces can show several local performance maxima. Hence, optimization strategies that are not able to jump out of local performance maxima, like the hill climbing algorithm, often result in a local maximum.

  7. Are country reputations for good and bad leadership on AIDS deserved? An exploratory quantitative analysis.

    Science.gov (United States)

    Nattrass, Nicoli

    2008-12-01

    Some countries (e.g. Brazil) have good reputations on AIDS policy, whereas others, (notably South Africa) have been criticized for inadequate leadership. Cross-country regression analysis reveals that these 'poster children' for AIDS leadership have indeed performed better or worse than expected given their economic and institutional constraints and the demographic and health challenges facing them. Regressions were run on HAART coverage (number on highly active antiretroviral therapy as percentage of total need) and MTCTP coverage (pregnant HIV+ women accessing mother-to-child-transmission prevention services as percentage of total need). Brazil, Cambodia, Thailand and Uganda (all of whom have established reputations for good leadership on AIDS performed consistently better than expected-as did Burkina-Faso, Suriname, Paraguay Costa Rica, Mali and Namibia. South Africa, which has the worst reputation for AIDS leadership, performed significantly below expectations-as did Uruguay and Trinidad and Tobago. The paper thus confirms much of the conventional wisdom on AIDS leadership at country level and suggests new areas for research.

  8. Offline constraints in online drug marketplaces: An exploratory analysis of a cryptomarket trade network.

    Science.gov (United States)

    Norbutas, Lukas

    2018-04-02

    Cryptomarkets, or illegal anonymizing online platforms that facilitate drug trade, have been analyzed in a rapidly growing body of research. Previous research has found that, despite increased risks, cryptomarket sellers are often willing to ship illegal drugs internationally. There is little to no information, however, about the extent to which uncertainty and risk related to geographic constraints shapes buyers' behavior and, in turn, the structure of the global online drug trade network. In this paper, we analyze the structure of a complete cryptomarket trade network with a focus on the role of geographic clustering of buyers and sellers. We use publicly available crawls of the cryptomarket Abraxas, encompassing market transactions between 463 sellers and 3542 buyers of drugs in 2015. We use descriptive social network analysis and Exponential Random Graph Models (ERGM) to analyze the structure of the trade network. The structure of the online drug trade network is primarily shaped by geographical boundaries. Buyers are more likely to buy from multiple sellers within a single country, and avoid buying from sellers in different countries, which leads to strong geographic clustering. The effect is especially strong between continents and weaker for countries within Europe. A small fraction of buyers (10%) account for more than a half of all drug purchases, while most buyers only buy once. Online drug trade networks might still be heavily shaped by offline (geographic) constraints, despite their ability to provide access for end-users to large international supply. Cryptomarkets might be more "localized" and less international than thought before. We discuss potential explanations for such geographical clustering and implications of the findings. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

  9. Knowledge Management and Politics at the Highest Level: An Exploratory Analysis

    Directory of Open Access Journals (Sweden)

    Eduardo TOMÉ

    2015-06-01

    Full Text Available This paper analyses Knowledge Management (KM as a political activity, made by the great political leaders of the world. We try to examine if at the macro political level KM is made, and how. The research is interesting because given that we live in a Knowledge Society, in the Information Era, it is more or less obvious that the political leaders should also do KM. However we don’t know of any previous study on KM and world leaders and this paper wants to be a first step to fill that gap. As a methodology we use literature review: given this one is a first preliminary study we use data we found online and in databases like EBSCO. We divide the analysis in two main parts: theoretical ideas, and application. In the theoretical part we aim at distinguishing KM as made by managers from KM made by politicians. The second part is itself divided in two segments: the past and the present times; in the second segment we illustrate our ideas with the example of President Barack Obama. We observe, rather surprisingly, how much it has been over-looked by scholars; KM always was and nowadays is pervasive in the activity of the world political leaders. Furthermore, the importance of KM made by world political leaders is so great that it should prompt the making of detailed studies in order to improve the world governance. The study has the limitation of relying on documents, insights and texts, and not on interviews. It should be followed by studies of a more qualitative and participative nature. We believe it would be very interesting to make such studies and that they would help improving the democracies in the 21st century and beyond.

  10. Autonomy support environment and autonomous motivation on nursing student academic performance: An exploratory analysis.

    Science.gov (United States)

    Bronson, Sevilla

    2016-09-01

    In the U.S., enrollment and graduation rates of baccalaureate nursing programs are slowly increasing. Rigorous program requirements can be overwhelming for students who may have difficulty adjusting to curriculum demands. Faculty who help students to adjust may also build a supportive learning environment that promotes autonomous motivation, improves engagement, and strengthens academic performance. Students may also experience well-being and autonomy when they feel supported and when their needs are met. The aim of this study was to investigate nursing students' autonomy support environments and autonomous motivation (measured as spirituality), and the influence on engagement and academic performance. A cross-sectional correlational design using a convenience sample of 150 nursing students in the last year of a baccalaureate nursing program was used. Participants were recruited from four universities in Florida and data collection occurred over three months. All participants were enrolled in the last year of their baccalaureate nursing program with an average Grade Point Average (GPA) of 3.36. The learning climate alone was moderately supportive of student motivation (M=70.60, SD=18.99). No significant relationship between the autonomy support environment and autonomous motivation (r=.034, p=.676) was found. Correlations and regression analysis of autonomous motivation and work engagement were significant (F (2, 147)=28.28, p=.000). Comparison of participant groups from each university independently revealed supportive learning environments. Strategies to promote autonomy must be developed and implemented as a means of ensuring a favorable learning environment. Future research may include the investigation of spirituality and autonomous motivation as two separate variables. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. The relationship between contextual work behaviours self-efficacy and work personality: an exploratory analysis.

    Science.gov (United States)

    Strauser, David R; O'Sullivan, Deirdre; Wong, Alex W K

    2010-01-01

    Work personality and contextual work behaviours have been identified as constructs that play critical roles in developing the foundation for effective vocational and career behaviour for persons with disabilities. For this study, we used a sample of 84 individuals with disabilities who were eligible to receive vocational rehabilitation services. Demographic variables and questions concerning work personality, contextual work behaviours self-efficacy, employment status and longest time employed were obtained and analysed to determine the relationship between contextual work behaviours self-efficacy, work personality and employment outcomes. The results indicate that work personality explained 24% (F = 2.73; p = 0.013) of the variance of contextual work behaviours self-efficacy with the subscale of Personal Presentation (β = 0.466) making a significant and unique contribution to CWB total score. Results of a correlation between the work personality profile scale and the contextual work behaviours self-efficacy scale revealed a significant and positive relationship. Levels of work personality and contextual work behaviours self-efficacy were unable to discriminate between employed and unemployed individuals. However, a post-hoc regression analysis did find that work personality and contextual work behaviours self-efficacy accounted for approximately 24% of the variance of longest time employed. The results of this study provide initial support for the relationship between work personality and contextual work behaviours self-efficacy. Overall, work personality appears to be an important construct related to individual's confidence to meet the contextual demand of the work environment and length of employment tenure.

  12. How do repeat suicide attempters differ from first timers? An exploratory record based analysis

    Directory of Open Access Journals (Sweden)

    Vikas Menon

    2016-01-01

    Full Text Available Background: Evidence indicates that repeat suicide attempters, as a group, may differ from 1st time attempters. The identification of repeat attempters is a powerful but underutilized clinical variable. Aims: In this research, we aimed to compare individuals with lifetime histories of multiple attempts with 1st time attempters to identify factors predictive of repeat attempts. Setting and Design: This was a retrospective record based study carried out at a teaching cum Tertiary Care Hospital in South India. Methods: Relevant data was extracted from the clinical records of 1st time attempters (n = 362 and repeat attempters (n = 61 presenting to a single Tertiary Care Center over a 4½ year period. They were compared on various sociodemographic and clinical parameters. The clinical measures included Presumptive Stressful Life Events Scale, Beck Hopelessness Scale, Coping Strategies Inventory – Short Form, and the Global Assessment of Functioning Scale. Statistical Analysis Used: First time attempters and repeaters were compared using appropriate inferential statistics. Logistic regression was used to identify independent predictors of repeat attempts. Results: The two groups did not significantly differ on sociodemographic characteristics. Repeat attempters were more likely to have given prior hints about their act (χ2 = 4.500, P = 0.034. In the final regression model, beck hopelessness score emerged as a significant predictor of repeat suicide attempts (odds ratio = 1.064, P = 0.020. Conclusion: Among suicide attempters presenting to the hospital, the presence of hopelessness is a predictor of repeat suicide attempts, independent of clinical depression. This highlights the importance of considering hopelessness in the assessment of suicidality with a view to minimize the risk of future attempts.

  13. DNA Damage and Repair Biomarkers in Cervical Cancer Patients Treated with Neoadjuvant Chemotherapy: An Exploratory Analysis.

    Directory of Open Access Journals (Sweden)

    Patrizia Vici

    Full Text Available Cervical cancer cells commonly harbour a defective G1/S checkpoint owing to the interaction of viral oncoproteins with p53 and retinoblastoma protein. The activation of the G2/M checkpoint may thus become essential for protecting cancer cells from genotoxic insults, such as chemotherapy. In 52 cervical cancer patients treated with neoadjuvant chemotherapy, we investigated whether the levels of phosphorylated Wee1 (pWee1, a key G2/M checkpoint kinase, and γ-H2AX, a marker of DNA double-strand breaks, discriminated between patients with a pathological complete response (pCR and those with residual disease. We also tested the association between pWee1 and phosphorylated Chk1 (pChk1, a kinase acting upstream Wee1 in the G2/M checkpoint pathway. pWee1, γ-H2AX and pChk1 were retrospectively assessed in diagnostic biopsies by immunohistochemistry. The degrees of pWee1 and pChk1 expression were defined using three different classification methods, i.e., staining intensity, Allred score, and a multiplicative score. γ-H2AX was analyzed both as continuous and categorical variable. Irrespective of the classification used, elevated levels of pWee1 and γ-H2AX were significantly associated with a lower rate of pCR. In univariate and multivariate analyses, pWee1 and γ-H2AX were both associated with reduced pCR. Internal validation conducted through a re-sampling without replacement procedure confirmed the robustness of the multivariate model. Finally, we found a significant association between pWee1 and pChk1. The message conveyed by the present analysis is that biomarkers of DNA damage and repair may predict the efficacy of neoadjuvant chemotherapy in cervical cancer. Further studies are warranted to prospectively validate these encouraging findings.

  14. Exploratory Analysis of Marketing and Non-marketing E-cigarette Themes on Twitter.

    Science.gov (United States)

    Han, Sifei; Kavuluru, Ramakanth

    2016-11-01

    Electronic cigarettes (e-cigs) have been gaining popularity and have emerged as a controversial tobacco product since their introduction in 2007 in the U.S. The smoke-free aspect of e-cigs renders them less harmful than conventional cigarettes and is one of the main reasons for their use by people who plan to quit smoking. The US food and drug administration (FDA) has introduced new regulations early May 2016 that went into effect on August 8, 2016. Given this important context, in this paper, we report results of a project to identify current themes in e-cig tweets in terms of semantic interpretations of topics generated with topic modeling. Given marketing/advertising tweets constitute almost half of all e-cig tweets, we first build a classifier that identifies marketing and non-marketing tweets based on a hand-built dataset of 1000 tweets. After applying the classifier to a dataset of over a million tweets (collected during 4/2015 - 6/2016), we conduct a preliminary content analysis and run topic models on the two sets of tweets separately after identifying the appropriate numbers of topics using topic coherence. We interpret the results of the topic modeling process by relating topics generated to specific e-cig themes. We also report on themes identified from e-cig tweets generated at particular places (such as schools and churches) for geo-tagged tweets found in our dataset using the GeoNames API. To our knowledge, this is the first effort that employs topic modeling to identify e-cig themes in general and in the context of geo-tagged tweets tied to specific places of interest.

  15. Learning Geospatial Analysis Skills with Consumer-Grade GPS Receivers and Low Cost Spatial Analysis Software

    Science.gov (United States)

    Linehan, Peter E.

    2006-01-01

    Spatial analysis technologies are increasingly important tools for all aspects of forest resource management. Field work previously accomplished with map, compass, and engineers' scale is now being augmented, or superseded, by the use of GPS and GIS. Professional-grade GPS receivers and commercial GIS software are preferred for their accuracy and…

  16. Analysis of Spatial Voting Patterns: An Approach in Political Socialization

    Science.gov (United States)

    Klimasewski, Ted

    1973-01-01

    Passage of the 26th Amendment gave young adults the right to vote. This study attempts to further student understanding of the electoral process by presenting a method for analyzing spatial voting patterns. The spatial emphasis adds another dimension to the temporal and behavioral-structural approaches in studying the American electoral system.…

  17. Analysis of students geometry skills viewed from spatial intelligence

    Science.gov (United States)

    Riastuti, Nova; Mardiyana, Pramudya, Ikrar

    2017-12-01

    Geometry is one of the difficult materials for students because students must have the ability to visualize, describe the picture, draw a figure, and know the kinds of figures. This study aimisto describe the students geometry skills in resolving geometry problems viewed from spatial intelligence. This research uses a descriptive qualitative method has aim to identify students geometry skills by 6 students in eight grade of Ngawi regency, Indonesia. The subjects were 2 students with high spatial intelligence, 2 students with medium spatial intelligence, and 2 students with low spatial intelligence. Datas were collected based on written test and interview. The result of this research showed that the students geometry skills viewed from spatial intelligence includes. The results of this study indicate that there was a correlation between students' spatial intelligence with geometric skills. Students had different geometric skills in each category of spatial intelligence, although there were similarities in some geometry skill indicators. Students with low spatial intelligence had less geometry skills, thus requiring special attention from teachers. Mathematics teachers are expected to provide more practice questions that reinforce students' geometry skills including visual skills, descriptive skills, drawing skills, logical skills, applied skills.

  18. Impact of prior therapies on everolimus activity: an exploratory analysis of RADIANT-4.

    Science.gov (United States)

    Buzzoni, Roberto; Carnaghi, Carlo; Strosberg, Jonathan; Fazio, Nicola; Singh, Simron; Herbst, Fabian; Ridolfi, Antonia; Pavel, Marianne E; Wolin, Edward M; Valle, Juan W; Oh, Do-Youn; Yao, James C; Pommier, Rodney

    2017-01-01

    Recently, everolimus was shown to improve median progression-free survival (PFS) by 7.1 months in patients with advanced, progressive, well-differentiated, nonfunctional neuroendocrine tumors (NET) of lung or gastrointestinal (GI) tract compared with placebo (HR, 0.48; 95% CI, 0.35-0.67; P <0.00001) in the Phase III, RADIANT-4 study. This post hoc analysis evaluates the impact of prior therapies (somatostatin analogs [SSA], chemotherapy, and radiotherapy) on everolimus activity. ClinicalTrials.gov identifier: NCT01524783. Patients were randomized (2:1) to everolimus 10 mg/day or placebo, both with best supportive care. Subgroups of patients who received prior SSA, chemotherapy, or radiotherapy (including peptide receptor radionuclide therapy) were analyzed and reported. A total of 302 patients were enrolled, of whom, 163 (54%) had any prior SSA use (mostly for tumor control), 77 (25%) received chemotherapy, and 63 (21%) were previously exposed to radiotherapy. Patients who received everolimus had longer median PFS compared with placebo, regardless of previous SSA (with SSA: 11.1 vs 4.5 months [HR, 0.56 {95% CI, 0.37-0.85}]; without SSA: 9.5 vs 3.7 months [0.57 {0.36-0.89}]), chemotherapy (with chemotherapy: 9.2 vs 2.1 months [0.35 {0.19-0.64}]; without chemotherapy: 11.2 vs 5.4 months [0.60 {0.42-0.86}]), or radiotherapy (with radiotherapy: 9.2 vs 3.0 months [0.47 {0.24-0.94}]; without radiotherapy: 11 vs 5.1 months [0.59 {0.42-0.83}]) exposure. The most frequent drug-related adverse events included stomatitis (59%-65%), fatigue (27%-35%), and diarrhea (24%-34%) among the subgroups. These results suggest that everolimus improves PFS in patients with advanced, progressive lung or GI NET, regardless of prior therapies. Safety findings were consistent with the known safety profile of everolimus in NET.

