Taking the Next Step: Combining Incrementally Valid Indicators to Improve Recidivism Prediction
ERIC Educational Resources Information Center
Walters, Glenn D.
2011-01-01
The possibility of combining indicators to improve recidivism prediction was evaluated in a sample of released federal prisoners randomly divided into a derivation subsample (n = 550) and a cross-validation subsample (n = 551). Five incrementally valid indicators were selected from five domains: demographic (age), historical (prior convictions),…
40 CFR 761.355 - Third level of sample selection.
Code of Federal Regulations, 2012 CFR
2012-07-01
... of sample selection further reduces the size of the subsample to 100 grams which is suitable for the... procedures in § 761.353 of this part into 100 gram portions. (b) Use a random number generator or random number table to select one 100 gram size portion as a sample for a procedure used to simulate leachate...
40 CFR 761.355 - Third level of sample selection.
Code of Federal Regulations, 2011 CFR
2011-07-01
... of sample selection further reduces the size of the subsample to 100 grams which is suitable for the... procedures in § 761.353 of this part into 100 gram portions. (b) Use a random number generator or random number table to select one 100 gram size portion as a sample for a procedure used to simulate leachate...
40 CFR 761.355 - Third level of sample selection.
Code of Federal Regulations, 2013 CFR
2013-07-01
... of sample selection further reduces the size of the subsample to 100 grams which is suitable for the... procedures in § 761.353 of this part into 100 gram portions. (b) Use a random number generator or random number table to select one 100 gram size portion as a sample for a procedure used to simulate leachate...
40 CFR 761.355 - Third level of sample selection.
Code of Federal Regulations, 2010 CFR
2010-07-01
... of sample selection further reduces the size of the subsample to 100 grams which is suitable for the... procedures in § 761.353 of this part into 100 gram portions. (b) Use a random number generator or random number table to select one 100 gram size portion as a sample for a procedure used to simulate leachate...
40 CFR 761.355 - Third level of sample selection.
Code of Federal Regulations, 2014 CFR
2014-07-01
... of sample selection further reduces the size of the subsample to 100 grams which is suitable for the... procedures in § 761.353 of this part into 100 gram portions. (b) Use a random number generator or random number table to select one 100 gram size portion as a sample for a procedure used to simulate leachate...
Prediction of postoperative pulmonary complications in a population-based surgical cohort.
Canet, Jaume; Gallart, Lluís; Gomar, Carmen; Paluzie, Guillem; Vallès, Jordi; Castillo, Jordi; Sabaté, Sergi; Mazo, Valentín; Briones, Zahara; Sanchis, Joaquín
2010-12-01
Current knowledge of the risk for postoperative pulmonary complications (PPCs) rests on studies that narrowly selected patients and procedures. Hypothesizing that PPC occurrence could be predicted from a reduced set of perioperative variables, we aimed to develop a predictive index for a broad surgical population. Patients undergoing surgical procedures given general, neuraxial, or regional anesthesia in 59 hospitals were randomly selected for this prospective, multicenter study. The main outcome was the development of at least one of the following: respiratory infection, respiratory failure, bronchospasm, atelectasis, pleural effusion, pneumothorax, or aspiration pneumonitis. The cohort was randomly divided into a development subsample to construct a logistic regression model and a validation subsample. A PPC predictive index was constructed. Of 2,464 patients studied, 252 events were observed in 123 (5%). Thirty-day mortality was higher in patients with a PPC (19.5%; 95% [CI], 12.5-26.5%) than in those without a PPC (0.5%; 95% CI, 0.2-0.8%). Regression modeling identified seven independent risk factors: low preoperative arterial oxygen saturation, acute respiratory infection during the previous month, age, preoperative anemia, upper abdominal or intrathoracic surgery, surgical duration of at least 2 h, and emergency surgery. The area under the receiver operating characteristic curve was 90% (95% CI, 85-94%) for the development subsample and 88% (95% CI, 84-93%) for the validation subsample. The risk index based on seven objective, easily assessed factors has excellent discriminative ability. The index can be used to assess individual risk of PPC and focus further research on measures to improve patient care.
Davids, Jeffrey C; van de Giesen, Nick; Rutten, Martine
2017-07-01
Hydrologic data has traditionally been collected with permanent installations of sophisticated and accurate but expensive monitoring equipment at limited numbers of sites. Consequently, observation frequency and costs are high, but spatial coverage of the data is limited. Citizen Hydrology can possibly overcome these challenges by leveraging easily scaled mobile technology and local residents to collect hydrologic data at many sites. However, understanding of how decreased observational frequency impacts the accuracy of key streamflow statistics such as minimum flow, maximum flow, and runoff is limited. To evaluate this impact, we randomly selected 50 active United States Geological Survey streamflow gauges in California. We used 7 years of historical 15-min flow data from 2008 to 2014 to develop minimum flow, maximum flow, and runoff values for each gauge. To mimic lower frequency Citizen Hydrology observations, we developed a bootstrap randomized subsampling with replacement procedure. We calculated the same statistics, and their respective distributions, from 50 subsample iterations with four different subsampling frequencies ranging from daily to monthly. Minimum flows were estimated within 10% for half of the subsample iterations at 39 (daily) and 23 (monthly) of the 50 sites. However, maximum flows were estimated within 10% at only 7 (daily) and 0 (monthly) sites. Runoff volumes were estimated within 10% for half of the iterations at 44 (daily) and 12 (monthly) sites. Watershed flashiness most strongly impacted accuracy of minimum flow, maximum flow, and runoff estimates from subsampled data. Depending on the questions being asked, lower frequency Citizen Hydrology observations can provide useful hydrologic information.
Strategic Use of Random Subsample Replication and a Coefficient of Factor Replicability
ERIC Educational Resources Information Center
Katzenmeyer, William G.; Stenner, A. Jackson
1975-01-01
The problem of demonstrating replicability of factor structure across random variables is addressed. Procedures are outlined which combine the use of random subsample replication strategies with the correlations between factor score estimates across replicate pairs to generate a coefficient of replicability and confidence intervals associated with…
A sub-sampled approach to extremely low-dose STEM
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stevens, A.; Luzi, L.; Yang, H.
The inpainting of randomly sub-sampled images acquired by scanning transmission electron microscopy (STEM) is an attractive method for imaging under low-dose conditions (≤ 1 e -Å 2) without changing either the operation of the microscope or the physics of the imaging process. We show that 1) adaptive sub-sampling increases acquisition speed, resolution, and sensitivity; and 2) random (non-adaptive) sub-sampling is equivalent, but faster than, traditional low-dose techniques. Adaptive sub-sampling opens numerous possibilities for the analysis of beam sensitive materials and in-situ dynamic processes at the resolution limit of the aberration corrected microscope and is demonstrated here for the analysis ofmore » the node distribution in metal-organic frameworks (MOFs).« less
Structural Relations among Spirituality, Religiosity, and Thriving in Adolescence
ERIC Educational Resources Information Center
Dowling, Elizabeth M.; Gestsdottir, Steinunn; Anderson, Pamela M.; Von Eye, Alexander; Almerigi, Jason; Lerner, Richard M.
2004-01-01
Using the randomly selected subsample of 1,000 youth (472 boys, M age = 12.2 years, SD = 1.5; 528 girls, M age = 12.1 years, SD = 1.4) drawn by Dowling, Getsdottir, Anderson, von Eye, and Lerner (in press) from a Search Institute (1984) archival data set, Young Adolescents and Their Parents (YAP), this research employed structural equation…
JoAnn M. Hanowski; Gerald J. Niemi
1995-01-01
We established bird monitoring programs in two regions of Minnesota: the Chippewa National Forest and the Superior National Forest. The experimental design defined forest cover types as strata in which samples of forest stands were randomly selected. Subsamples (3 point counts) were placed in each stand to maximize field effort and to assess within-stand and between-...
Guided transect sampling - a new design combining prior information and field surveying
Anna Ringvall; Goran Stahl; Tomas Lamas
2000-01-01
Guided transect sampling is a two-stage sampling design in which prior information is used to guide the field survey in the second stage. In the first stage, broad strips are randomly selected and divided into grid-cells. For each cell a covariate value is estimated from remote sensing data, for example. The covariate is the basis for subsampling of a transect through...
Kärkkäinen, Matti K; Tuppurainen, Marjo; Salovaara, Kari; Sandini, Lorenzo; Rikkonen, Toni; Sirola, Joonas; Honkanen, Risto; Arokoski, Jari; Alhava, Esko; Kröger, Heikki
2010-04-01
The hypothesis was that the calcium and vitamin D supplementation prevents falls at the population level. The OSTPRE-FPS was a randomized population-based open-trial with 3-year follow-up. The supplementation group (n=1566) received daily cholecalciferol 800IU+calcium carbonate 1000mg, while the control group (n=1573) received no supplementation or placebo. A randomly selected subsample of 593 subjects underwent a detailed measurement program including serum 25(OH)D measurements. The occurrence of falls was the primary outcome of the study. The participants in the subsample were telephoned at 4 months intervals and the rest of the trial population was interviewed by phone once a year. In the entire trial population (ETP), there were 812 women with 1832 falls in the intervention group and 833 women with 1944 falls in the control group (risk ratio was 0.98, 95% CI 0.92-1.05, P=0.160). The supplementation was not associated with single or multiple falls in the ETP. However, in the subsample, multiple fall incidence decreased by 30% (odds ratio (OR) 0.70, 95% CI 0.50-0.97, P=0.034) in the supplementation group. Further, the supplementation decreased the incidence of multiple falls requiring medical attention (OR 0.72, 95% CI 0.53-0.97, P=0.031) in the ETP. The mean compliance in the entire trial population was 78% and in the subsample 79%. Overall, the primary analysis showed no association between calcium and vitamin D supplementation and risk of falls. However, the results of a post hoc analysis suggested that there was a decreased risk of multiple falls requiring medical attention: this finding requires confirmation. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Davids, J. C.; Rutten, M.; Van De Giesen, N.
2016-12-01
Hydrologic data has traditionally been collected with permanent installations of sophisticated and relatively accurate but expensive monitoring equipment at limited numbers of sites. Consequently, the spatial coverage of the data is limited and costs are high. Achieving adequate maintenance of sophisticated monitoring equipment often exceeds local technical and resource capacity, and permanently deployed monitoring equipment is susceptible to vandalism, theft, and other hazards. Rather than using expensive, vulnerable installations at a few points, SmartPhones4Water (S4W), a form of Citizen Hydrology, leverages widely available mobile technology to gather hydrologic data at many sites in a manner that is repeatable and scalable. However, there is currently a limited understanding of the impact of decreased observational frequency on the accuracy of key streamflow statistics like minimum flow, maximum flow, and runoff. As a first step towards evaluating the tradeoffs between traditional continuous monitoring approaches and emerging Citizen Hydrology methods, we randomly selected 50 active U.S. Geological Survey (USGS) streamflow gauges in California. We used historical 15 minute flow data from 01/01/2008 through 12/31/2014 to develop minimum flow, maximum flow, and runoff values (7 year total) for each gauge. In order to mimic lower frequency Citizen Hydrology observations, we developed a bootstrap randomized subsampling with replacement procedure. We calculated the same statistics, along with their respective distributions, from 50 subsample iterations with four different subsampling intervals (i.e. daily, three day, weekly, and monthly). Based on our results we conclude that, depending on the types of questions being asked, and the watershed characteristics, Citizen Hydrology streamflow measurements can provide useful and accurate information. Depending on watershed characteristics, minimum flows were reasonably estimated with subsample intervals ranging from daily to monthly. However, maximum flows in most cases were poorly characterized, even at daily subsample intervals. In general, runoff volumes were accurately estimated from daily, three day, weekly, and even in some cases, monthly observations.
Integrating SAS and GIS software to improve habitat-use estimates from radiotelemetry data
Kenow, K.P.; Wright, R.G.; Samuel, M.D.; Rasmussen, P.W.
2001-01-01
Radiotelemetry has been used commonly to remotely determine habitat use by a variety of wildlife species. However, habitat misclassification can occur because the true location of a radiomarked animal can only be estimated. Analytical methods that provide improved estimates of habitat use from radiotelemetry location data using a subsampling approach have been proposed previously. We developed software, based on these methods, to conduct improved habitat-use analyses. A Statistical Analysis System (SAS)-executable file generates a random subsample of points from the error distribution of an estimated animal location and formats the output into ARC/INFO-compatible coordinate and attribute files. An associated ARC/INFO Arc Macro Language (AML) creates a coverage of the random points, determines the habitat type at each random point from an existing habitat coverage, sums the number of subsample points by habitat type for each location, and outputs tile results in ASCII format. The proportion and precision of habitat types used is calculated from the subsample of points generated for each radiotelemetry location. We illustrate the method and software by analysis of radiotelemetry data for a female wild turkey (Meleagris gallopavo).
Pingault, Jean-Baptiste; Falissard, Bruno; Côté, Sylvana; Berthoz, Sylvie
2012-01-01
Background The Affective Neuroscience Personality Scales (ANPS) is an instrument designed to assess endophenotypes related to activity in the core emotional systems that have emerged from affective neuroscience research. It operationalizes six emotional endophenotypes with empirical evidence derived from ethology, neural analyses and pharmacology: PLAYFULNESS/joy, SEEKING/interest, CARING/nurturance, ANGER/rage, FEAR/anxiety, and SADNESS/separation distress. We aimed to provide a short version of this questionnaire (ANPS-S). Methodology/Principal Findings We used a sample of 830 young French adults which was randomly split into two subsamples. The first subsample was used to select the items for the short scales. The second subsample and an additional sample of 431 Canadian adults served to evaluate the psychometric properties of the short instrument. The ANPS-S was similar to the long version regarding intercorrelations between the scales and gender differences. The ANPS-S had satisfactory psychometric properties, including factorial structure, unidimensionality of all scales, and internal consistency. The scores from the short version were highly correlated with the scores from the long version. Conclusions/Significance The short ANPS proves to be a promising instrument to assess endophenotypes for psychiatrically relevant science. PMID:22848510
Bronikowski, Michal; Bronikowska, Malgorzata
2011-11-01
In this paper we evaluate the sustainability of changes of involvement in physical activity. The paper examines the effectiveness of a model aiming at influencing the frequency of leisure time physical activity, physical fitness and body constituency in youth. The baseline of this study was a randomly selected sample of 13 year olds who participated in an intervention programme carried out in three schools in Poznan in 2005-08. From a total of 199 adolescent boys a subsample of 38 individuals from the experimental group and 34 from the control group were followed for 15 months after the interventional programme finished. From 170 girls, a subsample of 33 from the experimental group and 32 girls from the control group were also randomly selected for the follow-up study. Among the variables monitored were: physical fitness, body constituency, and frequency of leisure time physical activity. All the variables were monitored in pre-test, post-test and follow-up examinations. It was established that 15 months after the end of the interventional programme boys and girls from the intervention groups maintained a higher level of leisure time physical activity than their control group peers, and similarly in the case of selected health-related components of physical fitness. No distinctive differences were found in the case of body constituency, though, apart from muscle mass and the sum of skinfolds in girls. The study exposed an increase in leisure time physical activity in time and a positive influence on selected components of health-related variables. The findings confirm the effectiveness of a multi-level intervention programme involving self-determined out-of-school physical activity planning for school-age youths, indicating the importance of personal and social context.
Attenuation of species abundance distributions by sampling
Shimadzu, Hideyasu; Darnell, Ross
2015-01-01
Quantifying biodiversity aspects such as species presence/ absence, richness and abundance is an important challenge to answer scientific and resource management questions. In practice, biodiversity can only be assessed from biological material taken by surveys, a difficult task given limited time and resources. A type of random sampling, or often called sub-sampling, is a commonly used technique to reduce the amount of time and effort for investigating large quantities of biological samples. However, it is not immediately clear how (sub-)sampling affects the estimate of biodiversity aspects from a quantitative perspective. This paper specifies the effect of (sub-)sampling as attenuation of the species abundance distribution (SAD), and articulates how the sampling bias is induced to the SAD by random sampling. The framework presented also reveals some confusion in previous theoretical studies. PMID:26064626
Regional flood-frequency relations for streams with many years of no flow
Hjalmarson, Hjalmar W.; Thomas, Blakemore E.; ,
1990-01-01
In the southwestern United States, flood-frequency relations for streams that drain small arid basins are difficult to estimate, largely because of the extreme temporal and spatial variability of floods and the many years of no flow. A method is proposed that is based on the station-year method. The new method produces regional flood-frequency relations using all available annual peak-discharge data. The prediction errors for the relations are directly assessed using randomly selected subsamples of the annual peak discharges.
A sub-sampled approach to extremely low-dose STEM
Stevens, A.; Luzi, L.; Yang, H.; ...
2018-01-22
The inpainting of deliberately and randomly sub-sampled images offers a potential means to image specimens at a high resolution and under extremely low-dose conditions (≤1 e -/Å 2) using a scanning transmission electron microscope. We show that deliberate sub-sampling acquires images at least an order of magnitude faster than conventional low-dose methods for an equivalent electron dose. More importantly, when adaptive sub-sampling is implemented to acquire the images, there is a significant increase in the resolution and sensitivity which accompanies the increase in imaging speed. Lastly, we demonstrate the potential of this method for beam sensitive materials and in-situ observationsmore » by experimentally imaging the node distribution in a metal-organic framework.« less
A sub-sampled approach to extremely low-dose STEM
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stevens, A.; Luzi, L.; Yang, H.
The inpainting of deliberately and randomly sub-sampled images offers a potential means to image specimens at a high resolution and under extremely low-dose conditions (≤1 e -/Å 2) using a scanning transmission electron microscope. We show that deliberate sub-sampling acquires images at least an order of magnitude faster than conventional low-dose methods for an equivalent electron dose. More importantly, when adaptive sub-sampling is implemented to acquire the images, there is a significant increase in the resolution and sensitivity which accompanies the increase in imaging speed. Lastly, we demonstrate the potential of this method for beam sensitive materials and in-situ observationsmore » by experimentally imaging the node distribution in a metal-organic framework.« less
Ishwaran, Hemant; Lu, Min
2018-06-04
Random forests are a popular nonparametric tree ensemble procedure with broad applications to data analysis. While its widespread popularity stems from its prediction performance, an equally important feature is that it provides a fully nonparametric measure of variable importance (VIMP). A current limitation of VIMP, however, is that no systematic method exists for estimating its variance. As a solution, we propose a subsampling approach that can be used to estimate the variance of VIMP and for constructing confidence intervals. The method is general enough that it can be applied to many useful settings, including regression, classification, and survival problems. Using extensive simulations, we demonstrate the effectiveness of the subsampling estimator and in particular find that the delete-d jackknife variance estimator, a close cousin, is especially effective under low subsampling rates due to its bias correction properties. These 2 estimators are highly competitive when compared with the .164 bootstrap estimator, a modified bootstrap procedure designed to deal with ties in out-of-sample data. Most importantly, subsampling is computationally fast, thus making it especially attractive for big data settings. Copyright © 2018 John Wiley & Sons, Ltd.
Genealogical Properties of Subsamples in Highly Fecund Populations
NASA Astrophysics Data System (ADS)
Eldon, Bjarki; Freund, Fabian
2018-03-01
We consider some genealogical properties of nested samples. The complete sample is assumed to have been drawn from a natural population characterised by high fecundity and sweepstakes reproduction (abbreviated HFSR). The random gene genealogies of the samples are—due to our assumption of HFSR—modelled by coalescent processes which admit multiple mergers of ancestral lineages looking back in time. Among the genealogical properties we consider are the probability that the most recent common ancestor is shared between the complete sample and the subsample nested within the complete sample; we also compare the lengths of `internal' branches of nested genealogies between different coalescent processes. The results indicate how `informative' a subsample is about the properties of the larger complete sample, how much information is gained by increasing the sample size, and how the `informativeness' of the subsample varies between different coalescent processes.
Image subsampling and point scoring approaches for large-scale marine benthic monitoring programs
NASA Astrophysics Data System (ADS)
Perkins, Nicholas R.; Foster, Scott D.; Hill, Nicole A.; Barrett, Neville S.
2016-07-01
Benthic imagery is an effective tool for quantitative description of ecologically and economically important benthic habitats and biota. The recent development of autonomous underwater vehicles (AUVs) allows surveying of spatial scales that were previously unfeasible. However, an AUV collects a large number of images, the scoring of which is time and labour intensive. There is a need to optimise the way that subsamples of imagery are chosen and scored to gain meaningful inferences for ecological monitoring studies. We examine the trade-off between the number of images selected within transects and the number of random points scored within images on the percent cover of target biota, the typical output of such monitoring programs. We also investigate the efficacy of various image selection approaches, such as systematic or random, on the bias and precision of cover estimates. We use simulated biotas that have varying size, abundance and distributional patterns. We find that a relatively small sampling effort is required to minimise bias. An increased precision for groups that are likely to be the focus of monitoring programs is best gained through increasing the number of images sampled rather than the number of points scored within images. For rare species, sampling using point count approaches is unlikely to provide sufficient precision, and alternative sampling approaches may need to be employed. The approach by which images are selected (simple random sampling, regularly spaced etc.) had no discernible effect on mean and variance estimates, regardless of the distributional pattern of biota. Field validation of our findings is provided through Monte Carlo resampling analysis of a previously scored benthic survey from temperate waters. We show that point count sampling approaches are capable of providing relatively precise cover estimates for candidate groups that are not overly rare. The amount of sampling required, in terms of both the number of images and number of points, varies with the abundance, size and distributional pattern of target biota. Therefore, we advocate either the incorporation of prior knowledge or the use of baseline surveys to establish key properties of intended target biota in the initial stages of monitoring programs.
Subsampling effects in neuronal avalanche distributions recorded in vivo
Priesemann, Viola; Munk, Matthias HJ; Wibral, Michael
2009-01-01
Background Many systems in nature are characterized by complex behaviour where large cascades of events, or avalanches, unpredictably alternate with periods of little activity. Snow avalanches are an example. Often the size distribution f(s) of a system's avalanches follows a power law, and the branching parameter sigma, the average number of events triggered by a single preceding event, is unity. A power law for f(s), and sigma = 1, are hallmark features of self-organized critical (SOC) systems, and both have been found for neuronal activity in vitro. Therefore, and since SOC systems and neuronal activity both show large variability, long-term stability and memory capabilities, SOC has been proposed to govern neuronal dynamics in vivo. Testing this hypothesis is difficult because neuronal activity is spatially or temporally subsampled, while theories of SOC systems assume full sampling. To close this gap, we investigated how subsampling affects f(s) and sigma by imposing subsampling on three different SOC models. We then compared f(s) and sigma of the subsampled models with those of multielectrode local field potential (LFP) activity recorded in three macaque monkeys performing a short term memory task. Results Neither the LFP nor the subsampled SOC models showed a power law for f(s). Both, f(s) and sigma, depended sensitively on the subsampling geometry and the dynamics of the model. Only one of the SOC models, the Abelian Sandpile Model, exhibited f(s) and sigma similar to those calculated from LFP activity. Conclusion Since subsampling can prevent the observation of the characteristic power law and sigma in SOC systems, misclassifications of critical systems as sub- or supercritical are possible. Nevertheless, the system specific scaling of f(s) and sigma under subsampling conditions may prove useful to select physiologically motivated models of brain function. Models that better reproduce f(s) and sigma calculated from the physiological recordings may be selected over alternatives. PMID:19400967
Doyle, Suzanne R.; Donovan, Dennis M.
2014-01-01
Aims The purpose of this study was to explore the selection of predictor variables in the evaluation of drug treatment completion using an ensemble approach with classification trees. The basic methodology is reviewed and the subagging procedure of random subsampling is applied. Methods Among 234 individuals with stimulant use disorders randomized to a 12-Step facilitative intervention shown to increase stimulant use abstinence, 67.52% were classified as treatment completers. A total of 122 baseline variables were used to identify factors associated with completion. Findings The number of types of self-help activity involvement prior to treatment was the predominant predictor. Other effective predictors included better coping self-efficacy for substance use in high-risk situations, more days of prior meeting attendance, greater acceptance of the Disease model, higher confidence for not resuming use following discharge, lower ASI Drug and Alcohol composite scores, negative urine screens for cocaine or marijuana, and fewer employment problems. Conclusions The application of an ensemble subsampling regression tree method utilizes the fact that classification trees are unstable but, on average, produce an improved prediction of the completion of drug abuse treatment. The results support the notion there are early indicators of treatment completion that may allow for modification of approaches more tailored to fitting the needs of individuals and potentially provide more successful treatment engagement and improved outcomes. PMID:25134038
Kertechian, Sevag; Swami, Viren
2017-06-01
The Body Appreciation Scale-2 (BAS-2) is a measure of positive body image that has been found that have a one-dimensional factor structure in a number of different cultural groups. Here, we examined the factor structure and sex-based measurement invariance of a French translation of the BAS-2. A total of 652 university students (age M=21.33, SD=3.18) completed a newly-translated French version of the BAS-2. Exploratory factor analyses with a randomly selected split-half subsample revealed that the BAS-2 had a one-dimensional factor structure in both sexes. Confirmatory factor analyses with a second split-half subsample indicated that the one-dimensional factor structure had adequate fit following modifications and was invariant across sex. French BAS-2 scores had adequate internal consistency and men had significantly higher body appreciation than women (ds=.16-.23). These results provide preliminary support for the factorial validity of the French BAS-2. Copyright © 2017 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Oreopoulos, Lazaros
2004-01-01
The MODIS Level-3 optical thickness and effective radius cloud product is a gridded l deg. x 1 deg. dataset that is derived from aggregation and subsampling at 5 km of 1 km, resolution Level-2 orbital swath data (Level-2 granules). This study examines the impact of the 5 km subsampling on the mean, standard deviation and inhomogeneity parameter statistics of optical thickness and effective radius. The methodology is simple and consists of estimating mean errors for a large collection of Terra and Aqua Level-2 granules by taking the difference of the statistics at the original and subsampled resolutions. It is shown that the Level-3 sampling does not affect the various quantities investigated to the same degree, with second order moments suffering greater subsampling errors, as expected. Mean errors drop dramatically when averages over a sufficient number of regions (e.g., monthly and/or latitudinal averages) are taken, pointing to a dominance of errors that are of random nature. When histograms built from subsampled data with the same binning rules as in the Level-3 dataset are used to reconstruct the quantities of interest, the mean errors do not deteriorate significantly. The results in this paper provide guidance to users of MODIS Level-3 optical thickness and effective radius cloud products on the range of errors due to subsampling they should expect and perhaps account for, in scientific work with this dataset. In general, subsampling errors should not be a serious concern when moderate temporal and/or spatial averaging is performed.
Santin, G; Bénézet, L; Geoffroy-Perez, B; Bouyer, J; Guéguen, A
2017-02-01
The decline in participation rates in surveys, including epidemiological surveillance surveys, has become a real concern since it may increase nonresponse bias. The aim of this study is to estimate the contribution of a complementary survey among a subsample of nonrespondents, and the additional contribution of paradata in correcting for nonresponse bias in an occupational health surveillance survey. In 2010, 10,000 workers were randomly selected and sent a postal questionnaire. Sociodemographic data were available for the whole sample. After data collection of the questionnaires, a complementary survey among a random subsample of 500 nonrespondents was performed using a questionnaire administered by an interviewer. Paradata were collected for the complete subsample of the complementary survey. Nonresponse bias in the initial sample and in the combined samples were assessed using variables from administrative databases available for the whole sample, not subject to differential measurement errors. Corrected prevalences by reweighting technique were estimated by first using the initial survey alone and then the initial and complementary surveys combined, under several assumptions regarding the missing data process. Results were compared by computing relative errors. The response rates of the initial and complementary surveys were 23.6% and 62.6%, respectively. For the initial and the combined surveys, the relative errors decreased after correction for nonresponse on sociodemographic variables. For the combined surveys without paradata, relative errors decreased compared with the initial survey. The contribution of the paradata was weak. When a complex descriptive survey has a low response rate, a short complementary survey among nonrespondents with a protocol which aims to maximize the response rates, is useful. The contribution of sociodemographic variables in correcting for nonresponse bias is important whereas the additional contribution of paradata in correcting for nonresponse bias is questionable. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
Subsampling for dataset optimisation
NASA Astrophysics Data System (ADS)
Ließ, Mareike
2017-04-01
Soil-landscapes have formed by the interaction of soil-forming factors and pedogenic processes. In modelling these landscapes in their pedodiversity and the underlying processes, a representative unbiased dataset is required. This concerns model input as well as output data. However, very often big datasets are available which are highly heterogeneous and were gathered for various purposes, but not to model a particular process or data space. As a first step, the overall data space and/or landscape section to be modelled needs to be identified including considerations regarding scale and resolution. Then the available dataset needs to be optimised via subsampling to well represent this n-dimensional data space. A couple of well-known sampling designs may be adapted to suit this purpose. The overall approach follows three main strategies: (1) the data space may be condensed and de-correlated by a factor analysis to facilitate the subsampling process. (2) Different methods of pattern recognition serve to structure the n-dimensional data space to be modelled into units which then form the basis for the optimisation of an existing dataset through a sensible selection of samples. Along the way, data units for which there is currently insufficient soil data available may be identified. And (3) random samples from the n-dimensional data space may be replaced by similar samples from the available dataset. While being a presupposition to develop data-driven statistical models, this approach may also help to develop universal process models and identify limitations in existing models.
Perceived somatic and affective barriers for self-efficacy and physical activity.
Warner, Lisa M; Wolff, Julia K; Spuling, Svenja M; Wurm, Susanne
2017-05-01
According to Bandura's social-cognitive theory, perceptions of somatic and affective barriers are sources of self-efficacy. This longitudinal study compares general indicators of health barriers with measures of perceived somatic and affective barriers to predict self-efficacy and accelerometer-assessed physical activity in a subsample of n = 153 (selected at random from N = 310) community-dwelling German older adults. Perceived somatic and affective barriers longitudinally predicted physical activity mediated by self-efficacy, whereas general health barriers did not. Perceived health barriers to physical activity might be more important than more objective health barriers for older adults' physical activity levels.
NASA Astrophysics Data System (ADS)
Mishra, Aashwin; Iaccarino, Gianluca
2017-11-01
In spite of their deficiencies, RANS models represent the workhorse for industrial investigations into turbulent flows. In this context, it is essential to provide diagnostic measures to assess the quality of RANS predictions. To this end, the primary step is to identify feature importances amongst massive sets of potentially descriptive and discriminative flow features. This aids the physical interpretability of the resultant discrepancy model and its extensibility to similar problems. Recent investigations have utilized approaches such as Random Forests, Support Vector Machines and the Least Absolute Shrinkage and Selection Operator for feature selection. With examples, we exhibit how such methods may not be suitable for turbulent flow datasets. The underlying rationale, such as the correlation bias and the required conditions for the success of penalized algorithms, are discussed with illustrative examples. Finally, we provide alternate approaches using convex combinations of regularized regression approaches and randomized sub-sampling in combination with feature selection algorithms, to infer model structure from data. This research was supported by the Defense Advanced Research Projects Agency under the Enabling Quantification of Uncertainty in Physical Systems (EQUiPS) project (technical monitor: Dr Fariba Fahroo).
STRUCTURE OF THE UNIVERSITY PERSONALITY INVENTORY FOR CHINESE COLLEGE STUDENTS.
Zhang, Jieting; Lanza, Stephanie; Zhang, Minqiang; Su, Binyuan
2015-06-01
The University Personality Inventory, a mental health instrument for college students, is frequently used for screening in China. However, its unidimensionality has been questioned. This study examined its dimensions to provide more information about the specific mental problems for students at risk. Four subsamples were randomly created from a sample (N = 6,110; M age = 19.1 yr.) of students at a university in China. Principal component analysis with Promax rotation was applied on the first two subsamples to explore dimension of the inventory. Confirmatory factor analysis was conducted on the third subsample to verify the exploratory dimensions. Finally, the identified factors were compared to the Symptom Checklist-90 (SCL-90) to support validity, and sex differences were examined, based on the fourth subsample. Five factors were identified: Physical Symptoms, Cognitive Symptoms, Emotional Vulnerability, Social Avoidance, and Interpersonal Sensitivity, accounting for 60.3% of the variance. All the five factors were significantly correlated with the SCL-90. Women scored significantly higher than men on Cognitive Symptoms and Interpersonal Sensitivity.
Sisic, Nedim; Jelicic, Mario; Pehar, Miran; Spasic, Miodrag; Sekulic, Damir
2016-01-01
In basketball, anthropometric status is an important factor when identifying and selecting talents, while agility is one of the most vital motor performances. The aim of this investigation was to evaluate the influence of anthropometric variables and power capacities on different preplanned agility performances. The participants were 92 high-level, junior-age basketball players (16-17 years of age; 187.6±8.72 cm in body height, 78.40±12.26 kg in body mass), randomly divided into a validation and cross-validation subsample. The predictors set consisted of 16 anthropometric variables, three tests of power-capacities (Sargent-jump, broad-jump and medicine-ball-throw) as predictors. The criteria were three tests of agility: a T-Shape-Test; a Zig-Zag-Test, and a test of running with a 180-degree turn (T180). Forward stepwise multiple regressions were calculated for validation subsamples and then cross-validated. Cross validation included correlations between observed and predicted scores, dependent samples t-test between predicted and observed scores; and Bland Altman graphics. Analysis of the variance identified centres being advanced in most of the anthropometric indices, and medicine-ball-throw (all at P<0.05); with no significant between-position-differences for other studied motor performances. Multiple regression models originally calculated for the validation subsample were then cross-validated, and confirmed for Zig-zag-Test (R of 0.71 and 0.72 for the validation and cross-validation subsample, respectively). Anthropometrics were not strongly related to agility performance, but leg length is found to be negatively associated with performance in basketball-specific agility. Power capacities are confirmed to be an important factor in agility. The results highlighted the importance of sport-specific tests when studying pre-planned agility performance in basketball. The improvement in power capacities will probably result in an improvement in agility in basketball athletes, while anthropometric indices should be used in order to identify those athletes who can achieve superior agility performance.
Chen, Zhijian; Craiu, Radu V; Bull, Shelley B
2014-11-01
In focused studies designed to follow up associations detected in a genome-wide association study (GWAS), investigators can proceed to fine-map a genomic region by targeted sequencing or dense genotyping of all variants in the region, aiming to identify a functional sequence variant. For the analysis of a quantitative trait, we consider a Bayesian approach to fine-mapping study design that incorporates stratification according to a promising GWAS tag SNP in the same region. Improved cost-efficiency can be achieved when the fine-mapping phase incorporates a two-stage design, with identification of a smaller set of more promising variants in a subsample taken in stage 1, followed by their evaluation in an independent stage 2 subsample. To avoid the potential negative impact of genetic model misspecification on inference we incorporate genetic model selection based on posterior probabilities for each competing model. Our simulation study shows that, compared to simple random sampling that ignores genetic information from GWAS, tag-SNP-based stratified sample allocation methods reduce the number of variants continuing to stage 2 and are more likely to promote the functional sequence variant into confirmation studies. © 2014 WILEY PERIODICALS, INC.
Capers, Patrice L.; Brown, Andrew W.; Dawson, John A.; Allison, David B.
2015-01-01
Background: Meta-research can involve manual retrieval and evaluation of research, which is resource intensive. Creation of high throughput methods (e.g., search heuristics, crowdsourcing) has improved feasibility of large meta-research questions, but possibly at the cost of accuracy. Objective: To evaluate the use of double sampling combined with multiple imputation (DS + MI) to address meta-research questions, using as an example adherence of PubMed entries to two simple consolidated standards of reporting trials guidelines for titles and abstracts. Methods: For the DS large sample, we retrieved all PubMed entries satisfying the filters: RCT, human, abstract available, and English language (n = 322, 107). For the DS subsample, we randomly sampled 500 entries from the large sample. The large sample was evaluated with a lower rigor, higher throughput (RLOTHI) method using search heuristics, while the subsample was evaluated using a higher rigor, lower throughput (RHITLO) human rating method. Multiple imputation of the missing-completely at-random RHITLO data for the large sample was informed by: RHITLO data from the subsample; RLOTHI data from the large sample; whether a study was an RCT; and country and year of publication. Results: The RHITLO and RLOTHI methods in the subsample largely agreed (phi coefficients: title = 1.00, abstract = 0.92). Compliance with abstract and title criteria has increased over time, with non-US countries improving more rapidly. DS + MI logistic regression estimates were more precise than subsample estimates (e.g., 95% CI for change in title and abstract compliance by year: subsample RHITLO 1.050–1.174 vs. DS + MI 1.082–1.151). As evidence of improved accuracy, DS + MI coefficient estimates were closer to RHITLO than the large sample RLOTHI. Conclusion: Our results support our hypothesis that DS + MI would result in improved precision and accuracy. This method is flexible and may provide a practical way to examine large corpora of literature. PMID:25988135
NASA Technical Reports Server (NTRS)
Borsky, P. N.
1974-01-01
A random sample of selected communities near JFK Airport were interviewed. Subsamples, with differing feelings of fear of aircraft crashes and different locations of residence were invited to participate in a laboratory experiment. The subjects were exposed to tape recordings of simulated flyovers of aircraft in approach and departure operations at nominal distances from the airport. The subjects judged the extent of noise annoyance and acceptability of the aircraft noises. Results indicate that level of noise is most significant in affecting annoyance judgements. Subjects with feelings of high fear report significantly more annoyance and less acceptability of aircraft noise than subjects with feelings of low fear.
Friendship chemistry: An examination of underlying factors☆.
Campbell, Kelly; Holderness, Nicole; Riggs, Matt
2015-06-01
Interpersonal chemistry refers to a connection between two individuals that exists upon first meeting. The goal of the current study is to identify beliefs about the underlying components of friendship chemistry. Individuals respond to an online Friendship Chemistry Questionnaire containing items that are derived from interdependence theory and the friendship formation literature. Participants are randomly divided into two subsamples. A principal axis factor analysis with promax rotation is performed on subsample 1 and produces 5 factors: Reciprocal candor, mutual interest, personableness, similarity, and physical attraction. A confirmatory factor analysis is conducted using subsample 2 and provides support for the 5-factor model. Participants with agreeable, open, and conscientious personalities more commonly report experiencing friendship chemistry, as do those who are female, young, and European/white. Responses from participants who have never experienced chemistry are qualitatively analyzed. Limitations and directions for future research are discussed.
Roth, David L.; Gitlin, Laura N.; Coon, David W.; Stevens, Alan B.; Burgio, Louis D.; Gallagher-Thompson, Dolores; Belle, Steven H.; Burns, Robert
2008-01-01
A modified version of the Revised Memory and Behavior Problems Checklist (RMBPC; L. Teri et al., 1992) was administered across 6 different sites to 1,229 family caregivers of community-dwelling adults with dementia. The total sample was divided randomly into 2 subsamples. Principal components analyses on occurrence responses and reaction ratings from the first subsample resulted in a 3-factor solution that closely resembled the originally proposed dimensions (memory-related problems, disruptive behaviors, and depression). Confirmatory factor analyses on data from the second subsample indicated adequate fit for the 3-factor model. Correlations with other caregiver and care-recipient measures supported the convergent and discriminant validity of the RMBPC measures. In addition, female caregivers and White caregivers reported more problems, on average, than male caregivers and African American caregivers, respectively. PMID:14692875
STRUCTURE OF THE UNIVERSITY PERSONALITY INVENTORY FOR CHINESE COLLEGE STUDENTS1,2
ZHANG, JIETING; LANZA, STEPHANIE; ZHANG, MINQIANG; SU, BINYUAN
2016-01-01
Summary The University Personality Inventory, a mental health instrument for college students, is frequently used for screening in China. However, its unidimensionality has been questioned. This study examined its dimensions to provide more information about the specific mental problems for students at risk. Four subsamples were randomly created from a sample (N = 6,110; M age = 19.1 yr.) of students at a university in China. Principal component analysis with Promax rotation was applied on the first two subsamples to explore dimension of the inventory. Confirmatory factor analysis was conducted on the third subsample to verify the exploratory dimensions. Finally, the identified factors were compared to the Sympton Checklist–90 (SCL–90) to support validity, and sex differences were examined, based on the fourth subsample. Five factors were identified: Physical Symptoms, Cognitive Symptoms, Emotional Vulnerability, Social Avoidance, and Interpersonal Sensitivity, accounting for 60.3% of the variance. All the five factors were significantly correlated with the SCL–90. Women significantly scored higher than men on Cognitive Symptoms and Interpersonal Sensitivity. PMID:25933045
The mean and variance of phylogenetic diversity under rarefaction
Matsen, Frederick A.
2013-01-01
Summary Phylogenetic diversity (PD) depends on sampling depth, which complicates the comparison of PD between samples of different depth. One approach to dealing with differing sample depth for a given diversity statistic is to rarefy, which means to take a random subset of a given size of the original sample. Exact analytical formulae for the mean and variance of species richness under rarefaction have existed for some time but no such solution exists for PD.We have derived exact formulae for the mean and variance of PD under rarefaction. We confirm that these formulae are correct by comparing exact solution mean and variance to that calculated by repeated random (Monte Carlo) subsampling of a dataset of stem counts of woody shrubs of Toohey Forest, Queensland, Australia. We also demonstrate the application of the method using two examples: identifying hotspots of mammalian diversity in Australasian ecoregions, and characterising the human vaginal microbiome.There is a very high degree of correspondence between the analytical and random subsampling methods for calculating mean and variance of PD under rarefaction, although the Monte Carlo method requires a large number of random draws to converge on the exact solution for the variance.Rarefaction of mammalian PD of ecoregions in Australasia to a common standard of 25 species reveals very different rank orderings of ecoregions, indicating quite different hotspots of diversity than those obtained for unrarefied PD. The application of these methods to the vaginal microbiome shows that a classical score used to quantify bacterial vaginosis is correlated with the shape of the rarefaction curve.The analytical formulae for the mean and variance of PD under rarefaction are both exact and more efficient than repeated subsampling. Rarefaction of PD allows for many applications where comparisons of samples of different depth is required. PMID:23833701
The mean and variance of phylogenetic diversity under rarefaction.
Nipperess, David A; Matsen, Frederick A
2013-06-01
Phylogenetic diversity (PD) depends on sampling depth, which complicates the comparison of PD between samples of different depth. One approach to dealing with differing sample depth for a given diversity statistic is to rarefy, which means to take a random subset of a given size of the original sample. Exact analytical formulae for the mean and variance of species richness under rarefaction have existed for some time but no such solution exists for PD.We have derived exact formulae for the mean and variance of PD under rarefaction. We confirm that these formulae are correct by comparing exact solution mean and variance to that calculated by repeated random (Monte Carlo) subsampling of a dataset of stem counts of woody shrubs of Toohey Forest, Queensland, Australia. We also demonstrate the application of the method using two examples: identifying hotspots of mammalian diversity in Australasian ecoregions, and characterising the human vaginal microbiome.There is a very high degree of correspondence between the analytical and random subsampling methods for calculating mean and variance of PD under rarefaction, although the Monte Carlo method requires a large number of random draws to converge on the exact solution for the variance.Rarefaction of mammalian PD of ecoregions in Australasia to a common standard of 25 species reveals very different rank orderings of ecoregions, indicating quite different hotspots of diversity than those obtained for unrarefied PD. The application of these methods to the vaginal microbiome shows that a classical score used to quantify bacterial vaginosis is correlated with the shape of the rarefaction curve.The analytical formulae for the mean and variance of PD under rarefaction are both exact and more efficient than repeated subsampling. Rarefaction of PD allows for many applications where comparisons of samples of different depth is required.
Statistical considerations for grain-size analyses of tills
Jacobs, A.M.
1971-01-01
Relative percentages of sand, silt, and clay from samples of the same till unit are not identical because of different lithologies in the source areas, sorting in transport, random variation, and experimental error. Random variation and experimental error can be isolated from the other two as follows. For each particle-size class of each till unit, a standard population is determined by using a normally distributed, representative group of data. New measurements are compared with the standard population and, if they compare satisfactorily, the experimental error is not significant and random variation is within the expected range for the population. The outcome of the comparison depends on numerical criteria derived from a graphical method rather than on a more commonly used one-way analysis of variance with two treatments. If the number of samples and the standard deviation of the standard population are substituted in a t-test equation, a family of hyperbolas is generated, each of which corresponds to a specific number of subsamples taken from each new sample. The axes of the graphs of the hyperbolas are the standard deviation of new measurements (horizontal axis) and the difference between the means of the new measurements and the standard population (vertical axis). The area between the two branches of each hyperbola corresponds to a satisfactory comparison between the new measurements and the standard population. Measurements from a new sample can be tested by plotting their standard deviation vs. difference in means on axes containing a hyperbola corresponding to the specific number of subsamples used. If the point lies between the branches of the hyperbola, the measurements are considered reliable. But if the point lies outside this region, the measurements are repeated. Because the critical segment of the hyperbola is approximately a straight line parallel to the horizontal axis, the test is simplified to a comparison between the means of the standard population and the means of the subsample. The minimum number of subsamples required to prove significant variation between samples caused by different lithologies in the source areas and sorting in transport can be determined directly from the graphical method. The minimum number of subsamples required is the maximum number to be run for economy of effort. ?? 1971 Plenum Publishing Corporation.
Charlton, Karen; Menyanu, Elias; Biritwum, Richard Berko; Naidoo, Nirmala; Pieterse, Chiné; Madurai, Savathree (Lorna); Baumgartner, Jeannine; Asare, George A; Thiele, Elizabeth; Schutte, Aletta E; Kowal, Paul
2016-01-01
Introduction Attempting to curb the rising epidemic of hypertension, South Africa implemented legislation in June 2016 mandating maximum sodium levels in a range of manufactured foods that contribute significantly to population salt intake. This natural experiment, comparing two African countries with and without salt legislation, will provide timely information on the impact of legislative approaches addressing the food supply to improve blood pressure in African populations. This article outlines the design of this ongoing prospective nested cohort study. Methods and analysis Baseline sodium intake was assessed in a nested cohort of the WHO Study on global AGEing and adult health (WHO-SAGE) wave 2 (2014–2015), a multinational longitudinal study on the health and well-being of adults and the ageing process. The South African cohort consisted of randomly selected households (n=4030) across the country. Spot and 24-hour urine samples are collected in a random subsample (n=1200) and sodium, potassium, creatinine and iodine analysed. Salt behaviour and sociodemographic data are captured using face-to-face interviews, alongside blood pressure and anthropometric measures. Ghana, the selected control country with no formal salt policy, provided a nested subsample (n=1200) contributing spot and 24-hour urine samples from the SAGE Ghana cohort (n=5000). Follow-up interviews and urine collection (wave 3) in both countries will take place in 2017 (postlegislation) to assess change in population-level sodium intake and blood pressure. Ethics and dissemination SAGE was approved by the WHO Ethics Review Committee (reference number RPC149) with local approval from the North-West University Human Research Ethics Committee and University of the Witwatersrand Human Research Ethics Committee (South Africa), and University of Ghana Medical School Ethics and Protocol Review Committee (Ghana). The results of the study will be published in peer-reviewed international journals, presented at national and international conferences, and summarised as research and policy briefs. PMID:27903563
Comparative analyses of basal rate of metabolism in mammals: data selection does matter.
Genoud, Michel; Isler, Karin; Martin, Robert D
2018-02-01
Basal rate of metabolism (BMR) is a physiological parameter that should be measured under strictly defined experimental conditions. In comparative analyses among mammals BMR is widely used as an index of the intensity of the metabolic machinery or as a proxy for energy expenditure. Many databases with BMR values for mammals are available, but the criteria used to select metabolic data as BMR estimates have often varied and the potential effect of this variability has rarely been questioned. We provide a new, expanded BMR database reflecting compliance with standard criteria (resting, postabsorptive state; thermal neutrality; adult, non-reproductive status for females) and examine potential effects of differential selectivity on the results of comparative analyses. The database includes 1739 different entries for 817 species of mammals, compiled from the original sources. It provides information permitting assessment of the validity of each estimate and presents the value closest to a proper BMR for each entry. Using different selection criteria, several alternative data sets were extracted and used in comparative analyses of (i) the scaling of BMR to body mass and (ii) the relationship between brain mass and BMR. It was expected that results would be especially dependent on selection criteria with small sample sizes and with relatively weak relationships. Phylogenetically informed regression (phylogenetic generalized least squares, PGLS) was applied to the alternative data sets for several different clades (Mammalia, Eutheria, Metatheria, or individual orders). For Mammalia, a 'subsampling procedure' was also applied, in which random subsamples of different sample sizes were taken from each original data set and successively analysed. In each case, two data sets with identical sample size and species, but comprising BMR data with different degrees of reliability, were compared. Selection criteria had minor effects on scaling equations computed for large clades (Mammalia, Eutheria, Metatheria), although less-reliable estimates of BMR were generally about 12-20% larger than more-reliable ones. Larger effects were found with more-limited clades, such as sciuromorph rodents. For the relationship between BMR and brain mass the results of comparative analyses were found to depend strongly on the data set used, especially with more-limited, order-level clades. In fact, with small sample sizes (e.g. <100) results often appeared erratic. Subsampling revealed that sample size has a non-linear effect on the probability of a zero slope for a given relationship. Depending on the species included, results could differ dramatically, especially with small sample sizes. Overall, our findings indicate a need for due diligence when selecting BMR estimates and caution regarding results (even if seemingly significant) with small sample sizes. © 2017 Cambridge Philosophical Society.
Friendship chemistry: An examination of underlying factors☆
Campbell, Kelly; Holderness, Nicole; Riggs, Matt
2015-01-01
Interpersonal chemistry refers to a connection between two individuals that exists upon first meeting. The goal of the current study is to identify beliefs about the underlying components of friendship chemistry. Individuals respond to an online Friendship Chemistry Questionnaire containing items that are derived from interdependence theory and the friendship formation literature. Participants are randomly divided into two subsamples. A principal axis factor analysis with promax rotation is performed on subsample 1 and produces 5 factors: Reciprocal candor, mutual interest, personableness, similarity, and physical attraction. A confirmatory factor analysis is conducted using subsample 2 and provides support for the 5-factor model. Participants with agreeable, open, and conscientious personalities more commonly report experiencing friendship chemistry, as do those who are female, young, and European/white. Responses from participants who have never experienced chemistry are qualitatively analyzed. Limitations and directions for future research are discussed. PMID:26097283
ERIC Educational Resources Information Center
Frey, Karin S.; Hirschstein, Miriam K.; Snell, Jennie L.; Edstrom, Leihua Van Schoiack; MacKenzie, Elizabeth P.; Broderick, Carole J.
2005-01-01
Six schools were randomly assigned to a multilevel bullying intervention or a control condition. Children in Grades 3-6 (N=1,023) completed pre- and posttest surveys of behaviors and beliefs and were rated by teachers. Observers coded playground behavior of a random subsample (n=544). Hierarchical analyses of changes in playground behavior…
Allelic variability in species and stocks of Lake Superior ciscoes (Coregoninae)
Todd, Thomas N.
1981-01-01
Starch gel electrophoresis was used as a means of recognizing species and stocks in Lake Superior Coregonus. Allelic variability at isocitrate dehydrogenase and glycerol-3-phosphate dehydrogenase loci was recorded for samples of lake herring (Coregonus artedii), bloater (C. hoyi), kiyi (C. kiyi), and shortjaw cisco (C. zenithicus) from five Lake Superior localities. The observed frequencies of genotypes within each subsample did not differ significantly from those expected on the basis of random mating, and suggested that each subsample represented either a random sample from a larger randomly mating population or an independent and isolated subpopulation within which mating was random. Significant contingency X2 values for comparisons between both localities and species suggested that more than one randomly mating population occurred among the Lake Superior ciscoes, but did not reveal how many such populations there were. In contrast to the genetic results of this study, morphology seems to be a better descriptor of cisco stocks, and identification of cisco stocks and species will still have to be based on morphological criteria until more data are forthcoming. Where several species are sympatric, management should strive to preserve the least abundant. Failure to do so could result in the extinction or depletion of the rarer forms.
Mullally, B J; Greiner, B A; Allwright, S; Paul, G; Perry, I J
2008-12-01
This study establishes baseline prevalence of smoking and cigarette consumption among Cork bar workers prior to the Republic of Ireland's (ROI) smokefree workplace legislation and compares gender- and age-specific smoking rates and estimates the adjusted odds of being a smoker for Cork bar workers relative to the general population. Cross-sectional random sample of bar workers in Cork city and cross-sectional random telephone survey of the general population were conducted prior to the smokefree legislation. Self reported smoking prevalence among Cork bar workers (n = 129) was 54% (58% using cotinine-validated measures), with particularly high rates in women (70%) and 18-28 years old (72%). Within the ROI (n = 1,240) sub-sample rates were substantially lower at 28%. Bar workers were twice as likely to be smokers as the general population sub-sample (OR = 2.15). Cork bar workers constitute an occupational group with an extremely high smoking prevalence.
A psychometric study of the Test of Everyday Attention for Children in the Chinese setting.
Chan, Raymond C K; Wang, Li; Ye, Jiawen; Leung, Winnie W Y; Mok, Monica Y K
2008-07-01
To explore the psychometric properties of the Test of Everyday Attention for Children (TEA-Ch) in the context of a Chinese setting. Confirmatory factor analysis was conducted to examine the construct validity of the Chinese version of the TEA-Ch among a group of 232 children without attention deficit hyperactivity disorder (ADHD). Test-retest reliability was tested on a random sub-sample of 20 children at a 4-week interval. Clinical discrimination was also examined by comparing children with and without ADHD (22 in each group) on the performances of the TEA-Ch. The current Chinese sample demonstrated a three-factor solution for attentional performance among children without ADHD, namely selective attention, executive control/switch, and sustained attention (chi(2)(24)=34.56; RMSEA=.044; p=.075). Moreover, the whole test demonstrated acceptable test-retest reliability at a 4-week interval among a small sub-sample. Children with ADHD performed significantly more poorly than healthy controls in most of the subtests of the TEA-Ch. The results of the present study demonstrate that the test items remain useful in China, a culture very different from that in which the test originated. Finally, the TEA-Ch also presents several advantages when compared to other conventional objective measures of attention.
Mining Health App Data to Find More and Less Successful Weight Loss Subgroups
2016-01-01
Background More than half of all smartphone app downloads involve weight, diet, and exercise. If successful, these lifestyle apps may have far-reaching effects for disease prevention and health cost-savings, but few researchers have analyzed data from these apps. Objective The purposes of this study were to analyze data from a commercial health app (Lose It!) in order to identify successful weight loss subgroups via exploratory analyses and to verify the stability of the results. Methods Cross-sectional, de-identified data from Lose It! were analyzed. This dataset (n=12,427,196) was randomly split into 24 subsamples, and this study used 3 subsamples (combined n=972,687). Classification and regression tree methods were used to explore groupings of weight loss with one subsample, with descriptive analyses to examine other group characteristics. Data mining validation methods were conducted with 2 additional subsamples. Results In subsample 1, 14.96% of users lost 5% or more of their starting body weight. Classification and regression tree analysis identified 3 distinct subgroups: “the occasional users” had the lowest proportion (4.87%) of individuals who successfully lost weight; “the basic users” had 37.61% weight loss success; and “the power users” achieved the highest percentage of weight loss success at 72.70%. Behavioral factors delineated the subgroups, though app-related behavioral characteristics further distinguished them. Results were replicated in further analyses with separate subsamples. Conclusions This study demonstrates that distinct subgroups can be identified in “messy” commercial app data and the identified subgroups can be replicated in independent samples. Behavioral factors and use of custom app features characterized the subgroups. Targeting and tailoring information to particular subgroups could enhance weight loss success. Future studies should replicate data mining analyses to increase methodology rigor. PMID:27301853
40 CFR 761.353 - Second level of sample selection.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Second level of sample selection. 761...-Site Disposal, in Accordance With § 761.61 § 761.353 Second level of sample selection. The second level of sample selection reduces the size of the 19-liter subsample that was collected according to...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schaumberg, Andrew
The Omics Tools package provides several small trivial tools for work in genomics. This single portable package, the omics.jar file, is a toolbox that works in any Java-based environment, including PCs, Macs, and supercomputers. The number of tools is expected to grow. One tool (called cmsearch.hadoop or cmsearch.local), calls the external cmsearch program to predict non-coding RNA in a genome. The cmsearch program is part of the third-party Infernal package. Omics Tools does not contain Infernal. Infernal may be installed separately. The cmsearch.hadoop subtool requires Apache Hadoop and runs on a supercomputer, though cmsearch.local does not and runs on amore » server. Omics Tools does not contain Hadoop. Hadoop mat be installed separartely The other tools (cmgbk, cmgff, fastats, pal, randgrp, randgrpr, randsub) do not interface with third-party tools. Omics Tools is written in Java and Scala programming languages. Invoking the help command shows currently available tools, as shown below: schaumbe@gpint06:~/proj/omics$ java -jar omics.jar help Known commands are: cmgbk : compare cmsearch and GenBank Infernal hits cmgff : compare hits among two GFF (version 3) files cmsearch.hadoop : find Infernal hits in a genome, on your supercomputer cmsearch.local : find Infernal hits in a genome, on your workstation fastats : FASTA stats, e.g. # bases, GC content pal : stem-loop motif detection by palindromic sequence search (code stub) randgrp : random subsample without replacement, of groups randgrpr : random subsample with replacement, of groups (fast) randsub : random subsample without replacement, of file lines For more help regarding a particular command, use: java -jar omics.jar command help Usage: java -jar omics.jar command args« less
NASA Astrophysics Data System (ADS)
Willis, J. P.; Ramos-Ceja, M. E.; Muzzin, A.; Pacaud, F.; Yee, H. K. C.; Wilson, G.
2018-04-01
We present a comparison of two samples of z > 0.8 galaxy clusters selected using different wavelength-dependent techniques and examine the physical differences between them. We consider 18 clusters from the X-ray selected XMM-LSS distant cluster survey and 92 clusters from the optical-MIR selected SpARCS cluster survey. Both samples are selected from the same approximately 9 square degree sky area and we examine them using common XMM-Newton, Spitzer-SWIRE and CFHT Legacy Survey data. Clusters from each sample are compared employing aperture measures of X-ray and MIR emission. We divide the SpARCS distant cluster sample into three sub-samples: a) X-ray bright, b) X-ray faint, MIR bright, and c) X-ray faint, MIR faint clusters. We determine that X-ray and MIR selected clusters display very similar surface brightness distributions of galaxy MIR light. In addition, the average location and amplitude of the galaxy red sequence as measured from stacked colour histograms is very similar in the X-ray and MIR-selected samples. The sub-sample of X-ray faint, MIR bright clusters displays a distribution of BCG-barycentre position offsets which extends to higher values than all other samples. This observation indicates that such clusters may exist in a more disturbed state compared to the majority of the distant cluster population sampled by XMM-LSS and SpARCS. This conclusion is supported by stacked X-ray images for the X-ray faint, MIR bright cluster sub-sample that display weak, centrally-concentrated X-ray emission, consistent with a population of growing clusters accreting from an extended envelope of material.
Rasch analysis of the Rosenberg Self-Esteem Scale with African Americans.
Chao, Ruth Chu-Lien; Vidacovich, Courtney; Green, Kathy E
2017-03-01
Effectively diagnosing African Americans' self-esteem has posed an unresolved challenge. To address this assessment issue, we conducted exploratory factor analysis and Rasch analysis to assess the psychometric characteristics of the Rosenberg Self-Esteem Scale (RSES, Rosenberg, 1965) for African American college students. The dimensional structure of the RSES was first identified with the first subsample (i.e., calibration subsample) and then held up under cross-validation with a second subsample (i.e., validation subsample). Exploratory factor analysis and Rasch analysis both supported unidimensionality of the measure, with that finding replicated for a random split of the sample. Response scale use was generally appropriate, items were endorsed at a high level reflecting high levels of self-esteem, and person separation and reliability of person separation were adequate, and reflected results similar to those found in prior research. However, as some categories were infrequently used, we also collapsed scale points and found a slight improvement in scale and item indices. No differential item functioning was found by sex or having received professional assistance versus not; there were no mean score differences by age group, marital status, or year in college. Two items were seen as problematic. Implications for theory and research on multicultural mental health are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Void statistics, scaling, and the origins of large-scale structure
NASA Technical Reports Server (NTRS)
Fry, J. N.; Giovanelli, Riccardo; Haynes, Martha P.; Melott, Adrian L.; Scherrer, Robert J.
1989-01-01
The probability that a volume of the universe of given size and shape spaced at random will be void of galaxies is used here to study various models of the origin of cosmological structures. Numerical simulations are conducted on hot-particle and cold-particle-modulated inflationary models with and without biasing, on isothermal or initially Poisson models, and on models where structure is seeded by loops of cosmic string. For the Pisces-Perseus redshift compilation of Giovanelli and Haynes (1985), it is found that hierarchical scaling is obeyed for subsamples constructed with different limiting magnitudes and subsamples taken at random. This result confirms that the hierarchical ansatz holds valid to high order and supports the idea that structure in the observed universe evolves by a regular process from an almost Gaussian primordial state. Neutrino models without biasing show the effect of a strong feature in the initial power spectrum. Cosmic string models do not agree well with the galaxy data.
Three-factor structure for Epistemic Belief Inventory: A cross-validation study
2017-01-01
Research on epistemic beliefs has been hampered by lack of validated models and measurement instruments. The most widely used instrument is the Epistemological Questionnaire, which has been criticized for validity, and it has been proposed a new instrument based in the Epistemological Questionnaire: the Epistemic Belief Inventory. The Spanish-language version of Epistemic Belief Inventory was applied to 1,785 Chilean high school students. Exploratory and confirmatory factor analyses in independent subsamples were performed. A three factor structure emerged and was confirmed. Reliability was comparable to other studies, and the factor structure was invariant among randomized subsamples. The structure that was found does not replicate the one proposed originally, but results are interpreted in light of embedded systemic model of epistemological beliefs. PMID:28278258
Kelly, Sharon M; Schwartz, Robert P; Oʼgrady, Kevin E; Gandhi, Devang; Jaffe, Jerome H
2012-06-01
Human immunodeficiency virus (HIV)-risk behaviors were examined at 4- and 12-month follow-up for 230 newly admitted methadone patients randomly assigned to receive either methadone only (n = 99) or methadone with drug abuse counseling (n = 131) in the first 4 months of treatment. The AIDS Risk Assessment was administered at baseline (treatment entry) and at 4- and 12-month follow-up. Linear mixed model analysis examined changes in HIV drug- and sex-risk behaviors over the 12 months in the total sample, drug-risk behaviors in the subsample that reported injecting drugs at baseline (n = 110), and sex-risk behaviors in the subsample that reported engaging in unprotected sex at baseline (n = 130). Significant decreases over time were found in the frequencies of injecting, injecting with other injectors, and sharing cooker, cotton, or rinse water in the total sample and the injector subsample (P < 0.05). Decreases were also found in the frequencies of having sex without a condom either with someone who was not a spouse or primary partner or while high (P < 0.05) in the total sample and the frequencies of having sex without a condom and having sex without a condom while high in the unprotected-sex subsample (P < 0.05). No significant treatment group main effects or Treatment Group × Time interaction effects were found in any of the HIV-risk behaviors in the total sample or either subsample (P > 0.05). During the first 12 months of treatment, providing drug abuse counseling with methadone compared with providing methadone alone was not associated with significant changes in HIV-risk behaviors for methadone maintenance patients.
Sampling is the act of selecting items from a specified population in order to estimate the parameters of that population (e.g., selecting soil samples to characterize the properties at an environmental site). Sampling occurs at various levels and times throughout an environmenta...
Influence of Self-Regulation on the Development of Children's Number Sense
ERIC Educational Resources Information Center
Ivrendi, Asiye
2011-01-01
The present study examined predictive power of behavioral self-regulation, family and child characteristics on children's number sense. The participants consisted of 101 kindergarten children. A subsample of 30 children was randomly chosen for the reliability procedures of Assessing Number Sense and Head, Toes, Knees and Shoulders instruments.…
ERIC Educational Resources Information Center
Astin, Helen S.; Cross, Patricia H.
Data tables are compiled on the characteristics of black freshmen entering a representative sanple of 393 predominately black and predominately white academic institutions. Using a ten percent random subsample of original data compiled by Alexander W. Astin for the Cooperative Institutional Research program, the researchers present extensive…
Matching with Multiple Control Groups with Adjustment for Group Differences
ERIC Educational Resources Information Center
Stuart, Elizabeth A.; Rubin, Donald B.
2008-01-01
When estimating causal effects from observational data, it is desirable to approximate a randomized experiment as closely as possible. This goal can often be achieved by choosing a subsample from the original control group that matches the treatment group on the distribution of the observed covariates. However, sometimes the original control group…
Promoting Healthy Weight among Children with Developmental Delays
ERIC Educational Resources Information Center
Natale, Ruby R.; Camejo, Stephanie T.; Asfour, Lila; Uhlhorn, Susan B.; Delamater, Alan; Messiah, Sarah E.
2017-01-01
An extensive body of research demonstrates a higher prevalence of obesity among children with developmental delays (DD) versus children without delays. This analysis examined the effectiveness of a randomized controlled trial to promote healthy weight in a subsample of preschool-age children with DD (n = 71) on the adoption of quality nutrition…
The Influence of Mark-Recapture Sampling Effort on Estimates of Rock Lobster Survival
Kordjazi, Ziya; Frusher, Stewart; Buxton, Colin; Gardner, Caleb; Bird, Tomas
2016-01-01
Five annual capture-mark-recapture surveys on Jasus edwardsii were used to evaluate the effect of sample size and fishing effort on the precision of estimated survival probability. Datasets of different numbers of individual lobsters (ranging from 200 to 1,000 lobsters) were created by random subsampling from each annual survey. This process of random subsampling was also used to create 12 datasets of different levels of effort based on three levels of the number of traps (15, 30 and 50 traps per day) and four levels of the number of sampling-days (2, 4, 6 and 7 days). The most parsimonious Cormack-Jolly-Seber (CJS) model for estimating survival probability shifted from a constant model towards sex-dependent models with increasing sample size and effort. A sample of 500 lobsters or 50 traps used on four consecutive sampling-days was required for obtaining precise survival estimations for males and females, separately. Reduced sampling effort of 30 traps over four sampling days was sufficient if a survival estimate for both sexes combined was sufficient for management of the fishery. PMID:26990561
NASA Astrophysics Data System (ADS)
Willis, J. P.; Ramos-Ceja, M. E.; Muzzin, A.; Pacaud, F.; Yee, H. K. C.; Wilson, G.
2018-07-01
We present a comparison of two samples of z> 0.8 galaxy clusters selected using different wavelength-dependent techniques and examine the physical differences between them. We consider 18 clusters from the X-ray-selected XMM Large Scale Structure (LSS) distant cluster survey and 92 clusters from the optical-mid-infrared (MIR)-selected Spitzer Adaptation of the Red Sequence Cluster survey (SpARCS) cluster survey. Both samples are selected from the same approximately 9 sq deg sky area and we examine them using common XMM-Newton, Spitizer Wide-Area Infrared Extra-galactic (SWIRE) survey, and Canada-France-Hawaii Telescope Legacy Survey data. Clusters from each sample are compared employing aperture measures of X-ray and MIR emission. We divide the SpARCS distant cluster sample into three sub-samples: (i) X-ray bright, (ii) X-ray faint, MIR bright, and (iii) X-ray faint, MIR faint clusters. We determine that X-ray- and MIR-selected clusters display very similar surface brightness distributions of galaxy MIR light. In addition, the average location and amplitude of the galaxy red sequence as measured from stacked colour histograms is very similar in the X-ray- and MIR-selected samples. The sub-sample of X-ray faint, MIR bright clusters displays a distribution of brightest cluster galaxy-barycentre position offsets which extends to higher values than all other samples. This observation indicates that such clusters may exist in a more disturbed state compared to the majority of the distant cluster population sampled by XMM-LSS and SpARCS. This conclusion is supported by stacked X-ray images for the X-ray faint, MIR bright cluster sub-sample that display weak, centrally concentrated X-ray emission, consistent with a population of growing clusters accreting from an extended envelope of material.
40 CFR 761.353 - Second level of sample selection.
Code of Federal Regulations, 2012 CFR
2012-07-01
... reduction is to limit the amount of time required to manually cut up larger particles of the waste to pass through a 9.5 millimeter (mm) screen. (a) Selecting a portion of the subsample for particle size reduction... table to select one of these quarters. (b) Reduction of the particle size by the use of a 9.5 mm screen...
40 CFR 761.353 - Second level of sample selection.
Code of Federal Regulations, 2014 CFR
2014-07-01
... reduction is to limit the amount of time required to manually cut up larger particles of the waste to pass through a 9.5 millimeter (mm) screen. (a) Selecting a portion of the subsample for particle size reduction... table to select one of these quarters. (b) Reduction of the particle size by the use of a 9.5 mm screen...
40 CFR 761.353 - Second level of sample selection.
Code of Federal Regulations, 2013 CFR
2013-07-01
... reduction is to limit the amount of time required to manually cut up larger particles of the waste to pass through a 9.5 millimeter (mm) screen. (a) Selecting a portion of the subsample for particle size reduction... table to select one of these quarters. (b) Reduction of the particle size by the use of a 9.5 mm screen...
Social and cultural influences among Mexican border entrepreneurs.
Díaz Bretones, Francisco; Cappello, Héctor M; Garcia, Pedro A
2009-06-01
Social and cultural conditions (including U.S. border and inland influence, role models within the family, and educational background) which affect locus of control and achievement motivation among Mexican entrepreneurs were explored among 64 selected entrepreneurs in two Mexican towns, one on the Mexico-U.S. border, the other located inland. Analyses showed that the border subsample scored higher on External locus of control; however, in both subsamples the father was an important element in the locus of control variable and the entrepreneur status. No statistically significant mean difference was noted for achievement motivation. Practical applications and limitations are discussed.
Reducing seed dependent variability of non-uniformly sampled multidimensional NMR data
NASA Astrophysics Data System (ADS)
Mobli, Mehdi
2015-07-01
The application of NMR spectroscopy to study the structure, dynamics and function of macromolecules requires the acquisition of several multidimensional spectra. The one-dimensional NMR time-response from the spectrometer is extended to additional dimensions by introducing incremented delays in the experiment that cause oscillation of the signal along "indirect" dimensions. For a given dimension the delay is incremented at twice the rate of the maximum frequency (Nyquist rate). To achieve high-resolution requires acquisition of long data records sampled at the Nyquist rate. This is typically a prohibitive step due to time constraints, resulting in sub-optimal data records to the detriment of subsequent analyses. The multidimensional NMR spectrum itself is typically sparse, and it has been shown that in such cases it is possible to use non-Fourier methods to reconstruct a high-resolution multidimensional spectrum from a random subset of non-uniformly sampled (NUS) data. For a given acquisition time, NUS has the potential to improve the sensitivity and resolution of a multidimensional spectrum, compared to traditional uniform sampling. The improvements in sensitivity and/or resolution achieved by NUS are heavily dependent on the distribution of points in the random subset acquired. Typically, random points are selected from a probability density function (PDF) weighted according to the NMR signal envelope. In extreme cases as little as 1% of the data is subsampled. The heavy under-sampling can result in poor reproducibility, i.e. when two experiments are carried out where the same number of random samples is selected from the same PDF but using different random seeds. Here, a jittered sampling approach is introduced that is shown to improve random seed dependent reproducibility of multidimensional spectra generated from NUS data, compared to commonly applied NUS methods. It is shown that this is achieved due to the low variability of the inherent sensitivity of the random subset chosen from a given PDF. Finally, it is demonstrated that metrics used to find optimal NUS distributions are heavily dependent on the inherent sensitivity of the random subset, and such optimisation is therefore less critical when using the proposed sampling scheme.
A catalog of galaxy morphology and photometric redshift
NASA Astrophysics Data System (ADS)
Paul, Nicholas; Shamir, Lior
2018-01-01
Morphology carries important information about the physical characteristics of a galaxy. Here we used machine learning to produce a catalog of ~3,000,000 SDSS galaxies classified by their broad morphology into spiral and elliptical galaxies. Comparison of the catalog to Galaxy Zooshows that the catalog contains a subset of 1.7*10^6 galaxies classified with the same level of consistency as the debiased “superclean” sub-sample. In addition to the morphology, we also computed the photometric redshifts of the galaxies. Several pattern recognition algorithms and variable selection strategies were tested, and the best accuracy of mean absolute error of ~0.0062 was achieved by using random forest with a combination of manually and automatically selected variables. The catalog shows that for redshift lower than 0.085 galaxies that visually look spiral become more prevalent as the redshift gets higher. For redshift greater than 0.085 galaxies thatvisually look elliptical become more prevalent. The catalog as well as the source code used to produce it is publicly available athttps://figshare.com/articles/Morphology_and_photometric_redshift_catalog/4833593 .
Richardson, David S; Westerdahl, Helena
2003-12-01
The Great reed warbler (GRW) and the Seychelles warbler (SW) are congeners with markedly different demographic histories. The GRW is a normal outbred bird species while the SW population remains isolated and inbred after undergoing a severe population bottleneck. We examined variation at Major Histocompatibility Complex (MHC) class I exon 3 using restriction fragment length polymorphism, denaturing gradient gel electrophoresis and DNA sequencing. Although genetic variation was higher in the GRW, considerable variation has been maintained in the SW. The ten exon 3 sequences found in the SW were as diverged from each other as were a random sub-sample of the 67 sequences from the GRW. There was evidence for balancing selection in both species, and the phylogenetic analysis showing that the exon 3 sequences did not separate according to species, was consistent with transspecies evolution of the MHC.
Remote Sensing Image Change Detection Based on NSCT-HMT Model and Its Application.
Chen, Pengyun; Zhang, Yichen; Jia, Zhenhong; Yang, Jie; Kasabov, Nikola
2017-06-06
Traditional image change detection based on a non-subsampled contourlet transform always ignores the neighborhood information's relationship to the non-subsampled contourlet coefficients, and the detection results are susceptible to noise interference. To address these disadvantages, we propose a denoising method based on the non-subsampled contourlet transform domain that uses the Hidden Markov Tree model (NSCT-HMT) for change detection of remote sensing images. First, the ENVI software is used to calibrate the original remote sensing images. After that, the mean-ratio operation is adopted to obtain the difference image that will be denoised by the NSCT-HMT model. Then, using the Fuzzy Local Information C-means (FLICM) algorithm, the difference image is divided into the change area and unchanged area. The proposed algorithm is applied to a real remote sensing data set. The application results show that the proposed algorithm can effectively suppress clutter noise, and retain more detailed information from the original images. The proposed algorithm has higher detection accuracy than the Markov Random Field-Fuzzy C-means (MRF-FCM), the non-subsampled contourlet transform-Fuzzy C-means clustering (NSCT-FCM), the pointwise approach and graph theory (PA-GT), and the Principal Component Analysis-Nonlocal Means (PCA-NLM) denosing algorithm. Finally, the five algorithms are used to detect the southern boundary of the Gurbantunggut Desert in Xinjiang Uygur Autonomous Region of China, and the results show that the proposed algorithm has the best effect on real remote sensing image change detection.
Remote Sensing Image Change Detection Based on NSCT-HMT Model and Its Application
Chen, Pengyun; Zhang, Yichen; Jia, Zhenhong; Yang, Jie; Kasabov, Nikola
2017-01-01
Traditional image change detection based on a non-subsampled contourlet transform always ignores the neighborhood information’s relationship to the non-subsampled contourlet coefficients, and the detection results are susceptible to noise interference. To address these disadvantages, we propose a denoising method based on the non-subsampled contourlet transform domain that uses the Hidden Markov Tree model (NSCT-HMT) for change detection of remote sensing images. First, the ENVI software is used to calibrate the original remote sensing images. After that, the mean-ratio operation is adopted to obtain the difference image that will be denoised by the NSCT-HMT model. Then, using the Fuzzy Local Information C-means (FLICM) algorithm, the difference image is divided into the change area and unchanged area. The proposed algorithm is applied to a real remote sensing data set. The application results show that the proposed algorithm can effectively suppress clutter noise, and retain more detailed information from the original images. The proposed algorithm has higher detection accuracy than the Markov Random Field-Fuzzy C-means (MRF-FCM), the non-subsampled contourlet transform-Fuzzy C-means clustering (NSCT-FCM), the pointwise approach and graph theory (PA-GT), and the Principal Component Analysis-Nonlocal Means (PCA-NLM) denosing algorithm. Finally, the five algorithms are used to detect the southern boundary of the Gurbantunggut Desert in Xinjiang Uygur Autonomous Region of China, and the results show that the proposed algorithm has the best effect on real remote sensing image change detection. PMID:28587299
An Empirical Analysis of an Alternative Configuration of the Academic Motivation Scale
ERIC Educational Resources Information Center
Smith, Kenneth J.; Davy, Jeanette A.; Rosenberg, Donald L.
2012-01-01
The purpose of this study was to examine an alternative configuration of the Academic Motivation Scale (AMS), a psychometric instrument used as a measure of academic motivation in various academic environments. The analyses utilised data from a convenience sample of 2354 business students, broken into two random subsamples of 1177 cases.…
Can Financial Need Analysis be Simplified?
ERIC Educational Resources Information Center
Orwig, M. D.; Jones, Paul K.
This paper examines the problem of collecting financial data on aid applicants. A 10% sample (12,383) of student records was taken from the 1968-69 alphabetic history file for the ACT Student Need Analysis Service. Random sub-samples were taken in certain phases of the study. A relatively small number of financial variables were found to predict…
2017-03-01
53 ix LIST OF TABLES Table 1. Descriptive Statistics for Control Variables by... Statistics for Control Variables by Gender (Random Subsample with Complete Survey) ............................................................30 Table...empirical analysis. Chapter IV describes the summary statistics and results. Finally, Chapter V offers concluding thoughts, study limitations, and
The Construct of Creativity: Structural Model for Self-Reported Creativity Ratings
ERIC Educational Resources Information Center
Kaufman, James C.; Cole, Jason C.; Baer, John
2009-01-01
Several thousand subjects completed self-report questionnaires about their own creativity in 56 discrete domains. This sample was then randomly divided into three subsamples that were subject to factor analyses that compared an oblique model (with a set of correlated factors) and a hierarchical model (with a single second-order, or hierarchical,…
Developing a "Social Presence Scale" for E-Learning Environments
ERIC Educational Resources Information Center
Kilic Cakmak, Ebru; Cebi, Ayça; Kan, Adnan
2014-01-01
The purpose of the current study is to develop a "social presence scale" for e-learning environments. A systematic approach was followed for developing the scale. The scale was applied to 461 students registered in seven different programs at Gazi University. The sample was split into two subsamples on a random basis (n1 = 261; n2 =…
ERIC Educational Resources Information Center
Cui, Lixia; Lin, Wenwen; Oei, Tian P. S.
2011-01-01
This study investigated cross-cultural differences in the factor structure and psychometric properties of the Young Schema Questionnaire (short form; YSQ-SF). The participants were 712 Chinese undergraduate students. The total sample was randomly divided into two sub-samples. Exploratory Factor Analysis (EFA) was conducted on questionnaire results…
Elementary and Secondary Schools Civil Rights Survey, 1984. State Summaries.
ERIC Educational Resources Information Center
DBS Corp., Arlington, VA.
This 1984 survey was conducted to obtain data on the characteristics of public school students in the 50 states and the District of Columbia. The 3,510 school districts selected to participate were statistically sampled from approximately 16,000 U.S. school districts, and the schools within the selected districts were subsampled: (1) all special…
Elementary and Secondary Civil Rights Survey, 1984. National Summaries.
ERIC Educational Resources Information Center
DBS Corp., Arlington, VA.
This 1984 survey was conducted to obtain data on the characteristics of public school students in the 50 states and the District of Columbia. The 3,510 school districts selected to participate were statistically sampled from approximately 16,000 U.S. school districts, and the schools within the selected districts were subsampled: (1) all special…
VizieR Online Data Catalog: SAMI Galaxy Survey: gas streaming (Cecil+, 2016)
NASA Astrophysics Data System (ADS)
Cecil, G.; Fogarty, L. M. R.; Richards, S.; Bland-Hawthorn, J.; Lange, R.; Moffett, A.; Catinella, B.; Cortese, L.; Ho, I.-T.; Taylor, E. N.; Bryant, J. J.; Allen, J. T.; Sweet, S. M.; Croom, S. M.; Driver, S. P.; Goodwin, M.; Kelvin, L.; Green, A. W.; Konstantopoulos, I. S.; Owers, M. S.; Lawrence, J. S.; Lorente, N. P. F.
2016-08-01
From the first ~830 targets observed in the SGS, we selected 344 rotationally supported galaxies having enough gas to map their CSC. We rejected 8 whose inclination angle to us is too small (i<20°) to be established reliably by photometry, and those very strongly barred or in obvious interactions. Finally, we rejected those whose CSC would be smeared excessively by our PSF (Sect. 2.3.1) because of large inclination (i>71°), compact size, or observed in atrocious conditions, leaving 163 SGS GAMA survey sub-sample and 15 "cluster" sub-sample galaxies with discs. (3 data files).
Sampling in Developmental Science: Situations, Shortcomings, Solutions, and Standards.