  19. Pilot Designed Aircraft Displays in General Aviation: An Exploratory Study and Analysis

    Science.gov (United States)

    Conaway, Cody R.

    From 2001-2011, the General Aviation (GA) fatal accident rate remained unchanged (Duquette & Dorr, 2014) with an overall stagnant accident rate between 2004 and 2013. The leading cause, loss of control in flight (NTSB, 2015b & 2015c) due to pilot inability to recognize approach to stall/spin conditions (NTSB, 2015b & 2016b). In 2013, there were 1,224 GA accidents in the U.S., accounting for 94% of all U.S. aviation accidents and 90% of all U.S. aviation fatalities that year (NTSB, 2015c). Aviation entails multiple challenges for pilots related to task management, procedural errors, perceptual distortions, and cognitive discrepancies. While machine errors in airplanes have continued to decrease over the years, human error still has not (NTSB, 2013). A preliminary analysis of a PC-based, Garmin G1000 flight deck was conducted with 3 professional pilots. Analyses revealed increased task load, opportunities for distraction, confusing perceptual ques, and hindered cognitive performance. Complex usage problems were deeply ingrained in the functionality of the system, forcing pilots to use fallible work arounds, add unnecessary steps, and memorize knob turns or button pushes. Modern computing now has the potential to free GA cockpit designs from knobs, soft keys, or limited display options. Dynamic digital displays might include changes in instrumentation or menu structuring depending on the phase of flight. Airspeed indicators could increase in size to become more salient during landing, simultaneously highlighting pitch angle on Attitude Indicators and automatically decluttering unnecessary information for landing. Likewise, Angle-of-Attack indicators demonstrate a great safety and performance advantage for pilots (Duquette & Dorr, 2014; NTSB, 2015b & 2016b), an instrument typically found in military platforms and now the Icon A5, light-sport aircraft (Icon, 2016). How does the design of pilots' environment---the cockpit---further influence their efficiency and

  20. A Spatial and Temporal Analysis of Upward Triggered Lightning

    Science.gov (United States)

    Ballweber, A. J.

    2013-12-01

    Alana Ballweber, John H. Helsdon Jr., and Tom A. Warner South Dakota School of Mines and Technology Ten tall communication towers lining the ridge in Rapid City, South Dakota provide a unique opportunity to study the phenomenon of lightning-triggered upward lightning. The Upward Lightning Triggering Study (UPLIGHTS), seeks to determine if upward positive leaders are triggered from these towers by: (1) the approach of horizontally propagating negative stepped leaders associated with either intracloud development or following a positive cloud-to-ground (+CG) return stroke, and/or (2) a +CG return stroke as it propagates through a previously formed leader network near the towers. As part of the UPLIGHTS research, two separate lightning mapping devices were used to aid in a 3D re-creation of the triggering flash, a 3D digital interferometer and a Lightning Mapping Array. Through the use of these two devices, we present findings founded on the analysis of data collected from these assets during the 2013 storm season. Specifically, we quantify the spatial and temporal relationship of the triggering flash leader activity relative to the tall objects when upward leaders develop and when upward leaders fail to develop. Furthermore, the lightning mapping devices were correlated with high-speed optical and electrical field observations to provide a further insight as to why certain flashes trigger upward lightning from tall structures and others do not.

  1. The Association between Foster Care and Substance Abuse Risk Factors and Treatment Outcomes: An Exploratory Secondary Analysis

    Science.gov (United States)

    Blome, Wendy Whiting; Shields, Joseph; Verdieck, Mary Jeanne

    2009-01-01

    The child welfare and substance abuse systems are integrally linked through the children and families they both serve. There is a dearth of knowledge, however, on how children who have experienced foster care fare when they are treated for substance abuse issues as adults. This article presents an exploratory study using the Alcohol and Drug…

  2. Investigation of Arctic and Antarctic spatial and depth patterns of sea water in CTD profiles using chemometric data analysis

    DEFF Research Database (Denmark)

    Kotwa, Ewelina Katarzyna; Lacorte, Silvia; Duarte, Carlos

    2014-01-01

    In this paper we examine 2- and 3-way chemometric methods for analysis of Arctic and Antarctic water samples. Standard CTD (conductivity–temperature–depth) sensor devices were used during two oceanographic expeditions (July 2007 in the Arctic; February 2009 in the Antarctic) covering a total of 1...... properties of the water samples; and 4) we confirm the ability to predict fluorescence values from physical measurements when the 3-way data structure is used in N-way PLS regression.......In this paper we examine 2- and 3-way chemometric methods for analysis of Arctic and Antarctic water samples. Standard CTD (conductivity–temperature–depth) sensor devices were used during two oceanographic expeditions (July 2007 in the Arctic; February 2009 in the Antarctic) covering a total of 174...... locations. The output from these devices can be arranged in a 3-way data structure (according to sea water depth, measured variables, and geographical location). We used and compared 2- and 3-way statistical tools including PCA, PARAFAC, PLS, and N-PLS for exploratory analysis, spatial patterns discovery...

  3. Impact of prior therapies on everolimus activity: an exploratory analysis of RADIANT-4

    Directory of Open Access Journals (Sweden)

    Buzzoni R

    2017-10-01

    Full Text Available Roberto Buzzoni,1 Carlo Carnaghi,2 Jonathan Strosberg,3 Nicola Fazio,4 Simron Singh,5 Fabian Herbst,6 Antonia Ridolfi,7 Marianne E Pavel,8 Edward M Wolin,9 Juan W Valle,10 Do-Youn Oh,11 James C Yao,12 Rodney Pommier13 1IRCCS Foundation, National Institute of Tumors, Milan, Italy; 2Humanitas Clinical and Research Center, Rozzano, Italy; 3Moffitt Cancer Center, Tampa, FL, USA; 4European Institute of Oncology, Milan, Italy; 5Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 6Novartis AG, Basel, Switzerland; 7Novartis Pharma S.A.S., Rueil-Malmaison, France; 8Medizinische Klinik 1, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany; 9Montefiore Einstein Center for Cancer Care, Bronx, NY, USA; 10Institute of Cancer Sciences, University of Manchester, The Christie Hospital, Manchester, UK; 11Seoul National University Hospital, Seoul, Republic of Korea; 12University of Texas M.D. Anderson Cancer Center, Houston, TX, USA; 13Oregon Health & Science University, Portland, OR, USA Background: Recently, everolimus was shown to improve median progression-free survival (PFS by 7.1 months in patients with advanced, progressive, well-differentiated, nonfunctional neuroendocrine tumors (NET of lung or gastrointestinal (GI tract compared with placebo (HR, 0.48; 95% CI, 0.35–0.67; P<0.00001 in the Phase III, RADIANT-4 study. This post hoc analysis evaluates the impact of prior therapies (somatostatin analogs [SSA], chemotherapy, and radiotherapy on everolimus activity. Trial registration: ClinicalTrials.gov identifier: NCT01524783. Patients and methods: Patients were randomized (2:1 to everolimus 10 mg/day or placebo, both with best supportive care. Subgroups of patients who received prior SSA, chemotherapy, or radiotherapy (including peptide receptor radionuclide therapy were analyzed and reported. Results: A total of 302 patients were enrolled, of whom, 163 (54% had any prior SSA use (mostly for tumor control, 77 (25% received

  4. Exploratory meta-analysis on lisdexamfetamine versus placebo in adult ADHD

    Directory of Open Access Journals (Sweden)

    Maneeton N

    2014-10-01

    risks (RRs, and weighted mean differences or standardized mean differences (SMDs with 95% confidence intervals (CIs.Results: A total of 806 final study or safety participants were included. The dosage of lisdexamfetamine was 30 to 70 mg/day. The pooled mean scores of mean change and mean end point scores between LDX- and placebo-treated groups also had a significant difference (SMD [95% CI] of -0.97 [-1.15, -0.78], I2=18%. The pooled response rates for adult ADHD between the two groups had a significant difference (RR [95% CI] of 1.99 [1.50, 2.63], I2=0%. Based on the Behavior Rating Inventory of Executive Function – Adult version (BRIEF-A, the pooled end point mean scores for the Global Executive Composite (GEC for the LDX-treated groups was greater than that of placebo-treated groups (MD [95% CI] of –9.20 [-14.11, -4.29], I2=34%. The pooled overall discontinuation rates between the two groups had no significant difference (RR [95% CI] of 0.82 [0.59, 1.14], I2=0%. Similarly, the pooled discontinuation rates due to adverse events between the two groups was not significantly different (RR [95% CI] of 1.77 [0.71, 4.40], I2=0%.Conclusion: The number of included studies was limited (five RCTs, but based on this meta-analysis, LDX is efficacious and well tolerated in the treatment of adult ADHD. Additionally, it also improved the executive function deficits in this population. However, its acceptability is no higher than placebo. These findings should be carefully interpreted and considered as preliminary outcomes. To confirm these results, further studies are warranted. LDX is a viable alternative psychostimulant for adult ADHD. Keywords: lisdexamfetamine, placebo, systematic review, adult ADHD, acceptability, tolerability

  5. Spatial analysis of colorectal cancer cases in Kuala Lumpur.

    Science.gov (United States)

    Shah, Shamsul Azhar; Neoh, Hui-Min; Rahim, Syed Sharizman Syed Abdul; Azhar, Zahir Izuan; Hassan, Mohd Rohaizat; Safian, Nazarudin; Jamal, Rahman

    2014-01-01

    In Malaysia, data from the Malaysian Health Ministry showed colorectal cancer (CRC) to be the second most common type of cancer in 2007-2009, after breast cancer. The same was apparent after looking at males and females cases separately. In the present study, the Geographic Information System (GIS) was employed to describe the distribution of CRC cases in Kuala Lumpur (KL), Malaysia, according to socio-demographic factors (age, gender, ethnicity and district). This retrospective review concerned data for patients diagnosed with colorectal cancer in the years 1995 to 2011 collected from the Wilayah Persekutuan Health Office, taken from the cancer notification form (NCR-2), and patient medical records from the Surgical Department, Universiti Kebangsaan Malaysia Medical Centre (UKMMC). A total of 146 cases were analyzed. All the data collected were analysed using ArcGIS version 10.0 and SPSS version 19.0. Patients aged 60 to 69 years accounted for the highest proportion of cases (34.2%) and males slightly predominated 76 (52.1%), Chinese had the highest number of registered cases at 108 (74.0%) and staging revealed most cases in the 3rd and 4th stages. Kernel density analysis showed more cases are concentrated up in the northern area of Petaling and Kuala Lumpur subdistricts. Spatial global pattern analysis by average nearest neighbour resulted in nearest neighbour ratio of 0.75, with Z-score of -5.59, p value of population and improvement of healthcare facilities to provide better treatment for CRC patients.

  6. Situated student learning and spatial informational analysis for environmental problems

    Science.gov (United States)

    Olsen, Timothy Paul

    Ninth and tenth grade high school Biology student research teams used spatial information analysis tools to site a prairie restoration plot on a 55 acre campus during a four-week environment unit. Students made use of innovative technological practices by applying geographic information systems (GIS) approaches to solving environmental and land use problems. Student learning was facilitated by starting with the students' initial conceptions of computing, local landscape and biological environment, and then by guiding them through a problem-based science project process. The project curriculum was framed by the perspective of legitimate peripheral participation (Lave & Wenger, 1991) where students were provided with learning opportunities designed to allow them to act like GIS practitioners. Sociocultural lenses for learning were employed to create accounts of human mental processes that recognize the essential relationship between these processes and their cultural, historical, and institutional settings (Jacob, 1997; Wertsch, 1991). This research investigated how student groups' meaning-making actions were mediated by GIS tools on the periphery of a scientific community of practice. Research observations focused on supporting interpretations of learners' socially constructed actions and the iterative building of assertions from multiple sources. These included the artifacts students produced, the tools they used, the cultural contexts that constrained their activity, and how people begin to adopt ways of speaking (speech genres) of the referent community to negotiate meanings and roles. Students gathered field observations and interpreted attributes of landscape entities from the GIS data to advocate for an environmental decision. However, even while gaining proficiencies with GIS tools, most students did not begin to appropriate roles from the GIS community of practice. Students continued to negotiate their project actions simply as school exercises motivated by

  7. Analysis of the spatial distribution between successive earthquakes

    International Nuclear Information System (INIS)

    Davidsen, Joern; Paczuski, Maya

    2005-01-01

    Spatial distances between subsequent earthquakes in southern California exhibit scale-free statistics, with a critical exponent δ≅0.6, as well as finite size scaling. The statistics are independent of the threshold magnitude as long as the catalog is complete, but depend strongly on the temporal ordering of events, rather than the geometry of the spatial epicenter distribution. Nevertheless, the spatial distance and waiting time between subsequent earthquakes are uncorrelated with each other. These observations contradict the theory of aftershock zone scaling with main shock magnitude

  8. GEMAS: Spatial pattern analysis of Ni by using digital image processing techniques on European agricultural soil data

    Science.gov (United States)

    Jordan, Gyozo; Petrik, Attila; De Vivo, Benedetto; Albanese, Stefano; Demetriades, Alecos; Sadeghi, Martiya

    2017-04-01

    Several studies have investigated the spatial distribution of chemical elements in topsoil (0-20 cm) within the framework of the EuroGeoSurveys Geochemistry Expert Group's 'Geochemical Mapping of Agricultural and Grazing Land Soil' project . Most of these studies used geostatistical analyses and interpolated concentration maps, Exploratory and Compositional Data and Analysis to identify anomalous patterns. The objective of our investigation is to demonstrate the use of digital image processing techniques for reproducible spatial pattern recognition and quantitative spatial feature characterisation. A single element (Ni) concentration in agricultural topsoil is used to perform the detailed spatial analysis, and to relate these features to possible underlying processes. In this study, simple univariate statistical methods were implemented first, and Tukey's inner-fence criterion was used to delineate statistical outliers. The linear and triangular irregular network (TIN) interpolation was used on the outlier-free Ni data points, which was resampled to a 10*10 km grid. Successive moving average smoothing was applied to generalise the TIN model and to suppress small- and at the same time enhance significant large-scale features of Nickel concentration spatial distribution patterns in European topsoil. The TIN map smoothed with a moving average filter revealed the spatial trends and patterns without losing much detail, and it was used as the input into digital image processing, such as local maxima and minima determination, digital cross sections, gradient magnitude and gradient direction calculation, second derivative profile curvature calculation, edge detection, local variability assessment, lineament density and directional variogram analyses. The detailed image processing analysis revealed several NE-SW, E-W and NW-SE oriented elongated features, which coincide with different spatial parameter classes and alignment with local maxima and minima. The NE-SW oriented

  9. Practical likelihood analysis for spatial generalized linear mixed models

    DEFF Research Database (Denmark)

    Bonat, W. H.; Ribeiro, Paulo Justiniano

    2016-01-01

    , respectively, examples of binomial and count datasets modeled by spatial generalized linear mixed models. Our results show that the Laplace approximation provides similar estimates to Markov Chain Monte Carlo likelihood, Monte Carlo expectation maximization, and modified Laplace approximation. Some advantages...

  10. Spatial Analysis of Case-Mix and Dialysis Modality Associations.

    Science.gov (United States)

    Phirtskhalaishvili, Tamar; Bayer, Florian; Edet, Stephane; Bongiovanni, Isabelle; Hogan, Julien; Couchoud, Cécile

    2016-01-01

    ♦ Health-care systems must attempt to provide appropriate, high-quality, and economically sustainable care that meets the needs and choices of patients with end-stage renal disease (ESRD). France offers 9 different modalities of dialysis, each characterized by dialysis technique, the extent of professional assistance, and the treatment site. The aim of this study was 1) to describe the various dialysis modalities in France and the patient characteristics associated with each of them, and 2) to analyze their regional patterns to identify possible unexpected associations between case-mixes and dialysis modalities. ♦ The clinical characteristics of the 37,421 adult patients treated by dialysis were described according to their treatment modality. Agglomerative hierarchical cluster analysis was used to aggregate the regions into clusters according to their use of these modalities and the characteristics of their patients. ♦ The gradient of patient characteristics was similar from home hemodialyis (HD) to in-center HD and from non-assisted automated peritoneal dialysis (APD) to assisted continuous ambulatory peritoneal dialysis (CAPD). Analyzing their spatial distribution, we found differences in the patient case-mix on dialysis across regions but also differences in the health-care provided for them. The classification of the regions into 6 different clusters allowed us to detect some unexpected associations between case-mixes and treatment modalities. ♦ The 9 modalities of treatment available make it theoretically possible to adapt treatment to patients' clinical characteristics and abilities. However, although we found an overall appropriate association of dialysis modalities to the case-mix, major inter-region heterogeneity and the low rate of peritoneal dialysis (PD) and home HD suggest that factors besides patients' clinical conditions impact the choice of dialysis modality. The French organization should now be evaluated in terms of patients' quality of

  11. Exploratory analysis of textual data from the Mother and Child Handbook using a text mining method (II): Monthly changes in the words recorded by mothers.

    Science.gov (United States)

    Tagawa, Miki; Matsuda, Yoshio; Manaka, Tomoko; Kobayashi, Makiko; Ohwada, Michitaka; Matsubara, Shigeki

    2017-01-01

    The aim of the study was to examine the possibility of converting subjective textual data written in the free column space of the Mother and Child Handbook (MCH) into objective information using text mining and to compare any monthly changes in the words written by the mothers. Pregnant women without complications (n = 60) were divided into two groups according to State-Trait Anxiety Inventory grade: low trait anxiety (group I, n = 39) and high trait anxiety (group II, n = 21). Exploratory analysis of the textual data from the MCH was conducted by text mining using the Word Miner software program. Using 1203 structural elements extracted after processing, a comparison of monthly changes in the words used in the mothers' comments was made between the two groups. The data was mainly analyzed by a correspondence analysis. The structural elements in groups I and II were divided into seven and six clusters, respectively, by cluster analysis. Correspondence analysis revealed clear monthly changes in the words used in the mothers' comments as the pregnancy progressed in group I, whereas the association was not clear in group II. The text mining method was useful for exploratory analysis of the textual data obtained from pregnant women, and the monthly change in the words used in the mothers' comments as pregnancy progressed differed according to their degree of unease. © 2016 Japan Society of Obstetrics and Gynecology.

  12. Spatial-data sharing: Applying social-network analysis to study individual and collective behaviour

    NARCIS (Netherlands)

    Omran, E.S.E.; Etten, van J.

    2007-01-01

    Spatial-Data Sharing (SDS) is a crucial aspect of spatial-data infrastructures. This paper introduces Social-Network Analysis to research on SDS. By mapping out relationships among social actors using Social-Network Analysis, the collective properties of SDS in organizations can be investigated.

  13. Spatial Dependence and Heterogeneity in Bayesian Factor Analysis: A Cross-National Investigation of Schwartz Values

    Science.gov (United States)

    Stakhovych, Stanislav; Bijmolt, Tammo H. A.; Wedel, Michel

    2012-01-01

    In this article, we present a Bayesian spatial factor analysis model. We extend previous work on confirmatory factor analysis by including geographically distributed latent variables and accounting for heterogeneity and spatial autocorrelation. The simulation study shows excellent recovery of the model parameters and demonstrates the consequences…

  14. Comparative analysis of time efficiency and spatial resolution between different EIT reconstruction algorithms

    International Nuclear Information System (INIS)

    Kacarska, Marija; Loskovska, Suzana

    2002-01-01

    In this paper comparative analysis between different EIT algorithms is presented. Analysis is made for spatial and temporal resolution of obtained images by several different algorithms. Discussions consider spatial resolution dependent on data acquisition method, too. Obtained results show that conventional applied-current EIT is more powerful compared to induced-current EIT. (Author)

  15. Cultural and Socio Economic Experiences of Female Entrepreneurs in Brazil and the United States: An Exploratorial and Empirical Analysis

    OpenAIRE

    Neila Holland

    2014-01-01

    Over the last twenty years female entrepreneurs have been increasing in numbers in economies of developing and developed nations across the world. But although female entrepreneurship participation rates have increased worldwide, it appears that economic and socio cultural patterns still prescribe whether a female can become or want to become an entrepreneur in her society. This qualitative exploratory study investigates the phenomenon of female entrepreneurship comparing female entrepreneurs...

  16. Clients' narratives in psychotherapy and therapist's theoretical orientation : an exploratory analysis of Gloria's narratives with Rogers, Ellis and Perls

    OpenAIRE

    Moreira, Paulo; Gonçalves, Óscar F.; Matias, Carla

    2011-01-01

    The therapist’s theoretical orientation has been shown to impact the psychotherapy process. However, less is known about the extent to which the therapist’s orientation may impact clients’ narratives. This exploratory study analysed clients’ narrative production in psychoptherapy, when interacting with different therapists. The data consisted of transcripts of Shostrom’s videotaped therapy sessions between the client Gloria and the therapists Carl Rogers, Fritz Perls and Alb...

  17. Exploratory factor analysis and reliability of the Primary Health Care Engagement (PHCE) Scale in rural and remote nurses: findings from a national survey.

    Science.gov (United States)

    Kosteniuk, Julie G; Stewart, Norma J; Karunanayake, Chandima P; Wilson, Erin C; Penz, Kelly L; Kulig, Judith C; Kilpatrick, Kelley; Martin-Misener, Ruth; Morgan, Debra G; MacLeod, Martha L P

    2017-11-01

    Aim The study purpose was to provide evidence of validity for the Primary Health Care Engagement (PHCE) Scale, based on exploratory factor analysis and reliability findings from a large national survey of regulated nurses residing and working in rural and remote Canadian communities. There are currently no published provider-level instruments to adequately assess delivery of community-based primary health care, relevant to ongoing primary health care (PHC) reform strategies across Canada and elsewhere. The PHCE Scale reflects a contemporary approach that emphasizes community-oriented and community-based elements of PHC delivery. Data from the pan-Canadian Nursing Practice in Rural and Remote Canada II (RRNII) survey were used to conduct an exploratory factor analysis and evaluate the internal consistency reliability of the final PHCE Scale. Findings The RRNII survey sample included 1587 registered nurses, nurse practitioners, licensed practical nurses, and registered psychiatric nurses residing and working in rural and remote Canada. Exploratory factor analysis identified an eight-factor structure across 28 items overall, and good internal consistency reliability was indicated by an α estimate of 0.89 for the final scale. The final 28-item PHCE Scale includes three of four elements in a contemporary approach to PHC (accessibility/availability, community participation, and intersectoral team) and most community-oriented/based elements of PHC (interdisciplinary collaboration, person-centred, continuity, population orientation, and quality improvement). We recommend additional psychometric testing in a range of health care providers and settings, as the PHCE Scale shows promise as a tool for health care planners and researchers to test interventions and track progress in primary health care reform.

  18. Neighborhood social capital and crime victimization: comparison of spatial regression analysis and hierarchical regression analysis.

    Science.gov (United States)

    Takagi, Daisuke; Ikeda, Ken'ichi; Kawachi, Ichiro

    2012-11-01

    Crime is an important determinant of public health outcomes, including quality of life, mental well-being, and health behavior. A body of research has documented the association between community social capital and crime victimization. The association between social capital and crime victimization has been examined at multiple levels of spatial aggregation, ranging from entire countries, to states, metropolitan areas, counties, and neighborhoods. In multilevel analysis, the spatial boundaries at level 2 are most often drawn from administrative boundaries (e.g., Census tracts in the U.S.). One problem with adopting administrative definitions of neighborhoods is that it ignores spatial spillover. We conducted a study of social capital and crime victimization in one ward of Tokyo city, using a spatial Durbin model with an inverse-distance weighting matrix that assigned each respondent a unique level of "exposure" to social capital based on all other residents' perceptions. The study is based on a postal questionnaire sent to 20-69 years old residents of Arakawa Ward, Tokyo. The response rate was 43.7%. We examined the contextual influence of generalized trust, perceptions of reciprocity, two types of social network variables, as well as two principal components of social capital (constructed from the above four variables). Our outcome measure was self-reported crime victimization in the last five years. In the spatial Durbin model, we found that neighborhood generalized trust, reciprocity, supportive networks and two principal components of social capital were each inversely associated with crime victimization. By contrast, a multilevel regression performed with the same data (using administrative neighborhood boundaries) found generally null associations between neighborhood social capital and crime. Spatial regression methods may be more appropriate for investigating the contextual influence of social capital in homogeneous cultural settings such as Japan. Copyright

  19. Spatial patterns of rural poverty: an exploratory analysis in the São Francisco River Basin, Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo de Oliveira Torres

    2011-07-01

    Full Text Available A caracterização e a análise da distribuição espacial da pobreza podem ser úteis na apli-cação de programas voltados para a redução de pobreza já que possibilitam a identificação de áreas onde a incidência é maior e cuja ex-tensão muitas vezes ultrapassa as linhas ter-ritoriais oficiais. Nesse contexto, este artigo usa os mais recentes dados sobre pobreza rural municipal no Brasil para identificar os padrões espaciais de pobreza rural na Bacia do Rio São Francisco (BRSF. Indicadores de autocorrelação espacial I de Moran são gera-dos e usados para a construção de um mapa de clusters de pobreza rural. Os resultados indicam que a pobreza rural é espacialmen-te autocorrelacionada em algumas áreas da BRSF, nas quais municípios mais (menos pobres tendem a se localizar perto de municí-pios mais (menos pobres. Mais importante, talvez, os resultados sugerem a necessidade de se usar metodologias de análise que consi-derem explicitamente a localização como um fator explanatório da pobreza rural na bacia, como, por exemplo, econometria espacial.

  20. Exploratory of society

    Science.gov (United States)

    Cederman, L.-E.; Conte, R.; Helbing, D.; Nowak, A.; Schweitzer, F.; Vespignani, A.

    2012-11-01

    A huge flow of quantitative social, demographic and behavioral data is becoming available that traces the activities and interactions of individuals, social patterns, transportation infrastructures and travel fluxes. This has caused, together with innovative computational techniques and methods for modeling social actions in hybrid (natural and artificial) societies, a qualitative change in the ways we model socio-technical systems. For the first time, society can be studied in a comprehensive fashion that addresses social and behavioral complexity. In other words we are in the position to envision the development of large data and computational cyber infrastructure defining an exploratory of society that provides quantitative anticipatory, explanatory and scenario analysis capabilities ranging from emerging infectious disease to conflict and crime surges. The goal of the exploratory of society is to provide the basic infrastructure embedding the framework of tools and knowledge needed for the design of forecast/anticipatory/crisis management approaches to socio technical systems, supporting future decision making procedures by accelerating the scientific cycle that goes from data generation to predictions.

  1. [NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 2:] Technical communications in aeronautics: Results of an exploratory study. An analysis of managers' and nonmanagers' responses

    Science.gov (United States)

    Pinelli, Thomas E.; Glassman, Myron; Barclay, Rebecca O.; Oliu, Walter E.

    1989-01-01

    Data collected from an exploratory study concerned with the technical communications practices of aerospace engineers and scientists were analyzed to test the primary assumption that aerospace managers and nonmanagers have different technical communications practices. Five assumptions were established for the analysis. Aerospace managers and nonmanagers were found to have different technical communications practices for three of the five assumptions tested. Although aerospace managers and nonmanagers were found to have different technical communications practices, the evidence was neither conclusive nor compelling that the presumption of difference in practices could be attributed to the duties performed by aerospace managers and nonmanagers.

  2. [NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 3:] Technical communications in aeronautics: Results of an exploratory study. An analysis of profit managers' and nonprofit managers' responses

    Science.gov (United States)

    Pinelli, Thomas E.; Glassman, Myron; Barclay, Rebecca O.; Oliu, Walter E.

    1989-01-01

    Data collected from an exploratory study concerned with the technical communications practices of aerospace engineers and scientists were analyzed to test the primary assumption that profit and nonprofit managers in the aerospace community have different technical communications practices. Five assumptions were established for the analysis. Profit and nonprofit managers in the aerospace community were found to have different technical communications practices for one of the five assumptions tested. It was, therefore, concluded that profit and nonprofit managers in the aerospace community do not have different technical communications practices.

  3. Interaction of Regional Labour Markets in Russia: Spatial Econometric Analysis

    Directory of Open Access Journals (Sweden)

    Elena Vyacheslavovna Semerikova

    2016-09-01

    Full Text Available With the help of spatial regression models and classical models of panel data the study identifies and assesses the various factors’ influence on the unemployment rate in Russian regions from 2005 to 2010. Using the spatial autoregressive lag model the authors revealed that the change (increase or decrease in the level of unemployment in one region leads to its changes in other regions. The use of spatial regression models allowed the researchers to identify the effect of higher education on the unemployment rate in the region: the higher share of the employed with higher education corresponds to the lower unemployment rate. This can’t be revealed with the help of classical models of panel data. In addition, some regional characteristics have nonlinear functional dependence of unemployment rate, which requires the algorithm modification for finding direct, indirect and total effects and their confidence intervals using the Monte Carlo approach

  4. Alignment error analysis of detector array for spatial heterodyne spectrometer.

    Science.gov (United States)

    Jin, Wei; Chen, Di-Hu; Li, Zhi-Wei; Luo, Hai-Yan; Hong, Jin

    2017-12-10

    Spatial heterodyne spectroscopy (SHS) is a new spatial interference spectroscopy which can achieve high spectral resolution. The alignment error of the detector array can lead to a significant influence with the spectral resolution of a SHS system. Theoretical models for analyzing the alignment errors which are divided into three kinds are presented in this paper. Based on these models, the tolerance angle of these errors has been given, respectively. The result of simulation experiments shows that when the angle of slope error, tilt error, and rotation error are less than 1.21°, 1.21°, 0.066° respectively, the alignment reaches an acceptable level.