Bornstein, Marc H; Jager, Justin; Putnick, Diane L
2013-12-01
Sampling is a key feature of every study in developmental science. Although sampling has far-reaching implications, too little attention is paid to sampling. Here, we describe, discuss, and evaluate four prominent sampling strategies in developmental science: population-based probability sampling, convenience sampling, quota sampling, and homogeneous sampling. We then judge these sampling strategies by five criteria: whether they yield representative and generalizable estimates of a study's target population, whether they yield representative and generalizable estimates of subsamples within a study's target population, the recruitment efforts and costs they entail, whether they yield sufficient power to detect subsample differences, and whether they introduce "noise" related to variation in subsamples and whether that "noise" can be accounted for statistically. We use sample composition of gender, ethnicity, and socioeconomic status to illustrate and assess the four sampling strategies. Finally, we tally the use of the four sampling strategies in five prominent developmental science journals and make recommendations about best practices for sample selection and reporting.
Sampling in Developmental Science: Situations, Shortcomings, Solutions, and Standards
Bornstein, Marc H.; Jager, Justin; Putnick, Diane L.
2014-01-01
Sampling is a key feature of every study in developmental science. Although sampling has far-reaching implications, too little attention is paid to sampling. Here, we describe, discuss, and evaluate four prominent sampling strategies in developmental science: population-based probability sampling, convenience sampling, quota sampling, and homogeneous sampling. We then judge these sampling strategies by five criteria: whether they yield representative and generalizable estimates of a study’s target population, whether they yield representative and generalizable estimates of subsamples within a study’s target population, the recruitment efforts and costs they entail, whether they yield sufficient power to detect subsample differences, and whether they introduce “noise” related to variation in subsamples and whether that “noise” can be accounted for statistically. We use sample composition of gender, ethnicity, and socioeconomic status to illustrate and assess the four sampling strategies. Finally, we tally the use of the four sampling strategies in five prominent developmental science journals and make recommendations about best practices for sample selection and reporting. PMID:25580049
Terry, Ana L; Cogswell, Mary E; Wang, Chia-Yih; Chen, Te-Ching; Loria, Catherine M; Wright, Jacqueline D; Zhang, Xinli; Lacher, David A; Merritt, Robert K; Bowman, Barbara A
2016-01-01
Background: Twenty-four–hour urine sodium excretion is recommended for monitoring population sodium intake. Because of concerns about participation and completion, sodium excretion has not been collected previously in US nationally representative surveys. Objective: We assessed the feasibility of implementing 24-h urine collections as part of a nationally representative survey. Design: We selected a random half sample of nonpregnant US adults aged 20–69 y in 3 geographic locations of the 2013 NHANES. Participants received explicit instructions, started and ended the urine collection in a urine study mobile examination center, and answered questions about their collection. Among those with a complete 24-h urine collection, a random one-half were asked to collect a second 24-h urine sample. Sodium, potassium, chloride, and creatinine excretion were analyzed. Results: The final NHANES examination response rate for adults aged 20–69 y in these 3 study locations was 71%. Of those examined (n = 476), 282 (59%) were randomly selected to participate in the 24-h urine collection. Of these, 212 persons [75% of those selected for 24-h urine collection; 53% (equal to 71% × 75% of those selected for the NHANES)] collected a complete initial 24-h specimen and 92 persons (85% of 108 selected) collected a second complete 24-h urine sample. More men than women completed an initial collection (P = 0.04); otherwise, completion did not vary by sociodemographic characteristics, body mass index, education, or employment status for either collection. Mean 24-h urine volume and sodium excretion were 1964 ± 1228 mL and 3657 ± 2003 mg, respectively, for the first 24-h urine sample, and 2048 ± 1288 mL and 3773 ± 1891 mg, respectively, for the second collection. Conclusion: Given the 53% final component response rate and 75% completion rate, 24-h urine collections were deemed feasible and implemented in the NHANES 2014 on a subsample of adults aged 20–69 y to assess population sodium intake. This study was registered at clinicaltrials.gov as NCT02723682. PMID:27413136
Precompetitive achievement goals, stress appraisals, emotions, and coping among athletes.
Nicholls, Adam R; Perry, John L; Calmeiro, Luis
2014-10-01
Grounded in Lazarus's (1991, 1999, 2000) cognitive-motivational-relational theory of emotions, we tested a model of achievement goals, stress appraisals, emotions, and coping. We predicted that precompetitive achievement goals would be associated with appraisals, appraisals with emotions, and emotions with coping in our model. The mediating effects of emotions among the overall sample of 827 athletes and two stratified random subsamples were also explored. The results of this study support our proposed model in the overall sample and the stratified subsamples. Further, emotion mediated the relationship between appraisal and coping. Mediation analyses revealed that there were indirect effects of pleasant and unpleasant emotions, which indicates the importance of examining multiple emotions to reveal a more accurate representation of the overall stress process. Our findings indicate that both appraisals and emotions are just as important in shaping coping.
ERIC Educational Resources Information Center
Balfanz, Robert; Legters, Nettie; West, Thomas C.; Weber, Lisa M.
2007-01-01
This article examines the extent to which adequate yearly progress (AYP) is a valid and reliable indicator of improvement in low-performing high schools. For a random subsample of 202 high schools, the authors investigate the school characteristics and the federal and state policy contexts that influence their AYP status. Logistic regression…
Composting Explosives/Organics Contaminated Soils
1986-05-01
29 144. Quantitation of C Trapped by Activated Carbon . ... 29 5. Preliminary Extraction Trials .... ........ ..... . 30 6. Tetryl Product...ppm (standard deviation 1892 ppm). All samples of soil from Letterkenny AD were pooled to yield one composite sample. Pooled samples from Louisiana...combustion efficiency, and counting efficiency. 4. Quantitation of 14 C Trapped by Activated Carbon Random subsamples of carbon from the air intake
ERIC Educational Resources Information Center
Sideridis, Georgios D.; Simos, Panagiotis; Mouzaki, Angeliki; Stamovlasis, Dimitrios
2016-01-01
The study explored the moderating role of rapid automatized naming (RAN) in reading achievement through a cusp-catastrophe model grounded on nonlinear dynamic systems theory. Data were obtained from a community sample of 496 second through fourth graders who were followed longitudinally over 2 years and split into 2 random subsamples (validation…
van der Oord, S; Ponsioen, A J G B; Geurts, H M; Ten Brink, E L; Prins, P J M
2014-11-01
This pilot study tested the short- and long-term efficacy (9 weeks follow-up) of an executive functioning (EF) remediation training with game elements for children with ADHD in an outpatient clinical setting, using a randomized controlled wait-list design. Furthermore, in a subsample, that is, those treated with methylphenidate, additive effects of the EF training were assessed. A total of 40 children (aged 8-12 years) were randomized to the EF training or wait-list. The training consisted of a 25-session training of inhibition, cognitive flexibility, and working memory. Treatment outcome was assessed by parent- and teacher-rated EF, ADHD, oppositional deviant disorder, and conduct disorder symptoms. Children in the EF training showed significantly more improvement than those in the wait-list condition on parent-rated EF and ADHD behavior in the total sample and in the subsample treated with methylphenidate. Effects were maintained at follow-up. This pilot study shows promising evidence for the efficacy of an EF training with game elements. © 2012 SAGE Publications.
Gitlin, Laura N.; Parisi, Jeanine; Huang, Jin; Winter, Laraine; Roth, David L.
2016-01-01
Purpose of study: Examine psychometric properties of Lawton’s Valuation of Life (VOL) scale, a measure of an older adults’ assessment of the perceived value of their lives; and whether ratings differ by race (White, Black/African American) and sex. Design and Methods: The 13-item VOL scale was administered at baseline in 2 separate randomized trials (Advancing Better Living for Elders, ABLE; Get Busy Get Better, GBGB) for a total of 527 older adults. Principal component analyses were applied to a subset of ABLE data (subsample 1) and confirmatory factor analyses were conducted on remaining data (subsample 2 and GBGB). Once the factor structure was identified and confirmed, 2 subscales were created, corresponding to optimism and engagement. Convergent validity of total and subscale scores were examined using measures of depressive symptoms, social support, control-oriented strategies, mastery, and behavioral activation. For discriminant validity, indices of health status, physical function, financial strain, cognitive status, and number of falls were examined. Results: Trial samples (ABLE vs. GBGB) differed by age, race, marital status, education, and employment. Principal component analysis on ABLE subsample 1 (n = 156) yielded two factors subsequently confirmed in confirmatory factor analyses on ABLE subsample 2 (n = 163) and GBGB sample (N = 208) separately. Adequate fit was found for the 2-factor model. Correlational analyses supported strong convergent and discriminant validity. Some statistically significant race and sex differences in subscale scores were found. Implications: VOL measures subjective appraisals of perceived value of life. Consisting of two interrelated subscales, it offers an efficient approach to ascertain personal attributions. PMID:26874189
Replicating cluster subtypes for the prevention of adolescent smoking and alcohol use.
Babbin, Steven F; Velicer, Wayne F; Paiva, Andrea L; Brick, Leslie Ann D; Redding, Colleen A
2015-01-01
Substance abuse interventions tailored to the individual level have produced effective outcomes for a wide variety of behaviors. One approach to enhancing tailoring involves using cluster analysis to identify prevention subtypes that represent different attitudes about substance use. This study applied this approach to better understand tailored interventions for smoking and alcohol prevention. Analyses were performed on a sample of sixth graders from 20 New England middle schools involved in a 36-month tailored intervention study. Most adolescents reported being in the Acquisition Precontemplation (aPC) stage at baseline: not smoking or not drinking and not planning to start in the next six months. For smoking (N=4059) and alcohol (N=3973), each sample was randomly split into five subsamples. Cluster analysis was performed within each subsample based on three variables: Pros and Cons (from Decisional Balance Scales), and Situational Temptations. Across all subsamples for both smoking and alcohol, the following four clusters were identified: (1) Most Protected (MP; low Pros, high Cons, low Temptations); (2) Ambivalent (AM; high Pros, average Cons and Temptations); (3) Risk Denial (RD; average Pros, low Cons, average Temptations); and (4) High Risk (HR; high Pros, low Cons, and very high Temptations). Finding the same four clusters within aPC for both smoking and alcohol, replicating the results across the five subsamples, and demonstrating hypothesized relations among the clusters with additional external validity analyses provide strong evidence of the robustness of these results. These clusters demonstrate evidence of validity and can provide a basis for tailoring interventions. Copyright © 2014. Published by Elsevier Ltd.
Replicating cluster subtypes for the prevention of adolescent smoking and alcohol use
Babbin, Steven F.; Velicer, Wayne F.; Paiva, Andrea L.; Brick, Leslie Ann D.; Redding, Colleen A.
2015-01-01
Introduction Substance abuse interventions tailored to the individual level have produced effective outcomes for a wide variety of behaviors. One approach to enhancing tailoring involves using cluster analysis to identify prevention subtypes that represent different attitudes about substance use. This study applied this approach to better understand tailored interventions for smoking and alcohol prevention. Methods Analyses were performed on a sample of sixth graders from 20 New England middle schools involved in a 36-month tailored intervention study. Most adolescents reported being in the Acquisition Precontemplation (aPC) stage at baseline: not smoking or not drinking and not planning to start in the next six months. For smoking (N= 4059) and alcohol (N= 3973), each sample was randomly split into five subsamples. Cluster analysis was performed within each subsample based on three variables: Pros and Cons (from Decisional Balance Scales), and Situational Temptations. Results Across all subsamples for both smoking and alcohol, the following four clusters were identified: (1) Most Protected (MP; low Pros, high Cons, low Temptations); (2) Ambivalent (AM; high Pros, average Cons and Temptations); (3) Risk Denial (RD; average Pros, low Cons, average Temptations); and (4) High Risk (HR; high Pros, low Cons, and very high Temptations). Conclusions Finding the same four clusters within aPC for both smoking and alcohol, replicating the results across the five subsamples, and demonstrating hypothesized relations among the clusters with additional external validity analyses provide strong evidence of the robustness of these results. These clusters demonstrate evidence of validity and can provide a basis for tailoring interventions. PMID:25222849
Trial publication after registration in ClinicalTrials.Gov: a cross-sectional analysis.
Ross, Joseph S; Mulvey, Gregory K; Hines, Elizabeth M; Nissen, Steven E; Krumholz, Harlan M
2009-09-01
ClinicalTrials.gov is a publicly accessible, Internet-based registry of clinical trials managed by the US National Library of Medicine that has the potential to address selective trial publication. Our objectives were to examine completeness of registration within ClinicalTrials.gov and to determine the extent and correlates of selective publication. We examined reporting of registration information among a cross-section of trials that had been registered at ClinicalTrials.gov after December 31, 1999 and updated as having been completed by June 8, 2007, excluding phase I trials. We then determined publication status among a random 10% subsample by searching MEDLINE using a systematic protocol, after excluding trials completed after December 31, 2005 to allow at least 2 y for publication following completion. Among the full sample of completed trials (n = 7,515), nearly 100% reported all data elements mandated by ClinicalTrials.gov, such as intervention and sponsorship. Optional data element reporting varied, with 53% reporting trial end date, 66% reporting primary outcome, and 87% reporting trial start date. Among the 10% subsample, less than half (311 of 677, 46%) of trials were published, among which 96 (31%) provided a citation within ClinicalTrials.gov of a publication describing trial results. Trials primarily sponsored by industry (40%, 144 of 357) were less likely to be published when compared with nonindustry/nongovernment sponsored trials (56%, 110 of 198; p<0.001), but there was no significant difference when compared with government sponsored trials (47%, 57 of 122; p = 0.22). Among trials that reported an end date, 75 of 123 (61%) completed prior to 2004, 50 of 96 (52%) completed during 2004, and 62 of 149 (42%) completed during 2005 were published (p = 0.006). Reporting of optional data elements varied and publication rates among completed trials registered within ClinicalTrials.gov were low. Without greater attention to reporting of all data elements, the potential for ClinicalTrials.gov to address selective publication of clinical trials will be limited. Please see later in the article for the Editors' Summary.
Chao, Pei-Kuang; Wang, Chun-Li; Chan, Hsiao-Lung
2012-03-01
Predicting response after cardiac resynchronization therapy (CRT) has been a challenge of cardiologists. About 30% of selected patients based on the standard selection criteria for CRT do not show response after receiving the treatment. This study is aimed to build an intelligent classifier to assist in identifying potential CRT responders by speckle-tracking radial strain based on echocardiograms. The echocardiograms analyzed were acquired before CRT from 26 patients who have received CRT. Sequential forward selection was performed on the parameters obtained by peak-strain timing and phase space reconstruction on speckle-tracking radial strain to find an optimal set of features for creating intelligent classifiers. Support vector machine (SVM) with a linear, quadratic, and polynominal kernel were tested to build classifiers to identify potential responders and non-responders for CRT by selected features. Based on random sub-sampling validation, the best classification performance is correct rate about 95% with 96-97% sensitivity and 93-94% specificity achieved by applying SVM with a quadratic kernel on a set of 3 parameters. The selected 3 parameters contain both indexes extracted by peak-strain timing and phase space reconstruction. An intelligent classifier with an averaged correct rate, sensitivity and specificity above 90% for assisting in identifying CRT responders is built by speckle-tracking radial strain. The classifier can be applied to provide objective suggestion for patient selection of CRT. Copyright © 2011 Elsevier B.V. All rights reserved.
Elementary and Secondary Civil Rights Survey, 1984. District Summary Volumes 1 and 2.
ERIC Educational Resources Information Center
DBS Corp., Arlington, VA.
This 1984 survey was conducted to obtain data on the characteristics of public school students in the 50 states and the District of Columbia. The 3,510 school districts selected to participate were statistically sampled from approximately 16,000 U.S. school districts, and the schools within the selected districts were subsampled: (1) all special…
Application and testing of a procedure to evaluate transferability of habitat suitability criteria
Thomas, Jeff A.; Bovee, Ken D.
1993-01-01
A procedure designed to test the transferability of habitat suitability criteria was evaluated in the Cache la Poudre River, Colorado. Habitat suitability criteria were developed for active adult and juvenile rainbow trout in the South Platte River, Colorado. These criteria were tested by comparing microhabitat use predicted from the criteria with observed microhabitat use by adult rainbow trout in the Cache la Poudre River. A one-sided X2 test, using counts of occupied and unoccupied cells in each suitability classification, was used to test for non-random selection for optimum habitat use over usable habitat and for suitable over unsuitable habitat. Criteria for adult rainbow trout were judged to be transferable to the Cache la Poudre River, but juvenile criteria (applied to adults) were not transferable. Random subsampling of occupied and unoccupied cells was conducted to determine the effect of sample size on the reliability of the test procedure. The incidence of type I and type II errors increased rapidly as the sample size was reduced below 55 occupied and 200 unoccupied cells. Recommended modifications to the procedure included the adoption of a systematic or randomized sampling design and direct measurement of microhabitat variables. With these modifications, the procedure is economical, simple and reliable. Use of the procedure as a quality assurance device in routine applications of the instream flow incremental methodology was encouraged.
Smith, Justin D; Dishion, Thomas J; Brown, Kimbree; Ramos, Karina; Knoble, Naomi B; Shaw, Daniel S; Wilson, Melvin N
2016-01-01
The valid and reliable assessment of fidelity is critical at all stages of intervention research and is particularly germane to interpreting the results of efficacy and implementation trials. Ratings of protocol adherence typically are reliable, but ratings of therapist competence are plagued by low reliability. Because family context and case conceptualization guide the therapist's delivery of interventions, the reliability of fidelity ratings might be improved if the coder is privy to client context in the form of an ecological assessment. We conducted a randomized experiment to test this hypothesis. A subsample of 46 families with 5-year-old children from a multisite randomized trial who participated in the feedback session of the Family Check-Up (FCU) intervention were selected. We randomly assigned FCU feedback sessions to be rated for fidelity to the protocol using the COACH rating system either after the coder reviewed the results of a recent ecological assessment or had not. Inter-rater reliability estimates of fidelity ratings were meaningfully higher for the assessment information condition compared to the no-information condition. Importantly, the reliability of the COACH mean score was found to be statistically significantly higher in the information condition. These findings suggest that the reliability of observational ratings of fidelity, particularly when the competence or quality of delivery is considered, could be improved by providing assessment data to the coders. Our findings might be most applicable to assessment-driven interventions, where assessment data explicitly guides therapist's selection of intervention strategies tailored to the family's context and needs, but they could also apply to other intervention programs and observational coding of context-dependent therapy processes, such as the working alliance.
Smith, Justin D.; Dishion, Thomas J.; Brown, Kimbree; Ramos, Karina; Knoble, Naomi B.; Shaw, Daniel S.; Wilson, Melvin N.
2015-01-01
The valid and reliable assessment of fidelity is critical at all stages of intervention research and is particularly germane to interpreting the results of efficacy and implementation trials. Ratings of protocol adherence typically are reliable, but ratings of therapist competence are plagued by low reliability. Because family context and case conceptualization guide the therapist's delivery of interventions, the reliability of fidelity ratings might be improved if the coder is privy to client context in the form of an ecological assessment. We conducted a randomized experiment to test this hypothesis. A subsample of 46 families with 5-year-old children from a multisite randomized trial who participated in the feedback session of the Family Check-Up (FCU) intervention were selected. We randomly assigned FCU feedback sessions to be rated for fidelity to the protocol using the COACH rating system either after the coder reviewed the results of a recent ecological assessment or had not. Inter-rater reliability estimates of fidelity ratings were meaningfully higher for the assessment information condition compared to the no-information condition. Importantly, the reliability of the COACH mean score was found to be statistically significantly higher in the information condition. These findings suggest that the reliability of observational ratings of fidelity, particularly when the competence or quality of delivery is considered, could be improved by providing assessment data to the coders. Our findings might be most applicable to assessment-driven interventions, where assessment data explicitly guides therapist's selection of intervention strategies tailored to the family's context and needs, but they could also apply to other intervention programs and observational coding of context-dependent therapy processes, such as the working alliance. PMID:26271300
Evaluation of bias and logistics in a survey of adults at increased risk for oral health decrements.
Gilbert, G H; Duncan, R P; Kulley, A M; Coward, R T; Heft, M W
1997-01-01
Designing research to include sufficient respondents in groups at highest risk for oral health decrements can present unique challenges. Our purpose was to evaluate bias and logistics in this survey of adults at increased risk for oral health decrements. We used a telephone survey methodology that employed both listed numbers and random digit dialing to identify dentate persons 45 years old or older and to oversample blacks, poor persons, and residents of nonmetropolitan counties. At a second stage, a subsample of the respondents to the initial telephone screening was selected for further study, which consisted of a baseline in-person interview and a clinical examination. We assessed bias due to: (1) limiting the sample to households with telephones, (2) using predominantly listed numbers instead of random digit dialing, and (3) nonresponse at two stages of data collection. While this approach apparently created some biases in the sample, they were small in magnitude. Specifically, limiting the sample to households with telephones biased the sample overall toward more females, larger households, and fewer functionally impaired persons. Using predominantly listed numbers led to a modest bias toward selection of persons more likely to be younger, healthier, female, have had a recent dental visit, and reside in smaller households. Blacks who were selected randomly at a second stage were more likely to participate in baseline data gathering than their white counterparts. Comparisons of the data obtained in this survey with those from recent national surveys suggest that this methodology for sampling high-risk groups did not substantively bias the sample with respect to two important dental parameters, prevalence of edentulousness and dental care use, nor were conclusions about multivariate associations with dental care recency substantively affected. This method of sampling persons at high risk for oral health decrements resulted in only modest bias with respect to the population of interest.
Gianneechini, R; Concha, C; Rivero, R; Delucci, I; López, J Moreno
2002-01-01
Twenty-nine dairy farms were selected to determine the incidence of clinical mastitis, prevalence of sub-clinical mastitis and bacterial aetiology in the West Littoral Region of Uruguay. In samples taken by the owner and frozen at -20°C during a week the incidence rate of clinical mastitis was determined as 1.2 cases per 100 cow-months at risk. Staphylococcus aureus was the most common isolated pathogen in 37.5% of 40 milk samples from clinical cases obtained in 1 month. No bacteria grew in the 32.5% of the total samples. A sub-sample including 1077 dairy cows from randomly selected farms was used to determine the prevalence of sub-clinical mastitis. These samples were taken on one visit to each farm. The prevalence was 52.4% on a cow basis and 26.7% on an udder quarter basis. In 55.1% of the quarters of the selected animals with more than 300 000 cells/ml there was no growth. The isolated pathogens from sub-clinical cases and their relative frequencies were: Staphylococcus aureus 62.8%, Streptococcus agalactiae 11.3%, Enterococcus sp. 8%, coagulase-negative staphylococci 7.4%, Streptococus uberis 6.4%, Streptococcus dysgalactiae 1.8%, Escherichia coli 1.5% and Staphylococcus hyicus coagulase-positive 0.6%. PMID:12831175
Carter, James L.; Resh, Vincent H.
2001-01-01
A survey of methods used by US state agencies for collecting and processing benthic macroinvertebrate samples from streams was conducted by questionnaire; 90 responses were received and used to describe trends in methods. The responses represented an estimated 13,000-15,000 samples collected and processed per year. Kicknet devices were used in 64.5% of the methods; other sampling devices included fixed-area samplers (Surber and Hess), artificial substrates (Hester-Dendy and rock baskets), grabs, and dipnets. Regional differences existed, e.g., the 1-m kicknet was used more often in the eastern US than in the western US. Mesh sizes varied among programs but 80.2% of the methods used a mesh size between 500 and 600 (mu or u)m. Mesh size variations within US Environmental Protection Agency regions were large, with size differences ranging from 100 to 700 (mu or u)m. Most samples collected were composites; the mean area sampled was 1.7 m2. Samples rarely were collected using a random method (4.7%); most samples (70.6%) were collected using "expert opinion", which may make data obtained operator-specific. Only 26.3% of the methods sorted all the organisms from a sample; the remainder subsampled in the laboratory. The most common method of subsampling was to remove 100 organisms (range = 100-550). The magnification used for sorting ranged from 1 (sorting by eye) to 30x, which results in inconsistent separation of macroinvertebrates from detritus. In addition to subsampling, 53% of the methods sorted large/rare organisms from a sample. The taxonomic level used for identifying organisms varied among taxa; Ephemeroptera, Plecoptera, and Trichoptera were generally identified to a finer taxonomic resolution (genus and species) than other taxa. Because there currently exists a large range of field and laboratory methods used by state programs, calibration among all programs to increase data comparability would be exceptionally challenging. However, because many techniques are shared among methods, limited testing could be designed to evaluate whether procedural differences affect the ability to determine levels of environmental impairment using benthic macroinvertebrate communities.
Resampling procedures to identify important SNPs using a consensus approach.
Pardy, Christopher; Motyer, Allan; Wilson, Susan
2011-11-29
Our goal is to identify common single-nucleotide polymorphisms (SNPs) (minor allele frequency > 1%) that add predictive accuracy above that gained by knowledge of easily measured clinical variables. We take an algorithmic approach to predict each phenotypic variable using a combination of phenotypic and genotypic predictors. We perform our procedure on the first simulated replicate and then validate against the others. Our procedure performs well when predicting Q1 but is less successful for the other outcomes. We use resampling procedures where possible to guard against false positives and to improve generalizability. The approach is based on finding a consensus regarding important SNPs by applying random forests and the least absolute shrinkage and selection operator (LASSO) on multiple subsamples. Random forests are used first to discard unimportant predictors, narrowing our focus to roughly 100 important SNPs. A cross-validation LASSO is then used to further select variables. We combine these procedures to guarantee that cross-validation can be used to choose a shrinkage parameter for the LASSO. If the clinical variables were unavailable, this prefiltering step would be essential. We perform the SNP-based analyses simultaneously rather than one at a time to estimate SNP effects in the presence of other causal variants. We analyzed the first simulated replicate of Genetic Analysis Workshop 17 without knowledge of the true model. Post-conference knowledge of the simulation parameters allowed us to investigate the limitations of our approach. We found that many of the false positives we identified were substantially correlated with genuine causal SNPs.
Hall, Andrew; Kirby, Helen
2010-04-01
A cluster survey of the age, sex and enrolment status of all school-age children 5-14 years old was undertaken in 2006 in a remote rural sub-district of the Northwest Frontier Province, Pakistan about a year after a devastating earthquake. Information was collected on the characteristics of children, their households and parents, and on reasons for non-enrolment. The health and nutritional status of a randomly selected child in each household was assessed and enrolled and non-enrolled children were compared by sex. A total of 2032 children were recorded in 925 households, 845 girls and 1187 boys, a sex ratio of 71 girls/100 boys. Half of all girls were not enrolled in school compared with a fifth of all boys. There was no common reason for non-enrolment and they differed between the sexes. The randomly selected children (n = 897) were moderately malnourished: 43% were stunted, 12% were thin and 46% were anaemic. 66% of a sub-sample of children (n = 269) had a low urinary iodine concentration, which could contribute to a low IQ and impaired hearing. There were no statistically significant differences in the nutritional status or health of non-enrolled and enrolled girls. These data contribute towards an understanding of how to improve the education and health of school-age children in a conservative, rural province of Pakistan. Copyright 2010 Elsevier Ltd. All rights reserved.
Energy Budget of Forming Clumps in Numerical Simulations of Collapsing Clouds
NASA Astrophysics Data System (ADS)
Camacho, Vianey; Vázquez-Semadeni, Enrique; Ballesteros-Paredes, Javier; Gómez, Gilberto C.; Fall, S. Michael; Mata-Chávez, M. Dolores
2016-12-01
We analyze the physical properties and energy balance of density enhancements in two SPH simulations of the formation, evolution, and collapse of giant molecular clouds. In the simulations, no feedback is included, so all motions are due either to the initial decaying turbulence or to gravitational contraction. We define clumps as connected regions above a series of density thresholds. The resulting full set of clumps follows the generalized energy equipartition relation, {σ }v/{R}1/2\\propto {{{Σ }}}1/2, where {σ }v is the velocity dispersion, R is the “radius,” and Σ is the column density. We interpret this as a natural consequence of gravitational contraction at all scales rather than virial equilibrium. Nevertheless, clumps with low Σ tend to show a large scatter around equipartition. In more than half of the cases, this scatter is dominated by external turbulent compressions that assemble the clumps rather than by small-scale random motions that would disperse them. The other half does actually disperse. Moreover, clump sub-samples selected by means of different criteria exhibit different scalings. Sub-samples with narrow Σ ranges follow Larson-like relations, although characterized by their respective values of Σ. Finally, we find that (I) clumps lying in filaments tend to appear sub-virial, (II) high-density cores (n≥slant {10}5 cm3) that exhibit moderate kinetic energy excesses often contain sink (“stellar”) particles and the excess disappears when the stellar mass is taken into account in the energy balance, and (III) cores with kinetic energy excess but no stellar particles are truly in a state of dispersal.
ERIC Educational Resources Information Center
Van der Kooy-Hofland, Verna A. C.; Bus, Adriana G.; Roskos, Kathleen
2012-01-01
Living Letters is an adaptive game designed to promote children's combining of how the proper name sounds with their knowledge of how the name looks. A randomized controlled trial (RCT) was used to experimentally test whether priming for attending to the sound-symbol relationship in the proper name can reduce the risk for developing reading…
Texture-adaptive hyperspectral video acquisition system with a spatial light modulator
NASA Astrophysics Data System (ADS)
Fang, Xiaojing; Feng, Jiao; Wang, Yongjin
2014-10-01
We present a new hybrid camera system based on spatial light modulator (SLM) to capture texture-adaptive high-resolution hyperspectral video. The hybrid camera system records a hyperspectral video with low spatial resolution using a gray camera and a high-spatial resolution video using a RGB camera. The hyperspectral video is subsampled by the SLM. The subsampled points can be adaptively selected according to the texture characteristic of the scene by combining with digital imaging analysis and computational processing. In this paper, we propose an adaptive sampling method utilizing texture segmentation and wavelet transform (WT). We also demonstrate the effectiveness of the sampled pattern on the SLM with the proposed method.
The observational case for Jupiter being a typical massive planet.
Lineweaver, Charles H; Grether, Daniel
2002-01-01
We identify a subsample of the recently detected extrasolar planets that is minimally affected by the selection effects of the Doppler detection method. With a simple analysis we quantify trends in the surface density of this subsample in the period-Msin(i) plane. A modest extrapolation of these trends puts Jupiter in the most densely occupied region of this parameter space, thus indicating that Jupiter is a typical massive planet rather than an outlier. Our analysis suggests that Jupiter is more typical than indicated by previous analyses. For example, instead of MJup mass exoplanets being twice as common as 2 MJup exoplanets, we find they are three times as common.
[Factor structure validity of the social capital scale used at baseline in the ELSA-Brasil study].
Souto, Ester Paiva; Vasconcelos, Ana Glória Godoi; Chor, Dora; Reichenheim, Michael E; Griep, Rosane Härter
2016-07-21
This study aims to analyze the factor structure of the Brazilian version of the Resource Generator (RG) scale, using baseline data from the Brazilian Longitudinal Health Study in Adults (ELSA-Brasil). Cross-validation was performed in three random subsamples. Exploratory factor analysis using exploratory structural equation models was conducted in the first two subsamples to diagnose the factor structure, and confirmatory factor analysis was used in the third to corroborate the model defined by the exploratory analyses. Based on the 31 initial items, the model with the best fit included 25 items distributed across three dimensions. They all presented satisfactory convergent validity (values greater than 0.50 for the extracted variance) and precision (values greater than 0.70 for compound reliability). All factor correlations were below 0.85, indicating full discriminative factor validity. The RG scale presents acceptable psychometric properties and can be used in populations with similar characteristics.
Chasens, Eileen R; Twerski, Sarah R; Yang, Kyeongra; Umlauf, Mary Grace
2010-01-01
The 2007 Sleep in America poll, a random-sample telephone survey, provided data for this study of sleep in community-dwelling women aged 40 to 60 years. The majority of the respondents were post- or perimenopausal, overweight, married or living with someone, and reported good health. A subsample (20%) reported sleepiness that consistently interfered with daily life; the sleepy subsample reported more symptoms of insomnia, restless legs syndrome, obstructive sleep apnea, depression and anxiety, as well as more problems with health-promoting behaviors, drowsy driving, job performance, household duties, and personal relationships. Hierarchical regression showed that sleepiness along with depressive symptoms, medical comorbidities, obesity, and lower education were associated with poor self-rated health, whereas menopause status (pre-, peri- or post-) was not. These results suggest that sleep disruptions and daytime sleepiness negatively affect the daily life of midlife women.
Galaxy Properties Across and Through the 6dFGS Fundamental Plane
NASA Astrophysics Data System (ADS)
Springob, Chris M.; Magoulas, C.; Proctor, R.; Colless, M.; Jones, D. H.; Kobayashi, C.; Campbell, L.; Lucey, J.; Mould, J.; Merson, A.
2011-05-01
The 6dF Galaxy Survey (6dFGS) is an all southern sky galaxy survey, including 125,000 redshifts and a Fundamental Plane (FP) subsample of 10,000 peculiar velocities, making it the largest peculiar velocity sample to date. We have developed a robust procedure for fitting the FP, performing a maximum likelihood fit to a tri-variate Gaussian. We have subsequently examined the variation of a variety of properties across and through the FP, including environment, morphology, metallicity, alpha-enhancement, and stellar age. We find little variation in the FP with global environment. Some variation of morphology is found along the plane, though this is likely a consequence of selection effects. Elemental abundances are found to vary both across and through the FP. The parameter that varies most directly through the FP is stellar age. We find that galaxies with stellar populations with average ages older than 3 Gyr occupy a thinner FP than those younger than 3 Gyr. Thus, a modest improvement in distance errors is realized if one divides the sample into subsamples segregated by age, and fits the FP of each subsample independently.
ERIC Educational Resources Information Center
You, Sukkyung; O'Malley, Meagan D.; Furlong, Michael J.
2014-01-01
A brief 15-item version of the California School Climate Scale (Brief-CSCS) is presented to fill a need for a measure that could be used for periodic monitoring of school personnel's general perception of the climate of their school campus. From a sample of 81,261 California school personnel, random subsamples of 2,400 teachers and 2,400…
ERIC Educational Resources Information Center
Recklitis, Christopher J.; Parsons, Susan K.; Shih, Mei-Chiung; Mertens, Ann; Robison, Leslie L.; Zeltzer, Lonnie
2006-01-01
The factor structure of the Brief Symptom Inventory--18 (BSI-18; L. R. Derogatis, 2000) was investigated in a sample of adult survivors of childhood cancer enrolled in the Childhood Cancer Survivor Study (CCSS; N = 8,945). An exploratory factor analysis with a randomly chosen subsample supported a 3-factor structure closely corresponding to the 3…
Comparison of Abuse Experiences of Rural and Urban African American Women During Perinatal Period
Bhandari, Shreya; Bullock, Linda F. C.; Richardson, Jeanita W.; Kimeto, Pamela; Campbell, Jacquelyn C.; Sharps, Phyllis W.
2015-01-01
A subsample of 12 African American women (6 urban and 6 rural) were selected from a larger longitudinal, randomized control trial, Domestic Violence Enhanced Home Visitation (DOVE-R01 900903 National Institute of Nursing Research [NINR]/National Institutes of Health [NIH]). All African American women were chosen to control for any racial- and/or race-related cultural differences that may exist among women across geographical areas. The experiences of abuse during the perinatal period are drawn from in-depth interviews conducted at five points in time during pregnancy and the post-partum period. The analysis describes three major themes that highlight the similarities and differences among rural and urban women. The main themes found were (1) types of abuse, (2) location of abuse, and (3) response to abuse. In addition, two sub-themes (a) defiance and compliance and (b) role of children were also identified. Implications for universal screening for women of reproductive age, safer gun laws, and the need for further research are discussed. PMID:25315478
Shen, Chung-Wei; Chen, Yi-Hau
2018-03-13
We propose a model selection criterion for semiparametric marginal mean regression based on generalized estimating equations. The work is motivated by a longitudinal study on the physical frailty outcome in the elderly, where the cluster size, that is, the number of the observed outcomes in each subject, is "informative" in the sense that it is related to the frailty outcome itself. The new proposal, called Resampling Cluster Information Criterion (RCIC), is based on the resampling idea utilized in the within-cluster resampling method (Hoffman, Sen, and Weinberg, 2001, Biometrika 88, 1121-1134) and accommodates informative cluster size. The implementation of RCIC, however, is free of performing actual resampling of the data and hence is computationally convenient. Compared with the existing model selection methods for marginal mean regression, the RCIC method incorporates an additional component accounting for variability of the model over within-cluster subsampling, and leads to remarkable improvements in selecting the correct model, regardless of whether the cluster size is informative or not. Applying the RCIC method to the longitudinal frailty study, we identify being female, old age, low income and life satisfaction, and chronic health conditions as significant risk factors for physical frailty in the elderly. © 2018, The International Biometric Society.
Braun, Christopher L.; Wilson, Jennifer T.; Van Metre, Peter C.; Weakland, Rhonda J.; Fosness, Ryan L.; Williams, Marshall L.
2012-01-01
Fifty subsamples from 15 cores were analyzed for major and trace elements. Concentrations of trace elements were low, with respect to sediment quality guidelines, in most cores. Typically, major and trace element concentrations were lower in the subsamples collected from the Snake River compared to those collected from the Clearwater River, the confluence of the Snake and Clearwater Rivers, and Lower Granite Reservoir. Generally, lower concentrations of major and trace elements were associated with coarser sediments (larger than 0.0625 millimeter) and higher concentrations of major and trace elements were associated with finer sediments (smaller than 0.0625 millimeter).
SELECTED PESTICIDE RESIDUES AND METABOLITES IN URINE FROM A SURVEY OF THE U.S. GENERAL POPULATION
Residues of toxic chemicals in human tissues and fluids can be important indicators of exposure. Urine collected from a subsample of the second National Health and Nutrition Examination Survey was analyzed for organochlorine, organophosphorus, and chlorophenoxy pesticides or the...
Improving Ramsey spectroscopy in the extreme-ultraviolet region with a random-sampling approach
DOE Office of Scientific and Technical Information (OSTI.GOV)
Eramo, R.; Bellini, M.; European Laboratory for Non-linear Spectroscopy
2011-04-15
Ramsey-like techniques, based on the coherent excitation of a sample by delayed and phase-correlated pulses, are promising tools for high-precision spectroscopic tests of QED in the extreme-ultraviolet (xuv) spectral region, but currently suffer experimental limitations related to long acquisition times and critical stability issues. Here we propose a random subsampling approach to Ramsey spectroscopy that, by allowing experimentalists to reach a given spectral resolution goal in a fraction of the usual acquisition time, leads to substantial improvements in high-resolution spectroscopy and may open the way to a widespread application of Ramsey-like techniques to precision measurements in the xuv spectral region.
Widen, Elizabeth M; Bentley, Margaret E; Chasela, Charles S; Kayira, Dumbani; Flax, Valerie L; Kourtis, Athena P; Ellington, Sascha R; Kacheche, Zebrone; Tegha, Gerald; Jamieson, Denise J; van der Horst, Charles M; Allen, Lindsay H; Shahab-Ferdows, Setareh; Adair, Linda S
2015-01-01
Objective In resource-limited settings without safe alternatives to breastfeeding, the WHO recommends exclusive breastfeeding and antiretroviral (ARV) prophylaxis. Given the high prevalence of anemia among HIV-infected women, mothers and their infants (via fetal iron accretion) may be at risk of iron deficiency. We assessed the effects of maternal micronutrient-fortified lipid-based nutrient supplements (LNS) and maternal ARV treatment or infant ARV prophylaxis on maternal and infant iron status during exclusive breastfeeding from birth to 24 weeks. Methods The Breastfeeding, Antiretrovirals, and Nutrition Study was a randomized controlled trial conducted in Lilongwe, Malawi from 2004-2010. HIV-infected mothers (CD4>200 cells/ul) and their infants were randomly assigned to 28-week interventions: maternal-LNS/maternal-ARV (n=424), maternal-LNS/infant-ARV (n=426), maternal-LNS (n=334), maternal-ARV (n=425), infant-ARV (n=426), or control (n=334). Longitudinal models tested intervention effects on hemoglobin (Hb). In a subsample (n=537) with multiple iron indicators, intervention effects on Hb, transferrin receptors (TfR) and ferritin were tested with linear and Poisson regression. Results In longitudinal models, LNS effects on maternal and infant Hb were minimal. In subsample mothers, maternal ARVs were associated with tissue iron depletion (TfR>8.3 mg/L) (Risk ratio (RR): 3.1, p<0.01), but not in ARV-treated mothers receiving LNS (p=0.17). LNS without ARVs, was not associated with iron deficiency or anemia (p>0.1). In subsample infants, interventions were not associated with impaired iron status (all p-values>0.1). Conclusions Maternal ARV treatment with protease inhibitors is associated with maternal tissue iron depletion; but LNS mitigates adverse effects. ARVs do not appear to influence infant iron status; however, extended use needs to be evaluated. PMID:25723140
Ohneberg, K; Wolkewitz, M; Beyersmann, J; Palomar-Martinez, M; Olaechea-Astigarraga, P; Alvarez-Lerma, F; Schumacher, M
2015-01-01
Sampling from a large cohort in order to derive a subsample that would be sufficient for statistical analysis is a frequently used method for handling large data sets in epidemiological studies with limited resources for exposure measurement. For clinical studies however, when interest is in the influence of a potential risk factor, cohort studies are often the first choice with all individuals entering the analysis. Our aim is to close the gap between epidemiological and clinical studies with respect to design and power considerations. Schoenfeld's formula for the number of events required for a Cox' proportional hazards model is fundamental. Our objective is to compare the power of analyzing the full cohort and the power of a nested case-control and a case-cohort design. We compare formulas for power for sampling designs and cohort studies. In our data example we simultaneously apply a nested case-control design with a varying number of controls matched to each case, a case cohort design with varying subcohort size, a random subsample and a full cohort analysis. For each design we calculate the standard error for estimated regression coefficients and the mean number of distinct persons, for whom covariate information is required. The formula for the power of a nested case-control design and the power of a case-cohort design is directly connected to the power of a cohort study using the well known Schoenfeld formula. The loss in precision of parameter estimates is relatively small compared to the saving in resources. Nested case-control and case-cohort studies, but not random subsamples yield an attractive alternative for analyzing clinical studies in the situation of a low event rate. Power calculations can be conducted straightforwardly to quantify the loss of power compared to the savings in the num-ber of patients using a sampling design instead of analyzing the full cohort.
A System Approach to Navy Medical Education and Training. Appendix 18. Radiation Technician.
1974-08-31
attrition was forecast to approximate twenty percent, final sample and sub-sample sizes were adjusted accordingly. Stratified random sampling... HYPERTENSIVE INTRAVENOUS PYELOGRAMS 2 ITAKE RENAL LOOPOGRAMI I 3 ITAKE CIXU, I.Eo CONSTANT INFUSION 4 10 RENAL SPLIT FUNCTION TEST, E.G. STAMEY 5...ITAKE PORTAL FILM OF AREA BEING TREATED WITH COBALT 32 [INFORM DOCTOR OF UNEXPECTED X-RAY FINDINGS 33 IREAD X-RAY FILMS FOR TECHNICAL ADEQUACY 34
Prevalence of Falls in an Urban Community-Dwelling Older Population of Cape Town, South Africa.
Zimba Kalula, S; Ferreira, M; Swingler, G; Badri, M; Aihie Sayer, A
2015-12-01
Falls are a major cause of disability and mortality in older adults. Studies on falls in this population have mainly been conducted in high income countries, and scant attention has been given to the problem in low and middle income countries, including South Africa. The aim of the study was to establish a rate for falls in older adults in South Africa. A cross-sectional survey with a 12-month follow-up survey. Three purposively selected suburbs of Cape Town: Plumstead, Wynberg Central and Gugulethu. Eight hundred and thirty seven randomly sampled ambulant community-dwelling subjects aged ≥ 65 years grouped according to ethnicity in three sub-samples: black Africans, coloureds (people of mixed ancestry) and whites. Data were collected on socio-demographic and health characteristics, and history of falls using a structured questionnaire and a protocol for physical assessments and measurements. Of the total baseline (n=837) and follow-up (n=632) survey participants, 76.5% and 77.2 % were females with a mean (S.D) age of 74 years (6.4) and 75 years (6.2), respectively. Rates of 26.4% and 21.9% for falls and of 11% and 6.3% for recurrent falls, respectively, were calculated at baseline and follow-up. Fall rates differed by ethnic sub-sample at baseline: whites 42 %, coloureds 34.4% and black Africans 6.4 % (p=0.0005). Rates of 236, 406 and 354 falls per 1000 person years were calculated for men, women and both genders, respectively. Recurrent falls were more common in women than in men. Falls are a significant problem in older adults in South Africa. Effective management of falls and falls prevention strategies for older people in South Africa, need to be developed and implemented.
Astrøm, Anne Nordrehaug; Okullo, I
2004-12-01
This study addressed three questions: What is the power of the Theory of Planned Behavior (TPB) in predicting adolescents' intended and self-perceived consumption of non-milk extrinsic sugars using a non-intervention prospective approach? To what extent do the TPB constructs change across time following adolescents' mere exposure to an oral health survey? Do changes in self-perceived sugar consumption at follow-up associate with changes in behavioral intention as predicted by the TPB? A survey was conducted in Kampala (urban) and Lira (rural) and 1146 secondary school students completed questionnaires assessing the TPB at school (Time 1). A random sub-sample of 415 students was selected from the original survey of which 372 students were examined clinically. After 3 months (Time 2), the questionnaire was administered a second time in the sub-sample. All analyses are based on the number of students who participated on both survey occasions, n = 372. Attitudes and perceived behavioral control predicted intended sugar consumption at Time 1 and Time 2, accounting for 58% (DeltaR(2) = 0.58) and 19% (DeltaR(2) = 0.19) of the variance, respectively. Time 1 intention provided significant prediction of Time 2 self-perceived sugar consumption with DeltaR(2) = 0.5. Adolescents with high-caries experience more than their counterparts with low, changed towards weaker intentions and less frequent sugar consumption across the survey period. Mean sugar consumption scores changed from 2.6 to 2.7 (ns), 3.1 to 2.6 (P < 0.001) and 2.3 to 3.2 (P < 0.001) among adolescents who, respectively, remained stable, increased and decreased their intentions across time. This study supports the validity of the TPB in predicting intended and self-perceived sugar consumption prospectively.
Sodium in the Finnish diet: 20-year trends in urinary sodium excretion among the adult population.
Laatikainen, T; Pietinen, P; Valsta, L; Sundvall, J; Reinivuo, H; Tuomilehto, J
2006-08-01
High sodium intake increases the risk of cardiovascular diseases and may also be associated with higher rates of stomach cancer, asthma disorders and infections. In Finland, cross-sectional population surveys to monitor cardiovascular risk factors have been carried out since the 1970s. The main aim of this paper is to present trends in urinary sodium and potassium excretion from 1979 to 2002. Cross-sectional population surveys on cardiovascular risk factors. Surveys were carried out in Finland in 1979, 1982, 1987 and 2002 in four geographical areas: North Karelia, the Kuopio area, Southwestern Finland and the Helsinki area. For each survey a random sample stratified by age and sex was drawn from the population register. In this analysis, participants of urine collection subsamples aged 25-64 years (n = 4648) were included. A 24-h urinary collection was carried out in subsamples (n = 2218-2487) in connection with population risk factor surveys. Urinary sodium and potassium concentrations were analyzed in the same laboratory throughout, using a flame photometer in 1979, 1982 and 1987 and an ion-selective electrode in 2002. Between 1979 and 2002 urinary sodium excretion in Finland decreased from over 220 to less than 170 mmol/day among men and from nearly 180 to less than 130 mmol/day among women. Although potassium excretion decreased somewhat as well, the decrease in sodium-potassium molar ratio was also significant. The 24-h urinary sodium excretion in Finland has decreased significantly during the last 20 years. However, excretion levels are still considerably higher than recommendations. A further decrease in sodium intake remains a goal for the Finnish food industry and consumers. All surveys were funded by the National Public Health Institute in Finland.
Two-dimensional Topology of the Sloan Digital Sky Survey
NASA Astrophysics Data System (ADS)
Hoyle, Fiona; Vogeley, Michael S.; Gott, J. Richard, III; Blanton, Michael; Tegmark, Max; Weinberg, David H.; Bahcall, N.; Brinkmann, J.; York, D.
2002-12-01
We present the topology of a volume-limited sample of 11,884 galaxies, selected from an apparent magnitude limited sample of over 100,000 galaxies observed as part of the Sloan Digital Sky Survey (SDSS). The data currently cover three main regions on the sky: one in the Galactic north and one in the south, both at zero degrees declination, and one area in the north at higher declination. Each of these areas covers a wide range of survey longitude but a narrow range of survey latitude, allowing the two-dimensional genus to be measured. The genus curves of the SDSS subsamples are similar, after appropriately normalizing these measurements for the different areas. We sum the genus curves from the three areas to obtain the total genus curve of the SDSS. The total curve has a shape similar to the genus curve derived from mock catalogs drawn from the Hubble volume ΛCDM simulation and is similar to that of a Gaussian random field. Likewise, comparison with the genus of the Two-Degree Field Galaxy Redshift Survey, after normalization for the difference in area, reveals remarkable similarity in the topology of these samples. We test for the effects of galaxy-type segregation by splitting the SDSS data into thirds, based on the u*-r* colors of the galaxies, and measure the genus of the reddest and bluest subsamples. This red/blue split in u*-r* is essentially a split by morphology, as explained by Strateva and coworkers. We find that the genus curve for the reddest galaxies exhibits a ``meatball'' shift of the topology-reflecting the concentration of red galaxies in high-density regions-compared to the bluest galaxies and the full sample, in agreement with predictions from simulations.
Phillips, Siobhan M; McAuley, Edward
2013-05-01
Physical activity is associated with reductions in fatigue in breast cancer survivors. However, mechanisms underlying this relationship are not well-understood. The purpose of this study was to longitudinally test a model examining the role of self-efficacy and depression as potential mediators of the relationship between physical activity and fatigue in a sample of breast cancer survivors using both self-report and objective measures of physical activity. All participants (N = 1,527) completed self-report measures of physical activity, self-efficacy, depression, and fatigue at baseline and 6 months. A subsample was randomly selected to wear an accelerometer at both time points. It was hypothesized that physical activity indirectly influences fatigue via self-efficacy and depression. Relationships among model constructs were examined over the 6-month period using panel analysis within a covariance modeling framework. The hypothesized model provided a good model-data fit (χ(2) = 599.66, df = 105, P ≤ 0.001; CFI = 0.96; SRMR = 0.02) in the full sample when controlling for covariates. At baseline, physical activity indirectly influenced fatigue via self-efficacy and depression. These relationships were also supported across time. In addition, the majority of the hypothesized relationships were supported in the subsample with accelerometer data (χ(2) = 387.48, df = 147, P ≤ 0.001, CFI = 0.94, SRMR = 0.04). This study provides evidence to suggest the relationship between physical activity and fatigue in breast cancer survivors may be mediated by more proximal, modifiable outcomes of physical activity participation. Recommendations are made relative to future applications and research concerning these relationships.
Phillips, Siobhan M; Lloyd, Gillian R; Awick, Elizabeth A; McAuley, Edward
2017-09-01
Many breast cancer survivors report cancer and cancer treatment-associated cognitive change. However, very little is known about the relationship between physical activity and subjective memory impairment (SMI) in this population. The purpose of this study is to examine the relationship between physical activity and SMI and longitudinally test a model examining the role of self-efficacy, fatigue and distress as potential mediators. Post-treatment breast cancer survivors (N = 1477) completed measures of physical activity, self-efficacy, distress (depression, concerns about recurrence, perceived stress, anxiety), fatigue and SMI at baseline and 6-month follow-up. A subsample (n = 362) was randomly selected to wear an accelerometer. It was hypothesized that physical activity indirectly influences SMI via exercise self-efficacy, distress and fatigue. Relationships were examined using panel analysis within a covariance modeling framework. The hypothesized model provided a good fit in the full sample (χ 2 = 1462.5, df = 469, p = <0.001; CFI = 0.96; SRMR = 0.04) and the accelerometer subsample (χ2 = 961.8, df = 535, p = <0.001, CFI = 0.94, SRMR = 0.05) indicating increased physical activity is indirectly associated with reduction in SMI across time, via increased exercise self-efficacy and reduced distress and fatigue. Higher levels of physical activity, lower levels of fatigue and distress and higher exercise self-efficacy may play an important role in understanding SMI in breast cancer survivors across time. Future research is warranted to replicate and explore these relationships further. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
Ito, Masaya; Bentley, Kate H.; Oe, Yuki; Nakajima, Shun; Fujisato, Hiroko; Kato, Noriko; Miyamae, Mitsuhiro; Kanie, Ayako; Horikoshi, Masaru; Barlow, David H.
2015-01-01
Background The Overall Depression Severity and Impairment Scale (ODSIS) is a brief, five-item measure for assessing the frequency and intensity of depressive symptoms, as well as functional impairments in pleasurable activities, work or school, and interpersonal relationships due to depression. Although this scale is expected to be useful in various psychiatric and mental health settings, the reliability, validity, and interpretability have not yet been fully examined. This study was designed to examine the reliability, factorial, convergent, and discriminant validity of a Japanese version of the ODSIS, as well as its ability to distinguish between individuals with and without a major depressive disorder diagnosis. Methods From a pool of registrants at an internet survey company, 2830 non-clinical and clinical participants were selected randomly (619 with major depressive disorder, 619 with panic disorder, 576 with social anxiety disorder, 645 with obsessive–compulsive disorder, and 371 non-clinical panelists). Participants were asked to respond to the ODSIS and conventional measures of depression, functional impairment, anxiety, neuroticism, satisfaction with life, and emotion regulation. Results Exploratory and confirmatory factor analysis of three split subsamples indicated the unidimensional factor structure of ODSIS. Multi-group confirmatory factor analysis showed invariance of factor loadings between non-clinical and clinical subsamples. The ODSIS also showed excellent internal consistency and test–retest intraclass correlation coefficients. Convergence and discriminance of the ODSIS with various measures were in line with our expectations. Receiver operating characteristic curve analyses showed that the ODSIS was able to detect a major depressive syndrome accurately. Conclusions This study supports the reliability and validity of ODSIS in a non-western population, which can be interpreted as demonstrating cross-cultural validity. PMID:25874558
Sampling Frequency Optimisation and Nonlinear Distortion Mitigation in Subsampling Receiver
NASA Astrophysics Data System (ADS)
Castanheira, Pedro Xavier Melo Fernandes
Subsampling receivers utilise the subsampling method to down convert signals from radio frequency (RF) to a lower frequency location. Multiple signals can also be down converted using the subsampling receiver, but using the incorrect subsampling frequency could result in signals aliasing one another after down conversion. The existing method for subsampling multiband signals focused on down converting all the signals without any aliasing between the signals. The case considered initially was a dual band signal, and then it was further extended to a more general multiband case. In this thesis, a new method is proposed with the assumption that only one signal is needed to not overlap the other multiband signals that are down converted at the same time. The proposed method will introduce unique formulas using the said assumption to calculate the valid subsampling frequencies, ensuring that the target signal is not aliased by the other signals. Simulation results show that the proposed method will provide lower valid subsampling frequencies for down conversion compared to the existing methods.
Nicotine craving: ERPs correlates after VR exposure to smoking cues.
Gamito, Pedro; Oliveira, Jorge; Baptista, André; Morais, Diogo; Lopes, Paulo; Saraiva, Tomaz; Rosa, Pedro; Santos, Nuno; Soares, Fábio; Sottomayor, Catarina; Barata, Filipa
2012-01-01
Even though it is diminishing in Europe, smoking is still a serious health problem. The craving of Nicotine is one of the hardest behaviours to tackle when a smoking cessation programme is implemented. Following on previous work [1], which aimed at evaluating the possibility of inducing smoking craving in smokers using a VR platform, the present study was devised to assess the role of craving in cognitive processing through event related potentials (ERP). From an initial sample of 89 university students (smokers and non-smokers), which was randomly exposed to VR smoking cues and VR non-smoking cue scenarios, a subsample of 13 smokers and non-smokers was drawn. This subsample (M = 23.08; SD = 4.39), which had previously been immersed in the VR smoking cues environment, was presented to a rapid (1 sec) serial of smoking and neutral images. Data on brain activity was recorded through an EEG during this task to further estimate ERPs. When compared to non-smokers, smokers showed higher frontal activation when watching smoking related images.
Predicting safety culture: the roles of employer, operations manager and safety professional.
Wu, Tsung-Chih; Lin, Chia-Hung; Shiau, Sen-Yu
2010-10-01
This study explores predictive factors in safety culture. In 2008, a sample 939 employees was drawn from 22 departments of a telecoms firm in five regions in central Taiwan. The sample completed a questionnaire containing four scales: the employer safety leadership scale, the operations manager safety leadership scale, the safety professional safety leadership scale, and the safety culture scale. The sample was then randomly split into two subsamples. One subsample was used for measures development, one for the empirical study. A stepwise regression analysis found four factors with a significant impact on safety culture (R²=0.337): safety informing by operations managers; safety caring by employers; and safety coordination and safety regulation by safety professionals. Safety informing by operations managers (ß=0.213) was by far the most significant predictive factor. The findings of this study provide a framework for promoting a positive safety culture at the group level. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.
A radial measurement of the galaxy tidal alignment magnitude with BOSS data
NASA Astrophysics Data System (ADS)
Martens, Daniel; Hirata, Christopher M.; Ross, Ashley J.; Fang, Xiao
2018-07-01
The anisotropy of galaxy clustering in redshift space has long been used to probe the rate of growth of cosmological perturbations. However, if galaxies are aligned by large-scale tidal fields, then a sample with an orientation-dependent selection effect has an additional anisotropy imprinted on to its correlation function. We use the LOWZ and CMASS catalogues of SDSS-III BOSS Data Release 12 to divide galaxies into two subsamples based on their offset from the Fundamental Plane, which should be correlated with orientation. These subsamples must trace the same underlying cosmology, but have opposite orientation-dependent selection effects. We measure the clustering parameters of each subsample and compare them in order to calculate the dimensionless parameter B, a measure of how strongly galaxies are aligned by gravitational tidal fields. We found that for CMASS (LOWZ), the measured B was -0.024 ± 0.015 (-0.030 ± 0.016). This result can be compared to the theoretical predictions of Hirata, who argued that since galaxy formation physics does not depend on the direction of the `observer,' the same intrinsic alignment parameters that describe galaxy-ellipticity correlations should also describe intrinsic alignments in the radial direction. We find that the ratio of observed to theoretical values is 0.51 ± 0.32 (0.77 ± 0.41) for CMASS (LOWZ). We combine the results to obtain a total Obs/Theory = 0.61 ± 0.26. This measurement constitutes evidence (between 2σand 3σ) for radial intrinsic alignments, and is consistent with theoretical expectations (<2σ difference).
A Radial Measurement of the Galaxy Tidal Alignment Magnitude with BOSS Data
NASA Astrophysics Data System (ADS)
Martens, Daniel; Hirata, Christopher M.; Ross, Ashley J.; Fang, Xiao
2018-05-01
The anisotropy of galaxy clustering in redshift space has long been used to probe the rate of growth of cosmological perturbations. However, if galaxies are aligned by large-scale tidal fields, then a sample with an orientation-dependent selection effect has an additional anisotropy imprinted onto its correlation function. We use the LOWZ and CMASS catalogs of SDSS-III BOSS Data Release 12 to divide galaxies into two sub-samples based on their offset from the Fundamental Plane, which should be correlated with orientation. These sub-samples must trace the same underlying cosmology, but have opposite orientation-dependent selection effects. We measure the clustering parameters of each sub-sample and compare them in order to calculate the dimensionless parameter B, a measure of how strongly galaxies are aligned by gravitational tidal fields. We found that for CMASS (LOWZ), the measured B was -0.024 ± 0.015 (-0.030 ± 0.016). This result can be compared to the theoretical predictions of Hirata (2009), who argued that since galaxy formation physics does not depend on the direction of the "observer," the same intrinsic alignment parameters that describe galaxy-ellipticity correlations should also describe intrinsic alignments in the radial direction. We find that the ratio of observed to theoretical values is 0.51 ± 0.32 (0.77 ± 0.41) for CMASS (LOWZ). We combine the results to obtain a total Obs/Theory = 0.61 ± 0.26. This measurement constitutes evidence (between 2 and 3σ) for radial intrinsic alignments, and is consistent with theoretical expectations (<2σ difference).
Freezing-thawing and sub-sampling influence the marination performance of chicken breast meat.
Bowker, B; Zhuang, H
2017-09-01
Vacuum-tumbling marination is often used to improve the yield and quality of whole or portioned broiler breast fillets. The relationship between the marination performance of whole Pectoralis major muscles and breast fillet sub-samples is not well understood. The objective was to determine the effects of sub-sampling and freezing-thawing on the marination performance and cook loss of broiler breast meat. Paired right and left breast fillets were marinated as whole fillets or sub-samples (cranial and mid-caudal portions). Samples were marinated at 48 h postmortem (fresh) or stored at -20°C and then thawed prior to marination (frozen-thawed). Samples were vacuum-tumbled in 20% wt/wt brine (5% NaCl, 3% STP) and weighed pre-marination, during marination (15, 30, and 45 min), and 24 h post-marination. Samples were then cooked to 75°C for determination of cook loss. Marinade uptake was greater in caudal sub-samples than intact fillets and cranial sub-samples after 15 min of marination (P < 0.0001). After 30 min, marinade uptake was greater in caudal sub-samples and intact fillets than cranial sub-samples (P < 0.05). After 45 min, marinade uptake for fresh samples was greatest in intact fillets and lowest in cranial sub-samples. For frozen-thawed samples, marinade uptake at 45 min was greater in caudal sub-samples and intact fillets than cranial sub-samples (P < 0.0001). Marinade uptake in sub-samples at 30 min was greater in frozen-thawed versus fresh fillets (P < 0.05). Differences in marinade retention were not observed. Cook loss was similar between fresh and frozen-thawed samples but was greater in sub-samples compared to intact fillets (P < 0.0001). Correlations between marinade uptake in intact fillets and cranial sub-samples were greater in fresh (r = 0.64 to 0.78) than frozen-thawed samples (r = 0.39 to 0.59). Correlations between marinade uptake in intact fillets and caudal sub-samples were greater in frozen-thawed (r = 0.79 to 0.82) than fresh samples (r = 0.46 to 0.63). Data suggest that the relationships between marination performance of whole breast fillets and fillet sub-samples are dependent upon prior sample handling and intra-fillet sampling location. Published by Oxford University Press on behalf of Poultry Science Association 2017.
Errors of five-day mean surface wind and temperature conditions due to inadequate sampling
NASA Technical Reports Server (NTRS)
Legler, David M.
1991-01-01
Surface meteorological reports of wind components, wind speed, air temperature, and sea-surface temperature from buoys located in equatorial and midlatitude regions are used in a simulation of random sampling to determine errors of the calculated means due to inadequate sampling. Subsampling the data with several different sample sizes leads to estimates of the accuracy of the subsampled means. The number N of random observations needed to compute mean winds with chosen accuracies of 0.5 (N sub 0.5) and 1.0 (N sub 1,0) m/s and mean air and sea surface temperatures with chosen accuracies of 0.1 (N sub 0.1) and 0.2 (N sub 0.2) C were calculated for each 5-day and 30-day period in the buoy datasets. Mean values of N for the various accuracies and datasets are given. A second-order polynomial relation is established between N and the variability of the data record. This relationship demonstrates that for the same accuracy, N increases as the variability of the data record increases. The relationship is also independent of the data source. Volunteer-observing ship data do not satisfy the recommended minimum number of observations for obtaining 0.5 m/s and 0.2 C accuracy for most locations. The effect of having remotely sensed data is discussed.
ERIC Educational Resources Information Center
Freed, Allison
2018-01-01
Environmental education scholars have argued for the need to focus on identity as a more predictive factor than attitude of individuals' environmental behavior. We examine individuals' decision-making as a mediating process between identity and behavior. University undergraduates (N = 299) were surveyed, with a select sub-sample interviewed. As…
ADHD Symptoms in Children with Mild Intellectual Disability
ERIC Educational Resources Information Center
Simonoff, Emily; Pickles, Andrew; Wood, Nicky; Gringras, Paul; Chadwick, Oliver
2007-01-01
Objectives: To determine whether the nature and correlates of attention-deficit/hyperactivity disorder (ADHD) symptoms are different in subjects with mild intellectual disability (ID) compared to subjects with average ability. Method: From a general population sample of 2,726 12- to 15-year-olds, a stratified subsample was selected to enrich for…
Denissen, Jaap J A; Ulferts, Hannah; Lüdtke, Oliver; Muck, Peter M; Gerstorf, Denis
2014-07-01
Social norms are central to theoretical accounts of longitudinal person-environment transactions. On the one hand, individuals are thought to select themselves into social roles that fit their personality. On the other hand, it is assumed that individuals' personality is transformed by the socializing pressure of norm demands. These 2 transactional directions were investigated in a large and heterogeneous 5-year longitudinal subsample of job beginners (n = 640, M age = 21.24), job stayers (n = 4,137, M age = 46.63), and job changers (n = 2,854, M age = 44.68) from the German Socio-Economic Panel. Role demands were coded by both students and labor market experts. To demonstrate transactional effects, cross-lagged structural equation models were estimated. Substantial selection effects were found for both job beginners and job changers. There was also evidence for socialization effects, especially for participants who did not change jobs. Depending on the trait and the subsample that was investigated, selection effects were sometimes corresponsive with socialization effects. Personality role demands were temporally consistent across a 4-year period even when individuals changed jobs (heterotypic continuity). This is one of the first empirical demonstrations of the transactional processes that lead to the formation of social niches. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
Nyström type subsampling analyzed as a regularized projection
NASA Astrophysics Data System (ADS)
Kriukova, Galyna; Pereverzyev, Sergiy, Jr.; Tkachenko, Pavlo
2017-07-01
In the statistical learning theory the Nyström type subsampling methods are considered as tools for dealing with big data. In this paper we consider Nyström subsampling as a special form of the projected Lavrentiev regularization, and study it using the approaches developed in the regularization theory. As a result, we prove that the same capacity independent learning rates that are guaranteed for standard algorithms running with quadratic computational complexity can be obtained with subquadratic complexity by the Nyström subsampling approach, provided that the subsampling size is chosen properly. We propose a priori rule for choosing the subsampling size and a posteriori strategy for dealing with uncertainty in the choice of it. The theoretical results are illustrated by numerical experiments.
Bellier, Edwige; Grøtan, Vidar; Engen, Steinar; Schartau, Ann Kristin; Diserud, Ola H; Finstad, Anders G
2012-10-01
Obtaining accurate estimates of diversity indices is difficult because the number of species encountered in a sample increases with sampling intensity. We introduce a novel method that requires that the presence of species in a sample to be assessed while the counts of the number of individuals per species are only required for just a small part of the sample. To account for species included as incidence data in the species abundance distribution, we modify the likelihood function of the classical Poisson log-normal distribution. Using simulated community assemblages, we contrast diversity estimates based on a community sample, a subsample randomly extracted from the community sample, and a mixture sample where incidence data are added to a subsample. We show that the mixture sampling approach provides more accurate estimates than the subsample and at little extra cost. Diversity indices estimated from a freshwater zooplankton community sampled using the mixture approach show the same pattern of results as the simulation study. Our method efficiently increases the accuracy of diversity estimates and comprehension of the left tail of the species abundance distribution. We show how to choose the scale of sample size needed for a compromise between information gained, accuracy of the estimates and cost expended when assessing biological diversity. The sample size estimates are obtained from key community characteristics, such as the expected number of species in the community, the expected number of individuals in a sample and the evenness of the community.
Optimal sampling with prior information of the image geometry in microfluidic MRI.
Han, S H; Cho, H; Paulsen, J L
2015-03-01
Recent advances in MRI acquisition for microscopic flows enable unprecedented sensitivity and speed in a portable NMR/MRI microfluidic analysis platform. However, the application of MRI to microfluidics usually suffers from prolonged acquisition times owing to the combination of the required high resolution and wide field of view necessary to resolve details within microfluidic channels. When prior knowledge of the image geometry is available as a binarized image, such as for microfluidic MRI, it is possible to reduce sampling requirements by incorporating this information into the reconstruction algorithm. The current approach to the design of the partial weighted random sampling schemes is to bias toward the high signal energy portions of the binarized image geometry after Fourier transformation (i.e. in its k-space representation). Although this sampling prescription is frequently effective, it can be far from optimal in certain limiting cases, such as for a 1D channel, or more generally yield inefficient sampling schemes at low degrees of sub-sampling. This work explores the tradeoff between signal acquisition and incoherent sampling on image reconstruction quality given prior knowledge of the image geometry for weighted random sampling schemes, finding that optimal distribution is not robustly determined by maximizing the acquired signal but from interpreting its marginal change with respect to the sub-sampling rate. We develop a corresponding sampling design methodology that deterministically yields a near optimal sampling distribution for image reconstructions incorporating knowledge of the image geometry. The technique robustly identifies optimal weighted random sampling schemes and provides improved reconstruction fidelity for multiple 1D and 2D images, when compared to prior techniques for sampling optimization given knowledge of the image geometry. Copyright © 2015 Elsevier Inc. All rights reserved.
King-Shier, Kathryn M; Hemmelgarn, Brenda R; Musto, Richard; Quan, Hude
2014-01-01
Background: Francophones who live outside the primarily French-speaking province of Quebec, Canada, risk being excluded from research by lack of a sampling frame. We examined the adequacy of random sampling, advertising, and respondent-driven sampling for recruitment of francophones for survey research. Methods: We recruited francophones residing in the city of Calgary, Alberta, through advertising and respondentdriven sampling. These 2 samples were then compared with a random subsample of Calgary francophones derived from the 2006 Canadian Community Health Survey (CCHS). We assessed the effectiveness of advertising and respondent-driven sampling in relation to the CCHS sample by comparing demographic characteristics and selected items from the CCHS (specifically self-reported general health status, perceived weight, and having a family doctor). Results: We recruited 120 francophones through advertising and 145 through respondent-driven sampling; the random sample from the CCHS consisted of 259 records. The samples derived from advertising and respondentdriven sampling differed from the CCHS in terms of age (mean ages 41.0, 37.6, and 42.5 years, respectively), sex (proportion of males 26.1%, 40.6%, and 56.6%, respectively), education (college or higher 86.7% , 77.9% , and 59.1%, respectively), place of birth (immigrants accounting for 45.8%, 55.2%, and 3.7%, respectively), and not having a regular medical doctor (16.7%, 34.5%, and 16.6%, respectively). Differences were not tested statistically because of limitations on the analysis of CCHS data imposed by Statistics Canada. Interpretation: The samples generated exclusively through advertising and respondent-driven sampling were not representative of the gold standard sample from the CCHS. Use of such biased samples for research studies could generate misleading results. PMID:25426180
Kjartansdottir, Ingibjorg; Arngrimsson, Sigurbjorn A; Bjarnason, Ragnar; Olafsdottir, Anna S
2018-06-01
This study investigated the associations, by sex, between sleep and adiposity, dietary habits, cardiorespiratory fitness and metabolic risk in 18-year-old students. We carried out a cross-sectional study of 199 randomly chosen, healthy 18-year-old students (53% girls) in Iceland's capital region. The data collection took place in the winter months of 2012 to 2015. The anthropometric measurements were body mass index, waist circumference and body fat percentage. Sleep duration and dietary habits were self-reported. Cardiorespiratory fitness was measured on a stationary bicycle. A subsample of 152 participants gave blood samples. A quarter of the adolescents failed to reach the minimum recommended sleep duration of seven hours per night on weekdays. In girls, the average sleep score was associated with body mass index and waist circumference, after adjusting for cardiorespiratory fitness and unhealthy eating scores. In boys, the average sleep score was not associated with anthropometric measurements, but cardiorespiratory fitness was an independent predictor (p < 0.001). No associations were found between average sleep scores and metabolic profiles in either sex. Sleep duration and adiposity only appeared to be associated in girls and were independent of cardiorespiratory fitness and unhealthy eating. Sleep duration was not related to metabolic risk. ©2018 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.
Women's Perceptions of Reproductive Health in Three Communities around Beirut, Lebanon
Kaddour, Afamia; Hafez, Raghda; Zurayk, Huda
2006-01-01
The aim of this study was to elicit definitions of the concept of reproductive health among women in three communities around Beirut, Lebanon, as part of the reproductive health component of a larger Urban Health Study. The communities were characterised by poverty, rural-urban mobility and heterogeneous refugee and migrant populations. A random sample of 1,869 women of reproductive age completed a questionnaire, of whom a sub-sample of 201 women were randomly selected. The women's understanding of good reproductive health included three major themes, which were expressed differently in the three communities. Their understanding included good physical and mental health, and underscored the need for activities promoting health. Their ability to reproduce and raise children, practise family planning and birth spacing, and go through pregnancy and motherhood safely were central to their reproductive duties and their social status. Finally, they saw reproductive health within the context of economic status, good marital relations and strength to cope with their lives. These findings point to the need to situate interventions in the life course of women, their health and that of their husbands and families; the importance of reproduction not only from a health services point of view, but also as regards women's roles and responsibilities within marriage and their families; and taking account of the harsh socio-economic conditions in their communities. A 2005 Reproductive Health Matters. All rights reserved. PMID:16035595
Women's perceptions of reproductive health in three communities around Beirut, Lebanon.
Kaddour, Afamia; Hafez, Raghda; Zurayk, Huda
2005-05-01
The aim of this study was to elicit definitions of the concept of reproductive health among women in three communities around Beirut, Lebanon, as part of the reproductive health component of a larger Urban Health Study. The communities were characterised by poverty, rural-urban mobility and heterogeneous refugee and migrant populations. A random sample of 1,869 women of reproductive age completed a questionnaire, of whom a sub-sample of 201 women were randomly selected. The women's understanding of good reproductive health included three major themes, which were expressed differently in the three communities. Their understanding included good physical and mental health, and underscored the need for activities promoting health. Their ability to reproduce and raise children, practise family planning and birth spacing, and go through pregnancy and motherhood safely were central to their reproductive duties and their social status. Finally, they saw reproductive health within the context of economic status, good marital relations and strength to cope with their lives. These findings point to the need to situate interventions in the life course of women, their health and that of their husbands and families; the importance of reproduction not only from a health services point of view, but also as regards women's roles and responsibilities within marriage and their families; and taking account of the harsh socio-economic conditions in their communities.
Algorithmic Contexts and Learning Potentiality: A Case Study of Students' Understanding of Calculus
ERIC Educational Resources Information Center
Pettersson, Kerstin; Scheja, Max
2008-01-01
The study explores the nature of students' conceptual understanding of calculus. Twenty students of engineering were asked to reflect in writing on the meaning of the concepts of limit and integral. A sub-sample of four students was selected for subsequent interviews, which explored in detail the students' understandings of the two concepts.…
ERIC Educational Resources Information Center
Piche, Genevieve; Bergeron, Lise; Cyr, Mireille; Berthiaume, Claude
2011-01-01
We investigated the interaction effects between mother's lifetime depressive/anxiety disorders and psychosocial correlates of 6 to 11 year-old children's self-reported externalizing symptoms in the Quebec Child Mental Health Survey. A representative subsample of 1,490 Quebec children aged 6 to 11 years was selected from the original sample. We…
Adolescent exposure to extremely violent movies.
Sargent, James D; Heatherton, Todd F; Ahrens, M Bridget; Dalton, Madeline A; Tickle, Jennifer J; Beach, Michael L
2002-12-01
To determine exposure of young adolescents to extremely violent movies. Cross-sectional school-based survey of middle school students at 15 randomly selected New Hampshire and Vermont middle schools. Each survey contained a unique list of 50 movies, randomly selected from 603 top box office hits from 1988 to 1999, 51 of which were determined by content analysis to contain extremely violent material. Movie titles only were listed, and adolescents were asked to indicate which ones they had seen. Each movie appeared on approximately 470 surveys. We calculated the percentage of students who had seen each movie for a representative subsample of the student population. We also examined characteristics associated with seeing at least one extremely violent movie. Complete survey information was obtained from 5,456 students. The sample was primarily white and equally distributed by gender. On average, extremely violent movies were seen by 28% of the students in the sample (range 4% to 66%). The most popular movie, Scream, was seen by two-thirds of students overall and over 40% of fifth-graders. Other movies with sexualized violent content were seen by many of these adolescents. Examples include The General's Daughter (rated R for "graphic images related to sexual violence including a rape scene and perverse sexuality") and Natural Born Killers (rated R for "extreme violence and graphic carnage, shocking images, language, and sexuality"), seen by 27% and 20%, respectively. Older students, males, those of lower socioeconomic status, and those with poorer school performance were all significantly more likely to have seen at least one extremely violent movie. This study documents widespread exposure of young adolescents to movies with brutal, and often sexualized, violence. Given that many of these films were marketed to teens, better oversight of the marketing practices of the film industry may be warranted.
Estimation of reference intervals from small samples: an example using canine plasma creatinine.
Geffré, A; Braun, J P; Trumel, C; Concordet, D
2009-12-01
According to international recommendations, reference intervals should be determined from at least 120 reference individuals, which often are impossible to achieve in veterinary clinical pathology, especially for wild animals. When only a small number of reference subjects is available, the possible bias cannot be known and the normality of the distribution cannot be evaluated. A comparison of reference intervals estimated by different methods could be helpful. The purpose of this study was to compare reference limits determined from a large set of canine plasma creatinine reference values, and large subsets of this data, with estimates obtained from small samples selected randomly. Twenty sets each of 120 and 27 samples were randomly selected from a set of 1439 plasma creatinine results obtained from healthy dogs in another study. Reference intervals for the whole sample and for the large samples were determined by a nonparametric method. The estimated reference limits for the small samples were minimum and maximum, mean +/- 2 SD of native and Box-Cox-transformed values, 2.5th and 97.5th percentiles by a robust method on native and Box-Cox-transformed values, and estimates from diagrams of cumulative distribution functions. The whole sample had a heavily skewed distribution, which approached Gaussian after Box-Cox transformation. The reference limits estimated from small samples were highly variable. The closest estimates to the 1439-result reference interval for 27-result subsamples were obtained by both parametric and robust methods after Box-Cox transformation but were grossly erroneous in some cases. For small samples, it is recommended that all values be reported graphically in a dot plot or histogram and that estimates of the reference limits be compared using different methods.
Inadequacy of internal covariance estimation for super-sample covariance
NASA Astrophysics Data System (ADS)
Lacasa, Fabien; Kunz, Martin
2017-08-01
We give an analytical interpretation of how subsample-based internal covariance estimators lead to biased estimates of the covariance, due to underestimating the super-sample covariance (SSC). This includes the jackknife and bootstrap methods as estimators for the full survey area, and subsampling as an estimator of the covariance of subsamples. The limitations of the jackknife covariance have been previously presented in the literature because it is effectively a rescaling of the covariance of the subsample area. However we point out that subsampling is also biased, but for a different reason: the subsamples are not independent, and the corresponding lack of power results in SSC underprediction. We develop the formalism in the case of cluster counts that allows the bias of each covariance estimator to be exactly predicted. We find significant effects for a small-scale area or when a low number of subsamples is used, with auto-redshift biases ranging from 0.4% to 15% for subsampling and from 5% to 75% for jackknife covariance estimates. The cross-redshift covariance is even more affected; biases range from 8% to 25% for subsampling and from 50% to 90% for jackknife. Owing to the redshift evolution of the probe, the covariances cannot be debiased by a simple rescaling factor, and an exact debiasing has the same requirements as the full SSC prediction. These results thus disfavour the use of internal covariance estimators on data itself or a single simulation, leaving analytical prediction and simulations suites as possible SSC predictors.
Moore, Simon C; Alam, M Fasihul; Heikkinen, Marjukka; Hood, Kerenza; Huang, Chao; Moore, Laurence; Murphy, Simon; Playle, Rebecca; Shepherd, Jonathan; Shovelton, Claire; Sivarajasingam, Vaseekaran; Williams, Anne
2017-11-01
Premises licensed for the sale and consumption of alcohol can contribute to levels of assault-related injury through poor operational practices that, if addressed, could reduce violence. We tested the real-world effectiveness of an intervention designed to change premises operation, whether any intervention effect changed over time, and the effect of intervention dose. A parallel randomized controlled trial with the unit of allocation and outcomes measured at the level of individual premises. All premises (public houses, nightclubs or hotels with a public bar) in Wales, UK. A randomly selected subsample (n = 600) of eligible premises (that had one or more violent incidents recorded in police-recorded crime data; n = 837) were randomized into control and intervention groups. Intervention premises were audited by Environmental Health Practitioners who identified risks for violence and provided feedback by varying dose (informal, through written advice, follow-up visits) on how risks could be addressed. Control premises received usual practice. Police data were used to derive a binary variable describing whether, on each day premises were open, one or more violent incidents were evident over a 455-day period following randomization. Due to premises being unavailable at the time of intervention delivery 208 received the intervention and 245 were subject to usual practice in an intention-to-treat analysis. The intervention was associated with an increase in police recorded violence compared to normal practice (hazard ratio = 1.34, 95% confidence interval = 1.20-1.51). Exploratory analyses suggested that reduced violence was associated with greater intervention dose (follow-up visits). An Environmental Health Practitioner-led intervention in premises licensed for the sale and on-site consumption of alcohol resulted in an increase in police recorded violence. © 2017 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.
Alam, M. Fasihul; Heikkinen, Marjukka; Hood, Kerenza; Huang, Chao; Moore, Laurence; Murphy, Simon; Playle, Rebecca; Shepherd, Jonathan; Shovelton, Claire; Sivarajasingam, Vaseekaran; Williams, Anne
2017-01-01
Abstract Background and Aims Premises licensed for the sale and consumption of alcohol can contribute to levels of assault‐related injury through poor operational practices that, if addressed, could reduce violence. We tested the real‐world effectiveness of an intervention designed to change premises operation, whether any intervention effect changed over time, and the effect of intervention dose. Design A parallel randomized controlled trial with the unit of allocation and outcomes measured at the level of individual premises. Setting All premises (public houses, nightclubs or hotels with a public bar) in Wales, UK. Participants A randomly selected subsample (n = 600) of eligible premises (that had one or more violent incidents recorded in police‐recorded crime data; n = 837) were randomized into control and intervention groups. Intervention and comparator Intervention premises were audited by Environmental Health Practitioners who identified risks for violence and provided feedback by varying dose (informal, through written advice, follow‐up visits) on how risks could be addressed. Control premises received usual practice. Measurements Police data were used to derive a binary variable describing whether, on each day premises were open, one or more violent incidents were evident over a 455‐day period following randomization. Findings Due to premises being unavailable at the time of intervention delivery 208 received the intervention and 245 were subject to usual practice in an intention‐to‐treat analysis. The intervention was associated with an increase in police recorded violence compared to normal practice (hazard ratio = 1.34, 95% confidence interval = 1.20–1.51). Exploratory analyses suggested that reduced violence was associated with greater intervention dose (follow‐up visits). Conclusion An Environmental Health Practitioner‐led intervention in premises licensed for the sale and on‐site consumption of alcohol resulted in an increase in police recorded violence. PMID:28543914
Sexing adult black-legged kittiwakes by DNA, behavior, and morphology
Jodice, P.G.R.; Lanctot, Richard B.; Gill, V.A.; Roby, D.D.; Hatch, Shyla A.
2000-01-01
We sexed adult Black-legged Kittiwakes (Rissa tridactyla) using DNA-based genetic techniques, behavior and morphology and compared results from these techniques. Genetic and morphology data were collected on 605 breeding kittiwakes and sex-specific behaviors were recorded for a sub-sample of 285 of these individuals. We compared sex classification based on both genetic and behavioral techniques for this sub-sample to assess the accuracy of the genetic technique. DNA-based techniques correctly sexed 97.2% and sex-specific behaviors, 96.5% of this sub-sample. We used the corrected genetic classifications from this sub-sample and the genetic classifications for the remaining birds, under the assumption they were correct, to develop predictive morphometric discriminant function models for all 605 birds. These models accurately predicted the sex of 73-96% of individuals examined, depending on the sample of birds used and the characters included. The most accurate single measurement for determining sex was length of head plus bill, which correctly classified 88% of individuals tested. When both members of a pair were measured, classification levels improved and approached the accuracy of both behavioral observations and genetic analyses. Morphometric techniques were only slightly less accurate than genetic techniques but were easier to implement in the field and less costly. Behavioral observations, while highly accurate, required that birds be easily observable during the breeding season and that birds be identifiable. As such, sex-specific behaviors may best be applied as a confirmation of sex for previously marked birds. All three techniques thus have the potential to be highly accurate, and the selection of one or more will depend on the circumstances of any particular field study.
Moulton, Stephen R.; Carter, James L.; Grotheer, Scott A.; Cuffney, Thomas F.; Short, Terry M.
2000-01-01
Qualitative and quantitative methods to process benthic macroinvertebrate (BMI) samples have been developed and tested by the U.S. Geological Survey?s National Water Quality Laboratory Biological Group. The qualitative processing method is based on visually sorting a sample for up to 2 hours. Sorting focuses on attaining organisms that are likely to result in taxonomic identifications to lower taxonomic levels (for example, Genus or Species). Immature and damaged organisms are also sorted when they are likely to result in unique determinations. The sorted sample remnant is scanned briefly by a second person to determine if obvious taxa were missed. The quantitative processing method is based on a fixed-count approach that targets some minimum count, such as 100 or 300 organisms. Organisms are sorted from randomly selected 5.1- by 5.1-centimeter parts of a gridded subsampling frame. The sorted remnant from each sample is resorted by a second individual for at least 10 percent of the original sort time. A large-rare organism search is performed on the unsorted remnant to sort BMI taxa that were not likely represented in the sorted grids. After either qualitatively or quantitatively sorting the sample, BMIs are identified by using one of three different types of taxonomic assessment. The Standard Taxonomic Assessment is comparable to the U.S. Environmental Protection Agency Rapid Bioassessment Protocol III and typically provides Genus- or Species-level taxonomic resolution. The Rapid Taxonomic Assessment is comparable to the U.S. Environmental Protection Agency Rapid Bioassessment Protocol II and provides Familylevel and higher taxonomic resolution. The Custom Taxonomic Assessment provides Species-level resolution whenever possible for groups identified to higher taxonomic levels by using the Standard Taxonomic Assessment. The consistent use of standardized designations and notes facilitates the interpretation of BMI data within and among water-quality studies. Taxonomic identifications are quality assured by verifying all referenced taxa and randomly reviewing 10 percent of the taxonomic identifications performed weekly by Biological Group taxonomists. Taxonomic errors discovered during this review are corrected. BMI data are reviewed for accuracy and completeness prior to release. BMI data are released phylogenetically in spreadsheet format and unprocessed abundances are corrected for laboratory and field subsampling when necessary.
Analysis and comparison of nonlinear tree height prediction strategies for Douglas-fir forest.
H. Temesgen; V.J. Monleon; D.W. Hann
2008-01-01
Using an extensive Douglas-fir data set from southwest Oregon, we examined the (I) performance and suitability of selected prediction strategies, (2) contribution of relative position and stand-density measures in improving tree height (h) prediction values, and (3) effect of different subsampling designs to fill in missing h values in a new stand using a regional...
ERIC Educational Resources Information Center
Mbajiorgu, Ngozika; Anidu, Innocent
2017-01-01
Senior secondary school students (N = 360), 14- to 18-year-olds, from the Igbo culture of eastern Nigeria responded to a questionnaire requiring them to give causal explanations of biologically adaptive changes in humans, other animals and plants. A student subsample (n = 36) was, subsequently, selected for in-depth interviews. Significant…
High School and Beyond First Follow-Up (1982). Sample Design Report.
ERIC Educational Resources Information Center
Tourangeau, Roger; And Others
This report documents the major technical aspects of the sample selection and implementation of the 1982 High School and Beyond First Follow Up, the first in a series of planned resurveys of the students and schools in the 1980 High School and Beyond Base Year Survey. The First Follow-Up included subsamples of nearly 30,000 sophomore cohort and…
Li, Dan; Hu, Nan; Yu, Yueyi; Zhou, Aihong; Li, Fangyu; Jia, Jianping
2017-01-01
Despite its popularity, the latent structure of 22-item Zarit Burden Interview (ZBI) remains unclear. There has been no study exploring how caregiver multidimensional burden changed. The aim of the work was to validate the latent structure of ZBI and to investigate how multidimensional burden evolves with increasing global burden. We studied 1,132 dyads of dementia patients and their informal caregivers. The caregivers completed the ZBI and a questionnaire regarding caregiving. The total sample was randomly split into two equal subsamples. Exploratory factor analysis (EFA) was performed in the first subsample. In the second subsample, confirmatory factor analysis (CFA) was conducted to validate models generated from EFA. The mean of weighted factor score was calculated to assess the change of dimension burden against the increasing ZBI total score. The result of EFA and CFA supported that a five-factor structure, including role strain, personal strain, incompetency, dependency, and guilt, had the best goodness-of-fit. The trajectories of multidimensional burden suggested that three different dimensions (guilt, role strain and personal strain) became the main subtype of burden in sequence as the ZBI total score increased from mild to moderate. Factor dependency contributed prominently to the total burden in severe stage. The five-factor ZBI is a psychometrically robust measure for assessing multidimensional burden in Chinese caregivers. The changes of multidimensional burden have deepened our understanding of the psychological characteristics of caregiving beyond a single total score and may be useful for developing interventions to reduce caregiver burden.
Characterizing user engagement with health app data: a data mining approach.
Serrano, Katrina J; Coa, Kisha I; Yu, Mandi; Wolff-Hughes, Dana L; Atienza, Audie A
2017-06-01
The use of mobile health applications (apps) especially in the area of lifestyle behaviors has increased, thus providing unprecedented opportunities to develop health programs that can engage people in real-time and in the real-world. Yet, relatively little is known about which factors relate to the engagement of commercially available apps for health behaviors. This exploratory study examined behavioral engagement with a weight loss app, Lose It! and characterized higher versus lower engaged groups. Cross-sectional, anonymized data from Lose It! were analyzed (n = 12,427,196). This dataset was randomly split into 24 subsamples and three were used for this study (total n = 1,011,008). Classification and regression tree methods were used to identify subgroups of user engagement with one subsample, and descriptive analyses were conducted to examine other group characteristics associated with engagement. Data mining validation methods were conducted with two separate subsamples. On average, users engaged with the app for 29 days. Six unique subgroups were identified, and engagement for each subgroup varied, ranging from 3.5 to 172 days. Highly engaged subgroups were primarily distinguished by the customization of diet and exercise. Those less engaged were distinguished by weigh-ins and the customization of diet. Results were replicated in further analyses. Commercially-developed apps can reach large segments of the population, and data from these apps can provide insights into important app features that may aid in user engagement. Getting users to engage with a mobile health app is critical to the success of apps and interventions that are focused on health behavior change.
Peng, Bo; Wang, Yuqi; Hall, Timothy J; Jiang, Jingfeng
2017-04-01
Our primary objective of this paper was to extend a previously published 2-D coupled subsample tracking algorithm for 3-D speckle tracking in the framework of ultrasound breast strain elastography. In order to overcome heavy computational cost, we investigated the use of a graphic processing unit (GPU) to accelerate the 3-D coupled subsample speckle tracking method. The performance of the proposed GPU implementation was tested using a tissue-mimicking phantom and in vivo breast ultrasound data. The performance of this 3-D subsample tracking algorithm was compared with the conventional 3-D quadratic subsample estimation algorithm. On the basis of these evaluations, we concluded that the GPU implementation of this 3-D subsample estimation algorithm can provide high-quality strain data (i.e., high correlation between the predeformation and the motion-compensated postdeformation radio frequency echo data and high contrast-to-noise ratio strain images), as compared with the conventional 3-D quadratic subsample algorithm. Using the GPU implementation of the 3-D speckle tracking algorithm, volumetric strain data can be achieved relatively fast (approximately 20 s per volume [2.5 cm ×2.5 cm ×2.5 cm]).
AGES: THE AGN AND GALAXY EVOLUTION SURVEY
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kochanek, C. S.; Eisenstein, D. J.; Caldwell, N.
2012-05-01
The AGN and Galaxy Evolution Survey (AGES) is a redshift survey covering, in its standard fields, 7.7 deg{sup 2} of the Booetes field of the NOAO Deep Wide-Field Survey. The final sample consists of 23,745 redshifts. There are well-defined galaxy samples in 10 bands (the B{sub W} , R, I, J, K, IRAC 3.6, 4.5, 5.8, and 8.0 {mu}m, and MIPS 24 {mu}m bands) to a limiting magnitude of I < 20 mag for spectroscopy. For these galaxies, we obtained 18,163 redshifts from a sample of 35,200 galaxies, where random sparse sampling was used to define statistically complete sub-samples inmore » all 10 photometric bands. The median galaxy redshift is 0.31, and 90% of the redshifts are in the range 0.085 < z < 0.66. Active galactic nuclei (AGNs) were selected as radio, X-ray, IRAC mid-IR, and MIPS 24 {mu}m sources to fainter limiting magnitudes (I < 22.5 mag for point sources). Redshifts were obtained for 4764 quasars and galaxies with AGN signatures, with 2926, 1718, 605, 119, and 13 above redshifts of 0.5, 1, 2, 3, and 4, respectively. We detail all the AGES selection procedures and present the complete spectroscopic redshift catalogs and spectral energy distribution decompositions. Photometric redshift estimates are provided for all sources in the AGES samples.« less
Chung, Kuo-Liang; Huang, Chi-Chao; Hsu, Tsu-Chun
2017-09-04
In this paper, we propose a novel adaptive chroma subsampling-binding and luma-guided (ASBLG) chroma reconstruction method for screen content images (SCIs). After receiving the decoded luma and subsampled chroma image from the decoder, a fast winner-first voting strategy is proposed to identify the used chroma subsampling scheme prior to compression. Then, the decoded luma image is subsampled as the identified subsampling scheme was performed on the chroma image such that we are able to conclude an accurate correlation between the subsampled decoded luma image and the decoded subsampled chroma image. Accordingly, an adaptive sliding window-based and luma-guided chroma reconstruction method is proposed. The related computational complexity analysis is also provided. We take two quality metrics, the color peak signal-to-noise ratio (CPSNR) of the reconstructed chroma images and SCIs and the gradient-based structure similarity index (CGSS) of the reconstructed SCIs to evaluate the quality performance. Let the proposed chroma reconstruction method be denoted as 'ASBLG'. Based on 26 typical test SCIs and 6 JCT-VC test screen content video sequences (SCVs), several experiments show that on average, the CPSNR gains of all the reconstructed UV images by 4:2:0(A)-ASBLG, SCIs by 4:2:0(MPEG-B)-ASBLG, and SCVs by 4:2:0(A)-ASBLG are 2.1 dB, 1.87 dB, and 1.87 dB, respectively, when compared with that of the other combinations. Specifically, in terms of CPSNR and CGSS, CSBILINEAR-ASBLG for the test SCIs and CSBICUBIC-ASBLG for the test SCVs outperform the existing state-of-the-art comparative combinations, where CSBILINEAR and CSBICUBIC denote the luma-aware based chroma subsampling schemes by Wang et al.
Predictors of Suicide Ideation in a Random Digit Dial Study: Exposure to Suicide Matters.
van de Venne, Judy; Cerel, Julie; Moore, Melinda; Maple, Myfanwy
2017-07-03
Suicide is an important public health concern requiring ongoing research to understand risk factors for suicide ideation. A dual-frame, random digit dial survey was utilized to identify demographic and suicide-related factors associated with suicide ideation in a statewide sample of 1,736 adults. The PH-Q 9 Depression scale suicide ideation question was used to assess current suicide ideation in both the full sample and suicide exposed sub-sample. Being non-married and having previous suicide exposure were separately associated with higher risks of suicide ideation in the full sample. Being male, having increased suicide exposures, and having increased perceptions of closeness to the decedent increased risks, while older age decreased risks for the suicide exposed. Implications for future screening and research are discussed.
Akter, Tahera; Jhohura, Fatema Tuz; Akter, Fahmida; Chowdhury, Tridib Roy; Mistry, Sabuj Kanti; Dey, Digbijoy; Barua, Milan Kanti; Islam, Md Akramul; Rahman, Mahfuzar
2016-02-09
Public health is at risk due to chemical contaminants in drinking water which may have immediate health consequences. Drinking water sources are susceptible to pollutants depending on geological conditions and agricultural, industrial, and other man-made activities. Ensuring the safety of drinking water is, therefore, a growing problem. To assess drinking water quality, we measured multiple chemical parameters in drinking water samples from across Bangladesh with the aim of improving public health interventions. In this cross-sectional study conducted in 24 randomly selected upazilas, arsenic was measured in drinking water in the field using an arsenic testing kit and a sub-sample was validated in the laboratory. Water samples were collected to test water pH in the laboratory as well as a sub-sample of collected drinking water was tested for water pH using a portable pH meter. For laboratory testing of other chemical parameters, iron, manganese, and salinity, drinking water samples were collected from 12 out of 24 upazilas. Drinking water at sample sites was slightly alkaline (pH 7.4 ± 0.4) but within acceptable limits. Manganese concentrations varied from 0.1 to 5.5 mg/L with a median value of 0.2 mg/L. The median iron concentrations in water exceeded WHO standards (0.3 mg/L) at most of the sample sites and exceeded Bangladesh standards (1.0 mg/L) at a few sample sites. Salinity was relatively higher in coastal districts. After laboratory confirmation, arsenic concentrations were found higher in Shibchar (Madaripur) and Alfadanga (Faridpur) compared to other sample sites exceeding WHO standard (0.01 mg/L). Of the total sampling sites, 33 % had good-quality water for drinking based on the Water Quality Index (WQI). However, the majority of the households (67 %) used poor-quality drinking water. Higher values of iron, manganese, and arsenic reduced drinking water quality. Awareness raising on chemical contents in drinking water at household level is required to improve public health.
Steyn, K; Goldberg, Y P; Kotze, M J; Steyn, M; Swanepoel, A S; Fourie, J M; Coetzee, G A; Van der Westhuyzen, D R
1996-10-01
We have determined the prevalence of familial hypercholesterolaemia (FH) in a rural Afrikaner community by means of direct DNA screening for three founder-related Afrikaner low density lipoprotein (LDL) receptor gene mutations. A random sample of 1612 persons, aged 15-64 years, was selected as a subsample of 4583 subjects from an Afrikaner community living in the south-western Cape, South Africa. Participants who had a total serum cholesterol (TC) in the high TC category as defined in the consensus recommendations by the Southern African Heart Foundation, were screened for three founder-related LDL receptor gene mutations, causing FH in 90% of Afrikaners. Of the subsample, 201 participants (12.5%) had TC levels above the 80th percentile. In this group the combined prevalence of the three common Afrikaner LDL receptor gene defects (D206E, FH Afrikaner-1; V408M, FH Afrikaner-2; D154N, FH Afrikaner-3) was calculated as 1: 83. When taking into account the reported background prevalence of other FH gene defects of 1:500 in this community, their overall prevalence of FH was estimated to be 1:72. The significant differences found between the FH patients and other high risk patients with raised cholesterol levels were higher TC and LDL cholesterol levels and lower high density lipoprotein cholesterol levels in FH patients. The treatment status of the molecularly identified FH patients and other hypercholesterolaemic persons suggests that this condition is inadequately diagnosed and poorly managed in this study population. An extrapolation to the entire South African population suggests that there are about 112000 FH patients in the country who are under-diagnosed as a group and therefore not receiving the care that would help to reduce the burden of FH-associated ischaemic heart disease in South Africa.
Obstetric Outcomes of Mothers Previously Exposed to Sexual Violence.
Gisladottir, Agnes; Luque-Fernandez, Miguel Angel; Harlow, Bernard L; Gudmundsdottir, Berglind; Jonsdottir, Eyrun; Bjarnadottir, Ragnheidur I; Hauksdottir, Arna; Aspelund, Thor; Cnattingius, Sven; Valdimarsdottir, Unnur A
2016-01-01
There is a scarcity of data on the association of sexual violence and women's subsequent obstetric outcomes. Our aim was to investigate whether women exposed to sexual violence as teenagers (12-19 years of age) or adults present with different obstetric outcomes than women with no record of such violence. We linked detailed prospectively collected information on women attending a Rape Trauma Service (RTS) to the Icelandic Medical Birth Registry (IBR). Women who attended the RTS in 1993-2010 and delivered (on average 5.8 years later) at least one singleton infant in Iceland through 2012 formed our exposed cohort (n = 1068). For each exposed woman's delivery, nine deliveries by women with no RTS attendance were randomly selected from the IBR (n = 9126) matched on age, parity, and year and season of delivery. Information on smoking and Body mass index (BMI) was available for a sub-sample (n = 792 exposed and n = 1416 non-exposed women). Poisson regression models were used to estimate Relative Risks (RR) with 95% confidence intervals (CI). Compared with non-exposed women, exposed women presented with increased risks of maternal distress during labor and delivery (RR 1.68, 95% CI 1.01-2.79), prolonged first stage of labor (RR 1.40, 95% CI 1.03-1.88), antepartum bleeding (RR 1.95, 95% CI 1.22-3.07) and emergency instrumental delivery (RR 1.16, 95% CI 1.00-1.34). Slightly higher risks were seen for women assaulted as teenagers. Overall, we did not observe differences between the groups regarding the risk of elective cesarean section (RR 0.86, 95% CI 0.61-1.21), except for a reduced risk among those assaulted as teenagers (RR 0.56, 95% CI 0.34-0.93). Adjusting for maternal smoking and BMI in a sub-sample did not substantially affect point estimates. Our prospective data suggest that women with a history of sexual assault, particularly as teenagers, are at increased risks of some adverse obstetric outcomes.
Yang, Fan; Khin, Lay-Wai; Lau, Titus; Chua, Horng-Ruey; Vathsala, A; Lee, Evan; Luo, Nan
2015-01-01
Studies comparing patient survival of hemodialysis (HD) and peritoneal dialysis (PD) have yielded conflicting results and no such study was from South-East Asia. This study aimed to compare the survival outcomes of patients with end-stage renal disease (ESRD) who started dialysis with HD and PD in Singapore. Survival data for a maximum of 5 years from a single-center cohort of 871 ESRD patients starting dialysis with HD (n = 641) or PD (n = 230) from 2005-2010 was analyzed using the flexible Royston-Parmar (RP) model. The model was also applied to a subsample of 225 propensity-score-matched patient pairs and subgroups defined by age, diabetes mellitus, and cardiovascular disease. After adjusting for the effect of socio-demographic and clinical characteristics, the risk of death was higher in patients initiating dialysis with PD than those initiating dialysis with HD (hazard ratio [HR]: 2.08; 95% confidence interval [CI]: 1.67-2.59; p<0.001), although there was no significant difference in mortality between the two modalities in the first 12 months of treatment. Consistently, in the matched subsample, patients starting PD had a higher risk of death than those starting HD (HR: 1.73, 95% CI: 1.30-2.28, p<0.001). Subgroup analysis showed that PD may be similar to or better than HD in survival outcomes among young patients (≤65 years old) without diabetes or cardiovascular disease. ESRD patients who initiated dialysis with HD experienced better survival outcomes than those who initiated dialysis with PD in Singapore, although survival outcomes may not differ between the two dialysis modalities in young and healthier patients. These findings are potentially confounded by selection bias, as patients were not randomized to the two dialysis modalities in this cohort study.
Ngwakongnwi, Emmanuel; King-Shier, Kathryn M; Hemmelgarn, Brenda R; Musto, Richard; Quan, Hude
2014-01-01
Francophones who live outside the primarily French-speaking province of Quebec, Canada, risk being excluded from research by lack of a sampling frame. We examined the adequacy of random sampling, advertising, and respondent-driven sampling for recruitment of francophones for survey research. We recruited francophones residing in the city of Calgary, Alberta, through advertising and respondentdriven sampling. These 2 samples were then compared with a random subsample of Calgary francophones derived from the 2006 Canadian Community Health Survey (CCHS). We assessed the effectiveness of advertising and respondent-driven sampling in relation to the CCHS sample by comparing demographic characteristics and selected items from the CCHS (specifically self-reported general health status, perceived weight, and having a family doctor). We recruited 120 francophones through advertising and 145 through respondent-driven sampling; the random sample from the CCHS consisted of 259 records. The samples derived from advertising and respondentdriven sampling differed from the CCHS in terms of age (mean ages 41.0, 37.6, and 42.5 years, respectively), sex (proportion of males 26.1%, 40.6%, and 56.6%, respectively), education (college or higher 86.7% , 77.9% , and 59.1%, respectively), place of birth (immigrants accounting for 45.8%, 55.2%, and 3.7%, respectively), and not having a regular medical doctor (16.7%, 34.5%, and 16.6%, respectively). Differences were not tested statistically because of limitations on the analysis of CCHS data imposed by Statistics Canada. The samples generated exclusively through advertising and respondent-driven sampling were not representative of the gold standard sample from the CCHS. Use of such biased samples for research studies could generate misleading results.
Examining the cosmic acceleration with the latest Union2 supernova data
NASA Astrophysics Data System (ADS)
Li, Zhengxiang; Wu, Puxun; Yu, Hongwei
2011-01-01
In this Letter, by reconstructing the Om diagnostic and the deceleration parameter q from the latest Union2 Type Ia Supernova sample with and without the systematic error along with the baryon acoustic oscillation (BAO) and the cosmic microwave background (CMB), we study the cosmic expanding history, using the Chevallier-Polarski-Linder (CPL) parametrization. We obtain that Union2+BAO favor an expansion with a decreasing of the acceleration at z<0.3. However, once the CMB data is added in the analysis, the cosmic acceleration is found to be still increasing, indicating a tension between low redshift data and high redshift. In order to reduce this tension significantly, two different methods are considered and thus two different subsamples of Union2 are selected. We then find that two different subsamples+BAO+CMB give completely different results on the cosmic expanding history when the systematic error is ignored, with one suggesting a decreasing cosmic acceleration, the other just the opposite, although both of them alone with BAO support that the cosmic acceleration is slowing down. However, once the systematic error is considered, two different subsamples of Union2 along with BAO and CMB all favor an increasing of the present cosmic acceleration. Therefore a clear-cut answer on whether the cosmic acceleration is slowing down calls for more consistent data and more reliable methods to analyze them.
Bed-material characteristics of the Sacramento–San Joaquin Delta, California, 2010–13
Marineau, Mathieu D.; Wright, Scott A.
2017-02-10
The characteristics of bed material at selected sites within the Sacramento–San Joaquin Delta, California, during 2010–13 are described in a study conducted by the U.S. Geological Survey in cooperation with the Bureau of Reclamation. During 2010‒13, six complete sets of samples were collected. Samples were initially collected at 30 sites; however, starting in 2012, samples were collected at 7 additional sites. These sites are generally collocated with an active streamgage. At all but one site, a separate bed-material sample was collected at three locations within the channel (left, right, and center). Bed-material samples were collected using either a US BMH–60 or a US BM–54 (for sites with higher stream velocity) cable-suspended, scoop sampler. Samples from each location were oven-dried and sieved. Bed material finer than 2 millimeters was subsampled using a sieving riffler and processed using a Beckman Coulter LS 13–320 laser diffraction particle-size analyzer. To determine the organic content of the bed material, the loss on ignition method was used for one subsample from each location. Particle-size distributions are presented as cumulative percent finer than a given size. Median and 90th-percentile particle size, and the percentage of subsample mass lost using the loss on ignition method for each sample are also presented in this report.
McCloskey, Morgan L; Tarazona-Meza, Carla E; Jones-Smith, Jessica C; Miele, Catherine H; Gilman, Robert H; Bernabe-Ortiz, Antonio; Miranda, J Jaime; Checkley, William
2017-07-11
Diet and activity are thought to worsen with urbanization, thereby increasing risk of obesity and chronic diseases. A better understanding of dietary and activity patterns across the urbanization divide may help identify pathways, and therefore intervention targets, leading to the epidemic of overweight seen in low- and middle-income populations. Therefore, we sought to characterize diet and activity in a population-based study of urban and rural residents in Puno, Peru. We compared diet and activity in 1005 (503 urban, 502 rural) participants via a lifestyle questionnaire. We then recruited an age- and sex-stratified random sample of 50 (25 urban, 25 rural) participants to further characterize diet and activity. Among these participants, diet composition and macronutrient intake was assessed by three non-consecutive 24-h dietary recalls and physical activity was assessed using Omron JH-720itc pedometers. Among 1005 participants, we found that urban residents consumed protein-rich foods, refined grains, sugary items, and fresh produce more frequently than rural residents. Among the 50 subsample participants, urban dwellers consumed more protein (47 vs. 39 g; p = 0.05), more carbohydrates (280 vs. 220 g; p = 0.03), more sugary foods (98 vs. 48 g, p = 0.02) and had greater dietary diversity (6.4 vs 5.8; p = 0.04). Rural subsample participants consumed more added salt (3.1 vs 1.7 g, p = 0.006) and tended to consume more vegetable oil. As estimated by pedometers, urban subsample participants burned fewer calories per day (191 vs 270 kcal, p = 0.03). Although urbanization is typically thought to increase consumption of fat, sugar and salt, our 24-h recall results were mixed and showed lower levels of obesity in rural Puno were not necessarily indicative of nutritionally-balanced diets. All subsample participants had relatively traditional lifestyles (low fat intake, limited consumption of processed foods and frequent walking) that may play a role in chronic disease outcomes in this region.
Lemacks, Jennifer L.; Wickrama, Kandauda (K.A.S.); Young-Clark, Iris; Coccia, Catherine; Ilich, Jasminka Z.; Harris, Cynthia M.; Hart, Celeste B.; Battle, Arrie M.; O’Neal, Catherine Walker
2014-01-01
Introduction African Americans (AAs) experience higher age-adjusted morbidity and mortality than Whites for cardiovascular disease (CVD). Church-based health programs can reduce risk factors for CVD, including elevated blood pressure [BP], excess body weight, sedentary lifestyle and diet. Yet few studies have incorporated older adults and longitudinal designs. Purposes The aims of this study are to: a) describe a theory-driven longitudinal intervention study to reduce CVD risk in mid-life and older AAs; b) compare selected dietary (fruit and vegetable servings/day, fat consumption), physical activity (PA) and clinical variables (BMI, girth circumferences, systolic and diastolic BP, LDL, HDL, total cholesterol [CHOL] and HDL/CHOL) between treatment and comparison churches at baseline; c) identify selected background characteristics (life satisfaction, social support, age, gender, educational level, marital status, living arrangement and medication use) at baseline that may confound results; and d) share the lessons learned. Methods This study incorporated a longitudinal pre/post with comparison group quasi-experimental design. Community-based participatory research (CBPR) was used to discover ideas for the study, identify community advisors, recruit churches (three treatment, three comparison) in two-counties in North Florida, and randomly select 221 mid-life and older AAs (45+) (n = 104 in clinical subsample), stratifying for age and gender. Data were collected through self-report questionnaires and clinical assessments. Results and conclusions Dietary, PA and clinical results were similar to the literature. Treatment and comparison groups were similar in background characteristics and health behaviors but differed in selected clinical factors. For the total sample, relationships were noted for most of the background characteristics. Lessons learned focused on community relationships and participant recruitment. PMID:24685998
Astrøm, Anne Nordrehaug
2008-06-01
Using a prospective design and a representative sample of 25-yr-old Norwegians, this study hypothesized that action planning and coping planning will add to the prediction of flossing at 4 wk of follow-up over and above the effect of intention and previous flossing. This study tested the validity of a proposed 3-factor structure of the measurement model of intention, action planning, and coping planning and for its invariance across gender. A survey was conducted in three Norwegian counties, and 1,509 out of 8,000 randomly selected individuals completed questionnaires assessing the constructs of action planning and coping planning related to daily flossing. A random subsample of 500 participants was followed up at 4 wk with a telephone interview to assess flossing. Confirmatory factor analysis (CFA) confirmed the proposed 3-factor model after respecification. Although the chi-square test was statistically significant [chi(2) = 58.501, degrees of freedom (d.f.) = 17), complementary fit indices were satisfactory [goodness-of-fit index (GFI) = 0.99, root mean squared error of approximation (RMSEA) = 0.04]. Multigroup CFA provided evidence of complete invariance of the measurement model across gender. After controlling for previous flossing, intention (beta = 0.08) and action planning (beta = 0.11) emerged as independent predictors of subsequent flossing, accounting for 2.3% of its variance. Factorial validity of intention, action planning and coping planning, and the validity of action planning in predicting flossing prospectively, was confirmed by the present study.
40 CFR 761.350 - Subsampling from composite samples.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Subsampling from composite samples...-Site Disposal, in Accordance With § 761.61 § 761.350 Subsampling from composite samples. (a) Preparing the composite. Composite the samples (eight from a flattened pile; eight or more from a conical pile...
Peng, Bo; Wang, Yuqi; Hall, Timothy J; Jiang, Jingfeng
2017-01-01
Our primary objective of this work was to extend a previously published 2D coupled sub-sample tracking algorithm for 3D speckle tracking in the framework of ultrasound breast strain elastography. In order to overcome heavy computational cost, we investigated the use of a graphic processing unit (GPU) to accelerate the 3D coupled sub-sample speckle tracking method. The performance of the proposed GPU implementation was tested using a tissue-mimicking (TM) phantom and in vivo breast ultrasound data. The performance of this 3D sub-sample tracking algorithm was compared with the conventional 3D quadratic sub-sample estimation algorithm. On the basis of these evaluations, we concluded that the GPU implementation of this 3D sub-sample estimation algorithm can provide high-quality strain data (i.e. high correlation between the pre- and the motion-compensated post-deformation RF echo data and high contrast-to-noise ratio strain images), as compared to the conventional 3D quadratic sub-sample algorithm. Using the GPU implementation of the 3D speckle tracking algorithm, volumetric strain data can be achieved relatively fast (approximately 20 seconds per volume [2.5 cm × 2.5 cm × 2.5 cm]). PMID:28166493
Zhang, Zhongheng; Hong, Yucai
2017-07-25
There are several disease severity scores being used for the prediction of mortality in critically ill patients. However, none of them was developed and validated specifically for patients with severe sepsis. The present study aimed to develop a novel prediction score for severe sepsis. A total of 3206 patients with severe sepsis were enrolled, including 1054 non-survivors and 2152 survivors. The LASSO score showed the best discrimination (area under curve: 0.772; 95% confidence interval: 0.735-0.810) in the validation cohort as compared with other scores such as simplified acute physiology score II, acute physiological score III, Logistic organ dysfunction system, sequential organ failure assessment score, and Oxford Acute Severity of Illness Score. The calibration slope was 0.889 and Brier value was 0.173. The study employed a single center database called Medical Information Mart for Intensive Care-III) MIMIC-III for analysis. Severe sepsis was defined as infection and acute organ dysfunction. Clinical and laboratory variables used in clinical routines were included for screening. Subjects without missing values were included, and the whole dataset was split into training and validation cohorts. The score was coined LASSO score because variable selection was performed using the least absolute shrinkage and selection operator (LASSO) technique. Finally, the LASSO score was evaluated for its discrimination and calibration in the validation cohort. The study developed the LASSO score for mortality prediction in patients with severe sepsis. Although the score had good discrimination and calibration in a randomly selected subsample, external validations are still required.
Recognizing pedestrian's unsafe behaviors in far-infrared imagery at night
NASA Astrophysics Data System (ADS)
Lee, Eun Ju; Ko, Byoung Chul; Nam, Jae-Yeal
2016-05-01
Pedestrian behavior recognition is important work for early accident prevention in advanced driver assistance system (ADAS). In particular, because most pedestrian-vehicle crashes are occurred from late of night to early of dawn, our study focus on recognizing unsafe behavior of pedestrians using thermal image captured from moving vehicle at night. For recognizing unsafe behavior, this study uses convolutional neural network (CNN) which shows high quality of recognition performance. However, because traditional CNN requires the very expensive training time and memory, we design the light CNN consisted of two convolutional layers and two subsampling layers for real-time processing of vehicle applications. In addition, we combine light CNN with boosted random forest (Boosted RF) classifier so that the output of CNN is not fully connected with the classifier but randomly connected with Boosted random forest. We named this CNN as randomly connected CNN (RC-CNN). The proposed method was successfully applied to the pedestrian unsafe behavior (PUB) dataset captured from far-infrared camera at night and its behavior recognition accuracy is confirmed to be higher than that of some algorithms related to CNNs, with a shorter processing time.
We examined the effects of using a fixed-count subsample of 300 organisms on metric values using macroinvertebrate samples collected with 3 field sampling methods at 12 boatable river sites. For each sample, we used metrics to compare an initial fixed-count subsample of approxima...
Estimating the weight of Douglas-fir tree boles and logs with an iterative computer model.
Dale R. Waddell; Dale L Weyermann; Michael B. Lambert
1987-01-01
A computer model that estimates the green weights of standing trees was developed and validated for old-growth Douglas-fir. The model calculates the green weight for the entire bole, for the bole to any merchantable top, and for any log length within the bole. The model was validated by estimating the bias and accuracy of an independent subsample selected from the...
Herr, Raphael M; Li, Jian; Bosch, Jos A; Schmidt, Burkhard; DeJoy, David M; Fischer, Joachim E; Loerbroks, Adrian
2014-01-01
The objective of the present study was to validate a German 11-item organizational justice questionnaire (G-OJQ) that consists of two subscales, referred to as "procedural justice" (PJ) and "interactional justice" (IJ) adapted from Moorman's organizational justice (OJ) questionnaire. A second objective was to determine associations of the G-OJQ with self-rated health. This study used cross-sectional data from an occupational cohort of 1518 factory workers from Germany (87.7 % male; mean age = 38.8 with SD = 11.9). After splitting the sample in two random subsamples, we assessed structural validity by exploratory factor analyses in one subsample and by confirmatory factor analysis in the other subsample. Internal validity was assessed by Cronbach's α. Associations with self-reported poor health were estimated by logistic regression. The full scale and its subscales yielded Cronbach's α's of ≥0.9, and item-total correlations were ≥0.5. Factor analyses confirmed the expected 2-factor structure, labeled "interactional justice" (IJ, 4 items, λ 0.43-0.94) and "procedural justice" (PJ, 7 items, λ 0.46-0.83), respectively, and showed an acceptable fit to the data (χ (2) = 61; p = .001; CFI = 0.995; RMSEA = 0.037). The OJ total score as well as subscale scores in the lowest quartile, when compared to the highest quartile, was associated with an ≥2.3 increased odds of reporting poor health. The G-OJQ seems to be a valid and useful tool for observational and intervention studies in occupational settings. Future studies may additionally explore longitudinal associations and test the generalizability of the present findings to other populations and health outcomes.
NASA Astrophysics Data System (ADS)
Wason, H.; Herrmann, F. J.; Kumar, R.
2016-12-01
Current efforts towards dense shot (or receiver) sampling and full azimuthal coverage to produce high resolution images have led to the deployment of multiple source vessels (or streamers) across marine survey areas. Densely sampled marine seismic data acquisition, however, is expensive, and hence necessitates the adoption of sampling schemes that save acquisition costs and time. Compressed sensing is a sampling paradigm that aims to reconstruct a signal--that is sparse or compressible in some transform domain--from relatively fewer measurements than required by the Nyquist sampling criteria. Leveraging ideas from the field of compressed sensing, we show how marine seismic acquisition can be setup as a compressed sensing problem. A step ahead from multi-source seismic acquisition is simultaneous source acquisition--an emerging technology that is stimulating both geophysical research and commercial efforts--where multiple source arrays/vessels fire shots simultaneously resulting in better coverage in marine surveys. Following the design principles of compressed sensing, we propose a pragmatic simultaneous time-jittered time-compressed marine acquisition scheme where single or multiple source vessels sail across an ocean-bottom array firing airguns at jittered times and source locations, resulting in better spatial sampling and speedup acquisition. Our acquisition is low cost since our measurements are subsampled. Simultaneous source acquisition generates data with overlapping shot records, which need to be separated for further processing. We can significantly impact the reconstruction quality of conventional seismic data from jittered data and demonstrate successful recovery by sparsity promotion. In contrast to random (sub)sampling, acquisition via jittered (sub)sampling helps in controlling the maximum gap size, which is a practical requirement of wavefield reconstruction with localized sparsifying transforms. We illustrate our results with simulations of simultaneous time-jittered marine acquisition for 2D and 3D ocean-bottom cable survey.
Lera, Lydia; Albala, Cecilia; Ángel, Bárbara; Sánchez, Hugo; Picrin, Yaisy; Hormazabal, María José; Quiero, Andrea
2014-03-01
To develop a predictive model of appendicular skeletal muscle mass (ASM) based on anthropometric measurements in elderly from Santiago, Chile. 616 community dwelling, non-disabled subjects ≥ 60 years (mean 69.9 ± 5.2 years) living in Santiago, 64.6% female, participating in ALEXANDROS study. Anthropometric measurements, handgrip strength, mobility tests and DEXA were performed. Step by step linear regression models were used to associate ASM from DEXA with anthropometric variables, age and sex. The sample was divided at random into two to obtain prediction equations for both subsamples, which were mutually validated by double cross-validation. The high correlation between the values of observed and predicted MMAE in both sub-samples and the low degree of shrinkage allowed developing the final prediction equation with the total sample. The cross-validity coefficient between prediction models from the subsamples (0.941 and 0.9409) and the shrinkage (0.004 and 0.006) were similar in both equations. The final prediction model obtained from the total sample was: ASM (kg) = 0.107(weight in kg) + 0.251( knee height in cm) + 0.197 (Calf Circumference in cm) +0.047 (dynamometry in kg) - 0.034 (Hip Circumference in cm) + 3.417 (Man) - 0.020 (age years) - 7.646 (R2 = 0.89). The mean ASM obtained by the prediction equation and the DEXA measurement were similar (16.8 ± 4.0 vs 16.9 ± 3.7) and highly concordant according Bland and Altman (95% CI: -2.6 -2.7) and Lin (concordance correlation coefficient = 0.94) methods. We obtained a low cost anthropometric equation to determine the appendicular skeletal muscle mass useful for the screening of sarcopenia in older adults. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.
Leombruni, Paolo; Loera, Barbara; Miniotti, Marco; Zizzi, Francesca; Castelli, Lorys; Torta, Riccardo
2015-10-01
A steady increase in the number of patients requiring end-of-life care has been observed during the last decades. The assessment of healthcare students' attitudes toward end-of-life care is an important step in their curriculum, as it provides information about their disposition to practice palliative medicine. The Frommelt Attitude Toward Care of the Dying Scale (FATCOD-B) was developed to detect such a disposition, but its psychometric properties are yet to be clearly defined. A convenience sample of 608 second-year medical students participated in our study in the 2012/2013 and 2013/2014 academic years. All participants completed the FATCOD-B. The sample was randomly divided in two subsamples. In the item analysis, reliability (Cronbach's α), internal consistency (item-total correlations), and an exploratory factor analysis (EFA) were conducted using the first subsample (n = 300). Using the second subsample (n = 308), confirmatory factor analysis (CFA) was performed using the robust ML method in the Lisrel program. Reliability for all items was 0.699. Item-total correlations, ranging from 0.03 to 0.39, were weak. EFA identified a two-dimensional orthogonal solution, explaining 20% of total variance. CFA upheld the two-dimensional model, but the loadings on the dimensions and their respective indicators were weak and equal to zero for certain items. The findings of the present study suggest that the FATCOD-B measures a two-dimensional construct and that several items seem in need of revision. Future research oriented toward building a revised version of the scale should pay attention to item ambiguity and take particular care to distinguish among items that concern emotions and beliefs related to end-of-life care, as well as their subjects (e.g., the healthcare provider, the patient, his family).
Spatial grain and the causes of regional diversity gradients in ants.
Kaspari, Michael; Yuan, May; Alonso, Leeanne
2003-03-01
Gradients of species richness (S; the number of species of a given taxon in a given area and time) are ubiquitous. A key goal in ecology is to understand whether and how the many processes that generate these gradients act at different spatial scales. Here we evaluate six hypotheses for diversity gradients with 49 New World ant communities, from tundra to rain forest. We contrast their performance at three spatial grains from S(plot), the average number of ant species nesting in a m2 plot, through Fisher's alpha, an index that treats our 30 1-m2 plots as subsamples of a locality's diversity. At the smallest grain, S(plot), was tightly correlated (r2 = 0.99) with colony abundance in a fashion indistinguishable from the packing of randomly selected individuals into a fixed space. As spatial grain increased, the coaction of two factors linked to high net rates of diversification--warm temperatures and large areas of uniform climate--accounted for 75% of the variation in Fisher's alpha. However, the mechanisms underlying these correlations (i.e., precisely how temperature and area shape the balance of speciation to extinction) remain elusive.
Studdert, Lisa J; Soekirman; Rasmussen, Kathleen M; Habicht, Jean-Pierre
2004-06-01
The Indonesian Government initiated a community-based national school-feeding program in 1996. Implementation was decentralized and involved multiple participants. In 1998 we evaluated the implementation of the program and the perceived benefits for community stakeholders using a survey of principals in 143 randomly selected schools and follow-up with in-depth interviews and observations in a subsample of 16 communities. The evaluation covered the period of the 1998 Asian economic crisis, affording the opportunity to assess its impact on the program. The program was implemented in all targeted schools, with excellent community participation. Feeding was sustained through the crisis, in spite of a dramatic escalation in food costs. The families of schoolchildren, farmers, and those who prepared food received economic benefits. The snacks replaced those sold at schools and were of better nutritional value. The children benefited because the snacks compensated for losses in the home diet resulting from the economic crisis. Characteristics of the program that may be important in explaining its success include the involvement of a range of community stakeholders, engagement with existing village administrative structures, scope for local community adaptation and innovation, and the use of local foods that dispersed benefits and ensured sustained implementation during the crisis.
Lalani, Mirza; Kaur, Harparkash; Mohammed, Nader; Mailk, Naiela; van Wyk, Albert; Jan, Sakhi; Kakar, Rishtya Meena; Mojadidi, Mohammed Khalid; Leslie, Toby
2015-01-01
Good-quality antimalarials are crucial for the effective treatment and control of malaria. A total of 7,740 individual and packaged tablets, ampoules, and syrups were obtained from 60 randomly selected public (N = 35) and private outlets (N = 25) in Afghanistan. Of these, 134 samples were screened using the Global Pharma Health Fund (GPHF) MiniLab® in Kabul with 33/126 (26%) samples failing the MiniLab® disintegration test. The quality of a subsample (N = 37) of cholorquine, quinine, and sulfadoxine/pyrimethamine tablets was assessed by in vitro dissolution testing following U.S. Pharmacopeia (USP) monographs at a bioanalytical laboratory in London, United Kingdom. Overall, 12/32 (32%) samples of sulfadoxine/pyrimethamine and quinine were found not to comply with the USP tolerance limits. Substandard antimalarials were available in Afghanistan demonstrating that continuous monitoring of drug quality is warranted. However, in Afghanistan as in many low-income countries, capacity to determine and monitor drug quality using methods such as dissolution testing needs to be established to empower national authorities to take appropriate action in setting up legislation and regulation. PMID:25897070
Johnsson, Kent O; Leifman, Anders; Berglund, Mats
2008-01-01
Changes in AUDIT score trajectories were examined in a student population during their first 4 years at a university, including high-risk consumers and a subsample of low-risk consumers. 359 students were selected for the present study, comprising all high-risk consumers (the 27% with highest scores, i.e. 11 for males and 7 for females) and a randomized sample of low-risk consumers (n = 177 and 182, respectively). The Alcohol Use Disorder Identification Test (AUDIT) was used as screening instrument. Trajectory analyses were made using a semiparametric group-based model. In the low-AUDIT group, five distinct trajectories were identified: three stable non-risky consumption groups (83%) and two increasing groups (17%; from non-risky to risky). In the high-AUDIT group, three groups were identified: two stable high groups (58%) and one decreasing group (from risky to non-risky consumption; 41%). In the integrated model, stable risky consumption comprised 16% of the total sample, decreasing consumption 11%, increasing consumption comprised 13% and stable non-risky consumption 60% of the sample. Gender influenced the trajectories. The pattern of changes in risk consumption is similar to that found in corresponding US studies. (c) 2008 S. Karger AG, Basel
Validation of a short qualitative food frequency list used in several German large scale surveys.
Winkler, G; Döring, A
1998-09-01
Our study aimed to test the validity of a short, qualitative food frequency list (FFL) used in several German large scale surveys. In the surveys of the MONICA project Augsburg, the FFL was used in randomly selected adults. In 1984/85, a dietary survey with 7-day records (DR) was conducted within the subsample of men aged 45 to 64 (response 70%). The 899 DR were used to validate the FFL. Mean weekly food intake frequency and mean daily food intake were compared and Spearman rank order correlation coefficients and classification into tertiles with values of the statistic Kappa were calculated. Spearman correlations range between 0.15 for the item "Other sweets (candies, compote)" and 0.60 for the items "Curds, yoghurt, sour milk", "Milk including butter milk" and "Mineral water"; values for statistic Kappa vary between 0.04 ("White bread, brown bread, crispbread") and 0.41 ("Flaked oats, muesli, cornflakes" and "milk including butter milk"). With the exception of two items, FFL data can be used for analysis on group level. Analysis on individual level should be done with caution. It seems, as if some food groups are generally easier to ask for in FFL than others.
Pillay, Pavitra; Taylor, Myra; Zulu, Siphosenkosi G.; Gundersen, Svein G.; Verweij, Jaco J.; Hoekstra, Pytsje; Brienen, Eric A. T.; Kleppa, Elisabeth; Kjetland, Eyrun F.; van Lieshout, Lisette
2014-01-01
Schistosoma haematobium eggs and Schistosoma DNA levels were measured in urine samples from 708 girls recruited from 18 randomly sampled primary schools in South Africa. Microscopic analysis of two 10-mL urine subsamples collected on three consecutive days confirmed high day-to-day variation; 103 (14.5%) girls had positive results at all six examinations, and at least one positive sample was seen in 225 (31.8%) girls. Schistosoma-specific DNA, which was measured in a 200-μL urine subsample by using real-time polymerase chain reaction, was detected in 180 (25.4%) cases, and levels of DNA corresponded significantly with average urine egg excretion. In concordance with microscopic results, polymerase chain reaction results were significantly associated with history of gynecologic symptoms and confirmed highly focal distribution of urogenital schistosomiasis. Parasite-specific DNA detection has a sensitivity comparable to single urine microscopy and could be used as a standardized high-throughput procedure to assess distribution of urogenital schistosomiasis in relatively large study populations by using small sample volumes. PMID:24470560
A study of depression among Alexandria preparatory school adolescents.
Abou Nazel, M W; Fahmy, S I; Younis, I A; Seif el-Din, A G; Abdel Fatah, M; Mokhtar, S; Ayoub, A I
1991-01-01
Using a constructed Arabic version of Children Depression Inventory (CDI), screening of a stratified random sample of 1% (1561) of Alexandria Preparatory school adolescents was carried out. The prevalence of depressive scorers was 10.25% of total sample. A sub-sample of depressed scorers (111 pupils) were compared with controls (non-depressed scorers) matched on age and sex to study a variety of personal, familial, medical and scholastic ecological variables. Pupils neuroticism scorers were most predictive of depressive scorers where they explained 59.79% of the variance. Other ecological factors including peer and sibling relationships, introversive and lie scale scorers and scholastic performance explained an additional 14.87% of the variance. Using Beck Depression Inventory (BDI) and Mother-Father relationship check list, a sub-sample of depressed pupils' mothers were compared with controls of non-depressed pupils' mothers (42 mothers for each). Results indicated a strong positive correlation between pupils, CDI scores and their mothers BDI scores. On the other hand poor mother-father relationship was significantly associated with depressive scores of pupils. Findings, pointed to the need for reconsideration of school mental health program, since the presented medical and social services to depressed pupils were very poor.
NASA Astrophysics Data System (ADS)
Engstrom, R.; Soundararajan, V.; Newhouse, D.
2017-12-01
In this study we examine how well multiple population density and built up estimates that utilize satellite data compare in Sri Lanka. The population relationship is examined at the Gram Niladhari (GN) level, the lowest administrative unit in Sri Lanka from the 2011 census. For this study we have two spatial domains, the whole country and a 3,500km2 sub-sample, for which we have complete high spatial resolution imagery coverage. For both the entire country and the sub-sample we examine how consistent are the existing publicly available measures of population constructed from satellite imagery at predicting population density? For just the sub-sample we examine how well do a suite of values derived from high spatial resolution satellite imagery predict population density and how does our built up area estimate compare to other publicly available estimates. Population measures were obtained from the Sri Lankan census, and were downloaded from Facebook, WorldPoP, GPW, and Landscan. Percentage built-up area at the GN level was calculated from three sources: Facebook, Global Urban Footprint (GUF), and the Global Human Settlement Layer (GHSL). For the sub-sample we have derived a variety of indicators from the high spatial resolution imagery. Using deep learning convolutional neural networks, an object oriented, and a non-overlapping block, spatial feature approach. Variables calculated include: cars, shadows (a proxy for building height), built up area, and buildings, roof types, roads, type of agriculture, NDVI, Pantex, and Histogram of Oriented Gradients (HOG) and others. Results indicate that population estimates are accurate at the higher, DS Division level but not necessarily at the GN level. Estimates from Facebook correlated well with census population (GN correlation of 0.91) but measures from GPW and WorldPop are more weakly correlated (0.64 and 0.34). Estimates of built-up area appear to be reliable. In the 32 DSD-subsample, Facebook's built- up area measure is highly correlated with our built-up measure (correlation of 0.9). Preliminary regression results based on variables selected from Lasso-regressions indicate that satellite indicators have exceptionally strong predictive power in predicting GN level population level and density with an out of sample r-squared of 0.75 and 0.72 respectively.
Low-Power SOI CMOS Transceiver
NASA Technical Reports Server (NTRS)
Fujikawa, Gene (Technical Monitor); Cheruiyot, K.; Cothern, J.; Huang, D.; Singh, S.; Zencir, E.; Dogan, N.
2003-01-01
The work aims at developing a low-power Silicon on Insulator Complementary Metal Oxide Semiconductor (SOI CMOS) Transceiver for deep-space communications. RF Receiver must accomplish the following tasks: (a) Select the desired radio channel and reject other radio signals, (b) Amplify the desired radio signal and translate them back to baseband, and (c) Detect and decode the information with Low BER. In order to minimize cost and achieve high level of integration, receiver architecture should use least number of external filters and passive components. It should also consume least amount of power to minimize battery cost, size, and weight. One of the most stringent requirements for deep-space communication is the low-power operation. Our study identified that two candidate architectures listed in the following meet these requirements: (1) Low-IF receiver, (2) Sub-sampling receiver. The low-IF receiver uses minimum number of external components. Compared to Zero-IF (Direct conversion) architecture, it has less severe offset and flicker noise problems. The Sub-sampling receiver amplifies the RF signal and samples it using track-and-hold Subsampling mixer. These architectures provide low-power solution for the short- range communications missions on Mars. Accomplishments to date include: (1) System-level design and simulation of a Double-Differential PSK receiver, (2) Implementation of Honeywell SOI CMOS process design kit (PDK) in Cadence design tools, (3) Design of test circuits to investigate relationships between layout techniques, geometry, and low-frequency noise in SOI CMOS, (4) Model development and verification of on-chip spiral inductors in SOI CMOS process, (5) Design/implementation of low-power low-noise amplifier (LNA) and mixer for low-IF receiver, and (6) Design/implementation of high-gain LNA for sub-sampling receiver. Our initial results show that substantial improvement in power consumption is achieved using SOI CMOS as compared to standard CMOS process. Potential advantages of SOI CMOS for deep-space communication electronics include: (1) Radiation hardness, (2) Low-power operation, and (3) System-on-Chip (SOC) solutions.
Inferring collective dynamical states from widely unobserved systems.
Wilting, Jens; Priesemann, Viola
2018-06-13
When assessing spatially extended complex systems, one can rarely sample the states of all components. We show that this spatial subsampling typically leads to severe underestimation of the risk of instability in systems with propagating events. We derive a subsampling-invariant estimator, and demonstrate that it correctly infers the infectiousness of various diseases under subsampling, making it particularly useful in countries with unreliable case reports. In neuroscience, recordings are strongly limited by subsampling. Here, the subsampling-invariant estimator allows to revisit two prominent hypotheses about the brain's collective spiking dynamics: asynchronous-irregular or critical. We identify consistently for rat, cat, and monkey a state that combines features of both and allows input to reverberate in the network for hundreds of milliseconds. Overall, owing to its ready applicability, the novel estimator paves the way to novel insight for the study of spatially extended dynamical systems.
A prototype splitter apparatus for dividing large catches of small fish
Stapanian, Martin A.; Edwards, William H.
2012-01-01
Due to financial and time constraints, it is often necessary in fisheries studies to divide large samples of fish and estimate total catch from the subsample. The subsampling procedure may involve potential human biases or may be difficult to perform in rough conditions. We present a prototype gravity-fed splitter apparatus for dividing large samples of small fish (30–100 mm TL). The apparatus features a tapered hopper with a sliding and removable shutter. The apparatus provides a comparatively stable platform for objectively obtaining subsamples, and it can be modified to accommodate different sizes of fish and different sample volumes. The apparatus is easy to build, inexpensive, and convenient to use in the field. To illustrate the performance of the apparatus, we divided three samples (total N = 2,000 fish) composed of four fish species. Our results indicated no significant bias in estimating either the number or proportion of each species from the subsample. Use of this apparatus or a similar apparatus can help to standardize subsampling procedures in large surveys of fish. The apparatus could be used for other applications that require dividing a large amount of material into one or more smaller subsamples.
Effects of subsampling of passive acoustic recordings on acoustic metrics.
Thomisch, Karolin; Boebel, Olaf; Zitterbart, Daniel P; Samaran, Flore; Van Parijs, Sofie; Van Opzeeland, Ilse
2015-07-01
Passive acoustic monitoring is an important tool in marine mammal studies. However, logistics and finances frequently constrain the number and servicing schedules of acoustic recorders, requiring a trade-off between deployment periods and sampling continuity, i.e., the implementation of a subsampling scheme. Optimizing such schemes to each project's specific research questions is desirable. This study investigates the impact of subsampling on the accuracy of two common metrics, acoustic presence and call rate, for different vocalization patterns (regimes) of baleen whales: (1) variable vocal activity, (2) vocalizations organized in song bouts, and (3) vocal activity with diel patterns. To this end, above metrics are compared for continuous and subsampled data subject to different sampling strategies, covering duty cycles between 50% and 2%. The results show that a reduction of the duty cycle impacts negatively on the accuracy of both acoustic presence and call rate estimates. For a given duty cycle, frequent short listening periods improve accuracy of daily acoustic presence estimates over few long listening periods. Overall, subsampling effects are most pronounced for low and/or temporally clustered vocal activity. These findings illustrate the importance of informed decisions when applying subsampling strategies to passive acoustic recordings or analyses for a given target species.
Robust model selection and the statistical classification of languages
NASA Astrophysics Data System (ADS)
García, J. E.; González-López, V. A.; Viola, M. L. L.
2012-10-01
In this paper we address the problem of model selection for the set of finite memory stochastic processes with finite alphabet, when the data is contaminated. We consider m independent samples, with more than half of them being realizations of the same stochastic process with law Q, which is the one we want to retrieve. We devise a model selection procedure such that for a sample size large enough, the selected process is the one with law Q. Our model selection strategy is based on estimating relative entropies to select a subset of samples that are realizations of the same law. Although the procedure is valid for any family of finite order Markov models, we will focus on the family of variable length Markov chain models, which include the fixed order Markov chain model family. We define the asymptotic breakdown point (ABDP) for a model selection procedure, and we show the ABDP for our procedure. This means that if the proportion of contaminated samples is smaller than the ABDP, then, as the sample size grows our procedure selects a model for the process with law Q. We also use our procedure in a setting where we have one sample conformed by the concatenation of sub-samples of two or more stochastic processes, with most of the subsamples having law Q. We conducted a simulation study. In the application section we address the question of the statistical classification of languages according to their rhythmic features using speech samples. This is an important open problem in phonology. A persistent difficulty on this problem is that the speech samples correspond to several sentences produced by diverse speakers, corresponding to a mixture of distributions. The usual procedure to deal with this problem has been to choose a subset of the original sample which seems to best represent each language. The selection is made by listening to the samples. In our application we use the full dataset without any preselection of samples. We apply our robust methodology estimating a model which represent the main law for each language. Our findings agree with the linguistic conjecture, related to the rhythm of the languages included on our dataset.
Sampling design by the core-food approach for the Taiwan total diet study on veterinary drugs.
Chen, Chien-Chih; Tsai, Ching-Lun; Chang, Chia-Chin; Ni, Shih-Pei; Chen, Yi-Tzu; Chiang, Chow-Feng
2017-06-01
The core-food (CF) approach, first adopted in the United States in the 1980s, has been widely used by many countries to assess the exposure to dietary hazards at a population level. However, the reliability of exposure estimates (C × CR) depends critically on sampling methods designed for the detected chemical concentrations (C) of each CF to match with the corresponding consumption rate (CR) estimated from the surveyed intake data. In order to reduce the uncertainty of food matching, this study presents a sampling design scheme, namely the subsample method, for the 2016 Taiwan total diet study (TDS) on veterinary drugs. We first combined the four sets of national dietary recall data that covered the entire age strata (1-65+ years), and aggregated them into 307 CFs by their similarity in nutritional values, manufacturing and cooking methods. The 40 CFs pertinent to veterinary drug residues were selected for this study, and 16 subsamples for each CF were designed by weighing their quantities in CR, product brands, manufacturing, processing and cooking methods. The calculated food matching rates of each CF from this study were 84.3-97.3%, which were higher than those obtained from many previous studies using the representative food (RF) method (53.1-57.8%). The subsample method not only considers the variety of food processing and cooking methods, but also it provides better food matching and reduces the uncertainty of exposure assessment.
Biomotor status and kinesiological education of girls aged 10 to 12 years--example: volleyball.
Milić, Mirjana; Grgantov, Zoran; Katić, Ratko
2012-09-01
The aim of this study was to define processes of orientation and/or selection towards sports game of volleyball in schoolgirls of Kastela, aged 10-12, by examining the relations between regular classes of physical education (PE) and extracurricular sport activities. For this purpose, two morphological measures were used (body height and body mass) and a set of 11 motor tests (6 basic motor abilities tests and 5 motor achievement tests) on a sample of 242 girls aged 10-12 was used, divided into a subsample of 42 girls participating in volleyball training (Volleyball players) and a subsample of 200 girls who do not participate in volleyball training (volleyball non-players). Based on the comparison of test results of schoolgirls from Kastela and Croatian norms, factor analysis of applied variables and discriminant analysis of these variables between volleyball players and non-players, processes and/or phases of selection in forming quality volleyball players were defined. Selection processes are preceded by orientation processes in physical education classes, i.e. choosing those sport activities which are in accordance with the biomotor status of students. Results have shown that orientation and initial selection in female volleyball needs to be executed based on the motor set of psychomotor speed, repetitive strength of the trunk and flexibility (muscle tone regulation), and body height. Volleyball training has affected the muscle mass development and the development of strength factors, so that explosive strength of jumping and/or takeoff along with body height, has predominantly differentiated female volleyball players from non-players, aged 10 to 12, and serve and spike quality will have dominant influence on the match outcome.
[Participation of migrants in health surveys conducted by telephone: potential and limits].
Schenk, L; Neuhauser, H
2005-10-01
Migrants living in Germany are a both large and vulnerable population subgroup. They are not easily induced to participate in health surveys, Hence, achieving high participation rates of migrants in health surveys and avoiding selection bias is a difficult task. In this study, we report on the participation of migrants in the German National Health Telephone Survey 2003 (GSTel03), the first comprehensive national health survey conducted by telephone in Germany. Three migrant groups were identified: individuals with non-German citizenship (foreigners), naturalized migrants, and ethnic German immigrants (Spätaussiedler). The aim of this study is to evaluate the degree to which the GSTel03 subsample of foreigners is representative for foreigners living in Germany. We compare the prevalence of sociodemographic characteristics and selected health indicators of foreigners in the GNTel03 subsample with prevalences from national statistics and from a large national household survey ("Mikrozensus 2003"). The proportion of participants with non-German nationality in the overall GSTel03 sample was significantly lower than the proportion of foreigners in the residential population in Germany (3.7 % vs. 8.9 %). While there was no evidence of selection bias with regard to age and sex distribution, we found significant differences with regard to other factors, including nationality, length of stay in Germany, unemployment rate and education. The comparison of health indicators showed only moderate differences between GSTel03 sample and "Mikrozensus" results. However, these differences did not consistently point to a better or worse health status in the GSTel03 sample of foreigners and should therefore not be generalised in respect of other health indicators. Our study emphasises the importance of a continuous effort to improve migrant participation in health studies and of a thorough analysis of selection bias when interpreting results.
The mental health of UK Gulf war veterans: phase 2 of a two phase cohort study.
Ismail, Khalida; Kent, Kate; Brugha, Traolach; Hotopf, Matthew; Hull, Lisa; Seed, Paul; Palmer, Ian; Reid, Steve; Unwin, Catherine; David, Anthony S; Wessely, Simon
2002-09-14
To examine the prevalence of psychiatric disorders in veterans of the Gulf war with or without unexplained physical disability (a proxy measure of ill health) and in similarly disabled veterans who had not been deployed to the Gulf war (non-Gulf veterans). Two phase cohort study. Current and ex-service UK military personnel. Phase 1 consisted of three randomly selected samples of Gulf veterans, veterans of the 1992-7 Bosnia peacekeeping mission, and UK military personnel not deployed to the Gulf war (Era veterans) who had completed a postal health questionnaire. Phase 2 consisted of randomly selected subsamples from phase 1 of Gulf veterans who reported physical disability (n=111) or who did not report disability (n=98) and of Bosnia (n=54) and Era (n=79) veterans who reported physical disability. Psychiatric disorders assessed by the schedule for clinical assessment in neuropsychiatry and classified by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition. Only 24% (n=27) of the disabled Gulf veterans had a formal psychiatric disorder (depression, anxiety, or alcohol related disorder). The prevalence of psychiatric disorders in non-disabled Gulf veterans was 12%. Disability and psychiatric disorders were weakly associated in the Gulf group when confounding was adjusted for (adjusted odds ratio 2.4, 99% confidence interval 0.8 to 7.2, P=0.04). The prevalence of psychiatric disorders was similar in disabled non-Gulf veterans and disabled Gulf veterans ( 19% v 24%; 1.3, 0.5 to 3.4). All groups had rates for post-traumatic stress disorder of between 1% and 3%. Most disabled Gulf veterans do not have a formal psychiatric disorder. Post-traumatic stress disorder is not higher in Gulf veterans than in other veterans. Psychiatric disorders do not fully explain self reported ill health in Gulf veterans; alternative explanations for persistent ill health in Gulf veterans are needed.
Schröter, Hannes; Studzinski, Beatrix; Dietz, Pavel; Ulrich, Rolf; Striegel, Heiko; Simon, Perikles
2016-01-01
Purpose This study assessed the prevalence of physical and cognitive doping in recreational triathletes with two different randomized response models, that is, the Cheater Detection Model (CDM) and the Unrelated Question Model (UQM). Since both models have been employed in assessing doping, the major objective of this study was to investigate whether the estimates of these two models converge. Material and Methods An anonymous questionnaire was distributed to 2,967 athletes at two triathlon events (Frankfurt and Wiesbaden, Germany). Doping behavior was assessed either with the CDM (Frankfurt sample, one Wiesbaden subsample) or the UQM (one Wiesbaden subsample). A generalized likelihood-ratio test was employed to check whether the prevalence estimates differed significantly between models. In addition, we compared the prevalence rates of the present survey with those of a previous study on a comparable sample. Results After exclusion of incomplete questionnaires and outliers, the data of 2,017 athletes entered the final data analysis. Twelve-month prevalence for physical doping ranged from 4% (Wiesbaden, CDM and UQM) to 12% (Frankfurt CDM), and for cognitive doping from 1% (Wiesbaden, CDM) to 9% (Frankfurt CDM). The generalized likelihood-ratio test indicated no differences in prevalence rates between the two methods. Furthermore, there were no significant differences in prevalences between the present (undertaken in 2014) and the previous survey (undertaken in 2011), although the estimates tended to be smaller in the present survey. Discussion The results suggest that the two models can provide converging prevalence estimates. The high rate of cheaters estimated by the CDM, however, suggests that the present results must be seen as a lower bound and that the true prevalence of doping might be considerably higher. PMID:27218830
Feasibility of a Trial on Improvisational Music Therapy for Children with Autism Spectrum Disorder.
Geretsegger, Monika; Holck, Ulla; Bieleninik, Łucja; Gold, Christian
2016-01-01
To conduct generalizable, rigorously designed, adequately powered trials investigating music therapy and other complex interventions, it is essential that study procedures are feasible and acceptable for participants. To date, only limited evidence on feasibility of trial designs and strategies to facilitate study implementation is available in the music therapy literature. Using data from a subsample of a multi-center RCT on improvisational music therapy (IMT) for autism spectrum disorder (ASD), this study aims to evaluate feasibility of study procedures, evaluate safety, document concomitant treatment, and report consistency of individuals' trends over time in chosen outcome measures. Children with ASD aged between 4 years, 0 months, and 6 years, 11 months, were randomly assigned to one of three conditions: one (low intensity) vs. three weekly IMT sessions (high intensity) for five months vs. standard care. Feasibility was evaluated by examining recruitment, implementation of study conditions, assessment procedures, blinding, and retention; we also evaluated safety, concomitant treatment, and consistency of changes in standardized scales completed by blinded assessors and parents before and 5 months after randomization. Within this subsample (n = 15), recruitment rates, session attendance in the high-intensity condition, and consistency between outcome measures were lower than expected. Session attendance in the low-intensity and control conditions, treatment fidelity, measurement completion, blinding, retention, and safety met a priori thresholds for feasibility. By discussing strategies to improve recruitment and to minimize potential burden on study participants, referrers, and researchers, this study helps build knowledge about designing and implementing trials successfully. © the American Music Therapy Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
A dietary supplement to improve the quality of sleep: a randomized placebo controlled trial
2010-01-01
Background To evaluate the effect of a dietary supplement containing polyunsaturated fatty acids, in association with Humulus lupulus extract, on the quality of sleep using the Leeds sleep evaluation questionnaire (LSEQ) in subjects with moderate to severe sleep disorders. Methods Randomized placebo-controlled trial, in a Population-based setting. Participants were adult patients 25 to 65 years old with a chronic primary insomnia who volunteered for the study. The tested intervention consisted of two soft gelatine capsules per day, containing either the dietary supplement (active group) or olive oil (placebo group) for a month. Subjects could also volunteer for two ancillary studies on melatonin and actigraphy. Evaluation criteria included i) perception of the quality of sleep at the end of treatment using the LSEQ questionnaire, ii) sleep efficiency measured by one-week actigraphic movement measurement performed before and during the treatment in a subsample of subjects, iii) night melatonin and 6 sulfatoxymelatonin (aMT6S) urine rates in a subsample of subjects. Results The average of Leeds score was similar in both groups (p = 0.95). A marked improvement in the quality of sleep was observed in both placebo (62%) and active (65%) group (p = 0.52). The evolution of urinary melatonin, aMT6S, and of the Mel/aMT6S ratio showed no differences between the two groups. Sleep efficiency, as measured by actigraphy, improved similarly in both groups during the treatment period, from 72% to 76% and 75% in the active and placebo group respectively (p = 0.91). Conclusions The dietary supplement had neither effect on the perceived quality of sleep, nor on the melatonin metabolism and sleep-wake cycle. Trial registration: clinical trials.gov:NCT00484497 PMID:20569455
A dietary supplement to improve the quality of sleep: a randomized placebo controlled trial.
Cornu, Catherine; Remontet, Laurent; Noel-Baron, Florence; Nicolas, Alain; Feugier-Favier, Nathalie; Roy, Pascal; Claustrat, Bruno; Saadatian-Elahi, Mitra; Kassaï, Behrouz
2010-06-22
To evaluate the effect of a dietary supplement containing polyunsaturated fatty acids, in association with Humulus lupulus extract, on the quality of sleep using the Leeds sleep evaluation questionnaire (LSEQ) in subjects with moderate to severe sleep disorders. Randomized placebo-controlled trial, in a Population-based setting. Participants were adult patients 25 to 65 years old with a chronic primary insomnia who volunteered for the study. The tested intervention consisted of two soft gelatine capsules per day, containing either the dietary supplement (active group) or olive oil (placebo group) for a month. Subjects could also volunteer for two ancillary studies on melatonin and actigraphy. Evaluation criteria included i) perception of the quality of sleep at the end of treatment using the LSEQ questionnaire, ii) sleep efficiency measured by one-week actigraphic movement measurement performed before and during the treatment in a subsample of subjects, iii) night melatonin and 6 sulfatoxymelatonin (aMT6S) urine rates in a subsample of subjects. The average of Leeds score was similar in both groups (p = 0.95). A marked improvement in the quality of sleep was observed in both placebo (62%) and active (65%) group (p = 0.52). The evolution of urinary melatonin, aMT6S, and of the Mel/aMT6S ratio showed no differences between the two groups. Sleep efficiency, as measured by actigraphy, improved similarly in both groups during the treatment period, from 72% to 76% and 75% in the active and placebo group respectively (p = 0.91). The dietary supplement had neither effect on the perceived quality of sleep, nor on the melatonin metabolism and sleep-wake cycle. clinical trials.gov:NCT00484497.
Siddiqui, Meena; Vakoc, Benjamin J.
2012-01-01
Recent advances in optical coherence tomography (OCT) have led to higher-speed sources that support imaging over longer depth ranges. Limitations in the bandwidth of state-of-the-art acquisition electronics, however, prevent adoption of these advances into the clinical applications. Here, we introduce optical-domain subsampling as a method for imaging at high-speeds and over extended depth ranges but with a lower acquisition bandwidth than that required using conventional approaches. Optically subsampled laser sources utilize a discrete set of wavelengths to alias fringe signals along an extended depth range into a bandwidth limited frequency window. By detecting the complex fringe signals and under the assumption of a depth-constrained signal, optical-domain subsampling enables recovery of the depth-resolved scattering signal without overlapping artifacts from this bandwidth-limited window. We highlight key principles behind optical-domain subsampled imaging, and demonstrate this principle experimentally using a polygon-filter based swept-source laser that includes an intra-cavity Fabry-Perot (FP) etalon. PMID:23038343
Warthon-Medina, Marisol; Qualter, Pamela; Zavaleta, Nelly; Dillon, Stephanie; Lazarte, Fabiola; Lowe, Nicola M.
2015-01-01
Brain growth and development are critically dependent on several micronutrients. During early development cellular activity may be sensitive to micronutrient deficiencies, however the evidence from human studies is equivocal. The objective of this study was to examine the long-term cognitive and social-emotional effects of multiple micronutrient supplementation compared with iron supplementation alone, administered during infancy. This study was a follow-up to an initial randomized, double-blind controlled trial (RCT) in 2010 in which 902 infants, aged 6–17 months, from Lima, Peru, were given daily supplements of either iron (Fe) or multiple micronutrients (MMN) including zinc (451 in each group). The supplementation period for both groups was six months. In 2012, a subsample of 184 children from the original cohort (now aged 36–48 months) was randomly selected to participate in a follow-up trial and was assessed for intelligence, working memory, inhibition, and executive function. The tests showed no significant differences between the supplementation groups though there were some gender differences, with girls displaying higher scores than boys across both groups on the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) Verbal IQ sentences subtest, the Day-Night cognitive test and on the Brief Infant-Toddler Social Emotional Assessment (BITSEA) social competency, and boys scoring higher than girls in problem behaviour. The results indicate that MMN supplementation had no long term additional effects on cognitive function compared with iron supplementation alone. The timing of supplement administration for maximum impact on a child’s cognitive development requires further investigation. PMID:26262642
Health-risk behaviour in Croatia.
Bécue-Bertaut, Mónica; Kern, Josipa; Hernández-Maldonado, Maria-Luisa; Juresa, Vesna; Vuletic, Silvije
2008-02-01
To identify the health-risk behaviour of various homogeneous clusters of individuals. The study was conducted in 13 of the 20 Croatian counties and in Zagreb, the Croatian capital. In the first stage, general practices were selected in each county. The second-stage sample was created by drawing a random subsample of 10% of the patients registered at each selected general practice. The sample was divided into seven homogenous clusters using statistical methodology, combining multiple factor analysis with a hybrid clustering method. Seven homogeneous clusters were identified, three composed of males and four composed of females, based on statistically significant differences between selected characteristics (P<0.001). Although, in general, self-assessed health declined with age, significant variations were observed within specific age intervals. Higher levels of self-assessed health were associated with higher levels of education and/or socio-economic status. Many individuals, especially females, who self-reported poor health were heavy consumers of sleeping pills. Males and females reported different health-risk behaviours related to lifestyle, diet and use of the healthcare system. Heavy alcohol and tobacco use, unhealthy diet, risky physical activity and non-use of the healthcare system influenced self-assessed health in males. Females were slightly less satisfied with their health than males of the same age and educational level. Even highly educated females who took preventive healthcare tests and ate a healthy diet reported a less satisfactory self-assessed level of health than expected. Sociodemographic characteristics, life style, self-assessed health and use of the healthcare system were used in the identification of seven homogeneous population clusters. A comprehensive analysis of these clusters suggests health-related prevention and intervention efforts geared towards specific populations.
Justice, N. B.; Sczesnak, A.; Hazen, T. C.; ...
2017-08-04
A central goal of microbial ecology is to identify and quantify the forces that lead to observed population distributions and dynamics. However, these forces, which include environmental selection, dispersal, and organism interactions, are often difficult to assess in natural environments. Here in this paper, we present a method that links microbial community structures with selective and stochastic forces through highly replicated subsampling and enrichment of a single environmental inoculum. Specifically, groundwater from a well-studied natural aquifer was serially diluted and inoculated into nearly 1,000 aerobic and anaerobic nitrate-reducing cultures, and the final community structures were evaluated with 16S rRNA genemore » amplicon sequencing. We analyzed the frequency and abundance of individual operational taxonomic units (OTUs) to understand how probabilistic immigration, relative fitness differences, environmental factors, and organismal interactions contributed to divergent distributions of community structures. We further used a most probable number (MPN) method to estimate the natural condition-dependent cultivable abundance of each of the nearly 400 OTU cultivated in our study and infer the relative fitness of each. Additionally, we infer condition-specific organism interactions and discuss how this high-replicate culturing approach is essential in dissecting the interplay between overlapping ecological forces and taxon-specific attributes that underpin microbial community assembly. IMPORTANCEThrough highly replicated culturing, in which inocula are subsampled from a single environmental sample, we empirically determine how selective forces, interspecific interactions, relative fitness, and probabilistic dispersal shape bacterial communities. These methods offer a novel approach to untangle not only interspecific interactions but also taxon-specific fitness differences that manifest across different cultivation conditions and lead to the selection and enrichment of specific organisms. Additionally, we provide a method for estimating the number of cultivable units of each OTU in the original sample through the MPN approach.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Justice, N. B.; Sczesnak, A.; Hazen, T. C.
A central goal of microbial ecology is to identify and quantify the forces that lead to observed population distributions and dynamics. However, these forces, which include environmental selection, dispersal, and organism interactions, are often difficult to assess in natural environments. Here in this paper, we present a method that links microbial community structures with selective and stochastic forces through highly replicated subsampling and enrichment of a single environmental inoculum. Specifically, groundwater from a well-studied natural aquifer was serially diluted and inoculated into nearly 1,000 aerobic and anaerobic nitrate-reducing cultures, and the final community structures were evaluated with 16S rRNA genemore » amplicon sequencing. We analyzed the frequency and abundance of individual operational taxonomic units (OTUs) to understand how probabilistic immigration, relative fitness differences, environmental factors, and organismal interactions contributed to divergent distributions of community structures. We further used a most probable number (MPN) method to estimate the natural condition-dependent cultivable abundance of each of the nearly 400 OTU cultivated in our study and infer the relative fitness of each. Additionally, we infer condition-specific organism interactions and discuss how this high-replicate culturing approach is essential in dissecting the interplay between overlapping ecological forces and taxon-specific attributes that underpin microbial community assembly. IMPORTANCEThrough highly replicated culturing, in which inocula are subsampled from a single environmental sample, we empirically determine how selective forces, interspecific interactions, relative fitness, and probabilistic dispersal shape bacterial communities. These methods offer a novel approach to untangle not only interspecific interactions but also taxon-specific fitness differences that manifest across different cultivation conditions and lead to the selection and enrichment of specific organisms. Additionally, we provide a method for estimating the number of cultivable units of each OTU in the original sample through the MPN approach.« less
The Hadley circulation: assessing NCEP/NCAR reanalysis and sparse in-situ estimates
NASA Astrophysics Data System (ADS)
Waliser, D. E.; Shi, Zhixiong; Lanzante, J. R.; Oort, A. H.