  5. Carbon Sequestration in Colorado's Lands: A Spatial and Policy Analysis

    Science.gov (United States)

    Brandt, N.; Brazeau, A.; Browning, K.; Meier, R.

    2017-12-01

    Managing landscapes to enhance terrestrial carbon sequestration has significant potential to mitigate climate change. While a previous carbon baseline assessment in Colorado has been published (Conant et al, 2007), our study pulls from the existing literature to conduct an updated baseline assessment of carbon stocks and a unique review of carbon policies in Colorado. Through a multi-level spatial analysis based in GIS and informed by a literature review, we established a carbon stock baseline and ran four land use and carbon stock projection scenarios using Monte Carlo simulations. We identified 11 key policy recommendations for improving Colorado's carbon stocks, and evaluated each using Bardach's policy matrix approach (Bardach, 2012). We utilized a series of case studies to support our policy recommendations. We found that Colorado's lands have a carbon stock of 3,334 MMT CO2eq, with Forests and Woodlands holding the largest stocks, at 1,490 and 774 MMT CO2eq respectively. Avoided conversion of all Grasslands, Forests, and Wetlands in Colorado projected over 40 years would increase carbon stocks by 32 MMT CO2eq, 1,053 MMT CO2eq, and 36 MMT CO2eq, respectively. Over the 40-year study period, Forests and Woodlands areas are projected to shrink while Shrublands and Developed areas are projected to grow. Those projections suggest sizable increases in area of future wildfires and development in Colorado. We found that numerous policy opportunities to sequester carbon exist at different jurisdictional levels and across land cover types. The largest opportunities were found in state-level policies and policies impacting Forests, Grasslands, and Wetlands. The passage of statewide emission reduction legislation has the highest potential to impact carbon sequestration, although political and administrative feasibility of this option are relatively low. This study contributes to the broader field of carbon sequestration literature by examining the nexus of carbon stocks

  6. Spatially Explicit Analysis of Water Footprints in the UK

    Directory of Open Access Journals (Sweden)

    John Barrett

    2010-12-01

    Full Text Available The Water Footprint, as an indicator of water consumption has become increasingly popular for analyzing environmental issues associated with the use of water resources in the global supply chain of consumer goods. This is particularly relevant for countries like the UK, which increasingly rely on products produced elsewhere in the world and thus impose pressures on foreign water resources. Existing studies calculating water footprints are mostly based on process analysis, and results are mainly available at the national level. The current paper assesses the domestic and foreign water requirements for UK final consumption by applying an environmentally extended multi-regional input-output model in combination with geo-demographic consumer segmentation data. This approach allows us to calculate water footprints (both direct and indirect for different products as well as different geographies within the UK. We distinguished between production and consumption footprints where the former is the total water consumed from the UK domestic water resources by the production activities in the UK and the latter is the total water consumed from both domestic and global water resources to satisfy the UK domestic final consumption. The results show that the production water footprint is 439 m3/cap/year, 85% of which is for the final consumption in the UK itself. The average consumption water footprint of the UK is more than three times bigger than the UK production water footprint in 2006. About half of the UK consumption water footprints were associated with imports from Non-OECD countries (many of which are water-scarce, while around 19% were from EU-OECD countries, and only 3% from Non-EU-OECD countries. We find that the water footprint differs considerably across sub-national geographies in the UK, and the differences are as big as 273 m3/cap/year for the internal water footprint and 802 m3/cap/year for the external water footprint. Our results suggest

  7. Best-fit model of exploratory and confirmatory factor analysis of the 2010 Medical Council of Canada Qualifying Examination Part I clinical decision-making cases

    Directory of Open Access Journals (Sweden)

    André F. De Champlain

    2015-04-01

    Full Text Available Purpose: This study aims to assess the fit of a number of exploratory and confirmatory factor analysis models to the 2010 Medical Council of Canada Qualifying Examination Part I (MCCQE1 clinical decision-making (CDM cases. The outcomes of this study have important implications for a range of domains, including scoring and test development. Methods: The examinees included all first-time Canadian medical graduates and international medical graduates who took the MCCQE1 in spring or fall 2010. The fit of one- to five-factor exploratory models was assessed for the item response matrix of the 2010 CDM cases. Five confirmatory factor analytic models were also examined with the same CDM response matrix. The structural equation modeling software program Mplus was used for all analyses. Results: Out of the five exploratory factor analytic models that were evaluated, a three-factor model provided the best fit. Factor 1 loaded on three medicine cases, two obstetrics and gynecology cases, and two orthopedic surgery cases. Factor 2 corresponded to pediatrics, and the third factor loaded on psychiatry cases. Among the five confirmatory factor analysis models examined in this study, three- and four-factor lifespan period models and the five-factor discipline models provided the best fit. Conclusion: The results suggest that knowledge of broad disciplinary domains best account for performance on CDM cases. In test development, particular effort should be placed on developing CDM cases according to broad discipline and patient age domains; CDM testlets should be assembled largely using the criteria of discipline and age.

  8. An Empirical Study Of Productivity Growth In EU28 - Spatial Panel Analysis

    Directory of Open Access Journals (Sweden)

    Olejnik Alicja

    2014-12-01

    Full Text Available This paper investigates the spatial process of productivity growth in the European Union on the foundations of the theory of New Economic Geography. The proposed model is based on the study of NUTS 2 regions and takes into consideration a spatial weights matrix in order to better describe the structure of spatial dependence between EU regions. Furthermore, our paper attempts to investigate the applicability of some new approaches to spatial modelling including parameterization of the spatial weights matrix. Our study presents an application of the spatial panel model with fixed effects to Fingleton’s theoretical framework. We suggest that the applied approach constitutes an innovation to spatial econometric studies providing additional information hence, a deeper analysis of the investigated problem.

  9. THE APPLICATION OF AN EXPLORATORY FACTOR ANALYSIS TO INVESTIGATE THE INTER-RELATIONSHIPS AMONGST JOINT MOVEMENT DURING PERFORMANCE OF A FOOTBALL SKILL

    Directory of Open Access Journals (Sweden)

    Christina Smith

    2006-12-01

    Full Text Available Many studies have investigated the kinematics of sports skills with the majority describing the kinematics of the technique or investigating significant kinematic variables that affect performance. Many sports skills are complex three-dimensional movements involving many joints. However, few studies have investigated the relationships between kinematic variables during performance of such skills. The aim of this study was to investigate the inter- relationships among three-dimensional kinematic variables during performance of a lofted instep soccer kick. A motion analysis system was used to collect kinematic data for 13 skilled amateur soccer players attempting a standardised lofted instep kick. Three-dimensional angular displacement patterns were reported for the thoracolumbar spine and right hip joints. Two-dimensional angular displacement data was reported for the right knee and ankle joints. An exploratory rather than confirmatory factor analysis was applied, as there is currently no established theory regarding the kinematics of a lofted instep kick. Factors were extracted using the Maximum Likelihood Solution and orthogonally rotated using Varimax with Kaiser normalisation. The inter-relationship among biomechanical variables within the seven extracted factors was analysed with each factor revealing previously unknown inter-relationships among variables for different aspects of the kick. The use of exploratory factor analysis has shown the complex three-dimensional kinematic inter-relationships for a lofted instep kick. An understanding of these relationships could prove useful to coaches when instructing, and in the development of coaching programmes related to the lofted instep kick

  10. Exploratory analysis of textual data from the Mother and Child Handbook using the text-mining method: Relationships with maternal traits and post-partum depression.

    Science.gov (United States)

    Matsuda, Yoshio; Manaka, Tomoko; Kobayashi, Makiko; Sato, Shuhei; Ohwada, Michitaka

    2016-06-01

    The aim of the present study was to examine the possibility of screening apprehensive pregnant women and mothers at risk for post-partum depression from an analysis of the textual data in the Mother and Child Handbook by using the text-mining method. Uncomplicated pregnant women (n = 58) were divided into two groups according to State-Trait Anxiety Inventory grade (high trait [group I, n = 21] and low trait [group II, n = 37]) or Edinburgh Postnatal Depression Scale score (high score [group III, n = 15] and low score [group IV, n = 43]). An exploratory analysis of the textual data from the Maternal and Child Handbook was conducted using the text-mining method with the Word Miner software program. A comparison of the 'structure elements' was made between the two groups. The number of structure elements extracted by separated words from text data was 20 004 and the number of structure elements with a threshold of 2 or more as an initial value was 1168. Fifteen key words related to maternal anxiety, and six key words related to post-partum depression were extracted. The text-mining method is useful for the exploratory analysis of textual data obtained from pregnant woman, and this screening method has been suggested to be useful for apprehensive pregnant women and mothers at risk for post-partum depression. © 2016 Japan Society of Obstetrics and Gynecology.

  11. Statistical analysis of long term spatial and temporal trends of ...

    Indian Academy of Sciences (India)

    ). It is not uniform either spatially or temporally over the Himalayan region. A positive relationship between altitude and warming rate has been observed over the Greater. Keywords. Temperature; CGCM3; HadCM3; modified Mann–Kendall test ...

  12. Geometric anisotropic spatial point pattern analysis and Cox processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Toftaker, Håkon

    . In particular we study Cox process models with an elliptical pair correlation function, including shot noise Cox processes and log Gaussian Cox processes, and we develop estimation procedures using summary statistics and Bayesian methods. Our methodology is illustrated on real and synthetic datasets of spatial...

  13. Use of artificial neural network for spatial rainfall analysis

    Indian Academy of Sciences (India)

    A Geographic Information System (GIS) was utilized to process the data derived by the ANN and to create a continuous surface that represented the spatial mean annual precipitation distribution.The ANN introduced an optimization procedure that was implemented during training, adjusting the hidden number of neurons ...

  14. A preliminary survey and analysis of the spatial distribution of ...

    African Journals Online (AJOL)

    The spatial distribution of aquatic macroinvertebrates in the Okavango River Delta, Botswana, was investigated during the lowwater period in February 2003. This complements an earlier study undertaken during high-water in June 2000. Seventy-five samples were taken in a range of aquatic habitats at 29 georeference ...

  15. Tucker tensor analysis of Matern functions in spatial statistics

    KAUST Repository

    Litvinenko, Alexander

    2018-04-20

    Low-rank Tucker tensor methods in spatial statistics 1. Motivation: improve statistical models 2. Motivation: disadvantages of matrices 3. Tools: Tucker tensor format 4. Tensor approximation of Matern covariance function via FFT 5. Typical statistical operations in Tucker tensor format 6. Numerical experiments

  16. Use of artificial neural network for spatial rainfall analysis

    Indian Academy of Sciences (India)

    In the present study, the precipitation data measured at 23 rain gauge stations over the Achaia County,. Greece, were used to estimate the spatial distribution of the mean annual precipitation values over a specific catchment area. The objective of this work was achieved by programming an Artificial Neural. Network (ANN) ...

  17. Analysis of spatial count data using Kalman smoothing

    DEFF Research Database (Denmark)

    Dethlefsen, Claus

    2007-01-01

    We consider spatial count data from an agricultural field experiment. Counts of weed plants in a field have been recorded in a project on precision farming. Interest is in mapping the weed intensity so that the dose of herbicide applied at any location can be adjusted to the amount of weed present...

  18. Analysis of spatial count data using Kalman smoothing

    DEFF Research Database (Denmark)

    Dethlefsen, Claus

    This paper considers spatial count data from an agricultural field experiment. Counts of weed plants in a field have been recorded in a project on precision farming. Interest is in mapping the weed intensity so that the dose of herbicide applied at any location can be adjusted to the amount of weed...

  19. An analysis of trends in spatial mobility of Dutch graduates

    NARCIS (Netherlands)

    Venhorst, Viktor; Van Dijk, Jouke; Van Wissen, Leo

    Considerable attention in the literature has been devoted to spatial mobility as a mechanism in the transition from study to work. In this paper, the relationships between migration and both regional economic circumstances and individual characteristics are investigated using a micro-dataset on

  20. Rockfall hazard analysis using LiDAR and spatial modeling

    Science.gov (United States)

    Lan, Hengxing; Martin, C. Derek; Zhou, Chenghu; Lim, Chang Ho

    2010-05-01

    Rockfalls have been significant geohazards along the Canadian Class 1 Railways (CN Rail and CP Rail) since their construction in the late 1800s. These rockfalls cause damage to infrastructure, interruption of business, and environmental impacts, and their occurrence varies both spatially and temporally. The proactive management of these rockfall hazards requires enabling technologies. This paper discusses a hazard assessment strategy for rockfalls along a section of a Canadian railway using LiDAR and spatial modeling. LiDAR provides accurate topographical information of the source area of rockfalls and along their paths. Spatial modeling was conducted using Rockfall Analyst, a three dimensional extension to GIS, to determine the characteristics of the rockfalls in terms of travel distance, velocity and energy. Historical rockfall records were used to calibrate the physical characteristics of the rockfall processes. The results based on a high-resolution digital elevation model from a LiDAR dataset were compared with those based on a coarse digital elevation model. A comprehensive methodology for rockfall hazard assessment is proposed which takes into account the characteristics of source areas, the physical processes of rockfalls and the spatial attribution of their frequency and energy.

  1. Spatial variation in school performance, a local analysis of socio ...

    African Journals Online (AJOL)

    Setup

    Poor pass rates of matric learners at secondary schools in South Africa has been a concern for quite some time. Despite .... methods for spatial data within GIS leads to an increase in the potential for gaining new insight. (Fotheringham et al., 2001, ..... New South Wales Department of Education and. Training. Jaggia, S and ...

  2. SPATIAL ANALYSIS OF RESIDENTS' FEAR AND FEELING OF ...

    African Journals Online (AJOL)

    Osondu

    Abstract. This study examined spatial pattern of crime and residents' fear and feeling of insecurity in Ile-Ife,. Nigeria. To obtain the primary data, Ile-Ife was stratified into four residential zones namely traditional town centre, middle income, high income and post-crisis residential areas. Sample was selected using systematic ...

  3. Phenylketonuria and Complex Spatial Visualization: An Analysis of Information Processing.

    Science.gov (United States)

    Brunner, Robert L.; And Others

    1987-01-01

    The study of the ability of 16 early treated phenylketonuric (PKU) patients (ages 6-23 years) to solve complex spatial problems suggested that choice of problem-solving strategy, attention span, and accuracy of mental representation may be affected in PKU patients, despite efforts to maintain well-controlled phenylalanine concentrations in the…

  4. Combining Linguistic and Spatial Information for Document Analysis

    NARCIS (Netherlands)

    Aiello, Marco; Monz, Christof; Todoran, Leon

    2000-01-01

    We present a framework to analyze color documents of complex layout. In addition, no assumption is made on the layout. Our framework combines in a content-driven bottom-up approach two different sources of information: textual and spatial. To analyze the text, shallow natural language processing

  5. Spatial analysis of feline immunodeficiency virus infection in cougars.

    Science.gov (United States)

    Wheeler, David C; Waller, Lance A; Biek, Roman

    2010-07-01

    The cougar (Puma concolor) is a large predatory feline found widely in the Americas that is susceptible to feline immunodeficiency virus (FIV), a fast-evolving lentivirus found in wild feline species that is analogous to simian immunodeficiency viruses in wild primates and belongs to the same family of viruses as human immunodeficiency virus. FIV infection in cougars can lead to a weakened immune system that creates opportunities for other infecting agents. FIV prevalence and lineages have been studied previously in several areas in the western United States, but typically without spatially explicit statistical techniques. To describe the distribution of FIV in a sample of cougars located in the northern Rocky Mountain region of North America, we first used kernel density ratio estimation to map the log relative risk of FIV. The risk surface showed a significant cluster of FIV in northwestern Montana. We also used Bayesian cluster models for genetic data to investigate the spatial structure of the feline immunodeficiency virus with virus genetic sequence data. A result of the models was two spatially distinct FIV lineages that aligned considerably with an interstate highway in Montana. Our results suggest that the use of spatial information and models adds novel insight when investigating an infectious animal disease. The results also suggest that the influence of landscape features likely plays an important role in the spatiotemporal spread of an infectious disease within wildlife populations.

  6. The Application of Spatial Pattern Analysis in High School Level ...

    African Journals Online (AJOL)

    Geography is a vital subject of the school curriculum which is creative, practical and intellectually stimulating. It tries to identify features on the field, their spatial pattern as well as give explanations to process which have generated the observed distributional patterns their location and provide scientific explanation for the ...

  7. Spatial analysis of digital technologies and impact on socio - cultural ...

    African Journals Online (AJOL)

    At 5% level of significance, results showed that the advent of digital technologies have significant impact on socio - cultural values. The study reveals strong spatial dependence of households with television and mobile phone in Nigeria. The findings should enable the orientation of social transformation programmes geared ...

  8. Spatial and Statistical Analysis of Leptospirosis in Guilan Province, Iran

    Science.gov (United States)

    Nia, A. Mohammadi; Alimohammadi, A.; Habibi, R.; Shirzadi, M. R.

    2015-12-01

    The most underdiagnosed water-borne bacterial zoonosis in the world is Leptospirosis which especially impacts tropical and humid regions. According to World Health Organization (WHO), the number of human cases is not known precisely. Available reports showed that worldwide incidences vary from 0.1-1 per 100 000 per year in temperate climates to 10-100 per 100 000 in the humid tropics. Pathogenic bacteria that is spread by the urines of rats is the main reason of water and soil infections. Rice field farmers who are in contact with infected water or soil, contain the most burden of leptospirosis prevalence. In recent years, this zoonotic disease have been occurred in north of Iran endemically. Guilan as the second rice production province (average=750 000 000 Kg, 40% of country production) after Mazandaran, has one of the most rural population (Male=487 679, Female=496 022) and rice workers (47 621 insured workers) among Iran provinces. The main objectives of this study were to analyse yearly spatial distribution and the possible spatial clusters of leptospirosis to better understand epidemiological aspects of them in the province. Survey was performed during the period of 2009-2013 at rural district level throughout the study area. Global clustering methods including the average nearest neighbour distance, Moran's I and General G indices were utilized to investigate the annual spatial distribution of diseases. At the end, significant spatial clusters have been detected with the objective of informing priority areas for public health planning and resource allocation.

  9. Backyard housing in Gauteng: An analysis of spatial dynamics ...

    African Journals Online (AJOL)

    This article examines the phenomenon of backyard housing in Gauteng, a prominent driver of urban spatial change in South Africa's housing market. Backyard housing in South Africa increasingly attracts the attention of policymakers because of the large number of households that this sector accommodates. Moreover, the ...

  10. A Spatial Analysis of Population Distribution and Housing Patterns ...

    African Journals Online (AJOL)

    ... administered using the stratified randomsampling technique. The study area was divided into three major zones based on existing quarters in Abraka. The Pearson product moment correlation was used to measure the strength of the relationship between the spatial patterns of population and housing in Abraka. Solutions ...

  11. Analysis of spatial distribution of land cover maps accuracy

    Science.gov (United States)

    Khatami, R.; Mountrakis, G.; Stehman, S. V.

    2017-12-01

    Land cover maps have become one of the most important products of remote sensing science. However, classification errors will exist in any classified map and affect the reliability of subsequent map usage. Moreover, classification accuracy often varies over different regions of a classified map. These variations of accuracy will affect the reliability of subsequent analyses of different regions based on the classified maps. The traditional approach of map accuracy assessment based on an error matrix does not capture the spatial variation in classification accuracy. Here, per-pixel accuracy prediction methods are proposed based on interpolating accuracy values from a test sample to produce wall-to-wall accuracy maps. Different accuracy prediction methods were developed based on four factors: predictive domain (spatial versus spectral), interpolation function (constant, linear, Gaussian, and logistic), incorporation of class information (interpolating each class separately versus grouping them together), and sample size. Incorporation of spectral domain as explanatory feature spaces of classification accuracy interpolation was done for the first time in this research. Performance of the prediction methods was evaluated using 26 test blocks, with 10 km × 10 km dimensions, dispersed throughout the United States. The performance of the predictions was evaluated using the area under the curve (AUC) of the receiver operating characteristic. Relative to existing accuracy prediction methods, our proposed methods resulted in improvements of AUC of 0.15 or greater. Evaluation of the four factors comprising the accuracy prediction methods demonstrated that: i) interpolations should be done separately for each class instead of grouping all classes together; ii) if an all-classes approach is used, the spectral domain will result in substantially greater AUC than the spatial domain; iii) for the smaller sample size and per-class predictions, the spectral and spatial domain

  12. Distributed multi-criteria model evaluation and spatial association analysis

    Science.gov (United States)

    Scherer, Laura; Pfister, Stephan

    2015-04-01

    Model performance, if evaluated, is often communicated by a single indicator and at an aggregated level; however, it does not embrace the trade-offs between different indicators and the inherent spatial heterogeneity of model efficiency. In this study, we simulated the water balance of the Mississippi watershed using the Soil and Water Assessment Tool (SWAT). The model was calibrated against monthly river discharge at 131 measurement stations. Its time series were bisected to allow for subsequent validation at the same gauges. Furthermore, the model was validated against evapotranspiration which was available as a continuous raster based on remote sensing. The model performance was evaluated for each of the 451 sub-watersheds using four different criteria: 1) Nash-Sutcliffe efficiency (NSE), 2) percent bias (PBIAS), 3) root mean square error (RMSE) normalized to standard deviation (RSR), as well as 4) a combined indicator of the squared correlation coefficient and the linear regression slope (bR2). Conditions that might lead to a poor model performance include aridity, a very flat and steep relief, snowfall and dams, as indicated by previous research. In an attempt to explain spatial differences in model efficiency, the goodness of the model was spatially compared to these four phenomena by means of a bivariate spatial association measure which combines Pearson's correlation coefficient and Moran's index for spatial autocorrelation. In order to assess the model performance of the Mississippi watershed as a whole, three different averages of the sub-watershed results were computed by 1) applying equal weights, 2) weighting by the mean observed river discharge, 3) weighting by the upstream catchment area and the square root of the time series length. Ratings of model performance differed significantly in space and according to efficiency criterion. The model performed much better in the humid Eastern region than in the arid Western region which was confirmed by the

  13. Analysis of a spatial orientation memory in Drosophila.

    Science.gov (United States)

    Neuser, Kirsa; Triphan, Tilman; Mronz, Markus; Poeck, Burkhard; Strauss, Roland

    2008-06-26

    Flexible goal-driven orientation requires that the position of a target be stored, especially in case the target moves out of sight. The capability to retain, recall and integrate such positional information into guiding behaviour has been summarized under the term spatial working memory. This kind of memory contains specific details of the presence that are not necessarily part of a long-term memory. Neurophysiological studies in primates indicate that sustained activity of neurons encodes the sensory information even though the object is no longer present. Furthermore they suggest that dopamine transmits the respective input to the prefrontal cortex, and simultaneous suppression by GABA spatially restricts this neuronal activity. Here we show that Drosophila melanogaster possesses a similar spatial memory during locomotion. Using a new detour setup, we show that flies can remember the position of an object for several seconds after it has been removed from their environment. In this setup, flies are temporarily lured away from the direction towards their hidden target, yet they are thereafter able to aim for their former target. Furthermore, we find that the GABAergic (stainable with antibodies against GABA) ring neurons of the ellipsoid body in the central brain are necessary and their plasticity is sufficient for a functional spatial orientation memory in flies. We also find that the protein kinase S6KII (ignorant) is required in a distinct subset of ring neurons to display this memory. Conditional expression of S6KII in these neurons only in adults can restore the loss of the orientation memory of the ignorant mutant. The S6KII signalling pathway therefore seems to be acutely required in the ring neurons for spatial orientation memory in flies.

  14. Advanced spatial metrics analysis in cellular automata land use and cover change modeling

    International Nuclear Information System (INIS)

    Zamyatin, Alexander; Cabral, Pedro

    2011-01-01

    This paper proposes an approach for a more effective definition of cellular automata transition rules for landscape change modeling using an advanced spatial metrics analysis. This approach considers a four-stage methodology based on: (i) the search for the appropriate spatial metrics with minimal correlations; (ii) the selection of the appropriate neighborhood size; (iii) the selection of the appropriate technique for spatial metrics application; and (iv) the analysis of the contribution level of each spatial metric for joint use. The case study uses an initial set of 7 spatial metrics of which 4 are selected for modeling. Results show a better model performance when compared to modeling without any spatial metrics or with the initial set of 7 metrics.

  15. Analysis Of Influence Of Spatial Planning On Performance Of Regional Development At Waropen District. Papua Indonesia

    Directory of Open Access Journals (Sweden)

    Suwandi

    2015-08-01

    Full Text Available The various problems in regional spatial planning in Waropen District Papua shows that the Spatial Planning RTRW of Waropen District Papua drafted in 2010 has not had a positive contribution to the settlement of spatial planning problems. This is most likely caused by the inconsistency in the spatial planning. This study tried to observe the consistency of spatial planning as well as its relation to the regional development performance. The method used to observe the consistency of the preparation of guided Spatial Planning RTRW is the analysis of comparative table followed by analysis of verbal logic. In order to determine if the preparation of Spatial Planning RTRW has already paid attention on the synergy with the surrounding regions Inter-Regional Context a map overlay was conducted followed by analysis of verbal logic. To determine the performance of the regional development a Principal Components Analysis PCA was done. The analysis results showed that inconsistencies in the spatial planning had caused a variety of problems that resulted in decreased performance of the regional development. The main problems that should receive more attention are infrastructure development growth economic growth transportation aspect and new properties.

  16. Supporting exploratory information seeking

    OpenAIRE

    Haraty, Monasadat

    2010-01-01

    Exploratory search is a sensemaking activity that involves information seeking and iterative development of mental model of the domain under exploration. It often begins with a vague and evolving information need that is multidimensional. We designed and developed a web-browser extension to facilitate exploratory web search aiming at transforming the search activity into a meaningful learning activity. The design is based on the proposed multi-threaded model of exploratory search. According t...

  17. Disruption of exploratory and habituation behavior in mice with mutation of DISC1: an ethologically based analysis.

    Science.gov (United States)

    Walsh, J; Desbonnet, L; Clarke, N; Waddington, J L; O'Tuathaigh, C M P

    2012-07-01

    Disrupted-in-schizophrenia-1 (DISC1) is a gene that has been functionally linked with neurodevelopmental processes and structural plasticity in the brain. Clinical genetic investigations have implicated DISC1 as a genetic risk factor for schizophrenia and related psychoses. Studies using mutant mouse models of DISC1 gene function have demonstrated schizophrenia-related anatomical and behavioral endophenotypes. In the present study, ethologically based assessment of exploratory and habituation behavior in the open field was conducted in DISC1 (L100P), wild-type (WT), heterozygous (HET), and homozygous (HOM) mutant mice of both sexes. Ethological assessment was conducted in an open-field environment to explore specific topographies of murine exploratory behavior across the extended course of interaction from initial exploration through subsequent habituation (the ethogram). During initial exploration, HET and HOM DISC1 mutants evidenced increased levels of locomotion and rearing to wall compared with WT. A HOM-specific increase in total rearing and a HET-specific increase in sifting behavior and reduction in rearing seated were also observed. Over subsequent habituation, locomotion, sniffing, total rearing, rearing to wall, rearing free, and rearing seated were increased in HET and HOM mutants vs. WT. Overall, grooming was increased in HOM relative to other genotypes. HET mice displayed a selective decrease in habituation of sifting behavior. These data demonstrate impairment in both initial exploratory and habituation of exploration in a novel environment in mice with mutation of DISC1. This is discussed in the context of the functional role of the gene vis à vis a schizophrenia phenotype as well as the value of ethologically based approaches to behavioral phenotyping. Copyright © 2012 Wiley Periodicals, Inc.

  18. Spatial Autocorrelation Analysis of Chinese Inter-Provincial Industrial Chemical Oxygen Demand Discharge

    Directory of Open Access Journals (Sweden)

    Yibo Liu

    2012-05-01

    Full Text Available A spatial autocorrelation analysis method is adopted to process the spatial dynamic change of industrial Chemical Oxygen Demand (COD discharge in China over the past 15 years. Studies show that amount and intensity of industrial COD discharges are on a decrease, and the tendency is more remarkable for discharge intensity. There are large differences between inter-provincial discharge amount and intensity, and with different spatial differentiation features. Global spatial autocorrelation analysis reveals that Global Moran’s I of discharge amount and intensity is on the decrease. In space, there is an evolution from an agglomeration pattern to a discretization pattern. Local spatial autocorrelation analysis shows that the agglomeration area of industrial COD discharge amount and intensity varies greatly in space with time. Stringent environmental regulations and increased funding for environmental protections are the crucial factors to cut down industrial COD discharge amount and intensity.

  19. Spatial autocorrelation analysis of Chinese inter-provincial industrial chemical oxygen demand discharge.

    Science.gov (United States)

    Zhao, Xiaofeng; Huang, Xianjin; Liu, Yibo

    2012-06-01

    A spatial autocorrelation analysis method is adopted to process the spatial dynamic change of industrial Chemical Oxygen Demand (COD) discharge in China over the past 15 years. Studies show that amount and intensity of industrial COD discharges are on a decrease, and the tendency is more remarkable for discharge intensity. There are large differences between inter-provincial discharge amount and intensity, and with different spatial differentiation features. Global spatial autocorrelation analysis reveals that Global Moran's I of discharge amount and intensity is on the decrease. In space, there is an evolution from an agglomeration pattern to a discretization pattern. Local spatial autocorrelation analysis shows that the agglomeration area of industrial COD discharge amount and intensity varies greatly in space with time. Stringent environmental regulations and increased funding for environmental protections are the crucial factors to cut down industrial COD discharge amount and intensity.

  20. Spatial recurrence analysis: A sensitive and fast detection tool in digital mammography

    International Nuclear Information System (INIS)

    Prado, T. L.; Galuzio, P. P.; Lopes, S. R.; Viana, R. L.