We present a comparison of the zonal mean meridional circulations derived from monthly in situ data (i.e. radiosondes and ship reports) and from the NCEP/NCAR reanalysis product. To facilitate the interpretation of the results, a third estimate of the mean meridional circulation is produced by subsampling the reanalysis at the locations where radiosonde and surface ship data are available for the in situ calculation. This third estimate, known as the subsampled estimate, is compared to the complete reanalysis estimate to assess biases in conventional, in situ estimates of the Hadley circulation associated with the sparseness of the data sources (i.e., radiosonde network). The subsampled estimate is also compared to the in situ estimate to assess the biases introduced into the reanalysis product by the numerical model, initialization process and/or indirect data sources such as satellite retrievals. The comparisons suggest that a number of qualitative differences between the in situ and reanalysis estimates are mainly associated with the sparse sampling and simplified interpolation schemes associated with in situ estimates. These differences include: (1) a southern Hadley cell that consistently extends up to 200 hPa in the reanalysis, whereas the bulk of the circulation for the in situ and subsampled estimates tends to be confined to the lower half of the troposphere, (2) more well-defined and consistent poleward limits of the Hadley cells in the reanalysis compared to the in-situ and subsampled estimates, and (3) considerably less variability in magnitude and latitudinal extent of the Ferrel cells and southern polar cell exhibited in the reanalysis estimate compared to the in situ and subsampled estimates. Quantitative comparison shows that the subsampled estimate, relative to the reanalysis estimate, produces a stronger northern Hadley cell ( 20%), a weaker southern Hadley cell ( 20-60%), and weaker Ferrel cells in both hemispheres. These differences stem from poorly measured oceanic regions which necessitate significant interpolation over broad regions. Moreover, they help to pinpoint specific shortcomings in the present and previous in situ estimates of the Hadley circulation. Comparisons between the subsampled and in situ estimates suggest that the subsampled estimate produces a slightly stronger Hadley circulation in both hemispheres, with the relative differences in some seasons as large as 20-30%. 6These differences suggest that the mean meridional circulation associated with the NCEP/NCAR reanalysis is more energetic than observations suggest. Examination of ENSO-related changes to the Hadley circulation suggest that the in situ and subsampled estimates significantly overestimate the effects of ENSO on the Hadley circulation due to the reliance on sparsely distributed data. While all three estimates capture the large-scale region of low-level equatorial convergence near the dateline that occurs during El Nino, the in situ and subsampled estimates fail to effectively reproduce the large-scale areas of equatorial mass divergence to the west and east of this convergence area, leading to an overestimate of the effects of ENSO on the zonal mean circulation.
SURMODERR: A MATLAB toolbox for estimation of velocity uncertainties of a non-permanent GPS station
NASA Astrophysics Data System (ADS)
Teza, Giordano; Pesci, Arianna; Casula, Giuseppe
2010-08-01
SURMODERR is a MATLAB toolbox intended for the estimation of reliable velocity uncertainties of a non-permanent GPS station (NPS), i.e. a GPS receiver used in campaign-style measurements. The implemented method is based on the subsampling of daily coordinate time series of one or more continuous GPS stations located inside or close to the area where the NPSs are installed. The continuous time series are subsampled according to real or planned occupation tables and random errors occurring in antenna replacement on different surveys are taken into account. In order to overcome the uncertainty underestimation that typically characterizes short duration GPS time series, statistical analysis of the simulated data is performed to estimate the velocity uncertainties of this real NPS. The basic hypotheses required are: (i) the signal must be a long-term linear trend plus seasonal and colored noise for each coordinate; (ii) the standard data processing should have already been performed to provide daily data series; and (iii) if the method is applied to survey planning, the future behavior should not be significantly different from the past behavior. In order to show the strength of the approach, two case studies with real data are presented and discussed (Central Apennine and Panarea Island, Italy).
Magura, Stephen; Cleland, Charles M; Tonigan, J Scott
2013-05-01
The objective of the study is to determine whether Alcoholics Anonymous (AA) participation leads to reduced drinking and problems related to drinking within Project MATCH (Matching Alcoholism Treatments to Client Heterogeneity), an existing national alcoholism treatment data set. The method used is structural equation modeling of panel data with cross-lagged partial regression coefficients. The main advantage of this technique for the analysis of AA outcomes is that potential reciprocal causation between AA participation and drinking behavior can be explicitly modeled through the specification of finite causal lags. For the outpatient subsample (n = 952), the results strongly support the hypothesis that AA attendance leads to increases in alcohol abstinence and reduces drinking/ problems, whereas a causal effect in the reverse direction is unsupported. For the aftercare subsample (n = 774), the results are not as clear but also suggest that AA attendance leads to better outcomes. Although randomized controlled trials are the surest means of establishing causal relations between interventions and outcomes, such trials are rare in AA research for practical reasons. The current study successfully exploited the multiple data waves in Project MATCH to examine evidence of causality between AA participation and drinking outcomes. The study obtained unique statistical results supporting the effectiveness of AA primarily in the context of primary outpatient treatment for alcoholism.
Subsampling program for the estimation of fish impingement
NASA Astrophysics Data System (ADS)
Beauchamp, John J.; Kumar, K. D.
1984-11-01
Federal regulations require operators of nuclear and coal-fired power-generating stations to estimate the number of fish impinged on intake screens. During winter months, impingement may range into the hundreds of thousands for certain species, making it impossible to count all intake screens completely. We present graphs for determinig the appropriate“optimal” subsample that must be obtained to estimate the total number impinged. Since the number of fish impinged tends to change drastically within a short time period, the subsample size is determined based on the most recent data. This allows for the changing nature of the species-age composition of the impinged fish. These graphs can also be used for subsampling fish catches in an aquatic system when the size of the catch is too large to sample completely.
Obstetric Outcomes of Mothers Previously Exposed to Sexual Violence
Gisladottir, Agnes; Luque-Fernandez, Miguel Angel; Harlow, Bernard L.; Gudmundsdottir, Berglind; Jonsdottir, Eyrun; Bjarnadottir, Ragnheidur I.; Hauksdottir, Arna; Aspelund, Thor; Cnattingius, Sven; Valdimarsdottir, Unnur A.
2016-01-01
Background There is a scarcity of data on the association of sexual violence and women's subsequent obstetric outcomes. Our aim was to investigate whether women exposed to sexual violence as teenagers (12–19 years of age) or adults present with different obstetric outcomes than women with no record of such violence. Methods We linked detailed prospectively collected information on women attending a Rape Trauma Service (RTS) to the Icelandic Medical Birth Registry (IBR). Women who attended the RTS in 1993–2010 and delivered (on average 5.8 years later) at least one singleton infant in Iceland through 2012 formed our exposed cohort (n = 1068). For each exposed woman's delivery, nine deliveries by women with no RTS attendance were randomly selected from the IBR (n = 9126) matched on age, parity, and year and season of delivery. Information on smoking and Body mass index (BMI) was available for a sub-sample (n = 792 exposed and n = 1416 non-exposed women). Poisson regression models were used to estimate Relative Risks (RR) with 95% confidence intervals (CI). Results Compared with non-exposed women, exposed women presented with increased risks of maternal distress during labor and delivery (RR 1.68, 95% CI 1.01–2.79), prolonged first stage of labor (RR 1.40, 95% CI 1.03–1.88), antepartum bleeding (RR 1.95, 95% CI 1.22–3.07) and emergency instrumental delivery (RR 1.16, 95% CI 1.00–1.34). Slightly higher risks were seen for women assaulted as teenagers. Overall, we did not observe differences between the groups regarding the risk of elective cesarean section (RR 0.86, 95% CI 0.61–1.21), except for a reduced risk among those assaulted as teenagers (RR 0.56, 95% CI 0.34–0.93). Adjusting for maternal smoking and BMI in a sub-sample did not substantially affect point estimates. Conclusion Our prospective data suggest that women with a history of sexual assault, particularly as teenagers, are at increased risks of some adverse obstetric outcomes. PMID:27007230
VizieR Online Data Catalog: Search for extraterrestrial intelligence (Isaacson+, 2017)
NASA Astrophysics Data System (ADS)
Isaacson, H.; Siemion, A. P. V.; Marcy, G. W.; Lebofsky, M.; Price, D. C.; MacMahon, D.; Croft, S.; Deboer, D.; Hickish, J.; Werthimer, D.; Sheikh, S.; Hellbourg, G.; Enriquez, J. E.
2017-08-01
The stellar sample is defined by two selection criteria. The first is a volume-limited sample of stars within 5pc of the Sun. The second is a spectral class complete sample consisting of stars across the main sequence and some giant branch stars, all within 50pc. We combined the two sub-samples (5pc and 5-50pc) to produce the final set of 1709 target stars that are listed in Table 1. (1 data file).
A Program of Nutritional Education in Schools Reduced the Prevalence of Iron Deficiency in Students
García-Casal, María Nieves; Landaeta-Jiménez, Maritza; Puche, Rafael; Leets, Irene; Carvajal, Zoila; Patiño, Elijú; Ibarra, Carlos
2011-01-01
The objective was to determine the prevalence of iron, folates and retinol deficiencies in school children and to evaluate the changes after an intervention of nutritional education. The project was developed in 17 schools. The sample included 1,301 children (678 males and 623 females). A subsample of 480 individuals, was randomly selected for drawing blood for biochemical determinations before and after the intervention of nutritional education, which included in each school: written pre and post-intervention tests, 6 workshops, 2 participative talks, 5 game activities, 1 cooking course and 1 recipe contest. Anthropometrical and biochemical determinations included weight, height, body-mass index, nutritional status, hematocrit, serum ferritin, retinol and folate concentrations. There was high prevalence of iron (25%), folates (75%) and vitamin A (43%) deficiencies in school children, with a low consumption of fruit and vegetables, high consumption of soft drinks and snacks and almost no physical activity. The nutritional education intervention produced a significant reduction in iron deficiency prevalence (25 to 14%), and showed no effect on vitamin A and folates deficiencies. There was a slight improvement in nutritional status. This study shows, through biochemical determinations, that nutritional education initiatives and programs have an impact improving nutritional health in school children. PMID:21547083
Bloom, Benjamin; Mehta, Ambereen K.; Clark, Jeanne M.; Gudzune, Kimberly A.
2015-01-01
Objective To determine the reliability of Internet-based information on community-based weight-loss programs and grade their degree of concordance with 2013 American Heart Association, American College of Cardiology, and The Obesity Society weight management guidelines. Methods We conducted an online search for weight-loss programs in the Maryland-Washington, DC-Virginia corridor. We performed content analysis to abstract program components from their websites, and then randomly selected 80 programs for a telephone survey to verify this information. We determined reliability of Internet information in comparison with telephone interview responses. Results Of the 191 programs, we graded 1% as high, 8% as moderate, and 91% as low with respect to guideline concordance based on website content. Fifty-two programs participated in the telephone survey (65% response rate). Program intensity, diet, physical activity, and use of behavioral strategies were underreported on websites as compared to description of these activities during phone interview. Within our subsample, we graded 6% of programs as high based on website information, whereas we graded 19% as high after telephone interview. Conclusions Most weight-loss programs in an urban, mid-Atlantic region do not currently offer guideline-concordant practices and fail to disclose key information online, which may make clinician referrals challenging. PMID:26861769
Enuresis and encopresis in a south Indian population of children.
Hackett, R; Hackett, L; Bhakta, P; Gowers, S
2001-01-01
Though bladder and bowel control are important developmental milestones in all cultures, the prevalence of enuresis and encopresis has rarely been studied in developing countries despite there being factors in these countries that could affect it. This study reports the prevalence and associations of enuresis and encopresis in children in Kerala, India. The parents of 1403 randomly selected 8-12-year-old children were interviewed. The prevalence of enuresis and encopresis was ascertained using Rutter's A2 scale. Subsamples of children underwent psychiatric, physical and psychometric evaluations. Of the children, 18.6% had had an episode of enuresis in the past year and 4.3% in the past week. Four per cent had had an episode of encopresis in the past year. Enuresis was associated with parents' education, physical and psychiatric symptoms in the child, poor academic achievement and lax parental attitudes to toilet training. Encopresis was associated with male sex, physical and psychiatric symptoms, poor academic achievement, early separation and not having a toilet. The prevalence of enuresis compares with western countries, but encopresis is commoner. The associations of enuresis suggested a multifactorial model in which parental competence was prominent. This study de-emphasized the importance of neurodevelopmental factors in enuresis and encopresis in this age group.
Ngai, Fei-Wan; Wai-Chi Chan, Sally; Holroyd, Eleanor
2007-01-01
Women's sense of competence and satisfaction in the maternal role are essential for positive parenting practices and child development. Measures of maternal role competence and satisfaction are limited in the Chinese population. To translate the Parenting Sense of Competence Scale into Chinese (C-PSOC) and to examine the psychometric properties of the C-PSOC. A cross-sectional survey was conducted using a convenience sample of 170 mothers recruited from a postnatal unit. Participants completed the C-PSOC, Rosenberg's Self-Esteem Scale, and the Edinburgh Postnatal Depression Scale. A randomly selected subsample of 57 mothers participated in the 4-week retest. The C-PSOC demonstrated good internal consistency (Cronbach's alpha = .85) and test-retest reliability (intraclass correlation coefficient = .87). Factor analysis supported the two-factor structure reflecting the efficacy and satisfaction dimensions of the original instrument. The scale discriminated between primiparas and multiparas (t = 2.2, p < .05). Significant correlations with Rosenberg's Self-Esteem Scale (r = .60, p < .01) and the Edinburgh Postnatal Depression Scale (r = -.48, p < .01) demonstrated good construct validity. The C-PSOC has satisfactory psychometric properties. It has the potential to be used as a clinical and research instrument for measuring maternal role competence and satisfaction in the Chinese population.
Impact of occupation on stress and anxiety among Indian women.
Patel, Pinal A; Patel, Prerna P; Khadilkar, Anuradha V; Chiplonkar, S A; Patel, Ashish D
2017-03-01
The objectives of this study were to: (1) assess the prevalence of anxiety and stress in Indian women; and (2) evaluate the relationship of occupation to the prevalence of anxiety and stress. A cross-sectional study was performed from January 2013 to June 2014, on women (aged 18-50 years) randomly selected from different occupations in Gujarat, India. Anxiety was evaluated using Spielberg's State and Trait Anxiety Inventory scale and stress was assessed using the International Stress Management Association questionnaire. Serum cortisol concentration was measured in a sub-sample. The association of occupation with stress and anxiety was analyzed by a generalized linear model adjusted for age. Among all participants, 26% were the most prone and 66% were somewhat more prone to stress; 35% of women showed high anxiety levels. Homemakers had 1.2 times higher anxiety and 1.3 times higher stress than working women (p < .05). Prevalence of stress (37%, p < .001) and anxiety (40%, p = .068) were also higher in homemakers compared to working women and students. Serum cortisol levels did not differ significantly (p > .05) by occupation. This study revealed high prevalence rates of stress and anxiety in Indian women. Involvement in activities outside the home may help women to reduce stress.
Gibson, Sarah; Sahanggamu, Daniel; Fatmaningrum, Dewi; Curtis, Val; White, Sian
2017-10-01
To examine levels of bacterial contamination in formula feeding bottles in Sidoarjo, East Java, and to assess the preparation practices that may have been responsible. A cross-sectional study was conducted among 92 randomly selected households with children under the age of two who were bottle-fed formula. In each household, we carried out video observation of mothers/caregivers preparing bottles, and examined samples of formula for coliform bacteria and Escherichia coli (E. coli). In-depth interviews were conducted with a subsample of 20 mothers. A total of 88% of the formula feeds were contaminated with total coliforms at a level >10 MPN/ml, and 45% contained E. coli. These feeds were defined as 'unfit for human consumption'. In the video observations, none of the mothers complied with all five WHO-recommended measures of hygienic formula feed preparation. Only two mothers washed their hands with soap prior to formula preparation. Most mothers also failed to clean or sterilise the bottle and clean the preparation area. In-depth interviews confirmed that such suboptimal hygiene practices were common. The high levels of contamination found highlight that bottles are an important faecal-oral exposure pathway resulting from poor hygiene practices during bottle preparation. © 2017 John Wiley & Sons Ltd.
Arias, Michelle R.; Alpers, Charles N.; Marvin-DiPasquale, Mark C.; Fuller, Christopher C.; Agee, Jennifer L.; Sneed, Michelle; Morita, Andrew Y.; Salas, Antonia
2017-10-31
Cache Creek Settling Basin was constructed in 1937 to trap sediment from Cache Creek before delivery to the Yolo Bypass, a flood conveyance for the Sacramento River system that is tributary to the Sacramento–San Joaquin Delta. Sediment management options being considered by stakeholders in the Cache Creek Settling Basin include sediment excavation; however, that could expose sediments containing elevated mercury concentrations from historical mercury mining in the watershed. In cooperation with the California Department of Water Resources, the U.S. Geological Survey undertook sediment coring campaigns in 2011–12 (1) to describe lateral and vertical distributions of mercury concentrations in deposits of sediment in the Cache Creek Settling Basin and (2) to improve constraint of estimates of the rate of sediment deposition in the basin.Sediment cores were collected in the Cache Creek Settling Basin, Yolo County, California, during October 2011 at 10 locations and during August 2012 at 5 other locations. Total core depths ranged from approximately 4.6 to 13.7 meters (15 to 45 feet), with penetration to about 9.1 meters (30 feet) at most locations. Unsplit cores were logged for two geophysical parameters (gamma bulk density and magnetic susceptibility); then, selected cores were split lengthwise. One half of each core was then photographed and archived, and the other half was subsampled. Initial subsamples from the cores (20-centimeter composite samples from five predetermined depths in each profile) were analyzed for total mercury, methylmercury, total reduced sulfur, iron speciation, organic content (as the percentage of weight loss on ignition), and grain-size distribution. Detailed follow-up subsampling (3-centimeter intervals) was done at six locations along an east-west transect in the southern part of the Cache Creek Settling Basin and at one location in the northern part of the basin for analyses of total mercury; organic content; and cesium-137, which was used for dating. This report documents site characteristics; field and laboratory methods; and results of the analyses of each core section and subsample of these sediment cores, including associated quality-assurance and quality-control data.
Martínez Vega, Mabel V; Sharifzadeh, Sara; Wulfsohn, Dvoralai; Skov, Thomas; Clemmensen, Line Harder; Toldam-Andersen, Torben B
2013-12-01
Visible-near infrared spectroscopy remains a method of increasing interest as a fast alternative for the evaluation of fruit quality. The success of the method is assumed to be achieved by using large sets of samples to produce robust calibration models. In this study we used representative samples of an early and a late season apple cultivar to evaluate model robustness (in terms of prediction ability and error) on the soluble solids content (SSC) and acidity prediction, in the wavelength range 400-1100 nm. A total of 196 middle-early season and 219 late season apples (Malus domestica Borkh.) cvs 'Aroma' and 'Holsteiner Cox' samples were used to construct spectral models for SSC and acidity. Partial least squares (PLS), ridge regression (RR) and elastic net (EN) models were used to build prediction models. Furthermore, we compared three sub-sample arrangements for forming training and test sets ('smooth fractionator', by date of measurement after harvest and random). Using the 'smooth fractionator' sampling method, fewer spectral bands (26) and elastic net resulted in improved performance for SSC models of 'Aroma' apples, with a coefficient of variation CVSSC = 13%. The model showed consistently low errors and bias (PLS/EN: R(2) cal = 0.60/0.60; SEC = 0.88/0.88°Brix; Biascal = 0.00/0.00; R(2) val = 0.33/0.44; SEP = 1.14/1.03; Biasval = 0.04/0.03). However, the prediction acidity and for SSC (CV = 5%) of the late cultivar 'Holsteiner Cox' produced inferior results as compared with 'Aroma'. It was possible to construct local SSC and acidity calibration models for early season apple cultivars with CVs of SSC and acidity around 10%. The overall model performance of these data sets also depend on the proper selection of training and test sets. The 'smooth fractionator' protocol provided an objective method for obtaining training and test sets that capture the existing variability of the fruit samples for construction of visible-NIR prediction models. The implication is that by using such 'efficient' sampling methods for obtaining an initial sample of fruit that represents the variability of the population and for sub-sampling to form training and test sets it should be possible to use relatively small sample sizes to develop spectral predictions of fruit quality. Using feature selection and elastic net appears to improve the SSC model performance in terms of R(2), RMSECV and RMSEP for 'Aroma' apples. © 2013 Society of Chemical Industry.
NASA Astrophysics Data System (ADS)
Zhang, Q.; Ball, W. P.
2016-12-01
Regression-based approaches are often employed to estimate riverine constituent concentrations and fluxes based on typically sparse concentration observations. One such approach is the WRTDS ("Weighted Regressions on Time, Discharge, and Season") method, which has been shown to provide more accurate estimates than prior approaches. Centered on WRTDS, this work was aimed at developing improved models for constituent concentration and flux estimation by accounting for antecedent discharge conditions. Twelve modified models were developed and tested, each of which contains one additional variable to represent antecedent conditions. High-resolution ( daily) data at nine monitoring sites were used to evaluate the relative merits of the models for estimation of six constituents - chloride (Cl), nitrate-plus-nitrite (NOx), total Kjeldahl nitrogen (TKN), total phosphorus (TP), soluble reactive phosphorus (SRP), and suspended sediment (SS). For each site-constituent combination, 30 concentration subsets were generated from the original data through Monte Carlo sub-sampling and then used to evaluate model performance. For the sub-sampling, three sampling strategies were adopted: (A) 1 random sample each month (12/year), (B) 12 random monthly samples plus additional 8 random samples per year (20/year), and (C) 12 regular (non-storm) and 8 storm samples per year (20/year). The modified models show general improvement over the original model under all three sampling strategies. Major improvements were achieved for NOx by the long-term flow-anomaly model and for Cl by the ADF (average discounted flow) model and the short-term flow-anomaly model. Moderate improvements were achieved for SS, TP, and TKN by the ADF model. By contrast, no such achievement was achieved for SRP by any proposed model. In terms of sampling strategy, performance of all models was generally best using strategy C and worst using strategy A, and especially so for SS, TP, and SRP, confirming the value of routinely collecting storm-flow samples. Overall, this work provides a comprehensive set of statistical evidence for supporting the incorporation of antecedent discharge conditions into WRTDS for constituent concentration and flux estimation, thereby combining the advantages of two recent developments in water quality modeling.
Verbowski, Vashti; Talukder, Zaman; Hou, Kroeun; Sok Hoing, Ly; Michaux, Kristina; Anderson, Victoria; Gibson, Rosalind; Li, Kathy H; Lynd, Larry D; McLean, Judy; Green, Tim J; Barr, Susan I
2018-01-05
The Cambodian diet is low in nutrient-dense animal-source foods. Enhanced homestead food production (EHFP) and aquaculture, which increase availability of nutrient-dense foods, are promising interventions to improve dietary intake. This study examined the effect of EHFP with or without aquaculture on dietary intake and prevalence of inadequate intake of select nutrients among women and children living in rural Cambodia, compared to controls. In a registered, cluster randomized controlled trial in Prey Veng, Cambodia, 10 households in each of 90 villages (n = 900) were randomized by village to receive EHFP, EHFP plus aquaculture, or control. After 22-month intervention, 24-hr dietary recalls (24HRs) were collected from mothers aged 18-50 years (n = 429) and their children aged 6 months-7 years (n = 421), reported by their mothers. Usual intake distributions (generated using 24HRs and repeat 24HRs on a subsample) were used to estimate prevalence of inadequate intake. Compared to controls, women in the EHFP group had significantly higher zinc (+1.0 mg/d) and Vitamin A (+139 retinol activity equivalents/d) intakes, and women in the EHFP plus aquaculture group had significantly higher iron (+2.7 mg/d), Vitamin A (+191 retinol activity equivalents/d), and riboflavin (+0.17 mg/d) intakes. Women in the EHFP plus aquaculture group also had significantly lower prevalence of inadequate iron (-7%, at 10% bioavailability), Vitamin A (-19%), and riboflavin (-17%) intakes, compared to controls. No significant differences in intakes or nutrient adequacy were observed among children or between EHFP and EHFP plus aquaculture groups. The biological importance of the small differences in nutrient intakes among women remains to be established. © 2018 John Wiley & Sons Ltd.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stevens, Andrew; Browning, Nigel D.
Traditionally, microscopists have worked with the Nyquist-Shannon theory of sampling, which states that to be able to reconstruct the image fully it needs to be sampled at a rate of at least twice the highest spatial frequency in the image. This sampling rate assumes that the image is sampled at regular intervals and that every pixel contains information that is crucial for the image (it even assumes that noise is important). Images in general, and especially low dose S/TEM images, contain significantly less information than can be encoded by a grid of pixels (which is why image compression works). Mathematicallymore » speaking, the image data has a low dimensional or sparse representation. Through the application of compressive sensing methods [1,2,3] this representation can be found using pre-designed measurements that are usually random for implementation simplicity. These measurements and the compressive sensing reconstruction algorithms have the added benefit of reducing noise. This reconstruction approach can be extended into higher dimensions, whereby the random sampling in each 2-D image can be extended into: a sequence of tomographic projections (i.e. tilt images); a sequence of video frames (i.e. incorporating temporal resolution and dynamics); spectral resolution (i.e. energy filtering an image to see the distribution of elements); and ptychography (i.e. sampling a full diffraction image at each location in a 2-D grid across the sample). This approach has been employed experimentally for materials science samples requiring low-dose imaging [2], and can be readily applied to biological samples. Figure 1 shows the resolution possible in a complex biological system, mouse pancreatic islet beta cells [4], when tomogram slices are reconstructed using subsampling. Reducing the number of pixels (1/6 pix and 1/3*1/3) shows minimal degradation compared to the reconstructions using all pixels (all data and 1/3 tilt). Although subsampling 1/6 of the tilts (1/6 of overall dose) degrades the reconstruction to the point that the cellular structures cannot be identified. Using 1/3 of both the pixels and the tilts provides a high quality image at 1/9 the overall dose even for this most basic and rapid demonstration of the CS methods. Figure 2 demonstrates the theoretical tomogram reconstruction quality (vertical axis) as undersampling (horizontal axis) is increased; we examined subsampling pixels and tilt-angles individually and a combined approach in which both pixels and tilts are sub-sampled. Note that subsampling pixels maintains high quality reconstructions (solid lines). Using the inpainting algorithm to obtain tomograms can automatically reduce the dose applied to the system by an order of magnitude. Perhaps the best way to understand the impact is to consider that by using inpainting (and with minimal hardware changes), a sample that can normally withstand a dose of ~10 e/Å2 can potentially be imaged with an “equivalent quality” to a dose level of 103 e/Å2. To put this in perspective, this is approaching the dose level used for the most advanced images, in terms of spatial resolution, for inorganic systems. While there are issues for biological specimens beyond dose (structural complexity being the most important one), this sampling approach allows the methods that are traditionally used for materials science to be applied to biological systems [5]. References: [1] A Stevens, H Yang, L Carin et al. Microscopy 63(1), (2014), pp. 41. [2] L Kovarik, A Stevens, A Liyu et al. Appl. Phys. Lett. 109, 164102 (2016) [3] A Stevens, L Kovarik, P Abellan et al. Adv. Structural and Chemical Imaging 1(10), (2015), pp. 1. [4] MD Guay, W Czaja, MA Aronova et al. Scientific Reports 6, 27614 (2016) [5] Supported by the Chemical Imaging, Signature Discovery, and Analytics in Motion Initiatives at PNNL. PNNL is operated by Battelle Memorial Inst. for the US DOE; contract DE-AC05-76RL01830.« less
VizieR Online Data Catalog: WISE data for radio-loud AGN complete samples (Gurkan+, 2014)
NASA Astrophysics Data System (ADS)
Gurkan, G.; Hardcastle, M. J.; Jarvis, M. J.
2014-11-01
The 3CRR, 2Jy, 6CE and 7CE samples were chosen for our analysis. We used the revised subsample of the 3CR catalogue of radio sources (Bennett, 1962MNRAS.125...75B), which have flux densities greater than 10.9Jy at 178MHz (Laing, Riley & Longair, 1983MNRAS.204..151L, Cat. J/MNRAS.204.151). There are 172 sources with 0.0029
Lainscsek, Claudia; Weyhenmeyer, Jonathan; Hernandez, Manuel E; Poizner, Howard; Sejnowski, Terrence J
2013-01-01
Time series analysis with delay differential equations (DDEs) reveals non-linear properties of the underlying dynamical system and can serve as a non-linear time-domain classification tool. Here global DDE models were used to analyze short segments of simulated time series from a known dynamical system, the Rössler system, in high noise regimes. In a companion paper, we apply the DDE model developed here to classify short segments of encephalographic (EEG) data recorded from patients with Parkinson's disease and healthy subjects. Nine simulated subjects in each of two distinct classes were generated by varying the bifurcation parameter b and keeping the other two parameters (a and c) of the Rössler system fixed. All choices of b were in the chaotic parameter range. We diluted the simulated data using white noise ranging from 10 to -30 dB signal-to-noise ratios (SNR). Structure selection was supervised by selecting the number of terms, delays, and order of non-linearity of the model DDE model that best linearly separated the two classes of data. The distances d from the linear dividing hyperplane was then used to assess the classification performance by computing the area A' under the ROC curve. The selected model was tested on untrained data using repeated random sub-sampling validation. DDEs were able to accurately distinguish the two dynamical conditions, and moreover, to quantify the changes in the dynamics. There was a significant correlation between the dynamical bifurcation parameter b of the simulated data and the classification parameter d from our analysis. This correlation still held for new simulated subjects with new dynamical parameters selected from each of the two dynamical regimes. Furthermore, the correlation was robust to added noise, being significant even when the noise was greater than the signal. We conclude that DDE models may be used as a generalizable and reliable classification tool for even small segments of noisy data.
Non-Linear Dynamical Classification of Short Time Series of the Rössler System in High Noise Regimes
Lainscsek, Claudia; Weyhenmeyer, Jonathan; Hernandez, Manuel E.; Poizner, Howard; Sejnowski, Terrence J.
2013-01-01
Time series analysis with delay differential equations (DDEs) reveals non-linear properties of the underlying dynamical system and can serve as a non-linear time-domain classification tool. Here global DDE models were used to analyze short segments of simulated time series from a known dynamical system, the Rössler system, in high noise regimes. In a companion paper, we apply the DDE model developed here to classify short segments of encephalographic (EEG) data recorded from patients with Parkinson’s disease and healthy subjects. Nine simulated subjects in each of two distinct classes were generated by varying the bifurcation parameter b and keeping the other two parameters (a and c) of the Rössler system fixed. All choices of b were in the chaotic parameter range. We diluted the simulated data using white noise ranging from 10 to −30 dB signal-to-noise ratios (SNR). Structure selection was supervised by selecting the number of terms, delays, and order of non-linearity of the model DDE model that best linearly separated the two classes of data. The distances d from the linear dividing hyperplane was then used to assess the classification performance by computing the area A′ under the ROC curve. The selected model was tested on untrained data using repeated random sub-sampling validation. DDEs were able to accurately distinguish the two dynamical conditions, and moreover, to quantify the changes in the dynamics. There was a significant correlation between the dynamical bifurcation parameter b of the simulated data and the classification parameter d from our analysis. This correlation still held for new simulated subjects with new dynamical parameters selected from each of the two dynamical regimes. Furthermore, the correlation was robust to added noise, being significant even when the noise was greater than the signal. We conclude that DDE models may be used as a generalizable and reliable classification tool for even small segments of noisy data. PMID:24379798
Hird, Sarah; Kubatko, Laura; Carstens, Bryan
2010-11-01
We describe a method for estimating species trees that relies on replicated subsampling of large data matrices. One application of this method is phylogeographic research, which has long depended on large datasets that sample intensively from the geographic range of the focal species; these datasets allow systematicists to identify cryptic diversity and understand how contemporary and historical landscape forces influence genetic diversity. However, analyzing any large dataset can be computationally difficult, particularly when newly developed methods for species tree estimation are used. Here we explore the use of replicated subsampling, a potential solution to the problem posed by large datasets, with both a simulation study and an empirical analysis. In the simulations, we sample different numbers of alleles and loci, estimate species trees using STEM, and compare the estimated to the actual species tree. Our results indicate that subsampling three alleles per species for eight loci nearly always results in an accurate species tree topology, even in cases where the species tree was characterized by extremely rapid divergence. Even more modest subsampling effort, for example one allele per species and two loci, was more likely than not (>50%) to identify the correct species tree topology, indicating that in nearly all cases, computing the majority-rule consensus tree from replicated subsampling provides a good estimate of topology. These results were supported by estimating the correct species tree topology and reasonable branch lengths for an empirical 10-locus great ape dataset. Copyright © 2010 Elsevier Inc. All rights reserved.
"They're homeless in a home": Retaining homeless-experienced consumers in supported housing.
Gabrielian, Sonya; Hamilton, Alison B; Alexandrino, Adrian; Hellemann, Gerhard; Young, Alexander S
2017-05-01
Permanent, community-based housing with supportive services ("supported housing") has numerous favorable outcomes for homeless-experienced consumers. Little is known, however, about consumers who attain but subsequently lose their supported housing. Using mixed methods, we compared persons who retained their supported housing for at least 1 year ("stayers") with those who lost their supported housing within 1 year of move-in ("exiters"). Among persons housed through the VA Supported Housing (VASH) program at the VA Greater Los Angeles between 2011 and 2012, we queried VA homeless registry data to identify stayers (n = 1,558) and exiters (n = 85). We reviewed the medical records of 85 randomly selected stayers and all 85 exiters to compare demographics, homelessness chronicity, era of service, income, presence or absence of a serious mental illness, and health service utilization. From this subsample, we purposively selected 20 stayers and 20 exiters for semistructured, qualitative interviews, and more detailed medical record review. We also performed qualitative interviews and focus groups with VASH staff/leadership (n = 15). Recursive partitioning identified quantitative variables that best-differentiated stayers from exiters. Thematic analyses were performed on qualitative data. Interrelated factors were associated with exiting supported housing: chronic homelessness; low intrinsic motivation; unmet needs for mental health care, substance abuse treatment, and independent living skills; poor primary care engagement; frequent emergency department use; and recent mental health hospitalizations. These findings suggest the value of clinical interventions that address these factors-for example, motivational interviewing or social skills training-adapted to the setting and context of supported housing. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Factors associated with disordered gambling in Finland
2013-01-01
Background The purpose of this study was to compare the socio-demographic characteristics of non-problem gamblers, problem gamblers and pathological gamblers, to investigate the association between gambling related factors and perceived health and well-being among the three subgroups of gamblers, and to analyse simultaneously socio-demographic characteristics, gambling related factors and perceived health and well-being and the severity of disordered gambling (problem gamblers and pathological gamblers). Methods The data were collected through a nationwide telephone survey in 2011. Participants were selected through a random population sample of 15-74-year-old Finns. From that sample, persons with any past-year gambling involvement (N = 3451) were selected for a subsample for the descriptive and inferential analysis in the present paper. Gambling was assessed using the South Oaks Gambling Screen. Statistical significance was determined by chi-squared tests. The odds ratio and effect size were computed by using multivariate-adjusted multinomial logistic regression analysis. Results The most significant socio-demographic characteristics (male gender, young age, education ≤12 years), gambling related factors (slot machine gambling, internet gambling) and perceived health and well-being (feeling lonely, smoking daily, risky alcohol consumption, mental health problems) explained 22.9 per cent of the variation in the severity of disordered gambling. Conclusion Male gender and loneliness were found to be associated with problem gambling in particular, along with smoking and risky alcohol consumption. Mental health problems and risky alcohol consumption were associated with pathological gambling. These identified associations between disordered gambling, mental health problems and risky alcohol consumption should be taken into consideration when implementing screenings of disordered gambling. PMID:23816162
Choosing health: qualitative evidence from the experiences of personal health budget holders.
Davidson, Jacqueline; Baxter, Kate; Glendinning, Caroline; Irvine, Annie
2013-10-01
Personal health budgets were piloted in the English National Health Service between 2009 and 2012. Semi-structured interviews with a sub-sample of early budget holders aimed to explore their experiences of receiving and using a budget. Over 2000 people from 20 pilot sites were recruited to a multi-method evaluation of the personal health budget pilots. A sub-sample of 58 people was selected for qualitative interviews three months after the offer of a budget; 52 were re-interviewed six months later. The purposively selected sample reflected a range of health conditions, locality, age and gender. Personal health budgets were reported to have positive impacts on health, health care and relatives/family. Benefits often extended beyond the condition for which the budget had been awarded. However, interviewees rarely knew the level of their budget; some reported difficulty in agreeing acceptable uses for their budget; and delays could occur in procuring chosen services or equipment. Patients' experiences offer valuable insights for the roll-out of personal health budgets beyond the pilot phase. Flexibility in how budgets are used may allow maximum benefits to be derived. Clear information about what budgets can and cannot be used for, with suggestions offered, will be useful. People with newly diagnosed or recent sudden onset conditions may need more help to plan their support, but all budget holders are likely to benefit from regular contact with staff for reassurance and continued motivation.
Lyα-Lyman continuum connection in 3.5 ≤ z ≤ 4.3 star-forming galaxies from the VUDS survey
NASA Astrophysics Data System (ADS)
Marchi, F.; Pentericci, L.; Guaita, L.; Schaerer, D.; Verhamme, A.; Castellano, M.; Ribeiro, B.; Garilli, B.; Fèvre, O. Le; Amorin, R.; Bardelli, S.; Cassata, P.; Durkalec, A.; Grazian, A.; Hathi, N. P.; Lemaux, B. C.; Maccagni, D.; Vanzella, E.; Zucca, E.
2018-06-01
Context. To identify the galaxies responsible for the reionization of the Universe, we must rely on the investigation of the Lyman continuum (LyC) properties of z ≲ 5 star-forming galaxies, where we can still directly observe their ionizing radiation. Aims: The aim of this work is to explore the correlation between the LyC emission and some of the proposed indirect indicators of LyC radiation at z 4 such as a bright Lyα emission and a compact UV continuum size. Methods: We selected a sample of 201 star-forming galaxies from the Vimos Ultra Deep Survey (VUDS) at 3.5 ≤ z ≤ 4.3 in the COSMOS, ECDFS, and VVDS-2h fields, including only those with reliable spectroscopic redshifts, a clean spectrum in the LyC range and clearly not contaminated by bright nearby sources in the same slit. For all galaxies we measured the Lyα EW, the Lyα velocity shift with respect to the systemic redshift, the Lyα spatial extension and the UV continuum effective radius. We then selected different sub-samples according to the properties predicted to be good LyC emission indicators: in particular we created sub-samples of galaxies with EW(Lyα) ≥ 70 Å, Lyαext ≤ 5.7 kpc, rUV ≤ 0.30 kpc and |ΔvLyα|≤ 200 km s-1. We stacked all the galaxies in each sub-sample and measured the flux density ratio (fλ(895)/fλ(1470)), that we considered to be a proxy for LyC emission. We then compared these ratios to those obtained for the complementary samples. Finally, to estimate the statistical contamination from lower redshift inter-lopers in our samples, we performed dedicated Monte Carlo simulations using an ultradeep U-band image of the ECDFS field. Results: We find that the stacks of galaxies which are UV compact (rUV ≤ 0.30 kpc) and have bright Lyα emission (EW(Lyα) ≥ 70 Å), have much higher LyC fluxes compared to the rest of the galaxy population. These parameters appear to be good indicators of LyC radiation in agreement with theoretical studies and previous observational works. In addition we find that galaxies with a low Lyα spatial extent (Lyαext ≤ 5.7 kpc) have higher LyC flux compared to the rest of the population. Such a correlation had never been analysed before and seems even stronger than the correlation with high EW(Lyα) and small rUV. These results assume that the stacks from all sub-samples present the same statistical contamination from lower redshift interlopers. If we subtract a statistical contamination from low redshift interlopers obtained with the simulations from the flux density ratios (fλ(895)/fλ(1470)) of the significant sub-samples we find that these samples contain real LyC leaking flux with a very high probability, although the true average escape fractions are very uncertain. Conclusions: Our work indicates that galaxies with very high EW(Lyα), small Ly αext and small rUV are very likely the best candidates to show Lyman continuum radiation at z 4 and could therefore be the galaxies that have contributed most to reionisation. Based on data obtained with the European Southern Observatory Very Large Telescope, Paranal, Chile, under Large Program 185.A-0791.
Jowsey, Tanisha; McRae, Ian S; Valderas, Jose M; Dugdale, Paul; Phillips, Rebecca; Bunton, Robin; Gillespie, James; Banfield, Michelle; Jones, Lesley; Kljakovic, Marjan; Yen, Laurann
2013-01-01
Most Western health systems remain single illness orientated despite the growing prevalence of multi-morbidity. Identifying how much time people with multiple chronic conditions spend managing their health will help policy makers and health service providers make decisions about areas of patient need for support. This article presents findings from an Australian study concerning the time spent on health related activity by older adults (aged 50 years and over), most of whom had multiple chronic conditions. A recall questionnaire was developed, piloted, and adjusted. Sampling was undertaken through three bodies; the Lung Foundation Australia (COPD sub-sample), National Diabetes Services Scheme (Diabetes sub-sample) and National Seniors Australia (Seniors sub-sample). Questionnaires were mailed out during 2011 to 10,600 older adults living in Australia. 2540 survey responses were received and analysed. Descriptive analyses were completed to obtain median values for the hours spent on each activity per month. The mean number of chronic conditions was 3.7 in the COPD sub-sample, 3.4 in the Diabetes sub-sample and 2.0 in the NSA sub-sample. The study identified a clear trend of increased time use associated with increased number of chronic conditions. Median monthly time use was 5-16 hours per month overall for our three sub-samples. For respondents in the top decile with five or more chronic conditions the median time use was equivalent to two to three hours per day, and if exercise is included in the calculations, respondents spent from between five and eight hours per day: an amount similar to full-time work. Multi-morbidity imposes considerable time burdens on patients. Ageing is associated with increasing rates of multi-morbidity. Many older adults are facing high demands on their time to manage their health in the face of decreasing energy and mobility. Their time use must be considered in health service delivery and health system reform.
Griffin, Dale W.
2011-01-01
Epifluorescent microscopy and quantitative polymerase chain reaction (qPCR) were utilized to determine the presence, concentration and identification of bacteria, and more specifically sulfate reducing bacteria (SRB) in subsamples of Chinese and North American wallboard, and wallboard-mine rock. Bacteria were visible in most subsamples, which included wallboard-lining paper from each side of the wallboard, wallboard filler, wallboard tape and fragments of mined wallboard rock via microscopy. Observed bacteria occurred as single or small clusters of cells and no mass aggregates indicating colonization were noted. Universal 16S qPCR was utilized to directly examine samples and detected bacteria at concentrations ranging from 1.4 x 103 to 6.4 x 104 genomic equivalents per mm2 of paper or per gram of wallboard filler or mined rock, in 12 of 41 subsamples. Subsamples were incubated in sulfate reducing broth for ~30 to 60 days (enrichment assay) and then analyzed by universal 16S and SRB qPCR. Enrichment universal 16S qPCR detected bacteria in 32 of 41 subsamples at concentrations ranging from 1.5 x 104 to 4.2 x 107 genomic equivalents per ml of culture broth. Evaluation of enriched subsamples by SRB qPCR demonstrated that SRB were not detectable in most of the samples and if they were detected, detection was not reproducible (an indication of low concentrations, if present). Enrichment universal 16S and SRB qPCR demonstrated that viable bacteria were present in subsamples (as expected given exposure of the samples following manufacture, transport and use) but that SRB were either not present or present at very low numbers. Further, no differences in trends were noted between the various Chinese and North American wallboard samples. In all, the microscopy and qPCR data indicated that the suspected ‘sulfur emissions’ emanating from suspect wallboard samples is not due to microbial activity.
Locomotor disability: meaning, causes and effects of interventions.
Ebrahim, Shah; Adamson, Joy; Ayis, Salma; Beswick, Andrew; Gooberman-Hill, Rachael
2008-10-01
This paper provides a synopsis of a long-term programme of MRC-funded work on locomotor disability in older people. Specifically it describes the meaning and experience of disability, examines the risk factors for disability and systematically reviews the evidence from randomized trials of complex interventions for disability. We undertook a national prospective study of a representative sample of 999 people aged 65 years or more plus in-depth interviews with a small subsample and a selected sample obtained from hospital sources. Secondary analysis of several large prospective studies was carried out and a systematic review and meta-analysis of published randomized controlled trials of the effects of complex interventions for disability. Very few participants subscribed to the constructs of longstanding illness, disability or infirmity that surveys often use. A wide range of social and psychological factors, independently of chronic diseases, were strongly associated with disability. People with greater functional reserve capacity and those with greater self-efficacy were generally less likely to suffer from catastrophic decline in ability and had better quality of life in the face of disability. In reviewing 89 trials (over 97,000 participants) of complex interventions for disability, evidence of benefits was found although no relationship with intensity of intervention was apparent. Our findings on the meaning and experience of disability suggest the need for modifications to routinely used survey questions and for different ways of understanding the need for and receipt of care among older people with disabilities. The diverse risk factors for disability suggest that novel approaches across social, psychological as well as more traditional rehabilitation and behavioural risk factor modification would be worth exploring. Complex interventions appeared to help older people to live independently and limit functional decline irrespective of age and health status.
Azzolina, Nicholas A; Small, Mitchell J; Nakles, David V; Glazewski, Kyle A; Peck, Wesley D; Gorecki, Charles D; Bromhal, Grant S; Dilmore, Robert M
2015-01-20
This work uses probabilistic methods to simulate a hypothetical geologic CO2 storage site in a depleted oil and gas field, where the large number of legacy wells would make it cost-prohibitive to sample all wells for all measurements as part of the postinjection site care. Deep well leakage potential scores were assigned to the wells using a random subsample of 100 wells from a detailed study of 826 legacy wells that penetrate the basal Cambrian formation on the U.S. side of the U.S./Canadian border. Analytical solutions and Monte Carlo simulations were used to quantify the statistical power of selecting a leaking well. Power curves were developed as a function of (1) the number of leaking wells within the Area of Review; (2) the sampling design (random or judgmental, choosing first the wells with the highest deep leakage potential scores); (3) the number of wells included in the monitoring sampling plan; and (4) the relationship between a well’s leakage potential score and its relative probability of leakage. Cases where the deep well leakage potential scores are fully or partially informative of the relative leakage probability are compared to a noninformative base case in which leakage is equiprobable across all wells in the Area of Review. The results show that accurate prior knowledge about the probability of well leakage adds measurable value to the ability to detect a leaking well during the monitoring program, and that the loss in detection ability due to imperfect knowledge of the leakage probability can be quantified. This work underscores the importance of a data-driven, risk-based monitoring program that incorporates uncertainty quantification into long-term monitoring sampling plans at geologic CO2 storage sites.
Rodriguez, Violeta J; Peltzer, Karl; Matseke, Gladys; Weiss, Stephen M; Shine, Agnes; Jones, Deborah L
2018-05-23
In rural South Africa, pregnant HIV-infected women report high rates of psychological (55%) and physical (20%) intimate partner violence (IPV). IPV increases the risk of infant developmental delays. Such delays may have negative socioemotional and cognitive outcomes throughout the lifespan. This paper assesses the relationship between IPV and infant development in rural South Africa. The present investigation was a cross-sectional add-on follow-up designed retrospectively. A randomly selected sub-sample of mothers from the main randomized controlled trial (n = 72) were asked to participate with their infants at 12 months of age; all women invited agreed to participate. Women were 18.35 ± 5.47 weeks pregnant; demographics, HIV disclosure status, and pre- and postnatal IPV measured via the Conflict Tactics Scale during pregnancy at baseline and 12 months post-partum were assessed. Infant HIV serostatus and developmental functioning at 12 months of age were assessed. Women were a mean age of 29 ± 2 years. One third had completed at least 12 years of education and had a monthly income of ~ US$76. At 12 months post-partum, 6% of infants tested HIV seropositive. Postnatal physical IPV was associated with delays in cognitive and receptive language development p < 0.05, but only in unadjusted analyses. This study identified an association between early IPV exposure and infant cognitive and receptive communication delays. Given the small sample size, findings support replication. Longitudinal studies are needed to confirm temporal order and identify appropriate timing for interventions in HIV-exposed infants.
Cadenas-Sánchez, Cristina; Mora-González, José; Migueles, Jairo H; Martín-Matillas, Miguel; Gómez-Vida, José; Escolano-Margarit, María Victoria; Maldonado, José; Enriquez, Gala María; Pastor-Villaescusa, Belén; de Teresa, Carlos; Navarrete, Socorro; Lozano, Rosa María; de Dios Beas-Jiménez, Juan; Estévez-López, Fernando; Mena-Molina, Alejandra; Heras, María José; Chillón, Palma; Campoy, Cristina; Muñoz-Hernández, Victoria; Martínez-Ávila, Wendy Daniela; Merchan, María Elisa; Perales, José C; Gil, Ángel; Verdejo-García, Antonio; Aguilera, Concepción M; Ruiz, Jonatan R; Labayen, Idoia; Catena, Andrés; Ortega, Francisco B
2016-03-01
The new and recent advances in neuroelectric and neuroimaging technologies provide a new era for further exploring and understanding how brain and cognition function can be stimulated by environmental factors, such as exercise, and particularly to study whether physical exercise influences brain development in early ages. The present study, namely the ActiveBrains project, aims to examine the effects of a physical exercise programme on brain and cognition, as well as on selected physical and mental health outcomes in overweight/obese children. A total of 100 participants aged 8 to 11 years are randomized into an exercise group (N=50) or a control group (N=50). The intervention lasts 20-weeks, with 3-5 sessions per week of 90 min each, and is mainly focused on high-intensity aerobic exercise yet also includes muscle-strengthening exercises. The extent to what the intervention effect remains 8-months after the exercise programme finishes is also studied in a subsample. Brain structure and function and cognitive performance are assessed using structural and functional magnetic resonance imaging and electroencephalographic recordings. Secondary outcomes include physical health outcomes (e.g. physical fitness, body fatness, bone mass and lipid-metabolic factors) and mental health outcomes (e.g. chronic stress indicators and overall behavioural and personality measurements such as anxiety or depression). This project will substantially contribute to the existing knowledge and will have an impact on societies, since early stimulation of brain development might have long lasting consequences on cognitive performance, academic achievement and in the prevention of behavioural problems and the promotion of psychological adjustment and mental health. Clinical trials. Gov identifier: NCT02295072. Copyright © 2016 Elsevier Inc. All rights reserved.
Implications of Satellite Swath Width on Global Aerosol Optical Thickness Statistics
NASA Technical Reports Server (NTRS)
Colarco, Peter; Kahn, Ralph; Remer, Lorraine; Levy, Robert; Welton, Ellsworth
2012-01-01
We assess the impact of swath width on the statistics of aerosol optical thickness (AOT) retrieved by satellite as inferred from observations made by the Moderate Resolution Imaging Spectroradiometer (MODIS). We sub-sample the year 2009 MODIS data from both the Terra and Aqua spacecraft along several candidate swaths of various widths. We find that due to spatial sampling there is an uncertainty of approximately 0.01 in the global, annual mean AOT. The sub-sampled monthly mean gridded AOT are within +/- 0.01 of the full swath AOT about 20% of the time for the narrow swath sub-samples, about 30% of the time for the moderate width sub-samples, and about 45% of the time for the widest swath considered. These results suggest that future aerosol satellite missions with only a narrow swath view may not sample the true AOT distribution sufficiently to reduce significantly the uncertainty in aerosol direct forcing of climate.
NASA Astrophysics Data System (ADS)
Önal Taş, Ö.; Bilir, S.; Plevne, O.
2018-02-01
We aim to probe the dynamic structure of the extended Solar neighborhood by calculating the radial metallicity gradients from orbit properties, which are obtained for axisymmetric and non-axisymmetric potential models, of red clump (RC) stars selected from the RAdial Velocity Experiment's Fourth Data Release. Distances are obtained by assuming a single absolute magnitude value in near-infrared, i.e. M_{Ks}=-1.54±0.04 mag, for each RC star. Stellar orbit parameters are calculated by using the potential functions: (i) for the MWPotential2014 potential, (ii) for the same potential with perturbation functions of the Galactic bar and transient spiral arms. The stellar age is calculated with a method based on Bayesian statistics. The radial metallicity gradients are evaluated based on the maximum vertical distance (z_{max}) from the Galactic plane and the planar eccentricity (ep) of RC stars for both of the potential models. The largest radial metallicity gradient in the 0< z_{max} ≤0.5 kpc distance interval is -0.065±0.005 dex kpc^{-1} for a subsample with ep≤0.1, while the lowest value is -0.014±0.006 dex kpc^{-1} for the subsample with ep≤0.5. We find that at z_{max}>1 kpc, the radial metallicity gradients have zero or positive values and they do not depend on ep subsamples. There is a large radial metallicity gradient for thin disc, but no radial gradient found for thick disc. Moreover, the largest radial metallicity gradients are obtained where the outer Lindblad resonance region is effective. We claim that this apparent change in radial metallicity gradients in the thin disc is a result of orbital perturbation originating from the existing resonance regions.
Cluster candidates around low-power radio galaxies at z ∼ 1-2 in cosmos
DOE Office of Scientific and Technical Information (OSTI.GOV)
Castignani, G.; Celotti, A.; De Zotti, G.
2014-09-10
We search for high-redshift (z ∼1-2) galaxy clusters using low power radio galaxies (FR I) as beacons and our newly developed Poisson probability method based on photometric redshift information and galaxy number counts. We use a sample of 32 FR Is within the Cosmic Evolution Survey (COSMOS) field from the Chiaberge et al. catalog. We derive a reliable subsample of 21 bona fide low luminosity radio galaxies (LLRGs) and a subsample of 11 high luminosity radio galaxies (HLRGs), on the basis of photometric redshift information and NRAO VLA Sky Survey radio fluxes. The LLRGs are selected to have 1.4 GHzmore » rest frame luminosities lower than the fiducial FR I/FR II divide. This also allows us to estimate the comoving space density of sources with L {sub 1.4} ≅ 10{sup 32.3} erg s{sup –1} Hz{sup –1} at z ≅ 1.1, which strengthens the case for a strong cosmological evolution of these sources. In the fields of the LLRGs and HLRGs we find evidence that 14 and 8 of them reside in rich groups or galaxy clusters, respectively. Thus, overdensities are found around ∼70% of the FR Is, independently of the considered subsample. This rate is in agreement with the fraction found for low redshift FR Is and it is significantly higher than that for FR IIs at all redshifts. Although our method is primarily introduced for the COSMOS survey, it may be applied to both present and future wide field surveys such as Sloan Digital Sky Survey Stripe 82, LSST, and Euclid. Furthermore, cluster candidates found with our method are excellent targets for next generation space telescopes such as James Webb Space Telescope.« less
Sibai, Abla M; Ghandour, Lilian A; Chaaban, Rawan; Mokdad, Ali H
2016-05-31
Given the worldwide proliferation of cellphones, this paper examines their potential use for the surveillance of non-communicable disease (NCD) risk factors in a Middle Eastern country. Data were derived from a national household survey of 2,656 adults (aged 18 years or older) in Lebanon in 2009. Responses to questions on phone ownership yielded two subsamples, the 'cell phone sample' (n = 1,404) and the 'any phone sample' (n = 2,158). Prevalence estimates of various socio-demographics and 11 key NCD risk factors and comorbidities were compared between each subsample and the overall household sample. Adjusting for baseline age and sex distribution, no differences were observed for all NCD indicators when comparing either of subsamples to the overall household sample, except for binge drinking [(OR = 1.55, 95 % CI: 1.33-1.81) and (OR = 1.48, 95 % CI: 1.18-1.85) for 'cell phone subsample' and 'any phone subsample', respectively] and self-rated health (OR = 1.23, 95 % CI: 1.10-1.36) and (OR = 1.16, 95 % CI: 1.02-1.32), respectively). Differences in the odds of hyperlipidemia (OR = 1.27, 95 % CI: 1.06-1.51) was also found in the subsample of 'any phone' carriers. Multi-mode telephone surveillance techniques provide viable alternative to face-to-face surveys in developing countries. Cell phones may also be useful for personalized public health and medical care interventions in young populations.
NASA Technical Reports Server (NTRS)
Holdaway, Daniel; Yang, Yuekui
2016-01-01
This is the second part of a study on how temporal sampling frequency affects satellite retrievals in support of the Deep Space Climate Observatory (DSCOVR) mission. Continuing from Part 1, which looked at Earth's radiation budget, this paper presents the effect of sampling frequency on DSCOVR-derived cloud fraction. The output from NASA's Goddard Earth Observing System version 5 (GEOS-5) Nature Run is used as the "truth". The effect of temporal resolution on potential DSCOVR observations is assessed by subsampling the full Nature Run data. A set of metrics, including uncertainty and absolute error in the subsampled time series, correlation between the original and the subsamples, and Fourier analysis have been used for this study. Results show that, for a given sampling frequency, the uncertainties in the annual mean cloud fraction of the sunlit half of the Earth are larger over land than over ocean. Analysis of correlation coefficients between the subsamples and the original time series demonstrates that even though sampling at certain longer time intervals may not increase the uncertainty in the mean, the subsampled time series is further and further away from the "truth" as the sampling interval becomes larger and larger. Fourier analysis shows that the simulated DSCOVR cloud fraction has underlying periodical features at certain time intervals, such as 8, 12, and 24 h. If the data is subsampled at these frequencies, the uncertainties in the mean cloud fraction are higher. These results provide helpful insights for the DSCOVR temporal sampling strategy.
Sattler, Tine; Sekulic, Damir; Spasic, Miodrag; Osmankac, Nedzad; Vicente João, Paulo; Dervisevic, Edvin; Hadzic, Vedran
2016-01-01
Previous investigations noted potential importance of isokinetic strength in rapid muscular performances, such as jumping. This study aimed to identify the influence of isokinetic-knee-strength on specific jumping performance in volleyball. The secondary aim of the study was to evaluate reliability and validity of the two volleyball-specific jumping tests. The sample comprised 67 female (21.96±3.79 years; 68.26±8.52 kg; 174.43±6.85 cm) and 99 male (23.62±5.27 years; 84.83±10.37 kg; 189.01±7.21 cm) high- volleyball players who competed in 1st and 2nd National Division. Subjects were randomly divided into validation (N.=55 and 33 for males and females, respectively) and cross-validation subsamples (N.=54 and 34 for males and females, respectively). Set of predictors included isokinetic tests, to evaluate the eccentric and concentric strength capacities of the knee extensors, and flexors for dominant and non-dominant leg. The main outcome measure for the isokinetic testing was peak torque (PT) which was later normalized for body mass and expressed as PT/Kg. Block-jump and spike-jump performances were measured over three trials, and observed as criteria. Forward stepwise multiple regressions were calculated for validation subsamples and then cross-validated. Cross validation included correlations between and t-test differences between observed and predicted scores; and Bland Altman graphics. Jumping tests were found to be reliable (spike jump: ICC of 0.79 and 0.86; block-jump: ICC of 0.86 and 0.90; for males and females, respectively), and their validity was confirmed by significant t-test differences between 1st vs. 2nd division players. Isokinetic variables were found to be significant predictors of jumping performance in females, but not among males. In females, the isokinetic-knee measures were shown to be stronger and more valid predictors of the block-jump (42% and 64% of the explained variance for validation and cross-validation subsample, respectively) than that of the spike-jump (39% and 34% of the explained variance for validation and cross-validation subsample, respectively). Differences between prediction models calculated for males and females are mostly explained by gender-specific biomechanics of jumping. Study defined importance of knee-isokinetic-strength in volleyball jumping performance in female athletes. Further studies should evaluate association between ankle-isokinetic-strength and volleyball-specific jumping performances. Results reinforce the need for the cross-validation of the prediction-models in sport and exercise sciences.
Statistical Application and Cost Saving in a Dental Survey.
Chyou, Po-Huang; Schroeder, Dixie; Schwei, Kelsey; Acharya, Amit
2017-06-01
To effectively achieve a robust survey response rate in a timely manner, an alternative approach to survey distribution, informed by statistical modeling, was applied to efficiently and cost-effectively achieve the targeted rate of return. A prospective environmental scan surveying adoption of health information technology utilization within their practices was undertaken in a national pool of dental professionals (N=8000) using an alternative method of sampling. The piloted approach to rate of cohort sampling targeted a response rate of 400 completed surveys from among randomly targeted eligible providers who were contacted using replicated subsampling leveraging mailed surveys. Two replicated subsample mailings (n=1000 surveys/mailings) were undertaken to project the true response rate and estimate the total number of surveys required to achieve the final target. Cost effectiveness and non-response bias analyses were performed. The final mailing required approximately 24% fewer mailings compared to targeting of the entire cohort, with a final survey capture exceeding the expected target. An estimated $5000 in cost savings was projected by applying the alternative approach. Non-response analyses found no evidence of bias relative to demographics, practice demographics, or topically-related survey questions. The outcome of this pilot study suggests that this approach to survey studies will accomplish targeted enrollment in a cost effective manner. Future studies are needed to validate this approach in the context of other survey studies. © 2017 Marshfield Clinic.
Development and evaluation of the Internalized Racism in Asian Americans Scale (IRAAS).
Choi, Andrew Young; Israel, Tania; Maeda, Hotaka
2017-01-01
This article presents the development and psychometric evaluation of the Internalized Racism in Asian Americans Scale (IRAAS), which was designed to measure the degree to which Asian Americans internalized hostile attitudes and negative messages targeted toward their racial identity. Items were developed on basis of prior literature, vetted through expert feedback and cognitive interviews, and administered to 655 Asian American participants through Amazon Mechanical Turk. Exploratory factor analysis with a random subsample (n = 324) yielded a psychometrically robust preliminary measurement model consisting of 3 factors: Self-Negativity, Weakness Stereotypes, and Appearance Bias. Confirmatory factor analysis with a separate subsample (n = 331) indicated that the proposed correlated factors model was strongly consistent with the observed data. Factor determinacies were high and demonstrated that the specified items adequately measured their intended factors. Bifactor modeling further indicated that this multidimensionality could be univocally represented for the purpose of measurement, including the use of a mean total score representing a single continuum of internalized racism on which individuals vary. The IRAAS statistically predicted depressive symptoms, and demonstrated statistically significant correlations in theoretically expected directions with four dimensions of collective self-esteem. These results provide initial validity evidence supporting the use of the IRAAS to measure aspects of internalized racism in this population. Limitations and research implications are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Statistical Application and Cost Saving in a Dental Survey
Chyou, Po-Huang; Schroeder, Dixie; Schwei, Kelsey; Acharya, Amit
2017-01-01
Objective To effectively achieve a robust survey response rate in a timely manner, an alternative approach to survey distribution, informed by statistical modeling, was applied to efficiently and cost-effectively achieve the targeted rate of return. Design A prospective environmental scan surveying adoption of health information technology utilization within their practices was undertaken in a national pool of dental professionals (N=8000) using an alternative method of sampling. The piloted approach to rate of cohort sampling targeted a response rate of 400 completed surveys from among randomly targeted eligible providers who were contacted using replicated subsampling leveraging mailed surveys. Methods Two replicated subsample mailings (n=1000 surveys/mailings) were undertaken to project the true response rate and estimate the total number of surveys required to achieve the final target. Cost effectiveness and non-response bias analyses were performed. Results The final mailing required approximately 24% fewer mailings compared to targeting of the entire cohort, with a final survey capture exceeding the expected target. An estimated $5000 in cost savings was projected by applying the alternative approach. Non-response analyses found no evidence of bias relative to demographics, practice demographics, or topically-related survey questions. Conclusion The outcome of this pilot study suggests that this approach to survey studies will accomplish targeted enrollment in a cost effective manner. Future studies are needed to validate this approach in the context of other survey studies. PMID:28373286
Spoth, Richard L.; Randall, G. Kevin; Trudeau, Linda; Shin, Chungyeol; Redmond, Cleve
2008-01-01
This article reports adolescent substance use outcomes of universal family and school preventive interventions 5½ years past baseline. Participants were 1677 7th grade students from schools (N = 36) randomly assigned to the school-based Life Skills Training plus the Strengthening Families Program: For Parents and Youth 10–14 (LST + SFP 10–14), LST-alone, or a control condition. Self-reports were collected at baseline, 6 months later following the interventions, then yearly through the 12th grade. Measures included initiation—alcohol, cigarette, marijuana, and drunkenness, along with a Substance Initiation Index (SII)—and measures of more serious use—frequency of alcohol, cigarette, and marijuana use, drunkenness frequency, monthly poly-substance use, and advanced poly-substance use. Analyses ruled out differential attrition. For all substance initiation outcomes, one or both intervention groups showed significant, positive point-in-time differences at 12th grade and/or significant growth trajectory outcomes when compared with the control group. Although no main effects for the more serious substance use outcomes were observed, a higher-risk subsample demonstrated significant, positive 12th grade point-in-time and/or growth trajectory outcomes for one or both intervention groups on all measures. The observed pattern of results likely reflects a combination of predispositions of the higher-risk subsample, the timing of the interventions, and baseline differences between experimental conditions favoring the control group. PMID:18434045
Thorndike, Frances P.; Ritterband, Lee M.; Gonder-Frederick, Linda A.; Lord, Holly R.; Ingersoll, Karen S.; Morin, Charles M.
2014-01-01
Objective Insomnia is frequently comorbid with other medical and psychological disorders. This secondary data analysis investigated whether an Internet-delivered cognitive behavioral therapy for insomnia (CBT-I) intervention could also reduce comorbid psychological and fatigue symptoms. Method Data from a pilot randomized controlled trial (RCT) testing the efficacy of Internet-delivered CBT-I relative to a waitlist control was used to examine changes in symptoms of depression, anxiety, mental health quality of life (QOL), and fatigue. Results Group by time interactions from repeated measures analyses revealed significant post intervention improvements in Internet participants (n = 22) relative to control participants (n = 22) on all psychological symptoms, mental health QOL, and fatigue. A small post hoc subsample of Internet participants with mild or moderate depression also showed large effect size changes in these constructs (depression, anxiety, mental health QOL, and fatigue). Conclusion Internet-delivered CBT-I appears to not only improve sleep but also reduce comorbid psychological and fatigue symptoms. PMID:24014057
Thorndike, Frances P; Ritterband, Lee M; Gonder-Frederick, Linda A; Lord, Holly R; Ingersoll, Karen S; Morin, Charles M
2013-10-01
Insomnia is frequently comorbid with other medical and psychological disorders. This secondary data analysis investigated whether an Internet-delivered cognitive behavioral therapy for insomnia (CBT-I) intervention could also reduce comorbid psychological and fatigue symptoms. Data from a pilot randomized controlled trial (RCT) testing the efficacy of Internet-delivered CBT-I relative to a waitlist control was used to examine changes in symptoms of depression, anxiety, mental health quality of life (QOL), and fatigue. Group by time interactions from repeated measures analyses revealed significant post intervention improvements in Internet participants (n = 22) relative to control participants (n = 22) on all psychological symptoms, mental health QOL, and fatigue. A small post hoc subsample of Internet participants with mild or moderate depression also showed large effect size changes in these constructs (depression, anxiety, mental health QOL, and fatigue). Internet-delivered CBT-I appears to not only improve sleep but also reduce comorbid psychological and fatigue symptoms. © 2013 Wiley Periodicals, Inc.
Application of the Bootstrap Statistical Method in Deriving Vibroacoustic Specifications
NASA Technical Reports Server (NTRS)
Hughes, William O.; Paez, Thomas L.
2006-01-01
This paper discusses the Bootstrap Method for specification of vibroacoustic test specifications. Vibroacoustic test specifications are necessary to properly accept or qualify a spacecraft and its components for the expected acoustic, random vibration and shock environments seen on an expendable launch vehicle. Traditionally, NASA and the U.S. Air Force have employed methods of Normal Tolerance Limits to derive these test levels based upon the amount of data available, and the probability and confidence levels desired. The Normal Tolerance Limit method contains inherent assumptions about the distribution of the data. The Bootstrap is a distribution-free statistical subsampling method which uses the measured data themselves to establish estimates of statistical measures of random sources. This is achieved through the computation of large numbers of Bootstrap replicates of a data measure of interest and the use of these replicates to derive test levels consistent with the probability and confidence desired. The comparison of the results of these two methods is illustrated via an example utilizing actual spacecraft vibroacoustic data.
Vitamin A deficiency and xerophthalmia in western Yemen.
Rosen, D S; al Sharif, Z; Bashir, M; al Shabooti, A; Pizzarello, L D
1996-01-01
To determine the prevalence of xerophthalmia and the extent of vitamin A deficiency in western Yemen. A stratified cluster sample of children aged 1-5 years with clinical examination for signs of xerophthalmia as well as blood serum survey. The 18 districts of western Yemen, of which 10 clusters were chosen at random. All children aged 1-5 years resident in the cluster sites (n = 2438). Clinical signs of xerophthalmia, a history of night blindness, serum retinol levels in a random sample of clinically normal children (n =338) in addition to all children with xerophthalmia. Night blindness was found in 0.5% of the children, Bitot's spots in 1.7%, corneal ulceration in 0.04% and corneal scars in 0.04% Of the subsample, 7.2% (95% confidence interval [c.i.] 4.4-10.0%) had serum retinol values below 10 micrograms/dl; 63.0% (95% c.i. 57.6- 68.4%) had values below 20 micrograms/dl. Xerophthalmia and vitamin A deficiency are public health problems in western Yemen.
Atmospheric Science Data Center
2017-10-11
... Spatial Resolution Temporal Coverage CER_GEO_Ed4_GOE08 Hourly 2-4km observation at nadir, subsampled every 8-9 km 2000-03-01 to 2003-04-01 CER_GEO_Ed4_GOE09 Hourly 2-4km observation at nadir, subsampled ...
Inorganic, Radioisotopic, and Organic Analysis of 241-AP-101 Tank Waste
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fiskum, S.K.; Bredt, P.R.; Campbell, J.A.
2000-10-17
Battelle received five samples from Hanford waste tank 241-AP-101, taken at five different depths within the tank. No visible solids or organic layer were observed in the individual samples. Individual sample densities were measured, then the five samples were mixed together to provide a single composite. The composite was homogenized and representative sub-samples taken for inorganic, radioisotopic, and organic analysis. All analyses were performed on triplicate sub-samples of the composite material. The sample composite did not contain visible solids or an organic layer. A subsample held at 10 C for seven days formed no visible solids.
Díaz, Diana B; Brandon, Thomas H; Sutton, Steven K; Meltzer, Lauren R; Hoehn, Hannah J; Meade, Cathy D; Jacobsen, Paul B; McCaffrey, Judith C; Haura, Eric B; Lin, Hui-Yi; Simmons, Vani N
2016-09-01
Continued smoking after a cancer diagnosis contributes to several negative health outcomes. Although many cancer patients attempt to quit smoking, high smoking relapse rates have been observed. This highlights the need for a targeted, evidence-based smoking-relapse prevention intervention. The design, method, and baseline characteristics of a randomized controlled trial assessing the efficacy of a self-help smoking-relapse prevention intervention are presented. Cancer patients who had recently quit smoking were randomized to one of two conditions. The Usual Care (UC) group received the institution's standard of care. The smoking relapse-prevention intervention (SRP) group received standard of care, plus 8 relapse-prevention booklets mailed over a 3month period, and a targeted educational DVD developed specifically for cancer patients. Four hundred and fourteen participants were enrolled and completed a baseline survey. Primary outcomes will be self-reported smoking status at 6 and 12-months after baseline. Biochemical verification of smoking status was completed for a subsample. If found to be efficacious, this low-cost intervention could be easily disseminated with significant potential for reducing the risk of negative cancer outcomes associated with continued smoking. Copyright © 2016 Elsevier Inc. All rights reserved.
Efficient identification of context dependent subgroups of risk from genome wide association studies
Dyson, Greg; Sing, Charles F.
2014-01-01
We have developed a modified Patient Rule-Induction Method (PRIM) as an alternative strategy for analyzing representative samples of non-experimental human data to estimate and test the role of genomic variations as predictors of disease risk in etiologically heterogeneous sub-samples. A computational limit of the proposed strategy is encountered when the number of genomic variations (predictor variables) under study is large (> 500) because permutations are used to generate a null distribution to test the significance of a term (defined by values of particular variables) that characterizes a sub-sample of individuals through the peeling and pasting processes. As an alternative, in this paper we introduce a theoretical strategy that facilitates the quick calculation of Type I and Type II errors in the evaluation of terms in the peeling and pasting processes carried out in the execution of a PRIM analysis that are underestimated and non-existent, respectively, when a permutation-based hypothesis test is employed. The resultant savings in computational time makes possible the consideration of larger numbers of genomic variations (an example genome wide association study is given) in the selection of statistically significant terms in the formulation of PRIM prediction models. PMID:24570412
Contractor, Ateka A; Layne, Christopher M; Steinberg, Alan M; Ostrowski, Sarah A; Ford, Julian D; Elhai, Jon D
2013-12-30
A substantial body of evidence documents that the frequency and intensity of posttraumatic stress disorder (PTSD) symptoms are linked to such demographic variables as female sex (e.g., Kaplow et al., 2005) and age (e.g., Meiser-Stedman et al., 2008). Considerably less is known about relations between biological sex and age with PTSD's latent factor structure. This study systematically examined the roles that sex and age may play as candidate moderators of the full range of factor structure parameters of an empirically supported five-factor PTSD model (Elhai et al., 2011). The sample included 6591 trauma-exposed children and adolescents selected from the National Child Traumatic Stress Network's Core Data Set. Confirmatory factor analysis using invariance testing (Gregorich, 2006) and comparative fit index difference values (Cheung and Rensvold, 2002) reflected a mixed pattern of test item intercepts across age groups. The adolescent subsample produced lower residual error variances, reflecting less measurement error than the child subsample. Sex did not show a robust moderating effect. We conclude by discussing implications for clinical assessment, theory building, and future research. © 2013 Elsevier Ireland Ltd. All rights reserved.
Crewe, Tara L; Taylor, Philip D; Lepage, Denis
2015-01-01
The use of counts of unmarked migrating animals to monitor long term population trends assumes independence of daily counts and a constant rate of detection. However, migratory stopovers often last days or weeks, violating the assumption of count independence. Further, a systematic change in stopover duration will result in a change in the probability of detecting individuals once, but also in the probability of detecting individuals on more than one sampling occasion. We tested how variation in stopover duration influenced accuracy and precision of population trends by simulating migration count data with known constant rate of population change and by allowing daily probability of survival (an index of stopover duration) to remain constant, or to vary randomly, cyclically, or increase linearly over time by various levels. Using simulated datasets with a systematic increase in stopover duration, we also tested whether any resulting bias in population trend could be reduced by modeling the underlying source of variation in detection, or by subsampling data to every three or five days to reduce the incidence of recounting. Mean bias in population trend did not differ significantly from zero when stopover duration remained constant or varied randomly over time, but bias and the detection of false trends increased significantly with a systematic increase in stopover duration. Importantly, an increase in stopover duration over time resulted in a compounding effect on counts due to the increased probability of detection and of recounting on subsequent sampling occasions. Under this scenario, bias in population trend could not be modeled using a covariate for stopover duration alone. Rather, to improve inference drawn about long term population change using counts of unmarked migrants, analyses must include a covariate for stopover duration, as well as incorporate sampling modifications (e.g., subsampling) to reduce the probability that individuals will be detected on more than one occasion.
Signatures of criticality arise from random subsampling in simple population models.
Nonnenmacher, Marcel; Behrens, Christian; Berens, Philipp; Bethge, Matthias; Macke, Jakob H
2017-10-01
The rise of large-scale recordings of neuronal activity has fueled the hope to gain new insights into the collective activity of neural ensembles. How can one link the statistics of neural population activity to underlying principles and theories? One attempt to interpret such data builds upon analogies to the behaviour of collective systems in statistical physics. Divergence of the specific heat-a measure of population statistics derived from thermodynamics-has been used to suggest that neural populations are optimized to operate at a "critical point". However, these findings have been challenged by theoretical studies which have shown that common inputs can lead to diverging specific heat. Here, we connect "signatures of criticality", and in particular the divergence of specific heat, back to statistics of neural population activity commonly studied in neural coding: firing rates and pairwise correlations. We show that the specific heat diverges whenever the average correlation strength does not depend on population size. This is necessarily true when data with correlations is randomly subsampled during the analysis process, irrespective of the detailed structure or origin of correlations. We also show how the characteristic shape of specific heat capacity curves depends on firing rates and correlations, using both analytically tractable models and numerical simulations of a canonical feed-forward population model. To analyze these simulations, we develop efficient methods for characterizing large-scale neural population activity with maximum entropy models. We find that, consistent with experimental findings, increases in firing rates and correlation directly lead to more pronounced signatures. Thus, previous reports of thermodynamical criticality in neural populations based on the analysis of specific heat can be explained by average firing rates and correlations, and are not indicative of an optimized coding strategy. We conclude that a reliable interpretation of statistical tests for theories of neural coding is possible only in reference to relevant ground-truth models.
Test of a mosquito eggshell isolation method and subsampling procedure.
Turner, P A; Streever, W J
1997-03-01
Production of Aedes vigilax, the common salt-marsh mosquito, can be assessed by determining eggshell densities found in soil. In this study, 14 field-collected eggshell samples were used to test a subsampling technique and compare eggshell counts obtained with a flotation method to those obtained by direct examination of sediment (DES). Relative precision of the subsampling technique was assessed by determining the minimum number of subsamples required to estimate the true mean and confidence interval of a sample at a predetermined confidence level. A regression line was fitted to cube-root transformed eggshell counts obtained from flotation and DES and found to be significant (P < 0.001, r2 = 0.97). The flotation method allowed processing of samples in about one-third of the time required by DES, but recovered an average of 44% of the eggshells present. Eggshells obtained with the flotation method can be used to predict those from DES using the following equation: DES count = [1.386 x (flotation count)0.33 - 0.01]3.
Subsampled Hessian Newton Methods for Supervised Learning.
Wang, Chien-Chih; Huang, Chun-Heng; Lin, Chih-Jen
2015-08-01
Newton methods can be applied in many supervised learning approaches. However, for large-scale data, the use of the whole Hessian matrix can be time-consuming. Recently, subsampled Newton methods have been proposed to reduce the computational time by using only a subset of data for calculating an approximation of the Hessian matrix. Unfortunately, we find that in some situations, the running speed is worse than the standard Newton method because cheaper but less accurate search directions are used. In this work, we propose some novel techniques to improve the existing subsampled Hessian Newton method. The main idea is to solve a two-dimensional subproblem per iteration to adjust the search direction to better minimize the second-order approximation of the function value. We prove the theoretical convergence of the proposed method. Experiments on logistic regression, linear SVM, maximum entropy, and deep networks indicate that our techniques significantly reduce the running time of the subsampled Hessian Newton method. The resulting algorithm becomes a compelling alternative to the standard Newton method for large-scale data classification.
Pengra, Bruce; Long, Jordan; Dahal, Devendra; Stehman, Stephen V.; Loveland, Thomas R.
2015-01-01
The methodology for selection, creation, and application of a global remote sensing validation dataset using high resolution commercial satellite data is presented. High resolution data are obtained for a stratified random sample of 500 primary sampling units (5 km × 5 km sample blocks), where the stratification based on Köppen climate classes is used to distribute the sample globally among biomes. The high resolution data are classified to categorical land cover maps using an analyst mediated classification workflow. Our initial application of these data is to evaluate a global 30 m Landsat-derived, continuous field tree cover product. For this application, the categorical reference classification produced at 2 m resolution is converted to percent tree cover per 30 m pixel (secondary sampling unit)for comparison to Landsat-derived estimates of tree cover. We provide example results (based on a subsample of 25 sample blocks in South America) illustrating basic analyses of agreement that can be produced from these reference data. Commercial high resolution data availability and data quality are shown to provide a viable means of validating continuous field tree cover. When completed, the reference classifications for the full sample of 500 blocks will be released for public use.
NASA Astrophysics Data System (ADS)
Wolf, C.; Johnson, A. S.; Bilicki, M.; Blake, C.; Amon, A.; Erben, T.; Glazebrook, K.; Heymans, C.; Hildebrandt, H.; Joudaki, S.; Klaes, D.; Kuijken, K.; Lidman, C.; Marin, F.; Parkinson, D.; Poole, G.
2017-04-01
We present a new training set for estimating empirical photometric redshifts of galaxies, which was created as part of the 2-degree Field Lensing Survey project. This training set is located in a ˜700 deg2 area of the Kilo-Degree-Survey South field and is randomly selected and nearly complete at r < 19.5. We investigate the photometric redshift performance obtained with ugriz photometry from VST-ATLAS and W1/W2 from WISE, based on several empirical and template methods. The best redshift errors are obtained with kernel-density estimation (KDE), as are the lowest biases, which are consistent with zero within statistical noise. The 68th percentiles of the redshift scatter for magnitude-limited samples at r < (15.5, 17.5, 19.5) are (0.014, 0.017, 0.028). In this magnitude range, there are no known ambiguities in the colour-redshift map, consistent with a small rate of redshift outliers. In the fainter regime, the KDE method produces p(z) estimates per galaxy that represent unbiased and accurate redshift frequency expectations. The p(z) sum over any subsample is consistent with the true redshift frequency plus Poisson noise. Further improvements in redshift precision at r < 20 would mostly be expected from filter sets with narrower passbands to increase the sensitivity of colours to small changes in redshift.
Spanish adaptation of the Quality of Life Index-Spinal Cord Injury version.
Kovacs, F M; Barriga, A; Royuela, A; Seco, J; Zamora, J
2016-10-01
A cross-sectional, validation study. To (a) develop the Spanish version of the Quality of Life Index-Spinal Cord Injury version (SV-QLI/SCI) and (b) assess its psychometric characteristics among permanent wheelchair users and specifically among those with SCI. Associations of wheelchair users in Mallorca (Spain). Two forward and backward translations of the QLI/SCI into Spanish were carried out separately. Seventy-seven subjects were randomly selected among the members of the associations. They completed the SV-QLI/SCI and validated instruments to measure depression and spinal pain upon recruitment and 14 days later. Assessments included comprehensibility, reproducibility, floor and ceiling effects and correlations between quality of life, pain and depression (Spearman's correlation coefficient). Analyses were repeated excluding data from subjects without SCI. Three items of the SV-QLI/SCI required rephrasing. Reproducibility was 'almost perfect' for the entire questionnaire and its 'Health and functioning' subscale, 'substantial' for the 'Social and economic' and 'Family' subscales and 'moderate' for the 'Psychological/spiritual' subscale. Floor effect was not observed, and only for the 'Family' subscale >3% of the subjects reached the maximum possible score. The correlation between quality of life and depression was the strongest (r=-0.628). Results were virtually identical in the subsample with SCI. These results support the use of the SV-QLI/SCI among Spanish-speaking wheelchair users.