    2014-01-01

    Efficient diagnostics of breast cancer requires fast digital mammographic image processing. Many breast lesions, both benign and malignant, are barely visible to the untrained eye and requires accurate and reliable methods of image processing. We propose a new method of digital mammographic image analysis that meets both needs. It uses the concept of spatial recurrence as the basis of a spatial recurrence quantification analysis, which is the spatial extension of the well-known time recurrence analysis. The recurrence-based quantifiers are able to evidence breast lesions in a way as good as the best standard image processing methods available, but with a better control over the spurious fragments in the image

  1. The Nexus of Place and Finance in the Analysis of Educational Attainment: A Spatial Econometric Approach

    Science.gov (United States)

    Sutton, Farah

    2012-01-01

    This study examines the spatial distribution of educational attainment and then builds upon current predictive frameworks for understanding patterns of educational attainment by applying a spatial econometric method of analysis. The research from this study enables a new approach to the policy discussion on how to improve educational attainment…

  2. Diversity and ecology of the potato : the use of spatial analysis in crop science

    NARCIS (Netherlands)

    Hijmans, R.J.

    2002-01-01

    Spatial variation is a fundamental characteristic of agriculture, but crop scientists have largely ignored it, particularly at levels beyond the field scale. This thesis provides examples of analysis of spatial variation over larger

  3. Components of spatial information management in wildlife ecology: Software for statistical and modeling analysis [Chapter 14

    Science.gov (United States)

    Hawthorne L. Beyer; Jeff Jenness; Samuel A. Cushman

    2010-01-01

    Spatial information systems (SIS) is a term that describes a wide diversity of concepts, techniques, and technologies related to the capture, management, display and analysis of spatial information. It encompasses technologies such as geographic information systems (GIS), global positioning systems (GPS), remote sensing, and relational database management systems (...

  4. Quantification of a single exploratory trip reveals hippocampal formation mediated dead reckoning.

    Science.gov (United States)

    Wallace, Douglas G; Hines, Dustin J; Whishaw, Ian Q

    2002-01-30

    A rat's proclivity to explore a novel environment presents a behaviorally rich paradigm to investigate the role of the hippocampus in spatial navigation. Here we describe a novel technique of behavioral analysis that is derived from a single exploratory trip. An exploratory trip was defined as a rat's departure from the home base that ended when the rat returned to the home base. The behavior observed on a single exploratory trip by a control animal is highly organized into outward and homeward segments. An outward segment is characterized by a slow circuitous progression from the home base marked by several stops. A homeward segment is characterized by a rapid direct return to the home base. The velocity attribute of the exploratory trip was quantified by estimating the point of inflection associated with the trip's cumulative moment-to-moment velocity distribution. The heading direction and variance of the homeward trip segment was analyzed with circular statistics. A comparison of the exploratory behavior of control animals and animals with damage to the fimbria-fornix indicated that the velocity and heading direction of the homeward portion of the trip depends upon the hippocampal formation. While control and fimbria-fornix rats had similar outward segments, the return paths of the fimbria-fornix rats were significantly slower, more circuitous, and more variable compared with that of the control rats. This result was also independent of testing in light or dark conditions. The lack of dependence on allothetic cues suggests that rats employ dead reckoning navigational strategies to initiate the homeward portion of exploratory movements. Methods to quantify exploratory behavior in terms of velocity and angular components provide an assessment of control behavior and the assessment of the behavior of rats with hippocampal formation damage that is easy to implement.

  5. Analysis of SWOT spatial and temporal samplings over continents

    Science.gov (United States)

    Biancamaria, Sylvain; Lamy, Alain; Mognard, Nelly

    2014-05-01

    The future Surface Water and Ocean Topography (SWOT) satellite mission, collaboratively developed by NASA, CNES and CSA, is a joint oceanography/continental hydrology mission planned for launch in 2020. In June 2013, a new SWOT orbit has been selected with a 77.6° inclination, a 21 days repeat cycle and a 891 km altitude. The main satellite payload (a Ka-band SAR Interferometer), will provide 2D maps of water elevation, mask and slope over two swaths, both having a 50 km extent. These two swaths will be separated by a 20 km nadir gap. Most of the studies concerning SWOT published since 2007 have considered a former orbit with a 78° inclination, 22 day repeat orbit and a 970 km altitude and a 60 km extent for each swath. None of them have studied the newly selected orbit and the impact of the 20 km nadir gap on the spatial coverage has not been much explored. The purpose of the work presented here is to investigate the spatial and temporal coverage given this new orbit and the actual swath extent (2*50 km swaths with the 20 km nadir gap in between) and compare it to the former SWOT configuration. It is shown that the new configuration will have almost no impact on the computation of monthly averages, however it will impact the spatial coverage. Because of the nadir gap, the orbit repeatitivity and the swaths extent, 3.6% of the continental surfaces in between 78°S and 78°N will never be observed by SWOT (which was previously equal to 2.2% with the former SWOT configuration). The equatorial regions will be the most impacted, as uncovered area could go up to ~14% locally, whereas it never exceeded 9% with the previous SWOT configuration.

  6. Spatial data analysis and integration for regional-scale geothermal potential mapping, West Java, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Carranza, Emmanuel John M.; Barritt, Sally D. [Department of Earth Systems Analysis, International Institute for Geo-information Science and Earth Observation (ITC), Enschede (Netherlands); Wibowo, Hendro; Sumintadireja, Prihadi [Laboratory of Volcanology and Geothermal, Geology Department, Institute of Technology Bandung (ITB), Bandung (Indonesia)

    2008-06-15

    Conceptual modeling and predictive mapping of potential for geothermal resources at the regional-scale in West Java are supported by analysis of the spatial distribution of geothermal prospects and thermal springs, and their spatial associations with geologic features derived from publicly available regional-scale spatial data sets. Fry analysis shows that geothermal occurrences have regional-scale spatial distributions that are related to Quaternary volcanic centers and shallow earthquake epicenters. Spatial frequency distribution analysis shows that geothermal occurrences have strong positive spatial associations with Quaternary volcanic centers, Quaternary volcanic rocks, quasi-gravity lows, and NE-, NNW-, WNW-trending faults. These geological features, with their strong positive spatial associations with geothermal occurrences, constitute spatial recognition criteria of regional-scale geothermal potential in a study area. Application of data-driven evidential belief functions in GIS-based predictive mapping of regional-scale geothermal potential resulted in delineation of high potential zones occupying 25% of West Java, which is a substantial reduction of the search area for further exploration of geothermal resources. The predicted high potential zones delineate about 53-58% of the training geothermal areas and 94% of the validated geothermal occurrences. The results of this study demonstrate the value of regional-scale geothermal potential mapping in: (a) data-poor situations, such as West Java, and (b) regions with geotectonic environments similar to the study area. (author)

  7. Is Spatial Resolution Critical in Urbanization Velocity Analysis? Investigations in the Pearl River Delta

    Directory of Open Access Journals (Sweden)

    Chunzhu Wei

    2017-01-01

    Full Text Available Grid-based urbanization velocity analysis of remote sensing imagery is used to measure urban growth rates. However, it remains unclear how critical the spatial resolution of the imagery is to such grid-based approaches. This research therefore investigated how urbanization velocity estimates respond to different spatial resolutions, as determined by the grid sizes used. Landsat satellite images of the Pearl River Delta (PRD in China from the years 2000, 2005, 2010 and 2015 were hierarchically aggregated using different grid sizes. Statistical analyses of urbanization velocity derived using different spatial resolutions (or grid sizes were used to investigate the relationships between socio-economic indicators and the velocity of urbanization for 27 large cities in PRD. The results revealed that those cities with above-average urbanization velocities remain unaffected by the spatial resolution (or grid-size, and the relationships between urbanization velocities and socio-economic indicators are independent of spatial resolution (or grid sizes used. Moreover, empirical variogram models, the local variance model, and the geographical variance model all indicated that coarse resolution version (480 m of Landsat images based on aggregated pixel yielded more appropriate results than the original fine resolution version (30 m, when identifying the characteristics of spatial autocorrelation and spatial structure variability of urbanization patterns and processes. The results conclude that the most appropriate spatial resolution for investigations into urbanization velocities is not always the highest resolution. The resulting patterns of urbanization velocities at different spatial resolutions can be used as a basis for studying the spatial heterogeneity of other datasets with variable spatial resolutions, especially for evaluating the capability of a multi-resolution dataset in reflecting spatial structure and spatial autocorrelation features in an

  8. Geoscience after ITPart G. Familiarization with spatial analysis

    Science.gov (United States)

    Pundt, Hardy; Brinkkötter-Runde, Klaus

    2000-04-01

    Field based and GPS supported GIS are increasingly applied in various spatial disciplines. Such systems represent more sophisticated, time and cost effective tools than traditional field forms for data acquisition. Meanwhile, various systems are on the market. These mostly enable the user to define geo-objects by means of GPS information, supported by functionalities to collect and analyze geometric information. The digital acquisition of application specific attributes is often underrepresented within such systems. This is surprising because pen computer based GIS can be used to collect attributes in a profitable manner, thus adequately supporting the requirements of the user. Visualization and graphic displays of spatial data are helpful means to improve such a data collection process. In section one and two basic aspects of visualization and current uses of visualization techniques for field based GIS are described. Section three mentions new developments within the framework of wearable computing and augmented reality. Section four describes current activities aimed at the realization of real time online field based GIS. This includes efforts to realize an online GIS data link to improve the efficiency and the quality of fieldwork. A brief discussion in section five leads to conclusions and some key issues for future research.

  9. SPATIALLY ADAPTIVE SEMI-SUPERVISED LEARNING WITH GAUSSIAN PROCESSES FOR HYPERSPECTRAL DATA ANALYSIS

    Data.gov (United States)

    National Aeronautics and Space Administration — SPATIALLY ADAPTIVE SEMI-SUPERVISED LEARNING WITH GAUSSIAN PROCESSES FOR HYPERSPECTRAL DATA ANALYSIS GOO JUN * AND JOYDEEP GHOSH* Abstract. A semi-supervised learning...

  10. Time dependent analysis of Xenon spatial oscillations in small power reactors

    International Nuclear Information System (INIS)

    Decco, Claudia Cristina Ghirardello

    1997-01-01

    This work presents time dependent analysis of xenon spatial oscillations studying the influence of the power density distribution, type of reactivity perturbation, power level and core size, using the one-dimensional and three-dimensional analysis with the MID2 and citation codes, respectively. It is concluded that small pressurized water reactors with height smaller than 1.5 m are stable and do not have xenon spatial oscillations. (author)

  11. Exploratory analysis of verbal aggression in romantic relationships among unmarried men and women: Predictive patterns by gender and race

    Science.gov (United States)

    Chung, Grace H.; Tucker, M. Belinda; Li, Gang; Zhou, Xiaomeng; Hwang, Sun

    2011-01-01

    This is an exploratory study that examined verbal aggression in romantic relationships among unmarried Black and White women and men as a function of gender and race. We employed an ecological approach to examine the receipt of verbal aggression separately for men and women at the levels of individual, relationship, and community. We also explored whether gender-specific correlates of verbal aggression interacted with race. Analyses were based on a sample of 212 women and 133 men in non-marital romantic relationships recruited from 21 U.S. cities for a larger study. Linear mixed-effects models revealed that factors related to experiencing verbal aggression differed substantially for unmarried women and men in romantic relationships. Interesting racial differences also emerged distinctly for women and men. PMID:22298940

  12. "Bringing home more than a paycheck:" an exploratory analysis of Black lesbians' experiences of stress and coping in the workplace.

    Science.gov (United States)

    Bowleg, Lisa; Brooks, Kelly; Ritz, Susan Faye

    2008-01-01

    Although the workplace stress that Black women and lesbian, gay, bisexual and transgender (LGBT) people experience due to prejudice and discrimination has been well-documented in the social science literature, much of this literature focuses on Black women or LGBTs as if these groups were distinct and mutually exclusive. Consequently, there is a void of theory and research on the workplace stress that Black lesbians experience. This qualitative study involved exploratory analyses of workplace stress due to race, sex/gender, and sexual orientation, and coping strategies among a predominantly middle-class, highly educated sample of 19 Black lesbians between the ages of 26 and 68. Four workplace stressors emerged, those relevant to: heterosexism/ sexual identity; racism/race; sexism/sex/gender; and intersections of race, sex/gender, and sexual orientation. Three primary coping strategies emerged: being out and managing being out, covering their sexual orientation, and confronting or educating coworkers about prejudice and discrimination.

  13. An Exploratory Analysis of the Relationship between Cardiometabolic Risk Factors and Cognitive/Academic Performance among Adolescents

    Directory of Open Access Journals (Sweden)

    Ting-Kuang Yeh

    2015-01-01

    Full Text Available This exploratory study examines the relationship between cardiometabolic risk factors (blood pressure, waist circumference, BMI, and total cholesterol and cognitive/academic performance. In this study, 1297 Taiwanese tenth-grade volunteers are recruited. Scores from the Basic Competency Test, an annual national competitive entrance examination, are used to evaluate academic performance. Cognitive abilities are accessed via the Multiple Aptitude Test Battery. The results indicate that systolic blood pressure is significantly, negatively associated with academic performance, both in male and female subjects. BMI and waist circumference are associated with verbal reasoning performance with an inverse U-shaped pattern, suggesting that both low and high BMI/waist circumference may be associated with lower verbal reasoning performance.

  14. Analysis of Spatial Interpolation in the Material-Point Method

    DEFF Research Database (Denmark)

    Andersen, Søren; Andersen, Lars

    2010-01-01

    This paper analyses different types of spatial interpolation for the material-point method The interpolations include quadratic elements and cubic splines in addition to the standard linear shape functions usually applied. For the small-strain problem of a vibrating bar, the best results...... are obtained using quadratic elements. It is shown that for more complex problems, the use of partially negative shape functions is inconsistent with the material-point method in its current form, necessitating other types of interpolation such as cubic splines in order to obtain smoother representations...... of field quantities The properties of different interpolation functions are analysed using numerical examples, including the classical cantil-evered beam problem....

  15. Suicide and media reporting: a longitudinal and spatial analysis.

    Science.gov (United States)

    Yang, Albert C; Tsai, Shih-Jen; Yang, Cheng-Hung; Shia, Ben-Chang; Fuh, Jong-Ling; Wang, Shuu-Jiun; Peng, Chung-Kang; Huang, Norden E

    2013-03-01

    The impact of media reporting on copycat suicides has been well established in various cases of celebrity suicide. However, knowledge is limited about the spatial and temporal relationship between suicide death and media reporting over a long period of time. This study investigated the association of suicide deaths with suicide news in longitudinal and spatial dimensions. All suicides during 2003-2010 (n = 31,364) were included. Suicide news in the study period was retrieved from Google News, and included all available news media in Taiwan. Empirical mode decomposition was used to identify the main intrinsic oscillation, reflecting both major and minor suicide events, and time-dependent intrinsic correlation was used to quantify the temporal correlation between suicide deaths and suicide news. The media reporting of suicide was synchronized with increased suicide deaths during major suicide events such as celebrity death, and slightly lagged behind the suicide deaths for 1 month in other periods without notable celebrity deaths. The means of suicide reported in the media diversely affected the suicide models. Reports of charcoal burning suicide exhibited an exclusive copycat effect on actual charcoal burning deaths, whereas media reports of jumping had a wide association with various suicide models. Media reports of suicide had a higher association with suicide deaths in urban than in rural areas. This report suggested that a delayed effect of copycat suicide may exist in media reports of minor suicide events. The competitive reporting of minor suicide events must be avoided and addressed by media professionals.