Latino men's sexual behavior with transgender persons.
Bockting, Walter; Miner, Michael; Rosser, B R Simon
2007-12-01
Male-to-female transgender persons are thought to be "vectors" for HIV/STI transmission, yet little quantitative information exists about the risk behavior of their male sexual partners who may serve as a "bridge" for HIV transmission into the general population. As part of an online survey examining the sexual risk behavior of Latino men who have sex with men (N = 1,026), we identified 44 (4%) participants who reported having had sex with a transgender partner. Compared with a randomly selected sub-sample of 200 men who did not report sex with a transgender person, sexual partners of transgender persons were almost three times more likely to have had unprotected sexual intercourse in the last three months. In addition, men who had sex with transgender persons were more likely to be HIV-positive; married, separated, or divorced; identify as bisexual or straight; have sex with women; and live in rural or small town communities. Regression analysis revealed that community size, sexual compulsivity, and having had a transgender partner were independent predictors of unprotected sex. Among Latino men who have sex with men, men with a history of sex with a transgender person appear more likely to be sexually compulsive and at greater risk for HIV and other sexually transmitted infections. These men may, therefore, also serve as a "bridge" for HIV transmission to (as opposed to from) the transgender population.
GIS-aided Statistical Landslide Susceptibility Modeling And Mapping Of Antipolo Rizal (Philippines)
NASA Astrophysics Data System (ADS)
Dumlao, A. J.; Victor, J. A.
2015-09-01
Slope instability associated with heavy rainfall or earthquake is a familiar geotechnical problem in the Philippines. The main objective of this study is to perform a detailed landslide susceptibility assessment of Antipolo City. The statistical method of assessment used was logistic regression. Landslide inventory was done through interpretation of aerial photographs and satellite images with corresponding field verification. In this study, morphologic and non-morphologic factors contributing to landslide occurrence and their corresponding spatial relationships were considered. The analysis of landslide susceptibility was implemented in a Geographic Information System (GIS). The 17320 randomly selected datasets were divided into training and test data sets. K- cross fold validation is done with k= 5. The subsamples are then fitted five times with k-1 training data set and the remaining fold as the validation data set. The AUROC of each model is validated using each corresponding data set. The AUROC of the five models are; 0.978, 0.977, 0.977, 0.974, and 0.979 respectively, implying that the models are effective in correctly predicting the occurrence and nonoccurrence of landslide activity. Field verification was also done. The landslide susceptibility map was then generated from the model. It is classified into four categories; low, moderate, high and very high susceptibility. The study also shows that almost 40% of Antipolo City has been assessed to be potentially dangerous areas in terms of landslide occurrence.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sistine, Angela Van; Salzer, John J.; Janowiecki, Steven
2016-06-10
The ALFALFA H α survey utilizes a large sample of H i-selected galaxies from the ALFALFA survey to study star formation (SF) in the local universe. ALFALFA H α contains 1555 galaxies with distances between ∼20 and ∼100 Mpc. We have obtained continuum-subtracted narrowband H α images and broadband R images for each galaxy, creating one of the largest homogeneous sets of H α images ever assembled. Our procedures were designed to minimize the uncertainties related to the calculation of the local SF rate density (SFRD). The galaxy sample we constructed is as close to volume-limited as possible, is amore » robust statistical sample, and spans a wide range of galaxy environments. In this paper, we discuss the properties of our Fall sample of 565 galaxies, our procedure for deriving individual galaxy SF rates, and our method for calculating the local SFRD. We present a preliminary value of log(SFRD[ M {sub ⊙} yr{sup −1} Mpc{sup −3}]) = −1.747 ± 0.018 (random) ±0.05 (systematic) based on the 565 galaxies in our Fall sub-sample. Compared to the weighted average of SFRD values around z ≈ 2, our local value indicates a drop in the global SFRD of a factor of 10.2 over that lookback time.« less
The triglyceride and glucose index is useful for recognising insulin resistance in children.
Rodríguez-Morán, M; Simental-Mendía, L E; Guerrero-Romero, F
2017-06-01
Although recognising insulin resistance (IR) in children is particularly important, the gold standard test used to diagnose it, the euglyceamic glucose clamp, is costly, invasive and is not routinely available in our clinical settings in Mexico. This study evaluated whether the triglyceride-glucose (TyG) index would provide a useful alternative. A total of 2779 school children aged seven to 17 years, from Durango, Mexico, were enrolled during 2015-2016. The gold standard euglyceamic-hyperinsulinemic clamp test was performed in a randomly selected subsample of 125 children, and diagnostic concordance between the TyG index and the homoeostasis model assessment of IR was evaluated in all of the 2779 enrolled children. The best cut-off values for recognising IR using the TyG index were 4.65 for prepubertal girls and boys, 4.75 for pubertal girls and 4.70 for pubertal boys. Concordance between the TyG index and the homoeostasis model assessment of IR was 0.910 and 0.902 for the prepubertal girls and boys, 0.932 for the pubertal girls and 0.925 for the pubertal boys. The TyG index was useful for recognising IR in both prepubertal and pubertal children and could provide a feasible alternative to the costly and invasive gold standard test for IR in resource-limited settings. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.
Walsh, Raoul A; Paul, Christine L; Tzelepis, Flora; Stojanovski, Elizabeth; Tang, Anita
2008-10-01
To assess community attitudes towards smoking bans, tobacco availability, promotion and product regulation, tobacco industry donations to political parties, and government spending on tobacco control activities. To compare public preferences on these issues with policies of the NSW and Commonwealth governments. Anonymous, computer assisted telephone interviews of adults from randomly selected households in the NSW Electronic White Pages conducted in 2004. All subjects completed a core question set and subsequently, one of three sub-sets. Overall 49.1% of eligible subjects consented. Data from two sub-samples containing 1,191 and 1,158 subjects are reported. Majority support existed for smoking bans in all six settings assessed: children's playgrounds (89%), sports stadia (77%), licensed premises (72%), outdoor dining (69%), beaches (55%) and motor vehicles carrying children (55%). Respondents nominated vastly higher tobacco control budgets than current levels of government expenditure. On a scale assessing support for tobacco control (maximum score = 13), the mean scores of both non-smokers (10.4) and smokers (8.0) were high. Of seven variables tested, only two: living with a smoker and personal smoking status were independent predictors of having a high pro-tobacco control score. There is strong community support for additional government regulation mandating smoke-free provision and other counter tobacco measures. Continued advocacy campaigns are required to align government tobacco control agenda more closely with public preferences.
50 ways to trace your veteran: increasing response rates can be cheap and effective
Fear, Nicola Townsend; Van Staden, Lauren; Iversen, Amy; Hall, John; Wessely, Simon
2010-01-01
Background while low response rates need not introduce bias into research, having a lower percentage of responders does increase the potential for this to occur. This is of particular concern given the decline that has been occurring in response rates since the 1950s. However, there are various methods that can be incorporated into the study design, which can assist in increasing levels of participation. Objective To outline the methods used by the King's Centre for Military Health Research (KCMHR) when conducting a recent telephone survey of serving and ex-Service military personnel. Design Using participants who had already taken part in a questionnaire-based study on the health effects of serving in the UK Armed Forces (n=10,272), a subsample was selected for an in-depth telephone interview-based follow-up study. The subsample consisted of 1,105 participants, selected on the basis of their mental health status. An adjusted response rate of 76% was achieved (n=821). Results Various methods of contact were used in this study to ensure an adequate response rate was achieved. Conclusions Simple research strategies increase response rates and are likely to reduce bias. Use of multiple simultaneous tracing methods and customisation of the approach to the target population increases rapport between participants, ensuring that those who take part feel valued as members of the study. In the current climate of decreasing participation in studies, research teams need to engage with their study population and devise innovative strategies to keep participants involved in the research being undertaken. PMID:22893795
Bircan, Cavit
2009-01-01
To determine differences in mean aflatoxin contamination and subsample variance from dry and slurry homogenizations, 10 kg of six different, naturally contaminated dried fig samples were collected from various exporting companies in accordance with the EU Commission Directive. The samples were first dry-mixed for 5 min using a blender and sub-sampled seven times; the remainder was slurry homogenized (1 : 1, v/v) and sub-sampled seven times. Aflatoxin B1 and total aflatoxin levels were recorded and coefficient of variations (CV) computed for all sub-samples. Only a small reduction in sub-sample variations, indicated by the lower CV values, and slight differences in mean aflatoxin B1 and total aflatoxin levels were observed when slurry homogenization was applied. Therefore, 7326 dried figs, destined for export from Turkey to the EU and collected during the 2008 crop year, were dry-homogenized and tested for aflatoxins (B1, B2, G1 and G2) by immunoaffinity column clean-up using RP-HPLC. While 34% of the samples contained detectable levels of total aflatoxins (0.20-208.75 µg kg(-1)), only 9% of them exceeded the EU limit of 4 µg kg(-1) in the range 2.0-208.75 µg kg(-1), respectively. A substantial increase in the incidence of aflatoxins was observed in 2008, most likely due to the drought stress experienced in Aydin province as occurred in 2007.
NASA Technical Reports Server (NTRS)
Sehgal, Neelima; Addison, Graeme; Battaglia, Nick; Battistelli, Elia S.; Bond, J. Richard; Das, Sudeep; Devlin, Mark J.; Dunkley, Joanna; Duenner, Rolando; Gralla, Megan;
2012-01-01
We present the measured Sunyaev-Zel'dovich (SZ) flux from 474 optically-selected MaxBCG clusters that fall within the Atacama Cosmology Telescope (ACT) Equatorial survey region. The ACT Equatorial region used in this analysis covers 510 square degrees and overlaps Stripe 82 of the Sloan Digital Sky Survey. We also present the measured SZ flux stacked on 52 X-ray-selected MCXC clusters that fall within the ACT Equatorial region and an ACT Southern survey region covering 455 square degrees. We find that the measured SZ flux from the X-ray-selected clusters is consistent with expectations. However, we find that the measured SZ flux from the optically-selected clusters is both significantly lower than expectations and lower than the recovered SZ flux measured by the Planck satellite. Since we find a lower recovered SZ signal than Planck, we investigate the possibility that there is a significant offset between the optically-selected brightest cluster galaxies (BCGs) and the SZ centers, to which ACT is more sensitive due to its finer resolution. Such offsets can arise due to either an intrinsic physical separation between the BCG and the center of the gas concentration or from misidentification of the cluster BCG. We find that the entire discrepancy for both ACT and Planck can be explained by assuming that the BCGs are offset from the SZ maxima with a uniform random distribution between 0 and 1.5 Mpc. In contrast, the physical separation between BCGs and X-ray peaks for an X-ray-selected subsample of MaxBCG clusters shows a much narrower distribution that peaks within 0.2 Mpc. We conclude that while offsets between BCGs and SZ peaks may be an important component in explaining the discrepancy, it is likely that a combination of factors is responsible for the ACT and Planck measurements. Several effects that can lower the SZ signal equally for both ACT and Planck, but not explain the difference in measured signals, include a larger percentage of false detections in the MaxBCG sample, a lower normalization of the mass-richness relation, radio or infrared galaxy contamination of the SZ flux, and a low intrinsic SZ signal. In the latter two cases, the effects would need to be preferentially more significant in the optically-selected MaxBCG sample than in the MCXC X-ray sample.
Uniform Recovery Bounds for Structured Random Matrices in Corrupted Compressed Sensing
NASA Astrophysics Data System (ADS)
Zhang, Peng; Gan, Lu; Ling, Cong; Sun, Sumei
2018-04-01
We study the problem of recovering an $s$-sparse signal $\\mathbf{x}^{\\star}\\in\\mathbb{C}^n$ from corrupted measurements $\\mathbf{y} = \\mathbf{A}\\mathbf{x}^{\\star}+\\mathbf{z}^{\\star}+\\mathbf{w}$, where $\\mathbf{z}^{\\star}\\in\\mathbb{C}^m$ is a $k$-sparse corruption vector whose nonzero entries may be arbitrarily large and $\\mathbf{w}\\in\\mathbb{C}^m$ is a dense noise with bounded energy. The aim is to exactly and stably recover the sparse signal with tractable optimization programs. In this paper, we prove the uniform recovery guarantee of this problem for two classes of structured sensing matrices. The first class can be expressed as the product of a unit-norm tight frame (UTF), a random diagonal matrix and a bounded columnwise orthonormal matrix (e.g., partial random circulant matrix). When the UTF is bounded (i.e. $\\mu(\\mathbf{U})\\sim1/\\sqrt{m}$), we prove that with high probability, one can recover an $s$-sparse signal exactly and stably by $l_1$ minimization programs even if the measurements are corrupted by a sparse vector, provided $m = \\mathcal{O}(s \\log^2 s \\log^2 n)$ and the sparsity level $k$ of the corruption is a constant fraction of the total number of measurements. The second class considers randomly sub-sampled orthogonal matrix (e.g., random Fourier matrix). We prove the uniform recovery guarantee provided that the corruption is sparse on certain sparsifying domain. Numerous simulation results are also presented to verify and complement the theoretical results.
Dermal exposure studies incorporating urinary biomarker measurements are complicated because dermal sampling may intercept or remove the target chemical before it is absorbed. A hand wipe subsampling method has been developed using polyurethane foam-tipped (PUF) swabs to minim...
NASA Astrophysics Data System (ADS)
Zhang, Qian; Ball, William P.
2017-04-01
Regression-based approaches are often employed to estimate riverine constituent concentrations and fluxes based on typically sparse concentration observations. One such approach is the recently developed WRTDS ("Weighted Regressions on Time, Discharge, and Season") method, which has been shown to provide more accurate estimates than prior approaches in a wide range of applications. Centered on WRTDS, this work was aimed at developing improved models for constituent concentration and flux estimation by accounting for antecedent discharge conditions. Twelve modified models were developed and tested, each of which contains one additional flow variable to represent antecedent conditions and which can be directly derived from the daily discharge record. High-resolution (∼daily) data at nine diverse monitoring sites were used to evaluate the relative merits of the models for estimation of six constituents - chloride (Cl), nitrate-plus-nitrite (NOx), total Kjeldahl nitrogen (TKN), total phosphorus (TP), soluble reactive phosphorus (SRP), and suspended sediment (SS). For each site-constituent combination, 30 concentration subsets were generated from the original data through Monte Carlo subsampling and then used to evaluate model performance. For the subsampling, three sampling strategies were adopted: (A) 1 random sample each month (12/year), (B) 12 random monthly samples plus additional 8 random samples per year (20/year), and (C) flow-stratified sampling with 12 regular (non-storm) and 8 storm samples per year (20/year). Results reveal that estimation performance varies with both model choice and sampling strategy. In terms of model choice, the modified models show general improvement over the original model under all three sampling strategies. Major improvements were achieved for NOx by the long-term flow-anomaly model and for Cl by the ADF (average discounted flow) model and the short-term flow-anomaly model. Moderate improvements were achieved for SS, TP, and TKN by the ADF model. By contrast, no such achievement was achieved for SRP by any proposed model. In terms of sampling strategy, performance of all models (including the original) was generally best using strategy C and worst using strategy A, and especially so for SS, TP, and SRP, confirming the value of routinely collecting stormflow samples. Overall, this work provides a comprehensive set of statistical evidence for supporting the incorporation of antecedent discharge conditions into the WRTDS model for estimation of constituent concentration and flux, thereby combining the advantages of two recent developments in water quality modeling.
NASA Astrophysics Data System (ADS)
Jiang, Kaili; Zhu, Jun; Tang, Bin
2017-12-01
Periodic nonuniform sampling occurs in many applications, and the Nyquist folding receiver (NYFR) is an efficient, low complexity, and broadband spectrum sensing architecture. In this paper, we first derive that the radio frequency (RF) sample clock function of NYFR is periodic nonuniform. Then, the classical results of periodic nonuniform sampling are applied to NYFR. We extend the spectral reconstruction algorithm of time series decomposed model to the subsampling case by using the spectrum characteristics of NYFR. The subsampling case is common for broadband spectrum surveillance. Finally, we take example for a LFM signal under large bandwidth to verify the proposed algorithm and compare the spectral reconstruction algorithm with orthogonal matching pursuit (OMP) algorithm.
Duffy, Frank H; Als, Heidelise
2012-06-26
The autism rate has recently increased to 1 in 100 children. Genetic studies demonstrate poorly understood complexity. Environmental factors apparently also play a role. Magnetic resonance imaging (MRI) studies demonstrate increased brain sizes and altered connectivity. Electroencephalogram (EEG) coherence studies confirm connectivity changes. However, genetic-, MRI- and/or EEG-based diagnostic tests are not yet available. The varied study results likely reflect methodological and population differences, small samples and, for EEG, lack of attention to group-specific artifact. Of the 1,304 subjects who participated in this study, with ages ranging from 1 to 18 years old and assessed with comparable EEG studies, 463 children were diagnosed with autism spectrum disorder (ASD); 571 children were neuro-typical controls (C). After artifact management, principal components analysis (PCA) identified EEG spectral coherence factors with corresponding loading patterns. The 2- to 12-year-old subsample consisted of 430 ASD- and 554 C-group subjects (n = 984). Discriminant function analysis (DFA) determined the spectral coherence factors' discrimination success for the two groups. Loading patterns on the DFA-selected coherence factors described ASD-specific coherence differences when compared to controls. Total sample PCA of coherence data identified 40 factors which explained 50.8% of the total population variance. For the 2- to 12-year-olds, the 40 factors showed highly significant group differences (P < 0.0001). Ten randomly generated split half replications demonstrated high-average classification success (C, 88.5%; ASD, 86.0%). Still higher success was obtained in the more restricted age sub-samples using the jackknifing technique: 2- to 4-year-olds (C, 90.6%; ASD, 98.1%); 4- to 6-year-olds (C, 90.9%; ASD 99.1%); and 6- to 12-year-olds (C, 98.7%; ASD, 93.9%). Coherence loadings demonstrated reduced short-distance and reduced, as well as increased, long-distance coherences for the ASD-groups, when compared to the controls. Average spectral loading per factor was wide (10.1 Hz). Classification success suggests a stable coherence loading pattern that differentiates ASD- from C-group subjects. This might constitute an EEG coherence-based phenotype of childhood autism. The predominantly reduced short-distance coherences may indicate poor local network function. The increased long-distance coherences may represent compensatory processes or reduced neural pruning. The wide average spectral range of factor loadings may suggest over-damped neural networks.
On the universality of the two-point galaxy correlation function
NASA Technical Reports Server (NTRS)
Davis, Marc; Meiksin, Avery; Strauss, Michael A.; Da Costa, L. Nicolaci; Yahil, Amos
1988-01-01
The behavior of the two-point galaxy correlation function in volume-limited subsamples of three complete redshift surveys is investigated. The correlation length is shown to scale approximately as the square root of the distance limit in both the CfA and Southern Sky catalogs, but to be independent of the distance limit in the IRAS sample. This effect is found to be due to factors such as the large positive density fluctuations in the foreground of the optically selected catalogs biasing the correlation length estimate downward, and the brightest galaxies appearing to be more strongly clustered than the mean.
Tank 241-B-108, cores 172 and 173 analytical results for the final report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nuzum, J.L., Fluoro Daniel Hanford
1997-03-04
The Data Summary Table (Table 3) included in this report compiles analytical results in compliance with all applicable DQOS. Liquid subsamples that were prepared for analysis by an acid adjustment of the direct subsample are indicated by a `D` in the A column in Table 3. Solid subsamples that were prepared for analysis by performing a fusion digest are indicated by an `F` in the A column in Table 3. Solid subsamples that were prepared for analysis by performing a water digest are indicated by a I.wl. or an `I` in the A column of Table 3. Due to poormore » precision and accuracy in original analysis of both Lower Half Segment 2 of Core 173 and the core composite of Core 173, fusion and water digests were performed for a second time. Precision and accuracy improved with the repreparation of Core 173 Composite. Analyses with the repreparation of Lower Half Segment 2 of Core 173 did not show improvement and suggest sample heterogeneity. Results from both preparations are included in Table 3.« less
Vienola, Kari V; Damodaran, Mathi; Braaf, Boy; Vermeer, Koenraad A; de Boer, Johannes F
2018-02-01
Retinal motion detection with an accuracy of 0.77 arcmin corresponding to 3.7 µm on the retina is demonstrated with a novel digital micromirror device based ophthalmoscope. By generating a confocal image as a reference, eye motion could be measured from consecutively measured subsampled frames. The subsampled frames provide 7.7 millisecond snapshots of the retina without motion artifacts between the image points of the subsampled frame, distributed over the full field of view. An ophthalmoscope pattern projection speed of 130 Hz enabled a motion detection bandwidth of 65 Hz. A model eye with a scanning mirror was built to test the performance of the motion detection algorithm. Furthermore, an in vivo motion trace was obtained from a healthy volunteer. The obtained eye motion trace clearly shows the three main types of fixational eye movements. Lastly, the obtained eye motion trace was used to correct for the eye motion in consecutively obtained subsampled frames to produce an averaged confocal image correct for motion artefacts.
Vienola, Kari V.; Damodaran, Mathi; Braaf, Boy; Vermeer, Koenraad A.; de Boer, Johannes F.
2018-01-01
Retinal motion detection with an accuracy of 0.77 arcmin corresponding to 3.7 µm on the retina is demonstrated with a novel digital micromirror device based ophthalmoscope. By generating a confocal image as a reference, eye motion could be measured from consecutively measured subsampled frames. The subsampled frames provide 7.7 millisecond snapshots of the retina without motion artifacts between the image points of the subsampled frame, distributed over the full field of view. An ophthalmoscope pattern projection speed of 130 Hz enabled a motion detection bandwidth of 65 Hz. A model eye with a scanning mirror was built to test the performance of the motion detection algorithm. Furthermore, an in vivo motion trace was obtained from a healthy volunteer. The obtained eye motion trace clearly shows the three main types of fixational eye movements. Lastly, the obtained eye motion trace was used to correct for the eye motion in consecutively obtained subsampled frames to produce an averaged confocal image correct for motion artefacts. PMID:29552396
Rhee, Siyon; Lee, Sei-Young; Jung, Sook-Hee
2017-10-01
This study examines ethnic differences in the prevalence of bullying victimization by peers as well as the associations between bullying victimization and psychological distress with relevant ecological factors including parental supervision, school support, and community safety. The study utilized the 2011-2012 California Health Interview Survey (CHIS) Adolescents Data, which was collected in the United States using a multi-stage stratified sampling design with a Random Digit-Dial method. The final study sample contained a total of 2367 adolescents, comprised of 48.7% Whites, followed by 35.8% Latinos, 11.1% Asians, and 4.4% African Americans. About 49.3% were males with an overall mean age of 14.6 (sd = 1.7). Results showed that there were significant differences in rates of bullying victimization among the four surveyed ethnic subgroups of adolescents. Black adolescents reported the highest and Asian adolescents the lowest level of victimization. The results of the SEM test using the calibration sample revealed an adequate fit to the data (CFI = 0.95, RMSEA = 0.04, Δχ 2 /Δdf = 2.99). Separate model tests with the four subgroups of adolescents revealed good fits with the subsample data with the exception of the subsample of African Americans. Additionally, results show that factors associated with psychological distress vary widely among the White, Latino and Asian subgroups. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.
Thompson, Sanna J; Bender, Kimberly A; Lewis, Carol M; Watkins, Rita
2008-08-01
Homeless youth are at particularly high risk for teen pregnancy; research indicates as many as 20% of homeless young women become pregnant. These pregnant and homeless teens lack financial resources and adequate health care, resulting in increased risk for low-birth-weight babies and high infant mortality. This study investigated individual and family-level predictors of teen pregnancy among a national sample of runaway/homeless youth in order to better understand the needs of this vulnerable population. Data from the Runaway/Homeless Youth Management Information System (RHY MIS) provided a national sample of youth seeking services at crisis shelters. A sub-sample of pregnant females and a random sub-sample (matched by age) of nonpregnant females comprised the study sample (N = 951). Chi-square and t tests identified differences between pregnant and nonpregnant runaway females; maximum likelihood logistic regression identified individual and family-level predictors of teen pregnancy. Teen pregnancy was associated with being an ethnic minority, dropping out of school, being away from home for longer periods of time, having a sexually transmitted disease, and feeling abandoned by one's family. Family factors, such as living in a single parent household and experiencing emotional abuse by one's mother, increased the odds of a teen being pregnant. The complex problems associated with pregnant runaway/homeless teens create challenges for short-term shelter services. Suggestions are made for extending shelter services to include referrals and coordination with teen parenting programs and other systems of care.
Kaiser, Lee D; Melemed, Allen S; Preston, Alaknanda J; Chaudri Ross, Hilary A; Niedzwiecki, Donna; Fyfe, Gwendolyn A; Gough, Jacqueline M; Bushnell, William D; Stephens, Cynthia L; Mace, M Kelsey; Abrams, Jeffrey S; Schilsky, Richard L
2010-12-01
Although much is known about the safety of an anticancer agent at the time of initial marketing approval, sponsors customarily collect comprehensive safety data for studies that support supplemental indications. This adds significant cost and complexity to the study but may not provide useful new information. The main purpose of this analysis was to assess the amount of safety and concomitant medication data collected to determine a more optimal approach in the collection of these data when used in support of supplemental applications. Following a prospectively developed statistical analysis plan, we reanalyzed safety data from eight previously completed prospective randomized trials. A total of 107,884 adverse events and 136,608 concomitant medication records were reviewed for the analysis. Of these, four grade 1 to 2 and nine grade 3 and higher events were identified as drug effects that were not included in the previously established safety profiles and could potentially have been missed using subsampling. These events were frequently detected in subsamples of 400 patients or larger. Furthermore, none of the concomitant medication records contributed to labeling changes for the supplemental indications. Our study found that applying the optimized methodologic approach, described herein, has a high probability of detecting new drug safety signals. Focusing data collection on signals that cause physicians to modify or discontinue treatment ensures that safety issues of the highest concern for patients and regulators are captured and has significant potential to relieve strain on the clinical trials system.
A novel stress and coping workplace program reduces illness and healthcare utilization.
Rahe, Richard H; Taylor, C Barr; Tolles, Robbyn L; Newhall, Lynn M; Veach, Tracy L; Bryson, Susan
2002-01-01
The purpose of this study was to determine if a novel workplace stress management program, delivered either face-to-face or by self-help, would reduce illness and health services utilization among participants. Five hundred one volunteers were randomly allocated to one of three groups: full intervention, which received assessment and personalized self-study feedback and was offered six face-to-face, small-group sessions; partial intervention, a self-help group that received assessment and personalized feedback by mail; and a wait-list control group. All participants completed questionnaires for stress, anxiety, and coping at the start of the study and 6 and 12 months later. Health reports were completed at 0, 3, 6, 9, and 12 months. A subsample of subjects who subscribed to a single health maintenance organization provided objectively recorded doctor visit data across the study year. All three groups reported significant improvement in their stress, anxiety, and coping across the year. Full intervention participants showed a more rapid reduction in negative responses to stress than did participants from the other groups. Full-intervention subjects also reported fewer days of illness than subjects in the other groups. Objectively measured physician visits showed a large (34%) reduction in healthcare utilization for full intervention subjects in the HMO subsample. These results indicated that a work-site program that focuses on stress, anxiety, and coping measurement along with small-group educational intervention can significantly reduce illness and healthcare utilization.
Understanding men's attributions of why they ejaculate before desired: an internet study.
Rowland, David L; Neal, Cody J
2014-10-01
Recent developments in the study of men's sexual response have raised significant issues related to the definition and diagnosis of premature ejaculation (PE). We wanted to understand men's perceived reasons for "ejaculating before they wanted," whether they selected attributions from the same broad category when allowed to endorse multiple reasons, and whether younger and older cohorts differed in their attributions. A subsample of 376 men who indicated that they "ejaculated before they wanted" was drawn from a larger pool of 1,249 men participating in an online survey on men's sexual health. This subsample responded to a number of items regarding their ejaculatory patterns, including two questions listing 10 possible self-reported attributions/reasons for their quick ejaculation--one item allowed respondents to endorse multiple reasons, the other limited the response to the most important reason. The primary outcome measure was men's attributions for ejaculating before desired, with choices from 10 possible pretested reasons. In addition, concordance across attributions was determined, that is, if a man responded to one category, was he also likely to select another category? Men who met the ejaculatory latency criterion for PE were generally no different from those who did not. Overall, when required to select the most important attribution, most men identified a specific issue with "lack of self-efficacy" (lack of control or aroused too quickly). Few respondents identified erection loss, partner issues, or medical/medication concerns as the reason--and these patterns were independent of age. Concordance was high across self-efficacy attributions but low across other attributions. Most men who complain of ejaculating before desired attribute this response to problems with self-efficacy. Only a small percent of men identified other possible reasons for their quick ejaculation. Such findings have implications for both the diagnostic process and definitional language for PE. © 2014 International Society for Sexual Medicine.
A sampling plan for riparian birds of the Lower Colorado River-Final Report
Bart, Jonathan; Dunn, Leah; Leist, Amy
2010-01-01
A sampling plan was designed for the Bureau of Reclamation for selected riparian birds occurring along the Colorado River from Lake Mead to the southerly International Boundary with Mexico. The goals of the sampling plan were to estimate long-term trends in abundance and investigate habitat relationships especially in new habitat being created by the Bureau of Reclamation. The initial objective was to design a plan for the Gila Woodpecker (Melanerpes uropygialis), Arizona Bell's Vireo (Vireo bellii arizonae), Sonoran Yellow Warbler (Dendroica petechia sonorana), Summer Tanager (Piranga rubra), Gilded Flicker (Colaptes chrysoides), and Vermilion Flycatcher (Pyrocephalus rubinus); however, too little data were obtained for the last two species. Recommendations were therefore based on results for the first four species. The study area was partitioned into plots of 7 to 23 hectares. Plot borders were drawn to place the best habitat for the focal species in the smallest number of plots so that survey efforts could be concentrated on these habitats. Double sampling was used in the survey. In this design, a large sample of plots is surveyed a single time, yielding estimates of unknown accuracy, and a subsample is surveyed intensively to obtain accurate estimates. The subsample is used to estimate detection ratios, which are then applied to the results from the extensive survey to obtain unbiased estimates of density and population size. These estimates are then used to estimate long-term trends in abundance. Four sampling plans for selecting plots were evaluated based on a simulation using data from the Breeding Bird Survey. The design with the highest power involved selecting new plots every year. Power with 80 plots surveyed per year was more than 80 percent for three of the four species. Results from the surveys were used to provide recommendations to the Bureau of Reclamation for their surveys of new habitat being created in the study area.
NASA Astrophysics Data System (ADS)
O'Sullivan, Ewan; Ponman, Trevor J.; Kolokythas, Konstantinos; Raychaudhury, Somak; Babul, Arif; Vrtilek, Jan M.; David, Laurence P.; Giacintucci, Simona; Gitti, Myriam; Haines, Chris P.
2017-12-01
We present the Complete Local-Volume Groups Sample (CLoGS), a statistically complete optically selected sample of 53 groups within 80 Mpc. Our goal is to combine X-ray, radio and optical data to investigate the relationship between member galaxies, their active nuclei and the hot intra-group medium (IGM). We describe sample selection, define a 26-group high-richness subsample of groups containing at least four optically bright (log LB ≥ 10.2 LB⊙) galaxies, and report the results of XMM-Newton and Chandra observations of these systems. We find that 14 of the 26 groups are X-ray bright, possessing a group-scale IGM extending at least 65 kpc and with luminosity >1041 erg s-1, while a further three groups host smaller galaxy-scale gas haloes. The X-ray bright groups have masses in the range M500 ≃ 0.5-5 × 1013 M⊙, based on system temperatures of 0.4-1.4 keV, and X-ray luminosities in the range 2-200 × 1041 erg s-1. We find that ∼53-65 per cent of the X-ray bright groups have cool cores, a somewhat lower fraction than found by previous archival surveys. Approximately 30 per cent of the X-ray bright groups show evidence of recent dynamical interactions (mergers or sloshing), and ∼35 per cent of their dominant early-type galaxies host active galactic nuclei with radio jets. We find no groups with unusually high central entropies, as predicted by some simulations, and confirm that CLoGS is in principle capable of detecting such systems. We identify three previously unrecognized groups, and find that they are either faint (LX, R500 < 1042 erg s-1) with no concentrated cool core, or highly disturbed. This leads us to suggest that ∼20 per cent of X-ray bright groups in the local universe may still be unidentified.
Forecasting European cold waves based on subsampling strategies of CMIP5 and Euro-CORDEX ensembles
NASA Astrophysics Data System (ADS)
Cordero-Llana, Laura; Braconnot, Pascale; Vautard, Robert; Vrac, Mathieu; Jezequel, Aglae
2016-04-01
Forecasting future extreme events under the present changing climate represents a difficult task. Currently there are a large number of ensembles of simulations for climate projections that take in account different models and scenarios. However, there is a need for reducing the size of the ensemble to make the interpretation of these simulations more manageable for impact studies or climate risk assessment. This can be achieved by developing subsampling strategies to identify a limited number of simulations that best represent the ensemble. In this study, cold waves are chosen to test different approaches for subsampling available simulations. The definition of cold waves depends on the criteria used, but they are generally defined using a minimum temperature threshold, the duration of the cold spell as well as their geographical extend. These climate indicators are not universal, highlighting the difficulty of directly comparing different studies. As part of the of the CLIPC European project, we use daily surface temperature data obtained from CMIP5 outputs as well as Euro-CORDEX simulations to predict future cold waves events in Europe. From these simulations a clustering method is applied to minimise the number of ensembles required. Furthermore, we analyse the different uncertainties that arise from the different model characteristics and definitions of climate indicators. Finally, we will test if the same subsampling strategy can be used for different climate indicators. This will facilitate the use of the subsampling results for a wide number of impact assessment studies.
Chung, Kuo-Liang; Hsu, Tsu-Chun; Huang, Chi-Chao
2017-10-01
In this paper, we propose a novel and effective hybrid method, which joins the conventional chroma subsampling and the distortion-minimization-based luma modification together, to improve the quality of the reconstructed RGB full-color image. Assume the input RGB full-color image has been transformed to a YUV image, prior to compression. For each 2×2 UV block, one 4:2:0 subsampling is applied to determine the one subsampled U and V components, U s and V s . Based on U s , V s , and the corresponding 2×2 original RGB block, a main theorem is provided to determine the ideally modified 2×2 luma block in constant time such that the color peak signal-to-noise ratio (CPSNR) quality distortion between the original 2×2 RGB block and the reconstructed 2×2 RGB block can be minimized in a globally optimal sense. Furthermore, the proposed hybrid method and the delivered theorem are adjusted to tackle the digital time delay integration images and the Bayer mosaic images whose Bayer CFA structure has been widely used in modern commercial digital cameras. Based on the IMAX, Kodak, and screen content test image sets, the experimental results demonstrate that in high efficiency video coding, the proposed hybrid method has substantial quality improvement, in terms of the CPSNR quality, visual effect, CPSNR-bitrate trade-off, and Bjøntegaard delta PSNR performance, of the reconstructed RGB images when compared with existing chroma subsampling schemes.
Energy and protein requirements for maintenance and growth of Boer crossbred kids.
Fernandes, M H M R; Resende, K T; Tedeschi, L O; Fernandes, J S; Silva, H M; Carstens, G E; Berchielli, T T; Teixeira, I A M A; Akinaga, L
2007-04-01
Meat production by goats has become an important livestock enterprise in several parts of the world. Nonetheless, energy and protein requirements of meat goats have not been defined thoroughly. The objective of this study was to determine the energy and protein requirements for maintenance and growth of 34 (3/4) Boer x (1/4) Saanen crossbred, intact male kids (20.5 +/- 0.24 kg of initial BW). The baseline group was 7 randomly selected kids, averaging 21.2 +/- 0.36 kg of BW. An intermediate group consisted of 6 randomly selected kids, fed for ad libitum intake, that were slaughtered when they reached an average BW of 28.2 +/- 0.39 kg. The remaining kids (n = 21) were allocated randomly on d 0 to 3 levels of DMI (treatments were ad libitum or restricted to 70 or 40% of the ad libitum intake) within 7 slaughter groups. A slaughter group contained 1 kid from each treatment, and kids were slaughtered when the ad libitum treatment kid reached 35 kg of BW. Individual body components (head plus feet, hide, internal organs plus blood, and carcass) were weighed, ground, mixed, and subsampled for chemical analyses. Initial body composition was determined using equations developed from the composition of the baseline kids. The calculated daily maintenance requirement for NE was 77.3 +/- 1.05 kcal/kg(0.75) of empty BW (EBW) or 67.4 +/- 1.04 kcal/kg(0.75) of shrunk BW. The daily ME requirement for maintenance (118.1 kcal/kg(0.75) of EBW or 103.0 kcal/kg(0.75) of shrunk BW) was calculated by iteration, assuming that the heat produced was equal to the ME intake at maintenance. The partial efficiency of use of ME for NE below maintenance was 0.65. A value of 2.44 +/- 0.4 g of net protein/kg(0.75) of EBW for daily maintenance was determined. Net energy requirements for growth ranged from 2.55 to 3.0 Mcal/kg of EBW gain at 20 and 35 kg of BW, and net protein requirements for growth ranged from 178.8 to 185.2 g/kg of EBW gain. These results suggest that NE and net protein requirements for growing meat goats exceed the requirements previously published for dairy goats. Moreover, results from this study suggest that the N requirement for maintenance for growing goats is greater than the established recommendations.
De Jong, G D; Hoback, W W
2006-06-01
Carrion insect succession studies have historically used repeated sampling of single or a few carcasses to produce data, either weighing the carcasses, removing a qualitative subsample of the fauna present, or both, on every visit over the course of decomposition and succession. This study, conducted in a set of related experimental hypotheses with two trials in a single season, investigated the effect that repeated sampling has on insect succession, determined by the number of taxa collected on each visit and by community composition. Each trial lasted at least 21 days, with daily visits on the first 14 days. Rat carcasses used in this study were all placed in the field on the same day, but then either sampled qualitatively on every visit (similar to most succession studies) or ignored until a given day of succession, when they were sampled qualitatively (a subsample) and then destructively sampled in their entirety. Carcasses sampled on every visit were in two groups: those from which only a sample of the fauna was taken and those from which a sample of fauna was taken and the carcass was weighed for biomass determination. Of the carcasses visited only once, the number of taxa in subsamples was compared to the actual number of taxa present when the carcass was destructively sampled to determine if the subsamples adequately represented the total carcass fauna. Data from the qualitative subsamples of those carcasses visited only once were also compared to data collected from carcasses that were sampled on every visit to investigate the effect of the repeated sampling. A total of 39 taxa were collected from carcasses during the study and the component taxa are discussed individually in relation to their role in succession. Number of taxa differed on only one visit between the qualitative subsamples and the actual number of taxa present, primarily because the organisms missed by the qualitative sampling were cryptic (hidden deep within body cavities) or rare (only represented by very few specimens). There were no differences discovered between number of taxa in qualitative subsamples from carcasses sampled repeatedly (with or without biomass determinations) and those sampled only a single time. Community composition differed considerably in later stages of decomposition, with disparate communities due primarily to small numbers of rare taxa. These results indicate that the methods used historically for community composition determination in experimental forensic entomology are generally adequate.
VizieR Online Data Catalog: Galaxy properties in clusters. II. (Muriel+, 2014)
NASA Astrophysics Data System (ADS)
Muriel, H.; Coenda, V.
2014-06-01
In paper I (Coenda & Muriel, 2009A&A...504..347C, Cat. J/A+A/504/347), we selected an X-ray sample of 49 clusters of galaxies from Popesso et al. (2004A&A...423..449P, Cat. J/A+A/423/449, hereafter P04) in the redshift range 0.05
Bellows, Anne C; Alcaraz V, Gabriela; Hallman, William K
2010-12-01
Food choice is influenced by consumer attitudes towards food attributes. This U.S.-based study (n = 601) simultaneously compares attitudes towards selected food attributes of organic, locally grown, U.S. grown, and GM-free food in relation to other food attributes. Exploratory factor analysis identifies underlying constructs that determine, together and separately, female and male food choice decisions. Gendered analysis of the value of food in life and food behaviours (cooking and shopping) support the investigation of the highlighted food attributes. Respondents generally assigned greater importance to the U.S. grown, followed by GM-free, locally grown, and organically produced food attributes in deciding what to eat. Analysis of the female and male subsamples yielded similar factor results. All four main attributes were captured in a single factor, associated with respondents in both the female and male subsamples who are older, have lower incomes, and who are religiously observant. Additionally, among females, this factor was associated with higher education; and among males, living in households with children and/or with partners. Additional studies should further explore the interaction of food attributes now becoming increasingly important and prevalent in current food products. Copyright © 2010 Elsevier Ltd. All rights reserved.
Verdurmen, Jacqueline E E; Koning, Ina M; Vollebergh, Wilma A M; van den Eijnden, Regina J J M; Engels, Rutger C M E
2014-03-01
To examine risk moderation of an alcohol intervention targeting parents and adolescents. A cluster randomized trial including 2937 Dutch early adolescents (m=12.68years, SD=0.51) and their parents randomized over four conditions: parent intervention, student intervention, combined parent-student intervention, and control group. 152 classes of 19 high schools in The Netherlands (2006). Moderators at baseline (adolescent: gender, educational level and externalizing behavior; parent: educational level and heavy alcohol use) were used to examine the differential effects of the interventions on onset of (heavy) weekly drinking at 22-month follow-up. The combined intervention effectively delayed the onset of weekly drinking in the general population of adolescents, and was particularly effective in delaying the onset of heavy weekly drinking in a higher-risk subsample of adolescents (i.e. those attending lower levels of education and reporting higher levels of externalizing behavior). Present and previous results have established the combined intervention to be universally effective in postponing weekly alcohol use among Dutch adolescents, with an added effect on postponing heavy weekly drinking in high risk subgroups. Therefore, implementation of this intervention in the general population of schools in The Netherlands is advised. NTR649. Copyright © 2013 Elsevier Inc. All rights reserved.
Huang, Jin; Sherraden, Michael; Purnell, Jason Q
2014-07-01
This study examines the impact of Child Development Accounts (CDAs)-asset-building accounts created for children at birth-on the depressive symptoms of mothers in a statewide randomized experiment conducted in the United States. The experiment identified the primary caregivers of children born in Oklahoma during 2007, and 2704 of the caregivers completed a baseline interview before random assignment to the treatment (n = 1358) or the control group (n = 1346). To treatment participants, the experiment offered CDAs built on the existing Oklahoma 529 College Savings Plan. The baseline and follow-up surveys measured the participants' depressive symptoms with a shortened version of the Center for Epidemiologic Studies Depression Scale (CES-D). In models that control for baseline CES-D scores, the mean follow-up score of treatment mothers is .17 lower than that of control mothers (p < .05). Findings suggest that CDAs have a greater impact among subsamples that reported lower income or lower education. Although designed as an economic intervention for children, CDAs may improve parents' psychological well-being. Findings also suggest that CDAs' impacts on maternal depressive symptoms may be partially mediated through children's social-emotional development. Copyright © 2014 Elsevier Ltd. All rights reserved.
The Influence of Family Climate and Family Process on Child Development.
ERIC Educational Resources Information Center
Bell, Linda G.; Bell, David C.
This study investigates the relationship between the degree of individuation in families and the personality development of adolescent family members. A subsample of 30 white, middle-class families were chosen for analysis from a larger sample of 99 families. Fifteen families from the subsample had adolescent girls who scored high, and fifteen had…
The Impact of WIC on Birth Outcomes: New Evidence from South Carolina.
Sonchak, Lyudmyla
2016-07-01
Objectives To investigate the impact of the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) on a variety of infant health outcomes using recent South Carolina Vital Statistics data (2004-2012). Methods To account for non-random WIC participation, the study relies on a maternal fixed effects estimation, due to the availability of unique maternally linked data. Results The results indicate that WIC participation is associated with an increase in birth weight and length of gestation, decrease in the probability of low birth weight, prematurity, and Neonatal Intensive Care Unit admission. Additionally, addressing gestational bias and accounting for the length of gestation, WIC participation is associated with a decrease in the probability of delivering a low weight infant and a small for gestational age infant among black mothers. Conclusions for Practice Accounting for non-random program participation, the study documents a large improvement in birth outcomes among infants of WIC participating mothers. Even in the context of somewhat restrictive gestation-adjusted specification, the positive impact of WIC remains within the subsample of black mothers.
Mammography Adherence in African-American Women: Results of a Randomized Controlled Trial.
Gathirua-Mwangi, Wambui G; Monahan, Patrick O; Stump, Timothy; Rawl, Susan M; Skinner, Celette Sugg; Champion, Victoria L
2016-02-01
Breast cancer is the second leading cause of cancer mortality among women in the developed world. Mammography screening is especially important for African-Americans because they experience a greater mortality (OR = 1.38) than Caucasians despite having a lower incidence of breast cancer. The purpose of this study was to compare the effects of two interventions with usual care on mammography adherence among African-American women. A subsample of African-American women (n = 244) aged 41-65 years who had not had a mammogram in the last 15 months and no history of breast cancer was randomly assigned to receive (1) mailed interactive DVD, (2) computer-tailored telephone counseling, or (3) usual care. The DVD intervention was five times more effective than usual care for promoting mammography screening at 6 months follow-up among women who earned less than $30,000 (OR = 5.3). Compared to usual care, neither the DVD nor phone produced significant effects for women with household incomes >$30,000. Use of a mailed DVD for low-income African-American women may be an effective way to increase mammography adherence.
Murray, N G; Kelder, S H; Parcel, G S; Frankowski, R; Orpinas, P
1999-06-01
This paper reports the results of a randomized trial to test the effectiveness of a theoretically derived intervention designed to increase parental monitoring among Hispanic parents of middle school students. Role model story newsletters developed through the process of Intervention Mapping were mailed to half of a subsample of parents whose children participated in Students for Peace, a comprehensive violence prevention program. The results indicated that parents in the experimental condition (N = 38) who had lower social norms for monitoring at baseline reported higher norms after the intervention than the parents in the control condition (N = 39) (P = 0.009). Children of parents in the experimental group reported slightly higher levels of monitoring at follow-up across baseline values, whereas control children who reported moderate to high levels of monitoring at pre-test reported lower levels at follow-up (P = 0.04). These newsletters are a population-based strategy for intervention with parents that show some promise for comprehensive school-based interventions for youth.
Random forest classification of stars in the Galactic Centre
NASA Astrophysics Data System (ADS)
Plewa, P. M.
2018-05-01
Near-infrared high-angular resolution imaging observations of the Milky Way's nuclear star cluster have revealed all luminous members of the existing stellar population within the central parsec. Generally, these stars are either evolved late-type giants or massive young, early-type stars. We revisit the problem of stellar classification based on intermediate-band photometry in the K band, with the primary aim of identifying faint early-type candidate stars in the extended vicinity of the central massive black hole. A random forest classifier, trained on a subsample of spectroscopically identified stars, performs similarly well as competitive methods (F1 = 0.85), without involving any model of stellar spectral energy distributions. Advantages of using such a machine-trained classifier are a minimum of required calibration effort, a predictive accuracy expected to improve as more training data become available, and the ease of application to future, larger data sets. By applying this classifier to archive data, we are also able to reproduce the results of previous studies of the spatial distribution and the K-band luminosity function of both the early- and late-type stars.
Songhurst, Anna; Coulson, Tim
2014-03-01
Few universal trends in spatial patterns of wildlife crop-raiding have been found. Variations in wildlife ecology and movements, and human spatial use have been identified as causes of this apparent unpredictability. However, varying spatial patterns of spatial autocorrelation (SA) in human-wildlife conflict (HWC) data could also contribute. We explicitly explore the effects of SA on wildlife crop-raiding data in order to facilitate the design of future HWC studies. We conducted a comparative survey of raided and nonraided fields to determine key drivers of crop-raiding. Data were subsampled at different spatial scales to select independent raiding data points. The model derived from all data was fitted to subsample data sets. Model parameters from these models were compared to determine the effect of SA. Most methods used to account for SA in data attempt to correct for the change in P-values; yet, by subsampling data at broader spatial scales, we identified changes in regression estimates. We consequently advocate reporting both model parameters across a range of spatial scales to help biological interpretation. Patterns of SA vary spatially in our crop-raiding data. Spatial distribution of fields should therefore be considered when choosing the spatial scale for analyses of HWC studies. Robust key drivers of elephant crop-raiding included raiding history of a field and distance of field to a main elephant pathway. Understanding spatial patterns and determining reliable socio-ecological drivers of wildlife crop-raiding is paramount for designing mitigation and land-use planning strategies to reduce HWC. Spatial patterns of HWC are complex, determined by multiple factors acting at more than one scale; therefore, studies need to be designed with an understanding of the effects of SA. Our methods are accessible to a variety of practitioners to assess the effects of SA, thereby improving the reliability of conservation management actions.
Setalaphruk, Chantita; Price, Lisa Leimar
2007-01-01
Consuming wild foods is part of the food ways of people in many societies, including farming populations throughout the world. Knowledge of non-domesticated food resources is part of traditional and tacit ecological knowledge, and is largely transmitted through socialization within cultural and household contexts. The context of this study, a small village in Northeast Thailand, is one where the community has experienced changes due to the migration of the parental generation, with the children being left behind in the village to be raised by their grandparents. A case study approach was used in order to gain holistic in-depth insight into children's traditional ecological knowledge as well as patterns of how children acquire their knowledge regarding wild food resources. Techniques used during field data collection are free-listing conducted with 30 village children and the use of a sub-sample of children for more in-depth research. For the sub-sample part of the study, wild food items consisted of a selection of 20 wild food species consisting of 10 species of plants and 10 species of animals. Semi-structured interviews with photo identification, informal interviews and participatory observation were utilized, and both theoretical and practical knowledge scored. The sub-sample covers eight households with boys and girls aged between 10–12 years old from both migrant families and non-migrant families. The knowledge of children was compared and the transmission process was observed. The result of our study shows that there is no observable difference among children who are being raised by grandparents and those being raised by their parents, as there are different channels of knowledge transmission to be taken into consideration, particularly grandparents and peers. The basic ability (knowledge) for naming wild food species remains among village children. However, the practical in-depth knowledge, especially about wild food plants, shows some potential eroding. PMID:17937791
47 CFR 1.1602 - Designation for random selection.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 47 Telecommunication 1 2010-10-01 2010-10-01 false Designation for random selection. 1.1602 Section 1.1602 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1602 Designation for random selection...
47 CFR 1.1602 - Designation for random selection.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 1 2011-10-01 2011-10-01 false Designation for random selection. 1.1602 Section 1.1602 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1602 Designation for random selection...
47 CFR 1.1603 - Conduct of random selection.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 47 Telecommunication 1 2010-10-01 2010-10-01 false Conduct of random selection. 1.1603 Section 1.1603 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1603 Conduct of random selection. The...
47 CFR 1.1603 - Conduct of random selection.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 1 2011-10-01 2011-10-01 false Conduct of random selection. 1.1603 Section 1.1603 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1603 Conduct of random selection. The...
ATLASGAL - towards a complete sample of massive star forming clumps
NASA Astrophysics Data System (ADS)
Urquhart, J. S.; Moore, T. J. T.; Csengeri, T.; Wyrowski, F.; Schuller, F.; Hoare, M. G.; Lumsden, S. L.; Mottram, J. C.; Thompson, M. A.; Menten, K. M.; Walmsley, C. M.; Bronfman, L.; Pfalzner, S.; König, C.; Wienen, M.
2014-09-01
By matching infrared-selected, massive young stellar objects (MYSOs) and compact H II regions in the Red MSX Source survey to massive clumps found in the submillimetre ATLASGAL (APEX Telescope Large Area Survey of the Galaxy) survey, we have identified ˜1000 embedded young massive stars between 280° < ℓ < 350° and 10° < ℓ < 60° with | b | < 1.5°. Combined with an existing sample of radio-selected methanol masers and compact H II regions, the result is a catalogue of ˜1700 massive stars embedded within ˜1300 clumps located across the inner Galaxy, containing three observationally distinct subsamples, methanol-maser, MYSO and H II-region associations, covering the most important tracers of massive star formation, thought to represent key stages of evolution. We find that massive star formation is strongly correlated with the regions of highest column density in spherical, centrally condensed clumps. We find no significant differences between the three samples in clump structure or the relative location of the embedded stars, which suggests that the structure of a clump is set before the onset of star formation, and changes little as the embedded object evolves towards the main sequence. There is a strong linear correlation between clump mass and bolometric luminosity, with the most massive stars forming in the most massive clumps. We find that the MYSO and H II-region subsamples are likely to cover a similar range of evolutionary stages and that the majority are near the end of their main accretion phase. We find few infrared-bright MYSOs associated with the most massive clumps, probably due to very short pre-main-sequence lifetimes in the most luminous sources.
Renner, Walter; Laireiter, Anton-Rupert; Maier, Marco J
2012-01-01
N = 63 refugees and asylum seekers, 27 women and 36 men with a mean age of 33.08 years (SD = 10.3) from Chechnya and Afghanistan were granted sponsorships for six months and were randomized to an intervention and a waiting-list control group. Only participants with a history of traumatization benefited from the intervention. For the traumatized sub-sample, sponsorships led to a significant and stable decrease in anxiety, depression, and psychological problems as compared to the control group, with effect sizes comparable to those of psychotherapy. The effects being rather palliative than instrumental, however, sponsorships did not instigate improvements in acculturation, societal contact, or coping capability. Women benefited more from the intervention than men, and Afghans more than Chechen.
Renner, Walter; Laireiter, Anton-Rupert; Maier, Marco J.
2011-01-01
N = 63 refugees and asylum seekers, 27 women and 36 men with a mean age of 33.08 years (SD = 10.3) from Chechnya and Afghanistan were granted sponsorships for six months and were randomized to an intervention and a waiting-list control group. Only participants with a history of traumatization benefited from the intervention. For the traumatized sub-sample, sponsorships led to a significant and stable decrease in anxiety, depression, and psychological problems as compared to the control group, with effect sizes comparable to those of psychotherapy. The effects being rather palliative than instrumental, however, sponsorships did not instigate improvements in acculturation, societal contact, or coping capability. Women benefited more from the intervention than men, and Afghans more than Chechen. PMID:22318290
Use of Thematic Mapper for water quality assessment
NASA Technical Reports Server (NTRS)
Horn, E. M.; Morrissey, L. A.
1984-01-01
The evaluation of simulated TM data obtained on an ER-2 aircraft at twenty-five predesignated sample sites for mapping water quality factors such as conductivity, pH, suspended solids, turbidity, temperature, and depth, is discussed. Using a multiple regression for the seven TM bands, an equation is developed for the suspended solids. TM bands 1, 2, 3, 4, and 6 are used with logarithm conductivity in a multiple regression. The assessment of regression equations for a high coefficient of determination (R-squared) and statistical significance is considered. Confidence intervals about the mean regression point are calculated in order to assess the robustness of the regressions used for mapping conductivity, turbidity, and suspended solids, and by regressing random subsamples of sites and comparing the resultant range of R-squared, cross validation is conducted.
DiPerna, James Clyde; Lei, Puiwa; Bellinger, Jillian; Cheng, Weiyi
2015-03-01
A multisite cluster randomized trial was conducted to examine the effects of the Social Skills Improvement System Classwide Intervention Program (SSIS-CIP; Elliott & Gresham, 2007) on students' classroom social behavior. The final sample included 432 students across 38 second grade classrooms. Social skills and problem behaviors were measured via the SSIS rating scale for all participants, and direct observations were completed for a subsample of participants within each classroom. Results indicated that the SSIS-CIP demonstrated positive effects on teacher ratings of participants' social skills and internalizing behaviors, with the greatest changes occurring in classrooms with students who exhibited lower skill proficiency prior to implementation. Statistically significant differences were not observed between treatment and control participants on teacher ratings of externalizing problem behaviors or direct observation.
Brown, Jamie; Michie, Susan; Geraghty, Adam W A; Yardley, Lucy; Gardner, Benjamin; Shahab, Lion; Stapleton, John A; West, Robert
2014-12-01
Internet-based interventions for smoking cessation could help millions of people stop smoking at very low unit costs; however, long-term biochemically verified evidence is scarce and such interventions might be less effective for smokers with low socioeconomic status than for those with high status because of lower online literacy to engage with websites. We aimed to assess a new interactive internet-based intervention (StopAdvisor) for smoking cessation that was designed with particular attention directed to people with low socioeconomic status. We did this online randomised controlled trial between Dec 6, 2011, and Oct 11, 2013, in the UK. Participants aged 18 years and older who smoked every day were randomly assigned (1:1) to receive treatment with StopAdvisor or an information-only website. Randomisation was automated with an unseen random number function embedded in the website to establish which treatment was revealed after the online baseline assessment. Recruitment continued until the required sample size had been achieved from both high and low socioeconomic status subpopulations. Participants, and researchers who obtained data and did laboratory analyses, were masked to treatment allocation. The primary outcome was 6 month sustained, biochemically verified abstinence. The main secondary outcome was 6 month, 7 day biochemically verified point prevalence. Analysis was by intention to treat. Homogeneity of intervention effect across the socioeconomic subsamples was first assessed to establish whether overall or separate subsample analyses were appropriate. The study is registered as an International Standard Randomised Controlled Trial, number ISRCTN99820519. We randomly assigned 4613 participants to the StopAdvisor group (n=2321) or the control group (n=2292); 2142 participants were of low socioeconomic status and 2471 participants were of high status. The overall rate of smoking cessation was similar between participants in the StopAdvisor and control groups for the primary (237 [10%] vs 220 [10%] participants; relative risk [RR] 1·06, 95% CI 0·89-1·27; p=0·49) and the secondary (358 [15%] vs 332 [15%] participants; 1·06, 0·93-1·22; p=0·37) outcomes; however, the intervention effect differed across socioeconomic status subsamples (1·44, 0·99-2·09; p=0·0562 and 1·37, 1·02-1·84; p=0·0360, respectively). StopAdvisor helped participants with low socioeconomic status stop smoking compared with the information-only website (primary outcome: 90 [8%] of 1088 vs 64 [6%] of 1054 participants; RR 1·36, 95% CI 1·00-1·86; p=0·0499; secondary outcome: 136 [13%] vs 100 [10%] participants; 1·32, 1·03-1·68, p=0·0267), but did not improve cessation rates in those with high socioeconomic status (147 [12%] of 1233 vs 156 [13%] of 1238 participants; 0·95, 0·77-1·17; p=0·61 and 222 [18%] vs 232 [19%] participants; 0·96, 0·81-1·13, p=0·64, respectively). StopAdvisor was more effective than an information-only website in smokers of low, but not high, socioeconomic status. StopAdvisor could be implemented easily and made freely available, which would probably improve the success rates of smokers with low socioeconomic status who are seeking online support. National Prevention Research Initiative. Copyright © 2014 Brown et al. Open Access article distributed under the terms of CC BY. Published by .. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sehgal, Neelima; Hlozek, Renee; Addison, Graeme
We present the measured Sunyaev-Zel'dovich (SZ) flux from 474 optically selected MaxBCG clusters that fall within the Atacama Cosmology Telescope (ACT) Equatorial survey region. The ACT Equatorial region used in this analysis covers 510 deg{sup 2} and overlaps Stripe 82 of the Sloan Digital Sky Survey. We also present the measured SZ flux stacked on 52 X-ray-selected MCXC clusters that fall within the ACT Equatorial region and an ACT Southern survey region covering 455 deg{sup 2}. We find that the measured SZ flux from the X-ray-selected clusters is consistent with expectations. However, we find that the measured SZ flux frommore » the optically selected clusters is both significantly lower than expectations and lower than the recovered SZ flux measured by the Planck satellite. Since we find a lower recovered SZ signal than Planck, we investigate the possibility that there is a significant offset between the optically selected brightest cluster galaxies (BCGs) and the SZ centers, to which ACT is more sensitive due to its finer resolution. Such offsets can arise due to either an intrinsic physical separation between the BCG and the center of the gas concentration or from misidentification of the cluster BCG. We find that the entire discrepancy for both ACT and Planck can be explained by assuming that the BCGs are offset from the SZ maxima with a uniform random distribution between 0 and 1.5 Mpc. Such large offsets between gas peaks and BCGs for optically selected cluster samples seem unlikely given that we find the physical separation between BCGs and X-ray peaks for an X-ray-selected subsample of MaxBCG clusters to have a much narrower distribution that peaks within 0.2 Mpc. It is possible that other effects are lowering the ACT and Planck signals by the same amount, with offsets between BCGs and SZ peaks explaining the remaining difference between ACT and Planck measurements. Several effects that can lower the SZ signal equally for both ACT and Planck, but not explain the difference in measured signals, include a larger percentage of false detections in the MaxBCG sample, a lower normalization of the mass-richness relation, radio or infrared galaxy contamination of the SZ flux, and a low intrinsic SZ signal. In the latter two cases, the effects would need to be preferentially more significant in the optically selected MaxBCG sample than in the MCXC X-ray sample.« less
A Weighted Least Squares Approach To Robustify Least Squares Estimates.
ERIC Educational Resources Information Center
Lin, Chowhong; Davenport, Ernest C., Jr.
This study developed a robust linear regression technique based on the idea of weighted least squares. In this technique, a subsample of the full data of interest is drawn, based on a measure of distance, and an initial set of regression coefficients is calculated. The rest of the data points are then taken into the subsample, one after another,…
Fundamental techniques for resolution enhancement of average subsampled images
NASA Astrophysics Data System (ADS)
Shen, Day-Fann; Chiu, Chui-Wen
2012-07-01
Although single image resolution enhancement, otherwise known as super-resolution, is widely regarded as an ill-posed inverse problem, we re-examine the fundamental relationship between a high-resolution (HR) image acquisition module and its low-resolution (LR) counterpart. Analysis shows that partial HR information is attenuated but still exists, in its LR version, through the fundamental averaging-and-subsampling process. As a result, we propose a modified Laplacian filter (MLF) and an intensity correction process (ICP) as the pre and post process, respectively, with an interpolation algorithm to partially restore the attenuated information in a super-resolution (SR) enhanced image image. Experiments show that the proposed MLF and ICP provide significant and consistent quality improvements on all 10 test images with three well known interpolation methods including bilinear, bi-cubic, and the SR graphical user interface program provided by Ecole Polytechnique Federale de Lausanne. The proposed MLF and ICP are simple in implementation and generally applicable to all average-subsampled LR images. MLF and ICP, separately or together, can be integrated into most interpolation methods that attempt to restore the original HR contents. Finally, the idea of MLF and ICP can also be applied for average, subsampled one-dimensional signal.
An approach to unbiased subsample interpolation for motion tracking.
McCormick, Matthew M; Varghese, Tomy
2013-04-01
Accurate subsample displacement estimation is necessary for ultrasound elastography because of the small deformations that occur and the subsequent application of a derivative operation on local displacements. Many of the commonly used subsample estimation techniques introduce significant bias errors. This article addresses a reduced bias approach to subsample displacement estimations that consists of a two-dimensional windowed-sinc interpolation with numerical optimization. It is shown that a Welch or Lanczos window with a Nelder-Mead simplex or regular-step gradient-descent optimization is well suited for this purpose. Little improvement results from a sinc window radius greater than four data samples. The strain signal-to-noise ratio (SNR) obtained in a uniformly elastic phantom is compared with other parabolic and cosine interpolation methods; it is found that the strain SNR ratio is improved over parabolic interpolation from 11.0 to 13.6 in the axial direction and 0.7 to 1.1 in the lateral direction for an applied 1% axial deformation. The improvement was most significant for small strains and displacement tracking in the lateral direction. This approach does not rely on special properties of the image or similarity function, which is demonstrated by its effectiveness with the application of a previously described regularization technique.
NASA Astrophysics Data System (ADS)
Bentes, Sonia R.
2016-02-01
This paper examines the long memory behavior in the volatility of gold returns using daily data for the period 1985-2009. We divided the whole sample into eight sub-samples in order to analyze the robustness and consistency of our results during different crisis periods. This constitutes our main contribution. We cover four major world crises, namely, (i) the US stock market crash of 1987; (ii) the Asian financial crisis of 1997; (iii) the World Trade Center terrorist attack of 2001 and finally, (iv) the sub-prime crisis of 2007, in order to investigate how the fractional integrated parameter of the FIGARCH(1, d,1) model evolves over time. Our findings are twofold: (i) there is evidence of long memory in the conditional variance over the whole sample period; (ii) when we consider the sub-sample analysis, the results show mixed evidence. Thus, for the 1985-2003 period the long memory parameter is positive and statistically significant in the pre-crisis sub-samples, and there is no evidence of long memory in the crisis sub-sample periods; however the reverse pattern occurs for the 2005-2009 period. This highlights the unique characteristics of the 2007 sub-prime crisis.
Aslan, Alper; Destek, Mehmet Akif; Okumus, Ilyas
2018-01-01
This study aims to examine the validity of inverted U-shaped Environmental Kuznets Curve by investigating the relationship between economic growth and environmental pollution for the period from 1966 to 2013 in the USA. Previous studies based on the assumption of parameter stability and obtained parameters do not change over the full sample. This study uses bootstrap rolling window estimation method to detect the possible changes in causal relations and also obtain the parameters for sub-sample periods. The results show that the parameter of economic growth has increasing trend in 1982-1996 sub-sample periods, and it has decreasing trend in 1996-2013 sub-sample periods. Therefore, the existence of inverted U-shaped Environmental Kuznets Curve is confirmed in the USA.
Selecting AGN through Variability in SN Datasets
NASA Astrophysics Data System (ADS)
Boutsia, K.; Leibundgut, B.; Trevese, D.; Vagnetti, F.
2010-07-01
Variability is a main property of Active Galactic Nuclei (AGN) and it was adopted as a selection criterion using multi epoch surveys conducted for the detection of supernovae (SNe). We have used two SN datasets. First we selected the AXAF field of the STRESS project, centered in the Chandra Deep Field South where, besides the deep X-ray surveys also various optical catalogs exist. Our method yielded 132 variable AGN candidates. We then extended our method including the dataset of the ESSENCE project that has been active for 6 years, producing high quality light curves in the R and I bands. We obtained a sample of ˜4800 variable sources, down to R=22, in the whole 12 deg2 ESSENCE field. Among them, a subsample of ˜500 high priority AGN candidates was created using as secondary criterion the shape of the structure function. In a pilot spectroscopic run we have confirmed the AGN nature for nearly all of our candidates.
Awareness of HIV/AIDS and household environment of pregnant women in Pune, India.
Shrotri, A; Shankar, A V; Sutar, S; Joshi, A; Suryawanshi, N; Pisal, H; Bharucha, K E; Phadke, M A; Bollinger, R C; Sastry, J
2003-12-01
Our objective was to determine the level of HIV/AIDS knowledge of pregnant women in India. In a sub-sample of these women, we documented the extent to which they experienced adverse social and physical difficulties within their home. The study was performed at an urban antenatal hospital clinic in Maharastra, India. From April to September 2001, structured interviews were conducted on 707 randomly selected antenatal clinic patients related to HIV/AIDS knowledge. Of these, 283 were further interviewed to document any social or physical difficulties they experienced. Over 75% of women displayed knowledge of primary transmission routes. Nearly 70% of women demonstrated knowledge of maternal to child transmission, however, only 8% knew of any methods of prevention. TV and written material were more strongly related to knowledge than access to radio messages or conversations with individuals. Thirty per cent of the women experienced physical or mental abuse or their spouse's alcohol and/or drug problems. Women reporting such abuse were more than twice as likely to have adequate HIV/AIDS knowledge compared with women reporting no such abuse. We found no relationship between reported household abuse and educational level of woman, husband, occupation of either partner, language or religion. We found no relationship between HIV status and knowledge of HIV and no relationship between HIV status and risk of abuse in the household. However, the total number of HIV patients in our sample was very small.
Hancock, M; Calnan, M; Manley, G
1999-12-01
Recent changes in the NHS General Dental Service have led to a reduction in the availability of NHS dental care and increased charges. This study explores public and user views and experiences of NHS and private dental care in the light of these changes. The study employed a combination of quantitative and qualitative methods. The first phase involved a postal survey of a random sample of adults on the electoral registers in a county in Southern England, which yielded a response rate of 55 per cent (n = 1506). Follow-up face-to-face interviews were carried out with sub-samples (n = 50) selected from survey respondents. The evidence shows greater satisfaction with certain aspects of private care than with NHS dental care and suggests that the decline in perceived quality of NHS care is less to do with the quality of dental technical skills and more to do with perceived access and availability. However, there was general support for the egalitarian principles associated with NHS dentistry, although payment for dental care by users was acceptable even though dentistry on the NHS was preferred. The shift in the balance of NHS and private dental care reflects the interests and preferences of dentists rather than of the public. It suggests, however, that a continued shift towards private practice is a trend that the public will not find acceptable, which might limit the extent of expansion of private practice.
Boersen, Mark R.; Clark, Joseph D.; King, Tim L.
2003-01-01
The Recovery Plan for the federally threatened Louisiana black bear (Ursus americanus luteolus) mandates that remnant populations be estimated and monitored. In 1999 we obtained genetic material with barbed-wire hair traps to estimate bear population size and genetic diversity at the 329-km2 Tensas River Tract, Louisiana. We constructed and monitored 122 hair traps, which produced 1,939 hair samples. Of those, we randomly selected 116 subsamples for genetic analysis and used up to 12 microsatellite DNA markers to obtain multilocus genotypes for 58 individuals. We used Program CAPTURE to compute estimates of population size using multiple mark-recapture models. The area of study was almost entirely circumscribed by agricultural land, thus the population was geographically closed. Also, study-area boundaries were biologically discreet, enabling us to accurately estimate population density. Using model Chao Mh to account for possible effects of individual heterogeneity in capture probabilities, we estimated the population size to be 119 (SE=29.4) bears, or 0.36 bears/km2. We were forced to examine a substantial number of loci to differentiate between some individuals because of low genetic variation. Despite the probable introduction of genes from Minnesota bears in the 1960s, the isolated population at Tensas exhibited characteristics consistent with inbreeding and genetic drift. Consequently, the effective population size at Tensas may be as few as 32, which warrants continued monitoring or possibly genetic augmentation.
Acute respiratory diseases and carboxyhemoglobin status in school children of Quito, Ecuador.
Estrella, Bertha; Estrella, Ramiro; Oviedo, Jorge; Narváez, Ximena; Reyes, María T; Gutiérrez, Miguel; Naumova, Elena N
2005-05-01
Outdoor carbon monoxide comes mainly from vehicular emissions, and high concentrations occur in areas with heavy traffic congestion. CO binds to hemoglobin, forming carboxyhemoglobin (COHb), and reduces oxygen delivery. We investigated the link between the adverse effects of CO on the respiratory system using COHb as a marker for chronic CO exposure. We examined the relationship between acute respiratory infections (ARIs) and COHb concentrations in school-age children living in urban and suburban areas of Quito, Ecuador. We selected three schools located in areas with different traffic intensities and enrolled 960 children. To adjust for potential confounders we conducted a detailed survey. In a random subsample of 295 children, we determined that average COHb concentrations were significantly higher in children attending schools in areas with high and moderate traffic, compared with the low-traffic area. The percentage of children with COHb concentrations above the safe level of 2.5% were 1, 43, and 92% in low-, moderate-, and high-traffic areas, respectively. Children with COHb above the safe level are 3.25 [95% confidence interval (CI), 1.65-6.38] times more likely to have ARI than children with COHb < 2.5%. Furthermore, with each percent increase in COHb above the safety level, children are 1.15 (95% CI, 1.03-1.28) times more likely to have an additional case of ARI. Our findings provide strong evidence of the relation between CO exposure and susceptibility to respiratory infections.
Prinsloo, Catharina Dorothea; Greeff, Minrie; Kruger, Annamarie; Khumalo, Itumeleng Paul
2017-09-01
This study sought to explore, describe and determine whether an HIV stigma-reduction community "hub" intervention would change the HIV stigma experiences of people living with HIV (PLWH) and the stigmatisation by the community in an urban area in South Africa. A convergent parallel mixed-method design with a single case pre-test post-test design and an interpretive description approach was utilised. The sample for this study included 62 PLWH recruited through accessibility sampling and 570 community members recruited through random voluntary sampling. A sub-sample of both groups, selected using purposive voluntary sampling, was utilised for the in-depth interviews about stigma experiences of PLWH, and for perceptions and attitudes of the community toward PLWH. Both quantitative and qualitative data showed that stigma is present. Although no statistically significant changes were found, small practically significant changes were demonstrated in the experiences of PLWH and in the perceptions and attitudes of the community. The extent of changes was much more obvious in the responses of the PLWH and the community during their post-intervention qualitative interviews than the changes found with the quantitative measures. This study thus concludes that the HIV stigma-reduction community hub intervention was successful in initiating the onset of changes in a community through the PLWH and people living close to PLWH (PLC) as community mobilisers active in the community hub to mobilise their own communities towards HIV stigma reduction through social change.
Descriptive analysis of the Test of Everyday Attention for Children in a Spanish Normative Sample.
Pardos, Alexandra; Quintero, Javier; Zuluaga, Pilar; Fernández, Alberto
2016-09-01
Test of Everyday Attention for Children (TEA-Ch) has been validated in different countries demonstrating that it is an instrument with a correct balance between reliability and duration. Given the shortage of trustworthy instruments of evaluation in our language for infantile population we decide to explore the Spanish version of the TEA-Ch. We administered TEA-Ch (version A) to a sample control of 133 Spanish children from 6 to 11 years enrolled in school in the Community of Madrid. Four children were selected at random by course of Primary Education, distributing the sex of equivalent form. Descriptive analysis and comparison by ages and sex in each of the TEA-Ch´s subtests were conducted to establish a profile of the sample. In order to analyze the effect of the age, subjects were grouped in six sub-samples: 6, 7, 8, 9, 10 and 11 years-old. This first descriptive analysis demonstrates age exerted a significant effect on each measure, due to an important “jump” in children´s performance between 6 and 7 years-old. The effect of sex was significant only in two visual attention measures (Sky Search & Map) and interaction age and sex exerted a significant effect only in the dual task (Score DT). The results suggest that the Spanish version of the TEA-Ch (A) might be a useful instrument to evaluate attentional processes in Spanish child population.
Measurement of sexual identity in surveys: implications for substance abuse research.
McCabe, Sean Esteban; Hughes, Tonda L; Bostwick, Wendy; Morales, Michele; Boyd, Carol J
2012-06-01
Researchers are increasingly recognizing the need to include measures of sexual orientation in health studies. However, relatively little attention has been paid to how sexual identity, the cognitive aspect of sexual orientation, is defined and measured. Our study examined the impact of using two separate sexual identity question formats: a three-category question (response options included heterosexual, bisexual, or lesbian/gay), and a similar question with five response options (only lesbian/gay, mostly lesbian/gay, bisexual, mostly heterosexual, only heterosexual). A large probability-based sample of undergraduate university students was surveyed and a randomly selected subsample of participants was asked both sexual identity questions. Approximately one-third of students who identified as bisexual based on the three-category sexual identity measure chose "mostly heterosexual" or "mostly lesbian/gay" on the five-category measure. In addition to comparing sample proportions of lesbian/gay, bisexual, or heterosexual participants based on the two question formats, rates of alcohol and other drug use were also examined among the participants. Substance use outcomes among the sexual minority subgroups differed based on the sexual identity question format used: bisexual participants showed greater risk of substance use in analyses using the three-category measure whereas "mostly heterosexual" participants were at greater risk when data were analyzed using the five-category measure. Study results have important implications for the study of sexual identity, as well as whether and how to recode responses to questions related to sexual identity.
Perception of dental appearance using Index of Treatment Need (Aesthetic Component) assessments.
Abdullah, M S B; Rock, W P
2002-09-01
To compare assessments of malocclusion made by an orthodontist with the perceptions of children and their parents. A sample of 5,112 Malaysian schoolchildren was selected by a system of stratified random sampling based on state, ethnicity and gender. Each child was first allocated an IOTN (AC) grade by an orthodontist, after which the child and then the parents also recorded a grade. A smaller sub-sample of 720 children was also asked to identify the three worst AC pictures and to give reasons for their choice. The orthodontist scored 22.8% of the subjects in AC grades 8-10, 'Definite Need for Treatment' whilst only 5.8% of children and 4.8% of parents recorded these grades. If AC grade 6 is taken as the cut off point the proportions needing treatment would be 41.8%, 9.7% and 9.9% respectively. Similar proportions of boys and girls scored their own teeth in the 8-10 range but more girls than boys scored themselves in grades 1-3, 'No Need for Treatment'. Ethnic origin had no effect upon the perception of malocclusion by the children. Crowding, deep bite and tooth size were the three occlusal features that children liked least. The IOTN (AC) index appears robust in its reflection of the perception of malocclusion by children and parents respectively. Assessments were little affected by gender or ethnicity. However the scores of children and parents were much lower than those of an orthodontist trained in the use of IOTN.
Acute Respiratory Diseases and Carboxyhemoglobin Status in School Children of Quito, Ecuador
Estrella, Bertha; Estrella, Ramiro; Oviedo, Jorge; Narváez, Ximena; Reyes, María T.; Gutiérrez, Miguel; Naumova, Elena N.
2005-01-01
Outdoor carbon monoxide comes mainly from vehicular emissions, and high concentrations occur in areas with heavy traffic congestion. CO binds to hemoglobin, forming carboxyhemoglobin (COHb), and reduces oxygen delivery. We investigated the link between the adverse effects of CO on the respiratory system using COHb as a marker for chronic CO exposure. We examined the relationship between acute respiratory infections (ARIs) and COHb concentrations in school-age children living in urban and suburban areas of Quito, Ecuador. We selected three schools located in areas with different traffic intensities and enrolled 960 children. To adjust for potential confounders we conducted a detailed survey. In a random subsample of 295 children, we determined that average COHb concentrations were significantly higher in children attending schools in areas with high and moderate traffic, compared with the low-traffic area. The percentage of children with COHb concentrations above the safe level of 2.5% were 1, 43, and 92% in low-, moderate-, and high-traffic areas, respectively. Children with COHb above the safe level are 3.25 [95% confidence interval (CI), 1.65–6.38] times more likely to have ARI than children with COHb < 2.5%. Furthermore, with each percent increase in COHb above the safety level, children are 1.15 (95% CI, 1.03–1.28) times more likely to have an additional case of ARI. Our findings provide strong evidence of the relation between CO exposure and susceptibility to respiratory infections. PMID:15866771
Walsh, Raoul A; Tzelepis, Flora; Stojanovski, Elizabeth
2008-03-01
There has been no systematic examination of issues surrounding pension funds and their tobacco shareholdings. This paper describes two studies designed to document the tobacco investment policies and practices of pension funds, and to assess community and fund member attitudes to pension fund shareholdings in the tobacco industry. Chief executives (n = 282) of Australian pension funds were mailed questionnaires. Of 241 eligible funds, 107 (44.4%) returned questionnaires, representing about 61% of total Australian primary superannuation accounts. Twelve percent indicated that they did not currently hold tobacco investments, 30% held tobacco shares and 58% did not know or failed to answer. Overall, 6% of respondents said that they held no tobacco investments and would not consider future investments; 2% had formal policies precluding tobacco investments. Funds with 10,000 or more members were more likely (p = 0.0006) to report tobacco investments. External fund manager advice was the most important factor influencing the funds' position. In the second study, a one-third random sub-sample of consenting subjects from 12,000 households randomly selected from the New South Wales Electronic White Pages completed phone interviews. From 7141 eligible households, 3503 (49.1%) subjects consented. One-third (n = 1158) were asked the pension fund questions. Over three-quarters (77.4%) of all respondents disagreed that pension fund investments in tobacco were ethical. Approximately two-thirds (63.6%) of fund members (n = 852) agreed that their funds should not make tobacco investments. There were three statistically significant predictors of opposition to such investments: being female, more highly educated and non-smoking status. Nearly all pension funds treat tobacco investments like any other investment. In contrast, most of the public including fund members are strongly opposed to such investments. Suggestions for public health advocacy strategies to reduce the negative health promotion effects of pension funds in this area are outlined.
Nonfermented milk and other dairy products: associations with all-cause mortality.