  16. Spatial and environmental connectivity analysis in a cholera vaccine trial.

    Science.gov (United States)

    Emch, Michael; Ali, Mohammad; Root, Elisabeth D; Yunus, Mohammad

    2009-02-01

    This paper develops theory and methods for vaccine trials that utilize spatial and environmental information. Satellite imagery is used to identify whether households are connected to one another via water bodies in a study area in rural Bangladesh. Then relationships between neighborhood-level cholera vaccine coverage and placebo incidence and neighborhood-level spatial variables are measured. The study hypothesis is that unvaccinated people who are environmentally connected to people who have been vaccinated will be at lower risk compared to unvaccinated people who are environmentally connected to people who have not been vaccinated. We use four datasets including: a cholera vaccine trial database, a longitudinal demographic database of the rural population from which the vaccine trial participants were selected, a household-level geographic information system (GIS) database of the same study area, and high resolution Quickbird satellite imagery. An environmental connectivity metric was constructed by integrating the satellite imagery with the vaccine and demographic databases linked with GIS. The results show that there is a relationship between neighborhood rates of cholera vaccination and placebo incidence. Thus, people are indirectly protected when more people in their environmentally connected neighborhood are vaccinated. This result is similar to our previous work that used a simpler Euclidean distance neighborhood to measure neighborhood vaccine coverage [Ali, M., Emch, M., von Seidlein, L., Yunus, M., Sack, D. A., Holmgren, J., et al. (2005). Herd immunity conferred by killed oral cholera vaccines in Bangladesh. Lancet, 366(9479), 44-49]. Our new method of measuring environmental connectivity is more precise since it takes into account the transmission mode of cholera and therefore this study validates our assertion that the oral cholera vaccine provides indirect protection in addition to direct protection.

  17. Particulate matter (PM10) patterns in Europe: An exploratory data analysis using non-negative matrix factorization

    Science.gov (United States)

    Žibert, Janez; Cedilnik, Jure; Pražnikar, Jure

    2016-05-01

    In last decade space-density of monitoring stations increased, in to addition also air pollution modeling made big progress. Using diversity of big data can lead to better knowledge about air pollution at continental scale. The focus of presented study is the data-driven approach using non-negative matrix factorization to provide new insights and to study the characteristic space-time particulate-matter patterns across Europe. We analyzed the PM10 concentrations obtained from 1097 monitoring stations (AirBase data) and the Monitoring Atmospheric Composition and Climate (MACC) modeled fields for a period of 3 years. We distinguished five characteristic patterns obtained from the AirBase data and five patterns from the MACC data. A comparison between the AirBase and MACC data shows a good spatial overlap for the east Europe, central Europe and the Mediterranean patterns. However, it should be noted that an analysis of the MACC data revealed two additional marine patterns: the Celtic and the North Seas. The Po Valley and Balkan patterns were very clearly identified when analyzing the AirBase data. In order to better understand the influence of the synoptic situation on the particulate-matter concentrations the synoptic meteorological situations were additionally analyzed. The cold season, low wind and very stable conditions, which can last for several days, is the most common situation linked to high concentrations of anthropogenic air pollution with particulate matter. In contrast, for the Mediterranean pattern the most common situation (high factor loadings) is observed during the summer period. This pattern also exhibits a clearer annual cycle. A closer look at the sea-salt patterns (Celtic and North Seas) shows low time-series correlations between these two factors. Nevertheless, the physical mechanism is the same: a steep gradient between the cyclone and the anti-cyclone that causes high winds and, consequently, higher sea-salt production.

  18. 3D spatially-adaptive canonical correlation analysis: Local and global methods.

    Science.gov (United States)

    Yang, Zhengshi; Zhuang, Xiaowei; Sreenivasan, Karthik; Mishra, Virendra; Curran, Tim; Byrd, Richard; Nandy, Rajesh; Cordes, Dietmar

    2018-04-01

    Local spatially-adaptive canonical correlation analysis (local CCA) with spatial constraints has been introduced to fMRI multivariate analysis for improved modeling of activation patterns. However, current algorithms require complicated spatial constraints that have only been applied to 2D local neighborhoods because the computational time would be exponentially increased if the same method is applied to 3D spatial neighborhoods. In this study, an efficient and accurate line search sequential quadratic programming (SQP) algorithm has been developed to efficiently solve the 3D local CCA problem with spatial constraints. In addition, a spatially-adaptive kernel CCA (KCCA) method is proposed to increase accuracy of fMRI activation maps. With oriented 3D spatial filters anisotropic shapes can be estimated during the KCCA analysis of fMRI time courses. These filters are orientation-adaptive leading to rotational invariance to better match arbitrary oriented fMRI activation patterns, resulting in improved sensitivity of activation detection while significantly reducing spatial blurring artifacts. The kernel method in its basic form does not require any spatial constraints and analyzes the whole-brain fMRI time series to construct an activation map. Finally, we have developed a penalized kernel CCA model that involves spatial low-pass filter constraints to increase the specificity of the method. The kernel CCA methods are compared with the standard univariate method and with two different local CCA methods that were solved by the SQP algorithm. Results show that SQP is the most efficient algorithm to solve the local constrained CCA problem, and the proposed kernel CCA methods outperformed univariate and local CCA methods in detecting activations for both simulated and real fMRI episodic memory data. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Quantitative spatial analysis of the mouse brain lipidome by pressurized liquid extraction surface analysis

    DEFF Research Database (Denmark)

    Almeida, Reinaldo; Berzina, Zane; Christensen, Eva Arnspang

    2015-01-01

    Here we describe a novel surface sampling technique termed pressurized liquid extraction surface analysis (PLESA), which in combination with a dedicated high-resolution shotgun lipidomics routine enables both quantification and in-depth structural characterization of molecular lipid species...... extracted directly from tissue sections. PLESA uses a sealed and pressurized sampling probe that enables the use of chloroform-containing extraction solvents for efficient in situ lipid microextraction with a spatial resolution of 400 μm. Quantification of lipid species is achieved by the inclusion...... of internal lipid standards in the extraction solvent. The analysis of lipid microextracts by nanoelectrospray ionization provides long-lasting ion spray which in conjunction with a hybrid ion trap-orbitrap mass spectrometer enables identification and quantification of molecular lipid species using a method...

  20. Application of spatial and non-spatial data analysis in determination of the factors that impact municipal solid waste generation rates in Turkey.

    Science.gov (United States)

    Keser, Saniye; Duzgun, Sebnem; Aksoy, Aysegul

    2012-03-01

    In studies focusing on the factors that impact solid waste generation habits and rates, the potential spatial dependency in solid waste generation data is not considered in relating the waste generation rates to its determinants. In this study, spatial dependency is taken into account in determination of the significant socio-economic and climatic factors that may be of importance for the municipal solid waste (MSW) generation rates in different provinces of Turkey. Simultaneous spatial autoregression (SAR) and geographically weighted regression (GWR) models are used for the spatial data analyses. Similar to ordinary least squares regression (OLSR), regression coefficients are global in SAR model. In other words, the effect of a given independent variable on a dependent variable is valid for the whole country. Unlike OLSR or SAR, GWR reveals the local impact of a given factor (or independent variable) on the waste generation rates of different provinces. Results show that provinces within closer neighborhoods have similar MSW generation rates. On the other hand, this spatial autocorrelation is not very high for the exploratory variables considered in the study. OLSR and SAR models have similar regression coefficients. GWR is useful to indicate the local determinants of MSW generation rates. GWR model can be utilized to plan waste management activities at local scale including waste minimization, collection, treatment, and disposal. At global scale, the MSW generation rates in Turkey are significantly related to unemployment rate and asphalt-paved roads ratio. Yet, significances of these variables may diminish at local scale for some provinces. At local scale, different factors may be important in affecting MSW generation rates. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Spatial Analysis of Accident Spots Using Weighted Severity Index ...

    African Journals Online (AJOL)

    Weighted Severity Index (WSI) was created based on these factors/drivers. Also, Density-based Clustering for Traffic Accident Risk (DBCTAR) was carried out to assist in ascertaining the distribution of Black Spots Severity (BSS). Results obtained include: shortestpath analysis, service area analysis, accident spot severity ...

  2. [A spatially explicit analysis of traffic accidents involving pedestrians and cyclists in Berlin].

    Science.gov (United States)

    Lakes, Tobia

    2017-12-01

    In many German cities and counties, sustainable mobility concepts that strengthen pedestrian and cyclist traffic are promoted. From the perspectives of urban development, traffic planning and public healthcare, a spatially differentiated analysis of traffic accident data is decisive. 1) The identification of spatial and temporal patterns of the distribution of accidents involving cyclists and pedestrians, 2) the identification of hotspots and exploration of possible underlying causes and 3) the critical discussion of benefits and challenges of the results and the derivation of conclusions. Spatio-temporal distributions of data from accident statistics in Berlin involving pedestrians and cyclists from 2011 to 2015 were analysed with geographic information systems (GIS). While the total number of accidents remains relatively stable for pedestrian and cyclist accidents, the spatial distribution analysis shows, however, that there are significant spatial clusters (hotspots) of traffic accidents with a strong concentration in the inner city area. In a critical discussion, the benefits of geographic concepts are identified, such as spatially explicit health data (in this case traffic accident data), the importance of the integration of other data sources for the evaluation of the health impact of areas (traffic accident statistics of the police), and the possibilities and limitations of spatial-temporal data analysis (spatial point-density analyses) for the derivation of decision-supported recommendations and for the evaluation of policy measures of health prevention and of health-relevant urban development.

  3. GALA: group analysis leads to accuracy, a novel approach for solving the inverse problem in exploratory analysis of group MEG recordings.

    Science.gov (United States)

    Kozunov, Vladimir V; Ossadtchi, Alexei

    2015-01-01

    Although MEG/EEG signals are highly variable between subjects, they allow characterizing systematic changes of cortical activity in both space and time. Traditionally a two-step procedure is used. The first step is a transition from sensor to source space by the means of solving an ill-posed inverse problem for each subject individually. The second is mapping of cortical regions consistently active across subjects. In practice the first step often leads to a set of active cortical regions whose location and timecourses display a great amount of interindividual variability hindering the subsequent group analysis. We propose Group Analysis Leads to Accuracy (GALA)-a solution that combines the two steps into one. GALA takes advantage of individual variations of cortical geometry and sensor locations. It exploits the ensuing variability in electromagnetic forward model as a source of additional information. We assume that for different subjects functionally identical cortical regions are located in close proximity and partially overlap and their timecourses are correlated. This relaxed similarity constraint on the inverse solution can be expressed within a probabilistic framework, allowing for an iterative algorithm solving the inverse problem jointly for all subjects. A systematic simulation study showed that GALA, as compared with the standard min-norm approach, improves accuracy of true activity recovery, when accuracy is assessed both in terms of spatial proximity of the estimated and true activations and correct specification of spatial extent of the activated regions. This improvement obtained without using any noise normalization techniques for both solutions, preserved for a wide range of between-subject variations in both spatial and temporal features of regional activation. The corresponding activation timecourses exhibit significantly higher similarity across subjects. Similar results were obtained for a real MEG dataset of face-specific evoked responses.

  4. GALA: Group Analysis Leads to Accuracy, a novel approach for solving the inverse problem in exploratory analysis of group MEG recordings

    Directory of Open Access Journals (Sweden)

    Vladimir eKozunov

    2015-04-01

    Full Text Available Although MEG/EEG signals are highly variable between subjects, they allow characterizing systematic changes of cortical activity in both space and time. Traditionally a two-step procedure is used. The first step is a transition from sensor to source space by the means of solving an ill-posed inverse problem for each subject individually. The second is mapping of cortical regions consistently active across subjects. In practice the first step often leads to a set of active cortical regions whose location and timecourses display a great amount of interindividual variability hindering the subsequent group analysis.We propose Group Analysis Leads to Accuracy (GALA - a solution that combines the two steps into one. GALA takes advantage of individual variations of cortical geometry and sensor locations. It exploits the ensuing variability in electromagnetic forward model as a source of additional information. We assume that for different subjects functionally identical cortical regions are located in close proximity and partially overlap and their timecourses are correlated. This relaxed similarity constraint on the inverse solution can be expressed within a probabilistic framework, allowing for an iterative algorithm solving the inverse problem jointly for all subjects.A systematic simulation study showed that GALA, as compared with the standard min-norm approach, improves accuracy of true activity recovery, when accuracy is assessed both in terms of spatial proximity of the estimated and true activations and correct specification of spatial extent of the activated regions. This improvement obtained without using any noise normalization techniques for both solutions, preserved for a wide range of between-subject variations in both spatial and temporal features of regional activation. The corresponding activation timecourses exhibit significantly higher similarity across subjects. Similar results were obtained for a real MEG dataset of face

  5. Abundant Topological Outliers in Social Media Data and Their Effect on Spatial Analysis.

    Science.gov (United States)

    Westerholt, Rene; Steiger, Enrico; Resch, Bernd; Zipf, Alexander

    2016-01-01

    Twitter and related social media feeds have become valuable data sources to many fields of research. Numerous researchers have thereby used social media posts for spatial analysis, since many of them contain explicit geographic locations. However, despite its widespread use within applied research, a thorough understanding of the underlying spatial characteristics of these data is still lacking. In this paper, we investigate how topological outliers influence the outcomes of spatial analyses of social media data. These outliers appear when different users contribute heterogeneous information about different phenomena simultaneously from similar locations. As a consequence, various messages representing different spatial phenomena are captured closely to each other, and are at risk to be falsely related in a spatial analysis. Our results reveal indications for corresponding spurious effects when analyzing Twitter data. Further, we show how the outliers distort the range of outcomes of spatial analysis methods. This has significant influence on the power of spatial inferential techniques, and, more generally, on the validity and interpretability of spatial analysis results. We further investigate how the issues caused by topological outliers are composed in detail. We unveil that multiple disturbing effects are acting simultaneously and that these are related to the geographic scales of the involved overlapping patterns. Our results show that at some scale configurations, the disturbances added through overlap are more severe than at others. Further, their behavior turns into a volatile and almost chaotic fluctuation when the scales of the involved patterns become too different. Overall, our results highlight the critical importance of thoroughly considering the specific characteristics of social media data when analyzing them spatially.