Tognon, Gianluca; Nilsson, Lena M; Shungin, Dmitry; Lissner, Lauren; Jansson, Jan-Håkan; Renström, Frida; Wennberg, Maria; Winkvist, Anna; Johansson, Ingegerd
2017-06-01
Background: A positive association between nonfermented milk intake and increased all-cause mortality was recently reported, but overall, the association between dairy intake and mortality is inconclusive. Objective: We studied associations between intake of dairy products and all-cause mortality with an emphasis on nonfermented milk and fat content. Design: A total of 103,256 adult participants (women: 51.0%) from Northern Sweden were included (7121 deaths; mean follow-up: 13.7 y). Associations between all-cause mortality and reported intakes of nonfermented milk (total or by fat content), fermented milk, cheese, and butter were tested with the use of Cox proportional hazards models that were adjusted for age, sex, body mass index, smoking status, education, energy intake, examination year, and physical activity. To circumvent confounding, Mendelian randomization was applied in a subsample via the lactase LCT - 13910 C/T single nucleotide polymorphism that is associated with lactose tolerance and milk intake. Results: High consumers of nonfermented milk (≥2.5 times/d) had a 32% increased hazard (HR: 1.32; 95% CI: 1.18, 1.48) for all-cause mortality compared with that of subjects who consumed milk ≤1 time/wk. The corresponding value for butter was 11% (HR: 1.11; 95% CI: 1.07, 1.21). All nonfermented milk-fat types were independently associated with increased HRs, but compared with full-fat milk, HRs were lower in consumers of medium- and low-fat milk. Fermented milk intake (HR: 0.90; 95% CI: 0.86, 0.94) and cheese intake (HR: 0.93; 95% CI: 0.91, 0.96) were negatively associated with mortality. Results were slightly attenuated by lifestyle adjustments but were robust in sensitivity analyses. Mortality was not significantly associated with the LCT -13910 C/T genotype in the smaller subsample. The amount and type of milk intake was associated with lifestyle variables. Conclusions: In the present Swedish cohort study, intakes of nonfermented milk and butter are associated with higher all-cause mortality, and fermented milk and cheese intakes are associated with lower all-cause mortality. Residual confounding by lifestyle cannot be excluded, and Mendelian randomization needs to be examined in a larger sample. © 2017 American Society for Nutrition.
NASA Astrophysics Data System (ADS)
Denz, Cornelia; Dellwig, Thilo; Lembcke, Jan; Tschudi, Theo
1996-02-01
We propose and demonstrate experimentally a method for utilizing a dynamic phase-encoded photorefractive memory to realize parallel optical addition, subtraction, and inversion operations of stored images. The phase-encoded holographic memory is realized in photorefractive BaTiO3, storing eight images using WalshHadamard binary phase codes and an incremental recording procedure. By subsampling the set of reference beams during the recall operation, the selectivity of the phase address is decreased, allowing one to combine images in such a way that different linear combination of the images can be realized at the output of the memory.
ERIC Educational Resources Information Center
Widmer, E. D.; Kempf-Constantin, N.; Robert-Tissot, C.; Lanzi, F.; Carminati, G. Galli
2008-01-01
Using social network methods, this article explores the ways in which individuals with intellectual disability (ID) perceive their family contexts and the social capital that they provide. Based on a subsample of 24 individuals with ID, a subsample of 24 individuals with ID and psychiatric disorders, and a control sample of 24 pre-graduate and…
Ergovaline Stability in Tall Fescue Based on Sample Handling and Storage Methods
NASA Astrophysics Data System (ADS)
Lea, Krista; Smith, Lori; Gaskill, Cynthia; Coleman, Robert; Smith, S.
2014-09-01
Ergovaline is an ergot alkaloid produced by the endophyte Neotyphodium coenophialum (Morgan-Jones and Gams) found in tall fescue (Schedonorus arundinacea (Schreb.) Dumort.) and blamed for a multitude of livestock disorders. Ergovaline is known to be unstable and affected by many variables. The objective of this study was to determine the effect of sample handling and storage on the stability of ergovaline in tall fescue samples. Fresh tall fescue was collected from a horse farm in central Kentucky at three harvest dates and transported on ice to the University of Kentucky Veterinary Diagnostic Laboratory. Plant material was frozen in liquid nitrogen, milled and mixed before being allocated into different sub-samples. Three sub-samples were assigned to each of 14 sample handling or storage treatments. Sample handling included increased heat and UV light to simulate transportation in a vehicle and on ice in a cooler per standard transportation recommendations. Storage conditions included storage at 22oC, 5oC and -20oC for up to 28 days. Each sub-sample was then analyzed for ergovaline concentration using HPLC with fluorescence detection and this experiment was repeated for each harvest date. Sub-samples exposed to UV light and heat lost a significant fraction of ergovaline in 2 hours, while sub-samples stored on ice in a cooler showed no change in ergovaline in 2 hours. All sub-samples stored at 22oC, 5oC and -20oC lost a significant fraction of ergovaline in the first 24 hours of storage. There was little change in ergovaline in the freezer (-20oC) after the first 24 hours up to 28 days of storage but intermittent losses were observed at 22oC and 5oC. To obtain results that most closely represent levels in the field, all samples should be transported on ice to the laboratory immediately after harvest for same day analysis. If immediate testing is not possible, samples should be stored at -20oC until analysis.
The VIMOS Ultra Deep Survey. Luminosity and stellar mass dependence of galaxy clustering at z 3
NASA Astrophysics Data System (ADS)
Durkalec, A.; Le Fèvre, O.; Pollo, A.; Zamorani, G.; Lemaux, B. C.; Garilli, B.; Bardelli, S.; Hathi, N.; Koekemoer, A.; Pforr, J.; Zucca, E.
2018-04-01
We present a study of the dependence of galaxy clustering on luminosity and stellar mass in the redshift range 2 < z < 3.5 using 3236 galaxies with robust spectroscopic redshifts from the VIMOS Ultra Deep Survey (VUDS), covering a total area of 0.92 deg2. We measured the two-point real-space correlation function wp(rp) for four volume-limited subsamples selected by stellar mass and four volume-limited subsamples selected by MUV absolute magnitude. We find that the scale-dependent clustering amplitude r0 significantly increases with increasing luminosity and stellar mass. For the least luminous galaxies (MUV < -19.0), we measured a correlation length r0 = 2.87 ± 0.22 h-1 Mpc and slope γ = 1.59 ± 0.07, while for the most luminous (MUV < -20.2) r0 = 5.35 ± 0.50 h-1 Mpc and γ = 1.92 ± 0.25. These measurements correspond to a strong relative bias between these two subsamples of Δb/b* = 0.43. Fitting a five-parameter halo occupation distribution (HOD) model, we find that the most luminous (MUV < -20.2) and massive (M⋆ > 1010 h-1 M⊙) galaxies occupy the most massive dark matter haloes with ⟨Mh⟩ = 1012.30 h-1 M⊙. Similar to the trends observed at lower redshift, the minimum halo mass Mmin depends on the luminosity and stellar mass of galaxies and grows from Mmin = 109.73 h-1 M⊙ to Mmin = 1011.58 h-1 M⊙ from the faintest to the brightest among our galaxy sample, respectively. We find the difference between these halo masses to be much more pronounced than is observed for local galaxies of similar properties. Moreover, at z 3, we observe that the masses at which a halo hosts, on average, one satellite and one central galaxy is M1 ≈ 4Mmin over all luminosity ranges, which is significantly lower than observed at z 0; this indicates that the halo satellite occupation increases with redshift. The luminosity and stellar mass dependence is also reflected in the measurements of the large-scale galaxy bias, which we model as bg,HOD (>L) = 1.92 + 25.36(L/L*)7.01. We conclude our study with measurements of the stellar-to-halo mass ratio (SHMR). We observe a significant model-observation discrepancy for low-mass galaxies, suggesting a higher than expected star formation efficiency of these galaxies. Based on data obtained with the European Southern Observatory Very Large Telescope, Paranal, Chile, under Large Programme 185.A-0791.
Statistical Inference for Data Adaptive Target Parameters.
Hubbard, Alan E; Kherad-Pajouh, Sara; van der Laan, Mark J
2016-05-01
Consider one observes n i.i.d. copies of a random variable with a probability distribution that is known to be an element of a particular statistical model. In order to define our statistical target we partition the sample in V equal size sub-samples, and use this partitioning to define V splits in an estimation sample (one of the V subsamples) and corresponding complementary parameter-generating sample. For each of the V parameter-generating samples, we apply an algorithm that maps the sample to a statistical target parameter. We define our sample-split data adaptive statistical target parameter as the average of these V-sample specific target parameters. We present an estimator (and corresponding central limit theorem) of this type of data adaptive target parameter. This general methodology for generating data adaptive target parameters is demonstrated with a number of practical examples that highlight new opportunities for statistical learning from data. This new framework provides a rigorous statistical methodology for both exploratory and confirmatory analysis within the same data. Given that more research is becoming "data-driven", the theory developed within this paper provides a new impetus for a greater involvement of statistical inference into problems that are being increasingly addressed by clever, yet ad hoc pattern finding methods. To suggest such potential, and to verify the predictions of the theory, extensive simulation studies, along with a data analysis based on adaptively determined intervention rules are shown and give insight into how to structure such an approach. The results show that the data adaptive target parameter approach provides a general framework and resulting methodology for data-driven science.
Replication RCT of Early Universal Prevention Effects on Young Adult Substance Misuse
Spoth, Richard; Trudeau, Linda; Redmond, Cleve; Shin, Chungyeol
2014-01-01
Objective For many substances, more frequent and problematic use occurs in young adulthood; these types of use are predicted by the timing of initiation during adolescence. We replicated and extended an earlier study examining whether delayed substance initiation during adolescence, resulting from universal preventive interventions implemented in middle school, reduces problematic use in young adulthood. Method Participants were middle school students from 36 Iowa schools randomly assigned to the Strengthening Families Program plus Life Skills Training (SFP 10–14 + LST), LST-only, or a control condition. Self-report questionnaires were collected at 11 time points, including four during young adulthood. The intercept (average level) and rate of change (slope) in young adult frequency measures (drunkenness, alcohol-related problems, cigarettes, and illicit drugs) across ages 19–22 were modeled as outcomes influenced by growth factors describing substance initiation during adolescence. Analyses entailed testing a two-step hierarchical latent growth curve model; models included the effects of baseline risk, intervention condition assignment, and their interaction. Results Analyses showed significant indirect intervention effects on the average levels of all young adult outcomes, through effects on adolescent substance initiation growth factors, along with intervention by risk interaction effects favoring the higher-risk subsample. Additional direct effects on young adult use were observed in some cases. Relative reduction rates were larger for the higher-risk subsample at age 22, ranging from 5.8% to 36.4% on outcomes showing significant intervention effects. Conclusions Universal preventive interventions implemented during early adolescence have the potential to decrease the rates of substance use and associated problems, into young adulthood. PMID:24821095
Thompson, Sanna J.; Bender, Kimberly A.; Lewis, Carol M.; Watkins, Rita
2009-01-01
Purpose Homeless youth are at particularly high risk for teen pregnancy; research indicates as many as 20% of homeless young women become pregnant. These pregnant and homeless teens lack financial resources and adequate health care, resulting in increased risk for low– birth-weight babies and high infant mortality. This study investigated individual and family-level predictors of teen pregnancy among a national sample of runaway/homeless youth in order to better understand the needs of this vulnerable population. Methods Data from the Runaway/Homeless Youth Management Information System (RHY MIS) provided a national sample of youth seeking services at crisis shelters. A sub-sample of pregnant females and a random sub-sample (matched by age) of nonpregnant females comprised the study sample (N= 951). Chi-square and t tests identified differences between pregnant and nonpregnant runaway females; maximum likelihood logistic regression identified individual and family-level predictors of teen pregnancy. Results Teen pregnancy was associated with being an ethnic minority, dropping out of school, being away from home for longer periods of time, having a sexually transmitted disease, and feeling abandoned by one's family. Family factors, such as living in a single parent household and experiencing emotional abuse by one's mother, increased the odds of a teen being pregnant. Conclusions The complex problems associated with pregnant runaway/homeless teens create challenges for short-term shelter services. Suggestions are made for extending shelter services to include referrals and coordination with teen parenting programs and other systems of care. PMID:18639785
De Neve, Jan-Walter; Subramanian, S V
2018-01-01
An estimated 3.1 million children die each year because of undernutrition. Although cross-sectional and longitudinal studies have found a protective association between greater parental education and undernutrition in their children, no randomized trial has identified a causal effect, to our knowledge. Using the 1980 education reform in Zimbabwe as a natural experiment, we estimated the causal effect of additional parental schooling on the probability of anthropometric failure in their children under 5 years of age (ages 3 through 59 months). Analyzing data on 8,243 children from the 1988, 1999, 2005-2006, and 2010-2011 Demographic and Health Surveys, we found no effect of parental schooling on early childhood undernutrition at the national level in Zimbabwe. Among households in the urban and high-wealth-index subsamples, each additional year of maternal schooling led to absolute reductions in the probability of a child's being wasted of 5.2 percentage points (95% confidence interval (CI): -9.3, -1.2) and 3.6 percentage points (95% CI: -6.9, -0.4), respectively. In the subsample of children between the ages of 3 and 23 months, each additional year of paternal schooling increased the probability of a child's being stunted by 9.6 percentage points (95% CI: 1.4, 17.9). Secondary schooling alone may not be enough to improve early childhood nutrition in low-resource settings. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Are low wages risk factors for hypertension?
Du, Juan
2012-01-01
Objective: Socio-economic status (SES) is strongly correlated with hypertension. But SES has several components, including income and correlations in cross-sectional data need not imply SES is a risk factor. This study investigates whether wages—the largest category within income—are risk factors. Methods: We analysed longitudinal, nationally representative US data from four waves (1999, 2001, 2003 and 2005) of the Panel Study of Income Dynamics. The overall sample was restricted to employed persons age 25–65 years, n = 17 295. Separate subsamples were constructed of persons within two age groups (25–44 and 45–65 years) and genders. Hypertension incidence was self-reported based on physician diagnosis. Our study was prospective since data from three base years (1999, 2001, 2003) were used to predict newly diagnosed hypertension for three subsequent years (2001, 2003, 2005). In separate analyses, data from the first base year were used to predict time-to-reporting hypertension. Logistic regressions with random effects and Cox proportional hazards regressions were run. Results: Negative and strongly statistically significant correlations between wages and hypertension were found both in logistic and Cox regressions, especially for subsamples containing the younger age group (25–44 years) and women. Correlations were stronger when three health variables—obesity, subjective measures of health and number of co-morbidities—were excluded from regressions. Doubling the wage was associated with 25–30% lower chances of hypertension for persons aged 25–44 years. Conclusions: The strongest evidence for low wages being risk factors for hypertension among working people were for women and persons aged 25–44 years. PMID:22262559
Are low wages risk factors for hypertension?
Leigh, J Paul; Du, Juan
2012-12-01
Socio-economic status (SES) is strongly correlated with hypertension. But SES has several components, including income and correlations in cross-sectional data need not imply SES is a risk factor. This study investigates whether wages-the largest category within income-are risk factors. We analysed longitudinal, nationally representative US data from four waves (1999, 2001, 2003 and 2005) of the Panel Study of Income Dynamics. The overall sample was restricted to employed persons age 25-65 years, n = 17 295. Separate subsamples were constructed of persons within two age groups (25-44 and 45-65 years) and genders. Hypertension incidence was self-reported based on physician diagnosis. Our study was prospective since data from three base years (1999, 2001, 2003) were used to predict newly diagnosed hypertension for three subsequent years (2001, 2003, 2005). In separate analyses, data from the first base year were used to predict time-to-reporting hypertension. Logistic regressions with random effects and Cox proportional hazards regressions were run. Negative and strongly statistically significant correlations between wages and hypertension were found both in logistic and Cox regressions, especially for subsamples containing the younger age group (25-44 years) and women. Correlations were stronger when three health variables-obesity, subjective measures of health and number of co-morbidities-were excluded from regressions. Doubling the wage was associated with 25-30% lower chances of hypertension for persons aged 25-44 years. The strongest evidence for low wages being risk factors for hypertension among working people were for women and persons aged 25-44 years.
Detectability of Granger causality for subsampled continuous-time neurophysiological processes.
Barnett, Lionel; Seth, Anil K
2017-01-01
Granger causality is well established within the neurosciences for inference of directed functional connectivity from neurophysiological data. These data usually consist of time series which subsample a continuous-time biophysiological process. While it is well known that subsampling can lead to imputation of spurious causal connections where none exist, less is known about the effects of subsampling on the ability to reliably detect causal connections which do exist. We present a theoretical analysis of the effects of subsampling on Granger-causal inference. Neurophysiological processes typically feature signal propagation delays on multiple time scales; accordingly, we base our analysis on a distributed-lag, continuous-time stochastic model, and consider Granger causality in continuous time at finite prediction horizons. Via exact analytical solutions, we identify relationships among sampling frequency, underlying causal time scales and detectability of causalities. We reveal complex interactions between the time scale(s) of neural signal propagation and sampling frequency. We demonstrate that detectability decays exponentially as the sample time interval increases beyond causal delay times, identify detectability "black spots" and "sweet spots", and show that downsampling may potentially improve detectability. We also demonstrate that the invariance of Granger causality under causal, invertible filtering fails at finite prediction horizons, with particular implications for inference of Granger causality from fMRI data. Our analysis emphasises that sampling rates for causal analysis of neurophysiological time series should be informed by domain-specific time scales, and that state-space modelling should be preferred to purely autoregressive modelling. On the basis of a very general model that captures the structure of neurophysiological processes, we are able to help identify confounds, and offer practical insights, for successful detection of causal connectivity from neurophysiological recordings. Copyright © 2016 Elsevier B.V. All rights reserved.
THE SDSS-III BARYON OSCILLATION SPECTROSCOPIC SURVEY: QUASAR TARGET SELECTION FOR DATA RELEASE NINE
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ross, Nicholas P.; Kirkpatrick, Jessica A.; Carithers, William C.
2012-03-01
The SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), a five-year spectroscopic survey of 10,000 deg{sup 2}, achieved first light in late 2009. One of the key goals of BOSS is to measure the signature of baryon acoustic oscillations (BAOs) in the distribution of Ly{alpha} absorption from the spectra of a sample of {approx}150,000 z > 2.2 quasars. Along with measuring the angular diameter distance at z Almost-Equal-To 2.5, BOSS will provide the first direct measurement of the expansion rate of the universe at z > 2. One of the biggest challenges in achieving this goal is an efficient target selection algorithmmore » for quasars in the redshift range 2.2 < z < 3.5, where their colors tend to overlap those of the far more numerous stars. During the first year of the BOSS survey, quasar target selection (QTS) methods were developed and tested to meet the requirement of delivering at least 15 quasars deg{sup -2} in this redshift range, with a goal of 20 out of 40 targets deg{sup -2} allocated to the quasar survey. To achieve these surface densities, the magnitude limit of the quasar targets was set at g {<=} 22.0 or r {<=} 21.85. While detection of the BAO signature in the distribution of Ly{alpha} absorption in quasar spectra does not require a uniform target selection algorithm, many other astrophysical studies do. We have therefore defined a uniformly selected subsample of 20 targets deg{sup -2}, for which the selection efficiency is just over 50% ({approx}10 z > 2.20 quasars deg{sup -2}). This 'CORE' subsample will be fixed for Years Two through Five of the survey. For the remaining 20 targets deg{sup -2}, we will continue to develop improved selection techniques, including the use of additional data sets beyond the Sloan Digital Sky Survey (SDSS) imaging data. In this paper, we describe the evolution and implementation of the BOSS QTS algorithms during the first two years of BOSS operations (through 2011 July), in support of the science investigations based on these data, and we analyze the spectra obtained during the first year. During this year, 11,263 new z > 2.20 quasars were spectroscopically confirmed by BOSS, roughly double the number of previously known quasars with z > 2.20. Our current algorithms select an average of 15 z > 2.20 quasars deg{sup -2} from 40 targets deg{sup -2} using single-epoch SDSS imaging. Multi-epoch optical data and data at other wavelengths can further improve the efficiency and completeness of BOSS QTS.« less
Kizirian, Nathalie V; Kong, Yang; Muirhead, Roslyn; Brodie, Shannon; Garnett, Sarah P; Petocz, Peter; Sim, Kyra A; Celermajer, David S; Louie, Jimmy C Y; Markovic, Tania P; Ross, Glynis P; Ward, Leigh C; Brand-Miller, Jennie C; Skilton, Michael R
2016-04-01
Elevated maternal blood glucose concentrations may contribute to macrosomia, adiposity, and poorer vascular health in the offspring. The aim was to explore the effect of a low-glycemic index (low-GI) diet during pregnancy on offspring growth, adiposity, and arterial wall thickness during infancy. This was a longitudinal follow-up study in a self-selected subgroup of mother-infant pairs (n= 59) participating in a larger randomized trial comparing the effects on perinatal outcomes of a low-GI diet and a conventional high-fiber (HF) diet during pregnancy. Infant anthropometric measurements were taken every month for 6 mo and then at 9 and 12 mo of age. Adiposity was assessed at birth and at 3 mo by air-displacement plethysmography by using the Pea Pod system (Cosmed) and at 6 and 12 mo by bioimpedance analysis (Bodystat). Aortic intima-media thickness was assessed at 12 mo by high-resolution ultrasound (Philips). Maternal dietary GI was lower in the low-GI group than in the HF group (51 ± 1 compared with 57 ± 1;P< 0.001). No differences in neonatal outcomes were observed in the main trial. In the self-selected subsample, birth weight and length z scores were lower in the low-GI group than in the HF group (birth weight z score: 0.2 ± 0.2 compared with 0.7 ± 0.2, respectively;P= 0.04; birth length z score: 0.3 ± 0.2 compared with 0.9 ± 0.2, respectively;P= 0.04), but adiposity from birth to 12 mo of age and growth trajectories from 1 to 12 mo of age were similar. Aortic intima-media thickness was lower in the low-GI group than in the HF group (657 ±12 compared with 696 ± 12 μm, respectively;P= 0.02), which was partly mediated by differences in birth weight. In women at risk of gestational diabetes mellitus, a low-GI diet influences offspring birth weight, birth length, and arterial wall thickness in early childhood, but not adiposity or growth trajectory during the first year of life. This trial was registered at anzctr.org.au as ACTRN12610000681055. © 2016 American Society for Nutrition.
PULSAR SIGNAL DENOISING METHOD BASED ON LAPLACE DISTRIBUTION IN NO-SUBSAMPLING WAVELET PACKET DOMAIN
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wenbo, Wang; Yanchao, Zhao; Xiangli, Wang
2016-11-01
In order to improve the denoising effect of the pulsar signal, a new denoising method is proposed in the no-subsampling wavelet packet domain based on the local Laplace prior model. First, we count the true noise-free pulsar signal’s wavelet packet coefficient distribution characteristics and construct the true signal wavelet packet coefficients’ Laplace probability density function model. Then, we estimate the denosied wavelet packet coefficients by using the noisy pulsar wavelet coefficients based on maximum a posteriori criteria. Finally, we obtain the denoisied pulsar signal through no-subsampling wavelet packet reconstruction of the estimated coefficients. The experimental results show that the proposed method performs better when calculating the pulsar time of arrival than the translation-invariant wavelet denoising method.
ERIC Educational Resources Information Center
Fruhe, Barbara; Allgaier, Antje-Kathrin; Pietsch, Kathrin; Baethmann, Martina; Peters, Jochen; Kellnar, Stephan; Heep, Axel; Burdach, Stefan; von Schweinitz, Dietrich; Schulte-Korne, Gerd
2012-01-01
The aim of the present study was to develop and validate the Children's Depression Screener (ChilD-S) for use in pediatric care. In two pediatric samples, children aged 9-12 (NI = 200; NII = 246) completed an explorative item pool (subsample I) and a revised item pool (subsample II). Diagnostic accuracy of each of the 22 items from the revised…
An Approach to Unbiased Subsample Interpolation for Motion Tracking
McCormick, Matthew M.; Varghese, Tomy
2013-01-01
Accurate subsample displacement estimation is necessary for ultrasound elastography because of the small deformations that occur and the subsequent application of a derivative operation on local displacements. Many of the commonly used subsample estimation techniques introduce significant bias errors. This article addresses a reduced bias approach to subsample displacement estimations that consists of a two-dimensional windowed-sinc interpolation with numerical optimization. It is shown that a Welch or Lanczos window with a Nelder–Mead simplex or regular-step gradient-descent optimization is well suited for this purpose. Little improvement results from a sinc window radius greater than four data samples. The strain signal-to-noise ratio (SNR) obtained in a uniformly elastic phantom is compared with other parabolic and cosine interpolation methods; it is found that the strain SNR ratio is improved over parabolic interpolation from 11.0 to 13.6 in the axial direction and 0.7 to 1.1 in the lateral direction for an applied 1% axial deformation. The improvement was most significant for small strains and displacement tracking in the lateral direction. This approach does not rely on special properties of the image or similarity function, which is demonstrated by its effectiveness with the application of a previously described regularization technique. PMID:23493609
Dávila-Romero, C; Hernández-Mocholí, M A; García-Hermoso, A
2015-03-01
This study is divided into three sequential stages: identification of fitness and game performance profiles (individual player performance), an assessment of the relationship between these profiles, and an assessment of the relationship between individual player profiles and team performance during play (in championship performance). The overall study sample comprised 525 (19 teams) female volleyball players aged 12-16 years and a subsample (N.=43) used to examine study aims one and two was selected from overall sample. Anthropometric, fitness and individual player performance (actual game) data were collected in the subsample. These data were analyzed through clustering methods, ANOVA and independence chi-square test. Then, we investigated whether the proportion of players with the highest individual player performance profile might predict a team's results in the championship. Cluster analysis identified three volleyball fitness profiles (high, medium, and low) and two individual player performance profiles (high and low). The results showed a relationship between both types of profile (fitness and individual player performance). Then, linear regression revealed a moderate relationship between the number of players with a high volleyball fitness profile and a team's results in the championship (R2=0.23). The current study findings may enable coaches and trainers to manage training programs more efficiently in order to obtain tailor-made training, identify volleyball-specific physical fitness training requirements and reach better results during competitions.
Maternal asthma and idiopathic preterm labor.
Kramer, M S; Coates, A L; Michoud, M C; Dagenais, S; Moshonas, D; Davis, G M; Hamilton, E F; Nuwayhid, B; Joshi, A K; Papageorgiou, A
1995-11-15
Previous studies suggest that women with asthma are at increased risk of preterm birth. Moreover, drugs (especially beta-agonists) used to treat asthma are also used to treat preterm labor. The authors carried out a case-control study of 555 women from three hospital centers with idiopathic preterm labor (< 37 weeks), including two overlapping (i.e., non-mutually exclusive) subsamples: cases with early idiopathic preterm labor (< 34 weeks) and cases with idiopathic recurrent preterm labor (< 37 weeks plus a previous history of preterm delivery or second-trimester miscarriage). Controls were matched to cases according to race and smoking history prior to and during pregnancy. All subjects responded in person to questions about atopic, respiratory, obstetric, and sociodemographic histories. Subjects in the early and recurrent preterm labor subsamples were also asked to undergo spirometric testing with methacholine challenge 6-12 weeks after delivery. Cases were significantly more likely to report histories of asthma symptoms and physician-diagnosed asthma (matched odds ratios of 2-3) than controls, particularly those cases with recurrent preterm labor. No significant associations were observed, however, with methacholine responsiveness. These results could not be explained by residual confounding by smoking or other variables, nor by selective recall of asthma symptoms and histories by cases. Women with asthma are at increased risk of idiopathic preterm labor. The fact that no such association was seen with methacholine responsiveness suggests that nonatopic, noncholinergic mechanisms may link bronchial and uterine smooth muscle lability.
Izbicki, John A.; Clark, Dennis A.; Pimental, Maria I.; Land, Michael; Radyk, John C.; Michel, Robert L.
2000-01-01
This report presents data on the physical properties of unsaturated alluvial deposits and on the chemical and isotopic composition of soil water and soil gas collected at 12 monitoring sites in the western part of the Mojave Desert, near Victorville, California. Sites were installed using the ODEX air-hammer method. Seven sites were located in the active channels of Oro Grande and Sheep Creek Washes. The remaining five sites were located away from the active washes. Most sites were drilled to a depth of about 100 feet below land surface; two sites were drilled to the water table almost 650 feet below land surface. Drilling procedures, lithologic and geophysical data, and site construction and instrumentation are described. Core material was analyzed for water content, bulk density, water potential, particle size, and water retention. The chemical composition of leachate from almost 1,000 subsamples of cores and cuttings was determined. Water extracted from selected subsamples of cores was analyzed for tritium and the stable isotopes of oxygen and hydrogen. Water from suction-cup lysimeters and soil-gas samples also were analyzed for chemical and isotopic composition. In addition, data on the chemical and isotopic composition of bulk precipitation from five sites and on ground water from two water-table wells are reported.
Neuroticism and introversion are associated with salivary cortisol patterns in adolescents.
Hauner, Katherina K Y; Adam, Emma K; Mineka, Susan; Doane, Leah D; DeSantis, Amy S; Zinbarg, Richard; Craske, Michelle; Griffith, James W
2008-11-01
Previous studies have yielded equivocal findings on the relationship between personality and cortisol activity. The present study examined associations between personality and cortisol activity in a large, diverse adolescent sample, while partialling the effects of relevant demographic and health-related covariates. A subsample of 230 participants (57% of whom reported elevated neuroticism) was selected from a larger sample of 16-18-year olds involved in a study on risk factors for emotional disorders. Subsample participants completed a battery of personality questionnaires, and saliva collection was requested several months later on three consecutive days at six time points per day, from wakeup to bedtime. Associations between personality and cortisol rhythms were examined using multilevel growth curve modeling. Neuroticism (N) and introversion (I) were significantly and differentially associated with features of diurnal cortisol patterns. Specifically, a significant N x gender interaction was observed, demonstrating flatter cortisol rhythms across the waking day among male participants with higher N. Elevated I, however, was associated with lower cortisol awakening responses for both male and female participants, and higher cortisol at the time of waking for male participants only. The present study supports personality as a significant predictor of diurnal cortisol patterns in late adolescence, after accounting for the effects of demographic and health covariates, and suggests that gender plays a role in moderating associations between personality and cortisol.
Neuroticism and Introversion are Associated with Salivary Cortisol Patterns in Adolescents
Hauner, Katherina K. Y.; Adam, Emma K.; Mineka, Susan; Doane, Leah D.; DeSantis, Amy S.; Zinbarg, Richard; Craske, Michelle; Griffith, James W.
2008-01-01
Previous studies have yielded equivocal findings on the relationship between personality and cortisol activity. The present study examined associations between personality and cortisol activity in a large, diverse adolescent sample, while partialling the effects of relevant demographic and health-related covariates. A subsample of 230 participants (57% of whom reported elevated neuroticism) was selected from a larger sample of 16- to 18-year-olds involved in a study on risk factors for emotional disorders. Subsample participants completed a battery of personality questionnaires, and saliva collection was requested several months later on three consecutive days at six time points per day, from wakeup to bedtime. Associations between personality and cortisol rhythms were examined using multilevel growth curve modeling. Neuroticism (N) and introversion (I) were significantly and differentially associated with features of diurnal cortisol patterns. Specifically, a significant N by gender interaction was observed, demonstrating flatter cortisol rhythms across the waking day among male participants with higher N. Elevated I, however, was associated with lower cortisol awakening responses for both male and female participants, and higher cortisol at the time of waking for male participants only. The present study supports personality as a significant predictor of diurnal cortisol patterns in late adolescence, after accounting for the effects of demographic and health covariates, and suggests that gender plays a role in moderating associations between personality and cortisol. PMID:18809259
Magalhães, P V; Dean, O M; Bush, A I; Copolov, D L; Malhi, G S; Kohlmann, K; Jeavons, S; Schapkaitz, I; Anderson-Hunt, M; Berk, M
2011-03-01
The evidence base for the pharmacological treatment of bipolar II disorder is limited. In bipolar disorder, there is evidence for glutathione depletion and increased oxidative stress, as well as dysregulation of glutamate; N-acetyl cysteine (NAC) has effects on both of these systems. Add-on NAC has been shown to have a significant benefit on depressive symptoms in a randomized placebo-controlled trial. In this report, we explore the effects of this compound in a subset of patients with bipolar II disorder from that trial. Individuals were randomized to NAC or placebo in addition to treatment as usual, in a double-blind fashion. Mood and functional outcomes were assessed up to 24 weeks of treatment. Fourteen individuals were available for this report, seven in each group. Six people achieved full remission of both depressive and manic symptoms in the NAC group; this was true for only two people in the placebo group (χ(2)=4.67, p=0.031). Subgroup analyses in a small subsample of patients. Not all participants had elevated depression scores at baseline. Notwithstanding all the limitations that subgroup analysis of trials carry, this data could serve as a hypothesis-generating stimulus for further clinical trials of pharmacologic treatment for bipolar II depression. Copyright © 2010 Elsevier B.V. All rights reserved.
Edwards, Jerri D.; O’Connor, Melissa L.; Ball, Karlene K.; Wadley, Virginia G.; Vance, David E.
2016-01-01
Objectives. Multilevel models assessed the effects of cognitive speed of processing training (SPT) on older adults’ self-reported driving using intention-to-treat (ITT, randomization to training or control conditions) and dosage (treatment-received via number of training sessions) analyses across 5 years. Method. Participants randomized to SPT (n = 598) were compared with those randomized to either the no-contact control (n = 598) or memory training, which served as an active control (n = 610). Driving mobility (frequency, exposure, and space) was assessed over time. Results. No significant effects were found within the ITT analyses. However, number of SPT sessions did affect driving mobility outcomes. In the full sample (N = 1,806), higher SPT doses were associated with maintained driving frequency as compared with both control groups, but no effects were found for driving exposure or space. Subsample analyses (n = 315) revealed that persons at-risk for mobility declines (i.e., poor initial processing speed) who received additional booster SPT sessions reported greater maintenance of both driving frequency and exposure over time as compared with the no-contact and active control groups. Discussion. These results and prior research indicate that cognitive SPT transfers to prolonged driving mobility among older adults. Future research should investigate the mechanisms behind transfer effects to real-world activities, such as driving. PMID:25878053
Estimating the Size of a Large Network and its Communities from a Random Sample
Chen, Lin; Karbasi, Amin; Crawford, Forrest W.
2017-01-01
Most real-world networks are too large to be measured or studied directly and there is substantial interest in estimating global network properties from smaller sub-samples. One of the most important global properties is the number of vertices/nodes in the network. Estimating the number of vertices in a large network is a major challenge in computer science, epidemiology, demography, and intelligence analysis. In this paper we consider a population random graph G = (V, E) from the stochastic block model (SBM) with K communities/blocks. A sample is obtained by randomly choosing a subset W ⊆ V and letting G(W) be the induced subgraph in G of the vertices in W. In addition to G(W), we observe the total degree of each sampled vertex and its block membership. Given this partial information, we propose an efficient PopULation Size Estimation algorithm, called PULSE, that accurately estimates the size of the whole population as well as the size of each community. To support our theoretical analysis, we perform an exhaustive set of experiments to study the effects of sample size, K, and SBM model parameters on the accuracy of the estimates. The experimental results also demonstrate that PULSE significantly outperforms a widely-used method called the network scale-up estimator in a wide variety of scenarios. PMID:28867924
Estimating the Size of a Large Network and its Communities from a Random Sample.
Chen, Lin; Karbasi, Amin; Crawford, Forrest W
2016-01-01
Most real-world networks are too large to be measured or studied directly and there is substantial interest in estimating global network properties from smaller sub-samples. One of the most important global properties is the number of vertices/nodes in the network. Estimating the number of vertices in a large network is a major challenge in computer science, epidemiology, demography, and intelligence analysis. In this paper we consider a population random graph G = ( V, E ) from the stochastic block model (SBM) with K communities/blocks. A sample is obtained by randomly choosing a subset W ⊆ V and letting G ( W ) be the induced subgraph in G of the vertices in W . In addition to G ( W ), we observe the total degree of each sampled vertex and its block membership. Given this partial information, we propose an efficient PopULation Size Estimation algorithm, called PULSE, that accurately estimates the size of the whole population as well as the size of each community. To support our theoretical analysis, we perform an exhaustive set of experiments to study the effects of sample size, K , and SBM model parameters on the accuracy of the estimates. The experimental results also demonstrate that PULSE significantly outperforms a widely-used method called the network scale-up estimator in a wide variety of scenarios.
Adapted random sampling patterns for accelerated MRI.
Knoll, Florian; Clason, Christian; Diwoky, Clemens; Stollberger, Rudolf
2011-02-01
Variable density random sampling patterns have recently become increasingly popular for accelerated imaging strategies, as they lead to incoherent aliasing artifacts. However, the design of these sampling patterns is still an open problem. Current strategies use model assumptions like polynomials of different order to generate a probability density function that is then used to generate the sampling pattern. This approach relies on the optimization of design parameters which is very time consuming and therefore impractical for daily clinical use. This work presents a new approach that generates sampling patterns by making use of power spectra of existing reference data sets and hence requires neither parameter tuning nor an a priori mathematical model of the density of sampling points. The approach is validated with downsampling experiments, as well as with accelerated in vivo measurements. The proposed approach is compared with established sampling patterns, and the generalization potential is tested by using a range of reference images. Quantitative evaluation is performed for the downsampling experiments using RMS differences to the original, fully sampled data set. Our results demonstrate that the image quality of the method presented in this paper is comparable to that of an established model-based strategy when optimization of the model parameter is carried out and yields superior results to non-optimized model parameters. However, no random sampling pattern showed superior performance when compared to conventional Cartesian subsampling for the considered reconstruction strategy.
Ji, Jim; Wright, Steven
2005-01-01
Parallel imaging using multiple phased-array coils and receiver channels has become an effective approach to high-speed magnetic resonance imaging (MRI). To obtain high spatiotemporal resolution, the k-space is subsampled and later interpolated using multiple channel data. Higher subsampling factors result in faster image acquisition. However, the subsampling factors are upper-bounded by the number of parallel channels. Phase constraints have been previously proposed to overcome this limitation with some success. In this paper, we demonstrate that in certain applications it is possible to obtain acceleration factors potentially up to twice the channel numbers by using a real image constraint. Data acquisition and processing methods to manipulate and estimate of the image phase information are presented for improving image reconstruction. In-vivo brain MRI experimental results show that accelerations up to 6 are feasible with 4-channel data.
Continuum radiation from active galactic nuclei: A statistical study
NASA Technical Reports Server (NTRS)
Isobe, T.; Feigelson, E. D.; Singh, K. P.; Kembhavi, A.
1986-01-01
The physics of the continuum spectrum of active galactic nuclei (AGNs) was examined using a large data set and rigorous statistical methods. A data base was constructed for 469 objects which include radio selected quasars, optically selected quasars, X-ray selected AGNs, BL Lac objects, and optically unidentified compact radio sources. Each object has measurements of its radio, optical, X-ray core continuum luminosity, though many of them are upper limits. Since many radio sources have extended components, the core component were carefully selected out from the total radio luminosity. With survival analysis statistical methods, which can treat upper limits correctly, these data can yield better statistical results than those previously obtained. A variety of statistical tests are performed, such as the comparison of the luminosity functions in different subsamples, and linear regressions of luminosities in different bands. Interpretation of the results leads to the following tentative conclusions: the main emission mechanism of optically selected quasars and X-ray selected AGNs is thermal, while that of BL Lac objects is synchrotron; radio selected quasars may have two different emission mechanisms in the X-ray band; BL Lac objects appear to be special cases of the radio selected quasars; some compact radio sources show the possibility of synchrotron self-Compton (SSC) in the optical band; and the spectral index between the optical and the X-ray bands depends on the optical luminosity.
Random whole metagenomic sequencing for forensic discrimination of soils.
Khodakova, Anastasia S; Smith, Renee J; Burgoyne, Leigh; Abarno, Damien; Linacre, Adrian
2014-01-01
Here we assess the ability of random whole metagenomic sequencing approaches to discriminate between similar soils from two geographically distinct urban sites for application in forensic science. Repeat samples from two parklands in residential areas separated by approximately 3 km were collected and the DNA was extracted. Shotgun, whole genome amplification (WGA) and single arbitrarily primed DNA amplification (AP-PCR) based sequencing techniques were then used to generate soil metagenomic profiles. Full and subsampled metagenomic datasets were then annotated against M5NR/M5RNA (taxonomic classification) and SEED Subsystems (metabolic classification) databases. Further comparative analyses were performed using a number of statistical tools including: hierarchical agglomerative clustering (CLUSTER); similarity profile analysis (SIMPROF); non-metric multidimensional scaling (NMDS); and canonical analysis of principal coordinates (CAP) at all major levels of taxonomic and metabolic classification. Our data showed that shotgun and WGA-based approaches generated highly similar metagenomic profiles for the soil samples such that the soil samples could not be distinguished accurately. An AP-PCR based approach was shown to be successful at obtaining reproducible site-specific metagenomic DNA profiles, which in turn were employed for successful discrimination of visually similar soil samples collected from two different locations.
Bonuck, Karen; Barnett, Josephine; Lischewski-Goel, Jennifer
2012-01-01
Abstract Objective This study examined women's perceptions and reported effects of routine, primary care-based interventions to increase breastfeeding. Subjects and Methods A subsample (n=67) of participants in randomized controlled trials (RCTs) completed semistructured exit interviews at 6 months postpartum. RCT arms included the following: (a) routine pre-/postnatal lactation consultant (LC) support (LC group); (b) electronic prompts (EP) guiding providers to discuss breastfeeding during prenatal care visits (EP group); (c) a combined intervention (LC+EP group); and (d) controls. Interview transcripts were coded and analyzed in MAX.qda. Results Key findings included the following: (1) Brief, non-directive assessment of feeding via postpartum interviews focused attention upon feeding practices. When coupled with breastfeeding promotion interventions, interviews promoted breastfeeding. (2) The EP and LC interventions were complementary: EPs influenced initiation, while LCs helped overcome barriers and sustain breastfeeding. (3) Prenatal intent to feed both breastmilk and formula was associated with the greatest receptivity to study messages. Conclusions Findings underscore the need for interventions across the continuum of care. Trained LCs in prenatal/postpartum settings and prenatal care providers play important complementary roles that, when coupled with brief telephone feeding assessments, may improve breastfeeding rates. PMID:22621223
Sherbourne, Cathy; Chung, Bowen; Tang, Lingqi; Wright, Aziza L.; Whittington, Yolanda; Wells, Kenneth; Miranda, Jeanne
2016-01-01
Objectives. To compare the effectiveness of a (CEP) versus a technical assistance approach (Resources for Services, or RS) to disseminate depression care for low-income ethnic minority women. Methods. We conducted secondary analyses of intervention effects for largely low-income, minority women subsample (n = 595; 45.1% Latino and 45.4% African American) in a matched, clustered, randomized control trial conducted in 2 low-resource communities in Los Angeles, California, between 2010 and 2012. Outcomes assessed included mental health, socioeconomic factors, and service use at 6- and 12-month follow-up. Results. Although we found no intervention difference for depressive symptoms, there were statistically significant effects for mental health quality of life, resiliency, homelessness risk, and financial difficulties at 6 months, as well as missed work days, self-efficacy, and care barriers at 12 months favoring CEP relative to RS. CEP increased use of outpatient substance abuse services and faith-based depression visits at 6 months. Conclusions. Engaging health care and social community programs may offer modest improvements on key functional and socioeconomic outcomes, reduce care barriers, and increase engagement in alternative depression services for low-income, predominantly ethnic minority women. PMID:27552274
Andaya, Elise; Bonuck, Karen; Barnett, Josephine; Lischewski-Goel, Jennifer
2012-12-01
This study examined women's perceptions and reported effects of routine, primary care-based interventions to increase breastfeeding. A subsample (n=67) of participants in randomized controlled trials (RCTs) completed semistructured exit interviews at 6 months postpartum. RCT arms included the following: (a) routine pre-/postnatal lactation consultant (LC) support (LC group); (b) electronic prompts (EP) guiding providers to discuss breastfeeding during prenatal care visits (EP group); (c) a combined intervention (LC+EP group); and (d) controls. Interview transcripts were coded and analyzed in MAX.qda. Key findings included the following: (1) Brief, non-directive assessment of feeding via postpartum interviews focused attention upon feeding practices. When coupled with breastfeeding promotion interventions, interviews promoted breastfeeding. (2) The EP and LC interventions were complementary: EPs influenced initiation, while LCs helped overcome barriers and sustain breastfeeding. (3) Prenatal intent to feed both breastmilk and formula was associated with the greatest receptivity to study messages. Findings underscore the need for interventions across the continuum of care. Trained LCs in prenatal/postpartum settings and prenatal care providers play important complementary roles that, when coupled with brief telephone feeding assessments, may improve breastfeeding rates.
CLASH: Weak-lensing shear-and-magnification analysis of 20 galaxy clusters
DOE Office of Scientific and Technical Information (OSTI.GOV)
Umetsu, Keiichi; Czakon, Nicole; Medezinski, Elinor
2014-11-10
We present a joint shear-and-magnification weak-lensing analysis of a sample of 16 X-ray-regular and 4 high-magnification galaxy clusters at 0.19 ≲ z ≲ 0.69 selected from the Cluster Lensing And Supernova survey with Hubble (CLASH). Our analysis uses wide-field multi-color imaging, taken primarily with Suprime-Cam on the Subaru Telescope. From a stacked-shear-only analysis of the X-ray-selected subsample, we detect the ensemble-averaged lensing signal with a total signal-to-noise ratio of ≅ 25 in the radial range of 200-3500 kpc h {sup –1}, providing integrated constraints on the halo profile shape and concentration-mass relation. The stacked tangential-shear signal is well described bymore » a family of standard density profiles predicted for dark-matter-dominated halos in gravitational equilibrium, namely, the Navarro-Frenk-White (NFW), truncated variants of NFW, and Einasto models. For the NFW model, we measure a mean concentration of c{sub 200c}=4.01{sub −0.32}{sup +0.35} at an effective halo mass of M{sub 200c}=1.34{sub −0.09}{sup +0.10}×10{sup 15} M{sub ⊙}. We show that this is in excellent agreement with Λ cold dark matter (ΛCDM) predictions when the CLASH X-ray selection function and projection effects are taken into account. The best-fit Einasto shape parameter is α{sub E}=0.191{sub −0.068}{sup +0.071}, which is consistent with the NFW-equivalent Einasto parameter of ∼0.18. We reconstruct projected mass density profiles of all CLASH clusters from a joint likelihood analysis of shear-and-magnification data and measure cluster masses at several characteristic radii assuming an NFW density profile. We also derive an ensemble-averaged total projected mass profile of the X-ray-selected subsample by stacking their individual mass profiles. The stacked total mass profile, constrained by the shear+magnification data, is shown to be consistent with our shear-based halo-model predictions, including the effects of surrounding large-scale structure as a two-halo term, establishing further consistency in the context of the ΛCDM model.« less
X-ray Selected Symbiotic Candidates in the Galactic Bulge Survey
NASA Astrophysics Data System (ADS)
Hynes, Robert I.; Wetuski, Joshua` D.; Jonker, Peter; Torres, Manuel; Heinke, Craig O.; Maccarone, Tom; Steeghs, Danny; Britt, Christopher; Johnson, Christopher; Nelemans, Gijs
2017-06-01
The Galactic Bulge Survey (GBS) is a broad, shallow survey of Bulge X-ray sources with extensive multiwavelength support. The limiting sensitivity, about 2×1032 erg/s at the Bulge distance, is well suited to finding symbiotic X-ray binaries (SyXBs) containing neutron stars accreting from a cool giant wind, as well as X-ray bright white dwarf systems. Giant counterparts can be securely detected in IR photometry, allowing us to estimate the total number of symbiotics detected by the GBS, and identify a good number of promising candidates. Such an X-ray selected symbiotic sample may be quite different to the traditional symbiotic star population which is usually selected by optical spectroscopy, and consequently biased towards systems with rich line emission. Of the 1640 unique X-ray sources identified by the GBS we find 91 significant matches with candidate Bulge giants. We expect 68 coincidences, so estimate a total sample of about 23 X-ray emitting cool giants detected by the GBS. Most of these are likely to be SyXBs or symbiotics of some type. Narrowing our search to sources coincident to 1", we find 23 matches, with only 8 coincidences expected, so this subsample has a relatively high purity, and likely includes most of the GBS symbiotics. The properties of this subsample are mostly consistent with cool giants, with typical SEDs, long-term lightcurves, and spectra. The sources are inconsistent in color with nearby M dwarfs and show small proper motions, so the foreground contamination is likely small. We present a selection of the best studied objects, focusing on one extremely variable X-ray source coincident with a carbon giant. This is quite an unusual object as carbon stars are rare in the Bulge. The scientific results reported in this article are based on observations made by the Chandra X-ray Observatory and data obtained from the Chandra Data Archive. Support for this work was provided by the National Aeronautics and Space Administration through Chandra Award Numbers GO4-15047X and AR5-16004X issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics Space Administration under contract NAS8-03060.
2012-01-01
Background The autism rate has recently increased to 1 in 100 children. Genetic studies demonstrate poorly understood complexity. Environmental factors apparently also play a role. Magnetic resonance imaging (MRI) studies demonstrate increased brain sizes and altered connectivity. Electroencephalogram (EEG) coherence studies confirm connectivity changes. However, genetic-, MRI- and/or EEG-based diagnostic tests are not yet available. The varied study results likely reflect methodological and population differences, small samples and, for EEG, lack of attention to group-specific artifact. Methods Of the 1,304 subjects who participated in this study, with ages ranging from 1 to 18 years old and assessed with comparable EEG studies, 463 children were diagnosed with autism spectrum disorder (ASD); 571 children were neuro-typical controls (C). After artifact management, principal components analysis (PCA) identified EEG spectral coherence factors with corresponding loading patterns. The 2- to 12-year-old subsample consisted of 430 ASD- and 554 C-group subjects (n = 984). Discriminant function analysis (DFA) determined the spectral coherence factors' discrimination success for the two groups. Loading patterns on the DFA-selected coherence factors described ASD-specific coherence differences when compared to controls. Results Total sample PCA of coherence data identified 40 factors which explained 50.8% of the total population variance. For the 2- to 12-year-olds, the 40 factors showed highly significant group differences (P < 0.0001). Ten randomly generated split half replications demonstrated high-average classification success (C, 88.5%; ASD, 86.0%). Still higher success was obtained in the more restricted age sub-samples using the jackknifing technique: 2- to 4-year-olds (C, 90.6%; ASD, 98.1%); 4- to 6-year-olds (C, 90.9%; ASD 99.1%); and 6- to 12-year-olds (C, 98.7%; ASD, 93.9%). Coherence loadings demonstrated reduced short-distance and reduced, as well as increased, long-distance coherences for the ASD-groups, when compared to the controls. Average spectral loading per factor was wide (10.1 Hz). Conclusions Classification success suggests a stable coherence loading pattern that differentiates ASD- from C-group subjects. This might constitute an EEG coherence-based phenotype of childhood autism. The predominantly reduced short-distance coherences may indicate poor local network function. The increased long-distance coherences may represent compensatory processes or reduced neural pruning. The wide average spectral range of factor loadings may suggest over-damped neural networks. PMID:22730909
Marques, Elsa; Johnson, Emma C; Gooberman-Hill, Rachael; Blom, Ashley W; Noble, Sian
2013-01-01
Economic evaluations alongside randomized controlled trials that collect data using patient-completed questionnaires are prone to missing data. Our objective was to determine whether giving patients a resource use log (RUL) at baseline would improve the odds of completing questions in a follow-up resource use questionnaire (RUQ) and to identify patients' views on RUL's usefulness and acceptability. The RUL study was a randomized controlled trial and qualitative study nested within a larger randomized controlled trial (the Arthroplasty Pain Experience Study trial). Eighty-five patients were randomized at baseline to receive or not receive an RUL. At 3-month follow-up, all participants received a postal RUQ. We created dummy variables for 13 resource use categories indicating whether complete information had been given for each category. We compared the completion rates between arms by using descriptive statistics and logistic regression. We explored patients' experience of using the RUL by interviewing a different subsample of Arthroplasty Pain Experience Study patients (n = 24) at 2- to 4-week follow-up. At 3 months, 74 of the 85 (87% in each arm) patients returned the RUQ. Patients in the RUL arm were 3.5 times more likely to complete the National Health Service community-based services category (P = 0.08). The RUL was positively received by patients and was generally seen as a useful memory aid. The RUL is a useful and acceptable tool in reducing the amount of missing data for some types of resource use. Copyright © 2013 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sesar, Branimir; Ivezic, Zeljko; Morgan, Dylan M.
We present a sample of {approx}5000 RR Lyrae stars selected from the recalibrated LINEAR data set and detected at heliocentric distances between 5 kpc and 30 kpc over {approx}8000 deg{sup 2} of sky. The coordinates and light curve properties, such as period and Oosterhoff type, are made publicly available. We analyze in detail the light curve properties and Galactic distribution of the subset of {approx}4000 type ab RR Lyrae (RRab) stars, including a search for new halo substructures and the number density distribution as a function of Oosterhoff type. We find evidence for the Oosterhoff dichotomy among field RR Lyraemore » stars, with the ratio of the type II and I subsamples of about 1:4, but with a weaker separation than for globular cluster stars. The wide sky coverage and depth of this sample allow unique constraints for the number density distribution of halo RRab stars as a function of galactocentric distance: it can be described as an oblate ellipsoid with an axis ratio q = 0.63 and with either a single or a double power law with a power-law index in the range -2 to -3. Consistent with previous studies, we find that the Oosterhoff type II subsample has a steeper number density profile than the Oosterhoff type I subsample. Using the group-finding algorithm EnLink, we detected seven candidate halo groups, only one of which is statistically spurious. Three of these groups are near globular clusters (M53/NGC 5053, M3, M13), and one is near a known halo substructure (Virgo Stellar Stream); the remaining three groups do not seem to be near any known halo substructures or globular clusters and seem to have a higher ratio of Oosterhoff type II to Oosterhoff type I RRab stars than what is found in the halo. The extended morphology and the position (outside the tidal radius) of some of the groups near globular clusters are suggestive of tidal streams possibly originating from globular clusters. Spectroscopic follow-up of detected halo groups is encouraged.« less
NASA Astrophysics Data System (ADS)
Sesar, Branimir; Ivezić, Željko; Stuart, J. Scott; Morgan, Dylan M.; Becker, Andrew C.; Sharma, Sanjib; Palaversa, Lovro; Jurić, Mario; Wozniak, Przemyslaw; Oluseyi, Hakeem
2013-08-01
We present a sample of ~5000 RR Lyrae stars selected from the recalibrated LINEAR data set and detected at heliocentric distances between 5 kpc and 30 kpc over ~8000 deg2 of sky. The coordinates and light curve properties, such as period and Oosterhoff type, are made publicly available. We analyze in detail the light curve properties and Galactic distribution of the subset of ~4000 type ab RR Lyrae (RRab) stars, including a search for new halo substructures and the number density distribution as a function of Oosterhoff type. We find evidence for the Oosterhoff dichotomy among field RR Lyrae stars, with the ratio of the type II and I subsamples of about 1:4, but with a weaker separation than for globular cluster stars. The wide sky coverage and depth of this sample allow unique constraints for the number density distribution of halo RRab stars as a function of galactocentric distance: it can be described as an oblate ellipsoid with an axis ratio q = 0.63 and with either a single or a double power law with a power-law index in the range -2 to -3. Consistent with previous studies, we find that the Oosterhoff type II subsample has a steeper number density profile than the Oosterhoff type I subsample. Using the group-finding algorithm EnLink, we detected seven candidate halo groups, only one of which is statistically spurious. Three of these groups are near globular clusters (M53/NGC 5053, M3, M13), and one is near a known halo substructure (Virgo Stellar Stream); the remaining three groups do not seem to be near any known halo substructures or globular clusters and seem to have a higher ratio of Oosterhoff type II to Oosterhoff type I RRab stars than what is found in the halo. The extended morphology and the position (outside the tidal radius) of some of the groups near globular clusters are suggestive of tidal streams possibly originating from globular clusters. Spectroscopic follow-up of detected halo groups is encouraged.
Aboal, J R; Boquete, M T; Carballeira, A; Casanova, A; Debén, S; Fernández, J A
2017-05-01
In this study we examined 6080 data gathered by our research group during more than 20 years of research on the moss biomonitoring technique, in order to quantify the variability generated by different aspects of the protocol and to calculate the overall measurement uncertainty associated with the technique. The median variance of the concentrations of different pollutants measured in moss tissues attributed to the different methodological aspects was high, reaching values of 2851 (ng·g -1 ) 2 for Cd (sample treatment), 35.1 (μg·g -1 ) 2 for Cu (sample treatment), 861.7 (ng·g -1 ) 2 and for Hg (material selection). These variances correspond to standard deviations that constitute 67, 126 and 59% the regional background levels of these elements in the study region. The overall measurement uncertainty associated with the worst experimental protocol (5 subsamples, refrigerated, washed, 5 × 5 m size of the sampling area and once a year sampling) was between 2 and 6 times higher than that associated with the optimal protocol (30 subsamples, dried, unwashed, 20 × 20 m size of the sampling area and once a week sampling), and between 1.5 and 7 times higher than that associated with the standardized protocol (30 subsamples and once a year sampling). The overall measurement uncertainty associated with the standardized protocol could generate variations of between 14 and 47% in the regional background levels of Cd, Cu, Hg, Pb and Zn in the study area and much higher levels of variation in polluted sampling sites. We demonstrated that although the overall measurement uncertainty of the technique is still high, it can be reduced by using already well defined aspects of the protocol. Further standardization of the protocol together with application of the information on the overall measurement uncertainty would improve the reliability and comparability of the results of different biomonitoring studies, thus extending use of the technique beyond the context of scientific research. Copyright © 2017 Elsevier Ltd. All rights reserved.
Karapanagioti, Hrissi K.; Kleineidam, Sybille; Sabatini, David A.; Grathwohl, Peter; Ligouis, Bertrand
2000-01-01
Sediment organic matter heterogeneity in sediments is shown to impact the sorption behavior of contaminants. We investigated the sorptive properties as well as the composition of organic matter in different subsamples (mainly grain size fractions) of the Canadian River Alluvium (CRA). Organic petrography was used as a new tool to describe and characterize the organic matter in the subsamples. The samples studied contained many different types of organic matter including bituminous coal particles. Differences in sorption behavior were explained based on these various types of organic matter. Subsamples containing predominately coaly, particulate organic matter showed the highest Koc, the highest nonlinearity of sorption isotherms and the slowest sorption kinetics. Soil subsamples with organic matter present as organic coatings around the quartz grains evidenced the lowest Koc, the most linear sorption isotherms and the fastest sorption kinetics, which was not limited by slow intraparticle diffusion. Due to the high sorption capacity of the coaly particles even when it is present as only a small fraction of the composite organic content (<3%) causes Koc values which are much higher than expected for soil organic matter (e.g. Koc − Kow relationships). The results show that the identification and quantification of the coaly particles within a sediment or soil sample is a prerequisite in order to understand or predict sorption behavior of organic pollutants.
Esser, Peter; Kuba, Katharina; Mehnert, Anja; Johansen, Christoffer; Hinz, Andreas; Lordick, Florian; Götze, Heide
2018-06-01
Quality of life (QoL) has become an important tool to guide decision making in oncology. Given the heterogeneity among hematological cancer survivors, however, clinicians need comparative data across different subsets. This study recruited survivors of hematological malignancies (≥ 2.5 years after diagnosis) from two German cancer registries. QoL was assessed with the EORTC QLQ-C30. The sample was stratified by cancer type, time since diagnosis, treatment with stem cell transplantation (SCT) and type of SCT. First, levels of QoL were compared across subsamples when controlling for several covariates. Second, we contrasted subsamples with gender- and age-matched population controls obtained from the general population. Of 2001 survivors contacted by mail, 922 (46%) participated in the study. QoL did not significantly differ between the subsamples. All subsamples scored significantly lower in functioning and significantly higher in symptom burden compared to population controls (all p < .001). Almost all of these group effects reached clinically meaningful sizes (Cohen's d ≥ .5). Group differences in global health/QoL were mostly non-significant. Hematological cancer survivors are associated with practically relevant impairments irrespective of differences in central medical characteristics. Nevertheless, survivors seem to evaluate their overall situation as relatively well. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
2011-01-01
Background Knowledge in natural sciences generally predicts study performance in the first two years of the medical curriculum. In order to reduce delay and dropout in the preclinical years, Hamburg Medical School decided to develop a natural science test (HAM-Nat) for student selection. In the present study, two different approaches to scale construction are presented: a unidimensional scale and a scale composed of three subject specific dimensions. Their psychometric properties and relations to academic success are compared. Methods 334 first year medical students of the 2006 cohort responded to 52 multiple choice items from biology, physics, and chemistry. For the construction of scales we generated two random subsamples, one for development and one for validation. In the development sample, unidimensional item sets were extracted from the item pool by means of weighted least squares (WLS) factor analysis, and subsequently fitted to the Rasch model. In the validation sample, the scales were subjected to confirmatory factor analysis and, again, Rasch modelling. The outcome measure was academic success after two years. Results Although the correlational structure within the item set is weak, a unidimensional scale could be fitted to the Rasch model. However, psychometric properties of this scale deteriorated in the validation sample. A model with three highly correlated subject specific factors performed better. All summary scales predicted academic success with an odds ratio of about 2.0. Prediction was independent of high school grades and there was a slight tendency for prediction to be better in females than in males. Conclusions A model separating biology, physics, and chemistry into different Rasch scales seems to be more suitable for item bank development than a unidimensional model, even when these scales are highly correlated and enter into a global score. When such a combination scale is used to select the upper quartile of applicants, the proportion of successful completion of the curriculum after two years is expected to rise substantially. PMID:21999767
Questioning care at the end of life.
Ruopp, Patricia; Good, Mary-Jo Delvecchio; Lakoma, Matthew; Gadmer, Nina M; Arnold, Robert M; Block, Susan D
2005-06-01
The goal of the larger study was to explore physicians' emotional responses to the death of their patients; this study analyzed a subset of physician transcripts to elucidate the construct of questioning care, which emerged from the larger study. To analyzes how physicians question care-expressing concern, unease, or uncertainty about treatment decisions and practices, errors, or adverse events-as they attend dying patients. Retrospective interview study of physicians caring for randomly selected deaths on the medical service of a major academic teaching hospital, using qualitative and quantitative measures. SETTING, SUBJECTS: 188 attendings, residents, and interns on the internal medical services of two academic medical centers were part of the larger study. A subsample of 75 physician narratives was selected for qualitative data analysis for this study. Qualitative measures included open-ended questions eliciting physicians' stories of the most recent and a most emotionally powerful patient death they have experienced. Grounded theory was used to analyze physician narratives. Quantitative instruments measured physician attitudes toward end-of-life care and responses to the most recent and most emotional patient death. Physicians question care more frequently in most emotional deaths (42%) than in most recent deaths (34%). Physicians question communication with patients and families and within medical teams, medical judgment and technique, standards of practice, and high-risk treatments, often assigning responsibility for medical management they perceive as inappropriate, futile, overly aggressive, or mistakes in judgment and technique. Responsibility ranges from the distal (the culture of medicine) to the proximal (personal). Frustration, guilt, and anger are more frequently expressed in these narratives when care is questioned. A typology of questioning care emerged from these physicians' narratives that parallels and reflects recent and classic research on medical error and the culture of medicine. Physicians' questions about care can contribute to designing training experiences for residents and to improving the quality of systems that affect patients' experiences at life's end and physicians' experiences in caring for dying patients.
Hissbach, Johanna C; Klusmann, Dietrich; Hampe, Wolfgang
2011-10-14
Knowledge in natural sciences generally predicts study performance in the first two years of the medical curriculum. In order to reduce delay and dropout in the preclinical years, Hamburg Medical School decided to develop a natural science test (HAM-Nat) for student selection. In the present study, two different approaches to scale construction are presented: a unidimensional scale and a scale composed of three subject specific dimensions. Their psychometric properties and relations to academic success are compared. 334 first year medical students of the 2006 cohort responded to 52 multiple choice items from biology, physics, and chemistry. For the construction of scales we generated two random subsamples, one for development and one for validation. In the development sample, unidimensional item sets were extracted from the item pool by means of weighted least squares (WLS) factor analysis, and subsequently fitted to the Rasch model. In the validation sample, the scales were subjected to confirmatory factor analysis and, again, Rasch modelling. The outcome measure was academic success after two years. Although the correlational structure within the item set is weak, a unidimensional scale could be fitted to the Rasch model. However, psychometric properties of this scale deteriorated in the validation sample. A model with three highly correlated subject specific factors performed better. All summary scales predicted academic success with an odds ratio of about 2.0. Prediction was independent of high school grades and there was a slight tendency for prediction to be better in females than in males. A model separating biology, physics, and chemistry into different Rasch scales seems to be more suitable for item bank development than a unidimensional model, even when these scales are highly correlated and enter into a global score. When such a combination scale is used to select the upper quartile of applicants, the proportion of successful completion of the curriculum after two years is expected to rise substantially.
Maternal exposure to childhood abuse is associated with elevated risk of autism
Roberts, Andrea L.; Lyall, Kristen; Rich-Edwards, Janet W.; Ascherio, Alberto; Weisskopf, Marc G.
2014-01-01
Context Adverse perinatal circumstances have been associated with increased risk of autism. Women exposed to childhood abuse experience more adverse perinatal circumstances than women unexposed, but whether abuse is associated with autism in offspring is unknown. Objective To determine whether maternal exposure to childhood abuse is associated with risk of autism, and whether possible increased risk is accounted for by higher prevalence of adverse perinatal circumstances among abused women, including gestational diabetes, preeclampsia, selective serotonin reuptake inhibitor use, intimate partner abuse, prior abortion, pregnancy less than 37 weeks, low birth weight, alcohol use, and smoking during pregnancy. Design and Setting Nurses’ Health Study II, a population-based longitudinal cohort of 116,430 women. Patients or Other Participants Participants with data on childhood abuse and child’s autism status (97% White). Controls were randomly selected from among children of women who did not report autism in offspring (N mothers of children with autism = 451; N mothers of children without autism=52,498). Main Outcome Measure Autism spectrum disorder, assessed by maternal report, validated with the Autism Diagnostic Interview-Revised in a subsample. Results Exposure to abuse was associated with increased risk of autism in children in a monotonically increasing fashion. The highest level of abuse was associated with the greatest prevalence of autism (1.8% versus 0.7% in women not abused, P = 0.005) and the greatest risk for autism adjusted for demographic factors (risk ratio=3.7, 95% confidence interval=2.3, 5.8). All adverse perinatal circumstances were more prevalent in women abused except low birth weight. Adjusted for perinatal factors, the association of maternal abuse with autism was slightly attenuated (highest level of abuse, risk ratio = 3.0, 95% confidence interval=1.9, 4.9). Conclusions We identify an intergenerational association between childhood exposure to abuse and risk for autism in the subsequent generation. Adverse perinatal circumstances accounted for only a small portion of this increased risk. PMID:23553149
Elementary Teachers' Selection and Use of Visual Models
NASA Astrophysics Data System (ADS)
Lee, Tammy D.; Gail Jones, M.
2018-02-01
As science grows in complexity, science teachers face an increasing challenge of helping students interpret models that represent complex science systems. Little is known about how teachers select and use models when planning lessons. This mixed methods study investigated the pedagogical approaches and visual models used by elementary in-service and preservice teachers in the development of a science lesson about a complex system (e.g., water cycle). Sixty-seven elementary in-service and 69 elementary preservice teachers completed a card sort task designed to document the types of visual models (e.g., images) that teachers choose when planning science instruction. Quantitative and qualitative analyses were conducted to analyze the card sort task. Semistructured interviews were conducted with a subsample of teachers to elicit the rationale for image selection. Results from this study showed that both experienced in-service teachers and novice preservice teachers tended to select similar models and use similar rationales for images to be used in lessons. Teachers tended to select models that were aesthetically pleasing and simple in design and illustrated specific elements of the water cycle. The results also showed that teachers were not likely to select images that represented the less obvious dimensions of the water cycle. Furthermore, teachers selected visual models more as a pedagogical tool to illustrate specific elements of the water cycle and less often as a tool to promote student learning related to complex systems.
This report is a description of field work and data analysis results comparing a design comparable to systematic site selection with one based on random selection of sites. The report is expected to validate the use of random site selection in the bioassessment program for the O...
2011-01-01
Background To simplify the methodology for the isolation of Campylobacter spp. from retail broiler meat, we evaluated 108 samples (breasts and thighs) using an unpaired sample design. The enrichment broths were incubated under aerobic conditions (subsamples A) and for comparison under microaerobic conditions (subsamples M) as recommended by current reference protocols. Sensors were used to measure the dissolved oxygen (DO) in the broth and the percentage of oxygen (O2) in the head space of the bags used for enrichment. Campylobacter isolates were identified with multiplex PCR assays and typed using pulsed-field gel electrophoresis (PFGE). Ribosomal intergenic spacer analyses (RISA) and denaturing gradient gel electrophoresis (DGGE) were used to study the bacterial communities of subsamples M and A after 48 h enrichment. Results The number of Campylobacter positive subsamples were similar for A and M when all samples were combined (P = 0.81) and when samples were analyzed by product (breast: P = 0.75; thigh: P = 1.00). Oxygen sensors showed that DO values in the broth were around 6 ppm and O2 values in the head space were 14-16% throughout incubation. PFGE demonstrated high genomic similarity of isolates in the majority of the samples in which isolates were obtained from subsamples A and M. RISA and DGGE results showed a large variability in the bacterial populations that could be attributed to sample-to-sample variations and not enrichment conditions (aerobic or microaerobic). These data also suggested that current sampling protocols are not optimized to determine the true number of Campylobacter positive samples in retail boiler meat. Conclusions Decreased DO in enrichment broths is naturally achieved. This simplified, cost-effective enrichment protocol with aerobic incubation could be incorporated into reference methods for the isolation of Campylobacter spp. from retail broiler meat. PMID:21812946
Ribeiro, Felipe Garcia; Carraro, André; Motta, Janaína Vieira Dos Santos; Gigante, Denise Petrucci
2016-06-01
Objective To investigate the social impact of literacy on the smoking behavior of illiterate individuals who share the household with literate individuals. Method This cross-sectional study employed data from the 2008 Brazilian National Household Survey (Pesquisa Nacional por Amostra de Domicílios, PNAD). Smokers were defined as individuals reporting use of any tobacco product daily or less than daily. The literacy profiles of residents were identified. Poisson regressions adjusted for skin color, age, and maximum level of literacy in the household were performed. Four groups were analyzed: men living in rural areas, men living in urban areas, women living in rural areas, and women living in urban areas. Results For urban men, the presence of literate women only in the household was a protection factor against smoking (prevalence ratio, PR: 0.77; 95%CI: 0.71-0.82) vs. households in which all the males were illiterate. The same protective effect was found for rural men (PR: 0.79; 95%CI: 0.73-0.85). In turn, the presence of literate men only living in the same household with illiterate men did not provide protection against smoking in any case (PR: 0.93; 95%CI: 0.83-1.03 for the urban subsample; and PR: 0.99; 95%CI: 0.88-1.11 for the rural subsample). Illiterate women benefited from the presence of both literate men (PR: 0.77; 95%CI: 0.71-0.84 for the urban sample; and PR: 0.78; 95%CI: 0.69-0.89 for the rural subsample) and literate women (PR: 0.81; 95%CI: 0.72-0.92 for the urban subsample; and PR: 0.75; IC95%: 0.60-0.93 for the rural subsample). Conclusions Literate women seem to have positively affected illiterate co-residents of both sexes. This result is in agreement with reports showing broad advantages of female schooling.
Berger, Ann M; Buzalko, Russell J; Kupzyk, Kevin A; Gardner, Bret J; Djalilova, Dilorom M; Otte, Julie L
2017-12-01
There is renewed interest in identifying breast cancer patients' participation in decision-making about adjuvant chemotherapy. There is a gap in the literature regarding the impact of these decisions on quality of life (QOL) and quality of care (QOC). Our aims were to determine similarities and differences in how patients diagnosed with breast cancer preferred to make decisions with providers about cancer treatment, to examine the patient's recall of her role when the decision was made about chemotherapy and to determine how preferred and actual roles, as well as congruence between them, relate to QOL and perceived QOC. Greater Plains Collaborative clinical data research network of PCORnet conducted the 'Share Thoughts on Breast Cancer' survey among women 12-18 months post-diagnosis at eight sites in seven Midwestern United States. Patients recalled their preferred and actual treatment decision-making roles and three new shared decision-making (SDM) variables were created. Patients completed QOL and QOC measurements. Correlations and t-tests were used. Of 1235 returned surveys, 873 (full sample) and 329 (subsample who received chemotherapy) were used. About one-half of women in both the full (50.7%) and subsample (49.8%,) preferred SDM with providers about treatment decisions, but only 41.2% (full) and 42.6% (subsample) reported experiencing SDM. Significant differences were found between preferred versus actual roles in the full (p < .001) and subsample (p < .004). In the full sample, there were no relationships between five decision-making variables with QOL, but there was an association with QOC. The subsample's decision-making variables related to several QOL scales and QOC items, with a more patient-centered decision than originally preferred related to higher physical and social/family well-being, overall QOL and QOC. Patients benefit from providers' efforts to identify patient preferences, encourage an active role in SDM, and tailor decision making to their desired choice.
Kawasaki, Yohei; Ide, Kazuki; Akutagawa, Maiko; Yamada, Hiroshi; Yutaka, Ono; Furukawa, Toshiaki A.
2017-01-01
Background Several recent studies have shown that total scores on depressive symptom measures in a general population approximate an exponential pattern except for the lower end of the distribution. Furthermore, we confirmed that the exponential pattern is present for the individual item responses on the Center for Epidemiologic Studies Depression Scale (CES-D). To confirm the reproducibility of such findings, we investigated the total score distribution and item responses of the Kessler Screening Scale for Psychological Distress (K6) in a nationally representative study. Methods Data were drawn from the National Survey of Midlife Development in the United States (MIDUS), which comprises four subsamples: (1) a national random digit dialing (RDD) sample, (2) oversamples from five metropolitan areas, (3) siblings of individuals from the RDD sample, and (4) a national RDD sample of twin pairs. K6 items are scored using a 5-point scale: “none of the time,” “a little of the time,” “some of the time,” “most of the time,” and “all of the time.” The pattern of total score distribution and item responses were analyzed using graphical analysis and exponential regression model. Results The total score distributions of the four subsamples exhibited an exponential pattern with similar rate parameters. The item responses of the K6 approximated a linear pattern from “a little of the time” to “all of the time” on log-normal scales, while “none of the time” response was not related to this exponential pattern. Discussion The total score distribution and item responses of the K6 showed exponential patterns, consistent with other depressive symptom scales. PMID:28289560
Kane, Jeremy C; Johnson, Renee M; Robinson, Courtland; Jernigan, David H; Harachi, Tracy W; Bass, Judith K
2016-11-01
Recent studies indicate that alcohol use is increasing among Asian American populations and that acculturation impacts alcohol use among immigrants in the USA. We investigated the longitudinal relationship between three domains of acculturation (traditionalism, biculturalism, assimilation) and alcohol use among 302 Vietnamese and Cambodian women in Washington State. Data were obtained from the Cross Cultural Families Project (CCF), a 5-year longitudinal investigation of a random sample of Vietnamese and Cambodian immigrant families living in Washington State. Alcohol use was measured with a three item scale assessing frequency and quantity of use, and binge drinking. Acculturation was measured with the Suinn-Lew Asian Self-Identity Acculturation Scale. Linear mixed effects regression models were estimated to assess the impact of acculturation on alcohol use among the overall sample and among a sub-sample of only women who consumed any alcohol. A majority of the sample, 73.2%, reported no alcohol use. In the overall sample, none of the three acculturation domains were significantly associated with drinking. Among a sub-sample of only those who reported any alcohol use, however, a greater degree of traditional cultural identification (β = -0.94, SE= 0.44, P= 0.03) and a greater degree of biculturalism (β = -1.33, SE= 0.53, P =0.01) were associated with lower levels of use. Our findings suggest that acculturation did not impact alcohol use prevalence but that it did affect the drinking pattern among alcohol consumers. Clinicians should be cognizant that certain aspects of cultural identification are important contributors to drinking behavior among alcohol consumers in these populations. © The Author 2016. Medical Council on Alcohol and Oxford University Press. All rights reserved.
Demmer, Ryan T; Zuk, Aleksandra M; Rosenbaum, Michael; Desvarieux, Moïse
2013-10-01
Although prevalence and incidence of type 2 diabetes mellitus (T2DM) are reportedly increasing among adolescents, national data are lacking, particularly in regard to undiagnosed T2DM. To estimate the prevalence of diagnosed and undiagnosed T2DM among US adolescents, we analyzed a nationally representative cross-section of 11,888 adolescents aged 12-19 years who received a diabetes interview in the Continuous National Health and Nutrition Examination Survey during 1999-2010. Among them, a random subsample of 4,661 adolescents also had fasting blood samples collected. Persons who reported a previous diabetes diagnosis and were either taking no medication or taking an oral hypoglycemic agent (with or without insulin) were classified as having T2DM; persons who reported using insulin alone were classified as having type 1 diabetes. Undiagnosed diabetes was defined as a fasting plasma glucose concentration of ≥126 mg/dL and was assumed to be type 2. In the fasting subsample, 31 diabetes cases (types 1 and 2) were identified, representing a prevalence of 0.84% (weighted 95% confidence interval (CI): 0.51, 1.40) (276,638 cases; 95% CI: 134,255, 419,020). Estimates of the prevalences of type 1 and type 2 diabetes were 0.48% (95% CI: 0.23, 1.02) and 0.36% (95% CI: 0.20, 0.67), respectively, indicating that T2DM accounted for 43% of all cases. Further, undiagnosed T2DM prevalence was 0.12% (95% CI: 0.05, 0.31), representing 34% of T2DM cases (40,611 cases; 95% CI: 2,850, 78,373). T2DM accounts for approximately half of adolescent diabetes in the United States, and one-third of these cases are undiagnosed.
Liu, Wen; Chen, Liang; Blue, Philip R.
2016-01-01
This study aimed to validate a Chinese’s adaption of the Cognitive Emotion Regulation Questionnaire for children (CERQ-Ck). This self-report instrument evaluates nine cognitive emotion regulation strategies that can be used by children after experiencing a negative life event. The CERQ-Ck was evaluated in a sample of 1403 elementary students between the ages of 9 and 11 by using cluster sampling. All the item-correlation coefficients for CERQ-Ck were above 0.30. The internal consistencies of the nine factors suggested moderate reliability (0.66 to 0.73). Confirmatory factor analysis (CFA) indicated that the current version had the same structure as the original instrument (Tucker–Lewis index = 0.912, comparative fit index = 0.922, root mean square error of approximation = 0.032, standardized root mean square residual = 0.044). A second-order factor and a third-order factor structure were also found. Test–retest correlations (0.53 to 0.70, ps < 0.01) over a period of 1 month, which ranged from acceptable to moderately strong were obtained from a random and stratified subsample of elementary students (N = 76). In addition, we analyzed convergent validity in relation to CERQ-Ck and the Chinese version of the Children’s Depression Inventory model dimensions with a subsample of 1083 elementary students. Multiple-group CFA confirmed the measurement invariance for both the male and female groups (ΔCFI < 0.01, ΔRMSEA < 0.015). Overall, results indicate that CERQ-Ck has similar psychometric properties to the original instrument as well as with adequate reliability and validity to investigate the nine cognitive emotion regulation strategies during late childhood developmental periods. PMID:26925586
Liu, Wen; Chen, Liang; Blue, Philip R
2016-01-01
This study aimed to validate a Chinese's adaption of the Cognitive Emotion Regulation Questionnaire for children (CERQ-Ck). This self-report instrument evaluates nine cognitive emotion regulation strategies that can be used by children after experiencing a negative life event. The CERQ-Ck was evaluated in a sample of 1403 elementary students between the ages of 9 and 11 by using cluster sampling. All the item-correlation coefficients for CERQ-Ck were above 0.30. The internal consistencies of the nine factors suggested moderate reliability (0.66 to 0.73). Confirmatory factor analysis (CFA) indicated that the current version had the same structure as the original instrument (Tucker-Lewis index = 0.912, comparative fit index = 0.922, root mean square error of approximation = 0.032, standardized root mean square residual = 0.044). A second-order factor and a third-order factor structure were also found. Test-retest correlations (0.53 to 0.70, ps < 0.01) over a period of 1 month, which ranged from acceptable to moderately strong were obtained from a random and stratified subsample of elementary students (N = 76). In addition, we analyzed convergent validity in relation to CERQ-Ck and the Chinese version of the Children's Depression Inventory model dimensions with a subsample of 1083 elementary students. Multiple-group CFA confirmed the measurement invariance for both the male and female groups (ΔCFI < 0.01, ΔRMSEA < 0.015). Overall, results indicate that CERQ-Ck has similar psychometric properties to the original instrument as well as with adequate reliability and validity to investigate the nine cognitive emotion regulation strategies during late childhood developmental periods.
Igo, J L; Brooks, J C; Johnson, B J; Starkey, J; Rathmann, R J; Garmyn, A J; Nichols, W T; Hutcheson, J P; Miller, M F
2011-03-01
Anabolic steroid implants are commonly used to increase growth performance and carcass leanness. The objective of this study was to determine the effects of various trenbolone acetate implants on Warner-Bratzler shear force (WBSF), slice shear force, and consumer palatability ratings for USDA Choice and Select beef strip steaks aged for 14 and 21 d from cattle implanted before slaughter. Beef steers (n = 1,740) were subjected to the following treatments: 1) nonimplanted control (CON); 2) Revalor-IS on d 0 and Revalor-S on d 70 (IS/S); or 3) Revalor-XS (RXS) on d 0, and were randomly assigned to pens within blocks. A subsample of USDA Choice (n = 82) and USDA Select (n = 81) carcasses was selected. Strip loins from these carcasses were collected, and steaks measuring 2.54 cm were fabricated and aged for 14 or 21 d postmortem. Select steaks aged 14 d from RXS cattle had decreased (P < 0.05) WBSF values compared with IS/S steaks, but CON steaks did not differ from either implant treatment. Warner-Bratzler shear force did not differ among treatments (P > 0.05) from USDA Choice steaks aged 14 and 21 d or from Select steaks aged 21 d. Consumer scores for flavor and overall liking for USDA Choice 14-d aged RXS steaks were less (P < 0.05) than CON steaks; however, there were no differences between RXS, IS/S, and CON for tenderness or juiciness, or for tenderness and overall acceptability. Select steaks aged 14 d from IS/S cattle had less (P < 0.05) tenderness, tenderness acceptability, overall acceptability, overall liking, juiciness, and flavor scores than RXS and CON steaks; however, consumers also rated RXS steaks less for tenderness, juiciness, and tenderness acceptability when compared with CON steaks. Consumer scores for overall liking, flavor, and tenderness for USDA Choice steaks aged 21 d from RXS, IS/S, and CON did not differ. However, implant affected (P < 0.05) overall liking, flavor, juiciness, and tenderness for USDA Select steaks aged 21 d. Even so, there were no differences between RXS, IS/S, and CON steaks for tenderness or overall acceptability for steaks aged 21 d, regardless of quality grade. Results indicated that tenderness differences exist among implant strategies when strip steaks were aged 14 d; however, tenderness and overall consumer acceptability were only influenced by implant in Select steaks aged 14 d. Furthermore, aging for 21 d can minimize and even eliminate implant differences in WBSF and slice shear force, as well as tenderness and overall consumer acceptability.
Mpundu-Kaambwa, Christine; Chen, Gang; Huynh, Elisabeth; Russo, Remo; Ratcliffe, Julie
2017-09-11
Cerebral palsy is the most common cause of physical disability in children and adolescents and is associated with impairments that may reduce the quality of life (QOL) of this population. Patient-reported outcome measures (PROMs) can facilitate the assessment of the effect of disease and treatment on QOL, from a patient viewpoint. The purpose of this systematic review is to identify PROMs that are used to measure QOL and subjective well-being (SWB) outcomes in young people with cerebral palsy and to evaluate the suitability of these PROMs for application in economic evaluations within this population. MEDLINE, Scopus, the Cochrane Library, Web of Science Core Collection, EconLit, PsycINFO, CINAHL, EMBASE and Informit will be systematically searched from inception to date of search. Published peer-reviewed, English-language articles reporting PROMs measuring QOL or SWB outcomes in children and adolescents with cerebral palsy will be included. One reviewer will conduct the initial search and screen titles and abstracts for potentially eligible studies. The search will be performed in November 2017. To reduce the likelihood of reviewer selection bias, two other reviewers will independently screen a randomly selected subsample (10%) of the citations. Two reviewers will then retrieve full texts of potentially eligible studies and assess them against predefined inclusion criteria. The suitability of selected PROMs for use in economic evaluations of young people with cerebral palsy will be assessed using the International Society of Quality of Life Research recommended Minimum Standards and the Patient-Centered Outcomes and Comparative Effectiveness Research checklist. A narrative synthesis of extracted data will be presented including study descriptive data, PROMs measurement properties, settings in which they were applied and the valuation methods. Recommendations for practice on the selection of PROMs for use in economic evaluations of children and adolescents with cerebral palsy will be presented. Ethical approval is not required as the proposed systematic review will not use primary data. The results of this study will be widely disseminated through publication in a peer-reviewed journal and conference presentation(s). International Prospective Register of Systematic Reviews number: CRD42016049746. © 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.
VizieR Online Data Catalog: Star formation in active and normal galaxies (Tsai+, 2015)
NASA Astrophysics Data System (ADS)
Tsai, M.; Hwang, C.-Y.
2015-11-01
We selected 104 active galaxies from the lists of Melendez et al. (2010MNRAS.406..493M), Condon et al. 1991 (cat. J/ApJ/378/65), and Ho & Ulvestad 2001 (cat. J/ApJS/133/77). Most of the sources are identified as Active Galactic Nuclei (AGNs), and a few of them are classified as Luminous InfraRed Galaxies (LIRGs). We obtained 3.6 and 8μm infrared images of these galaxies from the Spitzer Archive (http://sha.ipac.caltech.edu/applications/Spitzer/SHA/) and 8GHz images from the VLA archive (http://archive.nrao.edu/archive/archiveimage.html). We also selected a nearby AGN sub-sample containing 21 radio-selected AGNs for further spatial analysis. We selected 25 nearby AGNs exhibiting no detected radio emission in order to compare with the results of the radio-selected sources. For comparison, we also selected normal galaxies with distances less than 15Mpc from the catalog of Tully 1994 (see cat. VII/145). We only selected the galaxies that have Spitzer archive data and are not identified as AGNs in either the Veron-Cetty & Veron 2006 (see cat. VII/258) AGN catalog or in the NED database (http://ned.ipac.caltech.edu/). Our results for the radio-selected and the non-radio-selected active galaxies are listed in Table1, and those for the normal galaxies are listed in Table2. (2 data files).
Randomizing Roaches: Exploring the "Bugs" of Randomization in Experimental Design
ERIC Educational Resources Information Center
Wagler, Amy; Wagler, Ron
2014-01-01
Understanding the roles of random selection and random assignment in experimental design is a central learning objective in most introductory statistics courses. This article describes an activity, appropriate for a high school or introductory statistics course, designed to teach the concepts, values and pitfalls of random selection and assignment…
Mobile phone text message reminders: Measuring preferences of people with antipsychotic medication.
Kauppi, Kaisa; Kannisto, Kati A; Hätönen, Heli; Anttila, Minna; Löyttyniemi, Eliisa; Adams, Clive E; Välimäki, Maritta
2015-10-01
Mobile technology use, including Short Messaging Service (SMS) text messaging, has increased in health care services. Preferences regarding the type or timing of text messages sent by healthcare providers to people with antipsychotic medication have not yet been fully investigated. This study examines the relationship between patients' demographic characteristics and the tailored messages they select. The study ("Mobile.Net", 27704027) includes a structured analysis of a random sub-sample of participants who received messages for 12months. The data were collected in 24 sites and 45 psychiatric hospitals in Finland and analyzed with descriptive statistics and Poisson regression models. The study sample involved 562 people on antipsychotic medication, and a total of 2112 text messages (2 to 25 monthly) were analysed. Regarding message content, there was no significant variation in the proportions relating to 'medication', 'treatment appointments' or 'free time'. Monday was the most popular day to receive messages and morning was preferred to later in the day. Age was most closely associated with 'number of messages' and 'time of messages'. Older women and younger men preferred higher numbers of messages (p=0.0031). Participants preferred positive, encouraging and slightly humorous messages. The findings suggest that messages may be acceptable for difficult to access groups in follow-up. This type of intervention may be useful for various types of patients especially for younger males. To further support the evidence about factors related to message utilization and use, it is important to evaluate the effectiveness of text messages in psychiatric care. Copyright © 2015. Published by Elsevier B.V.
A comparison of skeletal maturity assessed by radiological and ultrasonic methods.
Utczas, Katinka; Muzsnai, Agota; Cameron, Noel; Zsakai, Annamaria; Bodzsar, Eva B
2017-07-08
The estimation of skeletal maturity is a useful tool in pediatric practice to determine the degree of delay or advancement in growth disorders and the effectiveness of treatment in conditions that influence linear growth. Skeletal maturity of children is commonly assessed using either Greulich-Pyle (GP) or Tanner-Whitehouse methods (TW2 and TW3). However, a less invasive ultrasonic method, that does not use ionizing radiation, has been suggested for use in epidemiological studies of skeletal maturity. The main purpose of the present study was to determine the accuracy of an ultrasonic method based on the GP maturity indicators compared to the standard GP radiographic method. Skeletal maturity of 1502 healthy children, aged from 6 to 18 years, was estimated by quantitative ultrasound and compared to GP bone ages estimated from left hand and wrist radiographs of a subsample of 47 randomly selected participants. The ultrasonic bone age estimation demonstrated very strong correlations with all the radiological age estimations. The correlation coefficients ranged between 0.895 and 0.958, and the strongest correlation of ultrasonic skeletal maturity estimation was found with the Tanner-Whitehouse RUS method. The ultrasonic bone age estimation is suggested for use between the chronological ages of 8.5-16.0 years in boys and 7.5-15.0 years in girls. The ultrasonic bone age estimation is suggested for use in epidemiological surveys since the sensitivity for screening for not normal bone development is appropriate, at least within the 8-15 years age interval. © 2017 Wiley Periodicals, Inc.
Burgos, Miria Suzana; Burgos, Leandro Tibiriçá; Camargo, Marcelo Dias; Franke, Silvia Isabel Rech; Prá, Daniel; da Silva, Antônio Marcos Vargas; Borges, Tássia Silvana; Todendi, Pâmela Ferreira; Reckziegel, Miriam Beatris; Reuter, Cézane Priscila
2013-01-01
Background Obesity has been identified as an important risk factor in the development of cardiovascular diseases; however, other factors, combined or not with obesity, can influence cardiovascular risk and should be considered in cardiovascular risk stratification in pediatrics. Objective To analyze the association between anthropometry measures and cardiovascular risk factors, to investigate the determinants to changes in blood pressure (BP), and to propose a prediction equation to waist circumference (WC) in children and adolescents. Methods We evaluated 1,950 children and adolescents, aged 7 to 18 years. Visceral fat was assessed by WC and waist hip relationship, BP and body mass index (BMI). In a randomly selected subsample of these volunteers (n = 578), total cholesterol, glucose and triglycerides levels were evaluated. Results WC was positively correlated with BMI (r = 0.85; p < 0.001) and BP (SBP r = 0.45 and DBP = 0.37; p < 0.001). Glycaemia and triglycerides showed a weak correlation with WC (r = 0.110; p = 0.008 e r = 0.201; p < 0.001, respectively). Total cholesterol did not correlate with any of the variables. Age, BMI and WC were significant predictors on the regression models for BP (p < 0.001). We propose a WC prediction equation for children and adolescents: boys: y = 17.243 + 0.316 (height in cm); girls: y = 25.197 + 0.256 (height in cm). Conclusion WC is associated with cardiovascular risk factors and presents itself as a risk factor predictor of hypertension in children and adolescents. The WC prediction equation proposed by us should be tested in future studies. PMID:23979777
Haque, Mohammad Nazmul; Noman, Nasimul; Berretta, Regina; Moscato, Pablo
2016-01-01
Classification of datasets with imbalanced sample distributions has always been a challenge. In general, a popular approach for enhancing classification performance is the construction of an ensemble of classifiers. However, the performance of an ensemble is dependent on the choice of constituent base classifiers. Therefore, we propose a genetic algorithm-based search method for finding the optimum combination from a pool of base classifiers to form a heterogeneous ensemble. The algorithm, called GA-EoC, utilises 10 fold-cross validation on training data for evaluating the quality of each candidate ensembles. In order to combine the base classifiers decision into ensemble's output, we used the simple and widely used majority voting approach. The proposed algorithm, along with the random sub-sampling approach to balance the class distribution, has been used for classifying class-imbalanced datasets. Additionally, if a feature set was not available, we used the (α, β) - k Feature Set method to select a better subset of features for classification. We have tested GA-EoC with three benchmarking datasets from the UCI-Machine Learning repository, one Alzheimer's disease dataset and a subset of the PubFig database of Columbia University. In general, the performance of the proposed method on the chosen datasets is robust and better than that of the constituent base classifiers and many other well-known ensembles. Based on our empirical study we claim that a genetic algorithm is a superior and reliable approach to heterogeneous ensemble construction and we expect that the proposed GA-EoC would perform consistently in other cases.
Pollution gets personal! A first population-based human biomonitoring study in Austria.
Hohenblum, Philipp; Steinbichl, Philipp; Raffesberg, Wolfgang; Weiss, Stefan; Moche, Wolfgang; Vallant, Birgit; Scharf, Sigrid; Haluza, Daniela; Moshammer, Hanns; Kundi, Michael; Piegler, Brigitte; Wallner, Peter; Hutter, Hans-Peter
2012-02-01
Humans are exposed to a broad variety of man-made chemicals. Human biomonitoring (HBM) data reveal the individual body burden irrespective of sources and routes of uptake. A first population-based study was started in Austria in 2008 and was finished at the end of May 2011. This cross sectional study aims at documenting the extent, the distribution and the determinants of human exposure to industrial chemicals as well as proving the feasibility of a representative HBM study. Overall, 150 volunteers (50 families) were selected by stratified random sampling. Exposure to phthalates, trisphosphates, polybrominated diphenyl ethers (PBDE), bisphenol A (along with nonyl- and octyl phenol) and methyl mercury was assessed. Sixteen of 18 PBDE determined were detected above the limit of quantification (LOQ) in blood samples with #153 and #197 the most abundant species. Bisphenol A in urine was measured in a subsample of 25 with only 4 samples found above the LOQ. In 3 of 100 urine samples at least one of 8 trisphosphate compounds assessed was above the LOQ. These first analytical results of the human biomonitoring data show that the body burden of the Austrian population with respect to the assessed compounds is comparable to or even lower than in other European countries. Overall, the study revealed that in order to develop a feasible protocol for representative human biomonitoring studies procedures have to be optimized to allow for non-invasive sampling of body tissues in accordance with the main metabolic pathways. Procedures of participants' recruitment were, however, labor intensive and have to be improved. Copyright © 2011 Elsevier GmbH. All rights reserved.
Haque, Mohammad Nazmul; Noman, Nasimul; Berretta, Regina; Moscato, Pablo
2016-01-01
Classification of datasets with imbalanced sample distributions has always been a challenge. In general, a popular approach for enhancing classification performance is the construction of an ensemble of classifiers. However, the performance of an ensemble is dependent on the choice of constituent base classifiers. Therefore, we propose a genetic algorithm-based search method for finding the optimum combination from a pool of base classifiers to form a heterogeneous ensemble. The algorithm, called GA-EoC, utilises 10 fold-cross validation on training data for evaluating the quality of each candidate ensembles. In order to combine the base classifiers decision into ensemble’s output, we used the simple and widely used majority voting approach. The proposed algorithm, along with the random sub-sampling approach to balance the class distribution, has been used for classifying class-imbalanced datasets. Additionally, if a feature set was not available, we used the (α, β) − k Feature Set method to select a better subset of features for classification. We have tested GA-EoC with three benchmarking datasets from the UCI-Machine Learning repository, one Alzheimer’s disease dataset and a subset of the PubFig database of Columbia University. In general, the performance of the proposed method on the chosen datasets is robust and better than that of the constituent base classifiers and many other well-known ensembles. Based on our empirical study we claim that a genetic algorithm is a superior and reliable approach to heterogeneous ensemble construction and we expect that the proposed GA-EoC would perform consistently in other cases. PMID:26764911
NASA Astrophysics Data System (ADS)
Lamb, Richard L.
2016-02-01
Within the last 10 years, new tools for assisting in the teaching and learning of academic skills and content within the context of science have arisen. These new tools include multiple types of computer software and hardware to include (video) games. The purpose of this study was to examine and compare the effect of computer learning games in the form of three-dimensional serious educational games, two-dimensional online laboratories, and traditional lecture-based instruction in the context of student content learning in science. In particular, this study examines the impact of dimensionality, or the ability to move along the X-, Y-, and Z-axis in the games. Study subjects ( N = 551) were randomly selected using a stratified sampling technique. Independent strata subsamples were developed based upon the conditions of serious educational games, online laboratories, and lecture. The study also computationally models a potential mechanism of action and compares two- and three-dimensional learning environments. F test results suggest a significant difference for the main effect of condition across the factor of content gain score with large effect. Overall, comparisons using computational models suggest that three-dimensional serious educational games increase the level of success in learning as measured with content examinations through greater recruitment and attributional retraining of cognitive systems. The study supports assertions in the literature that the use of games in higher dimensions (i.e., three-dimensional versus two-dimensional) helps to increase student understanding of science concepts.
Sooksawat, Annop; Janwantanakul, Prawit; Tencomnao, Tewin; Pensri, Praneet
2013-01-17
Low back pain (LBP) is common among office workers. A number of studies have established a relationship between Christianity and physical and mental health outcomes among chronic pain patients. The purpose of this study was to examine the relationship between the religious beliefs and practices of Buddhism and disability and psychological stress in office workers with chronic LBP. A cross-sectional survey was conducted with a self-administered questionnaire delivered by hand to 463 office workers with chronic LBP. Saliva samples were collected from a randomly selected sub-sample of respondents (n=96). Disability due to LBP was assessed using the Roland-Morris Disability Questionnaire and psychological stress was assessed based on salivary cortisol. Two hierarchical regression models were built to determine how much variance in disability and psychological stress could be explained by religious beliefs and practices of Buddhism variables after controlling for potential confounder variables. Only 6% of variance in psychological stress was accounted for by the religious beliefs and practices of Buddhism. Those with high religiousness experienced lower psychological stress. No association between the religious beliefs and practices of Buddhism and disability level was found. Depressive symptoms were attributed to both psychological stress and disability status in our study population. The findings suggest that, although being religious may improve the psychological condition in workers with chronic LBP, its effect is insufficient to reduce disability due to illness. Further research should examine the role of depression as a mediator of the effect of psychological stress on disability in patients with chronic LBP.
Bordin, Isabel Altenfelder Santos; Paula, Cristiane Silvestre; do Nascimento, Rosimeire; Duarte, Cristiane Seixas
2006-12-01
To estimate the prevalence of severe physical punishment of children/adolescents in a low-income community, and to examine child mental health problems as a potential correlate. This study is a Brazilian cross-sectional pilot study of the World Studies of Abuse in Family Environments. A probabilistic sample of clusters including all eligible households (women aged 15-49 years, son/daughter < 18 years) was evaluated. One mother-child pair was randomly selected per household (n = 89; attrition = 11%). Outcome (severe physical punishment of children/adolescents by mother/father) was defined as shaking (if age
El-Zein, Mariam; Conus, Florence; Benedetti, Andrea; Parent, Marie-Elise; Rousseau, Marie-Claude
2016-01-01
When using administrative databases for epidemiologic research, a subsample of subjects can be interviewed, eliciting information on undocumented confounders. This article presents a thorough investigation of the validity of a two-stage sample encompassing an assessment of nonparticipation and quantification of the extent of bias. Established through record linkage of administrative databases, the Québec Birth Cohort on Immunity and Health (n = 81,496) aims to study the association between Bacillus Calmette-Guérin vaccination and asthma. Among 76,623 subjects classified in four Bacillus Calmette-Guérin-asthma strata, a two-stage sampling strategy with a balanced design was used to randomly select individuals for interviews. We compared stratum-specific sociodemographic characteristics and healthcare utilization of stage 2 participants (n = 1,643) with those of eligible nonparticipants (n = 74,980) and nonrespondents (n = 3,157). We used logistic regression to determine whether participation varied across strata according to these characteristics. The effect of nonparticipation was described by the relative odds ratio (ROR = ORparticipants/ORsource population) for the association between sociodemographic characteristics and asthma. Parental age at childbirth, area of residence, family income, and healthcare utilization were comparable between groups. Participants were slightly more likely to be women and have a mother born in Québec. Participation did not vary across strata by sex, parental birthplace, or material and social deprivation. Estimates were not biased by nonparticipation; most RORs were below one and bias never exceeded 20%. Our analyses evaluate and provide a detailed demonstration of the validity of a two-stage sample for researchers assembling similar research infrastructures.
He, Ping; Guo, Chao; Luo, Yanan; Wen, Xu; Salas, J M Ian; Chen, Gong; Zheng, Xiaoying
2017-12-01
To investigate trends in rehabilitation services use in children and adolescents with intellectual disabilities, and to explore factors potentially contributing to the trends. A population-based study using a multistage, randomized cluster-sampling process to ascertain participants in 2006. A subsample was selected for follow-up surveys from 2007 to 2013. Thirty-one provinces of China. Children (N=5432) aged 0 to 17 years with intellectual disabilities were followed up for 7 years. Not applicable. The outcome variable was whether individuals received at least 1 of the following rehabilitation services in the past 12 months: occupational therapy, physical therapy, and speech or communication therapy. Overall, the utilization rates of rehabilitation services significantly increased from 14.4% in 2007 to 37.1% in 2013. The trends were also significant in children aged 0 to 10 and 11 to 17 years, in boys and girls, and in rural participants. From 2007 to 2013, rehabilitation services utilization increased at an annual rate of 22.39% (95% confidence interval, 18.11%-26.82%) in the total sample. The rise was only significant in rural rather than urban individuals, resulting in the urban-rural gap in rehabilitation services use being narrowed. However, minority populations and those without health insurance still received fewer rehabilitation services than their respective counterparts. There were upward trends in rehabilitation services use in participants over time, and the urban-rural gap was narrowed. However, there were still socioeconomic differences on rehabilitation services use among children and adolescents with intellectual disabilities. Copyright © 2017. Published by Elsevier Inc.
An infrared-visible image fusion scheme based on NSCT and compressed sensing
NASA Astrophysics Data System (ADS)
Zhang, Qiong; Maldague, Xavier
2015-05-01
Image fusion, as a research hot point nowadays in the field of infrared computer vision, has been developed utilizing different varieties of methods. Traditional image fusion algorithms are inclined to bring problems, such as data storage shortage and computational complexity increase, etc. Compressed sensing (CS) uses sparse sampling without knowing the priori knowledge and greatly reconstructs the image, which reduces the cost and complexity of image processing. In this paper, an advanced compressed sensing image fusion algorithm based on non-subsampled contourlet transform (NSCT) is proposed. NSCT provides better sparsity than the wavelet transform in image representation. Throughout the NSCT decomposition, the low-frequency and high-frequency coefficients can be obtained respectively. For the fusion processing of low-frequency coefficients of infrared and visible images , the adaptive regional energy weighting rule is utilized. Thus only the high-frequency coefficients are specially measured. Here we use sparse representation and random projection to obtain the required values of high-frequency coefficients, afterwards, the coefficients of each image block can be fused via the absolute maximum selection rule and/or the regional standard deviation rule. In the reconstruction of the compressive sampling results, a gradient-based iterative algorithm and the total variation (TV) method are employed to recover the high-frequency coefficients. Eventually, the fused image is recovered by inverse NSCT. Both the visual effects and the numerical computation results after experiments indicate that the presented approach achieves much higher quality of image fusion, accelerates the calculations, enhances various targets and extracts more useful information.
Cook, Elizabeth A; Schneider, Kathleen M; Robinson, Jennifer; Wilwert, June; Chrischilles, Elizabeth; Pendergast, Jane; Brooks, John
2014-09-15
Comparative effectiveness studies using Medicare claims data are vulnerable to treatment selection biases and supplemental data from a sample of patients has been recommended for examining the magnitude of this bias. Previous research using nationwide Medicare claims data has typically relied on the Medicare Current Beneficiary Survey (MCBS) for supplemental data. Because many important clinical variables for our specific research question are not available in the MCBS, we collected medical record data from a subsample of patients to assess the validity of assumptions and to aid in the interpretation of our estimates. This paper seeks to describe and document the process used to collect and validate this supplemental information. Medicare claims data files for all patients with fee-for-service Medicare benefits who had an acute myocardial infarction (AMI) in 2007 or 2008 were obtained. Medical records were obtained and abstracted for a stratified subsample of 1,601 of these patients, using strata defined by claims-based measures of physician prescribing practices and drug treatment combinations. The abstraction tool was developed collaboratively by study clinicians and researchers, leveraging important elements from previously validated tools. Records for 2,707 AMI patients were requested from the admitting hospitals and 1,751 were received for an overall response rate of 65%; 1,601 cases were abstracted by trained personnel at a contracted firm. Data were collected with overall 96% inter-abstractor agreement across all variables. Some non-response bias was detected at the patient and facility level. Although Medicare claims data are a potentially powerful resource for conducting comparative effectiveness analyses, observational databases are vulnerable to treatment selection biases. This study demonstrates that it is feasible to abstract medical records for Medicare patients nationwide and collect high quality data, to design the sampling purposively to address specific research questions, and to more thoroughly evaluate the appropriateness of care delivered to AMI patients.
Optimizing exoplanet transit searches
NASA Astrophysics Data System (ADS)
Herrero, E.; Ribas, I.; Jordi, C.
2013-05-01
Exoplanet searches using the transit technique are nowadays providing a great number of findings. Most exoplanet transit detection programs that are currently underway are focused on large catalogs of stars with no pre-selection. This necessarily makes such surveys quite inefficient, because huge amounts of data are processed for a relatively low transiting planet yield. In this work we investigate a method to increase the efficiency of a targeted exoplanet search with the transit technique by preselecting a subset of candidates from large catalogs of stars. Assuming spin-orbit alignment, this can be done by considering stars that have higher probability to be oriented nearly equator-on (inclination close to 90°). We use activity-rotation velocity relations for low-mass stars to study the dependence of the position in the activity - v sin(i) diagram on the stellar axis inclination. We compose a catalog of G-, K-, M-type main sequence simulated stars using isochrones, an isotropic inclination distribution and empirical relations to obtain their rotation periods and activity indexes. Then the activity-vsini diagram is filled and statistics are applied to trace the areas containing the higher ratio of stars with inclinations above 80°. A similar statistics is applied to stars from real catalogs with log(R'_{HK}) and v sin(i) data to find their probability of being equator-on. We present the method used to generate the simulated star catalog and the subsequent statistics to find the highly inclined stars from real catalogs using the activity-v sin(i) diagram. Several catalogs from the literature are analysed and a subsample of stars with the highest probability of being equator-on is presented. Assuming spin-orbit alignment, the efficiency of an exoplanet transit search in the resulting subsample of probably highly inclined stars is estimated to be two to three times higher than with a global search with no pre-selection.
Cai, Kui-Zheng; Wang, Feng-Hui; Wang, Kang-Ying; Liu, Jun-Lin; Wang, Bo-Bo; Xu, Qiang; Xue, Yu-Jia; Wang, Fan; Zhang, Chao; Fang, Wen-Xiu; Cai, Bin; Liu, Yan-Qiu; Cao, Xin; Ma, Zhong-Ren
2017-06-01
In vitro predatory activity of 157 native isolates of Arthrobotrys oligospora from China on larvae of trichostrongylides (Trichostrongylus colubriformis and Haemonchus contortus) in feces of sheep were assessed. The results showed that 135 of tested isolates of A. oligospora reduced the development of trichostrongylide larvae in feces by 90-99.99%, 11 isolates by 80-89.46% and 11 isolates by 14.58-78.82%. To understand their capacity of passing through gastrointestinal tract of sheep, 50 native isolates of A. oligospora were selected and assessed in sheep. Among these isolates, 16 isolates significantly reduced the number of larvae developing in the feces (P < 0.05); their percentage reduction of L3 ranged from 42.87% to 99.51% and the isolates tested were harvested in 5 g sub-samples of from sheep in each treatment group, indicating that these isolates had the capacity of preying larvae of trichostrongylides after the passage through gastrointestinal tract of sheep. The remaining isolates of A. oligospora were not able to survive after passage through gastrointestinal tract of sheep. In the following, the 16 isolates that presented more or less viability after sheep gastrointestinal passage were selected and assessed in goats. The results showed that the 11 isolates out of them could be able to pass through the digestive tract of goats without loss of ability of preying larvae of trichostrongylides in feces and their efficacies ranged from 53.88% to 94.28%, and that the isolates tested were harvested in 5 g sub-samples of feces from goats in each treatment group. In the current study, these isolates which demonstrated outstanding properties in vitro and could survive in the passage through the alimentary tract of sheep and goat should be potential candidates as a possible feed additive. Copyright © 2017 Elsevier Inc. All rights reserved.
2017-01-01
Design: Observational cross-sectional study. The current study aims to yield normative data: i.e., the physiological standard for 30 selected quantitative 3D parameters that accurately capture and describe a full-skeleton, upright-standing attitude. Specific and exclusive consideration was given to three distinct categories: postural, spine morphology and pelvic parameters. To capture such 3D parameters, the authors selected a non-ionising 3D opto-electronic stereo-photogrammetric approach. This required the identification and measurement of 27 body landmarks, each specifically tagged with a skin marker. As subjects for the measurement of these parameters, a cohort of 124 asymptomatic young adult volunteers was recruited. All parameters were identified and measured within this group. Postural and spine morphology data have been compared between genders. In this regard, only five statistically significant differences were found: pelvis width, pelvis torsion, the “lumbar” lordosis angle value, the lumbar curve length, and the T12-L5 anatomically-bound lumbar angle value. The “thoracic” kyphosis mean angle value was the same in both sexes and, even if, derived from skin markers placed on spinous processes it resulted in perfect agreement with the X-ray based literature. As regards lordosis, a direct comparison was more difficult because methods proposed in the literature differ as to the number and position of vertebrae under consideration, and their related angle values. However, when the L1 superior–L5 inferior end plate Cobb angle was considered, these results aligned strongly with the existing literature. Asymmetry was a standard postural-spinal feature for both sexes. Each subject presented some degree of leg length discrepancy (LLD) with μ = 9.37mm. This was associated with four factors: unbalanced posture and/or underfoot loads, spinal curvature in the frontal plane, and pelvis torsion. This led to the additional study of the effect of LLD equalisation influence on upright posture, relying on a sub-sample of 100 subjects (51 males, 49 females). As a result of the equalisation, about 82% of this sub-sample showed improvement in standing posture, mainly in the frontal plane; while in the sagittal plane less than 1/3 of the sub-sample showed evidence of change in spinal angles. A significant variation was found in relation to pelvis torsion: 46% of subjects showed improvement, 49% worsening. The method described in study presents several advantages: non-invasive aspect; relatively short time for a complete postural evaluation with many clinically useful 3D and 2D anatomical/biomechanical/clinical parameters; analysis of real neutral unconstrained upright standing posture. PMID:28640899
Application of random effects to the study of resource selection by animals
Gillies, C.S.; Hebblewhite, M.; Nielsen, S.E.; Krawchuk, M.A.; Aldridge, Cameron L.; Frair, J.L.; Saher, D.J.; Stevens, C.E.; Jerde, C.L.
2006-01-01
1. Resource selection estimated by logistic regression is used increasingly in studies to identify critical resources for animal populations and to predict species occurrence.2. Most frequently, individual animals are monitored and pooled to estimate population-level effects without regard to group or individual-level variation. Pooling assumes that both observations and their errors are independent, and resource selection is constant given individual variation in resource availability.3. Although researchers have identified ways to minimize autocorrelation, variation between individuals caused by differences in selection or available resources, including functional responses in resource selection, have not been well addressed.4. Here we review random-effects models and their application to resource selection modelling to overcome these common limitations. We present a simple case study of an analysis of resource selection by grizzly bears in the foothills of the Canadian Rocky Mountains with and without random effects.5. Both categorical and continuous variables in the grizzly bear model differed in interpretation, both in statistical significance and coefficient sign, depending on how a random effect was included. We used a simulation approach to clarify the application of random effects under three common situations for telemetry studies: (a) discrepancies in sample sizes among individuals; (b) differences among individuals in selection where availability is constant; and (c) differences in availability with and without a functional response in resource selection.6. We found that random intercepts accounted for unbalanced sample designs, and models with random intercepts and coefficients improved model fit given the variation in selection among individuals and functional responses in selection. Our empirical example and simulations demonstrate how including random effects in resource selection models can aid interpretation and address difficult assumptions limiting their generality. This approach will allow researchers to appropriately estimate marginal (population) and conditional (individual) responses, and account for complex grouping, unbalanced sample designs and autocorrelation.
Application of random effects to the study of resource selection by animals.
Gillies, Cameron S; Hebblewhite, Mark; Nielsen, Scott E; Krawchuk, Meg A; Aldridge, Cameron L; Frair, Jacqueline L; Saher, D Joanne; Stevens, Cameron E; Jerde, Christopher L
2006-07-01
1. Resource selection estimated by logistic regression is used increasingly in studies to identify critical resources for animal populations and to predict species occurrence. 2. Most frequently, individual animals are monitored and pooled to estimate population-level effects without regard to group or individual-level variation. Pooling assumes that both observations and their errors are independent, and resource selection is constant given individual variation in resource availability. 3. Although researchers have identified ways to minimize autocorrelation, variation between individuals caused by differences in selection or available resources, including functional responses in resource selection, have not been well addressed. 4. Here we review random-effects models and their application to resource selection modelling to overcome these common limitations. We present a simple case study of an analysis of resource selection by grizzly bears in the foothills of the Canadian Rocky Mountains with and without random effects. 5. Both categorical and continuous variables in the grizzly bear model differed in interpretation, both in statistical significance and coefficient sign, depending on how a random effect was included. We used a simulation approach to clarify the application of random effects under three common situations for telemetry studies: (a) discrepancies in sample sizes among individuals; (b) differences among individuals in selection where availability is constant; and (c) differences in availability with and without a functional response in resource selection. 6. We found that random intercepts accounted for unbalanced sample designs, and models with random intercepts and coefficients improved model fit given the variation in selection among individuals and functional responses in selection. Our empirical example and simulations demonstrate how including random effects in resource selection models can aid interpretation and address difficult assumptions limiting their generality. This approach will allow researchers to appropriately estimate marginal (population) and conditional (individual) responses, and account for complex grouping, unbalanced sample designs and autocorrelation.
Search for the Higgs boson in lepton, tau, and jets final states
DOE Office of Scientific and Technical Information (OSTI.GOV)
Abazov, V. M.; Abbott, B.; Acharya, B. S.
2013-09-01
We present a search for the standard model Higgs boson in final states with an electron or muon and a hadronically decaying tau lepton in association with two or more jets using 9.7 fb-1 of Run II Fermilab Tevatron Collider data collected with the D0 detector. The analysis is sensitive to Higgs boson production via gluon fusion, associated vector boson production, and vector boson fusion, followed by the Higgs boson decay to tau lepton pairs or to W boson pairs. The ratios of 95% C.L. upper limits on the cross section times branching ratio to those predicted by the standardmore » model are obtained for orthogonal subsamples that are enriched in either H → τ τ decays or H → WW decays, and for the combination of these subsample limits. The observed and expected limit ratios for the combined subsamples at a Higgs boson mass of 125 GeV are 11.3 and 9.0 respectively.« less
Low energy atmospheric muon neutrinos in MACRO
NASA Astrophysics Data System (ADS)
Ambrosio, M.; Antolini, R.; Auriemma, G.; Bakari, D.; Baldini, A.; Barbarino, G. C.; Barish, B. C.; Battistoni, G.; Bellotti, R.; Bemporad, C.; Bernardini, P.; Bilokon, H.; Bisi, V.; Bloise, C.; Bower, C.; Brigida, M.; Bussino, S.; Cafagna, F.; Calicchio, M.; Campana, D.; Carboni, M.; Cecchini, S.; Cei, F.; Chiarella, V.; Choudhary, B. C.; Coutu, S.; De Cataldo, G.; Dekhissi, H.; De Marzo, C.; De Mitri, I.; Derkaoui, J.; De Vincenzi, M.; Di Credico, A.; Erriquez, O.; Favuzzi, C.; Forti, C.; Fusco, P.; Giacomelli, G.; Giannini, G.; Giglietto, N.; Giorgini, M.; Grassi, M.; Gray, L.; Grillo, A.; Guarino, F.; Gustavino, C.; Habig, A.; Hanson, K.; Heinz, R.; Iarocci, E.; Katsavounidis, E.; Katsavounidis, I.; Kearns, E.; Kim, H.; Kyriazopoulou, S.; Lamanna, E.; Lane, C.; Levin, D. S.; Lipari, P.; Longley, N. P.; Longo, M. J.; Loparco, F.; Maaroufi, F.; Mancarella, G.; Mandrioli, G.; Margiotta, A.; Marini, A.; Martello, D.; Marzari-Chiesa, A.; Mazziotta, M. N.; Michael, D. G.; Mikheyev, S.; Miller, L.; Monacelli, P.; Montaruli, T.; Monteno, M.; Mufson, S.; Musser, J.; Nicolò, D.; Nolty, R.; Orth, C.; Osteria, G.; Ouchrif, M.; Palamara, O.; Patera, V.; Patrizii, L.; Pazzi, R.; Peck, C. W.; Perrone, L.; Petrera, S.; Pistilli, P.; Popa, V.; Rainò, A.; Reynoldson, J.; Ronga, F.; Satriano, C.; Satta, L.; Scapparone, E.; Scholberg, K.; Sciubba, A.; Serra, P.; Sioli, M.; Sirri, G.; Sitta, M.; Spinelli, P.; Spinetti, M.; Spurio, M.; Steinberg, R.; Stone, J. L.; Sulak, L. R.; Surdo, A.; Tarlè, G.; Togo, V.; Vakili, M.; Vilela, E.; Walter, C. W.; Webb, R.
2000-04-01
We present the measurement of two event samples induced by atmospheric νμ of average energy
Silva, Veronica; Loredo, Jorge; Fernández-Martínez, Rodolfo; Larios, Raquel; Ordóñez, Almudena; Gómez, Belén; Rucandio, Isabel
2014-10-01
Tailings from abandoned mercury mines represent an important pollution source by metals and metalloids. Mercury mining in Asturias (north-western Spain) has been carried out since Roman times until the 1970s. Specific and non-specific arsenic minerals are present in the paragenesis of the Hg ore deposit. As a result of intensive mining operations, waste materials contain high concentrations of As, which can be geochemically dispersed throughout surrounding areas. Arsenic accumulation, mobility and availability in soils and sediments are strongly affected by the association of As with solid phases and granular size composition. The objective of this study was to examine phase associations of As in the fine grain size subsamples of mine wastes (La Soterraña mine site) and stream sediments heavily affected by acid mine drainage (Los Rueldos mine site). An arsenic-selective sequential procedure, which categorizes As content into seven phase associations, was applied. In spite of a higher As accumulation in the finest particle-size subsamples, As fractionation did not seem to depend on grain size since similar distribution profiles were obtained for the studied granulometric fractions. The presence of As was relatively low in the most mobile forms in both sites. As was predominantly linked to short-range ordered Fe oxyhydroxides, coprecipitated with Fe and partially with Al oxyhydroxides and associated with structural material in mine waste samples. As incorporated into short-range ordered Fe oxyhydroxides was the predominant fraction at sediment samples, representing more than 80% of total As.
Kiluk, Brian D; Serafini, Kelly; Malin-Mayor, Bo; Babuscio, Theresa A; Nich, Charla; Carroll, Kathleen M
2015-04-01
A substantial portion of individuals entering treatment for substance use have been referred by the criminal justice system, yet there are conflicting reports regarding treatment engagement and outcome differences compared to those not referred. This study examined baseline characteristic and treatment outcome differences among cocaine-dependent individuals participating in cocaine treatment randomized trials. This secondary analysis pooled samples across five completed randomized controlled trials, resulting in 434 participants. Of these, 67 (15%) were prompted to treatment by the criminal justice system. This subsample of criminal justice prompted (CJP) individuals did not differ from those not prompted by the criminal justice system in terms of gender, race/ethnicity, marital status, or age. However, the CJP group reported more years of regular cocaine use, more severe employment and legal problems, as well as less readiness to change prior to treatment. Treatment outcomes did not differ significantly from those without a criminal justice prompt, and on some measures the outcomes for CJP group were better (e.g., percentage of days cocaine abstinent, number of therapy sessions attended). These findings suggest that being prompted to treatment by the criminal justice system may not lead to poorer treatment engagement or substance use outcomes for individuals participating in randomized controlled treatment trials. Despite some baseline indicators of poorer treatment prognosis, individuals who have been prompted to treatment by the criminal justice system have similar treatment outcomes as those presenting to treatment voluntarily. © American Academy of Addiction Psychiatry.
Ross, Lesley A; Edwards, Jerri D; O'Connor, Melissa L; Ball, Karlene K; Wadley, Virginia G; Vance, David E
2016-01-01
Multilevel models assessed the effects of cognitive speed of processing training (SPT) on older adults' self-reported driving using intention-to-treat (ITT, randomization to training or control conditions) and dosage (treatment-received via number of training sessions) analyses across 5 years. Participants randomized to SPT (n = 598) were compared with those randomized to either the no-contact control (n = 598) or memory training, which served as an active control (n = 610). Driving mobility (frequency, exposure, and space) was assessed over time. No significant effects were found within the ITT analyses. However, number of SPT sessions did affect driving mobility outcomes. In the full sample (N = 1,806), higher SPT doses were associated with maintained driving frequency as compared with both control groups, but no effects were found for driving exposure or space. Subsample analyses (n = 315) revealed that persons at-risk for mobility declines (i.e., poor initial processing speed) who received additional booster SPT sessions reported greater maintenance of both driving frequency and exposure over time as compared with the no-contact and active control groups. These results and prior research indicate that cognitive SPT transfers to prolonged driving mobility among older adults. Future research should investigate the mechanisms behind transfer effects to real-world activities, such as driving. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
NASA Astrophysics Data System (ADS)
Gill, Andrew B.; Black, Richard T.; Bowden, David J.; Priest, Andrew N.; Graves, Martin J.; Lomas, David J.
2014-06-01
This study investigated the effect of temporal resolution on the dual-input pharmacokinetic (PK) modelling of dynamic contrast-enhanced MRI (DCE-MRI) data from normal volunteer livers and from patients with hepatocellular carcinoma. Eleven volunteers and five patients were examined at 3 T. Two sections, one optimized for the vascular input functions (VIF) and one for the tissue, were imaged within a single heart-beat (HB) using a saturation-recovery fast gradient echo sequence. The data was analysed using a dual-input single-compartment PK model. The VIFs and/or uptake curves were then temporally sub-sampled (at interval ▵t = [2-20] s) before being subject to the same PK analysis. Statistical comparisons of tumour and normal tissue PK parameter values using a 5% significance level gave rise to the same study results when temporally sub-sampling the VIFs to HB < ▵t <4 s. However, sub-sampling to ▵t > 4 s did adversely affect the statistical comparisons. Temporal sub-sampling of just the liver/tumour tissue uptake curves at ▵t ≤ 20 s, whilst using high temporal resolution VIFs, did not substantially affect PK parameter statistical comparisons. In conclusion, there is no practical advantage to be gained from acquiring very high temporal resolution hepatic DCE-MRI data. Instead the high temporal resolution could be usefully traded for increased spatial resolution or SNR.
Shah, Syed M; Loney, Tom; Dhaheri, Salma Al; Vatanparast, Hassan; Elbarazi, Iffat; Agarwal, Mukesh; Blair, Iain; Ali, Raghib
2015-02-28
Approximately 65% of the United Arab Emirates (UAE) population are economic migrants from the low- and middle-income countries of South Asia. Emerging evidence suggests that expatriate populations from low or middle-income countries that migrate to high-income countries acculturate their lifestyle with the obesogenic behaviours of the host country. Previous research has focussed on migrant populations in the United States. The objective of this study was to assess the prevalence of obesity and explore the relationship between years of residency (surrogate measure for acculturation) and obesity among South Asian (from India, Pakistan and Bangladesh) male immigrants residing in the UAE. A random sample of 1375 males was recruited from a mandatory residency visa health screening centre in Abu Dhabi (UAE). Employing a cross-sectional design, participants completed an interviewer-led adapted version of the World Health Organisation STEPS questionnaire, and anthropometric and blood pressure measurements were collected. Glycated haemoglobin (HbA1c) was measured in a random sub-sample (n = 100). Logistic regression was used to determine risk factors for being classified as obese, and to assess the relationship between years of residency and adiposity. The overall prevalence of body mass index-derived overweight and obesity estimates and waist-to-hip-derived central obesity rates was 615 (44.7%) and 917 (66.7%) males, respectively. Hypertension was present in 419 (30.5%) of the sample and diabetes in 9 (9.0%) of the sub-sample. Living in the UAE for six to 10 years or more than 10 years was independently associated with being classified with central obesity (adjusted odds ratio [AOR] 1.63 95% confidence intervals [CI] 1.13 - 2.35, p < 0.008; AOR 1.95 95% CI 1.26 - 3.01, p < 0.002; respectively) compared to residing in the UAE for one to five years. Our study revealed a high prevalence of overweight, central obesity and hypertension amongst a young South Asian male migrant population in the UAE. Study findings suggest a diminished 'Healthy Migrant Effect' with increased years of residency possibly due to greater acculturation and a transition in lifestyle behaviours. Health initiatives targeting the maintenance of a healthy body size, coupled with regular assessments of glucose control and blood pressure are urgently required in this population.
2014-01-01
Introduction Prolonged ventilation and failed extubation are associated with increased harm and cost. The added value of heart and respiratory rate variability (HRV and RRV) during spontaneous breathing trials (SBTs) to predict extubation failure remains unknown. Methods We enrolled 721 patients in a multicenter (12 sites), prospective, observational study, evaluating clinical estimates of risk of extubation failure, physiologic measures recorded during SBTs, HRV and RRV recorded before and during the last SBT prior to extubation, and extubation outcomes. We excluded 287 patients because of protocol or technical violations, or poor data quality. Measures of variability (97 HRV, 82 RRV) were calculated from electrocardiogram and capnography waveforms followed by automated cleaning and variability analysis using Continuous Individualized Multiorgan Variability Analysis (CIMVA™) software. Repeated randomized subsampling with training, validation, and testing were used to derive and compare predictive models. Results Of 434 patients with high-quality data, 51 (12%) failed extubation. Two HRV and eight RRV measures showed statistically significant association with extubation failure (P <0.0041, 5% false discovery rate). An ensemble average of five univariate logistic regression models using RRV during SBT, yielding a probability of extubation failure (called WAVE score), demonstrated optimal predictive capacity. With repeated random subsampling and testing, the model showed mean receiver operating characteristic area under the curve (ROC AUC) of 0.69, higher than heart rate (0.51), rapid shallow breathing index (RBSI; 0.61) and respiratory rate (0.63). After deriving a WAVE model based on all data, training-set performance demonstrated that the model increased its predictive power when applied to patients conventionally considered high risk: a WAVE score >0.5 in patients with RSBI >105 and perceived high risk of failure yielded a fold increase in risk of extubation failure of 3.0 (95% confidence interval (CI) 1.2 to 5.2) and 3.5 (95% CI 1.9 to 5.4), respectively. Conclusions Altered HRV and RRV (during the SBT prior to extubation) are significantly associated with extubation failure. A predictive model using RRV during the last SBT provided optimal accuracy of prediction in all patients, with improved accuracy when combined with clinical impression or RSBI. This model requires a validation cohort to evaluate accuracy and generalizability. Trial registration ClinicalTrials.gov NCT01237886. Registered 13 October 2010. PMID:24713049
Partial psychic seizures and brain organization.
Ardila, A; Montañes, P; Bernal, B; Serpa, A; Ruiz, E
1986-08-01
This research was an attempt to determine the cerebral areas involved in focal epileptic seizures accompanied by psychic manifestations. Six types of partial seizures involving psychic symptomatology and phonatory seizures were included in the study. Sixty-one clinical records of focal epilepsy, which had been revealed by means of a CT-scan examination, were analyzed and a subsample of 25 patients with psychic symptoms was selected. The scans taken of the lesions were transferred to a six-level standard template built for this purpose. Subsequently, templates of patients with the same type of seizures were superimposed. The critical zones for the seven types of seizures studied are presented. A clear correlation was found between these results and our present knowledge of functional brain organization.
VizieR Online Data Catalog: Tully-Fisher relation for SDSS galaxies (Reyes+, 2011)
NASA Astrophysics Data System (ADS)
Reyes, R.; Mandelbaum, R.; Gunn, J. E.; Pizagno, J.; Lackner, C. N.
2012-05-01
In this paper, we derive scaling relations between photometric observable quantities and disc galaxy rotation velocity Vrot or Tully-Fisher relations (TFRs). Our methodology is dictated by our purpose of obtaining purely photometric, minimal-scatter estimators of Vrot applicable to large galaxy samples from imaging surveys. To achieve this goal, we have constructed a sample of 189 disc galaxies at redshifts z<0.1 with long-slit Hα spectroscopy from Pizagno et al. (2007, Cat. J/AJ/134/945) and new observations. By construction, this sample is a fair subsample of a large, well-defined parent disc sample of ~170000 galaxies selected from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7). (4 data files).
VizieR Online Data Catalog: SEDs of the radio continuum from KINGFISHER (Tabatabaei+, 2017)
NASA Astrophysics Data System (ADS)
Tabatabaei, F. S.; Schinnerer, E.; Krause, M.; Dumas, G.; Meidt, S.; Damas-Segovia, A.; Beck, R.; Murphy, E. J.; Mulcahy, D. D.; Groves, B.; Bolatto, A.; Dale, D.; Galametz, M.; Sandstrom, K.; Boquien, M.; Calzetti, D.; Kennicutt, R. C.; Hunt, L. K.; de Looze, I.; Pellegrini, E. W.
2017-10-01
The KINGFISH sample consists of 61 nearby galaxies of different morphological types. From this sample, we selected all galaxies with declinations >=-21° and named this subsample KINGFISHER (KINGFISH galaxies Emitting in Radio). These galaxies can be observed with the Effelsberg 100m single-dish telescope to obtain global measurements of the radio continuum at 20cm, 6cm, and 3.6cm. The non-KINGFISH galaxy, M51, is also included in this study. We observed 35 of these galaxies at 6cm, 10 galaxies at 20cm, and 7 at 3.6cm to complete already existing archival data during four observation runs (2008 Dec, 2009 Dec, 2010 Apr and 2010 Dec & 2012 Mar). (3 data files).
Vinall, Jillian; Pillai Riddell, Rebecca; Greenberg, Saul
2011-01-01
OBJECTIVE: To investigate how maternal culture (ie, individualist versus collectivist) influences soothing techniques and infant distress. METHODS: Archival data were analyzed using a subsample of 80 mother-infant dyads selected from a larger database of infant pain expression. RESULTS: Mothers belonging to the individualist group used more affection behaviours when attempting to regulate their infants’ distress. No differences were observed in mothers’ touching, holding, rocking, vocalizing, caregiving or distracting their infants. Mothers’ culture did not appear to be related to the level of distress expressed by their infants. CONCLUSIONS: These results suggest that the similarities in soothing and infant pain expression between individualist and collectivist cultures are more prominent than their differences. PMID:22059192
NASA Astrophysics Data System (ADS)
Merkenschlager, Christian; Hertig, Elke; Jacobeit, Jucundus
2017-04-01
In the context of analyzing temporal varying relationships of heavy precipitation events in the Mediterranean area and associated anomalies of the large-scale circulation, quantile regression models were established. The models were calibrated using different circulation and thermodynamic variables at the 700 hPa and 850 hPa levels as predictors as well as daily precipitation time series at different stations in the Mediterranean area as predictand. Analyses were done for the second half of the 20th century. In the scope of assessing non-stationarities in the predictor-predictand relationships the time series were divided into calibration and validation periods. 100 randomized subsamples were used to calibrate/validate the models under stationary conditions. The highest and lowest skill score of the 100 random samples was used to determine the range of random variability. The model performance under non-stationary conditions was derived from the skill scores of cross-validated running subintervals. If the skill scores of several consecutive years are outside the range of random variability a non-stationarity was declaimed. Particularly the Iberian Peninsula and the Levant region were affected by non-stationarities, the former with significant positive deviations of the skill scores, the latter with significant negative deviations. By means of a case study for the Levant region we determined three possible reasons for non-stationary behavior in the predictor-predictand relationships. The Mediterranean Oscillation as a superordinate system affects the cyclone activity in the Mediterranean basin and the location and intensity of the Cyprus low. Overall, it is demonstrated that non-stationarities have to be taken into account within statistical downscaling model development.
Genetic programming based ensemble system for microarray data classification.
Liu, Kun-Hong; Tong, Muchenxuan; Xie, Shu-Tong; Yee Ng, Vincent To
2015-01-01
Recently, more and more machine learning techniques have been applied to microarray data analysis. The aim of this study is to propose a genetic programming (GP) based new ensemble system (named GPES), which can be used to effectively classify different types of cancers. Decision trees are deployed as base classifiers in this ensemble framework with three operators: Min, Max, and Average. Each individual of the GP is an ensemble system, and they become more and more accurate in the evolutionary process. The feature selection technique and balanced subsampling technique are applied to increase the diversity in each ensemble system. The final ensemble committee is selected by a forward search algorithm, which is shown to be capable of fitting data automatically. The performance of GPES is evaluated using five binary class and six multiclass microarray datasets, and results show that the algorithm can achieve better results in most cases compared with some other ensemble systems. By using elaborate base classifiers or applying other sampling techniques, the performance of GPES may be further improved.
Genetic Programming Based Ensemble System for Microarray Data Classification
Liu, Kun-Hong; Tong, Muchenxuan; Xie, Shu-Tong; Yee Ng, Vincent To
2015-01-01
Recently, more and more machine learning techniques have been applied to microarray data analysis. The aim of this study is to propose a genetic programming (GP) based new ensemble system (named GPES), which can be used to effectively classify different types of cancers. Decision trees are deployed as base classifiers in this ensemble framework with three operators: Min, Max, and Average. Each individual of the GP is an ensemble system, and they become more and more accurate in the evolutionary process. The feature selection technique and balanced subsampling technique are applied to increase the diversity in each ensemble system. The final ensemble committee is selected by a forward search algorithm, which is shown to be capable of fitting data automatically. The performance of GPES is evaluated using five binary class and six multiclass microarray datasets, and results show that the algorithm can achieve better results in most cases compared with some other ensemble systems. By using elaborate base classifiers or applying other sampling techniques, the performance of GPES may be further improved. PMID:25810748
Alyanak, Behiye; Kılınçaslan, Ayşe; Harmancı, Halime Sözen; Demirkaya, Sevcan Karakoç; Yurtbay, Tülin; Vehid, Hayriye Ertem
2013-01-01
The present study investigated emotional and behavioral problems in children with selective mutism (SM) along with the psychological adjustment and parenting attitudes of their mothers and fathers. Participants included 26 children with SM (mean age = 8.11 ± 2.11 years), 32 healthy controls (mean age = 8.18 ± 2.55 years) and the parents of all children. Children with SM displayed higher problem scores than controls in a variety of emotional and behavioral parameters. They predominantly displayed internalizing problems, whereas aggressive and delinquent behavior was described among a subsample of the children. Significant differences existed between the SM and control groups only in paternal psychopathology, which included anxiety and depression. They did not differ with respect to maternal psychological distress or mother or father reported parental attitudes. Another important result of the present study was that the severity of emotional and behavioral problems of children with SM was correlated with maternal psychopathology but not paternal psychopathology. Copyright © 2012 Elsevier Ltd. All rights reserved.
García-Campayo, Javier; Del Hoyo, Yolanda L; Barceló-Soler, Alberto; Navarro-Gil, Mayte; Borao, Luis; Giarin, Veronica; Tovar-Garcia, R Raziel; Montero-Marin, Jesus
2018-01-01
Introduction: Personal wisdom has demonstrated important implications for the health of individuals. The aim of the present study was to validate a Spanish version of the Three-Dimensional Wisdom Scale (3D-WS), exploring the structure of a possible general factor, and assessing its explanatory power on psychological health-related variables. Methods: A cross-sectional study design was used, with a total sample of 624 Spanish participants recruited on the Internet and randomly split into two halves. The following instruments were applied: 3D-WS, Purpose in Life (PIL), Multidimensional State Boredom Scale (MSBS), Positive and Negative Affect Scale (PANAS), and Difficulties in Emotion Regulation Scale (DERS). Factorial structures were analyzed through exploratory and confirmatory factor analysis (EFA and CFA), and the general factor was characterized by using bifactor models. The explanatory power of the 3D-WS was established by multiple regression. Results: The original long and short versions of the 3D-WS were not replicated in the first subsample using EFA, and there was a high rate of cross-loadings. Thus, a new short 3D-WS was proposed by ordering the original items according to factorial weights. This three-correlated-factor (reflective, cognitive, and affective) proposal was tested by means of CFA in the second subsample, with adequate psychometrics and invariance, and a good fit (χ 2 /df = 1.98; CFI = 0.946; RMSEA = 0.056; 90% CI = 0.040-0.072). A bifactor structure, in which the reflective trait of wisdom was integrated into a general factor (G-Reflective) improved the model fit (χ 2 /df = 1.85; CFI = 0.959; RMSEA = 0.052; 90% CI = 0.035-0.070). The explained common variance of G-Reflective was 0.53; therefore, the new short 3D-WS should not be considered essentially unidimensional. The new short 3D-WS showed positive relationships with the PIL and PANAS-positive, and negative associations with the MSBS, PANAS-negative and DERS, contributing to explain all the referred variables. These results were consistent across subsamples. Conclusion: The new short 3D-WS appears to be a reliable instrument for measuring wisdom in the Spanish general population. The reflective facet might influence the cognitive and affective wisdom components through the G-Reflective general factor. There seems to be a high explanatory power of the 3D-WS on psychological health-related variables. This study will facilitate the development of future research and psychological knowledge regarding wisdom.
Guardone, L; Nucera, D; Pergola, V; Costanzo, F; Costa, E; Tinacci, L; Guidi, A; Armani, A
2017-06-05
The European anchovy (Engraulis encrasicolus), one of the most important pelagic fish resources in the Mediterranean Sea, is frequently infected by anisakid larvae. Food Business Operators (FBOs) should use appropriate sampling plans and analytical methods to avoid commercialization of massively infected batches and reduce the risk of transmission of viable zoonotic larvae. In this study, performed at FishLab (Department of Veterinary Sciences of the University of Pisa) during 2016, an official sampling plan was associated with a digestion protocol for the inspection of anchovies. Considering that anisakid larvae are usually located in the fish visceral cavity and in the adjacent muscles (VM), this part was analyzed. In particular, we assessed the reliability of the digestion of a subsample of 150g (±30g) of VM, randomly collected from 29 specimens, in estimating the marketability of the anchovies' batch. Fifty-seven samples of 29 anchovies were collected. Each anchovy was sectioned to separate VM. All the subsamples were digested, and visible larvae counted. A high correlation between the number of larvae in VM regions and in the total batch was observed, indicating a very significant contribution of the VM region on total number of parasites. The Mean Abundance (MA) was used to assess the batch marketability according to a threshold calculated on the basis of the maximum number of nematodes tolerated per sample. Considering that the MA can be calculated only when the number of examined specimens is known, the number of visible Larvae per gram of tissue (LpG) was calculated on 150g (±30g) of VM subsamples. A LpG marketability threshold was calculated dividing the maximum number of tolerated nematodes by the average weight of a sample of 29 anchovies calculated considering data available in literature. To evaluate the diagnostic performance of the LpG threshold, the marketability of 57 batches assessed on the basis of the MA threshold was assumed as the gold standard. The proposed LpG showed very high Specificity and Sensitivity. These findings suggest that the analysis of VM is representative of the overall infestation of the batch, both when considering the absolute number of parasites and the LpG, and may represent a valid alternative to the whole anchovy digestion. In particular, the use of an automated digestive method, coupled with the aforesaid sampling plan, could allow the procedure to be used by FBOs in operational conditions. Copyright © 2017 Elsevier B.V. All rights reserved.
Demaerschalk, Bart M; Brown, Robert D; Roubin, Gary S; Howard, Virginia J; Cesko, Eldina; Barrett, Kevin M; Longbottom, Mary E; Voeks, Jenifer H; Chaturvedi, Seemant; Brott, Thomas G; Lal, Brajesh K; Meschia, James F; Howard, George
2017-09-01
Multicenter clinical trials attempt to select sites that can move rapidly to randomization and enroll sufficient numbers of patients. However, there are few assessments of the success of site selection. In the CREST-2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trials), we assess factors associated with the time between site selection and authorization to randomize, the time between authorization to randomize and the first randomization, and the average number of randomizations per site per month. Potential factors included characteristics of the site, specialty of the principal investigator, and site type. For 147 sites, the median time between site selection to authorization to randomize was 9.9 months (interquartile range, 7.7, 12.4), and factors associated with early site activation were not identified. The median time between authorization to randomize and a randomization was 4.6 months (interquartile range, 2.6, 10.5). Sites with authorization to randomize in only the carotid endarterectomy study were slower to randomize, and other factors examined were not significantly associated with time-to-randomization. The recruitment rate was 0.26 (95% confidence interval, 0.23-0.28) patients per site per month. By univariate analysis, factors associated with faster recruitment were authorization to randomize in both trials, principal investigator specialties of interventional radiology and cardiology, pre-trial reported performance >50 carotid angioplasty and stenting procedures per year, status in the top half of recruitment in the CREST trial, and classification as a private health facility. Participation in StrokeNet was associated with slower recruitment as compared with the non-StrokeNet sites. Overall, selection of sites with high enrollment rates will likely require customization to align the sites selected to the factor under study in the trial. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02089217. © 2017 American Heart Association, Inc.
Does brain creatine content rely on exogenous creatine in healthy youth? A proof-of-principle study.
Merege-Filho, Carlos Alberto Abujabra; Otaduy, Maria Concepción Garcia; de Sá-Pinto, Ana Lúcia; de Oliveira, Maira Okada; de Souza Gonçalves, Lívia; Hayashi, Ana Paula Tanaka; Roschel, Hamilton; Pereira, Rosa Maria Rodrigues; Silva, Clovis Artur; Brucki, Sonia Maria Dozzi; da Costa Leite, Claudia; Gualano, Bruno
2017-02-01
It has been hypothesized that dietary creatine could influence cognitive performance by increasing brain creatine in developing individuals. This double-blind, randomized, placebo-controlled, proof-of-principle study aimed to investigate the effects of creatine supplementation on cognitive function and brain creatine content in healthy youth. The sample comprised 67 healthy participants aged 10 to 12 years. The participants were given creatine or placebo supplementation for 7 days. At baseline and after the intervention, participants undertook a battery of cognitive tests. In a random subsample of participants, brain creatine content was also assessed in the regions of left dorsolateral prefrontal cortex, left hippocampus, and occipital lobe by proton magnetic resonance spectroscopy (1H-MRS) technique. The scores obtained from verbal learning and executive functions tests did not significantly differ between groups at baseline or after the intervention (all p > 0.05). Creatine content was not significantly different between groups in left dorsolateral prefrontal cortex, left hippocampus, and occipital lobe (all p > 0.05). In conclusion, a 7-day creatine supplementation protocol did not elicit improvements in brain creatine content or cognitive performance in healthy youth, suggesting that this population mainly relies on brain creatine synthesis rather than exogenous creatine intake to maintain brain creatine homeostasis.
Shawyer, Frances; Farhall, John; Mackinnon, Andrew; Trauer, Tom; Sims, Eliza; Ratcliff, Kirk; Larner, Chris; Thomas, Neil; Castle, David; Mullen, Paul; Copolov, David
2012-02-01
Command hallucinations represent a special problem for the clinical management of psychosis. While compliance with both non-harmful and harmful commands can be problematic, sometimes in the extreme, active efforts to resist commands may also contribute to their malignancy. Previous research suggests Cognitive Behaviour Therapy (CBT) to be a useful treatment for reducing compliance with harmful command hallucinations. The purpose of this trial was to evaluate whether CBT augmented with acceptance-based strategies from Acceptance and Commitment Therapy could more broadly reduce the negative impact of command hallucinations. Forty-three participants with problematic command hallucinations were randomized to receive 15 sessions of the intervention "TORCH" (Treatment of Resistant Command Hallucinations) or the control, Befriending, then followed up for 6 months. A sub-sample of 17 participants was randomized to a waitlist control before being allocated to TORCH or Befriending. Participants engaged equally well with both treatments. Despite TORCH participants subjectively reporting greater improvement in command hallucinations compared to Befriending participants, the study found no significant group differences in primary and secondary outcome measures based on blinded assessment data. Within-group analyses and comparisons between the combined treatments and waitlist suggested, however, that both treatments were beneficial with a differential pattern of outcomes observed across the two conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.
What contributes to perceived stress in later life? A recursive partitioning approach.
Scott, Stacey B; Jackson, Brenda R; Bergeman, C S
2011-12-01
One possible explanation for the individual differences in outcomes of stress is the diversity of inputs that produce perceptions of being stressed. The current study examines how combinations of contextual features (e.g., social isolation, neighborhood quality, health problems, age discrimination, financial concerns, and recent life events) of later life contribute to overall feelings of stress. Recursive partitioning techniques (regression trees and random forests) were used to examine unique interrelations between predictors of perceived stress in a sample of 282 community-dwelling adults. Trees provided possible examples of equifinality (i.e., subsets of people with similar levels of perceived stress but different predictors) as well as identification both of contextual combinations that separated participants with very high and very low perceived stress. Random forest analyses aggregated across many trees based on permuted versions of the data and predictors; loneliness, financial strain, neighborhood strain, ageism, and to some extent life events emerged as important predictors. Interviews with a subsample of participants provided both thick description of the complex relationships identified in the trees, as well as additional risks not appearing in the survey results. Together, the analyses highlight what may be missed when stress is used as a simple unidimensional construct and can guide differential intervention efforts.
What contributes to perceived stress in later life? A recursive partitioning approach
Scott, Stacey B.; Jackson, Brenda R.; Bergeman, C. S.
2011-01-01
One possible explanation for the individual differences in outcomes of stress is the diversity of inputs that produce perceptions of being stressed. The current study examines how combinations of contextual features (e.g., social isolation, neighborhood quality, health problems, age discrimination, financial concerns, and recent life events) of later life contribute to overall feelings of stress. Recursive partitioning techniques (regression trees and random forests) were used to examine unique interrelations between predictors of perceived stress in a sample of 282 community-dwelling adults. Trees provided possible examples of equifinality (i.e., subsets of people with similar levels of perceived stress but different predictors) as well as for the identification both of contextual combinations that separated participants with very high and very low perceived stress. Random forest analyses aggregated across many trees based on permuted versions of the data and predictors; loneliness, financial strain, neighborhood strain, ageism, and to some extent life events emerged as important predictors. Interviews with a subsample of participants provided both thick description of the complex relationships identified in the trees, as well as additional risks not appearing in the survey results. Together, the analyses highlight what may be missed when stress is used as a simple unidimensional construct and can guide differential intervention efforts. PMID:21604885
Accelerated 2D magnetic resonance spectroscopy of single spins using matrix completion
NASA Astrophysics Data System (ADS)
Scheuer, Jochen; Stark, Alexander; Kost, Matthias; Plenio, Martin B.; Naydenov, Boris; Jelezko, Fedor
2015-12-01
Two dimensional nuclear magnetic resonance (NMR) spectroscopy is one of the major tools for analysing the chemical structure of organic molecules and proteins. Despite its power, this technique requires long measurement times, which, particularly in the recently emerging diamond based single molecule NMR, limits its application to stable samples. Here we demonstrate a method which allows to obtain the spectrum by collecting only a small fraction of the experimental data. Our method is based on matrix completion which can recover the full spectral information from randomly sampled data points. We confirm experimentally the applicability of this technique by performing two dimensional electron spin echo envelope modulation (ESEEM) experiments on a two spin system consisting of a single nitrogen vacancy (NV) centre in diamond coupled to a single 13C nuclear spin. The signal to noise ratio of the recovered 2D spectrum is compared to the Fourier transform of randomly subsampled data, where we observe a strong suppression of the noise when the matrix completion algorithm is applied. We show that the peaks in the spectrum can be obtained with only 10% of the total number of the data points. We believe that our results reported here can find an application in all types of two dimensional spectroscopy, as long as the measured matrices have a low rank.
The mental health of UK Gulf war veterans: phase 2 of a two phase cohort study
Ismail, Khalida; Kent, Kate; Brugha, Traolach; Hotopf, Matthew; Hull, Lisa; Seed, Paul; Palmer, Ian; Reid, Steve; Unwin, Catherine; David, Anthony S; Wessely, Simon
2002-01-01
Objectives To examine the prevalence of psychiatric disorders in veterans of the Gulf war with or without unexplained physical disability (a proxy measure of ill health) and in similarly disabled veterans who had not been deployed to the Gulf war (non-Gulf veterans). Design Two phase cohort study. Setting Current and ex-service UK military personnel. Participants Phase 1 consisted of three randomly selected samples of Gulf veterans, veterans of the 1992-7 Bosnia peacekeeping mission, and UK military personnel not deployed to the Gulf war (Era veterans) who had completed a postal health questionnaire. Phase 2 consisted of randomly selected subsamples from phase 1 of Gulf veterans who reported physical disability (n=111) or who did not report disability (n=98) and of Bosnia (n=54) and Era (n=79) veterans who reported physical disability. Main outcome measure Psychiatric disorders assessed by the schedule for clinical assessment in neuropsychiatry and classified by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition. Results Only 24% (n=27) of the disabled Gulf veterans had a formal psychiatric disorder (depression, anxiety, or alcohol related disorder). The prevalence of psychiatric disorders in non-disabled Gulf veterans was 12%. Disability and psychiatric disorders were weakly associated in the Gulf group when confounding was adjusted for (adjusted odds ratio 2.4, 99% confidence interval 0.8 to 7.2, P=0.04). The prevalence of psychiatric disorders was similar in disabled non-Gulf veterans and disabled Gulf veterans ( 19% v 24%; 1.3, 0.5 to 3.4). All groups had rates for post-traumatic stress disorder of between 1% and 3%. Conclusions Most disabled Gulf veterans do not have a formal psychiatric disorder. Post-traumatic stress disorder is not higher in Gulf veterans than in other veterans. Psychiatric disorders do not fully explain self reported ill health in Gulf veterans; alternative explanations for persistent ill health in Gulf veterans are needed. What is already known on this topicGulf veterans report medically unexplained symptoms more often than non-Gulf veteransThe clinical characteristics of ill health in Gulf veterans are not well known, and factors associated with ill health in Gulf veterans are poorly understoodWhat this study addsMost ill Gulf veterans do not have a formal psychiatric disorderThe rates for post-traumatic stress disorder are lowPsychiatric morbidity is not strongly associated with ill health in Gulf veteransThe rates for somatoform disorders are three times greater in disabled Gulf veterans than they are in disabled non-Gulf veterans PMID:12228134
A comparative study of high-mass cluster forming clumps
NASA Astrophysics Data System (ADS)
López-Sepulcre, A.; Cesaroni, R.; Walmsley, C. M.
2010-07-01
Aims: We have searched for star formation activity (mainly infall and outflow signatures) in a sample of high-mass molecular clumps (M > 100 M⊙) in different evolutionary stages and with a wide range of surface densities, with the aim of looking for evolutionary trends and testing observationally recent theoretical models which predict the need for a minimum surface density to form high-mass stars. Methods: Our sample has been selected from single-dish 1.2 mm continuum surveys and is composed of 48 massive molecular clumps, of which 29 are IR-loud and 19 are IR-dark. Each of these has been mapped in the HCO+(1-0), HCN(1-0) and C18O(2-1) transitions with the IRAM-30 m telescope on Pico Veleta (Spain). We derive basic parameters (mass, momentum, kinetic energy) for the clumps and their associated outflows and examine the HCO+(1-0) line profiles for evidence of infall or expansion. Results: Molecular outflows have been detected in 75% of our targets from the presence of high-velocity wings in the HCO+(1-0) spectra. These are equally frequent and massive (between ~1 and ~100 M⊙) in IR-dark and IR-loud clumps, implying similar levels of star formation activity in both kinds of objects. A surface density threshold at Σ = 0.3 g cm-2 has been found above which the outflow detection rate increases significantly and the outflows are on average more massive. The infall detection rate in our sample is low, but significantly higher in the IR-dark sub-sample. Our clump mass estimates using the mm dust emission and C18O(2-1) are sensitive to the temperature, but assuming a value of 15 K for the IR-dark sub-sample, we find evidence that C18O is depleted by a factor ~4.5. The HCO+(1-0) to HCN(1-0) integrated intensity ratios measured reveal a greater dispersion about the mean value in the IR-dark sub-sample than in the IR-loud by a factor of about 5. We find that a considerable number of IR-dark sources are self-absorbed in HCN(1-0) suggesting that radiative transport effects in the ground state transitions have an important influence on the integrated intensity ratio. Conclusions: Our results indicate that, in terms of outflow frequency and energetics, both IR-dark and IR-loud molecular clumps present equivalent signatures of star formation activity, and that the formation of high-mass stars requires sufficiently high clump surface densities. The higher infall detection rate measured for the IR-dark subsample suggests that these objects could be associated with the onset of star formation. Based on observations carried out with the IRAM 30-m telescope at Pico Veleta (Granada, Spain). IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).Appendices A and B are only available in electronic form at http://www.aanda.org
NASA Astrophysics Data System (ADS)
Pedretti, Daniele; Bianchi, Marco
2018-03-01
Breakthrough curves (BTCs) observed during tracer tests in highly heterogeneous aquifers display strong tailing. Power laws are popular models for both the empirical fitting of these curves, and the prediction of transport using upscaling models based on best-fitted estimated parameters (e.g. the power law slope or exponent). The predictive capacity of power law based upscaling models can be however questioned due to the difficulties to link model parameters with the aquifers' physical properties. This work analyzes two aspects that can limit the use of power laws as effective predictive tools: (a) the implication of statistical subsampling, which often renders power laws undistinguishable from other heavily tailed distributions, such as the logarithmic (LOG); (b) the difficulties to reconcile fitting parameters obtained from models with different formulations, such as the presence of a late-time cutoff in the power law model. Two rigorous and systematic stochastic analyses, one based on benchmark distributions and the other on BTCs obtained from transport simulations, are considered. It is found that a power law model without cutoff (PL) results in best-fitted exponents (αPL) falling in the range of typical experimental values reported in the literature (1.5 < αPL < 4). The PL exponent tends to lower values as the tailing becomes heavier. Strong fluctuations occur when the number of samples is limited, due to the effects of subsampling. On the other hand, when the power law model embeds a cutoff (PLCO), the best-fitted exponent (αCO) is insensitive to the degree of tailing and to the effects of subsampling and tends to a constant αCO ≈ 1. In the PLCO model, the cutoff rate (λ) is the parameter that fully reproduces the persistence of the tailing and is shown to be inversely correlated to the LOG scale parameter (i.e. with the skewness of the distribution). The theoretical results are consistent with the fitting analysis of a tracer test performed during the MADE-5 experiment. It is shown that a simple mechanistic upscaling model based on the PLCO formulation is able to predict the ensemble of BTCs from the stochastic transport simulations without the need of any fitted parameters. The model embeds the constant αCO = 1 and relies on a stratified description of the transport mechanisms to estimate λ. The PL fails to reproduce the ensemble of BTCs at late time, while the LOG model provides consistent results as the PLCO model, however without a clear mechanistic link between physical properties and model parameters. It is concluded that, while all parametric models may work equally well (or equally wrong) for the empirical fitting of the experimental BTCs tails due to the effects of subsampling, for predictive purposes this is not true. A careful selection of the proper heavily tailed models and corresponding parameters is required to ensure physically-based transport predictions.
Sun exposure in pigs increases the vitamin D nutritional quality of pork
Wechsler, Perry J.; Hollis, Bruce W.; Makowski, Andrew J.
2017-01-01
There is a high prevalence of vitamin D insufficiency and deficiency worldwide likely because of both limited sun-exposure and inadequate dietary intake. Meat, including pork, is not typically considered a dietary source of vitamin D, possibly because of management practices that raise pigs in confinement. This experiment determined the vitamin D content of loin and subcutaneous adipose tissue in sun-exposed finisher pigs. Two separate groups of pigs were used. The first group (28 white Landrace-Duroc) was assigned at random to either sunlight exposure (SUN) in spring and summer or confinement per standard practice (Control). The second (24 Yorkshire-Duroc-Landrace) underwent the same exposure protocol but was exposed in summer and fall or assigned to control (Control). A subsample of five SUN and four Control pigs, matched for weight and body condition score, was selected for slaughter from each group. Pigs (n = 10 SUN, n = 8 Control) had blood drawn for analysis of 25(OH)D3 concentration before/after sun exposure or control, and tissue samples were taken at slaughter for analysis of tissue vitamin D3 and 25(OH)D3 concentration. Three random samples from a single loin chop and surrounding adipose were collected and analyzed. Serum concentrations of 25(OH)D3 did not differ (P≥0.376) between treatments prior to sun exposure in either group, but was increased (time*treatment interaction, P<0.001) with SUN exposure. Total vitamin D content (D3 plus 25(OH)D3) of loin tissue was increased (P < 0.001) with sun exposure and averaged 0.997±0.094 μg/100g and 0.348±0.027 μg/100g for sun and control pigs, respectively. While exposure to sunlight increased (P = 0.003) tissue content of 25(OH) D in subcutaneous adipose tissue, vitamin D3 content was similar between treatments (P = 0.56). Sunlight exposure in pigs increased the vitamin D content of loin, and may provide an additional source of dietary vitamin D. PMID:29136033
Sun exposure in pigs increases the vitamin D nutritional quality of pork.
Larson-Meyer, D Enette; Ingold, Bennett C; Fensterseifer, Samanta R; Austin, Kathleen J; Wechsler, Perry J; Hollis, Bruce W; Makowski, Andrew J; Alexander, Brenda M
2017-01-01
There is a high prevalence of vitamin D insufficiency and deficiency worldwide likely because of both limited sun-exposure and inadequate dietary intake. Meat, including pork, is not typically considered a dietary source of vitamin D, possibly because of management practices that raise pigs in confinement. This experiment determined the vitamin D content of loin and subcutaneous adipose tissue in sun-exposed finisher pigs. Two separate groups of pigs were used. The first group (28 white Landrace-Duroc) was assigned at random to either sunlight exposure (SUN) in spring and summer or confinement per standard practice (Control). The second (24 Yorkshire-Duroc-Landrace) underwent the same exposure protocol but was exposed in summer and fall or assigned to control (Control). A subsample of five SUN and four Control pigs, matched for weight and body condition score, was selected for slaughter from each group. Pigs (n = 10 SUN, n = 8 Control) had blood drawn for analysis of 25(OH)D3 concentration before/after sun exposure or control, and tissue samples were taken at slaughter for analysis of tissue vitamin D3 and 25(OH)D3 concentration. Three random samples from a single loin chop and surrounding adipose were collected and analyzed. Serum concentrations of 25(OH)D3 did not differ (P≥0.376) between treatments prior to sun exposure in either group, but was increased (time*treatment interaction, P<0.001) with SUN exposure. Total vitamin D content (D3 plus 25(OH)D3) of loin tissue was increased (P < 0.001) with sun exposure and averaged 0.997±0.094 μg/100g and 0.348±0.027 μg/100g for sun and control pigs, respectively. While exposure to sunlight increased (P = 0.003) tissue content of 25(OH) D in subcutaneous adipose tissue, vitamin D3 content was similar between treatments (P = 0.56). Sunlight exposure in pigs increased the vitamin D content of loin, and may provide an additional source of dietary vitamin D.
On Galactic Density Modeling in the Presence of Dust Extinction
NASA Astrophysics Data System (ADS)
Bovy, Jo; Rix, Hans-Walter; Green, Gregory M.; Schlafly, Edward F.; Finkbeiner, Douglas P.
2016-02-01
Inferences about the spatial density or phase-space structure of stellar populations in the Milky Way require a precise determination of the effective survey volume. The volume observed by surveys such as Gaia or near-infrared spectroscopic surveys, which have good coverage of the Galactic midplane region, is highly complex because of the abundant small-scale structure in the three-dimensional interstellar dust extinction. We introduce a novel framework for analyzing the importance of small-scale structure in the extinction. This formalism demonstrates that the spatially complex effect of extinction on the selection function of a pencil-beam or contiguous sky survey is equivalent to a low-pass filtering of the extinction-affected selection function with the smooth density field. We find that the angular resolution of current 3D extinction maps is sufficient for analyzing Gaia sub-samples of millions of stars. However, the current distance resolution is inadequate and needs to be improved by an order of magnitude, especially in the inner Galaxy. We also present a practical and efficient method for properly taking the effect of extinction into account in analyses of Galactic structure through an effective selection function. We illustrate its use with the selection function of red-clump stars in APOGEE using and comparing a variety of current 3D extinction maps.
Malinowsky, Camilla; Nygård, Louise; Kottorp, Anders
2014-01-01
E-health services are increasingly offered to provide clients with information and a link to healthcare services. The aim of this study is to investigate the perceived access to and the potential to use technologies important for e-health services among older adults with mild cognitive impairment (MCI) or mild Alzheimer's disease (AD) and controls. The perceived access to and perception of difficulty in the use of everyday technology (such as cell phones, coffee machines, computers) was investigated in a sample of older adults (n = 118) comprising three subsamples: adults with MCI (n = 37), with mild AD (n = 37), and controls (n = 44) using the Everyday Technology Use Questionnaire (ETUQ). The use of seven technologies important for e-health services was specifically examined for each subsample and compared between the subsamples. The findings demonstrated that the older adults in all subsamples perceive access to e-health technologies and potentially would use them competently in several e-health services. However, among persons with AD a lower proportion of perceived access to the technology was described, as well as for persons with MCI. To make the benefits of e-health services available and used by all clients, it is important to consider access to the technology required in e-health services and also to support the clients' capabilities to understand and use the technologies. Also, the potential use of the ETUQ to explore the perceived access to and competence in using e-health technologies is a vital issue in the use of e-health services.