  6. Infant mortality in Brazil, 1980-2000: A spatial panel data analysis

    Directory of Open Access Journals (Sweden)

    Barufi Ana

    2012-03-01

    Full Text Available Abstract Background Infant mortality is an important measure of human development, related to the level of welfare of a society. In order to inform public policy, various studies have tried to identify the factors that influence, at an aggregated level, infant mortality. The objective of this paper is to analyze the regional pattern of infant mortality in Brazil, evaluating the effect of infrastructure, socio-economic, and demographic variables to understand its distribution across the country. Methods Regressions including socio-economic and living conditions variables are conducted in a structure of panel data. More specifically, a spatial panel data model with fixed effects and a spatial error autocorrelation structure is used to help to solve spatial dependence problems. The use of a spatial modeling approach takes into account the potential presence of spillovers between neighboring spatial units. The spatial units considered are Minimum Comparable Areas, defined to provide a consistent definition across Census years. Data are drawn from the 1980, 1991 and 2000 Census of Brazil, and from data collected by the Ministry of Health (DATASUS. In order to identify the influence of health care infrastructure, variables related to the number of public and private hospitals are included. Results The results indicate that the panel model with spatial effects provides the best fit to the data. The analysis confirms that the provision of health care infrastructure and social policy measures (e.g. improving education attainment are linked to reduced rates of infant mortality. An original finding concerns the role of spatial effects in the analysis of IMR. Spillover effects associated with health infrastructure and water and sanitation facilities imply that there are regional benefits beyond the unit of analysis. Conclusions A spatial modeling approach is important to produce reliable estimates in the analysis of panel IMR data. Substantively, this paper

  7. Comparative analysis of elements and models of implementation in local-level spatial plans in Serbia

    Directory of Open Access Journals (Sweden)

    Stefanović Nebojša

    2017-01-01

    Full Text Available Implementation of local-level spatial plans is of paramount importance to the development of the local community. This paper aims to demonstrate the importance of and offer further directions for research into the implementation of spatial plans by presenting the results of a study on models of implementation. The paper describes the basic theoretical postulates of a model for implementing spatial plans. A comparative analysis of the application of elements and models of implementation of plans in practice was conducted based on the spatial plans for the local municipalities of Arilje, Lazarevac and Sremska Mitrovica. The analysis includes four models of implementation: the strategy and policy of spatial development; spatial protection; the implementation of planning solutions of a technical nature; and the implementation of rules of use, arrangement and construction of spaces. The main results of the analysis are presented and used to give recommendations for improving the elements and models of implementation. Final deliberations show that models of implementation are generally used in practice and combined in spatial plans. Based on the analysis of how models of implementation are applied in practice, a general conclusion concerning the complex character of the local level of planning is presented and elaborated. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 36035: Spatial, Environmental, Energy and Social Aspects of Developing Settlements and Climate Change - Mutual Impacts and Grant no. III 47014: The Role and Implementation of the National Spatial Plan and Regional Development Documents in Renewal of Strategic Research, Thinking and Governance in Serbia

  8. Violence, drug markets and racial composition: challenging stereotypes through spatial analysis.

    Science.gov (United States)

    Lum, Cynthia

    2011-01-01

    Places in which there is a strong spatial connection between violence and drug activity can often evoke particular stereotypes. They are believed to be places marked by high levels of social disorganisation, unemployment, disorder and racial heterogeneity. Yet scholars have argued that the spatial relationship between drug market activity and violence is more complicated and that other factors may explain this geographical connection. In the first article of this two-part series, different types of spatial analysis were employed to describe crime concentrations of drugs and violence. Evidence was found that challenges the notion that places with drug activity are inevitably more violent. This second paper examines what factors predict these variations in drug–violence spatial patterns in Seattle when derived using different spatial methods. The findings indicate that racial composition, disorder and unemployment may not be as salient as once believed in predicting places that are violent drug markets.

  9. Spatial analysis of crime incidence and adolescent physical activity.

    Science.gov (United States)

    Robinson, Alyssa I; Carnes, Fei; Oreskovic, Nicolas M

    2016-04-01

    Adolescents do not achieve recommended levels of physical activity. Crime is believed to be a barrier to physical activity among youth, but findings are inconsistent. This study compares the spatial distribution of crime incidences and moderate-to-vigorous physical activity (MVPA) among adolescents in Massachusetts between 2011 and 2012, and examines the correlation between crime and MVPA. Eighty adolescents provided objective physical activity (accelerometer) and location (Global Positioning Systems) data. Crime report data were obtained from the city police department. Data were mapped using geographic information systems, and crime and MVPA densities were calculated using kernel density estimations. Spearman's correlation tested for associations between crime and MVPA. Overall, 1694 reported crimes and 16,702min of MVPA were included in analyses. A strong positive correlation was present between crime and adolescent MVPA (ρ=0.72, pCrime remained positively associated with MVPA in locations falling within the lowest quartile (ρ=0.43, pcrime density. This study found a strong positive association between crime and adolescent MVPA, despite research suggesting the opposite relationship. This counterintuitive finding may be explained by the logic of a common destination: neighborhood spaces which are desirable destinations and promote physical activity may likewise attract crime. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Spatial and temporal analysis of lake sedimentation under reforestation

    Directory of Open Access Journals (Sweden)

    C.M. Pilgrim

    2015-10-01

    Full Text Available Spatial and temporal land cover changes can reduce or accelerate lake sedimentation. This study was conducted to examine morphometry and bathymetry, and the long-term changes (over 75 years in sedimentation in the Lake Issaqueena reservoir, South Carolina. The watershed and catchment areas were delineated using Light Detection and Ranging (LiDAR based data. Trends in lake surface area and riparian buffer condition (vegetated or unvegetated were determined from historical aerial photography. From 1938 to 2009, the lake experienced a decrease in surface area of approximately 11.33 ha while catchment area increased by 6.99 ha, and lake volume decreased by 320,800.00 m3. Lake surface area decreased in years corresponding to equal coverage or largely unvegetated riparian buffers. Surface area and average annual precipitation were not correlated; therefore other factors such as soil type, riparian buffer condition and changes in land use likely contributed to sedimentation. Shift from agricultural land to forestland in this watershed resulted in a decrease in sedimentation rates by 88.28%.

  11. Spatially Resolved Spectral Powder Analysis: Experiments and Modeling.

    Science.gov (United States)

    Scheibelhofer, Otto; Wahl, Patrick R; Larchevêque, Boris; Chauchard, Fabien; Khinast, Johannes G

    2018-01-01

    Understanding the behavior of light in granular media is necessary for determining the sample size, shape, and weight when probing using fiber optic setups. This is required for a correct estimate of the active pharmaceutical ingredient content in a pharmaceutical blend via near-infrared spectroscopy. Several strategies to describe the behavior of light in granular and turbid media exist. A common approach is the Monte-Carlo simulation of individual photons and their description using mean free path lengths for scattering and absorption. In this work, we chose a complementary method by approximating these parameters via real physical counterparts, i.e., the particle size, shape, and density and the resulting chord lengths. Additionally, the wavelength dependence of refractive indices is incorporated. The obtained results were compared with those obtained in an experimental setup that included the SAM-Spec Felin probe head by Indatech for detecting spatially resolved spectra of samples. Our method facilitates the interpretation of the acquired experimental results by contrasting the optical response, the physical particle attributes, and the simulation results.

  12. Evaluation of classical spatial-analysis schemes of extreme rainfall

    Directory of Open Access Journals (Sweden)

    D. Ceresetti

    2012-11-01

    Full Text Available Extreme rainfall is classically estimated using raingauge data at raingauge locations. An important related issue is to assess return levels of extreme rainfall at ungauged sites. Classical methods consist in interpolating extreme-value models. In this paper, such methods are referred to as regionalization schemes. Our goal is to evaluate three classical regionalization schemes. Each scheme consists of an extreme-value model (block maxima, peaks over threshold taken from extreme-value theory plus a method to interpolate the parameters of the statistical model throughout the Cévennes-Vivarais region. From the interpolated parameters, the 100-yr quantile level can be estimated over this whole region. A reference regionalization scheme is made of the couple block maxima/kriging, where kriging is an optimal interpolation method. The two other schemes differ from the reference by replacing either the extreme-value model block maxima by peaks over threshold or kriging by a neural network interpolation procedure. Hyper-parameters are selected by cross-validation and the three regionalization schemes are compared by double cross-validation. Our evaluation criteria are based on the ability to interpolate the 100-yr return level both in terms of precision and spatial distribution. It turns out that the best results are obtained by the regionalization scheme combining the peaks-over-threshold method with kriging.

  13. Problems in implementation of the spatial plan of the Republic of Srpska until 2015: Quantitative analysis

    Directory of Open Access Journals (Sweden)

    Bijelić Branislav

    2017-01-01

    Full Text Available The implementation of spatial plans in the Republic of Srpska is certainly the weakest phase of the process of spatial planning in this entity. It is particularly evident in the case of the Spatial Plan of the Republic of Srpska until 2015 which is the highest strategic spatial planning document in the Republic of Srpska. More precisely, the implementation of spatial plans has been defined as the carrying out of spatial planning documents, i.e. planning propositions as defined in the spatial plans. For the purpose of this paper, a quantitative analysis of the implementation of the planning propositions envisioned by this document has been carried out. The difference between what was planned and what was implemented at the end of the planning period (ex-post evaluation of planning decisions is presented in this paper. The weighting factor is defined for each thematic field and planning proposition, where the main criterion for determining the weighting factor is the share of the planning proposition and thematic field in the estimated total costs of the plan (financial criterion. The paper has also tackled the issue of the implementation of the Spatial Plan of Bosnia and Herzegovina for the period 1981 - 2000, as well as of the Spatial Plan of the Republic of Srpska 1996 - 2001 - Phased Plan for the period 1996 - 2001, as the previous strategic spatial planning documents of the highest rank covering the area of the Republic of Srpska. The research results have proven primary hypothesis of the paper that the level of the implementation of Spatial Plan of the Republic of Srpska until 2015 is less than 10%.

  14. Semi-supervised Spatial-spectral Discriminant Analysis for Hyperspectral Image Classification

    Directory of Open Access Journals (Sweden)

    HOU Banghuan

    2017-09-01

    Full Text Available In order to make full use of the spatial information embedded in the hyperspectral image to improve the classification accuracy, a semi-supervised spatial-spectral discriminant analysis (S3DA algorithm for hyperspectral image classification is proposed. According to the spatial consistency property of hyperspectral image, the intra-class scatter matrix infered from a little labeled samples preserves the spectral similarity of the same class pixels, while the spatial local pixel scatter matrix defined by the unlabeled spatial neighbors uncovers the spatial-domain local pixel neighborhood structures and the ground objects detailed distribution. The S3DA method not only maintains the spectral-domain separability of the data set, but also preserves the spatial-domain local pixel neighborhood structure, which promotes the compactness of the same class pixels or the spatial neighbor pixels in the projected subspace and enhances the classification performance. The overall classification accuracies respectively reach 81.50% and 71.77% on the PaviaU and Indian Pines data sets. Compared with the traditional spectral methods, the proposed method can effectively improve ground objects classification accuracy.

  15. Environmental Risk Assessment: Spatial Analysis of Chemical Hazards and Risks in South Korea

    Science.gov (United States)

    Yu, H.; Heo, S.; Kim, M.; Lee, W. K.; Jong-Ryeul, S.

    2017-12-01

    This study identified chemical hazard and risk levels in Korea by analyzing the spatial distribution of chemical factories and accidents. The number of chemical factories and accidents in 5-km2 grids were used as the attribute value for spatial analysis. First, semi-variograms were conducted to examine spatial distribution patterns and to identify spatial autocorrelation of chemical factories and accidents. Semi-variograms explained that the spatial distribution of chemical factories and accidents were spatially autocorrelated. Second, the results of the semi-variograms were used in Ordinary Kriging to estimate chemical hazard and risk level. The level values were extracted from the Ordinary Kriging result and their spatial similarity was examined by juxtaposing the two values with respect to their location. Six peaks were identified in both the hazard and risk estimation result, and the peaks correlated with major cities in Korea. Third, the estimated hazard and risk levels were classified with geometrical interval and could be classified into four quadrants: Low Hazard and Low Risk (LHLR), Low Hazard and High Risk (LHHR), High Hazard and Low Risk (HHLR), and High Hazard and High Risk (HHHR). The 4 groups identified different chemical safety management issues in Korea; relatively safe LHLR group, many chemical reseller factories were found in HHLR group, chemical transportation accidents were in the LHHR group, and an abundance of factories and accidents were in the HHHR group. Each quadrant represented different safety management obstacles in Korea, and studying spatial differences can support the establishment of an efficient risk management plan.

  16. Structural and chemical analysis of materials with high spatial resolution

    International Nuclear Information System (INIS)

    Benthem, K. van; Kraemer, S.; Sigle, W.; Ruehle, M.

    2002-01-01

    An understanding of the correlation between microstructures and properties of materials require the characterization of the material on many different length scales. Often the properties depend primarily on the atomistics of defects, such as dislocations and interfaces. The different techniques of transmission electron microscopy allow the characterization of the structure and of the chemical composition of materials with high spatial resolution to the atomic level: high resolution transmission electron microscopy allows the determination of the position of the columns of atoms (ions) with high accuracy. The accuracy which can be achieved in these measurements depends not only on the instrumentation but also on the quality of the transmitted specimen and on the scattering power of the atoms (ions) present in the analyzed column. The chemical composition can be revealed from investigations by analytical microscopy which includes energy dispersive x-ray spectroscopy, mainly quantitatively applied for heavy elements, and electron energy-loss spectroscopy. Furthermore, the energy-loss near-edge structure of EELS data results in information on the local band structure of unoccupied states of the excited atoms and, therefore, on bonding. A quantitative evaluation of convergent beam electron diffraction results in information on the electron charge density distribution of the bulk (defect-free) material. The different techniques are described and applied to different problems in materials science. lt will be shown that nearly atomic resolution can be achieved in high resolution electron microscopy and in analytical electron microscopy. Recent developments in electron microscopy instrumentation will result in atomic resolution in the foreseeable future. (author)

  17. What works best for whom? An exploratory, subgroup analysis in a randomized, controlled trial on the effectiveness of a workplace intervention in low back pain patients on return to work

    NARCIS (Netherlands)

    Steenstra, I.A.; Knol, D.L.; Bongers, P.M.; Anema, J.R.; Mechelen, W. van; Vet, H.C.W. de

    2009-01-01

    STUDY DESIGN. Exploratory subgroup analysis in a randomized controlled trial (RCT). OBJECTIVE. To detect possible moderators in the effectiveness of a workplace intervention in a population of workers with sick leave due to sub acute nonspecific low back pain. SUMMARY OF BACKGROUND DATA. In a

  18. Determinants of the distribution and concentration of biogas production in Germany. A spatial econometric analysis

    International Nuclear Information System (INIS)

    Scholz, Lukas

    2015-01-01

    The biogas production in Germany is characterized by a heterogeneous distribution and the formation of regional centers. In the present study the determinants of the spatial distribution and concentration are analyzed with methods of spatial statistics and spatial econometrics. In addition to the consideration of ''classic'' site factors of agricultural production, the analysis here focuses on the possible relevance of agglomeration effects. The results of the work contribute to a better understanding of the regional distribution and concentration of the biogas production in Germany. [de

  19. Statistical analysis of long term spatial and temporal trends of ...

    Indian Academy of Sciences (India)

    The annual and seasonal trend analysis of different surface temperature parameters (average, maximum, minimum and diurnal temperature range) has been done for historical (1971–2005) and future periods (2011–2099) in the middle catchment of Sutlej river basin, India. The future time series of temperature data has ...

  20. Spatial Analysis of Soil Fertility Using Geographical Information ...

    African Journals Online (AJOL)

    The research evaluated soil fertility condition of River Otamiri watershed in southeastern Nigeria in relation to topographic heterogeneity using GIS technique. GPS was used to determine the geodetic coordinate of the sampling points and site elevation. Soil samples were collected and analyzed using standard soil analysis ...