Sediment Core Extrusion Method at Millimeter Resolution Using a Calibrated, Threaded-rod.
Schwing, Patrick T; Romero, Isabel C; Larson, Rebekka A; O'Malley, Bryan J; Fridrik, Erika E; Goddard, Ethan A; Brooks, Gregg R; Hastings, David W; Rosenheim, Brad E; Hollander, David J; Grant, Guy; Mulhollan, Jim
2016-08-17
Aquatic sediment core subsampling is commonly performed at cm or half-cm resolution. Depending on the sedimentation rate and depositional environment, this resolution provides records at the annual to decadal scale, at best. An extrusion method, using a calibrated, threaded-rod is presented here, which allows for millimeter-scale subsampling of aquatic sediment cores of varying diameters. Millimeter scale subsampling allows for sub-annual to monthly analysis of the sedimentary record, an order of magnitude higher than typical sampling schemes. The extruder consists of a 2 m aluminum frame and base, two core tube clamps, a threaded-rod, and a 1 m piston. The sediment core is placed above the piston and clamped to the frame. An acrylic sampling collar is affixed to the upper 5 cm of the core tube and provides a platform from which to extract sub-samples. The piston is rotated around the threaded-rod at calibrated intervals and gently pushes the sediment out the top of the core tube. The sediment is then isolated into the sampling collar and placed into an appropriate sampling vessel (e.g., jar or bag). This method also preserves the unconsolidated samples (i.e., high pore water content) at the surface, providing a consistent sampling volume. This mm scale extrusion method was applied to cores collected in the northern Gulf of Mexico following the Deepwater Horizon submarine oil release. Evidence suggests that it is necessary to sample at the mm scale to fully characterize events that occur on the monthly time-scale for continental slope sediments.
Funes, Cynthia M; Rodriguez, Juventino Hernandez; Lopez, Steven Regeser
2016-12-01
This study provides a systematic comparison of the norms of 3 Spanish-language Wechsler Adult Intelligence Scales (WAIS-III) batteries from Mexico, Spain, and Puerto Rico, and the U.S. English-language WAIS-III battery. Specifically, we examined the performance of the 4 normative samples on 2 identical subtests (Digit Span and Digit Symbol-Coding) and 1 nearly identical subtest (Block Design). We found that across most age groups the means associated with the Spanish-language versions of the 3 subtests were lower than the means of the U.S. English-language version. In addition, we found that for most age ranges the Mexican subsamples scored lower than the Spanish subsamples. Lower educational levels of Mexicans and Spaniards compared to U.S. residents are consistent with the general pattern of findings. These results suggest that because of the different norms, applying any of the 3 Spanish-language versions of the WAIS-III generally risks underestimating deficits, and that applying the English-language WAIS-III norms risks overestimating deficits of Spanish-speaking adults. There were a few exceptions to these general patterns. For example, the Mexican subsample ages 70 years and above performed significantly better on the Digit Symbol and Block Design than did the U.S. and Spanish subsamples. Implications for the clinical assessment of U.S. Spanish-speaking Latinos and test adaptation are discussed with an eye toward improving the clinical care for this community. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Sediment Core Extrusion Method at Millimeter Resolution Using a Calibrated, Threaded-rod
Schwing, Patrick T.; Romero, Isabel C.; Larson, Rebekka A.; O'Malley, Bryan J.; Fridrik, Erika E.; Goddard, Ethan A.; Brooks, Gregg R.; Hastings, David W.; Rosenheim, Brad E.; Hollander, David J.; Grant, Guy; Mulhollan, Jim
2016-01-01
Aquatic sediment core subsampling is commonly performed at cm or half-cm resolution. Depending on the sedimentation rate and depositional environment, this resolution provides records at the annual to decadal scale, at best. An extrusion method, using a calibrated, threaded-rod is presented here, which allows for millimeter-scale subsampling of aquatic sediment cores of varying diameters. Millimeter scale subsampling allows for sub-annual to monthly analysis of the sedimentary record, an order of magnitude higher than typical sampling schemes. The extruder consists of a 2 m aluminum frame and base, two core tube clamps, a threaded-rod, and a 1 m piston. The sediment core is placed above the piston and clamped to the frame. An acrylic sampling collar is affixed to the upper 5 cm of the core tube and provides a platform from which to extract sub-samples. The piston is rotated around the threaded-rod at calibrated intervals and gently pushes the sediment out the top of the core tube. The sediment is then isolated into the sampling collar and placed into an appropriate sampling vessel (e.g., jar or bag). This method also preserves the unconsolidated samples (i.e., high pore water content) at the surface, providing a consistent sampling volume. This mm scale extrusion method was applied to cores collected in the northern Gulf of Mexico following the Deepwater Horizon submarine oil release. Evidence suggests that it is necessary to sample at the mm scale to fully characterize events that occur on the monthly time-scale for continental slope sediments. PMID:27585268
47 CFR 1.1604 - Post-selection hearings.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 47 Telecommunication 1 2010-10-01 2010-10-01 false Post-selection hearings. 1.1604 Section 1.1604 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1604 Post-selection hearings. (a) Following the random...
47 CFR 1.1604 - Post-selection hearings.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 1 2011-10-01 2011-10-01 false Post-selection hearings. 1.1604 Section 1.1604 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1604 Post-selection hearings. (a) Following the random...
Comartin, Erin B; Burgess-Proctor, Amanda; Kubiak, Sheryl; Bender, Kimberly A; Kernsmith, Poco
2018-05-01
This study identifies the characteristics that distinguish between women's and men's sexual offending. We compare women and men currently incarcerated for a sex offense in one state using two data sources: administrative data on sex offenders in the state prison ( N = 9,235) and subsample surveys ( n = 129). Bivariate and logistic regressions were used in these analyses. Women account for a small proportion (1.1%, N = 98) of incarcerated sex offenders. In the population, women and men were convicted of similar types of sex offenses. The subsample was demographically similar to the population. In the subsample, women were more likely than men to have a child victim, be the parent/guardian of the victim, have a co-offender, and repeatedly perpetrate against the same victim. Findings suggest that women convicted and sentenced for a sex offense differ from their male counterparts, with predictive factors being dependent upon the age of their victim(s). Sex offender treatment interventions developed for men are poorly suited to and may have limited efficacy for women.
NASA Astrophysics Data System (ADS)
Deng, Xin-Fa; Song, Jun; Chen, Yi-Qing; Jiang, Peng; Ding, Ying-Ping
2014-08-01
Using two volume-limited Main galaxy samples of the Sloan Digital Sky Survey Data Release 10 (SDSS DR10), we investigate the dependence of the clustering properties of galaxies on stellar velocity dispersion by cluster analysis. It is found that in the luminous volume-limited Main galaxy sample, except at r=1.2, richer and larger systems can be more easily formed in the large stellar velocity dispersion subsample, while in the faint volume-limited Main galaxy sample, at r≥0.9, an opposite trend is observed. According to statistical analyses of the multiplicity functions, we conclude in two volume-limited Main galaxy samples: small stellar velocity dispersion galaxies preferentially form isolated galaxies, close pairs and small group, while large stellar velocity dispersion galaxies preferentially inhabit the dense groups and clusters. However, we note the difference between two volume-limited Main galaxy samples: in the faint volume-limited Main galaxy sample, at r≥0.9, the small stellar velocity dispersion subsample has a higher proportion of galaxies in superclusters ( n≥200) than the large stellar velocity dispersion subsample.
Pavlović, Miroslav; Zunić-Pavlović, Vesna; Glumbić, Nenad
2013-11-01
This study investigated aggressive behaviour in Serbian adolescents with intellectual disability (ID) compared to typically developing peers. The sample consisted of both male and female adolescents aged 12-18 years. One hundred of the adolescents had ID, and 348 adolescents did not have ID. The adolescents were asked to complete the Reactive-Proactive Aggression Questionnaire (RPQ), and their teachers provided ratings of aggression for the adolescents using the Children's Scale of Hostility and Aggression: Reactive-Proactive (C-SHARP). Results indicated that adolescents reported a higher prevalence of aggressive behaviour than their teachers. Reactive aggression was more prevalent than proactive aggression in both subsamples. In the subsample of adolescents with ID, there were no sex or age differences for aggression. However, in the normative subsample, boys and older adolescents scored significantly higher on aggression. According to adolescent self-reports the prevalence of aggression was higher in adolescents without ID, while teachers perceived aggressive behaviour to be more prevalent in adolescents with ID. Scientific and practical implications are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.
Sub-sampling genetic data to estimate black bear population size: A case study
Tredick, C.A.; Vaughan, M.R.; Stauffer, D.F.; Simek, S.L.; Eason, T.
2007-01-01
Costs for genetic analysis of hair samples collected for individual identification of bears average approximately US$50 [2004] per sample. This can easily exceed budgetary allowances for large-scale studies or studies of high-density bear populations. We used 2 genetic datasets from 2 areas in the southeastern United States to explore how reducing costs of analysis by sub-sampling affected precision and accuracy of resulting population estimates. We used several sub-sampling scenarios to create subsets of the full datasets and compared summary statistics, population estimates, and precision of estimates generated from these subsets to estimates generated from the complete datasets. Our results suggested that bias and precision of estimates improved as the proportion of total samples used increased, and heterogeneity models (e.g., Mh[CHAO]) were more robust to reduced sample sizes than other models (e.g., behavior models). We recommend that only high-quality samples (>5 hair follicles) be used when budgets are constrained, and efforts should be made to maximize capture and recapture rates in the field.
Alotaibi, Khaled N
2016-06-01
This study examined the psychometric properties of the Arabic version of Abbott's Creative Self-Efficacy inventory. Saudi honors students (157 men vs. 163 women) participated. These students are undergraduates (M age = 19.5 year, SD = 1.9) who complete 30 credit hours with a grade point average of no less than 4.5 out of 5. The results showed that the internal consistency (α = .87) and the test-retest reliabilities (r = .73) were satisfactory. The study sample was separated into two subsamples. The data from the first subsample (n = 60) were used to conduct an exploratory factor analysis, whereas the data from the second subsample (n = 260) were used to perform a confirmatory factor analysis. The results of exploratory factor analysis and confirmatory factor analysis indicated that creative self-efficacy was not a unidimensional construct but consisted of two factors labeled "creative thinking self-efficacy" and "creative performance self-efficacy." As expected, this two-factor model fit the data adequately, supporting prior research that treated creative self-efficacy as multidimensional construct. © The Author(s) 2016.
Swami, Viren; García, Antonio Alías; Barron, David
2017-09-01
We examined the psychometric properties of a Spanish translation of the Body Appreciation Scale-2 (BAS-2) in a community sample of 411 women and 389 men in Almería, Spain. Participants completed the 10-item BAS-2 along with measures of appearance evaluation, body areas satisfaction, self-esteem, life satisfaction, and self-reported body mass index (BMI). Exploratory factor analyses with one split-half subsample revealed that BAS-2 scores had a one-dimensional factor structure in women and men. Confirmatory factor analysis with a second split-half subsample showed the one-dimensional factor structure had acceptable fit and was invariant across sex. There were no significant sex differences in BAS-2 scores. BAS-2 scores were significantly and positively correlated with appearance evaluation, body areas satisfaction, self-esteem, and life satisfaction. Body appreciation was significantly and negatively correlated with BMI in men, but associations in women were only significant in the second subsample. Results suggest that the Spanish BAS-2 has adequate psychometric properties. Copyright © 2017 Elsevier Ltd. All rights reserved.
Hansen, Hans; Weber, Reinhard
2009-02-01
An evaluation of tonal components in noise using a semantic differential approach yields several perceptual and connotative factors. This study investigates the effect of culture on these factors with the aid of equivalent listening tests carried out in Japan (n=20), France (n=23), and Germany (n=20). The data's equivalence level is determined by a bias analysis. This analysis gives insight in the cross-cultural validity of the scales used for sound character determination. Three factors were extracted by factor analysis in all cultural subsamples: pleasant, metallic, and power. By employing appropriate target rotations of the factor spaces, the rotated factors were compared and they yield high similarities between the different cultural subsamples. To check cross-cultural differences in means, an item bias analysis was conducted. The a priori assumption of unbiased scales is rejected; the differences obtained are partially linked to bias effects. Acoustical sound descriptors were additionally tested for the semantic dimensions. The high agreement in judgments between the different cultural subsamples contrast the moderate success of the signal parameters to describe the dimensions.
Binding and strategic selection in working memory: a lifespan dissociation.
Sander, Myriam C; Werkle-Bergner, Markus; Lindenberger, Ulman
2011-09-01
Working memory (WM) shows a gradual increase during childhood, followed by accelerating decline from adulthood to old age. To examine these lifespan differences more closely, we asked 34 children (10-12 years), 40 younger adults (20-25 years), and 39 older adults (70-75 years) to perform a color change detection task. Load levels and encoding durations were varied for displays including targets only (Experiment 1) or targets plus distracters (Experiment 2, investigating a subsample of Experiment 1). WM performance was lower in older adults and children than in younger adults. Longer presentation times were associated with better performance in all age groups, presumably reflecting increasing effects of strategic selection mechanisms on WM performance. Children outperformed older adults when encoding times were short, and distracter effects were larger in children and older adults than in younger adults. We conclude that strategic selection in WM develops more slowly during childhood than basic binding operations, presumably reflecting the delay in maturation of frontal versus medio-temporal brain networks. In old age, both sets of mechanisms decline, reflecting senescent change in both networks. We discuss similarities to episodic memory development and address open questions for future research.
Khan, Jahidur Rahman; Islam, Md Mazharul; Awan, Nabil; Muurlink, Olav
2018-03-06
Low birth weight (LBW) remains a leading global cause of childhood morbidity and mortality. This study leverages a large national survey to determine current prevalence and socioeconomic, demographic and heath related factors associated with LBW in Bangladesh. Data from the Multiple Indicator Cluster Survey (MICS) 2012-13 of Bangladesh were analyzed. A total of 2319 women for whom contemporaneous birth weight data was available and who had a live birth in the two years preceding the survey were sampled for this study. However, this analysis only was able to take advantage of 29% of the total sample with 71% missing birth weight for newborns. The indicator, LBW (< 2500 g) of infants, was examined as the outcome variable in association with different socioeconomic, demographic and health-related covariates. Mixed-effects logistic regression was performed to identify possible factors related to LBW. In the selected sub-sample, about 20% of infants were born with LBW, with lowest rates observed in Rajshahi (11%) and highest rates in Rangpur (28%). Education of mothers (adjusted odds ratio [AOR] 0.52, 95% confidence interval [CI] 0.39-0.68 for secondary or higher educated mother) and poor antenatal care (ANC) (AOR 1.40, 95% CI 1.04-1.90) were associated with LBW after adjusting for mother's age, parity and cluster effects. Mothers from wealthier families were less likely to give birth to an LBW infant. Further indicators that wealth continues to play a role in LBW were that place of delivery, ANC and delivery assistance by quality health workers were significantly associated with LBW. However there has been a notable fall in LBW prevalence in Bangladesh since the last comparable survey (prevalence 36%), and an evidence of possible elimination of rural/urban disparities. Low birth weight remains associated with key indicators not just of maternal poverty (notably adequate maternal education) but also markers of structural poverty in health care (notably quality ANC). Results based on this sub-sample indicate LBW is still a public health concern in Bangladesh and an integrated effort from all stakeholders should be continued and interventions based on the study findings should be devised to further reduce the risk of LBW.
The revised Generalized Expectancy for Success Scale: a validity and reliability study.
Hale, W D; Fiedler, L R; Cochran, C D
1992-07-01
The Generalized Expectancy for Success Scale (GESS; Fibel & Hale, 1978) was revised and assessed for reliability and validity. The revised version was administered to 199 college students along with other conceptually related measures, including the Rosenberg Self-Esteem Scale, the Life Orientation Test, and Rotter's Internal-External Locus of Control Scale. One subsample of students also completed the Eysenck Personality Inventory, while another subsample performed a criterion-related task that involved risk taking. Item analysis yielded 25 items with correlations of .45 or higher with the total score. Results indicated high internal consistency and test-retest reliability.
[Demonstration plan used in the study of human reproduction in the district of Sao Paulo. 1967].
Silva, Eunice Pinho de Castro
2006-10-01
This work presents the sampling procedure used to select the sample got for a "Human Reproduction Study in the District of São Paulo" (Brazil), done by the Department of Applied Statistics of "Faculdade de Higiene e Saúde Pública da Universidade de São Paulo". The procedure tried to solve the situation which resulted from the limitation in cost, time and lack of a frame that could be used in order to get a probability sample in the fixed term of time and with the fixed cost. It consisted in a two stage sampling with dwelling-units as primary units and women as secondary units. At the first stage, it was used stratified sampling in which sub-districts were taken as strata. In order to select primary units, there was a selection of points ("starting points") on the maps of subdistricts by a procedure that was similar to that one called "square grid" but differed from this in several aspects. There were fixed rules to establish a correspondence between each selected "starting point" and a set of three dwelling units where at least one woman of the target population lived. In the selected dwelling units where more than one woman of target population lived, there was a sub-sampling in order to select one of them. In this selection each woman living in the dwelling unit had equal probability of selection. Several "no-answer" cases and correspondent instructions to be followed by the interviewers are presented too.
The Swift/UVOT catalogue of NGC 4321 star-forming sources: a case against density wave theory
NASA Astrophysics Data System (ADS)
Ferreras, Ignacio; Cropper, Mark; Kawata, Daisuke; Page, Mat; Hoversten, Erik A.
2012-08-01
We study the star-forming regions in the spiral galaxy NGC 4321 (M100). We take advantage of the spatial resolution (2.5 arcsec full width at half-maximum) of the Swift/Ultraviolet/Optical Telescope camera and the availability of three ultraviolet (UV) passbands in the region 1600 < λ < 3000 Å, in combination with optical and infrared (IR) imaging from Sloan Digital Sky Survey, KPNO/Hα and Spitzer/IRAC, to obtain a catalogue of 787 star-forming regions out to three disc scalelengths. We use a large volume of star formation histories, combined with stellar population synthesis, to determine the properties of the young stellar component and its relationship with the spiral arms. The Hα luminosities of the sources have a strong decreasing radial trend, suggesting more massive star-forming regions in the central part of the galaxy. When segregated with respect to near-UV (NUV)-optical colour, blue sources have a significant excess of flux in the IR at 8 μm, revealing the contribution from polycyclic aromatic hydrocarbons, although the overall reddening of these sources stays below E(B - V) = 0.2 mag. The distribution of distances to the spiral arms is compared for subsamples selected according to Hα luminosity, NUV-optical colour or ages derived from a population synthesis model. An offset would be expected between these subsamples as a function of radius if the pattern speed of the spiral arm were constant - as predicted by classic density wave theory. No significant offsets are found, favouring instead a mechanism where the pattern speed has a radial dependence.
Sulaiman, Irshad M; Jacobs, Emily; Simpson, Steven; Kerdahi, Khalil
2017-06-01
The primary mission of the U.S. Food and Drug Administration is to enforce the Food, Drug, and Cosmetic Act and regulate food, drug, and cosmetic products. Thus, this agency monitors the presence of pathogenic microorganisms in these products, including canned foods, as one of the regulatory action criteria and also ensures that these products are safe for human consumption. This study was carried out to investigate the effectiveness of pathogen control and integrity of ready-to-eat canned food containing Black Bean Corn Poblano Salsa. A total of nine unopened and recalled canned glass jars from the same lot were examined initially by conventional microbiologic protocols that involved a two-step enrichment, followed by streaking on selective agar plates, for the presence of gram-positive and gram-negative bacteria. Of the eight subsamples examined for each sample, all subsamples of one of the containers were found positive for the presence of slow-growing rod-shaped, gram-positive, facultative anaerobic bacteria. The recovered isolates were subsequently sequenced at rRNA and gyrB loci. Afterward, multilocus sequence typing (MLST) was performed characterizing 11 additional known MLST loci (clpX, dnaA, dnaK, groEL, murC, murE, pepX, pyrG, recA, rpoB, and uvrC). Analyses of the nucleotide sequences of rRNA, gyrB, and 11 MLST loci confirmed these gram-positive bacteria recovered from canned food to be Lactobacillus fermentum . Thus, the DNA sequencing of housekeeping MLST genes can provide species identification of L. fermentum and can be used in the canned food monitoring program of public health importance.
Data-driven sampling method for building 3D anatomical models from serial histology
NASA Astrophysics Data System (ADS)
Salunke, Snehal Ulhas; Ablove, Tova; Danforth, Theresa; Tomaszewski, John; Doyle, Scott
2017-03-01
In this work, we investigate the effect of slice sampling on 3D models of tissue architecture using serial histopathology. We present a method for using a single fully-sectioned tissue block as pilot data, whereby we build a fully-realized 3D model and then determine the optimal set of slices needed to reconstruct the salient features of the model objects under biological investigation. In our work, we are interested in the 3D reconstruction of microvessel architecture in the trigone region between the vagina and the bladder. This region serves as a potential avenue for drug delivery to treat bladder infection. We collect and co-register 23 serial sections of CD31-stained tissue images (6 μm thick sections), from which four microvessels are selected for analysis. To build each model, we perform semi-automatic segmentation of the microvessels. Subsampled meshes are then created by removing slices from the stack, interpolating the missing data, and re-constructing the mesh. We calculate the Hausdorff distance between the full and subsampled meshes to determine the optimal sampling rate for the modeled structures. In our application, we found that a sampling rate of 50% (corresponding to just 12 slices) was sufficient to recreate the structure of the microvessels without significant deviation from the fullyrendered mesh. This pipeline effectively minimizes the number of histopathology slides required for 3D model reconstruction, and can be utilized to either (1) reduce the overall costs of a project, or (2) enable additional analysis on the intermediate slides.
Jarup, Lars; Dudley, Marie-Louise; Babisch, Wolfgang; Houthuijs, Danny; Swart, Wim; Pershagen, Göran; Bluhm, Gösta; Katsouyanni, Klea; Velonakis, Manolis; Cadum, Ennio; Vigna-Taglianti, Federica
2005-11-01
An increasing number of people live near airports with considerable noise and air pollution. The Hypertension and Exposure to Noise near Airports (HYENA) project aims to assess the impact of airport-related noise exposure on blood pressure (BP) and cardiovascular disease using a cross-sectional study design. We selected 6,000 persons (45-70 years of age) who had lived at least 5 years near one of six major European airports. We used modeled aircraft noise contours, aiming to maximize exposure contrast. Automated BP instruments are used to reduce observer error. We designed a standardized questionnaire to collect data on annoyance, noise disturbance, and major confounders. Cortisol in saliva was collected in a subsample of the study population (n = 500) stratified by noise exposure level. To investigate short-term noise effects on BP and possible effects on nighttime BP dipping, we measured 24-hr BP and assessed continuous night noise in another subsample (n = 200). To ensure comparability between countries, we used common noise models to assess individual noise exposure, with a resolution of 1 dB(A). Modifiers of individual exposure, such as the orientation of living and bedroom toward roads, window-opening habits, and sound insulation, were assessed by the questionnaire. For four airports, we estimated exposure to air pollution to explore modifying effects of air pollution on cardiovascular disease. The project assesses exposure to traffic-related air pollutants, primarily using data from another project funded by the European Union (APMoSPHERE, Air Pollution Modelling for Support to Policy on Health and Environmental Risks in Europe).
Columbia-Suicide Severity Rating Scale
Gipson, Polly Y.; Agarwala, Prachi; Opperman, Kiel J.; Horwitz, Adam; King, Cheryl A.
2016-01-01
Objective Despite the high prevalence of psychiatric emergency (PE) visits for attempted suicide and nonsuicidal self-injury (NSSI) among adolescents, we have limited information about assessment tools that are helpful in predicting subsequent risk for suicide attempts among adolescents in PE settings. This study examined the predictive validity of a highly promising instrument, the Columbia-Suicide Severity Rating Scale (C-SSRS). Method Participants were 178 adolescents (44.4% male; ages 13–17 years) seeking PE services. The C-SSRS interview and selected medical chart data were collected for the index visit and subsequent visits during a 1-year follow-up. Results A suicide risk concern was the most common chief complaint (50.6%) in this sample, and nearly one third of the adolescents (30.4%) reported a lifetime history of suicide attempt at index visit. Sixty-two adolescents (34.8%) had at least one return PE visit during follow-up. Lifetime history of NSSI predicted both return PE visits and a suicide attempt at return visit. The C-SSRS intensity scale score was a significant predictor of a suicide attempt at return visit for both the full sample of adolescents and the subsample who reported suicidal ideation at their index visit. In this subsample, one specific item on the intensity scale, duration, was also a significant predictor of both a return PE visit and a suicide attempt at return visit. Conclusions The C-SSRS intensity scale and NSSI had predictive validity for suicide attempts at return visit. Results also suggest that duration of adolescents’ suicidal thoughts may be particularly important to risk for suicidal behavior, warranting further study. PMID:25285389
Mapping the Growing Discipline of Dissemination and Implementation Science in Health
Norton, Wynne E.; Lungeanu, Alina; Chambers, David A.; Contractor, Noshir
2017-01-01
Background The field of dissemination and implementation (D&I) research in health has grown considerably in the past decade. Despite the potential for advancing the science, limited research has focused on mapping the field. Methods We administered an online survey to individuals in the D&I field to assess participants’ demographics and expertise, as well as engagement with journals and conferences, publications, and grants. A combined roster–nomination method was used to collect data on participants’ advice networks and collaboration networks; participants’ motivations for choosing collaborators was also assessed. Frequency and descriptive statistics were used to characterize the overall sample; network metrics were used to characterize both networks. Among a sub-sample of respondents who were researchers, regression analyses identified predictors of two metrics of academic performance (i.e., publications and funded grants). Results A total of 421 individuals completed the survey, representing a 30.75% response rate of eligible individuals. Most participants were White (n = 343), female (n = 284, 67.4%), and identified as a researcher (n = 340, 81%). Both the advice and the collaboration networks displayed characteristics of a small world network. The most important motivations for selecting collaborators were aligned with advancing the science (i.e., prior collaborators, strong reputation, and good collaborators) rather than relying on human proclivities for homophily, proximity, and friendship. Among a sub-sample of 295 researchers, expertise (individual predictor), status (advice network), and connectedness (collaboration network) were significant predictors of both metrics of academic performance. Conclusions Network-based interventions can enhance collaboration and productivity; future research is needed to leverage these data to advance the field. PMID:29249842
Mapping the Growing Discipline of Dissemination and Implementation Science in Health.
Norton, Wynne E; Lungeanu, Alina; Chambers, David A; Contractor, Noshir
2017-09-01
The field of dissemination and implementation (D&I) research in health has grown considerably in the past decade. Despite the potential for advancing the science, limited research has focused on mapping the field. We administered an online survey to individuals in the D&I field to assess participants' demographics and expertise, as well as engagement with journals and conferences, publications, and grants. A combined roster-nomination method was used to collect data on participants' advice networks and collaboration networks; participants' motivations for choosing collaborators was also assessed. Frequency and descriptive statistics were used to characterize the overall sample; network metrics were used to characterize both networks. Among a sub-sample of respondents who were researchers, regression analyses identified predictors of two metrics of academic performance (i.e., publications and funded grants). A total of 421 individuals completed the survey, representing a 30.75% response rate of eligible individuals. Most participants were White (n = 343), female (n = 284, 67.4%), and identified as a researcher (n = 340, 81%). Both the advice and the collaboration networks displayed characteristics of a small world network. The most important motivations for selecting collaborators were aligned with advancing the science (i.e., prior collaborators, strong reputation, and good collaborators) rather than relying on human proclivities for homophily, proximity, and friendship. Among a sub-sample of 295 researchers, expertise (individual predictor), status (advice network), and connectedness (collaboration network) were significant predictors of both metrics of academic performance. Network-based interventions can enhance collaboration and productivity; future research is needed to leverage these data to advance the field.
NASA Astrophysics Data System (ADS)
Tang, Jian; Qiao, Junfei; Wu, ZhiWei; Chai, Tianyou; Zhang, Jian; Yu, Wen
2018-01-01
Frequency spectral data of mechanical vibration and acoustic signals relate to difficult-to-measure production quality and quantity parameters of complex industrial processes. A selective ensemble (SEN) algorithm can be used to build a soft sensor model of these process parameters by fusing valued information selectively from different perspectives. However, a combination of several optimized ensemble sub-models with SEN cannot guarantee the best prediction model. In this study, we use several techniques to construct mechanical vibration and acoustic frequency spectra of a data-driven industrial process parameter model based on selective fusion multi-condition samples and multi-source features. Multi-layer SEN (MLSEN) strategy is used to simulate the domain expert cognitive process. Genetic algorithm and kernel partial least squares are used to construct the inside-layer SEN sub-model based on each mechanical vibration and acoustic frequency spectral feature subset. Branch-and-bound and adaptive weighted fusion algorithms are integrated to select and combine outputs of the inside-layer SEN sub-models. Then, the outside-layer SEN is constructed. Thus, "sub-sampling training examples"-based and "manipulating input features"-based ensemble construction methods are integrated, thereby realizing the selective information fusion process based on multi-condition history samples and multi-source input features. This novel approach is applied to a laboratory-scale ball mill grinding process. A comparison with other methods indicates that the proposed MLSEN approach effectively models mechanical vibration and acoustic signals.
Predictors of Poor School Readiness in Children Without Developmental Delay at Age 2
Dudovitz, Rebecca N.; Coker, Tumaini R.; Barnert, Elizabeth S.; Biely, Christopher; Li, Ning; Szilagyi, Peter G.; Larson, Kandyce; Halfon, Neal; Zimmerman, Frederick J.; Chung, Paul J.
2016-01-01
BACKGROUND AND OBJECTIVES: Current recommendations emphasize developmental screening and surveillance to identify developmental delays (DDs) for referral to early intervention (EI) services. Many young children without DDs, however, are at high risk for poor developmental and behavioral outcomes by school entry but are ineligible for EI. We developed models for 2-year-olds without DD that predict, at kindergarten entry, poor academic performance and high problem behaviors. METHODS: Data from the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B), were used for this study. The analytic sample excluded children likely eligible for EI because of DDs or very low birth weight. Dependent variables included low academic scores and high problem behaviors at the kindergarten wave. Regression models were developed by using candidate predictors feasibly obtainable during typical 2-year well-child visits. Models were cross-validated internally on randomly selected subsamples. RESULTS: Approximately 24% of all 2-year-old children were ineligible for EI at 2 years of age but still had poor academic or behavioral outcomes at school entry. Prediction models each contain 9 variables, almost entirely parental, social, or economic. Four variables were associated with both academic and behavioral risk: parental education below bachelor’s degree, little/no shared reading at home, food insecurity, and fair/poor parental health. Areas under the receiver-operating characteristic curve were 0.76 for academic risk and 0.71 for behavioral risk. Adding the mental scale score from the Bayley Short Form–Research Edition did not improve areas under the receiver-operating characteristic curve for either model. CONCLUSIONS: Among children ineligible for EI services, a small set of clinically available variables at age 2 years predicted academic and behavioral outcomes at school entry. PMID:27432845
Ejtahed, Hanieh-Sadat; Qorbani, Mostafa; Motlagh, Mohammad Esmaeil; Angoorani, Pooneh; Hasani-Ranjbar, Shirin; Ziaodini, Hasan; Taheri, Majzoubeh; Ahadi, Zeinab; Beshtar, Shaghayegh; Aminaee, Tahereh; Heshmat, Ramin; Kelishadi, Roya
2017-11-01
This study aims to examine the association of anthropometric indices with continuous metabolic syndrome (cMetS) among Iranian children and adolescents. This multicentric study was conducted on 14138 students aged 7-18 years, who participated in a national surveillance program. Fasting blood sample was obtained from a subsample of 3843 randomly selected students. Physical examination including the measurement of anthropometric indices and blood pressure was conducted; fasting blood glucose and lipid profile were measured; and cMetS score was computed. Standardized residuals (z-scores) were calculated for MetS components. A higher cMetS score indicates a less favorable metabolic profile. Linear regression models were applied to determine the association between cMetS and anthropometric indices. The study participants consisted of 3843 children and adolescents (52.3% boys) with mean (SD) age of 12.45 ± 3.04 years. All anthropometric indices had positive correlation with standardized scores of mean arterial pressure, waist circumference and cMetS (P < 0.05). Standardized scores of triglycerides were positively correlated with weight and body mass index (P < 0.05). In multivariate model, general and abdominal obesity, as well as high circumferences of neck, wrist, and hip circumferences increased the standardized cMetS risk score to 1.8, 1.9, 1.6, 1.5 and 1.5, respectively (P < 0.05 for all variables). The results demonstrated that higher anthropometric indices are associated with higher cMetS risk score in children and adolescents. This information could be valuable for screening and prevention of MetS at population level. V, cross-sectional descriptive study (National surveillance study).
Compliance with referral of sick children: a survey in five districts of Afghanistan.
Newbrander, William; Ickx, Paul; Werner, Robert; Mujadidi, Farooq
2012-04-27
Recognition and referral of sick children to a facility where they can obtain appropriate treatment is critical for helping reduce child mortality. A well-functioning referral system and compliance by caretakers with referrals are essential. This paper examines referral patterns for sick children, and factors that influence caretakers' compliance with referral of sick children to higher-level health facilities in Afghanistan. The study was conducted in 5 rural districts of 5 Afghan provinces using interviews with parents or caretakers in 492 randomly selected households with a child from 0 to 2 years old who had been sick within the previous 2 weeks with diarrhea, acute respiratory infection (ARI), or fever. Data collectors from local nongovernmental organizations used a questionnaire to assess compliance with a referral recommendation and identify barriers to compliance. The number of referrals, 99 out of 492 cases, was reasonable. We found a high number of referrals by community health workers (CHWs), especially for ARI. Caretakers were more likely to comply with referral recommendations from community members (relative, friend, CHW, traditional healer) than with recommendations from health workers (at public clinics and hospitals or private clinics and pharmacies). Distance and transportation costs did not create barriers for most families of referred sick children. Although the average cost of transportation in a subsample of 75 cases was relatively high (US$11.28), most families (63%) who went to the referral site walked and hence paid nothing. Most caretakers (75%) complied with referral advice. Use of referral slips by health care providers was higher for urgent referrals, and receiving a referral slip significantly increased caretakers' compliance with referral. Use of referral slips is important to increase compliance with referral recommendations in rural Afghanistan.
NIMEFI: gene regulatory network inference using multiple ensemble feature importance algorithms.
Ruyssinck, Joeri; Huynh-Thu, Vân Anh; Geurts, Pierre; Dhaene, Tom; Demeester, Piet; Saeys, Yvan
2014-01-01
One of the long-standing open challenges in computational systems biology is the topology inference of gene regulatory networks from high-throughput omics data. Recently, two community-wide efforts, DREAM4 and DREAM5, have been established to benchmark network inference techniques using gene expression measurements. In these challenges the overall top performer was the GENIE3 algorithm. This method decomposes the network inference task into separate regression problems for each gene in the network in which the expression values of a particular target gene are predicted using all other genes as possible predictors. Next, using tree-based ensemble methods, an importance measure for each predictor gene is calculated with respect to the target gene and a high feature importance is considered as putative evidence of a regulatory link existing between both genes. The contribution of this work is twofold. First, we generalize the regression decomposition strategy of GENIE3 to other feature importance methods. We compare the performance of support vector regression, the elastic net, random forest regression, symbolic regression and their ensemble variants in this setting to the original GENIE3 algorithm. To create the ensemble variants, we propose a subsampling approach which allows us to cast any feature selection algorithm that produces a feature ranking into an ensemble feature importance algorithm. We demonstrate that the ensemble setting is key to the network inference task, as only ensemble variants achieve top performance. As second contribution, we explore the effect of using rankwise averaged predictions of multiple ensemble algorithms as opposed to only one. We name this approach NIMEFI (Network Inference using Multiple Ensemble Feature Importance algorithms) and show that this approach outperforms all individual methods in general, although on a specific network a single method can perform better. An implementation of NIMEFI has been made publicly available.
Compliance with referral of sick children: a survey in five districts of Afghanistan
2012-01-01
Background Recognition and referral of sick children to a facility where they can obtain appropriate treatment is critical for helping reduce child mortality. A well-functioning referral system and compliance by caretakers with referrals are essential. This paper examines referral patterns for sick children, and factors that influence caretakers’ compliance with referral of sick children to higher-level health facilities in Afghanistan. Methods The study was conducted in 5 rural districts of 5 Afghan provinces using interviews with parents or caretakers in 492 randomly selected households with a child from 0 to 2 years old who had been sick within the previous 2 weeks with diarrhea, acute respiratory infection (ARI), or fever. Data collectors from local nongovernmental organizations used a questionnaire to assess compliance with a referral recommendation and identify barriers to compliance. Results The number of referrals, 99 out of 492 cases, was reasonable. We found a high number of referrals by community health workers (CHWs), especially for ARI. Caretakers were more likely to comply with referral recommendations from community members (relative, friend, CHW, traditional healer) than with recommendations from health workers (at public clinics and hospitals or private clinics and pharmacies). Distance and transportation costs did not create barriers for most families of referred sick children. Although the average cost of transportation in a subsample of 75 cases was relatively high (US$11.28), most families (63%) who went to the referral site walked and hence paid nothing. Most caretakers (75%) complied with referral advice. Use of referral slips by health care providers was higher for urgent referrals, and receiving a referral slip significantly increased caretakers’ compliance with referral. Conclusions Use of referral slips is important to increase compliance with referral recommendations in rural Afghanistan. PMID:22540424
Park, Yoon Soo; Hyderi, Abbas; Bordage, Georges; Xing, Kuan; Yudkowsky, Rachel
2016-10-01
Recent changes to the patient note (PN) format of the United States Medical Licensing Examination have challenged medical schools to improve the instruction and assessment of students taking the Step-2 clinical skills examination. The purpose of this study was to gather validity evidence regarding response process and internal structure, focusing on inter-rater reliability and generalizability, to determine whether a locally-developed PN scoring rubric and scoring guidelines could yield reproducible PN scores. A randomly selected subsample of historical data (post-encounter PN from 55 of 177 medical students) was rescored by six trained faculty raters in November-December 2014. Inter-rater reliability (% exact agreement and kappa) was calculated for five standardized patient cases administered in a local graduation competency examination. Generalizability studies were conducted to examine the overall reliability. Qualitative data were collected through surveys and a rater-debriefing meeting. The overall inter-rater reliability (weighted kappa) was .79 (Documentation = .63, Differential Diagnosis = .90, Justification = .48, and Workup = .54). The majority of score variance was due to case specificity (13 %) and case-task specificity (31 %), indicating differences in student performance by case and by case-task interactions. Variance associated with raters and its interactions were modest (<5 %). Raters felt that justification was the most difficult task to score and that having case and level-specific scoring guidelines during training was most helpful for calibration. The overall inter-rater reliability indicates high level of confidence in the consistency of note scores. Designs for scoring notes may optimize reliability by balancing the number of raters and cases.
A study of National Health Service management of chronic osteoarthritis and low back pain.
Hart, Oliver R; Uden, Ruth M; McMullan, James E; Ritchie, Mark S; Williams, Timothy D; Smith, Blair H
2015-04-01
To describe treatment and referral patterns and National Health Service resource use in patients with chronic pain associated with low back pain or osteoarthritis, from a Primary Care perspective. Osteoarthritis and low back pain are the two commonest debilitating causes of chronic pain, with high health and social costs, and particularly important in primary care. Understanding current practice and resource use in their management will inform health service and educational requirements and the design and optimisation of future care. Multi-centre, retrospective, descriptive study of adults (⩾18 years) with chronic pain arising from low back pain or osteoarthritis, identified through primary care records. Five general practices in Scotland, England (two), Northern Ireland and Wales. All patients with a diagnosis of low back pain or osteoarthritis made on or before 01/09/2006 who had received three or more prescriptions for pain medication were identified and a sub-sample randomly selected then consented to an in-depth review of their medical records (n=264). Data on management of chronic pain were collected retrospectively from patients' records for three years from diagnosis ('newly diagnosed' patients) or for the most recent three years ('established' patients). Patients received a wide variety of pain medications with no overall common prescribing pattern. GP visits represented the majority of the resource use and 'newly diagnosed' patients were significantly more likely to visit their GP for pain management than 'established' patients. Although 'newly diagnosed' patients had more referrals outside the GP practice, the number of visits to secondary care for pain management was similar for both groups. This retrospective study confirmed the complexity of managing these causes of chronic pain and the associated high resource use. It provides an in-depth picture of prescribing and referral patterns and of resource use.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jester, Sebastian; Schneider, Donald P.; Richards, Gordon T.
The author investigates the extent to which the Palomar-Green (PG) Bright Quasar Survey (BQS) is complete and representative of the general quasar population by comparing with imaging and spectroscopy from the Sloan Digital Sky Survey. A comparison of SDSS and PG photometry of both stars and quasars reveals the need to apply a color and magnitude recalibration to the PG data. Using the SDSS photometric catalog, they define the PG's parent sample of objects that are not main-sequence stars and simulate the selection of objects from this parent sample using the PG photometric criteria and errors. This simulation shows thatmore » the effective U-B cut in the PG survey is U-B < -0.71, implying a color-related incompleteness. As the color distribution of bright quasars peaks near U-B = -0.7 and the 2-{sigma} error in U-B is comparable to the full width of the color distribution of quasars, the color incompleteness of the BQS is approximately 50% and essentially random with respect to U-B color for z < 0.5. There is however, a bias against bright quasars at 0.5 < z < 1, which is induced by the color-redshift relation of quasars (although quasars at z > 0.5 are inherently rare in bright surveys in any case). They find no evidence for any other systematic incompleteness when comparing the distributions in color, redshift, and FIRST radio properties of the BQS and a BQS-like subsample of the SDSS quasar sample. However, the application of a bright magnitude limit biases the BQS toward the inclusion of objects which are blue in g-i, in particular compared to the full range of g-i colors found among the i-band limited SDSS quasars, and even at i-band magnitudes comparable to those of the BQS objects.« less
Nnko, Happiness J; Ngonyoka, Anibariki; Salekwa, Linda; Estes, Anna B; Hudson, Peter J; Gwakisa, Paul S; Cattadori, Isabella M
2017-06-01
Tsetse flies, the vectors of trypanosomiasis, represent a threat to public health and economy in sub-Saharan Africa. Despite these concerns, information on temporal and spatial dynamics of tsetse and trypanosomes remain limited and may be a reason that control strategies are less effective. The current study assessed the temporal variation of the relative abundance of tsetse fly species and trypanosome prevalence in relation to climate in the Maasai Steppe of Tanzania in 2014-2015. Tsetse flies were captured using odor-baited Epsilon traps deployed in ten sites selected through random subsampling of the major vegetation types in the area. Fly species were identified morphologically and trypanosome species classified using PCR. The climate dataset was acquired from the African Flood and Drought Monitor repository. Three species of tsetse flies were identified: G. swynnertoni (70.8%), G. m. morsitans (23.4%), and G.pallidipes (5.8%). All species showed monthly changes in abundance with most of the flies collected in July. The relative abundance of G. m. morsitans and G. swynnertoni was negatively correlated with maximum and minimum temperature, respectively. Three trypanosome species were recorded: T. vivax (82.1%), T. brucei (8.93%), and T. congolense (3.57%). The peak of trypanosome infections in the flies was found in October and was three months after the tsetse abundance peak; prevalence was negatively correlated with tsetse abundance. A strong positive relationship was found between trypanosome prevalence and temperature. In conclusion, we find that trypanosome prevalence is dependent on fly availability, and temperature drives both tsetse fly relative abundance and trypanosome prevalence. © 2017 The Society for Vector Ecology.
Children who run away from home: risks for suicidal behavior and substance misuse.
Meltzer, Howard; Ford, Tamsin; Bebbington, Paul; Vostanis, Panos
2012-11-01
The primary aim of this study is to examine the extent to which running away from home as a child is associated with behavioral problems and victimization during childhood and with suicidal behavior and substance abuse during early adulthood. A random probability sample comprising 7,461 respondents was interviewed for the 2007 survey of psychiatric morbidity of adults in England. A subsample of 16- to 34-year-old individuals was selected for secondary analysis (N = 2,247). All survey respondents were asked whether they had run away from home and asked specific questions on being physically, emotionally and sexually abused as children. They were also asked about suicidal behavior and alcohol and drug dependence in early adulthood. Approximately 7% of 16- to 34-year-old individuals reported running away from home before the age of 16 years, with higher rates in women than in men (9.8% compared with 5.3%). Overall, 45.3% reported being bullied, 25.3% experienced violence at home, and 8.8% reported unwanted sexual intercourse. Runaways were far more likely than other children to have suffered victimization and family difficulties and to exhibit behavioral problems. Adults who reported running away from home were three times more likely than other adults to have thought about or attempted suicide, but the relationship with substance abuse was far less pronounced. Sexual, physical, and emotional abuse, along with family difficulties, can all impact children who run away from home. Running away from home was strongly associated with suicidal behavior in adulthood, regardless of other childhood adversities. Copyright © 2012 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.
Walsh, Raoul A; Tzelepis, Flora; Paul, Christine L; McKenzie, Jeanie
2002-12-01
To assess community knowledge, attitudes and practices in relation to environmental tobacco smoke (ETS) especially in homes, private motor vehicles and licensed premises, and to document levels of support for further government legislation. 656 persons aged 18 years and over, a sub-sample in a computer-assisted telephone survey of 2,087 randomly selected respondents across NSW, answered 12 ETS-specific questions. The whole sample was asked demographic, smoking status and household membership questions. The overall response rate was 61.4% (consent rate 75.4%). Overall, 32.8% (95% CI 27.8-37.8) of children aged 0-4 years in the households surveyed were reported to live with at least one smoker. Agreement about ETS hazards was lowest in relation to child ear problems (31.2%) and sudden infant death syndrome (50.6%). Complete bans on smoking were reported in 69.9% of homes and 77.1% of private motor vehicles. The percentages favouring total bans in homes (p < 0.001) and private motor vehicles (p < 0.001) were significantly lower among smokers than non-smokers. Overall, 55.8% supported legislation to ban smoking in private vehicles carrying children. The majority support restrictions on smoking in non-eating areas of licensed clubs (88.7%) and hotels (84.8%). Overall, the data indicate a ban on smoking in licensed premises is likely to increase business. Smoking is banned in most NSW homes and private motor vehicles. Acceptance of ETS risks is high but there are important knowledge gaps. Considerable support exists for further government regulation of ETS. Media campaigns are likely to reinforce a public environment already receptive of the need for more government ETS restrictions.
Topology Analysis of the Sloan Digital Sky Survey. I. Scale and Luminosity Dependence
NASA Astrophysics Data System (ADS)
Park, Changbom; Choi, Yun-Young; Vogeley, Michael S.; Gott, J. Richard, III; Kim, Juhan; Hikage, Chiaki; Matsubara, Takahiko; Park, Myeong-Gu; Suto, Yasushi; Weinberg, David H.; SDSS Collaboration
2005-11-01
We measure the topology of volume-limited galaxy samples selected from a parent sample of 314,050 galaxies in the Sloan Digital Sky Survey (SDSS), which is now complete enough to describe the fully three-dimensional topology and its dependence on galaxy properties. We compare the observed genus statistic G(νf) to predictions for a Gaussian random field and to the genus measured for mock surveys constructed from new large-volume simulations of the ΛCDM cosmology. In this analysis we carefully examine the dependence of the observed genus statistic on the Gaussian smoothing scale RG from 3.5 to 11 h-1 Mpc and on the luminosity of galaxies over the range -22.50
Cross, Wendi; West, Jennifer; Wyman, Peter A.; Schmeelk-Cone, Karen; Xia, Yinglin; Tu, Xin; Teisl, Michael; Brown, C. Hendricks; Forgatch, Marion
2014-01-01
Current measures of implementer fidelity often fail to adequately measure core constructs of adherence and competence, and their relationship to outcomes can be mixed. To address these limitations, we used observational methods to assess these constructs and their relationships to proximal outcomes in a randomized trial of a school-based preventive intervention (Rochester Resilience Project) designed to strengthen emotion self-regulation skills in 1st–3rd graders with elevated aggressive-disruptive behaviors. Within the intervention group (n = 203), a subsample (n = 76) of students was selected to reflect the overall sample. Implementers were 10 paraprofessionals. Videotaped observations of three lessons from Year 1 of the intervention (14 lessons) were coded for each implementer-child dyad on Adherence (content) and Competence (quality). Using multi-level modeling we examined how much of the variance in the fidelity measures was attributed to implementer and to the child within implementer. Both measures had large and significant variance accounted for by implementer (Competence, 68%; Adherence, 41%); child within implementer did not account for significant variance indicating that ratings reflected stable qualities of the implementer rather than the child. Raw Adherence and Competence scores shared 46% of variance (r = .68). Controlling for baseline differences and age, the amount (Adherence) and quality (Competence) of program delivered predicted children’s enhanced response to the intervention on both child and parent reports after six months, but not on teacher report of externalizing behavior. Our findings support the use of multiple observations for measuring fidelity and that adherence and competence are important components of fidelity which could be assessed by many programs using these methods. PMID:24736951
Smoking characteristics of Polish immigrants in Dublin.
Kabir, Zubair; Clarke, Vanessa; Keogan, Sheila; Currie, Laura M; Zatonski, Witold; Clancy, Luke
2008-12-31
This study examined two main hypotheses: a) Polish immigrants' smoking estimates are greater than their Irish counterparts (b) Polish immigrants purchasing cigarettes from Poland smoke "heavier" (>/= 20 cigarettes a day) when compared to those purchasing cigarettes from Ireland. The study also set out to identify significant predictors of 'current' smoking (some days and everyday) among the Polish immigrants. Dublin residents of Polish origin (n = 1,545) completed a previously validated Polish questionnaire in response to an advertisement in a local Polish lifestyle magazine over 5 weekends (July-August, 2007). The Office of Tobacco Control telephone-based monthly survey data were analyzed for the Irish population in Dublin for the same period (n = 484). Age-sex adjusted smoking estimates were: 47.6% (95% Confidence Interval [CI]: 47.3%; 48.0%) among the Poles and 27.8% (95% CI: 27.2%; 28.4%) among the general Irish population (p < 0.001). Of the 57% of smokers (n = 345/606) who purchased cigarettes solely from Poland and the 33% (n = 198/606) who purchased only from Ireland, 42.6% (n = 147/345) and 41.4% (n = 82/198) were "heavy" smokers, respectively (p = 0.79). Employment (Odds Ratio [OR]: 2.89; 95% CI: 1.25-6.69), lower education (OR: 3.76; 95%CI: 2.46-5.74), and a longer stay in Ireland (>24 months) were significant predictors of current smoking among the Poles. An objective validation of the self-reported smoking history of a randomly selected sub-sample immigrant group, using expired carbon monoxide (CO) measurements, showed a highly significant correlation coefficient (r = 0.64) of expired CO levels with the reported number of cigarettes consumed (p < 0.0001). Polish immigrants' smoking estimates are higher than their Irish counterparts, and particularly if employed, with only primary-level education, and are overseas >2 years.
Psychological Resources and Glucoregulation in Japanese Adults: Findings from MIDJA
Boylan, Jennifer Morozink; Tsenkova, Vera K.; Miyamoto, Yuri; Ryff, Carol D.
2017-01-01
Objective To examine associations between glucoregulation and three categories of psychological resources: hedonic well-being (i.e., life satisfaction, positive affect), eudaimonic well-being (i.e., personal growth, purpose in life, ikigai) and interdependent well-being (i.e., gratitude, peaceful disengagement, adjustment) among Japanese adults. The question is important given increases in rates of type 2 diabetes in Japan in recent years, combined with the fact that most prior studies linking psychological resources to better physical health have utilized Western samples. Methods Data came from the Midlife in Japan (MIDJA) Study involving randomly selected participants from the Tokyo metropolitan area, a subsample of whom completed biological data collection (N=382; 56.0% female; M(SD)age = 55.5(14.0) years). Glycosylated hemoglobin (HbA1c) was the outcome. Models adjusted for age, gender, educational attainment, smoking, alcohol, chronic conditions, body mass index, use of anti-diabetic medication, and negative affect. Results Purpose in life (β = −.102, p = .022) was associated with lower HbA1c, and peaceful disengagement (β = .124, p = .004) was associated with higher HbA1c in fully adjusted models. Comparable to the effects of BMI, a one standard deviation change in well-being was associated with a .1% change in HbA1c. Conclusions Associations among psychological resources and glucoregulation were mixed. Healthy glucoregulation was evident among Japanese adults with higher levels of purpose in life and lower levels of peaceful disengagement, thereby extending prior research from the U.S. The results emphasize the need for considering sociocultural contexts in which psychological resources are experienced in order to understand linkages to physical health. PMID:28192004
Psychological resources and glucoregulation in Japanese adults: Findings from MIDJA.
Boylan, Jennifer Morozink; Tsenkova, Vera K; Miyamoto, Yuri; Ryff, Carol D
2017-05-01
To examine associations between glucoregulation and 3 categories of psychological resources: hedonic well-being (i.e., life satisfaction, positive affect), eudaimonic well-being (i.e., personal growth, purpose in life, ikigai), and interdependent well-being (i.e., gratitude, peaceful disengagement, adjustment) among Japanese adults. The question is important given increases in rates of type 2 diabetes in Japan in recent years, combined with the fact that most prior studies linking psychological resources to better physical health have utilized Western samples. Data came from the Midlife in Japan Study involving randomly selected participants from the Tokyo metropolitan area, a subsample of whom completed biological data collection (N = 382; 56.0% female; M(SD)age = 55.5(14.0) years). Glycosylated hemoglobin (HbA1c) was the outcome. Models adjusted for age, gender, educational attainment, smoking, alcohol, chronic conditions, body mass index (BMI), use of antidiabetic medication, and negative affect. Purpose in life (β = -.104, p = .021) was associated with lower HbA1c, and peaceful disengagement (β = .129, p = .003) was associated with higher HbA1c in fully adjusted models. Comparable to the effects of BMI, a 1 standard deviation change in well-being was associated with a .1% change in HbA1c. Associations among psychological resources and glucoregulation were mixed. Healthy glucoregulation was evident among Japanese adults with higher levels of purpose in life and lower levels of peaceful disengagement, thereby extending prior research from the United States. The results emphasize the need for considering sociocultural contexts in which psychological resources are experienced in order to understand linkages to physical health. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Galera-Martínez, Rafael; García-García, Emilio; Vázquez-López, M Ángeles; Ortiz-Pérez, María; Ruiz-Sánchez, Ana Mar; Martín-González, Manuel; Garrido-Fernández, Pablo; Bonillo-Perales, Antonio
2015-08-01
there are few studies on the prevalence of metabolic syndrome (MetS) in European adolescent populations, and some have reported a higher prevalence in the Mediterranean basin area. Our objective was to examine the prevalence of MetS in adolescents in a Mediterranean city of Spain, comparing two different definitions of MetS and the associated risk factors. a cross-sectional population-based study was conducted among 379 adolescents aged 12-16.9 years, selected using a random sampling method. Anthropometric measurements and fasting blood samples were obtained. The definitions of MetS used were that of the National Cholesterol Education Program's Adult Treatment Panel III (NCEP-ATPIII) and that of the International Diabetes Federation (IDF). Kappa coefficient was used to measure the agreement between definitions and a multivariate logistic regression model to determine the associated risk factors. the prevalence of MetS was 5.7% (95%CI 3.33-8.07) according to the NCEP-ATPIII definition and 3.8% (95%CI 1.85-5.75) according to the IDF definition. No differences between the sexes or by age groups were found. The agreement between the two definitions was very good (kappa 0.815), especially in the obese subsample, but was lower in normal weight adolescents (kappa 0.497). Insulin resistance and obesity were associated with both definitions. the prevalence of MetS in our adolescent population is higher than the European media. Although the overall agreement between both definitions was very good, the prevalence was higher using the NCEP-ATPIII criteria. Independently of the definition used, obesity and insulin resistance were risk factors for MetS. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.
Kator, H; Rhodes, M
2001-06-01
Declining oyster (Crassostrea virginica) production in the Chesapeake Bay has stimulated aquaculture based on floats for off-bottom culture. While advantages of off-bottom culture are significant, the increased use of floating containers raises public health and microbiological concerns, because oysters in floats may be more susceptible to fecal contamination from storm runoff compared to those cultured on-bottom. We conducted four commercial-scale studies with market-size oysters naturally contaminated with fecal coliforms (FC) and a candidate viral indicator, F-specific RNA (FRNA) coliphage. To facilitate sampling and to test for location effects, 12 replicate subsamples, each consisting of 15 to 20 randomly selected oysters in plastic mesh bags, were placed at four characteristic locations within a 0.6- by 3.0-m "Taylor" float, and the remaining oysters were added to a depth not exceeding 15.2 cm. The float containing approximately 3,000 oysters was relaid in the York River, Virginia, for 14 days. During relay, increases in shellfish FC densities followed rain events such that final mean levels exceeded initial levels or did not meet an arbitrary product end point of 50 FC/100 ml. FRNA coliphage densities decreased to undetectable levels within 14 days (16 to 28 degrees C) in all but the last experiment, when temperatures fell between 12 and 16 degrees C. Friedman (nonparametric analysis of variance) tests performed on FC/Escherichia coli and FRNA densities indicated no differences in counts as a function of location within the float. The public health consequences of these observations are discussed, and future research and educational needs are identified.
He, Hua; McDermott, Michael P.
2012-01-01
Sensitivity and specificity are common measures of the accuracy of a diagnostic test. The usual estimators of these quantities are unbiased if data on the diagnostic test result and the true disease status are obtained from all subjects in an appropriately selected sample. In some studies, verification of the true disease status is performed only for a subset of subjects, possibly depending on the result of the diagnostic test and other characteristics of the subjects. Estimators of sensitivity and specificity based on this subset of subjects are typically biased; this is known as verification bias. Methods have been proposed to correct verification bias under the assumption that the missing data on disease status are missing at random (MAR), that is, the probability of missingness depends on the true (missing) disease status only through the test result and observed covariate information. When some of the covariates are continuous, or the number of covariates is relatively large, the existing methods require parametric models for the probability of disease or the probability of verification (given the test result and covariates), and hence are subject to model misspecification. We propose a new method for correcting verification bias based on the propensity score, defined as the predicted probability of verification given the test result and observed covariates. This is estimated separately for those with positive and negative test results. The new method classifies the verified sample into several subsamples that have homogeneous propensity scores and allows correction for verification bias. Simulation studies demonstrate that the new estimators are more robust to model misspecification than existing methods, but still perform well when the models for the probability of disease and probability of verification are correctly specified. PMID:21856650
NASA Astrophysics Data System (ADS)
Furnell, Kate E.; Collins, Chris A.; Kelvin, Lee S.; Clerc, Nicolas; Baldry, Ivan K.; Finoguenov, Alexis; Erfanianfar, Ghazaleh; Comparat, Johan; Schneider, Donald P.
2018-04-01
We present a sample of 329 low to intermediate redshift (0.05 < z < 0.3) brightest cluster galaxies (BCGs) in X-ray selected clusters from the SPectroscopic IDentification of eRosita Sources (SPIDERS) survey, a spectroscopic survey within Sloan Digital Sky Survey-IV (SDSS-IV). We define our BCGs by simultaneous consideration of legacy X-ray data from ROSAT, maximum likelihood outputs from an optical cluster-finder algorithm and visual inspection. Using SDSS imaging data, we fit Sérsic profiles to our BCGs in three bands (g, r, i) with SIGMA, a GALFIT-based software wrapper. We examine the reliability of our fits by running our pipeline on ˜104 psf-convolved model profiles injected into 8 random cluster fields; we then use the results of this analysis to create a robust subsample of 198 BCGs. We outline three cluster properties of interest: overall cluster X-ray luminosity (LX), cluster richness as estimated by REDMAPPER (λ) and cluster halo mass (M200), which is estimated via velocity dispersion. In general, there are significant correlations with BCG stellar mass between all three environmental properties, but no significant trends arise with either Sérsic index or effective radius. There is no major environmental dependence on the strength of the relation between effective radius and BCG stellar mass. Stellar mass therefore arises as the most important factor governing BCG morphology. Our results indicate that our sample consists of a large number of relaxed, mature clusters containing broadly homogeneous BCGs up to z ˜ 0.3, suggesting that there is little evidence for much ongoing structural evolution for BCGs in these systems.
Diouf, Adama; Thiam, Mbeugué; Idohou-Dossou, Nicole; Diongue, Ousmane; Mégné, Ndé; Diallo, Khady; Sembène, Pape Malick; Wade, Salimata
2016-01-01
Background: Physical inactivity and sedentary lifestyles are major risk factors of childhood obesity. This study aimed to measure physical activity (PA) levels by accelerometer and Physical Activity Questionnaire for Older Children (PAQ-C) among Senegalese school children and the relation with Body Mass Index (BMI) and body composition. Methodology: 156 pupils 8–11 years old were randomly selected in four elementary public schools of Dakar. BMI z-score was used to categorize children according to their weight status. PA was measured by PAQ-C in the 156 pupils and by accelerometer (Actigraph GT3X+, Pensacola, FL, USA) in a subsample of 42 children. Body composition was determined by deuterium dilution method. Results: PAQ-C results were comparable in the 156 and 42 pupils. The 42 pupils presented a light activity measured by accelerometer, while PAQ-C classified the majority of them (57%; n = 24) in the moderate PA level. Children spent most of their time (min/day) in sedentary activities and light activities than in moderate and intense activity levels. Accumulation of 60 min/day Moderate-to-Vigorous Physical Activity (MVPA) was achieved by 54.8% (n = 23) of the pupils. MVPA decreased in girls in relation to their body fatness. There was a significant difference in MVPA between boys and girls. Similarly, overweight/obese (45 ± 16 min/day) children had lower MVPA than their normal and underweight peers (88 ± 34 and 74 ± 36 min/day, respectively; p = 0.004). Conclusions: The two methods are inconsistent for measuring light and moderate PA levels. Although PAQ-C is an uncomplicated routine method, various activities were not adapted for genuine activities in Senegalese children and therefore needs to be validated in African children. PMID:27735876
2013-01-01
Background Low back pain (LBP) is common among office workers. A number of studies have established a relationship between Christianity and physical and mental health outcomes among chronic pain patients. The purpose of this study was to examine the relationship between the religious beliefs and practices of Buddhism and disability and psychological stress in office workers with chronic LBP. Methods A cross-sectional survey was conducted with a self-administered questionnaire delivered by hand to 463 office workers with chronic LBP. Saliva samples were collected from a randomly selected sub-sample of respondents (n=96). Disability due to LBP was assessed using the Roland-Morris Disability Questionnaire and psychological stress was assessed based on salivary cortisol. Two hierarchical regression models were built to determine how much variance in disability and psychological stress could be explained by religious beliefs and practices of Buddhism variables after controlling for potential confounder variables. Results Only 6% of variance in psychological stress was accounted for by the religious beliefs and practices of Buddhism. Those with high religiousness experienced lower psychological stress. No association between the religious beliefs and practices of Buddhism and disability level was found. Depressive symptoms were attributed to both psychological stress and disability status in our study population. Conclusions The findings suggest that, although being religious may improve the psychological condition in workers with chronic LBP, its effect is insufficient to reduce disability due to illness. Further research should examine the role of depression as a mediator of the effect of psychological stress on disability in patients with chronic LBP. PMID:23324474
Outbreeding depression in hybrids between odd-and even-broodyear pink salmon
Gharrett, A.J.; Smoker, W.W.; Reisenbichler, R.R.; Taylor, S.G.
1999-01-01
Fewer F2 hybrids between even- and odd-broodline pink salmon (Oncorhynchus gorbuscha), which are lines that are genetically isolated by their strict two-year life cycle, survived than did F2 controls, indicating outbreeding depression. Cryopreserved sperm of 40 broodyear 1990 males and of 40 broodyear 1991 males fertilized equal subsamples of eggs from 40 broodyear 1992 females. Return rates of F1 hybrids (1.73%) and controls (1.63%) in 1994 did not differ significantly (P=0.30). F2 hybrid and control crosses were made from 40 males and 40 females selected at random from each return group. Offspring were differentially marked and released. In 1996, returns differed significantly (P=0.011) between hybrids (n=34, 0.34%) and controls (n=44, 0.42%). The low rate of return of the control fish was similar to the measured return of a much larger group of tagged Auke Creek pink salmon, and probably not an artifact of the experiment. Although no increase in fluctuating asymmetry of paired meristic counts was observed in either F1or F2 hybrids, size and some meristic counts of hybrids exceed measurements of controls, suggesting heterosis for those traits. The observations of decreased survival in F2 hybrids confirm previous work [Gharrett, A.J., Smoker, W.W., 1991. Two generations of hybrids between even- and odd-year pink salmon (O. gorbuscha). Canadian Journal of Fisheries and Aquatic Science 48(9) 1744–1749]. Although genetic divergence between pink salmon broodlines is large and outbreeding depression might be expected in such unlikely hybrids, the results document the occurrence of outbreeding depression in salmon and signal caution in making management and aquacultural decisions that may create the possibility of outbreeding depression in self-sustaining or cultured populations.
Social Network Behavior and Engagement Within a Smoking Cessation Facebook Page.
Cole-Lewis, Heather; Perotte, Adler; Galica, Kasia; Dreyer, Lindy; Griffith, Christopher; Schwarz, Mary; Yun, Christopher; Patrick, Heather; Coa, Kisha; Augustson, Erik
2016-08-02
Social media platforms are increasingly being used to support individuals in behavior change attempts, including smoking cessation. Examining the interactions of participants in health-related social media groups can help inform our understanding of how these groups can best be leveraged to facilitate behavior change. The aim of this study was to analyze patterns of participation, self-reported smoking cessation length, and interactions within the National Cancer Institutes' Facebook community for smoking cessation support. Our sample consisted of approximately 4243 individuals who interacted (eg, posted, commented) on the public Smokefree Women Facebook page during the time of data collection. In Phase 1, social network visualizations and centrality measures were used to evaluate network structure and engagement. In Phase 2, an inductive, thematic qualitative content analysis was conducted with a subsample of 500 individuals, and correlational analysis was used to determine how participant engagement was associated with self-reported session length. Between February 2013 and March 2014, there were 875 posts and 4088 comments from approximately 4243 participants. Social network visualizations revealed the moderator's role in keeping the community together and distributing the most active participants. Correlation analyses suggest that engagement in the network was significantly inversely associated with cessation status (Spearman correlation coefficient = -0.14, P=.03, N=243). The content analysis of 1698 posts from 500 randomly selected participants identified the most frequent interactions in the community as providing support (43%, n=721) and announcing number of days smoke free (41%, n=689). These findings highlight the importance of the moderator for network engagement and provide helpful insights into the patterns and types of interactions participants are engaging in. This study adds knowledge of how the social network of a smoking cessation community behaves within the confines of a Facebook group.
Diouf, Adama; Thiam, Mbeugué; Idohou-Dossou, Nicole; Diongue, Ousmane; Mégné, Ndé; Diallo, Khady; Sembène, Pape Malick; Wade, Salimata
2016-10-10
Background : Physical inactivity and sedentary lifestyles are major risk factors of childhood obesity. This study aimed to measure physical activity (PA) levels by accelerometer and Physical Activity Questionnaire for Older Children (PAQ-C) among Senegalese school children and the relation with Body Mass Index (BMI) and body composition. Methodology : 156 pupils 8-11 years old were randomly selected in four elementary public schools of Dakar. BMI z -score was used to categorize children according to their weight status. PA was measured by PAQ-C in the 156 pupils and by accelerometer (Actigraph GT3X+, Pensacola, FL, USA) in a subsample of 42 children. Body composition was determined by deuterium dilution method. Results : PAQ-C results were comparable in the 156 and 42 pupils. The 42 pupils presented a light activity measured by accelerometer, while PAQ-C classified the majority of them (57%; n = 24) in the moderate PA level. Children spent most of their time (min/day) in sedentary activities and light activities than in moderate and intense activity levels. Accumulation of 60 min/day Moderate-to-Vigorous Physical Activity (MVPA) was achieved by 54.8% ( n = 23) of the pupils. MVPA decreased in girls in relation to their body fatness. There was a significant difference in MVPA between boys and girls. Similarly, overweight/obese (45 ± 16 min/day) children had lower MVPA than their normal and underweight peers (88 ± 34 and 74 ± 36 min/day, respectively; p = 0.004). Conclusions : The two methods are inconsistent for measuring light and moderate PA levels. Although PAQ-C is an uncomplicated routine method, various activities were not adapted for genuine activities in Senegalese children and therefore needs to be validated in African children.
[Analysis of the body composition of Spanish women with fibromyalgia].
Aparicio, Virginia A; Ortega, Francisco B; Heredia, José M; Carbonell-Baeza, Ana; Delgado-Fernández, Manuel
2011-01-01
To describe the anthropometric profile and body composition of women from Southern Spain diagnosed with fibromyalgia (FM) and to compare the observed values with values from other studies conducted on FM patients and with national reference values. The body composition of 104 women diagnosed with FM was assessed using an eight-electrode impedance meter. The reliability of the body composition measurement was tested in a randomly selected sub-sample (n=28). The reliability study showed a test-retest systematic error close to zero in most of the parameters studied. The women with FM who were studied had a mean weight of 71.3±13.4 kg, height of 158±6 cm, body mass index of 28.6±5.1 kg/m(2), body fat mass of 38.6±7.6%, total body water of 31.6±3.8 l and muscle mass of 23.4±3.0 kg. In general, there were no substantial differences in weight and body mass index between women with FM and those analyzed in other Spanish and European studies involving FM patients, nor when they were compared with regional or national reference values. However, the prevalence of obesity in the women with FM under study was 33.7%, a higher figure than that from the national reference data for obesity in similarly aged women (i.e. 26,4%). The results suggest that obesity is a common condition in women diagnosed with FM, its prevalence in this population being higher than the national reference values. This study provides detailed information about the body composition characteristics of women with FM. Copyright © 2010 Elsevier España, S.L. All rights reserved.
Pelton, Gregory H; Harper, Oliver L; Roose, Steven P; Marder, Karen; D'Antonio, Kristina; Devanand, D P
2016-06-01
The objective of the study is to assess combined antidepressant and memantine treatment in older patients presenting with depression and cognitive impairment. Thirty-five depressed patients with cognitive impairment participated in this open-label pilot study. We evaluated whether, over a 48-week period, combined antidepressant (primarily es-citalopram) and memantine treatment was effective in the treatment of cognitive impairment and depression. Neuropsychological testing was performed, and antidepressant response monitored at baseline and at the 12, 24, and 48-week time points. Treatment with escitalopram (mean daily dose 18.62 mg, SD 5.15) and memantine (mean daily dose 13.62 mg, SD 6.67) was associated with improvement in Hamilton Depression Rating Scale scores over the 48-week study period. Patients demonstrated significant improvement in the primary outcome of cognitive performance (Selective Reminding Test total immediate recall; SRT-IR) over the 48-week treatment period (p = 0.0147). Significant improvement was also observed in measures of naming and verbal fluency but not in the other cognitive domains. One of the 35 patients (2.9%) converted to Alzheimer's disease over the 48-week treatment period. In the amnestic mild cognitive impairment subsample (n = 22), the conversion rate was 4.5%, a rate lower than in other reports of patients with DEP-CI. In this open-label trial, combined antidepressant and memantine treatment in patients with DEP-CI was associated with improved cognition and a low rate of conversion to dementia compared with published studies in patients with DEP-CI. Although limited by the open-label study design that incorporates practice effects that can improve cognitive test performance, the findings suggest the need for a larger randomized placebo-controlled trial. Copyright © 2015 John Wiley & Sons, Ltd.
The relationship between the FFM and personality disorders in a personnel selection sample.
Nederström, Mikael; Furnham, Adrian
2012-10-01
The relationships between the Five Factor Model (FFM) personality and personality disorders were investigated. A sample of real-life job applicants completed two personality questionnaires with different theoretical backgrounds in a psychological assessment center. The job applicants provided self-descriptions both on the FFM inventory and on a personality disorder trait inventory. A subsample of these candidates was interviewed by expert psychologists upon entrance to the assessment center. The psychologists assessed the same disorder traits of each target in job interviews. Both self-descriptions were used to predict the expert assessments. The results demonstrated considerable overlap between the FFM measures of normal and measures of abnormal personality in both samples and regardless of assessment method. © 2012 The Authors. Scandinavian Journal of Psychology © 2012 The Scandinavian Psychological Associations.
Age and disability: explaining the wage differential.
Gannon, Brenda; Munley, Margaret
2009-07-01
This paper estimates the level of explained and unexplained factors that contribute to the wage gap between workers with and without disabilities, providing benchmark estimates for Ireland. It separates out the confounding impact of productivity differences between disabled and non-disabled, by comparing wage differentials across three groups, disabled with limitations, disabled without limitations and non-disabled. Furthermore, data are analysed for the years 1995-2001 and two sub-samples pre and post 1998 allow us to decompose wage differentials before and after the Employment Equality Act 1998. Results are comparable to those of the UK and the unexplained component (upper bound of discrimination) is lower once we control for productivity differences. The lower bound level depends on the contribution of unobserved effects and the validity of the selection component in the decomposition model.
A randomized controlled trial of Moderation-Oriented Cue Exposure.
Heather, N; Brodie, J; Wale, S; Wilkinson, G; Luce, A; Webb, E; McCarthy, S
2000-07-01
A randomized controlled trial was conducted to examine the effectiveness of Moderation-Oriented Cue Exposure (MOCE) in comparison to Behavioral Self-Control Training (BSCT). The main hypothesis was that MOCE would be more effective than BSCT among a sample of problem drinkers aiming at moderate drinking. A subsidiary hypothesis was that MOCE would be relatively more effective than BSCT among problem drinkers with higher levels of alcohol dependence. Clients (N = 91; 75% men) were randomly allocated to either MOCE or BSCT. Treatment was delivered in weekly sessions by two trained therapists, in a nested design in which therapists switched to the alternative treatment modality approximately halfway through the trial. Follow-up was carried out 6 months following posttreatment assessment, with 85% successful contact. There was no evidence for the general superiority of MOCE over BSCT. The subsidiary hypothesis was not confirmed. A subsample of clients (n = 14) showing levels of dependence at baseline above the commonly accepted cut-point for a moderation goal (Severity of Alcohol Dependence Questionnaire [SADQ] > 29) showed outcomes at least as favorable as those below the cut-point. The validity of self-reports of alcohol consumption and problems was supported by significant relationships with liver function tests (gamma-glutamyl transferase and alanine transferase). These results provide no grounds for the replacement of BSCT by MOCE in routine, moderation-oriented treatment practice. Assuming they prefer it to abstinence and that it is not contra-indicated on other grounds, there seems no reason why clients showing a higher level of dependence (SADQ = 30-45) should not be offered a moderation goal.
Pandis, Nikolaos; Polychronopoulou, Argy; Eliades, Theodore
2011-12-01
Randomization is a key step in reducing selection bias during the treatment allocation phase in randomized clinical trials. The process of randomization follows specific steps, which include generation of the randomization list, allocation concealment, and implementation of randomization. The phenomenon in the dental and orthodontic literature of characterizing treatment allocation as random is frequent; however, often the randomization procedures followed are not appropriate. Randomization methods assign, at random, treatment to the trial arms without foreknowledge of allocation by either the participants or the investigators thus reducing selection bias. Randomization entails generation of random allocation, allocation concealment, and the actual methodology of implementing treatment allocation randomly and unpredictably. Most popular randomization methods include some form of restricted and/or stratified randomization. This article introduces the reasons, which make randomization an integral part of solid clinical trial methodology, and presents the main randomization schemes applicable to clinical trials in orthodontics.
NASA Astrophysics Data System (ADS)
Snowball, Ian; Almqvist, Bjarne; Lougheed, Bryan; Svensson, Anna; Wiers, Steffen; Herrero-Bervera, Emilio
2017-04-01
Inspired by palaeomagnetic data obtained from two sites (M0061 and M0062) cored during IODP Expedition 347 - Baltic Sea Paleoenvironment we studied the Hemsön Alloformation, which is a series of brackish water muds consisting of horizontal planar and parallel laminated (varved) silty clays free from bioturbation. We determined the anisotropy of magnetic susceptibility (AMS) and characteristic remanence (ChRM) directions of a total of 1,102 discrete samples cut from (i) IODP cores recovered by an Advanced Piston corer and (ii) a series of six sediment cores recovered from the same sites by a Kullenberg piston corer. Systematic core splitting, sub-sampling methods and measurements were applied to all sub-samples. We experimentally tested for field-impressed AMS of these muds, in which titanomagnetite carries magnetic remanence and this test was negative. The AMS is likely determined by paramagnetic minerals. As expected for horizontally bedded sediments, the vast majority of the K1 (maximum) and K2 (intermediate) axes had inclinations close to 0 degrees and the AMS shape parameter (T) indicates an oblate fabric. The declinations of the K1 and K2 directions of the sub-samples taken from Kullenberg cores showed a wide distribution around the bedding plane, with no preferred alignment along any specimen axis. Exceptions are samples from the upper 1.5 m of some of these cores, in which the K1 and K2 directions were vertical, the K3 (minimum) axis shallow and T became prolate. We conclude that the Kullenberg corer, which penetrated the top sediments with a pressure of approximately 15 bar, occasionally under-sampled during penetration and vertically stretched the top sediments. Sub-samples from the upper sections of Kullenberg cores had relatively steep ChRM inclinations and we rejected samples that had a prolate, vertically oriented AMS ellipsoid. Surprisingly, the declinations of the K1 axis of all sub-samples taken from IODP APC core sections, which were not oriented relative to each other with respect to azimuth, clustered tightly within the 90-270 degree specimen axis (K2 is within the 0-180 degree axis). This axis is the direction across each cores' split surface (i.e. perpendicular to the "push" direction of the sub-sampling boxes). The APC cores were characterized by various degrees of downwards bending of the planar varves towards the inner surface of the core liner. We conclude that the initial hydraulic pressure applied by the APC, which was consistently above 50 bar during Expedition 347, was needlessly high and created a conical sediment structure and the distinct alignment of the magnetic susceptibility axes along specimen axes. APC core sections with marked disturbances were characterized by ChRM inclinations below 65 degrees, which is a lower limit predicted by time varying geomagnetic field models for the duration of the Hemsö Alloformation (the most recent 6000 years). We rejected samples for palaeomagnetic purposes if the K1 inclination was steeper than 10 degrees. Our study highlights the added value of measuring AMS of discrete sub-samples as an independent control of the suitability of sediments as a source of palaeomagnetic data.
Gravely, Shannon; Nyamurungi, Kellen Namusisi; Kabwama, Steven Ndugwa; Okello, Gabriel; Robertson, Lindsay; Heng, Kelvin Khow Chuan; Ndikum, Achiri Elvis; Oginni, Adeniyi Samuel; Rusatira, Jean Christophe; Kakoulides, Socrates; Huffman, Mark D; Yusuf, Salim; Bianco, Eduardo
2018-01-05
This study evaluated knowledge, opinions and compliance related to Uganda's comprehensive smoke-free law among hospitality venues in Kampala Uganda. This multi-method study presents cross-sectional findings of the extent of compliance in the early phase of Uganda's comprehensive smoke-free law (2 months postimplementation; pre-enforcement). Bars, pubs and restaurants in Kampala Uganda. A two-stage stratified cluster sampling procedure was used to select hospitality sites stratified by all five divisions in Kampala. A total of 222 establishments were selected for the study. One hospitality representative from each of the visited sites agreed to take part in a face-to-face administered questionnaire. A subsample of hospitality venues were randomly selected for tobacco air quality testing (n=108). Data were collected between June and August 2016. Knowledge and opinions of the smoke-free law among hospitality venue staff and owners. The level of compliance with the smoke-free law in hospitality venues through: (1) systematic objective observations (eg, active smoking, the presence of designated smoking areas, 'no smoking' signage) and (2) air quality by measuring the levels of tobacco particulate matter (PM 2.5 ) in both indoor and outdoor venues. Active smoking was observed in 18% of venues, 31% had visible 'no smoking' signage and 47% had visible cigarette remains. Among interviewed respondents, 57% agreed that they had not been adequately informed about the smoke-free law; however, 90% were supportive of the ban. Nearly all respondents (97%) agreed that the law will protect workers' health, but 32% believed that the law would cause financial losses at their establishment. Indoor PM 2.5 levels were hazardous (267.6 µg/m 3 ) in venues that allowed smoking and moderate (29.6 µg/m 3 ) in smoke-free establishments. In the early phase of Uganda's smoke-free law, the level of compliance in hospitality venues settings in Kampala was suboptimal. Civil society and the media have strong potential to inform and educate the hospitality industry and smokers of the benefits and requirements of the smoke-free law. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.